Federal Register, Volume 80 Issue 106 (Wednesday, June 3, 2015)

[Federal Register Volume 80, Number 106 (Wednesday, June 3, 2015)]
[Proposed Rules]
[Pages 31738-31817]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-13038]

[[Page 31737]]

Vol. 80

Wednesday,

No. 106

June 3, 2015

Part IV

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 Northwest Training and Testing
Study Area; Proposed Rule

Federal Register / Vol. 80 , No. 106 / Wednesday, June 3, 2015 /
Proposed Rules

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 218

[Docket No. 140109018-5464-01]
RIN 0648-BD89

Takes of Marine Mammals Incidental to Specified Activities; U.S.
Navy Training and Testing Activities in the Northwest 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 Northwest Training and Testing
(NWTT) study area from November 2015 through November 2020. 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.
The Navy has also requested that NMFS authorize modifications to
watchstander requirements for observed behavior of marine mammals
during Major Training Events (MTEs) in the Hawaii-Southern California
Training and Testing (HSTT), Atlantic Fleet Training and Testing
(AFTT), Mariana Islands Training and Testing (MITT), and Gulf of Alaska
Training (GOA) study areas. Modifications to the Navy watchstander
requirements would require a revision to regulatory text in current
regulations governing the taking and importing of marine mammals during
testing and/or training activities in these study areas. There are no
MTEs associated with Navy training and testing activities in the NWTT
study area.

DATES: Comments and information must be received no later than July 17,
2015.

ADDRESSES: You may submit comments, identified by NOAA-NMFS-2015-0031,
by any of the following methods:
Electronic submissions: submit all electronic public
comments via the Federal eRulemaking Portal, Go to www.regulations.gov/#!docketDetail;D=NOAA-NMFS-2015-0031, click the ``Comment Now!'' icon,
complete the required fields, and enter or attach your comments.
Mail: Submit comments to Jolie Harrison, Chief, Permits
and Conservation Division, Office of Protected Resources, National
Marine Fisheries Service, 1315 East-West Highway, Silver Spring, MD
20910-3225.
Fax: (301) 713-0376; Attn: Jolie Harrison.
Instructions: Comments sent by any other method, to any other
address or individual, or received after the end of the comment period,
may not be considered by NMFS. All comments received are a part of the
public record and will generally be posted for public viewing on
www.regulations.gov without change. All personal identifying
information (e.g., name, address, etc.), confidential business
information, or otherwise sensitive information submitted voluntarily
by the sender will be publicly accessible. 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, or Adobe PDF file formats only.

FOR FURTHER INFORMATION CONTACT: John Fiorentino, Office of Protected
Resources, NMFS, (301) 427-8477.

SUPPLEMENTARY INFORMATION:

Availability

A copy of the Navy's LOA application, which contains a list of the
references used in this document, may be obtained by visiting the
internet at: http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm. The Navy also prepared a Draft Environmental Impact
Statement (DEIS)/Overseas Environmental Impact Statement (OEIS) to
assess the environmental impacts associated with ongoing and proposed
training and testing activities in the NWTT Study Area. The NWTT DEIS/
OEIS was released to the public on January 24, 2014 (79 FR 4158) for
review until April 15, 2014. On October 24, 2014 (79 FR 63610), the
Navy published a Notice of Intent (NOI) to prepare a Supplement to the
January 2014 NWTT DEIS/OEIS. The Supplement was released to the public
on December 19, 2014 (79 FR 75800) for review until February 2, 2015.
The Navy is the lead agency for the NWTT EIS/OEIS, and NMFS and the
U.S. Coast Guard are cooperating agencies pursuant to 40 CFR 1501.6 and
1508.5. The January 2014 NWTT DEIS/OEIS and the December 2014
Supplement, which contain a list of the references used in this
document, may be viewed at: http://www.nwtteis.com. 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) (Public Law
108-136) removed the ``small numbers'' and ``specified geographical
region'' limitations indicated above and amended the definition of
``harassment'' as it applies to a ``military readiness activity'' to
read as follows (section 3(18)(B) of the MMPA): ``(i) Any act that
injures or has the significant potential to injure a marine mammal or
marine mammal stock in the wild [Level A Harassment]; or (ii) any act
that disturbs or is likely to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of natural behavioral patterns,
including, but not limited to, migration, surfacing, nursing, breeding,
feeding, or sheltering, to a point where such behavioral patterns are
abandoned or significantly altered [Level B Harassment].''

Summary of Request

NWTT Proposed Rule

On December 18, 2013, NMFS received an application from the Navy
requesting two LOAs for the take of 26 species of marine mammals
incidental to Navy training and testing activities to be conducted in
the NWTT Study Area over 5 years. On September 26, 2014, the Navy
submitted a revised LOA application to reflect updates to exposure
estimates based on emergent

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changes to specific types of training activities. The revised
application also provided an update to the effects analysis for
Guadalupe fur seals (summarized in the Analysis of Guadalupe Fur Seal
Exposures section of this proposed rule) to more realistically reflect
potential impacts from offshore Navy training and testing events. On
November 7, 2014, the Navy submitted a revised LOA application to
address: (a) An inadvertent error in the recommended mitigation zone
for mine countermeasure and neutralization training events; (b) removal
of the time delay firing underwater explosive training activity; and
(c) correction or clarification of certain mitigation measures applied
to testing. On April 2, 2015, the Navy submitted a final revision to
the LOA application (hereinafter referred to as the LOA application) to
incorporate and update population density estimates for the Hood Canal
stock of harbor seals.
The Navy is requesting separate 5-year LOAs for training and
testing activities to be conducted from 2015 through 2020. The Study
Area includes the existing Northwest Training Range Complex, the
Keyport Range Complex, Carr Inlet Operations Area, Southeast Alaska
Acoustic Measurement Facility (SEAFAC), and Navy pierside locations
where sonar maintenance or testing may occur (see Figure 1-1 of the LOA
application for a map of the NWTT Study Area). The activities conducted
within the NWTT Study Area are classified as military readiness
activities. The Navy states that these activities may expose some of
the marine mammals present within the NWTT Study Area to sound from
underwater acoustic sources and explosives. The Navy is requesting
authorization to take 26 marine mammal species by Level B (behavioral)
harassment; 4 of those marine mammal species may be taken by injury
(Level A harassment).
The LOA application and the January 2014 NWTT DEIS/OEIS contain
proposed acoustic thresholds that were used to evaluate the Navy's AFTT
and HSTT activities. The thresholds are based on evaluation of recent
scientific studies; a detailed explanation of how they were derived is
provided in the Criteria and Thresholds for Navy Acoustic Effects
Analysis Technical Report (Finneran and Jenkins, 2012). NMFS is
currently updating and revising all of its acoustic thresholds. Until
that process is complete, NMFS will continue its long-standing practice
of considering specific modifications to the acoustic 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.
Modifications to HSTT, AFTT, MITT, and GOA Final Rules
The Navy is also requesting that NMFS authorize modifications to
watchstander requirements, unrelated to implementation of mitigation
measures, for observed behavior of marine mammals during MTEs in the
HSTT, AFTT, MITT, and GOA study areas. With these proposed
modifications the Navy would no longer be required to report individual
marine mammal sighting information during MTEs when mitigation is not
occurring in the study area. After 5 years of collecting marine mammal
sighting data for all animals sighted during MTEs, NMFS and Navy have
determined that without the ability to obtain species information this
data set does not provide for any meaningful analysis beyond that which
may be possible using mitigation-related observations alone. The Navy
and NMFS have thoroughly investigated several potential uses for the
data prior to reaching this conclusion. Additionally, this reporting
requirement places an undue administrative burden on ships watch teams.
The Navy will continue to collect marine mammal sighting data during
MTEs for every instance when any form of mitigation is employed such as
powering down or securing sonar, maneuvering the ship, or delaying an
event--in other words, in instances where animals are closer to the
sound source around which mitigation measures are implemented. This
data is useful in supporting mitigation effectiveness analyses and also
may be helpful in supporting an understanding of the frequency with
which marine mammals (generally, not by species) may be encountered or
detected in close proximity to a particular source (e.g., where the
likelihood of auditory or other injury is higher). Additionally, the
Navy will continue to implement their separate Integrated Comprehensive
Monitoring Program, which includes studies that are specifically
designed to contribute to our understanding of the animals affected and
how Navy training and testing impacts them.
These modifications would be implemented through the revision of
regulatory text for existing regulations governing the taking of marine
mammals incidental to testing and/or training activities in HSTT, AFTT,
MITT, and GOA study areas. Proposed revisions to the regulatory text
are provided in the regulatory text at the end of this proposed rule.
Proposed revisions to MITT regulatory text will be made in the MITT
final rule, which is currently being prepared concurrent with the NWTT
proposed rule and is expected to publish in the Federal Register prior
to the NWTT final rule. There are no MTEs or marine mammal sighting
reporting requirements associated with Navy training and testing
activities in the NWTT study area.
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 NWTT Study Area, which have been ongoing for
decades with some activities dating back to at least the early 1900s.
The tempo and types of training and testing activities have fluctuated
because of the introduction of new technologies, the evolving nature of
international events, advances in war fighting doctrine and procedures,
and force structure (organization of ships, submarines, aircraft,
weapons, and personnel) changes. Such developments influence the
frequency, duration, intensity, and location of required training and
testing activities. The Navy analyzed many training and testing
activities in the Study Area in the Tactical Training Theater
Assessment and Planning Program Phase I and earlier documents,
specifically the following environmental planning documents: Northwest
Training Range Complex Final EIS/OEIS (U.S. Department of the Navy,
2010a), NAVSEA NUWC Keyport Range Complex Extension Final EIS/OEIS
(U.S. Department of the Navy, 2010b), and the Final EIS for the
Southeast Alaska Acoustic Measurement Facility (SEAFAC) (U.S.
Department of the Navy, 1988). The Navy's LOA request covers training
and testing activities that would occur for a 5-year period following
the expiration of the first of the two current MMPA authorizations

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(Northwest Training Range Complex; Keyport Range Complex). The Navy has
also prepared and released to the public a January 2014 DEIS/OEIS
analyzing the effects on the human environment of implementing their
preferred alternative (among others). The January 2014 NWTT DEIS/OEIS
(which is part of Phase II of the program) accounts for planned
adjustments to tempo and types of activities dictated by military
readiness requirements. A NOI to prepare a Supplement to the January
2014 NWTT DEIS/OEIS was published on October 24, 2014 and the draft
Supplement was released to the public on December 19, 2014. The
Supplement focused on changes to the Proposed Action due to updated
training requirements and significant new information relevant to
environmental concerns per 40 CFR 1502.9.
The Navy's LOA application differs from the January 2014 NWTT DEIS/
OEIS in that it contains updated information on the Washington Inland
Waters stocks of harbor seals (Carretta et al., 2014) and their
abundance in Hood Canal based on a new application of London et al.
(2012). The January 2014 NWTT DEIS/OEIS analysis relied on NMFS' Stock
Assessment Reports (SARs) through 2013 (Carretta et al., 2014), which
did not incorporate the London et al. findings. London et al. (2012)
reported the variability of harbor seal haulout behavior in a sub-
portion of Hood Canal, covering 5 months of the year (July-November).
The paper provided a range of haulout probabilities in Hood Canal that
differed from the single value (65 percent--Huber et al., 2001)
previously used by NMFS and Navy to calculate harbor seal abundance.
Recently, in discussions between the Navy and NMFS it was determined
that it is now appropriate to incorporate London et al. (2012) for the
Hood Canal stock only. This resulted in increasing the population
estimate of the Hood Canal stock of harbor seals by a factor of
approximately 3.26, resulting in a new abundance estimate of 3,555. In
addition, in calculating its exposure estimates, the Navy also applied
the haulout probability of 20 percent derived from London et al. (2012)
which changed the percentage of harbor seals in the water from 35
percent (Huber et al., 2001) to 80 percent. These changes in
assumptions result in a corresponding increase in estimated exposures
because the Navy is assuming that there are more harbor seals present
in Hood Canal and more of the animals will be in the water at any given
time compared to the analysis presented in the January 2014 NWTT DEIS/
OEIS. The result of these changes in the best available science is that
the Navy has estimated additional Level A and Level B takes for
training and testing activities per year. These changes to the
estimates presented in the January 2014 NWTT DEIS/OEIS do not reflect a
change in the Navy's proposed action nor a significant change to Navy's
methodology. The vast majority of the increased exposure estimates are
Level B harassment exposures that derive from the Navy's already
conservative acoustic effects model. The Navy has determined that these
Level A and Level B harassment exposures are not biologically
significant to the population because (1) none of the estimated
exposures result in mortality; (2) the monitoring and mitigations
employed would likely reduce the severity of Level A exposures; (3)
there are no indications that the historically occurring activities
resulting in these behavioral harassment exposures are having any
effect on this population's survival by altering behavior patterns such
as breeding, nursing, feeding, or sheltering; (4) the population has
been stable and likely at carrying capacity (Jeffries et al., 2003);
(5) the population continues to use known large haulouts in Hood Canal
and Dabob Bay that are adjacent to Navy testing and training
activities; (6) the population continues to use known haulouts for
pupping; and (7) the population continues to use the waters in and
around Dabob Bay and Hood Canal. As such, the Navy has determined, and
NMFS concurs, that it is not necessary to supplement the January 2014
NWTT DEIS/OEIS analysis as this information is not new significant
information to the environmental impacts. However, the Navy has advised
NMFS that all comments received on the proposed rule that address the
changes in take estimates for the Hood Canal stock of harbor seals will
be addressed by the Navy in its Final EIS/OEIS for NWTT.

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 and underwater detonations 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 January 2014 NWTT DEIS/OEIS and in the LOA application
(http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm) and are
summarized here.

Overview of Training Activities

The Navy routinely trains in the NWTT Study Area in preparation for
national defense missions. Training activities and exercises covered in
the Navy's LOA request are briefly described below, and in more detail
within Chapter 2 of the January 2014 NWTT DEIS/OEIS. 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:

Anti-surface warfare (impulsive sources [underwater
detonations])
Anti-submarine warfare (non-impulsive sources [active sonar],
impulsive underwater detonations)
Mine warfare (non-impulsive sources, impulsive underwater
detonations)

The Navy's activities in anti-air warfare, electronic warfare, and
naval special warfare do not involve stressors that could result in
harassment of marine mammals. Therefore, these activities are not
discussed further. The analysis and rationale for excluding these
warfare areas is contained in the January 2014 DEIS/OEIS.

Anti-Surface Warfare

The mission of anti-surface warfare (ASUW) 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 (ASW) 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

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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 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.

Other Activities

Other activities include pierside and at-sea maintenance of
submarine and surface ship sonar systems.

Overview of Testing Activities

Testing activities covered in the Navy's LOA request are briefly
described below, and in more detail within Chapter 2 of the January
2014 NWTT DEIS/OEIS. The Navy researches, develops, tests, and
evaluates new platforms, systems and technologies. Many tests are
conducted in realistic conditions at sea, and can range in scale from
testing new software to operating portable devices to conducting tests
of live weapons (such as the Service Weapon Test of a torpedo) to
ensure they function as intended. 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 described above. Other testing activities are unique and are
described within their specific testing categories. Because each test
is conducted by a specific component of the Navy's research and
acquisition community, which includes the Navy's Systems Commands and
the Navy's scientific research organizations, the testing activities
described in the LOA application are organized first by that particular
organization as described below and in the order as presented.
The Navy describes and analyzes the effects of its testing
activities within the 2014 NWTT DEIS/OEIS. In its assessment, the Navy
concluded that acoustic stressors from the use of underwater acoustic
sources and underwater detonations resulted in impacts on marine
mammals that rose to the level of harassment as defined under the MMPA.
Therefore, the LOA application for NWTT provides the Navy's assessment
of potential effects from these stressors in terms of the various
activities in which they would be used.
The individual commands within the research and acquisition
community included in the NWTT DEIS/OEIS and in the LOA application
are:

Naval Sea Systems Command (NAVSEA). Within NAVSEA are the
following field activities:
[cir] Naval Undersea Warfare Center (NUWC) Division, Keyport
[cir] Naval Surface Warfare Center, Carderock Division (NSWCCD),
Detachment Puget Sound
[cir] NSWCCD Southeast Alaska Acoustic Measurement Facility (SEAFAC)
[cir] Puget Sound Naval Shipyard and Intermediate Maintenance Facility
[cir] Various NAVSEA program offices
Naval Air Systems Command (NAVAIR)

Naval Sea Systems Command Testing Events

NAVSEA is responsible for engineering, building, buying, and
maintaining the Navy's ships and submarines and associated combat
systems. NAVSEA is broken up into two types of warfare centers: NUWC
and the Naval Surface Warfare Center (NSWC).
NUWC provides Fleet readiness support for submarines, surface
ships, torpedoes, mines, land attack systems, and Fleet training
systems. NAVSEA has several field activities operating out of Naval
Base (NAVBASE) Kitsap, including NUWC Division Keyport, NSWCCD
Detachment Puget Sound, and Puget Sound Naval Shipyard and Intermediate
Maintenance Facility. NSWCCD Detachment Puget Sound also operates the
SEAFAC facility in Alaska.
Each major category of NAVSEA activities in the Study Area is
represented below. NUWC Division, Keyport and NSWCCD Detachment Puget
Sound activities are grouped together in the discussion below to
simplify review due to the diversity of activity types and locations
they work in. Puget Sound Naval Shipyard and Intermediate Facility
activities are grouped with the general activities conducted by NAVSEA.
Numerous test activities and technical evaluations, in support of
NAVSEA's systems development mission, often occur in conjunction with
fleet activities within the Study Area.

Naval Undersea Warfare Center Division, Keyport Testing Activities

NUWC Division Keyport's mission is to provide test and evaluation
services and expertise to support the Navy's evolving manned and
unmanned vehicle program activities. NUWC Keyport has historically
provided facilities and capabilities to support testing of torpedoes,
other unmanned vehicles, submarine readiness, diver training, and
similar activities that are critical to the success of undersea
warfare. Range support requirements for such activities include
testing, training, and evaluation of system capabilities such as
guidance, control, and sensor accuracy in multiple marine environments
(e.g., differing depths, salinity levels, sea states) and in surrogate
and simulated war-fighting environments. Technological advancements in
the materials, instrumentation, guidance systems, and tactical
capabilities of manned and unmanned vehicles continue to evolve in
parallel with emerging national security priorities and threat
assessments. However, NUWC Keyport does not utilize explosives in any
testing scenarios.

Naval Surface Warfare Center, Carderock Division

NSWCCD includes two organizations that conduct testing activities:
NSWCCD, Detachment Puget Sound and NSWCCD SEAFAC. Detachment Puget
Sound testing activities are aligned with its mission to provide
research, development, test, and evaluation (RDT&E), analysis,
acquisition support, in-service engineering, logistics and integration
of surface and undersea vehicles and associated systems; develop and
apply science and technology associated with naval architecture and
marine engineering; and provide support to the maritime industry.
Activities and support include engineering, technical, operations,
diving, and logistics required for the RDT&E associated with:

Advanced Technology Concepts, Engineering and Proofing

[[Page 31742]]

Experimental Underwater Vehicles, Systems, Subsystems and
Components
Specialized Underwater Systems, Equipment, Tools and Hardware
Acoustic Data Acquisition, Analysis and Measurement Systems
(required to measure U.S. Navy Acoustic Signatures).

These activities can be broken down into four major testing
categories to include: System, Subsystem and Component Acoustic Testing
Pierside; Performance Testing at Sea; Development Testing and Training;
and Proof of Concept Testing.
NSWCCD SEAFAC makes high fidelity directive volumetric and line
arrays passive acoustic signature measurements. The SEAFAC site
includes directive line arrays and data collection and processing
systems for real-time data analysis and signature evaluation.
SEAFAC provides the capability to perform RDT&E analyses to
determine the sources of radiated acoustic noise, to assess
vulnerability, and to develop quieting measures. Unforeseen emergent
Navy requirements may influence actual testing activities during the
time period under consideration. Testing activities that would occur at
SEAFAC are identified to the extent practicable throughout this
application.

Naval Sea Systems Command Program Office Sponsored Testing Activities

NAVSEA also conducts tests that are not associated with NUWC
Keyport or NSWCCD. Activities are conducted at Navy piers at NAVBASE
Kitsap, Bremerton; NAVBASE Kitsap, Bangor; and Naval Station Everett;
and in conjunction with fleet activities off the coast of Washington,
Oregon, and northern California. Tests within this category include,
but are not limited to, Life Cycle Activities, Shipboard Protection
Systems and Swimmer Defense Testing, Unmanned Vehicle Testing, ASUW/ASW
Testing, and New Ship Construction.

Naval Air Systems Command Testing Events

NAVAIR testing events generally fall into the primary mission areas
used by the fleets. NAVAIR events include, but are not limited to, the
testing of new aircraft platforms, weapons, and systems before those
platforms, weapons and systems are integrated into the fleet. In this
application, NAVAIR testing activities are limited to ASW testing of
sonobuoys. The sonobuoys tested include both passive and active non-
impulsive, sonobuoys using impulsive sources, and high duty cycle
sonobuoys.

Description of 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 LOA 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 Active Acoustic 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. Sources of sonar and
other active acoustic sources include surface ship sonar, sonobuoys,
torpedoes, range pingers, and unmanned underwater vehicles.

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 the
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 for towed systems, which can rapidly assess
large areas.
Airborne Laser Mine Detection Systems. Airborne laser
detection systems work in concert with neutralization systems. The
detection system initially locates mines and a neutralization system is
then used to relocate and neutralize the mine.

[[Page 31743]]

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.
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. Mine neutralization
systems can clear individual mines or a large number of mines quickly.
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.
Towed mechanical mine sweeping systems.These systems tow a
sweep wire to snag the line that attaches a moored mine to its anchor
and then uses a series of cables and cutters to sever those lines. Once
these lines are cut, the mines float to the surface where Navy
personnel can neutralize the mines.
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.
Projectiles. Small- and medium-caliber projectiles, fired
from surface ships or hovering helicopters, are used to neutralize
floating and near-surface mines.
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.
Explosive charges are used during mine neutralization system
training activities; however, only non-explosive mines or mine shapes
would be used.
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 kHz, 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 in the January 2014 NWTT DEIS/
OEIS. These sources generally meet the following criteria:

Acoustic sources with frequencies greater than 200 kHz (based
on known marine mammal hearing ranges)
Sources with source levels less than 160 dB

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).
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).
E8................................ 250 lb. (113.4 kg) bomb.... >60-100 (>27.2-45.4 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).
----------------------------------------------------------------------------------------------------------------

[[Page 31744]]

Table 2--Non-Impulsive Training Source Classes Analyzed
------------------------------------------------------------------------
Source class category Source class Description
------------------------------------------------------------------------
Mid-Frequency (MF): Tactical and MF1.......... Active hull-mounted
non-tactical sources that surface ship sonar
produce mid-frequency (1 to 10 (e.g., AN/SQS-53C and
kHz) signals. AN/SQS-60).
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\2\).
MF11......... Hull-mounted surface
ship sonar with an
active duty cycle
greater than 80%.
High-Frequency (HF) and Very HF1.......... Active hull-mounted
High-Frequency (VHF): Tactical HF4.......... submarine sonar (e.g.,
and non-tactical sources that AN/BQQ-15).
produce high-frequency (greater Active mine detection,
than 10 kHz but less than 200 classification, and
kHz) signals. neutralization sonar
(e.g., AN/SQS-20).
HF6.......... Active sources (equal
to 180 dB and up to
200 dB).
Anti-Submarine Warfare (ASW): ASW2......... MF active Multistatic
Tactical sources such as active ASW3......... Active Coherent (MAC)
sonobuoys and acoustic sonobuoy (e.g., AN/SSQ-
countermeasures systems used 125).
during ASW training activities. MF active towed active
acoustic
countermeasure systems
(e.g., AN/SLQ-25
NIXIE).
------------------------------------------------------------------------

Table 3--Non-Impulsive Testing Source Classes Analyzed
------------------------------------------------------------------------
Source class category Source class Description
------------------------------------------------------------------------
Low-Frequency (LF): Sources that LF4.......... Low-frequency sources
produce low-frequency (less LF5.......... equal to 180 dB and up
than 1 kilohertz [kHz]) signals. to 200 dB.
Low-frequency sources
less than 180 dB.
Mid-Frequency (MF): Tactical and MF3.......... Hull-mounted submarine
non-tactical sources that MF4.......... sonar (e.g., AN/BQQ-
produce mid-frequency (1 to 10 10).
kHz) signals. 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.
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.......... Hull-mounted submarine
High-Frequency (VHF): Tactical HF3.......... sonar (e.g., AN/BQQ-
and non-tactical sources that HF5 \1\...... 10).
produce high-frequency (greater Hull-mounted submarine
than 10 kHz but less than 200 sonar (classified).
kHz) signals. Active sources (greater
than 200 dB).
HF6.......... Active sources (equal
to 180 dB and up to
200 dB).
VHF2......... Active sources with a
frequency greater than
100 kHz, up to 200 kHz
with a source level
less than 200 dB.
Anti-Submarine Warfare (ASW): ASW1......... Mid-frequency Deep
Tactical sources such as active ASW2......... Water Active
sonobuoys and acoustic Distributed System
countermeasures systems used (DWADS).
during the conduct of ASW Mid-frequency
testing activities. Multistatic Active
Coherent sonobuoy
(e.g., AN/SSQ-125)--
sources analyzed by
number of items
(sonobuoys).
ASW2......... 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).
Torpedoes (TORP): Source classes TORP1........ Lightweight torpedo
associated with the active TORP2........ (e.g., MK-46, MK-54).
acoustic signals produced by Heavyweight torpedo
torpedoes. (e.g., MK-48, electric
vehicles).
Acoustic Modems (M): Systems M3........... Mid-frequency acoustic
used to transmit data modems (greater than
acoustically through water. 190 dB) (e.g.,
Underwater Emergency
Warning System, Aid to
Navigation).
Swimmer Detection Sonar (SD): SD1.......... High-frequency sources
Systems used to detect divers with short pulse
and submerged swimmers. lengths, used for the
detection of swimmers
and other objects for
the purpose of port
security.
Synthetic Aperture Sonar (SAS): SAS2......... High frequency unmanned
Sonar in which active acoustic underwater vehicle
signals are post-processed to (UUV) (e.g., UUV
form high-resolution images of payloads).
the seafloor.
------------------------------------------------------------------------
Notes: \1\ For this analysis, HF5 consists of only one source; the
modeling was conducted specifically for that source.
\2\ DICASS = Directional Command Activated Sonobuoy System Proposed
Action.

[[Page 31745]]

Training and Testing

The training and testing activities that the Navy proposes to
conduct in the NWTT Study Area are listed in Tables 4-6. Detailed
information about each proposed activity (stressor, training or testing
event, description, sound source, duration, and geographic location)
can be found in the LOA application and in Appendix A of the January
2014 NWTT DEIS/OEIS. NMFS used the detailed information in the LOA
application and in Appendix A of the January 2014 NWTT DEIS/OEIS to
analyze the potential impacts from training and testing activities on
marine mammals. The Navy's proposed activities are anticipated to meet
training and testing needs in the years 2015-2020.

Summary of Impulsive and Non-Impulsive Sources

Table 4 provides a quantitative annual summary of training
activities by sonar and other active acoustic source class analyzed in
the Navy's LOA request.

Table 4--Annual Hours of Sonar and Other Active Acoustic Sources Used
During Training Within the NWTT Study Area
------------------------------------------------------------------------
Source class category Source class Annual use
------------------------------------------------------------------------
Mid-Frequency (MF) Active sources MF1............ 166 hours.
from 1 to 10 kHz. MF3............ 70 hours.
MF4............ 4 hours.
MF5............ 896 items.
MF11........... 16 hours.
High-Frequency (HF) Tactical and HF1............ 48 hours.
non-tactical sources that HF4............ 384 hours.
produce signals greater than 10 HF6............ 192 hours.
kHz but less than 100 kHz.
Anti-Submarine Warfare (ASW)..... ASW2........... 720 items.
ASW3........... 78 hours.
------------------------------------------------------------------------

Table 5 provides a quantitative annual summary of testing
activities by sonar and other active sources analyzed in the Navy's LOA
request.

Table 5--Annual Hours of Sonar and Other Active Acoustic Sources Used
During Testing Within the NWTT Study Area
------------------------------------------------------------------------
Source class category Source class Annual use
------------------------------------------------------------------------
Low-Frequency (LF): Sources that LF4............ 110 hours.
produce signals less than 1 kHz. LF5............ 71 hours.
Mid-Frequency (MF): Tactical and MF3............ 161 hours.
non-tactical sources that MF4............ 10 hours.
produce signals from 1 to 10 kHz. MF5............ 273 items.
MF6............ 12 items.
MF8............ 40 hours.
MF9............ 1,183 hours.
MF10........... 1,156 hours.
MF11........... 34 hours.
MF12........... 24 hours.
High-Frequency (HF) and Very High- HF1............ 161 hours.
Frequency (VHF): Tactical and HF3............ 145 hours.
non-tactical sources that HF5 \1\........ 360 hours.
produce signals greater than 10 HF6............ 2,099 hours.
kHz but less than 200 kHz.
Very High-Frequency (VHF): VHF2........... 35 hours.
Tactical and non-tactical
sources that produce signals
greater than 100 kHz but less
than 200 kHz.
Anti-Submarine Warfare (ASW): ASW1........... 16 hours.
Tactical sources used during ASW ASW2 \2\....... 64 hours.
training and testing activities. ASW2 \2\....... 170 items.
ASW3........... 444 hours.
ASW4........... 1,182 hours.
Torpedoes (TORP): Source classes TORP1.......... 315 items.
associated with active acoustic TORP2.......... 299 items.
signals produced by torpedoes.
Acoustic Modems (M): Transmit M3............. 1,519 hours.
data acoustically through the
water.
Swimmer Detection Sonar (SD): SD1............ 757 hours.
Used to detect divers and
submerged swimmers.
Synthetic Aperture Sonar (SAS): SAS2........... 798 hours.
Sonar in which active acoustic
signals are post-processed to
form high-resolution images of
the seafloor.
------------------------------------------------------------------------
\1\ For this analysis, HF5 consists of only one source; the modeling was
conducted specifically for that source.
\2\ The ASW2 bin contains sources that are analyzed by hours and some
that are analyzed by count of items. There is no overlap of the
numbers in the two rows.

Table 6 provides a quantitative annual summary of training
explosive source classes analyzed in the Navy's LOA request.

[[Page 31746]]

Table 6--Proposed Annual Number of Impulsive Source Detonations During
Training in the NWTT Study Area
------------------------------------------------------------------------
Annual in-water
Explosive class Net explosive weight detonations
(NEW) (training)
------------------------------------------------------------------------
E1............................ (0.1 lb.-0.25 lb.)... 48
E3............................ (>0.5 lb.-2.5 lb.)... 6
E5............................ (>5 lb.-10 lb.)...... 80
E10........................... (>250 lb.-500 lb.)... 4
E12........................... (>650 lb.-1000 lb.).. 10
------------------------------------------------------------------------

Table 7 provides a quantitative annual summary of testing explosive
source classes analyzed in the Navy's LOA request.

Table 7--Proposed Annual Number of Impulsive Source Detonations During
Testing in the NWTT Study Area
------------------------------------------------------------------------
Annual In-Water
Explosive class Net explosive weight Detonations
(NEW) (testing)
------------------------------------------------------------------------
E3............................ (>0.5 lb.-2.5 lb.)... 72
E4............................ (>2.5 lb.-5 lb.)..... 70
E8............................ (>60 lb.-100 lb.).... 3
E11........................... (>500 lb.-650 lb.)... 3
------------------------------------------------------------------------

Other Stressors--Vessel Strikes

In addition to potential impacts to marine mammals from activities
using explosives or sonar and other active acoustic sources, the Navy
also considered ship strike impacts to marine mammals. The Navy
assessed that no additional stressors would result in a take and
require authorization under the MMPA.
Vessel strikes may occur from surface operations and sub-surface
operations (excluding bottom crawling, unmanned underwater vehicles).
Vessels used as part of the Navy's proposed NWTT training and testing
activities (proposed action) include ships, submarines and boats
ranging in size from small, 16-foot (ft.) (5-meter [m]) rigid hull
inflatable boats to aircraft carriers with lengths up to 1,092 ft. (333
m). Representative Navy vessel types, lengths, and speeds used in both
training and testing activities are shown in Table 8.

Table 8--Representative Navy Vessel Types, Lengths, and Speeds Used Within the NWTT Study Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vessel type Example(s) Length Typical operating speed Max speed
--------------------------------------------------------------------------------------------------------------------------------------------------------
Aircraft Carrier.................... Aircraft Carrier....... >900 ft (>300 m)........................ 10-15 knots.............. 30+ knots
Surface Combatants.................. Cruisers, Destroyers, 330-660 ft (100-200 m).................. 10-15 knots.............. 30+ knots
Frigates, Littoral
Combat Ships.
Support Craft/Other................. Range Support Craft, 16-250 ft (5-80 m)...................... Variable................. 20 knots
Combat Rubber Raiding
Craft, Landing Craft,
Utility; Submarine
Tenders, Yard Patrol
Craft, Protection
Vessels, Barge.
Support Craft/Other--Specialized Patrol Coastal Ships, 33-130 ft (10-40 m)..................... Variable................. 50+ knots
High Speed. Patrol Boats, Rigid
Hull Inflatable Boat,
High Speed Protection
Vessels.
Submarines.......................... Fleet Ballistic Missile 330-660 ft (100-200 m).................. 8-13 knots............... 20+ knots
Submarines, Attack
Submarines, Guided
Missile Submarines.
--------------------------------------------------------------------------------------------------------------------------------------------------------

Large Navy ships greater than 65 ft. (20 m) generally operate at
speeds in the range of 10-15 knots for fuel conservation when cruising.
Submarines generally operate at speeds in the range of 8-13 knots
during transit and slower for certain tactical maneuvers. Small craft
(for purposes of this discussion less than 65 ft. [20 m] in length)
have much more variable speeds, dependent on the mission. 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, etc.
The number of Navy vessels in the 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 2 weeks. Vessel movement and the use of in-water
devices as part of the proposed action would be concentrated in certain

[[Page 31747]]

portions of the Study Area (such as Western Behm Canal [Alaska] or Hood
Canal in the inland waters portion of the Study Area) but may occur
anywhere within the Study Area.
The Navy is analyzing the potential environmental impacts of
approximately 226 ongoing annual Maritime Security Operations events in
Puget Sound and the Strait of Juan de Fuca. These critical events have
been occurring since 2006 and exercise the Navy's Transit Protection
System, where up to nine escort vessels provide protection during all
nuclear ballistic missile submarine (SSBN) transits between the
vessel's homeport and the dive/surface point in the Strait of Juan de
Fuca or Dabob Bay. During a Transit Protection System event, the
security escorts enforce a moving 1,000 yard security zone around the
SSBN to prevent other vessels from approaching while the SSBN is in
transit on the surface. These events include security escort vessels,
U.S. Coast Guard personnel and their ancillary equipment and weapons
systems. The Transit Protection System involves the movement of
security vessels and also includes periodic exercises and firearms
training (with blank rounds). Given the relative slow speed of the
escorted and blocking vessels and multiple lookouts, no marine mammal
vessel strikes are expected as a result of these events.
Navy policy (Chief of Naval Operations Instruction 3100.6H)
requires Navy vessels to report all whale strikes. That information is
collected by the Office of the Chief of Naval Operations Energy and
Environmental Readiness Division (OPNAV N45) and cumulatively provided
to NMFS on an annual basis. In addition, the Navy and NMFS also have
standardized regional reporting protocols for communicating to regional
NMFS stranding coordinators information on any Navy vessel strikes as
soon as possible. These communication procedures will remain in place
for the duration of the LOAs. There are no records of any Navy vessel
strikes to marine mammals during training or testing activities in the
NWTT Study Area.

