[Federal Register Volume 74, Number 201 (Tuesday, October 20, 2009)]
[Proposed Rules]
[Pages 53796-53873]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-24837]



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Part II





Department of Commerce





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National Oceanic and Atmospheric Administration



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50 CFR Part 218



Taking and Importing Marine Mammals; Military Training Activities and 
Research, Development, Testing and Evaluation Conducted Within the 
Mariana Islands Range Complex (MIRC); Proposed Rule

Federal Register / Vol. 74 , No. 201 / Tuesday, October 20, 2009 / 
Proposed Rules

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 218

[Docket No. 0907281180-91190-01]
RIN 0648-AX90


Taking and Importing Marine Mammals; Military Training Activities 
and Research, Development, Testing and Evaluation Conducted Within the 
Mariana Islands Range Complex (MIRC)

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Proposed rule; request for comments.

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SUMMARY: NMFS has received a request from the U.S. Navy (Navy) for 
authorization for the Department of Defense (including the Navy, the 
U.S. Air Force (USAF), and the U.S. Marine Corps (USMC)) to take marine 
mammals incidental to training activities conducted in the Mariana 
Islands Range Complex (MIRC) study area for the period of March 2010 
through February 2015 (amended from the initial request for January 
2010 through December 2014). Pursuant to the Marine Mammal Protection 
Act (MMPA), NMFS is proposing regulations to govern that take and 
requesting information, suggestions, and comments on these proposed 
regulations.

DATES: Comments and information must be received no later than November 
19, 2009.

ADDRESSES: You may submit comments, identified by 0648-AX90, by any one 
of the following methods:
    <bullet> Electronic Submissions: Submit all electronic public 
comments via the Federal eRulemaking Portal http://www.regulations.gov.
    <bullet> Hand delivery or mailing of paper, disk, or CD-ROM 
comments should be addressed to Michael Payne, Chief, Permits, 
Conservation and Education Division, Office of Protected Resources, 
National Marine Fisheries Service, 1315 East-West Highway, Silver 
Spring, MD 20910-3225.
    Instructions: All comments received are a part of the public record 
and will generally be posted to http://www.regulations.gov without 
change. All Personal Identifying Information (for example, name, 
address, etc.) voluntarily submitted by the commenter may be publicly 
accessible. Do not submit Confidential Business Information or 
otherwise sensitive or protected information.
    NMFS will accept anonymous comments (enter N/A in the required 
fields if you wish to remain anonymous). Attachments to electronic 
comments will be accepted in Microsoft Word, Excel, WordPerfect, or 
Adobe PDF file formats only.

FOR FURTHER INFORMATION CONTACT: Jolie Harrison, Office of Protected 
Resources, NMFS, (301) 713-2289, ext. 166.

SUPPLEMENTARY INFORMATION:

Availability

    A copy of the Navy's application, as well as the draft Monitoring 
Plan and the draft Stranding Response Plan for MIRC, may be obtained by 
writing to the address specified above (see ADDRESSES), telephoning the 
contact listed above (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 (DEIS) for MIRC was published on January 30, 2009, and may be 
viewed at http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. NMFS is participating in the development 
of the Navy's EIS as a cooperating agency under NEPA.

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce (Secretary) to allow, upon request, 
the incidental, but not intentional taking of marine mammals by U.S. 
citizens who engage in a specified activity (other than commercial 
fishing) during periods of not more than five consecutive years each if 
certain findings are made and regulations are issued or, if the taking 
is limited to harassment, notice of a proposed authorization is 
provided to the public for review.
    Authorization 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, and if the permissible methods of taking 
and requirements pertaining to the mitigation, monitoring and reporting 
of such taking 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) modified the MMPA by removing the ``small numbers'' and 
``specified geographical region'' limitations 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

    In August 2008, NMFS received an application from the Navy (which 
was updated in February, March, and June 2009) requesting authorization 
for the take of individuals of 28 species of marine mammals incidental 
to upcoming Department of Defense (including Navy, USMC, and USAF) 
training activities to be conducted from March 2010 through February 
2015 within the MIRC study area, which encompasses a 501,873-square-
nautical mile (nm\2\) area around the islands of Guam, Tinian, Saipan, 
Rota, Fallaron de Medenillia, and others and includes ocean areas in 
both the Pacific Ocean and the Philippine Sea. These training 
activities are classified as military readiness activities under the 
provisions of the NDAA. The Navy states, and NMFS concurs, that these 
military readiness activities may incidentally take marine mammals 
present within the MIRC Study Area by exposing them to sound from mid-
frequency or high frequency active sonar (MFAS/HFAS) or underwater 
detonations. The Navy requests authorization to take individuals of 27 
species of marine mammals by Level B Harassment and 2 individuals of 2 
species by Level A Harassment, although injury will likely be avoided 
through the implementation of the Navy's proposed mitigation measures. 
Further, although it does not anticipate that it will occur, the Navy 
requests authorization to take, by injury or mortality, up to 10 beaked 
whales over the course of the 5-yr regulations.

Description of Specified Activities

Purpose and Background

    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

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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 weapons systems.
    The specified training and RDT&E activities addressed in this 
proposed rule are a subset of the Proposed Action described in the MIRC 
DEIS, which would support and maintain Department of Defense training 
and assessments of current capabilities, RDT&E activities, and 
associated range capabilities (including hardware and infrastructure 
improvements in the MIRC). Training and RDT&E do not include combat 
operations, operations in direct support of combat, or other activities 
conducted primarily for purposes other than training. The Department of 
Defense proposes to implement actions within the MIRC to:
    <bullet> Maintain baseline training and RDT&E activities at 
mandated levels;
    <bullet> Provide the potential to increase training activities and 
exercises from current levels;
    <bullet> Accommodate increased readiness activities associated with 
the force structure changes (human resources, new platforms, additional 
weapons systems, including underwater tracking capabilities and 
training activities to support Intelligence, Surveillance, 
Reconnaissance, Strike [ISR/Strike]); and
    <bullet> Implement range complex investment strategies that 
sustain, upgrade, modernize, and transform the MIRC to accommodate 
increased use and more realistic training scenarios.
    The proposed action would result in the following increases (above 
those conducted in previous years, i.e., the No Action Alternative in 
the Navy's DEIS) in activities associated with the annual take of 
marine mammals:
    <bullet> Multistrike Exercises and Joint Expeditionary Exercises 
(most extensive at sea exercises utilizing MFAS)--increase from one 
exercise in alternate years to one exercise every year.
    <bullet> Other Major Exercises utilizing MFAS (shorter and less 
MFAS use)--increase from 1 to 7 exercises.
    <bullet> Unit Level Anti-submarine Warfare (ASW) Exercises (TRACKEX 
and TORPEX)--an increase from 34 to 83 exercises.
    <bullet> Mine Warfare Exercises--an increase from 32 to 53 
exercises.
    <bullet> Bombing Exercises (non-inert)--an increase from 1 to 4 
exercises.
    <bullet> Sinking Exercises--an increase from 1 to 2 exercises.
    <bullet> Gunnery Exercises--an increase from 32 to 54 exercises.
    <bullet> Missile Exercises (Air to Surface, live HELLFIRE 
missile)--an increase from 0 to 2 exercises.

Overview of the MIRC

    The U.S. military has been training and operating in the area now 
defined as the MIRC for over 100 years. The MIRC Study Area (see figure 
1-1 in the Navy's application) is located in the Western Pacific 
(WestPac) and consists of three primary components: ocean surface and 
undersea areas, special use airspace (SUA), and training land areas. 
The ocean surface and undersea areas extend from the international 
waters south of Guam to north of Pagan (CNMI), and from the Pacific 
Ocean east of the Mariana Islands to the middle of the Philippine Sea 
to the west, encompassing 501,873 square nautical miles (nm\2\) 
(1,299,851 square kilometers [km\2\]) of open ocean and littorals 
(coastal areas). The MIRC Study Area includes ocean areas in the 
Philippine Sea, Pacific Ocean, and exclusive economic zones (EEZs) of 
the United States and Federal States of Micronesia (FSM). The MIRC 
Study Area includes land ranges and training area/facilities on Guam, 
Rota, Tinian, Saipan, and Farallon de Medinilla (FDM), encompassing 64 
nm\2\ (220 km\2\) of land. Special Use Airspace (SUA) consists of 
Warning Area 517 (W-517), restricted airspace over FDM (R-7201), and 
Air Traffic Control Assigned Airspace (ATCAA) encompassing 63,000 nm\2\ 
(216,000 km\2\) of airspace. For range management and scheduling 
purposes, the MIRC is divided into training areas under different 
controlling authorities.
    Guam is located roughly three quarters of the distance from Hawaii 
to the Philippines, about 1,600 miles east of Manila and 1,550 miles 
southeast of Tokyo. The southern extent of the Commonwealth of the 
Northern Mariana Islands (CNMI) is located 40 miles north of Guam (Rota 
Island) and extends 330 miles to the northwest. Saipan, the CNMI 
capital, is 3,300 miles west of Honolulu and 1,470 miles south-
southeast of Tokyo. The MIRC is of particular significance for the 
training of U.S. military forces in the Western Pacific because of its 
location. As the westernmost complex in U.S. territory, it provides the 
only opportunity for forward-deployed U.S. forces to train on U.S.-
owned lands without having to return to Hawaii or the continental 
United States.
    The seafloor of the MIRC is characterized by the Mariana Trench, 
the Mariana Basin, the Mariana Ridge, ridges, numerous seamounts, 
hydrothermal vents, and volcanic activity. These areas are comprised of 
very deep water with a very rapid transition from the shelf to deep 
water. The Mariana Trench is located east to south-east of Guam and the 
Mariana Islands and is characterized by deep depths of 16,404 to 32,808 
feet [ft] (5,000 to 10,000 m) (Fryer et al., 2003). The Mariana Basin 
is located west of Guam and the Mariana Islands, and is characterized 
by an average depth of 11,483 ft (Taylor and Martinez 2003; Yamazaki et 
al., 1993). The Mariana Ridge consists of Guam and the Mariana Islands 
and the waters out to the Mariana Trench, and is characterized by 
shallow water transitioning to deep water of 11,483 ft (3,500 m) 
(Taylor and Martinez 2003; Yamazaki et al., 1993). The bottom substrate 
covering the seafloor in the MIRC is primarily volcanic or marine in 
nature (Eldredge, 1983).
    The waters of the MIRC Study Area undergo an annual cycle of 
temperature change, however this temperature flux is only a few degrees 
each year, as would be expected from a tropical climate. The 
temperature throughout the year ranges from about 25[deg] to 31 [deg]C 
with an annual mean temperature of 27[deg] to 28 [deg]C for the years 
ranging from 1984 to 2003 (National Oceanic and Atmospheric 
Administration [NOAA] 2004). Temperatures increase during the summer 
and autumn months with peak temperatures occurring in September/
October.
    The water column in the MIRC Study Area contains a well-mixed 
surface layer ranging from 295 ft to 410 ft (90 to 125 m). Immediately 
below the mixed layer is a rapid decline in temperature to the cold 
deeper waters. Unlike more temperate climates, the thermocline is 
relatively stable, rarely turning over and mixing the more nutrient-
rich waters of the deeper ocean in to the surface layer. This 
constitutes what has been defined as a ``significant'' surface duct (a 
mixed layer of constant water temperature extending from the sea 
surface to 100 feet or more), which influences the transmission of 
sound in the water. This factor has been included in the modeling 
analysis of marine mammal impacts.

Marianas Trench Marine National Monument

    The Marianas Trench Marine National Monument (the `Monument') was

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established in January 2009 by Presidential Proclamation under the 
authority of the Antiquities Act (16 U.S.C. 431). The Monument consists 
of approximately 71,897 square nautical miles (246,600 square 
kilometers) of submerged lands and waters of the Mariana Archipelago 
and was designated with the purpose of protecting the submerged 
volcanic areas of the Mariana Ridge, the coral reef ecosystems of the 
waters surrounding the islands of Farallon de Pajaros, Maug, and 
Asuncion in the Commonwealth of the Northern Mariana Islands, and the 
Mariana Trench. The Monument includes the waters and submerged lands of 
the three northernmost Mariana Islands (the `Islands Unit') and only 
the submerged lands of designated volcanic sites (the `Volcanic Unit') 
and the Mariana Trench (the `Trench Unit') to the extent described as 
follows: The seaward boundaries of the Islands Unit of the monument 
extend to the lines of latitude and longitude which lie approximately 
50 nautical miles (93 kilometers) from the mean low water line of 
Farallon de Pajaros (Uracas), Maug, and Asuncion. The inland boundary 
of the Islands Unit of the monument is the mean low water line. The 
boundary of the Trench Unit of the Monument extends from the northern 
limit of the EEZ of the United States in the Commonwealth of the 
Northern Mariana Islands to the southern limit of the Exclusive 
Economic Zone of the United States in Guam approximately following the 
points of latitude and longitude identified in Figure 3.6-1 of the MIRC 
DEIS. The boundaries of the Volcanic Unit of the Monument include a 1 
nautical mile radius centered on each of the islands' volcanic 
features.
    The Monument contains objects of scientific interest, including the 
largest active mud volcanoes on Earth. The Champagne vent, located at 
the Eifuku submarine volcano, produces almost pure liquid carbon 
dioxide. This phenomenon has only been observed at one other site in 
the world. The Sulfur Cauldron, a pool of liquid sulfur, is found at 
the Daikoku submarine volcano. The only other known location of molten 
sulfur is on Io, a moon of Jupiter. Unlike other reefs across the 
Pacific, the northernmost Mariana reefs provide unique volcanic 
habitats that support marine biological communities requiring basalt. 
Maug Crater represents one of only a handful of places on Earth where 
photosynthetic and chemosynthetic communities of life are known to come 
together.
    The waters of the Monument's northern islands are among the most 
biologically diverse in the Western Pacific and include the greatest 
diversity of seamount and hydrothermal vent life yet discovered. These 
volcanic islands are ringed by coral ecosystems with very high numbers 
of apex predators, including large numbers of sharks. They also contain 
one of the most diverse collections of stony corals in the Western 
Pacific. The northern islands and shoals in the Monument have 
substantially higher large fish biomass, including apex predators, than 
the southern islands and Guam. The waters of Farallon de Pajaros (also 
known as Uracas), Maug, and Asuncion support some of the largest 
biomass of reef fishes in the Mariana Archipelago.
    A portion of the Monument lies within the MIRC, including a small 
area on the northern border of the MIRC as well as the Volcanic Unit 
and the Trench Unit (See Figure 3.6-1). Any of the activities 
identified under the Proposed Action could take place within areas 
included in the Monument, where they overlap. The Presidential 
Proclamation establishing the Monument indicates that the prohibitions 
required by the Proclamation shall not apply to activities and 
exercises of the Armed Forces, but also that the Armed Forces shall 
ensure, by the adoption of appropriate measures not impairing 
operations or operational capabilities, that its vessels and aircraft 
act in a manner consistent, so far as is reasonable and practicable, 
with the Proclamation.

Specified Activities

    As mentioned above, the Navy has requested MMPA authorization to 
take marine mammals incidental to training or RDT&E activities in the 
MIRC that would result in the generation of sound or pressure waves in 
the water at or above levels that NMFS has determined will likely 
result in take (see Acoustic Take Criteria Section), either through the 
use of MFAS/HFAS or the detonation of explosives in the water. These 
activities are discussed in the subsections below. In addition to use 
of active sonar sources and explosives, these activities include the 
operation and movement of vessels that are necessary to conduct the 
training, and the effects of this part of the activities are also 
analyzed in this document.
    The Navy's application also briefly summarizes Maritime and Air 
Interdiction of Maritime Targets and Air Combat Maneuvers; however, 
these activities are primarily air based and do not utilize sound 
sources or explosives in the water. No take of marine mammals is 
anticipated to result from these activities and, therefore, they are 
not discussed further.

Activities Utilizing Active Sonar Sources

    For the MIRC, the training activities that utilize active tactical 
sonar sources fall primarily into the category of Anti-submarine 
Warfare (ASW). This section includes a description of ASW, the active 
acoustic devices used in ASW exercises, and the exercise types in which 
these acoustic sources are used.

ASW Training and Active Sonar

    ASW involves helicopter and sea control aircraft, ships, and 
submarines, operating alone or in combination, to locate, track, and 
neutralize submarines. Various types of active and passive sonars are 
used by the Navy to determine water depth, locate mines, and identify, 
track, and target submarines. Passive sonar ``listens'' for sound waves 
by using underwater microphones, called hydrophones, which receive, 
amplify and process underwater sounds. No sound is introduced into the 
water when using passive sonar. Passive sonar can indicate the 
presence, character and movement of submarines. However, passive sonar 
provides information about only the bearing (direction) to a sound-
emitting source; it does not provide an accurate range (distance) to 
the source. Also, passive sonar relies on the underwater target itself 
to provide sufficient sound to be detected by hydrophones. Active sonar 
is needed to locate objects that emit little or no noise (such as mines 
or diesel-electric submarines operating in electric mode) and to 
establish both bearing and range to the detected contact.
    Active sonar transmits pulses of sound that travel through the 
water, reflect off objects and return to a receiver. By knowing the 
speed of sound in water and the time taken for the sound wave to travel 
to the object and back, active sonar systems can quickly calculate 
direction and distance from the sonar platform to the underwater 
object. There are three types of active sonar: Low frequency, mid-
frequency, and high-frequency.
    MFAS, as defined in the Navy's MIRC LOA application, operates 
between 1 and 10 kHz, with detection ranges up to 10 nm (19 km). 
Because of this detection ranging capability, MFAS is the Navy's 
primary tool for conducting ASW. Many ASW experiments and exercises 
have demonstrated that the improved capability (of MFAS over other 
sources) for long range detection of adversary submarines before they 
are able to conduct an attack is essential to U.S.

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ship survivability. Today, ASW is the Navy's number one war-fighting 
priority. Navies across the world utilize modern, quiet, diesel-
electric submarines that pose the primary threat to the U.S. Navy's 
ability to perform a number of critical missions. Extensive training is 
necessary if Sailors on ships and in strike groups are to gain 
proficiency in using MFAS. If a strike group does not demonstrate MFAS 
proficiency, it cannot be certified as combat ready.
    HFAS, as defined in the Navy's MIRC LOA application, operates at 
frequencies greater than 10 kilohertz (kHz). At higher acoustic 
frequencies, sound rapidly dissipates in the ocean environment, 
resulting in short detection ranges, typically less than five nm (9 
km). High-frequency sonar is used primarily for determining water 
depth, hunting mines and guiding torpedoes.
    Surveillance Towed Array Sensor System Low Frequency Active 
(SURTASS LFA) sonar operates below 1 kHz and is designed to detect 
extremely quiet diesel-electric submarines at ranges far beyond the 
capabilities of MFA sonars. There are currently only two ships in use 
by the Navy that are equipped with LFA sonar; both are ocean 
surveillance vessels operated by Military Sealift Command (MSC).

Acoustic Sources Used for ASW Exercises in the MIRC

    Modern sonar technology has developed a multitude of sonar sensor 
and processing systems. In concept, the simplest active sonars emit 
omni-directional pulses (``pings'') and time the arrival of the 
reflected echoes from the target object to determine range. More 
sophisticated active sonar emits an omni-directional ping and then 
rapidly scans a steered receiving beam to provide directional, as well 
as range, information. More advanced active sonars transmit multiple 
preformed beams, listening to echoes from several directions 
simultaneously and providing efficient detection of both direction and 
range. The types of active sonar sources employed during ASW active 
sonar training exercises in the MIRC are identified in Table 1.
    The SURTASS LFA system may also be used during some of the Navy's 
training and testing scenarios within the MIRC Study Area (see SURTASS 
LFA subsection below), however, that system's use was analyzed in other 
environmental documentation (DON 1999, 2002b, 2007a; NOAA 2002a, 2007).
BILLING CODE 3510-22-P

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[GRAPHIC] [TIFF OMITTED] TP20OC09.000

BILLING CODE 3510-22-C

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    ASW sonar systems are deployed from certain classes of surface 
ships, submarines, helicopters, and fixed-wing maritime patrol aircraft 
(MPA). Maritime patrol aircraft is a category of fixed-wing aircraft 
that includes the current P-3C Orion, and the future P-8 Poseidon 
multimission maritime aircraft. The surface ships used are typically 
equipped with hull-mounted sonars (passive and active) for the 
detection of submarines. Fixed-wing MPA are used to deploy both active 
and passive sonobuoys to assist in locating and tracking submarines or 
ASW targets during the exercise. Helicopters are used to deploy both 
active and passive sonobuoys to assist in locating and tracking 
submarines or ASW targets during the exercise, and to deploy dipping 
sonar. Submarines are equipped with passive sonar sensors used to 
locate and prosecute other submarines and/or surface ships during the 
exercise. The platforms used in ASW exercises are identified below.
    Surface Ship Sonars--A variety of surface ships participate in 
training events, including the Fast Frigate (FFG) and the Guided 
Missile Destroyer (DDG), and the guided missile cruiser (CG). These 
three classes of ship are equipped with active as well as passive 
tactical sonars for mine avoidance and submarine detection and 
tracking. DDG and CG class ships are equipped with the AN/SQS-53 sonar 
system (the most powerful system), with a nominal source level of 235 
decibels (dB) re 1 [mu]Pa @ 1 m. The FFG class ship uses the SQS-56 
sonar system, with a nominal source level of 225 decibels (dB) re 1 
[mu]Pa @ 1 m. Sonar ping transmission durations were modeled as lasting 
1 second per ping and omni-directional, which is a conservative 
assumption that will overestimate potential effects. Actual ping 
durations will be less than 1 second. The AN/SQS-53 hull-mounted sonar 
transmits at a center frequency of 3.5 kHz. The SQS-56 transmits at a 
center frequency of 7.5 kHz. Details concerning the tactical use of 
specific frequencies and the repetition rate for the sonar pings is 
classified but was modeled based on the required tactical training 
setting.
    Submarine Sonars--Submarine sonars (e.g., AN/BQQ-10) are used to 
detect and target enemy submarines and surface ships. Because submarine 
active sonar use is very rare and in those rare instances, very brief, 
it is extremely unlikely that use of active sonar by submarines would 
have any measurable effect on marine mammals. In addition, submarines 
have a high frequency AN/BQS-15 sonar used for navigation safety and 
mine avoidance that is not unlike a fathometer in source level or 
output. There is, at present, no mine training range in the MIRC area. 
Therefore, given its limited use and rapid attenuation as a high 
frequency source, the AN/BQS-15 is not expected to result in the take 
of marine mammals.
    Aircraft Sonar Systems--Aircraft sonar systems that would operate 
in the MIRC include sonobuoys and dipping sonar. Sonobuoys may be 
deployed by maritime patrol aircraft or helicopters; dipping sonars are 
used by carrier-based helicopters. A sonobuoy is an expendable device 
used by aircraft for the detection of underwater acoustic energy and 
for conducting vertical water column temperature measurements. Most 
sonobuoys are passive, but some can generate active acoustic signals, 
as well. Dipping sonar is an active or passive sonar device lowered on 
cable by helicopters to detect or maintain contact with underwater 
targets. During ASW training, these systems' active modes are only used 
briefly for localization of contacts and are not used in primary search 
capacity.
    Extended Echo Ranging and Improved Extended Echo Ranging (EER/IEER) 
Systems--EER/IEER are airborne ASW systems used to conduct ``large 
area'' searches for submarines. These systems are made up of airborne 
avionics ASW acoustic processing and sonobuoy types that are deployed 
in pairs. The EER/IEER System's active sonobuoy component, the AN/SSQ-
110A Sonobuoy, generates an explosive sound impulse and a passive 
sonobuoy (ADAR, AN/SSQ-101A) that would ``listen'' for the return echo 
that has been bounced off the surface of a submarine. These sonobuoys 
are designed to provide underwater acoustic data necessary for naval 
aircrews to quickly and accurately detect submerged submarines. The 
sonobuoy pairs are dropped from a maritime patrol aircraft into the 
ocean in a predetermined pattern with a few buoys covering a very large 
area. The AN/SSQ-110A Sonobuoy Series is an expendable and commandable 
sonobuoy. Upon command from the aircraft, the explosive charge would 
detonate, creating the sound impulse. Within the sonobuoy pattern, only 
one detonation is commanded at a time. Twelve to twenty SSQ-110A source 
sonobuoys are used in a typical exercise. Both charges of each sonobuoy 
would be detonated independently during the course of the training, 
either tactically to locate the submarine, or when the sonobuoys are 
commanded to scuttle at the conclusion of the exercise. The AN/SSQ-110A 
is listed in Table 1 because it functions like a sonar ping, however, 
the source creates an explosive detonation and its effects are 
considered in the underwater explosive section.
    Advanced Extended Echo Ranging (AEER) System--The proposed AEER 
system is operationally similar to the existing EER/IEER system. The 
AEER system will use the same ADAR sonobuoy (SSQ-101A) as the acoustic 
receiver and will be used for a large area ASW search capability in 
both shallow and deep water. However, instead of using an explosive AN/
SQS-110A as an impulsive source for the active acoustic wave, the AEER 
system will use a battery powered (electronic) source for the AN/SSQ 
125 sonobuoy. The output and operational parameters for the AN/SSQ-125 
sonobuoy (source levels, frequency, wave forms, etc.) are classified. 
However, this sonobuoy is intended to replace the EER/IEER's use of 
explosives and is scheduled to enter the fleet in 2011. For purposes of 
analysis, replacement of the EER/IEER system by the AEER system will be 
assumed to occur at 25% per year as follows: 2011--25% replacement; 
2012--50% replacement; 2013--75% replacement; 2014--100% replacement 
with no further use of the EER/IEER system beginning in 2015 and 
beyond.
    Torpedoes--Torpedoes are the primary ASW weapon used by surface 
ships, aircraft, and submarines. The guidance systems of these weapons 
can be autonomous or electronically controlled from the launching 
platform through an attached wire. The autonomous guidance systems are 
acoustically based. They operate either passively, exploiting the 
emitted sound energy by the target, or actively, ensonifying the target 
and using the received echoes for guidance. The MK-48 submarine-
launched torpedo was modeled for active sonar transmissions as a high 
frequency source during specified training activities within the MIRC. 
The use of the less powerful MK-46 and MK-54 torpedoes will also occur 
in the MIRC, however, their use was accounted for by modeling all 
torpedo use in MIRC as if they were MK-48 torpedoes.
    Portable Undersea Tracking Range--The Portable Undersea Tracking 
Range (PUTR) would be developed to support ASW training in areas where 
the ocean depth is between 400 m and 3500 m. In MIRC it would likely be 
deployed in a TORPEX area or in W-517. This system would temporarily 
instrument up to a 100 square-nautical mile or smaller areas on the 
seafloor, and would provide high fidelity crew feedback and scoring of 
crew performance during ASW training activities. No on-shore

[[Page 53802]]

construction would take place. Seven electronics packages, each 
approximately 3 ft long by 2 ft in diameter, would be temporarily 
installed on the seafloor by a range boat. The anchors used to keep the 
electronics packages on the seafloor are made of steel, approximately 
1.5 ft-by-1.5 ft and 300 pounds. PUTR use is planned for Navy training 
areas other than MIRC including the Northwest Training Range Complex 
and Gulf of Alaska. PUTR equipment can be recovered for maintenance or 
when training is completed. The Navy proposes to deploy this system 
year round, and to conduct TRACKEX and TORPEX activities for up to 35 
days per year at any time of year. During each of the 35 days of annual 
operation, the PUTR would be in use for up to 8 hours each day. Two 
separate sound sources are associated with the operation of the PUTR:
    <bullet> Range tracking pingers--Range tracking pingers would be 
used on ships, submarines, and ASW targets when training is conducted 
on the PUTR. A typical MK 84 range tracking pinger generates a 12.9 kHz 
pulse with a duty cycle of 15 milliseconds and has a design power of 
194 dB re 1 micro-Pascal at 1 meter. Ping rate is selectable and 
typically one pulse every two seconds. Under the proposed action, up to 
four range pingers would operate simultaneously for 8 hours each of the 
35 PUTR operating days per year. Total time operated would be 280 hours 
annually.
    <bullet> Transponders--Each transponder package consists of a 
hydrophone that receives pinger signals, and a transducer that sends an 
acoustic ``uplink'' of locating data to the range boat. The uplink 
signal is transmitted at 8.8 kilohertz (kHz) or 40 kHz, at a source 
level of 190 decibels (dB) at 40 kHz, and 186 dB at 8.8 kHz. The uplink 
frequency is selectable and typically uses the 40 kHz signal, however 
the lower frequency may be used when PUTR is deployed in deep waters 
where conditions may not permit the 40 kHz signal to establish and 
maintain the uplink. The PUTR system also incorporates an emergency 
underwater voice capability that transmits at 8-11 kHz and a source 
level of 190 dB. Under the proposed action, the uplink transmitters 
would operate 35 days per year, for 8 hours each day of use. Total time 
operated would be 280 hours annually.
    Acoustic Device Countermeasures (ADCs)--ADCs (e.g., AN/SLQ-25 
(``NIXIE''), MK-2 and MK-3 are, in effect, decoys to avert localization 
and/or torpedo attacks. These do not represent a significant source of 
sound given their intermittent use and operational characteristics 
(source output level and/or frequency). Given the sporadic use of these 
devices, the potential to affect marine mammals is unlikely, therefore 
these sources were not modeled or considered further in this analysis.
    Training Targets--ASW training targets are used to simulate 
opposition submarines. They are equipped with one or a combination of 
the following devices: (1) Acoustic projectors emanating sounds to 
simulate submarine acoustic signatures, (2) echo repeaters to simulate 
the characteristics of the echo of a particular sonar signal reflected 
from a specific type of submarine, and (3) magnetic sources to trigger 
magnetic detectors. Based on the operational characteristics (source 
output level and/or frequency) of these acoustic sources, the potential 
to affect marine mammals is unlikely, and therefore they were not 
modeled for this analysis.
    SURTASS LFA--SURTASS LFA is a long-range, all-weather, sonar system 
that operates in the low frequency band (100-500 Hz). The system has 
both passive and active components. The active system component, LFA, 
is an augmentation to the passive detection system, and is planned for 
use when passive system performance proves inadequate. LFA is a set of 
acoustic transmitting source elements suspended by cable from 
underneath a ship. These elements, called projectors, are devices that 
produce the active sound pulse, or ping. The projectors transform 
electrical energy to mechanical energy that set up vibrations or 
pressure disturbances within the water to produce a ping. The passive, 
or listening, part of the system is SURTASS, which detects returning 
echoes from submerged objects, such as submarines, through the use of 
hydrophones. The SURTASS hydrophones are mounted on a receive array 
that is towed behind the vessel. The return signals or echoes, which 
are usually below background or ambient sound level, are then processed 
and evaluated to identify and classify potential underwater targets.
    In the MIRC Study Area, the military intends to conduct three 
exercises (multi-strike group exercises) that will include an LFA 
component during a five-year period that may include both SURTASS LFA 
and MFA active sonar sources. The expected duration of these combined 
exercises is approximately 14 days. Based on an exercise of this 
length, an LFA system would be active (i.e., actually transmitting) for 
no more than approximately 25 hours. In the combined exercise, LFA 
sonar is used as a long-range search tool (to find a potential target 
at long range) while MFA sonar is generally used as a closer-range 
search tool (to find a target at closer range). The LFA sonar and the 
MFA sonar would not normally be operated in close proximity to each 
other. Tactical and technical considerations dictate that the LFA ship 
would typically be tens of miles from the MFA ship when using active 
sonar.
    Analysis of the environmental impacts of the SURTASS LFA system, 
including the potential for synergistic and cumulative effects with 
MFAS operation, was previously presented in a series of Navy EISs and 
the August, 2009 biological opinion for SURTASS LFA 2009 LOA, and the 
take of marine mammals incidental to the operation of LFA in the MIRC 
and elsewhere has been previously authorized by NOAA/NMFS (2002a, 
2007). Although the authorization of take of marine mammals incidental 
to the operation of LFA sonar will not be considered here, NMFS 
describes and considers the limited manner in which the two separately 
analyzed systems (LFAS and MFAS) may interact in a multi-strike group 
exercise in the MIRC.

Exercises Utilizing MFAS in the MIRC

    As described above, ASW Exercises are the primary type of exercises 
that utilize MFAS and HFAS sources in the MIRC. Unit level tracking and 
torpedo ASW exercises occur regularly in the MIRC. Additionally, in a 
single year the MIRC will either have several major exercises, or one 
multi-strike group exercise, that integrate ASW training with other 
types of training such as air, surface, or strike warfare. ASW exercise 
descriptions are included below and summarized (along with the 
exercises utilizing explosives) in Table 2.
    ASW Tracking Exercise (TRACKEX)--Generally, TRACKEXs train 
aircraft, ship, and submarine crews in tactics, techniques, and 
procedures for search, detection, localization, and tracking of 
submarines with the goal of determining a firing solution that could be 
used to launch a torpedo and destroy the submarine. ASW Tracking 
Exercises occur during both day and night. A typical unit-level 
exercise involves one (1) ASW unit (aircraft, ship, or submarine) 
versus one (1) target--either a MK-39 Expendable Mobile ASW Training 
Target (EMATT), or a live submarine. The target may be non-evading 
while operating on a specified track or fully evasive. Participating 
units use active and passive sensors, including hull-mounted sonar, 
towed arrays, and sonobuoys for tracking. If

[[Page 53803]]

the exercise continues into the firing of a practice torpedo it is 
termed a Torpedo Exercise (TORPEX). The ASW TORPEX usually starts as a 
TRACKEX to achieve the firing solution. The different types of TORPEXs 
are further described below.
    Torpedo Exercise (TORPEX)--Anti-submarine Warfare (ASW) TORPEX 
activities train crews in tracking and attack of submerged targets, 
firing one or two exercise torpedoes (EXTORPs) or recoverable exercise 
torpedoes (REXTORPs). TORPEX targets and systems used in the Offshore 
Areas may include live submarines, MK-46, MK-54, and MK-48 torpedoes, 
MK-30 ASW training targets, and MK-39 Expendable Mobile ASW Training 
Targets (EMATTs). The target may be non-evading while operating on a 
specified track, or it may be fully evasive, depending on the training 
requirements of the training exercise. Submarines periodically conduct 
torpedo firing training exercises within the MIRC. Typical duration of 
a submarine TORPEX exercise is 10 hours, while air and surface ASW 
platform TORPEX exercises using the MK-46 and MK-54 torpedoes are 
considerably shorter.
    Joint Expeditionary Exercise--The Joint Expeditionary Exercise 
brings different branches of the U.S. military together in a joint 
environment that includes planning and execution efforts as well as 
military operations at sea, in the air, and ashore. The purpose of the 
exercise is to train a U.S. Joint Task Force staff in crisis action 
planning for execution of contingency operations. It provides U.S. 
forces an opportunity to practice training together in a joint 
environment as well as a combined environment with partner nation 
forces, where more than 8,000 personnel may participate.
    The participants and assets could include: Carrier Strike Group 
with its aircraft carrier, guided missile cruisers and Guided missile 
destroyers; Amphibious command and assault ships, submarines, logistic 
ships. It may also include Fleet and Battle Group Staffs, Naval and Air 
Force aircraft, Marine Expeditionary Units (MEU), and Army Infantry 
Units. This type of exercise would include activities conducted at sea 
and in the air and near-shore and ashore activities on Tinian, FDM, 
Guam, and Saipan.
    ASW active sonar activity may include: Single and multi-unit 
TRACKEX and TORPEX in coordinated ASW events; active ASW sources may 
include SQS-53; SQS-56; DICASS; IEER/AEER; AQS-22; BQQ-10; MK-48 
EXTORP; and, Portable Underwater Tracking Range operation including 
transponders and MK-84 range tracking pingers.
    Marine Air Ground Task Force (Amphibious) (MAGTF) Exercise--This 
major exercise includes over the horizon, ship to objective maneuver 
and activities of the ESG and Amphibious MAGTF for up to 10 days. The 
exercise utilizes all elements of the MAGTF to secure the battlespace 
(air, land, and sea), maneuver to and seize the objective, and conduct 
self-sustaining operations ashore with continual logistic support of 
the ESG. Tinian is the primary MIRC training area for this exercise; 
however elements of the exercise may be rehearsed nearshore and on 
Guam.
    ASW active sonar activity may include: single and multi-unit 
TRACKEX and TORPEX in coordinated ASW event; active ASW sources may 
include SQS-53C/D; SQS-56; DICASS; IEER/AEER; AQS-22; BQQ-10; MK-48 
EXTORP and Portable Underwater Tracking Range operation including 
transponders and MK-84 range tracking pingers.
    Joint Multi-Strike Group Exercise--The Joint Multi-Strike Group 
conducts training involving Navy assets engaging in a schedule of 
events (SOE) battle scenario, with U.S. forces pitted against a 
notional opposition force (OPFOR). Participants use and build upon 
previously gained training skill sets to maintain and improve the 
proficiency needed for a mission-capable, deployment-ready unit.
    The exercise includes several at-sea activities. In Command and 
Control (C2), a command organization exercises operational control of 
the assets involved in the exercise. This control includes monitoring 
for safety and compliance with protective measures. Air Warfare (AW) 
includes missile exercises which involve firing live missiles at air 
targets. Ships and aircraft fire missiles against air targets. AW also 
includes non-firing events such as Defensive Counter Air (DCA). DCA 
exercises ship and aircrew capabilities at detecting and reacting to 
incoming airborne threats. In Anti-Surface Warfare (ASUW), Naval forces 
control sea lanes by countering hostile surface combatant ships.
    ASW active sonar activity in this exercise may include: Single and 
multi-unit TRACKEX and TORPEX in coordinated ASW events; active ASW 
sources may include SQS-53C/D; SQS-56; DICASS; IEER/AEER; AQS-22; BQQ-
10; MK-48 EXTORP; Portable Underwater Tracking Range operation 
including transponders and MK-84 range tracking pingers.
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[[Page 53805]]

Activities Utilizing Underwater Detonations

    Underwater detonation activities can occur at various depths 
depending on the activity, but may also include activities with 
detonations at or just below the surface (such as SINKEX or gunnery 
exercise [GUNEX]). When the weapons hit the target, except for live 
torpedo shots, there is no explosion in the water, and so a ``hit'' is 
not modeled (i.e., the energy (either acoustic or pressure) from the 
hit is not expected to reach levels that would result in take of marine 
mammals). When a live weapon misses, it is modeled as exploding below 
the water surface at 1 ft (5-inch naval gunfire, 76-mm rounds), 2 
meters (Maverick, Harpoon, MK-82, MK-83, MK-84), or 50 ft (MK-48 
torpedo) as shown in Appendix A of the Navy's application (the depth is 
chosen to represent the worst case of the possible scenarios as related 
to potential marine mammals impacts). Exercises may utilize either live 
or inert ordnance of the types listed in Table 3. Additionally, 
successful hit rates are known to the Navy and are utilized in the 
effects modeling. Training events that involve explosives and 
underwater detonations occur throughout the year and are described 
below and summarized in Table 2.
[GRAPHIC] [TIFF OMITTED] TP20OC09.002

    Sinking Exercise--In a SINKEX, a specially prepared, deactivated 
vessel is deliberately sunk using multiple weapons systems. The 
exercise provides training to ship and aircraft crews in delivering 
both live and inert ordnance on a real target. These target vessels are 
empty, cleaned, and environmentally-remediated ship hulk. A SINKEX 
target is towed to sea and set adrift at the SINKEX location. The 
duration of a SINKEX is unpredictable since it ends when the target 
sinks, sometimes immediately after the first weapon impact and 
sometimes only after multiple impacts by a variety of weapons. 
Typically, the exercise lasts for 4 to 8 hours over 1 to 2 days. 
SINKEXs occur only occasionally during MIRC exercises. Potential 
harassment would be from underwater detonation. SINKEX events have been 
conducted in the open ocean of the western Pacific and within the MIRC, 
in compliance with 40 CFR 229.2.
    The Environmental Protection Agency (EPA) grants the Navy a general 
permit through the Marine Protection, Research, and Sanctuaries Act to 
transport vessels ``for the purpose of sinking such vessels in ocean 
waters[hellip]'' (40 CFR 229.2). Subparagraph (a)(3) of this regulation 
states ``All such vessel sinkings shall be conducted in water at least 
1,000 fathoms (6,000 feet) deep and at least 50 nautical miles from 
land.''
    SINKEX events typically include at least one surface combatant 
(frigate, destroyer, or cruiser); one submarine; and numerous fixed-
wing and rotary-wing aircraft. One surface ship will serve as a 
surveillance platform to ensure the hulk does not pose a hazard to 
navigation prior to and during the SINKEX. The weapons actually 
expended during a SINKEX can vary greatly. Table 1-2 in the Navy's 
application indicates the typical ordnance used in a SINKEX, which 
include HARPOON, HELLFIRE, and MAVERICK missiles, 5' gunfire, MK-48 
torpedoes, and underwater demolitions. This table reflects the planning 
for weapons, which may be expended during one SINKEX in the MIRC Study 
Area. This level of ordnance is expected for each of the SINKEX events 
in the Joint Multi-strike Group exercise. With the exception of the 
torpedo, which is designed to explode below the target hulk in the 
water column, the weapons deployed during a SINKEX are intended to 
strike the target hulk, and thus not explode within the water column.
    Surface-to-Surface Gunnery Exercise--S-S GUNEX take place in the 
open ocean to provide gunnery practice for Navy and Coast Guard ship 
crews. GUNEX training activities conducted in the offshore study area 
involve stationary targets such as a MK-42 floating at-sea target 
(FAST) or a MK-58 marker (smoke) buoy. The gun systems employed against 
surface targets include the 5-inch, 76 millimeter (mm), 25-mm chain 
gun, 20-mm Close-in Weapon System (CIWS), and 50-caliber machine gun. 
Typical ordnance expenditure for a single GUNEX is a minimum of 21 
rounds of 5-inch or 76-mm ammunition, and approximately 150 rounds of 
25-mm or .50-caliber ammunition. Both live and inert training rounds 
are used. After impacting the water, the rounds and fragments sink to 
the bottom of the ocean. A GUNEX lasts approximately 1 to 2 hours, 
depending on target services and weather conditions. The live 5-inch 
and 76-mm rounds are considered in the underwater detonation modeling.
    Air-to-Surface Gunnery Exercise (A-S GUNEX)--A-S GUNEX training 
activities are conducted by rotary-wing aircraft against stationary 
targets (Floating at-sea Target [FAST] and smoke buoy). Rotary-wing 
aircraft involved in this activity would include a single helicopter 
using either 7.62-mm or .50-caliber door-mounted machine guns. A 
typical GUNEX will last approximately one hour and involve the

