[Federal Register Volume 75, Number 201 (Tuesday, October 19, 2010)]
[Proposed Rules]
[Pages 64508-64583]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-25230]



[[Page 64507]]

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Part III





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 
Conducted Within the Gulf of Alaska (GoA) Temporary Maritime Activities 
Area (TMAA); Proposed Rule

Federal Register / Vol. 75 , No. 201 / Tuesday, October 19, 2010 / 
Proposed Rules

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 218

[Docket No. 100817363-0365-02]
RIN 0648-BA14


Taking and Importing Marine Mammals; Military Training Activities 
Conducted Within the Gulf of Alaska (GoA) Temporary Maritime Activities 
Area (TMAA)

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 to take marine mammals incidental to training activities 
conducted in the Gulf of Alaska (GoA) Temporary Maritime Activities 
Area (TMAA) for the period December 2010 through December 2015. 
Pursuant to the Marine Mammal Protection Act (MMPA), NMFS proposes 
regulations to govern that take and requests information, suggestions, 
and comments on these proposed regulations. Specifically, we encourage 
the public to recommend effective, regionally specific methods for 
augmenting existing marine mammal density, distribution, and abundance 
information in the GoA TMAA and to prioritize the specific density and 
distribution data needs in the area (species, time of year, etc.). This 
information will ensure the design of the most effective Monitoring 
Plan with the resources available.

DATES: Comments and information must be received no later than November 
18, 2010.

ADDRESSES: You may submit comments, identified by 0648-BA14, 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, Brian D. Hopper, or 
Michelle Magliocca, Office of Protected Resources, NMFS, (301) 713-
2289.

SUPPLEMENTARY INFORMATION:

Availability

    A copy of the Navy's application, as well as the draft Monitoring 
Plan and the draft Stranding Response Plan for GoA TMAA, 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 GoA TMAA was published on December 11, 2009 
and may be viewed at http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. NMFS participates 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): 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 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 March 2009, NMFS received an application from the Navy 
requesting authorization to take individuals of 20 species of marine 
mammals (15 cetaceans and 5 pinnipeds) incidental to upcoming training 
activities to be conducted from December 2010 through December 2015 in 
the GoA TMAA, which is a 42,146 square nautical mile (nm \2\) (145,482 
km \2\) polygon roughly the shape of a 300 nm (555.6 km) by 150 nm 
(277.8 km) rectangle oriented northwest to southeast in the long 
direction. NMFS subsequently requested additional information, which 
was provided in November 2009 in the form of a revised application. 
These training activities are classified as military readiness 
activities under the provisions of the NDAA of 2004. These military 
readiness activities may incidentally take marine mammals within the 
TMAA 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 20 species of cetaceans and 
pinnipeds by Level B Harassment. Further, although it does not 
anticipate that it will occur, the Navy requests authorization to take, 
by injury or mortality, up to 15 individual beaked whales (of any of 
the following species: Baird's beaked whale, Cuvier's beaked whale, 
Stejneger's beaked whale) over the course of the 5-year regulations.

[[Page 64509]]

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 Title 10 of the United 
States Code directs the Chief of Naval Operations to train all military 
forces for combat. The Chief of Naval Operations meets that direction, 
in part, by conducting at-sea training exercises and ensuring naval 
forces have access to ranges, operating areas (OPAREAs) and airspace 
where they can develop and maintain skills for wartime missions and 
conduct research, development, testing, and evaluation (RDT&E) of naval 
systems.
    The specified training activities addressed in this proposed rule 
are a subset of the Proposed Action described in the GoA TMAA DEIS, 
which would support and maintain Department of Defense training and 
assessments of current capabilities. Training does 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 GoA TMAA to:
    <bullet> Increase the number of training activities from current 
levels (up to 14 days) as necessary to support Fleet exercise 
requirements (that could last up to 21 days between April and October);
    <bullet> Conduct training in the Primary Mission Areas (PMARs) 
including Anti-Air Warfare (AAW), Anti-Surface Warfare (ASUW), Anit-
Submarine Warfare (ASW), Naval Special Warfare (NSW), Strike Warfare 
(STW), and Electronic Combat (EC). Conduct of training may include that 
necessary for newer systems, instrumentation, and platforms, including 
the EA-18G Growler aircraft, Guided Missile Submarines (SSGN), P-8 
Poseidon Multimission Maritime Aircraft (MMA), Guided Missile Destroyer 
(DDG) 1000 (Zumwalt Class) destroyer, and several types of Unmanned 
Aerial Systems (UASs);
    <bullet> Accommodate training enhancement instrumentation, to 
include the use of a Portable Undersea Tracking Range (PUTR);
    <bullet> Conduct an additional Carrier Strike Group (CSG) exercise 
during the months of April through October, which could also last up to 
21 days (first CSG exercise being part of the baseline No Action 
Alternative); and
    <bullet> Conduct a Sinking Exercise (SINKEX) during each summertime 
exercise (maximum of two) in the TMAA.
    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> Helicopter Anti-submarine Warfare (ASW) tracking exercise 
(TRACKEX) (includes use of MFAS and HFAS dipping sonar and sonobuoys)
    <bullet> Surface ASW TRACKEX (includes use of hull-mounted MFAS)
    <bullet> Submarine ASW (includes use of hull-mounted MFAS and HFAS)
    <bullet> Fixed-wing Marine Patrol Aircraft (MPA) ASW TRACKEX 
(includes use of sonobuoys)
    <bullet> Extended Echo Ranging ASW (includes explosive sonobuoys)
    <bullet> Bombing Exercises (BOMBEX)
    <bullet> Sinking Exercises (SINKEX)
    <bullet> Gunnery Exercises (GUNEX)
Overview of the GoA TMAA
    Since the 1990s, the Navy has participated in a major joint 
training exercise that involves the Departments of the Navy, Army, Air 
Force, and Coast Guard participants reporting to a unified or joint 
commander who coordinates the activities planned to demonstrate and 
evaluate the ability of the services to engage in a conflict and carry 
out plans in response to a threat to national security. Previous 
exercises in the TMAA have occurred in the summer (April-October) 
timeframe due to the extreme cold weather and sea state conditions in 
the TMAA during the winter months. The areas making up the Alaska 
Training Areas (ATAs) (see figure 1-1 in the Navy's application) 
consist of 3 components: (1) TMAA; (2) U.S. Air Force over-land Special 
Use Airspace (SUA) and air routes over the GoA and State of Alaska; and 
(3) U.S. Army training lands.
    Within the northeastern GoA, the TMAA is comprised of the 42,146 
square nautical miles (nm\2\) (145,482 square kilometer (km\2\) of 
surface and subsurface area and 88,731 nm\2\ (305,267 km\2\)) of 
special use airspace (SUA) (not including the portion of Warning Area 
612 [W-612] that falls outside of the TMAA). The TMAA is roughly 
rectangular and oriented from northwest to southeast, approximately 300 
nautical miles (nm) (556 kilometer (km)) long by 150 nm (278 km) wide, 
situated south of Prince William Sound and east of Kodiak Island. With 
the exception of Cape Cleare on Montague Island located over 12 nm (22 
km) from the northern point of the TMAA, the nearest shoreline (Kenai 
Peninsula) is located approximately 24 nm (44 km) north of the TMAA's 
northern boundary. The approximate middle of the TMAA is located 140 nm 
(259 km) offshore.
    The abyssal plain in the GoA gradually shoals from a 16,400 feet 
(ft) (5,000 meter (m)) depth in the southwestern GoA to less than 9,843 
ft (3,000 m) in the northeastern expanses of the Gulf. Maximal depths 
exceed 22,965 ft (7,000 m) near the central Aleutian Trench along the 
continental slope south of the Aleutian Islands. Numerous seamounts, 
remnants of submarine volcanoes, are scattered across the central 
basin. Several of the seamounts rise to within a few hundred meters of 
the sea surface.
    Ocean circulation in the GoA is defined by the cyclonic motion of 
the Pacific subpolar gyre (also referred to as the Alaska Gyre), which 
is composed of the North Pacific Current, the Alaska Current, and the 
Alaskan Stream. Circulation patterns along the shelf divide the region 
into the inner shelf (or Alaska Coastal Current domain), the mid-shelf, 
and the outer shelf including the shelf break (DoN, 2006). The center 
of the gyre is located at approximately 52 to 53 [deg]N and 145 to 155 
[deg]W. Nearshore flow is dominated by the Alaskan Coastal Current and 
is less organized than the flow found along the shelf break and slope. 
The northwestern GoA also includes several prominent geological 
features that influence the regional oceanography. For example, Kayak 
Island extends 50 km across the continental shelf to the east of the 
Copper River. This island can deflect shelf waters farther offshore 
delivering high concentrations of suspended sediment to the outer shelf 
(DoN, 2006).
    During winter months, intense circulation over the GoA produces 
easterly coastal winds and downwelling, both of which result in a well-
mixed water column. During the summer, stratification develops due to 
decreased winds, increased freshwater discharge, and increased solar 
radiation. Under summer and fall conditions, the shelf waters are 
stratified with the upper water column temperatures at their maximum 
and salinities at their minimum. On longer time scales, there is 
evidence of interannual variation in the circulation patterns within 
the GoA. These variations result from the climatic variability of the 
El Ni[ntilde]o Southern Oscillation (ENSO) and the Pacific Decadal 
Oscillation (PDO) (DoN, 2006).
    Generally, two surface temperature regimes characterize the 
northern expanses of the GoA throughout the year. Relatively warm 
surface water occurs over the continental shelf, while colder water is 
found farther offshore

