Incidental Takes of Marine Mammals During Specified Activities; Seismic Testing and Calibration in the Northern Gulf of Mexico, 45744-45754 [E7-16013]
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Federal Register / Vol. 72, No. 157 / Wednesday, August 15, 2007 / Notices
whales, beluga whales, ringed seals,
bearded seals and spotted seals; would
have a negligible impact on these
marine mammal stocks; and would not
have an unmitigable adverse impact on
the availability of marine mammal
stocks for subsistence.
Dated: August 9, 2007.
James H. Lecky,
Director, Office of Protected Resources,
National Marine Fisheries Service.
[FR Doc. E7–16011 Filed 8–14–07; 8:45 am]
BILLING CODE 3510–22–S
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric
Administration
[I.D. 050107H]
Incidental Takes of Marine Mammals
During Specified Activities; Seismic
Testing and Calibration in the Northern
Gulf of Mexico
National Marine Fisheries
Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA),
Commerce.
ACTION: Notice; issuance of incidental
harassment authorization.
ebenthall on PROD1PC69 with NOTICES
AGENCY:
SUMMARY: In accordance with the
Marine Mammal Protection Act
(MMPA) regulations, notification is
hereby given that NMFS has issued an
Incidental Harassment Authorization
(IHA) to the Lamont-Doherty Earth
Observatory (L-DEO) to take small
numbers of marine mammals, by Level
B Harassment only, incidental to
conducting an acoustic calibration and
seismic testing program in the northern
Gulf of Mexico.
DATES: Effective from July 31, 2007
through July 30, 2008.
ADDRESSES: A copy of the IHA, the
application, and the associated
Environmental Assessment (EA) and
Supplemental EA are available by
writing to Michael Payne, Chief,
Permits, Conservation, and Education
Division, Office of Protected Resources,
National Marine Fisheries Service, 1315
East-West Highway, Silver Spring, MD
20910–3225, or by telephoning the
contact listed here. A copy of the
application containing a list of
references used in this document may
be obtained by writing to this address,
by telephoning the contact listed here
(FOR FURTHER INFORMATION CONTACT) or
online at: https://www.nmfs.noaa.gov/pr/
permits/incidental.htm. Documents
cited in this notice may be viewed, by
appointment, during regular business
hours, at the aforementioned address.
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Jolie
Harrison, Office of Protected Resources,
NMFS, (301) 713–2289, ext 166.
FOR FURTHER INFORMATION CONTACT:
SUPPLEMENTARY INFORMATION:
Background
Sections 101(a)(5)(A) and (D) of the
MMPA (16 U.S.C. 1361 et seq.) direct
the Secretary of Commerce to allow,
upon request, the incidental, but not
intentional, taking of marine mammals
by U.S. citizens who engage in a
specified activity (other than
commercial fishing) within a specified
geographical region if certain findings
are made and either regulations are
issued or, if the taking is limited to
harassment, a notice of a proposed
authorization is provided to the public
for review.
Authorization shall be granted if
NMFS finds that the taking will have a
negligible impact on the species or
stock(s), will not have an unmitigable
adverse impact on the availability of the
species or stock(s) for subsistence uses,
and that the permissible methods of
taking and requirements pertaining to
the mitigation, monitoring and reporting
of such takings are set forth. NMFS has
defined ‘‘negligible impact’’ in 50 CFR
216.103 as ’’* * * an impact resulting
from the specified activity that cannot
be reasonably expected to, and is not
reasonably likely to, adversely affect the
species or stock through effects on
annual rates of recruitment or survival.’’
Section 101(a)(5)(D) of the MMPA
established an expedited process by
which citizens of the United States can
apply for an authorization to
incidentally take small numbers of
marine mammals by harassment. Except
with respect to certain activities not
pertinent here, the MMPA defines
‘‘harassment’’ as:
any act of pursuit, torment, or annoyance
which (i) has the potential to injure a marine
mammal or marine mammal stock in the wild
[Level A harassment]; or (ii) has the potential
to disturb a marine mammal or marine
mammal stock in the wild by causing
disruption of behavioral patterns, including,
but not limited to, migration, breathing,
nursing, breeding, feeding, or sheltering
[Level B harassment].
Section 101(a)(5)(D) establishes a 45day 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 issuance of the
authorization.
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Summary of Request
On June 2, 2006, NMFS received an
application from L-DEO for the taking,
by Level B harassment, of several
species of marine mammals incidental
to conducting, with research funding
from the National Science Foundation
(NSF), an acoustic calibration and
seismic testing program in the northern
Gulf of Mexico in Fall, 2006. This
project will be conducted with L-DEO’s
new seismic vessel, the R/V Marcus G
Langseth (Langseth), which will deploy
different configurations of airguns and a
different bottom-mapping sonar than
used previously by L-DEO. L-DEO
requests that it be issued an IHA
allowing Level B Harassment takes of
marine mammals incidental to the
planned seismic surveys in the Gulf of
Mexico. A detailed description of the
purpose of the calibration and testing
program was outlined in the NMFS
notice of the proposed IHA (71 FR
58790, October 5, 2006).
Description of the Specified Activity
The Langseth is expected to depart
Mobile, AL in July, 2007 (at the earliest)
and will transit to the survey area in the
northern Gulf of Mexico. The survey
will encompass an area between 24°N.
and 31°N. and between 83°W. and
96°W., which is within the Exclusive
Economic Zone (EEZ) of the U.S.A. The
study will consist of three phases: (1) an
initial testing/shakedown phase, (2)
measurements of the sounds produced
by various airgun arrays to be used by
the Langseth (calibration), and (3) a
three-dimensional (3D) seismic testing
phase. The entire survey, calibration
and testing included, will take
approximately 25 days and include
approximately 1420 km (174 hours) of
airgun operation. Measurements will be
made during seismic operations in three
categories of water depth: shallow (<100
m or <328 ft), intermediate/slope (100–
1000 m or 328–3281 ft), and deep
(>1000 m or >3281 ft). The vessel will
transit to Galveston after the study is
completed. The exact dates of the
activities will depend on logistics and
weather conditions.
The full airgun array on the Langseth
consists of 36 airguns, with a total
discharge volume of 6600 in3. The array
is made up of four identical linear
arrays or strings, with 10 airguns on
each string. For each operating string,
nine airguns will be fired
simultaneously, while the tenth is kept
in reserve as a spare, to be turned on in
case of failure of another airgun. The
calibration phase will use the full 36airgun array and subsets thereof. The
subsets will consist of either 1 string (9
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airguns, 1650 in3) or 2 strings (18
airguns, 3300 in3). In addition, sounds
from a single 45 in3 GI gun and 2 GI
guns (210 in3) will be measured. During
the seismic testing phase, the 2-string
array will be used at most times,
although the full 36-airgun array may
also be used. The ocean floor will be
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mapped with the 12-kHz Simrad EM120
MBB sonar. This sonar will be operated
from the Langseth simultaneous with
the airgun array during the seismic
testing program, but will likely be
operated on its own during the acoustic
calibration study.
A more detailed description of the
authorized action, including vessel
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specifications and acoustic source
specifications, was included in the
notice of the proposed IHA (71 FR
58790, October 5, 2006). Table 1
includes a summary of the use of the
airgun configurations by phase and
depth.
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89 km
24 km
24 km
24 km
175 km
175 km
175 km
45 km
34 km
34 km
252 (259)
6m
3300 in3
Eighteen 2000 psi Bolt
Airguns of 40–360 in3
18-Airgun Array (2
Strings)
Table 1. L-DEO airgun configurations and proposed approximate use for each configuration by depth and phase.
* The root mean square values (typically discussed in biological literature) for these sources will generally be about 10-15 dB lower than those reflected here.
Deep (<1000 m)
89 km
Intermediate/Slope
1000 m)
(100–
Shallow (<100 m)
Testing Phase
45 km
10 km
34 km
246 (253)
6m
1650 in3
Nine 2000 psi Bolt
Airguns of 40–360 in3
9-Airgun Array (1
Strings)
Deep Site (1500)
10 km
10 km
89 km
6m
40 in3
One 2000 psi Bolt
Airgun
1 Single Airgun
34 km
10 km
237 (243)
3m
210 in3
Two 105 in3 GI
Airguns
2 GI Guns
Intermediate/Slope Site
(475 m)
Shallow Site (30-60 m)
Calibration Phase
Proposed Approximate Airgun
Use
225.3 (230.7)
2.5 m
Towing Depth of Source
Source Output (dB re 1 miPa
m) 0-pk (pk-pk)*
45 in3
One 45 in3 GI Airgun
1 GI Gun
Air Discharge Volume (in3)
Energy Source
Airgun Specifications
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58 km
58 km
58 km
45 km
34 km
34 km
259 (265)
6 m or 12 m
6600 in3
Thirty-six 2000 psi Bolt
Airguns of 40–360 in3
36-Airgun Array (4
Strings)
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Safety Radii
L-DEO has estimated the safety radii
around their operations using a model,
but also by adjusting the model results
based on empirical data gathered in the
Gulf of Mexico in 2003. Additional
information regarding safety radii in
general, how the safety radii were
calculated, and how the empirical
measurements were used to correct the
modeled numbers may be found in
NMFS proposed IHA (71 FR 58790,
October 5, 2006) and Section I and
Appendix A of L-DEO’s application.
Using the modeled distances and
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various correction factors, Table 2
shows the distances at which three rms
sound levels (190 dB, 180 dB, and 160
dB) are expected to be received from the
various airgun configurations in
shallow, intermediate, and deep water
depths.
Predicted RMS Radii (m)
Source and Volume
Tow Depth (m)
Water Depth
190 DB
180 dB
160 dB
Single Gi gun
45 in3
3
Deep
Intermediate/Slope
Shallow
9
13.5
113
25
38
185
236
354
645
2 Gi guns
210 in3
3
Deep
Intermediate/Slope
Shallow
20
30
294
69
104
511
670
1005
1970
Single Bolt
40 in3
6
Deep
Intermediate/Slope
Shallow
12
18
150
36
54
267
360
540
983
1 string
9 airguns
1650 in3
6
Deep
Intermediate/Slope
Shallow
200
300
1450
650
975
2360
6200
7880
8590
2 string
18 airguns
3300 in3
6
Deep
Intermediate/Slope
Shallow
250
375
1820
820
1230
3190
6700
7370
8930
4 string
36 airguns
6600 in3
6
Deep
Intermediate/Slope
Shallow
410
615
2980
1320
1980
5130
8000
8800
10670
4 string
36 airguns
6600 in3
12
Deep
Intermediate/Slope
Shallow
620
930
4500
1980
2970
7700
12000
13200
16000
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Table 2. Modeled distances to which sound levels 190, 180, and 160 dB re 1 µPa (rms) might be received in shallow (<100 m), intermediate/
slope (100–1000 m), and deep (>1000 m) water from the various sources planned for use during the Gulf of Mexico study, fall 2007.
Comments and Responses
A notice of receipt of the L-DEO
application and proposed IHA was
published in the Federal Register on
October 5, 2006 (71 FR 58790). During
the comment period, NMFS received
comments from the Marine Mammal
Commission (MMC) and the Center for
Regulatory Effectiveness (CRE).
Following are the comments from the
MMC and CRE and NMFS’ responses:
Comment 1: The MMC recommends
that observations be made during all
ramp-up procedures to gather data
regarding the effectiveness of ramp-up
as a mitigation measure.
Response: The IHA requires that
MMOs on the Langseth make
observations for the 30 minutes prior to
ramp-up, during all ramp-ups, and
during all daytime seismic operations
and record the following information
when a marine mammal is sighted:
(i) Species, group size, age/size/sex
categories (if determinable), behavior
when first sighted and after initial
sighting, heading (if consistent), bearing
and distance from seismic vessel,
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sighting cue, apparent reaction to the
airguns or vessel (e.g., none, avoidance,
approach, paralleling, etc., and
including responses to ramp-up), and
behavioral pace;
(ii) Time, location, heading, speed,
activity of the vessel (including number
of airguns operating and whether in
state of ramp-up or power-down), sea
state, visibility, and sun glare.