Duration and Location

Training and testing activities would be conducted in the Study
Area throughout the year from November 2015 through November 2020.
The Study Area is composed of established maritime operating and
warning areas in the eastern North Pacific Ocean region, including
areas of the Strait of Juan de Fuca, Puget Sound, and Western Behm
Canal in southeastern Alaska. The Study Area includes air and water
space within and outside Washington state waters, and outside state
waters of Oregon and Northern California. The Study Area includes four
existing range complexes and facilities: The Northwest Training Range
Complex (NWTRC), the Keyport Range Complex, Carr Inlet Operations Area,
and SEAFAC. In addition to these range complexes, the Study Area also
includes Navy pierside locations where sonar maintenance and testing
occurs as part of overhaul, modernization, maintenance and repair
activities at NAVBASE Kitsap, Bremerton; NAVBASE Kitsap, Bangor; and
Naval Station Everett.
A range complex is a designated set of specifically bounded
geographic areas and encompasses a water component (above and below the
surface), and may encompass airspace and a land component where
training and testing of military platforms, tactics, munitions,
explosives, and EW systems occurs. Range complexes include established
OPAREAs, Restricted Areas, and special use airspace (SUA), which may be
further divided to provide better control of the area and events for
safety reasons. These designations are further described in Chapter 2
of the LOA application.
The Study Area includes only the at-sea components of the training
and testing areas and facilities. The Navy is using ``at-sea'' to cover
activity in, on, and over the water, but not activity on or over the
land, which may include activities in the surf zone or supported from
shore-side locations.
Military activities in the Study Area occur (1) on the ocean
surface, (2) beneath the ocean surface, and (3) in the air. To aid in
the description of the ranges covered in the January 2014 NWTT DEIS/
OEIS, the ranges are divided into three distinct geographic and
functional subdivisions. All of the training and testing activities
proposed in this application would occur in one or more of these three
range subdivisions:

The Offshore Area
The Inland Waters
Western Behm Canal, Alaska

Offshore Area

The Offshore Area of the Study Area includes air, surface, and
subsurface OPAREAs extending generally west from the coastline of
Washington, Oregon, and Northern California for a distance of
approximately 250 nm into international waters. The eastern boundary of
the Offshore Area is 12 nm off the coastline for most of the Study
Area, including southern Washington, Oregon, and Northern California.
The Offshore Area includes the ocean all the way to the coastline only
along the Washington coast beneath the airspace of W-237 and the
Olympic Military Operations Area (MOA) and the Washington coastline
north of the Olympic MOA. The components of the Offshore Area are
described below.

Airspace

The SUA in the Offshore Area is comprised of Warning Area 237 (W-
237), which extends westward off the coast of Northern Washington State
and is divided into nine sub-areas (A-H, and J). The eastern boundary
of W-237 lies 3 nm off the coast of Washington. The floor of W-237
extends to the ocean surface and the ceiling of the airspace varies
between 27,000 ft. (8,200 m) in areas E, H, and J; 50,000 ft. (15,200
m) in areas A and B; and unlimited in areas C, D, F, and G, with a
total area of 25,331 square nautical miles (nm\2\).
The Olympic MOA overlays both land (the Olympic Peninsula) and sea
(extending to 3 nm off the coast of Washington into the Pacific Ocean).
The MOA lower limit is 6,000 ft. (1,800 m) above mean sea level but not
below 1,200 ft. above ground level, and the upper limit is up to, but
not including, 18,000 ft. (5,500 m), with a total area coverage of
1,614 nm\2\.
Above the Olympic MOA is the Olympic Air Traffic Controlled
Assigned Airspace (ATCAA), which has a floor coinciding with the
Olympic MOA ceiling. The ATCAA has an upper limit of 35,000 ft. (10,700
m).

For the LOA application, the Olympic MOA and the Olympic ATCAA Are
components of the Offshore Area

Inland Waters

The Inland Waters includes air, sea, and undersea space inland of
the coastline, from buoy ``J'' at 48[deg] 29.6' N, 125[deg] W, eastward
to include all waters of the Strait of Juan de Fuca and the Puget
Sound. None of this area extends into Oregon or California. Within the
Inland Waters are specific geographic components in which training and
testing occur. The Inland Waters and its component areas are described
below.

Airspace

Restricted Area 6701 (R-6701, Admiralty Bay) is a Restricted Area
over Admiralty Bay, Washington with a lower limit at the ocean surface
and an upper limit of 5,000 ft. This airspace covers a total area of 56
nm\2\.
Chinook A and B MOAs are 56 nm\2\ of airspace south and west of
Admiralty Bay. The Chinook MOAs extend from 300 ft. to 5,000 ft. above
the ocean surface.

[[Page 31748]]

Sea and Undersea Space

Explosive Ordnance Disposal Underwater Ranges--Two active EOD
ranges are located in the Inland Waters at the following locations:
Hood Canal EOD Training Range
Crescent Harbor EOD Training Range
Surface and Subsurface Testing Sites--There are three
geographically distinct range sites in the Inland Waters where the Navy
conducts surface and subsurface testing and some limited training. The
Keyport Range Site is located in Kitsap County and includes portions of
Liberty Bay and Port Orchard Reach (also known as Port Orchard
Narrows). The Dabob Bay Range Complex (DBRC) Site is located in Hood
Canal and Dabob Bay, in Jefferson, Kitsap, and Mason counties. The Carr
Inlet OPAREA is located in southern Puget Sound.
The Keyport Range Site is located adjacent to NAVBASE Kitsap,
Keyport, providing approximately 3.2 nm\2\ for testing, including in-
shore shallow water sites and a shallow lagoon to support integrated
undersea warfare systems and vehicle maintenance and engineering
activities. Water depth at the Keyport Range Site is less than 100 ft.
(30.5 m). Underwater tracking of test activities can be accomplished by
using temporary or portable range equipment. The Navy has conducted
testing at the Keyport Range Site since 1914.
The DBRC Site includes the Dabob Bay and the Hood Canal from 1 mi.
(1.6 km) south of the Hood Canal Bridge to the Hamma Hamma River, a
total area of approximately 45.7 nm\2\. The Navy has conducted
underwater testing at the DBRC Site since 1956, beginning with a
control center at Whitney Point. The control center was subsequently
moved to Zelatched Point.
Dabob Bay is a deep-water area in Jefferson County approximately
14.5 nm\2\ in size and contains an acoustic tracking range. The
acoustic tracking space within the range is approximately 7.3 nm by 1.3
nm (9 nm\2\) with a maximum depth of 600 ft. (182.9 m). The Dabob Bay
tracking range, the only component of the DBRC Site with extensive
acoustic monitoring instrumentation installed on the seafloor, provides
for object tracking, communications, passive sensing, and target
simulation. Many activities conducted within Dabob Bay are supported by
land-based facilities at Zelatched Point.
Hood Canal averages a depth of 200 ft. (61 m) and is used for
vessel sensor accuracy tests and launch and recovery of test systems
where tracking is optional.
The Carr Inlet OPAREA is a quiet deep-water inland range
approximately 12 nm\2\ in size. It is located in an arm of water
between Key Peninsula and Gig Harbor Peninsula. Its southern end is
connected to the southern basin of Puget Sound. Northward, it separates
McNeil Island and Fox Island as well as the peninsulas of Key and Gig
Harbor. The acoustic tracking space within the range is approximately 6
nm by 2 nm with a maximum depth of 545 ft. (166 m). The Navy performed
underwater acoustic testing at Carr Inlet from the 1950s through 2009,
when activities were relocated to NAVBASE Kitsap, Bangor. While no
permanently installed structures are present in the Carr Inlet OPAREA,
the waterway remains a Navy-restricted area.
Pierside Testing Facilities--In addition to the training and
testing ranges, at which most of the training and testing assessed in
this document occurs, the Navy conducts some testing at or near Navy
piers. Most of this testing is sonar maintenance and testing while
ships are in port for maintenance or system re-fitting. These piers
within the Study Area are all within Puget Sound and include the
NAVBASE Kitsap, Bremerton in Sinclair Inlet; NAVBASE Kitsap, Bangor
Waterfront in Hood Canal, and Naval Station Everett.
Navy Surface Operations Areas--In addition to the areas mentioned
above, there are two surface and subsurface operations areas used for
Navy training and testing within the Inland Waters. Navy 3 OPAREA is a
surface and subsurface area off the west coast of northern Whidbey
Island. Navy 7 OPAREA is the surface and subsurface area that lies
beneath R-6701. This area covers a total area of 61 nm\2\.

Western Behm Canal, Alaska

The Western Behm Canal is located in Southeast Alaska, near the
city of Ketchikan, Alaska. SEAFAC is located in the Western Behm Canal
and covers an area of 48 nm\2\. The Navy has been conducting testing
activities at SEAFAC since 1992. The facility replaced the Santa Cruz
Acoustic Range Facility in Southern California and is now the location
for some acoustic testing previously conducted at the NSWC Carr Inlet
Acoustic Range in Washington State.
SEAFAC is comprised of land-based facilities and in-water assets.
The land-based facilities are located within 5.5 acres (2 hectares) on
Back Island and are not included in the scope of this analysis. The in-
water assets include two sites: the underway site and the static site.
These assets and the operational area of SEAFAC are located in five
restricted areas. The underway site arrays are in Area 1. The static
site is in Area 2. All associated underwater cabling and other devices
associated with the underway site are located in Area 3. Area 4
provides a corridor for utility power and a phone cable. Area 5 is an
operational area to allow for safe passage of local vessel traffic.
Notifications of invoking restriction of Area 5 occur at least 72 hours
prior to SEAFAC operations in accordance with 33 CFR 34.1275. During
test periods, all vessels entering Area 5 are requested to contact
SEAFAC to coordinate safe passage through the area. Area 5 defines the
SEAFAC Study Area boundary, which is comprised only of the in-water
area and excludes the land-based supporting facilities and operations.
The SEAFAC at-sea areas are:
Restricted Areas 1 through 5. The five restricted areas
are located within Western Behm Canal. The main purposes of the
restricted areas are to provide for vessel and public safety, lessen
acoustic encroachment from non-participating vessels, and prohibit
certain activities that could damage SEAFAC's sensitive in-water
acoustic instruments and associated cables. Area 5 encompasses the
entire SEAFAC operations area.
Underway Measurement Site. The underway measurement site
is in the center of Western Behm Canal and is 5,000 yards (yd.) (4,572
m) wide and 12,000 yd. (10,973 m) long. The acoustic arrays are located
at the center of this area (Area 1).
Static Site. The static site is approximately 2 nm
northwest of Back Island. During testing, a vessel is tethered between
two surface barges. In most scenarios, the vessel submerges to conduct
acoustic measurements. The static site is located at the center of Area
2.
Area 3 and Area 4. These restricted areas provide
protection to underwater cables and bottom-mounted equipment they
encompass.
Bottom-moored acoustic measurement arrays are located in the middle
of the site. These instrumented arrays are established for measuring
vessel signatures when a vessel is underway (underway site) and is at
rest and moored (static site). The instruments are passive arrays of
hydrophones sensing the acoustic signature of the vessels (i.e., the
sounds emitted when sonar units are not in operation). Hydrophones on
the arrays pick up noise in the water and transmit it to shore
facilities, where the data are processed. SEAFAC's sensitive and well-
positioned acoustic measurement equipment provides the ability to
listen to and record the

[[Page 31749]]

radiated signature of submarines, as well as other submerged manned and
unmanned vehicles, selected NOAA surface vessels, and cruise ships.
The sensors at SEAFAC are passive and measure radiated noise in the
water, such as machinery on submarines and other underwater vessels.
Vessels do not use tactical mid-frequency active sonar while undergoing
testing at SEAFAC. Active acoustic sources are used for communications,
range calibration, and to provide position information for units
operating submerged on the range.

Description of Marine Mammals in the Area of the Specified Activities

Twenty-nine marine mammal species are known to occur in the Study
Area, including seven mysticetes (baleen whales), 16 odontocetes
(dolphins and toothed whales), and six pinnipeds (seals and sea lions).
Among these species, there are 50 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.
Consistent with NMFS most recent Pacific Stock Assessment Report, a
single species may include multiple stocks recognized for management
purposes (e.g., killer whale), while other species are grouped into a
single stock due to limited species-specific information (e.g., beaked
whales belonging to the genus Mesoplodon).

Table 9--Marine Mammals With Possible or Confirmed Presence Within the NWTT Study Area
----------------------------------------------------------------------------------------------------------------
Common name Scientific name Stock Stock abundance ESA/MMPA
----------------------------------------------------------------------------------------------------------------
North Pacific right whale.... Eubalaena Eastern North 31.............. Endangered/Depleted.
japonica. Pacific.
Humpback whale............... Megaptera Central North 10,103.......... Endangered/Depleted.
novaeangliae. Pacific.
California, 1,918........... Endangered/Depleted.
Oregon, &
Washington.
Blue whale................... Balaenoptera Eastern North 1,647........... Endangered/Depleted.
musculus. Pacific.
Fin whale.................... Balaenoptera Northeast 1,214 (minimum Endangered/Depleted.
physalus. Pacific. estimate).
California, 3,051........... Endangered/Depleted.
Oregon, &
Washington.
Sei whale.................... Balaenoptera Eastern North 126............. Endangered/Depleted.
borealis. Pacific.
Minke whale.................. Balaenoptera Alaska.......... Not available...
acutorostrata.
California, 478.............
Oregon, &
Washington.
Gray whale................... Eschrichtius Eastern North 19,126..........
robustus. Pacific.
Western North 155............. Endangered/Depleted.
Pacific.
Sperm whale.................. Physeter North Pacific... Not available... Endangered/Depleted.
macrocephalus.
California, 971............. Endangered/Depleted.
Oregon, &
Washington.
Pygmy sperm whale............ Kogia breviceps. California, 579.............
Oregon, &
Washington.
Dwarf sperm whale............ Kogia sima...... California, Not available...
Oregon, &
Washington.
Killer whale................. Orcinus orca.... Alaskan Resident 2,347...........
Northern 261.............
Resident.
West Coast 243.............
Transient.
Eastern North 240.............
Pacific
Offshore.
Eastern North 85 (direct Endangered/Depleted.
Pacific count).
Southern
Resident.
Short-finned pilot whale..... Globicephala California, 760.............
macrorhynchus. Oregon, &
Washington.
Short-beaked common dolphin.. Delphinus California, 411,211.........
delphis. Oregon, &
Washington.
Bottlenose dolphin........... Tursiops California, 1,006...........
truncatus. Oregon, &
Washington
Offshore.
Striped dolphin.............. Stenella California, 10,908..........
coeruleoalba. Oregon, &
Washington.
Pacific white-sided dolphin.. Lagenorhynchus North Pacific... 26,880..........
obliquidens.
California, 26,930..........
Oregon, &
Washington.
Northern right whale dolphin. Lissodelphis California, 8,334...........
borealis. Oregon, &
Washington.
Risso's dolphin.............. Grampus griseus. California, 6,272...........
Oregon, &
Washington.
Harbor porpoise.............. Phocoena Southeast Alaska 11,146..........
phocoena.
Northern Oregon/ 21,487..........
WA Coast.
Northern CA/ 35,769..........
southern OR.
WA Inland Waters 10,682. ...........................
Alaska.......... 83,400..........
Dall's porpoise.............. Phocoenoides California, 42,000..........
dalli. Oregon, &
Washington.
Cuvier's beaked whale........ Ziphius Alaska.......... Not available...
cavirostris.
California, 6,590...........
Oregon, &
Washington.
Baird's beaked whale......... Berardius Alaska.......... Not available...
bairdii.
California, 847.............
Oregon, &
Washington.

[[Page 31750]]

Mesoplodont beaked whales \1\ Mesoplodon spp.. California, 694.............
Oregon, &
Washington.
Steller sea lion............. Eumetopias Eastern U.S..... 63,160-78,198...
jubatus.
California sea lion.......... Zalophus U.S............. 296,750.........
californianus.
Northern fur seal............ Callorhinus Eastern Pacific. 639,545......... Depleted.
ursinus.
California 12,844..........
Breeding.
Guadalupe fur seal........... Arctocephalus Mexico.......... 14,000-15,000... Threatened/Depleted.
townsendi.
Northern elephant seal....... Mirounga California 124,000.........
angustirostris. Breeding.
Harbor seal.................. Phoca vitulina.. Southeast Alaska 152,602.........
(Clarence
Strait).
OR/WA Coast..... 24,732..........
California...... 30,196..........
WA Northern 11,036..........
Inland Waters.
Southern Puget 1,568...........
Sound.
Hood Canal...... 3,555. \2\
----------------------------------------------------------------------------------------------------------------
\1\ In waters off the U.S. west coast, the Mesoplodon species M. carlhubbsi, M. ginkgodens, M. perrini, M.
peruvianus, M. stejnegeri and M. densirostris have been grouped by NMFS into a single management unit
(Mesoplodon spp.) in the 2014 Pacific Stock Assessment report (Carretta et al., 2014).
\2\ The most recent SAR (2014) divided the harbor seals within the Inland Waters into three stocks: The
Washington Northern Inland Waters stock; the Southern Puget Sound stock, and the Hood Canal stock.

Based on recent discussion with regional NMFS subject matter
experts and subsequent to the publication of the 2014 SAR, the Navy and
NMFS applied research presented in London et al. (2012) to reevaluate
the Hood Canal stock abundance. Using updated tag data from London et
al. 2012, the count of harbor seals collected in 1999 (n=711) from
aerial surveys (Jeffries et al., 2003) was corrected to account for
harbor seal haulout behavior that most closely aligned with the season
and time of day in which the original survey was conducted. The tag
data showed that during this month and time of day, approximately 80
percent of the animals would be in the water. Therefore, the corrected
Hood Canal stock abundance (based on the 1999 aerial survey) is
calculated as 711/0.20 or 711*5 = 3,555. While this aerial survey data
is considered out of date based on the standards of NOAA stock
assessment reports, this revised Hood Canal harbor seal abundance
represents the best available science based on publically available
data.
Information on the status, distribution, abundance, and
vocalizations of marine mammal species in the Study Area may be viewed
in Chapter 4 of the LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm). Further information on the general
biology and ecology of marine mammals is included in the NWTT DEIS/
OEIS. In addition, NMFS publishes annual SARs for marine mammals,
including stocks that occur within the Study Area (http://www.nmfs.noaa.gov/pr/species/mammals; Carretta et al., 2014; Allen and
Angliss, 2014).

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 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 microPascal ([micro]Pa) at 1 m. Low-

[[Page 31751]]

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).

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 from ratios of pressures; the
standard reference pressure for underwater sound is 1 [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 [micro]Pa (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. Current
data indicate that not all marine mammal species have equal hearing
capabilities (Richardson et al., 1995; Southall et al., 1997; Wartzok
and Ketten, 1999; Au and Hastings, 2008).
Southall et al. (2007) designated ``functional hearing groups'' for
marine mammals based on available behavioral data; audiograms derived
from auditory evoked potentials; anatomical modeling; and other data.
Southall et al. (2007) also estimated the lower and upper frequencies
of functional hearing for each group. However, animals are less
sensitive to sounds at the outer edges of their functional hearing
range and are more sensitive to a range of frequencies within the
middle of their functional hearing range. Note that no direct
measurements of hearing ability have been successfully completed for
low-frequency cetaceans. The functional groups and the associated
frequencies are indicated below (note that these frequency ranges
correspond to the range for the composite group, with the entire range
not necessarily reflecting the capabilities of every species within
that group):
Low frequency cetaceans (13 species of mysticetes):
Functional hearing estimates occur between approximately 7 Hz and 30
kilohertz (kHz) (extended from 22 kHz based on data indicating that
some mysticetes can hear above 22 kHz; Watkins, 1986; Ketten, 1998;
Houser et al., 2001; Au et al., 2006; Lucifredi and Stein, 2007; Ketten
et al., 2007; Parks et al., 2007a; Ketten and Mountain, 2009; Tubelli
et al., 2012);
Mid-frequency cetaceans (larger toothed whales, beaked
whales, and most delphinids): Functional hearing is estimated to occur
between approximately 150 Hz and 160 kHz, with best hearing from 10 to
less than 100 kHz (Johnson, 1967; White, 1977; Richardson et al., 1995;
Szymanski et al., 1999; Kastelein et al., 2003; Finneran et al., 2005a,
2009; Nachtigall et al., 2005, 2008; Yuen et al., 2005;

[[Page 31752]]

Popov et al., 2007; Au and Hastings, 2008; Houser et al., 2008; Pacini
et al., 2010, 2011; Schlundt et al., 2011);
High-frequency cetaceans (porpoises, river dolphins, and
members of the genera Kogia and Cephalorhynchus; including two members
of the genus Lagenorhynchus, including the hourglass dolphin, on the
basis of recent echolocation data and genetic data [May-Collado and
Agnarsson, 2006; Kyhn et al., 2009, 2010; Tougaard et al., 2010]):
Functional hearing is estimated to occur between approximately 200 Hz
and 180 kHz (Popov and Supin, 1990a,b; Kastelein et al., 2002; Popov et
al., 2005); and
Pinnipeds in water; Phocidae (true seals): Functional
hearing is estimated to occur between approximately 75 Hz to 100 kHz,
with best hearing between 1-50 kHz (M[oslash]hl, 1968; Terhune and
Ronald, 1971, 1972; Richardson et al., 1995; Kastak and Schusterman,
1999; Reichmuth, 2008; Kastelein et al., 2009);
Pinnipeds in water; Otariidae (eared seals): Functional
hearing is estimated to occur between 100 Hz and 40 kHz for Otariidae,
with best hearing between 2-48 kHz (Schusterman et al., 1972; Moore and
Schusterman, 1987; Babushina et al., 1991; Richardson et al., 1995;
Kastak and Schusterman, 1998; Kastelein et al., 2005a; Mulsow and
Reichmuth, 2007; Mulsow et al., 2011a, b).
The pinniped functional hearing group was modified from Southall et
al. (2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids, especially in the higher frequency range
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth et al.,
2013).
Concurrent with the development of NOAA's Ocean Noise Strategy and
draft ``Guidance for Assessing the Effects of Anthropogenic Sound on
Marine Mammals,'' NMFS is currently considering additional
modifications to some of the functional hearing ranges proposed by
Southall et al. (2007). As more data from more species and/or
individuals become available, these estimated hearing ranges may
require additional modifications.
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.

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 + 10 log (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 January 2014 NWTT 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 vessel strikes.

[[Page 31753]]

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.
This section focuses 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, the potential effects to marine mammals
from non-impulsive and impulsive sources will be related to the MMPA
definitions of Level A and Level B harassment, along with the potential
effects from vessel strikes, and we will 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
could 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 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

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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 one 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. Recent research with ex vivo supersaturated bovine
tissues suggested that, for a 37 kHz signal, a sound exposure of
approximately 215 dB referenced to (re) 1 [mu]Pa would be required
before microbubbles became destabilized and grew (Crum et al., 2005).
Assuming spherical spreading loss and a nominal sonar source level of
235 dB re 1 [mu]Pa at 1 m, a whale would need to be within 10 m (33
ft.) of the sonar dome to be exposed to such sound levels. Furthermore,
tissues in the study were supersaturated by exposing them to pressures
of 400-700 kilopascals for periods of hours and then releasing them to
ambient pressures. Assuming the equilibration of gases with the tissues
occurred when the tissues were exposed to the high pressures, levels of
supersaturation in the tissues could have been as high as 400-700
percent. These levels of tissue supersaturation are substantially
higher than model predictions for marine mammals (Houser et al., 2001;
Saunders et al., 2008). It is improbable that this mechanism is
responsible for stranding events or traumas associated with beaked
whale strandings. Both the degree of supersaturation and exposure
levels observed to cause microbubble destabilization are unlikely to
occur, either alone or in concert.
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;
Fern[aacute]ndez et al., 2012). 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, 2012) 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 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).

[[Page 31755]]

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 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'' (Seyle, 1950) or ``allostatic
loading'' (McEwen and Wingfield, 2003). This pathological state will
last until the animal replenishes its biotic

[[Page 31756]]

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; 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

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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). However, Miller et al. (2009) reported buzz
rates (a proxy for feeding) 19 percent lower during exposure to distant
signatures of seismic airguns. 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. Blue whales exposed to simulated mid-frequency sonar in the
Southern California Bight were less likely to produce low frequency
calls usually associated with feeding behavior (Melc[oacute]n et al.,
2012). It is not known whether the lower rates of calling actually
indicated a reduction in feeding behavior or social contact since the
study used data from remotely deployed, passive acoustic monitoring
buoys. In contrast, blue whales increased their likelihood of calling
when ship noise was present, and decreased their likelihood of calling
in the presence of explosive noise, although this result was not
statistically significant (Melc[oacute]n et al., 2012). Additionally,
the likelihood of an animal calling decreased with the increased
received level of mid-frequency sonar, beginning at a SPL of
approximately 110-120 dB re 1 [micro]Pa (Melc[oacute]n et al., 2012).
Preliminary results from the 2010-2011 field season of an ongoing
behavioral response study in Southern California waters indicated that,
in some cases and at low received levels, tagged blue whales responded
to mid-frequency sonar but that those responses were mild and there was
a quick return to their baseline activity (Southall et al., 2011). 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. Goldbogen et al., (2013) monitored behavioral responses
of tagged blue whales located in feeding areas when exposed simulated
MFA sonar. Responses varied depending on behavioral context, with deep
feeding whales being more significantly affected (i.e., generalized
avoidance; cessation of feeding; increased swimming speeds; or directed
travel away from the source) compared to surface feeding individuals
that typically showed no change in behavior. Non-feeding whales also
seemed to be affected by exposure. The authors indicate that disruption
of feeding and displacement could impact individual fitness and health.
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

[[Page 31758]]

(Kastelein et al., 2001; Kastelein et al., 2006a) and emissions for
underwater data transmission (Kastelein et al., 2005). However,
exposure of the same 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 (Southall et al.,
2007; Henderson et al., 2014).
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; NOAA, 2014b). 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
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

[[Page 31759]]

respond to the specific sound signatures. Instead, they may be
sensitive to any pulsed sound from a point source in this frequency
range. The response to such stimuli appears to involve maximizing the
distance from the sound source.
Stimpert et al. (2014) tagged a Baird's beaked whale, which was
subsequently exposed to simulated mid-frequency sonar. Changes in the
animal's dive behavior and locomotion were observed when received level
reached 127 dB re1[mu]Pa.
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; Southall et al. 2009; 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. Results from a similar behavioral response study in southern
California waters have been presented for the 2010-2011 field season
(Southall et al. 2011; DeRuiter et al., 2013b). DeRuiter et al. (2013b)
presented results from two Cuvier's beaked whales that were tagged and
exposed to simulated mid-frequency active sonar during the 2010 and
2011 field seasons of the southern California behavioral response
study. The 2011 whale was also incidentally exposed to mid-frequency
active sonar from a distant naval exercise. Received levels from the
mid-frequency active sonar signals from the controlled and incidental
exposures were calculated as 84-144 and 78-106 dB re 1 [micro]Pa root
mean square (rms), respectively. Both whales showed responses to the
controlled exposures, ranging from initial orientation changes to
avoidance responses characterized by energetic fluking and swimming
away from the source. However, the authors did not detect similar
responses to incidental exposure to distant naval sonar exercises at
comparable received levels, indicating that context of the exposures
(e.g., source proximity, controlled source ramp-up) may have been a
significant factor. 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).
In the 2007-2008 Bahamas study, playback sounds of a potential
predator--a killer whale--resulted in a similar but more pronounced
reaction, which included longer inter-dive intervals and a sustained
straight-line departure of more than 20 km from the area. The authors
noted, however, that the magnified reaction to the predator sounds
could represent a cumulative effect of exposure to the two sound types
since killer whale playback began approximately 2 hours after mid-
frequency source playback. Pilot whales and killer whales off Norway
also exhibited horizontal avoidance of a transducer with outputs in the
mid-frequency range (signals in the 1-2 kHz and 6-7 kHz ranges) (Miller
et al., 2011). Additionally, separation of a calf from its group during
exposure to mid-frequency sonar playback was observed on one occasion
(Miller et al., 2011). In contrast, preliminary analyses suggest that
none of the pilot whales or false killer whales in the Bahamas showed
an avoidance response to controlled exposure playbacks (Southall et
al., 2009).
Through analysis of the behavioral response studies, a preliminary
overarching effect of greater sensitivity to all anthropogenic
exposures was seen in beaked whales compared to the other odontocetes
studied (Southall et al., 2009). Therefore, recent studies have focused
specifically on beaked whale responses to active sonar transmissions or
controlled exposure playback of simulated sonar on various military
ranges (Defence Science and Technology Laboratory, 2007; Claridge and
Durban, 2009; Moretti et al., 2009; McCarthy et al., 2011; Tyack et
al., 2011). In the Bahamas, Blainville's beaked whales located on the
range will move off-range during sonar use and return only after the
sonar transmissions have stopped, sometimes taking several days to do
so (Claridge and Durban 2009; Moretti et al., 2009; McCarthy et al.,
2011; Tyack et al., 2011). Moretti et al. (2014) used recordings from
seafloor-mounted hydrophones at the Atlantic Undersea Test and
Evaluation Center (AUTEC) to analyze the probability of Blainsville's
beaked whale dives before, during, and after Navy sonar exercises.
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

[[Page 31760]]

limited) responses to received levels in the 90 to 120 dB re: 1 [mu]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.

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 limited 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 10\3\kJ/minute), and spent energy fleeing or
acting aggressively toward hikers (White

[[Page 31761]]

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.
Lusseau and Bejder (2007) present data from three long-term studies
illustrating the connections between disturbance from whale-watching
boats and population-level effects in cetaceans. In Sharks Bay
Australia, the abundance of bottlenose dolphins was compared within
adjacent control and tourism sites over three consecutive 4.5-year
periods of increasing tourism levels. Between the second and third time
periods, in which tourism doubled, dolphin abundance decreased by 15
percent in the tourism area and did not change significantly in the
control area. In Fiordland, New Zealand, two populations (Milford and
Doubtful Sounds) of bottlenose dolphins with tourism levels that
differed by a factor of seven were observed and significant increases
in travelling time and decreases in resting time were documented for
both. Consistent short-term avoidance strategies were observed in
response to tour boats until a threshold of disturbance was reached
(average 68 minutes between interactions), after which the response
switched to a longer term habitat displacement strategy. For one
population tourism only occurred in a part of the home range, however,
tourism occurred throughout the home range of the Doubtful Sound
population and once boat traffic increased beyond the 68-minute
threshold (resulting in abandonment of their home range/preferred
habitat), reproductive success drastically decreased (increased
stillbirths) and abundance decreased significantly (from 67 to 56
individuals in short period). Last, in a study of northern resident
killer whales off Vancouver Island, exposure to boat traffic was shown
to reduce foraging opportunities and increase traveling time. A simple
bioenergetics model was applied to show that the reduced foraging
opportunities equated to a decreased energy intake of 18 percent, while
the increased traveling incurred an increased energy output of 3-4
percent, which suggests that a management action based on avoiding
interference with foraging might be particularly effective.
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). Note that there is a difference between multiple-day
substantive behavioral reactions and multiple-day anthropogenic
activities. For example, just because an at-sea exercise lasts for
multiple days does not necessarily mean that individual animals are
either exposed to that exercise for multiple days or, further, exposed
in a manner resulting in a sustained multiple day substantive
behavioral responses.
In order to understand how the effects of activities may or may not
impact stocks and populations of marine mammals, it is necessary to
understand not only what the likely disturbances are going to be, but
how those disturbances may affect the reproductive success and
survivorship of individuals, and then how those impacts to individuals
translate to population changes. Following on the earlier work of a
committee of the U.S. National Research Council (NRC, 2005), New et al.
(2014), in an effort termed the Potential Consequences of Disturbance
(PCoD), outline an updated conceptual model of the relationships
linking disturbance to changes in behavior and physiology, health,
vital rates, and population dynamics (below). As depicted, behavioral
and physiological changes can either have direct (acute) effects on
vital rates, such as when changes in habitat use or increased stress
levels raise the probability of mother-calf separation or predation, or
they can have indirect and long-term (chronic) effects on vital rates,
such as when changes in time/energy budgets or increased disease
susceptibility affect health, which then affects vital rates (New et
al., 2014).
In addition to outlining this general framework and compiling the
relevant literature that supports it, New et al. (2014) have chosen
four example species for which extensive long-term monitoring data
exist (southern elephant seals, North Atlantic right whales, Ziphidae
beaked whales, and bottlenose dolphins) and developed state-space
energetic models that can be used to effectively forecast longer-term,
population-level impacts from behavioral changes. While these are very
specific models with very specific data requirements that cannot yet be
applied broadly to project-specific risk assessments, they are a
critical first step.

Stranding and Mortality

When a live or dead marine mammal swims or floats onto shore and
becomes ``beached'' or incapable of returning to sea, the event is
termed a ``stranding'' (Geraci et al., 1999; Perrin and Geraci, 2002;
Geraci and Lounsbury, 2005; 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 pre-
dispose 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,

[[Page 31762]]

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), NMFS 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 towards 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),
was associated with exercises conducted by the U.S. Navy. Most
recently, the Independent Scientific Review Panel investigating
potential contributing factors to a 2008 mass stranding of melon-headed
whales in Antsohihy, Madagascar released its final report suggesting
that the stranding was likely initially triggered by an industry
seismic survey. This report suggests that the operation of a commercial
high-powered 12 kHz multi-beam echosounder during an industry seismic
survey was a plausible and likely initial trigger that caused a large
group of melon-headed whales to leave their typical habitat and then
ultimately strand as a result of secondary factors such as
malnourishment and dehydration. The report indicates that the risk of
this particular convergence of factors and ultimate outcome is likely
very low, but recommends that the potential be considered in
environmental planning. Because of the association between tactical
mid-frequency active sonar use and a small number of marine mammal
strandings, the Navy and NMFS have been considering and addressing the
potential for strandings in association with Navy activities for years.
In addition to a suite of mitigation intended to more broadly minimize
impacts to marine mammals, the Navy and NMFS have a detailed Stranding
Response Plan that outlines reporting, communication, and response
protocols intended both to minimize the impacts of, and enhance the
analysis of, any potential stranding in areas where the Navy operates.
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

[[Page 31763]]

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 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

[[Page 31764]]

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; Fern[aacute]ndez et al.,
2012).
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 it is not known 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 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

[[Page 31765]]

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, NMFS 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.
Since that time there have been two ``out of habitat'' or ``near mass
strandings'' of melon-headed whales in the Philippines (Aragones et
al., 2010). Pictures of one of these events depict grouping behavior
like that displayed at Hanalei Bay in July 2004. No naval sonar
activity was noted it the area, although it was suspected by the
authors, based on personal communication with a government fisheries
representative, that dynamite blasting in the area may have occurred
within the days prior to one of the events (Aragones et al., 2010).
Although melon-headed whales entering embayments may be infrequent and
rare, there is precedent for this type of occurrence on other occasions
in the absence of naval activity.
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 (these later died). 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 beaked whales have been the most

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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, NMFS 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; Fern[aacute]ndez et al., 2012) 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

[[Page 31767]]

that nitrogen bubble formation was predicted to occur. However,
inspection of the vascular system of the dolphin via ultrasound did not
demonstrate the formation of asymptomatic nitrogen gas bubbles (Houser
et al., 2007). 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 susceptible 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, NMFS still anticipates 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.
Baleen whales have shown a variety of responses to impulse sound
sources, including avoidance, reduced surface intervals, altered
swimming behavior, and changes in vocalization rates (Richardson et
al., 1995; Gordon et al., 2003; Southall, 2007). While most bowhead
whales did not show active avoidance until within 8 km of seismic
vessels (Richardson et al., 1995), some whales avoided vessels by more
than 20 km at received levels as low as 120 dB re 1 [mu]Pa rms.
Additionally, Malme et al. (1988) observed clear changes in diving and
respiration patterns in bowheads at ranges up to 73 km from seismic
vessels, with received levels as low as 125 dB re 1 [mu]Pa.
Gray whales migrating along the U.S. west coast showed avoidance
responses to seismic vessels by 10 percent of animals at 164 dB re 1
[mu]Pa, and by 90 percent of animals at 190 dB re 1 [mu]Pa, with
similar results for whales in the Bering Sea (Malme 1986, 1988). In
contrast, noise from seismic surveys was not found to impact feeding
behavior or exhalation rates while resting or diving in western gray
whales off the coast of Russia (Yazvenko et al., 2007; Gailey et al.,
2007).

