[Federal Register Volume 79, Number 53 (Wednesday, March 19, 2014)]
[Proposed Rules]
[Pages 15388-15442]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-05833]



[[Page 15387]]

Vol. 79

Wednesday,

No. 53

March 19, 2014

Part II





Department of Commerce





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National Oceanic and Atmospheric Administration





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50 CFR Part 218





Takes of Marine Mammals Incidental to Specified Activities; U.S. Navy 
Training and Testing Activities in the Mariana Islands Training and 
Testing Study Area; Proposed Rule

  Federal Register / Vol. 79 , No. 53 / Wednesday, March 19, 2014 / 
Proposed Rules  

[[Page 15388]]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 218

[Docket 140211133-4133-01]
RIN 0648-BD69


Takes of Marine Mammals Incidental to Specified Activities; U.S. 
Navy Training and Testing Activities in the Mariana Islands 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 Mariana Islands Training and 
Testing (MITT) study area from March 2015 through March 2020. Pursuant 
to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments 
on its proposal to issue regulations and subsequent Letter of 
Authorization (LOA) to the Navy to incidentally harass marine mammals.

DATES: Comments and information must be received no later than May 5, 
2014.

ADDRESSES: You may submit comments, identified by 0648-BD69, by either 
of the following methods:
     Electronic submissions: submit all electronic public 
comments via the Federal eRulemaking Portal http://www.regulations.gov
     Hand delivery or mailing of paper, disk, or CD-ROM 
comments should be addressed to Jolie Harrison, Incidental Take Program 
Supervisor, Permits and Conservation Division, Office of Protected 
Resources, National Marine Fisheries Service, 1315 East-West Highway, 
Silver Spring, MD 20910-3225.
    Instructions: All comments received are a part of the public record 
and will generally be posted to http://www.regulations.gov without 
change. All Personal Identifying Information (for example, name, 
address, etc.) voluntarily submitted by the commenter may be publicly 
accessible. Do not submit Confidential Business Information or 
otherwise sensitive or protected information.
    NMFS will accept anonymous comments (enter N/A in the required 
fields if you wish to remain anonymous). Attachments to electronic 
comments will be accepted in Microsoft Word, Excel, WordPerfect, or 
Adobe PDF file formats only.
    An electronic copy of the Navy's application may be obtained by 
writing to the address specified above, telephoning the contact listed 
below (see FOR FURTHER INFORMATION CONTACT), or visiting the internet 
at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. 
The Navy's Draft Environmental Impact Statement/Overseas Environmental 
Impact Statement (DEIS/OEIS) for MITT was made available to the public 
on September 13, 2013 (78 FR 56682) and may also be viewed at http://www.mitt-eis.com. Documents cited in this notice may also be viewed, by 
appointment, during regular business hours, at the aforementioned 
address.

FOR FURTHER INFORMATION CONTACT: Michelle Magliocca, Office of 
Protected Resources, NMFS, (301) 427-8401.

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 to allow, upon request, the 
incidental, but not intentional, taking of small numbers of marine 
mammals by U.S. citizens who engage in a specified activity (other than 
commercial fishing) within a specified geographical region if certain 
findings are made and either regulations are issued or, if the taking 
is limited to harassment, a notice of a proposed authorization is 
provided to the public for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring, and reporting of such takings 
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103 
as ``an impact resulting from the specified activity that cannot be 
reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.''
    The National Defense Authorization Act of 2004 (NDAA) (Pub. L. 108-
136) removed the ``small numbers'' and ``specified geographical 
region'' limitations indicated above and amended the definition of 
``harassment'' as 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 April 22, 2013, NMFS received an application from the Navy 
requesting an LOA for the take of 26 species of marine mammals 
incidental to Navy training and testing activities to be conducted in 
the MITT Study Area over 5 years. The Navy is requesting regulations 
that would establish a process for authorizing take, via one 5-year 
LOA, of marine mammals for training and testing activities, proposed to 
be conducted from 2015 through 2020. The Study Area includes the 
existing Mariana Islands Range Complex and surrounding seas, a transit 
corridor between the Mariana Islands and the Navy's Hawaii Range 
Complex, and Navy pierside locations where sonar maintenance or testing 
may occur (see Figure 2-1 of the Navy's application for a map of the 
MITT Study Area). The proposed activities are classified as military 
readiness activities. Marine mammals present in the Study Area may be 
exposed to sound from active sonar and underwater detonations. In 
addition, incidental takes of marine mammals may occur from ship 
strikes. The Navy is requesting authorization to take 26 marine mammal 
species by Level B (behavioral) harassment and 13 marine mammal species 
by Level A harassment (injury) or mortality.
    The Navy's application and the MITT DEIS/OEIS contain proposed 
acoustic thresholds that were used to evaluate the Navy's Atlantic 
Fleet Training and Testing and Hawaii-Southern California Training and 
Testing activities. The revised thresholds are based on evaluation of 
recent scientific studies; a detailed explanation of how they were 
derived is provided in the MITT DEIS/OEIS' Criteria and Thresholds for 
U.S. Navy Acoustic and Explosive Effects Analysis Technical Report. 
NMFS is currently updating and revising all of its acoustic thresholds. 
Until that process is complete, NMFS will continue its long-standing 
practice of considering specific modifications to the acoustic 
thresholds currently employed for incidental take authorizations only 
after providing the

[[Page 15389]]

public with an opportunity for review and comment.

Background of Request

    The Navy's mission is to maintain, train, and equip combat-ready 
naval forces capable of winning wars, deterring aggression, and 
maintaining freedom of the seas. Section 5062 of Title 10 of the United 
States Code directs the Chief of Naval Operations to train all military 
forces for combat. The Chief of Naval Operations meets that direction, 
in part, by conducting at-sea training exercises and ensuring naval 
forces have access to ranges, operating areas (OPAREAs) and airspace 
where they can develop and maintain skills for wartime missions and 
conduct research, development, testing, and evaluation (RDT&E) of naval 
systems.
    The Navy proposes to continue conducting training and testing 
activities within the MITT Study Area, which have been ongoing for 
decades. Most of these activities were last analyzed in the Mariana 
Island Range Complex (MIRC) EIS/OEIS (U.S. Department of the Navy, 
2010). This document, among others, and its associated MMPA regulations 
and authorizations, describe the baseline of training and testing 
activities currently conducted in the Study Area. The tempo and types 
of training and testing activities have fluctuated due to changing 
requirements; new technologies; the dynamic nature of international 
events; advances in warfighting doctrine and procedures; and changes in 
basing locations for ships, aircraft, and personnel. Such developments 
influence the frequency, duration, intensity, and location of required 
training and testing activities. To meet these requirements, the Navy 
is proposing an increase in the number of events/activities and 
ordnance for training and testing purposes. The Navy's LOA request 
covers training and testing activities that would occur for a 5-year 
period following the expiration of the current MMPA authorizations. The 
Navy has also prepared a DEIS/OEIS analyzing the effects on the human 
environment of implementing their preferred alternative (among others).

Description of the Specified Activity

    The Navy is requesting authorization to take marine mammals 
incidental to conducting training and testing activities. The Navy has 
determined that sonar use, underwater detonations, and ship strike are 
the stressors most likely to result in impacts on marine mammals that 
could rise to the level of harassment. Detailed descriptions of these 
activities are provided in the MITT DEIS/OEIS and LOA application 
(http://www.nmfs.noaa.gov/pr/permits/incidental.htm) and are summarized 
here.

Overview of Training Activities

    The Navy, U.S. Air Force, U.S. Marine Corps, and U.S. Coast Guard 
routinely train in the MITT Study Area in preparation for national 
defense missions. Training activities are categorized into eight 
functional warfare areas (anti-air warfare; amphibious warfare; strike 
warfare; anti-surface warfare; anti-submarine warfare; electronic 
warfare; mine warfare; and naval special warfare). The Navy determined 
that the following stressors used in these warfare areas are most 
likely to result in impacts on marine mammals:

 Anti-surface warfare (underwater detonations)
 Anti-submarine warfare (active sonar, underwater detonations)
 Mine warfare (active sonar, underwater detonations)
 Naval special warfare (underwater detonations)

    Additionally, some activities described as Major Training 
Activities in the DEIS/OEIS and other activities are included in the 
analysis. The Navy's activities in amphibious warfare, anti-air 
warfare, strike warfare, and electronic warfare do not involve 
stressors that could result in harassment of marine mammals. Therefore, 
these activities are not discussed further. The analysis and rationale 
for excluding these warfare areas is contained in the DEIS/OEIS.
    Anti-surface Warfare--The mission of anti-surface warfare is to 
defend against enemy ships or boats. When conducting anti-surface 
warfare, aircraft use cannons, missiles, or other precision-guided 
munitions; ships use torpedoes, naval guns, and surface-to-surface 
missiles; and submarines use torpedoes or submarine-launched, anti-ship 
cruise missiles. Anti-surface warfare training includes surface-to-
surface gunnery and missile exercises, air-to-surface gunnery and 
missile exercises, and submarine missile or exercise torpedo launch 
events.
    Anti-submarine Warfare--The mission of anti-submarine warfare is to 
locate, neutralize, and defeat hostile submarine threats to surface 
forces. Anti-submarine warfare is based on the principle of a layered 
defense of surveillance and attack aircraft, ships, and submarines all 
searching for hostile submarines. These forces operate together or 
independently to gain early warning and detection, and to localize, 
track, target, and attack hostile submarine threats. Anti-submarine 
warfare training addresses basic skills such as detection and 
classification of submarines, distinguishing between sounds made by 
enemy submarines and those of friendly submarines, ships, and marine 
life. More advanced, integrated anti-submarine warfare training 
exercises are conducted in coordinated, at-sea training events 
involving submarines, ships, and aircraft. This training integrates the 
full spectrum of anti-submarine warfare from detecting and tracking a 
submarine to attacking a target using either exercise torpedoes or 
simulated weapons.
    Mine Warfare--The mission of mine warfare is to detect, and avoid 
or neutralize mines to protect Navy ships and submarines and to 
maintain free access to ports and shipping lanes. Mine warfare also 
includes offensive mine laying to gain control or deny the enemy access 
to sea space. Naval mines can be laid by ships, submarines, or 
aircraft. Mine warfare training includes exercises in which ships, 
aircraft, submarines, underwater vehicles, or marine mammal detection 
systems search for mines. Certain personnel train to destroy or disable 
mines by attaching and detonating underwater explosives to simulated 
mines. Other neutralization techniques involve impacting the mine with 
a bullet-like projectile or intentionally triggering the mine to 
detonate.
    Naval Special Warfare--The mission of naval special warfare is to 
conduct unconventional warfare, direct action, combat terrorism, 
special reconnaissance, information warfare, security assistance, 
counter-drug operations, and recovery of personnel from hostile 
situations. Naval special warfare operations are highly specialized and 
require continual and intense training. Naval special warfare units are 
required to utilize a combination of specialized training, equipment, 
and tactics, including insertion and extraction operations using 
parachutes, submerged vehicles, rubber boats, and helicopters; boat-to-
shore and boat-to-boat gunnery; underwater demolition training; 
reconnaissance; and small arms training.
    Major Training Activities--Major training activities involve 
multiple ships, aircraft, and submarines in a multi-day exercise. 
Different branches of the U.S. military participate in joint planning 
and execution efforts as well as military training activities at sea, 
in the air, and ashore. More than 8,000 personnel may participate and 
could include the combined assets of a Carrier

[[Page 15390]]

Strike Group and Expeditionary Strike Group, Marine Expeditionary 
Units, Army Infantry Units, and Air Force aircraft. One example of this 
coordinated activity is the Joint Multi Strike Group Exercise, a 10-day 
exercise in which up to three carrier strike groups conduct training 
exercises simultaneously.
    Other Activities--Surface ship and submarine sonar maintenance, 
described under Other Activities in the DEIS/OEIS, involve in-port and 
at-sea maintenance of sonar systems.

Overview of Testing Activities

    The Navy researches, develops, tests, and evaluates new platforms, 
systems, and technologies. Many tests are conducted in realistic 
conditions at sea, and can range in scale from testing new software to 
operating portable devices to conducting tests of live weapons to 
ensure they function as intended. Testing activities may occur 
independently of or in conjunction with training activities. Many 
testing activities are conducted similarly to Navy training activities 
and are also categorized under one of the primary mission areas. Other 
testing activities are unique and are described within their specific 
testing categories. The Navy determined that stressors used during the 
following testing activities are most likely to result in impacts on 
marine mammals:

 Naval Air Systems Command (NAVAIR) Testing
    [cir] Anti-surface warfare testing (underwater detonations)
    [cir] Anti-submarine warfare testing (active sonar, underwater 
detonations)
 Naval Sea Systems command (NAVSEA) Testing
    [cir] New ship construction (active sonar, underwater detonations)
    [cir] Life cycle activities (active sonar, underwater detonations)
    [cir] Anti-surface warfare/anti-submarine warfare testing (active 
sonar, underwater detonations)
    [cir] Ship protection systems and swimmer defense testing (active 
sonar)
 Office of Naval Research (ONR) and Naval Research Laboratory 
(NRL) Testing
    [cir] ONR/NRL research, development, test, and evaluation (active 
sonar)

    Other Navy testing activities do not involve stressors that could 
result in marine mammal harassment. Therefore, these activities are not 
discussed further.
    Naval Air Systems Command Testing (NAVAIR)--NAVAIR events include 
testing of new aircraft platforms, weapons, and systems before delivery 
to the fleet for training activities. In general, NAVAIR conducts its 
testing activities the same way the fleet conducts its training 
activities. However, NAVAIR testing activities may occur in different 
locations than equivalent fleet training activities and testing of a 
particular system may differ slightly from the way the fleet trains 
with the same system.
    Anti-surface Warfare Testing: Anti-surface warfare testing includes 
air-to-surface gunnery, missile, and rocket exercises. Testing is 
required to ensure the equipment is fully functional for defense from 
surface threats. Testing may be conducted on new guns or run rounds, 
missiles, rockets, and aircraft, and also in support of scientific 
research to assess new and emerging technologies. Testing events are 
often integrated into training activities and in most cases the systems 
are used in the same manner in which they are used for fleet training 
activities.
    Anti-submarine Warfare Testing: Anti-submarine warfare testing 
addresses basic skills such as detection and classification of 
submarines, distinguishing between sounds made by enemy submarines and 
those of friendly submarines, ships, and marine life. More advanced, 
integrated anti-submarine warfare testing is conducted in coordinated, 
at-sea training events involving submarines, ships, and aircraft. This 
testing integrates the full spectrum of anti-submarine warfare from 
detecting and tracking a submarine to attacking a target using various 
torpedoes and weapons.
    Naval Sea Systems Command Testing (NAVSEA)--NAVSEA testing 
activities are aligned with its mission of new ship construction, life 
cycle support, and other weapon systems development and testing.
    New Ship Construction Activities: Ship construction activities 
include testing of ship systems and developmental and operational test 
and evaluation programs for new technologies and systems. At-sea 
testing of systems aboard a ship may include sonar, acoustic 
countermeasures, radars, and radio equipment. At-sea test firing of 
shipboard weapon systems, including guns, torpedoes, and missiles, are 
also conducted.
    Life Cycle Activities: Testing activities are conducted throughout 
the life of a Navy ship to verify performance and mission capabilities. 
Sonar system testing occurs pierside during maintenance, repair, and 
overhaul availabilities, and at sea immediately following most major 
overhaul periods. Radar cross signature testing of surface ships is 
conducted on new vessels and periodically throughout a ship's life to 
measure how detectable the ship is by radar. Electromagnetic 
measurements of off-board electromagnetic signature are also conducted 
for submarines, ships, and surface craft periodically.
    Other Weapon Systems Development and Testing: Numerous test 
activities and technical evaluations, in support of NAVSEA's systems 
development mission, often occur with fleet activities within the Study 
Area. Tests within this category include anti-submarine and mine 
warfare tests using torpedoes, sonobuoys, and mine detection and 
neutralization systems. Swimmer detection systems are also tested 
pierside.
    Office of Naval Research and Naval Research Laboratory Testing (ONR 
and NRL)--As the Navy's science and technology provider, ONR and NRL 
provide technology solutions for Navy and Marine Corps needs. ONR's 
mission is to plan, foster, and encourage scientific research in 
recognition of its paramount importance as related to the maintenance 
of future naval power, and the preservation of national security. 
Further, ONR manages the Navy's basic, applied, and advanced research 
to foster transition from science and technology to higher levels of 
research, development, test, and evaluation. The Ocean Battlespace 
Sensing Department explores science and technology in the areas of 
oceanographic and meteorological observations, modeling, and prediction 
in the battlespace environment; submarine detection and classification 
(anti-submarine warfare); and mine warfare applications for detecting 
and neutralizing mines in both the ocean and littoral environment. ONR 
events include research, development, test, and evaluation activities; 
surface processes acoustic communications experiments; shallow water 
acoustic communications experiments; sediment acoustics experiments; 
shallow water acoustic propagation experiments; and long range acoustic 
propagation experiments.

Sonar, Ordnance, Targets, and Other Systems

    The Navy uses a variety of sensors, platforms, weapons, and other 
devices to meet its mission. Training and testing with these systems 
may introduce acoustic (sound) energy into the environment. This 
section describes and organizes sonar systems, ordnance, munitions, 
targets, and other systems to facilitate understanding of the 
activities in which these systems are used. Underwater sound is 
described as one of

[[Page 15391]]

two types for the purposes of the Navy's application: impulsive and 
non-impulsive. Underwater detonations of explosives and other 
percussive events are impulsive sounds. Sonar and other active acoustic 
systems are categorized as non-impulsive sound sources.
    Sonar and Other Non-impulsive Sources--Modern sonar technology 
includes a variety of sonar sensor and processing systems. The simplest 
active sonar emits sound waves, or ``pings,'' sent out in multiple 
directions and the sound waves then reflect off of the target object in 
multiple directions. The sonar source calculates the time it takes for 
the reflected sound waves to return; this calculation determines the 
distance to the target object. More sophisticated active sonar systems 
emit a ping and then rapidly scan or listen to the sound waves in a 
specific area. This provides both distance to the target and 
directional information. Even more advanced sonar systems use multiple 
receivers to listen to echoes from several directions simultaneously 
and provide efficient detection of both direction and distance. The 
Navy rarely uses active sonar continuously throughout activities. When 
sonar is in use, the pings occur at intervals, referred to as a duty 
cycle, and the signals themselves are very short in duration. For 
example, sonar that emits a 1-second ping every 10 seconds has a 10-
percent duty cycle. The Navy utilizes sonar systems and other acoustic 
sensors in support of a variety of mission requirements. Primary uses 
include the detection of and defense against submarines (anti-submarine 
warfare) and mines (mine warfare); safe navigation and effective 
communications; use of unmanned undersea vehicles; and oceanographic 
surveys.
    Ordnance and Munitions--Most ordnance and munitions used during 
training and testing events fall into three basic categories: 
projectiles (such as gun rounds), missiles (including rockets), and 
bombs. Ordnance can be further defined by their net explosive weight, 
which considers the type and quantity of the explosive substance 
without the packaging, casings, bullets, etc. Net explosive weight 
(NEW) is the trinitrotoluene (TNT) equivalent of energetic material, 
which is the standard measure of strength of bombs and other 
explosives. For example, a 12.7-centimeter (cm) shell fired from a Navy 
gun is analyzed at about 9.5 pounds (lb) (4.3 kilograms (kg)) of NEW. 
The Navy also uses non-explosive ordnance in place of high explosive 
ordnance in many training and testing events. Non-explosive ordnance 
munitions look and perform similarly to high explosive ordnance, but 
lack the main explosive charge.
    Defense Countermeasures--Naval forces depend on effective defensive 
countermeasures to protect themselves against missile and torpedo 
attack. Defensive countermeasures are devices designed to confuse, 
distract, and confound precision guided munitions. Defensive 
countermeasures analyzed in this LOA application include acoustic 
countermeasures, which are used by surface ships and submarines to 
defend against torpedo attack. Acoustic countermeasures are either 
released from ships and submarines, or towed at a distance behind the 
ship.
    Mine Warfare Systems--The Navy divides mine warfare systems into 
two categories: mine detection and mine neutralization. Mine detection 
systems are used to locate, classify, and map suspected mines. Once 
located, the mines can either be neutralized or avoided. The Navy 
analyzed the following mine detection systems for potential impacts to 
marine mammals:
     Towed or hull-mounted mine detection systems. These 
detection systems use acoustic, laser, and video sensors to locate and 
classify mines. Fixed and rotary wing aircraft platforms, ships, and 
unmanned vehicles are used for towed systems, which can rapidly assess 
large areas.
     Unmanned/remotely operated vehicles. These vehicles use 
acoustic, laser, and video sensors to locate and classify mines. 
Unmanned/remotely operated vehicles provide unique mine warfare 
capabilities in nearshore littoral areas, surf zones, ports, and 
channels.
    Mine Neutralization Systems--Mine neutralization systems disrupt, 
disable, or detonate mines to clear ports and shipping lanes, as well 
as littoral, surf, and beach areas in support of naval amphibious 
operations. The Navy analyzed the following mine neutralization systems 
for potential impacts to marine mammals:
     Towed influence mine sweep systems. These systems use 
towed equipment that mimic a particular ship's magnetic and acoustic 
signature triggering the mine and causing it to explode.
     Unmanned/remotely operated mine neutralization systems. 
Surface ships and helicopters operate these systems, which place 
explosive charges near or directly against mines to destroy the mine.
     Diver emplaced explosive charges. Operating from small 
craft, divers put explosive charges near or on mines to destroy the 
mine or disrupt its ability to function.

Classification of Non-Impulsive and Impulsive Sources Analyzed

    In order to better organize and facilitate the analysis of about 
300 sources of underwater non-impulsive sound or impulsive energy, the 
Navy developed a series of source classifications, or source bins. This 
method of analysis provides the following benefits:
     Allows for new sources to be covered under existing 
authorizations, as long as those sources fall within the parameters of 
a ``bin;''
     Simplifies the data collection and reporting requirements 
anticipated under the MMPA;
     Ensures a conservative approach to all impact analysis 
because all sources in a single bin are modeled as the loudest source 
(e.g., lowest frequency, highest source level, longest duty cycle, or 
largest net explosive weight within that bin);
     Allows analysis to be conducted more efficiently, without 
compromising the results;
     Provides a framework to support the reallocation of source 
usage (hours/explosives) between different source bins, as long as the 
total number and severity of marine mammal takes remain within the 
overall analyzed and authorized limits. This flexibility is required to 
support evolving Navy training and testing requirements, which are 
linked to real world events.
    A description of each source classification is provided in Tables 1 
and 2. Non-impulsive sources are grouped into bins based on the 
frequency, source level when warranted, and how the source would be 
used. Impulsive bins are based on the net explosive weight of the 
munitions or explosive devices. The following factors further describe 
how non-impulsive sources are divided:

 Frequency of the non-impulsive source:
    [cir] Low-frequency sources operate below 1 kilohertz (kHz)
    [cir] Mid-frequency sources operate at or above 1 kHz, up to and 
including 10 kHz
    [cir] High-frequency sources operate above 10 kHz, up to and 
including 100 kHz
    [cir] Very high-frequency sources operate above 100, but below 200 
kHz
 Source level of the non-impulsive source:
    [cir] Greater than 160 decibels (dB), but less than 180 dB
    [cir] Equal to 180 dB and up to 200 dB
    [cir] Greater than 200 dB

    How a sensor is used determines how the sensor's acoustic emissions 
are

[[Page 15392]]

analyzed. Factors to consider include pulse length (time source is on); 
beam pattern (whether sound is emitted as a narrow, focused beam, or, 
as with most explosives, in all directions); and duty cycle (how often 
a transmission occurs in a given time period during an event).
    There are also non-impulsive sources with characteristics that are 
not anticipated to result in takes of marine mammals. These sources 
have low source levels, narrow beam widths, downward directed 
transmission, short pulse lengths, frequencies beyond known hearing 
ranges of marine mammals, or some combination of these factors. These 
sources generally have frequencies greater than 200 kHz and/or source 
levels less than 160 dB and are qualitatively analyzed in the MITT 
DEIS/OEIS.

                         Table 1--Impulsive Training and Testing Source Classes Analyzed
----------------------------------------------------------------------------------------------------------------
       Source class              Representative munitions                  Net explosive weight (lbs)
----------------------------------------------------------------------------------------------------------------
E1........................  Medium-caliber projectiles.......  0.1-0.25 (45.4-113.4 g).
E2........................  Medium-caliber projectiles.......  0.26-0.5 (117.9-226.8 g).
E3........................  Large-caliber projectiles........  >0.5-2.5 (>226.8 g-1.1 kg).
E4........................  Improved Extended Echo Ranging     >2.5-5.0 (1.1-2.3 kg).
                             Sonobuoy.
E5........................  5 in. (12.7 cm) projectiles......  >5-10 (>2.3-4.5 kg).
E6........................  15 lb. (6.8 kg) shaped charge....  >10-20 (>4.5-9.1 kg).
E8........................  250 lb. (113.4 kg) bomb..........  >60-100 (>27.2-45.4 kg).
E9........................  500 lb. (226.8 kg) bomb..........  >100-250 (>45.4-113.4 kg).
E10.......................  1,000 lb. (453.6 kg) bomb........  >250-500 (>113.4-226.8 kg).
E11.......................  650 lb. (294.8 kg) mine..........  >500-650 (>226.8-294.8 kg).
E12.......................  2,000 lb. (907.2 kg) bomb........  >650-1,000 (>294.8-453.6 kg).
----------------------------------------------------------------------------------------------------------------


   Table 2--Non-Impulsive Training and Testing Source Classes Analyzed
------------------------------------------------------------------------
     Source class category         Source class         Description
------------------------------------------------------------------------
Low-Frequency (LF): Sources      LF4............  Low-frequency sources
 that produce low-frequency      LF5............   equal to 180 dB and
 (less than 1 kilohertz [kHz])   LF6............   up to 200 dB.
 signals.                                         Low-frequency sources
                                                   less than 180 dB.
                                                  Low-frequency sonar
                                                   currently in
                                                   development (e.g.,
                                                   anti-submarine
                                                   warfare sonar
                                                   associated with the
                                                   Littoral Combat
                                                   Ship).
Mid-Frequency (MF): Tactical     MF1............  Active hull-mounted
 and non-tactical sources that                     surface ship sonar
 produce mid-frequency (1 to 10                    (e.g., AN/SQS-53C and
 kHz) signals.                                     AN/SQS-60).
                                 MF2............  Active hull-mounted
                                                   surface ship sonar
                                                   (e.g., AN/SQS-56).
                                 MF3............  Active hull-mounted
                                                   submarine sonar
                                                   (e.g., AN/BQQ-10).
                                 MF4............  Active helicopter-
                                                   deployed dipping
                                                   sonar (e.g., AN/AQS-
                                                   22 and AN/AQS-13).
                                 MF5............  Active acoustic
                                                   sonobuoys (e.g.,
                                                   DICASS).
                                 MF6............  Active underwater
                                                   sound signal devices
                                                   (e.g., MK-84).
                                 MF8............  Active sources
                                                   (greater than 200 dB)
                                                   not otherwise binned.
                                 MF9............  Active sources (equal
                                                   to 180 dB and up to
                                                   200 dB).
                                 MF10...........  Active sources
                                                   (greater than 160 dB,
                                                   but less than 180 dB)
                                                   not otherwise binned.
                                 MF11...........  Hull-mounted surface
                                                   ship sonar with an
                                                   active duty cycle
                                                   greater than 80%.
                                 MF12...........  High duty cycle--
                                                   variable depth sonar.
High-Frequency (HF) and Very     HF1............  Active hull-mounted
 High-Frequency (VHF): Tactical  HF4............   submarine sonar
 and non-tactical sources that                     (e.g., AN/BQQ-10).
 produce high-frequency                           Active mine detection,
 (greater than 10 kHz but less                     classification, and
 than 200 kHz) signals.                            neutralization sonar
                                                   (e.g., AN/SQS-20).
                                 HF5............  Active sources
                                                   (greater than 200
                                                   dB).
                                 HF6............  Active sources (equal
                                                   to 180 dB and up to
                                                   200 dB).
Anti-Submarine Warfare (ASW):    ASW1...........  MF active Deep Water
 Tactical sources such as        ASW2...........   Active Distributed
 active sonobuoys and acoustic                     System (DWADS).
 countermeasures systems used                     MF active Multistatic
 during ASW training and                           Active Coherent (MAC)
 testing activities.                               sonobuoy (e.g., AN/
                                                   SSQ-125).
                                 ASW3...........  MF active towed active
                                                   acoustic
                                                   countermeasure
                                                   systems (e.g., AN/SLQ-
                                                   25).
Torpedoes (TORP): Source         TORP1..........  Lightweight torpedo
 classes associated with active                    (e.g., MK-46, MK-54,
 acoustic signals produced by                      or Anti-Torpedo
 torpedoes.                                        Torpedo).
                                 TORP2..........  Heavyweight torpedo
                                                   (e.g., MK-48).
Acoustic Modems (M): Systems     M3.............  Mid-frequency acoustic
 used to transmit data                             modems (greater than
 acoustically through water.                       190 dB).
Swimmer Detection Sonar (SD):    SD1............  High-frequency sources
 Systems used to detect divers                     with short pulse
 and submerged swimmers.                           lengths, used for the
                                                   detection of swimmers
                                                   and other objects for
                                                   the purpose of port
                                                   security.
Airguns (AG) \1\: Underwater     AG.............  Up to 60 cubic inch
 airguns are used during                           airguns (e.g., Sercel
 swimmer defense and diver                         Mini-G).
 deterrent training and testing
 activities.
------------------------------------------------------------------------
\1\ There are no Level A or Level B takes proposed from airguns.


[[Page 15393]]

 Proposed Action

    The Navy proposes to continue conducting training and testing 
activities within the MITT Study Area. The Navy has been conducting 
military readiness training and testing activities in the MITT Study 
Area for decades. Recently, these activities were analyzed in the 2010 
MIRC EIS/OEIS and the 2012 MIRC Airspace Environmental Assessment. 
These documents, among others, and the associated MMPA regulations and 
authorizations, describe the baseline of training and testing 
activities currently conducted in the Study Area. The tempo and types 
of training and testing activities have fluctuated due to the 
introduction of new technologies; the dynamic nature of international 
events; advances in warfighting doctrine and procedures; and changes in 
basing locations for ships, aircraft, and personnel (force structure 
changes). Such developments have influenced the frequency, duration, 
intensity, and location of required training and testing activities. To 
meet these requirements, the Navy is proposing an increase in the 
number of events/activities and ordnance for training and testing 
purposes.

Training and Testing

    The Navy proposes to conduct training and testing activities in the 
Study Area as described in Tables 3 and 4. Detailed information about 
each proposed activity (stressor, training or testing event, 
description, sound source, duration, and geographic location) can be 
found in the MITT DEIS/OEIS. NMFS used the detailed information in the 
MITT DEIS/OEIS to help analyze the potential impacts to marine mammals. 
Table 3 describes the annual number of impulsive source detonations 
during training and testing activities within the MITT Study Area, and 
Table 4 describes the annual number of hours or items of non-impulsive 
sources used during training and testing activities with within the 
MITT Study Area. The Navy's proposed action is an adjustment to 
existing baseline activities to accommodate the following:
     Force structure changes including the relocation of ships, 
aircraft, and personnel;
     Planned new aircraft platforms, new vessel classes, and 
new weapons systems;
     Ongoing activities that were not addressed in previous 
documentation; and
     The addition of Maritime Homeland Defense/Security Mine 
Countermeasures Exercise, as described in Table 2.4-1 of the MITT DEIS/
OEIS;
     The establishment of new danger zones or safety zones for 
site-specific military ordnance training with surface danger zones or 
hazard area extending over nearshore waters; and
     An increase in net explosive weight for explosives from 10 
lb to 20 lb at Agat Bay Mine Neutralization Site and Outer Apra Harbor 
Underwater Detonation Site.

In addition, the proposed action includes the expansion of the Study 
Area boundaries and adjustments to location, type, and tempo of 
training activities.

 Table 3--Proposed Annual Number of Impulsive Source Detonations During
            Training and Testing Activities in the Study Area
------------------------------------------------------------------------
                         Net explosive weight        Annual in-water
   Explosive class              (NEW)                  detonations
------------------------------------------------------------------------
E1..................  (0.1 lb.-0.25 lb.).......  10,140
E2..................  (0.26 lb.-0.5 lb.).......  106
E3..................  (>0.5 lb.-2.5 lb.).......  932
E4..................  (>2.5 lb.-5 lb.).........  420
E5..................  (>5 lb.-10 lb.)..........  684
E6..................  (>10 lb.-20 lb.).........  76
E8..................  (>60 lb.-100 lb.)........  16
E9..................  (>100 lb.-250 lb.).......  4
E10.................  (>250 lb.-500 lb.).......  12
E11.................  (>500 lb.-650 lb.).......  6
E12.................  (>650 lb.-2,000 lb.).....  184
------------------------------------------------------------------------


  Table 4--Proposed Annual Hours or Items of Non-Impulsive Sources Used
      During Training and Testing Activities Within the Study Area
------------------------------------------------------------------------
    Source class category         Source class           Annual use
------------------------------------------------------------------------
Low-Frequency (LF): Sources   LF4.................  123 hours.
 that produce signals less    LF5.................  11 hours.
 than 1 kHz.                  LF6.................  40 hours.
Mid-Frequency (MF): Tactical  MF1.................  1,872 hours.
 and non-tactical sources     MF2.................  625 hours.
 from 1 to 10 kHz.            MF3.................  192 hours.
                              MF4.................  214 hours.
                              MF5.................  2,588 items.
                              MF6.................  33 items.
                              MF8.................  123 hours.
                              MF9.................  47 hours.
                              MF10................  231 hours.
                              MF11................  324 hours.
                              MF12................  656 hours.
High-Frequency (HF) and Very  HF1.................  113 hours.
 High-Frequency (VHF):        HF4.................  1,060 hours.
 Tactical and non-tactical    HF5.................  336 hours.
 sources that produce         HF6.................  1,173 hours.
 signals greater than 10 kHz
 but less than 200 kHz.
Anti-Submarine Warfare        ASW1................  144 hours.
 (ASW): Tactical sources      ASW2................  660 items.
 used during anti-submarine   ASW3................  3,935 hours.
 warfare training and         ASW4................  32 items.
 testing activities.
Torpedoes (TORP): Source      TORP1...............  115 items.
 classes associated with      TORP2...............  62 items.
 active acoustic signals
 produced by torpedoes.
Acoustic Modems (M):          M3..................  112 hours.
 Transmit data acoustically
 through the water.
Swimmer Detection Sonar       SD1.................  2,341 hours.
 (SD): Used to detect divers
 and submerged swimmers.
------------------------------------------------------------------------


[[Page 15394]]

Vessels

    Vessels used as part of the proposed action include ships, 
submarines, and boats ranging in size from small, 5-m Rigid Hull 
Inflatable Boats to 333-m long aircraft carriers. Representative Navy 
vessel types, lengths, and speeds used in both training and testing 
activities are shown in Table 5. While these speeds are representative, 
some vessels operate outside of these speeds due to unique training or 
safety requirements for a given event. Examples include increased 
speeds needed for flight operations, full speed runs to test 
engineering equipment, time critical positioning needs, etc. Examples 
of decreased speeds include speeds less than 5 knots or completely 
stopped for launching small boats, certain tactical maneuvers, target 
launch or retrievals, etc.
    The number of Navy vessels in the Study Area varies based on 
training and testing schedules. Most activities include either one or 
two vessels, with an average of one vessel per activity, and last from 
a few hours up to two weeks. Multiple ships, however, can be involved 
with major training events, although ships can often operate for 
extended periods beyond the horizon and out of visual sight from each 
other. Surface and sub-surface vessel operations in the Study Area may 
result in marine mammal strikes.

 Table 5--Typical Navy Boat and Vessel Types With Length Greater Than 18
                 Meters Used Within the MITT Study Area
------------------------------------------------------------------------
                                      Example(s)
                                  (specifications in
                                    meters (m) for     Typical operating
      Vessel type (>18 m)        length, metric tons     speed (knots)
                                  (mt) for mass, and
                                   knots for speed)
------------------------------------------------------------------------
Aircraft Carrier..............  Aircraft Carrier       10 to 15.
                                 (CVN) length: 333 m
                                 beam: 41 m draft: 12
                                 m displacement:
                                 81,284 mt max.
                                 speed: 30+ knots.
Surface Combatants............  Cruiser (CG) length:   10 to 15.
                                 173 m beam: 17 m
                                 draft: 10 m
                                 displacement: 9,754
                                 mt max. speed: 30+
                                 knots.
                                Destroyer (DDG)
                                 length: 155 m beam:
                                 18 m draft: 9 m
                                 displacement: 9,648
                                 mt max. speed: 30+
                                 knots.
                                Frigate (FFG) length:
                                 136 m beam: 14 m
                                 draft: 7 m
                                 displacement: 4,166
                                 mt max. speed: 30+
                                 knots.
                                Littoral Combat Ship
                                 (LCS) length: 115 m
                                 beam: 18 m draft: 4
                                 m displacement:
                                 3,000 mt max. speed:
                                 40+ knots.
Amphibious Warfare Ships......  Amphibious Assault     10 to 15.
                                 Ship (LHA, LHD)
                                 length: 253 m beam:
                                 32 m draft: 8 m
                                 displacement: 42,442
                                 mt max. speed: 20+
                                 knots.
                                Amphibious Transport
                                 Dock (LPD) length:
                                 208 m beam: 32 m
                                 draft: 7 m
                                 displacement: 25,997
                                 mt max. speed: 20+
                                 knots.
                                Dock Landing Ship
                                 (LSD) length: 186 m
                                 beam: 26 m draft: 6
                                 m displacement:
                                 16,976 mt max.
                                 speed: 20+ knots.
Mine Warship Ship.............  Mine Countermeasures   5 to 8.
                                 Ship (MCM) length:
                                 68 m beam: 12 m
                                 draft: 4 m
                                 displacement: 1,333
                                 max. speed: 14 knots.
Submarines....................  Attack Submarine       8 to 13.
                                 (SSN) length: 115 m
                                 beam: 12 m draft: 9
                                 m displacement:
                                 12,353 mt max.
                                 speed: 20+ knots.
                                Guided Missile
                                 Submarine (SSGN)
                                 length: 171 m beam:
                                 13 m draft: 12 m
                                 displacement: 19,000
                                 mt max. speed: 20+
                                 knots.
Combat Logistics Force Ships    Fast Combat Support    8 to 12.
 \1\.                            Ship (T-AOE) length:
                                 230 m beam: 33 m
                                 draft: 12 m
                                 displacement: 49,583
                                 max. speed: 25 knots.
                                Dry Cargo/Ammunition
                                 Ship (T-AKE) length:
                                 210 m beam: 32 m
                                 draft: 9 m
                                 displacement: 41,658
                                 mt max speed: 20
                                 knots.
                                Fleet Replenishment
                                 Oilers (T-AO)
                                 length: 206 m beam:
                                 30 m draft: 11
                                 displacement: 42,674
                                 mt max. speed: 20
                                 knots.
                                Fleet Ocean Tugs (T-
                                 ATF) length: 69 m
                                 beam: 13 m draft: 5
                                 m displacement:
                                 2,297 max. speed: 14
                                 knots.
                                Joint High Speed
                                 Vessel (JHSV) \2\
                                 length: 103 m beam;
                                 28.5 m draft; 4.57 m
                                 displacement; 2,362
                                 mt max speed: 40
                                 knots.
Support Craft/Other...........  Landing Craft,         3 to 5.
                                 Utility (LCU)
                                 length: 41m beam: 9
                                 m draft: 2 m
                                 displacement: 381 mt
                                 max. speed: 11 knots.
                                Landing Craft,
                                 Mechanized (LCM)
                                 length: 23 m beam: 6
                                 m draft: 1 m
                                 displacement: 107 mt
                                 max. speed: 11
                                 knots.
Support Craft/Other             MK V Special           Variable.
 Specialized High Speed.         Operations Craft
                                 length: 25 m beam: 5
                                 m displacement: 52
                                 mt max. speed: 50
                                 knots.
------------------------------------------------------------------------
\1\ CLF vessels are not permanently homeported in the Marianas, but are
  used for various fleet support and training support events in the
  Study Area.
\2\ Typical operating speed of the Joint High Speed Vessel is 25-32
  knots.