These requirements should provide
information regarding the effectiveness
of ramp-up as a mitigation measure,
provided animals are detected during
ramp-up.
Comment 2: The MMC recommends
that the monitoring period prior to the
initiation of seismic activities be
extended to one hour.
Response: As the MMC points out,
several species of deep-diving cetaceans
are capable of remaining underwater for
more than 30 minutes, however, for the
following reasons NMFS believes that
30 minutes is an adequate length for the
monitoring period prior to the start-up
of airguns: (1) because the Langseth is
required to ramp-up, the time of
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monitoring prior to start-up of any but
the smallest array is effectively longer
than 30 minutes (Ramp up will begin
with the smallest gun in the array and
airguns will be added in a sequence
such that the source level of the array
will increase in steps not exceeding
approximately 6 dB per 5–min period
over a total duration of 20–30 min), (2)
in many cases MMOs are making
observations during times when sonar is
not being operated and will actually be
observing prior to the 30–minute
observation period anyway, (3), the
majority of the species that may be
exposed do not stay underwater more
than 30 minutes, and (4) all else being
equal and if a deep diving individual
happened to be in the area in the short
time immediately prior to the pre-startup monitoring, if an animal’s maximum
underwater time is 45 minutes, there is
only a 1 in 3 chance that his last random
surfacing would be prior to the
beginning of the required 30–minute
monitoring period.
Comment 3: The MMC recommends
that the Service provide additional
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justification for its proposed
determination that marine mammal
detection ability by trained observers is
close to 100 percent during daytime (in
good weather) and remains high at
night.
Response: The Langseth is utilizing a
team of trained MMOs to both visually
monitor from the high observation tower
of the Langseth and to conduct passive
acoustic monitoring.
When stationed on the observation
platform of the Langseth, the eye level
will be approximately 17.8 m (58.4 ft)
above sea level, so the visible distance
(in good weather) to the horizon is 8.9
nm (16.5 km) (the largest safety radii is
7.7 km (4.2 nm)). Big eyes are most
effective at scanning the horizon (for
blows), while 7 X 50 reticle binoculars
are more effective closer in (MMOs also
use a naked eye scan). Additionally,
MMOs will have a good view in all
directions around the entire vessel.
In some cases, particularly in shallow
water and while deploying streamers,
chase boats will be deployed. The
primary mission of the chase boat is to
warn boats that the seismic vessel is
approaching and thus the boat will be
in front of the seismic vessel (generally
about 2 nm). The plan is to have one
MMO on the chase boat, who will
advise the Langseth of the presence of
marine mammals in the operating area
when forward of the vessel and check
for injured animals when aft of the
vessel.
Theoretical detection distance of this
PAM system is 10s of kilometers. One
LGL biologist reported - ‘‘Past
experience in the GOM would indicate
good detection rates out to several
kilometers. It is not unreasonable to
state that the PAM will detect most
marine mammal calls within the 3 km
safety radius, particularly clicks from
sperm whales.’’ The PAM is operated
both during the day and at night.
Though it depends on the lights on
the ship, the sea state, and thermal
factors, MMOs estimated that visual
detection is effective out to between 150
and 250 m using NVDs and about 30 m
with the naked eye. However, the PAM
operates equally as effectively at night
as during the day, especially for sperm
whales and dolphins (dolphins are the
only species likely to be detected in the
‘‘shallow’’ depths, where the safety
zones are the largest).
Comment 4: The MMC recommends
that NMFS take steps to ensure that the
planned monitoring program will be
sufficient to detect, with reasonable
certainty, all marine mammals within or
entering identified safety zones.
Response: Based on the information
provided in the previous comment
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(above) and the following information,
NMFS believes that the planned
monitoring program will be sufficient to
detect (using visual detection and
PAM), with reasonable certainty, all
marine mammals within or entering
identified safety zones.
As mentioned above, the platform of
the Langseth is high enough that, in
good weather, MMOs can see out to 8.9
nm (16.5 km). The PAM has reliable
detection rates out to 3 km and more
limited ability out to 10s of km. The
largest 180–dB safety radii (3.2, 5.1, and
7.7 km), which is the radii within which
the Langseth is required to shut down
if a marine mammal enters, are found
when the 9–gun, 18–gun, and 36–gun
arrays are operating in shallow water.
The species most likely to be
encountered in the shallow water of the
GOM, by far, are bottlenose and Atlantic
spotted dolphins, which have relatively
larger group sizes (6–10 animals for
Atlantic spotted and 1–90 animals for
bottlenose), are not cryptic at the
surface, and have relatively short dive
times (< 2 minutes for Atlantic spotted
and 5–12 minutes for bottlenose), all
which generally make them easier to
visually detect. Additionally, the
vocalizations of these species are easily
detected by the PAM. Additionally, as
mentioned above, MMOs on chase boats
will sometimes be used in addition to
visual monitoring from the seismic
vessels and PAM. During the Maurice
Ewing cruise in the GOM in 2003,
MMOs detected marine mammals at a
distance of approximately 10 km from
the vessel and identified them to species
at approximately 5 km from the vessel,
though the bridge of that vessel was
only 11 m above the water (vs. the
Langseth, which is 17 m above). All of
the 180–dB safety radii for other depths
are less than 3 km (all less than 2 km,
except the 36–gun array at intermediate
depth, which is 2.97 km).
The likelihood of visual detection at
night is significantly lower than during
the day, though the PAM remains just
as effective at night as during the day.
However, the Langseth will not be
starting up the airguns unless the safety
range is visible for the entire 30 minutes
prior (i.e., not an night), and therefore
in all cases at night, the airguns will
already be operating, which NMFS
believes will cause many cetaceans to
avoid the vessel, which therefore will
reduce the number likely to come
within the safety radii. Additionally,
because of normal operating procedures,
which entail beginning seismic
operations as soon after dawn as
possible, at the most 33% of the actual
airgun operation (and much less, most
likely) will occur at nighttime. With the
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exception of operation of airguns in
shallow water (which between the 9-,
18-, and 36–gun array totals about 18
hours), all of the other safety radii are
smaller than 3 km and fall easily within
the reliable detection capabilities of the
PAM.
Comment 5: The CRE believes that
NMFS should grant the Lamont-Doherty
Earth Observatory an IHA for L-DEO’s
proposed seismic experiments in the
GOM. However, the CRE recommended
that NMFS revise the IHA to state:
(1) There is no evidence that Gulf
seismic operations complying with the
traditional 500 meter safety radii have
injured marine mammals or any other
marine life.
(2) The much larger safety radii in the
proposed IHA are based on flawed
models and unreliable data.
(3) Visual observation and PAM
cannot accurately and reliably monitor
for marine mammals in safety radii
significantly larger than the traditional
500 meters.
Response:
(1) Neither the proposed IHA nor this
Federal Register notice state that Gulf
seismic operations, utilizing any size
safety zone, have injured marine
mammals. The proposed IHA states that
there is ‘‘no specific evidence that
exposure to pulses of airgun sound can
cause PTS in any marine mammal’’ and
that ‘‘Airgun pulses are less energetic
and have slower rise times [than
explosives], and there is no proof that
they can cause serious injury, death, or
stranding even in the case of large
airgun arrays’’.
(2) As CRE points out in their letter,
L-DEO acknowledges in their
application the shortcomings of the
2003 data collection using airguns in the
GOM, however, this is the best available
data for seismic sound propagation in
the GOM and L-DEO further explains
(see proposed IHA) how they use
conservative correction factors in the
development of appropriate safety radii
(based on the 180–dB criteria prescribed
by NMFS). The purpose of the current
L-DEO seismic calibration is to improve
these data for use in future operations
and MMPA authorizations.
(3) NMFS believes that between visual
monitoring and PAM the MMOs can
accurately and reliably detect marine
mammals within safety radii
significantly larger than 500 m (see
NMFS’ responses to comments 3 and 4).
Description of Marine Mammals in the
Activity Area
In the Gulf of Mexico, 28 cetacean
species and one species of manatee are
known to occur (Jefferson and Schiro,
1997; Wursig et al., 2000). In the U.S.,
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manatees are managed by the U.S. Fish
& Wildlife Service (USFWS), are
unlikely to be encountered in or near
the open waters of the Gulf of Mexico
where seismic operations will occur,
and are, therefore, not addressed further
in this document. Most of these species
of cetaceans occur in oceanic waters
(>200 m or 656 ft deep) of the Gulf,
whereas the continental shelf waters
(<200 m) are primarily inhabited by
bottlenose dolphins and Atlantic
spotted dolphins (Mullin and Fulling
2004).
Seven species that may occur in the
Gulf of Mexico are listed as endangered
under provisions of the U.S. Endangered
Species Act (ESA), including the sperm,
North Atlantic right, humpback, sei, fin,
and blue whale, as well as the West
Indian manatee. However, of those
species, only sperm whales are likely to
be encountered. In addition to the 28
species known to occur in the Gulf of
Mexico, another three species of
cetaceans could potentially occur there:
the long-finned pilot whale, the longbeaked common dolphin, and the shortbeaked common dolphin (Table 3).
Though any pinnipeds sighted in the
study area would be extralimital,
hooded seals have been reported in
Florida and L-DEO has requested
authorization for the take of 2 animals.
During the 2003 acoustical calibration
study in the Gulf of Mexico from 28
May to 2 June, a total of seven visual
sightings of marine mammals were
documented from the Maurice Ewing;
these included a total of approximately
38–40 individuals (LGL Ltd. 2003). In
addition, three sea turtles were sighted.
These totals include times when airguns
were not operating as well as times
BEST
MAXIMUM
Habitat
Occurrence
in GOM
Abundance in
GOM and/or North
Atlantic
Estimated
Exposures
Approx. % of
Population
Ext. Exposures Auth
IHA**
Approx.C%
of Population
Usually pelagic and
deep seas
Common
1349 / 13190 (add)
22
0.2
22
0.2
Pygmy sperm whale
Deeper waters off
the shelf
Common
742 / 695 (add)
56
3.9
59
4.1
Dwarf sperm whale
Deeper waters off
the shelf
Common
742 / 695 (add)
56
3.9
59
4.1
Cuvier’s beaked whale
Pelagic
Rare
159 / 3196 (add)
10
0.3
21
0.7
Sowerby’s beaked
whale
Pelagic
Extralimital
106 / 541 (add)
5
0.8
8
1.2
Gervais’ beaked whale
Pelagic
Uncommon
106 / 541 (add)
5
0.8
8
1.2
Blainville’s beaked
whale
Pelagic
Rare
106 / 541 (add)
5
0.8
8
1.2
Mostly pelagic
Common
2223 / 274 (add)
58
2.3
92
3.7
Bottlenose dolphin
Cont. shelf, coastal
and offshore
Common
25,320 / 2239 /
29774 (add)
773
1.3
1713
5.0
Pantropical spotted
dolphin
Mainly pelagic
Common
91,321 / 13117
(add)
1282
1.2
1587
1.5
Atlantic spotted dolphin
Mainly coastal waters
Common
30,947 / 52279
(add)
876
1.1
1755
0.2
Spinner dolphin
Pelagic in Gulf of
Mexico
Common
11,971
168
1.4
921
7.7
Clymene dolphin
Pelagic
Common
17,355 / 6086
(add)
244
1.0
311
1.3
Striped dolphin
Off the continental
shelf
Common
6505 / 61546 (add)
91
0.1
134
0.2
Short-beaked common
dolphin
Continental shelf
and pelagic waters
Possible
30,768
0
0.0
0 (5)**
<0.1
Long-beaked common
dolphin
Coastal
Possible
N.A.
