[Federal Register Volume 72, Number 66 (Friday, April 6, 2007)]
[Notices]
[Pages 17118-17133]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-6488]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[I.D. 030607A]
Taking of Marine Mammals Incidental to Specified Activities; Open
Water Seismic Operations in Cook Inlet, Alaska
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice of issuance of two incidental harassment
authorizations.
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SUMMARY: In accordance with provisions of the Marine Mammal Protection
Act (MMPA) as amended, notification is hereby given that Incidental
Harassment Authorizations (IHAs) to take marine mammals, by harassment,
incidental to conducting seismic operations in the northwest portion of
Cook Inlet, Alaska, have been issued to ConocoPhillips Alaska, Inc.
(CPAI) and Union Oil Company of California (UOCC) for a period between
mid-March and mid-June, 2007.
DATES: The authorization for CPAI is effective from March 30 until May
31, 2007; and the authorization for UOCC is effective from May 1 until
June 15, 2007.
ADDRESSES: A copy of the application, IHA, Environmental Assessment
(EA), and/or a list of references used in this document may be obtained
by writing to P. Michael Payne, Chief, Permits, Conservation and
Education Division, Office of Protected Resources, National Marine
Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910-
3225, or by telephoning one of the contacts listed here (see FOR
FURTHER INFORMATION CONTACT).
FOR FURTHER INFORMATION CONTACT: Shane Guan, Office of Protected
Resources, NMFS, (301) 713-2289, ext 137, or Brad Smith, Alaska Region,
NMFS, (907) 271-3023.
SUPPLEMENTARY INFORMATION:
Background
Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)
direct the Secretary of Commerce to allow, upon request, the
incidental, but not intentional, taking of small numbers of marine
mammals by U.S. citizens who engage in a specified activity (other than
commercial fishing) within a specified geographical region if certain
findings are made and either regulations are issued or, if the taking
is limited to harassment, notice of a proposed authorization is
provided to the public for review.
An authorization shall be granted if NMFS finds that the taking
will have a negligible impact on the species or stock(s) and will not
have an unmitigable adverse impact on the availability of the species
or stock(s) for subsistence uses and that the permissible methods of
taking and requirements pertaining to the mitigation, monitoring and
reporting of such taking 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
small numbers of marine mammals. Within 45 days of the close of the
comment period, NMFS must either issue or deny issuance of the
authorization.
Summary of Request
On October 6 and on October 12, 2006, NMFS received applications
from CPAI and UOCC, respectively, requesting Incidental Harassment
Authorizations (IHAs) for the possible harassment of small numbers of
the Cook Inlet beluga whale (Delphinapterus leucas), Steller lions
(Eumetopias jubatus), Pacific harbor seals (Phoca vitulina richardsi),
harbor porpoises (Phocoena phocoena), and killer whales (Orcinus orca)
incidental to conducting open water seismic operations in portions of
Cook Inlet, Alaska. A detailed description of these activities was
published in the Federal Register on January 5, 2007 (72 FR 536). No
change has been made to these proposed activities.
Both proposed operations use an ocean-bottom cable (OBC) system to
conduct seismic surveys. OBC seismic surveys are used in waters that
are too shallow for the data to be acquired using a marine-streamer
vessel and/or too deep to have static ice in the winter. The proposed
operations would be active 24 hours per day, but the airguns would only
be active for 1 - 2 hours during each of the 3 - 4 daily slack tide
periods. The source for the proposed OBC seismic surveys would be a
900-in\3\ BOLT airgun array situated on the source vessel, the
Peregrine Falcon. The array would be made up of 2 sub-arrays, each with
2 3-airgun clusters separated by 1.5 m (4.9 ft) off the stern of the
vessel. One cluster will consist of 3 225-in\3\ airguns and the second
cluster
[[Page 17119]]
will have 3 75-in\3\ airguns. During seismic operations, the sub-arrays
will fire at a rate of every 10 - 25 seconds and focus energy in the
downward direction as the vessel travels at 4 - 5 knots (4.6 - 5.8
mph). Source level of the airgun array is 249 dB re 1 microPa at 1 m (0
- peak), and the dominant frequency range is 8 - 40 Hz.
The geographic region for the seismic operation proposed by CPAI
encompasses a 25 mi\2\ (65 km\2\) area in northwestern Cook Inlet,
paralleling the shoreline from just offshore of the Beluga River south
for about 6 km (3.7 miles). The approximate boundaries of the region of
the proposed project area are 61[deg]09.473'N, 151[deg]11.987'W;
61[deg]16.638'N, 151o02.198'W; 61[deg]12.538'N, 150[deg]49.979'W; and
61[deg]05.443'N, 151o00.165'W. Water depths range from 0 to 24 m (80
ft). There will be a 1.6 km (1 mile) setback of operations from the
mouth of the Beluga River to comply with Alaska Department of Fish and
Game (ADFG) restrictions. The proposed seismic operations would occur
from mid March depending on the time of ice breakup, and last until
mid-May, 2007.
The geographic region for the activity proposed by UOCC encompasses
a 28.2 km\2\ (10.9 square miles) area in northwestern Cook Inlet,
paralleling the shoreline offshore of Granite Point, and extending from
shore into the inlet to an average of about 1.6 km (1 mile). The
approximate boundaries of the region of the proposed project area are
61[deg]00.827'N, 151[deg]24.071'W; 61[deg]02.420'N, 151[deg]15.375'W;
61[deg]00.862'N, 150[deg]15.313'W; and 61[deg]57.979'N,
151[deg]23.946'W. There are no major rivers flowing into the open water
seismic project area. Water depths range from 0 to 18 m (60 ft). The
proposed seismic operations would begin as early as May 1 and end no
later than June 15, 2007.
Comments and Responses
A notice of receipt and request for 30-day public comment on the
applications and proposed authorizations was published on January 5,
2007 (72 FR 536). During the 30-day public comment period, NMFS
received the following comments from the Marine Mammal Commission
(Commission), the Humane Society of the United States (HSUS), the
Center for Biological Diversity (CBD), the Whales and Dolphin
Conservation Society (WDCS), the Animal Welfare Institute (AWI), CPAI,
the Center for Regulatory Effectiveness (CRE), and one private citizen.
General Comments
Comment 1: The Commission recommends that NMFS issue the IHAs
subject to the following stipulations:
(1) The applicants be required to institute monitoring and
mitigation measures sufficient to afford the potentially affected
marine mammals species adequate protection from sources of disturbance,
including disturbance of behavior;
(2) The period of observation be extended from 15 to 30 minutes
before it is assumed that an animal has moved beyond the safety zone;
(3) Observations be carried out during all ramp-up procedures to
gather data regarding the effectiveness of ramp-up as a mitigation
measures; and
(4) Operations be suspended immediately if a dead or seriously
injured marine mammals is found in the vicinity of the operations and
the death or injury could be attributable to the applicants'
activities. Any suspension should remain in place until NMFS has (a)
reviewed the situation and determined that further deaths or serious
injuries are unlikely or (b) issued regulations authorizing such takes
under section 101(a)(5)(A) of the MMPA.
Response: NMFS agrees with the Commission's comments and
recommendation that the applicants must institute monitoring and
mitigation measures sufficient to afford the potentially affected
marine mammal species adequate protection from sources of disturbance,
including disturbance of behavior. As an additional measure of marine
mammal monitoring, NMFS requires that CPAI conducting aerial monitoring
of Cook Inlet beluga whales in the vicinity of the project area during
seismic surveys between mid-March and mid-May (see Monitoring Section
later in this document). The aerial surveys would determine the
presence and relative numbers of belugas between east Susitna River and
North Foreland and determine the location of belugas relative to
seismic operations. No aerial monitoring is required for seismic
operations by UOCC since the proposed project area and time would not
have a relative high number of beluga whales.
NMFS also agrees with the Commission that the duration of pre-
operation monitoring be extended to 30 minutes to make sure that no
marine mammals are in the safety zone before the initiation of airgun
firing. As is standard under IHAs, observation would also be conducted
during all ramp-up procedures to ensure the effectiveness of ramp-up as
a mitigation measure.
NMFS further agrees with the Commission that seismic operations
must be suspended immediately if a dead or seriously injured marine
mammal is found in the vicinity of the project area and the death or
injury of the animal could be attributable to the applicants'
activities. This requirement is a conditions in the IHA.
Comment 2: CPAI urges NMFS to proceed with the authorization as
proposed in the Federal Register notice (72 FR 536, January 5, 2007)
and to require only the mitigation measures, monitoring and reporting
procedures listed in the notice, including: (1) limiting the time and
frequency of the operations and the use of airguns; (2) establishment
of safety zones; (3) vessel speed and course alteration; (4) power-down
procedures; (5) shut down procedures; (6) ramp-up procedures; (7) use
of qualified NMFS-approved vessel-based marine mammal observers (MMOs);
and (8) report of submission after the end of the project.
Response: The Federal Register notice (72 FR 536), published on
January 5, 2007, provides a detailed description of the proposed
seismic operations by CPAI and UOCC in upper Cook Inlet, the
anticipated impacts to marine mammal species and/or stocks and their
habitat within the project area, the potential effects on the
subsistence harvest of these marine mammal species and/or stocks, and a
list of proposed monitoring and mitigation measures to reduce the
potential impacts that would result from the proposed actions. A
thorough review by NMFS biologists of these projects, impacts, and
monitoring and mitigation measures led NMFS to reach a preliminary
determination the proposed projects, would result in no more than a
negligible impact on such species or stocks, and would not have an
unmitigable adverse impact on the availability of such species or
stocks for subsistence uses, provided that all monitoring and
mitigation measures are carried out.
After careful consideration, NMFS decided to add an additional
monitoring measure to require CPAI to also conduct aerial monitoring of
Cook Inlet beluga whales within its project area off Beluga River in
upper Cook Inlet to ensure beluga whales are not displaced from their
normal habitat. Please refer to the Monitoring Section later in this
document for a detailed description of CPAI's aerial monitoring plan.
In addition, CAPI and UOCC are required to conduct pre-survey
monitoring of marine mammals for 30 minutes to ensure that the safety
zone
[[Page 17120]]
is free of marine mammals prior to initiating airgun firing, and that
seismic operations must be suspended immediately if a dead or seriously
injured marine mammals is found in the vicinity of the operations and
the death or injury could be attributable to the applicants'
activities. All these requirements are conditions of the IHAs.
MMPA Concerns
Comment 3: CBD states that NMFS did not make the distinction
between ``small number'' and ``negligible impact'' while making the
decision in the Federal Register notice (72 FR 536, January 5, 2007).
Response: NMFS disagree. The analysis provided in the Federal
Register notice (72 FR 536, January 5, 2007) clearly described in
detail the numbers of Cook Inlet beluga whales, Pacific harbor seals,
and harbor porpoises that may be potentially taken by Level B
harassment as a result of the seismic operations in upper Cook Inlet.
Although no take number was estimated for Steller sea lions and killer
whales within the project area due to their rare presence based on
surveys conducted in recent years, NMFS believes that the harassment of
these species would be much less likely than those of beluga whales and
harbor seals. NMFS believes that the numbers for all affected species
are small.
NMFS conducts separate detailed analyses on the levels of take by
noise exposure and cumulative impacts to these marine mammal species
and stocks from a wide spectrum in the past, current, and foreseeable
future were also conducted and described in the aforementioned Federal
Register notice and in the EA. These analyses led NMFS to conclude that
while behavioral modifications, including temporarily vacating the area
during the project period may be made by these species to avoid the
resultant visual and acoustic disturbance, NMFS nonetheless finds that
this action would result in no more than a negligible impact on these
marine mammal species and/or stocks. NMFS also finds that the proposed
action would not have an unmitigable adverse impact on the availability
of such species or stocks for taking for subsistence uses. Please refer
to the Federal Register notice (72 FR 536, January 5, 2007) and the EA
for a detailed description of the analysis.
