[Federal Register: August 21, 2007 (Volume 72, Number 161)]
[Rules and Regulations]
[Page 46845-46893]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr21au07-18]
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Part III
Department of Commerce
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National Oceanic and Atmospheric Administration
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50 CFR Part 216
Taking and Importing Marine Mammals; Taking Marine Mammals Incidental
to the U.S. Navy Operations of Surveillance Towed Array Sensor System
Low Frequency Active Sonar; Final Rule
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 216
[Docket No. 070703226-7461-02; I.D. 062206A]
RIN 0648-AT80
Taking and Importing Marine Mammals; Taking Marine Mammals
Incidental to the U.S. Navy Operations of Surveillance Towed Array
Sensor System Low Frequency Active Sonar
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Final rule.
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SUMMARY: NMFS, upon application from the U.S. Navy, is issuing
regulations to govern the unintentional taking of marine mammals
incidental to Navy operation of the Surveillance Towed Array Sensor
System Low Frequency Active (SURTASS LFA) Sonar. Issuance of
regulations, and Letters of Authorization issued under these
regulations, is required by the Marine Mammal Protection Act (MMPA)
when the Secretary of Commerce (Secretary), after notice and
opportunity for comment, finds, as here, that such takes will have a
negligible impact on the affected species or stocks of marine mammals
and will not have an unmitigable adverse impact on their availability
for taking for subsistence uses. These regulations set forth the
permissible methods of take and other means of effecting the least
practicable adverse impact on the affected species or stocks of marine
mammals and their habitat.
DATES: Effective from August 16, 2007, through August 15, 2012.
ADDRESSES: A copy of the application, containing a list of references
used in this document, and other documents cited herein, 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, by telephoning one of the contacts listed under FOR FURTHER
INFORMATION CONTACT, or at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm
.
A copy of the Navy's Final Supplemental Environmental Impact
Statement (Final SEIS) and the Final Environmental Impact Statement
(Final EIS) can be downloaded at: http://www.surtass-lfa-eis.com.
Documents cited in this rule may also be viewed, by appointment, during
regular business hours at this address.
FOR FURTHER INFORMATION CONTACT: Kenneth Hollingshead, NMFS, at 301-
713-2289, ext 128.
SUPPLEMENTARY INFORMATION:
Background
Section 101(a)(5)(A) of the Marine Mammal Protection Act (16 U.S.C.
1361 et seq.) (MMPA) directs the Secretary of Commerce (Secretary) to
allow, upon request, the incidental, but not intentional taking of
marine mammals by U.S. citizens who engage in a military readiness
activity if certain findings are made and regulations are issued.
The MMPA directs the Secretary to allow the requested incidental
taking during periods of not more than 5 consecutive years each if the
Secretary finds that the total taking will have a negligible impact on
the affected species or stock(s), will not have an unmitigable adverse
impact on the availability of the species or stock(s) for certain
subsistence uses. The Secretary must also issue regulations setting
forth the permissible methods of taking and other means of effecting
the least practicable adverse impact, including a consideration of
personnel safety, the practicality of implementation of any mitigation,
and the impact on the effectiveness of the subject military readiness
activity, and the requirements pertaining to the monitoring and
reporting of such taking. These regulations do not themselves authorize
the taking of marine mammals. NMFS authorizes the incidental take
through ``letters of authorization'' (LOAs) (50 CFR 216.106). Prior to
issuance of an LOA, NMFS conducts a review of the activity and its
impact on marine mammals (via the required monitoring, reporting and
research) to ensure that the MMPA findings continue to be valid.
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.'' For the purposes of ``military readiness activities''
harassment is defined as:
(i) Any act that injures or has the significant potential to
injure a marine mammal or marine mammal stock in the wild [Level A
harassment]; or (ii) any act that disturbs or is likely to disturb a
marine mammal or marine mammal stock in the wild by causing
disruption of natural behavioral patterns, including, but not
limited to, migration, surfacing, nursing, breeding, feeding, or
sheltering, to a point where such behavioral patterns are abandoned
or significantly altered [Level B harassment].
The term ``military readiness activity'' is defined in Public Law
107-314 (16 U.S.C. 703 note) to include all training and operations of
the Armed Forces that relate to combat; and the adequate and realistic
testing of military equipment, vehicles, weapons and sensors for proper
operation and suitability for combat use. The term expressly does not
include the routine operation of installation operating support
functions, such as military offices, military exchanges, commissaries,
water treatment facilities, storage facilities, schools, housing, motor
pools, laundries, morale, welfare and recreation activities, shops, and
mess halls; the operation of industrial activities; or the construction
or demolition of facilities used for a military readiness activity.
Summary of Request
On May 12, 2006, NMFS received an application from the U.S. Navy
requesting an authorization under section 101(a)(5)(A) of the MMPA for
the taking of marine mammals by Level A and Level B harassment,
incidental to deploying the SURTASS LFA sonar system for military
readiness activities to include training, testing and routine military
operations within the world's oceans (except for Arctic and Antarctic
waters, coastal regions as specified in this rule, and offshore
biologically important areas (OBIAs)) for a period of time not to
exceed 5 years. According to the Navy's application, the Navy planned
to operate the SURTASS LFA sonar system on a maximum of 4 ships in
areas potentially including the Pacific, Atlantic, and Indian oceans
and the Mediterranean Sea.
SURTASS LFA sonar provides the Navy with a reliable and dependable
system for long-range detection of quieter, harder-to-find submarines.
Low-frequency (LF) sound travels in seawater for greater distances than
higher frequency sound used by most other active sonars. According to
the Navy, the SURTASS LFA sonar system would meet the Navy's need for
improved detection and tracking of new-generation submarines at a
longer range. This would maximize the opportunity for U.S. armed forces
to safely react to, and defend against, potential submarine threats
while remaining a safe distance beyond a submarine's effective weapons
range.
NMFS and the Navy have determined that the Navy's use of SURTASS
LFA
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sonar testing, training, and routine military operations constitute a
military readiness activity because those activities constitute
``training and operations of the Armed Forces that relate to combat''
and constitute ``adequate and realistic testing of military equipment,
vehicles, weapons and sensors for proper operation and suitability for
combat use.''
NMFS' current regulations governing takings incidental to SURTASS
LFA sonar activities and the current LOA extends through August 15,
2007.
On September 28, 2006 (71 FR 56965), NMFS published a Notice of
Receipt of Application on the U.S. Navy application and invited
interested persons to submit comments, information, and suggestions
concerning the application and the structure and contents of
regulations. These comments were considered in the development of the
proposed and final rules.
Prior Litigation, Involving LFA Sonar
On August 7, 2002, the Natural Resources Defense Council, the U.S.
Humane Society and four other plaintiffs filed suit against the Navy
and NMFS over SURTASS LFA sonar use and permitting. The U.S. District
Court for the Northern District of California (Court) issued its
Opinion and Order on the parties' motions for summary judgment in the
SURTASS LFA sonar litigation on August 26, 2003. The Court found
deficiencies in Navy and NMFS compliance with the MMPA, Endangered
Species Act (ESA), and National Environmental Policy Act (NEPA). The
Court determined that an injunction was warranted but did not order a
complete ban on the use of SURTASS LFA sonar. Specifically, the Court
found that a total ban on the employment of SURTASS LFA sonar would
interfere with the Navy's ability to ensure military readiness and to
protect those serving in the military against the threat posed by
hostile submarines. The Court directed the parties to meet and confer
on the scope of a tailored permanent injunction, which would allow for
continued operation of the system with additional mitigation measures.
The parties entered into a Stipulation Regarding Permanent Injunction
that allowed the Navy to operate SURTASS LFA sonar from both R/V Cory
Chouest and USNS IMPECCABLE (T-AGOS 23) in stipulated portions of the
Northwest Pacific/Philippine Sea, Sea of Japan, East China Sea, and
South China Sea with certain year-round and seasonal restrictions. The
Court entered the Stipulation as an Order on October 14, 2003. On July
7, 2005, following mediation by the parties, the Court amended the
injunction at Navy's request to expand the potential areas of operation
based on real-world contingencies. The Navy began work on an SEIS, in
response to the Court's ruling on the motion for preliminary
injunction. The Navy's Final SEIS, which was completed in April 2007,
not only addresses, the concerns identified by the Court in its ruling
on the merits of the parties' summary judgment motions, but it also
provides additional information regarding the environment that could
potentially be affected by the SURTASS LFA sonar systems, and
additional information related to mitigation.
A detailed description of the operations is contained in the Navy's
application (DON, 2006) and the Final SEIS (DON, 2007) which are
available upon request (see ADDRESSES).
Description of the Activity
The SURTASS LFA sonar system is a long-range, LF sonar (between 100
and 500 Hertz (Hz)) that has both active and passive components. It
does not have to rely on detection of noise generated by the target.
The active component of the system is a set of up to 18 LF acoustic
transmitting source elements (called projectors) suspended from a cable
underneath a ship. The projectors are devices that transform electrical
energy to mechanical energy by setting up vibrations, or pressure
disturbances, with the water to produce the pulse or ping. The SURTASS
LFA sonar acoustic transmission is an omnidirectional (full 360
degrees) beam in the horizontal. A narrow vertical beamwidth can be
steered above or below the horizontal. The source level (SL) of an
individual projector in the SURTASS LFA sonar array is approximately
215 decibels (dB), and because of the physics involved in beam forming
and transmission loss processes, the array can never have a sound
pressure level (SPL) higher than the SPL of an individual projector.
The expected water depth at the center of the array is 400 ft (122 m)
and the expected minimum water depth at which the SURTASS LFA sonar
vessel will operate is 200 m (656.2 ft).
The typical SURTASS LFA sonar signal is not a constant tone, but
rather a transmission of various signal types that vary in frequency
and duration (including continuous wave (CW) and frequency-modulated
(FM) signals). A complete sequence of sound transmissions is referred
to by the Navy as a ``ping'' and can last as short as 6 seconds (sec)
to as long as 100 sec, normally with no more than 10 sec at any single
frequency. The time between pings is typically from 6 to 15 minutes.
Average duty cycle (ratio of sound ``on'' time to total time) is less
than 20 percent; however, the duty cycle, based on historical operating
parameters, is normally 7.5 percent.
The passive, or listening, component of the system is SURTASS,
which detects returning echoes from submerged objects, such as
submarines, through the use of hydrophones. The hydrophones are mounted
on a horizontal array that is towed behind the ship. The SURTASS LFA
sonar ship maintains a minimum speed of 3.0 knots (5.6 km/hr; 3.4 mi/
hr) in order to keep the array deployed.
Because of uncertainties in the world's political climate, a
detailed account of future operating locations and conditions cannot be
predicted. However, for analytical purposes, a nominal annual
deployment schedule and operational concept have been developed, based
on current LFA sonar operations since January 2003 and projected Fleet
requirements. The Navy anticipates that a normal SURTASS LFA sonar
deployment schedule for a single vessel would involve about 294 days/
year at sea. A normal at-sea mission would occur over a 49-day period,
with 40 days of operations and 9 days transit. Based on a 7.5-percent
duty cycle, the system would actually be transmitting for a maximum of
72 hours per 49-day mission and 432 hours per year for each SURTASS LFA
sonar system in operation. (In actuality however, the combined number
of transmission hours for LFA sonar employed on both the R/V Cory
Chouest and the USNS IMPECCABLE (TAGOS 23) did not exceed 174 hours
annually between August 16, 2002, and August 15, 2006 (Table 4 in the
Navy's Final Comprehensive Report (Navy, 2007)).
Annually, each vessel will be expected to spend approximately 54
days in transit and 240 days performing active operations. Between
missions, an estimated 71 days will be spent in port for upkeep and
repair. The nominal SURTASS LFA Sonar annual and 49-day deployment
schedule for a single ship can be seen in Table 2-1 of the Final SEIS.
The two existing operational LFA sonar systems are installed on the
SURTASS vessels: R/V Cory Chouest and USNS IMPECCABLE (T-AGOS 23). To
meet future undersea warfare requirements, the Navy is working to
develop and introduce a compact active system deployable from existing,
smaller SURTASS Swath-P ships. This smaller system is known as Compact
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LFA, or CLFA sonar. CLFA sonar consists of smaller, lighter-weight
source elements than the current LFA sonar system, and will be compact
enough to be installed on the existing SURTASS platforms, VICTORIOUS
Class (T-AGOS 19) vessels. The Navy indicates that the operational
characteristics of the compact system are comparable to the existing
LFA sonar systems as presented in Subchapter 2.1 of the Final EIS and
Final SEIS. Consequently, the potential impacts from CLFA sonar will be
similar to the effects from the existing SURTASS LFA sonar systems.
Three CLFA sonar systems are planned for installation on T-AGOS 20, 21,
and 22. With the R/V Cory Chouest retiring in FY 2008, the Navy
estimates that there will be two systems in operation in FY 2008 and FY
2009, 3 in FY 2010 and 4 systems in FY 2011 and FY 2012. At no point
are there expected to be more than four systems in use, and thus this
rule analyzes the impacts on marine mammals due to the deployment of up
to three LFA sonar systems through FY 2010 and four systems in FY 2011
and FY 2012.
The SURTASS LFA sonar vessel will operate independently of, or in
conjunction with, other naval air, surface or submarine assets. The
vessel will generally travel in straight lines or racetrack patterns
depending on the operational scenario.
Description of Acoustic Propagation
The following is a very basic and generic description of the
propagation of LFA sonar signals in the ocean and is provided to
facilitate understanding of this action. However, because the actual
physics governing the propagation of SURTASS LFA sound signals is
extremely complex and dependent on numerous in-situ environmental
factors, the following is for illustrative purposes only.
In actual SURTASS LFA sonar operations, the crew of the SURTASS LFA
sonar platform will measure oceanic conditions (such as sea water
temperature and salinity versus depth) prior to and during
transmissions and at least every 12 hours, but more frequently when
meteorological or oceanographic conditions change. These technicians
will then use U.S. Navy sonar propagation models to predict and/or
update sound propagation characteristics. The short time periods
between actual environmental observations and the subsequent model runs
further enhance the accuracy of these predictions. Fundamentally, these
models are used to determine what path the LF signal will take as it
travels through the ocean and how strong the sound signal will be at
given ranges along a particular transmission path.
Accurately determining the speed at which sound travels through the
water is critical to predicting the path that sound will take. The
speed of sound in seawater varies directly with depth, temperature, and
salinity. Thus, an increase in depth or temperature or, to a lesser
degree, salinity, will increase the speed of sound in seawater.
However, the oceans are not homogeneous, and the contribution of each
of these individual factors is extremely complex and interrelated. The
physical characteristics that determine sound speed change with depth,
and in the case of temperature and salinity, season, geographic
location, and locally, with time of day. After accurately measuring
these factors, mathematical formulas or models can be used to generate
a plot of sound speed versus water depth. This type of plot is
generally referred to as a sound speed profile (SSP).
Near the surface (variable within the top 1000 ft (305 m)), ocean
near-surface water mixing results in a fairly constant temperature and
salinity. Below the mixed layer, sea temperature drops rapidly in an
area referred to as the thermocline. In this region, temperature
influences the SSP, and speed decreases with depth because of the large
decrease in temperature (sound speed decreases with decreasing
temperature). Finally, beneath the thermocline, the temperature becomes
fairly uniform and increasing pressure causes the SSP to increase with
depth.
One way to envision sound traveling through the sea is to think of
the sound as ``rays.'' As these rays travel through the sea, their
direction of travel changes as a result of speed changes, bending, or
refracting, toward areas of lower speed and away from areas of higher
speed. Depending on environmental conditions, refraction can either be
toward or away from the surface. Additionally, the rays can be
reflected or absorbed when they encounter the surface or the bottom.
For example, under certain environmental conditions, near-surface sound
rays can repeatedly be refracted upward and reflected off the surface
and thus become trapped in a duct.
Some of the more prevalent acoustic propagation paths in the ocean
include: acoustic ducting; convergence zone (CZ); bottom interaction;
and shallow-water propagation.
Acoustic Ducting
There are two types of acoustic ducting: surface ducts and sound
channels.
Surface Ducts
As previously discussed, the top layer of the ocean is normally
well mixed and has relatively constant temperature and salinity.
Because of the effect of depth (pressure), surface layers exhibit a
slightly positive sound speed gradient (that is, sound speed increases
with depth). Thus, sound transmitted within this layer is refracted
upward toward the surface. If sufficient energy is subsequently
reflected downward from the surface, the sound can become ``trapped''
by a series of repeated upward refractions and downward reflections.
Under these conditions, a surface duct, or surface channel, is said to
exist. Sound trapped in a surface duct can travel for relatively long
distances with its maximum range of propagation dependent on the
specifics of the SSP, the frequency of the sound (e.g., there is a low-
frequency cutoff dependent on the thickness of the duct), and the
reflective characteristics of the surface. As a general rule, surface
duct propagation will improve as the temperature uniformity and depth
of the layer increase. For example, transmission is improved when
cloudy, windy conditions create a well-mixed surface layer or in high-
latitude midwinter conditions where the mixed layer extends to several
hundred feet deep.
Sound Channels
Variation of sound speed, or velocity, with depth causes sound to
travel in curved paths. A sound channel is a region in the water column
where sound speed first decreases with depth to a minimum value, and
then increases. Above the depth of minimum value, sound is refracted
downward; below the depth of minimum value, sound is refracted upward.
Thus, much of the sound starting in the channel is trapped, and any
sound entering the channel from outside its boundaries is also trapped.
This mode of propagation is called sound channel propagation. This
propagation mode experiences the least transmission loss along the
path, thus resulting in long-range transmission.
At low and middle latitudes, the deep sound channel axis varies
from 1,970 to 3,940 ft (600 to 1,200 m) below the surface. It is
deepest in the subtropics and comes to the surface in the high
latitudes, where sound propagates in the surface layer. Because
propagating sound waves do not interact with either the sea surface or
seafloor, sound
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propagation in sound channels does not attenuate as rapidly as bottom-
or surface-interacting paths. The most common sound channels used by
SURTASS LFA sonar are convergence zones (CZs).
Convergence Zones
CZs are special cases of the sound-channel effect. When the surface
layer is narrow or when sound rays are refracted downward, regions are
created at or near the ocean surface where sound rays are focused,
resulting in elevated sound levels. The existence of CZs depends on the
SSP and the depth of the water. Due to downward refraction at shorter
ranges, sound rays leaving the near-surface region are refracted back
to the surface because of the positive sound speed gradient produced by
the greater pressure at deep ocean depths. These deep-refracted rays
often become concentrated at or near the surface at some distance from
the sound source through the combined effects of downward and upward
refraction, thus causing a CZ. CZs may exist whenever the sound speed
at the ocean bottom, or at a specific depth, exceeds the sound speed at
the source depth. Depth excess, also called sound speed excess, is the
difference between the bottom depth and the limiting, or critical
depth.
CZs vary in range from approximately 18 to 36 nautical miles (nm)
(33 to 67 km), depending upon the SSP. The width of the CZ is a result
of complex interrelationships and cannot be correlated with any
specific factor. In practice, however, the width of the CZ is usually
on the order of 5 to 10 percent of the range. For optimum tactical
performance, CZ propagation of SURTASS LFA sonar signals is desired and
expected in deep open ocean conditions.
Bottom Interaction
Reflections from the ocean bottom and refraction within the bottom
can extend propagation ranges. For mid- to high-level frequency sonars
(greater than 1,000 Hz), only minimal energy enters into the bottom;
thus reflection is the predominant mechanism for energy return.
However, at low frequencies, such as those used by the SURTASS LFA
sonar source, significant sound energy can penetrate the ocean floor,
and refraction within the seafloor, not reflection, dominates the
energy return. Regardless of the actual transmission mode (reflection
from the bottom or refraction within the bottom), this interaction is
generally referred to as ``bottom-bounce'' transmission.
Major factors affecting bottom-bounce transmission include the
sound frequency, water depth, angle of incidence, bottom composition
(e.g., sediments), and bottom roughness. A flat ocean bottom produces
the greatest accuracy in estimating range and bearing in the bottom-
bounce mode.
For SURTASS LFA sonar transmissions between 100 and 500 Hz, bottom
interaction would generally occur in areas of the ocean where depths
are between approximately 200 m (660 ft) (average minimum water depth
for SURTASS LFA sonar deployment) and 2,000 m (6,600 ft).
Shallow Water Propagation
In shallow water, propagation is usually characterized by multiple
reflection paths off the sea floor and sea surface. Thus, most of the
water column tends to become ensonified by these overlapping reflection
paths. As LFA sonar signals approach the shoreline, they will be
affected by shoaling, experiencing high transmission losses through
bottom and surface interactions. Therefore, LFA sonar would be less
effective in shallow, coastal waters.
In summary, for the SURTASS LFA sonar signal in low- and mid-
latitudes, the dominant propagation paths for LFA sonar signals are CZ
and bottom interaction (at depths less than 2000 m (6,600 ft)). In
high-latitudes, surface ducting provides the best propagation. In most
open ocean water, CZ propagation will be most prominent. The SURTASS
LFA sonar signals will interact with the bottom, but due to high bottom
and surface losses, SURTASS LFA sonar signals will not penetrate
coastal waters with appreciable signal strengths.
Comments and Responses
On September 28, 2006 (71 FR 56965), NMFS published a Notice of
Receipt of Application on the U.S. Navy SURTASS LFA sonar MMPA
application and invited interested persons to submit comments,
information, and suggestions concerning the application and the
structure and contents of regulations. Those comments were considered
in the development of the proposed rule. A proposed rule for renewal of
the regulations governing SURTASS LFA sonar MMPA authorization was
published on July 9, 2007 (72 FR 37404) with a 15-day public comment
period. During the two comment periods, comments were received from a
large number of organizations and individuals. Those organizations
include the Marine Mammal Commission (Commission), the Natural
Resources Defense Council (NRDC), Earth Island Institute (EII),
Acoustic Ecology Institute (AEI), Animal Welfare Society (AWI),
Cetacean Society Institute (CSI), Seaflow, International Ocean Noise
Coalition, Olympic Coast Alliance, Citizens Opposing Active Sonar
Threats, Ocean Care, Gesselschaft zur Rettung der Delphine, SBOOHER,
Ocean Conservation Research, Friends of the San Juans, World Society
for the Protection of Animals. We have addressed all comments on the
proposed rule. We also responded to comments that appear to be directed
solely at the draft SEIS, although we did not address comments strictly
related to non-marine mammal issues. See the Navy's Final SEIS, which
NMFS has adopted under NEPA.
Activity Concerns
Comment 1: The U.S. Navy seeks a blanket exemption to do harm to
all marine animals in 80 percent of the world oceans with only minor
mitigation measures taken. Expanding the SURTASS program into 80
percent of the world's oceans would make the task of monitoring the
impacts impossible. An LOA granted would not meet the ``negligible
impact'' condition and would violate the ``unmitigable adverse impact''
constraints indicated in the MMPA LOA process.
Response: The Navy is not seeking a ``blanket exemption'' from the
MMPA, but rather is requesting that NMFS issue regulations to govern
the incidental take of marine mammals under Section 101(a)(5)(A) of the
MMPA. Under these regulations the Navy must apply annually for a letter
of authorization (LOA) that would exempt the taking of marine mammals
incidental to the Navy's use of SURTASS LFA sonar from the MMPA's
general moratorium on the taking of marine mammals for that year, as
long as the sonar use was consistent with these regulations and the
terms of the LOA. In its LOA application, the Navy must specify where
it will operate SURTASS LFA sonar for that year and take authorization
would be limited to that area. Under the regulations, the total area
that would be available for SURTASS LFA sonar operations over the five-
year period is about 70-75 percent of the world's oceans. This in no
way equates to LFA sonar operations affecting even close to 70-75
percent of the world's ocean area at any given time. Each year, based
on its projected operational needs, the Navy will identify for which
particular geographic areas, out of the total available area, it is
requesting take authorization through an LOA. The first authorization
is for only two SURTASS LFA sonar vessels both operating in the Western
Pacific Ocean. Eventually, the Navy plans to have 4 vessels in
operation, but even if
[[Page 46850]]
all 4 vessels operated in 4 different oceans, the area ensonified would
come nowhere close to 70-75 percent of the world's ocean area.
Therefore, SURTASS LFA sonar sound will not simultaneously affect 70-75
percent of the world's oceans. In addition, NMFS has determined that
incidental harassment takings by SURTASS LFA sonar operations during
the effective time period (1 year) of any LOA issued to the Navy
pursuant to these regulations must not exceed 12 percent of any marine
mammal stock.
The sound pressure level (SPL) that is capable of potentially
causing injury to an animal is within approximately 1 km (0.54 nm) of
the ship. For the purposes of analyses using the Acoustic Integration
Model (AIM) and the risk continuum, there is a 50 percent risk of
significant change in a biologically important behavior for a marine
mammal exposed to a received level (RL) of 165 dB RMS. The range from
the SURTASS LFA sonar vessel for this received level, which could cause
behavioral disruption but not injury, could extend to 25 to 65 km (13.5
to 35.1 nm). The received level at the surface along any straight path
away from the ship would not decline logarithmically over distance, as
would be expected if the sound spread by spherical spreading alone. The
reason is that, for CZ propagation, the sound moves in an undulating
path with turning points near the surface and near the bottom, where
sound is refracted either downward (near surface) or upward (near
bottom). Turning points near the surface, termed caustics, occur
approximately every 30 nm (56 km). The received level at the surface
would be high at the caustics but low in between them because most of
the sound energy there would be found at great depth. While the
regulations permit the Navy to seek authorization through an LOA to
take marine mammals while operating SURTASS LFA sonar in many of the
world's oceans and SURTASS LFA sonar signal can be detected at several
hundred miles using sophisticated listening gear, SURTASS LFA sonar's
potential to cause injury or affect behavior is limited to relatively
close to the ship. Thus, the impact of SURTASS LFA sonar is not global
in scope. Moreover, monitoring to ensure that marine mammals are not
injured is not impossible, as the commenter suggests, given the limited
area around the vessel that is ensonified at decibel levels up to 180
dB, and the demonstrated effectiveness of the Navy's tripartite
(visual, acoustic, and HF/M3) monitoring scheme.
Since the SURTASS LFA sonar will not operate in Arctic waters,
there will not be an unmitigable adverse impact on relevant subsistence
uses of marine mammals. That determination is provided later in this
document. NMFS also believes the negligible impact standard has been
met, as described in this final rule.
Comment 2: The Navy is proposing to expand the use of LFA sonar,
both through expansion of use areas geographically throughout the
world's oceans and through doubling the number of LFA sonar array
ships. The Navy is also admitting to the use of CLFA sonar in ``shallow
littoral ocean regions'' and do not discuss the characteristics of CLFA
sonar in the Final SEIS.
Response: While the number of SURTASS LFA sonar vessels will
increase from 2 to 4 vessels over the course of the five-year rule, the
Navy is not increasing the number of SURTASS LFA sonar systems beyond
what was analyzed in the January 2001 Final EIS. That document analyzed
the potential impacts of up to four SURTASS LFA sonar systems. As
stated in the Navy's Record of Decision (ROD) (67 FR 48145, July 23,
2002), the Navy determined that only two of the four systems would be
operational during the timeframe of the 2002-2007 regulations governing
the taking of marine mammals incidental to LFA sonar testing and
training. For that reason, NMFS addressed taking marine mammals
incidental to operation of only two systems under the initial five year
Final Rule in 2002. Installation and deployment of the third and fourth
LFA sonar systems were postponed until after FY 2007. Because of this
delay, the decision in the Navy Record of Decision (ROD) and NMFS' MMPA
determinations covered the employment of only two SURTASS LFA sonar
systems. Therefore, the use of SURTASS LFA sonar, analyzed here, does
not exceed the originally analyzed four systems during the timeframe of
the requested second five year set of MMPA regulations.
In addition, the Navy's proposal to deploy SURTASS LFA sonar in a
number of oceans is not new. The Navy's Final EIS proposed, and NMFS
original Final Rule and regulations addressed, deployment of SURTASS
LFA sonar throughout most of the world's oceans. As stated in the Final
SEIS, these systems will be employed as required for security
operations in the oceanic areas as presented in Figure 1-1 of the Final
EIS. Potential operations could occur in the Pacific, Atlantic, and
Indian Oceans, and the Mediterranean Sea. Large oceanic areas are
restricted from operations, including the Arctic and Antarctic Ocean
areas, as are all offshore areas within 12 nm (22 km) of land, and
OBIAs (Table 2-4 of the SEIS). The limitation of SURTASS LFA operation
to the Western Pacific Ocean was a product of the parties' negotiations
over the Stipulated Permanent Injunction.
Nevertheless, while the number of systems may increase under this
Final Rule and the Navy may seek authorization to use SURTASS LFA sonar
in more places than it could under the terms of the permanent
injunction, the maximum permissible impact to any particular species or
stock remains the same, since the Navy's overall use of SURTASS LFA
sonar can have no more than a negligible impact on marine mammal
species and stocks. Consistent with its findings in the original rule,
NMFS has determined that takings by SURTASS LFA sonar operations during
the effective time period (1 year) of any LOA issued to the Navy
pursuant to these regulations must not exceed 12 percent of any marine
mammal stock.
As stated in the Final SEIS Subchapter 1.2.3 and 2.1, compact LFA
sonar (CLFA sonar) sonar is an upgrade and modification to the SURTASS
LFA sonar system necessary to install and operate on the smaller
VICTORIOUS Class T-AGOS 19 Class ocean surveillance ships. The
operational characteristics of the active system components installed,
or to be installed, on the R/V Cory Chouest, USNS IMPECCABLE, and
VICTORIOUS Class vessels are provided in Final SEIS Subchapter 2.1.1.
The characteristics of LFA sonar and the upgrade and modifications for
the T-AGOS 19 installations are essentially the same. The frequency
requirements for the CLFA to be installed onboard the VICTORIOUS Class
(T-AGOS 19 Class) vessels are within the 100 to 500 Hz range for LFA
sonar and the transmit array also consists of 18 transducers with a
similar source level.
Subchapter 1.1.3 of the Final SEIS provides a definition of the
term ``littoral'' as used by the U.S. Navy and explains the ways in
which the use of the term as a tactical designation differs from its
use as a geographic term. The littoral operating environment does not
necessarily include or exclude any waters because of depth; it can
include both deep and shallow water. However, under any of the
alternatives analyzed in the Final SEIS, LFA sonar would not operate
inside of 12 nm (22 km) from any coastline. The use of SURTASS LFA
sonar in coastal environments was discussed in Response to Comments
(RTCs) 1-1.4 and 3-2.8 in the Final EIS.
[[Page 46851]]
Comment 3: With regard to noise-producing activities, NMFS must
describe source levels, frequency ranges, duty cycles, and other
technical parameters relevant to determining the potential impacts of
an MMPA authorization.
Response: The NMFS action is the issuance of regulations and LOAs
to the Navy for taking marine mammals incidental to SURTASS LFA sonar
operations and determining whether SURTASS LFA sonar is having a
negligible impact on affected marine mammal species and stocks, not
whether LFA sonar operations and other noise producing activities are
having a negligible impact on affected species and stocks of marine
mammals (and species/stocks not affected by LFA sonar, but potentially
by other noise-producing activities). In that regard, all technical
parameters relevant to the impact analysis, including those listed by
the commenter, were provided in the project descriptions for SURTASS
LFA sonar in both the Final EIS (DON, 2001) Subchapters 2.1.1 and
2.3.2.2 and in RTCs 2-1.1 and 2-1.2a; and in the Final SEIS Subchapter
2.1.1.
Comment 4: There are at least five Navy SWATH vessels already built
and outfitted with operational LFA sonars.
Response: Four VICTORIOUS class Ocean Surveillance ships were built
between 1991 and 1993. As stated in the SEIS Subchapter 2.1, there are
no LFA sonar systems deployed on these vessels at this time. The
projected LFA sonar/CLFA sonar system availabilities are shown in the
Final SEIS Figure 2-2, which includes future installations onboard the
VICTORIOUS Class vessels.
Comment 5: It is only a matter of time before many other
industrialized nations follow suit and the oceans become a cacophony of
LFA sonar systems using loud noise to try and find each other in an
increasingly loud environment. The U.S. should re-examine this ``need''
and come up with a better way to find these quiet submarines.
Response: This comment is beyond the scope of this rulemaking. As
explained in the Final EIS, subchapter 1.2.1, the Navy has considered
other alternatives and determined that SURTASS LFA sonar best addresses
its need for reliable long-range detection of potentially hostile quiet
submarines.
Comment 6: At peak power, the Navy's LFA sonar system sends out
pulses of sound underwater at least the equivalent of standing five
feet away from the Saturn rocket on liftoff.
Response: While an accurate source level of the Saturn V is not
known, the comparison of this, or any other rocket, to LFA sonar is
inappropriate. The sound generated by a Saturn V rocket, or any rocket
in general, is broadband and generates a different frequency spectrum
than that of LFA sonar, and travels in a significantly different
transmission pattern. The Saturn C 1 rocket (a predecessor to the
Saturn I rocket, which had about 1,600,000 lbs of thrust) was projected
to have produced acoustic levels as high as 205 dB (in air) from a
distance of 305 meters. Some sources suggest that the sound levels
produced by the Saturn V (during the launch of Apollo 15, the first
stage of the Saturn V generated 7,823,000 lbs of liftoff thrust) may
have been as high as 220 dB (in air) (Benson and Faherty, 1978). As
sound is perceived differently underwater than it is in air, sound
propagation and transmission losses in each case are subject to
differing factors, including terrain, wind, and air temperature, and in
the case of LFA, water salinity, temperature and depth. Furthermore,
sound levels are typically provided with a reference level, which
depends on whether the sound is in air (reference of 20 microPascals)
or water (reference of 1 microPascal). Despite it being inappropriate
to compare a sound level in air with that in water (or vice versa),
some simplified conversion or correction factors are available to
provide a very generic comparison. Therefore, when corrected to the
equivalent sound levels in water (based on pressure and impedance
differences of the two media), the above acoustic levels of 205 dB in
air and 220 dB in air would be approximately 266.5 and 281.5 dB in
water, respectively (Please see Final EIS Appendix B, Subchapter
B.3.2). These sound levels are 100 to 10,000 times louder than the LFA
sonar source.
Comment 7: NMFS should require that the U.S. Navy avoid or
eliminate triangulation of sonar whether they are doing exercises with
other U.S. Navy ships or with those from other nations.
Response: Triangulation is only necessary for passive acoustics.
Triangulation is not necessary for active acoustics because it gives
the operator range and bearing. However, the focus of the comment seems
to be on the use of multiple LFA sonar ships, which is discussed in the
Final SEIS, (Subchapters 4.4.4 and 4.6.1.2) and in the Final EIS
(Subchapter 4.2.7.4). The Final EIS states that the vast majority of
operations will involve only one ship. This is due to the limited
number of ships of SURTASS LFA sonar systems planned to be built and
the limited operational conditions that could warrant the use of two
sources in proximity to each other. The remote possibility exists that
operational requirements or training exercises could require two
sources simultaneously in one geographic region, for example the
Northwest Pacific Ocean where LFA sonar vessels have been operating.
The effect of the presence of two sources transmitting in one area can
be conservatively approximated by doubling the single source potential
effects provided for that site. An example of these effects can be seen
in Table 4-2.13 of the Final EIS. However, even if more than one source
operates in a single geographic area, impacts to marine mammals remain
capped by the negligible impact requirement. To ensure that SURTASS LFA
sonar operations have no more than a negligible impact over five years,
not more than 12 percent of any marine mammal stock may be taken, by
harassment, in a single year, regardless of how many SURTASS LFA sonar
sources are operating in the area.
Comment 8: There are plenty of safe alternatives to active sonar
that the Navy could pursue, such as passive sonar, non-acoustic
sensors, and Integrated Sensory Networks.
Response: The comment is beyond the scope of NMFS' rulemaking for
this action. Non-acoustic alternative underwater detection technologies
are discussed in the Final EIS, Subchapter 1.2.1.
MMPA Concerns
Comment 9: NMFS should consolidate all necessary and relevant
information from the multiple existing sources of information
describing the proposed actions in the proposed rule.
Response: NMFS does not consider it necessary to consolidate all
necessary and relevant information on LFA sonar and its impacts on
marine mammals into the proposed and/or final rules. In the proposed
and final rules, NMFS has continued and updated the information
contained in the preamble to the 2002 final rule. NMFS believes that
this information provides the necessary level of detail needed for it
to make the determinations required under the MMPA and for the public
to review this information. This document also reflects the findings of
the Final EIS, with the data and findings of the Final SEIS. These
documents and others, which are available on the Navy SURTASS LFA sonar
homepage (see ADDRESSES) provide the ``consolidated information'' that
the commenter requested.
Comment 10: The Commission states that any regulations proposing to
issue an incidental taking authorization should include information on
specified geographic locations where sonar is
[[Page 46852]]
expected to be deployed and the species and number of marine mammals
that may be taken in each of those locations.
Response: While the NDAA removed references to the specified
geographical region and small numbers requirements for military
readiness activities, NMFS still needs to know where activities would
take place and the estimated level of take to inform its negligible
impact determination. In order to do so, NMFS considered ``worst-case''
estimates for purposes of the negligible impact determination as well
as an annual 12 percent per-stock ``cap'' for marine mammals regardless
of where and when LFA sonar will be operating (or even how many LFA
sonar systems are in operation annually). This rulemaking also
considered the oceans and areas where LFA sonar may and may not
operate. The rule does not specify the specific location where LFA
sonar will be deployed and the number of marine mammals that may be
taken in those locations because these are determined annually through
various inputs such as mission duration and season of operation [which
are calculated in the annual applications for LOAs].