0
0.0
0 (5)**
0.0
Fraser’s dolphin
Water >1000m
Common
726
10
1.4
60
8.3
Risso’s dolphin
Waters 400-1000m
Common
2169 / 29110 (add)
54
0.2
81
0.3
Oceanic
Common
3451
49
1.4
142
4.1
E:\FR\FM\15AUN1.SGM
15AUN1
Species
Odontocetes
Sperm whale
ebenthall on PROD1PC69 with NOTICES
Rough-toothed dolphin
Melon-headed whale
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Federal Register / Vol. 72, No. 157 / Wednesday, August 15, 2007 / Notices
BEST
MAXIMUM
Habitat
Occurrence
in GOM
Abundance in
GOM and/or North
Atlantic
Estimated
Exposures
Approx. % of
Population
Ext. Exposures Auth
IHA**
Approx.C%
of Population
Pygmy killer whale
Oceanic
Uncommon
408
10
2.6
21
5.1
False killer whale
Pelagic
Uncommon
1038
14
1.4
28
2.7
Widely distributed
Uncommon
133 / 6600 (add)
3
<0.1
5
0.1
Short-finned pilot
whale
Mostly pelagic
Common
2388 / 780000 /
14524
34
<0.1
98
<0.1
Long-finned pilot whale
Mostly pelagic
Possible
N.A.
0
0 (5)**
North Atlantic right
whale*
Coastal and shelf
waters
Extralimital
291
0
0
Humpback whale*
Mainly near-shore
waters / banks
Rare
11,570 / 10400
0
0
Minke whale
Coastal waters
Rare
149,000
0
0
Bryde’s whale
Pelagic and coastal
Uncommon
40 / 90000
1
Sei whale*
Primarily offshore,
pelagic
Rare
12-13,000
0
0
Fin whale*
Cont. slope, mostly
pelagic
Rare
2814 / 47300
0
0
Blue whale*
Coastal, shelf, and
oceanic waters
Extralimital
308
0
0
Coastal
Vagrant
400,000z
0
0 (2)**
3770
7096
Species
Killer whale
Mysticetes
2.5
2
5.0
Pinnipeds
Hood seal
Total
<0.1
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Table 3. Abundance, preferred hatitat, and commonness of the marine mammals species found in the survey area. The far right columns indicate the estimated number of each species that will be exposed to 160 dB based on best and maximum density estimates. NMFS believes that,
when mitigation measures are taken into consideration, the activity is likely to result in take of numbers of animals less than those indicated by
the best column, however, NMFS has authorized the number in this column.
* Federally listed endangered
** Parenthetical number indicates take authorization, though exposure estimate is 0
when airguns were firing. Visual
monitoring effort consisted of 60.9
hours of observations (all in daylight)
along 891.5 km of vessel trackline on
seven days, and passive acoustic
monitoring (PAM) occurred for
approximately 32 hours. Most of the
monitoring effort (visual as well as
acoustic) occurred when airguns were
not operating, since airgun operations
were limited during the 2003 study. No
marine mammals were detected during
acoustic monitoring. Marine mammal
and sea turtle sightings and locations
during the 2003 calibration study are
summarized in Appendix C of L-DEOs
application.
Additional information regarding the
status and distribution of the marine
mammals in the area and how the
densities were calculated was included
in the notice of the proposed IHA (71 FR
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58790) and may be found in L-DEO’s
application.
Potential Effects of the Activity on
Marine Mammals
The effects of sounds from airguns
might include one or more of the
following: tolerance, masking of natural
sounds, behavioral disturbance,
temporary or permanent hearing
impairment (Richardson et al., 1995), or
other non-auditory physiological effects
such as stress, neurological effects,
bubble formation, resonance effects, and
other types of organ or tissue damage.
To avoid injury, NMFS has determined
that cetaceans and pinnipeds should not
be exposed to pulsed underwater noise
at received levels exceeding,
respectively, 180 and 190 dB re 1 µPa
(rms). The predicted 180- and 190–dB
distances for the GI guns operated by
SIO are summarized in Table 2. Given
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the required mitigation and monitoring
measures, it is unlikely that there would
be any cases of temporary or, especially,
permanent hearing impairment or other
serious non-auditory physiological
effects.
The notice of the proposed IHA (71
FR 58790, October 5, 2006) included a
discussion of the effects of sounds from
airguns on mysticetes, odontocetes, and
pinnipeds, including tolerance,
masking, behavioral disturbance,
hearing impairment and other nonauditory physical effects. Additional
details on the behavioral reactions (or
the lack thereof) by all types of marine
mammals to seismic vessels can be
found in Appendix A (e) of L-DEO’s
application.
The notice of the proposed IHA also
included a discussion of the potential
effects of the bathymetric sonar. Because
of the shape of the beam of this source
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and its power, NMFS believes it
unlikely that marine mammals will be
exposed to bathymetric sonar at levels at
or above those likely to cause
harassment. Further, NMFS believes
that the brief exposure of cetaceans or
pinnipeds to small numbers of signals
from the multi-beam bathymetric sonar
system are not likely to result in the
harassment of marine mammals.
Monitoring and Mitigation Measures
Monitoring
L-DEO will conduct mammal
monitoring of its seismic program, in
order to implement the planned
mitigation measures and to satisfy the
requirements of the IHA. More
information regarding the Monitoring
program (including both visual
observation and passive acoustic
detection) was included in NMFS’
proposed IHA (71 FR 58790, October 5,
2006).
ebenthall on PROD1PC69 with NOTICES
Vessel Based Monitoring
Vessel-based marine mammal
observers (MMOs) will watch for marine
mammals near the seismic source vessel
during all daytime airgun operations
and during any start ups of the airguns
at night. When feasible, observations
will also be made during daytime
periods without seismic operations (e.g.,
during transits).
During seismic operations in the Gulf
of Mexico, five observers will be based
aboard the vessel. MMOs will be
appointed by L-DEO with NMFS
concurrence. At least one MMO, and
when practical two MMOs, will watch
for marine mammals near the seismic
vessel during ongoing daytime
operations and nighttime start ups of the
airguns. MMO(s) will be on duty in
shifts of duration no longer than 4 h.
The crew will also be instructed to
assist in detecting marine mammals and
implementing mitigation requirements
(if practicable). Before the start of the
seismic survey the crew will be given
additional instruction in how to do so.
The Langseth is a suitable platform for
marine mammal observations. When
stationed on the observation platform,
the eye level will be approximately 17.8
m (58.4 ft) above sea level, and the
observer will have a good view around
the entire vessel. However, neither the
actual bow of the vessel nor the stern
will be visible from the observation
platform, although it will be possible to
see the airguns. To monitor the areas
immediately at the bow and stern of the
vessel, two video cameras will be
installed at the bow (one on the
starboard and one on the port side), and
a wide-angle camera will be installed at
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the stern. Real-time footage from these
cameras will be played on the
observation platform, so that the
MMO(s) are able to monitor those areas.
In addition a high-power video camera
will be mounted on the observation
platform to assist with species
identification.
During daytime, the MMO(s) will scan
the area around the vessel
systematically with reticle binoculars
(e.g., 7 50 Fujinon), Big-eye binoculars
(25 150), and with the naked eye. At
night, Night Vision Devices (NVDs) will
be available (ITT F500 Series Generation
3 binocular-image intensifier or
equivalent), when required. Laser
rangefinding binoculars (Leica LRF 1200
laser rangefinder or equivalent) will be
available to assist with distance
estimation. Those are useful in training
observers to estimate distances visually,
but are generally not useful in
measuring distances to animals directly.
MMOs will not be on duty during
ongoing seismic operations at night. At
night, bridge personnel will watch for
marine mammals. If the airguns are
started up at night, two MMOs will
watch for marine mammals near the
source vessel for 30 min prior to start up
of the airguns using NVDs, if the proper
conditions for nighttime start up exist
(see Mitigation below).
The vessel-based monitoring will
provide data to estimate the numbers of
marine mammals exposed to various
received sound levels, to document any
apparent disturbance reactions or lack
thereof, and thus to estimate the
numbers of mammals potentially
‘‘taken’’ by harassment. It will also
provide the information needed in order
to power down or shut down the
airguns at times when mammals are
present in or near the safety radii. When
a sighting is made, the following
information about the sighting will be
recorded:
1. Species, group size, age/size/sex
categories (if determinable), behavior
when first sighted and after initial
sighting, heading (if consistent), bearing
and distance from seismic vessel,
sighting cue, apparent reaction to the
airguns or vessel (e.g., none, avoidance,
approach, paralleling, etc.), and
behavioral pace.
2. Time, location, heading, speed,
activity of the vessel, sea state,
visibility, and sun glare.
The data listed under (2) will also be
recorded at the start and end of each
observation watch, and during a watch
whenever there is a change in one or
more of the variables.
All observations and power-downs or
shut downs (see Mitigation below) will
be recorded in a standardized format.
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Data will be entered into a custom
database using a notebook computer.
The accuracy of the data entry will be
verified by computerized validity data
checks as the data are entered and by
subsequent manual checking of the
database. These procedures will allow
initial summaries of data to be prepared
during and shortly after the field
program, and will facilitate transfer of
the data to statistical, graphical, or other
programs for further processing and
archiving.
Passive Acoustic Monitoring
Passive acoustic monitoring will take
place to complement the visual
monitoring program. Visual monitoring
typically is less effective during periods
of bad weather or at night, and even
with good visibility, is unable to detect
marine mammals when they are below
the surface or beyond visual range.
Acoustical monitoring can be used in
addition to visual observations to
improve detection, identification,
localization, and tracking of cetaceans.
The acoustic monitoring will serve to
alert visual observers when vocalizing
cetaceans are detected. It will be
monitored in real time so that the visual
observers can be advised when
cetaceans are detected.
SEAMAP (Houston, TX) will be used
as the primary acoustic monitoring
system. This system was also used
during previous L-DEO seismic cruises
(e.g., Smultea et al., 2004, 2005; Holst et
al., 2004a,b). The PAM system consists
of hardware (i.e., the hydrophone) and
software. The ‘‘wet end’’ of the
SEAMAP system consists of a lownoise, towed hydrophone array that is
connected to the vessel by a ‘‘hairy’’
faired cable. The array will be deployed
from a winch located on the back deck.
A deck cable will connect from the
winch to the main computer lab where
the acoustic station and signal
conditioning and processing system will
be located. The lead-in from the
hydrophone array is approximately 400
m (1312 ft) long, and the active part of
the hydrophone array is approximately
56 m (184 ft) long. The hydrophone
array is typically towed at depths of less
than 20 m or 66 ft.
The acoustical array will be
monitored 24 hours per day while at the
seismic survey area during airgun
operations and during most periods
when airguns are not operating. One
MMO will monitor the acoustic
detection system at any one time, by
listening to the signals from two
channels via headphones and/or
speakers and watching the real-time
spectrographic display for frequency
ranges produced by cetaceans. MMOs
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monitoring the acoustical data will be
on shift from 1–6 h. All MMOs are
expected to rotate through the PAM
position, although the most experienced
with acoustics will be on PAM duty
more frequently.
When a vocalization is detected, the
acoustic MMO will contact the visual
MMO immediately (so a power-down or
shut down can be initiated, if required),
and the information regarding the call
will be entered into a database. The data
to be entered include an acoustic
encounter identification number,
whether it was linked with a visual
sighting, GMT date, GMT time when
first and last heard and whenever any
additional information was recorded,
GPS position and water depth when
first detected, species or species group
(e.g., unidentified dolphin, sperm
whale), types and nature of sounds
heard (e.g., clicks, continuous, sporadic,
whistles, creaks, burst pulses, strength
of signal, etc.), and any other notable
information. The acoustic detection can
also be recorded onto the hard-drive for
further analysis.
ebenthall on PROD1PC69 with NOTICES
Mitigation
L-DEO’s study in the northern Gulf of
Mexico will deploy an energy source of
up to 36 airguns (6600 in3). The airguns
comprising the array will be spread out
horizontally, so that the energy will be
directed mostly downward. This
directionality will result in reduced
sound levels at any given horizontal
distance than would be expected at that
distance if the source were
omnidirectional with the stated nominal
source level.
