Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Seismic Survey in Cook Inlet, Alaska, 58473-58487 [2011-24241]
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[FR Doc. 2011–24210 Filed 9–20–11; 8:45 am]
BILLING CODE 3510–22–P
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric
Administration
RIN 0648–XA691
Takes of Marine Mammals Incidental to
Specified Activities; Taking Marine
Mammals Incidental to Seismic Survey
in Cook Inlet, Alaska
National Marine Fisheries
Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA),
Commerce.
ACTION: Notice; proposed incidental
harassment authorization; request for
comments.
AGENCY:
NMFS received an
application from Apache Alaska
Corporation (Apache) for an Incidental
Harassment Authorization (IHA) to take
marine mammals, by harassment,
incidental to a proposed 3D seismic
survey in Cook Inlet, Alaska, between
November 2011 and November 2012.
Pursuant to the Marine Mammal
Protection Act (MMPA), NMFS requests
comments on its proposal to issue an
IHA to Apache to take, by Level B
harassment only, five species of marine
mammals during the specified activity.
DATES: Comments and information must
be received no later than October 21,
2011.
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SUMMARY:
Comments on the
application should be addressed to
Michael Payne, Chief, Permits,
Conservation and Education Division,
Office of Protected Resources, National
Marine Fisheries Service, 1315 EastWest Highway, Silver Spring, MD
20910. The mailbox address for
ADDRESSES:
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providing e-mail comments is
ITA.Hopper@noaa.gov. NMFS is not
responsible for e-mail comments sent to
addresses other than the one provided
here. Comments sent via e-mail,
including all attachments, must not
exceed a 10-megabyte file size.
Instructions: All comments received
are a part of the public record and will
generally be posted to https://
www.nmfs.noaa.gov/pr/permits/
incidental.htm without change. All
Personal Identifying Information (for
example, name, address, etc.)
voluntarily submitted by the commenter
may be publicly accessible. Do not
submit Confidential Business
Information or otherwise sensitive or
protected information.
A copy of the application used in this
document may be obtained by writing to
the address specified above, telephoning
the contact listed below (see FOR
FURTHER INFORMATION CONTACT), or
visiting the Internet at: https://
www.nmfs.noaa.gov/pr/permits/
incidental.htm. Documents cited in this
notice may also be viewed, by
appointment, during regular business
hours, at the aforementioned address.
FOR FURTHER INFORMATION CONTACT:
Brian D. Hopper, Office of Protected
Resources, NMFS, (301) 427–8401.
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 small numbers 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 for incidental takings
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.’’
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58473
Section 101(a)(5)(D) of the MMPA
established an expedited process by
which citizens of the U.S. can apply for
an authorization to incidentally take
small numbers of marine mammals by
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 issue or deny
the authorization.
Except with respect to certain
activities not pertinent here, the MMPA
defines ‘‘harassment’’ as:
any act of pursuit, torment, or annoyance
which (i) has the potential to injure a marine
mammal or marine mammal stock in the wild
[‘‘Level A harassment’’]; or (ii) has the
potential to disturb a marine mammal or
marine mammal stock in the wild by causing
disruption of behavioral patterns, including,
but not limited to, migration, breathing,
nursing, breeding, feeding, or sheltering
[‘‘Level B harassment’’].
Summary of Request
NMFS received an application on
June 15, 2011, from Apache for the
taking, by harassment, of marine
mammals incidental to a 3D seismic
survey program in Cook Inlet, Alaska.
After addressing comments from NMFS,
Apache modified its application and
submitted a revised application on July
19, 2011. The July 19, 2011, application
is the one available for public comment
(see ADDRESSES) and considered by
NMFS for this proposed IHA.
The proposed 3D seismic surveys
would employ the use of two source
vessels. Each source vessel will be
equipped with compressors and 2400
in3 air gun arrays, as well as additional
lower-powered and higher frequency
survey equipment for collecting
bathymetric and shallow sub-bottom
data. In addition, one source vessel will
be equipped with a 440 in3 shallow
water air gun array, which it can deploy
at high tide in the intertidal area in less
than 1.8 m of water. The proposed
survey will take place on Apache’s
leases in Cook Inlet, and during the first
year Apache anticipates completing
∼829 km2 of seismic acquisition along
the west coast of Cook Inlet from the
McArthur River up and to the south of
the Beluga river, in water depths of 0–
128 m (0–420 ft).
Apache intends to conduct offshore/
transition (intertidal) zone marine
surveys during November and December
2011 and March 2012. Nearshore areas
adjacent to uplands and offshore areas
will be acquired in open water periods
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between April and September 2012.
Impacts to marine mammals may occur
from noise produced from active
acoustic sources (primarily air guns)
used in the surveys.
Description of the Specified Activity
In 2010, Apache acquired over
300,000 acres of oil and gas leases in
Cook Inlet with the primary objective to
explore for and develop oil fields. In the
spring of 2011, Apache conducted a
seismic test program to evaluate the
feasibility of using new nodal (i.e., no
cables) technology seismic recording
equipment for operations in the Cook
Inlet environment and to test various
seismic acquisition parameters to
finalize the design for a 3D seismic
program in Cook Inlet. The test program
took place in late March 2011 and
results indicated that the nodal
technology was feasible in the Cook
Inlet environment. Apache proposes to
conduct a phased 3D seismic survey
program throughout Cook Inlet over the
course of the next three to five years.
The first area proposed to be surveyed—
and the subject of this proposed IHA—
is located along the western coast of
upper Cook Inlet.
The proposed operations will be
performed from multiple vessels.
Apache will employ the use of two
source vessels. Each source vessel will
be equipped with compressors and 2400
in3 air gun arrays. In addition, one
source vessel will be equipped with a
440 in3 shallow water air gun array,
which it can deploy at high tide in the
intertidal area in less than 1.8 m of
water. Three shallow draft vessels will
support cable/nodal deployment and
retrieval operations, and one mitigation/
chase vessel will be used, which will
source levels of the survey equipment
are provided below.
also provide berthing for the Protected
Species Observers (PSOs). Finally, two
smaller jet boats will be used for
personnel transport and node support in
the extremely shallow water of the
intertidal area. For additional
information, such as vessel
specifications, see Apache’s application.
The actual survey duration to acquire
∼829 km2 will take approximately 160
days to complete over the course of 8–
9 months. Apache anticipates
conducting survey operations 24 hours
per day. During each 24 hour period,
seismic operations will be active;
however, in-water air guns will only be
used for approximately 2.5 hours during
each of the slack tide periods. There are
approximately four slack tide periods in
a 24-hour day, therefore, air gun
operations will be active during
approximately 10–12 hours per day, if
weather conditions allow.
(1) Airguns
The 2400 in3 air gun arrays and the
440 in3 air gun array will be used to
obtain geological data during the survey.
The acoustic source level of the 2400 in3
air gun array was predicted using an air
gun array source model (AASM)
developed by JASCO. The AASM
simulates the expansion and oscillation
of the air bubbles generated by each air
gun within a seismic array, taking into
account pressure interaction effects
between bubbles from different air guns.
It includes effects from surface-reflected
pressure waves, heat transfer from the
bubbles to the surrounding water, and
the movements of bubbles due to their
buoyancy. The model outputs highresolution air gun pressure signatures
for each air gun, which are
superimposed with the appropriate time
delays to yield the overall array source
signature in any direction. The 190, 180,
and 160 dBrms re 1 μPa isopleths were
estimated at three different water depths
(5 m, 25 m, and 45 m) for nearshore
surveys and at 80 m for channel
surveys. The distances to these
thresholds for the nearshore survey
locations are provided in Table 1 and
correspond to the three transects
modeled at each site in the onshore,
nearshore, and parallel to shore
directions. The distances to the
thresholds for the channel survey
locations are provided in Table 2 and
correspond to the broadside and endfire
directions. The areas ensonified to the
160 dB isopleth for the nearshore survey
are provided in Table 3. The area
ensonifed to the 160 dB isopleth for the
channel survey is 389 km2.
3D Seismic Surveys
Seismic surveys are designed to
collect bathymetric and sub-seafloor
data that allow the evaluation of
potential shallow faults, gas zones, and
archeological features at prospective
exploration drilling locations. Data are
typically collected using multiple types
of acoustic equipment. During the
surveys, Apache proposes to use the
following in-water acoustic sources: two
2400 in3 air gun arrays; a single 440 in3
air gun array; a 10 in3 air gun; a Scout
Ultra-Short Baseline (USBL)
Transceiver; and a Lightweight Release
(LR) USBL Transponder. In addition,
Apache plans to detonate 4 kg of Orica
OSX Pentolite explosives onshore to
acquire data. Except for the explosives,
the operating frequencies and estimated
TABLE 1—DISTANCES TO SOUND THRESHOLDS FOR THE NEARSHORE SURVEYS
Water depth at
source location
(m)
Threshold (dB re 1 μPa)
160 ...................................................................................
5
25
45
5
25
45
5
25
45
180 ...................................................................................
190 ...................................................................................
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Distance in the
onshore direction
(km)
Distance in the
offshore direction
(km)
0.85
4.70
5.57
0.46
1.06
0.70
0.28
0.35
0.10
3.91
6.41
4.91
0.60
1.07
0.83
0.33
0.36
0.10
Distance in the
parallel to shore
direction
(km
1.48
6.34
6.10
0.54
1.42
0.89
0.33
0.44
0.51
TABLE 2—DISTANCE TO SOUND THRESHOLDS FOR THE CHANNEL SURVEYS
Water depth at
source location
(m)
Threshold (dB re 1 μPa)
160 .......................................................................................................................
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Distance in the
broadside direction
(km)
80
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Distance in the
endfire direction
(km)
4.89
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TABLE 2—DISTANCE TO SOUND THRESHOLDS FOR THE CHANNEL SURVEYS—Continued
Water depth at
source location
(m)
Threshold (dB re 1 μPa)
180 .......................................................................................................................
190 .......................................................................................................................
Distance in the
broadside direction
(km)
80
80
0.91
0.15
Distance in the
endfire direction
(km)
0.98
0.18
TABLE 3—AREAS ENSONIFIED TO 160 dB FOR NEARSHORE SURVEYS
Depth range
(m)
Nearshore survey depth classification
Shallow ........................................................................................................................................................
Mid-Depth ....................................................................................................................................................
Deep ............................................................................................................................................................
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(2) Pingers
These instruments will be operated
during survey operations to determine
the exact position of the nodes after they
have been placed on the seafloor. One
device, the Scout Ultra-Short Baseline
Transceiver, operates at frequencies
between 33 and 55 kHz with a source
level of 188 dB re 1 μPa at 1 m. The
other device, an LR Ultra-Short Baseline
Transponder, operates at a frequency of
35–50 kHz at a source level of 185 dB
re 1 μPa at 1 m. With respect to these
two sources, Apache provided and
NMFS will rely on the distances to the
Level B harassment thresholds
estimated for the ‘‘louder’’ of the two;
therefore, assuming a simple spreading
loss of 20 log R (where R is radius), with
a source level of 188 dB the distance to
the 190, 180, and 160 dB isopleths
would be 1, 3, and 25 m, respectively.
Another technique for locating the
nodes in deeper water is called Ocean
Bottom Receiver Location, which uses a
small volume air gun (10 in3) firing
parallel to the node line.
(3) Detonations of Explosives
The onshore areas will be surveyed
using explosives as the sound source.
Seismic surveys on land use ‘‘shot
holes’’ that are drilled every 50 m along
source lines and are oriented
perpendicular to the receiver lines and
parallel to the coast. At each source
location, Apache will drill to the
prescribed hole depth of approximately
10 m and load it with 4 kg of explosives.
The hole is then capped with a ‘‘smart
cap’’ that makes it impossible to
detonate the explosive without the
proper detonator. During the 2D test
program conducted in March 2011,
Apache deployed acoustic recorders to
measure underwater sound produced by
land-based explosives; however, the
resulting measurements were
inconclusive and Apache has proposed
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a sound source verification study to
characterize the underwater received
sound levels and determine if marine
mammal monitoring will be required for
future onshore operations.
Apache successfully measured the
sounds produced by the air guns and
pingers during the 2D test program
conducted in March 2011 and found
levels to be consistent with the modeled
mitigation threshold levels (180 dB for
cetaceans, 190 dB for pinnipeds);
therefore, except for the measurements
of in-water sound produced by
detonations of explosives on shore, a
sound source verification study will not
be included in the proposed 3D seismic
survey.
Description of Marine Mammals in the
Area of the Specified Activity
The marine mammal species under
NMFS’s jurisdiction that could occur
near operations in Cook Inlet include
three cetacean species: beluga whale
(Delphinapterus leucas), killer whale
(Orcinus orca), and harbor porpoise
(Phocoena phocoena), and two
pinniped species: harbor seal (Phoca
vitulina richardsi) and Steller sea lions
(Eumetopias jubatus). The marine
mammal species that is likely to be
encountered most widely (in space and
time) throughout the period of the
planned surveys is the harbor seal.
The Cook Inlet beluga whale and
western population of Steller sea lion
are listed as ‘‘endangered’’ under the
Endangered Species Act (ESA) and as
depleted under the MMPA. The site of
the proposed survey is within
designated critical habitat for Cook Inlet
beluga whales.
Apache’s application contains
information on the status, distribution,
seasonal distribution, and abundance of
each of the species under NMFS
jurisdiction mentioned in this
document. Please refer to the
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5–21
21–38
38–54
Area ensonifed to
160 dB
(km2)
346
458
455
application for that information (see
Additional information can
also be found in the NMFS Stock
Assessment Reports (SAR). The Alaska
2010 SAR is available at: https://
www.nmfs.noaa.gov/pr/pdfs/sars/
ak2010.pdf.
ADDRESSES).
Potential Effects of the Specified
Activity on Marine Mammals
Operating active acoustic sources,
such as air gun arrays, has the potential
for adverse effects on marine mammals.
Potential Effects of Air Gun Sounds on
Marine Mammals
The effects of sounds from air gun
pulses might include one or more of the
following: tolerance, masking of natural
sounds, behavioral disturbance, and
temporary or permanent hearing
impairment or non-auditory effects
(Richardson et al. 1995). As outlined in
previous NMFS documents, the effects
of noise on marine mammals are highly
variable, and can be categorized as
follows (based on Richardson et al.
1995):
(1) Tolerance
Numerous studies have shown that
pulsed sounds from air guns are often
readily detectable in the water at
distances of many kilometers.
Numerous studies have also shown that
marine mammals at distances more than
a few kilometers from operating survey
vessels often show no apparent
response. That is often true even in
cases when the pulsed sounds must be
readily audible to the animals based on
measured received levels and the
hearing sensitivity of that mammal
group. Although various toothed
whales, and (less frequently) pinnipeds
have been shown to react behaviorally
to air gun pulses under some
conditions, at other times, mammals of
both types have shown no overt
reactions. In general, pinnipeds and
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small odontocetes seem to be more
tolerant of exposure to air gun pulses
than baleen whales.
(2) Behavioral Disturbance
Marine mammals may behaviorally
react to sound when exposed to
anthropogenic noise. These behavioral
reactions are often shown as: changing
durations of surfacing and dives,
number of blows per surfacing, or
moving direction and/or speed;
reduced/increased vocal activities;
changing/cessation of certain behavioral
activities (such as socializing or
feeding); visible startle response or
aggressive behavior (such as tail/fluke
slapping or jaw clapping); avoidance of
areas where noise sources are located;
and/or flight responses (e.g., pinnipeds
flushing into water from haulouts or
rookeries).
The biological significance of many of
these behavioral disturbances is difficult
to predict, especially if the detected
disturbances appear minor. However,
the consequences of behavioral
modification have the potential to be
biologically significant if the change
affects growth, survival, and
reproduction. Examples of significant
behavioral modifications include:
• Drastic change in diving/surfacing
patterns (such as those thought to be
causing beaked whale stranding due to
exposure to military mid-frequency
tactical sonar);
• Habitat abandonment due to loss of
desirable acoustic environment; and
• Cease feeding or social interaction.
For example, at the Guerreo Negro
Lagoon in Baja California, Mexico,
which is one of the important breeding
grounds for Pacific gray whales,
shipping and dredging associated with a
salt works may have induced gray
whales to abandon the area through
most of the 1960s (Bryant et al. 1984).
After these activities stopped, the
lagoon was reoccupied, first by single
whales and later by cow-calf pairs.
The onset of behavioral disturbance
from anthropogenic noise depends on
both external factors (characteristics of
noise sources and their paths) and the
receiving animals (hearing, motivation,
experience, demography) and is also
difficult to predict (Southall et al. 2007).
Currently NMFS uses a received level
of 160 dB re 1 μPa for impulse noises
(such as air gun pulses) as the onset
threshold for marine mammal
behavioral harassment.
(3) Masking
Chronic exposure to excessive, though
not high-intensity, noise could cause
masking at particular frequencies for
marine mammals that utilize sound for
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vital biological functions. Masking can
interfere with detection of acoustic
signals such as communication calls,
echolocation sounds, and
environmental sounds important to
marine mammals. Since marine
mammals depend on acoustic cues for
vital biological functions, such as
orientation, communication, finding
prey, and avoiding predators, marine
mammals that experience severe
acoustic masking (e.g., of a highintensity level over a long period of time
throughout a biologically important
behavior) could experience biologically
significant effects that could potentially
adversely impact survival or
reproductive success.
