Federal Register, Volume 83 Issue 49 (Tuesday, March 13, 2018)

[Federal Register Volume 83, Number 49 (Tuesday, March 13, 2018)]
[Proposed Rules]
[Pages 10954-11096]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-04517]

[[Page 10953]]

Vol. 83

Tuesday,

No. 49

March 13, 2018

Part II

Department of Commerce

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National Oceanic and Atmospheric Administration

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50 CFR Part 218

Taking and Importing Marine Mammals; Taking Marine Mammals Incidental
to the U.S. Navy Training and Testing Activities in the Atlantic Fleet
Training and Testing Study Area; Proposed Rule

Federal Register / Vol. 83 , No. 49 / Tuesday, March 13, 2018 /
Proposed Rules

[[Page 10954]]

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 218

[Docket No. 170720687-8212-01]
RIN 0648-BH06

Taking and Importing Marine Mammals; Taking Marine Mammals
Incidental to the U.S. Navy Training and Testing Activities in the
Atlantic Fleet 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 Atlantic Fleet Training and Testing
(AFTT) Study Area. 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
take marine mammals during the specified activities. NMFS will consider
public comments prior to issuing any final rule and making final
decisions on the issuance of the requested MMPA authorizations. Agency
responses to public comments will be summarized in the final notice of
our decision. The Navy's activities qualify as military readiness
activities pursuant to the MMPA, as amended by the National Defense
Authorization Act for Fiscal Year 2004 (2004 NDAA).

DATES: Comments and information must be received no later than April
26, 2018.

ADDRESSES: You may submit comments, identified by NOAA-NMFS-2018-0037,
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-2018-0037, 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 may be publicly accessible. Do not submit Confidential
Business Information or otherwise sensitive or protected information.
NMFS will accept anonymous comments (enter ``N/A'' in the required
fields if you wish to remain anonymous). Attachments to electronic
comments will be accepted in Microsoft Word, Excel, or Adobe PDF file
formats only.

FOR FURTHER INFORMATION CONTACT: Stephanie Egger, Office of Protected
Resources, NMFS; phone: (301) 427-8401. Electronic copies of the
application and supporting documents, as well as a list of the
references cited in this document, may be obtained online at:
www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities. In case of problems
accessing these documents, please call the contact listed above.

SUPPLEMENTARY INFORMATION:

Background

Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)
direct the Secretary of Commerce (as delegated to NMFS) 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 and the opportunity
to submit comments.
An 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.''
NMFS has defined ``unmitigable adverse impact'' in 50 CFR 216.103
as ``. . . an impact resulting from the specified activity:
(1) That is likely to reduce the availability of the species to a
level insufficient for a harvest to meet subsistence needs by: (i)
Causing the marine mammals to abandon or avoid hunting areas; (ii)
directly displacing subsistence users; or (iii) placing physical
barriers between the marine mammals and the subsistence hunters; and
(2) That cannot be sufficiently mitigated by other measures to
increase the availability of marine mammals to allow subsistence needs
to be met.''
The MMPA states that the term ``take'' means to harass, hunt,
capture, kill or attempt to harass, hunt, capture, or kill any marine
mammal.
The 2004 NDAA (Pub. L. 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

On June 16, 2017, NMFS received an application from the Navy
requesting incidental take regulations and LOAs to take individuals of
39 marine mammal species by Level A and B harassment incidental to
training and testing activities (categorized as military readiness
activities) from the use of sonar and other transducers, in-water
detonations, airguns, and impact pile driving/vibratory extraction in
the AFTT Study Area over five years. In addition, the Navy is
requesting incidental take authorization for up to nine mortalities of
four marine mammal species during ship shock trials, and authorization
for up to three takes by serious injury or mortality from vessel

[[Page 10955]]

strikes over the five-year period. The Navy's training and testing
activities would occur over five years beginning November 2018. On
August 4, 2017, the Navy sent an amendment to its application and
Navy's rulemaking and LOA application was considered final and
complete.
The Navy's requests for two five-year LOAs, one for training and
one for testing activities to be conducted within the AFTT Study Area
(which includes areas of the western Atlantic Ocean along the east
coast of North America, portions of the Caribbean Sea, and the Gulf of
Mexico), covers approximately 2.6 million square nautical miles
(nmi\2\) of ocean area, oriented from the mean high tide line along the
U.S. coast and extends east to the 45-degree west longitude line, north
to the 65-degree north latitude line, and south to approximately the
20-degree north latitude line. Please refer to the Navy's rulemaking
and LOA application, specifically Figure 1.1-1 for a map of the AFTT
Study Area and Figures 2.2-1 through Figure 2.2-3 for additional maps
of the range complexes and testing ranges. The following types of
training and testing, which are classified as military readiness
activities pursuant to the MMPA, as amended by the 2004 NDAA, would be
covered under the LOAs (if authorized): Amphibious warfare (in-water
detonations), anti-submarine warfare (sonar and other transducers, in-
water detonations), expeditionary warfare (in-water detonations),
surface warfare (in-water detonations), mine warfare (sonar and other
transducers, in-water detonations), and other warfare activities (sonar
and other transducers, impact pile driving/vibratory extraction,
airguns). In addition, ship shock trials, a specific testing activity
related to vessel evaluation would be conducted.
This will be NMFS' third rulemaking for AFTT activities under the
MMPA. NMFS published the first rule effective from January 22, 2009
through January 22, 2014 on January 27, 2009 (74 FR 4844) and the
second rule applicable from November 14, 2013 through November 13, 2018
on December 4, 2013 (78 FR 73009). For this third rulemaking, the Navy
is proposing to conduct similar activities as they have conducted over
the past nine years under the previous two rulemakings.

Background of Request

The Navy's mission is to organize, train, equip, and maintain
combat-ready naval forces capable of winning wars, deterring
aggression, and maintaining freedom of the seas. This mission is
mandated by federal law (10 U.S.C. 5062), which ensures the readiness
of the naval forces of the United States. The Navy executes this
responsibility by establishing and executing training programs,
including at-sea training and exercises, and ensuring naval forces have
access to the ranges, operating areas (OPAREAs), and airspace needed to
develop and maintain skills for conducting naval activities.
The Navy proposes to conduct training and testing activities within
the AFTT Study Area. The Navy has been conducting military readiness
activities in the AFTT Study Area for well over a century and with
active sonar for over 70 years. 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
warfighting doctrine and procedures, and changes in force structure
(organization of ships, weapons, and personnel). Such developments
influenced the frequency, duration, intensity, and location of required
training and testing activities. This rulemaking and LOA request
reflects the most up to date compilation of training and testing
activities deemed necessary to accomplish military readiness
requirements. The types and numbers of activities included in the
proposed rule accounts for fluctuations in training and testing in
order to meet evolving or emergent military readiness requirements.
The Navy's rulemaking and LOA request covers training and testing
activities that would occur for a 5-year period following the
expiration of the current MMPA authorization for the AFTT Study Area,
which expires on November 13, 2018.

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 acoustic and explosives stressors are 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 AFTT Draft Environmental Impact Statement (EIS)/Overseas EIS (OEIS)
(DEIS/OEIS) and in the Navy's rulemaking and LOA application
(www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities) and are summarized
here.

Overview of Training and Testing Activities

The Navy routinely trains in the AFTT Study Area in preparation for
national defense missions. Training and testing activities and
exercises covered in the Navy's rulemaking and LOA application are
briefly described below, and in more detail within chapter 2 of the
AFTT DEIS/OEIS. Each military training and testing activity described
meets mandated Fleet requirements to deploy ready forces.

Primary Mission Areas

The Navy categorizes its activities into functional warfare areas
called primary mission areas. These activities generally fall into the
following seven primary mission areas: Air warfare; amphibious warfare;
anti-submarine warfare (ASW); electronic warfare; expeditionary
warfare; mine warfare (MIW); and surface warfare (SUW). Most activities
addressed in the AFTT DEIS/OEIS are categorized under one of the
primary mission areas; the testing community has three additional
categories of activities for vessel evaluation, unmanned systems, and
acoustic and oceanographic science and technology (inclusive of ship
shock trials). Activities that do not fall within one of these areas
are listed as ``other warfare activities.'' Each warfare community
(surface, subsurface, aviation, and expeditionary warfare) may train in
some or all of these primary mission areas. The testing community also
categorizes most, but not all, of its testing activities under these
primary mission areas.
The Navy describes and analyzes the impacts of its training and
testing activities within the AFTT DEIS/OEIS and the Navy's rulemaking
and LOA application (documents available at www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities). In its assessment, the Navy concluded
that sonar and other transducers, in-water detonations, airguns, and
pile driving/extraction were the stressors that would result in impacts
on marine mammals that could rise to the level of harassment (also
serious injury or mortality in ship shock trials or by vessel strike)
as defined under the MMPA. Therefore, the rulemaking and LOA
application provides the Navy's assessment of potential effects from
these stressors in terms of the various warfare mission areas in which
they would be conducted. In terms of Navy's primary warfare areas, this
includes:

[[Page 10956]]

Amphibious warfare (in-water detonations)
anti-submarine warfare (sonar and other transducers, in-water
detonations)
expeditionary warfare (in-water detonations)
surface warfare (in-water detonations)
mine warfare (sonar and other transducers, in-water
detonations)
other warfare activities (sonar and other transducers, impact
pile driving/vibratory extraction, airguns)

The Navy's training and testing activities in air warfare and
electronic warfare do not involve sonar or other transducers, in-water
detonations, pile driving/extraction, airguns or any other stressors
that could result in harassment, serious injury, or mortality of marine
mammals. Therefore, the activities in air warfare or electronic warfare
are not discussed further, but are analyzed fully in the Navy's AFTT
DEIS/OEIS.
Amphibious Warfare
The mission of amphibious warfare is to project military power from
the sea to the shore (i.e., attack a threat on land by a military force
embarked on ships) through the use of naval firepower and expeditionary
landing forces. Amphibious warfare operations include small unit
reconnaissance or raid missions to large-scale amphibious exercises
involving multiple ships and aircraft combined into a strike group.
Amphibious warfare training ranges from individual, crew, and small
unit events to large task force exercises. Individual and crew training
include amphibious vehicles and naval gunfire support training. Such
training includes shore assaults, boat raids, airfield or port
seizures, and reconnaissance. Largescale amphibious exercises involve
ship-to-shore maneuver, naval fire support, such as shore bombardment,
and air strike and attacks on targets that are in close proximity to
friendly forces.
Testing of guns, munitions, aircraft, ships, and amphibious vessels
and vehicles used in amphibious warfare are often integrated into
training activities and, in most cases, the systems are used in the
same manner in which they are used for fleet training activities.
Amphibious warfare tests, when integrated with training activities or
conducted separately as full operational evaluations on existing
amphibious vessels and vehicles following maintenance, repair, or
modernization, may be conducted independently or in conjunction with
other amphibious ship and aircraft activities. Testing is performed to
ensure effective ship-to-shore coordination and transport of personnel,
equipment, and supplies. Tests may also be conducted periodically on
other systems, vessels, and aircraft intended for amphibious operations
to assess operability and to investigate efficacy of new technologies.
Anti-Submarine Warfare (ASW)
The mission of anti-submarine warfare is to locate, neutralize, and
defeat hostile submarine forces that threaten Navy forces. ASW is based
on the principle that surveillance and attack aircraft, ships, and
submarines all search for hostile submarines. These forces operate
together or independently to gain early warning and detection, and to
localize, track, target, and attack submarine threats. ASW training
addresses basic skills such as detection and classifying submarines, as
well as evaluating sounds to distinguish between enemy submarines and
friendly submarines, ships, and marine life. More advanced training
integrates the full spectrum of anti-submarine warfare from detecting
and tracking a submarine to attacking a target using either exercise
torpedoes (i.e., torpedoes that do not contain a warhead) or simulated
weapons. These integrated ASW exercises are conducted in coordinated,
at-sea training events involving submarines, ships, and aircraft.
Testing of ASW systems is conducted to develop new technologies and
assess weapon performance and operability with new systems and
platforms, such as unmanned systems. Testing uses ships, submarines,
and aircraft to demonstrate capabilities of torpedoes, missiles,
countermeasure systems, and underwater surveillance and communications
systems. Tests may be conducted as part of a large-scale fleet training
event involving submarines, ships, fixed-wing aircraft, and
helicopters. These integrated training events offer opportunities to
conduct research and acquisition activities and to train aircrew in the
use of new or newly enhanced systems during a largescale, complex
exercise.
Expeditionary Warfare
The mission of expeditionary warfare is to provide security and
surveillance in the littoral (at the shoreline), riparian (along a
river), or coastal environments. Expeditionary warfare is wide ranging
and includes defense of harbors, operation of remotely operated
vehicles, defense against swimmers, and boarding/seizure operations.
Expeditionary warfare training activities include underwater
construction team training, dive and salvage operations, and insertion/
extraction operations via air, surface, and subsurface platforms.
Mine Warfare (MIW)
The mission of MIW is to detect, classify, and avoid or neutralize
(disable) mines to protect Navy ships and submarines and to maintain
free access to ports and shipping lanes. MIW also includes offensive
mine laying to gain control of or deny the enemy access to sea space.
Naval mines can be laid by ships, submarines, or aircraft. MIW
neutralization training includes exercises in which ships, aircraft,
submarines, underwater vehicles, unmanned vehicles, or marine mammal
detection systems search for mine shapes. Personnel train to destroy or
disable mines by attaching underwater explosives to or near the mine or
using remotely operated vehicles to destroy the mine.
Testing and development of MIW systems is conducted to improve
sonar, laser, and magnetic detectors intended to hunt, locate, and
record the positions of mines for avoidance or subsequent
neutralization. MIW testing and development falls into two primary
categories: mine detection and classification, and mine countermeasure
and neutralization. Mine detection and classification testing involves
the use of air, surface, and subsurface vessels and uses sonar,
including towed and sidescan sonar, and unmanned vehicles to locate and
identify objects underwater. Mine detection and classification systems
are sometimes used in conjunction with a mine neutralization system.
Mine countermeasure and neutralization testing includes the use of air,
surface, and subsurface units to evaluate the effectiveness of tracking
devices, countermeasure and neutralization systems, and general purpose
bombs to neutralize mine threats. Most neutralization tests use mine
shapes, or non-explosive practice mines, to evaluate a new or enhanced
capability. For example, during a mine neutralization test, a
previously located mine is destroyed or rendered nonfunctional using a
helicopter or manned/unmanned surface vehicle based system that may
involve the deployment of a towed neutralization system.
A small percentage of MIW tests require the use of high-explosive
mines to evaluate and confirm the ability of the system to neutralize a
high-explosive mine under operational conditions. The majority of MIW
systems are deployed by ships, helicopters, and unmanned vehicles.
Tests may also be conducted in support of scientific research to
support these new technologies.

[[Page 10957]]

Surface Warfare (SUW)
The mission of SUW is to obtain control of sea space from which
naval forces may operate, and entails offensive action against other
surface, subsurface, and air targets while also defending against enemy
forces. In surface warfare, aircraft use cannons, air-launched cruise
missiles, or other precision-guided munitions; ships employ torpedoes,
naval guns, and surface-to-surface missiles; and submarines attack
surface ships using torpedoes or submarine-launched, anti-ship cruise
missiles. SUW includes surface-to-surface gunnery and missile
exercises, air-to-surface gunnery and missile exercises, and submarine
missile or torpedo launch events, and other munitions against surface
targets.
Testing of weapons used in SUW is conducted to develop new
technologies and to assess weapon performance and operability with new
systems and platforms, such as unmanned systems. Tests include various
air-to-surface guns and missiles, surface-to-surface guns and missiles,
and bombing tests. Testing events may be integrated into training
activities to test aircraft or aircraft systems in the delivery of
ordnance on a surface target. In most cases the tested systems are used
in the same manner in which they are used for fleet training
activities.
Other Warfare Activities
Naval forces conduct additional training and maintenance activities
which fall under other primary mission areas that are not listed above.
The AFTT DEIS/OEIS combines these training activities together in an
``other activities'' grouping for simplicity. These training activities
include, but are not limited to, sonar maintenance for ships and
submarines, submarine navigation and under ice certification, elevated
causeway system, oceanographic research, and surface ship object
detection. These activities include the use of various sonar systems,
impact pile driving/vibratory extraction, and air guns.

Overview of Major Training Activities and Exercises Within the AFTT
Study Area

A major training exercise is comprised of several ``unit level''
range exercises conducted by several units operating together while
commanded and controlled by a single commander. These exercises
typically employ an exercise scenario developed to train and evaluate
the strike group in naval tactical tasks. In a major training exercise,
most of the activities being directed and coordinated by the strike
group commander are identical in nature to the activities conducted
during individual, crew, and smaller unit level training events. In a
major training exercise, however, these disparate training tasks are
conducted in concert, rather than in isolation.
Some integrated or coordinated anti-submarine warfare exercises are
similar in that they are comprised of several unit level exercises but
are generally on a smaller scale than a major training exercise, are
shorter in duration, use fewer assets, and use fewer hours of hull-
mounted sonar per exercise. These coordinated exercises are conducted
under anti-submarine warfare. Three key factors used to identify and
group the exercises are the scale of the exercise, duration of the
exercise, and amount of hull-mounted sonar hours modeled/used for the
exercise.
NMFS considered the effects of all training exercises, not just
these major training exercises in this proposed rule.

Overview of Testing Activities Within the AFTT Study Area

The Navy's research and acquisition community engages in a broad
spectrum of testing activities in support of the fleet. These
activities include, but are not limited to, basic and applied
scientific research and technology development; testing, evaluation,
and maintenance of systems (e.g., missiles, radar, and sonar) and
platforms (e.g., surface ships, submarines, and aircraft); and
acquisition of systems and platforms to support Navy missions and give
a technological edge over adversaries. The individual commands within
the research and acquisition community are the Naval Air Systems
Command, Naval Sea Systems Command, and the Office of Naval Research.
Testing activities occur in response to emerging science or fleet
operational needs. For example, future Navy experiments to develop a
better understanding of ocean currents may be designed based on
advancements made by non-government researchers not yet published in
the scientific literature. Similarly, future but yet unknown Navy
operations within a specific geographic area may require development of
modified Navy assets to address local conditions. However, any evolving
testing activities that would be covered under this rule would be
expected to fall within the range of platforms, operations, sound
sources, and other equipment described in this rule and to have impacts
that fall within the range (i.e., nature and extent) of those covered
within the rule. For example, the Navy identifies ``bins'' of sound
sources to facilitate analyses--i.e., they identify frequency and
source level bounds to a bin and then analyze the worst case scenario
for that bin to understand the impacts of all of the sources that fall
within a bin. While the Navy might be aware that sound source e.g.,
XYZ1 will definitely be used this year, sound source e.g., XYZ2 might
evolve for testing three years from now, but if it falls within the
bounds of the same sound source bin, it has been analyzed and any
resulting take authorized (as long as the take accounting is done
correctly).
Some testing activities are similar to training activities
conducted by the fleet. For example, both the fleet and the research
and acquisition community fire torpedoes. While the firing of a torpedo
might look identical to an observer, the difference is in the purpose
of the firing. The fleet might fire the torpedo to practice the
procedures for such a firing, whereas the research and acquisition
community might be assessing a new torpedo guidance technology or
testing it to ensure the torpedo meets performance specifications and
operational requirements.
Naval Air Systems Command Testing Activities
Naval Air Systems Command testing activities generally fall in the
primary mission areas used by the fleets. Naval Air Systems Command
activities include, but are not limited to, the testing of new aircraft
platforms (e.g., the F-35 Joint Strike Fighter aircraft), weapons, and
systems (e.g., newly developed sonobuoys) that will ultimately be
integrated into fleet training activities. In addition to the testing
of new platforms, weapons, and systems, Naval Air Systems Command also
conducts lot acceptance testing of weapons and systems, such as
sonobuoys.
The majority of testing activities conducted by Naval Air Systems
Command are similar to fleet training activities, and many platforms
and systems currently being tested are already being used by the fleet
or will ultimately be integrated into fleet training activities.
However, some testing activities may be conducted in different
locations and in a different manner than similar fleet training
activities and, therefore, the analysis for those events and the
potential environmental effects may differ.
Naval Sea Systems Command Testing Activities
Naval Sea Systems Command activities are generally aligned with the

[[Page 10958]]

primary mission areas used by the fleets. Additional activities
include, but are not limited to, vessel evaluation, unmanned systems,
and other testing activities. In the Navy's rulemaking and LOA
application, pierside testing at Navy and contractor shipyards consists
only of system testing.
Testing activities are conducted throughout the life of a Navy
ship, from construction through deactivation from the fleet, to
verification of performance and mission capabilities. Activities
include pierside and at-sea testing of ship systems, including sonar,
acoustic countermeasures, radars, launch systems, weapons, unmanned
systems, and radio equipment; tests to determine how the ship performs
at sea (sea trials); development and operational test and evaluation
programs for new technologies and systems; and testing on all ships and
systems that have undergone overhaul or maintenance.
One ship of each new class (or major upgrade) of combat ships
constructed for the Navy typically undergoes an at-sea ship shock trial
to allow the Navy to assess the survivability of the hull and ship's
systems in a combat environment as well as the capability of the ship
to protect the crew.
Office of Naval Research Testing Activities
As the Department of the Navy's science and technology provider,
the Office of Naval Research provides technology solutions for Navy and
Marine Corps needs. The Office of Naval Research's mission is to plan,
foster, and encourage scientific research in recognition of its
paramount importance as related to the maintenance of future naval
power and the preservation of national security. The Office of Naval
Research manages the Navy's basic, applied, and advanced research to
foster transition from science and technology to higher levels of
research, development, test, and evaluation. The Office of Naval
Research is also a parent organization for the Naval Research
Laboratory, which operates as the Navy's corporate research laboratory
and conducts a broad multidisciplinary program of scientific research
and advanced technological development. Testing conducted by the Office
of Naval Research in the AFTT Study Area includes acoustic and
oceanographic research, large displacement unmanned underwater vehicle
(innovative naval prototype) research, and emerging mine countermeasure
technology research.
The proposed training and testing activities were evaluated to
identify specific components that could act as stressors (acoustic and
explosive) by having direct or indirect impacts on the environment.
This analysis included identification of the spatial variation of the
identified stressors.

Description of Acoustic and Explosive Stressors

The Navy uses a variety of sensors, platforms, weapons, and other
devices, including ones used to ensure the safety of Sailors and
Marines, to meet its mission. Training and testing with these systems
may introduce acoustic (sound) energy into the environment. The Navy's
rulemaking and LOA application describes specific components that could
act as stressors by having direct or indirect impacts on the
environment. This analysis included identification of the spatial
variation of the identified stressors. The following subsections
describe the acoustic and explosive stressors for biological resources
within the AFTT Study Area. Stressor/resource interactions that were
determined to have de minimus or no impacts (i.e., vessel, aircraft, or
weapons noise) were not carried forward for analysis in the Navy's
rulemaking and LOA application. NMFS has reviewed the Navy's analysis
and conclusions and finds them complete and supportable.

Acoustic Stressors

Acoustic stressors include acoustic signals emitted into the water
for a specific purpose, such as sonar, other transducers (devices that
convert energy from one form to another--in this case, to sound waves),
and airguns, as well as incidental sources of broadband sound produced
as a byproduct of impact pile driving and vibratory extraction.
Explosives also produce broadband sound but are characterized
separately from other acoustic sources due to their unique
characteristics. Characteristics of each of these sound sources are
described in the following sections.
In order to better organize and facilitate the analysis of
approximately 300 sources of underwater sound used for training and
testing by the Navy including sonars, other transducers, airguns, and
explosives, a series of source classifications, or source bins, were
developed.
Sonar and Other Transducers
Active sonar and other transducers emit non-impulsive sound waves
into the water to detect objects, safely navigate, and communicate.
Passive sonars differ from active sound sources in that they do not
emit acoustic signals; rather, they only receive acoustic information
about the environment, or listen. In the Navy's rulemaking and LOA
request, the terms sonar and other transducers are used to indicate
active sound sources unless otherwise specified.
The Navy employs a variety of sonars and other transducers to
obtain and transmit information about the undersea environment. Some
examples are mid-frequency hull-mounted sonars used to find and track
enemy submarines; high-frequency small object detection sonars used to
detect mines; high frequency underwater modems used to transfer data
over short ranges; and extremely high-frequency (>200 kilohertz [kHz])
Doppler sonars used for navigation, like those used on commercial and
private vessels. The characteristics of these sonars and other
transducers, such as source level, beam width, directivity, and
frequency, depend on the purpose of the source. Higher frequencies can
carry more information or provide more information about objects off
which they reflect, but attenuate more rapidly. Lower frequencies
attenuate less rapidly, so may detect objects over a longer distance,
but with less detail.
Propagation of sound produced underwater is highly dependent on
environmental characteristics such as bathymetry, bottom type, water
depth, temperature, and salinity. The sound received at a particular
location will be different than near the source due to the interaction
of many factors, including propagation loss; how the sound is
reflected, refracted, or scattered; the potential for reverberation;
and interference due to multi-path propagation. In addition, absorption
greatly affects the distance over which higher-frequency sounds
propagate. The effects of these factors are explained in Appendix D
(Acoustic and Explosive Concepts) of the AFTT DEIS/OEIS. Because of the
complexity of analyzing sound propagation in the ocean environment, the
Navy relies on acoustic models in its environmental analyses that
consider sound source characteristics and varying ocean conditions
across the AFTT Study Area.
The sound sources and platforms typically used in naval activities
analyzed in the Navy's rulemaking and LOA request are described in
Appendix A (Navy Activity Descriptions) of the AFTT DEIS/OEIS. Sonars
and other transducers used to obtain and transmit information
underwater during Navy training and testing activities generally fall
into several categories of use described below.

Anti-Submarine Warfare

Sonar used during ASW would impart the greatest amount of acoustic
energy of any category of sonar and other transducers analyzed in the
Navy's

[[Page 10959]]

rulemaking and LOA request. Types of sonars used to detect enemy
vessels include hull-mounted, towed, line array, sonobuoy, helicopter
dipping, and torpedo sonars. In addition, acoustic targets and decoys
(countermeasures) may be deployed to emulate the sound signatures of
vessels or repeat received signals.
Most ASW sonars are mid frequency (1-10 kHz) because mid-frequency
sound balances sufficient resolution to identify targets with distance
over which threats can be identified. However, some sources may use
higher or lower frequencies. Duty cycles can vary widely, from rarely
used to continuously active. For example, a submarine`s mission
revolves around its stealth; therefore, submarine sonar is used
infrequently because its use would also reveal a submarine's location.
ASW sonars can be wide-ranging in a search mode or highly directional
in a track mode.
Most ASW activities involving submarines or submarine targets would
occur in waters greater than 600 feet (ft) deep due to safety concerns
about running aground at shallower depths. Sonars used for ASW
activities would typically be used beyond 12 nautical miles (nmi) from
shore. Exceptions include use of dipping sonar by helicopters,
maintenance of systems while in port, and system checks while
transiting to or from port.

Mine Warfare, Small Object Detection, and Imaging

Sonars used to locate mines and other small objects, as well those
used in imaging (e.g., for hull inspections or imaging of the
seafloor), are typically high frequency or very high frequency. Higher
frequencies allow for greater resolution and, due to their greater
attenuation, are most effective over shorter distances. Mine detection
sonar can be deployed (towed or vessel hull-mounted) at variable depths
on moving platforms (ships, helicopters, or unmanned vehicles) to sweep
a suspected mined area. Hull-mounted anti-submarine sonars can also be
used in an object detection mode known as ``Kingfisher'' mode. Sonars
used for imaging are usually used in close proximity to the area of
interest, such as pointing downward near the seafloor.
Mine detection sonar use would be concentrated in areas where
practice mines are deployed, typically in water depths less than 200 ft
and at established training or testing minefields or temporary
minefields close to strategic ports and harbors. Kingfisher mode on
vessels is most likely to be used when transiting to and from port.
Sound sources used for imaging could be used throughout the AFTT Study
Area.

Navigation and Safety

Similar to commercial and private vessels, Navy vessels employ
navigational acoustic devices including speed logs, Doppler sonars for
ship positioning, and fathometers. These may be in use at any time for
safe vessel operation. These sources are typically highly directional
to obtain specific navigational data.

Communication

Sound sources used to transmit data (such as underwater modems),
provide location (pingers), or send a single brief release signal to
bottom-mounted devices (acoustic release) may be used throughout the
AFTT Study Area. These sources typically have low duty cycles and are
usually only used when it is desirable to send a detectable acoustic
message.

Classification of Sonar and Other Transducers

Sonars and other transducers are grouped into classes that share an
attribute, such as frequency range or purpose of use. Classes are
further sorted by bins based on the frequency or bandwidth; source
level; and, when warranted, the application in which the source would
be used, as follows:
[ssquf] Frequency of the non-impulsive acoustic source.
[cir] Low-frequency sources operate below 1 kHz
[cir] Mid-frequency sources operate at and 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

[ssquf] Sound pressure level of the non-impulsive source.

[cir] Greater than 160 decibels (dB) re 1 micro Pascal ([mu]Pa), but
less than 180 dB re 1 [mu]Pa
[cir] Equal to 180 dB re 1 [mu]Pa and up to 200 dB re 1 [mu]Pa
[cir] Greater than 200 dB re 1 [mu]Pa

[ssquf] Application in which the source would be used.

[cir] Sources with similar functions that have similar characteristics,
such as pulse length (duration of each pulse), beam pattern, and duty
cycle

The bins used for classifying active sonars and transducers that
are quantitatively analyzed in the AFTT Study Area are shown in Table 1
below. While general parameters or source characteristics are shown in
the table, actual source parameters are classified.

Table 1--Sonar and Transducers Quantitatively Analyzed
------------------------------------------------------------------------
Source class category Bin Description
------------------------------------------------------------------------
Low-Frequency (LF): Sources LF3 LF sources greater
that produce signals less than LF4 than 200 dB.
1 kHz. LF sources equal to
180 dB and up to 200
dB.
LF5 LF sources less than
180 dB.
LF6 LF sources greater
than 200 dB with long
pulse lengths.
Mid-Frequency (MF): Tactical MF1 Hull-mounted surface
and non-tactical sources that ship sonars (e.g., AN/
produce signals between 1-10 SQS-53C and AN/SQS-
kHz. 61).
MF1K Kingfisher mode
associated with MF1
sonars.
MF3 Hull-mounted submarine
sonars (e.g., AN/BQQ-
10).
MF4 Helicopter-deployed
dipping sonars (e.g.,
AN/AQS-22 and AN/AQS-
13).
MF5 Active acoustic
sonobuoys (e.g.,
DICASS).
MF6 Active underwater
sound signal devices
(e.g., MK84).
MF8 Active sources
(greater than 200 dB)
not otherwise binned.
MF9 Active sources (equal
to 180 dB and up to
200 dB) not otherwise
binned.
MF10 Active sources
(greater than 160 dB,
but less than 180 dB)
not otherwise binned.
MF11 Hull-mounted surface
ship sonars with an
active duty cycle
greater than 80%.

[[Page 10960]]

MF12 Towed array surface
ship sonars with an
active duty cycle
greater than 80%.
MF14 Oceanographic MF
sonar.
High-Frequency (HF): Tactical HF1 Hull-mounted submarine
and non-tactical sources that HF3 sonars (e.g., AN/BQQ-
produce signals between 10-100 10).
kHz. Other hull-mounted
submarine sonars
(classified).
HF4 Mine detection,
classification, and
neutralization sonar
(e.g., AN/SQS-20).
HF5 Active sources
(greater than 200 dB)
not otherwise binned.
HF6 Active sources (equal
to 180 dB and up to
200 dB) not otherwise
binned.
HF7 Active sources
(greater than 160 dB,
but less than 180 dB)
not otherwise binned.
HF8 Hull-mounted surface
ship sonars (e.g., AN/
SQS-61).
Very High-Frequency Sonars VHF1 VHF sources greater
(VHF): Non-tactical sources than 200 dB.
that produce signals between
100-200 kHz.
Anti-Submarine Warfare (ASW): ASW1 MF systems operating
Tactical sources (e.g., active ASW2 above 200 dB.
sonobuoys and acoustic counter- ASW3 MF Multistatic Active
measures systems) used during Coherent sonobuoy
ASW training and testing (e.g., AN/SSQ-125).
activities. MF towed active
acoustic
countermeasure
systems (e.g., AN/SLQ-
25).
ASW4 MF expendable active
acoustic device
countermeasures
(e.g., MK 3).
ASW5 MF sonobuoys with high
duty cycles.
Torpedoes (TORP): Source TORP1 Lightweight torpedo
classes associated with the (e.g., MK 46, MK 54,
active acoustic signals or Anti-Torpedo
produced by torpedoes. Torpedo).
TORP2 Heavyweight torpedo
(e.g., MK 48).
TORP3 Heavyweight torpedo
(e.g., MK 48).
Forward Looking Sonar (FLS): FLS2 HF sources with short
Forward or upward looking pulse lengths, narrow
object avoidance sonars used beam widths, and
for ship navigation and safety. focused beam
patterns.
Acoustic Modems (M): Systems M3 MF acoustic modems
used to transmit data through (greater than 190
the water. dB).
Swimmer Detection Sonars (SD): SD1-SD2 HF and VHF sources
Systems used to detect divers with short pulse
and sub-merged swimmers. lengths, used for the
detection of swimmers
and other objects for
the purpose of port
security.
Synthetic Aperture Sonars SAS1 MF SAS systems.
(SAS): Sonars in which active SAS2 HF SAS systems.
acoustic signals are post- SAS3 VHF SAS systems.
processed to form high-
resolution images of the
seafloor.
SAS4 MF to HF broadband
mine countermeasure
sonar.
Broadband Sound Sources (BB): BB1 MF to HF mine
Sonar systems with large BB2 countermeasure sonar.
frequency spectra, used for HF to VHF mine
various purposes. countermeasure sonar.
BB4 LF to MF oceanographic
source.
BB5 LF to MF oceanographic
source.
BB6 HF oceanographic
source.
BB7 LF oceanographic
source.
------------------------------------------------------------------------
Notes: ASW: Anti-submarine Warfare; BB: Broadband Sound Sources; FLS:
Forward Looking Sonar; HF: High-Frequency; LF: Low-Frequency; M:
Acoustic Modems; MF: Mid-Frequency; SAS: Synthetic Aperture Sonars;
SD: Swimmer Detection Sonars; TORP: Torpedoes; VHF: Very High-
Frequency; dB: decibels.

Airguns
Airguns are essentially stainless steel tubes charged with high-
pressure air via a compressor. An impulsive sound is generated when the
air is almost instantaneously released into the surrounding water.
Small airguns with capacities up to 60 cubic inches would be used
during testing activities in various offshore areas in the AFTT Study
Area, as well as near shore at Newport, RI.
Generated impulses would have short durations, typically a few
hundred milliseconds, with dominant frequencies below 1 kHz. The root-
mean-square sound pressure level (SPL) and peak pressure (SPL peak) at
a distance 1 meter (m) from the airgun would be approximately 215 dB re
1 [mu]Pa and 227 dB re 1 [mu]Pa, respectively, if operated at the full
capacity of 60 cubic inches. The size of the airgun chamber can be
adjusted, which would result in lower SPLs and sound exposure level
(SEL) per shot.
Pile Driving/Extraction
Impact pile driving and vibratory pile removal would occur during
construction of an Elevated Causeway System, a temporary pier that
allows the offloading of ships in areas without a permanent port.
Construction of the elevated causeway could occur in sandy shallow
water coastal areas at Joint Expeditionary Base Little Creek-Fort Story
in the Virginia Capes Range Complex or Marine Corps Base Camp Lejeune
in the Navy Cherry Point Range Complex.
Installing piles for elevated causeways would involve the use of an
impact hammer (impulsive) mechanism with both it and the pile held in
place by a crane. The hammer rests on the pile, and the assemblage is
then placed in position vertically on the beach or, when offshore,
positioned with the pile in the water and resting on the seafloor. When
the pile driving starts, the hammer part of the mechanism is raised up
and allowed to fall, transferring energy to the top of the pile. The
pile is thereby driven into the sediment by a repeated series of these
hammer blows. Each blow results in an impulsive sound emanating from
the length of the pile into the water column as well as from the bottom
of the pile through the sediment. Because the impact wave travels
through the steel

[[Page 10961]]

pile at speeds faster than the speed of sound in water, a steep-fronted
acoustic shock wave is formed in the water (Reinhall and Dahl, 2011)
(note this shock wave has very low peak pressure compared to a shock
wave from an explosive). An impact pile driver generally operates on
average 35 blows per minute.
Pile removal involves the use of vibratory extraction (non-
impulsive), during which the vibratory hammer is suspended from the
crane and attached to the top of a pile. The pile is then vibrated by
hydraulic motors rotating eccentric weights in the mechanism, causing a
rapid up and down vibration in the pile. This vibration causes the
sediment particles in contact with the pile to lose frictional grip on
the pile. The crane slowly lifts up on the vibratory driver and pile
until the pile is free of the sediment. Vibratory removal creates
continuous non-impulsive noise at low source levels for a short
duration.
The source levels of the noise produced by impact pile driving and
vibratory pile removal from an actual elevated causeway pile driving
and removal are shown in Table 2.

Table 2--Elevated Causeway System Pile Driving and Removal Underwater Sound Levels
----------------------------------------------------------------------------------------------------------------
Pile size and type Method Average sound levels at 10 m
----------------------------------------------------------------------------------------------------------------
24-in. Steel Pipe Pile....... Impact \1\...... 192 dB re 1 [mu]Pa SPL peak.
182 dB re 1 [micro]Pa2s SEL (single strike).
24-in. Steel Pipe Pile....... Vibratory 2..... 146 dB re 1 [mu]Pa SPL rms.
145 dB re 1 [micro]Pa2s SEL (per second of duration).
----------------------------------------------------------------------------------------------------------------
\1\ Illingworth and Rodkin (2016).
\2\ Illingworth and Rodkin (2015).
Notes: dB re 1 [micro]Pa: Decibels referenced to 1 micropascal; in.: inch; rms: root mean squared; SEL: Sound
Exposure Level; SPL: Sound Pressure Level.

In addition to underwater noise, the installation and removal of
piles also results in airborne noise in the environment. Impact pile
driving creates in-air impulsive sound about 100 dBA re 20 [mu]Pa at a
range of 15 m (Illingworth and Rodkin, 2016). During vibratory
extraction, the three aspects that generate airborne noise are the
crane, the power plant, and the vibratory extractor. The average sound
level recorded in air during vibratory extraction was about 85 dBA re
20 [mu]Pa (94 dB re 20 [mu]Pa) within a range of 10-15 m (Illingworth
and Rodkin, 2015).
The size of the pier and number of piles used in an Elevated
Causeway System (ELCAS) event is assumed to be no greater than 1,520 ft
long, requiring 119 supporting piles. Construction of the ELCAS would
involve intermittent impact pile driving over approximately 20 days.
Crews work 24 hours (hrs) a day and would drive approximately 6 piles
in that period. Each pile takes about 15 minutes to drive with time
taken between piles to reposition the driver. When training events that
use the ELCAS are complete, the structure would be removed using
vibratory methods over approximately 10 days. Crews would remove about
12 piles per 24-hour period, each taking about six minutes to remove.
Pile driving for ELCAS training would occur in shallower water, and
sound could be transmitted on direct paths through the water, be
reflected at the water surface or bottom, or travel through bottom
substrate. Soft substrates such as sand bottom at the proposed ELCAS
locations would absorb or attenuate the sound more readily than hard
substrates (rock), which may reflect the acoustic wave. Most acoustic
energy would be concentrated below 1,000 hertz (Hz) (Hildebrand, 2009).

Explosive Stressors

This section describes the characteristics of explosions during
naval training and testing. The activities analyzed in the Navy's
rulemaking and LOA application that use explosives are described in
Appendix A (Navy Activity Descriptions) of the AFTT DEIS/OEIS.
Explanations of the terminology and metrics used when describing
explosives in Navy's rulemaking and LOA application are in also in
Appendix D (Acoustic and Explosive Concepts) of the AFTT DEIS/OEIS.
The near-instantaneous rise from ambient to an extremely high peak
pressure is what makes an explosive shock wave potentially damaging.
Farther from an explosive, the peak pressures decay and the explosive
waves propagate as an impulsive, broadband sound. Several parameters
influence the effect of an explosive: The weight of the explosive
warhead, the type of explosive material, the boundaries and
characteristics of the propagation medium, and, in water, the
detonation depth. The net explosive weight, the explosive power of a
charge expressed as the equivalent weight of trinitrotoluene (TNT),
accounts for the first two parameters. The effects of these factors are
explained in Appendix D (Acoustic and Explosive Concepts) of the AFTT
DEIS/OEIS.
Explosions in Water
Explosive detonations during training and testing activities are
associated with high-explosive munitions, including, but not limited
to, bombs, missiles, rockets, naval gun shells, torpedoes, mines,
demolition charges, and explosive sonobuoys. Explosive detonations
during training and testing involving the use of high-explosive
munitions, including bombs, missiles, and naval gun shells could occur
near the water's surface. Explosive detonations associated with
torpedoes and explosive sonobuoys would occur in the water column;
mines and demolition charges could be detonated in the water column or
on the ocean bottom. Most detonations would occur in waters greater
than 200 ft in depth, and greater than 3 nmi from shore, although mine
warfare, demolition, and some testing detonations would occur in
shallow water close to shore.
In order to better organize and facilitate the analysis of
explosives used by the Navy during training and testing that could
detonate in water or at the water surface, explosive classification
bins were developed. The use of explosive classification bins provides
the same benefits as described for acoustic source classification bins
in Section 1.4.1 (Acoustic Stressors) of the Navy's rulemaking and LOA
application.
Explosives detonated in water are binned by net explosive weight.
The bins of explosives that are proposed for use in the AFTT Study Area
are shown in Table 3 below.

[[Page 10962]]

Table 3--Explosives Analyzed
----------------------------------------------------------------------------------------------------------------
Net explosive
Bin weight 1 (lb.) Example explosive source

----------------------------------------------------------------------------------------------------------------
E1............................ 0.1-0.25........ Medium-caliber projectile.
E2............................ >0.25-0.5........ Medium-caliber projectile.
E3............................ >0.5-2.5......... Large-caliber projectile.
E4............................ >2.5-5........... Mine neutralization charge.
E5............................ >5-10............ 5-inch projectile.
E6............................ >10-20........... Hellfire missile.
E7............................ >20-60........... Demo block/shaped charge.
E8............................ >60-100.......... Light-weight torpedo.
E9............................ >100-250......... 500 lb. bomb.
E10........................... >250-500......... Harpoon missile.
E11........................... >500-650......... 650 lb mine.
E12........................... >650-1,000....... 2,000 lb bomb.
E14 \2\....................... >1,741-3,625..... Line charge.
E16........................... >7,250-14,500.... Littoral Combat Ship full ship shock trial.
E17........................... >14,500-58,000... Aircraft carrier full ship shock trial.
----------------------------------------------------------------------------------------------------------------
\1\ Net Explosive Weight refers to the equivalent amount of TNT the actual weight of a munition may be larger
due to other components.
\2\ E14 is not modeled for protected species impacts in water because most energy is lost into the air or to the
bottom substrate due to detonation in very shallow water.

Propagation of explosive pressure waves in water is highly
dependent on environmental characteristics such as bathymetry, bottom
type, water depth, temperature, and salinity, which affect how the
pressure waves are reflected, refracted, or scattered; the potential
for reverberation; and interference due to multi-path propagation. In
addition, absorption greatly affects the distance over which higher
frequency components of explosive broadband noise can propagate.
Appendix D (Acoustic and Explosive Concepts) in the AFTT DEIS/OEIS
explains the characteristics of explosive detonations and how the above
factors affect the propagation of explosive energy in the water.
Because of the complexity of analyzing sound propagation in the ocean
environment, the Navy relies on acoustic models in its environmental
analyses that consider sound source characteristics and varying ocean
conditions across the AFTT Study Area.

Other Stressor--Vessel Strike

There is a very small chance that a vessel utilized in training or
testing activities could strike a large whale. Vessel strikes are not
specific to any particular training or testing activity, but rather a
limited, sporadic, and incidental result of Navy vessel movement within
the Study Area. Vessel strikes from commercial, recreational, and
military vessels are known to seriously injure and occasionally kill
cetaceans (Abramson et al., 2011; Berman-Kowalewski et al., 2010;
Calambokidis, 2012; Douglas et al., 2008; Laggner, 2009; Lammers et
al., 2003; Van der Hoop et al., 2012; Van der Hoop et al., 2013),
although reviews of the literature on ship strikes mainly involve
collisions between commercial vessels and whales (Jensen and Silber,
2003; Laist et al., 2001). Vessel speed, size, and mass are all
important factors in determining potential impacts of a vessel strike
to marine mammals (Conn & Silber, 2013; Gende et al., 2011; Silber et
al., 2010; Vanderlaan and Taggart, 2007; Wiley et al., 2016). For large
vessels, speed and angle of approach can influence the severity of a
strike. The average speed of large Navy ships ranges between 10 and 15
knots and submarines generally operate at speeds in the range of 8-13
knots, while a few specialized vessels can travel at faster speeds. By
comparison, this is slower than most commercial vessels where full
speed for a container ship is typically 24 knots (Bonney and Leach,
2010). Additional information on Navy vessel movements is provided in
Proposed Activities section. Large Navy vessels (greater than 18 m in
length) within the offshore areas of range complexes and testing ranges
operate differently from commercial vessels in ways that may reduce
potential whale collisions. Surface ships operated by or for the Navy
have multiple personnel assigned to stand watch at all times, when a
ship or surfaced submarine is moving through the water (underway). A
primary duty of personnel standing watch on surface ships is to detect
and report all objects and disturbances sighted in the water that may
indicate a threat to the vessel and its crew, such as debris, a
periscope, surfaced submarine, or surface disturbance. Per vessel
safety requirements, personnel standing watch also report any marine
mammals sighted in the path of the vessel as a standard collision
avoidance procedure. All vessels use extreme caution and proceed at a
safe speed so they can take proper and effective action to avoid a
collision with any sighted object or disturbance, and can be stopped
within a distance appropriate to the prevailing circumstances and
conditions. Vessel strikes have the potential to result in incidental
take from serious injury and/or mortality.

Proposed Activities

Proposed Training Activities

The Navy's proposed activities are presented and analyzed as a
representative year of training to account for the natural fluctuation
of training cycles and deployment schedules that generally influences
the maximum level of training from occurring year after year in any
five-year period. Both unit-level training and major training exercises
are adjusted to meet this representative year, as discussed below. For
the purposes of this application, the Navy assumes that some unit-level
training would be conducted using synthetic means (e.g., simulators).
Additionally, the Proposed Activity assumes that some unit-level active
sonar training will be accounted for within major training exercises.
The Optimized Fleet Response Plan and various training plans
identify the number and duration of training cycles that could occur
over a five-year period. The Proposed Activity considers fluctuations
in training cycles and deployment schedules that do not follow a
traditional annual calendar but instead are influenced by in-theater
demands and other external factors. Similar to unit-level training, the
Proposed Activity does not analyze a maximum number carrier strike
group Composite Training Unit Exercises (one

[[Page 10963]]

type of major exercise) every year, but instead assumes a maximum
number of exercises would occur during two years of any five-year
period and that a lower number of exercises would occur in the other
three years.
The training activities that the Navy proposes to conduct in the
AFTT Study Area are summarized in Table 4. The table is organized
according to primary mission areas and includes the activity name,
associated stressors applicable to this rulemaking and LOA request,
number of proposed activities and locations of those activities in the
AFTT Study Area. For further information regarding the primary platform
used (e.g., ship or aircraft type) see Appendix A (Navy Activity
Descriptions) of the AFTT DEIS/OEIS.

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Testing activities covered in this rulemaking and LOA request are
described in Table 5 through Table 7. The five-year Proposed Activity
presented here is based on the level of testing activities anticipated
to be conducted into the reasonably foreseeable future, with
adjustments that account for changes in the types and tempo (increases
or decreases) of testing activities to meet current and future military
readiness requirements. The Proposed Activity includes the testing of
new platforms, systems, and related equipment that will be introduced
after November 2018 and during the period of the rule. The majority of
testing activities that would be conducted under the Proposed Activity
are the same as or similar as those conducted currently or in the past.
The Proposed Activity includes the testing of some new systems using
new technologies and takes into account inherent uncertainties in this
type of testing.
Under the Proposed Activity, the Navy proposes a range of annual
levels of testing that reflects the fluctuations in testing programs by
recognizing that the maximum level of testing will not be conducted
each year, but further indicates a five-year maximum for each activity
that will not be exceeded. The Proposed Activity contains a more
realistic annual representation of activities, but includes years of a
higher maximum amount of testing to account for these fluctuations.
Naval Air Systems Command
Table 5 summarizes the proposed testing activities for the Naval
Air Systems Command analyzed within the AFTT Study Area.
Table 6 summarizes the proposed testing activities for the Naval
Sea Systems Command analyzed within the AFTT Study Area.

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Office of Naval Research
Table 7 summarizes the proposed testing activities for the Office
of Naval Research analyzed within the AFTT Study Area.
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Summary of Acoustic and Explosive Sources Analyzed for Training and
Testing

Table 8 through Table 11 show the acoustic source classes and
numbers, explosive source bins and numbers, airgun sources, and pile
driving and removal activities associated with Navy training and
testing activities in the AFTT Study Area that were analyzed in the
Navy's rulemaking and LOA application. Table 8 shows the acoustic
source classes (i.e., LF, MF, and HF) that could occur in any year
under the Proposed Activity for training and testing activities. Under
the Proposed Activity, acoustic source class use would vary annually,
consistent with the number of annual activities summarized above. The
five-year total for the Proposed Activity takes into account that
annual variability.

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Table 9 shows the number of airguns shots proposed in AFTT Study
Area for training and testing activities.

Table 9--Training and Testing Airgun Sources Quantitatively Analyzed in the AFTT Study Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
Training Testing
Source class category Bin Unit \1\ -------------------------------------------------------------------
Annual 5-year total Annual 5-year total
--------------------------------------------------------------------------------------------------------------------------------------------------------
Airguns (AG): Small underwater airguns AG C 0 0 604 3,020
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ C = count. One count (C) of AG is equivalent to 100 airgun firings.

Table 10 summarizes the impact pile driving and vibratory pile
removal activities that would occur during a 24-hour period. Annually,
for impact pile driving, the Navy will drive 119 piles, two times a
year for a total of 238 piles. Over the five-year period of the rule,
the Navy will drive a total of 1190 piles by impact pile driving.
Annually, for vibratory pile driving, the Navy will drive 119 piles,
two times a year for a total of 238 piles. Over the 5-year period of
the rule, the Navy will drive a total of 1190 piles by vibratory pile
driving.

Table 10--Summary of Pile Driving and Removal Activities per 24-Hour Period
----------------------------------------------------------------------------------------------------------------
Total
estimated time
Method Piles per 24- Time per pile of noise per
hour period (minutes) 24-hour period
(minutes)
----------------------------------------------------------------------------------------------------------------
Pile Driving (Impact)........................................... 6 15 90
Pile Removal (Vibratory)........................................ 12 6 72
----------------------------------------------------------------------------------------------------------------

Table 11 shows the number of in-water explosives that could be used
in any year under the Proposed Activity for training and testing
activities. Under the Proposed Activity, bin use would vary annually,
consistent with the number of annual activities summarized above. The
five-year total for the Proposed Activity takes into account that
annual variability.

Table 11--Explosive Source Bins Analyzed and Numbers Used During Training and Testing Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Training Testing
Bin Net explosive Example explosive source ---------------------------------------------------------------
weight \1\ (lb) Annual \2\ 5-year total Annual \2\ 5-year total
--------------------------------------------------------------------------------------------------------------------------------------------------------
E1.................................. 0.1-0.25 Medium-caliber projectile....... 7,700 38,500 17,840-26,840 116,200
E2.................................. >0.25-0.5 Medium-caliber projectile....... 210-214 1,062 0 0
E3.................................. >0.5-2.5 Large-caliber projectile........ 4,592 22,960 3,054-3,422 16,206
E4.................................. >2.5-5 Mine neutralization charge...... 127-133 653 746-800 3,784
E5.................................. >5-10 5-inch projectile............... 1,436 7,180 1,325 6,625
E6.................................. >10-20 Hellfire missile................ 602 3,010 28-48 200
E7.................................. >20-60 Demo block/shaped charge........ 4 20 0 0
E8.................................. >60-100 Light-weight torpedo............ 22 110 33 165
E9.................................. >100-250 500 lb bomb..................... 66 330 4 20
E10................................. >250-500 Harpoon missile................. 90 450 68-98 400
E11................................. >500-650 650 lb mine..................... 1 5 10 50
E12................................. >650-1,000 2,000 lb bomb................... 18 90 0 0
E16 \3\............................. >7,250-14,500 Littoral Combat Ship full ship 0 0 0-12 12
shock trial.

[[Page 10981]]

E17 \3\............................. >14,500-58,000 Aircraft carrier full ship shock 0 0 0-4 4
trial.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Net Explosive Weight refers to the equivalent amount of TNT the actual weight of a munition may be larger due to other components.
\2\ Expected annual use may vary per bin because the number of events may vary from year to year, as described in Section 1.5 (Proposed Activity).
\3\ Shock trials consist of four explosions each. In any given year there could be 0-3 small ship shock trials (E16) and 0-1 large ship shock trials
(E17). Over a 5-year period, there could be three small ship shock trials (E16) and one large ship shock trial (E17).

Vessel Movement

Vessels used as part of the Proposed Activity include ships,
submarines and boats ranging in size from small, 22 ft (7 m) rigid hull
inflatable boats to aircraft carriers with lengths up to 1,092 ft (333
m). Large Navy ships greater than 60 ft (18 m) generally operate at
speeds in the range of 10 to 15 knots for fuel conservation. Submarines
generally operate at speeds in the range of 8 to 13 knots in transits
and less than those speeds for certain tactical maneuvers. Small craft,
less than 60 ft (18 m) in length, have much more variable speeds
(dependent on the mission). For small craft types, sizes and speeds
vary during training and testing. Speeds generally range from 10 to 14
knots. While these speeds for large and small crafts are representative
of most events, some vessels need to temporarily operate outside of
these parameters.
The number of Navy vessels used in the AFTT Study Area varies based
on military training and testing requirements, deployment schedules,
annual budgets, and other unpredictable factors. Most training and
testing activities involve the use of vessels. These activities could
be widely dispersed throughout the AFTT Study Area, but would be
typically conducted near naval ports, piers, and range areas.
Activities involving vessel movements occur intermittently and are
variable in duration, ranging from a few hours up to two weeks. The
number of activities that include the use of vessels for testing events
is lower (around 10 percent) than the number of training activities.

Standard Operating Procedures

For training and testing to be effective, personnel must be able to
safely use their sensors and weapon systems as they are intended to be
used in a real-world situation and to their optimum capabilities. While
standard operating procedures are designed for the safety of personnel
and equipment and to ensure the success of training and testing
activities, their implementation often yields additional benefits on
environmental, socioeconomic, public health and safety, and cultural
resources.
Because standard operating procedures are essential to safety and
mission success, the Navy considers them to be part of the proposed
activities under the Proposed Activity, and has included them in the
environmental analysis. Standard operating procedures that are
recognized as providing a potential secondary benefit on marine mammals
during training and testing activities are noted below and discussed in
more detail within the AFTT Draft EIS/OEIS.

Vessel Safety
Weapons Firing Safety
Target Deployment Safety
Towed In-Water Device Safety
Pile Driving Safety
Coastal Zones

Standard operating procedures (which are implemented regardless of
their secondary benefits) are different from mitigation measures (which
are designed entirely for the purpose of avoiding or reducing potential
impacts on the environment.) Refer to Section 1.5.5 Standing Operating
Procedures of the Navy's rulemaking and LOA application for greater
detail.

Duration and Location

Training and testing activities would be conducted in the AFTT
Study Area throughout the year from 2018 through 2023 for the five-year
period covered by the regulations.
The AFTT Study Area (see Figure 1.1-1 of the Navy's rulemaking and
LOA application) includes areas of the western Atlantic Ocean along the
east coast of North America, portions of the Caribbean Sea, and the
Gulf of Mexico. The AFTT Study Area begins at the mean high tide line
along the U.S. coast and extends east to the 45-degree west longitude
line, north to the 65 degree north latitude line, and south to
approximately the 20-degree north latitude line. The AFTT Study Area
also includes Navy pierside locations, bays, harbors, and inland
waterways, and civilian ports where training and testing occurs. The
AFTT Study Area generally follows the Commander Task Force 80 area of
operations, covering approximately 2.6 million nmi\2\ of ocean area,
and includes designated Navy range complexes and associated operating
areas (OPAREAs) and special use airspace. While the AFTT Study Area
itself is very large, it is important to note that the vast majority of
Navy training and testing occurs in designated range complexes and
testing ranges.
A Navy range complex consists of geographic areas that encompasses
a water component (above and below the surface) and airspace, and may
encompass a land component where training and testing of military
platforms, tactics, munitions, explosives, and electronic warfare
systems occur. Range complexes include established operating areas and
special use airspace, which may be further divided to provide better
control of the area for safety reasons. Please refer to the regional
maps provided in the Navy's rulemaking and LOA application (Figure 2.2-
1 through Figure 2.2-3) for additional detail of the range complexes
and testing ranges. The range complexes and testing ranges are
described in the following sections.

Northeast Range Complex

The Northeast Range Complexes include the Boston Range Complex,
Narragansett Bay Range Complex, and Atlantic City Range Complex (see
Figure 2.2-1 in the Navy's rulemaking and LOA application). These range
complexes span 761 miles (mi) along the coast from Maine to New Jersey.
The Northeast Range Complexes include special use airspace with
associated warning areas and surface and subsurface sea space of the
Boston OPAREA, Narragansett Bay OPAREA, and Atlantic City OPAREA. The
Northeast Range Complexes include over 25,000 nmi\2\ of special use
airspace. The altitude at which aircraft may fly varies from just above
the surface to 60,000 ft, except for one specific warning area (W-107A)
in the Atlantic City Range Complex, which is

[[Page 10982]]

18,000 ft to unlimited altitudes. Six warning areas are located within
the Northeast Range Complexes. The Boston, Narragansett Bay, and
Atlantic City OPAREAs Encompass over 45,000 nmi\2\ of sea space and
undersea space. The Boston, Narragansett Bay, and Atlantic City OPAREAs
are offshore of the states of Maine, New Hampshire, Massachusetts,
Rhode Island, Connecticut, New York, and New Jersey. The OPAREAs of the
three complexes are outside 3 nmi but within 200 nmi from shore.

Naval Undersea Warfare Center Division, Newport Testing Range

The Naval Undersea Warfare Center Division, Newport Testing Range
includes the waters of Narragansett Bay, Rhode Island Sound, Block
Island Sound, Buzzards Bay, Vineyard Sound, and Long Island Sound (see
Figure 2.2-1 in the Navy's rulemaking and LOA application). A portion
of Naval Undersea Warfare Center Division, Newport Testing Range air
space is under restricted area R-4105A, known as No Man's Land Island,
and a minimal amount of testing occurs in this airspace. Three
restricted areas are located within the Naval Undersea Warfare Center
Division, Newport Testing Range:
[ssquf] Coddington Cove Restricted Area, 0.5 nmi\2\ adjacent to
Naval Undersea Warfare Center Division, Newport;
[ssquf] Narragansett Bay Restricted Area (6.1 nmi\2\ area
surrounding Gould Island) including the Hole Test Area and the North
Test Range; and
[ssquf] Rhode Island Sound Restricted Area, a rectangular box (27.2
nmi\2\) located in Rhode Island and Block Island Sounds.

Virginia Capes Range Complex

The Virginia Capes (VACAPES) Range Complex spans 270 mi. along the
coast from Delaware to North Carolina from the shoreline to 155 nmi
seaward (see Figure 2.2-1 in the Navy's rulemaking and LOA
application). The VACAPES Range Complex includes special use airspace
with associated warning and restricted areas, and surface and
subsurface sea space of the VACAPES OPAREA. The VACAPES Range Complex
also includes established mine warfare training areas located within
the lower Chesapeake Bay and off the coast of Virginia. The VACAPES
Range Complex includes over 28,000 nmi\2\ of special use airspace.
Flight altitudes range from surface to ceilings of 18,000 ft to
unlimited altitudes. Five warning areas are located within the VACAPES
Range Complex. Restricted airspace extends from the shoreline to
approximately the 3 nmi state territorial sea limit within the VACAPES
Range Complex, and is designated as R-6606. The VACAPES Range Complex
shore boundary roughly follows the shoreline from Delaware to North
Carolina; the seaward boundary extends 155 nmi into the Atlantic Ocean
proximate to Norfolk, Virginia. The VACAPES OPAREA encompasses over
27,000 nmi\2\ of sea space and undersea space. The VACAPES OPAREA is
offshore of the states of Delaware, Maryland, Virginia, and North
Carolina.

Navy Cherry Point Complex

The Navy Cherry Point Range Complex, off the coast of North
Carolina and South Carolina, encompasses the sea space from the
shoreline to 120 nmi seaward. The Navy Cherry Point Range Complex
includes special use airspace with associated warning areas and surface
and subsurface sea space of the Navy's Cherry Point OPAREA (see Figure
2.2-2 in the Navy's rulemaking and LOA application). The Navy Cherry
Point Range Complex is adjacent to the U.S. Marine Corps Cherry Point
and Camp Lejeune Range Complexes associated with Marine Corps Air
Station Cherry Point and Marine Corps Base Camp Lejeune. The Navy
Cherry Point Range Complex includes over 18,000 nmi\2\ of special use
airspace. The airspace varies from the surface to unlimited altitudes.
A single warning area is located within the Navy Cherry Point Range
Complex. The Navy Cherry Point Range Complex is roughly aligned with
the shoreline and extends out 120 nmi into the Atlantic Ocean. The Navy
Cherry Point OPAREA encompasses over 18,000 nmi\2\ of sea space and
undersea space.

Jacksonville Range Complex

The Jacksonville (JAX) Range Complex spans 520 mi along the coast
from North Carolina to Florida from the shoreline to 250 nmi seaward.
The JAX Range Complex includes special use airspace with associated
warning areas and surface and subsurface sea space of the Charleston
and JAX OPAREAs. The Undersea Warfare Training Range is located within
the JAX Range Complex (see Figure 2.2-2 in the Navy's rulemaking and
LOA application).

Naval Surface Warfare Center Carderock Division, South Florida Ocean
Measurement Facility Testing Range

The Naval Surface Warfare Center Carderock Division operates the
South Florida Ocean Measurement Facility Testing Range, an offshore
testing area in support of various Navy and non-Navy programs. The
South Florida Ocean Measurement Facility Testing Range is located
adjacent to the Port Everglades entrance channel in Fort Lauderdale,
Florida (see Figure 2.2-2 in the Navy's rulemaking and LOA
application). The test area at the South Florida Ocean Measurement
Facility Testing Range includes an extensive cable field located within
a restricted anchorage area and two designated submarine operating
areas. The South Florida Ocean Measurement Facility Testing Range does
not have associated special use airspace. The airspace adjacent to the
South Florida Ocean Measurement Facility Testing Range is managed by
the Fort Lauderdale International Airport. Air operations at the South
Florida Ocean Measurement Facility Testing Range are coordinated with
Fort Lauderdale International Airport by the air units involved in the
testing events. The South Florida Ocean Measurement Facility Testing
Range is divided into four subareas:
[ssquf] The Port Everglades Shallow Submarine Operating Area is a
120-nmi\2\ area that encompasses nearshore waters from the shoreline to
900 ft deep and 8 nmi offshore.
[ssquf] The Training Minefield is a 41-nmi\2\ area used for special
purpose surface ship and submarine testing where the test vessels are
restricted from maneuvering and require additional protection. This
Training Minefield encompasses waters from 60 to 600 ft deep and from 1
to 3 nmi offshore.
[ssquf] The Port Everglades Deep Submarine Operating Area is a 335-
nmi\2\ area that encompasses the offshore range from 900 to 2,500 ft in
depth and from 9 to 25 nmi offshore.
[ssquf] The Port Everglades Restricted Anchorage Area is an 11-
nmi\2\ restricted anchorage area ranging in depths from 60 to 600 ft
where the majority of the South Florida Ocean Measurement Facility
Testing Range cables run from offshore sensors to the shore facility
and where several permanent measurement arrays are used for vessel
signature acquisition.

Key West Range Complex

The Key West Range Complex lies off the southwestern coast of
mainland Florida and along the southern Florida Keys, extending seaward
into the Gulf of Mexico 150 nmi and south into the Straits of Florida
60 nmi. The Key West Range Complex includes special use airspace with
associated warning areas and surface and subsurface sea space of the
Key West OPAREA (see Figure 2.2-3 in the Navy's rulemaking and LOA
application). The Key West Range Complex includes over 20,000 nmi\2\ of

[[Page 10983]]

special use airspace. Flight altitudes range from the surface to
unlimited altitudes. Eight warning areas, Bonefish Air Traffic Control
Assigned Airspace, and Tortugas Military Operating Area are located
within the Key West Range Complex. The Key West OPAREA is over 8,000
nmi\2\ of sea space and undersea space south of Key West, Florida.

Naval Surface Warfare Center, Panama City Division Testing Range

The Naval Surface Warfare Center, Panama City Division Testing
Range is located off the panhandle of Florida and Alabama, extending
from the shoreline to 120 nmi seaward, and includes St. Andrew Bay.
Naval Surface Warfare Center, Panama City Division Testing Range also
includes special use airspace and offshore surface and subsurface
waters of offshore OPAREAs (see Figure 2.2-3 of the Navy's rulemaking
and LOA application). Special use airspace associated with Naval
Surface Warfare Center, Panama City Division Testing Range includes
three warning areas. The Naval Surface Warfare Center, Panama City
Division Testing Range includes the waters of St. Andrew Bay and the
sea space within the Gulf of Mexico from the mean high tide line to 120
nmi offshore. The Panama City OPAREA covers just over 3,000 nmi\2\ of
sea space and lies off the coast of the Florida panhandle. The
Pensacola OPAREA lies off the coast of Alabama and Florida west of the
Panama City OPAREA and totals just under 5,000 nmi\2\.

Gulf of Mexico Range Complex

Unlike most of the range complexes previously described, the Gulf
of Mexico (GOMEX) Range Complex includes geographically separated areas
throughout the Gulf of Mexico. The GOMEX Range Complex includes special
use airspace with associated warning areas and restricted airspace and
surface and subsurface sea space of the Panama City, Pensacola, New
Orleans, and Corpus Christi OPAREAs (see Figure 2.2-3 of the Navy's
rulemaking and LOA application). The GOMEX Range Complex includes
approximately 20,000 nmi\2\ of special use airspace. Flight altitudes
range from the surface to unlimited. Six warning areas are located
within the GOMEX Range Complex. Restricted airspace associated with the
Pensacola OPAREA, designated R-2908, extends from the shoreline to
approximately 3 nmi offshore. The GOMEX Range Complex encompasses
approximately 17,000 nmi\2\ of sea and undersea space and includes 285
nmi of coastline. The OPAREAs span from the eastern shores of Texas to
the western panhandle of Florida. They are described as follows:
[ssquf] Panama City OPAREA lies off the coast of the Florida
panhandle and totals approximately 3,000 nmi\2\;
[ssquf] Pensacola OPAREA lies off the coast of Florida west of the
Panama City OPAREA and totals approximately 4,900 nmi\2\;
[ssquf] New Orleans OPAREA lies off the coast of Louisiana and
totals approximately 2,600 nmi\2\; and
[ssquf] Corpus Christi OPAREA lies off the coast of Texas and
totals approximately 6,900 nmi\2\.