[[Page 64510]]

beyond the shelf break. Thermal stratification remains weak until late 
May or June, then strong stratification persists through the summer 
months. As winds intensify in the fall, stratification dissipates, due 
to stronger vertical mixing and increased downwelling, surface waters 
sink along the coast, and the thermocline deepens throughout the 
region. Along the continental shelf and within the coastal fjords, 
waters are often highly stratified by both salinity and temperature; an 
intense thermocline occurs at approximately 82 ft (25 m). Farther 
offshore in the Alaskan Stream, maximal stratification occurs between 
depths of 328 ft to 984 ft (100 to 300 m) and is associated primarily 
with a permanent halocline in the GoA (DoN, 2006).
Specified Activities
    As mentioned above, the Navy has requested MMPA authorization to 
take marine mammals incidental to training in the GoA TMAA 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 Air Combat Maneuvers 
(ACM), Visit Board Search and Seizure/Vessels of Interest (VBSS/VOI), 
Maritime Interdiction (MI), Chaff Exercises, Sea Surface Control (SSC), 
and Naval Special Warfare Insertion/Extraction exercises; however, 
these activities are primarily air or land 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 GoA TMAA, 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 training 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 sonar 
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 
only provides information about 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 frequency range classifications for active 
sonar: Low-frequency (LF), mid-frequency (MF), and high-frequency (HF).
    MFAS, as defined in the Navy's GoA TMAA 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 mid-range detection of adversary submarines before they 
are able to conduct an attack is essential to U.S. 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 ASW training is necessary for sailors 
on ships and in strike groups to gain proficiency using MFAS. Moreover, 
if a strike group does not demonstrate MFAS proficiency, it cannot be 
certified as combat ready.
    HFAS, as defined in the Navy's GoA TMAA 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, which are all short range 
applications. Training exercises in the GoA TMAA will include the use 
of HFAS.
    Low-frequency sources operate below 1 kHz. Sonar in this frequency 
range is designed to detect extremely quiet diesel-electric submarines 
at ranges far beyond the capabilities of MFA sonars. Currently, there 
are only two ships in use by the Navy equipped with low-frequency 
sonar; both are ocean surveillance vessels operated by Military Sealift 
Command. While Surveillance Towed Array Sensor System (SURTASS) low-
frequency active sonar was analyzed in a separate EIS/OEIS, use of low-
frequency active sonar is not part of the planned training activities 
considered for the GoA TMAA.

Acoustic Sources Used for ASW Exercises in the GoA TMAA

    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 sonars emit an omni-directional ping and then 
rapidly scan 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 and other sound sources employed 
during training exercises in the GoA TMAA are identified in Table 1.
BILLING CODE 3510-22-P

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[GRAPHIC] [TIFF OMITTED] TP19OC10.005

BILLING CODE 3510-22-C
    ASW sonar systems are deployed from certain classes of surface 
ships, submarines, helicopters, and fixed-wing maritime patrol aircraft 
(MPA).

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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. During an exercise, fixed-wing MPA may be used 
to deploy both active and passive sonobuoys to assist in locating and 
tracking submarines or ASW targets. Helicopters may also be used during 
an exercise to deploy both active and passive sonobuoys to assist in 
locating and tracking submarines or ASW targets, and to deploy dipping 
sonar. Submarines are equipped with both passive and active sonar 
sensors that may be used to locate and prosecute other submarines and/
or surface ships during the exercise. The platforms and systems used in 
ASW exercises are identified below.
    Surface Ship Sonar--A variety of surface ships participate in 
training events, including the Fast Frigate (FFG), the Guided Missile 
Destroyer (DDG), and the Guided Missile Cruiser (CG). These three 
classes of ships are equipped with active as well as passive tactical 
sonar 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 because 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 are classified but were 
modeled based on the required tactical training setting.
    Submarine Sonars--Submarines use sonar (e.g., AN/BQQ-10) 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 use 
high-frequency sonar (AN/BQS-15 or BQQ-24) for navigation safety, mine 
avoidance, and a fathometer that is not unlike a standard fathometer in 
source level or output. There is, at present, no mine training range in 
the GoA TMAA. Therefore, given their limited use and rapid attenuation 
as high frequency sources, the AN/BQS-15 and BQQ-24 are not expected to 
result in the take of marine mammals.
    Aircraft Sonar Systems--Aircraft sonar systems that would operate 
in the GoA TMAA include sonobuoys from fixed and rotary-wing aircraft 
and dipping sonar from helicopters. 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 also generate active acoustic 
signals. Dipping sonar is an active or passive sonar device lowered by 
cable from 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. Helicopters and MPA (P-3 or P-8 in approximately 2013) may 
deploy sonobuoys in the GoA TMAA during ASW training exercises.
    Extended Echo Ranging/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 has two components: An 
AN/SSQ-110A Sonobuoy, which generates an explosive sound impulse; and a 
passive receiver sonobuoy (SSQ-77), which ``listens'' 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. In other words, the equipment is 
not retrieved after deployment and, once deployed, it can be remotely 
controlled. For example, 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. Sixteen to twenty 
SSQ-110A source sonobuoys may be used in a typical exercise. Both 
charges of each sonobuoy would be detonated independently during the 
course of the training. The first detonation would be for tactical 
reasons--to locate the submarine; and the second occurs when the 
sonobuoy is 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.
    Multistatic Active Coherent (MAC) system-Formerly referred to as 
the Advanced Extended Echo Ranging (AEER) system, the proposed SSQ-125 
MAC sonobuoy system is operationally similar to the existing EER/IEER 
system. The MAC system will use the same Air Deployed Active Receiver 
(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/SSQ-110A as an impulsive 
source for the active acoustic wave, the MAC 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 MAC system will be assumed to occur at 25 
percent per year as follows: 2011--25 percent replacement; 2012--50 
percent replacement; 2013--75 percent replacement; 2014--100 percent 
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. With the exception of 
SINKEX, torpedoes will not be used in the GoA TMAA during the proposed 
training activities.
    Portable Undersea Tracking Range (PUTR)--The PUTR is a self-
contained, portable, undersea tracking capability that employs modern 
technologies to support coordinated undersea warfare training in 
numerous locations. The system tracks submarines, surface ships,

[[Page 64513]]

weapons, targets, and unmanned undersea vehicles and then distributes 
the data to a data processing and display system, either aboard ship or 
at a shore site. The PUTR may be deployed to support ASW or other 
training in the GoA TMAA. The PUTR would temporarily place hydrophones 
on the seafloor in areas 25-100 nm\2\ (46.3-185.2 km\2\) or smaller and 
provide high-fidelity feedback and scoring of crew performance during 
ASW training activities. No on-shore construction would take place. 
Seven electronics packages, each approximately 3 ft (0.9 m) long by 2 
ft (0.6 m) in diameter, would be temporarily installed on the seafloor 
by a range boat. The anchors used to keep the electronics packages on 
the seafloor consist of either concrete or sand bags, each of which are 
approximately 1.5 ft-by-1.5 ft (0.45 m-by-0.45 m) and 300 pounds (136 
kilograms). PUTR equipment can be recovered for maintenance or when 
training is completed. Two separate sound sources are associated with 
the operation of the PUTR:
    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 12.93 kHz sine 
wave in pulses with a maximum duty cycle of 30 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 4 hours each of the 20 PUTR operating days per year. Total time 
operated would be 80 hours annually.
    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 kHz, 17 kHz, or 40 kHz, at a source level of 190 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 20 days per year, for 4 
hours each day of use. Total time operated would be 80 hours annually.
    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. Two ASW training target types may be used in the 
TMAA: The MK-30, which is recovered after each use and the MK-39 
Expendable Mobile ASW Training Target (EMATT), which is not recovered. 
Under the proposed action, approximately 12 EMATTs may be expended 
annually during training in the TMAA. A small percentage of these 
EMATTS may be replaced by the more costly yet recoverable MK-30.
    As described above, ASW training exercises are the primary type of 
exercises that utilize MFAS and HFAS sources in the GoA TMAA. Unit 
level tracking and torpedo ASW exercises may occur over the course of 
several days during the proposed training period in the GoA TMAA. Under 
the Navy's preferred alternative, in a single year the GoA TMAA may 
have two exercises lasting up to 21 days, both of which may involve one 
ASW unit (aircraft, ship, or submarine) versus one target (usually a 
MK-39 EMATT or live submarine). 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. Use of torpedoes is 
not a proposed activity in the TMAA, with the exception of SINKEX. 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 (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, dipping sonar, variable-depth sonar, 
and sonobuoys for tracking.
    ASW training activities will take place during the summer months, 
in the form of one or two major exercises or focused activity periods. 
These exercises or activity periods would each last up to 21 days and 
consist of multiple component training activities. Unlike Navy Training 
activities in other areas, the GOA TMAA is not a Range Complex and as 
such, there are no other or ongoing small scale Navy Training 
activities conducted outside these activity periods. Descriptions of 
each ASW tracking exercise type are provided below.