[[Page 31768]]

Humpback whales showed avoidance behavior at ranges of 5-8 km from
a seismic array during observational studies and controlled exposure
experiments in western Australia (McCauley, 1998; Todd et al., 1996)
found no clear short-term behavioral responses by foraging humpbacks to
explosions associated with construction operations in Newfoundland, but
did see a trend of increased rates of net entanglement and a shift to a
higher incidence of net entanglement closer to the noise source.
Seismic pulses at average received levels of 131 dB re 1
micropascal squared second ([mu]Pa\2\-s) caused blue whales to increase
call production (Di Iorio and Clark, 2010). In contrast, McDonald et
al. (1995) tracked a blue whale with seafloor seismometers and reported
that it stopped vocalizing and changed its travel direction at a range
of 10 km from the seismic vessel (estimated received level 143 dB re 1
[mu]Pa peak-to-peak). These studies demonstrate that even low levels of
noise received far from the noise source can induce behavioral
responses.
Madsen et al. (2006) and Miller et al. (2009) tagged and monitored
eight sperm whales in the Gulf of Mexico exposed to seismic airgun
surveys. Sound sources were from approximately 2 to 7 nm away from the
whales and based on multipath propagation received levels were as high
as 162 dB SPL re 1 [mu]Pa with energy content greatest between 0.3 and
3.0 kHz (Madsen, 2006). The whales showed no horizontal avoidance,
although the whale that was approached most closely had an extended
resting period and did not resume foraging until the airguns had ceased
firing (Miller et al., 2009). The remaining whales continued to execute
foraging dives throughout exposure; however, swimming movements during
foraging dives were 6 percent lower during exposure than control
periods, suggesting subtle effects of noise on foraging behavior
(Miller et al., 2009). Captive bottlenose dolphins sometimes vocalized
after an exposure to impulse sound from a seismic watergun (Finneran et
al., 2010a).
A review of behavioral reactions by pinnipeds to impulse noise can
be found in Richardson et al. (1995) and Southall et al. (2007).
Blackwell et al. (2004) observed that ringed seals exhibited little or
no reaction to pipe-driving noise with mean underwater levels of 157 dB
re 1 [mu]Pa rms and in air levels of 112 dB re 20 [mu]Pa, suggesting
that the seals had habituated to the noise. In contrast, captive
California sea lions avoided sounds from an impulse source at levels of
165-170 dB re 1 [mu]Pa (Finneran et al., 2003b). Experimentally,
G[ouml]tz and Janik (2011) tested underwater, startle responses to a
startling sound (sound with a rapid rise time and a 93 dB sensation
level [the level above the animal's threshold at that frequency]) and a
non-startling sound (sound with the same level, but with a slower rise
time) in wild-captured gray seals. The animals exposed to the startling
treatment avoided a known food source, whereas animals exposed to the
non-startling treatment did not react or habituated during the exposure
period. The results of this study highlight the importance of the
characteristics of the acoustic signal in an animal's response of
habituation.

Vessels

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 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 and also appear to
increase the chance of severe injuries or death. While modeling studies
have suggested that hydrodynamic forces pulling whales toward the
vessel hull increase with increasing speed (Clyne, 1999; Knowlton et
al., 1995), this is inconsistent with Silber et al. (2010), which
demonstrated that there is no such relationship (i.e., hydrodynamic
forces are independent of speed).
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).
There are no records of any Navy vessel strikes to marine mammals
during training or testing activities in the NWTT Study Area. There has
been only one whale strike in the Pacific Northwest by the Navy since
such records have been kept (June 1994-present). In August 2012, a San
Diego homeported DDG (destroyer) at-sea about 35 nm west of Coos Bay,
Oregon struck a whale (believed to be a minke) while transiting to San
Diego from Seattle. There have been Navy strikes of large whales in
areas outside the Study Area, such as Hawaii and Southern California.
However, these areas differ significantly from the Study Area given
that both Hawaii and Southern

[[Page 31769]]

California have a much higher number of Navy vessel activities.
Other efforts have been undertaken to investigate the impact from
vessels (both whale-watching and general vessel traffic noise) and
demonstrated impacts do occur (Bain, 2002; Erbe, 2002; Lusseau, 2009;
Williams et al., 2006, 2009, 2011b, 2013, 2014a, 2014b; Noren et al.,
2009; Read et al., 2014; Rolland et al., 2012; Pirotta et al., 2015).
This body of research for the most part has investigated impacts
associated with the presence of chronic stressors, which differ
significantly from generally intermittent Navy training and testing
activities. For example, in an analysis of energy costs to killer
whales, Williams et al. (2009) suggested that whale-watching in the
Johnstone Strait resulted in lost feeding opportunities due to vessel
disturbance, which could carry higher costs than other measures of
behavioral change might suggest. Ayres et al. (2012) recently reported
on research in the Salish Sea involving the measurement of southern
resident killer whale fecal hormones to assess two potential threats to
the species recovery: Lack of prey (salmon) and impacts to behavior
from vessel traffic. Ayres et al. (2012) suggested that the lack of
prey overshadowed any population-level physiological impacts on
southern resident killer whales from vessel traffic.

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 January 2014 NWTT 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 January 2014 NWTT 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.

Critical Habitat

The southern resident killer whale (in the inshore area) is the
only ESA-listed marine mammal species with designated critical habitat
located in the Study Area. The majority of the Navy's proposed training
and testing activities would, however, not occur in the southern
resident killer whale's designated critical habitat (NMFS, 2006). For
all substressors that would occur within the critical habitat, those
training and testing activities are not expected to impact the
identified primary constituent elements of that habitat and therefore
would have no effect on that critical habitat. Effects to designated
critical habitat will be fully analyzed in the Navy's and NMFS'
internal ESA Section 7 consultations for NWTT.

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. 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 move
relatively rapidly 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 NWTT Study Area.

Effects on Marine Mammal Prey

Invertebrates--Marine invertebrate distribution in the NWTT 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 Study Area inhabit coastal waters and
benthic habitats, including salt marshes, kelp forests, soft sediments,
canyons, and the continental shelf. Salt marsh invertebrates include
oysters, crabs, and worms that are important prey for birds and small
mammals. Mudflats provide habitat for substantial amounts of
crustaceans, bivalves, and worms. The sandy intertidal area is
dominated by species that are highly mobile and can burrow. One of the
most abundant invertebrates found in the near shore areas of the Study
Area on soft sediments are geoduck clams (Panopea generosa).
All marine invertebrate taxonomic groups are represented in the
NWTT Study Area. Major invertebrate phyla (taxonomic range)--those with
greater than 1,000 species and the general zones they inhabit in the
Study Area are described in Chapter 3 of the January 2014 NWTT DEIS/
OEIS.
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 31770]]

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 NWTT 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). The
movements of some open-ocean species may never overlap with coastal
fishes that spend their lives within several hundred feet (a few
hundred meters) of the shore. Even within a single fish species, the
distribution and specific habitats in which individuals occur may be
influenced by its developmental stage, size, sex, reproductive
condition, and other factors.
The distribution and abundance of fishes depends greatly on the
physical and biological factors of the marine ecosystem, such as
salinity, temperature, dissolved oxygen, population dynamics, predator
and prey interaction oscillations, seasonal movements, reproduction and
life cycles, and recruitment success (Helfman et al., 1997). A single
factor is rarely responsible for the distribution of fish species; more
often, a combination of factors is accountable. For example, open ocean
species optimize their growth, reproduction, and survival by tracking
gradients of temperature, oxygen, or salinity (Helfman et al., 1997).
Another major component in understanding species distribution is the
location of highly productive regions, such as frontal zones. These
areas concentrate various prey species and their predators, such as
tuna, and provide visual cues for the location of target species for
commercial fisheries (NMFS, 2001).
There are 17 major taxonomic groups of marine fishes within the
NWTT Study Area. Detailed information on taxa presence, distribution,
and characteristics are provided in Chapter 3 of the January 2014 NWTT
DEIS/OEIS.
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 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

[[Page 31771]]

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 January 2014 NWTT 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 NWTT 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.

Proposed 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.'' NMFS' duty under this ``least
practicable adverse impact'' standard is to prescribe mitigation
reasonably designed to minimize, to the extent practicable, any adverse
population-level impacts, as well as habitat impacts. While population-
level impacts can be minimized by reducing impacts on individual marine
mammals, not all takes translate to population-level impacts. NMFS'
primary objective under the ``least practicable adverse impact''
standard is to design mitigation targeting those impacts on individual
marine mammals that are most likely to lead to adverse population-level
effects.
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 LOA application are considered military readiness
activities.
NMFS reviewed the proposed activities and the proposed mitigation
measures as described in the 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.
NMFS worked with the Navy to develop these proposed measures, and they
are informed by years of experience and monitoring. In addition, the
adaptive management process (see Adaptive management) and annual
meetings between NMFS and the Navy 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 measures should be refined or modified.
The 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)

[[Page 31772]]

those positioned ashore, 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 manning and space restrictions on aircraft, small boats, and
some Navy ships, Lookouts for these platforms may be supplemented by
the aircraft crew or pilot, boat crew, range site personnel, or shore-
side personnel. Lookouts positioned in minimally manned platforms may
be responsible for tasks in addition to observing the air or surface of
the water (e.g., navigation of a helicopter or small boat). However,
all Lookouts will (considering personnel safety, practicality of
implementation, and impact on the effectiveness of the activity) comply
with the observation objectives described above for Lookouts positioned
on ships.
The procedural measures described below primarily consist of having
Lookouts during specific training and testing activities.
All personnel standing watch on the bridge, Commanding Officers,
Executive Officers, maritime patrol aircraft aircrews,
anti[hyphen]submarine warfare helicopter crews, civilian equivalents,
and Lookouts will successfully complete the United States Navy Marine
Species Awareness Training prior to standing watch or serving as a
Lookout. Additional details on the Navy's Marine Species Awareness
Training can be found in the NWTT Draft EIS/OEIS.
The Navy proposes to use one or more Lookouts during the training
and testing activities provided in Table 10. Additional details on
Lookout procedures and implementation are provided in Chapter 11 of the
LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm).

Table 10--Lookout Mitigation Measures for Training and Testing
Activities Within the NWTT Study Area
------------------------------------------------------------------------
Number of lookouts Training and testing activities
------------------------------------------------------------------------
1-2................................ Low-Frequency and Non-Hull Mounted
Mid-Frequency Active Sonar.
1.................................. High-Frequency and Hull Mounted Mid-
Frequency Active Sonar.
1.................................. Improved Extended Echo Ranging
Sonobuoys (testing only).
1.................................. Explosive Signal Underwater Sound
Buoys Using >0.5-2.5 Pound Net
Explosive Weight.
2.................................. Mine Countermeasures and
Neutralization Activities Using
Positive Control Firing Devices
(training only).
1-2................................ Gunnery Exercises Using Surface
Target (training only).
1.................................. Missile Exercises Using Surface
Target (training only).
1 (minimum)........................ Bombing Exercises--Explosive
(training only).
1.................................. Torpedo--Explosive (testing
only).\1\
1.................................. Weapons Firing Noise During Gunnery
Exercises (training only).
1 (minimum)........................ Vessel Movement.
1.................................. Towed In-Water Strike.
1.................................. Gunnery Exercises--Non-Explosive
(training only).
1.................................. Bombing Exercises--Non-Explosive
(training only).
------------------------------------------------------------------------
\1\ For explosive torpedo tests from aircraft, the Navy will have one
Lookout positioned in an aircraft; for explosive torpedoes tested from
a surface ship, the Navy is proposing to use the Lookout procedures
currently implemented for hull-mounted mid-frequency active sonar
activities.

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 previous authorizations for the Atlantic Fleet
Training and Testing Study Area; the Hawaii-Southern California
Training and Testing Study Area; and the Determination of Acoustic
Effects on Marine Mammals and Sea Turtles for the Northwest Training
and Testing EIS/OEIS technical report (Marine Species Modeling Team,
2013).
As a result of the updates to the acoustic propagation modeling, in
some cases the ranges to onset of TTS effects are much larger than
previous model outputs. Due to the ineffectiveness and unacceptable
operational impacts associated with mitigating these large areas, the
Navy is unable to mitigate for onset of TTS for every activity. For the
NWTT analysis, the Navy developed each recommended mitigation zone to
avoid or reduce the potential for onset of the lowest level of injury,
PTS, out to the predicted maximum range. In some cases where the ranges
to effects are smaller than previous models estimated, the mitigation
zones were adjusted accordingly to provide consistency across the
measures. Mitigating to the predicted maximum range to PTS consequently
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 consequently covers the
predicted average range to TTS. Table 11 summarizes 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. The predicted ranges are
based on local environmental conditions and are unique to the NWTT
Study Area.
The Navy's proposed mitigation zones are based on the longest range
for all the

[[Page 31773]]

marine mammal and sea turtle functional hearing groups. Most mitigation
zones were driven by the high-frequency cetacean or sea turtle
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 LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm).

Table 11--Predicted Ranges to TTS, PTS, and Recommended Mitigation Zones for Each Activity Category
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bin (representative Predicted average Predicted average Predicted maximum Recommended mitigation
Activity category source) \1\ range to TTS range to PTS range to PTS zone
--------------------------------------------------------------------------------------------------------------------------------------------------------
Non-Impulsive Sound
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-Frequency and Hull-Mounted Mid- SQS-53 ASW hull- 4,251 yd. (3,887 m).. 281 yd. (257 m)...... <292 yd. (<267 m).... Training: 1,000 yd.
Frequency Active Sonar.\2\ mounted sonar (MF1). (920 m) and 500 yd.
(460 m) power downs
and 200 yd. (180 m)
shutdown for
cetaceans, 100 yd.
(90 m) mitigation
zone for pinnipeds.
Testing: 1,000 yd.
(920 m) and 500 yd.
(460 m) power downs
for sources that can
be powered down and
200 yd. (180 m)
shutdown for
cetaceans, 100 yd.
(90 m) for pinnipeds
(excludes haulouts).
High-Frequency and Non-Hull-Mounted AQS-22 ASW dipping 226 yd. (207 m)...... <55 yd. (<50 m)...... <55 yd. (<50 m)...... Training: 200 yd. (180
Mid-Frequency Active Sonar.\2\ sonar (MF4). m).
Testing: 200 yd. (180
m) for cetaceans, 100
yd. (90 m) for
pinnipeds (excludes
haulouts).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Explosive and Impulsive Sound
--------------------------------------------------------------------------------------------------------------------------------------------------------
Improved Extended Echo Ranging Explosive sonobuoy 237 yd. (217 m)...... 133 yd. (122 m)...... 235 yd. (215 m)...... Training: n/a
Sonobuoys. (E4). Testing: 600 yd. (550
m) for marine
mammals, sea turtles,
and concentrations of
floating vegetation.
Signal Underwater Sound (SUS) buoys Explosive sonobuoy 178 yd. (163 m)...... 92 yd. (84 m)........ 214 yd. (196 m)...... Training: 350 yd. (320
using >0.5-2.5 lb. NEW. (E3). m) for marine
mammals, sea turtles,
and concentrations of
floating vegetation.
Testing: 350 yd. (320
m) for marine
mammals, sea turtles,
and concentrations of
floating vegetation.
Mine Countermeasure and >0.5 to 2.5 lb NEW 495 yd. (453 m)...... 145 yd. (133 m)...... 373 yd. (341 m)...... Training: 400 yd. (336
Neutralization Activities (E3). m).
(positive control). Testing: n/a.
Gunnery Exercises--Small- and 25 mm projectile (E1). 72 yd. (66 m)........ 48 yd. (44 m)........ 73 yd. (67 m)........ Training: 200 yd. (180
Medium-Caliber (Surface Target). m).
Testing: n/a.
Gunnery Exercises--Large-Caliber 5 in. projectiles (E5 210 yd. (192 m)...... 110 yd. (101 m)...... 177 yd. (162 m)...... Training: 600 yd. (550
(Surface Target). at the surface).\3\ m).
Testing: 600 yd. (550
m).
Missile Exercises up to 500 lb. NEW Harpoon missile (E10). 1,164 yd. (1,065 m).. 502 yd. (459 m)...... 955 yd. (873 m)...... Training: 2,000 yd.
(Surface Target). (1.8 km).
Testing: n/a.
Bombing Exercises.................. MK-84 2,000 lb. bomb 1,374 yd. (1,256 m).. 591 yd. (540 m)...... 1,368 yd. (1,251 m).. Training: 2,500 yd.
(E12). (2.3 km).
Testing: n/a.
Lightweight Torpedo (Explosive) MK-46 torpedo (E8).... 497 yd. (454 m)...... 245 yd. (224 m)...... 465 yd. (425 m)...... Training: n/a.
Testing. Testing: 2,100 yd.
(1.9 km).
Heavyweight Torpedo (Explosive) MK-48 torpedo (E11)... 1,012 yd. (926 m).... 472 yd. (432 m)...... 885 yd. (809 m)...... Training: n/a.
Testing. Testing: 2,100 yd.
(1.9 km).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ 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.
\2\ High-frequency and non-hull-mounted mid-frequency active sonar category includes unmanned underwater vehicle and torpedo testing activities.
\3\ The representative source Bin E5 has different range to effects depending on the depth of activity occurrence (at the surface or at various depths).
Notes: ASW = anti-submarine warfare, in. = inch, km = kilometer, m = meter, mm = millimeter, n/a = Not Applicable, NEW = net explosive weight, PTS =
permanent threshold shift, TTS = temporary threshold shift, yd. = yard.

[[Page 31774]]

Low-Frequency and Hull-Mounted Mid-Frequency Active Sonar Training

There are no low-frequency active sonar training activities
proposed in the Study Area. The Navy is proposing to (1) continue
implementing the current measures for mid-frequency active sonar, (2)
clarify the conditions needed to recommence an activity after a
sighting, and (3) implement mitigation measures for pinnipeds and for
pierside sonar testing in the vicinity of hauled out pinnipeds.
Activities that involve the use of hull-mounted mid-frequency
active sonar (including pierside) will use Lookouts for visual
observation from a ship immediately before and during the activity.
Mitigation zones for these activities involve powering down the sonar
by 6 dB when a marine mammal is sighted within 1,000 yd. (920 m) of the
sonar dome, and by an additional 4 dB when sighted within 500 yd. (460
m) from the source, for a total reduction of 10 dB. Active
transmissions will cease if a marine mammal is sighted within 200 yd.
(180 m). Active transmission will recommence if any one of the
following conditions is 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, (4) the ship has transited more than 2,000 yd. (1.8 km) beyond
the location of the last sighting, or (5) the Lookout concludes that
dolphins are deliberately closing in on the ship to ride the ship's bow
wave (and there are no other marine mammal sightings within the
mitigation zone). Active transmission may resume when dolphins are bow
riding because they are out of the main transmission axis of the active
sonar while in the shallow-wave area of the ship bow.
For pinnipeds, the Navy proposes a 100 yd. (90 m) mitigation zone
for activities that involve the use of hull-mounted mid-frequency
active sonar. The pinniped mitigation zone does not apply for pierside
testing in the vicinity of pinnipeds hauled out on man-made structures
and vessels. Within Puget Sound there are several locations where
pinnipeds use Navy structures (e.g., submarines, security barriers) for
haulouts in spite of the degree of activity surrounding these sites.
Given that animals continue to choose these areas for their resting
behavior, it would appear there are no long-term effects or
consequences to those animals as a result of ongoing and routine Navy
activities.
Testing
There are no current hull-mounted mid-frequency active sonar
testing activities in the Study Area, and no mitigation procedures.
However, the Navy's Proposed Action includes newly assessed hull-
mounted mid-frequency active sonar testing activities. For testing
activities, the recommended measures are provided below.
Activities that involve the use of low-frequency active sonar
(including pierside) will use Lookouts for visual observation
immediately before and during the event. If a marine mammal is sighted
within 200 yd. (180 m) of the sound source, active transmissions will
cease. Active transmission will recommence if any one of the following
conditions is 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
sound source has transited more than 2,000 yd. (1.8 km) beyond the
location of the last sighting.
Activities that involve the use of hull-mounted mid-frequency
active sonar (including pierside and shore-based testing) will follow
the mitigation measures described above for Low-Frequency and Hull-
Mounted Mid-Frequency Active Sonar Training.
For pinnipeds, the Navy proposes a 100 yd. mitigation zone. The
pinniped mitigation zone does not apply for pierside testing in the
vicinity of pinnipeds hauled out on man-made structures and vessels.

High-Frequency and Non-Hull-Mounted Mid-Frequency Active Sonar Training

Non-hull-mounted mid-frequency active sonar training activities
include the use of aircraft deployed sonobuoys and helicopter dipping
sonar. The Navy is proposing to: (1) Continue implementing the current
mitigation measures for activities currently being executed, such as
dipping sonar activities; (2) extend the implementation of its current
mitigation to all other activities in this category; and (3) clarify
the conditions needed to recommence an activity after a sighting.
Mitigation will include visual observation from a vessel or
aircraft (with the exception of platforms operating at high altitudes)
immediately before and during active transmission within a mitigation
zone of 200 yd. (180 m) from the active sonar source. For activities
involving helicopter deployed dipping sonar, visual observation will
commence 10 minutes before the first deployment of active dipping
sonar. Helicopter dipping and sonobuoy deployment will not begin if
concentrations of floating vegetation (kelp paddies), are observed in
the mitigation zone. If the source can be turned off during the
activity, active transmission will cease if a marine mammal is sighted
within the mitigation zone. Active transmission will recommence if any
one of the following conditions is 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 10
minutes for an aircraft-deployed source, (4) the mitigation zone has
been clear from any additional sightings for a period of 30 minutes for
a vessel-deployed source, (5) the vessel or aircraft has repositioned
itself more than 400 yd. (370 m) away from the location of the last
sighting, or (6) the vessel concludes that dolphins are deliberately
closing in to ride the vessel's bow wave (and there are no other marine
mammal sightings within the mitigation zone).
Testing
Mitigation measures for high-frequency active sonar sources
currently exist only for testing activities conducted in the Inland
Waters of Puget Sound and in the Western Behm Canal, Alaska. These
activities include the use of unmanned vehicles, non-explosive
torpedoes, and similar systems. Currently, the mitigation measures for
testing activities using high frequency and non-hull-mounted mid-
frequency sources are the same as those currently in place for testing
activities with low frequency sources.
For the proposed action, the Navy is proposing that testing
activities with high frequency and non-hull-mounted mid-frequency
sources employ the proposed mitigation measures described above for
training.
For pinnipeds, the Navy proposes a 100 yd. (90 m) mitigation zone
during testing. The pinniped mitigation zone does not apply for
pierside or shore-based testing in the vicinity of pinnipeds hauled out
on man-made structures and vessels. Within Puget Sound there are
several locations where pinnipeds use Navy structures (e.g.,
submarines, security barriers) for haulouts in spite of the degree of
activity surrounding these sites. Given that animals continue to choose
these areas for their resting behavior, it would appear there are no
long-term effects or consequences to those animals as a

[[Page 31775]]

result of ongoing and routine Navy activities.

Improved Extended Echo Ranging Sonobuoys

Training
The Navy's proposed action does not include Improved Extended Echo
Ranging sonobuoy training activities.
Testing
The Navy is proposing to (1) modify the mitigation measures
currently implemented for this activity by reducing the marine mammal
mitigation zone from 1,000 yd. (920 m) to 600 yd. (550 m), (2) clarify
the conditions needed to recommence an activity after a sighting, and
(3) adopt the marine mammal mitigation zone size for floating
vegetation for ease of implementation. The recommended measures are
provided below.
Mitigation will include pre-testing aerial observation and passive
acoustic monitoring, which will begin 30 minutes before the first
source/receiver pair detonation and continue throughout the duration of
the test. The pre-testing aerial observation will include the time it
takes to deploy the sonobuoy pattern (deployment is conducted by
aircraft dropping sonobuoys in the water). Improved Extended Echo
Ranging sonobuoys will not be deployed if concentrations of floating
vegetation (kelp paddies) are observed in the mitigation zone around
the intended deployment location. Explosive detonations will cease if a
marine mammal or sea turtle is sighted within the mitigation zone.
Detonations will recommence if any one of the following conditions is
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.
Passive acoustic monitoring would be conducted with Navy assets,
such as sonobuoys, already participating in the activity. These assets
would only detect vocalizing marine mammals within the frequency bands
monitored by Navy personnel. Passive acoustic detections would provide
only limited range and bearing to detected animals, and therefore
cannot provide locations of these animals. Passive acoustic detections
would be reported to Lookouts posted in aircraft and on vessels in
order to increase vigilance of their visual surveillance.

Explosive Signal Underwater Sound Buoys Using >0.5-2.5 Pound Net
Explosive Weight

Training
The Navy is proposing to add the following recommended measures.
Mitigation will include pre-exercise aerial monitoring during
deployment within a mitigation zone of 350 yd. (320 m) around an
explosive SUS buoy. Explosive SUS buoys will not be deployed if
concentrations of floating vegetation (kelp paddies) are observed in
the mitigation zone (around the intended deployment location). SUS
deployment will cease if a marine mammal or sea turtle is sighted
within the mitigation zone. Deployment will recommence if any one of
the following conditions is 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 10
minutes.
Passive acoustic monitoring will also be conducted with Navy
assets, such as sonobuoys, already participating in the activity. These
assets would only detect vocalizing marine mammals within the frequency
bands monitored by Navy personnel. Passive acoustic detections would
not provide range or bearing to detected animals, and therefore cannot
provide locations of these animals. Passive acoustic detections would
be reported to Lookouts posted in aircraft in order to increase
vigilance of their visual surveillance.
Testing
The Navy's proposed mitigation measures for testing activities are
consistent with Navy training mitigation measures described above.

Mine Countermeasures and Neutralization Activities Using Positive
Control Firing Devices

Training
Mine countermeasure and neutralization activities in the Study Area
involve the use of diver-placed charges that typically occur close to
shore. When these activities are conducted using a positive control
firing device, the detonation is controlled by the personnel conducting
the activity and is not authorized until the area is clear at the time
of detonation.
Currently, the Navy employs the following mitigation zone
procedures during mine countermeasure and neutralization activities
using positive control firing devices:
Mitigation Zone--The exclusion zone for marine mammals
shall extend in a 700 yd. (640 m) arc radius around the detonation site
for charges >0.5-2.5 lb. NEW.
Pre-Exercise Surveys--For Demolition and Mine
Countermeasures Operations, pre-exercise surveys shall be conducted
within 30 minutes prior to the commencement of the scheduled explosive
event. The survey may be conducted from the surface, by divers, or from
the air, and personnel shall be alert to the presence of any marine
mammal. Should such an animal be present within the survey area, the
explosive event shall not be started until the animal voluntarily
leaves the area. The Navy will ensure the mitigation zone is clear of
marine mammals for a full 30 minutes prior to initiating the explosive
event. Personnel will record any marine mammal observations during the
exercise as well as measures taken if species are detected within the
exclusion zone.
Post-Exercise Surveys--Surveys within the same radius
shall also be conducted within 30 minutes after the completion of the
explosive event.
For activities involving positive control diver-placed charges, the
Navy is proposing to (1) modify the currently implemented mitigation
measures for this activity involving >0.5-2.5 lb. NEW detonation by
changing the mitigation zone from 700 yd. (640 m) to 400 yd. (366 m),
(2) clarify the conditions needed to recommence an activity after a
sighting, and (3) add a requirement to observe for floating vegetation.
The recommended measures for activities involving positive control
diver-placed activities are provided below.
The Navy is proposing to use the 400 yd. (366 m) mitigation zones
for marine mammals described above during activities involving positive
control diver-placed charges involving >0.5-2.5 lb. NEW. Visual
observation will be conducted by two small boats, each with a minimum
of one surveyor.
Explosive detonations will cease if a marine mammal is sighted in
the water portion of the mitigation zone (i.e., not on shore).
Detonations will recommence if any one of the following conditions is
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.
Testing
The Navy's proposed action does not include mine countermeasure and
neutralization testing activities.

[[Page 31776]]

Gunnery Exercises--Small and Medium-Caliber Using a Surface Target

Training
The Navy is proposing to (1) continue implementing the current
mitigation measures for this activity, (2) clarify the conditions
needed to recommence an activity after a sighting, and (3) add a
requirement to visually observe for kelp paddies.
Mitigation will include visual observation from a vessel or
aircraft immediately before and during the exercise within a mitigation
zone of 200 yd. (180 m) around the intended impact location. Vessels
will observe the mitigation zone from the firing position. When
aircraft are firing, the aircrew will maintain visual watch of the
mitigation zone during the activity. The exercise will not commence if
concentrations of floating vegetation (kelp paddies) are observed in
the mitigation zone. Firing will cease if a marine mammal is sighted
within the mitigation zone. Firing will recommence if any one of the
following conditions is 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 10 minutes
for a firing aircraft, (4) the mitigation zone has been clear from any
additional sightings for a period of 30 minutes for a firing ship, or
(5) the intended target location has been repositioned more than 400
yd. (370 m) away from the location of the last sighting.
Testing
The Navy's proposed action does not include gunnery testing
activities.

Gunnery Exercises--Large-Caliber Explosive Rounds Using a Surface
Target

Training
There are currently no existing mitigation measures unique to
large-caliber explosive gunnery exercises in the Study Area. The Navy
is proposing to adopt mitigation measures in place at other Navy
training ranges outside of the Study Area.
For all explosive and non-explosive large-caliber gunnery exercises
conducted from a ship, mitigation will include visual observation
immediately before and during the exercise within a mitigation zone of
70 yd. (46 m) within 30 degrees on either side of the gun target line
on the firing side. The exercise will not commence if concentrations of
floating vegetation (kelp paddies) are observed in the mitigation zone.
Firing will cease if a marine mammal is sighted within the mitigation
zone. Firing will recommence if any one of the following conditions is
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 vessel has
repositioned itself more than 140 yd. (128 m) away from the location of
the last sighting.
Testing
The Navy is proposing to (1) implement new mitigation zone measures
for this activity, (2) describe conditions needed to recommence an
activity after a sighting, and (3) implement a requirement to visually
observe for kelp paddies. The recommended measures are provided below.
Mitigation will include visual observation from a ship immediately
before and during the exercise within a mitigation zone of 600 yd. (550
m) around the intended impact location. Ships will observe the
mitigation zone from the firing position. The exercise will not
commence if concentrations of floating vegetation (kelp paddies) are
observed in the mitigation zone. Firing will cease if a marine mammal
is sighted within the mitigation zone. Firing will recommence if any
one of the following conditions is 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.

Missile Exercises up to 250 Pound Net Explosive Weight Using a Surface
Target

Training
Currently, the Navy employs a mitigation zone of 1,800 yd. (1.6 km)
for all missile exercises. Because the Navy is not proposing to use
missiles with less than a 251 lb. NEW warhead in the Study Area,
separate mitigation procedures for this exercise have not been
developed. Should the need arise to conduct training using missiles in
this category, the Navy proposes that mitigation procedures be followed
as described below for the larger category of missiles (Missile
Exercises 251-500 Pound Net Explosive Weight [Surface Target]).
Testing
The Navy's proposed action does not include missile testing
activities.

Missile Exercises 251-500 Pound Net Explosive Weight (Surface Target)

Training
Current mitigation measures apply to all missile exercises,
regardless of the warhead size. The Navy proposes to add a mitigation
zone that applies only to missiles with a NEW of 251-500 lb. The
recommended measures are provided below.
When aircraft are involved in the missile firing, mitigation will
include visual observation by the aircrew prior to commencement of the
activity within a mitigation zone of 2,000 yd. (1.8 km) around the
intended impact location. The exercise will not commence if
concentrations of floating vegetation (kelp paddies) are observed in
the mitigation zone. Firing will cease if a marine mammal is sighted
within the mitigation zone. Firing will recommence if any one of the
following conditions is 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 10
minutes or 30 minutes (depending on aircraft type).
Testing
The Navy's proposed action does not include missile testing
activities.

Bombing Exercises

Training
Currently, the Navy employs the following mitigation zone
procedures during bombing exercises:
Ordnance shall not be targeted to impact within 1,000 yd.
(920 m) of known or observed floating kelp or marine mammals.
A 1,000 yd. (920 m) radius mitigation zone shall be
established around the intended target.
The exercise will be conducted only if marine mammals are
not visible within the mitigation zone.
The Navy is proposing to (1) maintain the existing mitigation zone
to be used for non-explosive bombing activities, (2) revise the
mitigation zone procedures to account for predicted ranges to impacts
to marine species when high explosive bombs are used, (3) clarify the
conditions needed to recommence an activity after a sighting, and (4)
add a requirement to visually observe for kelp paddies.
Mitigation will include visual observation from the aircraft

[[Page 31777]]

immediately before the exercise and during target approach within a
mitigation zone of 2,500 yd. (2.3 km) around the intended impact
location for explosive bombs and 1,000 yd. (920 m) for non-explosive
bombs. The exercise will not commence if concentrations of floating
vegetation (kelp paddies) are observed in the mitigation zone. Bombing
will cease if a marine mammal is sighted within the mitigation zone.
Bombing will recommence if any one of the following conditions is 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 10 minutes.
Testing
The Navy's proposed action does not include bomb testing
activities.