Masking occurs when noise and
signals (that the animal utilizes) overlap
at both spectral and temporal scales. For
the air gun noise generated from the
proposed seismic surveys, noise will
consist of low frequency (under 500 Hz)
pulses with extremely short durations
(less than one second). Lower frequency
man-made noises are more likely to
affect detection of communication calls
and other potentially important natural
sounds such as surf and prey noise.
There is little concern regarding
masking near the noise source due to
the brief duration of these pulses and
relatively longer silence between air gun
shots (approximately 12 seconds).
However, at long distances (over tens of
kilometers away), due to multipath
propagation and reverberation, the
durations of air gun pulses can be
‘‘stretched’’ to seconds with long decays
(Madsen et al. 2006), although the
intensity of the noise is greatly reduced.
This could affect communication
signals used by low frequency
mysticetes when they occur near the
noise band and thus reduce the
communication space of animals (e.g.,
Clark et al. 2009) and cause increased
stress levels (e.g., Foote et al. 2004; Holt
et al. 2009); however, no baleen whales
are expected to occur within the action
area. Marine mammals are thought to be
able to compensate for masking by
adjusting their acoustic behavior by
shifting call frequencies, and/or
increasing call volume and vocalization
rates. For example, blue whales are
found to increase call rates when
exposed to seismic survey noise in the
St. Lawrence Estuary (Di Iorio and Clark
2010). The North Atlantic right whales
(Eubalaena glacialis) exposed to high
shipping noise increase call frequency
(Parks et al. 2007), while some
humpback whales respond to lowfrequency active sonar playbacks by
increasing song length (Miller el al.
2000).
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(4) Hearing Impairment
Marine mammals exposed to high
intensity sound repeatedly or for
prolonged periods can experience
hearing threshold shift (TS), which is
the loss of hearing sensitivity at certain
frequency ranges (Kastak et al. 1999;
Schlundt et al. 2000; Finneran et al.
2002; 2005). TS can be permanent
(PTS), in which case the loss of hearing
sensitivity is unrecoverable, or
temporary (TTS), in which case the
animal’s hearing threshold will recover
over time (Southall et al. 2007). Just like
masking, marine mammals that suffer
from PTS or TTS will have reduced
fitness in survival and reproduction,
either permanently or temporarily.
Repeated noise exposure that leads to
TTS could cause PTS. For transient
sounds, the sound level necessary to
cause TTS is inversely related to the
duration of the sound.
Experiments on a bottlenose dolphin
(Tursiops truncatus) and beluga whale
showed that exposure to a single water
gun impulse at a received level of 207
kPa (or 30 psi) peak-to-peak (p–p),
which is equivalent to 228 dB re 1 μPa
(p–p), resulted in a 7 and 6 dB TTS in
the beluga whale at 0.4 and 30 kHz,
respectively. Thresholds returned to
within 2 dB of the pre-exposure level
within 4 minutes of the exposure
(Finneran et al. 2002). No TTS was
observed in the bottlenose dolphin.
Although the source level of pile driving
from one hammer strike is expected to
be much lower than the single water
gun impulse cited here, animals being
exposed for a prolonged period to
repeated hammer strikes could receive
more noise exposure in terms of SEL
than from the single water gun impulse
(estimated at 188 dB re 1 μPa2-s) in the
aforementioned experiment (Finneran et
al. 2002).
In pinnipeds, TTS thresholds
associated with exposure to brief pulses
(single or multiple) of underwater sound
have not been measured. Initial
evidence from prolonged exposures
suggested that some pinnipeds may
incur TTS at somewhat lower received
levels than do small odontocetes
exposed for similar durations (Kastak et
al. 1999, 2005; Ketten et al. 2001).
However, more recent indications are
that TTS onset in the most sensitive
pinniped species studied (harbor seal,
which is closely related to the ringed
seal) may occur at a similar SEL as in
odontocetes (Kastak et al., 2004).
NMFS (1995, 2000) concluded that
cetaceans and pinnipeds should not be
exposed to pulsed underwater noise at
received levels exceeding 180 and 190
dB re 1 μPa rms, respectively. The
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established 180- and 190-dB re 1 μPa
rms criteria are not considered to be the
levels above which TTS might occur.
Rather, they are the received levels
above which, in the view of a panel of
bioacoustics specialists convened by
NMFS before TTS measurements for
marine mammals started to become
available, one could not be certain that
there would be no injurious effects,
auditory or otherwise, to marine
mammals. As summarized above, data
that are now available imply that TTS
is unlikely to occur unless bow-riding
odontocetes are exposed to air gun
pulses much stronger than 180 dB re 1
μPa rms (Southall et al. 2007).
No cases of TTS are expected as a
result of Apache’s proposed activities
given the strong likelihood that marine
mammals would avoid the approaching
air guns (or vessel) before being exposed
to levels high enough for there to be any
possibility of TTS, and the mitigation
measures proposed to be implemented
during the survey described later in this
document.
There is no empirical evidence that
exposure to pulses of air gun sound can
cause PTS in any marine mammal, even
with large arrays of air guns (see
Southall et al., 2007). However, given
the possibility that mammals close to an
air gun array might incur TTS, there has
been further speculation about the
possibility that some individuals
occurring very close to air guns might
incur PTS. Single or occasional
occurrences of mild TTS are not
indicative of permanent auditory
damage in terrestrial mammals.
Relationships between TTS and PTS
thresholds have not been studied in
marine mammals, but are assumed to be
similar to those in humans and other
terrestrial mammals. That is, PTS might
occur at a received sound level
magnitudes higher than the level of
onset TTS, or by repeated exposure to
the levels that cause TTS. Therefore, by
means of preventing the onset of TTS,
it is highly unlikely that marine
mammals could receive sounds strong
enough (and over a sufficient duration)
to cause permanent hearing impairment
during the proposed marine surveys in
Cook Inlet.
(5) Non-auditory Physical Effects
Non-auditory physical effects might
occur in marine mammals exposed to
strong underwater pulsed sound.
Possible types of non-auditory
physiological effects or injuries that
theoretically might occur in mammals
close to a strong sound source include
stress, neurological effects, bubble
formation, and other types of organ or
tissue damage. Some marine mammal
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species (i.e., beaked whales) may be
especially susceptible to injury and/or
stranding when exposed to strong
pulsed sounds. However, there is no
definitive evidence that any of these
effects occur even for marine mammals
in close proximity to large arrays of air
guns, and beaked whales do not occur
in the proposed project area. In
addition, marine mammals that show
behavioral avoidance of seismic vessels,
including most baleen whales, some
odontocetes (including belugas), and
some pinnipeds, are especially unlikely
to incur non-auditory impairment or
other physical effects. The distances to
the 180 and 190 dB thresholds for the
air gun array proposed to be used by
Apache are provided above in Tables 1
and 2.
Therefore, it is unlikely that such
effects would occur during Apache’s
proposed surveys given the brief
duration of exposure and the planned
monitoring and mitigation measures
described later in this document.
(6) Stranding and Mortality
Marine mammals close to underwater
detonations of high explosive can be
killed or severely injured, and the
auditory organs are especially
susceptible to injury (Ketten et al. 1993;
Ketten 1995). Air gun pulses are less
energetic and their peak amplitudes
have slower rise times. To date, there is
no evidence that serious injury, death,
or stranding by marine mammals can
occur from exposure to air gun pulses,
even in the case of large air gun arrays.
However, in numerous past IHA
notices for seismic surveys, commenters
have referenced two stranding events
allegedly associated with seismic
activities, one off Baja California and a
second off Brazil. NMFS has addressed
this concern several times, and, without
new information, does not believe that
this issue warrants further discussion.
For information relevant to strandings of
marine mammals, readers are
encouraged to review NMFS’ response
to comments on this matter found in 69
FR 74905 (December 14, 2004), 71 FR
43112 (July 31, 2006), 71 FR 50027
(August 24, 2006), and 71 FR 49418
(August 23, 2006). In addition, a May–
June 2008, stranding of 100–200 melonheaded whales (Peponocephala electra)
off Madagascar that appears to be
associated with seismic surveys is
currently under investigation (IWC
2009).
It should be noted that strandings
related to sound exposure have not been
recorded for marine mammal species in
Cook Inlet. NMFS notes that beluga
whale strandings in Cook Inlet are not
uncommon; however, these events often
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58477
coincide with extreme tidal fluctuations
(‘‘spring tides’’) or killer whale sightings
(Shelden et al., 2003). No strandings or
marine mammals in distress were
observed during the 2D test survey
conducted by Apache in March 2011
and none were reported by Cook Inlet
inhabitants. As a result, NMFS does not
expect any marine mammals will incur
serious injury or mortality in Cook Inlet
or strand as a result of the proposed
seismic survey.
Potential Effects From Other Sound
Sources on Marine Mammals
Active acoustic sources other than the
air gun arrays have been proposed for
Apache’s seismic survey in Cook Inlet.
The specifications for this equipment
(source levels and frequency ranges) are
provided above. In general, the potential
effects of this equipment on marine
mammals are similar to those from the
air gun, except the magnitude of the
impacts is expected to be much less due
to the lower intensity and higher
frequencies. Estimated source levels
from these devices are discussed above.
Vessel Sounds
In addition to the noise generated
from seismic air guns and active sonar
systems, various types of vessels will be
used in the operations, including source
vessels and the vessel used for placing
and retrieving the nodal recording
system. Sounds from boats and vessels
have been reported extensively (Greene
and Moore 1995; Blackwell and Greene
2002; 2005; 2006). Measurements of
underwater vessel sound have been
performed in upper Cook Inlet. For
example, Blackwell and Greene (2002)
conducted a survey that measured inwater noise from various sources in
Cook Inlet, including a tug boat docking
a barge. The highest SPL recorded for
the working tug under load was 149 dB
re 1 μPa, at a distance of about 90 m,
with an extrapolated SPL at 0.9 m of
178.9 dB re 1 μPa. Compared to air gun
pulses, underwater sound from vessels
is generally at relatively low
frequencies.
The primary sources of sounds from
all vessel classes are propeller
cavitation, propeller singing, and
propulsion or other machinery.
Propeller cavitation is usually the
dominant noise source for vessels (Ross
1976). Propeller cavitation and singing
are produced outside the hull, whereas
propulsion or other machinery noise
originates inside the hull. There are
additional sounds produced by vessel
activity, such as pumps, generators,
flow noise from water passing over the
hull, and bubbles breaking in the wake.
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Land-Based Explosives
The onshore component of the
seismic survey involves the
underground detonation of explosive
devices to acquire seismic data on land.
Because underwater sound levels
associated with the land-based
explosives are currently unknown,
Apache proposes to conduct a sound
source verification (SSV) study to
ensure that marine mammals are not
exposed to underwater sound levels that
exceed the NMFS injury or harassment
thresholds. This study is expected to
take two days to complete and a report
will be submitted to NMFS prior to
making a final determination on
whether to issue or deny the IHA. The
study will include a robust marine
mammal monitoring plan to ensure that
marine mammals are not harassed or
injured. For example, Apache proposes
to conduct visual monitoring using
vessel-based and aerial platforms. In
addition, the SSV will only take place
during daylight hours with good
visibility. Following the completion of
the study, a SSV report will be
submitted to NMFS. The report will
describe the operations that were
conducted and the marine mammals
that were observed. The report will
provide full documentation of the
methods, results, and interpretations
pertaining to all monitoring and will
contain information on the need to
implement marine mammal monitoring
during land-based operations.
Anticipated Effects on Marine Mammal
Habitat
The primary potential impacts to
marine mammal habitat and other
marine species are associated with
elevated sound levels produced by
airguns and other active acoustic
sources. However, other potential
impacts to the surrounding habitat from
physical disturbance are also possible
and are discussed below.
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Potential Impacts on Prey Species
With regard to fish as a prey source
for cetaceans and pinnipeds, fish are
known to hear and react to sounds and
to use sound to communicate (Tavolga
et al. 1981) and possibly avoid predators
(Wilson and Dill 2002). Experiments
have shown that fish can sense both the
strength and direction of sound
(Hawkins 1981). Primary factors
determining whether a fish can sense a
sound signal, and potentially react to it,
are the frequency of the signal and the
strength of the signal in relation to the
natural background noise level.
The level of sound at which a fish
will react or alter its behavior is usually
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well above the detection level. Fish
have been found to react to sounds
when the sound level increased to about
20 dB above the detection level of 120
dB (Ona 1988); however, the response
threshold can depend on the time of
year and the fish’s physiological
condition (Engas et al. 1993). In general,
fish react more strongly to pulses of
sound rather than a continuous signal
(Blaxter et al. 1981), and a quicker alarm
response is elicited when the sound
signal intensity rises rapidly compared
to sound rising more slowly to the same
level.
Investigations of fish behavior in
relation to vessel noise (Olsen et al.
1983; Ona 1988; Ona and Godo 1990)
have shown that fish react when the
sound from the engines and propeller
exceeds a certain level. Avoidance
reactions have been observed in fish
such as cod and herring when vessels
approached close enough that received
sound levels are 110 dB to 130 dB
(Nakken 1992; Olsen 1979; Ona and
Godo 1990; Ona and Toresen 1988).
However, other researchers have found
that fish such as polar cod, herring, and
capeline are often attracted to vessels
(apparently by the noise) and swim
toward the vessel (Rostad et al. 2006).
Typical sound source levels of vessel
noise in the audible range for fish are
150 dB to 170 dB (Richardson et al.
1995).
Potential Impacts to the Benthic
Environment
Apache’s seismic survey requires the
deployment of a submersible recording
system in the inter-tidal and marine
zones. An autonomous ‘‘nodal’’ (i.e., no
cables) system will be placed on the
seafloor by specific vessels in lines
parallel to each other with a node line
spacing of 402 m. Each nodal ‘‘patch’’
will have six to eight node lines parallel
to each other. The lines generally run
perpendicular to the shoreline. An
entire patch will be placed on the
seafloor prior to air gun activity. As the
patches are surveyed, the node lines
will be moved either side to side or
inline to the next location. Placement
and retrieval of the nodes may cause
temporary and localized increases in
turbidity on the seafloor. The substrate
of Cook Inlet consists of glacial silt,
clay, cobbles, pebbles, and sand
(Sharma and Burrell, 1970). Sediments
like sand and cobble dissipate quickly
when suspended, but finer materials
like clay and silt can create thicker
plumes that may harm fish; however,
the turbidity created by placing and
removing nodes on the seafloor will
settle to background levels within
minutes after the cessation of activity.
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Based on the preceding discussion,
the proposed activity is not expected to
have any habitat-related effects that
could cause significant or long-term
consequences for individual marine
mammals or their populations.
Proposed Mitigation
In order to issue an incidental take
authorization under section 101(a)(5)(D)
of the MMPA, NMFS must set forth the
permissible methods of taking pursuant
to such activity, and other means of
effecting the least practicable adverse
impact on such species or stock and its
habitat, paying particular attention to
rookeries, mating grounds, and areas of
similar significance, and on the
availability of such species or stock for
taking for certain subsistence uses.
For the proposed seismic survey in
Cook Inlet, Apache worked with NMFS
and proposed the following mitigation
measures to minimize the potential
impacts to marine mammals in the
project vicinity as a result of the survey
activities.
Mitigation Measures Proposed in
Apache’s IHA Application
For the proposed mitigation measures,
Apache listed the following protocols to
be implemented during its seismic
survey in Cook Inlet.
(1) Operation of Mitigation Air Gun at
Night
Apache proposes to conduct both
daytime and nighttime operations.
Nighttime operations will only be
initiated if a mitigation air gun
(typically the 10 in3) has been
continuously operational from the time
that PSO monitoring has ceased for the
day. Seismic activity will not ramp up
from an extended shut-down during
nighttime operations because dedicated
PSOs will not be on duty and any
unseen animals may be exposed to
injurious levels of sound from the full
array. At night, the vessel captain and
crew will maintain lookout for marine
mammals and will order the air gun(s)
to be shut down if marine mammals are
observed in or about to enter the safety
radii. If a shut-down occurs during
nighttime operations, seismic survey
activity will be suspended until the
following day and will only be resumed
if the full safety zone is visible.
(2) Safety and Disturbance Zones
Under current NMFS guidelines,
‘‘safety radii’’ for marine mammal
exposure to impulse sources are
customarily defined as the distances
within which received sound levels are
≥180 dBrms re 1 μPa for cetaceans and
≥190 dBrms re 1 μPa for pinnipeds. These
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safety criteria are based on an
assumption that SPL received at levels
lower than these will not injure these
animals or impair their hearing abilities,
but that SPL received at higher levels
might have some such effects.
Disturbance or behavioral effects to
marine mammals from underwater
sound may occur after exposure to
sound at distances greater than the
safety radii (Richardson et al. 1995).
The proposed surveys will use an air
gun sources composed of two 2400 in3
air guns, a single 440 in3 air gun, and
a single 10 in3 air gun. Safety and
disturbance radii for the sound levels
produced by the planned airgun
configurations have been estimated
(Tables 1 and 2) and will be used for
mitigation purposes during the seismic
survey activities.
In addition to the marine mammal
monitoring radii described above,
pursuant to Alaska Department of Fish
and Game restrictions, there will be a
1.6 km setback of sound source points
from the mouths of any anadromous
streams.
