[Federal Register Volume 73, Number 121 (Monday, June 23, 2008)]
[Proposed Rules]
[Pages 35510-35577]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 08-1371]
[[Page 35509]]
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Part IV
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; U.S. Navy Training in the Hawaii
Range Complex; Proposed Rule
Federal Register / Vol. 73, No. 121 / Monday, June 23, 2008 /
Proposed Rules
[[Page 35510]]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 216
[Docket No. 080519680-8684-01]
RIN 0648-AW86
Taking and Importing Marine Mammals; U.S. Navy Training in the
Hawaii Range Complex
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Proposed rule; request for comments.
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SUMMARY: NMFS has received a request from the U.S. Navy (Navy) for
authorization to take marine mammals incidental to training activities
conducted within the Hawaii Range Complex (HRC) for the period of
December 2008 through December 2013. Pursuant to the Marine Mammal
Protection Act (MMPA), NMFS is proposing regulations to govern that
take and requesting information, suggestions, and comments on these
proposed regulations.
DATES: Comments and information must be received no later than July 23,
2008.
ADDRESSES: You may submit comments, identified by 0648-AW86, by any one
of the following methods:
Electronic Submissions: Submit all electronic public
comments via the Federal eRulemaking Portal: http://www.regulations.gov.
Hand delivery or mailing of paper, disk, or CD-ROM
comments should be addressed to Michael Payne, Chief, Permits,
Conservation and Education Division, Office of Protected Resources,
National Marine Fisheries Service, 1315 East-West Highway, Silver
Spring, MD 20910-3225.
Instructions: All comments received are a part of the public record
and will generally be posted to http://www.regulations.gov without
change. All Personal Identifying Information (for example, name,
address, etc.) voluntarily submitted by the commenter may be publicly
accessible. Do not submit Confidential Business Information or
otherwise sensitive or protected information.
NMFS will accept anonymous comments. Attachments to electronic
comments will be accepted in Microsoft Word, Excel, WordPerfect, or
Adobe PDF file formats only.
Comments regarding the burden-hour estimates or other aspects of
the collection-of-information requirements contained in this proposed
rule should be submitted in writing to Michael Payne at the address
above and to David Rostker, OMB, by e-mail at [email protected] or by fax to 202-395-7285.
FOR FURTHER INFORMATION CONTACT: Jolie Harrison, Office of Protected
Resources, NMFS, (301) 713-2289, ext. 166.
SUPPLEMENTARY INFORMATION:
Availability
A copy of the Navy's application may be obtained by writing to the
address specified above (See ADDRESSES), telephoning the contact listed
above (see FOR FURTHER INFORMATION CONTACT), or visiting the Internet
at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm. The Navy's
Final Environmental Impact Statement (FEIS) for the Hawaii Range
Complex was published on May 9, 2008, and may be viewed at http://www.govsupport.us/hrc. NMFS participated in the development of the
Navy's FEIS as a cooperating agency under NEPA. Last, NMFS is preparing
a Draft Environmental Assessment (EA) that analyzes the environmental
effects of several different mitigation alternatives for the potential
issuance of the proposed rule. The Draft EA will be posted on the
following Web site as soon as it is complete: http://www.nmfs.noaa.gov/pr/permits/incidental.htm.
Background
Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)
direct 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 specified activity (other than commercial
fishing) during periods of not more than five consecutive years each if
certain findings are made and regulations are issued or, if the taking
is limited to harassment, notice of a proposed authorization is
provided to the public for review.
Authorization shall be granted if NMFS finds that the taking will
have a negligible impact on the species or stock(s), will not have an
unmitigable adverse impact on the availability of the species or
stock(s) for subsistence uses, and if the permissible methods of taking
and requirements pertaining to the mitigation, monitoring and reporting
of such taking are set forth.
NMFS has defined ``negligible impact'' in 50 CFR 216.103 as:
An impact resulting from the specified activity that cannot be
reasonably expected to, and is not reasonably likely to, adversely
affect the species or stock through effects on annual rates of
recruitment or survival.
The National Defense Authorization Act of 2004 (NDAA) (Public Law
108-136) removed the ``small numbers'' and ``specified geographical
region'' limitations and amended the definition of ``harassment'' as it
applies to a ``military readiness activity'' to read as follows
(Section 3(18)(B) of the MMPA):
(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].
Summary of Request
On June 25, 2007, NMFS received an application from the Navy
requesting authorization for the take of 24 species of marine mammals
incidental to upcoming Navy training activities to be conducted within
the HRC, which covers 235,000 nm\2\ around the Main Hawaiian Islands
(see map on page 17 of the application), over the course of 5 years.
These training activities are classified as military readiness
activities. The Navy states that these training activities may
incidentally take marine mammals present within the HRC by exposing
them to sound from mid-frequency or high frequency active sonar (MFAS/
HFAS) or to underwater detonations at levels that NMFS associates with
the take of marine mammals. The Navy requests authorization to take
individuals of 24 species of marine mammals by Level B Harassment.
Further, though they do not anticipate it to occur, the Navy requests
authorization to take, by injury or mortality, up to 10 individuals
each of 10 species over the course of the 5-year period (bottlenose
dolphin, Kogia spp., melon-headed whale, pantropical spotted dolphin,
pygmy killer whale, short-finned pilot whale, striped dolphin, and
Cuvier's, Longman's, and Blainville's beaked whale).
Background of Navy Request
The Navy's mission is to maintain, train, and equip combat-ready
naval forces capable of winning wars, deterring aggression, and
maintaining freedom of the seas. Title 10, U.S. Code (U.S.C.) section
5062 directs the Chief of Naval Operations to train all naval forces
for combat. The Chief of Naval Operations meets that direction, in
part,
[[Page 35511]]
by conducting at-sea training exercises and ensuring naval forces have
access to ranges, operating areas (OPAREAs) and airspace where they can
develop and maintain skills for wartime missions and conduct research,
development, test, and evaluation (RDT&E) of naval weapons systems.
The HRC, where the Navy has, for more than 40 years, routinely
conducted training and major exercises in the waters around the
Hawaiian Islands, is a critical part of the Navy's mission, especially
as it relates to training, for several reasons. Centrally located in
the Pacific Ocean between the west coast of the United States and the
naval stations in the western Pacific, and surrounding the most
isolated islands in the world, the HRC has the infrastructure (i.e.,
extensive existing range assets and training capabilities) to support a
large number of forces in a location both remote and under U.S.
control. The range surrounds the major homeport of Naval Station Pearl
Harbor, enabling re-supply and repairs to submarines and surface ships
alike. The isolation of the range offers an invaluable facility on
which to conduct missile testing and training. Able to link with the
U.S. Army's Pohakuloa Training Area, as well as U.S. Air Force and U.S.
Marine Corps bases where aircraft basing and amphibious training may
occur, the HRC provides a superior joint training environment for all
the U.S. armed services and advanced missile testing capability. Among
the important assets of the HRC is the Pacific Missile Range Facility
(PMRF), which is the world's largest instrumented, multi-environment,
military test range capable of supporting subsurface, surface, air, and
space training, and RDT&E. It consists of instrumented underwater
ranges, controlled airspace, and a temporary operating area covering
2.1 million square nautical miles (nm2) of ocean area. The
Navy must have the flexibility and capacity to quickly surge required
combat power in the event of a national crisis or contingency
operation. Because of its location, training for sustained deployment
at the HRC, rather than at ranges on the west coast, saves 10 transit
days to the western Pacific from the west coast of the United States.
The HRC complex consists of targets and instrumented areas,
airspace, surface OPAREAS, and land range facilities. The Navy's
proposed action includes conducting current and emerging training in
the HRC. Although the Navy plans to conduct many different types of
RDT&E on the land, in the air, and in the water, as well as implement
infrastructure improvements (addressed comprehensively in the Navy's
FEIS), this document specifically analyzes those activities in the HRC
for which the Navy seeks MMPA incidental take authorization, i.e.,
those training activities that the Navy predicts would result in the
generation of levels of sound in the water that NMFS has indicated are
likely to result in the take of marine mammals (not counting SURTASS
LFA sonar, for which the Navy has already obtained an MMPA
authorization), either through the use of sonar (mid-frequency active
sonar (MFAS) or high frequency active sonar (HFAS)) or from the use of
live ordnance, including the detonation of explosives in the water.
Table 1-1 in the Navy's application presents a summary of the training
and RDT&E activities that will occur in the HRC and indicates the
exercise types that the Navy's modeling indicated would likely result
in the take of marine mammals.
Description of the Specified Activities
As mentioned above, the Navy has requested MMPA authorization to
take marine mammals incidental to training activities in the HRC that
would result in the generation of sound in the water, at or above
levels that NMFS has determined will likely result in take (see
Acoustic Take Criteria Section), either through the use of MFAS/HFAS or
the detonation of explosives in the water.
Activities Utilizing Active Tactical Sonar Sources
For this operating area (HRC), the training activities that utilize
active tactical sonar sources fall into the category of Anti-submarine
Warfare (ASW) exercises. This section includes a description of the
active acoustic devices used in ASW exercises, as well as the exercise
types in which these acoustic sources are used.
Acoustic Sources Used for ASW Exercises in the HRC
Tactical military sonars are designed to search for, detect,
localize, classify, and track submarines. There are two types of
sonars, passive and active:
Passive sonars only listen to incoming sounds and, since
they do not emit sound energy in the water, lack the potential to
acoustically affect the environment.
Active sonars generate and emit acoustic energy
specifically for the purpose of obtaining information concerning a
distant object from the received and processed reflected sound energy.
Modern sonar technology includes a multitude of sonar sensor and
processing systems. In concept, the simplest active sonars emit omni-
directional pulses (``pings'') and time the arrival of the reflected
echoes from the target object to determine range. More sophisticated
active sonar emits an omni-directional ping and then rapidly scans a
steered receiving beam to provide directional, as well as range,
information. More advanced sonars transmit multiple preformed beams,
listening to echoes from several directions simultaneously and
providing efficient detection of both direction and range.
The tactical military sonars to be deployed during testing and
training in the HRC are designed to detect submarines in tactical
training scenarios. This task requires the use of the sonar mid-
frequency range (1 kilohertz [kHz] to 10 kHz) predominantly, as well as
one source in the high frequency range (above 10 kHz) that operates at
a level high enough to be considered in the modeling. The high
frequency source will contribute a comparatively very small amount to
the total amount of active sonar that marine mammals will be exposed to
during the Navy's proposed activities, however, for this document we
will refer to the collective high and mid-frequency sonar sources as
MFAS/HFAS. A narrative description of the types of acoustic sources
used in ASW training exercises is included below. Table 1 (below)
summarizes the nominal characteristics of the acoustic sources used in
the modeling to predict take of marine mammals.
[[Page 35512]]
[GRAPHIC] [TIFF OMITTED] TP23JN08.001
Surface Ship Sonars--A variety of surface ships participate in
testing and training events. Some ships (e.g., aircraft carriers,
amphibious assault ships) do not have any onboard active sonar systems,
other than fathometers. Others, like guided missile cruisers, are
equipped with active as well as passive tactical sonars for mine
avoidance and submarine detection and tracking. Within Navy ASW
exercises in the HRC, two types of hull-mounted sonar sources account
for the majority of the estimated impacts to marine mammals. The AN/
SQS-53 hull-mounted sonar, which has a nominal source level of 235
decibels (dB) re 1 [mu]Pa and transmits at center frequencies of 2.6
kHz and 3.3 kHz, is the Navy's most powerful sonar source used in ASW
exercises in the HRC. The AN/SQS-56 hull-mounted sonar has a nominal
source level of 225 dB re 1 [mu]Pa and transmits at a center frequency
of 7.5 kHz. Sonar ping transmission durations were modeled as lasting 1
second per ping and omni-directional, which is a conservative
assumption that may overestimate potential effects. Actual ping
durations will be less than 1 second. Details concerning the tactical
use of specific frequencies and the repetition rate for the sonar pings
is classified but was modeled based on the required tactical training
setting. The AN/SQS-53 and the AN/SQS-56 were modeled using the number
of hours of predicted use (typically at two pings per minute; meaning
an hour of sonar operation results in approximately 120 one-second
pings). Based on modeling results, the Navy anticipates that the
operation of these two sources will likely result in take of marine
mammals (see Estimated Take of Marine Mammals Section).
Hull-mounted sonars occasionally operate in a mode called
``Kingfisher,'' which is designed to better detect smaller objects. The
Kingfisher mode uses the same source level and frequency as normal
search modes, however, it uses a different waveform (designed for small
objects), a shorter pulse length (< 1 sec), a higher pulse repetition
rate (due to the short ranges), and the ping is not omnidirectional,
but directed forward. All Kingfisher use in the HRC (approximately 27
hours/year) was modeled as AN/SQS-53, though the less powerful AN/SQS-
56 likely accounts for part of the total Kingfisher use as well.
Submarine Sonars--Submarine sonars (AN/BQQ-10, AN/BQQ-5, or AN/BSY-
1) are used to detect and target enemy submarines and surface ships.
Because they are trying to avoid being detected, a submarine's use of
MFAS is generally rare, very brief, using minimal power, and may be
narrowly focused. Modeling for the AN/BQQ-10 (all three submarine types
were modeled as AN/BQQ-10, the most powerful submarine sonar source)
assumes sonar use of two pings an hour (which is higher than typical),
for one second each, at 235 dB re 1 [mu]Pa, and using an omni-
directional transmission. The AN/BQQ-10 was modeled using the number of
hours of predicted use (at two pings per hour). Based on modeling
results, the Navy anticipates that the operation of this source may
result in some take of marine mammals (see Estimated Take of Marine
Mammals Section).
Aircraft Sonar Systems--Aircraft sonar systems that would operate
in the HRC include sonobuoys (SSQ-62) and dipping sonar (AN/AQS-22). A
sonobuoy is an expendable device, which may be deployed by maritime
patrol aircraft or helicopters, used for the detection of underwater
acoustic energy and for conducting vertical water column temperature
measurements. Most sonobuoys are passive, but some, like the SSQ-62,
can also generate active acoustic signals. The SSQ-62 has a nominal
source level of 201 dB re 1 [mu]Pa and transmits at a center frequency
of 8 kHz. Dipping sonar is an active or passive sonar device lowered on
cable helicopters to detect or maintain contact with underwater
targets. During ASW training, these systems active modes are only used
briefly for localization of contacts and are not used in primary search
capacity. The AN/AQS-22 has a nominal source level of 217 dB re 1
[mu]Pa and transmits at a center frequency of 4.1 kHz. Based on
modeling results, the Navy anticipates that the operation of these two
sources may result in some take of marine mammals (see Estimated Take
of Marine Mammals Section).
Torpedoes--Torpedoes are the primary ASW weapon used by surface
ships, aircraft, and submarines. The guidance systems of these weapons
can be autonomous (acoustically based) or electronically controlled
from the launching platform through an attached wire. They operate
either passively, exploiting the emitted sound energy by the target, or
actively, ensonifying the target and using the received echoes for
guidance. We know that the MK-48 operates in the high frequency range
(>10 kHZ), however, the nominal source level and the center frequency
are classified. Based on modeling results, the Navy anticipates that
the operation of this source may result in some take of marine mammals
(see Estimated Take of Marine Mammals Section). In addition to the HFA
sonar source used to guide the torpedo, the MK-48 is discussed in the
``Activities Utilizing Underwater Detonations'' Section.
Other Acoustic Sources--The Navy uses other acoustic sources in ASW
exercises. However, based on operational characteristics (such as
frequency and source level), the Navy determined that use of the
following acoustic sources would not likely result in the take of
marine mammals:
Acoustic Device Countermeasures (ADC)--submarine
simulators that make sound to act as decoys to avert localization and/
or torpedo attacks.
Training Targets--ASW training targets consisting of MK-30
and/or MK-39 Expendable Mobile ASW Training
[[Page 35513]]
Target (EMATT) are used to simulate opposition submarines. They are
equipped with one or a combination of the following devices: (1)
Acoustic projectors emanating sounds to simulate submarine acoustic
signatures; (2) echo repeaters to simulate the characteristics of the
echo of a particular sonar signal reflected from a specific type of
submarine; and (3) magnetic sources to trigger magnetic detectors.
Range pingers are active acoustic devices that allow
inwater platforms on the range (e.g., submarines, target simulators,
and exercise torpedoes) to be tracked by hydrophones on the seafloor
such as those at the underwater instrumented range at PMRF. The range
hydrophones are also tied in with transducer nodes that are capable of
transmitting acoustic signals for a limited set of functions, including
submarine warning signals, acoustic commands to submarine target
simulators (acoustic command link), and occasional voice or data
communications (received by participating ships and submarines on
range).
Types of ASW Exercises in the HRC
ASW training conducted within the HRC involves the use of surface
ships, submarines, aircraft, non-explosive and explosive exercise
weapons, and other training-related devices. ASW training involves the
use of active and passive acoustic devices with training activities
occurring in both offshore (<12 nm (22 km) from shore) and open ocean
(>12 nm (22 km) from shore) areas. A description of the different
exercise types is provided below. Table 2 lists the types of ASW
exercises and indicates the areas they are conducted in, the average
duration of an exercise, the average number of exercises/per year, and
the time of year they are conducted. Table 3, at the end of this
section, indicates the total number of hours for each source type
anticipated for each year for each exercise type.
[GRAPHIC] [TIFF OMITTED] TP23JN08.002
Anti-Submarine Warfare Tracking Exercise (ASW TRACKEX)--An ASW
TRACKEX trains aircraft, ship, and submarine crews in tactics,
techniques, and procedures for search, detection, and tracking of
submarines. No torpedoes are fired during a TRACKEX. ASW TRACKEX
includes ships, fixed wing aircraft, helicopters, torpedo targets,
submarines, and weapons recovery boats and/or helicopters. As a unit-
level exercise, an aircraft, ship, or submarine is typically used
versus one target submarine or simulated target. TRACKEXs can include
the use of hull-mounted sonar, submarines, or sonobuoys. No explosive
ordnance is used in TRACKEX exercises.
The target may be non-evading while operating on a specified track
or it may be fully evasive, depending on the state of training of the
ASW unit. Duration of a TRACKEX is highly dependent on the tracking
platform and its available on-station time. A maritime patrol aircraft
can remain on station for eight hours, and typically conducts tracking
exercises that last three to six hours. An ASW helicopter has a much
shorter on-station time, and conducts a typical TRACKEX in one to two
hours. Surface ships and submarines, which measure their on-station
time in days, conduct tracking exercises exceeding eight hours and
averaging up to 18 hours. For modeling purposes, TRACKEX and TORPEX
(explained in next section) sonar hours are averaged, resulting in a
sonar time of 13.5 hours.
ASW TRACKEX events are conducted on ranges within PMRF Warning Area
W-188, the Hawaii Offshore Areas and/or the open ocean. Whenever
aircraft use the ranges for ASW training, range clearance procedures
include a detailed visual range search for marine mammals and
unauthorized boats and planes by the aircraft releasing the inert
torpedoes, range safety boats/aircraft, and range controllers. TRACKEXs
can include the use of hull-mounted sonar, submarines, or sonobuoys,
which can result in the take of marine mammals.
Anti-Submarine Warfare Torpedo Exercises (ASW TORPEX)--Anti-
Submarine Warfare Torpedo Exercises (ASW TORPEX) train crews in
tracking and attack of submerged targets, firing one or more
Recoverable Exercise Torpedoes. TORPEX targets used in the Offshore
Areas include submarines, MK-30 ASW training targets, and MK-39
Expendable Mobile ASW Training Targets. The target may be non-evading
while operating on a specified track, or it may be fully evasive,
depending on the training requirements. Submarines periodically conduct
torpedo firing training exercises within the Hawaii Offshore OPAREA.
Typical duration of a submarine TORPEX event is 22.7 hours, while air
and surface ASW platform TORPEX events are considerably shorter. For
modeling purposes, TRACKEX and TORPEX sonar hours are averaged
resulting in a sonar time of 13.5 hours. TORPEXs can
[[Page 35514]]
include the use of hull-mounted sonar, submarines, sonobuoys, or MK-48
torpedoes (inert), which can result in the take of marine mammals.
Rim of the Pacific (RIMPAC)--RIMPAC is a multi-threat maritime
exercise where submarines, surface ships, and aircraft from the U.S.
and other countries conduct many different exercise events, including
ASW against opposition submarine targets to improve coordination and
interoperability of combined, bilateral and joint forces of
participating nations. RIMPAC occurs during the summer over a 1-month
period every other year (currently in even numbered years). Submarine
targets include real submarines, targets that simulate the operations
of an actual submarine including those described previously under
TORPEX, and virtual submarines interjected into the training events by
exercise controllers. ASW training events are complex and highly
variable. For RIMPAC, the primary event involves a Surface Action Group
(SAG), consisting of one to five surface ships equipped with sonar,
with one or more helicopters, and a P-3 aircraft searching for one or
more submarines. There will be approximately four to eight SAGs for a
typical RIMPAC. For the purposes of analysis, each SAG event is counted
as an ASW training activity. One or more ASW events may occur
simultaneously within the HRC. There will be approximately 44 ASW
training events during a typical RIMPAC, with an average event length
of approximately 12 hours (ranging from 2-24 hours).
In addition to including potential training with of all of the
acoustic sources mentioned previously, RIMPAC includes training events
that involve underwater detonations (described in the next section:
Activities Utilizing Underwater Detonations), including Sinking
Exercise, Air-to-Surface Gunnery Exercise, Surface-to-Surface Gunnery
Exercise, Naval Surface Fire Support, Air-to-Surface Missile Exercise,
Surface-to-Surface Missile Exercise, Bombing Exercise, Mine
Neutralization Exercise, and IEER/EER Exercise. Both the use of the
acoustic sources as well as the underwater detonations could result in
the take of marine mammals. These exercises involving underwater
detonations do not overlap in space and time with sonar exercises.
Explosives from RIMPAC have been included in the training events
described in the next Section.
Undersea Warfare Exercise (USWEX)--Carrier Strike Groups (CSGs) and
Expeditionary Strike Groups (ESGs) that deploy from the west coast of
the United States will experience realistic submarine combat conditions
and assess submarine warfare training capabilities postures in the HRC
prior to their deployment to real world operations elsewhere. As a
combined force, submarines, surface ships, and aircraft will conduct
ASW against opposition submarine targets, which include real
submarines, targets that simulate the operations of an actual
submarine, and virtual submarines interjected into the training events
by exercise controllers. USWEX training events are complex and highly
variable. The primary event involves from one to five surface ships
equipped with sonar, with one or more helicopters, and a P-3 aircraft
searching for one or more submarines. A total of five exercises using
MFAS/HFAS, lasting three to four days each, could occur throughout the
year for USWEX.
In addition to the use of hull-mounted sonar (AN/SQS-53 and AN/SQS-
56), submarine sonar, helicopter dipping sonar, and sonobuoys, USWEX
includes training events that involve underwater detonations as
described in the next section (Activities Utilizing Underwater
Detonations), including Air-to-Surface Gunnery Exercise, Air-to-Surface
Missile Exercise, and Bombing Exercise. Both the use of the acoustic
sources as well as the underwater detonations could result in the take
of marine mammals. These exercises utilizing underwater detonations do
not overlap in space and time with sonar exercises. Explosives from
USWEX have been included in the training events described in the next
section.
Multiple Strike Group Exercise--A Multiple Strike Group Exercise
consists of events that involve Navy assets engaging in a schedule of
events battle scenario, with U.S. forces (blue forces) pitted against a
notional opposition force (red force). Participants use and build upon
previously gained training skill sets to maintain and improve the
proficiency needed for a mission-capable, deployment-ready unit. The
exercise would occur over a 5-day to 10-day period at any time during
the year. As described above for USWEX, as a combined force,
submarines, surface ships, and aircraft will conduct ASW against
opposition submarine targets.
In addition to the use of hull-mounted sonar (AN/SQS-53 and AN/SQS-
56), submarine sonar, helicopter dipping sonar, and sonobuoys , the
Multiple Strike Group Exercise includes training events that involve
underwater detonations as described in the next Section (Activities
Utilizing Underwater Detonations), including Sinking Exercise, Air-to-
Surface Missile Exercise, Mine Neutralization Exercise, and EER/IEER
Exercise. Both the use of the acoustic sources as well as the
underwater detonations could result in the take of marine mammals.
These exercises utilizing underwater detonations do not overlap in
space and time with sonar exercises. Explosives from the Multiple
Strike Group Exercise have been included in the events described in the
next Section.
[[Page 35515]]
[GRAPHIC] [TIFF OMITTED] TP23JN08.003
Activities Utilizing Underwater Detonations
Underwater detonation activities can occur at various depths
depending on the activity (sinking exercise [SINKEX] and mine
neutralization), but may also include activities which may have
detonations at or just below the surface (SINKEX, gunnery exercise
[GUNEX], or missile exercise [MISSILEX]). When the weapons hit the
target except for live torpedo shot, there is no explosion in the
water, and so a ``hit'' is not modeled (i.e., the energy (either
acoustic or pressure) from the hit is not expected to reach levels that
would result in take of marine mammals). When a live weapon misses, it
is modeled as exploding below the water surface at 1 ft (5-inch naval
gunfire, 76mm rounds), 2 meters (Maverick, Harpoon, MK-82, MK-83, MK-
84), or 50-ft (MK-48 torpedo) as shown in Appendix A of the Navy's
application, Table A-7 (the depth is chosen to represent the worst case
of the possible scenarios as related to potential marine mammals
impacts). Exercises may utilize either live or inert ordnance of the
types listed in Table 4. Additionally, successful hit rates are known
to the Navy and are utilized in the effects modeling. Training events
that involve explosives and underwater detonations occur throughout the
year and are described below and summarized in Table 5 at the end of
this section.
[GRAPHIC] [TIFF OMITTED] TP23JN08.004
Sinking Exercise (SINKEX)--In a SINKEX, a specially prepared,
deactivated vessel is deliberately sunk using multiple weapons systems.
The exercise provides training to ship and submarine and aircraft crews
in delivering both live and inert ordnance on a real target. These
target vessels are remediated to standards set by the Environmental
Protection Agency. A SINKEX target is towed to sea and set adrift at
the SINKEX location. The duration of a SINKEX is unpredictable since it
ends when the target sinks, sometimes immediately after the first
weapon impact and sometimes only after multiple impacts by a variety of
weapons. Typically, the exercise lasts for four to eight hours over one
to two days. SINKEXs typically occur only once or twice a year in the
HRC.
[[Page 35516]]
Underwater detonation of several different explosive types could result
in the take of marine mammals. Some or all of the following weapons may
be employed in a SINKEX: Three HARPOON surface-to-surface and air-to-
surface missiles; two to eight air-to-surface Maverick missiles; two to
four MK-82 General Purpose Bombs; two Hellfire air-to-surface missiles;
one SLAM-ER air-to-surface missile; two-hundred and fifty rounds for a
5-inch gun; and one MK-48 heavyweight submarine-launched torpedo.
Surface-to-Surface Gunnery Exercise (S-S GUNEX)--Surface gunnery
exercises (GUNEX) take place in the open ocean to provide gunnery
practice for Navy and Coast Guard ship crews. GUNEX training events
conducted in the Offshore OPAREA involve stationary targets such as a
MK-42 FAST or a MK-58 marker (smoke) buoy. The gun systems employed
against surface targets include the 5-inch, 76 millimeter (mm), 25-mm
chain gun, 20-mm Close-in Weapon System (CIWS), and .50 caliber machine
gun. Typical ordnance expenditure for a single GUNEX is a minimum of 21
rounds of 5-inch or 76-mm ammunition, and approximately 150 rounds of
25-mm or .50-caliber ammunition. Both live and inert training rounds
are used. After impacting the water, the rounds and fragments sink to
the bottom of the ocean. A S-S GUNEX lasts approximately two to four
hours, depending on target services and weather conditions. Detonation
of the live 5-inch and 76-mm rounds could result in the take of marine
mammals.
Naval Surface Fire Support Exercise--Navy surface combatants
conduct fire support exercise (FIREX) training events at PMRF on a
virtual range against ``Fake Island'', located on Barking Sands
Tactical Underwater Range (BARSTUR). Fake Island is unique in that it
is a virtual landmass simulated in three dimensions. Ships conducting
FIREX training against targets on the island are given the coordinates
and elevation of targets. PMRF is capable of tracking fired rounds to
an accuracy of 30 feet (9.1 m). Detonation of the live 5-inch and 76-mm
rounds fired into ocean during this exercise could result in the take
of marine mammals.
Air-to-Surface Missile Exercise (A-S MISSILEX)--The A-S MISSILEX
consists of the attacking platform releasing a forward-fired, guided
weapon at the designated towed target. The exercise involves locating
the target, then designating the target, usually with a laser.
A-S MISSILEX training can take place without the release of a live
weapon if the attacking platform is carrying a captive air training
missile (CATM) simulating the weapon involved in the training. The CATM
MISSILEX is identical to a live-fire exercise in every aspect except
that a weapon is not released, nor does it contain any explosives or
propellant. The event requires a laser-safe range as the target is
designated just as in a live-fire exercise.
From 1 to 16 aircraft, carrying live, inert, or CATMs, or flying
without ordnance (dry runs) are used during the exercise. At sea,
seaborne powered targets (SEPTARs), Improved Surface Towed Targets
(ISTTs), and decommissioned hulks are used as targets. A-S MISSILEX
assets include helicopters and/or one to 16 fixed wing aircraft with
air-to-surface missiles and anti-radiation missiles (electromagnetic
radiation source seeking missiles). When a high-speed anti-radiation
missile (HARM) is used, the exercise is called a HARMEX. Targets
include SEPTARs, ISTTs, and decommissioned ship hulks. Detonation of
live ordnance could result in the take of marine mammals.
Surface-to-Surface Missile Exercise (S-S MISSILEX)--Surface-to-
surface missile exercise (S-S MISSILEX) involves the attack of surface
targets at sea by use of cruise missiles or other missile systems,
usually by a single ship conducting training in the detection,
classification, tracking and engagement of a surface target. Engagement
is usually with Harpoon missiles or Standard missiles in the surface-
to-surface mode. Targets could include virtual targets or the SEPTAR or
ship deployed surface target. S-S MISSILEX training is routinely
conducted on individual ships with embedded training devices. A S-S
MISSILEX could include four to 20 surface-to-surface missiles, SEPTARs,
a weapons recovery boat, and a helicopter for environmental and photo
evaluation. All missiles are equipped with instrumentation packages or
a warhead. Surface-to-air missiles can also be used in a surface-to-
surface mode. S-S MISSILEX activities are conducted within PMRF Warning
area W-188. Each exercise typically lasts five hours, though future S-S
MISSILEXs could range from four to 35 hours. Missile detonation could
result in the take of marine mammals.
Bombing Exercise (BOMBEX)--Fixed-wing aircraft conduct BOMBEX
events against stationary targets (MK-42 FAST or MK-58 smoke buoy) at
sea. An aircraft will clear the area, deploy a smoke buoy or other
floating target, and then set up a racetrack pattern, dropping on the
target with each pass. At PMRF, a range boat might be used to deploy
the target for an aircraft to attack. A BOMBEX may involve either live
or inert ordnance. Underwater detonation of live ordnance could result
in the take of marine mammals.
Mine Neutralization--Mine Neutralization events involve the
detection, identification, evaluation, rendering safe, and disposal of
mines and unexploded ordnance (UXO) that constitutes a threat to ships
or personnel. Mine neutralization training can be conducted by a
variety of air, surface and subsurface assets. Tactics for
neutralization of ground or bottom mines involve a diver placing a
specific amount of explosives, which when detonated underwater at a
specific distance from a mine results in neutralization of the mine.
Floating, or moored, mines involve the diver placing a specific amount
of explosives directly on the mine. Floating mines encountered by Fleet
ships in open ocean areas will be detonated at the surface. Inert dummy
mines are used in the exercises. The total net explosive weight used
against each mine ranges from less than one pound to 20 pounds (0.5 to
9.1 kg). Mine neutralization training takes place offshore in Puuloa
Underwater Range, Lima Landing, Naval Inactive Ship Maintenance
Facility, MCBH, MCTAB, Barters Point Range, Ewa Training Minefield; and
in open-ocean areas. Detonation of live ordnance could result in the
take of marine mammals.
All demolition activities are conducted in accordance with current
Navy directives and approved standard operating procedures. Before any
explosive is detonated, divers are transported a safe distance away
from the explosive. Standard practices for tethered mines in Hawaiian
waters require ground mine explosive charges to be suspended 10 feet
(3.0 m) below the surface of the water.
EER/IEER AN/SSQ-110A--The Extended Echo Ranging and Improved
Extended Echo Ranging (EER/IEER) Systems are air-launched ASW systems
used in conducting ``large area'' searches for submarines. These
systems are made up of airborne avionics ASW acoustic processing and
sonobuoy types that are deployed in pairs. The IEER System's active
sonobuoy component, the AN/SSQ-110A Sonobuoy, would generate a ``ping''
(small detonation) and the passive AN/SSQ-101 ADAR Sonobuoy would
``listen'' for the return echo of the sonar ping that has been bounced
off the surface of a submarine. These sonobuoys are designed to provide
underwater acoustic data necessary for naval aircrews to quickly
[[Page 35517]]
and accurately detect submerged submarines. The expendable and
commandable sonobuoy pairs are dropped from a fixed-wing aircraft into
the ocean in a predetermined pattern (array) with a few buoys covering
a very large area. Upon command from the aircraft, the bottom payload
is released to sink to a designated operating depth. A second command
is required from the aircraft to cause the second payload to release
and detonate generating a ``ping''. There is only one detonation in the
pattern of buoys at a time. Detonation of the buoys could result in the
take of marine mammals.
Air-to-Surface Gunnery Exercise (A-S GUNEX)--Air-to-Surface GUNEX
events are conducted by rotary-wing aircraft against stationary targets
(Floating at-sea Target [FAST] and smoke buoy). Rotary-wing aircraft
involved in this training activity would include a single SH-60 using
either 7.62-mm or .50-caliber door-mounted machine guns. A typical A-S
GUNEX will last approximately one hour and involve the expenditure of
approximately 400 rounds of 50-caliber or 7.62-mm ammunition. Due to
the use of small, inert rounds, A-S GUNEXs are not expected to result
in the take of marine mammals.
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Additional information on the Navy's proposed activities may be
found in the LOA Application and the FEIS (Section 2 and Appendices D,
E, and J).
Description of Marine Mammals in the Area of the Specified Activities
There are 27 marine mammal species with possible or confirmed
occurrence in the HRC. As indicated in Table 6, there are 25 cetacean
species (7 mysticetes and 18 odontocetes) and two pinnipeds. Table 6
also includes the estimated abundance, estimated group size, and
estimated probability of detection (based on Barlow 2006) of the
species that occur in the HRC. Seven marine mammal species listed as
federally endangered under the Endangered Species Act (ESA) occur in
the HRC: the humpback whale, North Pacific right whale, sei whale, fin
whale, blue whale, sperm whale, and Hawaiian monk seal. The most
abundant marine mammals appear to be dwarf sperm whales, striped
dolphins, and Fraser's dolphins. The most abundant large whales are
sperm whales.
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[[Page 35519]]
The Navy has compiled information on the abundance, behavior,
status and distribution, and vocalizations of marine mammal species in
the Hawaiian waters from peer reviewed literature, the Navy Marine
Resource Assessment, NMFS Stock Assessment Reports, and marine mammal
surveys using acoustics or visual observations from aircraft or ships.
This information may be viewed in the Navy's LOA application and/or the
Navy's FEIS for the HRC (see Availability). Additional information is
available in NMFS Stock Assessment Reports, which may be viewed at:
http://www.nmfs.noaa.gov/pr/sars/species.htm.
Based on their rare occurrence in the HRC, the Navy and NMFS do not
anticipate any effects to Blue whales, North Pacific right whales, or
Northern elephant seals and, therefore, they are not addressed further
in this document.
Important Reproductive Areas
Because the consideration of areas where marine mammals are known
to selectively breed or calve are important to both the negligible
impact finding necessary for the issuance of an MMPA authorization and
the need for NMFS to put forth the means of effecting the least
practicable adverse impact paying particular attention to rookeries,
mating grounds, and other areas of similar significance, we are
emphasizing important reproductive areas within this section. Little is
known about the breeding and calving behaviors of many of the marine
mammals that occur in the HRC. Some delphinid species have calving
peaks once or twice a year, but give birth throughout their ranges. The
mysticete species that may occur in the HRC are generally thought to
migrate from higher to lower latitudes to breed and calve in the
winter. With one notable exception, no breeding or calving areas have
been identified in the HRC for the species that occur there. However,
the main Hawaiian Islands constitute one of the world's most important
habitats for the endangered humpback whale. Nearly two-thirds of the
entire North Pacific population of humpback whales migrates to Hawaii
each winter to engage in breeding, calving and nursing activities
important for the survival of their species. The available sighting
information and the known preferred breeding habitat (shallow water)
indicates that humpback whale densities are much higher (up to almost
four whales/square mile) in certain areas and that humpback mothers and
calves are concentrated within the 200-m isobath. The Hawaiian Humpback
Whale National Marine Sanctuary worked with Dr. Joe Mobley to compile a
figure that generally illustrates humpback whale survey data collected
between 1993 and 2003 and indicates areas of high and low density
(Mobley 2004, Figure 1).
