[Federal Register Volume 78, Number 21 (Thursday, January 31, 2013)]
[Proposed Rules]
[Pages 6978-7048]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-01808]
[[Page 6977]]
Vol. 78
Thursday,
No. 21
January 31, 2013
Part III
Department of Commerce
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National Oceanic and Atmospheric Administration
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50 CFR Part 218
Takes of Marine Mammals Incidental to Specified Activities; U.S. Navy
Training and Testing Activities in the Hawaii-Southern California
Training and Testing Study Area; Proposed Rule
Federal Register / Vol. 78, No. 21 / Thursday, January 31, 2013 /
Proposed Rules
[[Page 6978]]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 218
[Docket No. 130107014-3024-01]
RIN 0648-BC52
Takes of Marine Mammals Incidental to Specified Activities; U.S.
Navy Training and Testing Activities in the Hawaii-Southern California
Training and Testing Study Area
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Proposed rule; request for comments and information.
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SUMMARY: NMFS has received a request from the U.S. Navy (Navy) for
authorization to take marine mammals incidental to the training and
testing activities conducted in the Hawaii-Southern California Training
and Testing (HSTT) study area from January 2014 through January 2019.
Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting
comments on its proposal to issue regulations and subsequent Letters of
Authorization (LOAs) to the Navy to incidentally harass marine mammals.
DATES: Comments and information must be received no later than March
11, 2013.
ADDRESSES: You may submit comments, identified by 0648-BC52, by either
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 P. Michael Payne, Chief, Permits and
Conservation 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 (enter N/A in the required
fields if you wish to remain anonymous). Attachments to electronic
comments will be accepted in Microsoft Word, Excel, WordPerfect, or
Adobe PDF file formats only.
FOR FURTHER INFORMATION CONTACT: Michelle Magliocca, Office of
Protected Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Availability
A copy of the Navy's application may be obtained by visiting the
internet at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. The Navy's Draft Environmental Impact
Statement/Overseas Environmental Impact Statement (DEIS/OEIS) for HSTT
was made available to the public on May 11, 2012 (77 FR 27743) and may
also be viewed at http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. Documents cited in this notice may also be
viewed, by appointment, during regular business hours, at the
aforementioned address.
Background
Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)
direct the Secretary of Commerce to allow, upon request, the
incidental, but not intentional, taking of small numbers of marine
mammals by U.S. citizens who engage in a specified activity (other than
commercial fishing) within a specified geographical region if certain
findings are made and either regulations are issued or, if the taking
is limited to harassment, a notice of a proposed authorization is
provided to the public for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s), will not have an unmitigable adverse impact on the
availability of the species or stock(s) for subsistence uses (where
relevant), and if the permissible methods of taking and requirements
pertaining to the mitigation, monitoring, and reporting of such takings
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103
as ``an impact resulting from the specified activity that cannot be
reasonably expected to, and is not reasonably likely to, adversely
affect the species or stock through effects on annual rates of
recruitment or survival.''
The National Defense Authorization Act of 2004 (NDAA) (Pub. L. 108-
136) removed the ``small numbers'' and ``specified geographical
region'' limitations indicated above and amended the definition of
``harassment'' as 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 April 13, 2012, NMFS received an application from the Navy
requesting two LOAs for the take of 39 species of marine mammals
incidental to Navy training and testing activities to be conducted in
the HSTT Study Area over 5 years. The Navy submitted an addendum on
September 24, 2012 and the application was considered complete. The
Navy is requesting regulations that would establish a process for
authorizing take, via two separate 5-year LOAs, of marine mammals for
training activities and testing activities, each proposed to be
conducted from 2014 through 2019. The Study Area includes three
existing range complexes (Southern California (SOCAL) Range Complex,
Hawaii Range Complex (HRC), and Silver Strand Training Complex (SSTC))
plus pierside locations and areas on the high seas where maintenance,
training, or testing may occur. The proposed activities are classified
as military readiness activities. Marine mammals present in the Study
Area may be exposed to sound from active sonar, underwater detonations,
and/or pile driving and removal. In addition, incidental takes of
marine mammals may occur from ship strikes. The Navy is requesting
authorization to take 38 marine mammal species by Level B harassment
and 24 marine mammal species by Level A harassment or mortality.
The Navy's application and the HSTT DEIS/OEIS contain proposed
acoustic criteria and thresholds that would, in some instances,
represent changes from what NMFS has used to evaluate the Navy's
proposed activities for past incidental take authorizations. The
revised thresholds are based on evaluation of recent scientific
studies; a detailed explanation of how they were derived is provided in
the HSTT DEIS/OEIS Criteria and Thresholds Technical Report. NMFS is
currently updating and revising all of its acoustic criteria and
thresholds. Until that process is complete, NMFS will continue its
long-standing practice of considering specific
[[Page 6979]]
modifications to the acoustic criteria and thresholds currently
employed for incidental take authorizations only after providing the
public with an opportunity for review and comment. NMFS is requesting
comments on all aspects of the proposed rule, and specifically requests
comments on the proposed acoustic criteria and thresholds.
Background of 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. Section 5062 of Title 10 of the United
States Code directs the Chief of Naval Operations to train all military
forces for combat. The Chief of Naval Operations meets that direction,
in part, 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, testing, and evaluation (RDT&E) of naval
systems.
The Navy proposes to continue conducting training and testing
activities within the HSTT Study Area, which have been ongoing since
the 1940s. Recently, most of these activities were analyzed in three
separate EISs completed between 2008 and 2011; the Hawaii Range Complex
(HRC) EIS/OEIS (U.S. Department of the Navy, 2008a), the Southern
California (SOCAL) Range Complex EIS/OEIS (U.S. Department of the Navy,
2008b), and the Silver Strand Training Complex (SSTC) EIS (U.S.
Department of the Navy, 2011a). These documents, among others, and
their associated MMPA regulations and authorizations, describe the
baseline of training and testing activities currently conducted in the
Study Area. The tempo and types of training and testing activities have
fluctuated due to changing requirements; new technologies; the dynamic
nature of international events; advances in warfighting doctrine and
procedures; and changes in basing locations for ships, aircraft, and
personnel. Such developments influence the frequency, duration,
intensity, and location of required training and testing. The Navy's
LOA request covers training and testing activities that would occur for
a 5-year period following the expiration of the current MMPA
authorizations. The Navy has also prepared a DEIS/OEIS analyzing the
effects on the human environment of implementing their preferred
alternative (among others).
Description of the Specified Activity
The Navy is requesting authorization to take marine mammals
incidental to conducting training and testing activities. The Navy has
determined that sonar use, underwater detonations, pile driving and
removal, and ship strike are the stressors most likely to result in
impacts on marine mammals that could rise to the level of harassment.
Detailed descriptions of these activities are provided in the HSTT
DEIS/OEIS and LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental.htm) and are summarized here.
Overview of Training Activities
The Navy routinely trains in the HSTT Study Area in preparation for
national defense missions. Training activities are categorized into
eight functional warfare areas (anti-air warfare; amphibious warfare;
strike warfare; anti-surface warfare; anti-submarine warfare;
electronic warfare; mine warfare; and naval special warfare). The Navy
determined that the following stressors used in these warfare areas are
most likely to result in impacts on marine mammals:
Amphibious warfare (underwater detonations, pile driving
and removal)
Anti-surface warfare (underwater detonations)
Anti-submarine warfare (active sonar, underwater
detonations)
Mine warfare (active sonar, underwater detonations, and
marine mammal systems (see description below))
Naval special warfare (underwater detonations)
The Navy's activities in anti-air warfare, strike warfare, and
electronic warfare do not involve stressors that could result in
harassment of marine mammals. Therefore, these activities are not
discussed further.
Amphibious Warfare
The mission of amphibious warfare is to project military power from
the sea to the shore through the use of naval firepower and Marine
Corps landing forces. The Navy uses amphibious warfare to attack a
threat located on land by a military force embarked on ships.
Amphibious warfare training ranges from individual, crew, and small
unit events to large task force exercises. Individual and crew training
include amphibious vehicles and naval gunfire support training for
shore assaults, boat raids, airfield or port seizures, and
reconnaissance. Large-scale amphibious exercises involve ship-to-shore
maneuver, naval fire support, such as shore bombardment, and air strike
and close air support training. However, the Navy only analyzed those
portions of amphibious warfare training that occur at sea, in
particular, underwater detonations associated with naval gunfire
support training. The Navy conducts other amphibious warfare support
activities that could potentially affect marine mammals (such as pile
driving and removal) in the near shore region from the beach to about
914 meters (m) from shore.
Anti-Surface Warfare
The mission of anti-surface warfare is to defend against enemy
ships or boats. When conducting anti-surface warfare, aircraft use
cannons, air-launched cruise missiles, or other precision-guided
munitions; ships use torpedoes, naval guns, and surface-to-surface
missiles; and submarines use torpedoes or submarine-launched, anti-ship
cruise missiles. Anti-surface warfare training includes surface-to-
surface gunnery and missile exercises, air-to-surface gunnery and
missile exercises, and submarine missile or exercise torpedo launch
events.
Anti-Submarine Warfare
The mission of anti-submarine warfare is to locate, neutralize, and
defeat hostile submarine threats to surface forces. Anti-submarine
warfare is based on the principle of a layered defense of surveillance
and attack aircraft, ships, and submarines all searching for hostile
submarines. These forces operate together or independently to gain
early warning and detection, and to localize, track, target, and attack
hostile submarine threats. Anti-submarine warfare training addresses
basic skills such as detection and classification of submarines,
distinguishing between sounds made by enemy submarines and those of
friendly submarines, ships, and marine life. More advanced, integrated
anti-submarine warfare training exercises are conducted in coordinated,
at-sea training events involving submarines, ships, and aircraft. This
training integrates the full spectrum of anti-submarine warfare from
detecting and tracking a submarine to attacking a target using either
exercise torpedoes or simulated weapons.
Mine Warfare
The mission of mine warfare is to detect, and avoid or neutralize
mines to protect Navy ships and submarines and to maintain free access
to ports and shipping lanes. Mine warfare also includes offensive mine
laying to gain control or deny the enemy access to sea
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space. Naval mines can be laid by ships, submarines, or aircraft. Mine
warfare training includes exercises in which ships, aircraft,
submarines, underwater vehicles, or marine mammal detection systems
search for mines. Certain personnel train to destroy or disable mines
by attaching and detonating underwater explosives to simulated mines.
Other neutralization techniques involve impacting the mine with a
bullet-like projectile or intentionally triggering the mine to
detonate.
Finally, the Navy deploys California sea lions in the HSTT Study
Area for integrated training involving two primary missions areas: To
find objects such as inert mine shapes, and to detect swimmers or other
intruders around Navy facilities such as piers. When deployed, the
animals are part of what the Navy refers to as marine mammal systems.
These systems include one or more motorized small boats, several crew
members, and a trained marine mammal. Each trained animal is deployed
under behavioral control to find the intruding swimmer or submerged
object.
Naval Special Warfare
The mission of naval special warfare is to conduct unconventional
warfare, direct action, combat terrorism, special reconnaissance,
information warfare, security assistance, counter-drug operations, and
recovery of personnel from hostile situations. Naval special warfare
operations are highly specialized and require continual and intense
training. Naval special warfare units are required to utilize a
combination of specialized training, equipment, and tactics, including
insertion and extraction operations using parachutes, submerged
vehicles, rubber boats, and helicopters; boat-to-shore and boat-to-boat
gunnery; underwater demolition training; reconnaissance; and small arms
training.
Overview of Testing Activities
The Navy researches, develops, tests, and evaluates new platforms,
systems, and technologies. Testing activities may occur independently
of or in conjunction with training activities. Many testing activities
are conducted similarly to Navy training activities and are also
categorized under one of the primary mission areas. Other testing
activities are unique and are described within their specific testing
categories. The Navy determined that stressors used during the
following testing activities are most likely to result in impacts on
marine mammals:
Naval Air Systems Command (NAVAIR) Testing
[cir] Anti-surface warfare testing (underwater detonations)
[cir] Anti-submarine warfare testing (active sonar, underwater
detonations)
[cir] Mine warfare testing (active sonar, underwater detonations)
Naval Sea Systems command (NAVSEA) Testing
[cir] New ship construction (active sonar, underwater detonations)
[cir] Life cycle activities (active sonar, underwater detonations)
[cir] Anti-surface warfare/anti-submarine warfare testing (active
sonar, underwater detonations)
[cir] Mine warfare testing (active sonar, underwater detonations)
[cir] Ship protection systems and swimmer defense testing (active
sonar, airguns)
[cir] Unmanned vehicle testing (active sonar)
[cir] Other testing (active sonar)
Space and Naval Warfare Systems Commands (SPAWAR) Testing
[cir] SPAWAR research, development, test, and evaluation (active
sonar)
Office of Naval Research (ONR) and Naval Research
Laboratory (NRL) Testing
[cir] ONR/NRL research, development, test, and evaluation (active
sonar)
Other Navy testing activities do not involve stressors that could
result in marine mammal harassment. Therefore, these activities are not
discussed further.
Naval Air Systems Command Testing (NAVAIR)
NAVAIR events include testing of new aircraft platforms, weapons,
and systems before delivery to the fleet for training activities.
NAVAIR also conducts lot acceptance testing of weapons and systems,
such as sonobuoys. In general, NAVAIR conducts its testing activities
the same way the fleet conducts its training activities. However,
NAVAIR testing activities may occur in different locations than
equivalent fleet training activities and testing of a particular system
may differ slightly from the way the fleet trains with the same system.
Anti-surface Warfare Testing--Anti-surface warfare testing includes
air-to-surface gunnery, missile, and rocket exercises. Testing is
required to ensure the equipment is fully functional for defense from
surface threats. Testing may be conducted on new guns or run rounds,
missiles, rockets, and aircraft, and also in support of scientific
research to assess new and emerging technologies. Testing events are
often integrated into training activities and in most cases the systems
are used in the same manner in which they are used for fleet training
activities.
Anti-submarine Warfare Testing--Anti-submarine warfare testing
addresses basic skills such as detection and classification of
submarines, distinguishing between sounds made by enemy submarines and
those of friendly submarines, ships, and marine life. More advanced,
integrated anti-submarine warfare testing is conducted in coordinated,
at-sea training events involving submarines, ships, and aircraft. This
testing integrates the full spectrum of anti-submarine warfare from
detecting and tracking a submarine to attacking a target using various
torpedoes and weapons.
Mine Warfare Testing--Mine warfare testing includes activities in
which aircraft detection systems are used to search for and record the
location of mines for subsequent neutralization. Mine neutralization
tests evaluate a system's effectiveness at intentionally detonating or
otherwise disabling the mine. Different mine neutralization systems are
designed to neutralize mines either at the sea surface or deployed
deeper within the water column. All components of these systems are
tested in the at-sea environment to ensure they meet mission
requirements.
Naval Sea Systems Command Testing (NAVSEA)
NAVSEA testing activities are aligned with its mission of new ship
construction, life cycle support, and other weapon systems development
and testing.
New Ship Construction Activities--Ship construction activities
include pierside testing of ship systems, tests to determine how the
ship performs at sea (sea trials), and developmental and operational
test and evaluation programs for new technologies and systems. Pierside
and at-sea testing of systems aboard a ship may include sonar, acoustic
countermeasures, radars, and radio equipment. During sea trials, each
new ship propulsion engine is operated at full power and subjected to
high-speed runs and steering tests. At-sea test firing of shipboard
weapon systems, including guns, torpedoes, and missiles, are also
conducted.
Life Cycle Activities--Testing activities are conducted throughout
the life of a Navy ship to verify performance and mission capabilities.
Sonar system testing occurs pierside during maintenance, repair, and
overhaul availabilities, and at sea immediately following most major
overhaul periods. A Combat System Ship Qualification
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Trial is conducted for new ships and for ships that have undergone
modification or overhaul of their combat systems. Radar cross signature
testing of surface ships is conducted on new vessels and periodically
throughout a ship's life to measure how detectable the ship is by
radar. Electromagnetic measurements of off-board electromagnetic
signature are also conducted for submarines, ships, and surface craft
periodically.
Other Weapon Systems Development and Testing--Numerous test
activities and technical evaluations, in support of NAVSEA's systems
development mission, often occur with fleet activities within the Study
Area. Tests within this category include, but are not limited to, anti-
surface, anti-submarine, and mine warfare, using torpedoes, sonobuoys,
and mine detection and neutralization systems.
Space and Naval Warfare Systems Command Testing (SPAWAR)
The mission of SPAWAR is to acquire, develop, deliver, and sustain
decision superiority for the warfighter at the right time and for the
right cost. SPAWAR Systems Center Pacific is the research and
development part of SPAWAR focused on developing and transitioning
technologies in the area of command, control, communications,
computers, intelligence, surveillance, and reconnaissance. SPAWAR
Systems Center Pacific conducts research, development, test, and
evaluation projects to support emerging technologies for intelligence,
surveillance, and reconnaissance; anti-terrorism and force protection;
mine countermeasures; anti-submarine warfare; oceanographic research;
remote sensing; and communications. These activities include, but are
not limited to, the testing of unmanned undersea and surface vehicles,
a wide variety of intelligence, surveillance, and reconnaissance sensor
systems, underwater surveillance technologies, and underwater
communications.
Office of Naval Research and Naval Research Laboratory Testing (ONR and
NRL)
As the Navy's science and technology provider, ONR and NRL provide
technology solutions for Navy and Marine Corps needs. ONR's mission is
to plan, foster, and encourage scientific research in recognition of
its paramount importance as related to the maintenance of future naval
power, and the preservation of national security. Further, ONR manages
the Navy's basic, applied, and advanced research to foster transition
from science and technology to higher levels of research, development,
test, and evaluation. The Ocean Battlespace Sensing Department explores
science and technology in the areas of oceanographic and meteorological
observations, modeling, and prediction in the battlespace environment;
submarine detection and classification (anti-submarine warfare); and
mine warfare applications for detecting and neutralizing mines in both
the ocean and littoral environment. ONR events include research,
development, test, and evaluation activities; surface processes
acoustic communications experiments; shallow water acoustic
communications experiments; sediment acoustics experiments; shallow
water acoustic propagation experiments; and long range acoustic
propagation experiments.
Sonar, Ordnance, Targets, and Other Systems
The Navy uses a variety of sensors, platforms, weapons, and other
devices to meet its mission. Training and testing with these systems
may introduce acoustic (sound) energy into the environment. This
section describes and organizes sonar systems, ordnance, munitions,
targets, and other systems to facilitate understanding of the
activities in which these systems are used. Underwater sound is
described as one of two types for the purposes of the Navy's
application: impulsive and non-impulsive. Underwater detonations of
explosives and other percussive events are impulsive sounds. Sonar and
similar sound producing systems are categorized as non-impulsive sound
sources.
Sonar and Other Non-impulsive Sources--Modern sonar technology
includes a variety of sonar sensor and processing systems. The simplest
active sonar emits sound waves, or ``pings,'' sent out in multiple
directions and the sound waves then reflect off of the target object in
multiple directions. The sonar source calculates the time it takes for
the reflected sound waves to return; this calculation determines the
distance to the target object. More sophisticated active sonar systems
emit a ping and then rapidly scan or listen to the sound waves in a
specific area. This provides both distance to the target and
directional information. Even more advanced sonar systems use multiple
receivers to listen to echoes from several directions simultaneously
and provide efficient detection of both direction and distance. The
Navy rarely uses active sonar continuously throughout activities. When
sonar is in use, the pings occur at intervals, referred to as a duty
cycle, and the signals themselves are very short in duration. For
example, sonar that emits a 1-second ping every 10 seconds has a 10-
percent duty cycle. The Navy utilizes sonar systems and other acoustic
sensors in support of a variety of mission requirements. Primary uses
include the detection of and defense against submarines (anti-submarine
warfare) and mines (mine warfare); safe navigation and effective
communications; use of unmanned undersea vehicles; and oceanographic
surveys.
Ordnance and Munitions--Most ordnance and munitions used during
training and testing events fall into three basic categories:
Projectiles (such as gun rounds), missiles (including rockets), and
bombs. Ordnance can be further defined by their net explosive weight,
which considers the type and quantity of the explosive substance
without the packaging, casings, bullets, etc. Net explosive weight
(NEW) is the trinitrotoluene (TNT) equivalent of energetic material,
which is the standard measure of strength of bombs and other
explosives. For example, a 12.7-centimeter(cm) shell fired from a Navy
gun is analyzed at about 9.5 pounds (lb) (4.3 kilograms (kg)) of NEW.
The Navy also uses non-explosive ordnance in place of high explosive
ordnance in many training and testing events. Non-explosive ordnance
munitions look and perform similarly to high explosive ordnance, but
lack the main explosive charge.
Defense Countermeasures--Naval forces depend on effective defensive
countermeasures to protect themselves against missile and torpedo
attack. Defensive countermeasures are devices designed to confuse,
distract, and confound precision guided munitions. Defensive
countermeasures analyzed in this LOA application include acoustic
countermeasures, which are used by surface ships and submarines to
defend against torpedo attack. Acoustic countermeasures are either
released from ships and submarines, or towed at a distance behind the
ship.
Mine Warfare Systems--The Navy divides mine warfare systems into
two categories: mine detection and mine neutralization. Mine detection
systems are used to locate, classify, and map suspected mines, on the
surface, in the water column, or on the sea floor. The Navy analyzed
the following mine detection systems for potential impacts to marine
mammals:
Towed or hull-mounted mine detection systems. These
detection systems use acoustic and laser or video sensors to locate and
classify suspect mines. Fixed and rotary wing platforms, ships, and
unmanned vehicles are used
[[Page 6982]]
for towed systems, which can rapidly assess large areas.
Unmanned/remotely operated vehicles. These vehicles use
acoustic and video or lasers to locate and classify mines and provide
unique capabilities in nearshore littoral areas, surf zones, ports, and
channels.
Marine mammal systems. The Navy deploys trained Atlantic
bottlenose dolphins (Tursiops truncatus) and California sea lions
(Zalopus californianus) for integrated training involving two primary
mission areas: to find objects such as inert mine shapes, and to detect
swimmers or other intruders around Navy facilities such as piers. These
systems also include one or more motorized small boats and several crew
members for each trained marine mammal. When not engaged in training,
Navy marine mammals are housed in temporary enclosures either on land
or aboard ships.
Mine Neutralization Systems--Mine neutralization systems disrupt,
disable, or detonate mines to clear ports and shipping lanes, as well
as littoral, surf, and beach areas in support of naval amphibious
operations. The Navy analyzed the following mine neutralization systems
for potential impacts to marine mammals:
Towed influence mine sweep systems. These systems use
towed equipment that mimic a particular ship's magnetic and acoustic
signature triggering the mine and causing it to explode.
Unmanned/remotely operated mine neutralization systems.
Surface ships and helicopters operate these systems, which place
explosive charges near or directly against mines to destroy the mine.
Airborne projectile-based mine clearance systems. These
systems neutralize mines by firing a small or medium-caliber non-
explosive, supercavitating projectile from a hovering helicopter.
Diver emplaced explosive charges. Operating from small
craft, divers put explosive charges near or on mines to destroy the
mine or disrupt its ability to function.
Classification of Non-Impulsive and Impulsive Sources Analyzed
In order to better organize and facilitate the analysis of about
300 sources of underwater non-impulsive sound or impulsive energy, the
Navy developed a series of source classifications, or source bins. This
method of analysis provides the following benefits:
Allows for new sources to be covered under existing
authorizations, as long as those sources fall within the parameters of
a ``bin;''
Simplifies the data collection and reporting requirements
anticipated under the MMPA;
Ensures a conservative approach to all impact analysis
because all sources in a single bin are modeled as the loudest source
(e.g., lowest frequency, highest source level, longest duty cycle, or
largest net explosive weight within that bin);
Allows analysis to be conducted more efficiently, without
compromising the results;
Provides a framework to support the reallocation of source
usage (hours/explosives) between different source bins, as long as the
total number and severity of marine mammal takes remain within the
overall analyzed and authorized limits. This flexibility is required to
support evolving Navy training and testing requirements, which are
linked to real world events.
A description of each source classification is provided in Tables
1-3. Non-impulsive sources are grouped into bins based on the
frequency, source level when warranted, and how the source would be
used. Impulsive bins are based on the net explosive weight of the
munitions or explosive devices. The following factors further describe
how non-impulsive sources are divided:
Frequency of the non-impulsive source:
[cir] Low-frequency sources operate below 1 kilohertz (kHz)
[cir] Mid-frequency sources operate at or above 1 kHz, up to and
including 10 kHz
[cir] High-frequency sources operate above 10 kHz, up to and
including 100 kHz
[cir] Very high-frequency sources operate above 100, but below 200
kHz
Source level of the non-impulsive source:
[cir] Greater than 160 decibels (dB), but less than 180 dB
[cir] Equal to 180 dB and up to 200 dB
[cir] Greater than 200 dB
How a sensor is used determines how the sensor's acoustic emissions
are analyzed. Factors to consider include pulse length (time source is
on); beam pattern (whether sound is emitted as a narrow, focused beam,
or, as with most explosives, in all directions); and duty cycle (how
often a transmission occurs in a given time period during an event).
There are also non-impulsive sources with characteristics that are
not anticipated to result in takes of marine mammals. These sources
have low source levels, narrow beam widths, downward directed
transmission, short pulse lengths, frequencies beyond known hearing
ranges of marine mammals, or some combination of these factors. These
sources were not modeled by the Navy, but are qualitatively analyzed in
Table 1-4 of the LOA application and the HSTT DEIS/OEIS.
Table 1--Impulsive Training and Testing Source Classes Analyzed
----------------------------------------------------------------------------------------------------------------
Source class Representative munitions Net explosive weight (lbs)
----------------------------------------------------------------------------------------------------------------
E1................................... Medium-caliber projectiles... 0.1-0.25 (45.4-113.4 g)
E2................................... Medium-caliber projectiles... 0.26-0.5 (117.9-226.8 g)
E3................................... Large-caliber projectiles.... >0.5-2.5 (>226.8 g-1.1 kg)
E4................................... Improved Extended Echo >2.5-5.0 (1.1-2.3 kg)
Ranging Sonobuoy.
E5................................... 5 in. (12.7 cm) projectiles.. >5-10 (>2.3-4.5 kg)
E6................................... 15 lb. (6.8 kg) shaped charge >10-20 (>4.5-9.1 kg)
E7................................... 40 lb. (18.1 kg) demo block/ >20-60 (>9.1-27.2 kg)
shaped charge.
E8................................... 250 lb. (113.4 kg) bomb...... >60-100 (>27.2-45.4 kg)
E9................................... 500 lb. (226.8 kg) bomb...... >100-250 (>45.4-113.4 kg)
E10.................................. 1,000 lb. (453.6 kg) bomb.... >250-500 (>113.4-226.8 kg)
E11.................................. 650 lb. (294.8 kg) mine...... >500-650 (>226.8-294.8 kg)
E12.................................. 2,000 lb. (907.2 kg) bomb.... >650-1,000 (>294.8-453.6 kg)
E13.................................. 1,200 lb. (544.3 kg) HBX >1,000-1,740 (>453.6-789.3 kg)
charge.
----------------------------------------------------------------------------------------------------------------
[[Page 6983]]
Table 2--Non-Impulsive Training Source Classes Analyzed
------------------------------------------------------------------------
Source
Source class category class Description
------------------------------------------------------------------------
Mid-Frequency (MF): Tactical MF1 Active hull-mounted surface
and non-tactical sources that ship sonar (e.g., AN/SQS-
produce mid-frequency (1 to 10 53C and AN/SQS-60).
kHz) signals.
MF1K Kingfisher object avoidance
mode associated with MF1
sonar.
MF2 Active hull-mounted surface
ship sonar (e.g., AN/SQS-
56).
MF2K Kingfisher mode associated
with MF2 sonar.
MF3 Active hull-mounted
submarine sonar (e.g., AN/
BQQ-10).
MF4 Active helicopter-deployed
dipping sonar (e.g., AN/AQS-
22 and AN/AQS-13).
MF5 Active acoustic sonobuoys
(e.g., AN/SSQ-62 DICASS).
MF6 Active underwater sound
signal devices (e.g., MK-
84).
MF11 Hull-mounted surface ship
sonar with an active duty
cycle greater than 80%.
MF12 High duty cycle--variable
depth sonar.
High-Frequency (HF) and Very HF1 Active hull-mounted
High-Frequency (VHF): Tactical HF4 submarine sonar (e.g., AN/
and non-tactical sources that BQQ-15).
produce high-frequency Active mine detection,
(greater than 10 kHz but less classification, and
than 200 kHz) signals. neutralization sonar (e.g.,
AN/SQS-20).
Anti-Submarine Warfare (ASW): ASW1 MF active Deep Water Active
Tactical sources such as ASW2 Distributed System (DWADS).
active sonobuoys and acoustic MF active Multistatic Active
countermeasures systems used Coherent (MAC) sonobuoy
during ASW training activities. (e.g., AN/SSQ-125).
ASW3 MF active towed active
acoustic countermeasure
systems (e.g., AN/SLQ-25
NIXIE).
ASW4 MF active expendable active
acoustic device
countermeasures (e.g., MK-
3).
Torpedoes (TORP): Source TORP1 HF active lightweight
classes associated with active torpedo sonar (e.g., MK-46,
acoustic signals produced by MK-54, or Anti-Torpedo
torpedoes. Torpedo).
TORP2 HF active heavyweight
torpedo sonar (e.g., MK-
48).
------------------------------------------------------------------------
Table 3--Non-Impulsive Testing Source Classes Analyzed
------------------------------------------------------------------------
Source
Source class category class Description
------------------------------------------------------------------------
Low-Frequency (LF): Sources LF4 Low-frequency sources equal
that produce low-frequency to 180 dB and up to 200 dB.
(less than 1 kilohertz [kHz])
signals.
LF5 Low-frequency sources less
than 180 dB.
LF6 Low-frequency sonar
currently in development
(e.g., anti-submarine
warfare sonar associated
with the Littoral Combat
Ship).
Mid-Frequency (MF): Tactical MF1 Hull-mounted surface ship
and non-tactical sources that MF1K sonar (e.g., AN/SQS-53C and
produce mid-frequency (1 to 10 AN/SQS-60).
kHz) signals. Kingfisher mode associated
with MF1 sonar (Sound
Navigation and Ranging).
MF2 Hull-mounted surface ship
sonar (e.g., AN/SQS-56).
MF3 Hull-mounted submarine sonar
(e.g., AN/BQQ-10).
MF4 Helicopter-deployed dipping
sonar (e.g., AN/AQS-22 and
AN/AQS-13).
MF5 Active acoustic sonobuoys
(e.g., DICASS).
MF6 Active underwater sound
signal devices (e.g., MK-
84).
MF8 Active sources (greater than
200 dB).
MF9 Active sources (equal to 180
dB and up to 200 dB).
MF10 Active sources (greater than
160 dB, but less than 180
dB) not otherwise binned.
MF12 High duty cycle--variable
depth sonar.
High-Frequency (HF) and Very HF1 Hull-mounted submarine sonar
High-Frequency (VHF): Tactical HF3 (e.g., AN/BQQ-10).
and non-tactical sources that HF4 Hull-mounted submarine sonar
produce high-frequency (classified).
(greater than 10 kHz but less Mine detection,
than 200 kHz) signals. classification, and
neutralization sonar (e.g.,
AN/SQS-20).
HF5 Active sources (greater than
200 dB).
HF6 Active sources (equal to 180
dB and up to 200 dB).
Anti-Submarine Warfare (ASW): ASW1 Mid-frequency Deep Water
Tactical sources such as Active Distributed System
active sonobuoys and acoustic (DWADS).
countermeasures systems used
during the conduct of anti-
submarine warfare testing
activities.
ASW2 Mid-frequency Multistatic
ASW2H Active Coherent sonobuoy
(e.g., AN/SSQ-125).
Mid-frequency sonobuoy
(e.g., high duty cycle)--
Sources that are analyzed
by hours.
ASW3 Mid-frequency towed active
acoustic countermeasure
systems (e.g., AN/SLQ-25).
ASW4 Mid-frequency expendable
active acoustic device
countermeasures (e.g., MK-
3).
[[Page 6984]]
Torpedoes (TORP): Source TORP1 Lightweight torpedo (e.g.,
classes associated with the MK-46, MK-54, or Surface
active acoustic signals Ship Defense System).
produced by torpedoes.
TORP2 Heavyweight torpedo (e.g.,
MK-48).
Acoustic Modems (M): Systems M3 Mid-frequency acoustic
used to transmit data modems (greater than 190
acoustically through water. dB).
Swimmer Detection Sonar (SD): SD1-SD2 High-frequency sources with
Systems used to detect divers short pulse lengths, used
and submerged swimmers. for the detection of
swimmers and other objects
for the purpose of port
security.
Airguns (AG): Underwater AG Up to 60 cubic inch airguns
airguns are used during (e.g., Sercel Mini-G).
swimmer defense and diver
deterrent training and testing
activities.
Synthetic Aperture Sonar (SAS): SAS1 MF SAS systems.
Sonar in which active acoustic SAS2 HF SAS systems.
signals are post-processed to SAS3 VHF SAS systems.
form high-resolution images of
the seafloor.
------------------------------------------------------------------------
Proposed Action
The Navy proposes to continue conducting training and testing
activities within the HSTT Study Area. The Navy has been conducting
military readiness training and testing activities in the HSTT Study
Area since the 1940s. Recently, these activities were analyzed in three
separate EISs completed between 2008 and 2011; the Hawaii Range Complex
(HRC) EIS/OEIS (U.S. Department of the Navy 2008a), the SOCAL Range
Complex EIS/OEIS (U.S. Department of the Navy 2008b), and the Silver
Strand Training Complex (SSTC) EIS (U.S. Department of the Navy 2011a).
These documents, among others, and their associated MMPA regulations
and authorizations, describe the baseline of training and testing
activities currently conducted in the Study Area.
The tempo and types of training and testing activities have
fluctuated due to changing requirements; the introduction of new
technologies; the dynamic nature of international events; advances in
warfighting doctrine and procedures; and changes in basing locations
for ships, aircraft, and personnel (force structure changes). Such
developments have influenced the frequency, duration, intensity, and
location of required training and testing.
Training
The Navy proposes to conduct training activities in the Study Area
as described in Tables 4 and 5. Detailed information about each
proposed activity (stressor, training event, description, sound source,
duration, and geographic location) can be found in Appendix A of the
HSTT DEIS/OEIS. NMFS used the detailed information in Appendix A of the
HSTT DEIS/OEIS to analyze the potential impacts to marine mammals.
Table 4 describes the annual number of impulsive source detonations
during testing activities within the HSTT Study Area, and Table 5
describes the annual number of hours or items of non-impulsive sources
used during training within the HSTT Study Area. The Navy's proposed
action is an adjustment to existing baseline training activities to
accommodate the following:
Force structure changes including the relocation of ships,
aircraft, and personnel;
Planned new aircraft platforms, new vessel classes, and
new weapons systems;
Ongoing training activities that were not addressed in
previous documentation; and
New range capabilities, such as hydrophone modifications,
upgrades, and replacement at instrumented Navy underwater tracking
ranges.
Table 4--Proposed Annual Number of Impulsive Source Detonations During
Training in the HSTT Study Area
------------------------------------------------------------------------
Annual in-
Net explosive weight water
Explosive class (NEW) detonations
(training)
------------------------------------------------------------------------
E1............................. (0.1 lb.-0.25 lb.)..... 19,840
E2............................. (0.26 lb.-0.5 lb.)..... 1,044
E3............................. (0.6 lb.-2.5 lb.)...... 3,020
E4............................. (>2.5 lb.-5 lb.)....... 668
E5............................. (>5 lb.-10 lb.)........ 8,154
E6............................. (>10 lb.-20 lb.)....... 538
E7............................. (>20 lb.-60 lb.)....... 407
E8............................. (>60 lb.-100 lb.)...... 64
E9............................. (>100 lb.-250 lb.)..... 16
E10............................ (>250 lb.-500 lb.)..... 19
E11............................ (>500 lb.-650 lb.)..... 8
E12............................ (>650 lb.-1000 lb.).... 224
E13............................ (>1000 lb.-1,740 lb.).. 9
------------------------------------------------------------------------
[[Page 6985]]
Table 5--Annual Hours and Items of Non-Impulsive Sources Used During
Training Within the HSTT Study Area
------------------------------------------------------------------------
Source
Source class category class Annual use
------------------------------------------------------------------------
Mid-Frequency (MF) Active sources MF1 11,588 hours.
from 1 to 10 kHz.
MF1K 88 hours.
MF2 3,060 hours.
MF2K 34 hours.
MF3 2,336 hours.
MF4 888 hours.
MF5 13,718 items.
MF11 1,120 hours.
MF12 1,094 hours.
High-Frequency (HF) and Very High- HF1 1,754 hours.
Frequency (VHF) tactical and non-
tactical sources that produce
signals greater than 10kHz but
less than 200 kHz.
HF4 4,848 hours.
Anti-Submarine Warfare (ASW)...... ASW1 224 hours.
Active ASW sources................ ASW2 1,800 items.
ASW3 16,561 hours.
ASW4 1,540 items.
Torpedoes (TORP).................. TORP1 170 items.
Active torpedo sonar.............. TORP2 400 items.
------------------------------------------------------------------------
Testing
The Navy's proposed testing activities are described in Tables 6
and 7. Detailed information about each proposed activity (stressor,
testing event, description, sound source, duration, and geographic
location) can be found in Appendix A of the HSTT DEIS/OEIS. NMFS used
the detailed information in Appendix A of the HSTT DEIS/OEIS to analyze
the potential impacts from testing activities on marine mammals. Table
6 describes the annual number of impulsive source detonations during
testing activities within the HSTT Study Area, and Table 7 describes
the annual number of hours or items of non-impulsive sources used
during testing within the HSTT Study Area.
Table 6--Proposed Annual Number of Impulsive Source Detonations During
Testing Activities Within the HSTT Study Area
------------------------------------------------------------------------
Annual in-
Net explosive weight water
Explosive class (NEW) detonations
(testing)
------------------------------------------------------------------------
E1............................. (0.1 lb.-0.25 lb.)..... 14,501
E2............................. (0.26 lb.-0.5 lb.)..... 0
E3............................. (0.6 lb.-2.5 lb.)...... 2,990
E4............................. (>2.5 lb.-5 lb.)....... 753
E5............................. (>5 lb.-10 lb.)........ 202
E6............................. (>10 lb.-20 lb.)....... 37
E7............................. (>20 lb.-60 lb.)....... 21
E8............................. (>60 lb.-100 lb.)...... 12
E9............................. (>100 lb.-250 lb.)..... 0
E10............................ (>250 lb.-500 lb.)..... 31
E11............................ (>500 lb.-650 lb.)..... 14
E12............................ (>650 lb.-1000 lb.).... 0
E13............................ (>1000 lb.-1,740 lb.).. 0
------------------------------------------------------------------------
Table 7--Annual Hours and Items of Non-Impulsive Sources Used During
Testing Within the HSTT Study Area
------------------------------------------------------------------------
Source
Source class category class Annual use
------------------------------------------------------------------------
Low-Frequency (LF) Sources that LF4 52 hours.
produce signals less than 1 kHz.