Inshore Locations

Although within the boundaries of the Range Complexes and testing
ranges detailed above, various inshore locations including piers, bays,
and civilian ports are identified in Figure 2.2-1 through Figure 2.2-3
of the Navy's rulemaking and LOA application.
Pierside locations include channels and transit routes in ports and
facilities associated with the following Navy ports and naval
shipyards:
[ssquf] Portsmouth Naval Shipyard, Kittery, Maine;
[ssquf] Naval Submarine Base New London, Groton, Connecticut;
[ssquf] Naval Station Norfolk, Norfolk, Virginia;
[ssquf] Joint Expeditionary Base Little Creek-Fort Story, Virginia
Beach, Virginia;
[ssquf] Norfolk Naval Shipyard, Portsmouth, Virginia;
[ssquf] Naval Submarine Base Kings Bay, Kings Bay, Georgia;
[ssquf] Naval Station Mayport, Jacksonville, Florida; and
[ssquf] Port Canaveral, Cape Canaveral, Florida.
Commercial shipbuilding facilities in the following cities are also
in the AFTT Study Area:
[ssquf] Bath, Maine;
[ssquf] Groton, Connecticut;
[ssquf] Newport News, Virginia;
[ssquf] Mobile, Alabama; and
[ssquf] Pascagoula, Mississippi.
Bays, Harbors, and Inland Waterways
Inland waterways used for training and testing activities include:
[ssquf] Narragansett Bay Range Complex/Naval Undersea Warfare
Center Division, Newport Testing Range: Thames River, Narragansett Bay;
[ssquf] VACAPES Complex: James River and tributaries, Broad Bay,
York River, Lower Chesapeake Bay;
[ssquf] JAX Range Complex: southeast Kings Bay, Cooper River, St.
Johns River; and
[ssquf] GOMEX Range Complex/Naval Surface Warfare Center, Panama
City Division (including Naval Surface Warfare Center, Panama City
Division): St. Andrew Bay Civilian Ports.
Civilian ports included for civilian port defense training events
are listed in Section A.2.7.3 of Appendix A (Navy Activity
Descriptions) of the Navy's AFTT DEIS/OEIS and include:
[ssquf] Boston, Massachusetts;
[ssquf] Earle, New Jersey;
[ssquf] Delaware Bay, Delaware;
[ssquf] Hampton Roads, Virginia;
[ssquf] Morehead City, North Carolina;
[ssquf] Wilmington, North Carolina;
[ssquf] Savannah, Georgia;
[ssquf] Kings Bay, Georgia;
[ssquf] Mayport, Florida;
[ssquf] Port Canaveral, Florida;
[ssquf] Tampa, Florida;
[ssquf] Beaumont, Texas; and
[ssquf] Corpus Christi, Texas.

Description of Marine Mammals and Their Habitat in the Area of the
Specified Activities

Marine mammal species that have the potential to occur in the AFTT
Study Area and their associated stocks are presented in Table 12 along
with an abundance estimate, an associated coefficient of variation
value, and best/minimum abundance estimates. Some marine mammal
species, such as manatees, are not managed by NMFS, but by the U.S.
Fish and Wildlife Service and therefore not discussed below. The Navy
proposes to take individuals of 39 marine mammal species by Level A and
B harassment incidental to training and testing activities from the use
of sonar and other transducers, in-water detonations, airguns, and
impact pile driving/vibratory extraction. In addition, the Navy is
requesting nine mortalities of four marine mammal stocks during ship
shock trials, and three takes by serious injury or mortality from
vessel strikes over the five-year period. One marine mammal species,
the North Atlantic right whale (Eubalaena glacialis), has critical
habitat designated under the Endangered Species Act in the AFTT Study
Area (described below).
Information on the status, distribution, abundance, and
vocalizations of marine mammal species in the AFTT Study Area may be
found in Chapter 4 Affected Species Status and Distribution of the
Navy's rulemaking and LOA application. Additional information on the
general biology and ecology of marine mammals are included in the AFTT
DEIS/OEIS. In addition, NMFS annually publishes Stock Assessment
Reports (SARs) for all marine mammals in U.S. Exclusive Economic Zone
(EEZ) waters, including stocks that occur within the AFTT

[[Page 10984]]

Study Area--U.S. Atlantic and Gulf of Mexico Marine Mammal Stock
Assessment Reports (Hayes et al., 2017) (see https://www.fisheries.noaa.gov/resource/document/us-atlantic-and-gulf-mexico-marine-mammal-stock-assessments-2016).
The species carried forward for analysis are those likely to be
found in the AFTT Study Area based on the most recent data available,
and do not include stocks or species that may have once inhabited or
transited the area but have not been sighted in recent years and
therefore are extremely unlikely to occur in the AFTT Study Area (e.g.,
species which were extirpated because of factors such as nineteenth and
twentieth century commercial exploitation).
The species not carried forward for analysis are the bowhead whale,
beluga whale, and narwhal as these would be considered extralimital
species. Bowhead whales are likely to be found only in the Labrador
Current open ocean area, but in 2012 and 2014, the same bowhead whale
was observed in Cape Cod Bay, which represents the southernmost record
of this species in the western North Atlantic. In June 2014, a beluga
whale was observed in several bays and inlets of Rhode Island and
Massachusetts (Swaintek, 2014). This sighting likely represents an
extralimital beluga whale occurrence in the Northeast United States
Continental Shelf Large Marine Ecosystem. There is no stock of narwhal
that occurs in the U.S. EEZ in the Atlantic Ocean; however, populations
from Hudson Strait and Davis Strait may extend into the AFTT Study Area
at its northwest extreme. However, narwhals prefer cold Arctic waters
those wintering in Hudson Strait occur in smaller numbers. For these
reasons, the likelihood of any Navy activities encountering and having
any effect on any of these three species is so slight as to be
unlikely; therefore, these species do not require further analysis.

Table 12--Marine Mammals With the Potential To Occur Within the AFTT Study Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
Occurrence in AFTT study area \5\
Scientific name ESA/MMPA status Stock abundance --------------------------------------------------
Common name \1\ Stock \2\ \3\ \4\ best/minimum Large marine
population Open ocean ecosystems Inland waters
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Cetacea
--------------------------------------------------------------------------------------------------------------------------------------------------------
Suborder Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenidae (right whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bowhead whale................ Balaena Eastern Canada- Endangered, 7,660 (4,500- Labrador Newfoundland- NA.
mysticetus. West Greenland. strategic, 11,100) \6\. Current. Labrador
depleted. Shelf, West
Greenland
Shelf,
Northeast U.S.
Continental
Shelf.
North Atlantic right whale... Eubalaena Western......... Endangered, 440 (0)/440..... Gulf Stream, Southeast U.S. NA.
glacialis. strategic, Labrador Continental
depleted. Current, North Shelf,
Atlantic Gyre. Northeast U.S.
Continental
Shelf, Scotian
Shelf,
Newfoundland-
Labrador
Shelf, Gulf of
Mexico
(extralimital).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenopteridae (rorquals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale................... Balaenoptera Western North Endangered, Unknown/440 \11\ Gulf Stream, Northeast U.S. NA.
musculus. Atlantic (Gulf strategic, North Atlantic Continental
of St. depleted. Gyre, Labrador Shelf, Scotian
Lawrence). Current. Shelf,
Newfoundland-
Labrador
Shelf,
Southeast U.S.
Continental
Shelf,
Caribbean Sea,
and Gulf of
Mexico
(strandings
only).
Bryde's whale................ Balaenoptera Northern Gulf of Proposed 33 (1.07)/16.... Gulf Stream, Gulf of Mexico. NA.
brydei/edeni. Mexico. Endangered, North Atlantic
Strategic. Gyre.
Fin whale.................... Balaenoptera Western North Endangered, 1,618 (0.33)/ Gulf Stream, Caribbean Sea, NA.
physalus. Atlantic. strategic, 1,234. North Atlantic Gulf of
depleted. Gyre, Labrador Mexico,
Current. Southeast U.S.
Continental
Shelf,
Northeast U.S.
Continental
Shelf, Scotian
Shelf,
Newfoundland-
Labrador Shelf.
West Greenland.. Endangered, 4,468 (1,343- Labrador West Greenland NA.
strategic, 14,871) \9\. Current. Shelf.
depleted.

[[Page 10985]]

Gulf of St. Endangered, 328 (306-350) ............... Newfoundland- NA.
Lawrence. strategic, \10\. Labrador
depleted. Shelf, Scotian
Shelf.
Humpback whale............... Megaptera Gulf of Maine... Strategic....... 823 (0)/823..... Gulf Stream, Gulf of Mexico, NA.
novaeangliae. North Atlantic Caribbean Sea,
Gyre, Labrador Southeast U.S.
Current. Continental
Shelf,
Northeast U.S.
Continental
Shelf, Scotian
Shelf,
Newfoundland-
Labrador Shelf.
Minke whale.................. Balaenoptera Canadian Eastern NA.............. 2,591 (0.81)/ Gulf Stream, Caribbean Sea, NA.
acutorostrata. Coastal. 1,425. North Atlantic Southeast U.S.
Gyre, Labrador Continental
Current. Shelf,
Northeast U.S.
Continental
Shelf, Scotian
Shelf,
Newfoundland-
Labrador Shelf.
West Greenland NA.............. 16,609 (7,172- Labrador West Greenland NA.
\7\. 38,461)/NA \7\. Current. Shelf.
Sei whale.................... Balaenoptera Nova Scotia..... Endangered, 357 (0.52)/236.. Gulf Stream, Gulf of Mexico, NA.
borealis. strategic, North Atlantic Caribbean Sea,
depleted. Gyre. Southeast
Northeast U.S.
Continental
Shelf, Scotian
Shelf,
Newfoundland-
Labrador Shelf.
Labrador Sea.... Endangered, Unknown \8\..... Labrador Newfoundland- NA.
strategic, Current. Labrador
depleted. Shelf, West
Greenland
Shelf.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Physeteridae (sperm whale)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Suborder Odontoceti (toothed whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale.................. Physeter North Atlantic.. Endangered, 2,288 (0.28)/ Gulf Stream, Southeast U.S. NA.
macrocephalus. strategic, 1,815. North Atlantic Continental
depleted. Gyre, Labrador Shelf,
Current. Northeast U.S.
Continental
Shelf, Scotian
Shelf,
Newfoundland-
Labrador
Shelf,
Caribbean Sea.
Northern Gulf of Endangered, 763 (0.38)/560.. NA............. Gulf of Mexico. NA.
Mexico. strategic,
depleted.
Puerto Rico and Endangered, Unknown......... North Atlantic Caribbean Sea.. NA.
U.S. Virgin strategic, Gyre.
Islands. depleted.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Kogiidae (sperm whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pygmy and dwarf sperm whales. Kogia breviceps Western North NA.............. 3,785 (0.47)/ Gulf Stream, Southeast U.S. NA.
and Kogia sima. Atlantic. 2,598 \12\. North Atlantic Continental
Gyre. Shelf,
Northeast U.S.
Continental
Shelf, Scotian
Shelf,
Newfoundland-
Labrador
Shelf,
Caribbean Sea.
Northern Gulf of NA.............. 186 (1.04)/90 NA............. Gulf of Mexico, NA.
Mexico. \12\. Caribbean Sea.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Monodontidae (beluga whale and narwhal)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Beluga whale................. Delphinapterus Eastern High NA.............. 21,213 (10,985- Labrador West Greenland NA.
leucas. Arctic/Baffin 32,619) \13\. Current. Shelf.
Bay \13\.
West Greenland NA.............. 10,595 (4.904- NA............. West Greenland NA.
\14\. 24,650) \14\. Shelf.

[[Page 10986]]

Narwhal...................... Monodon NA \15\......... NA.............. NA \15\......... NA............. Newfoundland- NA.
monoceros. Labrador
Shelf, West
Greenland
Shelf.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Ziphiidae (beaked whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blainville's beaked whale.... Mesoplodon Western North NA.............. 7,092 (0.54)/ Gulf Stream, Southeast U.S. NA.
densirostris. Atlantic \16\. 4,632 \17\. North Atlantic Continental
Gyre, Labrador Shelf,
Current. Northeast U.S.
Continental
Shelf, Scotian
Shelf,
Newfoundland-
Labrador Shelf.
Northern Gulf of NA.............. 149 (0.91)/77 NA............. Gulf of Mexico, NA.
Mexico. \18\. Caribbean Sea.
Cuvier's beaked whale........ Ziphius Western North NA.............. 6,532 (0.32)/ Gulf Stream, Southeast U.S. NA.
cavirostris. Atlantic \16\. 5,021. North Atlantic Continental
Gyre. Shelf,
Northeast U.S.
Continental
Shelf, Scotian
Shelf,
Newfoundland-
Labrador Shelf.
Northern Gulf of NA.............. 74 (1.04)/36.... NA............. Gulf of Mexico, NA.
Mexico \16\. Caribbean Sea.
Puerto Rico and Strategic....... Unknown......... NA............. Caribbean Sea.. NA.
U.S. Virgin
Islands.
Gervais' beaked whale........ Mesoplodon Western North NA.............. 7,092 (0.54)/ Gulf Stream, Southeast U.S. NA.
europaeus. Atlantic \16\. 4,632 \17\. North Atlantic Continental
Gyre. Shelf,
Northeast
United States
Continental
Shelf.
Northern Gulf of NA.............. 149 (0.91)/77 Gulf Stream, Gulf of Mexico, NA.
Mexico \16\. \18\. North Atlantic Caribbean Sea.
Gyre.
Northern bottlenose whale.... Hyperoodon Western North NA.............. Unknown......... Gulf Stream, Northeast U.S. NA.
ampullatus. Atlantic. North Atlantic Continental
Gyre, Labrador Shelf, Scotian
Current. Shelf,
Newfoundland-
Labrador Shelf.
Sowerby's beaked whale....... Mesoplodon Western North NA.............. 7,092 (0.54)/ Gulf Stream, Northeast U.S. NA.
bidens. Atlantic \16\. 4,632 \17\. North Atlantic Continental
Gyre. Shelf, Scotian
Shelf,
Newfoundland-
Labrador Shelf.
True's beaked whale.......... Mesoplodon mirus Western North NA.............. 7,092 (0.54)/ Gulf Stream, Southeast U.S. NA.
Atlantic \16\. 4,632 \17\. North Atlantic Continental
Gyre. Shelf,
Northeast U.S.
Continental
Shelf, Scotian
Shelf,
Newfoundland-
Labrador Shelf.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae (dolphins)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Atlantic spotted dolphin..... Stenella Western North NA.............. 44,715 (0.43)/ Gulf Stream.... Southeast U.S. NA.
frontalis. Atlantic \16\. 31,610. Continental
Shelf,
Northeast U.S.
Continental
Shelf.
Northern Gulf of NA.............. Unknown......... NA............. Gulf of Mexico, NA.
Mexico. Caribbean Sea.
Puerto Rico and Strategic....... Unknown......... NA............. Caribbean Sea.. NA.
U.S. Virgin
Islands.
Atlantic white-sided dolphin. Lagenorhynchus Western North NA.............. 48,819 (0.61)/ Gulf Steam, Northeast U.S. NA.
acutus. Atlantic. 30,403. Labrador Continental
Current. Shelf, Scotian
Shelf,
Newfoundland-
Labrador Shelf.

[[Page 10987]]

Clymene dolphin.............. Stenella clymene Western North NA.............. Unknown......... Gulf Stream.... Southeast U.S. NA.
Atlantic \16\. Continental
Shelf,
Northeast U.S.
Continental
Shelf.
Northern Gulf of NA.............. 129 (1.0)/64.... NA............. Gulf of Mexico, NA.
Mexico \16\. Caribbean Sea.
Common bottlenose dolphin.... Tursiops Western North Strategic, 77,532 (0.40)/ Gulf Stream, Southeast U.S. NA.
truncatus. Atlantic depleted. 56,053. North Atlantic Continental
Offshore \19\. Gyre. Shelf,
Northeast U.S.
Continental
Shelf, Scotian
Shelf.
Western North NA.............. 11,548 (0.36)/ NA............. Southeast U.S. Long Island
Atlantic 8,620. Continental Sound, Sandy
Northern Shelf, Hook Bay,
Migratory Northeast U.S. Lower
Coastal \20\. Continental Chesapeake
Shelf. Bay, James
River,
Elizabeth
River.
Western North Strategic, 9,173 (0.46)/ NA............. Southeast U.S. Lower
Atlantic depleted. 6,326. Continental Chesapeake
Southern Shelf. Bay, James
Migratory River,
Coastal \20\. Elizabeth
River,
Beaufort
Inlet, Cape
Fear River,
Kings Bay, St.
Johns River.
Western North Strategic, 4,377 (0.43)/ NA............. Southeast U.S. Kings Bay, St.
Atlantic South depleted. 3,097. Continental Johns River.
Carolina/ Shelf.
Georgia Coastal
\20\.
Northern North Strategic....... 823 (0.06)/782.. NA............. Southeast U.S. Beaufort Inlet,
Carolina Continental Cape Fear
Estuarine Shelf, River.
System \20\. Northeast U.S.
Continental
Shelf.
Southern North Strategic....... Unknown......... NA............. Southeast U.S. Beaufort Inlet,
Carolina Continental Cape Fear
Estuarine Shelf. River
System \20\.
Northern South Strategic....... Unknown......... NA............. Southeast U.S. NA.
Carolina Continental
Estuarine Shelf.
System \20\.
Charleston Strategic....... Unknown......... NA............. Southeast U.S. NA.
Estuarine Continental
System \20\. Shelf.
Common bottlenose dolphin Tursiops Northern Georgia/ Strategic....... Unknown......... NA............. Southeast U.S. NA.
(continued). truncatus. Southern South Continental
Carolina Shelf.
Estuarine
System \20\.
Central Georgia Strategic....... 192 (0.04)/185.. NA............. Southeast U.S. NA.
Estuarine Continental
System \20\. Shelf.
Southern Georgia Strategic....... 194 (0.05)/185.. NA............. Southeast U.S. Kings Bay, St.
Estuarine Continental Johns River.
System \20\. Shelf.
Western North Strategic, 1,219 (0.67)/730 NA............. Southeast U.S. Kings Bay, St.
Atlantic depleted. Continental Johns River.
Northern Shelf.
Florida Coastal
\20\.
Jacksonville Strategic....... Unknown......... NA............. Southeast U.S. Kings Bay, St.
Estuarine Continental Johns River.
System \20\. Shelf.
Western North Strategic, 4,895 (0.71)/ NA............. Southeast U.S. Port Canaveral.
Atlantic depleted. 2,851. Continental
Central Florida Shelf.
Coastal \20\.
Indian River Strategic....... Unknown......... NA............. Southeast U.S. Port Canaveral.
Lagoon Continental
Estuarine Shelf.
System \20\.
Biscayne Bay Strategic....... Unknown......... NA............. Southeast U.S. NA.
\16\. Continental
Shelf.
Florida Bay \16\ NA.............. Unknown......... NA............. Gulf of Mexico. NA.
Northern Gulf of NA.............. 51,192 (0.10)/ NA............. Gulf of Mexico. NA.
Mexico 46,926.
Continental
Shelf \20\.

[[Page 10988]]

Gulf of Mexico NA.............. 12,388 (0.13)/ NA............. Gulf of Mexico. NA.
Eastern Coastal 11,110.
\20\.
Gulf of Mexico NA.............. 7,185 (0.21)/ NA............. Gulf of Mexico. St. Andrew Bay,
Northern 6,044. Pascagoula
Coastal \20\. River.
Gulf of Mexico NA.............. 20,161 (0.17)/ NA............. Gulf of Mexico. Corpus Christi
Western Coastal 17,491. Bay, Galveston
\20\. Bay.
Northern Gulf of NA.............. 5,806 (0.39)/ NA............. Gulf of Mexico. NA.
Mexico Oceanic 4,230.
\20\.
Northern Gulf of Strategic....... Unknown......... NA............. Gulf of Mexico. St. Andrew Bay,
Mexico Bay, Pascagoula
Sound, and River, Sabine
Estuaries \21\. Lake, Corpus
Christi Bay,
and Galveston
Bay.
Barataria Bay Strategic....... Unknown......... NA............. Gulf of Mexico. NA.
Estuarine
System \20\.
Mississippi Strategic....... 901 (0.63)/551.. NA............. Gulf of Mexico. NA.
Sound, Lake
Borgne, Bay
Boudreau \20\.
St. Joseph Bay Strategic....... 152 (0.08)/ NA............. Gulf of Mexico. NA.
\20\. Unknown.
Choctawhatchee Strategic....... 179 (0.04)/ NA............. Gulf of Mexico. NA.
Bay \20\. Unknown.
Puerto Rico and Strategic....... Unknown......... NA............. Caribbean Sea.. NA.
U.S. Virgin
Islands.
False killer whale........... Pseudorca Western North Strategic....... 442 (1.06)/212.. NA............. Southeast U.S. NA.
crassidens. Atlantic \22\. Continental
Shelf,
Northeast U.S.
Continental
Shelf.
Northern Gulf of NA.............. Unknown......... NA............. Gulf of Mexico, NA.
Mexico \16\. Caribbean Sea.
Fraser's dolphin............. Lagenodelphis Western North NA.............. Unknown......... Gulf Stream.... Northeast U.S. NA.
hosei. Atlantic \23\. Continental
Shelf,
Southeast U.S.
Continental
Shelf.
Northern Gulf of NA.............. Unknown......... NA............. Gulf of Mexico, NA.
Mexico \16\. Caribbean Sea.
Killer Whale................. Orcinus orca.... Western North NA.............. Unknown......... Gulf Stream, Southeast U.S. NA.
Atlantic \22\. North Atlantic Continental
Gyre, Labrador Shelf,
Current. Northeast
United States
Continental
Shelf, Scotian
Shelf,
Newfoundland--
Labrador Shelf.
Northern Gulf of NA.............. 28 (1.02)/14.... NA............. Gulf of Mexico, NA.
Mexico \16\. Caribbean Sea.
Long-finned pilot whale...... Globicephala Western North Strategic....... 5,636 (0.63)/ Gulf Stream.... Northeast U.S. NA.
melas. Atlantic. 3,464. Continental
Shelf, Scotian
Shelf,
Newfoundland-
Labrador Shelf.
Melon-headed Whale........... Peponocephala Western North NA.............. Unknown......... Gulf Stream, Southeast U.S. NA.
electra. Atlantic \23\. North Atlantic Continental
Gyre. Shelf.
Northern Gulf of NA.............. 2,235 (0.75)/ NA............. Gulf of Mexico, NA.
Mexico \16\. 1,274. Caribbean Sea.
Pantropical spotted-dolphin.. Stenella Western North NA.............. 3,333 (0.91)/ Gulf Stream.... Southeast U.S. NA.
attenuate. Atlantic \16\. 1,733. Continental
Shelf,
Northeast U.S.
Continental
Shelf.
Northern Gulf of NA.............. 50,880 (0.27)/ NA............. Gulf of Mexico, NA.
Mexico \22\. 40,699. Caribbean Sea.
Pygmy Killer Whales.......... Feresa attenuata Western North NA.............. Unknown......... Gulf Stream, Southeast U.S. NA.
Atlantic \16\. North Atlantic Continental
Gyre. Shelf.

[[Page 10989]]

Northern Gulf of NA.............. 152 (1.02)/75... NA............. Gulf of Mexico, NA.
Mexico \16\. Caribbean Sea.
Risso's dolphin.............. Grampus griseus. Western North NA.............. 18,250 (0.46)/ Gulf Stream, Southeast U.S. NA.
Atlantic. 12,619. North Atlantic Continental
Gyre. Shelf,
Northeast
United States
Continental
Shelf, Scotian
Shelf,
Newfoundland--
Labrador Shelf.
Northern Gulf of NA.............. 2,442 (0.57)/ NA............. Gulf of Mexico, NA.
Mexico. 1,563. Caribbean Sea.
Rough-toothed dolphin........ Steno Western North NA.............. 271 (1.00)/134.. Gulf Stream, Caribbean Sea NA.
bredanensis. Atlantic \16\. North Atlantic Southeast U.S.
Gyre. Continental
Shelf,
Northeast U.S.
Continental
Shelf.
Northern Gulf of NA.............. 624 (0.99)/311.. NA............. Gulf of Mexico, NA.
Mexico. Caribbean Sea.
Short-finned pilot whale..... Globicephala Western North Strategic....... 21,515 (0.37)/ NA............. Northeast NA.
macrorhynchus. Atlantic. 15,913. Continental
Shelf,
Southeast U.S.
Continental
Shelf.
Northern Gulf of NA.............. 2,415 (0.66)/ NA............. Gulf of Mexico, NA.
Mexico \22\. 1,456. Caribbean Sea.
Puerto Rico and Strategic....... Unknown......... NA............. Caribbean Sea.. NA.
U.S. Virgin
Islands.
Spinner dolphin.............. Stenella Western North NA.............. Unknown......... Gulf Stream, Southeast U.S. NA.
longirostris. Atlantic \16\. North Atlantic Continental
Gyre. Shelf,
Northeast U.S.
Continental
Shelf.
Northern Gulf of NA.............. 11,441 (0.83)/ NA............. Gulf of Mexico, NA.
Mexico \16\. 6,221. Caribbean Sea.
Puerto Rico and Strategic....... Unknown......... NA............. Caribbean Sea.. NA.
U.S. Virgin
Islands.
Striped dolphin.............. Stenella Western North NA.............. 54,807 (0.30)/ Gulf Stream.... Northeast U.S. NA.
coeruleoalba. Atlantic \16\. 42,804. Continental
Shelf, Scotian
Shelf.
Northern Gulf of NA.............. 1,849 (0.77)/ NA............. Gulf of Mexico, NA.
Mexico \16\. 1,041. Caribbean Sea.
Short-beaked common dolphin.. Delphinus Western North NA.............. 70,184 (0.28)/ Gulf Stream.... Southeast U.S. NA.
delphis. Atlantic. 55,690. Continental
Shelf,
Northeast U.S.
Continental
Shelf, Scotian
Shelf,
Newfoundland-
Labrador Shelf.
White-beaked dolphin......... Lagenorhynchus Western North NA.............. 2,003 (0.94)/ Labrador Northeast U.S. NA.
albirostris. Atlantic \23\. 1,023. Current. Continental
Shelf, Scotian
Shelf,
Newfoundland-
Labrador Shelf.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocoenidae (porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor porpoise.............. Phocoena........ Gulf of Maine/ NA.............. 79,883 (0.32)/ NA............. Northeast U.S. Narragansett
Bay of Fundy. 61,415. Continental Bay, Rhode
Shelf, Scotian Island Sound,
Shelf, Block Island
Newfoundland- Sound,
Labrador Shelf. Buzzards Bay,
Vineyard
Sound, Long
Island Sound,
Piscataqua
River, Thames
River,
Kennebec
River.

[[Page 10990]]

Gulf of St. NA.............. Unknown \24\.... Labrador Northeast U.S. NA.
Lawrence \24\. Current. Continental
Shelf, Scotian
Shelf,
Newfoundland-
Labrador Shelf.
Newfoundland NA.............. Unknown \25\.... Labrador Northeast U.S. NA.
\25\. Current. Continental
Shelf, Scotian
Shelf,
Newfoundland-
Labrador Shelf.
Greenland \26\.. NA.............. Unknown \26\.... Labrador Northeast U.S. NA.
Current. Continental
Shelf, Scotian
Shelf,
Newfoundland-
Labrador
Shelf, West
Greenland
Shelf.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora
--------------------------------------------------------------------------------------------------------------------------------------------------------
Suborder Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (true seals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray seal.................... Halichoerus Western North NA.............. Unknown......... NA............. Northeast U.S. Narragansett
grypus. Atlantic. Continental Bay, Rhode
Shelf, Scotian Island Sound,
Shelf, Block Island
Newfoundland- Sound,
Labrador Shelf. Buzzards Bay,
Vineyard
Sound, Long
Island Sound,
Piscataqua
River, Thames
River,
Kennebeck
River.
Harbor seal.................. Phoca vitulina.. Western North NA.............. 75,834 (0.15)/ NA............. Southeast U.S. Chesapeake Bay,
Atlantic. 66,884. Continental Narragansett
Shelf, Bay, Rhode
Northeast U.S. Island Sound,
Continental Block Island
Shelf, Scotian Sound,
Shelf, Buzzards Bay,
Newfoundland- Vineyard
Labrador Shelf. Sound, Long
Island Sound,
Piscataqua
River, Thames
River,
Kennebeck
River.
Harp seal.................... Pagophilus Western North NA.............. Unknown......... NA............. Northeast U.S. NA.
groenlandicus. Atlantic. Continental
Shelf, Scotian
Shelf,
Newfoundland-
Labrador Shelf.
Hooded seal.................. Cystophora Western North NA.............. Unknown......... NA............. Southeast U.S. Narragansett
cristata. Atlantic. Continental Bay, Rhode
Shelf, Island Sound,
Northeast U.S. Block Island
Continental Sound,
Shelf, Scotian Buzzards Bay,
Shelf, Vineyard
Newfoundland- Sound, Long
Labrador Island Sound,
Shelf, West Piscataqua
Greenland River, Thames
Shelf. River,
Kennebec
River.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes: CV: Coefficient of variation; ESA: Endangered Species Act; MMPA: Marine Mammal Protection Act; NA: Not applicable.
\1\ Taxonomy follows (Committee on Taxonomy, 2016).
\2\ Stock designations for the U.S. EEZ and abundance estimates are from Atlantic and Gulf of Mexico Stock Assessment Reports prepared by NMFS (Hayes et
al., 2017), unless specifically noted.

[[Page 10991]]

\3\ Populations or stocks defined by the MMPA as ``strategic'' for one of the following reasons: (1) The level of direct human-caused mortality exceeds
the potential biological removal level; (2) based on the best available scientific information, numbers are declining and species are likely to be
listed as threatened species under the ESA within the foreseeable future; (3) species are listed as threatened or endangered under the ESA; (4)
species are designated as depleted under the MMPA.
\4\ Stock abundance, CV, and minimum population are numbers provided by the Stock Assessment Reports (Hayes et al., 2017). The stock abundance is an
estimate of the number of animals within the stock. The CV is a statistical metric used as an indicator of the uncertainty in the abundance estimate.
The minimum population estimate is either a direct count (e.g., pinnipeds on land) or the lower 20th percentile of a statistical abundance estimate.
\5\ Occurrence in the AFTT Study Area includes open ocean areas--Labrador Current, North Atlantic Gyre, Gulf Stream, and coastal/shelf waters of seven
large marine ecosystems--West Greenland Shelf, Newfoundland-Labrador Shelf, Scotian Shelf, and Northeast U.S. Continental Shelf, Southeast U.S.
Continental Shelf, Caribbean Sea, Gulf of Mexico, and inland waters of Kennebec River, Piscataqua River, Thames River, Narragansett Bay, Rhode Island
Sound, Block Island Sound, Buzzards Bay, Vineyard Sound, Long Island Sound, Sandy Hook Bay, Lower Chesapeake Bay, James River, Elizabeth River,
Beaufort Inlet, Cape Fear River, Kings Bay, St. Johns River, Port Canaveral, St. Andrew Bay, Pascagoula River, Sabine Lake, Corpus Christi Bay, and
Galveston Bay.
\6\ The bowhead whale population off the west coast of Greenland is not managed by NMFS and, therefore, does not have an associated Stock Assessment
Report. Abundance and 95 percent highest density interval were presented in (Frasier et al., 2015).
\7\ The West Greenland stock of minke whales is not managed by NMFS and, therefore, does not have an associated Stock Assessment Report. Abundance and
95 percent confidence interval were presented in (Heide-J[oslash]rgensen et al., 2010).
\8\ The Labrador Sea stock of sei whales is not managed by NMFS and, therefore, does not have an associated Stock Assessment Report. Information was
obtained in (Prieto et al., 2014).
\9\ The West Greenland stock of fin whales is not managed by NMFS and, therefore, does not have an associated Stock Assessment Report. Abundance and 95
percent confidence interval were presented in (Heide-J[oslash]rgensen et al., 2010).
\10\ The Gulf of St. Lawrence stock of fin whales is not managed by NMFS and, therefore, does not have an associated Stock Assessment Report. Abundance
and 95 percent confidence interval were presented in (Ramp et al., 2014).
\11\ Photo identification catalogue count of 440 recognizable blue whale individuals from the Gulf of St. Lawrence is considered a minimum population
estimate for the western North Atlantic stock (Waring et al., 2010).
\12\ Estimates include both the pygmy and dwarf sperm whales in the western North Atlantic (Waring et al., 2014) and the northern Gulf of Mexico (Waring
et al., 2013).
\13\ Beluga whales in the Atlantic are not managed by NMFS and have no associated Stock Assessment Report. Abundance and 95 percent confidence interval
for the Eastern High Arctic/Baffin Bay stock were presented in (Innes et al., 2002).
\14\ Beluga whales in the Atlantic are not managed by NMFS and have no associated Stock Assessment Report. Abundance and 95 percent confidence interval
for the West Greenland stock were presented in (Heide-J[oslash]rgensen et al., 2009).
\15\ NA = Not applicable. Narwhals in the Atlantic are not managed by NMFS and have no associated Stock Assessment Report.
\16\ Estimates for these western North Atlantic stocks are from Waring et al. (2014) and the northern Gulf of Mexico stock are from (Waring et al.,
2013) as applicable.
\17\ Estimate includes undifferentiated Mesoplodon species.
\18\ Estimate includes Gervais' and Blainville's beaked whales.
\19\ Estimate may include sightings of the coastal form.
\20\ Estimates for these Gulf of Mexico stocks are from Waring et al. (2016).
\21\ NMFS is in the process of writing individual stock assessment reports for each of the 32 bay, sound, and estuary stocks.
\22\ Estimates for these stocks are from Waring et al., (2015).
\23\ Estimates for these western North Atlantic stocks are from (Waring et al., 2007).
\24\ Harbor porpoise in the Gulf of St. Lawrence are not managed by NMFS and have no associated Stock Assessment Report.
\25\ Harbor porpoise in Newfoundland are not managed by NMFS and have no associated Stock Assessment Report.
\26\ Harbor porpoise in Greenland are not managed by NMFS and have no associated Stock Assessment Report.

Important Marine Mammal Habitat

ESA Critical Habitat for North Atlantic Right Whale
The only ESA-listed marine mammal with designated critical habitat
within the AFTT Study Area is the North Atlantic right whale (NARW). On
February 26, 2016, NMFS issued a final rule (81 FR 4837) to replace the
critical habitat for NARW with two new areas. The areas now designated
as critical habitat contain approximately 29,763 nmi\2\ of marine
habitat in the Gulf of Maine and Georges Bank region (Unit 1),
essential for NARW foraging and off the Southeast U.S. coast (Unit 2),
including the coast of North Carolina, South Carolina, Georgia, and
Florida, which are key areas essential for calving. These two ESA-
designated critical habitats were established to replace three smaller
previously ESA-designated critical habitats (Cape Cod Bay/Massachusetts
Bay/Stellwagen Bank, Great South Channel, and the coastal waters of
Georgia and Florida in the southeastern United States) that had been
designated by NMFS in 1994 (59 FR 28805; June 3, 1994). Two additional
areas in Canadian waters, Grand Manan Basin and Roseway Basin, were
identified and designated as critical habitat under Canada's endangered
species law (Section 58 (5) of the Species at Risk Act (SARA), S. C.
2002, c. 29) and identified in Final Recovery Strategy for the North
Atlantic right whale, posted June 2009 on the SARA Public Registry.
Unit 1 encompasses the Gulf of Maine and Georges Bank region
including the large embayments of Cape Cod Bay and Massachusetts Bay
and deep underwater basins, as well as state waters, except for inshore
areas, bays, harbors, and inlets, from Maine through Massachusetts in
addition to Federal waters, all of which are key areas. Unit 1 includes
the large embayments of Cape Cod Bay and Massachusetts Bay but does not
include inshore areas, bays, harbors and inlets. It also does not
include waters landward of the 72 COLREGS lines (33 CFR part 80). A
large portion of the critical habitat of Unit 1 lies within the coastal
waters of the Boston OPAREA (see Figure 4.1-1 of the Navy's rulemaking
and LOA application).
Unit 2 consists of all marine waters from Cape Fear, North
Carolina, southward to approximately 27 nmi below Cape Canaveral,
Florida, within the area bounded on the west by the shoreline and the
72 COLREGS lines, and on the east by rhumb lines connecting the
specific points described below. The physical features correlated with
the distribution of NARW in the southern critical habitat area provide
an optimum environment for calving in the waters of Brunswick County,
North Carolina; Horry, Georgetown, Charleston, Colleton, Beaufort, and
Jasper Counties, South Carolina; Chatham, Bryan, Liberty, McIntosh,
Glynn, and Camden Counties, Georgia; and Nassau, Duval, St. John's,
Flagler, Volusia, and Brevard Counties, Florida. For example, the
bathymetry of the inner and nearshore middle shelf area minimizes the
effect of strong winds and offshore waves, limiting the formation of
large waves and rough water. The average temperature of critical
habitat waters is cooler during the time right whales are present due
to a lack of influence by the Gulf Stream and cool freshwater runoff
from coastal areas. The water temperatures may provide an optimal
balance between offshore waters that are too warm for nursing mothers
to tolerate, yet not too cool for calves that may only have minimal
fatty insulation. Reproductive females and calves are expected to be
concentrated in the critical habitat from December through April. A
majority of the critical habitat of Unit 2 lies within the coastal
waters of the Jacksonville OPAREA and the Charleston OPAREA (see Figure
4.1-1 of the Navy's rulemaking and LOA application).

Important Habitat for Sperm Whales

Sperm whales aggregate at the mouth of the Mississippi River and
along the continental slope in or near cyclonic cold-core eddies
(counterclockwise water movements in the northern hemisphere with a
cold center) or

[[Page 10992]]

anticyclone eddies (clockwise water movements in the northern
hemisphere) (Davis et al., 2007). Habitat models for sperm whale
occurrence indicate a high probability of suitable habitat along the
shelf break off the Mississippi delta, Desoto Canyon, and western
Florida (Best et al., 2012; Weller et al., 2000). Due to the nutrient-
rich freshwater plume from the Mississippi Delta the continental slope
waters south of the Mississippi River Delta and the Mississippi Canyon
play an important ecological role for sperm whales (Davis et al., 2002;
Weller et al., 2000). Sightings during extensive surveys in this area
consisted of mixed-sex groups of females, immature males, and mother-
calf pairs as well as groups of bachelor males (Jochens et al., 2008;
Weller et al., 2000). Female sperm whales have displayed a high level
of site fidelity and year round utilization off the Mississippi River
Delta compared to males (Jochens et al., 2008) suggesting this area may
also support year-round feeding, breeding, and nursery areas
(Baumgartner et al., 2001; NMFS, 2010), although the seasonality of
breeding in Gulf of Mexico sperm whales is not known (Jochens et al.,
2008).
Biologically Important Areas
Biologically Important Areas (BIAs) include areas of known
importance for reproduction, feeding, or migration, or areas where
small and resident populations are known to occur (LeBrecque et al.,
2015a and 2015b). Unlike Critical Habitat, these areas are not formally
designated pursuant to any statute or law, but are a compilation of the
best available science intended to inform impact and mitigation
analyses.
On the East Coast, 19 of the 24 identified BIAs fall within or
overlap with the AFTT Study area--10 feeding (2 for minke whale, 1 for
sei whale, 3 for fin whale, 3 for NARW, and 1 for humpback), 1
migration (NARW), 2 reproduction (NARW), 6 small and resident
population (1 for harbor porpoise and 5 for bottlenose dolphin).
Figures 11.2-1 through11.2-2 of the Navy's rulemaking and LOA
application illustrate how these BIAs overlap with Navy OPAREAs on the
East Coast. In the Gulf of Mexico, 4 of the 12 identified BIAs for
small and resident populations overlap the AFTT study area (1 for
Bryde's whale and 3 for Bottlenose dolphin). Figures 11.2-3 of the
Navy's rulemaking and LOA application illustrate how these BIAs overlap
with Navy OPAREAs in the Gulf of Mexico.

Large Whales Feeding BIAs--East Coast Within the AFTT Study Area

Two minke whale feeding BIAs are located in the northeast Atlantic
from March through November in waters less than 200 m in the southern
and southwestern section of the Gulf of Maine including Georges Bank,
the Great South Channel, Cape Cod Bay and Massachusetts Bay, Stellwagen
Bank, Cape Anne, and Jeffreys Ledge (LaBrecque et al. (2015a, 2015b))
LaBrecque et al. (2015b) delineated a feeding area for sei whales in
the northeast Atlantic between the 25-meter contour off coastal Maine
and Massachusetts to the 200-meter contour in central Gulf of Maine,
including the northern shelf break area of Georges Bank. The feeding
area also includes the southern shelf break area of Georges Bank from
100 to 2,000 m and the Great South Channel. Feeding activity is
concentrated from May through November with a peak in July and August.
LaBrecque et al. (2015b) identified three feeding areas for fin whales
in the North Atlantic within the AFTT Study Area: (1) June to October
in the northern Gulf of Maine; (2) year-round in the southern Gulf of
Maine, and (3) March to October east of Montauk Point. LaBrecque et al.
(2015b) delineated a humpback whale feeding area in the Gulf of Maine,
Stellwagen Bank, and Great South Channel.

NARW BIAs--East Coast Within the AFTT Study Area

LaBrecque et al. (2015b) identified three seasonal NARW feeding
areas BIAs located in or near the AFTT Study Area (1) February to April
on Cape Cod Bay and Massachusetts Bay (2) April to June in the Great
South Channel and on the northern edge of Georges Bank, and (3) June to
July and October to December on Jeffreys Ledge in the western Gulf of
Maine. A mating BIA was identified in the central Gulf of Maine (from
November through January), a calving BIA in the southeast Atlantic
(from mid-November to late April) and the migratory corridor area BIA
along the U.S. East Coast between the NARW southern calving grounds and
northern feeding areas (see Figure 11.2-1 and 11.2-2 of the Navy's
rulemaking and LOA application for how these BIAs overlap with Navy
OPAREAs).

Harbor Porpoise BIA--East Coast Within the AFTT Study Area

LaBrecque et al. (2015b) identified a small and resident population
BIA for harbor porpoise in the Gulf of Maine (see Figure 11.2-1 of the
Navy's rulemaking and LOA application). From July to September, harbor
porpoises are concentrated in waters less than 150 m deep in the
northern Gulf of Maine and southern Bay of Fundy. During fall (October
to December) and spring (April to June), harbor porpoises are widely
dispersed from New Jersey to Maine, with lower densities farther north
and south (LaBrecque et al., 2015b).

Bottlenose Dolphin BIAs--East Coast Within the AFTT Study Area

LaBrecque et al. (2015b) identified nine small and resident
bottlenose dolphin population areas within estuarine areas along the
east coast of the U.S. (see Figure 11.2-2 of the Navy's rulemaking and
LOA application). These areas include estuarine and nearshore areas
extending from Pamlico Sound, North Carolina down to Florida Bay,
Florida (LaBrecque et al., 2015b). The Northern North Carolina
Estuarine System, Southern North Carolina Estuarine System, and
Charleston Estuarine System populations partially overlap with
nearshore portions of the Navy Cherry Point Range Complex and
Jacksonville Estuarine System Populations partially overlaps with
nearshore portions of the Jacksonville Range Complex. The Southern
Georgia Estuarine System Population area also overlaps with the
Jacksonville Range Complex, specifically within Naval Submarine Base
Kings Bay, Kings Bay, Georgia and includes estuarine and intercoastal
waterways from Altamaha Sound, to the Cumberland River (LaBrecque et
al., 2015b). The remaining four BIAs are outside but adjacent to the
AFTT Study Area boundaries.

Bottlenose Dolphin BIAs--Gulf of Mexico Within the AFTT Study Area

LaBrecque et al. (2015) also described 11 year-round BIAs for small
and resident estuarine stocks of bottlenose dolphin that primarily
inhabit inshore waters of bays, sounds, and estuaries (BSE) in the Gulf
of Mexico (see Figure 11.2-3 in the Navy's rulemaking and LOA
application). Of the 11 BIAs identified for the BSE bottlenose dolphins
in the Gulf of Mexico, three overlap with the Gulf of Mexico Range
Complex (Aranas Pass Area, Texas; Mississippi Sound Area, Mississippi;
and St. Joseph Bay Area, Florida), while eight are located adjacent to
the AFTT Study Area boundaries.

Bryde's Whale BIA--Gulf of Mexico Within the AFTT Study Area

The Gulf of Mexico Bryde's whale is a very small population that is
genetically distinct from other Bryde's whales and not genetically
diverse

[[Page 10993]]

within the Gulf of Mexico (Rosel and Wilcox, 2014). Further, the
species is typically observed only within a narrowly circumscribed area
within the eastern Gulf of Mexico. Therefore, this area is described as
a year-round BIA by LaBrecque et al. (2015). Although survey effort has
covered all oceanic waters of the U.S. Gulf of Mexico, whales were
observed only between approximately the 100- and 300-m isobaths in the
eastern Gulf of Mexico from the head of the De Soto Canyon (south of
Pensacola, Florida) to northwest of Tampa Bay, Florida (Maze-Foley and
Mullin, 2006; Waring et al., 2016; Rosel and Wilcox, 2014; Rosel et
al., 2016). Rosel et al. (2016) expanded this description by stating
that, due to the depth of some sightings, the area is more
appropriately defined to the 400-m isobath and westward to Mobile Bay,
Alabama, in order to provide some buffer around the deeper sightings
and to include all sightings in the northeastern Gulf of Mexico.
National Marine Sanctuaries
Under Title III of the Marine Protection, Research, and Sanctuaries
Act of 1972 (also known as the National Marine Sanctuaries Act (NMSA)),
NOAA can establish as national marine sanctuaries (NMS) areas of the
marine environment with special conservation, recreational, ecological,
historical, cultural, archaeological, scientific, educational, or
aesthetic qualities. Sanctuary regulations prohibit destroying, causing
the loss of, or injuring any sanctuary resource managed under the law
or regulations for that sanctuary (15 CFR part 922). NMS are managed on
a site-specific basis, and each sanctuary has site-specific
regulations. Most, but not all sanctuaries have site-specific
regulatory exemptions from the prohibitions for certain military
activities. Additionally, section 304(d) of the NMSA requires Federal
agencies to consult with the NOAA Office of National Marine Sanctuaries
whenever their Proposed Activity are likely to destroy, cause the loss
of, or injure a sanctuary resource.
Three NMS are in the vicinity of or overlap with the AFTT Study
Area including the Gerry E. Studds Stellwagen Bank National Marine
Sanctuary (Stellwagen Bank NMS), Gray's Reef National Marine Sanctuary
(Gray's Reef NMS), and Florida Keys National Marine Sanctuary (Florida
Keys NMS). Stellwagen Bank NMS sits at the mouth of Massachusetts Bay,
just three miles south of Cape Ann, three miles north of Cape Cod and
25 mi due east of Boston and provides feeding and nursery grounds for
marine mammals including NARW, humpback, sei, and fin whales. The
Stellwagen Bank NMS is within critical habitat for the NARW for
foraging (Unit 1). Gray's Reef NMS is 19 mi east of Sapelo Island
Georgia, in the South Atlantic Bight (the offshore area between Cape
Hatteras, North Carolina and Cape Canaveral, Florida) and is within the
designated critical habitat for NARW calving in the southeast (Unit 2).
Florida Keys NMS protects 2,900 nmi \2\ of waters surrounding the
Florida Keys, from south of Miami westward to encompass the Dry
Tortugas, excluding Dry Tortugas National Park and supports a resident
group of bottlenose dolphin (Florida Bay Population BIA). Two
additional sanctuaries, Flower Gardens NMS in the Gulf of Mexico and
Monitor NMS off of North Carolina, were determined by the Navy as
unnecessary to consult on based on the lack of impacts to sanctuary
resources for section 304(d) under NMSA and therefore not discussed
further.
Unusual Mortality Events (UME)
A UME is defined under Section 410(6) of the MMPA as a stranding
that is unexpected; involves a significant die-off of any marine mammal
population; and demands immediate response. From 1991 to the present,
there have been 34 formally recognized UMEs affecting marine mammals
along the Atlantic Coast and the Gulf of Mexico involving species under
NMFS's jurisdiction. The NARW, humpback whale, and minke whale UMEs on
the Atlantic Coast are still active and involve ongoing investigations
and the impacts to Barataria Bay bottlenose dolphins from the expired
UME associated with the Deepwater Horizon (DWH) oil spill in the Gulf
of Mexico are thought to be persistent and continue to inform
population analyses. The other UMEs expired several years ago and
little is known about how the effects of those events might be
appropriately applied to an impact assessment several years later. The
three UMEs that could inform the current analysis are discussed below.

NARW UME

Since June 7, 2017, elevated mortalities of NARW have occurred. A
total of 16 confirmed dead stranded NARW (12 in Canada; 4 in the United
States), and five live whale entanglements in Canada have been
documented to date predominantly in the Gulf of St. Lawrence region of
Canada and around the Cape Cod area of Massachusetts. An additional
whale stranded in the United States in April 2017 prior to the start of
the UME bringing the annual 2017 total to 17 confirmed dead stranded
whales (12 in Canada; 5 in the United States) as of December 5, 2017.
Historically (2006-2016), the annual average for dead strandings in
Canada and the United States combined is 3.8 whales per year. This
event was declared a UME and is under investigation. Full necropsy
examinations have been conducted on 11 of the 17 whales and final
results from the examinations are pending. Necropsy results from six of
the Canadian whales suggest mortalities of four whales were compatible
with blunt trauma likely caused by vessel collision and one mortality
confirmed from chronic entanglement in fishing gear. The sixth whale
was too decomposed to determine the cause of mortality, but some
observations in this animal suggested blunt trauma. A seventh necropsy
has been performed, but the results are not currently available (Daoust
et al., 2017). Daoust et al. (2017) also concluded there were no oil
and gas seismic surveys authorized in the months prior to or during the
period over which these mortalities occurred, as well as no blasting or
major marine development projects. All of the NARW that stranded in the
United States that are part of the UME have been significantly
decomposed at the time of stranding, and investigations have been
limited. Sonar has not been investigated for the mortalities in the
United States.
As part of the UME investigation process, an independent team of
scientists (Investigative Team) was assembled to coordinate with the
Working Group on Marine Mammal Unusual Mortality Events to review the
data collected, sample future whales that strand and to determine the
next steps for the investigation. For more information on this UME,
please refer to https://www.fisheries.noaa.gov/national/marine-life-distress/2017-2018-north-atlantic-right-whale-unusual-mortality-event.

Humpback Whale UME Along the Atlantic Coast

Since January 2016, elevated mortalities of humpback whales along
the Atlantic coast from Maine through North Carolina have occurred. As
of December 1, 2017 a total of 58 humpback strandings have occurred (26
and 32 whales in 2016 and 2017, respectively). As of April 2017,
partial or full necropsy examinations were conducted on 20 cases, or
approximately half of the 42 strandings (at that time). Of the 20
whales examined, 10 had evidence of blunt force trauma or pre-mortem
propeller wounds indicative of vessel strike,

[[Page 10994]]

which is over six times above the 16-year average of 1.5 whales showing
signs of vessel strike in this region. Vessel strikes were documented
for stranded humpback whales in Virginia (3), New York (3), Delaware
(2), Massachusetts (1) and New Hampshire (1). NOAA, in coordination
with our stranding network partners, continues to investigate the
recent mortalities, environmental conditions, and population monitoring
to better understand the recent humpback whale mortalities. At this
time, vessel parameters (including size) are not known for each vessel-
whale collision that lead to the death of the whales. Therefore, NOAA
considers all sizes of vessels to be risks for whale species in highly
trafficked areas. This investigation is ongoing. Please refer to http://www.nmfs.noaa.gov/pr/health/mmume/2017humpbackatlanticume.html for
more information on this UME.

Minke Whale UME Along the Atlantic Coast

Since January 2017, elevated mortalities of minke whale along the
Atlantic coast from Maine through South Carolina have occurred. As of
February 16, 2018, a total of 30 strandings have occurred (28 and 2
whales in 2017 and 2018, respectively). As of February 16, 2018 full or
partial necropsy examinations were conducted on over 60 percent of the
whales. Preliminary findings in several of the whales have shown
evidence of human interactions, primarily fisheries interactions, or
infectious disease. These findings are not consistent across all of the
whales examined, so more research is needed. This investigation is
ongoing. Please refer to https://www.fisheries.noaa.gov/national/marine-life-distress/2017-2018-minke-whale-unusual-mortality-event-along-atlantic-coast for more information on this UME.

Cetacean UME in the Northern Gulf of Mexico and Persistent Impacts on
Barataria Bay Bottlenose Dolphins

The cetacean UME in the northern Gulf of Mexico UME occurred from
March 2010 through July 2014. The event included all cetaceans stranded
during this time in Alabama, Mississippi, and Louisiana and all
cetaceans other than bottlenose dolphins stranded in the Florida
Panhandle (Franklin County through Escambia County), with a total of
1,141 cetaceans stranded or reported dead offshore. For reference, the
same area experienced a normal average of 75 strandings per year from
2002-09 (Litz et al., 2014). The majority of stranded animals were
bottlenose dolphins, though at least ten additional species were
reported as well. Since not all cetaceans that die wash ashore where
they may be found, the number reported stranded is likely a fraction of
the total number of cetaceans that died during the UME. There was also
an increase in strandings of stillborn and newborn dolphins (Colegrove
et al., 2016).
Increased dolphin strandings occurred in northern Louisiana and
Mississippi before the DWH oil spill (March-mid-April 2010). Some
previous Gulf of Mexico cetacean UMEs had included environmental
influences (e.g., low salinity due to heavy rainfall and associated
runoff of land-based pesticides, low temperatures) as possible
contributing factors (Litz et al., 2014). Low air and water
temperatures occurred in the spring of 2010 throughout the Gulf of
Mexico prior to and during the start of the UME, and a portion of the
pre-spill atypical strandings occurred in Lake Pontchartrain,
Louisiana, concurrent with lower than average salinity (Mullin et al.,
2015). Therefore, a large part of the increased dolphin strandings
during this time may have been due to a combination of cold
temperatures and low salinity (Litz et al., 2014).
The UME investigation and the DWH Natural Resource Damage
Assessment (described below) determined that the DWH oil spill is the
most likely explanation of the persistent, elevated stranding numbers
in the northern Gulf of Mexico after the spill that began on April 20,
2010. The evidence to date supports that exposure to hydrocarbons
released during the DWH oil spill was the most likely explanation of
adrenal and lung disease in dolphins, which contributed to increased
deaths of dolphins living within the oil spill footprint and increased
fetal loss. The longest and most prolonged stranding cluster of the UME
was in Barataria Bay, Louisiana in 2010-11, followed by Mississippi and
Alabama in 2011, consistent with timing and spatial distribution of
oil, while the number of deaths was not elevated for areas which were
not as heavily oiled.
In order to assess the health of free-ranging (not stranded)
dolphin capture-release health assessments were conducted in Barataria
Bay, during which physical examinations, including weighing and
morphometric measurements, were conducted, routine biological samples
(e.g., blood, tissue) were obtained, and animals were examined with
ultrasound. Veterinarians then reviewed the findings and determined an
overall prognosis for each animal (e.g., favorable outcome expected,
outcome uncertain, unfavorable outcome expected). Almost half of the
examined animals were given a guarded or worse prognosis, and 17
percent were not expected to survive (Schwacke et al., 2014a).
Comparison of Barataria Bay dolphins to a reference population found
significantly increased adrenal disease, lung disease, and poor health.
In addition to the health assessments, histological evaluations of
samples from dead stranded animals from within and outside the UME area
found that UME animals were more likely to have lung and adrenal
lesions and to have primary bacterial pneumonia, which caused or
contributed significantly to death (Schwacke et al., 2014a, 2014b;
Venn-Watson et al., 2015b).
The prevalence of brucellosis and morbillivirus infections was low
and biotoxin levels were low or below the detection limit, meaning that
these were not likely primary causes of the UME (Venn-Watson et al.,
2015b; Fauquier et al., 2017). Subsequent study found that persistent
organic pollutants (e.g., polychlorinated biphenyls), which are
associated with endocrine disruption and immune suppression when
present in high levels, are likely not a primary contributor to the
poor health conditions and increased mortality observed in these Gulf
of Mexico populations (Balmer et al., 2015). The chronic adrenal gland
and lung diseases identified in stranded UME dolphins are consistent
with exposure to petroleum compounds (Venn-Watson et al., 2015b).
Colegrove et al. (2016) found that the increase in perinatal strandings
resulted from late-term pregnancy failures and development of in utero
infections likely caused by chronic illnesses in mothers who were
exposed to oil.
While the number of dolphin mortalities in the area decreased after
the peak from March 2010-July 2014, it does not follow that the effects
of the oil spill on these populations have ended. Researchers still saw
evidence of chronic lung disease and adrenal impairment four years
after the spill (in July 2014) and saw evidence of failed pregnancies
in 2015 (Smith et al., 2017). These follow-up studies found a yearly
mortality rate for Barataria Bay dolphins of roughly 13 percent (as
compared to annual mortality rates of 5 percent or less that have been
previously reported for other dolphin populations), and found that only
20 percent of pregnant dolphins produced viable calves (compared with
83 percent in a reference population) (Lane et al., 2015; McDonald et
al., 2017). Research into the long-term health effects of the spill

[[Page 10995]]

on marine mammal populations is ongoing. For more information on the
UME, please visit www.nmfs.noaa.gov/pr/health/mmume/cetacean_gulfofmexico.htm.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Current data indicate that not all marine
mammal species have equal hearing capabilities (e.g., Richardson et
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect
this, Southall et al. (2007) recommended that marine mammals be divided
into functional hearing groups based on directly measured or estimated
hearing ranges on the basis of available behavioral response data,
audiograms derived using auditory evoked potential techniques,
anatomical modeling, and other data. Note that no direct measurements
of hearing ability have been successfully completed for mysticetes
(i.e., low-frequency cetaceans). Subsequently, NMFS (2016) described
generalized hearing ranges for these marine mammal hearing groups.
Generalized hearing ranges were chosen based on the approximately 65 dB
threshold from the normalized composite audiograms, with the exception
for lower limits for low-frequency cetaceans where the lower bound was
deemed to be biologically implausible and the lower bound from Southall
et al. (2007) retained. 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):
[ssquf] Low-frequency cetaceans (mysticetes): Generalized hearing
is estimated to occur between approximately 7 Hz and 35 kHz, with best
hearing estimated to be from 100 Hz to 8 kHz;
[ssquf] Mid-frequency cetaceans (larger toothed whales, beaked
whales, and most delphinids): Generalized hearing is estimated to occur
between approximately 150 Hz and 160 kHz, with best hearing from 10 kHz
to less than 100 kHz;
[ssquf] High-frequency cetaceans (porpoises, river dolphins, and
members of the genera Kogia and Cephalorhynchus; including two members
of the genus Lagenorhynchus, on the basis of recent echolocation data
and genetic data): Generalized hearing is estimated to occur between
approximately 275 Hz and 160 kHz.
[ssquf] Pinnipeds in water; Phocidae (true seals): Generalized
hearing is estimated to occur between approximately 50 Hz to 86 kHz,
with best hearing between 1-50 kHz;
[ssquf] Pinnipeds in water; Otariidae (eared seals): Generalized
hearing is estimated to occur between 60 Hz and 39 kHz, with best
hearing between 2-48 kHz.
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 and Holt,
2013).
For more detail concerning these groups above and associated
frequency ranges, please see NMFS (2016) for a review of available
information.

Potential Effects of Specified Activities on Marine Mammals and Their
Habitat

This section includes a summary and discussion of the ways that
components of the specified activity may impact marine mammals and
their habitat. The ``Estimated Take of Marine Mammals'' section later
in this document includes a quantitative analysis of the number of
individuals that are expected to be taken by this activity. The
``Negligible Impact Analysis and Determination'' section considers the
content of this section, the ``Estimated Take of Marine Mammals''
section, and the ``Proposed Mitigation'' section, to draw conclusions
regarding the likely impacts of these activities on the reproductive
success or survivorship of individuals and how those impacts on
individuals are likely to impact marine mammal species or stocks.
The Navy has requested authorization for the take of marine mammals
that may occur incidental to training and testing activities in the
AFTT Study Area. The Navy analyzed potential impacts to marine mammals
from acoustics and explosives sources as well as vessel strikes.
Other potential impacts to marine mammals from training and testing
activities in the AFTT Study Area were analyzed in the AFTT DEIS/OEIS,
in consultation with NMFS as a cooperating agency, and determined to be
unlikely to result in marine mammal take in the form of harassment,
serious injury, or mortality. Therefore, the Navy has not requested
authorization for take of marine mammals that might occur incidental to
other components of their proposed activities and we agree that take is
unlikely to occur from those components. In this proposed rule, NMFS
analyzes the potential effects on marine mammals from the activity
components that may cause the take of marine mammals: Exposure to non-
impulsive (sonar and other active acoustic sources) and impulsive
(explosives, ship shock trials, impact pile driving, and airguns)
stressors, and vessel strikes.
For the purpose of MMPA incidental take authorizations, NMFS'
effects assessments serve four primary purposes: (1) To prescribe the
permissible methods of taking (i.e., Level B harassment (behavioral
harassment and temporary threshold shift (TTS)), Level A harassment
(permanent threshold shift (PTS) or non-auditory injury), serious
injury or mortality, including an identification of the number and
types of take that could occur by harassment, serious injury, 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 (however, there are no
subsistence communities that would be affected in the AFTT Study Area,
so this determination is inapplicable to the AFTT rulemaking); and (4)
to prescribe requirements pertaining to monitoring and reporting.
In the Potential Effects Section, NMFS' provides a general
description of the ways marine mammals may be affected by these
activities in the form of mortality, physical trauma, sensory
impairment (permanent and temporary threshold shifts and acoustic
masking), physiological responses (particular stress responses),
behavioral disturbance, or habitat effects. Ship shock and vessel
strikes, which have the potential to result in incidental take from
serious injury and/or mortality, will be discussed in more detail in
the ``Estimated Take of Marine Mammals'' section. The Estimated Take of
Marine Mammals section also discusses how the potential effects on
marine mammals from non-impulsive and impulsive sources relate to the
MMPA definitions of Level A and Level B Harassment, and quantifies
those effects that rise to the level of a take along with

[[Page 10996]]

the potential effects from vessel strikes. The Negligible Impact
Analysis Section assesses whether the proposed authorized take will
have a negligible impact on the affected species and stocks.

Potential Effects of Underwater Sound

Note that, in the following discussion, we refer in many cases to a
review article concerning studies of noise-induced hearing loss
conducted from 1996-2015 (i.e., Finneran, 2015). For study-specific
citations, please see that work. Anthropogenic sounds cover a broad
range of frequencies and sound levels and can have a range of highly
variable impacts on marine life, from none or minor to potentially
severe responses, depending on received levels, duration of exposure,
behavioral context, and various other factors. The potential effects of
underwater sound from active acoustic sources can potentially result in
one or more of the following: Temporary or permanent hearing
impairment, non-auditory physical or physiological effects, behavioral
disturbance, stress, and masking (Richardson et al., 1995; Gordon et
al., 2004; Nowacek et al., 2007; Southall et al., 2007; G[ouml]tz et
al., 2009). The degree of effect is intrinsically related to the signal
characteristics, received level, distance from the source, and duration
of the sound exposure. In general, sudden, high level sounds can cause
hearing loss, as can longer exposures to lower level sounds. Temporary
or permanent loss of hearing will occur almost exclusively for noise
within an animal's hearing range. We first describe specific
manifestations of acoustic effects before providing discussion specific
to the Navy's activities.
Richardson et al. (1995) described zones of increasing intensity of
effect that might be expected to occur, in relation to distance from a
source and assuming that the signal is within an animal's hearing
range. First is the area within which the acoustic signal would be
audible (potentially perceived) to the animal, but not strong enough to
elicit any overt behavioral or physiological response. The next zone
corresponds with the area where the signal is audible to the animal and
of sufficient intensity to elicit behavioral or physiological
responsiveness. Third is a zone within which, for signals of high
intensity, the received level is sufficient to potentially cause
discomfort or tissue damage to auditory or other systems. Overlaying
these zones to a certain extent is the area within which masking (i.e.,
when a sound interferes with or masks the ability of an animal to
detect a signal of interest that is above the absolute hearing
threshold) may occur; the masking zone may be highly variable in size.
We also describe more severe effects (i.e., certain non-auditory
physical or physiological effects). Potential effects from impulsive
sound sources can range in severity from effects such as behavioral
disturbance or tactile perception to physical discomfort, slight injury
of the internal organs and the auditory system, or mortality (Yelverton
et al., 1973). Non-auditory physiological effects or injuries that
theoretically might occur in marine mammals exposed to high level
underwater sound or as a secondary effect of extreme behavioral
reactions (e.g., change in dive profile as a result of an avoidance
reaction) caused by exposure to sound include neurological effects,
bubble formation, resonance effects, and other types of organ or tissue
damage (Cox et al., 2006; Southall et al., 2007; Zimmer and Tyack,
2007; Tal et al., 2015).

Acoustic Sources

Direct Physiological Effects
Based on the literature, there are two basic ways that non-
impulsive sources might directly result in direct physiological
effects. Noise-induced loss of hearing sensitivity (more commonly-
called ``threshold shift'') is the both the better-understood of these
two effects, and the only one that is actually expected to occur.
Acoustically mediated bubble growth and other pressure-related
physiological impacts are addressed briefly below, but are not expected
to result from the Navy's activities. Separately, an animal's
behavioral reaction to an acoustic exposure might lead to physiological
effects that might ultimately lead to injury or death, which is
discussed later in the Stranding Section.

Threshold Shift (Noise-Induced Loss of Hearing)

When animals exhibit reduced hearing sensitivity within their
auditory range (i.e., sounds must be louder for an animal to detect
them) following exposure to a sufficiently intense sound or a less
intense sound for a sufficient duration, it is referred to as a noise-
induced threshold shift (TS). An animal can experience a temporary
threshold shift (TTS) and/or permanent threshold shift (PTS). TTS can
last from minutes or hours to days (i.e., there is recovery back to
baseline/pre-exposure levels), can occur within a specific frequency
range (i.e., an animal might only have a temporary loss of hearing
sensitivity within a limited frequency band of its auditory range), and
can be of varying amounts (for example, an animal's hearing sensitivity
might be reduced by only 6 dB or reduced by 30 dB). Repeated sound
exposure that leads to TTS could cause PTS. In severe cases of PTS,
there can be total or partial deafness, while in most cases the animal
has an impaired ability to hear sounds in specific frequency ranges
(Kryter, 1985). When PTS occurs, there is physical damage to the sound
receptors in the ear (i.e., tissue damage), whereas TTS represents
primarily tissue fatigue and is reversible (Southall et al., 2007). PTS
is permanent (i.e., there is incomplete recovery back to baseline/pre-
exposure levels), but also can occur in a specific frequency range and
amount as mentioned above for TTS. In addition, other investigators
have suggested that TTS is within the normal bounds of physiological
variability and tolerance and does not represent physical injury (e.g.,
Ward, 1997). Therefore, NMFS does not consider TTS to constitute
auditory injury.
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.
Generally, the amount of TS, and the time needed to recover from the
effect, increase as amplitude and duration of sound exposure increases.
Human non-impulsive noise exposure guidelines are based on the
assumption that exposures of equal energy (the same SEL) produce equal
amounts of hearing impairment regardless of how the sound energy is
distributed in time (NIOSH, 1998). Previous marine mammal TTS studies
have also generally supported this equal energy relationship (Southall
et al., 2007). However, some more recent studies concluded that for all
noise exposure situations the equal energy relationship may not be the
best indicator to predict TTS onset levels (Mooney et al., 2009a and
2009b; Kastak et al., 2007). These studies highlight the inherent
complexity of predicting TTS onset in marine mammals, as well as the
importance of considering exposure duration when assessing potential

[[Page 10997]]

impacts. Generally, with sound exposures of equal energy, those that
were quieter (lower SPL) with longer duration were found to induce TTS
onset at lower levels than those of louder (higher SPL) and shorter
duration. Less TS will occur from intermittent sounds than from a
continuous exposure with the same energy (some recovery can occur
between intermittent exposures) (Kryter et al., 1966; Ward, 1997;
Mooney et al., 2009a, 2009b; Finneran et al., 2010). For example, one
short but loud (higher SPL) sound exposure may induce the same
impairment as one longer but softer (lower SPL) sound, which in turn
may cause more impairment than a series of several intermittent softer
sounds with the same total energy (Ward, 1997). Additionally, though
TTS is temporary, very prolonged or repeated exposure to sound strong
enough to elicit TTS, or shorter-term exposure to sound levels well
above the TTS threshold can cause PTS, at least in terrestrial mammals
(Kryter, 1985; Lonsbury-Martin et al., 1987).
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. The
NMFS 2016 Acoustic Technical Guidance, which was used in the assessment
of effects for this action, compiled, interpreted, and synthesized the
best available scientific information for noise-induced hearing effects
for marine mammals to derive updated thresholds for assessing the
impacts of noise on marine mammal hearing, as noted above. For
cetaceans, published data on the onset of TTS are limited to the
captive bottlenose dolphin, beluga, harbor porpoise, and Yangtze
finless porpoise (summarized in Finneran, 2015). TTS studies involving
exposure to other Navy activities (e.g., SURTASS LFA) or other low-
frequency sonar (below 1 kHz) have never been conducted due to
logistical difficulties of conducting experiments with low frequency
sound sources. However, there are TTS measurements for exposures to
other LF sources, such as seismic airguns. Finneran et al. (2015)
suggest that the potential for airguns to cause hearing loss in
dolphins is lower than previously predicted, perhaps as a result of the
low-frequency content of airgun impulses compared to the high-frequency
hearing ability of dolphins. Finneran et al. (2015) measured hearing
thresholds in three captive bottlenose dolphins before and after
exposure to ten pulses produced by a seismic airgun in order to study
TTS induced after exposure to multiple pulses. Exposures began at
relatively low levels and gradually increased over a period of several
months, with the highest exposures at peak SPLs from 196 to 210 dB and
cumulative (unweighted) SELs from 193-195 dB. No substantial TTS was
observed. In addition, behavioral reactions were observed that
indicated that animals can learn behaviors that effectively mitigate
noise exposures (although exposure patterns must be learned, which is
less likely in wild animals than for the captive animals considered in
the study). The authors note that the failure to induce more
significant auditory effects was likely due to the intermittent nature
of exposure, the relatively low peak pressure produced by the acoustic
source, and the low-frequency energy in airgun pulses as compared with
the frequency range of best sensitivity for dolphins and other mid-
frequency cetaceans. For pinnipeds in water, measurements of TTS are
limited to harbor seals, elephant seals, and California sea lions
(summarized in Finneran, 2015).
Marine mammal hearing plays a critical role in communication with
conspecifics and in 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 takes place
during a time when the animal is traveling through the open ocean,
where ambient noise is lower and there are not as many competing sounds
present. Alternatively, a larger amount and longer duration of TTS
sustained during a time when communication is critical for successful
mother/calf interactions could have more serious impacts if it were in
the same frequency band as the necessary vocalizations and of a
severity that impeded communication. The fact that animals exposed to
high levels of sound that would be expected to result in this
physiological response would also be expected to have behavioral
responses of a comparatively more severe or sustained nature is
potentially more significant than simple existence of a TTS. However,
it is important to note that TTS could occur due to longer exposures to
sound at lower levels so that a behavioral response may not be
elicited.
Depending on the degree and frequency range, the effects of PTS on
an animal could also range in severity, although it is considered
generally more serious than TTS because it is a permanent condition. Of
note, reduced hearing sensitivity as a simple function of aging has
been observed in marine mammals, as well as humans and other taxa
(Southall et al., 2007), so we can infer that strategies exist for
coping with this condition to some degree, though likely not without
some cost to the animal.