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A Brief Background on Sound
An understanding of the basic properties of underwater sound is
necessary to comprehend many of the concepts and analyses presented in
this document. A summary is included below.
Sound is a wave of pressure variations propagating through a medium
(for the sonar considered in this proposed rule, the medium is marine
water). Pressure variations are created by compressing and relaxing the
medium. Sound measurements can be expressed in two forms: intensity and
pressure. Acoustic intensity is the average rate of energy transmitted
through a unit area in a specified direction and is expressed in watts
per square meter (W/m\2\). Acoustic intensity is rarely measured
directly, it is derived from ratios of pressures; the standard
reference pressure for underwater sound is 1 microPascal ([mu]Pa); for
airborne sound, the standard reference pressure is 20 [mu]Pa
(Richardson et al., 1995).
Acousticians have adopted a logarithmic scale for sound
intensities, which is denoted in decibels (dB). Decibel measurements
represent the ratio between a measured pressure value and a reference
pressure value (in this case 1 [mu]Pa or, for airborne sound, 20
[mu]Pa). The logarithmic nature of the scale means that each 10 dB
increase is a ten-fold increase in power (e.g., 20 dB is a 100-fold
increase, 30 dB is a 1,000-fold increase). Humans perceive a 10-dB
increase in noise as a doubling of sound level, or a 10 dB decrease in
noise as a halving of sound level. The term ``sound pressure level''
implies a decibel measure and a reference pressure that is used as the
denominator of the ratio. Throughout this document, NMFS uses 1
microPascal (denoted re: 1 [mu]Pa) as a standard reference pressure
unless noted otherwise.
It is important to note that decibels underwater and decibels in
air are not the same and cannot be directly compared. To estimate a
comparison between sound in air and underwater, because of the
different densities of air and water and the different decibel
standards (i.e., reference pressures) in water and air, a sound with
the same intensity (i.e., power) in air and in water would be
approximately 63 dB quieter in air. Thus a sound that is 160 dB loud
underwater would have the same approximate effective intensity as a
sound that is 97 dB loud in air.
Sound frequency is measured in cycles per second, or Hertz
(abbreviated Hz), and is analogous to musical pitch; high-pitched
sounds contain high frequencies and low-pitched sounds contain low
frequencies. Natural sounds in the ocean span a huge range of
frequencies: from earthquake noise at 5 Hz to harbor porpoise clicks at
150,000 Hz (150 kHz). These sounds are so low or so high in pitch that
humans cannot even hear them; acousticians call these infrasonic and
ultrasonic sounds, respectively. A single sound may be made up of many
different frequencies together. Sounds made up of only a small range of
frequencies are called ``narrowband'', and sounds with a broad range of
frequencies are called ``broadband''; airguns are an example of a
broadband sound source and tactical sonars are an example of a
narrowband sound source.
When considering the influence of various kinds of sound on the
marine environment, it is necessary to understand that different kinds
of marine life are sensitive to different frequencies of sound. Based
on available behavioral data, audiograms derived using auditory evoked
potential, anatomical modeling, and other data, Southall et al. (2007)
designate ``functional hearing groups'' and estimate the lower and
upper frequencies of functional hearing of the groups. Further, the
frequency range in which each group's hearing is estimated as being
most sensitive is represented in the flat part of the M-weighting
functions developed for each group. More specific data is available for
certain species (Table 17). The functional groups and the associated
frequencies are indicated below:
Low frequency cetaceans (13 species of mysticetes):
Functional hearing is estimated to occur between approximately 7 Hz and
22 kHz.
Mid-frequency cetaceans (32 species of dolphins, six
species of larger toothed whales, and 19 species of beaked and
bottlenose whales): Functional hearing is estimated to occur between
approximately 150 Hz and 160 kHz.
High frequency cetaceans (eight species of true porpoises,
six species of river dolphins, Kogia, the franciscana, and four species
of cephalorhynchids): Functional hearing is estimated to occur between
approximately 200 Hz and 180 kHz.
Pinnipeds in Water: Functional hearing is estimated to
occur between approximately 75 Hz and 75 kHz, with the greatest
sensitivity between approximately 700 Hz and 20 kHz.
Pinnipeds in Air: Functional hearing is estimated to occur
between approximately 75 Hz and 30 kHz.
Because ears adapted to function underwater are physiologically
different from human ears, comparisons using decibel measurements in
air would still not be adequate to describe the effects of a sound on a
whale. When sound travels away from its source, its loudness decreases
as the distance traveled (propagates) by the sound increases. Thus, the
loudness of a sound at its source is higher than the loudness of that
same sound a kilometer distant. Acousticians often refer to the
loudness of a sound at its source (typically measured one meter from
the source) as the source level and the loudness of sound elsewhere as
the received level. For example, a humpback whale three kilometers from
an airgun that has a source level of 230 dB may only be exposed to
sound that is 160 dB loud, depending on how the sound propagates. As a
result, it is important not to confuse source levels and received
levels when discussing the loudness of sound in the ocean.
As sound travels from a source, its propagation in water is
influenced by various physical characteristics, including water
temperature, depth, salinity, and surface and bottom properties that
cause refraction, reflection, absorption, and scattering of sound
waves. Oceans are not homogeneous and the contribution of each of these
individual factors is extremely complex and interrelated. The physical
characteristics that determine the sound's speed through the water will
change with depth, season, geographic location, and with time of day
(as a result, in actual sonar operations, crews will measure oceanic
conditions, such as sea water temperature and depth, to calibrate
models that determine the path the sonar signal will take as it travels
through the ocean and how strong the sound signal will be at a given
range along a particular transmission path). As sound travels through
the ocean, the intensity associated with the wavefront diminishes, or
attenuates. This decrease in intensity is referred to as propagation
loss, also commonly called transmission loss.
Metrics Used in This Document
This section includes a brief explanation of the two sound
measurements (sound pressure level (SPL) and sound exposure level
(SEL)) frequently used in the discussions of acoustic effects in this
document.
SPL
Sound pressure is the sound force per unit area, and is usually
measured in micropascals ([mu]Pa), where 1 Pa is the pressure resulting
from a force of one newton exerted over an area of one
[[Page 35522]]
square meter. SPL is expressed as the ratio of a measured sound
pressure and a reference level. The commonly used reference pressure
level in underwater acoustics is 1 [mu]Pa, and the units for SPLs are
dB re: 1 [mu]Pa.
SPL (in dB) = 20 log (pressure/reference pressure)
SPL is an instantaneous measurement and can be expressed as the
peak, the peak-peak, or the root mean square (rms). Root mean square,
which is the square root of the arithmetic average of the squared
instantaneous pressure values, is typically used in discussions of the
effects of sounds on vertebrates and all references to SPL in this
document refer to the root mean square. SPL does not take the duration
of a sound into account. SPL is the applicable metric used in the risk
continuum, which is used to estimate behavioral harassment takes (see
Level B Harassment Risk Function (Behavioral Harassment) Section).
SEL
SEL is an energy metric that integrates the squared instantaneous
sound pressure over a stated time interval. The units for SEL are dB
re: 1 [mu]Pa\2\s.
SEL = SPL + 10log(duration in seconds)
As applied to tactical sonar, the SEL includes both the SPL of a
sonar ping and the total duration. Longer duration pings and/or pings
with higher SPLs will have a higher SEL. If an animal is exposed to
multiple pings, the SEL in each individual ping is summed to calculate
the total SEL. The total SEL depends on the SPL, duration, and number
of pings received. The thresholds that NMFS uses to indicate at what
received level the onset of temporary threshold shift (TTS) and
permanent threshold shift (PTS) in hearing are likely to occur are
expressed in SEL.
Potential Effects of Specified Activities on Marine Mammals
Exposure to MFAS/HFAS
The Navy has requested authorization for the take of marine mammals
that may occur incidental to training activities in the HRC utilizing
MFAS/HFAS or underwater explosives. The Navy has analyzed other Navy
activities in the HRC, both ongoing and proposed, and in consultation
with NMFS as a cooperating agency for the HRC EIS, has determined that
take of marine mammals incidental to other Navy activities is unlikely
and, therefore, has not requested authorization for take of marine
mammals that might occur incidental to any other activities. Therefore,
NMFS will analyze the potential effects on marine mammals from MFAS/
HFAS and underwater detonations, but not from other activities.
For the purposes of MMPA authorizations, NMFS's effects assessments
have three primary purposes: (1) To put forth the permissible methods
of taking within the context of MMPA Level B Harassment (behavioral
harassment), Level A Harassment (injury), and mortality (i.e., identify
the number and types of take that will occur); (2) to determine whether
the specified activity will have a negligible impact on the affected
species or stocks of marine mammals (based on the likelihood that the
activity will adversely affect the species or stock through effects on
annual rates of recruitment or survival); and (3) to determine whether
the specified activity will have an unmitigable adverse impact on the
availability of the species or stock(s) for subsistence uses (however,
there are no subsistence communities that would be affected in the HRC,
so this determination is inapplicable for the HRC).
More specifically, for activities involving active tactical sonar
or underwater detonations, NMFS's analysis will identify the
probability of lethal responses, physical trauma, sensory impairment
(permanent and temporary threshold shifts and acoustic masking),
physiological responses (particular stress responses), behavioral
disturbance (that rises to the level of harassment), and social
responses that would be classified as behavioral harassment or injury
and/or would be likely to adversely affect the species or stock through
effects on annual rates of recruitment or survival. In this section, we
will focus qualitatively on the different ways that MFAS/HFAS and
underwater explosive detonations may affect marine mammals (some of
which NMFS would not classify as harassment). Then, in the Estimated
Take of Marine Mammals Section, NMFS will relate the potential effects
to marine mammals from MFAS/HFAS and underwater detonation of
explosives to the MMPA regulatory definitions of Level A and Level B
Harassment and attempt to quantify those effects.
In its April 14, 2008, Biological Opinion of the U.S. Navy's
proposal to conduct four training exercises in the Cherry Point,
Virginia Capes, and Jacksonville, Range Complexes NMFS presented a
conceptual model of the potential responses of endangered and
threatened species upon being exposed to active sonar and the pathways
by which those responses might affect the fitness of individual animals
that have been exposed, which may then affect the reproduction and/or
survival of those individuals. Literature supporting the framework,
with examples drawn from many taxa (both aquatic and terrestrial) was
included in the ``Application of this Approach'' and ``Response
Analyses'' sections of that document (available at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm). This conceptual framework
may also be used to describe the responses and pathways for non-
endangered and non-threatened species and is included in this document
for reference (Figure 2).
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Direct Physiological Effects
Based on the literature, there are two basic ways that MFAS/HFAS
might directly result in physical trauma or damage: Noise-induced loss
of hearing sensitivity (more commonly-called ``threshold shift'') and
acoustically mediated bubble growth. Separately, an animal's behavioral
reaction to an acoustic exposure might lead to physiological effects
that might ultimately lead to injury or death, which is discussed later
in the Stranding section.
Threshold Shift (Noise-Induced Loss of Hearing)
When animals exhibit reduced hearing sensitivity (i.e., sounds must
be louder for an animal to recognize them) following exposure to a
sufficiently intense sound, it is referred to as a noise-induced
threshold shift (TS). An animal can experience temporary threshold
shift (TTS) or permanent threshold shift (PTS). TTS can last from
minutes or hours to days (i.e., there is recovery), occurs in specific
frequency ranges (i.e., an animal might only have a temporary loss of
hearing sensitivity between the frequencies of 1 and 10 kHz)), and can
be of varying amounts (for example, an animal's hearing sensitivity
might be reduced by only 6 dB or reduced by 30 dB). PTS is permanent
(i.e., there is no recovery), but also occurs in a specific frequency
range and amount as mentioned.
The following physiological mechanisms are thought to play a role
in inducing auditory TSs: Effects to sensory hair cells in the inner
ear that reduce their sensitivity, modification of the chemical
environment within the sensory cells, residual muscular activity in the
middle ear, displacement of certain inner ear membranes, increased
blood flow, and post-stimulatory reduction in both efferent and sensory
neural output (Southall et al., 2007). The amplitude, duration,
frequency, temporal pattern, and energy distribution of sound exposure
all affect the amount of associated TS and the frequency range in which
it occurs. As amplitude and duration of sound exposure increase, so,
generally, does the amount of TS. For continuous sounds, exposures of
equal energy (the same SEL) will lead to approximately equal effects.
For intermittent sounds, less TS will occur than from a continuous
exposure with the same energy (some recovery will occur between
exposures) (Kryter et al., 1966; Ward, 1997). For example, one short
but loud (higher SPL) sound exposure may induce the same impairment as
one longer but softer sound, which in turn may cause more impairment
than a series of several intermittent softer sounds with the same total
energy (Ward, 1997). Additionally, though TTS is temporary, very
prolonged exposure to sound strong enough to elicit TTS, or shorter-
term exposure to sound levels well above the TTS threshold, can cause
PTS, at least in terrestrial mammals (Kryter, 1985) (although in the
case of MFAS/HFAS, animals are not expected to be exposed to levels
high enough or durations long enough to result in PTS).
PTS is considered auditory injury (Southall et al., 2007).
Irreparable damage to the inner or outer cochlear hair cells may cause
PTS, however, other mechanisms are also involved, such as exceeding the
elastic limits of certain tissues and membranes in the middle and inner
ears and resultant changes in the chemical composition of the inner ear
fluids (Southall et al., 2007).
Although the published body of scientific literature contains
numerous theoretical studies and discussion papers on hearing
impairments that can occur with exposure to a loud sound, only a few
studies provide empirical information on the levels at which noise-
induced loss in hearing sensitivity occurs in nonhuman animals. For
cetaceans, published data are limited to the captive bottlenose dolphin
and beluga (Finneran et al., 2000, 2002b, 2005a; Schlundt et al., 2000;
Nachtigall et al., 2003, 2004). For pinnipeds in water, data is limited
to Kastak et al.'s measurement of TTS in one harbor seal, one elephant
seal, and one California sea lion.
Marine mammal hearing plays a critical role in communication with
conspecifics, and interpreting environmental cues for purposes such as
predator avoidance and prey capture. Depending on the degree (dB),
duration, and frequency range of TTS, and the context in which it is
experienced, TTS can have effects on marine mammals ranging from
discountable to serious (similar to those discussed in auditory
masking, below). For example, a marine mammal may be able to readily
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal
is traveling through the open ocean, where ambient noise is lower and
there are not as many competing sounds present. Alternatively, a larger
amount and longer duration of TTS sustained during time when
communication is critical for successful mother/calf interactions could
have more serious impacts. Also, depending on the degree and frequency
range, the effects of PTS on an animal could range in severity,
although it is considered generally more serious because it is a long
term condition. Of note, reduced hearing sensitivity as a simple
function of development and aging has been observed in marine mammals,
as well as humans and other taxa (Southall et al., 2007), so we can
infer that strategies exist for coping with this condition to some
degree, though likely not without cost. There is no empirical evidence
that exposure to MFAS/HFAS can cause PTS in any marine mammals; instead
the probability of PTS has been inferred from studies of TTS (see
Richardson et al. 1995).
Acoustically Mediated Bubble Growth
One theoretical cause of injury to marine mammals is rectified
diffusion (Crum and Mao, 1996), the process of increasing the size of a
bubble by exposing it to a sound field. This process could be
facilitated if the environment in which the ensonified bubbles exist is
supersaturated with gas. Repetitive diving by marine mammals can cause
the blood and some tissues to accumulate gas to a greater degree than
is supported by the surrounding environmental pressure (Ridgway and
Howard, 1979). The deeper and longer dives of some marine mammals (for
example, beaked whales) are theoretically predicted to induce greater
supersaturation (Houser et al., 2001b). If rectified diffusion were
possible in marine mammals exposed to high-level sound, conditions of
tissue supersaturation could theoretically speed the rate and increase
the size of bubble growth. Subsequent effects due to tissue trauma and
emboli would presumably mirror those observed in humans suffering from
decompression sickness.
It is unlikely that the short duration of sonar pings would be long
enough to drive bubble growth to any substantial size, if such a
phenomenon occurs. Recent work conducted by Crum et al. (2005)
demonstrated the possibility of rectified diffusion for short duration
signals, but at sound exposure levels and tissue saturations levels
that are improbable to occur in a diving marine mammal. However, an
alternative but related hypothesis has also been suggested: Stable
bubbles could be destabilized by high-level sound exposures such that
bubble growth then occurs through static diffusion of gas out of the
tissues. In such a scenario the marine mammal would need to be in a
gas-supersaturated state for a long enough period of time for bubbles
to become of a problematic size. Yet
[[Page 35525]]
another hypothesis (decompression sickness) has speculated that rapid
ascent to the surface following exposure to a startling sound might
produce tissue gas saturation sufficient for the evolution of nitrogen
bubbles (Jepson et al., 2003; Fernandez et al., 2005). In this
scenario, the rate of ascent would need to be sufficiently rapid to
compromise behavioral or physiological protections against nitrogen
bubble formation. Collectively, these hypotheses can be referred to as
``hypotheses of acoustically mediated bubble growth.''
Although theoretical predictions suggest the possibility for
acoustically mediated bubble growth, there is considerable disagreement
among scientists as to its likelihood (Piantadosi and Thalmann, 2004;
Evans and Miller, 2003). Crum and Mao (1996) hypothesized that received
levels would have to exceed 190 dB in order for there to be the
possibility of significant bubble growth due to supersaturation of
gases in the blood (i.e., rectified diffusion). More recent work
conducted by Crum et al. (2005) demonstrated the possibility of
rectified diffusion for short duration signals, but at SELs and tissue
saturation levels that are highly improbable to occur in diving marine
mammals. To date, Energy Levels (ELs) predicted to cause in vivo bubble
formation within diving cetaceans have not been evaluated (NOAA,
2002b). Although it has been argued that traumas from some recent
beaked whale strandings are consistent with gas emboli and bubble-
induced tissue separations (Jepson et al., 2003), there is no
conclusive evidence of this. However, Jepson et al. (2003, 2005) and
Fernandez et al. (2004, 2005) concluded that in vivo bubble formation,
which may be exacerbated by deep, long-duration, repetitive dives may
explain why beaked whales appear to be particularly vulnerable to sonar
exposures. Further investigation is needed to further assess the
potential validity of these hypotheses. More information regarding
hypotheses that attempt to explain how behavioral responses to MFAS/
HFAS can lead to strandings is included in the Behaviorally Mediated
Bubble Growth Section, after the summary of strandings.
Acoustic Masking
Marine mammals use acoustic signals for a variety of purposes,
which differ among species, but include communication between
individuals, navigation, foraging, reproduction, and learning about
their environment (Erbe and Farmer, 2000; Tyack, 2000). Masking, or
auditory interference, generally occurs when sounds in the environment
are louder than and of a similar frequency to, auditory signals an
animal is trying to receive. Masking is a phenomenon that affects
animals that are trying to receive acoustic information about their
environment, including sounds from other members of their species,
predators, prey, and sounds that allow them to orient in their
environment. Masking these acoustic signals can disturb the behavior of
individual animals, groups of animals, or entire populations.
The extent of the masking interference depends on the spectral,
temporal, and spatial relationships between the signals an animal is
trying to receive and the masking noise, in addition to other factors.
In humans, significant masking of tonal signals occurs as a result of
exposure to noise in a narrow band of similar frequencies. As the sound
level increases, though, the detection of frequencies above those of
the masking stimulus decreases also. This principle is expected to
apply to marine mammals as well because of common biomechanical
cochlear properties across taxa.
Richardson et al. (1995b) argued that the maximum radius of
influence of an industrial noise (including broadband low frequency
sound transmission) on a marine mammal is the distance from the source
to the point at which the noise can barely be heard. This range is
determined by either the hearing sensitivity of the animal or the
background noise level present. Industrial masking is most likely to
affect some species' ability to detect communication calls and natural
sounds (i.e., surf noise, prey noise, etc.; Richardson et al., 1995).
The echolocation calls of toothed whales are subject to masking by
high frequency sound. Human data indicate low frequency sound can mask
high frequency sounds (i.e., upward masking). Studies on captive
odontocetes by Au et al. (1974, 1985, 1993) indicate that some species
may use various processes to reduce masking effects (e.g., adjustments
in echolocation call intensity or frequency as a function of background
noise conditions). There is also evidence that the directional hearing
abilities of odontocetes are useful in reducing masking at the high
frequencies these cetaceans use to echolocate, but not at the low-to-
moderate frequencies they use to communication (Zaitseva et al., 1980).
As mentioned previously, the functional hearing ranges of
mysticetes, odontocetes, and pinnipeds all encompass the frequencies of
the sonar sources used in the Navy's training exercises. Additionally,
almost all species vocal repertoires span across the frequencies of the
sonar sources used by the Navy. The closer the characteristics of the
masking signal to the signal of interest, the more likely masking is to
occur. However, due to the pulse length and duty cycle of the MFAS/HFAS
signal, masking is unlikely to occur as a result of exposure to MFAS/
HFAS during the training exercises in the HRC.
Impaired Communication
In addition to making it more difficult for animals to perceive
acoustic cues in their environment, anthropogenic sound presents
separate challenges for animals that are vocalizing. When they
vocalize, animals are aware of environmental conditions that affect the
``active space'' of their vocalizations, which is the maximum area
within which their vocalizations can be detected before it drops to the
level of ambient noise (Brenowitz, 2004; Brumm et al., 2004; Lohr et
al., 2003). Animals are also aware of environmental conditions that
affect whether listeners can discriminate and recognize their
vocalizations from other sounds, which are more important than
detecting a vocalization (Brenowitz, 1982; Brumm et al., 2004; Dooling,
2004; Marten and Marler, 1977; Patricelli et al., 2006). Most animals
that vocalize have evolved with an ability to make vocal adjustments to
their vocalizations to increase the signal-to-noise ratio, active
space, and recognizability of their vocalizations in the face of
temporary changes in background noise (Brumm et al., 2004; Patricelli
et al., 2006). Vocalizing animals will make one or more of the
following adjustments to their vocalizations: Adjust the frequency
structure; Adjust the amplitude; Adjust temporal structure; or Adjust
temporal delivery (see Biological Opinion).
Many animals will combine several of these strategies to compensate
for high levels of background noise. Anthropogenic sounds that reduce
the signal-to-noise ratio of animal vocalizations, increase the masked
auditory thresholds of animals listening for such vocalizations, or
reduce the active space of an animal's vocalizations impair
communication between animals. Most animals that vocalize have evolved
strategies to compensate for the effects of short-term or temporary
increases in background or ambient noise on their songs or calls.
Although the fitness consequences of these vocal adjustments remain
unknown, like most other trade-offs animals must make, some of these
strategies probably come at a cost (Patricelli et al., 2006). For
[[Page 35526]]
example, vocalizing more loudly in noisy environments may have
energetic costs that decrease the net benefits of vocal adjustment and
alter a bird's energy budget (Brumm, 2004; Wood and Yezerinac, 2006).
Shifting songs and calls to higher frequencies may also impose
energetic costs (Lambrechts, 1996).
Stress Responses
Classic stress responses begin when an animal's central nervous
system perceives a potential threat to its homeostasis. That perception
triggers stress responses regardless of whether a stimulus actually
threatens the animal; the mere perception of a threat is sufficient to
trigger a stress response (Moberg, 2000; Sapolsky et al., 2005; Seyle,
1950). Once an animal's central nervous system perceives a threat, it
mounts a biological response or defense that consists of a combination
of the four general biological defense responses: behavioral responses,
autonomic nervous system responses, neuroendocrine responses, or immune
response.
In the case of many stressors, an animal's first and most
economical (in terms of biotic costs) response is behavioral avoidance
of the potential stressor or avoidance of continued exposure to a
stressor. An animal's second line of defense to stressors involves the
autonomic nervous system and the classical ``fight or flight'' response
which includes the cardiovascular system, the gastrointestinal system,
the exocrine glands, and the adrenal medulla to produce changes in
heart rate, blood pressure, and gastrointestinal activity that humans
commonly associate with ``stress.'' These responses have a relatively
short duration and may or may not have significant long-term effect on
an animal's welfare.
An animal's third line of defense to stressors involves its
neuroendocrine or sympathetic nervous systems; the system that has
received the most study has been the hypothalmus-pituitary-adrenal
system (also known as the HPA axis in mammals or the hypothalamus-
pituitary-interrenal axis in fish and some reptiles). Unlike stress
responses associated with the autonomic nervous system, virtually all
neuro-endocrine functions that are affected by stress--including immune
competence, reproduction, metabolism, and behavior--are regulated by
pituitary hormones. Stress-induced changes in the secretion of
pituitary hormones have been implicated in failed reproduction (Moberg,
1987; Rivier, 1995) and altered metabolism (Elasser et al., 2000),
reduced immune competence (Blecha, 2000) and behavioral disturbance.
Increases in the circulation of glucocorticosteroids (cortisol,
corticosterone, and aldosterone in marine mammals; see Romano et al.,
2004) have been equated with stress for many years.
The primary distinction between stress (which is adaptive and does
not normally place an animal at risk) and distress is the biotic cost
of the response. During a stress response, an animal uses glycogen
stores that can be quickly replenished once the stress is alleviated.
In such circumstances, the cost of the stress response would not pose a
risk to the animal's welfare. However, when an animal does not have
sufficient energy reserves to satisfy the energetic costs of a stress
response, energy resources must be diverted from other biotic function,
which impairs those functions that experience the diversion. For
example, when mounting a stress response diverts energy away from
growth in young animals, those animals may experience stunted growth.
When mounting a stress response diverts energy from a fetus, an
animal's reproductive success and its fitness will suffer. In these
cases, the animals will have entered a pre-pathological or pathological
state which is called ``distress'' (sensu Seyle 1950) or ``allostatic
loading'' (sensu McEwen and Wingfield, 2003). This pathological state
will last until the animal replenishes its biotic reserves sufficient
to restore normal function.
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses have also been documented
fairly well through controlled experiment; because this physiology
exists in every vertebrate that has been studied, it is not surprising
that stress responses and their costs have been documented in both
laboratory and free-living animals (for examples see, Holberton et al.,
1996; Hood et al., 1998; Jessop et al., 2003; Krausman et al., 2004;
Lankford et al., 2005; Reneerkens et al., 2002; Thompson and Hamer,
2000). Although no information has been collected on the physiological
responses of marine mammals to exposure to anthropogenic sounds,
studies of other marine animals and terrestrial animals would lead us
to expect some marine mammals to experience physiological stress
responses and, perhaps, physiological responses that would be
classified as ``distress'' upon exposure to mid-frequency and low-
frequency sounds.
For example, Jansen (1998) reported on the relationship between
acoustic exposures and physiological responses that are indicative of
stress responses in humans (for example, elevated respiration and
increased heart rates). Jones (1998) reported on reductions in human
performance when faced with acute, repetitive exposures to acoustic
disturbance. Trimper et al. (1998) reported on the physiological stress
responses of osprey to low-level aircraft noise while Krausman et al.
(2004) reported on the auditory and physiology stress responses of
endangered Sonoran pronghorn to military overflights. Smith et al.
(2004a, 2004b) identified noise-induced physiological transient stress
responses in hearing-specialist fish that accompanied short- and long-
term hearing losses. Welch and Welch (1970) reported physiological and
behavioral stress responses that accompanied damage to the inner ears
of fish and several mammals.
Hearing is one of the primary senses cetaceans use to gather
information about their environment and to communicate with
conspecifics. Although empirical information on the relationship
between sensory impairment (TTS, PTS, and acoustic masking) on
cetaceans remains limited, it seems reasonable to assume that reducing
an animal's ability to gather information about its environment and to
communicate with other members of its species would be stressful for
animals that use hearing as their primary sensory mechanism. Therefore,
we assume that acoustic exposures sufficient to trigger onset PTS or
TTS would be accompanied by physiological stress responses because
terrestrial animals exhibit those responses under similar conditions
(NRC, 2003). More importantly, marine mammals might experience stress
responses at received levels lower than those necessary to trigger
onset TTS. Based on empirical studies of the time required to recover
from stress responses (Moberg, 2000), we also assume that stress
responses are likely to persist beyond the time interval required for
animals to recover from TTS and might result in pathological and pre-
pathological states that would be as significant as behavioral
responses to TTS.
Behavioral Disturbance
Behavioral responses to sound are highly variable and context-
specific. Exposure of marine mammals to sound sources can result in
(but is not limited to) the following observable responses: Increased
alertness; orientation or attraction to a sound source; vocal
modifications; cessation of feeding; cessation of social interaction;
alteration of movement or diving behavior; habitat
[[Page 35527]]
abandonment (temporary or permanent); and, in severe cases, panic,
flight, stampede, or stranding, potentially resulting in death
(Southall et al., 2007).
Many different variables can influence an animals perception of and
response to (nature and magnitude) an acoustic event. An animals prior
experience with a sound type effects whether it is less likely
(habituation) or more likely (sensitization) to respond to certain
sounds in the future (animals can also be innately pre-disposed to
respond to certain sounds in certain ways) (Southall et al., 2007).
Related to the sound itself, the perceived nearness of the sound,
bearing of the sound (approaching vs. retreating), similarity of a
sound to biologically relevant sounds in the animal's environment
(i.e., calls of predators, prey, or conspecifics), and familiarity of
the sound may effect the way an animal responds to the sound (Southall
et al., 2007). Individuals (of different age, gender, reproductive
status, etc.) among most populations will have variable hearing
capabilities, and differing behavioral sensitivities to sounds that
will be affected by prior conditioning, experience, and current
activities of those individuals. Often, specific acoustic features of
the sound and contextual variables (i.e., proximity, duration, or
recurrence of the sound or the current behavior that the marine mammal
is engaged in or its prior experience), as well as entirely separate
factors such as the physical presence of a nearby vessel, may be more
relevant to the animal's response than the received level alone.
There are few empirical studies of avoidance responses of free-
living cetaceans to mid-frequency sonars. Much more information is
available on the avoidance responses of free-living cetaceans to other
acoustic sources, like seismic airguns and low frequency sonar, than
mid-frequency active sonar. Richardson et al., (1995) noted that
avoidance reactions are the most obvious manifestations of disturbance
in marine mammals.
Behavioral Responses (Southall et al. (2007))
Southall et al., (2007) reports the results of the efforts of a
panel of experts in acoustic research from behavioral, physiological,
and physical disciplines that convened and reviewed the available
literature on marine mammal hearing and physiological and behavioral
responses to man-made sound with the goal of proposing exposure
criteria for certain effects. This compilation of literature is very
valuable, though Southall et al. note that not all data is equal, some
have poor statistical power, insufficient controls, and/or limited
information on received levels, background noise, and other potentially
important contextual variables--such data were reviewed and sometimes
used for qualitative illustration, but were not included in the
quantitative analysis for the criteria recommendations.
In the Southall et al., (2007) report, for the purposes of
analyzing responses of marine mammals to anthropogenic sound and
developing critieria, the authors differentiate between single pulse
sounds, multiple pulse sounds, and non-pulse sounds. MFAS/HFAS sonar is
considered a non-pulse sound. Southall et al., (2007) summarize the
reports associated with low and mid-frequency cetacean and pinniped
responses to non-pulse sounds (there are no high frequency cetaceans in
Hawaii) in Appendix C of their report (incorporated by reference and
summarized in the three paragraphs below).
The reports that address responses of low frequency cetaceans to
non-pulse sounds include data gathered in the field and related to
several types of sound sources (of varying similarity to MFAS/HFAS)
including: Vessel noise, drilling and machinery playback, low frequency
M-sequences (sine wave with multiple phase reversals) playback, low
frequency active sonar playback, drill ships, Acoustic Thermometry of
Ocean Climate (ATOC) source, and non-pulse playbacks. These reports
generally indicate no (or very limited) responses to received levels in
the 90 to 120 dB re: 1 Pa range and an increasing likelihood of
avoidance and other behavioral effects in the 120 to 160 dB range. As
mentioned earlier, though, contextual variables play a very important
role in the reported responses and the severity of effects are not
linear when compared to received level. Also, though, few of the
laboratory or field datasets had common conditions, behavioral contexts
or sound sources, so it is not surprising that responses differ.
The reports that address responses of mid-frequency cetaceans to
non-pulse sounds include data gathered both in the field and the
laboratory and related to several different sound sources (of varying
similarity to MFAS/HFAS) including: Pingers, drilling playbacks, ship
and ice-breaking noise, vessel noise, Acoustic Harassment Devices
(AHDs), Acoustic Deterrent Devices (ADDs), MFAS, and non-pulse bands
and tones. Southall et al. were unable to come to a clear conclusion
regarding these reports. In some cases, animals in the field showed
significant responses to received levels between 90 and 120 dB, while
in other cases these responses were not seen in the 120 to 150 dB
range. The disparity in results was likely due to contextual variation
and the differences between the results in the field and laboratory
data (animals responded at lower levels in the field).
The reports that address the responses of pinnipeds in water to
non-pulse sounds include data gathered both in the field and the
laboratory and related to several different sound sources (of varying
similarity to MFAS/HFAS) including: AHDs, ATOC, various non-pulse
sounds used in underwater data communication; underwater drilling, and
construction noise. Few studies exist with enough information to
include them in the analysis. The limited data suggested that exposures
to non-pulse sounds between 90 and 140 dB generally do not result in
strong behavioral responses in pinnipeds in water and no data exist at
higher received levels.
In addition to summarizing the available data, the authors of
Southall et al. (2007) developed a severity scaling system with the
intent of ultimately being able to assign some level of biological
significance to a response. Following is a summary of their scoring
system, a comprehensive list of the behaviors associated with each
score may be found in the report:
0-3 (Minor and/or brief behaviors) includes, but is not
limited to: No response; minor changes in speed or locomotion (but with
no avoidance); individual alert behavior; minor cessation in vocal
behavior; minor changes in response to trained behaviors (in
laboratory).
4-6 (Behaviors with higher potential to affect foraging,
reproduction, or survival) includes, but is not limited to: Moderate
changes in speed, direction, or dive profile; brief shift in group
distribution; prolonged cessation or modification of vocal behavior
(duration > duration of sound), minor or moderate individual and/or
group avoidance of sound; brief cessation of reproductive behavior; or
refusal to initiate trained tasks (in laboratory).
7-9 (Behaviors considered likely to affect the
aforementioned vital rates) includes, but is not limited to: Extensive
of prolonged aggressive behavior; moderate, prolonged or significant
separation of females and dependent offspring with disruption of
acoustic reunion mechanisms; long-term avoidance of an area; outright
panic, stampede, stranding; threatening or attacking sound source (in
laboratory).
[[Page 35528]]
In Table 7 we have summarized the scores that Southall et al.
(2007) assigned to the papers that reported behavioral responses of
low-frequency cetaceans, mid-frequency cetaceans, and pinnipeds in
water to non-pulse sounds.
[GRAPHIC] [TIFF OMITTED] TP23JN08.009
Potential Effects of Behavioral Disturbance
The different ways that marine mammals respond to sound are
sometimes indicators of the ultimate effect that exposure to a given
stimulus will have on the well-being (survival, reproduction, etc.) of
an animal (see Figure 2). There is little marine mammal data
quantitatively relating the exposure of marine mammals to sound to
effects on reproduction or survival, though data exists for terrestrial
species to which we can draw comparisons for marine mammals.
Attention is the cognitive process of selectively concentrating on
one aspect of an animal's environment while ignoring other things
(Posner, 1994). Because animals (including humans) have limited
cognitive resources, there is a limit to how much sensory information
they can process at any time. The phenomenon called ``attentional
capture'' occurs when a stimulus (usually a stimulus that an animal is
not concentrating on or attending to) ``captures'' an animal's
attention. This shift in attention can occur consciously or
unconsciously (for example, when an animal hears sounds that it
associates with the approach of a predator) and the shift in attention
can be sudden (Dukas, 2002; van Rij, 2007). Once a stimulus has
captured an animal's attention, the animal can respond by ignoring the
stimulus, assuming a ``watch and wait'' posture, or treat the stimulus
as a disturbance and respond accordingly, which includes scanning for
the source of the stimulus or ``vigilance'' (Cowlishaw et al., 2004).
Vigilance is normally an adaptive behavior that helps animals
determine the presence or absence of predators, assess their distance
from conspecifics, or to attend cues from prey (Bednekoff and
Lima,1998; Treves, 2000). Despite those benefits, however, vigilance
has a cost of time: when animals focus their attention on specific
environmental cues, they are not attending to other activities such a
foraging. These costs have been documented best in foraging animals,
where vigilance has been shown to substantially reduce feeding rates
(Saino, 1994; Beauchamp and Livoreil, 1997; Fritz et al., 2002).