[[Page 53806]]

expenditure of approximately 400 rounds of 0.50-caliber or 7.62-mm 
ammunition. Due to their being inert and the small size of the rounds, 
they are not considered to have an underwater detonation impact.
    Air-to-Surface Missile Exercise (A-S MISSILEX)--The A-S MISSILEX 
consists of the attacking platform releasing a forward-fired, guided 
weapon at the designated towed target. The exercise involves locating 
the target, then designating the target, usually with a laser. A-S 
MISSILEX training that does not involve the release of a live weapon 
can take place if the attacking platform is carrying a captive air 
training missile (CATM) simulating the weapon involved in the training. 
The CATM MISSILEX is identical to a live-fire exercise in every aspect 
except that a weapon is not released. The training requires a laser-
safe range as the target is designated just as in a live-fire exercise. 
From 1 to 16 aircraft, carrying live, inert, or CATMs, or flying 
without ordnance (dry runs) are used during the exercise. At sea, 
seaborne powered targets (SEPTARs), Improved Surface Towed Targets 
(ISTTs), and decommissioned hulks are used as targets. A-S MISSILEX 
assets include helicopters and/or 1 to 16 fixed-wing aircraft with air-
to-surface missiles and anti-radiation missiles (electromagnetic 
radiation source seeking missiles). Targets include SEPTARs, ISTTs, and 
excess ship hulks. When HELLFIRE Missiles are used the exercise is 
called a HELLFIRE MISSILEX. HELLFIRE MISSILEXs would occur 2 times per 
year in an area approximately 30-35 nm south of Apra Harbor in W-517. 
Potential harassment would be from underwater detonation.
    Surface-to-Surface Missile Exercise (S-S MISSILEX)--S-S MISSILEX 
involves the attack of surface targets at sea by use of cruise missiles 
or other missile systems, usually by a single ship conducting training 
in the detection, classification, tracking and engagement of a surface 
target. S-S MISSILEXs always occur during a SINKEX. Engagement is 
usually with HARPOON missiles or Standard missiles in the surface-to-
surface mode. Targets could include virtual targets or the SEPTAR or 
ship deployed surface target. S-S MISSILEX training is routinely 
conducted on individual ships with embedded training devices. A S-S 
MISSILEX could include 4 to 20 surface-to-surface missiles, SEPTARs, a 
weapons recovery boat, and a helicopter for environmental and photo 
evaluation. All missiles are equipped with instrumentation packages or 
a warhead. Surface-to-air missiles can also be used in a surface-to-
surface mode. Each exercise typically lasts five hours. Future S-S 
MISSILEX could range from 4 to 35 hours. Potential harassment would be 
from underwater detonation.
    Air-to-Surface Bombing Exercise--During an Air-to-Surface Bombing 
Exercise (BOMBEX A-S), fixed-wing aircraft deliver bombs against 
simulated surface maritime targets, typically a smoke float, with the 
goal of destroying or disabling enemy ships or boats. Typically, a 
flight of two aircraft will approach the target from an altitude of 
between 15,000 ft to less than 3,000 ft, and will adhere to designated 
ingress and egress routes. Typical bomb release altitude is below 3,000 
ft and within a range of 1000 yards for unguided munitions, and above 
15,000 ft and in excess of 10 nm for precision-guided munitions. In 
most training exercises, the aircrew drops inert training ordnance, 
such as the Bomb Dummy Unit (BDU-45) on a MK-58 smoke float used as the 
target. Some BOMBEXs include the use of the MK-84/GBU-31 JDAM, the 
largest bomb proposed for use. JDAM training would occur 4 times per 
year in W-517 and generally in the southern portion avoiding known 
fishing areas. The surface danger zone requires a 25 nm buffer around 
the aim point, so that all operations occur within W-517. Each BOMBEX 
A-S can take up to 4 hours to complete.
    Mine Neutralization--Mine Neutralization involves the detection, 
identification, evaluation, rendering safe, and disposal of mines and 
unexploded ordnance (UXO) that constitutes a threat to ships or 
personnel. Mine neutralization training can be conducted by a variety 
of air, surface and undersea assets. Potential harassment would be from 
underwater detonation.
    Tactics for neutralization of ground or bottom mines involve the 
diver placing a specific amount of explosives, which when detonated 
underwater at a specific distance from a mine results in neutralization 
of the mine. Floating, or moored, mines involve the diver placing a 
specific amount of explosives directly on the mine. Floating mines 
encountered by Fleet ships in open-ocean areas are detonated at the 
surface. In support of an expeditionary assault, divers and Navy marine 
mammal assets deploy in very shallow water depths (10 to 40 feet) to 
locate mines and obstructions. Divers are transported to the mines by 
boat or helicopter. Inert dummy mines are used in the exercises. The 
total net explosive weight used against each mine ranges from less than 
1 pound to 20 pounds.
    All demolition activities are conducted in accordance with 
Commander, Naval Surface Forces Pacific (COMNAVSURFPAC) Instruction 
3120.8F, Procedures for Disposal of Explosives at Sea/Firing of Depth 
Charges and Other Underwater Ordnance (DoN 2003). Before any explosive 
is detonated, divers are transported a safe distance away from the 
explosive. Standard practices for tethered mines require ground mine 
explosive charges to be suspended 10 feet below the surface of the 
water.
    EER-IEER AN/SSQ-110A--The Extended Echo Ranging and Improved 
Extended Echo Ranging (EER/IEER) Systems are airborne ASW systems used 
in conducting ``large area'' searches for submarines. These systems are 
made up of airborne avionics ASW acoustic processing and sonobuoy types 
that are deployed in pairs. The IEER System's active sonobuoy 
component, the AN/SSQ-110A Sonobuoy, generates a sound similar to a 
``sonar ping'' using a small explosive and the passive AN/SSQ-101A ADAR 
Sonobuoy ``listens'' for the return echo of the ``sonar ping'' that has 
been bounced off the surface of a submarine. These sonobuoys are 
designed to provide underwater acoustic data necessary for naval 
aircrews to quickly and accurately detect submerged submarines. The 
sonobuoy pairs are dropped from a fixed-wing aircraft into the ocean in 
a predetermined pattern with a few buoys covering a very large area. 
The AN/SSQ-110A Sonobuoy Series is an expendable and commandable 
sonobuoy. Upon command from the aircraft, the bottom payload is 
released to sink to a designated operating depth. A second command is 
required from the aircraft to cause the second payload to release and 
detonate the explosive to generate a ``ping''. There is only one 
detonation in the pattern of buoys at a time. Potential harassment 
would be from underwater detonations.
    The AEER system (described in the sonar source section) will 
eventually replace use of the EER/IEER system and was analyzed for this 
proposed rule.

Vessel Movement

    The operation and movement of vessels that is necessary to conduct 
the training described above is also analyzed here. Training exercises 
involving vessel movements occur intermittently and are variable in 
duration, ranging from a few hours up to 10 days. During training, 
speeds vary and depend on the specific type of activity, although 10-14 
knots is considered the typical speed. The Navy logs about 1,000 total 
vessel days within

[[Page 53807]]

the MIRC Study Area during a typical year. Training activities are 
widely dispersed throughout the large OPAREA, which encompasses 501,873 
nm\2\ (1,299,851 km\2\). Consequently, the density of Navy ships within 
the Study Area at any given time is low.

Research, Development, Testing, and Evaluation

    The Services may conduct RDT&E, engineering, and fleet support for 
command, control, and communications systems and ocean surveillance in 
the MIRC. These activities may include ocean engineering, missile 
firings, torpedo testing, manned and unmanned submersibles testing, 
unmanned aerial vehicle (UAV) tests, electronic combat (EC), and other 
DoD weapons testing.
    RDT&E activities, if they have a potential for takes of marine 
mammals, will be reviewed to assure they are included within the 
parameters of existing sonar and explosive activities as modeled for 
this rule and the LOAs. As an example, if a new model of SQS 53 sonar 
were tested, as long as it's operating parameters are within the 
parameters modeled, an equal number of hours of SQS 53C use in training 
would be deducted to ensure that the total SQS 53C hours for the year 
(training plus RDT&E) remain within those described in the rule. The 
same would apply for explosives, overall NET explosive weights for 
similar munitions would be reviewed to assure compliance with existing 
rules.
    Additional information on the Navy's proposed activities may be 
found in the LOA Application and the Navy's MIRC DEIS.

Description of Marine Mammals in the Area of the Specified Activities

    Thirty-two marine mammal species or populations/stocks have 
confirmed or possible occurrence within the MIRC, including seven 
species of baleen whales (mysticetes), 22 species of toothed whales 
(odontocetes), two species of seal (pinnipeds), and the dugong 
(sirenian). Table 4 summarizes their abundance, Endangered Species Act 
(ESA) status, occurrence, and density in the area. Seven of the species 
are ESA-listed and considered depleted under the MMPA: Blue whale; fin 
whale; humpback whale; sei whale; sperm whale; North Pacific right 
whale; Hawaiian monk seal; and dugong. The dugong is managed by the 
U.S. Fish and Wildlife Service and will not be addressed further here.
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Species Not Considered Further

    North Pacific right whale--The likelihood of a North Pacific right 
whale (Eubalaena japonica) occurring in the action area is extremely 
low. The North Pacific right whale population is the most endangered of 
the large whale species (Perry et al., 1999) and, currently, there is 
no reliable population estimate for this species, although the 
population in the western North Pacific Ocean is considered to be very 
small, perhaps in the tens to low hundreds of animals. Despite many 
years of systematic aerial and ship-based surveys for marine mammals 
off the western coast of the U.S., only seven documented sightings of 
right whales were made from 1990 through 2005 near Alaska (Waite et 
al., 2003; Wade et al., 2006). Based on this information, it is highly 
unlikely for a right whale to be present in the action area. 
Consequently, this species will not be considered in the remainder of 
this analysis.
    Hawaiian monk seal--The likelihood of a Hawaiian monk seal 
(Monachus schauinslandi) being present in the action area is extremely 
low. There are no confirmed records of Hawaiian monk seals in the 
Micronesia region; however, Reeves et al. (1999) and Eldredge (1991, 
2003) have noted occurrence records for

[[Page 53809]]

seals (unidentified species) in the Marshall and Gilbert islands. It is 
possible that Hawaiian monk seals wander from the Hawaiian Islands to 
appear at the Marshall or Gilbert Islands in the Micronesia region 
(Eldredge 1991). However, given the extremely low likelihood of this 
species occurrence in the action area, the Hawaiian monk seal will not 
be considered in the remainder of this analysis.
    Hubbs Beaked Whale--The likelihood of a Hubbs beaked whale 
(Mesoplodon carlhubbsi) occurring in the action area is extremely low. 
There are no occurrence records for the Mariana Islands and the nearest 
records are from strandings in Japan (DoN 2005). Recent data suggests 
that the distribution is likely north of 30[deg] N (MacCleod et al., 
2006). Given the extremely low likelihood of this species occurrence in 
the action area, the Hubbs beaked whale will not be considered in the 
remainder of this analysis.
    Indo-Pacific Bottlenose Dolphin--The likelihood of an Indo-Pacific 
bottlenose dolphin (Tursiops aduncas) occurring in the action area is 
extremely low. The Indo-Pacific bottlenose dolphin is generally 
associated with continental margins and does not appear to occur around 
offshore islands that are great distances from a continent, such as the 
Marianas (Jefferson as cited in DoN 2005). Given the extremely low 
likelihood of this species occurrence in the action area, the Indo-
Pacific bottlenose dolphin will not be considered in the remainder of 
this analysis.
    Northern Elephant Seal--Northern elephant seals (Mirounga 
angustirostris) are common on islands and mainland haul-out sites in 
Baja California, Mexico north through central California. Elephant 
seals spend several months at sea feeding and travel as far as the Gulf 
of Alaska. Occasionally juveniles wander great distances with several 
individuals being observed in Hawaii and Japan. Although elephant seals 
may wander great distances it is very unlikely that they would travel 
to Japan or Hawaii and then continue traveling to the MIRC. Given the 
extremely low likelihood of this species occurrence in the action area, 
the northern elephant seal will not be considered in the remainder of 
this analysis.
    The Navy has compiled information on the abundance, behavior, 
status and distribution, and vocalizations of marine mammal species in 
the MIRC waters from the Navy Marine Resource Assessment and has 
supplemented this information with additional citations derived from 
new survey efforts and scientific publications. NMFS has not designated 
stocks of marine mammals in the waters surrounding the MIRC and, 
therefore, does not compile stock assessment reports for this area. 
This information may be viewed in the Navy's LOA application and/or the 
Navy's DEIS for MIRC (see Availability), and is incorporated by 
reference herein.
    There are no designated marine mammal critical habitats or known 
breeding areas within the MIRC. Much is unknown about the reproductive 
habits of the dolphin species in MIRC, but they are thought to mate 
throughout their range (like better studied species and stocks are 
known to do) and possibly throughout the year. Even less is known about 
the mating habits of beaked whales. Baleen whales and sperm whales are 
thought to breed seasonally in areas within and around the MIRC and 
some calves have been seen with sperm, Bryde's and sei whales (DoN 
2007b), although it is not known where exactly breeding and calving 
occurs.
    Spinner dolphins, which rest primarily during the day in relatively 
large groups, are known to consistently use certain areas (usually 
bays) for this function. Because of this, they are regularly visited by 
whalewatching boats or other members of the public interested in 
viewing or interacting with them, which could potentially put them at 
increased energetic risk if their resting cycles are repeatedly 
interrupted in a significant manner. There are several recognized 
resting areas for spinner dolphins in the MIRC Study Area: Agat Bay, 
Bile/Tougan Bay, and Double Reef. These areas are in clear, calm, 
shallow waters sheltered from prevailing tradewinds.

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 in the 
sea. 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). 
Baleen whales have inner ears that appear to be specialized for low-
frequency hearing. Conversely, dolphins and porpoises have ears that 
are specialized to hear high frequencies.
    Marine mammal vocalizations often extend both above and below the 
range of human hearing; vocalizations with frequencies lower than 18 
Hertz (Hz) are labeled as infrasonic and those higher than 20 kHz as 
ultrasonic (National Research Council [NRC], 2003; Figure 4-1). 
Measured data on the hearing abilities of cetaceans are sparse, 
particularly for the larger cetaceans such as the baleen whales. The 
auditory thresholds of some of the smaller odontocetes have been 
determined in captivity. It is generally believed that cetaceans should 
at least be sensitive to the frequencies of their own vocalizations. 
Comparisons of the anatomy of cetacean inner ears and models of the 
structural properties and the response to vibrations of the ear's 
components in different species provide an indication of likely 
sensitivity to various sound frequencies. The ears of small toothed 
whales are optimized for receiving high-frequency sound, while baleen 
whale inner ears are best in low to infrasonic frequencies (Ketten, 
1992; 1997; 1998).
    Baleen whale vocalizations are composed primarily of frequencies 
below 1 kHz, and some contain fundamental frequencies as low as 16 Hz 
(Watkins et al., 1987; Richardson et al., 1995; Rivers, 1997; Moore et 
al., 1998; Stafford et al., 1999; Wartzok and Ketten, 1999) but can be 
as high as 24 kHz (humpback whale; Au et al., 2006). Clark and Ellison 
(2004) suggested that baleen whales use low frequency sounds not only 
for long-range communication, but also as a simple form of echo 
ranging, using echoes to navigate and orient relative to physical 
features of the ocean. Information on auditory function in mysticetes 
is extremely lacking. Sensitivity to low-frequency sound by baleen 
whales has been inferred from observed vocalization frequencies, 
observed reactions to playback of sounds, and anatomical analyses of 
the auditory system. Although there is apparently much variation, the 
source levels of most baleen whale vocalizations lie in the range of 
150-190 dB re 1 [mu]Pa at 1

[[Page 53810]]

m. Low-frequency vocalizations made by baleen whales and their 
corresponding auditory anatomy suggest that they have good low-
frequency hearing (Ketten, 2000), although specific data on 
sensitivity, frequency or intensity discrimination, or localization 
abilities are lacking. Marine mammals, like all mammals, have typical 
U-shaped audiograms that begin with relatively low sensitivity (high 
threshold) at some specified low frequency with increased sensitivity 
(low threshold) to a species specific optimum followed by a generally 
steep rise at higher frequencies (high threshold) (Fay, 1988).
    The toothed whales produce a wide variety of sounds, which include 
species-specific broadband ``clicks'' with peak energy between 10 and 
200 kHz, individually variable ``burst pulse'' click trains, and 
constant frequency or frequency-modulated (FM) whistles ranging from 4 
to 16 kHz (Wartzok and Ketten, 1999). The general consensus is that the 
tonal vocalizations (whistles) produced by toothed whales play an 
important role in maintaining contact between dispersed individuals, 
while broadband clicks are used during echolocation (Wartzok and 
Ketten, 1999). Burst pulses have also been strongly implicated in 
communication, with some scientists suggesting that they play an 
important role in agonistic encounters (McCowan and Reiss, 1995), while 
others have proposed that they represent ``emotive'' signals in a 
broader sense, possibly representing graded communication signals 
(Herzing, 1996). Sperm whales, however, are known to produce only 
clicks, which are used for both communication and echolocation 
(Whitehead, 2003). Most of the energy of toothed whales social 
vocalizations is concentrated near 10 kHz, with source levels for 
whistles as high as 100-180 dB re 1 [mu]Pa at 1 m (Richardson et al., 
1995). No odontocete has been shown audiometrically to have acute 
hearing (<80 dB re 1 [mu]Pa) below 500 Hz (DoN, 2001). Sperm whales 
produce clicks, which may be used to echolocate (Mullins et al., 1988), 
with a frequency range from less than 100 Hz to 30 kHz and source 
levels up to 230 dB re 1 [mu]Pa 1 m or greater (Mohl et al., 2000).
    Table 5 includes a summary of the vocalizations of the species 
found in the MIRC. The ``Brief Background on Sound'' section below 
contains a description of the functional hearing groups designated by 
Southall et al. (2007), which includes the functional hearing range of 
various marine mammal groups (i.e., what frequencies that can actually 
hear).
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Marine Mammal Density Estimates

    Understanding the distribution and abundance of a particular marine 
mammal species or stock is necessary to analyze the potential impacts 
of an action on that species or stock. Further, it is necessary to know 
the density of the animals in the affected area in order to 
quantitatively assess the likely acoustic impacts of a potential action 
on individuals and estimate take (discussed further in the Estimated 
Take section).
    Prior to 2007 there was little information available on the 
abundance and density of marine mammals in the MIRC Study Area. Most 
information on the occurrence of marine mammals came from short surveys 
(several days) and opportunistic sightings (NMFS Platform of 
Opportunity, oceanographic cruises or strandings). The first 
comprehensive survey of the area, Mariana Islands Sea Turtle and 
Cetacean Survey (MISTCS), was funded by the Navy to gather data in 
support of this analysis and was conducted in early 2007 covering mid 
January to mid April (DoN 2007b). Densities were calculated for 13 
species observed during this survey and are the only published 
densities derived for this area that are based upon actual sightings. 
For the purposes of the MIRC analysis, the Navy compiled published 
densities from other geographical areas with existing survey data and 
similar oceanography (e.g. sea surface temperature) such as the 
Hawaiian Islands (Barlow 2003, 2006), warm water areas of the eastern 
tropical Pacific (Ferguson and Barlow 2001, 2003) and Miyashita (1993). 
As shown in Table 3-2 of the MIRC application, for the species that 
MISTCS provided an estimate for, the estimated densities are either 
mid-range or higher than the other published densities. This, combined 
with the fact that the MISTCS survey was conducted in the actual MIRC 
Study Area, supports the Navy's decision to use MISTCS data as the 
primary source for modeling. Considering the similar habitat and 
species diversity with the MIRC Study Area, offshore survey data from 
the Hawaiian Islands (Barlow 2003, 2006) was used as a secondary 
source. Densities from the Eastern Tropical Pacific survey (Ferguson 
and Barlow 2001, 2003) were used for six remaining species. Miyashita 
1993 was also reviewed; however, no densities from that report were 
ultimately utilized because the surveys were not conducted in the 
systematic line transect manner typically used by NMFS, but rather 
occurred while searching for cetaceans.
    The draft MISTCS density report was reviewed by local biologists at 
NMFS-Pacific Fisheries Science Center (PIFSC) and Pacific Islands 
Regional Office (PIRO), whose recommendations were incorporated into 
the final document. The methods used in the final MISTCS report was 
approved by NMFS PIFSC and PIRO for use in preparation of environmental 
planning documents for the Mariana Islands.

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 
(for the MFAS/HFAS considered in this proposed rule, the medium is 
marine 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, it is derived from ratios of pressures; the 
standard reference pressure for underwater sound is 1 microPascal 
([mu]Pa); for airborne sound, the standard reference pressure is 20 
[mu]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 [mu]Pa or, for airborne sound, 20 
[mu]Pa). The logarithmic nature of the scale means that each 10 dB 
increase is a ten-fold increase in power (e.g., 20 dB is a 100-fold 
increase over 10 dB, 30 dB is a 1,000-fold increase over 10dB). Humans 
perceive a 10-dB increase in noise as a doubling of loudness, or a 10 
dB decrease in noise 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[mu]Pa) as a standard reference 
pressure unless noted otherwise.
    It is important to note that decibels underwater and decibels in 
air are not the same and cannot be directly compared. To estimate a 
comparison between sound in air and underwater, because of the 
different densities of air and water and the different decibel 
standards (i.e., reference pressures) in water and air, a sound with 
the same intensity (i.e., power) in air and in water would be 
approximately 63 dB quieter in air. Thus a sound that is 160 dB loud 
underwater would have the same approximate effective intensity as a 
sound that is 97 dB loud in air.
    Sound frequency is measured in cycles per second, or Hertz 
(abbreviated Hz), and is analogous to musical pitch; high-pitched 
sounds contain high frequencies and low-pitched sounds contain low 
frequencies. Natural sounds in the ocean span a huge range of 
frequencies: from earthquake noise at 5 Hz to harbor porpoise clicks at 
150,000 Hz (150 kHz). These sounds are so low or so high in pitch that 
humans cannot even hear them; acousticians call these infrasonic 
(typically below 20 Hz) and ultrasonic (typically above 20,000 Hz) 
sounds, respectively. A single sound may be made up of many different 
frequencies together. Sounds made up of only a small range of 
frequencies are called ``narrowband'', and sounds with a broad range of 
frequencies are called ``broadband''; explosives are an example of a 
broadband sound source and active tactical sonars are an example of a 
narrowband sound source.
    When considering the influence of various kinds of sound on the 
marine environment, it is necessary to understand that different kinds 
of marine life are sensitive to different frequencies of sound. Based 
on available behavioral data, audiograms derived using 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 group. The functional groups and the 
associated frequencies are indicated below (though, again, animals are 
less sensitive to sounds at the outer edge of their functional range 
and most sensitive to sounds of frequencies within a smaller range 
somewhere in the middle of their functional hearing range):
    <bullet> Low frequency cetaceans (13 species of mysticetes): 
functional hearing is estimated to occur between approximately 7 Hz and 
22 kHz;
    <bullet> Mid-frequency cetaceans (32 species of dolphins, six 
species of larger toothed whales, and 19 species of beaked and 
bottlenose whales): functional hearing is estimated to occur

[[Page 53814]]

between approximately 150 Hz and 160 kHz;
    <bullet> High frequency cetaceans (eight species of true porpoises, 
six species of river dolphins, Kogia, the franciscana, and four species 
of cephalorhynchids): functional hearing is estimated to occur between 
approximately 200 Hz and 180 kHz;
    <bullet> Pinnipeds in Water: functional hearing is estimated to 
occur between approximately 75 Hz and 75 kHz, with the greatest 
sensitivity between approximately 700 Hz and 20 kHz.
    Because ears adapted to function underwater are physiologically 
different from human ears, comparisons using decibel measurements in 
air would still not be adequate to describe the effects of a sound on a 
whale. When sound travels (propagates) away from its source, its 
loudness decreases as the distance traveled by the sound increases. 
Thus, the loudness of a sound at its source is higher than the loudness 
of that same sound a kilometer distant. Acousticians often refer to the 
loudness of a sound at its source (typically measured one meter from 
the source) as the source level and the loudness of sound elsewhere as 
the received level. For example, a humpback whale three kilometers from 
an airgun that has a source level of 230 dB may only be exposed to 
sound that is 160 dB loud, depending on how the sound propagates (in 
this example, it is spherical spreading). As a result, it is important 
not to confuse 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 MFAS/HFAS operations, crews will measure 
oceanic conditions, such as sea water temperature and depth, to 
calibrate models that determine the path the sonar signal will take as 
it travels through the ocean and how strong the sound signal will be at 
a given range along a particular transmission path). As sound travels 
through the ocean, the intensity associated with the wavefront 
diminishes, or attenuates. This decrease in intensity is referred to as 
propagation loss, also commonly called transmission loss.

Metrics Used in This Document

    This section includes a brief explanation of the two sound 
measurements (sound pressure level (SPL) and sound exposure level 
(SEL)) frequently used in the discussions of acoustic effects in this 
document.

SPL

    Sound pressure is the sound force per unit area, and is usually 
measured in micropascals ([mu]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. The commonly used reference pressure level in 
underwater acoustics is 1 [mu]Pa, and the units for SPLs are dB re: 1 
[mu]Pa.

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

    SPL is an instantaneous measurement and can be expressed as the 
peak, the peak-peak, or the root mean square (rms). Root mean square, 
which is the square root of the arithmetic average of the squared 
instantaneous pressure values, is typically used in discussions of the 
effects of sounds on vertebrates and all references to SPL in this 
document refer to the root mean square. SPL does not take the duration 
of a sound 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).

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 [mu]Pa\2\-s.

SEL = SPL + 10log(duration in seconds)

    As applied to MFAS/HFAS, the SEL includes both the SPL of a sonar 
ping and the total duration. Longer duration pings and/or pings with 
higher SPLs will have a higher SEL. If an animal is exposed to multiple 
pings, the SEL in each individual ping is summed to calculate the total 
SEL. The total 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 in 
SEL.

Potential Effects of Specified Activities on Marine Mammals

    The Navy has requested authorization for the take of marine mammals 
that may occur incidental to training and RDT&E activities in the MIRC 
utilizing MFAS/HFAS or underwater detonations. In addition to MFAS/HFAS 
and underwater detonations, the Navy has analyzed other potential 
impacts to marine mammals from training activities in the MIRC DEIS, 
including ship strike, aerial overflights, ship noise and movement, and 
others, and, in consultation with NMFS as a cooperating agency for the 
MIRC DEIS, has determined that take of marine mammals incidental to 
these non-acoustic components of the MIRC is unlikely and, therefore, 
has not requested authorization for take of marine mammals that might 
occur incidental to these non-acoustic components. In this document, 
NMFS analyzes the potential effects on marine mammals from exposure to 
MFAS/HFAS and underwater detonations, but also includes some additional 
analysis of the potential impacts from vessel operations in the MIRC.
    For the purpose of MMPA authorizations, NMFS' effects assessments 
serve four primary purposes: (1) To help identify the permissible 
methods of taking, meaning: the nature of the take (e.g., resulting 
from anthropogenic noise vs. from ship strike, etc.); the regulatory 
level of take (i.e., mortality vs. Level A or Level B harassment); and, 
the amount of take; (2) to inform the prescription of means of 
effecting the least practicable adverse impact on such species or stock 
and its habitat (i.e., mitigation); (3) to support the determination of 
whether the specified activity will have a negligible impact on the 
affected species or stocks of marine mammals (based on the likelihood 
that the activity will adversely affect the species or stock through 
effects on annual rates of recruitment or survival); and (4) to 
determine whether the specified activity will have an unmitigable 
adverse impact on the availability of the species or stock(s) for 
subsistence uses (however, there are no subsistence communities that 
would be affected in the MIRC).
    More specifically, for activities involving sonar or underwater 
detonations, 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

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harassment), and social responses that would be classified as 
behavioral harassment or injury and/or would be likely to adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival. In this section, we will focus qualitatively 
on the different ways that MFAS/HFAS and underwater explosive 
detonations may affect marine mammals (some of which NMFS would not 
classify as harassment). Then, in the Estimated Take of Marine Mammals 
Section, NMFS will relate the potential effects to marine mammals from 
MFAS/HFAS and underwater detonation of explosives to the MMPA 
regulatory definitions of Level A and Level B Harassment and attempt to 
quantify those effects.

Exposure to MFAS/HFAS

    In the subsections below, the following types of impacts are 
discussed in more detail: direct physiological impacts, stress 
responses, acoustic masking and impaired communication, behavioral 
disturbance, and strandings. An additional useful graphic tool for 
better understanding the layered nature of potential marine mammal 
responses to anthropogenic sound is presented in Figure 1 of NMFS' 
August 13, 2009 biological opinion for SURTASS LFA (available at: 
http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications). That 
document presents a conceptual model of the potential responses of 
endangered and threatened species upon being exposed to active sonar 
and the pathways by which those responses might affect the fitness of 
individual animals that have been exposed, and the resulting impact on 
the individual animal's ability to reproduce or survive. Literature 
supporting the framework, with examples drawn from many taxa (both 
aquatic and terrestrial) was included in the ``Application of this 
Approach'' and ``Response Analyses'' sections of that document.

Direct Physiological Effects

    Based on the literature, there are two basic ways that MFAS/HFAS 
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 recognize them) following exposure to a 
sufficiently intense sound, 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 recovery), occurs 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 by only 6 dB or reduced by 30 dB). PTS is permanent 
(i.e., there is no recovery), but also occurs 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 TSs: 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 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. Human 
non-impulsive noise exposure guidelines are based on exposures of equal 
energy (the same SEL) producing equal amounts of hearing impairment 
regardless of how the sound energy is distributed in time (NIOSH 1998). 
Until recently, previous marine mammal TTS studies have also generally 
supported this equal energy relationship (Southall et al., 2007). Three 
newer studies, two by Mooney et al. (2009a, 2009b) on a single 
bottlenose dolphin either exposed to playbacks of Navy MFAS or octave-
band noise (4-8 kHz) and one by Kastak et al. (2007) on a single 
California sea lion exposed to airborne octave-band noise (centered at 
2.5 kHz), concluded that for all noise exposure situations the equal 
energy relationship may not be the best indicator to predict TTS onset 
levels. All three of these studies highlight the inherent complexity of 
predicting TTS onset in marine mammals, as well as the importance of 
considering exposure duration when assessing potential impacts. 
Generally, with sound exposures of equal energy, those that were 
quieter (lower sound pressure level [SPL]) with longer duration were 
found to induce TTS onset more than those of louder (higher SPL) and 
shorter duration (more similar to MFAS). For intermittent sounds, less 
TS will occur than from a continuous exposure with the same energy 
(some recovery will occur between intermittent exposures) (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, very prolonged exposure to sound 
strong enough to elicit TTS, or shorter-term exposure to sound levels 
well above the TTS threshold, can cause PTS, at least in terrestrial 
mammals (Kryter, 1985) (although in the case of MFAS/HFAS, animals are 
not expected to be exposed to levels high enough or durations long 
enough to result in PTS).
    PTS is considered auditory injury (Southall et al., 2007). 
Irreparable damage to the inner or outer cochlear hair cells may cause 
PTS, however, other mechanisms are also involved, such as exceeding the 
elastic limits of certain tissues and membranes in the middle and inner 
ears and resultant changes in the chemical composition of the inner ear 
fluids (Southall et al., 2007).
    Although the published body of scientific literature contains 
numerous theoretical studies and discussion papers on hearing 
impairments that can occur with exposure to a loud sound, only a few 
studies provide empirical information on the levels at which noise-
induced loss in hearing sensitivity occurs in nonhuman animals. For 
cetaceans, published data on the onset of TTS are limited to the 
captive bottlenose dolphin and beluga (Finneran et al., 2000, 2002b, 
2005a; Schlundt et al., 2000; Nachtigall et al., 2003, 2004). For 
pinnipeds in water, data are limited to Kastak et al.'s measurement of 
TTS in one harbor seal, one elephant seal, and one California sea lion.
    Marine mammal hearing plays a critical role in communication with 
conspecifics and in interpretation of environmental cues for purposes 
such as predator avoidance and prey capture. Depending on the degree 
(elevation of threshold in dB), duration (i.e., recovery time), and 
frequency range of TTS, and

[[Page 53816]]

the context in which it is experienced, TTS can have effects on marine 
mammals ranging from discountable to serious (similar to those 
discussed in auditory masking, below). For example, a marine mammal may 
be able to readily compensate for a brief, relatively small amount of 
TTS in a non-critical frequency range that takes place during a time 
when the animal is traveling through the open ocean, where ambient 
noise is lower and there are not as many competing sounds present. 
Alternatively, a larger amount and longer duration of TTS sustained 
during a time when communication is critical for successful mother/calf 
interactions could have more serious impacts if it were in the same 
frequency band as the necessary vocalizations and of a severity that it 
impeded communication. The fact that animals exposed to levels and 
durations of sound that would be expected to result in this 
physiological response would also be expected to have behavioral 
responses of a comparatively more severe or sustained nature is also 
notable and potentially of more importance than the simple existence of 
a TTS.
    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 than TTS because it is a permanent condition. Of 
note, reduced hearing sensitivity as a simple function of development 
and aging has been observed in marine mammals, as well as humans and 
other taxa (Southall et al., 2007), so we can infer that strategies 
exist for coping with this condition to some degree, though likely not 
without cost. There is no empirical evidence that exposure to MFAS/HFAS 
can cause PTS in any marine mammals; instead the probability of PTS has 
been inferred from studies of TTS (see Richardson et al., 1995).

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) although recent preliminary 
empirical data suggests that there is no increase in blood nitrogen 
levels or formation of bubbles in diving bottlenose dolphins (Houser 
2008). 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 MFAS pings would be long 
enough to drive bubble growth to any substantial size, if such a 
phenomenon occurs. However, an alternative but related hypothesis has 
also been suggested: stable bubbles could be destabilized by 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) speculated that 
rapid ascent to the surface following exposure to a startling sound 
might produce tissue gas saturation sufficient for the evolution of 
nitrogen bubbles (Jepson et al., 2003; Fernandez et al., 2005). In this 
scenario, the rate of ascent would need to be sufficiently rapid to 
compromise behavioral or physiological protections against nitrogen 
bubble formation. Alternatively, Tyack et al. (2006) studied the deep 
diving behavior of beaked whales and concluded that ``Using current 
models of breath-hold diving, we infer that their natural diving 
behavior is inconsistent with known problems of acute nitrogen 
supersaturation and embolism.'' Collectively, these hypotheses can be 
referred to as ``hypotheses of acoustically mediated bubble growth.''
    Although theoretical predictions suggest the possibility for 
acoustically mediated bubble growth, there is considerable disagreement 
among scientists as to its likelihood (Piantadosi and Thalmann, 2004; 
Evans and Miller, 2003; Cox et al., 2006; Rommel et al., 2006). Crum 
and Mao (1996) hypothesized that received levels would have to exceed 
190 dB in order for there to be the possibility of significant bubble 
growth due to supersaturation of gases in the blood (i.e., rectified 
diffusion). 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 (Rommel 
et al., 2006). 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 MFAS/HFAS 
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 MFAS/
HFAS can lead to strandings is included in the Behaviorally Mediated 
Bubble Growth Section, after the summary of strandings.

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 as, 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.

[[Page 53817]]

    Richardson et al. (1995b) argued that the maximum radius of 
influence of an industrial noise (including broadband low frequency 
sound transmission) on a marine mammal is the distance from the source 
to the point at which the noise can barely be heard. This range is 
determined by either the hearing sensitivity of the animal or the 
background noise level present. Industrial masking is most likely to 
affect some species' ability to detect communication calls and natural 
sounds (i.e., surf noise, prey noise, etc.; Richardson et al., 1995).
    The echolocation calls of toothed whales are subject to masking by 
high frequency sound. Human data indicate low-frequency sound can mask 
high-frequency sounds (i.e., upward masking). Studies on captive 
odontocetes by Au et al. (1974, 1985, 1993) indicate that some species 
may use various processes to reduce masking effects (e.g., adjustments 
in echolocation call intensity or frequency as a function of background 
noise conditions). There is also evidence that the directional hearing 
abilities of odontocetes are useful in reducing masking at the high-
frequencies these cetaceans use to echolocate, but not at the low-to-
moderate frequencies they use to communicate (Zaitseva et al., 1980). A 
recent study by Nachtigall and Supin (2008) showed that false killer 
whales adjust their hearing to compensate for ambient sounds and the 
intensity of returning echolocation signals.
    As mentioned previously, the functional hearing ranges of 
odontocetes, pinnipeds underwater, and mysticetes all overlap the 
frequencies of the MFAS/HFAS sources used in the Navy's MFAS/HFAS 
training exercises (although some mysticete's best hearing capacities 
are likely at frequencies somewhat lower than MFAS). Additionally, in 
almost all species, vocal repertoires span across the frequencies of 
these MFAS/HFAS 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 MFAS/HFAS, which 
accounts for the largest part of the takes of marine mammals (because 
of the source strength and number of hours it's conducted), the pulse 
length and duty cycle of the MFAS/HFAS signal (~ 1 second pulse twice a 
minute) makes it less likely that masking will occur as a result.

Impaired Communication

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

Stress Responses

    Classic stress responses begin when an animal's central nervous 
system perceives a potential threat to its homeostasis. That perception 
triggers stress responses regardless of whether a stimulus actually 
threatens the animal; the mere perception of a threat is sufficient to 
trigger a stress response (Moberg, 2000; Sapolsky et al., 2005; Seyle, 
1950). Once an animal's central nervous system perceives a threat, it 
mounts a biological response or defense that consists of a combination 
of the four general biological defense responses: behavioral responses, 
autonomic nervous system responses, neuroendocrine responses, or immune 
response.
    In the case of many stressors, an animal's first and most 
economical (in terms of biotic costs) response is behavioral avoidance 
of the potential stressor or avoidance of continued exposure to a 
stressor. An animal's second line of defense to stressors involves the 
sympathetic part of the autonomic nervous system and the classical 
``fight or flight'' response which includes the cardiovascular system, 
the gastrointestinal system, the exocrine glands, and the adrenal 
medulla to produce changes in heart rate, blood pressure, and 
gastrointestinal activity that humans commonly associate with 
``stress.'' These responses have a relatively short duration and may or 
may not have significant long-term effect on an animal's welfare.
    An animal's third line of defense to stressors involves its 
neuroendocrine or sympathetic nervous systems; the system that has 
received the most study has been the hypothalmus-pituitary-adrenal 
system (also known as the HPA axis in mammals or the hypothalamus-
pituitary-interrenal axis in fish and some reptiles). Unlike stress 
responses associated with the autonomic nervous system, virtually all 
neuro-endocrine functions that are affected by stress--including immune 
competence, reproduction, metabolism, and behavior--are regulated by 
pituitary hormones. Stress-induced changes in the secretion of 
pituitary hormones have been implicated in failed reproduction (Moberg, 
1987; Rivier, 1995) and 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

[[Page 53818]]

cost of the stress response would not pose a risk to the animal's 
welfare. However, when an animal does not have sufficient energy 
reserves to satisfy the energetic costs of a stress response, energy 
resources must be diverted from other biotic 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 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 a stimuli.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses have also been documented 
fairly well through controlled experiment; 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). Although no information has been collected on the physiological 
responses of marine mammals to exposure to anthropogenic sounds, 
studies of other marine animals and terrestrial animals would 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) identified noise-induced physiological transient stress 
responses in hearing-specialist fish (i.e., goldfish) that accompanied 
short- and long-term hearing losses. Welch and Welch (1970) reported 
physiological and behavioral stress responses that accompanied damage 
to the inner ears of fish and several mammals.
    Hearing is one of the primary senses marine mammals use to gather 
information about their environment and to communicate with 
conspecifics. Although empirical information on the relationship 
between sensory impairment (TTS, PTS, and acoustic masking) on marine 
mammals remains limited, it seems reasonable to assume that reducing an 
animal's ability to gather information about its environment and to 
communicate with other members of its species would be stressful for 
animals that use hearing as their primary sensory mechanism. Therefore, 
we assume that acoustic exposures sufficient to trigger onset PTS or 
TTS would be accompanied by physiological stress responses because 
terrestrial animals exhibit those responses under similar conditions 
(NRC, 2003). More importantly, marine mammals might experience stress 
responses at received levels lower than those necessary to trigger 
onset TTS. Based on empirical studies of the time required to recover 
from stress responses (Moberg, 2000), NMFS also assumes that stress 
responses could persist beyond the time interval required for animals 
to recover from TTS and might result in pathological and pre-
pathological states that would be as significant as behavioral 
responses to TTS.