Helicopter ASW TRACKEX

    A helicopter ASW TRACKEX typically involves one or two MH-60R 
helicopters using both passive and active sonar for tracking submarine 
targets. For passive tracking, the MH-60R may deploy patterns of 
passive sonobuoys to receive underwater acoustic signals, providing the 
helicopter crew with locating information on the target. Active 
sonobuoys may also be used. An active sonobuoy, as in any active sonar 
system, emits an acoustic pulse that travels through the water, 
returning echoes if any objects, such as a submarine, are within the 
range of acoustic detection. For active sonar tracking, the MH-60R crew 
will rely primarily on its AQS-22 Dipping Sonar. The sonar is lowered 
into the ocean while the helicopter hovers within 50 ft (15m) of the 
surface. Similar to the active sonobuoy, the dipping sonar emits 
acoustic energy and receives any returning echoes, indicating the 
presence of an underwater object. Use of dipping sonar has the 
potential to disturb a marine mammal or marine mammal stock resulting 
in MMPA Level B harassment as defined for military readiness 
activities.
    The target for this exercise is either an EMATT or live submarine 
which may be either nonevading and assigned to a specified track or 
fully evasive depending on the state of training of the helicopter 
crew. A Helicopter TRACKEX usually takes 2 to 4 hours. No torpedoes are 
fired during this exercise. A total of 192 AQS-22 ``dips'' annually 
were analyzed for potential acoustic impacts under the proposed 
training activities.

MPA <SUP>1</SUP> ASW TRACKEX

    During these exercises, a typical scenario involves a single MPA 
dropping sonobuoys, from an altitude below 3,000 ft (914 m), into 
specific patterns designed for both the anticipated threat submarine 
and the specific water conditions. These patterns vary in size and 
coverage area based on anticipated threat and water

[[Page 64514]]

conditions. Typically, passive sonobuoys will be used first, so the 
threat submarine is not alerted. Active sonobuoys will be used as 
required either to locate extremely quiet submarines or to further 
localize and track submarines previously detected by passive buoys. Use 
of sonobuoys has the potential to disturb a marine mammal or marine 
mammal stock resulting in MMPA Level B harassment as defined for 
military readiness activities.
---------------------------------------------------------------------------

    \1\ MPA currently refers to the P-3C Orion aircraft. The P-8 
Multi-Mission Maritime Aircraft is scheduled to replace the P-3C as 
the Navy's MPA.
---------------------------------------------------------------------------

    The MPA will typically operate below 3,000 ft (914 m) to drop 
sonobuoys, will sometimes be as low as 400 ft (122 m), then may climb 
to several thousand feet after the buoy pattern is deployed. The higher 
altitude allows monitoring of the buoys over a much larger search 
pattern area. The target for this exercise is either an EMATT or live 
submarine, which may be either non-evading and assigned to a specified 
track or fully evasive depending on the state of training of the MPA. 
An MPA TRACKEX usually takes 2 to 4 hours. The annual use of a total of 
266 DICASS sonobuoys was analyzed for potential acoustic impacts under 
the proposed training activities.

EER/IEER ASW Training Exercises

    This is an at-sea flying exercise designed to train MPA crews in 
the deployment and use of the EER/IEER sonobuoy systems. This system 
uses the SSQ-110A as the signal source and the SSQ-77 as the receiver 
buoy. This activity differs from the MPA ASW TRACKEX in that the SSQ-
110A sonobuoy uses two explosive charges per buoy for the acoustic 
source. Other active sonobuoys use an electrically generated ``ping.'' 
Use of explosive sonobuoys has the potential to disturb a marine mammal 
or marine mammal stock resulting in MMPA Level B harassment as defined 
for military readiness activities.
    A typical EER/IEER exercise lasts approximately 6 hours. The 
aircrew will first deploy 16 to 20 SSQ-110A sonobuoys and 16 to 20 
passive sonobuoys in 1 hour. For the next 5 hours, the sonobuoy charges 
will be detonated, while the EER/IEER system analyzes the returns for 
evidence of a submarine. This exercise may or may not include a 
practice target. For potential acoustic impacts, the annual deployments 
of 40 SSQ-110 (two explosions per buoy) sonobuoys were analyzed under 
the proposed training activities.
    In the future, the SSQ-125 MAC sonobuoy will be deployed in the GoA 
TMAA as a replacement for the SSQ-110 in EER/IEER exercises.

ASW TRACKEX (Surface Ship)

    Surface ships operating in the GoA TMAA would use hull-mounted 
active sonar to conduct ASW Tracking exercises. Typically, this 
exercise would involve the coordinated use of other ASW assets, to 
include MPA, helicopters, and other ships. A total of 578 hours of SQS-
53 and 52 hours of SQS-56 sonar annually were analyzed for potential 
acoustic impacts under the proposed training activities. Acoustic 
cumulative and synergistic effects are incorporated into the modeling 
as detailed in Appendix B of the Navy's LOA application (see 
Supplementary Information section for information on obtaining copies 
of supporting documents). Use of active sonar by surface ships for ASW 
has the potential to disturb a marine mammal or marine mammal stock 
resulting in MMPA Level B harassment as defined for military readiness 
activities.

ASW or Anti-Surface Warfare (ASUW) (Submarine)

    During these exercises, submarines use passive sonar sensors to 
search, detect, classify, localize, and track the threat submarine with 
the goal of developing a firing solution that could be used to launch a 
torpedo and destroy the threat submarine. However, no torpedoes are 
fired during this exercise. Submarines also use their high-frequency 
sonar for object avoidance and navigation safety. Sonar use by 
submarines has the potential to disturb a marine mammal or marine 
mammal stock resulting in MMPA Level B harassment as defined for 
military readiness activities.
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[[Page 64516]]

Activities Utilizing Underwater Detonations

    Underwater detonation activities can occur at various depths. They 
may include activities with detonations at or just below the surface 
(such as SINKEX or gunnery exercises (GUNEX)). When the weapons hit the 
target, 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 to explode 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 2. Additionally, successful 
hit rates are known to the Navy and are utilized in the effects 
modeling. Training events that involve explosives and underwater 
detonations are described below and summarized in Table 3.

                         Table 3--Sources of At-Sea Explosives Used in GoA TMAA for Which Take of Marine Mammals Is Anticipated
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                  Sub-TTS          TTS           Injury         Mortality
                                                                       Net     -------------------------------------------------------------  Exclusion
                        Ordnance/explosive                          explosive                                    50% TM       Onset massive   zone Used
                                                                    weight (in     177dB      182 SEL/23psi  rupture, 205db  lung injury or      (m)
                                                                      lbs.)                                   or 23 psi-ms      31 psi-ms
--------------------------------------------------------------------------------------------------------------------------------------------------------
5'' Naval gunfire................................................         9.54          413         227/269              43              23          549
76 mm Rounds.....................................................          1.6          168          95/150              19              13          549
MK-82............................................................          238         2720        1584/809             302             153          914
MK-83............................................................          574         4056       2374/1102             468             195          914
MK-84............................................................          945         5196       3050/1327             611             226          914
SSQ-110 IEER.....................................................            5           NA         325/271             155              76          914
MK-48............................................................          851           NA       2588/1198             762             442         1852
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table Also Indicates Range to Indicated Threshold and Size of Navy Exclusion Zone Used in Mitigation. Units Are Meters.

    Sinking Exercise (SINKEX)--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 hulks. 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. The 
Navy proposes to conduct one SINKEX during each summertime exercise in 
the GoA TMAA (maximum of two). Potential harassment would be from 
underwater detonation. SINKEX events have been conducted in the Pacific 
at Navy training range complexes off Southern California, the Pacific 
Northwest, Hawaii, and the Mariana Islands, 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 * * *'' (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 1-7 in the Navy's 
application indicates the typical ordnance that may be used in a 
SINKEX, which may include missiles, bombs, 5'' gunfire, and a single 
MK-48 torpedo. This table reflects the planning for weapons, which may 
be expended during one SINKEX in the GoA TMAA. This level of ordnance 
is expected for each of the two possible SINKEX events in the GoA TMAA. 
With the exception of the single 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)--These exercises 
train surface ship crews in high-speed surface engagement procedures 
against mobile (towed or self-propelled) seaborne targets. Both live 
and inert training rounds are used against the targets. The training 
consists of the pre-attack phase, including locating, identifying, and 
tracking the threat vessel, and the attack phase in which the missile 
is launched and flies to the target. In a live-fire event, aircraft 
conduct a surveillance flight to ensure that the range is clear of 
nonparticipating ships. These activities may occur within the GoA TMAA 
and have the potential to disturb a marine mammal or marine mammal 
stock resulting in MMPA Level B harassment as defined for military 
readiness activities.
    For S-S GUNEX from a Navy ship, gun crews engage surface targets at 
sea with their main battery 5-inch and 76mm guns as well as smaller 
surface targets with 25mm, 0.50-caliber (cal), or 7.62mm machine guns, 
with the goal of disabling or destroying the threat target. For a 
surface-to-surface GUNEX from a Navy small boat, the weapon used is 
typically a 0.50 cal, 7.62-mm, or 40-mm machine gun.
    The number of rounds fired depends on the weapon used for S-S 
GUNEX. For 0.50-cal, 7.62-mm, or 40-mm ordnance, the number of rounds 
is approximately 200, 800, and 10 rounds, respectively. For the ship 
main battery guns, the gun crews typically fire approximately 60 rounds 
of 5-inch or 76-mm ordnance during one exercise. These activities may 
occur within the GoA TMAA.
    Air-to-Surface Gunnery Exercise (A-S GUNEX)--Strike fighter 
aircraft and helicopter crews, including embarked