Dates and Specified Geographic Region

    The MITT Study Area is comprised of the established ranges, 
operating areas, and special use airspace in the region of the Mariana 
Islands that are part of the MIRC, its surrounding seas, and a transit 
corridor between the Mariana Islands and the Hawaii Range Complex. The 
defined Study Area has expanded beyond the areas included in previous 
Navy authorizations to include transit routes and pierside locations. 
This expansion is not an increase in the Navy's training and testing 
area, but rather an increase in the area to be analyzed (i.e., not 
previously analyzed) under an incidental take authorization in support 
of the MITT EIS/OEIS. The MIRC, like all Navy range complexes, is an 
organized and designated set of specifically bounded geographic areas, 
which includes a water component (above and below the surface), 
airspace, and sometimes a land component.

[[Page 15395]]

Operating areas (OPAREAs) and special use airspace are established 
within each range complex. These designations are further described in 
Chapter 2 of the Navy's LOA application.
    Mariana Islands Range Complex (MIRC)--The MIRC includes land 
training areas, ocean surface areas, and subsurface areas. These areas 
extend from the waters south of Guam to north of Pagan (Commonwealth of 
the Northern Mariana Islands), and from the Pacific Ocean east of the 
Mariana Islands to the Philippine Sea to the west, encompassing 501, 
873 square nautical miles of open ocean. More detailed information on 
the MIRC, including maps, is provided in Chapter 2 of the Navy's LOA 
application (http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications).
    Transit Corridor--A transit corridor outside the bounds of the MIRC 
is also included in the Navy's request. Vessel transit corridors are 
the routes typically used by Navy assets to traverse from one area to 
another. This transit corridor is important to the Navy in that it 
provides adequate air, sea, and undersea space in which ships and 
aircraft can conduct training and some sonar maintenance and testing 
while en route between the Mariana Islands and Hawaii. The transit 
corridor is defined by the shortest distance between the MIRC and the 
Hawaii Range Complex. While in transit, vessels and aircraft would, at 
times, conduct basic and routine unit level training such as gunnery 
and sonar training as long as the training does not interfere with the 
primary objective of reaching their intended destination. Ships also 
conduct sonar maintenance, which includes active sonar transmissions.
    Pierside Locations--The Study Area also includes pierside locations 
in the Apra Harbor Naval Complex where surface ship and submarine sonar 
maintenance testing occur. These pierside locations include channels 
and routes to and from the Navy port in the Apra Harbor Naval Complex, 
and associated wharves and facilities within the Navy port and 
shipyard.
Description of Marine Mammals in the Area of the Specified Activity
    Twenty-six marine mammal species may occur in the Study Area, 
including seven mysticetes (baleen whales) and 19 odontocetes (dolphins 
and toothed whales). These species and their numbers are presented in 
Table 6 and relevant information on their status, distribution, and 
seasonal distribution (when applicable) is presented in Chapter 3 of 
the Navy's LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications).
    Species that may have once inhabited and transited the Study Area, 
but have not been sighted in recent years, include the North Pacific 
right whale (Eubalaena japonica), western subpopulation of gray whale 
(Eschrichtius robustus), short-beaked common dolphin (Delphinus 
delphis), Indo-Pacific bottlenose dolphin (Tursiops aduncus), Hawaiian 
monk seal (Monachus schauinslandi), northern elephant seal (Mirounga 
angustirostris), and dugong (Dugong dugong). These species are not 
expected to be exposed to or affected by any project activities and, 
therefore, are not discussed further.

                                    Table 6--Marine Mammals With Possible or Confirmed Presence Within the Study Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                  Study
            Common name                  Scientific name              Stock            Stock       area      Occurrence in study      ESA/MMPA status
                                                                                     abundance  abundance           area
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale.....................  Megaptera novaeangliae  Western North Pacific.     21,808         36  Rare in summer months;  Endangered/Depleted.
                                                                                                            regular in winter
                                                                                                            months.
Blue whale.........................  Balaenoptera musculus.  Central North Pacific.        N/A        842  Rare..................  Endangered/Depleted.
Fin whale..........................  Balaenoptera physalus.  ......................        N/A        359  Rare..................  Endangered/Depleted.
Sei whale..........................  Balaenoptera borealis.  ......................        N/A        166  Rare in summer months;  Endangered/Depleted.
                                                                                                            regular in winter
                                                                                                            months.
Bryde's whale......................  Balaenoptera edeni....  ......................        N/A        233  Regular...............  .....................
Minke whale........................  Balaenoptera            ......................        N/A        226  Rare in summer months;  .....................
                                      acutorostrata.                                                        regular in winter
                                                                                                            months.
Omura's whale......................  Balaenoptera omurai...  ......................        N/A        N/A  Rare..................  .....................
Sperm whale........................  Physeter macrocephalus  California, Oregon, &         971        705  Regular...............  Endangered/Depleted.
                                                              Washington.
Pygmy sperm whale..................  Kogia breviceps.......  ......................        N/A        N/A  Regular...............  .....................
Dwarf sperm whale..................  Kogia sima............  ......................        N/A        N/A  Regular...............  .....................
Killer whale.......................  Orcinus orca..........  ......................        N/A         30  Regular...............  .....................
False killer whale.................  Pseudorca crassidens..  ......................        N/A        N/A  Regular...............  .....................
Pygmy killer whale.................  Feresa attenuata......  ......................        956         78  Regular...............  .....................
Short-finned pilot whale...........  Globicephala            Japanese southern             760        118  Regular...............  .....................
                                      macrorhynchus.          stock?.
Melon-headed whale.................  Peponocephala electra.  ......................        N/A      2,455  Regular...............  .....................
Bottlenose dolphin.................  Tursiops truncatus....  ......................        N/A        323  Regular...............  .....................
Pantropical spotted dolphin........  Stenella attenuata....  ......................        N/A     12,981  Regular...............  .....................
Striped dolphin....................  Stenella coerulealba..  ......................        N/A      3,531  Regular...............  .....................
Spinner dolphin....................  Stenella longirostris   ......................        N/A        N/A  Regular...............  .....................
                                      (Stenella
                                      longirostris
                                      longirostris).
Rough-toothed dolphin..............  Steno bredanensis.....  ......................        N/A        N/A  Regular...............  .....................
Fraser's dolphin...................  Lagenodelphis hosei...  ......................        N/A        N/A  Regular...............  .....................
Risso's dolphins...................  Grampus griseus.......  ......................        N/A        N/A  Regular...............  .....................
Cuvier's beaked whale..............  Ziphius cavirostris...  ......................        N/A        N/A  Regular...............  .....................
Blainville's beaked whale..........  Mesoplodon              ......................        N/A        N/A  Regular...............  .....................
                                      densirostris.
Longman's beaked whale.............  Indopacetus pacificus.  ......................        N/A        N/A  Regular...............  .....................
Gingo-toothed beaked whale.........  Mesoplodon gindgodens.  ......................        N/A        N/A  Rare..................  .....................
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 15396]]

    Information on the status, distribution, abundance, and 
vocalizations of marine mammal species in the Study Area may be viewed 
in Chapter 4 of the Navy's LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications). Further information on the 
general biology and ecology of marine mammals is included in the MITT 
Draft EIS/OEIS. In addition, NMFS publishes annual stock assessment 
reports for marine mammals, including some stocks that occur within the 
Study Area (http://www.nmfs.noaa.gov/pr/species/mammals).

Marine Mammal Hearing and Vocalizations

    Cetaceans have an auditory anatomy that follows the basic mammalian 
pattern, with some changes to adapt to the demands of hearing 
underwater. The typical mammalian ear is divided into an outer ear, 
middle ear, and inner ear. The outer ear is separated from the inner 
ear by a tympanic membrane, or eardrum. In terrestrial mammals, the 
outer ear, eardrum, and middle ear transmit airborne sound to the inner 
ear, where the sound waves are propagated through the cochlear fluid. 
Since the impedance of water is close to that of the tissues of a 
cetacean, the outer ear is not required to transduce sound energy as it 
does when sound waves travel from air to fluid (inner ear). Sound waves 
traveling through the inner ear cause the basilar membrane to vibrate. 
Specialized cells, called hair cells, respond to the vibration and 
produce nerve pulses that are transmitted to the central nervous 
system. Acoustic energy causes the basilar membrane in the cochlea to 
vibrate. Sensory cells at different positions along the basilar 
membrane are excited by different frequencies of sound (Pickles, 1998).
    Marine mammal vocalizations often extend both above and below the 
range of human hearing; vocalizations with frequencies lower than 20 Hz 
are labeled as infrasonic and those higher than 20 kHz as ultrasonic 
(National Research Council (NRC), 2003; Figure 4-1). Measured data on 
the hearing abilities of cetaceans are sparse, particularly for the 
larger cetaceans such as the baleen whales. The auditory thresholds of 
some of the smaller odontocetes have been determined in captivity. It 
is generally believed that cetaceans should at least be sensitive to 
the frequencies of their own vocalizations. Comparisons of the anatomy 
of cetacean inner ears and models of the structural properties and the 
response to vibrations of the ear's components in different species 
provide an indication of likely sensitivity to various sound 
frequencies. The ears of small toothed whales are optimized for 
receiving high-frequency sound, while baleen whale inner ears are best 
in low to infrasonic frequencies (Ketten, 1992; 1997; 1998).
    Baleen whale vocalizations are composed primarily of frequencies 
below 1 kHz, and some contain fundamental frequencies as low as 16 Hz 
(Watkins et al., 1987; Richardson et al., 1995; Rivers, 1997; Moore et 
al., 1998; Stafford et al., 1999; Wartzok and Ketten, 1999) but can 
have harmonics that can extend as high as 24 kHz (humpback whale; Au et 
al., 2006). Clark and Ellison (2004) suggested that baleen whales use 
low-frequency sounds not only for long-range communication, but also as 
a simple form of echo ranging, using echoes to navigate and orient 
relative to physical features of the ocean. Although there is 
apparently much variation, the source levels of most baleen whale 
vocalizations lie in the range of 150-190 dB re 1 [micro]Pa at 1 m. 
Low-frequency vocalizations made by baleen whales and their 
corresponding auditory anatomy suggest that they have good low-
frequency hearing (Ketten, 2000; Houser et al., 2001; Parks et al., 
2007), although specific data on sensitivity, frequency or intensity 
discrimination, or localization abilities are lacking. Marine mammals, 
like all mammals, have typical U-shaped audiograms with frequencies on 
the edge of the auditory range being less sensitive (high threshold) 
compared to those in the middle of the auditory range where there is 
greater sensitivity (low threshold) (Fay, 1988).
    The toothed whales produce a wide variety of sounds, which include 
species-specific broadband ``clicks'' with peak energy between 10 and 
200 kHz, individually variable ``burst pulse'' click trains, and 
constant frequency or frequency-modulated (FM) whistles ranging from 4 
to 16 kHz (Wartzok and Ketten, 1999). The general consensus is that the 
tonal vocalizations (whistles) produced by toothed whales play an 
important role in maintaining contact between dispersed individuals, 
while broadband clicks are used during echolocation (Wartzok and 
Ketten, 1999). Burst pulses have also been strongly implicated in 
communication, with some scientists suggesting that they play an 
important role in agonistic encounters (McCowan and Reiss, 1995), while 
others have proposed that they represent ``emotive'' signals in a 
broader sense, possibly representing graded communication signals 
(Herzing, 1996). Sperm whales, however, are known to produce only 
clicks, which are used for both communication and echolocation 
(Whitehead, 2003). Most of the energy of toothed whale social 
vocalizations is concentrated near 10 kHz, with source levels for 
whistles as high as 100 to 180 dB re 1 [micro]Pa at 1 m (Richardson et 
al., 1995). Sperm whales produce clicks, which may be used to 
echolocate (Mullins et al., 1988), with a frequency range from less 
than 100 Hz to 30 kHz and source levels up to 230 dB re 1 [micro]Pa 1 m 
or greater (Mohl et al., 2000).

Brief Background on Sound

    An understanding of the basic properties of underwater sound is 
necessary to comprehend many of the concepts and analyses presented in 
this document. A summary is included below.
    Sound is a wave of pressure variations propagating through a medium 
(e.g., water). Pressure variations are created by compressing and 
relaxing the medium. Sound measurements can be expressed in two forms: 
intensity and pressure. Acoustic intensity is the average rate of 
energy transmitted through a unit area in a specified direction and is 
expressed in watts per square meter (W/m\2\). Acoustic intensity is 
rarely measured directly, but rather from ratios of pressures; the 
standard reference pressure for underwater sound is 1 microPascal 
([micro]Pa); for airborne sound, the standard reference pressure is 20 
[micro]Pa (Richardson et al., 1995).
    Acousticians have adopted a logarithmic scale for sound 
intensities, which is denoted in decibels (dB). Decibel measurements 
represent the ratio between a measured pressure value and a reference 
pressure value (in this case 1 [micro]Pa or, for airborne sound, 20 
[micro]Pa). The logarithmic nature of the scale means that each 10-dB 
increase is a ten-fold increase in acoustic power (and a 20-dB increase 
is then a 100-fold increase in power; and a 30-dB increase is a 1,000-
fold increase in power). A ten-fold increase in acoustic power does not 
mean that the sound is perceived as being ten times louder, however. 
Humans perceive a 10-dB increase in sound level as a doubling of 
loudness, and a 10-dB decrease in sound level as a halving of loudness. 
The term ``sound pressure level'' implies a decibel measure and a 
reference pressure that is used as the denominator of the ratio. 
Throughout this document, NMFS uses 1 microPascal (denoted re: 
1[micro]Pa) as a standard reference pressure unless noted otherwise.
    It is important to note that decibel values underwater and decibel 
values in air are not the same (different reference

[[Page 15397]]

pressures and densities/sound speeds between media) and should not be 
directly compared. Because of the different densities of air and water 
and the different decibel standards (i.e., reference pressures) in air 
and water, a sound with the same pressure level in air and in water 
would be approximately 26 dB lower in air. Thus, a sound that measures 
160 dB (re 1 [micro]Pa) underwater would have the same approximate 
effective level as a sound that is 134 dB (re 20 [micro]Pa) in air.
    Sound frequency is measured in cycles per second, or Hertz 
(abbreviated Hz), and is analogous to musical pitch; high-pitched 
sounds contain high frequencies and low-pitched sounds contain low 
frequencies. Natural sounds in the ocean span a huge range of 
frequencies: from an earthquake producing sound at 5 Hz to harbor 
porpoise clicks at 150,000 Hz (150 kHz). These sounds are so low or so 
high in pitch that humans cannot even hear them; acousticians call 
these infrasonic (typically below 20 Hz, relative to lower frequency 
bound of human hearing range) and ultrasonic (typically above 20,000 
Hz, relative to upper frequency bound of human hearing range) sounds, 
respectively. A single sound may be made up of many different 
frequencies together. Sounds made up of only a small range of 
frequencies are called ``narrowband,'' and sounds encompassing a broad 
range of frequencies are called ``broadband;'' explosives are an 
example of a broadband sound source and active tactical sonars are an 
example of a narrowband sound source.
    When considering the influence of various kinds of sound on the 
marine environment, it is necessary to understand that different groups 
of marine life are sensitive to different frequencies of sound. Based 
on available behavioral data, audiograms derived using behavioral 
protocols or auditory evoked potential (AEP) techniques, anatomical 
modeling, and other data, Southall et al. (2007) designate ``functional 
hearing groups'' for marine mammals and estimate the lower and upper 
frequencies of functional hearing of the groups. Further, the frequency 
range in which each group's hearing is estimated as being most 
sensitive is represented in the flat part of the M-weighting functions 
(which are derived from the audiograms described above; see Figure 1 in 
Southall et al., 2007) developed for each broad group. The functional 
groups and the associated frequencies for cetaceans are indicated below 
(though, again, animals are less sensitive to sounds at the outer edge 
of their functional range and most sensitive to sounds of frequencies 
within a smaller range somewhere in the middle of their functional 
hearing range):
     Low-frequency cetaceans--functional hearing is estimated 
to occur between approximately 7 Hz and 30 kHz;
     Mid-frequency cetaceans--functional hearing is estimated 
to occur between approximately 150 Hz and 160 kHz;
     High-frequency cetaceans--functional hearing is estimated 
to occur between approximately 200 Hz and 180 kHz;
    The estimated hearing range for low-frequency cetaceans has been 
extended slightly from previous analyses and what was proposed in 
Southall et al. (2007) (from 22 to 30 kHz). This decision is based on 
data from Watkins et al. (1986) for numerous mysticete species, Au et 
al. (2006) for humpback whales, an abstract from Frankel (2005) and 
paper from Lucifredi and Stein (2007) on gray whales, and an 
unpublished report (Ketten and Mountain, 2009) and abstract (Tubelli et 
al., 2012) for minke whales. As more data from more species and/or 
individuals become available, these estimated hearing ranges may 
require modification.
    When sound travels (propagates) from its source, its loudness 
decreases as the distance traveled by the sound increases (propagation 
loss, also commonly called transmission loss). Thus, the loudness of a 
sound at its source is higher than the loudness of that same sound a 
kilometer away. Acousticians often refer to the loudness of a sound at 
its source (typically referenced to one meter from the source) as the 
source level and the loudness of sound elsewhere as the received level 
(i.e., typically the receiver). For example, a humpback whale 3 km from 
a device that has a source level of 230 dB may only be exposed to sound 
that is 160 dB loud, depending on how the sound travels through water 
(e.g., spherical spreading [6 dB reduction with doubling of distance] 
was used in this example). As a result, it is important to understand 
the difference between source levels and received levels when 
discussing the loudness of sound in the ocean or its impacts on the 
marine environment.
    As sound travels from a source, its propagation in water is 
influenced by various physical characteristics, including water 
temperature, depth, salinity, and surface and bottom properties that 
cause refraction, reflection, absorption, and scattering of sound 
waves. Oceans are not homogeneous and the contribution of each of these 
individual factors is extremely complex and interrelated. The physical 
characteristics that determine the sound's speed through the water will 
change with depth, season, geographic location, and with time of day 
(as a result, in actual active sonar operations, crews will measure 
oceanic conditions, such as sea water temperature and depth, to 
calibrate models that determine the path the sonar signal will take as 
it travels through the ocean and how strong the sound signal will be at 
a given range along a particular transmission path).

Metrics Used in This Document

    This section includes a brief explanation of the two sound 
measurements (sound pressure level (SPL) and sound exposure level 
(SEL)) frequently used to describe sound levels in the discussions of 
acoustic effects in this document.
    Sound pressure level (SPL)--Sound pressure is the sound force per 
unit area, and is usually measured in micropascals ([micro]Pa), where 1 
Pa is the pressure resulting from a force of one newton exerted over an 
area of one square meter. SPL is expressed as the ratio of a measured 
sound pressure and a reference level.

SPL (in dB) = 20 log (pressure/reference pressure)

    The commonly used reference pressure level in underwater acoustics 
is 1 [micro]Pa, and the units for SPLs are dB re: 1 [micro]Pa. SPL is 
an instantaneous pressure measurement and can be expressed as the peak, 
the peak-peak, or the root mean square (rms). Root mean square 
pressure, which is the square root of the average of the square of the 
pressure of the sound signal over a given duration, is typically used 
in discussions of the effects of sounds on vertebrates and all 
references to SPL in this document refer to the root mean square. SPL 
does not take the duration of exposure into account. SPL is the 
applicable metric used in the risk continuum, which is used to estimate 
behavioral harassment takes (see Level B Harassment Risk Function 
(Behavioral Harassment) Section).
    Sound exposure level (SEL)--SEL is an energy metric that integrates 
the squared instantaneous sound pressure over a stated time interval. 
The units for SEL are dB re: 1 [micro]Pa\2\-s. Below is a simplified 
formula relating SPL to SEL.

SEL = SPL + 10log(duration in seconds)

    As applied to active sonar, the SEL includes both the SPL of a 
sonar ping and the total duration of exposure at that SPL. Longer 
duration pings and/or pings with higher SPLs will have a

[[Page 15398]]

higher SEL. If an animal is exposed to multiple pings, the SEL in each 
individual ping is summed to calculate the cumulative SEL. The 
cumulative SEL depends on the SPL, duration, and number of pings 
received. The thresholds that NMFS uses to indicate at what received 
level the onset of temporary threshold shift (TTS) and permanent 
threshold shift (PTS) in hearing are likely to occur are expressed as 
cumulative SEL.

Potential Effects of the Specified Activity on Marine Mammals

    The Navy has requested authorization for the take of marine mammals 
that may occur incidental to training and testing activities in the 
Study Area. The Navy has analyzed potential impacts to marine mammals 
from impulsive and non-impulsive sound sources and vessel strike.
    Other potential impacts to marine mammals from training and testing 
activities in the Study Area are analyzed in the Navy's MITT DEIS/OEIS, 
in consultation with NMFS as a cooperating agency, and determined to be 
unlikely to result in marine mammal harassment. Therefore, the Navy has 
not requested authorization for take of marine mammals that might occur 
incidental to other components of their proposed activities. In this 
document, NMFS analyzes the potential effects on marine mammals from 
exposure to non-impulsive sound sources (sonar and other active 
acoustic sources), impulsive sound sources (underwater), and vessel 
strikes.
    For the purpose of MMPA authorizations, NMFS' effects assessments 
serve four primary purposes: (1) To prescribe the permissible methods 
of taking (i.e., Level B harassment (behavioral harassment), Level A 
harassment (injury), or mortality, including an identification of the 
number and types of take that could occur by harassment or mortality) 
and to prescribe other means of effecting the least practicable adverse 
impact on such species or stock and its habitat (i.e., mitigation); (2) 
to determine whether the specified activity would have a negligible 
impact on the affected species or stocks of marine mammals (based on 
the likelihood that the activity would adversely affect the species or 
stock through effects on annual rates of recruitment or survival); (3) 
to determine whether the specified activity would have an unmitigable 
adverse impact on the availability of the species or stock(s) for 
subsistence uses; and (4) to prescribe requirements pertaining to 
monitoring and reporting.
    More specifically, for activities involving non-impulsive or 
impulsive sources, NMFS' analysis will identify the probability of 
lethal responses, physical trauma, sensory impairment (permanent and 
temporary threshold shifts and acoustic masking), physiological 
responses (particular stress responses), behavioral disturbance (that 
rises to the level of harassment), and social responses (effects to 
social relationships) that would be classified as a take and whether 
such take would have a negligible impact on such species or stocks. 
Vessel strikes, which have the potential to result in incidental take 
from direct injury and/or mortality, will be discussed in more detail 
in the Estimated Take of Marine Mammals section. In this section, we 
will focus qualitatively on the different ways that non-impulsive and 
impulsive sources may affect marine mammals (some of which NMFS would 
not classify as harassment). Then, in the Estimated Take of Marine 
Mammals section, we will relate the potential effects to marine mammals 
from non-impulsive and impulsive sources to the MMPA definitions of 
Level A and Level B Harassment, along with the potential effects from 
vessel strikes, and attempt to quantify those effects.

Non-Impulsive Sources

Direct Physiological Effects

    Based on the literature, there are two basic ways that non-
impulsive sources might directly result in physical trauma or damage: 
noise-induced loss of hearing sensitivity (more commonly-called 
``threshold shift'') and acoustically mediated bubble growth. 
Separately, an animal's behavioral reaction to an acoustic exposure 
might lead to physiological effects that might ultimately lead to 
injury or death, which is discussed later in the Stranding section.
    Threshold Shift (noise-induced loss of hearing)--When animals 
exhibit reduced hearing sensitivity (i.e., sounds must be louder for an 
animal to detect them) following exposure to an intense sound or sound 
for long duration, it is referred to as a noise-induced threshold shift 
(TS). An animal can experience temporary threshold shift (TTS) or 
permanent threshold shift (PTS). TTS can last from minutes or hours to 
days (i.e., there is complete recovery), can occur in specific 
frequency ranges (i.e., an animal might only have a temporary loss of 
hearing sensitivity between the frequencies of 1 and 10 kHz), and can 
be of varying amounts (for example, an animal's hearing sensitivity 
might be reduced initially by only 6 dB or reduced by 30 dB). PTS is 
permanent (i.e., there is not complete recovery), but some recovery is 
possible. PTS can also occur in a specific frequency range and amount 
as mentioned above for TTS.
    The following physiological mechanisms are thought to play a role 
in inducing auditory TS: Effects to sensory hair cells in the inner ear 
that reduce their sensitivity, modification of the chemical environment 
within the sensory cells, residual muscular activity in the middle ear, 
displacement of certain inner ear membranes, increased blood flow, and 
post-stimulatory reduction in both efferent and sensory neural output 
(Southall et al., 2007). The amplitude, duration, frequency, temporal 
pattern, and energy distribution of sound exposure all can affect the 
amount of associated TS and the frequency range in which it occurs. As 
amplitude and duration of sound exposure increase, so, generally, does 
the amount of TS, along with the recovery time. For intermittent 
sounds, less TS could occur than compared to a continuous exposure with 
the same energy (some recovery could occur between intermittent 
exposures depending on the duty cycle between sounds) (Kryter et al., 
1966; Ward, 1997). For example, one short but loud (higher SPL) sound 
exposure may induce the same impairment as one longer but softer sound, 
which in turn may cause more impairment than a series of several 
intermittent softer sounds with the same total energy (Ward, 1997). 
Additionally, though TTS is temporary, prolonged exposure to sounds 
strong enough to elicit TTS, or shorter-term exposure to sound levels 
well above the TTS threshold, can cause PTS, at least in terrestrial 
mammals (Kryter, 1985). In the case of mid- and high-frequency active 
sonar (MFAS/HFAS), animals are not expected to be exposed to levels 
high enough or durations long enough to result in PTS.
    PTS is considered auditory injury (Southall et al., 2007). 
Irreparable damage to the inner or outer cochlear hair cells may cause 
PTS; however, other mechanisms are also involved, such as exceeding the 
elastic limits of certain tissues and membranes in the middle and inner 
ears and resultant changes in the chemical composition of the inner ear 
fluids (Southall et al., 2007).
    Although the published body of scientific literature contains 
numerous theoretical studies and discussion papers on hearing 
impairments that can occur with exposure to a loud sound, only a few 
studies provide empirical information on the levels at which

[[Page 15399]]

noise-induced loss in hearing sensitivity occurs in nonhuman animals. 
For cetaceans, published data are limited to the captive bottlenose 
dolphin, beluga, harbor porpoise, and Yangtze finless porpoise 
(Finneran et al., 2000, 2002b, 2003, 2005a, 2007, 2010a, 2010b; 
Finneran and Schlundt, 2010; Lucke et al., 2009; Mooney et al., 2009a, 
2009b; Popov et al., 2011a, 2011b, 2013; Kastelein et al., 2012a; 
Schlundt et al., 2000; Nachtigall et al., 2003, 2004).
    Marine mammal hearing plays a critical role in communication 
between animals of the same species, and interpretation of 
environmental cues for purposes such as predator avoidance and prey 
capture. Depending on the degree (elevation of threshold in dB), 
duration (i.e., recovery time), and frequency range of TTS, and the 
context in which it is experienced, TTS can have effects on marine 
mammals ranging from discountable to serious (similar to those 
discussed in auditory masking, below). For example, a marine mammal may 
be able to readily compensate for a brief, relatively small amount of 
TTS in a non-critical frequency range that occurs during a time where 
ambient noise is lower and there are not as many competing sounds 
present. Alternatively, a larger amount and longer duration of TTS 
sustained during time when communication is critical for successful 
mother/calf interactions could have more serious impacts. Also, 
depending on the degree and frequency range, the effects of PTS on an 
animal could range in severity, although it is considered generally 
more serious because it is a permanent condition. Of note, reduced 
hearing sensitivity as a simple function of aging (presbycusis) has 
been observed in marine mammals, as well as humans and other taxa 
(Southall et al., 2007), so we can infer that strategies exist for 
coping with this condition to some degree, though likely not without 
cost.
    Acoustically Mediated Bubble Growth--One theoretical cause of 
injury to marine mammals is rectified diffusion (Crum and Mao, 1996), 
the process of increasing the size of a bubble by exposing it to a 
sound field. This process could be facilitated if the environment in 
which the ensonified bubbles exist is supersaturated with gas. 
Repetitive diving by marine mammals can cause the blood and some 
tissues to accumulate gas to a greater degree than is supported by the 
surrounding environmental pressure (Ridgway and Howard, 1979). The 
deeper and longer dives of some marine mammals (for example, beaked 
whales) are theoretically predicted to induce greater supersaturation 
(Houser et al., 2001b). If rectified diffusion were possible in marine 
mammals exposed to high-level sound, conditions of tissue 
supersaturation could theoretically speed the rate and increase the 
size of bubble growth. Subsequent effects due to tissue trauma and 
emboli would presumably mirror those observed in humans suffering from 
decompression sickness.
    It is unlikely that the short duration of sonar pings or explosion 
sounds would be long enough to drive bubble growth to any substantial 
size, if such a phenomenon occurs. However, an alternative but related 
hypothesis has also been suggested: stable bubbles could be 
destabilized by high-level sound exposures such that bubble growth then 
occurs through static diffusion of gas out of the tissues. In such a 
scenario the marine mammal would need to be in a gas-supersaturated 
state for a long enough period of time for bubbles to become of a 
problematic size.
    Yet another hypothesis (decompression sickness) has speculated that 
rapid ascent to the surface following exposure to a startling sound 
might produce tissue gas saturation sufficient to form nitrogen bubbles 
(Jepson et al., 2003; Fernandez et al., 2005). In this scenario, the 
rate of ascent would need to be sufficiently rapid to compromise 
behavioral or physiological protections against nitrogen bubble 
formation. Alternatively, Tyack et al. (2006) studied the deep diving 
behavior of beaked whales and concluded that: ``Using current models of 
breath-hold diving, we infer that their natural diving behavior is 
inconsistent with known problems of acute nitrogen supersaturation and 
embolism.'' Collectively, these hypotheses can be referred to as 
``hypotheses of acoustically mediated bubble growth.''
    Although theoretical predictions suggest the possibility for 
acoustically mediated bubble growth, there is considerable disagreement 
among scientists as to its likelihood (Piantadosi and Thalmann, 2004; 
Evans and Miller, 2003). Crum and Mao (1996) hypothesized that received 
levels would have to exceed 190 dB in order for there to be the 
possibility of significant bubble growth due to supersaturation of 
gases in the blood (i.e., rectified diffusion). More recent work 
conducted by Crum et al. (2005) demonstrated the possibility of 
rectified diffusion for short duration signals, but at SELs and tissue 
saturation levels that are highly improbable to occur in diving marine 
mammals. To date, energy levels (ELs) predicted to cause in vivo bubble 
formation within diving cetaceans have not been evaluated (NOAA, 
2002b). Although it has been argued that traumas from some recent 
beaked whale strandings are consistent with gas emboli and bubble-
induced tissue separations (Jepson et al., 2003), there is no 
conclusive evidence of this. However, Jepson et al. (2003, 2005) and 
Fernandez et al. (2004, 2005) concluded that in vivo bubble formation, 
which may be exacerbated by deep, long-duration, repetitive dives may 
explain why beaked whales appear to be particularly vulnerable to sonar 
exposures. Further investigation is needed to further assess the 
potential validity of these hypotheses. More information regarding 
hypotheses that attempt to explain how behavioral responses to non-
impulsive sources can lead to strandings is included in the Stranding 
and Mortality section.

Acoustic Masking

    Marine mammals use acoustic signals for a variety of purposes, 
which differ among species, but include communication between 
individuals, navigation, foraging, reproduction, and learning about 
their environment (Erbe and Farmer 2000, Tyack 2000). Masking, or 
auditory interference, generally occurs when sounds in the environment 
are louder than and of a similar frequency to, auditory signals an 
animal is trying to receive. Masking is a phenomenon that affects 
animals that are trying to receive acoustic information about their 
environment, including sounds from other members of their species, 
predators, prey, and sounds that allow them to orient in their 
environment. Masking these acoustic signals can disturb the behavior of 
individual animals, groups of animals, or entire populations.
    The extent of the masking interference depends on the spectral, 
temporal, and spatial relationships between the signals an animal is 
trying to receive and the masking noise, in addition to other factors. 
In humans, significant masking of tonal signals occurs as a result of 
exposure to noise in a narrow band of similar frequencies. As the sound 
level increases, though, the detection of frequencies above those of 
the masking stimulus decreases also. This principle is expected to 
apply to marine mammals as well because of common biomechanical 
cochlear properties across taxa.
    Richardson et al. (1995b) stated 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

[[Page 15400]]

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.
    As mentioned previously, the functional hearing ranges of 
mysticetes and odontocetes underwater all encompass the frequencies of 
the sonar sources used in the Navy's MFAS/HFAS training exercises. 
Additionally, almost all species' vocal repertoires span across the 
frequencies of these sonar sources used by the Navy. The closer the 
characteristics of the masking signal to the signal of interest, the 
more likely masking is to occur. For hull-mounted sonar, which accounts 
for the largest takes of marine mammals (because of the source strength 
and number of hours it's conducted), the pulse length and low duty 
cycle of the MFAS/HFAS signal makes it less likely that masking would 
occur as a result.

Impaired Communication

    In addition to making it more difficult for animals to perceive 
acoustic cues in their environment, anthropogenic sound presents 
separate challenges for animals that are vocalizing. When they 
vocalize, animals are aware of environmental conditions that affect the 
``active space'' of their vocalizations, which is the maximum area 
within which their vocalization can be detected before it drops to the 
level of ambient noise (Brenowitz, 2004; Brumm et al., 2004; Lohr et 
al., 2003). Animals are also aware of environmental conditions that 
affect whether listeners can discriminate and recognize their 
vocalizations from other sounds, which is more important than simply 
detecting that a vocalization is occurring (Brenowitz, 1982; Brumm et 
al., 2004; Dooling, 2004, Marten and Marler, 1977; Patricelli et al., 
2006). Most animals that vocalize have evolved with an ability to make 
adjustments to their vocalizations to increase the signal-to-noise 
ratio, active space, and recognizability/distinguishability of their 
vocalizations in the face of temporary changes in background noise 
(Brumm et al., 2004; Patricelli et al., 2006). Vocalizing marine 
mammals can make adjustments to vocalization characteristics such as 
the frequency structure, amplitude, temporal structure, and temporal 
delivery (e.g., Au et al., 1985; Di Iorio and Clark, 2009; Holt et al., 
2009; Parks et al., 2009; Parks et al., 2011).
    Many animals will combine several of these strategies to compensate 
for high levels of background noise. Anthropogenic sounds that reduce 
the signal-to-noise ratio of animal vocalizations, increase the masked 
auditory thresholds of animals listening for such vocalizations, or 
reduce the active space of an animal's vocalizations impair 
communication between animals. Most animals that vocalize have evolved 
strategies to compensate for the effects of short-term or temporary 
increases in background or ambient noise on their songs or calls. 
Although the fitness consequences of these vocal adjustments remain 
unknown, like most other trade-offs animals must make, some of these 
strategies probably come at a cost (Patricelli et al., 2006). For 
example, vocalizing more loudly in noisy environments may have 
energetic costs that decrease the net benefits of vocal adjustment and 
alter a bird's energy budget (Brumm, 2004; Wood and Yezerinac, 2006). 
Shifting songs and calls to higher frequencies may also impose 
energetic costs (Lambrechts, 1996).

Stress Responses

    Classic stress responses begin when an animal's central nervous 
system perceives a potential threat to its homeostasis. That perception 
triggers stress responses regardless of whether a stimulus actually 
threatens the animal; the mere perception of a threat is sufficient to 
trigger a stress response (Moberg, 2000; Sapolsky et al., 2005; Seyle, 
1950). Once an animal's central nervous system perceives a threat, it 
mounts a biological response or defense that consists of a combination 
of the four general biological defense responses: behavioral responses, 
autonomic nervous system responses, neuroendocrine responses, or immune 
responses.
    In the case of many stressors, an animal's first and sometimes most 
economical (in terms of biotic costs) response is behavioral avoidance 
of the potential stressor or avoidance of continued exposure to a 
stressor. An animal's second line of defense to stressors involves the 
sympathetic part of the autonomic nervous system and the classical 
``fight or flight'' response, which includes the cardiovascular system, 
the gastrointestinal system, the exocrine glands, and the adrenal 
medulla to produce changes in heart rate, blood pressure, and 
gastrointestinal activity that humans commonly associate with 
``stress.'' These responses have a relatively short duration and may 
have significant long-term effect on an animal's welfare.
    An animal's third line of defense to stressors involves its 
neuroendocrine systems; the system that has received the most study has 
been the hypothalmus-pituitary-adrenal system (also known as the HPA 
axis in mammals or the hypothalamus-pituitary-interrenal axis in fish 
and some reptiles). Unlike stress responses associated with the 
autonomic nervous system, virtually all neuroendocrine functions that 
are affected by stress--including immune competence, reproduction, 
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been 
implicated in failed reproduction (Moberg, 1987; Rivier, 1995), altered 
metabolism (Elasser et al., 2000), reduced immune competence (Blecha, 
2000), and behavioral disturbance. Increases in the circulation of 
glucocorticosteroids (cortisol, corticosterone, and aldosterone in 
marine mammals; see Romano et al., 2004) have been equated with stress 
for many years.
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and distress is the biotic cost 
of the response. During a stress response, an animal uses glycogen 
stores that can be quickly replenished once the stress is alleviated. 
In such circumstances, the cost of the stress response does 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 
functions, which impairs those functions that experience the diversion. 
For example, when mounting a stress response diverts energy away from 
growth in young animals, those animals

[[Page 15401]]

may experience stunted growth. When mounting a stress response diverts 
energy from a fetus, an animal's reproductive success and its fitness 
will suffer. In these cases, the animals will have entered a pre-
pathological or pathological state which is called ``distress'' (sensu 
Seyle 1950) or ``allostatic loading'' (sensu McEwen and Wingfield, 
2003). This pathological state will last until the animal replenishes 
its biotic reserves sufficient to restore normal function. Note that 
these examples involved a long-term (days or weeks) stress response 
exposure to stimuli.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses have also been documented 
fairly well through controlled experiments; because this physiology 
exists in every vertebrate that has been studied, it is not surprising 
that stress responses and their costs have been documented in both 
laboratory and free-living animals (for examples see, Holberton et al., 
1996; Hood et al., 1998; Jessop et al., 2003; Krausman et al., 2004; 
Lankford et al., 2005; Reneerkens et al., 2002; Thompson and Hamer, 
2000). Information has also been collected on the physiological 
responses of marine mammals to exposure to anthropogenic sounds (Fair 
and Becker, 2000; Romano et al., 2002; Wright et al., 2008). For 
example, Rolland et al. (2012) found that noise reduction from reduced 
ship traffic in the Bay of Fundy was associated with decreased stress 
in North Atlantic right whales. In a conceptual model developed by the 
Population Consequences of Disturbance (PCoD) working group, serum 
hormones were identified as possible indicators of behavioral effects 
that are translated into altered rates of reproduction and mortality. 
The Office of Naval Research hosted a workshop (Effects of Stress on 
Marine Mammals Exposed to Sound) in 2009 that focused on this very 
topic (ONR, 2009).
    Studies of other marine animals and terrestrial animals would also 
lead us to expect some marine mammals to experience physiological 
stress responses and, perhaps, physiological responses that would be 
classified as ``distress'' upon exposure to high-frequency, mid-
frequency and low-frequency sounds. For example, Jansen (1998) reported 
on the relationship between acoustic exposures and physiological 
responses that are indicative of stress responses in humans (for 
example, elevated respiration and increased heart rates). Jones (1998) 
reported on reductions in human performance when faced with acute, 
repetitive exposures to acoustic disturbance. Trimper et al. (1998) 
reported on the physiological stress responses of osprey to low-level 
aircraft noise while Krausman et al. (2004) reported on the auditory 
and physiology stress responses of endangered Sonoran pronghorn to 
military overflights. Smith et al. (2004a, 2004b), for example, 
identified noise-induced physiological transient stress responses in 
hearing-specialist fish (i.e., goldfish) that accompanied short- and 
long-term hearing losses. Welch and Welch (1970) reported physiological 
and behavioral stress responses that accompanied damage to the inner 
ears of fish and several mammals.
    Hearing is one of the primary senses marine mammals use to gather 
information about their environment and to communicate with 
conspecifics. Although empirical information on the effects of sensory 
impairment (TTS, PTS, and acoustic masking) on marine mammals remains 
limited, it seems reasonable to assume that reducing an animal's 
ability to gather information about its environment and to communicate 
with other members of its species would be stressful for animals that 
use hearing as their primary sensory mechanism. Therefore, we assume 
that acoustic exposures sufficient to trigger onset PTS or TTS would be 
accompanied by physiological stress responses because terrestrial 
animals exhibit those responses under similar conditions (NRC, 2003). 
More importantly, marine mammals might experience stress responses at 
received levels lower than those necessary to trigger onset TTS. Based 
on empirical studies of the time required to recover from stress 
responses (Moberg, 2000), we also assume that stress responses are 
likely to persist beyond the time interval required for animals to 
recover from TTS and might result in pathological and pre-pathological 
states that would be as significant as behavioral responses to TTS.