Comment 4: CBD questions whether NMFS used the ``best available
science'' in making its negligible impact statement. As CBD points out
that in making its determination, NMFS must give the benefit of the
doubt to the species rather than for the benefit of commercial
exploitation.
Response: NMFS disagree. Sections 101(a)(5)(A) and (D) of the MMPA
(16 U.S.C. 1361 et seq.) direct the Secretary of Commerce to allow,
upon request, the incidental, but not intentional, taking of small
numbers of marine mammals by U.S. citizens who engage in a specified
activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are issued or, if the taking is limited to harassment. An authorization
shall be granted if NMFS finds that the taking will have a negligible
impact on the species or stock(s) and will not have an unmitigable
adverse impact on the availability of the species or stock(s) for
subsistence uses and that the permissible methods of taking and
requirements pertaining to the mitigation, monitoring and reporting of
such taking are set forth. To reach a determination whether such take
constitute a negligible impact to the marine mammal species or
stock(s), NMFS must use the best available scientific information.
In reaching the determination for issuance of two IHAs for
conducting seismic surveys in upper Cook Inlet, NMFS has consulted a
number of scientific studies in this field and prepared an EA based on
the most recent peer-reviewed information. Where information is
unobtainable because of ethical concerns regarding conducting invasive
and injurious effects on marine mammals, surrogate species or
appropriate modeling is used in lieu of empirical information on marine
mammals. This information are reviewed by the Commission and its
Scientific Advisors, some of whom are experts on assessing impacts on
marine mammals from underwater sound sources. The information contained
in the EA has also been reviewed by endangered species biologists at
NMFS Anchorage Field Office and expert in bioacoustics at NMFS Office
of Protected Resources. Please refer to the Federal Register notice (72
FR 536, January 5, 2007) and the EA for a detailed description of NMFS
analyses.
As NMFS has used the best science currently available in making its
negligible impact determination and because NMFS always gives the
benefit of the doubt to the species when making these determinations,
NMFS believes that no harm will occur to these affected species and/or
stocks.
Comment 5: The WDCS recommends that the IHA should not be issued
and that seismic surveying should not be allowed to take place in the
Cook Inlet. The WDCS further states that recent status review and
extinction assessment reveals that Cook Inlet beluga whale population
has not shown appreciable recovery since 1999, and should be listed
under the Endangered Species Act (ESA) as an endangered species. The
WDCS states that any added pressure to this population might push it
beyond recovery.
Response: NMFS disagrees. As stated here and in the EA, NMFS
determined that the proposed short-term action that has several
mitigation measures incorporated to reduce impacts to the lowest level
practicable would result in no more than a negligible impact on Cook
Inlet beluga whales (72 FR 536, January 5, 2007). The Cook Inlet beluga
whale listing action under the ESA is a separate action, that is
currently under NMFS review and consideration.
Comment 6: CBD states that it does not believe NMFS can lawfully
authorize any Level A harassment of Cook Inlet beluga whales.
Response: As stated in the Federal Register notice (72 FR 536,
January 5, 2007), no take by Level A harassment (injury) or death is
anticipated or authorized for the proposed Cook Inlet seismic
operations.
Comment 7: CBD states that in light of the impending listing of the
Cook Inlet beluga, NMFS should delay issuing any take authorization for
the species until the ESA process is complete.
Response: NMFS cannot legally delay issuing a take authorization
based on the impending listing of a species. Section 101(a)(5)(D) of
MMPA establishes a 45-day time limit for NMFS review of an IHA
application followed by a 30-day public notice and comment period on
any proposed authorizations for the incidental harassment of small
numbers of marine mammals. Within 45 days of the close of the comment
period, NMFS must either issue or deny issuance of the authorization.
An authorization shall be granted if NMFS finds, that as here, the
taking will have a no more than negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for subsistence uses and that
the permissible methods of taking and requirements pertaining to the
mitigation, monitoring and reporting of such taking are set forth, such
as the case of this action.
NEPA Concerns
Comment 8: The Commission is concerned about the potential impact
of the proposed activities in conjunction with other factors that might
be adversely affecting beluga whales (i.e.,
[[Page 17121]]
cumulative effects). The Commission states that such factors include
increased vessel traffic, contaminants, military operations, waste
management, urban runoff, and furthermore, a variety of new activities
that are planned for Cook Inlet during the period for which the
incidental taking authorizations are sought.
Response: NMFS concurs with the Commission's concern regarding the
potential impact of the proposed activities in conjunction with other
factors that might be adversely affecting the Cook Inlet beluga whale
stock. NMFS also believes that extra caution is needed when proceed in
authorizing any IHAs for Cook Inlet beluga whales, due to the
precarious situation of this stock. Therefore, NMFS has conducted a
detailed analysis on the cumulative impact on the environment which may
result from the incremental impact of the proposed short-term seismic
survey action when added to other past, present, and reasonably
foreseeable future actions within upper Cook Inlet. The analyses are
described in detail in the Environmental Assessment on the Issuance of
Incidental Harassment Authorizations to ConocoPhillips Alaska, Inc. and
Union Oil Company of California to Take Marine Mammals by Harassment
Incidental to Conducting Seismic Operations in Northwestern Cook Inlet,
Alaska.
Comment 9: CBD states that for the analyses on CPAI and UOCC's
applications, NMFS must consider these effects together with all other
activities that affect these species, stocks, and local populations,
other anthropogenic risk factors such as other industrial development,
climate change, and the cumulative effect of these activities over
time.
Response: NMFS has conducted extensive analyses on the cumulative
impact to marine mammal species within the proposed action areas in the
EA. Please also refer to Response to Comment 8.
Comment 10: CBD states that NMFS cannot rationally adopt its EA and
make a Finding of No Significant Impact (FONSI). CBD states that NMFS
must prepare a full environmental impact statement (EIS) analyzing the
effects of the proposed seismic surveys in the context of the
cumulative effects of all other natural and anthropogenic impacts on
the marine mammals, habitats and communities of Cook Inlet.
Response: In December, 2006, NMFS prepared a draft EA for public
comment and review. During the 30-day comment period, rigorous reviews
were conducted by NMFS scientists in the NMFS Alaska Office and by
members of the Committee of Scientific Advisors on Marine Mammals of
the Commission. In view of the information presented in this document
and the analysis contained in the supporting draft EA prepared for this
proposed action, and the best available scientific information on
effects of sound on marine mammals, we have determined that the this
action would not significantly impact the quality of the human
environment.
In addition, monitoring and mitigation measures described in this
document and in the supporting draft EA when implemented will reduce
impacts on marine mammal stock to the lowest level practicable.
Furthermore, additional aerial monitoring measure for Cook Inlet beluga
whales is added to the requirements for seismic operations by CPAI near
Beluga River (see Monitoring Section below), which was included in the
Final EA. This additional aerial monitoring measure is contained in the
IHA issued to CPAI. In addition, all beneficial and adverse impacts of
the proposed action have been addressed to reach the conclusion of no
significant impacts. Accordingly, preparation of an EIS for this action
is not warranted. Subsequently, NMFS finalized the draft EA and issued
a FONSI on the proposed project.
Levels and Numbers of Marine Mammals Affected
Comment 11: CBD and one private citizen express their concerns that
there is a threat of serious injury and mortality to the Cook Inlet
beluga whales and other marine mammals from the proposed seismic
surveys.
Response: As described in detail in a Federal Register notice (72
FR 536) published on January 5, 2007, and in the draft EA for the
proposed action, NMFS has performed a thorough analysis on the levels
of potential impacts to Cook Inlet beluga whales and four other species
of marine mammals as a result of seismic operations in the upper Cook
Inlet. Based on this analysis, which is supported by the best available
scientific information, NMFS has come to the conclusion that only a few
beluga whales, Pacific harbor seals, harbor porpoises, Steller sea
lions, and killer whales may be taken incidental to seismic surveys, by
no more than Level B harassment and that such taking will result in no
more than a negligible impact on such species or stocks.
Therefore, NMFS believes that the authorized harassment takes
should be at the lowest level practicable due to incorporation of
mitigation measures described in the IHA, the EA, and in this document.
No take by Level A harassment (injury) or death is anticipated or
authorized, and harassment takes should be at the lowest level
practicable due to incorporation of strict monitoring and mitigation
requirements conditioned in the IHA. Please refer to the Federal
Register notice (72 FR 536, January 5, 2007) and the EA for a detailed
description of the analysis.
Comment 12: The Commission states that the estimated taking of up
to 57 beluga whales incidental to the two proposed projects can be
characterized as a small number of animals for purposes of making the
finding required under the MMPA. However, it represents more than one-
quarter of the IUCN's estimate of the number of mature animals in this
population (Lowry et al., 2006). Arguably, the Commission states that
this level of anticipated taking could have more than a negligible
impact on the survival and recovery of the stock. The Commission
believes that caution is warranted.
Response: NMFS agrees with the Commission that extra caution is
needed when authorizing any incidental take permits of Cook Inlet
beluga whales, due to the precarious situation of this stock. The IUCN
stated that the population of Cook Inlet beluga whale is estimated at
207 mature individuals (Lowry et al., 2006), however, there is no
mention of any population surveys the IUCN conducted to reach this
number. A Bayesian inference on the population size of Cook Inlet
beluga (1994 2005) provided by the IUCN on its website (http://www.iucnredlist.org/search/details/61442.pdf) showed that the
population estimate of Cook Inlet beluga whales to be over 300 (range:
approximately 290 400) whales, above NMFS' estimate of 278 whales, in
2005. In addition, the estimated potential take of up to 57 Cook Inlet
beluga whales would include all individuals, and the potential take
would be limited to only Level B behavioral harassment. Furthermore,
with the implementation of monitoring and mitigation measures discussed
in the EA and this document, NMFS believe the actual take by harassment
would be much lower. Therefore, NMFS does not believe that the
anticipated taking resulted from the proposed activities would have
more than a negligible impact on the survival and recover of the Cook
Inlet beluga whale stock.
Comment 13: CBD is concerned that beluga's foraging behavior and
the large tidal fluctuations in Cook Inlet pose high risk of stranding
at low tide even in the absence of anthropogenic disturbance.
Response: Beluga whale stranding events in upper Cook Inlet are not
uncommon. NMFS has reported 804
[[Page 17122]]
strandings (both individual and mass strandings) in upper Cook Inlet
since 1988 (Vos and Shelden, 2005). Mass stranding events primarily
occurred along Turnagain Arm, and often coincided with extreme tidal
fluctuations (``spring tides'') and/or killer whale sighting reports
(Shelden et al., 2003). These mass stranding events involve both adult
and juvenile beluga whales are are apparently healthy, robust animals.
It is uncertain why beluga whales strand in Cook Inlet. Beluga
whales are known to intentionally strand themselves during molting,
while rubbing their skin against rocky bottoms (NMFS, 2005). Beluga
whales may also strand purposely or accidentally to avoid predation by
killer whales. Stranded whales, particularly large adults, are at risk
of mortality due to stress, hyperthermia and suffocation. During two
mass stranding events in 1996 and 1999 involving about 120 whales, 9
adult whales died (Moore et al., 2000). In 2003, 115 beluga whales
stranded during five events. Five mortalities occurred during one of
these events when 46 animals stranded in Turnagain Arm (Vos and
Shelden, 2005). However, NMFS has determined that implementation of
mitigation measures described in this document, such as altering vessel
direction, power-down or shut-down of airguns when whales are detected
to be heading towards the safety zone, carrying out ramp-up procedure
when startup airguns, and conducting seismic surveys only during slack
tide periods, would prevent such stranding events from occurring.