Torpedo (Explosive) Testing

Training
The Navy does not include training with explosive torpedoes in the
proposed action.
Testing
The Navy is proposing to (1) establish mitigation measures for this
activity that include a mitigation zone of 2,100 yd. (1.9 km), (2)
establish the conditions needed to recommence an activity after a
sighting, and (3) establish a requirement to visually observe for kelp
paddies. The recommended measures are provided below.
Mitigation will include visual observation by aircraft (with the
exception of platforms operating at high altitudes) immediately before,
during, and after the event within a mitigation zone of 2,100 yd. (1.9
km) around the intended impact location. The event will not commence if
concentrations of floating vegetation (kelp paddies) are observed in
the mitigation zone. Firing will cease if a marine mammal or sea turtle
is sighted within the mitigation zone. Firing will recommence if any
one of the following conditions is 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 10 minutes or 30 minutes (depending on aircraft type).
In addition to visual observation, passive acoustic monitoring will
be conducted with Navy assets, such as passive ships sonar systems or
sonobuoys, already participating in the activity. Passive acoustic
observation would be accomplished through the use of remote acoustic
sensors or expendable sonobuoys, or via passive acoustic sensors on
submarines when they participate in the proposed action. These assets
would only detect vocalizing marine mammals within the frequency bands
monitored by Navy personnel. Passive acoustic detections would not
provide range or bearing to detected animals, and therefore cannot
provide locations of these animals. Passive acoustic detections would
be reported to the Lookout posted in the aircraft in order to increase
vigilance of the visual surveillance; and to the person in control of
the activity for their consideration in determining when the mitigation
zone is determined free of visible marine mammals.

Weapons Firing Noise During Gunnery Exercises--Large-Caliber

Training
The Navy and U.S. Coast Guard are proposing to adopt measures
currently used during Navy gunnery exercises in other ranges outside of
the Study Area. For all explosive and non-explosive large-caliber
gunnery exercises conducted from a ship, mitigation will include visual
observation immediately before and during the exercise within a
mitigation zone of 70 yd. (46 m) within 30 degrees on either side of
the gun target line on the firing side. The exercise will not commence
if concentrations of floating vegetation (kelp paddies) are observed in
the mitigation zone. Firing will cease if a marine mammal is sighted
within the mitigation zone. Firing will recommence if any one of the
following conditions is 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 vessel has repositioned itself more than 140 yd.
(128 m) away from the location of the last sighting.
Testing
The Navy's proposed action does not include gun testing activities.

Vessels

Training
The Navy's current measures to mitigate potential impacts to marine
mammals from vessel and in-water device strikes during training
activities are provided below:
Naval vessels shall maneuver to keep at least 500 yd. (460
m) away from any observed whale in the vessel's path and avoid
approaching whales head-on. These requirements do not apply if a
vessel's safety is threatened, such as when change of course will
create an imminent and serious threat to a person, vessel, or aircraft,
and to the extent vessels are restricted in their ability to maneuver.
Restricted maneuverability includes, but is not limited to, situations
when vessels are engaged in dredging, submerged activities, launching
and recovering aircraft or landing craft, minesweeping activities,
replenishment while underway and towing activities that severely
restrict a vessel's ability to deviate course.
Vessels will take reasonable steps to alert other vessels
in the vicinity of the whale. Given rapid swimming speeds and
maneuverability of many dolphin species, naval vessels would maintain
normal course and speed on sighting dolphins unless some condition
indicated a need for the vessel to maneuver.
The Navy is proposing to continue to use the 500 yd. (460 m)
mitigation zone currently established for whales, and to implement a
200 yd. (180 m) mitigation zone for all other marine mammals. Vessels
will avoid approaching marine mammals head on and will maneuver to
maintain a mitigation zone of 500 yd. (460 m) around observed whales
and 200 yd. (180 m) around all other marine mammals (except bow-riding
dolphins), providing it is safe to do so.
Testing
The Navy's current measures to mitigate potential impacts to marine
mammals from vessel and in-water device strikes during testing
activities are provided below:
Range activities shall be conducted in such a way as to
ensure marine mammals are not harassed or harmed by human-caused
events.
Visual surveillance shall be accomplished just prior to
all in-water exercises. This surveillance shall ensure that no marine
mammals are visible within the boundaries of the area within which the
test unit is expected to be operating. Surveillance shall include, as a
minimum, monitoring from all participating surface craft and, where
available, adjacent shore sites.
The Navy shall postpone activities until cetaceans
(whales, dolphins, and porpoises) leave the activity area. When
cetaceans have been sighted in an area, all range participants increase
vigilance and take reasonable and practicable actions to avoid
collisions and activities that may result in close interaction of naval
assets and marine mammals. Actions may include changing speed or

[[Page 31778]]

direction and are dictated by environmental and other conditions (e.g.,
safety, weather).
Range craft shall not approach within 100 yd. (90 m) of
marine mammals and shall be followed to the extent practicable
considering human and vessel safety priorities. All Navy vessels and
aircraft, including helicopters, are expected to comply with this
directive. This includes marine mammals ``hauled-out'' on islands,
rocks, and other areas such as buoys.
The Navy is proposing to incorporate the training mitigation
measures described above during testing activities involving surface
ships, and for all other testing activities to continue using the
mitigation measures currently implemented, revised to exclude pinnipeds
during test body retrieval and to include the exception for bow-riding
dolphins as described above under Training. During test body retrieval,
the activity cannot be relocated away from marine mammals active in the
area, or significantly delayed without risking loss of the test body,
so the activity must proceed even if pinnipeds are present in the
immediate vicinity. However, the retrieval vessel is a range craft and
risks to marine mammals are very low.

Towed In-Water Devices

Training
The Navy is proposing to adopt measures currently used in other
ranges outside of the Study Area during activities involving towed in-
water devices. The Navy will ensure that towed in-water devices being
towed from manned platforms avoid coming within a mitigation zone of
250 yd. (230 m) around any observed marine mammal, providing it is safe
to do so.
Testing
The Navy's proposed mitigation measures for testing activities from
manned platforms are consistent with Navy training mitigation measures
described above. During testing in which in-water devices are towed by
unmanned platforms, a manned escort vessel will be included and one
Lookout will be employed.

Non-Explosive Gunnery Exercises--Small, Medium, and Large-Caliber Using
a Surface Target

Training
Currently, the Navy employs the same mitigation measures for non-
explosive gunnery exercises as described above for explosive Gunnery
Exercises--Small-, Medium-, and Large-Caliber Using a Surface Target.
The Navy is proposing to (1) continue using the mitigation measures
currently implemented for this activity, and (2) clarify the conditions
needed to recommence an activity after a sighting. The recommended
measures are provided below.
Mitigation will include visual observation from a vessel or
aircraft immediately before and during the exercise within a mitigation
zone of 200 yd. (180 m) around the intended impact location. The
exercise will not commence if concentrations of floating vegetation
(kelp paddies) are observed in the mitigation zone. Firing will cease
if a marine mammal is sighted within the mitigation zone. Firing will
recommence if any one of the following conditions is 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 10 minutes for a firing aircraft, (4) the
mitigation zone has been clear from any additional sightings for a
period of 30 minutes for a firing ship, or (5) the intended target
location has been repositioned more than 400 yd. (370 m) away from the
location of the last sighting.
Testing
The Navy's proposed action does not include gunnery testing
activities.

Non-Explosive Bombing Exercises

Training
The Navy is proposing to continue using the mitigation measures
currently implemented for this activity. The recommended measure
includes clarification of a post-sighting activity recommencement
criterion.
Mitigation will include visual observation from the aircraft
immediately before the exercise and during target approach within a
mitigation zone of 1,000 yd. (920 m) around the intended impact
location. The exercise will not commence if concentrations of floating
vegetation (kelp paddies) are observed in the mitigation zone. Bombing
will cease if a marine mammal is sighted within the mitigation zone.
Bombing will recommence if any one of the following conditions is 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 10 minutes.
Testing
The Navy's proposed action does not include bomb testing
activities.

Consideration of Time/Area Limitations

Already incorporated into the Navy's and NMFS' analysis of affects
to marine mammals, has been consideration of emergent science regarding
locations where cetaceans are known to engage in specific activities
(e.g., feeding, breeding/calving, or migration) at certain times of the
year that are important to individual animals as well as populations of
marine mammals (see discussion in Van Parijs, 2015). As explained in
that paper, each such location has been designated a Biologically
Important Area (BIA). It is important to note that the BIAs were not
meant to define exclusionary zones, nor were they meant to be locations
that serve as sanctuaries from human activity, or areas analogous to
marine protected areas (see Ferguson et al. (2015a) regarding the
envisioned purpose for the BIA designations). The delineation of BIAs
does not have direct or immediate regulatory consequences. The
intention was that the BIAs would serve as resource management tools
and their boundaries be dynamic and considered along with any new
information as well as, ``existing density estimates, range-wide
distribution data, information on population trends and life history
parameters, known threats to the population, and other relevant
information'' (Van Parijs, 2015).
The Navy and NMFS have supported and will continue to support the
Cetacean and Sound Mapping project, including providing representation
on the Cetacean Density and Distribution Mapping Working Group (CetMap)
developing the BIAs. The final products, including U.S. West Coast
BIAs, from this mapping effort were completed and published in March
2015 (Aquatic Mammals, 2015; Calambokidis et al., 2015; Ferguson et
al., 2015a, 2015b; Van Parijs, 2015). 131 BIAs for 24 marine mammal
species, stocks, or populations in seven regions within U.S. waters
were identified (Ferguson et al., 2015a). BIAs in the West Coast of the
continental U.S. with the potential to overlap portions of the Study
Area include the following feeding and migration areas: Northern Puget
Sound Feeding Area for gray whales; Northbound Migration Phase A for
gray whales; Northbound Migration Phase B for gray whales; Potential
Presence Migration Area for gray whales; Northern Washington Feeding
Area for humpback whales; Stonewall and Heceta Bank Feeding Area for

[[Page 31779]]

humpback whales; Cape Blanco and Orford Reef Feeding Area for gray
whale; and Point St. George Feeding Area for gray whales (Calambokidis
et al., 2015).
NMFS Office of Protected Resources routinely considers available
information about marine mammal habitat use to inform discussions with
applicants regarding potential spatio-temporal limitations on their
activities that might help effect the least practicable adverse impact
on species or stocks and their habitat. BIAs are useful tools for
planning and impact assessments and are being provided to the public
via this Web site: www.cetsound.noaa.gov. 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, nor does it have direct or
immediate regulatory consequences.
During the April 2014 annual adaptive management meeting in
Washington, DC, NMFS and the Navy discussed the BIAs that might overlap
with portions of the NWTT Study Area, what Navy activities take place
in these areas (in the context of what their effects on marine mammals
might be or whether additional mitigation is necessary), and what
measures could be implemented to reduce impacts in these areas (in the
context of their potential to reduce marine mammal impacts and their
practicability). Upon request by NMFS the Navy preparing a draft
assessment of these BIAs, including the degree of spatial overlap as
well as an assessment of potential impacts or lack of impacts for each
BIA. The Navy preliminarily determined that the degree of overlap
between Navy activities within the Study Area and regional BIAs is
relatively small (10 percent) geographically. Further, a review of the
BIAs for humpback whales and gray whales against areas where most
acoustic activities are conducted in the Study Area (especially those
that involve ASW hull-mounted sonar, sonobuoys, and use of explosive
munitions) identified that there is no spatial overlap. The Navy
preliminarily concluded that any potential impacts from training and
testing activities on a given area are infrequent, spatially and
temporally variable, and biologically insignificant since the
activities are unlikely to significantly affect the marine mammal
activities for which the BIAs were designated. The Navy also concluded
that additional mitigations other than those already described in the
January 2014 NWTT DEIS/OEIS and LOA application would not be further
protective nor offer addition protection to marine mammals beyond what
is already proposed. NMFS is currently reviewing the Navy's draft
assessment, the outcome of which will be discussed in the final rule.
As we learn more about marine mammal density, distribution, and
habitat use (and the BIAs are updated), NMFS and the Navy will continue
to reevaluate appropriate time-area measures through the Adaptive
Management process outlined in these regulations.

Stranding Response Plan

NMFS and the Navy developed a Stranding Response Plan for the NWTRC
in 2010 and the NUWC Keyport Range Complex in 2011 as part of the
incidental take authorization process for those complexes. The
Stranding Response Plan is specifically intended to outline the
applicable requirements in the event that a marine mammal stranding is
reported in the complexes during a major training exercise. NMFS
considers all plausible causes within the course of a stranding
investigation and this plan in no way presumes 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 plan is designed to address mitigation, monitoring, and compliance.
The Navy is currently working with NMFS to refine this plan for the
NWTT Study Area. The current Stranding Response Plans for the NWTRC and
NUWC Keyport Range Complex are available for review here: http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm.

Mitigation Conclusions

NMFS has carefully evaluated the Navy's proposed mitigation
measures--many of which were developed with NMFS' input during the
first phase of Navy Training and Testing authorizations--and considered
a 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 mitigation
measures is expected to reduce the likelihood and/or magnitude of
adverse impacts to marine mammal species and stocks and their habitat;
the proven or likely efficacy of the measures; and the practicability
of the suite of measures for applicant implementation, including
consideration of personnel safety, practicality of implementation, and
impact on the effectiveness of the military readiness activity.
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 accomplishing one or more of the
general goals listed below:
a. Avoid or minimize injury or death of marine mammals wherever
possible (goals b, c, and d may contribute to this goal).
b. Reduce the number 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. Reduce 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. Reduce the intensity of exposures (either total number or number
at biologically important time or location) to received levels of MFAS/
HFAS, underwater detonations, or other activities expected to result in
the take of marine mammals (this goal may contribute to a, above, or to
reducing the severity of harassment takes only).
e. Avoid or minimize 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--increase 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, NMFS has determined preliminarily
that the Navy's proposed mitigation measures (especially when the
adaptive management component is taken into

[[Page 31780]]

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.
The proposed rule comment period provides 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 effect
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.

Integrated Comprehensive Monitoring Program (ICMP)

The Navy's 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 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 contribute towards
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 (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.
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 surveys) 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. Details of the ICMP are available online (http://www.navymarinespeciesmonitoring.us/).

Strategic Planning Process for Marine Species Monitoring

The Navy also developed the Strategic Planning Process for Marine
Species Monitoring, which establishes the guidelines and processes
necessary to develop, evaluate, and fund individual projects based on
objective scientific study questions. The process uses an underlying
framework designed around top-level goals, a conceptual framework
incorporating a progression of knowledge, and in consultation with a
Scientific Advisory Group and other regional experts. The Strategic
Planning Process for Marine Species Monitoring 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. This 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. The Strategic Planning Process for Marine
Species Monitoring is also available online (http://www.navymarinespeciesmonitoring.us/).

Past Monitoring in the NWTT Study Area

NMFS has received multiple years' worth of annual exercise and
monitoring reports addressing active sonar use and explosive
detonations within the NWTT and other Navy range complexes. The data
and information contained in these reports have been considered in
developing mitigation and

[[Page 31781]]

monitoring measures for the proposed training and testing activities
within the NWTT Study Area. The Navy's annual exercise and monitoring
reports may be viewed at: http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm 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.
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.
This following section includes a summary of Navy-funded compliance
monitoring in the NWTRC since 2010 and in the NUWC Keyport Range
Complex since 2011. Additional Navy-funded monitoring outside of and in
addition to the Navy's commitments to NMFS is provided later in the
section. The monitoring years are shown in Table 12.

Table 12--Navy Monitoring Years in the Study Area
----------------------------------------------------------------------------------------------------------------
Navy monitoring years in the study
area range complex Year 1 Year 2 Year 3
----------------------------------------------------------------------------------------------------------------
Northwest Training Range Complex..... 12 November 2010-01 May 02 May 2011-01 May 2012 02 May 2012-01 May
2011. 2013.
Keyport Range Complex................ 12 April 2011-08 09 November 2011-08 09 November 2012-08
November 2011. November 2012. November 2013.
----------------------------------------------------------------------------------------------------------------

Northwest Training Range Complex

Passive Acoustic Monitoring
As part of previous monitoring within the Pacific Northwest, the
Navy funded deployment of two passive acoustic devices along the
central coast of Washington State from 2011 to 2013. Results from this
effort are summarized in the Navy's annual NWTRC monitoring reports for
2011, 2012, and 2013 (U.S. Department of the Navy, 2011;
[Scaron]irovi[cacute] et al., 2012a and 2012b in U.S. Department of the
Navy, 2012a; Kerosky et al., 2013 in U.S. Department of the Navy,
2013). Total passive acoustic data recorded over the 3 years totals
over 17,417 hours and includes signals from four baleen whale species
(blue whale, fin whale, gray whale, and humpback whale) and seven
odontocetes (Risso's dolphin, Pacific white-sided dolphin, killer
whale, sperm whale, Stejneger's beaked whale, Baird's beaked whale, and
Cuvier's beaked whale) (Kerosky et al. 2013 in U.S. Department of the
Navy, 2013). Kerosky et al. (2013) found that seasonal patterns of all
four baleen whale species were similar within the monitoring sites in
NWTRC, with most calls detected between winter and early spring. Of the
odontocetes recorded, sperm whales were generally detected most
consistently while other non-beaked odontocetes occurred more
sporadically. Stejneger's beaked whales were the most consistently
recorded beaked whale, with all their detections occurring between
December and June. Previous research-funded results from these same
locations from 2004 to 2010 is available in Oleson et al. (2009) and
Oleson and Hildebrand (2012).
Satellite Tagging
The Navy purchased 10 satellite tracking tags in Year 1, suitable
for deployment by a suite of marine species within the offshore waters
of the NWTRC. The tags used were the Andrews-style LIMPET (Low Impact
Minimally Percutaneous External Transmitter), in either the location-
only Spot5 configuration or the location/dive data Mk10-A configuration
(Wildlife Computers, Redmond, Washington) (Schorr et al., 2012). Tags
were programmed to species-specific, transmission schedule-based
surfacing behavior and transmission data from previous deployments.
Tags transmit animal movement data via the Argos satellite system. The
commercial Argos system consists of data acquisition and relay
equipment attached to NOAA low-orbiting weather satellites and ground-
based receivers and data processing systems.
The Navy purchased these satellite tracking tags as part of the
NWTRC monitoring from 2010 to 2013. The tags were deployed
opportunistically during field efforts associated with a 3-year
collaborative field project addressing marine mammal distribution and
habitat use off Oregon and Washington (Schorr et al., 2012). The
species of interest were endangered cetaceans such as blue whales, fin
whales, humpback whales, and sperm whales, but also included high-
priority cetaceans such as beaked whales, in the event they were
encountered in favorable tagging conditions. Other species of interest
for tagging included seasonal resident gray whales and transient or
offshore killer whales.
Annual results from this effort are summarized in the Navy's NWTRC
Monitoring Reports for 2011, 2012, and 2013 (U.S. Department of the
Navy, 2011a, 2012a, and 2013d) and collectively in Schorr et al.
(2012). During this reporting period (2010-2013), a collective total of
21 tags were deployed on four different species off the Washington
coast (3 gray whales, 5 humpback whales, 11 fin whales, and 2 offshore
killer whales). A total of approximately 348 days of animal movement
data was obtained (Schorr et al., 2013; U.S. Department of the Navy,
2013d). Transmissions confirmed that gray whales were not migrating;
rather, they stayed very close to shore and in a very localized area
consistent with feeding. Movement data for the tagged

[[Page 31782]]

humpback whales suggest individuals spent time both on and off the
shelf edge, including some of the underwater canyons off northern
Washington. Movements obtained from tagged fin whales suggest these
whales are most commonly using waters associated with the outer shelf
edge. Overall, 75 percent of the fin whale locations received were
within the NWTRC. Three fin whales with transmission durations greater
than 21 days remained in the NWTRC for the entire duration of tag
transmission. According to Schorr et al. (2013), localized movements
for periods of this duration suggest that at least some fin whales are
not simply migrating through the area, but are utilizing habitat within
the NWTRC for extended periods of time, even during seasons generally
associated with migration and use of lower latitude breeding areas for
other baleen whales. While in the NWTRC, tagged killer whales primarily
spent their time on the continental shelf, or well offshore of the
shelf edge.
In 2012, the Navy funded a multi-year satellite tracking study of
Pacific Coast Feeding Group gray whales (U.S. Department of the Navy,
2013d). Tags were attached to 11 gray whales near Crescent City,
California, in fall 2012 (Mate, 2013). Good track histories were
received from nine of the 11 tags which confirmed an exclusive near
shore (< 15 km) distribution and movement along the California, Oregon,
and Washington coast. Additional tag deployments on gray whales have
occurred since the Mate (2013) report. These will be described in the
NWTRC Year 4 Annual Monitoring Report in 2014.
Satellite tagging efforts are also funded for 2014-2018 along the
U.S. west coast and include fin and blue whales. Longer term tags (up
to 1 year) will allow for an assessment of animal occurrence, movement
patterns, and residence time at areas within and outside of Navy at-sea
ranges, including the NWTRC.

Explosive Ordnance/Underwater Detonation Monitoring

The Navy has conducted two annual underwater detonation training
events in the NWTRC at the Floral Point site in Hood Canal. In 2012,
the event was monitored by marine mammal and seabird observers, and
acoustic measurements were also recorded. The observers were positioned
aboard small Navy craft that followed a closely spaced transect pattern
in nearshore waters. In 2013, a similar monitoring effort occurred, but
two beach observers were added to the monitoring team in order to
provide a training opportunity. The beach observers are not required
under the permits. The entire area to be monitored can be seen via the
small craft vessels and as a result of the tightly spaced transect
observation pattern. Pre-event and post-event surveys were also
conducted. Harbor seals were the only marine mammal species seen either
before or after the training event, and no marine mammals were in the
exclusion zone during the detonations.

Keyport Range Complex

Annual monitoring surveys were undertaken in 2011, 2012, and 2013
in the DBRC portion of the Keyport Range Complex. These surveys
included both visual and passive acoustic monitoring during concurrent
mid-frequency active sonar and high-frequency active sonar tests. In
addition to Navy Lookouts, Navy marine mammal observers were positioned
aboard range vessels and at a high elevation observation point on land
to monitor the events. A pre-event and post-event survey was also
conducted. Species seen included harbor seals, California sea lions,
and harbor porpoise. In total over all years, there were 262 sightings
representing 420 individuals seen during the visual surveys, which may
include repeat sightings of the same individuals. No marine mammals
were detected using the bottom-moored passive acoustic monitoring array
in any year. Discussion and results from these efforts are summarized
in the Navy's Keyport Range Complex Annual Monitoring Reports for 2011,
2012, and 2013 (U.S. Department of the Navy, 2012c, 2012d, and 2013e).

Other Regional Navy-Funded Monitoring Efforts

Additional marine mammal studies are being funded or conducted by
the Navy outside of and in addition to the Navy's commitments to NMFS
for the NWTRC and the NUWC Keyport Range Complex. A variety of field
survey methodologies are being utilized in order to better determine
marine mammal presence, seasonality, abundance, distribution, habitat
use, and density in these areas. The following studies either have been
conducted or are underway during the 2010-2014 period:
Naval Base Pinniped Haulout Surveys (2010-2014):
Biologists located at NAVBASE Kitsap, Bangor, Bremerton, the Manchester
Fuel Depot, and Naval Station Everett have been conducting year-round
counts of sea lions hauled out on site-specific structures such as the
floating security fences, submarines, or other opportunistic haulouts
such as the large floating dock near Manchester. These counts are
typically conducted weekly and involve identifying the sea lions to
species and documenting branded animals. This information has shown
seasonal use of the haulouts at each site, as well as trends in the
number of animals by species using the haulouts at each site. In the
case of Bangor, there are no haulout areas used by adult harbor seals,
despite the adults being seen daily in the water, year-round. The only
exception to this would be during pupping season when one wave screen
(floating dock) is used temporarily by adult females to give birth. In
late fall 2013, there were sightings of individual harbor seal pups
using opportunistic manmade structures as temporary haulouts. These
sightings include one harbor seal pup using a partially submerged
ladder rung as a haulout and place to nurse; another pup resting on a
floating oil boom; a third pup resting on a large piece of chain
hanging in the water; a fourth pup managing to get aboard a submarine
and haul out next to the California sea lions; and a fifth, older
juvenile resting on the outer pontoon of the floating security fence.
Harbor seals have not been seen hauled out at Bremerton or at the
floating dock near Manchester. Harbor seals do haul out on the log
rafts near Naval Station Everett.
Marine Mammal Surveys in Hood Canal and Dabob Bay (2011-
2012): The Navy conducted an opportunistic marine mammal vessel-based
line transect density survey in Hood Canal and Dabob Bay during
September and October 2011 and again in October 2012. In Hood Canal,
the surveys followed a double saw-tooth pattern to achieve uniform
coverage of the entire NAVBASE Kitsap, Bangor waterfront. Transects
generally covered the area from Hazel Point on the south end of the
Toandos Peninsula to Thorndyke Bay. Surveys in the adjacent Dabob Bay
followed a slightly different pattern and generally followed more
closely to the shoreline while completing a circular route through the
Bay. These surveys had a dual purpose of collecting marine mammal and
marbled murrelet (bird species) data, and near-shore surveys tended to
yield more marbled murrelet sightings. During surveys, the survey
vessels traveled at a speed of approximately five knots when transiting
along the transect lines. Two observers recorded sightings of marine
mammals both in the water and hauled out. Marine mammal sightings data
included species identification, Global Positioning System animal
locations relative to vessel position, and detailed behavioral notes.
Data from the line

[[Page 31783]]

transect surveys can be used to improve estimates of marine mammal
density in Hood Canal and Dabob Bay.
Aerial Surveys of Pinniped Haulout Sites in Pacific
Northwest Inland Waters (2013-2014): Navy-funded aerial surveys of
pinniped haulout sites in the inland waters of Washington State were
initiated in March 2013 (Jeffries, 2013b) and continued until March
2014 (1-year study design). The objectives of this effort were to
provide estimates of seasonal abundance, identify seasonal distribution
patterns, and collect data to determine seal and sea lion densities.
Aerial surveys being conducted under this effort represent the first
pinniped assessments to be done in the region over all four seasons,
and will therefore provide much-needed information about seasonal
variation of harbor seal, northern elephant seal, California sea lion,
and Steller sea lion distribution and abundance in the inland waters of
Washington. In addition, this effort will update the Atlas of Seal and
Seal Lion Haulout Sites in Washington (inland waters region) (Jeffries
et al., 2000). Finally, in a collaborative effort, the NMFS Northwest
Region provided additional funding to support summer-only aerial
surveys of the U.S. waters of the Strait of Juan de Fuca (Cape Flattery
to Port Angeles), as well as the San Juan Islands. This collaborative
approach between the Navy and NMFS will allow NMFS to update the SAR
for the Pacific harbor seal (Washington Inland Waters stock). The
current SAR is derived from population estimates from 1999, and
abundance information from current surveys will provide NMFS with
required data to revise this outdated stock assessment.
Aerial Surveys of Marine Mammals in Pacific Northwest
Inland Waters (2013-2014): Navy-funded aerial line-transect density
surveys in the inland waters of Washington State were initiated in
August 2013 (Smultea and Bacon, 2013). Surveys are planned to continue
quarterly (every season) through 2014. These surveys were designed in
cooperation with NMFS in order to estimate density and abundance of
species with sufficient sightings, document distribution and habitat
use, and describe behaviors seen. Smultea and Bacon (2013) reported a
total of 779 sightings composed of an estimated 1,716 individual marine
mammals representing four species: Harbor seal, harbor porpoise,
California sea lion, and Risso's dolphins. Eighty-seven percent of
sightings were of harbor seals, while harbor porpoise were the second-
most frequent sighting (9 percent), followed by California sea lions; a
pair of Risso's dolphins were seen twice.
Tagging and Behavioral Monitoring of Sea Lions in the
Pacific Northwest in Proximity to Navy Facilities (2013-2015): In an
Interagency Agreement between the Navy and the NMFS Alaska Fisheries
Science Center, the Navy has funded a sea lion satellite tagging study
beginning in 2013 through 2015. Tagging is anticipated to occur in
early 2014 with monitoring and data analysis extending into 2015. There
are significant scientific data gaps in identifying the location of
local foraging areas and percentage of time hauled out for pinniped
species near Puget Sound Navy facilities. Data collected from this
project will directly tie into Navy's future Phase III marine mammal
density modeling for training and testing activities at-sea, and within
Puget Sound. In particular, integration of improved haulout percentages
will lower over-predictive modeled takes which currently, due to lack
of regional data, assume all pinniped species are always in-water for
purposes of model assessment of takes. Numbers of animals observed
hauled out can be corrected into a population estimate by applying an
estimate of the proportion of satellite-tagged-animals that are hauled
out at the time of the census. Satellite-linked dive recorders can be
used to assess location of foraging activity and describe the diving
behavior, as well as record when the animal is hauled out.

Proposed Monitoring for the NWTT Study Area

Based on NMFS-Navy meetings in June and October 2011, future Navy
compliance monitoring, including pending NWTT monitoring, will address
ICMP top-level goals through a series of regional and ocean basin study
questions with a prioritization and funding focus on species of
interest as identified for each range complex. The ICMP will also
address relative investments to different range complexes based on
goals across all range complexes, and monitoring will leverage multiple
techniques for data acquisition and analysis whenever possible.
Within the NWTT area, the Navy's initial recommendation for species
of interest includes blue whale, fin whale, humpback whale, Southern
Resident killer whale (offshore portion of their annual movements), and
beaked whales. Navy monitoring for NWTT under this LOA authorization
and concurrently in other areas of the Pacific Ocean will therefore be
structured to address region-specific species-specific study questions
that will be outlined in the final NWTT Monitoring Project Table in
consultation with NMFS.
As an early start to NWTT monitoring, in July 2014 the Navy
provided funding ($209,000) to NMFS' Northwest Fisheries Science Center
to jointly participate in a new NWTT-specific study: Modeling the
distribution of southern resident killer whales in the Pacific
Northwest. The goal of this new study is to provide a more scientific
understanding of endangered southern resident killer whale winter
distribution off the Pacific Northwest coast. While the end project
will work to develop a Bayesian space-state model for predicting the
offshore winter occurrence, the project will actually consist of
analysis of existing NMFS data (passive acoustic detections, satellite
tag tracks) as well as new data collection from fall 2014 through
spring 2015. Details of the study can be found at: http://www.navymarinespeciesmonitoring.us/regions/pacific/current-projects/.
The eight main tasks the study supports include:
Identification and classification of marine mammal
detections from acoustic recorders.
Acquisition and field deployment of satellite-linked
transmitters (n=4) to track and determine southern resident killer
whales movements.
Deployment of autonomous underwater acoustic recorders in
and adjacent to the coastal and shelf/slope waters of Washington State.
Navy funding will allow 10 additional recorders to be purchased and
deployed along with four NMFS recorders for a total of 14 deployed
recorders.
Estimation of the probability of Southern Resident killer
whale detection on acoustic recorders.
Development of the state-space occurrence models.
Development of predicative maps of the seasonal annual
occurrence of southern resident killer whales.
Development a cost efficient strategy for the deployment
of acoustic recorders in and adjacent to Pacific Northwest Navy ranges.
Reporting.

Ongoing Navy Research

The U.S. Navy is one of the world's leading organizations in
assessing the effects of human activities the marine environment,
including marine mammals. From 2004 through 2013, the Navy has funded
over $240M specifically for marine mammal research. Navy scientists
work cooperatively with other government researchers and scientists,
universities, industry, and non-governmental conservation organizations
in collecting, evaluating, and modeling information

[[Page 31784]]

on marine resources. They also develop approaches to ensure that these
resources are minimally impacted by existing and future Navy
operations. It is imperative that the Navy's Research and Development
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. Historically, R&D
programs are funded and developed by the Navy's Chief of Naval
Operations Energy and Environmental Readiness and Office of Naval
Research (ONR), Code 322 Marine Mammals and Biological Oceanography
Program. Primary focus of these programs since the 1990s is on
understanding the effects of sound on marine mammals, including
physiological, behavioral and ecological effects.
ONR's current Marine Mammals and Biology Program thrusts include,
but are not limited to: (1) Monitoring and detection research; (2)
integrated ecosystem research including sensor and tag development; (3)
effects of sound on marine life (such as hearing, behavioral response
studies, physiology [diving and stress], and PCAD); and (4) 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 (http://www.lmr.navy.mil/). The
goal of the LMR Research and Development Program is to identify and
fill knowledge gaps and to demonstrate, validate, and integrate new
processes and technologies to minimize potential effects to marine
mammals and other marine resources. Key elements of the LMR program
include:
Providing science-based information to support Navy
environmental effects assessments for research, development,
acquisition, testing, and evaluation as well as Fleet at-sea training,
exercises, maintenance, and support activities.
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).
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.

Navy Research and Development

Navy Funded--Both the LMR and ONR Research and Development (R&D)
programs periodically fund projects within the NWTT 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/military.htm) and
the Fleet's new marine species monitoring Web site (http://www.navymarinespeciesmonitoring.us/regions/pacific/current-projects/).
In addition, the Navy's Range Complex monitoring during training and
testing activities is coordinated with the Research and Development
monitoring in a given region to leverage research objectives, assets,
and studies where possible under the ICMP.
The integration between the Navy's new LMR research and development
program and related range complex monitoring will continue and improve
during the applicable period of the rulemaking with results presented
in NWTT annual monitoring reports.
Other National Department of Defense Funded Initiatives--Strategic
Environmental Research and Development Program (SERDP) and
Environmental Security Technology Certification Program (ESTCP) are the
DoD'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 that are common to all of the
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.

Adaptive Management

The final regulations governing the take of marine mammals
incidental to Navy training and testing activities in the NWTT 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 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.

Proposed 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

[[Page 31785]]

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).
In the event that an injured, stranded, or dead marine mammal is
found by the Navy that is not in the vicinity of, or during or shortly
after MFAS, HFAS, or underwater explosive detonations, the Navy will
report the same information as listed above as soon as operationally
feasible and clearance procedures allow.

Annual Monitoring Plan Reports

The Navy shall submit an annual report of the NWTT Monitoring Plan
describing the implementation and results of the NWTT Monitoring Plan
from the previous calendar year. 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 NWTT Monitoring Plan
shall, at a minimum, provide the same marine mammal observation data
required in Sec. 218.145. The report shall be submitted either 90 days
after the calendar year, or 90 days after the conclusion of the
monitoring year to be determined by the Adaptive Management process.
The NWTT Monitoring Plan Report may be provided to NMFS within a
larger report that includes the required Monitoring Plan reports from
multiple range complexes and study areas (the multi-Range Complex
Annual Monitoring Report). Such a report would describe progress of
knowledge made with respect to monitoring plan study questions across
all Navy ranges associated with the ICMP. Similar study questions shall
be treated together so that progress on each topic shall be summarized
across all Navy ranges. The report need not include analyses and
content that does not provide direct assessment of cumulative progress
on the monitoring plan study questions.

Annual Exercise and Testing Reports

The Navy shall submit preliminary reports detailing the status of
authorized sound sources within 21 days after the anniversary of the
date of issuance of the LOA. The Navy shall submit detailed reports 3
months after the anniversary of the date of issuance of the LOA. The
detailed annual reports shall describe the level of training and
testing conducted during the reporting period, and a summary of sound
sources used (total annual hours or quantity [per the LOA] of each bin
of sonar or other non-impulsive source; total annual number of each
type of explosive exercises; total annual expended/detonated rounds
[missiles, bombs, etc.] for each explosive bin; and improved Extended
Echo-Ranging System (IEER)/sonobuoy summary, including total number of
IEER events conducted in the Study Area, total expended/detonated
rounds (buoys), and total number of self-scuttled IEER rounds. The
analysis in the detailed reports will be based on the accumulation of
data from the current year's report and data collected from previous
reports.