[[Page 64517]]

Naval Special Warfare (NSW) personnel use guns to attack surface 
maritime targets, day or night, with the goal of destroying or 
disabling enemy ships, boats, or floating or near-surface mines. These 
training activities have the potential to disturb a marine mammal or 
marine mammal stock resulting in MMPA Level B harassment as defined for 
military readiness activities.
    For fixed-wing A-S GUNEX, a flight of two F/A-18 aircraft will 
begin a descent to the target from an altitude of about 3,000 ft (914 
m) while still several miles away. Within a distance of 4,000 ft (1,219 
m) from the target, each aircraft will fire a burst of about 30 rounds 
before reaching an altitude of 1,000 ft (305 m), then break off and 
reposition for another strafing run until each aircraft expends its 
exercise ordnance allowance of about 250 rounds from its 20mm cannon.
    For rotary-wing A-S GUNEX, a single helicopter will carry several 
air crewmen needing gunnery training and fly at an altitude between 50 
and 100 ft (15 to 30 m) in a 300-ft (91-m) racetrack pattern around an 
at-sea target. Each gunner will expend about 200 rounds of 0.50 cal and 
800 rounds of 7.62-mm ordnance in each exercise. The target is normally 
a noninstrumented floating object such as an expendable smoke float, 
steel drum, or cardboard box, but may be a remote-controlled speed boat 
or jet ski type target. The exercise lasts about 1 hour and occurs 
within the GoA TMAA.
    Air-to-Surface Missile Exercise (A-S MISSILEX)--An air-to-surface 
MISSILEX involves fixed-winged aircraft and helicopter crews launching 
missiles at surface maritime targets, day and night, with the goal of 
training to destroy or disable enemy ships or boats. These activities 
may occur within the TMAA; however, all missile launches would be 
simulated; therefore, MISSILEX activities are not likely to disturb a 
marine mammal or marine mammal stock resulting in MMPA Level B 
harassment as defined for military readiness activities.
    For helicopter A-S MISSILEX, one or two MH-60R/S helicopters 
approach and acquire an at-sea surface target, which is then designated 
with a laser to guide an AGM-114 Hellfire missile to the target. The 
laser designator may be onboard the helicopter firing the hellfire, 
another helicopter, or another source. The helicopter simulates 
launching a missile from an altitude of about 300 ft (91 m) against a 
specially prepared target with an expendable target area on a 
nonexpendable platform. The platform fitted with the expendable target 
could be a stationary barge, a remote-controlled speed boat, or a jet 
ski towing a trimaran whose infrared signature has been augmented with 
a heat source (charcoal or propane) to better represent a typical 
threat vessel. All missile firings would be simulated.
    For an air-to-surface MISSILEX fired from fixed-wing aircraft, the 
simulated missile used is typically an AGM-84 Standoff Land Attack 
Missile-Expanded Response (SLAM-ER), an AGM-84 Harpoon, or an AGM-65 
Maverick. A flight of one or two aircraft approach an at-sea surface 
target from an altitude between 40,000 ft (12,192 m) and 25,000 ft 
(7,620 m) for SLAM-ER or Harpoon, and between 25,000 ft (7,620 m) and 
5,000 ft (1,524 m) for Maverick, complete the internal targeting 
process, and simulate launching the weapon at the target from beyond 
150 nm (278 km) for SLAM-ER and from beyond 12 nm (22 km) for Maverick. 
The majority of unit level exercises involve the use of captive carry 
(inert, no release) training missiles; the aircraft perform all 
detection, tracking, and targeting requirements without actually 
releasing a missile. These activities may occur within the GoA TMAA and 
all missile launches would be simulated.
    Air-to-Surface Bombing Exercise (BOMBEX)--During an air-to-surface 
BOMBEX, maritime patrol aircraft (MPA) or F/A-18 deliver free-fall 
bombs against surface maritime targets, with the goal of destroying or 
disabling enemy ships or boats.
    A flight of one or two aircraft will approach the target from an 
altitude of 15,000 ft (4,570 m) to less than 3,000 ft (914 m) while 
adhering to designated ingress and egress routes. Typical bomb release 
altitude is below 3,000 ft (914 m) and within a range of 1,000 yards 
(yd) (914 m) for unguided munitions, and above 15,000 ft (4,572 m) and 
in excess of 10 nm (18 km) for precision-guided munitions. Exercises at 
night will normally be done with captive carry (no drop) weapons 
because of safety considerations. Laser designators from aircraft 
releasing ordnance or a support aircraft are used to illuminate 
certified targets for use with lasers when using laser guided weapons. 
Bombs used could include BDU-45 (inert) or MK-82/83/84 (live and 
inert). These activities may occur within the GoA TMAA and have the 
potential to disturb a marine mammal or marine mammal stock resulting 
in MMPA Level B harassment as defined for military readiness 
activities. In the near future, the Navy will be transitioning all 
carrier based MK-80 series bombs to BLU 110, 111, and 117 live and 
inert bombs. The difference is that the BLU-series bombs contain 
insensitive (less likely to accidently explode) high explosives, which 
make them safer for carrier-based operations. All other attributes 
would remain the same.
    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 has two 
components: An AN/SSQ-110A Sonobuoy, which generates a sound similar to 
a ``sonar ping'' using a small explosive; and a passive AN/SSQ-77 
Sonobuoy, which ``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 MAC system (described in the sonar source section) will 
eventually replace the EER/IEER system and was analyzed for this 
proposed rule.

Vessel Movement

    Many of the proposed activities within the GoA TMAA involve 
maneuvers by various types of surface ships, boats, and submarines 
(collectively referred to as vessels). According to the Navy's 
application, up to seven Navy vessels (six surface ships and one 
submarine) may be operating within the GoA TMAA. In addition, the 
Navy's DEIS stated that under the preferred alternative (Alternative 2) 
19 contracted support vessels may also be operating within the GoA 
TMAA. Within the maximum two summer exercises, the length of the 
exercise, the number of vessels, and the allotted at-sea time within 
the GoA TMAA during an exercise will be variable between years. These 
variations cannot be predicted given unknowns including the 
availability of participants for the

[[Page 64518]]

annual exercise(s), which is a direct result of factors such as Navy 
responses to real-world events (e.g., tactical deployments, disaster 
relief, humanitarian assistance, etc.), planned and unplanned 
deployments, vessel availability due to funding and maintenance cycles, 
and logistic concerns with conducting an exercise in the GoA.
    Vessel movements have the potential to affect marine mammals by 
directly striking or disturbing individual animals. The probability of 
vessel and marine mammal interactions occurring in the GoA TMAA is 
dependent on several factors including numbers, types, and speeds of 
vessels; the regularity, duration, and spatial extent of activities; 
the presence/absence and density of marine mammals; and protective 
measures implemented by the Navy. During training activities, speeds 
vary and depend on the specific training activity. In general, Navy 
vessels move in a coordinated manner, but can be separated by many 
miles in distance. These activities are widely dispersed throughout the 
GoA TMAA, which is a vast area encompassing 42,146 nm\2\ (145,458 
km\2\). Consequently, the density of Navy vessels within the GoA TMAA 
at any given time is extremely low.
    Additional information on the Navy's proposed activities may be 
found in the LOA Application and the Navy's GoA TMAA DEIS.

Description of Marine Mammals in the Area of the Specified Activities

    Twenty-six marine mammal species or populations/stocks have 
confirmed or possible occurrence within or adjacent to the GoA, 
including seven species of baleen whales (mysticetes), 13 species of 
toothed whales (odontocetes), five species of seals (pinnipeds), and 
the sea otter (mustelid). Nine of these species are ESA-listed and 
considered depleted under the MMPA: Blue whale, fin whale, humpback 
whale, sei whale, sperm whale, North Pacific right whale, Cook Inlet 
beluga whale, Steller sea lion, and sea otter. Table 4 summarizes their 
abundance, Endangered Species Act (ESA) status, occurrence, density, 
and likely occurrence in the TMAA during the April to October 
timeframe. The sea otter 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