Comment 11: The Commission recommends the existing annual review
process for LOAs should be expanded to include public review and
comment. The NRDC believes issuance of LOAs without notice and comment
violates MMPA section 101(a)(5)(A) because, it says, each year's
authorization will involve new take and negligible impact analyses and
potentially new exercise areas that are not modeled in the Navy's SEIS.
Response: NMFS does not agree. Under section 101(a)(5)(A), notice
and opportunity for public comment must be afforded before the
Secretary authorizes the incidental take of marine mammals, makes a
negligible impact determination, and issues the required regulations.
NMFS published the proposed regulations on July 9, 2007 (72 FR 37404),
providing the required notice and opportunity for public comment. That
proposed rule contained NMFS' negligible impact determination for the
five-year period and proposed mitigation, monitoring, and reporting
requirements. It also considered the Navy's estimates of take for the
five-year rule period. Section 101(a)(5)(A) of the MMPA does not
require the regulations to specify the number of marine mammals that
may be taken, only the permissible methods of taking and means of
effecting the least practicable adverse impact.
As stated in the proposed rule and the Navy's Final EIS, estimates
were derived based on modeling sites, since it was not practical to
model all areas where the system might be operated. Final EIS p. 4.2-1.
These sites represented the upper bound of impacts expected from
operation of SURTASS LFA sonar. Final EIS p. 4.2-3; see Final EIS
tables 4.2-1, 4.2-4, 4.2-10, 4.2-11, and 4.2-12. If LFA sonar
operations occur in a non-modeled area, the take estimates would most
likely be less than those obtained from the most similar site that was
modeled. Final EIS p. 4.2-3. As stated in the SEIS, the assumptions of
the Final EIS are still valid and have been incorporated by reference
into the SEIS p. 4-39, 40. Moreover there are no new data that
contradict the assumptions or conclusions made in subchapter 4.2 of the
FEIS. Thus, it was not necessary to reanalyze potential acoustic
impacts in the SEIS.
The risk assessment for each planned mission site for each vessel
is performed annually and is part of the Navy's annual mission
intention (LOA application) letter. In its annual LOA applications, the
Navy must project where it intends to operate during the period of the
annual LOAs and provide NMFS with reasonable and realistic risk
estimates of the marine mammal stocks in the proposed areas of
operations. This process utilizes the best available data and is
detailed in the SEIS including a case study. SEIS pp. 4-37 to 4-51.
During the initial steps of the risk analysis process, if the take
estimates exceed those required under the regulations (including the
annual 12 percent per-stock cap), than the mission areas are changed or
refined and the analysis is reinitiated. After receipt of an LOA
application, NMFS reviews the activity (and previous annual reports) to
ensure it remains within the parameters of the rule and the negligible
impact assessment.
NMFS' general implementing regulations for section 101(a)(5)(A) of
the MMPA, which have been in effect since 1982 and which governed the
last rulemaking for SURTASS LFA sonar incidental take, set up the
framework under which NMFS issues LOAs that an applicant must obtain
before any incidental take is authorized. 50 CFR 216.106(a). The
purpose of the requirement for obtaining LOAs is to ensure the
authorized taking will be consistent with the original findings. See 47
FR 21248, 21251 (May 18, 1982). Therefore, issuance of an LOA is based
on a determination that the level of taking will be consistent with the
findings made for the total taking allowable under the specific
regulations for the specified activity. 50 CFR 216.106(b). The
reporting requirements under these specific SURTASS LFA sonar
regulations and LOAs require the Navy to provide both quarterly and
annual reports to NMFS. In these reports, the Navy must provide
estimated percentages of marine mammal species/stocks potentially
affected for each quarter and annually. NMFS' general implementing
regulations do not require the agency to provide notice and comment for
LOAs. However, if NMFS were to obtain information that calls into
question the validity of its determinations in this rule, the agency
could withdraw or suspend authorization to take marine mammals if the
Secretary, through the Assistant Administrator for Fisheries, finds,
after notice and opportunity for public comment, that the regulations
are not being substantially complied with, or the taking allowed
pursuant to the regulations is having or may have more than a
negligible impact on marine mammal species or stocks. 50 CFR
216.106(e). The requirement for notice and comment does not apply if an
emergency exists that poses a significant risk to the wellbeing of the
species or stocks of marine mammals concerned. 50 CFR 216.106(f).
Comment 12: The Commission states that NMFS should address the
requirement of the NDAA that personnel safety, practicality of
implementation, and impact on the effectiveness of the military
readiness activity be considered in making a ``least practicable
adverse impact'' determination in the proposed rulemaking.
Response: NMFS agrees with the Commission and added a discussion of
the NDAA in the proposed and final rules.
Comment 13: The NRDC states the Navy fails to present evidence of
negligible impact. Agencies must make every attempt to obtain and
disclose data necessary to their analysis. This is important when the
program's impacts depend on newly emerging data. The Navy fails to take
account of significant new information that has emerged since January
2001 concerning marine mammal thresholds of injury, hearing loss, and
significant behavioral change.
Response: NMFS believes the MMPA requires a determination of
negligible impact to be based on the best available data. NMFS believes
the best available data were used in the Final SEIS, NMFS' 2002 final
rule, the Navy 2006 MMPA application and this final rule, to estimate
the potential impacts on the environment. Information that the
commenter (and others) believe
[[Page 46853]]
contradict this determination by NMFS is addressed throughout this
document.
Comment 14: A number of commenters were of the opinion that a 15-
day comment period for the proposed rule is too short to review the
material and not in compliance with the Administrative Procedure Act
(APA).
Response: The 15-day comment period on the proposed rule provided
an adquate opportunity for public comment. In addition to the comment
period on the proposed rule, members of the public had a 30-day public
comment period on the Navy's application for renewal of NMFS'
regulations (71 FR 56965, September 28, 2006) and a 92-day public
comment period (including three public hearings) for the Navy's Draft
SEIS on SURTASS LFA sonar (which contains much of the underlying
analysis for this proposed rule, affording significant opportunity for
public participation). In addition, the proposed rule is substantially
similar to the 2002-2007 rule, which underwent a 75-day public comment
period, including public hearings in Los Angeles, CA, Honolulu, HI, and
Silver Spring, MD. There have been no significant scientific
advancements or other developments since the previous rule that would
necessitate a longer period for public comment.
Comment 15: It is well-established that mid-frequency (MF) sonar
negatively impacts marine mammals, even resulting in fatalities, with
the U.S. Navy having admitted direct responsibility for past beachings.
The effects of LF sonar appear to be less understood at this time, but
the enormous range of ocean impacted by sonar makes it incumbent upon
us to fully understand its effects before authorizing its widescale
use. The Precautionary Principle should be applied before issuing a
permit.
Response: NMFS used conservative assumptions for identifying and
analyzing potential impacts to the environment, including marine
mammals. SURTASS LFA sonar has been operating under NMFS regulations
for the last five years without any reports of Level A harassment. The
evidence to date, including recent scientific reports, supports the
conclusion that operation of the U.S. Navy's LFA sonar does not result
in marine mammal strandings. For further information on strandings and
MF sonar, please see comments 8, 32, 33, 47, and 49 for further
analyses on strandings.
Comment 16: I request a moratorium on any use of this technology in
the oceans, at the levels currently used, until further tests are
conducted on the foundational species in the food chain of the marine
environment.
Response: Research using LFA sonar technology has been conducted on
several species in the food chain, including whales (blue, fin, grey,
and humpback whales) and on fish (catfish, a hearing specialist, and
trout; reference species for salmon and a hearing generalist). This
research is discussed later in this document (see Research Concerns).
NMFS believes the data are sufficient to go forward, recognizing that
more research would be valuable.
Marine Mammal Impact Concerns
Comment 17: The NRDC states that the Navy sets its threshold for
hearing loss or ``threshold shift'' at 180 dB re: 1 microPa (RMS) for a
single 100-second ``ping'' of exposure. The analysis is based on data
from humans and other terrestrial mammals and relies on a limited set
of data on marine mammals. The Navy has established a sliding scale for
behavioral impacts. The Final SEIS fails to incorporate several recent
studies on the effects of low-frequency sound on various marine mammal
species. Also, the Navy's standard fails to take proper account of
chronic impacts, from behavioral changes as well as from certain non-
auditory physiological impacts such as stress. The Final SEIS and MMPA
application disregard recent evidence indicated the potential for
masking to interfere with long-distance mating behavior in mysticetes.
The Navy standard is out of step with how the potential for behavioral
impacts has been assessed in other contexts. Last, the Navy does not
consider the impact that behavioral changes in species such as fish may
have on marine mammals foraging.
Response: NMFS believes that the latest information on impacts of
underwater sounds on marine mammals and fish is contained in the Navy's
Draft and Final SEIS, and summarized in the Navy's application. NMFS
addresses the masking issue in comment 19 and elsewhere in this
document.
As stated in the Final EIS, the 180-dB criterion for the purpose of
SURTASS LFA sonar analysis is that all marine animals exposed to
received levels (RLs) greater than 180-dB rms are evaluated as if they
are injured. In its 2002 Final Rule for SURTASS LFA sonar, NMFS stated
that temporary threshold shift (TTS) is not an injury. Since the
boundary line between TTS and permanent threshold shift (PTS) is
neither clear, definitive, nor predictable for marine mammals, NMFS has
adopted (as a conservative estimate) 20 dB of TTS to define the onset
of PTS (i.e., a temporary shift of 20 dB in hearing threshold) (67 FR
46711, July 16, 2002). As noted in Schlundt et al. (2000), bottlenose
dolphins and belugas exposed to 1-sec signals at 400 Hz did not exhibit
TTS after exposures to maximum RLs of 193-dB sound exposure level
(SEL)) (which would be equivalent to a received level of 193 dB re: 1
microPascal (RMS) since the duration is 1-sec). The point must be made
that while dolphins and belugas responses at 400 Hz are valid for those
species, these results probably do not generalize to large whales
(e.g., baleen whales).
In the Schlundt et al. (2000) research, dolphins and belugas did
not have TTS in response to 400 Hz at RLs of 193 dB SEL, but they did
have TTS in response to higher frequencies (where they are more
sensitive) at the same level. It is reasonable to assume that the TTS
threshold value from odontocetes at their frequency of highest
sensitivity is applicable to larger animals and lower frequencies that
are in the range of their best hearing sensitivity. This extrapolation
is based on the fundamental similarity of cochlear structure between
odontocetes and mysticetes. As a result, if it were assumed that 193 dB
SEL was the onset of TTS (a conservative assumption because TTS was not
observed at an RL of 193 dB SEL), then onset of PTS would be 20 dB
above that, at 213 dB RL (SEL). This number is based on a signal of one
second in duration. Using a 10 Log (T/Ti) where Ti is 1 second, then
for a maximum 100-sec LFA sonar signal, a 20-dB adjustment must be
made, meaning that the onset of PTS would be 193 dB RL (SEL). This
value is above the conservative LFA sonar criterion of 180 dB for
injury. A more detailed discussion is provided in the Final EIS RTCs 4-
6.13 and 4-6.38 and the 2002 Final Rule RTCs MMIC8, MMIC9, SIC40,
SIC58, and SIC59.
In addition, recent data on critical ratios (CRs) in pinnipeds is
discussed in the Final SEIS Subchapter 4.3.5. A CR is the difference
between sound level for a barely audible tone and the spectrum level of
background noise at nearby frequencies (Richardson et al., 1995). These
data indicate that the CRs for pinnipeds are lower in magnitude than
for terrestrial animals (Southall et al. 2003). Southall et al. (2003),
in describing their CR results, state that ``It is reasonable to
speculate that acoustic signal production and reception in typically
noisy marine environments have led to selection for enhanced ability to
detect signals in noise.'' Therefore these new CR data indicate that
pinnipeds may be pre-adapted for detecting biologically important
signals in high noise environments.
[[Page 46854]]
Furthermore, the lower critical bandwidths of the pinniped auditory
filters has the effect of decreasing the probability of masking of
signals by noise at a different frequency (Southall et al., 2000).
Nevertheless, NMFS believes pinnipeds remain as susceptible as any
species to masking of signals by noise in the same frequency band.
The Final SEIS also considered recent studies on LF sound and
injury. In regard to injury, the issue of resonance is addressed in the
Final SEIS (RTC 2.5.2). The analysis by the Navy (Cudahy and Ellison,
2002), reports on two workshops on acoustic impacts (DOC, 2002: Cox, et
al. 2006), and the National Research Council (NRC) Ocean Studies Board
(NRC, 2003) support the conclusion that resonance from LFA sonar
operations is not a ``reasonably foreseeable'' impact. Cox et al.
(2006) stated that gas-bubble disease, induced in supersaturated
tissues by a behavioral response to acoustic exposure, is a plausible
pathologic mechanism for the morbidity and mortality seen in cetaceans
associated with MF sonar exposure. They also stated that it is
premature to judge acoustically mediated bubble growth as a potential
mechanism and recommended further studies to investigate the
possibility.
The NRC Report (2003) discusses acoustically-induced stress in
marine mammals. The NRC stated that sounds resulting from one-time
exposure are less likely to have population-level effects than sounds
that animals are exposed to repeatedly over extended periods of time.
The NRC also cited controlled laboratory investigations of the response
of cetaceans to noise that have shown cardiac responses (Miksis et al.,
2001 IN: NRC, 2003) but have not shown any evidence of physiological
effects in the blood chemistry parameters measured. Beluga whales
exposed for 30 minutes to 134-153 dB received level (RL) playbacks of
noise with a synthesized spectrum matching that of a semisubmersible
oil platform (Thomas et al., 1990b IN: NRC, 2003) showed no short-term
behavioral responses and no changes in standard blood chemistry
parameters or in catecholamines. Preliminary results from exposure of a
beluga whale and bottlenose dolphin to a seismic watergun with peak
pressure of 226 dB source level (SL) showed no changes in
catecholamines, neuroendocrine hormones, serum chemistries, lymphoid
cell subsets, or immune function (Romano et al., 2001 IN: NRC, 2003).
The NRC Report (2003) also stated that although techniques are
being developed to identify indicators of stress in natural
populations, determining the contribution of noise exposure to those
stress indicators will be very difficult, but important, to pursue in
the future when the techniques are fully refined. There are scientific
data gaps regarding the potential for LFA sonar to cause stress in
marine animals. Even though an animal's exposure to LFA sonar may be
more than one time, the intermittent nature of the LFA sonar signal,
its low duty cycle, and the fact that both the vessel and animal are
moving, means that there is a very small chance that LFA sonar exposure
for individual animals and stocks would be repeated over extended
periods of time, such as those caused by shipping noise. There is
sufficient information available to permit analysis and decision
making. Therefore, impacts from stress are not a reasonably foreseeable
significant adverse impact on marine mammals from exposure to LFA
sonar.
In studying potential alerting stimuli for North Atlantic right
whales, Nowacek et al. (2003) found that underwater sounds with an
acoustic structure similar to their alert stimulus at RLs of 133-148 dB
are likely to disrupt feeding behavior for the duration of the sound
exposure, with return to normal behavior within minutes of when the
sound was turned off. Their results are consistent with those of the
LFS Scientific Research Program (SRP), which exposed baleen whales to
RLs ranging from 120 to 155 dB, detecting only minor, short-term
behavioral responses (please see Final EIS, Subchapter 4.2.4.3 for more
information). The LFA sonar risk function is based on the LFS SRP
results.
Concern that the LFA sonar signal may cause right whales to surface
and thus be more vulnerable to ship strikes is not well founded because
the vessels only move at about 5.6 km/hr (3 knots) (significantly lower
than normal ship speeds) and LFA sonar mitigation measures will detect
any large whales well before they enter the LFA sonar zone, at which
time LFA sonar operations would be suspended.
Comment 18: A number of incidents of whales becoming stranded and
dying have occurred around the world linked with the use of very loud
military sonars. To date, none of the many incidents involve LFA sonar,
although (1) LFA sonar has not been used in close proximity to whale
populations and (2) the Navy continues to deny that any military sonar
impacts marine life. EII believes LFA sonar may have more lethal impact
over longer distances due to the nature of low frequency sound
transmission underwater. The Draft SEIS claims that the association
between marine mammal stranding events and military sonar is an issue
of ``public perception'' and specifically that ``[a]lthough much of the
public have the impression that military sonar usage is a principle
cause of marine mammal strandings, the facts that are available
indicate otherwise.'' While this might be true for mass stranding
events of a non-anthropogenic origin, it is a grossly misleading
statement. The Navy ignores the scientific record.
Response: Data indicate that the area in which LFA sonar has been
operating (Northwestern Pacific Ocean) has relatively abundant
populations of marine mammals, as presented in the SEIS as shown in
Tables 4.4-2 to 4.4-10. During the LFS SRP in 1997 and 1998, LFA sonar
sources were operated in proximity to marine mammals with only minor
behavioral effects. As detailed in SEIS RTC 4.3.1 and later in this
document, LFA sonar is not known to have caused any marine mammal
strandings or injuries.
The ``public perception'' referred to in the Draft SEIS (p. 4-55)
was one that views LFA sonar the same as any other sonar. The intent of
the statement was that there is a public perception that the effects of
LFA sonar are the same as any other naval, or loud, sonars. As noted in
the discussion in the Final SEIS RTC 4.3.1, the potential for impacts
from LFA sonar differs from that of mid-frequency active sonar. The
best available scientific evidence to date does not indicate that LFA
sonar has the potential to cause strandings based on analyses of
existing strandings (ICES, 2005; Cox et al., 2006). This paragraph was
rewritten in the Final SEIS based on the latest available scientific
data (see SEIS RTC 4.4.13).
Comment 19: Given the relatively long duration of SURTASS LFA sonar
``pings'' masking may be more of an issue than it is with impulsive
noise sources. While the average signal length is 60 seconds--which is
a very long time--for an extremely loud noise each can be up to 90
seconds long and can occur as often as every six minutes. This also
does not take into account reverberation which can significantly
increase the duty cycles and could result in a near continuous signal.
Even temporary masking can be significant as it can compromise an
animal's ability to avoid predators, communicate, track and catch food,
and avoid dangerous environments such as areas of high intensity noise.
Response: The masking effects of the SURTASS LFA sonar signal are
expected to be limited for a number of
[[Page 46855]]
reasons. First, the frequency range (bandwidth) of the system is
limited to about 30 Hz, and the instantaneous bandwidth at any given
time of the signal is small, on the order of 10 Hz. Second, the average
duty cycle is always less than 20 percent and based on past LFA sonar
operational parameters (2003 to 2007) is nominally 7.5 to 10 percent,
as stated in Chapter 2 of the Final SEIS. Also, given the average
maximum pulse length (60 seconds), and the fact that the signals vary
and do not remain at a single frequency for more than 10 seconds,
SURTASS LFA sonar is not likely to cause significant masking. An
analysis of marine mammal hearing and masking are in Subchapter 4.6.1.2
of the Final SEIS. In other words, the LFA sonar transmissions are
coherent, narrow bandwidth signals of 6 to 100 seconds in length
followed by a quiet period of 6 to 15 minutes. Therefore, the effect of
masking will be limited because animals that use this frequency range
typically use broader bandwidth signals. As a result, the chances of an
LFA sonar sound actually overlapping whale calls at levels that would
interfere with their detection and recognition would be extremely low.
It is also unlikely that reverberation will significantly increase
the duty cycles and result in a continuous signal. As a general rule,
reverberation ``dies off'' or decreases with distance from the source
as an exponent of time after sound transmission. However, this is not
instantaneous and, depending on propagation and ocean boundary
conditions, reverberation can linger in an area for seconds or minutes
after a sound transmission, but at greatly reduced SPLs until it fades
into background noise. In special cases (i.e., locations with the
correct bathymetry, propagation conditions and signal repetition
rates), the reverberation may not completely die off before the next
transmission. Generally, however, the reverberation levels several
seconds after transmission are so much less than the original signal,
(i.e., approaching ambient noise levels) that they do not ``add to the
duty cycle.'' LFA sonar signals have sufficient time to significantly
decrease to levels much less than 120 dB in the vicinity of the source,
prior to the transmission of the next signal. Additionally,
reverberation away from the source's location starts at an even lower
level than near the source and generally decreases faster than in
proximity of the source, so it is always less than near the source (see
Final SEIS comment 4.3.39).
Comment 20: The Draft SEIS sets a threshold SPL of 145 dB for
diving and recreational sites, which is an attempt to be precautionary
to humans. This is over 1,000 times less intense than the threshold set
for marine mammals. It is irrational to assume that marine mammals are
less sensitive to sound in water than humans are. It would make far
better sense to adopt a 145 dB as the threshold for all animals,
including humans. Human exposure guidelines ``were established based on
psychological aversion testing,'' exposure limits for cetaceans are
based on avoiding only physiological injury (TTS) or the most dramatic
behavioral responses. What basis justifies providing more protection to
humans engaging in recreational diving than to native inhabitants of
the sea?
Response: These values represent different criteria: psychological
aversion (a behavioral reaction) from direct measurements using human
divers (Technical Report 3 of the Final EIS), and the exposure
level at or above an RL of 180 dB, for which all marine mammals are
evaluated as if they are injured (Final EIS Subchapter 1.4). However,
humans are performing in a foreign medium compared to marine mammals.
This suggests that the risk to marine mammals for a psychological
response would be less than for humans. Furthermore, data cited in the
Final EIS suggest that when operating in the presence of a biological
imperative such as feeding, migrating or mating, such sound levels are
insufficient to make the marine mammal discontinue their behavior
(Technical Report 1 LFS SRP). Behavioral responses for marine
mammals utilizing the risk continuum (see Final EIS Subchapter 4.2.3)
demonstrate the potential for significant biologically important
behavioral reactions from RLs from 120 to 179 dB, but with fewer
significant behavioral responses at levels around 145 dB. Therefore,
NMFS believes the 145-dB criterion for divers is consistent with the
estimates of behavioral reactions to marine mammals, but at this time,
it is unnecessary to consider this SPL as being warranted for marine
mammals since the LFS SRP indicated that there were no significant
behavioral reactions at these low levels and no indication that marine
mammals might be seriously injured or killed by LFA sonar.
Comment 21: The Draft SEIS minimizes impacts by emphasizing the
small number of SURTASS LFA sonar systems to be employed and the narrow
bandwidth of the active sonar signal. It is the intensity and
pervasiveness of the SURTASS LFA sonar systems that is important in the
discussion of impacts. The fact that there is more than one system
merely compounds the problem. To declare that the low number and narrow
bandwidth are mitigation measures is ludicrous.
Response: Even though the source level of SURTASS LFA sonar is
similar in intensity to many anthropogenic underwater sound sources,
such as air gun arrays and other military sonars, there are significant
differences in their operational characteristics. Table 1 illustrates
these differences. Also, please see the Final SEIS RTC 4.3.1 for more
information.
In a recent analysis for the Policy on Sound and Marine Mammals: An
International Workshop sponsored by the Marine Mammal Commission (U.S.)
and the Joint Nature Conservation Committee (UK) in 2004, Dr. John
Hildebrand provided a comparison of anthropogenic underwater sound
sources by their annual energy output. Dr. Hildebrand reported that the
most energetic regularly operated sound sources are seismic air gun
arrays from approximately 90 vessels with typically 12 to 48 individual
guns per array, firing about every 10 seconds. There are approximately
11,000 super tankers worldwide, each operating 300 days per year,
producing constant LF noise at source levels of 198 dB (SEL)
(Hildebrand, 2005). Conversely, LFA sonar signals are transmitted for a
maximum of 432 hours (18 days) per vessel per year. The signal length
is between 6 to 100 seconds with 6 to 15 minutes between transmissions
with individual elements source levels of 215 dB. Therefore, LFA sonar
contributes less acoustic energy to the oceans than other sources. For
more detailed discussions on Hildebrand's (2004) analysis, please see
SEIS RTCs 4.6.4 and 4.6.5.
Even though LFA sonar signals are long range, LFA sonar cannot be
considered to be pervasive (pervasive means to permeate or be present
throughout) because of the nominal 7.5 to 10 percent duty cycle,
meaning that during any given mission LFA sonar is not transmitting 90
to 92.5 percent of the time. Moreover, impacts to marine mammals
species and stocks must remain negligible and, in that regard, taking
by behavioral harassment may not exceed 12 percent of a marine mammal
stock in any given year.
Comment 22: Throughout the document, the Draft SEIS claims that
impacts will be negligible because there is no contradictory data. The
absence of evidence does not equate to evidence of absence. In the
absence of data, precaution should prevail.
Response: The absence of evidence regarding effects of these
actions on marine mammals does not mean we can assume they have not
occurred, and will
[[Page 46856]]
not occur in the future. However, we are not relying solely on absence
of evidence. The agencies used the best information currently available
to analyze the impacts to marine mammals as shown in this document and
in more detail in Chapter 4.0 of the Final SEIS. Some of the new
information used by NMFS to make its determinations under the MMPA are
discussed and summarized in this Federal Register notice. That evidence
includes a 5-year track record of using SURTASS LFA in an area rich in
marine life without incident. In addition, NMFS requires the Navy to
conduct mitigation and monitoring, including research to further
clarify impacts on marine mammals from LFA sonar.
Comment 23: Throughout the Draft SEIS, the Navy states that the
SURTASS LFA sonar ships move in two dimensions, whereas marine animals
move in three dimensions. It uses this logic to state that the amount
of time that an animal would be in the sonar transit beam is very low.
A ship does move in two dimensions, so if ship strikes were the only
concern, then this rationale would work. However, sound propagates in
three dimensions so the logic is flawed.
Response: The Navy has clarified the intent of this statement in
the Final SEIS. The statement now reads: ``[A] Slowly moving ship,
coupled with low system duty cycle, would mean that fish and sea
turtles would spend less time in the LFA sonar mitigation zone (180 dB
sound field); therefore, with a ship speed of less than 5 knots, the
potential for animals being in the sonar transmit beam during the
estimated 7.5 to 10 percent of the time the sonar is actually
transmitting is very low.''
Comment 24: In its discussion of acoustic impacts, the Draft SEIS
is flawed because it centers its entire analysis on a questionable
premise, an SPL threshold of 180 dB RL for marine animal impact.
Response: The SPL threshold of 180 dB RL was only for potential
injury impacts and not for other impacts, such as significant
behavioral modifications. Please see Final SEIS Comment 4.0.1 for more
information.
Comment 25: In its discussion of acoustic impacts the Draft SEIS is
flawed because it chooses to base its entire evaluation of the
potential acoustic impacts to marine mammals on selective data, while
ignoring more timely, widely accepted and peer reviewed science,
including applicability of actual stranding events. In its discussion
of acoustic impacts the Draft SEIS is flawed because it chooses to
dismiss evidence suggesting behavioral reaction to sound can produce
Level ``A'' harassment.
Response: The scientific evidence supporting findings that marine
mammals will not be injured at received levels less than 180 dB by
SURTASS LFA sonar is provided in the Final SEIS (RTCs 4.0.3, 4.3.1, and
4.3.7 through 4.3.15). LFA sonar has not been implicated in any known
marine mammal strandings as discussed elsewhere in this Federal
Register notice and in the Final SEIS RTC 4.4.9 through 4.4.26. NMFS
and the Navy have determined that the potential for injury to marine
mammals by exposure to LFA sonar signals at received levels below 180
dB is unlikely.
Even though there is the potential for the LFA sonar signal to
injure marine mammals at RLs greater than 180 dB, that possibility is
highly unlikely given the reliability of the Navy's tripartite
monitoring scheme and, in particular, the demonstrated effectiveness of
the HF/M3. NMFS does not dismiss the possibility that behavioral
reactions to sound can possibly produce Level A harassment; however,
the best available scientific evidence strongly suggests that this is a
concern primarily for certain species of odontocetes when exposed under
particular conditions to mid-frequency sonar. The results of the LFS-
SRP strongly indicate that the behavioral reactions of baleen whales,
which hear best in the low frequency range, when exposed to SURTASS LFA
sonar are minimal. Although there is no evidence that LF sound can
cause biologically significant behavioral responses in odontocetes, and
several factors including the inability of such species to hear well in
the low frequency range contraindicate such responses, NMFS presumes
that, while unlikely, it has the potential to occur. As a result, the
Navy is presently planning its 2007-2008 field research for deep diving
marine mammal behavioral response studies in an attempt to
scientifically address this issue for LFA sonar, MFA, and seismic
sources. This is discussed later in this document (see Research).
Comment 26: The ``Determination of Risk Function,'' suggests that
there is a continuum of severity of behavioral responses to SURTASS LFA
sonar signals, ranging from 95 percent of those exposed to 180 dB
having significant (if temporary) change in biologically important
behavior, down to the first evidence of ``significant'' change
occurring at 119 dB. If SURTASS LFA sonar signals are arriving at the
22-km (12-nm) offshore line at a level of just under 180 dB, then it is
likely that near shore areas will be experiencing sound levels
significantly above 120 dB. It would be helpful in making more
biologically sound decisions if NMFS or the Navy clarified the radius
within which received levels could be expected to be 120 dB, 145 dB,
and/or 160 dB. The AEI suggests these radii not because these numbers
have special or well defined significance, but to suggest that such
information would give regulators and researchers a better sense of the
likely zones of influence within which behavioral responses might be
expected to increase or decrease in severity. At the least, AEI would
suggest a lower allowable threshold of received levels at 22 km from
shore, to protect these biologically important areas from behavioral
disruptions in response to moderate noise levels.
Response: The AEI is correct that the risk continuum provides a
method to determine effects from sound exposure based on the fact that
various animals will react differently to LFA sonar signals. The data
from the LFS SRP support a linear dose response function, also known as
the LFA sonar risk continuum, for sound exposure and the potential for
significant behavioral effects. This risk continuum was an integral
part of the analysis in the Final EIS and 2002 Final Rule of the
potential for SURTASS LFA sonar operations to cause significant
behavioral effects in marine mammals. The ranges to RL isopleths and
the ocean volumes they would encompass vary under different
oceanographic conditions and were analyzed in the Final EIS. Detailed
results of these analyses are presented in Subchapter 4.2 of the Final
EIS and in Technical Report 2 (Acoustic Modeling Results).
Figures B-1 through B-31 of TR 2 provide the parabolic equation (PE)
transmission loss (TL) plots for each of the 31 sites. These plots
provide TL as a function of depth and range from the source. The
analysis determined that there is the potential for marine mammals to
be affected by SURTASS LFA sonar.
However, an analysis summarized in Final SEIS Subchapter 4.7.6
indicates that, while increasing the coastal standoff range from 12 nm
(22 km) to 25 nm (46 km) decreases exposure to higher RLs for marine
animals closest to the shore (shelf species), it does so at the expense
of increasing exposure levels for shelf break species and pelagic
species.
As a result of the Final EIS analysis, mitigation protocols were
developed to prevent injury to marine mammals. Mitigation protocols
were not deemed necessary or practical for other than Level A
harassment (injury) takes. Results from operations under the initial
[[Page 46857]]
5-year set of regulations for LFA sonar are presented in the SURTASS
LFA sonar Final Comprehensive Report (see ADDRESSES for availability)
and indicate that the Level B harassment take numbers for individual
stocks of marine mammals in the areas of operations are within the
values from the Final EIS analyses.
Comment 27: The association between anthropogenic ocean noise and
its impacts on marine mammals is well documented although there is
still scientific uncertainty over the actual causal mechanisms of
impacts. It is generally accepted that impacts can range from altered
behavior through temporary injury to mortality. Altered behavior can
include a startle response and can affect an animal's ability to: feed,
find mates, stay on a migration path, communicate, stay at or return to
a favored feeding area, nurse, care for young, catch prey and escape
predators. Mortality can result directly from exposure to sound or
indirectly as a consequence of altered behavior or temporary injury.
Response: While NMFS agrees with the statement, it cautions that it
does not necessarily mean that all loud anthropogenic sounds will cause
the stated reactions. NMFS details the relationship between events and
LFA sonar throughout this document.
Comment 28: The Draft SEIS states that ``the operation of SURTASS
LFA sonar with monitoring and mitigation will result in no lethal
takes.'' The evidence obtained from actual mortality incidents
associated with anthropogenic noise suggests that the mechanisms by
which animals are impacted by noise are far less straightforward than
the Draft SEIS suggests. There is now increasing evidence that non-
auditory injury or permanent loss of hearing are not the only
mechanisms by which mortality can result from exposure to noise. For
example, an alteration of behavior (Level B) such as a startle response
leading to breaching can result in death whereas a gash injury (Level
A) can heal and have no long term impact. The Draft SEIS should concede
that the knowledge base surrounding the causal mechanisms of marine
mammal impacts is too scant to be so readily compartmentalized.
Response: See responses to Comments 24, 25 and 27. As related to
LFA sonar, the Navy performed extensive research to determine the
potential for LF transmissions to cause significant behavioral effects
in whales (the LFS SRP). There is no indication during these tests that
whales surfaced rapidly or dove prematurely in response to LFA sonar
source transmissions. The mechanisms to cause such events are based on
the theory that MF-naval sonar can cause rapid surfacing and diving,
thus resulting in acoustically mediated bubble growth. Also please see
the discussion in the Final SEIS (RTCs 4.0.3, 4.3.7, and 4.3.12).
Comment 29: The Draft SEIS uses 180-dB RL as the threshold for
impacts to marine animals and persistently reminds the reader that this
is a conservative figure. Field data suggest that this figure is much
too high. In the Bahamas multi species mass stranding incident of 2000
estimates of the average sound exposure level that caused those animals
to strand was around 140 dB re: 1 microPa. The Draft SEIS dismisses the
Bahamas stranding event saying that the hemorrhaging in the stranded
animals could have been caused by factors other than acoustic trauma.
This is not consistent with the actual findings published in the
Interim Report on the event which states ``all evidence points to
acoustic or impulse trauma'' and identifies ``mid-range tactical Navy
sonars operating in the area as the most plausible source of the
acoustic or impulse trauma.''
Response: First, the Bahamas 2000 stranding event did not involve
LFA sonar. Based on the best information available at this time, NMFS
believes LFA sonar operations will not cause injury to marine mammals
at received levels below 180 dB. Second, the commenter's statement
regarding the mid-frequency sonar decibel levels to which the stranded
animals were exposed is incorrect. No one knows to what maximum decibel
level the animals that ultimately stranded were exposed. Estimates were
based on prior near-shore sightings of beaked whales at the locations
where those whales were sighted, but they do not reflect the actual
maximum received decibel levels of the particular animals that
stranded. Third, the Bahamas interim report and further subsequent
analysis of the event indicate that the strandings were likely caused
by mid-frequency sonar in combination with a list of other contributing
factors. The list of contributing factors is generally supported by the
workshop on understanding the impacts of anthropogenic sound on beaked
whales convened by the U.S. Marine Mammal Commission in 2004 (Cox et
al., 2006) and the analysis by D'Spain et al. (2006). Whether or not
surface ducts, one of the listed contributing factors, occurred during
other reported strandings is not relevant to LFA sonar operations. The
LFA sonar signals are initially transmitted substantially below 10 m
(32.8 ft) water depth and are not likely to have signal strength above
180 dB in the surface duct. To ensure a thorough environmental
analysis, however, surface ducting conditions were analyzed in the
Final EIS at a number of the 31 model sites. Therefore, with LFA sonar
mitigation, no marine mammals, in waters either with or without a
surface duct, are expected to be exposed to injurious levels by LFA
sonar signals.
Comment 30: Since the FEIS was completed in January 2001, there
have been at least five mass stranding incidents associated with ocean
noise and several studies and papers related to the range of impacts of
noise on marine mammals. To claim that none of this new data
contradicts the assumptions or conclusions in the FEIS is questionable.
There is more compelling evidence that: (1) The mechanisms by which
animals strand as a result of a noise event are very complex; (2)
different mechanisms can be involved and different impacts can result
depending on the species and the circumstances; (3) the noise
intensities at which animals strand are likely lower than those
previously assumed; and (4) tissue injury is not necessary to cause
animals to strand and die.
Response: The issue is not whether anthropogenic sound causes
marine mammal strandings, but rather does LFA sonar cause marine mammal
strandings. The evidence to date, supported by recent scientific
reports, supports the conclusion that the U.S. Navy's LFA sonar is not
likely to cause marine mammal strandings. However, an ad hoc committee
of international experts under the auspices of the ICES has reviewed
the impacts of sonar on cetaceans and fish. They concluded, ``No
stranding, injury, or major behavioral change has yet been associated
with the exclusive use of low frequency sonar'' (ICES, 2005). This is
further supported by 36 scientists in their recently published paper
which arose from the Marine Mammal Commission workshop on the impacts
of anthropogenic noise on beaked whales (Cox et al., 2006). Therefore,
the statement that there are no new data contradicting the assumptions
or conclusions in the Final EIS and Final SEIS remain correct.
Moreover, five years of SURTASS LFA sonar use without evidence of
strandings, injury, or other major behavioral changes support the
conclusions of the Final OEIS/EIS and the Final Rule 2002. However,
NMFS continues to view this issue seriously and does not dismiss it
simply because a stranding has not been observed. For more detailed
information, please see the Final SEIS
[[Page 46858]]
(RTCs 4.0.3, 4.3.1, 4.3.2, 4.3.7, 4.3.8, 4.3.9, and 4.3.12).
Comment 31: The Draft SEIS mentions only three noise related marine
mammal stranding events under the heading ``Strandings potentially
related to anthropogenic sound.'' There is irrefutable evidence that
anthropogenic sound causes marine mammal strandings. What is not known
with any scientific certainty is the actual causal mechanisms. In
listing only three marine mammal stranding incidents potentially
related to anthropogenic sound, the Draft SEIS is being disingenuous.