Animals will spend more time being vigilant, which may translate to
less time foraging or resting, when disturbance stimuli approach them
more directly, remain at closer distances, have a greater group size
(for example, multiple surface vessels), or when they co-occur with
times that an animal perceives increased risk (for example, when they
are giving birth or accompanied by a calf). Most of the published
literature, however, suggests that direct approaches will increase the
amount of time animals will dedicate to being vigilant. For example,
bighorn sheep and Dall's sheep dedicated more time being vigilant, and
less time resting or foraging, when aircraft made direct approaches
over them (Frid, 2001; Stockwell et al., 1991).
Several authors have established that long-term and intense
disturbance stimuli can cause population declines by reducing the body
condition of individuals that have been disturbed, followed by reduced
reproductive success, reduced survival, or both (Daan et al., 1996;
Madsen, 1994; White, 1983). For example, Madsen (1994) reported that
pink-footed geese (Anser brachyrhynchus) in undisturbed habitat gained
body mass and had about a 46-percent reproductive success compared with
geese in disturbed habitat (being consistently scared off the fields on
which they were foraging) which did not gain mass and has a 17 percent
reproductive success. Similar reductions in reproductive success have
been reported for mule deer (Odocoileus hemionus) disturbed by all-
terrain vehicles (Yarmoloy et al., 1988), caribou disturbed by seismic
exploration blasts (Bradshaw et al., 1998), caribou disturbed by low-
elevation military jet-fights (Luick et al., 1996), and caribou
disturbed by low-elevation jet flights (Harrington and Veitch, 1992).
Similarly, a study of elk (Cervus elaphus) that were disturbed
experimentally by pedestrians concluded that the ratio of young to
mothers was inversely related to disturbance rate (Phillips and
Alldredge, 2000).
The primary mechanism by which increased vigilance and disturbance
appear to affect the fitness of individual animals is by disrupting an
animal's time budget and, as a result, reducing the time they might
spend foraging and resting (which increases an animal's activity rate
and energy demand). For example, a study of grizzly bears (Ursus
horribilis) reported that bears disturbed by hikers reduced their
energy intake by an average of 12 kcal/min (50.2 x 103kJ/min), and
spent energy fleeing or acting aggressively toward hikers (White et al.
1999).
[[Page 35529]]
On a related note, many animals perform vital functions, such as
feeding, resting, traveling, and socializing, on a diel cycle (24-hr
cycle). Substantive behavioral reactions to noise exposure (such as
disruption of critical life functions, displacement, or avoidance of
important habitat) are more likely to be significant if they last more
than one diel cycle or recur on subsequent days (Southall et al.,
2007). Consequently, a behavioral response lasting less than one day
and not recurring on subsequent days is not considered particularly
severe unless it could directly affect reproduction or survival
(Southall et al., 2007).
Stranding and Mortality
When a live or dead marine mammal swims or floats onto shore and
becomes ``beached'' or incapable of returning to sea, the event is
termed a ``stranding'' (Geraci et al., 1999; Perrin and Geraci, 2002;
Geraci and Lounsbury, 2005; National Marine Fisheries Service, 2007p).
The legal definition for a stranding within the United States is that
``a marine mammal is dead and is (i) on a beach or shore of the United
States; or (ii) in waters under the jurisdiction of the United States
(including any navigable waters); or (B) a marine mammal is alive and
is (i) on a beach or shore of the United States and is unable to return
to the water; (ii) on a beach or shore of the United States and,
although able to return to the water, is in need of apparent medical
attention; or (iii) in the waters under the jurisdiction of the United
States (including any navigable waters), but is unable to return to its
natural habitat under its own power or without assistance.'' (16 U.S.C.
1421h).
Marine mammals are known to strand for a variety of reasons, such
as infectious agents, biotoxicosis, starvation, fishery interaction,
ship strike, unusual oceanographic or weather events, sound exposure,
or combinations of these stressors sustained concurrently or in series.
However, the cause or causes of most stranding are unknown (Geraci et
al., 1976; Eaton, 1979, Odell et al., 1980; Best, 1982). Numerous
studies suggest that the physiology, behavior, habitat relationships,
age, or condition of cetaceans may cause them to strand or might pre-
dispose them the strand when exposed to another phenomenon. These
suggestions are consistent with the conclusions of numerous other
studies that have demonstrated that combinations of dissimilar
stressors commonly combine to kill an animal or dramatically reduce its
fitness, even though one exposure without the other does not produce
the same result (Chroussos, 2000; Creel, 2005; DeVries et al., 2003;
Fair and Becker, 2000; Foley et al., 2001; Moberg, 2000; Relyea, 2005a;
2005b, Romero, 2004; Sih et al., 2004).
Several sources have published lists of mass stranding events of
cetaceans during attempts to identify relationships between those
stranding events and military sonar (Hildebrand, 2004; IWC, 2005;
Taylor et al., 2004). For example, based on a review of stranding
records between 1960 and 1995, the International Whaling Commission
(2005) identified ten mass stranding events of Cuvier's beaked whales
had been reported and one mass stranding of four Baird's beaked whales
(Berardius bairdii). The IWC concluded that, out of eight stranding
events reported from the mid-1980s to the summer of 2003, seven had
been associated with the use of mid-frequency sonar, one of those seven
had been associated with the use of low-frequency sonar, and the
remaining stranding event had been associated with the use of seismic
airguns.
Most of the stranding events reviewed by the International Whaling
Commission involved beaked whales. A mass stranding of Cuvier's beaked
whales in the eastern Mediterranean Sea occurred in 1996 (Frantzis,
1998) and mass stranding events involving Gervais' beaked whales,
Blainville's beaked whales, and Cuvier's beaked whales occurred off the
coast of the Canary Islands in the late 1980s (Simmonds and Lopez-
Jurado, 1991). The stranding events that occurred in the Canary Islands
and Kyparissiakos Gulf in the late 1990s and the Bahamas in 2000 have
been the most intensively-studied mass stranding events and have been
associated with naval maneuvers that were using sonar.
Between 1960 and 2006, 48 strandings (68 percent) involved beaked
whales, 3 (4 percent) involved dolphins, and 14 (20 percent) involved
other whale species. Cuvier's beaked whales were involved in the
greatest number of these events (48 or 68 percent), followed by sperm
whales (7 or 10 percent), and Blainville's and Gervais' beaked whales
(4 each or 6 percent). Naval activities that might have involved active
sonar are reported to have coincided with 9 (13 percent) or 10 (14
percent) of those stranding events. Between the mid-1980s and 2003 (the
period reported by the International Whaling Commission), we identified
reports of 44 mass cetacean stranding events of which at least 7 were
coincident with naval exercises that were using mid-frequency sonar.
Strandings Associated With MFAS
Over the past 12 years, there have been five stranding events
coincident with military mid-frequency sonar use that are believed to
most likely have been caused by exposure to the sonar: Greece (1996);
the Bahamas (2000); Madeira (2000); Canary Islands (2002); and Spain
(2006). In 2004, during the RIMPAC exercises, between 150-200 usually
pelagic melon-headed whales occupied the shallow waters of the Hanalei
Bay, Kaua'i, Hawaii for over 28 hours. NMFS determined that the mid-
frequency sonar was a plausible, if not likely, contributing factor in
what may have been a confluence of events that led to the Hanalei Bay
stranding. A number of other stranding events coincident with the
operation of mid-frequency sonar and resulting in the death of beaked
whales or other species (Minke whales, dwarf sperm whales, pilot
whales) have been reported; however, the majority have not been
investigated to the degree necessary to determine the cause of the
stranding.
Greece (1996)
Twelve Cuvier's beaked whales stranded atypically (in both time and
space) along a 38.2-kilometer strand of the coast of the Kyparissiakos
Gulf on May 12 and 13, 1996 (Frantzis, 1998). From May 11 through May
15, the NATO research vessel Alliance was conducting sonar tests with
signals of 600 Hz and 3 kHz and rms SPL of 228 and 226 dB re: 1 [mu]Pa,
respectively (D'Amico and Verboom, 1998; D'Spain et al., 2006). The
timing and the location of the testing encompassed the time and
location of the whale strandings (Frantzis, 1998).
Necropsies of eight of the animals were performed, but were limited
to basic external examination and sampling of stomach contents, blood,
and skin. No ears or organs were collected, and no histological samples
were preserved. No apparent abnormalities or wounds were found
(Frantzis, 2004). Examination of photos of the animals revealed that
the eyes of at least four of the individuals were bleeding. Photos were
taken soon after their death (Frantzis, 2004). Stomach contents
contained the flesh of cephalopods, indicating that feeding had
recently taken place (Frantzis, 1998).
All available information regarding the conditions associated with
this stranding was compiled, and many potential causes were examined
including major pollution events, important tectonic activity, unusual
physical or meteorological events,
[[Page 35530]]
magnetic anomalies, epizootics, and conventional military activities
(International Council for the Exploration of the Sea, 2005a). However,
none of these potential causes coincided in time with the mass
stranding, or could explain its characteristics (International Council
for the Exploration of the Sea, 2005a). The robust condition of the
animals, plus the recent stomach contents, is not consistent with
pathogenic causes (Frantzis, 2004). In addition, environmental causes
can be ruled out as there were no unusual environmental circumstances
or events before or during this time period (Frantzis, 2004).
It was determined that because of the rarity of this mass stranding
of Cuvier's beaked whales in the Kyparissiakos Gulf (first one in
history), the probability for the two events (the military exercises
and the strandings) to coincide in time and location, while being
independent of each other, was extremely low (Frantzis, 1998). However,
because full necropsies had not been conducted, and no abnormalities
were noted, the cause of the strandings could not be precisely
determined (Cox et al., 2006). The analysis of this stranding event
provided support for, but no clear evidence for, the cause-and-effect
relationship of sonar training activities and beaked whale strandings
(Cox et al., 2006).
Bahamas (2000)
NMFS and the Navy prepared a joint report addressing the multi-
species stranding in the Bahamas in 2000, which took place within 24
hours of U.S. Navy ships using MFAS as they passed through the
Northeast and Northwest Providence Channels on March 15-16, 2000. The
ships, which operated both AN/SQS-53C and AN/SQS-56, moved through the
channel while emitting sonar pings approximately every 24 seconds. Of
the 17 cetaceans that stranded over a 36-hr period (Cuvier's beaked
whales, Blainville's beaked whales, Minke whales, and a spotted
dolphin), 7 animals died on the beach (5 Cuvier's beaked whales, 1
Blainville's beaked whale, and the spotted dolphin) and the other 10
were returned to the water alive (though their fate is unknown).
Necropsies were performed on five beaked whales. All five
necropsied beaked whales were in good body condition, showing no signs
of infection, disease, ship strike, blunt trauma, or fishery related
injuries, and three still had food remains in their stomachs. Auditory
structural damage was discovered in four of the whales, specifically
bloody effusions or hemorrhaging around the ears. Bilateral
intracochlear and unilateral temporal region subarachnoid hemorrhage
with blood clots in the lateral ventricles were found in two of the
whales. Three of the whales had small hemorrhages in their acoustic
fats (located along the jaw and in the melon).
A comprehensive investigation was conducted and all possible causes
of the stranding event were considered, whether they seemed likely at
the outset or not. Based on the way in which the strandings coincided
with ongoing naval activity involving tactical mid-frequency sonar use,
in terms of both time and geography, the nature of the physiological
effects experienced by the dead animals, and the absence of any other
acoustic sources, the investigation team concluded that mid-frequency
sonars aboard U.S. Navy ships that were in use during the sonar
exercise in question were the most plausible source of this acoustic or
impulse trauma. This sound source was active in a complex environment
that included the presence of a surface duct, unusual and steep
bathymetry, a constricted channel with limited egress, intensive use of
multiple, active sonar units over an extended period of time, and the
presence of beaked whales that appear to be sensitive to the
frequencies produced by these sonars. The investigation team concluded
that the cause of this stranding event was the confluence of the Navy
mid-frequency sonar and these contributory factors working together,
and further recommended that the Navy avoid operating mid-frequency
sonar in situations where these five factors would be likely to occur.
This report does not conclude that all five of these factors must be
present for a stranding to occur, nor that beaked whales are the only
species that could potentially be affected by the confluence of the
other factors. Based on this, NMFS believes that the presence of
surface ducts, steep bathymetry, and/or constricted channels added to
the operation of mid-frequency sonar in the presence of cetaceans
(especially beaked whales and, potentially, deep divers) may increase
the likelihood of producing a sound field with the potential to cause
cetaceans to strand, and therefore, suggests the need for increased
vigilance while operating MFAS/HFAS.
Madeira, Spain (2000)
From May 10-14, 2000, three Cuvier's beaked whales were found
atypically stranded on two islands in the Madeira archipelago, Portugal
(Cox et al., 2006). A fourth animal was reported floating in the
Madeiran waters by fisherman, but did not come ashore (Woods Hole
Oceanographic Institution, 2005). Joint NATO amphibious training
peacekeeping exercises involving participants from 17 countries and 80
warships took place in Portugal during May 2-15, 2000.
The bodies of the three stranded whales were examined post mortem
(Woods Hole Oceanographic Institution, 2005), though only one of the
stranded whales was fresh enough (24 hours after stranding) to be
necropsied (Cox et al., 2006). Results from the necropsy revealed
evidence of hemorrhage and congestion in the right lung and both
kidneys (Cox et al., 2006). There was also evidence of intercochlear
and intracranial hemorrhage similar to that which was observed in the
whales that stranded in the Bahamas event (Cox et al., 2006). There
were no signs of blunt trauma, and no major fractures (Woods Hole
Oceanographic Institution, 2005). The cranial sinuses and airways were
found to be quite clear with little or no fluid deposition, which may
indicate good preservation of tissues (Woods Hole Oceanographic
Institution, 2005).
Several observations on the Madeira stranded beaked whales, such as
the pattern of injury to the auditory system, are the same as those
observed in the Bahamas strandings. Blood in and around the eyes,
kidney lesions, pleural hemorrhages, and congestion in the lungs are
particularly consistent with the pathologies from the whales stranded
in the Bahamas, and are consistent with stress and pressure related
trauma. The similarities in pathology and stranding patterns between
these two events suggest that a similar pressure event may have
precipitated or contributed to the strandings at both sites (Woods Hole
Oceanographic Institution, 2005).
Even though no definitive causal link can be made between the
stranding event and naval exercises, certain conditions may have
existed in the exercise area that, in their aggregate, may have
contributed to the marine mammal strandings (Freitas, 2004): Exercises
were conducted in areas of at least 547 fathoms (1000 m) depth near a
shoreline where there is a rapid change in bathymetry on the order of
547 to 3,281 fathoms (1000-6000 m) occurring across a relatively short
horizontal distance (Freitas, 2004); multiple ships were operating
around Madeira, though it is not known if MFA sonar was used, and the
specifics of the sound sources used are unknown (Cox et al., 2006,
Freitas, 2004); exercises took place in an area surrounded by
landmasses separated by less than 35 nm (65 km) and at least 10 nm (19
km) in length, or in an embayment. Exercises
[[Page 35531]]
involving multiple ships employing MFA near land may produce sound
directed towards a channel or embayment that may cut off the lines of
egress for marine mammals (Freitas, 2004).
Canary Islands, Spain (2002)
The southeastern area within the Canary Islands is well known for
aggregations of beaked whales due to its ocean depths of greater than
547 fathoms (1000 m) within a few hundred meters of the coastline
(Fernandez et al., 2005). On September 24, 2002, 14 beaked whales were
found stranded on Fuerteventura and Lanzarote Islands in the Canary
Islands (International Council for Exploration of the Sea, 2005a).
Seven whales died, while the remaining seven live whales were returned
to deeper waters (Fernandez et al., 2005). Four beaked whales were
found stranded dead over the next 3 days either on the coast or
floating offshore. These strandings occurred within near proximity of
an international naval exercise that utilized MFAS and involved
numerous surface warships and several submarines. Strandings began
about 4 hours after the onset of MFA sonar activity (International
Council for Exploration of the Sea, 2005a; Fernandez et al., 2005).
Eight Cuvier's beaked whales, one Blainville's beaked whale, and
one Gervais' beaked whale were necropsied, six of them within 12 hours
of stranding (Fernandez et al., 2005). No pathogenic bacteria were
isolated from the carcasses (Jepson et al., 2003). The animals
displayed severe vascular congestion and hemorrhage especially around
the tissues in the jaw, ears, brain, and kidneys, displaying marked
disseminated microvascular hemorrhages associated with widespread fat
emboli (Jepson et al., 2003; International Council for Exploration of
the Sea, 2005a). Several organs contained intravascular bubbles,
although definitive evidence of gas embolism in vivo is difficult to
determine after death (Jepson et al., 2003). The livers of the
necropsied animals were the most consistently affected organ, which
contained macroscopic gas-filled cavities and had variable degrees of
fibrotic encapsulation. In some animals, cavitary lesions had
extensively replaced the normal tissue (Jepson et al., 2003). Stomachs
contained a large amount of fresh and undigested contents, suggesting a
rapid onset of disease and death (Fernandez et al., 2005). Head and
neck lymph nodes were enlarged and congested, and parasites were found
in the kidneys of all animals (Fernandez et al., 2005).
The association of NATO MFA sonar use close in space and time to
the beaked whale strandings, and the similarity between this stranding
event and previous beaked whale mass strandings coincident with sonar
use, suggests that a similar scenario and causative mechanism of
stranding may be shared between the events. Beaked whales stranded in
this event demonstrated brain and auditory system injuries,
hemorrhages, and congestion in multiple organs, similar to the
pathological findings of the Bahamas and Madeira stranding events. In
addition, the necropsy results of the Canary Islands stranding event
lead to the hypothesis that the presence of disseminated and widespread
gas bubbles and fat emboli were indicative of nitrogen bubble
formation, similar to what might be expected in decompression sickness
(Jepson et al., 2003; Fernandez et al., 2005).
Spain (2006)
The Spanish Cetacean Society reported an atypical mass stranding of
four beaked whales that occurred January 26, 2006, on the southeast
coast of Spain, near Mojacar (Gulf of Vera) in the Western
Mediterranean Sea. According to the report, two of the whales were
discovered the evening of January 26 and were found to be still alive.
Two other whales were discovered during the day on January 27, but had
already died. The fourth animal was found dead on the afternoon of May
27, a few kilometers north of the first three animals. From January 25-
26, 2006, Standing North Atlantic Treaty Organization (NATO) Response
Force Maritime Group Two (five of seven ships including one U.S. ship
under NATO Operational Control) had conducted active sonar training
against a Spanish submarine within 50 nm (93 km) of the stranding site.
Veterinary pathologists necropsied the two male and two female
Cuvier's beaked whales. According to the pathologists, the most likely
primary cause of this type of beaked whale mass stranding event was
anthropogenic acoustic activities, most probably anti-submarine MFAS
used during the military naval exercises. However, no positive acoustic
link was established as a direct cause of the stranding. Even though no
causal link can be made between the stranding event and naval
exercises, certain conditions may have existed in the exercise area
that, in their aggregate, may have contributed to the marine mammal
strandings (Freitas, 2004): Exercises were conducted in areas of at
least 547 fathoms (1000 m) depth near a shoreline where there is a
rapid change in bathymetry on the order of 547 to 3,281 fathoms (1000-
6000 m) occurring across a relatively short horizontal distance
(Freitas, 2004); Multiple ships (in this instance, five) were operating
MFAS in the same area over extended periods of time (in this case, 20
hours) in close proximity; Exercises took place in an area surrounded
by landmasses, or in an embayment. Exercises involving multiple ships
employing MFA sonar near land may have produced sound directed towards
a channel or embayment that may have cut off the lines of egress for
the affected marine mammals (Freitas, 2004).
Hanalei Bay (2004)
On July 3-4, 2004, approximately 150-200 melon-headed whales
occupied the shallow waters of the Hanalei Bay, Kaua'i, Hawaii for over
28 hours. Attendees of a canoe blessing observed the animals entering
the Bay in a single wave formation at 7 a.m. on July 3, 2004. The
animals were observed moving back into the shore from the mouth of the
Bay at 9 a.m. The usually pelagic animals milled in the shallow bay and
were returned to deeper water with human assistance beginning at 9:30
a.m. on July 4, 2004, and were out of sight by 10:30 a.m.
Only one animal, a calf, was known to have died following this
event. The animal was noted alive and alone in the Bay on the afternoon
of July 4, 2004 and was found dead in the Bay the morning of July 5,
2004. A full necropsy, magnetic resonance imaging, and computerized
tomography examination were performed on the calf to determine the
manner and cause of death. The combination of imaging, necropsy and
histological analyses found no evidence of infectious, internal
traumatic, congenital, or toxic factors. Although cause of death could
not be definitively determined, it is likely that maternal separation,
poor nutritional condition, and dehydration contributed to the final
demise of the animal. Although we do not know when the calf was
separated from its mother, the movement into the Bay, the milling and
re-grouping may have contributed to the separation or lack of nursing
especially if the maternal bond was weak or this was a primiparous
calf.
Environmental factors, abiotic and biotic, were analyzed for any
anomalous occurrences that would have contributed to the animals
entering and remaining in Hanalei Bay. The Bay's bathymetry is similar
to many other sites within the Hawaiian Island chain
[[Page 35532]]
and dissimilar to sites that have been associated with mass strandings
in other parts of the United States. The weather conditions appeared to
be normal for that time of year with no fronts or other significant
features noted. There was no evidence of unusual distribution or
occurrence of predator or prey species, or unusual harmful algal
blooms. Weather patterns and bathymetry that have been associated with
mass strandings elsewhere were not found to occur in this instance.
A separate event involving melon-headed whales and rough-toothed
dolphins took place over the same period of time in the Northern
Mariana Islands (Jefferson et al., 2006), which is several thousand
miles from Hawaii. Some 500-700 melon-headed whales came into Sasanhaya
Bay on 4 July 2004 on the island of Rota and then left of their own
accord after 5.5 hours; no known active sonar transmissions occurred in
the vicinity of that event. Global reports of these types of events or
sightings are of great interest to the scientific community and
continuing efforts to enhance reporting in island nations will
contribute to our increased understanding of animal behavior and
potential causes of stranding events. Exactly what, if any,
relationship this event has to the simultaneous events in Hawai'i and
whether they might be related to some common factor (e.g., there was a
full moon on July 2, 2004) is and will likely remain unknown. However,
these two synchronous, nearshore events involving a rarely-sighted
species are curious and may point to the range of potential
contributing factors for which we lack detailed understanding and which
the authors acknowledged might have played some role in the
``confluence of events'' in Hanalei Bay.
The Hanalei event was spatially and temporally correlated with
RIMPAC. Official sonar training and tracking exercises in the Pacific
Missile Range Facility (PMRF) warning area did not commence until
approximately 8 a.m. on July 3 and were thus ruled out as a possible
trigger for the initial movement into the Bay.
However, six naval surface vessels transiting to the operational
area on July 2 intermittently transmitted active sonar (for
approximately 9 hours total from 1:15 p.m. to 12:30 a.m.) as they
approached from the south. The potential for these transmissions to
have triggered the whales' movement into Hanalei Bay was investigated.
Analyses with the information available indicated that animals to the
south and east of Kaua'i could have detected active sonar transmissions
on July 2, and reached Hanalei Bay on or before 7 a.m. on July 3, 2004.
However, data limitations regarding the position of the whales prior to
their arrival in the Bay, the magnitude of sonar exposure, behavioral
responses of melon-headed whales to acoustic stimuli, and other
possible relevant factors preclude a conclusive finding regarding the
role of sonar in triggering this event. Propagation modeling suggest
that transmissions from sonar use during the July 3 exercise in the
PMRF warning area may have been detectable at the mouth of the Bay. If
the animals responded negatively to these signals, it may have
contributed to their continued presence in the Bay. The U.S. Navy
ceased all active sonar transmissions during exercises in this range on
the afternoon of July 3, 2004. Subsequent to the cessation of sonar
use, the animals were herded out of the Bay.
While causation of this stranding event may never be unequivocally
determined, we consider the active sonar transmissions of July 2-3,
2004, a plausible, if not likely, contributing factor in what may have
been a confluence of events. This conclusion is based on: (1) The
evidently anomalous nature of the stranding; (2) its close
spatiotemporal correlation with wide-scale, sustained use of sonar
systems previously associated with stranding of deep-diving marine
mammals; (3) the directed movement of two groups of transmitting
vessels toward the southeast and southwest coast of Kauai; (4) the
results of acoustic propagation modeling and an analysis of possible
animal transit times to the Bay; and (5) the absence of any other
compelling causative explanation. The initiation and persistence of
this event may have resulted from an interaction of biological and
physical factors. The biological factors may have included the presence
of an apparently uncommon, deep-diving cetacean species (and possibly
an offshore, non-resident group), social interactions among the animals
before or after they entered the Bay, and/or unknown predator or prey
conditions. The physical factors may have included the presence of
nearby deep water, multiple vessels transiting in a directed manner
while transmitting active sonar over a sustained period, the presence
of surface sound ducting conditions, and/or intermittent and random
human interactions while the animals were in the Bay.
Association Between Mass Stranding Events and Exposure to MFAS
Several authors have noted similarities between some of these
stranding incidents: they occurred in islands or archipelagoes with
deep water nearby, several appeared to have been associated with
acoustic waveguides like surface ducting, and the sound fields created
by ships transmitting mid-frequency sonar (Cox et al., 2006, D'Spain et
al., 2006). Although Cuvier's beaked whales have been the most common
species involved in these stranding events (81 percent of the total
number of stranded animals and see Figure 3), other beaked whales
(including Mesoplodon europeaus, M. densirostris, and Hyperoodon
ampullatus) comprise 14 percent of the total. Other species (Stenella
coeruleoalba, Kogia breviceps and Balaenoptera acutorostrata) have
stranded, but in much lower numbers and less consistently than beaked
whales.
Based on the evidence available, however, we cannot determine
whether (a) Cuvier's beaked whale is more prone to injury from high-
intensity sound than other species, (b) their behavioral responses to
sound makes them more likely to strand, or (c) they are more likely to
be exposed to mid-frequency active sonar than other cetaceans (for
reasons that remain unknown). Because the association between active
sonar exposures and marine mammals mass stranding events is not
consistent--some marine mammals strand without being exposed to sonar
and some sonar transmissions are not associated with marine mammal
stranding events despite their co-occurrence--other risk factors or a
groupings of risk factors probably contribute to these stranding
events.
Behaviorally Mediated Responses to MFAS/HFAS That May Lead to Stranding
Although the confluence of Navy mid-frequency active tactical sonar
with the other contributory factors noted in the report was identified
as the cause of the 2000 Bahamas stranding event, the specific
mechanisms that led to that stranding (or the others) are not
understood, and there is uncertainty regarding the ordering of effects
that led to the stranding. It is unclear whether beaked whales were
directly injured by sound (acoustically mediated bubble growth,
addressed above) prior to stranding or whether a behavioral response to
sound occurred that ultimately caused the beaked whales be injured and
strand.
Although causal relationships between beaked whale stranding events
and active sonar remain unknown, several authors have hypothesized that
stranding events involving these species in the Bahamas and Canary
Islands may
[[Page 35533]]
have been triggered when the whales changed their dive behavior in a
startled response to exposure to active sonar or to further avoid
exposure (Cox et al., 2006, Rommel et al., 2006). These authors
proposed two mechanisms by which the behavioral responses of beaked
whales upon being exposed to active sonar might result in a stranding
event. These include: gas bubble formation caused by excessively fast
surfacing; remaining at the surface too long when tissues are
supersaturated with nitrogen; or diving prematurely when extended time
at the surface is necessary to eliminate excess nitrogen. More
specifically, beaked whales that occur in deep waters that are in close
proximity to shallow waters (for example, the ``canyon areas'' that are
cited in the Bahamas stranding event; see D'Spain and D'Amico, 2006),
may respond to active sonar by swimming into shallow waters to avoid
further exposures and strand if they were not able to swim back to
deeper waters. Second, beaked whales exposed to active sonar might
alter their dive behavior. Changes in their dive behavior might cause
them to remain at the surface or at depth for extended periods of time
which could lead to hypoxia directly by increasing their oxygen demands
or indirectly by increasing their energy expenditures (to remain at
depth) and increase their oxygen demands as a result. If beaked whales
are at depth when they detect a ping from an active sonar transmission
and change their dive profile, this could lead to the formation of
significant gas bubbles, which could damage multiple organs or
interfere with normal physiological function (Cox et al., 2006; Rommel
et al., 2006; Zimmer and Tyack, 2007). Baird et al. (2005) found that
slow ascent rates from deep dives and long periods of time spent within
50 m of the surface were typical for both Cuvier's and Blainville's
beaked whales, the two species involved in mass strandings related to
naval sonar. These two behavioral mechanisms may be necessary to purge
excessive dissolved nitrogen concentrated in their tissues during their
frequent long dives (Baird et al., 2005). Baird et al. (2005) further
suggests that abnormally rapid ascents or premature dives in response
to high-intensity sonar could indirectly result in physical harm to the
beaked whales, through the mechanisms described above (gas bubble
formation or non-elimination of excess nitrogen).
Because many species of marine mammals make repetitive and
prolonged dives to great depths, it has long been assumed that marine
mammals have evolved physiological mechanisms to protect against the
effects of rapid and repeated decompressions. Although several
investigators have identified physiological adaptations that may
protect marine mammals against nitrogen gas supersaturation (alveolar
collapse and elective circulation; Kooyman et al., 1972; Ridgway and
Howard, 1979), Ridgway and Howard (1979) reported that bottlenose
dolphins (Tursiops truncatus) that were trained to dive repeatedly had
muscle tissues that were substantially supersaturated with nitrogen
gas. Houser et al. (2001) used these data to model the accumulation of
nitrogen gas within the muscle tissue of other marine mammal species
and concluded that cetaceans that dive deep and have slow ascent or
descent speeds would have tissues that are more supersaturated with
nitrogen gas than other marine mammals. Based on these data, Cox et al.
(2006) hypothesized that a critical dive sequence might make beaked
whales more prone to stranding in response to acoustic exposures. The
sequence began with (1) very deep (to depths as deep as 2 kilometers)
and long (as long as 90 minutes) foraging dives with (2) relatively
slow, controlled ascents, followed by (3) a series of ``bounce'' dives
between 100 and 400 meters in depth (also see Zimmer and Tyack, 2007).
They concluded that acoustic exposures that disrupted any part of this
dive sequence (for example, causing beaked whales to spend more time at
surface without the bounce dives that are necessary to recover from the
deep dive) could produce excessive levels of nitrogen supersaturation
in their tissues, leading to gas bubble and emboli formation that
produces pathologies similar to decompression sickness.
Recently, Zimmer and Tyack (2007) modeled nitrogen tension and
bubble growth in several tissue compartments for several hypothetical
dive profiles and concluded that repetitive shallow dives (defined as a
dive where depth does not exceed the depth of alveolar collapse,
approximately 72 m for Ziphius), perhaps as a consequence of an
extended avoidance reaction to sonar sound, could pose a risk for
decompression sickness and that this risk should increase with the
duration of the response. Their models also suggested that
unrealistically rapid ascent rates of ascent from normal dive behaviors
are unlikely to result in supersaturation to the extent that bubble
formation would be expected. Tyack et al. (2006) suggested that emboli
observed in animals exposed to mid-frequency range sonar (Jepson et
al., 2003; Fernandez et al., 2005) could stem from a behavioral
response that involves repeated dives shallower than the depth of lung
collapse. Given that nitrogen gas accumulation is a passive process
(i.e. nitrogen is metabolically inert), a bottlenose dolphin was
trained to repetitively dive a profile predicted to elevate nitrogen
saturation to the point that nitrogen bubble formation was predicted to
occur. However, inspection of the vascular system of the dolphin via
ultrasound did not demonstrate the formation of asymptomatic nitrogen
gas bubbles (Houser et al., 2007).
If marine mammals respond to a Navy vessel that is transmitting
active sonar in the same way that they might respond to a predator,
their probability of flight responses should increase when they
perceive that Navy vessels are approaching them directly, because a
direct approach may convey detection and intent to capture (Burger and
Gochfeld, 1981, 1990; Cooper, 1997, 1998). The probability of flight
responses should also increase as received levels of active sonar
increase (and the ship is, therefore, closer) and as ship speeds
increase (that is, as approach speeds increase). For example, the
probability of flight responses in Dall's sheep (Ovis dalli dalli)
(Frid 2001a, b), ringed seals (Phoca hispida) (Born et al., 1999),
Pacific brant (Branta bernic nigricans) and Canada geese (B.
Canadensis) increased as a helicopter or fixed-wing aircraft approached
groups of these animals more directly (Ward et al., 1999). Bald eagles
(Haliaeetus leucocephalus) perched on trees alongside a river were also
more likely to flee from a paddle raft when their perches were closer
to the river or were closer to the ground (Steidl and Anthony, 1996).
Despite the many theories involving bubble formation (both as a
direct cause of injury (see Acoustically Mediated Bubble Growth
Section) and an indirect cause of stranding (See Behaviorally Mediated
Bubble Growth Section), Southall et al., (2007) summarizes that
scientific agreement or complete lack of information exists regarding
the following important points: (1) Received acoustical exposure
conditions for animals involved in stranding events; (2) pathological
interpretation of observed lesions in stranded marine mammals; (3)
acoustic exposure conditions required to induce such physical trauma
directly; (4) whether noise exposure may cause behavioral reactions
(such as atypical diving behavior) that secondarily cause bubble
formation and tissue damage; and (5) the extent the post mortem
artifacts
[[Page 35534]]
introduced by decomposition before sampling, handling, freezing, or
necropsy procedures affect interpretation of observed lesions.
During the HRC training exercises there will be use of multiple
sonar units in an area where three species of beaked whale species may
be present. A surface duct may be present in a limited area for a
limited period of time. Although most of the ASW training events will
take place in the deep ocean, some will occur in areas of high
bathymetric relief. However, none of the training events will take
place in a location having a constricted channel with limited egress
similar to the Bahamas (because none exist in the HRC). Consequently,
not all five of the environmental factors believed to contribute to the
Bahamas stranding (mid-frequency sonar, beaked whale presence, surface
ducts, steep bathymetry, and constricted channels with limited egress)
will be present during HRC ASW exercises. However, as mentioned
previously, NMFS recommends caution when steep bathymetry, surface
ducting conditions, or a constricted channel is present in addition to
the operation of mid-frequency tactical sonar and the presence of
cetaceans (especially beaked whales).
Exposure Underwater Detonation of Explosives
Some of the Navy's training exercises include the underwater
detonation of explosives. For many of the exercises discussed, inert
ordnance is used for a subset of the exercises. For exercises that
involve ``shooting'' at a target that is above the surface of the
water, underwater explosions only occur when the target is missed,
which is the minority of the time (the Navy has historical hit/miss
ratios and uses them in their exposure estimates). The underwater
explosion from a weapon would send a shock wave and blast noise through
the water, release gaseous by-products, create an oscillating bubble,
and cause a plume of water to shoot up from the water surface. The
shock wave and blast noise are of most concern to marine animals.
Depending on the intensity of the shock wave and size, location, and
depth of the animal, an animal can be injured, killed, suffer non-
lethal physical effects, experience hearing related effects with or
without behavioral responses, or exhibit temporary behavioral responses
or tolerance from hearing the blast sound. Generally, exposures to
higher levels of impulse and pressure levels would result in worse
impacts to an individual animal.
Injuries resulting from a shock wave take place at boundaries
between tissues of different density. Different velocities are imparted
to tissues of different densities, and this can lead to their physical
disruption. Blast effects are greatest at the gas-liquid interface
(Landsberg, 2000). Gas-containing organs, particularly the lungs and
gastrointestinal tract, are especially susceptible (Goertner, 1982;
Hill, 1978; Yelverton et al., 1973). In addition, gas-containing organs
including the nasal sacs, larynx, pharynx, trachea, and lungs may be
damaged by compression/expansion caused by the oscillations of the
blast gas bubble (Reidenberg and Laitman, 2003). Intestinal walls can
bruise or rupture, with subsequent hemorrhage and escape of gut
contents into the body cavity. Less severe gastrointestinal tract
injuries include contusions, petechiae (small red or purple spots
caused by bleeding in the skin), and slight hemorrhaging (Yelverton et
al., 1973).