Behavioral Disturbance

    Behavioral responses to sound are highly variable and context-
specific. Many different variables can influence an animal's perception 
of and response to (in both 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 (but is 
not limited to) no response or any of the following observable 
responses: increased alertness; orientation or attraction to a sound 
source; vocal modifications; cessation of feeding; cessation of social 
interaction; alteration of movement or diving behavior; avoidance; 
habitat abandonment (temporary or permanent); and, in severe cases, 
panic, flight, stampede, or stranding, potentially resulting in death 
(Southall et al., 2007). A review of marine mammal responses to 
anthropogenic sound was first conducted by Richardson (1995). 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.
    Alteration of Diving or Movement--Changes in dive behavior can vary 
widely. They may consist of increased or decreased dive times and 
surface intervals as well as changes in the rates of ascent and descent 
during a dive. Variations in dive behavior may reflect interruptions in 
biologically significant activities (e.g., foraging) or they may be of 
little biological significance. Variations in dive behavior may also

[[Page 53819]]

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, a reaction, 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 varied nature of behavioral effects and consequent 
difficulty in defining and predicting them.
    Foraging--Disruption of feeding behavior can be difficult to 
correlate with anthropogenic sound exposure, so it is usually inferred 
by observed displacement from known foraging areas, the appearance of 
secondary indicators (e.g., bubble nets or sediment plumes), or changes 
in dive behavior. Noise from seismic surveys was not found to impact 
the feeding behavior in western grey whales off the coast of Russia 
(Yazvenko et al., 2007) and sperm whales engaged in foraging dives did 
not abandon dives when exposed to distant signatures of seismic airguns 
(Madsen et al., 2006). Balaenopterid whales exposed to moderate SURTASS 
LFA 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 level at the animals was 
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.
    Brownell (2004) reported the behavioral responses of western gray 
whales off the northeast coast of Sakhalin Island to sounds produced by 
seismic activities in that region. In 1997, the gray whales responded 
to seismic activities by changing their swimming speed and orientation, 
respiration rates, and distribution in waters around the seismic 
surveys. In 2001, seismic activities were conducted in a known feeding 
area of these whales and the whales left the feeding area and moved to 
areas farther south in the Sea of Okhotsk. They only returned to the 
feeding area several days after the seismic activities stopped. The 
potential fitness consequences of displacing these whales, especially 
mother-calf pairs and ``skinny whales,'' outside of their normal 
feeding area is not known; however, because gray whales, like other 
large whales, must gain enough energy during the summer foraging season 
to last them the entire year, sounds or other stimuli that cause them 
to abandon a foraging area for several days could disrupt their 
energetics and force them to make trade-offs like delaying their 
migration south, delaying reproduction, reducing growth, or migrating 
with reduced energy reserves.
    Social relationships--Social interactions between mammals can be 
affected by noise via the disruption of communication signals or by the 
displacement of individuals. Sperm whales responded to military sonar, 
apparently from a submarine, by dispersing from social aggregations, 
moving away from the sound source, remaining relatively silent and 
becoming difficult to approach (Watkins et al., 1985). In contrast, 
sperm whales in the Mediterranean that were exposed to submarine sonar 
continued calling (J. Gordon pers. Comm. cited in Richardson et al., 
1995). Social disruptions must be considered, however, in context of 
the relationships that are affected. While some disruptions may not 
have deleterious effects, long-term or repeated disruptions of mother/
calf pairs or interruption of mating behaviors have the potential to 
affect the growth and survival or reproductive effort/success of 
individuals, 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 
United States 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

[[Page 53820]]

the affected region if they do not become acclimated to the presence of 
the chronic 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 mid-frequency active sonar 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 the behavior, movement, and underwater 
vocalizations. The two types of sonar signals (which both contained 
both 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 (Orcinus orca) that had been fitted with D-tags 
were exposed to mid-frequency active sonar (Source A: a 1.0 s upsweep 
209 dB @ 1-2 kHz every 10 seconds for 10 minutes; Source B: with a 1.0 
s upsweep 197 dB @ 6-7 kHz every 10 s for 10 min). 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 immediately swimming away (horizontally) from the 
source of the sound; by engaging in a series of erratic and frequently 
deep dives that seem to take it below the sound field; or by 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 the series of behavioral response studies 
conducted by NMFS and other scientists showed one beaked whale 
(Mesoplodon densirostris) responding to an MFAS playback. The BRS-07 
Cruise report 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 BRS-07 Cruise report notes that 
the results are from a single experiment and that a greater sample size 
is needed before robust and definitive conclusions can be drawn (NMFS, 
2008). The BRS-08 Cruise report has not been published yet.
    Flight Response--A flight response is a dramatic change in normal 
movement to a directed and rapid movement away from the perceived 
location of a sound source. Relatively little information on flight 
responses of marine mammals to anthropogenic signals exist, although 
observations of flight responses to the presences of predators have 
occurred (Connor and Heithaus, 1996). Flight responses have been 
speculated as being a component of marine mammal strandings associated 
with MFAS activities (Evans and England, 2001). If marine mammals 
respond to Navy vessels that are transmitting active sonar in the same 
way that they might respond to a predator, their probability of flight 
responses should increase when they perceive that Navy vessels are 
approaching them directly, because a direct approach may convey 
detection and intent to capture (Burger and Gochfeld, 1981, 1990, 
Cooper, 1997, 1998). The probability of avoidance and 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, 2001b), ringed 
seals Phoca hispida (Born et al., 1999), Pacific brant (Branta bernicl 
nigricans) and Canada geese (B. Canadensis) increased as a helicopter 
or fixed-wing aircraft 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).
    Breathing--Variations in respiration naturally vary with different 
behaviors and variations in respiration rate as a function of acoustic 
exposure can be expected to co-occur with other behavioral reactions, 
such as a flight response or an alteration in diving. However, 
respiration rates in and of themselves may be representative of 
annoyance or an acute stress response. Mean exhalation rates of gray 
whales at rest and while diving were found to be unaffected by seismic 
surveys conducted adjacent to the whale feeding grounds (Gailey et al., 
2007). Studies with captive harbor porpoises showed increased 
respiration rates upon introduction of acoustic alarms (Kastelein et 
al., 2001; Kastelein et al., 2006a) and emissions for underwater data 
transmission (Kastelein et al., 2005). However, exposure of the same 
acoustic alarm to a striped dolphin under the same conditions did not 
elicit a response (Kastelein et al., 2006a), again highlighting the 
importance in understanding species differences in the tolerance of 
underwater noise when determining the potential for impacts resulting 
from anthropogenic sound exposure.
    Continued Pre-disturbance Behavior and Habituation--Under some 
circumstances, some of the individual marine mammals that are exposed 
to active sonar transmissions will continue their normal behavioral 
activities; in other circumstances, individual animals will become 
aware of the sonar transmissions at lower received levels and move to 
avoid additional exposure or exposures at higher received levels 
(Richardson et al., 1995).
    It is difficult to distinguish between animals that continue their 
pre-disturbance behavior without stress responses, animals that 
continue their behavior but experience stress responses (that is, 
animals that cope with disturbance), and animals that habituate to 
disturbance (that is, they may have experienced low-level stress 
responses

[[Page 53821]]

initially, but those responses abated over time). Watkins (1986) 
reviewed data on the behavioral reactions of fin, humpback, right and 
minke whales that were exposed to continuous, broadband low-frequency 
shipping and industrial noise in Cape Cod Bay. He concluded that 
underwater sound was the primary cause of behavioral reactions in these 
species of whales and that the whales responded behaviorally to 
acoustic stimuli within their respective hearing ranges. Watkins also 
noted that whales showed the strongest behavioral reactions to sounds 
in the 15 Hz to 28 kHz range, although negative reactions (avoidance, 
interruptions in vocalizations, etc.) were generally associated with 
sounds that were either unexpected, too loud, suddenly louder or 
different, or perceived as being associated with a potential threat 
(such as an approaching ship on a collision course). In particular, 
whales seemed to react negatively when they were within 100 m of the 
source or when received levels increased suddenly in excess of 12 dB 
relative to ambient sounds. At other times, the whales ignored the 
source of the signal and all four species habituated to these sounds.
    Nevertheless, Watkins concluded that whales ignored most sounds in 
the background of ambient noise, including the sounds from distant 
human activities even though these sounds may have had considerable 
energies at frequencies well within the whales' range of hearing. 
Further, he noted that of the whales observed, fin whales were the most 
sensitive of the four species, followed by humpback whales; right 
whales were the least likely to be disturbed and generally did not 
react to low-amplitude engine noise. By the end of his period of study, 
Watkins (1986) concluded that fin and humpback whales have generally 
habituated to the continuous and broadband noise of Cape Cod Bay while 
right whales did not appear to change their response. As mentioned 
above, animals that habituate to a particular disturbance may have 
experienced low-level stress responses initially, but those responses 
abated over time. In most cases, this likely means a lessened immediate 
potential effect from a disturbance; however, concern exists where the 
habituation occurs in a potentially more harmful situation, for 
example: animals may become more vulnerable to vessel strikes once they 
habituate to vessel traffic (Swingle et al., 1993; Wiley et al., 1995).
    Aicken et al., (2005) monitored the behavioral responses of marine 
mammals to a new low-frequency active sonar system that was being 
developed for use by the British Navy. During those trials, fin whales, 
sperm whales, Sowerby's beaked whales, long-finned pilot whales 
(Globicephala melas), Atlantic white-sided dolphins, and common 
bottlenose dolphins were observed and their vocalizations were 
recorded. These monitoring studies detected no evidence of behavioral 
responses that the investigators could attribute to exposure to the 
low-frequency active sonar during these trials.

Behavioral Responses (Southall et al. (2007))

    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 is 
considered a non-pulse sound. Southall et al. (2007) summarize the 
studies associated with low-frequency, mid-frequency, and high-
frequency cetacean and pinniped responses to non-pulse sounds, based 
strictly on received level, in Appendix C of their article 
(incorporated by reference and summarized in the three paragraphs 
below).
    The studies that address responses of low frequency cetaceans to 
non-pulse sounds include data gathered in the field and related to 
several types of sound sources (of varying similarity to MFAS/HFAS) 
including: vessel noise, drilling and machinery playback, low-frequency 
M-sequences (sine wave with multiple phase reversals) playback, 
tactical low-frequency active sonar playback, drill ships, Acoustic 
Thermometry of Ocean Climate (ATOC) source, and non-pulse playbacks. 
These studies generally indicate no (or very limited) responses to 
received levels in the 90 to 120 dB re: 1 [micro]Pa range and an 
increasing likelihood of avoidance and other behavioral effects in the 
120 to 160 dB range. As mentioned earlier, though, contextual variables 
play a very important role in the reported responses and the severity 
of effects are not linear when compared to received level. Also, few of 
the laboratory or field datasets had common conditions, behavioral 
contexts or sound sources, so it is not surprising that responses 
differ.
    The studies that address responses of mid-frequency cetaceans to 
non-pulse sounds include data gathered both in the field and the 
laboratory and related to several different sound sources (of varying 
similarity to MFAS/HFAS) including: pingers, drilling playbacks, ship 
and ice-breaking noise, vessel noise, Acoustic Harassment Devices 
(AHDs), Acoustic Deterrent Devices (ADDs), MFAS, and non-pulse bands 
and tones. Southall et al. (2007) were unable to come to a clear 
conclusion regarding the results of these studies. In some cases, 
animals in the field showed significant responses to received levels 
between 90 and 120 dB, while in other cases these responses were not 
seen in the 120 to 150 dB range. The disparity in results was likely 
due to contextual variation and the differences between the results in 
the field and laboratory data (animals typically responded at lower 
levels in the field).
    The studies that address responses of high frequency cetaceans to 
non-pulse sounds include data gathered both in the field and the 
laboratory and related to several different sound sources (of varying 
similarity to MFAS/HFAS) including: pingers, AHDs, and various 
laboratory non-pulse sounds. All of these data were collected from 
harbor porpoises. Southall et al. (2007) concluded that the existing 
data indicate that harbor porpoises are likely sensitive to a wide 
range of anthropogenic sounds at low received levels (~90-120 dB), at 
least for initial exposures. All recorded exposures above 140 dB 
induced profound and sustained avoidance behavior in wild harbor 
porpoises (Southall et al., 2007). Rapid habituation was noted in some 
but not all studies. There is no data to indicate whether other high 
frequency cetaceans are as sensitive to anthropogenic sound as harbor 
porpoises are.
    The studies that address the responses of pinnipeds in water to 
non-pulse sounds include data gathered both in

[[Page 53822]]

the field and the laboratory and related to several different sound 
sources (of varying similarity to MFAS/HFAS) including: AHDs, ATOC, 
various non-pulse sounds used in underwater data communication; 
underwater drilling, and construction noise. Few studies exist with 
enough information to include them in the analysis. The limited data 
suggested that exposures to non-pulse sounds between 90 and 140 dB 
generally do not result in strong behavioral responses in pinnipeds in 
water, but no data exist at higher received levels.
    In addition to summarizing the available data, the authors of 
Southall et al. (2007) developed a severity scaling system with the 
intent of ultimately being able to assign some level of biological 
significance to a response. Following is a summary of their scoring 
system; a comprehensive list of the behaviors associated with each 
score may be found in the report:

<bullet> 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)
<bullet> 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)
<bullet> 7-9 (Behaviors considered likely to affect the aforementioned 
vital rates) includes, but is not limited to: extensive or prolonged 
aggressive behavior; moderate, prolonged or significant separation of 
females and dependent offspring with disruption of acoustic reunion 
mechanisms; long-term avoidance of an area; outright panic, stampede, 
stranding; threatening or attacking sound source (in laboratory)

    In Table 6 we have summarized the scores that Southall et al. 
(2007) assigned to the papers that reported behavioral responses of 
low-frequency cetaceans, mid-frequency cetaceans, and pinnipeds in 
water to non-pulse sounds. This table is included simply to summarize 
the findings of the studies and opportunistic observations (all of 
which were capable of estimating received level) that Southall et al. 
(2007) compiled in the effort to develop acoustic criteria.
[GRAPHIC] [TIFF OMITTED] TP20OC09.006

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 are little quantitative marine mammal data relating 
the exposure of marine mammals to sound to effects on reproduction or 
survival, though data exist for terrestrial species to which we can 
draw comparisons for marine mammals. Several authors have reported that 
disturbance stimuli cause animals to abandon nesting and foraging sites 
(Sutherland and Crockford, 1993), cause animals to increase their 
activity levels and suffer premature deaths or reduced reproductive 
success when their energy expenditures exceed their energy budgets 
(Daan et al., 1996, Feare 1976, Giese 1996, Mullner et al., 2004, 
Waunters et al., 1997), or cause animals to experience higher predation 
rates when they adopt risk-prone foraging or migratory strategies (Frid 
and Dill, 2002). Each of these studies addressed the consequences that 
result when animals shift from one behavioral state (for example, 
resting or foraging) to another behavioral state (avoidance or escape 
behavior) because of human disturbance or disturbance stimuli.
    One consequence of behavioral avoidance results from changing the 
energetics of marine mammals because of the energy required to avoid 
surface vessels or the sound field associated with active sonar (Frid 
and Dill, 2002). Most animals can avoid that energetic cost by swimming 
away at slow speeds or those speeds that are at or near the minimum 
cost of transport (Miksis-Olds, 2006), as has been demonstrated in 
Florida manatees (Hartman, 1979, Miksis-Olds, 2006).
    Those costs increase, however, when animals shift from a resting 
state, which is designed to conserve an animal's energy, to an active 
state that consumes energy the animal would have conserved had it not 
been disturbed. Marine mammals that have been disturbed by 
anthropogenic noise and vessel approaches are commonly reported to 
shift from resting behavioral states to active behavioral states, which 
would imply that they incur an energy cost. Morete et al., (2007) 
reported that undisturbed humpback whale cows that were accompanied by 
their calves were frequently observed resting while their calves 
circled them (milling) and rolling interspersed with dives. When 
vessels approached, the amount of time cows and calves spent resting 
and milling, respectively declined significantly. These results are 
similar to those reported by Scheidat et al. (2004) for the

[[Page 53823]]

humpback whales they observed off the coast of Ecuador.
    Constantine and Brunton (2001) reported that bottlenose dolphins in 
the Bay of Islands, New Zealand only engaged in resting behavior 5% of 
the time when vessels were within 300 meters compared with 83% of the 
time when vessels were not present. Miksis-Olds (2006) and Miksis-Olds 
et al. (2005) reported that Florida manatees in Sarasota Bay, Florida, 
reduced the amount of time they spent milling and increased the amount 
of time they spent feeding when background noise levels increased. 
Although the acute costs of these changes in behavior are not likely to 
exceed an animal's ability to compensate, the chronic costs of these 
behavioral shifts are uncertain.
    Attention is the cognitive process of selectively concentrating on 
one aspect of an animal's environment while ignoring other things 
(Posner, 1994). Because animals (including humans) have limited 
cognitive resources, there is a limit to how much sensory information 
they can process at any time. The phenomenon called ``attentional 
capture'' occurs when a stimulus (usually a stimulus that an animal is 
not concentrating on or attending to) ``captures'' an animal's 
attention. This shift in attention can occur consciously or 
unconsciously (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 a 
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 to 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 (Anser brachyrhynchus) in undisturbed habitat gained 
body mass and had about a 46% 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% 
reproductive success rate. Similar reductions in reproductive success 
have been reported for mule deer (Odocoileus hemionus) 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 (Cervus elaphus) that were disturbed 
experimentally by pedestrians concluded that the ratio of young to 
mothers was inversely related to disturbance rate (Phillips and 
Alldredge, 2000).
    The primary mechanism by which increased vigilance and disturbance 
appear to affect the fitness of individual animals is by disrupting an 
animal's time budget and, as a result, reducing the time they might 
spend foraging and resting (which increases an animal's activity rate 
and energy demand). For example, a study of grizzly bears (Ursus 
horribilis) reported that bears disturbed by hikers reduced their 
energy intake by an average of 12 kcal/min (50.2 x 10\3\ kJ/min), 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 five 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-hr 
cycle). Behavioral reactions to noise exposure (such as disruption of 
critical life functions, displacement, or avoidance of important 
habitat) are more likely to be significant if they last more than one 
diel cycle or recur on subsequent days (Southall et al., 2007). 
Consequently, a behavioral response lasting less than one day and not 
recurring on subsequent days is not considered particularly severe 
unless it could directly affect reproduction or survival (Southall et 
al., 2007).

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; National Marine Fisheries Service, 2007p). 
The legal definition for a stranding within the United States is that 
(A) ``a marine mammal is dead and is (i) on a beach or shore of the 
United States; or (ii) in waters under the jurisdiction of the United 
States (including any navigable waters); or (B) a marine mammal is 
alive and is (i) on a beach or shore of the United States and is unable 
to return to the water; (ii) on a beach or shore of the United States 
and, although able to return to the water, is in need of apparent 
medical attention; or (iii) in the waters under the jurisdiction of the 
United States (including any navigable waters), but is unable to return 
to its natural habitat under its own power or without assistance.'' (16 
U.S.C. 1421h).
    Marine mammals are known to strand for a variety of reasons, such 
as infectious agents, biotoxicosis, starvation, fishery interaction, 
ship strike, unusual oceanographic or weather events, sound exposure, 
or combinations of these stressors sustained concurrently or in series. 
However, the cause or causes of most strandings are unknown (Geraci et 
al., 1976; Eaton, 1979, Odell et al., 1980; Best, 1982). Numerous 
studies suggest that the physiology, behavior, habitat 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

[[Page 53824]]

though one exposure without the other does not produce the same result 
(Chroussos, 2000; Creel, 2005; DeVries et al., 2003; Fair and Becker, 
2000; Foley et al., 2001; Moberg, 2000; Relyea, 2005a, 2005b; Romero, 
2004; Sih et al., 2004).
    Several sources have published lists of mass stranding events of 
cetaceans in an attempt to identify relationships between those 
stranding events and military active sonar (Hildebrand, 2004; IWC, 
2005; Taylor et al., 2004). For example, based on a review of stranding 
records between 1960 and 1995, the International Whaling Commission 
(2005) identified ten mass stranding events of Cuvier's beaked whales 
that had been reported and one mass stranding of four Baird's beaked 
whales (Berardius bairdii). 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 MFAS, 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 IWC involved beaked 
whales. A mass stranding of Cuvier's beaked whales in the eastern 
Mediterranean Sea occurred in 1996 (Franzis, 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 
exercises involving the use of MFAS.

Strandings Associated With MFAS

    Over the past 12 years, there have been five stranding events 
coincident with military mid-frequency active sonar use in which 
exposure to sonar is believed by NMFS and the Navy to have been a 
contributing factor: Greece (1996); the Bahamas (2000); Madeira (2000); 
Canary Islands (2002); and Spain (2006). Additionally, in 2004, during 
the RIMPAC exercises, between 150-200 usually pelagic melon-headed 
whales occupied the shallow waters of the Hanalei Bay, Kaua'i, Hawaii 
for over 28 hours. NMFS determined that the mid-frequency sonar was a 
plausible, if not likely, contributing factor in what may have been a 
confluence of events that led to the Hanalei Bay stranding. A number of 
other stranding events coincident with the operation of MFAS including 
the death of beaked whales or other species (Minke whales, dwarf sperm 
whales, pilot whales) have been reported; however, the majority have 
not been investigated to the degree necessary to determine the cause of 
the stranding and only one of these exercises was conducted by the U.S. 
Navy.

Greece (1996)

    Twelve Cuvier's beaked whales stranded atypically (in both time and 
space) along a 38.2-kilometer strand of the coast of the Kyparissiakos 
Gulf on May 12 and 13, 1996 (Frantzis, 1998). From May 11 through May 
15, the NATO research vessel Alliance was conducting active 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 the location of the testing encompassed the time 
and location of the whale 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 
(Frantzis, 2004). 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 (Frantzis, 2004). 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. Their official finding was ``An acoustic link can neither be 
clearly established, nor eliminated as a direct or indirect cause for 
the May 1996 strandings.'' The analysis of this stranding event 
provided support for, but no clear evidence for, the cause-and-effect 
relationship of active 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 MFAS 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 (5 Cuvier's beaked whales, 1 
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

[[Page 53825]]

blood clots in the lateral ventricles, were found in two of the whales. 
Three of the whales had small hemorrhages in their acoustic fats 
(located along the jaw and in the melon).
    A comprehensive investigation was conducted and all possible causes 
of the stranding event were considered, whether they seemed likely at 
the outset or not. Based on the way in which the strandings coincided 
with ongoing naval activity involving tactical MFAS use, in terms of 
both time and geography, the nature of the physiological effects 
experienced by the dead animals, and the absence of any other acoustic 
sources, the investigation team concluded that MFAS aboard U.S. Navy 
ships that were in use during the active sonar exercise in question 
were the most plausible source of this acoustic or impulse trauma to 
beaked whales. This sound source was active in a complex environment 
that included the presence of a surface duct, unusual and steep 
bathymetry, a constricted channel with limited egress, intensive use of 
multiple, active sonar units over an extended period of time, and the 
presence of beaked whales that appear to be sensitive to the 
frequencies produced by these active sonars. The investigation team 
concluded that the cause of this stranding event was the confluence of 
the Navy MFAS and these contributory factors working together, and 
further recommended that the Navy avoid operating MFAS in situations 
where these five factors would be likely to occur. This report does not 
conclude that all five of these factors must be present for a stranding 
to occur, nor that beaked whales are the only species that could 
potentially be affected by the confluence of the other factors. Based 
on this, NMFS believes that the operation of MFAS in situations where 
surface ducts exist, or in marine environments defined by steep 
bathymetry and/or constricted channels may increase the likelihood of 
producing a sound field with the potential to cause cetaceans 
(especially beaked whales) to strand, and therefore, suggests the need 
for increased vigilance while operating MFAS in these areas, especially 
when beaked whales (or potentially other deep divers) are likely 
present.

Madeira, Spain (2000)

    From May 10-14, 2000, three Cuvier's beaked whales were found 
atypically stranded on two islands in the Madeira archipelago, Portugal 
(Cox et al., 2006). A fourth animal was reported floating in the 
Madeiran waters by fishermen but did not come ashore (Woods Hole 
Oceanographic Institution, 2005). Joint NATO amphibious training 
peacekeeping exercises involving participants from 17 countries aboard 
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 (1000 m) depth near a 
shoreline where there is a rapid change in bathymetry on the order of 
547 to 3,281 (1000-6000 m) fathoms 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); exercises took place in an area surrounded by land 
masses 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 (1000 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 3 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).

[[Page 53826]]

    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 active 
sonar use, suggests that a similar scenario and causative mechanism of 
stranding may be shared between the events. Beaked whales stranded in 
this event demonstrated brain and auditory system injuries, 
hemorrhages, and congestion in multiple organs, similar to the 
pathological findings of the Bahamas and Madeira stranding events. In 
addition, the necropsy results of Canary Islands stranding event lead 
to the hypothesis that the presence of disseminated and widespread gas 
bubbles and fat emboli were indicative of nitrogen bubble formation, 
similar to what might be expected in decompression sickness (Jepson et 
al., 2003; Fern[aacute]ndez et al., 2005).

Spain (2006)

    The Spanish Cetacean Society reported an atypical mass stranding of 
four beaked whales that occurred January 26, 2006, on the southeast 
coast of Spain, near Mojacar (Gulf of Vera) in the Western 
Mediterranean Sea. According to the report, two of the whales were 
discovered the evening of January 26 and were found to be still alive. 
Two other whales were discovered during the day on January 27, but had 
already died. The fourth animal was found dead on the afternoon of 
January 27, a few kilometers north of the first three animals. From 
January 25-26, 2006, Standing North Atlantic Treaty Organization (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 (1000 m) depth near a shoreline where there is a 
rapid change in bathymetry on the order of 547 to 3,281 fathoms (1000-
6000 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; 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).

Hanalei Bay (2004)

    On July 3-4, 2004, approximately 150-200 melon-headed whales 
occupied the shallow waters of the Hanalei Bay, Kaua'i, Hawaii for over 
28 hours. 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. Although cause of death could 
not be definitively determined, 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 movement into the Bay, the milling and 
re-grouping may have contributed to the separation or lack of nursing 
especially if the maternal bond was weak or this was a primiparous 
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 United States. 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 or 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 Kaua'i could have detected active sonar transmissions 
on July 2, and reached Hanalei Bay on or before 7 a.m. on July 3, 2004. 
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 suggest 
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, 2004. 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: (1) The 
evidently anomalous nature of the stranding; (2) its close 
spatiotemporal correlation with wide-

[[Page 53827]]

scale, sustained use of sonar systems previously associated with 
stranding of deep-diving marine mammals; (3) the directed movement of 
two groups of transmitting vessels toward the southeast and southwest 
coast of Kauai; (4) the results of acoustic propagation modeling and an 
analysis of possible animal transit times to the Bay; and (5) the 
absence of any other compelling causative explanation. The initiation 
and persistence of this event may have resulted from an interaction of 
biological and physical factors. The biological factors may have 
included the presence of an apparently uncommon, deep-diving cetacean 
species (and possibly an offshore, non-resident group), social 
interactions among the animals before or after they entered the Bay, 
and/or unknown predator or prey conditions. The physical factors may 
have included the presence of nearby deep water, multiple vessels 
transiting in a directed manner while transmitting active sonar over a 
sustained period, the presence of surface sound ducting conditions, 
and/or intermittent and random human interactions while the animals 
were in the Bay.
    A separate event involving melon-headed whales and rough-toothed 
dolphins took place over the same period of time in the Northern 
Mariana Islands (Jefferson et al., 2006), which is several thousand 
miles from Hawaii. Some 500-700 melon-headed whales came into Sasanhaya 
Bay on 4 July 2004 on 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 not a correlation between lunar cycle and the types of 
behaviors observed in the Brownell et al., (2009) examples.

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% of the total number of stranded 
animals), other beaked whales (including Mesoplodon europeaus, M. 
densirostris, and Hyperoodon ampullatus) comprise 14% of the total. 
Other species, such as Kogia breviceps, have stranded in association 
with the operation of MFAS, 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 active 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 
(acoustically mediated bubble growth, addressed above) prior to 
stranding or whether a behavioral response to sound occurred that 
ultimately caused the beaked whales to be injured and to strand.
    Although causal relationships between beaked whale stranding events 
and active sonar remain unknown, several authors have hypothesized that 
stranding events involving these species in the Bahamas and Canary 
Islands may have been triggered when the whales changed their dive 
behavior in a startled response to exposure to active sonar or to 
further avoid exposure (Cox et al., 2006; Rommel et al., 2006). These 
authors proposed three mechanisms by which the behavioral responses of 
beaked whales upon being exposed to active sonar might result in a 
stranding event. These include: 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), which would increase their oxygen. 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 MFAS. 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

[[Page 53828]]

suggests that abnormally rapid ascents or premature dives in response 
to high-intensity active sonar could indirectly result in physical harm 
to the beaked whales, through the mechanisms described above (gas 
bubble formation or non-elimination of excess nitrogen).
    Because many species of marine mammals make repetitive and 
prolonged dives to great depths, it has long been assumed that marine 
mammals have evolved physiological mechanisms to protect against the 
effects of rapid and repeated decompressions. Although several 
investigators have identified physiological adaptations that may 
protect marine mammals against nitrogen gas supersaturation (alveolar 
collapse and elective circulation; Kooyman et al., 1972; Ridgway and 
Howard, 1979), Ridgway and Howard (1979) reported that bottlenose 
dolphins (Tursiops truncatus) 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 of up to 2 kilometers) and 
long (as long as 90 minutes) foraging dives with (2) relatively slow, 
controlled ascents, followed by (3) a series of ``bounce'' dives 
between 100 and 400 meters 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.
    Recently, 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 active 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 MFAS (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 (Baird et al., 2008). 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.
    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.
    Although not all of the five environmental factors believed to have 
contributed to the Bahamas stranding (at least 3 surface vessel MFAS 
sources operating simultaneously or in conjunction with one another, 
beaked whale presence, surface ducts, steep bathymetry, and constricted 
channels with limited egress) will be present during exercises in the 
MIRC Study area (the MIRC study area does not contain similar 
bathymetric features), NMFS recommends caution when either steep 
bathymetry, surface ducting conditions (which are present in the MIRC 
study area), or a constricted channel is present when mid-frequency 
active sonar is employed by multiple surface vessels simultaneously and 
cetaceans (especially beaked whales) are present.

LFA Sonar

    Analysis of the environmental impacts of the SURTASS LFA sonar 
system, including the potential for synergistic and cumulative effects 
with MFAS operation, has been addressed to some degree in the Navy's 
SURTASS LFA Sonar EISs and more recently in NMFS' August, 2009 
biological opinion for SURTASS LFA Sonar. The take of marine mammals 
incidental to the operation of LFA sonar in the MIRC and elsewhere has 
been previously authorized by NOAA/NMFS (2002a, 2007).
    Although the authorization of take of marine mammals incidental to 
the operation of LFA sonar will not be considered here because it has 
already been separately authorized, NMFS has considered more 
specifically the manner in which LFA sonar and MFAS may interact in a 
multi-strike group exercise with respect to the potential to impact 
marine mammals in a manner not previously considered.
    As mentioned previously, the military intends to conduct three 
exercises (multi-strike group exercises) during the five-year duration 
of the rule that may include both SURTASS LFA and MFA sonar sources. 
The expected duration of these combined exercises is approximately 14 
days. Based on an exercise of this length, an LFA sonar system would be 
active (i.e., actually transmitting) for no more than approximately 25 
hours. Tactical and technical considerations dictate that the LFA sonar 
ship would typically be tens of miles from the MFA sonar ship when 
using active sonar.
    It is unlikely, but possible, that both LFA and MFA sonar would be 
active at exactly the same time during a major exercise. In the 
unlikely event that both systems were operating simultaneously, the 
likelihood of more than a relatively small number of individual marine 
mammals being physically present at a time, location, and depth to be 
able to receive both LFA and MFA sonar signals at levels of concern at 
the same time is even smaller as the sound from

[[Page 53829]]

both signals would have attenuated when they reached the marine mammal 
in question, so even a simultaneous exposure would not be at the full 
signal of either system. Additionally, few species have maximum 
sensitivity to both the low and middle frequencies.
    In terms of estimating hours of such exposure, assuming an LFA and 
MFA sonar source transmitting at the same time over a 25-hour period 
(which is a subset of a nominal 14-day exercise) and based on the fact 
that the two sources transmit at very different duty cycles, the 
overlap of the actual signals would be approximately 3.2%, or 0.8 hours 
(assuming that there is only one MFA sonar ship transmitting). But the 
possibility of even that overlap must consider the other factors 
discussed above.
    Based on the fact that an LFA sonar ship would be tens of miles 
away from an MFA ship when using active sonar and that the overlap of 
the signals would only be about 50 minutes, the potential impacts on 
marine mammals that might be exposed simultaneously to both MFA and LFA 
sonars would be limited and not significant.

Exposure to Underwater Detonation of Explosives

    Some of the Navy's training exercises include the underwater 
detonation of explosives. For many of the exercises discussed, inert 
ordnance is used for a subset of the exercises. For exercises that 
involve ``shooting'' at a target that is above the surface of the 
water, underwater explosions only occur when the target is missed, 
which is the minority of the time (the Navy has historical hit/miss 
ratios and uses them in their exposure estimates). The underwater 
explosion from a weapon would send a shock wave and blast noise through 
the water, release gaseous by-products, create an oscillating bubble, 
and cause a plume of water to shoot up from the water surface. The 
effects of an underwater explosion on a marine mammal depends on many 
factors, including the size, type, and depth of both the animal and the 
explosive charge; the depth of the water column; and the standoff 
distance between the charge and the animals, as well as the sound 
propagation properties of the environment. Potential impacts can range 
from brief effects (such as behavioral disturbance), tactile 
perception, physical discomfort, slight injury of the internal organs 
and the auditory system, to death of the animal (Yelverton et al., 
1973; O'Keeffe and Young, 1984; DoN, 2001). Non-lethal injury includes 
slight injury to internal organs and the auditory system; however, 
delayed lethality can be a result of individual or cumulative sublethal 
injuries (DoN, 2001). Immediate lethal injury would be a result of 
massive combined trauma to internal organs as a direct result of 
proximity to the point of detonation (DoN, 2001).'' Generally, 
exposures to higher levels of impulse and pressure levels would result 
in worse impacts to an individual animal.
    Injuries resulting from a shock wave take place at boundaries 
between tissues of different density. Different velocities are imparted 
to tissues of different densities, and this can lead to their physical 
disruption. Blast effects are greatest at the gas-liquid interface 
(Landsberg, 2000). Gas-containing organs, particularly the lungs and 
gastrointestinal tract, are especially susceptible (Goertner, 1982; 
Hill, 1978; Yelverton et al., 1973). In addition, gas-containing organs 
including the nasal sacs, larynx, pharynx, trachea, and lungs may be 
damaged by compression/expansion caused by the oscillations of the 
blast gas bubble (Reidenberg and Laitman, 2003). Intestinal walls can 
bruise or rupture, with subsequent hemorrhage and escape of gut 
contents into the body cavity. Less severe gastrointestinal tract 
injuries include contusions, petechiae (small red or purple spots 
caused by bleeding in the skin), and slight hemorrhaging (Yelverton et 
al., 1973).
    Because the ears are the most sensitive to pressure, they are the 
organs most sensitive to injury (Ketten, 2000). Sound-related trauma 
associated with blast noise can be theoretically distinct from injury 
from the shock wave, particularly farther from the explosion. If an 
animal is able to hear a noise, at some level it can fatigue or damage 
its hearing by causing decreased sensitivity (Ketten, 1995) (See Noise-
induced Threshold Shift Section above). 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 than MFAS/HFAS. However, though the nature 
of the sound waves emitted from an explosion is different (in shape and 
rise time) from MFAS/HFAS, we still anticipate the same sorts of 
behavioral responses (see Exposure to MFAS/HFAS: Behavioral Disturbance 
Section) to result from repeated explosive detonations (a smaller range 
of likely less severe responses would be expected to occur as a result 
of exposure to a single explosive detonation).

Potential Effects of Vessel Movement and Collisions

    Vessel movement in the vicinity of marine mammals has the potential 
to result in either a behavioral response or a direct physical 
interaction. Both scenarios are discussed below.

Vessel Movement

    There are limited data concerning marine mammal behavioral 
responses to vessel traffic and vessel noise, and a lack of consensus 
among scientists with respect to what these responses mean or whether 
they result in short-term or long-term adverse effects. In those cases 
where there is a busy shipping lane or where there is large amount of 
vessel traffic, marine mammals may experience acoustic masking 
(Hildebrand, 2005) if they are present in the area (e.g., killer whales 
in Puget Sound; Foote et al., 2004; Holt et al., 2008). In cases where 
vessels actively approach marine mammals (e.g., whale watching or 
dolphin watching boats), scientists have documented that animals 
exhibit altered behavior such as increased swimming speed, erratic 
movement, and active avoidance behavior (Bursk, 1983; Acevedo, 1991; 
Baker and MacGibbon, 1991; Trites and Bain, 2000; Williams et al., 
2002; Constantine et al., 2003), reduced blow interval (Ritcher et al., 
2003), disruption of normal social behaviors (Lusseau, 2003; 2006), and 
the shift of behavioral activities which may increase energetic costs 
(Constantine et al., 2003; 2004). A detailed review of marine mammal 
reactions to ships and boats is available in Richardson et al. (1995). 
For each of the marine mammals taxonomy groups, Richardson et al. 
(1995) provided the following assessment regarding cetacean reactions 
to vessel traffic:
    Toothed whales: ``In summary, toothed whales sometimes show no

[[Page 53830]]

avoidance reaction to vessels, or even approach them. However, 
avoidance can occur, especially in response to vessels of types used to 
chase or hunt the animals. This may cause temporary displacement, but 
we know of no clear evidence that toothed whales have abandoned 
significant parts of their range because of vessel traffic.''
    Baleen whales: ``When baleen whales receive low-level sounds from 
distant or stationary vessels, the sounds often seem to be ignored. 
Some whales approach the sources of these sounds. When vessels approach 
whales slowly and non-aggressively, whales often exhibit slow and 
inconspicuous avoidance maneuvers. In response to strong or rapidly 
changing vessel noise, baleen whales often interrupt their normal 
behavior and swim rapidly away. Avoidance is especially strong when a 
boat heads directly toward the whale.''
    It is important to recognize that behavioral responses to stimuli 
are complex and influenced to varying degrees by a number of factors 
such as species, behavioral contexts, geographical regions, source 
characteristics (moving or stationary, speed, direction, etc.), prior 
experience of the animal, and physical status of the animal. For 
example, studies have shown that beluga whales reacted differently when 
exposed to vessel noise and traffic. In some cases, na[iuml]ve beluga 
whales exhibited rapid swimming from ice-breaking vessels up to 80 km 
away, and showed changes in surfacing, breathing, diving, and group 
composition in the Canadian high Arctic where vessel traffic is rare 
(Finley et al., 1990). In other cases, beluga whales were more tolerant 
of vessels, but responded differentially to certain vessels and 
operating characteristics by reducing their calling rates (especially 
older animals) in the St. Lawrence River where vessel traffic is common 
(Blane and Jaakson, 1994). In Bristol Bay, Alaska, beluga whales 
continued to feed when surrounded by fishing vessels and resisted 
dispersal even when purposefully harassed (Fish and Vania, 1971).
    In reviewing more than 25 years of whale observation data, Watkins 
(1986) concluded that whale reactions to vessel traffic were ``modified 
by their previous experience and current activity: Habituation often 
occurred rapidly, attention to other stimuli or preoccupation with 
other activities sometimes overcame their interest or wariness of 
stimuli.'' Watkins noticed that over the years of exposure to ships in 
the Cape Cod area, minke whales (Balaenoptera acutorostrata) changed 
from frequent positive (such as approaching vessels) interest to 
generally uninterested reactions; finback whales (B. physalus) changed 
from mostly negative (such as avoidance) to uninterested reactions; 
right whales (Eubalaena glacialis) apparently continued the same 
variety of responses (negative, uninterested, and positive responses) 
with little change; and humpbacks (Megaptera novaeangliae) dramatically 
changed from mixed responses that were often negative to often strongly 
positive reactions. Watkins (1986) summarized that ``whales near shore, 
even in regions with low vessel traffic, generally have become less 
wary of boats and their noises, and they have appeared to be less 
easily disturbed than previously. In particular locations with intense 
shipping and repeated approaches by boats (such as the whale-watching 
areas of Stellwagen Bank), more and more whales had P [positive] 
reactions to familiar vessels, and they also occasionally approached 
other boats and yachts in the same ways.''
    Although the radiated sound from Navy vessels will be audible to 
marine mammals over a large distance, it is unlikely that animals will 
respond behaviorally (in a manner that NMFS would consider MMPA 
harassment) to low-level distant shipping noise as the animals in the 
area are likely to be habituated to such noises (Nowacek et al., 2004). 
In light of these facts, NMFS does not expect the Navy's vessel 
movements to result in Level B harassment.