Behavioral Disturbance

    Behavioral responses to sound are highly variable and context-
specific (Ellison et al., 2012). Many 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). Individuals (of 
different age, gender, reproductive status, etc.) among most 
populations will have variable hearing capabilities, and differing 
behavioral sensitivities to sounds that will be affected by prior 
conditioning, experience, and current activities of those individuals. 
Often, specific acoustic features of the sound and contextual variables 
(i.e., proximity, duration, or recurrence of the sound or the current 
behavior that the marine mammal is engaged in or its prior experience), 
as well as entirely separate factors such as the physical presence of a 
nearby vessel, may be more relevant to the animal's response than the 
received level alone.
    Exposure of marine mammals to sound sources can result in no 
response or responses including: Increased alertness; orientation or 
attraction to a sound source; vocal modifications; cessation of 
feeding; cessation of social interaction; alteration of movement or 
diving behavior; habitat abandonment (temporary or permanent); and, in 
severe cases, panic, flight, stampede, or stranding, potentially 
resulting in death (Southall et al., 2007). A review of marine mammal 
responses to anthropogenic sound was first conducted by Richardson and 
others in 1995. A more recent review (Nowacek et al., 2007) addresses 
studies conducted since 1995 and focuses on observations where the 
received sound level of the exposed marine mammal(s) was known or could 
be estimated. The following sub-sections provide examples of behavioral 
responses that provide an idea of the variability in behavioral 
responses that would be expected given the differential sensitivities 
of marine mammal species to sound and the wide range of potential 
acoustic sources to which a marine mammal may be exposed. Estimates of 
the types of behavioral responses that could occur for a given sound 
exposure should be determined from the literature that is available for 
each species or extrapolated from closely related species when no 
information exists.
    Flight Response--A flight response is a dramatic change in normal 
movement to a directed and rapid movement away from the perceived 
location of a sound source. Relatively little information on flight 
responses of marine mammals to anthropogenic signals exist (e.g., Ford

[[Page 15402]]

and Reeves, 2008), although observations of flight responses to the 
presence of predators have occurred (Connor and Heithaus, 1996). Flight 
responses have been speculated as being a component of marine mammal 
strandings associated with sonar activities (Evans and England, 2001).
    Response to Predator--Evidence suggests that at least some marine 
mammals have the ability to acoustically identify potential predators. 
For example, harbor seals that reside in the coastal waters off British 
Columbia are frequently targeted by certain groups of killer whales, 
but not others. The seals discriminate between the calls of threatening 
and non-threatening killer whales (Deecke et al., 2002), a capability 
that should increase survivorship while reducing the energy required 
for attending to and responding to all killer whale calls. The 
occurrence of masking or hearing impairment provides a means by which 
marine mammals may be prevented from responding to the acoustic cues 
produced by their predators. Whether or not this is a possibility 
depends on the duration of the masking/hearing impairment and the 
likelihood of encountering a predator during the time that predator 
cues are impeded.
    Diving--Changes in dive behavior can vary widely. They may consist 
of increased or decreased dive times and surface intervals as well as 
changes in the rates of ascent and descent during a dive. Variations in 
dive behavior may reflect interruptions in biologically significant 
activities (e.g., foraging) or they may be of little biological 
significance. Variations in dive behavior may also expose an animal to 
potentially harmful conditions (e.g., increasing the chance of ship-
strike) or may serve as an avoidance response that enhances 
survivorship. The impact of a variation in diving resulting from an 
acoustic exposure depends on what the animal is doing at the time of 
the exposure and the type and magnitude of the response.
    Nowacek et al. (2004) reported disruptions of dive behaviors in 
foraging North Atlantic right whales when exposed to an alerting 
stimulus, an action, they noted, that could lead to an increased 
likelihood of ship strike. However, the whales did not respond to 
playbacks of either right whale social sounds or vessel noise, 
highlighting the importance of the sound characteristics in producing a 
behavioral reaction. Conversely, Indo-Pacific humpback dolphins have 
been observed to dive for longer periods of time in areas where vessels 
were present and/or approaching (Ng and Leung, 2003). In both of these 
studies, the influence of the sound exposure cannot be decoupled from 
the physical presence of a surface vessel, thus complicating 
interpretations of the relative contribution of each stimulus to the 
response. Indeed, the presence of surface vessels, their approach, and 
speed of approach, seemed to be significant factors in the response of 
the Indo-Pacific humpback dolphins (Ng and Leung, 2003). Low-frequency 
signals of the Acoustic Thermometry of Ocean Climate (ATOC) sound 
source were not found to affect dive times of humpback whales in 
Hawaiian waters (Frankel and Clark, 2000) or to overtly affect elephant 
seal dives (Costa et al., 2003). They did, however, produce subtle 
effects that varied in direction and degree among the individual seals, 
illustrating the equivocal nature of behavioral effects and consequent 
difficulty in defining and predicting them.
    Due to past incidents of beaked whale strandings associated with 
sonar operations, feedback paths are provided between avoidance and 
diving and indirect tissue effects. This feedback accounts for the 
hypothesis that variations in diving behavior and/or avoidance 
responses can possibly result in nitrogen tissue supersaturation and 
nitrogen off-gassing, possibly to the point of deleterious vascular 
bubble formation (Jepson et al., 2003). Although hypothetical, 
discussions surrounding this potential process are controversial.
    Foraging--Disruption of feeding behavior can be difficult to 
correlate with anthropogenic sound exposure, so it is usually inferred 
by observed displacement from known foraging areas, the appearance of 
secondary indicators (e.g., bubble nets or sediment plumes), or changes 
in dive behavior. Noise from seismic surveys was not found to impact 
the feeding behavior in western grey whales off the coast of Russia 
(Yazvenko et al., 2007) and sperm whales engaged in foraging dives did 
not abandon dives when exposed to distant signatures of seismic airguns 
(Madsen et al., 2006). However, Miller et al. (2009) reported buzz 
rates (a proxy for feeding) 19 percent lower during exposure to distant 
signatures of seismic airguns. Balaenopterid whales exposed to moderate 
low-frequency signals similar to the ATOC sound source demonstrated no 
variation in foraging activity (Croll et al., 2001), whereas five out 
of six North Atlantic right whales exposed to an acoustic alarm 
interrupted their foraging dives (Nowacek et al., 2004). Although the 
received sound pressure levels were similar in the latter two studies, 
the frequency, duration, and temporal pattern of signal presentation 
were different. These factors, as well as differences in species 
sensitivity, are likely contributing factors to the differential 
response. A determination of whether foraging disruptions incur fitness 
consequences will require information on or estimates of the energetic 
requirements of the individuals and the relationship between prey 
availability, foraging effort and success, and the life history stage 
of the animal. Goldbogen et al., (2013) monitored behavioral responses 
of tagged blue whales located in feeding areas when exposed simulated 
MFA sonar. Responses varied depending on behavioral context, with deep 
feeding whales being more significantly affected (i.e., generalized 
avoidance; cessation of feeding; increased swimming speeds; or directed 
travel away from the source) compared to surface feeding individuals 
that typically showed no change in behavior. Non-feeding whales also 
seemed to be affected by exposure. The authors indicate that disruption 
of feeding and displacement could impact individual fitness and health.
    Breathing--Variations in respiration naturally fluctuate 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 represent 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

[[Page 15403]]

(e.g., caused avoidance, masking, etc.), and no specific overview is 
provided here. However, social disruptions must be considered in 
context of the relationships that are affected. Long-term disruptions 
of mother/calf pairs or mating displays have the potential to affect 
the growth and survival or reproductive effort/success of individuals, 
respectively.
    Vocalizations (also see Masking Section)--Vocal changes in response 
to anthropogenic noise can occur across the repertoire of sound 
production modes used by marine mammals, such as whistling, 
echolocation click production, calling, and singing. Changes may result 
in response to a need to compete with an increase in background noise 
or may reflect an increased vigilance or startle response. For example, 
in the presence of low-frequency active sonar, humpback whales have 
been observed to increase the length of their ``songs'' (Miller et al., 
2000; Fristrup et al., 2003), possibly due to the overlap in 
frequencies between the whale song and the low-frequency active sonar. 
A similar compensatory effect for the presence of low-frequency vessel 
noise has been suggested for right whales; right whales have been 
observed to shift the frequency content of their calls upward while 
reducing the rate of calling in areas of increased anthropogenic noise 
(Parks et al., 2007). Killer whales off the northwestern coast of the 
U.S. have been observed to increase the duration of primary calls once 
a threshold in observing vessel density (e.g., whale watching) was 
reached, which has been suggested as a response to increased masking 
noise produced by the vessels (Foote et al., 2004). In contrast, both 
sperm and pilot whales potentially ceased sound production during the 
Heard Island feasibility test (Bowles et al., 1994), although it cannot 
be absolutely determined whether the inability to acoustically detect 
the animals was due to the cessation of sound production or the 
displacement of animals from the area.
    Avoidance--Avoidance is the displacement of an individual from an 
area as a result of the presence of a sound. Richardson et al., (1995) 
noted that avoidance reactions are the most obvious manifestations of 
disturbance in marine mammals. It is qualitatively different from the 
flight response, but also differs in the magnitude of the response 
(i.e., directed movement, rate of travel, etc.). Oftentimes avoidance 
is temporary, and animals return to the area once the noise has ceased. 
Longer term displacement is possible, however, which can lead to 
changes in abundance or distribution patterns of the species in the 
affected region if they do not become acclimated to the presence of the 
sound (Blackwell et al., 2004; Bejder et al., 2006; Teilmann et al., 
2006). Acute avoidance responses have been observed in captive 
porpoises and pinnipeds exposed to a number of different sound sources 
(Kastelein et al., 2001; Finneran et al., 2003; Kastelein et al., 
2006a; Kastelein et al., 2006b). Short-term avoidance of seismic 
surveys, low frequency emissions, and acoustic deterrents have also 
been noted in wild populations of odontocetes (Bowles et al., 1994; 
Goold, 1996; 1998; Stone et al., 2000; Morton and Symonds, 2002) and to 
some extent in mysticetes (Gailey et al., 2007), while longer term or 
repetitive/chronic displacement for some dolphin groups and for 
manatees has been suggested to be due to the presence of chronic vessel 
noise (Haviland-Howell et al., 2007; Miksis-Olds et al., 2007).
    Maybaum (1993) conducted sound playback experiments to assess the 
effects of MFAS on humpback whales in Hawaiian waters. Specifically, 
she exposed focal pods to sounds of a 3.3-kHz sonar pulse, a sonar 
frequency sweep from 3.1 to 3.6 kHz, and a control (blank) tape while 
monitoring behavior, movement, and underwater vocalizations. The two 
types of sonar signals (which both contained mid- and low-frequency 
components) differed in their effects on the humpback whales, but both 
resulted in avoidance behavior. The whales responded to the pulse by 
increasing their distance from the sound source and responded to the 
frequency sweep by increasing their swimming speeds and track 
linearity. In the Caribbean, sperm whales avoided exposure to mid-
frequency submarine sonar pulses, in the range of 1000 Hz to 10,000 Hz 
(IWC 2005).
    Kvadsheim et al., (2007) conducted a controlled exposure experiment 
in which killer whales fitted with D-tags were exposed to mid-frequency 
active sonar (Source A: a 1.0 second upsweep 209 dB @ 1-2 kHz every 10 
seconds for 10 minutes; Source B: with a 1.0 second upsweep 197 dB @ 6-
7 kHz every 10 seconds for 10 minutes). When exposed to Source A, a 
tagged whale and the group it was traveling with did not appear to 
avoid the source. When exposed to Source B, the tagged whales along 
with other whales that had been carousel feeding, ceased feeding during 
the approach of the sonar and moved rapidly away from the source. When 
exposed to Source B, Kvadsheim and his co-workers reported that a 
tagged killer whale seemed to try to avoid further exposure to the 
sound field by the following behaviors: Immediately swimming away 
(horizontally) from the source of the sound; engaging in a series of 
erratic and frequently deep dives that seemed to take it below the 
sound field; or swimming away while engaged in a series of erratic and 
frequently deep dives. Although the sample sizes in this study are too 
small to support statistical analysis, the behavioral responses of the 
orcas were consistent with the results of other studies.
    In 2007, the first in a series of behavioral response studies, a 
collaboration by the Navy, NMFS, and other scientists showed one beaked 
whale (Mesoplodon densirostris) responding to an MFAS playback. Tyack 
et al. (2011) indicates that the playback began when the tagged beaked 
whale was vocalizing at depth (at the deepest part of a typical feeding 
dive), following a previous control with no sound exposure. The whale 
appeared to stop clicking significantly earlier than usual, when 
exposed to mid-frequency signals in the 130-140 dB (rms) received level 
range. After a few more minutes of the playback, when the received 
level reached a maximum of 140-150 dB, the whale ascended on the slow 
side of normal ascent rates with a longer than normal ascent, at which 
point the exposure was terminated. The results are from a single 
experiment and a greater sample size is needed before robust and 
definitive conclusions can be drawn.
    Tyack et al. (2011) also indicates that Blainville's beaked whales 
appear to be sensitive to noise at levels well below expected TTS (~160 
dB re1[mu]Pa). This sensitivity is manifest by an adaptive movement 
away from a sound source. This response was observed irrespective of 
whether the signal transmitted was within the band width of MFAS, which 
suggests that beaked whales may not respond to the specific sound 
signatures. Instead, they may be sensitive to any pulsed sound from a 
point source in this frequency range. The response to such stimuli 
appears to involve maximizing the distance from the sound source.
    Results from a 2007-2008 study conducted near the Bahamas showed a 
change in diving behavior of an adult Blainville's beaked whale to 
playback of mid-frequency source and predator sounds (Boyd et al., 
2008; Tyack et al., 2011). Reaction to mid-frequency sounds included 
premature cessation of clicking and termination of a foraging dive, and 
a slower ascent rate to the surface. Preliminary results from a similar 
behavioral response study in southern California waters have been 
presented for the 2010-2011 field

[[Page 15404]]

season (Southall et al. 2011). Cuvier's beaked whale responses 
suggested particular sensitivity to sound exposure as consistent with 
results for Blainville's beaked whale. Similarly, beaked whales exposed 
to sonar during British training exercises stopped foraging (DSTL 
2007), and preliminary results of controlled playback of sonar may 
indicate feeding/foraging disruption of killer whales and sperm whales 
(Miller et al. 2011). However, studies like DeRuiter et al. (2013) 
highlight the importance of context in predicting behavioral responses 
of marine mammals to active acoustics. DeRuiter observed that beaked 
whales exposed to playbacks of U.S. tactical mid-frequency sonar from 
89 to 127 dB at close distances responded notably (i.e., altered dive 
patterns), while individuals did not behaviorally respond when exposed 
to similar received levels from actual U.S. tactical mid-frequency 
sonar operated at much further distances.
    Orientation--A shift in an animal's resting state or an attentional 
change via an orienting response represent behaviors that would be 
considered mild disruptions if occurring alone. As previously 
mentioned, the responses may co-occur with other behaviors; for 
instance, an animal may initially orient toward a sound source, and 
then move away from it. Thus, any orienting response should be 
considered in context of other reactions that may occur.
    There are few empirical studies of avoidance responses of free-
living cetaceans to MFAS. Much more information is available on the 
avoidance responses of free-living cetaceans to other acoustic sources, 
such as seismic airguns and low-frequency tactical sonar, than MFAS.

Behavioral Responses

    Southall et al. (2007) reports the results of the efforts of a 
panel of experts in acoustic research from behavioral, physiological, 
and physical disciplines that convened and reviewed the available 
literature on marine mammal hearing and physiological and behavioral 
responses to human-made sound with the goal of proposing exposure 
criteria for certain effects. This peer-reviewed compilation of 
literature is very valuable, though Southall et al. (2007) note that 
not all data are equal, some have poor statistical power, insufficient 
controls, and/or limited information on received levels, background 
noise, and other potentially important contextual variables--such data 
were reviewed and sometimes used for qualitative illustration, but were 
not included in the quantitative analysis for the criteria 
recommendations. All of the studies considered, however, contain an 
estimate of the received sound level when the animal exhibited the 
indicated response.
    In the Southall et al. (2007) publication, for the purposes of 
analyzing responses of marine mammals to anthropogenic sound and 
developing criteria, the authors differentiate between single pulse 
sounds, multiple pulse sounds, and non-pulse sounds. MFAS/HFAS sonar is 
considered a non-pulse sound. Southall et al. (2007) summarize the 
studies associated with low-frequency, mid-frequency, and high-
frequency cetacean responses to non-pulse sounds, based strictly on 
received level, in Appendix C of their article (incorporated by 
reference and summarized in the three paragraphs below).
    The studies that address responses of low-frequency cetaceans to 
non-pulse sounds include data gathered in the field and related to 
several types of sound sources (of varying similarity to MFAS/HFAS) 
including: vessel noise, drilling and machinery playback, low-frequency 
M-sequences (sine wave with multiple phase reversals) playback, 
tactical low-frequency active sonar playback, drill ships, Acoustic 
Thermometry of Ocean Climate (ATOC) source, and non-pulse playbacks. 
These studies generally indicate no (or very limited) responses to 
received levels in the 90 to 120 dB re: 1 [mu]Pa range and an 
increasing likelihood of avoidance and other behavioral effects in the 
120 to 160 dB range. As mentioned earlier, though, contextual variables 
play a very important role in the reported responses and the severity 
of effects are not linear when compared to received level. Also, few of 
the laboratory or field datasets had common conditions, behavioral 
contexts or sound sources, so it is not surprising that responses 
differ.
    The studies that address responses of mid-frequency cetaceans to 
non-pulse sounds include data gathered both in the field and the 
laboratory and related to several different sound sources (of varying 
similarity to MFAS/HFAS) including: pingers, drilling playbacks, ship 
and ice-breaking noise, vessel noise, Acoustic Harassment Devices 
(AHDs), Acoustic Deterrent Devices (ADDs), MFAS, and non-pulse bands 
and tones. Southall et al. (2007) were unable to come to a clear 
conclusion regarding the results of these studies. In some cases, 
animals in the field showed significant responses to received levels 
between 90 and 120 dB, while in other cases these responses were not 
seen in the 120 to 150 dB range. The disparity in results was likely 
due to contextual variation and the differences between the results in 
the field and laboratory data (animals typically responded at lower 
levels in the field).
    The studies that address responses of high-frequency cetaceans to 
non-pulse sounds include data gathered both in the field and the 
laboratory and related to several different sound sources (of varying 
similarity to MFAS/HFAS) including: pingers, AHDs, and various 
laboratory non-pulse sounds. All of these data were collected from 
harbor porpoises. Southall et al. (2007) concluded that the existing 
data indicate that harbor porpoises are likely sensitive to a wide 
range of anthropogenic sounds at low received levels (~ 90 to 120 dB), 
at least for initial exposures. All recorded exposures above 140 dB 
induced profound and sustained avoidance behavior in wild harbor 
porpoises (Southall et al., 2007). Rapid habituation was noted in some 
but not all studies. There is no data to indicate whether other high 
frequency cetaceans are as sensitive to anthropogenic sound as harbor 
porpoises.
    In addition to summarizing the available data, the authors of 
Southall et al. (2007) developed a severity scaling system with the 
intent of ultimately being able to assign some level of biological 
significance to a response. Following is a summary of their scoring 
system; a comprehensive list of the behaviors associated with each 
score, along with the assigned scores, may be found in the report:

 0-3 (Minor and/or brief behaviors) includes, but is not 
limited to: No response; minor changes in speed or locomotion (but with 
no avoidance); individual alert behavior; minor cessation in vocal 
behavior; minor changes in response to trained behaviors (in 
laboratory)
 4-6 (Behaviors with higher potential to affect foraging, 
reproduction, or survival) includes, but is not limited to: Moderate 
changes in speed, direction, or dive profile; brief shift in group 
distribution; prolonged cessation or modification of vocal behavior 
(duration > duration of sound), minor or moderate individual and/or 
group avoidance of sound; brief cessation of reproductive behavior; or 
refusal to initiate trained tasks (in laboratory)
 7-9 (Behaviors considered likely to affect the aforementioned 
vital rates) includes, but is not limited to: Extensive or prolonged 
aggressive behavior; moderate, prolonged or significant separation of 
females and dependent offspring with disruption

[[Page 15405]]

of acoustic reunion mechanisms; long-term avoidance of an area; 
outright panic, stampede, stranding; threatening or attacking sound 
source (in laboratory)

Potential Effects of Behavioral Disturbance

    The different ways that marine mammals respond to sound are 
sometimes indicators of the ultimate effect that exposure to a given 
stimulus will have on the well-being (survival, reproduction, etc.) of 
an animal. There is little marine mammal data quantitatively relating 
the exposure of marine mammals to sound to effects on reproduction or 
survival, though data exists for terrestrial species to which we can 
draw comparisons for marine mammals. One study related to marine 
mammals was published by Claridge as a Ph.D. thesis (Claridge, 2013). 
Claridge investigated the potential effects exposure to mid-frequency 
active sonar could have on beaked whale demographics. In summary, 
Claridge suggested that lower reproductive rates observed at the Navy's 
Atlantic Undersea Test and Evaluation Center (AUTEC), when compared to 
a control site, were due to stressors associated with frequent and 
repeated use of Navy sonar. However, the author noted that there may be 
other unknown differences between the sites. It is also important to 
note that there were some relevant shortcomings of this study. For 
example, all of the re-sighted whales during the 5-year study at both 
sites were female, which Claridge acknowledged can lead to a negative 
bias in the abundance estimation. There was also a reduced effort and 
shorter overall study period at the AUTEC site that failed to capture 
some of the emigration/immigration trends identified at the control 
site. Furthermore, Claridge assumed that the two sites were identical 
and therefore should have equal potential abundances; when in reality, 
there were notable physical differences.
    Attention is the cognitive process of selectively concentrating on 
one aspect of an animal's environment while ignoring other things 
(Posner, 1994). Because animals (including humans) have limited 
cognitive resources, there is a limit to how much sensory information 
they can process at any time. The phenomenon called ``attentional 
capture'' occurs when a stimulus (usually a stimulus that an animal is 
not concentrating on or attending to) ``captures'' an animal's 
attention. This shift in attention can occur consciously or 
subconsciously (for example, when an animal hears sounds that it 
associates with the approach of a predator) and the shift in attention 
can be sudden (Dukas, 2002; van Rij, 2007). Once a stimulus has 
captured an animal's attention, the animal can respond by ignoring the 
stimulus, assuming a ``watch and wait'' posture, or treat the stimulus 
as a disturbance and respond accordingly, which includes scanning for 
the source of the stimulus or ``vigilance'' (Cowlishaw et al., 2004).
    Vigilance is normally an adaptive behavior that helps animals 
determine the presence or absence of predators, assess their distance 
from conspecifics, or to attend cues from prey (Bednekoff and Lima, 
1998; Treves, 2000). Despite those benefits, however, vigilance has a 
cost of time; when animals focus their attention on specific 
environmental cues, they are not attending to other activities such as 
foraging. These costs have been documented best in foraging animals, 
where vigilance has been shown to substantially reduce feeding rates 
(Saino, 1994; Beauchamp and Livoreil, 1997; Fritz et al., 2002). 
Animals will spend more time being vigilant, which may translate to 
less time foraging or resting, when disturbance stimuli approach them 
more directly, remain at closer distances, have a greater group size 
(for example, multiple surface vessels), or when they co-occur with 
times that an animal perceives increased risk (for example, when they 
are giving birth or accompanied by a calf). Most of the published 
literature, however, suggests that direct approaches will increase the 
amount of time animals will dedicate to being vigilant. For example, 
bighorn sheep and Dall's sheep dedicated more time being vigilant, and 
less time resting or foraging, when aircraft made direct approaches 
over them (Frid, 2001; Stockwell et al., 1991).
    Several authors have established that long-term and intense 
disturbance stimuli can cause population declines by reducing the body 
condition of individuals that have been disturbed, followed by reduced 
reproductive success, reduced survival, or both (Daan et al., 1996; 
Madsen, 1994; White, 1983). For example, Madsen (1994) reported that 
pink-footed geese in undisturbed habitat gained body mass and had about 
a 46-percent reproductive success rate compared with geese in disturbed 
habitat (being consistently scared off the fields on which they were 
foraging) which did not gain mass and had a 17-percent reproductive 
success rate. Similar reductions in reproductive success have been 
reported for mule deer disturbed by all-terrain vehicles (Yarmoloy et 
al., 1988), caribou disturbed by seismic exploration blasts (Bradshaw 
et al., 1998), caribou disturbed by low-elevation military jet-fights 
(Luick et al., 1996), and caribou disturbed by low-elevation jet 
flights (Harrington and Veitch, 1992). Similarly, a study of elk that 
were disturbed experimentally by pedestrians concluded that the ratio 
of young to mothers was inversely related to disturbance rate (Phillips 
and Alldredge, 2000).
    The primary mechanism by which increased vigilance and disturbance 
appear to affect the fitness of individual animals is by disrupting an 
animal's time budget and, as a result, reducing the time they might 
spend foraging and resting (which increases an animal's activity rate 
and energy demand). For example, a study of grizzly bears reported that 
bears disturbed by hikers reduced their energy intake by an average of 
12 kcal/minute (50.2 x 10\3\kJ/minute), and spent energy fleeing or 
acting aggressively toward hikers (White et al. 1999). Alternately, 
Ridgway et al. (2006) reported that increased vigilance in bottlenose 
dolphins exposed to sound over a 5-day period did not cause any sleep 
deprivation or stress effects such as changes in cortisol or 
epinephrine levels.
    On a related note, many animals perform vital functions, such as 
feeding, resting, traveling, and socializing, on a diel cycle (24-hour 
cycle). Substantive behavioral reactions to noise exposure (such as 
disruption of critical life functions, displacement, or avoidance of 
important habitat) are more likely to be significant if they last more 
than one diel cycle or recur on subsequent days (Southall et al., 
2007). Consequently, a behavioral response lasting less than 1 day and 
not recurring on subsequent days is not considered particularly severe 
unless it could directly affect reproduction or survival (Southall et 
al., 2007).
    In response to the National Research Council of the National 
Academies (2005) review, the Office of Naval Research founded a working 
group to formalize the Population Consequences of Acoustic Disturbance 
(PCAD) framework. The PCAD model connects observable data through a 
series of transfer functions using a case study approach. The long-term 
goal is to improve the understanding of how effects of sound on marine 
mammals transfer between behavior and life functions and between life 
functions and vital rates of individuals. Then, this understanding of 
how disturbance can affect the vital rates of individuals will 
facilitate the further assessment of the population level effects of

[[Page 15406]]

anthropogenic sound on marine mammals by providing a quantitative 
approach to evaluate effects and the relationship between takes and 
possible changes to adult survival and/or annual recruitment. For 
example, New et al. (2013) uses energetic models to investigate the 
survival and reproduction of beaked whales. The model suggests that 
impacts to habitat quality may affect adult female beaked whales' 
ability to reproduce; and therefore, a reduction in energy intake over 
a long period of time may have the potential to impact reproduction. 
However, areas such as the Navy's Southern-California Range Complex 
continue to support high densities of beaked whales and there are no 
data to suggest a decline in the population.

Stranding and Mortality

    When a live or dead marine mammal swims or floats onto shore and 
becomes ``beached'' or incapable of returning to sea, the event is 
termed a ``stranding'' (Geraci et al., 1999; Perrin and Geraci, 2002; 
Geraci and Lounsbury, 2005; NMFS, 2007). The legal definition for a 
stranding within the U.S. is that (A) ``a marine mammal is dead and is 
(i) on a beach or shore of the United States; or (ii) in waters under 
the jurisdiction of the United States (including any navigable waters); 
or (B) a marine mammal is alive and is (i) on a beach or shore of the 
United States and unable to return to the water; (ii) on a beach or 
shore of the United States and, although able to return to the water, 
is in need of apparent medical attention; or (iii) in the waters under 
the jurisdiction of the United States (including any navigable waters), 
but is unable to return to its natural habitat under its own power or 
without assistance'' (16 U.S.C. 1421h).
    Marine mammals are known to strand for a variety of reasons, such 
as infectious agents, biotoxicosis, starvation, fishery interaction, 
ship strike, unusual oceanographic or weather events, sound exposure, 
or combinations of these stressors sustained concurrently or in series. 
However, the cause or causes of most strandings are unknown (Geraci et 
al., 1976; Eaton, 1979, Odell et al., 1980; Best, 1982). Numerous 
studies suggest that the physiology, behavior, habitat relationships, 
age, or condition of cetaceans may cause them to strand or might pre-
dispose them to strand when exposed to another phenomenon. These 
suggestions are consistent with the conclusions of numerous other 
studies that have demonstrated that combinations of dissimilar 
stressors commonly combine to kill an animal or dramatically reduce its 
fitness, even though one exposure without the other does not produce 
the same result (Chroussos, 2000; Creel, 2005; DeVries et al., 2003; 
Fair and Becker, 2000; Foley et al., 2001; Moberg, 2000; Relyea, 2005a; 
2005b, Romero, 2004; Sih et al., 2004). For reference, between 2001 and 
2009, there was an annual average of 1,400 cetacean strandings and 
4,300 pinniped strandings along the coasts of the continental U.S. and 
Alaska (NMFS, 2011).
    Several sources have published lists of mass stranding events of 
cetaceans in an attempt to identify relationships between those 
stranding events and military sonar (Hildebrand, 2004; IWC, 2005; 
Taylor et al., 2004). For example, based on a review of stranding 
records between 1960 and 1995, the International Whaling Commission 
(2005) identified ten mass stranding events of Cuvier's beaked whales 
had been reported and one mass stranding of four Baird's beaked whale. 
The IWC concluded that, out of eight stranding events reported from the 
mid-1980s to the summer of 2003, seven had been coincident with the use 
of tactical mid-frequency sonar, one of those seven had been associated 
with the use of tactical low-frequency sonar, and the remaining 
stranding event had been associated with the use of seismic airguns.
    Most of the stranding events reviewed by the International Whaling 
Commission involved beaked whales. A mass stranding of Cuvier's beaked 
whales in the eastern Mediterranean Sea occurred in 1996 (Frantzis, 
1998) and mass stranding events involving Gervais' beaked whales, 
Blainville's beaked whales, and Cuvier's beaked whales occurred off the 
coast of the Canary Islands in the late 1980s (Simmonds and Lopez-
Jurado, 1991). The stranding events that occurred in the Canary Islands 
and Kyparissiakos Gulf in the late 1990s and the Bahamas in 2000 have 
been the most intensively-studied mass stranding events and have been 
associated with naval maneuvers involving the use of tactical sonar.
    Between 1960 and 2006, 48 strandings (68 percent) involved beaked 
whales, three (4 percent) involved dolphins, and 14 (20 percent) 
involved whale species. Cuvier's beaked whales were involved in the 
greatest number of these events (48 or 68 percent), followed by sperm 
whales (seven or 10 percent), and Blainville's and Gervais' beaked 
whales (four each or 6 percent). Naval activities (not just activities 
conducted by the U.S. Navy) that might have involved active sonar are 
reported to have coincided with nine or 10 (13 to 14 percent) of those 
stranding events. Between the mid-1980s and 2003 (the period reported 
by the International Whaling Commission), we identified reports of 44 
mass cetacean stranding events, of which at least seven were coincident 
with naval exercises that were using MFAS.

Strandings Associated With Impulse Sound

    During a Navy training event on March 4, 2011 at the Silver Strand 
Training Complex in San Diego, California, three or possibly four 
dolphins were killed in an explosion. During an underwater detonation 
training event, a pod of 100 to 150 long-beaked common dolphins were 
observed moving towards the 700-yd (640.1-m) exclusion zone around the 
explosive charge, monitored by personnel in a safety boat and 
participants in a dive boat. Approximately 5 minutes remained on a 
time-delay fuse connected to a single 8.76 lb (3.97 kg) explosive 
charge (C-4 and detonation cord). Although the dive boat was placed 
between the pod and the explosive in an effort to guide the dolphins 
away from the area, that effort was unsuccessful and three long-beaked 
common dolphins near the explosion died. In addition to the three 
dolphins found dead on March 4, the remains of a fourth dolphin were 
discovered on March 7, 2011 near Ocean Beach, California (3 days later 
and approximately 11.8 mi. [19 km] from Silver Strand where the 
training event occurred), which might also have been related to this 
event. Association of the fourth stranding with the training event is 
uncertain because dolphins strand on a regular basis in the San Diego 
area. Details such as the dolphins' depth and distance from the 
explosive at the time of the detonation could not be estimated from the 
250 yd (228.6 m) standoff point of the observers in the dive boat or 
the safety boat.
    These dolphin mortalities are the only known occurrence of a U.S. 
Navy training or testing event involving impulse energy (underwater 
detonation) that caused mortality or injury to a marine mammal. Despite 
this being a rare occurrence, the Navy has reviewed training 
requirements, safety procedures, and possible mitigation measures and 
implemented changes to reduce the potential for this to occur in the 
future. Discussions of procedures associated with these and other 
training and testing events are presented in the Mitigation section of 
this document.