Comment 14: HSUS states that the information provided and the
impact analysis for Cook Inlet belugas are not based on the most recent
sources. HSUS states that the most recent status review issued by NMFS
for Cook Inlet beluga (Hobbs et al., 2006) updates, and dramatically
expands on, information from the stock assessment. HSUS states that
only the most recent information should be used when considering the
status, distribution and effects on the stock.
Response: NMFS agrees with the HSUS that the most recent
information should be used when considering the status, distribution,
and effects of the stock. NMFS has updated the EA for this action with
new stock assessment data based on the most recent aerial surveys
conducted by NMFS National Marine Mammal Laboratory in the 2006 season.
The revised data updates the Cook Inlet beluga whale population at 302
whales (NMFS, unpublished data) from the previous 278 whales assessed
in 2005. However, NMFS does not agree with the HSUS that the Status
Review updates, and dramatically expands on, information from the stock
assessment. As stated in its Executive Summary, the Status Review
``provides a summary of the best available science to aid NMFS policy
makers'' in determining that the listing action may be warranted, and
therefore is consistent with NMFS Draft Conservation Plan for the Cook
Inlet Beluga Whale (Delphinapterus leucas) (draft Conservation Plan,
NMFS, 2005a).
Comment 15: HSUS, citing Hobbs, states that the range of beluga
whales has contracted considerably to focus during spring and summer
around river mouths in upper Cook Inlet, in the general area where the
seismic projects are proposed. HSUS states that the contracted smaller
ranges are very important habitat to a vulnerable population. HSUS is
concerned that the mitigation measures of ramping would displace beluga
whales and force them to utilize suboptimal habitat.
Response: In the Status Review (Hobbs et al., 2006) the statement
regarding the diminishing of the beluga whale's ranges provides the
following description:
``In the 1970s and 1980s, beluga sightings occurred across much of
the northern and central parts of Cook Inlet (Calkins 1984), but in the
1990s the summer distribution diminished to only the northernmost
portion of Cook Inlet (Rugh et al., 2000).''
The Status Review and the draft Conservation Plan, as supported by
NMFS long-term beluga whale surveys in Cook Inlet, showed that whales
do not just congregate around any river mouth in upper Cook Inlet. The
Status Review states that from late spring and throughout the summer
months, the majority of beluga probably feed on fish species that are
abundant in the Susitna River system and adjacent intertidal mudflats.
The proposed project area for CPAI, as described in detail in the
Federal Register notice (72 FR 536, January 5, 2007), is paralleling
the shoreline from just offshore of the Beluga River south for about 6
km, which is about 15 miles south of Susitna River mouth. This area is
in the extreme southern edge of the area classified by NMFS as Type 2
habitat (high value, summer feeding area) in its draft Conservation
Plan. Since the proposed CPAI seismic operations will be completed by
May 15, NMFS does not believe that this project would have significant
impact to beluga foraging activities. However to ensure that CPAI
survey does not have a significant impact, NMFS is requiring CPAI to
conduct an aerial monitoring program (see Monitoring Section). As for
the proposed UOCC seismic project, which would occur further south in a
latter period (from May 15 June 15) when the majority of Cook Inlet
belugas will be feeding around the Susitna River, Knik Arm, and
Tumagain Arm areas (Rugh et al., 2000), no aerial monitoring is
required. Therefore, it is not likely that the proposed seismic
operations and the mitigation measures will displace beluga whales from
their prime feeding ground or force them to utilize suboptimal habitat.
Please refer to the draft Conservation Plan and the EA for a detailed
description of beluga whales' temporal and spatial distribution in Cook
Inlet.
Comment 16: HSUS is concerned that displacing animals for up to 8
hours each day (1 2 hours during each of 3 4 daily slack tides) for a
period of months could have significant effects on foraging success and
thus fitness of individuals in this declining population. HSUS notes
that disturbance resulting in displacement by beluga whales does not
appear to have been considered in the draft EA. HSUS also states that
displacement even from a small area, if that area is important habitat,
could have serious long term impacts on Cook Inlet beluga. In addition,
citing Morton and Symonds (2002), HSUS states that killer whales and
harbor porpoises have been displaced from important habitat by seal
scrammers, a sound source similar to airguns.
Response: NMFS disagree. Regarding the potential concern of
displacing animals for up to 8 hours each day for the three-month
period, since the survey vessel will be moving as it is conducting
seismic surveys, NMFS does not believe that the whales will be
displaced from a particular location during the entire period. The most
likely scenario is that as the survey vessel conducts the surveys,
marine mammals including beluga whales will be temporarily displaced
from an approximately 370 m (1,214 ft) radius zone of influence (ZOI).
As the vessel moves around, the ZOI will be shifting constantly.
Therefore, no animal is expected to be displaced from an area for
longer than 1 2 hours. NMFS considers temporary (rather than long-term)
displacement of marine mammals as a form of behavior avoidance and is
discussed in the draft EA (page 28). Please refer to the EA, Cook Inlet
Beluga Conservation Plan, and Response to Comment 15 for additional
information on beluga whale habitat.
Regarding Morton and Symonds's (2002), HSUS incorrectly stated that
acoustic harassment devices (AHDs) and
[[Page 17123]]
airguns were similar in acoustic features. The sound produced by an AHD
is intermittent but is considered non-pulse, based on differences in
measurements between continuous and impulses sound level meters
(Harris, 1998). In addition, the 10-kHz Airmar AHD mentioned in Morton
and Symond's (2002) was designed specifically to cause physical pain to
seals, and the nature of killer-whale hearing (similar to most
odontocetes including belugas) makes this species vulnerable to impact
by this type of sound source as well. As a result, NMFS believes that
the AHD which was used from 1993 to 1999, is not be comparable to
seismic airguns as proposed to be used during the three-month long
seismic surveys proposed in Cook Inlet.
Comment 17: Citing NMFS Stock Assessment Reports (SARs), HSUS
points out that the Gulf of Alaska harbor seals should not be treated
as a single stock.
Response: Whether the Gulf of Alaska harbor seals should be
reclassified into more finely scaled stocks remains under study. Until
NMFS officially has adopted the revised stock reclassification based on
available scientific information, NMFS will continue to use the
existing stock information with the latest population abundance
assessment for management purposes under the MMPA. In addition, even if
the Cook Inlet harbor seals were to be reclassified as a separate
stock, NMFS does not believe that the proposed seismic project would
have significant impact to these animals due to the rare occurrence of
the harbor seals within the project area. The most recent count for
harbor seals within Cook Inlet is 7,330 seals (Josh London, National
Marine Mammal Laboratory. Pers. Comm. February 2007). NMFS calculated
that up to 30 Pacific harbor could be taken by Level B behavioral
harassment as a result of the seismic projects. Therefore, the
estimated take as a result of the proposed projects would represent 0.4
percent of the total seals in Cook Inlet.
Comment 18: HSUS points out that the Gulf of Alaska harbor porpoise
stock was recently revised from ``not strategic'' to ``strategic'' due
to poor and/or outdated abundance estimates.
Response: NMFS updated the information on Gulf of Alaska stock of
harbor porpoise in the EA, based on the newly released draft Stock
Assessment Report. The classification of the Gulf of Alaska harbor
porpoises to a strategic stock is largely due to lack of information on
incidental harbor porpoise mortality in commercial fisheries. The
population estimate for this stock has been revised from 30,506 to
41,854 porpoises. Therefore, the percentage of estimated take of the
Gulf of Alaska harbor porpoise by seismic surveys has been revised from
0.02 percent to 0.01 percent.
Comment 19: HSUS is concerned that information on harbor porpoise
densities in Cook Inlet was based on surveys done in 1991 1993,
therefore, the abundance data would not be accurate. HSUS further
states that harbor porpoises are not evenly distributed but ``tend to
clump in areas where forage conditions are more ideal, making them more
vulnerable to anthropogenic impacts in some areas than others.'' Citing
Rugh (2005), HSUS states that there were high densities of harbor
porpoises in two different areas in Cook Inlet.
Response: NMFS acknowledges that the survey studies on population
densities of Cook Inlet harbor porpoises cited (Dalheim et al., 2002)
were conducted 14 years ago, however, there is no evidence that these
data are not accurate. A reference search did not show that there are
any better or more recent studies available. Therefore, NMFS considers
that Dalheim et al.'s (2002) research on population densities of Cook
Inlet harbor porpoises is the best scientific information available
thus far.
The statement ``that harbor porpoises tend to clump in areas where
forage conditions are more ideal, making them more vulnerable to
anthropogenic impacts in some areas than others'' is not totally
relevant since the proposed seismic surveys do not necessarily seek
areas where forage conditions are good for marine mammals. Even if the
areas were the same, marine mammals clustered in groups would offer a
better opportunity to see them and implement appropriate mitigation.
NMFS assumes that the citation HSUS mentioned is Rugh et al.
(2005), NOAA Technical Memorandum NMFS-AFSC-149: Aerial Surveys of
Belugas in Cook Inlet, Alaska, June 2001, 2002, 2003, and 2004. In this
paper, Rugh et al. stated that twice they located high density areas
for harbor porpoises: south of Tuxedni Bay in 1994 and south of
Chinitna Bay in 2004. Both areas are located in lower Cook Inlet, which
are not the proposed project area. This statement supports NMFS
assessment in its EA that harbor porpoises tend to concentrate in lower
Cook Inlet.
Comment 20: Citing NMFS' draft EA that there is no abundance
estimate of Steller sea lions and killer whales in the proposed project
area, HSUS and the AWI state that this does not preclude the occurrence
of Steller sea lion within the project area and the analysis in the EA
is inadequate. HSUS further questions NMFS regarding source references
that Steller sea lions seldom occur in upper Cook Inlet besides data
from aerial surveys conducted in June and July.
Response: First, one should not interpret the statement in the
draft EA that no population estimate has been made for Steller sea
lions and killer whales within the proposed project area as that NMFS
has no knowledge whether these species occur in the area or not.
Repeated aerial surveys by NMFS for Cook Inlet beluga whales have
recorded any sighting of other marine mammals including Steller sea
lions and killer whales, however, no efforts were made to calculate the
abundance of these species due to their rare occurrence in the project
area (Rugh et al., 2005). In fact, Rugh et al. (2005) documented every
sighting of marine mammals in their beluga whale aerial survey report.
Although systematic surveys for beluga whales are usually conducted in
June and July, field observations were made by biologists in NMFS
Anchorage Office throughout the year on marine mammals within Cook
Inlet. All these observations point out that Steller sea lions are rare
in upper Cook Inlet (Brad Smith, NMFS Anchorage Office. Pers. Comm.
February 2007).
Acoustic Impacts
Comment 21: CBD, the AWI and the WDCS question NMFS assumption that
belugas would not be harassed by seismic sounds below 160 dB re: 1
microPa. CBD states that there are numerous studies showing significant
behavioral impacts from received sounds well below 160 dB. For example,
in its recent decision document related to seismic surveys associated
with oil and gas exploration in the Chukchi Sea, NMFS imposed a 120-dB
safety zone for aggregations of bowhead whales based on its finding
that ``bowhead whales apparently show some avoidance in areas of
seismic sounds at levels lower than 120 dB'' (MMS, 2006). Also harbor
porpoises have been reported to avoid a broad range of sounds low-
frequency (airgun pulses), mid-frequency (sonar transmissions), and
high-frequency (acoustic harassment devices) at very low sound pressure
levels (between 100 and 140 dB re: 1 microPa) (Kastelein et al., 2000;
Olesiuk et al., 2002; Calambokidis et al., 1998; NMFS, 2005b). AWI
states that whales have stranded and died after being exposed to lower
levels of sound, notably in the Bahamas incident of 2001.