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 (for example, 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 (for 
example, 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%) resulted in serious injury or death (19 or 33% 
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 or 35% resulted in death). Operating speeds of 
vessels that struck various species of large whales ranged from 2 to 51 
knots. The majority (79%) 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% as vessel speed increased from 10 to 14 
knots, and exceeded 90% 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 go 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

[[Page 53831]]

overall large shipping traffic are very small (on the order of 2%).
    The probability of vessel and marine mammal interactions occurring 
in the MIRC Study Area is dependent upon several factors including 
numbers, types, and speeds of vessels; the regularity, duration, and 
spatial extent of training events; the presence/absence and density of 
marine mammals; and mitigation measures implemented by the Navy. 
Currently, the number of Navy vessels operating in the MIRC Study Area 
varies based on training schedules and can typically range from zero to 
about ten vessels at any given time. Ship sizes range from 362 ft (110 
m) for a nuclear submarine (SSN) to 1,092 ft (331 m) for a nuclear 
aircraft carrier (CVN). Smaller boats such as RHIBS, LCAC, etc. are 
also utilized in the MIRC study area. The smaller boats do not contain 
acoustic sound sources. Speeds are typically within 10 to 14 knots; 
however, slower or faster speeds are possible depending upon the 
specific training scenario. Training involving vessel movements occurs 
intermittently and is variable in duration, ranging from a few hours up 
to two weeks. These training events are widely dispersed. Consequently, 
the density of ships within the MIRC Study Area at any given time is 
extremely low (i.e., less than 0.0002 ships/nm\2\). The Navy logs about 
1,000 total vessel days within the MIRC Study Area during a typical 
year. Vessel days was computed as the number of steaming days per year 
by summing the number of steaming hours proposed in the range complex, 
dividing by 24 hours per day, and rounding to the nearest 10 days.
    Moreover, naval vessels transiting the study area or engaging in 
the training exercises will not actively or intentionally approach a 
marine mammal. While in transit, naval vessels will be alert at all 
times, use extreme caution, and proceed at a ``safe speed'' so that the 
vessel can take proper and effective action to avoid a collision with 
any marine animal and can be stopped within a distance appropriate to 
the prevailing circumstances and conditions. When whales have been 
sighted in the area, Navy vessels will increase vigilance and take 
reasonable and practicable actions to avoid collisions and activities 
that might result in close interaction of naval assets and marine 
mammals. Actions may include changing speed and/or direction and would 
be dictated by environmental and other conditions (e.g., safety, 
weather). For a thorough discussion of mitigation measures, please see 
the Mitigation section.
    Additionally, the majority of ships participating in MIRC training 
activities have a number of advantages for avoiding ship strikes as 
compared to most commercial merchant vessels, including the following:
    <bullet> Navy ships have their bridges positioned forward, offering 
good visibility ahead of the bow.
    <bullet> Crew size is much larger than that of merchant ships 
allowing for more potential observers on the bridge.
    <bullet> Dedicated lookouts are posted during a training activity 
scanning the ocean for anything detectable in the water; anything 
detected is reported to the Officer of the Deck.
    <bullet> Navy lookouts receive extensive training including Marine 
Species Awareness Training designed to provide marine species detection 
cues and information necessary to detect marine mammals.
    <bullet> Navy ships are generally much more maneuverable than 
commercial merchant vessels.
    Based on the implementation of Navy mitigation measures and the low 
density of Navy ships in the Study Area, NMFS has concluded 
preliminarily that the probability of a ship strike is very low, 
especially for dolphins and porpoises, killer whales, social pelagic 
odontocetes and pinnipeds that are highly visible, and/or comparatively 
small and maneuverable. Though more probable, NMFS also believes that 
the likelihood of a Navy vessel striking a mysticete or sperm whale is 
low. The Navy did not request take from a ship strike and based on our 
preliminary determination, NMFS is not recommending that they modify 
their request at this time. However, both NMFS and the Navy are 
currently engaged in a Section 7 consultation under the ESA, and that 
consultation will further inform our final decision.

Mitigation

    In order to issue an incidental take authorization (ITA) under 
Section 101(a)(5)(A) of the MMPA, NMFS must set forth the ``permissible 
methods of taking pursuant to such activity, and other means of 
effecting the least practicable adverse impact on such species or stock 
and its habitat, paying particular attention to rookeries, mating 
grounds, and areas of similar significance.'' The NDAA of 2004 amended 
the MMPA as it relates to military-readiness activities and the ITA 
process such that ``least practicable adverse impact'' shall include 
consideration of personnel safety, practicality of implementation, and 
impact on the effectiveness of the ``military readiness activity''. The 
training activities described in the MIRC application are considered 
military readiness activities.
    NMFS reviewed the proposed MIRC activities and the proposed MIRC 
mitigation measures as described in the Navy's LOA application to 
determine if they would result in the least practicable adverse effect 
on marine mammals, which includes a careful balancing of the likely 
benefit of any particular measure to the marine mammals with the likely 
effect of that measure on personnel safety, practicality of 
implementation, and impact on the effectiveness of the ``military-
readiness activity.'' NMFS identified the need to further flesh out the 
Navy's plan for how to respond in the event of a stranding in the MIRC, 
and the Navy and NMFS subsequently coordinated and produced the draft 
Stranding Response Plan for MIRC, which is summarized below and 
available at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. Included below are the mitigation measures 
the Navy initially proposed (see ``Mitigation Measures Proposed in the 
Navy's LOA Application'') and the Stranding Response Plan that NMFS and 
the Navy developed (see ``Additional Measure Developed by NMFS and the 
Navy'' below).

Mitigation Measures Proposed in the Navy's LOA Application

Personnel Training
    The use of shipboard lookouts is a critical component of all Navy 
protective measures. Lookout 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 serving as 
lookouts on station at all times (day and night) when a ship or 
surfaced submarine is moving through the water.
    <bullet> All commanding officers (COs), executive officers (XOs), 
lookouts, officers of the deck (OODs), junior OODs (JOODs), maritime 
patrol aircraft aircrews, and Anti-submarine Warfare (ASW) helicopter 
crews will complete the NMFS-approved Marine Species Awareness Training 
(MSAT) by viewing the U.S. Navy MSAT digital versatile disk (DVD). All 
bridge lookouts will complete both parts one and two of the MSAT; part 
two is optional for other personnel. This training addresses the 
lookout's role in environmental protection, laws governing the 
protection of marine species, Navy

[[Page 53832]]

stewardship commitments and general observation information to aid in 
avoiding interactions with marine species.
    <bullet> Navy lookouts will undertake extensive training in order 
to qualify as a watchstander in accordance with the Lookout Training 
Handbook (Naval Education and Training Command [NAVEDTRA] 12968-D).
    <bullet> Lookout training will include on-the-job instruction under 
the supervision of a qualified, experienced lookout. Following 
successful completion of this supervised training period, lookouts will 
complete the Personal Qualification Standard Program, certifying that 
they have demonstrated the necessary skills (such as detection and 
reporting of partially submerged objects). Personnel being trained as 
lookouts can be counted among the number of lookeouts required by a 
particular mitigation measure as long as supervisors monitor their 
progress and performance.
    <bullet> Lookouts will be trained in the most effective means to 
ensure quick and effective communication within the command structure 
in order to facilitate implementation of protective measures if marine 
species are spotted.
    <bullet> All lookouts onboard platforms involved in ASW training 
events will review the NMFS-approved Marine Species Awareness Training 
material prior to use of mid-frequency active sonar.
    <bullet> All COs, XOs, and officers standing watch on the bridge 
will have reviewed the Marine Species Awareness Training material prior 
to a training event employing the use of MFAS/HFAS.
General Operating Procedures (for All Training Types)
    Prior to major exercises, a Letter of Instruction, Mitigation 
Measures Message or Environmental Annex to the Operational Order will 
be issued to further disseminate the personnel training requirement and 
general marine species protective measures.
    <bullet> COs will make use of marine species detection cues and 
information to limit interaction with marine species to the maximum 
extent possible consistent with safety of the ship.
    <bullet> While underway, surface vessels will have at least two 
lookouts with binoculars; surfaced submarines will have at least one 
lookout with binoculars. Lookouts already posted for safety of 
navigation and man-overboard precautions may be used to fill this 
requirement. As part of their regular duties, lookouts will watch for 
and report to the OOD the presence of marine mammals.
    <bullet> On surface vessels equipped with a multi-function active 
sensor, pedestal mounted ``Big Eye'' (20x110) binoculars will be 
properly installed and in good working order to assist in the detection 
of marine mammals in the vicinity of the vessel.
    <bullet> Personnel on lookout will employ visual search procedures 
employing a scanning methodology in accordance with the Lookout 
Training Handbook (NAVEDTRA 12968-D).
    <bullet> After sunset and prior to sunrise, lookouts will employ 
Night Lookouts Techniques in accordance with the Lookout Training 
Handbook. (NAVEDTRA 12968-D).
    <bullet> While in transit, naval vessels will be alert at all 
times, use extreme caution, and proceed at a ``safe speed'', which 
means the speed at which CO can maintain crew safety and effectiveness 
of current operational directives, so that the vessel can take action 
to avoid a collision with any marine mammal.
    <bullet> When whales have been sighted in the area, Navy vessels 
will increase vigilance and take all reasonable actions to avoid 
collisions and close interaction of naval assets and marine mammals. 
Actions may include changing speed and/or direction and would be 
dictated by environmental and other conditions (e.g., safety, weather).
    <bullet> Navy aircraft participating in exercises at sea will 
conduct and maintain, when operationally feasible and safe, 
surveillance for marine species of concern as long as it does not 
violate safety constraints or interfere with the accomplishment of 
primary operational duties.
    <bullet> Marine mammal detections will be immediately reported to 
assigned Aircraft Control Unit for further dissemination to ships in 
the vicinity of the marine species as appropriate where it is 
reasonable to conclude that the course of the ship will likely result 
in a closing of the distance to the detected marine mammal.

Operating Procedures (for Anti-Submarine Warfare Operations)

    <bullet> On the bridge of surface ships, there will always be at 
least three people on watch whose duties include observing the water 
surface around the vessel.
    <bullet> All surface ships participating in ASW training events 
will, in addition to the three personnel on watch noted previously, 
have at all times during the exercise at least two additional personnel 
on watch as lookouts.
    <bullet> Personnel on lookout and officers on watch on the bridge 
will have at least one set of binoculars available for each person to 
aid in the detection of marine mammals.
    <bullet> Personnel on lookout will be responsible for reporting all 
objects or anomalies sighted in the water (regardless of the distance 
from the vessel) to the Officer of the Deck, since any object or 
disturbance (e.g., trash, periscope, surface disturbance, 
discoloration) in the water may be indicative of a threat to the vessel 
and its crew or indicative of a marine species that may need to be 
avoided as warranted.
    <bullet> All personnel engaged in passive acoustic sonar operation 
(including aircraft, surface ships, or submarines) will monitor for 
marine mammal vocalizations and report the detection of any marine 
mammal to the appropriate watch station for dissemination and 
appropriate action.
    <bullet> During MFAS operations, personnel will utilize all 
available sensor and optical systems (such as night vision goggles) to 
aid in the detection of marine mammals.
    <bullet> Aircraft with deployed sonobuoys will use only the passive 
capability of sonobuoys when marine mammals are detected within 200 yds 
(183 m) of the sonobuoy.
    <bullet> Helicopters shall observe/survey the vicinity of an ASW 
exercise for 10 minutes before the first deployment of active (dipping) 
sonar in the water.
    <bullet> Helicopters shall not dip their sonar within 200 yards of 
a marine mammal and shall cease pinging if a marine mammal closes 
within 200 yards after pinging has begun.
    <bullet> Safety Zones--When marine mammals are detected by any 
means (aircraft, shipboard lookout, or acoustically) within or closing 
to inside 1,000 yds (914 m) of the sonar dome (the bow), the ship or 
submarine will limit active transmission levels to at least 6 decibels 
(dB) below normal operating levels (i.e., limit to at most 229 dB for 
AN/SQS-53C and 219 for AN/SQS-56C, etc)
    <bullet> Ships and submarines will continue to limit maximum 
transmission levels by this 6-dB factor until the animal has been seen 
to leave the 1000-yd exclusion zone, has not been detected for 30 
minutes, or the vessel has transited more than 2,000 yds (1829 m) 
beyond the location of the last detection.
    <bullet> Should a marine mammal be detected within or closing to 
inside 500 yds (457 m) of the sonar dome, active sonar transmissions 
will be limited to at least 10 dB below the equipment's normal 
operating level (i.e., limit to at most 225 dB for AN/SQS-53C and 215 
for AN/SQS-56C, etc.). Ships and submarines will continue to limit 
maximum ping levels by this 10-dB

[[Page 53833]]

factor until the animal has been seen to leave the 500-yd area (at 
which point the Navy could return to the 6-dB down powerdown, but not 
full power) or the 1000-yd area, has not been detected for 30 minutes, 
or the vessel has transited more than 2,000 yds (1829 m) beyond the 
location of the last detection.
    <bullet> Should the marine mammal be detected within or closing to 
inside 200 yds (183 m) of the sonar dome, active sonar transmissions 
will cease. Active sonar will not resume until the animal has been seen 
to leave the 200-yd exclusion zone (at which point the 500 or 1000-yd 
powerdowns apply until the animal is beyond the 1000-yd exclusion 
zone), has not been detected for 30 minutes, or the vessel has 
transited more than 2,000 yds (1829 m) beyond the location of the last 
detection.
    <bullet> Special conditions applicable for dolphin and porpoise 
only: If, after conducting an initial maneuver to avoid close quarters 
with dolphin or porpoise, the OOD concludes that dolphins are 
deliberately closing to ride the vessel's bow wave, no further 
mitigation actions would be necessary while the dolphin or porpoise 
continue to exhibit bow wave riding behavior.
    <bullet> If the need for power-down should arise (as detailed in 
``Safety Zones'' above) when the Navy was operating a hull-mounted or 
sub-mounted source above 235 dB (infrequent) the Navy shall follow the 
requirements as though they were operating at 235 dB (i.e., the first 
power-down will be to 229 dB).
    <bullet> Prior to start up or restart of active sonar, operators 
will check that the Safety Zone radius around the sound source is clear 
of marine mammals.
    <bullet> Active sonar levels (generally)--Navy will operate sonar 
at the lowest practicable level, not to exceed 235 dB, except as 
required to meet tactical training objectives.
    <bullet> Submarine sonar operators will review detection indicators 
of close-aboard marine mammals prior to the commencement of ASW 
training events involving MFAS.

Underwater Detonations (Up to 10-lb Charges)

    Exclusion Zones--All training activities involving the use of 
explosive charges must include exclusion zones for marine mammals to 
prevent physical and/or acoustic effects to those species. These 
exclusion zones for demolitions and ship mine countermeasres shall 
extend in a 700-yard arc (640 m) radius around the detonation site. 
Should a marine mammal be present within the the surveillance area, the 
explosive event shall not be started until the animal leaves the area.
    Pre-Exercise Surveys--For Demolition and Ship Mine Countermeasures 
Operations, pre-exercise surveys shall be conducted within 30 minutes 
prior to the commencement of the scheduled explosive event. The survey 
may be conducted from the surface, by divers, and/or from the air, and 
personnel shall be alert to the presence of any marine mammal. Should 
such an animal be present within the exclusion area, the explosive 
event shall be paused until the animal voluntarily leaves the area. The 
Navy will ensure the exclusion area is clear of marine mammals for a 
full 30 minutes prior to initiating the explosive event.
    Post-Exercise Surveys--Surveys within the same radius shall also be 
conducted within 30 minutes after the completion of the explosive 
event.
    Reporting--If there is any evidence that a marine mammal may have 
been injured or killed by the action, Navy training activities shall be 
immediately suspended and the action reported immediately to Commander, 
Navy Marianas who will contact the Commander, Pacific Fleet. The 
situation shall also be reported to NMFS (see Stranding Plan for 
details).

Sinking Exercises

    The selection of sites suitable for SINKEXs involves a balance of 
operational suitability, requirements established under the Marine 
Protection, Research and Sanctuaries Act (MPRSA) permit granted to the 
Navy (40 CFR 229.2), and the identification of areas with a low 
likelihood of encountering ESA-listed species. To meet operational 
suitability criteria, the locations of SINKEXs must be within a 
reasonable distance of the target vessels' originating location. The 
locations should also be close to active military bases to allow 
participating assets access to shore facilities. For safety purposes, 
these locations should also be in areas that are not generally used by 
non-military air or watercraft. The MPRSA permit requires vessels to be 
sunk in waters which are at least 1000 fathoms (1828 m) deep and at 
least 50 nm from land. In general, most listed species prefer areas 
with strong bathymetric gradients and oceanographic fronts for 
significant biological activity such as feeding and reproduction. 
Typical locations include the continental shelf and shelf-edge.
    <bullet> All weapons firing would be conducted during the period 1 
hour after official sunrise to 30 minutes before official sunset.
    <bullet> Extensive range clearance activities would be conducted in 
the hours prior to commencement of the exercise, ensuring that no 
shipping is located within the hazard range of the longest-range weapon 
being fired for that event.
    <bullet> An exclusion zone with a radius of 1.0 nm (1.9 km) would 
be established around each target. This exclusion zone is based on 
calculations using a 990-lb (450-kg) H6 net explosive weight high 
explosive source detonated 5 ft (1.5 m) below the surface of the water, 
which yields a distance of 0.85 nm (1.57 km) (cold season) and 0.89 nm 
(1.65 km) (warm season) beyond which the received level is below the 
182 decibels (dB) re: 1 micropascal squared-seconds ([mu]Pa2-s) 
threshold established for the WINSTON S. CHURCHILL (DDG 81) shock 
trials (U.S. Navy, 2001). An additional buffer of 0.5 nm (0.9 km) would 
be added to account for errors, target drift, and animal movements. 
Additionally, a safety zone, which would extend beyond the buffer zone 
by an additional 0.5 nm (0.9 km), would be surveyed. Together, the 
zones extend out 2 nm (3.7 km) from the target.
    <bullet> A series of surveillance overflights shall be conducted 
prior to the event to determine whether marine mammals are present in 
the exclusion zone. Survey protocol will be as follows:
    <bullet> Overflights within the exclusion zone would be conducted 
in a manner that optimizes the surface area of the water observed. This 
may be accomplished through the use of the Navy's Search and Rescue 
Tactical Aid, which provides the best search altitude, ground speed, 
and track spacing for the discovery of small, possibly dark objects in 
the water based on the environmental conditions of the day. These 
environmental conditions include the angle of sun inclination, amount 
of daylight, cloud cover, visibility, and sea state.
    <bullet> All visual surveillance activities would be conducted by 
Navy personnel trained in visual surveillance. At least one member of 
the mitigation team would have completed the Navy's marine mammal 
training program for lookouts.
    <bullet> In addition to the overflights, the exclusion zone would 
be monitored by passive acoustic means, when assets are available. This 
passive acoustic monitoring would be maintained throughout the 
exercise. Potential assets include sonobuoys, which can be utilized to 
detect any vocalizing marine mammals (particularly sperm whales) in the 
vicinity of the exercise. The sonobuoys would be re-seeded as necessary 
throughout the exercise. Additionally, passive sonar onboard submarines 
may be utilized to detect any vocalizing marine mammals in the area. 
The OCE would be informed of

[[Page 53834]]

any aural detection of marine mammals and would include this 
information in the determination of when it is safe to commence the 
exercise.
    <bullet> On each day of the exercise, aerial surveillance of the 
exclusion and safety zones would commence 2 hours prior to the first 
firing.
    <bullet> The results of all visual, aerial, and acoustic searches 
would be reported immediately to the OCE. No weapons launches or firing 
would commence until the OCE declares the safety and exclusion zones 
free of marine mammals and threatened and endangered species.
    <bullet> If a marine mammal observed within the exclusion zone is 
diving, firing would be delayed until the animal is re-sighted outside 
the exclusion zone, or 30 minutes have elapsed, whichever occurs first. 
After 30 minutes, if the animal has not been re-sighted it would be 
assumed to have left the exclusion zone. The OCE would determine if the 
marine mammal is in danger of being adversely affected by commencement 
of the exercise.
    <bullet> During breaks in the exercise of 30 minutes or more, the 
exclusion zone would again be surveyed for any marine mammal. If a 
marine mammal is sighted within the exclusion zone or the buffer zone, 
the OCE would be notified, and the procedure described above would be 
followed.
    <bullet> Upon sinking of the vessel, a final surveillance of the 
exclusion zone would be monitored for 2 hours, or until sunset, to 
verify that no marine mammals were harmed.
    <bullet> Aerial surveillance would be conducted using helicopters 
or other aircraft based on necessity and availability. The Navy has 
several types of aircraft capable of performing this task; however, not 
all types are available for every exercise. For each exercise, the 
available asset best suited for identifying objects on and near the 
surface of the ocean would be used. These aircraft would be capable of 
flying at the slow safe speeds necessary to enable viewing of marine 
vertebrates with unobstructed, or minimally obstructed, downward and 
outward visibility. The exclusion and safety zone surveys may be 
cancelled in the event that a mechanical problem, emergency search and 
rescue, or other similar and unexpected event preempts the use of one 
of the aircraft onsite for the exercise.
    <bullet> Every attempt would be made to conduct the exercise in sea 
states that are ideal for marine mammal sighting--Beaufort Sea State 3 
or less. In the event of a sea state of 4 or above, survey efforts 
would be increased within the zones. This would be accomplished through 
the use of an additional aircraft, if available, and conducting tight 
search patterns.
    <bullet> The exercise would not be conducted unless the exclusion 
zone or buffer zone could be adequately monitored visually. Should low 
cloud cover or surface visibility prevent adequate visual monitoring as 
described previously, the exercise would be delayed until conditions 
improved, and all of the above monitoring criteria could be met.
    <bullet> In the unlikely event that any marine mammal is observed 
to be harmed in the area, a detailed description of the animal would be 
taken, the location noted, and if possible, photos taken. This 
information would be provided to NMFS via the Navy's regional 
environmental coordinator for purposes of identification (see the draft 
Stranding Plan for detail).
    <bullet> An after action report detailing the exercise's time line, 
the time the surveys commenced and terminated, amount, and types of all 
ordnance expended, and the results of survey efforts for each event 
would be submitted to NMFS.

Surface-to-Surface Gunnery (Up to 5-Inch Explosive Rounds)

    <bullet> For exercises using targets towed by a vessel, target-
towing vessels shall maintain a trained lookout for marine mammals when 
feasible. If a marine mammal is sighted in the vicinity, the tow vessel 
will immediately notify the firing vessel, which will suspend the 
exercise until the area is clear.
    <bullet> A 600 yard (585 m) radius buffer zone will be established 
around the intended target.
    <bullet> From the intended firing position, trained lookouts will 
survey the buffer zone for marine mammals and sea turtles prior to 
commencement and during the exercise as long as practicable. Due to the 
distance between the firing position and the buffer zone, lookouts are 
only expected to visually detect breaching whales, whale blows, and 
large pods of dolphins and porpoises.
    <bullet> The exercise will be conducted only when the buffer zone 
is visible and marine mammals are not detected within it.

Surface-to-Surface Gunnery (Non-Explosive Rounds)

    <bullet> A 200 yard (183 m) radius buffer zone will be established 
around the intended target.
    <bullet> From the intended firing position, trained lookouts will 
survey the buffer zone for marine mammals and sea turtles prior to 
commencement and during the exercise as long as practicable. Due to the 
distance between the firing position and the buffer zone, lookouts are 
only expected to visually detect breaching whales, whale blows, and 
large pods of dolphins and porpoises.
    <bullet> If applicable, target towing vessels will maintain a 
lookout. If a marine mammal or sea turtle is sighted in the vicinity of 
the exercise, the tow vessel will immediately notify the firing vessel 
in order to secure gunnery firing until the area is clear.
    <bullet> The exercise will be conducted only when the buffer zone 
is visible and marine mammals and sea turtles are not detected within 
the target area and the buffer zone.

Surface-to-Air Gunnery (Explosive and Non-Explosive Rounds)

    <bullet> Vessels will orient the geometry of gunnery exercises in 
order to prevent debris from falling in the area of sighted marine 
mammals and sea turtles.
    <bullet> Vessels will expedite the attempt to recover any parachute 
deploying aerial targets to reduce the potential for entanglement of 
marine mammals and sea turtles.
    <bullet> Target towing aircraft shall maintain a lookout if 
feasible. If a marine mammal or sea turtle is sighted in the vicinity 
of the exercise, the tow aircraft will immediately notify the firing 
vessel in order to secure gunnery firing until the area is clear.

Air-to-Surface Gunnery (Explosive and Non-Explosive Rounds)

    <bullet> A 200 yard (183 m) radius buffer zone will be established 
around the intended target.
    <bullet> If surface vessels are involved, lookout(s) will visually 
survey the buffer zone for marine mammals and sea turtles prior to and 
during the exercise.
    <bullet> Aerial surveillance of the buffer zone for marine mammals 
and sea turtles will be conducted prior to commencement of the 
exercise. Aerial surveillance altitude of 500 feet to 1,500 feet (152-
456 m) is optimum. Aircraft crew/pilot will maintain visual watch 
during exercises. Release of ordnance through cloud cover is 
prohibited; aircraft must be able to actually see ordnance impact 
areas.
    <bullet> The exercise will be conducted only if marine mammals and 
sea turtles are not visible within the buffer zone.

Small Arms Training (Grenades, Explosive and Non-Explosive Rounds)

    Lookouts will visually survey for marine mammals and sea turtles. 
Weapons will not be fired in the

[[Page 53835]]

direction of known or observed marine mammals or sea turtles.

Air-to-Surface At-Sea Bombing Exercises (Explosive Bombs and Rockets)

    <bullet> Ordnance shall not be targeted to impact within 1,000 
yards (914 m) of known or observed sea turtles or marine mammals.
    <bullet> A buffer zone of 1,000 yards (914 m) radius will be 
established around the intended target.
    <bullet> Aircraft will visually survey the target and buffer zone 
for marine mammals and sea turtles prior to and during the exercise. 
The survey of the impact area will be made by flying at 1,500 feet or 
lower, if safe to do so, and at the slowest safe speed. When safety or 
other considerations require the release of weapons without the 
releasing pilot having visual sight of the target area, a second 
aircraft, the ``wingman,'' will clear the target area and perform the 
clearance and observation functions required before the dropping plane 
may release its weapons. Both planes must have direct communication to 
assure immediate notification to the dropping plane that the target 
area may have been fouled by encroaching animals or people. The 
clearing aircraft will assure it has visual site of the target area at 
a maximum height of 1500 ft. The clearing plane will remain within 
visual sight of the target until required to clear the area for safety 
reasons.
    <bullet> Survey aircraft should employ most effective search 
tactics and capabilities.
    <bullet> The exercises will be conducted only if marine mammals and 
sea turtles are not visible within the buffer zone.

Air-to-Surface At-Sea Bombing Exercises (Non-Explosive Bombs and 
Rockets)

    <bullet> If surface vessels are involved, trained lookouts will 
survey for sea turtles and marine mammals. Ordnance shall not be 
targeted to impact within 1,000 yards (914 m) of known or observed sea 
turtles or marine mammals.
    <bullet> A 1,000 yard (914 m) radius buffer zone will be 
established around the intended target.
    <bullet> Aircraft will visually survey the target and buffer zone 
for marine mammals and sea turtles prior to and during the exercise. 
The survey of the impact area will be made by flying at 1,500 feet (152 
m) or lower, if safe to do so, and at the slowest safe speed. When 
safety or other considerations require the release of weapons without 
the releasing pilot having visual sight of the target area, a second 
aircraft, the ``wingman,'' will clear the target area and perform the 
clearance and observation functions required before the dropping plane 
may release its weapons. Both planes must have direct communication to 
assure immediate notification to the dropping plane that the target 
area may have been fouled by encroaching animals or people. The 
clearing aircraft will assure it has visual site of the target area at 
a maximum height of 1500 ft. The clearing plane will remain within 
visual sight of the target until required to clear the area for safety 
reasons. Survey aircraft shall employ most effective search tactics and 
capabilities.
    <bullet> The exercise will be conducted only if marine mammals and 
sea turtles are not visible within the buffer zone.
    Air-to-Surface Missile Exercises (explosive and non-explosive)--
Aircraft will visually survey the target area for marine mammals. 
Visual inspection of the target area will be made by flying at 1,500 
(457 m) feet or lower, if safe to do so, and at slowest safe speed. 
Firing or range clearance aircraft must be able to actually see 
ordnance impact areas. Explosive ordnance shall not be targeted to 
impact within 1,800 yds (1646 m) of sighted marine mammals.

Aircraft Training Activities Involving Non-Explosive Devices

    Non-explosive devices such as some sonobuoys, inert bombs, and 
Mining Training Activities involve aerial drops of devices that have 
the potential to hit marine mammals and sea turtles if they are in the 
immediate vicinity of a floating target. The exclusion zone, as 
established above for each non-explosive exercise type and if not-
defined above, the minimum exclusion zone is 200 yards, shall be clear 
of marine mammals and sea turtles around the target location. Pre- and 
post-surveillance and reporting requirements outlined for underwater 
detonations shall be implemented during Mining Training Activities.

Explosive Source Sonobuoys Used in EER/IEER (AN/SSQ-110A)

    <bullet> Crews will conduct visual reconnaissance of the drop area 
prior to laying their intended sonobuoy pattern. This search should be 
conducted below 457 m (500 yd) at a slow speed, if operationally 
feasible and weather conditions permit. In dual aircraft operations, 
crews are allowed to conduct coordinated area clearances.
    <bullet> Crews shall conduct a minimum of 30 minutes of visual and 
aural monitoring of the search area prior to commanding the first post 
detonation. This 30-minute observation period may include pattern 
deployment time.
    <bullet> For any part of the briefed pattern where a post (source/
receiver sonobuoy pair) will be deployed within 914 m (1,000 yd) of 
observed marine mammal activity, deploy the receiver only and monitor 
while conducting a visual search. When marine mammals are no longer 
detected within 914 m (1,000 yd) of the intended post position, co-
locate the explosive source sonobuoy (AN/SSQ-110A) (source) with the 
receiver.
    <bullet> When operationally feasible, crews will conduct continuous 
visual and aural monitoring of marine mammal activity. This is to 
include monitoring of own-aircraft sensors from first sensor placement 
to checking off station and out of RF range of these sensors.
    <bullet> Aural Detection--If the presence of marine mammals is 
detected aurally, then that should cue the aircrew to increase the 
diligence of their visual surveillance. Subsequently, if no marine 
mammals are visually detected, then the crew may continue multi-static 
active search.
    <bullet> Visual Detection--If marine mammals are visually detected 
within 914 m (1,000 yd) of the explosive source sonobuoy (AN/SSQ-110A) 
intended for use, then that payload shall not be detonated. Aircrews 
may utilize this post once the marine mammals have not been re-sighted 
for 30 minutes, or are observed to have moved outside the 914 m (1,000 
yd) safety buffer, whichever occurs first. Aircrews may shift their 
multi-static active search to another post, where marine mammals are 
outside the 914 m (1,000 yd) safety buffer.
    <bullet> Aircrews shall make every attempt to manually detonate the 
unexploded charges at each post in the pattern prior to departing the 
operations area by using the ``Payload 1 Release'' command followed by 
the ``Payload 2 Release'' command. Aircrews shall refrain from using 
the ``Scuttle'' command when two payloads remain at a given post. 
Aircrews will ensure that a 914 m (1,000 yd) safety buffer, visually 
clear of marine mammals, is maintained around each post as is done 
during active search training activities.
    <bullet> Aircrews shall only leave posts with unexploded charges in 
the event of a sonobuoy malfunction, an aircraft system malfunction, or 
when an aircraft must immediately depart the area due to issues such as 
fuel constraints, inclement weather, and in-flight emergencies. In 
these cases, the sonobuoy will self-scuttle using the secondary 
(detonation occurs by timer approximately 6 hours after water entry) or 
tertiary (detonation occurs by salt water soluble plug approximately 12 
hours after water entry) method.

[[Page 53836]]

    <bullet> Aircrews shall ensure all payloads are accounted for. 
Explosive source sonobuoys (AN/SSQ-110A) that cannot be scuttled shall 
be reported as unexploded ordnance via voice communications while 
airborne, then upon landing via naval message.
    <bullet> Mammal monitoring shall continue until out of own-aircraft 
sensor range.

Stranding Response Plan for MIRC

    NMFS and the Navy have developed a draft Stranding Response Plan 
for Major Exercises in the MIRC Study Area (available at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm). Pursuant to 50 CFR 
216.105, the plan will be included as part of (attached to) the Navy's 
MMPA Letter of Authorization (LOA), which contains the conditions under 
which the Navy is authorized to take marine mammals pursuant to 
training activities in the MIRC Study Area. The Stranding Response plan 
is specifically intended to outline the applicable requirements the 
authorization is conditioned upon in the event that a marine mammal 
stranding is reported in the MIRC Study Area during a major training 
exercise (MTE) (see glossary below). NMFS considers all plausible 
causes within the course of a stranding investigation and this plan in 
no way presumes that any strandings in the MIRC Study Area are related 
to, or caused by, Navy training activities, absent a determination made 
in a Phase 2 Investigation, as outlined in Paragraph 7 of this plan, 
indicating that MFAS or explosive detonation in the MIRC Study Area 
were a cause of the stranding. This plan is designed to address the 
following three issues:
    <bullet> Mitigation--When marine mammals are in a situation that 
can be defined as a stranding (see glossary of plan), they are 
experiencing physiological stress. When animals are stranded, and 
alive, NMFS believes that exposing these compromised animals to 
additional known stressors would likely exacerbate the animal's 
distress and could potentially cause its death. Regardless of the 
factor(s) that may have initially contributed to the stranding, it is 
NMFS' goal to avoid exposing these animals to further stressors. 
Therefore, when live stranded cetaceans are in the water and engaged in 
what is classified as an Uncommon Stranding Event (USE) (see glossary 
of plan), the shutdown component of this plan is intended to minimize 
the exposure of those animals to MFAS and explosive detonations, 
regardless of whether or not these activities may have initially played 
a role in the event.
    <bullet> Monitoring--This plan will enhance the understanding of 
how MFAS/HFAS or IEER (as well as other environmental conditions) may, 
or may not, be associated with marine mammal injury or strandings. 
Additionally, information gained from the investigations associated 
with this plan may be used in the adaptive management of mitigation or 
monitoring measures in subsequent LOAs, if appropriate.
    <bullet> Compliance--The information gathered pursuant to this 
protocol will inform NMFS' decisions regarding compliance with Sections 
101(a)(5)(B) and (C) of the MMPA.
    The Stranding Response Plan has several components:
    Shutdown Procedures--When an uncommon stranding event (USE--defined 
in the plan) occurs during a major exercise in the MIRC Study Area, and 
a live cetacean(s) is in the water exhibiting indicators of distress 
(defined in the plan), NMFS will advise the Navy that they should cease 
MFAS/HFAS operation and explosive detonations within 14 nm of the live 
animal involved in the USE (NMFS and Navy will maintain a dialogue, as 
needed, regarding the identification of the USE and the potential need 
to implement shutdown procedures). This distance is the approximate 
distance at which sounds from the sonar sources are anticipated to 
attenuate to 145 dB (SPL). The risk function predicts that less than 1 
percent of the animals exposed to sonar at this level (mysticete or 
odontocete) would respond in a manner that NMFS considers Level B 
Harassment.
    Memorandum of Agreement (MOA)--The Navy and NMFS will develop an 
MOA, or other mechanism consistent with federal fiscal law requirements 
(and all other applicable laws), that allows the Navy to assist NMFS 
with the Phase 1 and 2 Investigations of USEs through the provision of 
in-kind services, such as (but not limited to) the use of plane/boat/
truck for transport of stranding responders or animals, use of Navy 
property for necropsies or burial, or assistance with aerial surveys to 
discern the extent of a USE. The Navy may assist NMFS with the 
investigations by providing one or more of the in-kind services 
outlined in the MOA, when available and logistically feasible and when 
the provision does not negatively affect Fleet operational commitments.
    Communication Protocol--Effective communication is critical to the 
successful implementation of this Stranding Response Plan. Very 
specific protocols for communication, including identification of the 
Navy personnel authorized to implement a shutdown and the NMFS 
personnel authorized to advise the Navy of the need to implement 
shutdown procedures and the associated phone trees, etc. are currently 
in development and will be refined and finalized for the Stranding 
Response Plan prior to the issuance of a final rule (and updated 
yearly).
    Stranding Investigation--The Stranding Response Plan also outlines 
the way that NMFS plans to investigate any strandings (providing staff 
and resources are available) that occur during major training exercises 
in the MIRC.

Mitigation Conclusions

    NMFS has carefully evaluated the Navy's proposed mitigation 
measures and considered a broad range of other measures in the context 
of ensuring that NMFS prescribes the means of effecting the least 
practicable adverse impact on the affected marine mammal species and 
stocks and their habitat. Our evaluation of potential measures included 
consideration of the following factors in relation to one another:
    <bullet> The manner in which, and the degree to which, the 
successful implementation of the measure is expected to minimize 
adverse impacts to marine mammals,
    <bullet> The proven or likely efficacy of the specific measure to 
minimize adverse impacts as planned,
    <bullet> The practicability of the measure for applicant 
implementation, including consideration of personnel safety, 
practicality of implementation, and impact on the effectiveness of the 
military readiness activity.
    In some cases, additional mitigation measures are required beyond 
those that the applicant proposes. Any mitigation measure(s) prescribed 
by NMFS should be able to accomplish, have a reasonable likelihood of 
accomplishing (based on current science), or contribute to the 
accomplishment of one or more of the general goals listed below:
    (a) Avoidance or minimization of injury or death of marine mammals 
wherever possible (goals b, c, and d may contribute to this goal).
    (b) A reduction in the numbers of marine mammals (total number or 
number at biologically important time or location) exposed to received 
levels of MFAS/HFAS, underwater detonations, or other activities 
expected to result in the take of marine mammals (this goal may 
contribute to a, above, or to reducing harassment takes only).
    (c) A reduction in the number of times (total number or number at 
biologically important time or location) individuals would be exposed 
to received levels of MFAS/HFAS, underwater detonations,

[[Page 53837]]

or other activities expected to result in the take of marine mammals 
(this goal may contribute to a, above, or to reducing harassment takes 
only).
    (d) A reduction in the intensity of exposures (either total number 
or number at biologically important time or location) to received 
levels of MFAS/HFAS, underwater detonations, or other activities 
expected to result in the take of marine mammals (this goal may 
contribute to a, above, or to reducing the severity of harassment takes 
only).
    (e) Avoidance or minimization of adverse effects to marine mammal 
habitat, paying special attention to the food base, activities that 
block or limit passage to or from biologically important areas, 
permanent destruction of habitat, or temporary destruction/disturbance 
of habitat during a biologically important time.
    (f) For monitoring directly related to mitigation--an increase in 
the probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation (shut-down zone, etc.).
    Based on our evaluation of the Navy's proposed measures, as well as 
other measures considered by NMFS or recommended by the public, NMFS 
has determined preliminarily that the Navy's proposed mitigation 
measures (especially when the Adaptive Management component is taken 
into consideration (see Adaptive Management below)) are adequate means 
of effecting the least practicable adverse impacts on marine mammals 
species or stocks and their habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, while 
also considering personnel safety, practicality of implementation, and 
impact on the effectiveness of the military readiness activity. Further 
detail is included below.
    The proposed rule comment period will afford the public an 
opportunity to submit recommendations, views and/or concerns regarding 
this action and the proposed mitigation measures. While NMFS has 
determined preliminarily that the Navy's proposed mitigation measures 
will effect the least practicable adverse impact on the affected 
species or stocks and their habitat, NMFS will consider all public 
comments to help inform our final decision. Consequently, the proposed 
mitigation measures may be refined, modified, removed, or added to 
prior to the issuance of the final rule based on public comments 
received, and where appropriate, further analysis of any additional 
mitigation measures.
    NMFS believes that the range clearance procedures and shutdown/
safety zone/exclusion zone measures the Navy has proposed will enable 
the Navy to avoid injuring marine mammals and will enable them to 
minimize the numbers of marine mammals exposed to levels associated 
with TTS for the following reasons:

MFAS/HFAS

    The Navy's standard protective measures indicate that they will 
ensure powerdown of MFAS/HFAS by 6-dB when a marine mammal is detected 
within 1000 yd (914 m), powerdown of 4 more dB (or 10-dB total) when a 
marine mammal is detected within 500 yd (457 m), and will cease MFAS/
HFAS transmissions when a marine mammal is detected within 200 yd (183 
m).
    PTS/Injury--NMFS believes that the proposed mitigation measures 
will allow the Navy to avoid exposing marine mammals to received levels 
of MFAS/HFAS sound that would result in injury for the following 
reasons:
    <bullet> The estimated distance from the most powerful source at 
which cetaceans would receive levels at or above the threshold for PTS/
injury/Level A Harassment is approximately 10 m (10.9 yd).
    <bullet> NMFS believes that the probability that a marine mammal 
would approach within the above distances of the sonar dome (to the 
sides or below) without being seen by the watchstanders (who would then 
activate a shutdown if the animal was within 200 yd (183 m)) is very 
low, especially considering that animals would likely avoid approaching 
a source transmitting at that level at that distance.
    <bullet> The model predicted that one pantropical dolphin and one 
sperm whale would be exposed to levels associated with injury, however, 
the model does not consider the mitigation or likely avoidance 
behaviors and NMFS believes that injury is unlikely when those factors 
are considered.
    TTS--NMFS believes that the proposed mitigation measures will allow 
the Navy to minimize exposure of marine mammals to received levels of 
MFAS/HFAS sound associated with TTS for the following reasons:
    <bullet> The estimated maximum distance from the most powerful 
source at which cetaceans would receive levels at or above the 
threshold for TTS is approximately 140 m from the source in most 
operating environments.
    <bullet> Based on the size of the animals, average group size, 
behavior, and average dive time, NMFS believes that the probability 
that Navy watchstanders will visually detect mysticetes or sperm 
whales, dolphins, and social pelagic species (pilot whales, melon-
headed whales, etc.) at some point within the 1000 yd (914 km) safety 
zone before they are exposed to the TTS threshold levels is high, which 
means that the Navy would often be able to shutdown or powerdown to 
avoid exposing these species to sound levels associated with TTS.
    <bullet> However, more cryptic animals that are difficult to detect 
and observe, such as deep-diving cetaceans (beaked whales and Kogia 
spp.), are less likely to be visually detected and could potentially be 
exposed to levels of MFAS/HFAS expected to cause TTS. However, animals 
at depth in one location would not be expected to be continuously 
exposed to repeated sonar signals given the typical 10-14 knot speed of 
Navy surface ships during ASW events. During a typical one-hour 
subsurface dive by a beaked whale, the ship will have moved over 5 to 
10 nm from the original location.
    <bullet> Additionally, the Navy's bow-riding mitigation exception 
for dolphins may sometimes result in dolphins being exposed to levels 
of MFAS/HFAS likely to result in TTS. However, there are combinations 
of factors that reduce the acoustic energy received by dolphins 
approaching ships to ride in bow waves. Dolphins riding a ship's bow 
wave are outside of the main beam of the MFAS vertical beam pattern. 
Source levels drop quickly outside of the main beam. Sidelobes of the 
radiate beam pattern that point to the surface are significantly lower 
in power. Together with spherical spreading losses, received levels in 
the ship's bow wave can be more than 42 dB less than typical source 
level (i.e., 235 dB - 42 dB = 193 dB SPL). Finally, bow wave riding 
dolphins are frequently in and out of a bubble layer generated by the 
breaking bow waves. This bubble layer is an excellent scatterer of 
acoustic energy and can further reduce received energy.
    The Stranding Response Plan will minimize the probability of 
distressed live-stranded animals responding to the proximity of sonar 
in a manner that further stresses them or increases the potential 
likelihood of mortality.