Not only are there many more strandings, but when all atypical mass
strandings are tabulated, the overwhelming majority is associated with
naval maneuvers, and likely sonar usage. (The commenter also provided
the table from the ICES (2005) Report of the Ad hoc Group on the Impact
of Sonar on Cetaceans and Fish).
Response: The Navy's intention was to examine three of the more
studied stranding events in which naval sonars were implicated as a
potential cause. This subchapter has been expanded in the Final SEIS
based on stranding event information cited in more recent reports, such
as ICES AGISC Report (ICES, 2005), and reports on the potential causes
presented by ICES (2005), Cox et al. (2006), and D'Spain et al. (2006).
NMFS believes that this revision is adequate as related to the
potential for SURTASS LFA sonar to cause strandings because LFA sonar
was not considered causative in any of these events and, indeed, low
frequency sonar has never been implicated in any stranding, with the
possible exception of the Greece stranding in 1996, during which mid-
frequency sonar was also employed.
Comment 32: The Navy has not reported any marine mammal stranding
incident that has occurred in the vicinity of its activities. The Draft
SEIS claims that SURTASS LFA sonar has not been implicated in any
stranding event. This is not accurate. An LFA sonar system was
implicated in the mass stranding of twelve Cuvier's beaked whales in
1996 in Greece though as the Draft SEIS states, the inner ears were not
examined. This does not mean that LFA sonar use did not cause the
animals to strand. The usage of LFA sonar has also been far more
restricted than mid frequency sonar for which there are more associated
mass stranding events.
Response: The Draft SEIS was correct. SURTASS LFA sonar have never
been implicated in a stranding. While there was a LF component of the
sonar potentially related to the Greek strandings in 1996, only MF
components were implicated in the strandings in the Bahamas in 2000,
Madeira 2002, and Canaries in 2002. This suggests that the LF component
in the Greek strandings was not causative (Cox et al., 2006; ICES,
2005). In its discussion of the Bahamas stranding, Cox et al. (2006)
stated, ``The event raised the question of whether the mid-frequency
component of the sonar in Greece in 1996 was implicated in the
stranding, rather than the low frequency component proposed by Frantzis
(1998).'' The ICES in its ``Report of the Ad Hoc Group on the Impacts
of Sonar on Cetaceans and Fish'' is in agreement with Cox et al. (2006)
stating that the association of MF sonar in the Bahamas, Madeira, and
Canary Island strandings suggest that it was not the LF component in
the NATO sonar that triggered the Greece stranding of 1996, but rather
the MF component (ICES, 2005). The ICES (2005) report also concluded
that no strandings, injury, or major behavioral change have yet to be
associated with the exclusive use of LF sonar.
Since October 14, 2003, SURTASS LFA sonar use has been restricted
under a permanent injunction to limited areas in the western Pacific
Ocean (see Final SEIS, Subchapter 1-2.1, Figures 1-1 and 4-4.2). Since
commencing operations in 2003, the R/V Cory Chouest and USNS IMPECCABLE
have completed 40 missions from January 2003 to August 2006 under the
first four LOAs (DON, 2007). The general areas are known to the public
because they are based on the Court Order, published in the Draft and
Final SEIS, and incorporated into the subsequent NMFS LOAs. The
locations and times of LFA sonar active operations are reported to NMFS
quarterly (classified report) as required in the Final Rule and annual
LOAs. These operations, with mitigation, have produced no known Level A
takes on marine mammals as reported in the Annual Reports (DON, 2003a;
2004a; 2005a; 2006a) and the Final Comprehensive Report (DON, 2007).
Reviews of stranding reports in the LFA sonar operating area showed
that there were a total of 19 strandings reported in Asia (four in
Taiwan, nine throughout the Philippines, two in Thailand, two in
Indonesia, and two in China) (The Cetacean Stranding Database,
accessed: 11/28/2006). None of these strandings were coincident either
temporally or spatially with LFA sonar operations.
Moreover, the Northwestern Pacific Ocean areas where SURTASS LFA
sonar is presently operating are some of the most heavily populated
areas in the world and cannot be considered ``remote.''
As to the possibility of unreported strandings, the NMFS and the
Navy do not consider that this is a very likely scenario for LFA sonar
operations. Even though a visual observer onboard the vessel will be
unable to see an animal that strands on the shoreline due to operations
being greater than 12 nm (22 km) from land, this is not relevant
because LFA sonar is unlikely to cause injury beyond the 180-dB
mitigation zone (normally 1 km (0.5 nm) radius). Level A (injury)
harassments are determined based on actual observations/detections
within the LFA sonar mitigation zone. With passive and active acoustic
detection, the probability of detection within this zone is over 95
percent for a single marine mammal (see Final EIS, Subchapters 2.3.2.2
and 4.2.7.1.). For multiple animals, the value is nearly 100 percent.
The area of the northwestern Pacific Ocean, where LFA sonar vessels are
currently operating, is not a remote area and there are stranding
networks in the region. A review of reported strandings in the area
does not show any correlations to LFA sonar operations either spatially
or temporally (see discussion later in this document on strandings in
Taiwan).
Comment 33: The Draft SEIS states that no Level A harassment
incidents have been reported in the area of usage; however, it does not
relate the effort undertaken to search for such incidents or mention
reports of Level ``B'' harassment incidents.
Response: See Comment 32.
Comment 34: The association between mid frequency sonar usage and
strandings was not realized until decades after its introduction.
Response: NMFS agrees, noting that Balcomb and Claridge (2001)
reported that beaked whale strandings have increased since the use of
MF sonar in the 1960s. However, the association between MF-sonar and
strandings appears limited to a confluence of factors. Stranding
networks weren't active until much later than the 1960's, but have been
active since SURTASS LFA sonar came into use. Certainly, SURTASS LFA
sonar has received great scrutiny with respect to the potential for
strandings and none have been observed.
Comment 35: The Draft SEIS appears to be only concerned about
impacts producing Level A harassment which it claims will be
negligible. The impacts from behavioral alteration to individual
animals are dismissed as inconsequential. Behavioral impacts can not
only produce level A harassment, but impacts to individuals are
[[Page 46859]]
significant especially for endangered populations, and can have
population level consequences no matter what the status of the species.
Response: There are several types of Level B harassment that can
result from anthropogenic sounds. Two types of behavioral effects that
have potential for population level effects are masking and stress.
These will be addressed here. (also see the Final SEIS RTCs 4.0.3 and
4.3.12 in Comment 1, SEIS RTC 4.3.17 in Comment 5, SEIS RTC 4.3.2 in
Comment 6, and SEIS RTC 4.3.33 in Comment 7). Other potential Level B
harassment effects are addressed elsewhere in this rulemaking document.
Also, please see the Biological Opinion issued under section 7 of the
ESA for this action by NMFS (see ESA later in this document).
In regard to masking, the commenter is confusing the avoidance
response of migrating gray whales and bowhead whales with masking.
There was no evidence of masking in any of the research on these two
species. Certainly in the gray whale case, the interpretation by the
scientists who conducted the research was that the whales responded but
responses were not interpreted as having a significant behavioral
impact. Furthermore, a received level of 120 dB for LFA sonar would not
mask the species-specific sounds of any low frequency mysticete,
although under certain, rare circumstances it might interfere with
species recognition. The masking effects of the SURTASS LFA sonar
signal are expected to be limited for a number of reasons. First, the
frequency range (bandwidth) of the system is limited to about 30 Hz,
and the instantaneous bandwidth at any given time of the signal is
small, on the order of 10 Hz. Second, the LFA sonar signal is active
(or on) only about 7.5 percent of the time (i.e., low duty cycle based
on historical LFA sonar operations, but may be on for up to 20 percent
of the time) and limited to periods during actual missions. Therefore,
the effect of masking will be limited because animals that use this
frequency region typically use broader bandwidth signals. As a result,
the chances of an LFA sonar sound actually overlapping whale calls at
levels that would interfere with their detection and recognition would
be extremely low.
Regarding stress, stress can be defined as a threat to homeostasis
(Fair and Becker, 2000) and is frequently measured with changes in
blood chemistry (Thomas et al., 1990; Romano et al., 2004; Smith et
al., 2004a). Thomas et al. (1990) exposed captive belugas to recorded
industrial noise for 30 minutes at a time, with a total exposure of 4.5
hours over 13 days with a source level of 153 dB. Catecholamine blood
levels were checked both before and after noise exposure; however, no
significant differences in blood chemistry were observed. Another
experiment that measured blood chemistry, but also varied the sound
level is described in Romano et al. (2004). In this experiment, a
beluga whale was exposed to varying levels of an impulsive signal
produced by a watergun. The levels of three stress related blood
hormones (norepinephrine, epinephrine and dopamine) were measured after
control, low level sound (171-181 dB SEL) exposure and high level (184-
187 dB SEL) sound exposure. There were no significant differences
between low level sound exposure and control, while the high level
sound exposure did produce elevated levels for all three hormones.
Furthermore, regression analysis demonstrated a linear trend for
increased hormone level with sound level.
Less relevant to marine mammals, but still informative, Smith et
al. (2004a) exposed goldfish (a hearing specialist fish) to continuous
background noise of 160-170 dB RL. There was a ``transient spike'' in
blood cortisol levels within 10 minutes of the onset of noise that was
loud enough to cause TTS. However, this cortisol spike did not persist
and there was no long term physiological stress reaction in the
animals.
These data support a linear dose response function (like the LFA
sonar risk continuum) for sound exposure and the onset of stress, with
only high levels of sound leading to a stress reaction. The
extrapolation of the response thresholds from the Romano et al. (2004)
experiment to the LFA sonar situation is tenuous because of the
differences in the signals, but the relationship between sound level
and stress is supported by several studies. As mentioned elsewhere,
there are some recent data (e.g., Evans, 2003) implicating synergistic
effects from multiple stressors, including noise. Although there are no
data to support synergistic effects, similar impacts might occur with
marine mammals, given the multiple stressors that often occur in their
environment. This indicates to NMFS that while stress in marine animals
could possibly be caused by operation of the LFA sonar source, it is
likely to be constrained to an area much smaller than the zone of
audibility, probably closer in size to the mitigation zone around the
vessel.
Comment 36: The LFS SRP Phase II conducted by the Navy to determine
LFA sonar impacts on migrating whales found that when the source was
located in the whales' migratory path (approximately 1 km (0.54 nm)
from shore), gray whales avoided levels below 150 dB. The SRP showed
negligible avoidance by the whales when the source was located over 2
km (1.1 nm) from shore. From the results of the LFS SRP Phase II, the
Navy concluded no biologically significant response. Perhaps in
actuality more sensitive individuals or mother calf pairings tend to
hug the coast during migration. For some groups, the most sensitive
animals may be crucial to a group's survival as these may be the first
individuals to become aware of predators or of dangerous situations. To
lose sensitive animals or nursing mothers from a group could have
population level consequences.
Response: NMFS believes the characterization of the Navy's
conclusion is out of context. See the Final EIS Subchapter 4.2.4.3.
NMFS does not believe that some whales ``hugged'' the coast of
California during the LFS SRP. For this phase of the SRP, the sound
source was moored offshore of the central California coast, near Point
Buchon. Shore-based observers tracked whales using methods that
provided highly sensitive measures for avoidance responses. These
observers would have sighted whales along the coast line. Also,
observers on the playback vessel also carefully monitored marine
mammals in order to stop broadcasting in case of worrisome behavioral
reactions or if any marine mammals were sighted at close enough range
that the sound level to which they were exposed might exceed the
maximum planned exposure level (155 dB).
The issue of potential calf strandings during the LFS SRP in Hawaii
was addressed in the Final EIS RTC 4 5.25 where it was concluded that
these events were not related to LFA sonar testing. Masking of
communications could potentially affect the mother calf bond; however,
masking effects from the SURTASS LFA sonar signal are extremely
unlikely and are expected to be negligible considering the short duty
cycle and other factors discussed in this document. The rationale for
this is discussed in Final SEIS RTCs 4.3.23 and 4.3.36. Thus, LFA sonar
signals are not expected to disrupt the mother calf bond.
Comment 37: An aversion response can occur many tens of miles from
the source, and father away if it is in the direct path of the beam-
formed or ducted signal.
[[Page 46860]]
Response: Given that the LFA sonar sound source can be detected at
moderate to low levels over large areas of the ocean, the Navy (and
NMFS) had concerns at the initiation of the NEPA process in 1996 that
there was the potential for large percentages of species/stocks to be
exposed; if animals would be disturbed at these moderate-to-low
exposure levels such that they experience a significant change in a
biologically important behavior, then such exposures could potentially
have an impact on rates of reproduction or survival. Knowing that
cetacean responses to LF sound signals needed to be better defined
using controlled experiments, the Navy helped develop and supported the
independent three-year LFS SRP beginning in 1997. The study analyzed
the behavioral responses of whale species that have the greatest
sensitivity to low frequency sounds and thus were believed to be the
most vulnerable, potentially, to LFA sound. This field research program
was designed to address three important behavioral contexts for baleen
whales: (1) Blue and fin whales feeding in the southern California
Bight, (2) gray whales migrating past the central California coast, and
(3) humpback whales breeding off Hawaii. Taken together, the results
from the three phases of the LFS SRP do not support the hypothesis that
most baleen whales exposed to RLs near 140 dB would exhibit disturbance
behavior and avoid the area. These experiments, which exposed baleen
whales to RLs ranging from 120 to about 155 dB, detected only minor,
short-term behavioral responses. Short-term behavioral responses do not
necessarily constitute significant changes in biologically important
behaviors.
These results have been supported by recent, peer-reviewed papers.
Croll et al. (2001a) studied the effects of anthropogenic LF noise
(SURTASS LFA sonar) on the foraging ecology of blue and fin whales off
San Nicolas Island, California. Overall, the whale encounter rates and
diving behavior appeared to be more strongly linked to changes in prey
abundance associated with ocean parameters than to LFA sonar
transmissions. In some cases, whale vocal behavior was significantly
different between experimental and non-experimental periods. However,
these differences were not consistent and did not appear to be related
to LF sound transmissions. At the spatial and temporal scales examined,
Croll et al. (2001a) stated that they found no obvious responses of
whales to a loud, anthropogenic, LF sound.
Both Miller et al. (2000) and Fristrup et al. (2003) published on
the results of tests conducted with male humpback singers off Hawaii in
which they evaluated variation in song length as a function of exposure
to LF sounds. In spite of methodological differences, the results of
both studies indicated that humpback whales slightly increased their
songs in response to LF broadcasts. Fristrup et al. (2003) found that
the fraction of variation in song length that could be attributed to LF
broadcast was low and concluded that the effects of LF broadcast did
not impose a risk of dramatic changes in humpback whale singing
behavior that would have demographic consequences. For more information
please also see SEIS RTC 4.3.30.
Comment 38: SURTASS LFA sonar impacts the vocalizations and other
behavior of humpback whales.
Response: NMFS does not disagree with the potential impacts of LFA
sonar on vocalization and other behavior. The justification for the
conclusion that the potential effects on the stocks of marine mammals
from behavioral changes would be minimal is discussed in the Final SEIS
in RTC 4.3.29. The potential effects of masking are discussed in the
Final SEIS RTCs 4.3.1 and 4.3.23. The Miller et al. (2000) article
``Whale songs lengthen in response to sonar'' concerning observations
of male humpback whales during Phase III of the LFS SRP was addressed
in the Final EIS RTC 4-5.19 and in the NMFS Final Rule RTC SIC16 and
SIC17. Fistrup et al. (2003) used a larger data set from Phase III to
describe song length variability and to explain song length variation
in relation to LF broadcasts. In spite of methodological and sample
size differences, the results of the two analyses were generally in
agreement, and both studies indicated that humpback whales tend to
lengthen their songs in response to LF broadcasts.
Fristrup et al. (2003) provides a detailed picture of short-term
response as compared to behavioral variation observed in the absence of
stimuli. These responses were relatively brief in duration, with all
observed effects occurring within 2 hours of the last LFA sonar source
transmission. It should be noted that these effects were not salient to
the acoustic observers on the scene, but were revealed by careful
statistical analyses (Fistrup et al., 2003). Aside from the delayed
responses, other measures failed to indicate cumulative effects from LF
broadcasts, with song-length response being dependent solely on the
most recently LF transmission, and not the immediate transmission
history. The modeled seasonal factors (changes in surface social
activities) did not show trends that could be plausibly explained by
cumulative exposure. Increases in song length from early morning to
afternoon were the same on days with and without LF transmissions, and
the fraction of variation in song length that could be attributed to LF
broadcast was low. Fistrup et al. (2003) found high levels of natural
variability in humpback song length and interpreted the whales'
responses to LF broadcasts to indicate that exposure to LFA sonar would
not impose a risk of dramatic changes in humpback whale singing
behavior that would have demographic consequences.
Comment 39: It is impossible to comment fully on the Acoustic
Integration Model (AIM), the program used by the Navy to calculate the
system's impacts, because that model has not been released to the
public. Disclosure of the model must occur for public comment to be
meaningful under NEPA and the Administrative Procedure Act (APA) to be
met.
Response: The Acoustic Integration Model (AIM) contains proprietary
programming that prevents its release to the public. As a result, in
response to a different incidental take application (Draft EIS for Gulf
of Mexico Seismic Surveys), AIM recently underwent an independent
scientific review by the NMFS-sponsored Center for Independent Experts
(CIE). The CIE review took place September 25-27, 2006. A report from
that review is publicly available on the NMFS Web site (http://www.nmfs.noaa.gov/pr/permits/incidental.htm
). Additional documentation
can be found on the SURTASS LFA sonar Web site (see ADDRESSES).
Comment 40: Models used by the Navy in its applications for LOAs to
assess its actual work in the Pacific, and in its Final EIS to estimate
impacts in sample coastal areas, in large part assume a fairly even
distribution of marine mammals across a wide area of ocean, failing to
take the possibility that certain animals, like beaked whales and sperm
whales, may be concentrated in particular habitats. Specifically, the
Navy has not conducted research on beaked whale habitat preferences. In
the limited modeling we have seen, the Navy frequently assumes that
populations of marine mammals are relatively unstructured, such that
individual animals are improbably considered part of region-wide,
basin-wide, or even worldwide stocks. The Navy's stock assessments in
its LOA applications are based on incomplete and out-of-date
information, leading to
[[Page 46861]]
a significant underestimation of species abundance and therefore
impacts.
Response: When there is no specific data on marine mammal
distribution, impact prediction modeling uses an even distribution over
the ocean area, since offshore concentrations of animals are not fixed
in space or time. Nearshore concentrations can be relatively fixed in
time or space, due to physical forcing from the steep bathymetry and
seasonal variations (e.g., Monterey Canyon or Hudson Canyon). However,
LFA sonar operates in deeper, offshore waters where the concentrations
are fluid due to changing water mass conditions. Therefore an even
distribution of animals is the one with the least assumptions.
Basically, the model assumes that individuals of the species can occur
anywhere within their ranges with equal probability over a long time.
On any given day, the distribution of any given species is likely to be
highly non-uniform. Over a long period of time the fluctuations in
density are likely to even out. Therefore, assuming an even
distribution for the purposes of assessing potential impacts is
reasonable and appropriate.
NMFS believes that the latest information available is used by NMFS
and the Navy when assessing impacts on marine mammals by LFA sonar.
Regarding beaked whale research, NMFS notes that the Office of Naval
Research (ONR) and SERDP (Strategic Environmental Research and
Development Program) has funded the following beaked whale research:
MacLeod, C. D., and G. Mitchell. 2006. Key areas for beaked whales
worldwide. J. Cetacean Res. Manage. 7(3):309-322.
MacLeod, C. D., W. F. Perrin, R. Pitman, J. Barlow, L. Balance, A.
D'Amico, T. Gerrodette, G. Joyce, K. D. Mullin, D. L. Palka, and G.
T. Waring. 2006. Known and inferred distributions of beaked whale
species (Cetacea: Ziphiidae). J. Cetacean Res. Manage. 7(3):271-286.
Redfern, J. V., M. C. Ferguson, E. A. Becker, K. D. Hyrenbach, C.
Good, J. Barlow, K. Kaschner, M. F. Baumgartner, K. A. Forney, L. T.
Ballance, P. Fauchald, P. Halpin, T. Hamazaki, A. J. Pershing, S. S.
Qian, A. Read, S. B. Reilly, L. Torres, and F. Werner. 2006.
Techniques for cetacean-habitat modeling. MEPS 310:271-295.
Ferguson, M. C., J. Barlow, B., S. B. Reilly, and T. Gerrodette.
2006. Predicting Cuvier's (Ziphius cavirostris) and Mesoplodon
beaked whale population density from habitat characteristics in the
Eastern Tropical Pacific Ocean. JCRM 7(3):287-299.
In addition, ONR and SERDP have funded the development and
fieldwork for the sound-and-orientation recording tag (DTAG), which has
been successfully attached with suction cups to beaked whales (Tyack et
al., 2006). These data are providing critically valuable information on
the movement and diving behaviors of beaked whales, both of which are
important to know in order to understand the acoustic exposure that the
animals may receive.
As stated in the Final SEIS Subchapter 2.7, the NMFS initial LOA
under Condition 7(d) required the Navy to conduct research in
accordance with 50 CFR Sec. 216.185(e). The SURTASS LFA sonar LTM
Program has been budgeted by the Navy at a level of approximately $1M
per year for five years, starting with the issuance of the first LOA.
The status of this research was summarized in Table 2-5 of the Final
SEIS. Finally, planning has commenced for a 2007-2008 deep-diving
odontocetes behavioral response study (BRS) to determine the potential
effects of LFA sonar, MFA, and seismic sources on beaked whales and
other deep diving odontocetes at an estimated cost of $3M per year. The
BRS study is discussed later in this document.
Regarding stock assessment data, the modeling analysis considers
the total amount of risk for each marine mammal species by summing a
particular species' risk estimate within that stock, across areas of
operation for each mission. This methodology does not assume that
populations are unstructured, but includes the best information
available on the reproductive behavior of each species at each mission
site in order to determine stock affiliation and the total risk to the
sustainability of each stock. Stock assessment data within U.S. waters
are required to be updated annually under the MMPA, with new stock
assessments being published when new data are available. The best
available data were used in all instances of the modeling analysis for
determining stock abundance and distribution.
The Navy states that it performs regular reviews of the latest
research, including updating stock and density data. The Navy's
applications for SURTASS LFA sonar LOAs are submitted after conducting
a thorough review of the latest data on the marine animals present in
the potential operating areas.
The Final EIS states, ``The model runs are designed to portray high
potential effects for each site. For example, seasons were selected
based on the potential for maximum LF-sensitive animal abundance.''
(Please see FOEIS/EIS Subchapters 4.2.1 and 4.2.2.2, and RTCs 4-3.8, 4-
3.9, and 4-3.11.)
Comment 41: The Navy incorrectly claims that significant impacts on
stocks and populations, as modeled for its LOA applications, would
necessarily occur at percentages lower than those assumed in the Navy's
modeling of coastal area and NMFS Final Rule, even disregarding the
underestimates of take resulting from the other errors described. The
Navy's approach to modeling behavioral impacts from multiple exposures
is not conservative.
Response: NMFS disagrees with the commenter's statement regarding
the Navy's approach to modeling behavioral impacts from multiple
exposures not being conservative. Subchapter 4.2.3.1 of the Final EIS
provides details on how the Navy derived the L + 5 log10(N)
formula for a single ping equivalent (SPE). The SPE concept is related
to widely accepted methods for comparing sounds of different durations.
It is universally acknowledged that increased exposure duration
increases the severity of potential impact. The SPE calculation is
conservative in assuming that the increase in potential effects
observed by extending the duration of a continuous sound stimulus
applies to a sequence of SURTASS LFA sonar pings, even though the
transmissions are separated by many minutes when the system is off.
This applies to SURTASS LFA sonar-type signals, not continuous sound.
In this process, an SPE received level is larger than the maximum RL of
any single ping in sequence. Also, the SPE for a sequence consisting of
a single loud ping and a long series of much softer pings is almost the
same as the level of a single loud ping. A ping duration (length) of 60
seconds was assumed in the modeling and risk assessment calculations
using SPE. The adoption of 60 seconds and 20 percent as the standard
ping duration and duty cycle, respectively, for calculations in the
Final EIS, provides a reasonable estimate of the potential for effects
from real-world SURTASS LFA sonar operations without sacrificing the
conservative nature of the analysis process.
Comment 42: There is an unknown history of exposure of animals in
an area where active sonar is regularly used.
Response: The adequacy of scientific information on marine animals
is discussed in Subchapter 1.4.2 of the Final EIS. It states that there
is an urgent need for better methods for measuring and estimating
potential risk. These data gaps have necessitated the use of various
models and extrapolations in order to provide a rational basis for the
assessment of potential risk from exposure to LF sounds. To address
some of these gaps, the Navy performed underwater acoustic modeling and
supported the LFS SRP to study the
[[Page 46862]]
potential effect of LF sound on free-ranging marine mammals. This
research did not specifically address the issue of LF impact on marine
mammal hearing; rather, it focused on the behavioral responses of
baleen whales to controlled exposure from SURTASS LFA sonar-like
signals. In general, understanding the mechanics of hearing and the
biological functions of sounds for marine mammals has improved
considerably over the past decade. Specific information on the effects
of most types of human-made underwater noise on marine animals is
incomplete, but has also increased in recent years. However, as the
environmental evaluation of the SURTASS LFA sonar system progressed,
the Navy recognized that additional research was required in several
areas to address some basic gaps in scientific knowledge. This included
development of a scientifically reasonable estimate of the underwater
sound exposure levels that may cause injury to marine mammals, and
research on the potential effects of LF sound on marine mammal
behavior. While recognizing that not all of the questions on the
potential for LF sound to affect marine life are answered, and may not
be answered in the foreseeable future, NMFS believes the Navy has
combined scientific methodology with a prudent approach throughout the
Final EIS and SEIS to protect the marine environment. Although there
are recognized areas of insufficient knowledge that must be accounted
for when estimating the potential direct and indirect effects on marine
life from SURTASS LFA sonar, the present level of understanding is
adequate to place reasonable bounds on potential impacts. Therefore,
though data on specific exposure of anthropogenic sounds, particularly
sonar, on the marine environment is limited, the Navy and NMFS have
taken this into account during their analyses. Moreover, we know much
more about the impacts of different types of sonar in the marine
environment today than we knew five years ago, when SURTASS LFA went
through the environmental compliance process the first time, and the
best scientific data that we have indicates that SURTASS LFA can be
operated safely with the prescribed mitigation, in a manner that has no
more than a negligible impact on marine mammal species and stocks.
Comment 43: There is a low level of accuracy with which the exposed
individuals can be monitored in real time.
Response: Sound field limits are estimated using near-real-time
environmental data and underwater acoustic performance models. These
models are an integral part of the SURTASS LFA sonar processing system.
The acoustic models help determine the sound field by predicting the
SPLs, or RLs, at various distances from the SURTASS LFA sonar source
location. Acoustic model updates are nominally made every 12 hours, or
more frequently when meteorological or oceanographic conditions change.
For further information, please see the Final SEIS, RTC 5.1.1. Though
individuals cannot be effectively monitored beyond the reach of the HF/
M3, the sound field is monitored in near-real-time.
Comment 44: The intense sound generated by military active sonar
can induce a range of adverse effects in whales and other species, from
significant behavioral changes to stranding and death. In a 2004
symposium at the International Whaling Commission (IWC), more than 100
whale biologists concluded that the association between sonar and
beaked whale deaths is very convincing and appears overwhelming. Mass
mortalities, though an obvious focus of much reporting and concern, are
likely only the tip of the iceberg of sonar's harmful effects. Marine
mammals are believed to depend on sound to navigate, find food, locate
mates, avoid predators, and communicate with each other. Flooding their
habitat with man-made, high-intensity noise interferes with these other
functions.
In addition to strandings and non-auditory injuries, the harmful
effects of high-intensity sonar include (1) temporary or permanent loss
of hearing; (2) avoidance behavior; (3) disruption of biologically
important behaviors such as mating, feeding, nursing, or migration, or
loss of efficiency in conducting those behaviors; (4) aggressive (or
agonistic) behavior; (5) masking of biologically meaningful sounds; (6)
chronic stress; (7) habituation; and (8) declines in the availability
and viability of prey species, such as fish and shrimp.
Response: The use of the term ``sonar'' does not reflect what Annex
K of the IWC 2004 Scientific Committee Report actually stated. The
Report does not implicate LFA sonar in the stranding of beaked whales.
The full text of the quoted statement is: ``The weight of accumulated
evidence now associates mid-frequency, military sonar with atypical
beaked whale mass strandings. This evidence is very convincing and
appears overwhelming.''
There are different types of anthropogenic sounds associated with
possible impacts to and strandings of marine mammals. There are naval
sonar and seismic airgun arrays, each with different characteristics
and purposes. Many lump these types together. Accordingly, when there
is a stranding that may be associated with the use of one type of sonar
or sound source, all sources are implicated--a premise that does not
stand up to scientific scrutiny in the marine bio-acoustics community.
A wide range of naval sonars are used to detect, localize and classify
underwater targets. For the purposes of the SURTASS LFA sonar Final
SEIS, the MMPA application, and this Final Rule, these systems are
categorized as LFA sonar (less than 1000 Hz) and MFA sonar (1 to 10
kHz). Table 1 in this document provides pertinent information on
different types of LFA sonar and MFA sonar. General information is also
provided on airgun arrays. (We also note that sonar signals are
generally coherent while air guns are impulsive.)
Table 1.--Comparison of Underwater Acoustic Source Properties
----------------------------------------------------------------------------------------------------------------
SURTASS LFA
Source type sonar AN/SQS 53C (MF) AN/SQS 56 (MF) Air gun array (LF)
----------------------------------------------------------------------------------------------------------------
Source Level.................. 215 dB per 235 dB.......... 223 dB.......... 260 dB.
element.
Pulse Duration................ Variable 6 to 1-2 s........... 1-2 s........... 0.02 s.
100s. Never
longer than 10s
at single freq.
Inter-pulse Time.............. 6 to 15 min..... 24 s............ 24 s............ 9-14 s.
Center Frequency.............. 100-500 Hz...... 2.6 & 3.3 kHz... 6.8, 7.5, & 8.2 Broadband.
kHz.
Bandwidth..................... 30 Hz........... 100 Hz.......... 100 Hz.......... Wideband.
Source Depth.................. Array 87 to 157 8 m............. 6 m............. 6-10 m.
m. Center 122 m.
Beamwidth..................... Omni-directional 40 degrees...... 30 degrees...... Function of freq.
in horizontal.
[[Page 46863]]
Beam Direction................ Horizontal...... 3 degrees down Horizontal...... Vertical.
from horizontal.
----------------------------------------------------------------------------------------------------------------
MF = mid frequency; LF = low frequency.
Source: D'Spain et al. (2006); DON (2001).
Cox et al. (2006) provides a summary of common features shared by
the strandings events in Greece (1996), Bahamas (2000), and Canary
Islands (2002). In addition to use of MF sonar, these included deep
water close to land (such as offshore canyons), presence of an acoustic
waveguide (surface duct conditions), and periodic sequences of
transient pulses (i.e., rapid onset and decay times) generated at
depths less than 10 m (32.8 ft) by sound sources moving at speeds of
2.6 m/s (5.1 knots) or more during sonar operations (D'Spain et al.,
2006). A number of these features do not relate to LFA sonar
operations. First, the SURTASS LFA sonar vessel operates with a
horizontal line array (SURTASS: a passive listening system) of 1,500 m
(4,921 ft) length at depths below 150 m (492 ft) and a vertical line
array (LFA sonar source) at depths greater than 100 m. Second,
operations are limited by mitigation protocols to at least 22 km (12
nm) offshore. Therefore, for these reasons SURTASS LFA sonar cannot be
operated in deep water that is close to land. Finally, the LFA sonar
signal is transmitted at depths well below 10 m (32.8 ft), and the
vessel has a slow speed of advance of 1.5 m/s (3 knots).
While there was a LF component to the sonar potentially related to
the Greek stranding in 1996, only mid-frequency components were present
in the strandings in the Bahamas in 2000, Madeira in 2002, and Canaries
in 2002. This supports the logical conclusion that the LF component in
the Greek stranding was not causative (ICES, 2005; Cox et al., 2006).
In its discussion of the Bahamas stranding, Cox et al. (2006) stated,
``The event raised the question of whether the mid-frequency component
of the sonar in Greece in 1996 was implicated in the stranding, rather
than the low-frequency component proposed by Frantzis (1998).'' The
ICES in its ``Report of the Ad-Hoc Group on the Impacts of Sonar on
Cetaceans and Fish'' raised the same issue as Cox et al., stating that
the consistent association of MF sonar in the Bahamas, Madeira, and
Canary Islands strandings suggest that it was the MF component, not the
LF component, in the NATO sonar that triggered the Greek stranding of
1996 (ICES, 2005).
Most odontocetes, such as beaked whales, have relatively sharply
decreasing hearing sensitivity below 2 kHz. If a cetacean cannot hear a
sound of a particular frequency or hears it poorly, then it is unlikely
to have a significant behavioral impact (Ketten, 2001). Therefore, it
is unlikely that LF transmissions from LFA sonar would induce
behavioral reactions from animals that have poor LF hearing, e.g.
beaked whales, bottlenose dolphins, striped dolphins, harbor porpoise,
belugas, and orcas (summarized in: Nedwell et al., 2004).
New data describing potential mechanisms of harm to marine mammals
from sonar are concerned with acoustically mediated bubble growth and
resonance. Cox et al. (2006) stated that it is premature to judge
acoustically mediated bubble growth as a potential mechanism and
recommended further studies to investigate the possibility. The
analysis by the Navy (Cudahy and Ellison, 2002) and reports from two
workshops on acoustic impacts (DOC, 2002; Cox et al., 2006) support the
conclusion that resonance from LFA sonar operations is not a
``reasonably foreseeable'' impact. The ICES (2005) report concluded
that no strandings, injury, or major behavioral change has yet to be
associated with the exclusive use of LF sonar. Please see Final SEIS
RTCs 2.5.2 and 4.0.3 for additional discussions.
Therefore, the numerous scientists, who participated in the 2004
Workshop convened by the U.S. Marine Mammal Commission (Cox et al.,
2006), and the ICES AGISC (2005), support the logical conclusion that
LFA sonar is not related to marine mammal strandings.
The masking effect of the SURTASS-LFA sonar signal will be limited
for a number of reasons. First, the bandwidth of the system is limited
(30 Hz), and the instantaneous bandwidth at any given time of the
signal is small, on the order of 10 Hz. Therefore, within the frequency
range in which masking is possible, the effect will be limited because
animals that use this frequency range typically use signals with
greater bandwidth. Thus, only a portion of the animal's signal would be
masked by LFA sonar. Furthermore, the average duty cycle when LFA sonar
is in operation, is always less than 20 percent, and based on past LFA
sonar operational parameters (2003 to 2007) is nominally 7.5 to 10
percent (as stated in Chapter 2 of the Final SEIS) which means that for
80-92.5 percent of the time there is no risk of animal signals being
masked by the LFA sonar signal when LFA sonar is operating. Therefore,
within the area in which masking is possible, the effect will be
limited because animals that use this frequency region typically use
broader bandwidth signals. As a result, the chances of an LFA sonar
sound actually overlapping whale calls at levels that would interfere
with their detection and recognition would be extremely low. The
potential effects of masking are discussed in the Final SEIS RTCs 4.3.1
and 4.3.23.
In regards to biologically significant behaviors, the risk
continuum explicitly represents the potential for significant change in
a biologically important behavior within the 119 to 180 dB RL range.
For additional information, please see the previous discussion on this
issue and also the Final EIS (RTCs 4-5.2, 4-5.6, 4-5.12, 4-5.22, 4-6.2,
4-6.3), and Appendix D. The conclusion that the potential effects on
the stocks of marine mammals from behavioral changes would be minimal
is discussed in the Final SEIS (RTC 4.3.29). It is reiterated that
during Phase I of the LFS SRP research, there were times when the test
source level was at the higher, operational level. During such test
periods received levels at the subject animals were within the range as
specified in the research permit and responses were no different than
those observed when using lower source levels.
The Miller et al. (2000) article ``Whale songs lengthen in response
to sonar'' concerning observations of male humpback whales during Phase
III of the LFS SRP was addressed in the Final OEIS/EIS RTC 4-5.19 and
in NMFS Final Rule RTC SIC16 and SIC17. Fristrup et al. (2003) used a
larger data set from Phase III to describe song length variability and
to explain song length variation in relation to LF broadcasts. In spite
of methodological and sample size differences, the results of the two
analyses were generally in agreement, and both studies indicated
[[Page 46864]]
that humpback whales tend to lengthen their songs in response to LF
broadcasts.
The Fristrup et al. (2003) results provide a detailed picture of
short-term response as compared to behavioral variation observed in the
absence of the stimuli. These responses were relatively brief in
duration, with all observed effects occurring within 2 hours of the
last LFA sonar source transmission. It should be noted that these
effects were not salient to the acoustic observers on the scene, but
were revealed by careful statistical analyses (Fristrup et al., 2003).
Aside from the delayed responses, other measures failed to indicate
cumulative effects from LF broadcasts, with song-length response being
dependent solely on the most recent LF transmission, and not the
immediate transmission history. The modeled seasonal factors (changes
in density of whales sighted near shore) and diurnal factors (changes
in surface social activities) did not show trends that could be
plausibly explained by cumulative exposure. Increases in song length
from early morning to afternoon were the same on days with and without
LF transmissions, and the fraction of variation in song length that
could be attributed to LF broadcast was low. Fristrup et al. (2003)
found high levels of natural variability in humpback song length and
interpreted the whales' responses to LF broadcasts to indicate that
exposure to LFA sonar would not impose a risk of dramatic changes in
humpback whale singing behavior that would have demographic
consequences.