Strandings Associated With MFAS

    Over the past 16 years, there have been five stranding events 
coincident with military mid-frequency sonar use

[[Page 15407]]

in which exposure to sonar is believed to have been a contributing 
factor: Greece (1996); the Bahamas (2000); Madeira (2000); Canary 
Islands (2002); and Spain (2006). Additionally, in 2004, during the Rim 
of the Pacific (RIMPAC) exercises, between 150 and 200 usually pelagic 
melon-headed whales occupied the shallow waters of Hanalei Bay, Kauai, 
Hawaii for over 28 hours. NMFS determined that MFAS was a plausible, if 
not likely, contributing factor in what may have been a confluence of 
events that led to the stranding. A number of other stranding events 
coincident with the operation of mid-frequency sonar, including the 
death of beaked whales or other species (minke whales, dwarf sperm 
whales, pilot whales), have been reported; however, the majority have 
not been investigated to the degree necessary to determine the cause of 
the stranding and only one of these stranding events, the Bahamas 
(2000), was associated with exercises conducted by the U.S. Navy. Most 
recently, the Independent Scientific Review Panel investigating 
potential contributing factors to a 2008 mass stranding of melon-headed 
whales in Antsohihy, Madagascar released its final report suggesting 
that the stranding was likely initially triggered by an industry 
seismic survey. This report suggests that the operation of a commercial 
high-powered 12 kHz multi-beam echosounder during an industry seismic 
survey was a plausible and likely initial trigger that caused a large 
group of melon-headed whales to leave their typical habitat and then 
ultimately strand as a result of secondary factors such as 
malnourishment and dehydration. The report indicates that the risk of 
this particular convergence of factors and ultimate outcome is likely 
very low, but recommends that the potential be considered in 
environmental planning. Because of the association between tactical 
mid-frequency active sonar use and a small number of marine mammal 
strandings, the Navy and NMFS have been considering and addressing the 
potential for strandings in association with Navy activities for years. 
In addition to a suite of mitigation intended to more broadly minimize 
impacts to marine mammals, the Navy and NMFS have a detailed Stranding 
Response Plan that outlines reporting, communication, and response 
protocols intended both to minimize the impacts of, and enhance the 
analysis of, any potential stranding in areas where the Navy operates.
    Greece (1996)--Twelve Cuvier's beaked whales stranded atypically 
(in both time and space) along a 38.2-km strand of the Kyparissiakos 
Gulf coast on May 12 and 13, 1996 (Frantzis, 1998). From May 11 through 
May 15, the North Atlantic Treaty Organization (NATO) research vessel 
Alliance was conducting sonar tests with signals of 600 Hz and 3 kHz 
and source levels of 228 and 226 dB re: 1[mu]Pa, respectively (D'Amico 
and Verboom, 1998; D'Spain et al., 2006). The timing and location of 
the testing encompassed the time and location of the strandings 
(Frantzis, 1998).
    Necropsies of eight of the animals were performed, but were limited 
to basic external examination and sampling of stomach contents, blood, 
and skin. No ears or organs were collected, and no histological samples 
were preserved. No apparent abnormalities or wounds were found. 
Examination of photos of the animals, taken soon after their death, 
revealed that the eyes of at least four of the individuals were 
bleeding. Photos were taken soon after their death (Frantzis, 2004). 
Stomach contents contained the flesh of cephalopods, indicating that 
feeding had recently taken place (Frantzis, 1998).
    All available information regarding the conditions associated with 
this stranding event were compiled, and many potential causes were 
examined including major pollution events, prominent tectonic activity, 
unusual physical or meteorological events, magnetic anomalies, 
epizootics, and conventional military activities (International Council 
for the Exploration of the Sea, 2005a). However, none of these 
potential causes coincided in time or space with the mass stranding, or 
could explain its characteristics (International Council for the 
Exploration of the Sea, 2005a). The robust condition of the animals, 
plus the recent stomach contents, is inconsistent with pathogenic 
causes. In addition, environmental causes can be ruled out as there 
were no unusual environmental circumstances or events before or during 
this time period and within the general proximity (Frantzis, 2004).
    Because of the rarity of this mass stranding of Cuvier's beaked 
whales in the Kyparissiakos Gulf (first one in history), the 
probability for the two events (the military exercises and the 
strandings) to coincide in time and location, while being independent 
of each other, was thought to be extremely low (Frantzis, 1998). 
However, because full necropsies had not been conducted, and no 
abnormalities were noted, the cause of the strandings could not be 
precisely determined (Cox et al., 2006). A Bioacoustics Panel convened 
by NATO concluded that the evidence available did not allow them to 
accept or reject sonar exposures as a causal agent in these stranding 
events. The analysis of this stranding event provided support for, but 
no clear evidence for, the cause-and-effect relationship of tactical 
sonar training activities and beaked whale strandings (Cox et al., 
2006).
    Bahamas (2000)--NMFS and the Navy prepared a joint report 
addressing the multi-species stranding in the Bahamas in 2000, which 
took place within 24 hours of U.S. Navy ships using MFAS as they passed 
through the Northeast and Northwest Providence Channels on March 15-16, 
2000. The ships, which operated both AN/SQS-53C and AN/SQS-56, moved 
through the channel while emitting sonar pings approximately every 24 
seconds. Of the 17 cetaceans that stranded over a 36-hr period 
(Cuvier's beaked whales, Blainville's beaked whales, minke whales, and 
a spotted dolphin), seven animals died on the beach (five Cuvier's 
beaked whales, one Blainville's beaked whale, and the spotted dolphin), 
while the other 10 were returned to the water alive (though their 
ultimate fate is unknown). As discussed in the Bahamas report (DOC/DON, 
2001), there is no likely association between the minke whale and 
spotted dolphin strandings and the operation of MFAS.
    Necropsies were performed on five of the stranded beaked whales. 
All five necropsied beaked whales were in good body condition, showing 
no signs of infection, disease, ship strike, blunt trauma, or fishery 
related injuries, and three still had food remains in their stomachs. 
Auditory structural damage was discovered in four of the whales, 
specifically bloody effusions or hemorrhaging around the ears. 
Bilateral intracochlear and unilateral temporal region subarachnoid 
hemorrhage, with blood clots in the lateral ventricles, were found in 
two of the whales. Three of the whales had small hemorrhages in their 
acoustic fats (located along the jaw and in the melon).
    A comprehensive investigation was conducted and all possible causes 
of the stranding event were considered, whether they seemed likely at 
the outset or not. Based on the way in which the strandings coincided 
with ongoing naval activity involving tactical MFAS use, in terms of 
both time and geography, the nature of the physiological effects 
experienced by the dead animals, and the absence of any other acoustic 
sources, the investigation team concluded that MFAS aboard U.S. Navy 
ships that were in use during the active sonar exercise in question 
were

[[Page 15408]]

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 
whale is the only species that could potentially be affected by the 
confluence of the other factors. Based on this, NMFS believes that the 
operation of MFAS in situations where surface ducts exist, or in marine 
environments defined by steep bathymetry and/or constricted channels 
may increase the likelihood of producing a sound field with the 
potential to cause cetaceans (especially beaked whales) to strand, and 
therefore, suggests the need for increased vigilance while operating 
MFAS in these areas, especially when beaked whales (or potentially 
other deep divers) are likely present.
    Madeira, 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 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 nm (65 km) and at least 10 nm (19 
km) in length, or in an embayment. Exercises involving multiple ships 
employing MFAS near land may produce sound directed towards a channel 
or embayment that may cut off the lines of egress for marine mammals 
(Freitas, 2004).
    Canary Islands, Spain (2002)--The southeastern area within the 
Canary Islands is well known for aggregations of beaked whales due to 
its ocean depths of greater than 547 fathoms (1,000 m) within a few 
hundred meters of the coastline (Fernandez et al., 2005). On September 
24, 2002, 14 beaked whales were found stranded on Fuerteventura and 
Lanzarote Islands in the Canary Islands (International Council for 
Exploration of the Sea, 2005a). Seven whales died, while the remaining 
seven live whales were returned to deeper waters (Fernandez et al., 
2005). Four beaked whales were found stranded dead over the next three 
days either on the coast or floating offshore. These strandings 
occurred within near proximity of an international naval exercise that 
utilized MFAS and involved numerous surface warships and several 
submarines. Strandings began about 4 hours after the onset of MFAS 
activity (International Council for Exploration of the Sea, 2005a; 
Fernandez et al., 2005).
    Eight Cuvier's beaked whales, one Blainville's beaked whale, and 
one Gervais' beaked whale were necropsied, six of them within 12 hours 
of stranding (Fernandez et al., 2005). No pathogenic bacteria were 
isolated from the carcasses (Jepson et al., 2003). The animals 
displayed severe vascular congestion and hemorrhage especially around 
the tissues in the jaw, ears, brain, and kidneys, displaying marked 
disseminated microvascular hemorrhages associated with widespread fat 
emboli (Jepson et al., 2003; International Council for Exploration of 
the Sea, 2005a). Several organs contained intravascular bubbles, 
although definitive evidence of gas embolism in vivo is difficult to 
determine after death (Jepson et al., 2003). The livers of the 
necropsied animals were the most consistently affected organ, which 
contained macroscopic gas-filled cavities and had variable degrees of 
fibrotic encapsulation. In some animals, cavitary lesions had 
extensively replaced the normal tissue (Jepson et al., 2003). Stomachs 
contained a large amount of fresh and undigested contents, suggesting a 
rapid onset of disease and death (Fernandez et al., 2005). Head and 
neck lymph nodes were enlarged and congested, and parasites were found 
in the kidneys of all animals (Fernandez et al., 2005).
    The association of NATO MFAS use close in space and time to the 
beaked whale strandings, and the similarity between this stranding 
event and previous beaked whale mass strandings coincident with sonar 
use, suggests that a similar scenario and causative mechanism of 
stranding may be shared between the events. Beaked whales stranded in 
this event demonstrated brain and auditory system injuries, 
hemorrhages, and congestion in multiple organs, similar to the 
pathological findings of the Bahamas and Madeira stranding events. In 
addition, the necropsy results of Canary Islands stranding event lead 
to the hypothesis that the presence of disseminated and widespread gas 
bubbles and fat emboli were indicative of nitrogen bubble formation, 
similar to what might be expected in

[[Page 15409]]

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, 
Kauai, Hawaii for over 28 hrs. Attendees of a canoe blessing observed 
the animals entering the Bay in a single wave formation at 7 a.m. on 
July 3, 2004. The animals were observed moving back into the shore from 
the mouth of the Bay at 9 a.m. The usually pelagic animals milled in 
the shallow bay and were returned to deeper water with human assistance 
beginning at 9:30 a.m. on July 4, 2004, and were out of sight by 10:30 
a.m.
    Only one animal, a calf, was known to have died following this 
event. The animal was noted alive and alone in the Bay on the afternoon 
of July 4, 2004, and was found dead in the Bay the morning of July 5, 
2004. A full necropsy, magnetic resonance imaging, and computerized 
tomography examination were performed on the calf to determine the 
manner and cause of death. The combination of imaging, necropsy and 
histological analyses found no evidence of infectious, internal 
traumatic, congenital, or toxic factors. Cause of death could not be 
definitively determined, but it is likely that maternal separation, 
poor nutritional condition, and dehydration contributed to the final 
demise of the animal. Although we do not know when the calf was 
separated from its mother, the animals' movement into the Bay and 
subsequent milling and re-grouping may have contributed to the 
separation or lack of nursing, especially if the maternal bond was weak 
or this was an inexperienced mother with her first calf.
    Environmental factors, abiotic and biotic, were analyzed for any 
anomalous occurrences that would have contributed to the animals 
entering and remaining in Hanalei Bay. The Bay's bathymetry is similar 
to many other sites within the Hawaiian Island chain and dissimilar to 
sites that have been associated with mass strandings in other parts of 
the U.S. The weather conditions appeared to be normal for that time of 
year with no fronts or other significant features noted. There was no 
evidence of unusual distribution, occurrence of predator or prey 
species, or unusual harmful algal blooms, although Mobley et al., 2007 
suggested that the full moon cycle that occurred at that time may have 
influenced a run of squid into the Bay. Weather patterns and bathymetry 
that have been associated with mass strandings elsewhere were not found 
to occur in this instance.
    The Hanalei event was spatially and temporally correlated with 
RIMPAC. Official sonar training and tracking exercises in the Pacific 
Missile Range Facility (PMRF) warning area did not commence until 
approximately 8 a.m. on July 3 and were thus ruled out as a possible 
trigger for the initial movement into the Bay. However, six naval 
surface vessels transiting to the operational area on July 2 
intermittently transmitted active sonar (for approximately 9 hours 
total from 1:15 p.m. to 12:30 a.m.) as they approached from the south. 
The potential for these transmissions to have triggered the whales' 
movement into Hanalei Bay was investigated. Analyses with the 
information available indicated that animals to the south and east of 
Kauai could have detected active sonar transmissions on July 2, and 
reached Hanalei Bay on or before 7 a.m. on July 3. However, data 
limitations regarding the position of the whales prior to their arrival 
in the Bay, the magnitude of sonar exposure, behavioral responses of 
melon-headed whales to acoustic stimuli, and other possible relevant 
factors preclude a conclusive finding regarding the role of sonar in 
triggering this event. Propagation modeling suggests that transmissions 
from sonar use during the July 3 exercise in the PMRF warning area may 
have been detectable at the mouth of the Bay. If the animals responded 
negatively to these signals, it may have contributed to their continued 
presence in the Bay. The U.S. Navy ceased all active sonar 
transmissions during exercises in this range on the afternoon of July 
3. Subsequent to the cessation of sonar use, the animals were herded 
out of the Bay.
    While causation of this stranding event may never be unequivocally 
determined, we consider the active sonar transmissions of July 2-3, 
2004, a plausible, if not likely, contributing factor in what may have 
been a confluence of events. This conclusion is based on the following: 
(1) the evidently anomalous nature of the stranding; (2) its close 
spatiotemporal correlation with wide-scale, sustained use of sonar 
systems previously associated with stranding of deep-diving marine 
mammals; (3) the directed movement of two groups of transmitting 
vessels toward the southeast and southwest coast of Kauai; (4) the 
results of acoustic propagation modeling and an analysis of possible 
animal transit times to the Bay; and (5) the absence of any other 
compelling causative explanation. The initiation and persistence of 
this event may have resulted from an interaction of biological and 
physical factors. The biological factors may have included the presence 
of an apparently uncommon, deep-diving cetacean species (and possibly 
an offshore, non-resident group), social interactions among the animals 
before or after they entered the Bay, and/or unknown predator or prey 
conditions. The physical factors may have included the presence of 
nearby deep water, multiple vessels transiting in a directed manner 
while transmitting active sonar over a sustained period, the presence 
of surface sound ducting conditions, and/or intermittent and random 
human interactions while the animals were in the Bay.
    A separate event involving melon-headed whales and rough-toothed 
dolphins took place over the same period of time in the Northern 
Mariana Islands (Jefferson et al., 2006). 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

[[Page 15410]]

and were found to be still alive. Two other whales were discovered 
during the day on January 27, but had already died. The first three 
animals were located near the town of Mojacar and the fourth animal was 
found dead, a few kilometers north of the first three animals. From 
January 25-26, 2006, Standing NATO Response Force Maritime Group Two 
(five of seven ships including one U.S. ship under NATO Operational 
Control) had conducted active sonar training against a Spanish 
submarine within 50 nm (93 km) of the stranding site.
    Veterinary pathologists necropsied the two male and two female 
Cuvier's beaked whales. According to the pathologists, the most likely 
primary cause of this type of beaked whale mass stranding event was 
anthropogenic acoustic activities, most probably anti-submarine MFAS 
used during the military naval exercises. However, no positive acoustic 
link was established as a direct cause of the stranding. Even though no 
causal link can be made between the stranding event and naval 
exercises, certain conditions may have existed in the exercise area 
that, in their aggregate, may have contributed to the marine mammal 
strandings (Freitas, 2004): exercises were conducted in areas of at 
least 547 fathoms (1,000 m) depth near a shoreline where there is a 
rapid change in bathymetry on the order of 547 to 3,281 fathoms (1,000 
to 6,000 m) occurring across a relatively short horizontal distance 
(Freitas, 2004); multiple ships (in this instance, five) were operating 
MFAS in the same area over extended periods of time (in this case, 20 
hours) in close proximity; and exercises took place in an area 
surrounded by landmasses, or in an embayment. Exercises involving 
multiple ships employing MFAS near land may have produced sound 
directed towards a channel or embayment that may have cut off the lines 
of egress for the affected marine mammals (Freitas, 2004).

Association Between Mass Stranding Events and Exposure to MFAS

    Several authors have noted similarities between some of these 
stranding incidents: they occurred in islands or archipelagoes with 
deep water nearby, several appeared to have been associated with 
acoustic waveguides like surface ducting, and the sound fields created 
by ships transmitting MFAS (Cox et al., 2006, D'Spain et al., 2006). 
Although Cuvier's beaked whales have been the most common species 
involved in these stranding events (81 percent of the total number of 
stranded animals), other beaked whales (including Mesoplodon europeaus, 
M. densirostris, and Hyperoodon ampullatus) comprise 14 percent of the 
total. Other species (Stenella coeruleoalba, Kogia breviceps and 
Balaenoptera acutorostrata) have stranded, but in much lower numbers 
and less consistently than beaked whales.
    Based on the evidence available, however, we cannot determine 
whether (a) Cuvier's beaked whale is more prone to injury from high-
intensity sound than other species; (b) their behavioral responses to 
sound makes them more likely to strand; or (c) they are more likely to 
be exposed to MFAS than other cetaceans (for reasons that remain 
unknown). Because the association between active sonar exposures and 
marine mammals mass stranding events is not consistent--some marine 
mammals strand without being exposed to sonar and some sonar 
transmissions are not associated with marine mammal stranding events 
despite their co-occurrence--other risk factors or a grouping of risk 
factors probably contribute to these stranding events.

Behaviorally Mediated Responses to MFAS That May Lead to Stranding

    Although the confluence of Navy MFAS with the other contributory 
factors noted in the report was identified as the cause of the 2000 
Bahamas stranding event, the specific mechanisms that led to that 
stranding (or the others) are not understood, and there is uncertainty 
regarding the ordering of effects that led to the stranding. It is 
unclear whether beaked whales were directly injured by sound (e.g., 
acoustically mediated bubble growth, as addressed above) prior to 
stranding or whether a behavioral response to sound occurred that 
ultimately caused the beaked whales to be injured and strand. 
Similarly, with regards to the aforementioned Madagascar stranding, a 
review panel suggests that a 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.
    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: 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

[[Page 15411]]

protect marine mammals against nitrogen gas supersaturation (alveolar 
collapse and elective circulation; Kooyman et al., 1972; Ridgway and 
Howard, 1979), Ridgway and Howard (1979) reported that bottlenose 
dolphins that were trained to dive repeatedly had muscle tissues that 
were substantially supersaturated with nitrogen gas. Houser et al. 
(2001) used these data to model the accumulation of nitrogen gas within 
the muscle tissue of other marine mammal species and concluded that 
cetaceans that dive deep and have slow ascent or descent speeds would 
have tissues that are more supersaturated with nitrogen gas than other 
marine mammals. Based on these data, Cox et al. (2006) hypothesized 
that a critical dive sequence might make beaked whales more prone to 
stranding in response to acoustic exposures. The sequence began with 
(1) very deep (to depths as deep as 2 kilometers) and long (as long as 
90 minutes) foraging dives; (2) relatively slow, controlled ascents; 
and (3) a series of ``bounce'' dives between 100 and 400 m in depth 
(also see Zimmer and Tyack, 2007). They concluded that acoustic 
exposures that disrupted any part of this dive sequence (for example, 
causing beaked whales to spend more time at surface without the bounce 
dives that are necessary to recover from the deep dive) could produce 
excessive levels of nitrogen supersaturation in their tissues, leading 
to gas bubble and emboli formation that produces pathologies similar to 
decompression sickness.
    Zimmer and Tyack (2007) modeled nitrogen tension and bubble growth 
in several tissue compartments for several hypothetical dive profiles 
and concluded that repetitive shallow dives (defined as a dive where 
depth does not exceed the depth of alveolar collapse, approximately 72 
m for Ziphius), perhaps as a consequence of an extended avoidance 
reaction to sonar sound, could pose a risk for decompression sickness 
and that this risk should increase with the duration of the response. 
Their models also suggested that unrealistically rapid rates of ascent 
from normal dive behaviors are unlikely to result in supersaturation to 
the extent that bubble formation would be expected. Tyack et al. (2006) 
suggested that emboli observed in animals exposed to mid-frequency 
range sonar (Jepson et al., 2003; Fernandez et al., 2005) could stem 
from a behavioral response that involves repeated dives shallower than 
the depth of lung collapse. Given that nitrogen gas accumulation is a 
passive process (i.e. nitrogen is metabolically inert), a bottlenose 
dolphin was trained to repetitively dive a profile predicted to elevate 
nitrogen saturation to the point that nitrogen bubble formation was 
predicted to occur. However, inspection of the vascular system of the 
dolphin via ultrasound did not demonstrate the formation of 
asymptomatic nitrogen gas bubbles (Houser et al., 2007). Baird et al. 
(2008), in a beaked whale tagging study off Hawaii, showed that deep 
dives are equally common during day or night, but ``bounce dives'' are 
typically a daytime behavior, possibly associated with visual predator 
avoidance. This may indicate that ``bounce dives'' are associated with 
something other than behavioral regulation of dissolved nitrogen 
levels, which would be necessary day and night.
    If marine mammals respond to a Navy vessel that is transmitting 
active sonar in the same way that they might respond to a predator, 
their probability of flight responses should increase when they 
perceive that Navy vessels are approaching them directly, because a 
direct approach may convey detection and intent to capture (Burger and 
Gochfeld, 1981, 1990; Cooper, 1997, 1998). The probability of flight 
responses should also increase as received levels of active sonar 
increase (and the ship is, therefore, closer) and as ship speeds 
increase (that is, as approach speeds increase). For example, the 
probability of flight responses in Dall's sheep (Ovis dalli dalli) 
(Frid 2001a, b), ringed seals (Phoca hispida) (Born et al., 1999), 
Pacific brant (Branta bernic nigricans) and Canada geese (B. 
Canadensis) increased as a helicopter or fixed-wing aircraft approached 
groups of these animals more directly (Ward et al., 1999). Bald eagles 
(Haliaeetus leucocephalus) perched on trees alongside a river were also 
more likely to flee from a paddle raft when their perches were closer 
to the river or were closer to the ground (Steidl and Anthony, 1996).
    Despite the many theories involving bubble formation (both as a 
direct cause of injury (see Acoustically Mediated Bubble Growth 
Section) and an indirect cause of stranding (See Behaviorally Mediated 
Bubble Growth Section)), Southall et al., (2007) summarizes that there 
is either scientific disagreement or a lack of information regarding 
each of the following important points: (1) Received acoustical 
exposure conditions for animals involved in stranding events; (2) 
pathological interpretation of observed lesions in stranded marine 
mammals; (3) acoustic exposure conditions required to induce such 
physical trauma directly; (4) whether noise exposure may cause 
behavioral reactions (such as atypical diving behavior) that 
secondarily cause bubble formation and tissue damage; and (5) the 
extent the post mortem artifacts introduced by decomposition before 
sampling, handling, freezing, or necropsy procedures affect 
interpretation of observed lesions. However, studies like DeRuiter et 
al. (2013) highlight the importance of context in predicting behavioral 
responses of marine mammals to active acoustics. DeRuiter observed that 
beaked whales exposed to playbacks of U.S. tactical mid-frequency sonar 
from 89 to 127 dB at close distances responded notably (i.e., altered 
dive patterns), while individuals did not behaviorally respond when 
exposed to similar received levels from actual U.S. tactical mid-
frequency sonar operated at much further distances.

Impulsive Sources

    Underwater explosive detonations send a shock wave and sound energy 
through the water and can release gaseous by-products, create an 
oscillating bubble, or cause a plume of water to shoot up from the 
water surface. The shock wave and accompanying noise are of most 
concern to marine animals. Depending on the intensity of the shock wave 
and size, location, and depth of the animal, an animal can be injured, 
killed, suffer non-lethal physical effects, experience hearing related 
effects with or without behavioral responses, or exhibit temporary 
behavioral responses or tolerance from hearing the blast sound. 
Generally, exposures to higher levels of impulse and pressure levels 
result in greater impacts to an individual animal.
    Injuries resulting from a shock wave take place at boundaries 
between tissues of different densities. Different velocities are 
imparted to tissues of different densities, and this can lead to their 
physical disruption. Blast effects are greatest at the gas-liquid 
interface (Landsberg, 2000). Gas-containing organs, particularly the 
lungs and gastrointestinal tract, are especially susceptible (Goertner, 
1982; Hill, 1978; Yelverton et al., 1973). In addition, gas-containing 
organs including the nasal sacs, larynx, pharynx, trachea, and lungs 
may be damaged by compression/expansion caused by the oscillations of 
the blast gas bubble (Reidenberg and Laitman, 2003). Intestinal walls 
can bruise or rupture, with subsequent hemorrhage and escape of gut 
contents into the body cavity. Less severe gastrointestinal tract 
injuries include contusions, petechiae (small red or purple spots 
caused by bleeding in the

[[Page 15412]]

skin), and slight hemorrhaging (Yelverton et al., 1973).
    Because the ears are the most sensitive to pressure, they are the 
organs most sensitive to injury (Ketten, 2000). Sound-related damage 
associated with sound energy from detonations can be theoretically 
distinct from injury from the shock wave, particularly farther from the 
explosion. If a noise is audible to an animal, it has the potential to 
damage the animal's hearing by causing decreased sensitivity (Ketten, 
1995). Sound-related trauma can be lethal or sublethal. Lethal impacts 
are those that result in immediate death or serious debilitation in or 
near an intense source and are not, technically, pure acoustic trauma 
(Ketten, 1995). Sublethal impacts include hearing loss, which is caused 
by exposures to perceptible sounds. Severe damage (from the shock wave) 
to the ears includes tympanic membrane rupture, fracture of the 
ossicles, damage to the cochlea, hemorrhage, and cerebrospinal fluid 
leakage into the middle ear. Moderate injury implies partial hearing 
loss due to tympanic membrane rupture and blood in the middle ear. 
Permanent hearing loss also can occur when the hair cells are damaged 
by one very loud event, as well as by prolonged exposure to a loud 
noise or chronic exposure to noise. The level of impact from blasts 
depends on both an animal's location and, at outer zones, on its 
sensitivity to the residual noise (Ketten, 1995).
    There have been fewer studies addressing the behavioral effects of 
explosives on marine mammals compared to MFAS/HFAS. However, though the 
nature of the sound waves emitted from an explosion are different (in 
shape and rise time) from MFAS/HFAS, we still anticipate the same sorts 
of behavioral responses to result from repeated explosive detonations 
(a smaller range of likely less severe responses (i.e., not rising to 
the level of MMPA harassment) would be expected to occur as a result of 
exposure to a single explosive detonation that was not powerful enough 
or close enough to the animal to cause TTS or injury).

Vessel Strike

    Commercial and Navy ship strikes of cetaceans can cause major 
wounds, which may lead to the death of the animal. An animal at the 
surface could be struck directly by a vessel, a surfacing animal could 
hit the bottom of a vessel, or an animal just below the surface could 
be cut by a vessel's propeller. The severity of injuries typically 
depends on the size and speed of the vessel (Knowlton and Kraus, 2001; 
Laist et al., 2001; Vanderlaan and Taggart, 2007). The most vulnerable 
marine mammals are those that spend extended periods of time at the 
surface in order to restore oxygen levels within their tissues after 
deep dives (e.g., the sperm whale). In addition, some baleen whales, 
such as the North Atlantic right whale, seem generally unresponsive to 
vessel sound, making them more susceptible to vessel collisions 
(Nowacek et al., 2004). These species are primarily large, slow moving 
whales. Smaller marine mammals (e.g., bottlenose dolphin) move quickly 
through the water column and are often seen riding the bow wave of 
large ships. Marine mammal responses to vessels may include avoidance 
and changes in dive pattern (NRC, 2003).
    An examination of all known ship strikes from all shipping sources 
(civilian and military) indicates vessel speed is a principal factor in 
whether a vessel strike results in death (Knowlton and Kraus, 2001; 
Laist et al., 2001; Jensen and Silber, 2003; Vanderlaan and Taggart, 
2007). In assessing records in which vessel speed was known, Laist et 
al. (2001) found a direct relationship between the occurrence of a 
whale strike and the speed of the vessel involved in the collision. The 
authors concluded that most deaths occurred when a vessel was traveling 
in excess of 13 knots.
    Jensen and Silber (2003) detailed 292 records of known or probable 
ship strikes of all large whale species from 1975 to 2002. Of these, 
vessel speed at the time of collision was reported for 58 cases. Of 
these cases, 39 (or 67 percent) resulted in serious injury or death (19 
of those resulted in serious injury as determined by blood in the 
water, propeller gashes or severed tailstock, and fractured skull, jaw, 
vertebrae, hemorrhaging, massive bruising or other injuries noted 
during necropsy and 20 resulted in death). Operating speeds of vessels 
that struck various species of large whales ranged from 2 to 51 knots. 
The majority (79 percent) of these strikes occurred at speeds of 13 
knots or greater. The average speed that resulted in serious injury or 
death was 18.6 knots. Pace and Silber (2005) found that the probability 
of death or serious injury increased rapidly with increasing vessel 
speed. Specifically, the predicted probability of serious injury or 
death increased from 45 to 75 percent as vessel speed increased from 10 
to 14 knots, and exceeded 90 percent at 17 knots. Higher speeds during 
collisions result in greater force of impact, but higher speeds also 
appear to increase the chance of severe injuries or death by pulling 
whales toward the vessel. Computer simulation modeling showed that 
hydrodynamic forces pulling whales toward the vessel hull increase with 
increasing speed (Clyne, 1999; Knowlton et al., 1995).
    The Jensen and Silber (2003) report notes that the database 
represents a minimum number of collisions, because the vast majority 
probably goes undetected or unreported. In contrast, Navy vessels are 
likely to detect any strike that does occur, and they are required to 
report all ship strikes involving marine mammals. Overall, the 
percentages of Navy traffic relative to overall large shipping traffic 
are very small (on the order of 2 percent).
    There are no records of any Navy vessel strikes to marine mammals 
in the Study Area. There have been Navy strikes of large whales in 
areas outside the Study Area, such as Hawaii and Southern California. 
However, these areas differ significantly from the Study Area given 
that both Hawaii and Southern California have a much higher number of 
Navy vessel activities and appear to have much higher densities of 
large whales.

Anticipated Effects on Marine Mammal Habitat

    The Navy's proposed training and testing activities could 
potentially affect marine mammal habitat through the introduction of 
sound into the water column, impacts to the prey species of marine 
mammals, bottom disturbance, or changes in water quality. Each of these 
components was considered in chapter 3 of the MITT DEIS/OEIS. Based on 
the information below, the impacts to marine mammals and the food 
sources that they use are not expected to cause significant or long-
term consequences for individual marine mammals or their populations.

Important Marine Mammal Habitat

    No critical habitat for marine mammals species protected under the 
ESA has been designated in the MITT Study Area. There are also no known 
specific breeding or calving areas for marine mammals within the MITT 
Study Area.

Expected Effects on Habitat

    Unless the sound source or explosive detonation is stationary and/
or continuous over a long duration in one area, the effects of the 
introduction of sound into the environment are generally considered to 
have a less severe impact on marine mammal habitat than the physical 
alteration of the habitat. Acoustic exposures are not expected to 
result in long-term physical alteration of the water column or bottom 
topography, as the occurrences are of

[[Page 15413]]

limited duration and are intermittent in time. Surface vessels 
associated with the activities are present in limited duration and are 
intermittent as they are continuously and relatively rapidly moving 
through any given area. Most of the high-explosive military expended 
materials would detonate at or near the water surface. Only bottom-laid 
explosives are likely to affect bottom substrate; habitat used for 
underwater detonations and seafloor device placement would primarily be 
soft-bottom sediment. Once on the seafloor, military expended material 
would likely be colonized by benthic organisms because the materials 
would serve as anchor points in the shifting bottom substrates, similar 
to a reef. The surface area of bottom substrate affected would make up 
a very small percentage of the total training and testing area 
available in the MITT Study Area.

Effects on Marine Mammal Prey

    Invertebrates--Marine invertebrate distribution in the MITT Study 
Area is influenced by habitat, ocean currents, and water quality 
factors such as temperature, salinity, and nutrient content (Levinton 
2009). The distribution of invertebrates is also influenced by their 
distance from the equator (latitude); in general, the number of marine 
invertebrate species increases toward the equator (Macpherson 2002). 
The higher number of species (diversity) and abundance of marine 
invertebrates in coastal habitats, compared with the open ocean, is a 
result of more nutrient availability from terrestrial environments and 
the variety of habitats and substrates found in coastal waters 
(Levinton 2009).
    The Mariana nearshore environment is characterized by extensive 
coral bottom and coral reef areas. In general, the coral reefs of the 
Marianas have a lower coral diversity compared to other reefs in the 
northwestern Pacific, but a higher density than the reefs of Hawaii. 
Numerous corals, hydroids, jellyfish, worms, mollusks, arthropods, 
echinoderms, sponges, and protozoa are found throughout the Study Area. 
Detailed information on species presence and characteristics is 
provided in Chapter 3 of the MITT DEIS/OEIS.
    Very little is known about sound detection and use of sound by 
aquatic invertebrates (Budelmann 2010; Montgomery et al., 2006; Popper 
et al., 2001). Organisms may detect sound by sensing either the 
particle motion or pressure component of sound, or both. Aquatic 
invertebrates probably do not detect pressure since many are generally 
the same density as water and few, if any, have air cavities that would 
function like the fish swim bladder in responding to pressure 
(Budelmann 2010; Popper et al., 2001). Many marine invertebrates, 
however, have ciliated ``hair'' cells that may be sensitive to water 
movements, such as those caused by currents or water particle motion 
very close to a sound source (Budelmann 2010; Mackie and Singla 2003). 
These cilia may allow invertebrates to sense nearby prey or predators 
or help with local navigation. Marine invertebrates may produce and use 
sound in territorial behavior, to deter predators, to find a mate, and 
to pursue courtship (Popper et al., 2001).
    Both behavioral and auditory brainstem response studies suggest 
that crustaceans may sense sounds up to three kilohertz (kHz), but best 
sensitivity is likely below 200 Hz (Lovell et al., 2005; Lovell et al. 
2006; Goodall et al. 1990). Most cephalopods (e.g., octopus and squid) 
likely sense low-frequency sound below 1,000 Hz, with best 
sensitivities at lower frequencies (Budelmann 2010; Mooney et al., 
2010; Packard et al., 1990). A few cephalopods may sense higher 
frequencies up to 1,500 Hz (Hu et al., 2009). Squid did not respond to 
toothed whale ultrasonic echolocation clicks at sound pressure levels 
ranging from 199 to 226 dB re 1 [mu]Pa peak-to-peak, likely because 
these clicks were outside of squid hearing range (Wilson et al., 2007). 
However, squid exhibited alarm responses when exposed to broadband 
sound from an approaching seismic airgun with received levels exceeding 
145 to 150 dB re 1 [mu]Pa root mean square (McCauley et al., 2000b).
    Little information is available on the potential impacts on marine 
invertebrates of exposure to sonar, explosions, and other sound-
producing activities. It is expected that most marine invertebrates 
would not sense mid- or high-frequency sounds, distant sounds, or 
aircraft noise transmitted through the air-water interface. Most marine 
invertebrates would not be close enough to intense sound sources, such 
as some sonars, to potentially experience impacts to sensory 
structures. Any marine invertebrate capable of sensing sound may alter 
its behavior if exposed to non-impulsive sound, although it is unknown 
if responses to non-impulsive sounds occur. Continuous noise, such as 
from vessels, may contribute to masking of relevant environmental 
sounds, such as reef noise. Because the distance over which most marine 
invertebrates are expected to detect any sounds is limited and vessels 
would be in transit, any sound exposures with the potential to cause 
masking or behavioral responses would be brief and long-term impacts 
are not expected. Although non-impulsive underwater sounds produced 
during training and testing activities may briefly impact individuals, 
intermittent exposures to non-impulsive sounds are not expected to 
impact survival, growth, recruitment, or reproduction of widespread 
marine invertebrate populations.
    Most detonations would occur greater than 3 nm from shore. As water 
depth increases away from shore, benthic invertebrates would be less 
likely to be impacted by detonations at or near the surface. In 
addition, detonations near the surface would release a portion of their 
explosive energy into the air, reducing the explosive impacts in the 
water. Some marine invertebrates may be sensitive to the low-frequency 
component of impulsive sound, and they may exhibit startle reactions or 
temporary changes in swim speed in response to an impulsive exposure. 
Because exposures are brief, limited in number, and spread over a large 
area, no long-term impacts due to startle reactions or short-term 
behavioral changes are expected. Although individual marine 
invertebrates may be injured or killed during an explosion, no long-
term impacts on the survival, growth, recruitment, or reproduction of 
marine invertebrate populations are expected.
    Fish--Fish are not distributed uniformly throughout the MITT Study 
Area, but are closely associated with a variety of habitats. Some 
species range across thousands of square miles while others have small 
home ranges and restricted distributions (Helfman et al., 2009). There 
are approximately 1,106 marine fish species in the coastal zone of the 
Study Area. Detailed information on species presence, distribution, and 
characteristics are provided in chapter 3 of the MITT DEIS/OEIS.
    All fish have two sensory systems to detect sound in the water: the 
inner ear, which functions very much like the inner ear in other 
vertebrates, and the lateral line, which consists of a series of 
receptors along the fish's body (Popper 2008). The inner ear generally 
detects relatively higher-frequency sounds, while the lateral line 
detects water motion at low frequencies (below a few hundred Hz) 
(Hastings and Popper 2005a). Although hearing capability data only 
exist for fewer than 100 of the 32,000 fish species, current data 
suggest that most species of fish detect sounds from 50 to 1,000 Hz, 
with few fish hearing sounds above 4 kHz (Popper 2008). It is believed 
that most fish have their best hearing sensitivity from 100 to 400 Hz 
(Popper 2003b). Additionally,

[[Page 15414]]

some clupeids (shad in the subfamily Alosinae) possess ultrasonic 
hearing (i.e., able to detect sounds above 100,000 Hz) (Astrup 1999). 
Permanent hearing loss, or permanent threshold shift has not been 
documented in fish. The sensory hair cells of the inner ear in fish can 
regenerate after they are damaged, unlike in mammals where sensory hair 
cells loss is permanent (Lombarte et al. 1993; Smith et al. 2006). As a 
consequence, any hearing loss in fish may be as temporary as the 
timeframe required to repair or replace the sensory cells that were 
damaged or destroyed (e.g., Smith et al. 2006).
    Potential direct injuries from non-impulsive sound sources, such as 
sonar, are unlikely because of the relatively lower peak pressures and 
slower rise times than potentially injurious sources such as 
explosives. Non-impulsive sources also lack the strong shock waves 
associated with an explosion. Therefore, direct injury is not likely to 
occur from exposure to non-impulsive sources such as sonar, vessel 
noise, or subsonic aircraft noise. Only a few fish species are able to 
detect high-frequency sonar and could have behavioral reactions or 
experience auditory masking during these activities. These effects are 
expected to be transient and long-term consequences for the population 
are not expected. MFAS is unlikely to impact fish species because most 
species are unable to detect sounds in this frequency range, and 
vessels operating MFAS would be transiting an area (not stationary). 
While a large number of fish species may be able to detect low-
frequency sonar and other active acoustic sources, low-frequency active 
usage is rare and mostly conducted in deeper waters. Overall effects to 
fish from would be localized and infrequent.
    Physical effects from pressure waves generated by underwater sounds 
(e.g. underwater explosions) could potentially affect fish within 
proximity of training or testing activities. In particular, the rapid 
oscillation between high- and low-pressure peaks has the potential to 
burst the swim bladders and other gas-containing organs of fish (Keevin 
and Hemen 1997). Sublethal effects, such as changes in behavior of 
fish, have been observed in several occasions as a result of noise 
produced by explosives (National Research Council of the National 
Academies 2003; Wright 1982). If an individual fish were repeatedly 
exposed to sounds from underwater explosions that caused alterations in 
natural behavioral patterns or physiological stress, these impacts 
could lead to long-term consequences for the individual such as reduced 
survival, growth, or reproductive capacity. However, the time scale of 
individual explosions is very limited, and training exercises involving 
explosions are dispersed in space and time. Consequently, repeated 
exposure of individual fish to sounds from underwater explosions is not 
likely and most acoustic effects are expected to be short-term and 
localized. Long-term consequences for populations would not be 
expected. A limited number of fish may be killed in the immediate 
proximity of underwater detonations and additional fish may be injured. 
Short-term effects such as masking, stress, behavioral change, and 
hearing threshold shifts are also expected during underwater 
detonations. However, given the relatively small area that would be 
affected, and the abundance and distribution of the species concerned, 
no population-level effects are expected. The abundances of various 
fish and invertebrates near the detonation point of an explosion could 
be altered for a few hours before animals from surrounding areas 
repopulate the area; however, these populations would be replenished as 
waters near the sound source are mixed with adjacent waters.

Marine Mammal Avoidance

    Marine mammals may be temporarily displaced from areas where Navy 
training and testing is occurring, but the area should be utilized 
again after the activities have ceased. Avoidance of an area can help 
the animal avoid further acoustic effects by avoiding or reducing 
further exposure. The intermittent or short duration of many activities 
should prevent animals from being exposed to stressors on a continuous 
basis. In areas of repeated and frequent acoustic disturbance, some 
animals may habituate or learn to tolerate the new baseline or 
fluctuations in noise level. While some animals may not return to an 
area, or may begin using an area differently due to training and 
testing activities, most animals are expected to return to their usual 
locations and behavior.

Other Expected Effects

    Other sources that may affect marine mammal habitat were considered 
in the MITT DEIS/OEIS and potentially include the introduction of fuel, 
debris, ordnance, and chemical residues into the water column. The 
majority of high-order explosions would occur at or above the surface 
of the ocean, and would have no impacts on sediments and minimal 
impacts on water quality. While disturbance or strike from an item 
falling through the water column is possible, it is unlikely because 
(1) objects sink slowly, (2) most projectiles are fired at targets (and 
hit those targets), and (3) animals are generally widely dispersed 
throughout the water column and over the MITT Study Area. Chemical, 
physical, or biological changes in sediment or water quality would not 
be detectable. In the event of an ordnance failure, the energetic 
materials it contained would remain mostly intact. The explosive 
materials in failed ordnance items and metal components from training 
and testing would leach slowly and would quickly disperse in the water 
column. Chemicals from other explosives would not be introduced into 
the water column in large amounts and all torpedoes would be recovered 
following training and testing activities, reducing the potential for 
chemical concentrations to reach levels that can affect sediment 
quality, water quality, or benthic habitats.

Proposed Mitigation

    In order to issue an incidental take authorization under section 
101(a)(5)(A) of the MMPA, NMFS must set forth the ``permissible methods 
of taking pursuant to such activity, and other means of effecting the 
least practicable adverse impact on such species or stock and its 
habitat, paying particular attention to rookeries, mating grounds, and 
areas of similar significance.'' NMFS' duty under this ``least 
practicable adverse impact'' standard is to prescribe mitigation 
reasonably designed to minimize, to the extent practicable, any adverse 
population-level impacts, as well as habitat impacts. While population-
level impacts can be minimized only be reducing impacts on individual 
marine mammals, not all takes translate to population-level impacts. 
NMFS' objective under the ``least practicable adverse impact'' standard 
is to design mitigation targeting those impacts on individual marine 
mammals that are most likely to lead to adverse population-level 
effects.
    The NDAA of 2004 amended the MMPA as it relates to military-
readiness activities and the ITA process such that ``least practicable 
adverse impact'' shall include consideration of personnel safety, 
practicality of implementation, and impact on the effectiveness of the 
``military readiness activity.'' The training and testing activities 
described in the Navy's LOA application are considered military 
readiness activities.
    NMFS reviewed the proposed activities and the proposed mitigation 
measures as described in the Navy's LOA application to determine if 
they would result in the least practicable

[[Page 15415]]

adverse effect on marine mammals, which includes a careful balancing of 
the likely benefit of any particular measure to the marine mammals with 
the likely effect of that measure on personnel safety, practicality of 
implementation, and impact on the effectiveness of the ``military-
readiness activity.'' Included below are the mitigation measures the 
Navy proposed in their LOA application. NMFS worked with the Navy to 
develop these proposed measures, and they are informed by years of 
experience and monitoring.
    The Navy's proposed mitigation measures are modifications to the 
proposed activities that are implemented for the sole purpose of 
reducing a specific potential environmental impact on a particular 
resource. These do not include standard operating procedures, which are 
established for reasons other than environmental benefit. Most of the 
following proposed mitigation measures are currently, or were 
previously, implemented as a result of past environmental compliance 
documents. The Navy's overall approach to assessing potential 
mitigation measures is based on two principles: (1) Mitigation measures 
will be effective at reducing potential impacts on the resource, and 
(2) from a military perspective, the mitigation measures are 
practicable, executable, and safety and readiness will not be impacted.