Underwater Explosives

    The Navy utilizes exclusion zones (wherein explosive detonation 
will not begin/continue if animals are within the zone) for explosive 
exercises. Table 3 identifies the various explosives, the estimated 
distance at which animals will receive levels associated with take (see 
Acoustic Take Criteria Section), and the exclusion zone associated with 
the explosive types.
    Mortality and Injury--NMFS believes that the mitigation measures 
will allow

[[Page 53838]]

the Navy to avoid exposing marine mammals to underwater detonations 
that would result in injury or mortality for the following reasons:
    <bullet> Surveillance for large charges (which includes aerial and 
passive acoustic detection methods, when available, to ensure 
clearance) begins two hours before the exercise and extends to 2 nm 
(3704 m) from the source. Surveillance for all charges extends out 3-50 
times the farthest distance from the source at which injury would be 
anticipated to occur (see Table 3).
    <bullet> Animals would need to be less than 426 m (465 yd) (large 
explosives) or 8-160 m (9-175 yd) (smaller charges) from the source to 
be injured.
    <bullet> Unlike for active sonar, an animal would need to be 
present at the exact moment of the explosion(s) (except for the short 
series of gunfire example in GUNEX) to be taken.
    <bullet> The model predicted that 0 animals would be exposed to 
explosive levels associated with injury or death.
    <bullet> When the implementation of the exclusion zones (i.e., the 
fact that the Navy will not start a detonation or will not continue to 
detonate explosives if an animal is detected within the exclusion zone) 
is considered in combination with the factors described in the above 
bullets, NMFS believes that the Navy's mitigation will prevent injury 
and mortality to marine mammals from explosives.
    TTS--NMFS believes that the proposed mitigation measures will allow 
the Navy to minimize the exposure of marine mammals to underwater 
detonations that would result in TTS for the following reasons:
    <bullet> 43 animals annually were predicted to be exposed to 
explosive levels that would result in TTS. For the reasons explained 
above, NMFS believes that most modeled TTS takes can be avoided, 
especially dolphins, mysticetes and sperm whales, and social pelagic 
species.
    <bullet> However, more cryptic, deep-diving species (beaked whales 
and Kogia spp.) are less likely to be visually detected and could 
potentially be exposed to explosive levels expected to cause TTS. The 
model estimated that 4 beaked whales and zero Kogia would be exposed to 
TTS levels.
    <bullet> Additionally, for SINKEXs, the distance at which an animal 
would be expected to receive sound or pressure levels associated with 
TTS (182 dB SEL or 23 psi) is sometimes (when the largest explosive 
type, the MK-84, is used) larger than the exclusion zone, which means 
that for those two exercise types, some individuals will likely be 
exposed to levels associated with TTS outside of the exclusion zone.

Research

    The Navy provides a significant amount of funding and support to 
marine research. In the past five years the agency funded over $100 
million ($26 million in FY08 alone) to universities, research 
institutions, federal laboratories, private companies, and independent 
researchers around the world to study marine mammals. The U.S. Navy 
sponsors 70% of all U.S. research concerning the effects of human-
generated sound on marine mammals and 50% of such research conducted 
worldwide. Major topics of Navy-supported research include the 
following:
    <bullet> Better understanding of marine species distribution and 
important habitat areas,
    <bullet> Developing methods to detect and monitor marine species 
before and during training,
    <bullet> Understanding the effects of sound on marine mammals, sea 
turtles, fish, and birds, and
    <bullet> Developing tools to model and estimate potential effects 
of sound.
    This research is directly applicable to Fleet training activities, 
particularly with respect to the investigations of the potential 
effects of underwater noise sources on marine mammals and other 
protected species. Proposed training activities employ active sonar and 
underwater explosives, which introduce sound into the marine 
environment.
    The Marine Life Sciences Division of the Office of Naval Research 
currently coordinates six programs that examine the marine environment 
and are devoted solely to studying the effects of noise and/or the 
implementation of technology tools that will assist the Navy in 
studying and tracking marine mammals. The six programs are as follows:
    <bullet> Environmental Consequences of Underwater Sound,
    <bullet> Non-Auditory Biological Effects of Sound on Marine 
Mammals,
    <bullet> Effects of Sound on the Marine Environment,
    <bullet> Sensors and Models for Marine Environmental Monitoring,
    <bullet> Effects of Sound on Hearing of Marine Animals, and
    <bullet> Passive Acoustic Detection, Classification, and Tracking 
of Marine Mammals.
    The Navy has also developed the technical reports referenced within 
this document, which include the Marine Resource Assessments and the 
Marine Mammal and sea turtle density estimates for Guam and the CNMI 
(DoN 2007). Furthermore, research cruises by the National Marine 
Fisheries Service (NMFS) and by academic institutions have received 
funding from the U.S. Navy.
    The Navy has sponsored several workshops to evaluate the current 
state of knowledge and potential for future acoustic monitoring of 
marine mammals. The workshops brought together acoustic experts and 
marine biologists from the Navy and other research organizations to 
present data and information on current acoustic monitoring research 
efforts and to evaluate the potential for incorporating similar 
technology and methods on instrumented ranges. However, acoustic 
detection, identification, localization, and tracking of individual 
animals still requires a significant amount of research effort to be 
considered a reliable method for marine mammal monitoring. The Navy 
supports research efforts on acoustic monitoring and will continue to 
investigate the feasibility of passive acoustics as a potential 
mitigation and monitoring tool.
    Overall, the Navy will continue to fund ongoing marine mammal 
research, and is planning to coordinate long-term monitoring/studies of 
marine mammals on various established ranges and operating areas. The 
Navy will continue to research and contribute to university/external 
research to improve the state of the science regarding marine species 
biology and acoustic effects. These efforts include mitigation and 
monitoring programs; data sharing with NMFS and via the literature for 
research and development efforts; and future research as described 
previously.

Long-Term Prospective Study

    Apart from this proposed rule, NMFS, with input and assistance from 
the Navy and several other agencies and entities, will perform a 
longitudinal observational study of marine mammal strandings to 
systematically observe and record the types of pathologies and diseases 
and investigate the relationship with potential causal factors (e.g., 
active sonar, seismic, weather). The study will not be a true 
``cohort'' study, because we will be unable to quantify or estimate 
specific active sonar or other sound exposures for individual animals 
that strand. However, a cross-sectional or correlational analyses, a 
method of descriptive rather than analytical epidemiology, can be 
conducted to compare population characteristics, e.g., frequency of 
strandings and types of specific pathologies between general periods of 
various anthropogenic activities and non-activities within a prescribed 
geographic space. In the

[[Page 53839]]

long-term study, we will more fully and consistently collect and 
analyze data on the demographics of strandings in specific locations 
and consider anthropogenic activities and physical, chemical, and 
biological environmental parameters. This approach in conjunction with 
true cohort studies (tagging animals, measuring received sounds, and 
evaluating behavior or injuries) in the presence of activities and non-
activities will provide critical information needed to further define 
the impacts of MTEs and other anthropogenic and non-anthropogenic 
stressors. In coordination with the Navy and other Federal and non-
federal partners, the comparative study will be designed and conducted 
for specific sites during intervals of the presence of anthropogenic 
activities such as active sonar transmission or other sound exposures 
and absence to evaluate demographics of morbidity and mortality, 
lesions found, and cause of death or stranding. Additional data that 
will be collected and analyzed in an effort to control potential 
confounding factors include variables such as average sea temperature 
(or just season), meteorological or other environmental variables 
(e.g., seismic activity), fishing activities, etc. All efforts will be 
made to include appropriate controls (i.e., no active sonar or no 
seismic); environmental variables may complicate the interpretation of 
``control'' measurements. The Navy and NMFS along with other partners 
are evaluating mechanisms for funding this study.

Monitoring

    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''. 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:
    (a) An increase in our understanding of how many marine mammals are 
likely to be exposed to levels of MFAS/HFAS (or explosives or other 
stimuli) that we associate with specific adverse effects, such as 
behavioral harassment, TTS, or PTS.
    (b) An increase in our understanding of how individual marine 
mammals respond (behaviorally or physiologically) to MFAS/HFAS (at 
specific received levels), explosives, or other stimuli expected to 
result in take.
    (c) An increase in our understanding of how anticipated takes of 
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).
    (d) An increased knowledge of the affected species,
    (e) An increase in our understanding of the effectiveness of 
certain mitigation and monitoring measures,
    (f) A better understanding and record of the manner in which the 
authorized entity complies with the incidental take authorization,
    (g) An increase in the probability of detecting marine mammals, 
both within the safety zone (thus allowing for more effective 
implementation of the mitigation) and in general to better achieve the 
above goals.

Proposed Monitoring Plan for the MIRC

    The Navy has submitted a draft Monitoring Plan for the MIRC which 
may be viewed at NMFS' Web site: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. The plan may be modified or supplemented 
based on comments or new information received from the public during 
the public comment period. A summary of the primary components of the 
plan follows.
    The draft Monitoring Plan for MIRC has been designed as a 
collection of focused ``studies'' (described fully in the MIRC draft 
Monitoring Plan) to gather data that will allow the Navy to address the 
following questions:
    (a) Are marine mammals exposed to MFAS/HFAS, especially at levels 
associated with adverse effects (i.e., based on NMFS' criteria for 
behavioral harassment, TTS, or PTS)? If so, at what levels are they 
exposed?
    (b) If marine mammals are exposed to MFAS/HFAS in the MIRC Range 
Complex, do they redistribute geographically as a result of continued 
exposure? If so, how long does the redistribution last?
    (c) If marine mammals are exposed to MFAS/HFAS, what are their 
behavioral responses to various levels?
    (d) What are the behavioral responses of marine mammals that are 
exposed to explosives at specific levels?
    (e) Is the Navy's suite of mitigation measures for MFAS/HFAS (e.g., 
measures agreed to by the Navy through permitting) effective at 
preventing TTS, injury, and mortality of marine mammals?
    Data gathered in these studies will be collected by qualified, 
professional marine mammal biologists that are experts in their field. 
They will use a combination of the following methods to collect data:

    <bullet> Contracted third party vessel surveys.
    <bullet> Passive acoustic monitoring.
    <bullet> Marine mammal observers on Navy ships.
    <bullet> Shore-based monitoring.

    In the four proposed study designs (all of which cover multiple 
years), the above methods will be used separately or in combination to 
monitor marine mammals in different combinations before, during, and 
after training activities utilizing MFAS/HFAS.
    This monitoring plan has been designed to gather data on all 
species of marine mammals that are observed in the MIRC, however, where 
appropriate priority will be given to ESA-listed species, beaked whales 
and other deep-diving species (Kogia, melon-headed whales, and false-
killer whales). The Plan recognizes that deep-diving and cryptic 
species of marine mammals such as beaked whales have a low probability 
of detection (Barlow and Gisiner, 2006). Therefore, methods will be 
utilized to attempt to address this issue (e.g., passive acoustic 
monitoring).
    In addition to the Monitoring Plan for MIRC, by the end of 2009, 
the Navy will have completed an Integrated Comprehensive Monitoring 
Program (ICMP) Plan. The ICMP will provide the overarching structure 
and coordination that will, over time, compile data from both range 
specific monitoring plans (such as AFAST, the Hawaii Range Complex, the 
Southern California Range Complex, and the Northwest Training Range 
Complex) as well as Navy funded research and development (R&D) studies. 
The primary objectives of the ICMP are to:
    <bullet> Coordinate monitoring and assessment of the effects of 
Navy activities on protected species;
    <bullet> Ensure data collected at multiple locations is collected 
in a manner that allows comparison between and among different 
geographic locations;
    <bullet> Assess the efficacy and practicability of monitoring and 
mitigation techniques; and
    <bullet> Add to the overall knowledge base on potential behavioral 
and physiological effects to marine species from Navy activities.
    More information about the ICMP may be found in the draft 
Monitoring Plan for MIRC.

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Monitoring Workshop

    The Navy, with guidance and support from NMFS, will convene a 
Monitoring Workshop, including marine mammal and acoustic experts as 
well as other interested parties, in 2011. The Monitoring Workshop 
participants will review the monitoring results from the first two 
years of monitoring pursuant to this MIRC rule as well as monitoring 
results from other Navy rules and LOAs (e.g., the Southern California 
Range Complex (SOCAL), Hawaii Range Complex (HRC), etc.). The 
Monitoring Workshop participants would provide their individual 
recommendations to the Navy and NMFS on the monitoring plan(s) after 
also considering the current science (including Navy research and 
development) and working within the framework of available resources 
and feasibility of implementation. NMFS and the Navy would then analyze 
the input from the Monitoring Workshop participants and determine the 
best way forward from a national perspective. Subsequent to the 
Monitoring Workshop, modifications would be applied to monitoring plans 
as appropriate.

Past Monitoring in the MIRC Study Area

    NMFS has received one monitoring report addressing MFAS use in the 
MIRC. The data contained in the After Action Report (AAR) have been 
considered in developing mitigation and monitoring measures for the 
proposed activities contained in this rule. The Navy's AAR may be 
viewed at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm. NMFS has 
reviewed this report and has summarized the results, as related to 
marine mammal observations, below.

Valiant Shield 07

    Valiant Shield 07 (VS 07) was conducted from August 6, 2007 through 
August 13, 2007. The ASW training conducted during the VS 07 involved 
ships, submarines, aircraft, non-explosive exercise weapons, and other 
training related devices and occurred in the Western Pacific ocean 
waters south of the Mariana Islands portion of the MIRC (see Figure A-
1, Appendix A). MFAS-equipped platforms participating in VS07 include 
Ticonderoga-class guided missile cruisers (CG), and Arleigh Burke-class 
guided missile destroyers (DDG) surface combatants with AN/SQS-53C 
sonar, and associated aviation assets (SH-60B/F/R with AN/AQS-13F or 
AQS-22 dipping sonar, and AN/SSQ-62B/C/D/E Directional Command 
Activated Sonobuoy System--DICASS), and P-3 Maritime Patrol Aircraft 
(MPA) (DICASS sonobuoy).
    During VS07, 1,208 hours of MFAS time was reported from all sources 
including hull-mounted 53C, helicopter dipping sonar, and DICASS 
sonobuoys.
    Table A-2 contains a complete list of VS07 marine mammal visual 
sightings made by U.S. Navy lookouts and watch teams based on 
standardized reporting protocols. There were a total of 25 marine 
mammal sightings for an estimated 235 animals during VS07. As in other 
U.S. Navy exercise after action reports, the majority of animals 
sighted were dolphins and porpoises since these species often occur in 
large schools. For VS07, this was again true with six dolphin sightings 
accounting for 196 animals or 83% of the total estimated number of 
animals (196 of 235).
    None of the watchstanders reported any sort of ``observed effect'' 
on the marine mammals that were observed in the ten instances when the 
sonar was on.

Post-Exercise Aerial Marine Mammal Survey

    Immediately following the exercise, an aerial marine mammal survey 
was conducted from 13-17 August 2007. This effort represents one of the 
first summer time marine mammal surveys for the waters south of the 
Marianas, and was conducted by experienced, independent civilian 
scientists and crew using NMFS-approved survey protocols.
    The first survey day involved circumnavigating the islands of Guam 
and Rota to detect any stranded or near stranded marine mammals. None 
were detected on or near coastlines.
    Subsequent line-transect surveys encompassed approximately 2,352 km 
(1270 nautical miles) of linear effort, with transect grids distributed 
randomly throughout a 163,300 km\2\ (63,050 miles\2\) area. A total of 
8 sightings were recorded during the five-day period including seven 
cetacean and one unidentified turtle species. Cetacean species sighted 
included a Bryde's whale (Balaenoptera edeni), a Cuvier's beaked whale 
(Ziphius cavirostris), spotted dolphins (Stenella attenuata), pygmy or 
dwarf sperm whale (Kogia spp.), rough-toothed dolphins (Steno 
bredanensis) and two sightings of unidentified dolphin species. No 
unusual behavior was detected. More information regarding the findings 
of these aerial surveys may be found in Appendix B of the VS 07 
Monitoring report, which is posted on the NMFS Web site, at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm.
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General Conclusions Drawn From Review of Monitoring Reports

    Because NMFS has received only one monitoring report from sonar 
training in the MIRC Study Area, it is difficult to draw biological 
conclusions. However, NMFS can draw some general conclusions from the 
content of the monitoring reports:
    (a) Data from watchstanders is generally useful to indicate the 
presence or absence of marine mammals within the safety zones (and 
sometimes without) and to document the implementation of mitigation 
measures, but does not provide useful species-specific information or 
behavioral data. Data gathered by independent observers can provide 
very valuable information at a level of detail not possible with 
watchstanders (such as data gathered by independent, biologist monitors 
in Hawaii and submitted to NMFS in a monitoring report, which indicated 
the presence of sub-adult sei whales in the Hawaiian Islands in fall, 
potentially indicating the use of the area for breeding).
    (b) Though it is by no means conclusory, it is worth noting that no 
instances of obvious behavioral disturbance were observed by the Navy 
watchstanders. Of course, these observations only cover the animals 
that were at the surface (or slightly below in the case of aerial 
surveys) and within the distance that the observers can see with the 
big-eye binoculars or from the aircraft.
    (c) NMFS and the Navy need to more carefully designate what 
information should be gathered during monitoring, as some reports 
contain different information, making cross-report comparisons 
difficult. This issue is currently being considered in the development 
of the ICMP.

Adaptive Management

    The final regulations governing the take of marine mammals 
incidental to Navy training exercises in the MIRC will contain an 
adaptive management component. Our understanding of the effects of 
MFAS/HFAS and explosives on marine mammals is still in its relative 
infancy, 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 (though not the MIRC 
in the Navy's over 60 years of use of the area for sonar testing and 
training). The use of adaptive management will allow NMFS to consider 
new information from different sources to determine (with input from 
the Navy regarding practicability) on an annual basis if mitigation or 
monitoring measures should be modified (including additions or 
deletions) if new data suggest that such modifications are appropriate 
for subsequent annual LOAs.
    Following are some of the possible sources of applicable data:
    <bullet> Results from the Navy's monitoring from the previous year 
(either from MIRC or other locations).
    <bullet> Findings of the Workshop that the Navy will convene in 
2011 to analyze monitoring results to date, review

[[Page 53843]]

current science, and recommend modifications, as appropriate to the 
monitoring protocols to increase monitoring effectiveness.
    <bullet> Compiled results of Navy funded research and development 
(R&D) studies (presented pursuant to the ICMP, which is discussed 
elsewhere in this document).
    <bullet> Results from specific stranding investigations (either 
from MIRC or other locations, and involving coincident MFAS/HFAS or 
explosives training or not involving coincident use).
    <bullet> Results from the Long Term Prospective Study described 
above.
    <bullet> Results from general marine mammal and sound research.
    <bullet> Any information which reveals that marine mammals may have 
been taken in a manner, extent or number not authorized by these 
regulations or subsequent Letters of Authorization.
    Mitigation measures could be modified, added, or deleted if new 
information suggests that such modifications would have a reasonable 
likelihood of accomplishing the goals of mitigation laid out in this 
proposed rule and if the measures are practicable. NMFS would also 
coordinate with the Navy to modify, add, or delete the existing 
monitoring requirements if the new data suggest that the addition of 
(or deletion of) a particular measure would more effectively accomplish 
the goals of monitoring laid out in this proposed rule. 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 the data and issue annual LOAs. NMFS and the Navy will meet 
annually, prior to LOA issuance, to discuss the monitoring reports, 
Navy R&D developments, and current science and whether mitigation or 
monitoring modifications are appropriate.

Reporting

    In order to issue an ITA for an activity, Section 101(a)(5)(A) of 
the MMPA states that NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such taking''. Effective reporting is 
critical both to compliance as well as ensuring that the most value is 
obtained from the required monitoring. Proposed reporting requirements 
may be modified, removed, or added based on information or comments 
received during the public comment period. Currently, there are several 
different reporting requirements pursuant to these proposed 
regulations:

General Notification of Injured or Dead Marine Mammals

    Navy personnel will ensure that NMFS is notified immediately (see 
Communication Plan) or as soon as clearance procedures allow if an 
injured, stranded, or dead marine mammal is found during or shortly 
after, and in the vicinity of, any Navy training exercise utilizing 
MFAS, HFAS, or underwater explosive detonations. The Navy will provide 
NMFS with species or description of the animal(s), the condition of the 
animal(s) (including carcass condition if the animal is dead), 
location, time of first discovery, observed behaviors (if alive), and 
photo or video (if available). The MIRC Stranding Response Plan 
contains more specific reporting requirements for specific 
circumstances.
    In the event that an injured, stranded, or dead marine mammal is 
found by the Navy that is not in the vicinity of, or found during or 
shortly after MFAS, HFAS, or underwater explosive detonations, the Navy 
will report the same information as listed above as soon as 
operationally feasible and clearance procedures allow.

General Notification of a Ship Strike

    In the event of a ship strike by any Navy vessel, at any time or 
place, the Navy shall do the following:
    <bullet> Immediately report to NMFS the species identification (if 
known), location (lat/long) of the animal (or the strike if the animal 
has disappeared), and whether the animal is alive or dead (or unknown).
    <bullet> Report to NMFS as soon as operationally feasible the size 
and length of animal, an estimate of the injury status (e.g., dead, 
injured but alive, injured and moving, unknown, etc.), vessel class/
type and operational status.
    <bullet> Report to NMFS the vessel length, speed, and heading as 
soon as feasible.
    <bullet> Provide NMFS a photo or video, if equipment is available.

Annual MIRC Monitoring Plan Report

    The Navy shall submit a report annually on November 15 describing 
the implementation and results (through September 15 of the same year) 
of the MIRC Monitoring Plan, described above. Data collection methods 
will be standardized across range complexes to allow for comparison in 
different geographic locations. Although additional information will 
also be gathered, the marine mammal observers (MMOs) collecting marine 
mammal data pursuant to the MIRC Monitoring Plan shall, at a minimum, 
provide the same marine mammal observation data required in the MFAS/
HFAS major Training Exercises section of the Annual MIRC Exercise 
Report referenced below.
    The MIRC Monitoring Plan Report may be provided to NMFS within a 
larger report that includes the required Monitoring Plan Reports from 
multiple Range Complexes.

Annual MIRC Exercise Report

    The Navy will submit an Annual MIRC Report on November 15 of every 
year (covering data gathered through September 15). This report shall 
contain the subsections and information indicated below.

MFAS/HFAS Major Training Exercises

    This section shall contain the following information for the 
following Coordinated and Strike Group exercises, which for simplicity 
will be referred to as major training exercises for reporting (MTERs): 
Joint Multi-strike Group Exercises; Joint Expeditionary Exercises; and 
Marine Air Ground Task Force MIRC:
    (a) Exercise Information (for each MTER):
    (i) Exercise designator.
    (ii) Date that exercise began and ended.
    (iii) Location.
    (iv) Number and types of active sources used in the exercise.
    (v) Number and types of passive acoustic sources used in exercise.
    (vi) Number and types of vessels, aircraft, etc., participating in 
exercise.
    (vii) Total hours of observation by watchstanders.
    (viii) Total hours of all active sonar source operation.
    (ix) Total hours of each active sonar source (along with 
explanation of how hours are calculated for sources typically 
quantified in alternate way (buoys, torpedoes, etc.)).
    (x) Wave height (high, low, and average during exercise).
    (b) Individual marine mammal sighting info (for each sighting in 
each MTER):
    (i) Location of sighting.
    (ii) Species (if not possible--indication of whale/dolphin/
pinniped).
    (iii) Number of individuals.
    (iv) Calves observed (y/n).
    (v) Initial Detection Sensor.
    (vi) Indication of specific type of platform observation made from 
(including, for example, what type of surface vessel, i.e., FFG, DDG, 
or CG).
    (vii) Length of time observers maintained visual contact with 
marine mammal(s).
    (viii) Wave height (in feet).
    (ix) Visibility.

[[Page 53844]]

    (x) Sonar source in use (y/n).
    (xi) Indication of whether animal is <200yd, 200-500yd, 500-1000yd, 
1000-2000yd, or >2000yd from sonar source in (x) above.
    (xiii) Mitigation Implementation--Whether operation of sonar sensor 
was delayed, or sonar was powered or shut down, and how long the delay 
was.
    (xiv) If source in use (x) is hullmounted, true bearing of animal 
from ship, true direction of ship's travel, and estimation of animal's 
motion relative to ship (opening, closing, parallel).
    (xv) 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.).
    (c) An evaluation (based on data gathered during all of the MTERs) 
of the effectiveness of mitigation measures designed to avoid exposing 
marine mammals to MFAS. This evaluation shall identify the specific 
observations that support any conclusions the Navy reaches about the 
effectiveness of the mitigation.

ASW Summary

    This section shall include the following information as summarized 
from non-major training exercises (unit-level exercises, such as 
TRACKEXs):
    (a) Total Hours--Total annual hours of each type of sonar source 
(along with explanation of how hours are calculated for sources 
typically quantified in alternate way (buoys, torpedoes, etc.)).
    (b) Cumulative Impacts--To the extent practicable, the Navy, in 
coordination with NMFS, shall develop and implement a method of 
annually reporting non-major training (i.e., ULT) utilizing hull-
mounted sonar. The report shall present an annual (and seasonal, where 
practicable) depiction of non-major training exercises geographically 
across MIRC. The Navy shall include (in the MIRC annual report) a brief 
annual progress update on the status of the development of an effective 
and unclassified method to report this information until an agreed-upon 
(with NMFS) method has been developed and implemented.

Sonar Exercise Notification

    The Navy shall submit to the NMFS Office of Protected Resources 
(specific contact information to be provided in LOA) either an 
electronic (preferably) or verbal report within fifteen calendar days 
after the completion of any MTER indicating:
    (1) Location of the exercise.
    (2) Beginning and end dates of the exercise.
    (3) Type of exercise.

Improved Extended Echo-Ranging System (IEER)/Advanced Extended Echo-
Ranging System (AEER) Summary

    This section shall include an annual summary of the following IEER 
and AEER information:
    (i) Total number of IEER and AEER events conducted in MIRC Study 
Area.
    (ii) Total expended/detonated rounds (buoys).
    (iii) Total number of self-scuttled IEER rounds.

Sinking Exercises (SINKEXs)

    This section shall include the following information for each 
SINKEX completed that year:
    (a) Exercise information:
    (i) Location
    (ii) Date and time exercise began and ended
    (iii) Total hours of observation by watchstanders before, during, 
and after exercise
    (iv) Total number and types of rounds expended/explosives detonated
    (v) Number and types of passive acoustic sources used in exercise
    (vi) Total hours of passive acoustic search time
    (vii) Number and types of vessels, aircraft, etc., participating in 
exercise
    (viii) Wave height in feet (high, low and average during exercise)
    (ix) Narrative description of sensors and platforms utilized for 
marine mammal detection and timeline illustrating how marine mammal 
detection was conducted
    (b) Individual marine mammal observation during SINKEX (by Navy 
lookouts) information:
    (i) Location of sighting
    (ii) Species (if not possible--indication of whale/dolphin/
pinniped)
    (iii) Number of individuals
    (iv) Calves observed (y/n)
    (v) Initial detection sensor
    (vi) Length of time observers maintained visual contact with marine 
mammal
    (vii) Wave height
    (viii) Visibility
    (ix) Whether sighting was before, during, or after detonations/
exercise, and how many minutes before or after
    (x) Distance of marine mammal from actual detonations (or target 
spot if not yet detonated)--use four categories to define distance: (1) 
The modeled injury threshold radius for the largest explosive used in 
that exercise type in that OPAREA (426 m for SINKEX in MIRC); (2) the 
required exclusion zone (1 nm for SINKEX in MIRC); (3) the required 
observation distance (if different than the exclusion zone (2 nm for 
SINKEX in MIRC); and (4) greater than the required observed distance. 
For example, in this case, the observer would indicate if < 426 m, from 
426 m-1 nm, from 1 nm-2 nm, and > 2 nm.
    (xi) Observed behavior--Watchstanders will 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.), 
including speed and direction.
    (xii) Resulting mitigation implementation--Indicate whether 
explosive detonations were delayed, ceased, modified, or not modified 
due to marine mammal presence and for how long.
    (xiii) If observation occurs while explosives are detonating in the 
water, indicate munitions type in use at time of marine mammal 
detection.

Explosives Summary

    The Navy is in the process of improving the methods used to track 
explosive use to provide increased granularity. To the extent 
practicable, the Navy will provide the information described below for 
all of their explosive exercises. Until the Navy is able to report in 
full the information below, they will provide an annual update on the 
Navy's explosive tracking methods, including improvements from the 
previous year.
    (a) Total annual number of each type of explosive exercise (of 
those identified as part of the ``specified activity'' in this final 
rule) conducted in MIRC
    (b) Total annual expended/detonated rounds (missiles, bombs, etc.) 
for each explosive type

MIRC 5-Yr Comprehensive Report

    The Navy shall submit to NMFS a draft report that analyzes and 
summarizes all of the multi-year marine mammal information gathered 
during ASW and explosive exercises for which annual reports are 
required (Annual MIRC Exercise Reports and MIRC Monitoring Plan 
Reports). This report will be submitted at the end of the fourth year 
of the rule (November 2013), covering activities that have occurred 
through July15, 2014.

Comprehensive National ASW Report

    By June, 2014, the Navy shall submit a draft National Report that 
analyzes, compares, and summarizes the active sonar data gathered 
(through January 1, 2014) from the watchstanders and

[[Page 53845]]

pursuant to the implementation of the Monitoring Plans for the 
Northwest Training Range Complex, the Southern California Range 
Complex, the Atlantic Fleet Active Sonar Training, the Hawaii Range 
Complex, the Mariana Islands Range Complex, and the Gulf of Alaska.
    The Navy shall respond to NMFS comments and requests for additional 
information or clarification on the MIRC Range Complex Comprehensive 
Report, the Comprehensive National ASW report, the Annual MIRC Range 
Complex Exercise Report, or the Annual MIRC Range Complex Monitoring 
Plan Report (or the multi-Range Complex Annual Monitoring Plan Report, 
if that is how the Navy chooses to submit the information) if submitted 
within 3 months of receipt. These reports will be considered final 
after the Navy has adequately addressed NMFS' comments or provided the 
requested information, or three months after the submittal of the draft 
if NMFS does not comment by then.

Estimated Take of Marine Mammals

    As mentioned previously, one of the main purposes of NMFS' effects 
assessments is to identify the permissible methods of taking, meaning: 
The nature of the take (e.g., resulting from anthropogenic noise vs. 
from ship strike, etc.); the regulatory level of take (i.e., mortality 
vs. Level A or Level B harassment) and the amount of take. In the 
Potential Effects of Exposure of Marine Mammal to MFAS/HFAS and 
Underwater Detonations section, NMFS identified the lethal responses, 
physical trauma, sensory impairment (permanent and temporary threshold 
shifts and acoustic masking), physiological responses (particular 
stress responses), and behavioral responses that could potentially 
result from exposure to MFAS/HFAS or underwater explosive detonations. 
In this section, we will relate the potential effects to marine mammals 
from MFAS/HFAS and underwater detonation of explosives to the MMPA 
statutory definitions of Level A and Level B Harassment and attempt to 
quantify the effects that might occur from the specific training 
activities that the Navy is proposing in the MIRC.
    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 in the Potential 
Effects of Exposure of Marine Mammal to MFAS/HFAS and Underwater 
Detonations Section, 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 MFAS/HFAS or underwater detonations (or another stressor), is 
considered Level B Harassment. Louder sounds (when other factors are 
not considered) are generally expected to elicit a stronger response. 
Some of the lower level physiological stress responses discussed in the 
Potential Effects of Exposure of Marine Mammal to MFAS/HFAS and 
Underwater Detonations Section: Stress Section will also likely co-
occur with the predicted harassments, although these responses are more 
difficult to detect and fewer data exist relating these responses to 
specific received levels of sound. When Level B Harassment is predicted 
based on estimated behavioral responses, those takes may have a stress-
related physiological component as well.
    In the effects section above, 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 categories. 
Behavioral harassment would not typically include behaviors ranked 0-3 
in Southall et al. (2007).
    Acoustic Masking and Communication Impairment--The severity or 
importance of an acoustic masking event can vary based on the length of 
time that the masking occurs, the frequency of the masking signal 
(which determines which sounds are masked, which may be of varying 
importance to the animal), and other factors. Some acoustic masking 
would be considered Level B Harassment, if it can disrupt natural 
behavioral patterns by interrupting or limiting the marine mammal's 
receipt or transmittal of important information or environmental cues.
    TTS--As discussed previously, TTS can disrupt behavioral patterns 
by inhibiting an animal's ability to communicate with conspecifics and 
interpret other environmental cues important for predator avoidance and 
prey capture. However, 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). For example, a marine mammal may be 
able to readily compensate for a brief, relatively small amount of TTS 
in a non-critical frequency range that takes place during a time when 
the animal is traveling through the open ocean, where ambient noise is 
lower and there are not as many competing sounds present. 
Alternatively, a larger amount and longer duration of TTS sustained 
during a time when communication is critical for successful mother/calf 
interactions could have more serious impacts if it were in the same 
frequency band as the necessary vocalizations and of a severity that it 
impeded communication.

[[Page 53846]]

    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 either MFAS/HFAS or underwater detonations) as Level B 
Harassment, not Level A Harassment (injury).

Level A Harassment

    Of the potential effects that were described in the Potential 
Effects of Exposure of Marine Mammals to MFAS/HFAS and Underwater 
Detonations Section, following are the types of effects that fall into 
the Level A Harassment category:
    PTS--PTS (resulting from either 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. Although 
PTS is considered an injury, the effects of PTS on the fitness of an 
individual can vary based on the degree of TTS and the frequency band 
that it is in.
    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 active 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 or, potentially, mortality.
    Tissue Damage Due to Behaviorally Mediated Bubble Growth--Several 
authors suggest mechanisms in which marine mammals could behaviorally 
respond to exposure to MFAS/HFAS by altering their dive patterns in a 
manner (unusually rapid ascent, unusually long series of surface dives, 
etc.) that might result in unusual bubble formation or growth 
ultimately resulting in tissue damage (emboli, etc.). 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 the tissue effects 
observed from recent beaked whale strandings are consistent with gas 
emboli and bubble-induced tissue separations (Jepson et al., 2003; 
Fernandez et al., 2005, Tyack et al., 2006), 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 or, 
potentially, mortality.
    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 Strike, Ordnance Strike, Entanglement--Although not 
anticipated (or authorized) to occur, vessel strike, ordnance strike, 
or entanglement in materials associated with the specified action are 
considered Level A Harassment or mortality.

Acoustic Take Criteria

    For the purposes of an MMPA incidental take 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 MFAS/HFAS and underwater detonations 
cannot be detected or measured (because, e.g., not all responses are 
visible external to animal, a portion of exposed animals are 
underwater, many animals are located many miles from observers and 
covering very large area, etc.) and because NMFS must authorize take 
prior to the impacts to marine mammals, a method is needed to estimate 
the number of individuals that will be taken, pursuant to the MMPA, 
based on the proposed action. To this end, NMFS developed acoustic 
criteria that estimate at what received level (when exposed to MFAS/
HFAS or explosive detonations) Level B Harassment, Level A Harassment, 
and mortality (for explosives) of marine mammals would occur. The 
acoustic criteria for MFAS/HFAS and Underwater Detonations (IEER) are 
discussed below.

MFAS/HFAS Acoustic Criteria

    Because relatively few applicable data exist to support acoustic 
criteria specifically for HFAS and because such a small percentage of 
the active sonar pings that marine mammals will likely be exposed to 
incidental to this activity come from a HFAS source (the vast majority 
come from MFAS sources), NMFS will apply the criteria developed for the 
MFAS to the HFAS as well.
    NMFS utilizes three acoustic criteria to assess impacts from MFAS/
HFAS: PTS (injury--Level A Harassment), TTS (Level B Harassment), and 
behavioral harassment (Level B Harassment). Because there is related 
quantitative data, the TTS criterion is a valuable tool for more 
specifically identifying the likely impacts to marine mammals from 
MFAS/HFAS, plus the PTS criteria are extrapolated from it. However, TTS 
is simply a subset of level B Harassment--

[[Page 53847]]

the likely ultimate effects of which are not anticipated to necessarily 
be any more severe than the behavioral impacts that would be expected 
to occur at the same received levels. Because the TTS and PTS criteria 
are derived similarly and the PTS criteria are extrapolated from the 
TTS data, the TTS and PTS acoustic criteria will be presented first, 
before the behavioral criteria.
    For more information regarding these criteria, please see the 
Navy's DEIS for MIRC.

Level B Harassment Threshold (TTS)

    As mentioned above, behavioral disturbance, acoustic masking, and 
TTS are all considered Level B Harassment. Marine mammals would usually 
be behaviorally disturbed at lower received levels than those at which 
they would likely sustain TTS, so the levels at which behavioral 
disturbances are likely to occur are 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). Conversely, TTS is a physiological 
effect that has been studied and quantified in laboratory conditions. 
Because data exist to support an estimate of the received levels at 
which marine mammals will incur TTS, NMFS uses an acoustic criterion to 
estimate the number of marine mammals that might sustain TTS. TTS is a 
subset of Level B Harassment.
    A number of investigators have measured TTS in marine mammals. 
These studies measured hearing thresholds in trained marine mammals 
before and after exposure to intense sounds. The existing cetacean TTS 
data are summarized in the following bullets.
    <bullet> Schlundt et al. (2000) reported the results of TTS 
experiments conducted with 5 bottlenose dolphins and 2 belugas exposed 
to 1-second tones. This paper also includes a reanalysis of preliminary 
TTS data released in a technical report by Ridgway et al. (1997). At 
frequencies of 3, 10, and 20 kHz, sound pressure levels (SPLs) 
necessary to induce measurable amounts (6 dB or more) of TTS were 
between 192 and 201 dB re 1 [mu]Pa (EL = 192 to 201 dB re 1 [mu]Pa\2\-
s). The mean exposure SPL and EL for onset-TTS were 195 dB re

1 [mu]Pa and 195 dB re 1 [mu]Pa\2\-s, respectively.

    <bullet> Finneran et al. (2001, 2003, 2005) described TTS 
experiments conducted with bottlenose dolphins exposed to 3-kHz tones 
with durations of 1, 2, 4, and 8 seconds. Small amounts of TTS (3 to 6 
dB) were observed in one dolphin after exposure to ELs between 190 and 
204 dB re 1 [mu]Pa\2\-s. These results were consistent with the data of 
Schlundt et al. (2000) and showed that the Schlundt et al. (2000) data 
were not significantly affected by the masking sound used. These 
results also confirmed that, for tones with different durations, the 
amount of TTS is best correlated with the exposure EL rather than the 
exposure SPL.
    <bullet> Nachtigall et al. (2003) measured TTS in a bottlenose 
dolphin exposed to octave-band sound centered at 7.5 kHz. Nachtigall et 
al. (2003a) reported TTSs of about 11 dB measured 10 to 15 minutes 
after exposure to 30 to 50 minutes of sound with SPL 179 dB re 1 [mu]Pa 
(EL about 213 dB re [mu]Pa\2\-s). No TTS was observed after exposure to 
the same sound at 165 and 171 dB re 1 [mu]Pa. Nachtigall et al. (2004) 
reported TTSs of around 4 to 8 dB 5 minutes after exposure to 30 to 50 
minutes of sound with SPL 160 dB re 1 [mu]Pa (EL about 193 to 195 dB re 
1 [mu]Pa\2\-s). The difference in results was attributed to faster 
post-exposure threshold measurement--TTS may have recovered before 
being detected by Nachtigall et al. (2003). These studies showed that, 
for long-duration exposures, lower sound pressures are required to 
induce TTS than are required for short-duration tones.
    <bullet> Finneran et al. (2000, 2002) conducted TTS experiments 
with dolphins and belugas exposed to impulsive sounds similar to those 
produced by distant underwater explosions and seismic waterguns. These 
studies showed that, for very short-duration impulsive sounds, higher 
sound pressures were required to induce TTS than for longer-duration 
tones.
    <bullet> Finneran et al. (2007) conducted TTS experiments with 
bottlenose dolphins exposed to intense 20 kHz fatiguing tone. 
Behavioral and auditory evoked potentials (using sinusoidal amplitude 
modulated tones creating auditory steady state response [AASR]) were 
used to measure TTS. The fatiguing tone was either 16 (mean = 193 re 
1[mu]Pa, SD = 0.8) or 64 seconds (185-186 re 1[mu]Pa) in duration. TTS 
ranged from 19-33dB from behavioral measurements and 40-45dB from ASSR 
measurements.
    <bullet> Kastak et al. (1999a, 2005) conducted TTS experiments with 
three species of pinnipeds, California sea lion, northern elephant seal 
and a Pacific harbor seal, exposed to continuous underwater sounds at 
levels of 80 and 95 dB sensation level at 2.5 and 3.5 kHz for up to 50 
minutes. Mean TTS shifts of up to 12.2 dB occurred with the harbor 
seals showing the largest shift of 28.1 dB. Increasing the sound 
duration had a greater effect on TTS than increasing the sound level 
from 80 to 95 dB.
    Some of the more important data obtained from these studies are 
onset-TTS levels (exposure levels sufficient to cause a just-measurable 
amount of TTS) often defined as 6 dB of TTS (for example, Schlundt et 
al., 2000) and the fact that energy metrics (sound exposure levels 
(SEL), which include a duration component) better predict when an 
animal will sustain TTS than pressure (SPL) alone. NMFS' TTS criterion 
(which indicates the received level at which onset TTS (>6dB) is 
induced) for MFAS/HFAS and cetaceans is 195 dB re 1 [mu]Pa\2\-s (based 
on mid-frequency cetaceans--no published data exist on auditory effects 
of noise in low- or high-frequency cetaceans (Southall et al. (2007)).
    A detailed description of how this TTS criterion was derived from 
the results of the above studies may be found in Chapter 3 of Southall 
et al. (2007), as well as the Navy's MIRC LOA application.