The effects of SURTASS LFA sonar on fish are discussed elsewhere in
this document. Based on the analysis in the Final SEIS, Chapter 4.1, it
is not believed that marine mammal prey species will be affected by
SURTASS LFA sonar.
Comment 45: The proposed rule-making cites the ICES report on sonar
(which was written partly by non-independent scientists receiving
funding from U.S. or Royal Navy, or working for the U.S. government),
but does not cite the conclusions or reports from the IWC Scientific
Committee (SC) (which consists of several hundred international,
independent scientists), whose concerns include lack of monitoring and
inappropriateness of current mitigation measures.
Response: The SEIS cited the ICES report, which was written by
experts in the marine field. The SEIS also cited the Journal of
Cetacean Resources Management, which is published by the IWC. Since no
citation was provided by the commenter, it is unclear which IWC
publication the comment refers to. The SEIS cited Cox et al. (2006),
which was published in the Journal of Cetacean Resources Management.
This article discusses monitoring and mitigation, focusing on beaked
whales, but the monitoring and mitigation discussion was not
specifically discussed in the Final SEIS. The conclusions on monitoring
and mitigation state ``Current visual survey efforts to detect beaked
whales in areas of acoustic activity are probably ineffective as a
mitigation aid. Key limiting factors include sea state, amount of
daylight, experience of observers and the diving and surfacing behavior
of beaked whales, which makes them either difficult to see or
unavailable for visual observation at the surface for long periods of
time. For the same reasons, surveys to determine distribution and
abundance are also difficult and limited in their reliability. However,
additional sensing technologies, such as passive acoustics, active
sonar and radar, are currently in development that may increase
scientists' abilities to detect beaked whales.'' As discussed in the
Final SEIS, the Final Comprehensive Report and NMFS' Proposed Rule, the
agencies recognize that visual monitoring is limited, particularly due
to the factors such as sea state and daylight, as discussed in Cox et
al. (2006). The final rule also requires passive acoustics, estimated
to be 32 percent effective with visual monitoring and active acoustics,
the HF/M3, which has a calculated effectiveness of 95 percent. The use
of this tri-partite monitoring raises overall mitigation effectiveness
to 98 percent. Therefore, the Navy will conduct the monitoring and
mitigation measures recommended in Cox et al. (2006).
Comment 46: The Navy's assessment of the risk of marine mammal
injury and mortality from LFA sonar use is deficient. The problems with
the Navy's calculation of thresholds for injury and behavioral
disturbance, (mentioned previously in their October, 2006 letter) carry
through to its analysis of the risk of injury.
Response: NMFS does not agree. The Navy believes that the unusual
or innovative nature of LFA sonar is what sets it apart from other
anthropogenic sources, especially tactical, mid-frequency sonar and
makes it much less likely to cause strandings of those marine mammals
most associated with anthropogenic sound-related strandings (i.e.,
odontocetes, especially beaked whales). First, odontocetes generally
have poor LF hearing. Second, the LFA sonar transmit array depth is
well below 10 m (33 ft) and thus not likely to be entrained in a
surface duct. Third, the 6 to 15 minute off-time in between 60-second
transmissions and narrow bandwidth (30 Hz) generally preclude masking.
SURTASS LFA sonar has been operating since 2003 in a restricted
area in the western Pacific Ocean, with approximately 470 hours of
transmit time under the first four years of the LOAs. These extensive
operations, with mitigation, have produced no known Level A takes on
marine mammals. As noted before, LFA sonar is not the same as MFA
(please see the Comment 44 in this document and the Final SEIS RTC
4.0.3 and 4.3.7). There is no evidence that SURTASS LFA sonar has
caused injuries below or within the 180-dB mitigation zone as verified
by mitigation monitoring requirements of the LFA sonar safety zone.
Therefore, the 180-dB injury threshold remains valid, as does the
effectiveness of the mitigation measures within the 180-dB potential
injury zone.
The potential for SURTASS LFA sonar to cause harm to marine mammals
and the validity of the 180-dB injury threshold for SURTASS LFA sonar
are discussed in the Final SEIS RTCs 4.0.1, 4.0.2, 4.0.3, 4.3.1, 4.3.2,
4.3.7, 4.3.8, 4.3.9, 4.3.10, and 4.3.12. LFA sonar will not cause
physical harm to marine mammals below 180 dB RL. Moreover, mitigation
within the 180-dB mitigation zone is effective (See the Final EIS
Subchapter 2.3.2.2).
Comment 47: The Navy wrongly dismisses mechanisms of sonar injury
to marine mammals that would cause harm independent of stranding
events. The Navy portrays a leading theory that whales suffer from
bubble growth in organs that is similar to decompression sickness, or
``the bends'' in human divers as a controversial hypothesis. The Navy
and NMFS cannot omit the numerous published, peer-reviewed papers that
support this theory, or disregard the recognition bubble growth has
received from expert panels, such as the one convened in 2004 by the
Marine Mammal Commission to review sonar-related strandings. The Navy's
analysis of injuries to whales leaves out a possibility that has been
widely noted in literature, that some of the observed injuries are a
result of behavioral changes, such as rapid surfacing or premature
diving, that sonar could induce. In describing the 2000 Bahamas
stranding event, the Navy places undue reliance on a list of
``contributory factors'' that it feels make a similar event unlikely to
reoccur. We do not doubt that certain factors, such as the use of sonar
in channels, can increase the risk of harm; but it is abundantly
evident from the literature that has emerged since the government's
[[Page 46865]]
Bahamas report appeared in 2001 that strandings may well occur in their
absence.
Response: NMFS has not dismissed any of the mechanisms of sonar
injury to marine mammals that would cause harm independent of stranding
events. One form of injury theorized to be caused by marine mammal
reactions to sonar is gas-bubble disease. Cox et al. (2006) (which is
the only reference cited by the commenter on this issue) stated that
gas-bubble disease, induced in supersaturated tissues by a behavioral
response to acoustic exposure, is a plausible pathologic mechanism for
the morbidity and mortality seen in cetaceans associated with mid-
frequency sonar exposure. They also state that it is premature to judge
acoustically mediated bubble growth as a potential mechanism and
recommended further studies to investigate the possibility. Since the
Draft SEIS was published, there has been additional information
available on this theory. If acoustically mediated bubble growth does
prove to be the mechanism leading to mortality and/or strandings of
beaked whales, then the fact that LFA sonar has not been associated
with any of these strandings would indicate that it would be less
likely to cause this effect.
Comment 48: In addition, the Navy has failed to consider most of
the mass beaked whale strandings that have been identified for their
association, or possible association, with sonar and the fact that some
marine mammal species are especially vulnerable to acoustical injuries.
The Navy overestimates the importance of the fact that the long history
of strandings associated with military sonar has usually implicated
mid-frequency sonar. Many in the scientific community, including NMFS
biologists, have expressed concern, based on the best available
evidence, that low frequency sound could potentially induce similar
effects. The NRDC believes that the Navy places far too much confidence
in its assertion that its use of SURTASS LFA sonar in the last few
years has not resulted in marine mammal strandings.
Response: While NMFS shares this concern, to date, SURTASS LFA
sonar has not been linked with any stranding events, other than by name
association with MF sonar. This was discussed previously in this
document. As related to LFA sonar, the Navy performed extensive
research to determine the potential for LF transmissions to cause
significant behavioral effects in whales (the LFS SRP).
Given that the LFA sonar sound source can be detected at moderate
to low levels over large areas of the ocean, there was concern at the
initiation of the Navy's NEPA process in 1996 that there was the
potential for large percentages of species stocks to be exposed to
moderate-to-low received levels. If animals are disturbed at these
moderate-to-low exposure levels such that they experience a significant
change in a biologically important behavior, then such exposures could
potentially have an impact on rates of reproduction or survival.
Knowing that cetacean responses to LF sound signals needed to be better
defined using controlled experiments, the Navy helped develop and
supported the three-year LFS SRP beginning in 1997. This study focused
on baleen whales because, as low frequency hearing specialists they are
believed to be the most sensitive to LFA sound and thus most likely to
have an adverse behavioral reaction. This field research program was
designed to address three important behavioral contexts for baleen
whales: (1) Blue and fin whales feeding in the southern California
Bight; (2) gray whales migrating past the central California coast; and
(3) humpback whales breeding off Hawaii. Taken together, the results
from the three phases of the LFS SRP do not support the hypothesis that
most baleen whales, who are expected to be most sensitive to LF sounds,
exposed to RLs near 140 dB would exhibit disturbance behavior and avoid
the area. These experiments, which exposed baleen whales to RLs ranging
from 120 to about 155 dB, detected only minor, short-term behavioral
responses. Short-term behavioral responses do not necessarily
constitute significant changes in biologically important behaviors.
Although the LFS SRP did not involve beaked whales, there was no
indication during these tests that whales surfaced rapidly or dove
prematurely in response to LFA sonar source transmissions. NMFS
believes therefore, it is unlikely that, at least for fin, gray and
humpback whales exposed to low levels of LFA sonar sounds will not
result in the behavioral reactions theorized for beaked whales exposed
to MF sonar signals. However, while this does that mean that LF sonar
will not cause similar, but presently unknown, reactions in beaked
whales, NMFS believes, that based on the best information available,
such information does not currently exist. Therefore, NMFS believes,
based on our current state of knowledge, it is unlikely that marine
mammals would be severely injured by LFA sonar at great distances from
the source.
Comment 49: The Navy attempts to discount the well-established link
between sonar use and marine mammal injuries and mortalities by
suggesting (based on data compiled when acoustic impacts were not
generally considered as a potential cause of strandings) that a
majority of marine mammals strandings are related to natural causes.
Finally, the Navy states, incorrectly, that ``there are no new data
that contradict any of the assumptions or conclusions in the Final
EIS.'' New data exists linking whale strandings to naval sonar; linking
non-stranding injuries in marine mammals to naval sonar; describing
mechanisms of harm to marine mammals from sonar; showing unexpectedly
high propagation of noise in shallow waters; finding that intense noise
sources can mask whale calls over great distances; and revealing the
difficulties for noise impacts.
Response: As indicated elsewhere in this response, most marine
mammal strandings are unrelated to the use of sonar. While the
recognition that there was a link between tactical sonars and beaked
whale strandings was slow to develop, that in no way should be
interpreted to mean that strandings involving sonar are either common
or long-occurring.
NMFS believes the issue for this rulemaking is not whether sonar
causes mass strandings of beaked whales, but whether SURTASS LFA sonar
has the potential to cause marine mammal strandings. The evidence to
date, supported by scientific reports, such as ICES (2005), Cox et al.
(2006), and D'Spain et al. (2006), is that SURTASS LFA sonar has not
caused any strandings. In reference to the contributory factors for
strandings, the Bahamas 2000 stranding event did not involve LFA sonar.
The list of ``contributing factors'' is generally supported by the
workshop on understanding the impacts of anthropogenic sound on beaked
whales convened by the U.S. Marine Mammal Commission in 2004 (Cox et
al., 2006) and the analysis by D'Spain et al. (2006). Whether or not
surface ducts occurred during other reported strandings is not relevant
to LFA sonar operations. First, NMFS believes LFA sonar operations will
not cause physical injury to marine mammals at received levels below
180 dB. Second, LFA sonar signals are initially transmitted
substantially below 10 m (32.8 ft) depth and are not likely to have
signal strength above 180 dB in the surface duct. Surface ducting
conditions were analyzed in the Final EIS at a number of the 31 model
sites. Therefore, with LFA sonar mitigation, no marine
[[Page 46866]]
mammals, either with or without a surface duct, are expected to be
exposed to injurious levels of LFA sonar signals.
The evidence to date, supported by scientific reports, such as ICES
(2005), Cox et al. (2006), and D'Spain et al. (2006), is that SURTASS
LFA sonar has not caused any strandings. Beaked whales, which hear best
in the mid-frequency range appear to be most vulnerable to acoustic-
induced stranding. These animals hear poorly in the low frequency
range. The LFS SRP specifically studied the behavioral reactions of
baleen whales, which hear best in the low frequency range, and thus
were concluded to be most at risk (potentially) from the operation of
LFA sonar. The three-phase LFS SRP involved more than 20 scientists
from 6 universities and independent research groups. The results of the
LFS SRP demonstrated that behavioral responses predictably occurred at
received levels around 140 dB, not at the lower decibel levels that had
been previously predicted. Moreover, the results showed that behavioral
responses lasted for only a matter of tens of minutes and involved only
modest changes in behavior. These results plus a five-year history of
safely operating SURTASS LFA sonar without evidence of strandings or
injury supports NMFS conclusion that the system can be operated, with
appropriate mitigation measures, in manner that has no more than a
negligible impact on marine mammal species and stocks.
In the Final SEIS Subchapter 4.4.3, the Navy discusses both
anthropogenic and natural causes of marine mammal strandings. In the
conclusion in Subchapter 4.4.3.4, it is stated that military sonar is
not the principal cause of marine mammal strandings. There was no
conclusion that the majority of marine mammal strandings were related
to only natural causes. The Navy did not intend to give the impression
that it discounts any scientifically-supported links between
anthropogenic sources and marine mammal strandings. However, it will
point out that there is no known connection between marine mammal
strandings and LFA sonar, which is supported by scientific workshops,
reports, and published papers (ICES, 2005; Cox et al., 2006; D'Spain et
al., 2006).
Finally, to address the comment that there is no new data to
contradict any of the assumptions or conclusions in the Final EIS, in
order to address the comment, it must be pointed out once again that
there are different types of anthropogenic sounds potentially
associated with possible impacts to and strandings of marine mammals.
These are naval sonar and seismic airgun arrays, each with different
characteristics and purposes. Many comments lump these types under one
heading, loud naval sonars or military sonars; or loud anthropogenic
noise sources including sonars and seismic survey airguns. Thus, when
there is a stranding that may be associated with the use of one type of
sonar or sound source, it gets blamed on sonar as a whole-a premise
that is not true and one that does not stand up to scientific scrutiny
from the marine bio-acoustics community. A wide range of naval sonars
are used to detect, localize and classify underwater targets. For the
purposes of the SURTASS LFA sonar Final SEIS analysis, these systems
are categorized as LFA sonar (less than 1000 Hz) and MFA sonar (1 to 10
kHz). Table 1 provides pertinent information on different types of LFA
sonar and MFA sonar. General information is also provided on airgun
arrays. Sonar signals are generally coherent while air guns are
impulsive.
Cox et al. (2006) provided a summary of common features shared by
the strandings events in Greece (1996), Bahamas (2000), and Canary
Islands (2002). These included deep water close to land (such as
offshore canyons), presence of an acoustic waveguide (surface duct
conditions), and periodic sequences of transient pulses (i.e., rapid
onset and decay times) generated at depths less than 10 m (32.8 ft) by
sound sources moving at speeds of 2.6 m/s (5.1 knots) or more during
sonar operations (D'Spain et al., 2006). A number of these features do
not relate to LFA sonar operations. First, the SURTASS LFA sonar vessel
operates with a horizontal line array (SURTASS: a passive listening
system) of 1,500 m (4,921 ft) length at depths below 150 m (492 ft) and
a vertical line array (LFA sonar source) at depths greater than 100 m.
Second, operations are limited by mitigation protocols to at least 22
km (12 nm) offshore. Therefore, for these reasons SURTASS LFA sonar
cannot be operated in deep water that is close to land. Finally, the
LFA sonar signal is transmitted at depths well below 10 m (32.8 ft),
and the vessel has a slow speed of advance of 1.5 m/s (3 knots).
While it is true that there was a LF component of the sonar
potentially related to the Greek stranding in 1996, only mid-frequency
components were present in the strandings in the Bahamas in 2000,
Madeira 2002, and Canaries in 2002. This supports the logical
conclusion that the LF component in the Greek stranding was not
causative (ICES, 2005; Cox et al., 2006). In its discussion of the
Bahamas stranding, Cox et al. (2006) stated, ``The event raised the
question of whether the mid-frequency component of the sonar in Greece
in 1996 was implicated in the stranding, rather than the low-frequency
component proposed by Frantzis (1998).'' The ICES in its ``Report of
the Ad-Hoc Group on the Impacts of Sonar on Cetaceans and Fish'' raised
the same issue as Cox et al., stating that the consistent association
of MF sonar in the Bahamas, Madeira, and Canary Islands strandings
suggest that it was the MF component, not the LF component, in the NATO
sonar that triggered the Greek stranding of 1996 (ICES, 2005).
Most odontocetes, such as beaked whales, have relatively sharply
decreasing hearing sensitivity below 2 kHz. If a cetacean cannot hear a
sound of a particular frequency or hears it poorly, then it is unlikely
to have a significant behavioral impact (Ketten, 2001). Therefore, it
is unlikely that LF transmissions from LFA sonar would induce
behavioral reactions from animals that have poor LF hearing, e.g.
beaked whales, bottlenose dolphins, striped dolphins, harbor porpoise,
belugas, and orcas (summarized in: Nedwell et al., 2004).
New data describing potential mechanisms of harm to marine mammals
from sonar are concerned with acoustically mediated bubble growth and
resonance. Cox et al. (2006) stated that it is premature to judge
acoustically mediated bubble growth as a potential mechanism and
recommended further studies to investigate the possibility. The
analysis by the Navy (Cudahy and Ellison, 2002) and reports from two
workshops on acoustic impacts (DOC, 2002; Cox et al., 2006) support the
conclusion that resonance from LFA sonar operations is not a
``reasonably foreseeable'' impact.
The ICES (2005) report concluded that no strandings, injury, or
major behavioral change has yet to be associated with the exclusive use
of LF sonar.
Based on the above discussions, there are no ``new'' data: (1)
Linking LFA sonar to whale strandings, (2) linking LFA sonar to non-
stranding related injuries, or (3) describing mechanisms of harm to
marine mammals from LFA sonar.
Regarding unexpectedly high propagation of noise in shallow water,
this concerns the measurement of propagation of broadband noise from
air gun arrays in both deep and shallow water (Tolstoy et al., 2004).
As noted in Table 1, there are substantial differences between the
impulsive sounds of air guns and the coherent signals from LFA
[[Page 46867]]
sonar, so that one must be careful in how they are compared. First,
while Tolstoy et al. (2004) found that when their calibrations were
conducted in deep water (at 3200 m (10,500 ft)) and slope waters (at
500 m (1641 ft)), the predicted and measured distances to the received
level of 160 dB from the air gun arrays indicated that the predicted
radii tended to overestimate actual 160 dB RL ranges. (This implied
that the 180-dB radii for all arrays should be less than the predicted
1 km (0.54 nm), likely significantly less.) Second, they found that
their actual measurements for shallow water (30 m (98 ft)) had been
underestimated when compared to the same predicted values used for the
deep water comparison. This was due to the model not taking into
account interaction with the ocean bottom. In deep, homogenous water,
sound initially spreads spherically (spherical spreading) and its
intensity decreases in proportion to the square of the range. Once
sound has propagated to a distance approximately equal to the water
depth, it is physically constrained and propagates cylindrically
(cylindrical spreading). When this occurs, its intensity decreases in
direct proportion to the range (please see Final EIS, Appendix B). Most
importantly, however, SURTASS LFA sonar will not operate in water less
than 200 m (656.2 ft), most likely always operating in deep and slope
waters. Sound propagation from deep offshore waters onto shallower
shelf waters will almost always decrease quickly due to bottom and
surface interaction with the sound. This means that LFA sonar sounds
will more quickly decrease in intensity in shallow water than in other
waters. Lastly, the Tolstoy et al.(2004) findings are not applicable to
the SURTASS LFA sonar analysis because the propagation models utilized
for LFA sonar are empirically validated and correctly account for
critical variables, such as water depth (Final EIS Subchapters 4.2,
4.2.1 and 4.2.2; and Technical Report 2).
The masking effect of the SURTASS-LFA sonar signal will be limited
for a number of reasons. First, the bandwidth of the system is limited
(30 Hz), and the instantaneous bandwidth at any given time of the
signal is small, on the order of 10 Hz. Therefore, within the frequency
range in which masking is possible, the effect will be limited because
animals that use this frequency range typically use signals with
greater bandwidth. Thus, only a portion of the animal's signal would be
masked by the LFA sonar. Furthermore, when LFA sonar is in operation,
the LFA sonar source is active only 7.5 percent of the time (based on
historical LFA sonar operational parameters) and no more than 20
percent, which means that for 80-92.5 percent of the time there is no
risk of animal signals being masked by the LFA sonar signal when LFA
sonar is operating. Therefore, within the area in which masking is
possible, the effect will be limited in duration and because animals
that use this frequency region typically use broader bandwidth signals
that allow them to communicate even when SURTASS LFA sonar is
transmitting.
Finally, NMFS does not believe that the Navy has experienced
difficulties in executing the mitigation procedures required by NMFS
for LFA sonar, which are based on protecting marine animals from
injury. Because it is impractical and infeasible for mitigation to
cover vast oceanic areas, where the received levels do not cause
physical injury to marine mammals or jeopardize threatened or
endangered species, the laws provide methods for authorizations for
limited non-injurious impacts to marine mammals and listed species.
NMFS believes that SURTASS LFA sonar has met all of these requirements
and has been operating since 2003-without any known physical injuries
to marine animals. Potential non-injurious impacts are estimated based
on location and times of operations and best available abundance and
density data for the areas and seasons of the operations. These are
reported to NMFS both quarterly and annually as required by regulation
(50 CFR Sec. 216 Subpart Q).
Comment 50: We don't know the impact of SURTASS LFA sonar on
species, stocks, and ecological processes over time. Therefore, NMFS
can't say stock-level effects are ``not reasonably likely'' to occur.
Response: When compared to other naturally occurring and
anthropogenic sources of noise in the ocean, LFA sonar, barely
contributes a measurable portion of acoustic energy in the oceans.
Other sources of marine anthropogenic sound that add appreciably to the
oceanic ambient noise level are commercial shipping, offshore oil and
gas exploration, and other uses of naval sonars (ICES, 2005). Also, the
low duty cycle (7.5 to 20 percent) of LFA sonar, the lack of known
strandings where LFA sonar has operated, and the results of the LFS SRP
support NMFS'' conclusion that SURTASS LFA sonar is neither expected to
significantly add to oceanic ambient noise, nor result in significant
behavioral responses in marine mamals in waters distant from the LFA
sonar vessels, and therefore not likely to have population level
impacts. Based on extensive evaluation in the Final EIS and the Final
SEIS, the operation of SURTASS LFA sonar, with monitoring and
mitigation is not expected to result in lethal takes or serious injury.
In addition, no lethal takes are being authorized by NMFS either under
this rule or the LOAs issued under the rule. This finding is also
supported by the fact that SURTASS LFA sonar has been operating since
2003 in the northwestern Pacific Ocean with no reported Level A
(injury) harassment takes or strandings associated with its operations
(DON, 2007a). Moreover, there has been no new information or data that
contradict NMFS'' finding that the potential impacts from SURTASS LFA
sonar operation on any stock of marine mammal will be negligible.
Comment 51: The proposed rule implies that there have been only
three sonar-related stranding incidents, when it is known that there
have been multiple incidents off the Canary Islands, several likely
incidents in the Mediterranean, unusually high rates of strandings
adjacent to naval bases in Japan, and published data (in a peer-
reviewed journal) of high stranding rates and animals showing signs of
acoustic trauma of cetaceans in Taiwan, occurring coincident with U.S.
military and Chinese submarine-utilizing exercises, amongst other
things.
Response: The Navy's intention in the Draft SEIS was to examine
three of the more studied stranding events in which naval sonars were
implicated as a potential cause, not to indicate that there have been
only three stranding events. The subchapter was expanded in the Final
SEIS (Subchapter 4.4.3). However, NMFS believes that the issue is
whether SURTASS LFA sonar has caused strandings or could cause
strandings in the future. The evidence to date, supported by recent
scientific reports, supports the conclusion that the U.S. Navy's LFA
sonar is not likely to cause marine mammal strandings. The information
supporting this conclusion has been provided in Comment 44 and 47 in
this document.
No citation was given with this comment but NMFS assumes that the
reference to a recent paper on strandings in Japan refers to the
examination by Brownell et al. (2004) which evaluated Cuvier's beaked
whale strandings from local records between 1950 and 2004 in the waters
of Japan. Two facts were presented in this paper: (1) Cuvier's beaked
whales stranded in Sagami and Suruga Bays between 1960 and 1990; and
(2) U.S. Naval vessels are stationed in Yokosuka, Japan. From these two
facts, the authors infer, without any evident support, that the second
caused
[[Page 46868]]
the first. Based on our review of the paper, we conclude that the
authors' assumption is not supported by the available evidence. First,
the authors' primary source (Ishikawa, 1994) is not readily available
to review because it is in Japanese and no translation was provided
except for Table 1 in their report. There are inconsistencies in
Brownell et al.'s presentation of the data and results, which could not
be compared to the cited sources of the data. Table 1 is titled ``Mass
strandings of Cuvier's beaked whales Ziphius cavirostris, on the
central Pacific coast of Honshu'' and states that the data are from
Ishikawa (1994). The number of stranded animals listed from 1960 to
1990 in the table is 47. The first page of their report states
``Ishikawa (1994) reported 68 Cuvier's beaked whales that stranded on
the coast of Japan between 1960 and 1993.'' This begs two questions:
(1) Where did the remaining 21 beaked whales strand; and (2) why were
they not listed? In their results, Brownell et al. (2004) state that
Ishikawa (1994) records include eight cases of mass strandings
(correct, based on Table 1) with a total of 43 individuals (incorrect,
based on Table 1, the number should be 35). Finally, general data from
the National Science Museum, Tokyo, is provided without citation. Given
that the data from Ishikawa (1994) is presented in an inconsistent
manner, the museum data is vital for any effective analysis of the
Brownell et al. (2004) report.
It is inaccurate to state, as the Brownell et al. (2004) paper
does, that Cuvier's beaked whales are stranding due solely to naval
sonar operations. The authors infer several times in the paper that
``naval operations with acoustic components'' or ``the Navy may have
tested MFA'' has no foundation and is pure speculation. The ports of
Tokyo, Chiba, Kawakai, Yokohama, and Yokosuka are all located on Tokyo
Bay, which opens to Sagami Bay. Suruga Bay is separated from Sagami Bay
by a large peninsula. Based on the locations, it is most likely that
other natural and anthropogenic factors contributed to at least some of
the reported strandings. These include dense shipping traffic/shipping-
related noise, construction-related noise, dredging, scientific
research using active sources, pollution, fisheries interactions,
earthquakes, pollution from increased human population, etc.
Therefore, because of the irreconcilable inconsistencies, Brownell
et al. (2004) do not provide any reliable and supportable linkage
between Cuvier's beaked whale stranding events and naval activities in
Japanese waters near Yokosuka. The only data that the Navy could
confirm were that there is a major U.S. naval base there and that the
area is also home to five major Japanese seaports, including Tokyo, one
of the world's busiest seaports, with an average of 33,000 vessels
arriving annually.
At the time the Final SEIS was published, a non-citable paper
describing stranding events in Taiwan was being circulated. Even though
the Navy requested but was not given permission by the authors to cite
the paper, the strandings are reported to have occurred in the winter
of 2004 and were part of the SEIS stranding assessment. These
strandings were reported in the Cetacean Stranding Database (http://www.legaard.org/strandings/index.html
), which was utilized as part of
the overall marine mammal stranding evaluations in both the Final SEIS
and the Final Comprehensive Report (DON, 2007a, 2007b). The review of
recent stranding data from the National Science Museum of Tokyo, Japan;
the Cetacean Stranding Database; other Internet sources; and
international reports, did not indicate any stranding events associated
with the times and locations of LFA sonar operations in the
northwestern Pacific Ocean.
The authors of the initial report on the 2004 Taiwan strandings
have now published their findings in the Journal of Cetacean Research
and Management (Wang and Yang, 2006). This paper also includes
additional Taiwanese stranding events in the winter and summer of 2005.
A review of these additionally reported strandings events did not
indicate any association with the times and locations of SURTASS LFA
sonar operations.
The commenter also states that the paper provides data of unusually
high rate of strandings in Taiwan and cetaceans showing signs of
acoustic trauma, occurring coincident with U.S. military and Chinese
submarine-utilizing exercises, amongst other things. NMFS does not
agree and believes that the commenter misstates the conclusions drawn
in the Wang and Yang (2006) paper. While the information in the paper
on the examination of the stranded animals is presented in a clear
manner, the authors state that it was impossible to determine the
reason for the stranding events. Although the authors opined that the
injuries noted in at least one stranding (beaked whale) was from
acoustic trauma, the evidence presented does not necessarily support
this as the only possible conclusion. But in any event, SURTASS LFA
sonar was not implicated in any of these events, as there was no
spacial or temporal coincidence between the strandings and the
operation of the SURTASS LFA sonar system. The relationship of at least
one of the Taiwanese stranding events to naval maneuvers is based on
conjecture, not facts.
Comment 52: It is disingenuous to state that at-sea use of LFA
sonar since the 1980s has had no impacts. The U.S. Navy has deployed
the system but instigated no program to monitor its impacts while being
used at sea. Stocks of cetaceans in areas where the system has now been
used have not had before-or after-use assessments. For all we know, the
system could have had severe impacts, but without a robust research
program it is impossible to say.
Response: NMFS does not believe that is a correct assessment.
First, NMFS recognizes that an ocean basin effects study would be
difficult to undertake, take years to carry out, and would need to
ensure that marine mammals were not being affected by other factors,
such as shifting food sources due to oceanographic parameter shifts,
natural population fluctuations, coastal whaling, incidental take in
commercial fishing operations etc. in order to be successful. Although
the Navy has not conducted real-time at sea distance sampling for
potential impacts, NMFS does not have reason to believe that LFA sonar
is having impacts sufficient to have population level effects occur.
The potential for impacts on affected marine mammal species was
partially addressed by the LFS SRP as discussed previously in Comment
47 and elsewhere in this document. Also, NMFS believes the results from
the BRS study (discussed elsewhere in this document) will provide
additional information on whether impacts on this potentially sensitive
species to anthropogenic sounds is likely.
For additional information on potential impacts on sonar sounds on
marine mammals, the Navy's ONR sponsors significant research to study
the potential effects of naval activities on marine mammals. In 2004
and 2005, Navy funded research produced approximately 65 peer-reviewed
articles in professional journals. Publication in open professional
literature through peer review is a benchmark for the quality of the
research. This ongoing marine mammal research includes hearing and
hearing sensitivity, auditory effects, dive and behavioral response
models, noise impacts, beaked whale global distribution, modeling of
beaked whale hearing and response, tagging of free ranging marine
animals at-sea, and radar-based detection of marine
[[Page 46869]]
mammals from ships. Under NMFS 2002 Final Rule, the Navy was required
to conduct research. The Navy developed and has been conducting a Long
Term Monitoring Program (LTM) Program. The program is designed to: (1)
Provide a summary of the unclassified SURTASS LFA sonar operations each
year; (2) Provide a summary of unclassified plans for the following
year; (3) Assess the efficacy of mitigation measures used during the
past year, as well as the value-added from the various LTM elements
with recommendations for improvements; (4) Provide a synopsis of LOA
reports to NMFS on estimates of percentages of marine mammal stocks
affected by SURTASS LFA sonar operations to help confirm the validity
of the impact analyses, particularly pertaining to the adequacy of
scientific information; and (5) Assess any long-term ecological
processes that may be exhibiting effects from SURTASS LFA sonar
operations, and reports or scientific papers on discernible or
estimated cumulative impacts from such operations.
Since commencing operations in 2003, the R/V Cory Chouest and the
USNS IMPECCABLE completed 40 missions from January 2003 through August
2006 under the first four LOAs. The general areas are known to the
public because they are based on the Court Injunction, published in the
Final SEIS and incorporated into the NMFS LOAs. The locations and times
of LFA sonar active operations are reported to NMFS quarterly
(classified report) as required in the first Final Rule and annual LOAs
(50 CFR Sec. 216.186). These operations, with mitigation, have
produced no known Level A takes on marine mammals as reported in the
Annual Reports (DON, 2003a; 2004a; 2005a; 2006a) and the Final
Comprehensive Report (DON, 2007a) to NMFS under 50 CFR Sec. 216.186.
To date, there have been no reported Level A harassment (injury) takes
from LFA sonar transmissions. Level B harassment is calculated based on
the times and locations of LFA sonar operations. Both are submitted to
NMFS in quarterly reports, including dates/times and locations of the
active LFA sonar missions.
Finally, even the single stranding event where LF sonar was
operating, the 1996 Greece stranding, has been addressed. According to
Cox et al. (2006) and ICES (2005), since a MF component was also used
in the Greece stranding, and MF sonar components were implicated in the
Bahamas (2000), Madeira (2002), and Canaries (2002) strandings, the LF
component in the Greece stranding was not causative.
Comment 53: The active component of the SURTASS LFA sonar
operations should not take place off the Atlantic Coast of the United
States due to impacts on the North Atlantic right whale.
Response: NMFS disagrees. The area from the coastline to the 200 m
(656-ft) isobath of the North American East Coast is protected as an
OBIA year-round which protects the North Atlantic right whale migration
route and its critical habitat from SPLs greater than 180 dB. As right
whales predominantly inhabit coastal waters, and as this OBIA extends
the 12-nm (22-km) coastal standoff to 40 nm (74 km) off Drum Inlet, NC
and 80 nm (148 km) off Long Island, NY, effects on North Atlantic right
whales are expected to be limited to, at most, some Level B
(behavioral) harassment and have a negligible impact on the species.
Marine Mammal Cumulative Impact Concerns
Comment 54: How can NMFS ignore the trend that the evidence
substantiating a wide range of anthropogenic acoustical impacts is
increasing, and also ignore that the Navy's assertions regarding the
LFA sonar's safety of operation continue to be unsubstantiated? The
trends are clear to any reasonable observer, but by ignoring contrary
evidence NMFS give the appearance of arbitrary compliance with the
Navy's assertions.
Response: While NMFS agrees that anthropogenic sources of
underwater sound in the ocean is increasing (as addressed elsewhere in
this document) with a likely increasing impact on marine mammals, NMFS
does not agree that we are ignoring contrary evidence on the impacts of
LFA sonar on marine mammals. All information to date implicates MF
sonar, not LF sonar. NMFS notes that the Navy has conducted an
investigation of stranding records and this investigation has not
indicated a relationship between LFA sonar operations and marine mammal
strandings, as addressed in more detail elsewhere in this document
(see, for example Comments 18, 31, 33, 45, 48, and 52). Therefore, if
LFA sonar is having an unknown, but serious impact on marine mammals,
that impact has not manifested itself through strandings, observable
surface behavioral patterns, or deceased marine mammals within an
operation area.
Comment 55: In its discussion of acoustic impacts, the Draft SEIS
is flawed because it dismisses cumulative and synergistic effects by
minimizing the magnitude of the potential impacts and explaining away
the unavoidable impacts with promises of ineffectual mitigation
measures.
Response: Cumulative and synergistic effects by SURTASS LFA sonar
operations are discussed in the Final SEIS (see also RTCs 4.1.9,
4.3.23, 4.3.30, 4.4.27, 4.6.2, 4.6.6, 4.6.16, 4.6.25, 4.6.27, and
4.6.29). In order to effectively evaluate potential cumulative effects
of SURTASS LFA sonar, it is necessary to draw comparisons between LFA
sonar and other sources of anthropogenic effects. As such, SURTASS LFA
sonar was compared to anthropogenic noise levels and injury/lethal
takes from other anthropogenic causes.
As discussed previously, Dr. John Hildebrand provided a comparison
of anthropogenic underwater sound sources by their annual energy output
(Hildebrand, 2005). This analysis included SURTASS LFA sonar, in which
he estimated that on an annual basis four SURTASS LFA sonar systems
would have a total energy output two orders of magnitude less than
seismic air gun arrays and one order of magnitude less than MF sonar
and super tankers. This is discussed also in more detail in the Final
SEIS (RTC 4.6.19). this information. Therefore, given that all sonars
(MF and LF included) account for only 10 percent of the marine
anthropogenic noise budget, and SURTASS LFA sonar's energy output using
4 systems is estimated at an order of magnitude less than MF sonar, the
contribution of LFA sonar to the total noise budget is trivial, and the
potential for adverse cumulative or synergistic effects as a result of
LFA sonar use are unlikely.
As stated in the Final SEIS (Subchapter 4.6.3), SURTASS LFA sonar
is not likely to cause lethal takes of marine mammals. This is
supported by the ICES (2005) report that stated, ``No strandings,
injury, or major behavioural change has yet been associated with the
exclusive use of low frequency sonar.''
Comment 56: How many vessels is the Navy planning for, and what
will be the worldwide cumulative impact of all LFA sonar operations?
Response: The Navy analyzed potential impact of deploying up to
four vessels in the Final EIS and the Final SEIS. This final rule does
not authorize more than four vessels for SURTASS LFA sonar operations.
Therefore, the number of systems has not increased over the number
initially proposed in the Final EIS and impacts to marine mammals
remain capped by the requirements that the activity have a negligible
impact over the 5-year period that the regulations are in effect.
[[Page 46870]]
The Final SEIS (Subchapter 4.6) discussed cumulative impacts,
including other military sonars, whaling, by-catch and entanglement,
ship strikes, oil and gas exploration, geophysical research, and
shipping in terms of noise. It states that, even if considered in
combination with other underwater sounds (from the aforementioned
activities), the SURTASS LFA sonar systems do not add appreciably to
the underwater sounds to which fish, sea turtles, and marine mammals
stocks are exposed. See also the Final SEIS RTCs 4.6.5, 4.6.6, 4.6.7,
4.6.8, 4.6.13, 4.6.14, 4.6.19, 4.6.20, 4.6.21, 4.6.22, and 4.6.23 for
additional information on cumulative impacts.