Lookouts

    The use of lookouts is a critical component of Navy procedural 
measures and implementation of mitigation zones. Navy lookouts are 
highly qualified and experienced observers of the marine environment. 
Their duties require that they report all objects sighted in the water 
to the Officer of the Deck (OOD) (e.g., trash, a periscope, marine 
mammals, sea turtles) and all disturbances (e.g., surface disturbance, 
discoloration) that may be indicative of a threat to the vessel and its 
crew. There are personnel standing watch on station at all times (day 
and night) when a ship or surfaced submarine is moving through the 
water.
    The Navy would have two types of lookouts for the purposes of 
conducting visual observations: (1) Those positioned on surface ships, 
and (2) those positioned in aircraft or on small boats. Lookouts 
positioned on surface ships would be dedicated solely to diligent 
observation of the air and surface of the water. They would have 
multiple observation objectives, including detecting the presence of 
biological resources and recreational or fishing boats, observing 
mitigation zones, and monitoring for vessel and personnel safety 
concerns.
    Due to aircraft and boat manning and space restrictions, lookouts 
positioned in aircraft or on boats would consist of the aircraft crew, 
pilot, or boat crew. Lookouts positioned in aircraft and boats may be 
responsible for tasks in addition to observing the air or surface of 
the water (for example, navigation of a helicopter or rigid hull 
inflatable boat). However, aircraft and boat lookouts would, to the 
maximum extent practicable and consistent with aircraft and boat safety 
and training and testing requirements, comply with the observation 
objectives described above for lookouts positioned on surface ships.
    The Navy proposes to use at least one lookout during the training 
and testing activities provided in Table 7. Additional details on 
lookout procedures and implementation are provided in Chapter 11 of the 
Navy's LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications).

Table 7--Lookout Mitigation Measures for Training and Testing Activities
                       Within the MITT Study Area
------------------------------------------------------------------------
                       Training and testing
Number of lookouts          activities                  Benefit
------------------------------------------------------------------------
4.................  Mine countermeasure and    Lookouts can visually
                     neutralization             detect marine mammals so
                     activities using time-     that potentially harmful
                     delay firing devices       impacts from explosives
                     with up to a 20 lb net     use can be avoided.
                     explosive weight          Lookouts dedicated to
                     detonation. If             observations can more
                     applicable, aircrew and    quickly And effectively
                     divers would report        relay sighting
                     sightings of marine        information so that
                     mammals.                   corrective action can be
                                                taken. Support from
                                                aircrew and divers, if
                                                they have are involved,
                                                would increase the
                                                probability of
                                                sightings, reducing the
                                                potential for impacts.
2.................  Vessels greater than 20    Lookouts can visually
                     m\1\ (65 ft) using low-    detect marine mammals so
                     frequency active sonar     that potentially harmful
                     or hull-mounted mid-       impacts from Navy sonar
                     frequency active sonar     and explosives use can
                     associated with anti-      be avoided. Dedicated
                     submarine warfare and      lookouts can more
                     mine warfare activities    quickly and effectively
                     at sea; vessels greater    relay sighting
                     than 200 ft (61 m)         information so that
                     conducting general mine    corrective action can be
                     countermeasure and         taken. Support from
                     neutralization             aircrew and divers, if
                     activities using up to a   they are involved, would
                     20 lb net explosive        increase the probability
                     weight detonation; mine    of sightings, reducing
                     neutralization             the potential for
                     activities involving       impacts.
                     positive control diver-
                     placed charges using up
                     to a 20 lb net explosive
                     weight detonation..
                    Sinking exercises (one in
                     an aircraft and one on a
                     vessel).

[[Page 15416]]

 
1.................  Vessels using low-         Lookouts can visually
                     frequency or hull-         detect marine mammals so
                     mounted mid-frequency      that potentially harmful
                     active sonar associated    impacts from Navy sonar;
                     with anti-submarine or     explosives; sonobuoys;
                     mine warfare activities    gunnery rounds;
                     at sea; ships less than    missiles; explosive
                     65 ft (20 m) in length;    torpedoes; towed
                     the Littoral Combat Ship   systems; surface vessel
                     and similar ships which    propulsion; and non-
                     are minimally manned;      explosive munitions can
                     ships conducting active    be avoided.
                     sonar activities while
                     moored or at anchor
                     (including pierside);
                     ships or aircraft
                     conducting high-
                     frequency or non-hull
                     mounted mid-frequency
                     active sonar associated
                     with anti-submarine and
                     mine warfare activities
                     at sea; helicopter
                     dipping mid-frequency
                     active sonar; IEER
                     sonobuoys; aircraft
                     conducting explosive
                     sonobuoy exercises using
                     0.6-2.5 lb net explosive
                     weight; anti-swimmer
                     grenades; vessels less
                     than 200 ft (61 m)
                     conducting general mine
                     countermeasure and
                     neutralization
                     activities using up to a
                     20 lb net explosive
                     weight detonation;
                     surface gunnery
                     activities; missile
                     using surface target and
                     up to 500 lb net
                     explosive weight;
                     aircraft conducting
                     bombing activities;
                     explosive torpedo
                     testing; vessels
                     underway; activities
                     using towed in-water
                     devices; and activities
                     using non-explosive
                     practice munitions
                     against a surface target.
------------------------------------------------------------------------
\1\ With the exception of the Littoral Combat Ship and similar ships
  which are minimally manned, moored, or anchored.

    Personnel standing watch on the bridge, Commanding Officers, 
Executive Officers, maritime patrol aircraft aircrews, anti-submarine 
warfare helicopter crews, civilian equivalents, and lookouts would 
complete the NMFS-approved Marine Species Awareness Training (MSAT) 
prior to standing watch or serving as a lookout. Additional details on 
the Navy's MSAT program are provided in Chapter 5 of the MITT DEIS/
OEIS.

Mitigation Zones

    The Navy proposes to use mitigation zones to reduce the potential 
impacts to marine mammals from training and testing activities. 
Mitigation zones are measured as the radius from a source and represent 
a distance that the Navy would monitor. Mitigation zones are applied to 
acoustic stressors (i.e., non-impulsive and impulsive sound) and 
physical strike and disturbance (e.g., vessel movement and bombing 
exercises). In each instance, visual detections of marine mammals would 
be communicated immediately to a watch station for information 
dissemination and appropriate action. Acoustic detections would be 
communicated to lookouts posted in aircraft and on surface vessels.
    Most of the current mitigation zones for activities that involve 
the use of impulsive and non-impulsive sources were originally designed 
to reduce the potential for onset of TTS. The Navy updated their 
acoustic propagation modeling to incorporate new hearing threshold 
metrics (i.e., upper and lower frequency limits), new marine mammal 
density data, and factors such as an animal's likely presence at 
various depths. An explanation of the acoustic propagation modeling 
process can be found in previous authorizations for the Atlantic Fleet 
Training and Testing Study Area and the Hawaii-Southern California 
Training and Testing Study Area and the Determination of Acoustic 
Effects on Marine Mammals and Sea Turtles for the Mariana Islands 
Training and Testing EIS/OEIS technical report (DoN, 2013).
    As a result of updates to the acoustic propagation modeling, some 
of the ranges to effects are larger than previous model outputs. Due to 
the ineffectiveness of mitigating such large areas, the Navy is unable 
to mitigate for onset of TTS during every activity. However, some 
ranges to effects are smaller than previous models estimated, and the 
mitigation zones were adjusted accordingly to provide consistency 
across the measures. The Navy developed each proposed mitigation zone 
to avoid or reduce the potential for onset of the lowest level of 
injury, PTS, out to the predicted maximum range. Mitigating to the 
predicted maximum range to PTS also mitigates to the predicted maximum 
range to onset mortality (1 percent mortality), onset slight lung 
injury, and onset slight gastrointestinal tract injury, since the 
maximum range to effects for these criteria are shorter than for PTS. 
Furthermore, in most cases, the predicted maximum range to PTS also 
covers the predicted average range to TTS. Tables 8 and 9 summarize the 
predicted average range to TTS, average range to PTS, maximum range to 
PTS, and recommended mitigation zone for each activity category, based 
on the Navy's acoustic propagation modeling results. It is important 
for the Navy to have standardized mitigation zones wherever training 
and testing may be conducted. The information in Tables 8 and 9 was 
developed in consideration of both Atlantic and Pacific Ocean 
conditions, marine mammal species, environmental factors, 
effectiveness, and operational assessments.
    The Navy's proposed mitigation zones are based on the longest range 
for all the marine mammal and sea turtle functional hearing groups. 
Most mitigation zones were driven by the high-frequency cetaceans or 
sea turtles functional hearing group. Therefore, the mitigation zones 
are more conservative for the remaining functional hearing groups (low-
frequency and mid-frequency cetaceans), and likely cover a larger 
portion of the potential range to onset of TTS. Additional information 
on the estimated range to effects for each acoustic stressor is 
detailed in Chapter 11 of the Navy's LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications).

[[Page 15417]]



                                         Table 8--Predicted Ranges to TTS, PTS, and Recommended Mitigation Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                       Predicted average
         Activity category            Bin  (representative      Predicted average      (longest) range to     Predicted maximum         Recommended
                                            source) *        (longest) range to TTS           PTS                range to PTS         mitigation zone
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Non-Impulsive Sound
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-Frequency and Hull-Mounted Mid-  MF1 (SQS-53 ASW hull-   4,251 yd. (3,887 m)...  281 yd. (257 m)......  <292 yd. (<267 m)....  6 dB power down at
 Frequency Active Sonar.              mounted sonar).                                                                               1,000 yd. (914 m);
                                                                                                                                   4 dB power down at
                                                                                                                                    500 yd. (457 m); and
                                                                                                                                   shutdown at 200 yd.
                                                                                                                                    (183 m).
                                     LF4 (low-frequency      4,251 yd. (3,887 m)...  281 yd. (257 m)......  <292 yd. (<267 m)....  200 yd. (183 m).**
                                      sonar) **.
High-Frequency and Non-Hull Mounted  MF4 (AQS-22 ASW         226 yd. (207 m).......  <55 yd. (<50 m)......  <55 yd. (<50 m)......  200 yd. (183 m).
 Mid-Frequency Active Sonar.          dipping sonar).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Explosive and Impulsive Sound
--------------------------------------------------------------------------------------------------------------------------------------------------------
Improved Extended Echo Ranging       E4....................  434 yd. (397 m).......  156 yd. (143 m)......  563 yd. (515 m)......  600 yd. (549 m).
 Sonobuoys.                          (Explosive sonobuoy)..
Explosive Sonobuoys using 0.6-2.5    E3....................  290 yd. (265 m).......  113 yd. (103 m)......  309 yd. (283 m)......  350 yd. (320 m).
 lb. NEW.                            (Explosive sonobuoy)..
Anti-Swimmer Grenades..............  E2....................  190 yd. (174 m).......  83 yd. (76 m)........  182 yd. (167 m)......  200 yd. (183 m).
                                     (Up to 0.5 lb. NEW)...
                                    --------------------------------------------------------------------------------------------------------------------
Mine Countermeasure and                                                          NEW dependent (see Table 9)
 Neutralization Activities Using
 Positive Control Firing Devices.
                                    --------------------------------------------------------------------------------------------------------------------
Mine Neutralization Diver-Placed     E6....................  407 yd. (372 m).......  98 yd. (90 m)........  102 yd. (93 m).......  1,000 yd. (915 m).
 Mines Using Time-Delay Firing       (Up to 20 lb. NEW)....
 Devices.
Gunnery Exercises--Small- and        E2....................  190 yd. (174 m).......  83 yd. (76 m)........  182 yd. (167 m)......  200 yd. (183 m).
 Medium-Caliber (Surface Target).    (40 mm projectile)....
Gunnery Exercises--Large-Caliber     E5....................  453 yd. (414 m).......  186 yd. (170 m)......  526 yd. (481 m)......  600 yd. (549 m).
 (Surface Target).                   (5 in. projectiles at
                                      the surface * * * ).
Missile Exercises up to 250 lb. NEW  E9....................  949 yd. (868 m).......  398 yd. (364 m)......  699 yd. (639 m)......  900 yd. (823 m).
 (Surface Target).                   (Maverick missile)....
Missile Exercises up to 500 lb. NEW  E10...................  1,832 yd. (1,675 m)...  731 yd. (668 m)......  1,883 yd. (1,721 m)..  2,000 yd. (1.8 km).
 (Surface Target).                   (Harpoon missile).....
Bombing Exercises..................  E12...................  2,513 yd. (2.3 km)....  991 yd. (906 m)......  2,474 yd. (2.3 km)...  2,500 yd. (2.3 km).**
                                     (MK-84 2,000 lb. bomb)
Torpedo (Explosive) Testing........  E11...................  1,632 yd. (1.5 km)....  697 yd. (637 m)......  2,021 yd. (1.8 km)...  2,100 yd. (1.9 km).
                                     (MK-48 torpedo).......
Sinking Exercises..................  E12...................  2,513 yd. (2.3 km)....  991 yd. (906 m)......  2,474 yd. (2.3 km)...  2.5 nm.
                                     (Various sources up to
                                      the MK-84 2,000 lb.
                                      bomb).
--------------------------------------------------------------------------------------------------------------------------------------------------------
ASW: anti-submarine warfare; NEW: net explosive weight; PTS: permanent threshold shift; TTS: temporary threshold shift
* This table does not provide an inclusive list of source bins; bins presented here represent the source bin with the largest range to effects within
  the given activity category.
** Recommended mitigation zones are larger than the modeled injury zones to account for multiple types of sources or charges being used.
*** The representative source bin E5 has different range to effects depending on the depth of activity occurrence (at the surface or at various depths).


                   Table 9--Predicted Ranges To Effects and Mitigation Zone Radius for Mine Countermeasure and Neutralization Activities Using Positive Control Firing Devices
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                     General Mine Countermeasure and neutralization activities using positive      Mine countermeasure and Neutralization activities using diver placed charges
                                                             control firing devices *                                                        under positive control **
   Charge size  net explosive   ----------------------------------------------------------------------------------------------------------------------------------------------------------------
         weight (bins)            Predicted average    Predicted average   Predicted maximum      Recommended      Predicted average   Predicted average   Predicted maximum      Recommended
                                     range to TTS        range to PTS        range to PTS       Mitigation Zone      range to TTS        range to PTS        range too PTS      mitigation zone
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
2.6-5 lb. (1.2-2.3 kg) (E4)....  434 yd.............  197 yd............  563 yd............  600 yd............  545 yd............  169 yd............  301 yd............  350 yd.
                                 (474 m)............  (180 m)...........  (515 m)...........  (549 m)...........  (498 m)...........  (155 m)...........  (275 m)...........  (320 m).
6-10 lb. (2.7-4.5 kg) (E5).....  525 yd.............  204 yd............  649 Yd............  800 yd............  587 yd............  203 yd............  464 yd............  500 yd.
                                 (480 m)............  (187 m)...........  (593 m)...........  (732 m)...........  (537 m)...........  (185 m)...........  (424 m)...........  457 m).

[[Page 15418]]

 
11-20 lb. (5-9.1 kg) (E6)......  766 yd.............  288 yd............  648 yd............  800 yd............  647 yd............  232 yd............  469 yd............  500 yd.
                                 (700 m)............  263 m)............  (593 m)...........  (732 m)...........  (592 m)...........  (212 m)...........  (429 m)...........  (457 m).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
PTS: permanent threshold shift; TTS: temporary threshold shift.
* These mitigation zones are applicable to all mine countermeasure and neutralization activities conducted in all locations specified in Chapter 2 of the Navy's LOA application.
** These mitigation zones are only applicable to mine countermeasure and neutralization activities involving the use of diver placed charges. These activities are conducted in shallow-water
  and the mitigation zones are based only on the functional hearing groups with species that occur in these areas (mid-frequency cetaceans and sea turtles).

Low-Frequency and Hull Mounted Mid-Frequency Active Sonar

    Mitigation measures do not currently exist for low-frequency active 
sonar sources analyzed in the MITT EIS/OEIS and associated with new 
platforms or systems, such as the Littoral Combat Ship. The Navy is 
proposing to (1) add mitigation measures for low-frequency active 
sonar, (2) continue implementing the current measures for mid-frequency 
active sonar, and (3) clarify the conditions needed to recommence an 
activity after a sighting. The proposed measures are below.
    Training and testing activities that involve the use of low-
frequency and hull-mounted mid-frequency active sonar (including 
pierside) would use lookouts for visual observation from a ship 
immediately before and during the exercise. With the exception of 
certain low-frequency sources that are not able to be powered down 
during the activity (e.g., low-frequency sources within bin LF4), 
mitigation would involve powering down the sonar by 6 dB when a marine 
mammal or sea turtle is sighted within 1,000 yd. (914 m), and by an 
additional 4 dB when sighted within 500 yd. (457 m) from the source, 
for a total reduction of 10 dB. If the source can be turned off during 
the activity, active transmissions would cease if a marine mammal or 
sea turtle is sighted within 200 yd. (183 m).
    Active transmission would recommence if any one of the following 
conditions is met: (1) The animal is observed exiting the mitigation 
zone, (2) the animal is thought to have exited the mitigation zone 
based on its course and speed, (3) the mitigation zone has been clear 
from any additional sightings for a period of 30 minutes, (4) the ship 
has transited more than 2,000 yd. (1.8 km) beyond the location of the 
last sighting, or (5) the ship concludes that dolphins are deliberately 
closing in on the ship to ride the ship's bow wave (and there are no 
other marine mammal sightings within the mitigation zone). Active 
transmission may resume when dolphins are bow riding because they are 
out of the main transmission axis of the active sonar while in the 
shallow-wave area of the vessel bow.
    If the source is not able to be powered down during the activity 
(e.g., low-frequency sources within bin LF4), mitigation would involve 
ceasing active transmission if a marine mammal or sea turtle is sighted 
within 200 yd. (183 m). Active transmission would recommence if any one 
of the following conditions is met: (1) The animal is observed existing 
the mitigation zone, (2) the animal is thought to have exited the 
mitigation zone based on a determination of its course and speed and 
the relative motion between the animal and the source, (3) the 
mitigation zone has been clear from any additional sightings for a 
period of 30 minutes, or (4) the ship has transited more than 400 yd. 
(366 m) beyond the location of the last sighting and the animal's 
estimated course direction.

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

    Mitigation measures do not currently exist for all high-frequency 
and non-hull mounted mid-frequency active sonar activities (i.e., new 
sources or sources not previously analyzed). The Navy is proposing to 
(1) continue implementing the current mitigation measures for 
activities currently being executed, such as dipping sonar activities, 
(2) extend the implementation of its current mitigation to all other 
activities in this category, and (3) clarify the conditions needed to 
recommence an activity after a sighting. The proposed measures are 
provided below.
    Mitigation would include visual observation from a vessel or 
aircraft (with the exception of platforms operating at high altitudes) 
immediately before and during active transmission within a mitigation 
zone of 200 yd. (183 m) from the active sonar source. For activities 
involving helicopter-deployed dipping sonar, visual observation would 
commence 10 minutes before the first deployment of active dipping 
sonar. If the source can be turned off during the activity, active 
transmission would cease if a marine mammal is sighted within the 
mitigation zone. Active transmission would recommence if any one of the 
following conditions is met: (1) The animal is observed exiting the 
mitigation zone, (2) the animal is thought to have exited the 
mitigation zone based on its course and speed, (3) the mitigation zone 
has been clear from any additional sightings for a period of 10 minutes 
for an aircraft-deployed source, (4) the mitigation zone has been clear 
from any additional sightings for a period of 30 minutes for a vessel-
deployed source, (5) the vessel or aircraft has repositioned itself 
more than 400 yd. (366 m) away from the location of the last sighting 
and the animal's estimated course direction, or (6) the vessel 
concludes that dolphins are deliberately closing in to ride the 
vessel's bow wave (and there are no other marine mammal sightings 
within the mitigation zone).

Improved Extended Echo Ranging Sonobuoys

    The Navy is proposing to (1) modify the mitigation measures 
currently implemented for this activity by reducing the marine mammal 
and sea turtle mitigation zone from 1,000 yd (914 m) to 600 yd (549 m), 
and (2) clarify the conditions needed to recommence an activity after a 
sighting for ease of implementation. The recommended measures are 
provided below.
    Mitigation would include pre-exercise aerial observation and 
passive acoustic monitoring, which would begin 30 minutes before the 
first source/receiver pair detonation and continue throughout the 
duration of the exercise within a mitigation zone of 600 yd (549 m) 
around an Improved Extended Echo Ranging sonobuoy. The pre-exercise

[[Page 15419]]

aerial observation would include the time it takes to deploy the 
sonobuoy pattern (deployment is conducted by aircraft dropping 
sonobuoys in the water). Explosive detonations would cease if a marine 
mammal is sighted within the mitigation zone. Detonations would 
recommence if any one of the following conditions is met: (1) The 
animal is observed exiting the mitigation zone, (2) the animal is 
thought to have exited the mitigation zone based on its course and 
speed, or (3) the mitigation zone has been clear from any additional 
sightings for a period of 30 minutes.
    Passive acoustic monitoring would be conducted with Navy assets, 
such as sonobuoys, already participating in the activity. These assets 
would only detect vocalizing marine mammals within the frequency bands 
monitored by Navy personnel. Passive acoustic detections would not 
provide range or bearing to detected animals, and therefore cannot 
provide locations of these animals. Passive acoustic detections would 
be reported to lookouts posted in aircraft and on vessels in order to 
increase vigilance of their visual surveillance.

Explosive Sonobuoys Using 0.6 to 2.5 lb Net Explosive Weight

    Mitigation measures do not currently exist for this activity. The 
Navy is proposing to add the recommended measures provided below.
    Mitigation would include pre-exercise aerial monitoring during 
deployment of the field of sonobuoy pairs (typically up to 20 minutes) 
and continuing throughout the duration of the exercise within a 
mitigation zone of 350 yd (320 m) around an explosive sonobuoy. 
Explosive detonations would cease if a marine mammal or sea turtle is 
sighted within the mitigation zone. Detonations would recommence if any 
one of the following conditions is met: (1) The animal is observed 
exiting the mitigation zone, (2) the animal is thought to have exited 
the mitigation zone based on its course and speed, or (3) the 
mitigation zone has been clear from any additional sightings for a 
period of 10 minutes.
    Passive acoustic monitoring would also be conducted with Navy 
assets, such as sonobuoys, already participating in the activity. These 
assets would only detect vocalizing marine mammals within the frequency 
bands monitored by Navy personnel. Passive acoustic detections would 
not provide range or bearing to detected animals, and therefore cannot 
provide locations of these animals. Passive acoustic detections would 
be reported to lookouts posted in aircraft in order to increase 
vigilance of their visual surveillance.

Anti-Swimmer Grenades

    Mitigation measures do not currently exist for this activity. The 
Navy is proposing to add the recommended measures provided below.
    Mitigation would include visual observation from a small boat 
immediately before and during the exercise within a mitigation zone of 
200 yd (183 m) around an anti-swimmer grenade. Explosive detonations 
would cease if a marine mammal or sea turtle is sighted within the 
mitigation zone. Detonations would recommence if any one of the 
following conditions is met: (1) The animal is observed exiting the 
mitigation zone, (2) the animal is thought to have exited the 
mitigation zone based on its course and speed, (3) the mitigation zone 
has been clear from any additional sightings for a period of 30 
minutes, or (4) the activity has been repositioned more than 400 yd 
(366 m) away from the location of the last sighting.

Mine Countermeasure and Neutralization Activities Using Positive 
Control Firing Devices

    Mitigation measures do not currently exist for general mine 
countermeasures and neutralization activities. The Navy is proposing to 
add the recommended measures provided below.
    General mine countermeasure and neutralization activity mitigation 
would include visual surveillance from small boats or aircraft 
beginning 30 minutes before, during, and 30 minutes after the 
completion of the exercise within the mitigation zones around the 
detonation site. Explosive detonations would cease if a marine mammal 
is sighted within the mitigation zone. Detonations would recommence if 
any one of the following conditions is met: (1) The animal is observed 
exiting the mitigation zone, (2) the animal is thought to have exited 
the mitigation zone based on its course and speed, or (3) the 
mitigation zone has been clear from any additional sightings for a 
period of 30 minutes.
    For activities involving positive control diver-placed charges, the 
Navy is proposing to (1) modify the currently implemented mitigation 
measures for activities involving up to a 20 lb net explosive weight 
detonation, and (2) clarify the conditions needed to recommence an 
activity after a sighting. For comparison, the currently implemented 
mitigation zone for up to 10 lb net explosive weight charges is 700 yd 
(640 m). The recommended measures for activities involving positive 
control diver-placed activities are provided below.
    Visual observation would be conducted by either two small boats, or 
one small boat in combination with one helicopter. Boats would position 
themselves near the mid-point of the mitigation zone radius (but always 
outside the detonation plume radius and human safety zone) and travel 
in a circular pattern around the detonation location. When using two 
boats, each boat would be positioned on opposite sides of the 
detonation location, separated by 180 degrees. If used, helicopters 
would travel in a circular pattern around the detonation location.
    Explosive detonations would cease if a marine mammal is sighted in 
the water portion of the mitigation zone (i.e., not on shore). 
Detonations would recommence if any one of the following conditions is 
met: (1) The animal is observed exiting the mitigation zone, (2) the 
animal is thought to have exited the mitigation zone based on its 
course and speed, or (3) the mitigation zone has been clear from any 
additional sightings for a period of 30 minutes. For training exercises 
that include the use of multiple detonations, the second (or third, 
etc.) detonation will occur either immediately after the preceding 
detonation (i.e., within 10 seconds of the preceding detonation) or 
after 30 minutes have passed.

Mine Neutralization Diver-Placed Mines Using Time-Delay Firing Devices

    As background, when mine neutralization activities using diver-
placed charges (up to a 20 lb net explosive weight) are conducted with 
a time-delay firing device, the detonation is fused with a specified 
time-delay by the personnel conducting the activity and is not 
authorized until the area is clear at the time the fuse is initiated. 
During these activities, the detonation cannot be terminated once the 
fuse is initiated due to human safety concerns.
    Mitigation measures do not currently exist for activities using 
diver-placed charges (up to a 20 lb net explosive weight) with a time-
delay firing device. The Navy is recommending the measures provided 
below.
    The Navy is proposing to (1) modify the mitigation zones and 
observation requirements currently implemented for mine countermeasure 
and neutralization activities using diver-placed time-delay firing 
devices (up to a 10 lb net explosive weight), and (2) clarify the 
conditions needed to recommence an activity after a sighting. For 
comparison, the current mitigation zones are based on size of charge 
and length of time-delay, ranging from a 1,000 yd (914 m)

[[Page 15420]]

mitigation zone for a 5 lb net explosive weight charge using a 5-minute 
time-delay to a 1,400 yd (1,280 m) mitigation zone for a 10 lb net 
explosive weight charge using a 10-minute time-delay. The current 
requirement in other range complexes is for two boats to be used for 
observation in mitigation zones that are less than 1,400 yd (1,280 m). 
The recommended measures for activities involving diver-placed time-
delay firing devices are provided below.
    The Navy recommends one mitigation zone for all net explosive 
weights and lengths of time-delay. Mine neutralization activities 
involving diver-placed charges would not include time-delay longer than 
10 min. Mitigation would include visual surveillance from small boats 
or aircraft commencing 30 minutes before, during, and until 30 minutes 
after the completion of the exercise within a mitigation zone of 1,000 
yd (915 m) around the detonation site. During activities using time-
delay firing devices involving up to a 20 lb net explosive weight 
charge, visual observation will take place using two small boats. The 
fuse initiation would cease if a marine mammal is sighted within the 
water portion of the mitigation zone (i.e., not on shore). Fuse 
initiation would recommence if any one of the following conditions is 
met: (1) The animal is observed exiting the mitigation zone, (2) the 
animal is thought to have exited the mitigation zone based on its 
course and speed, or (3) the mitigation zone has been clear from any 
additional sightings for a period of 30 minutes.
    Survey boats would position themselves near the mid-point of the 
mitigation zone radius (but always outside the detonation plume radius/
human safety zone) and travel in a circular pattern around the 
detonation location. One lookout from each boat would look inward 
toward the detonation site and the other lookout would look outward 
away from the detonation site. When using two small boats, each boat 
would be positioned on opposite sides of the detonation location, 
separated by 180 degrees. If available for use, helicopters would 
travel in a circular pattern around the detonation location.

Gunnery Exercises (Small- and Medium-Caliber Using Surface Target)

    Mitigation measures do not currently exist for small- and medium-
caliber gunnery using a surface target. The Navy is recommending the 
measures provided below.
    Mitigation would include visual observation from a vessel or 
aircraft immediately before and during the exercise within a mitigation 
zone of 200 yd (183 m) around the intended impact location. Vessels 
would observe the mitigation zone from the firing position. When 
aircraft are firing, the aircrew would maintain visual watch of the 
mitigation zone during the activity. Firing would cease if a marine 
mammal is sighted within the mitigation zone. Firing would recommence 
if any one of the following conditions is met: (1) the animal is 
observed exiting the mitigation zone, (2) the animal is thought to have 
exited the mitigation zone based on its course and speed, (3) the 
mitigation zone has been clear from any additional sightings for a 
period of 10 minutes for a firing aircraft, (4) the mitigation zone has 
been clear from any additional sightings for a period of 30 minutes for 
a firing ship, or (5) the intended target location has been 
repositioned more than 400 yd (366 m) away from the location of the 
last sighting.

Gunnery Exercises (Large-Caliber Using a Surface Target)

    The Navy is proposing to (1) continue using the currently 
implemented mitigation zone for this activity, (2) clarify the 
conditions needed to recommence an activity after a sighting, and (3) 
modify the seafloor habitat mitigation area. Mitigation would include 
visual observation from a ship immediately before and during the 
exercise within a mitigation zone of 600 yd (549 m) around the intended 
impact location. Ships would observe the mitigation zone from the 
firing position. Firing would cease if a marine mammal or sea turtle is 
sighted within the mitigation zone. Firing would recommence if any one 
of the following conditions is met: (1) the animal is observed exiting 
the mitigation zone, (2) the animal is thought to have exited the 
mitigation zone based on its course and speed, or (3) the mitigation 
zone has been clear from any additional sightings for a period of 30 
minutes.

Missile Exercises (Including Rockets) Up to 20 lb Net Explosive Weight 
Using a Surface Target

    The Navy is proposing to (1) modify the mitigation measures 
currently implemented for this activity by reducing the mitigation zone 
from 1,800 yd (1.6 km) to 900 yd (823 m), (2) clarify the conditions 
needed to recommence an activity after a sighting, and (3) modify the 
platform of observation to eliminate the requirement to observe when 
ships are firing.
    When aircraft are firing, mitigation would include visual 
observation by the aircrew or supporting aircraft prior to commencement 
of the activity within a mitigation zone of 900 yd (823 m) around the 
deployed target. Firing would recommence if any one of the following 
conditions is met: (1) the animal is observed exiting the mitigation 
zone, (2) the animal is thought to have exited the mitigation zone 
based on its course and speed, or (3) the mitigation zone has been 
clear from any additional sightings for a period of 10 minutes or 30 
minutes (depending on aircraft type).

Missile Exercises From 251 to 500 lb Net Explosive Weight Using a 
Surface Target

    The Navy is proposing to modify the mitigation measures currently 
implemented for this activity by increasing the mitigation zone from 
1,800 yd (1.6 km) to 2,000 yd (1.8 km). When aircraft are firing, 
mitigation would include visual observation by the aircrew prior to 
commencement of the activity within a mitigation zone of 2,000 yd (1.8 
km) around the intended impact location. Firing would cease if a marine 
mammal or sea turtle is sighted within the mitigation zone. Firing 
would recommence if any one of the following conditions is met: (1) the 
animal is observed exiting the mitigation zone, (2) the animal is 
thought to have exited the mitigation zone based on its course and 
speed, or (3) the mitigation zone has been clear from any additional 
sightings for a period of 10 minutes or 30 minutes (depending on 
aircraft type).

Bombing Exercises

    The Navy is proposing to (1) modify the mitigation measures 
currently implemented for this activity by increasing the mitigation 
zone from 1,000 yd. (914 m) to 2,500 yd. (2.3 km), and (2) clarify the 
conditions needed to recommence an activity after a sighting.
    Mitigation would include visual observation from the aircraft 
immediately before the exercise and during target approach within a 
mitigation zone of 2,500 yd (2.3 km) around the intended impact 
location. Bombing would cease if a marine mammal or sea turtle is 
sighted within the mitigation zone. Bombing would recommence if any one 
of the following conditions is met: (1) The animal is observed exiting 
the mitigation zone, (2) the animal is thought to have exited the 
mitigation zone based on its course and speed, or (3) the mitigation 
zone has been clear from any additional sightings for a period of 10 
minutes.

Torpedo (Explosive) Testing

    Mitigation measures do not currently exist for torpedo (explosive) 
testing. The

[[Page 15421]]

Navy is recommending the measures provided below.
    Mitigation would include visual observation by aircraft (with the 
exception of platforms operating at high altitudes) immediately before, 
during, and after the exercise within a mitigation zone of 2,100 yd 
(1.9 km) around the intended impact location. Firing would cease if a 
marine mammal is sighted within the mitigation zone. Firing would 
recommence if any one of the following conditions is met: (1) The 
animal is observed exiting the mitigation zone, (2) the animal is 
thought to have exited the mitigation zone based on its course and 
speed, or (3) the mitigation zone has been clear from any additional 
sightings for a period of 10 minutes or 30 minutes (depending on 
aircraft type).
    In addition to visual observation, passive acoustic monitoring 
would be conducted with Navy assets, such as passive ships sonar 
systems or sonobuoys, already participating in the activity. Passive 
acoustic observation would be accomplished through the use of remote 
acoustic sensors or expendable sonobuoys, or via passive acoustic 
sensors on submarines when they participate in the proposed action. 
These assets would only detect vocalizing marine mammals within the 
frequency bands monitored by Navy personnel. Passive acoustic 
detections would not provide range or bearing to detected animals, and 
therefore cannot provide locations of these animals. Passive acoustic 
detections would be reported to the lookout posted in the aircraft in 
order to increase vigilance of the visual surveillance and to the 
person in control of the activity for their consideration in 
determining when the mitigation zone is free of visible marine mammals.

Sinking Exercises

    The Navy is proposing to (1) modify the mitigation measures 
currently implemented for this activity by increasing the mitigation 
zone from 2.0 nm (3.7 km) to 2.5 nm (4.6 km), (2) clarify the 
conditions needed to recommence an activity after a sighting, and (3) 
adopt the marine mammal and sea turtle mitigation zone size for 
aggregations of jellyfish for ease of implementation. The recommended 
measures are provided below.
    Mitigation would include visual observation within a mitigation 
zone of 2.5 nm (4.6 km) around the target ship hulk. Sinking exercises 
would include aerial observation beginning 90 minutes before the first 
firing, visual observations from vessels throughout the duration of the 
exercise, and both aerial and vessel observation immediately after any 
planned or unplanned breaks in weapons firing of longer than 2 hours. 
Prior to conducting the exercise, the Navy would review remotely sensed 
sea surface temperature and sea surface height maps to aid in deciding 
where to release the target ship hulk.
    The Navy would also monitor using passive acoustics during the 
exercise. Passive acoustic monitoring would be conducted with Navy 
assets, such as passive ships sonar systems or sonobuoys, already 
participating in the activity. These assets would only detect 
vocalizing marine mammals within the frequency bands monitored by Navy 
personnel. Passive acoustic detections would not provide range or 
bearing to detected animals, and therefore cannot provide locations of 
these animals. Passive acoustic detections would be reported to 
lookouts posted in aircraft and on vessels in order to increase 
vigilance of their visual surveillance. Lookouts will also increase 
observation vigilance before the use of torpedoes or unguided ordnance 
with a net explosive weight of 500 lb or greater, or if the Beaufort 
sea state is a 4 or above.
    The exercise would cease if a marine mammal, sea turtle, or 
aggregation of jellyfish (i.e., visible gathering of multiple 
jellyfish) is sighted within the mitigation zone. The exercise would 
recommence if any one of the following conditions is met: (1) The 
animal (or jellyfish aggregation) is observed exiting the mitigation 
zone, (2) the animal (or jellyfish aggregation) is thought to have 
exited the mitigation zone based on its course and speed, or (3) the 
mitigation zone has been clear from any additional sightings for a 
period of 30 minutes. Upon sinking the vessel, the Navy would conduct 
post-exercise visual surveillance of the mitigation zone for 2 hours 
(or until sunset, whichever comes first).

Gunnery Exercises (Large Caliber)

    The Navy is proposing to implement the following mitigation 
measure, which only applies to the firing side of the ship as provided 
below.
    For all explosive and non-explosive large-caliber gunnery exercises 
conducted from a ship, mitigation would include visual observation 
immediately before and during the exercise within a mitigation zone of 
70 yd (64 m) within 30 degrees on either side of the gun target line on 
the firing side. Firing would cease if a marine mammal is sighted 
within the mitigation zone. Firing would recommence if any one of the 
following conditions is met: (1) The animal is observed exiting the 
mitigation zone, (2) the animal is thought to have exited the 
mitigation zone based on its course and speed, (3) the mitigation zone 
has been clear from any additional sightings for a period of 30 
minutes, or (4) the vessel has repositioned itself more than 140 yd 
(128 m) away from the location of the last sighting and the animal's 
estimated course direction.

Vessels and In-Water Devices

    Vessel Movement--Ships would avoid approaching marine mammals head 
on and would maneuver to maintain a mitigation zone of 457 m around 
observed whales, and 183 m around all other marine mammals (except bow 
riding dolphins), providing it is safe to do so.
    Towed In-Water Devices--The Navy would ensure towed in-water 
devices avoid coming within a mitigation zone of 229 m around any 
observed marine mammal, providing it is safe to do so.

Non-Explosive Practice Munitions

    Gunnery Exercises (small, medium, and large caliber using a surface 
target)--Mitigation would include visual observation immediately before 
and during the exercise within a mitigation zone of 183 m around the 
intended impact location. Firing would cease if a marine mammal is 
visually detected within the mitigation zone. Firing would recommence 
if any one of the following conditions are met: (1) The animal is 
observed exiting the mitigation zone, (2) the animal is thought to have 
exited the mitigation zone based on its course and speed, (3) the 
mitigation zone has been clear from any additional sightings for a 
period of 10 minutes for a firing aircraft, (4) the mitigation zone has 
been clear from any additional sightings for a period of 30 minutes for 
a firing ship, or (5) the intended target location has been 
repositioned more than 366 m away from the location of the last 
sighting and the animal's estimated course direction.
    Bombing Exercises--Mitigation would include visual observation from 
the aircraft immediately before the exercise and during target approach 
within a mitigation zone of 914 m around the intended impact location. 
Bombing would cease if a marine mammal is visually detected within the 
mitigation zone. Bombing would recommence if any one of the following 
conditions are met: (1) The animal is observed exiting the mitigation 
zone, (2) the animal is thought to have exited the mitigation zone 
based on its course and speed, or (3) the mitigation zone has been 
clear from any additional sightings for a period of 10 minutes.

[[Page 15422]]

Cetacean and Sound Mapping

    NMFS Office of Protected Resources standardly considers available 
information about marine mammal habitat used to inform discussions with 
applicants regarding potential spatio-temporal limitations of their 
activities that might help effect the least practicable adverse impact. 
Through the Cetacean and Sound Mapping effort (http://cetsound.noaa.gov/index.html), NOAA's Cetacean Density and Distribution 
Mapping Working Group (CetMap) is currently involved in a process to 
compile available literature and solicit expert review to identify 
areas and times where species are known to concentrate for specific 
behaviors (e.g., feeding, breeding/calving, or migration) or be range-
limited (e.g., small resident populations). These areas, called 
Biologically Important Areas (BIAs), are useful tools for planning and 
impact assessments and are being provided to the public via the 
CetSound Web site, along with a summary of the supporting information. 
However, areas outside of the U.S. EEZ were not evaluated as part of 
the BIA exercises.