    Cook Inlet Beluga Whale--The likelihood of a Cook Inlet beluga 
whale (Delphinapterus leucas) occurring in the TMAA is extremely low. 
Only 28 sightings of beluga whales in the GoA have been reported from 
1936 to 2000 (Laidre et al., 2000). The nearest beluga whales to the 
TMAA are in Cook Inlet with a 2008 abundance estimate of 375 whales in 
the Cook Inlet stock (NMFS 2008). In October 2008, the Cook Inlet 
beluga whale distinct population segment was listed as endangered under 
the ESA (73 FR 62919, October 22, 2008). Prior to listing, the 
population had been designated as depleted under the MMPA (NMFS, 2008). 
Cook Inlet is approximately 70 nm (129.6 km) from the nearest edge of 
the TMAA and the Cook Inlet beluga whales do not leave the waters of 
Cook Inlet (NMFS, 2007, 2008). Based on this information, it is highly 
unlikely for a Cook Inlet beluga whale to be present in the action 
area. Consequently, this distinct population segment will not be 
considered in the remainder of this analysis.
    False Killer Whale--The likelihood of a false killer whale 
(Pseudorca crassidens) being present in the TMAA is extremely low. 
False killer whales are found in tropical and temperate waters, 
generally between 50[deg] S and 50[deg] N latitude (Baird et al., 1989; 
Odell and McClune, 1999). The southernmost point boundary of the TMAA 
is well north of 55[deg] N latitude. There have been records of false 
killer whale sightings as far north as the Aleutian Islands and Prince 
William Sound in the past (Leatherwood et al., 1988). In addition, a 
false killer whale was sighted in May 2003 near Juneau, but this was 
considered to be far north of its normal range (DoN, 2006). There are 
no abundance estimates available for this

[[Page 64520]]

species in the NMFS stock assessment report for this area of the 
Pacific. In summary, false killer whales are considered extralimital to 
the TMAA and will not be considered further in this analysis.
    Northern Right Whale Dolphin--The likelihood of a northern right 
whale dolphin (Lissodelphis borealis) occurring in the TMAA is 
extremely low. This species occurs in North Pacific oceanic waters and 
along the outer continental shelf and slope in cool temperate waters 
colder than 20[deg] C. This species is distributed approximately from 
30[deg] N to 55[deg] N and 145[deg] W to 118[deg] E (both south and 
east of the TMAA). There are two records of northern right whale 
dolphins in the GoA (one just south of Kodiak Island), but these are 
considered extremely rare (DoN, 2006). There are no abundance estimates 
for this species in the NMFS stock assessment report for this area of 
the Pacific. Given the extremely low likelihood of this species 
occurrence in the action area, the northern right whale dolphin will 
not be considered further in this analysis.
    Risso's Dolphin--The likelihood of Risso's dolphin (Grampus 
griseus) occurring in the action area is extremely low. The Risso's 
dolphin is distributed worldwide in tropical to warm-temperate waters, 
roughly between 60[deg] N and 60[deg] S, where surface water 
temperature is usually greater than 10[deg] C (Kruse et al., 1999). The 
average sea surface temperature for the GoA is reported to be 
approximately 9.6[deg] C and has undergone a warming trend since 1957 
(Aquarone and Adams, 2008). The average summer temperature within the 
upper 328 ft (100 m) of the TMAA is approximately 11[deg] C based on 
data as presented in the modeling analysis undertaken by the Navy. In 
the eastern Pacific, Risso's dolphins range from the GoA to Chile 
(Leatherwood et al., 1980; Reimchen, 1980; Braham, 1983; Olavarria et 
al., 2001). Water temperature appears to be a factor that affects the 
distribution of Risso's dolphins in the Pacific (Leatherwood et al., 
1980; Kruse et al., 1999). Risso's dolphins are expected to be 
extralimital in the TMAA. They prefer tropical to warm temperate waters 
and have seldom been sighted in the cold waters of the GoA. Records of 
Risso's dolphins near the TMAA include sightings near Chirikof Island 
(southwest of Kodiak Island) and offshore in the GoA, just south of the 
TMAA boundary (Consiglieri et al., 1980; Braham, 1983). Given the 
extremely low likelihood of this species occurrence in the action area, 
the Risso's dolphin will not be considered further in this analysis.
    Short-Finned Pilot Whale--Short-finned pilot whales (Globicephala 
macrohynchus) are not expected to occur in the GoA TMAA. This species 
is found in tropical to warm temperate seas, generally in deep offshore 
areas, and they do not usually range north of 50[deg] N (DoN, 2006). 
There are two records of this species in Alaskan waters. In 1937, a 
short-finned pilot whale was taken near Katanak on the Alaska Peninsula 
and a group of five short-finned pilot whales were sighted just 
southeast of Kodiak Island in May 1977 (DoN, 2006). There are no 
abundance estimates available for this species in the NMFS stock 
assessment report for this area of the Pacific. Given the extremely low 
likelihood of this species' occurrence in the action area, the short-
finned pilot whale will not be considered further in this analysis.
    The Navy has compiled information on the abundance, behavior, 
status and distribution, and vocalizations of marine mammal species in 
the GoA TMAA 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 designated 
stocks of marine mammals in the waters surrounding the GoA TMAA and, 
therefore, compiles stock assessment reports for this area. This 
information may be viewed in the Navy's LOA application and/or the 
Navy's DEIS for the GoA TMAA (see Availability), and is incorporated by 
reference herein.
    There are no designated marine mammal critical habitats or known 
foraging areas within the GoA TMAA; however, critical habitats for two 
ESA-listed species have been designated in the vicinity of the GoA 
TMAA. On April 8, 2008, NMFS designated two areas as North Pacific 
right whale critical habitat--one in the GoA and one in the Bering Sea 
(73 FR 19000). The GoA critical habitat is located approximately 16 nm 
(30 km) west of the southwest corner of the TMAA. NMFS designated 
critical habitat for Steller sea lions on August 27, 1993 (58 FR 
45269). For the western Distinct Population Segment (DPS), ``aquatic 
zone'' critical habitat surrounding haulouts and rookeries extends 20 
nm (37 km) seaward in state and federally managed waters, portions of 
which are adjacent to the TMAA.
    Much is unknown about the feeding habits of the dolphin and 
porpoise species in the GoA TMAA, but they are thought to feed 
opportunistically throughout their range (like better studied species 
and stocks are known to do) and possibly throughout the year. Even less 
is known about the feeding habits of beaked whales. Baleen whales and 
sperm whales are thought to forage seasonally in areas within and 
around the GoA TMAA. For example, Moore et al. (2007) provided evidence 
of a year-round occurrence of gray whales and a noteworthy feeding area 
in the northeastern GoA (southeast of Kodiak Island).

Marine Mammal Hearing and Vocalizations

    Cetaceans have an auditory anatomy that follows the basic mammalian 
pattern, with some changes to adapt to the demands of hearing 
underwater. The typical mammalian ear is divided into an outer ear, 
middle ear, and inner ear. The outer ear is separated from the inner 
ear by a tympanic membrane, or eardrum. In terrestrial mammals, the 
outer ear, eardrum, and middle ear transmit airborne sound to the inner 
ear, where the sound waves are propagated through the cochlear fluid. 
Since the impedance of water is close to that of the tissues of a 
cetacean, the outer ear is not required to transduce sound energy as it 
does when sound waves travel from air to fluid (inner ear). Sound waves 
traveling through the inner ear cause the basilar membrane to vibrate. 
Specialized cells, called hair cells, respond to the vibration and 
produce nerve pulses that are transmitted to the central nervous 
system. Acoustic energy causes the basilar membrane in the cochlea to 
vibrate. Sensory cells at different positions along the basilar 
membrane are excited by different frequencies of sound (Pickles, 1998). 
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 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