Acoustically Mediated Bubble Growth and Other Pressure-Related Injury

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 (in combination with the
source levels) of sonar pings 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

[[Page 10998]]

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; Cox et al., 2006; Rommel et al., 2006). 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). 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 (Rommel et al., 2006). 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
relatively vulnerable to MF/HF sonar exposures.
In 2009, Hooker et al. tested two mathematical models to predict
blood and tissue tension N2 (PN2) using field data from
three beaked whale species: Northern bottlenose whales, Cuvier's beaked
whales, and Blainville's beaked whales. The researchers aimed to
determine if physiology (body mass, diving lung volume, and dive
response) or dive behavior (dive depth and duration, changes in ascent
rate, and diel behavior) would lead to differences in PN2
levels and thereby decompression sickness risk between species.
In their study, they compared results for previously published time
depth recorder data (Hooker and Baird, 1999; Baird et al., 2006, 2008)
from Cuvier's beaked whale, Blainville's beaked whale, and northern
bottlenose whale. They reported that diving lung volume and extent of
the dive response had a large effect on end-dive PN2. Also,
results showed that dive profiles had a larger influence on end-dive
PN2 than body mass differences between species. Despite diel
changes (i.e., variation that occurs regularly every day or most days)
in dive behavior, PN2 levels showed no consistent trend.
Model output suggested that all three species live with tissue
PN2 levels that would cause a significant proportion of
decompression sickness cases in terrestrial mammals. The authors
concluded that the dive behavior of Cuvier's beaked whale was different
from both Blainville's beaked whale, and northern bottlenose whale, and
resulted in higher predicted tissue and blood N2 levels (Hooker et al.,
2009) and suggested that the prevalence of Cuvier's beaked whales
stranding after naval sonar exercises could be explained by either a
higher abundance of this species in the affected areas or by possible
species differences in behavior and/or physiology related to MF active
sonar (Hooker et al., 2009).
Bernaldo de Quiros et al. (2012) showed that, among stranded
whales, deep diving species of whales had higher abundances of gas
bubbles compared to shallow diving species. Kvadsheim et al. (2012)
estimated blood and tissue PN2 levels in species
representing shallow, intermediate, deep diving cetaceans following
behavioral responses to sonar and their comparisons found that deep
diving species had higher end-dive blood and tissue N2
levels, indicating a higher risk of developing gas bubble emboli
compared with shallow diving species. Fahlmann et al. (2014) evaluated
dive data recorded from sperm, killer, long-finned pilot, Blainville's
beaked and Cuvier's beaked whales before and during exposure to low, as
defined by the authors, (1-2 kHz) and mid (2-7 kHz) frequency active
sonar in an attempt to determine if either differences in dive behavior
or physiological responses to sonar are plausible risk factors for
bubble formation. The authors suggested that CO2 may
initiate bubble formation and growth, while elevated levels of
N2 may be important for continued bubble growth. The authors
also suggest that if CO2 plays an important role in bubble
formation, a cetacean escaping a sound source may experience increased
metabolic rate, CO2 production, and alteration in cardiac
output, which could increase risk of gas bubble emboli. However, as
discussed in Kvadsheim et al. (2012), the actual observed behavioral
responses to sonar from the species in their study (sperm, killer,
long-finned pilot, Blainville's beaked, and Cuvier's beaked whales) did
not imply any significantly increased risk of decompression sickness
due to high levels of N2. Therefore, further information is
needed to understand the relationship between exposure to stimuli,
behavioral response (discussed in more detail below), elevated
N2 levels, and gas bubble emboli in marine mammals. The
hypotheses for gas bubble formation related to beaked whale strandings
is that beaked whales potentially have strong avoidance responses to MF
active sonars because they sound similar to their main

[[Page 10999]]

predator, the killer whale (Cox et al., 2006; Southall et al., 2007;
Zimmer and Tyack, 2007; Baird et al., 2008; Hooker et al., 2009).
Further investigation is needed to assess the potential validity of
these hypotheses.
To summarize, there is little data to support the potential for
strong, anthropogenic underwater sounds to cause non-auditory physical
effects in marine mammals. The available data do not allow
identification of a specific exposure level above which non-auditory
effects can be expected (Southall et al., 2007) or any meaningful
quantitative predictions of the numbers (if any) of marine mammals that
might be affected in these ways. Such effects, if they occur at all,
would be expected to be limited to situations where marine mammals were
exposed to high powered sounds at very close range over a prolonged
period of time, which is not expected to occur based on the speed of
the vessels operating sonar in combination with the speed and behavior
of marine mammals in the vicinity of sonar.
Acoustic Masking
Sound can disrupt behavior through masking, or interfering with, an
animal's ability to detect, recognize, or discriminate between acoustic
signals of interest (e.g., those used for intraspecific communication
and social interactions, prey detection, predator avoidance,
navigation) (Richardson et al., 1995; Erbe and Farmer, 2000; Tyack,
2000; Erbe et al., 2016). Masking occurs when the receipt of a sound is
interfered with by another coincident sound at similar frequencies and
at similar or higher intensity, and may occur whether the sound is
natural (e.g., snapping shrimp, wind, waves, precipitation) or
anthropogenic (e.g., shipping, sonar, seismic exploration) in origin.
The ability of a noise source to mask biologically important sounds
depends on the characteristics of both the noise source and the signal
of interest (e.g., signal-to-noise ratio, temporal variability,
direction), in relation to each other and to an animal's hearing
abilities (e.g., sensitivity, frequency range, critical ratios,
frequency discrimination, directional discrimination, age or TTS
hearing loss), and existing ambient noise and propagation conditions.
Masking these acoustic signals can disturb the behavior of individual
animals, groups of animals, or entire populations.
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.
Under certain circumstances, marine mammals experiencing
significant masking could also be impaired from maximizing their
performance fitness in survival and reproduction. Therefore, when the
coincident (masking) sound is man-made, it may be considered harassment
when disrupting or altering critical behaviors. It is important to
distinguish TTS and PTS, which persist after the sound exposure from
masking, which occurs during the sound exposure. Because masking
(without resulting in TS) is not associated with abnormal physiological
function, it is not considered a physiological effect, but rather a
potential behavioral effect.
The frequency range of the potentially masking sound is important
in determining any potential behavioral impacts. For example, low-
frequency signals may have less effect on high-frequency echolocation
sounds produced by odontocetes but are more likely to affect detection
of mysticete communication calls and other potentially important
natural sounds such as those produced by surf and some prey species.
The masking of communication signals by anthropogenic noise may be
considered as a reduction in the communication space of animals (e.g.,
Clark et al., 2009; Matthews et al., 2016) and may result in energetic
or other costs as animals change their vocalization behavior (e.g.,
Miller et al., 2000; Foote et al., 2004; Parks et al., 2007; Di Iorio
and Clark, 2009; Holt et al., 2009). Masking can be reduced in
situations where the signal and noise come from different directions
(Richardson et al., 1995), through amplitude modulation of the signal,
or through other compensatory behaviors (Houser and Moore, 2014).
Masking can be tested directly in captive species (e.g., Erbe, 2008),
but in wild populations it must be either modeled or inferred from
evidence of masking compensation. There are few studies addressing
real-world masking sounds likely to be experienced by marine mammals in
the wild (e.g., Branstetter et al., 2013).
Masking affects both senders and receivers of acoustic signals and
can potentially have long-term chronic effects on marine mammals at the
population level as well as at the individual level. Low-frequency
ambient sound levels have increased by as much as 20 dB (more than
three times in terms of SPL) in the world's ocean from pre-industrial
periods, with most of the increase from distant commercial shipping
(Hildebrand, 2009). All anthropogenic sound sources, but especially
chronic and lower-frequency signals (e.g., from commercial vessel
traffic), contribute to elevated ambient sound levels, thus
intensifying masking.
Richardson et al. (1995b) argued that the maximum radius of
influence of an industrial noise (including broadband low-frequency
sound transmission) on a marine mammal is the distance from the source
to the point at which the noise can barely be heard. This range is
determined by either the hearing sensitivity of the animal or the
background noise level present. Industrial masking is most likely to
affect some species' ability to detect communication calls and natural
sounds (i.e., surf noise, prey noise, etc.; Richardson et al., 1995).
The echolocation calls of toothed whales are subject to masking by
high-frequency sound. Human data indicate low-frequency sound can mask
high-frequency sounds (i.e., upward masking). Studies on captive
odontocetes by Au et al. (1974, 1985, 1993) indicate that some species
may use various processes to reduce masking effects (e.g., adjustments
in echolocation call intensity or frequency as a function of background
noise conditions). There is also evidence that the directional hearing
abilities of odontocetes are useful in reducing masking at the high-
frequencies these cetaceans use to echolocate, but not at the low-to-
moderate frequencies they use to communicate (Zaitseva et al., 1980). A
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. Holt et al. (2009) measured killer
whale call source levels and background noise levels in the one to 40
kHz band and reported that the whales increased their call source
levels by one dB SPL for every one dB SPL increase in background noise
level. Similarly, another study on St. Lawrence River belugas reported
a similar rate of increase in vocalization activity in response to
passing vessels (Scheifele et al., 2005).
Parks et al. (2007) provided evidence of behavioral changes in the
acoustic behaviors of the endangered North Atlantic right whale, and
the South Atlantic southern right whale, and suggested that these were
correlated to increased underwater noise levels. The study indicated
that right whales might shift the frequency band of their calls to
compensate for increased in-band background noise. The significance of

[[Page 11000]]

their result is the indication of potential species-wide behavioral
change in response to gradual, chronic increases in underwater ambient
noise. Di Iorio and Clark (2010) showed that blue whale calling rates
vary in association with seismic sparker survey activity, with whales
calling more on days with survey than on days without surveys. They
suggested that the whales called more during seismic survey periods as
a way to compensate for the elevated noise conditions.
Risch et al. (2012) documented reductions in humpback whale
vocalizations in the Stellwagen Bank National Marine Sanctuary
concurrent with transmissions of the Ocean Acoustic Waveguide Remote
Sensing (OAWRS) low-frequency fish sensor system at distances of 200 km
(124 mi) from the source. The recorded OAWRS produced a series of
frequency modulated pulses and the signal received levels ranged from
88 to 110 dB re: 1 [mu]Pa (Risch, et al., 2012). The authors
hypothesized that individuals did not leave the area but instead ceased
singing and noted that the duration and frequency range of the OAWRS
signals (a novel sound to the whales) were similar to those of natural
humpback whale song components used during mating (Risch et al., 2012).
Thus, the novelty of the sound to humpback whales in the AFTT Study
Area provided a compelling contextual probability for the observed
effects (Risch et al., 2012). However, the authors did not state or
imply that these changes had long-term effects on individual animals or
populations (Risch et al., 2012).
Redundancy and context can also facilitate detection of weak
signals. These phenomena may help marine mammals detect weak sounds in
the presence of natural or manmade noise. Most masking studies in
marine mammals present the test signal and the masking noise from the
same direction. The dominant background noise may be highly directional
if it comes from a particular anthropogenic source such as a ship or
industrial site. Directional hearing may significantly reduce the
masking effects of these sounds by improving the effective signal-to-
noise ratio.
The functional hearing ranges of mysticetes, odontocetes, and
pinnipeds underwater all overlap the frequencies of the sonar sources
used in the Navy's LFAS/MFAS/HFAS training and testing 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. Although hull-mounted sonar accounts
for a large portion of the area ensonified by Navy activities (because
of the source strength and number of hours it is 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 species 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 are not
directly known in all instances, like most other trade-offs animals
must make, some of these strategies probably come at a cost (Patricelli
et al., 2006). Shifting songs and calls to higher frequencies may also
impose energetic costs (Lambrechts, 1996). For example in birds,
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).
Stress Response
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.
According to Moberg (2000), 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 or sympathetic nervous systems; the system that
has received the most study has been the hypothalmus-pituitary-adrenal
system (also known as the HPA axis in mammals or the hypothalamus-
pituitary-interrenal axis in fish and some reptiles). Unlike stress
responses associated with the autonomic nervous system, virtually all
neuro-endocrine functions that are affected by stress--including immune
competence, reproduction, metabolism, and behavior--are regulated by
pituitary hormones. Stress-induced changes in the secretion of
pituitary hormones have been implicated in failed reproduction (Moberg,
1987; Rivier and Rivest, 1991), altered metabolism (Elasser et al.,
2000),

[[Page 11001]]

reduced immune competence (Blecha, 2000), and behavioral disturbance
(Moberg, 1987; Blecha, 2000). 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 a stress response diverts energy away from growth in
young animals, those animals may experience stunted growth. When 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 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).
There is limited information on the physiological responses of
marine mammals to anthropogenic sound exposure, as most observations
have been limited to short-term behavioral responses, which included
cessation of feeding, resting, or social interactions. 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). Various 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; Noren et al., 2009; Williams et al., 2006, 2009, 2014a,
2014b; 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 the proposed Navy training and testing activities in
the AFTT Study Area. For example, in an analysis of energy costs to
killer whales, Williams et al. (2009) suggested that whale-watching in
Canada's 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 (Washington state) 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. 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 (NRC, 2005). 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). Ultimately, the PCAD working
group issued a report (Cochrem, 2014) that summarized information
compiled from 239 papers or book chapters relating to stress in marine
mammals and concluded that stress responses can last from minutes to
hours and, while we typically focus on adverse stress responses, stress
response is part of a natural process to help animals adjust to changes
in their environment and can also be either neutral or beneficial.
Despite the lack of robust information on stress responses for
marine mammals exposed to anthropogenic sounds, 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 (e.g., 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
physiological stress responses of endangered Sonoran pronghorn to
military overflights. Smith et al. (2004a, 2004b) identified noise-
induced physiological transient stress responses in hearing-specialist
fish (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.

Behavioral Response/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 affects 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, DeRuiter et al., 2013). 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

[[Page 11002]]

factors such as the physical presence of a nearby vessel, may be more
relevant to the animal's response than the received level alone. For
example, Goldbogen et al. (2013) demonstrated that individual
behavioral state was critically important in determining response of
blue whales to sonar, noting that some individuals engaged in deep (>50
m) feeding behavior had greater dive responses than those in shallow
feeding or non-feeding conditions. Some blue whales in the Goldbogen et
al. (2013) study that were engaged in shallow feeding behavior
demonstrated no clear changes in diving or movement even when RLs were
high (~160 dB re 1[micro]Pa) for exposures to 3-4 kHz sonar signals,
while others showed a clear response at exposures at lower RLs of sonar
and pseudorandom noise.
Studies by DeRuiter et al. (2012) indicate that variability of
responses to acoustic stimuli depends not only on the species receiving
the sound and the sound source, but also on the social, behavioral, or
environmental contexts of exposure. Another study by DeRuiter et al.
(2013) examined behavioral responses of Cuvier's beaked whales to MF
sonar and found that whales responded strongly at low received levels
(RL of 89-127 dB re 1[micro]Pa) by ceasing normal fluking and
echolocation, swimming rapidly away, and extending both dive duration
and subsequent non-foraging intervals when the sound source was 3.4-9.5
km away. Importantly, this study also showed that whales exposed to a
similar range of RLs (78-106 dB re 1[micro]Pa) from distant sonar
exercises (118 km away) did not elicit such responses, suggesting that
context may moderate reactions.
Ellison et al. (2012) outlined an approach to assessing the effects
of sound on marine mammals that incorporates contextual-based factors.
The authors recommend considering not just the received level of sound,
but also the activity the animal is engaged in at the time the sound is
received, the nature and novelty of the sound (i.e., is this a new
sound from the animal's perspective), and the distance between the
sound source and the animal. They submit that this ``exposure
context,'' as described, greatly influences the type of behavioral
response exhibited by the animal. This sort of contextual information
is challenging to predict with accuracy for ongoing activities that
occur over large spatial and temporal expanses. However, distance is
one contextual factor for which data exist to quantitatively inform a
take estimate, and the new method for predicting Level B harassment
proposed in this document does consider distance to the source. Other
factors are often considered qualitatively in the analysis of the
likely consequences of sound exposure, where supporting information is
available.
Friedlaender et al. (2016) provided the first integration of direct
measures of prey distribution and density variables incorporated into
across-individual analyses of behavior responses of blue whales to
sonar, and demonstrated a 5-fold increase in the ability to quantify
variability in blue whale diving behavior. These results illustrate
that responses evaluated without such measurements for foraging animals
may be misleading, which again illustrates the context-dependent nature
of the probability of response.
Exposure of marine mammals to sound sources can result in, but is
not limited to, no response or any of the following observable
response: 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 (1995). More
recent reviews (Nowacek et al., 2007; DeRuiter et al., 2012 and 2013;
Ellison et al., 2012) address studies conducted since 1995 and focused
on observations where the received sound level of the exposed marine
mammal(s) was known or could be estimated. Southall et al. (2016)
states that results demonstrate that some individuals of different
species display clear yet varied responses, some of which have negative
implications, while others appear to tolerate high levels, and that
responses may not be fully predicable with simple acoustic exposure
metrics (e.g., received sound level). Rather, the authors state that
differences among species and individuals along with contextual aspects
of exposure (e.g., behavioral state) appear to affect response
probability. 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. Predictions
about 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, along with contextual factors.
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). If marine mammals respond to Navy vessels
that are 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). In
addition to the limited data on flight response for marine mammals,
there are examples of this response in terrestrial species. For
instance, the probability of flight responses in Dall's sheep Ovis
dalli dalli (Frid, 2001), hauled-out ringed seals Phoca hispida (Born
et al., 1999), Pacific brant (Branta bernicl nigricans), and Canada
geese (B. Canadensis) increased as a helicopter or fixed-wing aircraft
more directly approached groups of these animals (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).
Response to Predator
Evidence suggests that at least some marine mammals have the
ability to acoustically identify potential predators. For example,
harbor seals that reside in the coastal waters off British Columbia are
frequently targeted by certain groups of killer whales, but not others.
The seals discriminate between the calls of threatening and non-
threatening killer whales (Deecke et al., 2002), a capability that
should increase survivorship while reducing the energy required for
attending to and responding to all killer whale calls. The occurrence
of masking or hearing impairment provides a means by which marine
mammals may be prevented from responding to the acoustic cues produced
by their predators. Whether or not this is a

[[Page 11003]]

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.
Alteration of Diving or Movement
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. Lastly, as noted
previously, DeRuiter et al. (2013) noted that distance from a sound
source may moderate marine mammal reactions in their study of Cuvier's
beaked whales showing the whales swimming rapidly and silently away
when a sonar signal was 3.4-9.5 km away while showing no such reaction
to the same signal when the signal was 118 km away even though the RLs
were similar.
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). Visual tracking, passive acoustic monitoring,
and movement recording tags were used to quantify sperm whale behavior
prior to, during, and following exposure to airgun arrays at received
levels in the range 140-160 dB at distances of 7-13 km, following a
phase-in of sound intensity and full array exposures at 1-13 km (Madsen
et al., 2006a; Miller et al., 2009). Sperm whales did not exhibit
horizontal avoidance behavior at the surface. However, foraging
behavior may have been affected. The sperm whales exhibited 19 percent
less vocal (buzz) rate during full exposure relative to post exposure,
and the whale that was approached most closely had an extended resting
period and did not resume foraging until the airguns had ceased firing.
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 (Miller et al.,
2009). These data raise concerns that airgun surveys may impact
foraging behavior in sperm whales, although more data are required to
understand whether the differences were due to exposure or natural
variation in sperm whale behavior (Miller et al., 2009). 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 SPLs 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). However, Melc[oacute]n et al. (2012) were unable to
determine if suppression of low frequency calls reflected a change in
their feeding performance or abandonment of foraging behavior and
indicated that implications of the documented responses are unknown.
Further, 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).
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;
Southall et al., 2012b). 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

[[Page 11004]]

behavioral context, with some 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. Some 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. However,
for this to be true, we would have to assume that an individual whale
could not compensate for this lost feeding opportunity by either
immediately feeding at another location, by feeding shortly after
cessation of acoustic exposure, or by feeding at a later time. There is
no indication this is the case, particularly since unconsumed prey
would likely still be available in the environment in most cases
following the cessation of acoustic exposure.
Breathing
Variations in respiration naturally vary with different behaviors
and variations in respiration rate as a function of acoustic exposure
can be expected to co-occur with other behavioral reactions, such as a
flight response or an alteration in diving. However, respiration rates
in and of themselves may be representative of annoyance or an acute
stress response. Mean exhalation rates of gray whales at rest and while
diving were found to be unaffected by seismic surveys conducted
adjacent to the whale feeding grounds (Gailey et al., 2007). Studies
with captive harbor porpoises showed increased respiration rates upon
introduction of acoustic alarms (Kastelein et al., 2001; Kastelein et
al., 2006a) and emissions for underwater data transmission (Kastelein
et al., 2005). However, exposure of the same acoustic alarm to a
striped dolphin under the same conditions did not elicit a response
(Kastelein et al., 2006a), again highlighting the importance in
understanding species differences in the tolerance of underwater noise
when determining the potential for impacts resulting from anthropogenic
sound exposure.
Social Relationships
Social interactions between mammals can be affected by noise via
the disruption of communication signals or by the displacement of
individuals. Disruption of social relationships therefore depends on
the disruption of other behaviors (e.g., caused avoidance, masking,
etc.). Sperm whales responded to military sonar, apparently from a
submarine, by dispersing from social aggregations, moving away from the
sound source, remaining relatively silent, and becoming difficult to
approach (Watkins et al., 1985). In contrast, sperm whales in the
Mediterranean that were exposed to submarine sonar continued calling
(J. Gordon pers. comm. cited in Richardson et al., 1995). Long-finned
pilot whales exposed to three types of disturbance--playbacks of killer
whale sounds, naval sonar exposure, and tagging all resulted in
increased group sizes (Visser et al., 2016). In response to sonar,
pilot whales also spent more time at the surface with other members of
the group (Visser et al., 2016). However, social disruptions must be
considered in context of the relationships that are affected. While
some disruptions may not have deleterious effects, others, such as
long-term or repeated disruptions of mother/calf pairs or interruption
of mating behaviors, have the potential to affect the growth and
survival or reproductive effort/success of individuals.
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; Roland et al., 2012). 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.
Cerchio et al. (2014) used passive acoustic monitoring to document
the presence of singing humpback whales off the coast of northern
Angola and to opportunistically test for the effect of seismic survey
activity on the number of singing whales. Two recording units were
deployed between March and December 2008 in the offshore environment;
numbers of singers were counted every hour. Generalized Additive Mixed
Models were used to assess the effect of survey day (seasonality), hour
(diel variation), moon phase, and received levels of noise (measured
from a single pulse during each ten minute sampled period) on singer
number. The number of singers significantly decreased with increasing
received level of noise, suggesting that humpback whale communication
was disrupted to some extent by the survey activity.
Castellote et al. (2012) reported acoustic and behavioral changes
by fin whales in response to shipping and airgun noise. Acoustic
features of fin whale song notes recorded in the Mediterranean Sea and
northeast Atlantic Ocean were compared for areas with different
shipping noise levels and traffic intensities and during an airgun
survey. During the first 72 h of the survey, a steady decrease in song
received levels and bearings to singers indicated that whales moved
away from the acoustic source and out of the AFTT Study Area. This
displacement persisted for a time period well beyond the 10-day
duration of airgun activity, providing evidence that fin whales may
avoid an area for an extended period in the presence of increased
noise. The authors hypothesize that fin whale acoustic communication is
modified to compensate for increased background noise and that a
sensitization process may play a role in the observed temporary
displacement.
Seismic pulses at average received levels of 131 dB re 1
micropascal squared per second ([micro]Pa2-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 [micro]Pa peak-to-peak). Blackwell et al.
(2013) found that bowhead whale call rates dropped significantly at
onset of airgun use at sites with a median distance of 41-45 km from
the survey.

[[Page 11005]]

Blackwell et al. (2015) expanded this analysis to show that whales
actually increased calling rates as soon as airgun signals were
detectable before ultimately decreasing calling rates at higher
received levels (i.e., 10-minute cSEL of ~127 dB). Overall, these
results suggest that bowhead whales may adjust their vocal output in an
effort to compensate for noise before ceasing vocalization effort and
ultimately deflecting from the acoustic source (Blackwell et al., 2013,
2015). Captive bottlenose dolphins sometimes vocalized after an
exposure to impulse sound from a seismic watergun (Finneran et al.,
2010a). These studies demonstrate that even low levels of noise
received far from the noise source can induce behavioral responses.
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. Avoidance 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.
However, longer term displacement is possible and 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). Gray whales have been
reported deflecting from customary migratory paths in order to avoid
noise from airgun surveys (Malme et al., 1984). Humpback whales showed
avoidance behavior in the presence of an active airgun array during
observational studies and controlled exposure experiments in western
Australia (McCauley et al., 2000a).
In 1998, the Navy conducted a Low Frequency Sonar Scientific
Research Program (LFS SRP) specifically to study behavioral responses
of several species of marine mammals to exposure to LF sound, including
one phase that focused on the behavior of gray whales to low frequency
sound signals. The objective of this phase of the LFS SRP was to
determine whether migrating gray whales respond more strongly to
received levels (RL), sound gradient, or distance from the source, and
to compare whale avoidance responses to an LF source in the center of
the migration corridor versus in the offshore portion of the migration
corridor. A single source was used to broadcast LFA sonar sounds at RLs
of 170-178 dB re 1[micro]Pa. The Navy reported that the whales showed
some avoidance responses when the source was moored one mile (1.8 km)
offshore, and located within in the migration path, but the whales
returned to their migration path when they were a few kilometers beyond
the source. When the source was moored two miles (3.7 km) offshore,
responses were much less even when the source level was increased to
achieve the same RLs in the middle of the migration corridor as whales
received when the source was located within the migration corridor
(Clark et al., 1999). In addition, the researchers noted that the
offshore whales did not seem to avoid the louder offshore source.
Also during the LFS SRP, researchers sighted numerous odontocete
and pinniped species in the vicinity of the sound exposure tests with
LFA sonar. The MF and HF hearing specialists present in the AFTT Study
Area showed no immediately obvious responses or changes in sighting
rates as a function of source conditions. Consequently, the researchers
concluded that none of these species had any obvious behavioral
reaction to LFA sonar signals at received levels similar to those that
produced only minor short-term behavioral responses in the baleen
whales (i.e., LF hearing specialists). Thus, for odontocetes, the
chances of injury and/or significant behavioral responses to LFA sonar
for AFTT would be low given the MF/HF specialists' observed lack of
response to LFA sounds during the LFS SRP and due to the MF/HF
frequencies to which these animals are adapted to hear (Clark and
Southall, 2009).
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 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, where killer whales
cooperatively herd fish schools into a tight ball towards the surface
and feed on the fish which have been stunned by tailslaps and
subsurface feeding (Simila, 1997), 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 killer whales
were consistent with the results of other studies.
Southall et al. (2007) 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

[[Page 11006]]

data were reviewed and sometimes used for qualitative illustration, but
no quantitative criteria were recommended for behavioral responses. 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. LFAS/MFAS/HFAS are
considered non-pulse sounds. 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 following paragraphs
below).
The studies that address responses of low-frequency cetaceans to
non-pulse sounds include data gathered in the field and related to
several types of sound sources (of varying similarity to MFAS/HFAS)
including: vessel noise, drilling and machinery playback, low-frequency
M-sequences (sine wave with multiple phase reversals) playback,
tactical low-frequency active sonar playback, drill ships, Acoustic
Thermometry of Ocean Climate (ATOC) source, and non-pulse playbacks.
These studies generally indicate no (or very limited) responses to
received levels in the 90 to 120 dB re: 1 [micro]Pa range and an
increasing likelihood of avoidance and other behavioral effects in the
120 to 160 dB re: 1 [micro]Pa 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 re: 1 [micro]Pa, while in other cases these
responses were not seen in the 120 to 150 dB re: 1 [micro]Pa 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
re: 1 [micro]Pa), at least for initial exposures. All recorded
exposures above 140 dB re: 1 [micro]Pa 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 are no
data to indicate whether other high frequency cetaceans are as
sensitive to anthropogenic sound as harbor porpoises.
The studies that address the responses of pinnipeds in water to
non-impulsive sounds include data gathered both in the field and the
laboratory and related to several different sound sources 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 re: 1 [micro]Pa generally do not result in strong behavioral
responses in pinnipeds in water, but no data exist at higher received
levels.
In 2007, the first in a series of behavioral response studies (BRS)
on deep diving odontocetes conducted by NMFS, Navy, and other
scientists showed one Blainville's beaked whale 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 MF 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
was manifested by an adaptive movement away from a sound source. This
response was observed irrespective of whether the signal transmitted
was within the band width of MFAS, which suggests that beaked whales
may not respond to the specific sound signatures. Instead, they may be
sensitive to any pulsed sound from a point source in this frequency
range of the MF active sonar transmission. The response to such stimuli
appears to involve the beaked whale increasing the distance between it
and the sound source. Overall the results from the 2007-2008 study
conducted showed a change in diving behavior of the Blainville's beaked
whale to playback of MFAS and predator sounds (Boyd et al., 2008;
Southall et al. 2009; Tyack et al., 2011).
Stimpert et al. (2014) tagged a Baird's beaked whale, which was
subsequently exposed to simulated MFAS. Received levels of sonar on the
tag increased to a maximum of 138 dB re 1[mu]Pa, which occurred during
the first exposure dive. Some sonar received levels could not be
measured due to flow noise and surface noise on the tag.
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 MFAS during the 2010 and 2011 field
seasons of the southern California behavioral response study. The 2011
whale was also incidentally exposed to MFAS from a distant naval
exercise. Received levels from the MFAS 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

[[Page 11007]]

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. Specifically, this result suggests that
caution is needed when using marine mammal response data collected from
smaller, nearer sound sources to predict at what received levels
animals may respond to larger sound sources that are significantly
farther away--as the distance of the source appears to be an important
contextual variable and animals may be less responsive to sources at
notably greater distances. 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 (Boyd et al.,
2008; Southall et al., 2009; Tyack et al., 2011). 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 two hours after MF 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 MFAS playback was observed on one occasion (Miller et al.,
2011; 2012). Miller et al. (2012) noted that this single observed
mother-calf separation was unusual for several reasons, including the
fact that the experiment was conducted in an unusually narrow fjord
roughly one km wide and that the sonar exposure was started unusually
close to the pod including the calf. Both of these factors could have
contributed to calf separation. 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).
In the 2010 BRS study, researchers again used controlled exposure
experiments (CEE) to carefully measure behavioral responses of
individual animals to sound exposures of MF active sonar and pseudo-
random noise. For each sound type, some exposures were conducted when
animals were in a surface feeding (approximately 164 ft (50 m) or less)
and/or socializing behavioral state and others while animals were in a
deep feeding (greater than 164 ft (50 m)) and/or traveling mode. The
researchers conducted the largest number of CEEs on blue whales (n =
19) and of these, 11 CEEs involved exposure to the MF active sonar
sound type. For the majority of CEE transmissions of either sound type,
they noted few obvious behavioral responses detected either by the
visual observers or on initial inspection of the tag data. The
researchers observed that throughout the CEE transmissions, up to the
highest received sound level (absolute RMS value approximately 160 dB
re: 1[mu]Pa with signal-to-noise ratio values over 60 dB), two blue
whales continued surface feeding behavior and remained at a range of
around 3,820 ft (1,000 m) from the sound source (Southall et al.,
2011). In contrast, another blue whale (later in the day and greater
than 11.5 mi (18.5 km; 10 nmi) from the first CEE location) exposed to
the same stimulus (MFA) while engaged in a deep feeding/travel state
exhibited a different response. In that case, the blue whale responded
almost immediately following the start of sound transmissions when
received sounds were just above ambient background levels (Southall et
al., 2011). The authors note that this kind of temporary avoidance
behavior was not evident in any of the nine CEEs involving blue whales
engaged in surface feeding or social behaviors, but was observed in
three of the ten CEEs for blue whales in deep feeding/travel behavioral
modes (one involving MFA sonar; two involving pseudo-random noise)
(Southall et al., 2011). The results of this study, as well as the
results of the DeRuiter et al. (2013) study of Cuvier's beaked whales
discussed above, further illustrate the importance of behavioral
context in understanding and predicting behavioral responses.
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; Miller et
al., 2012; Southall et al., 2011, 2012a, 2012b, 2013, 2014; Tyack et
al., 2011). In the Bahamas, Blainville's beaked whales located on the
instrumented 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.
Southall et al. (2016) indicates that results from Tyack et al.
(2011); Miller et al. (2015), Stimpert et al. (2014), and DeRuiter et
al. (2013) beaked whale studies all demonstrate clear, strong, and
pronounced but varied behavioral changes including sustained avoidance
with associated energetic swimming and cessation of feeding behavior at
quite low received levels (~100 to 135 dB re 1Pa) for exposures to
simulated or active MF military sonars (1 to 8 kHz) with sound sources
approximately 2 to 5 km away.
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 [micro]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 [micro]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
[micro]Pa, and by 90 percent of animals at 190 dB re 1 [micro]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 11008]]

Humpback whales showed avoidance behavior at ranges of five to
eight km from a seismic array during observational studies and
controlled exposure experiments in western Australia (McCauley, 1998;
Todd et al., 1996). Todd 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.
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.
Continued Pre-disturbance Behavior and Habituation
Under some circumstances, some of the individual marine mammals
that are exposed to active sonar transmissions will continue their
normal behavioral activities. In other circumstances, individual
animals will respond to sonar transmissions at lower received levels
and move to avoid additional exposure or exposures at higher received
levels (Richardson et al., 1995).
It is difficult to distinguish between animals that continue their
pre-disturbance behavior without stress responses, animals that
continue their behavior but experience stress responses (that is,
animals that cope with disturbance), and animals that habituate to
disturbance (that is, they may have experienced low-level stress
responses initially, but those responses abated over time). Watkins
(1986) reviewed data on the behavioral reactions of fin, humpback,
right and minke whales that were exposed to continuous, broadband low-
frequency shipping and industrial noise in Cape Cod Bay. He concluded
that underwater sound was the primary cause of behavioral reactions in
these species of whales and that the whales responded behaviorally to
acoustic stimuli within their respective hearing ranges. Watkins also
noted that whales showed the strongest behavioral reactions to sounds
in the 15 Hz to 28 kHz range, although negative reactions (avoidance,
interruptions in vocalizations, etc.) were generally associated with
sounds that were either unexpected, too loud, suddenly louder or
different, or perceived as being associated with a potential threat
(such as an approaching ship on a collision course). In particular,
whales seemed to react negatively when they were within 100 m of the
source or when received levels increased suddenly in excess of 12 dB
relative to ambient sounds. At other times, the whales ignored the
source of the signal and all four species habituated to these sounds.
Nevertheless, Watkins concluded that whales ignored most sounds in the
background of ambient noise, including sounds from distant human
activities even though these sounds may have had considerable energies
at frequencies well within the whales' range of hearing. Further, he
noted that of the whales observed, fin whales were the most sensitive
of the four species, followed by humpback whales; right whales were the
least likely to be disturbed and generally did not react to low-
amplitude engine noise. By the end of his period of study, Watkins
(1986) concluded that fin and humpback whales have generally habituated
to the continuous and broad-band noise of Cape Cod Bay while right
whales did not appear to change their response. As mentioned above,
animals that habituate to a particular disturbance may have experienced
low-level stress responses initially, but those responses abated over
time. In most cases, this likely means a lessened immediate potential
effect from a disturbance. However, there is cause for concern where
the habituation occurs in a potentially more harmful situation. For
example, animals may become more vulnerable to vessel strikes once they
habituate to vessel traffic (Swingle et al., 1993; Wiley et al., 1995).
Aicken et al. (2005) monitored the behavioral responses of marine
mammals to a new low-frequency active sonar system used by the British
Navy (the United States Navy considers this to be a mid-frequency
source as it operates at frequencies greater than 1,000 Hz). During
those trials, fin whales, sperm whales, Sowerby's beaked whales, long-
finned pilot whales, Atlantic white-sided dolphins, and common
bottlenose dolphins were observed and their vocalizations were
recorded. These monitoring studies detected no evidence of behavioral
responses that the investigators could attribute to exposure to the
low-frequency active sonar during these trials.

Explosive 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). Intestinal walls can bruise
or rupture, with subsequent hemorrhage and escape of gut contents into
the body cavity. Less severe gastrointestinal tract injuries include
contusions, petechiae (small red or purple spots caused by bleeding in
the skin), and slight hemorrhaging (Yelverton et al., 1973).
Because the ears are the most sensitive to pressure, they are the
organs most sensitive to injury (Ketten, 2000). Sound-related damage
associated with sound energy from detonations can be theoretically
distinct from injury from the shock wave, particularly farther from the
explosion. If a noise is audible to an animal, it has the potential to
damage the animal's hearing by causing decreased sensitivity (Ketten,
1995). 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

[[Page 11009]]

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).

Further Potential Effects of Behavioral Disturbance on Marine Mammal
Fitness

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 are few quantitative marine mammal data 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. Several authors have reported that
disturbance stimuli may cause animals to abandon nesting and foraging
sites (Sutherland and Crockford, 1993); may cause animals to increase
their activity levels and suffer premature deaths or reduced
reproductive success when their energy expenditures exceed their energy
budgets (Daan et al., 1996; Feare, 1976; Mullner et al., 2004); or may
cause animals to experience higher predation rates when they adopt
risk-prone foraging or migratory strategies (Frid and Dill, 2002). Each
of these studies addressed the consequences of animals shifting from
one behavioral state (e.g., resting or foraging) to another behavioral
state (e.g., avoidance or escape behavior) because of human disturbance
or disturbance stimuli.
One consequence of behavioral avoidance results in the altered
energetic expenditure of marine mammals because energy is required to
move and avoid surface vessels or the sound field associated with
active sonar (Frid and Dill, 2002). Most animals can avoid that
energetic cost by swimming away at slow speeds or speeds that minimize
the cost of transport (Miksis-Olds, 2006), as has been demonstrated in
Florida manatees (Miksis-Olds, 2006).
Those energetic costs increase, however, when animals shift from a
resting state, which is designed to conserve an animal's energy, to an
active state that consumes energy the animal would have conserved had
it not been disturbed. Marine mammals that have been disturbed by
anthropogenic noise and vessel approaches are commonly reported to
shift from resting to active behavioral states, which would imply that
they incur an energy cost.
Morete et al., (2007) reported that undisturbed humpback whale cows
that were accompanied by their calves were frequently observed resting
while their calves circled them (milling). When vessels approached, the
amount of time cows and calves spent resting and milling, respectively,
declined significantly. These results are similar to those reported by
Scheidat et al. (2004) for the humpback whales they observed off the
coast of Ecuador.
Constantine and Brunton (2001) reported that bottlenose dolphins in
the Bay of Islands, New Zealand engaged in resting behavior just five
percent of the time when vessels were within 300 m, compared with 83
percent of the time when vessels were not present. However, Heenehan et
al. (2016) report that results of a study of the response of Hawaiian
spinner dolphins to human disturbance suggest that the key factor is
not the sheer presence or magnitude of human activities, but rather the
directed interactions and dolphin-focused activities that elicit
responses from dolphins at rest. This information again illustrates the
importance of context in regard to whether an animal will respond to a
stimulus. Miksis-Olds (2006) and Miksis-Olds et al. (2005) reported
that Florida manatees in Sarasota Bay, Florida, reduced the amount of
time they spent milling and increased the amount of time they spent
feeding when background noise levels increased. Although the acute
costs of these changes in behavior are not likely to exceed an animal's
ability to compensate, the chronic costs of these behavioral shifts are
uncertain.
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
(e.g., multiple surface vessels), or when they co-occur with times that
an animal perceives increased risk (e.g., 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. An example of this concept
with terrestrial species involved bighorn sheep and Dall's sheep, which
dedicated more time being vigilant, and less time resting or foraging,
when aircraft made direct approaches over them (Frid, 2001; Stockwell
et al., 1991). Vigilance has also been documented in pinnipeds at haul
out sites where resting may be disturbed when seals become alerted and/
or flush into the water due to a variety of disturbances, which may be
anthropogenic (noise and/or visual stimuli) or due to other natural
causes such as other pinnipeds (Richardson et al., 1995; Southall et
al., 2007; VanBlaricom, 2010; and Lozano and Hente, 2014).
Several authors have established that long-term and intense
disturbance stimuli can cause population declines by reducing the
physical condition of individuals that have been disturbed, followed by
reduced reproductive success, reduced survival, or both (Daan et al.,
1996; Madsen, 1994; White, 1985). For example, Madsen (1994) reported
that pink-footed geese (Anser brachyrhynchus) in undisturbed habitat
gained body mass and had about a 46 percent reproductive success 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 (Odocoileus
hemionus) disturbed by all-terrain vehicles (Yarmoloy et al.,

[[Page 11010]]

1988), caribou (Rangifer tarandus caribou) disturbed by seismic
exploration blasts (Bradshaw et al., 1998), and caribou disturbed by
low-elevation military jet fights (Luick et al., 1996, Harrington and
Veitch, 1992). Similarly, a study of elk (Cervus elaphus) that were
disturbed experimentally by pedestrians concluded that the ratio of
young to mothers was inversely related to disturbance rate (Phillips
and Alldredge, 2000).
The primary mechanism by which increased vigilance and disturbance
appear to affect the fitness of individual animals is by disrupting an
animal's time budget and, as a result, reducing the time they might
spend foraging and resting (which increases an animal's activity rate
and energy demand while decreasing their caloric intake/energy).
Ridgway et al. (2006) reported that increased vigilance in bottlenose
dolphins exposed to sound over a five-day period in open-air, open-
water enclosures in San Diego Bay did not cause any sleep deprivation
or stress effects such as changes in cortisol or epinephrine levels. An
example of this concept with terrestrial species involved a study of
grizzly bears (Ursus horribilis) reported that bears disturbed by
hikers reduced their energy intake by an average of 12 kilocalories/min
(50.2 x 103kiloJoules/min), and spent energy fleeing or acting
aggressively toward hikers (White et al., 1999).
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). Behavioral reactions to noise exposure (such as disruption of
critical life functions, displacement, or avoidance of important
habitat) are more likely to be significant for fitness if they last
more than one diel cycle or recur on subsequent days (Southall et al.,
2007). Consequently, a behavioral response lasting less than one day
and not recurring on subsequent days is not considered particularly
severe unless it could directly affect reproduction or survival
(Southall et al., 2007). It is important to note the difference between
behavioral reactions lasting or recurring over multiple days and
anthropogenic activities lasting or recurring over multiple days. For
example, just because an at-sea exercises last for multiple days does
not necessarily mean that individual animals will be exposed to those
exercises for multiple days or exposed in a manner that would result in
a sustained behavioral response.
In order to understand how the effects of activities may or may not
impact species and stocks 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-level effects. 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. In this
framework, 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; 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;
or they can have no effect to vital rates (New et al., 2014). In
addition to outlining this general framework and compiling the relevant
literature that supports it, authors 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 for the majority of species, they
are a critical first step towards being able to quantify the likelihood
of a population level effect.

Stranding and Mortality

The definition for a stranding under title IV of the MMPA 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 is unable
to return to the water; (ii) on a beach or shore of the United States
and, although able to return to the water, is in need of apparent
medical attention; or (iii) in the waters under the jurisdiction of the
United States (including any navigable waters), but is unable to return
to its natural habitat under its own power or without assistance (16
U.S.C. 1421h).
Marine mammals are known to strand for a variety of reasons, such
as infectious agents, biotoxicosis, starvation, fishery interaction,
ship strike, unusual oceanographic or weather events, sound exposure,
or combinations of these stressors sustained concurrently or in series.
However, the cause or causes of most strandings are unknown (Geraci et
al., 1976; Eaton, 1979, Odell et al., 1980; Best, 1982). Numerous
studies suggest that the physiology, behavior, habitat

[[Page 11011]]

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).
Several sources have published lists of mass stranding events of
cetaceans in an attempt to identify relationships between those
stranding events and military active sonar (Hildebrand, 2004; IWC,
2005; Taylor et al., 2004). For example, based on a review of mass
stranding events around the world between consisting of two or more
individuals of Cuvier's beaked whales records between the International
Whaling Commission (2005) show that a quarter (9 of 41) were associated
with concurrent naval patrol, explosion, maneuvers, or MFAS. However,
one stranding event was contemporaneous with and reasonably associated
spatially with the use of seismic airguns. This event occurred in the
Gulf of California, coincident with seismic reflection profiling by the
R/V Maurice Ewing operated by Columbia University's Lamont-Doherty
Earth Observatory and involved two Cuvier's beaked whales (Hildebrand,
2004). The vessel had been firing an array of 20 airguns with a total
volume of 8,500 in3 (Hildebrand, 2004; Taylor et al., 2004).
Most of the stranding events reviewed by the IWC 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.
Strandings Associated With Impulsive Sound

Silver Strand

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 five 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 Oceanside, California (3 days later
and approximately 68 km north of the detonation, 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 impulsive 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 underwater explosives
training and other training events are presented in the Proposed
Mitigation section.

Kyle of Durness, Scotland

On July 22, 2011 a mass stranding event involving long-finned pilot
whales occurred at Kyle of Durness, Scotland. An investigation by
Brownlow et al. (2015) considered unexploded ordnance detonation
activities at a Ministry of Defense bombing range, conducted by the
Royal Navy prior to and during the strandings, as a plausible
contributing factor in the mass stranding event. While Brownlow et al.
(2015) concluded that the serial detonations of underwater ordnance
were an influential factor in the mass stranding event (along with
presence of a potentially compromised animal and navigational error in
a topographically complex region) they also suggest that mitigation
measures--which included observations from a zodiac only and by
personnel not experienced in marine mammal observation, among other
deficiencies--were likely insufficient to assess if cetaceans were in
the vicinity of the detonations. The authors also cite information from
the Ministry of Defense indicating ``an extraordinarily high level of
activity'' (i.e., frequency and intensity of underwater explosions) on
the range in the days leading up to the stranding.
Strandings Associated With Active Sonar
Over the past 21 years, there have been five stranding events
coincident with military MF active 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). NMFS refers the reader to DoN (2013) for a report on these
strandings associated with Navy sonar activities; Cox et al. (2006) for
a summary of common features shared by the strandings events in Greece
(1996), Bahamas (2000), Madeira (2000), and Canary Islands (2002); and
Fernandez et al., (2005) for an additional summary of the Canary
Islands 2002 stranding event. 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 Hanalei Bay stranding. A number of other
stranding events coincident with the operation of MFAS, 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

[[Page 11012]]

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 will abide by
the Notification and Reporting Plan, which sets out notification,
reporting, and other requirements when dead, injured, or stranding
whales are detected in certain circumstances.

Greece (1996)

Twelve Cuvier's beaked whales stranded atypically (in both time and
space) along a 38.2-km strand of the Kyparissiakos Gulf coast on May 12
and 13, 1996 (Frantzis, 1998). From May 11 through May 15, the North
Atlantic Treaty Organization (NATO) research vessel Alliance was
conducting sonar tests with signals of 600 Hz and 3 kHz and source
levels of 228 and 226 dB re: 1[mu]Pa, respectively (D'Amico and
Verboom, 1998; D'Spain et al., 2006). The timing and location of the
testing encompassed the time and location of the strandings (Frantzis,
1998).
Necropsies of eight of the animals were performed but were limited
to basic external examination and sampling of stomach contents, blood,
and skin. No ears or organs were collected, and no histological samples
were preserved. No apparent abnormalities or wounds were found.
Examination of photos of the animals, taken soon after their death,
revealed that the eyes of at least four of the individuals were
bleeding. Photos were taken soon after their death (Frantzis, 2004).
Stomach contents contained the flesh of cephalopods, indicating that
feeding had recently taken place (Frantzis, 1998).
All available information regarding the conditions associated with
this stranding event were compiled, and many potential causes were
examined including major pollution events, prominent tectonic activity,
unusual physical or meteorological events, magnetic anomalies,
epizootics, and conventional military activities (International Council
for the Exploration of the Sea, 2005a). However, none of these
potential causes coincided in time or space with the mass stranding, or
could explain its characteristics (International Council for the
Exploration of the Sea, 2005a). The robust condition of the animals,
plus the recent stomach contents, is inconsistent with pathogenic
causes. In addition, environmental causes can be ruled out as there
were no unusual environmental circumstances or events before or during
this time period and within the general proximity (Frantzis, 2004).
Because of the rarity of this mass stranding of Cuvier's beaked
whales in the Kyparissiakos Gulf (first one in historical records), 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

[[Page 11013]]

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, Portugal (2000)

From May 10-14, 2000, three Cuvier's beaked whales were found
atypically stranded on two islands in the Madeira archipelago, Portugal
(Cox et al., 2006). A fourth animal was reported floating in the
Madeiran waters by fisherman but did not come ashore (Woods Hole
Oceanographic Institution, 2005). Joint NATO amphibious training
peacekeeping exercises involving participants from 17 countries and 80
warships, took place in Portugal during May 2-15, 2000.
The bodies of the three stranded whales were examined post mortem
(Woods Hole Oceanographic Institution, 2005), though only one of the
stranded whales was fresh enough (24 hours after stranding) to be
necropsied (Cox et al., 2006). Results from the necropsy revealed
evidence of hemorrhage and congestion in the right lung and both
kidneys (Cox et al., 2006). There was also evidence of intercochlear
and intracranial hemorrhage similar to that which was observed in the
whales that stranded in the Bahamas event (Cox et al., 2006). There
were no signs of blunt trauma, and no major fractures (Woods Hole
Oceanographic Institution, 2005). The cranial sinuses and airways were
found to be clear with little or no fluid deposition, which may
indicate good preservation of tissues (Woods Hole Oceanographic
Institution, 2005).
Several observations on the Madeira stranded beaked whales, such as
the pattern of injury to the auditory system, are the same as those
observed in the Bahamas strandings. Blood in and around the eyes,
kidney lesions, pleural hemorrhages, and congestion in the lungs are
particularly consistent with the pathologies from the whales stranded
in the Bahamas, and are consistent with stress and pressure related
trauma. The similarities in pathology and stranding patterns between
these two events suggest that a similar pressure event may have
precipitated or contributed to the strandings at both sites (Woods Hole
Oceanographic Institution, 2005).
Even though no definitive causal link can be made between the
stranding event and naval exercises, certain conditions may have
existed in the exercise area that, in their aggregate, may have
contributed to the marine mammal strandings (Freitas, 2004): exercises
were conducted in areas of at least 547 fathoms (1,000 m) depth near a
shoreline where there is a rapid change in bathymetry on the order of
547 to 3,281 fathoms (1,000 to 6,000 m) occurring across a relatively
short horizontal distance (Freitas, 2004); multiple ships were
operating around Madeira, though it is not known if MFAS was used, and
the specifics of the sound sources used are unknown (Cox et al., 2006,
Freitas, 2004); and exercises took place in an area surrounded by
landmasses separated by less than 35 nmi (65 km) and at least 10 nmi
(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 four 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, 6 of them within 12 hours of
stranding (Fernandez et al., 2005). No pathogenic bacteria were
isolated from the carcasses (Jepson et al., 2003). The animals
displayed severe vascular congestion and hemorrhage especially around
the tissues in the jaw, ears, brain, and kidneys, displaying marked
disseminated microvascular hemorrhages associated with widespread fat
emboli (Jepson et al., 2003; International Council for Exploration of
the Sea, 2005a). Several organs contained intravascular bubbles,
although definitive evidence of gas embolism in vivo is difficult to
determine after death (Jepson et al., 2003). The livers of the
necropsied animals were the most consistently affected organ, which
contained macroscopic gas-filled cavities and had variable degrees of
fibrotic encapsulation. In some animals, cavitary lesions had
extensively replaced the normal tissue (Jepson et al., 2003). Stomachs
contained a large amount of fresh and undigested contents, suggesting a
rapid onset of disease and death (Fernandez et al., 2005). Head and
neck lymph nodes were enlarged and congested, and parasites were found
in the kidneys of all animals (Fernandez et al., 2005).
The association of NATO MFAS use close in space and time to the
beaked whale strandings, and the similarity between this stranding
event and previous beaked whale mass strandings coincident with sonar
use, suggests that a similar scenario and causative mechanism of
stranding may be shared between the events. Beaked whales stranded in
this event demonstrated brain and auditory system injuries,
hemorrhages, and congestion in multiple organs, similar to the
pathological findings of the Bahamas and Madeira stranding events. In
addition, the necropsy results of Canary Islands stranding event lead
to the hypothesis that the presence of disseminated and widespread gas
bubbles and fat emboli were indicative of nitrogen bubble formation,
similar to what might be expected in decompression sickness (Jepson et
al., 2003; Fern[aacute]ndez et al., 2005).

Hanalei Bay (2004)

On July 3 and 4, 2004, approximately 150 to 200 melon-headed whales
occupied the shallow waters of the Hanalei Bay, Kaua'i, Hawaii for over
28 hrs. Attendees of a canoe blessing observed the animals entering the
Bay in a single wave formation at 7 a.m. on July 3, 2004. The animals
were observed moving back into the shore from the mouth of the Bay at 9
a.m. The usually pelagic animals milled in the shallow bay and were
returned to deeper water with human assistance beginning at 9:30 a.m.
on July 4, 2004, and were out of sight by 10:30 a.m.
Only one animal, a calf, was known to have died following this
event. The animal was noted alive and alone in the Bay on the afternoon
of July 4, 2004, and was found dead in the Bay the morning of July 5,
2004. A full necropsy, magnetic resonance imaging, and computerized
tomography examination were performed on the calf

[[Page 11014]]

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 nine hours
total from 1:15 p.m. to 12:30 a.m.) as they approached from the south.
The potential for these transmissions to have triggered the whales'
movement into Hanalei Bay was investigated. Analyses with the
information available indicated that animals to the south and east of
Kaua'i could have detected active sonar transmissions on July 2, and
reached Hanalei Bay on or before 7 a.m. on July 3. However, data
limitations regarding the position of the whales prior to their arrival
in the Bay, the magnitude of sonar exposure, behavioral responses of
melon-headed whales to acoustic stimuli, and other possible relevant
factors preclude a conclusive finding regarding the role of sonar in
triggering this event. Propagation modeling suggests that transmissions
from sonar use during the July 3 exercise in the PMRF warning area may
have been detectable at the mouth of the Bay. If the animals responded
negatively to these signals, it may have contributed to their continued
presence in the Bay. The U.S. Navy ceased all active sonar
transmissions during exercises in this range on the afternoon of July
3. Subsequent to the cessation of sonar use, the animals were herded
out of the Bay.
While causation of this stranding event may never be unequivocally
determined, 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.
Spain (2006)
The Spanish Cetacean Society reported an atypical mass stranding of
four beaked whales that occurred January 26, 2006, on the southeast
coast of Spain, near Mojacar (Gulf of Vera) in the Western
Mediterranean Sea. According to the report, two of the whales were
discovered the evening of January 26 and were found to be still alive.
Two other whales were discovered during the day on January 27, but had
already died. The first three animals were located near the town of
Mojacar and the fourth animal was found dead, a few kilometers north of
the first three animals. From January 25-26, 2006, Standing NATO
Response Force Maritime Group Two (five of seven ships including one
U.S. ship under NATO Operational Control) had conducted active sonar
training against a Spanish submarine within 50 nmi (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

[[Page 11015]]

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).
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 two 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 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 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

[[Page 11016]]

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 could 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 could 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.
Strandings on the Atlantic Coast and the Gulf of Mexico
Stranding events, specifically UMEs that occurred on the Atlantic
Coast and the Gulf of Mexico (inclusive of the AFTT Study Area) were
previously discussed in the Description of Marine Mammals section.

Potential Effects of Vessel Strike

Vessel collisions with marine mammals, also referred to as vessel
strikes or ship strikes, can result in death or serious injury of the
animal. Wounds resulting from ship strike may include massive trauma,
hemorrhaging, broken bones, or propeller lacerations (Knowlton and
Kraus, 2001). 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.
Superficial strikes may not kill or result in the death of the animal.
These interactions are typically associated with large whales, which
are occasionally found draped across the bulbous bow of large
commercial ships upon arrival in port. Although smaller cetaceans are
more maneuverable in relation to large vessels than are large whales,
they may also be susceptible to strike. 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; Conn and
Silber, 2013). Impact forces increase with speed, as does the
probability of a strike at a given distance (Silber et al., 2010; Gende
et al., 2011).
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 NARW, 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. In an effort to reduce the number and severity of strikes of
the endangered NARW, NMFS implemented speed restrictions in 2008 (73 FR
60173; October 10, 2008). These restrictions require that vessels
greater than or equal to 65 ft (19.8 m) in length travel at less than
or equal to 10 knots (kn) near key port entrances and in certain areas
of right whale aggregation along the U.S. eastern seaboard. Conn and
Silber (2013) estimated that these restrictions reduced total ship
strike mortality risk levels by 80 to 90 percent. 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 or serious injury (Knowlton
and Kraus, 2001; Laist et al., 2001; Jensen and Silber, 2003; Pace and
Silber, 2005; 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).
In a separate study, Vanderlaan and Taggart (2007) analyzed the
probability of lethal mortality of large whales at a given speed,
showing that the greatest rate of change in the probability of a lethal
injury to a large whale as a function of vessel speed occurs between

[[Page 11017]]

8.6 and 15 kn. The chances of a lethal injury decline from
approximately 80 percent at 15 kn to approximately 20 percent at 8.6
kn. At speeds below 11.8 kn, the chances of lethal injury drop below 50
percent, while the probability asymptotically increases toward 100
percent above 15 kn.
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
percentage of Navy traffic relative to overall large shipping traffic
are very small (on the order of two percent) and therefore represent a
correspondingly smaller threat of potential ship strikes when compared
to commercial shipping.
Over a period of 18 years from 1995 to 2012 there have been a total
of 19 Navy vessel strikes in the AFTT Study Area. Eight of the strikes
resulted in a confirmed death; but in 11 of the 19 strikes, the fate of
the animal was unknown. It is possible that some of the 11 reported
strikes resulted in recoverable injury or were not marine mammals at
all, but another large marine species (e.g., basking shark). However,
it is prudent to consider that all of the strikes could have resulted
in the death of a marine mammal. The maximum number of strikes in any
given year was three strikes, which occurred in 2001 and 2004. The
highest average number of strikes over any five year period was two
strikes per year from 2001 to 2005. The average number of strikes for
the entire 18-year period is 1.055 strikes per year. From 2009-2016
there has been a total of three whale strikes reported in the AFTT
Study Area.
Between 2007 and 2009, the Navy developed and distributed
additional training, mitigation, and reporting tools to Navy operators
to improve marine mammal protection and to ensure compliance with
permit requirements. In 2007, the Navy implemented Marine Species
Awareness Training designed to improve effectiveness of visual
observation for marine resources including marine mammals. In
subsequent years, the Navy issued refined policy guidance on ship
strikes in order to collect the most accurate and detailed data
possible in response to a possible incident.