Because the ears are the most sensitive to pressure, they are the
organs most sensitive to injury (Ketten, 2000). Sound-related damage
associated with blast noise can be theoretically distinct from injury
from the shock wave, particularly farther from the explosion. If an
animal is able to hear a noise, at some level it can damage its hearing
by causing decreased sensitivity (Ketten, 1995) (See Noise-induced
Threshold Shift Section above). Sound-related trauma can be lethal or
sublethal. Lethal impacts are those that result in immediate death or
serious debilitation in or near an intense source and are not,
technically, pure acoustic trauma (Ketten, 1995). Sublethal impacts
include hearing loss, which is caused by exposures to perceptible
sounds. Severe damage (from the shock wave) to the ears includes
tympanic membrane rupture, fracture of the ossicles, damage to the
cochlea, hemorrhage, and cerebrospinal fluid leakage into the middle
ear. Moderate injury implies partial hearing loss due to tympanic
membrane rupture and blood in the middle ear. Permanent hearing loss
also can occur when the hair cells are damaged by one very loud event,
as well as by prolonged exposure to a loud noise or chronic exposure to
noise. The level of impact from blasts depends on both an animal's
location and, at outer zones, on its sensitivity to the residual noise
(Ketten, 1995).
There have been fewer studies addressing the behavioral effects of
explosives on marine mammals than MFAS/HFAS. However, though the nature
of the sound waves emitted from an explosion is different (in shape and
rise time) from MFAS/HFAS, we still anticipate the same sorts of
behavioral responses (see Exposure to MFAS/HFAS:Behavioral Disturbance
Section) to result from repeated explosive detonations (a smaller range
of likely less severe responses would be expected to occur as a result
of exposure to a single explosive detonation).
Mitigation
In order to issue an incidental take authorization (ITA) under
Section 101(a)(5)(A) of the MMPA, NMFS must set forth the ``permissible
methods of taking pursuant to such activity, and other means of
effecting the least practicable adverse impact on such species or stock
and its habitat, paying particular attention to rookeries, mating
grounds, and areas of similar significance.'' The National Defense
Authorization Act (NDAA) of 2004 amended the MMPA as it relates to
military-readiness activities and the incidental take authorization
process such that ``least practicable adverse impact'' shall include
consideration of personnel safety, practicality of implementation, and
impact on the effectiveness of the ``military readiness activity''. The
training activities described in the HRC LOA application are considered
military readiness activities.
NMFS reviewed the proposed HRC activities and the proposed HRC
mitigation measures (which the Navy refers to as Protective Measures)
presented in the Navy's application to determine whether the activities
and mitigation measures were capable of achieving the least practicable
adverse effect on marine mammals. NMFS determined that further
discussion was necessary regarding: (1) Humpback whales congregating in
the winter in the shallow areas of the HRC in high densities to calve
and breed; and (2) the potential relationship between the operation of
MFAS/HFAS and marine mammal strandings. NMFS worked with the Navy to
identify additional practicable and effective mitigation measures,
which included a careful balancing of the likely benefit of any
particular measure to the marine mammals with the likely effect of that
measure on personnel safety, practicality of implementation, and impact
on the ``military-readiness activity''.
NMFS and the Navy developed two additional mitigation measures that
address the concerns mentioned above, including a humpback whale
cautionary area and a Stranding Response Plan. Included below are the
mitigation measures the Navy initially proposed
[[Page 35535]]
(see ``Mitigation Measures Proposed in the Navy's LOA Application'')
and the additional measures that NMFS and the Navy developed (see
``Additional Measures Developed by NMFS and the Navy'' below).
Separately, NMFS has previously received comments from the public
expressing concerns regarding potential delays between when marine
mammals are visually detected by watchstanders and when the sonar is
actually powered or shut down. NMFS and the Navy have discussed this
issue and determined the following: Naval operators and lookouts are
aware of the potential for a very small delay (up to about 4 seconds)
between detecting a marine mammal and powering down or shutting down
sonar and will take the actions necessary to ensure that sonar is
powered down or shut down when detected animals are within the
specified distance (for example, by initiating shut-down when animals
are approaching, but not quite within the designated distance).
Mitigation Measures Proposed in the Navy's LOA Application
This section includes the protective measures proposed by the Navy
and is taken directly from their application (with the exception of
headings, which have been modified for increased clarity within the
context of this proposed rule).
Navy's Protective Measures for MFAS/HFAS
Current protective measures employed by the Navy include applicable
training of personnel and implementation of activity specific
procedures resulting in minimization and/or avoidance of interactions
with protected resources.
Navy shipboard lookout(s) are highly qualified and experienced
observers of the marine environment. Their duties require that they
report all objects sighted in the water to the Officer of the Deck
(e.g., trash, a periscope, a marine mammal) and all disturbances (e.g.,
surface disturbance, discoloration) that may be indicative of a threat
to the vessel and its crew. There are personnel serving as lookouts on
station at all times (day and night) when a ship or surfaced submarine
is moving through the water.
Navy lookouts undergo extensive training in order to qualify as a
watchstander. This training includes on-the-job instruction under the
supervision of an experienced watchstander, followed by completion of
the Personal Qualification Standard program, certifying that they have
demonstrated the necessary skills (such as detection and reporting of
partially submerged objects and night observation techniques). In
addition to these requirements, many Fleet lookouts periodically
undergo a 2-day refresher training course.
The Navy includes marine species awareness as part of its training
for its bridge lookout personnel on ships and submarines. Marine
Species Awareness Training (MSAT) was updated in 2005, and the
additional training materials are now included as required training for
Navy lookouts. This training addresses the lookout's role in
environmental protection, laws governing the protection of marine
species, Navy stewardship commitments, and general observation
information to aid in avoiding interactions with marine species. Marine
species awareness and training is reemphasized by the following means:
Bridge personnel on ships and submarines--Personnel
utilize marine species awareness training techniques as standard
operating procedure, they have available a marine species visual
identification aid when marine mammals are sighted, and they receive
updates to the current marine species awareness training as
appropriate.
Aviation units--Pilots and air crew personnel whose
airborne duties during Anti-Submarine Warfare (ASW) training activities
include searching for submarine periscopes would be trained in marine
mammal spotting. These personnel would also be trained on the details
of the mitigation measures specific to both their platform and that of
the surface combatants with which they are associated.
Sonar personnel on ships, submarines, and ASW aircraft--
Both passive and active sonar operators on ships, submarines, and
aircraft utilize protective measures relative to their platform. The
Navy issues a Letter of Instruction for each Major Exercise which
mandates specific actions to be taken if a marine mammal is detected,
and these actions are standard operating procedure throughout the
exercise.
Implementation of these protective measures is required of all
units. The activities undertaken on a Navy vessel or aircraft are
highly controlled. The chain of command supervises these activities.
Failure to follow orders can result in disciplinary action.
Personnel Training
(a) All lookouts onboard platforms involved in ASW training events
will review the NMFS-approved Marine Species Awareness Training (MSAT)
material prior to use of midfrequency active sonar.
(b) All Commanding Officers, Executive Officers, and officers
standing watch on the Bridge will have reviewed the MSAT material prior
to a training event employing the use of mid-frequency active sonar.
(c) Navy lookouts will undertake extensive training in order to
qualify as a watchstander in accordance with the Lookout Training
Handbook (NAVEDTRA, 12968-D).
(d) Lookout training will include on-the-job instruction under the
supervision of a qualified, experienced watchstander. Following
successful completion of this supervised training period, Lookouts will
complete the Personal Qualification Standard program, certifying that
they have demonstrated the necessary skills (such as detection and
reporting of partially submerged objects). This does not forbid
personnel being trained as lookouts from being counted as those listed
in previous measures so long as supervisors monitor their progress and
performance.
(e) Lookouts will be trained in the most effective means to ensure
quick and effective communication within the command structure in order
to facilitate implementation of mitigation measures if marine species
are spotted.
Lookout and Watchstander Responsibilities
(a) On the bridge of surface ships, there will always be at least
three people on watch whose duties include observing the water surface
around the vessel.
(b) All surface ships participating in ASW exercises will, in
addition to the three personnel on watch noted previously, have at all
times during the exercise at least two additional personnel on watch as
lookouts.
(c) Personnel on lookout and officers on watch on the bridge will
have at least one set of binoculars available for each person to aid in
the detection of marine mammals.
(d) On surface vessels equipped with mid-frequency active sonar,
pedestal mounted ``Big Eye'' (20x110) binoculars will be present and in
good working order to assist in the detection of marine mammals in the
vicinity of the vessel.
(e) Personnel on lookout will employ visual search procedures
employing a scanning methodology in accordance with the Lookout
Training Handbook (NAVEDTRA 12968-B).
(f) After sunset and prior to sunrise, lookouts will employ Night
Lookouts Techniques in accordance with the Lookout Training Handbook.
[[Page 35536]]
(g) Personnel on lookout will be responsible for reporting all
objects or anomalies sighted in the water (regardless of the distance
from the vessel) to the Officer of the Deck, since any object or
disturbance (e.g., trash, periscope, surface disturbance,
discoloration) in the water may be indicative of a threat to the vessel
and its crew or indicative of a marine species that may need to be
avoided as warranted.
Operating Procedures
(a) A Letter of Instruction, Mitigation Measures Message or
Environmental Annex to the Operational Order will be issued prior to
the exercise to further disseminate the personnel training requirement
and general marine mammal mitigation measures.
(b) Commanding Officers will make use of marine species detection
cues and information to limit interaction with marine species to the
maximum extent possible consistent with safety of the ship.
(c) All personnel engaged in passive acoustic sonar operation
(including aircraft, surface ships, or submarines) will monitor for
marine mammal vocalizations and report the detection of any marine
mammal to the appropriate watch station for dissemination and
appropriate action.
(d) During mid-frequency active sonar training activities,
personnel will utilize all available sensor and optical systems (such
as Night Vision Goggles) to aid in the detection of marine mammals.
(e) Navy aircraft participating in exercises at sea will conduct
and maintain, when operationally feasible and safe, surveillance for
marine species of concern as long as it does not violate safety
constraints or interfere with the accomplishment of primary operational
duties.
(f) Aircraft with deployed sonobuoys will use only the passive
capability of sonobuoys when marine mammals are detected within 200
yards of the sonobuoy.
(g) Marine mammal detections will be immediately reported to
assigned Aircraft Control Unit for further dissemination to ships in
the vicinity of the marine species as appropriate where it is
reasonable to conclude that the course of the ship will likely result
in a closing of the distance to the detected marine mammal.
(h) Safety Zones--When marine mammals are detected by any means
(aircraft, shipboard lookout, or acoustically) the Navy will ensure
that MFAS transmission levels are limited to at least 6 dB below normal
operating levels if any detected marine mammals are within 1,000 yards
(914 m) of the sonar dome (the bow).
(i) Ships and submarines will continue to limit maximum MFAS
transmission levels by this 6-dB factor until the marine mammal has
been seen to leave the area, has not been detected for 30 minutes, or
the vessel has transited more than 2,000 yards (1828 m) beyond the
location of the last detection.
(ii) The Navy will ensure that MFAS transmissions will be limited
to at least 10 dB below the equipment's normal operating level if any
detected animals are within 500 yards (457 m) of the sonar dome. Ships
and submarines will continue to limit maximum ping levels by this 10-dB
factor until the marine mammal has been seen to leave the area, has not
been detected for 30 minutes, or the vessel has transited more than
2,000 yards (1828 m) beyond the location of the last detection.
(iii) The Navy will ensure that MFAS transmissions are ceased if
any detected marine mammals are within 200 yards (183 m) of the sonar
dome. MFAS will not resume until the marine mammal has been seen to
leave the area, has not been detected for 30 minutes, or the vessel has
transited more than 2,000 yards (1828 m) beyond the location of the
last detection.
(iv) Special conditions applicable for dolphins and porpoises only:
If, after conducting an initial maneuver to avoid close quarters with
dolphins or porpoises, the Officer of the Deck concludes that dolphins
or porpoises are deliberately closing to ride the vessel's bow wave, no
further mitigation actions are necessary while the dolphins or
porpoises continue to exhibit bow wave riding behavior.
(v) If the need for power-down should arise as detailed in ``Safety
Zones'' above, Navy shall follow the requirements as though they were
operating at 235 dB--the normal operating level (i.e., the first power-
down will be to 229 dB, regardless of at what level above 235 sonar was
being operated).
(i) Prior to start up or restart of active sonar, operators will
check that the Safety Zone radius around the sound source is clear of
marine mammals.
(j) Sonar levels (generally)--Navy will operate sonar at the lowest
practicable level, not to exceed 235 dB, except as required to meet
tactical training objectives.
(k) Helicopters shall observe/survey the vicinity of an ASW
Operation for 10 minutes before the first deployment of active
(dipping) sonar in the water.
(l) Helicopters shall not dip their sonar within 200 yards (183 m)
of a marine mammal and shall cease pinging if a marine mammal closes
within 200 yards (183 m) after pinging has begun.
(m) Submarine sonar operators will review detection indicators of
close-aboard marine mammals prior to the commencement of ASW training
activities involving active mid-frequency sonar.
Navy's Protective Measures for IEER
The following are protective measures for use with Extended Echo
Ranging/Improved Extended Echo Ranging (EER/IEER) given an explosive
source generates the acoustic wave used in this sonobuoy.
(a) Crews will conduct visual reconnaissance of the drop area prior
to laying their intended sonobuoy pattern. This search should be
conducted below 500 yards (457 m) at a slow speed, if operationally
feasible and weather conditions permit. In dual aircraft training
activities, crews are allowed to conduct coordinated area clearances.
(b) Crews shall conduct a minimum of 30 minutes of visual and
acoustic monitoring of the search area prior to commanding the first
post detonation. This 30-minute observation period may include pattern
deployment time.
(c) For any part of the briefed pattern where a post (source/
receiver sonobuoy pair) will be deployed within 1,000 yards (914 m) of
observed marine mammal activity, deploy the receiver ONLY and monitor
while conducting a visual search. When marine mammals are no longer
detected within 1,000 yards (914 m) of the intended post position, co-
locate the explosive source sonobuoy (AN/SSQ-110A) (source) with the
receiver.
(d) When able, crews will conduct continuous visual and aural
monitoring of marine mammal activity. This is to include monitoring of
own-aircraft sensors from first sensor placement to checking off
station and out of communication range of these sensors.
(e) Aural Detection: If the presence of marine mammals is detected
aurally, then that should cue the aircrew to increase the diligence of
their visual surveillance. Subsequently, if no marine mammals are
visually detected, then the crew may continue multi-static active
search.
(f) Visual Detection:
(i) If marine mammals are visually detected within 1,000 yards (914
m) of the explosive source sonobuoy (AN/SSQ-110A) intended for use,
then that payload shall not be detonated. Aircrews may utilize this
post once the marine mammals have not been re-sighted for 30 minutes,
or are observed
[[Page 35537]]
to have moved outside the 1,000 yards (914 m) safety buffer.
(ii) Aircrews may shift their multi-static active search to another
post, where marine mammals are outside the 1,000 yards (914 m) safety
buffer.
(g) Aircrews shall make every attempt to manually detonate the
unexploded charges at each post in the pattern prior to departing the
operations area by using the ``Payload 1 Release'' command followed by
the ``Payload 2 Release'' command. Aircrews shall refrain from using
the ``Scuttle'' command when two payloads remain at a given post.
Aircrews will ensure that a 1,000 yards (914 m) safety buffer, visually
clear of marine mammals, is maintained around each post as is done
during active search operations.
(h) Aircrews shall only leave posts with unexploded charges in the
event of a sonobuoy malfunction, an aircraft system malfunction, or
when an aircraft must immediately depart the area due to issues such as
fuel constraints, inclement weather, and in-flight emergencies. In
these cases, the sonobuoy will self-scuttle using the secondary or
tertiary method.
(i) Ensure all payloads are accounted for. Explosive source
sonobuoys (AN/SSQ-110A) that cannot be scuttled shall be reported as
unexploded ordnance via voice communications while airborne, then upon
landing via naval message.
(j) Mammal monitoring shall continue until out of own-aircraft
sensor range.
Navy's Protective Measures for Underwater Detonations
To ensure protection of marine mammals during underwater detonation
training and Mining Laying Training, the operating area must be
determined to be clear of marine mammals prior to detonation.
Implementation of the following mitigation measures continue to ensure
that marine mammals would not be exposed to temporary threshold shift
(TTS), PTS or injury from physical contact with training mine shapes
during Major Exercises.
Demolitions (DEMOs) and Mine Countermeasure (MCM) Training (Up to 20
lb)
Exclusion Zones--All mine warfare and mine countermeasure (MCM)
training activities involving the use of explosive charges must include
exclusion zones for marine mammals to prevent physical and/or acoustic
effects to those species. These exclusion zones shall extend in a 700-
yard (640 m) arc radius around the detonation site.
Pre-Exercise Surveys--For MCM training activities, pre-exercise
survey shall be conducted within 30 minutes prior to the commencement
of the scheduled explosive event. The survey may be conducted from the
surface, by divers, and/or from the air, and personnel shall be alert
to the presence of any marine mammal or sea turtle. Should such an
animal be present within the survey area, the exercise shall be paused
until the animal voluntarily leaves the area.
Post-Exercise Surveys--Surveys within the same radius shall also be
conducted within 30 minutes after the completion of the explosive
event.
Reporting--Any evidence of a marine mammal that may have been
injured or killed by the action shall be reported immediately to NMFS
and Commander, Pacific Fleet and Commander, Navy Region Southwest,
Environmental Director.
Mine Laying Training--Mine Laying Training involves aerial drops of
inert training shapes on floating targets. Aircrews are scored for
their ability to accurately hit the target although this operation does
not involve live ordnance, marine mammals have the potential to be
injured if they are in the immediate vicinity of a floating target;
therefore, the safety zone shall be clear of marine mammals and sea
turtles around the target location. Pre- and post-surveys and reporting
requirements outlined for underwater detonations shall be implemented
during Mine Laying Training. To the maximum extent feasible, the Navy
shall retrieve inert mine shapes dropped during Mine Laying Training.
SINKEX, GUNEX, MISSILEX, and BOMBEX
The selection of sites suitable for sinking exercises (SINKEXs)
involves a balance of operational suitability, requirements established
under the MPRSA permit granted to the Navy (40 CFR 229.2), and the
identification of areas with a low likelihood of encountering
endangered species act (ESA) listed species. To meet operational
suitability criteria, locations must be within a reasonable distance of
the target vessels' originating location. The locations should also be
close to active military bases to allow participating assets access to
shore facilities. For safety purposes, these locations should also be
in areas that are not generally used by non-military air or watercraft.
The MPRSA permit requires vessels to be sunk in waters which are at
least 1000 fathoms (3000 m) deep and at least 50 nm (92 km) from land.
In general, most listed species prefer areas with strong
bathymetric gradients and oceanographic fronts for significant
biological activity such as feeding and reproduction. Typical locations
include the continental shelf and shelf-edge.
Although the siting of the location for the exercise is not
regulated by a permit, the range clearance procedures used for gunnery
exercise (GUNEX), missile exercise (MISSILEX), and bombing exercise
(BOMBEX) are the same as those described immediately below for a
SINKEX.
The Navy has developed range clearance procedures to maximize the
probability of sighting any ships or protected species in the vicinity
of an exercise, which are as follows:
(a) All weapons firing would be conducted during the period 1 hour
after official sunrise to 30 minutes before official sunset.
(b) Extensive range clearance training activities would be
conducted in the hours prior to commencement of the exercise, ensuring
that no shipping is located within the hazard range of the longest-
range weapon being fired for that event.
(c) Prior to conducting the exercise, remotely sensed sea surface
temperature maps would be reviewed. SINKEX and air to surface missile
(ASM) Training activities would not be conducted within areas where
strong temperature discontinuities are present, thereby indicating the
existence of oceanographic fronts. These areas would be avoided because
concentrations of some listed species, or their prey, are known to be
associated with these oceanographic features.
(d) An exclusion zone with a radius of 1.0 nm (1.8 km) would be
established around each target. This exclusion zone is based on
calculations using a 449 kg (990 lb) H6 NEW high explosive source
detonated 5 feet (1.5 m) below the surface of the water, which yields a
distance of 0.85 nm (1.57 km) (cold season) and 0.89 nm (1.65 km) (warm
season) beyond which the received level is below the 182 dB re: 1 Pa
sec2 threshold established for the WINSTON S. CHURCHILL (DDG 81) shock
trials. An additional buffer of 0.5 nm (0.9 km) would be added to
account for errors, target drift, and animal movements. Additionally, a
safety zone, which extends from the exclusion zone at 1.0 nm (1.8 km)
out an additional 0.5 nm (0.9 km), would be surveyed. Together, the
zones extend out 2 nm (3.6 km) from the target.
(e) A series of surveillance over-flights would be conducted within
the exclusion and the safety zones, prior to and during the exercise,
when feasible. Survey protocol would be as follows:
(i) Overflights within the exclusion zone would be conducted in a
manner that optimizes the surface area of the
[[Page 35538]]
water observed. This may be accomplished through the use of the Navy's
Search and Rescue (SAR) Tactical Aid (TACAID). The SAR TACAID provides
the best search altitude, ground speed, and track spacing for the
discovery of small, possibly dark objects in the water based on the
environmental conditions of the day. These environmental conditions
include the angle of sun inclination, amount of daylight, cloud cover,
visibility, and sea state.
(ii) All visual surveillance activities would be conducted by Navy
personnel trained in visual surveillance. At least one member of the
mitigation team would have completed the Navy's marine mammal training
program for lookouts.
(iii) In addition to the overflights, the exclusion zone would be
monitored by passive acoustic means, when assets are available. This
passive acoustic monitoring would be maintained throughout the
exercise. Potential assets include sonobuoys, which can be utilized to
detect any vocalizing marine mammals (particularly sperm whales) in the
vicinity of the exercise. The sonobuoys would be re-seeded as necessary
throughout the exercise. Additionally, passive sonar onboard submarines
may be utilized to detect any vocalizing marine mammals in the area.
The OCE would be informed of any aural detection of marine mammals and
would include this information in the determination of when it is safe
to commence the exercise.
(iv) On each day of the exercise, aerial surveillance of the
exclusion and safety zones would commence two hours prior to the first
firing.
(v) The results of all visual, aerial, and acoustic searches would
be reported immediately to the OCE (Officer Conducting the Exercise).
No weapons launches or firing would commence until the OCE declares the
safety and exclusion zones free of marine mammals.
(vi) If a marine mammal observed within the exclusion zone is
diving, firing would be delayed until the animal is re-sighted outside
the exclusion zone, or 30 minutes has elapsed. After 30 minutes, if the
animal has not been re-sighted it would be assumed to have left the
exclusion zone. This is based on a typical dive time of 30 minutes for
traveling marine mammals. The OCE would determine if the marine mammal
is in danger of being adversely affected by commencement of the
exercise.
(vii) During breaks in the exercise of 30 minutes or more, the
exclusion zone would again be surveyed for any marine mammals. If
marine mammals are sighted within the exclusion zone, the OCE would be
notified, and the procedure described above would be followed.
(viii) Upon sinking of the vessel, a final surveillance of the
exclusion zone would be monitored for two hours, or until sunset, to
verify that no marine mammals were harmed.
(f) Aerial surveillance would be conducted using helicopters or
other aircraft based on necessity and availability. The Navy has
several types of aircraft capable of performing this task; however, not
all types are available for every exercise. For each exercise, the
available asset best suited for identifying objects on and near the
surface of the ocean would be used. These aircraft would be capable of
flying at the slow safe speeds necessary to enable viewing of marine
mammals with unobstructed, or minimally obstructed, downward and
outward visibility. The exclusion and safety zone surveys may be
cancelled in the event that a mechanical problem, emergency search and
rescue, or other similar and unexpected event preempts the use of one
of the aircraft onsite for the exercise.
(g) Every attempt would be made to conduct the exercise in sea
states that are ideal for marine mammal sighting, Beaufort Sea State 3
or less. In the event of a 4 or above, survey efforts would be
increased within the zones. This would be accomplished through the use
of an additional aircraft, if available, and conducting tight search
patterns.
(h) The exercise would not be conducted unless the exclusion zone
could be adequately monitored visually.
(i) In the unlikely event that any marine mammals are observed to
be harmed in the area, a detailed description of the animal would be
documented, the location noted, and if possible, photos taken. This
information would be provided to NMFS via the Navy's regional
environmental coordinator for purposes of identification.
Additional Mitigation Measures Developed by NMFS and the Navy
As mentioned above, NMFS worked with the Navy to identify
additional practicable and effective mitigation measures to address the
following two issues of concern: (1) Humpback whales congregating in
the winter in the shallow areas of the HRC in high densities to calve
and breed; and (2) the potential relationship between the operation of
MFAS/HFAS and marine mammal strandings. Any mitigation measure
prescribed by NMFS should be known to accomplish, have a reasonable
likelihood of accomplishing (based on current science), or contribute
to the accomplishment of one or more of the general goals listed below:
(a) Avoidance or minimization of injury or death of marine mammals
wherever possible (goals b, c, and d may contribute to this goal).
(b) A reduction in the numbers of marine mammals (total number or
number at biologically important time or location) exposed to received
levels of MFAS/HFAS, underwater detonations, or other activities
expected to result in the take of marine mammals (this goal may
contribute to a, above, or to reducing harassment takes only).
(c) A reduction in the number of times (total number or number at
biologically important time or location) individuals would be exposed
to received levels of MFAS/HFAS, underwater detonations, or other
activities expected to result in the take of marine mammals (this goal
may contribute to a, above, or to reducing harassment takes only).
(d) A reduction in the intensity of exposures (either total number
or number at biologically important time or location) to received
levels of MFAS/HFAS, underwater detonations, or other activities
expected to result in the take of marine mammals (this goal may
contribute to a, above, or to reducing the severity of harassment takes
only).
(e) A reduction in adverse effects to marine mammal habitat, paying
special attention to the food base, activities that block or limit
passage to or from biologically important areas, permanent destruction
of habitat, or temporary destruction/disturbance of habitat during a
biologically important time.
(f) For monitoring directly related to mitigation--an increase in
the probability of detecting marine mammals, thus allowing for more
effective implementation of the mitigation (shut-down zone, etc.).
NMFS and the Navy had extensive discussions regarding mitigation,
in which we explored several mitigation options and their respective
practicability (these alternatives and their practicability are
analyzed in NMFS' Draft Environmental Assessment of the Mitigation
Measures to be used in the Issuance of the HRC LOA). Ultimately, NMFS
and the Navy developed two additional measures (below), a humpback
whale cautionary area and a Stranding Response Plan, which we believe
support (or contribute to) the goals mentioned in a-e above. These
measures are described below.
[[Page 35539]]
Humpback Whale Cautionary Area
Humpback whales migrate to the Hawaiian Islands each winter to rear
their calves and mate. Data indicate that, historically, humpbacks have
clearly concentrated in high densities in certain areas around the
Hawaiian Islands. NMFS has reviewed the Navy's data on MFA sonar
training in these dense humpback areas since June 2006 and found it to
be rare and infrequent. While past data is no guarantee of future
activity, it documents a history of low level MFA sonar activity in
dense humpback areas. In order to be successful at operational missions
and against the threat of quiet, diesel-electric submarines, the Navy
has, for more than 40 years, routinely conducted anti-submarine warfare
(ASW) training in major exercises in the waters off the Hawaiian
Islands, including the Humpback Whale National Marine Sanctuary. During
this period, no reported cases of harmful effects to humpback whales
attributed to MFA sonar use have occurred. Coincident with this use of
MFA sonar, abundance estimates reflect an annual increase in the
humpback whales migrating to Hawaii (Mobely, 2001, 2004).
NMFS and the Navy explored ways of affecting the least practicable
impact (which includes a consideration of practicality of
implementation and impacts to training fidelity) to humpbacks from
exposure to MFA sonar. Proficiency in ASW requires that sailors gain
and maintain expert skills and experience in operating MFA sonar in
myriad marine environments. Exclusion zones or restricted areas are
impracticable and adversely impact MFA sonar training fidelity. The
Hawaiian Islands, including areas in which humpback whales concentrate,
contain unique bathymetric features the Navy needs to ensure sailors
gain critical skills and experience by training in littoral waters.
Sound propagates differently in shallow water. No two shallow water
areas are the same. Each shallow water area provides a unique training
experience that could be critical to address specific future training
and assessment requirements. Given the finite littoral areas in the
Hawaiian Islands area, maintaining the possibility of using all shallow
water training areas is required to ensure sailors receive the
necessary training to develop and maintain critical MFA sonar skills.
In real world events, crew members will be working in these types of
areas and these are the types of areas where the adversary's quiet
diesel-electric submarines will be operating. Without the critical ASW
training in a variety of different near-shore environments, crews will
not have the skills and varied experience needed to successfully
operate MFA sonar in these types of waters, negatively affecting vital
military readiness.
The Navy recognizes the significance of the Hawaiian Islands for
humpback whales. The Navy has designated a humpback whale cautionary
area (described below), which consists of a 5-km buffer zone around an
area that has been identified as having one of the highest
concentrations of humpback whales during the critical winter months.
The Navy has agreed that training exercises in the humpback whale
cautionary area will require a much higher level of clearance than is
normal practice in planning and conducting MFA sonar training. Should
national security needs require MFA sonar training and testing in the
cautionary area between December 15 and April 15, it shall be
personally authorized by the Commander, U.S. Pacific Fleet (CPF). The
CPF shall base such authorization on the unique characteristics of the
area from a military readiness perspective, taking into account the
importance of the area for humpback whales and the need to minimize
adverse impacts on humpback whales from MFA sonar whenever practicable.
Approval at this level for this type of activity is extraordinary. CPF
is a four-star Admiral and the highest ranking officer in the United
States Pacific Fleet. This case-by-case authorization cannot be
delegated and represents the Navy's commitment to fully consider and
balance mission requirements with environmental stewardship. Further,
CPF will provide specific direction on required mitigation prior to
operational units transiting to and training in the cautionary area.
This process will ensure the decisions to train in this area are made
at the highest level in the Pacific Fleet, heighten awareness of
humpback activities in the cautionary area, and serve to reemphasize
that mitigation measures are to be scrupulously followed. The Navy will
provide NMFS with advance notification of any such activities.
Stranding Response Plan for Major Navy Training Exercises in the HRC
NMFS and the Navy have developed a draft Stranding Response Plan
for Major Exercises in the HRC (available at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm). Pursuant to 50 CFR Section 216.105, the
plan will be included as part of (attached to) the Navy's MMPA Letter
of Authorization (LOA), which indicates the conditions under which the
Navy is authorized to take marine mammals pursuant to training
activities involving MFAS or explosives in the Hawaii Range Complex
(HRC). The Stranding Response plan is specifically intended to outline
the applicable requirements the authorization is conditioned upon in
the event that a marine mammal stranding is reported in the Hawaii
Range Complex (HRC) during a major training exercise (MTE) (see
glossary below). As mentioned above, NMFS considers all plausible
causes within the course of a stranding investigation and this plan in
no way presumes that any strandings in the HRC are related to, or
caused by, Navy training activities, absent a determination made in a
Phase 2 Investigation as outlined in Paragraph 7 of this plan,
indicating that MFAS or explosive detonation in the HRC were a cause of
the stranding. This plan is designed to address the following three
issues:
Mitigation--When marine mammals are in a situation that
can be defined as a stranding (see glossary of plan), they are
experiencing physiological stress. When animals are stranded, and
alive, NMFS believes that exposing these compromised animals to
additional known stressors would likely exacerbate the animal's
distress and could potentially cause its death. Regardless of the
factor(s) that may have initially contributed to the stranding, it is
NMFS' goal to avoid exposing these animals to further stressors.
Therefore, when live stranded cetaceans are in the water and engaged in
what is classified as an Uncommon Stranding Event (USE) (see glossary
of plan), the shutdown component of this plan is intended to minimize
the exposure of those animals to MFAS and explosive detonations,
regardless of whether or not these activities may have initially played
a role in the event.
Monitoring--This plan will enhance the understanding of
how MFAS or explosive detonations (as well as other environmental
conditions) may, or may not, be associated with marine mammal injury or
strandings. Additionally, information gained from the investigations
associated with this plan may be used in the adaptive management of
mitigation or monitoring measures in subsequent LOAs, if appropriate.
Compliance--The information gathered pursuant to this
protocol will inform NMFS' decisions regarding compliance with Sections
101(a)(5)(B and C) of the MMPA.
The Stranding Response Plan has several components:
Shutdown Procedures--When an uncommon stranding event (USE--
[[Page 35540]]
defined in the plan) occurs during a major exercise in the HRC, and a
live cetacean(s) is in the water exhibiting indicators of distress
(defined in the plan), NMFS will advise the Navy that they should cease
MFAS/HFAS operation and explosive detonations within 14 nm (26 km) of
the live animal involved in the USE (NMFS and Navy will maintain a
dialogue, as needed, regarding the identification of the USE and the
potential need to implement shutdown procedures). This distance (14 nm)
(26 km) is the distance at which sound from the sonar source is
anticipated to attenuate to approximately 140-145 dB (SPL). The risk
function predicts that less than 1 percent of the animals exposed to
sonar at this level (mysticete or odontocete) would respond in a manner
that NMFS considers Level B Harassment.
Memorandum of Agreement (MOA)--The Navy and NMFS will develop an
MOA, or other mechanism consistent with federal fiscal law requirements
(and all other applicable laws), that allows the Navy to assist NMFS
with the Phase 1 and 2 Investigations of USEs through the provision of
in-kind services, such as (but not limited to) the use of plane/boat/
truck for transport of stranding responders or animals, use of Navy
property for necropsies or burial, or assistance with aerial surveys to
discern the extent of a USE. The Navy may assist NMFS with the
Investigations by providing one or more of the in-kind services
outlined in the MOA, when available and logistically feasible and when
the provision does not negatively affect Fleet operational commitments.
Communication Protocol--Effective communication is critical to the
successful implementation of this Stranding Response Plan. Very
specific protocols for communication, including identification of the
Navy personnel authorized to implement a shutdown and the NMFS
personnel authorized to advise the Navy of the need to implement
shutdown procedures (NMFS Protected Resources HQ--senior
administrators) and the associated phone trees, etc. are currently in
development and will be refined and finalized for the Stranding
Response Plan prior to the issuance of a final rule (and updated
yearly).
Stranding Investigation--The Stranding Response Plan also outlines
the way that NMFS intends to investigate any strandings that occur
during major training exercises in the HRC.
Mitigation Conclusions
NMFS believes that the range clearance procedures and shutdown/
safety zone/exclusion zone measures the Navy has proposed will enable
the Navy to avoid injuring any marine mammals and will enable them to
minimize the numbers of marine mammals exposed to levels associated
with TTS for the following reasons:
MFAS/HFAS
The Navy's standard protective measures indicate that they will
ensure powerdown MFAS/HFAS 6 dB when a marine mammal is detected within
1000 yd (.914 km), powerdown 4 more dB (or 10 dB total) when a marine
mammal is detected within 500 yd (.457 km), and cease MFAS/HFAS
transmissions when a marine mammal is detected within 200 yd (.183 km).
PTS/Injury--NMFS believes that the proposed mitigation measures
will allow the Navy to avoid exposing marine mammals to received levels
of MFAS/HFAS sound that would result in injury for the following
reasons:
The estimated distance from the source at which an animal
would receive a level of 215 dB SEL (threshold for PTS/injury/Level A
Harassment) is approximately 10 m (10.9 yd).
NMFS believes that the probability that a marine mammal
would approach within 10 m (10.9 yd) of the sonar dome (to the sides or
below) without being seen by the watchstanders (who would then activate
a shutdown if the animal was within 200 yd (183 m) is very low,
especially considering that the model did not predict any animals (see
Table 15) would be exposed to a 215 dB SEL of MFAS/HFAS and animals
would likely avoid approaching a source transmitting at that level at
that distance.
TTS--NMFS believes that the proposed mitigation measures will allow
the Navy to minimize exposure of marine mammals to received levels of
MFAS/HFAS sound associated with TTS for the following reasons:
The estimated range of distances from the source at which
an animal would receive 195 dB SEL (the TTS threshold) is from 110-165
m (120-180 yd) from the source.
Based on the size of the animals, average group size,
behavior, and average dive time, NMFS believes that the probability
that Navy watchstanders will visually detect mysticetes or sperm
whales, dolphins, and social pelagic species (pilot whales, melon-
headed whales, etc.) at some point within the 1000 yd (.914 km) safety
zone before they are exposed to the TTS threshold levels is high, which
means that the Navy would be able to shutdown or powerdown to avoid
exposing these species to levels associated with TTS.
However, more cryptic, deep-diving species (beaked whales
and Kogia sp.) are less likely to be visually detected and could
potentially be exposed to levels of MFAS/HFAS expected to cause TTS.
Additionally, the Navy's bow-riding mitigation exception for dolphins
may sometimes allow dolphins to be exposed to levels of MFAS/HFAS
likely to result in TTS.
Underwater Explosives
The Navy utilizes exclusion zones (wherein explosive detonation
will not begin/continue if animals are within the zone) for explosive
exercises. Table 8 indicates the various explosives, the estimated
distance at which animals will receive levels associated with take (see
Acoustic Take Criteria Section), and the exclusion zone associated with
the explosive types.