Localized and temporally-variable
areas of concentrated feeding or of
special significance for marine
mammals may occur within or near the
planned area of operations during the
season of operations. However, L-DEO
will avoid conducting the activities near
important concentrations of marine
mammals insofar as these can be
identified in advance from other sources
of information, or during the cruise.
Safety Radii
As noted earlier (Table 2), received
sound levels were modeled by L-DEO
for various configurations of the 36airgun array in relation to distance and
direction from the airguns, and for a
single and 2 GI guns. Correction factors
based on empirical measurements were
applied to estimate safety radii in
shallow and intermediate-depth water.
The distances from the airguns where
sound levels of 190, 180, and 160 dB re
1 µPa (rms) are estimated to be received
are shown Table 2. Also, the safety radii
for a single (40 in3) airgun are given, as
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that source will be in operation when
the 36-airgun array is powered down.
Airguns will be powered down (or shut
down if necessary) immediately when
marine mammals are detected within or
about to enter the appropriate radius:
180 dB (rms) for cetaceans, and 190 dB
(rms) for pinnipeds, in the very unlikely
event that pinnipeds are encountered.
Mitigation During Operations
Mitigation measures that will be
required will include (1) speed or
course alteration, provided that doing so
will not compromise operational safety
requirements, (2) power-down
procedures, (3) shut-down procedures,
(4) special shut-down procedures for
baleen whales at any distance, (5) rampup procedures, (6) avoidance of
submarine canyons and areas with
known concentrations of marine
mammals, if possible, and (7) shut down
and notification of NMFS if an injured
or dead marine mammal is found and is
judged likely to have resulted from the
operation of the airguns.
Speed or Course Alteration—If a
marine mammal or is detected outside
the safety radius and, based on its
position and the relative motion, is
likely to enter the safety radius, the
vessel’s speed and/or direct course may
be changed. This would be done if
practicable while minimizing the effect
to the planned science objectives. The
activities and movements of the marine
mammal or sea turtle (relative to the
seismic vessel) will be closely
monitored to determine whether the
animal is approaching the applicable
safety radius. If the animal appears
likely to enter the safety radius, further
mitigative actions will be taken, i.e.,
either further course alterations or a
power-down or shut down of the
airguns.
Power-down Procedures—A powerdown involves decreasing the number of
airguns in use such that the radius of
the 18-dB (or 190-dB) zone is decreased
to the extent that marine mammals are
no longer in or about to enter the safety
zone. A power-down may also occur
when the vessel is moving from one
seismic line to another (ie., during a
turn). During a power-down, one airgun
will be operated. The continued
operation of one airgun is intended to
alert marine mammals to the presence of
the seismic vessel in the area. In
contrast, a shut down occurs when all
airgun activity is suspended.
If a marine mammal is detected
outside the safety zone but is likely to
enter the safety radius, and if the
vessel’s speed and/or course cannot be
changed to avoid having the animal
enter the safety radius, the airguns will
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be powered down before the animal is
within the safety radius. Likewise, if a
mammal or turtle is already within the
safety zone when first detected, the
airguns will be powered down
immediately. During a power-down of
the airgun array, at least one airgun (e.g.,
40 in3) will be operated. If a marine
mammal is detected within or near the
smaller safety radius around that single
airgun (Table 2), all airguns will be shut
down (see next subsection).
Following a power-down, airgun
activity 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: (1) is
visually observed to have left the safety
zone; or, (2) has not been seen within
the zone for 15 min in the case of small
odontocetes and pinnipeds; or, (3) has
not been seen within the zone for 30
min in the case of mysticetes and large
odontocetes, including sperm, pygmy
sperm, dwarf sperm, and beaked
whales.
During airgun operations following a
power-down whose duration has
exceeded specified limits, the airgun
array will be ramped up gradually.
Ramp-up procedures are described
below.
Shut-down Procedures—During a
power-down, the operating airgun will
be shut down if a marine mammal
approaches within the modeled safety
radius for the then-operating source,
typically a single 40 in3 gun or a GI gun
(Table 2). If a marine mammal is
detected within or about to enter the
appropriate safety radius around the
small source in use during a powerdown, airgun operations will be entirely
shut down.
Airgun activity will not resume until
the animal has cleared the safety zone,
or until the MMO is confident that the
marine mammal has left the vicinity of
the vessel. Criteria for judging that the
animal has cleared the safety zone will
be as described in the preceding
subsection.
Special Shut-down Provision for
Mysticetes—The airguns will be shut
down (not just powered down) if a
mysticete is sighted anywhere near the
vessel, even if the whale is located
outside the safety radius. This measure
is planned because of the assumed
greater effects of seismic surveys on
mysticetes in general (as compared with
other marine mammals).
Ramp-up Procedures – A ramp-up
procedure will be followed when the
airgun array begins operating after a
specified-duration without airgun
operations. For the present cruise, this
period would be approximately 10 min.
This duration is based on provisions
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during previous L-DEO surveys and on
the approximately 180–dB radius for the
4–string array in deep water in relation
to the planned speed of the Langseth
while shooting. Ramp up will begin
with the smallest gun in the array.
Airguns will be added in a sequence
such that the source level of the array
will increase in steps not exceeding
approximately 6 dB per 5–min period
over a total duration of 20–30 min.
During ramp up, the safety zone for the
full airgun array to be used will be
maintained.
If the complete safety radius has not
been visible for at least 30 min prior to
the start of operations in either daylight
or nighttime, ramp up will not
commence unless at least one airgun has
been operating during the interruption
of seismic survey operations. That
airgun will have a source level of more
than 180 dB re 1 µPa . m (rms). It is
likely that the airgun array will not be
ramped up from a complete shut down
at night or in thick fog (the array will
definitely not be ramped up from a
complete shut down at night in shallow
water), because the outer part of the
safety zone for the array will not be
visible during those conditions. If one
airgun has operated during a powerdown period, ramp up to full power will
be permissible at night or in poor
visibility, on the assumption that
marine mammals will be alerted to the
approaching seismic vessel by the
sounds from the single airgun and could
move away if they choose. Ramp up of
the airguns will not be initiated if a
marine mammal is sighted within or
near the applicable safety radii during
the day or close to the vessel at night.
Avoidance of Areas with
Concentrations of Marine Mammals –
Beaked whales may be highly sensitive
to sounds produced by airguns, based
mainly on what is known about their
responses to other sound sources.
Beaked whales tend to concentrate in
continental slope areas, and especially
in areas where there are submarine
canyons on the slope. Therefore, L DEO
will, if possible, avoid airgun operations
over or near submarine canyons within
the present study area. Also, if
concentrations of beaked whales are
observed at the slope site just prior to
or during the airgun operations there,
those operations will be moved to
another location along the slope based
on recommendations by the lead MMO
aboard the Langseth. Furthermore, any
areas where concentrations of sperm
whales are known to be present will be
avoided if possible.
Shutdown if Injured or Dead Whale is
Found – In the unanticipated event that
any cases of marine mammal injury or
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mortality are found and are judged
likely to have resulted from these
activities, L-DEO will cease operating
seismic airguns and report the incident
to the Office of Protected Resources,
NMFS immediately.
Reporting
L-DEO will provide brief field reports
on the progress of the project on a
weekly basis.
A report will be submitted to NMFS
within 90 days after the end of the
cruise. The report will describe the
operations that were conducted and the
marine mammals and turtles that were
detected near the operations. The report
will be submitted to NMFS, providing
full documentation of methods, results,
and interpretation pertaining to all
monitoring. The 90–day report will
summarize the dates and locations of
seismic operations, and all marine
mammal and turtle sightings (dates,
times, locations, activities, associated
seismic survey activities). The report
will also include estimates of the
amount and nature of potential ‘‘take’’
of marine mammals by harassment or in
other ways.
Estimated Take by Incidental
Harassment
The notice of the proposed IHA (71
FR 58790, October 5, 2006) included an
in-depth discussion of the methods used
to calculate the densities of marine
mammals in the area of the seismic
airgun operation and the take estimates.
Additional information was included in
section VII of L-DEO’s application. A
summary of the total take authorized by
NMFS is included here in Table 3.
Generally, estimates of the numbers of
marine mammals that might be affected
during the seismic program in the
northern Gulf of Mexico are based on
consideration of the number of marine
mammals that might be exposed to 160
dB along the 1420 km (767 nm)
trackline of seismic surveys during the
Gulf of Mexico program. The numbers
of animals estimated below do not take
into consideration the implementation
of mitigation measures and, therefore,
probably overestimate the take to some
degree.
Because of the mitigation measures
that will be required and the likelihood
that some cetaceans will avoid the area
around the operating airguns of their
own accord, NMFS does not expect any
marine mammals to approach the sound
source close enough to be injured (Level
A harassment). All anticipated takes
would be ‘‘takes by Level B
harassment’’, as described previously,
involving temporary behavioral
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45753
modifications or low level physiological
effects.
The ‘‘best estimate’’ of the number of
individual marine mammals that might
be exposed, absent any mitigation
measures, to seismic sounds with
received levels 160 dB re 1 µPa (rms) is
3770 (Table 3). That total includes 22
endangered sperm whales, 25 beaked
whales, and one Bryde’s whale (Table
3). Pantropical spotted dolphins,
Atlantic spotted dolphins, and
bottlenose dolphins are expected to be
the most common species in the study
area; the best estimates for those
species, absent any mitigation, are 1282,
876, and 773, respectively (Table 3).
Estimates for other species are lower.
The ‘‘Maximum Estimate’’ column in
Table 3 shows estimates totaling 7082
individual marine mammals based on
maximum densities, and taking into
account an adjustment for small
numbers of other species that might be
encountered in the survey area, even
though there were not recorded during
previous surveys. These are the
numbers for which ‘‘take authorization’’
is requested. NMFS does not expect the
total number of marine mammal takes to
be this high, however, it is appropriate
to err on the cautious side to ensure that
L-DEO is covered in the event that an
unexpectedly large number of any
particular species were exposed to ≤160
dB during the survey and, further, to
ensure that this exposure would result
in a negligible impact to the species or
stock.
Based on numbers of animals
encountered during L-DEO’s 2003 cruise
in the Gulf of Mexico, the likelihood of
the successful implementation of the
required mitigation measure, and the
likelihood that some animals will avoid
the area around the operating airguns,
NMFS believes that L-DEOs airgun
calibration and seismic testing program
may result in the Level B harassment of
some lower number of individual
marine mammals than is indicated by
the ‘‘best estimates’’ in Table 3. These
best estimates compose no more than
3.9 percent of any given species
population in the northern Gulf of
Mexico, and NMFS has determined that
these numbers are small relative to the
population sizes in the specified
geographic area (Table 3). L-DEO has
asked for authorization for take of their
‘‘maximum estimate’’ of numbers for
each species, which includes the take of
two hooded seals. Though NMFS
believes that take of the maximum
numbers is unlikely, we still find these
numbers small (up to 8.3 percent of the
Fraser’s dolphin population and 7.7
percent of the spinner dolphin
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population, but less than 5 percent the
others) relative to the population sizes.
ebenthall on PROD1PC69 with NOTICES
Potential Effects on Habitat
A detailed discussion of the potential
effects of this action on the marine
mammal habitat, including
physiological and behavioral effects on
marine fish and invertebrates, was
included in the notice of the proposed
IHA (71 FR 58790, October 5, 2007).