Comment 57: It is necessary to consider the impacts of the Navy's
training with LFA sonar alongside those of existing naval activities as
well as those of industrial and commercial activities such as fishing,
shipping, and geophysical research. The Navy seems to believe that it
can satisfy the requirement to assess cumulative impacts by cataloguing
the ways in which impacts from LFA sonar are small compared with the
totality of threats faced by marine mammals.
Response: Cumulative impacts are addressed under NEPA, not section
101(a)(5)(A) of the MMPA. Cumulative impacts on marine mammals from
activities other than SURTASS LFA sonar have been addressed in the
Navy's Final EIS and Final SEIS. The requirement under the MMPA is for
NMFS to determine (among other things) that the total taking by the
activity (not by the activity and all other activities) is having a
negligible impact on affected species and stocks of marine mammals.
This has been done in this rulemaking document. In that regard, the
Navy's LFS SRP concluded that behavioral impacts to marine mammals at
greatest risk are likely to be relatively minor, and thus are unlikely,
even in the presence of other stressors taken cumulatively, to alter
the health of the species.
In regards to stating that the impacts of LFA sonar are small
compared to other activities, as indicated by the LFS SRP, NMFS
believes that while significant changes in biologically important
behavior can occur to marine animals at significant distances from the
LFA sonar source, these impacts will affect relatively few mammals at
these distances. The Navy has assessed this potential impact by
employing the risk continuum approach as discussed in the Final EIS.
For those areas which are outside of the area covered by the risk
continuum, the received LFA sonar signal is approximately that of the
ambient environment. Thus, the signals do not add appreciably to the
ambient noise levels, and therefore do not accumulate, or collect, to
greater effects. The conclusion reached in the Final EIS (Subchapter
4.4.4) that even when considered in combination with other underwater
sounds, SURTASS LFA sonar does not add appreciably to the underwater
sounds that fish, sea turtle and marine mammals are exposed to, remains
valid.
Comment 58: Marine mammals may surface too rapidly to escape the
sounds and suffer from the bends.
Response: Tissue damage and acoustically mediated bubble growth
were examined in the Final SEIS, Subchapter 4.3.1 and RTCs 4.0.3,
4.3.12, 4.3.33, 4.3.4, 4.3.42, 4.3.43, 4.3.44, 4.3.45, 4.3.46, 4.3.47,
4.3.48, 4.3.49, 4.3.50, 4.3.51, 4.3.52, and 4.3.53.
Comment 59: What about animals that die but never surface?
Response: NMFS and the Navy recognize that absence of evidence is
not the same as no effect or impact (Final EIS, Comment 4-5.11).
However, based on the extensive analyses of the Final EIS and Final
SEIS, including the results of the LFS SRP, the results of five years
of operations and with monitoring and mitigation measures, SURTASS LFA
sonar operations have not been known and are not expected to cause any
Level A harassment (injury) or death.
Effects on Other Marine Species
Comment 60: SEAFLOW states that we have no idea what the
consequences of SURTASS LFA sonar operations will be to the many other
animals in the ocean that make up the marine habitat, but are not
identified in the MMPA, ESA, and NEPA.
Response: Under NEPA, analyses must be conducted that include the
entire marine environment that has the potential to be affected, not
just marine mammals and listed species. Please see Chapters 3 and 4 of
Final EIS and Final SEIS for a full discussion and analysis of these
potential impacts of SURTASS LFA sonar on the marine environment.
Comment 61: 90 percent of the ocean pelagic predators have been
depleted (Myers and Worm, 2003).
Response: Myers and Worm (2003) discuss the decline in large
predatory fish biomass. However, the decline is due to industrialized
fisheries, not due to SURTASS LFA sonar. Recent studies have shown that
SURTASS LFA sonar will likely have a negligible effect on fish, as
stated in Subchapter 4.1 of the Final SEIS.
Comment 62: In addition to the target species, a wide variety of
marine species can be found within the exposure area, including other
marine mammals, sea turtles, invertebrates, teleost and elasmobranch
fish, and sea birds. The proposed activity is not designed to expose
just one target species. WSPA notes that the sounds to be administered
will have unknown (and unmonitored) effects on other animals (e.g.,
prey species) that may occur in the exposure area thereby subjecting
the identified ``affected species'' to additional indirect effects.
Response: When using SURTASS LFA sonar, the Navy's target is to
identify potentially hostile submarines, it does not ``target species''
during its operations. The Navy applied for an authorization for the
incidental taking of those marine mammal species specified in the
application and analyzed impacts to all potentially affected species
(including marine mammals, sea turtles, invertebrates, fish, sharks,
and sea birds) in Chapters 3 and 4 of the Final EIS and SEIS.
Comment 63: WSPA is concerned that the impacts of the proposed
activities could have a more damaging effect on younger animals in the
exposed groups.
Response: See the Navy's response in the Final EIS, Comment 4-
4.2.4. It states the primary factors increasing risk to a marine
species would be a more pelagic and deeper distribution of animals in
the water column. No clear examples were identified during the analyses
in which juveniles rather than adults met these criteria. For marine
mammals, this analysis is further supported by the LFS SRP. Further,
coastal marine mammal species would likely receive lower SPLs thereby
further protecting calves and juveniles from offshore LFA sonar
operations (but not from other coastal anthropogenic sounds).
Impacts on Marine Mammal Habitat
Comment 64: The U.S. Navy has not provided any evidence that the
SURTASS LFA sonar system is harmless to the marine environment. The
Draft SEIS offers no new information to suggest that SURTASS LFA sonar
will not harm marine life.
Response: NMFS believes that the Final SEIS and the Final EIS
contains a full analysis of SURTASS LFA sonar and the effects on the
marine environment. The potential for SURTASS LFA sonar operations to
cause harm to marine invertebrates is discussed also in SEIS RTC 3.2.5
while impacts to marine fish are discussed in SEIS RTC 4.1.4, and
impacts to marine mammals are provided in RTCs referenced in SEIS RTC
4.3.6.
[[Page 46871]]
Since the Final EIS was published in early 2001, there has been
additional research published in a peer reviewed journal that supports
the 180-dB criterion for injury as being a conservative level for
assessing potential injury to marine mammals. Laurer et al. (2002)
exposed rats to 5 minutes of continuous high intensity, low frequency
(underwater) sound (HI LFS) either at 180 dB SPL re 1 microPa at 150 Hz
or 194 dB SPL re 1 microPa at 250 Hz, and found no overt histological
damage in brains of any group. Also, blood gases, heart rate, and main
arterial blood pressure were not significantly influenced by HI LFS
suggesting that there was no pulmonary dysfunction due to exposure.
This published paper was based on work performed in support of
Technical Report 3 of the SURTASS LFA sonar Final EIS.
From 2003 to 2006, the University of Maryland conducted a series of
studies to test the effects of high intensity LFA sonar on fishes.
These studies, which tested the effects of an actual LFA sonar
transducer, examined the changes in hearing capabilities, changes in
the mechanical structures of the ear, and the effects on other organ
systems, including the swim bladder and brain. Detailed information on
the experiment is provided in the Draft SEIS (pp. 4 10 to 4 22). Popper
et al. (2007) shows that there is no permanent hearing loss in either
species studied (the rainbow trout (Onchorynchus mykiss), a close
relative of endangered and listed salmonid species, and the channel
catfish (Ictalurus punctatus), an example of a hearing specialist).
Both species showed some temporary hearing loss. This was not of great
magnitude, and hearing returned to normal within a day or so after
exposure. Results suggest no effect on other organ systems; for
example, the swim bladder in fish exposed to the LF sonar signal was
completely intact. Moreover, all animals survived the experiments and
none died, even several days after exposure. The sound levels (up to
193 dB rms re: 1 microPascal2 at 196 Hz RL) used in these experiments
approached those that fish would encounter very close to an active LFA
sonar source array (within 200 m (656 ft)). However, the exposure
during experiments was very likely more substantial (e.g., experimental
exposure to either 324 or 628 seconds) than any a fish would encounter
in that the fish were exposed to multiple replicates of very intense
sounds, whereas any fishes in the wild would encounter sounds from a
moving source, and the successive emissions from the source would
decrease in intensity as the ship moved away from exposed fish.
To date, no evidence has been provided that supports the hypothesis
that ``SURTASS LFA sonar can do great harm to fish stocks.'' The SEIS
discussed several studies which examined fish catch rates before and
after presentations of sounds from seismic air guns (SEIS Subchapter
4.1.1.4). These studies noted a temporary decline in catch rate for
trawls and longlines. The Navy points out that the exposure to seismic
air guns was over a much longer time frame than those projected for LFA
sonar. Moreover, there are significant acoustic differences between the
impulsive sounds of air guns and the coherent sounds of LFA sonar.
Thus, at this time it is scientifically premature to extrapolate from
these studies to LFA sonar. Since exposure times to LFA sonar is
significantly shorter than to seismic air guns, it is reasonable to
suggest that any behavioral effects from LFA sonar signals will be
minor and transitory.
Other Marine Life Concerns
Comment 65: The commenter is concerned with the effects of sound
energy on marine life. They request we promulgate restrictions which
will protect marine mammals from hazards. These restrictions need only
be ones of common sense, such as: (1) Avoiding known sensitive feeding,
breeding or rearing grounds and migration routes within federally
designated critical habitat areas when conducting naval exercises; (2)
Using passive technology to determine the presence of marine mammals
and avoid using active sonar while in their presence, as defined by the
distance necessary to avoid harm; (3) Cease active sonar operations if
marine mammals are observed, particularly if observations are
compatible with fear, stress displays, or abandonment of young; (4) Not
using active sonar in confined, shallow, coastal waters where marine
mammals are likely to congregate; and (5) Not exceeding the level sonar
energy which has been scientifically documented to be below the
threshold of injury to the exquisitely sensitive organs of hearing.
Response: NMFS (and the Navy) agree with these mitigation measures,
which are all already in place. Please see Monitoring and Mitigation
sections in this rule for details.
Mitigation Concerns
Comment 66: The Navy promises only to turn off LFA sonar if they
spot or detect whales in a very small area around the ships. Since the
impacts of underwater sound, both to do physical harm to whales and
also to disrupt and harass whales' and dolphins' own communication,
feeding, and orientation, cover enormous distances, these mitigation
measures are too paltry to protect the health of whales and dolphins.
Response: Implementing a shutdown zone of approximately 2 km (1.1
nm) around the LFA sonar unit will ensure that no marine mammals are
exposed to an SPL greater than about 174 dB. This is significantly
lower than the 180-dB used for other acoustic projects for protecting
marine mammals from injury. As shown in this document and elsewhere,
SURTASS LFA sonar is not expected to cause physical injury to marine
mammals below 180 dB RL. The 180 dB injury criterion is based on
scientific documents and research, which are provided in the Final EIS
(Subchapter 1.4.2.1, and Chapter 10 and RTCs 4 4.9, 4 5.1, 4 6.1, 4
6.13, and 5 2.1). In NMFS' 2002 Final Rule for the operation of SURTASS
LFA sonar (67 FR 46721 89), we discussed the 180-dB criterion (see RTC
SIC44 through SIC49).
Since the Final EIS was published in early 2001, there has been
additional research published in a peer reviewed journal further
supports the 180-dB criterion for injury as being a conservative level
for assessing potential injury to marine mammals. As described
elsewhere in this document, Laurer et al. (2002) research supported the
findings in Technical Report 3 of the SURTASS LFA sonar Final
EIS. Also, the potential for SURTASS LFA sonar to cause harm to marine
mammals and the validity of the 180 dB injury threshold for SURTASS LFA
sonar are discussed in the Final SEIS (RTCs 4.0.1, 4.0.2, 4.0.3, 4.3.1,
4.3.2, 4.3.7, 4.3.8, 4.3.9, 4.3.10, and 4.3.12).
Regarding strandings, the best available scientific evidence
supports a conclusion that beaked whales are the primary species of
concern, and that mid-frequency active sonar, not LFA sonar, when
combined with other factors, is the sonar most likely implicated. Also,
most odontocetes have relatively sharply decreasing hearing sensitivity
below 2 kHz. If a cetacean cannot hear a sound or hears it poorly, it
is unlikely to have a significant behavioral impact (Ketten, 2001).
Therefore, it is unlikely that LF transmissions from LFA sonar would
induce behavioral reactions from animals that have poor LF hearing,
such as beaked whales. While it is highly unlikely, the sounds could
damage tissues even if the animal does not hear
[[Page 46872]]
the sound, but this would have to be occur within the 180 dB sound
field (within 1,000 m (3,280 ft)) of the transmit array. The likelihood
of a marine mammal entering the 180 dB sound field is considered highly
unlikely due to the detection effectiveness of the Navy's HF/M3 sonar.
Therefore, NMFS believes that the tripartite monitoring program has a
high probability of detecting the presence of marine mammals prior to
potential injury. This will be discussed later in this document.
Finally, NMFS discusses the potential for masking marine mammal
communications and hearing elsewhere in this document.
Comment 67: The Federal Court that struck down the Navy's earlier
EIS wrote: `` endangered species, including whales, listed salmon and
sea turtles, will be in LFA sonar's path. There is little margin for
error without threatening their survival.'' The court therefore urged
the Navy to consider protective measures such as wide coastal exclusion
zones, more effective surveys for whales before sonar exercises, shut
down procedures for fish, and the use of training areas that present
less risk to marine life. The Navy's proposed authorization rejects
each of these ideas.
Response to the first point: The choice of 46 km (25 nm) was
selected because it was just over twice the current coastal exclusion
restriction, and seaward of the hypothetical shelf break for all three
shelf cases examined in its analysis. The Philippine Sea dual criteria
alternative referred to by the commenter (111 km (60 nm) from the coast
or 56 km (30 nm) seaward of the 200 m (656 ft) isobath, whichever is
greater) was negotiated in a mediated settlement. The Final EIS
analysis was based on a coastal geographic restriction of 22 km (12
nm); whereupon it was incorporated into the Navy's ROD, NMFS's 2002
Final Rule and subsequent LOAs. In the Navy's good faith attempt to
respond to a Court identified deficiency relating to the number of
alternatives considered, additional alternatives were analyzed in the
Draft SEIS, including more than doubling the coastal standoff range.
The results, which are too complex to discuss in detail here, are
summarized in Final SEIS Subchapter 4.7.6. This analysis indicates that
increasing the coastal standoff range decreases exposure to higher RLs
for the concentrations of marine mammals closest to the shore (shelf
species) but does so at the expense of increasing exposure levels for
shelf break species and pelagic marine mammal species. Increasing the
range to 56 km (30 nm) or even 111 km (60 nm) (criteria from the
Permanent Injunction) would not make a significant difference in the
outcome. However, coastal shelf areas, in many cases, are already
excluded. The Final SEIS Table 2-4 delineates OBIAs that are also a
coastal shelf exclusion zones. For example, the North American east
coast exclusion zone includes all shelf waters landward of the 200-m
(656-ft) isobath between 28 deg N to 50 deg N latitude, west of 40 deg
W longitude. This is a year-round restriction and encompasses the
Northern Right Whale Critical Habitat, the Stellwagen Bank National
Marine Sanctuary (NMS), the Monitor NMS, and the Gray's Reef NMS.
Response to the 2nd Point. The Stipulation Regarding Permanent
Injunction issued on October 14, 2003, by the U.S. District Court for
the Northern District of California, as agreed to by the parties stated
the Navy was not required to conduct ``pre operation surveys'' as
described in the Court's Opinion and Order. In response to the Opinion
and Order, the Navy provided an evaluation of the use of small boats
and aircraft for pre operational surveys in the Draft SEIS Subchapter
5.4. That evaluation demonstrated that small boat and pre operational
aerial surveys for SURTASS LFA sonar operations are not practicable,
not effective, may increase the harassment of marine mammals, and are
not safe for the observers. In addition to small boats, small aircraft
surveys were also suggested. This issue was addressed in SEIS
Subchapter 5.4 which provided a detailed discussion of why aerial and
small craft surveys were not considered a viable mitigation option. The
possible harassment of marine mammals from these surveys was only one
factor in this consideration. Please see SEIS RTCs 5.4.1, 5.4.2, and
5.4.3 for additional information.
Comment 68: The Navy proposes to retreat from the mitigation
measures it currently uses to protect marine life in its operation of
LFA sonar today, including wide exclusion zones of 30 to 60 nm (55.6-
111 km), 1-km (0.43-nm) buffer zone, 330 Hz limit on frequency. It
shrinks the safety zone around transmitting ships, removing three
quarters of the buffer currently required by NMFS. It eliminates the
restrictions imposed by NMFS to operate the system only at frequencies
below 330 Hz. The MMPA's mitigation standard has not been met, nor has
the agency prescribed mitigation sufficient to make an affirmative
finding of negligible impact [and] the Navy's new permit application *
* * fails to adopt or severely shortchange each of these mitigation
measures.
Response: Wider exclusion zones are discussed in Comment 67. The
one-km (0.54 nm) buffer zone was an interim operational restriction
added by NMFS in the 2002 Final Rule. An analysis by the Navy
demonstrated that the removal of this restriction will not appreciably
change the percentage of animals potentially affected. However, NMFS
has again included the one-km (0.54 nm) buffer zone in its rule for
SURTASS LFA sonar to further protect against marine mammals entering
the 180 dB isopleth.
The 330-Hz frequency restriction was an interim operational
restriction added by NMFS in the 2002 Final Rule to preclude the
potential for injury to marine mammals by resonance effects. That
restriction was based on a statement made by Dr. Darlene Ketten, an
expert on the functional morphology of marine mammal hearing, in her
testimony before the Subcommittee on Fisheries Conservation, Wildlife
and Oceans of the House Committee on Resources on October 11, 2001
(Ketten, 2001). The Navy's Final SEIS states that the NMFS acoustic
resonance workshop ruled out resonance, but stated that the report
provided part of the evidence required by NMFS that resonance and/or
tissue damage from LFA sonar transmissions were unlikely to occur in
marine mammals at levels below 190 dB (Final SEIS Subchapter 2.5.1).
DOC (2002) states that it seemed unlikely that acoustic resonance in
air spaces played a primary role in tissue trauma in the Bahamas and
other events. Nevertheless, they suggested continued research. While
the Marine Mammal Commission workshop did not discuss in detail the
results of the NMFS acoustic resonance workshop, it endorsed three
recommended areas of study: (1) Beaked whale lung resonance throughout
the dive profile; (2) potential for other organs and structures to be
affected by resonance; and (3) possibility that animals experience
tissue shear (Cox et al., 2006). At this time, there is no information
available that supports an increase in the probability of LFA sonar to
cause injury to marine mammals through resonance in the frequency range
of 330 to 500 Hz. The frequency requirements for the CLFA sonar to be
installed onboard the VICTORIOUS Class vessels are above 330 Hz, but
still within the 100 to 500 Hz range as stated in both the Final EIS
and Final SEIS. After conducting a full review of resonance in its
Final SEIS, the Navy concluded, and NMFS agrees, that effects from
resonance are unlikely and that there is no need to retain the 330-Hz
restriction.
[[Page 46873]]
A full analysis of the mitigation measures was conducted in the
Final SEIS, Chapter 5. Further, mitigation measures have been discussed
in this document. NMFS believes that use of SURTASS LFA sonar
consistent with these regulations meets the MMPA mandate that takings
be reduced to the lowest level practicable.
Comment 69: The Navy's take application proposes to abandon or
severely curtail existing protections. Every one of its alternatives
would allow the Navy to train with LFA sonar throughout 75 percent of
the world oceans. It withdraws from a court-ordered extended coastal
exclusion zone, reverting to the originally proposed (and rejected)
zone of 12 nm (22 km).
Response: Please see previous responses on the comment regarding
LFA sonar operation in 75 percent of the world's oceans. As for the
coastal exclusion zone, in the Navy's good faith attempt to respond to
a court-identified deficiency, additional alternatives were analyzed in
the Draft SEIS, including more than doubling the coastal standoff
range. The results summarized in Final SEIS Table 4.7.7 indicate that
increasing the coastal standoff range does decrease exposure to higher
RLs for the concentrations of marine animals closest to the shore
(shelf species) but does so at the expense of increasing exposure
levels for shelf break species and pelagic species. Increasing the
range to 56 km (30 nm) or even 111 km (60 nm) would not make a
significant difference in the outcome.
In addition, if the Navy does operate at 12 nm from the coast,
there are potential benefits over operating farther from shore.
Analysis of the geometry, bathymetry, sound propagation, and animal
densities in a variety of sample areas revealed that the overall risk
to marine mammals is lower when SURTASS LFA sonar is operated at 12 nm
from shore than when it is operated at 25 nm. First, a smaller volume
of ocean is ensonified. For example, the estimated volume exposed to a
received level of 155 dB decreases by 21%. This is due, in part, to
shallower water depths closer to shore. In addition, in the majority of
scenarios studied, when all biological factors were taken into account,
including marine mammal densities, the risk incurred by moving closer
to shore decreased or remained the same. Given the Navy's stated need
to have the flexibility to use the system closer to shore if training,
testing, or military operational demands required it, and in light of
evidence demonstrating that operation at 12 nm from shore created less
impact on marine mammals than a larger coastal exclusion zone, NMFS
determined that a smaller coastal exclusion zone was warranted and
consistent with its obligation under the MMPA to prescribe ``other
means of effecting the least practicable adverse impact,'' while taking
into account ``personnel safety, practicality of implementation, and
impact on the effectiveness of the military readiness activity.''
Naturally, if the Navy's operational needs did not require it to take
advantage of the additional flexibility offered by the narrower coastal
exclusion zone, then the potential benefits would not be realized, and
the impacts would remain the same as before under the broader coastal
exclusion zone.
Comment 70: The Draft SEIS does not state at what distance from the
source the 180 dB RL isopleths will occur, but in the mitigation
section repeatedly refers to the ``mitigation zone.'' Clarification of
the distance from the source at which a RL of the 180 dB is expected
should be included.
Response: The distance to the 180-dB isopleth is given in the Final
EIS on pages 2-14, 2-18, and 5-1, which were incorporated by reference
into the Final SEIS. Under normal operating conditions, this zone will
vary from 0.75 to 1.00 km (0.4 to 0.54 nm) from the source array,
ranging over a depth of approximately 87 to 157 m (285 to 515 ft). This
information was added to the appropriate section in Final SEIS Chapter
2. In addition, NMFS has continued the requirement for the Navy to
establish a ``buffer'' zone extending an additional 1 km (0.54 nm)
beyond the 180-dB isopleth. Any marine mammals detected within the 180-
dB zone or the 1-km (0.54-nm) buffer zone will result in a shut-down of
the SURTASS LFA sonar array and a power-down of the HF/M3 sonar so that
the marine mammal(s) detected are not subject to LFA sonar sounds in
excess of 180 dB.
Comment 71: In regards to monitoring, the Draft SEIS does not state
how much training these personnel will receive, how their level of
expertise will be measured, the amount of refresher training that will
be done, or if these ship personnel will have to perform other duties
when they are conducting observations. The Draft SEIS also does not
state how many trained marine mammal observers will be used at any one
time or where they will be positioned on the ship, except at the
topside. SURTASS LFA sonar should cease during hours of darkness when
the chances of spotting a marine mammal or turtle approximate zero.
Response: As stated in NMFS' 2002 Final Rule (RTC MOC 8), personnel
trained in detecting and identifying marine animals will make
observations from the SURTASS LFA sonar vessel. At least one observer,
qualified by NMFS, has trained, tested and evaluated other visual
observers. Visual observation effectiveness estimates will be provided
to NMFS in accordance with LOA reporting requirements.
Because of the limitations of both passive acoustic and visual
monitoring, the Navy developed the HF/M3 sonar to provide effective 24-
hour, all-weather active acoustic monitoring of an area of
approximately 2-km (1.1 nm) radius from the array. The HF/M3's
detection effectiveness is calculated at 95 percent standing alone and
is not dependent on the time of day. For further information see
sections on mitigation and monitoring in this rule and the Final SEIS,
Chapter 5, and the Navy's Final Comprehensive Report, Chapter 2.
Comment 72: The use of passive acoustic monitoring to listen for
vocalizing marine mammals as a complementary detection method to visual
observation is a good idea. However, to use the SURTASS array for this
purpose would limit detections to those animals vocalizing within the
bandwidth of the system. Most marine mammals would therefore not be
detected.
Response: This topic was addressed in Final EIS, Subchapter
4.2.7.1. In calculating the effectiveness for the various monitoring
systems for purposes of the Final EIS analyses, the passive monitoring
component of the three-part monitoring system was estimated at 0.25, or
25 percent. Because of the limitations of both passive acoustic and
visual monitoring, the Navy developed the HF/M3 sonar to provide 24-
hour, all weather active acoustic monitoring.
Comment 73: The protocol described in the Draft SEIS for reacting
to a detected animal is based on a subjective and mission-impacting
judgment call by the array technician who has to decide if the detected
animal might be impacted by the SURTASS LFA sonar. In all likelihood,
such decisions are unlikely to be made in favor of the animal when the
consequence is the shut down of operations and chance of incurring the
disfavor of peers and superiors.
Response: NMFS has no reason to question that the Navy would not
fully comply with the mitigation and monitoring requirements for the
SURTASS LFA sonar operations operations which mandate non-operation or
shutdown of the sonar source if a marine mammal is detected
[[Page 46874]]
within 2 km of the source. For further information on mitigation and
monitoring, please see the Final SEIS, Chapter 5, and the Final
Comprehensive Report, Chapter 2.
Comment 74: The Draft SEIS does not state what the full power
levels of the HF/M3 will be but merely states that RLs will not exceed
180 dB and does not give distances from the HF/M3 source. A mitigation
measure that adds more noise to the environment is illogical.
Response: The general operating characteristics of the HF/M3 sonar
have been provided in the Final EIS (p. 2-17). The source level is 220
dB re 1 microPascal at 1 m. HF/M3 sonar testing and effectiveness are
discussed in the Final EIS (pp. 2-19 through 2-22) and the Final SEIS
RTC 5.2.20. As a mitigation measure, the HF/M3 sonar is ramped up from
180 dB SL to full power over 5 minutes in 10 dB increments (Final SEIS,
Subchapter 5.2.3).
There is recent scientific evidence that sonars, similar to the HF/
M3, which are in common use in the fishing and maritime industries, do
not harm marine life. In a recently published paper, Benoit-Bird et al.
(2006) examined the hypothesis that marine mammals acoustically stun
their prey by exposing three species of fish commonly preyed upon by
odontocetes to pulsed signals at 18 kHz, 55 kHz, and 120 kHz with
exposure levels from 193 dB (peak-to-peak), 208 dB (peak-to-peak), and
213 dB (peak-to-peak), respectively. They observed: (1) No measurable
changes in the behavior for any of the species during the exposures;
(2) no noticeable change in swimming activity; (3) no apparent loss of
buoyancy; (4) no movement away from the transducer; and 95) no
mortality. Despite the use of signals at the maximum source levels
recorded for odontocetes clicks, the researchers could not induce
stunning or even disorientation in the fish tested.
In addition, a requirement to ramp-up the HF/M3 ensures that marine
mammals are detected by the HF/M3 sonar at the lowest sound level
possible. If a marine mammal is detected during ramp-up within the 180-
dB sound field or 1-km (0.54-nm) buffer zone, further increases in
power are not initiated until the animal is no longer detected. At that
time, ramp-up would continue unless that animal, or another, was
detected. The HF/M3 sonar effectiveness has been discussed in a report
by Ellison and Stein (2001), which is available to the public on the
SURTASS LFA sonar Web site at http://www.surtass-LFA sonar-eis.com/
Download/index.htm. In addition, a paper on this subject was presented
at the 2001 Acoustical Society of America meeting (Stein et al., 2001).
For additional information please see Final EIS Subchapter 4.2.7.3
and RTCs 5-2.4, 5-2.11, 5-2.12, 5-2.13, 5-2.19, 5-2.21, and 5-2.22; and
NMFS 2002 Final Rule RTCs MOC10, MOC12, MOC14, and MOC17.
Comment 75: The commenter is concerned by the mention of the use of
a high frequency sonar system to detect whales. Has this undergone an
appropriate environmental assessment? Has a take authorization been
issued for animals that this might impact? Have the cumulative impacts
of low and high frequency systems being used in conjunction been
considered?
Response: As stated in the SURTASS LFA sonar Final EIS (RTC 5-
2.21), the HF/M3 sonar is basically a fish-finder type sonar with
similar frequency ranges and power output as many commercial fish
finder sonars. These sonar types are commercially available and used
worldwide, and are unregulated. The potential impacts of the HF/M3
sonar are discussed in Subchapter 4.2.7.3 in the Final EIS. If a marine
mammal is detected during ramp-up within the 180-dB sound field or the
1-km (0.54-nm) buffer zone, further increases in power are not
initiated until the animal is no longer detected. At that time, ramp-up
would continue unless that animal, or another, was detected. It was
concluded that the impacts of the HF/M3 sonar when utilized using the
above supplemental safety measures would have negligible impacts.
Therefore, the environmental documentation requirements for the HF/M3
sonar have been met by the Final EIS. This analysis from the Final EIS
remains valid. Additionally, as required by the first Final Rule, the
HF/M3 has undergone further analyses of effectiveness in the Navy's
Final Comprehensive Report (2007a) and, to remain in compliance with
this Final Rule, the Navy is required to analyze the HF/M3 over the
next five years.
The cumulative impacts of LFA sonar and other military and
commercial sonars used in conjunction have been addressed in the SEIS
Subchapter 4.7.1. Because of the differences in the signal
characteristics between LFA sonar and the HF/M3 sonar, synergistic
effects are unlikely to occur. The HF/M3 is discussed further in
Comment 74.
Comment 76: NMFS must establish that LFA sonar operational
mitigations are adequate prior to granting this Authorization. No one
has proven that the LFA sonar visual and acoustic detection mitigations
actually work under realistic scenarios. There has been enough time to
produce something of value; why has NMFS not required the Navy to
validate detection mitigations, and instead accepted assertions and
models? There have been no directed scientific research efforts to
validate that the LFA sonar mitigations reliably detect marine mammals
and turtles within the buffer zone under realistic scenarios and
conditions, and no research to confirm that the LFA sonar operations
are modified by delays or shutdowns whenever individuals of species of
concern are actually within or about the enter the zone? The Commission
expressed similar concerns in its July 24, 2007 letter. This lack of
proof renders baseless the Navy's assertions of adequate shutdowns
during yearly operations, because no one knows how many cetaceans and
turtles were actually inside the buffer zone during previous LFA sonar
operations, no one studied what happened over a reasonable time to
those that were within a kilometer, and no one studied actual
behavioral impacts over wider ranges and times.
Response: NMFS and the Navy have stated the limitations of the
visual and passive acoustic detection systems previously. However, as
stated in Subchapter 2.3.2.2 of the Final EIS, the HF/M3 sonar has
undergone both qualitative and quantitative assessments of the system's
ability to detect marine animals of various sizes and was verified in
seven sea trials between 1998 and 2000. In addition, LFA sonar has been
operating since 2003 in a restricted area in the northwestern Pacific
Ocean with a total of 470 hours of transmit time under the first four
LOAs (DON, 2007). These operations, with mitigation, have produced no
known Level A takes on marine mammals. NMFS regulations require the
Navy to delay or suspend operation of SURTASS LFA sonar whenever a
marine mammal is detected within 2 km (1.1 nm) of the sonar source by
any means. NMFS has no reason to believe that the Navy has not complied
with these requirements and, in fact, the Navy's reports indicate that
use of the sonar has been delayed or suspended on many occasions in
compliance with the regulations. Further information on mitigation
effectiveness is provided in the Annual Reports required under the LOAs
(DON 2003, 2004, 2005, 2006, and 2007). Additional analyses have been
provided in the Navy's Final Comprehensive Report (DON, 2007). Finally,
NMFS is unaware of a practical way to validate the number of animals
underwater and outside the LFA sonar mitigation (shutdown) zone to
verify the number of Level B takes by harassment. We are
[[Page 46875]]
also unsure whether the commenter is recommending research on the
number of Level A (injury) harassment takes which (unless surrogate
species are used) have the potential to result in injury to marine
mammals during the course of research on the effectiveness of the tri-
partite mitigation monitoring program. This ethical concern is a reason
why the LFS SRP was limited to SPLs below 160 dB.
An evaluation of the effectiveness of the monitoring and mitigation
measures has been provided to NMFS in the Final Comprehensive Report
(DON, 2007) submitted under 50 CFR 216.186(c). This report is available
to the public (see ADDRESSES). Estimated marine mammal densities are
determined for each potential LFA sonar operations area proposed in the
annual requests for LOAs under the current regulations. The 180-dB
safety and 1-km (0.54-nm) buffer zones were monitored at all times
during LFA sonar active transmissions as required by NMFS 2002 Final
Rule (50 CFR 216.185 and 50 CFR 216.186) and the conditions of the LOAs
as issued. In addition, available stranding data from the operating
areas are continuously reviewed, and no strandings have coincided
spatially or temporally with LFA sonar operations.
Comment 77: Why doesn't NMFS challenge detection methods as being
compromised during a significant portion of the LFA sonar's operating
envelope? Visual detections of marine turtles near one kilometer are
unlikely during flat calm conditions, experts testify that only a very
small percentage of nearby beaked whales will ever be seen and all
visual detections become moot with medium sea states, night, and some
weather operations.
Response: NMFS and the Navy agree that visual monitoring has a low
detection probability. The Navy stated in several documents, including
its Final Comprehensive Report (Navy, 2007) that the detection
probability from visual monitoring is approximately 9 percent. For this
reason, the Navy uses an active acoustic monitoring system, the HF/M3.
The HF/M3 sonar was specifically developed to improve detection of
marine mammals and potentially sea turtles, through active acoustic
detection, ensuring that they are not within the LFA sonar mitigation
zone during SURTASS LFA sonar transmissions. It provides 24-hour
detection for marine animals, even during poor visibility conditions.
Analysis and testing of the HF/M3 sonar operating capabilities
indicates that this system substantially increases the chances of
detecting marine mammals (and possibly sea turtles) within the LFA
sonar mitigation zone (i.e., inside the 180-dB safety and 1-km buffer
zone sound fields). The probability of detection of various marine
mammals is presented in the Final EIS, Figure 2-5. The potential for
SURTASS LFA sonar to cause harm to marine mammals and the validity of
the 180-dB injury threshold for SURTASS LFA sonar are discussed in
Final SEIS (RTCs 4.0.1, 4.0.2, 4.0.3, 4.3.1, 4.3.2, 4.3.7, 4.3.8,
4.3.9, 4.3.10, and 4.3.12).
Comment 78: Acoustic detection requires that the marine animals in
the path of the buffer zone make sounds, but current research does not
validate that they do so sufficiently for anyone to expect to detect
even a small percentage of animals included in, or in the path of the
buffer zone. Can NMFS deny that the total acoustical output from the
LFA sonar vessel and associated vessels may cause acoustically active
animals to be more silent, rendering the acoustic monitoring moot?
Response: In calculating the effectiveness for the various
monitoring systems for purposes of the Final EIS analyses, the passive
monitoring component of the tri-partite monitoring system was estimated
at 0.25, or 25 percent. Because of the limitations of both passive
acoustic and visual monitoring, the Navy developed the HF/M3 sonar to
provide 24-hour, all weather active acoustic monitoring. The HF/M3 was
tested and the results were discussed and analyzed in the Final EIS and
in Technical Report 3 (Ellison and Stein, 2001). This topic is also
addressed in Final EIS Subchapter 4.2.7.1.
In regards to animals changing their vocal behavior, the following
response is a summary of the information provided in the Final EIS.
Given that the LFA sonar sound source can be detected at
moderate to low levels over large areas of the ocean, there was
concern at the initiation of the NEPA process in 1996 that there was
the potential for large percentages of species stocks to be exposed
to moderate-to-low received levels. If animals are disturbed at
these moderate-to-low exposure levels such that they experience a
significant change in a biologically important behavior, then such
exposures could potentially have an impact on rates of reproduction
or survival. Knowing that cetacean responses to LF sound signals
needed to be better defined using controlled experiments, the Navy
helped develop and supported the three-year LFS SRP beginning in
1997. This field research program was designed to address three
important behavioral contexts for baleen whales: (1) blue and fin
whales feeding in the southern California Bight, (2) gray whales
migrating past the central California coast, and (3) humpback whales
breeding off Hawaii. Taken together, the results from the three
phases of the LFS SRP do not support the hypothesis that most baleen
whales exposed to RLs near 140 dB would exhibit disturbance behavior
and avoid the area. These experiments, which exposed baleen whales
to RLs ranging from 120 to about 155 dB, detected only minor, short-
term behavioral responses. Short-term behavioral responses do not
necessarily constitute significant changes in biologically important
behaviors.
These results have been supported by recent, peer reviewed papers.
Croll et al. (2001a) studied the effects of anthropogenic LF noise
(SURTASS LFA sonar) on the foraging ecology of blue and fin whales off
San Nicolas Island, California. Overall, the whale encounter rates and
diving behavior appeared to be more strongly linked to changes in prey
abundance associated with ocean parameters than to LFA sonar
transmissions. In some cases, whale vocal behavior was significantly
different between experimental and non-experimental periods. However,
these differences were not consistent and did not appear to be related
to LF sound transmissions. At the spatial and temporal scales examined,
Croll et al. (2001) stated that they found no obvious responses of
whales to a loud, anthropogenic, LF sound.