5-Year Close-Out Exercise and Testing Report

This report will be included as part of the 2020 annual exercise or
testing report. This report will provide the annual totals for each
sound source bin with a comparison to the annual allowance and the 5-
year total for each sound source bin with a comparison to the 5-year
allowance. Additionally, if there were any changes to the sound source
allowance, this report will include a discussion of why the change was
made and include the analysis to support how the change did or did not
result in a change in the SEIS and final rule determinations. The
report will be submitted 3 months after the expiration of the rule.
NMFS will submit comments on the draft close-out report, if any, within
3 months of receipt. The report will be considered final after the Navy
has addressed NMFS' comments, or 3 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, the potential effects to marine mammals from MFAS/HFAS and
underwater detonation of explosives will be related 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

[[Page 31786]]

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].'' It is important to note that, as Level
B harassment is interpreted here and quantified by the behavioral
thresholds described below, the fact that a single behavioral pattern
(of unspecified duration) is abandoned or significantly altered and
classified as a Level B take does not mean, necessarily, that the
fitness of the harassed individual is affected either at all or
significantly, or that, for example, a preferred habitat area is
abandoned. Further analysis of context and duration of likely exposures
and effects is necessary to determine the impacts of the estimated
effects on individuals and how those may translate to population level
impacts, and is included in the Analysis and Negligible Impact
Determination.

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.
As the statutory definition is currently applied, a wide range of
behavioral reactions may qualify as Level B harassment under the MMPA,
including but not limited to avoidance of the sound source, temporary
changes in vocalizations or dive patters, temporary avoidance of an
area, or temporary disruption of feeding, migrating, or reproductive
behaviors. The estimates calculated by the Navy using the acoustic
thresholds do not differentiate between the different types of
potential behavioral reactions. Nor do the estimates provide
information regarding the potential fitness or other biological
consequences of the reactions on the affected individuals. We therefore
consider the available scientific evidence to determine the likely
nature of the modeled behavioral responses and the potential fitness
consequences for affected individuals
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 can fall into the Level A harassment category
(unless they further rise to the level of serious injury or mortality):
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; Fern[aacute]ndez et al., 2012), 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. Recent modeling
by Kvadsheim et al. (2012) determined that while behavioral and
physiological responses to sonar have the potential to result in bubble
formation, the actual observed behavioral responses of cetaceans to
sonar did not imply any significantly increased risk over what may
otherwise occur normally in individual marine mammals.
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

[[Page 31787]]

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. Vessel or ordnance strike is
not anticipated with the Navy activities in the Study Area.

Take Thresholds

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 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
thresholds 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 thresholds 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).
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 the Navy is not specifically
required to estimate those numbers; however, the more specifically the
affected marine mammal responses can be estimated, 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) do
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 and impulsive thresholds to TTS and PTS for
marine mammals. A detailed explanation of how these thresholds were
derived is provided in the NWTT DEIS/OEIS Criteria and Thresholds
Technical Report (Finneran and Jenkins, 2012) and summarized in Chapter
6 of the LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm).

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-
Mustelidae In-water.................. Sea otters............. sec(OWI). sec(OWI)
----------------------------------------------------------------------------------------------------------------
LFII, MFII, HFII: New compound Type II weighting functions; PWI, OWI: Original Type I (Southall et al., 2007)
for pinniped and mustelid in water.

[[Page 31788]]

[GRAPHIC] [TIFF OMITTED] TP03JN15.018

Level B Harassment Risk Function (Behavioral Harassment)

As the statutory definition is currently applied, a wide range of
behavioral reactions may qualify as Level B harassment under the MMPA,
including but not limited to avoidance of the sound source, temporary
changes in vocalizations or dive patters, temporary avoidance of an
area, or temporary disruption of feeding, migrating, or reproductive
behaviors. The estimates calculated by the Navy using the acoustic
thresholds do not differentiate between the different types of
potential behavioral reactions. Nor do the estimates provide
information regarding the potential fitness or other biological
consequences of the reactions on the affected individuals. We therefore
consider the available scientific evidence to determine the likely
nature of the modeled behavioral responses and the potential fitness
consequences for affected individuals.
Behavioral Response Criteria for Non-Impulsive Sound from Sonar and
other

[[Page 31789]]

Active Sources--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 means that there is support for alternate
approaches for estimating 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. In January 2009, NMFS issued three
final rules governing the incidental take of marine mammals (within
Navy's Hawaii Range, Southern California Training and Testing Range,
and Atlantic Fleet Active Sonar Training complexes) 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 EISs on the Surveillance Towed Array
Sensor System Low Frequency Active (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. It is also worth specifically
noting that while context is very important in marine mammal response,
given otherwise equivalent context, the severity of a marine mammal
behavioral response is also expected to increase with received level
(Houser and Moore, 2014). 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 1 and 2 of the LOA application) 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] TP03JN15.019

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 January 2014 NWTT DEIS/OEIS and previous Navy
documents listed above.
The harbor porpoise and beaked whales have unique criteria based on
specific data that show these animals to be especially sensitive to
sound. Harbor porpoise and beaked whale non-impulsive behavioral
criteria are used unweighted--without weighting the received level
before comparing it to the threshold (see Finneran and Jenkins, 2012).
It has been speculated for some time that beaked whales might have
unusual sensitivities to sonar sound due to their likelihood of
stranding in conjunction with mid-frequency sonar 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 AUTEC 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 actual naval mid-frequency
sonar in real anti-submarine training scenarios as well as playbacks of
killer whale vocalizations, and other anthropogenic sounds. Tyack et
al. (2011) report that, in reaction to sonar playbacks, most beaked
whales stopped echolocating, made long slow ascent, and moved away from
the sound. During an exercise using mid-frequency sonar, beaked whales
avoided the sonar acoustic footprint at a distance where the received
level was ``around 140 dB'' (SPL) and once the exercise ended, beaked
whales re-inhabited the center of exercise area within 2-3 days (Tyack
et al., 2011). The Navy has therefore adopted an unweighted 140 dB re 1
[mu]Pa SPL threshold for significant behavioral effects for all beaked
whales (family: Ziphiidae).
Since the development of the criterion, analysis of the data the
2010 and 2011 field seasons of the southern California Behavioral
Responses Study have been published. The study, DeRuiter et al.
(2013b), provides similar evidence of Cuvier's beaked whale
sensitivities to sound based on two controlled exposures. Two whales,
one in each season, were tagged and exposed to simulated mid-frequency
active sonar at distances of 3.4-9.5 km. The 2011 whale was also
incidentally exposed to mid-frequency active sonar from a distant naval
exercise (approximately 118 km away). Received levels from the mid-
frequency active sonar signals during the controlled and incidental
exposures were calculated as 84-144 and 78-106 dB re 1 [mu]Pa rms,
respectively. Both whales showed responses to the controlled exposures,
ranging from initial orientation changes to avoidance responses
characterized by energetic fluking and swimming away from the source.
However, the authors did not detect similar responses to incidental
exposure to distant naval sonar exercises at comparable received
levels, indicating that context of the exposures (e.g., source
proximity, controlled source ramp-up) may have been a significant
factor. Because the

[[Page 31790]]

sample size was limited (controlled exposures during a single dive in
both 2010 and 2011) and baseline behavioral data was obtained from
different stocks and geographic areas (i.e., Hawaii and Mediterranean
Sea), and the responses exhibited to controlled exposures were not
exhibited by an animal exposed to some of the same received levels of
real sonar exercises, the Navy relied on the studies at the AUTEC that
analyzed beaked whale responses to actual naval exercises using mid-
frequency active sonar to evaluate potential behavioral responses by
beaked whales to proposed training and testing activities using sonar
and other active acoustic sources.
The information currently available regarding harbor porpoises
suggests a very low threshold level of response for both captive and
wild animals. Threshold levels at which both captive (Kastelein et al.,
2000; Kastelein et al., 2005; Kastelein et al., 2006; Kastelein et al.,
2008) and wild harbor porpoises (Johnston, 2002) responded to sound
(e.g., acoustic harassment devices, acoustic deterrent devices, or
other non-impulsive sound sources) are very low (e.g., approximately
120 dB re 1 [mu]Pa). Therefore, a SPL of 120 dB re 1 [mu]Pa is used in
this analysis as a threshold for predicting behavioral responses in
harbor porpoises instead of the risk functions used for other species
(i.e., we assume for the purpose of estimating take that all harbor
porpoises exposed to 120 dB or higher MFAS/HFAS will be taken by Level
B behavioral harassment).
Behavioral Response Criteria for Impulsive Sound from Explosions--
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. This reasoning was applied to previous shock
trials (63 FR 230; 66 FR 87; 73 FR 143) and is extended to these Phase
II criteria. Behavioral thresholds for impulsive sources are summarized
in Table 15 and further detailed in the 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 a Type II weighted sound pressure level of 167 dB SPL would
equal a 164 dB sound exposure level, and would not be predicted as
leading to a significant behavioral response (take) in MF or HF
cetaceans. However, if the five 0.1 second pulses are treated as a 5
second exposure, it would yield an adjusted SEL of approximately 169
dB, exceeding the behavioral threshold of 167 dB SEL. For impulses
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
weighting functions (detailed in Chapter 6 of the LOA application) are
applied to the received sound level before being compared to the
threshold.

Table 15--Behavioral Thresholds for Impulsive Sound
----------------------------------------------------------------------------------------------------------------
Impulsive behavioral threshold for > 2
Hearing group pulses/24 hours Onset TTS
----------------------------------------------------------------------------------------------------------------
Low-Frequency Cetaceans.................. 167 dB SEL (LFII) 172 dB SEL (MFII) or 224 dB
Peak SPL.
Mid-Frequency Cetaceans.................. 167 dB SEL (MFII)
High-Frequency Cetaceans................. 141 dB SEL (HFII) 146 dB SEL (HFII) or 195 dB
Peak SPL.
Phocid Seals (in water).................. 172 dB SEL (PWI) 177 dB SEL (PWI) or 212 dB
Peak SPL.
Otariidae & Mustelidae (in water)........ 195 dB SEL (OWI) 200 dB SEL (OWI) or 212 dB
Peak SPL.
----------------------------------------------------------------------------------------------------------------
Notes: (1) LFII, MFII, HFII are New compound Type II weighting functions; PWI, OWI = Original Type I (Southall
et al. 2007) for pinniped and mustelid in water (see Finneran and Jenkins 2012). (2) SEL = re 1 [micro]Pa\2\-
s; SPL = re 1 [micro]Pa, SEL = Sound Exposure Level, dB = decibel, SPL = Sound Pressure Level.

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. The most appropriate unit of metric for this
type of analysis is density, which is described as the number of
animals present per unit area.
There is no single source of density data for every area, species,
and season because of the fiscal costs, resources, and effort involved
in NMFS providing enough survey coverage to sufficiently estimate
density. Therefore, to characterize the marine species density for
large areas such as the Study Area, the Navy needed to compile data
from multiple sources. Each data source may use different methods to
estimate density, of which, uncertainty in the estimate can be directly
related to the method applied. To develop a database of marine species
density estimates, the Navy, in consultation with NMFS experts, adopted
a protocol to select the best available data sources (including
habitat-based density models, line-transect analyses, and peer-reviewed
published studies) based on species, area, and season (see the Navy's
Pacific Marine Species Density Database Technical Report; U.S.
Department of the Navy, 2014b). The resulting Geographic Information
System (GIS) database includes one single spatial and seasonal density
value for every marine mammal present within the Study Area.
The Navy Marine Species Density Database includes a compilation of
the best available density data from several primary sources and
published works

[[Page 31791]]

including survey data from NMFS within the U.S. EEZ. NMFS is the
primary agency responsible for estimating marine mammal and sea turtle
density within the U.S. EEZ. NMFS publishes annual SARs for various
regions of U.S. waters and covers all stocks of marine mammals within
those waters. The majority of species that occur in the Study Area are
covered by the Pacific Region Stock Assessment Report (Carretta et al.,
2014), with a few species (e.g., Steller sea lions) covered by the
Alaska Region Stock Assessment Report (Allen and Angliss, 2014). Other
independent researchers often publish density data or research covering
a particular marine mammal species, which is integrated into the NMFS
SARs.
For most cetacean species, abundance is estimated using line-
transect methods that employ a standard equation to derive densities
based on sighting data collected from systematic ship or aerial
surveys. More recently, habitat-based density models have been used
effectively to model cetacean density as a function of environmental
variables (e.g., Redfern et al., 2006; Barlow et al., 2009; Becker et
al., 2010; Becker et al., 2012a; Becker et al., 2012b; Becker, 2012c;
Forney et al., 2012). Where the data supports habitat based density
modeling, the Navy's database uses those density predictions. Habitat-
based density models allow predictions of cetacean densities on a finer
spatial scale than traditional line-transect analyses because cetacean
densities are estimated as a continuous function of habitat variables
(e.g., sea surface temperature, water depth). Within most of the
world's oceans, however there have not been enough systematic surveys
to allow for line-transect density estimation or the development of
habitat models. To get an approximation of the cetacean species
distribution and abundance for unsurveyed areas, in some cases it is
appropriate to extrapolate data from areas with similar oceanic
conditions where extensive survey data exist. Habitat Suitability
Indexes or Relative Environmental Suitability have also been used in
data-limited areas to estimate occurrence based on existing
observations about a given species' presence and relationships between
basic environmental conditions (Kaschner et al., 2006).
Methods used to estimate pinniped at-sea density are generally
quite different than those described above for cetaceans. Pinniped
abundance is generally estimated via shore counts of animals at known
rookeries and haulout sites. For example, for species such as the
California sea lion, population estimates are based on counts of pups
at the breeding sites (Carretta et al., 2014). However, this method is
not appropriate for other species such as harbor seals, whose pups
enter the water shortly after birth. Population estimates for these
species are typically made by counting the number of seals ashore and
applying correction factors based on the proportion of animals
estimated to be in the water (Carretta et al., 2014). Population
estimates for pinniped species that occur in the Study Area are
provided in the Pacific Region Stock Assessment Report (Carretta et
al., 2014). Translating these population estimates to in-water
densities presents challenges because the percentage of seals or sea
lions at sea compared to those on shore is species-specific and depends
on gender, age class, time of year (molt and breeding/pupping seasons),
foraging range, and for species such as harbor seal, time of day and
tide level. These parameters were identified from the literature and
used to establish correction factors which were then applied to
estimate the proportion of pinnipeds that would be at sea within the
Study Area for a given season.
Density estimates for each species in the Study Area, and the
sources for these estimates, are provided in Chapter 6 of the LOA
application and in the Navy's Pacific Marine Species Density Database
Technical Report (U.S. Department of the Navy, 2014b).

Quantitative Modeling To Estimate Take for Impulsive and Non-Impulsive
Sound

The Navy performed a quantitative analysis to estimate the number
of marine mammals that could be affected by acoustic sources or
explosives used during Navy training and testing activities. Inputs to
the quantitative analysis include 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 harassments. The model calculates
sound energy propagation from sonar, other active acoustic sources, and
explosives during naval activities; the sound or impulse received by
animat (virtual representation of an animal) 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
and adjusted to consider animal avoidance (i.e., swimming away from
sonar or other active sources and away from multiple explosions to
avoid repeated high level sound exposures) and implementation of
mitigation measures, resulting in final estimates of potential effects
due to Navy training and testing.
Various 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 influence the result. Assumptions in
previous and current 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. El Ni[ntilde]o
Southern Oscillation events of the ocean-atmosphere system are an
example of dynamic change where unusually warm or cold ocean
temperatures are likely to redistribute marine life and alter the
propagation of underwater sound energy. Previous Navy modeling
therefore made some assumptions 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 variable bathymetry and an animal's likely presence
at various depths.
The Navy has developed new software tools, up to date marine mammal
density data, and other oceanographic data for the quantification of
estimated acoustic impacts to 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. The new model, NAEMO, is the standard
model now used by the Navy to estimate the potential acoustic effects
of Navy training and testing activities on marine mammals. Although
this more complex computer modeling approach accounts

[[Page 31792]]

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 mitigation zone
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. 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. This
final, post-analysis step in the modeling process is meant to better
quantify the predicted effects by accounting for likely animal
avoidance behavior and implementation of standard Navy mitigations.
The incorporation of mitigation factors for the reduction of
predicted effects used a conservative approach (erring on the side of
overestimating the number of effects) since reductions as a result of
implemented mitigation were only applied to those events having a very
high likelihood of detecting marine mammals. It is important to note
that there are additional protections offered by mitigation procedures
which will further reduce effects to marine mammals, but these are not
considered in the quantitative adjustment of the model predicted
effects.
The steps of the quantitative analysis of acoustic effects, the
values and assumptions that went into the Navy's model, and the
resulting ranges to effects are detailed in Chapter 6 (Section 6.5) of
the LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm). Details of the model's processes and the description and
derivation of the inputs are presented in the Navy's Determination of
Acoustic Effects technical Report (Marine Species Modeling Team, 2013).
The post-model analysis, which considers the potential for avoidance
and highly effective mitigation during the use of sonar and other
active acoustic sources and explosives, is described in Section 6.5 of
the LOA application. A detailed explanation of the post-model acoustic
effect analysis quantification process is also provided in the
technical report Post-Model Quantitative Analysis of Animal Avoidance
Behavior and Mitigation Effectiveness for the Northwest Training and
Testing (U.S. Department of the Navy, 2014c).

Analysis of Guadalupe Fur Seal Exposures

While there are past and current reports of Guadalupe fur seal
strandings in the Pacific Northwest, NMFS does not have at-sea
Guadalupe fur seal sightings from which to derive a density estimate.
For the NWTT DEIS/OEIS, the Navy elected to take a subset of Northern
fur seal modeled exposures as a surrogate for Guadalupe fur seals.
Essentially, a fraction of the northern fur seal modeled exposures from
the Navy's acoustic effects analysis were used for Guadalupe fur seals
exposures based on a comparative ratio of expected occurrence offshore
in the NWTT Study Area for northern fur seals and Guadalupe fur seals
(based on NMFS stranding records). Northern fur seal at-sea densities
described in the Navy's Pacific Marine Species Density Database
Technical Report (U.S. Department of the Navy, 2014b) were derived as a
single NWTT Study Area wide layer (0.106 animals/km\2\ winter and
spring, and 0.082 animals/km\2\ summer and fall). The estimated (not
modeled) results for Guadalupe fur seals were incorporated directly
into the NWTT DEIS/OEIS (and original December 2013 NWTT LOA
application).
This initial analysis, however, was done without consideration of
the likely differences in biological at-sea distributions of both
northern fur seals and Guadalupe fur seals. Northern fur seals have a
documented highly pelagic distribution through the offshore waters of
the Study Area where the majority of Navy training would occur (Davis
et al., 2008, NMFS 2007, Lee et al., 2014, Pelland et al., 2014,
Sterling et al., 2014). This was the justification for the NWTT Study
Area wide single density values by season (U.S. Department of the Navy,
2014b). Within the Pacific Northwest, Guadalupe fur seals are more
likely to be coastally distributed given their extralimital at-sea
occurrence and associated stranding records (Lambourn et al., 2012).
The Navy, therefore, has proposed to modify the Guadalupe fur seal
take number in the NWTT Final EIS/OEIS and has revised the LOA
application to account for species-specific biological differences in
at-sea distributions within the NWTT Study Area. This would limit
Guadalupe fur seal exposures as compared to the process described
above, as well as more realistically reflect impacts from offshore Navy
training and testing events. The first step in this reanalysis was an
examination of the exact Navy events modeled in NAEMO that generated
exposures for Northern fur seals. The Navy then analyzed the potential
for co-occurrence of the activities resulting in exposures with the
Guadalupe fur seal's distribution to determine if the currently
predicted exposures should be modified. For training, the Navy asserted
that TRACKEX events typically conducted >50 nm from shore in the NWTT
Study Area would have limited to no co-occurrence with Guadalupe fur
seals, and would not result in training related MMPA exposures. TRACKEX
events account for 82 percent of exposures under the NWTT DEIS/OEIS
preferred alternative (Table 16). The remaining 18 percent of exposures
were from offshore submarine sonar maintenance and offshore surface
ship sonar maintenance. While these events would also likely be further
offshore, the Navy cannot totally exclude such events from at-sea co-
occurring with the Guadalupe fur seal. For testing, the Navy asserts
that countermeasure testing and littoral combat ship (LCS) mission
package testing-ASW typically conducted >50 nm from shore in the NWTT
Study Area would have limited to no co-occurrence with Guadalupe fur
seals and would not result in testing MMPA exposures. Countermeasure
testing and LCS mission package testing-ASW events account for 92
percent of exposures under the NWTT EIS/OEIS preferred alternative
(Table 16). The remaining 8 percent of exposures were from various
testing activities with the majority (5.6 percent) from ASW-guided
missile destroyer (DDG)-attack submarine (SSN) testing which the Navy
cannot totally exclude from at-sea co-occurrence with the Guadalupe fur
seal.
Based on the results of this analysis, the Navy is modifying
current NWTT EIS/OEIS take tables and has revised the LOA application
to account for a percentage decrease in Guadalupe fur seal take
requests. For this proposed rulemaking, the Guadalupe fur seal Level B
behavioral take request for training has changed from ``37'' to ``7''
(Table 18) and for testing has changed from ``27'' to ``3'' (Table 21).

[[Page 31793]]

Table 16--Phase II NAEMO Modeled Exposures to Northern Fur Seal in Relationship to Navy Training Events Similar
to NWTRC Phase I Events and for NWTT
----------------------------------------------------------------------------------------------------------------
Dec 2013 Revised Navy
Percentage of Dec 2013 Proposed Aug recommended
NWTT events applicable to the Northern fur Guadalupe fur 2014 Guadalupe fur Rational
NWTT LOA application seal modeled seal take Modification seal take
exposures request amount request
----------------------------------------------------------------------------------------------------------------
Training Activities Deemed to Not Have High Probability Of Overlap With Guadalupe Fur Seals
----------------------------------------------------------------------------------------------------------------
TRACKEX (Maritime patrol 82 37 -30 7 82% of exposures
aircraft, submarine, surface from TRACKEX,
ship). therefore 30
exposures (82%
of 37) can be
reduced.
----------------------------------------------------------------------------------------------------------------
Training Activities That Could Have Overlap With Guadalupe Fur Seals
----------------------------------------------------------------------------------------------------------------
Submarine sonar maintenance... 11
Surface ship sonar maintenance 7
----------------------------------------------------------------------------------------------------------------
Testing Activities Deemed to Not Have High Probability Of Overlap With Guadalupe Fur Seals
----------------------------------------------------------------------------------------------------------------
NAVSEA countermeasure testing. 81 27 -24 3 92% of exposures
NAVSEA LCS mission package 11. from
testing--ASW. countermeasure
testing and LCS
package testing-
ASW, therefore
24 exposures
(92% of 27) can
be reduced.
----------------------------------------------------------------------------------------------------------------
Testing Activities That Could Have Overlap With Guadalupe Fur Seals
----------------------------------------------------------------------------------------------------------------
NAVSEA ASW-DDG-SSN............ 6
Various others................ < 1
----------------------------------------------------------------------------------------------------------------

Analysis of Harbor Seal Exposures

For harbor seals in the inland waters portion of the Study Area,
there was a change to the Washington Inland Waters stock in 2014
subsequent to the presentation of the January 2014 NWTT DEIS/OEIS to
the public. Based on DNA evidence, the single Inland Waters stock was
broken up into three new stocks, designated the Hood Canal, the
Washington Northern Inland Waters, and the Southern Puget Sound stocks
(Carretta et al., 2014). Evidence from tagging data (London et al.,
2012) suggests the Hood Canal stock generally does not forage beyond
Hood Canal. The Navy has assumed that acoustic effects modeling for
locations in Hood Canal and Dabob Bay can therefore be accurately
assigned to the Hood Canal stock. For the Washington Northern Inland
Waters stock and the Southern Puget Sound stock and because it is
possible that these stocks overlap while foraging, modeled acoustic
effects to harbor seals in the inland waters portion of the Study Area
(excluding Hood Canal and Dabob Bay) were therefore assigned to the
appropriate stock using a derived ratio based on the abundance
estimates for the two stocks as reported in the 2013 Pacific Stock
Assessment Report (Carretta et al. (2014); Washington Northern Inland
Waters stock: n = 11,036; Southern Puget Sound stock: n = 1,568). The
ratio of the Washington Northern Inland Waters stock (0.88) to that of
the Southern Puget Sound stock (0.12) was then used to prorate the
total modeled exposures in order to estimate acoustic exposures for
each of these stocks in the inland waters portion of the Study Area.
As a result of the changes to the harbor seal abundance and haulout
assumptions for the Hood Canal stock, for this proposed rulemaking the
harbor seal Level B behavioral take request has increased by an
additional 417 takes for training (Table 18) and an additional 52,970
takes (Table 21) for testing. The Level A take request has increased an
additional 4 takes for training (Table 18) and an additional 61 takes
for testing (Table 21).

Take Request

The January 2014 NWTT 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 potential
stressors associated with these activities included the following:
Acoustic (sonar and other active non-impulse sources,
explosives, 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
Secondary stressors (sediments and water quality).
NMFS has determined that two 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) and (2) impulsive stressors
(explosives). Non-impulsive and impulsive stressors have the potential
to result in incidental takes of marine mammals by harassment, injury,
or mortality. NMFS also considered the potential for vessel strikes to
impact marine mammals, and that assessment is presented below.

Training Activities

A detailed analysis of effects due to marine mammal exposures to
impulsive and non-impulsive sources in the Study Area is presented in
Chapter 6 of the LOA application. Based on the model and post-model
analysis described in Chapter 6 of the LOA application, Table 17
summarizes the Navy's final take request for training activities for a
year (a 12-month period) and the summation over a 5-year period (annual
events occurring five times and the non-annual event occurring three
times). The Civilian Port Defense exercise is a non-

[[Page 31794]]

annual event and is analyzed as occurring every other year, or three
times during the 5-year period considered in this analysis. Annual
totals presented in the tables are the summation of all annual events
plus all the proposed non-annual events occurring in a 12-month period
as a maximum year.

Table 17--Summary of Annual and 5-Year Take Requests for NWTT Training
Activities
------------------------------------------------------------------------
Training activities
---------------------------------
MMPA category Source Annual 5-Year
authorization authorization
sought sought
------------------------------------------------------------------------
Level A.............. Impulsive and.. 11--Species 55--Species
Non-Impulsive.. specific data specific data
shown in shown in
Tables 16 and Tables 16 and
17. 17.
Level B.............. Impulsive and.. 107,459--Specie 533,543--Specie
Non-Impulsive.. s specific s specific
data shown in data shown in
Tables 16 and Tables 16 and
17. 17.
------------------------------------------------------------------------

Impulsive and Non-Impulsive Sources

Table 18 provides the Navy's take request for training activities
by species from the acoustic effects modeling estimates. The numbers
provided in the annual columns are the totals for a maximum year (i.e.,
a year in which a Civilian Port Defense Occurs). Table 19 provides the
contribution to the maximum year total (1,876 Level B exposures)
resulting from the biennial Civilian Port Defense exercise. The 5-year
totals presented assume the biennial event would occur three times over
the 5-year period (in the first, third, and fifth years). Derivations
of the numbers presented in Tables 18 and 19 are described in more
detail within Chapter 6 of the LOA application. There are no
mortalities predicted for any training activities resulting from the
use of impulsive or non-impulsive sources. Values shown in Table 18
also include Level B values from non-annual Civilian Port Defense
training events.

Table 18--Species-Specific Take Requests From Modeling and Post-Model Estimates of Impulsive and Non-Impulsive
Source Effects for all Training Activities
----------------------------------------------------------------------------------------------------------------
Annual 5-Year
Species Stock ---------------------------------------------------
Level B Level A Level B Level A
----------------------------------------------------------------------------------------------------------------
North Pacific right whale........... Eastern North Pacific. 0 0 0 0
Humpback whale...................... Central North Pacific. 0 0 0 0
California, Oregon, & 12 0 60 0
Washington.
Blue whale.......................... Eastern North Pacific. 5 0 25 0
Fin whale........................... Northeast Pacific..... 0 0 0 0
California, Oregon, & 25 0 125 0
Washington.
Sei whale........................... Eastern North Pacific. 0 0 0 0
Minke whale......................... Alaska................ 0 0 0 0
California, Oregon, & 18 0 90 0
Washington.
Gray whale.......................... Eastern North Pacific. 6 0 30 0
Western North Pacific. 0 0 0 0
Sperm whale......................... North Pacific......... 0 0 0 0
California, Oregon, & 81 0 405 0
Washington.
Kogia (spp.)........................ California, Oregon, & 73 0 365 0
Washington.
Killer whale........................ Alaska Resident....... 0 0 0 0
Northern Resident..... 0 0 0 0
West Coast Transient.. 9 0 39 0
East N. Pacific 13 0 65 0
Offshore.
East N. Pacific 2 0 6 0
Southern Resident.
Short-finned pilot whale............ California, Oregon, & 0 0 0 0
Washington.
Short-beaked common dolphin......... California, Oregon, & 734 0 3,670 0
Washington.
Bottlenose dolphin.................. California, Oregon, & 0 0 0 0
Washington.
Striped dolphin..................... California, Oregon, & 22 0 110 0
Washington.
Pacific white-sided dolphin......... North Pacific......... 0 0 0 0
California, Oregon, & 3,482 0 17,408 0
Washington.
Northern right whale dolphin........ California, Oregon, & 1,332 0 6,660 0
Washington.
Risso's dolphin..................... California, Oregon, & 657 0 3,285 0
Washington.
Harbor porpoise..................... Southeast Alaska...... 0 0 0 0
Northern OR/WA Coast.. 35,006 0 175,030 0
Northern CA/Southern 52,509 0 262,545 0
OR.
WA Inland Waters...... 1,417 1 4,409 5
Dall's porpoise..................... Alaska................ 0 0 0 0
California, Oregon, & 3,732 4 18,188 20
Washington.
Cuvier's beaked whale............... Alaska................ 0 0 0 0
California, Oregon, & 353 0 1,765 0
Washington.
Baird's beaked whale................ Alaska................ 0 0 0 0
California, Oregon, & 591 0 2,955 0
Washington.
Mesoplodon beaked whales............ California, Oregon, & 1,417 0 7,085 0
Washington.
Steller sea lion.................... Eastern U.S........... 404 0 1,986 0
Guadalupe fur seal.................. San Miguel Island..... 7 0 35 0
California sea lion................. U.S. Stock............ 814 0 4,038 0
Northern fur seal................... Eastern Pacific....... 2,495 0 12,475 0

[[Page 31795]]

California............ 37 0 185 0
Northern elephant seal.............. California Breeding... 1,271 0 6,353 0
Harbor seal......................... Southeast Alaska 0 0 0 0
(Clarence Strait).
OR/WA Coast........... 0 0 0 0
California............ 0 0 0 0
WA Northern Inland 427 4 1,855 20
Waters.
Southern Puget Sound.. 58 0 252 0
Hood Canal............ 452 2 2,054 10
----------------------------------------------------------------------------------------------------------------

Table 19--Training Exposures Specific to the Biennial Civilian Port
Defense Exercise
[Values provided for informational purposes and are included in Table 18
species-specific totals]
------------------------------------------------------------------------
Biennial
Species Stock -------------------------
Level B Level A
------------------------------------------------------------------------
North Pacific right whale.... Eastern North 0 0
Pacific.
Humpback whale............... Central North 0 0
Pacific.
California, 0 0
Oregon, &
Washington.
Blue whale................... Eastern North 0 0
Pacific.
Fin whale.................... Northeast 0 0
Pacific.
California, 0 0
Oregon, &
Washington.
Sei whale.................... Eastern North 0 0
Pacific.
Minke whale.................. Alaska......... 0 0
California, 0 0
Oregon, &
Washington.
Gray whale................... Eastern North 0 0
Pacific.
Western North 0 0
Pacific.
Sperm whale.................. North Pacific.. 0 0
California, 0 0
Oregon, &
Washington.
Kogia (spp.)................. California, 0 0
Oregon, &
Washington.
Killer whale................. Alaska Resident 0 0
Northern 0 0
Resident.
West Coast 3 0
Transient.
East N. Pacific 0 0
Offshore.
East N. Pacific 2 0
Southern
Resident.
Short-finned pilot whale..... California, 0 0
Oregon, &
Washington.
Short-beaked common dolphin.. California, 0 0
Oregon, &
Washington.
Bottlenose dolphin........... California, 0 0
Oregon, &
Washington.
Striped dolphin.............. California, 0 0
Oregon, &
Washington.
Pacific white-sided dolphin.. North Pacific.. 0 0
California, 1 0
Oregon, &
Washington.
Northern right whale dolphin. California, 0 0
Oregon, &
Washington.
Risso's dolphin.............. California, 0 0
Oregon, &
Washington.
Harbor porpoise.............. Southeast 0 0
Alaska.
Northern OR/WA 0 0
Coast.
Northern CA/ 0 0
Southern OR.
WA Inland 1,338 0
Waters.
Dall's porpoise.............. Alaska......... 0 0
California, 236 0
Oregon, &
Washington.
Cuvier's beaked whale........ Alaska......... 0 0
California, 0 0
Oregon, &
Washington.
Baird's beaked whale......... Alaska......... 0 0
California, 0 0
Oregon, &
Washington.
Mesoplodon beaked whales..... California, 0 0
Oregon, &
Washington.
Steller sea lion............. Eastern U.S.... 17 0
Guadalupe fur seal........... San Miguel 0 0
Island.
California sea lion.......... U.S. Stock..... 16 0
Northern fur seal............ Eastern Pacific 0 0
California..... 0 0
Northern elephant seal....... California 1 0
Breeding.
Harbor seal.................. Southeast 0 0
Alaska
(Clarence
Strait).
OR/WA Coast.... 0 0
California..... 0 0
WA Northern 140 0
Inland Waters.
Southern Puget 19 0
Sound.
Hood Canal..... 103 0
------------------------------------------------------------------------

[[Page 31796]]

Vessel Strike

There has never been a vessel strike to marine mammals during any
training activities in the Study Area. A detailed analysis of strike
data is contained in Section 6.7 (Estimated Take of Large Whales by
Navy Vessel Strike) of the LOA application. The Navy does not
anticipate vessel strikes to marine mammals within the Study Area, nor
were takes by injury or mortality resulting from vessel strike
predicted in the Navy's analysis. Therefore, takes by injury or
mortality resulting from vessel strikes are not authorized by NMFS in
this proposed rule. However, the Navy has proposed measures (see
Proposed Mitigation) to mitigate potential impacts to marine mammals
from vessel strikes during training activities in the Study Area.

Testing Activities

A detailed analysis of effects due to marine mammal exposures to
impulsive and non-impulsive sources in the Study Area is presented in
Chapter 6 of the LOA application. Based on the model and post-model
analysis described in Chapter 6 of the LOA application, Table 20
summarizes the Navy's final take request for testing activities for an
annual (12-month) period and the summation over a 5-year period. There
are no non-annual testing events.

Table 20--Summary of Annual and 5-Year Take Requests for NWTT Testing
Activities
------------------------------------------------------------------------
Testing activities
---------------------------------
MMPA category Source Annual 5-Year
authorization authorization
sought sought
------------------------------------------------------------------------
Level A.............. Impulsive and 176--Species 880--Species
Non-Impulsive. specific data specific data
shown in shown in
Tables 18 and Tables 18 and
19. 19.
Level B.............. Impulsive and 139,815--Specie 699,075--Specie
Non-Impulsive. s specific s specific
data shown in data shown in
Tables 18 and Tables 18 and
19. 19.
------------------------------------------------------------------------

Impulsive and Non-Impulsive Sources

Table 21 summarizes the Navy's take request for testing activities
by species. There are no non-annual testing events. Derivation of these
values is described in more detail within Chapter 6 of the LOA
application. There are no mortalities predicted for any testing
activities based on the analysis of impulsive and non-impulsive
sources.