The main impact issue associated
with the activity will be temporarily
elevated noise levels and the associated
direct effects on marine mammals.
Based on the discussion in the proposed
IHA, the authorized operations are not
expected to have any habitat-related
effects that could cause significant or
long-term consequences for individual
marine mammals or their populations or
stocks.
Negligible Impact Determination
NMFS has determined, provided that
the aforementioned mitigation and
monitoring measures are implemented,
that the impact of conducting an
acoustic calibration and seismic testing
program in the Gulf of Mexico may
result, at worst, in a temporary
modification in behavior and/or lowlevel physiological effects (Level B
Harassment) of small numbers of certain
species of marine mammals. While
behavioral and avoidance reactions may
be made by these species in response to
the resultant noise from the airguns,
these behavioral changes are expected to
have a negligible impact on the affected
species and stocks of marine mammals.
While the number of potential
incidental harassment takes will depend
on the distribution and abundance of
marine mammals in the area of seismic
operations, the number of potential
harassment takings is estimated to be
relatively small in light of the
population size (see Table 3). NMFS
anticipates the actual take of individuals
to be lower than the numbers depicted
in the table, because those numbers do
not reflect either the implementation of
the mitigation measures or the fact that
some animals will avoid the sound at
levels lower than those expected to
result in harassment. Additionally,
mitigation measures require that the
Langseth avoid any areas where marine
mammals are concentrated.
In addition, no take by death and/or
serious injury is anticipated, and the
potential for temporary or permanent
hearing impairment will be avoided
through the incorporation of the
required mitigation measures described
in this document. This determination is
supported by (1) the likelihood that,
given sufficient notice through slow
VerDate Aug<31>2005
15:00 Aug 14, 2007
Jkt 211001
ship speed and ramp-up of the seismic
array, marine mammals are expected to
move away from a noise source that it
is annoying prior to its becoming
potentially injurious; (2) TTS is unlikely
to occur, especially in odontocetes, until
levels above 180 dB re 1 µPa are
reached; (3) the fact that injurious levels
of sound are only likely close to the
vessel; and (4) the likelihood of
detection of marine mammals within
the safety radii developed to avoid
injury is high due to the height of the
Langseth’s bridge and the use of a
passive acoustic detection system.
Endangered Species Act
Pursuant to section 7 of the ESA, the
National Science Foundation (NSF) has
consulted with NMFS on this seismic
survey. NMFS has also consulted
internally pursuant to Section 7 of the
ESA on the issuance of an IHA under
section 101(a)(5)(D) of the MMPA for
this activity. In a Biological Opinion
(BO), NMFS concluded that the 2007 LDEO seismic survey in the northern
GOM and the issuance of the associated
IHA are not likely to jeopardize the
continued existence of threatened or
endangered species or destroy or
adversely modify any designated critical
habitat. NMFS has issued an incidental
take statement (ITS) for 22 sperm
whales (as well as a number of
individuals of green, hawksbill, Kemp’s
ridley, leatherback, and loggerhead sea
turtles) that contains reasonable and
prudent measures with implementing
terms and conditions to minimize the
effects of this take. The terms and
conditions of the Biological Opinion
that apply to listed marine mammals
have been incorporated into the IHA.
National Environmental Policy Act
(NEPA)
In 2003, NSF prepared an
Environmental Assessment (EA) for a
marine seismic survey by the R/V
Maurice Ewing in the Northern Gulf of
Mexico. This EA addressed the potential
effects of a different combination of
airgun arrays (20 airguns, total volume
8580 in3) being operated in the same
part of the ocean and affecting the same
populations of marine mammals as is
proposed for the Langseth in this
application. NMFS adopted NSF’s EA in
2003 and prepared a supplemental EA
in 2007 to clarify the differences
between the two activities and their
potential effects on the environment.
NMFS has issued a Finding of
Significant based on NSF’s 2003 EA and
NMFS supplemental EA.
PO 00000
Frm 00032
Fmt 4703
Sfmt 4703
Conclusions
Based on the preceding information,
and provided that the required
mitigation and monitoring are
incorporated, NMFS has concluded that
the activity will incidentally take, by
Level B harassment only, small numbers
of marine mammals. NMFS has further
determined that L-DEO’s calibration
study will have a negligible impact on
the affected species or stocks of marine
mammals and will not have an
unmitigable adverse impact on the
availability of the affected species or
stocks for subsistence uses.
Authorization
NMFS has issued an IHA to L-DEO for
an acoustic calibration and seismic
testing program in the northern Gulf of
Mexico in Fall, provided the previously
mentioned mitigation, monitoring, and
reporting requirements are incorporated.
Dated: July 27, 2007.
James H. Lecky,
Director, Office of Protected Resources,
National Marine Fisheries Service.
[FR Doc. E7–16013 Filed 8–14–07; 8:45 am]
BILLING CODE 3510–22–S
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric
Administration
Notice of Public Meeting
SUMMARY: The Advisory Committee on
Commercial Remote Sensing (ACCRES)
will meet September 20, 2007.
Date and Time: The meeting is
scheduled as follows: September 20,
2007, 9 a.m.–4 p.m. The first part of this
meeting will be closed to the public.
The public portion of the meeting will
begin at 1:30 p.m.
The meeting will be held in
the Auditorium of the National
Association of Home Builders Building,
Washington, DC, located at 1201 15th
Street, NW., Washington, DC 20005.
While open to the public, seating
capacity may be limited.
ADDRESSES:
As
required by section 10(a)(2) of the
Federal Advisory Committee Act, 5
U.S.C. App. (1982), notice is hereby
given of the meeting of ACCRES.
ACCRES was established by the
Secretary of Commerce (Secretary) on
May 21, 2002, to advise the Secretary
through the Under Secretary of
Commerce for Oceans and Atmosphere
on long- and short-range strategies for
the licensing of commercial remote
sensing satellite systems.
SUPPLEMENTARY INFORMATION:
E:\FR\FM\15AUN1.SGM
15AUN1
]]>Agencies
[Federal Register Volume 72, Number 157 (Wednesday, August 15, 2007)]
[Notices]
[Pages 45744-45754]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E7-16013]
-----------------------------------------------------------------------
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[I.D. 050107H]
Incidental Takes of Marine Mammals During Specified Activities;
Seismic Testing and Calibration in the Northern Gulf of Mexico
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of incidental harassment authorization.
-----------------------------------------------------------------------
SUMMARY: In accordance with the Marine Mammal Protection Act (MMPA)
regulations, notification is hereby given that NMFS has issued an
Incidental Harassment Authorization (IHA) to the Lamont-Doherty Earth
Observatory (L-DEO) to take small numbers of marine mammals, by Level B
Harassment only, incidental to conducting an acoustic calibration and
seismic testing program in the northern Gulf of Mexico.
DATES: Effective from July 31, 2007 through July 30, 2008.
ADDRESSES: A copy of the IHA, the application, and the associated
Environmental Assessment (EA) and Supplemental EA are available by
writing to Michael Payne, Chief, Permits, Conservation, and Education
Division, Office of Protected Resources, National Marine Fisheries
Service, 1315 East-West Highway, Silver Spring, MD 20910-3225, or by
telephoning the contact listed here. A copy of the application
containing a list of references used in this document may be obtained
by writing to this address, by telephoning the contact listed here (FOR
FURTHER INFORMATION CONTACT) or online at: https://www.nmfs.noaa.gov/pr/
permits/incidental.htm. Documents cited in this notice may be viewed,
by appointment, during regular business hours, at the aforementioned
address.
FOR FURTHER INFORMATION CONTACT: Jolie Harrison, Office of Protected
Resources, NMFS, (301) 713-2289, ext 166.
SUPPLEMENTARY INFORMATION:
Background
Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)
direct the Secretary of Commerce to allow, upon request, the
incidental, but not intentional, taking of marine mammals by U.S.
citizens who engage in a specified activity (other than commercial
fishing) within a specified geographical region if certain findings are
made and either regulations are issued or, if the taking is limited to
harassment, a notice of a proposed authorization is provided to the
public for review.
Authorization shall be granted if NMFS finds that the taking will
have a negligible impact on the species or stock(s), will not have an
unmitigable adverse impact on the availability of the species or
stock(s) for subsistence uses, and that the permissible methods of
taking and requirements pertaining to the mitigation, monitoring and
reporting of such takings are set forth. NMFS has defined ``negligible
impact'' in 50 CFR 216.103 as ''* * * an impact resulting from the
specified activity that cannot be reasonably expected to, and is not
reasonably likely to, adversely affect the species or stock through
effects on annual rates of recruitment or survival.''
Section 101(a)(5)(D) of the MMPA established an expedited process
by which citizens of the United States can apply for an authorization
to incidentally take small numbers of marine mammals by harassment.
Except with respect to certain activities not pertinent here, the MMPA
defines ``harassment'' as:
any act of pursuit, torment, or annoyance which (i) has the
potential to injure a marine mammal or marine mammal stock in the
wild [Level A harassment]; or (ii) has the potential to disturb a
marine mammal or marine mammal stock in the wild by causing
disruption of behavioral patterns, including, but not limited to,
migration, breathing, nursing, breeding, feeding, or sheltering
[Level B harassment].
\Section 101(a)(5)(D) establishes a 45-day time limit for NMFS
review of an application followed by a 30-day public notice and comment
period on any proposed authorizations for the incidental harassment of
marine mammals. Within 45 days of the close of the comment period, NMFS
must either issue or deny issuance of the authorization.
Summary of Request
On June 2, 2006, NMFS received an application from L-DEO for the
taking, by Level B harassment, of several species of marine mammals
incidental to conducting, with research funding from the National
Science Foundation (NSF), an acoustic calibration and seismic testing
program in the northern Gulf of Mexico in Fall, 2006. This project will
be conducted with L-DEO's new seismic vessel, the R/V Marcus G Langseth
(Langseth), which will deploy different configurations of airguns and a
different bottom-mapping sonar than used previously by L-DEO. L-DEO
requests that it be issued an IHA allowing Level B Harassment takes of
marine mammals incidental to the planned seismic surveys in the Gulf of
Mexico. A detailed description of the purpose of the calibration and
testing program was outlined in the NMFS notice of the proposed IHA (71
FR 58790, October 5, 2006).
Description of the Specified Activity
The Langseth is expected to depart Mobile, AL in July, 2007 (at the
earliest) and will transit to the survey area in the northern Gulf of
Mexico. The survey will encompass an area between 24[deg]N. and
31[deg]N. and between 83[deg]W. and 96[deg]W., which is within the
Exclusive Economic Zone (EEZ) of the U.S.A. The study will consist of
three phases: (1) an initial testing/shakedown phase, (2) measurements
of the sounds produced by various airgun arrays to be used by the
Langseth (calibration), and (3) a three-dimensional (3D) seismic
testing phase. The entire survey, calibration and testing included,
will take approximately 25 days and include approximately 1420 km (174
hours) of airgun operation. Measurements will be made during seismic
operations in three categories of water depth: shallow (<100 m or <328
ft), intermediate/slope (100-1000 m or 328-3281 ft), and deep (>1000 m
or >3281 ft). The vessel will transit to Galveston after the study is
completed. The exact dates of the activities will depend on logistics
and weather conditions.
The full airgun array on the Langseth consists of 36 airguns, with
a total discharge volume of 6600 in\3\. The array is made up of four
identical linear arrays or strings, with 10 airguns on each string. For
each operating string, nine airguns will be fired simultaneously, while
the tenth is kept in reserve as a spare, to be turned on in case of
failure of another airgun. The calibration phase will use the full 36-
airgun array and subsets thereof. The subsets will consist of either 1
string (9
[[Page 45745]]
airguns, 1650 in\3\) or 2 strings (18 airguns, 3300 in\3\). In
addition, sounds from a single 45 in\3\ GI gun and 2 GI guns (210
in\3\) will be measured. During the seismic testing phase, the 2-string
array will be used at most times, although the full 36-airgun array may
also be used. The ocean floor will be mapped with the 12-kHz Simrad
EM120 MBB sonar. This sonar will be operated from the Langseth
simultaneous with the airgun array during the seismic testing program,
but will likely be operated on its own during the acoustic calibration
study.
