[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.

[[Page 10977]]

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[[Page 10978]]


[GRAPHIC] [TIFF OMITTED] TP13MR18.016


[[Page 10979]]


[GRAPHIC] [TIFF OMITTED] TP13MR18.017


[[Page 10980]]


[GRAPHIC] [TIFF OMITTED] TP13MR18.018

BILLING CODE 3510-22-C
    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:
        ○&; 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
        ○&; 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.
        ○&; 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.
        ○&; 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

    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

[[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

    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

[[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