LF5 2,160 hours.
LF6 192 hours.
Mid-Frequency (MF) Tactical and MF1 180 hours.
non-tactical sources that produce
signals from 1 to 10 kHz.
MF1K 18 hours.
MF2 84 hours.
MF3 392 hours.
MF4 693 hours.
MF5 5,024 items.
[[Page 6986]]
MF6 540 items.
MF8 2 hours.
MF9 3,039 hours.
MF10 35 hours.
MF12 336 hours.
High-Frequency (HF) and Very High- HF1 1,025 hours.
Frequency (VHF): Tactical and non-
tactical sources that produce
signals greater than 10kHz but
less than 200kHz.
HF3 273 hours.
HF4 1,336 hours.
HF5 1,094 hours.
HF6 3,460 hours.
Anti-Submarine Warfare (ASW) ASW1 224 hours.
Tactical sources used during anti-
submarine warfare training and
testing activities.
ASW2 2,260 items.
ASW2H 255 hours.
ASW3 1,278 hours.
ASW4 477 items.
Torpedoes (TORP) Source classes TORP1 701 items.
associated with active acoustic
signals produced by torpedoes.
TORP2 732 items.
Acoustic Modems (M) Transmit data M3 4,995 hours.
acoustically through the water.
Swimmer Detection Sonar (SD) Used SD1 38 hours.
to detect divers and submerged
swimmers.
Airguns (AG) Used during swimmer AG 5 uses.
defense and diver deterrent
training and testing activities.
Synthetic Aperture Sonar (SAS): SAS1 2,700 hours.
Sonar in which active acoustic
signals are post-processed to
form high-resolution images of
the seafloor.
SAS2 4,956 hours.
SAS3 3,360 hours.
------------------------------------------------------------------------
Vessels
Vessels used as part of the proposed action include ships,
submarines, boats, and Unmanned Undersea Vehicles (UUVs) ranging in
size from small, 5-m Rigid Hull Inflatable Boats to 333-m long aircraft
carriers. Representative Navy vessel types, lengths, and speeds used in
both training and testing activities are shown in Table 8. While these
speeds are representative, some vessels operate outside of these speeds
due to unique training or safety requirements for a given event.
Examples include increased speeds needed for flight operations, full
speed runs to test engineering equipment, time critical positioning
needs, etc. Examples of decreased speeds include speeds less than 5
knots or completely stopped for launching small boats, certain tactical
maneuvers, target launch or retrievals, UUVs etc.
The number of Navy vessels in the HSTT Study Area varies based on
training and testing schedules. Most activities include either one or
two vessels, with an average of one vessel per activity, and last from
a few hours up to two weeks. Multiple ships, however, can be involved
with major training events. Vessel movement and the use of in-water
devices as part of the proposed action would be concentrated in
portions of the Study Area within SOCAL, naval installations at San
Diego and Pearl Harbor, and on instrumented underwater ranges. Surface
and sub-surface vessel operations in the Study Area may result in
marine mammal strikes.
Table 8--Typical Navy Boat and Vessel Types With Length Greater Than 18
Meters Used Within the HSTT Study Area
------------------------------------------------------------------------
Example(s)
(specifications in
meters (m) for length, Typical
Vessel type (>18 m) metric tons (mt) for operating speed
mass, and knots for (knots)
speed)
------------------------------------------------------------------------
Aircraft Carrier.............. Aircraft Carrier (CVN) 10 to 15.
length: 333 m beam:
41 m draft: 12 m
displacement: 81,284
mt max. speed: 30+
knots.
Surface Combatants............ Cruiser (CG) length: 10 to 15.
173 m beam: 17 m
draft: 10 m
displacement: 9,754
mt max. speed: 30+
knots.
Destroyer (DDG)
length: 155 m beam:
18 m draft: 9 m
displacement: 9,648
mt max. speed: 30+
knots.
Frigate (FFG) length:
136 m beam: 14 m
draft: 7 m
displacement: 4,166
mt max. speed: 30+
knots.
Littoral Combat Ship
(LCS) length: 115 m
beam: 18 m draft: 4 m
displacement: 3,000
mt max. speed: 40+
knots.
[[Page 6987]]
Amphibious Warfare Ships...... Amphibious Assault 10 to 15.
Ship (LHA, LHD)
length: 253 m beam:
32 m draft: 8 m
displacement: 42,442
mt max. speed: 20+
knots.
Amphibious Transport
Dock (LPD) length:
208 m beam: 32 m
draft: 7 m
displacement: 25,997
mt max. speed: 20+
knots.
Dock Landing Ship
(LSD) length: 186 m
beam: 26 m draft: 6 m
displacement: 16,976
mt max. speed: 20+
knots.
Mine Warship Ship............. Mine Countermeasures 5 to 8.
Ship (MCM) length: 68
m beam: 12 m draft: 4
m displacement: 1,333
max. speed: 14 knots.
Submarines.................... Attack Submarine (SSN) 8 to 13.
length: 115 m beam:
12 m draft: 9 m
displacement: 12,353
mt max. speed: 20+
knots.
Guided Missile
Submarine (SSGN)
length: 171 m beam:
13 m draft: 12 m
displacement: 19,000
mt max. speed: 20+
knots.
Combat Logistics Force Ships*. Fast Combat Support 8 to 12.
Ship (T-AOE) length:
230 m beam: 33 m
draft: 12 m
displacement: 49,583
max. speed: 25 knots.
Dry Cargo/Ammunition
Ship (T-AKE) length:
210 m beam: 32 m
draft: 9 m
displacement: 41,658
mt max speed: 20
knots.
Fleet Replenishment
Oilers (T-AO) length:
206 m beam: 30 m
draft: 11
displacement: 42,674
mt max. speed: 20
knots.
Fleet Ocean Tugs (T-
ATF) length: 69 m
beam: 13 m draft: 5 m
displacement: 2,297
max. speed: 14 knots.
Support Craft/Other........... Landing Craft, Utility 3 to 5.
(LCU) length: 41m
beam: 9 m draft: 2 m
displacement: 381 mt
max. speed: 11 knots.
Landing Craft,
Mechanized (LCM)
length: 23 m beam: 6
m draft: 1 m
displacement: 107 mt
max. speed: 11 knots.
Support Craft/Other MK V Special Variable.
Specialized High Speed. Operations Craft
length: 25 m beam: 5
m displacement: 52 mt
max. speed: 50 knots.
------------------------------------------------------------------------
* CLF vessels are not homeported in Pearl Harbor or San Diego, but are
frequently used for various fleet support and training support events
in the HSTT Study Area.
Duration and Location
Training and testing activities would be conducted in the HSTT
Study Area from January 2014 through January 2019. The HSTT Study Area
is comprised of established operating and warning areas across the
north-central Pacific Ocean, from Southern California to Hawaii and the
International Date Line. The defined Study Area has expanded beyond the
areas included in previous Navy authorizations to include transit
routes and pierside locations. This expansion is not an increase in the
Navy's training and testing area, but rather an increase in the area to
be analyzed (i.e., not previously analyzed) under an incidental take
authorization in support of the HSTT EIS/OEIS. The Study Area includes
three existing range complexes: the Hawaii Range Complex (HRC), the
Southern California (SOCAL) Range Complex, and the Silver Strand
Training Complex (SSTC). Each range complex is an organized and
designated set of specifically bounded geographic areas, which includes
a water component (above and below the surface), airspace, and
sometimes a land component. Operating areas (OPAREAs) and special use
airspace are established within each range complex. These designations
are further described in Chapter 2 of the Navy's LOA application. In
addition to Navy range complexes, the Study Area includes Navy pierside
locations where sonar maintenance and testing activities occur (San
Diego Bay, Pearl Harbor) and transit corridors on the high seas where
training and sonar testing may occur during vessel transit.
Hawaii Range Complex (HRC)--The HRC geographically encompasses
ocean areas located around the Hawaiian Islands chain. The largest
component of the HRC is the temporary operating area, which extends
north and west from the island of Kauai and totals over 2 million
square nautical miles (nm\2\) of air and sea space. This area is used
for Navy ship transit throughout the year and for missile defense
testing activities as required to support missile defense testing
activities. Nearly all of the training and testing activities within
the HRC take place within the smaller Hawaii OPAREA, which consists of
235,000 nm\2\ of special use airspace, and sea and undersea space. The
Hawaii OPAREA is the portion of the range complex immediately
surrounding the island chain of Hawaii. Military activities and
exercises were excluded from the list of prohibitions triggered when
the Monument was established in 2006, so long as the activities are
``carried out in a manner that avoids, to the extent practicable and
consistent with operational requirements, adverse impacts on monument
resources and qualities.'' More detailed information on the HRC,
including maps, is provided in Chapter 2 of the Navy's LOA application
(http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications).
Southern California (SOCAL) Range Complex--The SOCAL Range Complex
is situated between Dana Point and San Diego, and extends more than 600
nm southwest into the Pacific Ocean. The two primary components of the
SOCAL Range Complex are the ocean operating areas and the special use
airspace. The SOCAL Range Complex includes San Diego Bay and a small
portion of the Point Mugu Sea Range. The Silver Strand Training Complex
is also included as part of the Southern California portion for this
application. More detailed information on the SOCAL Range Complex,
including maps, is provided in Chapter 2 of the Navy's LOA application
(http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications).
Transit Corridor--In addition to the three range complexes, a
transit corridor outside the bounds of existing range
[[Page 6988]]
complexes is included in the Navy's request. This transit corridor is
important to the Navy in that it provides adequate air, sea, and
undersea space in which ships and aircraft can conduct training and
some sonar maintenance and testing while en route between Southern
California and Hawaii. The transit corridor is an area encompassing the
shortest distance from San Diego to the center of the HRC. While in
transit, ships and aircraft would, at times, conduct basic and routine
unit level training as long as the training does not interfere with the
primary objective of reaching their intended destination. Ships would
also conduct sonar maintenance, which includes active sonar
transmissions. The portion of the transit corridor to the east of
140[deg] west longitude is included in the analysis of SOCAL activities
and the area to the west of that meridian is included in the analysis
of HRC activities since these portions of the corridor correspond with
the marine mammal stocks in those range complexes.
Pierside Locations--The Study Area also includes select pierside
locations where Navy surface ship and submarine sonar maintenance
testing occur. These pierside locations include channels and transit
routes in ports, and facilities associated with ports and shipyards at
Navy piers in San Diego, California, and Navy piers, shipyards, and the
Intermediate Maintenance Facility in Pearl Harbor, Hawaii.
Description of Marine Mammals in the Area of the Specified Activities
Thirty-nine marine mammal species are known to occur in the Study
Area, including seven mysticetes (baleen whales), 25 odontocetes
(dolphins and toothed whales), six pinnipeds (seals and sea lions), and
the Southern sea otter. Among these species, there are 72 stocks
managed by NMFS or the U.S. Fish and Wildlife Service (USFWS) in the
U.S. Exclusive Economic Zone (EEZ). These species and their numbers are
presented in Table 9 and relevant information on their status,
distribution, and seasonal distribution (when applicable) is presented
in Chapter 4 of the Navy's LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications). Consistent with NMFS most
recent Pacific Stock Assessment Report, a single species may include
multiple stocks recognized for management purposes (e.g., spinner
dolphin), while other species are grouped into a single stock due to
limited species-specific information (e.g., beaked whales belonging to
the genus Mesoplodon).
Species that may have once inhabited and transited the Study Area,
but have not been sighted in recent years, include the North Pacific
right whale (Eubalaena japonica), harbor porpoise (Phocoena phocoena),
and Steller sea lion (Eumetopias jubatus). These species are not
expected to be exposed to or affected by any project activities and,
therefore, are not discussed further.
Table 9--Marine Mammals With Possible or Confirmed Presence Within the HSTT Study Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
Stock Study area Occurrence in
Common name Scientific name Study area Stock abundance CV abundance (CV) study area ESA/MMPA Status
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Cetacea
Suborder Mysticeti (Baleen Whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenopteridae (Rorquals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale................ Megaptera SOCAL California, 2,043 36 Seasonal; More Endangered/
novaeangliae. Oregon, & -0.1 -0.51 sightings Depleted.
Washington. around the
northern
Channel Islands.
HRC Central North 10,103 4,491 Seasonal; Endangered/
Pacific. (N/A) (N/A) Throughout Depleted.
known breeding
grounds during
winter and
spring (most
common November
through April).
Blue whale.................... Balaenoptera SOCAL Eastern North 2,497 842 Seasonal; arrive Endangered/
musculus. Pacific. -0.24 -0.2 April-May; more Depleted.
common late
summer to fall.
HRC Central North No data. No data. Seasonal; Endangered/
Pacific. infrequent Depleted.
winter migrant;
few sightings.
Fin whale..................... Balaenoptera SOCAL California, 3,044 359 Year-round Endangered/
physalus. Oregon, & -0.18 -0.4 presence. Depleted.
Washington.
HRC Hawaiian......... 174 174 Seasonal; mainly Endangered/
-0.72 -0.72 fall and winter Depleted.
although
considered rare
in HRC.
Sei whale..................... Balaenoptera SOCAL Eastern North 126 7 Rare; Endangered/
borealis. Pacific. -0.53 -1.07 infrequently Depleted.
sighted in
California.
Only nine
confirmed
sightings on WA/
OR/CA surveys
from 1991-2008.
[[Page 6989]]
HRC Hawaiian......... 77 77 Rare; limited Endangered/
-1.06 -1.06 sightings of Depleted.
seasonal
migrants that
feed at higher
latitudes.
Bryde's whale................. Balaenoptera SOCAL Eastern Tropical 13,000 7 Limited summer ................
edeni. Pacific. -0.2 -1.07 occurrence.
HRC Hawaiian......... 469 469 Uncommon; ................
-0.45 -0.45 distributed
throughout the
Hawaii
Exclusive
Economic Zone.
Minke whale................... Balaenoptera SOCAL California, 478 226 Less common in ................
acutorostrata. Oregon, & -1.36 -1.02 summer; small
Washington. numbers around
northern
Channel Islands.
HRC Hawaiian......... No data. No data. Regular but ................
seasonal
occurrence
(November-March
).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Eschrichtildae (Gray Whale)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray whale.................... Eschrichtius SOCAL Eastern North 18,813 Population Transient during ................
robustus. Pacific. -0.07 migrates through seasonal
SOCAL migrations.
----------------------------------------------------------------------------------------
HRC No known occurrence
--------------------------------------------------------------------------------------------------------------------------------------------------------
Suborder Odontoceti (Toothed Whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Physeteridae (Sperm Whale)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale................... Physeter SOCAL California, 971 607 Common year Endangered/
macrocephalus. Oregon, & -0.31 -0.57 round; more Depleted.
Washington. likely in
waters > 1,000
m, most often >
2,000 m.
HRC Hawaiian......... 6,919 6,919 Widely Endangered/
-0.81 -0.81 distributed Depleted.
year round;
more likely in
waters > 1,000
m, most often >
2,000 m.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Kogiidae (Pygmy and Dwarf Sperm Whale)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pygmy sperm whale............. Kogia breviceps.. SOCAL California, 579 ................. Seaward of 500- ................
Oregon, & -1.02 1000 m; limited
Washington. sightings over
entire Southern
Cal. Bight.
HRC Hawaiian 7,138............ 7,138 Stranding numbers
-1.12............ -1.12 suggest this
species is more
common than
infrequent
sightings during
survey (Barlow
2006) indicated.
Dwarf sperm whale............. Kogia sima....... SOCAL California, Unknown ................. Seaward of 500- ................
Oregon, & 1000 m; no
Washington. confirmed
sightings over
entire Southern
Cal. Bight (all
Kogia spp. or
Kogia
breviceps).
[[Page 6990]]
HRC Hawaiian......... 17,519 17,519 Stranding ................
-0.74 -0.74 numbers suggest
this species is
more common
than infrequent
sightings
during survey
(Barlow 2006)
indicated.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae (Dolphins)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Killer whale.................. Orcinus orca..... SOCAL Eastern North 240 30 Uncommon; occurs ................
Pacific Offshore. -0.49 -0.73 infrequently;
more likely in
winter.
SOCAL Eastern North 451 ................. Uncommon; occurs ................
Pacific -0.49 infrequently;
Transient. more likely in
winter.
HRC Hawaiian......... 349 349 Uncommon; ................
-0.98 -0.98 infrequent
sightings.
False killer whale............ Pseudorca SOCAL Eastern Tropical Unknown ................. Uncommon; warm ................
crassidens. Pacific. water species;
although
stranding
records from
the Channel
Islands.
HRC Hawaii Insular 151 151 Regular......... Endangered.
[7],[8]. -0.2 -0.2
HRC Hawaii Pelagic 1,503 1,503 Regular......... ................
\7\. -0.66 -0.66
HRC Northwest 522 522 Regular......... ................
Hawaiian Islands -1.09 -1.09
\7\.
Pygmy killer whale............ Feresa attenuata. SOCAL Tropical......... Unknown Extralimital. Extralimital ................
within the
south-west
boundary of the
SOCAL Range
Complex.
HRC Hawaiian......... 956 956 Year-round ................
-0.83 -0.83 resident;
abundance based
on 3 sightings
(Barlow 2006)..
Short-finned pilot whale...... Globicephala SOCAL California, 760 118 Uncommon; more ................
macrorhynchus. Oregon, & -0.64 -1.04 common before
Washington. 1982.
HRC Hawaiian......... 8,870 8,870 Commonly ................
-0.38 -0.38 observed around
main Hawaiian
Islands and
Northwestern
Hawaiian
Islands.
----------------------------------------------------------------------------------------
Melon-headed whale............ Peponocephala SOCAL No known occurrence
electra.
----------------------------------------------------------------------------------------
HRC Hawaiian......... 2,950 2,950 Regular.........
-1.17 -1.17
Long-beaked common dolphin.... Delphinus SOCAL California....... 27,046 17,530 Common; more ................
capensis. -0.59 -0.57 inshore
distribution
(within 50 nm
of coast).
----------------------------------------------------------------------------------------
HRC No known occurrence
----------------------------------------------------------------------------------------
Short-beaked common dolphin... Delphinus delphis SOCAL California, 411,211 165,400 Common; one of ................
Oregon, & -0.21 -0.19 the most
Washington. abundant SOCAL
dolphins;
higher summer
densities.
--------------------------------------------------------------------------------------------------------------------------------------------------------
HRC No known occurrence
----------------------------------------------------------------------------------------
[[Page 6991]]
Bottlenose dolphin............ Tursiops SOCAL California 323 323 Limited, small ................
truncatus. Coastal. -0.13 -0.13 population
within 1 km of
shore.
SOCAL California, 1,006 1,831 Common.......... ................
Oregon, & -0.48 -0.47
Washington
Offshore.
HRC Hawaii Pelagic... 3,178 3,178 Common in deep ................
-0.59 -0.59 offshore waters.
HRC Kauai and Niihau. 147 147 Common in ................
-0.11 -0.11 shallow
nearshore
waters (1000 m
or less).
HRC Oahu............. 594 594 Common in ................
-0.54 -0.54 shallow
nearshore
waters (1000 m
or less).
HRC 4-Islands Region. 153 153 Common in ................
-0.24 -0.24 shallow
nearshore
waters (1000 m
or less).
HRC Hawaii Island.... 102 102 Common in ................
-0.13 -0.13 shallow
nearshore
waters (1000 m
or less).
Pantropical spotted dolphin... Stenella SOCAL Eastern Tropical Unknown. ................. Rare; associated ................
attenuata. Pacific. with warm
tropical
surface waters.
HRC Hawaiian......... 8,978 8,978 Common; primary ................
-0.48 -0.48 occurrence
between 100 and
4,000 meters
depth.
Striped dolphin............... Stenella SOCAL California, 10,908 8,697 Occasional ................
coerulealba. Oregon, & -0.34 -0.34 visitor; warm
Washington. water oceanic
species.
HRC Hawaiian......... 13,143 13,143 Occurs regularly ................
-0.46 -0.46 year round but
infrequent
sighting data.
----------------------------------------------------------------------------------------
Spinner dolphin............... Stenella SOCAL No known occurrence
longirostris.
----------------------------------------------------------------------------------------
HRC Hawaii Pelagic... Unknown. 3,351 Common year ................
-0.74 for entire round in
Hawaiian Islands offshore waters.
Stock Complex
HRC Hawaii Island.... Unknown. 3,351 Common year ................
-0.74 for entire round; rest in
Hawaiian Islands nearshore
Stock Complex waters during
the day and
move offshore
to feed at
night.
HRC Oahu/4-Islands... Unknown. 3,351 Common year ................
-0.74 for entire round; rest in
Hawaiian Islands nearshore
Stock Complex waters during
the day and
move offshore
to feed at
night.
HRC Kauai/Niihau..... Unknown. 3,351 Common year ................
-0.74 for entire round; rest in
Hawaiian Islands nearshore
Stock Complex waters during
the day and
move offshore
to feed at
night.
[[Page 6992]]
HRC Pearl and Hermes Unknown. 3,351 Common year ................
Reef. -0.74 for entire round; rest in
Hawaiian Islands nearshore
Stock Complex waters during
the day and
move offshore
to feed at
night.
HRC Kure/Midway...... Unknown. 3,351 Common year ................
-0.74 for entire round; rest in
Hawaiian Islands nearshore
Stock Complex waters during
the day and
move offshore
to feed at
night.
Rough-toothed dolphin......... Steno bredanensis SOCAL Tropical and warm Unknown. ................. Rare; more ................
temperate. tropical
offshore
species.
HRC Hawaiian......... 8,709 8,709 Common ................
-0.45 -0.45 throughout the
main Hawaiian
Islands and
Hawaii
Exclusive
Economic Zone.
Pacific white-sided dolphin... Lagenorhynchus SOCAL California, 26,930 2,196 Common; year- ................
obliquidens. Oregon, & -0.28 -0.71 round cool
Washington. water species;
more abundant
November-April.
--------------------------------------------------------------------------------------------------------------------------------------------------------
HRC No known occurrence
--------------------------------------------------------------------------------------------------------------------------------------------------------
Northern right whale dolphin.. Lissodelphis SOCAL California, 8,334 1,172 Common; cool ................
borealis. Oregon, & -0.4 -0.52 water species;
Washington. more abundant
November-April.
----------------------------------------------------------------------------------------
HRC No known occurrence
----------------------------------------------------------------------------------------
Fraser's dolphin.............. Lagenodelphis SOCAL No known occurrence
hosei.
----------------------------------------------------------------------------------------
HRC Hawaiian......... 10,226 10,226 Tropical species ................
-1.16 -1.16 only recently
documented
within Hawaii
Exclusive
Economic Zone
(2002 survey).
Risso's dolphins.............. Grampus griseus.. SOCAL California, 6,272 3,418 Common; present ................
Oregon, & -0.3 -0.31 in summer, but
Washington. higher
densities
November-April.
HRC Hawaiian......... 2,372 2,372 Have been ................
-0.97 -0.97 considered rare
but six
sightings in
Hawaii
Exclusive
Economic Zone
during 2002
survey.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocoenidae (Porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dall's porpoise............... Phocoenoidea SOCAL California, 42,000 727 Common in cold ................
dalli. Oregon, & -0.33 -0.99 water periods;
Washington. more abundant
November-April.
----------------------------------------------------------------------------------------
HRC No known occurrence
----------------------------------------------------------------------------------------
[[Page 6993]]
Family Ziphiidae (Beaked Whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Cuvier's beaked whale......... Ziphius SOCAL California, 2,143 911 Possible year- ................
cavirostris. Oregon, & -0.65 -0.68 round
Washington. occurrence but
difficult to
detect due to
diving behavior.
HRC Hawaiian......... 15,242 15,242 Year-round ................
-1.43 -1.43 occurrence but
difficult to
detect due to
diving behavior.
Baird's beaked whale.......... Berardius bairdii SOCAL California, 907 127 Primarily along ................
Oregon, & -0.49 -1.14 continental
Washington. slope from late
spring to early
fall.
----------------------------------------------------------------------------------------
HRC No known occurrence
----------------------------------------------------------------------------------------
Longman's beaked whale........ Indopacetus SOCAL No known occurrence
pacificus.
----------------------------------------------------------------------------------------
HRC Hawaiian......... 1,007 1,007 One of the ................
-1.26 -1.26 rarest and
least known
cetacean
species;
abundance based
on Barlow 2006
with 3
sightings,
however,
multiple
sightings
during 2010
HICEAS.
Blainville's beaked whale..... Mesoplodon SOCAL California, 603 132 Distributed ................
densirostris. Oregon, & -1.16 (0.96; for throughout deep
Washington. Mesoplodon waters and
spp.). continental
slope regions;
difficult to
detect given
diving behavior.
HRC Hawaiian......... 2,872 2,872 Year-round ................
-1.25 -1.25 occurrence but
difficult to
detect due to
diving behavior.
Mesoplodont beaked whales Mesoplodon spp... SOCAL California, 1,024 132 Distributed ................
(SOCAL estimates also include Oregon, & -0.77 -0.96 throughout deep
Blainville's beaked whale Washington. waters and
listed separately above). continental
slope regions;
difficult to
detect given
diving
behavior.
Limited
sightings;
generally
seaward of 500-
1000 m.
----------------------------------------------------------------------------------------
HRC No known occurrence of five Mesoplodon species (M. carlhubbsi, M. ginkgodens, M.
perrini, M. peruvianus, M. stejnegeri)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Suborder Pinnipedia [9, 10]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (Fur Seals and Sea Lions)
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion........... Zalophus SOCAL U.S. Stock....... 238,000 ................. Most common ................
californianus. pinniped,
Channel Islands
breeding sites
in summer.
----------------------------------------------------------------------------------------
HRC No known occurrence
----------------------------------------------------------------------------------------
[[Page 6994]]
Northern fur seal............. Callorhinus SOCAL San Miguel Island 9,968 Stock is outside Common; small ................
ursinus. of SOCAL. population
breeds on San
Miguel Island.
May-October.
----------------------------------------------------------------------------------------
HRC No known occurrence
----------------------------------------------------------------------------------------
Guadalupe fur seal............ Arctocephalus SOCAL Mexico........... 7,408 ................. Rare; Occasional Threatened/
townsendi. visitor to Depleted.
northern
Channel
Islands; mainly
breeds on
Guadalupe
Island, Mexico,
May-July.
----------------------------------------------------------------------------------------
HRC No known occurrence
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (True Seals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Hawaiian monk seal............ Monachus SOCAL No known occurrence
schauinslandi.
--------------------------------------------------------------------------------------------------------------------------------------------------------
HRC Hawaiian......... 1,161 1,161 Predominantly Endangered/
occur at Depleted.
Northwestern
Hawaiian
Islands;
approximately
150 in Main
Hawaiian
Islands.
Northern elephant seal........ Mirounga SOCAL California 124,000 SNI 9,794 pups in Common; Channel ................
angustirostris. Breeding. 2000. SCI up to Island haul-
16 through 2000 outs of
different age
classes;
including SCI
December-March
and April-
August; spend 8-
10 months at
sea.
HRC ............. ................. Extralimital....
Harbor seal................... Phoca vitulina... SOCAL California....... 34,233 5,271 Common; Channel ................
(All age classes Islands haul-
from aerial outs including
counts). SCI and La
Jolla; bulk of
stock found
north of Pt.
Conception.
----------------------------------------------------------------------------------------
HRC No known occurrence
--------------------------------------------------------------------------------------------------------------------------------------------------------
Information on the status, distribution, abundance, and
vocalizations of marine mammal species in the Study Area may be viewed
in Chapter 4 of their LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications). Further information on the
general biology and ecology of marine mammals is included in the HSTT
Draft EIS/OEIS. In addition, NMFS publishes annual stock assessment
reports for marine mammals, including stocks that occur within the
Study Area (http://www.nmfs.noaa.gov/pr/species/mammals).
Marine Mammal Hearing and Vocalizations
Cetaceans have an auditory anatomy that follows the basic mammalian
pattern, with some changes to adapt to the demands of hearing
underwater. The typical mammalian ear is divided into an outer ear,
middle ear, and inner ear. The outer ear is separated from the inner
ear by a tympanic membrane, or eardrum. In terrestrial mammals, the
outer ear, eardrum, and middle ear transmit airborne sound to the inner
ear, where the sound waves are propagated through the cochlear fluid.
Since the impedance of water is close to that of the tissues of a
cetacean, the outer ear is not required to transduce sound energy as it
does when sound waves travel from air to fluid (inner ear). Sound waves
traveling through the inner ear cause the basilar membrane to vibrate.
Specialized cells, called hair cells, respond to the vibration and
produce nerve pulses that are transmitted to the central nervous
system. Acoustic energy causes the basilar membrane in the cochlea to
vibrate. Sensory cells at different positions along the basilar
membrane are excited by different frequencies of sound (Pickles, 1998).
Marine mammal vocalizations often extend both above and below the
range of human hearing; vocalizations with frequencies lower than 20 Hz
are labeled as infrasonic and those higher than 20 kHz as ultrasonic
(National Research Council (NRC), 2003; Figure 4-1). Measured data on
the hearing abilities of cetaceans are sparse, particularly for the
larger cetaceans such as the baleen whales. The auditory thresholds of
some of the smaller
[[Page 6995]]
odontocetes have been determined in captivity. It is generally believed
that cetaceans should at least be sensitive to the frequencies of their
own vocalizations. Comparisons of the anatomy of cetacean inner ears
and models of the structural properties and the response to vibrations
of the ear's components in different species provide an indication of
likely sensitivity to various sound frequencies. The ears of small
toothed whales are optimized for receiving high-frequency sound, while
baleen whale inner ears are best in low to infrasonic frequencies
(Ketten, 1992; 1997; 1998).
Baleen whale vocalizations are composed primarily of frequencies
below 1 kHz, and some contain fundamental frequencies as low as 16 Hz
(Watkins et al., 1987; Richardson et al., 1995; Rivers, 1997; Moore et
al., 1998; Stafford et al., 1999; Wartzok and Ketten, 1999) but can be
as high as 24 kHz (humpback whale; Au et al., 2006). Clark and Ellison
(2004) suggested that baleen whales use low-frequency sounds not only
for long-range communication, but also as a simple form of echo
ranging, using echoes to navigate and orient relative to physical
features of the ocean. Information on auditory function in baleen
whales is extremely lacking. Sensitivity to low-frequency sound by
baleen whales has been inferred from observed vocalization frequencies,
observed reactions to playback of sounds, and anatomical analyses of
the auditory system. Although there is apparently much variation, the
source levels of most baleen whale vocalizations lie in the range of
150-190 dB re 1 [micro]Pa at 1 m. Low-frequency vocalizations made by
baleen whales and their corresponding auditory anatomy suggest that
they have good low-frequency hearing (Ketten, 2000), although specific
data on sensitivity, frequency or intensity discrimination, or
localization abilities are lacking. Marine mammals, like all mammals,
have typical U-shaped audiograms that begin with relatively low
sensitivity (high threshold) at some specified low frequency with
increased sensitivity (low threshold) to a species specific optimum
followed by a generally steep rise at higher frequencies (high
threshold) (Fay, 1988).
The toothed whales produce a wide variety of sounds, which include
species-specific broadband ``clicks'' with peak energy between 10 and
200 kHz, individually variable ``burst pulse'' click trains, and
constant frequency or frequency-modulated (FM) whistles ranging from 4
to 16 kHz (Wartzok and Ketten, 1999). The general consensus is that the
tonal vocalizations (whistles) produced by toothed whales play an
important role in maintaining contact between dispersed individuals,
while broadband clicks are used during echolocation (Wartzok and
Ketten, 1999). Burst pulses have also been strongly implicated in
communication, with some scientists suggesting that they play an
important role in agonistic encounters (McCowan and Reiss, 1995), while
others have proposed that they represent ``emotive'' signals in a
broader sense, possibly representing graded communication signals
(Herzing, 1996). Sperm whales, however, are known to produce only
clicks, which are used for both communication and echolocation
(Whitehead, 2003). Most of the energy of toothed whale social
vocalizations is concentrated near 10 kHz, with source levels for
whistles as high as 100 to 180 dB re 1 [micro]Pa at 1 m (Richardson et
al., 1995). No odontocete has been shown audiometrically to have acute
hearing (<80 dB re 1 [micro]Pa) below 500 Hz (DoN, 2001). Sperm whales
produce clicks, which may be used to echolocate (Mullins et al., 1988),
with a frequency range from less than 100 Hz to 30 kHz and source
levels up to 230 dB re 1 [micro]Pa 1 m or greater (Mohl et al., 2000).
Marine Mammal Density Estimates
A quantitative analysis of impacts on a species requires data on
the abundance and distribution of the species population in the
potentially impacted area. One metric for performing this type of
analysis is density, which is the number of animals present per unit
area. The Navy compiled existing, publically available density data for
use in the quantitative acoustic impact analysis. There is no single
source of density data for every area of the world, species, and season
because of the costs, resources, and effort required to provide
adequate survey coverage to sufficiently estimate density. Therefore,
to estimate marine mammal densities for large areas like the HSTT Study
Area, the Navy compiled data from several sources. The Navy developed a
hierarchy of density data sources to select the best available data
based on species, area, and time (season). The resulting Geographic
Information System database, called the Navy Marine Species Density
Database, includes seasonal density values for every marine mammal
species present within the HSTT Study Area (Navy, 2012).
The Navy Marine Species Density Database includes a compilation of
the best available density data from several primary sources and
published works including survey data from NMFS within the U.S.
Exclusive Economic Zone. The Navy ranked their modeling methods as
follows:
1. Density spatial model based estimates will be used when
available (e.g., NMFS' Southwest Fisheries Science Center models for
the California Current Ecosystem and the Central Pacific).
2. If no density spatial model based estimates are available, the
following can be used in order of preference:
a. Density estimates using designed-based methods incorporating
line-transect survey data and involving spatial stratification (i.e.,
estimates split by depth strata or arbitrary survey sub-regions).
b. Density estimates using designed-based methods incorporating
only line-transect survey data (i.e., regional density estimate, stock
assessment report).
c. Density estimates derived using a Relative Environmental
Suitability (RES) model in conjunction with survey data from Sea Mammal
Research Unit (SMRU) Ltd or in conjunction with a global population
estimate from Kaschner et al.'s (2006) density data.
In some cases, extrapolation from neighboring regional density
estimates or population/stock assessments is appropriate based on
expert opinion. This is often preferred over using RES models because
of discrepancies identified by local expert knowledge. This includes an
extrapolation of no occurrence based on other sources of data such as
the NMFS stock assessment reports or expert judgment. Additional
information on the density data sources and how the database was
applied to the HSTT Study Area is detailed in the Navy Marine Species
Density Database Technical Report (http://hstteis.com/DocumentsandReferences/HSTTDocuments/SupportingTechnicalDocuments.aspx">hstteis.com/DocumentsandReferences/HSTTDocuments/SupportingTechnicalDocuments.aspx).
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
(e.g., 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, but rather
[[Page 6996]]
from ratios of pressures; the standard reference pressure for
underwater sound is 1 microPascal ([micro]Pa); for airborne sound, the
standard reference pressure is 20 [micro]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 [micro]Pa or, for airborne sound, 20
[micro]Pa). The logarithmic nature of the scale means that each 10-dB
increase is a ten-fold increase in acoustic power (and a 20-dB increase
is then a 100-fold increase in power; and a 30-dB increase is a 1,000-
fold increase in power). A ten-fold increase in acoustic power does not
mean that the sound is perceived as being ten times louder, however.
Humans perceive a 10-dB increase in sound level as a doubling of
loudness, and a 10-dB decrease in sound level as a halving of loudness.
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[micro]Pa) as a standard reference pressure unless noted otherwise.
It is important to note that decibel values underwater and decibel
values in air are not the same (different reference pressures and
densities/sound speeds between media) and should not be directly
compared. Because of the different densities of air and water and the
different decibel standards (i.e., reference pressures) in air and
water, a sound with the same level in air and in water would be
approximately 62 dB lower in air. Thus, a sound that measures 160 dB
(re 1 [micro]Pa) underwater would have the same approximate effective
level as a sound that is 98 dB (re 20 [micro]Pa) 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
(typically below 20 Hz) and ultrasonic (typically above 20,000 Hz)
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''; explosives are an example of a
broadband sound source and active 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 behavioral
protocols or auditory evoked potential (AEP) techniques, anatomical
modeling, and other data, Southall et al. (2007) designate ``functional
hearing groups'' for marine mammals 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
(which are derived from the audiograms described above; see Figure 1 in
Southall et al., 2007) developed for each broad group. The functional
groups and the associated frequencies are indicated below (though,
again, animals are less sensitive to sounds at the outer edge of their
functional range and most sensitive to sounds of frequencies within a
smaller range somewhere in the middle of their functional hearing
range):
Low-frequency cetaceans--functional hearing is estimated
to occur between approximately 7 Hz and 30 kHz;
Mid-frequency cetaceans--functional hearing is estimated
to occur between approximately 150 Hz and 160 kHz;
High-frequency cetaceans--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.
The estimated hearing range for low-frequency cetaceans has been
extended slightly from previous analyses (from 22 to 30 kHz). This
decision is based on data from Watkins et al. (1986) for numerous
mysticete species, Au et al. (2006) for humpback whales, an abstract
from Frankel (2005) and paper from Lucifredi and Stein (2007) on gray
whales, and an unpublished report (Ketten and Mountain, 2009) and
abstract (Tubelli et al., 2012) for minke whales. As more data from
more species and/or individuals become available, these estimated
hearing ranges may require modification.
When sound travels (propagates) from its source, its loudness
decreases as the distance traveled by the sound increases. Thus, the
loudness of a sound at its source is higher than the loudness of that
same sound a kilometer away. Acousticians often refer to the loudness
of a sound at its source (typically referenced to one meter from the
source) as the source level and the loudness of sound elsewhere as the
received level (i.e., typically the receiver). For example, a humpback
whale 3 km from a device that has a source level of 230 dB may only be
exposed to sound that is 160 dB loud, depending on how the sound
travels through water (e.g., spherical spreading [3 dB reduction with
doubling of distance] was used in this example). As a result, it is
important to understand the difference between source levels and
received levels when discussing the loudness of sound in the ocean or
its impacts on the marine environment.
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 active 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 to describe sound levels in the discussions of
acoustic effects in this document.