Both Miller et al. (2000) and Fristrup et al. (2003) published on
the results of tests conducted with male humpback singers off Hawaii in
which they evaluated variation in song length as a function of exposure
to LF sounds. In spite of methodological differences, the results of
both studies indicated that humpback whales slightly increased their
songs in response to LF broadcasts. Fristrup et al. (2003) found that
the fraction of variation in song length that could be attributed to LF
broadcast was low and concluded that the effects of LF broadcast did
not impose a risk of dramatic changes in humpback whale singing
behavior that would have demographic consequences. Therefore, it is not
believed that the use of active acoustics will dramatically change the
vocalizations of acoustically active animals.
Comment 79: Does NMFS believe that the geographical mitigations are
the only areas the LFA sonar may cause significant effects? If previous
LFA sonar operations actually were conducted in areas with near-zero
marine animals of concern, future operations certainly will be in the
areas with significant populations. Again, without adequate detection,
how can NMFS know that takes will not be excessive?
[[Page 46876]]
Response: As noted in the Final SEIS (Subchapter 2.5.2.1), for the
purposes of obtaining an LOA, SURTASS LFA sonar operations are planned
in advance for areas with reduced risk by avoiding areas of high marine
life concentrations to the greatest extent feasible considering
national security tasking. This process is detailed in the Final SEIS
(Subchapter 4.4). Also, please see RTCs CSI-1, 2, 3, and 4 in this
document. However, it is erroneous to say that the area in which
SURTASS LFA has been operated for the last five years had ``near-zero''
marine animals. There are virtually no parts of the ocean that can be
accurately described as ``oceanic deserts'' devoid of marine life.
While some areas are better studied than others, it would be a mistake
to assume that simply because data is lacking on marine mammal
abundance the area is devoid of marine mammals. Thus, in selecting
areas where the Navy will and will not operate LFA sonar, we must rely
on what is known about marine mammal concentrations and attempt to
avoid them, continue to fill knowledge gaps through additional
research, and recognize that, by necessity, we are regulating in a
dynamic area of science.
Comment 80: Without adequate detection, how can NMFS know that
takes will not be excessive?
Response: As discussed previously in this document, NMFS believes
that the tri-partite mitigation measures, particularly the HF/M3 sonar
will be capable of detecting over 95 percent of all marine mammals
within the 180 dB range. In addition, since detection is excellent out
to the edge of the buffer zone, marine mammal detection will be more
than adequate and will prevent Level A injury and mortality. Also
please see the Navy's Final Comprehensive Report (DON, 2007).
Comment 81: Because there has been no participation by scientific
experts on any LFA sonar mission cruises over several years there is no
reliable documentation of observed and probably numbers of cetaceans
and turtles that may have been within the LFA sonar's buffer zone,
general surrounding area, or track line.
Response: According to the Navy, utilization of third-party marine
biological visual observers is not feasible. First, there is no
available berthing for additional personnel on the LFA sonar vessels.
To accommodate visual observers(s), it would require the reduction of
the number of operational personnel on the vessel, which would reduce
mission effectiveness. Moreover, because of the nature of the missions,
third-party observers would require security clearances. Although it is
possible for these personnel to obtain the proper security clearances,
the time and cost of applying for security clearances for these
individuals is high. Please see NMFS' 2002 Final Rule (RTC MOC32) for
further discussion.
However, while third-party observers during military operations are
not practicable, NMFS has recommended certain research projects be
undertaken by the Navy, during which non-Navy scientists would be
participants.
Comment 82: The Navy fails to consider additional mitigation
measures that would mitigate LFA sonar's impact on marine species,
including, the Navy's failure to extend the coastal zone and instead
disputes that greater exclusion zones would be beneficial to marine
species. The Navy has failed to present sufficient modeling and
analysis.
Response: In order to answer the question of whether a standoff
range farther from the coast would, in fact, generate fewer marine
mammal takes, a generic analysis was performed (Final SEIS Subchapter
4.7.6). This analysis was not portrayed in the Final SEIS as a modeling
effort, but as a ``generic analytical methodology for coastal standoff
range comparison'' as clearly stated in the Final SEIS. As further
stated, ``The methodology used to assess the change in potential
impacts to marine animals was designed to utilize several sets of
simplified assumptions in order to determine a relative trend in these
potential impacts for a variety of oceanic and biological conditions.
This approach allows one to assess the trends without the extensive
process of modeling all the conditions that exist.'' This was a method
of relative analysis of 3 shelf cases vs. 3 biology types (yielding 9
different combinations of the factors) for each of two potential
coastal standoff cases to estimate relative impacts.
Comment 83: The Navy fails to consider all reasonable alternatives
for expanding its coastal exclusion zones.
Response: See Comment 67 and the Final SEIS (Subchapter 4.7.6 and
RTCs 4.7.12, 4.7.13, 4.7.14, nd 4.7.15.) for response.
Comment 84: The Navy has done very little to respond to the Court's
holding with respect to additional offshore exclusion areas. Five of
the seven OBIAs in the Navy's preferred alternative were already
included in the 2002 Final Rule, among those places where received
levels were capped at 180 dB, and thus are not additional mitigations
at all.
Response: NMFS has continued in these regulations a means to
propose OBIAs, from any source, including the public. NMFS will accept
petitions for OBIAs in accordance with 50 CFR 216.191. Additionally,
based on the conclusions of the Final SEIS and previous NMFS Biological
Opinions on LFA sonar (2002-2006), SURTASS LFA sonar is not likely to
affect fish or sea turtles. The analyses in the Final EIS and Final
SEIS support the conclusion that LFA sonar operations are not likely to
cause injury to marine mammals, and minimal potential to cause
significant changes in biologically important behaviors.
Under NMFS' first five year rule (50 CFR 216.191) concerning the
designation of additional OBIAs, no nominations have been received.
Comment 85: One of the central flaws of the 2001 Final EIS was its
failure to consider concentrating training with LFA sonar into
specific, low impact areas, rather than spreading it around the globe.
Response: See Comment 67.
Comment 86: The Navy rejects NMFS' 360-degree, one km buffer zone
extending out from the 180 dB isopleths.
Response: See Comment 68.
Comment 87: The Navy rejects the 330 Hz restriction imposed by
NMFS.
Response: See Comment 68.
Comment 88: The Navy fails to implement the following mitigation
measures: LFA sonar ramp-up, third-party marine biological visual
observers, acoustic monitoring using existing acoustic nodes and other
external platforms, a modification of sonar signal characteristics,
avoidance of enclosed areas and coastal areas with complex, steep sea
bed topography, lower power levels, wider safety zones, operational
procedures in coastal zones that allow escape routes, and meaningful
geographic restriction, avoidance of hot-spots.
Response: Ramp-up of the LFA sonar source is not required because
the HF/M3 sonar will be ``ramped-up'' prior to LF transmissions to
verify that the LFA sonar mitigation zone is clear of marine animals
prior to turning on the LFA sonar. Please see Final EIS RTCs 5-2.26 and
5-2.27 and NMFS 2002 Final Rule RTCs MOC19, MOC20, and MOC21 for
additional information.
As mentioned previously, utilization of third-party marine
biological visual observers is also not feasible due to berthing
concerns and security clearances. Please see Comment 81 in this
document and the NMFS 2002 Final Rule (RTC MOC32) for further
discussion. The Final EIS (Subchapter 5.2.1) states that visual
monitoring is required during daylight hours. The effectiveness of
visual monitoring declines during high sea states and periods of
reduced visibility. Because of
[[Page 46877]]
the limitations of both passive acoustic and visual monitoring, the
Navy developed the HF/M3 sonar to provide 24-hour, all-weather active
acoustic monitoring of an area of approximately 2-km (1.1-nm) radius
from the array. Moreover, to the extent that the comment is suggesting
this, NMFS has no reason to believe that the Navy is not complying with
its obligations under the regulations, and thus there is no need for
observers to confirm compliance. The reporting requirement is designed
to enable NMFS to verify that its regulations are being followed and to
assist NMFS in improving its mitigation requirements.
Monitoring mitigation is designed to preclude marine mammals from
being within the 180-dB mitigation zone of the LFA sonar array to
protect them from potential injury. This zone is approximately 1-km
(0.54 nm) in radius, thus making the use of other existing acoustic
nodes (assuming the commenter is referring to fixed arrays such as
SOSUS) and other external platforms not only impractical, but virtually
impossible. The SOSUS arrays are no longer manned nor maintained, so
their operations are degraded and not real-time. Other external
platforms would only be vessels of opportunity. Because the SURTASS LFA
sonar vessel would have limited or no communications with these vessels
and the time delay in relaying information, the use of these platforms
is impractical.
NMFS and the Navy do not consider modification of sonar signal
characteristics (including reduction in source level) to be a practical
mitigation option. First, the analyses and actual operations have
demonstrated that the present mitigation methods are effective. The LFS
SRP utilized the actual LFA sonar signal, sometimes at full power, with
only minor behavioral effects. The Fish Controlled Exposure Experiment
also utilized actual LFA sonar signals and source levels with no injury
and minimal behavioral responses at received levels up to 193 dB.
During the first four LOAs, the LFA sonar vessels completed 40 missions
with over 470 hours of actual transmission (sound-in-the-water) with no
known Level A harassment takes and Level B harassment takes estimated
well within the requirement of the LOAs. Second, wavetrain
characteristics and array source levels are optimally designed to
detect threat submarines at long distances. Return signals are below
ambient levels and any changes would potentially cause degradation in
detection effectiveness. Therefore, there is no need for the Navy to
consider modification of LFA sonar's signal characteristics, and NMFS
is satisfied that doing so would not be practicable and would result in
an ``impact on the effectiveness of the military readiness activity.''
NMFS and the Navy concur that LFA sonar operations should avoid
enclosed areas and coastal areas with complex, steep seabed topography.
First, because of the lengths of both the passive (SURTASS) and active
(LFA sonar) line arrays, enclosed areas are avoided. Second, during the
annual LOA application process (Final SEIS Subchapter 4.4 and Figure
4.4-1), marine mammal habitats, seasonal activities, and behavioral
activities are considered in the process of determining potential
mission areas. Thus these areas will be analyzed as part of the annual
LOA application process. Therefore, NMFS believes that the Navy avoids
planning and conducting LFA sonar operations in areas of known high
marine animal densities or ``hot spots.''
As noted in the Final SEIS Subchapter 2.5.2.1, SURTASS LFA sonar
operations are planned for areas with reduced risk by avoiding areas of
high marine life concentrations. This process is detailed in SEIS
Subchapter 4.4. Additionally, nominations for inclusion as OBIA can be
made under 50 CFR 216.191, thus providing protection for specific
geographic ``hot spots.''
Because SURTASS LFA sonar will have a coastal standoff distance (at
least 12 nm (22 km)), any LFA sonar signal heard by marine animals in
the coastal zone will come from the same general direction, thus
allowing an animal to move laterally away from the signal's source.
Also, NMFS has addressed the wider coastal exclusion zone in Comment
67.
Comment 89: The Navy refuses to adopt small-craft pre-operational
surveys for marine mammals in missions close to shore. The Court held
that such surveys are necessary to protect marine life. The Navy does
not consider: The option of using boats launched from shore; the fact
that any minor disturbance to marine mammals from small planes and
small boats would be far outstripped by the risk of serious injury and
death that might result if marine mammals remain undetected in the zone
of highest impact; using more than a single small boat if a single
small boat is insufficient to task; the fact that the effectiveness of
any visual monitoring program, including the one used by the Navy, is
diminished by high sea states, low visibility and diving habits of
whales, making additional mitigation more important; and the
comparative cost of operating LFA sonar in a manner that exposes
coastal marine mammals to a higher risk of stranding and other
injuries.
Response: As previously mentioned, the Stipulation Regarding the
Permanent Injunction issued on 14 October 2003 by the U.S. District
Court, Northern District of California, as amended by Order dated July
7, 2005, and as agreed to by the parties, stated that the Navy is not
required to conduct ``pre-operation surveys'' as described in the
Opinion and Order. In response to the Opinion and Order, the Navy
provided an evaluation of the use of small boats and aircraft for pre-
operational surveys in the DSEIS Subchapter 5.4. That evaluation
demonstrated that small boat and pre-operational aerial surveys for
SURTASS LFA sonar operations are not feasible because they are not
practicable, not effective, may increase the harassment of marine
mammals, and are not safe to the observers. As a result, under this
directive and in compliance with the amendments to the MMPA as made by
the NDAA FY04, pre-operational surveys are not considered as a viable
mitigation measure.
Vessels launched from land were addressed in the Final SEIS. They
would have to sail from ports within reasonable distance from the
operations site. Because of the classified nature of LFA sonar
operations, National Security considerations would preclude the ability
to arrange these vessels in advance. However, the primary concern with
the utilization of small boats is not their effectiveness, but their
unsafe nature and the impracticality of their operations from the LFA
sonar vessels. Therefore, if the use of a single survey boat is
considered impractical and unsafe, then this would concomitantly apply
to the utilization of additional boats.
The Final SEIS did not state that the visual observers onboard the
LFA sonar vessels would be able to see marine mammals better than
visual observers during aerial surveys, nor were helicopters mentioned.
Subchapter 4.2.7.1 of the Final EIS states that visual monitoring is
limited to daylight hours and its effectiveness declines during high
sea states. Because of the limitations of both passive acoustic and
visual monitoring, the Navy developed the HF/M3 sonar to provide 24-
hour, all-weather active acoustic monitoring of an area of
approximately 2-km (1.1 nm) radius from the array. In calculating the
effectiveness for the various monitoring systems for purposes of the
Final EIS, the visual monitoring component of the three-part monitoring
[[Page 46878]]
system was estimated at 0.09, or 9 percent and the passive monitoring
component was 0.25 or 25 percent effective. Utilization of the HF/M3
sonar with an effectiveness value of 0.95 or 95 percent raises the
overall mitigation effectiveness to 0.98 or 98 percent (DON, 2007)
When operated under the mitigation protocols required under this
rulemaking, NMFS believes that marine mammals will not be exposed to
LFA sonar sound levels that will cause injuries or strandings
regardless of whether they are in coastal or open ocean waters. As
mentioned previously, LFA sonar has never caused, nor is expected to
cause, marine mammal strandings.
Comment 90: The AEI suggests a lower allowable threshold for
received levels at 22 km from shore, to protect these biologically
important areas for received levels at 22 km in response to moderate
noise levels. Given the relatively long duration of SURTASS LFA sonar
``pings,'' masking may be more of an issue that it is with impulsive
noise sources.
Response: The subject of masking has been addressed in response to
several comments in this rule. The Final SEIS states that mitigation
measures for SURTASS LFA sonar operations would be conducted such that
the sound field is below 180 dB received level (RL) within 12 nm (22
km) of any coastline, including islands. RLs below 180 dB for LFA sonar
will not result in serious injury or death. The Final EIS provided
detailed analyses of the potential effects of exposure to LFA sonar
received levels less than 180 dB for 31 separate sites. These included
numerous sites that were at the closest proximity to land based on
SURTASS LFA sonar operational limits where biological densities were
high. These analyses determined that potential effects from exposures
to LFA sonar RLs greater than or equal to 180 dB were negligible and
less than 180 dB were minimal. However, during the annual LOA
application process for operations close to coastal areas (and OBIAs),
the potential for marine mammal stocks to be affected at RLs less than
180 dB are determined, as outlined in the risk assessment approach
described in the Final SEIS Subchapter 4.4. As shown in Tables 4.4-2 to
4.4-10 in the Final SEIS, minimal percentages of marine mammal stocks
will be affected, which includes the potential to disturb a marine
mammal by causing disruption of natural behavioral patterns to a point
where the patterns are abandoned or significantly altered.
Comment 91: Why is the continental shelf off the east coast of
North America the only shelf area given a broad exclusion? If there are
biologically important reasons to keep the SURTASS LFA sonar signal out
of this area, then it follows that other parts of the world's coastal
margins at depths of less than 200 m (656 ft) should also be protected.
Response: The intention of the 12 nm (22 km) coastal restriction is
to provide protection to areas of greater concentrations of marine
mammals and their migration routes. The 12 nm (22-km) exclusion zone is
not tied to the width of the continental shelf because of the large
variability of the shelf's distance from coastlines around the world.
For example, on the U.S. eastern seaboard this distance is 60 to 70 nm
(111 to 130 km) from the coast while in Hawaii it can be 5 nm (9.3 km)
or less. In order to provide protection to biologically important areas
outside of 12 nm, several OBIAs have been designated, including one new
one with this Final Rule. Because of animal concentrations and
migration routes on the eastern seaboard over the continental shelf,
this area has been designated as an OBIA in the Final Rule with limits
extending to the 200 m (660 ft) isobath for the East Coast of the
United States (from 28 N to 50 N west of 40 W) to protect more species.
The 12-nm (22-km) restriction includes almost all marine related
critical habitats and NMSs. However, some parts of NMSs, that are
recognized to be important for marine mammals, are outside 12 nm (22
km). As a result, NMSs have been designated as OBIAs as shown in SEIS
Table 2 3 and this Final Rule, and the 12-nm coastal exclusion zone has
been increased to include the LFA sonar ``buffer zone'' of 1 km (0.54
nm). This additional mitigation ensures that LFA sonar SPLs are below
174 dB within OBIAs.
Comment 92: With the lone exception of The Gully, no new OBIA
outside U.S. waters is even considered by NMFS. For example, the Navy's
analysis does not consider any of the areas specifically mentioned in
the Court's Opinion as potential OBIAs, such as the southern end of the
Oyashio/Kuroshio region off Kamchatka and the area where the Emperor
Seamount Chain intersects the Aleutian Rise.
Response: Areas mentioned by the Court's Opinion and Order of
August 26, 2003, are Oyashio/Kuroshio area off Kamchatka, and the
Emperor Seamount Chain (45 to 55 deg N latitude and 170 to 160 deg W
longitude (the Court's Opinion erroneously listed this longitude as 60
degrees. The northern part of the Oyashio/Kuroshio area off Kamchatka
is within the Bering Sea, which is a non-operational area as presented
in the Final EIS, Figure 1-1. The southern portion of this area and the
Emperor Seamount Chain are large ocean expanses. As stated in NMFS'
2002 Final Rule (RTC MIC11), marine mammals in unspecified migration
corridors and open ocean concentrations should be adequately protected
by the tripartite monitoring and mitigation protocols. Please see
comment 93 for further information on OBIAs.
Comment 93: The commenter states that he has worked on Marine
Protected Areas (MPAs) worldwide, focusing on marine mammals, and his
book ``Marine Protected Areas for Whales, Dolphins & Porpoises'' (2005)
details more than 350 existing MPAs for cetaceans and a further 175
areas proposed for protection. There are also 20 countries and
territories that have declared their 200 nm EEZs as marine mammal
protection zones. If 70 percent of the world ocean is now to be opened
to LF sonar ensonification, it is possible that marine mammals in this
proposed and existing MPAs will be impacted.
Response: First, NMFS notes that while 70-75 percent of the world
ocean will be open to LF sonar operations, that does not equate to LFA
sonar operations affecting even close to 70-75 percent of the world's
ocean area at any given time. In addition, because most MPAs are mostly
located in coastal waters, where LFA sonar will not operate, MPAs are
unlikely to receive high SPLs from SURTASS LFA sonar.
NMFS and the Navy did consider adopting MPAs as OBIAs, as shown in
the Final SEIS. MPAs are discussed under E.O. 13158 in Chapter 6 and
are further discussed in Comment 4.7.19 in Chapter 10. The commenter's
book, Hoyt (2005), was also cited in the Final SEIS. Hoyt (2005) states
that most MPAs fall within the nation's EEZ limits and most of them are
coastal and would therefore fall within the SURTASS LFA sonar coastal
exclusion zone. OBIAs are not designated based on speculation on the
location and density of animals. As with the first Final Rule, NMFS has
in place a process for the public to propose OBIAs. An area must be of
particular importance for marine mammals as an area for primary
feeding, breeding, or migration, and not simply an area occupied by
marine mammals. The proposed area should also not be within a
previously designated OBIA or other 180-dB exclusion area. Further
information on proposing OBIAs can be found in the Designation of
Biologically Important Marine Mammal Areas section of this Final Rule.
[[Page 46879]]
Comment 94: NMFS does not consider any MPAs established by
countries other than the U.S., such as any of Canada's 9 existing MPAs
with cetaceans (with the exception of The Gully), Australia's 38
existing MPAs with cetaceans, or Brazil's 16 existing MPAs with
cetaceans--or any of the non-U.S. protected areas discussed in the
recent, relevant assessment (i.e., Hoyt, 2005).
Response: We have reviewed previously the areas cited by the
commenter and note that they are within the coastal exclusion zone of
these nations, as mentioned by Hoyt (2005). NMFS believes that the
level of information about marine mammal abundance is lacking for many
parts of the world. However, based on its review of the available
science, NMFS believes that it has designated all OBIAs that are
currently appropriate for designation.
Comment 95: The Navy does not consider any of the biologically
significant, globally representative areas compiled in the 1990s by the
World Conservation Union (IUCN), in conjunction with the World Bank and
the Great Barrier Reef Marine Park Authority: A recent published
assessment of beaked whale hotspots, which identifies more than 20
areas of significant global concern based on currently available
evidence.
Response: NMFS does not believe that areas that are vaguely
described as areas of marine mammal habitation, such as beaked whale
``hotspots,'' meet the requirement for designation as OBIAs. Also, NMFS
does not currently have sufficient information on these areas to know
if they meet the criteria for an OBIA. In order for NMFS to make a
preliminary determination that an area is biologically important for
marine mammals, it needs detailed information on the biology of marine
mammals within the area, including estimated population size,
distribution, density, status, and the principal biological activity
during the proposed period of designation sufficient for; and detailed
information on the area with regard to its importance for feeding,
breeding, or migration for those species of marine mammals that have
the potential to be affected by low frequency sounds. Areas within 12
nm (22 km) of any coastline, including offshore islands (which includes
most MPAs), or within non-operating areas for SURTASS LFA sonar (Arctic
Ocean) are not eligible for consideration. In its comment, the
commenter lists other literary sources that give information for
designation as OBIAs. However, these, documents do not provide
information sufficient for NMFS to begin the designation process
outlined in the regulations.
Comment 96: U.S. MPAs are noted in this proposed rulemaking, but
MPAs in other countries are not. For example, what about the important
marine mammal sanctuary in waters of the Dominican Republic? Or the
international Indian Ocean whale sanctuary designated by the IWC? What
about MPAs in the south China sea, on the Russian coast, or in the
Philippine Sea, some of which are specifically for threatened
cetaceans?
Response: NMFS does not consider it necessary to expand the list of
OBIAs prior to its making the required determinations under section
101(a)(5)(A) of the MMPA. NMFS established a process for nominating new
OBIAs in its 2002 rulemaking. During the past 5 years, NMFS has not
received any nominations from the public for new OBIAs. It should be
recognized that while NMFS may nominate areas as OBIAs, it does not
believe that it should be the sole proponent for nominating areas and
that was the reason for allowing it to be a public process following
standard rulemaking practice. NMFS recommends however, that areas
already subject to significant anthropogenic noise such as seismic and
shipping areas within 12 nm (22 km) of any coastline, or otherwise
already excluded (Arctic, Antarctic oceans), areas that cannot be
geographically described, and areas designated for non-biological
reasons (e.g., the IWC's Indian Ocean Sanctuary) not be nominated.
Areas being nominated must include sufficient information to indicate
why that area warrants more protection than would be provided through
the Navy's visual, passive acoustic and HF/M3 monitoring program and
180-dB shut-down procedures.
Comment 97: NMFS has not considered establishing larger buffer
zones around even the few exclusion zones it has identified, allowing
ensonification in these areas up to 180 dB even though significant
impacts on marine mammal behavior are expected well below this level
and would rise, according to the Navy's risk function, as pressure
levels increase. Allowing the Navy to place the LFA sonar system
directly outside the Monterey Bay National Marine Sanctuary (for
example) does not, by any argument, reduce impacts to marine mammals in
the Sanctuary to the maximum extent practicable.
Response: As a result of the comment, NMFS has reviewed the
information it currently has and has determined that by requiring the
Navy to maintain approximately 2-km (1.1-nm) stand-off distance from
the outer boundary of any OBIA, SPLs within the NMS will be reduced to
approximately 174 dB. This means that the LFA sonar vessel must observe
both the measured 180-dB zone and the additional 1-km (0.54 nm) buffer
zone from the outer edge of all OBIAs. This measure is both practicable
for the Navy to implement, will not cause significant impact to the
Navy for conducting LFA sonar operations and results in reducing sounds
within NMSs to the lowest level practicable.
Comment 98: The Navy will operate LFA sonar without any limitations
or mitigation during periods of ``armed conflict or direct combat
support operations, (or) during periods of heightened threat
conditions.''
Response: Depending upon the situation, the Navy may decide to
implement mitigation measures to protect marine mammals. However, that
issue is beyond the current rulemaking action. Depending upon the area
and duration of activity, NMFS may determine appropriate review
necessary prior to issuing new LOAs after cessation of the armed combat
situation.
Comment 99: NMFS has reviewed the Annual Reports without requiring
any more mitigation measures.
Response: Based on its review of the Annual Reports, NMFS did not
believe that additional mitigation was either practicable or warranted.
However, as part of its review of the Navy's SURTASS LFA sonar
application, and the comments submitted by the public as part of its
rulemaking process, NMFS has added The Gully as an OBIA and has added a
new mitigation measure to limit sounds entering offshore OBIAs. An
analysis of mitigation and monitoring measures has been provided
previously in this document.
Monitoring Concerns
Comment 100: The Navy's monitoring over the past five years has
been inadequate to gauge the impact the system is having on marine
mammals and other species in the western Pacific.
Response: The 180-dB and 1-km mitigation zone was monitored at all
times during LFA sonar active transmissions, as required by NMFS 2002
Final Rule (50 CFR 216.185 and 50 CFR 216.186) and LOAs. In addition,
as mentioned previously in this document, available stranding data from
the operating areas are continuously reviewed, and no strandings are
known to have coincided spatially or temporally with LFA sonar
operations. Further, an evaluation of the effectiveness of the
monitoring and
[[Page 46880]]
mitigation measures has been provided to NMFS in the final
Comprehensive Report (DON, 2007a) submitted under 50 CFR 216.186(c).
Monitoring areas beyond the buffer zone are not practical from the LFA
sonar vessel. As a result, NMFS has required the Navy to conduct
research in order to monitor potential impacts at some distance from
the vessel. For more information on research, please see the Research
section of this document.
Comment 101: NMFS should consider prescribing the following
monitoring methods: suspension of acoustic exercises outside daylight
hours and during periods of low visibility; aerial surveillance for
marine mammals; passive acoustic monitoring using the Navy's existing
acoustic nodes in certain ranges and operating areas and various other
external platforms, and third-party monitoring by marine biologists.
Response: Operations do not need to be suspended during times of
reduced visibility, including darkness, because the Navy's HF/M3 sonar
is equally effective during these periods at detecting any marine
mammals within the area where injury may occur.
Aerial surveillance has been discussed previously in this document
(see Final SEIS RTCs EIIs-4, 10, 11). Pre-operational aerial surveys
are not practicable mitigation.
Passive monitoring and second vessel monitoring has been addressed
in comment 88 and elsewhere. Because the nodes are inoperable and the
SURTASS LFA sonar vessel would have limited or no communications with
these vessels and the time delay in relaying information, the use of
these measures are considered impracticable.
As mentioned previously, utilization of third-party marine
biological visual observers is not necessary because visual monitoring
is not the primary means of detecting marine mammals and NMFS has no
reason to believe that the Navy is not complying with the regulatory
requirements, and it is not feasible due to berthing concerns and
security clearances. Please see Comments 81 and 88 in this document and
the NMFS 2002 Final Rule (RTC MOC32) for further discussion.
Comment 102: NMFS must question why no verification results are
available. Why has there been no embedded but independent research
concurrent with those Pacific LFA sonar operations?
Response: The SURTASS LFA sonar vessels are military vessels
conducting training exercises; they are not research vessels capable of
carrying independent research scientists. Also, because these are
military vessels, researchers would be required to have a security
clearance prior to conducting any research onboard them. As a result,
NMFS and the Navy determined that an LTM program provided the best
opportunity to verify (or refute) the current findings that impacts
will be negligible. The LTM discussion in the Final EIS (and
incorporated by reference in the Final SEIS) has been continued under
the new regulations. Under NMFS regulations, the Navy is required to
conduct an LTM (as discussed in detail elsewhere (see Research
Concerns)) . The status of this research was summarized in Table 2-5 of
the Draft and Final SEIS. Planning has commenced for a 2007-2008 deep-
diving odontocetes BRS to determine the potential effects of LFA sonar,
MFA, and seismic sources on beaked whales and other deep diving
odontocetes. Further LTM research will bedetermined by the decision-
maker in the Navy's ROD and in consultation with NMFS.
Reporting Concerns
Comment 103: Acoustical detections from the continuously operating
HF/M3 sonar systems only logged 16 ``events'' in 10 of 16 missions.
Visual monitoring logged cetaceans within the buffer zone only on three
occasions during all LFA sonar operations. No marine turtles were ever
seen. LFA sonar transmissions were delayed or suspended on 33
occasions, many because of system failures or unverified detections,
and only one resulted from a sighting of dolphins. Does NMFS accept
that the very few sightings in the Annual Reports mean that very few
animals were actually present?
Response: The Navy's Final Comprehensive Report indicates that,
under the first four LOAs totaling 40 missions, there were 3 visual
sightings of marine mammals, no passive acoustic detections, and 71
active acoustic detections. Based on the quarterly, annual, and Final
Comprehensive reports, and based on the fact that the Navy avoids areas
of high marine life concentrations, NMFS believes the Navy's reports
that there have been few marine mammal sightings as an indicator that
either few marine mammals are present (low density) or marine mammals
are avoiding the immediate area of LFA sonar operations prior to
commencing LFA sonar operations.
Research Concerns
Comment 104: In 2003, the Navy was provided a limited area within
which to deploy SURTASS LFA sonar. While it has been required to report
on mitigation measures taken to prevent or minimize marine mammal takes
in the immediate operating area, it has not been required to perform
systematic population studies on marine mammals or examinations of
stranding incidents and health trends in operating range. Given both
the extent of the current range, as well as the far reach of the
SURTASS LFA sonar signals, the health of animals ``taken'' in this area
alone would be difficult to assess. Given the short period that the
U.S. Navy has been operating in a limited deployment area it is
difficult to determine any trends in the natural history, biology and
behavior of marine mammals subjected to the SURTASS LFA sonar noise.
Response: NMFS' LOAs under Condition 7(d) require the Navy to
conduct research in accordance with 50 CFR 216.185(e). The Navy's
completed and ongoing research is detailed in the Final Comprehensive
Report (DON, 2007a) and in the Final SEIS Subchapter 2.7. See the Final
SEIS RTC 5.3.2 for additional information. Baseline data on the
distribution and behavior of marine animals are discussed in the Final
SEIS RTCs 1.4.1 and 2.7.2. Prioritization of the available research
monies by the Navy does not at this time allow for the systematic
population studies on marine mammals. Based on recommendations from the
scientific community, planning is underway for a 2007-2008 deep-diving
odontocetes BRS to determine the potential effects of LFA sonar, MFA,
and seismic sources on beaked whales and other deep diving odontocetes.
Reviews of stranding reports in the area showed that there were a
total of 19 strandings reported in Asia (four in Taiwan, nine
throughout the Philippines, two in Thailand, two in Indonesia, and two
in China) (The Cetacean Stranding Database, accessed: 11/28/2006). None
of these strandings were coincident either temporally or spatially with
LFA sonar operations. See the Final SEIS (RTC 4.4.12) for additional
information of strandings.
Comment 105: What has resulted from research projects related to
LFA sonar?
Response: Under the NMFS 2002 and 2007 rulemaking and related LOAs
for LFA sonar, the Navy is required to conduct research. These topics
and their status are provided in the Final Comprehensive Report (DON,
2007). The Navy is working to meet these research requirements. The
SURTASS LFA sonar LTM Program has been budgeted by the Navy at a level
of approximately $1M per year for five years, starting with the
issuance of the first LOA in 2002. Planningis underway for a 2007-2008
deep-diving odontocetes BRS to determine the potential effects of LFA
sonar, MFA,
[[Page 46881]]
and seismic sources on beaked whales and other deep diving odontocetes
at an estimated cost of $3M per year.
Although not directly related to the LFA sonar MMPA regulatory
process, the Navy funded independent research to determine the
potential for SURTASS LFA sonar signals to affect fish. Popper et al.
(2007) investigated the effects of exposure to LFA sonar on rainbow
trout (a hearing generalist related to several endangered salmonids)
and channel catfish (a hearing specialist) using an element of the
standard SURTASS LFA sonar source array (Popper et al., 2005; Halvorsen
et al., 2006; Popper et al., 2007).
Comment 106: Why is no current effort to quantify and monitor long-
term, cumulative, stock-level impacts from LFA sonar mentioned in the
LFA sonar 2005 Annual Report?
Response: NMFS recommended this as a research topic. However,
detecting and scientifically validating a change in a marine mammal
population (e.g., trend, demographics) is extremely difficult. It is
also unrealistic to expect a single factor to explain population
changes. For LFA sonar, research results indicate that some whales will
respond to LFA sonar over relatively short temporal periods and over
small spatial areas, though this research was only capable of testing
for responses over short time periods and spatial scales. To date,
there is no evidence that LFA sonar will have an effect on individual
survival or reproductive success, or population trends or demographics.
However, because research on the appropriate temporal and spatial
scales has not been conducted, questions concerning the level of impact
at such scales remain.
Comment 107: A prioritized study of beaked whale habitats is only
at the draft planning stage, although considerable work has been done
previously to identify likely habitats in certain regions such as the
Mediterranean. While this work also may help to identify the critical
link between sonars and beaked whale deaths, the primary goal may
simply be to identify areas where naval sonars should not operate for
test and training.
Response: Research on beaked whales is underway. A list of recently
published papers that was the result of funding by ONR and SERDP was
provided in Comment 39. Again, it is worth noting that beaked whales
appear to be a species sensitive, under certain conditions, to MF
sonar, not LFA sonar.
Comment 108: Behavioral reactions of whales to sound levels above
155 dB have not been tested, in part because the Navy has assumed the
required authorization would be extremely hard to get, but primarily
because expert researchers have been concerned that such received sound
levels might have harmed the research subjects. NMFS should review the
size of the potential LFA sonar impact zone based upon the 155 dB
isopleth.
Response: Estimates of Level B harassment take are calculated using
the risk continum from 120 dB to 179 dB, and NMFS considers all marine
mammals to be injured at an SPL of 180 dB or greater, considers, even
though at 180 dB, marine mammals are unlikely to even incur TTS (Level
B harassment). Therefore, NMFS believes reviewing the size of the LFA
sonar impact zone based upon the 155 dB isopleth is unnecessary.
Originally, there was concern that if marine mammals experience a
significant change in a biologically important behavior at moderate-to-
low sound exposure levels, then such exposures could potentially have
an impact on rates of reproduction or survival. Knowing that cetacean
responses to LF sound signals needed to be better defined using
controlled experiments, the Navy helped develop and supported the
three-year LFS SRP beginning in 1997. This study was designed to assess
the potential impacts of SURTASS LFA sonar on the behavior of low-
frequency hearing specialists, those species believed to be at
(potentially) greatest risk. This field research program was designed
to address three important behavioral contexts for baleen whales: (1)
Blue and fin whales feeding in the southern California Bight, (2) gray
whales migrating past the central California coast, and (3) humpback
whales breeding off Hawaii. Taken together, the results from the three
phases of the LFS SRP do not support the hypothesis that most baleen
whales exposed to RLs near 140 dB would exhibit disturbance behavior
and avoid the area. These experiments, which exposed baleen whales to
RLs ranging from 120 to about 155 dB, detected only minor, short-term
behavioral responses. Short-term behavioral responses do not
necessarily constitute significant changes in biologically important
behaviors.
These results have been supported by recent, peer reviewed papers.
Croll et al. (2001a), Miller et al. (2000) and Fristrup et al. (2003)
that were discussed previously in this document.
Comment 109: There has been classified research to determine if
large whales are silenced by anthropogenic noise, presumably sonars,
but it has occurred in the Atlantic and its applicability to LFA sonar
operations is unknown to the public. Has NMFS reviewed this data?
Response: As reported in the Final Comprehensive Report, passive
acoustic monitoring for the possible silencing of calls of large whales
using bottom-mounted hydrophones is ongoing. Four research efforts in
the North Atlantic (NORLANT, 2004, 2005, 2006-01, 2006-02) have
addressed this topic. The research reports for these tasks are
classified; unclassified summary reports have been produced. Navy
funding has supported and continues to support these research efforts.
NMFS has not reviewed any data from this classified research.
Comment 110: CSI recommends research with an immediate focus on
cetacean fear, aversion, or avoidance responses to sonars.
Response: Under the application for the BRS for Deep Diving
Odontocetes, the Navy (and its partners) proposes to examine behavioral
responses to anthropogenic sounds. The proposed BRS study has not yet
received a scientific research permit (SRP) under section 104 of the
MMPA. If an SRP is issued under section 104 of the MMPA, the proposed
BRS would first investigate the acoustic exposures of MF sonar, not LF
sonar, and natural sounds. If the BRS is successful and if NMFS is able
to issue a second SRP, the BRS proposes to then determine the acoustic
exposures of LF sonar. The rationale for this is that beaked whales are
not known to have good hearing in the LF range, and as such LFA sonar
has not been implicated in any stranding events. Additional information
on this study can be found at 72 FR 19181 (April 17, 2007).