Mortality and Injury--NMFS believes that the mitigation measures
will allow the Navy to avoid exposing marine mammals to underwater
detonations that would result in injury or mortality for the following
reasons:
Surveillance for large charges (which includes aerial and
passive acoustic detection methods, when available, to ensure
clearance) begins two hours before the exercise and extends to 2 nm
(3704 m) from the source.
Animals would need to be within less than 1023 m (1118 yd)
(large explosives) or 305 m (334 yd) (smaller charges) from the source
to be injured.
Unlike for sonar, an animal would need to be present at
the exact moment of the explosion(s) (except for the short series of
gunfire example in GUNEX) to be taken.
The model predicted only 3 animals would be exposed to
levels associated with injury (though for the reasons above, NMFS does
not believe they will be exposed) to those levels).
When the implementation of the exclusion zones (i.e., not
starting or continuing to detonate explosives if an animal is detected
within the exclusion zone) is combined with the above bullets, NMFS
believes that the Navy's mitigation will be effective for avoiding
injury and mortality to marine mammals from explosives.
TTS--NMFS believes that the proposed mitigation measures will allow
the Navy to minimize the exposure of marine mammals to underwater
detonations that would result in TTS for the following reasons:
[[Page 35541]]
Very few animals were predicted to be exposed to explosive
levels that would result in TTS--and for the reasons above, NMFS
believes that most modeled TTS takes can be avoided, especially
dolphins, mysticetes and sperm whales, and social pelagic species.
However, more cryptic, deep-diving species (beaked whales
and Kogia sp.) are less likely to be visually detected and could
potentially be exposed to explosive levels expected to cause TTS.
Additionally, for two of the explosive types (MK-84 and
MK-48), though the distance to the presuure threshold is within the
exclusion zone, the distance at which an animal would be expected to
receive SEL levels associated with TTS (182 dB SEL) is larger than the
exclusion zone, which means that for those two explosive types, any
species could potentially be exposed to levels associated with TTS if
it was detected in the limited area outside of the exclusion zone, but
inside the distance to 182 dB SEL.
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The Stranding Response Plan will minimize the probability of
distressed live-stranded animals responding to the proximity of sonar
in a manner that further stresses them or increases the potential
likelihood of mortality. The Humpback Whale Cautionary Area is intended
to reduce the number and intensity of potential humpback exposures to
MFAS/HFAS.
NMFS has preliminarily determined that the Navy's proposed
mitigation measures (from the LOA application), along with the Humpback
Whale Cautionary Area and the Stranding Response Plan (and when the
Adaptive Management (see Adaptive Management below) component is taken
into consideration) are adequate means of effecting the least
practicable adverse impacts on marine mammals species or stocks and
their habitat, paying particular attention to rookeries, mating
grounds, and areas of similar significance, while also considering
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity.
These mitigation measures may be refined, modified, removed, or
added to prior to the issuance of the final rule based on the comments
and information received during the public comment period.
Research and Conservation Measures for Marine Mammals
The Navy is working towards a better understanding of marine
mammals and sound in ways that are not directly related to the MMPA
process. The Navy highlights some of those ways in the section below.
Further, NMFS is working on a long-term stranding study that will be
supported by the Navy by way of a funding and information sharing
component (see below).
Navy's Conservation Measures
The Navy will continue to fund ongoing marine mammal research in
the Hawaiian Islands. Results of conservation efforts by the Navy in
other locations will also be used to support efforts in the Hawaiian
Islands. The Navy is coordinating both short and long term monitoring/
studies of marine mammals on various established ranges and operating
areas to determine the response of marine mammals to Navy sound sources
and the effectiveness of mitigation measures:
Coordinating with NMFS to conduct surveys within the
selected Hawaiian Islands Operating Area as part of a baseline
monitoring program.
Implementing a long-term monitoring program of marine
mammal populations in the Hawaiian Islands Operating Area, including
evaluation of trends.
Implementing a marine mammal monitoring program in the HRC
during training exercises.
Continuing Navy research and Navy contribution to
university/external research to improve the state of the science
regarding marine species biology and acoustic effects.
Sharing data with NMFS and via the literature for research
and development efforts.
Long-Term Prospective Study
Apart from this proposed rule, NMFS, with input and assistance from
the Navy and several other agencies and entities, will perform a
longitudinal observational study of marine mammal strandings to
systematically observe for and record the types of pathologies and
diseases and investigate the relationship with potential causal factors
(e.g., sonar, seismic, weather). The study will not be a true
``cohort'' study, because we will be unable to quantify or estimate
specific sonar or other sound exposures for individual animals that
strand. However, a cross-sectional or correlational analyses, a method
of descriptive rather than analytical epidemiology, can be conducted to
compare population characteristics, e.g., frequency of strandings and
types of specific pathologies between general periods of various
anthropogenic activities and non-activities within a prescribed
geographic space. In the long term study, we will more fully and
consistently collect and analyze data on the demographics of strandings
in specific locations and consider anthropogenic activities and
physical,
[[Page 35542]]
chemical, and biological environmental parameters. This approach in
conjunction with true cohort studies (tagging animals, measuring
received sounds, and evaluating behavior or injuries) in the presence
of activities and non-activities will provide critical information
needed to further define the impacts of MTEs and other anthropogenic
and non-anthropogenic stressors. In coordination with the Navy and
other federal and non-federal partners, the comparative study will be
designed and conducted for specific sites during intervals of the
presence of anthropogenic activities such as sonar transmission or
other sound exposures and absence to evaluate demographics of morbidity
and mortality, lesions found, and cause of death or stranding.
Additional data that will be collected and analyzed in an effort to
control potential confounding factors include variables such as average
sea temperature (or just season), meteorological or other environmental
variables (e.g., seismic activity), fishing activities, etc. All
efforts will be made to include appropriate controls (i.e., no sonar or
no seismic); environmental variables may complicate the interpretation
of ``control'' measurements. The Navy and NMFS along with other
partners are evaluating mechanisms for funding this study.
Monitoring
In order to issue an ITA for an activity, Section 101(a)(5)(A) of
the MMPA states that NMFS must set forth ``requirements pertaining to
the monitoring and reporting of such taking''. The MMPA implementing
regulations at 50 CFR Section 216.104(a)(13) indicate that requests for
LOAs must include the suggested means of accomplishing the necessary
monitoring and reporting that will result in increased knowledge of the
species and of the level of taking or impacts on populations of marine
mammals that are expected to be present.
Monitoring measures prescribed by NMFS should accomplish one or
more of the following general goals:
(a) An increase in the probability of detecting marine mammals,
both within the safety zone (thus allowing for more effective
implementation of the mitigation) and in general to generate more data
to contribute to the analyses mentioned below.
(b) An increase in our understanding of how many marine mammals are
likely to be exposed to levels of MFAS (or explosives or other stimuli)
that we associate with specific adverse effects, such as behavioral
harassment, TTS, or PTS.
(c) An increase in our understanding of how marine mammals respond
to MFAS (at specific received levels), explosives, or other stimuli
expected to result in take and how anticipated adverse effects on
individuals (in different ways and to varying degrees) may impact the
population, species, or stock (specifically through effects on annual
rates of recruitment or survival) through any of the following methods:
Behavioral observations in the presence of MFAS compared
to observations in the absence of sonar (need to be able to accurately
predict received level and report bathymetric conditions, distance from
source, and other pertinent information.
Physiological measurements in the presence of MFAS
compared to observations in the absence of sonar (need to be able to
accurately predict received level and report bathymetric conditions,
distance from source, and other pertinent information), and/or
Pre-planned and thorough investigation of stranding events
that occur coincident to naval activities.
Distribution and/or abundance comparisons in times or
areas with concentrated MFAS versus times or areas without MFAS.
(d) An increased knowledge of the effected species.
(e) An increase in our understanding of the effectiveness of
certain mitigation and monitoring measures.
Proposed Monitoring Plan for the HRC
The Navy has submitted a draft Monitoring Plan for the HRC, which
may be viewed at NMFS' Web site: http://www.nmfs.noaa.gov/pr/permits/incidental.htm. NMFS and the Navy have worked together on the
development of this plan in the months preceding the publication of
this proposed rule; however, we are still refining the plan and
anticipate that it will contain more details by the time it is
finalized in advance of the issuance of the final rule. Additionally,
the plan may be modified or supplemented based on comments or new
information received from the public during the public comment period.
A summary of the primary components of the plan follows.
The draft Monitoring Plan for the HRC has been designed as a
collection of focused ``studies'' (described fully in the HRC
Monitoring Plan) to gather data that will allow the Navy to address the
following questions:
(a) Are marine mammals exposed to mid-frequency active sonar
(MFAS), especially at levels associated with adverse effects (i.e.,
based on NMFS'criteria for behavioral harassment, TTS, or PTS)? If so,
at what levels are they exposed?
(b) If marine mammals are exposed to MFAS in the HRC, do they
redistribute geographically as a result of continued exposure? If so,
how long does the redistribution last?
(c) If marine mammals are exposed to MFAS, what are their
behavioral responses to various levels?
(d) What are the behavioral responses of marine mammals that are
exposed to explosives at specific levels?
(e) Is the Navy's suite of mitigation measures for MFAS and
explosives (e.g., PMAP, major exercise measures agreed to by the Navy
through permitting) effective at avoiding TTS, injury, and mortality of
marine mammals?
Data gathered in these studies will be collected by qualified,
professional marine mammal biologists that are experts in their field.
They will use a combination of the following methods to collect data:
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[[Page 35544]]
In addition to the Monitoring Plan for the HRC, by the end of 2009,
the Navy will have completed an Integrated Comprehensive Monitoring
Program (ICMP). The ICMP will provide the overarching structure and
coordination that will, over time, compile data from both range
specific monitoring plans (such as HRC, the Atlantic Fleet Active Sonar
Training Range (AFAST), or the Southern California Range Complex) as
well as Navy funded research and development (R&D) studies. The primary
objectives of the ICMP are:
To monitor Navy training events, particularly those
involving mid-frequency sonar and underwater detonations, for
compliance with the terms and conditions of ESA Section 7 consultations
or MMPA authorizations;
To collect data to support estimating the number of
individuals exposed to sound levels above current regulatory
thresholds;
To assess the efficacy of the Navy's current marine
species mitigation;
To add to the knowledgebase on potential behavioral and
physiological effects to marine species from mid-frequency active sonar
and underwater detonations; and,
To assess the practicality and effectiveness of a number
of mitigation tools and techniques (some not yet in use).
More information about the ICMP may be found in the draft
Monitoring Plan for the HRC.
Past Monitoring in the HRC
Since RIMPAC 2006, which was the first Navy training activity
utilizing MFAS to receive an MMPA authorization and an incidental take
statement pursuant to the ESA, NMFS has received four monitoring
reports (one covering two exercises) addressing MFAS use in the HRC,
including the RIMPAC after action report (AAR). The Navy's AARs may be
viewed at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm. For
three of the exercises, the reports describe observations by the
watchstanders (who are involved in the training exercise) only. For two
of the exercises (RIMPAC and the most recent USWEX), independent marine
mammal observers were used to collect data before, during, and after
the exercises. NMFS has reviewed these reports and has summarized the
results, as related to marine mammal observations, below.
RIMPAC 2006
During the RIMPAC exercises in July 2006, the Navy operated MFAS
hull-mounted sonar for 472 hours. They operated active sonobuoys for
115 hours and helicopter dipping sonar for 110 hours, however, these
sources do not ping continuously and put far less sound in the water
per hour than hull-mounted sonar. A map in the AAR showing the
locations of the marine mammal sightings indicates that the exercises
covered a very large area, both to the north and south of the islands,
with the majority of the sightings of marine mammals occurring in the
open ocean (not near shore).
Observations by Exercise Participants--Table 10 summarizes the
marine mammals sighted by exercise participants and whether or not
sonar was shut down. The Navy indicates in its report that no evidence
of behavioral effects was observed.
[[Page 35545]]
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Observations by Marine Mammal Observers--The Navy contracted marine
mammal observers to conduct aerial surveys, and their summary and
conclusions of the monitoring are described here. A total of six aerial
surveys of marine mammals were performed on dates corresponding with
scheduled dates for ``choke point'' maneuvers of the RIMPAC exercises.
Three surveys were performed in the vicinity of the Kaulakahi Channel
(between Kauai and Niihau) (July 16, 17 and 20) and three were
performed in the Alenuihaha Channel (between Hawaii and Maui) (July 24-
26). The mission of the surveys was to detect, locate and identify all
marine mammal species in the target areas using methods consistent with
modern distance sampling theory. Marine mammals were sighted on four of
the six surveys, comprising a total of 13 groups. All sightings
consisted of small- to medium-sized odontocetes (toothed cetaceans),
including one sighting each of bottlenose dolphins, spotted dolphins,
Cuvier's beaked whale, false killer whale, unidentified beaked whale
and eight sightings of unidentified delphinid species. Encounter rates
of odontocete sightings (sightings/km surveyed) in this series were
identical to those seen during earlier survey series (1993-03), though
at different times of the year. No unusual observations (e.g.,
sightings of unusual behavior or aggregations, near strandings, or
stranded or dead animals) were noted during the total of approximately
18 hrs. of survey effort.
USWEX 06-04
During this three-day exercise, which was conducted from September
19-21, 2006 and in which the hours of sonar use were not reported, no
marine mammals were sighted by the exercise participants.
USWEX 07-02
This exercise was conducted from April 10-11, 2007 and involved 5
MFAS-equipped ships, one non-MFAS equipped ship, and 8-12 helicopters.
Other participating units representing support and opposition forces,
which did not utilize sonar, included 2 submarines and 3 MFA-equipped
ships. During the exercise, 265.5 hours of sonar use were reported.
No marine mammals were sighted by the participants during the
exercise.
USWEX 07-03
This exercise was conducted from April 17-18, 2007, and involved 3
MFAS-equipped ships, 3 non-MFAS equipped ships, and 6 helicopters.
Other participating units representing support and opposition forces,
which did not utilize sonar, included 2 submarines and 2 MFA-equipped
ships. During this exercise 50.1 hours of sonar use were reported.
One large whale was sighted by Navy watchstanders at a distance of
approximately 300 yds when MFAS was not operating.
[[Page 35546]]
USWEX 08-1
USWEX 08-1 was conducted from November 13-15, 2007, and involved 3
MFAS-equipped ships, several other non-MFAS-equipped ships, and 2-4
helicopters with dipping sonar. During the exercise, a total of 77
hours of MFAS time was reported from all sources, including hull-
mounted, helicopter dipping, and DICASS sonobuoys. The exercise was
primarily conducted to the Northeast (extending far out to sea) of Oahu
(a map is available in the AAR).
Observations by Exercise Participants
There were no sightings of marine mammals within 2000 yds by Navy
personnel engaged in the training during USWEX 08-01. Sea states were
high during some of the exercise period, which may have limited
sightings of smaller marine mammals.
Observations of Marine Mammal Observers
Aerial Survey
A pre- and post-exercise aerial survey was conducted by a civilian
science crew from 1 to 12 November and 15 to 17 November. The purpose
of these surveys was to detect, locate, and identify all marine mammals
and sea turtles observed within a 2384 mi\2\ (6175 km\2\) grid (to the
east and northeast of Oahu); and during circumnavigation of the islands
of Oahu and Molokai. Over 17 hours of survey time was conducted,
involving a linear distance of approximately 1,701 nm (3150 km). There
were 26 marine mammal sightings (six at sea with the remaining 20
observed nearshore), including short-finned pilot whales, Hawaiian
spinner dolphins, bottlenose dolphins, Hawaiian monk seals, and three
unidentified species (Stenella sp., dolphin and baleen whale) (see
Table 11). Time was spent characterizing behavior at the time of the
sightings and no indications of distressed or unusual behavior were
documented. Additionally, there were no observations of any stranded or
floating dead marine mammals. More information regarding the findings
of these aerial surveys may be found in Appendix B of the USWEX 08-01
Monitoring report, which is posted on the NMFS Web site, at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm.
[GRAPHIC] [TIFF OMITTED] TP23JN08.013
Vessel Survey
A civilian science-based research vessel conducted a visual
monitoring survey for cetaceans and sea turtles from November 11-17,
2007. The purpose of these surveys was to monitor, identify, and report
surface behavior of marine mammals observed before, during, and after
the scheduled training exercise; particularly any injured or harmed
marine mammals and/or unusual behavior or changes in behavior,
distribution and numbers of animals. Another goal was to attempt to
remain within view of any opportunistically encountered Navy vessels
while conducting surveys and focal follows sessions. The effort was
focused in the same designated survey box as the aerial survey team, to
the east and northeast of Oahu. A total of 66 hours and approximately
911 km (492 nm) were visually surveyed over seven days with a total of
eight cetacean groups sighted. Line surveys were conducted over 817 km
(441 nm) (with 105 km (57 nm) while Navy vessels were within view) and
animals were focally followed for a total of approximately 63 km (34
nm). None of the whales followed during the focal sessions exhibited
any notable evasive or disturbance behavior related to the observation
vessel or as defined under the MMPA. No injured or dead whales were
detected.
A summary of the marine mammals sighted and their associated
behaviors (including those that occurred during four focal follows) is
presented in Table 12. The observers documented the first occurrence of
Bryde's whale near the main Hawaiian islands, previous verified
sightings have only occurred in the leeward Northwestern chain of the
Hawaiian Islands. A Navy vessel was operating MFAS at approximately the
same time as the Bryde's whale focal follow, at approximately 50 nm (93
km) away. Post exercise modeling predicted that the Bryde's whale may
have been exposed to received levels of up to 141dB (SPL), though, as
mentioned previously, no unusual behaviors were observed.
The vessel survey report, which is included in Appendix C of the
Navy's AAR, and available at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm, draws some conclusions regarding the efficacy of
certain monitoring techniques and makes recommendations for future
monitoring plans. The Navy has taken this information into
consideration in developing the monitoring plan for the HRC that is
proposed here.
[[Page 35547]]
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BILLING CODE 3510-22-C
General Conclusions Drawn From Review of Monitoring Reports
Because NMFS has received relatively few monitoring reports from
sonar training in the HRC, and even fewer that have utilized
independent aerial or vessel-based observers, it is too early to draw
any biological conclusions. However, NFMS can draw some general
conclusions from the content of the monitoring reports:
(a) The data gathered by independent observers contains far more
detail than the data gathered by watchstanders. Data from watchstanders
is generally useful to indicate the presence or absence of marine
mammals within the safety zones (and sometimes without) and to document
the implementation of mitigation measures, but does not provide useful
species' specific information or behavioral data. Data gathered by
independent observers can provide very valuable information at a level
of detail not possible with watchstanders, such as the presence of sub-
adult sei whales in the Hawaiian islands in fall, potentially
indicating the use of the area for breeding.
(b) More marine mammal sightings per hour of effort were reported
by independent observers than by Navy watchstanders. Out of
approximately 1100 hours of sonar operation, the Navy watchstanders
reported 30 sightings of marine mammals. Out of approximately 100 hours
of observation, the independent observers reported 47 sightings of
marine mammals (if the observations and hours that were specifically
near shore or in channels are removed (likely higher density of marine
mammals), the independent observers had 14 sightings in 80 hours of
effort: 6 sightings in 14 hours of aerial and 8 sightings in 66 hours
of vessel-based). There are a couple of possible explanations for this:
(i) MFAS was likely operating in much closer proximity to and for a
significantly larger percentage of the time when watchstanders were
reporting marine mammal sightings as compared to when independent
observers were reporting them. Marine mammals may have been avoiding
the sonar source and therefore been present in lower numbers
immediately around the watchstanders (usually on the same platform as
the sonar source itself), or within the distance that the watchstanders
could easily detect them. Alternatively, MFAS was not necessarily
operating in the immediate vicinity of the independent observers, and
even when so, the source was at least a few miles away.
(ii) Because of their experience and training, independent vessel-
based marine mammal observers may see a higher percentage of the
animals at the surface than the Navy watchstanders (0.12 sightings/hour
versus 0.03 sightings/hour, respectively).
(c) Though it is by no means conclusory, it is worth noting that no
instances of obvious behavioral disturbance were observed either by the
Navy watchstanders or the independent observers (and a portion of the
independent observations were reported within the vicinity of operating
MFAS)
[[Page 35548]]
in the 1200+ hours of effort in which 77 sightings of marine mammals
were made. Though of course, these observations only cover the animals
that were at the surface (or slightly below in the case of aerial
surveys) and within the distance that the observers can see with the
big-eye binoculars or from the aircraft.
(d) NMFS and the Navy need to more carefully designate what
information should be gathered during monitoring, as some reports
contain different information, making cross-report comparisons
difficult. For example, some reports indicate marine mammals seen
within the safety zones, while others indicate marine mammals detected
within any distance.
Adaptive Management
Adaptive Management was addressed above in the context of the
Stranding Response Plan because that Section will be a stand-alone
document. More specifically, the final regulations governing the take
of marine mammals incidental to Navy training exercises in the HRC will
contain an adaptive management component. Our understanding of the
effects of MFAS/HFAS on marine mammals is still in its relative
infancy, and yet the science in this field is evolving fairly quickly.
These circumstances make the inclusion of an adaptive management
component both valuable and necessary within the context of 5-year
regulations for activities that have been associated with marine mammal
mortality in certain circumstances and locations (though not the HRC).
The use of adaptive management will give NMFS the ability to consider
new data from different sources to determine (in coordination with the
Navy), on an annual basis if new or modified mitigation or monitoring
measures are appropriate for subsequent annual LOAs. Following are some
of the possible sources of applicable data:
Results from the Navy's monitoring from the previous year
(either from the HRC or other locations).
Results from specific stranding investigations (either
from the HRC or other locations, and involving coincident MFAS training
or not involving coincident use).
Results from the Long Term Prospective Study described
below.
Results from general marine mammal and sound research
(funded by the Navy (described below) or otherwise).
Mitigation measures could be modified or added if new data suggests
that such modifications would have a reasonable likelihood of reducing
adverse effects to marine mammals and if the measures were practicable.
NMFS could also coordinate with the Navy to modify or add to the
existing monitoring requirements if the new data suggest that the
addition of a particular measure would likely fill in a specifically
important data gap.
Reporting
In order to issue an ITA for an activity, Section 101(a)(5)(A) of
the MMPA states that NMFS must set forth ``requirements pertaining to
the monitoring and reporting of such taking''. Effective reporting is
critical both to compliance as well as ensuring that the most value is
obtained from the required monitoring. Some of the reporting
requirements are still in development and the final rule may contain
additional details not contained in the proposed rule. Additionally,
proposed reporting requirements may be modified, removed, or added
based on information or comments received during the public comment
period. Currently, there are several different reporting requirements
pursuant to these proposed regulations:
General Notification of Injured or Dead Marine Mammals
Navy personnel will ensure that NMFS (regional stranding
coordinator) is notified immediately (or as soon as clearance
procedures allow) if an injured or dead marine mammal is found during
or shortly after, and in the vicinity of, any Navy training exercise
utilizing MFAS, HFAS, or underwater explosive detonations. The Navy
will provide NMFS with species or description of the animal (s), the
condition of the animal(s) (including carcass condition if the animal
is dead), location, time of first discovery, observed behaviors (if
alive), and photo or video (if available). The Stranding Response Plan
contains more specific reporting requirements for specific
circumstances.
SINKEX, GUNEX, MISSILEX, BOMBEX, and IEER
A yearly report detailing the exercise's timeline, the time the
surveys commenced and terminated, amount, and types of all ordnance
expended, and the results of survey efforts for each event will be
submitted to NMFS.
MFAS Mitigation/Navy Watchstanders
The Navy will submit an After Action Report to the Office of
Protected Resources, NMFS, within 120 days of the completion of a Major
Training Exercise (RIMPAC, USWEX, and Multi Strike Group). For other
ASW exercises (TRACKEX and TORPEX), the Navy will submit a yearly
summary report. These reports will, at a minimum, include the following
information:
The estimated number of hours of sonar operation, broken
down by source type.
If possible, the total number of hours of observation
effort (including observation time when sonar was not operating).
A report of all marine mammal sightings (at any distance--
not just within a particular distance) to include, when possible and to
the best of their ability, and if not classified:
[cir] Species.
[cir] Number of animals sighted.
[cir] Location of marine mammal sighting.
[cir] Distance of animal from any operating sonar sources.
[cir] Whether animal is fore, aft, port, starboard.
[cir] Direction animal is moving in relation to source (away,
towards, parallel).
[cir] Any observed behaviors of marine mammals.
The status of any sonar sources (what sources were in use)
and whether or not they were powered down or shut down as a result of
the marine mammal observation.
The platform that the marine mammals were sighted from.
Monitoring Report
Although the draft Monitoring Plan for the HRC contains a general
description of the monitoring that the Navy plans to conduct (and that
NMFS has analyzed) in the HRC, the detailed analysis and reporting
protocols that will be used for the Hawaii monitoring plan are still
being refined at this time. The draft HRC Monitoring plan may be viewed
at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm. Standard marine
species sighting forms will be used by Navy lookouts and biologists to
standardize data collection and data collection methods will be
standardized across ranges to allow for comparison in different
geographic locations. Reports of the required monitoring will be
submitted to NMFS on an annual basis as well as in the form of a multi-
year report that compiles all five years worth of monitoring data
(reported at end of fourth year of rule--in future rules will include
the last year of the prior rule).
HRC Comprehensive Report
The Navy will submit to NMFS a draft report that analyzes and
summarizes all of the multi-year marine mammal information gathered
during ASW and explosive exercises for which individual
[[Page 35549]]
reports are required in Sec. 216.175 (d-f). This report will be
submitted at the end of the fourth year of the rule (November 2012),
covering activities that have occurred through June 1, 2012. The Navy
will respond to NMFS comments on the draft comprehensive report if
submitted within 3 months of receipt. The report will be considered
final after the Navy has addressed NMFS' comments, or three months
after the submittal of the draft if NMFS does not comment by then.
Comprehensive National ASW Report
The Navy will submit a draft Comprehensive National ASW Report that
analyzes, compares, and summarizes the data gathered from the
watchstanders and pursuant to the implementation of the Monitoring
Plans for the HRC, the Atlantic Fleet active Sonar Training (AFAST),
and the Southern California (SOCAL) Range Complex. The Navy will
respond to NMFS comments on the draft comprehensive report if submitted
within 3 months of receipt. The report will be considered final after
the Navy has addressed NMFS' comments, or three months after the
submittal of the draft if NMFS does not comment by then.
Estimated Take of Marine Mammals
As mentioned previously, for the purposes of MMPA authorizations,
NMFS' effects assessments have two primary purposes (in the context of
the HRC LOA, where subsistence communities are not present): (1) To put
forth the permissible methods of taking within the context of MMPA
Level B Harassment (behavioral harassment), Level A Harassment
(injury), and mortality (i.e., identify the number and types of take
that will occur); and (2) to determine whether the specified activity
will have a negligible impact on the affected species or stocks of
marine mammals (based on the likelihood that the activity will
adversely affect the species or stock through effects on annual rates
of recruitment or survival).
In the Potential Effects of Exposure of Marine Mammal to MFAS/HFAS
and Underwater Detonations section, NMFS' analysis identified the
lethal responses, physical trauma, sensory impairment (permanent and
temporary threshold shifts and acoustic masking), physiological
responses (particular stress responses), and behavioral responses that
could potentially result from exposure to MFAS/HFAS or underwater
explosive detonations. In this section, we will relate the potential
effects to marine mammals from MFAS/HFAS and underwater detonation of
explosives to the MMPA regulatory definitions of Level A and Level B
Harassment and attempt to quantify the effects that might occur from
the specific training activities that the Navy is proposing in the HRC.
Definition of Harassment
As mentioned previously, with respect to military readiness
activities, Section 3(18)(B) of the MMPA defines ``harassment'' 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].
Level B Harassment
Of the potential effects that were described in the Potential
Effects of Exposure of Marine Mammal to MFAS/HFAS and Underwater
Detonations Section, following are the types of effects that fall into
the Level B Harassment category:
Behavioral Harassment--Behavioral disturbance that rises to the
level described in the definition above, when resulting from exposures
to MFAS/HFAS or underwater detonations, is considered Level B
Harassment. Some of the lower level physiological stress responses
discussed in the Potential Effects of Exposure of Marine Mammal to
MFAS/HFAS and Underwater Detonations Section: Stress Section will also
likely co-occur with the predicted harassments, although these
responses are more difficult to detect and fewer data exist relating
these responses to specific received levels of sound. When Level B
Harassment is predicted based on estimated behavioral responses, those
takes may have a stress-related physiological component as well.
In the effects section above, we described the Southall et al.,
(2007) severity scaling system and listed some examples of the three
broad categories of behaviors: (0-3: Minor and/or brief behaviors); 4-6
(Behaviors with higher potential to affect foraging, reproduction, or
survival); 7-9 (Behaviors considered likely to affect the
aforementioned vital rates). Generally speaking, MMPA Level B
Harassment, as defined in this document, would include the behaviors
described in the 7-9 category, and a subset, dependent on context and
other considerations, of the behaviors described in the 4-6 categories.
Behavioral harassment does not include behaviors ranked 0-3 in Southall
et al., (2007).
Acoustic Masking and Communication Impairment--Acoustic masking is
considered Level B Harassment as it can disrupt natural behavioral
patterns by interrupting or limiting the marine mammal's receipt or
transmittal of important information or environmental cues.
TTS--As discussed previously, TTS can effect how an animal behaves
in response to the environment, including conspecifics, predators, and
prey. The following physiological mechanisms are thought to play a role
in inducing auditory fatigue: Effects to sensory hair cells in the
inner ear that reduce their sensitivity, modification of the chemical
environment within the sensory cells, residual muscular activity in the
middle ear, displacement of certain inner ear membranes, increased
blood flow, and post-stimulatory reduction in both efferent and sensory
neural output. Ward (1997) suggested that when these effects result in
TTS rather than PTS, they are within the normal bounds of physiological
variability and tolerance and do not represent a physical injury.
Additionally, Southall et al. (2007) indicate that although PTS is a
tissue injury, TTS is not because the reduced hearing sensitivity
following exposure to intense sound results primarily from fatigue, not
loss, of cochlear hair cells and supporting structures and is
reversible. Accordingly, NMFS classifies TTS (when resulting from
exposure to either MFAS/HFAS or underwater detonations) as Level B
Harassment, not Level A Harassment (injury).
Level A Harassment
Of the potential effects that were described in the Potential
Effects of Exposure of Marine Mammal to MFAS/HFAS and Underwater
Detonations Section, following are the types of effects that fall into
the Level A Harassment category:
PTS--PTS (resulting either from exposure to MFAS/HFAS or explosive
detonations) is irreversible and considered an injury. PTS results from
exposure to intense sounds that cause a permanent loss of inner or
outer cochlear hair cells or exceed the elastic limits of certain
tissues and membranes in the middle and inner ears and result in
changes in the chemical composition of the inner ear fluids.
Acoustically Mediated Bubble Growth--A few theories suggest ways in
which gas bubbles become enlarged through exposure to intense sounds
[[Page 35550]]
(MFAS/HFAS) to the point where tissue damage results. In rectified
diffusion, exposure to a sound field would cause bubbles to increase in
size. Alternately, bubbles could be destabilized by high-level sound
exposures such that bubble growth then occurs through static diffusion
of gas out of the tissues. Tissue damage from either of these processes
would be considered an injury.
Behaviorally Mediated Bubble Growth--Several authors suggest
mechanisms in which marine mammals could behaviorally respond to
exposure to MFAS/HFAS by altering their dive patterns in a manner
(unusually rapid ascent, unusually long series of surface dives, etc.)
that might result in unusual bubble formation or growth ultimately
resulting in tissue damage (emboli, etc.)
Physical Disruption of Tissues Resulting from Explosive Shock
Wave--Physical damage of tissues resulting from a shock wave (from an
explosive detonation) is classified as an injury. Blast effects are
greatest at the gas-liquid interface (Landsberg, 2000) and gas-
containing organs, particularly the lungs and gastrointestinal tract,
are especially susceptible (Goertner, 1982; Hill 1978; Yelverton et
al., 1973). Nasal sacs, larynx, pharynx, trachea, and lungs may be
damaged by compression/expansion caused by the oscillations of the
blast gas bubble (Reidenberg and Laitman, 2003). Severe damage (from
the shock wave) to the ears can include tympanic membrane rupture,
fracture of the ossicles, damage to the cochlea, hemorrhage, and
cerebrospinal fluid leakage into the middle ear.
Acoustic Take Criteria
For the purposes of an MMPA incidental take authorization, three
types of take are identified: Level B Harassment; Level A Harassment;
and mortality (or serious injury leading to mortality). The categories
of marine mammal responses (physiological and behavioral) that fall
into the two harassment categories were described in the previous
section.
Because the physiological and behavioral responses of the majority
of the marine mammals exposed to MFAS/HFAS and underwater detonations
cannot be detected or measured (not all responses visible external to
animal, portion of exposed animals underwater (so not visible), many
animals located many miles from observers and covering very large area,
etc.) and because NMFS must authorize take prior to the impacts to
marine mammals, a method is needed to estimate the number of
individuals that will be taken, pursuant to the MMPA, based on the
proposed action. To this end, NMFS developed acoustic criteria that
estimate at what received level (when exposed to MFAS/HFAS or explosive
detonations) Level B Harassment, Level A Harassment, and mortality (for
explosives) of marine mammals would occur. The acoustic criteria for
MFAS/HFAS and Underwater Detonations are discussed below.
MFAS/HFAS Acoustic Criteria
Because relatively few applicable data exist to support acoustic
criteria specifically for HFAS and because such a small percentage of
the sonar pings that marine mammals will likely be exposed to
incidental to this activity come from a HFAS source (the vast majority
come from MFAS sources), NMFS will apply the criteria developed for the
MFAS to the HFAS as well.
NMFS utilizes three acoustic criteria for MFAS/HFAS: PTS (injury--
Level A Harassment), TTS (Level B Harassment), and behavioral
harassment (Level B Harassment). Because the TTS and PTS criteria are
derived similarly and the PTS criteria was extrapolated from the TTS
data, the TTS and PTS acoustic criteria will be presented first, before
the behavioral criteria.
For more information regarding these criteria, please see the
Navy's FEIS for the HRC.
Level B Harassment Threshold (TTS)
As mentioned above, behavioral disturbance, acoustic masking, and
TTS are all considered Level B Harassment. Marine mammals would usually
be behaviorally disturbed at lower received levels than those at which
they would likely sustain TTS, so the levels at which behavioral
disturbance is likely to occur are considered the onset of Level B
Harassment. The behavioral responses of marine mammals to sound are
variable, context specific, and, therefore, difficult to quantify (see
Risk Function section, below). TTS is a physiological effect that has
been studied and quantified in laboratory conditions. Because data that
support an estimate of at what received levels marine mammals will TTS
exist, NMFS also uses an acoustic criteria to estimate the number of
marine mammals that might sustain TTS incidental to a specific activity
(in addition to the behavioral criteria).
A number of investigators have measured TTS in marine mammals.
These studies measured hearing thresholds in trained marine mammals
before and after exposure to intense sounds. The existing cetacean TTS
data are summarized in the following bullets.
Schlundt et al. (2000) reported the results of TTS
experiments conducted with 5 bottlenose dolphins and 2 belugas exposed
to 1-second tones. This paper also includes a reanalysis of preliminary
TTS data released in a technical report by Ridgway et al. (1997). At
frequencies of 3, 10, and 20 kHz, sound pressure levels (SPLs)
necessary to induce measurable amounts (6 dB or more) of TTS were
between 192 and 201 dB re 1 [mu]Pa (EL = 192 to 201 dB re 1 [mu]Pa2-s).
The mean exposure SPL and EL for onset-TTS were 195 dB re 1 [mu]Pa and
195 dB re 1 [mu]Pa\2\-s, respectively.
Finneran et al. (2001, 2003, 2005) described TTS
experiments conducted with bottlenose dolphins exposed to 3-kHz tones
with durations of 1, 2, 4, and 8 seconds. Small amounts of TTS (3 to 6
dB) were observed in one dolphin after exposure to ELs between 190 and
204 dB re 1 [mu]Pa\2\-s. These results were consistent with the data of
Schlundt et al. (2000) and showed that the Schlundt et al. (2000) data
were not significantly affected by the masking sound used. These
results also confirmed that, for tones with different durations, the
amount of TTS is best correlated with the exposure EL rather than the
exposure SPL.