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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 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 whale social 
vocalizations is concentrated near 10 kHz, with source levels for 
whistles as high as 100 to 180 dB re 1 [micro]Pa at 1 m (Richardson et 
al., 1995). No odontocete has been shown audiometrically to have acute 
hearing (<80 dB re 1 [micro]Pa) below 500 Hz (DoN, 2001). Sperm whales 
produce clicks, which may be used to echolocate (Mullins et al., 1988), 
with a frequency range from less than 100 Hz to 30 kHz and source 
levels up to 230 dB re 1 [micro]Pa 1 m or greater (Mohl et al., 2000).
    Table 5a and Table 5b list the species found in the GoA TMAA and 
include a summary of their vocalizations, if available. 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. Furthermore, 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).
    Density is nearly always reported for an area (e.g., animals per km 
\2\). Analyses of survey results using distance sampling techniques 
include correction factors for animals at the surface but not seen as 
well as animals below the surface and not seen. Therefore, although the 
area (e.g., km\2\) appears to represent only the surface of the water 
(two-dimensional), density actually implicitly includes animals 
anywhere within the water column under that surface area. In addition, 
density assumes that animals are uniformly distributed within the 
prescribed area, even though this is likely a rare occurrence. Marine 
mammals are usually concentrated in areas of greater importance, such 
as areas of high productivity, low predation, safe calving, etc. 
Density can occasionally be calculated for smaller areas that are 
regularly used by marine mammals, but more often than not, there are 
insufficient data to calculate density for small areas. Therefore, 
assuming an even distribution within the prescribed area remains the 
norm.
    Recent survey data for marine mammals in the GoA is limited and 
most survey efforts were localized and extremely nearshore. In addition 
to the visual surveys, there is evidence of several species based on 
acoustic studies, but these do not provide measurements of abundance 
(e.g., Stafford, 2009).
    In April 2009, the Navy funded and NMFS conducted the Gulf of 
Alaska Line-Transect Survey (GOALS) to address the data needs for this 
analysis (Rone et al., 2009). Line-transect survey visual data to 
support distance sampling statistics and acoustic data were collected 
over a 10-day period both within and outside the TMAA. This survey 
resulted in sightings of several species and allowed for the derivation 
of densities for fin and humpback whale (Rone et al., 2009). In 
addition to this latest survey, two previous vessel surveys conducted 
in the nearshore region of the TMAA were also used to derive the 
majority of the density data used in acoustic modeling for this 
analysis. The methods used to derive density estimates for all 
remaining species in the TMAA are detailed in Appendix B of the LOA 
application and summarized below.
    Zerbini et al. (2006) conducted dedicated vessel surveys for large 
whales in summer 2001-2003 from Resurrection Bay on the Kenai Peninsula 
to Amchitka Island in the Aleutian Islands. Survey effort near the TMAA 
was nearshore (within approximately 46 nm (85 km) of shore), and is 
delineated as ``Block 1'' in the original paper. Densities for this 
region were published for fin and humpback whales.
    Waite (2003) conducted vessel surveys for cetaceans near Kenai 
Peninsula, within Prince William Sound and around Kodiak Island, during 
acoustic-trawl surveys for pollock in summer 2003. Surveys extended 
offshore to the 1,000 m isobaths and therefore overlapped with some of 
the TMAA. Waite (2003) did not calculate densities, but did provide 
some of the elements necessary for calculating density (please see 
Appendix B of the LOA application for more information).
    Mysticetes occurring in the GoA include blue, fin, gray, humpback, 
minke, North Pacific right, and sei whales (Angliss and Allen, 2008; 
Rone et al., 2009). Blue, North Pacific right, and sei whales are 
considered rare, and are included here only for discussion purposes due 
to their designations as ``depleted'' under the MMPA and ``endangered'' 
under the ESA.
    Gray whale density was calculated from data obtained during 
nearshore feeding studies in the GoA. Gray whales are found almost 
exclusively in near shore areas; therefore, they would not be expected 
to be found in the majority of the TMAA (>50 nm (93 km) offshore and 
>5,997 ft (1,828 m) depth) (DoN, 2006). The recent 2009 survey 
encountered one group of two gray whales on the shelf within the 
western edge of the TMAA and two groups well outside the TMAA near 
shore at Kodiak Island (Rone et al., 2009).
    Odontocetes occurring regularly include sperm whale, Cuvier's, 
Baird's, and Stejneger's beaked whales, killer whale, Pacific white-
sided dolphin, and Dall's porpoise (Angliss and Allen, 2008; Rone et 
al., 2009). In Alaska waters, harbor porpoise inhabit coastal waters 
where depths are less than 328 ft (100 m) in depth (DoN, 2006; Angliss 
and Allen, 2008). The majority of the TMAA is well offshore of the 
normal habitat range for harbor porpoise. There is no density data 
available for this species in the nearshore portion of the TMAA that 
overlaps the harbor porpoise range. An estimated quantification of 
impacts for harbor porpoise was, however, undertaken as described in 
the Potential Effects of Specified Activities on Marine Mammals 
section.
    Pinnipeds occurring regularly include Steller sea lion, northern 
fur seal, and northern elephant seal. The range of California sea lions 
extends as far north as the Pribolof Islands in the Bering Sea. Tagging 
data indicate that most northern fur seal foraging and migration takes 
place to the west of the TMAA (Ream et al., 2005), although the derived 
density for this species assumed the population would be present in the 
area for modeling purposes. Harbor seals are primarily a coastal 
species and are rarely found more than 12 mi (20 km) from shore (DoN, 
2006). Harbor seals should be very rare in the TMAA and there was no 
attempt to model for this species.
    Pinniped at-sea density is not often available because pinniped 
abundance is obtained via shore counts of animals at known rookeries 
and haulouts. Lacking any other available means of quantification, 
densities of pinnipeds were derived using shore counts. Several 
parameters were identified for pinnipeds from the literature, including 
area of stock occurrence, number of animals (which may vary seasonally) 
and season, and those parameters were then used to calculate density. 
Once density per ``pinniped season'' was determined, those values were 
prorated to fit the warm water (June through October) and cold water 
(November through May) seasons. Determining density in this manner is 
risky because the parameters used usually contain error (e.g., 
geographic range is not exactly known and needs to be estimated and 
abundance estimates usually have large variances). As is true of all 
density estimates, they assume that the animals are always distributed 
evenly within an area which is likely never true.

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

[[Page 64525]]

through a unit area in a specified direction and is expressed in watts 
per square meter (W/m\2\). Acoustic intensity is rarely measured 
directly, but rather from ratios of pressures; the standard reference 
pressure for underwater sound is 1 microPascal ([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 10 dB). 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. Because of the 
different densities of air and water and the different decibel 
standards (i.e., reference pressures) in air and water, a sound with 
the same intensity (i.e., power) in air and in water would be 
approximately 63 dB quieter in air. Thus, a sound that measures 160 dB 
underwater would have the same approximate effective intensity as a 
sound that is 97 dB 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 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 3 km 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

[[Page 64526]]

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 activities in the GoA TMAA 
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 GoA TMAA 
DEIS, including ship strike, aerial overflights, ship noise and 
movement, and others, and, in consultation with NMFS as a cooperating 
agency for the GoA TMAA DEIS, has determined that take of marine 
mammals incidental to these non-acoustic components of the GoA TMAA 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 GoA TMAA.
    For the purpose of MMPA authorizations, NMFS' effects assessments 
serve four primary purposes: (1) To help identify the permissible 
methods of taking, or 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.
    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 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 11 of NMFS' 
June 28, 2010, biological opinion for the Mariana Islands Range Complex 
(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 (e.g., 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 TS: Effects to sensory hair cells in the inner ear 
that reduce their sensitivity, modification of the chemical environment 
within the sensory cells, residual muscular activity in the middle ear, 
displacement of certain inner ear membranes, increased

[[Page 64527]]

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 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 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 
(e.g., 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) speculates that 
rapid ascent to the surface following exposure to a startling sound

[[Page 64528]]

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, the detection of frequencies above those of the 
masking stimulus decreases. This principle is expected to apply to 
marine mammals as well because of common biomechanical cochlear 
properties across taxa.
    Richardson et al. (1995b) argued that the maximum radius of 
influence of an industrial noise (including broadband low-frequency 
sound transmission) on a marine mammal is the distance from the source 
to the point at which the noise can barely be heard. This range is 
determined by either the hearing sensitivity of the animal or the 
background noise level present. Industrial masking is most likely to 
affect some species' ability to detect communication calls and natural 
sounds (i.e., surf noise, prey noise, etc.) (Richardson et al., 1995).
    The echolocation calls of toothed whales are subject to masking by 
high-frequency sound. Human data indicate that low-frequency sounds 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 higher 
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 with the 
frequencies of the MFAS/HFAS sources used in the Navy's MFAS/HFAS 
training exercises (although some mysticetes' 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 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 adjustments to vocalization characteristics such as the frequency 
structure, amplitude, temporal structure and temporal delivery.
    Many animals will combine several of these strategies to compensate 
for high levels of background noise.

[[Page 64529]]

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 to impair communication between animals. Most 
animals that vocalize have evolved strategies to compensate for the 
effects of short-term or temporary increases in background or ambient 
noise on their songs or calls. Although the fitness consequences of 
these vocal adjustments remain unknown, like most other trade-offs 
animals must make, some of these strategies probably come at a cost 
(Patricelli et al., 2006). For example, vocalizing more loudly in noisy 
environments may have energetic costs that decrease the net benefits of 
vocal adjustment and alter a bird's energy budget (Brumm, 2004; Wood 
and Yezerinac, 2006). Shifting songs and calls to higher frequencies 
may also impose energetic costs (Lambrechts, 1996).

Stress Responses

    Classic stress responses begin when an animal's central nervous 
system perceives a potential threat to its homeostasis. That perception 
triggers stress responses regardless of whether a stimulus actually 
threatens the animal; the mere perception of a threat is sufficient to 
trigger a stress response (Moberg, 2000; Sapolsky et al., 2005; Seyle, 
1950). Once an animal's central nervous system perceives a threat, it 
mounts a biological response or defense that consists of a combination 
of the four general biological defense responses: Behavioral responses, 
autonomic nervous system responses, neuroendocrine responses, or immune 
responses.
    In the case of many stressors, an animal's first and 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), altered metabolism (Elasser et al., 2000), reduced 
immune competence (Blecha, 2000), and behavioral disturbance. Increases 
in the circulation of glucocorticosteroids (cortisol, corticosterone, 
and aldosterone in marine mammals; see Romano et al., 2004) have been 
equated with stress for many years.
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and distress is the biotic cost 
of the response. During a stress response, an animal uses glycogen 
stores that can be quickly replenished once the stress is alleviated. 
In such circumstances, the cost of the stress response would not pose a 
risk to the animal's welfare. However, when an animal does not have 
sufficient energy reserves to satisfy the energetic costs of a stress 
response, energy resources must be diverted from other biotic 
functions, which impair 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 fitness will suffer. In these cases, 
the animals will have entered a pre-pathological or pathological state 
which is called ``distress'' (sensu Seyle, 1950) or ``allostatic 
loading'' (sensu McEwen and Wingfield, 2003). This pathological state 
will last until the animal replenishes its biotic reserves sufficient 
to restore normal function. Note that these examples involved a long-
term (days or weeks) stress response exposure to stimuli.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses have also been documented 
fairly well through controlled 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 anthropogenic sound exposure, 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 and mid-frequency sounds.
    For example, Jansen (1998) reported on the relationship between 
acoustic exposures and physiological responses that are indicative of 
stress responses in humans (e.g., elevated respiration and increased 
heart rates). Jones (1998) reported on reductions in human performance 
when faced with acute, repetitive exposures to acoustic disturbance. 
Trimper et al. (1998) reported on the physiological stress responses of 
osprey to low-level aircraft noise while Krausman et al. (2004) 
reported on the auditory and 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 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