Table 21--Species-Specific Take Requests From Modeling and Post-Model Estimates of Impulsive and Non-Impulsive
Source Effects for All Testing Activities
----------------------------------------------------------------------------------------------------------------
Annual 5-Year
Species Stock ---------------------------------------------------
Level B Level A Level B Level A
----------------------------------------------------------------------------------------------------------------
North Pacific right whale........... Eastern North Pacific. 0 0 0 0
Humpback whale...................... Central North Pacific. 1 0 5 0
California, Oregon, & 44 0 220 0
Washington.
Blue whale.......................... Eastern North Pacific. 6 0 30 0
Fin whale........................... Northeast Pacific..... 2 0 10 0
California, Oregon, & 34 0 170 0
Washington.
Sei whale........................... Eastern North Pacific. 2 0 10 0
Minke whale......................... Alaska................ 0 0 0 0
California, Oregon, & 18 0 90 0
Washington.
Gray whale.......................... Eastern North Pacific. 11 0 55 0
Western North Pacific. 0 0 0 0
Sperm whale......................... North Pacific......... 0 0 0 0
California, Oregon, & 78 0 390 0
Washington.
Kogia (spp.)........................ California, Oregon, & 106 1 530 5
Washington.
Killer Whale........................ Alaska Resident....... 2 0 10 0
Northern Resident..... 0 0 0 0
West Coast Transient.. 202 0 1,010 0
East N. Pacific 22 0 110 0
Offshore.
East N. Pacific 0 0 0 0
Southern Resident.
Short-finned pilot whale............ California, Oregon, & 0 0 0 0
Washington.
Short-beaked common dolphin......... California, Oregon, & 1,628 0 8,140 0
Washington.
Bottlenose dolphin.................. California, Oregon, & 0 0 0 0
Washington.
Striped dolphin..................... California, Oregon, & 14 0 70 0
Washington.
Pacific white-sided dolphin......... North Pacific......... 3 0 15 0
California, Oregon, & 4,869 0 24,345 0
Washington.
Northern right whale dolphin........ California, Oregon, & 2,038 0 10,190 0
Washington.
Risso's dolphin..................... California, Oregon, & 1,154 0 5,770 0
Washington.
Harbor porpoise..................... Southeast Alaska...... 926 0 4,630 0
Northern OR/WA Coast.. 17,212 15 86,060 75
Northern CA/Southern 25,819 23 129,095 115
OR.
WA Inland Waters...... 5,336 6 26,680 30
Dall's porpoise..................... Alaska................ 1,200 0 6,000 0
California, Oregon, & 10,139 43 50,695 215
Washington.
Cuvier's beaked whale............... Alaska................ 15 0 75 0
California, Oregon, & 91 0 455 0
Washington.
Baird's beaked whale................ Alaska................ 25 0 125 0

[[Page 31797]]

California, Oregon, & 149 0 745 0
Washington.
Mesoplodon beaked whales............ California, Oregon, & 369 0 1,845 0
Washington.
Steller sea lion.................... Eastern U.S........... 504 0 2,520 0
Guadalupe fur seal.................. San Miguel Island..... 3 0 15 0
California sea lion................. U.S. Stock............ 2,073 0 10,365 0
Northern fur seal................... Eastern Pacific....... 1,830 0 9,150 0
California............ 27 0 135 0
Northern elephant seal.............. California Breeding... 1,325 2 6625 10
Harbor seal......................... Southeast Alaska 22 0 110 0
(Clarence Strait).
OR/WA Coast........... 1,655 4 8,275 20
California............ 0 0 0 0
WA Northern Inland 1,448 14 7,240 70
Waters.
Southern Puget Sound.. 196 1 980 5
Hood Canal............ 59,217 67 296,085 335
----------------------------------------------------------------------------------------------------------------

Vessel Strike

There has never been a vessel strike to marine mammals during any
testing activities in the Study Area. A detailed analysis of strike
data is contained in Section 6.7 (Estimated Take of Large Whales by
Navy Vessel Strike) of the LOA application. Testing activities
involving vessel movement could mainly occur in the Inland Waters and
in Western Behm Canal with some additional testing activities in the
offshore region. The majority of vessels used in the Inland Waters and
Western Behm Canal are smaller vessels, which are less likely to be
involved in a whale strike. The Navy's proposed actions would not
result in any appreciable changes in locations or frequency of vessel
activity, and there have been no whale strikes during any previous
testing activities in the Study Area. The manner in which the Navy has
tested would remain consistent with the range of variability observed
over the last decade so the Navy does not anticipate vessel strikes
would occur within the Study Area during testing events. Further, takes
by injury or mortality resulting from vessel strike were not predicted
in the Navy's analysis. As such, NMFS is not authorizing take by injury
or mortality resulting from vessel strike this proposed rule. However,
the Navy has proposed measures (see Proposed Mitigation) to mitigate
potential impacts to marine mammals from vessel strikes during testing
activities in the Study Area.

Analysis and Negligible Impact Determination

Negligible impact is ``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'' (50 CFR 216.103). 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 takes, alone, is not
enough information on which to base an impact determination, as the
severity of harassment may vary greatly depending on the context and
duration of the behavioral response, many of which would not be
expected to have deleterious impacts on the fitness of any individuals.
In determining whether the expected takes will have a negligible
impact, in addition to considering estimates of the number of marine
mammals that might be ``taken'', 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 (e.g.,
severity) of estimated Level A harassment takes, the number of
estimated mortalities, and the status of the species.
The Navy's specified activities have been described based on best
estimates of the maximum amount of sonar and other acoustic source use
or detonations that the Navy would conduct. There may be some
flexibility in that the exact number of hours, items, or detonations
may vary from year to year, but take totals are not authorized to
exceed the 5-year totals indicated in Tables 17-21. However, it is also
worth noting here that while models that incorporate realistic
environmental, operational, and biological parameters are the best way
to satisfy our need to quantify takes, and are very useful in our
analysis (especially where subsets of takes can be pared with factors
associated with differential expected levels of severity or duration),
due to the inherent variability and uncertainty in model inputs,
modeled take estimates are never expected to represent the exact number
of animals that will actually be taken, but rather can provide
(depending on nature of model) a decent relative understanding of the
portion of a population that might be affected and/or the number of
repeat takes of individuals on subsequent days that might occur.
The Navy's take request is based on their model and post-model
analysis. 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 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 above the Level B harassment threshold) that would
occur. Additionally, these instances may represent either a very brief
exposure (seconds) or, in some cases, longer durations of exposure
within a day. Depending on the location, duration, and frequency of
activities, along with the distribution and movement of marine mammals,
individual animals may be exposed to impulse or non-impulse sounds at
or above the Level B harassment threshold on multiple days. However,
the Navy is currently unable to estimate the number of individuals that
may be taken during training and testing activities. The model results
estimate the total number of takes that may occur to a smaller number
of

[[Page 31798]]

individuals. While the model shows that an increased number of
exposures may take place due to an increase in events/activities and
ordnance, the types and severity of individual responses to training
and testing activities are not expected to change.
It is important to note that, while NMFS does not expect that all
of the requested and authorized takes (as shown in Tables 17-21 and
based on the acoustic analysis) will actually occur, we nevertheless
base our analysis and NID on the maximum number of takes requested and
authorized (i.e., not on a lower number of takes anticipated).

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 Level B harassment 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 22) 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
illustrated below, the majority (about 73 percent, at least for hull-
mounted sonar, which is responsible for most of the sonar takes) of
calculated takes from 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.
Specifically, given a range of behavioral responses that may be
classified as Level B harassment, to the degree that higher received
levels are expected to result in more severe behavioral responses, only
a small percentage of the anticipated Level B harassment from Navy
activities might necessarily be expected to potentially result in more
severe responses, especially when the distance from the source at which
the levels below are received is considered (see Table 22). Marine
mammals are able to discern the distance of a given sound source, and
given other equal factors (including received level), they have been
reported to respond more to sounds that are closer (DeRuiter et al.,
2013). Further, the estimated number of responses do not reflect either
the duration or context of those anticipated responses, some of which
will be of very short duration, and other factors should be considered
when predicting how the estimated takes may affect individual fitness.

Table 22--Non-Impulsive Ranges in 6-dB Bins and Percentage of Behavioral Harassments
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sonar Bin MF1 (e.g., SQS-53; ASW Sonar Bin MF4 (e.g., AQS-22; ASW Sonar Bin MF5 (e.g., SSQ-62; ASW
Hull Mounted Sonar) Dipping Sonar) Sonobuoy)
--------------------------------------------------------------------------------------------------------
Percentage of Percentage of Percentage of
Received Level Distance at which behavioral Distance at which behavioral Distance at which behavioral
levels occur harassments levels occur harassments levels occur harassments
within radius of occurring at within radius of occurring at within radius of occurring at
source (m) given levels source (m) given levels source (m) given levels
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low Frequency Cetaceans
120 <=SPL <126................................. 178,750-156,450 0.00 100,000-92,200 0.00 22,800-15,650 0.00
126 <=SPL <132................................. 156,450-147,500 0.00 92,200-55,050 0.11 15,650-11,850 0.05
132 <=SPL <138................................. 147,500-103,700 0.21 55,050-46,550 1.08 11,850-6,950 2.84
138 <=SPL <144................................. 103,700-97,950 0.33 46,550-15,150 35.69 6,950-3,600 16.04
144 <=SPL <150................................. 97,950-55,050 13.73 15,150-5,900 26.40 3,600-1,700 33.63
150 <=SPL <156................................. 55,050-49,900 5.28 5,900-2,700 17.43 1,700-250 44.12
156 <=SPL <162................................. 49,900-10,700 72.62 2,700-1,500 9.99 250-100 2.56
162 <=SPL <168................................. 10,700-4,200 6.13 1,500-200 9.07 100-<50 0.76
168 <=SPL <174................................. 4,200-1,850 1.32 200-100 0.18 <50 0.00
174 <=SPL <180................................. 1,850-850 0.30 100-<50 0.05 <50 0.00
180 <=SPL <186................................. 850-400 0.07 <50 0.00 <50 0.00
186 <=SPL <192................................. 400-200 0.01 <50 0.00 <50 0.00
192 <=SPL <198................................. 200-100 0.00 <50 0.00 <50 0.00
Mid Frequency Cetaceans
120 <=SPL <126................................. 179,400-156,450 0.00 100,000-92,200 0.00 23,413-16,125 0.00
126 <=SPL <132................................. 156,450-147,500 0.00 92,200-55,050 0.11 16,125-11,500 0.06
132 <=SPL <138................................. 147,500-103,750 0.21 55,050-46,550 1.08 11,500-6,738 2.56
138 <=SPL <144................................. 103,750-97,950 0.33 46,550-15,150 35.69 6,738-3,825 13.35
144 <=SPL <150................................. 97,950-55,900 13.36 15,150-5,900 26.40 3,825-1,713 37.37
150 <=SPL <156................................. 55,900-49,900 6.12 5,900-2,700 17.43 1,713-250 42.85
156 <=SPL <162................................. 49,900-11,450 71.18 2,700-1,500 9.99 250-150 1.87
162 <=SPL <168................................. 11,450-4,350 7.01 1,500-200 9.07 150-<50 1.93
168 <=SPL <174................................. 4,350-1,850 1.42 200-100 0.18 <50 0.00
174 <=SPL <180................................. 1,850-850 0.29 100-<50 0.05 <50 0.00
180 <=SPL <186................................. 850-400 0.07 <50 0.00 <50 0.00
186 <=SPL <192................................. 400-200 0.01 <50 0.00 <50 0.00
192 <=SPL <198................................. 200-100 0.00 <50 0.00 <50 0.00
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes: (1) ASW = anti-submarine warfare, m = meters, SPL = sound pressure level; (2) Odontocete behavioral response function is also used for high-
frequency cetaceans, phocid seals, otariid seals and sea lions, and sea otters.

[[Page 31799]]

Although the Navy has been monitoring 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 growing. The Navy has submitted
reports from more than 60 major exercises across Navy range complexes
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 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). Note that there is a difference
between multiple-day substantive behavioral reactions and multiple-day
anthropogenic activities. For example, just because at-sea exercises
last for multiple days does not necessarily mean that individual
animals are either exposed to those exercises for multiple days or,
further, exposed in a manner resulting in a sustained multiple day
substantive behavioral response. Large multi-day Navy exercises
typically include assets that travel at high speeds (typically 10-15
knots, or higher) and likely cover large areas that are relatively far
from shore, in addition to the fact that marine mammals are moving as
well, 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. Additionally, the Navy does not necessarily operate active
sonar the entire time during an exercise. While it is certainly
possible that these sorts of exercises could overlap with individual
marine mammals multiple days in a row at levels above those anticipated
to result in a take, because of the factors mentioned above, it is
considered not to be likely for the majority of takes, does not mean
that a behavioral response is necessarily sustained for multiple days,
and still necessitates the consideration of likely duration and context
to assess any effects on the individual's fitness.
Durations for non-impulsive activities utilizing tactical sonar
sources vary and are fully described in Appendix A of the January 2014
DEIS/OEIS. ASW training and testing exercises using MFAS/HFAS generally
last for 2-16 hours, and may have intervals of non-activity in between.
Because of the need to train in a large variety of situations, the Navy
does not typically conduct successive MTEs or other ASW exercises in
the same locations. Given the average length of ASW exercises (times of
continuous sonar use) and typical vessel speed, combined with the fact
that the majority of the cetaceans in the Study Area would not likely
remain in an area for successive days, it is unlikely that an animal
would be exposed to MFAS/HFAS at levels likely to result in a
substantive response that would then be carried on for more than one
day or on successive days. There are no MTEs proposed for NWTT
activities.
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 \1/2\ 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, which would inform how TTS might specifically
interfere with communications with conspecifics, was provided in the
LOA application.
2. Degree of the shift (i.e., by how many dB the sensitivity of the
hearing is reduced)--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), although 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

[[Page 31800]]

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 or other critical auditory cues. If impaired,
marine mammals would typically be aware of their impairment and are
sometimes able to 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, communication series, or other
critical auditory cue, 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.

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, depending 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. A combination of these
environmental and operational parameters is not present in the NWTT
action. When this is combined with consideration of the number of hours
of active sonar training that will be conducted and the nature of the
exercises--which do not typically include the use of multiple hull-
mounted sonar sources--we believe that the probability is small that
this will occur. Furthermore, given that there has never been a
stranding in the Study Area associated with sonar use and based on the
number of occurrences where strandings have been definitively
associated with military 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 as a result of the Navy's
proposed training and testing activities. 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.
As stated previously, there have been no recorded Navy vessel
strikes of any marine mammals during training or testing in the NWTT
Study Area to date, nor were takes by injury or mortality resulting
from vessel strike predicted in the Navy's acoustic effects analysis.

Species/Group 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, sei
whales, gray whales). The quantitative analysis consists of computer
modeled estimates and a post-model analysis (which considers the
potential for avoidance and highly effective mitigation to prevent
Level A harassments) to determine the number of potential 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

[[Page 31801]]

further analyzed and adjusted to consider animal avoidance and
implementation of mitigation measures, resulting in final estimates of
effects due to Navy training and testing.
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). 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 injurious sound exposures,
thus, reducing Level A takes. All adjusted effects resulting from
likely avoidance behaviors and implementation of highly effective
mitigation are quantified (added) as Level B harassment (TTS) and are
part of the requested annual effects to marine mammals.
It is important to note that adjustments to take estimates as a
result of implemented mitigation were only applied to those events
having a very high likelihood of detecting marine mammals. It is also
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. NMFS
provided input to the Navy on this process and the Navy's qualitative
analysis is described in detail in Chapter 6 of their LOA application.
(http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm).
Predicted harassment of marine mammals from sonar and other active
acoustic sources and explosions during annual training and testing
activities are shown in Tables 18-21. The acoustic analysis predicts
the majority of marine mammal species in the Study Area would not be
exposed to explosive (impulse) sources associated with training and
testing activities, which would exceed the current impact thresholds
(Table 4). Only harbor porpoise, Dall's porpoise, and Northern elephant
seal are predicted to have exposures that would exceed the current
impact thresholds for explosives, as presented in the following
subsections.
The analysis below may in some cases (e.g., mysticetes, porpoises,
pinnipeds) address species collectively if they occupy the same
functional hearing group (i.e., low, mid, and high-frequency cetaceans
and pinnipeds in water), have similar hearing capabilities, and/or are
known to generally behaviorally respond similarly to acoustic
stressors. Where there are meaningful differences between species in
anticipated individual responses to activities, impact of expected take
on the population due to differences in population status, or impacts
on habitat, they will either be described within the section or the
species will be included as a separate sub-section. See the Brief
Background on Sound section earlier in this proposed rule for a
description of marine mammal functional hearing groups as originally
designated by Southall et al. (2007).
Mysticetes--The Navy's acoustic analysis predicts that 184
instances of Level B harassment of mysticete whales may occur in the
Study Area each year from sonar and other active acoustic stressors
during training and testing activities. Species-specific Level B take
estimates are as follows: 57 humpback whales (Central North Pacific and
California/Oregon/Washington stocks); 11 blue whales (Eastern North
Pacific stock); 61 fin whales (Northeast Pacific and California/Oregon/
Washington stocks); 2 sei whales (Eastern North Pacific stock); 36
minke whales (Alaska and California/Oregon/Washington stocks); and 17
gray whales (Eastern North Pacific and Western North Pacific stocks).
Based on the distribution information presented in the LOA application,
it is highly unlikely that North Pacific right whales would be
encountered in the Study Area during events involving use of sonar and
other active acoustic sources. The acoustic analysis did not predict
any takes of North Pacific right whales, and NMFS is not authorizing
any takes of this species. Of these species, humpback (This species is
being considered by NMFS for removal or down-listing from the U.S.
Endangered Species List [NMFS, 2009, 2013a; Bettridge et al. 2015;
NOAA, 2015b]), blue, fin, and sei whales are listed as endangered under
the ESA and depleted under the MMPA.
These exposure estimates represent a limited number of takes
relative to population estimates for all mysticete stocks in the Study
Area (Table 9). When the numbers of behavioral takes are compared to
the estimated stock abundance and if one assumes that each take happens
to a separate animal, less than 20 percent of each of these stocks
would be behaviorally harassed during the course of a year. More
likely, fewer individuals would be taken, but a subset would be taken
more than one time per year.
Level B harassment takes are anticipated to be in the form of TTS
and behavioral reactions and no injurious takes of humpback, blue, fin,
or sei whales from sonar and other active acoustic stressors or
explosives 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 sonar. Most Level B harassments to mysticetes
from sonar would result from received levels less than 158 dB SPL.
Recovery from a threshold shift (TTS) can take a few minutes to a few
days (i.e., there is recovery), depending on the severity of the
initial shift; however, NMFS does not anticipate TTS of a long duration
or severe degree to occur as a result of exposure to MFAS/HFAS in the
Study Area. Threshold shifts do not necessarily affect all hearing
frequencies equally, so some threshold shifts may not interfere with an
animal's of biologically relevant sounds. Most low-frequency
(mysticetes) cetaceans observed in studies usually avoided sound
sources at levels of less than or equal to 160 dB re 1[mu]Pa.
Mysticetes that are exposed to sonar and other active acoustic sources
may react by alerting, ignoring the stimulus, changing their behaviors
or vocalizations, or avoiding the area by swimming away or diving
(Richardson, 1995; Nowacek, 2007; Southall et al., 2007).
Specific to U.S. Navy systems using low frequency sound, studies
were undertaken in 1997-98 pursuant to the Navy's Low Frequency Sound
Scientific Research Program. These studies found only short-term
responses to low frequency sound by mysticetes (fin, blue, and
humpback), including changes in vocal activity and avoidance of the
source vessel (Clark, 2001; Miller et al., 2000; Croll et al., 2001;
Fristrup et al., 2003; Nowacek et al., 2007). Baleen whales exposed to
moderate low-frequency signals demonstrated no variation in foraging
activity (Croll et al., 2001). Low-frequency signals of the

[[Page 31802]]

Acoustic Thermometry of Ocean Climate sound source were not found to
affect dive times of humpback whales in Hawaiian waters (Frankel and
Clark, 2000).
Specific to mid-frequency sounds, studies by Melc[oacute]n et al.
(2012) in the Southern California Bight found that the likelihood of
blue whale low-frequency calling (usually associated with feeding
behavior) decreased with an increased level of mid-frequency sonar,
beginning at a SPL of approximately 110-120 dB re 1 [mu]Pa. However, it
is not known whether the lower rates of calling actually indicated a
reduction in feeding behavior or social contact since the study used
data from remotely deployed, passive acoustic monitoring buoys.
Preliminary results from the 2010-2011 field season of an ongoing
behavioral response study in Southern California waters indicated that
in some cases and at low received levels, tagged blue whales responded
to mid-frequency sonar but that those responses were mild and there was
a quick return to their baseline activity (Southall et al., 2012b).
Blue whales responded to a mid-frequency sound source, with a source
level between 160 and 210 dB re 1 [mu]Pa at 1 m and a received sound
level up to 160 dB re 1 [mu]Pa, by exhibiting generalized avoidance
responses and changes to dive behavior during controlled exposure
experiments (CEE) (Goldbogen et al., 2013). However, reactions were not
consistent across individuals based on received sound levels alone, and
likely were the result of a complex interaction between sound exposure
factors such as proximity to sound source and sound type (mid-frequency
sonar simulation vs. pseudo-random noise), environmental conditions,
and behavioral state. Surface feeding whales did not show a change in
behavior during CEEs, but deep feeding and non-feeding whales showed
temporary reactions that quickly abated after sound exposure. Distances
of the sound source from the whales during CEEs were sometimes less
than a mile. Furthermore, the more dramatic reactions reported by
Goldbogen et al. (2013) were from non-sonar like signals, a
pseudorandom noise that could likely have been a novel signal to blue
whales. The preliminary findings from Goldbogen et al. (2013) and
Melc[oacute]n et al. (2012) are consistent with the Navy's criteria and
thresholds for predicting behavioral effects to mysticetes from sonar
and other active acoustic sources used in the quantitative acoustic
effects analysis for NWTT. The behavioral response function predicts a
probability of a substantive behavioral reaction for individuals
exposed to a received SPL of 120 dB re 1 [mu]Pa or greater, with an
increasing probability of reaction with increased received level as
demonstrated in Melc[oacute]n et al. (2012).
High-frequency systems are not within mysticetes' ideal hearing
range and it is unlikely that they would cause a significant behavioral
reaction resulting in takes.
Overall, the number of predicted behavioral reactions is low and
occasional behavioral reactions are unlikely to cause long-term
consequences for individual animals or populations. 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, there is no designated critical
habitat for mysticetes in the NWTT Study Area. There are also no known
specific breeding or calving areas for mysticete species within the
Study Area. Some biologically-important mysticete feeding and migration
areas (Northern Puget Sound Feeding Area for gray whales; Northbound
Migration Phase A for gray whales; Northbound Migration Phase B for
gray whales; Potential Presence Migration Area for gray whales;
Northern Washington Feeding Area for humpback whales; Stonewall and
Heceta Bank Feeding Area for humpback whales; Cape Blanco and Orford
Reef Feeding Area for gray whale; and Point St. George Feeding Area for
gray whales) may overlap slightly with the Study Area. However, a
review of the BIAs for humpback whales and gray whales against areas
where most acoustic activities are conducted in the Study Area
(especially those that involve ASW hull-mounted sonar, sonobuoys, and
use of explosive munitions) identified that there is no spatial
overlap. The overall risk to species in these areas has been
preliminarily determined to be low or biologically insignificant, in
part due to the generally infrequent, temporally and spatially
variable, and extreme offshore nature of sonar-related activities and
sound propagation relative to the more coastally distributed
biologically important areas; the probability that propagated receive
levels within these areas would be relatively low in terms of
behavioral criteria (Debich et al., 2014; U.S. Department of the Navy,
2013d); the likelihood of TTS or PTS sound levels being extremely low;
and the overall application of Navy mitigation procedures for marine
mammals sighted within prescribed mitigation zones if such activities
were to occur in or near these areas. If additional biologically
important areas are identified by NMFS after finalization of this rule
and the Navy's NWTT EIS/OEIS, the Navy and NMFS will use the Adaptive
Management process to assess whether any additional mitigation should
be considered in those areas. Consequently, the NWTT activities are not
expected to adversely impact annual rates of recruitment or survival of
mysticete whales.
There has never been a vessel strike to a whale during any active
training or testing activities in the Study Area. A detailed analysis
of strike data is contained in Chapter 6 (Section 6.7, Estimated Take
of Large Whales by Navy Vessel Strike) of the LOA application. The Navy
and NMFS do not anticipate vessel strikes to any marine mammals during
training or testing activities within the Study Area, nor were takes by
injury or mortality resulting from vessel strike predicted in the
Navy's analysis. Therefore, NMFS is not authorizing mysticete takes (by
injury or mortality) from vessel strikes during the 5-year period of
the NWTT regulations.
Sperm Whales--The Navy's acoustic analysis predicts that 159
instances of Level B harassment of sperm whales (California/Oregon/
Washington stock) may occur in the Study Area each year from sonar or
other active acoustic stressors during training and testing activities.
These Level B takes are anticipated to be in the form of TTS and
behavioral reactions and no injurious takes of sperm whales from sonar
and 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 (Richardson,
1995; Nowacek, 2007; Southall et al., 2007). 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. Recovery
from a threshold shift (TTS) can take a few minutes to a few days,
depending on the exposure duration, sound exposure level, and the
magnitude of the initial shift, with

[[Page 31803]]

larger threshold shifts and longer exposure durations requiring longer
recovery times (Finneran et al., 2005; Mooney et al., 2009a; Mooney et
al., 2009b; Finneran and Schlundt, 2010). Large threshold shifts are
not anticipated for these activities because of the unlikelihood that
animals will remain within the ensonified area (due to the short
duration of the majority of exercises, the speed of the vessels, and
the short distance within which the animal would need to approach the
sound source) at high levels for the duration necessary to induce
larger threshold shifts. Threshold shifts do not necessarily affect all
hearing frequencies equally, so some threshold shifts may not interfere
with an animal's hearing of biologically relevant sounds. No sperm
whales are predicted to be exposed to MFAS/HFAS sound levels associated
with PTS or injury.
The majority of Level B takes are expected to be in the form of
mild responses. Relative to the population size (stock abundance
estimates are shown in Table 9), this activity is anticipated to result
only in a limited number of Level B harassment takes. When the number
of behavioral takes is compared to the estimated stock abundance and if
one assumes that each take happens to a separate animal, less than 17
percent of the California/Oregon/Washington stock would be behaviorally
harassed during the course of a year. More likely, fewer individuals
would be taken, but a subset would be taken more than one time per
year. Overall, the number of predicted behavioral reactions are
unlikely to cause long-term consequences for individual animals or
populations. The NWTT activities are not expected to occur in an area/
time of specific importance for reproductive, feeding, or other known
critical behaviors for sperm whales. Consequently, the activities are
not expected to adversely impact annual rates of recruitment or
survival of sperm whales. Sperm whales are listed as depleted under the
MMPA and endangered under the ESA; however, there is no designated
critical habitat in the Study Area.
There has never been a vessel strike to a sperm whale during any
active training or testing activities in the Study Area. A detailed
analysis of strike data is contained in Chapter 6 (Section 6.7,
Estimated Take of Large Whales by Navy Vessel Strike) of the LOA
application. The Navy and NMFS do not anticipate vessel strikes to any
marine mammals during training or testing activities within the Study
Area, nor were takes by injury or mortality resulting from vessel
strikes predicted in the Navy's analysis. Therefore, NMFS is not
authorizing sperm whale takes (by injury or mortality) from vessel
strikes during the 5-year period of the NWTT regulations.
Porpoises--The Navy's acoustic analysis predicts that 15,071
instances of Level B harassment of Dall's porpoises (Alaska and
California/Oregon/Washington stocks) and 138,225 instances of Level B
harassment of harbor porpoises (Southeast Alaska, Northern Oregon/
Washington Coast, Northern California/Southern Oregon, and Washington
Inland Waters stocks) (mainly behavioral reaction) may occur each year
from sonar and other active acoustic stressors and explosives
associated with training and testing activities in the Study Area.
These estimates represent the total number of exposures and not
necessarily the number of individuals exposed, as a single individual
may be exposed multiple times over the course of a year. Behavioral
responses can range from a mild orienting response, or a shifting of
attention, to flight and panic (Richardson, 1995; Nowacek, 2007;
Southall et al., 2007).
Acoustic analysis (factoring in the post-model correction for
avoidance and mitigation) also predicted that 47 Dall's porpoises and
45 harbor porpoises might be exposed to sound levels likely to result
in PTS or injury (Level A harassment) from mainly sonar and other
active acoustic stressors, and explosives. In the case of all explosive
exercises, it is worth noting that the amount of explosive and acoustic
energy entering the water, and therefore the effects on marine mammals,
may be overestimated, as many explosions actually occur upon impact
with above-water targets. However, sources such as these were modeled
as exploding at 1-meter depth. Furthermore, in the case of all
explosive exercises, the exclusion zones are considerably larger than
the estimated distance at which an animal would be exposed to injurious
sounds or pressure waves.
Animals that do experience hearing loss (TTS or PTS) may have
reduced ability to detect relevant sounds such as predators, prey, or
social vocalizations. Some porpoise vocalizations might overlap with
the MFAS/HFAS TTS frequency range (2-20 kHz). It is worth noting that
TTS in the range induced by MFAS/HFAS would reduce sensitivity in the
band that killer whales (a potential predator) click and echolocate in.
Recovery from a threshold shift (TTS; partial hearing loss) can take a
few minutes to a few days, depending on the exposure duration, sound
exposure level, and the magnitude of the initial shift, with larger
threshold shifts and longer exposure durations requiring longer
recovery times (Finneran et al., 2005; Mooney et al., 2009a; Mooney et
al., 2009b; Finneran and Schlundt, 2010). More severe shifts may not
fully recover and thus would be considered PTS. However, large degrees
of PTS are not anticipated for these activities because of the
unlikelihood that animals will remain within the ensonified area (due
to the short duration of the majority of exercises, the speed of the
vessels, and the short distance within which the animal would need to
approach the sound source) at high levels for the duration necessary to
induce larger threshold shifts. Threshold shifts do not necessarily
affect all hearing frequencies equally, so some threshold shifts may
not interfere with an animal hearing biologically relevant sounds. The
likely consequences to the health of an individual that incurs PTS can
range from mild to more serious, depending 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. Furthermore,
likely avoidance of intense activity and sound coupled with mitigation
measures would further reduce the potential for severe PTS exposures to
occur. 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.
Harbor porpoises have been observed to be especially sensitive to
human activity (Tyack et al., 2011; Pirotta et al., 2012). The
information currently available regarding harbor porpoises suggests a
very low threshold level of response for both captive (Kastelein et
al., 2000; Kastelein et al., 2005) and wild (Johnston, 2002) animals.
Southall et al. (2007) concluded that harbor porpoises are likely
sensitive to a wide range of anthropogenic sounds at low received
levels (~90 to 120 dB). Research and observations of harbor porpoises
for other locations show that this small species is wary of human
activity and will display profound avoidance behavior for anthropogenic
sound sources in many situations at levels down to 120 dB re 1 [mu]Pa
(Southall, 2007). Harbor porpoises routinely avoid and swim away from
large motorized vessels (Barlow et al., 1988; Evans et al., 1994; Palka
and Hammond, 2001; Polacheck and

[[Page 31804]]

Thorpe, 1990). The vaquita, which is closely related to the harbor
porpoise in the Study Area, appears to avoid large vessels at about
2,995 ft. (913 m) (Jaramillo-Legorreta et al., 1999). The assumption is
that the harbor porpoise would respond similarly to large Navy vessels,
possibly prior to commencement of sonar or explosive activity (i.e.,
pre-activity avoidance). Harbor porpoises may startle and temporarily
leave the immediate area of the training or testing until after the
event ends. Since a large proportion of training and testing activities
occur within harbor porpoise habitat in the Study Area and given their
very low behavioral threshold, predicted effects are more likely than
with most other odontocetes, especially at closer ranges (within a few
kilometers). Since this species is typically found in nearshore and
inshore habitats, resident animals that are present throughout the
Study Area could receive multiple exposures over a short period of time
year round. As mentioned earlier in the Analysis and Negligible Impact
Determination section, we anticipate more severe effects from takes
when animals are exposed to higher received levels. Animals that do not
exhibit a significant behavioral reaction would likely recover from any
incurred costs, which reduces the likelihood of long-term consequences,
such as reduced fitness, for the individual or population.
Stock abundance estimates for Dall's and harbor porpoises are shown
in Table 9. When the numbers of takes for Dall's porpoise are compared
to the estimated stock abundances and if one assumes that each take
happens to a separate animal, approximately 30 percent of the Alaska
stock and less than 2 percent of the California/Oregon/Washington stock
would be harassed (behaviorally) during the course of a year. More
likely, fewer individuals are harassed, but a subset are harassed more
than one time during the course of the year. The number of harbor
porpoises--in particular, Northern Oregon/Washington Coast and Northern
California/Southern Oregon stocks--behaviorally harassed by exposure to
MFAS/HFAS in the Study Area is higher than the other species (and, in
fact, suggests that every member of the stock could potentially be
taken by Level B harassment multiple times, although it is more likely
that fewer individuals are harassed but a subset are harassed more than
one time during the course of the year) because of the low Level B
harassment threshold (we assume for the purpose of estimating take that
all harbor porpoises exposed to 120 dB or higher MFAS/HFAS will be
taken by Level B behavioral harassment), which essentially makes the
ensonified area of effects significantly larger than for the other
species. However, the fact that the threshold is a step function and
not a curve (and assuming uniform density) means that the vast majority
of the takes occur in the very lowest levels that exceed the threshold
(it is estimated that approximately 80 percent of the takes are from
exposures to 120 dB to 126 dB), which means that anticipated behavioral
effects are not expected to be severe (e.g., temporary 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 an animal. ASW training and testing
exercises using MFAS/HFAS generally last for 2-16 hours, and may have
intervals of non-activity in between. In addition, the Navy does not
typically conduct successive MTEs (no MTEs are proposed for NWTT) or
other ASW exercises in the same locations. Given the average length of
ASW exercises (times of continuous sonar use) and typical vessel speed,
combined with the fact that the majority of the harbor porpoises in the
Study Area would not likely remain in an area for successive days, it
is unlikely that an animal would be exposed to MFAS/HFAS at levels
likely to result in a substantive response (e.g., interruption of
feeding) that would then be carried on for more than one day or on
successive days. Thompson et al. (2013) showed that seismic surveys
conducted over a 10-day period in the North Sea did not result in the
broad-scale displacement of harbor porpoises away from preferred
habitat. The harbor porpoises were observed to leave the area at the
onset of survey, but returned within a few hours, and the overall
response of the porpoises decreased over the 10-day period.
The harbor porpoise is a common species in the nearshore coastal
waters of the Study Area year-round (Barlow, 1988; Green et al., 1992;
Osmek et al., 1996, 1998; Forney and Barlow, 1998; Carretta et al.,
2009). Since 1999, Puget Sound Ambient Monitoring Program data and
stranding data documented increasing numbers of harbor porpoise in
Puget Sound, indicating that the species may be returning to the area
(Nysewander, 2008; Washington Department of Fish and Wildlife, 2008;
Jeffries, 2013a). Sightings in northern Hood Canal (north of the Hood
Canal Bridge) have increased in recent years (Calambokidis, 2010).
Harbor porpoise continue to inhabit the waters of Hood Canal (including
Dabob Bay), which has for decades served as the location for training
and testing events using sonar and other active acoustic sources.
Considering the information above, the predicted effects to Dall's
and harbor porpoises are unlikely to cause long-term consequences for
individual animals or the population. The NWTT activities are not
expected to occur in an area/time of specific importance for
reproductive, feeding, or other known critical behaviors for Dall's and
harbor porpoises. Pacific stocks of Dall's and harbor porpoises are not
listed as depleted under the MMPA. Consequently, the activities are not
expected to adversely impact annual rates of recruitment or survival of
porpoises.
Pygmy and Dwarf Sperm Whales (Kogia spp.)--Due to the difficulty in
differentiating these two species at sea, an estimate of the effects on
the two species have been combined. The Navy's acoustic analysis
predicts that 179 instances of Level B harassment (TTS and behavioral
reaction) of the California/Oregon/Washington stock of Kogia spp. may
occur each year from sonar and other active acoustic stressors
associated with training and testing activities in the Study Area. The
Navy's acoustics analysis (factoring in the post-model correction for
avoidance and mitigation) also indicates that 1 exposure of Kogia to
sound levels from non-impulsive acoustic sources likely to result in
level A harassment (PTS) may occur during testing activities in the
Study Area. Stock abundance estimates for California/Oregon/Washington
stocks of Kogia spp. are shown in Table 9. Relative to population size
these represent only a limited number of takes if one assumes that each
take happens to a separate animal. More likely, fewer individuals would
be taken, but a subset would be taken more than one time per year.
Recovery from a threshold shift (TTS; partial hearing loss) can
take a few minutes to a few days, depending on the exposure duration,
sound exposure level, and the magnitude of the initial shift, with
larger threshold shifts and longer exposure durations requiring longer
recovery times (Finneran et al., 2005; Mooney et al., 2009a; Mooney et
al., 2009b; Finneran and Schlundt, 2010). PTS would not fully recover.
However, large degrees of PTS are not anticipated for these activities
because of the unlikelihood that animals will remain within the
ensonified area (due to the short duration of the majority of
exercises, the speed of the vessels, and the short distance within
which the