Nachtigall et al. (2003) measured TTS in a bottlenose
dolphin exposed to octave-band sound centered at 7.5 kHz. Nachtigall et
al. (2003a) reported TTSs of about 11 dB measured 10 to 15 minutes
after exposure to 30 to 50 minutes of sound with SPL 179 dB re 1 [mu]Pa
(EL about 213 dB re [mu]Pa\2\-s). No TTS was observed after exposure to
the same sound at 165 and 171 dB re 1 [mu]Pa. Nachtigall et al. (2004)
reported TTSs of around 4 to 8 dB 5 minutes after exposure to 30 to 50
minutes of sound with SPL 160 dB re 1 [mu]Pa (EL about 193 to 195 dB re
1 [mu]Pa\2\-s). The difference in results was attributed to faster
post-exposure threshold measurement--TTS may have recovered before
being detected by Nachtigall et al. (2003). These studies showed that,
for long-duration exposures, lower sound pressures are required to
induce TTS than are required for short-duration tones.
Finneran et al. (2000, 2002) conducted TTS experiments
with dolphins and belugas exposed to impulsive sounds similar to those
produced by distant underwater explosions and seismic waterguns. These
studies showed that, for very short-duration impulsive sounds, higher
sound pressures were required to induce TTS than for longer-duration
tones.
Kastak et al. (1999a, 2005) conducted TTS experiments with
three species of pinnipeds, California sea lion,
[[Page 35551]]
northern elephant seal and a Pacific harbor seal, exposed to continuous
underwater sounds at levels of 80 and 95 dB SPL at 2.5 and 3.5 kHz for
up to 50 minutes. Mean TTS shifts of up to 12.2 dB occurred with the
harbor seals showing the largest shift of 28.1 dB. Increasing the sound
duration had a greater effect on TTS than increasing the sound level
from 80 to 95 dB.
Some of the more important data obtained from these studies are
onset-TTS levels (exposure levels sufficient to cause a just-measurable
amount of TTS) often defined as 6 dB of TTS (for example, Schlundt et
al., 2000) and the fact that energy metrics (sound exposure levels
(SEL), which include a duration component) better predict when an
animal will sustain TTS than pressure (SPL) alone. NMFS' TTS criteria
(which indicate the received level at which onset TTS (>6dB) is
induced) for MFAS/HFAS are as follows:
Cetaceans--195 dB re 1 [mu]Pa\2\-s (based on mid-frequency
cetaceans--no published data exist on auditory effects of noise in low
or high frequency cetaceans (Southall et al. (2007)).
Pinnipeds (monk seals)--204 dB re 1 [mu]Pa\2\-s (based on
data from elephant seals, which are the most closely related to the
monk seal).
A detailed description of how TTS criteria were derived from the
results of the above studies may be found in Chapter 3 of Southall et
al. (2007), as well as the Navy's HRC LOA application.
Level A Harassment Threshold (PTS)
For acoustic effects, because the tissues of the ear appear to be
the most susceptible to the physiological effects of sound, and because
threshold shifts tend to occur at lower exposures than other more
serious auditory effects, NMFS has determined that PTS is the best
indicator for the smallest degree of injury that can be measured.
Therefore, the acoustic exposure associated with onset-PTS is used to
define the lower limit of the Level A harassment.
PTS data do not currently exist for marine mammals and are unlikely
to be obtained due to ethical concerns. However, PTS levels for these
animals may be estimated using TTS data from marine mammals and
relationships between TTS and PTS that have been discovered through
study of terrestrial mammals. NMFS uses the following acoustic criteria
for injury:
Cetaceans--215 dB re 1 [mu]Pa\2\-s (based on mid-frequency
cetaceans--no published data exist on auditory effects of noise in low
or high frequency cetaceans (Southall et al. (2007)).
Pinnipeds (monk seals)--224 dB re 1 [mu]Pa\2\-s (based on
data from elephant seals, which are the most closely related to the
monk seal).
These criteria are based on a 20 dB increase in SEL over that
required for onset-TTS. Extrapolations from terrestrial mammal data
indicate that PTS occurs at 40 dB or more of TS, and that TS growth
occurs at a rate of approximately 1.6 dB TS per dB increase in EL.
There is a 34-dB TS difference between onset-TTS (6 dB) and onset-PTS
(40 dB). Therefore, an animal would require approximately 20dB of
additional exposure (34 dB divided by 1.6 dB) above onset-TTS to reach
PTS. A detailed description of how TTS criteria were derived from the
results of the above studies may be found in Chapter 3 of Southall et
al. (2007), as well as the Navy's HRC LOA application. Southall et al.
(2007) recommend a precautionary dual criteria for TTS (230 dB re 1
[mu]Pa (SPL) in addition to 215 re 1 [mu]Pa\2\-s (SEL)) to account for
the potentially damaging transients embedded within non-pulse
exposures. However, in the case of MFAS/HFAS, the distance at which an
animal would receive 215 (SEL) is farther from the source than the
distance at which they would receive 230 (SPL) and therefore, it is not
necessary to consider 230 dB.
We note here that behaviorally mediated injuries (such as those
that have been hypothesized as the cause of some beaked whale
strandings) could potentially occur in response to received levels
lower than those believed to directly result in tissue damage. As
mentioned previously, data to support a quantitative estimate of these
potential effects (for which the exact mechanism is not known and in
which factors other than received level may play a significant role) do
not exist. However, based on the number of years (more than 40) and
number of hours of MFAS per year that the U.S. (and other countries)
has operated compared to the reported (and verified) cases of
associated marine mammal strandings, NMFS believes that the probability
of these types of injuries is very low.
Level B Harassment Risk Function (Behavioral Harassment)
In 2006, NMFS issued the only MMPA authorization that has, as yet,
authorized the take of marine mammals incidental to MFAS. For that
authorization, NMFS used 173 SEL as the criterion for the onset of
behavioral harassment (Level B Harassment). This type of single number
criterion is referred to as a step function, in which (in this example)
all animals estimated to be exposed to received levels above 173 SEL
would be predicted to be taken by Level B Harassment and all animals
exposed to less than 173 SEL would not be taken by Level B Harassment.
As mentioned previously, marine mammal behavioral responses to sound
are highly variable and context specific (affected by differences in
acoustic conditions; differences between species and populations;
differences in gender, age, reproductive status, or social behavior; or
the prior experience of the individuals), which does not support the
use of a step function to estimate behavioral harassment.
Unlike step functions, acoustic risk continuum functions (which are
also called ``exposure-response functions,'' ``dose-response
functions,'' or ``stress-response functions'' in other risk assessment
contexts) allow for probability of a response that NMFS would classify
as harassment to occur over a range of possible received levels
(instead of one number) and assume that the probability of a response
depends first on the ``dose'' (in this case, the received level of
sound) and that the probability of a response increases as the ``dose''
increases (see Figure 3a). The Navy and NMFS have previously used
acoustic risk functions to estimate the probable responses of marine
mammals to acoustic exposures for other training and research programs.
Examples of previous application include the Navy FEISs on the SURTASS
LFA sonar (U.S. Department of the Navy, 2001c); the North Pacific
Acoustic Laboratory experiments conducted off the Island of Kauai
(Office of Naval Research, 2001), and the Supplemental EIS for SURTASS
LFA sonar (U.S. Department of the Navy, 2007d). As discussed in the
Effects section, factors other than received level (such as distance
from or bearing to the sound source) can affect the way that marine
mammals respond; however, data to support a quantitative analysis of
those (and other factors) do not currently exist. NMFS will continue to
modify these criteria as new data becomes available.
The particular acoustic risk functions developed by NMFS and the
Navy (see Figures 3a and b) estimate the probability of behavioral
responses to MFAS/HFAS (interpreted as the percentage of the exposed
population) that NMFS would classify as harassment for the purposes of
the MMPA given exposure to specific received levels of MFA sonar. The
mathematical function (below) underlying this curve is a cumulative
probability distribution adapted from a solution in Feller (1968) and
was also used in predicting risk for
[[Page 35552]]
the Navy's SURTASS LFA MMPA authorization as well.
[GRAPHIC] [TIFF OMITTED] TP23JN08.000
Where:
R = Risk (0--1.0)
L = Received level (dB re: 1 [mu]Pa)
B = Basement received level = 120 dB re: 1 [mu]Pa
K = Received level increment above B where 50 percent risk = 45 dB
re: 1 [mu]Pa
A = Risk transition sharpness parameter = 10 (odontocetes) or 8
(mysticetes)
In order to use this function to estimate the percentage of an
exposed population that would respond in a manner that NMFS classifies
as Level B Harassment, based on a given received level, the values for
B, K and A need to be identified.
B Parameter (Basement)--The B parameter is the estimated received
level below which the probability of disruption of natural behavioral
patterns, such as migration, surfacing, nursing, breeding, feeding, or
sheltering, to a point where such behavioral patterns are abandoned or
significantly altered approaches zero for the MFAS/HFAS risk
assessment. At this received level, the curve would predict that the
percentage of the exposed population that would be taken by Level B
Harassment approaches zero. For MFAS/HFAS, NMFS has determined that B =
120 dB. This level is based on a broad overview of the levels at which
many species have been reported responding to a variety of sound
sources.
K Parameter (representing the 50 percent Risk Point)--The K
parameter is based on the received level that corresponds to 50 percent
risk, or the received level at which we believe 50 percent of the
animals exposed to the designated received level will respond in a
manner that NMFS classifies as Level B Harassment. The K parameter (K =
45 dB) is based on three datasets in which marine mammals exposed to
mid-frequency sound sources were reported to respond in a manner that
NMFS would classify as Level B Harassment. There is widespread
consensus that marine mammal responses to MFA sound signals need to be
better defined using controlled exposure experiments (Cox et al., 2006;
Southall et al., 2007). The Navy is contributing to an ongoing
behavioral response study in the Bahamas that is expected to provide
some initial information on beaked whales, the species identified as
the most sensitive to MFAS. NMFS is leading this international effort
with scientists from various academic institutions and research
organizations to conduct studies on how marine mammals respond to
underwater sound exposures. Additionally, the Navy plans to tag whales
in conjunction with the 2008 RIMPAC exercises. Until additional data is
available, however, NMFS and the Navy have determined that the
following three data sets are most applicable for the direct use in
establishing the K parameter for the MFAS/HFAS risk function. These
data sets, summarized below, represent the only known data that
specifically relate altered behavioral responses (that NMFS would
consider Level B Harassment) to exposure to MFAS sources.
Even though these data are considered the most representative of
the proposed specified activities, and therefore the most appropriate
on which to base the K parameter (which basically determines the
midpoint) of the risk function, these data have limitations, which are
discussed in Appendix J of the Navy's FEIS for the HRC.
1. Controlled Laboratory Experiments with Odontocetes (SSC
Dataset)--Most of the observations of the behavioral responses of
toothed whales resulted from a series of controlled experiments on
bottlenose dolphins and beluga whales conducted by researchers at SSC's
facility in San Diego, California (Finneran et al., 2001, 2003, 2005;
Finneran and Schlundt, 2004; Schlundt et al., 2000). In experimental
trials (designed to measure TTS) with marine mammals trained to perform
tasks when prompted, scientists evaluated whether the marine mammals
performed these tasks when exposed to mid-frequency tones. Altered
behavior during experimental trials usually involved refusal of animals
to return to the site of the sound stimulus, but also included attempts
to avoid an exposure in progress, aggressive behavior, or refusal to
further participate in tests.
Finneran and Schlundt (2004) examined behavioral observations
recorded by the trainers or test coordinators during the Schlundt et
al. (2000) and Finneran et al. (2001, 2003, 2005) experiments. These
included observations from 193 exposure sessions (fatiguing stimulus
level > 141 dB re 1Pa) conducted by Schlundt et al. (2000) and 21
exposure sessions conducted by Finneran et al. (2001, 2003, 2005). The
TTS experiments that supported Finneran and Schlundt (2004) are further
explained below:
Schlundt et al. (2000) provided a detailed summary of the
behavioral responses of trained marine mammals during TTS tests
conducted at SSC San Diego with 1-sec tones and exposure frequencies of
0.4 kHz, 3 kHz, 10 kHz, 20 kHz and 75 kHz. Schlundt et al. (2000)
reported eight individual TTS experiments. The experiments were
conducted in San Diego Bay. Because of the variable ambient noise in
the bay, low-level broadband masking noise was used to keep hearing
thresholds consistent despite fluctuations in the ambient noise.
Schlundt et al. (2000) reported that ``behavioral alterations,'' or
deviations from the behaviors the animals being tested had been trained
to exhibit, occurred as the animals were exposed to increasing
fatiguing stimulus levels.
Finneran et al. (2001, 2003, 2005) conducted 2 separate
TTS experiments using 1-sec tones at 3 kHz. The test methods were
similar to that of Schlundt et al. (2000) except the tests were
conducted in a pool with very low ambient noise level (below 50 dB re 1
[mu]Pa\2\/hertz [Hz]), and no masking noise was used. In the first,
fatiguing sound levels were increased from 160 to 201 dB SPL. In the
second experiment, fatiguing sound levels between 180 and 200 dB SPL
were randomly presented.
Bottlenose dolphins exposed to 1-second (sec) intense tones
exhibited short-term changes in behavior above received sound levels of
178 to 193 dB re 1 [mu]Pa (rms), and beluga whales did so at received
levels of 180 to 196 dB and above.
2. Mysticete Field Study (Nowacek et al., 2004)--The only available
and applicable data relating mysticete responses to exposure to mid-
frequency sound sources is from Nowacek et al. (2004). Nowacek et al.
(2004) documented observations of the behavioral response of North
Atlantic right whales exposed to alert stimuli containing mid-frequency
components in the Bay of Fundy. Investigators used archival digital
acoustic recording tags (DTAG) to record the behavior (by measuring
pitch, roll, heading, and depth) of right whales in the presence of an
alert signal, and to calibrate received sound levels. The alert signal
was 18 minutes of exposure consisting of three 2-minute signals played
sequentially three times over. The three signals had a 60 percent duty
cycle and consisted of: (1) Alternating 1-sec pure tones at 500 Hz and
850 Hz; (2) a 2-sec logarithmic down-sweep from 4,500 Hz to 500 Hz; and
(3) a pair of low (1,500 Hz)-high (2,000 Hz) sine wave tones amplitude
modulated at 120 Hz and each 1-sec long. The purposes of the alert
signal were (a) to pique the mammalian auditory system with
[[Page 35553]]
disharmonic signals that cover the whales' estimated hearing range; (b)
to maximize the signal to noise ratio (obtain the largest difference
between background noise) and c) to provide localization cues for the
whale. The maximum source level used was 173 dB SPL.
Nowacek et al. (2004) reported that five out of six whales exposed
to the alert signal with maximum received levels ranging from 133 to
148 dB re 1 [mu]Pa significantly altered their regular behavior and did
so in identical fashion. Each of these five whales: (i) Abandoned their
current foraging dive prematurely as evidenced by curtailing their
`bottom time'; (ii) executed a shallow-angled, high power (i.e.
significantly increased fluke stroke rate) ascent; (iii) remained at or
near the surface for the duration of the exposure, an abnormally long
surface interval; and (iv) spent significantly more time at subsurface
depths (1-10 m) compared with normal surfacing periods when whales
normally stay within 1 m (1.1 yd) of the surface.
3. Odontocete Field Data (Haro Strait--USS SHOUP)--In May 2003,
killer whales (Orcinus orca) were observed exhibiting behavioral
responses generally described as avoidance behavior while the U.S. Ship
(USS) SHOUP was engaged in MFAS in the Haro Strait in the vicinity of
Puget Sound, Washington. Those observations have been documented in
three reports developed by Navy and NMFS (NMFS, 2005; Fromm, 2004a,
2004b; DON, 2003). Although these observations were made in an
uncontrolled environment, the sound field that may have been associated
with the sonar operations was estimated using standard acoustic
propagation models that were verified (for some but not all signals)
based on calibrated in situ measurements from an independent researcher
who recorded the sounds during the event. Behavioral observations were
reported for the group of whales during the event by an experienced
marine mammal biologist who happened to be on the water studying them
at the time. The observations associated with the USS SHOUP provide the
only data set available of the behavioral responses of wild, non-
captive animal upon actual exposure to AN/SQS-53 sonar.
U.S. Department of Commerce (National Marine Fisheries, 2005a);
U.S. Department of the Navy (2004b); Fromm (2004a, 2004b) documented
reconstruction of sound fields produced by USS SHOUP associated with
the behavioral response of killer whales observed in Haro Strait.
Observations from this reconstruction included an approximate closest
approach time which was correlated to a reconstructed estimate of
received level (which ranged from 150 to 180 dB) at an approximate
whale location with a mean value of 169.3 dB SPL.
Calculation of K Paramenter--NMFS and the Navy used the mean of the
following values to define the midpoint of the function: (1) The mean
of the lowest received levels (185.3 dB) at which individuals responded
with altered behavior to 3 kHz tones in the SSC data set; (2) the
estimated mean received level value of 169.3 dB produced by the
reconstruction of the USS SHOUP incident in which killer whales exposed
to MFA sonar (range modeled possible received levels: 150 to 180 dB);
and (3) the mean of the 5 maximum received levels at which Nowacek et
al. (2004) observed significantly altered responses of right whales to
the alert stimuli than to the control (no input signal) is 139.2 dB
SPL. The arithmetic mean of these three mean values is 165 dB SPL. The
value of K is the difference between the value of B (120 dB SPL) and
the 50 percent value of 165 dB SPL; therefore, K=45.
A Parameter (Steepness)--NMFS determined that a steepness parameter
(A)=10 is appropriate for odontocetes and pinnipeds and A=8 is
appropriate for mysticetes.
The use of a steepness parameter of A=10 for odontocetes for the
MFAS/HFAS risk function was based on the use of the same value for the
SURTASS LFA risk continuum, which was supported by a sensitivity
analysis of the parameter presented in Appendix D of the SURTASS/LFA
FEIS (U.S. Department of the Navy, 2001c). As concluded in the SURTASS
FEIS/EIS, the value of A=10 produces a curve that has a more gradual
transition than the curves developed by the analyses of migratory gray
whale studies (Malme et al., 1984; Buck and Tyack, 2000; and SURTASS
LFA Sonar EIS, Subchapters 1.43, 4.2.4.3 and Appendix D, and National
Marine Fisheries Service, 2008).
NMFS determined that a lower steepness parameter (A=8), resulting
in a shallower curve, was appropriate for use with mysticetes and MFAS/
HFAS. The Nowacek et al. (2004) dataset contains the only data
illustrating mysticete behavioral responses to a mid-frequency sound
source. A shallower curve (achieved by using A=8) better reflects the
risk of behavioral response at the relatively low received levels at
which behavioral responses of right whales were reported in the Nowacek
et al. (2004) data. Compared to the odontocete curve, this adjustment
results in an increase the proportion of the exposed population of
mysticetes being classified as behaviorally harassed at lower RLs, such
as those reported in and is supported by the only dataset currently
available.
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Basic Application of the Risk Function--The risk function is used
to estimate the percentage of an exposed population that is likely to
exhibit behaviors that would qualify as harassment (as that term is
defined by the MMPA applicable to military readiness activities, such
as the Navy's testing and training with MFA sonar) at a given received
level of sound. For example, at 165 dB SPL (dB re: 1 [mu]Pa rms), the
risk (or probability) of harassment is defined according to this
function as 50 percent, and Navy/NMFS applies that by estimating that
50 percent of the individuals exposed at that received level are likely
to respond by exhibiting behavior that NMFS would classify as
behavioral harassment. The risk function is not applied to individual
animals, only to exposed populations.
The data primarily used to produce the risk function (the K
parameter) were compiled from four species that had been exposed to
sound sources in a variety of different circumstances. As a result, the
risk function represents a general relationship between acoustic
exposures and behavioral responses that is then applied to specific
circumstances. That is, the risk function represents a relationship
that is deemed to be generally true, based on the limited, best-
available science, but may not be true in specific circumstances. In
particular, the risk function, as currently derived, treats the
received level as the only variable that is relevant to a marine
mammal's behavioral response. However, we know that many other
variables--the marine mammal's gender, age, and prior experience; the
activity it is engaged in during an exposure event, its distance from a
sound source, the number of sound
[[Page 35555]]
sources, and whether the sound sources are approaching or moving away
from the animal--can be critically important in determining whether and
how a marine mammal will respond to a sound source (Southall et al.,
2007). The data that are currently available do not allow for
incorporation of these other variables in the current risk functions;
however, the risk function represents the best use of the data that are
available.
As more specific and applicable data become available for MFAS/HFAS
sources, NMFS can use these data to modify the outputs generated by the
risk function to make them more realistic. Ultimately, data may exist
to justify the use of additional, alternate, or multi-variate
functions. For example, as mentioned previously, the distance from the
sound source and whether it is perceived as approaching or moving away
can affect the way an animal responds to a sound (Wartzok et al.,
2003). In the HRC example, animals exposed to received levels between
120 and 130 dB may be more than 65 nautical miles (131,651 yards
(120,381 m)) from a sound source (Table 16); those distances could
influence whether those animals perceive the sound source as a
potential threat, and their behavioral responses to that threat. Though
there are data showing marine mammal responses to sound sources at that
received level, NMFS does not currently have any data that describe the
response of marine mammals to sounds at that distance, much less data
that compare responses to similar sound levels at varying distances
(much less for MFAS/HFAS). However, if data were to become available,
NMFS would re-evaluate the risk function and to incorporate any
additional variables into the ``take'' estimates.
Explosive Detonation Criteria
The criteria for mortality, Level A Harassment, and Level B
Harassment resulting from explosive detonations were initially
developed for the Navy's Sea Wolf and Churchill ship-shock trials and
have not changed since other MMPA authorizations issued for explosive
detonations. The criteria, which are applied to cetaceans and
pinnipeds, are summarized in Table 13. Additional information regarding
the derivation of these criteria is available in the Navy's FEIS for
the HRC and in the Navy's CHURCHILL FEIS (U.S. Department of the Navy,
2001c).
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Take Calculations
Estimating the take that will result from the proposed activities
entails the following four steps: Propagation model estimates animals
exposed to sources at different levels; further modeling determines
number of exposures to levels indicated in criteria above (i.e., number
of takes); post-modeling corrections refine estimates to make them more
accurate; mitigation is taken into consideration. More information
regarding the models used, the assumptions used in the models, and the
process of estimating take is available in Appendix J of the Navy's
FEIS for the HRC.
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[[Page 35557]]
(1) In order to quantify the types of take described in previous
sections that are predicted to result from the Navy's specified
activities, the Navy first uses a sound propagation model that predicts
the number of animals that will be exposed to a range of levels of
pressure and energy (of the metrics used in the criteria) from MFAS/
HFAS and explosive detonations based on several important pieces of
information, including:
Characteristics of the sound sources.
[cir] Sonar source characteristics include: Source level (with
horizontal and vertical directivity corrections), source depth, center
frequency, source directivity (horizontal/vertical beam width and
horizontal/vertical steer direction), and ping spacing.
[cir] Explosive source characteristics include: The weight of an
explosive, the type of explosive, the detonation depth, number of
successive explosions.
Transmission loss (in 20 representative environmental
provinces across 8 sonar modeling areas) based on: Water depth; sound
speed variability throughout the water column (presume surface duct is
present in HRC); bottom geo-acoustic properties (bathymetry); and wind
speed.
The density of each marine mammal species in the HRC (see
Table 14), horizontally distributed uniformly and vertically
distributed according to dive profiles based on field data.
(2) Next, the criteria discussed in the previous section are
applied to the estimated exposures to predict the number of exposures
that exceed the criteria, i.e., the number of takes by Level B
Harassment, Level A Harassment, and mortality.
(3) During the development of the EIS for the HRC, NMFS and the
Navy determined that the output of the model could be made more
realistic by applying post-modeling corrections to account for the
following:
Acoustic footprints for sonar sources must account for
land masses (by subtracting them out).
Acoustic footprints for sonar sources should not be added
independently, rather, the degree to which the footprints from multiple
ships participating in the same exercise would typically overlap needs
to be taken into consideration.
Acoustic modeling should account for the maximum number of
individuals of a species that could potentially be exposed to sonar
within the course of 1 day or a discreet continuous sonar event if less
than 24 hours.
(4) Mitigation measures are taken into consideration. For example,
in some cases the raw modeled numbers of exposures to levels predicted
to result in Level A Harassment from exposure to sonar might indicate
that 1 fin whale would be exposed to levels of sonar anticipated to
result in PTS--However, a fin whale would need to be within
approximately 10 m of the source vessel in order to be exposed to these
levels. Because of the mitigation measures (watchstanders and shutdown
zone), size of fin whales, and nature of fin whale behavior, it is
highly unlikely that a fin whale would be exposed to those levels, and
therefore the Navy would not request authorization for Level A
Harassment of 1 fin whale. Table 15 contains the Navy's estimated take
estimates.
(5) Last, the Navy's specified activities have been described based
on best estimates of the number of MFAS/HFAS hours that the Navy will
conduct. The exact number of hours may vary from year to year, but will
not exceed the 5-year total indicated in Table 3 (by multiplying the
yearly estimate by 5) by more than 10 percent. NMFS estimates that a
10-percent increase in sonar hours would result in approximately a 10
percent increase in the number of takes, and we have considered this
possibility in our analysis.
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[[Page 35559]]
Mortality
Evidence from five beaked whale strandings, all of which have taken
place outside the HRC, and have occurred over approximately a decade,
suggests that the exposure of beaked whales to mid-frequency sonar in
the presence of certain conditions (e.g., multiple units using tactical
sonar, steep bathymetry, constricted channels, strong surface ducts,
etc.) may result in strandings, potentially leading to mortality.
Although these physical factors believed to contribute to the
likelihood of beaked whale strandings are not present, in their
aggregate, in the Hawaiian Islands, scientific uncertainty exists
regarding what other factors, or combination of factors, may contribute
to beaked whale strandings. Accordingly, to allow for scientific
uncertainty regarding contributing causes of beaked whale strandings
and the exact behavioral or physiological mechanisms that can lead to
the ultimate physical effects (stranding and/or death), the Navy has
requested authorization for take, by serious injury or mortality, of 10
individuals of each of the following species over the course of the
five-year rule: bottlenose dolphin, Kogia spp., melon-headed whale,
pantropical spotted dolphin, pygmy killer whale, short-finned pilot
whale, striped dolphin, Cuvier's, Longman's, and Blainville's beaked
whales. Neither NMFS nor the Navy anticipates that marine mammal
strandings or mortality will result from the operation of mid-frequency
sonar during Navy exercises within the HRC.
``Take'' Interpretation
For explosive detonations, a ``take'' (as reported in the take
table and proposed to be authorized), is very simply, an instance of
exposure of a marine mammal to levels above those indicated in the
criteria. Every separate take does necessarily represent effects to a
separate animal, some of the takes may be takes that occur to the same
animal, either within one day and one exercise, or on different days
from different exercise types.
For MFAS/HFAS, TTS and PTS takes can be described the same as the
explosive detonation takes described above. Alternately, for behavioral
harassment a take is slightly different from that described above.
Within the context of exposure to continuous ASW within exercises that
last less than 24 hrs (they typically last less than 16 hrs), one
behavioral harassment take might include more than one exposure to
MFAS/HFAS levels above those identified on the risk continuum within
the 11-16-hr. Then, however, the estimated numbers of take (in the take
table) represent instances of take. Again, every separate take does
necessarily represent effects to a separate animal, some animals may be
taken (which, as mentioned above, may include multiple exposures within
one day) more than one time on different days as a result of exposure
to different exercises.
Effects on Marine Mammal Habitat
There are no areas within the HRC that are specifically considered
as important physical habitat for marine mammals. The nearshore areas
in and around the Hawaiian Humpback Whale National Marine Sanctuary
contain very important breeding and calving habitat for the humpback
whale, however effects in this area have been analyzed previously in
this document in the context of the whales themselves. Additionally, in
2007, the Navy only conducted sonar training in the areas where
humpback whales are known to be densest for a total of approximately
30-40 hours.
The prey of marine mammals are considered part of their habitat.
The Navy's FEIS for the HRC contains a detailed discussion of the
potential effects to fish from MFAS/HFAS and explosive detonations.
Below is a summary of conclusions regarding those effects.
Effects on Fish From MFAS/HFAS
The extent of data, and particularly scientifically peer-reviewed
data, on the effects of high intensity sounds on fish is limited. In
considering the available literature, the vast majority of fish species
studied to date are hearing generalists and cannot hear sounds above
500 to 1,500 Hz (depending upon the species), and, therefore,
behavioral effects on these species from higher frequency sounds are
not likely. Moreover, even those fish species that may hear above 1.5
kHz, such as a few sciaenids and the clupeids (and relatives), have
relatively poor hearing above 1.5 kHz as compared to their hearing
sensitivity at lower frequencies. Therefore, even among the species
that have hearing ranges that overlap with some mid- and high-frequency
sounds, it is likely that the fish will only actually hear the sounds
if the fish and source are very close to one another. And, finally,
since the vast majority of sounds that are of biological relevance to
fish are below 1 kHz (e.g., Zelick et al., 1999; Ladich and Popper,
2004), even if a fish detects a mid-or high-frequency sound, these
sounds will not mask detection of lower frequency biologically relevant
sounds. Based on the above information, there will likely be few, if
any, behavioral impacts on fish.
Alternatively, it is possible that very intense mid- and high-
frequency signals, and particularly explosives, could have a physical
impact on fish, resulting in damage to the swim bladder and other organ
systems. However, even these kinds of effects have only been shown in a
few cases in response to explosives, and only when the fish has been
very close to the source. Such effects have never been indicated in
response to any Navy sonar. Moreover, at greater distances (the
distance clearly would depend on the intensity of the signal from the
source) there appears to be little or no impact on fish, and
particularly no impact on fish that do not have a swim bladder or other
air bubble that would be affected by rapid pressure changes.
Effects on Fish From Explosive Detonations
Underwater detonations are possible during SINKEX, EER/IEER, A-S
MISSILEX, S-S MISSILEX, BOMBEX, S-S GUNEX, and NSFS. The weapons used
in most missile and Live Fire Exercises pose little risk to fish unless
the fish were near the surface at the point of impact. Machine guns (50
caliber) and close-in weapons systems (anti-missile systems) fire
exclusively non-explosive ammunition. The same applies to larger
weapons firing inert ordnance for training (e.g., 5-inch guns and 76-mm
guns). The rounds pose an extremely low risk of a direct hit and
potential to directly affect a marine species. Target area clearance
procedures will again reduce this risk. A SINKEX uses a variety of live
fire weapons. These rounds pose a risk only at the point of impact.
Several factors determine a fish's susceptibility to harm from
underwater detonations. Most injuries in fish involve damage to air-or
gas-containing organs (i.e., the swim bladder). Fish with swim bladders
are vulnerable to effects of explosives, while fish without swim
bladders are much more resistant (Yelverton, 1981; Young, 1991).
Research has focused on the effects on the swim bladder from underwater
detonations but not the ears of fish (Edds-Walton and Finneran, 2006).
For underwater demolition training, the effects on fish from a
given amount of explosive depend on location, season, and many other
factors. O'Keeffe (1984) provides charts that allow estimation of the
potential effect on swim-bladder fish using a damage prediction method
developed by Goertner (1982). O'Keeffe's parameters include the size
[[Page 35560]]
of the fish and its location relative to the explosive source, but are
independent of environmental conditions (e.g., depth of fish, explosive
shot, frequency content).
Based on O'Keeffe's parameters, potential impacts on fish from
underwater demolition detonations would be negligible. A small number
of fish are expected to be injured by detonation of explosive, and some
fish located in proximity to the initial detonations can be expected to
die. However, the overall impacts on water column habitat would be
localized and transient. As training begins, the natural reaction of
fish in the vicinity would be to leave the area. When training events
are completed, the fish stock would be expected to return to the area.
Essential Fish Habitat (EFH) Determination
EFH is defined as ``those waters and substrates necessary to fish
for spawning, breeding, feeding or growth to maturity.'' Adverse
effects on EFH are defined further as ``any impact that reduces the
quality and/or quantity of EFH'' and may include ``site specific or
habitat-wide impacts, including individual, cumulative or synergistic
consequences of actions'', as well as direct or indirect physical,
chemical, or biological alterations of the waters or substrate and loss
of, or injury to, benthic organisms, prey species and their habitat,
and other ecosystem components, if such modifications reduce the
quality and/or quantity of EFH. The HRC is located in an area that has
been identified as essential fish habitat under the following Western
Pacific Regional Fishery Management Council (WPRFMC) Fishery Management
Plans (FMPs): Pelagics (eggs, larvae, juveniles, and adults),
Bottomfish (eggs, larvae, juveniles, and adults), Crustaceans (eggs,
larvae, juveniles, and adults), Coral Reef Ecosystem (eggs, larvae,
juveniles, and adults) and Precious Corals.
The Navy does not anticipate permanent, adverse impacts on EFH
components since training activities are conducted to avoid potential
impacts; however, there are temporary unavoidable impacts associated
with several training activities that may result in temporary and
localized impacts. In addition, a single operation may potentially have
multiple effects on EFH. The current and proposed training activities
in the HRC have the potential to result in the following impacts:
Physical disruption of open ocean habitat.
Physical destruction or adverse modification of benthic
habitats.
Alteration of water or sediment quality from debris or
discharge.
Cumulative impacts.
Each impact and operation associated with those impacts are
discussed in a separate document, Essential Fish Habitat and Coral Reef
Assessment for the Hawaii Range Complex EIS/OEIS (U.S. Department of
the Navy, 2007b) and a summary for each proposed activity is provided.
Potential impacts on FMP species include direct and indirect effects
from sonar and shock waves (see discussion above and EFH document, U.S.
Department of the Navy, 2007a). Numerous training activities may affect
benthic habitats from debris, and there may also be temporary impacts
on water quality from increased turbidity or release of materials.
However, due to the mitigation measures implemented to protect
sensitive habitats, and the localized and temporary impacts of the
Proposed Action, the Navy concluded that the potential impact of the
Proposed Action and alternatives on EFH for the five major FMPs and
their associated management units would be minimal. Additional detail
is provided in the Navy's FEIS on effects on EFH.
NMFS reviewed the Navy's Essential Fish Habitat and Coral Reef
Assessment for the Hawaii Range Complex EIS/OEIS (2007) in accordance
with the Fish and Wildlife Coordination Act (16 U.S.C. Section 662(a)),
the Magnuson-Stevens Fishery Conservation and Management Act (MSA) (16
U.S.C. Section 1855(b)(2)), the Coral Reef Executive Order 13089, and
NMFS'' essential fish habitat (EFH) regulations (50 CFR 600.905-930).
The Navy proposed the following mitigation measures to minimize
impacts to EFH: conducting training activities in open ocean away from
sensitive EFH, avoiding areas of live coral during inshore training
activities, and restricting amphibious landing to specific areas of
designated beaches. NMFS concurred that it is unlikely that the
proposed project would have adverse impacts to EFH for the various
WPRFMC FMPs, provided the proposed mitigation measures were implemented
to protect EFH in the area of operation.
Analysis and Negligible Impact Determination
Pursuant to NMFS regulations implementing the MMPA, an applicant is
required to estimate the number of animals that will be ``taken'' by
the specified activities (i.e., takes by harassment only, or takes by
harassment, injury, and/or death). This estimate informs the analysis
that NMFS must perform to determine whether the activity will have a
``negligible impact'' on the species or stock. Level B (behavioral)
harassment occurs at the level of the individual(s) and does not assume
any resulting population-level consequences, though there are known
avenues through which behavioral disturbance of individuals can result
in population-level effects (for example: pink-footed geese (Anser
brachyrhynchus) in undisturbed habitat gained body mass and had about a
46 percent reproductive success compared with geese in disturbed
habitat (being consistently scared off the fields on which they were
foraging) which did not gain mass and has a 17 percent reproductive
success). A negligible impact finding is based on the lack of likely
adverse effects on annual rates of recruitment or survival (i.e.,
population-level effects). An estimate of the number of Level B
harassment takes, alone, is not enough information on which to base an
impact determination. In addition to considering estimates of the
number of marine mammals that might be ``taken'' through behavioral
harassment, NMFS must consider other factors, such as the likely nature
of any responses (their intensity, duration, etc.), the context of any
responses (critical reproductive time or location, migration, etc.), or
any of the other variables mentioned in the first paragraph (if known),
as well as the number and nature of estimated Level A takes, the number
of estimated mortalities, and effects on habitat. Generally speaking,
and especially with other factors being equal, the Navy and NMFS
anticipate more severe effects from takes resulting from exposure to
higher received levels (though this is in no way a strictly linear
relationship throughout species, individuals, or circumstances) and
less severe effects from takes resulting from exposure to lower
received levels.
The Navy's specified activities have been described based on best
estimates of the number of MFAS/HFAS hours that the Navy will conduct.
The exact number of hours may vary from year to year, but will not
exceed the 5-year total indicated in Table 3 (by multiplying the yearly
estimate by 5) by more than 10 percent. NMFS estimates that a 10
percent increase in sonar hours would result in approximately a 10
percent increase in the number of takes, and we have considered this
possibility in our analysis.