[[Page 64530]]

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 
the 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 
subsections 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 
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 
the speed of approach, all 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 of western gray 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 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 
local seismic activities. 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 foraging 
ground and the whales left the area and moved farther south to the Sea 
of Okhotsk. They only returned to the foraging ground several days 
after the seismic activities stopped. The potential fitness 
consequences of displacing these

[[Page 64531]]

whales, especially mother-calf pairs and ``skinny whales,'' outside of 
their normal feeding area are 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. Avoidance is qualitatively different 
from the flight response, but also differs in the magnitude of the 
response (i.e., directed movement, rate of travel, etc.). Oftentimes, 
avoidance is temporary and animals return to the area once the noise 
has ceased. However, longer term displacement is possible and can lead 
to changes in abundance or distribution patterns of the species in the 
affected region if animals 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 long-term or 
repetitive/chronic displacement for some dolphin groups and for 
manatees has been suggested to result from 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) 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 the following behaviors: immediately swimming away 
(horizontally) from the source of the sound; engaging in a series of 
erratic and frequently deep dives that seemed to take it below the 
sound field; or swimming away while engaged in a series of erratic and 
frequently deep dives. Although the sample sizes in this study are too 
small to support statistical analysis, the behavioral responses of the 
orcas were consistent with the results of other studies.
    In 2007, the first in a series of behavioral response studies 
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

[[Page 64532]]

robust and definitive conclusions can be drawn (NMFS, 2008a).
    The preliminary BRS-08 cruise report has been published. Although 
the extensive data sets emerging from this study will require detailed 
analysis, researchers have identified an emerging pattern of responses. 
For example, Blainville's beaked whales--a resident species within the 
study area--appear to be sensitive to noise at levels well below 
expected TTS (~160 dB re1[micro]Pa). This sensitivity is manifest by an 
adaptive movement away from a sound source. This response was observed 
irrespective of whether the signal transmitted was within the band 
width of MFAS, which suggests that beaked whales may not respond to the 
specific sound signatures. Instead, they may be sensitive to any pulsed 
sound from a point source in this frequency range. The response to such 
stimuli appears to involve maximizing the distance from the sound 
source (NMFS, 2008b).
    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 more directly approached groups of these animals 
(Ward et al., 1999). Bald eagles (Haliaeetus leucocephalus) perched on 
trees alongside a river were also more likely to flee from a paddle 
raft when their perches were closer to the river or were closer to the 
ground (Steidl and Anthony, 1996).
    Breathing--Variations in respiration naturally occur with different 
behaviors. Variations in respiration rate as a function of acoustic 
exposure can 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 
foraging 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, exposing 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 of 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 respond to 
sonar transmissions at lower received levels and move to avoid 
additional exposure or exposures at higher received levels (Richardson 
et al., 1995).
    It is difficult to distinguish between animals that continue their 
pre-disturbance behavior without stress responses, animals that 
continue their behavior but experience stress responses (that is, 
animals that cope with disturbance), and animals that habituate to 
disturbance (that is, they may have experienced low-level stress 
responses initially, but those responses abated over time). Watkins 
(1986) reviewed data on the behavioral reactions of fin, humpback, 
right and minke whales that were exposed to continuous, broadband low-
frequency shipping and industrial noise in Cape Cod Bay. He concluded 
that underwater sound was the primary cause of behavioral reactions in 
these species of whales and that the whales responded behaviorally to 
acoustic stimuli within their respective hearing ranges. Watkins also 
noted that whales showed the strongest behavioral reactions to sounds 
in the 15 Hz to 28 kHz range, although negative reactions (avoidance, 
interruptions in vocalizations, etc.) were generally associated with 
sounds that were either unexpected, too loud, suddenly louder or 
different, or perceived as being associated with a potential threat 
(such as an approaching ship on a collision course). In particular, 
whales seemed to react negatively when they were within 100 m of the 
source or when received levels increased suddenly in excess of 12 dB 
relative to ambient sounds. At other times, the whales ignored the 
source of the signal and all four species habituated to these sounds.
    Nevertheless, Watkins concluded that whales ignored most sounds in 
the background of ambient noise, including sounds from distant human 
activities even though these sounds may have had considerable energies 
at frequencies well within the whales' range of hearing. Further, he 
noted that of the whales observed, fin whales were the most sensitive 
of the four species, followed by humpback whales; right whales were the 
least likely to be disturbed and generally did not react to low-
amplitude engine noise. By the end of his period of study, Watkins 
(1986) concluded that fin and humpback whales have generally habituated 
to the continuous and broad-band noise of Cape Cod Bay while right 
whales did not appear to change their response. As mentioned above, 
animals that habituate to a particular disturbance may have experienced 
low-level stress responses initially, but those responses abated over 
time. In most cases, this likely means a lessened immediate potential 
effect from a disturbance; however, 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) reports the results of 
the efforts of a panel of experts in acoustic research

[[Page 64533]]

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 [mu]Pa range and an 
increasing likelihood of avoidance and other behavioral effects in the 
120 to 160 dB range. As mentioned earlier, though, contextual variables 
play a very important role in the reported responses and the severity 
of effects are not linear when compared to received level. Also, few of 
the laboratory or field datasets had common conditions, behavioral 
contexts, or sound sources, so it is not surprising that responses 
differ.
    The studies that address responses of mid-frequency cetaceans to 
non-pulse sounds include data gathered both in the field and the 
laboratory and related to several different sound sources (of varying 
similarity to MFAS/HFAS) including: Pingers, drilling playbacks, ship 
and ice-breaking noise, vessel noise, Acoustic Harassment Devices 
(AHDs), Acoustic Deterrent Devices (ADDs), MFAS, and non-pulse bands 
and tones. Southall et al. (2007) were unable to come to a clear 
conclusion regarding the results of these studies. In some cases, 
animals in the field showed significant responses to received levels 
between 90 and 120 dB, while in other cases these responses were not 
seen in the 120 to 150 dB range. The disparity in results was likely 
due to contextual variation and the differences between the results in 
the field and laboratory data (animals typically responded at lower 
levels in the field).
    The studies that address responses of high-frequency cetaceans to 
non-pulse sounds include data gathered both in the field and the 
laboratory and related to several different sound sources (of varying 
similarity to MFAS/HFAS), including: Pingers, AHDs, and various 
laboratory non-pulse sounds. All of these data were collected from 
harbor porpoises. Southall et al. (2007) concluded that the existing 
data indicate that harbor porpoises are likely sensitive to a wide 
range of anthropogenic sounds at low received levels (~90-120 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.
    The studies that address the responses of pinnipeds in water to 
non-pulse sounds include data gathered both in the field and the 
laboratory and related to several different sound sources (of varying 
similarity to MFAS/HFAS), including: AHDs, ATOC, various non-pulse 
sounds used in underwater data communication, underwater drilling, and 
construction noise. Few studies exist with enough information to 
include them in the analysis. The limited data suggest that exposures 
to non-pulse sounds between 90 and 140 dB generally do not result in 
strong behavioral responses of 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 an effort to develop acoustic criteria.
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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 few 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 of 
animals shifting from one behavioral state (e.g., resting or foraging) 
to another behavioral state (e.g., avoidance or escape behavior) 
because of human disturbance or disturbance stimuli.
    One consequence of behavioral avoidance results from the changes in 
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 speeds that minimize the 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). When vessels approached, the amount of time 
cows and calves spent resting and milling declined significantly, 
respectively. These results are similar to those reported by Scheidat 
et al. (2004) for the humpback whales they observed off the coast of 
Ecuador.
    Constantine and Brunton (2001) reported that bottlenose dolphins in 
the Bay of Islands, New Zealand only engaged in resting behavior 5 
percent of the time when vessels were within 300 m compared with 83 
percent 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 (e.g., 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 treating the stimulus as a 
disturbance and responding 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 attend to 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 
(e.g., multiple surface vessels), or when they co-occur with times that 
an animal perceives increased risk (e.g., when they are giving birth or 
accompanied by a calf). Most of the published literature, however, 
suggests that direct approaches will increase the amount of time 
animals will dedicate to being vigilant. For example, bighorn sheep and 
Dall's sheep dedicated more time to being vigilant, and less time 
resting or foraging, when aircraft made direct

[[Page 64535]]