Sound pressure level (SPL)--Sound pressure is the sound force per
unit area, and is usually measured in micropascals ([micro]Pa), where 1
Pa is the pressure resulting from a force of one newton exerted over an
area of one square meter. SPL is expressed as the ratio of a measured
sound pressure and a reference level.
[[Page 6997]]
SPL (in dB) = 20 log (pressure/reference pressure)
The commonly used reference pressure level in underwater acoustics
is 1 [micro]Pa, and the units for SPLs are dB re: 1 [micro]Pa. SPL is
an instantaneous pressure measurement and can be expressed as the peak,
the peak-peak, or the root mean square (rms). Root mean square
pressure, 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 exposure 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).
Sound exposure level (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 [micro]Pa\2\-s. Below is a simplified
formula for SEL.
SEL = SPL + 10log(duration in seconds)
As applied to active 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 cumulative SEL. The cumulative 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 as cumulative SEL.
Potential Effects of Specified Activities on Marine Mammals
The Navy has requested authorization for the take of marine mammals
that may occur incidental to training and testing activities in the
Study Area. The Navy has analyzed potential impacts to marine mammals
from impulsive and non-impulsive sound sources and vessel strike.
Other potential impacts to marine mammals from training activities
in the Study Area were analyzed in the Navy's HSTT DEIS/OEIS, in
consultation with NMFS as a cooperating agency, and determined to be
unlikely to result in marine mammal harassment. Therefore, the Navy has
not requested authorization for take of marine mammals that might occur
incidental to other components of their proposed activities. In this
document, NMFS analyzes the potential effects on marine mammals from
exposure to non-impulsive sound sources (sonar and other active
acoustic sources), impulsive sound sources (underwater detonations and
pile driving), and vessel strikes.
For the purpose of MMPA authorizations, NMFS' effects assessments
serve four primary purposes: (1) To prescribe the permissible methods
of taking (i.e., Level B harassment (behavioral harassment), Level A
harassment (injury), or mortality, including an identification of the
number and types of take that could occur by harassment or mortality)
and to prescribe other means of effecting the least practicable adverse
impact on such species or stock and its habitat (i.e., mitigation); (2)
to determine whether the specified activity would have a negligible
impact on the affected species or stocks of marine mammals (based on
the likelihood that the activity would adversely affect the species or
stock through effects on annual rates of recruitment or survival); (3)
to determine whether the specified activity would have an unmitigable
adverse impact on the availability of the species or stock(s) for
subsistence uses; and (4) to prescribe requirements pertaining to
monitoring and reporting.
More specifically, for activities involving non-impulsive or
impulsive sources, NMFS' 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 (effects to
social relationships) that would be classified as a take and whether
such take would have a negligible impact on such species or stocks.
Vessel strikes, which have the potential to result in incidental take
from direct injury and/or mortality, will be discussed in more detail
in the Estimated Take of Marine Mammals section. In this section, we
will focus qualitatively on the different ways that non-impulsive and
impulsive sources may affect marine mammals (some of which NMFS would
not classify as harassment). Then, in the Estimated Take of Marine
Mammals section, we will relate the potential effects to marine mammals
from non-impulsive and impulsive sources to the MMPA definitions of
Level A and Level B Harassment, along with the potential effects from
vessel strikes, and attempt to quantify those effects.
Non-Impulsive Sources
Direct Physiological Effects
Based on the literature, there are two basic ways that non-
impulsive sources 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 detect them) following exposure to an intense sound or sound
for long duration, 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 complete recovery), can occur 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 initially by only 6 dB or reduced by 30 dB). PTS is
permanent, but some recovery is possible. PTS can also occur in a
specific frequency range and amount as mentioned above for TTS.
The following physiological mechanisms are thought to play a role
in inducing auditory TS: 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 can 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, along with the recovery time. For intermittent
sounds, less TS could occur than compared to a continuous exposure with
the same energy (some recovery could occur between intermittent
exposures depending on the duty cycle between sounds) (Kryter et al.,
1966; Ward, 1997). For example, one short but loud (higher SPL) sound
exposure may
[[Page 6998]]
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, prolonged exposure to sounds 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 mid- and high-frequency active sonar
(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
marine mammals, published data are limited to the captive bottlenose
dolphin, beluga, harbor porpoise, and Yangtze finless porpoise
(Finneran et al., 2000, 2002b, 2003, 2005a, 2007, 2010a, 2010b;
Finneran and Schlundt, 2010; Lucke et al., 2009; Mooney et al., 2009a,
2009b; Popov et al., 2011a, 2011b; Kastelein et al., 2012a; Schlundt et
al., 2000; Nachtigall et al., 2003, 2004). For pinnipeds in water, data
are limited to measurements of TTS in harbor seals, an elephant seal,
and California sea lions (Kastak et al., 1999, 2005; Kastelein et al.,
2012b).
Marine mammal hearing plays a critical role in communication with
conspecifics, and interpretation of environmental cues for purposes
such as predator avoidance and prey capture. Depending on the degree
(elevation of threshold in dB), duration (i.e., recovery time), 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 occurs
during a time 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 permanent condition. Of note,
reduced hearing sensitivity as a simple function of 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.
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 or explosion
sounds would be long enough to drive bubble growth to any substantial
size, if such a phenomenon occurs. 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 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. Alternatively, Tyack et al. (2006) studied the deep
diving behavior of beaked whales and concluded that: ``Using current
models of breath-hold diving, we infer that their natural diving
behavior is inconsistent with known problems of acute nitrogen
supersaturation and embolism.'' 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 non-
impulsive sources can lead to strandings is included in the Stranding
and Mortality section.
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
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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 communicate (Zaitseva et al.,1980). A
recent study by Nachtigall and Supin (2008) showed that false killer
whales adjust their hearing to compensate for ambient sounds and the
intensity of returning echolocation signals.
As mentioned previously, the functional hearing ranges of
mysticetes, odontocetes, and pinnipeds underwater all encompass the
frequencies of the sonar sources used in the Navy's MFAS/HFAS training
exercises. Additionally, almost all species' vocal repertoires span
across the frequencies of these 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. For hull-mounted sonar,
which accounts for the largest takes of marine mammals (because of the
source strength and number of hours it's conducted), the pulse length
and low duty cycle of the MFAS/HFAS signal makes it less likely that
masking would occur as a result.
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 is more important than simply
detecting that a vocalization is occurring (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
adjustments to their vocalizations to increase the signal-to-noise
ratio, active space, and recognizability/distinguishability of their
vocalizations in the face of temporary changes in background noise
(Brumm et al., 2004; Patricelli et al., 2006). Vocalizing animals can
make adjustments to vocalization characteristics such as the frequency
structure, amplitude, temporal structure, and temporal delivery.
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
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
responses.
In the case of many stressors, an animal's first and sometimes 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
sympathetic part of 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 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
[[Page 7000]]
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), 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. Note that these examples involved a long-
term (days or weeks) stress response exposure to stimuli.
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses have also been documented
fairly well through controlled experiments; 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). Information has also been collected on the physiological
responses of marine mammals to exposure to anthropogenic sounds (Fair
and Becker, 2000; Romano et al., 2002; Wright et al., 2008). For
example, Rolland et al. (2012) found that noise reduction from reduced
ship traffic in the Bay of Fundy was associated with decreased stress
in North Atlantic right whales. In a conceptual model developed by the
Population Consequences of Acoustic Disturbance (PCAD) working group,
serum hormones were identified as possible indicators of behavioral
effects that are translated into altered rates of reproduction and
mortality. The Office of Naval Research hosted a workshop (Effects of
Stress on Marine Mammals Exposed to Sound) in 2009 that focused on this
very topic (ONR, 2009).
Studies of other marine animals and terrestrial animals would also
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 high frequency, 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), for example,
identified noise-induced physiological transient stress responses in
hearing-specialist fish (i.e., goldfish) 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 marine mammals 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 marine
mammals 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. Many different variables can influence an animal's perception
of and response to (nature and magnitude) an acoustic event. An
animal's prior experience with a sound or sound source 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 affect 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.
Exposure of marine mammals to sound sources can result in no
response or responses including, but not limited to: increased
alertness; orientation or attraction to a sound source; vocal
modifications; cessation of feeding;
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cessation of social interaction; alteration of movement or diving
behavior; habitat abandonment (temporary or permanent); and, in severe
cases, panic, flight, stampede, or stranding, potentially resulting in
death (Southall et al., 2007). A review of marine mammal responses to
anthropogenic sound was first conducted by Richardson and others in
1995. A more recent review (Nowacek et al., 2007) addresses studies
conducted since 1995 and focuses on observations where the received
sound level of the exposed marine mammal(s) was known or could be
estimated. The following sub-sections provide examples of behavioral
responses that provide an idea of the variability in behavioral
responses that would be expected given the differential sensitivities
of marine mammal species to sound and the wide range of potential
acoustic sources to which a marine mammal may be exposed. Estimates of
the types of behavioral responses that could occur for a given sound
exposure should be determined from the literature that is available for
each species, or extrapolated from closely related species when no
information exists.
Flight Response--A flight response is a dramatic change in normal
movement to a directed and rapid movement away from the perceived
location of a sound source. Relatively little information on flight
responses of marine mammals to anthropogenic signals exist, although
observations of flight responses to the presence of predators have
occurred (Connor and Heithaus, 1996). Flight responses have been
speculated as being a component of marine mammal strandings associated
with sonar activities (Evans and England, 2001).
Response to Predator--Evidence suggests that at least some marine
mammals have the ability to acoustically identify potential predators.
For example, harbor seals that reside in the coastal waters off British
Columbia are frequently targeted by certain groups of killer whales,
but not others. The seals discriminate between the calls of threatening
and non-threatening killer whales (Deecke et al., 2002), a capability
that should increase survivorship while reducing the energy required
for attending to and responding to all killer whale calls. The
occurrence of masking or hearing impairment provides a means by which
marine mammals may be prevented from responding to the acoustic cues
produced by their predators. Whether or not this is a possibility
depends on the duration of the masking/hearing impairment and the
likelihood of encountering a predator during the time that predator
cues are impeded.
Diving--Changes in dive behavior can vary widely. They may consist
of increased or decreased dive times and surface intervals as well as
changes in the rates of ascent and descent during a dive. Variations in
dive behavior may reflect interruptions in biologically significant
activities (e.g., foraging) or they may be of little biological
significance. Variations in dive behavior may also expose an animal to
potentially harmful conditions (e.g., increasing the chance of ship-
strike) or may serve as an avoidance response that enhances
survivorship. The impact of a variation in diving resulting from an
acoustic exposure depends on what the animal is doing at the time of
the exposure and the type and magnitude of the response.
Nowacek et al. (2004) reported disruptions of dive behaviors in
foraging North Atlantic right whales when exposed to an alerting
stimulus, an action, they noted, that could lead to an increased
likelihood of ship strike. However, the whales did not respond to
playbacks of either right whale social sounds or vessel noise,
highlighting the importance of the sound characteristics in producing a
behavioral reaction. Conversely, Indo-Pacific humpback dolphins have
been observed to dive for longer periods of time in areas where vessels
were present and/or approaching (Ng and Leung, 2003). In both of these
studies, the influence of the sound exposure cannot be decoupled from
the physical presence of a surface vessel, thus complicating
interpretations of the relative contribution of each stimulus to the
response. Indeed, the presence of surface vessels, their approach, and
speed of approach, seemed to be significant factors in the response of
the Indo-Pacific humpback dolphins (Ng and Leung, 2003). Low frequency
signals of the Acoustic Thermometry of Ocean Climate (ATOC) sound
source were not found to affect dive times of humpback whales in
Hawaiian waters (Frankel and Clark, 2000) or to overtly affect elephant
seal dives (Costa et al., 2003). They did, however, produce subtle
effects that varied in direction and degree among the individual seals,
illustrating the equivocal nature of behavioral effects and consequent
difficulty in defining and predicting them.
Due to past incidents of beaked whale strandings associated with
sonar operations, feedback paths are provided between avoidance and
diving and indirect tissue effects. This feedback accounts for the
hypothesis that variations in diving behavior and/or avoidance
responses can possibly result in nitrogen tissue supersaturation and
nitrogen off-gassing, possibly to the point of deleterious vascular
bubble formation (Jepson et al., 2003). Although hypothetical,
discussions surrounding this potential process are controversial.
Foraging--Disruption of feeding behavior can be difficult to
correlate with anthropogenic sound exposure, so it is usually inferred
by observed displacement from known foraging areas, the appearance of
secondary indicators (e.g., bubble nets or sediment plumes), or changes
in dive behavior. Noise from seismic surveys was not found to impact
the feeding behavior in western grey whales off the coast of Russia
(Yazvenko et al., 2007) and sperm whales engaged in foraging dives did
not abandon dives when exposed to distant signatures of seismic airguns
(Madsen et al., 2006). Balaenopterid whales exposed to moderate low-
frequency signals similar to the ATOC sound source demonstrated no
variation in foraging activity (Croll et al., 2001), whereas five out
of six North Atlantic right whales exposed to an acoustic alarm
interrupted their foraging dives (Nowacek et al., 2004). Although the
received sound pressure levels were similar in the latter two studies,
the frequency, duration, and temporal pattern of signal presentation
were different. These factors, as well as differences in species
sensitivity, are likely contributing factors to the differential
response. A determination of whether foraging disruptions incur fitness
consequences will require information on or estimates of the energetic
requirements of the individuals and the relationship between prey
availability, foraging effort and success, and the life history stage
of the animal.
Breathing--Variations in respiration naturally vary with different
behaviors and variations in respiration rate as a function of acoustic
exposure can be expected to co-occur with other behavioral reactions,
such as a flight response or an alteration in diving. However,
respiration rates in and of themselves may be representative of
annoyance or an acute stress response. Mean exhalation rates of gray
whales at rest and while diving were found to be unaffected by seismic
surveys conducted adjacent to the whale feeding grounds (Gailey et al.,
2007). Studies with captive harbor porpoises showed increased
respiration rates upon introduction of acoustic alarms (Kastelein et
al., 2001; Kastelein et al., 2006a) and emissions for underwater data
transmission (Kastelein et al., 2005). However, exposure of the same
[[Page 7002]]
acoustic alarm to a striped dolphin under the same conditions did not
elicit a response (Kastelein et al., 2006a), again highlighting the
importance in understanding species differences in the tolerance of
underwater noise when determining the potential for impacts resulting
from anthropogenic sound exposure.
Social relationships--Social interactions between mammals can be
affected by noise via the disruption of communication signals or by the
displacement of individuals. Disruption of social relationships
therefore depends on the disruption of other behaviors (e.g., caused
avoidance, masking, etc.) and no specific overview is provided here.
However, social disruptions must be considered in context of the
relationships that are affected. Long-term disruptions of mother/calf
pairs or mating displays have the potential to affect the growth and
survival or reproductive effort/success of individuals, respectively.
Vocalizations (also see Masking Section)--Vocal changes in response
to anthropogenic noise can occur across the repertoire of sound
production modes used by marine mammals, such as whistling,
echolocation click production, calling, and singing. Changes may result
in response to a need to compete with an increase in background noise
or may reflect an increased vigilance or startle response. For example,
in the presence of low-frequency active sonar, humpback whales have
been observed to increase the length of their ``songs'' (Miller et al.,
2000; Fristrup et al., 2003), possibly due to the overlap in
frequencies between the whale song and the low-frequency active sonar.
A similar compensatory effect for the presence of low-frequency vessel
noise has been suggested for right whales; right whales have been
observed to shift the frequency content of their calls upward while
reducing the rate of calling in areas of increased anthropogenic noise
(Parks et al., 2007). Killer whales off the northwestern coast of the
U.S. have been observed to increase the duration of primary calls once
a threshold in observing vessel density (e.g., whale watching) was
reached, which has been suggested as a response to increased masking
noise produced by the vessels (Foote et al., 2004). In contrast, both
sperm and pilot whales potentially ceased sound production during the
Heard Island feasibility test (Bowles et al., 1994), although it cannot
be absolutely determined whether the inability to acoustically detect
the animals was due to the cessation of sound production or the
displacement of animals from the area.
Avoidance--Avoidance is the displacement of an individual from an
area as a result of the presence of a sound. Richardson et al., (1995)
noted that avoidance reactions are the most obvious manifestations of
disturbance in marine mammals. It is qualitatively different from the
flight response, but also differs in the magnitude of the response
(i.e., directed movement, rate of travel, etc.). Oftentimes avoidance
is temporary, and animals return to the area once the noise has ceased.
Longer term displacement is possible, however, which can lead to
changes in abundance or distribution patterns of the species in the
affected region if they do not become acclimated to the presence of the
sound (Blackwell et al., 2004; Bejder et al., 2006; Teilmann et al.,
2006). Acute avoidance responses have been observed in captive
porpoises and pinnipeds exposed to a number of different sound sources
(Kastelein et al., 2001; Finneran et al., 2003; Kastelein et al.,
2006a; Kastelein et al., 2006b). Short-term avoidance of seismic
surveys, low frequency emissions, and acoustic deterrents have also
been noted in wild populations of odontocetes (Bowles et al., 1994;
Goold, 1996; 1998; Stone et al., 2000; Morton and Symonds, 2002) and to
some extent in mysticetes (Gailey et al., 2007), while longer term or
repetitive/chronic displacement for some dolphin groups and for
manatees has been suggested to be due to the presence of chronic vessel
noise (Haviland-Howell et al., 2007; Miksis-Olds et al., 2007).
Maybaum (1993) conducted sound playback experiments to assess the
effects of MFAS on humpback whales in Hawaiian waters. Specifically,
she exposed focal pods to sounds of a 3.3-kHz sonar pulse, a sonar
frequency sweep from 3.1 to 3.6 kHz, and a control (blank) tape while
monitoring behavior, movement, and underwater vocalizations. The two
types of sonar signals (which both contained mid- and low-frequency
components) differed in their effects on the humpback whales, but both
resulted in avoidance behavior. The whales responded to the pulse by
increasing their distance from the sound source and responded to the
frequency sweep by increasing their swimming speeds and track
linearity. In the Caribbean, sperm whales avoided exposure to mid-
frequency submarine sonar pulses, in the range of 1000 Hz to 10,000 Hz
(IWC 2005).
Kvadsheim et al., (2007) conducted a controlled exposure experiment
in which killer whales fitted with D-tags were exposed to mid-frequency
active sonar (Source A: a 1.0 second upsweep 209 dB @ 1-2 kHz every 10
seconds for 10 minutes; Source B: with a 1.0 second upsweep 197 dB @ 6-
7 kHz every 10 seconds for 10 minutes). When exposed to Source A, a
tagged whale and the group it was traveling with did not appear to
avoid the source. When exposed to Source B, the tagged whales along
with other whales that had been carousel feeding, ceased feeding during
the approach of the sonar and moved rapidly away from the source. When
exposed to Source B, Kvadsheim and his co-workers reported that a
tagged killer whale seemed to try to avoid further exposure to the
sound field by the following behaviors: immediately swimming away
(horizontally) from the source of the sound; engaging in a series of
erratic and frequently deep dives that seemed to take it below the
sound field; or swimming away while engaged in a series of erratic and
frequently deep dives. Although the sample sizes in this study are too
small to support statistical analysis, the behavioral responses of the
orcas were consistent with the results of other studies.
In 2007, the first in a series of behavioral response studies, a
collaboration by the Navy, NMFS, and other scientists showed one beaked
whale (Mesoplodon densirostris) responding to an MFAS playback. Tyack
et al. (2011) indicates that the playback began when the tagged beaked
whale was vocalizing at depth (at the deepest part of a typical feeding
dive), following a previous control with no sound exposure. The whale
appeared to stop clicking significantly earlier than usual, when
exposed to mid-frequency signals in the 130-140 dB (rms) received level
range. After a few more minutes of the playback, when the received
level reached a maximum of 140-150 dB, the whale ascended on the slow
side of normal ascent rates with a longer than normal ascent, at which
point the exposure was terminated. The results are from a single
experiment and a greater sample size is needed before robust and
definitive conclusions can be drawn.
Tyack et al. (2011) also indicates that Blainville's beaked
whales--a resident species within the study area--appear to be
sensitive to noise at levels well below expected TTS (~160 dB
re1[micro]Pa). This sensitivity is manifest by an adaptive movement
away from a sound source. This response was observed irrespective of
whether the signal transmitted was within the band width of MFAS, which
suggests that beaked whales may not respond to the specific sound
signatures. Instead, they may be sensitive to any pulsed sound from a
[[Page 7003]]
point source in this frequency range. The response to such stimuli
appears to involve maximizing the distance from the sound source.
Results from a 2007-2008 study conducted near the Bahamas showed a
change in diving behavior of an adult Blainville's beaked whale to
playback of mid-frequency source and predator sounds (Boyd et al.,
2008; Tyack et al., 2011). Reaction to mid-frequency sounds included
premature cessation of clicking and termination of a foraging dive, and
a slower ascent rate to the surface. Preliminary results from a similar
behavioral response study in southern California waters have been
presented for the 2010-2011 field season (Southall et al., 2011).
Cuvier's beaked whale responses suggested particular sensitivity to
sound exposure as consistent with results for Blainville's beaked
whale. Similarly, beaked whales exposed to sonar during British
training exercises stopped foraging (DSTL 2007), and preliminary
results of controlled playback of sonar may indicate feeding/foraging
disruption of killer whales and sperm whales (Miller et al., 2011).
Orientation--A shift in an animal's resting state or an attentional
change via an orienting response represent behaviors that would be
considered mild disruptions if occurring alone. As previously
mentioned, the responses may co-occur with other behaviors; for
instance, an animal may initially orient toward a sound source, and
then move away from it. Thus, any orienting response should be
considered in context of other reactions that may occur.
There are few empirical studies of avoidance responses of free-
living cetaceans to MFAS. Much more information is available on the
avoidance responses of free-living cetaceans to other acoustic sources,
such as seismic airguns and low-frequency tactical sonar, than MFAS.
Behavioral Responses
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 human-made sound with the goal of proposing exposure
criteria for certain effects. This peer-reviewed compilation of
literature is very valuable, though Southall et al. (2007) note that
not all data are 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. All of the studies considered, however, contain an
estimate of the received sound level when the animal exhibited the
indicated response.
In the Southall et al. (2007) publication, for the purposes of
analyzing responses of marine mammals to anthropogenic sound and
developing criteria, 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
studies associated with low-frequency, mid-frequency, and high-
frequency cetacean and pinniped responses to non-pulse sounds, based
strictly on received level, in Appendix C of their article
(incorporated by reference and summarized in the three paragraphs
below).
The studies 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,
tactical low-frequency active sonar playback, drill ships, Acoustic
Thermometry of Ocean Climate (ATOC) source, and non-pulse playbacks.
These studies generally indicate no (or very limited) responses to
received levels in the 90 to 120 dB re: 1 [micro]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, few of
the laboratory or field datasets had common conditions, behavioral
contexts or sound sources, so it is not surprising that responses
differ.
The studies 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. (2007) were unable to come to a clear
conclusion regarding the results of these studies. 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 typically responded at lower
levels in the field).
The studies that address responses of high 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, AHDs, and various
laboratory non-pulse sounds. All of these data were collected from
harbor porpoises. Southall et al. (2007) concluded that the existing
data indicate that harbor porpoises are likely sensitive to a wide
range of anthropogenic sounds at low received levels (~ 90 to 120 dB),
at least for initial exposures. All recorded exposures above 140 dB
induced profound and sustained avoidance behavior in wild harbor
porpoises (Southall et al., 2007). Rapid habituation was noted in some
but not all studies. There is no data to indicate whether other high
frequency cetaceans are as sensitive to anthropogenic sound as harbor
porpoises are.
The studies 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, but 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, along with the assigned scores, 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
[[Page 7004]]
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
or 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)
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. 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
subconsciously (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 as
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 in undisturbed habitat gained body mass and had about
a 46-percent reproductive success rate compared with geese in disturbed
habitat (being consistently scared off the fields on which they were
foraging) which did not gain mass and had a 17-percent reproductive
success rate. Similar reductions in reproductive success have been
reported for mule deer 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 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 reported that
bears disturbed by hikers reduced their energy intake by an average of
12 kcal/minute (50.2 x 103kJ/minute), and spent energy
fleeing or acting aggressively toward hikers (White et al. 1999).
Alternately, Ridgway et al., (2006) reported that increased vigilance
in bottlenose dolphins exposed to sound over a 5-day period did not
cause any sleep deprivation or stress effects such as changes in
cortisol or epinephrine levels.
On a related note, many animals perform vital functions, such as
feeding, resting, traveling, and socializing, on a diel cycle (24-hour
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 1 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 response to the National Research Council of the National
Academies (2005) review, the Office of Naval Research founded a working
group to formalize the Population Consequences of Acoustic Disturbance
(PCAD) framework. The PCAD model connects observable data through a
series of transfer functions using a case study approach. The long-term
goal is to improve the understanding of how effects of sound on marine
mammals transfer between behavior and life functions and between life
functions and vital rates of individuals. Then, this understanding of
how disturbance can affect the vital rates of individuals will
facilitate the further assessment of the population level effects of
anthropogenic sound on marine mammals by providing a quantitative
approach to evaluate effects and the relationship between takes and
possible changes to adult survival and/or annual recruitment.
Stranding and Mortality
When a live or dead marine mammal swims or floats onto shore and
becomes
[[Page 7005]]
``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; NMFS, 2007). The legal definition for a stranding
within the U.S. is that (A) ``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 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 strandings 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
predispose them to 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). For reference, between 2001 and
2009, there was an annual average of 1,400 cetacean strandings and
4,300 pinniped strandings along the coasts of the continental U.S. and
Alaska (NMFS, 2011).
Several sources have published lists of mass stranding events of
cetaceans in an attempt 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 whale.
The IWC concluded that, out of eight stranding events reported from the
mid-1980s to the summer of 2003, seven had been coincident with the use
of tactical mid-frequency sonar, one of those seven had been associated
with the use of tactical 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 involving the use of tactical sonar.
Between 1960 and 2006, 48 strandings (68 percent) involved beaked
whales, three (4 percent) involved dolphins, and 14 (20 percent)
involved whale species. Cuvier's beaked whales were involved in the
greatest number of these events (48 or 68 percent), followed by sperm
whales (seven or 10 percent), and Blainville's and Gervais' beaked
whales (four each or 6 percent). Naval activities (not just activities
conducted by the U.S. Navy) that might have involved active sonar are
reported to have coincided with nine or 10 (13 to 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 seven were coincident
with naval exercises that were using MFAS.
Strandings Associated With Impulse Sound
During a Navy training event on March 4, 2011 at the Silver Strand
Training Complex in San Diego, California, three or possibly four
dolphins were killed in an explosion. During an underwater detonation
training event, a pod of 100 to 150 long-beaked common dolphins were
observed moving toward the 700-yd (640.1-m) exclusion zone around the
explosive charge, monitored by personnel in a safety boat and
participants in a dive boat. Approximately 5 minutes remained on a
time-delay fuse connected to a single 8.76 lb (3.97 kg) explosive
charge (C-4 and detonation cord). Although the dive boat was placed
between the pod and the explosive in an effort to guide the dolphins
away from the area, that effort was unsuccessful and three long-beaked
common dolphins near the explosion died. In addition to the three
dolphins found dead on March 4, the remains of a fourth dolphin were
discovered on March 7, 2011 near Ocean Beach, California (3 days later
and approximately 11.8 mi. [19 km] from Silver Strand where the
training event occurred), which might also have been related to this
event. Association of the fourth stranding with the training event is
uncertain because dolphins strand on a regular basis in the San Diego
area. Details such as the dolphins' depth and distance from the
explosive at the time of the detonation could not be estimated from the
250 yd (228.6 m) standoff point of the observers in the dive boat or
the safety boat.
These dolphin mortalities are the only known occurrence of a U.S.
Navy training or testing event involving impulse energy (underwater
detonation) that caused mortality or injury to a marine mammal. Despite
this being a rare occurrence, the Navy has reviewed training
requirements, safety procedures, and possible mitigation measures and
implemented changes to reduce the potential for this to occur in the
future. Discussions of procedures associated with these and other
training and testing events are presented in the Mitigation section.
Strandings Associated With MFAS
Over the past 16 years, there have been five stranding events
coincident with military mid-frequency sonar use in which exposure to
sonar is believed to have been a contributing factor: Greece (1996);
the Bahamas (2000); Madeira (2000); Canary Islands (2002); and Spain
(2006). Additionally, in 2004, during the Rim of the Pacific (RIMPAC)
exercises, between 150 and 200 usually pelagic melon-headed whales
occupied the shallow waters of Hanalei Bay, Kauai, Hawaii for over 28
hours. NMFS determined that MFAS was a plausible, if not likely,
contributing factor in what may have been a confluence of events that
led to the stranding. A number of other stranding events coincident
with the operation of mid-frequency sonar, including 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 and only one of these stranding events, the Bahamas (2000),
[[Page 7006]]
was associated with exercises conducted by the U.S. Navy.
Greece (1996)--Twelve Cuvier's beaked whales stranded atypically
(in both time and space) along a 38.2-km strand of the Kyparissiakos
Gulf coast on May 12 and 13, 1996 (Frantzis, 1998). From May 11 through
May 15, the North Atlantic Treaty Organization (NATO) research vessel
Alliance was conducting sonar tests with signals of 600 Hz and 3 kHz
and source levels of 228 and 226 dB re: 1[mu]Pa, respectively (D'Amico
and Verboom, 1998; D'Spain et al., 2006). The timing and location of
the testing encompassed the time and location of the 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.
Examination of photos of the animals, taken soon after their death,
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 event were compiled, and many potential causes were
examined including major pollution events, prominent tectonic activity,
unusual physical or meteorological events, 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 or space 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 inconsistent with pathogenic
causes. In addition, environmental causes can be ruled out as there
were no unusual environmental circumstances or events before or during
this time period and within the general proximity (Frantzis, 2004).
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 thought to be 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). A Bioacoustics Panel convened
by NATO concluded that the evidence available did not allow them to
accept or reject sonar exposures as a causal agent in these stranding
events. The analysis of this stranding event provided support for, but
no clear evidence for, the cause-and-effect relationship of tactical
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), seven animals died on the beach (five Cuvier's
beaked whales, one Blainville's beaked whale, and the spotted dolphin),
while the other 10 were returned to the water alive (though their
ultimate fate is unknown). As discussed in the Bahamas report (DOC/DON,
2001), there is no likely association between the minke whale and
spotted dolphin strandings and the operation of MFAS.
Necropsies were performed on five of the stranded 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 MFAS 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 MFAS aboard U.S. Navy
ships that were in use during the active sonar exercise in question
were the most plausible source of this acoustic or impulse trauma to
beaked whales. 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 active sonars. The investigation team
concluded that the cause of this stranding event was the confluence of
the Navy MFAS and these contributory factors working together, and
further recommended that the Navy avoid operating MFAS 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 operation of MFAS in situations where
surface ducts exist, or in marine environments defined by steep
bathymetry and/or constricted channels may increase the likelihood of
producing a sound field with the potential to cause cetaceans
(especially beaked whales) to strand, and therefore, suggests the need
for increased vigilance while operating MFAS in these areas, especially
when beaked whales (or potentially other deep divers) are likely
present.
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 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
[[Page 7007]]
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 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 (1,000 m) depth near a
shoreline where there is a rapid change in bathymetry on the order of
547 to 3,281 fathoms (1,000 to 6,000 m) occurring across a relatively
short horizontal distance (Freitas, 2004); multiple ships were
operating around Madeira, though it is not known if MFAS was used, and
the specifics of the sound sources used are unknown (Cox et al., 2006,
Freitas, 2004); and 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 involving multiple ships
employing MFAS 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 (1,000 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 three
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 MFAS
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 MFAS 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 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; Fern[aacute]ndez et al., 2005).
Hanalei Bay (2004)--On July 3 and 4, 2004, approximately 150 to 200
melon-headed whales occupied the shallow waters of the Hanalei Bay,
Kaua'i, Hawaii for over 28 hrs. 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. Cause of death could not be
definitively determined, but 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 animals' movement into the Bay and
subsequent milling and re-grouping may have contributed to the
separation or lack of nursing, especially if the maternal bond was weak
or this was an inexperienced mother with her first 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 and dissimilar to
sites that have been associated with mass strandings in other parts of
the U.S. 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, occurrence of predator or prey
species, or unusual harmful algal blooms, although Mobley et al., 2007
suggested that the full moon cycle that occurred at that time may have
influenced a run of squid into the Bay. Weather patterns and bathymetry
that have been associated with mass
[[Page 7008]]
strandings elsewhere were not found to occur in this instance.
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. 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 suggests 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. 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 the following:
(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.
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 to 700 melon-headed whales came into
Sasanhaya Bay on July 4, 2004, near 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. The Rota incident led to
scientific debate regarding what, if any, relationship the event had to
the simultaneous events in Hawaii and whether they might be related by
some common factor (e.g., there was a full moon on July 2, 2004, as
well as during other melon-headed whale strandings and nearshore
aggregations (Brownell et al., 2009; Lignon et al., 2007; Mobley et
al., 2007). Brownell et al. (2009) compared the two incidents, along
with one other stranding incident at Nuka Hiva in French Polynesia and
normal resting behaviors observed at Palmyra Island, in regard to
physical features in the areas, melon-headed whale behavior, and lunar
cycles. Brownell et al., (2009) concluded that the rapid entry of the
whales into Hanalei Bay, their movement into very shallow water far
from the 100-m contour, their milling behavior (typical pre-stranding
behavior), and their reluctance to leave the bay constituted an unusual
event that was not similar to the events that occurred at Rota (but was
similar to the events at Palmyra), which appear to be similar to
observations of melon-headed whales resting normally at Palmyra Island.
Additionally, there was no correlation between lunar cycle and the
types of behaviors observed in the Brownell et al. (2009) examples.
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 first three animals were located near the
town of Mojacar and the fourth animal was found dead, a few kilometers
north of the first three animals. From January 25-26, 2006, Standing
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 (1,000 m) depth near a shoreline where there is a
rapid change in bathymetry on the order of 547 to 3,281 fathoms (1,000
to 6,000 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; and exercises took place in an area
surrounded by landmasses, or in an embayment. Exercises involving
multiple ships employing MFAS 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).
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 MFAS (Cox et al., 2006, D'Spain et al., 2006).
Although Cuvier's
[[Page 7009]]
beaked whales have been the most common species involved in these
stranding events (81 percent of the total number of stranded animals),
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 MFAS 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 grouping of risk
factors probably contribute to these stranding events.
Behaviorally Mediated Responses to MFAS That May Lead to Stranding
Although the confluence of Navy MFAS 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 (e.g.,
acoustically mediated bubble growth, as addressed above) prior to
stranding or whether a behavioral response to sound occurred that
ultimately caused the beaked whales to 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 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 three mechanisms by which the behavioral responses of
beaked whales upon being exposed to active sonar might result in a
stranding event. These include the following: 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 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; (2) relatively slow, controlled ascents;
and (3) a series of ``bounce'' dives between 100 and 400 m 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.
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
[[Page 7010]]
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). Baird et al.
(2008), in a beaked whale tagging study off Hawaii, showed that deep
dives are equally common during day or night, but ``bounce dives'' are
typically a daytime behavior, possibly associated with visual predator
avoidance. This may indicate that ``bounce dives'' are associated with
something other than behavioral regulation of dissolved nitrogen
levels, which would be necessary day and night.
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 there
is either scientific disagreement or a lack of information regarding
each of 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 introduced by decomposition before
sampling, handling, freezing, or necropsy procedures affect
interpretation of observed lesions.
Impulsive Sources
Underwater explosive detonations send a shock wave and sound energy
through the water and can release gaseous by-products, create an
oscillating bubble, or cause a plume of water to shoot up from the
water surface. The shock wave and accompanying 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 greater impacts to an individual animal.
Injuries resulting from a shock wave take place at boundaries
between tissues of different densities. 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 sound energy from detonations can be theoretically
distinct from injury from the shock wave, particularly farther from the
explosion. If a noise is audible to an animal, it has the potential to
damage the animal's hearing by causing decreased sensitivity (Ketten,
1995). 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 compared to MFAS/HFAS. However, though the
nature of the sound waves emitted from an explosion are different (in
shape and rise time) from MFAS/HFAS, we still anticipate the same sorts
of behavioral responses to result from repeated explosive detonations
(a smaller range of likely less severe responses (i.e., not rising to
the level of MMPA harassment) would be expected to occur as a result of
exposure to a single explosive detonation that was not powerful enough
or close enough to the animal to cause TTS or injury).
Vessel Strike
Commercial and Navy ship strikes of cetaceans can cause major
wounds, which may lead to the death of the animal. An animal at the
surface could be struck directly by a vessel, a surfacing animal could
hit the bottom of a vessel, or an animal just below the surface could
be cut by a vessel's propeller. The severity of injuries typically
depends on the size and speed of the vessel (Knowlton and Kraus, 2001;
Laist et al., 2001; Vanderlaan and Taggart, 2007). The most vulnerable
marine mammals are those that spend extended periods of time at the
surface in order to restore oxygen levels within their tissues after
deep dives (e.g., the sperm whale). In addition, some baleen whales,
such as the North Atlantic right whale, seem generally unresponsive to
vessel sound, making them more susceptible to vessel collisions
(Nowacek et al., 2004). These species are primarily large, slow moving
whales. Smaller marine mammals (e.g., bottlenose dolphin) move quickly
through the water column and are often seen riding the bow wave of
large ships. Marine mammal responses to vessels
[[Page 7011]]
may include avoidance and changes in dive pattern (NRC, 2003).
An examination of all known ship strikes from all shipping sources
(civilian and military) indicates vessel speed is a principal factor in
whether a vessel strike results in death (Knowlton and Kraus, 2001;
Laist et al., 2001; Jensen and Silber, 2003; Vanderlaan and Taggart,
2007). In assessing records in which vessel speed was known, Laist et
al. (2001) found a direct relationship between the occurrence of a
whale strike and the speed of the vessel involved in the collision. The
authors concluded that most deaths occurred when a vessel was traveling
in excess of 13 knots.
Jensen and Silber (2003) detailed 292 records of known or probable
ship strikes of all large whale species from 1975 to 2002. Of these,
vessel speed at the time of collision was reported for 58 cases. Of
these cases, 39 (or 67 percent) resulted in serious injury or death (19
of those resulted in serious injury as determined by blood in the
water, propeller gashes or severed tailstock, and fractured skull, jaw,
vertebrae, hemorrhaging, massive bruising or other injuries noted
during necropsy and 20 resulted in death). Operating speeds of vessels
that struck various species of large whales ranged from 2 to 51 knots.