Taking the above into account, and considering the sections
discussed below, NMFS has preliminarily determined that Navy training
exercises utilizing MFAS/HFAS and underwater detonations will have a
negligible
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impact on the marine mammal species and stocks present in the HRC.
Behavioral Harassment
As discussed in the Potential Effects of Exposure of Marine Mammals
to MFAS/HFAS and Underwater Detonations Section and illustrated in the
conceptual framework (Figure 2), marine mammals can respond to MFAS/
HFAS in many different ways, a subset of which qualify as harassment
(see Behavioral Harassment Section). One thing that the take estimates
do not take into account is the fact that most marine mammals will
likely avoid the source to one extent or another. Although an animal
that avoids the sound source might still be taken in some instances
(such as if the avoidance results in a missed opportunity to feed,
interruption of reproductive behaviors, etc.) in other cases avoidance
may result in fewer instances of take than were estimated or in the
takes resulting from exposure to a lower received level than was
estimated, which could result in a less severe response. For MFAS/HFAS,
the Navy provided information (Table 16) estimating what percentage of
the total takes occur within the 10-dB bins (without considering
mitigation or avoidance) that are within the received levels considered
in the risk continuum and for TTS and PTS. As mentioned above, an
animal's exposure to a higher received level is more likely to result
in a behavioral response that is more likely to adversely affect the
health of the animal.
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Because the Navy has only been monitoring specifically to discern
the effects of MFAS/HFAS on marine mammals since 2006, and because of
the overall datagap regarding the effects MFAS/HFAS on marine mammals,
not a lot is known regarding, specifically, how marine mammals in the
Hawaiian Islands will respond to MFAS/HFAS. For the five MTEs for which
NMFS has received a monitoring report, no instances of obvious
behavioral disturbance were observed either by the Navy watchstanders
or the independent observers (and a portion of the independent
observations were reported within the vicinity of operating MFAS) in
the 1,200+ hours of effort in which 77 sightings of marine mammals were
made. One cannot conclude from these results that marine mammals were
not harassed from MFAS/HFAS, as certainly a portion of animals within
the area of concern were not seen (especially those more cryptic deep-
diving species, such as beaked whales or Kogia sp.) and some of the
non-biologist watchstanders might not be well-qualified to characterize
behaviors. However, one can say that the animals that were observed,
which in the case of the watchstanders observations were the ones
closest to the source and likely exposed to the highest levels, did not
respond in any of the obviously more severe ways, such as panic,
aggression, or anti-predator response.
In addition to the monitoring that will be required pursuant to
this LOA, which is specifically designed to help us better understand
how marine mammals respond to sound, the Navy and NMFS have developed,
funded, and begun conducting a controlled exposure experiment with
beaked whales in the Bahamas.
Diel Cycle
As noted previously, many animals perform vital functions, such as
feeding, resting, traveling, and socializing, a diel cycle (24-hr
cycle). Substantive behavioral reactions to noise exposure (such as
disruption of critical life functions, displacement, or avoidance of
important habitat) are more likely to be significant if they last more
than one diel cycle or recur on subsequent days (Southall et al.,
2007). Consequently, a behavioral response lasting less than one day
and not recurring on subsequent days is not considered particularly
severe unless it could directly affect reproduction or survival
(Southall et al., 2007).
In the previous section, we discussed the fact that potential
behavioral responses to MFAS/HFAS that fall into the category of
harassment could range in severity. By definition, the takes by
behavioral harassment involve the disturbance of a marine mammal or
marine mammal stock in the wild by causing disruption of natural
behavioral patterns (such as migration, surfacing, nursing, breeding,
feeding, or sheltering) to a point where such behavioral patterns are
abandoned or significantly altered. These reactions would, however, be
more of a concern if they were expected to last over 24 hours or be
repeated in subsequent days, which is not expected. Because of the need
to train in a large variety of situations, the Navy does not typically
conduct successive MTEs or other ASW exercises in the same locations
(with the exception of the Navy's permanent instrumented ranges, such
as PMRF located off Kaui). Within one multi-day exercise, the
participants could potentially stay in one general area for multiple
days, but the area would typically cover something like 5000 mi\2\.
Separately, the average length of ASW
[[Page 35562]]
exercises (times of continuous sonar use) is approximately 12-16 hours
and the vessels involved are typically moving at a speed of 10-12
knots. When this is combined with the fact that the majority of the
cetaceans in the HRC would not likely remain in an area for successive
days (especially an area in waters deeper than 2000 m, which is where
the majority of the exercises take place), it is unlikely that animal
would be exposed to MFAS/HFAS at levels likely to result in a
substantive response that would then be carried on for more than one
day or on successive days.
TTS
NMFS and the Navy have estimated that individuals of a few species
of marine mammals may sustain some level of TTS (from MFAS or
explosives). As mentioned previously, TTS can last from a few minutes
to days, be of varying degree, and occur across various frequency
bandwidths. Table 15 indicates the estimated number of animals that
might sustain TTS from exposure to MFAS or explosives (fewer are likely
to have TTS from explosives). TTS is primarily classified by three
characteristics:
Frequency--Available data (of mid-frequency hearing
specialists exposed to mid to high frequency sounds--Southall et al.,
2007) suggest that most TTS occurs in the frequency of the source up to
one octave higher than the source (with the maximum at \1/2\ octave
above). The two hull-mounted MFAS sources (from which the TTS was
modeled) have center frequencies of 3.5 and 7.5 kHz, which suggests
that TTS induced by either of these sources would be in a frequency
band somewhere between approximately 2 and 20 kHz. Tables 17a and b
summarize the vocalization data for each species.
Degree of the shift (i.e., how many dB is the sensitivity
of the hearing reduced by)--generally, both the degree of TTS and the
duration of TTS will be greater if the marine mammal is exposed to a
higher level of energy (which would occur when the peak dB level is
higher or the duration is longer). The threshold for the onset of TTS
(> 6 dB) is 195 (SEL), which might be received at distances of up to
120 m from the MFAS source. An animal would have to approach closer to
the source or remain in the vicinity of the sound source appreciably
longer to increase the received SEL, which would be difficult
considering the watchstanders and the nominal speed of a sonar vessel
(15 knots). Of all TTS studies, some using exposures of almost an hour
in duration or up to 217 SEL, most of the TTS induced was 15 dB or
less, though Finneran et al., (2007) induced 43 dB of TTS with a 64-sec
exposure to a 20 kHZ source (MFAS only pings 2 times/minute).
Duration of TTS (Recovery time)--see above. Of all TTS
laboratory studies, some using exposures of almost an hour in duration
or up to 217 SEL, almost all recovered within in 1 day (or less, often
in minutes), though in one study (Finneran et al., (2007)), recovery
took 4 days.
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Based on the range of degree and duration of TTS reportedly induced
by exposures to non-pulse sounds of energy higher than that to which
free-swimming marine mammals in the field are likely to be exposed
during MFAS/HFAS training exercises, it is unlikely that marine mammals
would sustain a TTS from MFAS that alters their sensitivity by more
than 20 dB for more than a few days (and the majority would be far less
severe). Additionally (see Tables 17a and 17b), though the frequency
range of TTS that marine mammals might sustain would overlap with some
of their vocalization types, this frequency range of TTS would not
usually span the entire frequency range of one vocalization type, much
less span all types of vocalizations. It is worth noting that TTS from
MFAS could potentially result in reduced sensitivity to the
vocalizations of killer whales (potential predators). However, if
impaired, marine mammals would typically be aware of their impairment
and implement behaviors to compensate for it (see Communication
Impairment Section).
Acoustic Masking or Communication Impairment
Table 17 is also informative regarding the nature of the masking or
communication impairment that could potentially occur from MFAS (again,
center frequencies are 3.5 and 7.5 kHz). However, masking only occurs
during the time of the signal (and potential secondary arrivals of
indirect rays), versus TTS, which occurs continuously for its duration.
MFAS/HFAS pings last for about one second and occur about once every
24-30 seconds for hull-mounted sources. Though some of the
vocalizations that marine mammals make are less than one second long,
there is only a 1 in 24 chance that they would occur exactly when the
ping was received, and when vocalizations are longer than one second,
only parts of them are masked. Masking effects from MFAS/HFAS are
expected to be minimal. If masking or communication impairment were to
occur briefly, it would be in the frequency range of MFAS, which
overlaps with some marine mammal vocalizations, however, it would
likely not mask the entirety of any particular vocalization or
communication series because of the pulse length and duty cycle of the
MFAS signal.
PTS, Injury, or Mortality
No animals were predicted (through modeling) to be exposed to
levels of MFAS/HFAS that would result in direct physical injury.
Further, NMFS believes that many marine mammals would deliberately
avoid exposing themselves to the received necessary to induce injury
levels (i.e., approaching to within approximately 10 m (10.9 yd) (of
the source) by moving away from or at least modifying their path to
avoid a close approach. Last, in the unlikely event that an animal
approaches the sonar vessel at a close distance, NMFS believes that the
mitigation measures (i.e., shutdown/powerdown zones for MFAS/HFA)
further ensure that animals would be not be exposed to injurious levels
of sound. The Navy has indicated that they are capable of effectively
monitoring a 1000-meter (1093-yd) safety zone at night using night
vision goggles, infrared cameras, and passive acoustic monitoring.
The Navy's model estimated that 3 animals (one humpback whale, one
spotted dolphin, and one striped dolphin) would be exposed to explosive
detonations at levels that would result in injury--however, those
estimates do not consider mitigation measures. Surveillance during the
exercises for which injury was estimated (which includes aerial and
passive acoustic detection methods, when available, to ensure
clearance) begins two hours before the exercise and extends to 2 nm
(3704 m) from the source. Because of the behavior and visibility of
these species and the two hours of monitoring that occurs prior to
detonation, NMFS does not think that any animals will be exposed to
levels of sound or pressure that will result in injury from explosive
detonations.
As discussed previously, marine mammals could potentially respond
to MFAS at a received level lower than the injury threshold in a manner
that indirectly results in the animals stranding. The exact mechanisms,
behavioral or physiological are not known. However, based on the number
of occurrences where strandings have been definitively associated with
military sonar versus the number of hours of sonar that have been
conducted, we suggest that the probability is small that this will
occur. Additionally, proposed monitoring of shorelines before and after
major exercises combined with a shutdown protocol for live, in water,
strandings minimize the chances that live milling events turn into
mortalities.
Though NMFS does not expect it to occur, because of the uncertainty
surrounding the mechanisms that link exposure to MFAS to stranding
(especially in beaked whales), NMFS is proposing to authorize the
injury or mortality of 10 total individuals of each of these species
each over the course of the 5-yr rule: bottlenose dolphin, Kogia spp.,
melon-headed whale, pantropical spotted dolphin, pygmy killer whale,
short-finned pilot whale, striped dolphin, and Cuvier's, Longman's, and
Blainville's beaked whale.
Resident Populations/Additional Management Units
Studies of several odontocete species within the HRC suggest
demographically isolated populations might exist within the EEZ and
that some species show site-fidelity. Though only one stock is
designated for the HRC, both genetic testing and analysis of movement
suggest that a demographically isolated inshore population of false
killer whales exists within the Hawaiian EEZ and that individuals from
the offshore (genetically separate) Eastern North Pacific population
are also seen regularly within the Hawaii EEZ. Results from Baird et
al.'s, (in press) analysis of interisland movements of bottlenose
dolphins suggest that within the main Hawaiian Islands there are as
many as four discrete populations corresponding to the four main island
groupings (Nihau/Kaui, Oahu, 4-island:Molokai/Lanai/Maui/Kaho'olawe,
Hawaii). McSweeney et al. (2007) analyzed a 21-yr photographic record
of Cuvier's and Blainville's beaked whales and found evidence of long-
term (15-yr), multi-season site-fidelity on the west side of Hawaii.
If the nature of the Navy's training exercises was such that they
were disproportionately conducting sonar in a certain fairly large area
that largely overlapped with a particular demographically isolated
population, stock, or resident population, additional analysis might be
needed to determine what additional impacts might occur. However, due
to the Navy's need to train in a variety of bathymetric conditions and
in the vicinity of a variety of other resources throughout the Main
Hawaiian Islands, the location of the Navy's training exercises are
highly variable, with the exception of the Navy's ranges (PMRF, etc.).
40 Years of Navy Training Exercises Using MFAS/HFAS in the HRC
The Navy has been conducting MFAS/HFAS training exercises in the
HRC for over 40 years. During this time, NMFS found that sonar was a
plausible, if not likely, contributor to one milling/stranding event
that occurred in Hanalei Bay (see Stranding section: Hanalei), though
the cause of the event was not definitively determined. Though
monitoring specifically to determine the effects of sonar on marine
mammals was
[[Page 35566]]
not being conducted prior to 2006 and the symptoms indicative of
potential acoustic trauma were not as well recognized prior to the mid-
nineties, people have been collecting stranding data in Hawaii for 25
years. Though not all dead or injured animals are expected to end up on
the shore (some may be eaten or float out to sea), one might expect
that if marine mammals were being harmed by sonar with any regularity,
more evidence would have been detected over the 40-yr period.
Similarly, though population trends are not available for the vast
majority of the cetacean stocks in the HRC, data indicate that humpback
whale numbers are generally increasing both in Hawaii (7 percent rate
of increase between 1993 and 2007: Mobley, 2004) and in Southeast
Alaska (Caretta et al., 2007), where the majority of the Hawaii
humpback whales feed over the summer.
Species Conclusions
Mysticetes (Except Humpback Whale)
Bryde's whales, fin whales, sei whales, and Minke whales are not
expected to be encountered very often in the HRC. 64 instances each of
behavioral harassment of Bryde's and Minke whales, and 46 instances
each of behavioral harassment of fin and sei whales are estimated to
result from exposure to MFAS/HFAS (though this number does not take the
potential avoidance of the sound source into consideration). When the
numbers of behavioral takes are compared to the estimated abundance and
if one assumes that each ``take'' happens to a separate animal, less
than 20 percent of each of these Hawaiian stocks would be behaviorally
harassed during the course of a year (each animal one time per year).
No areas of specific importance for reproduction or feeding for these
species have been identified in the HRC.
The modeling indicates that these species will not be exposed to
levels associated with TTS or any type of injury as a result of the
Navy's action. Further, NMFS believes that many marine mammals would
avoid exposing themselves to the received levels necessary to induce
injury (i.e., avoid getting as close to the vessel as they would need
to: within approximately 10 m) by moving away from or at least
modifying their path to avoid a close approach. Last, NMFS believes
that the mitigation measures, including range clearance procedures for
explosives and shutdown/exclusion zones for MFAS/HFAS and explosives
would be effective at avoiding injurious exposures to animals that
approach the safety zone, especially in the case of these large
animals.
Sperm Whales
The modeling estimates that 767 instances of sperm whale behavioral
harassment will occur as a result of MFAS/HFAS training (758--though
this number does not take the potential avoidance of the sound source
into consideration) or underwater detonations (9). When the numbers of
behavioral takes are compared to the estimated abundance and if one
assumes that each ``take'' happens to a separate animal (and each
animal one time per year), less than 11 percent of the sperm whale
stock would be behaviorally harassed during the course of a year. More
likely, slightly fewer animals are harassed and a subset are taken more
than one time per year. No areas of specific importance for
reproduction or feeding for sperm whales have been identified in the
HRC.
The Navy's model predicted that 9 sperm whales might be exposed to
received levels of MFAS expected to cause TTS. However, due to the
large size of an individual, large average group size, and pronounced
blow of the sperm whale and the distance within which TTS levels are
expected to occur, watchstanders will very likely detect these whales
in time to shut down and prevent their exposures to levels of MFAS
associated with TTS.
The model also predicted that some animals might experience TTS as
a result of exposure to explosive detonations. For the same reasons
listed above, NMFS anticipates that the Navy watchstanders would detect
these species and implement the mitigation to avoid exposure. However,
two of the largest explosives (MK-84s and MK-48s) used in the training
exercises have a range to TTS that is larger than the exclusion zone
(see Table 8), which means that in the types of exercises that utilize
these explosives, it is possible that animals could experience TTS as a
result of being exposed beyond 1 nm (1.9 km) from the explosion.
Therefore, we estimate TTS could still occur incidental to exercise
types that utilize the two largest explosive types these explosives
(the Navy provided NMFS with take estimates broken down to the exercise
level), which results in an estimate of 4 sperm whales taken by TTS
from explosive detonations.
The modeling indicates that sperm whales will not be exposed to
levels associated with any type of injury or death as a result of the
Navy's action. Further, NMFS believes that many marine mammals would
deliberately avoid exposing themselves to MFAS/HFAS at the received
levels necessary to induce injury (and avoid getting as close to the
vessel as they would need to: within approximately 10 m (10.9 yd)) by
moving away from or at least modifying their path to avoid a close
approach. Last, NMFS believes that the mitigation measures would be
effective at avoiding injurious exposures to animal that approached
within the safety zone, especially in the case of these large animals.
Cryptic, Deep Diving Species
The modeling predicts that the following numbers of behavioral
harassments (Level B Harassment) of the associated species will occur:
2074 (dwarf sperm whales), 846 (pygmy sperm whales), 1136 (Cuvier's
beaked whales), 104 (Longmans's beaked whales), and 349 (Blainvilles
beaked whales). When the numbers of behavioral takes are compared to
the estimated abundance and if one assumes that each ``take'' happens
to a separate animal (one time per year), less than 13 percent of each
of these stocks would be behaviorally harassed during the course of a
year. More likely, fewer individuals would be taken, but a subset would
be taken more than one time per year. No areas of specific importance
for reproduction or feeding for these species have been identified in
the HRC.
The Navy's model predicted that the following number of each of the
species would sustain TTS (Level B Harassment) from exposure to MFAS:
35 (dwarf sperm whales), 14 (pygmy sperm whales), 5 (Cuvier's beaked
whales), 1 (Longmans's beaked whales), and 6 (Blainvilles beaked
whales). Though some of these predicted takes might be avoided if the
animals avoided the source or if they were sighted by the
watchstanders, because the species are all deep divers that are cryptic
at the surface, we will assume that they actually sustain the TTS takes
that are modeled. As mentioned above, some beaked whale vocalizations
might overlap with the MFAS/HFAS TTS frequency range (2-20 kHz), but
the limited information for Kogia sp. indicates that their echolocation
clicks are at a much higher frequency and that their maximum hearing
sensitivity is between 90 and 150 kHz. It is worth noting that TTS in
the range induced by MFAS would reduce sensitivity in the band that
killer whales click and echolocate in. However, as noted previously,
NMFS does not anticipate TTS of a long duration or severe degree to
occur as a result of exposure to MFA/HFAS. The model also predicted TTS
takes from explosive detonations: 13 (dwarf sperm whales), 5 (pygmy
sperm
[[Page 35567]]
whales), 8 (Cuvier's beaked whales), and 2 (Blainvilles beaked whales).
The modeling indicates that none of these species would be injured
as a result of the Navy's action. Further, NMFS believes that many
marine mammals would deliberately avoid exposing themselves to the
received MFAS/HFAS levels necessary to induce injury (and avoid getting
as close to the vessel as they would need to: within approximately 10 m
(10.9 yd)) by moving away from or at least modifying their path to
avoid a close approach. Last, NMFS believes that the mitigation
measures would be effective at avoiding injurious exposures (which
would only occur within approximately 10 m (10.9 yd) of the vessel) if
an animal did happen to approach that closely.
Although NMFS does not expect mortality of any of these five
species to occur as a result of the MFAS/HFAS training exercises (see
Mortality paragraph above), because we intend to authorize mortality,
we consider the 10 potential mortalities of each of these species over
the course of 5 years in our negligible impact determination.
Social Pelagic Species
The modeling predicts that the following numbers of behavioral
harassments of the associated species will occur: 46 (false killer
whales), 46 (killer whales), 192 (Pygmy killer whales), 1753 (short-
finned pilot whales), and 583 (melon-headed whales). When the numbers
of behavioral takes are compared to the estimated abundance and if one
assumes that each ``take'' happens to a separate animal, less than 22
percent of each of these stocks would be behaviorally harassed during
the course of a year (one time per animal). More likely, fewer
individuals would be taken and a small subset would be harassed more
than one time per year. No areas of specific importance for
reproduction or feeding for these species have been identified in the
HRC.
The Navy's model predicted that these species might be exposed to
received levels of MFAS expected to cause TTS. However, because of the
average group size, large animal size, and the distance from the vessel
in which TTS levels are expected to occur (120-160m), watchstanders
will very likely detect these whales in time to shut down and prevent
their exposures to levels of MFAS associated with TTS. The model also
predicted that melon-headed whales and short-finned pilot whales might
experience TTS as a result of explosive detonations. For the same
reasons listed above, NMFS anticipates that the Navy watchstanders
would detect these species and implement the mitigation to avoid
exposure. However, two of the largest explosives (MK-84s and MK-48s)
used in the training exercises have a range to TTS that is larger than
the exclusion zone (see Table 8), which means that in the types of
exercises that utilize these explosives, it is possible that animals
could experience TTS as a result of being exposed beyond 1 nm from the
explosion. Therefore, we estimate TTS takes could still occur
incidental to exercise types that utilize two largest explosive types
(the Navy provided NMFS with take estimates broken down to the exercise
level), which results in the following estimates of take from explosive
detonations: 1 short-finned pilot whale.
As mentioned previously, TTS from MFAS is anticipated to occur
primarily in the 2-20 kHz range. If any individuals of these species
were to experience TTS from MFAS/HFAS, the information in Table 7
indicates that the TTS would likely overlap with some of the
vocalizations of conspecifics, and not with others. However, as noted
previously, NMFS does not anticipate TTS of a long duration or severe
degree to occur as a result of exposure to MFA/HFAS.
The modeling indicates that none of these species would be injured
as a result of the Navy's action. Further, NMFS believes that many
marine mammals would deliberately avoid exposing themselves to the
received levels necessary to induce injury (and avoid getting as close
to the vessel as they would need to: Within approximately 10 m (10.9
yd)) by moving away from or at least modifying their path to avoid a
close approach. Last, NMFS believes that the mitigation measures would
be effective at avoiding injurious exposures (which would only occur
within approximately 10 m (10.9 yd) of the vessel) if an animal did
happen to approach that closely.
Although NMFS does not expect mortality of any of these three
species to occur as a result of the MFAS/HFAS training exercises (see
Mortality paragraph above), because we intend to authorize mortality,
we consider the 10 total potential mortalities (over the course of 5
years) of melon-headed whales, pygmy killer whales, and short-finned
pilot whales in our negligible impact determination.
Dolphins
The modeling predicts that the following numbers of behavioral
harassments of the associated species will occur: 716 (bottlenose
dolphins), 486 (Risso's dolphins), 1055 (rough-toothed dolphin), 1222
(Fraser's dolphin), and 2144 (pantropical spotted dolphin), 412
(spinner dolphin), and 3128 (striped dolphin). When the numbers of
behavioral takes are compared to the estimated abundance and if one
assumes that each ``take'' happens to a separate animal (one time per
year), 12-24 percent of each of these stocks would be behaviorally
harassed during the course of a year. More likely, slightly fewer
individuals are harassed, but a subset are harassed more than one time
during the course of the year. No areas of specific importance for
reproduction or feeding for these species have been identified in the
HRC, though several bays have been identified as important resting
areas for spinner dolphins (the Navy conducts the majority of exercises
in water deeper than 2000 m).
The Navy's model predicted that a certain number of individuals of
these dolphin species would sustain TTS as a result of exposure to
MFAS. Though the group size and behavior of these species makes it
likely that watchstanders would detect them and implement shutdown if
appropriate, the proposed mitigation has a provision that allows them
to continue operation of MFAS if the animals are clearly bow-riding
even after the Navy has initially maneuvered to try and avoid closing
with the animals. Since these animals sometimes bow-ride and they would
be close enough to sustain TTS, we estimate that half of the number of
animals modeled for MFAS/HFAS TTS might actually sustain TTS: 9
(bottlenose dolphins), 5 (Risso's dolphins), 9 (rough-toothed dolphin),
10 (Fraser's dolphin), and 25 (pantropical spotted dolphin), 4 (spinner
dolphin), and 37 (striped dolphin). As mentioned above, many of the
recorded dolphin vocalizations overlap with the MFAS/HFAS TTS frequency
range (2-20kHz), however, as noted above, NMFS does not anticipate TTS
of a serious degree or extended duration to occur. It is worth noting
that TTS is in the range induced by MFAS would reduce sensitivity in
the band that killer whales click and echolocate in.
The model also predicted that individuals of this species would
experience TTS from explosives. For the same reasons listed above, NMFS
anticipates that the Navy watchstanders would detect these species and
implement the mitigation to avoid exposure. However, as mentioned in
the Social Pelagic Section, the range to TTS for the two largest
explosives is larger than the exclusion zone (see Table 8), and
therefore NMFS anticipates that TTS might not be entirely avoided
[[Page 35568]]
during those exercises, which results in the following predicted TTS
takes from explosives: 2 (rough-toothed dolphin), 3 (Fraser's dolphin),
1 (spinner dolphin), and 2 (striped dolphin).
The modeling indicates that none of these species would be injured
as a result of exposure to MFAS/HFAS. Further, NMFS believes that many
marine mammals would deliberately avoid exposing themselves to the
received levels necessary to induce injury (and avoid getting as close
to the vessel as they would need to: within approximately 10 m (10.9
yd)) by moving away from or at least modifying their path to avoid a
close approach. Last, NMFS believes that the mitigation measures would
be effective at avoiding injurious exposures (which would only occur
within approximately 10 m (10.9 yd) of the vessel) if an animal did
happen to approach that closely.
The model predicted that one pantropical spotted dolphin and one
striped dolphin would be exposed to injurious levels of energy or
pressure from an explosive detonation. However, as stated previously,
the relatively small area in which an animal would have to be to be
injured (12-1023 m) and the visibility of these species, coupled with
the 1862-m (2036-yd) exclusion zone (no explosives detonated if animals
are in there), which is surveyed up to 2 hours in advance of the
exercise by vessel-based observers, as well as aerial and passive
acoustic means (when available), support the determination that
individuals of these species will not likely be injured by explosive
detonations.
Although NMFS does not expect mortality of any of these species to
occur as a result of the MFAS/HFAS training exercises (see Mortality
paragraph above), because we intend to authorize mortality, we must
consider the 10 total potential mortalities (over the course of 5
years) of bottlenose dolphin, pantropical spotted dolphins, and striped
dolphins in our negligible impact determination.
Monk Seals
The modeling predicts 104 instances of behavioral harassments of
monk seals. When the number of behavioral takes is compared to the
estimated abundance and if one assumes that each ``take'' happens to a
separate animal, approximately 8.3 percent of the stock would be
behaviorally harassed during the course of a year. More likely, a
smaller number of individuals would be harassed, and a subset would be
harassed more than one time. More than likely, also, the 77 animals
that reside in the main Hawaiian Islands would be the animals harassed.
No areas of specific importance for reproduction or feeding for these
species have been identified in waters of the HRC.
The Navy's model predicted that monk seals might be exposed to
received levels of MFAS expected to cause TTS 3 times. Monk seals
generally forage at depths of less than 100 m (109 yd), but
occasionally dive to depths of over 500 m (546 yd). The majority of ASW
training in the HRC, however, takes place in waters 4 to 8 times deeper
than even this known (500-m (546-yd)) maximum and it is very rare for
ASW training to take place in waters as shallow as 100 m (109 yd) in
depth. So, generally, monk seals are less likely to be in the vicinity
of ASW activities, and we believe that watchstanders are likely to spot
the seals before they could close within the distance necessary to
sustain TTS, which would be less than 100 m (109 yd). For these reasons
we do not believe that any monk seals will experience TTS.
The Navy's model also predicted that 3 monk seals might be exposed
to explosive levels that would result in the TTS. However, because of
the likelihood of spotting these animals within the distance necessary
to avoid TTS and implementing the exclusion zone (i.e., not detonating
explosives) and the fact that the TTS takes that were modeled were not
incidental to exercises using the two largest explosives, NMFS does not
anticipate that any monk seals will experience TTS.
The model-estimates that individuals of this species would not be
injured as a result of the Navy's action. Further, NMFS believes that
monk seals would deliberately avoid exposing themselves to the received
levels necessary to induce injury (and avoid getting as close to the
vessel as they would need to: within approximately 10 m (10.9 yd)) by
moving away from or at least modifying their path to avoid a close
approach. Last, NMFS believes that the mitigation measures would be
effective at avoiding injurious exposures (which would only occur
within approximately 10 m (10.9 yd) of the vessel) if an animal did
happen to approach that closely.
Humpback Whales
The modeling estimates that 9,682 instances of humpback whale
behavioral harassment would occur as a result of Navy training. This
may be an overestimate. The Hawaiian Humpback Whale National Marine
Sanctuary worked with Dr. Joe Mobley to compile a figure that
illustrates 10 years worth of humpback density data (Figure 2). This
map generally shows the distribution of humpbacks throughout the Main
Hawaiian Islands over 10 years and clearly depicts several ``hot
spots'' where the density (on average--over 4 surveys) far exceeds the
density elsewhere in the HRC (high density areas are up to 3.8 animals/
square mile (Mobley, pers. comm)). However, the Navy applied a uniform
distribution of humpback whales within 25 km (46.3 nm) of shore to
estimate take in their model. Additionally, the Navy has indicated
that, historically, they have conducted a very small amount of MFAS/
HFAS transmissions in the dense humpback areas (they estimate
approximately 30 hours of hull-mounted sonar were conducted in these
areas in 2007), although they cannot commit to any particular levels of
MFAS/HFAS use in the areas in the future because of the need for
flexibility in training (every area has different characteristics and
exercise participants need to be exposed to a large variety of training
scenarios).
As described in the monk seal section, the Navy has indicated that
the majority of ASW training in the HRC takes place in waters 2000-4000
m (2187-4374 yd) deep and it is very rare for ASW training to take
place in waters as shallow as 100 m (109 yd) in depth. Based on the
bathymetry of the islands and the map of the densest areas of
humpbacks, this means that the majority of the exercises are 2-15 km
(1-8 nm), or farther, out from the densest areas of humpbacks, which
would suggest, based on table 16, that the majority of behavioral takes
of humpbacks would occur at received levels less than 150-160 dB. This
suggests that the overall potential severity of the effects is likely
less than one would anticipate if humpbacks were not selectively using
the shallower, inshore areas and the Navy were not conducting the
majority of their exercises in deeper areas. Additionally, the Navy has
designated a cautionary area in the Maui Basin (see Mitigation) which
the Navy recognizes as an area of importance to humpback whales. As
noted above, the Navy has agreed that training exercises in the
humpback whale cautionary area will require a much higher level of
clearance than is normal practice in planning and conducting MFA sonar
training. Any determination by the Commander, Pacific Fleet, to conduct
training exercises in the cautionary area will be based on the unique
characteristics of the area from a military readiness perspective,
taking into account the importance of the area for humpback whales. The
model results suggest that each humpback whale in the HRC may be
harassed somewhere between
[[Page 35569]]
approximately 1 and 3 times per year, though more than likely some will
not be harassed at all and a subset will be harassed more than 3 times/
year. However, as mentioned previously, the estimated takes do not
factor in the fact that a portion of the animals will likely avoid the
sound to some degree.
The Navy's model predicted that 199 humpback whales might be
exposed to received levels of MFAS expected to cause TTS. However, due
to the large size and social behavior of humpback whales and the
distance within which TTS levels are expected to occur, watchstanders
will very likely detect these whales in time to shut down and prevent
their exposures to levels of MFAS associated with TTS. If TTS were to
occur in some humpbacks, desensitization at the frequencies of humpback
vocalizations could occur due to the MFAS/HFAS TTS frequency range (2-
20 kHz), however, as noted above, NMFS does not anticipate TTS of
serious degree or extended duration to occur. Additionally of note,
recent measurements of humpback whale calf calls, which were measured
at frequencies of 140Hz to 4 kHz, with a mean frequency of 220 Hz,
suggest that if a humpback did have TTS from MFAS exposure, it would
not overlap with the majority of the range of the call that a calf
might make, suggesting that the temporary impairment would not increase
the risk of cow/calf separation.
The model also predicted that TTS takes from explosives that might
occur. For the same reasons listed above, NMFS anticipates that the
Navy watchstanders would detect these species and implement the
mitigation to avoid exposure. However, as mentioned in the Social
Pelagic Section, the range to TTS for the two largest explosives is
larger than the exclusion zone (see Table 8), and therefore NMFS
anticipates that TTS might not be entirely avoided during those
exercises, which results in 4 predicted TTS takes of humpbacks from
explosive detonations.
The modeling indicates that humpback whales will not be exposed to
levels associated with any type of injury as a result of exposure to
MFAS/HFAS. Further, NMFS believes that many marine mammals would avoid
exposing themselves to the received levels necessary to induce injury
(and avoid getting as close to the vessel as they would need to: within
approximately 10 m (10.9 yd)) by moving away from or at least modifying
their path to avoid a close approach. Also, NMFS believes that the
mitigation measures would be effective at avoiding injurious exposures
to animal that approached within the safety zone, especially in the
case of these large animals.
The model predicts that 1 humpback would be injured by an explosive
detonation. However, as stated previously, the relatively small area
within which an animal would have to be present at a particular moment
to be injured (12 to 1023 m (13 to 1119 yd)) and the visibility of
these species, coupled with the 1862-m (2036-yd) exclusion zone (no
explosives detonated if animals are in there), which is surveyed up to
2 hours in advance of the exercise by vessel-based observers, as well
as aerial and passive acoustic means (when available), support the
determination that no humpback whales will be injured by explosive
detonations.
Last, as mentioned above, humpback whale numbers are reported to be
increasing both in Hawaii and in Alaska, where the majority of the
Hawaii humpback whales feed in the summer.
Subsistence Harvest of Marine Mammals
NMFS has preliminarily determined that the issuance of an LOA for
Navy training exercises in the HRC would not have an unmitigable
adverse impact on the availability of the affected species or stocks
for subsistence use, since there are no such uses in the specified
area.
ESA
There are seven marine mammal species and five sea turtle species
that are listed as endangered under the ESA with confirmed or possible
occurrence in the study area: humpback whale, North Pacific right
whale, sei whale, fin whale, blue whale, sperm whale, and Hawaiian monk
seal, loggerhead sea turtle, the green sea turtle, hawksbill sea
turtle, leatherback sea turtle, and olive ridley sea turtle. The Navy
has begun consultation with NMFS pursuant to section 7 of the ESA, and
NMFS will also consult internally on the issuance of an LOA under
section 101(a)(5)(A) of the MMPA for training exercises in the HRC.
Consultation will be concluded prior to a determination on the issuance
of the final rule and an LOA.
NEPA
NMFS has participated as a cooperating agency on the Navy's Final
Environmental Impact Statement (FEIS) for the Hawaii Range Complex,
which was published on May 9th, 2008. Additionally, NMFS is preparing a
Draft Environmental Assessment (EA) tiered off the Navy's FEIS that
analyzes the environmental effects of several different mitigation
alternatives for the potential issuance of the HRC proposed rule and
LOA. The Draft EA will be posted on NMFS' Web site as soon as it is
complete: http://www.nmfs.noaa.gov/pr/permits/incidental.htm. The
Navy's FEIS is also posted on NMFS website.
NMFS intends to adopt the Navy's FEIS, if adequate and appropriate,
and we believe that the Navy's FEIS and NMFS' final EA will allow NMFS
to meet its responsibilities under NEPA for the issuance of an LOA for
training activities in the HRC. If the Navy's FEIS were not adequate,
NMFS would supplement the existing analysis and documents to ensure
that we comply with NEPA prior to the issuance of the final rule or
LOA.
Preliminary Determination
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat and dependent
upon the implementation of the mitigation measures, NMFS preliminarily
finds that the total taking from Navy training exercises utilizing
MFAS/HFAS and underwater explosives in the HRC will have a negligible
impact on the affected species or stocks. NMFS has proposed regulations
for these exercises that prescribe the means of affecting the least
practicable adverse impact on marine mammals and their habitat and set
forth requirements pertaining to the monitoring and reporting of that
taking.
Classification
This action does not contain a collection of information
requirement for purposes of the Paperwork Reduction Act.
Pursuant to the procedures established to implement section 6 of
Executive Order 12866, the Office of Management and Budget has
determined that this proposed rule is significant.
Pursuant to the Regulatory Flexibility Act, the Chief Counsel for
Regulation of the Department of Commerce has certified to the Chief
Counsel for Advocacy of the Small Business Administration that this
rule, if adopted, would not have a significant economic impact on a
substantial number of small entities. The Regulatory Flexibility Act
requires Federal agencies to prepare an analysis of a rule's impact on
small entities whenever the agency is required to publish a notice of
proposed rulemaking. However, a Federal agency may certify, pursuant to
5 U.S.C. section 605 (b), that the action will not have a significant
economic impact on a substantial number of small entities.