Apache also plans to use dedicated
vessels to deploy and retrieve the nodal
recording system. Sounds produced by
the vessels are not expected to exceed
180 dB (rms). Therefore, mitigation
related to acoustic impacts from these
activities is not expected to be
necessary.
An acoustics contractor will perform
direct measurements of the received
levels of underwater sound versus
distance and direction from the
detonation of explosives onshore using
calibrated hydrophones. The acoustic
data will be analyzed as quickly as
reasonably practicable in the field and
used to determine whether the
detonation of explosives onshore
exposes marine mammals to underwater
sound levels that may result in Level B
harassment. The field report will be
made available to NMFS prior to the
final determination on whether to issue
or deny the IHA. If necessary, mitigation
measures similar to those proposed for
the other sound sources (i.e.,
establishment of 160, 180, and 190 dB
isopleths with dedicated monitoring
and detonation delay procedures) will
be implemented for this aspect of the
seismic survey.
(3) Speed and Course Alterations
If a marine mammal is detected
outside the applicable safety radius and,
based on its position and the relative
motion, is likely to enter the safety
radius, changes of the vessel’s speed
and/or direct course will be considered
if this does not compromise operational
safety. For marine seismic surveys using
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large arrays, course alterations are not
typically possible. However, for the
smaller air gun arrays planned during
the proposed site surveys, such changes
may be possible. After any such speed
and/or course alteration is begun, the
marine mammal activities and
movements relative to the survey vessel
will be closely monitored to ensure that
the marine mammal does not approach
within the safety radius. If the mammal
appears likely to enter the safety radius,
further mitigative actions will be taken,
including a power down or shut down
of the airgun(s).
(4) Power-Downs
A power-down for mitigation
purposes is the immediate reduction in
the number of operating airguns such
that the radii of the 190 dB rms and 180
dB rms zones are decreased to the extent
that an observed marine mammal(s) are
not in the applicable safety zone of the
full array. During a power-down, one air
gun, typically the 10 in3, continues
firing. Operation of the 10 in3 air gun
decreases the safety radii to 10 m, 33 m,
and 330 m for the 190 dB, 180 dB, and
160 dB, respectively. The continued
operation of one airgun is intended to
(a) alert marine mammals to the
presence of the survey vessel in the
area, and (b) retain the option of
initiating a ramp up to full operations
under poor visibility conditions.
The array will be immediately
powered down whenever a marine
mammal is sighted approaching close to
or within the applicable safety zone of
the full array, but is outside the
applicable safety zone of the single
mitigation airgun. Likewise, if a
mammal is already within the safety
zone when first detected, the airguns
will be powered down immediately. If
a marine mammal is sighted within or
about to enter the applicable safety zone
of the single mitigation airgun, it too
will be shut down (see following
section).
Following a power-down, operation of
the full airgun array will not resume
until the marine mammal has cleared
the safety zone. The animal will be
considered to have cleared the safety
zone if it
• Is visually observed to have left the
safety zone of the full array, or
• Has not been seen within the zone
for 15 min in the case of pinnipeds or
small odontocetes, or
• Has not been seen within the zone
for 30 min in the case of large
odontocetes.
(5) Shut-Downs
The operating air gun(s) will be shut
down completely if a marine mammal
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approaches or enters the safety radius
and a power-down is not practical or
adequate to reduce exposure to less than
190 or 180 dB rms, as appropriate. In
most cases, this means the mitigation
airgun will be shut down completely if
a marine mammal approaches or enters
the estimated safety radius around the
single 10 in3 air gun while it is
operating during a power down. Air gun
activity will not resume until the marine
mammal has cleared the safety radius.
The animal will be considered to have
cleared the safety radius as described
above under power down procedures.
(6) Ramp Ups
A ramp up of an air gun array
provides a gradual increase in sound
levels, and involves a step-wise increase
in the number and total volume of air
guns firing until the full volume is
achieved. The purpose of a ramp-up (or
‘‘soft start’’) is to ‘‘warn’’ cetaceans and
pinnipeds in the vicinity of the air guns
and to provide the time for them to
leave the area and thus avoid any
potential injury or impairment of their
hearing abilities.
During the proposed seismic survey,
the seismic operator will ramp up the
airgun cluster slowly. Full ramp-ups
(i.e., from a cold start after a shut-down,
when no airguns have been firing) will
begin by firing a single airgun in the
array. The minimum duration of a shutdown period, i.e., without air guns
firing, which must be followed by a
ramp-up is typically the amount of time
it would take the source vessel to cover
the 180-dB safety radius. Given the size
of the planned air gun arrays, that
period is estimated to be about 1–2
minutes based on the modeling results
described above and a survey speed of
2–4 kts.
A full ramp up, after a shut down,
will not begin until there has been a
minimum of 30 minutes of observation
of the safety zone by PSOs to assure that
no marine mammals are present. The
entire safety zone must be visible during
the 30-minute lead-in to a full ramp up.
If the entire safety zone is not visible,
then ramp up from a cold start cannot
begin. If a marine mammal(s) is sighted
within the safety zone during the 30minute watch prior to ramp up, ramp up
will be delayed until the marine
mammal(s) is sighted outside of the
safety zone or the animal(s) is not
sighted for at least 15–30 minutes: 15
minutes for small odontocetes and
pinnipeds, or 30 minutes for large
odontocetes.
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Additional Mitigation Measures
Proposed by NMFS
Besides Apache’s proposed mitigation
measures discussed above, NMFS
proposes the following additional
protective measures to address some
uncertainties regarding the impacts of
seismic surveys on beluga whale cowcalf pairs and aggregations of whales.
Specifically, NMFS proposes that a 160dB vessel monitoring zone will be
established and monitored in Cook Inlet
during all seismic surveys. Whenever an
aggregation of beluga whales, killer
whales, or harbor porpoises (five or
more whales of any age/sex class that
appear to be engaged in a nonmigratory, significant biological
behavior (e.g., feeding, socializing)) are
observed approaching the 160-dB safety
zone around the survey operations, the
survey activity will not commence or
will shut down, until they are no longer
present within the 160-dB safety zone of
seismic surveying operations.
Furthermore, NMFS proposes the
following measures be included in the
IHA, if issued, in order to ensure the
least practicable impact on the affected
species or stocks:
(1) All vessels should reduce speed
when within 300 yards (274 m) of
whales, and those vessels capable of
steering around such groups should do
so. Vessels may not be operated in such
a way as to separate members of a group
of whales from other members of the
group;
(2) Avoid multiple changes in
direction and speed when within 300
yards (274 m) of whales; and
(3) When weather conditions require,
such as when visibility drops, support
vessels must adjust speed (increase or
decrease) and direction accordingly to
avoid the likelihood of injury to whales.
Mitigation Conclusions
NMFS has carefully evaluated the
applicant’s proposed mitigation
measures and considered a range of
other measures in the context of
ensuring that NMFS prescribes the
means of effecting the least practicable
impact on the affected marine mammal
species and stocks and their habitat. Our
evaluation of potential measures
included consideration of the following
factors in relation to one another:
• The manner in which, and the
degree to which, the successful
implementation of the measure is
expected to minimize adverse impacts
to marine mammals;
• The proven or likely efficacy of the
specific measure to minimize adverse
impacts as planned; and
• The practicability of the measure
for applicant implementation.
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Based on our evaluation of the
applicant’s proposed measures, as well
as other measures considered by NMFS,
NMFS has preliminarily determined
that the proposed mitigation measures
provide the means of effecting the least
practicable impact on marine mammal
species or stocks and their habitat,
paying particular attention to rookeries,
mating grounds, and areas of similar
significance.
Proposed Monitoring and Reporting
In order to issue an ITA for an
activity, section 101(a)(5)(D) of the
MMPA states that NMFS must set forth
‘‘requirements pertaining to the
monitoring and reporting of such
taking’’. The MMPA implementing
regulations at 50 CFR 216.104(a)(13)
indicate that requests for ITAs must
include the suggested means of
accomplishing the necessary monitoring
and reporting that will result in
increased knowledge of the species and
of the level of taking or impacts on
populations of marine mammals that are
expected to be present in the proposed
action area.
Monitoring Measures Proposed in
Apache’s IHA Application
The monitoring plan proposed by
Apache can be found in section 13 of
the IHA application. The plan may be
modified or supplemented based on
comments or new information received
from the public during the public
comment period. A summary of the
primary components of the plan
follows.
(1) Visual Vessel-Based Monitoring
Vessel-based monitoring for marine
mammals will be done by experienced
PSOs throughout the period of marine
survey activities. PSOs will monitor the
occurrence and behavior of marine
mammals near the survey vessel during
all daylight periods during operation
and during most daylight periods when
airgun operations are not occurring.
PSO duties will include watching for
and identifying marine mammals,
recording their numbers, distances, and
reactions to the survey operations, and
documenting ‘‘take by harassment’’ as
defined by NMFS.
A sufficient number of PSOs will be
required onboard the survey vessel to
meet the following criteria: (1) 100
percent monitoring coverage during all
periods of survey operations in daylight;
(2) maximum of 4 consecutive hours on
watch per PSO; and (3) maximum of 12
hours of watch time per day per PSO.
PSO teams will consist of experienced
field biologists. An experienced field
crew leader will supervise the PSO team
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onboard the survey vessel. Apache
currently plans to have PSOs aboard the
three vessels: the two source vessels (M/
V Peregrine Falcon and M/V Arctic
Wolf) and one support vessel (M/V
Dreamcatcher). Two PSOs will be on
the source vessels and two PSOs will be
on the support vessel to observe the
safety, power down, and shut down
areas. When marine mammals are about
to enter or are sighted within designated
safety zones, air gun or pinger
operations will be powered down (when
applicable) or shut down immediately.
The vessel-based observers will watch
for marine mammals during all periods
when sound sources are in operation
and for a minimum of 30 minutes prior
to the start of air gun or pinger
operations after an extended shut down.
Crew leaders and most other
biologists serving as observers will be
individuals with experience as
observers during seismic surveys in
Alaska or other areas in recent years.
The observer(s) will watch for marine
mammals from the best available
vantage point on the source and support
vessels, typically the flying bridge. The
observer(s) will scan systematically with
the unaided eye and 7 × 50 reticle
binoculars. Laser range finders will be
available to assist with estimating
distance. Personnel on the bridge will
assist the observer(s) in watching for
marine mammals.
All observations will be recorded in a
standardized format. Data will be
entered into a custom database using a
notebook computer. The accuracy of the
data will be verified by computerized
validity data checks as the data are
entered and by subsequent manual
checks of the database. These
procedures will allow for initial
summaries of the data to be prepared
during and shortly after the completion
of the field program, and will facilitate
transfer of the data to statistical,
geographical, or other programs for
future processing and achieving. When
a mammal sighting is made, the
following information about the sighting
will be recorded:
(A) Species, group size, age/size/sex
categories (if determinable), behavior
when first sighted and after initial
sighting, heading (if consistent), bearing
and distance from the PSO, apparent
reaction to activities (e.g., none,
avoidance, approach, paralleling, etc.),
closest point of approach, and
behavioral pace;
(B) Time, location, speed, activity of
the vessel, sea state, ice cover, visibility,
and sun glare; and
(C) The positions of other vessel(s) in
the vicinity of the PSO location.
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The ship’s position, speed of support
vessels, and water temperature, water
depth, sea state, ice cover, visibility, and
sun glare will also be recorded at the
start and end of each observation watch,
every 30 minutes during a watch, and
whenever there is a change in any of
those variables.
(2) Visual Shore-Based Monitoring
In addition to the vessel-based PSOs,
Apache proposes to utilize a shorebased station to visually monitor for
marine mammals. The shore-based
station will follow all safety procedures,
including bear safety. The location of
the shore-based station will need to be
sufficiently high to observe marine
mammals; the PSOs would be equipped
with pedestal mounted ‘‘big eye’’ (20 ×
110) binoculars. The shore-based PSOs
would scan the area prior to, during,
and after the air gun operations, and
would be in contact with the vesselbased PSOs via radio to communicate
sightings of marine mammals
approaching or within the project area.
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(3) Aerial-Based Monitoring
When practicable, Apache proposes to
utilize the crew helicopter to conduct
aerial surveys near river mouths prior to
the commencement of air gun
operations in order to identify locations
where beluga whales congregate. The
helicopter will not be used every day,
but will be used when survey operations
occur near a river mouth. The types of
helicopters currently planned for use by
Apache include a Bell 407, Bell UH1B,
and ASB3. Weather and scheduling
permitting, aerial surveys will fly at an
altitude of 305 m (1,000 ft). In the event
of a marine mammal sighting, aircraft
will attempt to maintain a radial
distance of 457 m (1,500 ft) from the
marine mammal(s). Aircraft will avoid
approaching marine mammals from
head-on, flying over or passing the
shadow of the aircraft over the marine
mammal(s). By following these
operational requirements, sound levels
underwater are not expected to meet or
exceed NMFS harassment thresholds
(Richardson et al., 1995; Blackwell et
al., 2002).
(4) Acoustic Monitoring
To further enhance detection of
cetaceans, Apache proposes to deploy
passive acoustic monitoring (PAM)
devices during the seismic survey.
According to Apache’s IHA application,
the actual PAM system has not been
identified; however, Apache anticipates
utilizing the same system that was
deployed during the 2D test program in
March 2011 in Cook Inlet. Apache
expects to deploy two PAM devices that
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will send real-time acoustic data via
digital UHF radio-broadcast systems to
the PAM operators aboard the M/V
Dreamcatcher. The PAM operators will
use specialized real-time detection
software and audio playback to detect
marine mammal sounds. If the PAM
operators detect marine mammals,
Apache will initiate a temporary shutdown of the air gun arrays to avoid
takes. Following a shut-down, the air
guns may be restarted in accordance
with the ramp-up procedure described
earlier.
Reporting Measures
(1) SSV Report on In-Water Noise From
Explosives Onshore
A report on the preliminary results of
the acoustic verification measurements,
including as a minimum the measured
190-, 180-, and 160-dBrms re 1 μPa radii
of the onshore explosive detonations,
will be submitted prior to the
publication of a Federal Register notice
announcing the issuance or denial of the
IHA. If applicable, this report will
specify the distances of the safety zones
that will be adopted and monitored for
the marine survey activities.
(2) Field Reports
During the proposed survey program,
the PSOs will prepare a report each day
or at such other interval as the IHA (if
issued), or Apache may require,
summarizing the recent results of the
monitoring program. The field reports
will summarize the species and
numbers of marine mammals sighted.
These reports will be provided to NMFS
and to the survey operators.
(3) Technical Report
The results of Apache’s 2011
monitoring program, including
estimates of ‘‘take’’ by harassment, will
be presented in the ‘‘90-day’’ and Final
Technical reports. The Technical Report
will include:
(a) Summaries of monitoring effort
(e.g., total hours, total distances, and
marine mammal distribution through
the study period, accounting for sea
state and other factors affecting
visibility and detectability of marine
mammals);
(b) Analyses of the effects of various
factors influencing detectability of
marine mammals (e.g., sea state, number
of observers, and fog/glare);
(c) Species composition, occurrence,
and distribution of marine mammal
sightings, including date, water depth,
numbers, age/size/gender categories (if
determinable), group sizes, and ice
cover;
(d) Analyses of the effects of survey
operations;
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• Sighting rates of marine mammals
during periods with and without
seismic survey activities (and other
variables that could affect detectability),
such as:
• Initial sighting distances versus
survey activity state;
• Closest point of approach versus
survey activity state;
• Observed behaviors and types of
movements versus survey activity state;
• Numbers of sightings/individuals
seen versus survey activity state;
• Distribution around the source
vessels versus survey activity state; and
• Estimates of take by harassment.
(4) Comprehensive Report
Following the survey season, a
comprehensive report describing the
vessel-based, shore-based, aerial-based,
and acoustic monitoring programs will
be prepared. The comprehensive report
will describe the methods, results,
conclusions and limitations of each of
the individual data sets in detail. The
report will also integrate (to the extent
possible) the studies into a broad based
assessment of industry activities, and
other activities that occur in Cook Inlet,
and their impacts on marine mammals.
The report will help to establish longterm data sets that can assist with the
evaluation of changes in the Cook Inlet
ecosystem. The report will attempt to
provide a regional synthesis of available
data on industry activity in this part of
Alaska that may influence marine
mammal density, distribution and
behavior.
(5) Notification of Injured or Dead
Marine Mammals
In the unanticipated event that the
specified activity clearly causes the take
of a marine mammal in a manner
prohibited by the IHA (if issued), such
as an injury (Level A harassment),
serious injury or mortality (e.g., shipstrike, gear interaction, and/or
entanglement), Apache will
immediately cease the specified
activities and immediately report the
incident to the Chief of the Permits,
Conservation, and Education Division,
Office of Protected Resources, NMFS,
and the Alaska Regional Stranding
Coordinators. The report must include
the following information:
• Time, date, and location (latitude/
longitude) of the incident;
• Name and type of vessel involved;
• Vessel’s speed during and leading
up to the incident;
• Description of the incident;
• Status of all sound source use in the
24 hours preceding the incident;
• Water depth;
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• Environmental conditions (e.g.,
wind speed and direction, Beaufort sea
state, cloud cover, and visibility);
• Description of all marine mammal
observations in the 24 hours preceding
the incident;
• Species identification or
description of the animal(s) involved;
• Fate of the animal(s); and
• Photographs or video footage of the
animal(s) (if equipment is available).