The majority (79 percent) of these strikes occurred at speeds of 13
knots or greater. The average speed that resulted in serious injury or
death was 18.6 knots. Pace and Silber (2005) found that the probability
of death or serious injury increased rapidly with increasing vessel
speed. Specifically, the predicted probability of serious injury or
death increased from 45 to 75 percent as vessel speed increased from 10
to 14 knots, and exceeded 90 percent at 17 knots. Higher speeds during
collisions result in greater force of impact, but higher speeds also
appear to increase the chance of severe injuries or death by pulling
whales toward the vessel. Computer simulation modeling showed that
hydrodynamic forces pulling whales toward the vessel hull increase with
increasing speed (Clyne, 1999; Knowlton et al., 1995).
The Jensen and Silber (2003) report notes that the database
represents a minimum number of collisions, because the vast majority
probably goes undetected or unreported. In contrast, Navy vessels are
likely to detect any strike that does occur, and they are required to
report all ship strikes involving marine mammals. Overall, the
percentages of Navy traffic relative to overall large shipping traffic
are very small (on the order of 2 percent).
Over a period of 20 years from 1991 to 2010 there have been a total
of 16 Navy vessel strikes in SOCAL, and five Navy vessel strikes in
HRC. Two of the five HRC Navy strikes were by smaller workboats (less
than 12 m in length), versus larger Navy ships. In terms of the 16
consecutive 5-year periods in the last 20 years, no single 5-year
period exceeded ten whales struck within SOCAL and HRC (periods from
2000-2004 and 2001-2005). For Navy vessel strikes in SOCAL, there were
six consecutive 5-year periods with six or more whales struck (1997-
2001, 1998-2002, 1999-2003, 2000-2004, 2001-2005, and 2002-2006), and
no more than three whales struck in the last 5-year period from 2006-
2010. No whales have been struck by Navy vessels in SOCAL since 2009.
For Navy vessel strikes in the HRC for the same time period, there was
one 5-year period when three whales were struck (2003-2007), seven
periods when two whales were struck, five periods when one whale was
struck, and three periods when no whales were struck. Within the data
set analyzed for HRC through 2010, no whales have been struck by a Navy
vessel since 2008.
Mitigation
In order to issue an incidental take authorization 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 NDAA of 2004 amended the MMPA as
it relates to military-readiness activities and the ITA 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 and
testing activities described in the Navy's LOA application are
considered military readiness activities.
NMFS reviewed the proposed activities and the proposed mitigation
measures as described in the Navy's LOA application to determine if
they would result in the least practicable adverse effect on marine
mammals, which includes 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 effectiveness of the ``military-readiness activity.''
Included below are the mitigation measures the Navy proposed in their
LOA application.
Proposed Mitigation Measures
They Navy's proposed mitigation measures are modifications to the
proposed activities that are implemented for the sole purpose of
reducing a specific potential environmental impact on a particular
resource. These do not include standard operating procedures, which are
established for reasons other than environmental benefit. Most of the
following proposed mitigation measures are currently, or were
previously, implemented as a result of past environmental compliance
documents. The Navy's overall approach to assessing potential
mitigation measures is based on two principles: (1) mitigation measures
will be effective at reducing potential impacts on the resource, and
(2) from a military perspective, the mitigation measures are
practicable, executable, and safety and readiness will not be impacted.
Lookouts
The use of lookouts is a critical component of Navy procedural
measures and implementation of mitigation zones. Navy lookouts 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 (OOD) (e.g., trash, a periscope, marine
mammals, sea turtles) and all disturbances (e.g., surface disturbance,
discoloration) that may be indicative of a threat to the vessel and its
crew. There are personnel standing watch on station at all times (day
and night) when a ship or surfaced submarine is moving through the
water.
The Navy would have two types of lookouts for the purposes of
conducting visual observations: (1) those positioned on surface ships,
and (2) those positioned in aircraft or on boats. Lookouts positioned
on surface ships would be dedicated solely to diligent observation of
the air and surface of the water. They would have multiple observation
objectives, which include but are not limited to detecting the presence
of biological resources and recreational or fishing boats, observing
mitigation zones, and monitoring for vessel and personnel safety
concerns.
Due to aircraft and boat manning and space restrictions, lookouts
positioned in aircraft or on boats would consist of the aircraft crew,
pilot, or boat crew. Lookouts positioned in aircraft and boats may
necessarily be responsible for tasks in addition to observing the air
or surface of the water (for example,
[[Page 7012]]
navigation of a helicopter or rigid hull inflatable boat). However,
aircraft and boat lookouts would, to the maximum extent practicable and
consistent with aircraft and boat safety and training and testing
requirements, comply with the observation objectives described above
for lookouts positioned on surface ships.
The Navy proposes to use at least one lookout during the training
and testing activities provided in Table 10. Additional details on
lookout procedures and implementation are provided in Chapter 11 of the
Navy's LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications).
Table 10--Lookout Mitigation Measures for Training and Testing
Activities Within the HSTT Study Area
------------------------------------------------------------------------
Training and testing
Number of lookouts activities Benefit
------------------------------------------------------------------------
4........................... Mine countermeasure Lookouts can
and neutralization visually detect
activities using marine mammals so
time delay would that potentially
use 4, depending on harmful impacts
the explosives from explosives use
being used. If can be avoided.
applicable, aircrew
and divers would
report sightings of
marine mammals.
Lookouts dedicated
to observations can
more quickly and
effectively relay
sighting
information so that
corrective action
can be taken.
Support from
aircrew and divers,
if they have are
involved, would
increase the
probability of
sightings, reducing
the potential for
impacts.
1 to 2...................... Vessels using low- Lookouts can
frequency active visually detect
sonar or hull- marine mammals so
mounted mid- that potentially
frequency active harmful impacts
sonar associated from Navy sonar and
with ASW activities explosives use can
would have either be avoided.
one or two Dedicated lookouts
lookouts, depending can more quickly
on the size and and effectively
status/location of relay sighting
the vessel. information so that
corrective action
can be taken.
Support from
aircrew and divers,
if they are
involved, would
increase the
probability of
sightings, reducing
the potential for
impacts.
Mine countermeasure
and neutralization
activities with
positive control
would use one or
two lookouts
(depending on net
explosive weight),
with at least one
on each support
vessel. If
applicable, aircrew
and divers would
also report the
presence of marine
mammals.
Mine neutralization
activities
involving diver
placed charges of
up to 100 lb (45
kg) net explosive
weight detonation
would use two
lookouts.
Sinking exercises
would use two
lookouts (one in an
aircraft and one on
a vessel).
At sea explosives
testing would have
at least one
lookout.
1........................... Surface ships and Lookouts can
aircraft conducting visually detect
ASW, ASUW, or MIW marine mammals so
activities using that potentially
high-frequency harmful impacts
active sonar; non- from Navy sonar;
hull mounted mid- explosives;
frequency active sonobuoys; gunnery
sonar; helicopter rounds; missiles;
dipping mid- explosive
frequency active torpedoes; pile
sonar; anti-swimmer driving; towed
grenades; IEER systems; surface
sonobuoys; line vessel propulsion;
charge testing; and non-explosive
surface gunnery munitions can be
activities; surface avoided.
missile activities;
bombing activities;
explosive torpedo
testing; elevated
causeway system
pile driving; towed
in-water devices;
full power
propulsion testing
of surface vessels;
and activities
using non-explosive
practice munitions,
would have one
lookout.
------------------------------------------------------------------------
Personnel standing watch on the bridge, Commanding Officers,
Executive Officers, maritime patrol aircraft aircrews, anti-submarine
warfare helicopter crews, civilian equivalents, and lookouts would
complete the NMFS-approved Marine Species Awareness Training (MSAT)
prior to standing watch or serving as a lookout. Additional details on
the Navy's MSAT program are provided in Chapter 5 of the HSTT DEIS/
OEIS.
Mitigation Zones
The Navy proposes to use mitigation zones to reduce the potential
impacts to marine mammals from training and testing activities.
Mitigation zones are measured as the radius from a source and represent
a distance that the Navy would monitor. Mitigation zones are applied to
acoustic stressors (i.e., non-impulsive and impulsive sound) and
physical strike and disturbance (e.g., vessel movement and bombing
exercises). In each instance, visual detections of marine mammals would
be communicated immediately to a watch station for information
dissemination and appropriate action. Acoustic detections would be
communicated to lookouts posted in aircraft and on surface vessels.
Most of the current mitigation zones for activities that involve
the use of impulsive and non-impulsive sources were originally designed
to reduce the potential for onset of TTS. The Navy updated their
acoustic propagation modeling to incorporate new hearing threshold
metrics (i.e., upper and lower frequency limits), new marine mammal
density data, and factors such as an animal's likely presence at
various depths. An explanation of the acoustic propagation modeling
process can be found in the Marine Species Modeling Team Technical
Report (U.S. Department of the Navy 2012a).
As a result of updates to the acoustic propagation modeling, some
of the ranges to effects are larger than previous model outputs. Due to
the ineffectiveness of mitigating such large areas, the Navy is unable
to mitigate for onset of TTS during every activity. However, some
ranges to effects are smaller than previous models estimated, and the
mitigation zones were adjusted accordingly to provide consistency
across the measures. The Navy developed each proposed mitigation zone
to avoid or reduce the potential for
[[Page 7013]]
onset of the lowest level of injury, PTS, out to the predicted maximum
range. Mitigating to the predicted maximum range to PTS also mitigates
to the predicted maximum range to onset mortality (1 percent
mortality), onset slight lung injury, and onset slight gastrointestinal
tract injury, since the maximum range to effects for these criteria are
shorter than for PTS. Furthermore, in most cases, the predicted maximum
range to PTS also covers the predicted average range to TTS. Tables 11
and 12 summarize the predicted average range to TTS, average range to
PTS, maximum range to PTS, and recommended mitigation zone for each
activity category, based on the Navy's acoustic propagation modeling
results. It is important for the Navy to have standardized mitigation
zones wherever training and testing may be conducted. The information
in Tables 11 and 12 was developed in consideration of both Atlantic and
Pacific Ocean conditions, marine mammal species, environmental factors,
effectiveness, and operational assessments. Therefore, the ranges to
effects in Tables 11 and 12 provide effective values that ensure
appropriate mitigation ranges for both Atlantic Fleet and Pacific Fleet
activities, and may not align with range to effects values found in
other tables of the Navy's LOA application.
The Navy's proposed mitigation zones are based on the longest range
for all the marine mammal and sea turtle functional hearing groups.
Most mitigation zones were driven by the high-frequency cetaceans or
sea turtles functional hearing group. Therefore, the mitigation zones
are more conservative for the remaining functional hearing groups (low-
frequency and mid-frequency cetaceans, and pinnipeds), and likely cover
a larger portion of the potential range to onset of TTS. Additional
information on the estimated range to effects for each acoustic
stressor is detailed in Chapter 11 of the Navy's LOA application
(http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications).
Table 11--Predicted Ranges to TTS, PTS, and Recommended Mitigation Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bin (representative Predicted average Predicted average Predicted maximum Recommended
Activity category source)* range to TTS range to PTS range to PTS mitigation zone
--------------------------------------------------------------------------------------------------------------------------------------------------------
Non-Impulsive Sound
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-Frequency and Hull-Mounted Mid- MF1 (SQS-53 ASW hull- 4,251 yd. (3,887 m)... 281 yd. (257 m)...... <292 yd. (<267 m).... 6 dB power down at
Frequency Active Sonar \1\. mounted sonar). 1,000 yd. (914 m); 4
dB power down at 500
yd. (457 m); and
shutdown at 200 yd.
(183 m).
High-Frequency and Non-Hull Mounted MF4 (AQS-22 ASW 226 yd. (207 m)....... <55 yd. (<50 m)...... <55 yd. (<50 m)...... 200 yd. (183 m).
Mid-Frequency Active Sonar. dipping sonar).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Explosive and Impulsive Sound
--------------------------------------------------------------------------------------------------------------------------------------------------------
Improved Extended Echo Ranging E4 (Explosive 434 yd. (397 m)....... 156 yd. (143 m)...... 563 yd. (515 m)...... 600 yd. (549 m).
Sonobuoys. sonobuoy).
Explosive Sonobuoys using 0.6-2.5 E3 (Explosive 290 yd. (265 m)....... 113 yd. (103 m)...... 309 yd. (283 m)...... 350 yd. (320 m).
lb. NEW. sonobuoy).
Anti-Swimmer Grenades.............. E2 (Up to 0.5 lb. NEW) 190 yd. (174 m)....... 83 yd. (76 m)........ 182 yd. (167 m)...... 200 yd. (183 m).
--------------------------------------------------------------------------------------------------------------------
Mine Countermeasure and NEW dependent (see Table 12).
Neutralization Activities Using
Positive Control Firing Devices.
--------------------------------------------------------------------------------------------------------------------
Mine Neutralization Diver-Placed E6 (Up to 20 lb. NEW). 647 yd. (592 m)....... 232 yd. (212 m)...... 469 yd. (429 m)...... 1,000 yd. (915 m).
Mines Using Time-Delay Firing
Devices.
Ordnance Testing (Line Charge E4 (Numerous 5 lb. 434 yd. (397 m)....... 156 yd. (143 m)...... 563 yd. (515 m)...... 900 yd. (823 m).**
Testing). charges).
Gunnery Exercises--Small- and E2 (40 mm projectile). 190 yd. (174 m)....... 83 yd. (76 m)........ 182 yd. (167 m)...... 200 yd. (183 m).
Medium-Caliber (Surface Target).
Gunnery Exercises--Large-Caliber E5 (5 in. projectiles 453 yd. (414 m)....... 186 yd. (170 m)...... 526 yd. (481 m)...... 600 yd. (549 m).
(Surface Target). at the surface***).
Missile Exercises up to 250 lb. NEW E9 (Maverick missile). 949 yd. (868 m)....... 398 yd. (364 m)...... 699 yd. (639 m)...... 900 yd. (823 m).
(Surface Target).
Missile Exercises up to 500 lb. NEW E10 (Harpoon missile). 1,832 yd. (1,675 m)... 731 yd. (668 m)...... 1,883 yd. (1,721 m).. 2,000 yd. (1.8 km).
(Surface Target).
Bombing Exercises.................. E12 (MK-84 2,000 lb. 2,513 yd. (2.3 km).... 991 yd. (906 m)...... 2,474 yd. (2.3 km)... 2,500 yd. (2.3 km).**
bomb).
Torpedo (Explosive) Testing........ E11 (MK-48 torpedo)... 1,632 yd. (1.5 km).... 697 yd. (637 m)...... 2,021 yd. (1.8 km)... 2,100 yd. (1.9 km).
Sinking Exercises.................. E12 (Various sources 2,513 yd. (2.3 km).... 991 yd. (906 m)...... 2,474 yd. (2.3 km)... 2.5 nm.
up to the MK-84 2,000
lb. bomb).
[[Page 7014]]
At-Sea Explosive Testing........... E5 (Various sources 525 yd. (480 m)....... 204 yd. (187 m)...... 649 yd. (593 m)...... 1,600 yd. (1.4 km).**
less than 10 lb. NEW
at various depths***).
Elevated Causeway System--Pile 24 in. steel impact 1,094 yd. (1,000 m)... 51 yd. (46 m)........ 51 yd. (46 m)........ 60 yd. (55 m).
Driving. hammer.
--------------------------------------------------------------------------------------------------------------------------------------------------------
ASW: anti-submarine warfare; JAX: Jacksonville; NEW: net explosive weight; PTS: permanent threshold shift; TTS: temporary threshold shift.
\1\ The mitigation zone would be 200 yd for bin LF4 testing sources.
* This table does not provide an inclusive list of source bins; bins presented here represent the source bin with the largest range to effects within
the given activity category.
** Recommended mitigation zones are larger than the modeled injury zones to account for multiple types of sources or charges being used.
*** The representative source bin E5 has different range to effects depending on the depth of activity occurrence (at the surface or at various depths).
Table 12--Predicted Ranges to Effects and Mitigation Zone Radius for Mine Countermeasure and Neutralization Activities Using Positive Control Firing Devices
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
General mine countermeasure and neutralization activities using positive Mine countermeasure and neutralization activities using diver placed charges
control firing devices * under positive control **
Charge size net explosive weight ---------------------------------------------------------------------------------------------------------------------------------------------------------------
(bins) Predicted average Predicted average Predicted maximum Recommended Predicted average Predicted average Predicted maximum Recommended
range to TTS range to PTS range to PTS mitigation zone range to TTS range to PTS range to PTS mitigation zone
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
2.6-5 lb. (1.2-2.3 kg) (E4)..... 434 yd. (474 m)... 197 yd. (180 m)... 563 yd. (515 m)... 600 yd. (549 m)... 545 yd. (498 m)... 169 yd. (155 m)... 301 yd. (275 m)... 350 yd. (320 m).
6-10 lb. (2.7-4.5 kg) (E5)...... 525 yd. (480 m)... 204 yd. (187 m)... 649 yd. (593 m)... 800 yd. (732 m)... 587 yd. (537 m)... 203 yd. (185 m)... 464 yd. (424 m)... 500 yd. (457 m).
11-20 lb. (5-9.1 kg) (E6)....... 766 yd. (700 m)... 288 yd. (263 m)... 648 yd. (593 m)... 800 yd. (732 m)... 647 yd. (592 m)... 232 yd. (212 m)... 469 yd. (429 m)... 500 yd. (457 m).
21-60 lb. (9.5-27.2 kg) (E7) *** 1,670 yd. (1,527 581 yd. (531 m)... 964 yd. (882 m)... 1,200 yd. (1.1 km) 1,532 yd. (1,401 473 yd. (432 m)... 789 yd. (721 m)... 800 yd. (732 m).
m). m).
61-100 lb. (27.7-45.4 kg) (E8) 878 yd. (802 m)... 383 yd. (351 m)... 996 yd. (911 m)... 1,600 yd. (1.4 m). 969 yd. (886 m)... 438 yd. (400 m)... 850 yd. (777 m)... 850 yd. (777 m).
****.
250-500 lb. (113.4-226.8 kg) 1,832 yd. (1,675 731 yd. (668 m)... 1,883 yd. (1,721 2,000 yd. (1.8 km) .................. .................. .................. Not Applicable.
(E10). m). m).
501-650 lb. (227.3-294.8) (E11). 1,632 yd. (1,492 697 yd. (637 m)... 2,021 yd. (1,848 2,100 yd. (1.9 km) .................. .................. .................. Not Applicable.
m). m).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
PTS: permanent threshold shift; TTS: temporary threshold shift
* These mitigation zones are applicable to all mine countermeasure and neutralization activities conducted in all locations that Tables 2.8-1 through 2.8-5 specifies.
** These mitigation zones are only applicable to mine countermeasure and neutralization activities involving the use of diver placed charges. These activities are conducted in shallow water
and the mitigation zones are based only on the functional hearing groups with species that occur in these areas (mid-frequency cetaceans and sea turtles).
*** The E7 bin was only modeled in shallow-water locations so there is no difference for the diver placed charges category.
**** The E8 bin was only modeled for surface explosions, so some of the ranges are shorter than for sources modeled in the E7 bin which occur at depth.
When mine neutralization activities using diver placed charges (up
to a 20 lb. NEW) are conducted with a time-delay firing device, the
detonation is fused with a specified time-delay by the personnel
conducting the activity and is not authorized until the area is clear
at the time the fuse is initiated. During these activities, the
detonation cannot be terminated once the fuse is initiated due to human
safety concerns. The Navy is proposing to modify the number of lookouts
currently used for mine neutralization activities using diver-placed
time-delay firing devices. As a reference, the current mitigation
involves the use of six lookouts and three small rigid hull inflatable
boats (two lookouts positioned in each of the three boats) for
mitigation zones equal to or larger than 1,400 yd. (1,280 m), or four
lookouts and two boats for mitigation zones smaller than 1,400 yd.
(1,280 m), which was incorporated into the current Silver Strand
Training Complex IHA to minimize the possibility of take by serious
injury or mortality (which is not authorized under an IHA). The Navy
has determined that using six lookouts and three boats in the long term
is impracticable to implement from an operational standpoint due to the
impact that it is causing on resource requirements (i.e., limited
personnel resources and boat availability). During activities using up
to a 20 lb. NEW (bin E6) detonation, the Navy is proposing to have four
lookouts and two small rigid hull inflatable boats (two lookouts
positioned in each of the two boats) monitoring a 1,000-yd (915-m)
mitigation zone. In addition, when aircraft are used, the pilot or
member of the aircrew will serve as an additional lookout.
NMFS believes that the Navy's proposed modification to this
mitigation measure will still reduce the potential for injury or
mortality for a few reasons: (1) The Navy's acoustic propagation
modeling results show that the predicted ranges to TTS and PTS for mine
neutralization diver-placed mines using time-delay firing devices do
not exceed 647 yd (592 m), which is well within the proposed 1,000-yd
(915-m) mitigation zone; (2) the number of lookouts for a 1,000-yd
(915-m) mitigation zone would not change; (3)
[[Page 7015]]
the maximum net explosive weight would decrease from 29 lb (currently)
to 20 lb (proposed); (4) the Navy would continue to monitor the
mitigation zone for 30 minutes before, during, and 30 after the
activity to ensure that the area is clear of marine mammals; and (5)
time-delay firing device activities are only conducted during daylight
hours.
Vessels and In-Water Devices
Vessel Movement--Ships would avoid approaching marine mammals head
on and would maneuver to maintain a mitigation zone of 457 m around
observed whales, and 183 m around all other marine mammals (except bow
riding dolphins), providing it is safe to do so.
Towed In-water Devices--The Navy would ensure towed in-water
devices avoid coming within a mitigation zone of 229 m around any
observed marine mammal, providing it is safe to do so.
Non-Explosive Practice Munitions
Gunnery Exercises (small, medium, and large caliber using a surface
target)--Mitigation would include visual observation immediately before
and during the exercise within a mitigation zone of 183 m around the
intended impact location. The exercise would not commence if
concentrations of floating vegetation (Sargassum or kelp patties) are
observed in the mitigation zone. Firing would cease if a marine mammal
is visually detected within the mitigation zone. Firing would
recommence if any one of the following conditions are met: (1) The
animal is observed exiting the mitigation zone, (2) the animal is
thought to have exited the mitigation zone based on its course and
speed, (3) the mitigation zone has been clear from any additional
sightings for a period of 30 minutes, or (4) the intended target
location has been repositioned more than 366 m away from the location
of the last sighting.
Bombing Exercises--Mitigation would include visual observation from
the aircraft immediately before the exercise and during target approach
within a mitigation zone of 914 m around the intended impact location.
The exercise would not commence if concentrations of floating
vegetation (Sargassum or kelp patties) are observed in the mitigation
zone. Bombing would cease if a marine mammal is visually detected
within the mitigation zone. Bombing would recommence if any one of the
following conditions are met: (1) The animal is observed exiting the
mitigation zone, (2) the animal is thought to have exited the
mitigation zone based on its course and speed, or (3) the mitigation
zone has been clear from any additional sightings for a period of 30
minutes.
Other Mitigation
The Navy Marine Mammal Program utilizes the following standard
operating procedures to help to limit the low risk of disease
transmission from Navy marine mammals to indigenous marine mammals,
including the Hawaiian monk seals, while training in the HRC:
Waste from Navy sea lions would be collected and disposed
of in an approved sewer system;
During operations, all onsite personnel would be made
aware of the potential for disease transfer, and asked to report any
sightings of monk seals immediately to other training participants;
Sea lion handlers would visually scan for indigenous
marine animals, especially monk seals, for at least 5 minutes before a
Navy sea lion enters the water and would continue monitoring while the
sea lion is in the water. If a monk seal is seen approaching or within
100 m of the Navy sea lion, the handler would hold the Navy sea lion in
the boat or recall the Navy sea lion immediately if it has already been
released; and
The Navy would obtain an import permit from the State of
Hawaii Department of Agriculture and would adhere to the conditions of
that permit.
Humpback Whale Cautionary Area
The Navy is proposing to continue their designation of a humpback
whale cautionary area in Hawaiian waters. Humpback whales migrate to
the Hawaiian Islands each winter to rear their calves and mate. Data
indicate that, historically, humpback whales have concentrated in high
densities in certain areas around the Hawaiian Islands. NMFS has
reviewed the Navy's data on MFAS training in these dense humpback whale
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 MFAS 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 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 MFAS use have occurred. Coincident with
this use of MFAS, abundance estimates reflect an annual increase in the
humpback whale stock (Mobley 2001a, 2004). A recent long-term study of
humpback whales in Hawaiian waters shows long-term fidelity to the
Hawaiian winter grounds, with many showing sighting spans ranging from
10 to 32 years (Herman et al., 2011).
NMFS and the Navy have explored ways of effecting the least
practicable impact (which includes a consideration of practicality of
implementation and impacts to training fidelity) to humpback whales
from exposure to MFAS. Proficiency in ASW requires that Sailors gain
and maintain expert skills and experience in operating MFAS in myriad
marine environments. The Hawaiian Islands, including areas in which
humpback whales concentrate, contain unique bathymetric features the
Navy needs to ensure sailors gain critical skills and unique experience
by training in coastal waters. Sound propagates differently in shallow
water and no two shallow water areas are the same. So as not to
negatively affect military readiness, the Navy contends that it is
necessary to maintain the possibility of using all shallow water
training areas. Crew members will be working in similar areas during
real world events and these are the types of environments where enemy
submarines may be operating.
The Navy recognizes the significance of the Hawaiian Islands for
humpback whales. The Navy has designated a humpback whale cautionary
area, which consists of a 5-km (3.1-mi) buffer zone having one of the
highest concentrations of humpback whales during winter months. Similar
to the previous HRC rulemaking, conducting exercises in the humpback
whale cautionary area would continue to require a much higher level of
clearance than typically required for MFAS activities. Should national
security needs require MFAS training and testing in the humpback whale
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 MFAS 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 U.S.
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
[[Page 7016]]
stewardship. Further, CPF would provide specific direction on required
mitigation prior to operational units transiting to and training in the
humpback whale cautionary area. This process would ensure the decisions
to train in this area are made at the highest level in the Pacific
Fleet, heighten awareness of humpback whale activities in the
cautionary area, and serve to reemphasize that mitigation measures are
to be scrupulously followed. The Navy would provide NMFS with advance
notification of any MFAS training and testing activities in the
humpback whale cautionary area.
Data from several sources, which are summarized and cited on NOAA's
Cetacean and Sound Mapping Web site (cetsound.noaa.gov) indicate that
there are several resident populations of odontocetes off the western
side of the Big Island of Hawaii (e.g., beaked whales, melon-headed
whales, dwarf sperm whales, pilot whales). Generally, we highlight the
presence of resident populations in the interest of helping to support
decisions that ensure that these small populations, limited to a small
area of preferred habitat, are not exposed to concentrations of
activities within their ranges that have the potential to impact a
large portion of the stock/species over longer amounts of time that
could have detrimental consequences to the stock/species. However, NMFS
has reviewed the Navy's exercise reports and considered/discussed their
historical level of activity in the area where these resident
populations are concentrated, which is very low, and concluded that
time/area restrictions would not afford much reduction of impacts in
this location and are not necessary at this point. If future monitoring
and exercise reports suggest that increased operations overlap with
these resident populations, NMFS would revisit the consideration of
time/area limitations around these populations.
Cetacean and Sound Mapping
NMFS Office of Protected Resources standardly considers available
information about marine mammal habitat use to inform discussions with
applicants regarding potential spatio-temporal limitations of their
activities that might help effect the least practicable adverse impact
(e.g., Humpback Whale Cautionary Area). Through the Cetacean and Sound
Mapping effort (www.cetsound.noaa.gov), NOAA's Cetacean Density and
Distribution Mapping Working Group (CetMap) is currently involved in a
process to compile available literature and solicit expert review to
identify areas and times where species are known to concentrate for
specific behaviors (e.g., feeding, breeding/calving, or migration) or
be range-limited (e.g., small resident populations). These areas,
called Biologically Important Areas (BIAs), are useful tools for
planning and impact assessments and are being provided to the public
via the CetSound Web site, along with a summary of the supporting
information. While these BIAs are useful tools for analysts, any
decisions regarding protective measures based on these areas must go
through the normal MMPA evaluation process (or any other statutory
process that the BIAs are used to inform)--the designation of a BIA
does not pre-suppose any specific management decision associated with
those areas. Additionally, the BIA process is iterative and the areas
will be updated as new information becomes available. Currently, NMFS
has published BIAs for the Arctic Slope and some in Hawaii (which were
considered in the Mitigation Section for HSTT). The BIAs in other
regions, such as the Atlantic and West Coast of the continental U.S.
are still in development. We have indicated to the Navy that once these
BIAs are complete and put on the Web site, we may need to discuss
whether (in the context of the nature and scope of any Navy activities
planned in and around the BIAs, what impacts might be anticipated, and
practicability) additional protective measures might be appropriate.
Stranding Response Plan
NMFS and the Navy developed a Stranding Response Plan for the HRC
and SOCAL Range Complex in 2009 as part of the incidental take
authorization process. The Stranding Response Plans are specifically
intended to outline the applicable requirements the authorizations are
conditioned upon in the event that a marine mammal stranding is
reported in the HRC or SOCAL Range Complex during a major training
exercise. NMFS considers all plausible causes within the course of a
stranding investigation and these plans in no way presume that any
strandings in a Navy range complex are related to, or caused by, Navy
training and testing activities, absent a determination made during
investigation. The plans are designed to address mitigation,
monitoring, and compliance. The Navy is currently working with NMFS to
refine these plans for the new HSTT Study Area (to include regionally
specific plans that include more logistical detail). The current
Stranding Response Plans for the HRC and SOCAL Range Complex are
available for review here: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
Mitigation Conclusions
NMFS has carefully evaluated the Navy's proposed mitigation
measures and considered a broad range of other measures in the context
of ensuring that NMFS prescribes the means of effecting the least
practicable adverse impact on the affected marine mammal species and
stocks and their habitat. Our evaluation of potential measures included
consideration of the following factors in relation to one another: the
manner in which, and the degree to which, the successful implementation
of the measure is expected to minimize adverse impacts to marine
mammals; the proven or likely efficacy of the specific measure to
minimize adverse impacts as planned; and the practicability of the
measure for applicant implementation, including consideration of
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity.
In some cases, additional mitigation measures are required beyond
those that the applicant proposes. Any mitigation measure(s) prescribed
by NMFS should be able 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).
[[Page 7017]]
e. Avoidance or minimization of 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.).
Based on our evaluation of the Navy's proposed measures, as well as
other measures considered by NMFS or recommended by the public, NMFS
has determined preliminarily that the Navy's proposed mitigation
measures (especially when the adaptive management component is taken
into consideration (see Adaptive Management, below)) 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. Further
detail is included below.
The proposed rule comment period will afford the public an
opportunity to submit recommendations, views, and/or concerns regarding
this action and the proposed mitigation measures. While NMFS has
determined preliminarily that the Navy's proposed mitigation measures
would affect the least practicable adverse impact on the affected
species or stocks and their habitat, NMFS will consider all public
comments to help inform our final decision. Consequently, the proposed
mitigation measures may be refined, modified, removed, or added to
prior to the issuance of the final rule based on public comments
received, and where appropriate, further analysis of any additional
mitigation measures.
Monitoring
Section 101(a)(5)(A) of the MMPA states that in order to issue an
ITA for an activity, NMFS must set forth ``requirements pertaining to
the monitoring and reporting of such taking''. The MMPA implementing
regulations at 50 CFR 216.104 (a)(13) indicate that requests for 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:
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
An increase in our understanding of how many marine
mammals are likely to be exposed to levels of MFAS/HFAS (or explosives
or other stimuli) that we associate with specific adverse effects, such
as behavioral harassment, TTS, or PTS.
An increase in our understanding of how marine mammals
respond to MFAS/HFAS (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:
[cir] Behavioral observations in the presence of MFAS/HFAS 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)
[cir] Physiological measurements in the presence of MFAS/HFAS
compared to observations in the absence of tactical sonar (need to be
able to accurately predict received level and report bathymetric
conditions, distance from source, and other pertinent information)
[cir] Pre-planned and thorough investigation of stranding events
that occur coincident to naval activities
[cir] Distribution and/or abundance comparisons in times or areas
with concentrated MFAS/HFAS versus times or areas without MFAS/HFAS
An increased knowledge of the affected species
An increase in our understanding of the effectiveness of
certain mitigation and monitoring measures.
Overview of Navy Monitoring
The current Navy Fleet monitoring program is composed of a
collection of ``range-specific'' monitoring plans, each developed
individually as part of the MMPA/ESA authorization processes. These
individual plans establish specific monitoring requirements for each
range complex based on a set of effort-based metrics (e.g., 20 days of
aerial survey). Concurrent with implementation of the initial range-
specific monitoring plans, the Navy and NMFS began development of the
Integrated Comprehensive Monitoring Program (ICMP). The ICMP has been
developed in direct response to Navy permitting requirements
established in various MMPA final rules, ESA consultations, Biological
Opinions, and applicable regulations. The ICMP is intended to
coordinate monitoring efforts across all regions and to allocate the
most appropriate level and type of effort for each range complex based
on a set of standardized objectives, and in acknowledgement of regional
expertise and resource availability. The ICMP is designed to be a
flexible, scalable, and adaptable through the adaptive management and
strategic planning processes to periodically assess progress and
reevaluate objectives. Although the ICMP does not specify actual
monitoring field work or projects, it does establish top-level goals
that have been developed in coordination with NMFS. As the ICMP is
implemented, detailed and specific studies will be developed which
support the Navy's top-level monitoring goals. In essence, the ICMP
directs that monitoring activities relating to the effects of Navy
training and testing activities on marine species should be designed to
accomplish one or more of the following top-level goals:
An increase in our understanding of the likely occurrence
of marine mammals and/or ESA-listed marine species in the vicinity of
the action (i.e., presence, abundance, distribution, and/or density of
species);
An increase in our understanding of the nature, scope, or
context of the likely exposure of marine mammals and/or ESA-listed
species to any of the potential stressor(s) associated with the action
(e.g., tonal and impulsive sound), through better understanding of one
or more of the following: (1) The action and the environment in which
it occurs (e.g., sound source characterization, propagation, and
ambient noise levels); (2) the affected species (e.g., life history or
dive patterns); (3) the likely co-occurrence of marine mammals and/or
ESA-listed marine species with the action (in whole or part) associated
with specific adverse effects, and/or; (4) the likely biological or
behavioral context of exposure to the stressor for the marine mammal
and/or ESA-listed marine species (e.g., age class of exposed animals or
known pupping, calving or feeding areas);
An increase in our understanding of how individual marine
mammals or ESA-listed marine species respond
[[Page 7018]]
(behaviorally or physiologically) to the specific stressors associated
with the action (in specific contexts, where possible, e.g., at what
distance or received level);
An increase in our understanding of how anticipated
individual responses, to individual stressors or anticipated
combinations of stressors, may impact either: (1) the long-term fitness
and survival of an individual; or (2) the population, species, or stock
(e.g., through effects on annual rates of recruitment or survival);
An increase in our understanding of the effectiveness of
mitigation and monitoring measures;
A better understanding and record of the manner in which
the authorized entity complies with the ITA and Incidental Take
Statement;
An increase in the probability of detecting marine mammals
(through improved technology or methods), both specifically within the
safety zone (thus allowing for more effective implementation of the
mitigation) and in general, to better achieve the above goals; and
A reduction in the adverse impact of activities to the
least practicable level, as defined in the MMPA.
While the ICMP only directly applies to monitoring activities under
applicable MMPA and ESA authorizations, it also serves to facilitate
coordination among the Navy's marine species monitoring program and the
basic and applied research programs discussed in the Ongoing Navy-
funded Research section of this document.
An October 2010 Navy monitoring meeting initiated a process to
critically evaluate current Navy monitoring plans and begin development
of revisions to existing range-specific monitoring plans and associated
updates to the ICMP. Discussions at that meeting and through the Navy/
NMFS adaptive management process established a way ahead for continued
refinement of the Navy's monitoring program. This process included
establishing a Scientific Advisory Group (SAG) composed of technical
experts to provide objective scientific guidance for Navy
consideration. The Navy established the SAG in early 2011 with the
initial task of evaluating current Navy monitoring approaches under the
ICMP and existing LOAs and developing objective scientific
recommendations that would serve as the basis for a Strategic Planning
Process for Navy monitoring to be incorporated as a major component of
the ICMP. The SAG convened in March 2011, composed of leading academic
and civilian scientists with significant expertise in marine species
monitoring, acoustics, ecology, and modeling. The SAG's final report
laid out both over-arching and range-specific recommendations for the
Navy's Marine Species Monitoring program and is available through the
Navy's Marine Species Monitoring web portal: http://www.navymarinespeciesmonitoring.us.
Adaptive management discussions between the Navy and NMFS
established a way ahead for continued refinement of the Navy's
monitoring program. Consensus was that the ICMP and associated
implementation components would continue the evolution of Navy marine
species monitoring towards a single integrated program, incorporate SAG
recommendations when appropriate and logistically feasible, and
establish a more collaborative framework for evaluating, selecting, and
implementing future monitoring across all the Navy range complexes
through the adaptive management and strategic planning process.
Past and Current Monitoring in the HSTT Study Area
NMFS has received multiple years' worth of annual exercise and
monitoring reports addressing active sonar use and explosive
detonations within the HRC, SOCAL Range Complex, and SSTC. The data and
information contained in these reports have been considered in
developing mitigation and monitoring measures for the proposed training
and testing activities within the HSTT Study Area. The Navy's annual
exercise and monitoring reports may be viewed at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications and http://www.navymarinespeciesmonitoring.us. NMFS has reviewed these reports and
summarized the results, as related to marine mammal monitoring, below.
1. The Navy has shown significant initiative in developing its
marine species monitoring program and made considerable progress toward
reaching goals and objectives of the ICMP.
2. Observation data from watchstanders aboard navy vessels is
generally useful to indicate the presence or absence of marine mammals
within the mitigation zones (and sometimes beyond) and to document the
implementation of mitigation measures, but does not provide useful
species-specific information or behavioral data.
3. Data gathered by experienced marine mammal observers can provide
very valuable information at a level of detail not possible with
watchstanders.
4. Though it is by no means conclusive, it is worth noting that no
instances of obvious behavioral disturbance have been observed by Navy
watchstanders or experienced marine mammal observers conducting visual
monitoring.
5. Visual surveys generally provide suitable data for addressing
questions of distribution and abundance of marine mammals, but are much
less effective at providing information on movements and behavior, with
a few notable exceptions where sightings are most frequent. For
example, Navy-funded focal follows of marine mammals during aerial
visual surveys in SOCAL have provided unique new science on regional
at-sea marine mammal behavior including group size, travel direction,
spatial occurrence within SOCAL, maximum inter-animal dispersal, and
behavioral state.
6. Passive acoustics and animal tagging have significant potential
for applications addressing animal movements and behavioral response to
Navy training activities, but require a longer time horizon and heavy
investment in analysis to produce relevant results.