A more detailed description of the authorized action, including
vessel specifications and acoustic source specifications, was included
in the notice of the proposed IHA (71 FR 58790, October 5, 2006). Table
1 includes a summary of the use of the airgun configurations by phase
and depth.
[[Page 45746]]
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
9-Airgun Array (1 18-Airgun Array (2 36-Airgun Array (4
1 GI Gun 2 GI Guns 1 Single Airgun Strings) Strings) Strings)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Airgun Specifications ......................... ......................... ......................... ......................... ......................... ........................
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Energy Source One 45 in\3\ GI Airgun Two 105 in\3\ GI Airguns One 2000 psi Bolt Airgun Nine 2000 psi Bolt Eighteen 2000 psi Bolt Thirty-six 2000 psi Bolt
Airguns of 40-360 in\3\ Airguns of 40-360 in\3\ Airguns of 40-360 in\3\
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Air Discharge Volume (in\3\) 45 in\3\ 210 in\3\ 40 in\3\ 1650 in\3\ 3300 in\3\ 6600 in\3\
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Towing Depth of Source 2.5 m 3 m 6 m 6 m 6 m 6 m or 12 m
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Source Output (dB re 1 miPa 225.3 (230.7) 237 (243) ......................... 246 (253) 252 (259) 259 (265)
m) 0-pk (pk-pk)*
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Proposed Approximate Airgun Use ......................... ......................... ......................... ......................... ......................... ........................
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Calibration Phase ......................... ......................... ......................... ......................... ......................... ........................
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Shallow Site (30-60 m) 10 km 10 km ......................... 34 km 34 km 34 km
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Intermediate/Slope Site ......................... ......................... ......................... 34 km 34 km 34 km
(475 m)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Deep Site (1500) 10 km 10 km ......................... 45 km 45 km 45 km
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Testing Phase ......................... ......................... ......................... ......................... ......................... ........................
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Shallow (<100 m) ......................... ......................... 89 km 24 km 175 km 58 km
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Intermediate/Slope (100- ......................... ......................... 89 km 24 km 175 km 58 km
1000 m)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Deep (<1000 m) ......................... ......................... 89 km 24 km 175 km 58 km
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Table 1. L-DEO airgun configurations and proposed approximate use for each configuration by depth and phase.
* The root mean square values (typically discussed in biological literature) for these sources will generally be about 10-15 dB lower than those reflected here.
[[Page 45747]]
Safety Radii
L-DEO has estimated the safety radii around their operations using
a model, but also by adjusting the model results based on empirical
data gathered in the Gulf of Mexico in 2003. Additional information
regarding safety radii in general, how the safety radii were
calculated, and how the empirical measurements were used to correct the
modeled numbers may be found in NMFS proposed IHA (71 FR 58790, October
5, 2006) and Section I and Appendix A of L-DEO's application. Using the
modeled distances and various correction factors, Table 2 shows the
distances at which three rms sound levels (190 dB, 180 dB, and 160 dB)
are expected to be received from the various airgun configurations in
shallow, intermediate, and deep water depths.
----------------------------------------------------------------------------------------------------------------
Predicted RMS Radii (m)
Source and Volume Tow Depth (m) Water Depth ----------------------------------------------
190 DB 180 dB 160 dB
----------------------------------------------------------------------------------------------------------------
.............. Deep 9 25 236
Single Gi gun 3 Intermediate/ 13.5 38 354
Slope
45 in\3\ .............. Shallow 113 185 645
----------------------------------------------------------------------------------------------------------------
.............. Deep 20 69 670
2 Gi guns 3 Intermediate/ 30 104 1005
Slope
210 in\3\ .............. Shallow 294 511 1970
----------------------------------------------------------------------------------------------------------------
.............. Deep 12 36 360
Single Bolt 6 Intermediate/ 18 54 540
Slope
40 in\3\ .............. Shallow 150 267 983
----------------------------------------------------------------------------------------------------------------
1 string .............. Deep 200 650 6200
9 airguns 6 Intermediate/ 300 975 7880
Slope
1650 in\3\ .............. Shallow 1450 2360 8590
----------------------------------------------------------------------------------------------------------------
2 string .............. Deep 250 820 6700
18 airguns 6 Intermediate/ 375 1230 7370
Slope
3300 in\3\ .............. Shallow 1820 3190 8930
----------------------------------------------------------------------------------------------------------------
4 string .............. Deep 410 1320 8000
36 airguns 6 Intermediate/ 615 1980 8800
Slope
6600 in\3\ .............. Shallow 2980 5130 10670
----------------------------------------------------------------------------------------------------------------
4 string .............. Deep 620 1980 12000
36 airguns 12 Intermediate/ 930 2970 13200
Slope
6600 in\3\ .............. Shallow 4500 7700 16000
----------------------------------------------------------------------------------------------------------------
Table 2. Modeled distances to which sound levels 190, 180, and 160 dB re 1 microPa (rms) might be received in
shallow (<100 m), intermediate/slope (100-1000 m), and deep (>1000 m) water from the various sources planned
for use during the Gulf of Mexico study, fall 2007.
Comments and Responses
A notice of receipt of the L-DEO application and proposed IHA was
published in the Federal Register on October 5, 2006 (71 FR 58790).
During the comment period, NMFS received comments from the Marine
Mammal Commission (MMC) and the Center for Regulatory Effectiveness
(CRE). Following are the comments from the MMC and CRE and NMFS'
responses:
Comment 1: The MMC recommends that observations be made during all
ramp-up procedures to gather data regarding the effectiveness of ramp-
up as a mitigation measure.
Response: The IHA requires that MMOs on the Langseth make
observations for the 30 minutes prior to ramp-up, during all ramp-ups,
and during all daytime seismic operations and record the following
information when a marine mammal is sighted:
(i) Species, group size, age/size/sex categories (if determinable),
behavior when first sighted and after initial sighting, heading (if
consistent), bearing and distance from seismic vessel, sighting cue,
apparent reaction to the airguns or vessel (e.g., none, avoidance,
approach, paralleling, etc., and including responses to ramp-up), and
behavioral pace;
(ii) Time, location, heading, speed, activity of the vessel
(including number of airguns operating and whether in state of ramp-up
or power-down), sea state, visibility, and sun glare.
These requirements should provide information regarding the
effectiveness of ramp-up as a mitigation measure, provided animals are
detected during ramp-up.
Comment 2: The MMC recommends that the monitoring period prior to
the initiation of seismic activities be extended to one hour.
Response: As the MMC points out, several species of deep-diving
cetaceans are capable of remaining underwater for more than 30 minutes,
however, for the following reasons NMFS believes that 30 minutes is an
adequate length for the monitoring period prior to the start-up of
airguns: (1) because the Langseth is required to ramp-up, the time of
monitoring prior to start-up of any but the smallest array is
effectively longer than 30 minutes (Ramp up will begin with the
smallest gun in the array and airguns will be added in a sequence such
that the source level of the array will increase in steps not exceeding
approximately 6 dB per 5-min period over a total duration of 20-30
min), (2) in many cases MMOs are making observations during times when
sonar is not being operated and will actually be observing prior to the
30-minute observation period anyway, (3), the majority of the species
that may be exposed do not stay underwater more than 30 minutes, and
(4) all else being equal and if a deep diving individual happened to be
in the area in the short time immediately prior to the pre-start-up
monitoring, if an animal's maximum underwater time is 45 minutes, there
is only a 1 in 3 chance that his last random surfacing would be prior
to the beginning of the required 30-minute monitoring period.
Comment 3: The MMC recommends that the Service provide additional
[[Page 45748]]
justification for its proposed determination that marine mammal
detection ability by trained observers is close to 100 percent during
daytime (in good weather) and remains high at night.
Response: The Langseth is utilizing a team of trained MMOs to both
visually monitor from the high observation tower of the Langseth and to
conduct passive acoustic monitoring.
When stationed on the observation platform of the Langseth, the eye
level will be approximately 17.8 m (58.4 ft) above sea level, so the
visible distance (in good weather) to the horizon is 8.9 nm (16.5 km)
(the largest safety radii is 7.7 km (4.2 nm)). Big eyes are most
effective at scanning the horizon (for blows), while 7 X 50 reticle
binoculars are more effective closer in (MMOs also use a naked eye
scan). Additionally, MMOs will have a good view in all directions
around the entire vessel.
In some cases, particularly in shallow water and while deploying
streamers, chase boats will be deployed. The primary mission of the
chase boat is to warn boats that the seismic vessel is approaching and
thus the boat will be in front of the seismic vessel (generally about 2
nm). The plan is to have one MMO on the chase boat, who will advise the
Langseth of the presence of marine mammals in the operating area when
forward of the vessel and check for injured animals when aft of the
vessel.
Theoretical detection distance of this PAM system is 10s of
kilometers. One LGL biologist reported - ``Past experience in the GOM
would indicate good detection rates out to several kilometers. It is
not unreasonable to state that the PAM will detect most marine mammal
calls within the 3 km safety radius, particularly clicks from sperm
whales.'' The PAM is operated both during the day and at night.
Though it depends on the lights on the ship, the sea state, and
thermal factors, MMOs estimated that visual detection is effective out
to between 150 and 250 m using NVDs and about 30 m with the naked eye.
However, the PAM operates equally as effectively at night as during the
day, especially for sperm whales and dolphins (dolphins are the only
species likely to be detected in the ``shallow'' depths, where the
safety zones are the largest).
Comment 4: The MMC recommends that NMFS take steps to ensure that
the planned monitoring program will be sufficient to detect, with
reasonable certainty, all marine mammals within or entering identified
safety zones.
Response: Based on the information provided in the previous comment
(above) and the following information, NMFS believes that the planned
monitoring program will be sufficient to detect (using visual detection
and PAM), with reasonable certainty, all marine mammals within or
entering identified safety zones.
As mentioned above, the platform of the Langseth is high enough
that, in good weather, MMOs can see out to 8.9 nm (16.5 km). The PAM
has reliable detection rates out to 3 km and more limited ability out
to 10s of km. The largest 180-dB safety radii (3.2, 5.1, and 7.7 km),
which is the radii within which the Langseth is required to shut down
if a marine mammal enters, are found when the 9-gun, 18-gun, and 36-gun
arrays are operating in shallow water. The species most likely to be
encountered in the shallow water of the GOM, by far, are bottlenose and
Atlantic spotted dolphins, which have relatively larger group sizes (6-
10 animals for Atlantic spotted and 1-90 animals for bottlenose), are
not cryptic at the surface, and have relatively short dive times (< 2
minutes for Atlantic spotted and 5-12 minutes for bottlenose), all
which generally make them easier to visually detect. Additionally, the
vocalizations of these species are easily detected by the PAM.
Additionally, as mentioned above, MMOs on chase boats will sometimes be
used in addition to visual monitoring from the seismic vessels and PAM.
During the Maurice Ewing cruise in the GOM in 2003, MMOs detected
marine mammals at a distance of approximately 10 km from the vessel and
identified them to species at approximately 5 km from the vessel,
though the bridge of that vessel was only 11 m above the water (vs. the
Langseth, which is 17 m above). All of the 180-dB safety radii for
other depths are less than 3 km (all less than 2 km, except the 36-gun
array at intermediate depth, which is 2.97 km).