Activities will not resume until NMFS
is able to review the circumstances of
the prohibited take. NMFS will work
with Apache to determine what is
necessary to minimize the likelihood of
further prohibited take and ensure
MMPA compliance. Apache may not
resume their activities until notified by
NMFS via letter, e-mail, or telephone.
In the event that Apache discovers an
injured or dead marine mammal, and
the lead PSO determines that the cause
of the injury or death is unknown and
the death is relatively recent (i.e., in less
than a moderate state of decomposition
as described in the next paragraph),
Apache will immediately report the
incident to the Chief of the Permits,
Conservation, and Education Division,
Office of Protected Resources, NMFS,
and the NMFS Alaska Stranding Hotline
and/or by e-mail to the Alaska Regional
Stranding Coordinators. The report must
include the same information identified
in the paragraph above. Activities may
continue while NMFS reviews the
circumstances of the incident. NMFS
will work with Apache to determine
whether modifications in the activities
are appropriate.
In the event that Apache discovers an
injured or dead marine mammal, and
the lead PSO determines that the injury
or death is not associated with or related
to the activities authorized in the IHA
(e.g., previously wounded animal,
carcass with moderate to advanced
decomposition, or scavenger damage),
Apache will report the incident to the
Chief of the Permits, Conservation, and
Education Division, Office of Protected
Resources, NMFS, and the NMFS
Alaska Stranding Hotline and/or by email to the Alaska Regional Stranding
Coordinators, within 24 hours of the
discovery. Apache will provide
photographs or video footage (if
available) or other documentation of the
stranded animal sighting to NMFS and
the Marine Mammal Stranding Network.
Estimated Take by Incidental
Harassment
Except with respect to certain
activities not pertinent here, the MMPA
defines ‘‘harassment’’ as: any act of
pursuit, torment, or annoyance which (i)
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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]. Only take by Level B
behavioral harassment is anticipated as
a result of the proposed marine survey
program. Anticipated impacts to marine
mammals are associated with noise
propagation from the airgun(s) used in
the seismic survey; however, Level B
harassment may also result from the
detonation of explosives onshore if
supported by the proposed SSV study.
The full suite of potential impacts to
marine mammals was described in
detail in the ‘‘Potential Effects of the
Specified Activity on Marine Mammals’’
section found earlier in this document.
The potential effects of sound from the
proposed seismic survey might include
one or more of the following: tolerance;
masking of natural sounds; behavioral
disturbance; non-auditory physical
effects; and, at least in theory,
temporary or permanent hearing
impairment (Richardson et al. 1995). As
discussed earlier in this document, the
most common impact will likely be
from behavioral disturbance, including
avoidance of the ensonified area or
changes in speed, direction, and/or
diving profile of the animal. For reasons
discussed previously in this document,
hearing impairment (TTS and PTS) are
highly unlikely to occur based on the
proposed mitigation and monitoring
measures that would preclude marine
mammals being exposed to noise levels
high enough to cause hearing
impairment.
For impulse sounds, such as those
produced by airgun(s) used in the
seismic survey, NMFS uses the 160
dBrms re 1 μPa isopleth to indicate the
onset of Level B harassment. Apache
provided calculations for the 160-dB
isopleths and then used those isopleths
to estimate takes by harassment. NMFS
used the calculations to make the
necessary MMPA preliminary findings.
Apache provided a full description of
the methodology used to estimate takes
by harassment in its IHA application
(see ADDRESSES), which is also provided
in the following sections.
Apache requests authorization to take
five marine mammal species by Level B
harassment. These five marine mammal
species are: Cook Inlet beluga whale
(Delphinapterus leucas); killer whale
(Orcinus orca); harbor porpoise
(Phocoena phocoena); harbor seal
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(Phoca vitulina richardsi), and Steller
sea lion (Eumetopias jubatus).
Basis for Estimating ‘‘Take by
Harassment’’
As stated previously, it is current
NMFS policy to estimate take by Level
B harassment for impulse sounds at a
received level of 160 dBrms re 1 μPa.
However, not all animals react to
sounds at this low level, and many will
not show strong reactions (and in some
cases any reaction) until sounds are
much stronger. Southall et al. (2007)
provide a severity scale for ranking
observed behavioral responses of both
free-ranging marine mammals and
laboratory subjects to various types of
anthropogenic sound (see Table 4 in
Southall et al. (2007)). Tables 7, 9, and
11 in Southall et al. (2007) outline the
numbers of low-frequency cetaceans,
mid-frequency cetaceans, and pinnipeds
in water, respectively, reported as
having behavioral responses to multipulses in 10-dB received level
increments. These tables illustrate that
for the studies summarized the more
severe reactions did not occur until
sounds were much higher than 160
dBrms re 1 μPa.
As described earlier in the document,
air gun arrays will be used to obtain
geological data during the surveys. For
use in estimating potential harassment
takes in this application, as well as for
mitigation radii to be implemented by
PSOs, ranges to the 160 dBrms re 1 μPa
isopleths were estimated at three
different water depths (5 m, 25 m, and
45 m) for nearshore surveys and at 80
m for channel surveys. The distances to
this threshold for the nearshore survey
locations are provided in Table 1 and
correspond to the three transects
modeled at each site in the onshore,
nearshore, and parallel to shore
directions. The distances to the
thresholds for the channel survey
locations are provided in Table 2 and
correspond to the broadside and endfire
directions. The areas ensonified to the
160 dB isopleth for the nearshore survey
are provided in Table 3. The area
ensonifed to the 160 dB isopleth for the
channel survey is 389 km2.
The following subsections describe
the estimated densities of marine
mammals that may occur in the areas
where activities are planned, and areas
of water that may be ensonified by
pulsed sounds to ≥160 dB.
Marine mammal densities near the
planned activities in Cook Inlet were
estimated from the annual aerial surveys
conducted by NMFS between 2000 and
2010 for Cook Inlet beluga whales (Rugh
et al. 2000, 2001, 2002, 2003, 2004,
2005, 2006, 2007; Shelden et al. 2008,
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2009, 2010). These surveys are flown in
June to collect abundance data for
beluga whales, but sightings of other
marine mammals are also reported.
Although these data are only collected
in one month each year, these surveys
provide the best available relatively
long-term data set for sighting
information in the proposed action area,
but do not account for seasonal
variations in distribution or habitat use
of each species. Therefore, the use of
these data to estimate density is
considered to be extremely conservative
with respect to the probability of
observing these animals in the action
area. The maximum and average
densities over the course of the total
survey years (2000–2010) are provided
in Table 4. As discussed below, beluga
whales are observed in higher
concentrations near river mouths,
particularly the Susitna River, due to
feeding. Therefore, to account for the
higher concentrations near river
mouths, the highest number of beluga
whales observed for each year was used
to provide a density for river mouths. To
58483
account for the lower concentrations
away from river mouths, the average
number of beluga whales observed for
each year was used to provide a density
away from river mouths. A maximum
and average density are provided to
account for the inherent level of
uncertainty in using aerial surveys
conducted for a few days once a year in
order to estimate density for the entire
year. These densities will be used to
estimate the number of Level B takes
incidental to the proposed activity.
TABLE 4—SUMMARY OF MARINE MAMMAL DENSITIES
Density (number/km 2)
Species
Maximum
Beluga whale (average number observed) .....................................................................................................
Beluga whale (maximum number observed—rivers) ......................................................................................
Harbor seal (total number observed) ..............................................................................................................
Harbor porpoise (total number observed) .......................................................................................................
Killer whale (total number observed) ...............................................................................................................
Steller sea lion (total number observed) .........................................................................................................
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Fifteen species of marine mammals
are known to occur in Cook Inlet, but
only five of these (Cook Inlet beluga
whales, killer whales, harbor porpoises,
harbor seals, and Steller sea lions) are
likely to be encountered during the
proposed survey activities in the upper
inlet. Two of the five species (Cook Inlet
beluga whales and western population
of Steller sea lions) are listed as
endangered under the ESA.
(1) Cetaceans
Beluga Whales—Cook Inlet beluga
whales reside in Cook Inlet year-round
although their distribution and density
changes seasonally. Factors that are
likely to influence beluga whale
distribution within the inlet include
prey availability, predation pressure,
sea-ice cover, and other environmental
factors, reproduction, sex and age class,
and human activities (Rugh et al., 2000;
NMFS 2008). Seasonal movement and
density patterns as well as site fidelity
appear to be closely linked to prey
availability, coinciding with seasonal
salmon and eulachon concentrations
(Moore et al., 2000). For example,
during spring and summer, beluga
whales are generally concentrated near
the warmer waters of river mouths
where prey availability is high and
predator occurrence in low (Huntington
2000; Moore et al., 2000). Beluga whales
use several areas of the upper Cook Inlet
for repeated summer and fall feeding.
The primary hotspots for beluga feeding
include the Big and Little Susitna rivers,
Eagle Bay to Eklutna River, Ivan Slough,
Theodore River, Lewis River, and
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Chickaloon River and Bay (NMFS 2008).
Availability of prey species appears to
be the most influential environmental
variable affecting Cook Inlet beluga
whale distribution and relative
abundance (Moore et al. 2000). The
patterns and timing of eulachon and
salmon runs have a strong influence on
beluga whale feeding behavior and their
seasonal movements (Nemeth et al.,
2007; NMFS 2008). The presence of
prey species may account for the
seasonal changes in beluga group size
and composition (Moore et al., 2000).
Aerial and vessel-based monitoring
conducted by Apache during the March
2011 2D test program in Cook Inlet
reported 33 beluga sightings. One of the
sightings was of a large group (∼25
individuals on March 27, 2011) of
feeding/milling belugas near the mouth
of the Drift River. Also on March 27,
2011, PSOs onboard the M/V
Dreamcatcher reported a group of seven
beluga whales approximately 0.5 nm
from the vessel. Land-based PSOs were
able to observe this group of beluga
whales for approximately 2.5 hrs. A
single beluga whale was observed near
the mouth of the Drift River by the
aerial-based monitors on March 28,
2011, prior to the seismic ramp-up
period. If belugas are present during the
late summer/early fall, they are more
likely to occur in shallow areas near
river mouths in upper Cook Inlet. As
discussed earlier, expected densities
were calculated from the annual aerial
surveys conducted by NMFS between
2000 and 2010 (Rugh et al. 2000, 2001,
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0.00103
0.00770
0.00776
0.00037
0.00011
0.00035
Average
0.00026
0.00154
0.00290
0.00004
0.00001
0.00007
2002, 2003, 2004, 2005, 2006, 2007;
Shelden et al. 2008, 2009, 2010). Those
densities are presented above in Table 4.
Killer Whales—In general, killer
whales are rare in upper Cook Inlet,
where transient killer whales are known
to feed on beluga whales and resident
killer whales are known to feed on
anadromous fish (Shelden et al., 2003).
The availability of these prey species
largely determines the likeliest times for
killer whales to be in the area. Between
1993 and 2004, 23 sightings of killer
whales were reported in the lower Cook
Inlet during aerial surveys by Rugh et al.
(2005). Surveys conducted over a span
of 20 years by Shelden et al. (2003)
reported 11 sightings in upper Cook
Inlet between Turnagain Arm, Susitna
Flats, and Knik Arm. No killer whales
were spotted during recent surveys by
Funk et al. (2005), Ireland et al. (2005),
Brueggeman et al. (2007a, 2007b, 2008),
or Prevel Ramos et al. (2006, 2008).
Eleven killer whale strandings have
been reported in Turnagain Arm, six in
May 1991 and five in August 1993.
Therefore, very few killer whales, if any,
are expected to approach or be in the
vicinity of the action area.
Harbor Porpoise—The most recent
estimated density for harbor porpoises
in Cook Inlet is 7.2 per 1,000 km2
(Dahlheim et al., 2000) indicating that
only a small number use Cook Inlet.
Harbor porpoise have been reported in
lower Cook Inlet from Cape Douglas to
the West Foreland, Kachemak Bay, and
offshore (Rugh et al., 2005). Small
numbers of harbor porpoises have been
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consistently reported in upper Cook
Inlet between April and October, except
for a recent survey that recorded higher
than usual numbers. Prevel Ramos et al.
(2008) reported 17 harbor porpoises
from spring to fall 2006, while other
studies reported 14 in the spring of 2007
(Brueggeman et al. 2007) and 12 in the
fall (Brueggeman et al. 2008). During the
spring and fall of 2007, 129 harbor
porpoises were reported between
Granite Point and the Susitna River;
however, the reason for the increase in
numbers of harbor porpoise in the upper
Cook Inlet remains unclear and the
disparity with the result of past
sightings suggests that it may be an
anomaly. The spike in reported
sightings occurred in July, which was
followed by sightings of 79 harbor
porpoises in August, 78 in September,
and 59 in October, 2007. It is important
to note that the number of porpoises
counted more than once was unknown,
which suggests that the actual numbers
are likely smaller than those reported. In
addition, recent passive acoustic
research in Cook Inlet by the Alaska
Department of Fish and Game and the
National Marine Mammal Laboratory
have indicated that harbor porpoises
occur in the area more frequently than
previously thought, particularly in the
West Foreland area in the spring (NMFS
2011); however overall numbers are still
unknown at this time.
(2) Pinnipeds
Two species of pinnipeds may be
encountered in Cook Inlet: Harbor seal
and Steller sea lion.
Harbor Seals—Harbor seals inhabit
the coastal and estuarine waters of Cook
Inlet. In general, harbor seals are more
abundant in lower Cook Inlet than in
upper Cook Inlet, but they do occur in
the upper inlet throughout most of the
year (Rugh et al. 2005). Harbor seals are
non-migratory; their movements are
associated with tides, weather, season,
food availability, and reproduction. The
major haulout sites for harbor seals are
located in lower Cook Inlet and their
presence in the upper inlet coincides
with seasonal runs of prey species. For
example, harbor seals are commonly
observed along the Susitna River and
other tributaries along upper Cook Inlet
during the eulachon and salmon
migrations (NMFS 2003). During aerial
surveys of upper Cook Inlet in 2001,
2002, and 2003, harbor seals were
observed 24 to 96 km south-southwest
of Anchorage at the Chickaloon, Little
Susitna, Susitna, Ivan, McArthur, and
Beluga Rivers (Rugh et al., 2005). During
the 2D test program in March 2011, two
harbor seals were observed by vesselbased PSOs. On March 25, 2011, one
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harbor seal was observed approximately
400 m from the M/V Miss Diane. At the
time of the observation, the vessel was
operating the positioning pinger and
PSOs instructed the operator to
implement a shut-down. The pinger was
shut down for 30 minutes while PSO
monitored the area and re-started the
device when the animal was not sighted
again during the 30 minute site clearing
protocol. No unusual behaviors were
reported during the time the animal was
observed. The second harbor seal was
observed on March 26, 2011, by vesselbased PSO onboard the M/V
Dreamcatcher approximately 4260 m
from the source vessel, which was
operating the 10 in3 air gun at the time.
The animal was well outside of the 160
dB zone (330 m for the 10 in3 air gun)
and no unusual behaviors were
observed. The closest haulout site to the
action area is located on Kalgin Island,
which is approximately 22 km away
from the McArthur River.
Steller Sea Lion—Two separate stocks
of Steller sea lions are recognized
within U.S. waters: an eastern U.S.
stock, which includes animals east of
Cape Suckling, Alaska; and a western
U.S. stock, which includes animals west
of Cape Suckling (NMFS 2008).
Individuals in Cook Inlet are considered
part of the western U.S. stock, which is
listed as endangered under the ESA.
Steller sea lions primarily occur in
lower, rather than upper Cook Inlet and
are rarely sighted north of Nikiski on the
Kenai Peninsula. Haul-outs and
rookeries are located near Cook Inlet at
Gore Point, Elizabeth Island, Perl Island,
and Chugach Island (NMFS 2008). No
Steller seal lion haul-outs or rookeries
are located in the vicinity of the
proposed seismic survey. Furthermore,
no sightings of Steller sea lions were
reported by Apache during the 2D test
program in March 2011. Although
Apache has requested takes of Steller
sea lions, it is unlikely that any Steller
sea lions would occur in the action are
during seismic survey operations.
Potential Number of Takes by
Harassment
This subsection provides estimates of
the number of individuals potentially
exposed to sound levels ≥160 dBrms re
1 μPa during seismic survey operations.
The estimates were calculated by
multiplying the expected densities by
the anticipated area ensonified by levels
≥160 dBrms re 1 μPa by the number of
expected days that will be subject to
seismic survey activities in the action
area. According to section 2 in Apache’s
IHA application, a survey crew will
collect seismic data 10–12 hours per day
over approximately 160 days over the
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course of 8 to 9 months. Apache
assumes that over the course of these
160 days, 100 days would be working in
the offshore region and 60 days would
be working in the shallow, intermediate,
and deep nearshore region. Of those 60
days in the nearshore region, 20 days
would be spent working in each of the
three depths. Because operations would
occur over 12 hours per day, the total
number of days for each region was
divided by two (or half a day) for
purposes of calculating takes. It is
important to note that environmental
conditions (such as ice, wind, and fog)
will play a significant role in the actual
number of operating days; therefore,
these estimates are conservative in order
to provide a basis for the probability of
encountering these marine mammal
species in the action area.
The number of estimated takes by
Level B harassment was calculated
using the following assumptions:
• The number of nearshore and
shallow water survey days is 10 (20
days/12 hours) and daily acoustic
footprint is 356 km2.