[[Page 17124]]
Response: NMFS does not agree. As stated in the Federal Register
(72 FR 536, January 5, 2007) and the EA, one of the most important
aspects to assess the effects of high intensity sounds on marine
mammals is to understand their hearing sensitivity. For most small- and
medium-sized odontocetes (beluga whales included), the most sensitive
hearing ranges fall between 1 and 100 kHz (Richardson et al., 1995).
Although it has been reported that beluga whale's hearing extends to as
low as 40 75 Hz (Awbrey et al., 1988; Johnson et al., 1989), its
hearing threshold is at about 130 140 dB re: 1 microPa (Richardson et
al., 1995). The dominant frequencies (i.e., frequencies with highest
sound pressure levels) of the airguns to be used in the proposed
seismic operations are in the extreme low end of the spectrum (around
20 Hz). NMFS believes that at these low frequency ranges, the ability
for belugas to detect sound is greatly reduced, therefore, belugas are
not likely to be harassed.
While bowhead whales may be affected by seismic sounds above 120 dB
re: 1 microPa, they are mostly found within the Arctic, do not occur in
Cook Inlet and therefore will not be affected. Other mysticete species
are not expected in upper Cook Inlet. The harbor porpoise examples
given in the comments were exposed to acoustic signals with much higher
frequencies than the acoustic signals being produced by the proposed
project (150 3,500 Hz). For example, the experiment conducted by
Kastelein et al. (2000) used three types of sounds, all had harmonics
with high sound pressure levels above the range of 11 to 30 kHz. Gordon
et al. (1998) reported on experimental playbacks to harbor porpoises in
inshore waters around Orkney, United Kingdom using a small source air
gun (source level 228 dB re: 1 microPa zero-to-peak at 1 m) and
observed no changes in the rate of acoustic detection as a result of
sound exposure. In general, it is well known that harbor porpoises'
hearing sensitivity drops sharply as frequency goes under 8,000 Hz
(Andersen, 1970; Kastelein et al., 2002).
In addition, it is also important to understand that whether a
marine mammal would be harassed by sound or not also depends on the
context of the animal's behavior and the acoustical property of the
sound signal. It is also very possible that whales may not be harassed
when exposed to sound at received levels higher than 160 dB re: 1
microPa (e.g., Madsen and Mohl, 2000; Harris et al., 2001).
Furthermore, as discussed in the EA, the upper Cook Inlet is one of the
most industrialized and urbanized regions of Alaska. As such, ambient
noise levels are high and range from 100 120 dB re: 1 microPa
(Blackwell and Greene, Jr., 2002). Therefore, it is likely that marine
mammals in this region are habituated to these anthropogenic sounds.
NMFS does not concur with the AWI that there was a whale stranding
event in the Bahamas in 2001 caused by exposure to sound levels under
160 dB re: 1 microPa, as mentioned in its comment (no reference
provided). There was a mass stranding event in the Bahamas on March 15
16, 2000, which is possibly linked to naval exercises in the area (Cox
et al., 2006). Although no received levels and mechanism that caused
the stranding were determined, it was revealed that four of five ships
were using mid-frequency sonar (AN/SQS-53C: 2.6 3.3 kHz, approximately
235 dB re: 1 microPa SPL, AN/SQS-56: 6.8, 7.5, and 8.2 kHz,
approximately 223 dB re: 1 microPa SPL; Anon, 2001). These sounds are
very different from the seismic pulses in terms of frequencies,
amplitudes, and temporal patterns.
Comment 22: Citing a recently issued IHA by NMFS to the National
Science Foundation for conducting seismic surveys, CBD is concerned
that beluga whales could be displaced at a significant distance (up to
20 km, or 12.4 mi) from a sound source.
Response: NMFS notes that there have been observations that small
toothed whales sometimes move away, or maintain a somewhat greater
distance from the seismic vessel, when a large array of airguns is
operating than when it is silent (e.g., Calambokidis and Osmek, 1998;
Stone, 2003). Aerial surveys during seismic operations in the
southeastern Beaufort Sea recorded much lower sighting rates of beluga
whales within 10 20 km (16 - 32 mi) of an active seismic vessel. These
results were consistent with the low number of beluga sightings
reported by observers aboard the seismic vessel, suggesting that some
belugas might be avoiding the seismic operations at distances of 10-20
km (Miller et al., 2005). However, as noted in the Federal Register
notice referenced by the CBD (71 FR 43450, August 1, 2006), NMFS does
not consider minor movements away from an acoustic source to rise to
Level B harassment, since at the range of 7,097 and 10,646 m (4.4-6.6
mi; depending on ocean depths), received levels dropped down to below
160 dB re: 1 microPa.
Comment 23: The WDCS states the possibility that up to 57 Cook
Inlet beluga whales (up to 20 percent of the population) could be
subjected to 180-dB received level is unacceptable. Given the most
recent research survey, providing a population abundance estimate of
only 278 animals, it would be unacceptable for even one animal to be
subjected to the received levels proposed during the seismic surveys.
Response: NMFS does not think the WDCS statement is accurate. Based
on NMFS' calculation, as discussed in the draft EA, no Cook Inlet
beluga whales would be subjected to noise levels equal to or greater
than 180 dB re: 1 microPa (rms) from the proposed seismic surveys.
Based on NMFS' acoustic criteria, 180 dB re: 1 microPa (rms) is
considered to be the onset of TTS and exposure of cetaceans to this
level of noise will not be permitted under these IHAs. Strict
mitigation and monitoring measures described in the EA and required
under these IHAs will prevent any cetaceans from exposure to 180 dB re:
1 microPa (rms) or greater.
NMFS states that up to 57 beluga whales (representing 19 percent of
the population based on the most recent survey data) could be exposed
to noise levels of 160 dB re: 1 microPa (rms), which is the onset of
Level B behavioral harassment, as a result of the seismic operations.
Comment 24: CBD questions NMFS' Level A harassment criteria of 180
dB re: 1 microPa for cetacean and 190 dB re: 1 microPa for pinniped
species. CBD cites that in 2002, 2 Cuvier's beaked whales (Ziphius
cavirostris) were found to have stranded in the Gulf of California,
Mexico, coincident with geophysical surveys that were being conducted
in the area (Hildebrand, 2004), and in the same year, humpback whales
(Megaptera novaeangliae) were reported to have stranded in unusually
high numbers along Brazil's Abrolhos Banks, where oil-and-gas surveys
were being conducted (Engel et al., 2004). In addition, CBD states that
the western Pacific gray whales were displaced from feeding grounds and
exhibited behavioral changes in response to seismic surveys off
Russia's Sakhalin Island (Wursig et al., 1999). CBD also states that no
studies undertaken on the acoustic sensitivity of pinnipeds suggests
these species are at lower risk of threshold shift or auditory injury
than cetaceans (Kastak et al., 1999; 2005), and that harbor seals have
exhibited low discomfort thresholds to anthropogenic noise (Kastelein
et al., 2006).
Response: In 1998, scientists convened at the High Energy Seismic
Sound (HESS) Workshop, reviewed the available scientific information,
and agreed on the received sound levels above which marine mammals
might incur permanent tissue damage resulting in a permanent threshold
shift (PTS) of hearing. Shortly thereafter, a
[[Page 17125]]
NMFS panel of bioacousticians used the information gathered at the HESS
workshop to establish the current Level A Harassment acoustic criteria
for non-explosive sounds, 180 dB re: 1 microPa-m (rms) for cetaceans,
and 190 dB re: 1 microPa-m (rms) for pinnipeds, exposed to impulsive
sounds. In the absence of good sound scientific information for
specific species, NMFS conservatively adopt these criteria to establish
safety zones, within which monitoring or mitigation measures must be
applied, for all cetacean and pinniped species.
A study by Finneran et al. (2002) on bottlenose dolphin (Tursiops
truncatus) and beluga whale using a behavioral response paradigm and
exposing them to intense impulses from a seismic watergun showed that
masking temporary threshold shifts (MTTS) occurred after being exposed
to an impulsive sound of 160 kPa, or 226 dB re: 1 microPa p-p, with
total energy fluxes of 186 dB re: 1 microPa2-s for the beluga whale. No
MTTS was observed in the dolphin at the highest exposure conditions:
207 kPa, 228 dB re: 1 microPa p-p, and 188 dB re: 1 microPa2-s total
energy flux.
As for these two stranding examples cited in the comment
(Hildebrand, 2004; Engel et al., 2004) that occurred in the vicinity
where there had been seismic surveys conducted using powerful airguns,
a causation relationship between seismic surveys and strandings has yet
to be scientifically established. These references did not state that
seismic surveys are the cause of the strandings. Please see NMFS more
detailed response to these two events in the previous notice (69 FR
74906, December 16, 2004). NMFS notes that no measurements were made on
the distance between the acoustic source and the marine mammals. The
report by Wursig et al. (1999), which is also cited in the comment,
provided a detailed study of behavioral ecology of western Pacific gray
whale summering off Sakhalin Island. The report did not suggest that
the species were displaced from important feeding ground. On the
contrary, a follow up final report (Wursig et al., 2000) on the same
subject stated that ``whales did not appear to be displaced by
industrial activity.''
No comparable studies have been conducted on pinnipeds regarding
their responses to impulsive sounds. The two references (Kastak et al.,
1999; 2005) cited in the comment cannot be used to address the noise
responses of pinnipeds for the proposed project because animals in
these studies were exposed to octave-band noises for extended durations
(20 22 minutes in Kastka et al., 1999; 20, 25, and 50 minutes in Kastka
et al., 2005). In the third reference (Kastelein et al., 2006) cited in
the comment, harbor seals were also exposed to octave-band noise,
nonetheless, no TTS was observed. All these studies underscore the
importance of including sound exposure metrics (incorporating sound
pressure level and exposure duration) in order to fully assess the
effects of noise on marine mammal hearing, not just looking at the
absolute sound pressure levels.
Comment 25: HSUS uses an example that workers in loud factories
become habituated to noise in order to make money to feed their
families, but that does not insulate them from the multiplicity of
effects of stress or chronic sub-lethal conditions that may go
undetected by external monitoring, therefore, the habituation to high
level acoustic disturbance cannot be dismissed.
Response: NMFS does not believe that the HSUS' example of workers
working in noisy factories is a good analogue to marine mammals living
in a noisy environment due to the different contexts. In addition, such
comparison cannot be performed as HSUS did not provide quantitative
data on the noise levels of the ``loud factories'' that are presumed to
cause stress or chronic sub-lethal condition.
The marine environment is an efficient medium for sound propagation
and the ambient noise, as shown in many studies, are much higher
underwater than in air, although quantitative comparison is often
impossible due to different reference point in acoustic pressures
selected. Many of the sounds (e.g., those from marine life, wind, surf,
waves, rain, bubbles, ice, earthquakes, and thunder/lightning)
underwater occur naturally and are considered an intrinsic property of
the environment (Wenz, 1962; Diachok and Winokur, 1974; Arnold et al.,
1984; Wilson et al., 1984; Nystuen and Farmer, 1987; Richardson et al.,
1995; Tkalich and Chan, 2002; Ma et al., 2005). Therefore, marine
mammal hearing sensitivities may not reflect those of terrestrial
animals. Furthermore, the proposed seismic surveys would occur in a
short period of three months and are not confined in one fixed spot,
while the factory workers in HSUS' example are presumed to be working
in the same noisy environment for a number of years.