[[Page 31805]]

animal would need to approach the sound source) at high levels for the
duration necessary to induce larger threshold shifts. Threshold shifts
do not necessarily affect all hearing frequencies equally, so some
threshold shifts may not interfere with an animal hearing biologically
relevant sounds. The likely consequences to the health of an individual
that incurs PTS can range from mild to more serious, depending 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. Furthermore, likely avoidance of intense activity and sound
coupled with mitigation measures would further reduce the potential for
severe PTS exposures to occur. 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.
Some Kogia spp. vocalizations might overlap with the MFAS/HFAS TTS
frequency range (2-20 kHz), but the limited information for Kogia spp.
indicates that their clicks are at a much higher frequency and that
their maximum hearing sensitivity is between 90 and 150 kHz. It is
worth noting that TTS in the range induced by MFAS would reduce
sensitivity in the band that killer whales (a potential predator) click
and echolocate in. However, as noted previously, NMFS does not
anticipate TTS of a long duration or severe degree to occur as a result
of exposure to MFA/HFAS.
Research and observations on Kogia spp. are limited. These species
tend to avoid human activity and presumably anthropogenic sounds. Pygmy
and dwarf sperm whales may startle and leave the immediate area of
activity, reducing potential impacts. Pygmy and dwarf sperm whales have
been observed to react negatively to survey vessels or low altitude
aircraft by quick diving and other avoidance maneuvers, and none were
observed to approach vessels (Wursig et al., 1998). Based on their
tendency to avoid acoustic stressors (e.g., quick diving and other
vertical avoidance maneuvers) coupled with the short duration and
intermittent nature (e.g., sonar pings during ASW activities occur
about every 50 seconds) of the majority of training and testing
exercises and the speed of the Navy vessels involved, 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).
The predicted effects to Kogia spp. are expected to be temporary
and unlikely to cause long-term consequences for individual animals or
populations. The NWTT activities are not expected to occur in an area/
time of specific importance for reproductive, feeding, or other known
critical behaviors. Pacific stocks of Kogia are not depleted under the
MMPA. Consequently, the activities are not expected to adversely impact
annual rates of recruitment or survival of pygmy and dwarf sperm
whales.
Beaked Whales--The Navy's acoustic analysis predicts that the
following numbers of Level B harassment of beaked whales may occur
annually from sonar and other active acoustic stressors associated with
training and testing activities in the Study Area: 665 Baird's beaked
whales (California/Oregon/Washington and Alaska stocks), 459 Cuvier's
beaked whales (California/Oregon/Washington and Alaska stocks), and
1,616 Mesoplodon beaked whales (California/Oregon/Washington stock).
These estimates represent the total number of exposures and not
necessarily the number of individuals exposed, as a single individual
may be exposed multiple times over the course of a year. These takes
are anticipated to be in the form of behavioral harassment (TTS and
behavioral reaction) and no injurious takes of beaked whales from
active acoustic stressors or explosives are requested or proposed.
Stock abundance estimates for beaked whales in the Study Area are shown
in Table 9. When the numbers of behavioral takes are compared to the
estimated stock abundances and if one assumes that each take happens to
a separate animal, less than 7 percent of the California/Oregon/
Washington stock of Cuvier's beaked whale would be behaviorally
harassed during the course of a year. Virtually all of the Baird's and
Mesoplodon beaked whale stocks (California/Oregon/Washington) would
potentially be behaviorally harassed each year, although it is more
likely that fewer individuals would be harassed but a subset would be
harassed more than one time during the course of the year. As is the
case with harbor porpoises, beaked whales have been shown to be
particularly sensitive to sound and therefore have been assigned a
lower harassment threshold based on observations of wild animals by
McCarthy et al. (2011) and Tyack et al. (2011). The fact that the Level
B harassment threshold is a step function (The Navy has adopted an
unweighted 140 dB re 1 [micro]Pa SPL threshold for significant
behavioral effects for all beaked whales) and not a curve (and assuming
uniform density) means that the vast majority of the takes occur in the
very lowest levels that exceed the threshold (it is estimated that
approximately 80 percent of the takes are from exposures to 140 dB to
146 dB), which means that the anticipated effects for the majority of
exposures are not expected to be severe (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 an animal). Further, Moretti et al. (2014) recently derived
an empirical risk function for Blainville's beaked whale that predicts
there is a 0.5 probability of disturbance at a received level of 150 dB
(CI: 144-155), suggesting that in some cases the current Navy step
function may over-estimate the effects of an activity using sonar on
beaked whales. Irrespective of the Moretti et al. (2014) risk function,
NMFS' analysis assumes that all of the beaked whale Level B takes that
are proposed for authorization will occur, and we base our negligible
impact determination, in part, on the fact that these exposures would
mainly occur at the very lowest end of the 140-dB behavioral harassment
threshold where behavioral effects are expected to be much less severe
and generally temporary in nature.
Behavioral responses can range from a mild orienting response, or a
shifting of attention, to flight and panic (Richardson, 1995; Nowacek,
2007; Southall et al., 2007). Research has also shown that beaked
whales are especially sensitive to the presence of human activity
(Tyack et al., 2011; Pirotta et al., 2012). Beaked whales have been
documented to exhibit avoidance of human activity or respond to vessel
presence (Pirotta et al., 2012). Beaked whales were observed to react
negatively to survey vessels or low altitude aircraft by quick diving
and other avoidance maneuvers, and none were observed to approach
vessels (Wursig et al., 1998). Some beaked whale vocalizations may
overlap with the MFAS/HFAS TTS frequency range (2-20 kHz); however, as
noted above, NMFS does not anticipate TTS of a serious degree or
extended duration to occur as a result of exposure to MFA/HFAS.
Recovery from a threshold shift (TTS) can take a few minutes to a few
days, depending on the exposure duration, sound exposure level, and the
magnitude of the initial shift, with larger threshold shifts and longer
exposure durations requiring longer recovery times (Finneran et al.,
2005; Mooney et al., 2009a; Mooney et al.,

[[Page 31806]]

2009b; Finneran and Schlundt, 2010). Large threshold shifts are not
anticipated for these activities because of the unlikelihood that
animals will remain within the ensonified area (due to the short
duration of the majority of exercises, the speed of the vessels, and
the short distance within which the animal would need to approach the
sound source) at high levels for the duration necessary to induce
larger threshold shifts. Threshold shifts do not necessarily affect all
hearing frequencies equally, so some threshold shifts may not interfere
with an animal's hearing of biologically relevant sounds.
It has been speculated for some time that beaked whales might have
unusual sensitivities to sonar sound due to their likelihood of
stranding in conjunction with mid-frequency sonar use. 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 re 1 [mu]Pa, or
below (McCarthy et al., 2011). Acoustic monitoring during actual sonar
exercises revealed some beaked whales continuing to forage at levels up
to 157 dB re 1 [mu]Pa (Tyack et al. 2011). Stimpert et al. (2014)
tagged a Baird's beaked whale, which was subsequently exposed to
simulated mid-frequency sonar. Changes in the animal's dive behavior
and locomotion were observed when received level reached 127 dB re 1
[mu]Pa. Manzano-Roth et al. (2013) found that for beaked whale dives
that continued to occur during MFAS activity, differences from normal
dive profiles and click rates were not detected with estimated received
levels up to 137 dB re 1 [mu]Pa while the animals were at depth during
their dives. In research done at the Navy's fixed tracking range in the
Bahamas, animals were observed to leave the immediate area of the anti-
submarine warfare training exercise (avoiding the sonar acoustic
footprint at a distance where the received level was ``around 140 dB''
SPL, according to Tyack et al. [2011]) but return within a few days
after the event ended (Claridge and Durban, 2009; Moretti et al., 2009,
2010; Tyack et al., 2010, 2011; McCarthy et al., 2011). Tyack et al.
(2011) report that, in reaction to sonar playbacks, most beaked whales
stopped echolocating, made long slow ascent to the surface, and moved
away from the sound. A similar behavioral response study conducted in
Southern California waters during the 2010-2011 field season found that
Cuvier's beaked whales exposed to MFAS displayed behavior ranging from
initial orientation changes to avoidance responses characterized by
energetic fluking and swimming away from the source (DeRuiter et al.,
2013b). However, the authors did not detect similar responses to
incidental exposure to distant naval sonar exercises at comparable
received levels, indicating that context of the exposures (e.g., source
proximity, controlled source ramp-up) may have been a significant
factor. The study itself found the results inconclusive and meriting
further investigation. Cuvier's beaked whale responses suggested
particular sensitivity to sound exposure as consistent with results for
Blainville's beaked whale. Populations of beaked whales and other
odontocetes on the Bahamas and other Navy fixed ranges that have been
operating for decades, appear to be stable. Behavioral reactions
(avoidance of the area of Navy activity) seem likely in most cases if
beaked whales are exposed to anti-submarine sonar within a few tens of
kilometers, especially for prolonged periods (a few hours or more)
since this is one of the most sensitive marine mammal groups to
anthropogenic sound of any species or group studied to date and
research indicates beaked whales will leave an area where anthropogenic
sound is present (Tyack et al., 2011; De Ruiter et al., 2013; Manzano-
Roth et al., 2013; Moretti et al., 2014). Research involving tagged
Cuvier's beaked whales in the SOCAL Range Complex reported on by
Falcone and Schorr (2012, 2014) indicates year-round prolonged use of
the Navy's training and testing area by these beaked whales and has
documented movements in excess of hundreds of kilometers by some of
those animals. Given that some of these animals may routinely move
hundreds of kilometers as part of their normal pattern, leaving an area
where sonar or other anthropogenic sound is present may have little, if
any, cost to such an animal. Photo identification studies in the SOCAL
Range Complex, a Navy range that is utilized for training and testing
more frequently than the NWTT Study Area, have identified approximately
100 individual Cuvier's beaked whale individuals with 40 percent having
been seen in one or more prior years, with re-sightings up to 7 years
apart (Falcone and Schorr, 2014). These results indicate long-term
residency by individuals in an intensively used Navy training and
testing area, which may also suggest a lack of long-term consequences
as a result of exposure to Navy training and testing activities.
Finally, results from passive acoustic monitoring estimated regional
Cuvier's beaked whale densities were higher than indicated by the
NMFS's broad scale visual surveys for the U.S. west coast (Hildebrand
and McDonald, 2009).
Based on the findings above, it is clear that the Navy's long-term
ongoing use of sonar and other active acoustic sources has not
precluded beaked whales from also continuing to inhabit those areas. In
summary, based on the best available science, the Navy and NMFS believe
that beaked whales that exhibit a significant TTS or behavioral
reaction due to sonar and other active acoustic testing activities
would generally not have long-term consequences for individuals or
populations. Claridge (2013) speculates that sonar use in a Bahamas
range could have ``a possible population-level effect'' on beaked
whales based on lower abundance in comparison to control sites.
However, the study suffers from several shortcomings and incorrectly
assumes that the Navy range and control sites were identical. The
author also acknowledged that ``information currently available cannot
provide a quantitative answer to whether frequent sonar use at [the
Bahamas range] is causing stress to resident beaked whales,'' and
cautioned that the outcome of ongoing studies ``is a critical component
to understanding if there are population-level effects.'' Moore and
Barlow (2013) have noted a decline in beaked whale populations in a
broad area of the Pacific Ocean area out to 300 nm from the coast and
extending from the Canadian-U.S. border to the tip of Baja Mexico.
There are scientific caveats and limitations to the data used for that
analysis, as well as oceanographic and species assemblage changes on
the U.S. Pacific coast not thoroughly addressed. Interestingly,
however, in the small portion of that area overlapping the Navy's SOCAL
Range Complex, long-term residency by individual Cuvier's beaked whales
and higher densities provide indications that the proposed decline
noted elsewhere is not apparent where for decades the Navy has been
intensively training and testing with sonar and other systems.
NMFS also considered New et al. (2013) and their mathematical model
simulating a functional link between foraging energetics and
requirements for survival and reproduction for 21 species of beaked
whales. However, NMFS concluded that New et al. (2013) model lacks
critical data and accurate inputs necessary to form valid conclusions
specifically about impacts of anthropogenic sound from Navy activities
on beaked whale populations. The study itself notes the need for
``future research,'' identifies ``key data

[[Page 31807]]

needs'' relating to input parameters that ``particularly affected'' the
model results, and states only that the use of the model ``in
combination with more detailed research'' could help predict the
effects of management actions on beaked whale species. In short,
information is not currently available to specifically support the use
of this model in a project-specific evaluation of the effects of navy
activities on the impacted beaked whale species in NWTT.
No beaked whales are predicted in the acoustic analysis to be
exposed to sound levels associated with PTS, other injury, or
mortality. After decades of the Navy conducting similar activities in
the NWTT Study Area without incident, NMFS does not expect strandings,
injury, or mortality of beaked whales to occur as a result of training
and testing activities. Additionally, through the MMPA process (which
allows for adaptive management), NMFS and the Navy will determine the
appropriate way to proceed in the event that a causal relationship were
to be found between Navy activities and a future stranding.
The NWTT training and testing activities are not expected to occur
in an area/time of specific importance for reproductive, feeding, or
other known critical behaviors for beaked whales. Although no areas of
specific importance for reproduction or feeding of beaked whales have
been identified in the Study Area, beaked whales are generally found in
deep waters over the continental slope, oceanic seamounts, and areas
with submarine escarpments (very seldom over the continental shelf).
None of the Pacific stocks for beaked whales species found in the Study
Area are depleted under the MMPA. Consequently, the activities are not
expected to adversely impact annual rates of recruitment or survival of
beaked whales.
Dolphins and Small Whales--The Navy's acoustic analysis predicts
the following numbers of Level B harassment of the associated species
of delphinids (dolphins and small whales, excluding killer whales) may
occur each year from sonar and other active acoustic sources during
training and testing activities in the Study Area: 2,362 short-beaked
common dolphins (California/Oregon/Washington stock); 36 striped
dolphins (California/Oregon/Washington stock); 8,354 Pacific white-
sided dolphins (California/Oregon/Washington and North Pacific stocks);
3,370 Northern right whale dolphins (California/Oregon/Washington
stock); and 1,811 Risso's dolphins (California/Oregon/Washington
stock). Based on the distribution information presented in the LOA
application, it is highly unlikely that short-finned pilot whales or
common bottlenose dolphins would be encountered in the Study Area. The
acoustic analysis did not predict any takes of short-finned pilot
whales or bottlenose dolphins and NMFS is not authorizing any takes of
these species. Relative to delphinid population sizes (stock abundance
estimates are shown in Table 9), these activities are anticipated to
generally result only in a limited number of level B harassment takes.
When the numbers of behavioral takes are compared to the estimated
stock abundance and if one assumes that each take happens to a separate
animal, less than 30 percent of the California/Oregon/Washington stock
of Risso's dolphin; less than 30 percent of the California/Oregon/
Washington stock and less than 0.02 percent of the North Pacific stock
of pacific white-sided dolphin; less than 28 percent of the California/
Oregon/Washington stock of northern right whale dolphin; less than 0.6
percent of the California/Oregon/Washington stock of short-beaked
common dolphin; and less than 0.4 percent of the California/Oregon/
Washington stock of striped dolphin would be behaviorally harassed
during the course of a year. More likely, slightly fewer individuals
are harassed, but a subset are harassed more than one time during the
course of the year.
All of these takes are anticipated to be in the form of behavioral
harassment (TTS and behavioral reaction) and no injurious takes of
delphinids from sonar and other active acoustic stressors or explosives
are requested or proposed for authorization. Further, the majority of
takes are anticipated to be by behavioral harassment in the form of
mild responses. Behavioral responses can range from a mild orienting
response, or a shifting of attention, to flight and panic (Richardson,
1995; Nowacek, 2007; Southall et al., 2007). Delphinid species
generally travel in large pods and should be visible from a distance in
order to implement mitigation measures and reduce potential impacts.
Many of the recorded delphinid vocalizations overlap with the MFAS/HFAS
TTS frequency range (2-20 kHz); however, as noted above, NMFS does not
anticipate TTS of a serious degree or extended duration to occur as a
result of exposure to MFAS/HFAS. Recovery from a threshold shift (TTS)
can take a few minutes to a few days, depending on the exposure
duration, sound exposure level, and the magnitude of the initial shift,
with larger threshold shifts and longer exposure durations requiring
longer recovery times (Finneran et al., 2005; Mooney et al., 2009a;
Mooney et al., 2009b; Finneran and Schlundt, 2010). Large threshold
shifts are not anticipated for these activities because of the
unlikelihood that animals will remain within the ensonified area (due
to the short duration of the majority of exercises, the speed of the
vessels, and the short distance within which the animal would need to
approach the sound source) at high levels for the duration necessary to
induce larger threshold shifts. Threshold shifts do not necessarily
affect all hearing frequencies equally, so some threshold shifts may
not interfere with an animal's hearing of biologically relevant sounds.
The predicted effects to delphinids are unlikely to cause long-term
consequences for individual animals or populations. The NWTT activities
are not expected to occur in an area/time of specific importance for
reproductive, feeding, or other known critical behaviors for
delphinids. Pacific stocks of delphinid species found in the Study Area
are not depleted under the MMPA. Consequently, the activities are not
expected to adversely impact annual rates of recruitment or survival of
delphinid species.
Killer Whales--The Navy's acoustic analysis predicts 250 instances
of Level B harassment of killer whales (Alaska Resident, Northern
Resident, West Coast Transient, Eastern North Pacific Offshore, and
Eastern North Pacific Southern Resident stocks), including 2 Level B
takes of southern resident killer whales, from sonar and other active
acoustic sources during annual training activities in the Study Area.
Relative to population sizes (killer whale stock abundance estimates
are shown in Table 9), these activities are anticipated to generally
result only in a limited number of level B harassment takes. When the
numbers of behavioral takes are compared to the estimated stock
abundance and if one assumes that each take happens to a separate
animal, less than 15 percent of all killer whale stocks--and 2 percent
of the Southern Resident stock of killer whale--would be behaviorally
harassed during the course of a year. More likely, slightly fewer
individuals would harassed, but a subset would be harassed more than
one time during the course of the year.
All of these takes are anticipated to be in the form of behavioral
harassment (TTS and behavioral reaction) and no injurious takes of
killer whales from sonar and other active acoustic stressors or
explosives are requested or proposed for authorization. Further, the
majority of takes are anticipated to be by behavioral harassment in the
form of

[[Page 31808]]

mild responses. Behavioral responses can range from a mild orienting
response, or a shifting of attention, to flight and panic (Richardson,
1995; Nowacek, 2007; Southall et al., 2007). Killer whales generally
travel in pods and should be visible from a distance in order to
implement mitigation measures and reduce potential impacts. Recovery
from a threshold shift (TTS) can take a few minutes to a few days,
depending on the exposure duration, sound exposure level, and the
magnitude of the initial shift, with larger threshold shifts and longer
exposure durations requiring longer recovery times (Finneran et al.,
2005; Mooney et al., 2009a; Mooney et al., 2009b; Finneran and
Schlundt, 2010). Large threshold shifts are not anticipated for these
activities because of the unlikelihood that animals will remain within
the ensonified area (due to the short duration of the majority of
exercises, the speed of the vessels, and the short distance within
which the animal would need to approach the sound source) at high
levels for the duration necessary to induce larger threshold shifts.
Threshold shifts do not necessarily affect all hearing frequencies
equally, so some threshold shifts may not interfere with an animal's
hearing of biologically relevant sounds.
The southern resident killer whale is the only ESA-listed marine
mammal species with designated critical habitat located in the NWTT
Study Area (NMFS, 2006). The majority of the Navy's proposed training
and testing activities would, however, not occur in the southern
resident killer whale's designated critical habitat (NMFS, 2006). For
all substressors that would occur within the critical habitat, those
training and testing activities are not expected to impact the
identified primary constituent elements of that habitat and therefore
would have no effect on that critical habitat. Furthermore, the
majority of testing events would occur in Hood Canal, where southern
resident killer whales are not believed to be present, while the
majority of training activities would occur in the offshore portions of
the Study Area where they are only present briefly during their annual
migration period. Effects to designated critical habitat will be fully
analyzed in the Navy's and NMFS' internal ESA Section 7 consultations
for NWTT.
The whale's size and detectability makes it unlikely that these
animals would be exposed to the higher energy or pressure expected to
result in more severe effects. As stated above, the vocalizations of
killer whales fall directly into the frequency range in which TTS would
be incurred from the MFAS sources used during ASW exercises; however,
the Navy is conducting ASW exercises mainly in the Offshore Area while
killer whales are predominantly situated in the Inland Waters Area.
Both behavioral and auditory brainstem response techniques indicate
killer whales can hear a frequency range of 1 to 100 kHz and are most
sensitive at 20 kHz. This is one the lowest maximum-sensitivity
frequencies known among toothed whales (Szymanski et al., 1999).
The NWTT training and testing activities are generally not expected
to occur in an area/time of specific importance for reproductive,
feeding, or other known critical behaviors for killer whales.
Consequently, the activities are not expected to adversely impact
annual rates of recruitment or survival of killer whale species and
will therefore not result in population-level impacts.
Pinnipeds--The Navy's acoustic analysis predicts that the following
numbers of Level B harassment (TTS and behavioral reaction) may occur
annually from sonar and other active acoustic stressors and sound or
energy from explosions associated with training and testing activities
in the Study Area: 908 Steller sea lions (Eastern U.S. stock); 10
Guadalupe fur seals (San Miguel Island stock); 2,887 California sea
lions (U.S. stock); 4,389 northern fur seals (Eastern Pacific and
California stocks); 2,596 northern elephant seals (California Breeding
stock); and 63,475 harbor seals (Southeast Alaska [Clarence Strait],
Oregon/Washington Coast, Washington Northern Inland Waters, Southern
Puget Sound, and Hood Canal stocks). These estimates represents the
total number of exposures and not necessarily the number of individuals
exposed, as a single individual may be exposed multiple times over the
course of a year. Northern elephant seals are the only pinnipeds
predicted to incur takes (one Level B take) from exposure to
explosives. The acoustic analysis (factoring in the post-model
correction for avoidance and mitigation) also indicates that 2 Northern
elephant seals and 92 harbor seals would be exposed to sound levels
likely to result in Level A harassment (PTS) from sonar or other active
acoustic sources.
Research has demonstrated that for pinnipeds, as for other mammals,
recovery from a hearing threshold shift (i.e., TTS; temporary partial
hearing loss) can take a few minutes to a few days depending on the
severity of the initial shift. More severe shifts may not fully recover
and thus would be considered PTS. However, large degrees of PTS are not
anticipated for these activities because of the unlikelihood that
animals will remain within the ensonified area (due to the short
duration of the majority of exercises, the speed of the vessels, and
the short distance within which the animal would need to approach the
sound source) at high levels for the duration necessary to induce
larger threshold shifts. Threshold shifts do not necessarily affect all
hearing frequencies equally, so threshold shifts may not necessarily
interfere with an animal's ability to hear biologically relevant
sounds. The likely consequences to the health of an individual that
incurs PTS can range from mild to more serious, depending 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. Likely avoidance of intense activity and sound coupled with
mitigation measures would further reduce the potential for severe PTS
exposures to occur. 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.
Research and observations show that pinnipeds in the water may be
tolerant of anthropogenic noise and activity (a review of behavioral
reactions by pinnipeds to impulsive and non-impulsive noise can be
found in Richardson et al., 1995 and Southall et al., 2007). Available
data, though limited, suggest that exposures between approximately 90
and 140 dB SPL do not appear to induce strong behavioral responses in
pinnipeds exposed to nonpulse sounds in water (Jacobs and Terhune,
2002; Costa et al., 2003; Kastelein et al., 2006c). Based on the
limited data on pinnipeds in the water exposed to multiple pulses
(small explosives, impact pile driving, and seismic sources), exposures
in the approximately 150 to 180 dB SPL range generally have limited
potential to induce avoidance behavior in pinnipeds (Harris et al.,
2001; Blackwell et al., 2004; Miller et al., 2004). If pinnipeds are
exposed to sonar or other active acoustic sources 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 acoustic exposure.
Pinnipeds 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

[[Page 31809]]

behaviors, or avoid the immediate area by swimming away or diving.
Effects on pinnipeds in the Study Area that are taken by Level B
harassment, on the basis of reports in the literature as well as Navy
monitoring from past activities, will likely be limited to reactions
such as increased swimming speeds, increased surfacing time, or
decreased foraging (if such activity were occurring). Most likely,
individuals will simply move away from the sound source and be
temporarily displaced from those areas, or not respond at all. In areas
of repeated and frequent acoustic disturbance, some animals may
habituate or learn to tolerate the new baseline or fluctuations in
noise level. Habituation can occur when an animal's response to a
stimulus wanes with repeated exposure, usually in the absence of
unpleasant associated events (Wartzok et al., 2003). 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. Given their documented tolerance
of anthropogenic sound (Richardson et al., 1995 and Southall et al.,
2007), repeated exposures of individuals (e.g., harbor seals) to levels
of sound that may cause Level B harassment are unlikely to result in
hearing impairment or to significantly disrupt foraging behavior. As
stated above, pinnipeds may habituate to or become tolerant of repeated
exposures over time, learning to ignore a stimulus that in the past has
not accompanied any overt threat.
Thus, even repeated Level B harassment of some small subset of the
overall stock is unlikely to result in any significant realized
decrease in fitness to those individuals, and would not result in any
adverse impact to the stock as a whole. Evidence from areas where the
Navy extensively trains and tests provides some indication of the
possible consequences resulting from those proposed activities. In the
confined waters of Washington State's Hood Canal where the Navy has
been training and intensively testing for decades and harbor seals are
present year-round, the population level has remained stable suggesting
the area's carrying capacity may have been reached (Jeffries et al.,
2003). Within Puget Sound there are several locations where pinnipeds
use Navy structures (e.g., submarines, security barriers) for haulouts.
Given that animals continue to choose these areas for their resting
behavior, it would appear there are no long-term effects or
consequences to those animals as a result of ongoing and routine Navy
activities.
Generally speaking, pinniped stocks in the Study Area are thought
to be stable or increasing. Abundance estimates for pinniped stocks in
the Study Area are shown in Table 9. Relative to population size,
training and testing activities are anticipated to result only in a
limited number of takes for the majority of pinniped species. When the
numbers of takes are compared to the estimated stock abundances and if
one assumes that each take happens to a separate animal, less than 2
percent of each Steller sea lion, California sea lion, northern fur
seal, and northern elephant seal stock would be harassed (behaviorally)
during the course of a year. More likely, fewer individuals are
harassed, but a subset are harassed more than one time during the
course of the year. Takes of depleted (as defined under the MMPA)
stocks of northern fur seals (Eastern Pacific) and Guadalupe fur seals
(Mexoco) represent only 0.7 percent and 0.07 percent of their
respective stock.
NMFS has determined that the Level A and Level B harassment
exposures to the Hood Canal stock of harbor seals are not biologically
significant to the population because (1) the vast majority of the
exposures are within the non-injurious TTS or behavioral effects zones
and none of the estimated exposures result in mortality; (2) the
majority of predicted harbor seal exposures result from testing
activities which are generally of an intermittent or short duration and
should prevent animals from being exposed to stressors on a continuous
basis; (3) there are no indications that the historically occurring
activities resulting in these behavioral harassment exposures are
having any effect on this population's survival by altering behavior
patterns such as breeding, nursing, feeding, or sheltering; (4) the
population has been stable and likely at carrying capacity (Jeffries et
al., 2003; Gaydos et al., 2013); (5) the population continues to use
known large haulouts in Hood Canal and Dabob Bay that are adjacent to
Navy testing and training activities (London et al., 2012); (6) the
population continues to use known haulouts for pupping; and (7) the
population continues to use the waters in and around Dabob Bay and Hood
Canal.
The Guadalupe fur seal is the only ESA-listed pinniped species
found within the NWTT Study Area. Guadalupe fur seals are considered
``seasonally migrant'' and are present within the offshore portion of
the Study Area during the warm season (summer and early autumn) and
during that portion of the year may be exposed to sonar and other
active acoustic sources associated with training and testing
activities. Predicted Level B takes of Guadalupe fur seals in the Study
Area represent a negligible percentage of the San Miguel Island stock.
Furthermore, critical habitat has not been designated for Guadalupe fur
seals.
We believe that factors described above, as well as the available
body of evidence from past Navy activities in the Study Area,
demonstrate that the potential effects of the specified activity will
have only short-term effects on individuals. The NWTT training and
testing activities are not expected to occur in an area/time of
specific importance for reproductive, feeding, or other known critical
behaviors for pinnipeds. Consequently, the activities are not expected
to adversely impact annual rates of recruitment or survival of pinniped
species and will therefore not result in population-level impacts.

Long-Term Consequences

The best assessment of long-term consequences from training and
testing activities will be to monitor the populations over time within
a given Navy range complex. A U.S. workshop on Marine Mammals and Sound
(Fitch et al., 2011) indicated a critical need for baseline biological
data on marine mammal abundance, distribution, habitat, and behavior
over sufficient time and space to evaluate impacts from human-generated
activities on long-term population survival. The Navy has developed
monitoring plans for protected marine mammals occurring on Navy ranges
with the goal of assessing the impacts of training and testing
activities on marine species and the effectiveness of the Navy's
current mitigation practices. Continued monitoring efforts over time
will be necessary to completely evaluate the long-term consequences of
exposure to noise sources.
Since 2006 across all Navy Range Complexes (in the Atlantic, Gulf
of Mexico, and the Pacific), there have been more than 80 reports;
Major Exercise Reports, Annual Exercise Reports, and Monitoring
Reports. For the Pacific since 2011, there have been 29 monitoring and
exercise reports (as shown in Table 6-1 of the LOA application)
submitted to NMFS to further research goals aimed at understanding the
Navy's impact on the environment as it carries out its mission to train
and test.
In addition to this multi-year record of reports from across the
Navy, there have also been ongoing Behavioral Response Study research
efforts (in

[[Page 31810]]

Southern California and the Bahamas) specifically focused on
determining the potential effects from Navy mid-frequency sonar
(Southall et al., 2011, 2012; Tyack et al., 2011; DeRuiter et al.,
2013b; Goldbogen et al., 2013; Moretti et al., 2014). This multi-year
compendium of monitoring, observation, study, and broad scientific
research is informative with regard to assessing the effects of Navy
training and testing in general. Given that this record involves many
of the same Navy training and testing activities being considered for
the Study Area, and because it includes all the marine mammal taxonomic
families and many of the same species, this compendium of Navy
reporting is directly applicable to the Study Area. Other research
findings related to the general topic of long-term impacts are
discussed above in the Species/Group Specific Analysis.
Based on the findings from surveys in Puget Sound and research
efforts and monitoring before, during, and after training and testing
events across the Navy since 2006, NMFS' assessment is that it is
unlikely there would be impacts to populations of marine mammals having
any long-term consequences as a result of the proposed continuation of
training and testing in the ocean areas historically used by the Navy,
including the Study Area. This assessment of likelihood is based on
four indicators from areas in the Pacific where Navy training and
testing has been ongoing for decades: (1) Evidence suggesting or
documenting increases in the numbers of marine mammals present
(Calambokidis and Barlow, 2004; Calambokidis et al., 2009a; Falcone et
al., 2009; Hildebrand and McDonald, 2009; Berman-Kowalewski et al.,
2010; Moore and Barlow, 2011; Barlow et al. 2011; Falcone and Shorr,
2012; Kerosky et al., 2012; Smultea et al., 2013), (2) examples of
documented presence and site fidelity of species and long-term
residence by individual animals of some species (Hooker et al., 2002;
McSweeney et al., 2007; McSweeney et al., 2009; McSweeney et al., 2010;
Martin and Kok, 2011; Baumann-Pickering et al., 2012; Falcone and
Schorr, 2014), (3) use of training and testing areas for breeding and
nursing activities (Littnan, 2010), and (4) 6 years of comprehensive
monitoring data indicating a lack of any observable effects to marine
mammal populations as a result of Navy training and testing activities.
To summarize, while the evidence covers most marine mammal
taxonomic suborders, it is limited to a few species and only suggestive
of the general viability of those species in intensively used Navy
training and testing areas. There is no direct evidence that routine
Navy training and testing spanning decades has negatively impacted
marine mammal populations at any Navy Range Complex. Although there
have been a few strandings associated with use of sonar in other
locations (see U.S. Department of the Navy, 2013b), Ketten (2012) has
recently summarized, ``to date, there has been no demonstrable evidence
of acute, traumatic, disruptive, or profound auditory damage in any
marine mammal as the result of anthropogenic noise exposures, including
sonar.'' Therefore, based on the best available science (Barlow et al.,
2011; Falcone et al., 2009; Falcone and Schorr, 2012, 2014; Littnan,
2011; Martin and Kok, 2011; McCarthy et al., 2011; McSweeney et al.,
2007; McSweeney et al., 2009; Moore and Barlow, 2011; Tyack et al.,
2011; Southall et al., 2012; Manzano-Roth et al., 2013; DeRuiter et
al., 2013b; Goldbogen et al., 2013; Moretti et al., 2014; Smultea and
Jefferson, 2014), including data developed in the series of reports
submitted to NMFS, we believe that long-term consequences for
individuals or populations are unlikely to result from Navy training
and testing activities in the Study Area.