• The number of nearshore and
intermediate water depth survey days is
10 (20 days/12 hours) and daily acoustic
footprint is 468 km2.
• The number of nearshore and deep
water depth survey days is 10 (20 days/
12 hours) and daily acoustic footprint is
455 km2.
• The number of offshore survey days
is 50 (100 days/12 hours) and daily
acoustic footprint is 389 km2.
Table 5 shows the estimated
maximum and average takes by species
for the first year of seismic surveys in
Cook Inlet with the methods and
assumptions outlined above. As noted
earlier, the use of the NMML aerial
survey data has inherent weaknesses
that need to be discussed further. For
example, the estimated number of takes
by Level B harassment of harbor seals is
higher than what is anticipated because
there are no haul-out sites within the
action area. Seals in some numbers are
expected to be observed in the Susitna
River delta, but not in the large numbers
that are observed in lower Cook Inlet.
These density estimates are skewed by
the numbers observed in large haul outs
during aerial surveys. Seals in the water
usually travel in small groups or as
single individuals; therefore, although
Table 5 indicates an average of 102 and
maximum of 207 seals exposed to
sounds likely to result in Level B
harassment, it is highly unlikely that
those number of seals will actually be
taken during the proposed seismic
survey.
Similarly, and for many of the same
reasons, the number of actual takes by
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Level B harassment of Steller sea lions
is expected to be much lower than the
average of four and maximum of 11.
During the NMFS aerial surveys, no
Steller sea lions were observed in upper
Cook Inlet. Less than five Steller sea
lions have been observed by the Port of
Anchorage monitoring program, and
those observed have been juvenile
animals (likely male). Apache
anticipates that there will be less than
five Steller sea lions in the proposed
action area during the one-year effective
period of the IHA, if issued.
The average and maximum take
estimates for harbor porpoise and killer
whales shown in Table 5 appear to be
reasonable based on the NMFS aerial
surveys, although the actual number of
animals is expected to be low.
The average and maximum estimated
number of takes by Level B harassment
for Cook Inlet beluga whales away from
river mouths is two and five,
respectively. Given that beluga are
usually transiting from one feeding area
to another in lower concentrations,
these estimates appear to be reasonable
in assessing the probability for
potentially observing beluga whales in
the action area. However, it is important
to note that a combination of visual and
acoustic monitoring will be used
extensively throughout this project,
particularly for sighting beluga whales
approaching the area, so the actual
number of takes is expected to be lower
than these estimates.
The average and maximum estimated
number of takes by Level B harassment
for Cook Inlet beluga whales near river
mouths is 16 and 41 animals,
respectively. The total number of days
surveying will actually occur near river
mouths is much lower than the 160 days
used to estimate takes in the different
water depths; therefore, this take
estimate is likely to be extremely
conservative. As a result, due to the
actual number of days and hours
Apache is likely to be operating air guns
near river mouths and taking into
account the monitoring and mitigation
measures applicable when operating
seismic survey equipment near rivers,
Apache expects the actual number of
takes by Level B harassment estimated
for Cook Inlet beluga whales to be much
lower than the numbers provided in
Table 5.
TABLE 5—ESTIMATED TAKES PER SPECIES FOR YEAR 1
Shallow
Mid-depth
Deep
Offshore
Total
Species
max
Beluga whales—away from river mouths ........
Beluga whales—near river mouths ..................
Harbor seals .....................................................
Harbor porpoises ..............................................
Killer whales .....................................................
Steller sea lions ................................................
Estimated Take Conclusions
Cetaceans—Effects on cetaceans are
generally expected to be restricted to
avoidance of an area around the seismic
survey and short-term changes in
behavior, falling within the MMPA
definition of ‘‘Level B harassment’’.
Using the 160 dB criterion, the
requested take numbers of individual
cetaceans exposed to sounds ≥160 dBrms
re 1 μPa represent varying proportions
of the populations of each species in
Cook Inlet (Table 6). For species listed
as ‘‘Endangered’’ under the ESA, the
0.5
4.5
22.9
1.3
0.4
1.2
avg
max
0.3
1.8
11.3
0.2
0.1
0.4
0.7
5.8
29.5
1.7
0.5
1.6
avg
max
0.3
2.3
14.5
0.3
0.1
0.5
0.7
5.8
29.3
1.7
0.5
1.6
number of takes requested includes 30
Cook Inlet beluga whales. This number
is approximately 8.5 percent of the
population of approximately 355
animals (Allen and Angliss 2010). For
other cetaceans that might occur in the
vicinity of the seismic survey in Cook
Inlet, the requested takes also represent
a very small proportion of their
respective populations. The requested
takes of 10 killer whales and 20 harbor
porpoises represent 0.89 percent and
0.06 percent of their respective
populations in the proposed action area.
avg
0.3
2.3
14.4
0.3
0.1
0.5
max
2.8
24.8
125.3
7.2
2.2
6.8
avg
1.5
9.9
61.7
1.2
0.3
2.2
max
4.7
41
207
11.9
3.6
11.3
avg
2.4
16.3
101.9
2.0
0.5
3.7
Pinnipeds—Two pinniped species
may be encountered in the proposed
action area, but the harbor seal is likely
to be the more abundant species in this
area. The number of takes requested for
individuals exposed to sounds at
received levels ≥160 dBrms re 1 μPa
during the proposed seismic survey are
as follows: harbor seals (50) and Steller
sea lions (20). These numbers represent
0.17 percent and 0.12 percent of their
respective populations in the proposed
action area.
TABLE 6—REQUESTED NUMBER OF TAKES
Number of
requested takes
Species
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Beluga whales .................................................................................................................
Harbor seals ....................................................................................................................
Harbor porpoises .............................................................................................................
Killer whales .....................................................................................................................
Steller sea lions ...............................................................................................................
Negligible Impact and Small Numbers
Analysis and Preliminary Determination
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
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15:20 Sep 20, 2011
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to, adversely affect the species or stock
through effects on annual rates of
recruitment or survival.’’ In making a
negligible impact determination, NMFS
considers a variety of factors, including
but not limited to: (1) The number of
anticipated mortalities; (2) the number
and nature of anticipated injuries; (3)
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Population
abundance
30
50
20
10
20
355
29,175
31,406
1,123
41,197
Percent of
population
8.45
0.17
0.06
0.89
0.12
the number, nature, intensity, and
duration of Level B harassment; and (4)
the context in which the takes occur.
No injuries or mortalities are
anticipated to occur as a result of
Apache’s proposed seismic survey in
Cook Inlet, and none are proposed to be
authorized. Additionally, animals in the
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area are not expected to incur hearing
impairment (i.e., TTS or PTS) or nonauditory physiological effects. Takes
will be limited to Level B behavioral
harassment. Although it is possible that
some individuals of marine mammals
may be exposed to sounds from seismic
survey activities more than once, the
expanse of these multi-exposures are
expected to be less extensive since both
the animals and the survey vessels will
be moving constantly in and out of the
survey areas.
Odontocete reactions to seismic
energy pulses are usually assumed to be
limited to shorter distances from the
airgun(s) than are those of mysticetes,
probably in part because odontocete
low-frequency hearing is assumed to be
less sensitive than that of mysticetes.
However, at least when in the Canadian
Beaufort Sea in summer, belugas appear
to be fairly responsive to seismic energy,
with few being sighted within 6–12 mi
(10–20 km) of seismic vessels during
aerial surveys (Miller et al. 2005).
Belugas will likely occur in small
numbers in Cook Inlet during the survey
period and few will likely be affected by
the survey activity. In addition, due to
the constant moving of the survey
vessel, the duration of the noise
exposure by cetaceans to seismic
impulse would be brief. For the same
reason, it is unlikely that any individual
animal would be exposed to high
received levels multiple times.
Taking into account the mitigation
measures that are planned, effects on
cetaceans are generally expected to be
restricted to avoidance of a limited area
around the survey operation and shortterm changes in behavior, falling within
the MMPA definition of ‘‘Level B
harassment’’.
Furthermore, the estimated numbers
of animals potentially exposed to sound
levels sufficient to cause appreciable
disturbance are very low percentages of
the population sizes in Cook Inlet, as
described above.
The many reported cases of apparent
tolerance by cetaceans of seismic
exploration, vessel traffic, and some
other human activities show that coexistence is possible. Mitigation
measures such as controlled vessel
speed, dedicated marine mammal
observers, non-pursuit, and shut downs
or power downs when marine mammals
are seen within defined ranges will
further reduce short-term reactions and
minimize any effects on hearing
sensitivity. In all cases, the effects are
expected to be short-term, with no
lasting biological consequence.
Some individual pinnipeds may be
exposed to sound from the proposed
marine surveys more than once during
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15:20 Sep 20, 2011
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the time frame of the project. However,
as discussed previously, due to the
constant moving of the survey vessel,
the probability of an individual
pinniped being exposed to sound
multiple times is much lower than if the
source is stationary. Therefore, NMFS
has preliminarily determined that the
exposure of pinnipeds to sounds
produced by the proposed seismic
survey in Cook Inlet is not expected to
result in more than Level B harassment
and is anticipated to have no more than
a negligible impact on the animals.
Of the five marine mammal species
likely to occur in the proposed marine
survey area, only Cook Inlet beluga
whales and Steller sea lions are listed as
endangered under the ESA. These
species are also designated as
‘‘depleted’’ under the MMPA. Despite
these designations, Cook Inlet beluga
whales and the western population of
Steller sea lions have not made
significant progress towards recovery.
The Cook Inlet population of beluga
whales has been decreasing at a rate of
1.5 percent annually for nearly a decade
(Allen and Angliss 2010). With respect
to Steller sea lions, results of aerial
surveys conducted in 2008 (Fritz et al.,
2008) confirmed that the recent (2004–
2008) overall trend in the western
population of adult and juvenile Steller
sea lions in Alaska is stable or possibly
in decline; however, there continues to
be considerable regional variability in
recent trends. Pursuant to the ESA,
critical habitat has been designated for
Cook Inlet beluga whales and Steller sea
lions. The proposed action falls within
critical habitat designated in Cook Inlet
for beluga whales, but is not within
critical habitat designated for Steller sea
lions. None of the other species that
may occur in the project area are listed
as threatened or endangered under the
ESA or designated as depleted under the
MMPA.
Potential impacts to marine mammal
habitat were discussed previously in
this document (see the ‘‘Anticipated
Effects on Habitat’’ section). Although
some disturbance is possible to food
sources of marine mammals, the
impacts are anticipated to be minor
enough as to not affect rates of
recruitment or survival of marine
mammals in the area. Based on the size
of Cook Inlet where feeding by marine
mammals occurs versus the localized
area of the marine survey activities, any
missed feeding opportunities in the
direct project area would be minor
based on the fact that other feeding
areas exist elsewhere.
The requested takes proposed to be
authorized represent 8.5 percent of the
Cook Inlet beluga whale population of
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Sfmt 4703
approximately 355 animals (Allen and
Angliss 2010), 0.89 percent of the
combined Alaska resident stock and
Gulf of Alaska, Aleutian Island and
Bering Sea stock of killer whales (1,123
residents and 314 transients), and 0.06
percent of the Gulf of Alaska stock of
approximately 31,046 harbor porpoises.
The take requests presented for harbor
seals represent 0.17 percent of the Gulf
of Alaska stock of approximately 29,175
animals. Finally, the requested takes
proposed for Steller sea lions represent
0.12 percent of the western stock of
approximately 41,197 animals. These
estimates represent the percentage of
each species or stock that could be taken
by Level B behavioral harassment if
each animal is taken only once. In
addition, the mitigation and monitoring
measures (described previously in this
document) proposed for inclusion in the
IHA (if issued) are expected to reduce
even further any potential disturbance
to marine mammals.
Based on the analysis contained
herein of the likely effects of the
specified activity on marine mammals
and their habitat, and taking into
consideration the implementation of the
mitigation and monitoring measures,
NMFS preliminarily finds that Apache’s
proposed seismic survey in Cook Inlet
may result in the incidental take of
small numbers of marine mammals, by
Level B harassment only, and that the
total taking from the marine surveys
will have a negligible impact on the
affected species or stocks.
Impact on Availability of Affected
Species or Stock for Taking for
Subsistence Uses
Section 101(a)(5)(D) also requires
NMFS to determine that the
authorization will not have an
unmitigable adverse effect on the
availability of marine mammal species
or stocks for subsistence use. NMFS has
defined ‘‘unmitigable adverse impact’’
in 50 CFR 216.103 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 harvest of beluga
whales transcends the nutritional and
economic value attributed to the whale
and is an integral part of the cultural
identity of the region’s Alaska Native
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communities. Inedible parts of the
whale provide Native artisans with
materials for cultural handicrafts, and
the hunting itself perpetuates Native
traditions by transmitting traditional
skills and knowledge to younger
generations (NOAA 2007). However,
due to dramatic declines in the Cook
Inlet beluga whale population, on May
21, 1999, a temporary moratorium on
beluga whale harvest was established
(Pub. L. 106–31, section 3022, 113
Statute (Stat.) 57,100) from 1999 until
October 1, 2000. This moratorium was
extended indefinitely on December 21,
2000 (Pub. L. 106–553, section 1(a)(2),
114 Stat. 2762). NMFS has entered into
a co-management agreement for beluga
whale subsistence harvest. Pursuant to
that agreement, no hunt has been
conducted since 2005 and on October
15, 2008, NMFS published a final rule
establishing long-term limits on the
maximum number of Cook Inlet beluga
whales that may be taken by Alaska
Natives for subsistence and handicraft
purposes (73 FR 60976). These rules
effectively state that no harvest will be
conducted until 2012, at which time the
possibility of a harvest will be reevaluated based on beluga whale
population trends.
With respect to the proposed action,
Apache met with the Cook Inlet Marine
Mammal Council (CIMMC)—a group of
Native Alaskans with traditional
subsistence hunting rights—on March
29, 2011, to discuss the proposed
activities and discuss any subsistence
concerns. In addition, Apache met with
the Tyonek Native Corporation on
November 9, 2010 and the Salamatof
Native Corporation on November 22,
2010. During these meetings, no
concerns were raised regarding potential
conflict with subsistence harvest of
marine mammals. Apache has identified
the following features that are intended
to reduce impacts to subsistence users:
• In-water seismic activities will
follow mitigation procedures to
minimize effects on the behavior of
marine mammals and, therefore,
opportunities for harvest by Alaska
Native communities;
• Regional subsistence
representatives may support recording
marine mammal observations along
with marine mammal biologists during
the monitoring programs and will be
provided with annual reports; and
• The size of the affected area,
mitigation measures, and input from the
CIMMC should result in the proposed
action having no effect on the
availability of marine mammals for
subsistence uses.
NMFS anticipates that any
harassment to marine mammals,
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15:20 Sep 20, 2011
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including Cook Inlet beluga whales,
would be short-term, site specific, and
limited to inconsequential changes in
behavior and mild stress responses.
NMFS does not anticipate that the
authorized taking of affected species or
stocks will result in changes in
reproduction, survival, or longevity
rates, impact population levels, or result
in changes in distribution. Therefore,
NMFS has preliminarily determined
that the proposed regulations will not
have an unmitigable adverse impact on
the availability of marine mammal
stocks for subsistence uses.
Endangered Species Act (ESA)
There are two marine mammal
species listed as endangered under the
ESA with confirmed or possible
occurrence in the proposed project area:
the Cook Inlet beluga whale and Steller
sea lion. NMFS’ Permits, Conservation
and Education Division has initiated
consultation with NMFS’ Protected
Resources Division under section 7 of
the ESA on the issuance of an IHA to
Apache under section 101(a)(5)(D) of the
MMPA for this activity. Consultation
will be concluded prior to a
determination on the issuance of an
IHA.
National Environmental Policy Act
(NEPA)
NMFS is currently preparing an
Environmental Assessment, pursuant to
NEPA, to determine whether or not this
proposed activity may have a significant
effect on the human environment. This
analysis will be completed prior to the
issuance or denial of the IHA.
Proposed Authorization
As a result of these preliminary
determinations, NMFS proposes to
authorize the take of marine mammals
incidental to Apache’s seismic survey in
Cook Inlet, Alaska, provided the
previously mentioned mitigation,
monitoring, and reporting requirements
are incorporated.
Dated: September 15, 2011.
James H. Lecky,
Director, Office of Protected Resources,
National Marine Fisheries Service.
[FR Doc. 2011–24241 Filed 9–20–11; 8:45 am]
BILLING CODE 3510–22–P
DEPARTMENT OF DEFENSE
Department of the Navy
Notice of Availability of GovernmentOwned Invention; Available for
Licensing
AGENCY:
PO 00000
Department of the Navy, DOD.
Frm 00028
Fmt 4703
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ACTION:
58487
Notice.
The following invention is
assigned to the United States
Government as represented by the
Secretary of the Navy and is made
available for licensing by the
Department of the Navy. U.S. Patent
Application Serial Number 13/137521:
Bulk HME Precursor Detection Kit.
ADDRESSES: Requests for copies of the
Patent Application cited should be
directed to the Naval Surface Warfare
Center, Code CAB, 3824 Strauss
Avenue, Indian Head, MD 20640–5152.
FOR FURTHER INFORMATION CONTACT: Dr.