7. NMFS and the Navy should more carefully consider what and how
information should be gathered by watchstanders during training
exercises and monitoring events, as some reports contain different
information, making cross-report comparisons difficult.
Navy-funded monitoring accomplishments in the HRC and SOCAL
portions of HSTT from 2009 to 2012 are provided in the Navy's draft 5-
year Comprehensive Report, as required by the 2009 rulemakings and
available here: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. Following is a summary of the work
conducted:
Conducted over 4,000 hours of visual survey effort;
Covered over 64,800 nautical miles of ocean;
Sighted over 256,000 individual marine mammals;
Taken over 45,500 digital photos and 32 hours of digital
video;
Attached 70 satellite tracking tags to individual marine
mammals; and
Collected over 25,000 hours of passive acoustic
recordings.
Some recent highlights of findings include:
Increased understanding of Hawaiian monk seal habitat use
and behavior throughout the Main Hawaiian Islands;
Estimated received levels and reconstructions of animal
movements during an ASW training event from the bottom-mounted
hydrophone arrays at the Pacific Missile Range Facility;
[[Page 7019]]
Increased knowledge of baseline marine mammal behavior
information in SOCAL from focal follows of priority cetacean species;
and
Observed northern right whale dolphin mother-calf pairs
for the first time since SOCAL aerial monitoring surveys began in fall
2008.
Data collection and analysis within these range complexes is
ongoing. From 2009 to 2011, Navy lookouts aboard Navy ships reported
1,262 sightings for an estimated 12,875 marine mammals within the HSTT
Study Area. These observations were mainly during major at-sea training
events and there were no reported observations of adverse reactions by
marine mammals and no dead or injured animals reported associated with
Navy training activities.
Proposed Monitoring for the HSTT Study Area
Based on discussions between the Navy and NMFS, future monitoring
would address the ICMP top-level goals through a collection of specific
regional and ocean basin studies based on scientific objectives.
Quantitative metrics of monitoring effort (e.g., 20 days of aerial
survey) would not be a specific requirement. The adaptive management
process and reporting requirements would serve as the basis for
evaluating performance and compliance, primarily considering the
quality of the work and results produced, as well as peer review and
publications, and public dissemination of information, reports, and
data. The strategic planning process would be used to set intermediate
scientific objectives, identify potential species of interest at a
regional scale, and evaluate and select specific monitoring projects to
fund or continue supporting for a given fiscal year. The strategic
planning process would also address relative investments to different
range complexes based on goals across all range complexes, and
monitoring would leverage multiple techniques for data acquisition and
analysis whenever possible.
Ongoing Navy Research
Overview
The Navy is one of the world's leading organizations in assessing
the effects of human activities on the marine environment, and provides
a significant amount of funding and support to marine research, outside
of the monitoring required by their incidental take authorizations.
They also develop approaches to ensure that these resources are
minimally impacted by current and future Navy operations. Navy
scientists work cooperatively with other government researchers and
scientists, universities, industry, and non-governmental conservation
organizations in collecting, evaluating, and modeling information on
marine resources, including working towards a better understanding of
marine mammals and sound. From 2004 to 2012, the Navy has provided over
$230 million for marine species research. The Navy sponsors 70 percent
of all U.S. research concerning the effects of human-generated sound on
marine mammals and 50 percent of such research conducted worldwide.
Major topics of Navy-supported marine species research directly
applicable to proposed activities within the HSTT Study Area include
the following:
Better understanding of marine species distribution and
important habitat areas;
Developing methods to detect and monitor marine species
before and during training and testing activities;
Better understanding the impacts of sound on marine
mammals, sea turtles, fish, and birds; and
Developing tools to model and estimate potential impacts
of sound.
It is imperative that the Navy's research and development (R&D)
efforts related to marine mammals are conducted in an open, transparent
manner with validated study needs and requirements. The goal of the
Navy's R&D program is to enable collection and publication of
scientifically valid research as well as development of techniques and
tools for Navy, academic, and commercial use. The two Navy
organizations that account for most funding and oversight of the Navy
marine mammal research program are the Office of Naval Research (ONR)
Marine Mammals and Biology Program, and the Office of the Chief of
Naval Operations (CNO) Energy and Environmental Readiness Division
(N45) Living Marine Resources (LMR) Program. The primary focus of these
programs has been on understanding the effects of sound on marine
mammals, including physiological, behavioral and ecological effects.
The ONR Marine Mammals and Biology Program supports basic and
applied research and technology development related to understanding
the effects of sound on marine mammals, including physiological,
behavioral, ecological, and population-level effects. Current program
thrusts include, but are not limited to:
Monitoring and detection;
Integrated ecosystem research including sensor and tag
development;
Effects of sound on marine life including hearing,
behavioral response studies, diving and stress physiology, and
Population Consequences of Acoustic Disturbance (PCAD); and
Models and databases for environmental compliance.
To manage some of the Navy's marine mammal research programmatic
elements, OPNAV N45 developed in 2011 a new Living Marine Resources
(LMR) Research and Development Program. The mission of the LMR program
is to develop, demonstrate, and assess information and technology
solutions to protect living marine resources by minimizing the
environmental risks of Navy at-sea training and testing activities
while preserving core Navy readiness capabilities. This mission is
accomplished by:
Improving knowledge of the status and trends of marine
species of concern and the ecosystems of which they are a part;
Developing the scientific basis for the criteria and
thresholds to measure the effects of Navy generated sound;
Improving understanding of underwater sound and sound
field characterization unique to assessing the biological consequences
resulting from underwater sound (as opposed to tactical applications of
underwater sound or propagation loss modeling for military
communications or tactical applications); and
Developing technologies and methods to monitor and, where
possible, mitigate biologically significant consequences to living
marine resources resulting from naval activities, emphasizing those
consequences that are most likely to be biologically significant.
The program is focused on three primary objectives that influence
program management priorities and directly affect the program's success
in accomplishing its mission:
1. Collect, Validate, and Rank R&D Needs: Expand awareness of R&D
program opportunities within the Navy marine resource community to
encourage and facilitate the submittal of well-defined and appropriate
needs statements.
2. Address High Priority Needs: Ensure that program investments and
the resulting projects maintain a direct and consistent link to the
defined user needs.
3. Transition Solutions and Validate Benefits: Maximize the number
of program-derived solutions that are successfully transitioned to the
Fleet and system commands.
[[Page 7020]]
The LMR program primarily invests in the following areas:
Developing Data to Support Risk Threshold Criteria;
Improved Data Collection on Protected Species, Critical
Habitat within Navy Ranges;
New Monitoring and Mitigation Technology Demonstrations;
Database and Model Development; and
Education and Outreach, Emergent Opportunities.
The Navy has also developed the technical reports and supporting
data used for analysis in the HSTT DEIS/OEIS and this proposed rule,
which include the Navy Marine Species Density Database, Acoustic
Criteria and Thresholds, and Determination of Acoustic Effects on
Marine Mammals and Sea Turtles. Furthermore, research cruises by NMFS
and by academic institutions have received funding from the Navy. For
instance, LMR currently supports the Marine Mammal Monitoring on Ranges
program at Pacific Missile Range Facility on Kauai and, along with ONR,
the multi-year Southern California Behavioral Response Study (http://www.socal-brs.org). All of this research helps in understanding the
marine environment and the effects that may arise from underwater noise
in oceans. 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 Research and Development
Navy Funded--Both OPNAV N45 and ONR R&D programs have projects
ongoing within the HSTT Study Area. Some data and results from these
R&D projects are summarized in the Navy's annual range complex
monitoring reports, and available on NMFS' Web site (http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications) and the
Fleet's new marine species monitoring Web site (http://www.navymarinespeciesmonitoring.us). In addition, the Navy's Fleet
monitoring is coordinated with R&D monitoring in a given region to
leverage research objectives, assets, and studies where possible under
the Navy's Integrated Comprehensive Monitoring Program.
Below are some current Navy R&D funded projects or joint Navy-NMFS/
academic funded projects through 2012 in the HSTT Study Area. Southern
California:
Behavioral Response Study (multiple academic, NMFS,
contract scientists, Navy science organizations, and other
collaborators; $1.8M funded by OPNAV N45 and ONR)
Small Boat Based Marine Mammal Surveys in Southern
California (Scripps Institute of Oceanography, University of California
San Diego; $400K funded by OPNAV N45)
Distribution and Demographics of Marine Mammals in SOCAL
Through Photo-Identification, Genetics, and Satellite Telemetry
(Cascadia Research Collective; $260K funded by OPNAV N45)
Blue and Humpback Acoustic Survey Methods (Southwest
Fisheries Science Center, National Marine Fisheries Service Fisheries
Science Center, $160K funded by OPNAV N45)
Tracking Marine Mammals on Southern California Offshore
ASW Range (SOAR) using Marine Mammal Monitoring on Navy Ranges (M3R)
(Naval Undersea Warfare Center Newport; $500K funded by OPNAV N45)
Hawaii:
Passive Acoustic Methods for Tracking Marine Mammals Using
Widely-Spaced Bottom Mounted Hydrophones (University of Hawaii; funded
by ONR)
Satellite Tagging Odontocetes in the Navy's Pacific
Missile Range Facility (PMRF) and Kauai (Cascadia Research Collective;
$150K funded by OPNAV N45)
Tracking Marine Mammals on PMRF using Marine Mammal
Monitoring on Navy Ranges (M3R) System (Naval Undersea Warfare Center
Newport; $290K funded by OPNAV N45)
Remote Monitoring of Dolphins and Whales in the High Naval
Activity Areas in Hawaiian Waters (Hawaii Institute of Marine Biology,
funded by ONR)
The integration between the Navy's new LMR R&D program and related
fleet and Systems Command HSTT monitoring would continue and improve
over the 5-year period with applicable R&D results presented in HSTT
annual monitoring reports.
Other National Department of Defense Funded Initiatives--The
Strategic Environmental Research and Development Program (SERDP) and
Environmental Security Technology Certification Program (ESTCP) are the
Department of Defense's environmental research programs, harnessing the
latest science and technology to improve environmental performance,
reduce costs, and enhance and sustain mission capabilities. The
programs respond to environmental technology requirements common to all
military services, complementing the services' research programs. SERDP
and ESTCP promote partnerships and collaboration among academia,
industry, the military services, and other federal agencies. They are
independent programs managed from a joint office to coordinate the full
spectrum of efforts, from basic and applied research to field
demonstration and validation. Beginning in March 2012, an ESTCP project
that might eventually be applicable to future Navy training and testing
is the Biodegradable Sonobuoy Decelerators. More information about this
project can be found at: http://www.serdp.org/Program-Areas/Weapons-Systems-and-Platforms/Waste-Reduction-and-Treatment-in-DoD-Operations/WP-201222/WP-201222/(language)/eng-US).
Adaptive Management
The final regulations governing the take of marine mammals
incidental to Navy training and testing activities in the HSTT Study
Area would contain an adaptive management component carried over from
previous authorizations. Although better than 5 years ago, our
understanding of the effects of Navy training and testing activities
(e.g., MFAS/HFAS, underwater detonations) on marine mammals is still
relatively limited, 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.
The reporting requirements associated with this proposed rule are
designed to provide NMFS with monitoring data from the previous year to
allow NMFS to consider whether any changes are appropriate. NMFS and
the Navy would meet to discuss the monitoring reports, Navy R&D
developments, and current science and whether mitigation or monitoring
modifications are appropriate. The use of adaptive management allows
NMFS to consider new information from different sources to determine
(with input from the Navy regarding practicability) on an annual or
biennial basis if mitigation or monitoring measures should be modified
(including additions or deletions). Mitigation measures could be
modified if new data suggests that such modifications would have a
reasonable likelihood of reducing adverse effects to marine mammals and
if the measures are practicable.
The following are some of the possible sources of applicable data
to be considered through the adaptive
[[Page 7021]]
management process: (1) Results from monitoring and exercises reports,
as required by MMPA authorizations; (2) compiled results of Navy funded
R&D studies; (3) results from specific stranding investigations; (4)
results from general marine mammal and sound research; and (5) any
information which reveals that marine mammals may have been taken in a
manner, extent, or number not authorized by these regulations or
subsequent LOAs.
The Navy is currently establishing a strategic planning process
under the ICMP in coordination with NMFS. The objective of the
strategic planning process is to guide the continued evolution of Navy
marine species monitoring towards a single integrated program,
incorporating expert review and recommendations, and establishing a
more structured and collaborative framework for evaluating, selecting,
and implementing future monitoring across the all Navy range complexes.
The Strategic Plan is intended to be a primary component of the ICMP
and provide a ``vision'' for navy monitoring across geographic
regions--serving as guidance for determining how to most efficiently
and effectively invest the marine species monitoring resources to
address ICMP top-level goals and satisfy MMPA monitoring requirements.
This process is being designed to integrate various elements including:
ICMP top-level goals;
SAG recommendations;
Integration of regional scientific expert input;
Ongoing adaptive management review dialogue between NMFS
and the Navy;
Lessons learned from past and future monitoring at Navy
training and testing ranges; and
Leveraged research and lessons learned from other Navy
funded marine science programs.
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 rulemaking may
contain additional details not contained here. Additionally, proposed
reporting requirements may be modified, removed, or added based on
information or comments received during the public comment period.
Reports from individual monitoring events, results of analyses,
publications, and periodic progress reports for specific monitoring
projects would be posted to the Navy's Marine Species Monitoring web
portal: http://www.navymarinespeciesmonitoring.us. Currently, there are
several different reporting requirements pursuant to these proposed
regulations:
General Notification of Injured or Dead Marine Mammals
Navy personnel would ensure that NMFS (the appropriate 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
would provide NMFS with species identification or a 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 photographs or video (if available). The HSTT
Stranding Response Plan contains further reporting requirements for
specific circumstances (http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications).
Annual Monitoring and Exercise Reports
As noted above, reports from individual monitoring events, results
of analyses, publications, and periodic progress reports for specific
monitoring projects would be posted to the Navy's Marine Species
Monitoring web portal as they become available. Progress and results
from all monitoring activity conducted within the HSTT Study Area, as
well as required Major Training Event exercise activity, would be
summarized in an annual report. A draft of this report would be
submitted to NMFS for review by April 15 of each year. NMFS would
review the report and provide comments for incorporation within 3
months.
Comprehensive Monitoring and Exercise Summary Report
The Navy would submit to NMFS a draft report that analyzes and
summarizes all of the multi-year marine mammal monitoring and Major
Training Event exercise information gathered during training and
testing exercises for which individual annual reports are required
under the proposed regulations. This report would be submitted at the
end of the fourth year of the rule (December 2018), covering activities
that have occurred through June 1, 2018. 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 provide comments.
Estimated Take of Marine Mammals
In the potential effects section, NMFS' analysis identified the
lethal responses, physical trauma, sensory impairment (PTS, TTS, 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 proposed training and
testing activities in the Study Area.
As mentioned previously, behavioral responses are context-
dependent, complex, and influenced to varying degrees by a number of
factors other than just received level. For example, an animal may
respond differently to a sound emanating from a ship that is moving
towards the animal than it would to an identical received level coming
from a vessel that is moving away, or to a ship traveling at a
different speed or at a different distance from the animal. At greater
distances, though, the nature of vessel movements could also
potentially not have any effect on the animal's response to the sound.
In any case, a full description of the suite of factors that elicited a
behavioral response would require a mention of the vicinity, speed and
movement of the vessel, or other factors. So, while sound sources and
the received levels are the primary focus of the analysis and those
that are laid out quantitatively in the regulatory text, it is with the
understanding that other factors related to the training are sometimes
contributing to the behavioral responses of marine mammals, although
they cannot be quantified.
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
[[Page 7022]]
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 earlier in this
document, the 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 non-impulsive or impulsive sound, is considered Level B Harassment.
Some of the lower level physiological stress responses discussed
earlier would 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.
Earlier in this document, 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 category.
Behavioral harassment does not generally 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.
Temporary Threshold Shift (TTS)--As discussed previously, TTS can
affect 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 sonar and other
active acoustic sources and explosives and other impulsive sources) as
Level B Harassment, not Level A Harassment (injury).
Level A Harassment
Of the potential effects that were described earlier, following are
the types of effects that fall into the Level A Harassment category:
Permanent Threshold Shift (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.
Tissue Damage due to Acoustically Mediated Bubble Growth--A few
theories suggest ways in which gas bubbles become enlarged through
exposure to intense sounds (MFAS/HFAS) to the point where tissue damage
results. In rectified diffusion, exposure to a sound field would cause
bubbles to increase in size. A short duration of sonar pings (such as
that which an animal exposed to MFAS would be most likely to encounter)
would not likely be long enough to drive bubble growth to any
substantial 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. The degree of
supersaturation and exposure levels observed to cause microbubble
destabilization are unlikely to occur, either alone or in concert
because of how close an animal would need to be to the sound source to
be exposed to high enough levels, especially considering the likely
avoidance of the sound source and the required mitigation. Still,
possible tissue damage from either of these processes would be
considered an injury.
Tissue Damage due to 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
(unusually rapid ascent, unusually long series of surface dives, etc.)
in a manner that might result in unusual bubble formation or growth
ultimately resulting in tissue damage. In this scenario, the rate of
ascent would need to be sufficiently rapid to compromise behavioral or
physiological protections against nitrogen bubble formation. There is
considerable disagreement among scientists as to the likelihood of this
phenomenon (Piantadosi and Thalmann, 2004; Evans and Miller, 2003).
Although it has been argued that traumas from recent beaked whale
strandings are consistent with gas emboli and bubble-induced tissue
separations (Jepson et al., 2003; Fernandez et al., 2005), nitrogen
bubble formation as the cause of the traumas has not been verified. If
tissue damage does occur by this phenomenon, it would be considered an
injury.
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.
Vessel or Ordnance Strike--Vessel strike or ordnance strike
associated with the specified activities would be considered Level A
Harassment, serious injury, or mortality.
Take Criteria
For the purposes of an MMPA 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
[[Page 7023]]
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 non-impulse and impulse sounds cannot
be easily detected or measured, 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 non-
impulse or impulse sounds) Level B Harassment and Level A Harassment of
marine mammals would occur. The acoustic criteria for non-impulse and
impulse sounds are discussed below.
Level B Harassment Threshold (TTS)--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 are likely to occur is 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). Alternately, TTS is a
physiological effect that has been studied and quantified in laboratory
conditions. Because data exist to support an estimate of the received
levels at which marine mammals will incur TTS, NMFS uses an acoustic
criteria to estimate the number of marine mammals that might sustain
TTS. TTS is a subset of Level B Harassment (along with sub-TTS
behavioral harassment) and we are not specifically required to estimate
those numbers; however, the more specifically we can estimate the
affected marine mammal responses, the better the analysis.
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 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 determined through
study of terrestrial mammals.
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)
does not exist. However, based on the number of years (more than 60)
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. Tables 13 and 14
provide a summary of non-impulsive thresholds to TTS and PTS for marine
mammals. A detailed explanation of how these thresholds were derived is
provided in the HSTT DEIS/OEIS Criteria and Thresholds Technical Report
(http://hstteis.com/DocumentsandReferences/HSTTDocuments/SupportingTechnicalDocuments.aspx) and summarized in Chapter 6 of the
Navy's LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications).
Table 13--Onset TTS and PTS Thresholds for Non-Impulse Sound
----------------------------------------------------------------------------------------------------------------
Group Species Onset TTS Onset PTS
----------------------------------------------------------------------------------------------------------------
Low-Frequency Cetaceans.............. All mysticetes......... 178 dB re 1[mu]Pa2- 198 dB re 1[mu]Pa2-
sec(LFII). sec(LFII).
Mid-Frequency Cetaceans.............. Most delphinids, beaked 178 dB re 1[mu]Pa2- 198 dB re 1[mu]Pa2-
whales, medium and sec(MFII). sec(MFII).
large toothed whales.
High-Frequency Cetaceans............. Porpoises, Kogia spp... 152 dB re 1[mu]Pa2- 172 dB re 1[mu]Pa2-
sec(HFII). secSEL (HFII).
Phocidae In-water.................... Harbor, Hawaiian monk, 183 dB re 1[mu]Pa2- 197 dB re 1[mu]Pa2-
elephant seals. sec(PWI). sec(PWI).
Otariidae & Obodenidae In-water...... Sea lions and fur seals 206 dB re 1[mu]Pa2- 220 dB re 1[mu]Pa2-
sec(OWI). sec(OWI).
Mustelidae In-water.................. Sea otters.
----------------------------------------------------------------------------------------------------------------
LFII, MFII, HFII: New compound Type II weighting functions; PWI, OWI: Original Type I (Southall et al. 2007) for
pinniped and mustelid in water.
Table 14--Impulsive Sound Explosive Criteria and Thresholds for Predicting Injury and Mortality
----------------------------------------------------------------------------------------------------------------
Slight injury
Group Species -------------------------------------------------- Mortality
PTS GI Tract Lung
----------------------------------------------------------------------------------------------------------------
Low-frequency Cetaceans...... All mysticetes.. 187 dB SEL 237 dB SPL or Equation 1.... Equation 2.
(LFII) or 230 104 psi.
dB Peak SPL.
Mid-frequency Cetaceans...... Most delphinids, 187 dB SEL
medium and (MFII) or 230
large toothed dB Peak SPL.
whales.
High-frequency Cetaceans..... Porpoises and 161 dB SEL
Kogia spp. (HFII) or 201
dB Peak SPL.
Phocidae..................... Hawaiian monk, 192 dB SEL (PWI)
elephant, and or 218 dB Peak
harbor seal. SPL.
Otariidae.................... Sea lions and 215 dB SEL (OWI)
fur seals. or 218 dB Peak
SPL.
Mustelidae................... Sea otters.
----------------------------------------------------------------------------------------------------------------
[[Page 7024]]
Equation 1:
= 39.1M1/3 (1+[DRm/10.081]) 1/2 Pa-sec
Equation 2:
= 91.4M1/3 (1+[DRm/10.081])1/2 Pa-sec
Where: M = mass of the animals in kg.
DRm = depth of the receiver (animal) in meters.
Level B Harassment Risk Function (Behavioral Harassment)--In 2006,
NMFS issued the first MMPA authorization to allow the take of marine
mammals incidental to MFAS (to the Navy for RIMPAC). For that
authorization, NMFS used 173 dB 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 db SEL
would be predicted to be taken by Level B Harassment and all animals
exposed to less than 173 dB 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'' or ``dose-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 1a). In January 2009,
NMFS issued three final rules governing the incidental take of marine
mammals (within Navy's HRC, SOCAL, and Atlantic Fleet Active Sonar
Training (AFAST)) that used a risk continuum to estimate the percent of
marine mammals exposed to various levels of MFAS that would respond in
a manner NMFS considers harassment.
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 earlier, factors other
than received level (such as distance from or bearing to the sound
source, context of animal at time of exposure) 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 become available and can
be appropriately and effectively incorporated.
The particular acoustic risk functions developed by NMFS and the
Navy (see Figures 1a and 1b) 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 MFAS/HFAS. 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 the Navy's SURTASS LFA MMPA
authorization as well.
[GRAPHIC] [TIFF OMITTED] TP31JA13.001
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 and
pinnipeds) or 8 (mysticetes).
Detailed information on the above equation and its parameters is
available in the HSTT DEIS/OEIS and previous Navy documents listed
above.
The inclusion of a special behavioral response criterion for beaked
whales of the family Ziphiidae is new to these criteria. It has been
speculated that beaked whales might have unusual sensitivities to sonar
sound due to their likelihood of stranding in conjunction with MFAS
use, even in areas where other species were more abundant (D'Amico et
al. 2009), but there were not sufficient data to support a separate
treatment for beaked whales until recently. With the recent publication
of results from Blainville's beaked whale monitoring and experimental
exposure studies on the instrumented Atlantic Undersea Test and
Evaluation Center range in the Bahamas (McCarthy et al. 2011; Tyack et
al. 2011), there are now statistically strong data suggesting that
beaked whales tend to avoid both actual naval MFAS in real anti-
submarine training scenarios as well as sonar-like signals and other
signals used during controlled sound exposure studies in the same area.
An unweighted 140 dB re 1 [mu]Pa sound pressure level threshold has
been adopted by the Navy for significant behavioral effects for all
beaked whales (family: Ziphiidae).
If more than one explosive event occurs within any given 24-hour
period within a training or testing event, behavioral criteria are
applied to predict the number of animals that may be taken by Level B
Harassment. For multiple explosive events the behavioral threshold used
in this analysis is 5 dB less than the TTS onset threshold (in sound
exposure level). This value is derived from observed onsets of
behavioral response by test subjects (bottlenose dolphins) during non-
impulse TTS testing (Schlundt et al. 2000). Some multiple explosive
events, such as certain naval gunnery exercises, may be treated as a
single impulsive event because a few explosions occur closely spaced
within a very short period of time (a few seconds). For single impulses
at received sound levels below hearing loss thresholds, the most likely
behavioral response is a brief alerting or orienting response. Since no
further sounds follow the initial brief impulses, Level B take in the
form of behavioral harassment beyond that associated with potential TTS
would not be expected to occur. Explosive criteria and thresholds are
summarized in Table 15 and further detailed in the Navy's LOA
application.
Since impulse events can be quite short, it may be possible to
accumulate multiple received impulses at sound pressure levels
considerably above the energy-based criterion and still not be
considered a behavioral take. The Navy treats all individual received
impulses as if they were one second long for the purposes of
calculating cumulative sound exposure level for multiple impulse
events. For example, five air gun impulses, each 0.1 second long,
received at 178 dB sound pressure level would equal a 175 dB sound
exposure level, and would not be predicted as leading to a take.
However, if the five 0.1 second pulses are treated as a 5 second
exposure, it would yield an adjusted value of approximately 180 dB,
exceeding the threshold. For impulses
[[Page 7025]]
associated with explosions that have durations of a few microseconds,
this assumption greatly overestimates effects based on sound exposure
level metrics such as TTS and PTS and behavioral responses. Appropriate
weighting values will be applied to the received impulse in one-third
octave bands and the energy summed to produce a total weighted sound
exposure level value. For impulsive behavioral criteria, the Navy's new
weighting functions (detailed in the LOA application) are applied to
the received sound level before being compared to the threshold.
Table 15-- Explosive Criteria and Thresholds
--------------------------------------------------------------------------------------------------------------------------------------------------------
Slight injury
Group Species ------------------------------------------------------------------------ Mortality
PTS GI Tract Lung
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low Frequency Cetaceans.......... All mysticetes...... 187 dB SEL (LFII) or 237 dB SPL or 104 psi.. Equation 1............. Equation 2.
230 dB Peak SPL.
Mid-Frequency Cetaceans.......... Most delphinids, 187 dB SEL (MFII) or
medium and large 230 dB Peak SPL.
toothed whales.
High Frequency Cetaceans......... Porpoises and Kogia 161 dB SEL (HFII) or
spp. 201dB Peak SPL.
Phocidae......................... Hawaiian monk, 192 dB SEL (PWI) or
elephant, and 218 dB Peak SPL.
harbor seal.
Otariidae........................ Sea lions and Fur 215 dB SEL (OWI) or
seals. 218 dB Peak SPL.
Mustelidae....................... Sea Otters.
--------------------------------------------------------------------------------------------------------------------------------------------------------
[GRAPHIC] [TIFF OMITTED] TP31JA13.002
Existing NMFS criteria was applied to sounds generated by pile
driving and airguns (Table 16).
Table 16--Thresholds for Pile Driving and Airguns
----------------------------------------------------------------------------------------------------------------
Underwater vibratory pile driving Underwater impact pile driving and
criteria (sound pressure level, dB re airgun criteria (sound pressure level,
1 [mu]Pa) dB re 1 [mu]Pa)
Species groups -------------------------------------------------------------------------------
Level B Level B
Level A injury disturbance Level A injury disturbance
threshold threshold threshold threshold
----------------------------------------------------------------------------------------------------------------
Cetaceans (whales, dolphins, 180 dB rms........ 120 dB rms........ 180 dB rms........ 160 dB rms.
porpoises).
Pinnipeds (seals)............... 190 dB rms........ 120 dB rms........ 190 dB rms........ 160 dB rms.
----------------------------------------------------------------------------------------------------------------
Quantitative Modeling for Impulsive and Non-Impulsive Sound
The Navy performed a quantitative analysis to estimate the number
of marine mammals that could be harassed by acoustic sources or
explosives used during Navy training and testing activities. Inputs to
the quantitative analysis included marine mammal density estimates;
marine mammal depth occurrence distributions; oceanographic and
environmental data; marine mammal hearing data; and criteria and
thresholds for levels of potential effects. The quantitative analysis
consists of computer-modeled estimates and a post-model analysis to
determine the number of potential mortalities and harassments. The
model calculates sound energy propagation from sonars, other active
acoustic sources, and explosives during naval activities; the sound or
impulse received by animat dosimeters representing marine mammals
distributed in the area around the modeled activity; and whether the
sound or impulse received by a marine mammal exceeds the thresholds for
effects. The model estimates are then further analyzed to consider
animal avoidance and implementation of mitigation measures, resulting
in final estimates of effects due to Navy training and testing. This
process results in a reduction to take numbers and is detailed in
Chapter 6 (section 6.3) of the Navy's application.
A number of computer models and mathematical equations can be used
to predict how energy spreads from a sound source (e.g., sonar or
underwater detonation) to a receiver (e.g., dolphin or sea turtle).
Basic underwater sound models calculate the overlap of energy and
marine life using assumptions that account for the many, variable, and
often unknown factors that can greatly influence the result.
Assumptions in previous Navy models have intentionally erred on the
side of overestimation when there are unknowns or when the addition of
other variables was not likely to substantively change the final
analysis. For example, because the ocean environment is extremely
dynamic and information is often limited to a synthesis of data
gathered over wide areas and requiring many years of research, known
information tends to be an average of a seasonal or annual variation.
The Equatorial Pacific El Nino disruption of the ocean-atmosphere
system is an example of dynamic change where unusually warm ocean
temperatures are likely to redistribute marine life and alter the
propagation of underwater sound energy. Previous Navy modeling
therefore made some assumptions
[[Page 7026]]
indicative of a maximum theoretical propagation for sound energy (such
as a perfectly reflective ocean surface and a flat seafloor). More
complex computer models build upon basic modeling by factoring in
additional variables in an effort to be more accurate by accounting for
such things as bathymetry and an animal's likely presence at various
depths.
The Navy has developed a set of data and new software tools for
quantification of estimated marine mammal impacts from Navy activities.
This new approach is the resulting evolution of the basic model
previously used by the Navy and reflects a more complex modeling
approach as described below. Although this more complex computer
modeling approach accounts for various environmental factors affecting
acoustic propagation, the current software tools do not consider the
likelihood that a marine mammal would attempt to avoid repeated
exposures to a sound or avoid an area of intense activity where a
training or testing event may be focused. Additionally, the software
tools do not consider the implementation of mitigation (e.g., stopping
sonar transmissions when a marine mammal is within a certain distance
of a ship or range clearance prior to detonations). In both of these
situations, naval activities are modeled as though an activity would
occur regardless of proximity to marine mammals and without any
horizontal movement by the animal away from the sound source or human
activities (e.g., without accounting for likely animal avoidance).
Therefore, the final step of the quantitative analysis of acoustic
effects is to consider the implementation of mitigation and the
possibility that marine mammals would avoid continued or repeated sound
exposures.
The quantified results of the marine mammal acoustic effects
analysis presented in the Navy's LOA application differ from the
quantified results presented in the HSTT DEIS/OEIS. Presentation of the
results in this new manner for MMPA, ESA, and other regulatory analyses
is well within the framework of the previous NEPA analyses presented in
the DEIS. The differences are due to three main factors: (1)
Administrative corrections to the modeling inputs for training and
testing; (2) use of a more accurate seasonal density for the species
(short-beaked common dolphins) having the highest abundance of any
marine mammal in the Study Area; and (3) additional post-model
quantification to further refine the numerical analysis of acoustic
effects so as to include animal avoidance of sound sources, avoidance
of areas of activity before use of a sound source or explosive, and
implementation of mitigation. This additional quantification was in
direct response to public comments received on the HSTT DEIS/OEIS with
regard to a somewhat universal misunderstanding of the numbers
presented as modeling results. These comments indicated that many
readers believed the modeling effects numbers presented in the tables
were the entire acoustic impact analysis. Furthermore, it was clear
that these same readers had missed the critical subsequent qualitative
analysis required to accurately interpret those numbers since the model
does not account for animal avoidance of repeated explosive exposures,
movement, or standard Navy mitigations. In response to these comments,
the numbers presented in Navy's LOA application will be reflected in
the HSTT FEIS/OEIS to more fully quantify the analyzed effects to
marine mammals. The differences between the HSTT DEIS/OEIS and the
Navy's LOA application reflect reductions in the analyzed mortality
takes, Level A takes, and Level B takes. The Navy has advised NMFS that
all comments received on the proposed rule that address (1)
Administrative corrections to the modeling inputs for training and
testing; (2) use of more accurate seasonal density data; and (3) post-
model quantification based on animal avoidance of sound sources and
mitigation will be reviewed and addressed by the Navy in the HSTT FEIS/
OEIS.
The steps of the quantitative analysis of acoustic effects, the
values that went into the Navy's model, and the resulting ranges to
effects are detailed in Chapter 6 of the Navy's LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications).
Take Request
The HSTT DEIS/OEIS considered all training and testing activities
proposed to occur in the Study Area that have the potential to result
in the MMPA defined take of marine mammals. The stressors associated
with these activities included the following:
Acoustic (sonar and other active non-impulse sources,
explosives, pile driving, swimmer defense airguns, weapons firing,
launch and impact noise, vessel noise, aircraft noise);
Energy (electromagnetic devices);
Physical disturbance or strikes (vessels, in-water
devices, military expended materials, seafloor devices);
Entanglement (fiber optic cables, guidance wires,
parachutes);
Ingestion (munitions, military expended materials other
than munitions); and
Indirect stressors (risk to monk seals from Navy
California sea lions from the transmission of disease or parasites).
The Navy determined, and NMFS agrees, that three stressors could
potentially result in the incidental taking of marine mammals from
training and testing activities within the Study Area: (1) Non-
impulsive stressors (sonar and other active acoustic sources), (2)
impulsive stressors (explosives, pile driving and removal), and (3)
vessel strikes. Non-impulsive and impulsive stressors have the
potential to result in incidental takes of marine mammals by
harassment, injury, or mortality. Vessel strikes have the potential to
result in incidental take from direct injury and/or mortality.
Training Activities--Based on the Navy's model and post-model
analysis (described in detail in Chapter 6 of their LOA application),
Table 18 summarizes the Navy's take request for training activities for
an annual maximum year (a notional 12-month period when all annual and
non-annual events could occur) and the summation over a 5-year period
(annual events occurring five times and non-annual events occurring
three times). Table 19 summarizes the Navy's take request for training
activities by species from the modeling estimates.
While the Navy does not anticipate any marine mammal strandings or
that the mortalities predicted by the acoustic modeling would occur,
the Navy requests annual authorization for take by mortality of up to
seven small odontocetes (i.e., dolphins) and pinnipeds to include any
combination of such species that may be present in the Study Area.
While the Navy does not anticipate any beaked whale strandings or
mortalities from sonar and other active sources, in order to account
for unforeseen circumstances that could lead to such effects the Navy
requests the annual take, by mortality, of two beaked whales as part of
training activities.
Vessel strike to marine mammals is not associated with any specific
training activity but rather a limited, sporadic, and accidental result
of Navy vessel movement within the Study Area. In order to account for
the accidental nature of vessel strikes to large whales in general, and
the potential risk from any vessel movement within the Study Area, the
Navy is seeking take authorization in the event a Navy vessel strike
does occur while conducting training. The Navy's take authorization
[[Page 7027]]
request is based on the probabilities of whale strikes suggested by the
data from NMFS Southwest Regional Office, NMFS Pacific Islands Regional
Office, the Navy, and the calculations detailed in Chapter 6 of the
Navy's LOA application. The number of Navy and commercial whale strikes
for which the species has been positively identified suggests that the
probability of striking a gray whale in the SOCAL Range Complex and
humpback whale in the HRC is greater than striking other species.
However, since species identification has not been possible in most
vessel strike cases, the Navy cannot quantifiably predict what species
may be taken. Therefore, the Navy seeks take authorization by vessel
strike for any combined number of large whale species to include gray
whale, fin whale, blue whale, humpback whale, Bryde's whale, sei whale,
minke whale, or sperm whale. The Navy requests takes of large marine
mammals over the course of the 5-year regulations from training
activities as discussed below:
The take by vessel strike during training activities in
any given year of no more than four large whales total of any
combination of species including gray whale, fin whale, blue whale,
humpback whale, Bryde's whale, sei whale, minke whale, or sperm whale.
The four takes per year requested would be no more than two of any one
species of blue whale, fin whale, humpback whale, sei whale, or sperm
whale in any given year.
The take by vessel strike of no more than 12 large whales
from training activities over the course of the five years of the HSTT
regulations.
Over a period of 20 years from 1991 to 2010 there have been a total
of 16 Navy vessel strikes in SOCAL, and five Navy vessel strikes in
HRC. It should be noted that two of the five HRC Navy strikes were by
<12-meter workboats vice larger Navy ships. In terms of the 16
consecutive 5-year periods in the last 20 years, no single 5-year
period exceeded ten whales struck within SOCAL and HRC (periods from
2000-2004 and 2001-2005). For Navy vessel strikes in SOCAL, there were
six consecutive 5-year periods with six or more whales struck (1997-
2001, 1998-2002, 1999-2003, 2000-2004, 2001-2005, and 2002-2006), and
no more than three whales struck in the last 5-year period from 2006-
2010. No whales have been struck by Navy vessels in SOCAL since 2009.
For Navy vessel strikes in the HRC for the same time period, there was
one 5-year period when three whales were struck (2003-2007), seven
periods when two whales were struck, five periods when one whale was
struck, and three periods when no whales were struck. Within the data
set analyzed for HRC through 2010, no whales have been struck by a Navy
vessel since 2008. Also as discussed in Chapter 6 of the Navy's LOA
application, the Poisson probability of striking as many as two large
whales in the SOCAL portion of the HSTT is only 14 percent per year,
and the probability of striking two large whales in the HRC portion of
the HSTT is only 2 percent.
Table 17--Summary of Annual and 5-Year Take Request for Training Activities
----------------------------------------------------------------------------------------------------------------
Training activities
------------------------------------------------------
MMPA Category Source Annual authorization 5-Year authorization
sought \1\ sought \2\
----------------------------------------------------------------------------------------------------------------
Mortality......................... Impulse.............. 7 mortalities applicable 35 mortalities applicable
to any small odontocete to any small odontocete
or pinniped species. or pinniped species over
five years.