Stranding Response Plan

    NMFS and the Navy developed a Stranding Response Plan for MIRC in 
2010 as part of the incidental take authorization process. The 
Stranding Response Plan is specifically intended to outline the 
applicable requirements in the event that a marine mammal stranding is 
reported in the MIRC during a major training exercise. NMFS considers 
all plausible causes within the course of a stranding investigation and 
this plan in no way presumes that any strandings in a Navy range 
complex are related to, or caused by, Navy training and testing 
activities, absent a determination made during investigation. The plan 
is designed to address mitigation, monitoring, and compliance. The Navy 
is currently working with NMFS to refine this plan for the new MITT 
Study Area. The current Stranding Response Plan for the MIRC is 
available for review here: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.

Mitigation Conclusions

    NMFS has carefully evaluated the Navy's proposed mitigation 
measures--many of which were developed with NMFS' input during the 
first phase of authorizations--and considered a broad range of other 
measures in the context of ensuring that NMFS prescribes the means of 
effecting the least practicable adverse impact on the affected marine 
mammal species and stocks and their habitat. Our evaluation of 
potential measures included consideration of the following factors in 
relation to one another: The manner in which, and the degree to which, 
the successful implementation of the mitigation measures is expected to 
reduce the likelihood and/or magnitude of adverse impacts to marine 
mammal species and stocks and their habitat; the proven or likely 
efficacy of the measures; and the practicability of the suite of 
measures for applicant implementation, including consideration of 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    Any mitigation measure(s) prescribed by NMFS should be able to 
accomplish, have a reasonable likelihood of accomplishing (based on 
current science), or contribute to accomplishing one or more of the 
general goals listed below:
    a. Avoid or minimize injury or death of marine mammals wherever 
possible (goals b, c, and d may contribute to this goal).
    b. Reduce the numbers of marine mammals (total number or number at 
biologically important time or location) exposed to received levels of 
MFAS/HFAS, underwater detonations, or other activities expected to 
result in the take of marine mammals (this goal may contribute to a, 
above, or to reducing harassment takes only).
    c. Reduce the number of times (total number or number at 
biologically important time or location) individuals would be exposed 
to received levels of MFAS/HFAS, underwater detonations, or other 
activities expected to result in the take of marine mammals (this goal 
may contribute to a, above, or to reducing harassment takes only).
    d. Reduce the intensity of exposures (either total number or number 
at biologically important time or location) to received levels of MFAS/
HFAS, underwater detonations, or other activities expected to result in 
the take of marine mammals (this goal may contribute to a, above, or to 
reducing the severity of harassment takes only).
    e. Avoid or minimize adverse effects to marine mammal habitat, 
paying special attention to the food base, activities that block or 
limit passage to or from biologically important areas, permanent 
destruction of habitat, or temporary destruction/disturbance of habitat 
during a biologically important time.
    f. For monitoring directly related to mitigation--increase the 
probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation (shut-down zone, etc.).
    Based on our evaluation of the Navy's proposed measures, as well as 
other measures considered by NMFS, NMFS has determined preliminarily 
that the Navy's proposed mitigation measures (especially when the 
adaptive management component is taken into consideration (see Adaptive 
Management, below)) are adequate means of effecting the least 
practicable adverse impacts on marine mammals species or stocks and 
their habitat, paying particular attention to rookeries, mating 
grounds, and areas of similar significance, while also considering 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    The proposed rule comment period provides the public an opportunity 
to submit recommendations, views, and/or concerns regarding this action 
and the proposed mitigation measures. While NMFS has determined 
preliminarily that the Navy's proposed mitigation measures would affect 
the least practicable adverse impact on the affected species or stocks 
and their habitat, NMFS will consider all public comments to help 
inform our final decision. Consequently, the proposed mitigation 
measures may be refined, modified, removed, or added to prior to the 
issuance of the final rule based on public comments received, and where 
appropriate, further analysis of any additional mitigation measures.

Proposed Monitoring and Reporting

    Section 101(a)(5)(A) of the MMPA states that in order to issue an 
ITA for an activity, NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such taking.'' The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for LOAs 
must include the suggested means of accomplishing the necessary 
monitoring and reporting that will result in increased knowledge of the 
species and of the level of taking or impacts on populations of marine 
mammals that are expected to be present.
    Monitoring measures prescribed by NMFS should accomplish one or 
more of the following general goals:
     Increase the probability of detecting marine mammals, both 
within the safety zone (thus allowing for more effective implementation 
of the mitigation) and in general to generate more data to contribute 
to the analyses mentioned below.
     Increase our understanding of how many marine mammals are 
likely to be

[[Page 15423]]

exposed to levels of MFAS/HFAS (or explosives or other stimuli) that we 
associate with specific adverse effects, such as behavioral harassment, 
TTS, or PTS.
     Increase our understanding of how marine mammals respond 
to MFAS/HFAS (at specific received levels), explosives, or other 
stimuli expected to result in take and how anticipated adverse effects 
on individuals (in different ways and to varying degrees) may impact 
the population, species, or stock (specifically through effects on 
annual rates of recruitment or survival) through any of the following 
methods:
     Behavioral observations in the presence of MFAS/HFAS 
compared to observations in the absence of sonar (need to be able to 
accurately predict received level and report bathymetric conditions, 
distance from source, and other pertinent information)
     Physiological measurements in the presence of MFAS/HFAS 
compared to observations in the absence of tactical sonar (need to be 
able to accurately predict received level and report bathymetric 
conditions, distance from source, and other pertinent information)
     Pre-planned and thorough investigation of stranding events 
that occur coincident to naval activities
     Distribution and/or abundance comparisons in times or 
areas with concentrated MFAS/HFAS versus times or areas without MFAS/
HFAS
     Increased our knowledge of the affected species.
     Increase our understanding of the effectiveness of certain 
mitigation and monitoring measures.

Integrated Comprehensive Monitoring Program (ICMP)

    The Navy's ICMP is intended to coordinate monitoring efforts across 
all regions and to allocate the most appropriate level and type of 
effort for each range complex based on a set of standardized 
objectives, and in acknowledgement of regional expertise and resource 
availability. The ICMP is designed to be flexible, scalable, and 
adaptable through the adaptive management and strategic planning 
processes to periodically assess progress and reevaluate objectives. 
Although the ICMP does not specify actual monitoring field work or 
projects, it does establish top-level goals that have been developed in 
coordination with NMFS. As the ICMP is implemented, detailed and 
specific studies will be developed which support the Navy's top-level 
monitoring goals. In essence, the ICMP directs that monitoring 
activities relating to the effects of Navy training and testing 
activities on marine species should be designed to accomplish one or 
more top-level goals. Monitoring would address the ICMP top-level goals 
through a collection of specific regional and ocean basin studies based 
on scientific objectives. Quantitative metrics of monitoring effort 
(e.g., 20 days of aerial surveys) would not be a specific requirement. 
The adaptive management process and reporting requirements would serve 
as the basis for evaluating performance and compliance, primarily 
considering the quality of the work and results produced, as well as 
peer review and publications, and public dissemination of information, 
reports, and data. Details of the ICMP are available online (http://www.navymarinespecies monitoring.us/).

Strategic Planning Process for Marine Species Monitoring

    The Navy also developed the Strategic Planning Process for Marine 
Species Monitoring, which establishes the guidelines and processes 
necessary to develop, evaluate, and fund individual projects based on 
objective scientific study questions. The process uses an underlying 
framework designed around top-level goals, a conceptual framework 
incorporating a progression of knowledge, and in consultation with a 
Scientific Advisory Group and other regional experts. The Strategic 
Planning Process for Marine Species Monitoring would be used to set 
intermediate scientific objectives, identify potential species of 
interest at a regional scale, and evaluate and select specific 
monitoring projects to fund or continue supporting for a given fiscal 
year. This process would also address relative investments to different 
range complexes based on goals across all range complexes, and 
monitoring would leverage multiple techniques for data acquisition and 
analysis whenever possible. The Strategic Planning Process for Marine 
Species Monitoring is also available online (http://www.navymarinespecies monitoring.us/).

Past and Current Monitoring in the MITT Study Area

    NMFS has received multiple years' worth of annual exercise and 
monitoring reports addressing active sonar use and explosive 
detonations within the MIRC 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 Study Area. The Navy's annual 
exercise and monitoring reports may be viewed at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications and http://www.navymarinespeciesmonitoring.us. NMFS has reviewed these reports and 
summarized the results, as related to marine mammal monitoring, below.
    1. The Navy has shown significant initiative in developing its 
marine species monitoring program and made considerable progress toward 
reaching goals and objectives of the ICMP. In 2013, the Navy developed 
a monitoring plan for the MIRC that focused on the goals of the ICMP by 
using the Strategic Planning Process to move away from a monitoring 
plan based on previously-used metrics of effort to a more effective one 
based upon evaluating progress made on monitoring questions.
    2. Monitoring in the Mariana Islands presents special challenges. 
Past experience has proven that windward sides of islands and offshore 
areas are difficult to access in small vessels (HDR, 2011; Hill et al., 
2011; Ligon et al., 2011). Winter conditions consistently impair field 
efforts. For these reasons, sighting opportunities of baleen whales are 
infrequent. Alternative means of collecting data that complement 
existing visual methodologies may help facilitate achieving data 
collection goals.
    3. Observation data from watchstanders aboard Navy vessels is 
generally useful to indicate the presence or absence of marine mammals 
within the mitigation zones (and sometimes beyond) and to document the 
implementation of mitigation measures, but does not provide useful 
species-specific information or behavioral data.
    4. Data gathered by experienced marine mammal observers in a Navy-
wide monitoring program across multiple ranges can provide very 
valuable information at a level of detail not possible with 
watchstanders.
    5. Though it is by no means conclusive, it is worth noting that no 
instances of obvious behavioral disturbance have been observed by Navy 
watchstanders or experienced marine mammal observers conducting visual 
monitoring.
    6. Visual surveys generally provide suitable data for addressing 
questions of distribution and abundance of marine mammals, but are much 
less effective at providing information on movement patterns, habitat 
use, and behavior, with a few notable exceptions where sightings are 
most frequent. A pilot study on shore-based visual observations showed 
potential as an alternative visual methodology for some windward shores 
that are less accessible to small boats due to prevailing weather 
conditions.

[[Page 15424]]

    7. Satellite tagging has proven to be a valuable tool for 
addressing questions of marine mammal movement patterns and habitat use 
of various species in Navy monitoring efforts across the Pacific. 
Recently, this technique has proven to be particularly valuable in the 
MIRC (Hill et al., 2013), and provides data on these questions for 
infrequently-encountered species even when a wide body of visual survey 
data does not exist.
    8. Passive acoustics has significant potential for applications 
addressing animal movements and behavioral response to Navy training 
activities, but require a longer time horizon and heavy investment in 
analysis to produce relevant results. The estimated time required is 
particularly long in MIRC compared to other Navy ranges because 
relatively little is known about the features of marine mammal 
vocalizations specific to populations found in the waters of the MIRC. 
This knowledge can only be gained by gradual long-term accumulation of 
a body of acoustic recordings made of animals that have been visually-
verified to species.
    Navy-funded monitoring accomplishments in the MIRC from 2010 to 
2013 are provided in the Navy's monitoring reports, as required by the 
2010 rulemaking and available here: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. Navy marine species monitoring 
conducted in the MIRC since 2010 utilized a combination of visual line-
transect surveys, non-random/non-systematic visual surveys, satellite 
tagging, biopsy, shore-based visual surveys, analysis of archived 
acoustic data, and deployment of autonomous passive acoustic monitoring 
devices. Following is a summary of the work conducted:
     Collected and analyzed thousands of cetacean photos taken 
during all Marianas surveys;
     Analyzed acoustic recordings from both towed arrays and 
moored passive acoustic monitoring devices, including archived datasets 
and Navy-funded deployments;
     Conducted visual surveys or shore based surveys around 
Guam, Tinian, Rota, Aguijan and Saipan, and funded observers on 
offshore line transect surveys that crossed the MIRC;
     Purchased, deployed, and analyzed data from satellite 
tags;
     Collected and analyzed biopsy samples for population 
structure analysis; and
     Funded NMFS to catalog all photos collected since 2007, 
including performing mark-recapture population analysis.
    Navy and Navy/NMFS collaborative surveys have been conducted in the 
Study Area since 2007. Most recently, Hill et al. (2013) reported 17 
cetacean sightings during 11 surveys off Guam and 20 cetacean sightings 
over the course of 20 surveys of the CNMI. Seventy-two percent of 
sightings in waters of the CNMI occurred in the waters surrounding the 
islands of Saipan, Tinian, and Aguijan. However, the encounter rate 
around the island of Rota was greater than elsewhere in the survey 
area, and species sighted at Rota were in approximately the same 
location when they were sighted during surveys conducted in 2011, 
suggesting that the area is consistently used by those species. The 
Navy's recent photo-ID analysis shows that individual short-finned 
pilot whales, spinner dolphins, and bottlenose dolphins are moving 
between islands. Data collection and analysis within this area is 
ongoing. There have been no reported observations of adverse reactions 
by marine mammals and no dead or injured animals reported associated 
with Navy training activities in the MIRC. The U.S. Pacific Fleet 
funding share as part of the overall Navy-wide funding in marine mammal 
research and monitoring in the MIRC was over $1.4 million from 2010 to 
2012.

Proposed Monitoring for the MITT Study Area

    Based on discussions between the Navy and NMFS, future monitoring 
should address the ICMP top-level goals through a collection of 
specific regional and ocean basin studies based on scientific 
objectives. Quantitative metrics of monitoring effort (e.g., 20 days of 
aerial survey) would not be a specific requirement. Monitoring would 
follow the strategic planning process and conclusions from adaptive 
management review by diverging from non-quantitative metrics of 
monitoring effort towards the primary mandate of setting progress goals 
addressing specific scientific monitoring questions. The adaptive 
management process and reporting requirements would serve as the basis 
for evaluating performance and compliance, primarily considering the 
quality of the work and results produced, as well as peer review and 
publications, and public dissemination of information, reports, and 
data. The strategic planning process would be used to set intermediate 
scientific objectives, identify potential species of interest at a 
regional scale, and evaluate and select specific monitoring projects to 
fund or continue supporting for a given fiscal year. The strategic 
planning process would also address relative investments to different 
range complexes based on goals across all range complexes, and 
monitoring would leverage multiple techniques for data acquisition and 
analysis whenever possible.
    The SAG confirmed the Navy/NMFS decision made in 2009 that because 
so little is known about species occurrence in this area, the priority 
for the MIRC should be establishing basic marine mammal occurrence. 
Passive acoustic monitoring, small boat surveys, biopsy sampling, 
satellite tagging, and photo-identification are all appropriate methods 
for evaluating marine mammal occurrence and abundance in the MITT Study 
Area. Fixed acoustic monitoring and development of local expertise 
ranked highest among the SAG's recommended monitoring methods for the 
area. There is an especially high level of return for monitoring around 
the Mariana Islands because so little is currently known about this 
region. Specific monitoring efforts would result from future Navy/NMFS 
monitoring program management.

Ongoing Navy Research

    The Navy is one of the world's leading organizations in assessing 
the effects of human activities on the marine environment, and provides 
a significant amount of funding and support to marine research, outside 
of the monitoring required by their incidental take authorizations. 
They also develop approaches to ensure that these resources are 
minimally impacted by current and future Navy operations. Navy 
scientists work cooperatively with other government researchers and 
scientists, universities, industry, and non-governmental conservation 
organizations in collecting, evaluating, and modeling information on 
marine resources, including working towards a better understanding of 
marine mammals and sound. From 2004 to 2012, the Navy has provided over 
$230 million for marine species research. The Navy sponsors 70 percent 
of all U.S. research concerning the effects of human-generated sound on 
marine mammals and 50 percent of such research conducted worldwide. 
Major topics of Navy-supported marine species research directly 
applicable to proposed activities within the MITT Study Area include 
the following:
     Better understanding of marine species distribution and 
important habitat areas;
     Developing methods to detect and monitor marine species 
before, during, and after training and testing activities;

[[Page 15425]]

     Better understanding the impacts of sound on marine 
mammals, sea turtles, fish, and birds; and
     Developing tools to model and estimate potential impacts 
of sound.
    It is imperative that the Navy's research and development (R&D) 
efforts related to marine mammals are conducted in an open, transparent 
manner with validated study needs and requirements. The goal of the 
Navy's R&D program is to enable collection and publication of 
scientifically valid research as well as development of techniques and 
tools for Navy, academic, and commercial use. The two Navy 
organizations that account for most funding and oversight of the Navy 
marine mammal research program are the Office of Naval Research (ONR) 
Marine Mammals and Biology Program, and the Office of the Chief of 
Naval Operations (CNO) Energy and Environmental Readiness Division 
(N45) Living Marine Resources (LMR) Program. The primary focus of these 
programs has been on understanding the effects of sound on marine 
mammals, including physiological, behavioral and ecological effects.
    The ONR Marine Mammals and Biology Program supports basic and 
applied research and technology development related to understanding 
the effects of sound on marine mammals, including physiological, 
behavioral, ecological, and population-level effects. Current program 
thrusts include:
     Monitoring and detection;
     Integrated ecosystem research including sensor and tag 
development;
     Effects of sound on marine life including hearing, 
behavioral response studies, diving and stress physiology, and 
Population Consequences of Acoustic Disturbance (PCAD); and
     Models and databases for environmental compliance.
    To manage some of the Navy's marine mammal research programmatic 
elements, OPNAV N45 developed in 2011 a new Living Marine Resources 
(LMR) Research and Development Program. The mission of the LMR program 
is to develop, demonstrate, and assess information and technology 
solutions to protect living marine resources by minimizing the 
environmental risks of Navy at-sea training and testing activities 
while preserving core Navy readiness capabilities. This mission is 
accomplished by:
     Improving knowledge of the status and trends of marine 
species of concern and the ecosystems of which they are a part;
     Developing the scientific basis for the criteria and 
thresholds to measure the effects of Navy generated sound;
     Improving understanding of underwater sound and sound 
field characterization unique to assessing the biological consequences 
resulting from underwater sound (as opposed to tactical applications of 
underwater sound or propagation loss modeling for military 
communications or tactical applications); and
     Developing technologies and methods to monitor and, where 
possible, mitigate biologically significant consequences to living 
marine resources resulting from naval activities, emphasizing those 
consequences that are most likely to be biologically significant.
    The program is focused on three primary objectives that influence 
program management priorities and directly affect the program's success 
in accomplishing its mission:
    1. Collect, Validate, and Rank R&D Needs: Expand awareness of R&D 
program opportunities within the Navy marine resource community to 
encourage and facilitate the submittal of well-defined and appropriate 
needs statements.
    2. Address High Priority Needs: Ensure that program investments and 
the resulting projects maintain a direct and consistent link to the 
defined user needs.
    3. Transition Solutions and Validate Benefits: Maximize the number 
of program-derived solutions that are successfully transitioned to the 
Fleet and system commands.
    The LMR program primarily invests in the following areas:
     Developing Data to Support Risk Threshold Criteria;
     Improved Data Collection on Protected Species, Critical 
Habitat within Navy Ranges;
     New Monitoring and Mitigation Technology Demonstrations;
     Database and Model Development; and
     Education and Outreach, Emergent Opportunities.
    LMR currently supports the Marine Mammal Monitoring on Ranges 
program at the Pacific Missile Range Facility on Kauai and, along with 
ONR, the multi-year Southern California Behavioral Response Study 
(http://www.socal-brs.org). This type of research helps in 
understanding the marine environment and the effects that may arise 
from underwater noise in oceans. Further, NMFS is working on a long-
term stranding study that will be supported by the Navy by way of a 
funding and information sharing component (see below).

Navy Research and Development

    Navy Funded--At this time, there are no LMR or ONR funded research 
and development projects in the MITT Study Area. However, when projects 
are initiated, the Navy's monitoring program will be coordinated with 
the research and development monitoring program to leverage research 
objectives, assets, and studies where possible under the ICMP.
    Other National Department of Defense Funded Initiatives--The 
Strategic Environmental Research and Development Program (SERDP) and 
Environmental Security Technology Certification Program (ESTCP) are the 
Department of Defense's environmental research programs, harnessing the 
latest science and technology to improve environmental performance, 
reduce costs, and enhance and sustain mission capabilities. The 
programs respond to environmental technology requirements common to all 
military services, complementing the services' research programs. SERDP 
and ESTCP promote partnerships and collaboration among academia, 
industry, the military services, and other federal agencies. They are 
independent programs managed from a joint office to coordinate the full 
spectrum of efforts, from basic and applied research to field 
demonstration and validation.

Adaptive Management

    The final regulations governing the take of marine mammals 
incidental to Navy training and testing activities in the MITT Study 
Area would contain an adaptive management component carried over from 
previous authorizations. Although better than 5 years ago, our 
understanding of the effects of Navy training and testing activities 
(e.g., mid- and high-frequency active sonar, underwater detonations) on 
marine mammals is still relatively limited, and yet the science in this 
field is evolving fairly quickly. These circumstances make the 
inclusion of an adaptive management component both valuable and 
necessary within the context of 5-year regulations for activities that 
have been associated with marine mammal mortality in certain 
circumstances and locations.
    The reporting requirements associated with this proposed rule are 
designed to provide NMFS with monitoring data from the previous year to 
allow NMFS to consider whether any changes are appropriate. NMFS and 
the Navy would meet to discuss the monitoring reports, Navy R&D 
developments, and current

[[Page 15426]]

science and whether mitigation or monitoring modifications are 
appropriate. The use of adaptive management allows NMFS to consider new 
information from different sources to determine (with input from the 
Navy regarding practicability) on an annual or biennial basis if 
mitigation or monitoring measures should be modified (including 
additions or deletions). Mitigation measures could be modified if new 
data suggests that such modifications would have a reasonable 
likelihood of reducing adverse effects to marine mammals and if the 
measures are practicable.
    The following are some of the possible sources of applicable data 
to be considered through the adaptive management process: (1) Results 
from monitoring and exercises reports, as required by MMPA 
authorizations; (2) compiled results of Navy funded R&D studies; (3) 
results from specific stranding investigations; (4) results from 
general marine mammal and sound research; and (5) any information which 
reveals that marine mammals may have been taken in a manner, extent, or 
number not authorized by these regulations or subsequent LOAs.

Proposed Reporting Measures

    In order to issue an ITA for an activity, section 101(a)(5)(A) of 
the MMPA states that NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such taking.'' Effective reporting is 
critical both to compliance as well as ensuring that the most value is 
obtained from the required monitoring. Some of the reporting 
requirements are still in development and the final rulemaking may 
contain additional details not contained here. Additionally, proposed 
reporting requirements may be modified, removed, or added based on 
information or comments received during the public comment period. 
Reports from individual monitoring events, results of analyses, 
publications, and periodic progress reports for specific monitoring 
projects would be posted to the Navy's Marine Species Monitoring web 
portal: http://www.navymarinespeciesmonitoring.us. Currently, there are 
several different reporting requirements pursuant to these proposed 
regulations:
    General Notification of Injured or Dead Marine Mammals--Navy 
personnel would ensure that NMFS (the appropriate Regional Stranding 
Coordinator) is notified immediately (or as soon as clearance 
procedures allow) if an injured or dead marine mammal is found during 
or shortly after, and in the vicinity of, any Navy training exercise 
utilizing mid-frequency active sonar, high-frequency active sonar, or 
underwater explosive detonations. The Navy would provide NMFS with 
species identification or a description of the animal(s), the condition 
of the animal(s) (including carcass condition if the animal is dead), 
location, time of first discovery, observed behaviors (if alive), and 
photographs or video (if available). The MITT Stranding Response Plan 
contains further reporting requirements for specific circumstances 
(http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications).
    Annual Monitoring and Exercise Reports--As noted above, reports 
from individual monitoring events, results of analyses, publications, 
and periodic progress reports for specific monitoring projects would be 
posted to the Navy's Marine Species Monitoring web portal and NMFS' Web 
site as they become available. Progress and results from all monitoring 
activity conducted within the MITT Study Area, as well as required 
Major Training Event exercise activity, would be summarized in an 
annual report. A draft report would be submitted either 90 days after 
the calendar year or 90 days after the conclusion of the monitoring 
year, date to be determined by the adaptive management review process. 
In the past, each annual report has summarized data for a single year. 
At the Navy's suggestion, future annual reports would take a cumulative 
approach in that each report will compare data from that year to all 
previous years. For example, the third annual report will include data 
from the third year and compare it to data from the first and second 
years. This will provide an ongoing cumulative look at the Navy's 
annual monitoring and exercise and testing reports and eliminate the 
need for a separate comprehensive monitoring and exercise summary 
report at the end of the 5-year period.

Estimated Take by Incidental Harassment

    In the potential effects section, NMFS' analysis identified the 
lethal responses, physical trauma, sensory impairment (PTS, TTS, and 
acoustic masking), physiological responses (particular stress 
responses), and behavioral responses that could potentially result from 
exposure to mid- and high-frequency active sonar or underwater 
explosive detonations. In this section, we will relate the potential 
effects to marine mammals from mid- and high-frequency active sonar and 
underwater detonation of explosives to the MMPA regulatory definitions 
of Level A and Level B harassment and attempt to quantify the effects 
that might occur from the proposed training and testing activities in 
the Study Area.
    As mentioned previously, behavioral responses are context-
dependent, complex, and influenced to varying degrees by a number of 
factors other than just received level. For example, an animal may 
respond differently to a sound emanating from a ship that is moving 
towards the animal than it would to an identical received level coming 
from a vessel that is moving away, or to a ship traveling at a 
different speed or at a different distance from the animal. At greater 
distances, though, the nature of vessel movements could also 
potentially not have any effect on the animal's response to the sound. 
In any case, a full description of the suite of factors that elicited a 
behavioral response would require a mention of the vicinity, speed and 
movement of the vessel, or other factors. So, while sound sources and 
the received levels are the primary focus of the analysis and those 
that are laid out quantitatively in the regulatory text, it is with the 
understanding that other factors related to the training are sometimes 
contributing to the behavioral responses of marine mammals, although 
they cannot be quantified.

Definition of Harassment

    As mentioned previously, with respect to military readiness 
activities, section 3(18)(B) of the MMPA defines ``harassment'' as: (i) 
Any act that injures or has the significant potential to injure a 
marine mammal or marine mammal stock in the wild [Level A Harassment]; 
or (ii) any act that disturbs or is likely to disturb a marine mammal 
or marine mammal stock in the wild by causing disruption of natural 
behavioral patterns, including, but not limited to, migration, 
surfacing, nursing, breeding, feeding, or sheltering, to a point where 
such behavioral patterns are abandoned or significantly altered [Level 
B Harassment].

Level B Harassment

    Of the potential effects that were described earlier in this 
document, the following are the types of effects that fall into the 
Level B harassment category:
    Behavioral Harassment--Behavioral disturbance that rises to the 
level described in the definition above, when resulting from exposures 
to non-impulsive or impulsive sound, is considered Level B harassment. 
Some of the lower level physiological stress responses discussed 
earlier would also likely co-occur with the predicted harassments, 
although these responses

[[Page 15427]]

are more difficult to detect and fewer data exist relating these 
responses to specific received levels of sound. When Level B harassment 
is predicted based on estimated behavioral responses, those takes may 
have a stress-related physiological component as well.
    Earlier in this document, we described the Southall et al., (2007) 
severity scaling system and listed some examples of the three broad 
categories of behaviors: 0-3 (Minor and/or brief behaviors); 4-6 
(Behaviors with higher potential to affect foraging, reproduction, or 
survival); 7-9 (Behaviors considered likely to affect the 
aforementioned vital rates). Generally speaking, MMPA Level B 
harassment, as defined in this document, would include the behaviors 
described in the 7-9 category, and a subset, dependent on context and 
other considerations, of the behaviors described in the 4-6 category. 
Behavioral harassment does not generally include behaviors ranked 0-3 
in Southall et al., (2007).
    Acoustic Masking and Communication Impairment--Acoustic masking is 
considered Level B harassment as it can disrupt natural behavioral 
patterns by interrupting or limiting the marine mammal's receipt or 
transmittal of important information or environmental cues.
    Temporary Threshold Shift (TTS)--As discussed previously, TTS can 
affect how an animal behaves in response to the environment, including 
conspecifics, predators, and prey. The following physiological 
mechanisms are thought to play a role in inducing auditory fatigue: 
effects to sensory hair cells in the inner ear that reduce their 
sensitivity; modification of the chemical environment within the 
sensory cells; residual muscular activity in the middle ear, 
displacement of certain inner ear membranes; increased blood flow; and 
post-stimulatory reduction in both efferent and sensory neural output. 
Ward (1997) suggested that when these effects result in TTS rather than 
PTS, they are within the normal bounds of physiological variability and 
tolerance and do not represent a physical injury. Additionally, 
Southall et al. (2007) indicate that although PTS is a tissue injury, 
TTS is not because the reduced hearing sensitivity following exposure 
to intense sound results primarily from fatigue, not loss, of cochlear 
hair cells and supporting structures and is reversible. Accordingly, 
NMFS classifies TTS (when resulting from exposure to sonar and other 
active acoustic sources and explosives and other impulsive sources) as 
Level B harassment, not Level A harassment (injury).

Level A Harassment

    Of the potential effects that were described earlier, following are 
the types of effects that fall into the Level A Harassment category:
    Permanent Threshold Shift (PTS)--PTS (resulting either from 
exposure to MFAS/HFAS or explosive detonations) is irreversible and 
considered an injury. PTS results from exposure to intense sounds that 
cause a permanent loss of inner or outer cochlear hair cells or exceed 
the elastic limits of certain tissues and membranes in the middle and 
inner ears and result in changes in the chemical composition of the 
inner ear fluids.
    Tissue Damage due to Acoustically Mediated Bubble Growth--A few 
theories suggest ways in which gas bubbles become enlarged through 
exposure to intense sounds (MFAS/HFAS) to the point where tissue damage 
results. In rectified diffusion, exposure to a sound field would cause 
bubbles to increase in size. A short duration of sonar pings (such as 
that which an animal exposed to MFAS would be most likely to encounter) 
would not likely be long enough to drive bubble growth to any 
substantial size. Alternately, bubbles could be destabilized by high-
level sound exposures such that bubble growth then occurs through 
static diffusion of gas out of the tissues. The degree of 
supersaturation and exposure levels observed to cause microbubble 
destabilization are unlikely to occur, either alone or in concert 
because of how close an animal would need to be to the sound source to 
be exposed to high enough levels, especially considering the likely 
avoidance of the sound source and the required mitigation. Still, 
possible tissue damage from either of these processes would be 
considered an injury.
    Tissue Damage due to Behaviorally Mediated Bubble Growth--Several 
authors suggest mechanisms by which marine mammals could behaviorally 
respond to exposure to MFAS/HFAS by altering their dive patterns 
(unusually rapid ascent, unusually long series of surface dives, etc.) 
in a manner that might result in unusual bubble formation or growth 
ultimately resulting in tissue damage. In this scenario, the rate of 
ascent would need to be sufficiently rapid to compromise behavioral or 
physiological protections against nitrogen bubble formation. There is 
considerable disagreement among scientists as to the likelihood of this 
phenomenon (Piantadosi and Thalmann, 2004; Evans and Miller, 2003). 
Although it has been argued that traumas from recent beaked whale 
strandings are consistent with gas emboli and bubble-induced tissue 
separations (Jepson et al., 2003; Fernandez et al., 2005), nitrogen 
bubble formation as the cause of the traumas has not been verified. If 
tissue damage does occur by this phenomenon, it would be considered an 
injury.
    Physical Disruption of Tissues Resulting from Explosive Shock 
Wave--Physical damage of tissues resulting from a shock wave (from an 
explosive detonation) is classified as an injury. Blast effects are 
greatest at the gas-liquid interface (Landsberg, 2000) and gas-
containing organs, particularly the lungs and gastrointestinal tract, 
are especially susceptible (Goertner, 1982; Hill 1978; Yelverton et 
al., 1973). Nasal sacs, larynx, pharynx, trachea, and lungs may be 
damaged by compression/expansion caused by the oscillations of the 
blast gas bubble (Reidenberg and Laitman, 2003). Severe damage (from 
the shock wave) to the ears can include tympanic membrane rupture, 
fracture of the ossicles, damage to the cochlea, hemorrhage, and 
cerebrospinal fluid leakage into the middle ear.
    Vessel or Ordnance Strike--Vessel strike or ordnance strike 
associated with the specified activities would be considered Level A 
harassment, serious injury, or mortality.

Take Thresholds

    For the purposes of an MMPA authorization, three types of take are 
identified: Level B harassment; Level A harassment; and mortality (or 
serious injury leading to mortality). The categories of marine mammal 
responses (physiological and behavioral) that fall into the two 
harassment categories were described in the previous section.
    Because the physiological and behavioral responses of the majority 
of the marine mammals exposed to non-impulse and impulse sounds cannot 
be easily detected or measured, and because NMFS must authorize take 
prior to the impacts to marine mammals, a method is needed to estimate 
the number of individuals that will be taken, pursuant to the MMPA, 
based on the proposed action. To this end, NMFS developed acoustic 
thresholds that estimate at what received level (when exposed to non-
impulse or impulse sounds) Level B harassment and Level A harassment of 
marine mammals would occur. The acoustic thresholds for non-impulse and 
impulse sounds are discussed below.
    Level B Harassment Threshold (TTS)--Behavioral disturbance, 
acoustic masking, and TTS are all considered Level B harassment. Marine 
mammals would usually be behaviorally disturbed

[[Page 15428]]

at lower received levels than those at which they would likely sustain 
TTS, so the levels at which behavioral disturbance are likely to occur 
is considered the onset of Level B harassment. The behavioral responses 
of marine mammals to sound are variable, context specific, and, 
therefore, difficult to quantify (see Risk Function section, below). 
Alternately, TTS is a physiological effect that has been studied and 
quantified in laboratory conditions. Because data exist to support an 
estimate of the received levels at which marine mammals will incur TTS, 
NMFS uses acoustic thresholds to estimate the number of marine mammals 
that might sustain TTS. TTS is a subset of Level B Harassment (along 
with sub-TTS behavioral harassment) and we are not specifically 
required to estimate those numbers; however, the more specifically we 
can estimate the affected marine mammal responses, the better the 
analysis.
    Level A Harassment Threshold (PTS)--For acoustic effects, because 
the tissues of the ear appear to be the most susceptible to the 
physiological effects of sound, and because threshold shifts tend to 
occur at lower exposures than other more serious auditory effects, NMFS 
has determined that PTS is the best indicator for the smallest degree 
of injury that can be measured. Therefore, the acoustic exposure 
associated with onset-PTS is used to define the lower limit of Level A 
harassment.
    PTS data do not currently exist for marine mammals and are unlikely 
to be obtained due to ethical concerns. However, PTS levels for these 
animals may be estimated using TTS data from marine mammals and 
relationships between TTS and PTS that have been determined through 
study of terrestrial mammals.
    We note here that behaviorally mediated injuries (such as those 
that have been hypothesized as the cause of some beaked whale 
strandings) could potentially occur in response to received levels 
lower than those believed to directly result in tissue damage. As 
mentioned previously, data to support a quantitative estimate of these 
potential effects (for which the exact mechanism is not known and in 
which factors other than received level may play a significant role) 
does not exist. However, based on the number of years (more than 60) 
and number of hours of MFAS per year that the U.S. (and other 
countries) has operated compared to the reported (and verified) cases 
of associated marine mammal strandings, NMFS believes that the 
probability of these types of injuries is very low. Tables 10 and 11 
provide a summary of non-impulsive thresholds to TTS and PTS for marine 
mammals. A detailed explanation of how these thresholds were derived is 
provided in the MITT DEIS/OEIS Criteria and Thresholds Technical Report 
(http://mitt-eis.com/DocumentsandReferences/EISDocuments/SupportingTechnicalDocuments.aspx) and summarized in Chapter 6 of the 
Navy's LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications).

                          Table 10--Onset TTS and PTS Thresholds for Non-Impulse Sound
----------------------------------------------------------------------------------------------------------------
                Group                          Species                 Onset TTS                Onset PTS
----------------------------------------------------------------------------------------------------------------
Low-Frequency Cetaceans..............  All mysticetes.........  178 dB re 1[micro]Pa2-   198 dB re 1[micro]Pa2-
                                                                 sec(LFII).               sec(LFII).
Mid-Frequency Cetaceans..............  Most delphinids, beaked  178 dB re 1[micro]Pa2-   198 dB re 1[micro]Pa2-
                                        whales, medium and       sec(MFII).               sec(MFII).
                                        large toothed whales.
High-Frequency Cetaceans.............  Porpoises, Kogia spp...  152 dB re 1[micro]Pa2-   172 dB re 1[micro]Pa2-
                                                                 sec(HFII).               secSEL (HFII).
----------------------------------------------------------------------------------------------------------------
LFII, MFII, HFII: New compound Type II weighting functions.