J. Scott Deiter, Head, Technology
Transfer Office, Naval Surface Warfare
Center Indian Head Division, Code CAB,
3824 Strauss Avenue, Indian Head, MD
20640–5152, telephone 301–744–6111.
SUMMARY:
Dated: September 13, 2011.
J. M. Beal,
Lieutenant Commander, Judge Advocate
General’s Corps, U.S. Navy, Federal Register
Liaison Officer.
[FR Doc. 2011–24182 Filed 9–20–11; 8:45 am]
BILLING CODE 3810–FF–P
DEPARTMENT OF DEFENSE
Department of the Navy
Notice of Intent To Grant Partially
Exclusive License; American
Innovations, Inc.
Department of the Navy, DoD.
Notice.
AGENCY:
ACTION:
The Department of the Navy
hereby gives notice of its intent to grant
American Innovations, Inc. a revocable,
nonassignable, partially exclusive
license, with exclusive fields of use in
entry control points, route clearance,
patrolling, site exploitation, cache finds,
area surveillance, joint security stations/
combat outposts, raids, SPECOPS, K–9
support, training, in the United States to
practice the Government-owned
invention, U.S. Patent Application
Serial Number 13/137521, filed August
24, 2011, entitled ‘‘Bulk Homemade
Explosives (HME) Precursor Detection
Kit.’’
DATES: Anyone wishing to object to the
grant of this license must file written
objections along with supporting
evidence, if any, not later than October
6, 2011.
ADDRESSES: Written objections are to be
filed with the Indian Head Division,
Naval Surface Warfare Center, Code
OC4, Bldg. D–31, 3824 Strauss Avenue,
Indian Head, MD 20640–5152.
FOR FURTHER INFORMATION CONTACT: Dr.
J. Scott Deiter, Head, Technology
SUMMARY:
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[Federal Register Volume 76, Number 183 (Wednesday, September 21, 2011)]
[Notices]
[Pages 58473-58487]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-24241]
-----------------------------------------------------------------------
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XA691
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Seismic Survey in Cook Inlet,
Alaska
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; proposed incidental harassment authorization; request
for comments.
-----------------------------------------------------------------------
SUMMARY: NMFS received an application from Apache Alaska Corporation
(Apache) for an Incidental Harassment Authorization (IHA) to take
marine mammals, by harassment, incidental to a proposed 3D seismic
survey in Cook Inlet, Alaska, between November 2011 and November 2012.
Pursuant to the Marine Mammal Protection Act (MMPA), NMFS requests
comments on its proposal to issue an IHA to Apache to take, by Level B
harassment only, five species of marine mammals during the specified
activity.
DATES: Comments and information must be received no later than October
21, 2011.
ADDRESSES: Comments on the application should be addressed to Michael
Payne, Chief, Permits, Conservation and Education Division, Office of
Protected Resources, National Marine Fisheries Service, 1315 East-West
Highway, Silver Spring, MD 20910. The mailbox address for providing e-
mail comments is ITA.Hopper@noaa.gov. NMFS is not responsible for e-
mail comments sent to addresses other than the one provided here.
Comments sent via e-mail, including all attachments, must not exceed a
10-megabyte file size.
Instructions: All comments received are a part of the public record
and will generally be posted to https://www.nmfs.noaa.gov/pr/permits/incidental.htm without change. All Personal Identifying Information
(for example, name, address, etc.) voluntarily submitted by the
commenter may be publicly accessible. Do not submit Confidential
Business Information or otherwise sensitive or protected information.
A copy of the application used in this document may be obtained by
writing to the address specified above, telephoning the contact listed
below (see FOR FURTHER INFORMATION CONTACT), or visiting the Internet
at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm. Documents cited
in this notice may also be viewed, by appointment, during regular
business hours, at the aforementioned address.
FOR FURTHER INFORMATION CONTACT: Brian D. Hopper, Office of Protected
Resources, NMFS, (301) 427-8401.
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 small numbers 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 for incidental takings 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 U.S. can apply for an authorization to
incidentally take small numbers of marine mammals by 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 issue or deny the authorization.
Except with respect to certain activities not pertinent here, the
MMPA defines ``harassment'' as:
any act of pursuit, torment, or annoyance which (i) has the
potential to injure a marine mammal or marine mammal stock in the
wild [``Level A harassment'']; or (ii) has the potential to disturb
a marine mammal or marine mammal stock in the wild by causing
disruption of behavioral patterns, including, but not limited to,
migration, breathing, nursing, breeding, feeding, or sheltering
[``Level B harassment''].
Summary of Request
NMFS received an application on June 15, 2011, from Apache for the
taking, by harassment, of marine mammals incidental to a 3D seismic
survey program in Cook Inlet, Alaska. After addressing comments from
NMFS, Apache modified its application and submitted a revised
application on July 19, 2011. The July 19, 2011, application is the one
available for public comment (see ADDRESSES) and considered by NMFS for
this proposed IHA.
The proposed 3D seismic surveys would employ the use of two source
vessels. Each source vessel will be equipped with compressors and 2400
in\3\ air gun arrays, as well as additional lower-powered and higher
frequency survey equipment for collecting bathymetric and shallow sub-
bottom data. In addition, one source vessel will be equipped with a 440
in\3\ shallow water air gun array, which it can deploy at high tide in
the intertidal area in less than 1.8 m of water. The proposed survey
will take place on Apache's leases in Cook Inlet, and during the first
year Apache anticipates completing ~829 km\2\ of seismic acquisition
along the west coast of Cook Inlet from the McArthur River up and to
the south of the Beluga river, in water depths of 0-128 m (0-420 ft).
Apache intends to conduct offshore/transition (intertidal) zone
marine surveys during November and December 2011 and March 2012.
Nearshore areas adjacent to uplands and offshore areas will be acquired
in open water periods
[[Page 58474]]
between April and September 2012. Impacts to marine mammals may occur
from noise produced from active acoustic sources (primarily air guns)
used in the surveys.
Description of the Specified Activity
In 2010, Apache acquired over 300,000 acres of oil and gas leases
in Cook Inlet with the primary objective to explore for and develop oil
fields. In the spring of 2011, Apache conducted a seismic test program
to evaluate the feasibility of using new nodal (i.e., no cables)
technology seismic recording equipment for operations in the Cook Inlet
environment and to test various seismic acquisition parameters to
finalize the design for a 3D seismic program in Cook Inlet. The test
program took place in late March 2011 and results indicated that the
nodal technology was feasible in the Cook Inlet environment. Apache
proposes to conduct a phased 3D seismic survey program throughout Cook
Inlet over the course of the next three to five years. The first area
proposed to be surveyed--and the subject of this proposed IHA--is
located along the western coast of upper Cook Inlet.
The proposed operations will be performed from multiple vessels.
Apache will employ the use of two source vessels. Each source vessel
will be equipped with compressors and 2400 in\3\ air gun arrays. In
addition, one source vessel will be equipped with a 440 in\3\ shallow
water air gun array, which it can deploy at high tide in the intertidal
area in less than 1.8 m of water. Three shallow draft vessels will
support cable/nodal deployment and retrieval operations, and one
mitigation/chase vessel will be used, which will also provide berthing
for the Protected Species Observers (PSOs). Finally, two smaller jet
boats will be used for personnel transport and node support in the
extremely shallow water of the intertidal area. For additional
information, such as vessel specifications, see Apache's application.
The actual survey duration to acquire ~829 km\2\ will take
approximately 160 days to complete over the course of 8-9 months.
Apache anticipates conducting survey operations 24 hours per day.
During each 24 hour period, seismic operations will be active; however,
in-water air guns will only be used for approximately 2.5 hours during
each of the slack tide periods. There are approximately four slack tide
periods in a 24-hour day, therefore, air gun operations will be active
during approximately 10-12 hours per day, if weather conditions allow.
3D Seismic Surveys
Seismic surveys are designed to collect bathymetric and sub-
seafloor data that allow the evaluation of potential shallow faults,
gas zones, and archeological features at prospective exploration
drilling locations. Data are typically collected using multiple types
of acoustic equipment. During the surveys, Apache proposes to use the
following in-water acoustic sources: two 2400 in\3\ air gun arrays; a
single 440 in\3\ air gun array; a 10 in\3\ air gun; a Scout Ultra-Short
Baseline (USBL) Transceiver; and a Lightweight Release (LR) USBL
Transponder. In addition, Apache plans to detonate 4 kg of Orica OSX
Pentolite explosives onshore to acquire data. Except for the
explosives, the operating frequencies and estimated source levels of
the survey equipment are provided below.
(1) Airguns
The 2400 in\3\ air gun arrays and the 440 in\3\ air gun array will
be used to obtain geological data during the survey. The acoustic
source level of the 2400 in\3\ air gun array was predicted using an air
gun array source model (AASM) developed by JASCO. The AASM simulates
the expansion and oscillation of the air bubbles generated by each air
gun within a seismic array, taking into account pressure interaction
effects between bubbles from different air guns. It includes effects
from surface-reflected pressure waves, heat transfer from the bubbles
to the surrounding water, and the movements of bubbles due to their
buoyancy. The model outputs high-resolution air gun pressure signatures
for each air gun, which are superimposed with the appropriate time
delays to yield the overall array source signature in any direction.
The 190, 180, and 160 dBrms re 1 [mu]Pa isopleths were
estimated at three different water depths (5 m, 25 m, and 45 m) for
nearshore surveys and at 80 m for channel surveys. The distances to
these thresholds for the nearshore survey locations are provided in
Table 1 and correspond to the three transects modeled at each site in
the onshore, nearshore, and parallel to shore directions. The distances
to the thresholds for the channel survey locations are provided in
Table 2 and correspond to the broadside and endfire directions. The
areas ensonified to the 160 dB isopleth for the nearshore survey are
provided in Table 3. The area ensonifed to the 160 dB isopleth for the
channel survey is 389 km\2\.
Table 1--Distances to Sound Thresholds for the Nearshore Surveys
----------------------------------------------------------------------------------------------------------------
Water depth at Distance in the Distance in the Distance in the
Threshold (dB re 1 [micro]Pa) source location onshore direction offshore direction parallel to shore
(m) (km) (km) direction (km
----------------------------------------------------------------------------------------------------------------
160............................. 5 0.85 3.91 1.48
25 4.70 6.41 6.34
45 5.57 4.91 6.10
180............................. 5 0.46 0.60 0.54
25 1.06 1.07 1.42
45 0.70 0.83 0.89
190............................. 5 0.28 0.33 0.33
25 0.35 0.36 0.44
45 0.10 0.10 0.51
----------------------------------------------------------------------------------------------------------------
Table 2--Distance to Sound Thresholds for the Channel Surveys
----------------------------------------------------------------------------------------------------------------
Water depth at Distance in the Distance in the
Threshold (dB re 1 [micro]Pa) source location broadside endfire direction
(m) direction (km) (km)
----------------------------------------------------------------------------------------------------------------
160................................................. 80 4.24 4.89
[[Page 58475]]
180................................................. 80 0.91 0.98
190................................................. 80 0.15 0.18
----------------------------------------------------------------------------------------------------------------
Table 3--Areas Ensonified to 160 dB for Nearshore Surveys
------------------------------------------------------------------------
Nearshore survey depth Area ensonifed to
classification Depth range (m) 160 dB (km\2\)
------------------------------------------------------------------------
Shallow........................... 5-21 346
Mid-Depth......................... 21-38 458
Deep.............................. 38-54 455
------------------------------------------------------------------------
(2) Pingers
These instruments will be operated during survey operations to
determine the exact position of the nodes after they have been placed
on the seafloor. One device, the Scout Ultra-Short Baseline
Transceiver, operates at frequencies between 33 and 55 kHz with a
source level of 188 dB re 1 [mu]Pa at 1 m. The other device, an LR
Ultra-Short Baseline Transponder, operates at a frequency of 35-50 kHz
at a source level of 185 dB re 1 [mu]Pa at 1 m. With respect to these
two sources, Apache provided and NMFS will rely on the distances to the
Level B harassment thresholds estimated for the ``louder'' of the two;
therefore, assuming a simple spreading loss of 20 log R (where R is
radius), with a source level of 188 dB the distance to the 190, 180,
and 160 dB isopleths would be 1, 3, and 25 m, respectively. Another
technique for locating the nodes in deeper water is called Ocean Bottom
Receiver Location, which uses a small volume air gun (10 in\3\) firing
parallel to the node line.
(3) Detonations of Explosives
The onshore areas will be surveyed using explosives as the sound
source. Seismic surveys on land use ``shot holes'' that are drilled
every 50 m along source lines and are oriented perpendicular to the
receiver lines and parallel to the coast. At each source location,
Apache will drill to the prescribed hole depth of approximately 10 m
and load it with 4 kg of explosives. The hole is then capped with a
``smart cap'' that makes it impossible to detonate the explosive
without the proper detonator. During the 2D test program conducted in
March 2011, Apache deployed acoustic recorders to measure underwater
sound produced by land-based explosives; however, the resulting
measurements were inconclusive and Apache has proposed a sound source
verification study to characterize the underwater received sound levels
and determine if marine mammal monitoring will be required for future
onshore operations.
Apache successfully measured the sounds produced by the air guns
and pingers during the 2D test program conducted in March 2011 and
found levels to be consistent with the modeled mitigation threshold
levels (180 dB for cetaceans, 190 dB for pinnipeds); therefore, except
for the measurements of in-water sound produced by detonations of
explosives on shore, a sound source verification study will not be
included in the proposed 3D seismic survey.
Description of Marine Mammals in the Area of the Specified Activity
The marine mammal species under NMFS's jurisdiction that could
occur near operations in Cook Inlet include three cetacean species:
beluga whale (Delphinapterus leucas), killer whale (Orcinus orca), and
harbor porpoise (Phocoena phocoena), and two pinniped species: harbor
seal (Phoca vitulina richardsi) and Steller sea lions (Eumetopias
jubatus). The marine mammal species that is likely to be encountered
most widely (in space and time) throughout the period of the planned
surveys is the harbor seal.
The Cook Inlet beluga whale and western population of Steller sea
lion are listed as ``endangered'' under the Endangered Species Act
(ESA) and as depleted under the MMPA. The site of the proposed survey
is within designated critical habitat for Cook Inlet beluga whales.
Apache's application contains information on the status,
distribution, seasonal distribution, and abundance of each of the
species under NMFS jurisdiction mentioned in this document. Please
refer to the application for that information (see ADDRESSES).
Additional information can also be found in the NMFS Stock Assessment
Reports (SAR). The Alaska 2010 SAR is available at: https://www.nmfs.noaa.gov/pr/pdfs/sars/ak2010.pdf.
Potential Effects of the Specified Activity on Marine Mammals
Operating active acoustic sources, such as air gun arrays, has the
potential for adverse effects on marine mammals.
Potential Effects of Air Gun Sounds on Marine Mammals
The effects of sounds from air gun pulses might include one or more
of the following: tolerance, masking of natural sounds, behavioral
disturbance, and temporary or permanent hearing impairment or non-
auditory effects (Richardson et al. 1995). As outlined in previous NMFS
documents, the effects of noise on marine mammals are highly variable,
and can be categorized as follows (based on Richardson et al. 1995):
(1) Tolerance
Numerous studies have shown that pulsed sounds from air guns are
often readily detectable in the water at distances of many kilometers.
Numerous studies have also shown that marine mammals at distances more
than a few kilometers from operating survey vessels often show no
apparent response. That is often true even in cases when the pulsed
sounds must be readily audible to the animals based on measured
received levels and the hearing sensitivity of that mammal group.
Although various toothed whales, and (less frequently) pinnipeds have
been shown to react behaviorally to air gun pulses under some
conditions, at other times, mammals of both types have shown no overt
reactions. In general, pinnipeds and
[[Page 58476]]
small odontocetes seem to be more tolerant of exposure to air gun
pulses than baleen whales.
(2) Behavioral Disturbance
Marine mammals may behaviorally react to sound when exposed to
anthropogenic noise. These behavioral reactions are often shown as:
changing durations of surfacing and dives, number of blows per
surfacing, or moving direction and/or speed; reduced/increased vocal
activities; changing/cessation of certain behavioral activities (such
as socializing or feeding); visible startle response or aggressive
behavior (such as tail/fluke slapping or jaw clapping); avoidance of
areas where noise sources are located; and/or flight responses (e.g.,
pinnipeds flushing into water from haulouts or rookeries).
The biological significance of many of these behavioral
disturbances is difficult to predict, especially if the detected
disturbances appear minor. However, the consequences of behavioral
modification have the potential to be biologically significant if the
change affects growth, survival, and reproduction. Examples of
significant behavioral modifications include:
Drastic change in diving/surfacing patterns (such as those
thought to be causing beaked whale stranding due to exposure to
military mid-frequency tactical sonar);
Habitat abandonment due to loss of desirable acoustic
environment; and
Cease feeding or social interaction.
For example, at the Guerreo Negro Lagoon in Baja California,
Mexico, which is one of the important breeding grounds for Pacific gray
whales, shipping and dredging associated with a salt works may have
induced gray whales to abandon the area through most of the 1960s
(Bryant et al. 1984). After these activities stopped, the lagoon was
reoccupied, first by single whales and later by cow-calf pairs.
The onset of behavioral disturbance from anthropogenic noise
depends on both external factors (characteristics of noise sources and
their paths) and the receiving animals (hearing, motivation,
experience, demography) and is also difficult to predict (Southall et
al. 2007).