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 the 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 discovered through 
study of terrestrial mammals. NMFS uses the following acoustic 
criterion for injury of cetaceans: 215 dB re 1 [mu]Pa\2\-s (based on 
mid-frequency cetaceans--no published data exist on auditory effects of 
noise in low- or high-frequency cetaceans (Southall et al. (2007)).
    This criterion is based on a 20 dB increase in SEL over that 
required for onset-TTS. Extrapolations from terrestrial mammal data 
indicate that PTS occurs at 40 dB or more of TS, and that TS growth 
occurs at a rate of approximately 1.6 dB TS per dB increase in EL. 
There is a 34-dB TS difference between onset-TTS (6 dB)

[[Page 53848]]

and onset-PTS (40 dB). Therefore, an animal would require approximately 
20dB of additional exposure (34 dB divided by 1.6 dB) above onset-TTS 
to reach PTS. A detailed description of how TTS criteria were derived 
from the results of the above studies may be found in Chapter 3 of 
Southall et al. (2007), as well as the Navy's MIRC LOA application. 
Southall et al. (2007) recommend a precautionary dual criteria for TTS 
(230 dB re 1 [mu]Pa (SPL peak pressure) in addition to 215 dB re 1 
[mu]Pa\2\-s (SEL)) to account for the potentially damaging transients 
embedded within non-pulse exposures. However, in the case of MFAS/HFAS, 
the distance at which an animal would receive 215 dB (SEL) is farther 
from the source (i.e., more conservative) than the distance at which 
they would receive 230 dB (SPL peak pressure) and therefore, it is not 
necessary to consider 230 dB peak.
    We note here that behaviorally mediated injuries (such as those 
that have been hypothesized as the cause of some beaked whale 
strandings) could potentially occur in response to received levels 
lower than those believed to directly result in tissue damage. As 
mentioned previously, data to support a quantitative estimate of these 
potential effects (for which the exact mechanism is not known and in 
which factors other than received level may play a significant role) do 
not exist. However, based on the number of years (more than 60) and 
number of hours of MFAS per year that the U.S. (and other countries) 
has operated compared to the reported (and verified) cases of 
associated marine mammal strandings, NMFS believes that the probability 
of these types of injuries is very low.

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 the Rim of the 
Pacific Exercises (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 173dB 
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,'' ``dose-response 
functions,'' or ``stress-response functions'' in other risk assessment 
contexts) allow for probability of a response that NMFS would classify 
as harassment to occur over a range of possible received levels 
(instead of one number) and assume that the probability of a response 
depends first on the ``dose'' (in this case, the received level of 
sound) and that the probability of a response increases as the ``dose'' 
increases (see Figure 1a). In January, 2009, NMFS issued 3 final rules 
governing the incidental take of marine mammals (Navy's Hawaii Range 
Complex, Southern California Range Complex, and Atlantic Fleet Active 
Sonar Training) 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 in 
the Effects section, factors other than received level (such as 
distance from or bearing to the sound source) can affect the way that 
marine mammals respond; however, data to support a quantitative 
analysis of those (and other factors) do not currently exist. NMFS will 
continue to modify these criteria as new data that meet NMFS standards 
of quality 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] TP20OC09.009

Where:

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

    In order to use this function to estimate the percentage of an 
exposed population that would respond in a manner that NMFS classifies 
as Level B Harassment, based on a given received level, the values for 
B, K and A need to be identified.
    B Parameter (Basement)--The B parameter is the estimated received 
level below which the probability of 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 approaches zero for the MFAS/HFAS risk 
assessment. At this received level, the curve would predict that the 
percentage of the exposed population that would be taken by Level B 
Harassment approaches zero. For MFAS/HFAS, NMFS has determined that B = 
120 dB. This level is based on a broad overview of the levels at which 
many species have been reported responding to a variety of sound 
sources.
    K Parameter (representing the 50 percent Risk Point)--The K 
parameter is based on the received level that corresponds to 50% risk, 
or the received level at which we believe 50% of the animals exposed to 
the designated received level will respond in a manner that NMFS 
classifies as Level B Harassment. The K parameter (K = 45 dB) is based 
on three data sets in which marine mammals exposed to mid-frequency 
sound sources were reported to respond in a manner that NMFS would 
classify as Level B Harassment. There is widespread consensus that 
marine mammal responses to MFA sound signals need to be better defined 
using controlled exposure experiments

[[Page 53849]]

(Cox et al., 2006; Southall et al., 2007). The Navy is contributing to 
an ongoing 3-Phase behavioral response study in the Bahamas that is 
expected to provide some initial information on beaked whales, the 
species identified as the most sensitive to MFAS. NMFS is leading this 
international effort with scientists from various academic institutions 
and research organizations to conduct studies on how marine mammals 
respond to underwater sound exposures. The results from Phase 1 of this 
study are discussed in the Potential Effects of Specified Activities on 
Marine Mammals section and the results from Phase 2 are expected to be 
available in late 2009. Phase 3 was conducted in the Mediterranean Sea 
in the summer of 2009. Additionally, the Navy recently tagged whales in 
conjunction with the 2008 RIMPAC exercises; however, analyses of these 
data are not yet complete. Until additional appropriate data are 
available, however, NMFS and the Navy have determined that the 
following three data sets are most applicable for the direct use in 
establishing the K parameter for the MFAS/HFAS risk function. These 
data sets, summarized below, represent the only known data that 
specifically relate altered behavioral responses (that NMFS would 
consider Level B Harassment) to exposure--at specific received levels--
to MFAS and sources within or having components within the range of 
MFAS (1-10 kHz).
    Even though these data are considered the most representative of 
the proposed specified activities, and therefore the most appropriate 
on which to base the K parameter (which basically determines the 
midpoint) of the risk function, these data have limitations, which are 
discussed in Appendix D of the Navy's DEIS for MIRC.
    1. Controlled Laboratory Experiments With Odontocetes (SSC 
Dataset)--Most of the observations of the behavioral responses of 
toothed whales resulted from a series of controlled experiments on 
bottlenose dolphins and beluga whales conducted by researchers at SSC's 
facility in San Diego, California (Finneran et al., 2001, 2003, 2005; 
Finneran and Schlundt, 2004; Schlundt et al., 2000). In experimental 
trials (designed to measure TTS) with marine mammals trained to perform 
tasks when prompted, scientists evaluated whether the marine mammals 
still performed these tasks when exposed to mid-frequency tones. 
Altered behavior during experimental trials usually involved refusal of 
animals to return to the site of the sound stimulus but also included 
attempts to avoid an exposure in progress, aggressive behavior, or 
refusal to further participate in tests.
    Finneran and Schlundt (2004) examined behavioral observations 
recorded by the trainers or test coordinators during the Schlundt et 
al. (2000) and Finneran et al. (2001, 2003, 2005) experiments. These 
included observations from 193 exposure sessions (fatiguing stimulus 
level > 141 dB re 1[mu]Pa) conducted by Schlundt et al. (2000) and 21 
exposure sessions conducted by Finneran et al. (2001, 2003, 2005). The 
TTS experiments that supported Finneran and Schlundt (2004) are further 
explained below:
    <bullet> Schlundt et al. (2000) provided a detailed summary of the 
behavioral responses of trained marine mammals during TTS tests 
conducted at SSC San Diego with 1-sec tones and exposure frequencies of 
0.4 kHz, 3 kHz, 10 kHz, 20 kHz and 75 kHz. Schlundt et al. (2000) 
reported eight individual TTS experiments. The experiments were 
conducted in San Diego Bay. Because of the variable ambient noise in 
the bay, low-level broadband masking noise was used to keep hearing 
thresholds consistent despite fluctuations in the ambient noise. 
Schlundt et al. (2000) reported that ``behavioral alterations,'' or 
deviations from the behaviors the animals being tested had been trained 
to exhibit, occurred as the animals were exposed to increasing 
fatiguing stimulus levels.
    <bullet> Finneran et al. (2001, 2003, 2005) conducted 2 separate 
TTS experiments using 1-sec tones at 3 kHz. The test methods were 
similar to that of Schlundt et al. (2000) except the tests were 
conducted in a pool with very low ambient noise level (below 50 dB re 1 
[mu]Pa\2\/hertz [Hz]), and no masking noise was used. In the first, 
fatiguing sound levels were increased from 160 to 201 dB SPL. In the 
second experiment, fatiguing sound levels between 180 and 200 dB SPL 
were randomly presented.
    Bottlenose dolphins exposed to 1-second (sec) intense tones 
exhibited short-term changes in behavior above received sound levels of 
178 to 193 dB re 1 [mu]Pa (rms), and beluga whales did so at received 
levels of 180 to 196 dB and above.
    2. Mysticete Field Study (Nowacek et al., 2004)--The only available 
and applicable data relating mysticete responses to exposure to mid-
frequency sound sources is from Nowacek et al. (2004). Nowacek et al. 
(2004) documented observations of the behavioral response of North 
Atlantic right whales exposed to alert stimuli containing mid-frequency 
components in the Bay of Fundy. Investigators used archival digital 
acoustic recording tags (DTAG) to record the behavior (by measuring 
pitch, roll, heading, and depth) of right whales in the presence of an 
alert signal, and to calibrate received sound levels. The alert signal 
was 18 minutes of exposure consisting of three 2-minute signals played 
sequentially three times over. The three signals had a 60% duty cycle 
and consisted of: (1) Alternating 1-sec pure tones at 500 Hz and 850 
Hz; (2) a 2-sec logarithmic down-sweep from 4,500 Hz to 500 Hz; and (3) 
a pair of low (1,500 Hz)-high (2,000 Hz) sine wave tones amplitude 
modulated at 120 Hz and each 1-sec long. The purposes of the alert 
signal were (a) to pique the mammalian auditory system with disharmonic 
signals that cover the whales' estimated hearing range; (b) to maximize 
the signal to noise ratio (obtain the largest difference between 
background noise) and (c) to provide localization cues for the whale. 
The maximum source level used was 173 dB SPL.
    Nowacek et al. (2004) reported that five out of six whales exposed 
to the alert signal with maximum received levels ranging from 133 to 
148 dB re 1 [mu]Pa significantly altered their regular behavior and did 
so in identical fashion. Each of these five whales: (i) Abandoned their 
current foraging dive prematurely as evidenced by curtailing their 
`bottom time'; (ii) executed a shallow-angled, high power (i.e. 
significantly increased fluke stroke rate) ascent; (iii) remained at or 
near the surface for the duration of the exposure, an abnormally long 
surface interval; and (iv) spent significantly more time at subsurface 
depths (1-10 m) compared with normal surfacing periods when whales 
normally stay within 1 m (1.1 yd) of the surface.
    3. Odontocete Field Data (Haro Strait--USS SHOUP)--In May 2003, 
killer whales (Orcinus orca) were observed exhibiting behavioral 
responses generally described as avoidance behavior while the U.S. Ship 
(USS) SHOUP was engaged in MFAS in the Haro Strait in the vicinity of 
Puget Sound, Washington. Those observations have been documented in 
three reports developed by Navy and NMFS (NMFS, 2005; Fromm, 2004a, 
2004b; DON, 2003). Although these observations were made in an 
uncontrolled environment, the sound field that may have been associated 
with the active sonar operations was estimated using standard acoustic 
propagation models that were verified (for some but not all signals) 
based on calibrated in situ measurements from an independent researcher 
who recorded the sounds during the event. Behavioral

[[Page 53850]]

observations were reported for the group of whales during the event by 
an experienced marine mammal biologist who happened to be on the water 
studying them at the time. The observations associated with the USS 
SHOUP provide the only data set available of the behavioral responses 
of wild, non-captive animal upon actual exposure to AN/SQS-53 sonar.
    U.S. Department of Commerce (National Marine Fisheries, 2005a); 
U.S. Department of the Navy (2004b); Fromm (2004a, 2004b) documented 
reconstruction of sound fields produced by USS SHOUP associated with 
the behavioral response of killer whales observed in Haro Strait. 
Observations from this reconstruction included an approximate closest 
approach time which was correlated to a reconstructed estimate of 
received level. Observations from this reconstruction included an 
estimate of 169.3 dB SPL which represents the mean level at a point of 
closest approach within a 500 m wide area in which the animals were 
exposed. Within that area, the estimated received levels varied from 
approximately 150 to 180 dB SPL.
    Calculation of K Parameter--NMFS and the Navy used the mean of the 
following values to define the midpoint of the function: (1) The mean 
of the lowest received levels (185.3 dB) at which individuals responded 
with altered behavior to 3 kHz tones in the SSC data set; (2) the 
estimated mean received level value of 169.3 dB produced by the 
reconstruction of the USS SHOUP incident in which killer whales exposed 
to MFAS (range modeled possible received levels: 150 to 180 dB); and 
(3) the mean of the 5 maximum received levels at which Nowacek et al. 
(2004) observed significantly altered responses of right whales to the 
alert stimuli than to the control (no input signal) is 139.2 dB SPL. 
The arithmetic mean of these three mean values is 165 dB SPL. The value 
of K is the difference between the value of B (120 dB SPL) and the 50% 
value of 165 dB SPL; therefore, K=45.
    A Parameter (Steepness)--NMFS determined that a steepness parameter 
(A) = 10 is appropriate for odontocetes (except harbor porpoises) and 
pinnipeds and A = 8 is appropriate for mysticetes.
    The use of a steepness parameter of A = 10 for odontocetes for the 
MFAS/HFAS risk function was based on the use of the same value for the 
SURTASS LFA risk continuum, which was supported by a sensitivity 
analysis of the parameter presented in Appendix D of the SURTASS/LFA 
FEIS (U.S. Department of the Navy, 2001c). As concluded in the SURTASS 
FEIS/EIS, the value of A=10 produces a curve that has a more gradual 
transition than the curves developed by the analyses of migratory gray 
whale studies (Malme et al., 1984; Buck and Tyack, 2000; and SURTASS 
LFA Sonar EIS, Subchapters 1.43, 4.2.4.3 and Appendix D, and National 
Marine Fisheries Service, 2008).
    NMFS determined that a lower steepness parameter (A = 8), resulting 
in a shallower curve, was appropriate for use with mysticetes and MFAS/
HFAS. The Nowacek et al. (2004) dataset contains the only data 
illustrating mysticete behavioral responses to a sound source that 
encompasses frequencies in the mid-frequency sound spectrum. A 
shallower curve (achieved by using A = 8) better reflects the risk of 
behavioral response at the relatively low received levels at which 
behavioral responses of right whales were reported in the Nowacek et 
al. (2004) data. Compared to the odontocete curve, this adjustment 
results in an increase in the proportion of the exposed population of 
mysticetes being classified as behaviorally harassed at lower RLs, such 
as those reported in the Novacek report, and is supported by the only 
representative dataset currently available.
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    Basic Application of the Risk Function--The risk function is used 
to estimate the percentage of an exposed population that is likely to 
exhibit behaviors that would qualify as harassment (as that term is 
defined by the MMPA applicable to military readiness activities, such 
as the Navy's testing and training with MFAS) at a given received level 
of sound. For example, at 165 dB SPL (dB re: 1[mu]Pa rms), the risk (or 
probability) of harassment is defined according to this function as 
50%, and Navy/NMFS applies that by estimating that 50% of the 
individuals exposed at that received level are likely to respond by 
exhibiting behavior that NMFS would classify as behavioral harassment. 
The risk function is not applied to individual animals, only to exposed 
populations.
    The data primarily used to produce the risk function (the K 
parameter) were compiled from four species that had been exposed to 
sound sources in a variety of different circumstances. As a result, the 
risk function represents a general relationship between acoustic 
exposures and behavioral responses that

[[Page 53852]]

is then applied to specific circumstances. That is, the risk function 
represents a relationship that is deemed to be generally true, based on 
the limited, best-available science, but may not be true in specific 
circumstances. In particular, the risk function, as currently derived, 
treats the received level as the only variable that is relevant to a 
marine mammal's behavioral response. However, we know that many other 
variables--the marine mammal's gender, age, and prior experience; the 
activity it is engaged in during an exposure event, its distance from a 
sound source, the number of sound sources, and whether the sound 
sources are approaching or moving away from the animal--can be 
critically important in determining whether and how a marine mammal 
will respond to a sound source (Southall et al., 2007). The data that 
are currently available do not allow for incorporation of these other 
variables in the current risk functions; however, the risk function 
represents the best use of the data that are available. Additionally, 
although these other factors cannot be taken into consideration 
quantitatively in the risk function, NMFS considers these other 
variables qualitatively in our analysis, when applicable data are 
available.
    As more specific and applicable data become available for MFAS/HFAS 
sources, NMFS can use these data to modify the outputs generated by the 
risk function to make them more realistic. Ultimately, data may exist 
to justify the use of additional, alternate, or multi-variate 
functions. For example, as mentioned previously, the distance from the 
sound source and whether it is perceived as approaching or moving away 
can affect the way an animal responds to a sound (Wartzok et al., 
2003). In the MIRC example, animals exposed to received levels between 
120 and 140 dB will likely be more that 125 km away from a sound source 
depending on seasonal variations; those distances could influence 
whether those animals perceive the sound source as a potential threat, 
and their behavioral responses to that threat. Though there are data 
showing response of certain marine mammal species to mid-frequency 
sound sources at that received level, NMFS does not currently have any 
data that describe the response of marine mammals to mid-frequency 
sounds at that distance, much less data that compare responses to 
similar sound levels at varying distances (much less for MFAS/HFAS). 
However, if applicable data meeting NMFS standards were to become 
available, NMFS would re-evaluate the risk function and to incorporate 
any additional variables into the ``take'' estimates.

Explosive Detonation Criteria

    The criteria for mortality, Level A Harassment, and Level B 
Harassment resulting from explosive detonations were initially 
developed for the Navy's Seawolf and Churchill ship-shock trials and 
have not changed. The criteria, which are applied to cetaceans and 
pinnipeds, are summarized in Table 7. Additional information regarding 
the derivation of these criteria is available in the Navy's DEIS for 
the MIRC, the LOA application, and in the Navy's CHURCHILL FEIS (U.S. 
Department of the Navy, 2001c).
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Estimates of Potential Marine Mammal Exposure

    Estimating the take that will result from the proposed activities 
entails the following three general steps: (1) Propagation model 
estimates animals exposed to sources at different levels; (2) further 
modeling determines number of exposures to levels indicated in criteria 
above (i.e., number of takes); and (3) post-modeling corrections refine 
estimates to make them more accurate. More information regarding the 
models used, the assumptions used in the models, and the process of 
estimating take is available in Appendix A of the Navy's Application.
    (1) In order to quantify the types of take described in previous 
sections that are predicted to result from the Navy's specified 
activities, the Navy first uses a sound propagation model that predicts 
the number of animals that will be exposed to a range of levels of 
pressure and energy (of the metrics used in the criteria) from MFAS/
HFAS and explosive detonations based on several important pieces of 
information, including:
    <bullet> Characteristics of the sound sources.
    <bullet> Active sonar source characteristics include: source level 
(with horizontal and vertical directivity corrections), source depth, 
center frequency, source directivity (horizontal/vertical beam width 
and horizontal/vertical steer direction), and ping spacing.
    <bullet> Explosive source characteristics include: the weight of an 
explosive, the type of explosive, the detonation depth, and number of 
successive explosions.
    <bullet> Transmission loss (in 9 representative environmental 
provinces in two seasons) based on: water depth; sound speed 
variability throughout the water column (warm season exhibits a weak 
surface duct, cold season exhibits a relatively strong surface duct); 
bottom geo-acoustic properties (bathymetry); and wind speed.
    <bullet> The estimated density of each marine mammal species in the 
MIRC (see Table 4), horizontally distributed uniformly and vertically 
distributed according to dive profiles based on field data.
    (2) Next, the criteria discussed in the previous section are 
applied to the estimated exposures to predict the number of exposures 
that exceed the criteria, i.e., the number of takes by Level B 
Harassment, Level A Harassment, and mortality.
    (3) During the development of the EIS for MIRC, NMFS and the Navy 
determined that the output of the model could be made more realistic by 
applying post-modeling corrections to account for the following:
    <bullet> Acoustic footprints for active sonar sources must account 
for land masses (by subtracting them out).
    <bullet> Acoustic footprints for active sonar sources should not be 
added independently, rather, the degree to which the footprints from 
multiple ships participating in the same exercise would typically 
overlap needs to be taken into consideration.
    <bullet> Acoustic modeling should account for the maximum number of 
individuals of a species that could potentially be exposed to active 
sonar within the course of 1 day or a discrete continuous sonar event 
if less than 24 hours.
    Last, the Navy's specified activities have been described based on 
best estimates of the number of MFAS/HFAS hours that the Navy will 
conduct. The exact number of hours may vary from year to year, but will 
not exceed the 5-year total indicated in Table 8 (by multiplying the 
yearly estimate by 5) by more than 10%. NMFS estimates that a 10% 
increase in active sonar hours would result in approximately a 10% 
increase in the number of takes, and we have considered this 
possibility in our analysis.
    The Navy's model provides a systematic and repeatable way of 
estimating the number of animals that will be taken by Level A and 
Level B Harassment. The model is based on the sound propagation 
characteristics of the sound sources, physical characteristics of the 
surrounding environment, and a uniform density of marine mammals. As 
mentioned in the previous sections, many other factors will likely 
affect how and the degree to which marine mammals are impacted both at 
the individual and species level by the Navy's activity (such as social 
ecology of the animals, long term exposures in one area, etc.); 
however, in the absence quantitative data, NMFS has, and will continue, 
to evaluate that sort of information qualitatively.

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[[Page 53855]]

Mortality

    Evidence from five beaked whale strandings, all of which have taken 
place outside the MIRC Range Complex, and have occurred over 
approximately a decade, suggests that the exposure of beaked whales to 
MFAS in the presence of certain conditions (e.g., multiple units using 
active sonar, steep bathymetry, constricted channels, strong surface 
ducts, etc.) may result in strandings, potentially leading to 
mortality. Although not all 5 of these physical factors believed to 
have contributed to the likelihood of beaked whale strandings are 
present, in their aggregate, in the MIRC, scientific uncertainty exists 
regarding what other factors, or combination of factors, may contribute 
to beaked whale strandings. Accordingly, to allow for scientific 
uncertainty regarding contributing causes of beaked whale strandings 
and the exact behavioral or physiological mechanisms that can lead to 
the ultimate physical effects (stranding and/or death), the Navy has 
requested authorization for (and NMFS is proposing authorizing) take, 
by injury or mortality. Although the Navy has requested take by injury 
or mortality of 10 beaked whales over the course of the 5-yr 
regulations, the Navy's model did not predict injurious takes of beaked 
whales and neither NMFS, nor the Navy anticipates that marine mammal 
strandings or mortality will result from the operation of MFAS during 
Navy exercises within the MIRC.

Effects on Marine Mammal Habitat

    The Navy's proposed training exercises could potentially affect 
marine mammal habitat through the introduction of pressure, sound, and 
expendable materials into the water column, which in turn could impact 
prey species of marine mammals, or cause bottom disturbance or changes 
in water quality. Each of these components was considered in the MIRC 
DEIS and was determined by the Navy to have no significant or long term 
effect on marine mammal habitat. Based on the information below and the 
supporting information included in the Navy's DEIS, NMFS has 
preliminarily determined that the MIRC training activities will not 
have significant or long term impacts on marine mammal 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. Marine mammals may be temporarily displaced 
from areas where Navy training is occurring, but the area will likely 
be utilized again after the activities have ceased. A summary of the 
conclusions are included in subsequent sections.

Effects on Food Resources

Fish
    The Navy's DEIS includes a detailed discussion of the effects of 
active sonar on marine fish. In summary, studies have indicated that 
acoustic communication and orientation of fish may be restricted by 
anthropogenic sound in their environment. However, the vast majority of 
fish species studied to date are hearing generalists and cannot hear 
sounds above 500 to 1,500 Hz (0.5 to 1.5 kHz) (depending upon the 
species). Therefore, these fish species are not likely to be affected 
behaviorally from higher frequency sounds such as MFAS/HFAS. Moreover, 
even those marine species that may hear above 1.5 kHz, such as a few 
sciaenids and the clupeids (and relatives), have relatively poor 
hearing above 1.5 kHz as compared to their hearing sensitivity at lower 
frequencies, so it is likely that the fish will only actually hear the 
sounds if the fish and source were fairly close to one another. 
Finally, since the vast majority of sounds that are of biological 
relevance to fish are below 1 kHz (e.g., Zelick et al., 1999; Ladich 
and Popper, 2004), even if a fish detects a mid- or high-frequency 
sound, these sounds will not likely mask detection of lower frequency 
biologically relevant sounds. Thus, based on the available information, 
a reasonable conclusion is that there will be few, and more likely no, 
impacts on the behavior of fish from active sonar.
    Though mortality has been shown to occur in one species, a hearing 
specialist, as a result of exposure to non-impulsive sources, the 
available evidence does not suggest that exposures such as those 
anticipated from MFAS/HFAS would result in significant fish mortality 
on a population level. The mortality that was observed was considered 
insignificant in light of natural daily mortality rates. Experiments 
have shown that exposure to loud sound can result in significant 
threshold shifts in certain fish that are classified as hearing 
specialists (but not those classified as hearing generalists). 
Threshold shifts are temporary, and considering the best available 
data, no data exist that demonstrate any long-term negative effects on 
marine fish from underwater sound associated with active sonar 
activities. Further, while fish may respond behaviorally to mid-
frequency sources, this behavioral modification is only expected to be 
brief and not biologically significant.
    There are currently no well-established thresholds for estimating 
effects to fish from explosives other than mortality models. Fish that 
are located in the water column, in proximity to the source of 
detonation could be injured, killed, or disturbed by the impulsive 
sound and possibly temporarily leave the area. Continental Shelf Inc. 
(2004) summarized a few studies conducted to determine effects 
associated with removal of offshore structures (e.g., oil rigs) in the 
Gulf of Mexico. Their findings revealed that at very close range, 
underwater explosions are lethal to most fish species regardless of 
size, shape, or internal anatomy. For most situations, cause of death 
in fishes has been massive organ and tissue damage and internal 
bleeding. At longer range, species with gas-filled swimbladders (e.g., 
snapper, cod, and striped bass) are more susceptible than those without 
swimbladders (e.g., flounders, eels). Studies also suggest that larger 
fishes are generally less susceptible to death or injury than small 
fishes. Moreover, elongated forms that are round in cross section are 
less at risk than deep-bodied forms; and orientation of fish relative 
to the shock wave may affect the extent of injury. Open water pelagic 
fish (e.g., mackerel) also seem to be less affected than reef fishes. 
The results of most studies are dependent upon specific biological, 
environmental, explosive, and data recording factors.
    The huge variations in the fish population, including numbers, 
species, sizes, and orientation and range from the detonation point, 
make it very difficult to accurately predict mortalities at any 
specific site of detonation. Most fish species experience a large 
number of natural mortalities, especially during early life-stages, and 
any small level of mortality caused by the MIRC training exercises 
involving explosives will likely be insignificant to the population as 
a whole.
Invertebrates
    Very little is known about sound detection and use of sound by 
invertebrates (see Budelmann 1992a, b, Popper et al., 2001 for 
reviews). The limited data show that some crabs are able to detect 
sound, and there has been the suggestion that some other groups of 
invertebrates are also able to detect sounds. In addition, cephalopods 
(octopus and squid) and decapods (lobster, shrimp, and crab) are 
thought to sense low-frequency sound (Budelmann, 1992b). Packard et al.

[[Page 53856]]

(1990) reported sensitivity to sound vibrations between 1-100 Hz for 
three species of cephalopods. McCauley et al. (2000) found evidence 
that squid exposed to seismic airguns show a behavioral response 
including inking. However, these were caged animals, and it is not 
clear how unconfined animals may have responded to the same signal and 
at the same distances used. In another study, Wilson et al. (2007) 
played back echolocation clicks of killer whales to two groups of squid 
(Loligo pealeii) in a tank. The investigators observed no apparent 
behavioral effects or any acoustic debilitation from playback of 
signals up to 199 to 226 dB re 1 [mu]Pa. It should be noted, however, 
that the lack of behavioral response by the squid may have been because 
the animals were in a tank rather than being in the wild. In another 
report on squid, Guerra et al. (2004) claimed that dead giant squid 
turned up around the time of seismic airgun operations off of Spain. 
The authors suggested, based on analysis of carcasses, that the damage 
to the squid was unusual when compared to other dead squid found at 
other times. However, the report presents conclusions based on a 
correlation to the time of finding of the carcasses and seismic 
testing, but the evidence in support of an effect of airgun activity 
was totally circumstantial. Moreover, the data presented showing damage 
to tissue is highly questionable since there was no way to 
differentiate between damage due to some external cause (e.g., the 
seismic airgun) and normal tissue degradation that takes place after 
death, or due to poor fixation and preparation of tissue. To date, this 
work has not been published in peer reviewed literature, and detailed 
images of the reportedly damaged tissue are also not available.
    In summary, baleen whales feed on the aggregations of krill and 
small schooling fish, while toothed whales feed on epipelagic, 
mesopelagic, and bathypelagic fish and squid. As summarized above and 
in the MIRC EIS/OEIS in more detail, potential impacts to marine mammal 
food resources within the MIRC is negligible given both lack of hearing 
sensitivity to mid-frequency sonar, the very geographic and spatially 
limited scope of most Navy at sea activities including underwater 
detonations, and the high biological productivity of these resources. 
No short or long term effects to marine mammal food resources from Navy 
activities are anticipated within the MIRC.

Military Expendable Material

    Marine mammals are subject to entanglement in expended materials, 
particularly anything incorporating loops or rings, hooks and lines, or 
sharp objects. Most documented cases of entanglements occur when whales 
encounter the vertical lines of fixed fishing gear. This section 
summarizes the potential effects of expended materials on marine 
mammals. Detailed discussion of military expendable material is 
contained within the MIRC EIS.
    The Navy endeavors to recover expended training materials. 
Notwithstanding, it is not possible to recover all training materials, 
and some may be encountered by marine mammals in the waters of the 
MIRC. Debris related to military activities that is not recovered 
generally sinks; the amount that might remain on or near the sea 
surface is low, and the density of such expendable materials in the 
MIRC would be very low. Types of training materials that might be 
encountered include: Parachutes of various types (e.g., those employed 
by personnel or on targets, flares, or sonobuoys); torpedo guidance 
wires, torpedo ``flex hoses;'' cable assemblies used to facilitate 
target recovery; sonobuoys; and EMATT.
    Entanglement in military expendable material was not cited as a 
source of injury or mortality for any marine mammals recorded in a 
large marine mammal and sea turtle stranding database for California 
waters, an area with much higher density of marine mammals. Therefore 
as discussed in the MIRC EIS, expendable material is highly unlikely to 
directly affect marine mammal species or potential habitat within the 
MIRC.
    NMFS Office of Habitat Conservation is working with the Navy to 
better identify the potential risks of expended materials from the Navy 
activities as they relate to Essential Fish Habitat. These effects are 
indirectly related to marine mammal habitat, but based on the extent of 
the likely effects described in the Navy's DEIS, NMFS' Office of 
Protected Resources has preliminarily determined that they will not 
result in significant impacts to marine mammal habitat. The EFH 
discussions between Navy and NMFS' Office of Habitat Conservation will 
further inform the marine mammal habitat analysis in the final rule.

Water Quality

    The MIRC EIS/OEIS analyzed the potential effects to water quality 
from sonobuoy, ADCs, and Expendable Mobile Acoustic Training Target 
(EMATT) batteries; explosive packages associated with the explosive 
source sonobuoy (AN/SSQ-110A), and Otto Fuel (OF) II combustion 
byproducts associated with torpedoes. Expendable bathythermographs do 
not have batteries and were not included in the analysis. In addition, 
sonobuoys were not analyzed since, once scuttled, their electrodes are 
largely exhausted during use and residual constituent dissolution 
occurs more slowly than the releases from activated seawater batteries. 
As such, only the potential effects of batteries and explosions on 
marine water quality in and surrounding the sonobuoy training area were 
completed. The Navy determined that there would be no significant 
effect to water quality from seawater batteries, lithium batteries, and 
thermal batteries associated with scuttled sonobuoys.
    ADCs and EMATTs use lithium sulfur dioxide batteries. The 
constituents in the battery react to form soluble hydrogen gas and 
lithium dithionite. The hydrogen gas eventually enters the atmosphere 
and the lithium hydroxide dissociates, forming lithium ions and 
hydroxide ions. The hydroxide is neutralized by the hydronium formed 
from hydrolysis of the acidic sulfur dioxide, ultimately forming water. 
Sulfur dioxide, a gas that is highly soluble in water, is the major 
reactive component in the battery. The sulfur ioxide ionizes in the 
water, forming bisulfite (HSO3) that is easily oxidized to sulfate in 
the slightly alkaline environment of the ocean. Sulfur is present as 
sulfate in large quantities (i.e., 885 milligrams per liter [mg/L]) in 
the ocean. Thus, it was determined that there would be no significant 
effect to water quality from lithium sulfur batteries associated with 
scuttled ADCs and EMATTs.
    Only a very small percentage of the available hydrogen fluoride 
explosive product in the explosive source sonobuoy (AN/SSQ-110A) is 
expected to become solubilized prior to reaching the surface and the 
rapid dilution would occur upon mixing with the ambient water. As such, 
it was determined that there would be no significant effect to water 
quality from the explosive product associated with the explosive source 
sonobuoy (AN/SSQ-110A).
    OF II is combusted in the torpedo engine and the combustion 
byproducts are exhausted into the torpedo wake, which is extremely 
turbulent and causes rapid mixing and diffusion. Combustion byproducts 
include carbon dioxide, carbon monoxide, water, hydrogen gas, nitrogen 
gas, ammonia, hydrogen cyanide, and nitrogen oxides. All of the 
byproducts, with the exception of

[[Page 53857]]

hydrogen cyanide, are below the EPA water quality criteria. Hydrogen 
cyanide is highly soluble in seawater and dilutes below the EPA 
criterion within 6.3 m (20.7 ft) of the torpedo. Therefore, it was 
determined there would be no significant effect to water quality as a 
result of OF II.

Analysis and Negligible Impact Determination

    Pursuant to NMFS' regulations implementing the MMPA, an applicant 
is required to estimate the number of animals that will be ``taken'' by 
the specified activities (i.e., takes by harassment only, or takes by 
harassment, injury, and/or death). This estimate informs the analysis 
that NMFS must perform to determine whether the activity will have a 
``negligible impact'' on the affected species or stock. Level B 
(behavioral) harassment occurs at the level of the individual(s) and 
does not assume any resulting population-level consequences, though 
there are known avenues through which behavioral disturbance of 
individuals can result in population-level effects (for example: pink-
footed geese (Anser brachyrhynchus) in undisturbed habitat gained body 
mass and had about a 46-percent reproductive success compared with 
geese in disturbed habitat (being consistently scared off the fields on 
which they were foraging) which did not gain mass and has a 17-percent 
reproductive success). A negligible impact finding is based on the lack 
of likely adverse effects on annual rates of recruitment or survival 
(i.e., population-level effects). An estimate of the number of Level B 
harassment takes, alone, is not enough information on which to base an 
impact determination. In addition to considering estimates of the 
number of marine mammals that might be ``taken'' through behavioral 
harassment, NMFS must consider other factors, such as the likely nature 
of any responses (their intensity, duration, etc.), the context of any 
responses (critical reproductive time or location, migration, etc.), as 
well as the number and nature of estimated Level A Harassment takes, 
the number of estimated mortalities, and effects on habitat. Generally 
speaking, and especially with other factors being equal, the Navy and 
NMFS anticipate more severe effects from takes resulting from exposure 
to higher received levels (though this is in no way a strictly linear 
relationship throughout species, individuals, or circumstances) and 
less severe effects from takes resulting from exposure to lower 
received levels.
    The Navy's specified activities have been described based on best 
estimates of the number of MFAS/HFAS hours that the Navy will conduct. 
The exact number of hours (or torpedoes, or pings, whatever unit the 
source is estimated in) may vary from year to year, but will not exceed 
the 5-year total indicated in Table 8 (by multiplying the yearly 
estimate by 5) by more than 10%. NMFS estimates that a 10-percent 
increase in active sonar hours (torpedoes, pings, etc.) would result in 
approximately a 10-percent increase in the number of takes, and we have 
considered this possibility and the effect of the additional active 
sonar use in our analysis.
    Taking the above into account, considering the sections discussed 
below, and dependent upon the implementation of the proposed mitigation 
measures, NMFS has preliminarily determined that Navy training 
exercises utilizing MFAS/HFAS and underwater detonations will have a 
negligible impact on the marine mammal species and stocks present in 
the MIRC Range Complex.

Behavioral Harassment

    As discussed in the Potential Effects of Exposure of Marine Mammals 
to MFAS/HFAS and illustrated in the conceptual framework, marine 
mammals can respond to MFAS/HFAS in many different ways, a subset of 
which qualify as harassment (see Behavioral Harassment Section). One 
thing that the take estimates do not take into account is the fact that 
most marine mammals will likely avoid strong sound sources to one 
extent or another. Although an animal that avoids the sound source will 
likely still be taken in some instances (such as if the avoidance 
results in a missed opportunity to feed, interruption of reproductive 
behaviors, etc.) in other cases avoidance may result in fewer instances 
of take than were estimated or in the takes resulting from exposure to 
a lower received level than was estimated, which could result in a less 
severe response. For MFAS/HFAS, the Navy provided information (Table 9) 
estimating the percentage of the total takes that will occur within the 
10-dB bins (without considering mitigation or avoidance) that are 
within the received levels considered in the risk continuum and for TTS 
and PTS. This table applies specifically to AN/SQS-53C hull-mounted 
active sonar (the most powerful source), with less powerful sources the 
percentages would increase slightly in the lower received levels and 
correspondingly decrease in the higher received levels. 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.

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    Because the Navy has only been monitoring specifically to discern 
the effects of MFAS/HFAS on marine mammals since approximately 2006, 
and because of the overall data gap regarding the effects of MFAS/HFAS 
on marine mammals, not a lot is known regarding how marine mammals in 
the MIRC will respond to MFAS/HFAS. For the one major exercise (Valiant 
Shield, 2007) for which NMFS has received a monitoring report, no 
instances of obvious behavioral disturbance were observed by the Navy 
watchstanders in the 25 marine mammal sightings of 235 animals. The 
Navy has also submitted reports from more than 60 major exercises 
conducted in the Southern California Range Complex, the Hawaii Range 
Complex, and off the Atlantic Coast, that similarly indicate no 
observed behavioral disturbance 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.) 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.
    In addition to the monitoring that will be required pursuant to 
these regulations and any corresponding LOAs, which is specifically 
designed to help us better understand how marine mammals respond to 
sound, the Navy and NMFS have developed, funded, and begun conducting a 
controlled exposure experiment with beaked whales in the Bahamas 
(results of first year discussed in previous sections, 2008 results not 
yet available). Separately, the Navy and NMFS conducted an 
opportunistic tagging experiment with several species of marine mammals 
in the area of the 2008 Rim of the Pacific training exercises in the 
HRC, for which the results are still being analyzed.

Diel Cycle

    As noted previously, many animals perform vital functions, such as 
feeding, resting, traveling, and socializing on a diel cycle (24-hr 
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 the fact that potential 
behavioral responses to MFAS/HFAS that fall into the category of 
harassment could range in severity. By definition, takes by behavioral 
harassment involve the 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 hours or be repeated in 
subsequent days. As indicated in table 2, with the exception of the 
major exercises (either 1 multi-strike group exercise annually, or 1 
Joint Expeditionary exercise and 1-4 MAGTFs annually), which last 
approximately 10 days, the rest of the sonar exercises conducted in the 
MIRC are 8 hours in duration or shorter. Additionally, vessels with 
hull-mounted active sonar are typically moving at speeds of 10-14 
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 are not expected to be exposed to MFAS/HFAS at levels 
or for a duration likely to result in a significant response that would 
then last for more than one day or on successive days. With the 
exception of SINKEXs, the planned explosive exercises are also 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. Although SINKEXs may last 
for up to 48 hours, only 2 are planned annually, they are stationary 
and conducted in deep, open water (where fewer marine mammals would 
typically be expected to be randomly encountered), and they have a 
rigorous monitoring and shutdown protocol, all of which make it 
unlikely that individuals would be

[[Page 53859]]

exposed to the exercise for extended periods or in consecutive days.

TTS

    NMFS and the Navy have estimated that approximately 1300 individual 
marine mammals (totaled from all affected species), may sustain some 
level of TTS from MFAS/HFAS annually. 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. Table 8 indicates the estimated number of animals that 
might sustain TTS from exposure to MFAS/HFAS. The TTS sustained by an 
animal is primarily classified by three characteristics:
    <bullet> Frequency--Available data (of mid-frequency hearing 
specialists exposed to mid to high frequency sounds--Southall et al., 
2007) suggest that most TTS occurs in the frequency range of the source 
up to one octave higher than the source (with the maximum TTS at 
[frac12] octave above). The more MF powerful sources used (the two 
hull-mounted MFAS sources and the DICASS sonobuoys) have center 
frequencies between 3.5 and 8 kHz and the other unidentified MF sources 
are, by definition, less than 10 kHz, which suggests that TTS induced 
by any of these MF sources would be in a frequency band somewhere 
between approximately 2 and 20 kHz. There are fewer hours of HF source 
use and the sounds would attenuate more quickly, plus they have lower 
source levels, but if an animal were to incur TTS from these sources, 
it would cover a higher frequency range (sources are between 20 and 100 
kHz, which means that TTS could range up to 200 kHz; however, HF 
systems are typically used less frequently and for shorter time periods 
than surface ship and aircraft MF systems, so TTS from these sources is 
even less likely). TTS from explosives would be broadband. Tables 5a 
and 5b summarize the vocalization data for each species.
    <bullet> 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 
(> 6 dB) is 195 dB (SEL), which might be received at distances of up to 
140 m from the most powerful MFAS source, the AN/SQS-53 (the maximum 
ranges to TTS from other sources would be less, as modeled for MIRC). 
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 watchstanders 
and the nominal speed of an active sonar vessel (10-12 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-sec exposure to a 20 kHz 
source (MFAS emits a 1-s ping 2 times/minute).
    <bullet> 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 MIRC, 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 the 
majority would be far less severe because of short duration of the 
majority of the exercises and the speed of a typical vessel), if that. 
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 level) would 
not usually span the entire frequency range of one vocalization type, 
much less span all types of vocalizations (see Tables 5a and 5b). If 
impaired, marine mammals would typically be aware of their impairment 
and implement behaviors to compensate for it (see Communication 
Impairment Section), though these compensations may incur energetic 
costs.