Comment 26: HSUS states that when describing the characteristics of
seismic sound, NMFS did not cite the most recent literature except
Richardson et al. (1995), Marine Mammal and Noise (Academic Press),
which HSUS considers to be outdated. HSUS brings NMFS attention to a
recent paper by Madsen et al. (2006) indicating that seismic airguns
generate significant sound energy at frequencies well above those of
interest to the surveyors. Citing Madsen et al. (2006), HSUS states
that received levels of up to 147 dB re: 1 microPa rms were generated
for higher frequencies, which may cause avoidance, stress, and masking
to marine mammals.
Response: NMFS disagrees. NMFS does not consider Richardson et
al.'s (1995) work as outdated. To the contrary, it is still one of the
most authoritative and widely cited literatures on characteristics of
seismic sound and airguns. In fact, Richardson et al. (1995) has noted
that low frequency airgun pulses contain energy in much higher
frequencies, which was also cited in our draft EA. NMFS is aware of
Madsen et al.'s work and considers it an important contribution to our
understanding of seismic sounds propagation in deep water.
In addition, NMFS does not believe that received levels from
inpulse noise (sound as seismic) of up to 147 dB re: 1 microPa rms
would cause a biologically significant response by marine mammal
species and stocks in Cook Inlet (see Response to Comment 21). However,
in recognition of the potential of horizontal propagation of sound
energy at higher frequencies, NMFS requires that safety zones based on
180 dB and 190 dB re: 1 microPa rms isopleths around the survey vessel
be established for cetacean and pinniped species, respectively at the
distance of greatest propagation. Please refer to the EA and Federal
Register notice (72 FR 536, January 5, 2007) for detailed information.
Comment 27: HSUS states that NMFS did not consider some of the more
recent work examining the impacts of seismic airguns on marine mammals.
HSUS brings NMFS attention to the proceedings from a workshop on this
issue by the International Whaling Commission (IWC) Scientific
Committee's Standing Working Group on Environmental Concerns. In
addition, HSUS states that very outdated sources (primarily from the
1990s) of empirical work on the impact of seismic airguns on marine
mammals were cited in the draft EA.
Responses: NMFS is aware of the proceeding by the 2006 IWC
Scientific Committee's Standing Working Group on Environmental Concerns
and has reviewed all its session papers on impacts of seismic surveys
on cetaceans. These papers and the proceeding were not considered in
the EA because none
[[Page 17126]]
of the session papers were peer-reviewed, and many are summaries of
original studies that were already included in the EA. Nonetheless, a
few of the new studies presented at the IWC did provide information on
long-range effects of airgun noise on marine mammals. For example,
field monitoring of seismic surveys by U.S. Geological Survey (USGS) in
Juan de Fuca Strait, Georgia Strait, Puget Sound, Hood Canal, and other
marine waters in British Columbia and Washington showed that most
marine mammals exhibited avoidance and Level B behavioral change when
exposed at 170 183 dB re: 1 microPa rms but were not affected when
levels were below 170 dB, except for harbor porpoises (Bain and
Williams, 2006). Although the authors stated that there were
insufficient numbers of individuals of marine mammals observed to merit
statistical analysis, the general observations support NMFS 160-dB
criteria for the onset of Level B behavioral harassment.
As regards to the sources used in the draft EA, NMFS does not
considered them outdated. All references NMFS used are peer-reviewed
and are cited in peer-reviewed papers. All these papers were tested in
time and thus NMFS considers them to be the best available scientific
information. A quick tally showed that among the 21 references cited on
noise impacts on marine mammals, 3 (14 percent) were published in the
1980s, 8 (38 percent) in the 1990s, and 10 (48 percent) in the 2000s.
Comment 28: HSUS states that the fact that cetaceans are near
vessels during airgun firing, even riding the bows of vessels towing
arrays is more a reflection of the characteristics of airgun sound
propagation than an indication that airgun pulses do not affect
cetaceans. HSUS states that there may well be sound shadows closer to
the vessel and the animals may be attracted to the vessels in an effort
to escape exposure to the blast.
Response: The Lloyd-mirror effect phenomenon, where acoustic energy
is diminished in a sound field near the surface where engine and
propeller noise from a ship is blocked by the vessel's hull, has been a
discussion regarding ship strike of large whales (Terhune and Verboom,
1999; Blue et al., 2001). However, it is highly unlikely that the
received levels would be reduced to the degree from the source (airgun
array) with no blockage between the source and the receivers.
Nonetheless, the IHAs require the surveyors to shut down the airgun as
soon as a marine mammal is sighted or believed to be inside the safety
zones, and no airgun can be started until 30 minutes after all marine
mammals have vacated the safety zones.
Comment 29: HSUS states that beluga whales react to low frequency
sounds from icebreaker ships, probably at the level at which they are
just able to detect them, up to 40 km away (Finley et al., 1990; Cosens
and Dueck, 1993). HSUS questions NMFS' assumption that beluga whales do
not react to low frequency sounds.
Response: NMFS does not agree with HSUS' extrapolation of beluga
reactions to approaching icebreaker ship sounds to predict their
responses to low-frequency seismic surveys. First, the acoustic
characteristics of an icebreaker do not resemble those from a seismic
airgun array. While seismic airguns produce transient sounds (pulses),
the noise from a ship is continuous sounds (non-pulses) (Richardson et
al., 1995). In addition, HSUS incorrectly classified sounds from
icebreaker ships as ``low-frequency.'' In fact, mid-point frequencies
of intense sound levels (over 162 dB re: 1 microPa) from icebreaker
ships recorded ranged from 50.1 Hz 5.01 kHz (Cosens and Dueck, 1993).
In a more recent study, the statistical source spectrum levels in 12th
octave bands between 100 Hz and 20 kHz from the Canadian Coast Guard
icebreaker Henry Larsen, were calculated at a median source level of
192 dB re: 1 microPa @ 1 m from bubbler system noise and 197 dB re: 1
microPa @ 1 m for noise associated with propeller cavitation along this
entire frequency range (Erbe and Farmer, 2000). Therefore, their
effects of noises from icebreaking ships and seismic airguns to marine
mammals cannot be compared. Furthermore, the contexts of the acoustic
signals and the prior exposure of anthropogenic sounds by the whales
need also to be taken into consideration when interpreting animal
responses. As suggested in both publications cited by HSUS (Finley et
al., 1990; Cosens and Dueck, 1993), the beluga whale reactions to
icebreaker noise at unprecedented ranges in the remote Canada High
Arctic was probably due to the fact that these animals are relatively
naive with respect to exposure to industrial noise. Richardson et al.
(1995) also suggested that the acute responsiveness to icebreakers was
probably caused by the partial confinement of whales by heavy ice,
scarcity of ships in the high arctic in spring, and ideal sound
propagation conditions (LGL and Greeneridge, 1986).
Comment 30: HSUS states that there is an overemphasis on avoidance
behavior and hearing loss when discussing the potential impacts of the
seismic surveys on marine mammals in Cook Inlet in NMFS' draft EA.
Citing the IWC Report of the Standing Working Group on Environmental
Concerns (2006), HSUS states that ``Clark and his colleagues...suggest
strongly that masking may be a significant problem for animals exposed
to seismic airguns,'' but it was not mentioned in the draft EA.
Response: NMFS considers that long-term displacement and hearing
loss as a result of anthropogenic sounds are biologically significant
impacts to marine mammals, as discussed in detail in the draft EA.
Therefore, NMFS considers it better to overemphasize and to call extra
attention to the reviewers and the public regarding the danger of these
impacts, than to have these issues overlooked. However, NMFS does not
believe beluga whale or other marine mammal acoustic communications
would be masked as a result from the seismic surveys. For the most
part, the low-frequency and intermittent seismic pulses, the high-
frequency communication calls of five species of marine mammals in Cook
Inlet, and the broadband echolocation signals from three cetacean
species do not overlap in either frequency or temporal domain. And the
non-sequential, high-frequency nature of cetacean communication signals
(whistles and pulsed calls) can be easily transmitted in between the
brief seismic pulses.
The IWC report (IWC, 2006) did not state or even suggest that
masking is a potential problem for marine mammals exposed to seismic
sounds. In fact, the only places ``masking'' is mentioned in that
report is when discussing noises from pile-driving, windfarms, and high
ambient noise environments. Clark and Gagnon (2006), in their session
paper presented at the 2006 IWC meeting, do not suggest that masking is
a problem for marine mammals exposed to seismic sounds. In fact,
``masking'' or ``mask'' was not mentioned in their paper (Clark and
Gagnon, 2006). This particular paper does state that highly sequential
and patterned low-frequency, narrowband mysticete songs often coincide
with the same acoustic features of seismic sounds. The paper also
provided examples showing acoustic maps for the 20 22 Hz frequency
band, where analyses indicate that fin whales would stop singing when a
seismic survey was operating but would resume singing within hours to
days after the survey stopped. NMFS does not think this would be the
case in Cook Inlet since there are no mysticeti species present.
[[Page 17127]]
Comment 31: The AWI and HSUS are concerned about seismic sound on
fish species and state that several recent studies demonstrating
hearing loss and widespread behavioral disruption in commercial species
of fish (Engas et al., 1996; Popper et al., 2003). HSUS further states
that the discussion of sound effects on fish seemed brief and sketchy.
HSUS suggests that the draft EA expands its discussion of the impacts
of seismic on other marine life. HSUS also points that some studies
cited in the draft EA suggest very strongly that marine mammal prey
might be negatively impacted by seismic surveys, either because they
are significantly displaced (e.g., Slotte et al., 2004) or because they
are physically injured (e.g., McCauley et al., 2003).
Response: The purpose of the EA is to evaluate environmental
impacts of issuing the two IHAs for incidental taking of marine mammals
by harassment will: (1) have a negligible impact on the marine mammal
species or stocks; and (2) not have an unmitigable adverse impact on
the availability of the species or stock for subsistence uses. However,
throughout the EA, NMFS provided a basic analysis on potential seismic
surveys impacts on marine environment, including fish species. The
analysis indicates that it is highly unlikely the marine environment,
including other marine species, would be significantly impacted as a
result of the proposed seismic surveys. Therefore, a more in depth
discussion on the effects of seismic surveys on other marine life is
beyond the scope of the EA.
The research conducted by Slotte et al. (2004) during the seismic
investigations off the Norwegian west coast, as cited in HSUS' comment,
did not find that pelagic fish (herring, blue whiting and mesopelagic
species) were displaced. This particular research recorded the acoustic
abundance of fish during the seismic surveys, and compared it with data
recorded directly prior to and after shooting along the seismic
transects. The comparison showed that although lower acoustic abundance
of fish was recorded during the shooting, there was not a difference in
fish abundance prior to and after shooting within the seismic area. The
authors state that these results indicate ``that the shooting had
insignificant short-term scaring effects.'' In addition, the authors
state that ``both blue whiting and mesopelagic species were found in
deeper waters in periods with shooting compared to periods without
shooting, indicating that vertical movement rather than horizontal
movement could be a short-term reaction to this noise.'' The word
``displacement'' or ``displace'' did not appear in the paper.