Currently NMFS uses a received level of 160 dB re 1 [mu]Pa for
impulse noises (such as air gun pulses) as the onset threshold for
marine mammal behavioral harassment.
(3) Masking
Chronic exposure to excessive, though not high-intensity, noise
could cause masking at particular frequencies for marine mammals that
utilize sound for vital biological functions. Masking can interfere
with detection of acoustic signals such as communication calls,
echolocation sounds, and environmental sounds important to marine
mammals. Since marine mammals depend on acoustic cues for vital
biological functions, such as orientation, communication, finding prey,
and avoiding predators, marine mammals that experience severe acoustic
masking (e.g., of a high-intensity level over a long period of time
throughout a biologically important behavior) could experience
biologically significant effects that could potentially adversely
impact survival or reproductive success.
Masking occurs when noise and signals (that the animal utilizes)
overlap at both spectral and temporal scales. For the air gun noise
generated from the proposed seismic surveys, noise will consist of low
frequency (under 500 Hz) pulses with extremely short durations (less
than one second). Lower frequency man-made noises are more likely to
affect detection of communication calls and other potentially important
natural sounds such as surf and prey noise. There is little concern
regarding masking near the noise source due to the brief duration of
these pulses and relatively longer silence between air gun shots
(approximately 12 seconds). However, at long distances (over tens of
kilometers away), due to multipath propagation and reverberation, the
durations of air gun pulses can be ``stretched'' to seconds with long
decays (Madsen et al. 2006), although the intensity of the noise is
greatly reduced.
This could affect communication signals used by low frequency
mysticetes when they occur near the noise band and thus reduce the
communication space of animals (e.g., Clark et al. 2009) and cause
increased stress levels (e.g., Foote et al. 2004; Holt et al. 2009);
however, no baleen whales are expected to occur within the action area.
Marine mammals are thought to be able to compensate for masking by
adjusting their acoustic behavior by shifting call frequencies, and/or
increasing call volume and vocalization rates. For example, blue whales
are found to increase call rates when exposed to seismic survey noise
in the St. Lawrence Estuary (Di Iorio and Clark 2010). The North
Atlantic right whales (Eubalaena glacialis) exposed to high shipping
noise increase call frequency (Parks et al. 2007), while some humpback
whales respond to low-frequency active sonar playbacks by increasing
song length (Miller el al. 2000).
(4) Hearing Impairment
Marine mammals exposed to high intensity sound repeatedly or for
prolonged periods can experience hearing threshold shift (TS), which is
the loss of hearing sensitivity at certain frequency ranges (Kastak et
al. 1999; Schlundt et al. 2000; Finneran et al. 2002; 2005). TS can be
permanent (PTS), in which case the loss of hearing sensitivity is
unrecoverable, or temporary (TTS), in which case the animal's hearing
threshold will recover over time (Southall et al. 2007). Just like
masking, marine mammals that suffer from PTS or TTS will have reduced
fitness in survival and reproduction, either permanently or
temporarily. Repeated noise exposure that leads to TTS could cause PTS.
For transient sounds, the sound level necessary to cause TTS is
inversely related to the duration of the sound.
Experiments on a bottlenose dolphin (Tursiops truncatus) and beluga
whale showed that exposure to a single water gun impulse at a received
level of 207 kPa (or 30 psi) peak-to-peak (p-p), which is equivalent to
228 dB re 1 [mu]Pa (p-p), resulted in a 7 and 6 dB TTS in the beluga
whale at 0.4 and 30 kHz, respectively. Thresholds returned to within 2
dB of the pre-exposure level within 4 minutes of the exposure (Finneran
et al. 2002). No TTS was observed in the bottlenose dolphin. Although
the source level of pile driving from one hammer strike is expected to
be much lower than the single water gun impulse cited here, animals
being exposed for a prolonged period to repeated hammer strikes could
receive more noise exposure in terms of SEL than from the single water
gun impulse (estimated at 188 dB re 1 [mu]Pa\2\-s) in the
aforementioned experiment (Finneran et al. 2002).
In pinnipeds, TTS thresholds associated with exposure to brief
pulses (single or multiple) of underwater sound have not been measured.
Initial evidence from prolonged exposures suggested that some pinnipeds
may incur TTS at somewhat lower received levels than do small
odontocetes exposed for similar durations (Kastak et al. 1999, 2005;
Ketten et al. 2001). However, more recent indications are that TTS
onset in the most sensitive pinniped species studied (harbor seal,
which is closely related to the ringed seal) may occur at a similar SEL
as in odontocetes (Kastak et al., 2004).
NMFS (1995, 2000) concluded that cetaceans and pinnipeds should not
be exposed to pulsed underwater noise at received levels exceeding 180
and 190 dB re 1 [mu]Pa rms, respectively. The
[[Page 58477]]
established 180- and 190-dB re 1 [mu]Pa rms criteria are not considered
to be the levels above which TTS might occur. Rather, they are the
received levels above which, in the view of a panel of bioacoustics
specialists convened by NMFS before TTS measurements for marine mammals
started to become available, one could not be certain that there would
be no injurious effects, auditory or otherwise, to marine mammals. As
summarized above, data that are now available imply that TTS is
unlikely to occur unless bow-riding odontocetes are exposed to air gun
pulses much stronger than 180 dB re 1 [micro]Pa rms (Southall et al.
2007).
No cases of TTS are expected as a result of Apache's proposed
activities given the strong likelihood that marine mammals would avoid
the approaching air guns (or vessel) before being exposed to levels
high enough for there to be any possibility of TTS, and the mitigation
measures proposed to be implemented during the survey described later
in this document.
There is no empirical evidence that exposure to pulses of air gun
sound can cause PTS in any marine mammal, even with large arrays of air
guns (see Southall et al., 2007). However, given the possibility that
mammals close to an air gun array might incur TTS, there has been
further speculation about the possibility that some individuals
occurring very close to air guns might incur PTS. Single or occasional
occurrences of mild TTS are not indicative of permanent auditory damage
in terrestrial mammals. Relationships between TTS and PTS thresholds
have not been studied in marine mammals, but are assumed to be similar
to those in humans and other terrestrial mammals. That is, PTS might
occur at a received sound level magnitudes higher than the level of
onset TTS, or by repeated exposure to the levels that cause TTS.
Therefore, by means of preventing the onset of TTS, it is highly
unlikely that marine mammals could receive sounds strong enough (and
over a sufficient duration) to cause permanent hearing impairment
during the proposed marine surveys in Cook Inlet.
(5) Non-auditory Physical Effects
Non-auditory physical effects might occur in marine mammals exposed
to strong underwater pulsed sound. Possible types of non-auditory
physiological effects or injuries that theoretically might occur in
mammals close to a strong sound source include stress, neurological
effects, bubble formation, and other types of organ or tissue damage.
Some marine mammal species (i.e., beaked whales) may be especially
susceptible to injury and/or stranding when exposed to strong pulsed
sounds. However, there is no definitive evidence that any of these
effects occur even for marine mammals in close proximity to large
arrays of air guns, and beaked whales do not occur in the proposed
project area. In addition, marine mammals that show behavioral
avoidance of seismic vessels, including most baleen whales, some
odontocetes (including belugas), and some pinnipeds, are especially
unlikely to incur non-auditory impairment or other physical effects.
The distances to the 180 and 190 dB thresholds for the air gun array
proposed to be used by Apache are provided above in Tables 1 and 2.
Therefore, it is unlikely that such effects would occur during
Apache's proposed surveys given the brief duration of exposure and the
planned monitoring and mitigation measures described later in this
document.
(6) Stranding and Mortality
Marine mammals close to underwater detonations of high explosive
can be killed or severely injured, and the auditory organs are
especially susceptible to injury (Ketten et al. 1993; Ketten 1995). Air
gun pulses are less energetic and their peak amplitudes have slower
rise times. To date, there is no evidence that serious injury, death,
or stranding by marine mammals can occur from exposure to air gun
pulses, even in the case of large air gun arrays.
However, in numerous past IHA notices for seismic surveys,
commenters have referenced two stranding events allegedly associated
with seismic activities, one off Baja California and a second off
Brazil. NMFS has addressed this concern several times, and, without new
information, does not believe that this issue warrants further
discussion. For information relevant to strandings of marine mammals,
readers are encouraged to review NMFS' response to comments on this
matter found in 69 FR 74905 (December 14, 2004), 71 FR 43112 (July 31,
2006), 71 FR 50027 (August 24, 2006), and 71 FR 49418 (August 23,
2006). In addition, a May-June 2008, stranding of 100-200 melon-headed
whales (Peponocephala electra) off Madagascar that appears to be
associated with seismic surveys is currently under investigation (IWC
2009).
It should be noted that strandings related to sound exposure have
not been recorded for marine mammal species in Cook Inlet. NMFS notes
that beluga whale strandings in Cook Inlet are not uncommon; however,
these events often coincide with extreme tidal fluctuations (``spring
tides'') or killer whale sightings (Shelden et al., 2003). No
strandings or marine mammals in distress were observed during the 2D
test survey conducted by Apache in March 2011 and none were reported by
Cook Inlet inhabitants. As a result, NMFS does not expect any marine
mammals will incur serious injury or mortality in Cook Inlet or strand
as a result of the proposed seismic survey.
Potential Effects From Other Sound Sources on Marine Mammals
Active acoustic sources other than the air gun arrays have been
proposed for Apache's seismic survey in Cook Inlet. The specifications
for this equipment (source levels and frequency ranges) are provided
above. In general, the potential effects of this equipment on marine
mammals are similar to those from the air gun, except the magnitude of
the impacts is expected to be much less due to the lower intensity and
higher frequencies. Estimated source levels from these devices are
discussed above.
Vessel Sounds
In addition to the noise generated from seismic air guns and active
sonar systems, various types of vessels will be used in the operations,
including source vessels and the vessel used for placing and retrieving
the nodal recording system. Sounds from boats and vessels have been
reported extensively (Greene and Moore 1995; Blackwell and Greene 2002;
2005; 2006). Measurements of underwater vessel sound have been
performed in upper Cook Inlet. For example, Blackwell and Greene (2002)
conducted a survey that measured in-water noise from various sources in
Cook Inlet, including a tug boat docking a barge. The highest SPL
recorded for the working tug under load was 149 dB re 1 [micro]Pa, at a
distance of about 90 m, with an extrapolated SPL at 0.9 m of 178.9 dB
re 1 [micro]Pa. Compared to air gun pulses, underwater sound from
vessels is generally at relatively low frequencies.
The primary sources of sounds from all vessel classes are propeller
cavitation, propeller singing, and propulsion or other machinery.
Propeller cavitation is usually the dominant noise source for vessels
(Ross 1976). Propeller cavitation and singing are produced outside the
hull, whereas propulsion or other machinery noise originates inside the
hull. There are additional sounds produced by vessel activity, such as
pumps, generators, flow noise from water passing over the hull, and
bubbles breaking in the wake.
[[Page 58478]]
Land-Based Explosives
The onshore component of the seismic survey involves the
underground detonation of explosive devices to acquire seismic data on
land. Because underwater sound levels associated with the land-based
explosives are currently unknown, Apache proposes to conduct a sound
source verification (SSV) study to ensure that marine mammals are not
exposed to underwater sound levels that exceed the NMFS injury or
harassment thresholds. This study is expected to take two days to
complete and a report will be submitted to NMFS prior to making a final
determination on whether to issue or deny the IHA. The study will
include a robust marine mammal monitoring plan to ensure that marine
mammals are not harassed or injured. For example, Apache proposes to
conduct visual monitoring using vessel-based and aerial platforms. In
addition, the SSV will only take place during daylight hours with good
visibility. Following the completion of the study, a SSV report will be
submitted to NMFS. The report will describe the operations that were
conducted and the marine mammals that were observed. The report will
provide full documentation of the methods, results, and interpretations
pertaining to all monitoring and will contain information on the need
to implement marine mammal monitoring during land-based operations.
Anticipated Effects on Marine Mammal Habitat
The primary potential impacts to marine mammal habitat and other
marine species are associated with elevated sound levels produced by
airguns and other active acoustic sources. However, other potential
impacts to the surrounding habitat from physical disturbance are also
possible and are discussed below.
Potential Impacts on Prey Species
With regard to fish as a prey source for cetaceans and pinnipeds,
fish are known to hear and react to sounds and to use sound to
communicate (Tavolga et al. 1981) and possibly avoid predators (Wilson
and Dill 2002). Experiments have shown that fish can sense both the
strength and direction of sound (Hawkins 1981). Primary factors
determining whether a fish can sense a sound signal, and potentially
react to it, are the frequency of the signal and the strength of the
signal in relation to the natural background noise level.
The level of sound at which a fish will react or alter its behavior
is usually well above the detection level. Fish have been found to
react to sounds when the sound level increased to about 20 dB above the
detection level of 120 dB (Ona 1988); however, the response threshold
can depend on the time of year and the fish's physiological condition
(Engas et al. 1993). In general, fish react more strongly to pulses of
sound rather than a continuous signal (Blaxter et al. 1981), and a
quicker alarm response is elicited when the sound signal intensity
rises rapidly compared to sound rising more slowly to the same level.
Investigations of fish behavior in relation to vessel noise (Olsen
et al. 1983; Ona 1988; Ona and Godo 1990) have shown that fish react
when the sound from the engines and propeller exceeds a certain level.
Avoidance reactions have been observed in fish such as cod and herring
when vessels approached close enough that received sound levels are 110
dB to 130 dB (Nakken 1992; Olsen 1979; Ona and Godo 1990; Ona and
Toresen 1988). However, other researchers have found that fish such as
polar cod, herring, and capeline are often attracted to vessels
(apparently by the noise) and swim toward the vessel (Rostad et al.
2006). Typical sound source levels of vessel noise in the audible range
for fish are 150 dB to 170 dB (Richardson et al. 1995).
Potential Impacts to the Benthic Environment
Apache's seismic survey requires the deployment of a submersible
recording system in the inter-tidal and marine zones. An autonomous
``nodal'' (i.e., no cables) system will be placed on the seafloor by
specific vessels in lines parallel to each other with a node line
spacing of 402 m. Each nodal ``patch'' will have six to eight node
lines parallel to each other. The lines generally run perpendicular to
the shoreline. An entire patch will be placed on the seafloor prior to
air gun activity. As the patches are surveyed, the node lines will be
moved either side to side or inline to the next location. Placement and
retrieval of the nodes may cause temporary and localized increases in
turbidity on the seafloor. The substrate of Cook Inlet consists of
glacial silt, clay, cobbles, pebbles, and sand (Sharma and Burrell,
1970). Sediments like sand and cobble dissipate quickly when suspended,
but finer materials like clay and silt can create thicker plumes that
may harm fish; however, the turbidity created by placing and removing
nodes on the seafloor will settle to background levels within minutes
after the cessation of activity.
Based on the preceding discussion, the proposed activity is not
expected to have any habitat-related effects that could cause
significant or long-term consequences for individual marine mammals or
their populations.
Proposed Mitigation
In order to issue an incidental take authorization under section
101(a)(5)(D) of the MMPA, NMFS must set forth the permissible methods
of taking pursuant to such activity, and other means of effecting the
least practicable adverse impact on such species or stock and its
habitat, paying particular attention to rookeries, mating grounds, and
areas of similar significance, and on the availability of such species
or stock for taking for certain subsistence uses.
For the proposed seismic survey in Cook Inlet, Apache worked with
NMFS and proposed the following mitigation measures to minimize the
potential impacts to marine mammals in the project vicinity as a result
of the survey activities.
Mitigation Measures Proposed in Apache's IHA Application
For the proposed mitigation measures, Apache listed the following
protocols to be implemented during its seismic survey in Cook Inlet.
(1) Operation of Mitigation Air Gun at Night
Apache proposes to conduct both daytime and nighttime operations.
Nighttime operations will only be initiated if a mitigation air gun
(typically the 10 in\3\) has been continuously operational from the
time that PSO monitoring has ceased for the day. Seismic activity will
not ramp up from an extended shut-down during nighttime operations
because dedicated PSOs will not be on duty and any unseen animals may
be exposed to injurious levels of sound from the full array. At night,
the vessel captain and crew will maintain lookout for marine mammals
and will order the air gun(s) to be shut down if marine mammals are
observed in or about to enter the safety radii. If a shut-down occurs
during nighttime operations, seismic survey activity will be suspended
until the following day and will only be resumed if the full safety
zone is visible.
(2) Safety and Disturbance Zones
Under current NMFS guidelines, ``safety radii'' for marine mammal
exposure to impulse sources are customarily defined as the distances
within which received sound levels are >=180 dBrms re 1
[mu]Pa for cetaceans and >=190 dBrms re 1 [mu]Pa for
pinnipeds. These
[[Page 58479]]
safety criteria are based on an assumption that SPL received at levels
lower than these will not injure these animals or impair their hearing
abilities, but that SPL received at higher levels might have some such
effects. Disturbance or behavioral effects to marine mammals from
underwater sound may occur after exposure to sound at distances greater
than the safety radii (Richardson et al. 1995).
The proposed surveys will use an air gun sources composed of two
2400 in\3\ air guns, a single 440 in\3\ air gun, and a single 10 in\3\
air gun. Safety and disturbance radii for the sound levels produced by
the planned airgun configurations have been estimated (Tables 1 and 2)
and will be used for mitigation purposes during the seismic survey
activities.