Preliminary Determination

Training and testing activities proposed in the NWTT Study Area
would result in Level B and Level A takes, as summarized in Tables 17-
21. Based on best available science, as summarized in this proposed
rule and in the January 2014 DEIS/OEIS (Section 3.4.4.1), NMFS
concludes that exposures to marine mammal species and stocks due to
NWTT activities would result in only short-term (temporary and short in
duration) and relatively infrequent effects to most individuals
exposed, and not of the type or severity that would be expected to be
additive for the generally small portion of the stocks and species
likely to be exposed. Marine mammal takes from Navy activities are not
expected to impact annual rates of recruitment or survival and will
therefore not result in population-level impacts for the following
reasons:
Most acoustic exposures (greater than 99 percent) are
within the non-injurious TTS or behavioral effects zones (Level B
harassment consisting of generally temporary modifications in behavior)
and none of the estimated exposures result in mortality.
Although the numbers presented in Tables 17-21 represent
estimated harassment under the MMPA, as described above, they are
conservative estimates of harassment, primarily by behavioral
disturbance, and made without taking into consideration all possible
reductions as a result of standard operating procedures and mitigation
measures (only a subset of mitigations are factored into the post-
modeling analysis).
Additionally, the protective measures described in the
Proposed Mitigation section above are designed to reduce sound exposure
and explosive effects on marine mammals to levels below those that may
cause physiological effects (injury) and to achieve the least
practicable adverse effect on marine mammal species or stocks.
Range complexes where intensive training and testing have
been occurring for decades have populations of multiple species with
strong site fidelity (including highly sensitive resident beaked whales
at some locations) and increases in the number of some species.
Years of monitoring of Navy-wide activities (since 2006)
have documented hundreds of thousands of marine mammals on the range
complexes and there are only two instances of overt behavioral change
that have been observed.
Years of monitoring of Navy-wide activities on the range
complexes have documented no demonstrable instances of injury to marine
mammals as a direct result of non-impulsive acoustic sources.
In at least three decades of the same type of activities,
only one instance of injury to marine mammals (March 4, 2011; three
long-beaked common dolphin off Southern California) has occurred as a
known result of training or testing using an impulsive source
(underwater explosion). Of note, the time-delay firing underwater
explosive training activity implicated in the March 4 incident is not
proposed for the training activities in the NWTT Study Area.
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 NWTT 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.

[[Page 31811]]

Subsistence Harvest of Marine Mammals

There are no relevant subsistence uses of marine mammals implicated
by this action. Therefore, NMFS has determined that the total taking of
affected species or stocks would not have an unmitigable adverse impact
on the availability of such species or stocks for taking for
subsistence purposes.

ESA

There are nine marine mammal species under NMFS jurisdiction that
are listed as endangered or threatened under the ESA with confirmed or
possible occurrence in the NWTT Study Area: North Pacific right whale,
blue whale, humpback whale, fin whale, sei whale, gray whale (Western
North Pacific stock), sperm whale, killer whale (Eastern North Pacific
Southern Resident stock), and Guadalupe fur 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 NWTT activities. Consultation will be concluded prior to a
determination on the issuance of the final rule and an LOA.

NEPA

NMFS is a cooperating agency on the Navy's NWTT DEIS/OEIS, which
was prepared and released to the public in January 2014. Upon
completion, the Final EIS/OEIS (FEIS/OEIS) will be made available for
public review and posted on NMFS' Web site: http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm. NMFS intends to adopt the Navy's
NWTT FEIS/OEIS, if adequate and appropriate. Currently, we believe that
the adoption of the Navy's NWTT FEIS/OEIS will allow NMFS to meet its
responsibilities under NEPA for the issuance of regulations and LOAs
for NWTT. If necessary, however, NMFS will supplement the existing
analysis to ensure that we comply with NEPA prior to the issuance of
the final rule or LOA.

NMSA

Some Navy NWTT activities will occur within the Olympic Coast
National Marine Sanctuary (OCNMS). Federal agency actions that are
likely to injure sanctuary resources are subject to consultation with
the NOAA Office of National Marine Sanctuaries (ONMS) under section
304(d) of the National Marine Sanctuaries Act (NMSA). The Navy analyzed
potential impacts to sanctuary resources and has provided the analysis
in the January 2014 NWTT DEIS/OEIS. Where the Navy either proposes new
military activities or proposes to modify existing military activities
that are otherwise exempted by individual sanctuary regulations at 15
CFR part 922 in a way that the modified activities would adversely
impact sanctuary resources and qualities, the Navy will initiate
consultation with ONMS.
NMFS is currently consulting with ONMS on the issuance of
regulations and LOAs for NWTT activities. Consultation will be
concluded prior to a determination on the issuance of the final rule
and an 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: May 26, 2015.
Samuel D. Rauch III,
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 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. In Sec. 218.75, revise introductory paragraph (f)(1)(ii)(F) as
follows:

Sec. 218.75 Requirements for monitoring and reporting.

* * * * *
(f) * * *
(1) * * *
(ii) * * *
(F) Individual marine mammal sighting information for each sighting
when mitigation occurred during each MTE.
* * * * *
0
3. In Sec. 218.85, revise introductory paragraph (f)(1)(ii)(F) as
follows:

Sec. 218.85 Requirements for monitoring and reporting.

* * * * *
(f) * * *
(1) * * *
(ii) * * *
(F) Individual marine mammal sighting information for each sighting
when mitigation occurred during each MTE.
* * * * *
0
4. In Sec. 218.125, revise introductory paragraph (f)(1)(ii) as
follows:

Sec. 218.125 Requirements for monitoring and reporting.

* * * * *
(f) * * *
(1) * * *
(ii) Individual marine mammal sighting information for each
sighting in each exercise when mitigation occurred.
* * * * *

Subpart M--[Removed and Reserved]

0
5. Remove and reserve subpart M, consisting of Sec. Sec. 218.110
through 218.119.

Subpart R--[Removed and Reserved]

0
6. Remove and reserve subpart R, consisting of Sec. Sec. 218.170
through 218.178.
0
7. Subpart O is added to part 218 to read as follows:

[[Page 31812]]

Subpart O--Taking and Importing Marine Mammals; U.S. Navy's Northwest
Training and Testing (NWTT) Study Area
Sec.
218.140 Specified activity and specified geographical region.
218.141 Effective dates and definitions.
218.142 Permissible methods of taking.
218.143 Prohibitions.
218.144 Mitigation.
218.145 Requirements for monitoring and reporting.
218.146 Applications for Letters of Authorization
218.147 Letters of Authorization.
218.148 Renewal and Modifications of Letters of Authorization and
Adaptive Management.

Subpart O--Taking and Importing Marine Mammals; U.S. Navy's
Northwest Training and Testing (NWTT) Study Area

Sec. 218.140 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 NWTT Study Area, which is composed of established
maritime operating and warning areas in the eastern North Pacific Ocean
region, including areas of the Strait of Juan de Fuca, Puget Sound, and
Western Behm Canal in southeastern Alaska. The Study Area includes air
and water space within and outside Washington state waters, and outside
state waters of Oregon and Northern California. The Study Area includes
four existing range complexes and facilities: The Northwest Training
Range Complex (NWTRC), the Keyport Range Complex, Carr Inlet Operations
Area, and SEAFAC. In addition to these range complexes, the Study Area
also includes Navy pierside locations where sonar maintenance and
testing occurs as part of overhaul, modernization, maintenance and
repair activities at NAVBASE Kitsap, Bremerton; NAVBASE Kitsap, Bangor;
and Naval Station Everett.
(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) Sonar and other Active Sources Used During Training:
(i) Mid-frequency (MF) Source Classes:
(A) MF1--an average of 166 hours per year.
(B) MF3--an average of 70 hours per year.
(C) MF4--an average of 4 hours per year.
(D) MF5--an average of 896 items per year.
(E) MF11--an average of 16 hours per year.
(ii) High-frequency (HF) Source Classes:
(A) HF1--an average of 48 hours per year.
(B) HF4--an average of 384 hours per year.
(C) HF6--an average of 192 items per year.
(iii) Anti-Submarine Warfare (ASW) Source Classes:
(A) ASW2--an average of 720 items per year per year.
(B) ASW3--an average of 78 hours per year.
(2) Sonar and other Active Sources Used During Testing:
(i) Low-frequency (LF) Source Classes:
(A) LF4--an average of 110 hours per year.
(B) LF5--an average of 71 hours per year.
(ii) Mid-frequency (MF):
(A) MF3--an average of 161 hours per year.
(B) MF4--an average of 10 hours per year.
(C) MF5--an average of 273 items per year.
(D) MF6--an average of 12 items per year.
(E) MF8--an average of 40 hours per year.
(F) MF9--an average of 1,183 hours per year.
(G) MF10--an average of 1,156 hours per year.
(H) MF11--an average of 34 hours per year.
(I) MF12--an average of 24 hours per year.
(iii) High-frequency (HF) and Very High-frequency (VHF):
(A) HF1--an average of 161 hours per year.
(B) HF3--an average of 145 hours per year.
(C) HF5--an average of 360 hours per year.
(D) HF6--an average of 2,099 hours per year.
(iv) VHF:
(A) VHF2--an average of 35 hours per year.
(v) ASW:
(A) ASW1--an average of 16 hours per year.
(B) ASW2--an average of 64 hours per year.
(C) ASW2--an average of 170 items per year.
(D) ASW3--an average of 444 hours per year.
(E) ASW4--an average of 1,182 items per year.
(vi) Acoustic Modems (M):
(A) M3--an average of 1,519 hours per year.
(vii) Torpedoes (TORP):
(A) TORP1--an average of 315 items per year.
(B) TORP2--an average of 299 items per year.
(viii) Swimmer Detection Sonar (SD):
(A) SD1--an average of 757 hours per year.
(ix) Synthetic Aperture Sonar (SAS):
(A) SAS2--an average of 798 hours per year.
(3) Impulsive Source Detonations During Training:
(i) Explosive Classes:
(A) E1 (0.1 to 0.25 pound [lb] NEW)--an average of 48 detonations
per year.
(B) E3 (>0.5 to 2.5 lb NEW)--an average of 6 detonations per year.
(C) E5 (>5 to 10 lb NEW)--an average of 80 detonations per year.
(D) E10 (>250 to 500 lb NEW)--an average of 4 detonations per year.
(E) E12 (>650 to 1,000 lb NEW)--an average of 10 detonations per
year.
(ii) [Reserved].
(4) Impulsive Source Detonations During Testing:
(i) Explosive Classes:
(A) E3 (>0.5 to 2.5 lb NEW)--an average of 72 detonations per year.
(B) E4 (>2.5 to 5 lb NEW)--an average of 70 detonations per year.
(C) E8 (>60 to 100 lb NEW)--an average of 3 detonations per year.
(D) E11 (500 to 650 lb NEW)--an average of 3 detonations
per year.
(ii) [Reserved]

Sec. 218.141 Effective dates.

Regulations in this subpart are effective June 2, 2015 through June
2, 2020.

Sec. 218.142 Permissible methods of taking.

(a) Under Letters of Authorization (LOAs) issued pursuant to Sec.
218.147, the Holder of LOA may incidentally, but not intentionally,
take marine mammals within the area described in Sec. 218.140,
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. 218.140(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. 218.140(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:

[[Page 31813]]

(i) Mysticetes:
(A) Blue whale (Balaenoptera musculus)--25 (an average of 5 per
year).
(B) Fin whale (Balaenoptera physalus)--125 (an average of 25 per
year).
(C) Gray whale (Eschrichtius robustus)--30 (an average of 6 per
year).
(D) Humpback whale (Megaptera novaeangliae)--60 (an average of 12
per year).
(E) Minke whale (Balaenoptera acutorostrata)--90 (an average of 18
per year).
(ii) Odontocetes:
(A) Baird's beaked whale (Berardius bairdii)--2,955 (an average of
591 per year).
(B) Mesoplodont beaked whale Mesoplodon spp.)--7,085 (an average of
1,417 per year).
(C) Cuvier's beaked whale Ziphius cavirostris--1,765 (an average of
353 per year).
(D) Dall's porpoise Phocoenoidea dalli--18,188 (an average of 3,732
per year).
(E) Harbor porpoise Phocoena phocoena--441,984 (an average of
88,932 per year).
(F) Killer whale Orcinus orca--110 (an average of 24 per year).
(G) Kogia spp.--365 (an average of 73 per year).
(H) Northern right whale dolphin Lissodelphis borealis--6,660 (an
average of 1,332 per year).
(I) Pacific white-sided dolphin Lagenorhynchus obliquidens--17,408
(an average of 3,482 per year).
(J) Risso's dolphin Grampus griseus--3,285 (an average of 657 per
year).
(K) Short-beaked common dolphin Delphinus delphis--3,670 (an
average of 734 per year).
(L) Sperm whale Physeter macrocephalus--405 (an average of 81 per
year).
(M) Striped dolphin Stenella coerulealba--110 (an average of 22 per
year).
(iii) Pinnipeds:
(A) California sea lion Zalophus californianus--4,038 (an average
of 814 per year).
(B) Steller sea lion Eumetopias jubatus--1,986 (an average of 404
per year).
(C) Guadalupe fur seal Arctocephalus townsendi--35 (an average of 7
per year).
(D) Harbor seal Phoca vitulina--4,161 (an average of 832 per year).
(E) Northern elephant seal Mirounga angustirostris--6,353 (an
average of 1,271 per year).
(F) Northern fur seal Callorhinus ursinus--12,660 (an average of
2,532 per year).
(2) Level A Harassment for all Training Activities:
(i) Mysticetes:
(A) [Reserved]
(B) [Reserved]
(ii) Odontocetes:
(A) Dall's porpoise (Phocoenoidea dalli)--20 (an average of 4 per
year).
(B) Harbor porpoise (Phocoena phocoena)--5 (an average of 1 per
year).
(iii) Pinnipeds:
(A) Harbor seal (Phoca vitulina)--30 (an average of 6 per year).
(B) [Reserved]
(3) Level B Harassment for all Testing Activities:
(i) Mysticetes:
(A) Blue whale (Balaenoptera musculus)--30 (an average of 6 per
year).
(B) Fin whale (Balaenoptera physalus)--180 (an average of 36 per
year).
(C) Gray whale (Eschrichtius robustus)--55 (an average of 11 per
year).
(D) Humpback whale (Megaptera novaeangliae)--225 (an average of 45
per year).
(E) Minke whale (Balaenoptera acutorostrata)--90 (an average of 18
per year).
(F) Sei whale (Balaenoptera borealis)--10 (an average of 2 per
year).
(ii) Odontocetes:
(A) Baird's beaked whale (Berardius bairdii)--870 (an average of
174 per year).
(B) Mesoplodont beaked whale (Mesoplodon spp.)--1,845 (an average
of 369 per year).
(C) Cuvier's beaked whale (Ziphius cavirostris)--530 (an average of
106 per year).
(D) Dall's porpoise (Phocoenoidea dalli)--56,695 (an average of
11,339 per year).
(E) Harbor porpoise (Phocoena phocoena)--246,465 (an average of
49,293 per year).
(F) Killer whale (Orcinus orca)--1, 130 (an average of 226 per
year).
(G) Kogia spp.--530 (an average of 106 per year).
(H) Northern right whale dolphin (Lissodelphis borealis)--10 (an
average of 2,038 per year).
(I) Pacific white-sided dolphin (Lagenorhynchus obliquidens)--
24,360 (an average of 4,872 per year).
(J) Risso's dolphin (Grampus griseus)--5,770 (an average of 1,154
per year).
(K) Short-beaked common dolphin (Delphinus delphis)--8,140 (an
average of 1,628 per year).
(L) Sperm whale (Physeter macrocephalus)--390 (an average of 78 per
year).
(M) Striped dolphin (Stenella coerulealba)--70 (an average of 14
per year).
(iii) Pinnipeds:
(A) California sea lion (Zalophus californianus)--10,365 (an
average of 2,073 per year).
(B) Steller sea lion (Eumetopias jubatus)--2,520 (an average of 504
per year).
(C) Guadalupe fur seal (Arctocephalus townsendi)--15 (an average of
3 per year).
(D) Harbor seal (Phoca vitulina)--312,690 (an average of 62,538 per
year).
(E) Northern elephant seal (Mirounga angustirostris)--6,625 (an
average of 1,325 per year).
(F) Northern fur seal (Callorhinus ursinus)--9,285 (an average of
1,857 per year).
(4) Level A Harassment for all Testing Activities:
(i) Mysticetes:
(A) [Reserved]
(B) [Reserved]
(ii) Odontocetes:
(A) Kogia spp.--5 (an average of 1 per year).
(B) Dall' porpoise (Phocoenoidea dalli)--215 (an average of 43 per
year).
(C) Harbor porpoise (Phocoena phocoena)--220 (an average of 44 per
year).
(iii) Pinnipeds:
(A) Harbor seal (Phoca vitulina)--430 (an average of 86 per
year).(B) Northern elephant seal (Mirounga angustirostris)--10 (an
average of 2 per year).
(C) [Reserved]

Sec. 218.143 Prohibitions.

Notwithstanding takings contemplated in Sec. 218.142 and
authorized by an LOA issued under Sec. Sec. 216.106 and 218.147 of
this chapter, no person in connection with the activities described in
Sec. 218.140 may:
(a) Take any marine mammal not specified in Sec. 218.142(c);
(b) Take any marine mammal specified in Sec. 218.142(c) other than
by incidental take as specified in Sec. 218.142(c);
(c) Take a marine mammal specified in Sec. 218.142(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 218.147.

Sec. 218.144 Mitigation.

(a) When conducting training and testing activities, as identified
in Sec. 218.140, the mitigation measures

[[Page 31814]]

contained in the LOA issued under Sec. Sec. 216.106 and 218.147 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.
(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 mitigation zones, and monitoring for vessel and personnel
safety concerns.
(ii) Lookouts positioned ashore, 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 in paragraph (a)(1)(i) of this
section.
(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 or shore-based testing or maintenance) will
maintain one Lookout.
(D) Small boats, range craft, minimally manned vessels, or aircraft
conducting hull-mounted mid-frequency testing will employ one Lookout.
(E) Ships or aircraft conducting non-hull-mounted mid-frequency
active sonar, such as helicopter dipping sonar systems, will maintain
one Lookout.
(F) 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.
(iv) Lookout measures for explosives and impulsive sound:
(A) Aircraft conducting improved extended echo ranging sonobuoy
activities will have one Lookout.
(B) Aircraft conducting explosive sonobuoy activities using >0.5 to
2.5-lb net explosive weight (NEW) will have one Lookout.
(C) General mine countermeasure and neutralization activities
involving positive control diver placed charges using >0.5 to 2.5 lb
NEW will have a total of two Lookouts (one Lookout positioned in each
of the two support vessels). All divers placing the charges on mines
will support the Lookouts while performing their regular duties. The
divers and Lookouts will report all marine mammal sightings to their
dive support vessel.
(D) Surface vessels or aircraft conducting small- and medium-
caliber gunnery exercises will have one Lookout. Towing vessels, if
applicable, will also maintain one Lookout.
(E) Aircraft conducting missile exercises against a surface target
will have one Lookout.
(F) Aircraft conducting explosive bombing exercises will have one
Lookout and any surface vessels involved will have trained Lookouts.
(G) During explosive torpedo testing from aircraft one Lookout will
be used and positioned in an aircraft. During explosive torpedo testing
from a surface ship the Lookout procedures implemented for hull-mounted
mid-frequency active sonar activities will be used.
(H) Ships conducting explosive and non-explosive large-caliber
gunnery exercises will have one Lookout. This may be the same Lookout
used for small, medium, and large-caliber gunnery exercises using a
surface target when that activity is conducted from a ship against a
surface target.
(v) 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 towed from a
manned platform, one Lookout will be used. During activities in which
in-water devices are towed by unmanned platforms, a manned escort
vessel will be included and one Lookout will be employed.
(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 non-explosive bombing exercises one Lookout will be
positioned in an aircraft and trained Lookouts will be positioned in
any surface vessels involved.
(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 (or sea turtles) 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:
(A) The Navy shall ensure that hull-mounted mid-frequency active
sonar transmission levels are limited to at least 6 dB below normal
operating levels if any detected marine mammals (or sea turtles) are
within 1,000 yd. (914 m) of the sonar dome (the bow).
(B) The Navy shall ensure that 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 (or sea turtles)
are within 500 yd. (457 m) of the sonar dome.
(C) The Navy shall ensure that hull-mounted mid-frequency active
sonar transmissions are ceased if any detected cetaceans (or sea
turtles) are within 200 yd. (180 m) and pinnipeds are within 100 yd.
(90 m) of the sonar dome. Transmissions will not resume until the
marine mammal has been observed exiting the mitigation zone, is thought
to have exited the mitigation zone based on its course and speed, has
not been detected for 30 minutes, the vessel has transited more than
2,000 yd. beyond the location of the last detection, or the Lookout
concludes that dolphins are deliberately closing in on the ship to ride
the ship's bow wave (and there are no other marine mammal sightings
within the mitigation zone). Active transmission may resume when
dolphins are bow riding because they are out of the main transmission
axis of the active sonar while in the shallow-wave area of the ship
bow. The pinniped mitigation zone does not apply for pierside or shore-
based testing in the vicinity of pinnipeds hauled out on man-made
structures and vessels.
(D) The Navy shall ensure that low-frequency active sonar
transmission levels are ceased if any detected cetaceans (or sea
turtles) are within 200 yd. (180 m) and pinnipeds are within 100 yd.
(90 m) of the source. Transmissions will not resume until the marine
mammal has been observed

[[Page 31815]]

exiting the mitigation zone, is thought to have exited the mitigation
zone based on its course and speed, has not been detected for 30
minutes, or the vessel has transited more than 2,000 yd. beyond the
location of the last detection. The pinniped mitigation zone does not
apply for pierside testing in the vicinity of pinnipeds hauled out on
man-made structures and vessels.
(E) The Navy shall ensure that high-frequency and non-hull-mounted
mid-frequency active sonar transmission levels are ceased if any
detected cetaceans are within 200 yd. (180 m) and pinnipeds are within
100 yd. (90 m) of the source. Transmissions will not resume until the
marine mammal has been observed exiting the mitigation zone, is thought
to have exited the mitigation zone based on its course and speed, the
mitigation zone has been clear from any additional sightings for a
period of 10 minutes for an aircraft-deployed source, the mitigation
zone has been clear from any additional sightings for a period of 30
minutes for a vessel-deployed source, the vessel or aircraft has
repositioned itself more than 400 yd. (370 m) away from the location of
the last sighting, or the vessel concludes that dolphins are
deliberately closing in to ride the vessel's bow wave (and there are no
other marine mammal sightings within the mitigation zone). The pinniped
mitigation zone does not apply for pierside or shore-based testing in
the vicinity of pinnipeds hauled out on man-made structures and
vessels.
(iv) Mitigation zones for explosive and impulsive sound:
(A) For activities using IEERs, explosive detonations will cease if
a marine mammal, sea turtle, or concentrations of floating vegetation
are sighted within a 600-yd. (550 m) mitigation zone. Detonations will
recommence if the animal is observed exiting the mitigation zone, the
animal is thought to have exited the mitigation zone based on its
course and speed, or the mitigation zone has been clear from any
additional sightings for a period of 30 minutes.
(B) A mitigation zone with a radius of 350 yd. (320 m) shall be
established for explosive signal underwater sonobuoys using >0.5 to 2.5
lb net explosive weight. Detonations will recommence if the animal is
observed exiting the mitigation zone, the animal is thought to have
exited the mitigation zone based on its course and speed, or the
mitigation zone has been clear from any additional sightings for a
period of 10 minutes.
(C) A mitigation zone with a radius of 400 yd. (366 m) shall be
established for mine countermeasures and neutralization activities
using positive control firing devices. Explosive detonations will cease
if a marine mammal is sighted in the water portion of the mitigation
zone (i.e., not on shore). Detonations will recommence if the animal is
observed exiting the mitigation zone, the animal is thought to have
exited the mitigation zone based on its course and speed, or the
mitigation zone has been clear from any additional sightings for a
period of 30 minutes.
(D) A mitigation zone with a radius of 200 yd. (180 m) shall be
established for small- and medium-caliber gunnery exercises with a
surface target. Firing will cease if a marine mammal is sighted within
the mitigation zone. Firing will recommence if the animal is observed
exiting the mitigation zone, the animal is thought to have exited the
mitigation zone based on its course and speed, the mitigation zone has
been clear from any additional sightings for a period of 10 minutes for
a firing aircraft, the mitigation zone has been clear from any
additional sightings for a period of 30 minutes for a firing ship, or
the intended target location has been repositioned more than 400 yd.
(370 m) away from the location of the last sighting.
(E) A mitigation zone with a radius of 600 yd. (550 m) shall be
established for large-caliber gunnery exercises with a surface target.
Firing will cease if a marine mammal is sighted within the mitigation
zone. Firing will recommence if the animal is observed exiting the
mitigation zone, the animal is thought to have exited the mitigation
zone based on its course and speed, or the mitigation zone has been
clear from any additional sightings for a period of 30 minutes.
(F) The Navy is not proposing to use missiles with less than a 251
lb NEW warhead in the NWTT Study Area. However, should the need arise
to conduct training activities using missiles in this category, a
mitigation zone with a radius of 2,000 yd. (1.8 km) shall be
established for missile exercises with up to 250 lb net explosive
weight and a surface target. Firing will cease if a marine mammal is
sighted within the mitigation zone. Firing will recommence if the
animal is observed exiting the mitigation zone, the animal is thought
to have exited the mitigation zone based on its course and speed, or
the mitigation zone has been clear from any additional sightings for a
period of 10 minutes or 30 minutes (depending on aircraft type).
(G) A mitigation zone with a radius of 2,000 yd. (1.8 km) shall be
established for missile exercises with 251 to 500 lb NEW using a
surface target. Firing will cease if a marine mammal is sighted within
the mitigation zone. Firing will recommence if the animal is observed
exiting the mitigation zone, the animal is thought to have exited the
mitigation zone based on its course and speed, or the mitigation zone
has been clear from any additional sightings for a period of 10 minutes
or 30 minutes (depending on aircraft type).
(H) A mitigation zone with a radius of 2,500 yd. (2.3 km) around
the intended impact location for explosive bombs shall be established
for bombing exercises. Bombing will cease if a marine mammal is sighted
within the mitigation zone. Bombing will recommence if the animal is
observed exiting the mitigation zone, the animal is thought to have
exited the mitigation zone based on its course and speed, or the
mitigation zone has been clear from any additional sightings for a
period of 10 minutes.
(I) A mitigation zone with a radius of 2,100 yd. (1.9 km) shall be
established for torpedo (explosive) testing. Firing will cease if a
marine mammal, sea turtle, or concentrations of floating vegetation are
sighted within the mitigation zone. Firing will recommence if the
animal is observed exiting the mitigation zone, the animal is thought
to have exited the mitigation zone based on its course and speed, or
the mitigation zone has been clear from any additional sightings for a
period of 10 minutes or 30 minutes (depending on aircraft type).
(iii) Mitigation zones for vessels and in-water devices:
(A) A mitigation zone of 500 yd. (460 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 during training
activities, providing it is safe to do so. During testing activities,
all range craft (vessels and aircraft, including helicopters) shall not
approach within 100 yd. (90 m) of marine mammals.
(B) A mitigation zone of 250 yd. (230 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. (180 m) shall be established for
small, medium, and large caliber gunnery exercises using a surface
target. Firing will cease if a marine mammal is sighted within the
mitigation zone. Firing will recommence if the animal is observed
exiting the mitigation zone, the animal is thought to have exited the
mitigation zone based on its course and

[[Page 31816]]

speed, the mitigation zone has been clear from any additional sightings
for a period of 10 minutes for a firing aircraft, the mitigation zone
has been clear from any additional sightings for a period of 30 minutes
for a firing ship, or the intended target location has been
repositioned more than 400 yd. (370 m) away from the location of the
last sighting.
(B) A mitigation zone of 1,000 yd. (920 m) shall be established for
bombing exercises. Bombing will cease if a marine mammal is sighted
within the mitigation zone. Bombing will recommence if the animal is
observed exiting the mitigation zone, the animal is thought to have
exited the mitigation zone based on its course and speed, or the
mitigation zone has been clear from any additional sightings for a
period of 10 minutes.

Sec. 218.145 Requirements for monitoring and reporting.

(a) The Navy is required to cooperate with the NMFS, and any other
Federal, state or local agency monitoring the impacts of the activity
on marine mammals.
(b) General Notification of Injured or Dead Marine Mammals--Navy
personnel shall ensure that NMFS is notified immediately (or as soon as
clearance procedures allow) if an injured, stranded, or dead marine
mammal is found during or shortly after, and in the vicinity of, any
Navy training exercise utilizing MFAS, HFAS, or underwater explosive
detonations. The Navy will provide NMFS with species or description of
the animal(s), the condition of the animal(s) (including carcass
condition if the animal is dead), location, time of first discovery,
observed behaviors (if alive), and photo or video (if available). In
the event that an injured, stranded, or dead marine mammal is found by
the Navy that is not in the vicinity of, or during or shortly after,
MFAS, HFAS, or underwater explosive detonations, the Navy will report
the same information as listed above as soon as operationally feasible
and clearance procedures allow.
(c) General Notification of Ship Strike--In the event of a ship
strike by any Navy vessel, at any time or place, the Navy shall do the
following:
(1) Immediately report to NMFS the species identification (if
known), location (lat/long) of the animal (or the strike if the animal
has disappeared), and whether the animal is alive or dead (or unknown)
(2) Report to NMFS as soon as operationally feasible the size and
length of animal, an estimate of the injury status (ex., dead, injured
but alive, injured and moving, unknown, etc.), vessel class/type and
operational status.
(3) Report to NMFS the vessel length, speed, and heading as soon as
feasible.
(4) Provide NMFS a photo or video, if equipment is available
(d) Event Communication Plan--The Navy shall develop a
communication plan that will include all of the communication protocols
(phone trees, etc.) and associated contact information required for
NMFS and the Navy to carry out the necessary expeditious communication
required in the event of a stranding or ship strike, including as
described in the proposed notification measures above.
(e) The Navy must conduct all monitoring and/or research required
under the Letter of Authorization including abiding by the NWTT
Monitoring Plan (http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm).
(f) Annual NWTT Monitoring Plan Report--The Navy shall submit an
annual report of the NWTT Monitoring Plan describing the implementation
and results of the NWTT Monitoring Plan from the previous calendar
year. 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 NWTT Monitoring Plan shall, at a minimum, provide the same
marine mammal observation data required in Sec. 218.145. The report
shall be submitted either 90 days after the calendar year, or 90 days
after the conclusion of the monitoring year to be determined by the
Adaptive Management process.
The NWTT 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 (the multi-Range Complex Annual
Monitoring Report). Such a report would describe progress of knowledge
made with respect to monitoring plan study questions across all Navy
ranges associated with the ICMP. Similar study questions shall be
treated together so that progress on each topic shall be summarized
across all Navy ranges. The report need not include analyses and
content that does not provide direct assessment of cumulative progress
on the monitoring plan study questions.
(g) Annual NWTT Exercise and Testing Reports--The Navy shall submit
preliminary reports detailing the status of authorized sound sources
within 21 days after the anniversary of the date of issuance of the
LOA. The Navy shall submit detailed reports 3 months after the
anniversary of the date of issuance of the LOA. The detailed annual
reports shall describe the level of training and testing conducted
during the reporting period, and a summary of sound sources used (total
annual hours or quantity [per the LOA] of each bin of sonar or other
non-impulsive source; total annual number of each type of explosive
exercises; total annual expended/detonated rounds [missiles, bombs,
etc.] for each explosive bin; and improved Extended Echo-Ranging System
(IEER)/sonobuoy summary, including total number of IEER events
conducted in the Study Area, total expended/detonated rounds (buoys),
and total number of self-scuttled IEER rounds. The analysis in the
detailed reports will be based on the accumulation of data from the
current year's report and data collected from previous reports.
(h) 5-year Close-out Exercise and Testing Report--This report will
be included as part of the 2020 annual exercise or testing report. This
report will provide the annual totals for each sound source bin with a
comparison to the annual allowance and the 5-year total for each sound
source bin with a comparison to the 5-year allowance. Additionally, if
there were any changes to the sound source allowance, this report will
include a discussion of why the change was made and include the
analysis to support how the change did or did not result in a change in
the SEIS and final rule determinations. The report will be submitted 3
months after the expiration of the rule. NMFS will submit comments on
the draft close-out report, if any, within 3 months of receipt. The
report will be considered final after the Navy has addressed NMFS'
comments, or 3 months after the submittal of the draft if NMFS does not
provide comments.

Sec. 218.146 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. 218.140(c) (the U.S. Navy) must apply
for and obtain either an initial LOA in accordance with Sec. 218.147
or a renewal under Sec. 218.148.

Sec. 218.147 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:

[[Page 31817]]

(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. 218.148 Renewals and Modifications of Letters of Authorization
and Adaptive Management.

(a) A Letter of Authorization issued under Sec. Sec. 216.106 and
218.147 of this chapter for the activity identified in Sec. 218.140(c)
will be renewed or modified upon request of the applicant, provided
that:
(1) The proposed specified activity and mitigation, monitoring, and
reporting measures, as well as the anticipated impacts, are the same as
those described and analyzed for these regulations (excluding changes
made pursuant to the adaptive management provision of this chapter),
and;
(2) NMFS determines that the mitigation, monitoring, and reporting
measures required by the previous LOA under these regulations were
implemented.
(b) For LOA modification or renewal requests by the applicant that
include changes to the activity or the mitigation, monitoring, or
reporting (excluding changes made pursuant to the adaptive management
provision of this chapter) that do not change the findings made for the
regulations or result in no more than a minor change in the total
estimated number of takes (or distribution by species or years), NMFS
may publish a notice of proposed LOA in the Federal Register, including
the associated analysis illustrating the change, and solicit public
comment before issuing the LOA.
(c) An LOA issued under Sec. 216.106 and Sec. 218.147 of this
chapter for the activity identified in Sec. 218.144 of this chapter
may be modified by NMFS under the following circumstances:
(1) Adaptive Management--NMFS may modify (including augment) the
existing mitigation, monitoring, or reporting measures (after
consulting with the Navy regarding the practicability of the
modifications) if doing so creates a reasonable likelihood of more
effectively accomplishing the goals of the mitigation and monitoring
set forth in the preamble for these regulations.
(i) Possible sources of data that could contribute to the decision
to modify the mitigation, monitoring, and reporting measures in an LOA:
(A) Results from Navy's monitoring from the previous year(s);
(B) Results from other marine mammal and/or sound research or
studies; or
(C) Any information that reveals marine mammals may have been taken
in a manner, extent, or number not authorized by these regulations or
subsequent LOAs.
(ii) If, through adaptive management, the modifications to the
mitigation, monitoring, or reporting measures are substantial, NMFS
would publish a notice of proposed LOA in the Federal Register and
solicit public comment.
(2) Emergencies--If NMFS 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. 218.142(c), an LOA may be modified
without prior notification and an opportunity for public comment.
Notification would be published in the Federal Register within 30 days
of the action.

[FR Doc. 2015-13038 Filed 6-2-15; 8:45 am]
BILLING CODE 3510-22-P