Marine Mammal Habitat

The Navy's proposed training and testing activities could
potentially affect marine mammal habitat through the introduction of
impacts to the prey species of marine mammals, acoustic habitat (sound
in the water column), water quality, and important habitat for marine
mammals. Each of these components was considered in the AFTT 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 AFTT DEIS/OEIS, NMFS has determined that the proposed
training and training activities would not have adverse or long-term
impacts on marine mammal habitat.
Effects to Prey
Sound may affect marine mammals through impacts on the abundance,
behavior, or distribution of prey species (e.g., crustaceans,
cephalopods, fish, zooplankton). Marine mammal prey varies by species,
season, and location and, for some, is not well documented. Here, we
describe studies regarding the effects of noise on known marine mammal
prey.
Fish utilize the soundscape and components of sound in their
environment to perform important functions such as foraging, predator
avoidance, mating, and spawning (e.g., Zelick et al., 1999; Fay, 2009).
Depending on their hearing anatomy and peripheral sensory structures,
which vary among species, fishes hear sounds using pressure and
particle motion sensitivity capabilities and detect the motion of
surrounding water (Fay et al., 2008). The potential effects of airgun
noise on fishes depends on the overlapping frequency range, distance
from the sound source, water depth of exposure, and species-specific
hearing sensitivity, anatomy, and physiology. Key impacts to fishes may
include behavioral responses, hearing damage, barotrauma (pressure-
related injuries), and mortality.
Fish react to sounds which are especially strong and/or
intermittent low-frequency sounds, and behavioral responses such as
flight or avoidance are the most likely effects. Short duration, sharp
sounds can cause overt or subtle changes in fish behavior and local
distribution. The reaction of fish to acoustic sources depends on the
physiological state of the fish, past exposures, motivation (e.g.,
feeding, spawning, migration), and other environmental factors.
Hastings and Popper (2005) identified several studies that suggest fish
may relocate to avoid certain areas of sound energy. Changes in
behavior of fish have been observed as a result of sound produced by
explosives, with effect intensified in areas of hard substrate (Wright,
1982). Stunning from pressure waves could also temporarily immobilize
fish, making them more susceptible to predation. Fish not killed or
driven from a location by an explosion might change their behavior,
feeding pattern, or distribution. The abundances of various fish and
invertebrates near the detonation point for explosives could be altered
for a few hours before animals from surrounding areas repopulate the
area; however, these populations would likely be replenished as waters
near the detonation point are mixed with adjacent waters. 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 fish populations would not be
expected. Several studies have demonstrated that airgun sounds might
affect the distribution and behavior of some fishes, potentially
impacting foraging opportunities or increasing energetic costs (e.g.,
Fewtrell and McCauley, 2012; Pearson et al., 1992; Skalski et al.,
1992; Santulli et al., 1999; Paxton et al., 2017).
Some studies have shown no or slight reaction to airgun sounds
(e.g., Pena et al., 2013; Wardle et al., 2001; Jorgenson and Gyselman,
2009; Cott et al., 2012). More commonly, though, the impacts of noise
on fish are temporary. Investigators reported significant, short-term
declines in commercial fishing catch rate of gadid fishes during and
for up to five days after survey operations, but the catch rate
subsequently returned to normal (Engas et al., 1996; Engas and
Lokkeborg, 2002); other studies have reported similar findings (Hassel
et al., 2004). However, even temporary effects to fish distribution
patterns can impact their ability to carry out important life-history
functions (Paxton et al., 2017).
SPLs of sufficient strength have been known to cause injury to fish
and fish mortality and, in some studies, fish auditory systems have
been damaged by airgun noise (McCauley et al., 2003; Popper et al.,
2005; Song et al., 2008). However, in most fish species, hair cells in
the ear continuously regenerate and loss of auditory function likely is
restored when damaged cells are replaced with new cells. Halvorsen et
al. (2012a) showed that a TTS of 4-6 dB was recoverable within 24 hours
for one species. Impacts would be most severe when the individual fish
is close to the source and when the duration of exposure is long. No
mortality occurred to fish in any of these studies.
Injury caused by barotrauma can range from slight to severe and can

[[Page 11018]]

cause death, and is most likely for fish with swim bladders. Barotrauma
injuries have been documented during controlled exposure to impact pile
driving (an impulsive noise source, as are explosives and airguns)
(Halvorsen et al., 2012b; Casper et al., 2013). For seismic surveys,
the sound source is constantly moving, and most fish would likely avoid
the sound source prior to receiving sound of sufficient intensity to
cause physiological or anatomical damage.
It is uncertain whether some permanent hearing loss over a part of
a fish's hearing range would have long-term consequences for that
individual. It is possible for fish to be injured or killed by an
explosion. Physical effects from pressure waves generated by underwater
sounds (e.g., underwater explosions) could potentially affect fish
within proximity of training or testing activities. The shock wave from
an underwater explosion is lethal to fish at close range, causing
massive organ and tissue damage and internal bleeding (Keevin & Hempen,
1997). At greater distance from the detonation point, the extent of
mortality or injury depends on a number of factors including fish size,
body shape, orientation, and species (Keevin & Hempen, 1997; Wright,
1982). At the same distance from the source, larger fish are generally
less susceptible to death or injury, elongated forms that are round in
cross-section are less at risk than deep-bodied forms, and fish
oriented sideways to the blast suffer the greatest impact (Edds-Walton
& Finneran, 2006; O'Keeffe, 1984; O'Keeffe & Young, 1984; Wiley et al.,
1981; Yelverton et al., 1975). Species with swim bladders have higher
mortality than those without them (Continental Shelf Associates Inc.,
2004; Goertner et al., 1994).
Invertebrates appear to be able to detect sounds (Pumphrey, 1950;
Frings and Frings, 1967) and are most sensitive to low-frequency sounds
(Packard et al., 1990; Budelmann and Williamson, 1994; Lovell et al.,
2005; Mooney et al., 2010). Available data suggest that cephalopods are
capable of sensing the particle motion of sounds and detect low
frequencies up to 1-1.5 kHz, depending on the species, and so are
likely to detect airgun noise (Kaifu et al., 2008; Hu et al., 2009;
Mooney et al., 2010; Samson et al., 2014). Cephalopods have a
specialized sensory organ inside the head called a statocyst that may
help an animal determine its position in space (orientation) and
maintain balance (Budelmann, 1992). Packard et al. (1990) showed that
cephalopods were sensitive to particle motion, not sound pressure, and
Mooney et al. (2010) demonstrated that squid statocysts act as an
accelerometer through which particle motion of the sound field can be
detected. Auditory injuries (lesions occurring on the statocyst sensory
hair cells) have been reported upon controlled exposure to low-
frequency sounds, suggesting that cephalopods are particularly
sensitive to low-frequency sound (Andre et al., 2011; Sole et al.,
2013). Behavioral responses, such as inking and jetting, have also been
reported upon exposure to low-frequency sound (McCauley et al., 2000b;
Samson et al., 2014).
Impacts to benthic communities from impulsive sound generated by
active acoustic sound sources are not well documented. There are no
published data that indicate whether threshold shift injuries or
effects of auditory masking occur in benthic invertebrates, and there
are little data to suggest whether sounds from seismic surveys would
have any substantial impact on invertebrate behavior (Hawkins et al.,
2014), though some studies have indicated showed no short-term or long-
term effects of airgun exposure (e.g., Andriguetto-Filho et al., 2005;
Payne et al., 2007; 2008; Boudreau et al., 2009). Exposure to airgun
signals was found to significantly increase mortality in scallops, in
addition to causing significant changes in behavioral patterns during
exposure (Day et al., 2017). However, the authors state that the
observed levels of mortality were not beyond naturally occurring rates.
There is little information concerning potential impacts of noise
on zooplankton populations. However, one recent study (McCauley et al.,
2017) investigated zooplankton abundance, diversity, and mortality
before and after exposure to airgun noise, finding that the exposure
resulted in significant depletion for more than half the taxa present
and that there were two to three times more dead zooplankton after
airgun exposure compared with controls for all taxa. The majority of
taxa present were copepods and cladocerans; for these taxa, the range
within which effects on abundance were detected was up to approximately
1.2 km. In order to have significant impacts on r-selected species such
as plankton, the spatial or temporal scale of impact must be large in
comparison with the ecosystem concerned (McCauley et al., 2017).
Therefore, the large scale of effect observed here is of concern--
particularly where repeated noise exposure is expected--and further
study is warranted.
Prey species exposed to sound might move away from the sound
source, experience TTS, experience masking of biologically relevant
sounds, or show no obvious direct effects. Mortality from decompression
injuries is possible in close proximity to a sound, but only limited
data on mortality in response to airgun noise exposure are available
(Hawkins et al., 2014). The most likely impacts for most prey species
in a given area would be temporary avoidance of the area. Surveys using
towed airgun arrays move through an area relatively quickly, limiting
exposure to multiple impulsive sounds. In all cases, sound levels would
return to ambient once a survey ends and the noise source is shut down
and, when exposure to sound ends, behavioral and/or physiological
responses are expected to end relatively quickly (McCauley et al.,
2000b). The duration of fish avoidance of a given area after survey
effort stops is unknown, but a rapid return to normal recruitment,
distribution, and behavior is anticipated. While the potential for
disruption of spawning aggregations or schools of important prey
species can be meaningful on a local scale, the mobile and temporary
nature of most surveys and the likelihood of temporary avoidance
behavior suggest that impacts would be minor.
Acoustic Habitat
Acoustic habitat is the soundscape--which encompasses all of the
sound present in a particular location and time, as a whole--when
considered from the perspective of the animals experiencing it. Animals
produce sound for, or listen for sounds produced by, conspecifics
(communication during feeding, mating, and other social activities),
other animals (finding prey or avoiding predators), and the physical
environment (finding suitable habitats, navigating). Together, sounds
made by animals and the geophysical environment (e.g., produced by
earthquakes, lightning, wind, rain, waves) make up the natural
contributions to the total acoustics of a place. These acoustic
conditions, termed acoustic habitat, are one attribute of an animal's
total habitat.
Soundscapes are also defined by, and acoustic habitat influenced
by, the total contribution of anthropogenic sound. This may include
incidental emissions from sources such as vessel traffic, may be
intentionally introduced to the marine environment for data acquisition
purposes (as in the use of airgun arrays), or for Navy training and
testing purposes (as in the use of sonar and explosives and other
acoustic sources). Anthropogenic noise varies widely in its frequency,
content, duration, and loudness and these characteristics greatly
influence the potential habitat-

[[Page 11019]]

mediated effects to marine mammals (please also see the previous
discussion on ``Masking''), which may range from local effects for
brief periods of time to chronic effects over large areas and for long
durations. Depending on the extent of effects to habitat, animals may
alter their communications signals (thereby potentially expending
additional energy) or miss acoustic cues (either conspecific or
adventitious). Problems arising from a failure to detect cues are more
likely to occur when noise stimuli are chronic and overlap with
biologically relevant cues used for communication, orientation, and
predator/prey detection (Francis and Barber, 2013). For more detail on
these concepts see, e.g., Barber et al., 2009; Pijanowski et al., 2011;
Francis and Barber, 2013; Lillis et al., 2014.
The term ``listening area'' refers to the region of ocean over
which sources of sound can be detected by an animal at the center of
the space. Loss of communication space concerns the area over which a
specific animal signal, used to communicate with conspecifics in
biologically-important contexts (e.g., foraging, mating), can be heard,
in noisier relative to quieter conditions (Clark et al., 2009). Lost
listening area concerns the more generalized contraction of the range
over which animals would be able to detect a variety of signals of
biological importance, including eavesdropping on predators and prey
(Barber et al., 2009). Such metrics do not, in and of themselves,
document fitness consequences for the marine animals that live in
chronically noisy environments. Long-term population-level consequences
mediated through changes in the ultimate survival and reproductive
success of individuals are difficult to study, and particularly so
underwater. However, it is increasingly well documented that aquatic
species rely on qualities of natural acoustic habitats, with
researchers quantifying reduced detection of important ecological cues
(e.g., Francis and Barber, 2013; Slabbekoorn et al., 2010) as well as
survivorship consequences in several species (e.g., Simpson et al.,
2014; Nedelec et al., 2015).
Sound produced from training and testing activities in the AFTT
Study Area is temporary and transitory. The sounds produced during
training and testing activities can be widely dispersed or concentrated
in small areas for varying periods. Any anthropogenic noise attributed
to training and testing activities in the AFTT Study Area would be
temporary and the affected area would be expected to immediately return
to the original state when these activities cease.
Water Quality
The AFTT DEIS/OEIS analyzed the potential effects on water quality
from military expended materials. Training and testing activities may
introduce water quality constituents into the water column. Based on
the analysis of the AFTT DEIS/OEIS, military expended materials (e.g.,
undetonated explosive materials) would be released in quantities and at
rates that would not result in a violation of any water quality
standard or criteria. High-order explosions consume most of the
explosive material, creating typical combustion products. For example,
in the case of Royal Demolition Explosive, 98 percent of the products
are common seawater constituents and the remainder is rapidly diluted
below threshold effect level. Explosion by-products associated with
high order detonations present no secondary stressors to marine mammals
through sediment or water. However, low order detonations and
unexploded ordnance present elevated likelihood of impacts on marine
mammals.
Indirect effects of explosives and unexploded ordnance to marine
mammals via sediment is possible in the immediate vicinity of the
ordnance. Degradation products of Royal Demolition Explosive are not
toxic to marine organisms at realistic exposure levels (Rosen & Lotufo,
2010). Relatively low solubility of most explosives and their
degradation products means that concentrations of these contaminants in
the marine environment are relatively low and readily diluted.
Furthermore, while explosives and their degradation products were
detectable in marine sediment approximately 6-12 in (0.15-0.3 m) away
from degrading ordnance, the concentrations of these compounds were not
statistically distinguishable from background beyond 3-6 ft (1-2 m)
from the degrading ordnance. Taken together, it is possible that marine
mammals could be exposed to degrading explosives, but it would be
within a very small radius of the explosive (1-6 ft (0.3-2 m)).
Equipment used by the Navy within the AFTT Study Area, including
ships and other marine vessels, aircraft, and other equipment, are also
potential sources of by-products. All equipment is properly maintained
in accordance with applicable Navy or legal requirements. All such
operating equipment meets Federal water quality standards, where
applicable.
Important Marine Mammal Habitat
The only ESA-listed marine mammal with designated critical habitat
within the AFTT Study Area is the NARW. This critical habitat was
discussed in the Description of Marine Mammals section. BIAs were also
discussed in the Description of Marine Mammals section.

Estimated Take of Marine Mammals

This section indicates the number of takes that NMFS is proposing
to authorize which are based on the amount of take that NMFS
anticipates could, or are likely to occur depending on the type of take
and the methods used to estimate it, as described in detail below. NMFS
coordinated closely with the Navy in the development of their
incidental take application, and with one exception, preliminarily
agrees that the methods the Navy has put forth described herein to
estimate take (including the model, thresholds, and density estimates),
and the resulting numbers proposed for authorization, are appropriate
and based on the best available science. Where we did not concur with
the Navy's analysis and proposed take numbers (i.e., large whale
mortality from ship strike), NMFS has explicitly described our
rationale and proposed what we consider an appropriate number of takes.
Takes are predominantly in the form of harassment, but a small
number of mortalities are also proposed. For this military readiness
activity, the MMPA defines ``harassment'' as: (i) Any act that injures
or has the significant potential to injure a marine mammal or marine
mammal stock in the wild (Level A Harassment); or (ii) Any act that
disturbs or is likely to disturb a marine mammal or marine mammal stock
in the wild by causing disruption of natural behavioral patterns,
including, but not limited to, migration, surfacing, nursing, breeding,
feeding, or sheltering, to a point where such behavioral patterns are
abandoned or significantly altered (Level B Harassment).
Authorized takes would primarily be by Level B harassment, as use
of the acoustic and explosive sources (i.e., sonar, airguns,
piledriving, explosives) is likely to result in behavioral disruption
or TTS for marine mammals. There is also the potential for Level A
harassment, in the form of auditory injury and/or tissue damage (latter
for explosives only) to result from exposure to the sound sources
utilized in training and testing activities. Lastly, a limited number
of serious injuries or mortalities could occur for four species of mid-
frequency cetaceans during ship shock trials and three serious injuries
or

[[Page 11020]]

mortalities total (over the 5-yr period) of mysticetes and sperm whales
through vessel collisions. Although we analyze the impacts of these
potential serious injuries or mortalities that are proposed for
authorization, the proposed mitigation and monitoring measures are
expected to minimize the likelihood that ship strike or these high
level explosive exposures (and the associated serious injury or
mortality) occur.
Described in the most basic way, we estimate the amount and type of
harassment by considering: (1) Acoustic thresholds above which NMFS
believes the best available science indicates marine mammals will be
behaviorally harassed or incur some degree of permanent hearing
impairment; (2) the area or volume of water that will be ensonified
above these levels in a day; (3) the density or occurrence of marine
mammals within these ensonified areas; and, (4) and the number of days
of activities. Below, we describe these components in more detail and
present the proposed take estimate.

Acoustic Thresholds

Using the best available science NMFS, in coordination with the
Navy, has established acoustic thresholds that identify the received
level of underwater sound above which exposed marine mammals would
reasonably expected to be experience a disruption in behavior, or to
incur TTS (equated to Level B harassment) or PTS of some degree
(equated to Level A harassment). Thresholds have also been developed to
identify the pressure levels above which animals may incur different
types of tissue damage from exposure to pressure waves from explosive
detonation.
Hearing Impairment (TTS/PTS and Tissues Damage and Mortality)

Non-Impulsive and Impulsive

NMFS' Technical Guidance for Assessing the Effects of Anthropogenic
Sound on Marine Mammal Hearing (Technical Guidance, 2016) identifies
dual criteria to assess auditory injury (Level A harassment) to five
different marine mammal groups (based on hearing sensitivity) as a
result of exposure to noise from two different types of sources
(impulsive or non-impulsive). The Technical Guidance also identifies
criteria to predict TTS, which is not considered injury and falls into
the Level B Harassment category. The Navy's proposed activity includes
the use of non-impulsive (sonar, vibratory pile driving) and impulsive
(explosives, airguns, impact pile driving) and sources.
These thresholds (Tables 13-14) were developed by compiling and
synthesizing the best available science and soliciting input multiple
times from both the public and peer reviewers to inform the final
product, and are provided in the table below. The references, analysis,
and methodology used in the development of the thresholds are described
in NMFS 2016 Technical Guidance, which may be accessed at: http://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.

Table 13--Acoustic Thresholds Identifying the Onset of TTS and PTS for
Non-Impulsive Sound Sources by Functional Hearing Group
------------------------------------------------------------------------
Non-impulsive
-------------------------------
Functional hearing group PTS Threshold
TTS Threshold SEL
SEL (weighted) (unweighted)
------------------------------------------------------------------------
Low-Frequency Cetaceans................. 179 199
Mid-Frequency Cetaceans................. 178 198
High-Frequency Cetaceans................ 153 173
Phocid Pinnipeds (Underwater)........... 181 201
------------------------------------------------------------------------
Note: SEL thresholds in dB re 1 [mu]Pa\2\s.

Based on the best available science, the Navy (in coordination with
NMFS) used the acoustic and pressure thresholds indicated in Table 14
to predict the onset of TTS, PTS, tissue damage, and mortality for
explosives (impulsive) and other impulsive sound sources.

Table 14--Onset of TTS, PTS, Tissue Damage, and Mortality Thresholds for Marine Mammals for Explosives and Other Impulsive Sources
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mean onset
Functional hearing group Species Weighted onset TTS Weighted onset PTS Mean onset slight slight lung Mean onset
GI tract injury injury mortality
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-frequency cetaceans......... All mysticetes..... 168 dB SEL or 213 183 dB SEL or 219 237 dB SPL Equation 1...... Equation 2.
dB Peak SPL. dB Peak SPL. (unweighted).
Mid-frequency cetaceans......... Most delphinids, 170 dB SEL or 224 185 dB SEL or 230 237 dB SPL
medium and large dB Peak SPL. dB Peak SPL. (unweighted).
toothed whales.
High-frequency cetaceans........ Porpoises and Kogia 140 dB SEL or 196 155 dB SEL or 202 237 dB SPL
spp. dB Peak SPL. dB Peak SPL. (unweighted).
Phocidae........................ Harbor, Gray, 170 dB SEL or 212 185 dB SEL or 218 237 dB SPL
Bearded, Harp, dB Peak SPL. dB Peak SPL. (unweighted).
Hooded, and Ringed
seals.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
Equation 1: 47.5M\1/3\ (1 + [DRm/10.1])\1/6\ Pa-sec.
Equation 2: 103M\1/3\ (1 + [DRm/10.1])\1/6\ Pa-sec.
M = mass of the animals in kg.
DRm = depth of the receiver (animal) in meters.
SPL = sound pressure level.

[[Page 11021]]

Impulsive--Airguns and Impact Pile Driving

Impact pile driving produces impulsive noise; therefore, the
criteria used to assess the onset of TTS and PTS are identical to those
used for airguns, as well as explosives (see Table 14 above) (see
Hearing Loss from Airguns in Section 6.4.3.1, Methods for Analyzing
Impacts from Airguns in the Navy's rulemaking and LOA application).
Refer to the Criteria and Thresholds for U.S. Navy Acoustic and
Explosive Impacts to Marine Mammals and Sea Turtles technical report
(U.S. Department of the Navy, 2017d) for detailed information on how
the criteria and thresholds were derived.

Non-Impulsive--Sonar and Vibratory Pile Driving/Removal

Vibratory pile removal (that will be used during the Elevated
Causeway System) creates continuous non-impulsive noise at low source
levels for a short duration. Therefore, the criteria used to assess the
onset of TTS and PTS due to exposure to sonars (non-impulsive, see
Table 13 above) are also used to assess auditory impacts to marine
mammals from vibratory pile driving (see Hearing Loss from Sonar and
Other Transducers in Section 6.4.2.1, Methods for Analyzing Impacts
from Sonars and Other Transducers in the Navy's rulemaking and LOA
application). Refer to the Criteria and Thresholds for U.S. Navy
Acoustic and Explosive Impacts to Marine Mammals and Sea Turtles
technical report (U.S. Department of the Navy, 2017d) for detailed
information on how the criteria and thresholds were derived. Non-
auditory injury (i.e., other than PTS) and mortality from sonar and
other transducers is so unlikely as to be discountable under normal
conditions and is therefore not considered further in this analysis.
Behavioral Harassment
Marine mammal responses (some of which are considered disturbances
that rise to the level of a take) 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 other prior experience
of the individuals), which means that there is support for alternative
approaches for estimating behavioral harassment. Although the statutory
definition of Level B harassment for military readiness activities
requires that the natural behavior patterns of a marine mammal be
significantly altered or abandoned, the current state of science for
determining those thresholds is somewhat unsettled. In its analysis of
impacts associated with sonar acoustic sources (which was coordinated
with NMFS), the Navy proposes an updated conservative approach that
likely overestimates the number of takes by Level B harassment due to
behavioral disturbance and response to some degree. Many of the
behavioral responses estimated using the Navy's quantitative analysis
are most likely to be moderate severity (see Southall et al., 2007 for
behavioral response severity scale). Moderate severity responses would
be considered significant if they were sustained for a duration long
enough that it caused an animal to be outside of normal daily
variations in feeding, reproduction, resting, migration/movement, or
social cohesion. Within the Navy's quantitative analysis, many
behavioral reactions are predicted from exposure to sound that may
exceed an animal's behavioral threshold for only a single exposure to
several minutes and it is likely that some of the resulting estimated
behavioral harassment takes would not constitute ``significantly
altering or abandoning natural behavioral patterns''. The Navy and NMFS
have used the best available science to address the challenging
differentiation between significant and non-significant behavioral
reactions, but have erred on the cautious side where uncertainty exists
(e.g., counting these lower duration reactions as take), which likely
results in some degree of overestimation of behavioral harassment take.
Therefore this analysis includes the maximum number of behavioral
disturbances and responses that are reasonably possible to occur.

Airguns and Pile Driving

Though significantly driven by received level, the onset of
behavioral disturbance from anthropogenic noise exposure is also
informed to varying degrees by other factors related to the source
(e.g., frequency, predictability, duty cycle), the environment (e.g.,
bathymetry), and the receiving animals (hearing, motivation,
experience, demography, behavioral context) and can be difficult to
predict (Southall et al., 2007, Ellison et al., 2011). Based on what
the available science indicates and the practical need to use a
threshold based on a factor that is both predictable and measurable for
most activities, NMFS uses a generalized acoustic threshold based on
received level to estimate the onset of behavioral harassment. NMFS
predicts that marine mammals are likely to be behaviorally harassed in
a manner we consider Level B harassment when exposed to underwater
anthropogenic noise above received levels of 120 dB re 1 [mu]Pa (rms)
for continuous (e.g., vibratory pile-driving, drilling) and above 160
dB re 1 [mu]Pa (rms) for non-explosive impulsive (e.g., seismic
airguns) or intermittent (e.g., scientific sonar) sources. To estimate
behavioral effects from airguns, the existing NMFS Level B harassment
threshold of 160 dB re 1 [micro]Pa (rms) is used. The root mean square
calculation for airguns is based on the duration defined by 90 percent
of the cumulative energy in the impulse.
The existing NMFS Level B harassment thresholds were also applied
to estimate behavioral effects from impact and vibratory pile driving
(Table 15).

Table 15--Pile Driving Level B Thresholds Used in This Analysis To
Predict Behavioral Responses From Marine Mammals
------------------------------------------------------------------------
Pile driving criteria (SPL, dB re 1 [mu]Pa) Level B disturbance
threshold
-------------------------------------------------------------------------
Underwater vibratory Underwater impact
------------------------------------------------------------------------
120 dB rms................................ 160 dB rms.
------------------------------------------------------------------------
Notes: Root mean square calculation for impact pile driving is based on
the duration defined by 90 percent of the cumulative energy in the
impulse. Root mean square for vibratory pile driving is calculated
based on a representative time series long enough to capture the
variation in levels, usually on the order of a few seconds.
dB: decibel; dB re 1 [micro]Pa: decibel referenced to 1 micropascal;
rms: root mean square.

Sonar

As noted, the Navy coordinated with NMFS to propose behavioral
harassment thresholds specific to their military readiness activities
utilizing active sonar. The way the criteria were derived is discussed
in detail in the Criteria and Thresholds for U.S. Navy Acoustic and
Explosive Impacts to Marine Mammals and Sea Turtles Technical Report
(U.S. Department of the Navy, 2017d).
In the Navy acoustic impact analyses during Phase II, the
likelihood of behavioral effects to sonar and other transducers was
based on a probabilistic function (termed a behavioral response
function--BRF), that related the likelihood (i.e., probability) of a
behavioral response to the received SPL. The BRF was used to estimate
the percentage of an exposed population that is likely to exhibit
altered behaviors or behavioral disturbance at a given received SPL.
This BRF relied on the assumption that sound poses a negligible risk to
marine mammals if they are exposed to SPL below a certain

[[Page 11022]]

``basement'' value. Above the basement exposure SPL, the probability of
a response increased with increasing SPL. Two BRFs were used in Navy
acoustic impact analyses: BRF1 for mysticetes and BRF2 for other
species. BRFs were not used for harbor porpoises and beaked whales
during Phase II analyses. Instead, step functions at SPLs of 120 dB re
1 [mu]Pa and 140 dB re 1 [mu]Pa were used for harbor porpoises and
beaked whales, respectively, as thresholds to predict behavioral
disturbance.
Developing the new behavioral criteria for Phase III involved
multiple steps: All available behavioral response studies conducted
both in the field and on captive animals were examined in order to
understand the breadth of behavioral responses of marine mammals to
sonar and other transducers. Marine mammal species were placed into
behavioral criteria groups based on their known or suspected behavioral
sensitivities to sound. In most cases these divisions were driven by
taxonomic classifications (e.g., mysticetes, pinnipeds). The data from
the behavioral studies were analyzed by looking for significant
responses, or lack thereof, for each experimental session. The Navy
used cutoffs distances beyond which the potential of significant
behavioral responses (and therefore Level B harassment) is considered
to be unlikely (see Table 16 below). For animals within the cutoff
distance, a behavioral response function based on a received SPL as
presented in Section 3.1.0 of the Navy's rulemaking and LOA application
was used to predict the probability of a potential significant
behavioral response. For training and testing events that contain
multiple platforms or tactical sonar sources that exceed 215 dB re 1
[mu]Pa @ 1 m, this cutoff distance is substantially increased (i.e.,
doubled) from values derived from the literature. The use of multiple
platforms and intense sound sources are factors that probably increase
responsiveness in marine mammals overall. There are currently few
behavioral observations under these circumstances; therefore, the Navy
conservatively predicted significant behavioral responses at further
ranges for these more intense activities.

Table 16--Cutoff Distances for Moderate Source Level, Single Platform
Training and Testing Events and for All Other Events With Multiple
Platforms or Sonar With Source Levels at or Exceeding 215 dB re 1
[micro]Pa @1 m
------------------------------------------------------------------------
Moderate SL/
single High SL/multi-
Criteria group platform platform
cutoff cutoff
distance (km) distance (km)
------------------------------------------------------------------------
Odontocetes............................. 10 20
Pinnipeds............................... 5 10
Mysticetes and Manatees................. 10 20
Beaked Whales........................... 25 50
Harbor Porpoise......................... 20 40
------------------------------------------------------------------------
Notes: dB re 1 [micro]Pa @1 m: decibels referenced to 1 micropascal at 1
meter; km: kilometer; SL: source level.

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) 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,
approximately 120 dB re 1 [micro]Pa. Therefore, a SPL of 120 dB re 1
[micro]Pa was used in the analysis as a threshold for predicting
behavioral responses in harbor porpoises.
The range to received sound levels in 6-dB steps from five
representative sonar bins and the percentage of animals that may
exhibit a potentially significant behavioral response under each
behavioral response function (or step function in the case of the
harbor porpoise) are shown in Table 17 through Table 21. Cells are
shaded if the mean range value for the specified received level exceeds
the distance cutoff range for a particular hearing group and therefore
are not included in the estimated take. Table 17 illustrates the
potentially significant behavioral response for LFAS.
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Table 21 illustrates the potentially significant behavioral
response for HFAS.

[[Page 11027]]

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Explosives

Phase III explosive criteria for behavioral thresholds for marine
mammals is the hearing groups TTS threshold minus 5 dB (see Table 22
and Table 14 for the TTS thresholds for explosives) for events that
contain multiple impulses from explosives underwater. This was the same
approach as taken in Phase II for explosive analysis.

Table 22--Phase III Behavioral Thresholds for Explosives for Marine
Mammals
------------------------------------------------------------------------
Functional hearing SEL
Medium group (weighted)
------------------------------------------------------------------------
Underwater.......................... LF 163
Underwater.......................... MF 165
Underwater.......................... HF 135
Underwater.......................... PW 165
------------------------------------------------------------------------
Note: Weighted SEL thresholds in dB re 1 [mu]Pa2s underwater.

Navy's Acoustic Effects Model

Sonar and Other Transducers and Explosives
The Navy's Acoustic Effects Model calculates sound energy
propagation from sonar and other transducers and explosives during
naval activities and the sound received by animat dosimeters. Animat
dosimeters are virtual representations of marine mammals distributed in
the area around the modeled naval activity that each records its
individual sound ``dose.'' The model bases the distribution of animats
over the AFTT Study Area on the density values in the Navy Marine
Species Density Database and distributes animats in the water column
proportional to the known time that species spend at varying depths.
The model accounts for environmental variability of sound
propagation in both distance and depth when computing the received
sound level on the animats. The model conducts a statistical analysis
based on multiple model runs to compute the estimated effects on
animals. The number of animats that exceed the thresholds for effects
is tallied to provide an estimate of the number of marine mammals that
could be affected.
Assumptions in the Navy model intentionally err on the side of
overestimation when there are unknowns. Naval activities are modeled as
though they would occur regardless of proximity to marine mammals,
meaning that no mitigation is considered (i.e., no power down or shut
down modeled) and without any avoidance of the activity by the animal.
The final step of the quantitative analysis of acoustic effects is to
consider the implementation of mitigation and the possibility that
marine mammals would avoid continued or repeated sound exposures.
The model estimates the impacts caused by individual training and
testing exercises. During any individual modeled event, impacts to
individual animats are considered over 24-hour periods. The animats do
not represent actual animals, but rather they represent a distribution
of animals based on density and abundance data, which allows for a
statistical analysis of the number of instances that marine mammals may
be exposed to sound levels resulting in an effect. Therefore, the model
estimates the number of instances in which an effect threshold was
exceeded over the course of a year, but does not estimate the number of
individual marine mammals that may be impacted over a year (i.e., some
marine mammals could be impacted several times, while others would not

[[Page 11028]]

experience any impact). A detailed explanation of the Navy's Acoustic
Effects Model is provided in the technical report Quantitative Analysis
for Estimating Acoustic and Explosive Impacts to Marine Mammals and Sea
Turtles (U.S. Department of the Navy, 2017a).
Airguns and Pile Driving
The Navy's quantitative analysis estimates the sound and energy
received by marine mammals distributed in the area around planned Navy
activities involving airguns. See the technical report titled
Quantitative Analysis for Estimating Acoustic and Explosive Impacts to
Marine Mammals and Sea Turtles (U.S. Department of the Navy, 2017a) for
additional details. Underwater noise effects from pile driving and
vibratory pile extraction were modeled using actual measures of impact
pile driving and vibratory removal during construction of an Elevated
Causeway System (Illingworth and Rodkin, 2015, 2016). A conservative
estimate of spreading loss of sound in shallow coastal waters (i.e.,
transmission loss = 16.5*Log10 [radius]) was applied based on spreading
loss observed in actual measurements. Inputs used in the model are
provided in Section 1.4.1.3 (Pile Driving) of the Navy's rulemaking and
LOA application, including source levels; the number of strikes
required to drive a pile and the duration of vibratory removal per
pile; the number of piles driven or removed per day; and the number of
days of pile driving and removal.

Range to Effects

The following section provides range to effects for sonar and other
active acoustic sources as well as explosives to specific criteria
determined using the Navy Acoustic Effects Model. Marine mammals
exposed within these ranges for the shown duration are predicted to
experience the associated effect. Range to effects is important
information in not only predicting acoustic impacts, but also in
verifying the accuracy of model results against real-world situations
and determining adequate mitigation ranges to avoid higher level
effects, especially physiological effects to marine mammals.
Sonar
The range to received sound levels in 6-dB steps from five
representative sonar bins and the percentage of the total number of
animals that may exhibit a significant behavioral response (and
therefore Level B harassment) under each behavioral response function
(or step function in the case of the harbor porpoise) are shown in
Table 17 through Table 21 above, respectively. See Section 6.4.2.1
(Methods for Analyzing Impacts from Sonars and Other Transducers) of
the Navy's rulemaking and LOA application for additional details on the
derivation and use of the behavioral response functions, thresholds,
and the cutoff distances.
The ranges to the PTS for five representative sonar systems for an
exposure of 30 seconds is shown in Table 23 relative to the marine
mammal's functional hearing group. This period (30 seconds) was chosen
based on examining the maximum amount of time a marine mammal would
realistically be exposed to levels that could cause the onset of PTS
based on platform (e.g., ship) speed and a nominal animal swim speed of
approximately 1.5 meters per second. The ranges provided in the table
include the average range to PTS, as well as the range from the minimum
to the maximum distance at which PTS is possible for each hearing
group.

Table 23--Range to Permanent Threshold Shift for Five Representative Sonar Systems
----------------------------------------------------------------------------------------------------------------
Approximate PTS (30 seconds) ranges (meters) \1\
-------------------------------------------------------------------------------
Sonar bin LF5
Functional hearing group (low frequency Sonar bin MF1 Sonar bin MF4 Sonar bin MF5 Sonar bin HF4
sources <180 (e.g., SQS-53 (e.g., AQS-22 (e.g., SSQ-62 (e.g., SQS-20
dB source ASW hull ASW dipping ASW sonobuoy) mine hunting
level) mounted sonar) sonar) sonar)
----------------------------------------------------------------------------------------------------------------
Low-frequency Cetaceans......... 0 (0-0) 66 (65-80) 15 (15-18) 0 (0-0) 0 (0-0)
Mid-frequency Cetaceans......... 0 (0-0) 16 (16-16) 3 (3-3) 0 (0-0) 1 (0-2)
High-frequency Cetaceans........ 0 (0-0) 192 (170-270) 31 (30-40) 9 (8-13) 34 (20-85)
Phocid Seals.................... 0 (0-0) 46 (45-55) 11 (11-13) 0 (0-0) 0 (0-0)
----------------------------------------------------------------------------------------------------------------
\1\ PTS ranges extend from the sonar or other active acoustic sound source to the indicated distance. The
average range to PTS is provided as well as the range from the estimated minimum to the maximum range to PTS
in parenthesis.
Notes: ASW: anti-submarine warfare; HF: High frequency; LF: Low frequency; MF: Mid-frequency; PTS: Permanent
threshold shift; NA: Not applicable because there is no overlap between species and sound source.

The tables below illustrate the range to TTS for 1, 30, 60, and 120
seconds from five representative sonar systems (see Table 24 through
Table 28).

Table 24--Ranges to Temporary Threshold Shift for Sonar Bin LF5 Over a Representative Range of Environments
Within the Study Area
----------------------------------------------------------------------------------------------------------------
Approximate TTS ranges (meters) \1\
---------------------------------------------------------------
Functional hearing group Sonar bin LF5 (low frequency sources <180 dB source level)
---------------------------------------------------------------
1 second 30 seconds 60 seconds 120 seconds
--------------------------------------------------------------------------------------------------
Low-frequency Cetaceans........... 4 (0-5) 4 (0-5) 4 (0-5) 4 (0-5)
Mid-frequency Cetaceans........... 222 (200-310) 222 (200-310) 331 (280-525) 424 (340-800)
High-frequency Cetaceans.......... 0 (0-0) 0 (0-0) 0 (0-0) 0 (0-0)

[[Page 11029]]

Phocid Seals...................... 0 (0-0) 0 (0-0) 0 (0-0) 0 (0-0)
----------------------------------------------------------------------------------------------------------------
\1\ Ranges to TTS represent the model predictions in different areas and seasons within the Study Area. The
zone in which animals are expected to suffer TTS extend from onset-PTS to the distance indicated. The average
range to TTS is provided as well as the range from the estimated minimum to the maximum range to TTS in
parenthesis.
Notes: Ranges for 1-sec and 30-sec periods are identical for Bin MF1 because this system nominally pings every
50 seconds, therefore these periods encompass only a single ping. PTS: Permanent threshold shift; TTS:
Temporary threshold shift.

Table 25--Ranges to Temporary Threshold Shift for Sonar Bin MF1 Over a Representative Range of Environments Within the Study Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
Approximate TTS ranges (meters) \1\
-----------------------------------------------------------------------------------
Functional hearing group Sonar bin MF1 (e.g., SQS-53 ASW hull mounted sonar)
-----------------------------------------------------------------------------------
1 second 30 seconds 60 seconds 120 seconds
-------------------------------------------------------------------------------------------------------------------------------------
Low-frequency Cetaceans.......................... 1,111 (650-2,775) 1,111 (650-2,775) 1,655 (800-3,775) 2,160 (900-6,525)
Mid-frequency Cetaceans.......................... 222 (200-310) 222 (200-310) 331 (280-525) 424 (340-800)
High-frequency Cetaceans......................... 3,001 (1275-8,275) 3,001 (1275-8,275) 4,803 (1525-13,525) 6,016 (1525-16,775)
Phocid Seals..................................... 784 (575-1,275) 784 (575-1,275) 1,211 (850-3,025) 1,505 (1025-3,775)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Ranges to TTS represent the model predictions in different areas and seasons within the Study Area. The zone in which animals are expected to
suffer TTS extend from onset-PTS to the distance indicated. The average range to TTS is provided as well as the range from the estimated minimum to
the maximum range to TTS in parenthesis.
Notes: Ranges for 1-sec and 30-sec periods are identical for Bin MF1 because this system nominally pings every 50 seconds, therefore these periods
encompass only a single ping. ASW: Anti-submarine warfare; MF: Mid-frequency; PTS: Permanent threshold shift; TTS: Temporary threshold shift.

Table 26--Ranges to Temporary Threshold Shift for Sonar Bin MF4 Over a Representative Range of Environments
Within the Study Area
----------------------------------------------------------------------------------------------------------------
Approximate TTS ranges (meters) \1\
-----------------------------------------------------------------------------------
Functional hearing group Sonar bin MF4 (e.g., AQS-22 ASW dipping sonar)
-----------------------------------------------------------------------------------
1 second 30 seconds 60 seconds 120 seconds
----------------------------------------------------------------------------------------------------------------
Low-frequency Cetaceans..... 89 (85-120) 175 (160-280) 262 (220-575) 429 (330-875)
Mid-frequency Cetaceans..... 22 (22-25) 36 (35-45) 51 (45-60) 72 (70-95)
High-frequency Cetaceans.... 270 (220-575) 546 (410-1,025) 729 (525-1,525) 1,107 (600-2,275)
Phocid Seals................ 67 (65-90) 119 (110-180) 171 (150-260) 296 (240-700)
----------------------------------------------------------------------------------------------------------------
\1\ Ranges to TTS represent the model predictions in different areas and seasons within the Study Area. The zone
in which animals are expected to suffer TTS extend from onset-PTS to the distance indicated. The average range
to TTS is provided as well as the range from the estimated minimum to the maximum range to TTS in parenthesis.
Notes: ASW: Anti-submarine warfare; MF: Mid-frequency; PTS: Permanent threshold shift; TTS: Temporary threshold
shift.

Table 27--Ranges to Temporary Threshold Shift for Sonar Bin MF5 Over a Representative Range of Environments
Within the Study Area
----------------------------------------------------------------------------------------------------------------
Approximate TTS ranges (meters) \1\
-----------------------------------------------------------------------------------
Functional hearing group Sonar bin MF5 (e.g., SSQ-62 ASW sonobuoy)
-----------------------------------------------------------------------------------
1 second 30 seconds 60 seconds 120 seconds
----------------------------------------------------------------------------------------------------------------
Low-frequency Cetaceans..... 11 (0-14) 11 (0-14) 16 (0-20) 23 (0-25)
Mid-frequency Cetaceans..... 5 (0-10) 5 (0-10) 12 (0-15) 17 (0-22)
High-frequency Cetaceans.... 122 (110-320) 122 (110-320) 187 (150-525) 286 (210-750)

[[Page 11030]]

Phocid Seals................ 9 (8-13) 9 (8-13) 15 (14-18) 22 (21-25)
----------------------------------------------------------------------------------------------------------------
\1\ Ranges to TTS represent the model predictions in different areas and seasons within the Study Area. The zone
in which animals are expected to suffer TTS extend from onset-PTS to the distance indicated. The average range
to TTS is provided as well as the range from the estimated minimum to the maximum range to TTS in parenthesis.
Notes: ASW: Anti-submarine warfare; MF: Mid-frequency; PTS: Permanent threshold shift; TTS: Temporary threshold
shift.

Table 28--Ranges to Temporary Threshold Shift for Sonar Bin HF4 Over a Representative Range of Environments
Within the Study Area
----------------------------------------------------------------------------------------------------------------
Approximate TTS ranges (meters) \1\
-----------------------------------------------------------------------------------
Functional hearing group Sonar bin HF4 (e.g., SQS-20 mine hunting sonar)
-----------------------------------------------------------------------------------
1 second 30 seconds 60 seconds 120 seconds
----------------------------------------------------------------------------------------------------------------
Low-frequency Cetaceans..... 1 (0-3) 3 (0-5) 5 (0-7) 7 (0-12)
Mid-frequency Cetaceans..... 10 (7-17) 19 (11-35) 27 (17-60) 39 (22-100)
High-frequency Cetaceans.... 242 (100-975) 395 (170-1,775) 524 (230-2,775) 655 (300-4,275)
Phocid Seals................ 2 (0-5) 5 (0-8) 8 (5-13) 12 (8-20)
----------------------------------------------------------------------------------------------------------------
\1\ Ranges to TTS represent the model predictions in different areas and seasons within the Study Area. The zone
in which animals are expected to suffer TTS extend from onset-PTS to the distance indicated. The average range
to TTS is provided as well as the range from the estimated minimum to the maximum range to TTS in parenthesis.
Notes: HF: High frequency; PTS: Permanent threshold shift; TTS: Temporary threshold shift.

Explosives
The following section provides the range (distance) over which
specific physiological or behavioral effects are expected to occur
based on the explosive criteria (see Chapter 6.5.2.1.1 of the Navy's
rulemaking and LOA application and Criteria and Thresholds Used to
Estimate Impacts to Marine Mammals from Explosives) and the explosive
propagation calculations from the Navy Acoustic Effects Model (see
Chapter 6.5.2.1.3, Navy Acoustic Effects Model of the Navy's rulemaking
and LOA application). The range to effects are shown for a range of
explosive bins, from E1 (up to 0.25 lb net explosive weight) to E17 (up
to 58,000 lb net explosive weight) (Tables 29 through 34). Ranges are
determined by modeling the distance that noise from an explosion will
need to propagate to reach exposure level thresholds specific to a
hearing group that will cause behavioral response, TTS, PTS, and non-
auditory injury. Ranges are provided for a representative source depth
and cluster size for each bin. For events with multiple explosions,
sound from successive explosions can be expected to accumulate and
increase the range to the onset of an impact based on SEL thresholds.
Ranges to non-injury and mortality are shown in Table 33 and 34,
respectively. Range to effects is important information in not only
predicting impacts from explosives, but also in verifying the accuracy
of model results against real-world situations and determining adequate
mitigation ranges to avoid higher level effects, especially
physiological effects to marine mammals. For additional information on
how ranges to impacts from explosions were estimated, see the technical
report Quantifying Acoustic Impacts on Marine Mammals and Sea Turtles:
Methods and Analytical Approach for Phase III Training and Testing
(U.S. Navy, 2017b).
Table 29. shows the minimum, average, and maximum ranges to onset
of auditory and behavioral effects for high-frequency cetaceans based
on the developed thresholds.

Table 29--SEL-Based Ranges to Onset PTS, Onset TTS, and Behavioral Reaction for High-Frequency Cetaceans
--------------------------------------------------------------------------------------------------------------------------------------------------------
Range to effects for explosives: high frequency cetaceans \1\
---------------------------------------------------------------------------------------------------------------------------------------------------------
Source depth
Bin (m) Cluster size PTS TTS Behavioral
--------------------------------------------------------------------------------------------------------------------------------------------------------
E1........................................ 0.1 1 446 (180-975) 1,512 (525-3,775) 2,591 (800-6,775)
20 1,289 (440-3,025) 4,527 (1,275-10,775) 6,650 (1,525-16,525)
E2........................................ 0.1 1 503 (200-1,025) 1,865 (600-3,775) 3,559 (1,025-6,775)
2 623 (250-1,275) 2,606 (750-5,275) 4,743 (1,275-8,525)
E3........................................ 18.25 1 865 (525-2,525) 3,707 (1,025-6,775) 5,879 (1,775-10,025)
50 4,484 (1,275-7,775) 10,610 (2,275-19,775) 13,817 (2,275-27,025)
E4........................................ 15 1 1,576 (1,025-2,275) 6,588 (4,525-8,775) 9,744 (7,275-13,025)

[[Page 11031]]

5 3,314 (2,275-4,525) 10,312 (7,525-14,775) 14,200 (9,775-20,025)
19.8 2 1,262 (975-2,025) 4,708 (1,775-7,525) 6,618 (2,025-11,525)
198 2 1,355 (875-2,775) 4,900 (2,525-8,275) 6,686 (3,025-11,275)
E5........................................ 0.1 25 3,342 (925-8,025) 8,880 (1,275-20,525) 11,832 (1,525-25,025)
E6........................................ 0.1 1 1,204 (550-3,275) 4,507 (1,275-10,775) 6,755 (1,525-16,525)
30 1 2,442 (1,525-5,025) 7,631 (4,525-10,775) 10,503 (4,775-15,025)
E7........................................ 15 1 3,317 (2,525-4,525) 10,122 (7,775-13,275) 13,872 (9,775-17,775)
E8........................................ 0.1 1 1,883 (675-4,525) 6,404 (1,525-14,525) 9,001 (1,525-19,775)
45.75 1 2,442 (1,025-5,525) 7,079 (2,025-12,275) 9,462 (2,275-17,025)
305 1 3,008 (2,025-4,025) 9,008 (6,025-10,775) 12,032 (8,525-14,525)
E9........................................ 0.1 1 2,210 (800-4,775) 6,088 (1,525-13,275) 8,299 (1,525-19,025)
E10....................................... 0.1 1 2,960 (875-7,275) 8,424 (1,525-19,275) 11,380 (1,525-24,275)
E11....................................... 18.5 1 4,827 (1,525-8,775) 11,231 (2,525-20,025) 14,667 (2,525-26,775)
45.75 1 3,893 (1,525-7,525) 9,320 (2,275-17,025) 12,118 (2,525-21,525)
E12....................................... 0.1 1 3,046 (1,275-6,775) 7,722 (1,525-18,775) 10,218 (2,025-22,525)
E16....................................... 61 1 5,190 (2,275-9,775) 7,851 (3,525-19,525) 9,643 (3,775-25,775)
E17....................................... 61 1 6,173 (2,525-12,025) 11,071 (3,775-29,275) 13,574 (4,025-37,775)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Distances in meters (m). Average distance is shown with the minimum and maximum distances due to varying propagation environments in parentheses.

Table 30 shows the minimum, average, and maximum ranges to onset of
auditory and behavioral effects for mid-frequency cetaceans based on
the developed thresholds.

Table 30--SEL-Based Ranges to Onset PTS, Onset TTS, and Behavioral Reaction for Mid-Frequency Cetaceans
--------------------------------------------------------------------------------------------------------------------------------------------------------
Range to effects for explosives: mid-frequency cetaceans \1\
---------------------------------------------------------------------------------------------------------------------------------------------------------
Source depth
Bin (m) Cluster size PTS TTS Behavioral
--------------------------------------------------------------------------------------------------------------------------------------------------------
E1........................................ 0.1 1 26 (25-50) 139 (95-370) 218 (120-550)
20 113 (80-290) 539 (210-1,025) 754 (270-1,525)
E2........................................ 0.1 1 35 (30-45) 184 (100-300) 276 (130-490)
2 51 (40-70) 251 (120-430) 365 (160-700)
E3........................................ 18.25 1 40 (35-45) 236 (190-800) 388 (280-1,275)
50 304 (230-1,025) 1,615 (750-3,275) 2,424 (925-5,025)
E4........................................ 15 1 74 (60-100) 522 (440-750) 813 (650-1,025)
5 192 (140-260) 1,055 (875-1,525) 1,631 (1,275-2,525)
19.8 2 69 (65-70) 380 (330-470) 665 (550-750)
198 2 48 (0-55) 307 (260-380) 504 (430-700)
E5........................................ 0.1 25 391 (170-850) 1,292 (470-3,275) 1,820 (575-5,025)
E6........................................ 0.1 1 116 (90-290) 536 (310-1,025) 742 (380-1,525)
30 1 110 (85-310) 862 (600-2,275) 1,281 (975-3,275)
E7........................................ 15 1 201 (190-220) 1,067 (1,025-1,275) 1,601 (1,275-2,025)
E8........................................ 0.1 1 204 (150-500) 802 (400-1,525) 1,064 (470-2,275)
45.75 1 133 (120-200) 828 (525-2,025) 1,273 (775-2,775)
305 1 58 (0-110) 656 (550-750) 1,019 (900-1,025)
E9........................................ 0.1 1 241 (200-370) 946 (450-1,525) 1,279 (500-2,275)
E10....................................... 0.1 1 339 (230-750) 1,125 (490-2,525) 1,558 (550-4,775)
E11....................................... 18.5 1 361 (230-750) 1,744 (800-3,775) 2,597 (925-5,025)
45.75 1 289 (230-825) 1,544 (800-3,275) 2,298 (925-5,025)
E12....................................... 0.1 1 382 (270-550) 1,312 (525-2,775) 1,767 (600-4,275)
E16....................................... 61 1 885 (650-1,775) 3,056 (1,275-5,025) 3,689 (1,525-6,525)
E17....................................... 61 1 1,398 (925-2,275) 3,738 (1,525-6,775) 4,835 (1,775-9,275)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\Distances in meters (m). Average distance is shown with the minimum and maximum distances due to varying propagation environments in parentheses.

Table 31 shows the minimum, average, and maximum ranges to onset of
auditory and behavioral effects for low-frequency cetaceans based on
the developed thresholds.

[[Page 11032]]

Table 31--SEL-Based Ranges to Onset PTS, Onset TTS, and Behavioral Reaction for Low-Frequency Cetaceans
--------------------------------------------------------------------------------------------------------------------------------------------------------
Range to effects for explosives: low-frequency cetaceans \1\
---------------------------------------------------------------------------------------------------------------------------------------------------------
Source depth
Bin (m) Cluster size PTS TTS Behavioral
--------------------------------------------------------------------------------------------------------------------------------------------------------
E1........................................ 0.1 1 54 (45-80) 259 (130-390) 137 (90-210)
20 211 (110-320) 787 (340-1,525) 487 (210-775)
E2........................................ 0.1 1 64 (55-75) 264 (150-400) 154 (100-220)
2 87 (70-110) 339 (190-500) 203 (120-300)
E3........................................ 18.25 1 211 (190-390) 1,182 (600-2,525) 588 (410-1,275)
50 1,450 (675-3,275) 8,920 (1,525-24,275) 4,671 (1,025-10,775)
E4........................................ 15 1 424 (380-550) 3,308 (2,275-4,775) 1,426 (1,025-2,275)
5 1,091 (950-1,525) 6,261 (3,775-9,525) 3,661 (2,525-5,275)
19.8 2 375 (350-400) 1,770 (1,275-3,025) 1,003 (725-1,275)
198 2 308 (280-380) 2,275 (1,275-3,525) 1,092 (850-2,275)
E5........................................ 0.1 25 701 (300-1,525) 4,827 (750-29,275) 1,962 (575-22,525)
E6........................................ 0.1 1 280 (150-450) 1,018 (460-7,275) 601 (300-1,525)
30 1 824 (525-1,275) 4,431 (2,025-7,775) 2,334 (1,275-4,275)
E7........................................ 15 1 1,928 (1,775-2,275) 8,803 (6,025-14,275) 4,942 (3,525-6,525)
E8........................................ 0.1 1 486 (220-1,000) 3,059 (575-20,525) 1,087 (440-7,775)
45.75 1 1,233 (675-3,025) 7,447 (1,275-19,025) 3,633 (1,000-9,025)
305 1 937 (875-975) 6,540 (3,025-12,025) 3,888 (2,025-6,525)
E9........................................ 0.1 1 655 (310-1,275) 2,900 (650-31,025) 1,364 (500-8,525)
E10....................................... 0.1 1 786 (340-7,275) 7,546 (725-49,025) 3,289 (550-26,525)
E11....................................... 18.5 1 3,705 (925-8,775) 16,488 (2,275-40,275) 9,489 (1,775-22,775)
45.75 1 3,133 (925-8,275) 16,365 (1,775-50,275) 8,701 (1,275-23,775)
E12....................................... 0.1 1 985 (400-6,025) 7,096 (800-72,775) 2,658 (625-46,525)
E16....................................... 61 1 10,155 (2,025-21,525) 35,790 (18,025-69,775) 25,946 (14,025-58,775)
E17....................................... 61 1 17,464 (8,275-39,525) 47,402 (21,025-93,275) 34,095 (16,275-86,275)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Distances in meters (m). Average distance is shown with the minimum and maximum distances due to varying propagation environments in parentheses.

Table 32. shows the minimum, average, and maximum ranges to onset
of auditory and behavioral effects for phocids based on the developed
thresholds.

Table 32--SEL-Based Ranges to Onset PTS, Onset TTS, and Behavioral Reaction for Phocids
--------------------------------------------------------------------------------------------------------------------------------------------------------
Range to effects for explosives: phocids \1\
---------------------------------------------------------------------------------------------------------------------------------------------------------
Source depth
Bin (m) Cluster size PTS TTS Behavioral
--------------------------------------------------------------------------------------------------------------------------------------------------------
E1........................................ 0.1 1 50 (45-85) 242 (120-470) 360 (160-650)
20 197 (110-380) 792 (300-1,275) 1,066 (410-2,275)
E2........................................ 0.1 1 65 (55-85) 267 (140-430) 378 (190-675)
2 85 (65-100) 345 (180-575) 476 (230-875)
E3........................................ 18.25 1 121 (110-220) 689 (500-1,525) 1,074 (725-2,525)
50 859 (600-2,025) 4,880 (1,525-10,525) 7,064 (1,775-16,275)
E4........................................ 15 1 213 (190-260) 1,246 (1,025-1,775) 2,006 (1,525-3,025)
5 505 (450-600) 2,933 (2,275-4,275) 4,529 (3,275-6,775)
19.8 2 214 (210-220) 1,083 (900-2,025) 1,559 (1,025-2,525)
198 2 156 (150-180) 1,141 (825-2,275) 2,076 (1,275-3,525)
E5........................................ 0.1 25 615 (250-1,025) 2,209 (850-9,775) 3,488 (1,025-15,275)
E6........................................ 0.1 1 210 (160-380) 796 (480-1,275) 1,040 (600-3,275)
30 1 359 (280-625) 1,821 (1,275-2,775) 2,786 (1,775-4,275)
E7........................................ 15 1 557 (525-650) 3,435 (2,775-4,525) 5,095 (3,775-6,775)
E8........................................ 0.1 1 346 (230-600) 1,136 (625-4,025) 1,708 (850-6,025)
45.75 1 469 (380-1,025) 2,555 (1,275-6,025) 3,804 (1,525-9,775)
305 1 322 (310-330) 3,222 (1,775-4,525) 4,186 (2,275-5,775)
E9........................................ 0.1 1 441 (330-575) 1,466 (825-5,775) 2,142 (950-9,775)
E10....................................... 0.1 1 539 (350-900) 1,914 (875-8,525) 3,137 (1,025-15,025)
E11....................................... 18.5 1 1,026 (700-2,025) 5,796 (1,525-12,775) 8,525 (1,775-19,775)
45.75 1 993 (675-2,275) 4,835 (1,525-13,525) 7,337 (1,775-18,775)
E12....................................... 0.1 1 651 (420-900) 2,249 (950-11,025) 3,349 (1,275-16,025)
E16....................................... 61 1 2,935 (1,775-5,025) 6,451 (2,275-16,275) 10,619 (3,275-24,025)
E17....................................... 61 1 3,583 (1,775-7,525) 12,031 (3,275-29,275) 18,396 (7,275-41,025)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Distances in meters (m). Average distance is shown with the minimum and maximum distances due to varying propagation environments in parentheses.

[[Page 11033]]

Table 33 below shows the average and ranges due to varying
propagation conditions to non-auditory injury as a function of
explosive bin (i.e., net explosive weight). Ranges to gastrointestinal
tract injury typically exceed ranges to slight lung injury; therefore,
the maximum range to effect is not mass-dependent. Animals within these
water volumes would be expected to receive minor injuries at the outer
ranges, increasing to more substantial injuries, and finally mortality
as an animal approaches the detonation point.

Table 33--Ranges \1\ to 50% Non-Auditory Injury Risk for All Marine
Mammal Hearing Groups
------------------------------------------------------------------------
Bin Range (m)
------------------------------------------------------------------------
E1............................................. 22 (22-35)
E2............................................. 25 (25-30)
E3............................................. 46 (35-75)
E4............................................. 63 (0-130)
E5............................................. 75 (55-130)
E6............................................. 97 (65-390)
E7............................................. 232 (200-270)
E8............................................. 170 (0-490)
E9............................................. 215 (100-430)
E10............................................ 251 (110-700)
E11............................................ 604 (400-2,525)
E12............................................ 436 (130-1,025)
E16............................................ 1,844 (925-3,025)
E17............................................ 3,649 (1,000-14,025)
------------------------------------------------------------------------
\1\ Distances in meters (m). Average distance is shown with the minimum
and maximum distances due to varying propagation environments in
parentheses. Modeled ranges based on peak pressure for a single
explosion generally exceed the modeled ranges based on impulse
(related to animal mass and depth).

Ranges to mortality, based on animal mass, are shown in Table 34
below.

Table 34--Ranges \1\ to 50% Mortality Risk for All Marine Mammal Hearing Groups as a Function of Animal Mass
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Representative animal mass (kg)
Bin -----------------------------------------------------------------------------------------------------------------------------
10 250 1,000 5,000 25,000 72,000
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
E1................................................................ 4 (3-5) 1 (0-3) 0 (0-0) 0 (0-0) 0 (0-0) 0 (0-0)
E2................................................................ 5 (5-7) 3 (0-5) 0 (0-2) 0 (0-0) 0 (0-0) 0 (0-0)
E3................................................................ 11 (9-15) 6 (3-11) 3 (2-4) 0 (0-2) 0 (0-0) 0 (0-0)
E4................................................................ 20 (0-45) 11 (0-30) 5 (0-13) 3 (0-6) 1 (0-2) 0 (0-2)
E5................................................................ 18 (14-50) 10 (5-35) 5 (3-11) 3 (2-6) 0 (0-3) 0 (0-2)
E6................................................................ 26 (17-75) 14 (0-55) 7 (0-20) 4 (3-10) 2 (0-4) 1 (0-3)
E7................................................................ 100 (75-130) 49 (25-95) 21 (17-30) 13 (11-15) 7 (6-7) 5 (4-6)
E8................................................................ 69 (0-140) 36 (0-100) 16 (0-30) 12 (0-17) 6 (0-8) 5 (0-7)
E9................................................................ 58 (40-200) 26 (17-55) 14 (11-18) 9 (8-11) 5 (4-5) 4 (3-5)
E10............................................................... 107 (40-320) 39 (19-220) 18 (14-35) 12 (10-21) 6 (6-9) 5 (4-6)
E11............................................................... 299 (230-675) 163 (90-490) 74 (55-150) 45 (35-85) 24 (21-40) 19 (15-30)
E12............................................................... 194 (60-460) 82 (25-340) 22 (18-30) 15 (12-17) 8 (7-9) 6 (5-7)
E16............................................................... 1,083 (925-1,525) 782 (500-1,025) 423 (350-550) 275 (230-300) 144 (130-150) 105 (90-120)
E17............................................................... 1,731 (925-2,525) 1,222 (700-2,275) 857 (575-1,025) 586 (470-825) 318 (290-340) 244 (210-280)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Distances in meters (m). Average distance is shown with the minimum and maximum distances due to varying propagation environments in parentheses.

Airguns
Table 35 and Table 36 present the approximate ranges in meters to
PTS, TTS, and potential behavioral reactions for airguns for 10 and 100
pulses, respectively. Ranges are specific to the AFTT Study Area and
also to each marine mammal hearing group, dependent upon their criteria
and the specific locations where animals from the hearing groups and
the airgun activities could overlap. Small air guns (12-60 in.\3\)
would be fired pierside at the Naval Undersea Warfare Center Division,
Newport Testing Range, and at off-shore locations typically in the
Northeast, Virginia Capes, and Gulf of Mexico Range Complexes. Single,
small air guns lack the peak pressures that could cause non-auditory
injury (see Finneran et al., (2015)).

Table 35--Range to Effects From Airguns for 10 Pulses
--------------------------------------------------------------------------------------------------------------------------------------------------------
Range to effects for airguns \1\ for 10 pulses (m)
---------------------------------------------------------------------------------------------------------------------------------------------------------
PTS (Peak TTS (Peak
Hearing group PTS (SEL) SPL) TTS (SEL) SPL) Behavioral \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
High-Frequency Cetacean............................................ 0 (0-0) 15 (15-15) 0 (0-0) 25 (25-25) 700 (250-1,025)
Low-Frequency Cetacean............................................. 13 (12-13) 2 (2-2) 72 (70-80) 4 (4-4) 685 (170-1,025)
Mid-Frequency Cetacean............................................. 0 (0-0) 0 (0-0) 0 (0-0) 0 (0-0) 680 (160-2,275)
Phocids............................................................ 0 (0-0) 2 (2-2) 3 (3-3) 4 (4-4) 708 (220-1,025)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Average distance (m) to PTS, TTS, and behavioral thresholds are depicted above the minimum and maximum distances which are in parentheses. PTS and
TTS values depict the range produced by SEL and Peak SPL (as noted) hearing threshold criteria levels.
\2\ Behavioral values depict the ranges produced by RMS hearing threshold criteria levels.

[[Page 11034]]

Table 36--Range to Effects From Airguns for 100 Pulses
--------------------------------------------------------------------------------------------------------------------------------------------------------
Range to effects for airguns \1\ for 100 pulses (m)
---------------------------------------------------------------------------------------------------------------------------------------------------------
PTS (Peak TTS (Peak
Hearing group PTS (SEL) SPL) TTS (SEL) SPL) Behavioral \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
High-Frequency Cetacean............................................ 4 (4-4) 40 (40-40) 48 (45-50) 66 (65-70) 2,546 (1,025-5,525)
Low-Frequency Cetacean............................................. 122 (120-130) 3 (3-3) 871 (600-1,275) 13 (12-13) 2,546 (1,025-5,525)
Mid-Frequency Cetacean............................................. 0 (0-0) 0 (0-0) 0 (0-0) 0 (0-0) 2,546 (1,025-5,525)
Phocids............................................................ 3 (2-3) 3 (3-3) 25 (25-25) 14 (14-15) 2,546 (1,025-5,525)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Average distance (m) to PTS, TTS, and behavioral thresholds are depicted above the minimum and maximum distances which are in parentheses. PTS and
TTS values depict the range produced by SEL and Peak SPL (as noted) hearing threshold criteria levels.
\2\ Behavioral values depict the ranges produced by RMS hearing threshold criteria levels.

Pile Driving
Table 37 and Table 38 present the approximate ranges in meters to
PTS, TTS, and potential behavioral reactions for impact pile driving
and vibratory pile removal, respectively. Non-auditory injury is not
predicted for pile driving activities.

Table 37--Average Ranges to Effects From Impact Pile Driving
----------------------------------------------------------------------------------------------------------------
Hearing group PTS (m) TTS (m) Behavioral (m)
----------------------------------------------------------------------------------------------------------------
Low-frequency Cetaceans......................................... 65 529 870
Mid-frequency Cetaceans......................................... 2 16 870
High-frequency Cetaceans........................................ 65 529 870
Phocids......................................................... 19 151 870
----------------------------------------------------------------------------------------------------------------
Notes: PTS: permanent threshold shift; TTS: temporary threshold shift.

Table 38--Average Ranges to Effects From Vibratory Pile Extraction
----------------------------------------------------------------------------------------------------------------
Hearing group PTS (m) TTS (m) Behavioral (m)
----------------------------------------------------------------------------------------------------------------
Low-frequency Cetaceans......................................... 0 3 376
Mid-frequency Cetaceans......................................... 0 4 376
High-frequency Cetaceans........................................ 7 116 376
Phocids......................................................... 0 2 376
----------------------------------------------------------------------------------------------------------------
Notes: PTS: permanent threshold shift; TTS: temporary threshold shift.

Serious Injury or Mortality From Ship Strikes
There have been three recorded Navy vessel strikes of marine
mammals in the AFTT Study Area to from 2009 through 2017 (nine years).
There are incidents in which a vessel struck animal has remained
unidentified to species and the Navy cannot quantifiably predict that
the possible takes from vessel strike will be of any particular
species. Therefore, the Navy requested mortal takes of three large
whales over the course of the five-year rule, and no more than two of
any species of humpback whale, fin whale, sei whale, minke whale, blue
whale, or sperm whale (either GOM or North Atlantic). NMFS concurs that
the request for mortal takes of three large whales (of any species
listed in previous sentence) over the five-year period of the rule is
reasonable based on the available strike data and the Navy's analysis
(see their updated ship strike analysis on NMFS website https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities), but does not agree
that two mortal takes of any one species is likely. When the
probability of hitting more than one individual of the same species
within the five-year period is considered in combination with the
available data indicating the proportional historical strikes of
different species and the probability of hitting the same species
twice, the likelihood of hitting the same species of whale twice in
five years is very low (under to well under 10 percent). Therefore, we
find that it is unlikely that the same species would be struck twice
during the five-year regulatory period and are proposing to authorize
up to three mortal takes of no more than one from any of the species of
large whales over the five-year period, which means an annual average
of 0.2 whales from each species (i.e., 1 take over 5 years divided by 5
to get the annual number).

Marine Mammal Density

A quantitative analysis of impacts on a species or stock requires
data on number of animals that may be affected by anthropogenic
activities and distribution in the potentially impacted area. The most
appropriate metric for this type of analysis is density, which is the
number of animals present per unit area. Marine species density
estimation requires a significant amount of effort to both collect and
analyze data to produce a reasonable estimate. Unlike surveys for
terrestrial wildlife, many marine species spend much of their time
submerged, and are not easily observed. In order to collect enough
sighting data to make reasonable density estimates, multiple
observations are required, often in areas that are not easily
accessible (e.g., far offshore). Ideally, marine mammal species
sighting data would be collected for the specific area and time period
(e.g., season) of interest and density estimates derived accordingly.
However, in many places,

[[Page 11035]]

poor weather conditions and high sea states prohibit the completion of
comprehensive visual surveys.
For most cetacean species, abundance is estimated using line-
transect surveys or mark-recapture studies (e.g., Barlow, 2010, Barlow
and Forney, 2007, Calambokidis et al., 2008). The result provides one
single density estimate value for each species across broad geographic
areas. This is the general approach applied in estimating cetacean
abundance in the NMFS SARS. Although the single value provides a good
average estimate of abundance (total number of individuals) for a
specified area, it does not provide information on the species
distribution or concentrations within that area, and it does not
estimate density for other timeframes or seasons that were not
surveyed. More recently, habitat modeling has been used to estimate
cetacean densities (Barlow et al., 2009; Becker et al., 2010, 2012a, b,
c; Ferguson et al., 2006a; Forney et al., 2012; Redfern et al., 2006).
These models estimate cetacean density as a continuous function of
habitat variables (e.g., sea surface temperature, seafloor depth, etc.)
and thus allow predictions of cetacean densities on finer spatial
scales than traditional line-transect or mark recapture analyses.
Within the geographic area that was modeled, densities can be predicted
wherever these habitat variables can be measured or estimated.
To characterize the marine species density for large areas such as
the AFTT Study Area, the Navy compiled data from several sources. The
Navy developed a protocol to select the best available data sources
based on species, area, and time (season). The resulting Geographic
Information System database called the Navy Marine Species Density
Database includes seasonal density values for every marine mammal
species present within the AFTT Study Area. This database is described
in the technical report titled U.S. Navy Marine Species Density
Database Phase III for the Atlantic Fleet Training and Testing Area
(U.S. Department of the Navy, 2017), hereafter referred to as the
density technical report.
A variety of density data and density models are needed in order to
develop a density database that encompasses the entirety of the AFTT
Study Area. Because this data is collected using different methods with
varying amounts of accuracy and uncertainty, the Navy has developed a
model hierarchy to ensure the most accurate data is used when
available. The density technical report describes these models in
detail and provides detailed explanations of the models applied to each
species density estimate. The below list describes possible models in
order of preference.
1. Spatial density models (see Roberts et al. (2016)) predict
spatial variability of animal presence based on habitat variables
(e.g., sea surface temperature, seafloor depth, etc.). This model is
developed for areas, species, and, when available, specific timeframes
(months or seasons) with sufficient survey data; therefore, this model
cannot be used for species with low numbers of sightings. In the AFTT
Study Area, this model is available for certain species along the east
coast to the offshore extent of available survey data and in the Gulf
of Mexico.
2. Design-based density models predict animal density based on
survey data. Like spatial density models, they are applied to areas
with survey data. Design-based density models may be stratified, in
which a density is predicted for each sub-region of a survey area,
allowing for better prediction of species distribution across the
density model area. In the AFTT Study Area, stratified density models
are used for certain species on both the east coast and the Gulf of
Mexico. In addition, a few species' stratified density models are
applied to areas east of regions with available survey data and cover a
substantial portion of the Atlantic Ocean portion of the AFTT Study
Area.
3. Extrapolative models are used in areas where there is
insufficient or no survey data. These models use a limited set of
environmental variables to predict possible species densities based on
environmental observations during actual marine mammal surveys (see
Mannocci et al. (2017)). In the AFTT Study Area, extrapolative models
are typically used east of regions with available survey data and cover
a substantial portion of the Atlantic Ocean of the AFTT Study Area.
Because some unsurveyed areas have oceanographic conditions that are
very different from surveyed areas (e.g., the Labrador Sea and North
Atlantic gyre) and some species models rely on a very limited data set,
the predictions of some species' extrapolative density models and some
regions of certain species' extrapolative density models are considered
highly speculative. Extrapolative models are not used in the Gulf of
Mexico.
4. Existing Relative Environmental Suitability models include a
high degree of uncertainty, but are applied when no other model is
available.
When interpreting the results of the quantitative analysis, as
described in the density technical report (U.S. Department of the Navy,
2017), ``it is important to consider that even the best estimate of
marine species density is really a model representation of the values
of concentration where these animals might occur. Each model is limited
to the variables and assumptions considered by the original data source
provider. No mathematical model representation of any biological
population is perfect and with regards to marine species biodiversity,
any single model method will not completely explain the actual
distribution and abundance of marine mammal species. It is expected
that there would be anomalies in the results that need to be evaluated,
with independent information for each case, to support if we might
accept or reject a model or portions of the model.''