The experiments by McCauley et al. (2003), as cited in the comment,
were conducted by carrying out trials where pink snapper (Pagrus
auratus) were held in cages and were exposed to signals from an airgun
towed toward and away from the cages. The airgun, which has a source
level of 222.6 dB re: 1 microPa p-p (or 203.6 dB re: 1 microPa rms) at
1 m, was towed from start up at 400 - 800 m (1,312 - 2,615 ft) away to
5 - 15 m (16 - 49 ft) at closest approach to the cage. The study showed
that the ears of fish exposed to an operating air-gun sustained
extensive damage to their sensory epithelia that was apparent as
ablated hair cells. However, the authors cautioned that several caveats
must be considered when interpreting these results. Foremost of these
caveats was that the fish studied were caged and could not swim away
from the sound source. Video monitoring of behavior suggested that the
fish would have fled the sound source if possible. It is also likely
that many fish species hearing the approaching air-gun would swim away,
as has been observed on a large scale by Engas et al. (1996).
Comment 32: HSUS states that NMFS' draft EA overemphasizes TTS and
serious injury, as well as behavioral harassment, but ignores the
potential for increased stress, displacement to sub-optimal habitat
(even if only temporarily), and masking. The AWI, WDCS, and HSUS state
that the proposed mitigation measures are inadequate and will not
necessarily protect the marine mammals in the project area.
Response: NMFS believes that the proposed mitigation measures will
protect marine mammals from Level A harassment and TTS (Level B
harassment), as described in detail in the EA. These are standard
mitigation measures widely used for seismic operations and are
statutorily required in many countries (JNCC, 2004; Weir et al., 2006;
Wilson et al., 2006). Regarding the comments on potential increased
stress, displacement to sub-optimal habitat, and masking of marine
mammals, please refer to Responses to Comments 25, 15, and 30,
respectively.
Comment 33: HSUS states that the TTS data used in the draft EA are
primarily based on studies conducted on captive animals that have been
habituated to research protocols and a noisy environment (San Diego
Harbor). These TTS values have never been validated on free-ranging
naive animals, which at best might be more sensitive behaviorally than
captive animals and at worst might also be more susceptible to hearing
damage at lower received levels.
Response: It is true that three of the six studies on marine mammal
TTS cited in the draft EA were based on research conducted on animals
in San Diego Bay, however, recent studies on the same animals, which
was also cited in the EA, indicated that masking noise did not have a
substantial effect on the onset-TTS levels observed (Finneran et al.,
2005). These data represent the best scientific information available
to date. In addition, those TTS data were not used by NMFS as criteria
for onset of TTS. The criterion used by NMFS for onset-TTS is 180 dB
re: 1 microPa for cetaceans, which is much lower than levels reported
in these studies.
Regarding the validation of TTS values on free-ranging naive
animals, as noted in the HSUS comments, NMFS is not aware of any such
studies being conducted or other data existing, either within or
outside the United States.
Comment 34: AWI states that anthropogenic noise does not just
affect hearing organs, and that the hearing range of the Cook Inlet
belugas has not been assessed. AWI further states that presumably the
data used is from a few captive individuals, likely habituated to noise
over a length of time.
Response: NMFS agrees that anthropogenic noise does not just affect
hearing organs of marine mammals. For a detailed discussion on the
effects of anthropogenic noise on marine mammals, please refer to the
EA. Hearing sensitivity of beluga whales is well documented (White et
al., 1978; Awbrey et al., 1988; Johnson et al., 1989), and multiple
studies on beluga whales' behavioral audiograms from different
researchers largely agree with each other. Therefore, in view of the
scientific methods, there is no reason to believe that Cook Inlet
beluga whales would have significantly different hearing range than the
same species from different areas. In addition, habituation to noise
does not affect animal's hearing sensitivity, especially in the
experimental setting, where animals are rewarded to ``hear better.''
Monitoring and Mitigation
Comment 35: CBD questions whether NMFS has taken the ``means
effecting the least practicable impact'' on marine mammals when
implementing mitigation measures. CBD argues that the mitigation
requirement that the taking have the ``least practicable impact'' on
the species requires NMFS to consider a larger safety zone.
Response: NMFS disagrees. It may seem that a large safety zone
would be a more conservative mitigation measure
[[Page 17128]]
to ensure that marine mammals are not exposed to intense seismic sound
pressure levels. However, a larger safety zone often presents more
challenges in monitoring, and would compromise the effectiveness of
spotting marine mammals within or approaching the safety zones. In
addition, as mentioned in Response to Comment 22, and discussed in
detail in the Federal Register notice (72 FR 536, January 5, 2007) and
in the EA, carefully modeled and empirically field-verified safety
zones based on isopleths of 180 dB re: 1 microPa for cetaceans and 190
dB re: 1 microPa for pinnipeds are one of the most conservative
mitigation measures which allows the least practicable impact on the
species for this proposed action.
Comment 36: CBD states that the proposed requirements related to
monitoring of the safety zone for the proposed actions do not meet the
MMPA's standards because, for example, there is no requirement for
passive acoustic monitoring (PAM). The WDCS also recommends that PAM be
undertaken to enable an additional opportunity to detect marine mammals
in the survey area.
Response: NMFS disagrees. The MMPA has not established standards
for monitoring requirements. The monitoring requirements proposed are
to ensure that the taking will have a negligible impact on the species
or stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for subsistence uses.
Monitoring measures are also used to reduce the level of takes to the
lowest level practicable due to implementation of the mitigation
measures.
Monitoring measures for different project are proposed in a case-
by-case basis, and there is no ``one size fits all'' type of monitoring
procedures. For the proposed seismic projects in upper Cook Inlet, the
radius of the safety zone (370 m, or 1,214 ft) based on the 180 db re:
1 microPa isopleths is too small to allow accurate and effective
acoustic monitoring. As the Joint Nature Conservation Committee (JNCC,
2004) stated that in practice the exclusion zone (safety zone) need be
more than 500 m (1,640 ft) to allow for accurate passive acoustic
monitoring (PAM). JNCC also noted that in many cases PAM is not as
accurate as visual observation when determining range. NMFS believes
that in the subject seismic survey projects, where safety zone is
sufficient small, passive acoustic monitoring is not warranted. The
presence of additional vessels for deploying PAM would only introduce
more noise to the small area where the proposed projects are to occur.
However, as an additional monitoring measure, NMFS requires CPAI to
conduct aerial monitoring for its seismic surveys off Beluga River in
upper Cook Inlet. A detailed aerial monitoring plan is provided in the
Monitoring Section of this document.
Comment 37: The WDCS recommends that at least three marine mammal
observers (MMOs) should be available so that two visual observers are
on watch at all times during the survey. The Commission expresses its
concern that operations at night or under foggy condition may not
provide sufficient measure to protect marine mammals. The WDCS
recommends that no operations should take place at night or in sea
conditions above a sea state 2, where the likelihood of detection of
elusive and cryptic cetacean species, in particular beaked whales,
Kogia, harbor porpoises, and beluga whales dramatically decreases.
Response: NMFS agrees with the WDCS recommendation that at least
two MMOs should be available for visual monitoring at all times during
the survey, in addition, aerial monitoring will be required for all
seismic survey during day-light hours off Beluga River. NMFS does not
agree with the WDCS that seismic surveys need to be shut down at night
or in sea conditions above Beaufort sea state 2, as the safety zone is
small enough (370 m, or 1,214 ft, radius for 180 db re: 1 microPa) and
that the action area can be sufficiently monitored with night-vision
devices (NVDs), even at Beaufort sea state 2. The comment regarding
prohibiting seismic surveys at night is not practicable due to cost
consideration and ship time schedule. If the vessel is prohibited from
operating during nighttime, the survey would have to be extended for
much longer period of time and would not be beneficial to the marine
mammal species in the area. In addition, ramp-up prior to initiation of
seismic surveys will provide sufficient warning to marine mammals in
the project vicinity to temporarily vacate the project area for 1 2
hours. Therefore, NMFS does not believe that monitoring would be
compromised as a result of low-light and high waves.
No beaked whales and Kogia spp. are expected to occur in Cook
Inlet.
Comment 38: The Commission recommends that NMFS provide an
assessment of the likelihood of detecting marine mammals at or below
the surface within zones of potential impacts, particularly under less
than optimal conditions, prior to concluding that these measures will
be effective in ensuring that marine mammals are not exposed to
potentially harmful sound levels.
Response: NMFS believes that monitoring measures described in the
EA, in addition to aerial surveys monitoring, would detect all marine
mammals at or below the surface within zones of potential impacts.
Vessel-based monitoring procedures are standard measures that are
commonly used during seismic surveys. Especially for the proposed
activities, the safety zone is small enough due to the low-intensity
airgun array, visual monitoring from the survey vessel by two MMOs is
believed to be adequate. Though such monitoring does not guarantee that
there would be no marine mammals within the zones of influence during a
survey, NMFS also requires the ramp-up procedure before initiation of
airgun firing.
Comment 39: The AWI is concerned that ramp-up procedure has been
found to attract inquisitive animals to a noise source (no reference
provided).
Response: NMFS is not aware of any instances that an inquisitive
marine mammal has been attracted to a noise source during ramp-up of a
seismic survey. In any case, the IHAs will require that surveyors shut
down the airgun as soon as a marine mammal is sighted or believed to be
inside the safety zones. An inquisitive marine mammal moving to the
ship due to its inquisitive nature to the sound source will be easily
spotted before it enters the safety zone.
Comment 40: HSUS states that the safety zone is inadequate to
prevent or minimize stress, displacement, and masking.
Response: Regarding the establishment and effectiveness of the
safety zone, please referred to Response to Comment 21; regarding
potential stress, displacement, and masking, please refer to Responses
to Comments 15, 16, 21, 22, 24, and 25. Please also refer to the EA for
a thorough analysis of the mitigation and monitoring measures for the
proposed projects.
Other - ESA Listing, Subsistence Harvest, and Paper Reduction Act
Comment 41: CBD believes that the threats facing Cook Inlet beluga
are of sufficient magnitude and immediacy that NMFS should proceed with
an emergency listing provided by Section 4(b)(7) of the ESA and
designate the proposed seismic survey area in upper Cook Inlet as
critical habitat. The WDCS recommends that whilst NMFS has categorized
habitat according to its value and sensitivity, all habitats that the
Cook Inlet beluga whales use should be considered critical.
[[Page 17129]]
Response: As detailed in Federal Register notice (65 FR 34590, May
31, 2000), NMFS stated that the MMPA and ESA establish a specific
regulatory process for limiting subsistence harvest, and neither
statute includes emergency provisions to eliminate portions of the
process. Since recent subsistence harvest is considered to be the major
link directly to the decline of Cook Inlet beluga whales (NMFS, 2005a),
therefore, other emergency polices, strategies, or actions would not
likely promote recovery.
Critical habitat designations must be based on the best scientific
information available, in an open public process, within specific time-
frames. Before designating critical habitat, careful consideration must
be given to the economic impacts, impacts on national security, and
other relevant impacts of specifying any particular area as critical
habitat. The Secretary of Commerce may exclude an area from critical
habitat if the benefits of exclusion outweigh the benefits of
designation, unless excluding the area will result in the extinction of
the species concerned.
For additional information regarding Cook Inlet beluga whale
conservation, please refer to NMFS' (2005a) Draft Conservation Plan for
the Cook Inlet Beluga Whale (Delphinapterus leucas).
Comment 42: AWI states that the proposed project area is home to
endangered Steller sea lions and the Cook Inlet beluga whales that are
currently being considered by the U.S. Fish and Wildlife Service (FWS)
for listing under the ESA.
Response: As stated in the EA, Steller sea lion occurrence is rare
in Cook Inlet and its appearance during the project period is unlikely.
The Cook Inlet beluga whales are currently being considered by NMFS,
not the FWS as mentioned in the comment, for listing under the ESA.