Comment 111: The Navy's BRS research (72 FR 19181, April 17, 2007)
should be completed before the U.S. Navy is given a 5-year permit to
operate the LFA sonar system. Given the controversy on the potential
impacts of the low frequency transmissions in sound ducts on marine
mammals beyond the buffer zone, it seems inconsistent with the
precautionary approach to give the Navy a permit until this research
has been completed. This research should be completed by an independent
third party and not by the Navy/NMFS.
Response: NMFS believes that it has sufficient scientific
information to make the determinations required by section 101(a)(5)(A)
of the MMPA. In addition, the Navy has advised that a gap in SURTASS
LFA sonar operations would be detrimental to national security and
reduce protection of U.S. and Allied naval forces from submarine
threats. Uninterrupted operational deployment
[[Page 46882]]
of SURTASS LFA sonar is the Pacific Fleet Commander's top antisubmarine
warfare priority. As NMFS believes the Navy has adopted a precautionary
approach using conservative assumptions for identifying and analyzing
potential impacts to the environment, including marine mammals, it has
determined that it is not necessary to withhold the MMPA authorization
to the Navy. Lastly, the Navy and NMFS are working with many
independent researchers (third party scientists) to complete the BRS.
Therefore, the Final Rule does not need to be delayed for the
completion of the proposed BRS.
NEPA Concerns
Comment 112: With the Supplemental EIS, the Navy hopes not only to
correct the deficiencies identified by the Court in the 2001 Final EIS,
but also to fulfill its NEPA requirement for an analysis of the
environmental impacts of its second five years of LFA sonar operation
from 2007 through 2012. The Navy's application for a new incidental
take authorization, however, is a separate final agency action from its
original application, and, absent the sort of tiering that has not been
conducted here, requires its own EIS.
Response: The Navy prepared an original Final EIS for SURTASS LFA
sonar in January, 2001. In accordance with CEQ regulations (40 CFR
1502.9), agencies are required to prepare a Supplemental EIS (SEIS)
when the agency makes substantial changes to the proposed action that
are relevant to environmental concerns, there are significant new
circumstances or information relevant to environmental concerns and
bearing on the proposed action and its impacts, or if the agency
determines that the purposes of the act will be furthered. The Navy
prepared this SEIS to both address the District Court findings and to
review new information relevant to impacts on the marine environment
from SURTASS LFA sonar operations. As NMFS is a cooperating agency, as
defined under NEPA regulations, in the preparation of the Draft SEIS
and the Final SEIS, the issuance of this rulemaking, based upon an
application for an incidental take authorization under the MMPA is not
considered an action separate from the SURTASS LFA sonar operation.
In accordance with 40 CFR 1506.3(a), NOAA has adopted the Navy's
Final SEIS as its own NEPA statement on the issuance of regulations and
LOAs for the taking of marine mammals incidental to SURTASS LFA sonar
operations.
Comment 113: What rationale does the Navy now assert for failing to
prepare an EIS for use of SURTASS LFA sonar during threat and warfare
conditions?
Response: As stated in NMFS' 2002 final rule Federal Register
notice, (RTC AC2), war, combat, and heightened threat conditions are
determined by the Congress or the National Command Authorities (NCA),
not the U.S. Navy. Chapter 1 (Purpose and Need) and RTC 1-1.7 of the
Final EIS identify the NCA as the President and the Secretary of
Defense (or their duly designated alternates or successors), as
assisted by the Chairman of the Joint Chiefs of Staff. Since these
determinations are not made by the Navy, both the application and the
Navy's Draft and Final EISs and SEISs are specifically limited to
employment of the SURTASS LFA sonar during training, testing, and
routine military operations and will not cover use of the SURTASS LFA
sonar system in self-defense, in times of war, combat, or heightened
threat conditions.
Affected Marine Mammal Species
In its Final SEIS and Final EIS and application, the Navy excluded
from incidental take consideration marine mammal species that do not
inhabit the areas in which SURTASS LFA sonar would operate. Where data
were not available or were insufficient for one species, comparable
data for a related species were used. Because all species of baleen
whales produce LF sounds, and anatomical evidence strongly suggests
their inner ears are well adapted for LF hearing, all balaenopterid
species are considered sensitive to LF sound and, therefore, at risk of
harassment or injury from exposure to LF sounds. The twelve species of
baleen whales that may be affected by SURTASS LFA sonar are blue, fin,
minke, Bryde's, sei, humpback, North Atlantic right, North Pacific
right, southern right, pygmy right, bowhead, and gray whales.
The odontocetes (toothed whales) that may be affected because they
inhabit the deeper, offshore waters where SURTASS LFA sonar might
operate include both the pelagic (oceanic) whales and dolphins and
those coastal species that also occur in deep water including harbor
porpoise, spectacled porpoise, beluga, Stenella spp., Risso's dolphin,
rough-toothed dolphin, Fraser's dolphin, northern right-whale dolphin,
southern right-whale dolphin, short-beaked common dolphin, long-beaked
common dolphin, very long-beaked common dolphin, Lagenorhynchus spp.,
Cephalorhynchus spp., bottlenose dolphin, Dall's porpoise, melon-headed
whale, beaked whales (Berardius spp., Hyperoodon spp., Mesoplodon spp.,
Cuvier's beaked whale, Shepard's beaked whale, Longman's beaked whale),
killer whale, false killer whale, pygmy killer whale, sperm whale,
dwarf and pygmy sperm whales, and short-finned and long-finned pilot
whales.
Potentially affected pinnipeds include hooded seal, harbor seal,
spotted seal, ribbon seal, gray seal, elephant seal, Hawaiian monk
seal, Mediterranean monk seal, northern fur seal, southern fur seal
(Arctocephalus spp.), harp seal, Galapagos sea lion, Japanese sea lion,
Steller sea lion, California sea lion, Australian sea lion, New Zealand
sea lion, and South American sea lion.
A description of affected marine mammal species, their biology, and
the criteria used to determine those species that have the potential
for being taken by incidental harassment are provided and explained in
detail in the Navy application and Final SEIS and, although not
repeated here, are considered part of the NMFS' administrative record
for this action. Additional information is available at the following
URL: http://www.nmfs.noaa.gov/pr/sars/. Please refer to these documents
for specific information on marine mammal species.
Effects on Marine Mammals
To understand the effects of LF noise on marine mammals, one must
understand the fundamentals of underwater sound and how the SURTASS LFA
sonar operates in the marine environment. This description was provided
earlier in this document and also by the Navy in Appendix B to the
Final EIS.
The effects of underwater noise on marine mammals are highly
variable, and have been categorized by Richardson et al. (1995) as
follows: (1) The noise may be too weak to be heard at the location of
the animal (i.e. lower than the prevailing ambient noise level, the
hearing threshold of the animal at relevant frequencies, or both); (2)
the noise may be audible but not strong enough to elicit any overt
behavioral response; (3) the noise may elicit behavioral reactions of
variable conspicuousness and variable relevance to the well-being of
the animal; these can range from subtle effects on respiration or other
behaviors (detectable only by statistical analysis) to active avoidance
reactions; (4) upon repeated exposure, animals may exhibit diminishing
responsiveness (called habituation), or disturbance effects may persist
(most likely with sounds that are highly variable in characteristics,
unpredictable in occurrence, and associated with situations that the
[[Page 46883]]
animal perceives as a threat); (5) any human-made noise that is strong
enough to be heard has the potential to reduce (mask) the ability of
marine mammals to hear natural sounds at similar frequencies, including
calls from conspecifics, echolocation sounds of odontocetes, and
environmental sounds such as surf noise; and (6) very strong sounds
have the potential to cause temporary or permanent reduction in hearing
sensitivity, also known as threshold shift. In terrestrial mammals, and
presumably marine mammals, received sound levels must far exceed the
animal's hearing threshold for there to be any temporary threshold
shift (TTS) in its hearing ability. For transient sounds, the sound
level necessary to cause TTS is inversely related to the duration of
the sound. As described later in this document, received sound levels
must be even higher for there to be risk of permanent hearing
impairment, or permanent threshold shift (PTS). Finally, intense
acoustic or explosive events (not relevant for this activity) may cause
trauma to tissues associated with organs vital for hearing, sound
production, respiration and other functions. This trauma may include
minor to severe hemorrhage. Severe hemorrhage could lead to death.
The original analysis of potential impacts on marine mammals from
SURTASS LFA sonar was developed by the Navy based on the results of a
literature review; the Navy's Low Frequency Sound Scientific Research
Program (LFS SRP) (described later in this document); and a complex,
comprehensive program of underwater acoustical modeling.
To assess the potential impacts on marine mammals by the SURTASS
LFA sonar source operating at a given site, it was necessary for the
Navy to predict the sound field that a given marine mammal species
could be exposed to over time. This is a multi-part process involving
(1) the ability to measure or estimate an animal's location in space
and time, (2) the ability to measure or estimate the three-dimensional
sound field at these times and locations, (3) the integration of these
two data sets into the Acoustic Integration Model (AIM) to estimate the
total acoustic exposure for each animal in the modeled population, (4)
beginning the post-AIM analysis, converting the resultant cumulative
exposures for a modeled population into an estimate of the risk from a
significant disturbance of a biologically important behavior, and (5)
using a risk continuum to convert these estimates of behavioral risk
into an assessment of risk in terms of the level of potential
biological removal.
In the post-AIM analysis, as mentioned in numbers (4) and (5)
above, a relationship was developed for converting the resultant
cumulative exposures for a modeled population into an estimate of the
risk to the entire population of a significant disruption of a
biologically important behavior and of injury. This process assessed
risk in relation to received level (RL) and repeated exposure. The
resultant risk continuum is based on the assumption that the threshold
of risk is variable and occurs over a range of conditions rather than
at a single threshold. Taken together, the LFS SRP results, the
acoustic propagation modeling, and the risk assessment provide an
estimate of potential environmental impacts to marine mammals. The
results of 4 years of monitoring (2002-2006) onboard the two SURTASS
LFA sonar vessels support the use of this methodology.
The acoustic propagation modeling was accomplished using the Navy's
standard acoustical performance prediction transmission loss model-
Parabolic Equation (PE) version 3.4. The results of this model are the
primary input to the AIM. AIM was used to estimate marine mammal sound
exposures. It integrates simulated movements (including dive patterns)
of marine mammals, a schedule of SURTASS LFA sonar transmissions, and
the predicted sound field for each transmission to estimate acoustic
exposure during a hypothetical SURTASS LFA sonar operation. Description
of the PE and AIM models, including AIM input parameters for animal
movement, diving behavior, and marine mammal distribution, abundance,
and density, are described in detail in the original Navy application
and the Final EIS (see box, page 4.2-11) and are not discussed further
in this document.
The same analytical methodology utilized in the application for the
first 5-year rule and LOAs was utilized to provide reasonable and
realistic estimates of the potential effects to marine mammals specific
to the potential mission areas as presented in the application.
Information on how the density and stock/abundance estimates are
derived for the selected mission sites is in the Navy's application.
These data are derived from current, published source documentation,
and provide general area information for each mission area with
species-specific information on the animals that could occur in that
area, including estimates for their stock abundance and density.
Although this rule uses the same analysis that was used for the
2002-2007 rule, the AIM analysis is continuously updated with new
marine mammal biological data (behavior, distribution, abundance and
density) whenever new information becomes available. It was recently
independently reviewed by a panel of experts in mathematics, modeling,
acoustics, and marine mammalogy convened by NMFS' Center for
Independent Experts (CIE). The task of the Panel was to evaluate
whether AIM correctly implements the models and data on which it is
based; whether animal movements are correctly implemented; and whether
AIM meets the Council for Regulatory Environmental Monitoring (CREM)
guidelines. As stated in their Report on AIM, the CIE Panel agreed
that: (1) AIM appears to be correctly implemented; (2) the animal
movement appears to be appropriately modeled; and (3) the principles of
credible science had been addressed during the development of AIM and
that AIM is a useful and credible tool for developing application
models. A copy of the CIE report is available (see ADDRESSES).
During the analytical process in the Final EIS, the Navy developed
31 acoustic modeling scenarios for the major ocean regions. Locations
were selected by the Navy to represent the greatest potential effects
for each of the three major ocean acoustic regimes where SURTASS LFA
sonar could potentially be used. These acoustic regimes were: (1) Deep-
water convergence zone propagation, (2) near surface duct propagation,
and (3) shallow water bottom interaction propagation. These sites were
selected to model the greatest potential for effects from the use of
SURTASS LFA sonar incorporating the following factors: (1) Closest
plausible proximity to land (from SURTASS LFA sonar operations
standpoint), and/or offshore biologically important areas (OBIAs) where
biological densities are higher, particularly for animals most likely
to be affected; (2) acoustic propagation conditions that allow minimum
propagation loss, or transmission loss (TL) (i.e., longest acoustic
transmission ranges); and (3) time of year selected for maximum animal
abundance. These sites represent the upper bound of impacts (both in
terms of possible acoustic propagation conditions, and in terms of
marine mammal population and density) that can be expected from
operation of the SURTASS LFA sonar system. Thus, if SURTASS LFA sonar
operations are conducted in an area that was not acoustically modeled
in the Final EIS, the potential effects would most likely be less than
those analyzed for the most similar site in the analyses.
[[Page 46884]]
The assumptions of the Final EIS are still valid and there are no new
data to contradict the conclusions made in the Potential Impacts on
Marine Mammals (Chapter 4) in the Final EIS. The chapter on impacts to
marine mammals was incorporated by reference into the Navy's Final
SEIS.
LFS SRP
The goal of the 1997-1998 LFS SRP was to demonstrate the avoidance
reaction of sensitive marine mammal species during critical
biologically important behavior to the low frequency underwater sound
produced by the LFA sonar system. Testing was conducted in three phases
as summarized here from Clark et al. (1999).
Phase I was conducted in September through October 1997. The
objective of Phase I was to determine whether exposure to low frequency
sounds elicited disturbance reactions from feeding blue and fin whales.
The goal was to characterize how whale reactions to the sounds vary,
depending on: (1) The received level of the sound; (2) changes in the
received level; and (3) whether the system was operating at a
relatively constant distance or approaching the whale. Full and reduced
LFA sonar source power transmissions were used. The highest received
levels at the animals were estimated to be 148 to 155 dB. In 19 focal
animal observations (4 blue and 15 fin whales), no overt behavioral
responses were observed. No changes in whale distribution could be
related to LFA sonar operations, and whale the distributions correlated
with the distribution of food.
Phase II was conducted in January 1998. The objectives were to
quantify responses of migrating gray whales to low frequency sound
signals, compare whale responses to different RLs, determine whether
whales respond more strongly to RL, sound gradient, or distance from
the source, and to compare whale avoidance responses to an LF source in
the center of the migration corridor versus in the offshore portion of
the migration corridor. A single source was used to broadcast LFA sonar
sounds up to 200 dB. Whales showed some avoidance responses when the
source was moored 1 mi (1.8 km) offshore, in the migration path, but
returned to their migration path when they were a few kilometers from
the source. When the source was moored 2 mi (3.7 km) offshore,
responses were much less, even when the source level was increased to
200 dB, to achieve the same RL for most whales in the middle of the
migration corridor. Also, offshore whales did not seem to avoid the
louder offshore source.
Phase III was conducted from February to March 1998. The objectives
were to assess the potential effects of LFA sonar signals on behavior,
vocalization and movement of humpback whales off the Kona coast in
Hawaii. The maximum exposure levels in this phase were as high as 152
dB. Approximately half of the whales observed visually ceased their
song during the transmissions, but many of them did so while joining a
group of whales, which is the time that singing whales usually stop
their songs naturally. All singers who interrupted their songs were
observed to resume singing within tens of minutes. The analysis of one
data set showed that whales increased their song lengths during LFA
sonar transmissions, but a second analysis indicated that song length
changes were more complicated and depended on the portion of the song
that was overlapped by LFA sonar transmissions. Overall patterns of
singer and cow-calf abundance were the same throughout the experiments
as they had been during several years of prior study.
Risk Analysis
To determine the potential impacts that exposure to LF sound from
SURTASS LFA sonar operations could have on marine mammals, biological
risk standards were defined by the Navy with associated measurement
parameters. Based on the MMPA, the potential for biological risk was
defined as the probability for injury (Level A) or behavioral (Level B)
harassment of marine mammals. In this analysis, behavioral (Level B)
harassment is defined as a significant disturbance in a biologically
important behavior (also referred to as a biologically significant
response). NMFS believes that this is equivalent to the MMPA definition
of Level B harassment for military readiness activities. The potential
for biological risk is a function of an animal's exposure to a sound
that would potentially cause hearing, behavioral, psychological or
physiological effects. The measurement parameters for determining
exposure were RLs in dB, the pulse repetition interval (time between
pings), and the number of pings received.
Before the biological risk standards could be applied to realistic
SURTASS LFA sonar operational scenarios, two factors had to be
considered by the Navy: (1) How does risk vary with repeated sound
exposure? and (2) how does risk vary with RL? The Navy addressed these
questions by developing a function that translates the history of
repeated exposures (as calculated in the AIM) into an equivalent RL for
a single exposure with a comparable risk. This dual-question method is
similar to those adopted by previous studies of risk to human hearing
(Richardson et al., 1995; Crocker, 1997).
It is intuitive to assume that effects on marine mammals would be
greater with repeated exposures than for a single ping. However, no
published data on repeated exposures of LF sound on marine mammals
exist. Based on discussions in Richardson et al. (1995) and consistent
with Crocker (1997), the Navy determined that the best scientific
information available is based on the potential for effects of repeated
exposure on human models.
The formula L + 5 log10(N) (where L = ping level in dB and N is the
number of pings) defines the single ping equivalent (SPE). This formula
is considered appropriate for assessing the risk to a marine mammal of
a significant disturbance of a biologically important behavior from LF
sound like SURTASS LFA sonar transmissions.
Behavioral Harassment
For reasons explained in detail in the Final EIS (Section 4.2.5),
the Navy interpreted the results of the LFS SRP to support use of
unlimited exposure to 119 dB during an LFA sonar mission as the lowest
value for risk. Below this level, the risk of a biologically
significant behavioral response from marine mammals approaches zero. It
is important to note that risk varies with both received level and
number of exposures.
Because the LFS SRP did not document a biologically significant
response at maximum RLs up to 150 dB, the Navy determined there was a
2.5-percent risk of an animal incurring a disruption of biologically
important behavior at an SPL of 150 dB, a 50-percent risk at 165 dB,
and a 95-percent risk at 180 dB. For more detailed information, see
Chapter 4.2.5 of the Final EIS and Navy's Technical Report 1
(Navy, 2001). The Navy used this risk continuum analysis as an
alternative to an all-or-nothing use of standard thresholds for the
onset of behavioral change or injury. NMFS has reviewed and agrees with
this approach. The subsequent discussion of risk function emphasizes
the advantages of using a smoothly varying model of biological risk in
relation to sound exposure. These results are analogous to dose-
response curves that are accepted as the best practice in disciplines
such as epidemiology, toxicology, and pharmacology.
[[Page 46885]]
Changes in Hearing Sensitivity
In NMFS's 2002 rule, NMFS and the Navy based their estimate of take
by injury or the significant potential for such take (Level A
harassment) on the criterion of 180 dB. NMFS continues to believe this
is a scientifically supportable value for preventing auditory injury or
the significant potential for such injury (Level A harassment), as it
represents a value less than where the potential onset of a minor TTS
in hearing might occur based on Schlundt et al. (2000) research (see
Navy Final Comprehensive Report Tables 5 through 8). Also, an SPL of
180 dB is considered a scientifically supportable level for preventing
auditory injury because there is general scientific agreement with
NMFS's position that TTS is not an injury (i.e., does not result in
tissue damage), but rather a temporary impairment to hearing (i.e.,
results in an increased elevation or decreased sensitivity in hearing)
that may last for a few minutes to a few days, depending upon the level
and duration of exposure. In addition, there is no evidence that TTS
would occur in marine mammals at an SPL of 180 dB. In fact, Schlundt et
al. (2000) indicates that onset TTS for at least some species occurs at
significantly higher SPLs.
Schlundt et al.'s (2000) measurement with bottlenose dolphins and
belugas at 1-second signal duration implies that the TTS threshold for
a 100-second signal would be approximately 184 dB (Table 1-4, Final
EIS). For the 400-Hz signal, Schlundt et al. found no TTS at 193 dB,
the highest level of exposure. Therefore, NMFS believes that
establishing onset TTS as the upper bound of Level B harassment, but
using 180 dB as the beginning of the zone for establishing mitigation
measures to prevent auditory injury, is warranted by the science.
With three levels of mitigation monitoring for detecting marine
mammals (described later in this document), NMFS and the Navy believe
it is unlikely that any marine mammal would be exposed to received
levels of 180 dB before being detected and the SURTASS LFA sonar shut
down. However, because the probability is not zero, the Navy has
included Level A harassment in its authorization request.
Unlike with behavioral responses, an ``injury continuum'' is not
necessary because of the very low numbers of individual marine mammals
that could potentially experience high received sound levels, and the
high level of effectiveness of the monitoring and shutdown protocols.
For this action, all marine mammals exposed to an SPL of 180 dB or
above are considered to be injured even though the best scientific data
available indicate a marine mammal would need to receive an SPL
significantly higher than 180 dB to be injured.
When SURTASS LFA sonar transmits, there is a boundary that encloses
a volume of water where received levels equal or exceed 180 dB, and a
volume of water outside this boundary where received levels are below
180 dB. In this analysis, the 180-dB SPL boundary is emphasized because
it represents a single-ping RL that is a scientifically supportable
estimate for the potential onset of injury. Therefore, the level of
risk for marine mammals depends on their location in relation to
SURTASS LFA sonar. Under this rule, a marine mammal would have to
receive one ping greater than or equal to 180 dB to be considered to
have been injured or have the potential to incur an injury.
Although TTS is not considered Level A harassment, PTS is
considered Level A harassment. The onset of PTS for marine mammals may
be 15-20 dB above TTS levels. However, mitigation measures, such as
mitigation zones and shutdown protocols, are required where there is
the potential for a marine mammal to incur TTS so as to prevent an
animal from incurring a PTS.
Potential for Non-Auditory Injury
Since the release of the Final EIS, an investigation by Cudahy and
Ellison (2002) hypothesized that the threshold for in vivo tissue
damage (including lung damage and hemorrhaging) from LF sound can be on
the order of 180 to 190 dB. Balance and equilibrium could be affected,
but may not result in injury. These effects are based on studies of
humans. Vestibular (balance and equilibrium) function was investigated
by the Navy during its Diver's Study and the results reported in LFS
SRP Technical Report 3. Measurable performance decrements in vestibular
function were observed for guinea pigs using 160 dB SPL signals at lung
resonance and 190 dB SPL signals at 500 Hz. Because guinea pigs are not
aquatic species, like humans, they are not as robust to pressure
changes as marine mammals and, therefore, are likely more susceptible
to injury at lower SPLs than marine mammals.
Presently, there is controversy among researchers over whether
marine mammals can suffer from decompression sickness. It is theorized
that this may be caused by diving and then surfacing too quickly,
forcing nitrogen bubbles to form in the bloodstream and tissues. Cox et
al. (2006) stated that gas-bubble disease, induced in supersaturated
tissues by a behavioral response to acoustic exposure, is a plausible
pathologic mechanism for the morbidity and mortality seen in cetaceans
associated with sonar exposure. The authors also stated that it is
premature to judge acoustically mediated bubble growth as a potential
mechanism and recommended further studies to investigate the
possibility.
As stated in Crum and Mao (1996) and as discussed in the Final EIS
(pages 10-137) and the Final SEIS (pages 4-31), researchers
hypothesized that RLs would have to exceed 190 dB for there to be the
possibility of non-auditory trauma due to supersaturation of gases in
the blood. Such non-auditory traumas are not expected to occur from
sound exposure below SPLs of 180 dB.
In light of the high detection rate of the high-frequency marine
mammal monitoring (HF/M3) sonar, ensuring required SURTASS LFA sonar
shutdown when any marine mammal approaches or enters the 180-dB
isopleth from LFA sonar, the risks of these traumas to a marine mammal
approach zero.
Additional research published in the peer-reviewed journal
Ultrasound in Medicine and Biology supports the 180-dB criterion for
injury as being a scientifically supportable level for assessing
potential non-auditory injury to marine mammals (Laurer et al., 2002).
Laurer et al. (2002) exposed rats to 5 minutes of continuous high-
intensity, low-frequency (underwater) sound (HI-LFS) either at 180 dB
SPL re 1 [mu]Pa at 150 Hz or 194 dB SPL re 1 [mu]Pa at 250 Hz, and
found no overt histological damage in brains of any group. Also, blood
gases, heart rate, and main arterial blood pressure were not
significantly influenced by HI-LFS, suggesting that there was no
pulmonary dysfunction due to exposure. This published paper was based
on work performed in support of Technical Report 3 of the
SURTASS LFA sonar Final EIS.
Strandings
Marine mammal strandings are not a rare occurrence in nature. The
Cetacean Stranding Database (http://www.legaard.org/strandings/index.html formerly http://www.strandings.net) registered over one
ne
hundred strandings worldwide in 2004. However, mass strandings,
particularly multi-species mass strandings, are relatively rare.
Acoustic systems are becoming increasingly implicated in marine mammal
strandings. In particular, a number of mass strandings have been linked
to mid-frequency sonars (see, e.g.
[[Page 46886]]
Joint Interim Report on the Bahamas Marine Mammal Stranding Event of
15-16 March 2000, DOC and DON, 2001). Many theories exist as to why
noise may be a factor in marine mammal strandings. It is theorized that
marine mammals become disoriented, or that the sound forces them to
surface too quickly, which may cause symptoms similar to decompression
sickness, or that they are physically injured by the sound pressure.
The biological mechanisms for effects that lead to strandings must be
determined through scientific research.
There is no record of SURTASS LFA sonar ever being implicated in
any stranding event since LFA sonar prototype systems were first
operated in the late 1980s. Moreover, the system acoustic
characteristics differ between LF and mid-frequency (MF) sonars: LFA
sonars use frequencies generally below 1,000 Hz, with relatively long
signals (pulses) on the order of 60 sec; while MF sonars use
frequencies greater than 1,000 Hz, with relatively short signals on the
order of 1 sec. Cox et al. (2006) provided a summary of common features
shared by the strandings events in Greece (1996), Bahamas (2000), and
Canary Islands (2002). These included operation of MF sonar, deep water
close to land (such as offshore canyons), presence of an acoustic
waveguide (surface duct conditions), and periodic sequences of
transient pulses (i.e., rapid onset and decay times) generated at
depths less than 10 m (32.8 ft) by sound sources moving at speeds of
2.6 m/s (5.1 knots) or more during sonar operations (D'Spain et al.,
2006). These features do not relate to LFA sonar operations. First, no
MF-sonar component will be in operation. Second, the SURTASS LFA sonar
vessel operates with a horizontal line array of 1,500 m (4,921 ft)
length at depths below 150 m (492 ft) and a vertical line array (LFA
sonar source) at depths greater than 100 m (328 ft). Third, operations
are limited by mitigation protocols to at least 22 km (12 nm) offshore.
For these reasons, SURTASS LFA sonar cannot be operated in deep water
that is close to land. Also, the LFA sonar signal is transmitted at
depths well below 10 m (32.8 ft), and the vessel has a slow speed of
advance of 1.5 m/s (3 knots).
While there was an LF component in the Greek stranding in 1996,
only mid-frequency components were present in the strandings in the
Bahamas in 2000, Madeira 2000, and Canaries in 2002. This supports the
conclusion that the LF component in the Greek stranding was not
causative (ICES, 2005; Cox et al., 2006). In its discussion of the
Bahamas stranding, Cox et al. (2006) stated: ``The event raised the
question of whether the mid-frequency component of the sonar in Greece
in 1996 was implicated in the stranding, rather than the low-frequency
component proposed by Frantzis (1998).'' The ICES in its ``Report of
the Ad-Hoc Group on the Impacts of Sonar on Cetaceans and Fish'' raised
the same issues as Cox et al., stating that the consistent association
of MF sonar in the Bahamas, Madeira, and Canary Islands strandings
suggests that it was the MF component, not the LF component, in the
NATO sonar that triggered the Greek stranding of 1996 (ICES, 2005). The
ICES (2005) report concluded that no strandings, injury, or major
behavioral changes have been associated with the exclusive use of LF
sonar.
Beaked whales have been the subject of particular concern in
connection with strandings. Like most odontocetes, they have relatively
sharply decreasing hearing sensitivity below 2 kHz (Cook et al. (2006),
Richardson et al. (1995) and Finneran et al. (2002)). The SURTASS LFA
sonar source frequency is below 500 Hz. If a cetacean cannot hear a
sound or hears it poorly, the sound is unlikely to have a significant
behavioral impact (Ketten, 2001). Therefore, it is unlikely that LF
transmissions from LFA sonar would induce behavioral reactions from
animals that have poor LF hearing. Though highly unlikely, the sounds
could damage tissues even if the animal does not hear the sound, but
this would have to be within 1,000 m (3,280 ft) of the array, where
detection would be very likely, triggering shutdown.
Estimates of Potential Effects on Marine Mammals
The effects on marine mammals from operation of SURTASS LFA sonar
will not be the lethal removal of animals. In addition, while possible,
Level A harassment, if it occurs at all, is expected to be so minimal
as to have no effect on rates of reproduction or survival of affected
marine mammal species. Based on AIM modeling results, the primary
effects would be the potential for Level B harassment. The Final SEIS
Subchapter 4.4 provides the risk assessment methodology applied to
SURTASS LFA sonar operations for the annual LOA applications for
proposed operational areas.
Tables 4.4-2 through 4.4-10 in the Final SEIS provide, through a
case study based on the results of the Navy's 2005-2006 LOA, estimates
of the percentage of stocks potentially affected for SURTASS LFA sonar
operations, which are based on reasonable and realistic estimates of
the potential effects to marine mammal stocks specific to the potential
mission areas. Also, Tables 5 through 8 in the Navy's Final
Comprehensive Report for the 2002-2007 rule provide annual total
estimates of percentages of marine mammal stocks potentially affected
annually during the first four years of LFA sonar operations, based on
actual operations during the period of the LOAs.
The scenarios chosen by the Navy are not the only possible
combinations of areas where the SURTASS LFA sonar will operate. The
potential effects from other scenarios can be estimated by making a
best prediction of the areas in which the Navy would conduct SURTASS
LFA sonar operations annually in each oceanic basin area, determining
from Tables 4.4-2 through 4.4-10 in the Final SEIS the percentage of
each stock that may potentially be affected, and adding those
percentages together for each affected stock. Tables 5-8 in the Navy's
Comprehensive Report indicate that annually Level B harassment may
affect 0 to 6 percent for most marine mammal stocks, rising to just
over 11 percent annually for other species (e.g., common dolphins (6.4
percent), Risso's dolphins (6-8 percent), short-finned pilot whales (6
to 9 percent), false killer whales (5 to 10 percent), Pacific white-
sided dolphins (6 to 11 percent) and melon-headed whales (11.2
percent)).
Also, using updated modeling where appropriate, the Navy will rerun
AIM when planning missions and, if necessary, modify annual LOA
requests with an analysis of take estimates prior to any mission in a
new/different area. For this rule, NMFS is adopting the Navy estimates
shown in Final SEIS (Tables 4.4-2 through 4.4-10) as the best
scientific information currently available.
As with the 2002 rule, Navy will limit operation of LFA sonar to
ensure no stocks will be subject to more than 12 percent of takes (by
Level B harassment) annually, although most stocks are estimated to
incur a lower percentage of takes. This per-stock cap applies
regardless of the number of ships operating with LFA sonar or the
overall increased number of hours of LFA sonar operations. The Navy
will use the 12 percent take cap to guide its mission planning and
annual LOA applications.
Mitigation for Marine Mammals
NMFS is requiring the same visual, passive acoustic, and active
acoustic monitoring of the area surrounding the SURTASS LFA sonar
array, as required for the current 2002-2007 rule and LOAs, to prevent
the incidental injury of marine mammals that might enter the 180-dB
isopleth from the SURTASS
[[Page 46887]]
LFA sonar. These three monitoring systems are described in the next
section of this document. NMFS has implemented the same protocols as in
the 2002-2007 rule. Prior to each active sonar exercise, the distance
from the SURTASS LFA sonar source to the 180-dB isopleth will be
determined. If, through monitoring, a marine mammal is detected within
the 180-dB isopleth, the Navy proposes to shut down or immediately
suspend SURTASS LFA sonar transmissions. Transmissions may commence/
resume 15 minutes after the marine mammal has left the area of the 180-
dB isopleth or there is no further detection of the animal within the
180-dB isopleth. The protocol established by the Navy for implementing
this temporary shut-down is described in the application. As an added
safety measure, NMFS is again requiring a ``buffer zone'' extending an
additional 1 km (0.54 nm) beyond the 180-dB isopleth. This 180-dB plus
1 km (0.54 nm) distance will be the established mitigation zone for
that exercise. If a marine mammal is detected by the HF/M3 sonar, the
SURTASS LFA sonar will be either turned off or not turned on. This is
an effective mitigation measure since testing of the HF/M3 sonar
indicates effective levels of detection up to 2 km (1.1 nm). At 2 km
(1.1 nm), the SPL from the SURTASS LFA sonar will be approximately 174
dB, significantly below the 180 dB threshold for estimating onset of
injury. SURTASS LFA sonar operators would be required to estimate SPLs
before and during each operation to provide the information necessary
to modify the operation, including delay or suspension of
transmissions, so as not to exceed the mitigation sound field criteria.
In addition to establishing a mitigation zone at 180 dB plus 1 km
(0.54 nm) to protect marine mammals, the Navy has established a
mitigation zone for human divers at 145 dB re 1 microPa(rms) around all
known human commercial and recreational diving sites. Although this
geographic restriction is intended to protect human divers, it will
also reduce the LF sound levels received by marine mammals located in
the vicinity of known dive sites.
The Navy also recommended establishing OBIAs for marine mammal
protection in its Final EIS and SEIS. The Navy evaluated nine sites in
its Final EIS and SEIS where marine animals of concern (marine animals
listed under the ESA and other marine mammals) congregate to carry out
biologically important activities.
Based on the Navy's evaluation, NMFS has designated these nine
sites as OBIAs for LFA sonar. The nine areas are: (1) The North
American East Coast between 28[deg] N. and 50[deg] N. from west of
40[deg] W. to the 200-m (656-ft) isobath year-round; (2) the Antarctic
Convergence Zone, from 30[deg] E. to 80[deg] E. to 45[deg] S., from
80[deg] E. to 150[deg] E. to 55[deg] S., from 150[deg] E. to 50[deg] W.
to 60[deg] S., from 50[deg] W to 30[deg] E. to 55[deg] S. from October
through March; (3) the Costa Rica Dome, centered at 9[deg] N. and
88[deg] W., year-round; (4) Hawaiian Islands Humpback Whale National
Marine Sanctuary-Penguin Bank, centered at 21[deg] N. and 157[deg] 30'
W. from November 1 through May 1; (5) Cordell Bank National Marine
Sanctuary, boundaries in accordance 15 CFR 922.110 year-round; (6) Gulf
of the Farallones National Marine Sanctuary, boundaries in accordance
15 CFR 922.80 year-round; (7) Monterey Bay National Marine Sanctuary,
boundaries in accordance with 15 CFR 922.30 year-round; (8) Olympic
Coast National Marine Sanctuary, boundaries within 23 nm of the coast
from 47[deg]07' N. to 48[deg]30' N. latitude in December, January,
March, and May; and (9) Flower Garden Banks National Marine Sanctuary,
boundaries in accordance with 15 CFR 922.120 year-round.
NMFS has also designated an additional OBIA that was recommended by
several commenters on the Draft SEIS: The Gully with boundaries at
44[deg]13' N., 59[deg]06' W. to 43[deg]47' N., 58[deg]35' W. to
43[deg]35' N., 58[deg]35' W. to 43[deg]35' N., 59[deg]08' W. to
44[deg]06' N., 59[deg]20' W., year round. NMFS believes this area is
biologically important for marine mammals, based on its importance as
habitat for several species of marine mammals, particularly the
northern bottlenose whale.
NMFS'' proposed rule solicited public comments and information on
marine mammal distribution, densities, and the specific biologically
important activities that take place in the Northwestern Hawaiian
Islands to determine whether certain areas should be designated as
OBIAs. We did not receive public comment on this issue. Any additional
OBIA designations would be made through a separate rulemaking process.
NMFS is continuing the system established in the 2002-2007 rule for
expanding the number of OBIAs, as described later in this document.
While retaining the requirement to provide notice and an opportunity to
comment, this final rule eliminates the specific length of time for
public comment on proposed OBIAs. OBIAs are not intended to apply to
other Navy activities and sonar operations, but rather as a mitigation
measure to reduce incidental takings by SURTASS LFA sonar.
These regulations require the Navy to refrain from operating the
SURTASS LFA sonar within any OBIA and requires that the SURTASS LFA
sonar vessel ensures that the 180 dB (re 1 microPa(rms)) isopleth
remains at least 1 km (0.54 nm) seaward of the outer perimeter of the
OBIA.
Marine Mammal Monitoring
In order to minimize risks to marine mammals that may be present in
waters surrounding SURTASS LFA sonar, NMFS is again requiring the Navy
to: (1) Conduct visual monitoring from the ship's bridge during
daylight hours, (2) use passive SURTASS sonar to listen for vocalizing
marine mammals; and (3) use high frequency active sonar (i.e., similar
to a commercial fish finder) to monitor/locate/track marine mammals in
relation to the SURTASS LFA sonar vessel and the sound field produced
by the SURTASS LFA sonar source array.