Take Requests

The AFTT DEIS/OEIS considered all training and testing activities
proposed to occur in the AFTT Study Area that have the potential to
result in the MMPA defined take of marine mammals. The Navy determined
that the three stressors below could result in the incidental taking of
marine mammals. NMFS has reviewed the Navy's data and analysis and
determined that it is complete and accurate and agrees that the
following stressors have the potential to result in takes of marine
mammals from the Proposed Activity.
[ssquf] Acoustics (sonar and other transducers; airguns; pile
driving/extraction).
[ssquf] Explosives (explosive shock wave and sound; explosive
fragments).
[ssquf] Physical Disturbance and Strike (vessel strike).
Acoustic and explosive sources have the potential to result in
incidental takes of marine mammals by harassment, serious injury, or
mortality. Vessel strikes have the potential to result in incidental
take from serious injury or mortality.
The quantitative analysis process used for the AFTT DEIS/OEIS and
the Navy's take request in the rulemaking and LOA application to
estimate potential exposures to marine mammals resulting from acoustic
and explosive stressors is detailed in the technical report titled
Quantitative Analysis for Estimating Acoustic and Explosive Impacts to
Marine Mammals and Sea Turtles (U.S. Department of the Navy, 2017a).
The Navy Acoustic Effects Model estimates acoustic and explosive
effects without taking mitigation into

[[Page 11036]]

account; therefore, the model overestimates predicted impacts on marine
mammals within mitigation zones. To account for mitigation for marine
species in the take estimates, the Navy conducts a post-modeling
analysis using applicable literature to conservatively quantify the
manner in which mitigation is expected to reduce model-estimated PTS to
TTS for exposures to sonar and other transducers, and reduce model-
estimated mortality to injury for exposures to explosives. The Navy
coordinated with NMFS in the development of this quantitative method to
address the effects of mitigation on acoustic exposures and takes, and
concurs with the Navy that it is appropriate to incorporate into the
take estimates based on the best available science. For additional
information on the quantitative analysis process and mitigation
measures, refer to Section 6 (Take Estimates for Marine Mammals) and
Section 11 (Mitigation Measures) of the Navy's rulemaking and LOA
application.
Summary of Proposed Authorized Take From Training and Testing
Activities
Based on the methods outlined in the previous sections, Navy's
model analysis, the Navy's summarizes the take request for acoustic and
explosive sources for training and testing activities annually (based
on the maximum number of activities per 12-month period), and the
summation over a five-year period, as well as the Navy's take request
for individual small and large ship shock trials, and the take that
could occur over a five-year period for all ship shock activities. NMFS
has reviewed the Navy's data and analysis and preliminary determined
that it is complete and accurate and that the takes by harassment
proposed for authorization are reasonably expected to occur and that
the takes by mortality could occur as in the case of vessel strikes.
Take Reasonably Expected To Occur From Training Activities
Table 39 summarizes the Navy's take request and the amount and type
of take that is reasonably likely to occur (Level A and Level B
harassment) by species associated with all training activities. Note
that Level B take includes both behavioral disruption and TTS. Navy
figures 6.4-10 through 6.5-69 in Section 6 of the Navy's rulemaking and
LOA application illustrate the comparative amounts of TTS and
behavioral disruption for each species, noting that if a ``taken''
animal was exposed to both TTS and behavioral disruption in the model,
it was recorded as a TTS.

Table 39--Species and Stock-Specific Take Proposed for Authorization for All Training Activities
----------------------------------------------------------------------------------------------------------------
Annual 5-Year total
Species Stock ---------------------------------------------------------------
Level B Level A Level B Level A
----------------------------------------------------------------------------------------------------------------
Suborder Mysticeti (baleen whales)
----------------------------------------------------------------------------------------------------------------
Family Balaenidae (right whales)
----------------------------------------------------------------------------------------------------------------
North Atlantic right whale *.. Western North 246 0 1,176 0
Atlantic.
----------------------------------------------------------------------------------------------------------------
Family Balaenopteridae (roquals)
----------------------------------------------------------------------------------------------------------------
Blue whale *.................. Western North 26 0 121 0
Atlantic (Gulf
of St.
Lawrence).
Bryde's whale................. Northern Gulf of 0 0 0 0
Mexico.
NSD [dagger].... 206 0 961 0
Minke whale................... Canadian East 2,425 0 11,262 0
Coast.
Fin whale *................... Western North 1,498 3 7,295 13
Atlantic.
Humpback whale................ Gulf of Maine... 232 1 1,116 3
Sei whale *................... Nova Scotia..... 292 0 1,400 0
----------------------------------------------------------------------------------------------------------------
Suborder Odontoceti (toothed whales)
----------------------------------------------------------------------------------------------------------------
Family Physeteridae (sperm whale)
----------------------------------------------------------------------------------------------------------------
Sperm whale *................. Gulf of Mexico 24 0 118 0
Oceanic.
North Atlantic.. 14,084 0 68,839 0
----------------------------------------------------------------------------------------------------------------
Family Kogiidae (sperm whales)
----------------------------------------------------------------------------------------------------------------
Dwarf sperm whale............. Gulf of Mexico 14 0 71 0
Oceanic.
Western North 8,527 10 39,914 48
Atlantic.
Pygmy sperm whale............. Northern Gulf of 14 0 71 0
Mexico.
Western North 8,527 10 39,914 48
Atlantic.
----------------------------------------------------------------------------------------------------------------
Family Ziphiidae (beaked whales)
----------------------------------------------------------------------------------------------------------------
Blainville's beaked whale..... Northern Gulf of 35 0 173 0
Mexico.
Western North 12,532 0 61,111 0
Atlantic.
Cuvier's beaked whale......... Northern Gulf of 34 0 172 0
Mexico.
Western North 46,401 0 226,286 0
Atlantic.
Gervais' beaked whale......... Northern Gulf of 35 0 173 0
Mexico.
Western North 12,532 0 61,111 0
Atlantic.
Northern bottlenose whale..... Western North 1,074 0 5,360 0
Atlantic.
Sowersby's beaked whale....... Western North 12,532 0 61,111 0
Atlantic.
True's beaked whale........... Western North 12,532 0 61,111 0
Atlantic.
----------------------------------------------------------------------------------------------------------------

[[Page 11037]]

Family Delphinidae (dolphins)
----------------------------------------------------------------------------------------------------------------
Atlantic spotted dolphin...... Northern Gulf of 951 0 4,710 0
Mexico.
Western North 117,458 9 570,940 45
Atlantic.
Atlantic white-sided dolphin.. Western North 14,493 1 71,050 3
Atlantic.
Bottlenose dolphin............ Choctawhatchee 7 0 33 0
Bay.
Gulf of Mexico 42 0 125 0
Eastern Coastal.
Gulf of Mexico 218 0 1,088 0
Northern
Coastal.
Gulf of Mexico 4,148 0 12,568 0
Western Coastal.
Indian River 283 0 1,414 0
Lagoon
Estuarine
System.
Jacksonville 84 0 421 0
Estuarine
System.
Mississippi 0 0 0 0
Sound, Lake
Borgne, Bay
Boudreau.
Northern Gulf of 1,560 2 7,798 9
Mexico
Continental
Shelf.
Northern Gulf of 194 0 969 0
Mexico Oceanic.
Northern North 3,221 0 11,798 0
Carolina
Estuarine
System.
Southern North 0 0 0 0
Carolina
Estuarine
System.
Western North 906 0 4,323 0
Atlantic
Northern
Florida Coastal.
Western North 5,341 0 25,594 0
Atlantic
Central Florida
Coastal.
Western North 25,188 4 125,183 19
Atlantic
Northern
Migratory
Coastal.
Western North 308,206 39 1,473,308 193
Atlantic
Offshore.
Western North 4,328 0 20,559 0
Atlantic South
Carolina/
Georgia Coastal.
Western North 12,493 2 58,061 10
Atlantic
Southern
Migratory
Coastal.
Clymene dolphin............... Northern Gulf of 99 0 495 0
Mexico.
Western North 69,773 3 330,027 13
Atlantic.
False killer whale............ Northern Gulf of 41 0 207 0
Mexico.
Western North 8,270 0 39,051 0
Atlantic.
Fraser's dolphin.............. Northern Gulf of 59 0 296 0
Mexico.
Western North 3,930 0 18,633 0
Atlantic.
Killer whale.................. Northern Gulf of 1 0 4 0
Mexico.
Western North 78 0 372 0
Atlantic.
Long-finned pilot whale....... Western North 17,040 0 83,050 0
Atlantic.
Melon-headed whale............ Northern Gulf of 70 0 352 0
Mexico.
Western North 37,156 1 175,369 3
Atlantic.
Pantropical spotted dolphin... Northern Gulf of 565 0 2,827 0
Mexico.
Western North 145,125 2 686,775 10
Atlantic.
Pygmy killer whale............ Northern Gulf of 16 0 82 0
Mexico.
Western North 6,482 0 30,639 0
Atlantic.
Risso's dolphin............... Northern Gulf of 39 0 197 0
Mexico.
Western North 21,033 0 100,018 0
Atlantic.
Rough-toothed dolphin......... Northern Gulf of 97 0 434 0
Mexico.
Western North 19,568 0 92,313 0
Atlantic.
Short-beaked common dolphin... Western North 218,145 12 1,046,192 61
Atlantic.
Short-finned pilot whale...... Northern Gulf of 36 0 179 0
Mexico.
Western North 31,357 0 150,213 0
Atlantic.
Spinner dolphin............... Northern Gulf of 227 0 1,136 0
Mexico.
Western North 73,691 1 347,347 6
Atlantic.
Striped dolphin............... Northern Gulf of 67 0 336 0
Mexico.
Western North 91,038 3 451,001 13
Atlantic.
White-beaked dolphin.......... Western North 39 0 192 0
Atlantic.
----------------------------------------------------------------------------------------------------------------
Family Phocoenidae (porpoises)
----------------------------------------------------------------------------------------------------------------
Harbor porpoise............... Gulf of Maine/ 29,789 161 147,289 802
Bay of Fundy.
----------------------------------------------------------------------------------------------------------------
Suborder Pinnipedia
----------------------------------------------------------------------------------------------------------------
Family Phocidae (true seals)
----------------------------------------------------------------------------------------------------------------
Gray seal..................... Western North 1,443 0 7,172 0
Atlantic.

[[Page 11038]]

Harbor seal................... Western North 2,341 0 11,631 0
Atlantic.
Harp seal..................... Western North 8,444 1 42,188 4
Atlantic.
Hooded seal................... Western North 128 0 631 0
Atlantic.
----------------------------------------------------------------------------------------------------------------
* ESA-listed species (all stocks) within the AFTT Study Area.
[dagger] NSD: No stock designated.

Take Reasonably Expected To Occur From Testing Activities
Table 40 summarizes the Navy's take request and the amount and type
of take that is reasonably likely to occur (Level A and Level B
harassment) by species associated with all testing activities.

Table 40--Species-Specific Take Proposed for Authorization From All Testing Activities (Excluding Ship Shock
Trials)
----------------------------------------------------------------------------------------------------------------
Annual 5-Year total
Species Stock ---------------------------------------------------------------
Level B Level A Level B Level A
----------------------------------------------------------------------------------------------------------------
Suborder Mysticeti (baleen whales)
----------------------------------------------------------------------------------------------------------------
Family Balaenidae (right whales)
----------------------------------------------------------------------------------------------------------------
North Atlantic right whale *.. Western North 339 0 1,667 0
Atlantic.
----------------------------------------------------------------------------------------------------------------
Family Balaenopteridae (roquals)
----------------------------------------------------------------------------------------------------------------
Blue whale *.................. Western North 20 0 97 0
Atlantic (Gulf
of St.
Lawrence).
Bryde's whale................. Northern Gulf of 52 0 254 0
Mexico.
NSD [dagger].... 124 0 612 0
Minke whale................... Canadian East 1,616 1 7,971 7
Coast.
Fin whale *................... Western North 3,868 3 18,781 16
Atlantic.
Humpback whale................ Gulf of Maine... 493 0 2,412 0
Sei whale *................... Nova Scotia..... 502 0 2,431 0
----------------------------------------------------------------------------------------------------------------
Suborder Odontoceti (toothed whales)
----------------------------------------------------------------------------------------------------------------
Family Physeteridae (sperm whale)
----------------------------------------------------------------------------------------------------------------
Sperm whale *................. Gulf of Mexico 1,106 0 5,237 0
Oceanic.
North Atlantic.. 11,296 0 51,752 0
----------------------------------------------------------------------------------------------------------------
Family Kogiidae (sperm whales)
----------------------------------------------------------------------------------------------------------------
Dwarf sperm whale............. Gulf of Mexico 728 6 3,424 27
Oceanic.
Western North 4,383 14 21,159 65
Atlantic.
Pygmy sperm whale............. Northern Gulf of 728 6 3,424 27
Mexico.
Western North 4,383 14 21,159 65
Atlantic.
----------------------------------------------------------------------------------------------------------------
Family Ziphiidae (beaked whales)
----------------------------------------------------------------------------------------------------------------
Blainville's beaked whale..... Northern Gulf of 1,392 0 6,710 0
Mexico.
Western North 10,565 0 49,646 0
Atlantic.
Cuvier's beaked whale......... Northern Gulf of 1,460 0 6,987 0
Mexico.
Western North 38,780 0 182,228 0
Atlantic.
Gervais' beaked whale......... Northern Gulf of 1,392 0 6,710 0
Mexico.
Western North 10,565 0 49,646 0
Atlantic.
Northern bottlenose whale..... Western North 971 0 4,485 0
Atlantic.
Sowersby's beaked whale....... Western North 10,593 0 49,764 0
Atlantic.
True's beaked whale........... Western North 10,593 0 49,764 0
Atlantic.
----------------------------------------------------------------------------------------------------------------
Family Delphinidae (dolphins)
----------------------------------------------------------------------------------------------------------------
Atlantic spotted dolphin...... Northern Gulf of 71,883 2 333,793 12
Mexico.
Western North 109,582 11 504,537 50
Atlantic.
Atlantic white-sided dolphin.. Western North 31,780 1 150,063 6
Atlantic.
Bottlenose dolphin............ Choctawhatchee 966 0 4,421 0
Bay.

[[Page 11039]]

Gulf of Mexico 0 0 0 0
Eastern Coastal.
Gulf of Mexico 16,258 1 76,439 5
Northern
Coastal.
Gulf of Mexico 3,677 0 18,036 0
Western Coastal.
Indian River 3 0 14 0
Lagoon
Estuarine
System.
Jacksonville 3 0 13 0
Estuarine
System.
Mississippi 1 0 3 0
Sound, Lake
Borgne, Bay
Boudreau.
Northern Gulf of 125,941 8 594,921 39
Mexico
Continental
Shelf.
Northern Gulf of 14,448 1 67,243 5
Mexico Oceanic.
Northern North 107 0 533 0
Carolina
Estuarine
System.
Southern North 0 0 0 0
Carolina
Estuarine
System.
Western North 328 0 1,613 0
Atlantic
Northern
Florida Coastal.
Western North 2,273 0 10,950 0
Atlantic
Central Florida
Coastal.
Western North 11,854 3 56,321 14
Atlantic
Northern
Migratory
Coastal.
Western North 119,880 24 566,572 115
Atlantic
Offshore.
Western North 1,632 0 8,017 0
Atlantic South
Carolina/
Georgia Coastal.
Western North 4,221 0 20,828 0
Atlantic
Southern
Migratory
Coastal.
Clymene dolphin............... Northern Gulf of 4,164 0 19,919 0
Mexico.
Western North 35,985 2 170,033 7
Atlantic.
False killer whale............ Northern Gulf of 1,931 0 9,116 0
Mexico.
Western North 3,766 0 17,716 0
Atlantic.
Fraser's dolphin.............. Northern Gulf of 1,120 0 5,314 0
Mexico.
Western North 1,293 0 6,069 0
Atlantic.
Killer whale.................. Northern Gulf of 32 0 150 0
Mexico.
Western North 42 0 188 0
Atlantic.
Long-finned pilot whale....... Western North 20,502 2 94,694 6
Atlantic.
Melon-headed whale............ Northern Gulf of 3,058 0 14,544 0
Mexico.
Western North 16,688 1 78,545 4
Atlantic.
Pantropical spotted dolphin... Northern Gulf of 25,929 1 121,468 4
Mexico.
Western North 77,450 4 355,889 17
Atlantic.
Pygmy killer whale............ Northern Gulf of 719 0 3,415 0
Mexico.
Western North 2,848 0 13,427 0
Atlantic.
Risso's dolphin............... Northern Gulf of 1,649 0 7,817 0
Mexico.
Western North 20,071 1 94,009 6
Atlantic.
Rough-toothed dolphin......... Northern Gulf of 3,927 0 18,493 0
Mexico.
Western North 8,766 0 41,492 0
Atlantic.
Short-beaked common dolphin... Western North 353,012 16 1,675,885 71
Atlantic.
Short-finned pilot whale...... Northern Gulf of 1,823 0 8,613 0
Mexico.
Western North 17,002 1 80,576 6
Atlantic.
Spinner dolphin............... Northern Gulf of 7,815 0 36,567 0
Mexico.
Western North 33,350 2 157,241 7
Atlantic.
Striped dolphin............... Northern Gulf of 2,447 0 11,700 0
Mexico.
Western North 102,047 5 465,392 21
Atlantic.
White-beaked dolphin.......... Western North 44 0 213 0
Atlantic.
----------------------------------------------------------------------------------------------------------------
Family Phocoenidae (porpoises)
----------------------------------------------------------------------------------------------------------------
Harbor porpoise............... Gulf of Maine/ 135,221 230 627,215 1,093
Bay of Fundy.
----------------------------------------------------------------------------------------------------------------
Suborder Pinnipedia
----------------------------------------------------------------------------------------------------------------
Family Phocidae (true seals)
----------------------------------------------------------------------------------------------------------------
Gray seal..................... Western North 899 2 4,375 9
Atlantic.
Harbor seal................... Western North 1,496 5 7,095 16
Atlantic.
Harp seal..................... Western North 7,791 0 38,273 11
Atlantic.
Hooded seal................... Western North 782 0 3,805 0
Atlantic.
----------------------------------------------------------------------------------------------------------------
* ESA-listed species (all stocks) within the AFTT Study Area.
[dagger] NSD: No stock designated.

[[Page 11040]]

Take Reasonably Expected To Occur From Ship Shock
Table 41 summarizes the Navy's take request and the maximum amount
and type of take that could potentially occur (Level B and Level A
harassment, or serious injury/mortality) by species for ship shock
trials under testing activities per small and large ship shock events
and the summation over a five-year period. The table below displays
maximum ship shock impacts to marine mammals by species (in bold text),
as well as maximum impacts on individual stocks. The maximum is derived
by selecting the highest number of potential impacts across all
locations and all seasons for each species/stock. Small Ship Shock
trials could take place any season within the deep offshore water of
the Virginia Capes Range Complex or in the spring, summer, or fall
within the Jacksonville Range Complex and could occur up to three times
over a five-year period. The Large Ship Shock trial could take place in
the Jacksonville Range Complex during the Spring, Summer, or Fall and
during any season within the deep offshore water of the Virginia Capes
Range Complex or within the Gulf of Mexico. The Large Ship Shock Trial
could occur once over 5 years. For serious injury/mortality takes over
the five-year period, an annual average of 0.2 whales from each dolphin
species/stock listed below (i.e., 1 take divided by 5 years to get the
annual number) or 1.2 dolphins in the case of short-beaked common
dolphin (i.e., 6 takes divided by 5 years to get the annual number) is
used in further analysis in the ``Negligible Impact Analysis and
Determination'' section.

Table 41--Species Specific Take Proposed for Authorization From Ship Shock Trials
--------------------------------------------------------------------------------------------------------------------------------------------------------
Small ship shock Large ship shock 5-Year total
Species/stock --------------------------------------------------------------------------------------------------
Level B Level A Mortality Level B Level A Mortality Level B Level A Mortality
--------------------------------------------------------------------------------------------------------------------------------------------------------
Suborder Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenidae (right whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Atlantic right whale........................... 1 0 0 2 0 0 5 0 0
Western North Atlantic *............................. 1 0 0 2 0 0 5 0 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenopteridae (roquals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale........................................... 0 0 0 1 0 0 1 0 0
Western North Atlantic (Gulf of St. Lawrence) *...... 0 0 0 1 0 0 1 0 0
Bryde's whale........................................ 3 0 0 6 1 0 15 1 0
Northern Gulf of Mexico *............................ 0 0 0 3 1 0 3 1 0
NSD [dagger]......................................... 3 0 0 6 0 0 15 0 0
Minke whale.......................................... 19 1 0 39 3 0 96 6 0
Canadian East Coast.................................. 19 1 0 39 3 0 96 6 0
Fin whale............................................ 131 3 0 234 27 0 627 36 0
Western North Atlantic *............................. 131 3 0 234 27 0 627 36 0
Humpback whale....................................... 8 0 0 20 2 0 44 2 0
Gulf of Maine........................................ 8 0 0 20 2 0 44 2 0
Sei whale............................................ 12 1 0 27 4 0 63 7 0
Nova Scotia *........................................ 12 1 0 27 4 0 63 7 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
Suborder Odontoceti (toothed whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Physeteridae (sperm whale)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale *........................................ 1 1 0 3 4 0 6 7 0
Gulf of Mexico Oceanic............................... 0 0 0 2 0 0 2 0 0
North Atlantic....................................... 1 1 0 3 4 0 6 7 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Kogiidae (sperm whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dwarf sperm whale.................................... 46 28 0 91 70 0 229 154 0
Gulf of Mexico Oceanic............................... 0 0 0 51 64 0 51 64 0
Western North Atlantic............................... 46 28 0 91 70 0 229 154 0
Pygmy sperm whale.................................... 46 28 0 91 70 0 229 154 0
Northern Gulf of Mexico.............................. 0 0 0 51 64 0 51 64 0
Western North Atlantic............................... 46 28 0 91 70 0 229 154 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Ziphiidae (beaked whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blainville's beaked whale............................ 1 0 0 1 1 0 4 1 0
Northern Gulf of Mexico.............................. 0 0 0 1 0 0 1 0 0
Western North Atlantic............................... 1 0 0 1 1 0 4 1 0
Cuvier's beaked whale................................ 2 1 0 2 3 0 4 1 0
Northern Gulf of Mexico.............................. 0 0 0 1 0 0 1 0 0
Western North Atlantic............................... 2 1 0 2 3 0 8 6 0
Gervais' beaked whale................................ 1 0 0 1 1 0 8 6 0
Northern Gulf of Mexico.............................. 0 0 0 1 0 0 1 0 0
Western North Atlantic............................... 1 0 0 1 1 0 4 1 0
Northern bottlenose whale............................ 0 0 0 0 0 0 0 0 0
Western North Atlantic............................... 0 0 0 0 0 0 0 0 0
Sowerby's beaked whale............................... 1 0 0 1 1 0 4 1 0
Western North Atlantic............................... 1 0 0 1 1 0 4 1 0
True's beaked whale.................................. 1 0 0 1 1 0 4 1 0
Western North Atlantic............................... 1 0 0 1 1 0 4 1 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae (dolphins)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Atlantic spotted dolphin............................. 6 4 0 8 12 0 26 24 0

[[Page 11041]]

Northern Gulf of Mexico.............................. 0 0 0 2 1 0 2 1 0
Western North Atlantic............................... 6 4 0 8 12 0 26 24 0
Atlantic white-sided dolphin......................... 1 1 0 3 9 1 6 12 1
Western North Atlantic............................... 1 1 0 3 9 1 6 12 1
Bottlenose dolphin................................... 13 10 0 16 24 0 55 54 0
Choctawhatchee Bay................................... 0 0 0 0 0 0 0 0 0
Gulf of Mexico Eastern Coastal....................... 0 0 0 0 0 0 0 0 0
Gulf of Mexico Northern Coastal...................... 0 0 0 1 1 0 1 1 0
Gulf of Mexico Western Coastal....................... 0 0 0 0 0 0 0 0 0
Indian River Lagoon Estuarine System................. 0 0 0 0 0 0 0 0 0
Jacksonville Estuarine System........................ 0 0 0 0 0 0 0 0 0
Mississippi Sound, Lake Borgne, Bay Boudreau......... 0 0 0 0 0 0 0 0 0
Northern Gulf of Mexico Continental Shelf............ 0 0 0 10 6 0 10 6 0
Northern Gulf of Mexico Oceanic...................... 0 0 0 10 9 0 10 9 0
Northern North Carolina Estuarine System............. 0 0 0 0 0 0 0 0 0
Southern North Carolina Estuarine System............. 0 0 0 0 0 0 0 0 0
Western North Atlantic Northern Florida Coastal...... 0 0 0 0 0 0 0 0 0
Western North Atlantic Central Florida Coastal....... 0 0 0 0 0 0 0 0 0
Western North Atlantic Northern Migratory Coastal.... 0 0 0 0 0 0 0 0 0
Western North Atlantic Offshore...................... 13 10 0 16 24 0 55 54 0
Western North Atlantic South Carolina/Georgia Coastal 0 0 0 0 0 0 0 0 0
Western North Atlantic Southern Migratory Coastal.... 0 0 0 0 0 0 0 0 0
Clymene dolphin...................................... 2 5 0 9 8 0 15 23 0
Northern Gulf of Mexico.............................. 0 0 0 8 6 0 8 6 0
Western North Atlantic............................... 2 5 0 9 8 0 15 23 0
False killer whale................................... 0 0 0 2 1 0 2 1 0
Northern Gulf of Mexico.............................. 0 0 0 2 1 0 2 1 0
Western North Atlantic............................... 0 0 0 2 0 0 2 0 0
Fraser's dolphin..................................... 0 0 0 2 3 0 2 3 0
Northern Gulf of Mexico.............................. 0 0 0 2 3 0 2 3 0
Western North Atlantic............................... 0 0 0 0 0 0 0 0 0
Killer whale......................................... 0 0 0 0 0 0 0 0 0
Northern Gulf of Mexico.............................. 0 0 0 0 0 0 0 0 0
Western North Atlantic............................... 0 0 0 0 0 0 0 0 0
Long-finned pilot whale.............................. 2 2 0 5 6 0 11 12 0
Western North Atlantic............................... 2 2 0 5 6 0 11 12 0
Melon-headed whale................................... 1 1 0 5 4 0 8 7 0
Northern Gulf of Mexico.............................. 0 0 0 4 4 0 4 4 0
Western North Atlantic............................... 1 1 0 5 1 0 8 4 0
Pantropical spotted dolphin.......................... 2 3 0 25 20 1 31 29 1
Northern Gulf of Mexico.............................. 0 0 0 25 20 1 25 20 1
Western North Atlantic............................... 2 3 0 7 3 0 13 12 0
Pygmy killer whale................................... 0 0 0 1 1 0 1 1 0
Northern Gulf of Mexico.............................. 0 0 0 1 1 0 1 1 0
Western North Atlantic............................... 0 0 0 1 0 0 1 0 0
Risso's dolphin...................................... 1 1 0 3 1 0 6 4 0
Northern Gulf of Mexico.............................. 0 0 0 2 1 0 2 1 0
Western North Atlantic............................... 1 1 0 3 1 0 6 4 0
Rough-toothed dolphin................................ 1 0 0 3 2 0 6 2 0
Northern Gulf of Mexico.............................. 0 0 0 2 2 0 2 2 0
Western North Atlantic............................... 0 0 0 0 0 0 0 0 0
Short-beaked common dolphin.......................... 40 51 1 67 107 3 187 260 6
Western North Atlantic............................... 40 51 1 67 107 3 187 260 6
Short-finned pilot whale............................. 2 2 0 4 5 0 10 11 0
Northern Gulf of Mexico.............................. 0 0 0 2 3 0 2 3 0
Western North Atlantic............................... 2 2 0 4 5 0 10 11 0
Spinner dolphin...................................... 3 1 0 37 45 1 46 48 1
Northern Gulf of Mexico.............................. 0 0 0 37 45 1 37 45 1
Western North Atlantic............................... 3 1 0 7 3 0 16 6 0
Striped dolphin...................................... 4 8 0 10 12 0 22 36 0
Northern Gulf of Mexico.............................. 0 0 0 4 3 0 4 3 0
Western North Atlantic............................... 4 8 0 10 12 0 22 36 0
White-beaked dolphin................................. 0 0 0 0 0 0 0 0 0
Western North Atlantic............................... 0 0 0 0 0 0 0 0 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocoenidae (porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor porpoise...................................... 43 41 0 120 81 0 249 204 0
Gulf of Maine/Bay of Fundy........................... 43 41 0 120 81 0 249 204 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
Suborder Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (true seals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray seal............................................ 0 0 0 0 0 0 0 0 0
Western North Atlantic............................... 0 0 0 0 0 0 0 0 0
Harbor seal.......................................... 0 0 0 0 0 0 0 0 0
Western North Atlantic............................... 0 0 0 0 0 0 0 0 0
Harp seal............................................ 0 0 0 0 0 0 0 0 0

[[Page 11042]]

Western North Atlantic............................... 0 0 0 0 0 0 0 0 0
Hooded seal.......................................... 0 0 0 0 0 0 0 0 0
Western North Atlantic............................... 0 0 0 0 0 0 0 0 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: The table displays maximum ship shock impacts to marine mammals by species (in bold text), as well as maximum impacts on individual stocks.
* ESA-listed species' stocks within the AFTT Study Area.
[dagger] NSD: No stock designated.

Take From Vessel Strikes
Vessel strike to marine mammals is not associated with any specific
training or testing activity but is rather an extremely limited and
sporadic, but possible, accidental result of Navy vessel movement
within the AFTT Study Area or while in transit. There have been three
recorded Navy vessel strikes of large whales (i.e., mysticetes and
sperm whales) in the AFTT Study Area to from 2009 through 2017 (nine
years). In order to account for the accidental nature of vessel strikes
to large whales in general, and the potential risk from any vessel
movement within the AFTT Study Area, the Navy requests incidental takes
based on the resulting probabilities presented in their analysis as
described in detail in Chapter 6 of the Navy's rulemaking and LOA
application (and further refine ship strike analysis on NMFS website
https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities and
coordination with NMFS), as well as the cumulative low history of Navy
vessel strikes since 2009 and introduction of the Marine Species
Awareness Training and adoption of additional mitigation measures. Most
Navy-reported whale strikes have not been identified to the species
level, however, small delphinids are neither expected nor authorized to
be struck by Navy vessels since: They have not been struck historically
by Navy AFTT activities, their smaller size and maneuverability makes a
strike from a larger vessel much less likely as illustrated in
worldwide ship-strike records, and the majority of the Navy's faster-
moving activities are located in offshore areas where smaller delphinid
densities are less. Accordingly, NMFS proposes takes of large whales
only over the course of the five-year regulations from training and
testing activities as discussed below.
The Navy estimated that it may strike, and take by serious injury
or mortality, up to three large whales incidental to the Proposed
Activity over the course of the five years of the AFTT regulations.
Because of the number of incidents in which the struck animal has
remained unidentified to species, the Navy cannot quantifiably predict
that the potential takes will be of any particular species, and
therefore requested incidental take authorization for up to two of any
the following species in the five-year period: Humpback whale (Gulf of
Maine stock), fin whale (Western North Atlantic stock), minke (Canadian
East Coast stock), and sperm whale (North Atlantic stock) and one of
any of the following: Sei whale (Nova Scotia stock), blue whale
(Western North Atlantic stock), sperm whale (Gulf of Mexico Oceanic
stock).
NMFS agrees that the request for mortal takes of three large whales
(of any species listed in previous bullet) over the five-year period of
the rule is reasonable based on the available strike data (three
strikes by Navy over nine years) and the Navy's analysis, but does not
agree that two mortal takes of any one species is likely. When the
probability of hitting more than one individual of the same species
within the five-year period is considered in combination with the
available data indicating the proportional historical strikes of
different species and the probability of hitting the same species
twice, the likelihood of hitting the same species of whale twice in
five years is very low (under to well under 10 percent). Therefore, we
find that it is unlikely that the same species would be struck twice
during the five-year regulatory period and are proposing to authorize
up to three mortal takes of no more than one from any of the species of
large whales over the five-year period, which means an annual average
of 0.2 whales from each species/stock listed above (i.e., 1 take
divided by 5 years to get the annual number).
In addition to procedural mitigation, the Navy will implement
measures in mitigation areas used by NARW for foraging, calving, and
migration (see Section 11, Mitigation Measures of the Navy's rulemaking
and LOA application and a full analysis of Mitigation in Chapter 5 of
the AFTT DEIS/OEIS). These measures, which go above and beyond those
focused on other species (e.g., funding of and communication with
sightings systems, implementation of speed reductions during applicable
circumstances in certain areas) have helped the Navy avoid striking a
NARW during training and testing activities in the past; and therefore,
are likely to eliminate the potential for future strikes to occur. In
particular, the mitigation pertaining to vessels, including the
continued participation in and sponsoring of the Early Warning System,
will help Navy vessels avoid NARW during transits and training and
testing activities. The Early Warning System is a comprehensive
information exchange network dedicated to reducing the risk of vessel
strikes to NARW off the southeast United States from all mariners
(i.e., Navy and non-Navy vessels). Navy participants include the Fleet
Area Control and Surveillance Facility, Jacksonville; Commander, Naval
Submarine Forces, Norfolk, Virginia; and Naval Submarine Support
Command. The Navy, U.S. Coast Guard, U.S. Army Corps of Engineers, and
NMFS collaboratively sponsor daily aerial surveys from December 1
through March 31 (weather permitting) to observe for NARW from the
shoreline out to approximately 30-35 nmi offshore. Aerial surveyors
relay sightings information to all mariners transiting within the NARW
calving habitat (e.g., commercial vessels, recreational boaters, and
Navy ships). Refer to Section 11 (Mitigation Measures) of the Navy's
rulemaking and LOA application for a full list of these measures.
Regarding the Bryde's whale, due to low numbers, almost exclusively
limited to Gulf of Mexico, and limited ship traffic that overlaps with
Bryde's whale habitat, Navy does not anticipate any ship strike takes.

Proposed Mitigation Measures

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, and on

[[Page 11043]]

the availability of such species or stock for subsistence uses''
(``least practicable adverse impact''). NMFS does not have a regulatory
definition for least practicable adverse impact. The NDAA for FY 2004
amended the MMPA as it relates to military readiness activities and the
incidental take authorization process such that a determination of
``least practicable adverse impact'' shall include consideration of
personnel safety, practicality of implementation, and impact on the
effectiveness of the ``military readiness activity.''
In Conservation Council for Hawaii v. National Marine Fisheries
Service, 97 F. Supp.3d 1210, 1229 (D. Haw. Mar. 31, 2015), the Court
stated that NMFS ``appear[s] to think [it] satisf[ies] the statutory
`least practicable adverse impact' requirement with a `negligible
impact' finding.'' More recently, expressing similar concerns in a
challenge to our last U.S. Navy Operations of Surveillance Towed Array
Sensor System Low Frequency Active Sonar (SURTASS LFA) incidental take
rule (77 FR 50290), the Ninth Circuit Court of Appeals in Natural
Resources Defense Council (NRDC) v. Pritzker, 828 F.3d 1125, 1134 (9th
Cir. 2016), stated, ``[c]ompliance with the `negligible impact'
requirement does not mean there [is] compliance with the `least
practicable adverse impact standard [. . .] .'' As the Ninth Circuit
noted in its opinion, however, the Court was interpreting the statute
without the benefit of NMFS' formal interpretation. We state here
explicitly that NMFS is in full agreement that the ``negligible
impact'' and ``least practicable adverse impact'' requirements are
distinct, even though both statutory standards refer to species and
stocks. With that in mind, we provide further explanation of our
interpretation of least practicable adverse impact, and explain what
distinguishes it from the negligible impact standard. This discussion
is consistent with, and expands upon, previous rules we have issued
(such as the Navy Gulf of Alaska rule (82 FR 19530)).
Before NMFS can issue incidental take regulations under section
101(a)(5)(A) of the MMPA, it must make a finding that the total taking
will have a ``negligible impact'' on the affected ``species or stocks''
of marine mammals. NMFS' and U.S. Fish and Wildlife Service's
implementing regulations for section 101(a)(5)(A) both define
``negligible impact'' 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.'' (50 CFR 216.103 and 50 CFR
18.27(c)) Recruitment (i.e., reproduction) and survival rates are used
to determine population growth rates \1\ and, therefore are considered
in evaluating population level impacts.
---------------------------------------------------------------------------

\1\ A growth rate can be positive, negative, or flat.
---------------------------------------------------------------------------

As we stated in the preamble to the final rule for the incidental
take implementing regulations, not every population-level impact
violates the negligible impact requirement. The negligible impact
standard does not require a finding that the anticipated take will have
``no effect'' on population numbers or growth rates: The statutory
standard does not require that the same recovery rate be maintained,
rather that no significant effect on annual rates of recruitment or
survival occurs. [T]he key factor is the significance of the level of
impact on rates of recruitment or survival. See 54 FR 40338, 40341-42
(September 29, 1989).
While some level of impact on population numbers or growth rates of
a species or stock may occur and still satisfy the negligible impact
requirement--even without consideration of mitigation--the least
practicable adverse impact provision separately requires NMFS to
prescribe 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 [. . .],
which are typically identified as mitigation measures.'' \2\
---------------------------------------------------------------------------

\2\ For purposes of this discussion we omit reference to the
language in the standard for least practicable adverse impact that
says we also must mitigate for subsistence impacts because they are
not at issue in this regulation.
---------------------------------------------------------------------------

The negligible impact and least practicable adverse impact
standards in the MMPA both call for evaluation at the level of the
``species or stock.'' The MMPA does not define the term ``species.''
However, Merriam-Webster defines ``species'' to include ``related
organisms or populations potentially capable of interbreeding.'' See
www.merriam-webster.com/dictionary/species (emphasis added). The MMPA
defines ``stock'' as a group of marine mammals of the same species or
smaller taxa in a common spatial arrangement, that interbreed when
mature. 16 U.S.C. 1362(11). The definition of ``population'' is ``a
group of interbreeding organisms that represents the level of
organization at which speciation begins.'' www.merriam-webster.com/dictionary/population. The definition of ``population'' is strikingly
similar to the MMPA's definition of ``stock,'' with both involving
groups of individuals that belong to the same species and located in a
manner that allows for interbreeding.'' In fact, the term ``stock'' in
the MMPA is interchangeable with the statutory term ``population
stock.'' 16 U.S.C. 1362(11). Thus, the MMPA terms ``species'' and
``stock'' both relate to populations, and it is therefore appropriate
to view both the negligible impact standard and the least practicable
adverse impact standard, both of which call for evaluation at the level
of the species or stock, as having a population-level focus.
This interpretation is consistent with Congress's statutory
findings for enacting the MMPA, nearly all of which are most applicable
at the species or stock (i.e., population) level. See 16 U.S.C. 1361
(finding that it is species and population stocks that are or may be in
danger of extinction or depletion; that it is species and population
stocks that should not diminish beyond being significant functioning
elements of their ecosystems; and that it is species and population
stocks that should not be permitted to diminish below their optimum
sustainable population level). Annual rates of recruitment (i.e.,
reproduction) and survival are the key biological metrics used in the
evaluation of population-level impacts, and accordingly these same
metrics are also used in the evaluation of population level impacts for
the least practicable adverse impact standard.
Recognizing this common focus of the least practicable adverse
impact and negligible impact provisions on the ``species or stock''
does not mean we conflate the two standards; despite some common
statutory language, we recognize the two provisions are different and
have different functions. First, a negligible impact finding is
required before NMFS can issue an incidental take authorization.
Although it is acceptable to use mitigation measures to reach a
negligible impact finding, 50 CFR 216.104(c), no amount of mitigation
can enable NMFS to issue an incidental take authorization for an
activity that still would not meet the negligible impact standard.
Moreover, even where NMFS can reach a negligible impact finding--which
we emphasize does allow for the possibility of some ``negligible''
population-level impact--the agency must still prescribe measures that
will effect the least practicable amount of adverse impact upon the
affected species or stock.
Section 101(a)(5)(A)(i)(II) requires NMFS to issue, in conjunction
with its authorization, binding--and enforceable--restrictions (in the
form of regulations) setting forth how the activity must be conducted,
thus

[[Page 11044]]

ensuring the activity has the ``least practicable adverse impact'' on
the affected species or stocks. In situations where mitigation is
specifically needed to reach a negligible impact determination, section
101(a)(5)(A)(i)(II) also provides a mechanism for ensuring compliance
with the ``negligible impact'' requirement. Finally, we reiterate that
the least practicable adverse impact standard also requires
consideration of measures for marine mammal habitat, with particular
attention to rookeries, mating grounds, and other areas of similar
significance, and for subsistence impacts; whereas the negligible
impact standard is concerned solely with conclusions about the impact
of an activity on annual rates of recruitment and survival.\3\
---------------------------------------------------------------------------

\3\ Outside of the military readiness context, mitigation may
also be appropriate to ensure compliance with the ``small numbers''
language in MMPA sections 101(a)(5)(A) and (D).
---------------------------------------------------------------------------

In NRDC v. Pritzker, the Court stated, ``[t]he statute is properly
read to mean that even if population levels are not threatened
significantly, still the agency must adopt mitigation measures aimed at
protecting marine mammals to the greatest extent practicable in light
of military readiness needs.'' Id. at 1134 (emphases added). This
statement is consistent with our understanding stated above that even
when the effects of an action satisfy the negligible impact standard
(i.e., in the Court's words, ``population levels are not threatened
significantly''), still the agency must prescribe mitigation under the
least practicable adverse impact standard. However, as the statute
indicates, the focus of both standards is ultimately the impact on the
affected ``species or stock,'' and not solely focused on or directed at
the impact on individual marine mammals.
We have carefully reviewed and considered the Ninth Circuit's
opinion in NRDC v. Pritzker in its entirety. While the Court's
reference to ``marine mammals'' rather than ``marine mammal species or
stocks'' in the italicized language above might be construed as a
holding that the least practicable adverse impact standard applies at
the individual ``marine mammal'' level, i.e., that NMFS must require
mitigation to minimize impacts to each individual marine mammal unless
impracticable, we believe such an interpretation reflects an incomplete
appreciation of the Court's holding. In our view, the opinion as a
whole turned on the Court's determination that NMFS had not given
separate and independent meaning to the least practicable adverse
impact standard apart from the negligible impact standard, and further,
that the Court's use of the term ``marine mammals'' was not addressing
the question of whether the standard applies to individual animals as
opposed to the species or stock as a whole. We recognize that while
consideration of mitigation can play a role in a negligible impact
determination, consideration of mitigation measures extends beyond that
analysis. In evaluating what mitigation measures are appropriate NMFS
considers the potential impacts of the Proposed Activity, the
availability of measures to minimize those potential impacts, and the
practicability of implementing those measures, as we describe below.

Implementation of Least Practicable Adverse Impact Standard

Given this most recent Court decision, we further clarify how we
determine whether a measure or set of measures meets the ``least
practicable adverse impact'' standard. Our evaluation of potential
mitigation measures includes consideration of two primary factors:
(1) The manner in which, and the degree to which, implementation of
the potential measure(s) is expected to reduce adverse impacts to
marine mammal species or stocks, their habitat, and their availability
for subsistence uses (where relevant). This analysis considers such
things as the nature of the potential adverse impact (such as
likelihood, scope, and range), the likelihood that the measure will be
effective if implemented, and the likelihood of successful
implementation.
(2) The practicability of the measures for applicant
implementation. Practicability of implementation may consider such
things as cost, impact on operations, and, in the case of a military
readiness activity, specifically considers personnel safety,
practicality of implementation, and impact on the effectiveness of the
military readiness activity. 16 U.S.C. 1371(a)(5)(A)(ii).
While the language of the least practicable adverse impact standard
calls for minimizing impacts to affected species or stocks, we
recognize that the reduction of impacts to those species or stocks
accrues through the application of mitigation measures that limit
impacts to individual animals. Accordingly, NMFS' analysis focuses on
measures designed to avoid or minimize impacts on marine mammals from
activities that are likely to increase the probability or severity of
population-level effects.
While direct evidence of impacts to species or stocks from a
specified activity is not always available for every activity type, and
additional study is still needed to describe how specific disturbance
events affect the fitness of individuals of certain species, there have
been significant improvements in understanding the process by which
disturbance effects are translated to the population. With recent
scientific advancements (both marine mammal energetic research and the
development of energetic frameworks), the relative likelihood or degree
of impacts on species or stocks may typically be predicted given a
detailed understanding of the activity, the environment, and the
affected species or stocks. This same information is used in the
development of mitigation measures and helps us understand how
mitigation measures contribute to lessening effects to species or
stocks. We also acknowledge that there is always the potential that new
information, or a new recommendation that we had not previously
considered, becomes available and necessitates reevaluation of
mitigation measures (which may be addressed through adaptive
management) to see if further reduction of population impacts are
possible and practicable.
In the evaluation of specific measures, the details of the
specified activity will necessarily inform each of the two primary
factors discussed above (expected reduction of impacts and
practicability), and will be carefully considered to determine the
types of mitigation that are appropriate under the least practicable
adverse impact standard. Analysis of how a potential mitigation measure
may reduce adverse impacts on a marine mammal stock or species,
consideration of personnel safety, practicality of implementation, and
consideration of the impact on effectiveness of military readiness
activities are not issues that can be meaningfully evaluated through a
yes/no lens. The manner in which, and the degree to which,
implementation of a measure is expected to reduce impacts, as well as
its practicability in terms of these considerations, can vary widely.
For example, a time/area restriction could be of very high value for
decreasing population-level impacts (e.g., avoiding disturbance of
feeding females in an area of established biological importance) or it
could be of lower value (e.g., decreased disturbance in an area of high
productivity but of less firmly established biological importance).
Regarding practicability, a measure might involve operational

[[Page 11045]]

restrictions in an area or time that impedes the Navy's ability to
detect or track enemy submarines (higher impact on mission
effectiveness), or it could mean delaying a small in-port training
event by 30 minutes to avoid exposure of a marine mammal to injurious
levels of sound (lower impact). A responsible evaluation of ``least
practicable adverse impact'' will consider the factors along these
realistic scales. Accordingly, the greater the likelihood that a
measure will contribute to reducing the probability or severity of
adverse impacts to the species or stock, the greater the weight that
measure(s) is given when considered in combination with practicability
to determine the appropriateness of the mitigation measure(s), and vice
versa. In the evaluation of specific measures, the details of the
specified activity will necessarily inform each of the two primary
factors discussed above (expected reduction of impacts and
practicability), and will be carefully considered to determine the
types of mitigation that are appropriate under the least practicable
adverse impact standard. We discuss consideration of these factors in
greater detail below.
1. Reduction of adverse impacts to marine mammal species or stocks
and their habitat.\4\ The emphasis given to a measure's ability to
reduce the impacts on a species or stock considers the degree,
likelihood, and context of the anticipated reduction of impacts to
individuals (and how many individuals) as well as the status of the
species or stock.
---------------------------------------------------------------------------

\4\ We recognize the least practicable adverse impact standard
requires consideration of measures that will address minimizing
impacts on the availability of the species or stocks for subsistence
uses where relevant. Because subsistence uses are not implicated for
this action we do not discuss them. However, a similar framework
would apply for evaluating those measures, taking into account the
MMPA's directive that we make a finding of no unmitigable adverse
impact on the availability of the species or stocks for taking for
subsistence, and the relevant implementing regulations.
---------------------------------------------------------------------------

The ultimate impact on any individual from a disturbance event
(which informs the likelihood of adverse species- or stock-level
effects) is dependent on the circumstances and associated contextual
factors, such as duration of exposure to stressors. Though any proposed
mitigation needs to be evaluated in the context of the specific
activity and the species or stocks affected, measures with the
following types of goals are often applied to reduce the likelihood or
severity of adverse species- or stock-level impacts: Avoiding or
minimizing injury or mortality; limiting interruption of known feeding,
breeding, mother/young, or resting behaviors; minimizing the
abandonment of important habitat (temporally and spatially); minimizing
the number of individuals subjected to these types of disruptions; and
limiting degradation of habitat. Mitigating these types of effects is
intended to reduce the likelihood that the activity will result in
energetic or other types of impacts that are more likely to result in
reduced reproductive success or survivorship. It is also important to
consider the degree of impacts that were expected in the absence of
mitigation in order to assess the added value of any potential
measures. Finally, because the least practicable adverse impact
standard authorizes NMFS to weigh a variety of factors when evaluating
appropriate mitigation measures, it does not compel mitigation for
every kind of take, or every individual taken, even when practicable
for implementation by the applicant.
The status of the species or stock is also relevant in evaluating
the appropriateness of certain mitigation measures in the context of
least practicable adverse impact. The following are examples of factors
that may (either alone, or in combination) result in greater emphasis
on the importance of a mitigation measure in reducing impacts on a
species or stock: The stock is known to be decreasing or status is
unknown, but believed to be declining; the known annual mortality (from
any source) is approaching or exceeding the Potential Biological
Removal (PBR) level (as defined in 16 U.S.C. 1362(20)); the affected
species or stock is a small, resident population; or the stock is
involved in an unusual mortality event (UME) or has other known
vulnerabilities, such as recovering from an oil spill.
Habitat mitigation, particularly as it relates to rookeries, mating
grounds, and areas of similar significance, is also relevant to
achieving the standard and can include measures such as reducing
impacts of the activity on known prey utilized in the activity area or
reducing impacts on physical habitat. As with species- or stock-related
mitigation, the emphasis given to a measure's ability to reduce impacts
on a species or stock's habitat considers the degree, likelihood, and
context of the anticipated reduction of impacts to habitat. Because
habitat value is informed by marine mammal presence and use, in some
cases there may be overlap in measures for the species or stock and for
use of habitat.
We consider available information indicating the likelihood of any
measure to accomplish its objective. If evidence shows that a measure
has not typically been effective or successful, then either that
measure should be modified or the potential value of the measure to
reduce effects is lowered.
2. Practicability. Factors considered may include cost, impact on
operations, and, in the case of a military readiness activity,
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity (16 U.S.C.
1371(a)(5)(A)(ii)).
NMFS reviewed the proposed activities and the suite of proposed
mitigation measures as described in the Navy's rulemaking and LOA
application and the AFTT DEIS/OEIS to determine if they would result in
the least practicable adverse effect on marine mammals. NMFS worked
with the Navy in the development of the Navy's initially proposed
measures, which are informed by years of experience and monitoring. A
complete discussion of the evaluation process used by the Navy to
develop, assess, and select mitigation measures, which was informed by
input form NMFS, can be found in Chapter 5 (Mitigation) of the AFTT
DEIS/OEIS and is summarized below. The Navy proposes to implement
mitigation measures to avoid potential impacts from acoustic,
explosive, and physical disturbance and strike stressors.
In summary, the Navy proposes a suite of procedural mitigation
measures that we expect to result in a reduction in the probability
and/or severity of impacts expected to result from acute exposure to
acoustic sources or explosives, ship strike, and impacts to marine
mammal habitat. Specifically, the Navy uses a combination of delayed
starts, powerdowns, and shutdowns to avoid serious injury or mortality,
minimize the likelihood or severity of PTS or other injury, and reduce
instances of TTS or more severe behavioral disruption. Additional
procedural vessel operation mitigation is included to minimize or avoid
the likelihood of ship strikes, with an additional focus on right
whales. The Navy also proposes to implement time/area restrictions
intended to reduce take of marine mammals in areas or times where they
are known to engage in important behaviors, such as feeding or calving,
where the disruption of those behaviors would be more likely to result
in population-level impacts. The Navy assessed the practicability of
the measures it proposed in the context of personnel safety,
practicality, and their impacts on the Navy's ability to meet their
Title 10 requirements and found that the measures were supportable.
NMFS has evaluated the mitigation measures the Navy has proposed and
the measures will both sufficiently reduce impacts on the affected
marine

[[Page 11046]]

mammal species and stocks and their habitats and be practicable for
Navy implementation. Therefore, the mitigation measures assure that
Navy's activities will have the least practicable adverse impact on the
species and stocks and their habitat.
The Navy also evaluated several measures in the Navy's AFTT DEIS/
OEIS that are not included in the Navy's rulemaking and LOA application
for the Proposed Activity, and NMFS concurs that their inclusion was
not appropriate to support the least practicable adverse impact
standard based on our assessment. In summary, first, commenters
sometimes recommend that the Navy reduce their overall amount of
training, reduce explosive use, modify their sound sources, completely
replace live training with computer simulation, or include time of day
restrictions. All of these proposed measures could potentially reduce
the number of marine mammals taken, via direct reduction of the
activities or amount of sound energy put in the water. However, as the
Navy has described in Chapter 5 of the AFTT DEIS/OEIS, they need to
train and test in the conditions in which they fight--and these types
of modifications fundamentally change the activity in a manner that
would not support the purpose and need for the training and testing
(i.e., are entirely impracticable) and therefore are not considered
further. Second, the Navy evaluated a suite of additional potential
procedural mitigation measures, including increased mitigation zones,
additional passive acoustic and visual monitoring, and decreased vessel
speeds. Some of these measures have the potential to incrementally
reduce take to some degree in certain circumstances, though the degree
to which this would occur is typically low or uncertain. However, as
described in the Navy's analysis, the impracticability of
implementation outweighed the potential reduction of impacts to marine
mammal species or stocks (see Chapter 5 of AFTT DEIS/OEIS). NMFS
reviewed the Navy's evaluation and concurs that the measures proposed
by the Navy and discussed above affect the least practicable adverse
impact on the marine mammal species or stocks and their habitat and
that the addition of these other measures would not meet that standard.
Below are the mitigation measures that NMFS determined will ensure
the least practicable adverse impact on all affected species and stocks
and their habitat, including the specific considerations for military
readiness activities. The following sections summarize the mitigation
measures that will be implemented in association with the training and
testing activities analyzed in this document. The Navy's mitigation
measures are organized into two categories: procedural mitigation and
mitigation areas.

Procedural Mitigation

Procedural mitigation is mitigation that the Navy will implement
whenever and wherever an applicable training or testing activity takes
place within the AFTT Study Area. The Navy customizes procedural
mitigation for each applicable activity category or stressor.
Procedural mitigation generally involves: (1) The use of one or more
trained Lookouts to diligently observe for specific biological
resources (including marine mammals) within a mitigation zone, (2)
requirements for Lookouts to immediately communicate sightings of
specific biological resources to the appropriate watch station for
information dissemination, and (3) requirements for the watch station
to implement mitigation (e.g., halt an activity) until certain
recommencement conditions have been met. The first procedural
mitigation (Table 42) is designed to aid Lookouts and other applicable
personnel with their observation, environmental compliance, and
reporting responsibilities. The remainder of the procedural mitigations
(Tables 43 through Tables 62) are organized by stressor type and
activity category and includes acoustic stressors (i.e., active sonar,
airguns, pile driving, weapons firing noise), explosive stressors
(i.e., sonobuoys, torpedoes, medium-caliber and large-caliber
projectiles, missiles and rockets, bombs, sinking exercises, mines,
anti-swimmer grenades, line charge testing and ship shock trials), and
physical disturbance and strike stressors (i.e., vessel movement, towed
in-water devices, small-, medium-, and large-caliber non-explosive
practice munitions, non-explosive missiles and rockets, non-explosive
bombs and mine shapes).

Table 42--Procedural Mitigation for Environmental Awareness and
Education
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
All training and testing activities, as applicable.
Mitigation Zone Size and Mitigation Requirements:
Appropriate personnel involved in mitigation and training
or testing activity reporting under the Proposed Activity will
complete one or more modules of the U.S Navy Afloat Environmental
Compliance Training Series, as identified in their career path
training plan. Modules include:
&cir&; Introduction to the U.S. Navy Afloat Environmental
Compliance Training Series. The introductory module provides
information on environmental laws (e.g., ESA, MMPA) and the
corresponding responsibilities that are relevant to Navy
training and testing activities. The material explains why
environmental compliance is important in supporting the Navy's
commitment to environmental stewardship
&cir&; Marine Species Awareness Training. All bridge watch
personnel, Commanding Officers, Executive Officers, maritime
patrol aircraft aircrews, anti[hyphen]submarine warfare and
mine warfare rotary-wing aircrews, Lookouts, and equivalent
civilian personnel must successfully complete the Marine
Species Awareness Training prior to standing watch or serving
as a Lookout. The Marine Species Awareness Training provides
information on sighting cues, visual observation tools and
techniques, and sighting notification procedures. Navy
biologists developed Marine Species Awareness Training to
improve the effectiveness of visual observations for biological
resources, focusing on marine mammals and sea turtles, and
including floating vegetation, jellyfish aggregations, and
flocks of seabirds.
&cir&; U.S. Navy Protective Measures Assessment Protocol. This
module provides the necessary instruction for accessing
mitigation requirements during the event planning phase using
the Protective Measures Assessment Protocol software tool.
&cir&; U.S. Navy Sonar Positional Reporting System and Marine
Mammal Incident Reporting. This module provides instruction on
the procedures and activity reporting requirements for the
Sonar Positional Reporting System and marine mammal incident
reporting.
------------------------------------------------------------------------

[[Page 11047]]

Procedural Mitigation for Acoustic Stressors

Mitigation measures for acoustic stressors are provided in Tables
43 through 46.

Procedural Mitigation for Active Sonar

Procedural mitigation for active sonar is described in Table 43
below.

Table 43--Procedural Mitigation for Active Sonar
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Low-frequency active sonar, mid-frequency active sonar,
high-frequency active sonar.
For vessel-based active sonar activities, mitigation
applies only to sources that are positively controlled and deployed
from manned surface vessels (e.g., sonar sources towed from manned
surface platforms).
For aircraft-based active sonar activities, mitigation
applies to sources that are positively controlled and deployed from
manned aircraft that do not operate at high altitudes (e.g., rotary-
wing aircraft). Mitigation does not apply to active sonar sources
deployed from unmanned aircraft or aircraft operating at high
altitudes (e.g., maritime patrol aircraft).
Number of Lookouts and Observation Platform:
Hull-mounted sources:
[cir] Platforms without space or manning restrictions while
underway: 2 Lookouts at the forward part of the ship.
[cir] Platforms with space or manning restrictions while
underway: 1 Lookout at the forward part of a small boat or
ship.
[cir] Platforms using active sonar while moored or at anchor
(including pierside): 1 Lookout.
[cir] Pierside sonar testing activities at Port Canaveral,
Florida and Kings Bay, Georgia: 4 Lookouts.
Sources that are not hull-mounted:
[cir] 1 Lookout on the ship or aircraft conducting the activity.
Mitigation Zone Size and Mitigation Requirements:
Prior to the start of the activity (e.g., when maneuvering
on station), observe for floating vegetation and marine mammals; if
resource is observed, do not commence use of active sonar.
Low-frequency active sonar at or above 200 dB and hull-
mounted mid-frequency active sonar will implement the following
mitigation zones:
[cir] During the activity, observe for marine mammals; power
down active sonar transmission by 6 dB if resource is observed
within 1,000 yd of the sonar source; power down by an
additional 4 dB (10 dB total) if resource is observed within
500 yd of the sonar source; and cease transmission if resource
is observed within 200 yd of the sonar source.
Low-frequency active sonar below 200 dB, mid-frequency
active sonar sources that are not hull mounted, and high-frequency
active sonar will implement the following mitigation zone:
[cir] During the activity, observe for marine mammals; cease
active sonar transmission if resource is observed within 200 yd
of the sonar source.
To allow a sighted marine mammal to leave the mitigation
zone, the Navy will not recommence active sonar transmission until
one of the recommencement conditions has been met: (1) The animal
is observed exiting the mitigation zone; (2) the animal is thought
to have exited the mitigation zone based on a determination of its
course, speed, and movement relative to the sonar source; (3) the
mitigation zone has been clear from any additional sightings for 10
min. for aircraft-deployed sonar sources or 30 min. for vessel-
deployed sonar sources; (4) for mobile activities, the active sonar
source has transited a distance equal to double that of the
mitigation zone size beyond the location of the last sighting; or
(5) for activities using hull-mounted sonar, the ship concludes
that dolphins are deliberately closing in on the ship to ride the
ship's bow wave, and are therefore out of the main transmission
axis of the sonar (and there are no other marine mammal sightings
within the mitigation zone).
The Navy will notify the Port Authority prior to the
commencement of pierside sonar testing activities at Port
Canaveral, Florida and Kings Bay, Georgia. At these locations, the
Navy will conduct active sonar activities during daylight hours to
ensure adequate sightability of manatees, and will equip Lookouts
with polarized sunglasses. After completion of pierside sonar
testing activities at Port Canaveral and Kings Bay, the Navy will
continue to observe for marine mammals for 30 min within the
mitigation zone. The Navy will implement a reduction of at least 36
dB from full power for mid-frequency active sonar transmissions at
Kings Bay. The Navy will communicate sightings of manatees made
during or after pierside sonar testing activities at Kings Bay to
the Georgia Department of Natural Resources sightings hotline, Base
Natural Resources Manager, and Port Operations. Communications will
include information on the time and location of a sighting, the
number and size of animals sighted, a description of any research
tags (if present), and the animal's direction of travel. Port
Operations will disseminate the sightings information to other
vessels operating near the sighting and will keep logs of all
manatee sightings.
------------------------------------------------------------------------

Procedural Mitigation for Airguns

Procedural mitigation for airguns is described in Table 44 below.

[[Page 11048]]

Table 44--Procedural Mitigation for Airguns
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Airguns.
Number of Lookouts and Observation Platform:
1 Lookout positioned on a ship or pierside.
Mitigation Zone Size and Mitigation Requirements:
150 yd around the airgun:
[cir] Prior to the start of the activity (e.g., when maneuvering
on station), observe for floating vegetation, and marine
mammals; if resource is observed, do not commence use of
airguns.
[cir] During the activity, observe for marine mammals; if
resource is observed, cease use of airguns.
[cir] To allow a sighted marine mammal to leave the mitigation
zone, the Navy will not recommence the use of airguns until one
of the recommencement conditions has been met: (1) The animal
is observed exiting the mitigation zone; (2) the animal is
thought to have exited the mitigation zone based on a
determination of its course, speed, and movement relative to
the airgun; (3) the mitigation zone has been clear from any
additional sightings for 30 min.; or (4) for mobile activities,
the airgun has transited a distance equal to double that of the
mitigation zone size beyond the location of the last sighting.
------------------------------------------------------------------------

Procedural Mitigation for Pile Driving

Procedural mitigation for pile driving is described in Table 45
below.

Table 45--Procedural Mitigation for Pile Driving
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Pile driving and pile extraction sound during Elevated
Causeway System training.
Number of Lookouts and Observation Platform:
1 Lookout positioned on the shore, the elevated causeway,
or a small boat.
Mitigation Zone Size and Mitigation Requirements:
100 yd around the pile driver:
[cir] 30 min prior to the start of the activity, observe for
floating vegetation and marine mammals; if resource is
observed, do not commence impact pile driving or vibratory pile
extraction.
[cir] During the activity, observe for marine mammals; if
resource is observed, cease impact pile driving or vibratory
pile extraction.
[cir] To allow a sighted marine mammal to leave the mitigation
zone, the Navy will not recommence pile driving until one of
the recommencement conditions has been met: (1) The animal is
observed exiting the mitigation zone; (2) the animal is thought
to have exited the mitigation zone based on a determination of
its course, speed, and movement relative to the pile driving
location; or (3) the mitigation zone has been clear from any
additional sightings for 30 min.
------------------------------------------------------------------------

Procedural Mitigation for Weapons Firing Noise

Procedural mitigation for weapons firing noise is described in
Table 46 below.

Table 46--Procedural Mitigation for Weapons Firing Noise
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Weapons firing noise associated with large-caliber gunnery
activities.
Number of Lookouts and Observation Platform:
1 Lookout positioned on the ship conducting the firing.
Depending on the activity, the Lookout could be the same as
the one described in Table 49 for Explosive Medium-Caliber and
Large-Caliber Projectiles or in Table 60 for Small-, Medium-, and
Large-Caliber Non-Explosive Practice Munitions.
Mitigation Zone Size and Mitigation Requirements:
30[deg] on either side of the firing line out to 70 yd from
the muzzle of the weapon being fired:
[cir] Prior to the start of the activity, observe for floating
vegetation, and marine mammals; if resource is observed, do not
commence weapons firing.
[cir] During the activity, observe for marine mammals; if
resource is observed, cease weapons firing.
[cir] To allow a sighted marine mammal to leave the mitigation
zone, the Navy will not recommence weapons firing until one of
the recommencement conditions has been met: (1) The animal is
observed exiting the mitigation zone; (2) the animal is thought
to have exited the mitigation zone based on a determination of
its course, speed, and movement relative to the firing ship;
(3) the mitigation zone has been clear from any additional
sightings for 30 min.; or (4) for mobile activities, the firing
ship has transited a distance equal to double that of the
mitigation zone size beyond the location of the last sighting.
------------------------------------------------------------------------

[[Page 11049]]

Procedural Mitigation for Explosive Stressors

Mitigation measures for explosive stressors are provided in Tables
47 through 57.

Procedural Mitigation for Explosive Sonobuoys

Procedural mitigation for explosive sonobuoys is described in Table
47 below.

Table 47--Procedural Mitigation for Explosive Sonobuoys
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Explosive sonobuoys.
Number of Lookouts and Observation Platform:
1 Lookout positioned in an aircraft or on small boat.
Mitigation Zone Size and Mitigation Requirements:
600 yd around an explosive sonobuoy:
[cir] Prior to the start of the activity (e.g., during
deployment of a sonobuoy field, which typically lasts 20-30
min.), conduct passive acoustic monitoring for marine mammals,
and observe for floating vegetation and marine mammals; if
resource is visually observed, do not commence sonobuoy or
source/receiver pair detonations.
[cir] During the activity, observe for marine mammals; if
resource is observed, cease sonobuoy or source/receiver pair
detonations.
[cir] To allow a sighted marine mammal to leave the mitigation
zone, the Navy will not recommence the use of explosive
sonobuoys until one of the recommencement conditions has been
met: (1) The animal is observed exiting the mitigation zone;
(2) the animal is thought to have exited the mitigation zone
based on a determination of its course, speed, and movement
relative to the sonobuoy; or (3) the mitigation zone has been
clear from any additional sightings for 10 min. when the
activity involves aircraft that have fuel constraints, or 30
min. when the activity involves aircraft that are not typically
fuel constrained.
------------------------------------------------------------------------

Procedural Mitigation for Explosive Torpedoes

Procedural mitigation for explosive torpedoes is described in Table
48 below.

Table 48--Procedural Mitigation for Explosive Torpedoes
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Explosive torpedoes.
Number of Lookouts and Observation Platform:
1 Lookout positioned in an aircraft.
Mitigation Zone Size and Mitigation Requirements:
2,100 yd around the intended impact location:
[cir] Prior to the start of the activity (e.g., during
deployment of the target), the Navy will conduct passive
acoustic monitoring for marine mammals, and observe for
floating vegetation, jellyfish aggregations, and marine
mammals; if resource is visually observed, the Navy will not
commence firing.
[cir] During the activity, the Navy will observe for marine
mammals and jellyfish aggregations; if resource is observed,
the Navy will cease firing.
[cir] To allow a sighted marine mammal to leave the mitigation
zone, the Navy will not recommence firing until one of the
recommencement conditions has been met: (1) The animal is
observed exiting the mitigation zone; (2) the animal is thought
to have exited the mitigation zone based on a determination of
its course, speed, and movement relative to the intended impact
location; or (3) the mitigation zone has been clear from any
additional sightings for 10 min. when the activity involves
aircraft that have fuel constraints, or 30 min. when the
activity involves aircraft that are not typically fuel
constrained.
[cir] After completion of the activity, the Navy will observe
for marine mammals; if any injured or dead resources are
observed, the Navy will follow established incident reporting
procedures.
------------------------------------------------------------------------

Procedural Mitigation for Medium- and Large-Caliber Projectiles

Procedural mitigation for medium- and large-caliber projectiles is
described in Table 49 below.

Table 49--Procedural Mitigation for Explosive Medium-Caliber and Large-
Caliber Projectiles
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Gunnery activities using explosive medium-caliber and large-
caliber projectiles.
Mitigation applies to activities using a surface target.
Number of Lookouts and Observation Platform:

[[Page 11050]]

1 Lookout on the vessel or aircraft conducting the
activity.
For activities using explosive large-caliber projectiles,
depending on the activity, the Lookout could be the same as the one
described in Table 46 for Weapons Firing Noise.
Mitigation Zone Size and Mitigation Requirements:
200 yd around the intended impact location for air-to-
surface activities using explosive medium-caliber projectiles,
600 yd around the intended impact location for surface-to-
surface activities using explosive medium-caliber projectiles, or
1,000 yd around the intended impact location for surface-to-
surface activities using explosive large-caliber projectiles:
[cir] Prior to the start of the activity (e.g., when maneuvering
on station), the Navy will observe for floating vegetation and
marine mammals; if resource is observed, the Navy will not
commence firing.
[cir] During the activity, the Navy will observe for marine
mammals; if resource is observed, the Navy will cease firing.
[cir] To allow a sighted marine mammal to leave the mitigation
zone, the Navy will not recommence firing until one of the
recommencement conditions has been met: (1) The animal is
observed exiting the mitigation zone; (2) the animal is thought
to have exited the mitigation zone based on a determination of
its course, speed, and movement relative to the intended impact
location; (3) the mitigation zone has been clear from any
additional sightings for 10 min. for aircraft-based firing or
30 min. for vessel-based firing; or (4) for activities using
mobile targets, the intended impact location has transited a
distance equal to double that of the mitigation zone size
beyond the location of the last sighting.
------------------------------------------------------------------------

Procedural Mitigation for Explosive Missiles and Rockets

Procedural mitigation for explosive missiles and rockets is
described in Table 50 below.