Unspecified \3\...... 2 mortalities to beaked 10 mortalities to beaked
whales \3\. whales over five
years.\3\
Vessel strike........ No more than 4 large whale No more than 12 large
mortalities in any given whale mortalities over
year \4\. five years.\4\
Level A........................... Impulse and Non- 266--Species specific data 1,314--Species specific
Impulse. shown in Table 19. data shown in Table 19.
Level B........................... Impulse and Non- 1,691,123--Species 8,398,931--Species
Impulse. specific data shown in specific data shown in
Table 19. Table 19.
----------------------------------------------------------------------------------------------------------------
\1\ These numbers constitute the total for an annual maximum year (a notional 12-month period when all annual
and non-annual events could occur) in which a RIMPAC exercise and Civilian Port Defense events would occur in
Hawaii and SOCAL.
\2\ These numbers constitute the summation over a 5-year period with annual events occurring five times and non-
annual events occurring three times.
\3\ The Navy's NAEMO model did not quantitatively predict these mortalities. Navy, however, is seeking this
particular authorization given sensitivities these species may have to anthropogenic activities. Request
includes 2 Ziphidae beaked whale annually to include any combination of Cuvier's beaked whale, Baird's beaked
whale, Longman's beaked whale, and unspecified Mesoplodon sp. (not to exceed 10 beaked whales total over the 5-
year length of requested authorization).
\4\ The Navy cannot quantifiably predict that proposed takes from training will be of any particular species,
and therefore seeks take authorization for any combination of large whale species (gray whale, fin whale, blue
whale, humpback whale, Bryde's whale, sei whale, minke whale, or sperm whale), but of the four takes per year
no more than two of any one species of blue whale, fin whale, humpback whale, sei whale, or sperm whale is
requested.
Table 18--Species-Specific Take Request From Modeling Estimates of Impulsive and Non-Impulsive Source Effects for All Training Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Annually \1\ Total over 5-year rule \2\
Species Stock -----------------------------------------------------------------------
Level B Level A Mortality Level B Level A Mortality
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale.................................... Eastern North Pacific........... 4,145 0 0 20,725 0 0
Central North Pacific.......... 180 0 0 834 0 0
Fin whale..................................... California, Oregon, & Washington 1,528 0 0 7,640 0 0
Hawaiian........................ 191 0 0 891 0 0
Humpback whale................................ California, Oregon, & Washington 1,081 0 0 5,405 0 0
Central North Pacific........... 8,192 0 0 40,960 0 0
[[Page 7028]]
Sei whale..................................... Eastern North Pacific........... 146 0 0 730 0 0
Hawaiian........................ 484 0 0 2,266 0 0
Sperm whale................................... California, Oregon, & Washington 1,958 0 0 9,790 0 0
Hawaiian........................ 1,374 0 0 6,130 0 0
Guadalupe fur seal............................ Mexico.......................... 2,603 0 0 13,015 0 0
Hawaiian monk seal............................ Hawaiian........................ 1,292 0 0 6,334 0 0
Bryde's whale................................. Eastern Tropical Pacific........ 112 0 0 560 0 0
Hawaiian........................ 137 0 0 637 0 0
Gray whale.................................... Eastern North Pacific........... 9,560 2 0 47,800 10 0
Minke whale................................... California, Oregon, & Washington 359 0 0 1,795 0 0
Hawaiian........................ 447 0 0 2,235 0 0
Baird's beaked whale.......................... California, Oregon, & Washington 4,420 0 0 22,100 0 0
Blainville's beaked whale..................... Hawaiian........................ 10,316 0 0 48,172 0 0
Bottlenose dolphin............................ California coastal.............. 521 0 0 2,605 0 0
California, Oregon & Washington 26,618 0 0 133,090 0 0
offshore.
Hawaii Stock Complex............ 5,163 0 0 22,895 0 0
Cuvier's beaked whale......................... California, Oregon, & Washington 13,353 0 0 66,765 0 0
Hawaiian........................ 52,893 0 0 248,025 0 0
Dwarf sperm whale............................. Hawaiian........................ 22,359 46 0 101,291 214 0
Dall's porpoise............................... California, Oregon, & Washington 36,891 47 0 184,455 235 0
False killer whale............................ Hawaii Insular.................. 49 0 0 220 0 0
Hawaii Pelagic.................. 480 0 0 2,116 0 0
Northwest Hawaiian Islands...... 177 0 0 776 0 0
Fraser's dolphin.............................. Hawaiian........................ 2,009 0 0 8,809 0 0
Killer whale.................................. Eastern North Pacific offshore/ 321 0 0 1,605 0 0
transient.
Hawaiian........................ 182 0 0 822 0 0
Kogia spp..................................... California...................... 12,943 33 0 64,715 165 0
Long-beaked common dolphin.................... California...................... 73,113 2 0 365,565 10 0
Longman's beaked whale........................ Hawaiian........................ 3,666 0 0 17,296 0 0
Melon-headed whale............................ Hawaiian........................ 1,511 0 0 6,733 0 0
Mesoplodon beaked whales \3\.................. California, Oregon, & Washington 1,994 0 0 9,970 0 0
Northern right whale dolphin.................. California, Oregon, & Washington 51,596 1 0 257,980 5 0
Pacific white-sided dolphin................... California, Oregon, & Washington 38,467 1 0 192,335 5 0
Pantropical spotted dolphin................... Hawaiian........................ 10,887 0 0 48,429 0 0
Pygmy killer whale............................ Hawaiian........................ 571 0 0 2,603 0 0
Pygmy sperm whale............................. Hawaiian........................ 229 0 0 1,093 0 0
Risso's dolphin............................... California, Oregon, & Washington 86,564 1 0 432,820 5 0
Hawaiian........................ 1,085 0 0 4,887 0 0
Rough-toothed dolphin......................... Hawaiian........................ 5,131 0 0 22,765 0 0
Short-beaked common dolphin................... California, Oregon, & Washington 999,282 70 *3 4,996,410 350 *15
Short-finned pilot whale...................... California, Oregon, & Washington 308 0 0 1,540 0 0
Hawaiian........................ 9,150 0 0 40,760 0 0
Spinner dolphin............................... Hawaii Stock Complex............ 2,576 0 0 11,060 0 0
Striped dolphin............................... California, Oregon, & Washington 3,545 0 0 17,725 0 0
Hawaiian........................ 3,498 0 0 15,422 0 0
California sea lion........................... U.S. Stock...................... 126,961 25 *4 634,805 125 *20
Northern fur seal............................. San Miguel Island............... 20,083 5 0 100,415 25 0
Harbor seal................................... California...................... 5,906 11 0 29,530 55 0
Northern elephant seal........................ California Breeding............. 22,516 22 0 112,580 110 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ These numbers constitute the total for an annual maximum year (a notional 12-month period when all annual and non-annual events could occur) in
which a RIMPAC exercise and Civilian Port Defense events would occur in Hawaii and SOCAL.
\2\ These numbers constitute the summation over a 5-year period with annual events occurring five times and non-annual events occurring three times.
\3\ Mesoplodon spp. in SOCAL for the undifferentiated occurrence of five Mesoplodon species (M. carlhubbsi, M. ginkgodens, M. perrini, M. peruvianus, M.
stejnegeri but does not include Blainville's beaked whale listed separately above.
[[Page 7029]]
* These mortalities are considered in Table 18 as an unspecified ``any small odontocete and pinniped species.''
Testing Activities--Table 19 summarizes the Navy's take request for
testing activities and Table 20 specifies the Navy's take request for
testing activities by species from the modeling estimates.
While the Navy does not anticipate any mortalities predicted for
testing activities by the acoustic modeling would occur, the Navy
requests annual authorization for take by mortality of up to 19 small
odontocetes (i.e., dolphins) and pinnipeds to include any combination
of such species with potential presence in the Study Area as part of
testing activities using impulsive sources.
The Navy does not anticipate vessel strikes of marine mammals would
occur during testing activities in the Study Area in any given year.
Most testing conducted in the Study Area that involves surface ships is
conducted on Navy ships. Therefore, the vessel strike take request for
training activities covers those activities. For the smaller number of
testing activities not conducted in conjunction with fleet training,
the Navy requests a smaller number of takes resulting incidental to
vessel strike. However, in order to account for the accidental nature
of vessel strikes to large whales in general, and potential risk from
any vessel movement within the Study Area, the Navy is seeking take
authorization in the event a Navy vessel strike does occur while
conducting testing during the five year period of NMFS' final
authorization as follows:
The take by vessel strike during testing activities in any
given year of no more than two large whales total of any combination of
species including gray whale, fin whale, blue whale, humpback whale,
Bryde's whale, sei whale, minke whale, or sperm whale. The two takes
per year requested would be no more than one of any species of blue
whale, fin whale, humpback whale, sei whale, or sperm whale in any
given year.
The take by vessel strike of no more than three large
whales from testing activities over the course of the 5-year
regulations.
Table 19--Summary of Annual and 5-Year Take Request for Testing Activities
----------------------------------------------------------------------------------------------------------------
Testing activities
------------------------------------------------------
MMPA Category Source Annual authorization 5-Year authorization
sought sought
----------------------------------------------------------------------------------------------------------------
Mortality......................... Impulse.............. 19 mortalities applicable 95 mortalities applicable
to any small odontocete to any small odontocete
or pinniped species. or pinniped species over
five years.
Vessel strike........ No more than 2 large whale No more than 3 large
mortalities in any given whale mortalities over
year.\1\ five years.\1\
Level A........................... Impulse and Non- 145--Species specific data 725--Species specific
Impulse. shown in Table 21. data shown in Table 21.
Level B........................... Impulse and Non- 238,880--Species specific 1,194,400--Species
Impulse. data shown in Table 21. specific data shown in
Table 21.
----------------------------------------------------------------------------------------------------------------
\1\ Navy cannot quantifiably predict that the proposed takes from testing (a total of two in a given year or
over the course of 5-years) will be of any particular species, and therefore seeks take authorization for any
combination of large whale species (gray whale, fin whale, blue whale, humpback whale, Bryde's whale, sei
whale, minke whale, or sperm whale), but of the two takes in any given year, no more than one of each species
of blue whale, fin whale, humpback whale, sei whale, or sperm whale is requested.
Table 20--Species-Specific Take Requests From Modeling Estimates of Impulsive and Non-Impulsive Source Effects for All Testing Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Annually Total over 5-year rule
Species Stock -----------------------------------------------------------------------
Level B Level A Mortality Level B Level A Mortality
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale.................................... Eastern North Pacific........... 413 0 0 2,065 0 0
Central North Pacific........... 15 0 0 75 0 0
Fin whale..................................... California, Oregon, & Washington 202 0 0 1,010 0 0
Hawaiian........................ 23 0 0 115 0 0
Humpback whale................................ California, Oregon, & Washington 101 0 0 505 0 0
Central North Pacific........... 820 0 0 4,100 0 0
Sei whale..................................... Eastern North Pacific........... 21 0 0 105 0 0
Hawaiian........................ 30 0 0 150 0 0
Sperm whale................................... California, Oregon, & Washington 146 0 0 730 0 0
Hawaiian........................ 117 0 0 585 0 0
Guadalupe fur seal............................ Mexico.......................... 269 0 0 1,345 0 0
Hawaiian monk seal............................ Hawaiian........................ 358 0 0 1,790 0 0
Bryde's whale................................. Eastern Tropical Pacific........ 5 0 0 25 0 0
Hawaiian........................ 13 0 0 65 0 0
Gray whale.................................... Eastern North Pacific........... 2,570 1 0 12,850 5 0
Minke whale................................... California, Oregon, & Washington 49 0 0 245 0 0
Hawaiian........................ 30 0 0 150 0 0
Baird's beaked whale.......................... California, Oregon, & Washington 1,045 0 0 5,225 0 0
Blainville's beaked whale..................... Hawaiian........................ 960 0 0 4,800 0 0
[[Page 7030]]
Bottlenose dolphin............................ California coastal.............. 769 0 0 3,845 0 0
California, Oregon & Washington 2,407 0 0 12,035 0 0
offshore.
Hawaii Stock Complex............ 337 0 0 1,685 0 0
Cuvier's beaked whale......................... California, Oregon, & Washington 2,319 0 0 11,595 0 0
Hawaiian........................ 4,549 0 0 22,745 0 0
Dwarf sperm whale............................. Hawaiian........................ 2,376 28 0 11,880 140 0
Dall's porpoise............................... California, Oregon, & Washington 5,215 32 0 26,075 160 0
False killer whale............................ Hawaii Insular.................. 4 0 0 20 0 0
Hawaii Pelagic.................. 37 0 0 185 0 0
False killer whale............................ Northwest Hawaiian Islands...... 14 0 0 70 0 0
Fraser's dolphin.............................. Hawaiian........................ 45 0 0 225 0 0
Killer whale.................................. Eastern North Pacific offshore/ 53 0 0 265 0 0
transient.
Hawaiian........................ 14 0 0 70 0 0
Kogia spp..................................... California...................... 1,232 6 0 6,160 30 0
Long-beaked common dolphin.................... California...................... 47,851 2 0 239,255 10 0
Longman's beaked whale........................ Hawaiian........................ 436 0 0 2,180 0 0
Melon-headed whale............................ Hawaiian........................ 124 0 0 620 0 0
Mesoplodon beaked whales \1\.................. California, Oregon, & Washington 345 0 0 1,725 0 0
Northern right whale dolphin.................. California, Oregon, & Washington 5,729 1 0 28,645 5 0
Pacific white-sided dolphin................... California, Oregon, & Washington 4,924 1 0 24,620 5 0
Pantropical spotted dolphin................... Hawaiian........................ 685 2 0 3,425 10 0
Pygmy killer whale............................ Hawaiian........................ 61 0 0 305 0 0
Pygmy sperm whale............................. Hawaiian........................ 117 1 0 585 5 0
Risso's dolphin............................... California, Oregon, & Washington 8,739 1 0 43,695 5 0
Hawaiian........................ 113 0 0 565 0 0
Rough-toothed dolphin......................... Hawaiian........................ 410 0 0 2,050 0 0
Short-beaked common dolphin................... California, Oregon, & Washington 122,748 40 * 13 613,740 200 * 65
Short-finned pilot whale...................... California, Oregon, & Washington 79 0 0 395 0 0
Hawaiian........................ 797 0 0 3,985 0 0
Spinner dolphin............................... Hawaii Stock Complex............ 167 1 0 835 5 0
Striped dolphin............................... California, Oregon, & Washington 998 0 0 4,990 0 0
Hawaiian........................ 269 1 0 1,345 5 0
California sea lion........................... U.S. Stock...................... 13,038 17 * 6 65,190 85 * 30
Northern fur seal............................. San Miguel Island............... 1,088 3 0 5,440 15 0
Harbor seal................................... California...................... 892 3 0 4,460 15 0
Northern elephant seal........................ California Breeding............. 2,712 5 0 13,560 25 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Mesoplodon spp. in SOCAL for the undifferentiated occurrence of five Mesoplodon species (M. carlhubbsi, M. ginkgodens, M. perrini, M. peruvianus, M.
stejnegeri) but does not include Blainville's beaked whale listed separately above.
* These mortalities are considered in Table 20 as an unspecified ``any small odontocete and pinniped species.''
Marine Mammal Habitat
The Navy's proposed training and testing activities could
potentially affect marine mammal habitat through the introduction of
sound into the water column, impacts to the prey species of marine
mammals, bottom disturbance, or changes in water quality. Each of these
components was considered in the HSTT DEIS/OEIS and was determined by
the Navy to have no effect on marine mammal habitat. Based on the
information below and the supporting information included in the HSTT
DEIS/OEIS, NMFS has preliminarily determined that the proposed training
and testing activities would not have adverse or long-term impacts on
marine mammal habitat.
Important Marine Mammal Habitat
The only ESA-listed marine mammal with designated critical habitat
within the HSTT Study Area is the Hawaiian monk seal. Critical habitat
was first established for the Hawaiian monk seal in 1986 to include all
beach areas, sand spits and islets, lagoon waters, inner reef waters,
and ocean waters to a depth of 18.3 m around specified northwestern
Hawaiian Islands. These areas were expanded in 1988 and in 2011, NMFS
proposed that six new extensive areas in the main Hawaiian Islands be
added. However, specific areas were excluded from critical habitat
designation because it was determined that the national security
benefits of exclusion outweighed the benefits of inclusion, and that
their exclusion would not result in extinction of the species. The
excluded areas include: Kingfisher
[[Page 7031]]
Underwater Training area in marine areas off the northeast coast of
Niihau; Pacific Missile Range Facility Main Base at Barking Sands,
Kauai; Pacific Missile Range Facility Offshore Areas in marine areas
off the western coast of Kauai; the Naval Defensive Sea Area and Puuloa
Underwater Training Range in marine areas outside Pearl Harbor, Oahu;
and the Shallow Water Minefield Sonar Training Range off the western
coast of Kahoolawe in the Maui Nui area.
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. There are no known specific breeding areas within the SOCAL
Range Complex with the exception of pinnipeds. Much is unknown about
the specifics of dolphin mating, but it is presumed that these species
mate throughout their habitat and possibly throughout the year. Even
less is known about the mating habits of beaked whales. Most of the
offshore area within the SOCAL Range Complex could potentially be
utilized for active sonar activities or underwater detonations. The
Navy assumes that active sonar activities could take place within
potential mating areas of these toothed whale species within SOCAL,
although current state of knowledge is very limited and there may be
seasonal components to distribution that could account for breeding
activities outside of the SOCAL Range Complex. Baleen whales and sperm
whales breed in deep tropical and subtropical waters south and west of
the SOCAL Range Complex.
Expected Effects on Habitat
Unless the sound source or explosive detonation is stationary and/
or continuous over a long duration in one area, the effects of the
introduction of sound into the environment are generally considered to
have a less severe impact on marine mammal habitat than the physical
alteration of the habitat. Activities involving sound or energy from
sonar and other active acoustic sources would not occur on shore in
designated Hawaiian monk seal critical habitat where haul out and
resting behavior occurs and would have no effect on critical habitat at
sea. Acoustic exposures are not expected to result in long-term
physical alteration of the water column or bottom topography, as the
occurrences are of limited duration and are intermittent in time.
Surface vessels associated with the activities are present in limited
duration and are intermittent as they are continuously and relatively
rapidly moving through any given area. Most of the high-explosive
military expended materials would detonate at or near the water
surface. Only bottom-laid explosives are likely to affect bottom
substrate; habitat used for underwater detonations and seafloor device
placement would primarily be soft-bottom sediment. Once on the
seafloor, military expended material would likely be colonized by
benthic organisms because the materials would serve as anchor points in
the shifting bottom substrates, similar to a reef. The surface area of
bottom substrate affected would make up a very small percentage of the
total training area available in the HSTT Study Area.
Effects on Marine Mammal Prey
Invertebrates--Marine invertebrate distribution in the HSTT Study
Area is influenced by habitat, ocean currents, and water quality
factors such as temperature, salinity, and nutrient content (Levinton
2009). The distribution of invertebrates is also influenced by their
distance from the equator (latitude); in general, the number of marine
invertebrate species increases toward the equator (Macpherson 2002).
The higher number of species (diversity) and abundance of marine
invertebrates in coastal habitats, compared with the open ocean, is a
result of more nutrient availability from terrestrial environments and
the variety of habitats and substrates found in coastal waters
(Levinton 2009).
Marine invertebrates in the Hawaii Range Complex (HRC) portion of
the HSTT Study Area inhabit coastal waters and seafloor habitats,
including rocky intertidal zones, coral reefs, deep-water slopes,
canyons, and seamounts. Corals are the primary living structural
components of Hawaii's subtidal zone, with an average of about 20.3
percent coral coverage in the main Hawaiian Islands (Friedlander et al.
2005). Approximately 250 species of corals are found within the main
Hawaiian Islands, but the area is dominated by six species (Maragos et
al., 2004; Friedlander et al., 2005). The Northwestern Hawaiian Islands
have at least 57 species of stony coral (Maragos et al. 2004). The
coral reefs of the Northwestern Hawaiian Islands support diverse
communities of bottom-dwelling invertebrates. Over 800 non-coral
invertebrate species have been identified from the Northwestern
Hawaiian Islands. Mollusks, echinoderms, and crustaceans dominate,
representing 80 percent of the invertebrate species (Friedlander et al.
2005).
Marine invertebrates in the Southern California portion of the HSTT
Study Area inhabit coastal waters and benthic habitats, including salt
marshes, kelp forests, soft sediments, canyons, and the continental
shelf. The diverse range of species include oysters, crabs, worms,
ghost shrimp, California horn snails (Cerithidea californica), sponges,
sea fans, isopods, and stony corals (Proctor et al., 1980; Dugan et
al., 2000; Chess and Hobson, 1997). The Channel Islands, off the coast
of Southern California, are situated in a transitional location between
cold and warm water, making them host to over 5,000 invertebrate
species (Tissot et al., 2006). Soft-bottom communities of California
estuaries, such as San Diego Bay, are home to mostly crustaceans,
marine worms, and mollusks (Navy and San Diego Unified Port District,
2000).
Very little is known about sound detection and use of sound by
aquatic invertebrates (Budelmann 2010; Montgomery et al., 2006; Popper
et al., 2001). Organisms may detect sound by sensing either the
particle motion or pressure component of sound, or both. Aquatic
invertebrates probably do not detect pressure since many are generally
the same density as water and few, if any, have air cavities that would
function like the fish swim bladder in responding to pressure
(Budelmann 2010; Popper et al., 2001). Many marine invertebrates,
however, have ciliated ``hair'' cells that may be sensitive to water
movements, such as those caused by currents or water particle motion
very close to a sound source (Budelmann 2010; Mackie and Singla 2003).
These cilia may allow invertebrates to sense nearby prey or predators
or help with local navigation. Marine invertebrates may produce and use
sound in territorial behavior, to deter predators, to find a mate, and
to pursue courtship (Popper et al., 2001).
Both behavioral and auditory brainstem response studies suggest
that crustaceans may sense sounds up to three kilohertz (kHz), but best
sensitivity is likely below 200 Hz (Lovell et al., 2005; Lovell et al.
2006; Goodall et al. 1990). Most cephalopods (e.g., octopus and squid)
likely sense low-frequency sound below 1,000 Hz, with best
sensitivities at lower frequencies (Budelmann 2010; Mooney et al.,
2010; Packard et al., 1990). A few cephalopods may sense higher
frequencies up to 1,500 Hz (Hu et al., 2009). Squid did not respond to
toothed whale ultrasonic echolocation clicks at sound pressure levels
ranging from 199 to 226 dB re 1 [mu]Pa peak-to-peak, likely because
these clicks were outside of squid hearing range (Wilson et al.,
[[Page 7032]]
2007). However, squid exhibited alarm responses when exposed to
broadband sound from an approaching seismic airgun with received levels
exceeding 145 to 150 dB re 1 [mu]Pa root mean square (McCauley et al.,
2000b).
Little information is available on the potential impacts on marine
invertebrates of exposure to sonar, explosions, and other sound-
producing activities. It is expected that most marine invertebrates
would not sense mid- or high-frequency sounds, distant sounds, or
aircraft noise transmitted through the air-water interface. Most marine
invertebrates would not be close enough to intense sound sources, such
as some sonars, to potentially experience impacts to sensory
structures. Any marine invertebrate capable of sensing sound may alter
its behavior if exposed to non-impulsive sound, although it is unknown
if responses to non-impulsive sounds occur. Continuous noise, such as
from vessels, may contribute to masking of relevant environmental
sounds, such as reef noise. Because the distance over which most marine
invertebrates are expected to detect any sounds is limited and vessels
would be in transit, any sound exposures with the potential to cause
masking or behavioral responses would be brief and long-term impacts
are not expected. Although non-impulsive underwater sounds produced
during training and testing activities may briefly impact individuals,
intermittent exposures to non-impulsive sounds are not expected to
impact survival, growth, recruitment, or reproduction of widespread
marine invertebrate populations.
Most detonations would occur greater than 3 nm from shore. As water
depth increases away from shore, benthic invertebrates would be less
likely to be impacted by detonations at or near the surface. In
addition, detonations near the surface would release a portion of their
explosive energy into the air, reducing the explosive impacts in the
water. Some marine invertebrates may be sensitive to the low-frequency
component of impulsive sound, and they may exhibit startle reactions or
temporary changes in swim speed in response to an impulsive exposure.
Because exposures are brief, limited in number, and spread over a large
area, no long-term impacts due to startle reactions or short-term
behavioral changes are expected. Although individual marine
invertebrates may be injured or killed during an explosion or pile
driving, no long-term impacts on the survival, growth, recruitment, or
reproduction of marine invertebrate populations are expected.
Fish--Fish are not distributed uniformly throughout the HSTT Study
Area, but are closely associated with a variety of habitats. Some
species range across thousands of square miles while others have small
home ranges and restricted distributions (Helfman et al., 2009).
Currently 566 species of reef and shore fishes are known to occur
around the Insular Pacific-Hawaiian Large Marine Ecosystem within the
HSTT Study Area. The high number of species that are found only in
Hawaii can be explained by its geographical and hydrographical
isolation (Randall 1998). Migratory open ocean fishes, such as the
larger tunas, the billfishes, and some sharks, are able to move across
the great distance that separates the Hawaiian Islands from other
islands or continents in the Pacific. Coral reef fish communities in
the Hawaiian Islands (excluding Nihoa) show a consistent pattern of
species throughout the year. Exceptions include the seasonal
distributions of migratory, open ocean species. Several reef fish
species also show seasonal fluctuations which are usually related to
movements of juveniles into new areas or spawning activity (U. S. Navy
Office of Naval Research, 2001).
The Southern California portion of the HSTT Study Area is in a
region of highly productive fisheries (Leet et al., 2001) within the
California Current Large Marine Ecosystem. The portion of the
California Bight in the HSTT Study Area is a transitional zone between
cold and warm water masses, geographically separated by Point
Conception. The cold-water California Current Large Marine Ecosystem is
rich in microscopic plankton (diatoms, krill, and other organisms),
which form the base of the food chain in the Southern California
portion of the HSTT Study Area. Small coastal pelagic fishes depend on
this plankton and in turn are fed on by larger species (such as highly
migratory species). The high fish diversity found in the HSTT Study
Area occurs for several reasons: (1) The ranges of many temperate and
tropical species extend into Southern California; (2) the area has
complex bottom features and physical oceanographic features that
include several water masses and a changeable marine climate (Allen et
al. 2006; Horn and Allen 1978); and (3) the islands and coastal areas
provide a diversity of habitats that include soft bottom, rocky reefs,
kelp beds, and estuaries, bays, and lagoons.
All fish have two sensory systems to detect sound in the water: the
inner ear, which functions very much like the inner ear in other
vertebrates, and the lateral line, which consists of a series of
receptors along the fish's body (Popper 2008). The inner ear generally
detects relatively higher-frequency sounds, while the lateral line
detects water motion at low frequencies (below a few hundred Hz)
(Hastings and Popper 2005a). Although hearing capability data only
exist for fewer than 100 of the 32,000 fish species, current data
suggest that most species of fish detect sounds from 50 to 1,000 Hz,
with few fish hearing sounds above 4 kHz (Popper 2008). It is believed
that most fish have their best hearing sensitivity from 100 to 400 Hz
(Popper 2003b). Additionally, some clupeids (shad in the subfamily
Alosinae) possess ultrasonic hearing (i.e., able to detect sounds above
100,000 Hz) (Astrup 1999). Permanent hearing loss, or permanent
threshold shift has not been documented in fish. The sensory hair cells
of the inner ear in fish can regenerate after they are damaged, unlike
in mammals where sensory hair cells loss is permanent (Lombarte et al.
1993; Smith et al. 2006). As a consequence, any hearing loss in fish
may be as temporary as the timeframe required to repair or replace the
sensory cells that were damaged or destroyed (e.g., Smith et al. 2006).
Potential direct injuries from non-impulsive sound sources, such as
sonar, are unlikely because of the relatively lower peak pressures and
slower rise times than potentially injurious sources such as
explosives. Non-impulsive sources also lack the strong shock waves
associated with an explosion. Therefore, direct injury is not likely to
occur from exposure to non-impulsive sources such as sonar, vessel
noise, or subsonic aircraft noise. Only a few fish species are able to
detect high-frequency sonar and could have behavioral reactions or
experience auditory masking during these activities. These effects are
expected to be transient and long-term consequences for the population
are not expected. MFAS is unlikely to impact fish species because most
species are unable to detect sounds in this frequency range and vessels
operating MFAS would be transiting an area (not stationary). While a
large number of fish species may be able to detect low-frequency sonar
and other active acoustic sources, low-frequency active usage is rare
and mostly conducted in deeper waters. Overall effects to fish from
would be localized and infrequent.
Physical effects from pressure waves generated by underwater sounds
(e.g. underwater explosions) could potentially affect fish within
proximity of training or testing activities. In particular, the rapid
oscillation between high- and low-pressure peaks has the
[[Page 7033]]
potential to burst the swim bladders and other gas-containing organs of
fish (Keevin and Hemen 1997). Sublethal effects, such as changes in
behavior of fish, have been observed in several occasions as a result
of noise produced by explosives (National Research Council of the
National Academies 2003; Wright 1982). If an individual fish were
repeatedly exposed to sounds from underwater explosions that caused
alterations in natural behavioral patterns or physiological stress,
these impacts could lead to long-term consequences for the individual
such as reduced survival, growth, or reproductive capacity. However,
the time scale of individual explosions is very limited, and training
exercises involving explosions are dispersed in space and time.
Consequently, repeated exposure of individual fish to sounds from
underwater explosions is not likely and most acoustic effects are
expected to be short-term and localized. Long-term consequences for
populations would not be expected. A limited number of fish may be
killed in the immediate proximity of pile driving locations and
additional fish may be injured. Short-term effects such as masking,
stress, behavioral change, and hearing threshold shifts are also
expected during pile driving operations. However, given the relatively
small area that would be affected, and the abundance and distribution
of the species concerned, no population-level effects are expected. The
abundances of various fish and invertebrates near the detonation point
of an explosion or around a pile driving location could be altered for
a few hours before animals from surrounding areas repopulate the area;
however these populations would be replenished as waters near the sound
source are mixed with adjacent waters.
Marine Mammal Avoidance
Marine mammals may be temporarily displaced from areas where Navy
training and testing is occurring, but the area should be utilized
again after the activities have ceased. Avoidance of an area can help
the animal avoid further acoustic effects by avoiding or reducing
further exposure. The intermittent or short duration of many activities
should prevent animals from being exposed to stressors on a continuous
basis. In areas of repeated and frequent acoustic disturbance, some
animals may habituate or learn to tolerate the new baseline or
fluctuations in noise level. While some animals may not return to an
area, or may begin using an area differently due to training and
testing activities, most animals are expected to return to their usual
locations and behavior.
Other Expected Effects
Other sources that may affect marine mammal habitat were considered
in the HSTT DEIS/OEIS and potentially include the introduction of fuel,
debris, ordnance, and chemical residues into the water column. The
majority of high-order explosions would occur at or above the surface
of the ocean, and would have no impacts on sediments and minimal
impacts on water quality. While disturbance or strike from an item
falling through the water column is possible, it is unlikely because
(1) Objects sink slowly, (2) most projectiles are fired at targets (and
hit those targets), and (3) animals are generally widely dispersed
throughout the water column and over the HSTT Study Area. Chemical,
physical, or biological changes in sediment or water quality would not
be detectable. In the event of an ordnance failure, the energetic
materials it contained would remain mostly intact. The explosive
materials in failed ordnance items and metal components from training
and testing would leach slowly and would quickly disperse in the water
column. Chemicals from other explosives would not be introduced into
the water column in large amounts and all torpedoes would be recovered
following training and testing activities, reducing the potential for
chemical concentrations to reach levels that can affect sediment
quality, water quality, or benthic habitats.
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 affected 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 (e.g., 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 had 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.), as
well as the number and nature of estimated Level A harassment 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 maximum number of activity hours or detonations that
the Navy would conduct. There may be some flexibility in the exact
number of hours, items, or detonations may vary from year to year, but
totals would not exceed the 5-year totals indicated in Tables 19 and
21. Furthermore the Navy's take request is based on their model and
post-model analysis. The requested number of Level B takes does not
equate to the number of individual animals the Navy expects to harass
(which is lower), but rather to the instances of take (i.e., exposures)
that will occur. Depending on the location, duration, and frequency of
activities, along with the distribution and movement of marine mammals,
individual animals may be exposed multiple times to impulse or non-
impulse sounds at or above the Level B harassment threshold. However,
the Navy is currently unable to estimate the number of individuals that
may be taken during training and testing activities. The model results
over estimate the overall number of takes that may occur to a smaller
number of individuals. While the model shows that an increased number
of exposures may take place (compared to the 2009 rulemakings for HRC
and the SOCAL Range Complex), the types and severity of individual
responses to training and testing activities are not expected to
change.
[[Page 7034]]
Taking the above into account, considering the sections discussed
below, and dependent upon the implementation of the proposed mitigation
measures, NMFS has preliminarily determined that Navy's proposed
training and testing exercises would have a negligible impact on the
marine mammal species and stocks present in the Study Area.
Behavioral Harassment
As discussed previously in this document, marine mammals can
respond to MFAS/HFAS in many different ways, a subset of which
qualifies 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 strong sound sources to one extent or
another. Although an animal that avoids the sound source will likely
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 21)
estimating the percentage of behavioral harassment that would occur
within the 6-dB bins (without considering mitigation or avoidance). 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. As the table illustrates,
the vast majority (about 83 percent, at least for hull-mounted sonar,
which is responsible for most of the sonar takes) of calculated takes
for MFAS result from exposures between 156 dB and 162 dB. Less than 0.5
percent of the takes are expected to result from exposures above 174
dB.
Table 21--Non-Impulsive Ranges in 6-dB Bins and Ppercentage of Behavioral Harassments
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Sonar bin MF1 (e.g., SQS-53; ASW hull Sonar bin MF4 (e.g., AQS-22; ASW Sonar Bin MF5 (e.g., SSQ-62; ASW Sonar Bin HF4 (e.g., SQQ-32; MIW
mounted sonar) dipping sonar) sonobuoy) sonar)
---------------------------------------------------------------------------------------------------------------------------------------------------------------
Percentage of Percentage of Percentage of Percentage of
Received level Distance at which behavioral Distance at which behavioral Distance at which behavioral Distance at which behavioral
levels occur harassments levels occur harassments levels occur harassments levels occur harassments
within radius of occurring at given within radius of occurring at given within radius of occurring at given within radius of occurring at given
source (m) levels source (m) levels source (m) levels source (m) levels
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Low Frequency Cetaceans
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
120 <=SPL <126.................. 172,558-162,925... 0.00.............. 40,000-40,000..... 0.00.............. 23,880-17,330..... 0.00.............. 3,100-2,683....... 0.00
126 <=SPL <132.................. 162,925-117,783... 0.00.............. 40,000-40,000..... 0.00.............. 17,330-12,255..... 0.10.............. 2,683-2,150....... 0.01
132 <=SPL <138.................. 117,783-108,733... 0.04.............. 40,000-12,975..... 3.03.............. 12,255-7,072...... 4.12.............. 2,150-1,600....... 0.48
138 <=SPL <144.................. 108,733-77,850.... 1.57.............. 12,975-12,800..... 0.14.............. 7,072-3,297....... 23.69............. 1,600-1,150....... 4.20
144 <=SPL <150.................. 77,850-58,400..... 5.32.............. 12,800-6,525...... 27.86............. 3,297-1,113....... 42.90............. 1,150-575......... 24.79
150 <=SPL <156.................. 58,400-53,942..... 4.70.............. 6,525-2,875....... 36.83............. 1,113-255......... 24.45............. 575-300........... 28.10
156 <=SPL <162.................. 53,942-8,733...... 83.14............. 2,875-1,088....... 23.78............. 255-105........... 3.52.............. 300-150........... 24.66
162 <=SPL <168.................. 8,733-4,308....... 3.51.............. 1,088-205......... 7.94.............. 105-55............ 1.08.............. 150-100........... 9.46
168 <=SPL <174.................. 4,308-1,950....... 1.31.............. 205-105........... 0.32.............. 55-55............. 0.00.............. 100-<50........... 8.30
174 <=SPL <180.................. 1,950-850......... 0.33.............. 105-55............ 0.10.............. 55-55............. 0.00.............. <50............... 0.00
180 <=SPL <186.................. 850-400........... 0.06.............. 55-<50............ 0.01.............. 55-<50............ 0.13.............. <50............... 0.00
186 <=SPL <192.................. 400-200........... 0.01.............. <50............... 0.00.............. <50............... 0.00.............. <50............... 0.00
192 <= SPL <198................. 200-100........... 0.00.............. <50............... 0.00.............. <50............... 0.00.............. <50............... 0.00
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Mid-Frequency Cetaceans
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
120 <= SPL <126................. 172,592-162,933... 0.00.............. 40,000-40,000..... 0.00.............. 24,205-18,872..... 0.00.............. 4,133-3,600....... 0.00
126 <= SPL <132................. 162,933-124,867... 0.00.............. 40,000-40,000..... 0.00.............. 18,872-12,697..... 0.10.............. 3,600-3,075....... 0.00
132 <= SPL <138................. 124,867-108,742... 0.07.............. 40,000-12,975..... 2.88.............. 12,697-7,605...... 3.03.............. 3,075-2,525....... 0.01
138 <= SPL <144................. 108,742-78,433.... 1.54.............. 12,975-12,800..... 0.02.............. 7,605-4,080....... 17.79............. 2,525-1,988....... 0.33
144 <= SPL <150................. 78,433-58,650..... 5.41.............. 12,800-6,525...... 26.73............. 4,080-1,383....... 46.83............. 1,988-1,500....... 2.83
150 <= SPL <156................. 58,650-53,950..... 4.94.............. 6,525-2,875....... 36.71............. 1,383-300......... 27.08............. 1,500-1,000....... 14.92
156 <= SPL <162................. 53,950-8,925...... 82.62............. 2,875-1,088....... 25.65............. 300-155........... 3.06.............. 1,000-500......... 40.11
162 <= SPL <168................. 8,925-4,375....... 3.66.............. 1,088-205......... 7.39.............. 155-55............ 2.02.............. 500-300........... 22.18
168 <= SPL <174................. 4,375-1,992....... 1.34.............. 205-105........... 0.52.............. 55-55............. 0.00.............. 300-150........... 14.55
174 <= SPL <180................. 1,992-858......... 0.34.............. 105-55............ 0.09.............. 55-55............. 0.00.............. 150-<50........... 5.07
180 <= SPL <186................. 858-408........... 0.06.............. 55-<50............ 0.01.............. 55-<50............ 0.09.............. <50............... 0.00
186 <= SPL <192................. 408-200........... 0.01.............. <50............... 0.00.............. <50............... 0.00.............. <50............... 0.00
192 <= SPL <198................. 200-100........... 0.00.............. <50............... 0.00.............. <50............... 0.00.............. <50............... 0.00
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
ASW: anti-submarine warfare; MIW: mine warfare; m: meter; SPL: sound pressure level
Although the Navy has been monitoring to discern the effects of
MFAS/HFAS on marine mammals since 2006, and research on the effects of
MFAS is advancing, our understanding of exactly how marine mammals in
the Study Area will respond to MFAS/HFAS is still limited. The Navy has
submitted reports from more than 60 major exercises conducted in the
HRC and SOCAL, and off the Atlantic Coast, that indicate no behavioral
disturbance was observed. One cannot conclude from these results that
marine mammals were not harassed from MFAS/HFAS, as 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 spp.), the
full series of behaviors that would more accurately show an important
change is not typically seen (i.e., only the surface behaviors are
observed), 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 did not respond in any of the obviously more
severe ways, such as panic, aggression, or anti-predator response.