Acoustic Masking or Communication Impairment

    Table 5 is also informative regarding the nature of the masking or 
communication impairment that could potentially occur from MFAS (again, 
center frequencies are 3.5 and 7.5 kHz for the two types of hull-
mounted active sonar). However, 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 
pings last on average one second and occur about once every 24-30 
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 10s of micro seconds. 
For hull-mounted active sonar, though some of the vocalizations that 
marine mammals make are less than one second long, there is only a 1 in 
24 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

    The Navy's model estimated that one pantropical dolphin and one 
sperm whale would be exposed to levels of MFAS/HFAS that would result 
in PTS. This estimate does not take into consideration either the 
mitigation measures, the likely avoidance behaviors of some of the 
animals exposed, the distance from the sonar dome of a surface vessel 
within which an animal would have to be exposed to incur PTS (10 m), 
and the nominal speed of a surface vessel engaged in ASW exercises. 
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.

[[Page 53860]]

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 be 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 and indicated that they are capable of effectively 
monitoring a 1000-meter (1093-yd) safety zone at night using night 
vision goggles, infrared cameras, and passive acoustic monitoring.
    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 10-12 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. While NMFS believes it is very unlikely that a pantropical 
dolphin or sperm whale will incur PTS from exposure to MFAS/HFAS, the 
Navy has requested authorization to take one each by Level A 
Harasssment and therefore, NMFS has considered this possibility in our 
analysis.
    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 mechanisms of this potential response, behavioral 
or physiological, are 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. While these features certainly 
do not define the only factors that can contribute to a stranding, and 
while they need not all be present in their aggregate to increase the 
likelihood of a stranding, it is worth noting that they are not all 
present in the MIRC, which does have a strong surface duct present much 
of the time, but does not have bathymetry or constricted channels of 
the type that have been present in the sonar-associated strandings. 
Additionally, 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 
suggest that the probability is small that this will occur. 
Additionally, 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. Though NMFS does not 
expect it to occur, because of the uncertainty surrounding the 
mechanisms that link exposure to MFAS to stranding (especially in 
beaked whales), NMFS is proposing to authorize the injury or mortality 
of 10 beaked whales over the course of the 5-yr regulations.

60 Years of Navy Training Exercises Using MFAS/HFAS in the MIRC Range 
Complex

    The Navy has been conducting MFAS/HFAS training exercises in the 
MIRC Range Complex for over 60 years. Although limited monitoring 
specifically in conjunction with training exercises to determine the 
effects of active sonar and explosives on marine mammals has not been 
conducted by the Navy in the past in the MIRC and the symptoms 
indicative of potential acoustic trauma were not as well recognized 
prior to the mid-nineties, people have been collecting stranding data 
in the MIRC Range Complex for approximately 4 years. Though not all 
dead or injured animals are expected to end up on the shore (some may 
be eaten or float out to sea), one might expect that if marine mammals 
were being harmed by the Navy training exercises with any regularity, 
more evidence would have been detected.

Species-Specific Analysis

    In the discussions below, the ``acoustic analysis'' refers to the 
Navy's analysis, which includes the use of several models and other 
applicable calculations as described in the Estimates of Potential 
Marine Mammal Exposure section. The numbers predicted by the ``acoustic 
analysis'' are based on a uniform and stationary distribution of marine 
mammals and do not take into consideration the implementation of 
mitigation measures or potential avoidance behaviors of marine mammals, 
and therefore, are likely overestimates of potential exposures to the 
indicated thresholds (PTS, TTS, behavioral harassments).

Blue Whale (MMPA Depleted/ESA-Listed)

    Acoustic analysis predicts that 130 exposures of blue whales to 
MFAS/HFAS at levels likely to result in Level B harassment will occur, 
and that 0 exposures to explosives will occur. This estimate represents 
the total number of takes and not necessarily the number of individuals 
taken, as a single individual may be taken multiple times over the 
course of a year. These Level B takes are anticipated to be primarily 
in the form of behavioral disturbance as described in the Definition of 
Harassment: Level B Harassment section, although two TTS takes are also 
estimated. However, it is unlikely that any blue whales will incur TTS 
because of: the distance within which they would have to approach the 
MFAS source (approximately 140 m for the most powerful source for TTS), 
the fact that many animals will likely avoid active sonar sources to 
some degree, and the likelihood that Navy monitors would detect these 
animals prior to an approach within this distance (given their large 
size, average group size (2-3), and pronounced vertical blow) and 
implement active sonar powerdown or shutdown. Of note, blue whale 
vocalizations are in the 12 to 400 Hz range with dominant energy in the 
12 to 25 Hz range, which suggests that blue whale hearing may be more 
sensitive in this frequency range. Thus, frequencies in the MFAS range 
(1-10 kHz) are predicted to lie closer to the periphery of their 
hearing, which suggests that adverse impacts resulting from exposure to 
MFAS may be fewer than modeled.
    Blue whales have not actually been seen in the MIRC and the most 
appropriate population estimate is the one for the North Pacific, which 
estimates a minimum of 3,300 whales. Like most baleen whales, blue 
whales would most likely feed in the north in the summer and head 
southward (potentially MIRC) in the cooler months. Relative to the 
population size, this activity is anticipated to result only in a 
limited number of level B harassment takes. The MIRC activities are not 
expected to occur in an area/time of specific importance for 
reproduction, feeding, or other known critical behaviors. The blue 
whales' large size and detectability makes it unlikely that these 
animals would be exposed to the higher levels of sound expected to 
result in more severe effects. Consequently, the activities are not 
expected to adversely impact rates of recruitment or survival of blue 
whales. Based on the general information contained in the Negligible 
Impact Analysis section and this species-specific summary of the

[[Page 53861]]

effects of the takes, NMFS has preliminarily determined that the Navy's 
specified activities will have a negligible impact on this species.

Fin Whale (MMPA Depleted/ESA-Listed)

    Acoustic analysis predicts that 182 exposures of fin whales to 
MFAS/HFAS at sound levels likely to result in Level B harassment will 
occur, and that 0 exposures to explosives will occur. This estimate 
represents the total number of takes and not necessarily the number of 
individuals taken, as a single individual may be taken multiple times 
over the course of a year. These Level B takes are anticipated to be 
primarily in the form of behavioral disturbance as described in the 
Definition of Harassment: Level B Harassment section, although two TTS 
takes are also estimated. However, it is unlikely that any fin whales 
will incur TTS because of: The distance within which they would have to 
approach the MFAS source (approximately 140 m for the most powerful 
source for TTS), the fact that many animals will likely avoid active 
sonar sources to some degree, and the likelihood that Navy monitors 
would detect these animals prior to an approach within this distance 
(given their large size, average group size (3), and pronounced 
vertical blow) and implement active sonar powerdown or shutdown. Of 
note, fin whale vocalizations are in the 15-750 Hz range with the 
majority below 70 Hz, which suggests that fin whale hearing may be more 
sensitive in this frequency range. Thus, frequencies in the MFAS range 
(1-10 kHz) are predicted to lie closer to the periphery of their 
hearing, which suggests that adverse impacts resulting from exposure to 
MFAS may be fewer than modeled.
    Fin whales have not actually been seen in the MIRC and the most 
appropriate population estimate is the one for the North Pacific, which 
estimates 14,620-18,630 whales. Relative to the population size, this 
activity is anticipated to result only in a limited number of level B 
harassment takes. In the northern hemisphere, fin whales migrate 
seasonally from high Arctic feeding areas in the summer to low latitude 
breeding and calving areas in the winter. The MIRC activities are not 
expected to occur in an area/time of specific importance for 
reproduction, feeding, or other known critical behaviors. The fin 
whales' large size and detectability makes it unlikely that these 
animals would be exposed to the higher levels of sound expected to 
result in more severe effects. Consequently, the activities are not 
expected to adversely impact rates of recruitment or survival of fin 
whales. Based on the general information contained in the Negligible 
Impact Analysis section and this species-specific summary of the 
effects of the takes, NMFS has preliminarily determined that the Navy's 
specified activities will have a negligible impact on this species.

Sei Whale (MMPA Depleted/ESA-Listed)

    Acoustic analysis predicts that 325 exposures of sei whales to 
MFAS/HFAS at sound levels likely to result in Level B harassment will 
occur, and that 0 exposures to explosives will occur. This estimate 
represents the total number of takes and not necessarily the number of 
individuals taken, as a single individual may be taken multiple times 
over the course of a year. These Level B takes are anticipated to be 
primarily in the form of behavioral disturbance as described in the 
Definition of Harassment: Level B Harassment section, although six TTS 
takes are also estimated. However, it is unlikely that any sei whales 
will incur TTS because of: The distance within which they would have to 
approach the MFAS source (approximately 140 m for the most powerful 
source for TTS), the fact that many animals will likely avoid active 
sonar sources to some degree, and the likelihood that Navy monitors 
would detect these animals prior to an approach within this distance 
(given their large size, average group size (3), and pronounced 
vertical blow) and implement active sonar powerdown or shutdown.
    The most appropriate population estimate for the sei whale is the 
one for the North Pacific, which estimates 9,110 whales. Relative to 
the population size, this activity is anticipated to result only in a 
limited number of level B harassment takes. Sei whales are generally 
thought to feed in the summer in the north and spend winters in warm 
temperate or sub-tropical areas. The MIRC activities are not expected 
to occur in an area/time of specific importance for reproduction, 
feeding, or other known critical behaviors. The sei whales' large size 
and detectability makes it unlikely that these animals would be exposed 
to the higher levels of sound expected to result in more severe 
effects. Consequently, the activities are not expected to adversely 
impact rates of recruitment or survival of sei whales. Based on the 
general information contained in the Negligible Impact Analysis section 
and this species-specific summary of the effects of the takes, NMFS has 
preliminarily determined that the Navy's specified activities will have 
a negligible impact on this species.

Humpback Whale (MMPA Depleted/ESA-Listed)

    Acoustic analysis predicts that 804 exposures of humpback whales to 
MFAS/HFAS at sound levels likely to result in Level B harassment will 
occur. This estimate represents the total number of takes and not 
necessarily the number of individuals taken, as a single individual may 
be taken multiple times over the course of a year. These Level B takes 
are anticipated to be primarily in the form of behavioral disturbance 
as described in the Definition of Harassment: Level B Harassment 
section, although ten TTS takes are also estimated. However, it is 
unlikely that any humpback whales will incur TTS because of: the 
distance within which they would have to approach the MFAS source 
(approximately 140 m for the most powerful source for TTS), the fact 
that many animals will likely avoid active sonar sources to some 
degree, and the likelihood that Navy monitors would detect these 
animals prior to an approach within this distance (given their large 
size and gregarious nature) and implement active sonar powerdown or 
shutdown.
    The acoustic analysis further predicts that 1 humpback whale would 
be exposed to levels of pressure and/or energy from explosive 
detonations that would result in Level B harassment by TTS. NMFS 
believes that this is unlikely because of: (1) The distance within 
which they would have to approach the explosive source; and, (2) the 
likelihood that Navy monitors would, during pre- or during exercises 
monitoring, detect these large, gregarious animals prior to an approach 
within this distance and require a delay of the exercise.
    The current estimate for the North Pacific is 18,302 humpback 
whales. Relative to the population size, this activity is anticipated 
to result only in a limited number of level B harassment takes. 
Humpback whales are generally thought to feed in the summer in the 
north and spend winters in warm temperate or sub-tropical areas. The 
MIRC activities are not expected to occur in an area/time of specific 
importance for reproduction, feeding, or other known critical 
behaviors. The humpback whales' large size and detectability makes it 
unlikely that these animals would be exposed to the higher levels of 
sound expected to result in more severe effects. Consequently, the 
activities are not expected to adversely impact rates of recruitment or 
survival of humpback whales. Based on the general information contained 
in the Negligible Impact Analysis section and this species-specific 
summary of the

[[Page 53862]]

effects of the takes, NMFS has preliminarily determined that the Navy's 
specified activities will have a negligible impact on this species.

Bryde's Whale

    Acoustic analysis predicts that 457 exposures of Bryde's whales to 
MFAS/HFAS at sound levels likely to result in Level B harassment will 
occur, and that 0 exposures to explosives will occur. This estimate 
represents the total number of takes and not necessarily the number of 
individuals taken, as a single individual may be taken multiple times 
over the course of a year. These Level B takes are anticipated to be 
primarily in the form of behavioral disturbance as described in the 
Definition of Harassment: Level B Harassment section, although 8 TTS 
takes are also estimated. However, it is unlikely that any fin whales 
will incur TTS because of: the distance within which they would have to 
approach the MFAS source (approximately 140 m for the most powerful 
source for TTS), the fact that many animals will likely avoid active 
sonar sources to some degree, and the likelihood that Navy monitors 
would detect these animals prior to an approach within this distance 
(given their large size and pronounced blow) and implement active sonar 
powerdown or shutdown.
    Bryde's whales are found worldwide in tropical and temperate 
waters. There are no current estimates of Bryde's whale in the Pacific 
but based on the MISTCS survey, abundance in MIRC is about 233 animals. 
Historical records show a consistent presence of Bryde's whales in the 
MIRC. Bryde's whales have been sighted with calves several times, but 
no regularly used reproductive areas have been identified. The Bryde's 
whales' large size and detectability makes it unlikely that these 
animals would be exposed to the higher levels of sound expected to 
result in more severe effects. Consequently, the activities are not 
expected to adversely impact rates of recruitment or survival of 
Bryde's whales. Based on the general information contained in the 
Negligible Impact Analysis section and this species-specific summary of 
the effects of the takes, NMFS has preliminarily determined that the 
Navy's specified activities will have a negligible impact on this 
species.

Minke Whale

    Acoustic analysis predicts that 445 exposures of Minke whales to 
MFAS/HFAS at sound levels likely to result in Level B harassment will 
occur, and that 0 exposures to explosives will occur. This estimate 
represents the total number of takes and not necessarily the number of 
individuals taken, as a single individual may be taken multiple times 
over the course of a year. These Level B takes are anticipated to be 
primarily in the form of behavioral disturbance as described in the 
Definition of Harassment: Level B Harassment section, although 7 TTS 
takes are also estimated. It is somewhat unlikely that any fin whales 
will incur TTS because of: the distance within which they would have to 
approach the MFAS source (approximately 140 m for the most powerful 
source for TTS) and the fact that many animals will likely avoid active 
sonar sources to some degree. However, Minke whales are relatively 
cryptic at surface, making visual detection more difficult, although 
they are often detected acoustically.
    Minke whales are found in the North Atlantic and North Pacific from 
tropical to polar waters, although there are no current estimates of 
Minke whales in the Pacific. Minke whales were the most frequently 
detected species of baleen whales in the MISTCS (acoustically, not 
visually). The MIRC activities are not expected to occur in an area/
time of specific importance for reproduction, feeding, or other known 
critical behaviors. Consequently, the activities are not expected to 
adversely impact rates of recruitment or survival of Minke whales. 
Based on the general information contained in the Negligible Impact 
Analysis section and this species-specific summary of the effects of 
the takes, NMFS has preliminarily determined that the Navy's specified 
activities will have a negligible impact on this species.

Sperm Whale (MMPA Depleted/ESA-Listed)

    Acoustic analysis predicts that 817 exposures of sperm whales to 
MFAS/HFAS at sound levels likely to result in Level B harassment will 
occur. This estimate represents the total number of takes and not 
necessarily the number of individuals taken, as a single individual may 
be taken multiple times over the course of a year. These Level B takes 
are anticipated to be primarily in the form of behavioral disturbance 
as described in the Definition of Harassment: Level B Harassment 
section, although 10 TTS takes and 1 PTS (Level A Harassment) are also 
estimated and proposed for authorization. However, it is unlikely that 
any sperm whales will incur TTS or PTS because of: The distance within 
which they would have to approach the MFAS source (approximately 140 m 
for the most powerful source for TTS and 10 m for PTS), the fact that 
many animals will likely avoid active sonar sources to some degree, and 
the likelihood that Navy monitors would detect these animals prior to 
an approach within this distance (given their large size, pronounced 
blow, and mean group size of 7).
    The acoustic analysis further predicts that 9 sperm whales would be 
exposed to levels of pressure and/or energy from explosive detonations 
that would result in Level B harassment by TTS. NMFS believes that this 
is unlikely because of: (1) The distance within which they would have 
to approach the explosive source; and, (2) the likelihood that Navy 
monitors would, during pre- or during exercises monitoring, detect 
these animals for the reasons indicated above.
    Sperm whales occur throughout all ocean basins from equatorial to 
polar waters. Sperm whales are found throughout the North Pacific, but 
there are no current estimates of sperm whale abundance in the North 
Pacific, but based on the MISTCS survey, abundance in MIRC is about 705 
animals. The sperm whale was the most frequently sighted cetacean in 
the MISTCS and was acoustically detected 3 times more often than it was 
visually detected. Sperm whales are present year-round in MIRC and have 
been sighted with calves, although no regularly used reproductive areas 
have been identified. The Sperm whales' large size and detectability 
makes it unlikely that these animals would be exposed to the higher 
levels of sound expected to result in more severe effects. 
Consequently, the activities are not expected to adversely impact rates 
of recruitment or survival of sperm whales. Based on the general 
information contained in the Negligible Impact Analysis section and 
this species-specific summary of the effects of the takes, NMFS has 
preliminarily determined that the Navy's specified activities will have 
a negligible impact on this species.

Pygmy and Dwarf Sperm Whale

    Because of their similarity of appearance and cryptic behavior, 
these two species are difficult to differentiate in the field and are 
considered together. Acoustic analysis predicts that 6,677 exposures of 
pygmy or dwarf sperm whales to MFAS/HFAS at sound levels likely to 
result in Level B harassment will occur. This estimate represents the 
total number of takes and not necessarily the number of individuals 
taken, as a single individual may be taken multiple times over the 
course of a year. These Level B takes are anticipated to be primarily 
in the form of behavioral disturbance as described in the Definition of 
Harassment: Level B

[[Page 53863]]

Harassment section, although 103 TTS takes are also estimated. NMFS 
believes that it is unlikely that this number of pygmy or dwarf sperm 
whales will incur TTS because of the distance within which they would 
have to approach the MFAS source (approximately 140 m for the most 
powerful source for TTS) and the fact that many animals will likely 
avoid active sonar sources to some degree. However, the likelihood that 
Navy monitors would detect most of these animals at the surface prior 
to an approach within this distance is low because of their small size, 
non-gregarious nature, and cryptic behavior and profile. As mentioned 
above and indicated in Table 5, some pygmy or dwarf sperm whale 
vocalizations might overlap with the MFAS/HFAS TTS frequency range (2-
20 kHz) (although most of their vocalizations are anticipated to be in 
a higher frequency range), which could potentially 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 acoustic analysis further predicts that 6 pygmy or dwarf sperm 
whales would be exposed to levels of pressure and/or energy from 
explosive detonations that would result in Level B harassment by TTS, 
and 20 could be exposed to levels associated with behavioral 
disturbance.
    Pygmy and dwarf sperm whales occur in tropical and temperate 
latitudes worldwide, although there are no current estimates of these 
whales in the Pacific or MIRC. The MIRC activities are not expected to 
occur in an area/time of specific importance for reproduction, feeding, 
or other known critical behaviors. Consequently, the activities are not 
expected to adversely impact rates of recruitment or survival of dwarf 
or pygmy sperm whales. Based on the general information contained in 
the Negligible Impact Analysis section and this species-specific 
summary of the effects of the takes, NMFS has preliminarily determined 
that the Navy's specified activities will have a negligible impact on 
this species.

Beaked Whales

    Acoustic analysis predicts that 770 Blainville's beaked whales, 
3,611 Cuvier's beaked whales, 430 Ginkgo-toothed beaked whales, and 206 
Longman's beaked whales will be exposed to MFAS/HFAS at sound levels 
likely to result in Level B harassment. This estimate represents the 
total number of takes and not necessarily the number of individuals 
taken, as a single individual may be taken multiple times over the 
course of a year. These Level B takes are anticipated to be primarily 
in the form of behavioral disturbance as described in the Definition of 
Harassment: Level B Harassment section, although 12, 44, 7, and 2 
(respectively) TTS takes are also estimated. NMFS believes that it is 
unlikely that this number of beaked whales will incur TTS because of 
the distance within which they would have to approach the MFAS source 
(approximately 140 m for the most powerful source for TTS) and the fact 
that many animals will likely avoid active sonar sources to some 
degree. However, the likelihood that Navy monitors would detect most of 
these animals at the surface prior to an approach within this distance 
is low because of their deep-diving behavior and cryptic profile. As 
mentioned above and indicated in Table 5, some beaked whale 
vocalizations might overlap with the MFAS/HFAS TTS frequency range (2-
20 kHzge), which could potentially 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 acoustic analysis further predicts that 4 Cuvier's beaked 
whales would be exposed to levels of pressure and/or energy from 
explosive detonations that would result in Level B harassment by TTS, 
and 14 could be exposed to levels associated with behavioral 
disturbance.
    Cuvier's and Blainville's beaked whales are widespread throughout 
tropical and temperate latitudes worldwide, while Ginkgo-toothed and 
Longman's beaked whales are not well known, but thought to occur in the 
tropical and temperate waters of the Indo-Pacific. No abundance 
estimates are available for any of these species. The MIRC activities 
are not expected to occur in an area/time of specific importance for 
reproduction, feeding, or other known critical behaviors. Consequently, 
the activities are not expected to adversely impact rates of 
recruitment or survival of beaked whales. Based on the general 
information contained in the Negligible Impact Analysis section and 
this species-specific summary of the effects of the takes, NMFS has 
preliminarily determined that the Navy's specified activities will have 
a negligible impact on this species.

Social Pelagic Species (False/Pygmy Killer Whale, Killer Whale, Short-
Finned Pilot Whale, and Melon-Headed Whale)

    Acoustic analysis predicts that 1289 false killer whales, 230 
killer whales, 2854 melon-headed whales, 160 pygmy killer whales, and 
2274 short-finned pilot whales will be exposed to MFAS/HFAS at sound 
levels likely to result in Level B harassment. This estimate represents 
the total number of takes and not necessarily the number of individuals 
taken, as a single individual may be taken multiple times over the 
course of a year. These Level B takes are anticipated to be primarily 
in the form of behavioral disturbance as described in the Definition of 
Harassment: Level B Harassment section, although 23, 4, 46, 2, and 36 
(respectively) TTS takes are also estimated. However, it is unlikely 
that many individuals of these species will incur TTS because of: The 
distance within which they would have to approach the MFAS source 
(approximately 140 m for the most powerful source for TTS), the fact 
that many animals will likely avoid active sonar sources to some 
degree, and the likelihood that Navy monitors would detect these 
animals prior to an approach within this distance (given their 
gregarious nature and large group size) and implement active sonar 
powerdown or shutdown. As mentioned above and indicated in Table 5, 
vocalizations of these species might overlap with the MFAS/HFAS TTS 
frequency range (2-20 kHz), which could potentially temporarily 
decrease an animal's sensitivity to the calls of conspecifics or 
returning echolocation signals. However, 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 acoustic analysis further predicts that 2 melon-headed whales 
would be exposed to levels of pressure and/or energy from explosive 
detonations that would result in Level B harassment by TTS, and 6 could 
be exposed to levels associated with behavioral disturbance. NMFS 
believes that this is unlikely because of: (1) The distance within 
which they would have to approach the explosive source; and, (2) the 
likelihood that Navy monitors would, during pre- or during exercises 
monitoring, detect these large-grouped gregarious animals prior to an 
approach within this distance and require a delay of the exercise.
    These species all have large ranges, primarily tropical (melon-
headed and pygmy killer whales) and tropical/temperate (false killer 
and short-finned

[[Page 53864]]

pilot whales), although the killer whale is more abundant at higher 
latitudes. Abundance estimates are only available from the MISTCS and 
only for 3 species (melon-headed whales--2455, short-finned pilot 
whale--909, and false killer whale--637). The MIRC activities are not 
expected to occur in an area/time of specific importance for 
reproduction, feeding, or other known critical behaviors. Consequently, 
the activities are not expected to adversely impact rates of 
recruitment or survival of these social pelagic whales. Based on the 
general information contained in the Negligible Impact Analysis section 
and this species-specific summary of the effects of the takes, NMFS has 
preliminarily determined that the Navy's specified activities will have 
a negligible impact on these species.

Dolphins

    Acoustic analysis predicts that individuals of all 8 of the dolphin 
species present in the MIRC will be exposed to MFAS/HFAS at sound 
levels likely to result in Level B harassment some number of times (see 
Table 8). These estimates represent the total number of takes and not 
necessarily the number of individuals taken, as a single individual may 
be taken multiple times over the course of a year. These Level B takes 
are anticipated to be primarily in the form of behavioral disturbance 
as described in the Definition of Harassment: Level B Harassment 
section, although some number of TTS takes are also estimated for all 
species and one PTS take is predicted for a pantropical spotted 
dolphin. However, it is unlikely that many individuals of these species 
will incur TTS because of: the distance within which they would have to 
approach the MFAS source (approximately 140 m for the most powerful 
source for TTS), the fact that many animals will likely avoid active 
sonar sources to some degree, and the likelihood that Navy monitors 
would detect these animals prior to an approach within this distance 
(given their gregarious nature and large group size) and implement 
active sonar powerdown or shutdown. However, the Navy's proposed 
mitigation has a provision that allows the Navy to continue operation 
of MFAS if the animals are clearly bow-riding even after the Navy has 
initially maneuvered to try and avoid closing with the animals. Since 
these animals sometimes bow-ride they could potentially be exposed to 
levels associated with TTS as they approach or depart from bow-riding. 
As mentioned above and indicated in Table 5, vocalizations of these 
species might overlap with the MFAS/HFAS TTS frequency range (2-20 
kHz), which could potentially temporarily decrease an animal's 
sensitivity to the calls of conspecifics or returning echolocation 
signals. However, 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 acoustic analysis further predicts that several individuals of 
several species of dolphins would be exposed to levels of pressure and/
or energy from explosive detonations that would result in Level B 
harassment by TTS or behavioral harassment. NMFS believes that this is 
unlikely because of: (1) The distance within which they would have to 
approach the explosive source; and, (2) the likelihood that Navy 
monitors would, during pre- or during exercises monitoring, detect 
these large-grouped gregarious animals prior to an approach within this 
distance and require a delay of the exercise.
    These species all have large ranges, primarily tropical and 
tropical/temperate. Abundance estimates are only available from the 
MISTCS and only for 5 species (bottlenose dolphin--122, pantropical 
spotted dolphin--12,981, rough-toothed dolphin--166, spinner dolphin--
1803, and striped dolphin--3531). Three species were sighted with 
calves during the MISTCS, bottlenose dolphins, Risso's dolphins, and 
striped dolphins, however, no areas of regular use for breeding or 
calving have been identified.
    Spinner dolphins, which rest primarily during the day in relatively 
large groups, are known to consistently use certain areas (usually 
Bays) for this function. Because of this, they are a regular target for 
whalewatching boats or other members of the public interested in 
viewing or interacting with them, which could potentially put them at 
increased energetic risk if their resting cycles are repeatedly 
interrupted in a significant manner. There are several resting areas 
for spinner dolphins in the MIRC Study Area: Agat Bay, Bile/Tougan Bay, 
and Double Reef. These areas usually occur in clear, calm, shallow 
waters sheltered from prevailing tradewinds. NMFS and the Navy 
considered spinner dolphin resting areas in relation to areas where the 
Navy plans to conduct training activities, including the Agat Bay UNDET 
areas. The outermost edge of the resting areas extends out 
approximately .5 nm (900m) from shore, which is 4 nm (7.4km) away from 
the Agat Bay UNDET area. The estimated threshold range for TTS exposure 
from explosives ordnance used in the Agat Bay UNDET area is 
approximately .3nm (500m). Therefore, explosive activities conducted at 
this site are not expected to impact resting spinner dolphins. Unlike 
the UNDET areas for MIW, there are no areas specifically designated for 
ASW and SUW exercises. They are, however, all conducted at least 3nm 
(5.6km) away from shore and can occur anywhere throughout the 500,000nm 
\2\ MIRC Study Area. The Agat Bay, Bile/Tougan, and Double Reef resting 
areas extend aproximately .5nm, .4nm, and .3nm from shore. The TTS 
threshold distance for MFA ranges from 0 to 140m from the source and, 
therefore, spinner dolphins resting in these Bays are not expected to 
be exposed to levels associated with TTS. The received SPL level at 
2.5nm (4.6km), is between 160 and 170dB and there could be potential 
for some behavioral impacts if spinner dophins were resting in the area 
when ASW was conducted at the closest possible spot, however, due to 
the large size of the MIRC study area (over 500,000nm\2\), the 
probability that ASW training activities would be conducted in close 
proximity to any of the recognized resting areas when spinner dolphins 
are present is very low.
    The MIRC activities are not expected to occur in an area/time of 
specific importance for reproduction, feeding, or other known critical 
behaviors. Consequently, the activities are not expected to adversely 
impact rates of recruitment or survival of dolphins. Based on the 
general information contained in the Negligible Impact Analysis section 
and this species-specific summary of the effects of the takes, NMFS has 
preliminarily determined that the Navy's specified activities will have 
a negligible impact on these species.

Preliminary Determination

Negligible Impact

    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat and dependent 
upon the implementation of the mitigation and monitoring measures, NMFS 
preliminarily finds that the total taking from Navy training exercises 
utilizing MFAS/HFAS and underwater explosives in the MIRC will have a 
negligible impact on the affected species or stocks. NMFS has proposed 
regulations for these exercises that prescribe the means of effecting 
the least practicable adverse impact on marine mammals and their 
habitat and set forth requirements pertaining to the monitoring and 
reporting of that taking.

[[Page 53865]]

Subsistence Harvest of Marine Mammals

    NMFS has preliminarily determined that the issuance of 5-year 
regulations and subsequent LOAs for Navy training exercises in the MIRC 
would not have an unmitigable adverse impact on the availability of the 
affected species or stocks for subsistence use.
    As noted above, NMFS will consider all comments, suggestions and/or 
concerns submitted by the public during the proposed rulemaking comment 
period to help inform our final decision, particularly with respect to 
our negligible impact determination and the proposed mitigation and 
monitoring measures.

ESA

    There are five marine mammal species and two sea turtle species 
that are listed as endangered under the ESA with confirmed or possible 
occurrence in the study area: humpback whale, sei whale, fin whale, 
blue whale, sperm whale, hawksbill sea turtle and leatherback sea 
turtle. An additional three species of sea turtles are also listed as 
threatened under the ESA: green sea turtle, loggerhead sea turtle, and 
olive ridley sea turtle. The Navy has begun consultation with NMFS and 
the USFWS pursuant to section 7 of the ESA, and NMFS will also consult 
internally on the issuance of LOAS under section 101(a)(5)(A) of the 
MMPA for MIRC activities. Consultation will be concluded prior to a 
determination on the issuance of the final rule and an LOA.

NEPA

    NMFS has participated as a cooperating agency on the Navy's Draft 
Environmental Impact Statement (DEIS) for the MIRC, which was published 
on January 30, 2008. The Navy's DEIS is posted on NMFS' Web site: 
http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. NMFS 
intends to adopt the Navy's Final EIS (FEIS), if adequate and 
appropriate. Currently, we believe that the adoption of the Navy's FEIS 
will allow NMFS to meet its responsibilities under NEPA for the 
issuance of an LOA for MIRC. If the Navy's FEIS is deemed not to be 
adequate, NMFS would supplement the existing analysis to ensure that we 
comply with NEPA prior to the issuance of the final rule or LOA.

Classification

    This action does not contain any collection of information 
requirements for purposes of the Paperwork Reduction Act.
    The Office of Management and Budget has determined that this 
proposed rule is significant for purposes of Executive Order 12866.
    Pursuant to the Regulatory Flexibility Act, 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 Regulatory Flexibility 
Act 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 will be affected by this rulemaking, not a small 
governmental jurisdiction, small organization or small business, as 
defined by the Regulatory Flexibility Act (RFA). Any requirements 
imposed by a Letter of Authorization issued pursuant to these 
regulations, and any monitoring or reporting requirements imposed by 
these regulations, will 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, Transportation.

Samuel D. Rauch III,
Deputy 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

    1. The authority citation for part 218 continues to read as 
follows:

    Authority: 16 U.S.C. 1361 et seq.

Subparts D-K [Added and Reserved]

    2. Subparts D-K are added to part 218 and reserved.
    3. Subpart L is added to part 218 to read as follows:
Subpart L--Taking and Importing Marine Mammals; U.S. Navy's Mariana 
Islands Range Complex (MIRC)
Sec.
218.100 Specified activity and geographical area.
218.101 [Reserved]
218.102 Permissible methods of taking.
218.103 Prohibitions.
218.104 Mitigation.
218.105 Requirements for monitoring and reporting.
218.106 Applications for Letters of Authorization.
218.107 Letters of Authorization.
218.108 Renewal of Letters of Authorization and adaptive management.
218.109 Modifications to Letters of Authorization.

Subpart L--Taking and Importing Marine Mammals; U.S. Navy's Mariana 
Islands Range Complex (MIRC)


Sec.  218.100  Specified activity and geographical area.

    (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 occur 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 Mariana Islands Range Complex (MIRC) Study Area 
(as depicted in Figure 1-1 in the Navy's application for MIRC), which 
is bounded by a pentagon with the following five corners: 
16[deg]46'29.3376'' N. lat., 138[deg]00'59.835'' E. long.; 
20[deg]02'24.8094'' N. lat., 140[deg]10'13.8642'' E. long.; 20[deg] 3' 
27.5538'' N. lat., 149[deg] 17' 41.0388'' E. long.; 7[deg] 0' 30.0702'' 
N. lat., 149[deg] 16' 14.8542''E. long; and 6[deg] 59' 24.633'' N. lat, 
138[deg] 1' 29.7228'' E. long.
    (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) The use of the following mid-frequency active sonar (MFAS) 
sources, high frequency active sonar (HFAS) sources for U.S. Navy anti-
submarine warfare (ASW), in the amounts and in the locations indicated 
below (<plus-minus> 10%):
    (i) AN/SQS-53 (hull-mounted active sonar)--up to 10865 hours over 
the course of 5 years (an average of 2173 hours per year), with no more 
than 10% of this use in the winter;
    (ii) AN/SQS-56 (hull-mounted active sonar)--up to 705 hours over 
the course of 5 years (an average of 141 hours per year);
    (iii) AN/SSQ-62 (Directional Command Activated Sonobuoy System

[[Page 53866]]

(DICASS) sonobuoys)--up to 8270 sonobuoys over the course of 5 years 
(an average of 1654 sonobuoys per year)
    (iv) AN/AQS-22 (helicopter dipping sonar)--up to 2960 hours over 
the course of 5 years (an average of 592 hours per year);
    (v) AN/BQQ-10 (submarine hull-mounted sonar)--up to 60 hours over 
the course of 5 years (an average of 12 hours per year);
    (vi) MK-48, MK-46, or MK-54 (torpedoes)--up to 200 torpedoes over 
the course of 5 years (an average of 40 torpedoes per year);
    (vii) AN/SSQ-110 (IEER)--up to 530 buoys deployed over the course 
of 5 years (an average of 106 per year);
    (viii) AN/SSQ-125 (AEER)--up to 530 buoys deployed over the course 
of 5 years (an average of 106 per year);
    (ix) Range Pingers--up to 1400 hours over the course of 5 years (an 
average of 280 hours per year); and
    (x) PUTR Transponder--up to 1400 hours over the course of 5 years 
(an average of 280 hours per year).
    (2) The detonation of the underwater explosives indicated in 
paragraph (c)(2)(i) of this section conducted as part of the training 
events indicated in paragraph (c)(2)(ii) of this section:
    (i) Underwater Explosives:
    (A) 5'' Naval Gunfire (9.5 lbs);
    (B) 76 mm rounds (1.6 lbs);
    (C) Maverick (78.5 lbs);
    (D) Harpoon (448 lbs);
    (E) MK-82 (238 lbs);
    (F) MK-83 (574 lbs);
    (G) MK-84 (945 lbs);
    (H) MK-48 (851 lbs);
    (I) Demolition Charges (10 lbs);
    (J) AN/SSQ-110A (IEER explosive sonobuoy--5 lbs);
    (K) Hellfire (16.5lbs);
    (L) GBU 38/32/31.
    (ii) Training Events:
    (A) Gunnery Exercises (S-S GUNEX)--up to 60 exercises over the 
course of 5 years (an average of 12 per year);
    (B) Bombing Exercises (BOMBEX)--up to 20 exercises over the course 
of 5 years (an average of 4 per year);
    (C) Sinking Exercises (SINKEX)--up to 10 exercises over the course 
of 5 years (an average of 2 per year);
    (D) Extended Echo Ranging and Improved Extended Echo Ranging (EER/
IEER) Systems--up to 530 deployments over the course of 5 years (an 
average of 106 per year);
    (E) Demolitions--up to 50 over the course of 5 years (an average of 
10 per year); and
    (F) Missile exercises (A-S MISSILEX)--up to 10 exercises over the 
course of 5 years (an average of 2 per year).


Sec.  218.101  [Reserved]


Sec.  218.102  Permissible methods of taking.

    (a) Under Letters of Authorization issued pursuant to Sec. Sec.  
216.106 and 218.107 of this chapter, the Holder of the Letter of 
Authorization (hereinafter ``Navy'') may incidentally, but not 
intentionally, take marine mammals within the area described in Sec.  
218.100(b), provided the activity is in compliance with all terms, 
conditions, and requirements of these regulations and the appropriate 
Letter of Authorization.
    (b) The incidental take of marine mammals under the activities 
identified in Sec.  218.100(c) is limited to the following species, by 
the indicated method of take and the indicated number of times 
(estimated based on the authorized amounts of sound source operation):
    (1) Level B Harassment (+/-10% of the take estimate indicated 
below):
    (i) Mysticetes:
    (A) Humpback whale (Megaptera novaeangliae)--4025 (an average of 
805 annually);
    (B) Fin whale (Balaenoptera physalus)--910 (an average of 182 
annually);
    (C) Blue whale (Balaenoptera musculus)--650 (an average of 130 
annually);
    (D) Sei whale (Balaenoptera borealis)--1625 (an average of 325 
annually);
    (E) Minke whale (Balaenoptera acutorostrata)--2225 (an average of 
445 annually);
    (F) Bryde's whale (Balaenoptera edeni)--2285 (an average of 457 
annually); and
    (G) Unidentified Baleanopterid whales--360 (an average of 72 
annually)
    (ii) Odontocetes:
    (A) Sperm whales (Physeter macrocephalus)--4130 (an average of 826 
annually);
    (B) Killer whale (Orcinus orca)--1150 (an average of 230 annually);
    (C) Pygmy or dwarf sperm whales (Kogia breviceps or Kogia sima)--
33515 (an average of 6703 annually);
    (D) Blainville's beaked whales (Mesoplodon densirostris);--3850 (an 
average of 770 annually);
    (E) Cuvier's beaked whales (Ziphius cavirostris)--18135 (an average 
of 3627 annually);
    (F) Ginkgo-toothed beaked whales (Mesoplodon ginkgodens)--2150 (an 
average of 430 annually);
    (G) Longman's beaked whale (Indopacetus pacificus)--1030 (an 
average of 206 annually);
    (H) Short-finned pilot whale (Globicephala macrorynchus)--11370 (an 
average of 2274 annually);
    (I) Melon-headed whale (Peponocephala electra)--14310 (an average 
of 2862 annually)
    (J) Pygmy killer whale (Feresa attenuata)--800 (an average of 160 
annually);
    (K) False killer whale (Pseudorca crassidens)--6445 (an average of 
1289 annually);
    (L) Striped dolphin (Stenella coeruleoalba)--44280 (an average of 
8856 annually);
    (M) Short-beaked common dolphin (Delphinus delphis)--4715 (an 
average of 943 annually);
    (N) Risso's dolphin (Grampus griseus)--33855 (an average of 6771 
annually);
    (O) Bottlenose dolphin (Tursiops truncates)--855 (an average of 171 
annually);
    (P) Fraser's dolphin (Lagenodelphis hosei)--23065 (an average of 
4613 annually);
    (Q) Pantropical spotted dolphin (Stenella attenuata)--162465 (an 
average of 32493 annually);
    (R) Rough-toothed dolphin (Steno bredanensis)--1205 (an average of 
241 annually);
    (S) Spinner dolphin (Stenella longirostris)--10715 (an average of 
2143 annually); and
    (T) Unidentified delphinid--7690 (an average of 1538 annually).
    (2) Level A Harassment:
    (i) Sperm whale--5 (an average of 1 annually);
    (ii) Pantropical spotted dolphin--5 (an average of 1 annually);
    (3) Level A Harassment and/or mortality of no more than 10 beaked 
whales (total), of any of the species listed in Sec.  
218.102(c)(1)(ii)(D) through (G) over the course of the 5-year 
regulations.