Comment 43: CBD observes that given the very low subsistence take
of Cook Inlet belugas authorized in recent years, the injury or
mortality of even a single beluga by Conoco/Union Oil's activities
could very well have the effect of precluding any subsistence harvest
in a given year.
Response: The subsistence take of Cook Inlet belugas by the Alaskan
natives is currently managed under an interim harvest management plan
developed by the Alaska native organizations and NMFS (69 FR 17973,
April 6, 2004) and is not directly related to the proposed action. The
proposed action does not authorize any takes by Level A harassment
(injury) or death of any marine mammals within the proposed project
area in upper Cook Inlet, nor is such takes anticipated.
Comment 44: The CRE notes that they have not been successful in
identifying the Paperwork Reduction Act authorizations that would allow
NMFS to collect any seismic permit information.
Response: Applications and reporting requirements for small take
authorizations under sections 101(a)(5)(A) and 101(A)(5)(D) of the MMPA
have been approved by the Office of Management and Budget under control
number 0648-0151.
Description of Marine Mammals Affected by the Activity
Marine mammal species potentially occurring within the proposed
action area include the Cook Inlet beluga whales, Steller sea lions,
Pacific harbor seals, harbor porpoises, and killer whales. Among these
species, only the Steller sea lion is listed as endangered under the
ESA, and it is also designated as depleted under the MMPA. The Cook
Inlet beluga whale is designated as depleted under the MMPA. General
information for these species can be found in Angliss and Outlaw
(2006), which is available at the following URL: http://www.nmfs.noaa.gov/pr/pdfs/sars/ak2005.pdf. A more detailed description
of these species and stocks within Cook Inlet is provided in the
January 5, 2007, Federal Register (72 FR 536). Therefore, it is not
repeated here.
Potential Effects on Marine Mammals and Their Habitat
Seismic surveys using acoustic energy may have the potential to
adversely impact marine mammals in the vicinity of the activities
(Gordon et al., 2004). The sound source levels (zero to peak)
associated with the OBC seismic survey can be as high as 233 - 240 dB
re 1 microPa at 1 m. However, most energy is directed downward, and the
short duration of each pulse limits the total energy. Received levels
within several kilometers typically exceed 160 dB re 1 microPa
(Richardson et al., 1995), depending on water depth, bottom type, ice
cover, etc. Intense acoustic signals from seismic surveys have been
known to cause behavioral alteration such as reduced vocalization rates
(Goold, 1996), avoidance (Malme et al., 1986, 1988; Richardson et al.,
1995; Harris et al., 2001), and changes in blow rates (Richardson et
al., 1995) in several marine mammal species.
The proposed surveys would use a 900-in\3\ BOLT airgun array
consisting of 3 225-in\3\ airguns and 3 75-in\3\ airguns. The source
level of this array is expected to be considerably lower than the
1,200-in3 BOLT airgun array used by the U.S. Coast Guard (USCG) vessel
Healy (70 FR 47792, August 15, 2005). To conservatively assess the
received levels from airgun pulses, the USCG's Healy modeled data were
used to calculate the maximum distances where sound levels would be
190, 180, and 160 dB re 1 microPa rms. The maximum distances where
sound levels were estimated at 190, 180, and 160 dB re 1 microPa rms
from a single 1,200-in\3\ BOLT airgun in the northern Beaufort Sea were
313 m (1,027 ft), 370 m (1,214 ft), and 1,527 m (5,010 ft),
respectively. However, since the proposed seismic surveys would use a
smaller 900-in\3\ airgun array in an area with soft mud bottom that
gradually slopes outward from shore, which is a poor condition for
sound transmission (Richardson et al., 1995), the received levels are
expected to be significantly lower at these distances.
The seismic surveys would only introduce acoustic energy into the
water column and no objects would be released into the environment. The
survey vessel would travel at a speed of 4 - 5 knots and the two
projects would be conducted in a small area of Cook Inlet for a short
period of time.
There is a relative lack of knowledge about the potential impacts
of seismic energy on marine fish and invertebrates. Available data
suggest that there may be physical impacts on eggs and on larval,
juvenile, and adult stages of fish at very close range (within meters)
to seismic energy source. Considering typical source levels associated
with seismic arrays, close proximity to the source would result in
exposure to very high energy levels. Where eggs and larval stages are
not able to escape such exposures, juvenile and adult fish most likely
would avoid them. In the cases of eggs and larvae, it is likely that
the numbers adversely affected by such exposure would be very small in
relation to natural mortality. Studies on fish confined in cages that
were exposed under intense sound for extended period showed physical or
physiological impacts (Scholik and Yan, 2001; 2002; McCauley et al.,
2003; Smith et al., 2004). While limited data on seismic surveys
regarding physiological effects on fish indicate that impacts are
short-term and are most apparent after exposure at very close range
(McCauley et al., 2000a; 2000b; Dalen et al., 1996), other studies have
demonstrated that seismic guns had little effect on the day-to-day
behavior of marine fish and invertebrates (Knudsen et al., 1992; Wardle
et al., 2001). It is more likely that fish will swim away upon hearing
the approaching seismic impulses
[[Page 17130]]
(Engas et al., 1996). Based on the foregoing, NMFS finds preliminarily
that the proposed seismic surveys would not cause any permanent impact
on the physical habitats and marine mammal prey species in the proposed
project area.
Number of Marine Mammals Expected to Be Taken
NMFS estimates that approximately 6 - 57 Cook Inlet beluga whales
(average 26 whales) out of a population of 302 whales (NMFS,
unpublished data) and a maximum of 30 Pacific harbor seals out of a
population of 29,175 seals would be harassed incidentally by the two
proposed seismic operations from March to June, 2007. These numbers of
take represent 2.0 - 18.9 percent (average 8.6 percent) Cook Inlet
beluga whales and less than 0.1 percent of Alaska stock of Pacific
harbor seals that could be taken by Level B harassment if no mitigation
and monitoring measures are implemented. These numbers are based on the
animal density, length of track planned, and the assumption that all
animals will be harassed at distances where noise at received level is
at and above 160 dB re 1 microPa rms. Beluga whale and harbor seal
densities were calculated by dividing the daily counts of whales
(ranges from 11 - 99, with an average of 46) and seals (75) by the
approximate area (1,248 km\2\, or 482 square miles) surveyed in the
Susitna Delta (Beluga River to Pt. MacKenzie) during the most recently
published survey for June 2004 (Rugh et al., 2005). Although 18.9
percent of Cook Inlet beluga whales could subject to take by Level B
harassment, this estimate was based on an unusually high count of
whales on June 3, 2004 in Susitna Delta (from North Foreland to Pt.
Mackenzie). Cook Inlet beluga aerial surveys conducted by NMFS in June,
2003 and 2004, provided median counts of whales between 0 - 99, with an
average count of 29 whales in the same area. This estimate is
conservative as it assumes that all animals exposed by seismic impulses
over 160 dB re 1 microPa would be harassed and disturbed. As mentioned
earlier that the majority acoustic energy of low frequency airgun
impulses falls outside beluga whale's most sensitive hearing range
(Richardson et al., 1995), it is most likely that only a portion of
whales within the 160 dB re 1 microPa isopleth would be disturbed. In
addition, it is also possible that many of the animals would be
habituated to this level of acoustic disturbances. Furthermore,
mitigation measures, including the ramp-up requirement during the
initiation of the seismic operations (see below) could eliminate most,
if not all, startling behavior from animals near the proposed project
area. Therefore, NMFS believes that the actual number of Level B
harassment takes of Cook Inlet beluga whale would be much lower than
the estimated average of 26 whales.
There are no similar population surveys for harbor porpoises,
Steller sea lions, and killer whales conducted within the proposed
project area. However, based on an abundance survey of harbor porpoises
within the entire Cook Inlet (Dahlheim et al., 2000), it is estimated
that the population density of harbor porpoise in the entire Inlet is
0.0072 animal per km\2\. Based on this density data, NMFS estimates
that about 6 harbor porpoises out of a population of 30,506 porpoises
could be harassed incidentally by the two proposed seismic operations
from March to June, 2007. This number of take represents less than 0.02
percent of harbor porpoises that could be taken by Level B harassment.
There is no density estimates available for Steller sea lions and
killer whales with in Cook Inlet. However, their appearance in Upper
Cook Inlet is rare and none of these species were sighted in the upper
Inlet during the 2004 survey (Rugh et al., 2005). Therefore, NMFS
concludes that the harassment of these species is reasonably believed
to be much lower than those of beluga whales and harbor seals.
Effects on Subsistence Needs
The proposed project areas are located 4 - 15 miles (6.4 - 24.1 km)
from Tyonek, which is predominately a Dena'ina Athabaskan community.
However, these areas are not important subsistence areas for Tyonek
hunters. The Tyonek native community has been displaced from many
traditional hunting (and trapping and fishing) areas north of Tyonek
including Beluga River during the twentieth century. As more non-
natives utilized and occupied traditional subsistence areas combined
with harvest regulation restrictions, changes in the abundance and
distribution of subsistence resources, and other factors, Tyonek native
subsistence activities have focused closer to the village. While Tyonek
natives may harvest one beluga whale per year and occasionally harbor
seals (Huntington, 2000), their primary source of meat is moose
(Foster, 1982). Therefore, NMFS believes that the proposed projects
would not have an unmitigable adverse impact on the availability of
marine mammal species or stocks for subsistence harvest.
Mitigation
The following mitigation measures are required under the IHAs that
were issued to CPAI and UOCC for conducting seismic operations in
northwestern Cook Inlet. NMFS believes that the implementation of these
mitigation measures would result in the least practicable impact on
marine mammal species or stocks and their habitat.
Time and Frequency
Seismic operations will be limited from early March to mid-June in
portions of northwestern Cook Inlet. During the seismic operations,
airguns will only be active for 1 - 2 hours during each of the 3 - 4
slack tide periods, with the vessel moving at a speed of 4 - 5 knots
(4.6 - 5.8 mph).
There will be a 1.6 km (1 mile) set back of airguns from the mouth
of the Beluga River to comply with Alaska Department of Fish and Game
restrictions.
Establishment of Safety Zones
The applicants will establish a 370-m (1,214-ft) radius safety zone
for cetaceans and a 313-m (1,027-ft) radius safety zone for pinnipeds
for the seismic operations. These safety zone radii were calculated
from a model for a 1,200-in\3\ BOLT array used in the Beaufort Sea
where the received sound pressure levels (SPL) attenuated to 180 dB and
190 dB re 1 microPa rms, respectively. Since the data used in
calculating the size of safety zones were from a much larger array,
while the proposed seismic operations will use a smaller array in an
area with poor conditions for sound transmission, NMFS believes that
these safety zone radii are conservative. Additional data will be
acquired to verify the 190, 180, and 160 dB (rms) distances for the
airgun configurations during the proposed seismic operations, and the
disturbance could be modified if NMFS finds that the level of take is
being exceeded and resulting in higher than a negligible impact on the
species or stocks in question. An independent marine acoustic firm,
will be used to acquire the data. A scientifically valid sampling
design will be followed to collect data at the beginning of the seismic
program. The data will be used to calibrate the acoustic model and
adjust the safety radii to match the field values for the 190, 180, and
160 dB distances for each array, if different from these estimated
values.
Safety zones will be surveyed and monitored prior to, during, and
after the airgun seismic operations. A detailed description of marine
mammal
[[Page 17131]]
monitoring is described in the Monitoring and Reporting section below.
Speed and Course Alteration
If a marine mammal is detected outside the safety radius and based
on its position and the relative course of travel is likely to enter
the safety zone, the vessel's speed and/or direct course may, when
practicable and safe, be changed to avoid the impacts to the animal.