Table 50--Procedural Mitigation for Explosive Missiles and Rockets
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Aircraft-deployed explosive missiles and rockets.
Mitigation applies to activities using a surface target.
Number of Lookouts and Observation Platform:
1 Lookout positioned in an aircraft.
Mitigation Zone Size and Mitigation Requirements:
900 yd around the intended impact location for missiles or
rockets with 0.6-20 lb net explosive weight, or
2,000 yd around the intended impact location for missiles
with 21-500 lb net explosive weight:
[cir] Prior to the start of the activity (e.g., during a fly-
over of the mitigation zone), the Navy will observe for
floating vegetation and marine mammals; if resource is
observed, the Navy will not commence firing.
[cir] During the activity, the Navy will observe for marine
mammals; if resource is observed, the Navy will cease firing.
[cir] To allow a sighted marine mammal to leave the mitigation
zone, the Navy will not recommence firing until one of the
recommencement conditions has been met: (1) The animal is
observed exiting the mitigation zone; (2) the animal is thought
to have exited the mitigation zone based on a determination of
its course, speed, and movement relative to the intended impact
location; or (3) the mitigation zone has been clear from any
additional sightings for 10 min. when the activity involves
aircraft that have fuel constraints, or 30 min. when the
activity involves aircraft that are not typically fuel
constrained.
------------------------------------------------------------------------

Procedural Mitigation for Explosive Bombs

Procedural mitigation for explosive bombs is described in Table 51
below.

Table 51--Procedural Mitigation for Explosive Bombs
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Explosive bombs.
Number of Lookouts and Observation Platform:
1 Lookout positioned in the aircraft conducting the
activity.
Mitigation Zone Size and Mitigation Requirements:
2,500 yd around the intended target:
[cir] Prior to the start of the activity (e.g., when arriving on
station), the Navy will observe for floating vegetation and
marine mammals; if resource is observed, the Navy will not
commence bomb deployment.
[cir] During target approach, the Navy will observe for marine
mammals; if resource is observed, the Navy will cease bomb
deployment.

[[Page 11051]]

[cir] To allow a sighted marine mammal to leave the mitigation
zone, the Navy will not recommence bomb deployment until one of
the recommencement conditions has been met: (1) The animal is
observed exiting the mitigation zone; (2) the animal is thought
to have exited the mitigation zone based on a determination of
its course, speed, and movement relative to the intended
target; (3) the mitigation zone has been clear from any
additional sightings for 10 min.; or (4) for activities using
mobile targets, the intended target has transited a distance
equal to double that of the mitigation zone size beyond the
location of the last sighting.
------------------------------------------------------------------------

Procedural Mitigation for Sinking Exercises

Procedural mitigation for sinking exercises is described in Table
52 below.

Table 52--Procedural Mitigation for Sinking Exercises
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Sinking exercises.
Number of Lookouts and Observation Platform:
2 Lookouts (one positioned in an aircraft and one on a
vessel).
Mitigation Zone Size and Mitigation Requirements:
2.5 nmi around the target ship hulk:
[cir] 90 min. prior to the first firing, the Navy will conduct
aerial observations for floating vegetation, jellyfish
aggregations, and marine mammals; if resource is observed, the
Navy will not commence firing.
[cir] During the activity, the Navy will conduct passive
acoustic monitoring and visually observe for marine mammals
from the vessel; if resource is visually observed, the Navy
will cease firing.
[cir] Immediately after any planned or unplanned breaks in
weapons firing of longer than 2 hours, observe for marine
mammals from the aircraft and vessel; if resource is observed,
the Navy will not commence firing.
[cir] To allow a sighted marine mammal to leave the mitigation
zone, the Navy will not recommence firing until one of the
recommencement conditions has been met: (1) The animal is
observed exiting the mitigation zone; (2) the animal is thought
to have exited the mitigation zone based on a determination of
its course, speed, and movement relative to the target ship
hulk; or (3) the mitigation zone has been clear from any
additional sightings for 30 min.
[cir] For 2 hours after sinking the vessel (or until sunset,
whichever comes first), the Navy will observe for marine
mammals; if any injured or dead resources are observed, the
Navy will allow established incident reporting procedures.
------------------------------------------------------------------------

Procedural Mitigation for Explosive Mine Countermeasure and
Neutralization Activities

Procedural mitigation for explosive mine countermeasure and
neutralization activities is described in Table 53 below.

Table 53--Procedural Mitigation for Explosive Mine Countermeasure and
Neutralization Activities
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Explosive mine countermeasure and neutralization
activities.
Number of Lookouts and Observation Platform:
1 Lookout positioned on a vessel or in an aircraft when
using up to 0.1-5 lb net explosive weight charges.
2 Lookouts (one in an aircraft and one on a small boat)
when using up to 6-650 lb net explosive weight charges.
Mitigation Zone Size and Mitigation Requirements:
600 yd around the detonation site for activities using 0.1-
5 lb net explosive weight, or
2,100 yd around the detonation site for activities using 6-
650 lb net explosive weight (including high explosive target
mines):
[cir] Prior to the start of the activity (e.g., when maneuvering
on station; typically, 10 min. when the activity involves
aircraft that have fuel constraints, or 30 min. when the
activity involves aircraft that are not typically fuel
constrained), the Navy will observe for floating vegetation and
marine mammals; if resource is observed, the Navy will not
commence detonations.
[cir] During the activity, the Navy will observe for marine
mammals; if resource is observed, the Navy will cease
detonations.
[cir] To allow a sighted marine mammal to leave the mitigation
zone, the Navy will not recommence detonations until one of the
recommencement conditions has been met: (1) The animal is
observed exiting the mitigation zone; (2) the animal is thought
to have exited the mitigation zone based on a determination of
its course, speed, and movement relative to detonation site; or
(3) the mitigation zone has been clear from any additional
sightings for 10 min. when the activity involves aircraft that
have fuel constraints, or 30 min. when the activity involves
aircraft that are not typically fuel constrained.
[cir] After completion of the activity, the Navy will observe
for marine mammals and sea turtles (typically 10 min. when the
activity involves aircraft that have fuel constraints, or 30
min. when the activity involves aircraft that are not typically
fuel constrained); if any injured or dead resources are
observed, the Navy will follow established incident reporting
procedures.
------------------------------------------------------------------------

[[Page 11052]]

Procedural Mitigation for Explosive Mine Neutralization Activities
Involving Navy Divers

Procedural mitigation for explosive mine neutralization activities
involving Navy divers is described in Table 54 below.

Table 54--Procedural Mitigation for Explosive Mine Neutralization
Activities Involving Navy Divers
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Mine neutralization activities involving Navy divers.
Number of Lookouts and Observation Platform:
2 Lookouts (two small boats with one Lookout each, or one
Lookout on a small boat and one in a rotary-wing aircraft) when
implementing the smaller mitigation zone.
4 Lookouts (two small boats with two Lookouts each), and a
pilot or member of an aircrew will serve as an additional Lookout
if aircraft are used during the activity, when implementing the
larger mitigation zone.
Mitigation Zone Size and Mitigation Requirements:
The Navy will not set time-delay firing devices (0.1-20 lb
net explosive weight) to exceed 10 min.
500 yd around the detonation site during activities under
positive control using 0.1-20 lb net explosive weight, or
1,000 yd around the detonation site during all activities
using time-delay fuses (0.1-20 lb net explosive weight) and during
activities under positive control using 21-60 lb net explosive
weight charges:
[cir] Prior to the start of the activity (e.g., when maneuvering
on station for activities under positive control; 30 min for
activities using time-delay firing devices), the Navy will
observe for floating vegetation and marine mammals; if resource
is observed, the Navy will not commence detonations or fuse
initiation.
[cir] During the activity, the Navy will observe for marine
mammals; if resource is observed, the Navy will cease
detonations or fuse initiation.
[cir] All divers placing the charges on mines will support the
Lookouts while performing their regular duties and will report
all marine mammal sightings to their supporting small boat or
Range Safety Officer.
[cir] To the maximum extent practicable depending on mission
requirements, safety, and environmental conditions, boats will
position themselves near the mid-point of the mitigation zone
radius (but outside of the detonation plume and human safety
zone), will position themselves on opposite sides of the
detonation location (when two boats are used), and will travel
in a circular pattern around the detonation location with one
Lookout observing inward toward the detonation site and the
other observing outward toward the perimeter of the mitigation
zone.
[cir] If used, aircraft will travel in a circular pattern around
the detonation location to the maximum extent practicable.
[cir] To allow a sighted marine mammal to leave the mitigation
zone, the Navy will not recommence detonations or fuse
initiation until one of the recommencement conditions has been
met: (1) The animal is observed exiting the mitigation zone;
(2) the animal is thought to have exited the mitigation zone
based on a determination of its course, speed, and movement
relative to the detonation site; or (3) the mitigation zone has
been clear from any additional sightings for 10 min. during
activities under positive control with aircraft that have fuel
constraints, or 30 min. during activities under positive
control with aircraft that are not typically fuel constrained
and during activities using time-delay firing devices.
After completion of an activity using time-delay firing
devices, the Navy will observe for marine mammals for 30 min.; if
any injured or dead resources are observed, the Navy will follow
established incident reporting procedures.
------------------------------------------------------------------------

Procedural Mitigation for Maritime Security Operations--Anti-Swimmer
Grenades

Procedural mitigation for maritime security operations--anti-
swimmer grenades is described in Table 55 below.

Table 55--Procedural Mitigation for Maritime Security Operations--Anti-
Swimmer Grenades
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Maritime Security Operations--Anti-Swimmer Grenades.
Number of Lookouts and Observation Platform:
1 Lookout positioned on the small boat conducting the
activity.
Mitigation Zone Size and Mitigation Requirements:
200 yd around the intended detonation location:
[cir] Prior to the start of the activity (e.g., when maneuvering
on station), the Navy observe for floating vegetation and
marine mammals; if resource is observed, the Navy will not
commence detonations.
[cir] During the activity, the Navy will observe for marine
mammals; if resource is observed, the Navy will cease
detonations.
To allow a sighted marine mammal to leave the mitigation
zone, the Navy will not recommence detonations until one of the
recommencement conditions has been met: (1) The animal is observed
exiting the mitigation zone; (2) the animal is thought to have
exited the mitigation zone based on a determination of its course,
speed, and movement relative to the intended detonation location;
(3) the mitigation zone has been clear from any additional
sightings for 30 min.; or (4) the intended detonation location has
transited a distance equal to double that of the mitigation zone
size beyond the location of the last sighting.
------------------------------------------------------------------------

[[Page 11053]]

Procedural Mitigation for Line Charge Testing

Procedural mitigation for line charge testing is described in Table
56 below.

Table 56--Procedural Mitigation for Line Charge Testing
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Line charge testing.
Number of Lookouts and Observation Platform:
1 Lookout positioned on a vessel.
Mitigation Zone Size and Mitigation Requirements:
900 yd around the intended detonation location:
[cir] Prior to the start of the activity (e.g., when maneuvering
on station), the Navy will observe for floating vegetation and
marine mammals; if resource is observed, the Navy will not
commence detonations.
[cir] During the activity, the Navy will observe for marine
mammals; if resource is observed, the Navy will cease
detonations.
To allow a sighted marine mammal to leave the mitigation
zone, the Navy will not recommence detonations until one of the
recommencement conditions has been met: (1) The animal is observed
exiting the mitigation zone; (2) the animal is thought to have
exited the mitigation zone based on a determination of its course,
speed, and movement relative to the intended detonation location;
or (3) the mitigation zone has been clear from any additional
sightings for 30 min.
------------------------------------------------------------------------

Procedural Mitigation for Ship Shock Trials

Procedural mitigation for ship shock trials is described in Table
57 below.

Table 57--Procedural Mitigation for Ship Shock Trials
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Ship shock trials.
Number of Lookouts and Observation Platform:
A minimum of 10 Lookouts or trained marine species
observers (or a combination thereof) positioned either in an
aircraft or on multiple vessels (i.e., a Marine Animal Response
Team boat and the test ship).
If aircraft are used, Lookouts or trained marine species
observers will be in an aircraft and on multiple vessels.
If aircraft are not used, a sufficient number of additional
Lookouts or trained marine species observers will be used to
provide vessel-based visual observation comparable to that achieved
by aerial surveys.
Mitigation Zone Size and Mitigation Requirements:
The Navy will not conduct ship shock trials in the
Jacksonville Operating Area during North Atlantic right whale
calving season from November 15 through April 15.
The Navy develops detailed ship shock trial monitoring and
mitigation plans approximately 1-year prior to an event and will
continue to provide these to NMFS for review and approval.
Pre-activity planning will include selection of one primary
and two secondary areas where marine mammal populations are
expected to be the lowest during the event, with the primary and
secondary locations located more than 2 nmi from the western
boundary of the Gulf Stream for events in the Virginia Capes Range
Complex or Jacksonville Range Complex.
If it is determined during pre-activity surveys that the
primary area is environmentally unsuitable (e.g., observations of
marine mammals or presence of concentrations of floating
vegetation), the shock trial could be moved to a secondary site in
accordance with the detailed mitigation and monitoring plan
provided to NMFS.
3.5 nmi around the ship hull:
[cir] Prior to the detonation (at the primary shock trial
location) in intervals of 5 hrs., 3 hrs., 40 min., and
immediately before the detonation, the Navy will observe for
floating vegetation and marine mammals; if resource is
observed, the Navy will not trigger the detonation.
[cir] During the activity, the Navy will observe for marine
mammals, large schools of fish, jellyfish aggregations, and
flocks of seabirds; if resource is observed, the Navy will
cease triggering the detonation.
[cir] To allow a sighted marine mammal to leave the mitigation
zone, the Navy will not recommence the triggering of a
detonation until one of the recommencement conditions has been
met: (1) The animal is observed exiting the mitigation zone;
(2) the animal is thought to have exited the mitigation zone
based on a determination of its course, speed, and movement
relative to the ship hull; or (3) the mitigation zone has been
clear from any additional sightings for 30 min.
[cir] After completion of each detonation, the Navy will observe
for marine mammals; if any injured or dead resources are
observed, the Navy will follow established incident reporting
procedures and halt any remaining detonations until the Navy
can consult with NMFS and review or adapt the mitigation, if
necessary.
[cir] After completion of the ship shock trial, the Navy will
conduct additional observations during the following 2 days (at
a minimum) and up to 7 days (at a maximum); if any injured or
dead resources are observed, the Navy will follow established
incident reporting procedures.
------------------------------------------------------------------------

[[Page 11054]]

Procedural Mitigation for Physical Disturbance and Strike Stressors

Mitigation measures for physical disturbance and strike stressors
are provided in Table 58 through Table 62.

Procedural Mitigation for Vessel Movement

Procedural mitigation for vessel movement used during the Proposed
Activities is described in Table 58 below.

Table 58--Procedural Mitigation for Vessel Movement
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Vessel movement.
The mitigation will not be applied if: (1) The vessel's
safety is threatened, (2) the vessel is restricted in its ability
to maneuver (e.g., during launching and recovery of aircraft or
landing craft, during towing activities, when mooring, etc.), or
(3) the vessel is operated autonomously.
Number of Lookouts and Observation Platform:
1 Lookout on the vessel that is underway.
Mitigation Zone Size and Mitigation Requirements:
500 yd around whales:
[cir] When underway, the Navy will observe for marine mammals;
if a whale is observed, the Navy will maneuver to maintain
distance.
200 yd around all other marine mammals (except bow-riding
dolphins and pinnipeds hauled out on man-made navigational
structures, port structures, and vessels):
[cir] When underway, the Navy will observe for marine mammals;
if a marine mammal other than a whale, bow-riding dolphin, or
hauled-out pinniped is observed, the Navy will maneuver to
maintain distance.
------------------------------------------------------------------------

Procedural Mitigation for Towed In-Water Devices

Procedural mitigation for towed in-water devices is described in
Table 59 below.

Table 59--Procedural Mitigation for Towed In-Water Devices
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Towed in-water devices.
Mitigation applies to devices that are towed from a manned
surface platform or manned aircraft.
The mitigation will not be applied if the safety of the
towing platform is threatened.
Number of Lookouts and Observation Platform:
1 Lookout positioned on a manned towing platform.
Mitigation Zone Size and Mitigation Requirements:
250 yd around marine mammals:
[cir] When towing an in-water device, observe for marine
mammals; if resource is observed, maneuver to maintain
distance.
------------------------------------------------------------------------

Procedural Mitigation for Small-, Medium-, and Large-Caliber Non-
Explosive Practice Munitions

Procedural mitigation for small-, medium-, and large-caliber non-
explosive practice munitions is described in Table 60 below.

Table 60--Procedural Mitigation for Small-, Medium-, and Large-Caliber
Non-Explosive Practice Munitions
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Gunnery activities using small-, medium-, and large-caliber
non-explosive practice munitions.
Mitigation applies to activities using a surface target.
Number of Lookouts and Observation Platform:
1 Lookout positioned on the platform conducting the
activity.
Depending on the activity, the Lookout could be the same as
the one described in Table 46 for Weapons Firing Noise.
Mitigation Zone Size and Mitigation Requirements:
[cir] 200 yd around the intended impact location:
[cir] Prior to the start of the activity (e.g., when maneuvering
on station), the Navy will observe for floating vegetation and
marine mammals; if resource is observed, the Navy will not
commence firing.
[cir] During the activity, the Navy will observe for marine
mammals; if resource is observed, the Navy will cease firing.

[[Page 11055]]

[cir] To allow a sighted marine mammal to leave the mitigation
zone, the Navy will not recommence firing until one of the
recommencement conditions has been met: (1) The animal is
observed exiting the mitigation zone; (2) the animal is thought
to have exited the mitigation zone based on a determination of
its course, speed, and movement relative to the intended impact
location; (3) the mitigation zone has been clear from any
additional sightings for 10 min. for aircraft-based firing or
30 min. for vessel-based firing; or (4) for activities using a
mobile target, the intended impact location has transited a
distance equal to double that of the mitigation zone size
beyond the location of the last sighting.
------------------------------------------------------------------------

Procedural Mitigation for Non-Explosive Missiles and Rockets

Procedural mitigation for non-explosive missiles and rockets is
described in Table 61 below.

Table 61--Procedural Mitigation for Non-Explosive Missiles and Rockets
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Aircraft-deployed non-explosive missiles and rockets.
Mitigation applies to activities using a surface target.
Number of Lookouts and Observation Platform:
1 Lookout positioned in an aircraft.
Mitigation Zone Size and Mitigation Requirements:
900 yd around the intended impact location:
[cir] Prior to the start of the activity (e.g., during a fly-
over of the mitigation zone), the Navy will observe for
floating vegetation and marine mammals; if resource is
observed, the Navy will not commence firing.
[cir] During the activity, the Navy will observe for marine
mammals; if resource is observed, the Navy will cease firing.
[cir] To allow a sighted marine mammal to leave the mitigation
zone, the Navy will not recommence firing until one of the
recommencement conditions has been met: (1) The animal is
observed exiting the mitigation zone; (2) the animal is thought
to have exited the mitigation zone based on a determination of
its course, speed, and movement relative to the intended impact
location; or (3) the mitigation zone has been clear from any
additional sightings for 10 min. when the activity involves
aircraft that have fuel constraints, or 30 min. when the
activity involves aircraft that are not typically fuel
constrained.
------------------------------------------------------------------------

Procedural Mitigation for Non-Explosive Bombs and Mine Shapes

Procedural mitigation for non-explosive bombs and mine shapes is
described in Table 62 below.

Table 62--Procedural Mitigation for Non-Explosive Bombs and Mine Shapes
------------------------------------------------------------------------
Procedural mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
Non-explosive bombs.
Non-explosive mine shapes during mine laying activities.
Number of Lookouts and Observation Platform:
1 Lookout positioned in an aircraft.
Mitigation Zone Size and Mitigation Requirements:
1,000 yd around the intended target:
[cir] Prior to the start of the activity (e.g., when arriving on
station), the Navy will observe for floating vegetation and
marine mammals; if resource is observed, the Navy will not
commence bomb deployment or mine laying.
[cir] During approach of the target or intended minefield
location, the Navy will observe for marine mammals; if resource
is observed, the Navy will cease bomb deployment or mine
laying.
[cir] To allow a sighted marine mammal to leave the mitigation
zone, the Navy will not recommence bomb deployment or mine
laying until one of the recommencement conditions has been met:
(1) The animal is observed exiting the mitigation zone; (2) the
animal is thought to have exited the mitigation zone based on a
determination of its course, speed, and movement relative to
the intended target or minefield location; (3) the mitigation
zone has been clear from any additional sightings for 10 min.;
or (4) for activities using mobile targets, the intended target
has transited a distance equal to double that of the mitigation
zone size beyond the location of the last sighting.
------------------------------------------------------------------------

[[Page 11056]]

Mitigation Areas

In addition to procedural mitigation, the Navy will implement
mitigation measures within specific areas and/or times to avoid or
minimize potential impacts on marine mammals (see Figures 11.2-1
through 11.2-3 of the Navy's rulemaking and LOA application). The Navy
reanalyzed existing mitigation areas and considered new habitat areas
suggested by the public, NMFS, and other non-Navy organizations,
including NARW critical habitat, important habitat for sperm whales,
biologically important areas (BIAs), and National Marine Sanctuaries.
The Navy worked collaboratively with NMFS to develop mitigation areas
using inputs from the Navy's operational community, the best available
science discussed in Chapter 3 of the AFTT DEIS/OEIS (Affected
Environment and Environmental Consequences), published literature,
predicted activity impact footprints, and marine species monitoring and
density data. The Navy will continue to work with NMFS to finalize its
mitigation areas through the development of the rule. The Navy
considered a mitigation area to be effective and thereby warranted, if
it met all three of the following criteria and also was determined to
be practicable:
[ssquf] The mitigation area is a key area of biological or
ecological importance or contains cultural resources: The best
available science suggests that the mitigation area contains submerged
cultural resources (e.g., shipwrecks) or is important to one or more
species or resources for a biologically important life process (i.e.,
foraging, migration, reproduction) or ecological function (e.g.,
shallow-water coral reefs that provide critical ecosystem functions);
[ssquf] The mitigation would result in an avoidance or reduction of
impacts: Implementing the mitigation would likely result in an
avoidance or reduction of impacts on (1) species, stocks, or
populations of marine mammals based on data regarding seasonality,
density, and animal behavior; or (2) other biological or cultural
resources based on their distribution and physical properties; and
[ssquf] The mitigation area would result in a net benefit to the
biological or cultural resource: Implementing the mitigation would not
simply shift from one area or species to another, resulting in a
similar or worse level of effect.
Information on the mitigation measures that the Navy will implement
within mitigation areas is provided in Table 63 through Table 65. The
mitigation applies year-round unless specified otherwise in the tables.

Mitigation Areas Off Northeastern United States

Mitigation areas for of the Northeastern United States are
described in Table 63 below and also depicted in Figure 11.2-1 in the
Navy's rulemaking and LOA application.

Table 63--Mitigation Areas off the Northeastern United States
------------------------------------------------------------------------
Mitigation area description
-------------------------------------------------------------------------
Stressor or Activity:
Sonar.
Explosives.
Physical disturbance and strikes.
Mitigation Area Requirements:
Northeast North Atlantic Right Whale Mitigation Areas (year-
round):
[cir] The Navy will minimize the use of low-frequency active
sonar, mid-frequency active sonar, and high-frequency active
sonar to the maximum extent practicable.
[cir] The Navy will not use Improved Extended Echo Ranging
sonobuoys (within 3 nmi of the mitigation area), explosive and
non-explosive bombs, in-water detonations, and explosive
torpedoes.
[cir] For activities using non-explosive torpedoes, the Navy
will conduct activities during daylight hours in Beaufort sea
state 3 or less. The Navy will use three Lookouts (one
positioned on a vessel and two in an aircraft during dedicated
aerial surveys) to observe the vicinity of the activity. An
additional Lookout will be positioned on the submarine, when
surfaced. Immediately prior to the start of the activity,
Lookouts will observe for floating vegetation and marine
mammals; if the resource is observed, the activity will not
commence. During the activity, Lookouts will observe for marine
mammals; if observed, the activity will cease. To allow a
sighted marine mammal to leave the area, the Navy will not
recommence the activity until one of the recommencement
conditions has been met: (1) The animal is observed exiting the
vicinity of the activity; (2) the animal is thought to have
exited the vicinity of the activity based on a determination of
its course, speed, and movement relative to the activity
location; or (3) the area has been clear from any additional
sightings for 30 min. During transits and normal firing, ships
will maintain a speed of no more than 10 knots. During
submarine target firing, ships will maintain speeds of no more
than 18 knots. During vessel target firing, ship speeds may
exceed 18 knots for brief periods of time (e.g., 10-15 min.).
[cir] For all activities, before vessel transits, the Navy will
conduct a web query or email inquiry to the National
Oceanographic and Atmospheric Administration Northeast
Fisheries Science Center's North Atlantic Right Whale Sighting
Advisory System to obtain the latest North Atlantic right whale
sighting information. Vessels will use the obtained sightings
information to reduce potential interactions with North
Atlantic right whales during transits. Vessels will implement
speed reductions after they observe a North Atlantic right
whale, if they are within 5 nmi of a sighting reported to the
North Atlantic Right Whale Sighting Advisory System within the
past week, and when operating at night or during periods of
reduced visibility.
Gulf of Maine Planning Awareness Mitigation Area (year-
round):
[cir] The Navy will not plan major training exercises (Composite
Training Unit Exercises or Fleet Exercises/Sustainment
Exercises), and will not conduct more than 200 hours of hull-
mounted mid-frequency active sonar per year.
[cir] If the Navy needs to conduct major training exercises or
more than 200 hours of hull-mounted mid-frequency active sonar
per year for national security, it will provide NMFS with
advance notification and include the information in any
associated training or testing activities or monitoring
reports.
Northeast Planning Awareness Mitigation Areas (year-round):
[cir] The Navy will avoid planning major training exercises
(Composite Training Unit Exercises or Fleet Exercises/
Sustainment Exercises) to the maximum extent practicable.
[cir] The Navy will not conduct more than four major training
exercises per year (all or a portion of the exercise).
[cir] If the Navy needs to conduct additional major training
exercises for national security, it will provide NMFS with
advance notification and include the information in any
associated training activity or monitoring reports.
------------------------------------------------------------------------

[[Page 11057]]

Mitigation Areas off the Mid-Atlantic and Southeastern United States

Mitigation areas off the Mid-Atlantic and Southeastern United
States are described in Table 64 below and also depicted in Figure
11.2-2 in the Navy's rulemaking and LOA application.

Table 64--Mitigation Areas off the Mid-Atlantic and Southeastern United
States
------------------------------------------------------------------------
Mitigation area description
-------------------------------------------------------------------------
Stressor or Activity:
Sonar.
Explosives.
Physical disturbance and strikes.
Mitigation Area Requirements:
Southeast North Atlantic Right Whale Mitigation Area
(November 15 through April 15):
[cir] The Navy will not conduct: (1) Low-frequency active sonar
(except as noted below), (2) mid-frequency active sonar (except
as noted below), (3) high-frequency active sonar, (4) missile
and rocket activities (explosive and non-explosive), (5) small-
, medium-, and large-caliber gunnery activities, (6) Improved
Extended Echo Ranging sonobuoy activities, (7) explosive and
non-explosive bombing activities, (8) in-water detonations, and
(9) explosive torpedo activities.
[cir] To the maximum extent practicable, the Navy will minimize
the use of: (1) Helicopter dipping sonar, (2) low-frequency
active sonar and hull-mounted mid-frequency active sonar used
for navigation training, and (3) low-frequency active sonar and
hull-mounted mid-frequency active sonar used for object
detection exercises.
[cir] Before transiting or conducting training or testing
activities, the Navy will initiate communication with the Fleet
Area Control and Surveillance Facility, Jacksonville to obtain
Early Warning System North Atlantic right whale sightings data.
The Fleet Area Control and Surveillance Facility, Jacksonville
will advise vessels of all reported whale sightings in the
vicinity to help vessels and aircraft reduce potential
interactions with North Atlantic right whales. Commander,
Submarine Force, Atlantic will coordinate any submarine
operations that may require approval from the Fleet Area
Control and Surveillance Facility, Jacksonville. Vessels will
use the obtained sightings information to reduce potential
interactions with North Atlantic right whales during transits.
Vessels will implement speed reductions after they observe a
North Atlantic right whale, if they are within 5 nmi of a
sighting reported within the past 12 hours, or when operating
at night or during periods of poor visibility. To the maximum
extent practicable, vessels will minimize north-south transits.
Mid-Atlantic Planning Awareness Mitigation Areas (year-
round):
[cir] The Navy will avoid planning major training exercises
(Composite Training Unit Exercises or Fleet Exercises/
Sustainment Exercises) to the maximum extent practicable.
[cir] The Navy will not conduct more than four major training
exercises per year (all or a portion of the exercise).
[cir] If the Navy needs to conduct additional major training
exercises for national security, it will provide NMFS with
advance notification and include the information in any
associated training activity or monitoring reports.
------------------------------------------------------------------------

Mitigation Areas in the Gulf of Mexico

Mitigation areas in the Gulf of Mexico are described in Table 65
below and also depicted in Figure 11.2-3 in the Navy's rulemaking and
LOA application.

Table 65--Mitigation Areas in the Gulf of Mexico
------------------------------------------------------------------------
Mitigation area description
-------------------------------------------------------------------------
Stressor or Activity:
Sonar.
Mitigation Area Requirements:
Gulf of Mexico Planning Awareness Mitigation Areas (year-
round):
[cir] The Navy will avoid planning major training exercises
(i.e., Composite Training Unit Exercises or Fleet Exercises/
Sustainment Exercises) involving the use of active sonar to the
maximum extent practicable.
[cir] The Navy will not conduct any major training exercises in
the Gulf of Mexico Planning Awareness Mitigation Areas under
the Proposed Activity.
[cir] If the Navy needs to conduct additional major training
exercises in these areas for national security, it will provide
NMFS with advance notification and include the information in
any associated training activity or monitoring reports.
------------------------------------------------------------------------

Summary of Mitigation

The Navy's mitigation measures are summarized in Tables 66 and 67.
Figure 11.3-1 in the Navy's rulemaking and LOA application depicts the
mitigation areas that the Navy developed for marine mammals in the AFTT
Study Area.

Summary of Procedural Mitigation

A summary of procedural mitigation is described in Table 66 below.

Table 66--Summary of Procedural Mitigation
------------------------------------------------------------------------
Summary of mitigation zone or
Stressor or activity other mitigation
------------------------------------------------------------------------
Environmental Awareness and Education.. Afloat Environmental Compliance
Training for applicable
personnel.
Active Sonar........................... Depending on sonar source:
1,000 yd power down, 500 yd
power down, and 200 yd shut
down; or 200 yd shut down.
Airguns................................ 150 yd.

[[Page 11058]]

Pile Driving........................... 100 yd.
Weapons Firing Noise................... 30[deg] on either side of the
firing line out to 70 yd.
Explosive Sonobuoys.................... 600 yd.
Explosive Torpedoes.................... 2,100 yd.
Explosive Medium-Caliber and Large- 1,000 yd. (large-caliber
Caliber Projectiles. projectiles), 600 yd. (medium-
caliber projectiles during
surface-to-surface
activities), or 200 yd.
(medium-caliber projectiles
during air-to-surface
activities).
Explosive Missiles and Rockets......... 900 yd. (0.6-20 lb net
explosive weight), or 2,000
yd. (21-500 lb net explosive
weight).
Explosive Bombs........................ 2,500 yd.
Sinking Exercises...................... 2.5 nmi.
Explosive Mine Countermeasure and 600 yd (0.1-5 lb net explosive
Neutralization Activities. weight), or 2,100 yd (6-650 lb
net explosive weight).
Mine Neutralization Activities 500 yd (0.1-20 lb net explosive
Involving Navy Divers. weight for positive control
charges), or 1,000 yd (21-60
lb net explosive weight for
positive control charges and
all charges using time-delay
fuses).
Maritime Security Operations--Anti- 200 yd.
Swimmer Grenades.
Line Charge Testing.................... 900 yd.
Ship Shock Trials...................... 3.5 nmi.
Vessel Movement........................ 500 yd (whales), or 200 yd
(other marine mammals).
Towed In-Water Devices................. 250 yd.
Small-, Medium-, and Large-Caliber Non- 200 yd.
Explosive Practice Munitions.
Non-Explosive Missiles and Rockets..... 900 yd.
Non-Explosive Bombs and Mine Shapes.... 1,000 yd.
------------------------------------------------------------------------
Notes: lb: pounds; nmi: nautical miles; yd: yards.

Summary of Mitigation Areas

A summary of mitigation areas is described in Table 67 below.
Mitigation areas for marine mammals in the AFTT Study Area are also
depicted in Figure 11.3-1 in the Navy's rulemaking and LOA application.

Table 67--Summary of Mitigation Areas for Marine Mammals
------------------------------------------------------------------------
Mitigation area Summary of mitigation requirements
------------------------------------------------------------------------
Mitigation Areas for Marine Mammals
------------------------------------------------------------------------
Northeast North Atlantic Right The Navy will minimize use
Whale Mitigation Area. of active sonar to the maximum
extent practicable.
The Navy will not use
explosives that detonate in the
water.
The Navy will conduct non-
explosive torpedo testing during
daylight hours in Beaufort sea
state 3 or less using three
Lookouts (one on a vessel, two in
an aircraft during dedicated aerial
surveys) and an additional Lookout
on the submarine when surfaced;
during transits, ships will
maintain a speed of no more than 10
knots; during firing, ships will
maintain a speed of no more than 18
knots except for brief periods of
time during vessel target firing.
Navy will obtain the latest
North Atlantic right whale
sightings data.
Vessels will implement
speed reductions after they observe
a North Atlantic right whale, if
they are within 5 nmi of a sighting
reported within the past week, and
when operating at night or during
periods of reduced visibility.
Gulf of Maine Planning Awareness The Navy will not plan
Mitigation Area. major training exercises.
The Navy will not conduct
more than 200 hours of hull-mounted
mid-frequency active sonar per
year.
Northeast Planning Awareness The Navy will avoid
Mitigation Areas, Mid-Atlantic planning major training exercises
Planning Awareness Mitigation to the maximum extent practicable.
Areas. The Navy will not conduct
more than four major training
exercises per year (all or a
portion of the exercise).
Southeast North Atlantic Right The Navy will not conduct
Whale Mitigation Area (November active sonar except as necessary
15 through April 15). for navigation and object detection
training, and dipping sonar.
The Navy will not expend
explosive or non-explosive
ordnance.
The Navy will obtain the
latest North Atlantic right whale
sightings data.
Vessels will implement
speed reductions after they observe
a North Atlantic right whale, if
they are within 5 nmi of a sighting
reported within the past 12 hours,
and when operating at night or
during periods of reduced
visibility.
To the maximum extent
practicable, vessels will minimize
north-south transits.
Gulf of Mexico Planning Awareness The Navy will avoid
Mitigation Areas. planning major training exercises
to the maximum extent practicable.
The Navy will not conduct
any major training exercises (all
or a portion of the exercise) in
each area under the Proposed
Activity.
------------------------------------------------------------------------
Notes: min.: minutes; nmi: nautical miles.

[[Page 11059]]

Mitigation Areas for Seafloor Resources

Mitigation areas for seafloor resources are described in Table 68
and Table 69 below. Because these measures, in particular, are not
related directly to protecting marine mammals and their habitat, they
are not a requirement of this MMPA rulemaking. However, they are part
of the Navy's Proposed Activity and are therefore included here for
informational purposes.

Table 68--Mitigation Areas for Seafloor Resources
------------------------------------------------------------------------
Mitigation area description
-------------------------------------------------------------------------
Stressor or Activity:
Explosives.
Physical disturbance and strikes.
Resource Protection Focus:
Shallow-water coral reefs.
Live hard bottom.
Artificial reefs.
Shipwrecks.
Mitigation Area Requirements (year-round):
Within the anchor swing circle of shallow-water coral
reefs, live hard bottom, artificial reefs, and shipwrecks:
[cir] The Navy will not conduct precision anchoring (except in
designated anchorages).
Within a 350-yd radius of live hard bottom, artificial
reefs, and shipwrecks:
[cir] The Navy will not conduct explosive mine countermeasure
and neutralization activities or explosive mine neutralization
activities involving Navy divers.
[cir] The Navy will not place mine shapes, anchors, or mooring
devices on the seafloor.
Within a 350-yd radius of shallow-water coral reefs:
[cir] The Navy will not conduct explosive or non-explosive small-
, medium-, and large-caliber gunnery activities using a surface
target; explosive or non-explosive missile and rocket
activities using a surface target; explosive or non-explosive
bombing and mine laying activities; explosive or non-explosive
mine countermeasure and neutralization activities; and
explosive or non-explosive mine neutralization activities
involving Navy divers.
[cir] The Navy will not place mine shapes, anchors, or mooring
devices on the seafloor.
Within the South Florida Ocean Measurement Facility Testing
Range:
[cir] The Navy will use real-time geographic information system
and global positioning system (along with remote sensing
verification) during deployment, installation, and recovery of
anchors and mine-like objects and during deployment of bottom-
crawling unmanned underwater vehicles in waters deeper than 10
ft to avoid shallow-water coral reefs and live hard bottom.
[cir] Vessels deploying anchors, mine-like objects, and bottom-
crawling unmanned underwater vehicles will aim to hold a
relatively fixed position over the intended mooring or
deployment location using a dynamic positioning navigation
system with global positioning system.
[cir] The Navy will minimize vessel movement and drift in
accordance with mooring installation and deployment plans, and
will conduct activities during sea and wind conditions that
allow vessels to maintain position and speed control during
deployment, installation, and recovery of anchors, mine-like
objects, and bottom-crawling unmanned underwater vehicles.
[cir] Vessels will operate within waters deep enough to avoid
bottom scouring or prop dredging, with at least a 1-ft
clearance between the deepest draft of the vessel (with the
motor down) and the seafloor at mean low water.
[cir] The Navy will not anchor vessels or spud over shallow-
water coral reefs and live hard bottom.
[cir] The Navy will use semi-permanent anchoring systems that
are assisted with riser buoys over soft bottom habitats to
avoid contact of mooring cables with shallow-water coral reefs
and live hard bottom.
------------------------------------------------------------------------

Table 69--Summary of Mitigation Areas for Seafloor Resources
------------------------------------------------------------------------
Mitigation area Summary of mitigation requirements
------------------------------------------------------------------------
Mitigation Areas for Seafloor Resources
------------------------------------------------------------------------
Shallow-water coral reefs......... The Navy will not conduct
precision anchoring (except in
designated anchorages), explosive
mine countermeasure and
neutralization activities,
explosive or non-explosive mine
neutralization activities involving
Navy divers, explosive or non-
explosive small-, medium-, and
large-caliber gunnery activities
using a surface target, explosive
or non-explosive missile and rocket
activities using a surface target,
or explosive or non-explosive
bombing or mine laying activities.
The Navy will not place
mine shapes, anchors, or mooring
devices on the seafloor.
Within the South Florida
Ocean Measurement Facility Testing
Range, the Navy will implement
additional measures, such as using
real-time positioning and remote
sensing information to avoid
shallow-water coral reefs during
deployment, installation, and
recovery of anchors and mine-like
objects, and during deployment of
bottom-crawling unmanned underwater
vehicles.
Live hard bottom.................. The Navy will not conduct
precision anchoring (except in
designated anchorages), explosive
mine countermeasure and
neutralization activities, or
explosive mine neutralization
activities involving Navy divers.
The Navy will not place
mine shapes, anchors, or mooring
devices on the seafloor.
Within the South Florida
Ocean Measurement Facility Testing
Range, the Navy will implement
additional measures, such as using
real-time positioning and remote
sensing information to avoid live
hard bottom during deployment,
installation, and recovery of
anchors and mine-like objects, and
during deployment of bottom-
crawling unmanned underwater
vehicles.
Artificial reefs, Shipwrecks...... The Navy will not conduct
precision anchoring (except in
designated anchorages), explosive
mine countermeasure and
neutralization activities, or
explosive mine neutralization
activities involving Navy divers.
The Navy will not place
mine shapes, anchors, or mooring
devices on the seafloor.
------------------------------------------------------------------------

[[Page 11060]]

Mitigation Conclusions
NMFS has carefully evaluated the Navy's proposed mitigation
measures--many of which were developed with NMFS' input during the
previous phases of Navy training and testing authorizations--and
considered a broad range of other measures (i.e., the measures
considered but eliminated in the Navy's EIS, which reflect many of the
comments that have arisen via NMFS or public input in past years) 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 measures for applicant
implementation, including consideration of personnel safety,
practicality of implementation, and impact on the effectiveness of the
military readiness activity.
Based on our evaluation of the Navy's proposed measures, as well as
other measures considered by NMFS, NMFS has preliminarily determined
that the Navy's proposed mitigation measures (especially when the
adaptive management component is taken into consideration (see Adaptive
Management, below)) are appropriate 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 these
activities and the proposed mitigation measures. While NMFS has
preliminarily determined 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.

Proposed Monitoring

Section 101(a)(5)(A) of the MMPA states that in order to authorize
incidental take 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 incidental take authorizations 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 marine species 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. This process includes conducting an annual adaptive
management review meeting, at which the Navy and NMFS jointly consider
the prior-year goals, monitoring results, and related scientific
advances to determine if monitoring plan modifications are warranted to
more effectively address program goals. Although the ICMP does not
specify actual monitoring field work or individual projects, it does
establish a matrix of goals and objectives that have been developed in
coordination with NMFS. As the ICMP is implemented through the
Strategic Planning Process, 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:
[ssquf] 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);
[ssquf] 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., sound, explosive detonation, or military expended materials),
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), 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);
[ssquf] 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);
[ssquf] 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);
[ssquf] An increase in our understanding of the effectiveness of
mitigation and monitoring measures;
[ssquf] A better understanding and record of the manner in which
the authorized entity complies with the incidental take regulations and
LOAs and ESA Incidental Take Statement;
[ssquf] An increase in the probability of detecting marine mammals
(through improved technology or methods), both specifically within the
mitigation zone (thus allowing for more effective implementation of the
mitigation) and in general, to better achieve the above goals; and
[ssquf] Ensuring that adverse impact of activities remains at the
least practicable level.

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 intermediate scientific objectives and a

[[Page 11061]]

conceptual framework incorporating a progression of knowledge, spanning
occurrence, exposure, response, and consequence. The Strategic Planning
Process for Marine Species Monitoring is used to set overarching
intermediate scientific objectives, develop individual monitoring
project concepts, identify potential species of interest at a regional
scale, evaluate, prioritize and select specific monitoring projects to
fund or continue supporting for a given fiscal year, execute and manage
selected monitoring projects, and report and evaluate progress and
results. This process addresses 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 and Current Monitoring in the AFTT Study Area

NMFS has received multiple years' worth of annual exercise and
monitoring reports addressing active sonar use and explosive
detonations within the AFTT Study Area and other Navy range complexes.
The data and information contained in these reports have been
considered in developing mitigation and monitoring measures for the
proposed training and testing activities within the AFTT Study Area.
The Navy's annual exercise and monitoring reports may be viewed at:
https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities and http://www.navymarinespeciesmonitoring.us.
The Navy's marine species monitoring program typically supports 10-
15 projects in the Atlantic at any given time with an annual budget of
approximately $3.5M. Current projects cover a range of species and
topics from collecting baseline data on occurrence and distribution, to
tracking whales and sea turtles, to conducting behavioral response
studies on beaked whales and pilot whales. The navy's marine species
monitoring web portal provides details on past and current monitoring
projects, including technical reports, publications, presentations, and
access to available data and can be found at: https://www.navymarinespeciesmonitoring.us/regions/atlantic/current-projects/.

Adaptive Management

The final regulations governing the take of marine mammals
incidental to Navy training and testing activities in the AFTT Study
Area would contain an adaptive management component. Our understanding
of the effects of Navy training and testing activities (e.g., acoustic
and explosive stressors) on marine mammals continues to evolve, which
makes the inclusion of an adaptive management component both valuable
and necessary within the context of five-year regulations for these.
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 to existing mitigation and
monitoring requirements 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 LOA. The
results from monitoring reports and other studies may be viewed at
https://www.navymarinespeciesmonitoring.us/.

Proposed Reporting

In order to issue incidental take authorization for an activity,
section 101(a)(5)(A) of the MMPA states that NMFS must set forth
``requirements pertaining to the monitoring and reporting of such
taking.'' Effective reporting is critical both to compliance as well as
ensuring that the most value is obtained from the required monitoring.
Some of the reporting requirements are still in development and the
final rulemaking may contain additional minor 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:

Notification of Injured, Live Stranded or Dead Marine Mammals

The Navy will abide by the Notification and Reporting Plan, which
sets out notification, reporting, and other requirements when injured,
live stranded, or dead marine mammals are detected. The Notification
and Reporting Plan is available for review at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.

Annual AFTT Monitoring Report

The Navy shall submit an annual report to NMFS of the AFTT
monitoring describing the implementation and results from the previous
calendar year. Data collection methods will be standardized across
range complexes and AFTT Study Area to allow for comparison in
different geographic locations. 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.
Such a report would describe progress of knowledge made with respect to
intermediate scientific objectives within the AFTT Study Area
associated with the Integrated Comprehensive Monitoring Program.
Similar study questions shall be treated together so that summaries can
be provided for each topic area. The report need not include analyses
and content that does not provide direct assessment of cumulative
progress on the monitoring plan study questions.

Annual AFTT Exercise Report

Each year, the Navy shall submit a preliminary report to NMFS
detailing the status of authorized sound sources within 21 days after
the anniversary of the date of issuance of the LOA. Each year, the Navy
shall submit a detailed report to NMFS within 3 months after the
anniversary of the date of issuance of the LOA. The annual report shall
contain information on Major Training

[[Page 11062]]

Exercises (MTEs) and Testing Exercises, Sinking Exercise (SINKEX)
events, and a summary of all sound sources used (total 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; and
total annual expended/detonated rounds (missiles, bombs, sonobuoys,
etc.) for each explosive bin). The analysis in the detailed report will
be based on the accumulation of data from the current year's report and
data presented in the previous report. Information included in the
classified annual reports may be used to inform future adaptive
management of activities within the AFTT Study Area.

Major Training Exercises Notification

The Navy shall submit an electronic report to NMFS within fifteen
calendar days after the completion of any major training exercise
indicating: Location of the exercise; beginning and end dates of the
exercise; and type of exercise.

Five-Year Close-Out Exercise Report

This report will be included as part of the 2023 annual exercise
report. This report will provide the annual totals for each sound
source bin with a comparison to the annual allowance and the five-year
total for each sound source bin with a comparison to the five-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 EIS and final rule determinations. The report
will be submitted to NMFS three months after the expiration of the
rule. NMFS will provide comments to the Navy on the draft close-out
report, if any, within three months of receipt. The report will be
considered final after the Navy has addressed NMFS' comments, or three
months after the submittal of the draft if NMFS does not provide
comments.

Preliminary Analysis and Negligible Impact Determination

Negligible Impact Analysis

Introduction
NMFS has defined negligible impact 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'' (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. In addition to
considering estimates of the number of marine mammals that might be
``taken'' through mortality, serious injury, and Level A or Level B
harassment (as presented in Tables 39-41), NMFS considers other
factors, such as the likely nature of any responses (e.g., intensity,
duration), the context of any responses (e.g., critical reproductive
time or location, migration), as well as effects on habitat, and the
likely effectiveness of the mitigation. We also assess the number,
intensity, and context of estimated takes by evaluating this
information relative to population status. Consistent with the 1989
preamble for NMFS's implementing regulations (54 FR 40338; September
29, 1989), the impacts from other past and ongoing anthropogenic
activities are incorporated into this analysis via their impacts on the
environmental baseline (e.g., as reflected in the regulatory status of
the species, population size and growth rate where known, other ongoing
sources of human-caused mortality, ambient noise levels, and specific
consideration of take by Level A harassment or serious injury or
mortality (hereafter referred to as M/SI) previously authorized for
other NMFS activities).
In the Estimated Take section, we identified the subset of
potential effects that would be expected to rise to the level of takes,
and then identified the number of each of those takes that we believe
could occur (mortality) or are likely to occur (harassment) based on
the methods described. Not all takes are created equal, in other words,
the impact that any given take will have is dependent on many case-
specific factors that need to be considered in the negligible impact
analysis (e.g., the context of behavioral exposures such as duration or
intensity of an disturbance, the health of impacted animals, the status
of a species that incurs fitness-level impacts to individuals, etc.).
Here, we evaluate the likely impacts of the enumerated harassment takes
that are proposed for authorization or anticipated to occur in this
rule, in the context of the specific circumstances surrounding these
predicted take. We also include a specific assessment of serious injury
or mortality takes that could occur, as well as consideration of the
traits and statuses of the affected species and stocks. Last, we pull
all of this information, as well as other more taxa-specific
information, together into group-specific discussions that support our
negligible impact conclusions for each stock.

Harassment

The Navy's proposed activity reflects representative levels/ranges
of training and testing activities, accounting for the natural
fluctuation in training, testing, and deployment schedules. This
approach is representative of how Navy's activities are conducted over
any given year over any given five-year period. Specifically, to
calculate take, the Navy provided a range of levels for each activity/
source type for a year--they used the maximum annual level to calculate
annual takes, and they used the sum of three nominal years (average
level) and two maximum years to calculate five-year takes for each
source type. The Proposed Activity contains a more realistic annual
representation of activities, but includes years of a higher maximum
amount of testing to account for these fluctuations. There may be some
flexibility in that the exact number of hours, items, or detonations
that may vary from year to year, but take totals would not exceed the
five-year totals indicated in Tables 39 through 41. We base our
analysis and negligible impact determination (NID) on the maximum
number of takes that could occur or are likely to occur, although, as
stated before, the number of takes are only a part of the analysis,
which includes extensive qualitative consideration of other contextual
factors that influence the degree of impact of the takes on the
affected individuals. To avoid repetition, we provide some general
analysis immediately below that applies to all the species listed in
Tables 39 through 41, given that some of the anticipated effects of the
Navy's training and testing activities on marine mammals are expected
to be relatively similar in nature. However, below that, we break our
analysis into species (and/or stock), or groups of species (and the
associated stocks) where relevant similarities exist, to provide more
specific information related to the anticipated effects on individuals
or where there is information about the status or structure of any
species that would lead to a differing assessment of the effects on the
species or stock.
The Navy's harassment take request is based on its model and post-
model analysis, which NMFS believes appropriately predicts that amount
of harassment that is likely to occur. In the discussions below, the
``acoustic analysis'' refers to the Navy's modeling results and post-
model analysis. The model calculates sound energy propagation from
sonar, other active acoustic sources, and explosives during

[[Page 11063]]

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 energy received by a marine
mammal exceeds the thresholds for effects. Assumptions in the Navy
model intentionally err on the side of overestimation when there are
unknowns. Naval activities are modeled as though they would occur
regardless of proximity to marine mammals, meaning that no mitigation
is considered (e.g., no power down or shut down) and without any
avoidance of the activity by the animal. The final step of the
quantitative analysis of acoustic effects, which occurs after the
modeling, is to consider the implementation of mitigation and the
possibility that marine mammals would avoid continued or repeated sound
exposures. NMFS provided input to, and concurred with, the Navy on this
process and the Navy's analysis, which is described in detail in
Section 6 of the Navy's rulemaking and LOA application (https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities) was used to quantify
harassment takes for this rule.
Generally speaking, 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 for behavioral
effects throughout species, individuals, or circumstances) and less
severe effects from takes resulting from exposure to lower received
levels. However, there is also growing evidence of the importance of
distance in predicting marine mammal behavioral response to sound--
i.e., sounds of a similar level emanating from a more distant source
have been shown to be less likely to evoke a response of equal
magnitude (DeRuiter 2012). The estimated number of Level A and 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 A and Level B harassment threshold)
that are anticipated to occur over the five-year period. These
instances may represent either a very brief exposure (seconds) or, in
some cases, longer durations of exposure within a day. Some individuals
may experience multiple instances of take over the course of the year,
while some members of a species or stock may not experience take at
all. 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 A and 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 individuals.
Some of the lower level physiological stress responses (e.g.,
orientation or startle response, change in respiration, change in heart
rate) 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. Level B takes, then, may have a stress-related physiological
component as well; however, we would not expect the Navy's generally
short-term, intermittent, and (in the case of sonar) transitory
activities to create conditions of long-term, continuous noise leading
to long-term physiological stress responses in marine mammals.
The estimates calculated using the behavioral response function do
not differentiate between the different types of behavioral responses
that rise to the level of Level B harassments. As described in the
Navy's application, the Navy identified (with NMFS' input) the types of
behaviors that would be considered a take (moderate behavioral
responses as characterized in Southall et al., 2007 (e.g., altered
migration paths or dive profiles, interrupted nursing breeding or
feeding, or avoidance) that also would be expected to continue for the
duration of an exposure) and then compiled the available data
indicating at what received levels and distances those responses have
occurred, and used the indicated literature to build biphasic
behavioral response curves that are used to predict how many instances
of behavioral take occur in a day. 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 activity-specific, environmental, and species-
specific information to determine the likely nature of the modeled
behavioral responses and the potential fitness consequences for
affected individuals.
For sonar (LFAS/MFAS/HFAS) used in the AFTT Study Area, the Navy
provided information estimating the percentage of animals that may
exhibit a significant behavior response under each behavioral response
function that would occur within 6-dB increments (percentages discussed
below in the Group and Species-Specific Analysis section). 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 lead to
adverse effects on the reproductive success or survivorship of the
animal. The majority of Level B takes are expected to be in the form of
milder responses (i.e., lower-level exposures that still rise to the
level of take, but would likely be less severe in the range of
responses that qualify as take) of a generally shorter duration. We
anticipate more severe effects from takes when animals are exposed to
higher received levels. These discussions are presented within each
species group below in the Group and Species-Specific Analysis section.
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 smaller percentage of the anticipated Level B harassment (see the
Group and Species-Specific Analysis section below for more detailed
information) from Navy activities might necessarily be expected to
potentially result in more severe responses. To fully understand the
likely impacts of the predicted/authorized take on an individual (i.e.,
what is the likelihood or degree of fitness impacts), one must look
closely at the available contextual information, such as the duration
of likely exposures and the likely severity of the exposures (e.g.,
will they occur from high level hull-mounted sonars or smaller less
impactful sources). Moore and Barlow (2013) emphasizes the importance
of context (e.g., behavioral state of the animals, distance from the
sound source, etc.) in evaluating behavioral responses of marine
mammals to acoustic sources.

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

[[Page 11064]]

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 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
such as ASW activities, typically include vessels that are continuously
moving at speeds typically 10-15 knots, or higher, and likely cover
large areas that are relatively far from shore (typically more than 12
nmi from shore) and in waters greater than 600 ft deep, 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. Further, 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 unlikely for the majority of
takes. However, it is also worth noting that the Navy conducts many
different types of noise-producing activities over the course of the
year and it is likely that some marine mammals will be exposed to more
than one and taken on multiple days, even if they are not sequential.
Durations of Navy activities utilizing tactical sonar sources and
explosives vary and are fully described in Appendix A of the AFTT DEIS/
OEIS. Sonar used during ASW would impart the greatest amount of
acoustic energy of any category of sonar and other transducers analyzed
in the Navy's rulemaking and LOA request and included hull-mounted,
towed, line array, sonobuoy, helicopter dipping, and torpedo sonars.
Most ASW sonars are MFAS (1-10 kHz); however, some sources may use
higher or lower frequencies. Duty cycles can vary widely, from rarely
used to continuously active. ASW training activities using hull mounted
sonar proposed for the AFTT Study Area generally last for only a few
hours. Some ASW exercises can generally last for 2-10 days, or as much
as 21 days for an MTE -Large Integrated ASW (see Table 4). For these
multi-day exercises there will be extended intervals of non-activity in
between active sonar periods. Because of the need to train in a large
variety of situations, the Navy does not typically conduct successive
ASW exercises in the same locations. Given the average length of ASW
exercises (times of sonar use) and typical vessel speed, combined with
the fact that the majority of the cetaceans in the would not likely
remain in proximity to the sound source, it is unlikely that an animal
would be exposed to LFAS/MFAS/HFAS at levels or durations likely to
result in a substantive response that would then be carried on for more
than one day or on successive days.
Most planned explosive events are scheduled to occur over a short
duration (1-8 hours); however, the explosive component of the activity
only lasts for minutes (see Tables 4 through 7). 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. Although SINKEXs may last for up to 48 hrs, (4-8 hours, possibly
1-2 days), they are almost always completed in a single day and only
one event is planned annually for the AFTT training activities. They
are stationary and conducted in deep, open water (where fewer marine
mammals would typically be expected to be randomly encountered), and
they have rigorous monitoring (i.e., during the activity, conduct
passive acoustic monitoring and visually observe for marine mammals 90
min prior to the first firing, during the event, and 2 hrs after
sinking the vessel) and shutdown procedures all of which make it
unlikely that individuals would be exposed to the exercise for extended
periods or on consecutive days.
Last, as described previously, Navy modeling uses the best
available science to predict the instances of exposure above certain
acoustic thresholds, which are equated, as appropriate, to harassment
takes (and further corrected to account for mitigation and avoidance).
As further noted, for active acoustics, it is more challenging to parse
out the number of individuals taken from this larger number of
instances. One method that NMFS can use to help better understand the
overall scope of the impacts is to compare these total instances of
take against the abundance of that stock. For example, if there are 100
takes in a population of 100, one can assume either that every
individual was exposed above acoustic thresholds in no more than one
day, or that some smaller number were exposed in one day but a few of
those individuals were exposed in multiple days. At a minimum, it
provides a relative picture of the scale of impacts to each stock. When
calculating the proportion of a population affected by takes (e.g., the
number of takes divided by population abundance), it is important to
choose an appropriate population estimate to make the comparison. While
the SARs provide the official population estimate for a given species
or stock in a given year (and are typically based solely on the most
recent survey data), the SARs are often not used to estimate takes,
instead modeled density information is used. If takes are calculated
from another dataset (for example a broader sample of survey data) and
compared to the population estimate from the SARs, it may distort the
percent of the population affected because of different population
baselines.
The estimates found in NMFS's SARs remain the official estimates of
stock abundance where they are current. These estimates are typically
generated from the most recent shipboard and/or aerial surveys
conducted. Studies based on abundance and distribution surveys
restricted to U.S. waters are unable to detect temporal shifts in
distribution beyond U.S. waters that might account for any changes in
abundance within U.S. waters. NMFS's SAR estimates also may not
incorporate correction for detection bias. In these cases, they should
generally be considered as underestimates, especially for cryptic or
long-diving species (e.g., beaked whales, Kogia spp., sperm whales). In
some cases, NMFS's abundance estimates show substantial year-to-year
variability. For the reasons stated above, we used the Navy's abundance
predictions to make relative comparisons between the exposures
predicted by the outputs of the model and the overall abundance
predicted by the model. However, our use of the Navy's abundance
estimates is not intended to make any statement about NMFS's SAR
abundance estimates.
The Navy uses, and NMFS supports the use of spatially and
temporally explicit density models that vary in space and time to
estimate their potential impacts to species. See the U.S. Navy Marine
Species Density Database Phase III for the Atlantic Fleet Training and
Testing Area Technical Report to learn more on how the Navy selects
density information and the models selected for individual species.
These models may better characterize how Navy impacts can vary in space
and time but often predict different population abundances than the
SARs.
Models may predict different population abundances for many

[[Page 11065]]

reasons. The models may be based on different data sets or different
temporal predictions may be made. The SARs are often based on single
years of NMFS surveys whereas the models used by the Navy generally
include multiple years of survey data from NMFS, the Navy, and other
sources. To present a single, best estimate, the SARs often use a
single season survey where they have the best spatial coverage
(generally summer). Navy models often use predictions for multiple
seasons, where appropriate for the species, even when survey coverage
in non-summer seasons is limited, to characterize impacts over multiple
seasons as Navy activities may occur in any season. Predictions may be
made for different spatial extents. Many different, but equally valid,
habitat and density modeling techniques exist and these can also be the
cause of differences in population predictions. Differences in
population estimates may be caused by a combination of these factors.
Even similar estimates should be interpreted with caution and
differences in models be fully understood before drawing conclusions.
The Navy Study Area covers a broad area in the western North
Atlantic Ocean and the Navy has tried to find density estimates for
this entire area, where appropriate given species distributions.
However, only a small number of Navy training and testing activities
occur outside of the U.S. EEZ. As such, NMFS believes that the average
population predicted by Navy models across seasons in the U.S. EEZ is
the best baseline to use when analyzing takes as a proportion of
population. This is a close approximation of the actual population used
in Navy take analysis as occasionally sound can propagate outside of
the U.S. EEZ and a small number of exercises do occur in international
waters. This approximation will be less accurate for species with major
changes in density close to the U.S. EEZ or far offshore. In all cases
it is important to understand the differences between Navy models and
the SARs on a species by species case. Models of individual species or
stocks were not available for all species and takes had to be
proportioned to the species or stock level from takes predicted on
models at higher taxonomic levels. See the various Navy technical
reports mentioned previously in this rule that detail take estimation
and density model selection for details.

TTS

NMFS and the Navy have estimated that some individuals of some
species of marine mammals may sustain some level of TTS from active
sonar. 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. Tables
72-77 indicate the amounts of TTS that may be incurred by different
stocks from exposure to active sonar and explosives. No TTS is
estimated from airguns or piledriving activities. 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 Navy's MF sources the 1-10 kHz frequency band, which
suggests that if TTS were to be 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 10 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.
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 proposed rule. 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 (see Threshold Shift
section), 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, since any hull-mounted sonar such as the SQS-53
(MFAS), emits a ping typically every 50 seconds, incurring those levels
of TTS is highly unlikely.
3. Duration of TTS (recovery time)--In the TTS laboratory studies
(see Threshold Shift) section), 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 LFAS/MFAS/HFAS training and testing exercises in the AFTT Study
Area, it is unlikely that marine mammals would ever sustain a TTS from
MFAS that alters their sensitivity by more than 20 dB for more than a
few hours (and any incident of TTS would likely be far less severe due
to the short duration of the majority of the events 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 typically pings every
50 seconds for hull-mounted sources. Hull-mounted anti-submarine sonars
can also be used in an object detection mode known as ``Kingfisher''
mode (e.g., used on vessels when transiting to and from port), pulse

[[Page 11066]]

length is shorter, but pings are much closer together in both time and
space, since the vessel goes slower when operating in this mode. For
the majority of sources, the pulse length is 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.
Most ASW sonars and countermeasures use MF ranges and a few use LF
and HF ranges. Most of these sonar signals are limited in the temporal,
frequency, and spatial domains. The duration of most individual sounds
is short, lasting up to a few seconds each. Some systems operate with
higher duty cycles or nearly continuously, but typically use lower
power. Nevertheless, masking may be more prevalent at closer ranges to
these high-duty cycle and continuous active sonar systems. Most ASW
activities are geographically dispersed and last for only a few hours,
often with intermittent sonar use even within this period. Most ASW
sonars also have a narrow frequency band (typically less than one-third
octave). These factors reduce the likelihood of sources causing
significant masking in mysticetes. HF sonars are typically used for
mine hunting, navigation, and object detection, HF (greater than 10
kHz) sonars fall outside of the best hearing and vocalization ranges of
mysticetes). Furthermore, HF (above 10 kHz) attenuate more rapidly in
the water due to absorption than do lower frequency signals, thus
producing only a small zone of potential masking. Masking in mysticetes
due to exposure to high-frequency sonar is unlikely. Masking effects
from LFAS/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 resemble the characteristics of
any marine mammal's vocalizations. Masking could occur in mysticetes
due to the overlap between their low-frequency vocalizations and the
dominant frequencies of airgun pulses, however, masking in odontocetes
or pinnipeds is less likely unless the airgun activity is in close
range when the pulses are more broadband. Masking is more likely to
occur in the presence of broadband, relatively continuous noise sources
such as during vibratory pile driving and from vessels. The other
sources used in Navy training and testing, many of either higher
frequencies (meaning that the sounds generated attenuate even closer to
the source) or lower amounts of operation, are similarly not expected
to result in masking.
PTS From Sonar and Explosives and Tissue Damage From Explosives
Tables 72-77 indicates the number of individuals of each of species
and stock for which Level A harassment in the form of PTS resulting
from exposure to active sonar and/or explosives estimated to occur.
Tables 72-77 also indicate the number of individuals of each of species
and stock for which Level A harassment in the form of tissue damage
resulting from exposure to explosive detonations is estimated to occur.
The number of individuals to potentially incur PTS annually (from sonar
and explosives) for the predicted species ranges from 0 to 471 (471 for
harbor porpoise), but is more typically a few up to 33 (with the
exception of a few species). The number of individuals to potentially
incur tissue damage from explosives for the predicted species ranges
from 0 to 36 (36 for short-beaked common dolphin), but is typically
zero in most cases. Overall the Navy's model estimated that 8
delphinidae annually would be exposed to explosives during training and
testing at levels that could result in non-auditory injury. The Navy's
model estimated that 1 sperm whale and 94 delphinidae annually could
experience non-auditory injury. Overall, takes from Level A harassment
(PTS and Tissue Damage) account for less than one percent of all total
takes.
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-emitting vessel at a close distance, NMFS
believes that the mitigation measures (i.e., shutdown/powerdown zones
for active sonar) would typically ensure that animals would not be
exposed to injurious levels of sound, however, here we analyze the
impacts of those potential takes in case they should occur. As
discussed previously, the Navy utilizes both aerial (when available)
and passive acoustic monitoring (during ASW exercises--passive acoustic
detections are used as a cue for Lookouts' visual observations when
passive acoustic assets are already participating in an activity) in
addition to lookouts 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
(nominally 10-15 knots) would make it very difficult for the animal to
remain in range long enough to accumulate enough energy to result in
more than a mild case of PTS. As mentioned previously and in relation
to TTS, the likely consequences to the health of an individual that
incurs PTS can range from mild to more serious dependent upon the
degree of PTS and the frequency band it is in, and many animals are
able to compensate for the shift, although it may include energetic
costs. We also assume that the acoustic exposures sufficient to trigger
onset PTS (or TTS) would be accompanied by physiological stress
responses, although the sound characteristics that correlate with
specific stress responses in marine mammals are poorly understood. As
discussed above for Behavioral Harassment, we would not expect the
Navy's generally short-term, intermittent, and (in the case of sonar)
transitory activities to create conditions of long-term, continuous
noise leading to long-term physiological stress responses in marine
mammals.
For explosive activities, the Navy implements mitigation measures
(described in Proposed Mitigation Measures) during explosive
activities, including delaying detonations when a marine mammal is
observed in the mitigation zone. Observing for marine mammals during
the explosive activities will include aerial and passive acoustic
detection methods (when they are available and part of the activity)
before the activity begins, in order to cover the mitigation zones that
can range from 200 yds (183 m) to 2,500 yds (2,286 m) depending on the
source (e.g., explosive sonobuoy, explosive torpedo, explosive bombs)
and 2.5 nmi for sinking exercise (see Tables 47-56).
Observing for marine mammals during ship shock (which includes
lookouts in aircraft or on multiple vessels), begins 5 hrs before the
detonation and extends 3.5 nmi from the ship's hull (see Table 57).
Nearly all

[[Page 11067]]

explosive events will occur during daylight hours to improve the
sightability of marine mammals improving mitigation effectiveness. The
proposed mitigation is expected to reduce the likelihood that all of
the proposed takes will occur, however, we analyze the type and amount
of Level A take indicated in Tables 39 through 41. Generally speaking,
the number and degree of potential injury are low.