In addition to the marine mammal monitoring radii described above,
pursuant to Alaska Department of Fish and Game restrictions, there will
be a 1.6 km setback of sound source points from the mouths of any
anadromous streams.
Apache also plans to use dedicated vessels to deploy and retrieve
the nodal recording system. Sounds produced by the vessels are not
expected to exceed 180 dB (rms). Therefore, mitigation related to
acoustic impacts from these activities is not expected to be necessary.
An acoustics contractor will perform direct measurements of the
received levels of underwater sound versus distance and direction from
the detonation of explosives onshore using calibrated hydrophones. The
acoustic data will be analyzed as quickly as reasonably practicable in
the field and used to determine whether the detonation of explosives
onshore exposes marine mammals to underwater sound levels that may
result in Level B harassment. The field report will be made available
to NMFS prior to the final determination on whether to issue or deny
the IHA. If necessary, mitigation measures similar to those proposed
for the other sound sources (i.e., establishment of 160, 180, and 190
dB isopleths with dedicated monitoring and detonation delay procedures)
will be implemented for this aspect of the seismic survey.
(3) Speed and Course Alterations
If a marine mammal is detected outside the applicable safety radius
and, based on its position and the relative motion, is likely to enter
the safety radius, changes of the vessel's speed and/or direct course
will be considered if this does not compromise operational safety. For
marine seismic surveys using large arrays, course alterations are not
typically possible. However, for the smaller air gun arrays planned
during the proposed site surveys, such changes may be possible. After
any such speed and/or course alteration is begun, the marine mammal
activities and movements relative to the survey vessel will be closely
monitored to ensure that the marine mammal does not approach within the
safety radius. If the mammal appears likely to enter the safety radius,
further mitigative actions will be taken, including a power down or
shut down of the airgun(s).
(4) Power-Downs
A power-down for mitigation purposes is the immediate reduction in
the number of operating airguns such that the radii of the 190 dB rms
and 180 dB rms zones are decreased to the extent that an observed
marine mammal(s) are not in the applicable safety zone of the full
array. During a power-down, one air gun, typically the 10 in\3\,
continues firing. Operation of the 10 in\3\ air gun decreases the
safety radii to 10 m, 33 m, and 330 m for the 190 dB, 180 dB, and 160
dB, respectively. The continued operation of one airgun is intended to
(a) alert marine mammals to the presence of the survey vessel in the
area, and (b) retain the option of initiating a ramp up to full
operations under poor visibility conditions.
The array will be immediately powered down whenever a marine mammal
is sighted approaching close to or within the applicable safety zone of
the full array, but is outside the applicable safety zone of the single
mitigation airgun. Likewise, if a mammal is already within the safety
zone when first detected, the airguns will be powered down immediately.
If a marine mammal is sighted within or about to enter the applicable
safety zone of the single mitigation airgun, it too will be shut down
(see following section).
Following a power-down, operation of the full airgun array will not
resume until the marine mammal has cleared the safety zone. The animal
will be considered to have cleared the safety zone if it
Is visually observed to have left the safety zone of the
full array, or
Has not been seen within the zone for 15 min in the case
of pinnipeds or small odontocetes, or
Has not been seen within the zone for 30 min in the case
of large odontocetes.
(5) Shut-Downs
The operating air gun(s) will be shut down completely if a marine
mammal approaches or enters the safety radius and a power-down is not
practical or adequate to reduce exposure to less than 190 or 180 dB
rms, as appropriate. In most cases, this means the mitigation airgun
will be shut down completely if a marine mammal approaches or enters
the estimated safety radius around the single 10 in\3\ air gun while it
is operating during a power down. Air gun activity will not resume
until the marine mammal has cleared the safety radius. The animal will
be considered to have cleared the safety radius as described above
under power down procedures.
(6) Ramp Ups
A ramp up of an air gun array provides a gradual increase in sound
levels, and involves a step-wise increase in the number and total
volume of air guns firing until the full volume is achieved. The
purpose of a ramp-up (or ``soft start'') is to ``warn'' cetaceans and
pinnipeds in the vicinity of the air guns and to provide the time for
them to leave the area and thus avoid any potential injury or
impairment of their hearing abilities.
During the proposed seismic survey, the seismic operator will ramp
up the airgun cluster slowly. Full ramp-ups (i.e., from a cold start
after a shut-down, when no airguns have been firing) will begin by
firing a single airgun in the array. The minimum duration of a shut-
down period, i.e., without air guns firing, which must be followed by a
ramp-up is typically the amount of time it would take the source vessel
to cover the 180-dB safety radius. Given the size of the planned air
gun arrays, that period is estimated to be about 1-2 minutes based on
the modeling results described above and a survey speed of 2-4 kts.
A full ramp up, after a shut down, will not begin until there has
been a minimum of 30 minutes of observation of the safety zone by PSOs
to assure that no marine mammals are present. The entire safety zone
must be visible during the 30-minute lead-in to a full ramp up. If the
entire safety zone is not visible, then ramp up from a cold start
cannot begin. If a marine mammal(s) is sighted within the safety zone
during the 30-minute watch prior to ramp up, ramp up will be delayed
until the marine mammal(s) is sighted outside of the safety zone or the
animal(s) is not sighted for at least 15-30 minutes: 15 minutes for
small odontocetes and pinnipeds, or 30 minutes for large odontocetes.
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Additional Mitigation Measures Proposed by NMFS
Besides Apache's proposed mitigation measures discussed above, NMFS
proposes the following additional protective measures to address some
uncertainties regarding the impacts of seismic surveys on beluga whale
cow-calf pairs and aggregations of whales. Specifically, NMFS proposes
that a 160-dB vessel monitoring zone will be established and monitored
in Cook Inlet during all seismic surveys. Whenever an aggregation of
beluga whales, killer whales, or harbor porpoises (five or more whales
of any age/sex class that appear to be engaged in a non-migratory,
significant biological behavior (e.g., feeding, socializing)) are
observed approaching the 160-dB safety zone around the survey
operations, the survey activity will not commence or will shut down,
until they are no longer present within the 160-dB safety zone of
seismic surveying operations.
Furthermore, NMFS proposes the following measures be included in
the IHA, if issued, in order to ensure the least practicable impact on
the affected species or stocks:
(1) All vessels should reduce speed when within 300 yards (274 m)
of whales, and those vessels capable of steering around such groups
should do so. Vessels may not be operated in such a way as to separate
members of a group of whales from other members of the group;
(2) Avoid multiple changes in direction and speed when within 300
yards (274 m) of whales; and
(3) When weather conditions require, such as when visibility drops,
support vessels must adjust speed (increase or decrease) and direction
accordingly to avoid the likelihood of injury to whales.
Mitigation Conclusions
NMFS has carefully evaluated the applicant's proposed mitigation
measures and considered a range of other measures in the context of
ensuring that NMFS prescribes the means of effecting the least
practicable impact on the affected marine mammal species and stocks and
their habitat. Our evaluation of potential measures included
consideration of the following factors in relation to one another:
The manner in which, and the degree to which, the
successful implementation of the measure is expected to minimize
adverse impacts to marine mammals;
The proven or likely efficacy of the specific measure to
minimize adverse impacts as planned; and
The practicability of the measure for applicant
implementation.
Based on our evaluation of the applicant's proposed measures, as
well as other measures considered by NMFS, NMFS has preliminarily
determined that the proposed mitigation measures provide the means of
effecting the least practicable impact on marine mammal species or
stocks and their habitat, paying particular attention to rookeries,
mating grounds, and areas of similar significance.
Proposed Monitoring and Reporting
In order to issue an ITA for an activity, section 101(a)(5)(D) of
the MMPA states that NMFS must set forth ``requirements pertaining to
the monitoring and reporting of such taking''. The MMPA implementing
regulations at 50 CFR 216.104(a)(13) indicate that requests for ITAs
must include the suggested means of accomplishing the necessary
monitoring and reporting that will result in increased knowledge of the
species and of the level of taking or impacts on populations of marine
mammals that are expected to be present in the proposed action area.
Monitoring Measures Proposed in Apache's IHA Application
The monitoring plan proposed by Apache can be found in section 13
of the IHA application. The plan may be modified or supplemented based
on comments or new information received from the public during the
public comment period. A summary of the primary components of the plan
follows.
(1) Visual Vessel-Based Monitoring
Vessel-based monitoring for marine mammals will be done by
experienced PSOs throughout the period of marine survey activities.
PSOs will monitor the occurrence and behavior of marine mammals near
the survey vessel during all daylight periods during operation and
during most daylight periods when airgun operations are not occurring.
PSO duties will include watching for and identifying marine mammals,
recording their numbers, distances, and reactions to the survey
operations, and documenting ``take by harassment'' as defined by NMFS.
A sufficient number of PSOs will be required onboard the survey
vessel to meet the following criteria: (1) 100 percent monitoring
coverage during all periods of survey operations in daylight; (2)
maximum of 4 consecutive hours on watch per PSO; and (3) maximum of 12
hours of watch time per day per PSO.
PSO teams will consist of experienced field biologists. An
experienced field crew leader will supervise the PSO team onboard the
survey vessel. Apache currently plans to have PSOs aboard the three
vessels: the two source vessels (M/V Peregrine Falcon and M/V Arctic
Wolf) and one support vessel (M/V Dreamcatcher). Two PSOs will be on
the source vessels and two PSOs will be on the support vessel to
observe the safety, power down, and shut down areas. When marine
mammals are about to enter or are sighted within designated safety
zones, air gun or pinger operations will be powered down (when
applicable) or shut down immediately. The vessel-based observers will
watch for marine mammals during all periods when sound sources are in
operation and for a minimum of 30 minutes prior to the start of air gun
or pinger operations after an extended shut down.
Crew leaders and most other biologists serving as observers will be
individuals with experience as observers during seismic surveys in
Alaska or other areas in recent years.
The observer(s) will watch for marine mammals from the best
available vantage point on the source and support vessels, typically
the flying bridge. The observer(s) will scan systematically with the
unaided eye and 7 x 50 reticle binoculars. Laser range finders will be
available to assist with estimating distance. Personnel on the bridge
will assist the observer(s) in watching for marine mammals.
All observations will be recorded in a standardized format. Data
will be entered into a custom database using a notebook computer. The
accuracy of the data will be verified by computerized validity data
checks as the data are entered and by subsequent manual checks of the
database. These procedures will allow for initial summaries of the data
to be prepared during and shortly after the completion of the field
program, and will facilitate transfer of the data to statistical,
geographical, or other programs for future processing and achieving.
When a mammal sighting is made, the following information about the
sighting will be recorded:
(A) Species, group size, age/size/sex categories (if determinable),
behavior when first sighted and after initial sighting, heading (if
consistent), bearing and distance from the PSO, apparent reaction to
activities (e.g., none, avoidance, approach, paralleling, etc.),
closest point of approach, and behavioral pace;
(B) Time, location, speed, activity of the vessel, sea state, ice
cover, visibility, and sun glare; and
(C) The positions of other vessel(s) in the vicinity of the PSO
location.
[[Page 58481]]
The ship's position, speed of support vessels, and water
temperature, water depth, sea state, ice cover, visibility, and sun
glare will also be recorded at the start and end of each observation
watch, every 30 minutes during a watch, and whenever there is a change
in any of those variables.
(2) Visual Shore-Based Monitoring
In addition to the vessel-based PSOs, Apache proposes to utilize a
shore-based station to visually monitor for marine mammals. The shore-
based station will follow all safety procedures, including bear safety.
The location of the shore-based station will need to be sufficiently
high to observe marine mammals; the PSOs would be equipped with
pedestal mounted ``big eye'' (20 x 110) binoculars. The shore-based
PSOs would scan the area prior to, during, and after the air gun
operations, and would be in contact with the vessel-based PSOs via
radio to communicate sightings of marine mammals approaching or within
the project area.
(3) Aerial-Based Monitoring
When practicable, Apache proposes to utilize the crew helicopter to
conduct aerial surveys near river mouths prior to the commencement of
air gun operations in order to identify locations where beluga whales
congregate. The helicopter will not be used every day, but will be used
when survey operations occur near a river mouth. The types of
helicopters currently planned for use by Apache include a Bell 407,
Bell UH1B, and ASB3. Weather and scheduling permitting, aerial surveys
will fly at an altitude of 305 m (1,000 ft). In the event of a marine
mammal sighting, aircraft will attempt to maintain a radial distance of
457 m (1,500 ft) from the marine mammal(s). Aircraft will avoid
approaching marine mammals from head-on, flying over or passing the
shadow of the aircraft over the marine mammal(s). By following these
operational requirements, sound levels underwater are not expected to
meet or exceed NMFS harassment thresholds (Richardson et al., 1995;
Blackwell et al., 2002).
(4) Acoustic Monitoring
To further enhance detection of cetaceans, Apache proposes to
deploy passive acoustic monitoring (PAM) devices during the seismic
survey. According to Apache's IHA application, the actual PAM system
has not been identified; however, Apache anticipates utilizing the same
system that was deployed during the 2D test program in March 2011 in
Cook Inlet. Apache expects to deploy two PAM devices that will send
real-time acoustic data via digital UHF radio-broadcast systems to the
PAM operators aboard the M/V Dreamcatcher. The PAM operators will use
specialized real-time detection software and audio playback to detect
marine mammal sounds. If the PAM operators detect marine mammals,
Apache will initiate a temporary shut-down of the air gun arrays to
avoid takes. Following a shut-down, the air guns may be restarted in
accordance with the ramp-up procedure described earlier.
Reporting Measures
(1) SSV Report on In-Water Noise From Explosives Onshore
A report on the preliminary results of the acoustic verification
measurements, including as a minimum the measured 190-, 180-, and 160-
dBrms re 1 [mu]Pa radii of the onshore explosive
detonations, will be submitted prior to the publication of a Federal
Register notice announcing the issuance or denial of the IHA. If
applicable, this report will specify the distances of the safety zones
that will be adopted and monitored for the marine survey activities.
(2) Field Reports
During the proposed survey program, the PSOs will prepare a report
each day or at such other interval as the IHA (if issued), or Apache
may require, summarizing the recent results of the monitoring program.
The field reports will summarize the species and numbers of marine
mammals sighted. These reports will be provided to NMFS and to the
survey operators.
(3) Technical Report
The results of Apache's 2011 monitoring program, including
estimates of ``take'' by harassment, will be presented in the ``90-
day'' and Final Technical reports. The Technical Report will include:
(a) Summaries of monitoring effort (e.g., total hours, total
distances, and marine mammal distribution through the study period,
accounting for sea state and other factors affecting visibility and
detectability of marine mammals);
(b) Analyses of the effects of various factors influencing
detectability of marine mammals (e.g., sea state, number of observers,
and fog/glare);
(c) Species composition, occurrence, and distribution of marine
mammal sightings, including date, water depth, numbers, age/size/gender
categories (if determinable), group sizes, and ice cover;
(d) Analyses of the effects of survey operations;
Sighting rates of marine mammals during periods with and
without seismic survey activities (and other variables that could
affect detectability), such as:
Initial sighting distances versus survey activity state;
Closest point of approach versus survey activity state;
Observed behaviors and types of movements versus survey
activity state;
Numbers of sightings/individuals seen versus survey
activity state;
Distribution around the source vessels versus survey
activity state; and
Estimates of take by harassment.
(4) Comprehensive Report
Following the survey season, a comprehensive report describing the
vessel-based, shore-based, aerial-based, and acoustic monitoring
programs will be prepared. The comprehensive report will describe the
methods, results, conclusions and limitations of each of the individual
data sets in detail. The report will also integrate (to the extent
possible) the studies into a broad based assessment of industry
activities, and other activities that occur in Cook Inlet, and their
impacts on marine mammals. The report will help to establish long-term
data sets that can assist with the evaluation of changes in the Cook
Inlet ecosystem. The report will attempt to provide a regional
synthesis of available data on industry activity in this part of Alaska
that may influence marine mammal density, distribution and behavior.
(5) Notification of Injured or Dead Marine Mammals
In the unanticipated event that the specified activity clearly
causes the take of a marine mammal in a manner prohibited by the IHA
(if issued), such as an injury (Level A harassment), serious injury or
mortality (e.g., ship-strike, gear interaction, and/or entanglement),
Apache will immediately cease the specified activities and immediately
report the incident to the Chief of the Permits, Conservation, and
Education Division, Office of Protected Resources, NMFS, and the Alaska
Regional Stranding Coordinators. The report must include the following
information:
Time, date, and location (latitude/longitude) of the
incident;
Name and type of vessel involved;
Vessel's speed during and leading up to the incident;
Description of the incident;
Status of all sound source use in the 24 hours preceding
the incident;
Water depth;
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Environmental conditions (e.g., wind speed and direction,
Beaufort sea state, cloud cover, and visibility);
Description of all marine mammal observations in the 24
hours preceding the incident;
Species identification or description of the animal(s)
involved;
Fate of the animal(s); and
Photographs or video footage of the animal(s) (if
equipment is available).
Activities will not resume until NMFS is able to review the
circumstances of the prohibited take. NMFS will work with Apache to
determine what is necessary to minimize the likelihood of further
prohibited take and ensure MMPA compliance. Apache may not resume their
activities until notified by NMFS via letter, e-mail, or telephone.
In the event that Apache discovers an injured or dead marine
mammal, an