                                   Table 11--Impulsive Sound Explosive Thresholds for Predicting Injury and Mortality
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                        Slight injury
               Group                        Species        ----------------------------------------------------------------------        Mortality
                                                                     PTS                  GI Tract                 Lung
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-Frequency Cetaceans............  All mysticetes.......  187 dB SEL (LFII) or   237 dB SPL or 104 psi  Equation 1............  Equation 2.
                                                             230 dB Peak SPL.
Mid-Frequency Cetaceans............  Most delphinids,       187 dB SEL (MFII) or
                                      medium and large       230 dB Peak SPL.
                                      toothed whales.
High-Frequency Cetaceans...........  Porpoises and Kogia    161 dB SEL (HFII) or
                                      spp..                  201dB Peak SPL.
--------------------------------------------------------------------------------------------------------------------------------------------------------

Equation 1: = 39.1M1/3 (1+[DRm/
10.081])1/2 Pa-sec

Equation 2: = 91.4M1/3 (1+[DRm/
10.081])1/2 Pa-sec

Where:

M = mass of the animals in kg
DRm = depth of the receiver (animal) in meters

    Level B Harassment Risk Function (Behavioral Harassment)--In 2006, 
NMFS issued the first MMPA authorization to allow the take of marine 
mammals incidental to MFAS (to the Navy for RIMPAC). For that 
authorization, NMFS used 173 dB SEL as the criterion for the onset of 
behavioral harassment (Level B Harassment). This type of single number 
criterion is referred to as a step function, in which (in this example) 
all animals estimated to be exposed to received levels above 173 db SEL 
would be predicted to be taken by Level B Harassment and all animals 
exposed to less than 173 dB SEL would not be taken by Level B 
Harassment. As mentioned previously, marine mammal behavioral responses 
to sound are highly variable and context specific (affected by 
differences in acoustic conditions; differences between species and 
populations; differences in gender, age, reproductive status, or social 
behavior; or the prior experience of the individuals), which does not 
support the use of a step function to estimate behavioral harassment.
    Unlike step functions, acoustic risk continuum functions (which are 
also called ``exposure-response functions'' or ``dose-response 
functions'' in other risk assessment contexts) allow for probability of 
a response that NMFS would classify as harassment to occur

[[Page 15429]]

over a range of possible received levels (instead of one number) and 
assume that the probability of a response depends first on the ``dose'' 
(in this case, the received level of sound) and that the probability of 
a response increases as the ``dose'' increases (see Figure 1a). In 
January 2009, NMFS issued three final rules governing the incidental 
take of marine mammals (within Navy's HRC, SOCAL, and Atlantic Fleet 
Active Sonar Training (AFAST)) that used a risk continuum to estimate 
the percent of marine mammals exposed to various levels of MFAS that 
would respond in a manner NMFS considers harassment.
    The Navy and NMFS have previously used acoustic risk functions to 
estimate the probable responses of marine mammals to acoustic exposures 
for other training and research programs. Examples of previous 
application include the Navy FEISs on the SURTASS LFA sonar (U.S. 
Department of the Navy, 2001c); the North Pacific Acoustic Laboratory 
experiments conducted off the Island of Kauai (Office of Naval 
Research, 2001), and the Supplemental EIS for SURTASS LFA sonar (U.S. 
Department of the Navy, 2007d). As discussed earlier, factors other 
than received level (such as distance from or bearing to the sound 
source, context of animal at time of exposure) can affect the way that 
marine mammals respond; however, data to support a quantitative 
analysis of those (and other factors) do not currently exist. NMFS will 
continue to modify these thresholds as new data become available and 
can be appropriately and effectively incorporated.
    The particular acoustic risk functions developed by NMFS and the 
Navy (see Figures 1a and 1b) estimate the probability of behavioral 
responses to MFAS/HFAS (interpreted as the percentage of the exposed 
population) that NMFS would classify as harassment for the purposes of 
the MMPA given exposure to specific received levels of MFAS/HFAS. The 
mathematical function (below) underlying this curve is a cumulative 
probability distribution adapted from a solution in Feller (1968) and 
was also used in predicting risk for the Navy's SURTASS LFA MMPA 
authorization as well.
[GRAPHIC] [TIFF OMITTED] TP19MR14.004

Where:

R = Risk (0-1.0)
L = Received level (dB re: 1 [micro]Pa)
B = Basement received level = 120 dB re: 1 [micro]Pa
K = Received level increment above B where 50-percent risk = 45 dB 
re: 1 [micro]Pa
A = Risk transition sharpness parameter = 10 (odontocetes) or 8 
(mysticetes)

    Detailed information on the above equation and its parameters is 
available in the MITT DEIS/OEIS and previous Navy documents listed 
above.
    The inclusion of a special behavioral response criterion for beaked 
whales of the family Ziphiidae is new to these criteria. It has been 
speculated that beaked whales might have unusual sensitivities to sonar 
sound due to their likelihood of stranding in conjunction with MFAS 
use, even in areas where other species were more abundant (D'Amico et 
al. 2009), but there were not sufficient data to support a separate 
treatment for beaked whales until recently. With the recent publication 
of results from Blainville's beaked whale monitoring and experimental 
exposure studies on the instrumented Atlantic Undersea Test and 
Evaluation Center range in the Bahamas (McCarthy et al. 2011; Tyack et 
al. 2011), there are now statistically strong data suggesting that 
beaked whales tend to avoid both actual naval MFAS in real anti-
submarine training scenarios as well as sonar-like signals and other 
signals used during controlled sound exposure studies in the same area. 
An unweighted 140 dB re 1 [mu]Pa sound pressure level threshold has 
been proposed by the Navy for significant behavioral effects for all 
beaked whales (family: Ziphiidae).
    If more than one explosive event occurs within any given 24-hour 
period within a training or testing event, behavioral thresholds are 
applied to predict the number of animals that may be taken by Level B 
harassment. For multiple explosive events the behavioral threshold used 
in this analysis is 5 dB less than the TTS onset threshold (in sound 
exposure level). This value is derived from observed onsets of 
behavioral response by test subjects (bottlenose dolphins) during non-
impulse TTS testing (Schlundt et al. 2000). Some multiple explosive 
events, such as certain naval gunnery exercises, may be treated as a 
single impulsive event because a few explosions occur closely spaced 
within a very short period of time (a few seconds). For single impulses 
at received sound levels below hearing loss thresholds, the most likely 
behavioral response is a brief alerting or orienting response. Since no 
further sounds follow the initial brief impulses, Level B take in the 
form of behavioral harassment beyond that associated with potential TTS 
would not be expected to occur. Explosive thresholds are summarized in 
Table 12 and further detailed in the Navy's LOA application.
    Since impulse events can be quite short, it may be possible to 
accumulate multiple received impulses at sound pressure levels 
considerably above the energy-based criterion and still not be 
considered a behavioral take. The Navy treats all individual received 
impulses as if they were one second long for the purposes of 
calculating cumulative sound exposure level for multiple impulse 
events. For example, five air gun impulses, each 0.1 second long, 
received at 178 dB sound pressure level would equal a 175 dB sound 
exposure level, and would not be predicted as leading to a take. 
However, if the five 0.1-second pulses are treated as a 5-second 
exposure, it would yield an adjusted value of approximately 180 dB, 
exceeding the threshold. For impulses associated with explosions that 
have durations of a few microseconds, this assumption greatly 
overestimates effects based on sound exposure level metrics such as TTS 
and PTS and behavioral responses. Appropriate weighting values will be 
applied to the received impulse in one-third octave bands and the 
energy summed to produce a total weighted sound exposure level value. 
For impulsive behavioral criteria, the Navy's proposed weighting 
functions (detailed in the LOA application) are applied to the received 
sound level before being compared to the threshold.

                                                             Table 12--Explosive Thresholds
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                        Slight injury
               Group                        Species        ----------------------------------------------------------------------        Mortality
                                                                     PTS                  GI Tract                 Lung
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-Frequency Cetaceans............  All mysticetes.......  187 dB SEL (LFII) or   237 dB SPL or 104 psi  Equation 1............  Equation 2.
                                                             230 dB Peak SPL.

[[Page 15430]]

 
Mid-Frequency Cetaceans............  Most delphinids,       187 dB SEL (MFII) or
                                      medium and large       230 dB Peak SPL.
                                      toothed whales.
High-Frequency Cetaceans...........  Porpoises and Kogia    161 dB SEL (HFII) or
                                      spp.                   201 dB Peak SPL.
--------------------------------------------------------------------------------------------------------------------------------------------------------

                                                             [GRAPHIC] [TIFF OMITTED] TP19MR14.005
                                                             
Marine Mammal Density Estimates

    A quantitative analysis of impacts on a species requires data on 
the abundance and distribution of the species population in the 
potentially impacted area. One metric for performing this type of 
analysis is density, which is the number of animals present per unit 
area. The Navy compiled existing, publically available density data for 
use in the quantitative acoustic impact analysis. There is no single 
source of density data for every area of the world, species, and season 
because of the costs, resources, and effort required to provide 
adequate survey coverage to sufficiently estimate density. Therefore, 
to estimate marine mammal densities for large areas like the MITT Study 
Area, the Navy compiled data from several sources. The Navy developed a 
hierarchy of density data sources to select the best available data 
based on species, area, and time (season). The resulting Geographic 
Information System database, called the Navy Marine Species Density 
Database, includes seasonal density values for every marine mammal 
species present within the MITT Study Area (DoN, 2013).
    The primary data source for the MITT Study Area is the Navy-funded 
2007 line-transect survey, which provides the only published density 
estimates based upon systematic sighting data collected specifically in 
this region (Fulling et al., 2011). However, the source for density 
estimates for each species in provided in Table 3-2 of the Navy's LOA 
application.

Quantitative Modeling for Impulsive and Non-Impulsive Sound

    The Navy performed a quantitative analysis to estimate the number 
of marine mammals that could be harassed by acoustic sources or 
explosives used during Navy training and testing activities. Inputs to 
the quantitative analysis included marine mammal density estimates; 
marine mammal depth occurrence distributions; oceanographic and 
environmental data; marine mammal hearing data; and criteria and 
thresholds for levels of potential effects. The quantitative analysis 
consists of computer-modeled estimates and a post-model analysis to 
determine the number of potential mortalities and harassments. The 
model calculates sound energy propagation from sonars, other active 
acoustic sources, and explosives during naval activities; the sound or 
impulse received by animat dosimeters representing marine mammals 
distributed in the area around the modeled activity; and whether the 
sound or impulse received by a marine mammal exceeds the thresholds for 
effects. The model estimates are then further analyzed to consider 
animal avoidance and implementation of mitigation measures, resulting 
in final estimates of effects due to Navy training and testing. This 
process results in a reduction to take numbers and is detailed in 
Chapter 6 (section 6.3) of the Navy's application.
    A number of computer models and mathematical equations can be used 
to predict how energy spreads from a sound source (e.g. sonar or 
underwater detonation) to a receiver (e.g. dolphin or sea turtle). 
Basic underwater sound models calculate the overlap of energy and 
marine life using assumptions that account for the many, variable, and 
often unknown factors that can greatly influence the result. 
Assumptions in previous Navy models have intentionally erred on the 
side of overestimation when there are unknowns or when the addition of 
other variables was not likely to substantively change the final 
analysis. For example, because the ocean environment is extremely 
dynamic and information is often limited to a synthesis of data 
gathered over wide areas and requiring many years of research, known 
information tends to be an average of a seasonal or annual variation. 
The Equatorial Pacific El Nino disruption of the ocean-atmosphere 
system is an example of dynamic change where unusually warm ocean 
temperatures are likely to redistribute marine life and alter the 
propagation of underwater sound energy. Previous Navy modeling 
therefore made some assumptions indicative of a maximum theoretical 
propagation for sound energy (such as a perfectly reflective ocean 
surface and a flat seafloor). More complex computer models build upon 
basic modeling by factoring in additional variables in an effort to be 
more accurate by accounting for such things as bathymetry and an 
animal's likely presence at various depths.
    The Navy has developed a set of data and new software tools for 
quantification of estimated marine mammal impacts from Navy activities. 
This new approach is the resulting evolution of the basic model 
previously used by the Navy and reflects a more complex modeling 
approach as described below. Although this more complex computer 
modeling approach accounts for various environmental factors affecting 
acoustic propagation, the current software tools do not consider the 
likelihood that a marine mammal would attempt to avoid repeated 
exposures to a sound or avoid an area of intense activity where a 
training or testing event may be focused. Additionally, the software 
tools do not consider the implementation of mitigation (e.g., stopping 
sonar transmissions when a marine mammal is within a certain distance 
of a ship or range clearance prior to detonations). In both of these 
situations, naval activities are modeled as though an activity would 
occur regardless of proximity to marine mammals and without any 
horizontal movement by the animal away from the sound source or human 
activities (e.g., without accounting for likely animal avoidance). 
Therefore, the final step of the quantitative analysis of acoustic 
effects is to consider the implementation of mitigation and the 
possibility that marine mammals would avoid continued or repeated sound 
exposures.

[[Page 15431]]

    The steps of the quantitative analysis of acoustic effects, the 
values that went into the Navy's model, and the resulting ranges to 
effects are detailed in Chapter 6 of the Navy's LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications).

Take Request

    The MITT DEIS/OEIS considered all training and testing activities 
proposed to occur in the Study Area that have the potential to result 
in the MMPA defined take of marine mammals. The stressors associated 
with these activities included the following:
     Acoustic (sonar and other active acoustic sources, 
explosives, weapons firing, launch and impact noise, vessel noise, 
aircraft noise);
     Energy (electromagnetic devices);
     Physical disturbance or strikes (vessels, in-water 
devices, military expended materials, seafloor devices);
     Entanglement (fiber optic cables, guidance wires, 
parachutes);
     Ingestion (munitions, military expended materials other 
than munitions);
     Indirect stressors (impacts to habitat [sediment and water 
quality, air quality] or prey availability).
    The Navy determined, and NMFS agrees, that three stressors could 
potentially result in the incidental taking of marine mammals from 
training and testing activities within the Study Area: (1) Non-impulse 
acoustic stressors (sonar and other active acoustic sources), (2) 
impulse acoustic stressors (explosives), and (3) vessel strikes. Non-
impulsive stressors have the potential to result in incidental takes of 
marine mammals by Level A or Level B harassment. Impulsive acoustic 
stressors have the potential to result in incidental takes of marine 
mammals by harassment, injury, or mortality. Vessel strikes have the 
potential to result in incidental take from direct injury and/or 
mortality.
    Training and Testing Activities--Based on the Navy's model and 
post-model analysis (described in detail in Chapter 6 of their LOA 
application), Table 13 summarizes the Navy's take request for training 
and testing activities for an annual maximum year (a notional 12-month 
period when all annual and non-annual events could occur) and the 
summation over a 5-year period (annual events occurring five times and 
non-annual events occurring three times). Table 14 summarizes the 
Navy's take request for training and testing activities by species from 
the modeling estimates.
    While the Navy does not anticipate any beaked whale strandings or 
mortalities from sonar and other active sources, in order to account 
for unforeseen circumstances that could lead to such effects the Navy 
requests the annual take, by mortality, of two beaked whales a year as 
part of training and testing activities.
    Vessel strike to marine mammals is not associated with any specific 
training or testing activity but rather a limited, sporadic, and 
accidental result of Navy vessel movement within the Study Area. In 
order to account for the accidental nature of vessel strikes to large 
whales in general, and the potential risk from any vessel movement 
within the Study Area, the Navy is seeking take authorization in the 
event a Navy vessel strike does occur while conducting training or 
testing activities. However, since species identification has not been 
possible in most vessel strike cases, the Navy cannot quantifiably 
predict what species may be taken. Therefore, the Navy seeks take 
authorization by vessel strike for any combined number of large whale 
species to include fin whale, blue whale, humpback whale, Bryde's 
whale, Omura's whale, sei whale, minke whale, or sperm whale. The Navy 
requests takes of large marine mammals over the course of the 5-year 
regulations from training and testing activities as discussed below:
     The take by vessel strike during training or testing 
activities in any given year of no more than one large whale of any 
species including fin whale, blue whale, humpback whale, Bryde's whale, 
Omura's whale, sei whale, minke whale, or sperm whale. The take by 
vessel strike of no more than five large whales from training and 
testing activities over the course of the five years of the MITT 
regulations.
    There are no records of any Navy vessel strikes to marine mammals 
in the MITT Study Area. In areas outside the MITT Study Area (e.g., 
Hawaii and Southern California), there have been Navy strikes of larges 
whales. However, these areas differ significantly from the MITT Study 
Area given that both Hawaii and Southern California have a much higher 
number of Navy vessel activities and much higher densities of large 
whales. However, in order to account for the accidental nature of ship 
strikes in general, and potential risk from any vessel movement within 
the MITT Study Area, the Navy is seeking take authorization in the 
event a Navy ship strike does occur within the MITT Study Area during 
the 5-year authorization period.

  Table 13--Summary of Annual and 5-Year Take Request for Training and
                           Testing Activities
------------------------------------------------------------------------
                                         Training and testing activities
                                       ---------------------------------
    MMPA Category           Source           Annual           5-Year
                                         authorization    authorization
                                           sought \1\       sought \2\
------------------------------------------------------------------------
Mortality............  Vessel strike..  No more than 1   No more than 5
                                         large whale      large whale
                                         mortality in     mortalities
                                         any given year   over five
                                         \4\.             years.\4\
Mortality............  Unspecified \3\  2 mortalities    10 mortalities
                                         to beaked        to beaked
                                         whales \3\.      whales over
                                                          five years.\3\
Level A..............  Impulse and Non- 56--Species      280--Species
                        Impulse.         specific data    specific data
                                         shown in Table   shown in Table
                                         15.              15.
Level B..............  Impulse and Non- 81,906--Species  409,530--Specie
                        Impulse.         specific data    s specific
                                         shown in Table   data shown in
                                         15.              Table 15.
------------------------------------------------------------------------
\1\ These numbers constitute the total for an annual maximum year (a
  notional 12-month period when all annual and non-annual events could
  occur).
\2\ These numbers constitute the summation over a 5-year period with
  annual events occurring five times and non-annual events occurring
  three times.
\3\ The Navy's NAEMO model did not quantitatively predict these
  mortalities. Navy, however, is seeking this particular authorization
  given sensitivities these species may have to anthropogenic
  activities. Request includes 2 Ziphidae beaked whale annually to
  include any combination of Cuvier's beaked whale, Longman's beaked
  whale, and unspecified Mesoplodon sp. (not to exceed 10 beaked whales
  total over the 5-year length of requested authorization).
\4\ The Navy cannot quantifiably predict that proposed takes from
  training or testing will be of any particular species, and therefore
  seeks take authorization for any combination of large whale species
  (fin whale, blue whale, humpback whale, Bryde's whale, Omura's whale,
  sei whale, minke whale, or sperm whale).


[[Page 15432]]


  Table 14--Species-Specific Take Request From Modeling Estimates of Impulsive and Non-Impulsive Source Effects
                                     for All Training and Testing Activities
----------------------------------------------------------------------------------------------------------------
                                                 Annually \1\                    Total over 5-year rule \2\
              Species              -----------------------------------------------------------------------------
                                      Level B      Level A     Mortality     Level B      Level A     Mortality
----------------------------------------------------------------------------------------------------------------
Blue whale........................           28            0            0          140            0            0
Fin whale.........................           28            0            0          140            0            0
Humpback whale....................          860            0            0        4,300            0            0
Sei whale.........................          319            0            0        1,595            0            0
Sperm whale.......................          506            0            0        2,530            0            0
Bryde's whale.....................          398            0            0        1,990            0            0
Minke whale.......................          101            0            0          505            0            0
Omura's whale.....................          103            0            0          515            0            0
Pygmy sperm whale.................        5,579           15            0       27,895           75            0
Dwarf sperm whale.................       14,217           41            0       71,085          205            0
Killer whale......................           84            0            0          420            0            0
False killer whale................          555            0            0        2,775            0            0
Pygmy killer whale................          105            0            0          525            0            0
Short-finned pilot whale..........        1,815            0            0        9,075            0            0
Melon-headed whale................        2,085            0            0       10,425            0            0
Bottlenose dolphin................          741            0            0        3,705            0            0
Pantropical spotted dolphin.......       12,811            0            0       64,055            0            0
Striped dolphin...................        3,298            0            0       16,490            0            0
Spinner dolphin...................          589            0            0        2,945            0            0
Rough toothed dolphin.............        1,819            0            0        9,095            0            0
Fraser's dolphin..................        2,572            0            0       12,860            0            0
Risso's dolphin...................          505            0            0        2,525            0            0
Cuvier's beaked whale.............       22,541            0            0      112,705            0            0
Blainville's beaked whale.........        4,426            0            0       22,130            0            0
Longman's beaked whale............        1,924            0            0        9,620            0            0
Ginkgo-toothed beaked whale.......        3,897            0            0       19,485            0            0
----------------------------------------------------------------------------------------------------------------
\1\ These numbers constitute the total for an annual maximum year (a notional 12-month period when all annual
  and non-annual events could occur).
\2\ These numbers constitute the summation over a 5-year period with annual events occurring five times and non-
  annual events occurring three times.

Analysis and Preliminary Determination

    Negligible impact is ``an impact resulting from the specified 
activity that cannot be reasonably expected to, and is not reasonably 
likely to, adversely affect the species or stock through effects on 
annual rates of recruitment or survival'' (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of Level B harassment takes, 
alone, is not enough information on which to base an impact 
determination. In addition to considering estimates of the number of 
marine mammals that might be ``taken'' through behavioral harassment, 
NMFS must consider other factors, such as the likely nature of any 
responses (their intensity, duration, etc.), the context of any 
responses (critical reproductive time or location, migration, etc.), as 
well as the number and nature of estimated Level A harassment takes, 
the number of estimated mortalities, and effects on habitat.
    The Navy's specified activities have been described based on best 
estimates of the maximum amount of sonar and other acoustic source use 
or detonations that the Navy would conduct. There may be some 
flexibility in that the exact number of hours, items, or detonations 
may vary from year to year, but take totals are not authorized to 
exceed the 5-year totals indicated in Table 13. Furthermore the Navy's 
take request is based on their model and post-model analysis. Generally 
speaking, and especially with other factors being equal, the Navy and 
NMFS anticipate more severe effects from takes resulting from exposure 
to higher received levels (though this is in no way a strictly linear 
relationship throughout species, individuals, or circumstances) and 
less severe effects from takes resulting from exposure to lower 
received levels. The requested number of Level B takes does not equate 
to the number of individual animals the Navy expects to harass (which 
is lower), but rather to the instances of take (i.e., exposures above 
the Level B harassment threshold) that would occur. Depending on the 
location, duration, and frequency of activities, along with the 
distribution and movement of marine mammals, individual animals may be 
exposed to impulse or non-impulse sounds at or above the Level B 
harassment threshold on multiple days. However, the Navy is currently 
unable to estimate the number of individuals that may be taken during 
training and testing activities. The model results estimate the total 
number of takes that may occur to a smaller number of individuals. 
While the model shows that an increased number of exposures may take 
place due to an increase in events/activities and ordnance (compared to 
the 2010 rulemaking for the MIRC), the types and severity of individual 
responses to training and testing activities are not expected to 
change.

Behavioral Harassment

    As discussed previously in this document, marine mammals can 
respond to MFAS/HFAS in many different ways, a subset of which 
qualifies as harassment (see Behavioral Harassment Section). One thing 
that the Level B Harassment take estimates do not take into account is 
the fact that most marine mammals will likely avoid strong sound 
sources to one extent or another. Although an animal that avoids the 
sound source will likely still be taken in some instances (such as if 
the avoidance results in a missed opportunity to feed, interruption of 
reproductive behaviors, etc.) in other

[[Page 15433]]

cases avoidance may result in fewer instances of take than were 
estimated or in the takes resulting from exposure to a lower received 
level than was estimated, which could result in a less severe response. 
For MFAS/HFAS, the Navy provided information (Table 15) estimating the 
percentage of behavioral harassment that would occur within the 6-dB 
bins (without considering mitigation or avoidance). As mentioned above, 
an animal's exposure to a higher received level is more likely to 
result in a behavioral response that is more likely to adversely affect 
the health of the animal. As illustrated below, the majority (about 72 
percent, at least for hull-mounted sonar, which is responsible for most 
of the sonar takes) of calculated takes from MFAS result from exposures 
less than 156 dB. Less than 1 percent of the takes are expected to 
result from exposures above 174 dB.

                                                      Table 15--Non-Impulsive Ranges in 6-dB Bins and Percentage of Behavioral Harassments
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Sonar Bin MF1 (e.g., SQS-53;    Sonar Bin MF4 (e.g., AQS-22;    Sonar Bin MF5 (e.g., SSQ-62;    Sonar Bin HF4 (e.g., SQQ-32;
                                                                      ASW hull mounted sonar)           ASW dipping sonar)                 ASW sonobuoy)                    MIW Sonar)
                                                                 -------------------------------------------------------------------------------------------------------------------------------
                                                                                     Percentage                      Percentage                      Percentage                      Percentage
                         Received level                              Distance at         of          Distance at         of          Distance at         of          Distance at         of
                                                                    which levels     behavioral     which levels     behavioral     which levels     behavioral     which levels     behavioral
                                                                    occur within     harassments    occur within     harassments    occur within     harassments    occur within     harassments
                                                                  radius of source  occurring at  radius of source  occurring at  radius of source  occurring at  radius of source  occurring at
                                                                         (m)        given levels         (m)        given levels         (m)        given levels         (m)        given levels
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     Low Frequency Cetaceans
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
120 <= SPL < 126................................................   183,000-133,000            <1     71,000-65,000            <1     18,000-13,000            <1       2,300-1,700            <1
126 <= SPL < 132................................................   133,000 126,000            <1     65,000-60,000            <1      13,000-7,600            <1       1,700-1,200            <1
132 <= SPL < 138................................................    126,000-73,000            <3      60,000-8,200            42       7,600-2,800            12         1,200-750            <1
138 <= SPL < 144................................................     73,000-67,000            <1       8,200-3,500            10         2,800-900            26           750-500             5
144 <= SPL < 150................................................     67,000-61,000             3       3,500-1,800            12           900-500            15           500-300            17
150 <= SPL < 156................................................     61,000-17,000            68         1,800-950            15           500-250            21           300-150            34
156 <= SPL < 162................................................     17,000-10,300            12           950-450            13           250-100            20           150-100            20
162 <= SPL < 168................................................      10,200 5,600             9           450-200             6           100-<50             6           100-<50            24
168 <= SPL < 174................................................       5,600-1,600             6           200-100             2               <50            <1               <50            <1
174 <= SPL < 180................................................         1,600-800            <1           100-<50            <1               <50            <1               <50            <1
180 <= SPL < 186................................................           800-400            <1               <50            <1               <50            <1               <50            <1
186 <= SPL < 192................................................           400-200            <1               <50            <1               <50            <1               <50            <1
192 <= SPL < 198................................................           200-100            <1               <50            <1               <50            <1               <50            <1
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     Mid-Frequency Cetaceans
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
120 <= SPL < 126................................................   184,000-133,000            <1     72,000-66,000            <1     19,000-15,000            <1       3,600-2,800            <1
126 <= SPL < 132................................................   133,000-126,000            <1     66,000-60,000            <1      15,000-8,500            <1       2,800-2,100            <1
132 <= SPL < 138................................................    126,000-73,000            <1      60,000-8,300            41       8,500-3,300             3       2,100-1,500            <1
138 <= SPL < 144................................................     73,000-67,000            <1       8,300-3,600            10       3,300-1,000            12       1,500-1,000             3
144 <= SPL < 150................................................     67,000-61,000             3       3,600-1,900            12         1,000-500            10          1,00-700            10
150 <= SPL < 156................................................     61,000-18,000            68         1,900-950            15           500-300            22           700-450            21
156 <= SPL < 162................................................     18,000-10,300            13           950-480            12           300-150            27           450-250            32
162 <= SPL < 168................................................      10,300-5,700             9           480-200             7           150-<50            25           250-150            19
168 <= SPL < 174................................................       5,700-1,700             6           200-100             2               <50            <1           150-100             9
174 <= SPL < 180................................................         1,700-900            <1           100-<50            <1               <50            <1           100-<50             6
180 <= SPL < 186................................................           900-400            <1               <50            <1               <50            <1               <50            <1
186 <= SPL < 192................................................           400-200            <1               <50            <1               <50            <1               <50            <1
192 <= SPL < 198................................................           200-100            <1               <50            <1               <50            <1               <50            <1
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
ASW: anti-submarine warfare; MIW: mine warfare; m: meter; SPL: sound pressure level.

    Although the Navy has been monitoring to discern the effects of 
MFAS/HFAS on marine mammals since 2006, and research on the effects of 
MFAS is advancing, our understanding of exactly how marine mammals in 
the Study Area will respond to MFAS/HFAS is still limited. The Navy has 
submitted reports from more than 60 major exercises across Navy range 
complexes that indicate no behavioral disturbance was observed. One 
cannot conclude from these results that marine mammals were not 
harassed from MFAS/HFAS, as a portion of animals within the area of 
concern were not seen (especially those more cryptic, deep-diving 
species, such as beaked whales or Kogia spp.), the full series of 
behaviors that would more accurately show an important change is not 
typically seen (i.e., only the surface behaviors are observed), and 
some of the non-biologist watchstanders might not be well-qualified to 
characterize behaviors. However, one can say that the animals that were 
observed did not respond in any of the obviously more severe ways, such 
as panic, aggression, or anti-predator response.

Diel Cycle

    As noted previously, many animals perform vital functions, such as 
feeding, resting, traveling, and socializing on a diel cycle (24-hour 
cycle). Behavioral reactions to noise exposure (when taking place in a 
biologically important context, such as disruption of critical life 
functions, displacement, or avoidance of important habitat) are more 
likely to be significant if they last more than one diel cycle or recur 
on subsequent days (Southall et al., 2007). Consequently, a behavioral 
response lasting less than one day and not recurring on subsequent days 
is not considered severe unless it could directly affect reproduction 
or survival (Southall et al., 2007).
    In the previous section, we discussed that potential behavioral 
responses to MFAS/HFAS that fall into the category of harassment could 
range in severity. By definition, for military readiness activities, 
takes by behavioral harassment involve the disturbance or likely 
disturbance of a marine mammal or marine mammal stock in the wild by 
causing disruption of natural behavioral patterns (such as migration, 
surfacing, nursing, breeding, feeding, or sheltering) to a point where 
such behavioral patterns are abandoned or significantly altered. These 
reactions would, however, be more of a concern if they were expected to 
last over 24 hrs or be repeated in subsequent days. However, vessels 
with hull-mounted active sonar

[[Page 15434]]

are typically moving at speeds of 10-15 knots, which would make it 
unlikely that the same animal could remain in the immediate vicinity of 
the ship for the entire duration of the exercise. Animals may be 
exposed to MFAS/HFAS for more than one day or on successive days. 
However, because neither the vessels nor the animals are stationary, 
significant long-term effects are not expected.
    Most planned explosive exercises are of a short duration (1-6 
hours). Although explosive exercises may sometimes be conducted in the 
same general areas repeatedly, because of their short duration and the 
fact that they are in the open ocean and animals can easily move away, 
it is similarly unlikely that animals would be exposed for long, 
continuous amounts of time.
TTS
    As mentioned previously, TTS can last from a few minutes to days, 
be of varying degree, and occur across various frequency bandwidths, 
all of which determine the severity of the impacts on the affected 
individual, which can range from minor to more severe. The TTS 
sustained by an animal is primarily classified by three 
characteristics:
    1. Frequency--Available data (of mid-frequency hearing specialists 
exposed to mid- or high-frequency sounds; Southall et al., 2007) 
suggest that most TTS occurs in the frequency range of the source up to 
one octave higher than the source (with the maximum TTS at \1/2\ octave 
above). The more powerful mid-frequency sources used have center 
frequencies between 3.5 and 8 kHz and the other unidentified mid-
frequency sources are, by definition, less than 10 kHz, which suggests 
that TTS induced by any of these mid-frequency sources would be in a 
frequency band somewhere between approximately 2 and 20 kHz. There are 
fewer hours of high-frequency source use and the sounds would attenuate 
more quickly, plus they have lower source levels, but if an animal were 
to incur TTS from these sources, it would cover a higher frequency 
range (sources are between 20 and 100 kHz, which means that TTS could 
range up to 200 kHz; however, high-frequency systems are typically used 
less frequently and for shorter time periods than surface ship and 
aircraft mid-frequency systems, so TTS from these sources is even less 
likely). TTS from explosives would be broadband. Vocalization data for 
each species was provided in the Navy's LOA application.
    2. Degree of the shift (i.e., how many dB is the sensitivity of the 
hearing reduced by)--Generally, both the degree of TTS and the duration 
of TTS will be greater if the marine mammal is exposed to a higher 
level of energy (which would occur when the peak dB level is higher or 
the duration is longer). The threshold for the onset of TTS was 
discussed previously in this document. An animal would have to approach 
closer to the source or remain in the vicinity of the sound source 
appreciably longer to increase the received SEL, which would be 
difficult considering the lookouts and the nominal speed of an active 
sonar vessel (10-15 knots). In the TTS studies, some using exposures of 
almost an hour in duration or up to 217 SEL, most of the TTS induced 
was 15 dB or less, though Finneran et al. (2007) induced 43 dB of TTS 
with a 64-second exposure to a 20 kHz source. However, MFAS emits a 
nominal ping every 50 seconds, and incurring those levels of TTS is 
highly unlikely.
    3. Duration of TTS (recovery time)--In the TTS laboratory studies, 
some using exposures of almost an hour in duration or up to 217 SEL, 
almost all individuals recovered within 1 day (or less, often in 
minutes), though in one study (Finneran et al., 2007), recovery took 4 
days.
    Based on the range of degree and duration of TTS reportedly induced 
by exposures to non-pulse sounds of energy higher than that to which 
free-swimming marine mammals in the field are likely to be exposed 
during MFAS/HFAS training exercises in the Study Area, it is unlikely 
that marine mammals would ever sustain a TTS from MFAS that alters 
their sensitivity by more than 20 dB for more than a few days (and any 
incident of TTS would likely be far less severe due to the short 
duration of the majority of the exercises and the speed of a typical 
vessel). Also, for the same reasons discussed in the Diel Cycle 
section, and because of the short distance within which animals would 
need to approach the sound source, it is unlikely that animals would be 
exposed to the levels necessary to induce TTS in subsequent time 
periods such that their recovery is impeded. Additionally, though the 
frequency range of TTS that marine mammals might sustain would overlap 
with some of the frequency ranges of their vocalization types, the 
frequency range of TTS from MFAS (the source from which TTS would most 
likely be sustained because the higher source level and slower 
attenuation make it more likely that an animal would be exposed to a 
higher received level) would not usually span the entire frequency 
range of one vocalization type, much less span all types of 
vocalizations. If impaired, marine mammals would typically be aware of 
their impairment and implement behaviors to compensate (see Acoustic 
Masking or Communication Impairment section), though these 
compensations may incur energetic costs.

Acoustic Masking or Communication Impairment

    Masking only occurs during the time of the signal (and potential 
secondary arrivals of indirect rays), versus TTS, which continues 
beyond the duration of the signal. Standard MFAS nominally pings every 
50 seconds for hull-mounted sources. For the sources for which we know 
the pulse length, most are significantly shorter than hull-mounted 
active sonar, on the order of several microseconds to tens of 
microseconds. For hull-mounted active sonar, though some of the 
vocalizations that marine mammals make are less than one second long, 
there is only a one in 50 chance that they would occur exactly when the 
ping was received, and when vocalizations are longer than one second, 
only parts of them are masked. Alternately, when the pulses are only 
several microseconds long, the majority of most animals' vocalizations 
would not be masked. Masking effects from MFAS/HFAS are expected to be 
minimal. If masking or communication impairment were to occur briefly, 
it would be in the frequency range of MFAS, which overlaps with some 
marine mammal vocalizations; however, it would likely not mask the 
entirety of any particular vocalization or communication series because 
the signal length, frequency, and duty cycle of the MFAS/HFAS signal 
does not perfectly mimic the characteristics of any marine mammal's 
vocalizations.

PTS, Injury, or Mortality

    NMFS believes that many marine mammals would deliberately avoid 
exposing themselves to the received levels of active sonar necessary to 
induce injury by moving away from or at least modifying their path to 
avoid a close approach. Additionally, in the unlikely event that an 
animal approaches the sonar vessel at a close distance, NMFS believes 
that the mitigation measures (i.e., shutdown/powerdown zones for MFAS/
HFAS) would typically ensure that animals would not be exposed to 
injurious levels of sound. As discussed previously, the Navy utilizes 
both aerial (when available) and passive acoustic monitoring (during 
all ASW exercises) in addition to watchstanders on vessels to detect 
marine mammals for mitigation implementation.

[[Page 15435]]

    If a marine mammal is able to approach a surface vessel within the 
distance necessary to incur PTS, the likely speed of the vessel 
(nominal 10-15 knots) would make it very difficult for the animal to 
remain in range long enough to accumulate enough energy to result in 
more than a mild case of PTS. As mentioned previously and in relation 
to TTS, the likely consequences to the health of an individual that 
incurs PTS can range from mild to more serious dependent upon the 
degree of PTS and the frequency band it is in, and many animals are 
able to compensate for the shift, although it may include energetic 
costs.
    As discussed previously, marine mammals (especially beaked whales) 
could potentially respond to MFAS at a received level lower than the 
injury threshold in a manner that indirectly results in the animals 
stranding. The exact mechanism of this potential response, behavioral 
or physiological, is not known. When naval exercises have been 
associated with strandings in the past, it has typically been when 
three or more vessels are operating simultaneously, in the presence of 
a strong surface duct, and in areas of constricted channels, semi-
enclosed areas, and/or steep bathymetry. Based on the number of 
occurrences where strandings have been definitively associated with 
military active sonar versus the number of hours of active sonar 
training that have been conducted, we believe that the probability is 
small that this will occur. Lastly, an active sonar shutdown protocol 
for strandings involving live animals milling in the water minimizes 
the chances that these types of events turn into mortalities.
    Although there have been no recorded Navy vessel strikes of marine 
mammals in the MITT Study Area to date, NMFS is proposing to authorize 
takes by mortality of a limited number of large whales from vessel 
strike.

Species-Specific Analysis

    In the discussions below, the ``acoustic analysis'' refers to the 
Navy's model results and post-model analysis. The Navy performed a 
quantitative analysis to estimate the number of marine mammals that 
could be harassed by acoustic sources or explosives used during Navy 
training and testing activities. Inputs to the quantitative analysis 
included marine mammal density estimates; marine mammal depth 
occurrence distributions; oceanographic and environmental data; marine 
mammal hearing data; and criteria and thresholds for levels of 
potential effects. Marine mammal densities used in the model may 
overestimate actual densities when species data is limited and for 
species with seasonal migrations. The quantitative analysis consists of 
computer modeled estimates and a post-model analysis to determine the 
number of potential mortalities and harassments. The model calculates 
sound energy propagation from sonars, other active acoustic sources, 
and explosives during naval activities; the sound or impulse received 
by animat dosimeters representing marine mammals distributed in the 
area around the modeled activity; and whether the sound or impulse 
received by a marine mammal exceeds the thresholds for effects. The 
model estimates are then further analyzed to consider animal avoidance 
and implementation of mitigation measures, resulting in final estimates 
of effects due to Navy training and testing. It is important to note 
that the Navy's take estimates represent the total number of takes and 
not the number of individuals taken, as a single individual may be 
taken multiple times over the course of a year.
    Although this more complex computer modeling approach accounts for 
various environmental factors affecting acoustic propagation, the 
current software tools do not consider the likelihood that a marine 
mammal would attempt to avoid repeated exposures to a sound or avoid an 
area of intense activity where a training or testing event may be 
focused. Additionally, the software tools do not consider the 
implementation of mitigation (e.g., stopping sonar transmissions when a 
marine mammal is within a certain distance of a ship or range clearance 
prior to detonations). In both of these situations, naval activities 
are modeled as though an activity would occur regardless of proximity 
to marine mammals and without any horizontal movement by the animal 
away from the sound source or human activities (e.g., without 
accounting for likely animal avoidance). The initial model results 
overestimate the number of takes (as described previously), primarily 
by behavioral disturbance. The final step of the quantitative analysis 
of acoustic effects is to consider the implementation of mitigation on 
Level A harassment and mortality estimates and the possibility that 
marine mammals would avoid continued or repeated sound exposures. NMFS 
provided input to the Navy on this process and the Navy's qualitative 
analysis is described in detail in section 6.3 of their LOA application 
(http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications).
    Mysticetes--The Navy's acoustic analysis indicates that numerous 
exposures of mysticete species to sound levels likely to result in 
Level B harassment may occur, mostly from sonar and other active 
acoustic stressors associated with mostly training and some testing 
activities in the Study Area. Of these species, humpback, blue, fin, 
and sei whales are listed as endangered under the ESA. Level B takes 
are anticipated to be in the form of behavioral harassment and no 
injurious takes of humpback, blue, fin, or sei whales from sonar, or 
other active acoustic stressors are expected. The majority of acoustic 
effects to mysticetes from sonar and other active sound sources during 
training activitites would be primarily from anti-submarine warfare 
events involving surface ships and hull mounted (mid-frequency) sonar. 
Most Level B harassments to mysticetes from sonar would result from 
received levels less than 152 dB SPL. High-frequency systems are not 
within mysticetes' ideal hearing range and it is unlikely that they 
would cause a significant behavioral reaction. The implementation of 
mitigation and the sightability of mysticetes (due to their large size) 
further reduce the potential for a significant behavioral reaction or a 
threshold shift to occur. Furthermore, there are no known areas of 
significance for breeding, calving, or feeding within the MITT Study 
Area.
    In addition to Level B takes, the Navy is requesting no more than 
five large whale mortalities over 5 years (no more than one large whale 
mortality in a given year) due to vessel strike during training and 
testing activities. Of the five takes over 5 years, no more than two 
takes of any one species of blue whale, fin whale, humpback whale, sei 
whale, or sperm whale is proposed. The Navy provided a detailed 
analysis of strike data in section 6.3.4 of their LOA application. To 
date, there have been no recorded Navy vessel strikes in the MITT Study 
Area. However, over a period of 20+ years (1991 to 2013), there have 
been 16 Navy vessel strikes in the SOCAL Range Complex and five Navy 
vessel strikes in HRC. The number of mortalities from vessel strike is 
not expected to be an increase over the past decade, but rather NMFS is 
proposing to authorize these takes for the first time.
    Sperm Whales--The Navy's acoustic analysis indicates that 506 
exposures of sperm whales to sound levels likely to result in Level B 
harassment may occur in the MITT Study Area each year from sonar or 
other active acoustic stressors during training and testing activities.