The likelihood of visual detection at night is significantly lower
than during the day, though the PAM remains just as effective at night
as during the day. However, the Langseth will not be starting up the
airguns unless the safety range is visible for the entire 30 minutes
prior (i.e., not an night), and therefore in all cases at night, the
airguns will already be operating, which NMFS believes will cause many
cetaceans to avoid the vessel, which therefore will reduce the number
likely to come within the safety radii. Additionally, because of normal
operating procedures, which entail beginning seismic operations as soon
after dawn as possible, at the most 33% of the actual airgun operation
(and much less, most likely) will occur at nighttime. With the
exception of operation of airguns in shallow water (which between the
9-, 18-, and 36-gun array totals about 18 hours), all of the other
safety radii are smaller than 3 km and fall easily within the reliable
detection capabilities of the PAM.
Comment 5: The CRE believes that NMFS should grant the Lamont-
Doherty Earth Observatory an IHA for L-DEO's proposed seismic
experiments in the GOM. However, the CRE recommended that NMFS revise
the IHA to state:
(1) There is no evidence that Gulf seismic operations complying
with the traditional 500 meter safety radii have injured marine mammals
or any other marine life.
(2) The much larger safety radii in the proposed IHA are based on
flawed models and unreliable data.
(3) Visual observation and PAM cannot accurately and reliably
monitor for marine mammals in safety radii significantly larger than
the traditional 500 meters.
Response:
(1) Neither the proposed IHA nor this Federal Register notice state
that Gulf seismic operations, utilizing any size safety zone, have
injured marine mammals. The proposed IHA states that there is ``no
specific evidence that exposure to pulses of airgun sound can cause PTS
in any marine mammal'' and that ``Airgun pulses are less energetic and
have slower rise times [than explosives], and there is no proof that
they can cause serious injury, death, or stranding even in the case of
large airgun arrays''.
(2) As CRE points out in their letter, L-DEO acknowledges in their
application the shortcomings of the 2003 data collection using airguns
in the GOM, however, this is the best available data for seismic sound
propagation in the GOM and L-DEO further explains (see proposed IHA)
how they use conservative correction factors in the development of
appropriate safety radii (based on the 180-dB criteria prescribed by
NMFS). The purpose of the current L-DEO seismic calibration is to
improve these data for use in future operations and MMPA
authorizations.
(3) NMFS believes that between visual monitoring and PAM the MMOs
can accurately and reliably detect marine mammals within safety radii
significantly larger than 500 m (see NMFS' responses to comments 3 and
4).
Description of Marine Mammals in the Activity Area
In the Gulf of Mexico, 28 cetacean species and one species of
manatee are known to occur (Jefferson and Schiro, 1997; Wursig et al.,
2000). In the U.S.,
[[Page 45749]]
manatees are managed by the U.S. Fish & Wildlife Service (USFWS), are
unlikely to be encountered in or near the open waters of the Gulf of
Mexico where seismic operations will occur, and are, therefore, not
addressed further in this document. Most of these species of cetaceans
occur in oceanic waters (>200 m or 656 ft deep) of the Gulf, whereas
the continental shelf waters (<200 m) are primarily inhabited by
bottlenose dolphins and Atlantic spotted dolphins (Mullin and Fulling
2004).
Seven species that may occur in the Gulf of Mexico are listed as
endangered under provisions of the U.S. Endangered Species Act (ESA),
including the sperm, North Atlantic right, humpback, sei, fin, and blue
whale, as well as the West Indian manatee. However, of those species,
only sperm whales are likely to be encountered. In addition to the 28
species known to occur in the Gulf of Mexico, another three species of
cetaceans could potentially occur there: the long-finned pilot whale,
the long-beaked common dolphin, and the short-beaked common dolphin
(Table 3). Though any pinnipeds sighted in the study area would be
extralimital, hooded seals have been reported in Florida and L-DEO has
requested authorization for the take of 2 animals.
During the 2003 acoustical calibration study in the Gulf of Mexico
from 28 May to 2 June, a total of seven visual sightings of marine
mammals were documented from the Maurice Ewing; these included a total
of approximately 38-40 individuals (LGL Ltd. 2003). In addition, three
sea turtles were sighted. These totals include times when airguns were
not operating as well as times
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
BEST MAXIMUM
Abundance in GOM and/or ------------------------------------------------------------------------------
Species Habitat Occurrence in GOM North Atlantic Approx. % of Ext. Exposures Approx.C% of
Estimated Exposures Population Auth IHA** Population
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Odontocetes
----------------------------------
Sperm whale Usually pelagic and deep Common 1349 / 13190 (add) 22 0.2 22 0.2
seas
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Pygmy sperm whale Deeper waters off the shelf Common 742 / 695 (add) 56 3.9 59 4.1
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Dwarf sperm whale Deeper waters off the shelf Common 742 / 695 (add) 56 3.9 59 4.1
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Cuvier's beaked whale Pelagic Rare 159 / 3196 (add) 10 0.3 21 0.7
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Sowerby's beaked whale Pelagic Extralimital 106 / 541 (add) 5 0.8 8 1.2
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Gervais' beaked whale Pelagic Uncommon 106 / 541 (add) 5 0.8 8 1.2
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Blainville's beaked whale Pelagic Rare 106 / 541 (add) 5 0.8 8 1.2
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Rough-toothed dolphin Mostly pelagic Common 2223 / 274 (add) 58 2.3 92 3.7
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Bottlenose dolphin Cont. shelf, coastal and Common 25,320 / 2239 / 29774 (add) 773 1.3 1713 5.0
offshore
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Pantropical spotted dolphin Mainly pelagic Common 91,321 / 13117 (add) 1282 1.2 1587 1.5
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Atlantic spotted dolphin Mainly coastal waters Common 30,947 / 52279 (add) 876 1.1 1755 0.2
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Spinner dolphin Pelagic in Gulf of Mexico Common 11,971 168 1.4 921 7.7
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Clymene dolphin Pelagic Common 17,355 / 6086 (add) 244 1.0 311 1.3
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Striped dolphin Off the continental shelf Common 6505 / 61546 (add) 91 0.1 134 0.2
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Short-beaked common dolphin Continental shelf and Possible 30,768 0 0.0 0 (5)** <0.1
pelagic waters
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Long-beaked common dolphin Coastal Possible N.A. 0 0.0 0 (5)** 0.0
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Fraser's dolphin Water >1000m Common 726 10 1.4 60 8.3
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Risso's dolphin Waters 400-1000m Common 2169 / 29110 (add) 54 0.2 81 0.3
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Melon-headed whale Oceanic Common 3451 49 1.4 142 4.1
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 45750]]
Pygmy killer whale Oceanic Uncommon 408 10 2.6 21 5.1
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
False killer whale Pelagic Uncommon 1038 14 1.4 28 2.7
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Killer whale Widely distributed Uncommon 133 / 6600 (add) 3 <0.1 5 0.1
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Short-finned pilot whale Mostly pelagic Common 2388 / 780000 / 14524 34 <0.1 98 <0.1
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Long-finned pilot whale Mostly pelagic Possible N.A. 0 ................... 0 (5)** ................
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Mysticetes
----------------------------------
North Atlantic right whale* Coastal and shelf waters Extralimital 291 0 ................... 0 ................
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Humpback whale* Mainly near-shore waters / Rare 11,570 / 10400 0 ................... 0 ................
banks
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Minke whale Coastal waters Rare 149,000 0 ................... 0 ................
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Bryde's whale Pelagic and coastal Uncommon 40 / 90000 1 2.5 2 5.0
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Sei whale* Primarily offshore, pelagic Rare 12-13,000 0 ................... 0 ................
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Fin whale* Cont. slope, mostly pelagic Rare 2814 / 47300 0 ................... 0 ................
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale* Coastal, shelf, and oceanic Extralimital 308 0 ................... 0 ................
waters
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Pinnipeds
----------------------------------
Hood seal Coastal Vagrant 400,000\z\ 0 ................... 0 (2)** <0.1
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Total 3770 ................... 7096 ................
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Table 3. Abundance, preferred hatitat, and commonness of the marine mammals species found in the survey area. The far right columns indicate the estimated number of each species that will be
exposed to 160 dB based on best and maximum density estimates. NMFS believes that, when mitigation measures are taken into consideration, the activity is likely to result in take of numbers
of animals less than those indicated by the best column, however, NMFS has authorized the number in this column.
* Federally listed endangered
** Parenthetical number indicates take authorization, though exposure estimate is 0
when airguns were firing. Visual monitoring effort consisted of
60.9 hours of observations (all in daylight) along 891.5 km of vessel
trackline on seven days, and passive acoustic monitoring (PAM) occurred
for approximately 32 hours. Most of the monitoring effort (visual as
well as acoustic) occurred when airguns were not operating, since
airgun operations were limited during the 2003 study. No marine mammals
were detected during acoustic monitoring. Marine mammal and sea turtle
sightings and locations during the 2003 calibration study are
summarized in Appendix C of L-DEOs application.
Additional information regarding the status and distribution of the
marine mammals in the area and how the densities were calculated was
included in the notice of the proposed IHA (71 FR 58790) and may be
found in L-DEO's application.
Potential Effects of the Activity on Marine Mammals
The effects of sounds from airguns might include one or more of the
following: tolerance, masking of natural sounds, behavioral
disturbance, temporary or permanent hearing impairment (Richardson et
al., 1995), or other non-auditory physiological effects such as stress,
neurological effects, bubble formation, resonance effects, and other
types of organ or tissue damage. To avoid injury, NMFS has determined
that cetaceans and pinnipeds should not be exposed to pulsed underwater
noise at received levels exceeding, respectively, 180 and 190 dB re 1
microPa (rms). The predicted 180- and 190-dB distances for the GI guns
operated by SIO are summarized in Table 2. Given the required
mitigation and monitoring measures, it is unlikely that there would be
any cases of temporary or, especially, permanent hearing impairment or
other serious non-auditory physiological effects.
The notice of the proposed IHA (71 FR 58790, October 5, 2006)
included a discussion of the effects of sounds from airguns on
mysticetes, odontocetes, and pinnipeds, including tolerance, masking,
behavioral disturbance, hearing impairment and other non-auditory
physical effects. Additional details on the behavioral reactions (or
the lack thereof) by all types of marine mammals to seismic vessels can
be found in Appendix A (e) of L-DEO's application.
The notice of the proposed IHA also included a discussion of the
potential effects of the bathymetric sonar. Because of the shape of the
beam of this source
[[Page 45751]]
and its power, NMFS believes it unlikely that marine mammals will be
exposed to bathymetric sonar at levels at or above those likely to
cause harassment. Further, NMFS believes that the brief exposure of
cetaceans or pinnipeds to small numbers of signals from the multi-beam
bathymetric sonar system are not likely to result in the harassment of
marine mammals.
Monitoring and Mitigation Measures
Monitoring
L-DEO will conduct mammal monitoring of its seismic program, in
order to implement the planned mitigation measures and to satisfy the
requirements of the IHA. More information regarding the Monitoring
program (including both visual observation and passive acoustic
detection) was included in NMFS' proposed IHA (71 FR 58790, October 5,
2006).
Vessel Based Monitoring
Vessel-based marine mammal observers (MMOs) will watch for marine
mammals near the seismic source vessel during all daytime airgun
operations and during any start ups of the airguns at night. When
feasible, observations will also be made during daytime periods without
seismic operations (e.g., during transits).
During seismic operations in the Gulf of Mexico, five observers
will be based aboard the vessel. MMOs will be appointed by L-DEO with
NMFS concurrence. At least one MMO, and when practical two MMOs, will
watch for marine mammals near the seismic vessel during ongoing daytime
operations and nighttime start ups of the airguns. MMO(s) will be on
duty in shifts of duration no longer than 4 h. The crew will also be
instructed to assist in detecting marine mammals and implementing
mitigation requirements (if practicable). Before the start of the
seismic survey the crew will be given additional instruction in how to
do so.