[[Page 35570]]
The Navy is the entity that will be affected by this rulemaking, not a
small governmental jurisdiction, small organization or small business,
as defined by the Regulatory Flexibility Act. Any requirements imposed
by a Letter of Authorization issued pursuant to these regulations, and
any monitoring or reporting requirements imposed by these regulations,
will be applicable only to the Navy. Because this action, if adopted,
would directly affect the Navy and not a small entity, NMFS concludes
the action would not result in a significant economic impact on a
substantial number of small entities.
List of Subjects in 50 CFR Part 216
Exports, Fish, Imports, Incidental take, Indians, Labeling, Marine
mammals, Navy, Penalties, Reporting and recordkeeping requirements,
Seafood, Sonar, Transportation.
Dated: June 13, 2008.
Samuel D. Rauch III
Deputy Assistant Administrator for Regulatory Programs, National Marine
Fisheries Service.
For reasons set forth in the preamble, 50 CFR part 216 is proposed
to be amended as follows:
PART 216--REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE
MAMMALS
1. The authority citation for part 216 continues to read as
follows:
Authority: 16 U.S.C. 1361 et seq.
2. Subpart P is added to part 216 to read as follows:
Subpart P--Taking Marine Mammals Incidental to U.S. Navy Training
in the Hawaii Range Complex (HRC)
Sec.
216.170 Specified activity and specified geographical region.
216.171 Effective dates and definitions.
216.172 Permissible methods of taking.
216.173 Prohibitions.
216.174 Mitigation.
216.175 Requirements for monitoring and reporting.
216.176 Applications for Letters of Authorization.
216.177 Letters of Authorization.
216.178 Renewal of Letters of Authorization.
216.179 Modifications to Letters of Authorization.
Table 1 to Part 216, Subpart P--Summary of Monitoring Effort
Proposed in Monitoring Plan for Hawaii Range Complex
Subpart P--Taking Marine Mammals Incidental to U.S. Navy Training
in the Hawaii Range Complex (HRC)
Sec. 216.170 Specified activity and specified geographical region.
(a) Regulations in this subpart apply only to the U.S. Navy for the
taking of marine mammals that occurs in the area outlined in paragraph
(b) of this section and that occur incidental to the activities
described in paragraph (c) of this section
(b) The taking of marine mammals by the Navy is only authorized if
it occurs within the Hawaii Operational Area, which extends from 16 to
43o N. lat. and from 150-179[deg] degrees W. long.,
(c) The taking of marine mammals by the Navy is only authorized if
it occurs incidental to the following activities within the designated
amounts of use:
(1) The use of the following mid-frequency active sonar (MFAS) and
high frequency active sonar (HFAS) sources for U.S. Navy anti-submarine
warfare (ASW) training in the amounts indicated below ( 10
percent):
(i) AN/SQS-53 (hull-mounted sonar)--up to 6420 hours over the
course of 5 years (an average of 1284 hours per year)
(ii) AN/SQS-56 (hull-mounted sonar)--up to 1915 hours over the
course of 5 years (an average of 383 hours per year)
(iii) AN/AQS-22 (helicopter dipping sonar)--up to 5050 dips over
the course of 5 years (an average of 1010 dips per year)
(iv) SSQ-62 (sonobuoys)--up to 12115 sonobuoys over the course of 5
years (an average of 2423 sonobuoys per year)
(v) MK-48 (torpedoes)--up to 1565 topedoes over the course of 5
years (an average of 313 torpedoes per year)
(vi) AN/BQQ-10 (submarine mounted sonar)--up to 1,000 hours over
the course of 5 years (an average of 200 per year)
(2) The detonation of the underwater explosives indicated in
paragraph (c)(2)(i) of this section conducted as part of the training
exercises indicated in paragraph (c)(2)(ii) of this section:
(i) Underwater Explosives:
(A) 5'' Naval Gunfire (9.5 lbs)
(B) 76 mm rounds (1.6 lbs)
(C) Maverick (78.5 lbs)
(D) Harpoon (448 lbs)
(E) MK-82 (238 lbs)
(F) MK-83 (574 lbs)
(G) MK-84 (945 lbs)
(H) MK-48 (851 lbs)
(I) Demolition Charges (20 lbs)
(J) EER/IEER (5 lbs)
(ii) Training Events:
(A) Mine Neutralization--up to 310 exercises over the course of 5
years (an average of 62 per year).
(B) Air-to-Surface MISSILEX--up to 180 exercises over the course of
5 years (an average of 36 per year).
(C) Surface-to-Surface MISSILEX--up to 35 exercises over the course
of 5 years (an average of 7 per year).
(D) BOMBEX--up to 180 exercises over the course of 5 years (an
average of 35 per year).
(E) SINKEX--up to 30 exercises over the course of 5 years (an
average of 6 per year).
(F) Surface-to-Surface GUNEX--up to 345 exercises over the course
of 5 years (an average of 69 per year).
(G) Naval Surface Fire Support--up to 110 exercises over the course
of 5 years (an average of 22 per year).
Sec. 216.171 Effective dates and definitions.
(a) Regulations in this subpart become effective upon issuance of
the final rule.
(b) The following definitions are utilized in this subpart:
(1) Uncommon Stranding Event (USE)--A stranding event that takes
place during a major training exercise and involves any one of the
following:
(i) Two or more individuals of any cetacean species (not including
mother/calf pairs, unless of species of concern listed in next bullet)
found dead or live on shore within a two day period and occurring on
same shore lines or facing shorelines of different islands.
(ii) A single individual or mother/calf pair of any of the
following marine mammals of concern: Beaked whale of any species, kogia
sp., Risso's dolphin, melon-headed whale, pilot whales, humpback
whales, sperm whales, blue whales, fin whales, sei whales, or monk
seal.
(iii) A group of 2 or more cetaceans of any species exhibiting
indicators of distress.
(2) Shutdown--The cessation of MFAS operation or detonation of
explosives within 14 nm of any live, in the water animal involved in a
USE.
Sec. 216.172 Permissible methods of taking.
(a) Under Letters of Authorization issued pursuant to Sec. Sec.
216.106 and 216.177, the Holder of the Letter of Authorization may
incidentally, but not intentionally, take marine mammals within the
area described in Sec. 216.170(b), 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. 216.170(c) must be conducted
in a manner that minimizes, to the greatest
[[Page 35571]]
extent practicable, any adverse impacts on marine mammals and their
habitat.
(c) The incidental take of marine mammals under the activities
identified in Sec. 216.170 (c) is limited to the following species, by
the indicated method of take the indicated number of times:
(1) Level B Harassment (+/-10 percent):
(i) Mysticetes:
(A) Humpback whale (Megaptera novaeangliae)--9893.
(B) Minke whale (Balaenoptera acutorostrata)--64.
(C) Sei whale (Balaenoptera borealis)--46.
(D) Fin whale (Balaenoptera physalus)--46.
(E) Bryde's whale (Balaenoptera edeni)--64.
(ii) Odontocetes:
(A) Sperm whales (Physeter macrocephalus)--781.
(B) Pygmy sperm whales (Kogia breviceps)--865.
(C) Dwarf sperm whale (Kogia sima)--2122.
(D) Cuvier's beaked whale (Ziphius cavirostris)--1149.
(E) Blainville's beaked whale (Mesoplodon densirostris)--357.
(F) Longman's beaked whale (Indopacetus pacificus)--105.
(G) Rough-toothed dolphin (Steno bredanensis)--1077.
(H) Bottlenose dolphin (Tursiops truncatus)--734.
(I) Pan-tropical dolphins (Stenella attenuata)--2199.
(J) Spinner dolphins (Stenella longirostris)--421.
(K) Striped dolphins (Stenella coeruleoalba).--3209.
(L) Risso's dolphin (Grampus griseus)--497.
(M) Melon-headed whale (Peponocephala electra)--597.
(N) Fraser's dolphin (Lagenodelphis hosei)--1247.
(O) Pygmy killer whale (Feresa attenuata)--196.
(P) False killer whale (Pseudorca crassidens)--46.
(Q) Killer whale (Orcinus orca)--46.
(R) Short-finned pilot whale (Globicephala macrorynchus)--1,798.
(iii) Pinnipeds: Hawaiian monk seal (Monachus schauinslandi)--110.
(2) Level A Harassment and/or mortality of no more than 10
individuals total of each of the species listed below over the course
of the 5-year regulations: Bottlenose dolphin (Tursiops truncatus),
Pygmy and Dwarf sperm whales (Kogia breviceps and sima), Melon-headed
whale (Peponocephala electra), Pantropical spotted dolphin (Stenella
attenuata), Pygmy killer whale (Feresa attenuata), Short-finned pilot
whale (Globicephala macrorynchus), Striped dolphin (Stenella
coeruleoalba), and Cuvier's beaked whale (Ziphius cavirostris),
Blainville's beaked whale, (Mesoplodon densirostris), Longman's beaked
whale (Indopacetus pacificus).
Sec. 216.173 Prohibitions.
Notwithstanding takings contemplated in Sec. 216.172 and
authorized by a Letter of Authorization issued under Sec. Sec. 216.106
and 216.177, no person in connection with the activities described in
Sec. 216.170 may:
(a) Take any marine mammal not specified in Sec. 216.172(c);
(b) Take any marine mammal specified in Sec. 216.172(c) other than
by incidental take as specified in Sec. 216.172(c)(1) and (2);
(c) Take a marine mammal specified in Sec. 216.172(c) 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 these regulations or a Letter of Authorization issued
under Sec. Sec. 216.106 and 216.177.
Sec. 216.174 Mitigation.
(a) The activity identified in Sec. 216.170(a) must be conducted
in a manner that minimizes, to the greatest extent practicable, adverse
impacts on marine mammals and their habitats. When conducting training
activities identified in Sec. 216.170(a), the mitigation measures
contained in the Letter of Authorization issued under Sec. Sec.
216.106 and 216.177 must be implemented. These mitigation measures
include (but are not limited to):
(1) Mitigation Measures for ASW training: (i) All lookouts onboard
platforms involved in ASW training events will review the NMFS-approved
Marine Species Awareness Training (MSAT) material prior to use of mid-
frequency active sonar.
(ii) All Commanding Officers, Executive Officers, and officers
standing watch on the Bridge will have reviewed the MSAT material prior
to a training event employing the use of mid-frequency active sonar.
(iii) Navy lookouts will undertake extensive training in order to
qualify as a watchstander in accordance with the Lookout Training
Handbook (NAVEDTRA, 12968-B).
(iv) Lookout training will include on-the-job instruction under the
supervision of a qualified, experienced watchstander. Following
successful completion of this supervised training period, Lookouts will
complete the Personal Qualification Standard program, certifying that
they have demonstrated the necessary skills (such as detection and
reporting of partially submerged objects).
(v) Lookouts will be trained in the most effective means to ensure
quick and effective communication within the command structure in order
to facilitate implementation of mitigation measures if marine species
are spotted.
(vi) On the bridge of surface ships, there will always be at least
three people on watch whose duties include observing the water surface
around the vessel.
(vii) All surface ships participating in ASW exercises will, in
addition to the three personnel on watch noted previously, have at all
times during the exercise at least two additional personnel on watch as
lookouts.
(viii) Personnel on lookout and officers on watch on the bridge
will have at least one set of binoculars available for each person to
aid in the detection of marine mammals.
(ix) On surface vessels equipped with mid-frequency active sonar,
pedestal mounted ``Big Eye'' (20x110) binoculars will be present and in
good working order.
(x) Personnel on lookout will employ visual search procedures
employing a scanning methodology in accordance with the Lookout
Training Handbook (NAVEDTRA 12968-B).
(xi) After sunset and prior to sunrise, lookouts will employ Night
Lookouts Techniques in accordance with the Lookout Training Handbook.
(xii) Personnel on lookout will be responsible for reporting all
objects or anomalies sighted in the water (regardless of the distance
from the vessel) to the Officer of the Deck.
(xiii) A Letter of Instruction, Mitigation Measures Message or
Environmental Annex to the Operational Order will be issued prior to
each exercise to further disseminate the personnel training requirement
and general marine mammal mitigation measures.
(xiv) Commanding Officers will make use of marine species detection
cues and information to limit interaction with marine species to the
maximum extent possible consistent with safety of the ship.
(xv) All personnel engaged in passive acoustic sonar operation
(including aircraft, surface ships, or submarines) will monitor for
marine mammal vocalizations and report the detection of any marine
mammal to the appropriate watch station for dissemination and
appropriate action.
[[Page 35572]]
(xvi) During mid-frequency active sonar training activities,
personnel will utilize all available sensor and optical systems (such
as Night Vision Goggles) to aid in the detection of marine mammals.
(xvii) Navy aircraft participating in exercises at sea will conduct
and maintain, when operationally feasible and safe, surveillance for
marine species of concern as long as it does not violate safety
constraints or interfere with the accomplishment of primary operational
duties.
(xviii) Aircraft with deployed sonobuoys will use only the passive
capability of sonobuoys when marine mammals are detected within 200
yards (182 m) of the sonobuoy.
(xix) Marine mammal detections will be immediately reported to
assigned Aircraft Control Unit for further dissemination to ships in
the vicinity of the marine species as appropriate where it is
reasonable to conclude that the course of the ship will likely result
in a closing of the distance to the detected marine mammal.
(xx) Safety Zones--When marine mammals are detected by any means
(aircraft, shipboard lookout, or acoustically) the Navy will ensure
that MFA transmission levels are limited to at least 6 dB below normal
operating levels if any detected marine mammals are within 1,000, yards
(914 m) of the sonar dome (the bow).
(A) Ships and submarines will continue to limit maximum MFAS
transmission levels by this 6-dB factor until the marine mammal has
been seen to leave the area, has not been detected for 30 minutes, or
the vessel has transited more than 2,000 yards (1828 m) beyond the
location of the last detection.
(B) The Navy will ensure that MFAS transmissions will be limited to
at least 10 dB below the equipment's normal operating level if any
detected animals are within 500 yards (457 m) of the sonar dome. Ships
and submarines will continue to limit maximum ping levels by this 10-dB
factor until the marine mammal has been seen to leave the area, has not
been detected for 30 minutes, or the vessel has transited more than
2,000 yards (1828 m) beyond the location of the last detection.
(C) The Navy will ensure that MFAS transmissions are ceased if any
detected marine mammals are within 200 yards of the sonar dome. MFAS
transmissions will not resume until the marine mammal has been seen to
leave the area, has not been detected for 30 minutes, or the vessel has
transited more than 2,000 yards beyond the location of the last
detection.
(D) Special conditions applicable for dolphins and porpoises only:
If, after conducting an initial maneuver to avoid close quarters with
dolphins or porpoises, the Officer of the Deck concludes that dolphins
or porpoises are deliberately closing to ride the vessel's bow wave, no
further mitigation actions are necessary while the dolphins or
porpoises continue to exhibit bow wave riding behavior.
(E) If the need for power-down should arise as detailed in ``Safety
Zones'' above, Navy shall follow the requirements as though they were
operating at 235 dB--the normal operating level (i.e., the first power-
down will be to 229 dB, regardless of at what level above 235 sonar was
being operated).
(xxi) Prior to start up or restart of active sonar, operators will
check that the Safety Zone radius around the sound source is clear of
marine mammals.
(xxii) Sonar levels (generally)--Navy will operate sonar at the
lowest practicable level, not to exceed 235 dB, except as required to
meet tactical training objectives.
(xxiii) Helicopters shall observe/survey the vicinity of an ASW
Operation for 10 minutes before the first deployment of active
(dipping) sonar in the water.
(xxiv) Helicopters shall not dip their sonar within 200 yards (183
m) of a marine mammal and shall cease pinging if a marine mammal closes
within 200 yards (183 m) after pinging has begun.
(xxv) Submarine sonar operators will review detection indicators of
close-aboard marine mammals prior to the commencement of ASW training
activities involving active mid-frequency sonar.
(xxvi) Humpback Whale Cautionary Area: An area extending 5 km (2.7
nm) from a line drawn from Kaunakakai on the island of Molokai to Kaena
Point on the Island of Lanai; and an area extending 5 km (2.7 nm) from
a line drawn from Kaunolu on the Island of Lanai to the most
Northeastern point on the Island of Kahoolawe; and within a line drawn
from Kanapou Bay on the Island of Kahoolawe to Kanahena Point on the
Island of Maui and a line drawn from Cape Halawa on the Island of
Molokai to Lipo Point on the Island of Maui, excluding the existing
submarine operating area.
(A) Should national security needs require MFA sonar training and
testing in the cautionary area between 15 December and 15 April, it
must be personally authorized by the Commander, U.S. Pacific Fleet
based on his determination that training and testing in that specific
area is required for national security purposes. This authorization
shall be documented by the CPF in advance of transiting and training in
the cautionary area, and the determination shall be based on the unique
characteristics of the area from a military readiness perspective,
taking into account the importance of the area for humpback whales and
the need to minimize adverse impacts on humpback whales from MFA sonar
whenever practicable. Further, Commander, U.S. Pacific Fleet will
provide specific direction on required mitigation measures prior to
operational units transiting to and training in the cautionary area.
(B) The Navy will provide advance notification to NMFS of any such
activities (listed in paragraph (a)(1)(xxvi)(A) of this section).
(C) The Navy will include in its periodic reports for compliance
with the MMPA whether or not activities occurred in the Humpback
Cautionary Area above and any observed effects on humpback whales due
to the conduct of these activities.
(xxvii) The Navy will abide by the letter of the ``Stranding
Response Plan for Major Navy Training Exercises in the HRC'' (available
at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm), to include the
following measures:
(A) Shutdown Procedures--When an Uncommon Stranding Event (USE--
defined in Sec. 216.171) occurs during a Major Training Exercise (MTE,
including RIMPAC, USWEX, or Multi-Strike Group Exercise) in the HRC,
the Navy will implement the procedures described below.
(1) The Navy will implement a Shutdown (as defined in Sec.
216.171) when advised by a NMFS Office of Protected Resources
Headquarters Senior Official designated in the HRC Stranding
Communication Protocol that a USE involving live animals has been
identified and that at least one live animal is located in the water.
NMFS and Navy will maintain a dialogue, as needed, regarding the
identification of the USE and the potential need to implement shutdown
procedures.
(2) Any shutdown in a given area will remain in effect in that area
until NMFS advises the Navy that the subject(s) of the USE at that area
die or are euthanized, or that all live animals involved in the USE at
that area have left the area (either of their own volition or herded).
(3) If the Navy finds an injured or dead animal floating at sea
during an MTE, the Navy shall notify NMFS immediately or as soon as
operational
[[Page 35573]]
security considerations allow. The Navy will provide NMFS with species
or description of the animal(s), the condition of the animal(s)
including carcass condition if the animal(s) is/are dead), location,
time of first discovery, observed behaviors (if alive), and photo or
video (if available). Based on the information provided, NMFS will
determine if, and advise the Navy whether a modified shutdown is
appropriate on a case-by-case basis.
(4) In the event, following a USE, that: qualified individuals are
attempting to herd animals back out to the open ocean and animals are
not willing to leave, or animals are seen repeatedly heading for the
open ocean but turning back to shore, NMFS and the Navy will coordinate
(including an investigation of other potential anthropogenic stressors
in the area) to determine if the proximity of MFAS training activities
or explosive detonations, though farther than 14 nm from the distressed
animal(s), is likely decreasing the likelihood that the animals return
to the open water. If so, NMFS and the Navy will further coordinate to
determine what measures are necessary to further minimize that
likelihood and implement those measures as appropriate.
(B) Within 72 hours of NMFS notifying the Navy of the presence of a
USE, the Navy will provide available information to NMFS (per the HRC
Communication Protocol) regarding the location, number and types of
acoustic/explosive sources, direction and speed of units using MFAS,
and marine mammal sightings information associated with training
activities occurring within 80 nm (148 km) and 72 hours prior to the
USE event. Information not initially available regarding the 80 nm (148
km), 72 hours, period prior to the event will be provided as soon as it
becomes available. The Navy will provide NMFS investigative teams with
additional relevant unclassified information as requested, if
available.
(C) Memorandum of Agreement (MOA)--The Navy and NMFS will develop
an MOA, or other mechanism consistent with federal fiscal law
requirements (and all other applicable laws), that allows the Navy to
assist NMFS with the Phase 1 and 2 Investigations of USEs through the
provision of in-kind services, such as (but not limited to) the use of
plane/boat/truck for transport of stranding responders or animals, use
of Navy property for necropsies or burial, or assistance with aerial
surveys to discern the extent of a USE. The Navy may assist NMFS with
the Investigations by providing one or more of the in-kind services
outlined in the MOA, when available and logistically feasible and when
the assistance does not negatively affect Fleet operational
commitments.
(2) Mitigation for IEER--The following are protective measures for
use with Extended Echo Ranging/Improved Extended Echo Ranging (EER/
IEER) given an explosive source generates the acoustic wave used in
this sonobuoy.
(i) Crews will conduct visual reconnaissance of the drop area prior
to laying their intended sonobuoy pattern. This search should be
conducted below 500 yards (457 m) at a slow speed, if operationally
feasible and weather conditions permit. In dual aircraft training
activities, crews are allowed to conduct coordinated area clearances.
(ii) Crews shall conduct a minimum of 30 minutes of visual and
acoustic monitoring of the search area prior to commanding the first
post detonation. This 30-minute observation period may include pattern
deployment time.
(iii) For any part of the briefed pattern where a post (source/
receiver sonobuoy pair) will be deployed within 1,000 yards (914 m) of
observed marine mammal activity, deploy the receiver ONLY and monitor
while conducting a visual search. When marine mammals are no longer
detected within 1,000 yards (914 m) of the intended post position, co-
locate the explosive source sonobuoy (AN/SSQ-110A) (source) with the
receiver.
(iv) When able, crews will conduct continuous visual and aural
monitoring of marine mammal activity. This is to include monitoring of
own-aircraft sensors from first sensor placement to checking off
station and out of communication range of these sensors.
(v) Aural Detection: If the presence of marine mammals is detected
aurally, then that should cue the aircrew to increase the diligence of
their visual surveillance. Subsequently, if no marine mammals are
visually detected, then the crew may continue multi-static active
search.
(vi) Visual Detection:
(A) If marine mammals are visually detected within 1,000 yards (914
m) of the explosive source sonobuoy (AN/SSQ-110A) intended for use,
then that payload shall not be detonated. Aircrews may utilize this
post once the marine mammals have not been re-sighted for 30 minutes,
or are observed to have moved outside the 1,000 yards (914 m) safety
buffer.
(B) Aircrews may shift their multi-static active search to another
post, where marine mammals are outside the 1,000 yards (914 m) safety
buffer.
(vii) Aircrews shall make every attempt to manually detonate the
unexploded charges at each post in the pattern prior to departing the
operations area by using the ``Payload 1 Release'' command followed by
the ``Payload 2 Release'' command. Aircrews shall refrain from using
the ``Scuttle'' command when two payloads remain at a given post.
Aircrews will ensure that a 1,000 yard (914 m) safety buffer, visually
clear of marine mammals, is maintained around each post as is done
during active search operations.
(viii) Aircrews shall only leave posts with unexploded charges in
the event of a sonobuoy malfunction, an aircraft system malfunction, or
when an aircraft must immediately depart the area due to issues such as
fuel constraints, inclement weather, and in-flight emergencies. In
these cases, the sonobuoy will self-scuttle using the secondary or
tertiary method.
(ix) Ensure all payloads are accounted for. Explosive source
sonobuoys (AN/SSQ-110A) that cannot be scuttled shall be reported as
unexploded ordnance via voice communications while airborne, then upon
landing via naval message.
(x) Mammal monitoring shall continue until out of own-aircraft
sensor range.
(3) Mitigation for Demolitions (DEMOs) and Mine Countermeasure
(MCM) Training (Up to 20 lb). (i) Exclusion Zones--Explosive charges
will not be detonated if a marine mammal is detected within 700 yards
(640 m) of the detonation site.
(ii) Pre-Exercise Surveys--For MCM training activities, the Navy
will conduct a pre-exercise survey within 30 minutes prior to the
commencement of the scheduled explosive event. The survey may be
conducted from the surface, by divers, and/or from the air. If a marine
mammal is detected within the survey area, the exercise shall be
suspended until the animal voluntarily leaves the area.
(iii) Post-Exercise Surveys--Surveys within the same radius shall
also be conducted within 30 minutes after the completion of the
explosive event.
(iv) Reporting--Any evidence of a marine mammal that may have been
injured or killed by the action shall be reported immediately to NMFS.
(v) Mine Laying Training--Though mine laying training operations
involve aerial drops of inert training shapes on floating targets,
measures 1, 2, and 3 for Demolitions and Mine countermeasures (above)
will apply to mine laying training. To the maximum extent feasible, the
Navy shall retrieve inert mine shapes dropped during Mine Laying
Training.
[[Page 35574]]
(4) Mitigation for SINKEX, GUNEX, MISSILEX, and BOMBEX. (i) All
weapons firing would be conducted during the period 1 hour after
official sunrise to 30 minutes before official sunset.
(ii) Extensive range clearance operations would be conducted in the
hours prior to commencement of the exercise, ensuring that no shipping
is located within the hazard range of the longest-range weapon being
fired for that event.
(iii) Prior to conducting the exercise, remotely sensed sea surface
temperature maps would be reviewed. SINKEX and air to surface missile
(ASM) Training activities would not be conducted within areas where
strong temperature discontinuities are present, thereby indicating the
existence of oceanographic fronts. These areas would be avoided because
concentrations of some listed species, or their prey, are known to be
associated with these oceanographic features.
(iv) An exclusion zone with a radius of 1.0 nm (1.85 km) would be
established around each target. This exclusion zone is based on
calculations using a 449 kg H6 NEW high explosive source detonated 5
feet below the surface of the water, which yields a distance of 0.85 nm
(1.57 km) (cold season) and 0.89 nm (1.64 km) (warm season) beyond
which the received level is below the 182 dB re: 1 Pa sec2 threshold
established for the WINSTON S. CHURCHILL (DDG 81) shock trials. An
additional buffer of 0.5 nm (0.93 km) would be added to account for
errors, target drift, and animal movements. Additionally, a safety
zone, which extends from the exclusion zone at 1.0 nm (1.85 km) out an
additional 0.5 nm (0.93 km), would be surveyed. Together, the zones
extend out 2 nm (3.7 km) from the target.
(v) A series of surveillance over-flights would be conducted within
the exclusion and the safety zones, prior to and during the exercise,
when feasible. Survey protocol would be as follows:
(A) Overflights within the exclusion zone would be conducted in a
manner that optimizes the surface area of the water observed. This may
be accomplished through the use of the Navy's Search and Rescue (SAR)
Tactical Aid (TACAID). The SAR TACAID provides the best search
altitude, ground speed, and track spacing for the discovery of small,
possibly dark objects in the water based on the environmental
conditions of the day. These environmental conditions include the angle
of sun inclination, amount of daylight, cloud cover, visibility, and
sea state.
(B) All visual surveillance activities would be conducted by Navy
personnel trained in visual surveillance. At least one member of the
mitigation team would have completed the Navy's marine mammal training
program for lookouts.
(C) In addition to the overflights, the exclusion zone would be
monitored by passive acoustic means, when assets are available. This
passive acoustic monitoring would be maintained throughout the
exercise. Potential assets include sonobuoys, which can be utilized to
detect any vocalizing marine mammals in the vicinity of the exercise.
The sonobuoys would be re-seeded as necessary throughout the exercise.
Additionally, passive sonar onboard submarines may be utilized to
detect any vocalizing marine mammals in the area. The OCE would be
informed of any aural detection of marine mammals and would include
this information in the determination of when it is safe to commence
the exercise.
(D) On each day of the exercise, aerial surveillance of the
exclusion and safety zones would commence two hours prior to the first
firing.
(E) The results of all visual, aerial, and acoustic searches would
be reported immediately to the OCE (Officer Conducting the Exercise).
No weapons launches or firing would commence until the OCE declares the
safety and exclusion zones free of marine mammals.
(F) If a marine mammal observed within the exclusion zone is
diving, firing would be delayed until the animal is re-sighted outside
the exclusion zone, or 30 minutes has elapsed. After 30 minutes, if the
animal has not been re-sighted it would be assumed to have left the
exclusion zone and firing would commence.
(G) During breaks in the exercise of 30 minutes or more, the
exclusion zone would again be surveyed for any marine mammals. If
marine mammals are sighted within the exclusion zone, the OCE would be
notified, and the procedure described above would be followed.
(H) Upon sinking of the vessel, a final surveillance of the
exclusion zone would be monitored for two hours, or until sunset, to
verify that no marine mammals were harmed.
(vi) Aerial surveillance would be conducted using helicopters or
other aircraft based on necessity and availability. The Navy has
several types of aircraft capable of performing this task; however, not
all types are available for every exercise. For each exercise, the
available asset best suited for identifying objects on and near the
surface of the ocean would be used. These aircraft would be capable of
flying at the slow safe speeds necessary to enable viewing of marine
mammals with unobstructed, or minimally obstructed, downward and
outward visibility. The exclusion and safety zone surveys may be
cancelled in the event that a mechanical problem, emergency search and
rescue, or other similar and unexpected event preempts the use of one
of the aircraft onsite for the exercise.
(vii) Every attempt would be made to conduct the exercise in sea
states that are ideal for marine mammal sighting, Beaufort Sea State 3
or less. In the event of a 4 or above, survey efforts would be
increased within the zones. This would be accomplished through the use
of an additional aircraft, if available, and conducting tight search
patterns.
(viii) The exercise would not be conducted unless the exclusion
zone could be adequately monitored visually.
(ix) In the unlikely event that any marine mammals are observed to
be harmed in the area, a detailed description of the animal would be
documented, the location noted, and if possible, photos taken. This
information would be provided to NMFS.
(b) [Reserved]
Sec. 216.175 Requirements for monitoring and reporting.
(a) The Holder of the Letter of Authorization issued pursuant to
Sec. Sec. 216.106 and 216.177 for activities described in Sec.
216.170(b) is required to cooperate with the NMFS, and any other
Federal, state or local agency monitoring the impacts of the activity
on marine mammals.
(b) As outlined in the HRC Stranding Communication Plan, the Holder
of the Authorization must notify NMFS immediately (or as soon as
clearance procedures allow) if the specified activity identified in
Sec. 216.170(b) is thought to have resulted in the mortality or injury
of any marine mammals, or in any take of marine mammals not identified
in Sec. 216.170(c).
(c) The Holder of the Letter of Authorization must conduct all
monitoring and/or research required under the Letter of Authorization
including abiding by the letter of the HRC Monitoring Plan, which
requires the Navy implement, at a minimum, the monitoring activities
summarized in Table 1 to this subpart (and described in more detail in
the HRC Monitoring Plan, which may be viewed at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm).
(d) Report from Monitoring required in paragraph (c) of this
section--The
[[Page 35575]]
Navy will submit a report annually on September 1 describing the
implementation and results (through June 1 of the same year) of the
monitoring required in paragraph (c) of this section. Standard marine
species sighting forms will be use to standardize data collection and
data collection methods will be standardized across ranges to allow for
comparison in different geographic locations.
(e) SINKEX, GUNEX, MISSILEX, BOMBEX, and IEER exercises--A report
detailing the timelines of the exercises conducted, the time the
surveys commenced and terminated, amount and types of all ordnance
expended, and the results of survey efforts for each event will be
submitted to NMFS yearly.
(f) MFAS/HFAS exercises--The Navy will submit an After Action
Report to the Office of Protected Resources, NMFS, within 120 days of
the completion of any Major Training Exercise (RIMPAC, USWEX, and Multi
Strike Group). For other ASW exercises (TRACKEX and TORPEX), the Navy
will submit a yearly summary report. These reports will, at a minimum,
include the following information:
(1) The estimated number of hours of sonar operation, broken down
by source type
(2) If possible, the total number of hours of observation effort
(including observation time when sonar was not operating)
(3) A report of all marine mammal sightings (at any distance--not
just within a particular distance) to include, when possible, and if
not classified:
(i) Species.
(ii) Number of animals sighted.
(iii) Geographic location of marine mammal sighting.
(iv) Distance of animal from any ship with observers.
(v) Whether animal is fore, aft, port, or starboard.
(vi) Direction of animal movement in relation to boat (towards,
away, parallel).
(vii) Any observed behaviors of marine mammals.
(4) The status of any sonar sources (what sources were in use) and
whether or not they were powered down or shut down as a result of the
marine mammal observation.
(5) The platform that the marine mammals were sighted from.
(g) HRC Comprehensive Report--The Navy will submit to NMFS a draft
report that analyzes and summarizes all of the multi-year marine mammal
information gathered during ASW and explosive exercises for which
individual reports are required in Sec. 216.175 (d) through (f) of
this section. This report will be submitted at the end of the fourth
year of the rule (November 2012), covering activities that have
occurred through June 1, 2012.
(h) The Navy will respond to NMFS comments on the draft
comprehensive report if submitted within 3 months of receipt. The
report will be considered final after the Navy has addressed NMFS'
comments, or three months after the submittal of the draft if NMFS does
not comment by then.
(i) Comprehensive National ASW Report--The Navy will submit a draft
National Report that analyzes, compares, and summarizes the data
gathered from the watchstanders and pursuant to the implementation of
the Monitoring Plans for the HRC, the Atlantic Fleet active Sonar
Training (AFAST), and the Southern California (SOCAL) Range Complex.
(j) The Navy will respond to NMFS comments on the draft
comprehensive report if submitted within 3 months of receipt. The
report will be considered final after the Navy has addressed NMFS'
comments, or three months after the submittal of the draft if NMFS does
not comment by then.
Sec. 216.176 Applications for Letters of Authorization.
To incidentally take marine mammals pursuant to these regulations,
the U.S. citizen (as defined by Sec. 216.103) conducting the activity
identified in Sec. 216.170(a) (the U.S. Navy) must apply for and
obtain either an initial Letter of Authorization in accordance with
Sec. Sec. 216.177 or a renewal under Sec. 216.178.
Sec. 216.177 Letter of Authorization.
(a) A Letter of Authorization, unless suspended or revoked, will be
valid for a period of time not to exceed the period of validity of this
subpart, but must be renewed annually subject to annual renewal
conditions in Sec. 216.178.
(b) Each Letter of Authorization will set forth:
(1) Permissible methods of incidental taking;
(2) Means of effecting the least practicable adverse impact on the
species, its habitat, and on the availability of the species for
subsistence uses ( i.e., mitigation); and
(3) Requirements for mitigation, monitoring and reporting.
(c) Issuance and renewal of the Letter of Authorization will be
based on a determination that the total number of marine mammals taken
by the activity as a whole will have no more than a negligible impact
on the affected species or stock of marine mammal(s).
Sec. 216.178 Renewal of Letters of Authorization.
(a) A Letter of Authorization issued under Sec. 216.106 and Sec.
216.177 for the activity identified in Sec. 216.170(c) will be renewed
annually upon:
(1) Notification to NMFS that the activity described in the
application submitted under Sec. 216.176 will be undertaken and that
there will not be a substantial modification to the described work,
mitigation or monitoring undertaken during the upcoming 12 months;
(2) Timely receipt of the monitoring reports required under Sec.
216.175(b); and
(3) A determination by the NMFS that the mitigation, monitoring and
reporting measures required under Sec. 216.174 and the Letter of
Authorization issued under Sec. Sec. 216.106 and 216.177, were
undertaken and will be undertaken during the upcoming annual period of
validity of a renewed Letter of Authorization.
(b) If a request for a renewal of a Letter of Authorization issued
under Sec. Sec. 216.106 and 216.178 indicates that a substantial
modification to the described work, mitigation or monitoring undertaken
during the upcoming season will occur, the NMFS will provide the public
a period of 30 days for review and comment on the request. Review and
comment on renewals of Letters of Authorization are restricted to:
(1) New cited information and data indicating that the
determinations made in this document are in need of reconsideration,
and
(2) Proposed changes to the mitigation and monitoring requirements
contained in this subpart or in the current 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.
Sec. 216.179 Modifications to Letters of Authorization.
(a) Except as provided in paragraph (b) of this section, no
substantive modification (including withdrawal or suspension) to the
Letter of Authorization by NMFS, issued pursuant to Sec. Sec. 216.106
and 216.177 and subject to the provisions of this subpart shall be made
until after notification and an opportunity for public comment has been
provided. For purposes of this paragraph, a renewal of a Letter of
Authorization under Sec. 216.178, without modification (except for the
period of validity), is not considered a substantive modification.
(b) If the Assistant Administrator determines that an emergency
exists
[[Page 35576]]
that poses a significant risk to the well-being of the species or
stocks of marine mammals specified in Sec. 216.170(b), a Letter of
Authorization issued pursuant to Sec. Sec. 216.106 and 216.177 may be
substantively modified without prior notification and an opportunity
for public comment. Notification will be published in the Federal
Register within 30 days subsequent to the action.
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