Sec.  218.103  Prohibitions.

    No person in connection with the activities described in Sec.  
218.100 may:
    (a) Take any marine mammal not specified in Sec.  218.102(c);
    (b) Take any marine mammal specified in Sec.  218.102(c) other than 
by incidental take as specified in Sec.  218.102(c)(1), (c)(2), and 
(c)(3);
    (c) Take a marine mammal specified in Sec.  218.102(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 a Letter of Authorization issued 
under Sec. Sec.  216.106 and 218.107 of this chapter.


Sec.  218.104  Mitigation.

    (a) When conducting training and utilizing the sound sources or

[[Page 53867]]

explosives identified in Sec.  218.100(c), the mitigation measures 
contained in a Letter of Authorization issued under Sec. Sec.  216.106 
and 218.107 of this chapter must be implemented. These mitigation 
measures include, but are not limited to:
    (1) Personnel Training:
    (i) All commanding officers (COs), executive officers (XOs), 
lookouts, Officers of the Deck (OODs), junior OODs (JOODs), maritime 
patrol aircraft aircrews, and Anti-submarine Warfare (ASW)/Mine Warfare 
(MIW) helicopter crews shall complete the NMFS-approved Marine Species 
Awareness Training (MSAT) by viewing the U.S. Navy MSAT digital 
versatile disk (DVD). All bridge lookouts shall complete both parts one 
and two of the MSAT; part two is optional for other personnel.
    (ii) Navy lookouts shall undertake extensive training in order to 
qualify as a watchstander in accordance with the Lookout Training 
Handbook (Naval Education and Training Command [NAVEDTRA] 12968-D).
    (iii) Lookout training shall include on-the-job instruction under 
the supervision of a qualified, experienced lookout. Following 
successful completion of this supervised training period, lookouts 
shall complete the Personal Qualification Standard Program, certifying 
that they have demonstrated the necessary skills (such as detection and 
reporting of partially submerged objects). Personnel being trained as 
lookouts can be counted among required lookouts as long as supervisors 
monitor their progress and performance.
    (iv) Lookouts shall be trained in the most effective means to 
ensure quick and effective communication within the command structure 
in order to facilitate implementation of protective measures if marine 
species are spotted.
    (v) All lookouts onboard platforms involved in ASW training events 
will review the NMFS-approved Marine Species Awareness Training 
material prior to use of mid-frequency active sonar.
    (vi) All COs, XOs, and officers standing watch on the bridge will 
have reviewed the Marine Species Awareness Training material prior to a 
training event employing the use of MFAS/HFAS.
    (2) General Operating Procedures (for all training types):
    (i) Prior to major exercises, a Letter of Instruction, Mitigation 
Measures Message or Environmental Annex to the Operational Order shall 
be issued to further disseminate the personnel training requirement and 
general marine species protective measures.
    (ii) COs shall make use of marine species detection cues and 
information to limit interaction with marine mammals to the maximum 
extent possible consistent with safety of the ship.
    (iii) While underway, surface vessels shall have at least two 
lookouts with binoculars; surfaced submarines shall have at least one 
lookout with binoculars. Lookouts already posted for safety of 
navigation and man-overboard precautions may be used to fill this 
requirement. As part of their regular duties, lookouts will watch for 
and report to the OOD the presence of marine mammals.
    (iv) On surface vessels equipped with a multi-function active 
sensor, pedestal mounted ``Big Eye'' (20x110) binoculars shall be 
properly installed and in good working order to assist in the detection 
of marine mammals in the vicinity of the vessel.
    (v) Personnel on lookout shall employ visual search procedures 
employing a scanning methodology in accordance with the Lookout 
Training Handbook (NAVEDTRA 12968-D).
    (vi) After sunset and prior to sunrise, lookouts shall employ Night 
Lookouts Techniques in accordance with the Lookout Training Handbook 
(NAVEDTRA 12968-D).
    (vii) While in transit, naval vessels shall be alert at all times, 
use extreme caution, and proceed at a ``safe speed'', which means the 
speed at which the CO can maintain crew safety and effectiveness of 
current operational directives, so that the vessel can take action to 
avoid a collision with any marine mammal.
    (viii) When marine mammals have been sighted in the area, Navy 
vessels shall increase vigilance and take all reasonable actions to 
avoid collisions and close interaction of naval assets and marine 
mammals. Such action may include changing speed and/or direction and 
are dictated by environmental and other conditions (e.g., safety, 
weather).
    (ix) Navy aircraft participating in exercises at-sea shall conduct 
and maintain surveillance for marine mammals as long as it does not 
violate safety constraints or interfere with the accomplishment of 
primary operational duties.
    (x) All marine mammal detections shall be immediately reported to 
assigned Aircraft Control Unit for further dissemination to ships in 
the vicinity of the marine species as appropriate when it is reasonable 
to conclude that the course of the ship will likely result in a closing 
of the distance to the detected marine mammal.
    (3) Operating Procedures (for Anti-submarine Warfare Operations):
    (i) On the bridge of surface ships, there shall always be at least 
three people on watch whose duties include observing the water surface 
around the vessel.
    (ii) All surface ships participating in ASW training events shall 
have, in addition to the three personnel on watch noted in paragraph 
(a)(3)(i) of this section, at least two additional personnel on watch 
as lookouts at all times during the exercise.
    (iii) Personnel on lookout and officers on watch on the bridge will 
have at least one set of binoculars available for each person to aid in 
the detection of marine mammals.
    (iv) Personnel on lookout shall be responsible for reporting all 
objects or anomalies sighted in the water (regardless of the distance 
from the vessel) to the Officer of the Deck, since any object or 
disturbance (e.g., trash, periscope, surface disturbance, 
discoloration) in the water may be indicative of a threat to the vessel 
and its crew or indicative of a marine mammal that may need to be 
avoided.
    (v) All personnel engaged in passive acoustic sonar operation 
(including aircraft, surface ships, or submarines) shall monitor for 
marine mammal vocalizations and report the detection of any marine 
mammal to the appropriate watch station for dissemination and 
appropriate action.
    (vi) During mid-frequency active sonar operations, personnel shall 
utilize all available sensor and optical systems (such as night vision 
goggles) to aid in the detection of marine mammals.
    (vii) Aircraft with deployed sonobuoys shall use only the passive 
capability of sonobuoys when marine mammals are detected within 200 yds 
(183 m) of the sonobuoy.
    (viii) Helicopters shall observe/survey the vicinity of an ASW 
exercise for 10 minutes before the first deployment of active (dipping) 
sonar in the water.
    (ix) Helicopters shall not dip their sonar within 200 yards of a 
marine mammal and shall cease pinging if a marine mammal closes within 
200 yards after pinging has begun.
    (x) Safety Zones--When marine mammals are detected by any means 
(aircraft, shipboard lookout, or acoustically) within or closing to 
inside 1,000 yds (914 m) of the sonar dome (the bow), the ship or 
submarine shall limit active transmission levels to at least 6 decibels 
(dB) below normal operating levels for that source (i.e., limit to at 
most 229 dB for AN/SQS-53C and 219 for AN/SQS-56C, etc.).

[[Page 53868]]

    (A) Ships and submarines shall continue to limit maximum 
transmission levels by this 6-dB factor until the animal has been seen 
to leave the 1000-yd exclusion zone, has not been detected for 30 
minutes, or the vessel has transited more than 2,000 yds (1829 m) 
beyond the location of the last detection.
    (B) Should a marine mammal be detected within or closing to inside 
500 yds (457 m) of the sonar dome, active sonar transmissions shall be 
limited to at least 10 dB below the equipment's normal operating level 
(i.e., limit to at most 225 dB for AN/SQS-53C and 215 for AN/SQS-56C, 
etc.). Ships and submarines shall continue to limit maximum ping levels 
by this 10-dB factor until the animal has been seen to leave the 500-yd 
exclusion zone (at which point the 6-dB powerdown applies until the 
animal leaves the 1000-yd exclusion zone), has not been detected for 30 
minutes, or the vessel has transited more than 2,000 yds (1829 m) 
beyond the location of the last detection.
    (C) Should the marine mammal be detected within or closing to 
inside 200 yds (183 m) of the sonar dome, active sonar transmissions 
shall cease. Sonar shall not resume until the animal has been seen to 
leave the 200-yd exclusion zone (at which point the 10-dB or 6-dB 
powerdowns apply until the animal leaves the 500-yd or 1000-yd 
exclusion zone, respectively), has not been detected for 30 minutes, or 
the vessel has transited more than 2,000 yds (1829 m) beyond the 
location of the last detection.
    (D) Special conditions applicable for dolphins and porpoises only: 
If, after conducting an initial maneuver to avoid close quarters with 
dolphins or porpoises, the OOD 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.
    (xi) Prior to start up or restart of active sonar, operators will 
check that the Safety Zone radius around the sound source is clear of 
marine mammals.
    (xii) Active sonar levels (generally)--Navy shall operate active 
sonar at the lowest practicable level, not to exceed 235 dB, except as 
required to meet tactical training objectives.
    (xiii) Submarine sonar operators will review detection indicators 
of close-aboard marine mammals prior to the commencement of ASW 
training events involving MFAS.
    (xiv) If the need for power-down should arise (as detailed in Sec.  
218.114(a)(3)(x)) when the Navy was operating a hull-mounted or sub-
mounted source above 235 db (infrequent), the Navy shall follow the 
requirements as though they were operating at 235 dB--the normal 
operating level (i.e., the first power-down will be to 229 dB, 
regardless of at what level above 235 dB active sonar was being 
operated).
    (4) Operating Procedures for Underwater Detonations (up to 10-lb 
charges):
    (i) Exclusion Zones--All demolitions and ship mine countermeasures 
training exercises involving the use of explosive charges must include 
exclusion zones for marine mammals to prevent physical and/or acoustic 
effects to those species. These exclusion zones shall extend in a 700-
yard arc radius around the detonation site. Should a marine mammal be 
present within the the surveillance area, the explosive event shall not 
be started until the animal leaves the area.
    (ii) Pre-Exercise Surveys--For Demolition and Ship Mine 
Countermeasures Operations, pre-exercise surveys shall be conducted 
within 30 minutes prior to the commencement of the scheduled explosive 
event. The survey may be conducted from the surface, by divers, and/or 
from the air, and personnel shall be alert to the presence of any 
marine mammal. Should such an animal be present within the survey area, 
the explosive event shall not be started until the animal voluntarily 
leaves the area. The Navy will ensure the area is clear of marine 
mammals for a full 30 minutes prior to initiating the explosive event. 
Personnel will record any marine mammal observations during the 
exercise as well as measures taken if species are detected within the 
exclusion zone.
    (iii) Post-Exercise Surveys--Surveys within the same exclusion zone 
radius shall also be conducted within 30 minutes after the completion 
of the explosive event.
    (iv) Reporting--If there is evidence that a marine mammal may have 
been stranded, injured or killed by the action, Navy training 
activities shall be immediately suspended and the situation immediately 
reported by the participating unit to the Officer in Charge of the 
Exercise (OCE), who will follow Navy procedures for reporting the 
incident to Commander, Pacific Fleet, Commander, Navy Region Northwest, 
Environmental Director, and the chain-of-command. The situation shall 
also be reported to NMFS (see Stranding Plan for details).
    (5) Sinking Exercise:
    (i) All weapons firing shall be conducted during the period 1 hour 
after official sunrise to 30 minutes before official sunset.
    (ii) An exclusion zone with a radius of 1.0 nm (1.9 km) will be 
established around each target. An additional buffer of 0.5 nm (0.9 km) 
will be added to account for errors, target drift, and animal 
movements. Additionally, a safety zone, which will extend beyond the 
buffer zone by an additional 0.5 nm (0.9 km), would be surveyed. 
Together, the zones extend out 2 nm (3.7 km) from the target.
    (iii) A series of surveillance over-flights shall be conducted 
within the exclusion and the safety zones, prior to and during the 
exercise, when feasible. Survey protocol shall be as follows:
    (A) Overflights within the exclusion zone shall be conducted in a 
manner that optimizes the surface area of the water observed. This may 
be accomplished through the use of the Navy's Search and Rescue 
Tactical Aid, which provides the best search altitude, ground speed, 
and track spacing for the discovery of small, possibly dark objects in 
the water based on the environmental conditions of the day. These 
environmental conditions include the angle of sun inclination, amount 
of daylight, cloud cover, visibility, and sea state.
    (B) All visual surveillance activities shall be conducted by Navy 
personnel trained in visual surveillance. At least one member of the 
mitigation team will have completed the Navy's marine mammal training 
program for lookouts.
    (C) In addition to the overflights, the exclusion zone shall be 
monitored by passive acoustic means, when assets are available. This 
passive acoustic monitoring would be maintained throughout the 
exercise. Additionally, passive sonar onboard submarines may be 
utilized to detect any vocalizing marine mammals in the area. The OCE 
will be informed of any aural detection of marine mammals and will 
include this information in the determination of when it is safe to 
commence the exercise.
    (D) On each day of the exercise, aerial surveillance of the 
exclusion and safety zones shall commence 2 hours prior to the first 
firing.
    (E) The results of all visual, aerial, and acoustic searches shall 
be reported immediately to the OCE. No weapons launches or firing may 
commence until the OCE declares the safety and exclusion zones free of 
marine mammals.
    (F) If a marine mammal is observed within the exclusion zone, 
firing will be delayed until the animal is re-sighted

[[Page 53869]]

outside the exclusion zone, or 30 minutes have elapsed. After 30 
minutes, if the animal has not been re-sighted it can be assumed to 
have left the exclusion zone. The OCE will determine if the marine 
mammal is in danger of being adversely affected by commencement of the 
exercise.
    (G) During breaks in the exercise of 30 minutes or more, the 
exclusion zone shall again be surveyed for any marine mammal. If marine 
mammals are sighted within the exclusion zone or buffer zone, the OCE 
shall be notified, and the procedure described above shall be followed.
    (H) Upon sinking of the vessel, a final surveillance of the 
exclusion zone shall be monitored for 2 hours, or until sunset, to 
verify that no marine mammals were harmed.
    (iv) Aerial surveillance shall be conducted using helicopters or 
other aircraft based on necessity and availability. The Navy has 
several types of aircraft capable of performing this task; however, not 
all types are available for every exercise. For each exercise, the 
available asset best suited for identifying objects on and near the 
surface of the ocean shall be used. These aircraft shall be capable of 
flying at the slow safe speeds necessary to enable viewing of marine 
vertebrates with unobstructed, or minimally obstructed, downward and 
outward visibility. The exclusion and safety zone surveys may be 
cancelled in the event that a mechanical problem, emergency search and 
rescue, or other similar and unexpected event preempts the use of one 
of the aircraft onsite for the exercise.
    (v) Every attempt shall be made to conduct the exercise in sea 
states that are ideal for marine mammal sighting, Beaufort Sea State 3 
or less. In the event of a 4 or above, survey efforts shall be 
increased within the zones. This shall be accomplished through the use 
of an additional aircraft, if available, and conducting tight search 
patterns.
    (vi) The exercise shall not be conducted unless the exclusion zone 
and the buffer zone could be adequately monitored visually. Should low 
cloud cover or surface visibility prevent adequate visual monitoring as 
described previously, the exercise would be delayed until conditions 
improved, and all of the above monitoring criteria could be met.
    (vii) In the event that any marine mammals are observed to be 
harmed in the area, a detailed description of the animal shall be 
taken, the location noted, and if possible, photos taken of the marine 
mammal. This information shall be provided to NMFS via the Navy's 
regional environmental coordinator for purposes of identification (see 
the draft Stranding Plan for detail).
    (viii) An after action report detailing the exercise's time line, 
the time the surveys commenced and terminated, amount, and types of all 
ordnance expended, and the results of survey efforts for each event 
shall be submitted to NMFS.
    (6) Surface-to-Surface Gunnery (up to 5-inch Explosive Rounds).
    (i) For exercises using targets towed by a vessel, target-towing 
vessels shall maintain a trained lookout for marine mammals when 
feasible. If a marine mammal is sighted in the vicinity, the tow vessel 
will immediately notify the firing vessel, which will suspend the 
exercise until the area is clear.
    (ii) A 600 yard (585 m) radius buffer zone will be established 
around the intended target.
    (iii) From the intended firing position, trained lookouts will 
survey the buffer zone for marine mammals prior to commencement and 
during the exercise as long as practicable. Due to the distance between 
the firing position and the buffer zone, lookouts are only expected to 
visually detect breaching whales, whale blows, and large pods of 
dolphins and porpoises.
    (iv) The exercise will be conducted only when the buffer zone is 
visible and marine mammals are not detected within it.
    (7) Surface-to-Surface Gunnery (non-explosive rounds)
    (i) A 200-yd (183 m) radius buffer zone shall be established around 
the intended target.
    (ii) From the intended firing position, trained lookouts shall 
survey the buffer zone for marine mammals prior to commencement and 
during the exercise as long as practicable.
    (iii) If available, target towing vessels shall maintain a lookout 
(unmanned towing vessels will not have a lookout available). If a 
marine mammal is sighted in the vicinity of the exercise, the tow 
vessel shall immediately notify the firing vessel in order to secure 
gunnery firing until the area is clear.
    (iv) The exercise shall be conducted only when the buffer zone is 
visible and marine mammals are not detected within the target area and 
the buffer zone.
    (8) Surface-to-Air Gunnery (Explosive and Non-explosive Rounds).
    (i) Vessels will orient the geometry of gunnery exercises in order 
to prevent debris from falling in the area of sighted marine mammals.
    (ii) Vessels will expedite the attempt to recover of any parachute 
deploying aerial targets to reduce the potential for entanglement of 
marine mammals.
    (iii) Target towing aircraft shall maintain a lookout if feasible. 
If a marine mammal is sighted in the vicinity of the exercise, the tow 
aircraft will immediately notify the firing vessel in order to secure 
gunnery firing until the area is clear.
    (9) Air-to-Surface Gunnery (Explosive and Non-explosive Rounds).
    (i) A 200 yard (183 m) radius buffer zone will be established 
around the intended target.
    (ii) If surface vessels are involved, lookout(s) will visually 
survey the buffer zone for marine mammals to and during the exercise.
    (iii) Aerial surveillance of the buffer zone for marine mammals 
will be conducted prior to commencement of the exercise. Aerial 
surveillance altitude of 500 feet to 1,500 feet (152-456 m) is optimum. 
Aircraft crew/pilot will maintain visual watch during exercises. 
Release of ordnance through cloud cover is prohibited; aircraft must be 
able to actually see ordnance impact areas.
    (iv) The exercise will be conducted only if marine mammals are not 
visible within the buffer zone.
    (10) Small Arms Training (Grenades, Explosive and Non-explosive 
Rounds)--Lookouts will visually survey for marine mammals. Weapons will 
not be fired in the direction of known or observed marine mammals.
    (11) Air-to-Surface At-sea Bombing Exercises (explosive bombs and 
rockets):
    (i) If surface vessels are involved, trained lookouts shall survey 
for marine mammals. Ordnance shall not be targeted to impact within 
1,000 yds (914 m) of known or observed marine mammals.
    (ii) A 1,000 yd (914 m) radius buffer zone shall be established 
around the intended target.
    (iii) Aircraft shall visually survey the target and buffer zone for 
marine mammals prior to and during the exercise. The survey of the 
impact area shall be made by flying at 1,500 ft (152 m) or lower, if 
safe to do so, and at the slowest safe speed. When safety or other 
considerations require the release of weapons without the releasing 
pilot having visual sight of the target area, a second aircraft, the 
``wingman,'' will clear the target area and perform the clearance and 
observation functions required before the dropping plane may release 
its weapons. Both planes must have direct communication to assure 
immediate notification to the dropping plane that the target area may 
have been fouled by encroaching animals or people. The clearing 
aircraft will assure

[[Page 53870]]

it has visual site of the target area at a maximum height of 1500 ft. 
The clearing plane will remain within visual sight of the target until 
required to clear the area for safety reasons. Survey aircraft shall 
employ most effective search tactics and capabilities.
    (iv) The exercise will be conducted only if marine mammals are not 
visible within the buffer zone.
    (12) Air-to-Surface At-Sea Bombing Exercises (Non-explosive Bombs 
and Rockets).
    (i) If surface vessels are involved, trained lookouts will survey 
for marine mammals. Ordnance shall not be targeted to impact within 
1,000 yards (914 m) of known or observed marine mammals.
    (ii) A 1,000 yard (914 m) radius buffer zone will be established 
around the intended target.
    (iii) Aircraft will visually survey the target and buffer zone for 
marine mammals prior to and during the exercise. The survey of the 
impact area will be made by flying at 1,500 feet (152 m) or lower, if 
safe to do so, and at the slowest safe speed. When safety or other 
considerations require the release of weapons without the releasing 
pilot having visual sight of the target area, a second aircraft, the 
``wingman,'' will clear the target area and perform the clearance and 
observation functions required before the dropping plane may release 
its weapons. Both planes must have direct communication to assure 
immediate notification to the dropping plane that the target area may 
have been fouled by encroaching animals or people. The clearing 
aircraft will assure it has visual site of the target area at a maximum 
height of 1500 ft. The clearing plane will remain within visual sight 
of the target until required to clear the area for safety reasons. 
Survey aircraft shall employ most effective search tactics and 
capabilities.
    (iv) The exercise will be conducted only if marine mammals are not 
visible within the buffer zone.
    (13) Air-to-Surface Missile Exercises (explosive and non-
explosive):
    (i) Aircraft will visually survey the target area for marine 
mammals. Visual inspection of the target area will be made by flying at 
1,500 (457 m) feet or lower, if safe to do so, and at slowest safe 
speed. Firing or range clearance aircraft must be able to actually see 
ordnance impact areas.
    (ii) Explosive ordnance shall not be targeted to impact within 
1,800 yds (1646 m) of sighted marine mammals.
    (14) Aircraft Training Activities Involving Non-Explosive Devices: 
Non-explosive devices such as some sonobuoys, inert bombs, and Mining 
Training Activities involve aerial drops of devices that have the 
potential to hit marine mammals if they are in the immediate vicinity 
of a floating target. The exclusion zone (200 yd), therefore, shall be 
clear of marine mammals and around the target location. Pre- and post-
surveillance and reporting requirements outlined for underwater 
detonations shall be implemented during Mining Training Activities.
    (15) Extended Echo Ranging/Improved Extended Echo Ranging (EER/
IEER):
    (i) Crews shall conduct visual reconnaissance of the drop area 
prior to laying their intended sonobuoy pattern. This search shall be 
conducted at an altitude below 457 m (500 yd) at a slow speed, if 
operationally feasible and weather conditions permit. In dual aircraft 
operations, crews are allowed to conduct coordinated area clearances.
    (ii) Crews shall conduct a minimum of 30 minutes of visual and 
aural monitoring of the search area prior to commanding the first post 
detonation. This 30-minute observation period may include pattern 
deployment time.
    (iii) For any part of the briefed pattern where a post (source/
receiver sonobuoy pair) will be deployed within 914 m (1,000 yd) of 
observed marine mammal activity, the Navy shall deploy the receiver 
ONLY and monitor while conducting a visual search. When marine mammals 
are no longer detected within 914 m (1,000 yd) of the intended post 
position, the Navy shall co-locate the explosive source sonobuoy (AN/
SSQ-110A) (source) with the receiver.
    (iv) When operationally feasible, Navy crews shall conduct 
continuous visual and aural monitoring of marine mammal activity. This 
is to include monitoring of own-aircraft sensors from first sensor 
placement to checking off station and out of RF range of these sensors.
    (v) Aural Detection--If the presence of marine mammals is detected 
aurally, then that shall cue the Navy aircrew to increase the diligence 
of their visual surveillance. Subsequently, if no marine mammals are 
visually detected, then the crew may continue multi-static active 
search.
    (vi) Visual Detection--If marine mammals are visually detected 
within 914 m (1,000 yd) of the explosive source sonobuoy (AN/SSQ-110A) 
intended for use, then that payload shall not be detonated. Aircrews 
may utilize this post once the marine mammals have not been re-sighted 
for 30 minutes, or are observed to have moved outside the 914 m (1,000 
yd) safety buffer. Aircrews may shift their multi-static active search 
to another post, where marine mammals are outside the 914 m (1,000 yd) 
safety buffer.
    (vii) Aircrews shall make every attempt to manually detonate the 
unexploded charges at each post in the pattern prior to departing the 
operations area by using the ``Payload 1 Release'' command followed by 
the ``Payload 2 Release'' command. Aircrews shall refrain from using 
the ``Scuttle'' command when two payloads remain at a given post. 
Aircrews will ensure that a 914 m (1,000 yd) safety buffer, visually 
clear of marine mammals, is maintained around each post as is done 
during active search operations.
    (viii) Aircrews shall only leave posts with unexploded charges in 
the event of a sonobuoy malfunction, an aircraft system malfunction, or 
when an aircraft must immediately depart the area due to issues such as 
fuel constraints, inclement weather, and in-flight emergencies. In 
these cases, the sonobuoy will self-scuttle using the secondary or 
tertiary method.
    (ix) The Navy shall ensure all payloads are accounted for. 
Explosive source sonobuoys (AN/SSQ-110A) that can not be scuttled shall 
be reported as unexploded ordnance via voice communications while 
airborne, then upon landing via naval message.
    (x) Mammal monitoring shall continue until out of own-aircraft 
sensor range.
    (16) The Navy shall abide by the letter of the ``Stranding Response 
Plan for Major Navy Training Exercises in the MIRC'' (available at: 
http://www.nmfs.noaa.gov/pr/permits/incidental.htm), which is 
incorporated herein by reference, to include the following measures:
    (i) Shutdown Procedures--When an Uncommon Stranding Event (USE--
defined in Sec.  216.271) occurs during a Major Training Exercise (MTE) 
(as defined in the Stranding Plan, meaning including Multi-strike group 
exercises, Joint Expeditionary exercises, and Marine Air Ground Task 
Force exercises in the MIRC), the Navy shall implement the procedures 
described below.
    (A) The Navy shall implement a Shutdown (as defined in the 
Stranding Response Plan for MIRC) when advised by a NMFS Office of 
Protected Resources Headquarters Senior Official designated in the MIRC 
Stranding Communication Protocol that a USE (as defined in the 
Stranding Response Plan for MIRC) involving live animals has been 
identified and that at least one live animal is located in the water. 
NMFS and Navy shall communicate, as needed, regarding the 
identification of the USE and the potential need to implement shutdown 
procedures.

[[Page 53871]]

    (B) 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).
    (C) If the Navy finds an injured or dead marine mammal 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 behaviors (if alive), and 
photo or video of the animals (if available). Based on the information 
provided, NMFS shall determine if, and advise the Navy whether a 
modified shutdown is appropriate on a case-by-case basis.
    (D) In the event, following a USE, that: (a) Qualified individuals 
are attempting to herd animals back out to the open ocean and animals 
are not willing to leave, or (b) 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 MFAS/HFAS 
activities or explosive detonations, though farther than 14 nm from the 
distressed animal(s), is likely decreasing the likelihood that the 
animals return to the open water. If so, NMFS and the Navy shall 
further coordinate to determine what measures are necessary to further 
minimize that likelihood and implement those measures as appropriate.
    (ii) Within 72 hours of NMFS notifying the Navy of the presence of 
a USE, the Navy shall provide available information to NMFS (per the 
MIRC Communication Protocol) regarding the location, number and types 
of acoustic/explosive sources, direction and speed of units using MFAS/
HFAS, and marine mammal sightings information associated with training 
activities occurring within 80 nm (148 km) and 72 hours prior to the 
USE event. Information not initially available regarding the 80 nm (148 
km), 72 hours, period prior to the event shall be provided as soon as 
it becomes available. The Navy shall provide NMFS investigative teams 
with additional relevant unclassified information as requested, if 
available.
    (iii) Memorandum of Agreement (MOA)--The Navy and NMFS shall 
develop a MOA, or other mechanism, that will establish a framework 
whereby the Navy can (and provide the Navy examples of how they can 
best) assist NMFS with stranding investigations in certain 
circumstances.
    (b) [Reserved]


Sec.  218.105  Requirements for monitoring and reporting.

    (a) General notification of injured or dead marine mammals. Navy 
personnel shall ensure that NMFS is notified immediately ((see 
Communication Plan) or as soon as clearance procedures allow) if an 
injured, stranded, or dead marine mammal is found during or shortly 
after, and in the vicinity of, any Navy training exercise utilizing 
MFAS, HFAS, or underwater explosive detonations. The Navy will provide 
NMFS with species or description of the animal (s), the condition of 
the animal(s) (including carcass condition if the animal is dead), 
location, time of first discovery, observed behaviors (if alive), and 
photo or video of the animals (if available). In the event that an 
injured, stranded, or dead marine mammal is found by the Navy that is 
not in the vicinity of, or during or shortly after, MFAS, HFAS, or 
underwater explosive detonations, the Navy will report the same 
information as listed above as soon as operationally feasible and 
clearance procedures allow.
    (b) General notification of ship strike. In the event of a ship 
strike by any Navy vessel, at any time or place, the Navy shall do the 
following:
    (1) Immediately report to NMFS the species identification (if 
known), location (lat/long) of the animal (or the strike if the animal 
has disappeared), and whether the animal is alive or dead, or whether 
its status is unknown.
    (2) Report to NMFS as soon as operationally feasible the size and 
length of animal, an estimate of the injury status (ex., dead, injured 
but alive, injured and moving, unknown, etc.), vessel class/type and 
operational status.
    (3) Report to NMFS the vessel length, speed, and heading as soon as 
feasible.
    (4) Provide NMFS a photo or video of the animal(s), if equipment is 
available
    (c) The Navy must conduct all monitoring and/or research required 
under the Letter of Authorization including abiding by the MIRC 
Monitoring Plan. (http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications)
    (d) Report on monitoring required in paragraph (c) of this section. 
The Navy shall submit a report annually on November 15 describing the 
implementation and results (through June 1 of the same year) of the 
monitoring required in paragraph (c) of this section. Navy will 
standardize data collection methods across ranges to allow for 
comparison in different geographic locations.
    (e) Sonar exercise notification. The Navy shall submit to the NMFS 
Office of Protected Resources (specific contact information to be 
provided in LOA) either an electronic (preferably) or verbal report 
within fifteen calendar days after the completion of any MTER 
indicating:
    (1) Location of the exercise;
    (2) Beginning and end dates of the exercise; and
    (3) Type of exercise.
    (f) Annual MIRC Report. The Navy will submit an Annual Exercise 
MIRC Report on November 15 of every year (covering data gathered 
through September 15). This report shall contain the subsections and 
information indicated below.
    (1) MFAS/HFAS Major Training Exercises--This section shall contain 
the following information for the following Coordinated and Strike 
Group exercises, which for simplicity will be referred to as major 
training exercises for reporting (MTERs): Joint Multi-strike Group 
Exercises; Joint Expeditionary Exercises; and Marine Air Ground Task 
Force MIRC:
    (i) Exercise Information (for each MTER):
    (A) Exercise designator;
    (B) Date that exercise began and ended;
    (C) Location;
    (D) Number and types of active sources used in the exercise;
    (E) Number and types of passive acoustic sources used in exercise;
    (F) Number and types of vessels, aircraft, etc., participating in 
exercise;
    (G) Total hours of observation by watchstanders;
    (H) Total hours of all active sonar source operation;
    (I) Total hours of each active sonar source (along with explanation 
of how hours are calculated for sources typically quantified in 
alternate way (buoys, torpedoes, etc.)); and
    (J) Wave height (high, low, and average during exercise).
    (ii) Individual marine mammal sighting info (for each sighting in 
each MTER):
    (A) Location of sighting;
    (B) Species (if not possible--indication of whale/dolphin/
pinniped);
    (C) Number of individuals;
    (D) Calves observed (y/n);
    (E) Initial Detection Sensor;
    (F) Indication of specific type of platform observation made from 
(including, for example, what type of surface vessel, i.e., FFG, DDG, 
or CG);

[[Page 53872]]

    (G) Length of time observers maintained visual contact with marine 
mammal(s);
    (H) Wave height (in feet);
    (I) Visibility;
    (J) Sonar source in use (y/n);
    (K) Indication of whether animal is <200yd, 200-500yd, 500-1000yd, 
1000-2000yd, or >2000yd from sonar source in Sec.  218.104(a)(3)(x);
    (L) Mitigation Implementation--Whether operation of sonar sensor 
was delayed, or sonar was powered or shut down, and how long the delay 
was;
    (M) If source in use in Sec.  218.104(a)(3)(x) is hullmounted, true 
bearing of animal from ship, true direction of ship's travel, and 
estimation of animal's motion relative to ship (opening, closing, 
parallel); and
    (N) Observed behavior--Watchstanders shall report, in plain 
language and without trying to categorize in any way, the observed 
behavior of the animals (such as animal closing to bow ride, 
paralleling course/speed, floating on surface and not swimming, etc.).
    (iii) An evaluation (based on data gathered during all of the 
MTERs) of the effectiveness of mitigation measures designed to avoid 
exposing marine mammals to MFAS. This evaluation shall identify the 
specific observations that support any conclusions the Navy reaches 
about the effectiveness of the mitigation.
    (2) ASW Summary--This section shall include the following 
information as summarized from non-major training exercises (unit-level 
exercises, such as TRACKEXs):
    (i) Total Hours--Total annual hours of each type of sonar source 
(along with explanation of how hours are calculated for sources 
typically quantified in alternate way (buoys, torpedoes, etc.))
    (ii) Cumulative Impacts--To the extent practicable, the Navy, in 
coordination with NMFS, shall develop and implement a method of 
annually reporting non-major training (i.e., ULT) utilizing hull-
mounted sonar. The report shall present an annual (and seasonal, where 
practicable) depiction of non-major training exercises geographically 
across MIRC. The Navy shall include (in the MIRC annual report) a brief 
annual progress update on the status of the development of an effective 
and unclassified method to report this information until an agreed-upon 
(with NMFS) method has been developed and implemented.
    (3) Sinking Exercises (SINKEXs)--This section shall include the 
following information for each SINKEX completed that year:
    (i) Exercise Info:
    (A) Location;
    (B) Date and time exercise began and ended;
    (C) Total hours of observation by watchstanders before, during, and 
after exercise;
    (D) Total number and types of rounds expended/explosives detonated;
    (E) Number and types of passive acoustic sources used in exercise;
    (F) Total hours of passive acoustic search time;
    (G) Number and types of vessels, aircraft, etc., participating in 
exercise;
    (H) Wave height in feet (high, low and average during exercise); 
and
    (I) Narrative description of sensors and platforms utilized for 
marine mammal detection and timeline illustrating how marine mammal 
detection was conducted.
    (ii) Individual marine mammal observation during SINKEX (by Navy 
lookouts) information:
    (A) Location of sighting;
    (B) Species (if not possible--indication of whale/dolphin/
pinniped);
    (C) Number of individuals;
    (D) Calves observed (y/n);
    (E) Initial detection sensor;
    (F) Length of time observers maintained visual contact with marine 
mammal;
    (G) Wave height;
    (H) Visibility;
    (I) Whether sighting was before, during, or after detonations/
exercise, and how many minutes before or after;
    (J) Distance of marine mammal from actual detonations (or target 
spot if not yet detonated)--use four categories to define distance:
    (1) The modeled injury threshold radius for the largest explosive 
used in that exercise type in that OPAREA (TBD m for SINKEX in MIRC);
    (2) The required exclusion zone (1 nm for SINKEX in MIRC);
    (3) The required observation distance (if different than the 
exclusion zone (2 nm for SINKEX in MIRC); and
    (4) Greater than the required observed distance. For example, in 
this case, the observer shall indicate if < TBD m, from 426 m-1 nm, 
from 1 nm-2 nm, and > 2 nm.
    (K) Observed behavior--Watchstanders will 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.), including speed and 
direction.
    (L) Resulting mitigation implementation--Indicate whether explosive 
detonations were delayed, ceased, modified, or not modified due to 
marine mammal presence and for how long.
    (M) If observation occurs while explosives are detonating in the 
water, indicate munitions type in use at time of marine mammal 
detection.
    (4) Improved Extended Echo-Ranging System (IEER) Summary:
    (i) Total number of IEER events conducted in MIRC;
    (ii) Total expended/detonated rounds (buoys); and
    (iii) Total number of self-scuttled IEER rounds.
    (5) Explosives Summary--The Navy is in the process of improving the 
methods used to track explosive use to provide increased granularity. 
To the extent practicable, the Navy shall provide the information 
described below for all of their explosive exercises. Until the Navy is 
able to report in full the information below, they will provide an 
annual update on the Navy's explosive tracking methods, including 
improvements from the previous year.
    (i) Total annual number of each type of explosive exercise (of 
those identified as part of the ``specified activity'' in this final 
rule) conducted in MIRC; and
    (ii) Total annual expended/detonated rounds (missiles, bombs, etc.) 
for each explosive type.
    (g) MIRC 5-Yr Comprehensive Report. The Navy shall submit to NMFS a 
draft report that analyzes and summarizes all of the multi-year marine 
mammal information gathered during ASW and explosive exercises for 
which annual reports are required (Annual MIRC Exercise Reports and 
MIRC Monitoring Plan Reports). This report will be submitted at the end 
of the fourth year of the rule (November 2013), covering activities 
that have occurred through July 15, 2014.
    (h) Comprehensive National ASW Report. By June, 2014, the Navy 
shall submit a draft National Report that analyzes, compares, and 
summarizes the active sonar data gathered (through January 1, 2014) 
from the watchstanders and pursuant to the implementation of the 
Monitoring Plans for the Northwest Training Range Complex, the Southern 
California Range Complex, the Atlantic Fleet Active Sonar Training, the 
Hawaii Range Complex, the Marianas Islands Range Complex, and the Gulf 
of Alaska.


Sec.  218.106  Applications for Letters of Authorization.

    To incidentally take marine mammals pursuant to these regulations, 
the U.S. Citizen (as defined by Sec.  216.103 of this chapter) 
conducting the activity identified in Sec.  218.100(c) (i.e., the Navy) 
must apply for and obtain either an initial Letter of Authorization in

[[Page 53873]]

accordance with Sec.  218.107 or a renewal under Sec.  218.108.


Sec.  218.107  Letters of Authorization.

    (a) A Letter of Authorization, unless suspended or revoked, will be 
valid for a period of time not to exceed the period of validity of this 
subpart, but must be renewed annually subject to annual renewal 
conditions in Sec.  218.108.
    (b) Each Letter of Authorization shall 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 Letter of Authorization shall 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.  218.108  Renewal of Letters of Authorization and adaptive 
management.

    (a) A Letter of Authorization issued under Sec.  216.106 and Sec.  
218.177 of this chapter or the activity identified in Sec.  218.170(c) 
will be renewed annually upon:
    (1) Notification to NMFS that the activity described in the 
application submitted under Sec.  218.246 will be undertaken and that 
there will not be a substantial modification to the described work, 
mitigation or monitoring undertaken during the upcoming 12 months;
    (2) Receipt of the monitoring reports and notifications within the 
indicated timeframes required under Sec.  218.105(b) through (j); and
    (3) A determination by the NMFS that the mitigation, monitoring and 
reporting measures required under Sec.  218.104 and the Letter of 
Authorization issued under Sec. Sec.  216.106 and 218.107 of this 
chapter, were undertaken and will be undertaken during the upcoming 
annual period of validity of a renewed Letter of Authorization.
    (b) If a request for a renewal of a Letter of Authorization issued 
under Sec. Sec.  216.106 and 216.248 of this chapter indicates that a 
substantial modification, as determined by NMFS, to the described work, 
mitigation or monitoring undertaken during the upcoming season will 
occur, the NMFS will provide the public a period of 30 days for review 
and comment on the request. Review and comment on renewals of Letters 
of Authorization are restricted to:
    (1) New cited information and data indicating that the 
determinations made in this document are in need of reconsideration, 
and
    (2) Proposed changes to the mitigation and monitoring requirements 
contained in these regulations or in the current Letter of 
Authorization.
    (c) A notice of issuance or denial of a renewal of a Letter of 
Authorization will be published in the Federal Register.
    (d) Adaptive Management--NMFS may modify or augment the existing 
mitigation or monitoring 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 
mitigation and monitoring set forth in the preamble of these 
regulations. Below are some of the possible sources of new data that 
could contribute to the decision to modify the mitigation or monitoring 
measures:
    (1) Results from the Navy's monitoring from the previous year 
(either from the MIRC Study Area or other locations).
    (2) Findings of the Monitoring Workshop that the Navy will convene 
in 2011.
    (3) Compiled results of Navy funded research and development (R&D) 
studies (presented pursuant to the Integrated Comprehensive Monitoring 
Plan).
    (4) Results from specific stranding investigations (either from the 
MIRC Study Area or other locations, and involving coincident MFAS/HFAS 
or explosives training or not involving coincident use).
    (5) Results from the Long Term Prospective Study described in the 
preamble to these regulations.
    (6) Results from general marine mammal and sound research (funded 
by the Navy (described below) or otherwise).


Sec.  218.109  Modifications to Letters of Authorization.

    (a) Except as provided in paragraph (b) of this section, no 
substantive modification (including withdrawal or suspension) to the 
Letter of Authorization by NMFS, issued pursuant to Sec. Sec.  216.106 
and 218.107 of this chapter and subject to the provisions of this 
subpart, shall be made until after notification and an opportunity for 
public comment has been provided. For purposes of this paragraph, a 
renewal of a Letter of Authorization under Sec.  218.108, without 
modification (except for the period of validity), is not considered a 
substantive modification.
    (b) If the Assistant Administrator determines that an emergency 
exists that poses a significant risk to the well-being of the species 
or stocks of marine mammals specified in Sec.  218.100(b), a Letter of 
Authorization issued pursuant to Sec. Sec.  216.106 and 218.107 of this 
chapter may be substantively modified without prior notification and an 
opportunity for public comment. Notification will be published in the 
Federal Register within 30 days subsequent to the action.

[FR Doc. E9-24837 Filed 10-19-09; 8:45 am]
BILLING CODE 3510-22-P