Through observation, acoustic tracking and implementation of shut-
down criteria, the Navy will ensure, to the greatest extent
practicable, that no marine mammals approach the SURTASS LFA sonar
source close enough to be subjected to potentially injurious sound
levels (inside the 180-dB sound field; approximately 1 km (0.54 nm)
from the source). In the Navy's Final EIS, as reanalyzed in the Final
Comprehensive Report for SURTASS LFA sonar, the Navy assessed
mitigation effectiveness. The overall effectiveness of detecting a
marine mammal approaching the 180-dB sound field of the source array by
at least one of these monitoring methods is above 95 percent. This
value is supported by analyses of field data in a sampling of 6
missions between June 2004 and February 2006 (see the Navy's Final
Comprehensive Report for LFA sonar).
The results of the visual, passive, and active monitoring for each
LOA are discussed in the Annual Reports (most recently, Annual Report
5, 2007, Chapter 4). Mitigation effectiveness is described in Chapter 4
for the Final Comprehensive Report (2007) and in the Annual Reports.
Visual monitoring consists of daylight observations for marine
mammals from the vessel. Daylight is defined as 30 minutes before
sunrise until 30 minutes after sunset. Visual monitoring would begin 30
minutes before sunrise or 30 minutes before the SURTASS LFA sonar is
deployed. Monitoring would continue until 30 minutes after sunset or
until the SURTASS LFA sonar is recovered. Observations will be made by
personnel trained in detecting and identifying marine mammals. Marine
mammal biologists qualified in conducting at-sea
[[Page 46888]]
marine mammal visual monitoring from surface vessels train and qualify
designated ship personnel to conduct at-sea visual monitoring. The
objective of these observations is to maintain a track of marine
mammals observed and to ensure that none approach the source close
enough to enter the LFA sonar mitigation zone (including the buffer
zone).
These personnel would maintain a topside watch and marine mammal
observation log during operations that employ SURTASS LFA sonar in the
active mode. The numbers and identification of marine mammals sighted,
as well as any unusual behavior, will be entered into the log. A
designated ship's officer will monitor the conduct of the visual
watches and periodically review the log entries. There are two
potential visual monitoring scenarios.
First, if a marine mammal is sighted outside of the LFA sonar
mitigation zone, the observer will notify the Officer-in-Charge (OIC).
The OIC then notifies the HF/M3 sonar operator to determine the range
and projected track of the animal. If it is determined the animal will
enter the LFA sonar mitigation zone, the OIC will order the delay or
suspension of SURTASS LFA sonar transmissions when the animal enters
the LFA sonar mitigation zone. Second, if the animal is visually
observed within the mitigation zone, the OIC will order the immediate
delay or suspension of SURTASS LFA sonar transmissions. The observer
will continue visual monitoring/recording until the animal is no longer
seen.
Passive acoustic monitoring is conducted when SURTASS is deployed,
using the SURTASS towed horizontal line array to listen for vocalizing
marine mammals as an indicator of their presence. If the sound is
estimated to be from a marine mammal that may be in the SURTASS LFA
sonar mitigation zone, the technician will notify the OIC who will
alert the HF/M3 sonar operator and visual observers. If a marine mammal
is detected within or approaching the mitigation zone prior to or
during transmissions, the OIC will order the delay or suspension of
SURTASS LFA sonar transmissions.
HF-active acoustic monitoring uses the HF/M3 sonar to detect,
locate, and track marine mammals that could pass close enough to the
SURTASS LFA sonar array to enter the LFA sonar mitigation zone. HF
acoustic monitoring will begin 30 minutes before the first SURTASS LFA
sonar transmission of a given mission is scheduled to commence and
continue until transmissions are terminated. Prior to full-power
operations, the HF/M3 sonar power level is ramped up over a period of 5
min from 180 dB SL in 10-dB increments until full power (if required)
is attained to ensure that there are no inadvertent exposures of local
animals to RLs greater than 180 dB from the HF/M3 sonar. There are two
potential scenarios for mitigation via active acoustic monitoring.
First, if a ``contact'' is detected outside the LFA sonar
mitigation zone, the HF/M3 sonar operator determines the range and
projected track of the animal. If it is determined that the animal will
enter the LFA sonar mitigation zone, the sonar operator notifies the
OIC. The OIC then orders the delay or suspension of transmissions when
the animal is predicted to enter the LFA sonar mitigation zone. If a
contact is detected by the HF/M3 sonar within the LFA sonar mitigation
zone, the observer notifies the OIC who promptly orders the immediate
delay or suspension of transmissions.
All contacts will be recorded in the log and provided as part of
the Long-Term Monitoring (LTM) Program to monitor for potential long-
term environmental effects.
Research
The Navy spends approximately $10 to 14 million annually on marine
mammal research programs. These research programs provide a means of
learning about potential effects of anthropogenic underwater sound on
marine mammals (including long-term) and ways to mitigate potential
effects. During the first 4 years of LFA sonar operations, the Navy
conducted research on several research areas. Table 9 in the Navy's
Final Comprehensive Report for SURTASS LFA sonar provides the status of
the research that is planned or underway.
NMFS is requiring the Navy to continue researching the impacts of
LF sounds on marine mammals to supplement its monitoring and increase
knowledge of the species, and coordinate with others on additional
research opportunities and activities. This includes cumulative impact
analyses of the annual takes of marine mammals over the next 5 years
and the continuation of scientific data collection during SURTASS LFA
sonar operations.
NMFS recommends that the Navy conduct, or continue to conduct, the
following research regarding SURTASS LFA sonar over the second 5-year
authorization period:
1. Systematically observe SURTASS LFA sonar training exercises for
injured or disabled marine mammals.
2. Compare the effectiveness of the three forms of mitigation
(visual, passive acoustic, HF/M3 sonar).
3. Conduct research on the responses of deep-diving odontocete
whales to LF-sonar signals. These species are believed to be less
sensitive to LF-sonar sounds than the species studied prior to the LFS
SRP. However, enough questions exist that these species should be
studied further. The Navy has applied for a Scientific Research Permit
under section 104 of the MMPA to conduct a behavioral response study on
deep-diving cetacean species exposed to natural and artificial
underwater sounds and quantify exposure conditions associated with
various effects (72 FR 19181, April 17, 2007).
4. Conduct research on the habitat preferences of beaked whales.
5. Conduct passive acoustic monitoring using bottom-mounted
hydrophones before, during, and after LF sonar operations for the
possible silencing of calls of large whales.
6. Continue to evaluate the HF/M3 mitigation sonar. This is the
primary means of mitigation, and its efficacy must continue to be
demonstrated.
7. Continue to evaluate improvements in passive sonar capabilities.
Reporting
During routine operations of SURTASS LFA sonar, technical and
environmental data would be collected and recorded, which, along with
research, are part of the Navy's LTM Program. These would include data
from visual and acoustic monitoring, ocean environmental measurements,
and technical operational inputs.
First, a mission report would be provided to NMFS on a quarterly
basis, with the report including all active-mode missions completed 30
days or more prior to the date of the deadline for the report. Second,
the Navy would submit an annual report no later than 45 days after
expiration of an LOA. Third, the Navy would submit a Final
Comprehensive Report at least 240 days prior to expiration of these
regulations. These reports are summarized here.
Quarterly Report--On a quarterly basis, the Navy would provide NMFS
with a classified report that includes all active-mode missions
completed 30 days or more prior to the date of the deadline for the
report. The Navy must submit its quarterly mission reports to NMFS, no
later than 30 days after the end of each quarter beginning on the date
of effectiveness of an LOA or as specified in the appropriate LOA.
Specifically, these reports will include dates/times of exercises,
location of vessel, LOA province (as set forth in
[[Page 46889]]
Longhurst (1998)), location of the mitigation zone in relation to the
LFA sonar array, marine mammal observations, and records of any delays
or suspensions of operations. Marine mammal observations would include
animal type and/or species, number of animals sighted by species, date
and time of observations, type of detection (visual, passive acoustic,
HF/M3 sonar), the animal's bearing and range from vessel, behavior, and
remarks/narrative (as necessary). The report would include the Navy's
analysis of whether any Level A and/or Level B harassment taking
occurred within the SURTASS LFA sonar 180-dB and 1 km (0.54 nm)
mitigation zone and, if so, estimates of the percentage of marine
mammal stocks affected (both for the quarter and cumulatively (to date)
for the year covered by the LOA) by SURTASS LFA sonar operations. This
analysis would include estimates of Level A and Level B harassment
takes of marine mammals for within the mitigation zone, using
predictive modeling based on operating locations, dates/times of
operations, system characteristics, oceanographic environmental
conditions, and animal demographics. In the event that no SURTASS LFA
sonar missions are completed during a quarter, a report of negative
activity would be provided.
Annual Report--The annual report would provide NMFS with an
unclassified summary of the year's quarterly reports and will include
the Navy's analysis of whether any Level A and/or Level B harassment
takings of marine mammals occurred within the SURTASS LFA sonar's 180-
dB and 1 km (0.54 nm) mitigation zones and, if so, estimates of the
percentage of marine mammal stocks affected by SURTASS LFA sonar
operations. This analysis would include estimates for both within and
outside the 180-dB and 1 km (0.54 nm) mitigation zone, using predictive
modeling based on operating locations, dates/times of operations,
system characteristics, oceanographic environmental conditions, and
animal demographics.
The annual report would also include: (1) Analysis of the
effectiveness of the mitigation measures with recommendations for
improvements where applicable; (2) assessment of any long-term effects
from SURTASS LFA sonar operations; and (3) any discernible or estimated
cumulative impacts from SURTASS LFA sonar operations.
Comprehensive Report--NMFS is requiring the Navy to provide NMFS
and the public with a final comprehensive report analyzing the impacts
of SURTASS LFA sonar on marine mammal species and stocks. This report,
which is due at least 240 days prior to expiration of these
regulations, would include an in-depth analysis of all monitoring and
Navy-supported research pertinent to SURTASS LFA sonar conducted during
the 5-year period of these regulations, a scientific assessment of
cumulative impacts on marine mammal stocks, and an analysis on the
advancement of alternative (passive) technologies as a replacement for
LFA sonar. This report would be an important document for NMFS' review
and assessment of impacts for any future rulemaking.
Annual reports and the Comprehensive Report will be posted on the
NMFS homepage (see ADDRESSES).
Modification to Mitigation Measures
Any substantial modifications to NMFS' mitigation, monitoring, and
reporting requirements will be proposed in the Federal Register with an
opportunity for public comment prior to implementation (unless an
emergency exists and modifications are necessary for the protection of
marine mammals).
Designation of Offshore Biologically Important Areas for Marine Mammals
In addition to NMFS designating OBIAs independently, this rule
describes a process for members of the public to petition NMFS to add
an area to the list of OBIAs for marine mammals. To qualify for
designation, an area must be of particular importance for marine
mammals as an area for feeding, breeding, calving, or migration, and
not simply an area occupied by marine mammals. The proposed area should
not be within a previously designated OBIA or other 180-dB exclusion
area. In order for NMFS to begin a rulemaking process for designating
OBIAs, proponents must petition NMFS and submit the information
described in 50 CFR 216.191(a). If NMFS makes a preliminary
determination that the area is biologically important for marine
mammals, NMFS will publish a Federal Register document proposing to add
the area as an OBIA. After review of public comments and information,
NMFS will make a final decision on whether to designate the area as an
OBIA and publish a Federal Register document of its decision. Proposals
for designation of areas will not affect the status of LOAs while the
rulemaking is in process.
Waiver of Delay in Effectiveness Date
NMFS has determined good cause exists to waive the delay in
effectiveness date for this final rule. Regulations governing the
current MMPA authorization for Navy SURTASS LFA sonar operations
expires on August 15, 2007. This final rule must therefore be effective
by August 16, 2007 to avoid a gap in SURTASS LFA sonar operations. The
Navy recently provided specific, credible, and verifiable information
indicating that activities may occur on or after August 16, 2007 such
that a gap in SURTASS LFA sonar operations would be detrimental to
national security and reduce protection of U.S. and Allied naval forces
from submarine threats. This rule, together with LOAs issued hereunder,
will afford the Navy lawful incidental take coverage for marine mammals
during SURTASS LFA sonar testing, training, and routine operations and
avoid any gap in operations. The required mitigation and monitoring,
which are designed to ensure the least practicable adverse impact on
affected species or stocks will ensure that SURTASS LFA sonar will have
a negligible impact on the affected species or stocks of marine
mammals.
Changes From the Proposed Rule
NMFS has amended the proposed rule to add a 1-km (0.5-nm) buffer to
the OBIA SPL restriction. Accordingly, the final rule requires the Navy
to ensure SPLs do not exceed 180 dB (re 1 microPa(rms)) at a distance
of 1km (0.5 nm) seaward of the outer perimeter of the OBIA. This
measure will limit SPLs within OBIA to less than approximately 174 dB.
These regulations require the Navy to refrain from operating the
SURTASS LFA sonar within any OBIA and further require the Navy to
ensure SPLs do not exceed 180 dB (re 1 microPa(rms)) at a distance of
1km (0.5 nm) seaward of the outer perimeter of the OBIA.
Determinations
Based on the scientific analyses detailed in the Navy application
and further supported by information and data contained in the Navy's
Final SEIS and Final EIS for SURTASS LFA sonar operations and
summarized in this rule, NMFS has determined that the incidental taking
of marine mammals resulting from SURTASS LFA sonar operations would
have a negligible impact on the affected marine mammal species or
stocks over the 5-year period of LFA sonar operations covered by these
regulations. That assessment is based on a number of factors: (1) The
best information available indicates that effects from SPLs less than
180 dB will be limited to short-term Level B behavioral harassment
averaging less than 12 percent annually for all affected marine mammal
species; (2) the
[[Page 46890]]
mitigation and monitoring is highly effective in preventing exposures
of 180 dB or greater; (3) the results of monitoring as described in the
Navy's Comprehensive Report supports the conclusion that takings will
be limited to Level B harassment and not have more than a negligible
impact on affected species or stocks of marine mammals; (4) the small
number of SURTASS LFA sonar systems (two systems in FY 2008 and FY 2009
(totaling 864 hours of operation annually), 3 in FY 2010 (totaling 1296
hours of operation annually), and 4 systems in FY 2011 and FY 20012
(totaling 1728 hours of operation annually)) that would be operating
world-wide; (5) that the LFA sonar vessel must be underway while
transmitting (in order to keep the receiver array deployed), limiting
the duration of exposure for marine mammals to those few minutes when
the SURTASS LFA sonar sound energy is moving through that part of the
water column inhabited by marine mammals; (6) in the case of
convergence zone (CZ) propagation, the characteristics of the acoustic
sound path, which deflect the sound below the water depth inhabited by
marine mammals for much of the sound propagation (see illustration 67
FR page 46715 (July 16, 2002); (7) the findings of the SRP on LF sounds
on marine mammals indicated no significant change in biologically
important behavior from exposure to sound levels up to 155 dB; and (8)
during the 40 LFA sonar missions between 2002 and 2006, there were only
three visual observations of marine mammals and only 71 detections by
the HF/M3 sonar, which all resulted in mitigation protocol suspensions
in operations. These measures all indicate that while marine mammals
will potentially be affected by the SURTASS LFA sonar sounds, these
impacts will be short-term behavioral effects and are not likely to
adversely affect marine mammal species or stocks through effects on
annual rates of reproduction or survival. In addition, mortality of
marine mammals is not expected to occur as a result of LFA sonar
operations and is not authorized in these regulations nor in any LOA
issued under this rule.
Finally, because SURTASS LFA sonar operations will not take place
in Arctic waters, it would not have an unmitigable adverse impact on
the availability of marine mammals for subsistence uses identified in
MMPA section 101(a)(5)(A)(i), 16 U.S.C. 1371(a) (5)(A)(i).
NEPA
On November 10, 2005 (70 FR 68443), the Environmental Protection
Agency (EPA) announced receipt of a Draft SEIS from the U.S. Navy on
the deployment of SURTASS LFA sonar. This Final SEIS incorporated by
reference the Navy's Final EIS on SURTASS LFA sonar deployment. The
public comment period on the Draft SEIS ended on February 10, 2006. On
May 4, 2007 (72 FR 25302), EPA announced receipt of a Final SEIS from
the U.S. Navy on the deployment of SURTASS LFA sonar. NMFS was a
cooperating agency, as defined by the Council on Environmental Quality
(40 CFR 1501.6), in the preparation of these documents. NMFS reviewed
the Navy's Final SEIS, adopted the Navy Final EIS, as provided for in
40 CFR 1506.3, and has determined it is unnecessary to prepare
additional NEPA analyses. The Navy's Final SEIS is available at: http://www.surtass-LFA
sonar-eis.com.
ESA
On June 9, 2006, the Navy submitted a Biological Assessment to NMFS
to initiate consultation under section 7 of the ESA for the 2007-2012
SURTASS LFA sonar activities and NMFS'' authorization for incidental
take under the MMPA. NMFS concluded consultation with the Navy on this
action on August xx, 2007. The conclusion of that consultation was that
operation of the SURTASS LFA sonar system for testing, training and
military operations and the issuance by NMFS of MMPA incidental take
authorizations for this activity are not likely to jeopardize the
continued existence of any endangered or threatened species under the
jurisdiction of NMFS or result in the destruction or adverse
modification of critical habitat.
Classification
This action has been determined to be significant for purposes of
Executive Order 12866.
The Chief Counsel for Regulation of the Department of Commerce
certified to the Chief Counsel for Advocacy of the Small Business
Administration at the proposed rule stage, that this action would not
have a significant economic impact on a substantial number of small
entities within the meaning of the Regulatory Flexibility Act. If
implemented, this rule would affect only the U.S. Navy which, by
definition, is not a small business. Because of this certification, a
regulatory flexibility analysis is not required.
List of Subjects in 50 CFR Part 216
Exports, Fish, Imports, Indians, Labeling, Marine mammals,
Penalties, Reporting and recordkeeping requirements, Seafood,
Transportation.
Dated: August 14, 2007.
William T. Hogarth,
Assistant Administrator for Fisheries, National Marine Fisheries
Service.
0
For reasons set forth in the preamble, 50 CFR part 216 is amended as
follows:
PART 216--REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE
MAMMALS
0
1. The authority citation for part 216 continues to read as follows:
Authority: 16 U.S.C. 1361 et seq., unless otherwise noted.
0
2. Subpart Q is added to part 216 to read as follows:
Subpart Q--Taking of Marine Mammals Incidental to Navy Operations of
Surveillance Towed Array Sensor System Low Frequency Active (SURTASS
LFA sonar) Sonar
Sec.
216.180 Specified activity.
216.181 Effective dates.
216.182 Permissible methods of taking.
216.183 Prohibitions.
216.184 Mitigation.
216.185 Requirements for monitoring.
216.186 Requirements for reporting.
216.187 Applications for Letters of Authorization.
216.188 Letters of Authorization.
216.189 Renewal of Letters of Authorization.
216.190 Modifications to Letters of Authorization.
216.191 Designation of Offshore Biologically Important Marine Mammal
Areas.
Subpart Q--Taking of Marine Mammals Incidental to Navy Operations
of Surveillance Towed Array Sensor System Low Frequency Active
(SURTASS LFA sonar) Sonar
Sec. 216.180 Specified activity.
Regulations in this subpart apply only to the incidental taking of
those marine mammal species specified in paragraph (b) of this section
by the U.S. Navy, Department of Defense, while engaged in the operation
of no more than four SURTASS LFA sonar systems conducting active sonar
operations, in areas specified in paragraph (a) of this section. The
authorized activities, as specified in a Letter of Authorization issued
under Sec. Sec. 216.106 and 216.188, include the transmission of low
frequency sounds from the SURTASS LFA sonar and the transmission of
high frequency sounds from the mitigation
[[Page 46891]]
sonar described in Sec. 216.185 during training, testing, and routine
military operations of SURTASS LFA sonar.
(a) With the exception of those areas specified in Sec.
216.183(d), the incidental taking by harassment may be authorized in
the areas (biomes, provinces, and subprovinces) described in Longhurst
(1998), as specified in a Letter of Authorization.
(b) The incidental take, by Level A and Level B harassment, of
marine mammals from the activity identified in this section is limited
to the following species and species groups:
(1) Mysticete whales--blue (Balaenoptera musculus), fin
(Balaenoptera physalus), minke (Balaenoptera acutorostrata), Bryde's
(Balaenoptera edeni), sei (Balaenoptera borealis), humpback (Megaptera
novaeangliae), North Atlantic right (Eubalaena glacialis), North
Pacific right (Eubalena japonica) southern right (Eubalaena australis),
pygmy right (Capera marginata), bowhead (Balaena mysticetus), and gray
(Eschrichtius robustus) whales.
(2) Odontocete whales--harbor porpoise (Phocoena phocoena),
spectacled porpoise (Phocoena dioptrica), beluga (Dephinapterus
leucas), Stenella spp., Risso's dolphin (Grampus griseus), rough-
toothed dolphin (Steno bredanensis), Fraser's dolphin (Lagenodelphis
hosei), northern right-whale dolphin (Lissodelphis borealis), southern
right whale dolphin (Lissodelphis peronii), short-beaked common dolphin
(Delphius delphis), long-beaked common dolphin (Delphinus capensis),
very long-beaked common dolphin (Delphinus tropicalis), Lagenorhynchus
spp., Cephalorhynchus spp., bottlenose dolphin (Tursiops truncatus),
Dall's porpoise (Phocoenoides dalli), melon-headed whale (Peponocephala
spp.), beaked whales (Berardius spp., Hyperoodon spp., Mesoplodon spp.,
Cuvier's beaked whale (Ziphius cavirostris), Shepard's beaked whale
(Tasmacetus shepherdi), Longman's beaked whale (Indopacetus pacificus),
killer whale (Orcinus orca), false killer whale (Pseudorca crassidens),
pygmy killer whale (Feresa attenuata), sperm whale (Physeter
macrocephalus), dwarf and pygmy sperm whales (Kogia simus and K.
breviceps), and short-finned and long-finned pilot whales (Globicephala
macrorhynchus and G. melas).
(3) Pinnipeds--hooded seal (Cystophora cristata), harbor seal
(Phoca vitulina), spotted seal (P. largha), ribbon seal (P. fasciata),
gray seal (Halichoerus grypus), elephant seal (Mirounga angustirostris
and M. leonina), Hawaiian monk seal (Monachus schauinslandi),
Mediterranean monk seal (Monachus monachus), northern fur seal
(Callorhinus ursinus), southern fur seal (Arctocephalus spp.), harp
seal (Phoca groenlandica), Galapagos sea lion (Zalophus californianus
wollebaeki), Japanese sea lion (Zalophus californianus japonicus),
Steller sea lion (Eumetopias jubatus), California sea lion (Zalophus
californianus), Australian sea lion (Neophoca cinerea), New Zealand sea
lion (Phocarctos hookeri), and South American sea lion (Otaria
flavescens).
Sec. 216.181 Effective dates.
Regulations in this subpart are effective from August 16, 2007
through August 15, 2012.
Sec. 216.182 Permissible methods of taking.
(a) Under Letters of Authorization issued pursuant to Sec. Sec.
216.106 and 216.188, the Holder of the Letter of Authorization may
incidentally, but not intentionally, take marine mammals by Level A and
Level B harassment within the areas described in Sec. 216.180(a),
provided the activity is in compliance with all terms, conditions, and
requirements of these regulations and the appropriate Letter of
Authorization.
(b) The activities identified in Sec. 216.180 must be conducted in
a manner that minimizes, to the greatest extent practicable, any
adverse impacts on marine mammals and their habitat.
Sec. 216.183 Prohibitions.
No person in connection with the activities described in Sec.
216.180 shall:
(a) Take any marine mammal not specified in Sec. 216.180(b);
(b) Take any marine mammal specified in Sec. 216.180(b) other than
by incidental, unintentional Level A and Level B harassment;
(c) Take a marine mammal specified in Sec. 216.180(b) if such
taking results in more than a negligible impact on the species or
stocks of such marine mammal; or
(d) Violate, or fail to comply with, the terms, conditions, and
requirements of the regulations in this subpart or any Letter of
Authorization issued under Sec. Sec. 216.106 and 216.188.
Sec. 216.184 Mitigation.
The activity identified in Sec. 216.180(a) must be conducted in a
manner that minimizes, to the greatest extent practicable, adverse
impacts on marine mammals and their habitats. When conducting
operations identified in Sec. 216.180, the mitigation measures
described in this section and in any Letter of Authorization issued
under Sec. Sec. 216.106 and 216.188 must be implemented.
(a) Through monitoring described under Sec. 216.185, the Holder of
a Letter of Authorization must act to ensure, to the greatest extent
practicable, that no marine mammal is subjected to a sound pressure
level of 180 dB or greater.
(b) If a marine mammal is detected within or about to enter the
mitigation zone (the area subjected to sound pressure levels of 180 dB
or greater plus the 1 km (0.54 nm) buffer zone extending beyond the
180-dB zone), SURTASS LFA sonar transmissions will be immediately
delayed or suspended. Transmissions will not resume earlier than 15
minutes after:
(1) All marine mammals have left the area of the mitigation and
buffer zones; and
(2) There is no further detection of any marine mammal within the
mitigation and buffer zones as determined by the visual and/or passive
or active acoustic monitoring described in Sec. 216.185.
(c) The high-frequency marine mammal monitoring sonar (HF/M3)
described in Sec. 216.185 will be ramped-up slowly to operating levels
over a period of no less than 5 minutes:
(1) At least 30 minutes prior to any SURTASS LFA sonar
transmissions;
(2) Prior to any SURTASS LFA sonar calibrations or testings that
are not part of regular SURTASS LFA sonar transmissions described in
paragraph (c)(1) of this section; and
(3) Anytime after the HF/M3 source has been powered down for more
than 2 minutes.
(d) The HF/M3 sound pressure level will not be increased once a
marine mammal is detected; ramp-up may resume once marine mammals are
no longer detected.
(e) The Holder of a Letter of Authorization will not operate the
SURTASS LFA sonar, such that:
(1) the SURTASS LFA sonar sound field exceeds 180 dB (re 1
microPa(rms)) at a distance less than 12 nautical miles (nm) (22
kilometers (km)) from any coastline, including offshore islands;
(2) the SURTASS LFA sonar sound field exceeds 180 db (re 1
microPa(rms)) at a distance of 1 km (0.5 nm) seaward of the outer
perimeter of any offshore biologically important area designated in
216.184(f) during the biologically important period specified.
(f) The following areas have been designated by NMFS as Offshore
Biologically Important Areas (OBIAs) for marine mammals (by season if
appropriate):
[[Page 46892]]
------------------------------------------------------------------------
Name of area Location of area Months of importance
------------------------------------------------------------------------
(1) 200-m isobath North From 28[deg] N. to Year-round.
American East Coast. 50[deg] N., west of
40[deg] W.
(2) Antarctic Convergence 30[deg] E. to October 1-March 31.
Zone. 80[deg] E. to
45[deg]; 80[deg] E.
to 150[deg] E. to
55[deg]; S.
150[deg] E. to
50[deg] W. to
60[deg] S.; 50[deg]
W. to 30[deg] E. to
50[deg] S.
(3) Costa Rica Dome......... Centered at 9[deg] Year-round.
N. and 88[deg] W.
(4) Hawaiian Islands Centered at 21[deg] November 1 through
Humpback Whale National N. and 157[deg] 30' May 1.
Marine Sanctuary-Penguin W.
Bank.
(5) Cordell Bank National Boundaries in Year-round.
Marine Sanctuary. accordance with 15
CFR 922.110.
(6) Gulf of the Farallones Boundaries in Year-round.
National Marine Sanctuary. accordance with 15
CFR 922.80.
(7) Monterey Bay National Boundaries in Year-round.
Marine Sanctuary. accordance with 15
CFR 922.30.
(8) Olympic Coast National Boundaries within 23 December January,
Marine Sanctuary. nm of the coast March and May.
from 47[deg]07' N.
to 48[deg]30' N.
latitude.
(9) Flower Garden Banks Boundaries in Year-round.
National Marine Sanctuary. accordance with 15
CFR 922.120.
(10) The Gully.............. 44[deg]13' N., Year-round.
59[deg]06' W. to
43[deg]47' N.;
58[deg]35' W. to
43[deg]35' N.;
58[deg]35' W. to
43[deg]35' N.;
59[deg]08' W. to
44[deg]06' N.;
59[deg]20' W.
------------------------------------------------------------------------
Sec. 216.185 Requirements for monitoring.
(a) In order to mitigate the taking of marine mammals by SURTASS
LFA sonar to the greatest extent practicable, the Holder of a Letter of
Authorization issued pursuant to Sec. Sec. 216.106 and 216.188 must:
(1) Conduct visual monitoring from the ship's bridge during all
daylight hours (30 minutes before sunrise until 30 minutes after
sunset);
(2) Use low frequency passive SURTASS sonar to listen for
vocalizing marine mammals; and
(3) Use the HF/M3 (high frequency) sonar developed to locate and
track marine mammals in relation to the SURTASS LFA sonar vessel and
the sound field produced by the SURTASS LFA sonar source array.
(b) Monitoring under paragraph (a) of this section must:
(1) Commence at least 30 minutes before the first SURTASS LFA sonar
transmission;
(2) Continue between transmission pings; and
(3) Continue either for at least 15 minutes after completion of the
SURTASS LFA sonar transmission exercise, or, if marine mammals are
exhibiting unusual changes in behavioral patterns, for a period of time
until behavior patterns return to normal or conditions prevent
continued observations;
(c) Holders of Letters of Authorization for activities described in
Sec. 216.180 are required to cooperate with the National Marine
Fisheries Service and any other federal agency for monitoring the
impacts of the activity on marine mammals.
(d) Holders of Letters of Authorization must designate qualified
on-site individuals to conduct the mitigation, monitoring and reporting
activities specified in the Letter of Authorization.
(e) Holders of Letters of Authorization must conduct all monitoring
required under the Letter of Authorization.
Sec. 216.186 Requirements for reporting.
(a) The Holder of the Letter of Authorization must submit quarterly
mission reports to the Director, Office of Protected Resources, NMFS,
no later than 30 days after the end of each quarter beginning on the
date of effectiveness of a Letter of Authorization or as specified in
the appropriate Letter of Authorization. Each quarterly mission report
will include all active-mode missions completed during that quarter. At
a minimum, each classified mission report must contain the following
information:
(1) Dates, times, and location of each vessel during each mission;
(2) Information on sonar transmissions during each mission;
(3) Results of the marine mammal monitoring program specified in
the Letter of Authorization; and
(4) Estimates of the percentages of marine mammal species and
stocks affected (both for the quarter and cumulatively for the year)
covered by the Letter of Authorization.
(b) The Holder of a Letter of Authorization must submit an annual
report to the Director, Office of Protected Resources, NMFS, no later
than 45 days after the expiration of a Letter of Authorization. This
report must contain all the information required by the Letter of
Authorization.
(c) A final comprehensive report must be submitted to the Director,
Office of Protected Resources, NMFS at least 240 days prior to
expiration of these regulations. In addition to containing all the
information required by any final year Letter of Authorization, this
report must contain an unclassified analysis of new passive sonar
technologies and an assessment of whether such a system is feasible as
an alternative to SURTASS LFA sonar.
Sec. 216.187 Applications for Letters of Authorization.
(a) To incidentally take marine mammals pursuant to these
regulations, the U.S. Navy authority conducting the activity identified
in Sec. 216.180 must apply for and obtain a Letter of Authorization in
accordance with Sec. 216.106.
(b) The application for a Letter of Authorization must be submitted
to the Director, Office of Protected Resources, NMFS, at least 60 days
before the date that either the vessel is scheduled to begin conducting
SURTASS LFA sonar operations or the previous Letter of Authorization is
scheduled to expire.
(c) All applications for a Letter of Authorization must include the
following information:
(1) The date(s), duration, and the area(s) where the vessel's
activity will occur;
(2) The species and/or stock(s) of marine mammals likely to be
found within each area;
(3) The type of incidental taking authorization requested (i.e.,
take by Level A and/or Level B harassment);
(4) The estimated percentage of marine mammal species/stocks
potentially affected in each area for the 12-month period of
effectiveness of the Letter of Authorization; and
(5) The means of accomplishing the necessary monitoring and
reporting that will result in increased knowledge of the species and
the level of taking or impacts on marine mammal populations.
[[Page 46893]]
(d) The National Marine Fisheries Service will review an
application for a Letter of Authorization in accordance with Sec.
216.104(b) and, if adequate and complete, issue a Letter of
Authorization.
Sec. 216.188 Letters of Authorization.
(a) A Letter of Authorization, unless suspended or revoked will be
valid for a period of time not to exceed one year, but may be renewed
annually subject to annual renewal conditions in Sec. 216.189.
(b) Each Letter of Authorization will set forth:
(1) Permissible methods of incidental taking;
(2) Authorized geographic areas for incidental takings;
(3) Means of effecting the least practicable adverse impact on the
species of marine mammals authorized for taking, their habitat, and the
availability of the species for subsistence uses; and
(4) Requirements for monitoring and reporting incidental takes.
(c) Issuance of each Letter of Authorization will be based on a
determination that the total number of marine mammals taken by the
activity specified in Sec. 216.180 as a whole will have no more than a
negligible impact on the species or stocks of affected marine
mammal(s), and that the total taking will not have an unmitigable
adverse impact on the availability of species or stocks of marine
mammals for taking for subsistence uses.
(d) Notice of issuance or denial of an application for a Letter of
Authorization will be published in the Federal Register within 30 days
of a determination.
Sec. 216.189 Renewal of Letters of Authorization.
(a) A Letter of Authorization issued for the activity identified in
Sec. 216.180 may be renewed annually upon:
(1) Notification to NMFS that the activity described in the
application submitted under Sec. 216.187 will be undertaken and that
there will not be a substantial modification to the described activity,
mitigation or monitoring undertaken during the upcoming season;
(2) Notification to NMFS of the information identified in Sec.
216.187(c), including the planned geographic area(s), and anticipated
duration of each SURTASS LFA sonar operation;
(3) Timely receipt of the monitoring reports required under Sec.
216.185, which have been reviewed by NMFS and determined to be
acceptable;
(4) A determination by NMFS that the mitigation, monitoring and
reporting measures required under Sec. Sec. 216.184 and 216.185 and
the previous Letter of Authorization were undertaken and will be
undertaken during the upcoming annual period of validity of a renewed
Letter of Authorization; and
(5) A determination by NMFS that the number of marine mammals taken
by the activity as a whole will have no more than a negligible impact
on the species or stock of affected marine mammal(s), and that the
total taking will not have an unmitigable adverse impact on the
availability of species or stocks of marine mammals for taking for
subsistence uses.
(b) If a request for a renewal of a Letter of Authorization
indicates that a substantial modification to the described work,
mitigation or monitoring will occur, or if NMFS proposes a substantial
modification to the Letter of Authorization, NMFS will provide a period
of 30 days for public review and comment on the proposed modification.
Amending the areas for upcoming SURTASS LFA sonar operations is not
considered a substantial modification to the Letter of Authorization.
(c) A notice of issuance or denial of a renewal of a Letter of
Authorization will be published in the Federal Register within 30 days
of a determination.
Sec. 216.190 Modifications to Letters of Authorization.
(a) Except as provided in paragraph (b) of this section, no
substantial modification (including withdrawal or suspension) to a
Letter of Authorization subject to the provisions of this subpart shall
be made by NMFS until after notification and an opportunity for public
comment has been provided. For purposes of this paragraph, a renewal of
a Letter of Authorization, without modification, except for the period
of validity and a listing of planned operating areas, or for moving the
authorized SURTASS LFA sonar system from one ship to another, is not
considered a substantial modification.
(b) If the National Marine Fisheries Service determines that an
emergency exists that poses a significant risk to the well-being of the
species or stocks of marine mammals specified in Sec. 216.180(b), a
Letter of Authorization may be substantially modified without prior
notice and opportunity for public comment. Notification will be
published in the Federal Register within 30 days of the action.
Sec. 216.191 Designation of Offshore Biologically Important Marine
Mammal Areas.
(a) Offshore biologically important areas for marine mammals may be
nominated under this paragraph by the National Marine Fisheries Service
or by members of the public.
(b) Proponents must petition NMFS by requesting an area be added to
the list of offshore biologically important areas in Sec. 216.184(f)
and submitting the following information:
(1) Geographic region proposed for consideration (including
geographic boundaries);
(2) A list of marine mammal species or stocks within the proposed
geographic region;
(3) Whether the proposal is for year-round designation or seasonal,
and if seasonal, months of years for proposed designation;
(4) Detailed information on the biology of marine mammals within
the area, including estimated population size, distribution, density,
status, and the principal biological activity during the proposed
period of designation sufficient for NMFS to make a preliminary
determination that the area is biologically important for marine
mammals; and
(5) Detailed information on the area with regard to its importance
for feeding, breeding, or migration for those species of marine mammals
that have the potential to be affected by low frequency sounds;
(c) Areas within 12 nm (22 km) of any coastline, including offshore
islands, or within non-operating areas for SURTASS LFA sonar are not
eligible for consideration.
(d) If a petition does not contain sufficient information for the
National Marine Fisheries Service to proceed, NMFS will determine
whether the nominated area warrants further study. If so, NMFS will
begin a scientific review of the area.
(e)(1) If through a petition or independently, NMFS makes a
preliminary determination that an offshore area is biologically
important for marine mammals and is not located within a previously
designated area, NMFS will publish a Federal Register notice proposing
to add the area to Sec. 216.184(f) and solicit public comment.
(2) The National Marine Fisheries Service will publish its final
determination in the Federal Register.
[FR Doc. 07-4044 Filed 8-15-07; 9:44 am]
BILLING CODE 3510-22-P