[[Page 15436]]

These Level B takes are anticipated to be in the form of behavioral 
harassment and no injurious takes of sperm whales from sonar, other 
active acoustic stressors, or explosives are requested or proposed for 
authorization. Sperm whales have shown resilience to acoustic and human 
disturbance, although they may react to sound sources and activities 
within a few kilometers. Sperm whales that are exposed to activities 
that involve the use of sonar and other active acoustic sources may 
alert, ignore the stimulus, avoid the area by swimming away or diving, 
or display aggressive behavior. Some (but not all) sperm whale 
vocalizations might overlap with the MFAS/HFAS TTS frequency range, 
which could temporarily decrease an animal's sensitivity to the calls 
of conspecifics or returning echolocation signals. However, as noted 
previously, NMFS does not anticipate TTS of a long duration or severe 
degree to occur as a result of exposure to MFAS/HFAS. The majority of 
Level B takes are expected to be in the form of mild responses.
    In addition to Level B takes, the Navy is requesting no more than 
five large whale mortalities over 5 years (no more than one large whale 
mortality in a given year) due to vessel strike during training and 
testing activities, which includes sperm whales. However, of the five 
takes over 5 years, no more than two takes of sperm whale is proposed. 
No areas of specific importance for reproduction or feeding for sperm 
whales have been identified in the MITT Study Area.
    Pygmy and Dwarf Sperm Whales--The Navy's acoustic analysis 
indicates that 19,796 exposures of pygmy and dwarf sperm whales to 
sound levels likely to result in Level B harassment may occur from 
sonar and other active acoustic stressors and explosives associated 
with training and testing activities in the Study Area. The Navy's 
acoustic analysis also indicates that 41 exposures of dwarf sperm whale 
and 15 exposures of pygmy sperm whale to sound levels likely to result 
in Level A harassment may occur from active acoustic stressors and 
explosions. Behavioral responses can range from a mild orienting 
response, or a shifting of attention, to flight and panic. These 
species tend to avoid human activity and presumably anthropogenic 
sounds. Pygmy and dwarm sperm whales may startle and leave the 
immediate area of activity, reducing the potential impacts. Significant 
behavioral reactions seem more likely than with most other odontocetes; 
however, it is unlikely that animals would receive multiple exposures 
over a short period of time, allowing animals to recover lost resources 
(e.g., food) or opportunities (e.g., mating). Therefore, long-term 
consequences for individual Kogia or their respective populations are 
not expected. Furthermore, many explosions actually occur upon impact 
with above-water targets. However, sources such as these were modeled 
as exploding at 1 meter depth, which overestimates the potential 
effects.
    Dolphins and Small Whales--The Navy's acoustic analysis indicates 
that 12 species of delphinid (dolphins and small whales) may be exposed 
to sound levels likely to result in Level B harassment: killer whale, 
false killer whale, pygmy killer whale, short-finned pilot whale, 
melon-headed whale, bottlenose dolphin, pantropical spotted dolphin, 
striped dolphin, spinner dolphin, rough toothed dolphin, Fraser's 
dolphin, and Risso's dolphin. All of these takes are anticipated to be 
in the form of behavioral harassment and no injurious takes of 
delphinids from active acoustic stressors or explosives are requested 
or proposed for authorization. Behavioral responses can range from a 
mild orienting response, or a shifting of attention, to flight and 
panic.
    Beaked Whales--The Navy's acoustic analysis indicates that four 
species of beaked whale may be exposed to sound levels likely to result 
in Level B harassment. These takes are anticipated to be in the form of 
behavioral harassment and no injurious takes of dolphins from active 
acoustic stressors or explosives are requested or proposed for 
authorization. Behavioral responses can range from a mild orienting 
response, or a shifting of attention, to flight and panic. In addition, 
the Navy is requesting take by mortality of an average of two beaked 
whales per year. The Navy's model did not quantitatively predict these 
mortalities; however, beaked whales may be more sensitive to 
anthropogenic activities. After decades of the Navy conducting similar 
activities in the MITT Study Area without observed incident, NMFS does 
not expect injury or mortality of beaked whales to occur as a result of 
Navy activities. No areas of specific importance for reproduction or 
feeding for beaked whales have been identified in the MITT Study Area.
    Some beaked whale vocalizations might overlap with the MFAS/HFAS 
frequency range, which could potentially decrease an animal's 
sensitivity to the calls of conspecifics or returning echolocation 
signals for a limited amount of time. However, NMFS does not anticipate 
TTS of a long duration or severe degree to occur as a result of 
exposure to sonar and other active acoustic sources. The Navy does not 
predict any beaked whales to be exposed to sound levels associated with 
PTS or injury.
    As discussed previously, scientific uncertainty exists regarding 
the potential contributing causes of beaked whale strandings and the 
exact behavioral or physiological mechanisms that can potentially lead 
to the ultimate physical effects (stranding and/or death) that have 
been documented in a few cases. Although NMFS does not expect injury or 
mortality of any beaked whale species to occur as a result of the 
Navy's activities involving active acoustic sources, there remains the 
potential for the these sources to contribute to the mortality of 
beaked whales. Consequently, NMFS proposes to authorize mortality and 
we consider the 10 potential mortalities (over a 5-year period) in our 
negligible impact determination (NMFS only intends to authorize a total 
of 10 beaked whale mortalities, but since they could be of any single 
species, we consider the effects of 10 mortalities of any of the four 
species).

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 mitigation and 
monitoring measures, NMFS preliminarily finds that the total marine 
mammal take form the Navy's training and testing activities in the MITT 
Study Area will have a negligible impact on the affected marine mammal 
species or stocks.

Impact on Availability of Affected Species for Taking for Subsistence 
Uses

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

Endangered Species Act (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 Study Area: blue whale, humpback whale, fin 
whale, sei whale, and sperm whale. The Navy will consult with NMFS 
pursuant to section 7 of the ESA, and NMFS will also consult internally 
on the issuance of the MMPA incidental take regulations

[[Page 15437]]

and for MITT activities. Consultation will be concluded prior to a 
determination on the issuance of the final rule and LOA.

National Environmental Policy Act (NEPA)

    NMFS has participated as a cooperating agency on the MITT DEIS/
OEIS, which was published on September 13, 2013 (78 FR 56682). The MITT 
DEIS/OEIS is available online at: http://www.mitt-eis.com. NMFS intends 
to adopt the Navy's final MITT EIS/OEIS (FEIS/OEIS), if adequate and 
appropriate. Currently, we believe that the adoption of the Navy's MITT 
FEIS/OEIS will allow NMFS to meet its responsibilities under NEPA for 
the issuance of regulations and LOAs for MITT. If the Navy's MITT FEIS/
OEIS is deemed inadequate, NMFS would supplement the existing analysis 
to ensure that we comply with NEPA prior to the issuance of the final 
rule or LOA.

Classification

    The Office of Management and Budget has determined that this 
proposed rule is not significant for purposes of Executive Order 12866.
    Pursuant to the Regulatory Flexibility Act (RFA), the Chief Counsel 
for Regulation of the Department of Commerce has certified to the Chief 
Counsel for Advocacy of the Small Business Administration that this 
proposed rule, if adopted, would not have a significant economic impact 
on a substantial number of small entities. The RFA requires federal 
agencies to prepare an analysis of a rule's impact on small entities 
whenever the agency is required to publish a notice of proposed 
rulemaking. However, a federal agency may certify, pursuant to 5 U.S.C. 
605(b), that the action will not have a significant economic impact on 
a substantial number of small entities. The Navy is the sole entity 
that would be affected by this rulemaking, and the Navy is not a small 
governmental jurisdiction, small organization, or small business, as 
defined by the RFA. Any requirements imposed by an LOA issued pursuant 
to these regulations, and any monitoring or reporting requirements 
imposed by these regulations, would be applicable only to the Navy. 
NMFS does not expect the issuance of these regulations or the 
associated LOAs to result in any impacts to small entities pursuant to 
the RFA. Because this action, if adopted, would directly affect the 
Navy and not a small entity, NMFS concludes the action would not result 
in a significant economic impact on a substantial number of small 
entities.

List of Subjects in 50 CFR Part 218

    Exports, Fish, Imports, Incidental take, Indians, Labeling, Marine 
mammals, Navy, Penalties, Reporting and recordkeeping requirements, 
Seafood, Sonar, Transportation.

    Dated: March 5, 2014.
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.

0
2. Subpart J is added to part 218 to read as follows:
Subpart J--Taking and Importing Marine Mammals; U.S. Navy's Mariana 
Islands Training and Testing (MITT)
Sec.
218.90 Specified activity and specified geographical region.
218.91 Effective dates and definitions.
218.92 Permissible methods of taking.
218.93 Prohibitions.
218.94 Mitigation.
218.95 Requirements for monitoring and reporting.
218.96 Applications for Letters of Authorization
218.97 Letters of Authorization.
218.98 Renewal and Modifications of Letters of Authorization and 
Adaptive Management.

Subpart J--Taking and Importing Marine Mammals; U.S. Navy's Mariana 
Islands Training and Testing (MITT)


Sec.  218.90  Specified activity and specified geographical region.

    (a) Regulations in this subpart apply only to the U.S. Navy for the 
taking of marine mammals that occurs in the area outlined in paragraph 
(b) of this section and that occurs incidental to the activities 
described in paragraph (c) of this section.
    (b) The taking of marine mammals by the Navy is only authorized if 
it occurs within the MITT Study Area, which includes the MIRC and areas 
to the north and west. The Study Area includes established ranges, 
operating areas, warning areas, and special use airspace in the region 
of the Mariana Islands that are part of the MIRC, its surrounding seas, 
and a transit corridor to the Hawaii Range Complex. The Study Area also 
includes Navy pierside locations where sonar maintenance and testing 
may occur.
    (c) The taking of marine mammals by the Navy is only authorized if 
it occurs incidental to the following activities within the designated 
amounts of use:
    (1) Non-impulsive Sources Used During Training and Testing:
    (i) Low-frequency (LF) Source Classes:
    (A) LF4--an average of 123 hours per year.
    (B) LF5--an average of 11 hours per year.
    (C) LF6--an average of 40 hours per year.
    (ii) Mid-frequency (MF) Source Classes:
    (A) MF1--an average of 1,872 hours per year.
    (B) MF2--an average of 625 hours per year.
    (C) MF3--an average of 192 hours per year.
    (D) MF4--an average of 214 hours per year.
    (E) MF5--an average of 2,588 items per year.
    (F) MF6--an average of 33 items per year.
    (G) MF8--an average of 123 hours per year.
    (H) MF9--an average of 47 hours per year.
    (I) MF10--an average of 231 hours per year.
    (J) MF11--an average of 324 hours per year.
    (K) MF12--an average of 656 hours per year.
    (iii) High-frequency (HF) and Very High-frequency (VHF) Source 
Classes:
    (A) HF1--an average of 113 hours per year.
    (B) HF4--an average of 1,060 hours per year.
    (C) HF5--an average of 336 hours per year.
    (D) HF6--an average of 1,173 hours per year.
    (iv) Anti-Submarine Warfare (ASW) Source Classes:
    (A) ASW1--an average of 144 hours per year.
    (B) ASW2--an average of 660 items per year.
    (C) ASW3--an average of 3,935 hours per year.
    (D) ASW4--an average of 32 items per year.
    (v) Torpedoes (TORP) Source Classes:
    (A) TORP1--an average of 115 items per year.
    (B) TORP2--an average of 62 items per year.
    (vi) Acoustic Modems (M):
    (A) M3--an average of 112 hours per year.
    (B) [Reserved]
    (vii) Swimmer Detection Sonar (SD):

[[Page 15438]]

    (A) SD1--an average 2,341 hours per year.
    (1) Impulsive Source Detonations During Training and Testing:
    (i) Explosive Classes:
    (A) E1 (0.1 to 0.25 lb NEW)--an average of 10,140 detonations per 
year.
    (B) E2 (0.26 to 0.5 lb NEW)--an average of 106 detonations per 
year.
    (C) E3 (>0.5 to 2.5 lb NEW)--an average of 932 detonations per 
year.
    (D) E4 (>2.5 to 5 lb NEW)--an average of 420 detonations per year.
    (E) E5 (>5 to 10 lb NEW)--an average of 684 detonations per year.
    (F) E6 (>10 to 20 lb NEW)--an average of 76 detonations per year.
    (G) E8 (>60 to 100 lb NEW)--an average of 16 detonations per year.
    (H) E9 (>100 to 250 lb NEW)--an average of 4 detonations per year.
    (I) E10 (>250 to 500 lb NEW)--an average of 12 detonations per 
year.
    (J) E11 (>500 to 650 lb NEW)--an average of 6 detonations per year.
    (K) E12 (>650 to 2,000 lb NEW)--an average of 184 detonations per 
year.
    (ii) [Reserved]


Sec.  218.91  Effective dates and definitions.

    (a) Regulations are effective March 18, 2014 through March 18, 
2019.
    (b) The following definitions are utilized in these regulations:
    (1) Uncommon Stranding Event (USE)--A stranding event that takes 
place within an OPAREA where a Major Training Event (MTE) occurs and 
involves any one of the following:
    (i) Two or more individuals of any cetacean species (not including 
mother/calf pairs), unless of species of concern listed in paragraph 
(b)(1)(ii) of this section found dead or live on shore within a 2-day 
period and occurring within 30 miles of one another.
    (ii) A single individual or mother/calf pair of any of the 
following marine mammals of concern: beaked whale of any species, Kogia 
spp., Risso's dolphin, melon-headed whale, pilot whale, humpback whale, 
sperm whale, blue whale, fin whale, sei whale, or monk seal.
    (iii) A group of two or more cetaceans of any species exhibiting 
indicators of distress.
    (2) Shutdown--The cessation of active sonar operation or detonation 
of explosives within 14 nautical miles of any live, in the water, 
animal involved in a USE.


Sec.  218.92  Permissible methods of taking.

    (a) Under a Letter of Authorization (LOA) issued pursuant to Sec.  
218.97, the Holder of the Letter of Authorization may incidentally, but 
not intentionally, take marine mammals within the area described in 
Sec.  218.90, provided the activity is in compliance with all terms, 
conditions, and requirements of these regulations and the appropriate 
LOA.
    (b) The activities identified in Sec.  218.90(c) must be conducted 
in a manner that minimizes, to the greatest extent practicable, any 
adverse impacts on marine mammals and their habitat.
    (c) The incidental take of marine mammals under the activities 
identified in Sec.  218.90(c) is limited to the following species, by 
the identified method of take:
    (1) Level A and B Harassment for all Training and Testing 
Activities:
    (i) Mysticetes:

    (A) Blue whale (Balaenoptera musculus)
    (B) Bryde's whale (Balaenoptera edeni)
    (C) Fin whale (Balaenoptera physalus)
    (D) Humpback whale (Megaptera novaeangliae)
    (E) Minke whale (Balaenoptera acutorostrata)
    (F) Sei whale (Balaenoptera borealis)
    (G) Omura's whale (Balaenoptera omurai)
    (ii) Odontocetes:
    (A) Blainville's beaked whale (Mesoplodon densirostris)
    (B) Bottlenose dolphin (Tursiops truncatus)
    (C) Cuvier's beaked whale (Ziphius cavirostris)
    (D) Dwarf sperm whale (Kogia sima)
    (E) False killer whale (Pseudorca crassidens)
    (F) Fraser's dolphin (Lagenodelphis hosei)
    (G) Gingko-toothed beaked whale (Mesoplodon ginkgodens)
    (H) Killer whale (Orcinus orca)
    (I) Longman's beaked whale (Indopacetus pacificus)
    (J) Melon-headed whale (Peponocephala electra)
    (K) Pantropical spotted dolphin (Stenella attenuata)
    (L) Pygmy killer whale (Feresa attenuata)
    (M) Pygmy sperm whale (Kogia breviceps)
    (N) Risso's dolphin (Grampus griseus)
    (O) Rough-toothed dolphin (Steno bredanensis)
    (P) Short-finned pilot whale (Globicephala macrorhynchus)
    (Q) Sperm whale (Physeter macrocephalus)
    (R) Spinner dolphin (Stenella longirostris)
    (S) Striped dolphin (Stenella coerulealba)
    (2) Mortality for all Training and Testing Activities:
    (i) No more than 10 beaked whale mortalities.
    (ii) No more than 5 large whale mortalities (no more than 1 in any 
given year) from vessel strike.


Sec.  218.93  Prohibitions.

    Notwithstanding takings contemplated in Sec.  218.92 and authorized 
by an LOA issued under Sec. Sec.  216.106 and 218.97 of this chapter, 
no person in connection with the activities described in Sec.  218.90 
may:
    (a) Take any marine mammal not specified in Sec.  218.92(c);
    (b) Take any marine mammal specified in Sec.  218. 92(c) other than 
by incidental take as specified in Sec.  218.92(c);
    (c) Take a marine mammal specified in Sec.  218.92(c) if such 
taking results in more than a negligible impact on the species or 
stocks of such marine mammal; or
    (d) Violate, or fail to comply with, the terms, conditions, and 
requirements of these regulations or an LOA issued under Sec. Sec.  
216.106 and 218.97.


Sec.  218.94  Mitigation.

    (a) When conducting training and testing activities, as identified 
in Sec.  218.90, the mitigation measures contained in the LOA issued 
under Sec. Sec.  216.106 and 218.97 of this chapter must be 
implemented. These mitigation measures include, but are not limited to:
    (1) Lookouts--The following are protective measures concerning the 
use of lookouts.
    (i) Lookouts positioned on surface ships will be dedicated solely 
to diligent observation of the air and surface of the water. Their 
observation objectives will include, but are not limited to, detecting 
the presence of biological resources and recreational or fishing boats, 
observing buffer zones, and monitoring for vessel and personnel safety 
concerns.
    (ii) Lookouts positioned in aircraft or on boats will, to the 
maximum extent practicable and consistent with aircraft and boat safety 
and training and testing requirements, comply with the observation 
objectives described above in Sec.  218.94 (a)(1)(i).
    (iii) Lookout measures for non-impulsive sound:
    (A) With the exception of vessels less than 65 ft (20 m) in length 
and the Littoral Combat Ship (and similar vessels which are minimally 
manned), ships using low-frequency or hull-mounted mid-frequency active 
sonar sources associated with anti-submarine warfare and mine warfare 
activities at sea will have two lookouts at the forward position of the 
vessel. For the purposes of this rule, low-frequency active sonar does 
not include surface towed array surveillance system low-frequency 
active sonar.

[[Page 15439]]

    (B) While using low-frequency or hull-mounted mid-frequency active 
sonar sources associated with anti-submarine warfare and mine warfare 
activities at sea, vessels less than 65 ft (20 m) in length and the 
Littoral Combat Ship (and similar vessels which are minimally manned) 
will have one lookout at the forward position of the vessel due to 
space and manning restrictions.
    (C) Ships conducting active sonar activities while moored or at 
anchor (including pierside testing or maintenance) will maintain one 
lookout.
    (D) Ships or aircraft conducting non-hull-mounted mid-frequency 
active sonar, such as helicopter dipping sonar systems, will maintain 
one lookout.
    (E) Surface ships or aircraft conducting high-frequency or non-
hull-mounted mid-frequency active sonar activities associated with 
anti-submarine warfare and mine warfare activities at sea will have one 
lookout.
    (iv) Lookout measures for explosives and impulsive sound:
    (A) Aircraft conducting IEER sonobuoy activities and explosive 
sonobuoy exercises will have one lookout.
    (B) Surface vessels conducting anti-swimmer grenade activities will 
have one lookout.
    (C) During general mine countermeasure and neutralization 
activities using up to a 20-lb net explosive weight detonation (bin E6 
and below), vessels greater than 200 ft (61 m) will have two lookouts, 
while vessels less than 200 ft (61 m) will have one lookout.
    (D) Mine neutralization activities involving positive diver-placed 
charges using up to a 20-lb net explosive weight detonation will have 
two lookouts.
    (E) When mine neutralization activities using diver-placed charges 
with up to a 20-lb net explosive weight detonation are conducted with a 
time-delay firing device, four lookouts will be used. Two lookouts will 
be positioned in each of two small rigid hull inflatable boats. When 
aircraft are used, the pilot or member of the aircrew will serve as an 
additional lookout. The divers placing the charges on mines will report 
all marine mammal sightings to their dive support vessel.
    (F) Surface vessels or aircraft conducting gunnery exercises will 
have one lookout.
    (G) Surface vessels or aircraft conducting missile exercises 
against surface targets will have one lookout.
    (H) Aircraft conducting bombing exercises will have one lookout.
    (I) During explosive torpedo testing, one lookout will be used and 
positioned in an aircraft.
    (J) During sinking exercises, two lookouts will be used. One 
lookout will be positioned in an aircraft and one on a surface vessel.
    (K) Surface vessels conducting explosive and non-explosive large-
caliber gunnery exercises will have one lookout.
    (v) Lookout measures for physical strike and disturbance:
    (A) While underway, surface ships will have at least one lookout.
    (B) During activities using towed in-water devices, one lookout 
will be used.
    (C) Activities involving non-explosive practice munitions (e.g., 
small-, medium-, and large-caliber gunnery exercises) using a surface 
target will have one lookout.
    (D) During activities involving non-explosive bombing exercises, 
one lookout will be used.
    (2) Mitigation Zones--The following are protective measures 
concerning the implementation of mitigation zones.
    (i) Mitigation zones will be measured as the radius from a source 
and represent a distance to be monitored.
    (ii) Visual detections of marine mammals within a mitigation zone 
will be communicated immediately to a watch station for information 
dissemination and appropriate action.
    (iii) Mitigation zones for non-impulsive sound: \1\
---------------------------------------------------------------------------

    \1\ The mitigation zone will be 200 yd for low-frequency non-
hull mounted sources in bin LF4.
---------------------------------------------------------------------------

    (A) When marine mammals are detected by any means, the Navy shall 
ensure that low-frequency and hull-mounted mid-frequency active sonar 
transmission levels are limited to at least 6 dB below normal operating 
levels if any detected marine mammals are within 1,000 yd (914 m) of 
the sonar dome (the bow).
    (B) The Navy shall ensure that low-frequency and hull-mounted mid-
frequency active sonar transmissions are limited to at least 10 dB 
below the equipment's normal operating level if any detected marine 
mammals are within 500 yd (457 m) of the sonar dome.
    (C) The Navy shall ensure that low-frequency and hull-mounted mid-
frequency active sonar transmissions are ceased if any detected marine 
mammals are within 200 yd (183 m) of the sonar dome. Transmissions will 
not resume until the marine mammal has been seen to leave the area, has 
not been detected for 30 minutes, or the vessel has transited more than 
2,000 yd beyond the location of the last detection.
    (D) When marine mammals are detected by any means, the Navy shall 
ensure that high-frequency and non-hull-mounted mid-frequency active 
sonar transmission levels are ceased if any detected marine mammals are 
within 200 yd (183 m) of the source. Transmissions will not resume 
until the marine mammal has been seen to leave the area, has not been 
detected for 30 minutes, or the vessel has transited more than 2,000 yd 
beyond the location of the last detection.
    (E) Special conditions applicable for dolphins and porpoises only: 
If, after conducting an initial maneuver to avoid close quarters with 
dolphins or porpoises, the Officer of the Deck concludes that dolphins 
or porpoises are deliberately closing to ride the vessel's bow wave, no 
further mitigation actions are necessary while the dolphins or 
porpoises continue to exhibit bow wave riding behavior.
    (F) Prior to start up or restart of active sonar, operators shall 
check that the mitigation zone radius around the sound source is clear 
of marine mammals.
    (G) Generally, the Navy shall operate sonar at the lowest 
practicable level, not to exceed 235 dB, except as required to meet 
tactical training objectives.
    (iv) Mitigation zones for explosive and impulsive sound:
    (A) A mitigation zone with a radius of 600 yd (549 m) shall be 
established for IEER sonobuoys (bin E4).
    (B) A mitigation zone with a radius of 350 yd (320 m) shall be 
established for explosive sonobuoys using 0.6 to 2.5 lb net explosive 
weight (bin E3).
    (C) A mitigation zone with a radius of 200 yd (183 m) shall be 
established for anti-swimmer grenades (bin E2).
    (D) A mitigation zone ranging from 350 yd (320 m) to 500 yd (457 
m), dependent on charge size, shall be established for mine 
countermeasure and neutralization activities using positive control 
firing devices. Mitigation zone distances are specified for charge size 
in Table 9 of the preamble.
    (E) A mitigation zone with a radius of 1,000 yd (915 m) shall be 
established for mine neutralization diver placed mines using time-delay 
firing devices (bin E6).
    (F) A mitigation zone with a radius of 200 yd (183 m) shall be 
established for small- and medium-caliber gunnery exercises with a 
surface target (bin E2).
    (G) A mitigation zone with a radius of 600 yd (549 m) shall be 
established for large-caliber gunnery exercises with a surface target 
(bin E5).
    (H) A mitigation zone with a radius of 900 yd (823 m) shall be 
established for missile exercises with up to 250 lb net

[[Page 15440]]

explosive weight and a surface target (bin E9).
    (I) A mitigation zone with a radius of 2,000 yd (1.8 km) shall be 
established for missile exercises with 251 to 500 lb net explosive 
weight and a surface target (E10).
    (J) A mitigation zone with a radius of 2,500 yd (2.3 km) shall be 
established for bombing exercises (bin E12).
    (K) A mitigation zone with a radius of 2,100 yd (1.9 km) shall be 
established for torpedo (explosive) testing (bin E11).
    (L) A mitigation zone with a radius of 2.5 nautical miles shall be 
established for sinking exercises (bin E12).
    (v) Mitigation zones for vessels and in-water devices:
    (A) A mitigation zone of 500 yd (457 m) for observed whales and 200 
yd (183 m) for all other marine mammals (except bow riding dolphins) 
shall be established for all vessel movement, providing it is safe to 
do so.
    (B) A mitigation zone of 250 yd (229 m) shall be established for 
all towed in-water devices, providing it is safe to do so.
    (vi) Mitigation zones for non-explosive practice munitions:
    (A) A mitigation zone of 200 yd (183 m) shall be established for 
small, medium, and large caliber gunnery exercises using a surface 
target.
    (B) A mitigation zone of 1,000 yd (914 m) shall be established for 
bombing exercises.
    (3) Stranding Response Plan:
    (i) The Navy shall abide by the letter of the ``Stranding Response 
Plan for Major Navy Training Exercises in the MITT Study Area,'' to 
include the following measures:
    (A) Shutdown Procedures--When an Uncommon Stranding Event (USE--
defined in Sec.  218.71) occurs during a Major Training Exercise (MTE) 
in the MITT Study Area, the Navy shall implement the procedures 
described below.
    (1) The Navy shall implement a shutdown (as defined Sec.  218.71) 
when advised by a NMFS Office of Protected Resources Headquarters 
Senior Official designated in the MITT Study Area Stranding 
Communication Protocol that a USE involving live animals has been 
identified and that at least one live animal is located in the water. 
NMFS and the Navy will maintain a dialogue, as needed, regarding the 
identification of the USE and the potential need to implement shutdown 
procedures.
    (2) Any shutdown in a given area shall remain in effect in that 
area until NMFS advises the Navy that the subject(s) of the USE at that 
area die or are euthanized, or that all live animals involved in the 
USE at that area have left the area (either of their own volition or 
herded).
    (3) If the Navy finds an injured or dead animal floating at sea 
during an MTE, the Navy shall notify NMFS immediately or as soon as 
operational security considerations allow. The Navy shall provide NMFS 
with species or description of the animal(s), the condition of the 
animal(s), including carcass condition if the animal(s) is/are dead, 
location, time of first discovery, observed behavior (if alive), and 
photo or video (if available). Based on the information provided, NFMS 
will determine if, and advise the Navy whether a modified shutdown is 
appropriate on a case-by-case basis.
    (4) In the event, following a USE, that qualified individuals are 
attempting to herd animals back out to the open ocean and animals are 
not willing to leave, or animals are seen repeatedly heading for the 
open ocean but turning back to shore, NMFS and the Navy shall 
coordinate (including an investigation of other potential anthropogenic 
stressors in the area) to determine if the proximity of mid-frequency 
active sonar training activities or explosive detonations, though 
farther than 14 nautical miles from the distressed animal(s), is likely 
contributing to the animals' refusal to return to the open water. If 
so, NMFS and the Navy will further coordinate to determine what 
measures are necessary to improve the probability that the animals will 
return to open water and implement those measures as appropriate.
    (5) Within 72 hours of NMFS notifying the Navy of the presence of a 
USE, the Navy shall provide available information to NMFS (per the MITT 
Study Area Communication Protocol) regarding the location, number and 
types of acoustic/explosive sources, direction and speed of units using 
mid-frequency active sonar, and marine mammal sightings information 
associated with training activities occurring within 80 nautical miles 
(148 km) and 72 hours prior to the USE event. Information not initially 
available regarding the 80-nautical miles (148-km), 72-hour period 
prior to the event will be provided as soon as it becomes available. 
The Navy will provide NMFS investigative teams with additional relevant 
unclassified information as requested, if available.
    (b) [Reserved]


Sec.  218.95  Requirements for monitoring and reporting.

    (a) As outlined in the MITT Study Area Stranding Communication 
Plan, the Holder of the Authorization must notify NMFS immediately (or 
as soon as operational security considerations allow) if the specified 
activity identified in Sec.  218.90 is thought to have resulted in the 
mortality or injury of any marine mammals, or in any take of marine 
mammals not identified in Sec.  218.91.
    (b) The Holder of the LOA must conduct all monitoring and required 
reporting under the LOA, including abiding by the MITT Monitoring Plan.
    (c) General Notification of Injured or Dead Marine Mammals--Navy 
personnel shall ensure that NMFS (regional stranding coordinator) is 
notified immediately (or as soon as operational security considerations 
allow) if an injured or dead marine mammal is found during or shortly 
after, and in the vicinity of, an Navy training or testing activity 
utilizing mid- or high-frequency active sonar, or underwater explosive 
detonations. The Navy shall provide NMFS with species or description of 
the animal(s), the condition of the animal(s) (including carcass 
condition if the animal is dead), location, time of first discovery, 
observed behaviors (if alive), and photo or video (if available). The 
Navy shall consult the Stranding Response Plan to obtain more specific 
reporting requirements for specific circumstances.
    (d) Annual MITT Monitoring Plan Report--(1) The Navy shall submit 
an annual report describing the implementation and results of the MITT 
Monitoring Plan, described in Sec.  218.95. Data standards will be 
consistent to the extent appropriate across range complexes and study 
areas to allow for comparison in different geographic locations. 
Although additional information will be gathered, the protected species 
observers collecting marine mammal data pursuant to the MITT Monitoring 
Plan shall, at a minimum, provide the same marine mammal observation 
data required in Sec.  218.95. (2) As an alternative, the Navy may 
submit a multi-range complex annual monitoring plan report to fulfill 
this requirement. Such a report would describe progress of knowledge 
made with respect to monitoring plan study questions across all Navy 
ranges associated with the ICMP. Similar study questions shall be 
treated together so that progress on each topic shall be summarized 
across all Navy ranges. The report need not include analyses and 
content that does not provide direct assessment of cumulative progress 
on the monitoring plan study questions. The report shall be submitted 
either 90 days after the calendar year, or 90 days after the conclusion 
of the monitoring year date to be determined by the Adaptive Management 
process.

[[Page 15441]]

    (e) Annual MITT Exercise and Testing Reports--The Navy shall submit 
preliminary reports detailing the status of authorized sound sources 
within 21 days after the end of the annual authorization cycle. The 
Navy shall submit detailed reports 3 months after the anniversary of 
the date of issuance of the LOA. The detailed annual reports shall 
contain information on Major Training Exercises (MTE), Sinking Exercise 
(SINKEX) events, and a summary of sound sources used, as described 
below. The analysis in the detailed reports will be based on the 
accumulation of data from the current year's report and data collected 
from previous reports. The detailed reports shall contain information 
identified in Sec.  218.95(e)(1-5).
    (1) Major Training Exercises/SINKEX:
    (i) This section shall contain the reporting requirements for 
Coordinated and Strike Group exercises and SINKEX. Coordinated and 
Strike Group Major Training Exercises include:
    (A) Sustainment Exercise (SUSTAINEX).
    (B) Integrated ASW Course (IAC).
    (C) Composite Training Unit Exercises (COMPTUEX).
    (D) Joint Task Force Exercises (JTFEX).
    (E) Undersea Warfare Exercise (USWEX).
    (ii) Exercise information for each MTE:
    (A) Exercise designator.
    (B) Date that exercise began and ended.
    (C) Location (operating area).
    (D) Number of items or hours (per the LOA) of each sound source bin 
(impulsive and non-impulsive) used in the exercise.
    (E) Number and types of vessels, aircraft, etc., participating in 
exercise.
    (F) Individual marine mammal sighting info for each sighting for 
each MTE:
    (1) Date/time/location of sighting.
    (2) Species (if not possible, indication of whale/dolphin).
    (3) Number of individuals.
    (4) Initial detection sensor.
    (5) Indication of specific type of platform the observation was 
made from (including, for example, what type of surface vessel or 
testing platform).
    (6) Length of time observers maintained visual contact with marine 
mammal(s).
    (7) Sea state.
    (8) Visibility.
    (9) Sound source in use at the time of sighting.
    (10) 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 sound source.
    (11) Mitigation Implementation--Whether operation of sonar sensor 
was delayed, or sonar was powered or shut down, and how long the delay 
was; or whether navigation was changed or delayed.
    (12) If source in use is a hull-mounted sonar, relative bearing of 
animal from ship, and estimation of animal's motion relative to ship 
(opening, closing, parallel).
    (13) Observed behavior--Watchstanders 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.) 
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.
    (iv) Exercise information for each SINKEX:
    (A) List of the vessels and aircraft involved in the SINKEX.
    (B) Location (operating area).
    (C) Chronological list of events with times, including time of 
sunrise and sunset, start and stop time of all marine species surveys 
that occur before, during, and after the SINKEX, and ordnance used.
    (D) Visibility and/or weather conditions, wind speed, cloud cover, 
etc. throughout exercise if it changes.
    (E) Aircraft used in the surveys, flight altitude, and flight speed 
and the area covered by each of the surveys, given in coordinates, map, 
or square miles.
    (F) Passive acoustic monitoring details (number of sonobuoys, area 
and depth that was heard, detections of biologic activity, etc.).
    (G) Individual marine mammal sighting info for each sighting that 
required mitigation to be implemented:
    (1) Date/time/location of sighting.
    (2) Species (if not possible, indication of whale/dolphin).
    (3) Number of individuals.
    (4) Initial detection sensor.
    (5) Indication of specific type of platform the observation was 
made from (including, for example, what type of surface vessel or 
platform).
    (6) Length of time observers maintained visual contact with marine 
mammal(s).
    (7) Sea state.
    (8) Visibility.
    (9) Indication of whether animal is <200 yd, 200-500 yd, 500-1,000 
yd, 1,000-2,000 yd, or >2,000 yd from the target.
    (10) Mitigation implementation--Whether the SINKEX was stopped or 
delayed and length of delay.
    (11) Observed behavior--Watchstanders shall report, in plain 
language and without trying to categorize in any way, the observed 
behavior of the animals (such as animal closing to bow ride, 
paralleling course/speed, floating on surface and not swimming, etc.), 
and if any calves present.
    (H) List of the ordnance used throughout the SINEKX and net 
explosive weight (NEW) of each weapon and the combined NEW.
    (2) Summary of Sources Used.
    (i) This section shall include the following information summarized 
from the authorized sound sources used in all training and testing 
events:
    (A) Total annual or quantity (per the LOA) of each bin of sonar or 
other non-impulsive source;
    (B) Total annual expended/detonated rounds (missiles, bombs, etc.) 
for each explosive bin; and
    (C) Improved Extended Echo-Ranging System (IEER)/sonobuoy summary, 
including:
    (1) Total expended/detonated rounds (buoys).
    (2) Total number of self-scuttled IEER rounds.
    (3) Sonar Exercise Notification--The Navy shall submit to NMFS 
(specific contact information to be provided in the LOA) either an 
electronic (preferably) or verbal report within 15 calendar days after 
the completion of any major exercise indicating:
    (i) Location of the exercise.
    (ii) Beginning and end dates of the exercise.
    (iii) Type of exercise.
    (4) Geographic Information Presentation--The reports shall present 
an annual (and seasonal, where practical) depiction of training 
exercises and testing bin usage geographically across the Study Area.
    (5) 5-year Close-out Exercise and Testing Report--This report will 
be included as part of the 2020 annual exercise or testing report. This 
report will provide the annual totals for each sound source bin with a 
comparison to the annual allowance and the 5-year total for each sound 
source bin with a comparison to the 5-year allowance. Additionally, if 
there were any changes to the sound source allowance, this report will 
include a discussion of why the change was made and include the 
analysis to support how the change did or did not result in a change in 
the FEIS and final rule determinations. The

[[Page 15442]]

report will be submitted 3 months after the expiration of the rule. 
NMFS will submit comments on the draft close-out report, if any, within 
3 months of receipt. The report will be considered final after the Navy 
has addressed NMFS' comments, or 3 months after the submittal of the 
draft if NMFS does not provide comments.


Sec.  218.96  Applications for Letters of Authorization.

    To incidentally take marine mammals pursuant to the regulations in 
this subpart, the U.S. citizen (as defined by Sec.  216.106 of this 
chapter) conducting the activity identified in Sec.  218.90(c) (the 
U.S. Navy) must apply for and obtain either an initial LOA in 
accordance with Sec.  218.97 or a renewal under Sec.  218.98.


Sec.  218.97  Letters of Authorization.

    (a) An LOA, unless suspended or revoked, will be valid for a period 
of time not to exceed the period of validity of this subpart.
    (b) Each LOA will set forth:
    (1) Permissible methods of incidental taking;
    (2) Means of effecting the least practicable adverse impact on the 
species, its habitat, and on the availability of the species for 
subsistence uses (i.e., mitigation); and
    (3) Requirements for mitigation, monitoring and reporting.
    (c) Issuance and renewal of the LOA will be based on a 
determination that the total number of marine mammals taken by the 
activity as a whole will have no more than a negligible impact on the 
affected species or stock of marine mammal(s).


Sec.  218.98  Renewals and Modifications of Letters of Authorization.

    (a) A Letter of Authorization issued under Sec. Sec.  216.106 and 
218.97 of this chapter for the activity identified in Sec.  218.90(c) 
will be renewed or modified upon request of the applicant, provided 
that:
    (1) The proposed specified activity and mitigation, monitoring, and 
reporting measures, as well as the anticipated impacts, are the same as 
those described and analyzed for these regulations (excluding changes 
made pursuant to the adaptive management provision of this chapter), 
and;
    (2) NMFS determines that the mitigation, monitoring, and reporting 
measures required by the previous LOA under these regulations were 
implemented.
    (b) For LOA modification or renewal requests by the applicant that 
include changes to the activity or the mitigation, monitoring, or 
reporting (excluding changes made pursuant to the adaptive management 
provision of this chapter) that do not change the findings made for the 
regulations or result in no more than a minor change in the total 
estimated number of takes (or distribution by species or years), NMFS 
may publish a notice of proposed LOA in the Federal Register, including 
the associated analysis illustrating the change, and solicit public 
comment before issuing the LOA.
    (c) An LOA issued under Sec.  216.106 and Sec.  218.97 of this 
chapter for the activity identified in Sec.  218.94 of this chapter may 
be modified by NMFS under the following circumstances:
    (1) Adaptive Management--NMFS may modify (including augment) the 
existing mitigation, monitoring, or reporting measures (after 
consulting with the Navy regarding the practicability of the 
modifications) if doing so creates a reasonable likelihood of more 
effectively accomplishing the goals of the mitigation and monitoring 
set forth in the preamble for these regulations.
    (i) Possible sources of data that could contribute to the decision 
to modify the mitigation, monitoring, and reporting measures in an LOA:
    (A) Results from Navy's monitoring from the previous year(s);
    (B) Results from other marine mammal and/or sound research or 
studies; or
    (C) Any information that reveals marine mammals may have been taken 
in a manner, extent, or number not authorized by these regulations or 
subsequent LOAs.
    (ii) If, through adaptive management, the modifications to the 
mitigation, monitoring, or reporting measures are substantial, NMFS 
would publish a notice of proposed LOA in the Federal Register and 
solicit public comment.
    (2) Emergencies--If NMFS determines that an emergency exists that 
poses a significant risk to the well-being of the species or stocks of 
marine mammals specified in Sec.  218.92(c), an LOA may be modified 
without prior notification and an opportunity for public comment. 
Notification would be published in the Federal Register within 30 days 
of the action.

[FR Doc. 2014-05833 Filed 3-18-14; 8:45 am]
BILLING CODE 3510-22-P