Serious Injury and Mortality

NMFS proposes to authorize a very small number of serious injuries
or mortalities that could occur in the event of a ship strike or as a
result of marine mammal exposure to explosive detonations (ship shock
trials). We note here that the takes from potential ship strikes or
explosive exposures enumerated below could result in non-serious
injury, but their worse potential outcome (mortality) is analyzed for
the purposes of the negligible impact determination.
In addition, we discuss here the connection between the mechanisms
for authorizing incidental take under section 101(a)(5) for activities,
such as Navy's testing and training in the AFTT Study Area, and for
authorizing incidental take from commercial fisheries. In 1988,
Congress amended the MMPA's provisions for addressing incidental take
of marine mammals in commercial fishing operations. Congress directed
NMFS to develop and recommend a new long-term regime to govern such
incidental taking (see MMC, 1994). The need to develop a system suited
to the unique circumstances of commercial fishing operations led NMFS
to suggest a new conceptual means and associated regulatory framework.
That concept, Potential Biological Removal (PBR), and a system for
developing plans containing regulatory and voluntary measures to reduce
incidental take for fisheries that exceed PBR were incorporated as
sections 117 and 118 in the 1994 amendments to the MMPA.
PBR is defined in the MMPA (16 U.S.C. 1362(20)) as ``the maximum
number of animals, not including natural mortalities, that may be
removed from a marine mammal stock while allowing that stock to reach
or maintain its optimum sustainable population,'' and is a measure that
can help evaluate the effects of M/SI on a marine mammal species or
stock. OSP is defined by the MMPA (16 U.S.C. 1362(9)) as ``the number
of animals which will result in the maximum productivity of the
population or the species, keeping in mind the carrying capacity of the
habitat and the health of the ecosystem of which they form a
constituent element.'' A primary goal of the MMPA is to ensure that
each species or stock of marine mammal is maintained at or returned to
its OSP.
PBR values are calculated by NMFS as the level of annual removal
from a stock that will allow that stock to equilibrate within OSP at
least 95 percent of the time, and is the product of factors relating to
the minimum population estimate of the stock (Nmin); the
productivity rate of the stock at a small population size; and a
recovery factor. Determination of appropriate values for these three
elements incorporates significant precaution, such that application of
the parameter to the management of marine mammal stocks may be
reasonably certain to achieve the goals of the MMPA. For example,
calculation of Nmin incorporates the precision and
variability associated with abundance information and is intended to
provide reasonable assurance that the stock size is equal to or greater
than the estimate (Barlow et al., 1995). In general, the three factors
are developed on a stock-specific basis in consideration of one another
in order to produce conservative PBR values that appropriately account
for both imprecision that may be estimated as well as potential bias
stemming from lack of knowledge (Wade, 1998).
PBR can be used as a consideration of the effects of M/SI on a
marine mammal stock but was applied specifically to work within the
management framework for commercial fishing incidental take. PBR cannot
be applied appropriately outside of the section 118 regulatory
framework for which it was designed to inform without consideration of
how it applies in 118 and how other statutory management frameworks
differ. PBR was not designed as an absolute threshold limiting
commercial fisheries, but rather as a means to evaluate the relative
impacts of those activities on marine mammal stocks. Even where
commercial fishing is causing M/SI at levels that exceed PBR, the
fishery is not suspended. When M/SI exceeds PBR, NMFS may develop a
take reduction plan, usually with the assistance of a take reduction
team. The take reduction plan will include measures to reduce and/or
minimize the taking of marine mammals by commercial fisheries to a
level below the stock's PBR. That is, where the total annual human-
caused M/SI exceeds PBR, NMFS is not required to halt fishing
activities contributing to total M/SI but rather utilizes the take
reduction process to further mitigate the effects of fishery activities
via additional bycatch reduction measures. PBR is not used to grant or
deny authorization of commercial fisheries that may incidentally take
marine mammals.
Similarly, to the extent consideration of PBR may be relevant to
considering the impacts of incidental take from activities other than
commercial fisheries, using it as the sole reason to deny incidental
take authorization for those activities would be inconsistent with
Congress's intent under section 101(a)(5) and the use of PBR under
section 118. The standard for authorizing incidental take under section
101(a)(5) continues to be, among other things, whether the total taking
will have a negligible impact on the species or stock. When Congress
amended the MMPA in 1994 to add section 118 for commercial fishing, it
did not alter the standards for authorizing non-commercial fishing
incidental take under section 101(a)(5), acknowledging that negligible
impact under section 101(a)(5) is a separate standard from PBR under
section 118. In fact, in 1994 Congress also amended section
101(a)(5)(E) (a separate provision governing commercial fishing
incidental take for species listed under the Endangered Species Act) to
add compliance with the new section 118 but kept the requirement for a
negligible impact finding, showing that the determination of negligible
impact and application of PBR may share certain features but are
different.
Since the introduction of PBR, NMFS has used the concept almost
entirely within the context of implementing sections 117 and 118 and
other commercial fisheries management-related provisions of the MMPA.
The MMPA requires that PBR be estimated in stock assessment reports and
that it be used in applications related to the management of take
incidental to commercial fisheries (i.e., the take reduction planning
process described in section 118 of the MMPA and the determination of
whether a stock is ``strategic'' (16 U.S.C. 1362(19))), but nothing in
the MMPA requires the application of PBR outside the management of
commercial fisheries interactions with marine mammals.
Nonetheless, NMFS recognizes that as a quantitative tool, PBR may
be useful in certain instances as a consideration when evaluating the
impacts of other human-caused activities on marine mammal stocks.
Outside the commercial fishing context, PBR can help inform the
potential effects of M/SI, most readily for determining when
anticipated M/SI clearly would not contribute to exceeding the
negligible impact level. We first calculate a metric for each

[[Page 11068]]

species or stock that incorporates information regarding ongoing
anthropogenic mortality/serious injury into the PBR value (i.e., PBR
minus the total annual anthropogenic mortality/serious injury
estimate), which is called ``residual PBR.'' (Wood et al., 2012). We
then consider the maximum potential incidental M/SI from the activities
being evaluated relative to an insignificance threshold, which is 10
percent of residual PBR for that species or stock. For a species or
stock with incidental M/SI less than 10 percent of residual PBR, we
consider M/SI from the specified activities to represent an
insignificant incremental increase in ongoing anthropogenic M/SI that
alone (i.e., in the absence of any other take) cannot affect annual
rates of recruitment and survival. In a prior incidental take
rulemaking and in the commercial fishing context, this threshold is
identified as the significance threshold, but it is more accurately an
insignificance threshold outside commercial fishing because it
represents the level at which there is no need to consider other
factors in determining the role of M/SI in affecting rates of
recruitment and survival. Assuming that any additional incidental take
by harassment would not exceed the negligible impact level, the
anticipated M/SI caused by the activities being evaluated would have a
negligible impact on the species or stock.
Where M/SI for a species or stock exceeds the insignificance
threshold--or even residual PBR--that information is relevant to, but
not determinative of, whether the M/SI along with any anticipated take
by harassment exceeds negligible impact. We also consider all relevant
information that could either increase or reduce the level of concern
related to the significance of a given level of take. Specifically, we
consider implementation of mitigation measures, additional population
stressors, and other possible effects--both positive and negative--in
addition to the interaction of those mortalities with incidental taking
by harassment.
Our evaluation of the M/SI for each of the species and stocks for
which mortality could occur follows. No mortalities or serious injuries
are anticipated from Navy's sonar activities. In addition, all
mortality authorized for some of the same species or stocks over the
next several years pursuant to our final rulemaking for the NMFS
Northeast Fisheries Science Center has been incorporated into the
residual PBR.
We first consider maximum potential incidental M/SI from Navy's
ship strike analysis for the affected mysticetes and sperm whales (see
Table 70) and from the Navy's explosive detonations for the affected
dolphin species (see Table 71) in consideration of NMFS's threshold for
identifying insignificant M/SI take (10 percent of residual PBR (69 FR
43338; July 20, 2004)). By considering the maximum potential incidental
M/SI in relation to PBR and ongoing sources of anthropogenic mortality,
we begin our evaluation of whether the potential incremental addition
of M/SI through Navy's ship strikes and explosive detonations may
affect the species' or stock's annual rates of recruitment or survival.
We also consider the interaction of those mortalities with incidental
taking of that species or stock by harassment pursuant to the specified
activity.
Based on the methods discussed previously, NMFS believes that
mortal takes of three large whales over the course of the five-year
rule could occur, but that no more than one of any species of humpback
whale, fin whale, sei whale, minke whale, blue whale, or sperm whale
(either GOM or North Atlantic) would occur. This means an annual
average of 0.2 whales from each species as described in Table 70 (i.e.,
1 take over 5 years divided by 5 to get the annual number) is proposed
for authorization.
The Navy has also requested a small number of takes by serious
injury or mortality from explosives. To calculate the annual average of
mortalities for explosives in Table 71 we used the same method as
described for vessel strikes. The annual average is the number of takes
divided by 5 years to get the annual number.

Table 70--Summary Information Related to AFTT Ship Strike, 2018-2023
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Annual
proposed Residual
Stock take by Total Fisheries interactions (Y/ Vessel collisions (Y/ NEFSC PBR-PBR Stock
Species (stock) abundance serious annual M/ N); annual rate of M/SI N); annual rate of M/SI PBR * authorized minus trend * UME (Y/N); number and
(Nbest) * injury or SI * \2\ from fisheries from vessel collision * take annual M/SI \4\ year
mortality interactions * (annual) (%) \3\
\1\
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Fin whale (Western North Atlantic). 1,618 0.2 3.8 Y; 1.8................... Y; 2................... 2.5 0 -1.3 ? N
Sei whale (Nova Scotia)............ 357 0.2 0.8 N........................ Y; 0.8................. 0.5 0 -0.3 ? N
Minke Whale (Canadian East Coast).. 2,591 0.2 8.25 Y; 6.45.................. Y; 1.6................. 14 1 4.75 ? ?
Blue whale (Western North Atlantic) unknown 0.2 unknown N........................ N...................... 0.9 0 unknown ? ?
Humpback whale (Gulf of Maine)..... 823 0.2 9.05 Y; 7.25.................. Y; 1.8................. 13 0 3.95 [uarr] Y/27 in 2017 (53 in
2016 and 2017
combined).
Sperm whale (North Atlantic)....... 2,288 0.2 0.8 Y; 0.8................... Y; 0.2................. 3.6 0 2.8 ? ?
Sperm whale (Gulf of Mexico)....... 763 0.2 0 N........................ N...................... 1.1 0 1.1 ? Y/5 in 2010-2014.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* Presented in the SARS.
\1\ This column represent the annual take by serious injury or mortality by vessel collision and was calculated by the number of mortalities proposed for authorization divided by five years
(the length of the rule and LOAs).
\2\ This column represents the total number of incidents of M/SI that could potentially accrue to the specified species or stock. This number comes from the SAR, but deducts the takes accrued
from either Navy strikes or NEFSC takes to ensure not double-counted against PBR. However, for these species, there were no were no takes from either Navy or NEFSC to deduct that would be
considered double-counting.
\3\ This value represents the calculated PBR less the average annual estimate of ongoing anthropogenic mortalities (i.e., total annual human-caused M/SI, which is presented in the SARs).
\4\ See relevant SARs for more information regarding stock status and trends.

[[Page 11069]]

Table 71. Summary Information Related to AFTT Serious Injury or Mortality From Explosives (Ship Shock Trials), 2018-2023
--------------------------------------------------------------------------------------------------------------------------------------------------------
Annual
proposed Fisheries Residual
Stock take by Total interactions NEFSC PBR-PBR Stock
Species (stock) abundance serious annual (Y/N); annual PBR * authorized minus trend * UME (Y/N); number and
(Nbest) * injury or M/SI* rate of M/SI take (annual) annual M/SI \4\ year
mortality \2\ from fisheries \3\
\1\ interactions *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Atlantic white-sided dolphin 48,819 0.2 74 74 304 0.6 230 ? N
(Western N. Atlantic).
Pantropical spotted dolphin 50,880 0.2 4.4 4.4 407 0 402.6 ? Y/3 in 2010-2014.
(Northern Gulf of Mexico).
Short-beaked common dolphin 70,184 1.2 409 409 577 2 168 ? N
(Western N. Atlantic).
Spinner dolphin (Northern Gulf 11,411 0.2 0 0 62 0 62 ? Y/7 in 2010-2014.
of Mexico).
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Presented in the SARS.
\1\ This column represents the annual take by serious injury or mortality during ship shock trials and was calculated by the number of mortalities
proposed for authorization divided by five years (the length of the rule and LOAs).
\2\ This column represents the total number of incidents of M/SI that could potentially accrue to the specified species or stock. This number comes from
the SAR, but deducts the takes accrued from either Navy or NEFSC takes to ensure not double-counted against PBR. However, for these species, there
were no were no takes from either Navy or NEFSC to deduct that would be considered double-counting.
\3\ This value represents the calculated PBR less the average annual estimate of ongoing anthropogenic mortalities (i.e., total annual human-caused M/
SI, which is presented in the SARs).
\4\ See relevant SARs for more information regarding stock status and trends.

Humpback Whale

For humpback whale (Gulf of Maine stock) PBR is currently set at 13
and the total annual M/SI of 9.05 yielding a residual PBR of 3.95. The
M/SI value includes incidental fishery interaction records of 7.25, and
records of vessel collisions of 1.8. The proposed authorization of 0.2
mortalities is below the insignificance threshold of 10 percent of
residual PBR (0.395); therefore, we consider the addition of 0.2 an
insignificant incremental addition to human-caused mortality. This
information will be considered in combination with our assessment of
the impacts of harassment takes later in the section.
While the proposed authorization of mortalities is below the
insignificant threshold, because of the going UME for humpback whales,
we address what actions may be occurring that may reduce the risk of
mortalities of humpbacks. Of note, the Atlantic Large Whale Take
Reduction Plan (ALWTRP) is a program to reduce the risk of serious
injury and death of large whales caused by accidental entanglement in
U.S. commercial trap/pot and gillnet fishing gear. It aims to reduce
the number of whales taken by gear entanglements focusing on fin
whales, humpback whales, and NARW. Effective September 1, 2015 the
ALWTRP included new gear marking areas for gillnets and trap/pots for
Jeffrey's Ledge and Jordan Basin (Gulf of Maine), two important high-
use areas for humpback whales and NARWs. The only study available that
examined the effectiveness of the ALWTRP reviewed the regulations up to
2009 (Pace et al. 2014) and the results called for additional
mitigation measures needed to reduce entanglements. After this study
period, NMFS put two major regulatory actions in place--the 2007
sinking groundline rule that went into effect in 2009 (73 FR 51228) and
the 2014 vertical line rule that went into effect in 2015 (79 FR
36586). NMFS Fisheries Science Centers are convening a working group in
January 2018 to make recommendations on the best analytical approach to
measure how effective these regulations have been. However, the Office
of Law Enforcement (OLE) report that of gear checked by OLE under the
ALWTRP, they found a compliance rate of 94.49 percent in FY-2015 and
84.42 percent in FY-2016.

Sperm Whale (North Atlantic)

For sperm whales (North Atlantic stock) PBR is currently set at 3.6
and the total annual M/SI of 0.8 yielding a residual PBR of 2.8. The M/
SI value includes incidental fishery interaction records of 0.6, and
records of vessel collisions of 2.0. The proposed authorization of 0.2
mortalities falls below the insignificance threshold of 10 percent of
residual PBR (0.28), therefore, we consider the addition of 0.2 an
insignificant incremental addition to human-caused mortality. This
information will be considered in combination with our assessment of
the impacts of harassment takes later in the section.

Sperm Whale (Gulf of Mexico)

For sperm whales (Gulf of Mexico stock) PBR is currently set at 1.1
and the total annual M/SI of 0 yielding a residual PBR of 1.1. The M/SI
value includes incidental fishery interaction records of 0, and records
of vessel collisions of 0. The proposed authorization of 0.2
mortalities does not fall below the insignificance threshold of 10
percent of residual PBR (0.11), but is below residual PBR, which means
that the total anticipated human-caused mortality is still not expected
to exceed that needed to allow the stock to reach or maintain its OSP
level. The information contained here will be considered in combination
with the harassment assessment included later in this section.
Additional information on sperm whale mortalities was considered in
our analysis because the proposed mortalities did not fall below the
insignificant threshold of 10 percent of residual PBR (however, still
below residual PBR). Sperm whales associated with a UME (described
below) appears to be an isolated event and the UME investigation
determined that the DWH oil spill is the most likely explanation for
the elevated stranding numbers in the northern Gulf of Mexico. An UME
was declared for cetaceans in the northern Gulf of Mexico 2010-2014
(for more information refer to the Description of Marine Mammals
section). During 2010-2013, five sperm whales from this stock were
considered to be part of the UME. No vessel strikes have been
documented in recent years (2009-2013) for sperm whales in the Gulf of
Mexico. Historically, one possible sperm whale mortality due to a
vessel strike has been documented for the Gulf of Mexico. The incident
occurred in 1990 in the vicinity of Grande Isle, Louisiana. Deep cuts
on the dorsal surface of the whale indicated the ship strike was
probably pre-mortem (Jensen and Silber 2004). The status of sperm
whales in the northern Gulf of Mexico, relative to OSP, is unknown.

[[Page 11070]]

There are insufficient data to determine the population trends for this
stock.

Minke Whale

For minke whales (Canadian East Coast stock) PBR is currently set
at 14 and the total annual M/SI of 8.25 yielding a residual PBR of
5.75. The M/SI value includes incidental fishery interaction records of
6.45, and records of vessel collisions of 1.6. The proposed
authorization of 0.2 mortalities annually from the Navy's activities
(in addition to the 1.0 annual mortality from the NEFSC) yields a total
of 1.2 mortalities, which does not fall below the insignificance
threshold of 10 percent of residual PBR (0.575), but is below residual
PBR. This means that the total anticipated human-caused mortality is
still not expected to exceed that needed to allow the stock to reach or
maintain its OSP level. In addition, the abundance of minke whales is
likely greater as the most recent estimate is substantially lower than
the estimate from the previous 2015 SAR abundance (20,741 minkes with a
PBR of 162). The 2015 SAR abundance included data from the 2007
Canadian Trans-North Atlantic Sighting Surveys (TNASS) while the
current estimate did not. For the purposes of the 2016 SAR, as
recommended in the GAMMS II Workshop Report (Wade and Angliss 1997),
estimates older than eight years are deemed unreliable, so the 2016 SAR
estimate must not include data from the 2007 TNASS. The 2016 SARS
indicated that the estimate should not be interpreted as a decline in
abundance of this stock, as previous estimates are not directly
comparable. Therefore, the PBR is likely much greater for this species,
which could mean that the real residual PBR may not be exceeded. The
information contained here will be considered in combination with the
harassment assessment included later in this section.

Blue Whale

For blue whales (Western North Atlantic stock) PBR is currently set
at 0.9 and the total annual M/SI is unknown and therefore residual PBR
is unknown. The proposed authorization of 0.2 mortalities is below PBR
and there is no other known mortality, so the total anticipated human-
caused mortality is not expected to exceed PBR. Additional information
on blue whale mortalities was considered in our analysis because the
proposed mortalities did not fall below the insignificant threshold of
10 percent of residual PBR (however, still below PBR). There have been
no observed fishery-related mortalities or serious injury. There are no
recent confirmed records of mortality or serious injury to blue whales
in the U.S. Atlantic EEZ. One historical record points to a ship
strike; however it was concluded that the whale may have been died
outside the U.S. Atlantic EEZ. In March 1998, a dead 20 m (66 ft) male
blue whale was brought into Rhode Island waters on the bow of a tanker.
The cause of death was determined to be ship strike; however, some of
the injuries were difficult to explain from the necropsy. Therefore, we
think the likelihood of the Navy hitting a blue whale is discountable.
There are insufficient data to determine population trends for this
species. This information will be considered in combination with our
assessment of the impacts of harassment takes later in the section.

Fin Whale

For fin whales (Western North Atlantic stock) PBR is currently set
at 2.5 and the total annual M/SI of 3.8 yielding a residual PBR of -
1.3. The fact that residual PBR is negative means that the total
anticipated human-caused mortality is expected to exceed PBR even in
the absence of additional take by the Navy. However, we note that there
is a strong likelihood the abundance estimate used to calculate PBR was
biased low due to incomplete coverage of the stock's range, and,
therefore, this PBR calculation is likely low. The best abundance
estimate available for the fin whale stock is 1,618 and that it is
likely that the available estimate underestimates this stock's
abundance because much of the stock's range was not included in the
surveys upon which the estimate is based.
Proposed mortality above residual PBR (however, still below PBR)
necessitates the consideration of all additional available information
on mortality in the analysis. Of note, the ALWTRP (as described above)
is a program to reduce the risk of serious injury and death of large
whales caused by accidental entanglement in U.S. commercial trap/pot
and gillnet fishing gear. It aims to reduce the number of whales taken
by gear entanglements focusing on fin whales, humpback whales, and
NARW. NMFS Fisheries Science Centers are convening a working group in
January 2018 to make recommendations on the best analytical approach to
measure how effective these regulations have been.
As noted previously, PBR, as a tool, is inherently conservative and
is not intended to be used as an absolute cap. The Navy's proposed
serious injury or mortality take of 0.2 individual fin whales is low in
and of itself (the lowest non-zero value possible over a five-year
period), and as a portion of the total projected overage of human-
caused mortality of 3.8. Additionally, as noted above, PBR may be
underestimated, which could mean that the real residual PBR may not be
exceeded. However, the exceedance of residual PBR necessitates that
close attention to the remainder of the impacts on fin whales from this
activity to ensure that the total authorized impacts are negligible.

Sei Whale

For sei whales (Nova Scotia stock) PBR is currently set at 0.5 and
the total annual M/SI of 0.8 yielding a residual PBR of -0.3. The M/SI
value includes incidental fishery interaction records of 0, and records
of vessel collisions of 0.8. The fact that residual PBR is negative
means that the total anticipated human-caused mortality is expected to
exceed PBR even in the absence of additional take by the Navy. However,
we note that there is a strong likelihood the abundance estimate used
to calculate PBR was biased low due to incomplete coverage of the
stock's range, and, therefore, this PBR calculation may also be low. It
should be noted that the population abundance estimate of 357 is
considered the best available for the Nova Scotia stock of sei whales.
However, this estimate must be considered conservative because all of
the known range of this stock was not surveyed. It should be noted that
the abundance survey from which it was derived excluded waters off the
Scotian Shelf, an area encompassing a large portion of the stated range
of the stock. The status of this stock relative to OSP in the U.S.
Atlantic EEZ is unknown. There are insufficient data to determine
population trends for sei whales.
Proposed mortality above residual PBR (however, still below PBR)
necessitates the consideration of all additional available information
on mortality in the analysis. As noted previously, PBR, as a tool, is
inherently conservative and is not intended to be used as an absolute
cap. The Navy's proposed serious injury or mortality take of 0.2
individual sei whales is low in and of itself (the lowest non-zero
value possible over a five-year period), and the total projected
overage of human-caused mortality of 0.8 is also low. However, the
exceedance of residual PBR necessitates that close attention to the
remainder of the impacts on sei whales from the Navy's activities to
ensure that the total authorized impacts are negligible.

[[Page 11071]]

Atlantic White-Sided Dolphin

For Atlantic white-sided dolphins (Western Atlantic stock) PBR is
currently set at 304 and the total annual M/SI of 74 yielding a
residual PBR of 230. The proposed authorization of 0.2 mortalities from
the Navy's activities (in addition to 0.6 mortalities from the NEFSC)
yields a total of 0.8 mortalities, which falls below the insignificance
threshold of 10 percent of residual PBR (23.0). Therefore, we consider
the addition of 0.8 an insignificant incremental increase to human-
caused mortality and do not consider additional factors related to
mortality further. This information will be considered in combination
with our assessment of the impacts of harassment takes later in the
section.

Pantropical Spotted Dolphin

The Pantropical spotted dolphins (Northern Gulf of Mexico stock)
PBR is currently set at 407 and the total annual M/SI of 4.4 yielding a
residual PBR of 402.6. The proposed authorization of 0.2 mortalities
annually falls below the insignificance threshold of 10 percent of
residual PBR (40.26) and, therefore, we consider the addition of 0.2 an
insignificant incremental increase to human-caused mortality and do not
consider additional factors related to mortality further. This
information will be considered in combination with our assessment of
the impacts of harassment takes later in the section.

Short-Beaked Common Dolphin

For short-beaked common dolphins (Western North Atlantic stock) PBR
is currently set at 577 and the total annual M/SI of 409 yielding a
residual PBR of 168. The proposed authorization of 1.2 mortalities
annually from the Navy's activities (in addition to the 2.0 mortalities
from the NEFSC) yields a total of 3.2 mortalities annually and falls
below the insignificance threshold of 10 percent of residual PBR (16.8)
and, therefore, we consider the addition of 3.2 an insignificant
incremental increase to human-caused mortality and do not consider
additional factors related to mortality further. This information will
be considered in combination with our assessment of the impacts of
harassment takes later in the section.

Spinner Dolphin

The spinner dolphins (Northern Gulf of Mexico stock) PBR is
currently set at 62 and the total annual M/SI of 0 yielding a residual
PBR of 62. The proposed authorization of 0.2 mortalities annually falls
below the insignificance threshold of 10 percent of residual PBR (6.2)
and, therefore, we consider the addition of 0.2 an insignificant
incremental increase to human-caused mortality and do not consider
additional factors related to mortality further. This information will
be considered in combination with our assessment of the impacts of
harassment.

Group and Species-Specific Analysis

In the discussions below, the ``acoustic analysis'' refers to the
Navy's analysis, which includes the use of several models and other
applicable calculations as described in the Estimated Take of Marine
Mammals section. The quantitative analysis process used for the AFTT
DEIS/OEIS and the Navy's rulemaking and LOA application to estimate
potential exposures to marine mammals resulting from acoustic and
explosive stressors is detailed in the technical report titled
Quantitative Analysis for Estimating Acoustic and Explosive Impacts to
Marine Mammals and Sea Turtles (U.S. Department of the Navy, 2017a).
The Navy Acoustic Effects Model estimates acoustic and explosive
effects without taking mitigation into account; therefore, the model
overestimates predicted impacts on marine mammals within mitigation
zones. To account for mitigation, as well as avoidance, for marine
mammals, the Navy developed a methodology to conservatively quantify
the likely degree that mitigation and avoidance will reduce model-
estimated PTS to TTS for exposures to sonar and other transducers, and
reduce model-estimated mortality and injury for exposures to
explosives.
The amount and type of incidental take of marine mammals
anticipated to occur from exposures to sonar and other active acoustic
sources and explosions during the five-year training and testing period
are shown in Tables 39 and 40 as well as ship shock trials shown in
Table 41. The vast majority of predicted exposures (greater than 99
percent) are expected to be Level B harassment (non-injurious TTS and
behavioral reactions) from acoustic and explosive sources during
training and testing activities at relatively low received levels.
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. Animals belonging to each stock within a species would have
the same hearing capabilities and behaviorally respond in the same
manner as animals in other stocks within the species. Therefore our
analysis below also considers the effects of Navy's activities on each
affected stock. Where there are meaningful differences between species
or stocks 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.
Mysticetes
In Table 72 below, for mysticetes, we indicate the total annual
mortality, Level A and Level B harassment, and a number indicating the
instances of total take as a percentage of abundance. Overall, takes
from Level A harassment (PTS and Tissue Damage) account for less than
one percent of all total takes.

[[Page 11072]]

[GRAPHIC] [TIFF OMITTED] TP13MR18.024

Of these species, North Atlantic right whale, blue whale, fin
whale, and sei whale are listed as endangered under the ESA and
depleted under the MMPA. NMFS is currently engaged in an internal
Section 7 consultation under the ESA and the outcome of that
consultation will further inform our final decision.
As noted previously, the estimated takes represent instances of
take, not the number of individuals taken, and in almost all cases--
some individuals are expected to be taken more than one time, which
means that the number of individuals taken is smaller than the total
estimated takes. In other words, where the instances of take exceed 100
percent of the population, repeated takes of some individuals are
predicted. Generally speaking, the higher the number of takes as
compared to the population abundance, the more repeated takes of
individuals are likely, and the higher the actual percentage of
individuals in the population that are likely taken at least once in a
year. We look at this comparative metric to give us a relative sense
across species/stocks of where larger portions of the stocks are being
taken by Navy activities and where there is a higher likelihood that
the same individuals are being taken across multiple days and where
that number of days might be higher. In the ocean, the use of sonar and
other active acoustic sources is often transient and is unlikely to
repeatedly expose the same individual animals within a short period,
for example within one specific exercise. However, some repeated
exposures across different activities could occur over the year,
especially where numerous activities occur in generally the same area
with more resident species. In short, we expect that the total
anticipated takes represent exposures of a smaller number of
individuals of which some would be exposed multiple times, but based on
the nature of the Navy's activities and the movement patterns of marine
mammals, it is unlikely that any particular subset would be taken over
more than a few sequential days--i.e., where repeated takes of
individuals are likely to occur. They are more likely to result from
non-sequential exposures from different activities and marine mammals
are not predicted to be taken for more than a few days in a row, at
most. As described elsewhere, the nature of the majority of the
exposures would be expected to be of a less severe nature and based on
the numbers it is still likely that any individual exposed multiple
time is still only taken on a small percentage of the days of the year.
Use of sonar and other transducers would typically be transient and
temporary. The majority of acoustic effects to mysticetes from sonar
and other active sound sources during testing and training activities
would be primarily from ASW events. It is important to note although
ASW is one of the warfare areas of focus during MTEs, there are
significant periods when active ASW sonars are not in use.
Nevertheless, behavioral reactions are assumed more likely to be
significant during MTEs than during other ASW activities due to the
duration (i.e., multiple days) and scale (i.e., multiple sonar
platforms) of the MTEs. In other words, in the range of potential
behavioral effects that might expect to be part of a response that
qualifies as an instance take (which by nature of the way it is
modeled/counted, occurs within one day), the less severe end might
include exposure to comparatively lower levels of a sound, at a
detectably greater distance from the animal, for a few or several
minutes, and that could result in a behavioral response such as
avoiding an area that an animal would otherwise have chosen to move
through or feed in for some amount of time or breaking off one or a few
feeding bouts. The more severe end, which occurs a smaller amount of
the time (when the animal gets close enough to the source to receive a
comparatively higher level, is exposed continuously to one source for a
longer time, or is exposed intermittently to different sources
throughout a day) might result in an animal having a more severe flight
response and leaving a larger area for a day or more or potentially
losing feeding opportunities for a day. As noted in the Potential
Effects section, there are multiple

[[Page 11073]]

examples from behavioral response studies of odontocetes ceasing their
feeding dives when exposed to sonar pulses at certain levels, but
alternately, blue whales were less likely to show a visible response to
sonar exposures at certain levels when feeding then they have been
observed responding to when traveling.
Most Level B harassments to mysticetes from hull-mounted sonar
(MF1) in the AFTT Study Area would result from received levels between
160 and 172 dB SPL (64 percent). Therefore, the majority of Level B
takes are expected to be in the form of milder responses (i.e., lower-
level exposures that still rise to the level of take, but would likely
be less severe in the range of responses that qualify as take) of a
generally shorter duration. As mentioned earlier in this section, we
anticipate more severe effects from takes when animals are exposed to
higher received levels. Occasional milder behavioral reactions are
unlikely to cause long-term consequences for individual animals or
populations, and even if some smaller subset of the takes are in the
form of a longer (several hours or a day) and more moderate response,
because they are not expected to be repeated over sequential multiple
days, impacts to individual fitness are not anticipated.
Research and observations show that if mysticetes are exposed to
sonar or other active acoustic sources they may react in a number of
ways depending on the characteristics of the sound source, their
experience with the sound source, and whether they are migrating or on
seasonal grounds (i.e., breeding or feeding). Behavioral reactions may
include alerting, breaking off feeding dives and surfacing, diving or
swimming away, or no response at all (Richardson, 1995; Nowacek, 2007;
Southall et al., 2007; Finneran and Jenkins, 2012). Overall, mysticetes
have been observed to be more reactive to acoustic disturbance when a
noise sources is located directly on their migration route. Mysticetes
disturbed while migrating could pause their migration or route around
the disturbance. Although they may pause temporarily, they will resume
migration shortly after. Animals disturbed while engaged in other
activities such as feeding or reproductive behaviors may be more likely
to ignore or tolerate the disturbance and continue their natural
behavior patterns. Therefore, most behavioral reactions from mysticetes
are likely to be short-term and low to moderate severity.
While MTEs may have a longer duration they are not concentrated in
small geographic areas over that time period. MTES use thousands to 10s
of thousands of square miles of ocean space during the course of the
event. There is no Navy activity in the proposed action that is both
long in duration (more than a day) and concentrated in the same
location. For example, Goldbogen et al. (2013) indicated some
horizontal displacement of deep foraging blue whales in response to
simulated MFA sonar. Given these animals' mobility and large ranges, we
would expect these individuals to temporarily select alternative
foraging sites nearby until the exposure levels in their initially
selected foraging area have decreased. Therefore, temporary
displacement from initially selected foraging habitat is not expected
to impact the fitness of any individual animals because we would expect
suitable foraging to be available in close proximity.
Richardson et al. (1995) noted that avoidance (temporary
displacement of an individual from an area) reactions are the most
obvious manifestations of disturbance in marine mammals. Avoidance is
qualitatively different from the startle or 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. Some mysticetes may avoid larger
activities such as a MTE as it moves through an area, although these
activities generally do not use the same training locations day-after-
day during multi-day activities. Therefore, displaced animals could
return quickly after the MTE finishes. Due to the limited number and
broad geographic scope of MTEs, it is unlikely that most mysticetes
would encounter a major training exercise more than once per year and
no MTEs will occur in the Gulf of Mexico Planning Awareness Area. In
the ocean, the use of sonar and other active acoustic sources is
transient and is unlikely to expose the same population of animals
repeatedly over a short period except around homeports and fixed
instrumented ranges.
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, though we have
analyzed the impacts that are anticipated to occur that we have
therefore proposed to authorize. As noted previously, when an animal
incurs a threshold shift, it occurs in the frequency from that of the
source up to one octave above--this means that threshold shift caused
by Navy sonar sources will typically occur in the range of 2-20 kHz,
and if resulting from hull-mounted sonar, will be in the range of 3.5-7
kHz. The majority of mysticete vocalizations, including for right
whales, occurs in frequencies below 1kHz, which means that TTS incurred
by mysticetes will not interfere with conspecific communication. When
we look in ocean areas where the Navy has been intensively training and
testing with sonar and other active acoustic sources for decades, there
is no data suggesting any long-term consequences to mysticetes from
exposure to sonar and other active acoustic sources.
The Navy will implement mitigation areas that will avoid or reduce
impacts to mysticetes and contains BIAs for large whales and critical
habitat for NARW. The NARW is a small, at risk species with an ongoing
UME. In order to mitigate the number and potential severity of any NARW
takes, from November 15 through April 15, the Navy will not conduct
LFAS/MFAS/HFAS, except for sources that will be minimized to the
maximum extent practicable during helicopter dipping, navigation
training, and object detection exercises within the Southeast NARW
Mitigation Area. As discussed previously, the majority of takes result
from exposure to the higher power hull-mounted sonar during major
training exercises, which will not occur here. The activities that are
allowed to occur such as those used for navigation training or object
detection exercises use lower level sources that operate in a manner
less likely to result in more concerning affects (i.e., single sources
for shorter overall amounts of time--e.g., activity is less than two
hours). Animals in these protected areas are engaged in important
behaviors, either feeding or interacting with calves, during which if
they were disturbed the impacts could be more impactful (e.g., if
whales were displaced from preferred feeding habitat for weeks, there
could be energetic consequences more likely to lead to an adverse
effects on fitness, or if exposure to activities caused a severe
disturbance to a cow-calf pair that resulted in the pair becoming
separated, it could increase the risk of predation for the calf). By
limiting activities in these, the number of takes that would occur in
areas is decreased and the probability of a more severe impact is
reduced. The Southeast NARW Mitigation Area encompasses a portion of
the NARW migration and calving areas identified by LaBrecque et al.
(2015a) and a portion of the southeastern NARW critical habitat.
Outside of the Southeast NARW

[[Page 11074]]

Mitigation Area, active sonar would be used for ASW activities and for
pierside sonar testing at Kings Bay, Georgia. The best available
density data for the AFTT Study Area shows that the areas of highest
density are off the southeastern United States in areas that coincide
with the Southeast NARW Mitigation Area. Therefore, the majority of
active sonar use would occur outside of the areas of highest seasonal
NARW density and important use off the southeastern United States. In
addition, before transiting or conducting testing and training
activities, the Navy will coordinate to obtain Early Warning System
NARW sighting data to help vessels and aircraft reduce potential
interactions with NARWs.
The Navy will also minimize the use of active sonar in the
Northeast NARW Mitigation Area. Refer to Proposed Mitigation Measures
for a description of the area. A limited number of torpedo activities
(non-explosive) would be conducted in August and September. Many NARW
will have migrated south out of the area by that time. Torpedo training
or testing activities would not occur within 2.7 nmi of the Stellwagen
Bank NMS which is critical habitat for NARW foraging. Stellwagen Bank
NMS also provides feeding and nursery grounds for NARW, humpback, sei
and fin whales. The Northeast NARW Mitigation Area also contains the
NARW feedings BIAs (3), NARW mating BIA (1), and NARW critical habitat.
The large whale feeding BIAs are included in the Navy's Gulf of
Maine Mitigation Area. The humpback whale (1), minke whale (2), fin
whale (2), and sei whale (1) feeding BIAs are within the Gulf of Maine
Mitigation Area where the Navy will not plan MTEs, and will not conduct
more than 200 hrs of hull-mounted MFAS per year. The Northeast
Mitigation Area, which is just south of the Gulf of Maine Mitigation
Area, will also avoid MTEs to the maximum extent possible and not
conduct more than four MTEs per year.
The Bryde's whale BIA is inclusive of the Gulf of Mexico Planning
Awareness Mitigation Areas where the Navy will avoid planning MTEs
(i.e., Composite Training Unit Exercises or Fleet Exercises/Sustainment
Exercises) involving the use of active sonar to the maximum extent
practicable. The Navy will not conduct any major training exercises in
the Gulf of Mexico Planning Awareness Mitigation Areas under the
Proposed Activity.
As described previously there are three ongoing UMEs for NARW,
humpback whales, and minke whales. There is significant concern
regarding the status of the NARW, both because of the ongoing UME and
because of the overall status of the stock. However, the Navy's
mitigation measures make NARW mortality unlikely--and we do not propose
to authorize such take--and the newly expanded mitigation areas further
reduce the extent of potential behavioral disruption in areas that are
important for NARW, hence reducing the significance of such disruption.
NMFS also has concern regarding the UME for humpback whales. NMFS, in
coordination with our stranding network partners, continue to
investigate the recent mortalities, environmental conditions, and
population monitoring to better understand how the recent humpback
whale mortalities occurred. Ship speed reduction rules are in effect
for commercial and large vessel during high concentrations of NARW, and
require vessels greater than or equal to 65 feet in length to reduce
speeds to 10 knots or less while entering or departing ports. While
this rule was put into place primarily for the NARW presence in New
England and Mid-Atlantic waters, it does benefit other whale species,
such as humpback whales that are in those areas from November through
July. NOAA is reviewing ship-tracking data to ensure compliance with
the ship speed reduction rule around Cape Cod, New York, and the
Chesapeake Bay areas. However, the Navy's mitigation measures make
humpback mortality low to unlikely and therefore, NMFS proposes to
authorize only one mortality over the entire five-year period of the
rule. The UME for minke whales was recently declared. More research is
needed on the preliminary findings of the necropsies. As part of the
UME investigation process, NOAA is assembling an independent team of
scientists to coordinate with the Working Group on Marine Mammal
Unusual Mortality Events to review the data collected, sample stranded
whales, and determine the next steps for the investigation.
In summary and as described above, the following information
primarily supports our preliminary determination that the impacts
resulting from Navy's activities are not expected to adversely affect
the mysticete stocks taken through effects on annual rates of
recruitment or survival:
As described in the ``Serious Injury or Mortality''
section above, up to one serious injury or mortality over five years is
proposed for authorization for large whales (see Table 70). As
described above, the proposed mortality for humpback whale and sperm
whale (North Atlantic stock) fall below the insignificance threshold,
the proposed mortality for the sperm whale (Gulf of Mexico stock) and
minke whale is below residual PBR, and while residual PBR is not known
for blue whales (as total annual M/SI is unknown), no other fishery-
related or ship strike mortalities are known to have occurred, so the
total human-caused mortality is very low. The total human-caused
mortality for fin and sei whales is already projected to exceed PBR
even in the absence of additional mortality caused by the Navy.
However, as discussed in greater detail previously, the ALWTRP is in
place to reduce the likelihood of entanglement of large whales by trap/
pot and gillnet fishing gear and NMFS is currently analyzing its
effectiveness. When we consider the factors discussed above, the fact
that the PBR metric is inherently conservative, and the fact that the
Navy's potential incremental increase in the mortal takes is
fractionally small (0.2 annually) are considered, NMFS believes that
this single death over five years will not result in adverse impacts on
annual rates of recruitment or survival.
As described above, any PTS that may occur is expected to
be of a small degree, and any TTS of a relatively small degree because
of the unlikelihood that animals would be close enough for a long
enough period of time to incur more severe PTS (for sonar) and the
anticipated effectiveness of mitigation in preventing very close
exposures for explosives. Further, as noted above, any threshold shift
incurred from sonar would be in the frequency range of 2-20 kHz, which
above the frequency of the majority of mysticete vocalizations, and
therefore would not be expected to interfere with conspecific
communication.
While the majority of takes are caused by exposure during
ASW activities the impacts from these exposures are not expected to
have either significant or long-term effects because (and as discussed
above):
[cir] ASW activities typically involve fast-moving assets (relative
to marine mammal swim speeds) and individuals are not expected to be
exposed either for long periods within a day or over many sequential
days,
[cir] As discussed, the majority of the harassment takes result
from hull-mounted sonar during MTEs. When distance cut offs for
mysticetes are applied, this means that all of the takes from hull-
mounted sonar (MF1) result from above exposure 160 dB. However, the
majority (e.g., 64 percent) of the takes results from exposures below
172 dB. The majority of the takes have a relatively lower likelihood to
have severe impacts.

[[Page 11075]]

For the total instances of all of the different types of
takes, the numbers indicating the instances of total take as a
percentage of abundance are between 7 and 118 percent over the whole
Navy Study Area, and between 118 and 672 percent in the US EEZ alone
(Table 72). While these percentages may seem high, when spread over the
entire year and a very large range, the scale of the effects are such
that over the whole Navy Study area, individuals are taken an average
of 0 or 1-2 times per year, and some subset of these individuals in the
US EEZ are taken an average of 1-7 times (based on the percentages
above, respectively, but with some taken more or less). These averages
allow that perhaps a smaller subset is taken with a slightly higher
average and larger variability of highs and lows, but still with no
reason to think that any individuals would be taken every day for weeks
or months out of the year, much less on sequential days. These
behavioral takes are not all expected to be of particularly high
intensity and nor are they likely to occur over sequential days, which
suggests that the overall scale of impacts for any individual would be
relatively low.
NMFS is very concerned about the status of the NARW stock,
both because of the increased number of deaths and because of the
health of the rest of the stock. However, the Navy's mitigation
measures make ship strike unlikely (and it is unauthorized) and the
newly expanded mitigation areas further reduce the behavioral
disruption in areas that are important for NARW, hence reducing the
likelihood of more severe impacts that would be more likely to lead to
fitness impacts, as discussed above.
The Navy's mitigation areas are inclusive of BIAs for
mysticetes and will avoid or reduce the number and severity of impacts
to these stocks (Table 72).
Consequently, the AFTT activities are not expected to adversely
impact rates of recruitment or survival of any of the stocks of
mysticete whales (Table 72 above in this section).
Sperm Whales, Dwarf Sperm Whales, and Pygmy Sperm Whales
In Table 73 below, for sperm whale, dwarf sperm whales, and pygmy
sperm whales, we indicate the total annual mortality, Level A and Level
B harassment, and a number indicating the instances of total take as a
percentage of abundance. Overall, takes from Level A harassment (PTS
and Tissue Damage) account for less than one percent of all total
takes.
[GRAPHIC] [TIFF OMITTED] TP13MR18.025

Sperm whales (Physeter microcephalus) are listed as endangered
under the ESA and depleted under the MMPA. NMFS is currently engaged in
an internal Section 7 consultation under the ESA and the outcome of
that consultation will further inform our final decision.
As noted previously, the estimated takes represent instances of
take, not the number of individuals taken, and in almost all cases--
some individuals are expected to be taken more than one time, which
means that the number of individuals taken is smaller than the total
estimated takes. In other words, where the instances of take exceed 100
percent of the population, repeated takes of some individuals are
predicted. Generally speaking, the higher the number of takes as
compared to the population abundance, the more repeated takes of
individuals are likely, and the higher the actual percentage of
individuals in the population that are likely taken at least once in a
year. We look at this comparative metric to give us a relative sense
across species/stocks of where larger portions of the stocks are being
taken by Navy activities and where there is a higher likelihood that
the same individuals are being taken across multiple days and where
that number of days might be higher. In the ocean, the use of sonar and
other active acoustic sources is often transient and is unlikely to
repeatedly expose the same individual animals within a short period,
for example within one specific exercise, however, some repeated
exposures across different activities could occur over the year,
especially where events occur in the generally the same area with more
resident species. In short, we expect that the total

[[Page 11076]]

anticipated takes represent exposures of a smaller number of
individuals of which some were exposed multiple times, but based on the
nature of the Navy activities and the movement patterns of marine
mammals, it is unlikely any particular subset would be taken over more
than a few sequential days--i.e., where repeated takes of individuals
are likely to occur, they are more likely to result from non-sequential
exposures from different activities and marine mammals are not
predicted to be taken for more than a few days in a row, at most. As
described elsewhere, the nature of the majority of the exposures would
be expected to be of a less severe nature and based on the numbers it
is still likely that any individual exposed multiple times is still
only taken on a small percentage of the days of the year. For example,
the number of dwarf sperm whale and pygmy sperm whale (Western North
Atlantic stocks) takes in the US EEZ are notably higher as compared to
the abundance in the US EEZ, suggesting that on average, 16 percent of
the individuals that comprise the abundance in the US EEZ might be
taken an average of 21 times per year based on the percentages above in
Table 73. The greater likelihood is that not every individual is taken,
or perhaps a smaller subset is taken with a slightly higher average and
larger variability of highs and lows, but still with no reason to think
that any individuals would be taken every day for months out of the
year, much less on sequential days. In addition, although NMFS does not
currently identify a trend for Kogia spp. populations, recent survey
effort and stranding data show a simultaneous increase in at-sea
abundance and strandings, suggesting growing Kogia spp. abundance
(NMFS, 2011; 2013a; Waring et al., 2007; 2013).
Most Level B harassments to sperm whales and Kogia spp. from hull-
mounted sonar (MF1) in the AFTT Study Area would result from received
levels between 160 and 166 dB SPL (66 percent). Therefore, the majority
of Level B takes are expected to be in the form of milder responses
(i.e., lower-level exposures that still rise to the level of take, but
would likely be less severe in the range of responses that qualify as
take) of a generally shorter duration. As mentioned earlier in this
section, we anticipate more severe effects from takes when animals are
exposed to higher received levels. Occasional milder behavioral
reactions are unlikely to cause long-term consequences for individual
animals or populations, and even if some smaller subset of the takes
are in the form of a longer (several hours or a day) and more moderate
response, because they are not expected to be repeated over sequential
multiple days, impacts to individual fitness are not anticipated.
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; Finneran and Jenkins, 2012). 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 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).
The quantitative analysis predicts a few PTS per year from sonar
and other transducers (during training and testing activities);
however, Kogia whales would likely avoid sound levels that could cause
higher levels of TTS (greater than 20 dB) or PTS. TTS and PTS
thresholds for high-frequency cetaceans, including Kogia whales, are
lower than for all other marine mammals, which leads to a higher number
of estimated impacts relative to the number of animals exposed to the
sound as compared to other hearing groups (e.g., mid-frequency
cetaceans).
The Navy will implement a mitigation area that will avoid or reduce
impacts to sperm whales (Physeter microcephalus). Nearly the entire
important sperm whale habitat (Mississippi Canyon) is included in the
Gulf of Mexico Mitigation Area where the Navy will avoid planning MTEs
involving the use of active sonar to the maximum extent practical.
In summary and as described above, the following factors primarily
support our preliminary determination that the impacts resulting from
Navy's activities are not expected to adversely affect sperm whales and
Kogia spp. through effects on annual rates of recruitment or survival:
As described in the ``Serious Injury or Mortality''
section above, up to one mortality over five years (0.2 annually) is
proposed for authorization for sperm whales (either Gulf of Mexico or
North Atlantic stocks). The proposed serious injury or mortality for
sperm whales falls below the insignificant threshold for the North
Atlantic stock. It does not fall below the insignificance threshold for
the Gulf of Mexico stock, but is below residual PBR, which means that
the total anticipated human-caused mortality is not expected to exceed
PBR. Historically, one possible sperm whale mortality due to a vessel
strike has been documented for the Gulf of Mexico in 1990. NMFS
believes that this single death over five years will not result in
adverse impacts on annual rates of recruitment or survival.
As described above, any PTS that may occur is expected to
be of a relatively smaller degree because of the unlikelihood that
animals would be close enough for a long enough amount of time to incur
more severe PTS (for sonar) and the anticipated effectiveness of
mitigation in preventing very close exposures for explosives.
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 (relative to marine mammals swim
speeds), 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.
While the majority of takes are caused by exposure during
ASW activities, the impacts from these exposures are not expected to
have either significant or long-term effects because (and as discussed
above):
[cir] ASW activities typically involve fast-moving assets (relative
to marine mammal swim speeds) and individuals are not expected to be
exposed either for long periods within a day or over many sequential
days,
[cir] As discussed, the majority of the harassment takes result
from hull-mounted sonar during MTEs. When distance cut offs are applied
for odontecetes, this means that all of the takes from hull-mounted
sonar (MF1) result from above exposure 160 dB. However, the majority
(e.g., 66 percent) of the takes results from exposures below 166 dB.
The majority of the takes have a relatively lower likelihood in have
severe impacts.

[[Page 11077]]

For the total instances of all of the different types of
takes, the numbers indicating the instances of total take as a
percentage of abundance are between 54 and 362 percent over the whole
Navy Study Area, and between 54 and 579 percent in the US EEZ alone for
all species except the Western North Atlantic dwarf and pygmy sperm
whales, which are 2116 (Table 73). While these percentages may seem
high, when spread over the entire year and a very large range, the
scale of the effects are such that over the whole Navy Study area,
individuals are taken an average of 0 or 1-4 times per year, and some
subset of these individuals for all but pygmy and dwarf sperm whales in
the US EEZ are taken an average of 1-6 times (based on the percentages
above, respectively, but with some taken more or less). A subset of
dwarf and pygmy sperm whales in the US EEZ (about 16 percent of the
total abundance of the Navy Study Area) could be taken an average of 21
times each. These averages allow that perhaps a smaller subset is taken
with a slightly higher average and larger variability of highs and
lows, but still with no reason to think that any individuals would be
taken every day for weeks or months out of the year, much less on
sequential days. These behavioral takes are not all expected to be of
particularly high intensity and nor are they likely to occur over
sequential days, which suggests that the overall scale of impacts for
any individual would be relatively low.
For the endangered sperm whale (Gulf of Mexico),
additional mitigation measures further reduce the likelihood of
behavioral disruption in areas that are important for sperm whales.
Nearly the entire important sperm whale habitat (Mississippi Canyon) is
included in the Gulf of Mexico Mitigation Area.
Kogia spp. are not depleted under the MMPA, nor are they
listed under the ESA. Although NMFS does not currently identify a trend
for Kogia spp. populations, recent survey effort and stranding data
show a simultaneous increase in at-sea abundance and strandings,
suggesting growing Kogia spp. abundance (NMFS, 2011; 2013a; Waring et
al., 2007; 2013).
The AFTT activities are not expected to occur in an area/
time of specific importance for reproductive, feeding, or other known
critical behaviors for sperm whales or Kogia spp. and there is no
designated critical habitat in the AFTT Study Area.
Consequently, the AFTT activities are not expected to adversely
impact rates of recruitment or survival of any of the analyzed stocks
of sperm whales, dwarf sperm whales, or pygmy sperm whales (Table 73
above in this section).
Dolphins and Small Whales
In Table 74 below, for dolphins and small whales, we indicate the
total annual mortality, Level A and Level B harassment, and a number
indicating the instances of total take as a percentage of abundance.
Overall, takes from Level A harassment (PTS and Tissue Damage) account
for less than one percent of all total takes.

[[Page 11078]]

[GRAPHIC] [TIFF OMITTED] TP13MR18.026

[[Page 11079]]

individuals taken is smaller than the total estimated takes. In other
words, where the instances of take exceed 100 percent of the
population, repeated takes of some individuals are predicted. Generally
speaking, the higher the number of takes as compared to the population
abundance, the more repeated takes of individuals are likely, and the
higher the actual percentage of individuals in the population that are
likely taken at least once in a year. We look at this comparative
metric to give us a relative sense across species/stocks of where
larger portions of the stocks are being taken by Navy activities and
where there is a higher likelihood that the same individuals are being
taken across multiple days and where that number of days might be
higher. In the ocean, the use of sonar and other active acoustic
sources is often transient and is unlikely to repeatedly expose the
same individual animals within a short period, for example within one
specific exercise, however, some repeated exposures across different
activities could occur over the year, especially where events occur in
the generally the same area with more resident species. In short, we
expect that the total anticipated takes represent exposures of a
smaller number of individuals of which some were exposed multiple
times, but based on the nature of the Navy activities and the movement
patterns of marine mammals, it is unlikely any particular subset would
be taken over more than a few sequential days--i.e., where repeated
takes of individuals are likely to occur, they are more likely to
result from non-sequential exposures from different activities and
marine mammals are not predicted to be taken for more than a few days
in a row, at most. As described elsewhere, the nature of the majority
of the exposures would be expected to be of a less severe nature and
based on the numbers it is still likely that any individual exposed
multiple times is still only taken on a small percentage of the days of
the year. For example, for Choctawatchee Bay stock of bottlenose
dolphins, takes in the US EEZ are notably higher as compared to the
abundance in the US EEZ, suggesting that on average, individuals might
be taken an average of 10 times per year based on the percentages
above. The greater likelihood is that not every individual is taken, or
perhaps a smaller subset is taken with a slightly higher average and
larger variability of highs and lows, but still with no reason to think
that any individuals would be taken every day for months out of the
year, much less on sequential days. For other stocks, Fraser's dolphin
for example (Western North Atlantic stock), takes in the US EEZ are
notably higher as compared to the abundance in the US EEZ, suggesting
that on average, the 2-3 percent of the individuals that comprise the
abundance in the US EEZ might be taken an average of 10 times per year
based on the percentages above--but when takes are considered across
the whole study area, they equate to only about 32 percent of the
abundance, suggesting that no more than a third of the individuals
would be taken and those that are would be only once a year on average.
Most Level B harassments to dolphins and small whales from hull-
mounted sonar (MF1) in the AFTT Study Area would result from received
levels between 160 and 166 dB SPL (66 percent). Therefore, the majority
of Level B takes are expected to be in the form of milder responses
(i.e., lower-level exposures that still rise to the level of take, but
would likely be less severe in the range of responses that qualify as
take) of a generally shorter duration. As mentioned earlier in this
section, we anticipate more severe effects from takes when animals are
exposed to higher received levels. Occasional milder behavioral
reactions are unlikely to cause long-term consequences for individual
animals or populations, and even if some smaller subset of the takes
are in the form of a longer (several hours or a day) and more moderate
response, because they are not expected to be repeated over sequential
multiple days, impacts to individual fitness are not anticipated.
Research and observations show that if delphinids 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.
Delphinids may not react at all until the sound source is approaching
within a few hundred meters to within a few kilometers depending on the
environmental conditions and species. Delphinids that are exposed to
activities that involve the use of sonar and other active acoustic
sources may alert, ignore the stimulus, change their behaviors or
vocalizations, avoid the sound source by swimming away or diving, or be
attracted to the sound source (Richardson, 1995; Nowacek, 2007;
Southall et al., 2007; Finneran and Jenkins, 2012).
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.
Of the BIAs for small and resident populations of bottlenose
dolphin (Gulf of Mexico and East Coast), these identified areas are
within bays and estuaries where the Navy does not use explosives and
conduct limited activities by sonar and other transducers. For example,
in the Northern North Carolina Estuarine dolphins (BIA), one-third of
the takes are from sub-navigation and ship object avoidance (less
impactful sonar activity) events which occur in/out of Chesapeake Bay.
This area is on the northern border of this BIA which further reduces
the possibility of modeled takes that would result in significant
impacts. The other two-thirds of the takes for the Northern North
Carolina Estuarine dolphins are from Civilian Port Defense which would
occur at most only once in five years in the vicinity of that BIA.
Similarly, for the Indian River Lagoon Estuarine system bottlenose
dolphins (BIA), all the level B takes are from also from the less
impactful sonar activity of sub-navigation and ship object avoidance
and are events of short duration (approx. 30 minutes). Two small and
resident populations of bottlenose dolphin BIAs (Northern North
Carolina Estuarine System and Southern North Carolina Estuarine System)
may be impacted during pile driving activities for the Elevated
Causeway System at Marine Corps Base Camp Lejeune, North Carolina;
however, only one modeled take of a Northern North Carolina Estuarine
System bottlenose dolphin is predicted. There are no modeled takes from
any activities to Southern North Carolina Estuarine System bottlenose
dolphins (BIA) and only one modeled take to Mississippi Sound BIA from
sonar. No takes are predicted from airguns for any bottlenose dolphin
BIAs. Therefore, impacts are expected to be short-term and minor by
Level B harassment and mostly all behavioral takes. Abandonment of the
area would not be anticipated to the small and resident bottlenose
dolphin populations (BIAs) from the Navy's training and testing
activities.
One of these BIAs, the bottlenose dolphin of Barataria Bay,
Louisiana (and showing persistent impacts by the Cetacean UME in the
Northern Gulf of Mexico) were recently fitted with satellite-linked
transmitters, showing that most dolphins remained within the bay, while
those that entered nearshore coastal waters remained within 1.75 km
(Wells et al., 2017). While the Navy's activities are very limited in
this type of habitat, the Navy is not conducting

[[Page 11080]]

training or testing where Barataria Bay dolphins inhabit and therefore
no takes will occur to this stock.
In summary and as described above, the following factors primarily
support our preliminary determination that the impacts resulting from
Navy's activities are not expected to adversely affect dolphins and
small whales taken through effects on annual rates of recruitment or
survival:
As described in the ``Serious Injury or Mortality''
section (Table 71), up to nine serious injuries or mortalities over
five years are proposed for authorization for four species of dolphins
(short-beaked common dolphin, Atlantic white-sided dolphin, pantropical
spotted dolphin, and spinner dolphins). However, the proposed serious
injury or mortality for these species falls below the insignificance
threshold, and, therefore, we consider the addition an insignificant
incremental increase to human-caused mortality.
As described above, any PTS that may occur is expected to
be of a relatively smaller degree because of the unlikelihood that
animals would be close enough for a long enough amount of time to incur
more severe PTS (for sonar) and the anticipated effectiveness of
mitigation in preventing very close exposures for explosives.
While the majority of takes are caused by exposure during
ASW activities, the impacts from these exposures are not expected to
have either significant or long-term effects because (and as discussed
above):
[cir] ASW activities typically involve fast-moving assets (relative
to marine mammal swim speeds) and individuals are not expected to be
exposed either for long periods within a day or over many sequential
days.
[cir] As discussed, the majority of the harassment takes result
from hull-mounted sonar during MTEs. When distance cut offs are applied
for odontecetes, this means that all of the takes from hull-mounted
(MF1) sonar result from above exposure 160 dB. However, the majority
(e.g., 66 percent) of the takes results from exposures below 166 dB.
The majority of the takes have a relatively lower likelihood to have
severe impacts.
For the total instances of all of the different types of
takes, the numbers indicating the instances of total take as a
percentage of abundance are between 1 and 984 percent over the whole
Navy Study Area (with more than half the stocks being under 100), and
between 1 and 1053 percent in the US EEZ alone (Table 74). While these
percentages may seem high, when spread over the entire year and a very
large range, the scale of the effects are such that over the whole Navy
Study area, individuals are taken an average of 0 or 1-10 times per
year (with the majority closer to 1), and some subset of these
individuals in the US EEZ are taken an average of 1-11 times (based on
the percentages above, respectively, but with some taken more or less).
These averages allow that perhaps a smaller subset is taken with a
slightly higher average and larger variability of highs and lows, but
still with no reason to think that any individuals would be taken every
day for weeks or months out of the year, much less on sequential days.
These behavioral takes are not all expected to be of particularly high
intensity and nor are they likely to occur over sequential days, which
suggests that the overall scale of impacts for any individual would be
relatively low.
Of the BIAs for small and resident populations of
bottlenose dolphin BIAs (Gulf of Mexico and East Coast), these
identified areas are within bays and estuaries where the Navy does not
use explosives nor generally train/test with sonar and other
transducers. Therefore, impacts are short-term and minor mostly due to
Level B harassment behavioral takes. Significant impacts are not
anticipated to the small and resident bottlenose dolphin populations
(BIAs) from the Navy's training and testing activities.
No takes are anticipated or authorized for the Barataria
Bay dolphins (one of the BIAs for bottlenose dolphin and showing
persistent impacts by the Cetacean UME in the Northern Gulf of Mexico).
The AFTT activities are not expected to occur routinely in
an area/time of specific importance for reproductive, feeding, or other
known critical behaviors for delphinids. Stocks of delphinid species
found in the AFTT Study Area are not depleted under the MMPA, nor are
they listed under the ESA.
Consequently, the activities are not expected to adversely impact
rates of recruitment or survival of any of the stocks of analyzed
delphinid species (Table 74, above in this section).

Porpoises

In Table 75, below for porpoises, we indicate the total annual
mortality, Level A and Level B harassment, and a number indicating the
instances of total take as a percentage of abundance. Overall, takes
from Level A harassment (PTS and Tissue Damage) account for less than
one percent of all total takes.
[GRAPHIC] [TIFF OMITTED] TP13MR18.027

Nearly 100 percent of takes annually for harbor porpoises are from
Level B harassment either behavioral or TTS (less than 1 percent for
PTS) (Table 75 above). No mortalities are anticipated. As noted
previously, the estimated takes

[[Page 11081]]

represent instances of take, not the number of individuals taken, and
in almost all cases--some individuals are expected to be taken more
than one time, which means that the number of individuals taken is
smaller than the total estimated takes. In other words, where the
instances of take exceed 100 percent of the population, repeated takes
of some individuals are predicted. Generally speaking, the higher the
number of takes as compared to the population abundance, the more
repeated takes of individuals are likely, and the higher the actual
percentage of individuals in the population that are likely taken at
least once in a year. We look at this comparative metric to give us a
relative sense across species/stocks of where larger portions of the
stocks are being taken by Navy activities and where there is a higher
likelihood that the same individuals are being taken across multiple
days and where that number of days might be higher. In the ocean, the
use of sonar and other active acoustic sources is often transient and
is unlikely to repeatedly expose the same individual animals within a
short period, for example within one specific exercise, however, some
repeated exposures across different activities could occur over the
year, especially where events occur in the generally the same area with
more resident species. In short, we expect that the total anticipated
takes represent exposures of a smaller number of individuals of which
some were exposed multiple times, but based on the nature of the Navy
activities and the movement patterns of marine mammals, it is unlikely
any particular subset would be taken over more than a few sequential
days--i.e., where repeated takes of individuals are likely to occur,
they are more likely to result from non-sequential exposures from
different activities and marine mammals are not predicted to be taken
for more than a few days in a row, at most. As described elsewhere, the
nature of the majority of the exposures would be expected to be of a
less severe nature and based on the numbers it is still likely that any
individual exposed multiple times is still only taken on a small
percentage of the days of the year. For harbor porpoise, takes in the
US EEZ are notably higher as compared to the abundance in the US EEZ,
suggesting that on average, the 8 percent of the individuals that
comprise the abundance in the US EEZ might be taken an average of 10
times per year based on the percentages above--but when takes are
considered across the whole Study area, they equate to only about 85
percent of the abundance, suggesting that not all individuals will be
taken every year, and those that are would be only once a year on
average.
The greater likelihood is that not every individual is taken or
perhaps a smaller subset is taken with a slightly higher average and
larger variability of highs and lows, but still with no reason to think
that any individuals would be taken every day for months out of the
year, much less on sequential days.
Most Level B harassments to harbor porpoise from hull-mounted sonar
(MF1) in the AFTT Study Area would result from received levels between
154 and 160 dB SPL (59 percent). Therefore, the majority of Level B
takes are expected to be in the form of milder responses (i.e., lower-
level exposures that still rise to the level of take, but would likely
be less severe in the range of responses that qualify as take) of a
generally shorter duration. As mentioned earlier in this section, we
anticipate more severe effects from takes when animals are exposed to
higher received levels. Occasional milder behavioral reactions are
unlikely to cause long-term consequences for individual animals or
populations, and even if some smaller subset of the takes are in the
form of a longer (several hours or a day) and more moderate response,
because they are not expected to be repeated over sequential multiple
days, impacts to individual fitness are not anticipated.
The number of harbor porpoise behaviorally harassed by exposure to
LFAS/MFAS/HFAS in the AFTT Study Area is generally higher than the
other species. Of note, harbor porpoises have been shown to be
particularly sensitive to sound and therefore have been assigned a
lower harassment threshold, i.e., a more distant distance cutoff (40 km
for high source level, 20 km for moderate source level). This means
that many of the authorized takes are expected to result from lower-
level exposures, but we also note the growing literature to support the
fact that marine mammals differentiate sources of the same level
emanating from different distances, and exposures from more distant
sources are likely comparatively less impactful. 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.
A small and resident population area for harbor porpoises
identified by LaBrecque et al. (2015a, 2015b) overlaps a portion of the
northeast corner of the Northeast Range Complexes. Navy testing
activities that use sonar and other transducers could occur year round
within the Northeast Range Complexes. The harbor porpoise BIA is
included in the Gulf of Maine Mitigation Area where the Navy will not
plan MTEs (Composite Training Unit or Fleet/Sustainment Exercises) and
will not conduct more than 200 hrs of hull-mounted MFAS per year. As
discussed above, harbor porpoise reactions to sonar could be
significant in some cases. Due to the limited overlap of the identified
harbor porpoise area and the Northeast Range Complexes, only a subset
of estimated behavioral reactions would occur within the identified
harbor porpoise small and resident population area. It is unlikely that
these behavioral reactions would have significant impacts on the
natural behavior of harbor porpoises or cause abandonment of the harbor
porpoise small and resident population area identified by LaBrecque et
al. (2015a, 2015b). Due to the intermittent nature of explosive
activities that could take place within the identified harbor porpoise
area, significant impacts to natural behaviors within or abandonment of
the small and resident population area for harbor porpoises are not
anticipated.
Animals that 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). 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.
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 species is wary of human activity
and will display profound avoidance behavior for anthropogenic sound

[[Page 11082]]

sources in many situations at levels down to 120 dB re 1 [micro]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 Thorpe, 1990). Harbor porpoises may
startle and temporarily leave the immediate area of the training or
testing until after the event ends.
ASW training activities using hull mounted sonar proposed for the
AFTT Study Area generally last for only a few hours. Some ASW exercises
can generally last for 2-10 days, or as much as 21 days for an MTE-
Large Integrated ASW (see Table 1.3-1 of the Navy's rulemaking and LOA
application). For these multi-day exercises there will be extended
intervals of non-activity in between active sonar periods. In addition,
the Navy does not typically conduct ASW activities in the same
locations. Given the average length of ASW events (times of continuous
sonar use) and typical vessel speed, combined with the fact that the
majority of porpoises in the AFTT Study Area would not likely remain in
an area for successive days, it is unlikely that an animal would be
exposed to active sonar 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.
In summary and as described above, the following factors primarily
support our preliminary determination that the impacts resulting from
Navy's activities are not expected to adversely affect harbor porpoises
taken through effects on annual rates of recruitment or survival:
No mortalities of harbor porpoises are proposed for
authorization or anticipated to occur.
As described above, any PTS that may occur is expected to
be of a relatively smaller degree because of the unlikelihood that
harbor porpoise would be close enough for a long enough amount of time
to incur more severe PTS (for sonar) and the anticipated effectiveness
of mitigation in preventing very close exposures for explosives.
While the majority of takes are caused by exposure during
ASW activities, the impacts from these exposures are not expected to
have either significant or long-term effects because (and as discussed
above):
[cir] ASW activities typically involve fast-moving assets (relative
to marine mammal swim speeds) and individuals are not expected to be
exposed either for long periods within a day or over many sequential
days.
[cir] As discussed, the majority of the harassment takes result
from hull-mounted sonar during MTEs. When distance cut offs are applied
for harbor porpoise, this means that all of the takes from hull-mounted
sonar (MF1) result from above exposure 154 dB. However, the majority
(e.g., 59 percent) of the takes results from exposures below 160 dB.
The majority of the takes have a relatively lower likelihood to have
severe impacts.
For the total instances of all of the different types of
takes, the number indicating the instances of total take as a
percentage of abundance is 994 percent over the whole Navy Study Area,
and 85 percent in the US EEZ alone (Table 75). While these percentages
may seem high, when spread over the entire year and a very large range,
the scale of the effects are such that over the whole Navy Study area,
individuals are taken an average of 0 or 1 times per year, and the 8
percent of these individuals in the US EEZ are taken an average of 10
times (based on the percentages above in Table 75, respectively, but
with some taken more or less). These averages allow that perhaps a
smaller subset is taken with a slightly higher average and larger
variability of highs and lows, but still with no reason to think that
any individuals would be taken every day for weeks or months out of the
year, much less on sequential days. These behavioral takes are not all
expected to be of particularly high intensity and nor are they likely
to occur over sequential days, which suggests that the overall scale of
impacts for any individual would be relatively low.
The AFTT activities could occur in areas important for
harbor porpoises; however, due to the geographic dispersion and limited
duration of those activities, they are unlikely to have a significant
impact on feeding, reproduction, or other known critical behaviors.
Harbor porpoise found in the AFTT Study Area are not
depleted under the MMPA, nor are they listed under the ESA.
The harbor porpoise BIA is included in the Gulf of Maine
Mitigation Area where the Navy will not plan MTEs (Composite Training
Unit or Fleet/Sustainment Exercises) and will not conduct more than 200
hrs of hull-mounted MFAS per year.
Consequently, the activities are not expected to adversely impact
rates of recruitment or survival of any of the analyzed harbor porpoise
stocks (Table 65).
Beaked Whales
In Table 76 below, for beaked whales, we indicate the total annual
mortality, Level A and Level B harassment, and a number indicating the
instances of total take as a percentage of abundance. Overall, takes
from Level A harassment (PTS and Tissue Damage) account for less than
one percent of all total takes.