Diel Cycle
As noted previously, many animals perform vital functions, such as
feeding, resting, traveling, and socializing on a diel cycle (24-hour
cycle). Behavioral reactions to noise exposure (when taking place in a
biologically important context, such as disruption of critical life
functions, displacement, or avoidance of important habitat) are more
likely to be significant if they last
[[Page 7035]]
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 severe unless it
could directly affect reproduction or survival (Southall et al., 2007).
In the previous section, we discussed that potential behavioral
responses to MFAS/HFAS that fall into the category of harassment could
range in severity. By definition, for military readiness activities,
takes by behavioral harassment involve the disturbance or likely
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 hrs or be repeated in subsequent days. However, vessels
with hull-mounted active sonar are typically moving at speeds of 10-15
knots, which would make it unlikely that the same animal could remain
in the immediate vicinity of the ship for the entire duration of the
exercise. Animals may be exposed to MFAS/HFAS for more than one day or
on successive days. However, because neither the vessels nor the
animals are stationary, significant long-term effects are not expected.
Most planned explosive exercises are of a short duration (1-6
hours). Although explosive exercises may sometimes be conducted in the
same general areas repeatedly, because of their short duration and the
fact that they are in the open ocean and animals can easily move away,
it is similarly unlikely that animals would be exposed for long,
continuous amounts of time. TTS
As mentioned previously, TTS can last from a few minutes to days,
be of varying degree, and occur across various frequency bandwidths,
all of which determine the severity of the impacts on the affected
individual, which can range from minor to more severe. The TTS
sustained by an animal is primarily classified by three
characteristics:
1. Frequency--Available data (of mid-frequency hearing specialists
exposed to mid- or high-frequency sounds; Southall et al., 2007)
suggest that most TTS occurs in the frequency range of the source up to
one octave higher than the source (with the maximum TTS at [frac12]
octave above). The more powerful MF sources used have center
frequencies between 3.5 and 8 kHz and the other unidentified MF sources
are, by definition, less than 10 kHz, which suggests that TTS induced
by any of these MF sources would be in a frequency band somewhere
between approximately 2 and 20 kHz. There are fewer hours of HF source
use and the sounds would attenuate more quickly, plus they have lower
source levels, but if an animal were to incur TTS from these sources,
it would cover a higher frequency range (sources are between 20 and 100
kHz, which means that TTS could range up to 200 kHz; however, HF
systems are typically used less frequently and for shorter time periods
than surface ship and aircraft MF systems, so TTS from these sources is
even less likely). TTS from explosives would be broadband. Vocalization
data for each species was provided in the Navy's LOA application.
2. 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 was
discussed previously in this document. 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 lookouts and the nominal speed of an active
sonar vessel (10-15 knots). In the 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-second exposure to a 20 kHz source. However, MFAS emits a
nominal ping every 50 seconds, and incurring those levels of TTS is
highly unlikely.
3. Duration of TTS (recovery time)--In the TTS laboratory studies,
some using exposures of almost an hour in duration or up to 217 SEL,
almost all individuals recovered within 1 day (or less, often in
minutes), though in one study (Finneran et al., 2007), recovery took 4
days.
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 in the Study Area, it is unlikely
that marine mammals would ever sustain a TTS from MFAS that alters
their sensitivity by more than 20 dB for more than a few days (and any
incident of TTS would likely be far less severe due to the short
duration of the majority of the exercises and the speed of a typical
vessel). Also, for the same reasons discussed in the Diel Cycle
section, and because of the short distance within which animals would
need to approach the sound source, it is unlikely that animals would be
exposed to the levels necessary to induce TTS in subsequent time
periods such that their recovery is impeded. Additionally, though the
frequency range of TTS that marine mammals might sustain would overlap
with some of the frequency ranges of their vocalization types, the
frequency range of TTS from MFAS (the source from which TTS would most
likely be sustained because the higher source level and slower
attenuation make it more likely that an animal would be exposed to a
higher received level) would not usually span the entire frequency
range of one vocalization type, much less span all types of
vocalizations. If impaired, marine mammals would typically be aware of
their impairment and implement behaviors to compensate (see Acoustic
Masking or Communication Impairment section), though these
compensations may incur energetic costs.
Acoustic Masking or Communication Impairment
Masking only occurs during the time of the signal (and potential
secondary arrivals of indirect rays), versus TTS, which continues
beyond the duration of the signal. Standard MFAS nominally pings every
50 seconds for hull-mounted sources. For the sources for which we know
the pulse length, most are significantly shorter than hull-mounted
active sonar, on the order of several microseconds to tens of
microseconds. For hull-mounted active sonar, though some of the
vocalizations that marine mammals make are less than one second long,
there is only a 1 in 50 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. Alternately, when the pulses are only
several microseconds long, the majority of most animals' vocalizations
would not be 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
the signal length, frequency, and duty cycle of the MFAS/HFAS signal
does not perfectly mimic the characteristics of any marine mammal's
vocalizations.
[[Page 7036]]
PTS, Injury, or Mortality
NMFS believes that many marine mammals would deliberately avoid
exposing themselves to the received levels of active sonar necessary to
induce injury by moving away from or at least modifying their path to
avoid a close approach. Additionally, 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/
HFAS) would typically ensure that animals would not be exposed to
injurious levels of sound. As discussed previously, the Navy utilizes
both aerial (when available) and passive acoustic monitoring (during
all ASW exercises) in addition to watchstanders on vessels to detect
marine mammals for mitigation implementation.
If a marine mammal is able to approach a surface vessel within the
distance necessary to incur PTS, the likely speed of the vessel
(nominal 10-15 knots) would make it very difficult for the animal to
remain in range long enough to accumulate enough energy to result in
more than a mild case of PTS. As mentioned previously and in relation
to TTS, the likely consequences to the health of an individual that
incurs PTS can range from mild to more serious dependent upon the
degree of PTS and the frequency band it is in, and many animals are
able to compensate for the shift, although it may include energetic
costs.
As discussed previously, marine mammals (especially beaked whales)
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 mechanism of this potential response, behavioral
or physiological, is not known. When naval exercises have been
associated with strandings in the past, it has typically been when
three or more vessels are operating simultaneously, in the presence of
a strong surface duct, and in areas of constricted channels, semi-
enclosed areas, and/or steep bathymetry. Based on the number of
occurrences where strandings have been definitively associated with
military active sonar versus the number of hours of active sonar
training that have been conducted, we believe that the probability is
small that this will occur. Lastly, an active sonar shutdown protocol
for strandings involving live animals milling in the water minimizes
the chances that these types of events turn into mortalities.
While NMFS does not expect any mortalities from impulsive sources
to occur, we are proposing to authorize takes by mortality of a limited
number of small odontocetes and pinnipeds from training and testing
activities. Based on previous vessel strikes in the Study Area, NMFS is
also proposing to authorize takes by mortality of a limited number of
large whales from vessel strike. As described previously, although we
have a good sense of how many marine mammals the Navy may strike over
the course of 5 years (and it is much smaller than the 15 large whale
mortalities requested for all training and testing activities), the
species distribution is unpredictable. Thus, we have analyzed the
possibility that all large whale takes requested in one year may be of
the same species. However, the number of takes authorized of a single
species is limited (for example, no more than three takes of any one of
the following species may occur in a single year: blue whale, fin
whale, humpback whale, sei whale, and sperm whale). Over the first
three years of the existing HRC and SOCAL rules, five mortalities have
resulted from activities that would be covered by the HSTT rule: two
mortalities from ship strike, and three confirmed mortalities from
explosive exercises (which occurred before the monitoring was modified
to its current form, which better protects animals when time-delay
firing devices are used). The number of mortalities from vessel strikes
are not expected to be an increase over the past decade, but rather
they are being addressed under the incidental take authorization for
the first time.
Species-Specific Analysis
In the discussions below, the ``acoustic analysis'' refers to the
Navy's model results and post-model analysis. The Navy performed a
quantitative analysis to estimate the number of marine mammals that
could be harassed by acoustic sources or explosives used during Navy
training and testing activities. Inputs to the quantitative analysis
included marine mammal density estimates; marine mammal depth
occurrence distributions; oceanographic and environmental data; marine
mammal hearing data; and criteria and thresholds for levels of
potential effects. Marine mammal densities used in the model may
overestimate actual densities when species data is limited and for
species with seasonal migrations (e.g., humpbacks, blue whales,
Hawaiian stock of fin whales, sei whales, gray whales). The
quantitative analysis consists of computer modeled estimates and a
post-model analysis to determine the number of potential mortalities
and harassments. The model calculates sound energy propagation from
sonars, other active acoustic sources, and explosives during naval
activities; the sound or impulse received by animat dosimeters
representing marine mammals distributed in the area around the modeled
activity; and whether the sound or impulse received by a marine mammal
exceeds the thresholds for effects. The model estimates are then
further analyzed to consider animal avoidance and implementation of
mitigation measures, resulting in final estimates of effects due to
Navy training and testing. It is important to note that the Navy's take
estimates represent the total number of takes and not the number of
individuals taken, as a single individual may be taken multiple times
over the course of a year.
Although this more complex computer modeling approach accounts for
various environmental factors affecting acoustic propagation, the
current software tools do not consider the likelihood that a marine
mammal would attempt to avoid repeated exposures to a sound or avoid an
area of intense activity where a training or testing event may be
focused. Additionally, the software tools do not consider the
implementation of mitigation (e.g., stopping sonar transmissions when a
marine mammal is within a certain distance of a ship or range clearance
prior to detonations). In both of these situations, naval activities
are modeled as though an activity would occur regardless of proximity
to marine mammals and without any horizontal movement by the animal
away from the sound source or human activities (e.g., without
accounting for likely animal avoidance). The initial model results
overestimate the number of takes (as described previously), primarily
by behavioral disturbance. The final step of the quantitative analysis
of acoustic effects is to consider the implementation of mitigation and
the possibility that marine mammals would avoid continued or repeated
sound exposures. NMFS provided input to the Navy on this process and
the Navy's qualitative analysis is described in detail in section 6.3
of their LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications).
Mysticetes--The Navy's acoustic analysis indicates that numerous
exposures of mysticete species to sound levels likely to result in
Level B harassment may occur, mostly from sonar and other active
acoustic stressors associated with mostly training and
[[Page 7037]]
some testing activities in the HSTT Study Area. Of these species,
humpback, blue, fin, and sei whales are listed as endangered under the
ESA. Level B takes are anticipated to be in the form of behavioral
harassment and no injurious takes of humpback, blue, fin, or sei whales
from sonar, or other active acoustic stressors are expected. The
majority of acoustic effects to mysticetes from sonar and other active
sound sources during training activities would be primarily from anti-
submarine warfare events involving surface ships and hull mounted (mid-
frequency) sonar. Most Level B harassments to mysticetes from sonar
would result from received levels between 144 and 162 SPL. High-
frequency systems are not within mysticetes' ideal hearing range and it
is unlikely that they would cause a significant behavioral reaction.
The only mysticete species that may be exposed to sound or energy from
explosions resulting in the possibility of PTS is the gray whale.
Exposures would occur in the SOCAL Range Complex during the cool season
However, the Navy's proposed mitigation zones for explosive activities
extend beyond the predicted maximum range to PTS. The implementation of
mitigation and the sightability of mysticetes (due to their large size)
reduces the potential for a significant behavioral reaction or a
threshold shift to occur. Furthermore, gray whales in particular should
be easier to sight because they would be migrating through the HSTT
Study Area and there is often more than one whale in an area at the
same time.
In addition to Level B takes, the Navy is requesting no more than
12 large whale mortalities over 5 years (no more than 4 large whale
mortalities in a given year) due to vessel strike during training
activities and no more than three large whale mortalities over 5 years
(no more than 2 large whale mortalities in any given year) due to
vessel strike during testing activities. However, no more than three
mortalities of any of the following species would be authorized to
occur in a given year: blue whale, fin whale, humpback whale, sei
whale, and sperm whale. The Navy provided a detailed analysis of strike
data in section 6.3.4 of their LOA application. Marine mammal
mortalities were not previously analyzed by NMFS in the 2009
rulemakings for HRC and the SOCAL Range Complex. However, over a period
of 20 years (1991 to 2010), there have been 16 Navy vessel strikes in
the SOCAL Range Complex and five Navy vessel strikes in HRC. No single
5-year period exceeded ten whales struck within SOCAL and HRC. The
number of mortalities from vessel strike are not expected to be an
increase over the past decade, but rather NMFS is proposing to
authorize these takes for the first time.
Areas of high humpback whale density in the HRC were discussed
earlier in this document. Since humpback whales migrate to the north in
the summer, impacts are predicted only for the cool season in the HSTT
Study Area. While the humpback breeding areas around Hawaii are
important, NMFS has determined that MFAS training in these areas is
rare and infrequent and should not affect annual rates of recruitment
or survival. As discussed in the Proposed Mitigation section of this
document, the Navy has agreed that training exercises in the designated
Humpback Whale Cautionary Area would require a much higher level of
clearance than is normal practice in planning and conducting MFAS
training. Furthermore, no reported cases of harmful effects to humpback
whales attributed to MFAS use have occurred during the Navy's 40-plus
years of training in the waters off the Hawaiian Islands. Coincident
with this use of MFAS, abundance estimates reflect an annual increase
in the humpback whale stock (Mobley 2001a, 2004). A recent long-term
study of humpback whales in Hawaiian waters shows long-term fidelity to
the Hawaiian winter grounds, with many showing sighting spans ranging
from 10 to 32 years (Herman et al., 2011). The overall abundance of
humpback whales in the north Pacific has continued to increase and is
now greater than some pre-whaling abundance estimates (Barlow et al.,
2011). The California, Oregon, Washington stock of humpback whales use
the waters within the Southern California portion of the HSTT Study
Area as a summer feeding ground. No areas of specific importance for
reproduction or feeding for other mysticetes have been identified in
the HSTT Study Area.
Sperm Whales--The Navy's acoustic analysis indicates that 3,595
exposures of sperm whales to sound levels likely to result in Level B
harassment may occur in the HSTT Study Area from sonar or other active
acoustic stressors during training and testing activities. These Level
B takes are anticipated to be in the form of behavioral harassment and
no injurious takes of sperm whales from sonar, other active acoustic
stressors, or explosives are requested or proposed for authorization.
Sperm whales have shown resilience to acoustic and human disturbance,
although they may react to sound sources and activities within a few
kilometers. Sperm whales that are exposed to activities that involve
the use of sonar and other active acoustic sources may alert, ignore
the stimulus, avoid the area by swimming away or diving, or display
aggressive behavior. Some (but not all) sperm whale vocalizations might
overlap with the MFAS/HFAS TTS frequency range, which could temporarily
decrease an animal's sensitivity to the calls of conspecifics or
returning echolocation signals. However, as noted previously, NMFS does
not anticipate TTS of a long duration or severe degree to occur as a
result of exposure to MFAS/HFAS. The majority of Level B takes are
expected to be in the form of mild responses. No areas of specific
importance for reproduction or feeding for sperm whales have been
identified in the HSTT Study Area.
Pygmy and Dwarf Sperm Whales--The Navy's acoustic analysis
indicates that 25,081 exposures of pygmy and dwarf sperm whales to
sound levels likely to result in Level B harassment may occur from
sonar and other active acoustic stressors and explosives associated
with training and testing activities in the HRC. In SOCAL, the two
Kogia species are managed as a single stock and management unit and up
to 14,175 exposures to sound levels likely to result in Level B
harassment may occur from sonar and other active acoustic stressors and
explosives associated with training and testing activities. The Navy's
acoustic analysis also indicates that 74 exposures of dwarf sperm whale
and one exposure of pygmy sperm whale to sound levels likely to result
in Level A harassment may occur from active acoustic stressors and
explosions in HRC and 39 exposures of Kogia to sound levels likely to
result in Level A harassment may occur from active acoustic stressors
or explosions in SOCAL. Behavioral responses can range from a mild
orienting response, or a shifting of attention, to flight and panic.
These species tend to avoid human activity and presumably anthropogenic
sounds. Pygmy and dwarm sperm whales may startle and leave the
immediate area of activity, reducing the potential impacts. Significant
behavioral reactions seem more likely than with most other odontocetes;
however, it is unlikely that animals would receive multiple exposures
over a short period of time, allowing animals to recover lost resources
(e.g., food) or opportunities (e.g., mating). Therefore, long-term
consequences for individual Kogia or their respective populations are
not expected. Furthermore, many explosions actually occur upon impact
[[Page 7038]]
with above-water targets. However, sources such as these were modeled
as exploding at 1 meter depth, which overestimates the potential
effects.
Data from several sources, which are summarized and cited on NOAA's
Cetacean and Sound Mapping Web site (cetsound.noaa.gov) indicate that
there are resident populations of dwarf sperm whales (among other
species) off the western side of the Big Island of Hawaii. As discussed
earlier, we highlight the presence of resident populations in the
interest of helping to support decisions that ensure that these small
populations, limited to a small area of preferred habitat, are not
exposed to concentrations of activities within their ranges that have
the potential to impact a large portion of the stock/species over
longer amounts of time that could have detrimental consequences to the
stock/species. However, NMFS has reviewed the Navy's exercise reports
and considered/discussed their historical level of activity in the area
where these resident populations are concentrated, which is very low,
and concluded that time/area restrictions would not afford much
reduction of impacts in this location and are not necessary at this
point. If future monitoring and exercise reports suggest that increased
operations are overlapping with these resident populations, NMFS would
revisit the consideration of time/area limitations around these
populations.
Dall's Porpoise--The Navy's acoustic analysis indicates that 42,106
exposures of Dall's porpoise to sound levels likely to result in Level
B Harassment may occur from sonar and other active acoustic stressors
and explosives associated with training and testing activities in the
SOCAL Range Complex. The analysis also indicates that 79 exposures to
sound levels likely to result in Level A Harassment may occur from
sonar and other active acoustic stressors.
Predicted impacts to odontocetes from activities from sonar and
other active acoustic sources are mostly from anti-submarine warfare
events involving surface ships and hull mounted sonar. For high-
frequency cetaceans, such as Dall's porpoise, ranges to TTS for
multiple pings can, under certain conditions, reach over 10 km from a
source. Activities involving ASW training often involve multiple
participants and activities associated with the event. Sensitive
species, such as Dall's porpoise, may avoid the area for the duration
of the event and then return, allowing the animal to recover from any
energy expenditure or missed resources. However, the Navy's proposed
mitigation has a provision that allows the Navy 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, they could potentially be exposed to
levels associated with TTS. Some dolphin vocalizations might overlap
with the MFAS/HFAS TTS frequency range (2-20 kHz), which could
potentially temporarily decrease an animal's sensitivity to the calls
of conspecifics or returning echolocation signals. However, for the
reasons described in the beginning of this section, NMFS does not
anticipate TTS of a long duration or severe degree to occur as a result
of exposure to MFA/HFAS.
Ranges to PTS are on average about 855 meters from the largest
explosive (Bin E12) for a high-frequency cetacean such as Dall's
porpoise, which is less than the proposed mitigation zone for most
explosive source bins. The metrics used to estimate PTS are based on
the animal's mass; the smaller an animal, the more susceptible that
individual is to these effects. In the Navy's analysis, all individuals
of a given species were assigned the weight of that species' newborn
calf. Since many individual Dall's porpoise are obviously larger than a
newborn calf, this assumption causes the acoustic model to overestimate
the potential effects. Threshold shifts do not necessarily affect all
hearing frequencies equally, so some threshold shifts may not interfere
with an animal hearing biologically relevant sounds.
Odontocetes, such as Dall's porpoise, may further minimize sound
exposure during avoidance due to directional hearing. No areas of
specific importance for reproduction or feeding for Dall's porpoise
have been identified in the HSTT Study Area.
Beaked Whales--The Navy's acoustic analysis indicates that numerous
exposures of beaked whale species to sound levels likely to result in
Level B Harassment may occur from sonar and other active acoustic
stressors associated with training and testing activities. Research and
observations show that if beaked whales are exposed to sonar or other
active acoustic sources they may startle, break off feeding dives, and
avoid the area of the sound source to levels of 157 dB (McCarthy et
al., 2011). Furthermore, in research done at the Navy's instrumented
tracking range in the Bahamas, animals leave the immediate area of the
anti-submarine warfare training exercise, but return within a few days
after the event ends. At the Bahamas range and at Navy instrumented
ranges in the HSTT Study Area that have been operating for decades (in
Hawaii north of Kauai and in SOCAL west of San Clemente Island),
populations of beaked whales appear to be stable. The analysis also
indicates that no exposures to sound levels likely to result in Level A
Harassment would occur. However, while the Navy's model did not
quantitatively predict any mortalities of beaked whales, the Navy is
requesting a limited number of takes by mortality given the
sensitivities these species may have to anthropogenic activities.
Almost 40 years of conducting similar exercises in the HSTT Study Area
without observed incident indicates that injury or mortality are not
expected to occur as a result of Navy activities.
Some beaked whale vocalizations might overlap with the MFAS/HFAS
TTS frequency range (2-20 kHz), which could potentially temporarily
decrease an animal's sensitivity to the calls of conspecifics or
returning echolocation signals. However, NMFS does not anticipate TTS
of a long duration or severe degree to occur as a result of exposure to
MFA/HFAS. No beaked whales are predicted to be exposed to MFAS/HFAS
sound levels associated with PTS or injury. No areas of specific
importance for reproduction or feeding for beaked whales have been
identified in the HSTT Study Area.
As discussed previously, scientific uncertainty exists regarding
the potential contributing causes of beaked whale strandings and the
exact behavioral or physiological mechanisms that can potentially lead
to the ultimate physical effects (stranding and/or death) that have
been documented in a few cases. Although NMFS does not expect injury or
mortality of any of these species to occur as a result of the MFAS/HFAS
training exercises, there remains the potential for the operation of
MFAS to contribute to the mortality of beaked whales. Consequently,
NMFS intends to authorize mortality and we consider the 10 potential
mortalities from across the seven species potentially effected over the
course of 5 years in our negligible impact determination (NMFS only
intends to authorize a total of 10 beaked whale mortality takes, but
since they could be of any of the species, we consider the effects of
10 mortalities of any of the seven species).
False Killer Whale--The Navy's acoustic analysis indicates that 761
exposures of false killer whales (53 exposures to the Hawaii insular
stock) to sound levels likely to result in Level B harassment may occur
from sonar or other active acoustic stressors associated with training
and testing activities in the HRC. False killer whales are not
[[Page 7039]]
expected to be present within the SOCAL Range Complex. These takes are
anticipated to be in the form of behavioral harassment and no injurious
takes of false killer whales from active acoustic stressors or
explosives are requested or proposed for authorization. Behavioral
responses can range from a mild orienting response, or a shifting of
attention, to flight and panic.
No areas of specific importance for reproduction or feeding for
false killer whales have been identified in the HSTT Study Area.
Short-beaked Common Dolphin--The Navy's acoustic analysis indicates
that 1,122,030 exposures of short-beaked common dolphins to sound
levels likely to result in Level B Harassment may occur from sonar and
other active acoustic stressors associated with training and testing
activities and sound or energy from explosions. Analysis also indicates
that 110 exposures to sound levels likely to result in Level A
Harassment may occur from active acoustic stressors and sound or energy
from explosions. Up to 16 short-beaked common dolphin mortalities are
also requested as part of an unspecified ``any small odontocete and
pinniped species'' take. Short-beaked common dolphins are one of the
most abundant dolphin species in SOCAL. Behavioral responses can range
from alerting, to changing their behavior or vocalizations, to avoiding
the sound source by swimming away or diving. The high take numbers are
due in part to an increase in expended materials. However, this species
generally travels in large pods and should be visible from a distance
in order to implement mitigation measures and reduce potential impacts.
No areas of specific importance for reproduction or feeding for
short-beaked common dolphins have been identified in the HSTT Study
Area.
California Sea Lion--The Navy's acoustic analysis indicates that
139,999 exposures of California sea lions to sound levels likely to
result in Level B harassment may occur from sonar and other active
acoustic stressors associated with training and testing activities and
sound or energy from explosions. Analysis also indicates that 42
exposures to sound levels likely to result in Level A Harassment may
occur from active acoustic stressors and sound or energy from
explosions. Up to 10 California sea lion mortalities are also requested
as part of an unspecified ``any small odontocete and pinniped species''
take. California sea lions are the most abundant pinniped species along
the California coast. Research and observations show that pinnipeds in
the water are tolerant of anthropogenic noise and activity. California
sea lions may not react at all until the sound source is approaching
within a few hundred meters and then may alert, ignore the stimulus,
change their behavior, or avoid the immediate area by swimming away or
diving. Significant behavioral reactions are not expected, based on
previous observations. The high take numbers are due in part to the
explosive criteria being based on newborn calf weights. Assuming that
the majority of the population is larger than a newborn calf, the model
overestimates the effects to California sea lions. The criteria for
slight lung injury are also very conservative and may overpredict the
effects. Research and observations show that pinnipeds in the water are
tolerant of anthropogenic noise and activity. They may react in a
number of ways depending on their experience with the sound source and
what activity they are engaged in at the time of the exposure.
Northern Fur Seal--The Navy's acoustic analysis indicates that
21,171 exposures of northern fur seals to sound levels likely to result
in Level B Harassment may occur from sonar and other active acoustic
stressors associated with training and testing activities in the SOCAL
Range Complex and sound or energy from explosions. Analysis also
indicates that eight exposures to sound levels likely to result in
Level A Harassment may occur from active acoustic stressors and sound
or energy from explosions. Northern fur seals are common in SOCAL.
Behavioral responses can range from a mild orienting response, or a
shifting of attention, to flight and panic. Research and observations
show that pinnipeds in the water are tolerant of anthropogenic noise
and activity. They may react in a number of ways depending on their
experience with the sound source and what activity they are engaged in
at the time of the exposure.
A small population breeds on San Miguel Island, outside of the
SOCAL Range Complex.
Northern Elephant Seal--The Navy's acoustic analysis indicates that
25,228 exposures of northern elephant seals to sound levels likely to
result in Level B Harassment may occur from sonar and other active
acoustic stressors associated with training and testing activities in
the SOCAL Range Complex and sound or energy from explosions. Analysis
also indicates that 27 exposures to sound levels likely to result in
Level A Harassment may occur from active acoustic stressors and sound
or energy from explosions. The majority of predicted effects would be
from anti-submarine warfare events involving surface ships, submarines,
and hull mounted sonar, while a small percentage of effects would be
from mine countermeasure events. Northern elephant seals are common in
SOCAL and the proposed take is less than 21 percent of the California
breeding population. Behavioral responses can range from a mild
orienting response, or a shifting of attention, to flight and panic.
Research and observations show that pinnipeds in the water are tolerant
of anthropogenic noise and activity. They may react in a number of ways
depending on their experience with the sound source and what activity
they are engaged in at the time of the exposure.
Different age classes of northern elephant seals haul out on the
Channel Islands within SOCAL and spend 8-10 months at sea each year.
Hawaiian Monk Seal--The Navy's acoustic analysis indicates that
1,650 exposures of Hawaiian monk seals (listed as endangered under the
ESA) to sound levels likely to result in Level B harassment may occur
from sonar or other active acoustic stressors associated with training
and testing activities in HRC. No exposures to sound levels likely to
result in Level A harassment are expected to occur and takes from
injury or mortality are not requested or proposed for authorization.
The majority of exposures from testing have ranges to TTS less than 50
m. Behavioral effects are not expected to be significant because (1)
Significant behavioral effects are more likely at higher received
levels within a few kilometers of the source, (2) Hawaiian monk seals
may avoid the activity area; and (3) mitigation measures would be
implemented. Hawaiian monk seals predominantly occur in the
Northwestern Hawaiian Islands and the Papahanaumokuakea National Marine
Monument, which is outside of the main Hawaii Operating Area. Ranges to
TTS for hull mounted sonars can be on the order of several kilometers
for monk seals, and some behavioral impacts could take place at
distances exceeding 173 km, although significant behavioral effects are
much more likely at higher received levels within a few kilometers of
the sound source and therefore, the majority of behavioral effects are
not expected to be significant. Activities involving sound or energy
from sonar and other active acoustic sources would not occur on shore
in designated Hawaiian monk seal critical habitat where haul out and
resting behavior occurs and would have no effect on critical habitat at
sea.
[[Page 7040]]
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 and monitoring measures, NMFS
preliminarily finds that the total taking from Navy training and
testing exercises in the HSTT Study Area will have a negligible impact
on the affected species or stocks. NMFS has proposed regulations for
these exercises that prescribe the means of effecting the least
practicable adverse impact on marine mammals and their habitat and set
forth requirements pertaining to the monitoring and reporting of that
taking.
Subsistence Harvest of Marine Mammals
NMFS has preliminarily determined that the issuance of 5-year
regulations and subsequent LOAs for Navy training and testing exercises
in the HSTT Study Area 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 eight marine mammal species under NMFS jurisdiction that
are listed as endangered or threatened under the ESA with confirmed or
possible occurrence in the Study Area: blue whale, humpback whale, fin
whale, sei whale, sperm whale, the Hawaiian insular stock of false
killer whale, Guadalupe fur seal, and Hawaiian monk seal. The Navy will
consult with NMFS pursuant to section 7 of the ESA, and NMFS will also
consult internally on the issuance of LOAs under section 101(a)(5)(A)
of the MMPA for HSTT activities. Consultation will be concluded prior
to a determination on the issuance of the final rule and an LOA.
NMSA
Some Navy activities may potentially affect resources within
National Marine Sanctuaries. The Navy will continue to analyze
potential impacts to sanctuary resources and has provided the analysis
in the Navy's HSTT DEIS/OEIS to NOAA's Office of National Marine
Sanctuaries. The Navy will initiate consultation with NOAA's Office of
National Marine Sanctuaries pursuant to the requirements of the NMSA as
warranted by ongoing analysis of the activities and their effects on
sanctuary resources.
NEPA
NMFS has participated as a cooperating agency on the HSTT DEIS/
OEIS, which was published on May 11, 2012. The HSTT DEIS/OEIS is posted
on NMFS' Web site: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. NMFS intends to adopt the Navy's final
HSTT EIS/OEIS (FEIS/OEIS), if adequate and appropriate. Currently, we
believe that the adoption of the Navy's HSTT FEIS/OEIS will allow NMFS
to meet its responsibilities under NEPA for the issuance of regulations
and LOAs for HSTT. If the Navy's HSTT FEIS/OEIS is deemed inadequate,
NMFS would supplement the existing analysis to ensure that we comply
with NEPA prior to the issuance of the final rule or LOA.
Classification
The Office of Management and Budget has determined that this
proposed rule is not significant for purposes of Executive Order 12866.
Pursuant to the Regulatory Flexibility Act (RFA), 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
proposed rule, if adopted, would not have a significant economic impact
on a substantial number of small entities. The RFA 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.
605 (b), that the action will not have a significant economic impact on
a substantial number of small entities. The Navy is the sole entity
that would be affected by this rulemaking, and the Navy is not a small
governmental jurisdiction, small organization, or small business, as
defined by the RFA. Any requirements imposed by an LOA issued pursuant
to these regulations, and any monitoring or reporting requirements
imposed by these regulations, would be applicable only to the Navy.
NMFS does not expect the issuance of these regulations or the
associated LOAs to result in any impacts to small entities pursuant to
the RFA. 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 218
Exports, Fish, Imports, Incidental take, Indians, Labeling, Marine
mammals, Navy, Penalties, Reporting and recordkeeping requirements,
Seafood, Sonar, Transportation.
Dated: January 23, 2013.
Alan D. Risenhoover,
Director, Office of Sustainable Fisheries, performing the functions and
duties of the Deputy Assistant Administrator for Regulatory Programs,
National Marine Fisheries Service.
For reasons set forth in the preamble, 50 CFR part 218 is proposed
to be amended amended as follows:
PART 218--REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE
MAMMALS
0
1. The authority citation for part 218 continues to read as follow:
Authority: 16 U.S.C. 1361 et seq.
0
2. Subpart H is added to part 218 to read as follows:
Subpart H--Taking and Importing Marine Mammals; U.S. Navy's Hawaii-
Southern California Training and Testing (HSTT)
Sec.
218.70 Specified activity and specified geographical region.
218.71 Effective dates and definitions.
218.72 Permissible methods of taking.
218.73 Prohibitions.
218.74 Mitigation.
218.75 Requirements for monitoring and reporting.
218.76 Applications for Letters of Authorization
218.77 Letters of Authorization.
218.78 Renewal of Letters of Authorization and Adaptive Management.
218.79 Modifications to Letters of Authorization
Subpart H--Taking and Importing Marine Mammals; U.S. Navy's Hawaii-
Southern California Training and Testing (HSTT)
Sec. 218.70 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 occurs 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 HSTT Study Area, which is comprised of established
operating and warning areas across the north-central Pacific Ocean,
from Southern California west to Hawaii and the International Date Line
(see Figure 1-1 in the Navy's application). The Study Area includes
three existing range complexes: the Southern California (SOCAL) Range
Complex, Hawaii Range Complex
[[Page 7041]]
(HRC), and Silver Strand Training Complex (SSTC). In addition, the
Study Area also includes Navy pierside locations where sonar
maintenance and testing occurs within the Study Area, and areas on the
high seas that are not part of the range complexes, where training and
testing may occur during vessel transit.
(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) Non-impulsive Sources Used During Training:
(i) Mid-frequency (MF) Source Classes:
(A) MF1--an average of 11,588 hours per year.
(B) MF1K--an average of 88 hours per year.
(C) MF2--an average of 3,060 hours per year.
(D) MF2K--an average of 34 hours per year.
(E) MF3--an average of 2,336 hours per year.
(F) MF4--an average of 888 hours per year.
(G) MF5--an average of 13,718 items per year.
(H) MF11--an average of 1,120 hours per year.
(I) MF12--an average of 1,094 hours per year.
(ii) High-frequency (HF) and Very High-frequency (VHF) Source
Classes:
(A) HF1--an average of 1,754 hours per year.
(B) HF4--an average of 4,848 hours per year.
(iii) Anti-Submarine Warfare (ASW) Source Classes:
(A) ASW1--an average of 224 hours per year.
(B) ASW2--an average of 1,800 items per year.
(C) ASW3--an average of 16,561 hours per year.
(D) ASW4--an average of 1,540 items per year.
(iv) Torpedoes (TORP) Source Classes:
(A) TORP1--an average of 170 items per year.
(B) TORP2--an average of 400 items per year.
(2) Non-impulsive Sources Used During Testing:
(i) Low-frequency (LF) Source Classes:
(A) LF4--an average of 52 hours per year.
(B) LF5--an average of 2,160 hours per year.
(C) LF6--an average of 192 hours per year.
(ii) Mid-frequency (MF):
(A) MF1--an average of 180 hours per year.
(B) MF1K--an average of 18 hours per year.
(C) MF2--an average of 84 hours per year.
(D) MF3--an average of 392 hours per year.
(E) MF4--an average of 693 hours per year.
(F) MF5--an average of 5,024 items per year.
(G) MF6--an average of 540 items per year.
(H) MF8--an average of 2 hours per year.
(I) MF9--an average of 3,039 hours per year.
(J) MF10--an average of 35 hours per year.
(K) MF12--an average of 336 hours per year.
(iii) High-frequency (HF) and Very High-frequency (VHF):
(A) HF1--an average of 1,025 hours per year.
(B) HF3--an average of 273 hours per year.
(C) HF4--an average of 1,336 hours per year.
(D) HF5--an average of 1,094 hours per year.
(E) HF6--an average of 3,460 hours per year.
(iv) ASW:
(A) ASW1--an average of 224 hours per year.
(B) ASW2--an average of 2,260 items per year.
(C) ASW2H--an average of 255 hours per year.
(D) ASW3--an average of 1,278 hours per year.
(E) ASW4--an average of 477 items per year.
(v) TORP:
(A) TORP1--an average of 701 items per year.
(B) TORP2--an average of 732 items per year.
(vi) Acoustic Modems (M):
(A) M3--an average of 4,995 hours per year.
(vii) Swimmer Detection Sonar (SD):
(A) SD1--an average of 38 hours per year.
(viii) Airguns (AG):
(A) AG--an average of 5 airgun uses per year.
(ix) Synthetic Aperture Sonar (SAS):
(A) SAS1--an average of 2,700 hours per year.
(B) SAS2--an average of 4,956 hours per year.
(C) SAS3--an average of 3,360 hours per year.
(3) Annual Number of Impulsive Source Detonations During Training:
(i) Explosive Classes:
(A) E1 (0.1 to 0.25 lb NEW)--an average of 19,840 detonations per
year.
(B) E2 (1.26 to 0.5 lb NEW)--an average of 1,044 detonations per
year.
(C) E3 (0.6 to 2.5 lb NEW)--an average of 3,020 detonations per
year.
(D) E4 (>2.5 to 5 lb NEW)--an average of 668 detonations per year.
(E) E5 (>5 to 10 lb NEW)--an average of 8,154 detonations per year.
(F) E6 (>10 to 20 lb NEW)--an average of 538 detonations per year.
(G) E7 (>20 to 60 lb NEW)--an average of 407 detonations per year.
(H) E8 (>60 to 100 lb NEW)--an average of 64 detonations per year.
(I) E9 (>100 to 250 lb NEW)--an average of 16 detonations per year.
(J) E10 (>250 to 500 lb NEW)--an average of 19 detonations per
year.
(K) E11 (>500 to 650 lb NEW)--an average of 8 detonations per year.
(L) E12 (>650 to 1,000 lb NEW)--an average of 224 detonations per
year.
(M) E13 (>1,000 to 1,740 lb NEW)--an average of 9 detonations per
year.
(ii) [Reserved]
(4) Impulsive Source Detonations During Testing:
(i) Explosive Classes:
(A) E1 (0.1 to 0.25 lb NEW)--an average of 14,501 detonations per
year.
(B) E2 (0.26 to 0.5 lb NEW)--an average of 0 detonations per year.
(C) E3 (0.6 to 2.5 lb NEW)--an average of 2,990 detonations per
year.