The marine mammal activities and movements relative to the seismic and
support vessels must be closely monitored to ensure that the animal
does not (1) approach the safety radius, or (2) enter the safety zone.
If either of these scenarios occur, further mitigation measures must be
taken (i.e., either further course alterations or power down or shut
down of the airgun(s)).
Power-down Procedures
A power down involves decreasing the number of airguns in use so
that the radius of the 180- or 190-dB zone is decreased to the extent
that marine mammals are not in the safety zone. During a power-down,
one airgun is operated. The continued operation of one airgun is
intended to alert marine mammals to the presence of the seismic guns in
the area.
If a marine mammal is detected outside the safety zone but is
likely to enter the safety zone, and if the vessel's course and/or
speed cannot be changed to avoid having the animal enter the safety
radius, the airguns must be powered down before the animal is within
the safety zone.
Shut-down Procedures
A shut-down occurs when all airgun activity is suspended. The
operating airgun(s) must be shut down if a marine mammal approaches the
applicable safety zone and a power down still would not likely to keep
the animal outside the newly adjusted smaller safety zone. The
operating airgun(s) must also be shut down completely if a marine
mammal is found within the safety zone during the seismic operations.
The shut-down procedure should be accomplished within several seconds
(of a ``one shot'' period) of the determination that a marine mammal is
within or about to enter the safety zone.
Following a shut-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 is visually observed
to have left the safety zone, or if it has not been seen within the
safety zone for 30 minutes.
Ramp-up Procedures
Although marine mammals will be protected from Level A harassment
by establishment of a safety zone at a SPL levels of 180 and 190 dB re
1 microPa rms for cetaceans and pinnipeds, respectively, mitigation may
not be 100 percent effective at all times in locating marine mammals.
In order to provide additional protection to marine mammals near the
project area by allowing marine mammals to vacate the area prior to
receiving a potential injury, and to further reduce Level B harassment
by startling marine mammals with a sudden intensive sound, CPAI and
UOCC are required to implement ``ramp-up'' practice when starting up
airgun arrays. Ramp-up will begin with the smallest airgun in the array
that is being used for all subsets of the 6-gun array. Airguns will be
added in a sequence such that the source level in the array will
increase at a rate no greater than 6 dB per 5 minutes. During the ramp-
up, the safety zone for the full 6-airgun system will be maintained.
Monitoring
Vessel-based Monitoring
Vessel based monitoring will be conducted by at least two qualified
NMFS-approved MMOs. Reticle binoculars (e.g., 7 x 50 Bushnell or
equivalent) and laser range finders (Leica LRF 1200 laser range finder
or equivalent) would be standard equipment for the monitors.
Vessel-based MMOs will begin marine mammals monitoring at least 30
minutes prior to the planned start of airgun operations and during all
periods of airgun operations. MMOs will survey the safety zone to
ensure that no marine mammals are seen within the zone before a seismic
survey begins. If marine mammals are found within the safety zone,
seismic operations will be suspended until the marine mammal leaves the
area. If a marine mammal is seen above the water and then dives below,
the operator will wait 30 minutes, and if no marine mammals are seen by
the MMOs in that time it will be assumed that the animal has moved
beyond the safety zone. Observations will also be conducted during all
ramp-up procedures to ensure the effectiveness of ramp-up as a
mitigation measure. When feasible, observations will also be made
during transits, moving cable, and other operations when airguns are
inactive.
Data for each distinct marine mammal species observed in the
proposed project area during the period of the seismic operations would
be collected. Numbers of marine mammals observed, species
identification if possible, frequency of observation, the time
corresponding to the daily tidal cycle, and any behavioral changes due
to the airgun operations will be recorded and 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.
Results from the vessel-based observations will provide: (1) Basis
for real-time mitigation (airgun shut-down); (2) information needed to
estimate the number of marine mammals potentially taken by harassment,
which must be reported to NMFS; (3) data on the occurrence,
distribution, and activities of marine mammals in the area where the
seismic study is conducted; (4) information to compare the distance and
distribution of marine mammals relative to the source vessel at times
with and without seismic activity; and (5) data on the behavior and
movement patterns of marine mammals seen at times with and without
seismic activity.
Aerial Monitoring
In addition to vessel monitoring, seismic surveys that will be
conducted off the Beluga River between mid-March and mid-May by CPAI
will also be required to conduct aerial monitoring. The aerial surveys
will: (1) determine the presence and relative numbers of beluga whales
between the west side of the Susitna River and North Foreland, (2)
determine the location of belugas relative to seismic operations, and
(3) record other marine mammals observed during the seismic surveys.
The aerial monitoring area will be centered on the project area
plus a buffer (from Susitna River to North Foreland) for detecting
belugas before or after they pass through the project area. The
boundary for the aerial survey extends approximately 7 mi (11 km) south
of the project area to the North Foreland, approximately 7 mi (11 km)
north to the Susitna River, West Fork, and 0.25 mi (0.4 km) from shore.
The size of the survey area provides a design for observing whales
before and during exposure to seismic sounds.
Aerial monitoring will be conducted from a single engine
helicopter, which will fly a single transect line paralleling the
shoreline along the coast in the project area. The survey will begin
from
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the north and finish by returning to the Beluga Gas Field, which will
be the base of helicopter operations. This pattern will be flown unless
observation conditions (glare, etc) require flying from south to north
depending on the effect of glare on observations. The helicopter will
fly at 1,500 ft (457 m), due to glide path needs, and at a ground speed
of 60 knot (111 km/h). This altitude should prevent disturbance of
marine mammals and birds by the helicopter noise.
Helicopter monitoring will be conducted at a frequency that
reflects the monthly abundance of belugas in the project area (LGL,
2006). The helicopter will be flown once per week in March when few if
any whales are expected in the project area. However, should belugas be
observed (by helicopter or boat), helicopter will be flown daily until
whales are not observed for two consecutive days. Once belugas are no
longer observed for two consecutive days, helicopter will be flown once
per week in March. Aerial monitoring will be increased to twice a week
through mid-April, until such time as belugas are observed, when
helicopter will be flown daily until whales are not observed for two
consecutive days. After mid-April, aerial monitoring will be conducted
daily when the number of belugas transiting through the project area to
the upper Cook Inlet is anticipated to be higher. Aerial monitoring
will fly 1 - 2 transects shortly before and half (0.50) of a transect
during seismic operations, which corresponds to the 3 - 4, 1-2 hour
slack tides each day. Half transects are flown during seismic
operations to prevent noise interference on the surveys. Half transect
flight direction will be determined by the relative position of
activities to the helicopter landing location. Aerial monitoring will
alternate over various tidal cycles when ever possible, since beluga
distribution may vary during the tidal cycles (LGL, 2006).
To the extent consistent with applicable aviation regulation,
aerial surveys will be conducted under the following conditions: (1)
when the pilot considers it safe to do so; (2) during daylight hours;
and (3) during good viewing conditions (ceiling height above 1,500 ft
(457 M) and Beaufort Sea States below 4. Flights will also be oriented
to minimize sun glare on the observer.
One NMFS-approved MMO will be on the helicopter observing and
recording marine mammals, covering the 180o view in front of the
helicopter. Space will be made available on the helicopter for NMFS
staff to participate in surveys at least twice a month.
Data from aerial monitoring will be recorded on the species,
number, group size, location (latitude/longitude), time, date,
direction of travel, angle from helicopter as determined by using a
clinometer, ceiling height, Beaufort Sea State, glare, weather, tide,
real time positions (latitude/longitude) of seismic survey vessel,
shooting, and vessel activities. Marine mammal behavior data will be
recorded when possible. Observation conditions will be recorded at the
start and finish of each survey or whenever conditions change. All
information collected during the marine mammal survey and/or reported
to the vessel will be recorded on a field form.
Land-based Monitoring
Land-based monitoring will be conducted by the MMO during days when
no aerial monitoring is practicable. Monitoring will be conducted at
Ladd Landing, a site previously used for land-based observations (LGL,
2006). The MMO will use binoculars to regularly scan the area visible
from the land site for marine mammals. Data recorded will include
sighting, weather, sea state, glare, amount of viewable area visible,
and seismic operation information. Sighting data will include species,
number, group size, direction of travel, date, time, and distance from
shore.
Reporting
Reports from aerial and land-based monitoring will be faxed or e-
mailed to NMFS Anchorage Field Office on a daily basis.
Reports from CPAI and UOCC will be submitted to NMFS within 90 days
after the end of the respective projects. The reports will describe the
operations that were conducted, the marine mammals that were detected
near the operations, and provide full documentation of methods,
results, and interpretation pertaining to all monitoring. The reports
will also include estimates of the amount and nature of potential
``take'' of marine mammals by harassment or in other ways.
National Environmental Policy Act (NEPA)
In January 2007, NMFS prepared a draft EA on the issuance of IHAs
to CPAI and UOCC to take marine mammals by harassment incidental to
conducting seismic operations in upper Cook Inlet, Alaska. The draft EA
was released for public review and comment along with the applications
and the proposed IHAs. During the 30-day public comment period NMFS
received comments from the HSUS, CBD, WDCS, and AWI on the draft EA.
All comments are addressed in full in the Comments and Responses
section. Subsequently, NMFS finalized the draft EA and on March 30,
2007, issued a Finding of No Significant Impact on the proposed
project.
Endangered Species Act (ESA)
Based on a review conducted by NMFS Alaska Regional Office
biologists, it is not likely that any ESA-listed species would be
affected due to the proposed seismic operations. Steller sea lions are
recorded in these waters, but are considered uncommon in spring and
early summer in the proposed project area. Therefore, NMFS has
determined that section 7 consultation is not necessary.
Determinations
NMFS has determined that small numbers of beluga whales, Pacific
harbor seals, and harbor porpoises may be taken incidental to seismic
surveys, by no more than Level B harassment and that such taking will
result in no more than a negligible impact on such species or stocks.
In addition, NMFS has determined that Steller sea lions and killer
whales, if present within the vicinity of the proposed activities could
be taken incidentally, by no more than Level B harassment and that such
taking would result in no more than a negligible impact on such species
or stocks. Although there is no estimated take numbers for Steller sea
lions or killer whales available due to their rare occurrence within
the project areas. Regardless, given the infrequent occurrence of these
species (or none at all), NMFS believes that any take would be
significantly lower than those of beluga whales or harbor seals.
While behavioral modifications, including temporarily vacating the
area during the project period may be made by these species to avoid
the resultant visual and acoustic disturbance, NMFS nonetheless finds
that this action would result in no more than a negligible impact on
these marine mammal species and/or stocks. NMFS also finds that the
proposed action will not have an unmitigable adverse impact on the
availability of such species or stocks for taking for subsistence uses.
In addition, no take by Level A harassment (injury) or death is
anticipated or authorized, and harassment takes should be at the lowest
level practicable due to incorporation of the mitigation measures
described in this document.
Authorization
NMFS has issued IHAs to CPAI and UOCC for the potential harassment
of
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small numbers of Cook Inlet beluga whales, Pacific harbor seals and
harbor porpoises incidental to conducting seismic operations in the
northwestern Cook Inlet in Alaska, provided the previously mentioned
mitigation, monitoring, and reporting requirements are incorporated.
Likewise, NMFS has issued IHAs for potential harassment of Steller sea
lions and killer whales incidental to conducting of seismic operations
in the northwestern Cook Inlet in Alaska, provided that previously
mentioned mitigation, monitoring, and reporting requirements are
incorporated.
Dated: March 30, 2007.
Angela Somma,
Acting Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. E7-6488 Filed 4-5-07; 8:45 am]
BILLING CODE 3510-22-S