[[Page 11083]]

[GRAPHIC] [TIFF OMITTED] TP13MR18.028

As noted previously, the estimated takes represent instances of
take, not the number of individuals taken, and in almost all cases--
some individuals are expected to be taken more than one time, which
means that the number of individuals taken is smaller than the total
estimated takes. In other words, where the instances of take exceed 100
percent of the population, repeated takes of some individuals are
predicted. Generally speaking, the higher the number of takes as
compared to the population abundance, the more repeated takes of
individuals are likely, and the higher the actual percentage of
individuals in the population that are likely taken at least once in a
year. We look at this comparative metric to give us a relative sense
across species/stocks of where larger portions of the stocks are being
taken by Navy activities and where there is a higher likelihood that
the same individuals are being taken across multiple days and where
that number of days might be higher. In the ocean, the use of sonar and
other active acoustic sources is often transient and is unlikely to
repeatedly expose the same individual animals within a short period,
for example within one specific exercise, however, some repeated
exposures across different activities could occur over the year,
especially where events occur in the generally the same area with more
resident species. In short, we expect that the total anticipated takes
represent exposures of a smaller number of individuals of which some
were exposed multiple times, but based on the nature of the Navy
activities and the movement patterns of marine mammals, it is unlikely
any particular subset would be taken over more than a few sequential
days--i.e., where repeated takes of individuals are likely to occur,
they are more likely to result from non-sequential exposures from
different activities and marine mammals are not predicted to be taken
for more than a few days in a row, at most. As described elsewhere, the
nature of the majority of the exposures would be expected to be of a
less severe nature and based on the numbers it is still likely that any
individual exposed multiple times is still only taken on a small
percentage of the days of the year. For the Atlantic stocks of beaked
whales, takes in the US EEZ are notably higher as compared to the
abundance in the US EEZ, suggesting that on average, for the 10 percent
or less of the individuals that comprise the abundance in the US EEZ,
they might be taken an average of 16-19 times per year based on the
percentages above--but when takes are considered across the whole Study
area, they equate to only about 170-308 percent of the abundance,
suggesting that across the Study Area, individuals would be taken an
average of 1-3 times per year. The greater likelihood is that not every
individual is taken, or perhaps a smaller subset is taken with a
slightly higher average and larger variability of highs and lows, but
still with no reason to think that any individuals would be taken every
day for weeks or months out of the year, much less on sequential days.
Most Level B harassments to beaked whales from hull-mounted sonar
(MF1) in the AFTT Study Area would result from received levels between
148 and 160 dB SPL (91 percent). Therefore, the majority of Level B
takes are expected to be in the form of milder responses (i.e., lower-
level exposures that still rise to the level of take, but would likely
be less severe in the range of responses that qualify as take) of a
generally shorter duration. As mentioned earlier in this section, we
anticipate more severe effects from takes when animals are exposed to
higher received levels. Occasional milder behavioral reactions are
unlikely to cause long-term consequences for individual animals or
populations, and even if some smaller subset of the takes are in the
form of a longer (several hours or a day) and more moderate response,
because they are not expected to be repeated over sequential multiple
days, impacts to individual fitness are not anticipated.
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, i.e., a more distant distance cutoff (50
km for high source level, 25 km for moderate source level). This means
that many of the authorized takes are expected to result from lower-
level exposures, but we also note the growing literature to support the
fact that marine mammals differentiate sources of the same level
emanating from different distances, and exposures from more distant
sources are likely comparatively less impactful.
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; Finneran and Jenkins, 2012). Research has
also shown that beaked whales are especially sensitive to the presence
of human activity (Tyack et al., 2011; Pirotta et al.,

[[Page 11084]]

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 (e.g., Northern bottlenose whale) 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 MFAS/HFAS.
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 MFAS 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 [micro]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 [micro]Pa (Tyack et al. 2011). Stimpert et al. (2014)
tagged a Baird's beaked whale, which was subsequently exposed to
simulated MFAS. Changes in the animal's dive behavior and locomotion
were observed when received level reached 127 dB re 1[mu]Pa. However,
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 [micro]Pa while the animals were at depth
during their dives. And 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, 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.
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 training or testing activities would
generally not have long-term consequences for individuals or
populations.
NMFS does not expect strandings, serious injury, or mortality of
beaked whales to occur as a result of training activities. Stranding
events coincident with Navy MFAS use in which exposure to sonar is
believed to have been a contributing factor were detailed in the
Stranding and Mortality section of this proposed rule. However, for
some of these stranding events, a causal relationship between sonar
exposure and the stranding could not be clearly established (Cox et
al., 2006). In other instances, sonar was considered only one of
several factors that, in their aggregate, may have contributed to the
stranding event (Freitas, 2004; Cox et al., 2006). Because of the
association between tactical MFAS 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 measures
intended to more broadly minimize impacts to marine mammals, the
reporting requirements set forth in this rule ensure that NMFS is
notified if a stranded marine mammal is found (see General Notification
of Injured or Dead Marine Mammals in the regulatory text below).
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.
In summary and as described above, the following factors primarily
support our preliminary determination that the impacts resulting from
the Navy's activities are not expected to adversely affect beaked
whales taken through effects on annual rates of recruitment or
survival:
No mortalities of beaked whales are proposed for
authorization or anticipated to occur.

[[Page 11085]]

As described above, any PTS that may occur is expected to
be of a relatively smaller degree because of the unlikelihood that
animals would be close enough for a long enough amount of time to incur
more severe PTS (for sonar) and the anticipated effectiveness of
mitigation in preventing very close exposures for explosives.
While the majority of takes are caused by exposure during
ASW activities the impacts from these exposures are not expected to
have either significant or long-term effects because (and as discussed
above):
[cir] ASW activities typically involve fast-moving assets (relative
to marine mammals swim speeds) and individuals are not expected to be
exposed either for long periods within a day or over many sequential
days.
[cir] As discussed, the majority of the harassment takes result
from hull-mounted sonar during MTEs. When distance cut offs are applied
for beaked whales, this means that all of the takes from hull-mounted
sonar (MF1) result from above exposure 148 dB. However, the majority
(e.g., 91 percent) of the takes results from exposures below 160 dB.
The majority of the takes have a relatively lower likelihood to have
severe impacts.
For the total instances of all of the different types of
takes of the three Gulf of Mexico stocks of beaked whales, the numbers
indicating the instances of total take as a percentage of abundance are
between 148 and 155 (Table 76). When spread over the entire year and a
very large range, the scale of the effects are such that individuals
are taken an average of 1-2 times per year (based on the percentages
above, respectively, but with some taken more or less). These averages
allow that perhaps a smaller subset is taken with a slightly higher
average and larger variability of highs and lows, but still with no
reason to think that any individuals would be taken for more than
several days out of the year, much less on sequential days. These
behavioral takes are not all expected to be of particularly high
intensity and nor are they likely to occur over sequential days, which
suggests that the overall scale of impacts for any individual would be
relatively low.
For the total instances of all of the different types of
takes of the Atlantic stocks of beaked whales, the numbers indicating
the instances of total take as a percentage of abundance are between
170 and 308 percent over the whole Navy Study Area, and between 1658
and 1910 percent in the US EEZ alone (Table 76). While these
percentages may seem high, when spread over the entire year and a very
large range, the scale of the effects are such that over the whole Navy
Study area, individuals are taken an average of 1-3 times per year, and
the 10 percent or fewer of these individuals in the US EEZ are taken an
average of 16-19 times (based on the percentages above, respectively,
but with some taken more or less). These averages allow that perhaps a
smaller subset is taken with a slightly higher average and larger
variability of highs and lows, but still with no reason to think that
any individuals would be taken every day for weeks or months out of the
year, much less on sequential days. These behavioral takes are not all
expected to be of particularly high intensity and nor are they likely
to occur over sequential days, which suggests that the overall scale of
impacts for any individual would be relatively low.
The AFTT activities are not expected to occur in an area/
time of specific importance for reproductive, feeding, or other known
critical behaviors for beaked whales.
Beaked whales found in the AFTT Study Area are not
depleted under the MMPA, nor are they listed under the ESA.
Consequently, the activities are not expected to adversely impact
rates of recruitment or survival of any of the beaked whale stocks
analyzed (Table 76 above in this section).
Pinnipeds
In Table 77 below, for pinnipeds, we indicate the total annual
mortality, Level A and Level B harassment, and a number indicating the
instances of total take as a percentage of abundance. Overall, takes
from Level A harassment (PTS and Tissue Damage) account for less than
one percent of all total takes.
[GRAPHIC] [TIFF OMITTED] TP13MR18.029

[[Page 11086]]

look at this comparative metric to give us a relative sense across
species/stocks of where larger portions of the stocks are being taken
by Navy activities and where there is a higher likelihood that the same
individuals are being taken across multiple days and where that number
of days might be higher. In the ocean, the use of sonar and other
active acoustic sources is often transient and is unlikely to
repeatedly expose the same individual animals within a short period,
for example within one specific exercise, however, some repeated
exposures across different activities could occur over the year,
especially where events occur in generally the same area with more
resident species. In short, we expect that the total anticipated takes
represent exposures of a smaller number of individuals of which some
were exposed multiple times, but based on the nature of the Navy
activities and the movement patterns of marine mammals, it is unlikely
any particular subset would be taken over more than a few sequential
days--i.e., where repeated takes of individuals are likely to occur,
they are more likely to result from non-sequential exposures from
different activities and marine mammals are not predicted to be taken
for more than a few days in a row, at most. As described elsewhere, the
nature of the majority of the exposures would be expected to be of a
less severe nature and based on the numbers it is still likely that any
individual exposed multiple times is still only taken on a small
percentage of the days of the year. The greater likelihood is that not
every individual is taken, or perhaps a smaller subset is taken with a
slightly higher average and larger variability of highs and lows, but
still with no reason to think that any individuals would be taken every
day for months out of the year, much less on sequential days.
Most Level B harassments to beaked whales from hull-mounted sonar
(MF1) in the AFTT Study Area would result from received levels between
166 and 172 dB SPL (76 percent). Therefore, the majority of Level B
takes are expected to be in the form of milder responses (i.e., lower-
level exposures that still rise to the level of take, but would likely
be less severe in the range of responses that qualify as take) of a
generally shorter duration. As mentioned earlier in this section, we
anticipate more severe effects from takes when animals are exposed to
higher received levels. Occasional milder behavioral reactions are
unlikely to cause long-term consequences for individual animals or
populations, and even if some smaller subset of the takes are in the
form of a longer (several hours or a day) and more moderate response,
because they are not expected to be repeated over sequential multiple
days, impacts to individual fitness are not anticipated.
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 behaviors, or avoid the immediate area by swimming away or
diving. Effects on pinnipeds in the AFTT 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 an
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. Almost
all of the impacts estimated by the quantitative assessment are due to
navigation and object avoidance (detection) activities in navigation
lanes entering Groton, Connecticut. Navigation and object avoidance
(detection) activities normally involve a single ship or submarine
using a limited amount of sonar, therefore significant reactions are
unlikely, especially in phocid seals. If seals are exposed to sonar or
other active acoustic sources, they may react in various ways,
depending on their experience with the sound source and what activity
they are engaged in at the time of the acoustic exposure. Seals 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 behaviors,
or avoid the immediate area by swimming away or diving. The use of
sonar from navigation and object avoidance in Groton, Connecticut
likely exposes the same sub-population of animals multiple times
throughout the year. However, phocid seals are likely to only have
minor and short-term behavioral reactions to these types of activities
and significant behavioral reactions would not be expected in most
cases, and long-term consequences for individual seals from a single or
several impacts per year are unlikely.
Generally speaking, most pinniped stocks in the AFTT Study Area are
thought to be stable or increasing. In summary and as described above,
the following factors primarily support our preliminary determination
that the impacts resulting from the Navy's activities are not expected
to adversely affect pinnipeds taken through effects on annual rates of
recruitment or survival:

[[Page 11087]]

No mortalities of pinnipeds are proposed for authorization
or anticipated to occur.
As described above, any PTS that may occur is expected to
be of a relatively smaller degree because of the unlikelihood that
animals would be close enough for a long enough amount of time to incur
more severe PTS (for sonar) and the anticipated effectiveness of
mitigation in preventing very close exposures for explosives.
While the majority of takes are caused by exposure during
ASW activities, the impacts from these exposures are not expected to
have either significant or long-term effects because (and as discussed
above):
[cir] ASW activities typically involve fast-moving assets (relative
to marine mammals swim speeds) and individuals are not expected to be
exposed either for long periods within a day or over many sequential
days.
[cir] As discussed, the majority of the harassment takes result
from hull-mounted sonar during MTEs. When distance cut offs are applied
for pinnipeds, this means that all of the takes from hull-mounted sonar
(MF1) result from above exposure 166 dB. However, the majority (e.g.,
76 percent) of the takes results from exposures below 172 dB. The
majority of the takes have a relatively lower likelihood in have severe
impacts.
For the total instances of all of the different types of
takes of pinnipeds, the numbers indicating the instances of total take
as a percentage of abundance are between 34 and 225 (Table 77). When
spread over the entire year and a very large range, the scale of the
effects are such that individuals are taken an average of 0 to 1-2
times per year (based on the percentages above, respectively, but with
some taken more or less). These averages allow that perhaps a smaller
subset is taken with a slightly higher average and larger variability
of highs and lows, but still with no reason to think that any
individuals would be taken for more than several days out of the year,
much less on sequential days. These behavioral takes are not all
expected to be of particularly high intensity and nor are they likely
to occur over sequential days, which suggests that the overall scale of
impacts for any individual would be relatively low.
The AFTT activities are not expected to occur in an area/
time of specific importance for reproductive, feeding, or other known
critical behaviors for pinnipeds. Pinnipeds found in the AFTT Study
Area are not depleted under the MMPA, nor are they listed under the
ESA.
Consequently, the activities are not expected to adversely impact
rates of recruitment or survival of any of the analyzed stocks of
pinnipeds (Table 77 above in this section).

Preliminary Determination

Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the proposed monitoring and
mitigation measures, NMFS preliminarily finds that the total marine
mammal take from the proposed activity will have a negligible impact on
all affected marine mammal species or stocks.

Subsistence Harvest of Marine Mammals

There are no relevant subsistence uses of marine mammals implicated
by this action. Therefore, NMFS has preliminarily determined that the
total taking affecting 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 five marine mammal species under NMFS jurisdiction that
are listed As endangered or threatened under the ESA with confirmed or
possible occurrence in the AFTT Study Area: Blue whale, fin whale, sei
whale, sperm whale, and NARW. The Navy will consult with NMFS pursuant
to section 7 of the ESA, and NMFS will also consult internally on the
issuance of these regulations and LOAs under section 101(a)(5)(A) of
the MMPA for AFTT activities. Consultation will be concluded prior to a
determination on the issuance of the final rule and LOAs.

National Marine Sanctuaries Act

Some Navy activities may potentially affect resources within NMS.
Pursuant to Section 304(d) of the National Marine Sanctuaries Act
(NMSA), the Navy is consulting on activities as documented in the AFTT
DEIS/OEIS on potential impacts to sanctuary resources, including marine
mammals. The Navy will initiate consultation with NOAA's Office of
National Marine Sanctuaries pursuant to the requirements of the NMSA as
warranted by ongoing analysis of the activities and their effects on
sanctuary resources.

NEPA

To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must review its Proposed Activity (i.e., the issuance of an
incidental take authorization) with respect to potential impacts on the
human environment.
Accordingly, NMFS plans to adopt the Navy's EIS/OEIS for AFTT Study
Area provided our independent evaluation of the document finds that it
includes adequate information analyzing the effects on the human
environment of issuing regulations and LOAs. NMFS is a cooperating
agency on the Navy's DEIS.
The Navy's DEIS/OEIS was made available for public comment at
www.aftteis.com/ on June 30, 2017.
We will review all comments submitted in response to this document
prior to concluding our NEPA process or making a final decision on the
final rule and LOA requests.

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 LOA 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.

[[Page 11088]]

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: March 1, 2018.
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 follows:

Authority: 16 U.S.C. 1361 et seq., unless otherwise noted.

0
2. Revise subpart I of part 218 to read as follows:
Subpart I--Taking and Importing Marine Mammals; U.S. Navy's Atlantic
Fleet Training and Testing (AFTT)
Sec.
218.80 Specified activity and specified geographical region.
218.81 Effective dates.
218.82 Permissible methods of taking.
218.83 Prohibitions.
218.84 Mitigation requirements.
218.85 Requirements for monitoring and reporting.
218.86 Letters of Authorization.
218.87 Renewals and modifications of Letters of Authorization.
218.88-218.89 [Reserved]

Subpart I--Taking and Importing Marine Mammals; U.S. Navy's
Atlantic Fleet Training and Testing (AFTT)

Sec. 218.80 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 may be authorized in
Letters of Authorization (LOAs) only if it occurs within the Atlantic
Fleet Training and Testing (AFTT) Study Area, which includes areas of
the western Atlantic Ocean along the east coast of North America,
portions of the Caribbean Sea, and the Gulf of Mexico. The AFTT Study
Area begins at the mean high tide line along the U.S. coast and extends
east to the 45-degree west longitude line, north to the 65 degree north
latitude line, and south to approximately the 20-degree north latitude
line. The AFTT Study Area also includes Navy pierside locations, bays,
harbors, and inland waterways, and civilian ports where training and
testing occurs.
(c) The taking of marine mammals by the Navy is only authorized if
it occurs incidental to the Navy's conducting training and testing
activities. The Navy's use of sonar and other transducers, in-water
detonations, air guns, pile driving/extraction, and vessel movements
incidental to training and testing exercises may cause take by
harassment, serious injury or mortality as defined by the MMPA through
the various warfare mission areas in which the Navy would conduct
including amphibious warfare, anti-submarine warfare, expeditionary
warfare, surface warfare, mine warfare, and other activities (sonar and
other transducers ship shock trials, pile driving and removal
activities, airguns, vessel strike).

Sec. 218.81 Effective dates.

Regulations in this subpart are effective [date 30 days after date
of publication of the final rule in the Federal Register] through [date
5 years and 30 days after date of publication of the final rule in the
Federal Register].

Sec. 218.82 Permissible methods of taking.

Under LOAs issued pursuant to Sec. 216.106 of this chapter and
Sec. 218.87, the Holder of the LOAs (hereinafter ``Navy'') may
incidentally, but not intentionally, take marine mammals within the
area described in Sec. 218.80(b) by Level A harassment and Level B
harassment associated with the use of active sonar and other acoustic
sources and explosives as well as serious injury or mortality
associated with ship shock trials and vessel strikes provided the
activity is in compliance with all terms, conditions, and requirements
of these regulations in this subpart and the applicable LOAs.

Sec. 218.83 Prohibitions.

Notwithstanding takings contemplated in Sec. 218.82 and authorized
by LOAs issued under Sec. 216.106 of this chapter and Sec. 218.86, no
person in connection with the activities described in Sec. 218.82 may:
(a) Violate, or fail to comply with, the terms, conditions, and
requirements of this subpart or an LOA issued under Sec. 216.106 of
this chapter and Sec. 218.86;
(b) Take any marine mammal not specified in such LOAs;
(c) Take any marine mammal specified in such LOAs in any manner
other than as specified;
(d) Take a marine mammal specified in such LOAs if NMFS determines
such taking results in more than a negligible impact on the species or
stocks of such marine mammal; or

Sec. 218.84 Mitigation requirements.

When conducting the activities identified in Sec. 218.80(c), the
mitigation measures contained in any LOAs issued under Sec. 216.106 of
this chapter and Sec. 218.86 must be implemented. These mitigation
measures shall include the following requirements, but are not limited
to:
(a) Procedural Mitigation. Procedural mitigation is mitigation that
the Navy shall implement whenever and wherever an applicable training
or testing activity takes place within the AFTT Study Area for each
applicable activity category or stressor category and includes acoustic
stressors (i.e., active sonar, air guns, pile driving, weapons firing
noise), explosive stressors (i.e., sonobuoys, torpedoes, medium-caliber
and large-caliber projectiles, missiles and rockets, bombs, sinking
exercises, mines, anti-swimmer grenades, line charge testing and ship
shock trials), and physical disturbance and strike stressors (i.e.,
vessel movement, towed in-water devices, small-, medium-, and large-
caliber non-explosive practice munitions, non-explosive missiles and
rockets, non-explosive bombs and mine shapes).
(1) Environmental Awareness and Education. Appropriate personnel
involved in mitigation and training or testing activity reporting under
the Proposed Activity shall complete one or more modules of the U.S
Navy Afloat Environmental Compliance Training Series, as identified in
their career path training plan. Modules include: Introduction to the
U.S. Navy Afloat Environmental Compliance Training Series, Marine
Species Awareness Training, U.S. Navy Protective Measures Assessment
Protocol, and U.S. Navy Sonar Positional Reporting System and Marine
Mammal Incident Reporting.
(2) Active Sonar. Active sonar includes low-frequency active sonar,
mid-frequency active sonar, and high-frequency active sonar. For
vessel-based active sonar activities, mitigation applies only to
sources that are positively controlled and deployed from manned surface
vessels (e.g., sonar sources towed from manned surface platforms). For
aircraft-based active sonar activities, mitigation applies to sources
that are positively controlled and deployed from manned aircraft that

[[Page 11089]]

do not operate at high altitudes (e.g., rotary-wing aircraft).
Mitigation does not apply to active sonar sources deployed from
unmanned aircraft or aircraft operating at high altitudes (e.g.,
maritime patrol aircraft).
(i) Number of Lookouts and Observation Platform--(A) Hull-mounted
sources: Two lookouts at the forward part of the ship for platforms
without space or manning restrictions while underway; One lookout at
the forward part of a small boat or ship for platforms with space or
manning restrictions while underway; One lookout for platforms using
active sonar while moored or at anchor (including pierside); and Four
lookouts for pierside sonar testing activities at Port Canaveral,
Florida and Kings Bay, Georgia.
(B) Non-hull mounted sources: One lookout on the ship or aircraft
conducting the activity.
(ii) Mitigation Zone and Requirements--(A) Prior to the start of
the activity the Navy shall observe for floating vegetation and marine
mammals; if resource is observed, the Navy shall not commence use of
active sonar.
(B) During low-frequency active sonar at or above 200 decibel (dB)
and hull-mounted mid-frequency active sonar the Navy shall observe for
marine mammals and power down active sonar transmission by 6 dB if
resource is observed within 1,000 yards (yd) of the sonar source; power
down by an additional 4 dB (10 dB total) if resource is observed within
500 yd of the sonar source; and cease transmission if resource is
observed within 200 yd of the sonar source.
(C) During low-frequency active sonar below 200 dB, mid-frequency
active sonar sources that are not hull mounted, and high-frequency
active sonar the Navy shall observe for marine mammals and cease active
sonar transmission if resource is observed within 200 yd of the sonar
source.
(D) To allow a sighted marine mammal to leave the mitigation zone,
the Navy shall not recommence active sonar transmission until one of
the recommencement conditions has been met: The animal is observed
exiting the mitigation zone; the animal is thought to have exited the
mitigation zone based on a determination of its course, speed, and
movement relative to the sonar source; the mitigation zone has been
clear from any additional sightings for 10 min for aircraft-deployed
sonar sources or 30 min for vessel-deployed sonar sources; for mobile
activities, the active sonar source has transited a distance equal to
double that of the mitigation zone size beyond the location of the last
sighting; or for activities using hull-mounted sonar, the ship
concludes that dolphins are deliberately closing in on the ship to ride
the ship's bow wave, and are therefore out of the main transmission
axis of the sonar (and there are no other marine mammal sightings
within the mitigation zone).
(E) The Navy shall notify the Port Authority prior to the
commencement of pierside sonar testing activities at Port Canaveral,
Florida and Kings Bay, Georgia. At these locations, the Navy shall
conduct active sonar activities during daylight hours to ensure
adequate sightability of manatees, and shall equip Lookouts with
polarized sunglasses. After completion of pierside sonar testing
activities at Port Canaveral and Kings Bay, the Navy shall continue to
observe for marine mammals for 30 min within the mitigation zone. The
Navy shall implement a reduction of at least 36 dB from full power for
mid-frequency active sonar transmissions at Kings Bay. The Navy shall
communicate sightings of manatees made during or after pierside sonar
testing activities at Kings Bay to the Georgia Department of Natural
Resources sightings hotline, Base Natural Resources Manager, and Port
Operations. Communications shall include information on the time and
location of a sighting, the number and size of animals sighted, a
description of any research tags (if present), and the animal's
direction of travel. Port Operations shall disseminate the sightings
information to other vessels operating near the sighting and shall keep
logs of all manatee sightings.
(3) Air Guns. (i) Number of Lookouts and Observation Platform--One
lookout positioned on a ship or pierside.
(ii) Mitigation Zone and Requirements--150 yd around the air gun.
(A) Prior to the start of the activity (e.g., when maneuvering on
station), the Navy shall observe for floating vegetation, and marine
mammals; if resource is observed, the Navy shall not commence use of
air guns.
(B) During the activity, the Navy shall observe for marine mammals;
if resource is observed, the Navy shall cease use of air guns.
(C) To allow a sighted marine mammal to leave the mitigation zone,
the Navy shall not recommence the use of air guns until one of the
recommencement conditions has been met: The animal is observed exiting
the mitigation zone; the animal is thought to have exited the
mitigation zone based on a determination of its course, speed, and
movement relative to the air gun; the mitigation zone has been clear
from any additional sightings for 30 min; or for mo108bile activities,
the air gun has transited a distance equal to double that of the
mitigation zone size beyond the location of the last sighting.
(4) Pile Driving. Pile driving and pile extraction sound during
Elevated Causeway System training.
(i) Number of Lookouts and Observation Platform--One lookout
positioned on the shore, the elevated causeway, or a small boat.
(ii) Mitigation Zone and Requirements--100 yd around the pile
driver.
(A) Thirty minutes prior to the start of the activity, the Navy
shall observe for floating vegetation and marine mammals; if resource
is observed, the Navy shall not commence impact pile driving or
vibratory pile extraction.
(B) During the activity, the Navy shall observe for marine mammals;
if resource is observed, the Navy shall cease impact pile driving or
vibratory pile extraction.
(C) To allow a sighted marine mammal to leave the mitigation zone,
the Navy shall not recommence pile driving until one of the
recommencement conditions has been met: The animal is observed exiting
the mitigation zone; the animal is thought to have exited the
mitigation zone based on a determination of its course, speed, and
movement relative to the pile driving location; or the mitigation zone
has been clear from any additional sightings for 30 min.
(D) In the Navy Cherry Point Range Complex, the Navy shall maintain
a log detailing any sightings and injuries to manatees during pile
driving. If a manatee was sighted during the activity, upon completion
of the activity, the Navy project manager or civilian equivalent shall
prepare a report that summarizes all information on manatees
encountered and submit the report to the USFWS, Raleigh Field Office.
The Navy shall report any injury of a manatee to the USFWS, NMFS, and
the North Carolina Wildlife Resources Commission.
(5) Weapons Firing Noise. Weapons firing noise associated with
large-caliber gunnery activities.
(i) Number of Lookouts and Observation Platform--One lookout shall
be positioned on the ship conducting the firing. Depending on the
activity, the lookout could be the same as the one described in
Explosive Medium-Caliber and Large-Caliber Projectiles or in Small-,
Medium-and Large-Caliber Non-Explosive Practice Munitions.
(ii) Mitigation Zone and Requirements--Thirty degrees on either
side of the firing line out to 70 yd from the muzzle of the weapon
being fired.

[[Page 11090]]

(A) Prior to the start of the activity, the Navy shall observe for
floating vegetation, and marine mammals; if resource is observed, the
Navy shall not commence weapons firing.
(B) During the activity, the Navy shall observe for marine mammals;
if resource is observed, the Navy shall cease weapons firing.
(C) To allow a sighted marine mammal to leave the mitigation zone,
the Navy shall not recommence weapons firing until one of the
recommencement conditions has been met: The animal is observed exiting
the mitigation zone; the animal is thought to have exited the
mitigation zone based on a determination of its course, speed, and
movement relative to the firing ship; the mitigation zone has been
clear from any additional sightings for 30 min; or for mobile
activities, the firing ship has transited a distance equal to double
that of the mitigation zone size beyond the location of the last
sighting.
(6) Explosive Sonobuoys. (i) Number of Lookouts and Observation
Platform--One lookout positioned in an aircraft or on small boat.
(ii) Mitigation Zone and Requirements--600 yd around an explosive
sonobuoy.
(A) Prior to the start of the activity (e.g., during deployment of
a sonobuoy field, which typically lasts 20-30 min), the Navy shall
conduct passive acoustic monitoring for marine mammals, and observe for
floating vegetation and marine mammals; if resource is visually
observed, the Navy shall not commence sonobuoy or source/receiver pair
detonations.
(B) During the activity, the Navy shall observe for marine mammals;
if resource is observed, the Navy shall cease sonobuoy or source/
receiver pair detonations.
(C) To allow a sighted marine mammal to leave the mitigation zone,
the Navy shall not recommence the use of explosive sonobuoys until one
of the recommencement conditions has been met: The animal is observed
exiting the mitigation zone; the animal is thought to have exited the
mitigation zone based on a determination of its course, speed, and
movement relative to the sonobuoy; or the mitigation zone has been
clear from any additional sightings for 10 min when the activity
involves aircraft that have fuel constraints, or 30 min when the
activity involves aircraft that are not typically fuel constrained.
(7) Explosive Torpedoes. (i) Number of Lookouts and Observation
Platform--One lookout positioned in an aircraft.
(ii) Mitigation Zone and Requirements--2,100 yd around the intended
impact location.
(A) Prior to the start of the activity (e.g., during deployment of
the target), the Navy shall conduct passive acoustic monitoring for
marine mammals, and observe for floating vegetation, jellyfish
aggregations, and marine mammals; if resource is visually observed, the
Navy shall not commence firing.
(B) During the activity, the Navy shall observe for marine mammals
and jellyfish aggregations; if resource is observed, the Navy shall
cease firing.
(C) To allow a sighted marine mammal to leave the mitigation zone,
the Navy shall not recommence firing until one of the recommencement
conditions has been met: The animal is observed exiting the mitigation
zone; the animal is thought to have exited the mitigation zone based on
a determination of its course, speed, and movement relative to the
intended impact location; or the mitigation zone has been clear from
any additional sightings for 10 min when the activity involves aircraft
that have fuel constraints, or 30 min when the activity involves
aircraft that are not typically fuel constrained. After completion of
the activity, the Navy shall observe for marine mammals; if any injured
or dead resources are observed, the Navy shall follow established
incident reporting procedures.
(8) Explosive Medium-Caliber and Large-Caliber Projectiles. Gunnery
activities using explosive medium-caliber and large-caliber
projectiles. Mitigation applies to activities using a surface target.
(i) Number of Lookouts and Observation Platform--One Lookout on the
vessel or aircraft conducting the activity. For activities using
explosive large-caliber projectiles, depending on the activity, the
Lookout could be the same as the one described in Weapons Firing Noise
in paragraph (a)(5)(i) of this section.
(ii) Mitigation Zone and Requirements--(A) 200 yd around the
intended impact location for air-to-surface activities using explosive
medium-caliber projectiles,
(B) 600 yd around the intended impact location for surface-to-
surface activities using explosive medium-caliber projectiles, or
(C) 1,000 yd around the intended impact location for surface-to-
surface activities using explosive large-caliber projectiles:
(D) Prior to the start of the activity (e.g., when maneuvering on
station), the Navy shall observe for floating vegetation and marine
mammals; if resource is observed, the Navy shall not commence firing.
(E) During the activity, observe for marine mammals; if resource is
observed, the Navy shall cease firing.
(F) To allow a sighted marine mammal to leave the mitigation zone,
the Navy shall not recommence firing until one of the recommencement
conditions has been met: The animal is observed exiting the mitigation
zone; the animal is thought to have exited the mitigation zone based on
a determination of its course, speed, and movement relative to the
intended impact location; the mitigation zone has been clear from any
additional sightings for 10 min. for aircraft-based firing or 30 min
for vessel-based firing; or for activities using mobile targets, the
intended impact location has transited a distance equal to double that
of the mitigation zone size beyond the location of the last sighting.
(9) Explosive Missiles and Rockets. Aircraft-deployed explosive
missiles and rockets. Mitigation applies to activities using a surface
target.
(i) Number of Lookouts and Observation Platform--One lookout
positioned in an aircraft.
(ii) Mitigation Zone and Requirements--(A) 900 yd around the
intended impact location for missiles or rockets with 0.6-20 lb net
explosive weight, or
(B) 2,000 yd around the intended impact location for missiles with
21-500 lb net explosive weight:
(C) Prior to the start of the activity (e.g., during a fly-over of
the mitigation zone), the Navy shall observe for floating vegetation
and marine mammals; if resource is observed, the Navy shall not
commence firing.
(D) During the activity, the Navy shall observe for marine mammals;
if resource is observed, the Navy shall cease firing.
(E) To allow a sighted marine mammal to leave the mitigation zone,
the Navy shall not recommence firing until one of the recommencement
conditions has been met: The animal is observed exiting the mitigation
zone; the animal is thought to have exited the mitigation zone based on
a determination of its course, speed, and movement relative to the
intended impact location; or the mitigation zone has been clear from
any additional sightings for 10 min when the activity involves aircraft
that have fuel constraints, or 30 min when the activity involves
aircraft that are not typically fuel constrained.
(10) Explosive Bombs. (i) Number of Lookouts and Observation
Platform--One lookout positioned in an aircraft conducting the
activity.

[[Page 11091]]

(ii) Mitigation Zone and Requirements--2,500 yd around the intended
target.
(A) Prior to the start of the activity (e.g., when arriving on
station), the Navy shall observe for floating vegetation and marine
mammals; if resource is observed, the Navy shall not commence bomb
deployment.
(B) During target approach, the Navy shall observe for marine
mammals; if resource is observed, the Navy shall cease bomb deployment.
(C) To allow a sighted marine mammal to leave the mitigation zone,
the Navy shall not recommence bomb deployment until one of the
recommencement conditions has been met: The animal is observed exiting
the mitigation zone; the animal is thought to have exited the
mitigation zone based on a determination of its course, speed, and
movement relative to the intended target; the mitigation zone has been
clear from any additional sightings for 10 min; or for activities using
mobile targets, the intended target has transited a distance equal to
double that of the mitigation zone size beyond the location of the last
sighting.
(11) Sinking Exercises. (i) Number of Lookouts and Observation
Platform--Two lookouts (one positioned in an aircraft and one on a
vessel).
(ii) Mitigation Zone and Requirements--2.5 nmi around the target
ship hulk.
(A) 90 min prior to the first firing, the Navy shall conduct aerial
observations for floating vegetation, jellyfish aggregations, and
marine mammals; if resource is observed, the Navy shall not commence
firing.
(B) During the activity, the Navy shall conduct passive acoustic
monitoring and visually observe for marine mammals from the vessel; if
resource is visually observed, the Navy shall cease firing. Immediately
after any planned or unplanned breaks in weapons firing of longer than
2 hrs, the Navy shall observe for marine mammals from the aircraft and
vessel; if resource is observed, the Navy shall not commence firing.
(C) To allow a sighted marine mammal to leave the mitigation zone,
the Navy shall not recommence firing until one of the recommencement
conditions has been met: The animal is observed exiting the mitigation
zone; the animal is thought to have exited the mitigation zone based on
a determination of its course, speed, and movement relative to the
target ship hulk; or the mitigation zone has been clear from any
additional sightings for 30 min. For 2 hrs after sinking the vessel (or
until sunset, whichever comes first), observe for marine mammals; if
any injured or dead resources are observed, the Navy shall follow
established incident reporting procedures.
(12) Explosive Mine Countermeasure and Neutralization Activities.
(i) Number of Lookouts and Observation Platform--(A) One lookout
positioned on a vessel or in an aircraft when using up to 0.1-5 lb net
explosive weight charges.
(B) Two lookouts (one in an aircraft and one on a small boat) when
using up to 6-650 lb net explosive weight charges.
(ii) Mitigation Zone and Requirements--(A) 600 yd around the
detonation site for activities using 0.1-5 lb net explosive weight, or
(B) 2,100 yd around the detonation site for activities using 6-650
lb net explosive weight (including high explosive target mines):
(C) Prior to the start of the activity (e.g., when maneuvering on
station; typically, 10 min when the activity involves aircraft that
have fuel constraints, or 30 min when the activity involves aircraft
that are not typically fuel constrained), the Navy shall observe for
floating vegetation and marine mammals; if resource is observed, the
Navy shall not commence detonations.
(D) During the activity, the Navy shall observe for marine mammals;
if resource is observed, the Navy shall cease detonations.
(E) To allow a sighted marine mammal to leave the mitigation zone,
the Navy shall not recommence detonations until one of the
recommencement conditions has been met: The animal is observed exiting
the mitigation zone; the animal is thought to have exited the
mitigation zone based on a determination of its course, speed, and
movement relative to detonation site; or the mitigation zone has been
clear from any additional sightings for 10 min when the activity
involves aircraft that have fuel constraints, or 30 min when the
activity involves aircraft that are not typically fuel constrained.
After completion of the activity, the Navy shall observe for marine
mammals and sea turtles (typically 10 min when the activity involves
aircraft that have fuel constraints, or 30 min. when the activity
involves aircraft that are not typically fuel constrained); if any
injured or dead resources are observed, the Navy shall follow
established incident reporting procedures.
(13) Explosive Mine Neutralization Activities Involving Navy
Divers. (i) Number of Lookouts and Observation Platform--(A) Two
lookouts (two small boats with one Lookout each, or one Lookout on a
small boat and one in a rotary-wing aircraft) when implementing the
smaller mitigation zone.
(B) Four lookouts (two small boats with two Lookouts each), and a
pilot or member of an aircrew shall serve as an additional Lookout if
aircraft are used during the activity, when implementing the larger
mitigation zone.
(ii) Mitigation Zone and Requirements--(A) The Navy shall not set
time-delay firing devices (0.1-20 lb net explosive weight) to exceed 10
min.
(B) 500 yd around the detonation site during activities under
positive control using 0.1-20 lb net explosive weight, or
(C) 1,000 yd around the detonation site during all activities using
time-delay fuses (0.1-20 lb net explosive weight) and during activities
under positive control using 21-60 lb net explosive weight charges:
(D) Prior to the start of the activity (e.g., when maneuvering on
station for activities under positive control; 30 min for activities
using time-delay firing devices), the Navy shall observe for floating
vegetation and marine mammals; if resource is observed, the Navy shall
not commence detonations or fuse initiation.
(E) During the activity, the Navy shall observe for marine mammals;
if resource is observed, the Navy shall cease detonations or fuse
initiation. All divers placing the charges on mines shall support the
Lookouts while performing their regular duties and shall report all
marine mammal sightings to their supporting small boat or Range Safety
Officer. To the maximum extent practicable depending on mission
requirements, safety, and environmental conditions, boats shall
position themselves near the mid-point of the mitigation zone radius
(but outside of the detonation plume and human safety zone), shall
position themselves on opposite sides of the detonation location (when
two boats are used), and shall travel in a circular pattern around the
detonation location with one Lookout observing inward toward the
detonation site and the other observing outward toward the perimeter of
the mitigation zone. If used, aircraft shall travel in a circular
pattern around the detonation location to the maximum extent
practicable.
(F) To allow a sighted marine mammal to leave the mitigation zone,
the Navy shall not recommence detonations or fuse initiation until one
of the recommencement conditions has been met: The animal is observed
exiting the mitigation zone; the animal is thought to have exited the
mitigation zone based on a determination of its

[[Page 11092]]

course, speed, and movement relative to the detonation site; or the
mitigation zone has been clear from any additional sightings for 10 min
during activities under positive control with aircraft that have fuel
constraints, or 30 min. during activities under positive control with
aircraft that are not typically fuel constrained and during activities
using time-delay firing devices. After completion of an activity using
time-delay firing devices, the Navy shall observe for marine mammals
for 30 min; if any injured or dead resources are observed, the Navy
follow established incident reporting procedures.
(14) Maritime Security Operations--Anti-Swimmer Grenades. (i)
Number of Lookouts and Observation Platform--One lookout positioned on
the small boat conducting the activity.
(ii) Mitigation Zone and Requirements--200 yd around the intended
detonation location.
(A) Prior to the start of the activity (e.g., when maneuvering on
station), the Navy shall observe for floating vegetation and marine
mammals; if resource is observed, the Navy shall not commence
detonations.
(B) During the activity, the Navy shall observe for marine mammals;
if resource is observed, the Navy shall cease detonations.
(C) To allow a sighted marine mammal to leave the mitigation zone,
the Navy shall not recommence detonations until one of the
recommencement conditions has been met: The animal is observed exiting
the mitigation zone; the animal is thought to have exited the
mitigation zone based on a determination of its course, speed, and
movement relative to the intended detonation location; the mitigation
zone has been clear from any additional sightings for 30 min; or the
intended detonation location has transited a distance equal to double
that of the mitigation zone size beyond the location of the last
sighting.
(15) Line Charge Testing. (i) Number of Lookouts and Observation
Platform--One lookout positioned on a vessel.
(ii) Mitigation Zone and Requirements--900 yd around the intended
detonation location.
(A) Prior to the start of the activity (e.g., when maneuvering on
station), the Navy shall observe for floating vegetation and marine
mammals; if resource is observed, the Navy shall not commence
detonations.
(B) During the activity, the Navy shall observe for marine mammals;
if resource is observed, the Navy shall cease detonations.
(C) To allow a sighted marine mammal to leave the mitigation zone,
the Navy shall not recommence detonations until one of the
recommencement conditions has been met: The animal is observed exiting
the mitigation zone; the animal is thought to have exited the
mitigation zone based on a determination of its course, speed, and
movement relative to the intended detonation location; or the
mitigation zone has been clear from any additional sightings for 30
min.
(16) Ship Shock Trials. (i) Number of Lookouts and Observation
Platform--(A) A minimum of ten lookouts or trained marine species
observers (or a combination thereof) positioned either in an aircraft
or on multiple vessels (i.e., a Marine Animal Response Team boat and
the test ship).
(B) If aircraft are used, Lookouts or trained marine species
observers shall be in an aircraft and on multiple vessels.
(C) If aircraft are not used, a sufficient number of additional
Lookouts or trained marine species observers shall be used to provide
vessel-based visual observation comparable to that achieved by aerial
surveys.
(ii) Mitigation Zone and Requirements--3.5 nmi around the ship
hull.
(A) The Navy shall not conduct ship shock trials in the
Jacksonville Operating Area during North Atlantic right whale calving
season from November 15 through April 15.
(B) The Navy develops detailed ship shock trial monitoring and
mitigation plans approximately one-year prior to an event and shall
continue to provide these to NMFS for review and approval.
(C) Pre-activity planning shall include selection of one primary
and two secondary areas where marine mammal populations are expected to
be the lowest during the event, with the primary and secondary
locations located more than 2 nmi from the western boundary of the Gulf
Stream for events in the Virginia Capes Range Complex or Jacksonville
Range Complex.
(D) If it is determined during pre-activity surveys that the
primary area is environmentally unsuitable (e.g., observations of
marine mammals or presence of concentrations of floating vegetation),
the shock trial could be moved to a secondary site in accordance with
the detailed mitigation and monitoring plan provided to NMFS.
(E) Prior to the detonation (at the primary shock trial location)
in intervals of 5 hrs, 3 hrs, 40 min, and immediately before the
detonation, the Navy shall observe for floating vegetation and marine
mammals; if resource is observed, the Navy shall not trigger the
detonation.
(F) During the activity, the Navy shall observe for marine mammals,
large schools of fish, jellyfish aggregations, and flocks of seabirds;
if resource is observed, the Navy shall cease triggering the
detonation.
(G) To allow a sighted marine mammal to leave the mitigation zone,
the Navy shall not recommence the triggering of a detonation until one
of the recommencement conditions has been met: The animal is observed
exiting the mitigation zone; the animal is thought to have exited the
mitigation zone based on a determination of its course, speed, and
movement relative to the ship hull; or the mitigation zone has been
clear from any additional sightings for 30 min. After completion of
each detonation, the Navy shall observe for marine mammals; if any
injured or dead resources are observed, the Navy shall follow
established incident reporting procedures and halt any remaining
detonations until the Navy can consult with NMFS and review or adapt
the mitigation, if necessary. After completion of the ship shock trial,
the Navy shall conduct additional observations during the following two
days (at a minimum) and up to seven days (at a maximum); if any injured
or dead resources are observed, the Navy shall follow established
incident reporting procedures.
(17) Vessel Movement. The mitigation shall not be applied if: The
vessel's safety is threatened; the vessel is restricted in its ability
to maneuver (e.g., during launching and recovery of aircraft or landing
craft, during towing activities, when mooring, etc.); or the vessel is
operated autonomously.
(i) Number of Lookouts and Observation Platform--One lookout on the
vessel that is underway.
(ii) Mitigation Zone and Requirements--(A) 500 yd around whales--
When underway, the Navy shall observe for marine mammals; if a whale is
observed, the Navy shall maneuver to maintain distance.
(B) 200 yd around all other marine mammals (except bow-riding
dolphins and pinnipeds hauled out on man-made navigational structures,
port structures, and vessels)--When underway, the Navy shall observe
for marine mammals; if a marine mammal other than a whale, bow-riding
dolphin, or hauled-out pinniped is observed, the Navy shall maneuver to
maintain distance.
(18) Towed In-water Devices. Mitigation applies to devices that are
towed from a manned surface platform or manned aircraft. The mitigation
shall not be applied if the safety of the towing platform is
threatened.

[[Page 11093]]

(i) Number of Lookouts and Observation Platform--One lookout
positioned on a manned towing platform.
(ii) Mitigation Zone and Requirements--250 yd around marine
mammals. When towing an in-water device, the Navy shall observe for
marine mammals; if resource is observed, the Navy shall maneuver to
maintain distance.
(19) Small-, Medium-, and Large-Caliber Non-Explosive Practice
Munitions. Mitigation applies to activities using a surface target.
(i) Number of Lookouts and Observation Platform--One Lookout
positioned on the platform conducting the activity. Depending on the
activity, the Lookout could be the same as the one described for
Weapons Firing Noise in paragraph (a)(5)(i) of this section.
(ii) Mitigation Zone and Requirements--200 yd around the intended
impact location.
(A) Prior to the start of the activity (e.g., when maneuvering on
station), the Navy shall observe for floating vegetation and marine
mammals; if resource is observed, the Navy shall not commence firing.
(B) During the activity, the Navy shall observe for marine mammals;
if resource is observed, the Navy shall cease firing.
(C) To allow a sighted marine mammal to leave the mitigation zone,
the Navy shall not recommence firing until one of the recommencement
conditions has been met: The animal is observed exiting the mitigation
zone; the animal is thought to have exited the mitigation zone based on
a determination of its course, speed, and movement relative to the
intended impact location; the mitigation zone has been clear from any
additional sightings for 10 min for aircraft-based firing or 30 min for
vessel-based firing; or for activities using a mobile target, the
intended impact location has transited a distance equal to double that
of the mitigation zone size beyond the location of the last sighting.
(20) Non-Explosive Missiles and Rockets. Aircraft-deployed non-
explosive missiles and rockets. Mitigation applies to activities using
a surface target.
(i) Number of Lookouts and Observation Platform--One Lookout
positioned in an aircraft.
(ii) Mitigation Zone and Requirements--900 yd around the intended
impact location.
(A) Prior to the start of the activity (e.g., during a fly-over of
the mitigation zone), the Navy shall observe for floating vegetation
and marine mammals; if resource is observed, the Navy shall not
commence firing.
(B) During the activity, the Navy shall observe for marine mammals;
if resource is observed, the Navy shall cease firing.
(C) To allow a sighted marine mammal to leave the mitigation zone,
the Navy shall not recommence firing until one of the recommencement
conditions has been met: The animal is observed exiting the mitigation
zone; the animal is thought to have exited the mitigation zone based on
a determination of its course, speed, and movement relative to the
intended impact location; or the mitigation zone has been clear from
any additional sightings for 10 min when the activity involves aircraft
that have fuel constraints, or 30 min when the activity involves
aircraft that are not typically fuel constrained.
(21) Non-Explosive Bombs and Mine Shapes. Non-explosive bombs and
non-explosive mine shapes during mine laying activities.
(i) Number of Lookouts and Observation Platform--One Lookout
positioned in an aircraft.
(ii) Mitigation Zone and Requirements--1,000 yd around the intended
target.
(A) Prior to the start of the activity (e.g., when arriving on
station), the Navy shall observe for floating vegetation and marine
mammals; if resource is observed, the Navy shall not commence bomb
deployment or mine laying. During approach of the target or intended
minefield location, the Navy shall observe for marine mammals; if
resource is observed, the Navy shall cease bomb deployment or mine
laying. To allow a sighted marine mammal to leave the mitigation zone,
the Navy shall not recommence bomb deployment or mine laying until one
of the recommencement conditions has been met: The animal is observed
exiting the mitigation zone; the animal is thought to have exited the
mitigation zone based on a determination of its course, speed, and
movement relative to the intended target or minefield location; the
mitigation zone has been clear from any additional sightings for 10
min; or for activities using mobile targets, the intended target has
transited a distance equal to double that of the mitigation zone size
beyond the location of the last sighting.
(B) [Reserved]
(b) Mitigation Areas. In addition to procedural mitigation, the
Navy shall implement mitigation measures within mitigation areas to
avoid potential impacts on marine mammals.
(1) Mitigation Areas off the Northeastern United States for sonar,
explosives, and physical disturbance and strikes.
(i) Mitigation Area Requirements--(A) Northeast North Atlantic
Right Whale Mitigation Areas (year-round):
(1) The Navy shall minimize the use of low-frequency active sonar,
mid-frequency active sonar, and high-frequency active sonar to the
maximum extent practicable.
(2) The Navy shall not use Improved Extended Echo Ranging sonobuoys
(within 3 nmi of the mitigation area), explosive and non-explosive
bombs, in-water detonations, and explosive torpedoes.
(3) For activities using non-explosive torpedoes, the Navy shall
conduct activities during daylight hours in Beaufort sea state 3 or
less. The Navy shall use three Lookouts (one positioned on a vessel and
two in an aircraft during dedicated aerial surveys) to observe the
vicinity of the activity. An additional Lookout shall be positioned on
the submarine, when surfaced. Immediately prior to the start of the
activity, Lookouts shall observe for floating vegetation and marine
mammals; if the resource is observed, the activity shall not commence.
During the activity, Lookouts shall observe for marine mammals; if
observed, the activity shall cease. To allow a sighted marine mammal to
leave the area, the Navy shall not recommence the activity until one of
the recommencement conditions has been met: The animal is observed
exiting the vicinity of the activity; the animal is thought to have
exited the vicinity of the activity based on a determination of its
course, speed, and movement relative to the activity location; or the
area has been clear from any additional sightings for 30 min. During
transits and normal firing, ships shall maintain a speed of no more
than 10 knots. During submarine target firing, ships shall maintain
speeds of no more than 18 knots. During vessel target firing, ship
speeds may exceed 18 knots for brief periods of time (e.g., 10-15 min).
(4) For all activities, before vessel transits, the Navy shall
conduct a web query or email inquiry to the National Oceanographic and
Atmospheric Administration Northeast Fisheries Science Center's North
Atlantic Right Whale Sighting Advisory System to obtain the latest
North Atlantic right whale sighting information. Vessels shall use the
obtained sightings information to reduce potential interactions with
North Atlantic right whales during transits. Vessels shall implement
speed reductions after they observe a North Atlantic right whale, if
they are within 5 nmi of a sighting

[[Page 11094]]

reported to the North Atlantic Right Whale Sighting Advisory System
within the past week, and when operating at night or during periods of
reduced visibility.
(B) Gulf of Maine Planning Awareness Mitigation Area (year-round):
(1) The Navy shall not plan major training exercises (Composite
Training Unit Exercises or Fleet Exercises/Sustainment Exercises), and
shall not conduct more than 200 hrs of hull-mounted mid-frequency
active sonar per year.
(2) If the Navy needs to conduct major training exercises or more
than 200 hrs of hull-mounted mid-frequency active sonar per year for
national security, it shall provide NMFS with advance notification and
include the information in any associated training or testing
activities or monitoring reports.
(C) Northeast Planning Awareness Mitigation Areas (year-round):
(1) The Navy shall avoid planning major training exercises
(Composite Training Unit Exercises or Fleet Exercises/Sustainment
Exercises) to the maximum extent practicable.
(2) The Navy shall not conduct more than four major training
exercises per year (all or a portion of the exercise).
(3) If the Navy needs to conduct additional major training
exercises for national security, it shall provide NMFS with advance
notification and include the information in any associated training
activity or monitoring reports.
(ii) [Reserved]
(2) Mitigation Areas off the Mid-Atlantic and Southeastern United
States for sonar, explosives, and physical disturbance and strikes.
(i) Mitigation Area Requirements--(A) Southeast North Atlantic
Right Whale Mitigation Area (November 15 through April 15):
(1) The Navy shall not conduct: Low-frequency active sonar (except
as noted below), mid-frequency active sonar (except as noted below),
high-frequency active sonar, missile and rocket activities (explosive
and non-explosive), small-, medium-, and large-caliber gunnery
activities, Improved Extended Echo Ranging sonobuoy activities,
explosive and non-explosive bombing activities, in-water detonations,
and explosive torpedo activities.
(2) To the maximum extent practicable, the Navy shall minimize the
use of: Helicopter dipping sonar, low-frequency active sonar and hull-
mounted mid-frequency active sonar used for navigation training, and
low-frequency active sonar and hull-mounted mid-frequency active sonar
used for object detection exercises.
(3) Before transiting or conducting training or testing activities,
the Navy shall initiate communication with the Fleet Area Control and
Surveillance Facility, Jacksonville to obtain Early Warning System
North Atlantic right whale sightings data. The Fleet Area Control and
Surveillance Facility, Jacksonville shall advise vessels of all
reported whale sightings in the vicinity to help vessels and aircraft
reduce potential interactions with North Atlantic right whales.
Commander Submarine Force, Atlantic shall coordinate any submarine
operations that may require approval from the Fleet Area Control and
Surveillance Facility, Jacksonville. Vessels shall use the obtained
sightings information to reduce potential interactions with North
Atlantic right whales during transits. Vessels shall implement speed
reductions after they observe a North Atlantic right whale, if they are
within 5 nmi of a sighting reported within the past 12 hrs, or when
operating at night or during periods of poor visibility. To the maximum
extent practicable, vessels shall minimize north-south transits.
(B) Mid-Atlantic Planning Awareness Mitigation Areas (year-round):
(1) The Navy shall avoid planning major training exercises
(Composite Training Unit Exercises or Fleet Exercises/Sustainment
Exercises) to the maximum extent practicable.
(2) The Navy shall not conduct more than four major training
exercises per year (all or a portion of the exercise).
(3) If the Navy needs to conduct additional major training
exercises for national security, it shall provide NMFS with advance
notification and include the information in any associated training
activity or monitoring reports.
(3) Mitigation Areas in the Gulf of Mexico for sonar. (i)
Mitigation Area Requirements--(A) Gulf of Mexico Planning Awareness
Mitigation Areas (year-round):
(1) The Navy shall avoid planning major training exercises (i.e.,
Composite Training Unit Exercises or Fleet Exercises/Sustainment
Exercises) involving the use of active sonar to the maximum extent
practicable.
(2) The Navy shall not conduct any major training exercises in the
Gulf of Mexico Planning Awareness Mitigation Areas under the Proposed
Activity.
(3) If the Navy needs to conduct additional major training
exercises in these areas for national security, it shall provide NMFS
with advance notification and include the information in any associated
training activity or monitoring reports.
(B) [Reserved]

Sec. 218.85 Requirements for monitoring and reporting.

(a) The Navy must notify NMFS immediately (or as soon as
operational security considerations allow) if the specified activity
identified in Sec. 218.80 is thought to have resulted in the mortality
or injury of any marine mammals, or in any take of marine mammals not
identified in this subpart.
(b) The Navy must conduct all monitoring and required reporting
under the LOAs, including abiding by the AFTT Study Area monitoring
program. Details on program goals, objectives, project selection
process, and current projects available at
www.navymarinespeciesmonitoring.us.
(c) Notification of injured, live stranded, or dead marine mammals.
The Navy shall abide by the Notification and Reporting Plan, which sets
out notification, reporting, and other requirements when dead, injured,
or live stranded marine mammals are detected.
(d) Annual AFTT Study Area marine species monitoring report. The
Navy shall submit an annual report of the AFTT Study Area monitoring
describing the implementation and results from the previous calendar
year. Data collection methods shall be standardized across range
complexes and study areas to allow for comparison in different
geographic locations. 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 to
the Director, Office of Protected Resources, NMFS. Such a report would
describe progress of knowledge made with respect to monitoring plan
study questions across all Navy ranges associated with the Integrated
Comprehensive Monitoring Program. 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.
(e) Annual AFTT Study Area training and testing reports. Each year,
the Navy shall submit a preliminary report (Quick Look Report)
detailing the status of authorized sound sources within 21 days after
the anniversary of the date of issuance of each LOA to the Director,
Office of Protected Resources, NMFS. Each year, the Navy shall submit a
detailed report within 3 months after the anniversary of the date of
issuance of each LOA the Director, Office of Protected Resources, NMFS.
The annual reports shall contain information on

[[Page 11095]]

Major Training Exercises (MTEs), Sinking Exercise (SINKEX) events, and
a summary of all sound sources used, as described in paragraph (e)(3)
of this section. The analysis in the detailed report shall be based on
the accumulation of data from the current year's report and data
collected from previous the report. The detailed reports shall contain
information identified in paragraphs (e)(1) through (5) of this
section.
(1) MTEs--This section shall contain the following information for
MTEs conducted in the AFTT Study Area:
(i) Exercise Information (for each MTE):
(A) Exercise designator.
(B) Date that exercise began and ended.
(C) Location.
(D) Number and types of active sonar sources used in the exercise.
(E) Number and types of passive acoustic sources used in exercise.
(F) Number and types of vessels, aircraft, etc., participating in
exercise.
(G) Total hours of observation by lookouts.
(H) Total hours of all active sonar source operation.
(I) Total hours of each active sonar source bin.
(J) Wave height (high, low, and average during exercise).
(ii) Individual marine mammal sighting information for each
sighting in each exercise when mitigation occurred:
(A) Date/Time/Location of sighting.
(B) Species (if not possible, indication of whale/dolphin/
pinniped).
(C) Number of individuals.
(D) Initial Detection Sensor.
(E) Indication of specific type of platform observation made from
(including, for example, what type of surface vessel or testing
platform).
(F) Length of time observers maintained visual contact with marine
mammal.
(G) Sea state.
(H) Visibility.
(I) Sound source in use at the time of sighting.
(J) Indication of whether animal is <200 yd, 200 to 500 yd, 500 to
1,000 yd, 1,000 to 2,000 yd, or >2,000 yd from sonar source.
(K) Mitigation implementation. Whether operation of sonar sensor
was delayed, or sonar was powered or shut down, and how long the delay
was.
(L) If source in use is hull-mounted, true bearing of animal from
ship, true direction of ship's travel, and estimation of animal's
motion relative to ship (opening, closing, parallel).
(M) Observed behavior. Lookouts shall report, in plain language and
without trying to categorize in any way, the observed behavior of the
animals (such as animal closing to bow ride, paralleling course/speed,
floating on surface and not swimming, etc.) and if any calves present.
(iii) An evaluation (based on data gathered during all of the MTEs)
of the effectiveness of mitigation measures designed to minimize the
received level to which marine mammals may be exposed. This evaluation
shall identify the specific observations that support any conclusions
the Navy reaches about the effectiveness of the mitigation.
(2) SINKEXs. This section shall include the following information
for each SINKEX completed that year:
(i) Exercise information (gathered for each SINKEX):
(A) Location.
(B) Date and time exercise began and ended.
(C) Total hours of observation by lookouts before, during, and
after exercise.
(D) Total number and types of explosive source bins detonated.
(E) Number and types of passive acoustic sources used in exercise.
(F) Total hours of passive acoustic search time.
(G) Number and types of vessels, aircraft, etc., participating in
exercise.
(H) Wave height in feet (high, low, and average during exercise).
(J) Narrative description of sensors and platforms utilized for
marine mammal detection and timeline illustrating how marine mammal
detection was conducted.
(ii) Individual marine mammal observation (by Navy lookouts)
information (gathered for each marine mammal sighting) for each
sighting where mitigation was implemented:
(A) Date/Time/Location of sighting.
(B) Species (if not possible, indicate whale, dolphin, or
pinniped).
(C) Number of individuals.
(D) Initial detection sensor.
(E) Length of time observers maintained visual contact with marine
mammal.
(F) Sea state.
(G) Visibility.
(H) Whether sighting was before, during, or after detonations/
exercise, and how many minutes before or after.
(I) Distance of marine mammal from actual detonations--200 yd, 200
to 500 yd, 500 to 1,000 yd, 1,000 to 2,000 yd, or >2,000 yd (or target
spot if not yet detonated).
(J) Observed behavior. Lookouts shall report, in plain language and
without trying to categorize in any way, the observed behavior of the
animal(s) (such as animal closing to bow ride, paralleling course/
speed, floating on surface and not swimming etc.), including speed and
direction and if any calves present.
(K) Resulting mitigation implementation. Indicate whether explosive
detonations were delayed, ceased, modified, or not modified due to
marine mammal presence and for how long.
(L) If observation occurs while explosives are detonating in the
water, indicate munition type in use at time of marine mammal
detection.
(3) Summary of sources used. This section shall include the
following information summarized from the authorized sound sources used
in all training and testing events:
(i) Total annual hours or quantity (per the LOA) of each bin of
sonar or other acoustic sources (pile driving and air gun activities);
(ii) Total annual expended/detonated rounds (missiles, bombs,
sonobuoys, etc.) for each explosive bin.
(4) Geographic information presentation. The reports shall present
an annual (and seasonal, where practical) depiction of training and
testing events and bin usage (as well as pile driving activities)
geographically across the AFTT Study Area.
(5) Sonar exercise notification. The Navy shall submit to NMFS
(contact as specified in the LOA) an electronic report within fifteen
calendar days after the completion of any MTE indicating:
(i) Location of the exercise;
(ii) Beginning and end dates of the exercise; and
(iii) Type of exercise.
(f) Five-year close-out comprehensive training and testing report.
This report shall be included as part of the 2023 annual training and
testing report. This report shall provide the annual totals for each
sound source bin with a comparison to the annual allowance and the
five-year total for each sound source bin with a comparison to the
five-year allowance. Additionally, if there were any changes to the
sound source allowance, this report shall 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 EIS and final rule
determinations. The report shall be submitted three months after the
expiration of this subpart to the Director, Office of Protected
Resources, NMFS. NMFS shall submit comments on the draft close-out
report, if any, within three months of receipt. The report shall be
considered final after the Navy has addressed NMFS' comments, or 3
months after the submittal of the

[[Page 11096]]

draft if NMFS does not provide comments.

Sec. 218.86 Letters of Authorization.

(a) To incidentally take marine mammals pursuant to these
regulations in this subpart, the Navy must apply for and obtain Letters
of Authorization (LOAs) in accordance with Sec. 216.106 of this
subpart, conducting the activity identified in Sec. 218.80(c).
(b) LOAs, unless suspended or revoked, may be effective for a
period of time not to exceed the expiration date of these regulations
in this subpart.
(c) If an LOA(s) expires prior to the expiration date of these
regulations in this subpart, the Navy may apply for and obtain a
renewal of the LOA(s).
(d) In the event of projected changes to the activity or to
mitigation, monitoring, reporting (excluding changes made pursuant to
the adaptive management provision of Sec. 218.87(c)(1)) required by an
LOA, the Navy must apply for and obtain a modification of LOAs as
described in Sec. 218.87.
(e) Each LOA shall set forth:
(1) Permissible methods of incidental taking;
(2) Authorized geographic areas for incidental taking;
(3) Means of effecting the least practicable adverse impact (i.e.,
mitigation) on the species of marine mammals, their habitat, and the
availability of the species for subsistence uses; and
(4) Requirements for monitoring and reporting.
(f) Issuance of the LOA(s) shall be based on a determination that
the level of taking shall be consistent with the findings made for the
total taking allowable under these regulations in this subpart.
(g) Notice of issuance or denial of the LOA(s) shall be published
in the Federal Register within 30 days of a determination.

Sec. 218.87 Renewals and modifications of Letters of Authorization.

(a) An LOA issued under Sec. Sec. 216.106 and 218.86 of this
subchapter for the activity identified in Sec. 218.80(c) shall be
renewed or modified upon request by 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 in this subpart
(excluding changes made pursuant to the adaptive management provision
in paragraph (c)(1) of this section), and
(2) NMFS determines that the mitigation, monitoring, and reporting
measures required by the previous LOA(s) under these regulations in
this subpart were implemented.
(b) For LOA modification or renewal requests by the applicant that
include changes to the activity or the mitigation, monitoring, or
reporting measures (excluding changes made pursuant to the adaptive
management provision in paragraph (c)(1) of this section) 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 of the change, and
solicit public comment before issuing the LOA.
(c) An LOA issued under Sec. 216.106 of this subchapter and Sec.
218.86 for the activity identified in Sec. 218.80(c) may be modified
by NMFS under the following circumstances:
(1) Adaptive Management--After consulting with the Navy regarding
the practicability of the modifications, NMFS may modify (including
adding or removing measures) the existing mitigation, monitoring, or
reporting measures if doing so creates a reasonable likelihood of more
effectively accomplishing the goals of the mitigation and monitoring
set forth in this subpart.
(i) Possible sources of data that could contribute to the decision
to modify the mitigation, monitoring, or reporting measures in an LOA:
(A) Results from the 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 in
this subpart or subsequent LOAs.
(ii) If, through adaptive management, the modifications to the
mitigation, monitoring, or reporting measures are substantial, NMFS
shall 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 LOAs issued pursuant to Sec. 216.106 of
this chapter and Sec. 218.86, an LOA may be modified without prior
notice or opportunity for public comment. Notice would be published in
the Federal Register within thirty days of the action.

Sec. Sec. 218.88-218.89 [Reserved]

[FR Doc. 2018-04517 Filed 3-12-18; 8:45 am]
BILLING CODE 3510-22-P