The Langseth is a suitable platform for marine mammal observations.
When stationed on the observation platform, the eye level will be
approximately 17.8 m (58.4 ft) above sea level, and the observer will
have a good view around the entire vessel. However, neither the actual
bow of the vessel nor the stern will be visible from the observation
platform, although it will be possible to see the airguns. To monitor
the areas immediately at the bow and stern of the vessel, two video
cameras will be installed at the bow (one on the starboard and one on
the port side), and a wide-angle camera will be installed at the stern.
Real-time footage from these cameras will be played on the observation
platform, so that the MMO(s) are able to monitor those areas. In
addition a high-power video camera will be mounted on the observation
platform to assist with species identification.
During daytime, the MMO(s) will scan the area around the vessel
systematically with reticle binoculars (e.g., 7 50 Fujinon), Big-eye
binoculars (25 150), and with the naked eye. At night, Night Vision
Devices (NVDs) will be available (ITT F500 Series Generation 3
binocular-image intensifier or equivalent), when required. Laser
rangefinding binoculars (Leica LRF 1200 laser rangefinder or
equivalent) will be available to assist with distance estimation. Those
are useful in training observers to estimate distances visually, but
are generally not useful in measuring distances to animals directly.
MMOs will not be on duty during ongoing seismic operations at
night. At night, bridge personnel will watch for marine mammals. If the
airguns are started up at night, two MMOs will watch for marine mammals
near the source vessel for 30 min prior to start up of the airguns
using NVDs, if the proper conditions for nighttime start up exist (see
Mitigation below).
The vessel-based monitoring will provide data to estimate the
numbers of marine mammals exposed to various received sound levels, to
document any apparent disturbance reactions or lack thereof, and thus
to estimate the numbers of mammals potentially ``taken'' by harassment.
It will also provide the information needed in order to power down or
shut down the airguns at times when mammals are present in or near the
safety radii. When a sighting is made, the following information about
the sighting will be recorded:
1. Species, group size, age/size/sex categories (if determinable),
behavior when first sighted and after initial sighting, heading (if
consistent), bearing and distance from seismic vessel, sighting cue,
apparent reaction to the airguns or vessel (e.g., none, avoidance,
approach, paralleling, etc.), and behavioral pace.
2. Time, location, heading, speed, activity of the vessel, sea
state, visibility, and sun glare.
The data listed under (2) will also be recorded at the start and
end of each observation watch, and during a watch whenever there is a
change in one or more of the variables.
All observations and power-downs or shut downs (see Mitigation
below) will be recorded in a standardized format. Data will be entered
into a custom database using a notebook computer. The accuracy of the
data entry will be verified by computerized validity data checks as the
data are entered and by subsequent manual checking of the database.
These procedures will allow initial summaries of data to be prepared
during and shortly after the field program, and will facilitate
transfer of the data to statistical, graphical, or other programs for
further processing and archiving.
Passive Acoustic Monitoring
Passive acoustic monitoring will take place to complement the
visual monitoring program. Visual monitoring typically is less
effective during periods of bad weather or at night, and even with good
visibility, is unable to detect marine mammals when they are below the
surface or beyond visual range. Acoustical monitoring can be used in
addition to visual observations to improve detection, identification,
localization, and tracking of cetaceans. The acoustic monitoring will
serve to alert visual observers when vocalizing cetaceans are detected.
It will be monitored in real time so that the visual observers can be
advised when cetaceans are detected.
SEAMAP (Houston, TX) will be used as the primary acoustic
monitoring system. This system was also used during previous L-DEO
seismic cruises (e.g., Smultea et al., 2004, 2005; Holst et al.,
2004a,b). The PAM system consists of hardware (i.e., the hydrophone)
and software. The ``wet end'' of the SEAMAP system consists of a low-
noise, towed hydrophone array that is connected to the vessel by a
``hairy'' faired cable. The array will be deployed from a winch located
on the back deck. A deck cable will connect from the winch to the main
computer lab where the acoustic station and signal conditioning and
processing system will be located. The lead-in from the hydrophone
array is approximately 400 m (1312 ft) long, and the active part of the
hydrophone array is approximately 56 m (184 ft) long. The hydrophone
array is typically towed at depths of less than 20 m or 66 ft.
The acoustical array will be monitored 24 hours per day while at
the seismic survey area during airgun operations and during most
periods when airguns are not operating. One MMO will monitor the
acoustic detection system at any one time, by listening to the signals
from two channels via headphones and/or speakers and watching the real-
time spectrographic display for frequency ranges produced by cetaceans.
MMOs
[[Page 45752]]
monitoring the acoustical data will be on shift from 1-6 h. All MMOs
are expected to rotate through the PAM position, although the most
experienced with acoustics will be on PAM duty more frequently.
When a vocalization is detected, the acoustic MMO will contact the
visual MMO immediately (so a power-down or shut down can be initiated,
if required), and the information regarding the call will be entered
into a database. The data to be entered include an acoustic encounter
identification number, whether it was linked with a visual sighting,
GMT date, GMT time when first and last heard and whenever any
additional information was recorded, GPS position and water depth when
first detected, species or species group (e.g., unidentified dolphin,
sperm whale), types and nature of sounds heard (e.g., clicks,
continuous, sporadic, whistles, creaks, burst pulses, strength of
signal, etc.), and any other notable information. The acoustic
detection can also be recorded onto the hard-drive for further
analysis.
Mitigation
L-DEO's study in the northern Gulf of Mexico will deploy an energy
source of up to 36 airguns (6600 in\3\). The airguns comprising the
array will be spread out horizontally, so that the energy will be
directed mostly downward. This directionality will result in reduced
sound levels at any given horizontal distance than would be expected at
that distance if the source were omnidirectional with the stated
nominal source level.
Localized and temporally-variable areas of concentrated feeding or
of special significance for marine mammals may occur within or near the
planned area of operations during the season of operations. However, L-
DEO will avoid conducting the activities near important concentrations
of marine mammals insofar as these can be identified in advance from
other sources of information, or during the cruise.
Safety Radii
As noted earlier (Table 2), received sound levels were modeled by
L-DEO for various configurations of the 36-airgun array in relation to
distance and direction from the airguns, and for a single and 2 GI
guns. Correction factors based on empirical measurements were applied
to estimate safety radii in shallow and intermediate-depth water. The
distances from the airguns where sound levels of 190, 180, and 160 dB
re 1 microPa (rms) are estimated to be received are shown Table 2.
Also, the safety radii for a single (40 in\3\) airgun are given, as
that source will be in operation when the 36-airgun array is powered
down. Airguns will be powered down (or shut down if necessary)
immediately when marine mammals are detected within or about to enter
the appropriate radius: 180 dB (rms) for cetaceans, and 190 dB (rms)
for pinnipeds, in the very unlikely event that pinnipeds are
encountered.
Mitigation During Operations
Mitigation measures that will be required will include (1) speed or
course alteration, provided that doing so will not compromise
operational safety requirements, (2) power-down procedures, (3) shut-
down procedures, (4) special shut-down procedures for baleen whales at
any distance, (5) ramp-up procedures, (6) avoidance of submarine
canyons and areas with known concentrations of marine mammals, if
possible, and (7) shut down and notification of NMFS if an injured or
dead marine mammal is found and is judged likely to have resulted from
the operation of the airguns.
Speed or Course Alteration--If a marine mammal or is detected
outside the safety radius and, based on its position and the relative
motion, is likely to enter the safety radius, the vessel's speed and/or
direct course may be changed. This would be done if practicable while
minimizing the effect to the planned science objectives. The activities
and movements of the marine mammal or sea turtle (relative to the
seismic vessel) will be closely monitored to determine whether the
animal is approaching the applicable safety radius. If the animal
appears likely to enter the safety radius, further mitigative actions
will be taken, i.e., either further course alterations or a power-down
or shut down of the airguns.
Power-down Procedures--A power-down involves decreasing the number
of airguns in use such that the radius of the 18-dB (or 190-dB) zone is
decreased to the extent that marine mammals are no longer in or about
to enter the safety zone. A power-down may also occur when the vessel
is moving from one seismic line to another (ie., during a turn). During
a power-down, one airgun will be operated. The continued operation of
one airgun is intended to alert marine mammals to the presence of the
seismic vessel in the area. In contrast, a shut down occurs when all
airgun activity is suspended.
If a marine mammal is detected outside the safety zone but is
likely to enter the safety radius, and if the vessel's speed and/or
course cannot be changed to avoid having the animal enter the safety
radius, the airguns will be powered down before the animal is within
the safety radius. Likewise, if a mammal or turtle is already within
the safety zone when first detected, the airguns will be powered down
immediately. During a power-down of the airgun array, at least one
airgun (e.g., 40 in3) will be operated. If a marine mammal is detected
within or near the smaller safety radius around that single airgun
(Table 2), all airguns will be shut down (see next subsection).
Following a power-down, airgun activity 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: (1) is visually
observed to have left the safety zone; or, (2) has not been seen within
the zone for 15 min in the case of small odontocetes and pinnipeds; or,
(3) has not been seen within the zone for 30 min in the case of
mysticetes and large odontocetes, including sperm, pygmy sperm, dwarf
sperm, and beaked whales.
During airgun operations following a power-down whose duration has
exceeded specified limits, the airgun array will be ramped up
gradually. Ramp-up procedures are described below.
Shut-down Procedures--During a power-down, the operating airgun
will be shut down if a marine mammal approaches within the modeled
safety radius for the then-operating source, typically a single 40 in3
gun or a GI gun (Table 2). If a marine mammal is detected within or
about to enter the appropriate safety radius around the small source in
use during a power-down, airgun operations will be entirely shut down.
Airgun activity will not resume until the animal has cleared the
safety zone, or until the MMO is confident that the marine mammal has
left the vicinity of the vessel. Criteria for judging that the animal
has cleared the safety zone will be as described in the preceding
subsection.
Special Shut-down Provision for Mysticetes--The airguns will be
shut down (not just powered down) if a mysticete is sighted anywhere
near the vessel, even if the whale is located outside the safety
radius. This measure is planned because of the assumed greater effects
of seismic surveys on mysticetes in general (as compared with other
marine mammals).
Ramp-up Procedures - A ramp-up procedure will be followed when the
airgun array begins operating after a specified-duration without airgun
operations. For the present cruise, this period would be approximately
10 min. This duration is based on provisions
[[Page 45753]]
during previous L-DEO surveys and on the approximately 180-dB radius
for the 4-string array in deep water in relation to the planned speed
of the Langseth while shooting. Ramp up will begin with the smallest
gun in the array. Airguns will be added in a sequence such that the
source level of the array will increase in steps not exceeding
approximately 6 dB per 5-min period over a total duration of 20-30 min.
During ramp up, the safety zone for the full airgun array to be used
will be maintained.
If the complete safety radius has not been visible for at least 30
min prior to the start of operations in either daylight or nighttime,
ramp up will not commence unless at least one airgun has been operating
during the interruption of seismic survey operations. That airgun will
have a source level of more than 180 dB re 1 microPa . m (rms). It is
likely that the airgun array will not be ramped up from a complete shut
down at night or in thick fog (the array will definitely not be ramped
up from a complete shut down at night in shallow water), because the
outer part of the safety zone for the array will not be visible during
those conditions. If one airgun has operated during a power-down
period, ramp up to full power will be permissible at night or in poor
visibility, on the assumption that marine mammals will be alerted to
the approaching seismic vessel by the sounds from the single airgun and
could move away if they choose. Ramp up of the airguns will not be
initiated if a marine mammal is sighted within or near the applicable
safety radii during the day or close to the vessel at night.
Avoidance of Areas with Concentrations of Marine Mammals - Beaked
whales may be highly sensitive to sounds produced by airguns, based
mainly on what is known about the