(D) E4 (>2.5 to 5 lb NEW)--an average of 753 detonations per year.
(E) E5 (>5 to 10 lb NEW)--an average of 202 detonations per year.
(F) E6 (>10 to 20 lb NEW)--an average of 37 detonations per year.
(G) E7 (>20 to 60 lb NEW)--an average of 21 detonations per year.
(H) E8 (>60 to 100 lb NEW)--an average of 12 detonations per year.
(I) E9 (>100 to 250 lb NEW)--an average of 0 detonations per year.
(J) E10 (>250 to 500 lb NEW)--an average of 31 detonations per
year.
(K) E11 (>500 to 650 lb NEW)--an average of 14 detonations per
year.
(L) E12 (>650 to 1,000 lb NEW)--an average of 0 detonations per
year.
(M) E13 (>1,000 to 1,740 lb NEW)--an average of 0 detonations per
year.
(ii) [Reserved]
Sec. 218.71 Effective dates and definitions.
(a) Regulations are effective January 25, 2013 through Janaury 25,
2018.
(b) The following definitions are utilized in these regulations:
(1) Uncommon Stranding Event (USE)--A stranding event that takes
place during a major training exercise (MTE) 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 Sec.
218.71(b)(1)(ii) found dead or live on shore within a 2-day period and
[[Page 7042]]
occurring within 30 miles of one another.
(ii) A single individual or mother/calf pair of any of the
following marine mammals of concern: beaked whale of any species, Kogia
spp., Risso's dolphin, melon-headed whale, pilot whale, humpback whale,
sperm whale, blue whale, fin whale, sei whale, or monk seal.
(iii) A group of two or more cetaceans of any species exhibiting
indicators of distress.
(2) Shutdown--The cessation of MFAS/HFAS operation or detonation of
explosives within 14 nautical miles of any live, in the water, animal
involved in a USE.
Sec. 218.72 Permissible methods of taking.
(a) Under Letters of Authorization (LOAs) issued pursuant to Sec.
218.77, the Holder of the Letter of Authorization may incidentally, but
not intentionally, take marine mammals within the area described in
Sec. 218.70, provided the activity is in compliance with all terms,
conditions, and requirements of these regulations and the appropriate
LOA.
(b) The activities identified in Sec. 218.70(c) must be conducted
in a manner that minimizes, to the greatest extent practicable, any
adverse impacts on marine mammals and their habitat.
(c) The incidental take of marine mammals under the activities
identified in Sec. 218.70(c) is limited to the following species, by
the identified method of take and the indicated number of times:
(1) Level B Harassment for all Training Activities:
(i) Mysticetes:
(A) Blue whale (Balaenoptera musculus)--21,559 (an average of 4,312
per year).
(B) Bryde's whale (Balaenoptera edeni)--1,197 (an average of 240
per year).
(C) Fin whale (Balaenoptera physalus)--8,531 (an average of 1,707
per year).
(D) Gray whale (Eschrichtius robustus)--47,800 (an average of 9,560
per year).
(E) Humpback whale (Megaptera novaeangliae)--46,365 (an average of
9,273 per year).
(F) Minke whale (Balaenoptera acutorostrata)--4,030 (an average of
806 per year).
(G) Sei whale (Balaenoptera borealis)--2,996 (an average of 600 per
year).
(ii) Odontocetes:
(A) Baird's beaked whale (Berardius bairdii)--22,100 (an average of
4,420 per year).
(B) Blainville's beaked whale (Mesoplodon densirostris)--48,172 (an
average of 10,316 per year).
(C) Bottlenose dolphin (Tursiops truncatus)--158,590 (an average of
32,302 per year).
(D) Cuvier's beaked whale (Ziphius cavirostris)--314,790 (an
average of 66,246 per year).
(E) Dwarf sperm whale (Kogia sima)--101,291 (an average of 22,359
per year).
(F) Dall's porpoise (Phocoenoidea dalli)--184,455 (an average of
36,891 per year).
(G) False killer whale (Pseudorca crassidens), Hawaii Insular--220
(an average of 49 per year).
(H) False killer whale (Pseudorca crassidens)--2,892 (an average of
657 per year).
(I) Fraser's dolphin (Lagenodelphis hosei)--8,809 (an average of
2,009 per year).
(J) Killer whale (Orcinus orca)--2,427 (an average of 503 per
year).
(K) Kogia spp.--64,715 (an average of 12,943 per year).
(L) Long-beaked common dolphin (Delphinus capensis)--365,565 (an
average of 73,113 per year).
(M) Longman's beaked whale (Indopacetus pacificus)--17,296 (an
average of 3,666 per year).
(N) Melon-headed whale (Peponocephala electra)--6,733 (an average
of 1,511 per year).
(O) Mesoplodon beaked whales--9,970 (an average of 1,994 per year).
(P) Northern right whale dolphin (Lissodelphis borealis)--257,980
(an average of 51,596 per year).
(Q) Pacific white-sided dolphin (Lagenorhynchus obliquidens)--
192,335 (an average of 38,467 per year).
(R) Pantropical spotted dolphin (Stenella attenuata)--48,429 (an
average of 10,887 per year).
(S) Pygmy killer whale (Feresa attenuata)--2,603 (an average of 571
per year).
(T) Pygmy sperm whale (Kogia breviceps)--1,093 (an average of 229
per year).
(U) Risso's dolphin (Grampus griseus)--437,707 (an average of
87,649 per year).
(V) Rough-toothed dolphin (Steno bredanensis)--22,765 (an average
of 5,131 per year).
(W) Short-beaked common dolphin (Delphinus delphis)--4,996,410 (an
average of 999,282 per year).
(X) Short-finned pilot whale (Globicephala macrorhynchus)--42,300
(an average of 9,458 per year).
(Y) Sperm whale (Physeter macrocephalus)--15,920 (an average of
3,332 per year).
(Z) Spinner dolphin (Stenella longirostris)--11,060 (an average of
2,212 per year).
(AA) Striped dolphin (Stenella coerulealba)--33,147 (an average of
7,043 per year).
(iii) Pinnipeds:
(A) California sea lion (Zalophus californianus)--634,805 (an
average of 126,961 per year).
(B) Guadalupe fur seal (Arctocephalus townsendi)--13,014 (an
average of 2,603 per year).
(C) Harbor seal (Phoca vitulina)--29,530 (an average of 5,906 per
year).
(D) Hawaiian monk seal (Monachus schauinslandi)--6,334 (an average
of 1,292 per year).
(E) Northern elephant seal (Mirounga angustirostris)--112,580 (an
average of 22,516 per year).
(F) Northern fur seal (Callorhinus ursinus)--100,415 (an average of
20,083 per year).
(2) Level A Harassment for all Training Activities:
(i) Mysticetes:
(A) Gray whale (Eschrichtius robustus)--10 (an average of 2 per
year).
(B) [Reserved].
(ii) Odontocetes:
(A) Dwarf sperm whale (Kogia sima)--214 (an average of 46 per
year).
(B) Dall's porpoise (Phocoenoidea dalli)--235 (an average of 47 per
year).
(C) Kogia spp.--165 (an average of 33 per year).
(D) Long-beaked common dolphin (Delphinus capensis)--10 (an average
of 2 per year).
(E) Northern right whale dolphin (Lissodelphis borealis)--5 (an
average of 1 per year).
(F) Pacific white-sided dolphin (Lagenorhynchus obliquidens)--5 (an
average of 1 per year).
(G) Risso's dolphin (Grampus griseus)--5 (an average of 1 per
year).
(H) Short-beaked common dolphin (Delphinus delphis)--350 (an
average of 70 per year).
(iii) Pinnipeds:
(A) California sea lion (Zalophus californianus)--125 (an average
of 25 per year).
(B) Harbor seal (Phoca vitulina)--55 (an average of 11 per year).
(C) Northern elephant seal (Mirounga angustirostris)--110 (an
average of 22 per year).
(D) Northern fur seal (Callorhinus ursinus)--25 (an average of 5
per year).
(3) Mortality for all Training Activities:
(i) No more than 35 mortalities (7 per year) applicable to any
small odontocete or pinniped species from an impulse source.
(ii) No more than 10 beaked whale mortalities (2 per year).
(iii) No more than 12 large whale mortalities (no more than 4 in
any given year) from vessel strike.
[[Page 7043]]
(4) Level B Harassment for all Testing Activities:
(i) Mysticetes:
(A) Blue whale (Balaenoptera musculus)--2,140 (an average of 428
per year).
(B) Bryde's whale (Balaenoptera edeni)--90 (an average of 18 per
year).
(C) Fin whale (Balaenoptera physalus)--1,125 (an average of 225 per
year).
(D) Gray whale (Eschrichtius robustus)--12,850 (an average of 2,570
per year).
(E) Humpback whale (Megaptera novaeangliae)--4,605 (an average of
921 per year).
(F) Minke whale (Balaenoptera acutorostrata)--395 (an average of 79
per year).
(G) Sei whale (Balaenoptera borealis)--255 (an average of 51 per
year).
(ii) Odontocetes:
(A) Baird's beaked whale (Berardius bairdii)--5,225 (an average of
1,045 per year).
(B) Blainville's beaked whale (Mesoplodon densirostris)--4,800 (an
average of 960 per year).
(C) Bottlenose dolphin (Tursiops truncatus)--17,565 (an average of
3,513 per year).
(D) Cuvier's beaked whale (Ziphius cavirostris)--34,340 (an average
of 6,868 per year).
(E) Dwarf sperm whale (Kogia sima)--11,880 (an average of 2,376 per
year).
(F) Dall's porpoise (Phocoenoidea dalli)--26,075 (an average of
5,215 per year).
(G) False killer whale (Pseudorca crassidens), Hawaii Insular--20
(an average of 4 per year).
(H) False killer whale (Pseudorca crassidens)--255 (an average of
51 per year).
(I) Fraser's dolphin (Lagenodelphis hosei)--225 (an average of 45
per year).
(J) Killer whale (Orcinus orca)--335 (an average of 67 per year).
(K) Kogia spp.--6,160 (an average of 1,232 per year).
(L) Long-beaked common dolphin (Delphinus capensis)--239,255 (an
average of 47,851 per year).
(M) Longman's beaked whale (Indopacetus pacificus)--2,180 (an
average of 436 per year).
(N) Melon-headed whale (Peponocephala electra)--620 (an average of
124 per year).
(O) Mesoplodon beaked whales--1,725 (an average of 345 per year).
(P) Northern right whale dolphin (Lissodelphis borealis)--28,645
(an average of 5,729 per year).
(Q) Pacific white-sided dolphin (Lagenorhynchus obliquidens)--
24,620 (an average of 4,924 per year).
(R) Pantropical spotted dolphin (Stenella attenuata)--3,425 (an
average of 685 per year).
(S) Pygmy killer whale (Feresa attenuata)--305 (an average of 61
per year).
(T) Pygmy sperm whale (Kogia breviceps)--585 (an average of 117 per
year).
(U) Risso's dolphin (Grampus griseus)--44,260 (an average of 8,852
per year).
(V) Rough-toothed dolphin (Steno bredanensis)--2,050 (an average of
410 per year).
(W) Short-beaked common dolphin (Delphinus delphis)--613,740 (an
average of 122,748 per year).
(X) Short-finned pilot whale (Globicephala macrorhynchus)--4,380
(an average of 876 per year).
(Y) Sperm whale (Physeter macrocephalus)--1,315 (an average of 263
per year).
(Z) Spinner dolphin (Stenella longirostris)--835 (an average of 167
per year).
(AA) Striped dolphin (Stenella coerulealba)--6,335 (an average of
1,267 per year).
(iii) Pinnipeds:
(A) California sea lion (Zalophus californianus)--65,190 (an
average of 13,038 per year).
(B) Guadalupe fur seal (Arctocephalus townsendi)--1,345 (an average
of 269 per year).
(C) Harbor seal (Phoca vitulina)--4,460 (an average of 892 per
year).
(D) Hawaiian monk seal (Monachus schauinslandi)--1,790 (an average
of 358 per year).
(E) Northern elephant seal (Mirounga angustirostris)--13,560 (an
average of 2,712 per year).
(F) Northern fur seal (Callorhinus ursinus)--5,440 (an average of
1,088 per year).
(5) Level A Harassment for all Testing Activities:
(i) Mysticetes:
(A) Gray whale (Eschrichtius robustus)--5 (an average of 1 per
year).
(B) [Reserved].
(ii) Odontocetes:
(A) Dwarf sperm whale (Kogia sima)--140 (an average of 28 per
year).
(B) Dall's porpoise (Phocoenoidea dalli)--160 (an average of 32 per
year).
(C) Kogia spp.--30 (an average of 6 per year).
(D) Long-beaked common dolphin (Delphinus capensis)--10 (an average
of 2 per year).
(E) Northern right whale dolphin (Lissodelphis borealis)--5 (an
average of 1 per year).
(F) Pacific white-sided dolphin (Lagenorhynchus obliquidens)--5 (an
average of 1 per year).
(G) Pantropical spotted dolphin (Stenella attenuata)--10 (an
average of 2 per year).
(H) Pygmy sperm whale (Kogia breviceps)--5 (an average of 1 per
year).
(I) Risso's dolphin (Grampus griseus)--5 (an average of 1 per
year).
(J) Short-beaked common dolphin (Delphinus delphis)--200 (an
average of 40 per year).
(K) Spinner dolphin (Stenella longirostris)--5 (an average of 1 per
year).
(L) Striped dolphin (Stenella coerulealba)--5 (an average of 1 per
year).
(iii) Pinnipeds:
(A) California sea lion (Zalophus californianus)--85 (an average of
17 per year).
(B) Harbor seal (Phoca vitulina)--15 (an average of 3 per year).
(C) Northern elephant seal (Mirounga angustirostris)--25 (an
average of 5 per year).
(D) Northern fur seal (Callorhinus ursinus)--15 (an average of 3
per year).
(3) Mortality for all Testing Activities:
(i) No more than 95 mortalities (an average of 19 per year)
applicable to any small odontocete or pinniped species from an impulse
source.
(ii) No more than 3 large whale mortalities (no more than 2 in any
given year) from vessel strike.
Sec. 218.73 Prohibitions.
Notwithstanding takings contemplated in Sec. 218.72 and authorized
by an LOA issued under Sec. Sec. 216.106 and 218.77 of this chapter,
no person in connection with the activities described in Sec. 218.70
may:
(a) Take any marine mammal not specified in Sec. 218.72(c);
(b) Take any marine mammal specified in Sec. 218.72(c) other than
by incidental take as specified in Sec. 218.72(c);
(c) Take a marine mammal specified in Sec. 218.72(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 an LOA issued under Sec. Sec.
216.106 and 218.77.
Sec. 218.74 Mitigation.
(a) When conducting training and testing activities, as identified
in Sec. 218.70, the mitigation measures contained in the LOA issued
under Sec. Sec. 216.106 and 218.77 of this chapter must be
implemented. These mitigation measures include, but are not limited to:
(1) Lookouts. The following are protective measures concerning the
use of lookouts.
[[Page 7044]]
(i) Lookouts positioned on surface ships will be dedicated solely
to diligent observation of the air and surface of the water. Their
observation objectives will include, but are not limited to, detecting
the presence of biological resources and recreational or fishing boats,
observing buffer zones, and monitoring for vessel and personnel safety
concerns.
(ii) Lookouts positioned in aircraft or on boats will, to the
maximum extent practicable and consistent with aircraft and boat safety
and training and testing requirements, comply with the observation
objectives described above in Sec. 218.74 (a)(1)(i).
(iii) Lookout measures for non-impulsive sound:
(A) With the exception of vessels less than 65 ft (20 m) in length
and the Littoral Combat Ship (and similar vessels which are minimally
manned), ships using low-frequency or hull-mounted mid-frequency active
sonar sources associated with anti-submarine warfare and mine warfare
activities at sea will have two lookouts at the forward position of the
vessel. For the purposes of this rule, low-frequency active sonar does
not include surface towed array surveillance system low-frequency
active sonar.
(B) While using low-frequency or hull-mounted mid-frequency active
sonar sources associated with anti-submarine warfare and mine warfare
activities at sea, vessels less than 65 ft (20 m) in length and the
Littoral Combat Ship (and similar vessels which are minimally manned)
will have one lookout at the forward position of the vessel due to
space and manning restrictions.
(C) Ships conducting active sonar activities while moored or at
anchor (including pierside testing or maintenance) will maintain one
lookout.
(D) Ships or aircraft conducting non-hull-mounted mid-frequency
active sonar, such as helicopter dipping sonar systems, will maintain
one lookout.
(E) Surface ships or aircraft conducting high-frequency or non-
hull-mounted mid-frequency active sonar activities associated with
anti-submarine warfare and mine warfare activities at sea will have one
lookout.
(iii) Lookout measures for explosives and impulsive sound:
(A) Aircraft conducting IEER sonobuoy activities will have one
lookout.
(B) Surface vessels conducting anti-swimmer grenade activities will
have one lookout.
(C) During general mine countermeasure and neutralization
activities using up to a 500-lb net explosive weight detonation (bin
E10 and below), vessels greater than 200 ft will have two lookouts,
while vessels less than 200 ft will have one lookout.
(D) General mine countermeasure and neutralization activities using
a 501 to 650-lb net explosive weight detonation (bin E11), will have
two lookouts. One lookout will be positioned in an aircraft and one in
a support vessel.
(E) Mine neutralization activities involving diver-placed charges
using up to a 20-lb net explosive weight detonation will have one
lookout.
(F) Mine neutralization activities involving diver-placed charges
using a 21 to 100-lb net explosive weight detonation (E8) will have two
lookouts. One lookout will be positioned in each of the two support
vessels. If aircraft are used, the pilot or member of the aircrew will
serve as an additional lookout. The divers placing the charges on mines
will report all marine mammal sightings to their dive support vessel.
(G) When mine neutralization activities using diver-placed charges
with up to a 20-lb net explosive weight detonation (bin E6) are
conducted with a time-delay firing device, four lookouts will be used.
Two lookouts will be positioned in each of two small rigid hull
inflatable boats. When aircraft are used, the pilot or member of the
aircrew will serve as an additional lookout. The divers placing the
charges on mines will report all marine mammal sightings to their dive
support vessel.
(H) Surface vessels conducting line charge testing will have one
lookout.
(I) Surface vessels or aircraft conducting small- and medium-
caliber gunnery exercises will have one lookout.
(J) Surface vessels or aircraft conducting large-caliber gunnery
exercises will have one lookout.
(K) Surface vessels or aircraft conducting missile exercises
against surface targets will have one lookout.
(L) Aircraft conducting bombing exercises will have one lookout.
(M) During explosive torpedo testing, one lookout will be used and
positioned in an aircraft.
(N) During sinking exercises, two lookouts will be used. One
lookout will be positioned in an aircraft and one on a surface vessel.
(O) Each surface vessel supporting at-sea explosive testing will
have at least one lookout.
(P) During pile driving, one lookout will be used and positioned on
the platform that will maximize the potential for marine mammal
sightings (e.g., the shore, an elevated causeway, or on a ship).
(Q) Surface vessels conducting explosive and non-explosive large-
caliber gunnery exercises will have one lookout. This may be the same
lookout used during large-caliber gunnery exercises with a surface
target.
(iv) Lookout measures for physical strike and disturbance:
(A) While underway, surface ships will have at least one lookout.
(B) During activities using towed in-water devices, one lookout
will be used.
(C) Activities involving non-explosive practice munitions (e.g.,
small-, medium-, and large-caliber gunnery exercises) using a surface
target will have one lookout.
(D) During activities involving non-explosive bombing exercises,
one lookout will be used.
(2) Mitigation Zones. The following are protective measures
concerning the implementation of mitigation zones.
(i) Mitigation zones will be measured as the radius from a source
and represent a distance to be monitored.
(ii) Visual detections of marine mammals within a mitigation zone
will be communicated immediately to a watch station for information
dissemination and appropriate action.
(iii) Mitigation zones for non-impulsive sound: \1\
---------------------------------------------------------------------------
\1\ The mitigation zone would be 200 yd for low-frequency non-
hull mounted sources in bin LF4.
---------------------------------------------------------------------------
(A) When marine mammals are detected by any means, the Navy shall
ensure that low-frequency and hull-mounted mid-frequency active sonar
transmission levels are limited to at least 6 dB below normal operating
levels if any detected marine mammals are within 1,000 yd (914 m) of
the sonar dome (the bow).
(B) The Navy shall ensure that low-frequency and hull-mounted mid-
frequency active sonar transmissions are limited to at least 10 dB
below the equipment's normal operating level if any detected marine
mammals are within 500 yd (457 m) of the sonar dome.
(C) The Navy shall ensure that low-frequency and hull-mounted mid-
frequency active sonar transmissions are ceased if any detected marine
mammals are within 200 yd (183 m) of the sonar dome. 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 yd beyond the location of the last detection.
(D) When marine mammals are detected by any means, the Navy shall
ensure that high-frequency and non-hull-mounted mid-frequency active
sonar transmission levels are ceased if
[[Page 7045]]
any detected marine mammals are within 200 yd (183 m) of the source.
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 yd beyond the location of the last detection.
(E) 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.
(F) Prior to start up or restart of active sonar, operators shall
check that the mitigation zone radius around the sound source is clear
of marine mammals.
(G) Generally, the Navy shall operate sonar at the lowest
practicable level, not to exceed 235 dB, except as required to meet
tactical training objectives.
(iv) Mitigation zones for explosive and impulsive sound:
(A) A mitigation zone with a radius of 600 yd (549 m) shall be
established for IEER sonobuoys (bin E4).
(B) A mitigation zone with a radius of 350 yd (320 m) shall be
established for explosive sonobuoys using 0.6 to 2.5 lb net explosive
weight (bin E3).
(C) A mitigation zone with a radius of 200 yd (183 m) shall be
established for anti-swimmer grenades (bin E2).
(D) A mitigation zone ranging from 350 yd (320 m) to 850 yd (777
m), dependent on charge size, shall be established for mine
countermeasure and neutralization activities using positive control
firing devices. Mitigation zone distances are specified for charge size
in Table 11-2 of the Navy's application.
(E) A mitigation zone with a radius of 1,000 yd (915 m) shall be
established for mine neutralization diver placed mines using time-delay
firing devices (bin E6).
(F) A mitigation zone with a radius of 900 yd (823 m) shall be
established for ordnance testing (line charge testing) (bin E4).
(G) A mitigation zone with a radius of 200 yd (183 m) shall be
established for small- and medium-caliber gunnery exercises with a
surface target (bin E2).
(H) A mitigation zone with a radius of 600 yd (549 m) shall be
established for large-caliber gunnery exercises with a surface target
(bin E5).
(I) A mitigation zone with a radius of 900 yd (823 m) shall be
established for missile exercises with up to 250 lb net explosive
weight and a surface target (bin E9).
(J) A mitigation zone with a radius of 2,000 yd (1.8 km) shall be
established for missile exercises with 251 to 500 lb net explosive
weight and a surface target (E10).
(K) A mitigation zone with a radius of 2,500 yd (2.3 km) shall be
established for bombing exercises (bin E12).
(L) A mitigation zone with a radius of 2,100 yd (1.9 km) shall be
established for torpedo (explosive) testing (bin E11).
(M) A mitigation zone with a radius of 2.5 nautical miles shall be
established for sinking exercises (bin E12).
(N) A mitigation zone with a radius of 1,600 yd (1.4 km) shall be
established for at-sea explosive testing (bin E5).
(O) A mitigation zone with a radius of 60 yd (55 m) shall be
established for elevated causeway system pile driving.
(v) Mitigation zones for vessels and in-water devices:
(A) A mitigation zone of 500 yd (457 m) for observed whales and 200
yd (183 m) for all other marine mammals (except bow riding dolphins)
shall be established for all vessel movement, providing it is safe to
do so.
(B) A mitigation zone of 250 yd (229 m) shall be established for
all towed in-water devices, providing it is safe to do so.
(vi) Mitigation zones for non-explosive practice munitions:
(A) A mitigation zone of 200 yd (183 m) shall be established for
small, medium, and large caliber gunnery exercises using a surface
target.
(B) A mitigation zone of 1,000 yd (914 m) shall be established for
bombing exercises.
(vii) Mitigation zones for the use of Navy sea lions:
(A) If a monk seal is seen approaching or within 100 m of a Navy
sea lion, the handler will hold the Navy sea lion in the boat or recall
the Navy sea lion immediately if it has already been released.
(3) Humpback Whale Cautionary Area
(i) The Navy will maintain a 5-km (3.1-mi) buffer zone between
December 15 and April 15 where conducting exercises will require
authorization by the Commander, U.S. Pacific Fleet (CPF).
(ii) If authorized, the CPF will provide specific direction on
required mitigation prior to operational units transiting to and
training in the area.
(iii) The Navy will provide NMFS with advance notification of any
mid-frequency active sonar training and testing activities in the
humpback whale cautionary area.
(4) Stranding Response Plan
(i) The Navy shall abide by the letter of the ``Stranding Response
Plan for Major Navy Training Exercises in the HSTT Study Area,'' to
include the following measures:
(A) Shutdown Procedures--When an Uncommon Stranding Event (USE--
defined in Sec. 218.71(b)(1)) occurs during a Major Training Exercise
(MTE) in the HSTT Study Area, the Navy shall implement the procedures
described below.
(1) The Navy shall implement a shutdown (as defined Sec.
218.71(b)(2)) when advised by a NMFS Office of Protected Resources
Headquarters Senior Official designated in the HSTT Study Area
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 the 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 shall 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 security considerations allow. The Navy shall 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 behavior (if alive), and
photo or video (if available). Based on the information provided, NFMS
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 shall
coordinate (including an investigation of other potential anthropogenic
stressors in the area) to determine if the proximity of mid-frequency
active sonar training activities or explosive detonations, though
farther than 14 nautical miles from the distressed animal(s), is likely
contributing to the animals' refusal to return to the open water. If
so, NMFS and the Navy will further coordinate to determine what
measures are necessary to improve the probability that the animals will
return
[[Page 7046]]
to open water and implement those measures as appropriate.
(B) Within 72 hours of NMFS notifying the Navy of the presence of a
USE, the Navy shall provide available information to NMFS (per the HSTT
Study Area Communication Protocol) regarding the location, number and
types of acoustic/explosive sources, direction and speed of units using
mid-frequency active sonar, and marine mammal sightings information
associated with training activities occurring within 80 nautical miles
(148 km) and 72 hours prior to the USE event. Information not initially
available regarding the 80-nautical miles (148-km), 72-hour 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.
(b) [Reserved]
Sec. 218.75 Requirements for monitoring and reporting.
(a) As outlined in the HSTT Study Area Stranding Communication
Plan, the Holder of the Authorization must notify NMFS immediately (or
as soon as operational security considerations allow) if the specified
activity identified in Sec. 218.70 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. 218.71.
(b) The Holder of the LOA must conduct all monitoring and required
reporting under the LOA, including abiding by the HSTT Monitoring Plan.
(c) General Notification of Injured or Dead Marine Mammals--Navy
personnel shall ensure that NMFS (regional stranding coordinator) is
notified immediately (or as soon as operational security considerations
allow) if an injured or dead marine mammal is found during or shortly
after, and in the vicinity of, a Navy training or testing activity
utilizing mid- or high-frequency active sonar, or underwater explosive
detonations. The Navy shall 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
Navy shall consult the Stranding Response Plan to obtain more specific
reporting requirements for specific circumstances.
(d) Annual HSTT Monitoring Plan Report--The Navy shall submit an
annual report describing the implementation and results (through
November of the same year) of the HSTT Monitoring Plan, described in
Sec. 218.75. Data collection methods will be standardized across range
complexes and study areas to allow for comparison in different
geographic locations. Although additional information will be gathered,
the protected species observers collecting marine mammal data pursuant
to the HSTT Monitoring Plan shall, at a minimum, provide the same
marine mammal observation data required in Sec. 218.75. The HSTT
Monitoring Plan may be provided to NMFS within a larger report that
includes the required Monitoring Plan reports from multiple range
complexes and study areas.
(e) Annual HSTT Exercise Report--The Navy shall submit an annual
HSTT Exercise Report. This report shall contain information identified
in subsections Sec. 218.75 (e)(1-5).
(1) MFAS/HFAS Major Training Exercises--This section shall contain
the following information for Major Training Exercises (MTEs, which
include RIMPAC, USWEX, and Multi Strike Group) conducted in the HRC:
(i) Exercise Information (for each MTE):
(A) Exercise designator.
(B) Date that exercise began and ended.
(C) Location.
(D) Number and types of active sources used in the exercise.
(E) Number and types of passive acoustic sources used in exercise.
(F) Number and types of vessels, aircraft, etc., participating in
exercise.
(G) Total hours of observation by watchstanders.
(H) Total hours of all active sonar source operation.
(I) Total hours of each active sonar source bin.
(J) Wave height (high, low, and average during exercise).
(ii) Individual marine mammal sighting info (for each sighting in
each MTE).
(A) Location of sighting.
(B) Species (if not possible, indication of whale/dolphin/
pinniped).
(C) Number of individuals.
(D) Calves observed (y/n).
(E) Initial Detection Sensor.
(F) Indication of specific type of platform observation made from
(including, for example, what type of surface vessel, i.e., FFG, DDG,
or CG).
(G) Length of time observers maintained visual contact with marine
mammal.
(H) Wave height (in feet).
(I) Visibility.
(J) Sonar source in use (y/n).
(K) Indication of whether animal is <200 yd, 200 to 500 yd, 500 to
1,000 yd, 1,000 to 2,000 yd, or >2,000 yd from sonar source in
paragraph (f)(1)(ii)(J) of this section.
(L) Mitigation Implementation--Whether operation of sonar sensor
was delayed, or sonar was powered or shut down, and how long the delay
was.
(M) If source in use (see paragraph (f)(1)(ii)(J) of this section)
is hull-mounted, true bearing of animal from ship, true direction of
ship's travel, and estimation of animal's motion relative to ship
(opening, closing, parallel).
(N) Observed behavior. Watchstanders shall report, in plain
language and without trying to categorize in any way, the observed
behavior of the animals (such as animal closing to bow ride,
paralleling course/speed, floating on surface and not swimming, etc.).
(iii) An evaluation (based on data gathered during all of the MTEs)
of the effectiveness of mitigation measures designed to avoid exposing
animals to mid-frequency active sonar. This evaluation shall identify
the specific observations that support any conclusions the Navy reaches
about the effectiveness of the mitigation.
(2) ASW Summary. This section shall include the following
information as summarized from both MTEs and non-major training
exercises (i.e., unit-level exercises, such as TRACKEXs):
(i) Total annual hours of each sonar source bin.
(ii) Total hours (from December 15 through April 15) of hull-
mounted active sonar operation occurring in the dense humpback areas
plus a 5-km buffer, but not including the Pacific Missile Range
Facility.
(iii) Total estimated annual hours of hull-mounted active sonar
operation conducted in the Humpback Whale Cautionary area between
December 15 and April 15.
(iv) Cumulative Impact Report. To the extent practicable, the Navy,
in coordination with NMFS, shall develop and implement a method of
annually reporting non-major (i.e., other than RIMPAC, USWEX, or Multi-
Strike Group Exercises) training exercises utilizing hull-mounted
sonar. The report shall present an annual (and seasonal, where
practicable) depiction of non-major training exercises geographically
across the HSTT Study Area. The Navy shall include (in the HSTT annual
report) a brief annual progress update on the status of development
until an agreed-upon (with NMFS) method has been developed and
implemented.
(3) SINKEXs. This section shall include the following information
for each SINKEX completed that year:
(i) Exercise information (gathered for each SINKEX):
(A) Location.
[[Page 7047]]
(B) Date and time exercise began and ended.
(C) Total hours of observation by lookouts before, during, and
after exercise.
(D) Total number and types of explosive source bins detonated.
(E) Number and types of passive acoustic sources used in exercise.
(F) Total hours of passive acoustic search time.
(G) Number and types of vessels, aircraft, etc., participating in
exercise.
(H) Wave height in feet (high, low, and average during exercise).
(I) Narrative description of sensors and platforms utilized for
marine mammal detection and timeline illustrating how marine mammal
detection was conducted.
(ii) Individual marine mammal observation (by Navy lookouts)
information (gathered for each marine mammal sighting):
(A) Location of sighting.
(B) Species (if not possible, indicate whale, dolphin, or
pinniped).
(C) Number of individuals.
(D) Whether calves were observed.
(E) Initial detection sensor.
(F) Length of time observers maintained visual contact with marine
mammal.
(G) Wave height.
(H) Visibility.
(I) Whether sighting was before, during, or after detonations/
exercise, and how many minutes before or after.
(J) Distance of marine mammal from actual detonations (or target
spot if not yet detonated).
(K) Observed behavior--Lookouts will report, in plain language and
without trying to categorize in any way, the observed behavior of the
animal(s) (such as animal closing to bow ride, paralleling course/
speed, floating on surface and not swimming etc.), including speed and
direction.
(L) Resulting mitigation implementation--Indicate whether explosive
detonations were delayed, ceased, modified, or not modified due to
marine mammal presence and for how long.
(M) If observation occurs while explosives are detonating in the
water, indicate munition type in use at time of marine mammal
detection.
(4) IEER Summary. This section shall include an annual summary of
the following IEER information:
(i) Total number of IEER events conducted in the HSTT Study Area.
(ii) Total expended/detonated rounds (buoys).
(iii) Total number of self-scuttled IEER rounds.
(5) Explosives Summary--To the extent practicable, the Navy will
provide the information described below for all of their explosive
exercises. Until the Navy is able to report in full the information
below, they will provide an annual update on the Navy's explosive
tracking methods, including improvements from the previous year.
(i) Total annual number of each type of explosive exercises (of
those identified as part of the ``specified activity'' in this final
rule) conducted in the HSTT Study Area.
(ii) Total annual expended/detonated rounds (missiles, bombs, etc.)
for each explosive source bin.
(g) Sonar Exercise Notification--The Navy shall submit to the NMFS
Office of Protected Resources (specific contact information to be
provided in LOA) either an electronic (preferably) or verbal report
within fifteen calendar days after the completion of any major exercise
(RIMPAC, USWEX, or Multi Strike Group) indicating:
(1) Location of the exercise.
(2) Beginning and end dates of the exercise.
(3) Type of exercise (e.g., RIMPAC, USWEX, or Multi Strike Group).
(h) HSTT Study Area 5-yr Comprehensive Report. The Navy shall
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 annual reports are required (Annual HSTT Exercise
Reports and HSTT Monitoring Plan reports). This report will be
submitted at the end of the fourth year of the rule (November 2018),
covering activities that have occurred through June 1, 2018.
(i) Comprehensive National ASW Report. By June 2019, the Navy shall
submit a draft Comprehensive National Report that analyzes, compares,
and summarizes the active sonar data gathered (through January 1, 2019)
from the lookouts in accordance with the Monitoring Plans for HSTT,
AFTT, MITT, and NWTT.
(j) The Navy shall respond to NMFS' comments and requests for
additional information or clarification on the HSTT Comprehensive
Report, the draft National ASW report, the Annual HSTT Exercise Report,
or the Annual HSTT Monitoring Plan report (or the multi-Range Complex
Annual Monitoring Plan Report, if that is how the Navy chooses to
submit the information) if submitted within 3 months of receipt. These
reports will be considered final after the Navy has addressed NMFS'
comments or provided the requested information, or three months after
the submittal of the draft if NMFS does not comment by then.
Sec. 218.76 Applications for Letters of Authorization.
To incidentally take marine mammals pursuant to the regulations in
this subpart, the U.S. citizen (as defined by Sec. 216.106) conducting
the activity identified in Sec. 218.70(c) (the U.S. Navy) must apply
for and obtain either an initial LOA in accordance with Sec. 218.77 or
a renewal under Sec. 218.78.
Sec. 218.77 Letters of Authorization.
(a) An LOA, unless suspended or revoked, will be valid for a period
of time not to exceed the period of validity of this subpart.
(b) Each LOA 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 LOA 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. 218.78 Renewal of Letters of Authorization and Adaptive
Management.
(a) A Letter of Authorization issued under Sec. Sec. 216.106 and
218.77 for the activity identified in Sec. 218.70(c) will be renewed
based upon:
(1) Notification to NMFS that the activity described in the
application submitted under Sec. 218.78 will be undertaken and that
there will not be a substantial modification to the described work,
mitigation, or monitoring undertaken during the upcoming period of
validity;
(2) Timely receipt (by the dates indicated in these regulations) of
the monitoring reports required under Sec. 218.75(c-j); and
(3) A determination by the NMFS that the mitigation, monitoring,
and reporting measures required under Sec. 218.74 and the LOA issued
under Sec. Sec. 216.106 and 218.78, were undertaken and will be
undertaken during the upcoming period of validity of a renewed Letter
of Authorization.
(b) If a request for a renewal of an LOA issued under this Sec.
216.106 and Sec. 218.78 indicates that a substantial modification, as
determined by NMFS, to the described work, mitigation or monitoring
undertaken during the upcoming season will occur, NMFS will provide the
public a period of 30 days for review and comment on the request.
[[Page 7048]]
Review and comment on renewals of LOAs 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 these regulations or in the current LOA.
(c) A notice of issuance or denial of an LOA renewal will be
published in the Federal Register.
(d) NMFS, in response to new information and in consultation with
the Navy, may modify the mitigation or monitoring measures in
subsequent LOAs if doing so creates a reasonable likelihood of more
effectively accomplishing the goals of mitigation and monitoring. Below
are some of the possible sources of new data that could contribute to
the decision to modify the mitigation or monitoring measures:
(1) Results from the Navy's monitoring from the previous year
(either from the HSTT Study Area or other locations).
(2) Compiled results of Navy-funded research and development (R&D)
studies (presented pursuant to the ICMP (Sec. 218.75(d)).
(3) Results from specific stranding investigations (either from the
HSTT Study Area or other locations, and involving coincident mid- or
high-frequency active sonar or explosives training or not involving
coincident use).
(4) Results from the Long Term Prospective Study.
(5) Results from general marine mammal and sound research (funded
by the Navy (or otherwise)).
Sec. 216.79 Modifications to Letters of Authorization.
(a) Except as provided in paragraph (b) of this section, no
substantive modification (including withdrawal or suspension) to the
LOA by NMFS, issued pursuant to Sec. Sec. 216.106 and 218.77 of this
chapter 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 an LOA under
Sec. 218.78, without modification (except for the period of validity),
is not considered a substantive modification.
(b) If the Assistant Administrator determines that an emergency
exists that poses a significant risk to the well-being of the species
or stocks of marine mammals specified in Sec. 218.72(c), an LOA issued
pursuant to Sec. Sec. 216.106 and 218.77 of this chapter 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.
[FR Doc. 2013-01808 Filed 1-25-13; 11:15 am]
BILLING CODE 3510-22-P