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 
physical 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 percent reproductive success rate 
compared with geese in disturbed habitat (being consistently scared off 
the fields on which they were foraging) which did not gain mass and had 
a 17 percent reproductive success rate. Similar reductions in 
reproductive success have been reported for mule deer (Odocoileus 
hemionus) disturbed by all-terrain vehicles (Yarmoloy et al., 1988), 
caribou disturbed by seismic exploration blasts (Bradshaw et al., 
1998), and caribou disturbed by low-elevation military jet flights 
(Luick et al., 1996; Harrington and Veitch, 1992). Similarly, a study 
of elk (Cervus elaphus) that were disturbed experimentally by 
pedestrians concluded that the ratio of young to mothers was inversely 
related to disturbance rate (Phillips and Alldredge, 2000).
    The primary mechanism by which increased vigilance and disturbance 
appear to affect the fitness of individual animals is by disrupting an 
animal's time budget and, as a result, reducing the time they might 
spend foraging and resting (which increases an animal's activity rate 
and energy demand). 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; NMFS, 2007). 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 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 
whale (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 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 2008 Rim of the Pacific (RIMPAC) exercises, between 150 and 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-km strand of the

[[Page 64536]]

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 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 and March 16, 
2000. The ships, which operated both AN/SQS-53 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 ten were returned to the water alive (though their ultimate 
fate is unknown). As discussed in the Bahamas report (DOC/DON, 2001), 
there is no likely association between the minke whale and spotted 
dolphin strandings and the operation of MFAS.
    Necropsies were performed on five of the stranded beaked whales. 
All five necropsied beaked whales were in good body condition, showing 
no signs of infection, disease, ship strike, blunt trauma, or fishery 
related injuries, and three still had food remains in their stomachs. 
Auditory structural damage was discovered in four of the whales, 
specifically bloody effusions or hemorrhaging around the ears. 
Bilateral intracochlear and unilateral temporal region subarachnoid 
hemorrhage, with blood clots in the lateral ventricles, were found in 
two of the whales. Three of the whales had small hemorrhages in their 
acoustic fats (located along the jaw and in the melon).
    A comprehensive investigation was conducted and all possible causes 
of the stranding event were considered, whether they seemed likely at 
the outset or not. Based on the way in which the strandings coincided 
with ongoing naval activity involving tactical MFAS use, in terms of 
both time and geography, the nature of the physiological effects 
experienced by the dead animals, and the absence of any other acoustic 
sources, the investigation team concluded that MFAS aboard U.S. Navy 
ships that were in use during the active sonar exercise in question 
were the most plausible source of this acoustic or impulse trauma to 
beaked whales. This sound source was active in a complex environment 
that included the presence of a surface duct, unusual and steep 
bathymetry, a constricted channel with limited egress, intensive use of 
multiple, active sonar units over an extended period of time, and the 
presence of beaked whales that appear to be sensitive to the 
frequencies produced by these active sonars. The investigation team 
concluded that the cause of this stranding event was the confluence of 
the Navy MFAS and these contributory factors working together, and 
further recommended that the Navy avoid operating MFAS in situations 
where these five factors would be likely to occur. This report does not 
conclude that all five of these factors must be present for a stranding 
to occur, nor that beaked whales are the only species that could 
potentially be affected by the confluence of the other factors. Based 
on this, NMFS believes that the operation of MFAS in situations where 
surface ducts exist, or in marine environments defined by steep 
bathymetry and/or constricted channels may increase the likelihood of 
producing a sound field with the potential to cause cetaceans 
(especially beaked whales) to strand, and therefore, suggests the need 
for increased vigilance while operating MFAS in these areas, especially 
when beaked whales (or potentially other deep divers) are likely 
present.
Madeira, Spain (2000)
    From May 10 to May 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 and 80 
warships, took place in Portugal between May 2 and May 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

[[Page 64537]]

intracranial hemorrhage similar to that which was observed in the 
whales that stranded in the Bahamas event (Cox et al., 2006). There 
were no signs of blunt trauma, and no major fractures (Woods Hole 
Oceanographic Institution, 2005). The cranial sinuses and airways were 
found to be clear with little or no fluid deposition, which may 
indicate good preservation of tissues (Woods Hole Oceanographic 
Institution, 2005).
    Several observations on the Madeira stranded beaked whales, such as 
the pattern of injury to the auditory system, are the same as those 
observed in the Bahamas strandings. Blood in and around the eyes, 
kidney lesions, pleural hemorrhages, and congestion in the lungs are 
particularly consistent with the pathologies from the whales stranded 
in the Bahamas, and are consistent with stress and pressure-related 
trauma. The similarities in pathology and stranding patterns between 
these two events suggest that a similar pressure event may have 
precipitated or contributed to the strandings at both sites (Woods Hole 
Oceanographic Institution, 2005).
    Even though no definitive causal link can be made between the 
stranding event and naval exercises, certain conditions may have 
existed in the exercise area that, in their aggregate, may have 
contributed to the marine mammal strandings (Freitas, 2004): Exercises 
were conducted in areas of at least 547 fathoms (1,000 m) depth near a 
shoreline where there is a rapid change in bathymetry on the order of 
547 to 3,281 (1,000 to 6,000 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 (1,000 m) within a few hundred meters of the coastline 
(Fernandez et al., 2005). On September 24, 2002, 14 beaked whales were 
found stranded on Fuerteventura and Lanzarote Islands in the Canary 
Islands (International Council for Exploration of the Sea, 2005a). 
Seven whales died, while the remaining seven live whales were returned 
to deeper waters (Fernandez et al., 2005). Four beaked whales were 
found stranded dead over the next 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).
    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 the 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 alive on the evening of January 26. 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. Between January 25 and 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 (1,000 m) depth near a shoreline where there is a 
rapid change in bathymetry on the order of 547 to 3,281 fathoms (1,000 
to 6,000 m) occurring across a relatively short horizontal distance 
(Freitas, 2004); multiple ships (in this instance, five) were operating 
MFAS in the same area over extended periods of time (in this case, 20 
hrs) in close proximity; and exercises took place in an area surrounded 
by landmasses, or in an embayment. Exercises involving multiple ships 
employing MFAS near land may have produced sound directed towards a 
channel or embayment that may have cut off the lines of egress for

[[Page 64538]]

the affected marine mammals (Freitas, 2004).
Hanalei Bay (2004)
    On July 3 and 4, 2004, approximately 150 to 200 melon-headed whales 
occupied the shallow waters of the Hanalei Bay, Kaua'i, Hawaii for over 
28 hrs. Attendees of a canoe blessing observed the animals entering the 
Bay in a single wave formation at 7 a.m. on July 3, 2004. The animals 
were observed moving back into the shore from the mouth of the Bay at 9 
a.m. The usually pelagic animals milled in the shallow bay and were 
returned to deeper water with human assistance beginning at 9:30 a.m. 
on July 4, 2004, and were out of sight by 10:30 a.m.
    Only one animal, a calf, was known to have died following this 
event. The animal was noted alive and alone in the Bay on the afternoon 
of July 4, 2004 and was found dead in the Bay the morning of July 5, 
2004. A full necropsy, magnetic resonance imaging, and computerized 
tomography examination were performed on the calf to determine the 
manner and cause of death. The combination of imaging, necropsy and 
histological analyses found no evidence of infectious, internal 
traumatic, congenital, or toxic factors. Cause of death could not be 
definitively determined, but it is likely that maternal separation, 
poor nutritional condition, and dehydration contributed to the final 
demise of the animal. Although we do not know when the calf was 
separated from its mother, the animals' movement into the Bay and 
subsequent milling and re-grouping may have contributed to the 
separation or lack of nursing, especially if the maternal bond was weak 
or this was 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, 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 the following: 
(1) The evidently anomalous nature of the stranding; (2) its close 
spatiotemporal correlation with wide-scale, sustained use of sonar 
systems previously associated with stranding of deep-diving marine 
mammals; (3) the directed movement of two groups of transmitting 
vessels toward the southeast and southwest coast of Kauai; (4) the 
results of acoustic propagation modeling and an analysis of possible 
animal transit times to the Bay; and (5) the absence of any other 
compelling causative explanation. The initiation and persistence of 
this event may have resulted from an interaction of biological and 
physical factors. The biological factors may have included the presence 
of an apparently uncommon, deep-diving cetacean species (and possibly 
an offshore, non-resident group), social interactions among the animals 
before or after they entered the Bay, and/or unknown predator or prey 
conditions. The physical factors may have included the presence of 
nearby deep water, multiple vessels transiting in a directed manner 
while transmitting active sonar over a sustained period, the presence 
of surface sound ducting conditions, and/or intermittent and random 
human interactions while the animals were in the Bay.
    A separate event involving melon-headed whales and rough-toothed 
dolphins took place over the same period of time in the Northern 
Mariana Islands (Jefferson et al., 2006), which is several thousand 
miles from Hawaii. Some 500 to 700 melon-headed whales came into 
Sasanhaya Bay on July 4, 2004 near the island of Rota and then left of 
their own accord after 5.5 hrs; no known active sonar transmissions 
occurred in the vicinity of that event. The Rota incident led to 
scientific debate regarding what, if any, relationship the event had to 
the simultaneous events in Hawaii and whether they might be related by 
some common factor (e.g., there was a full moon on July 2, 2004 as well 
as during other melon-headed whale strandings and nearshore 
aggregations (Brownell et al., 2009; Lignon et al., 2007; Mobley et 
al., 2007). Brownell et al. (2009) compared the two incidents, along 
with one other stranding incident at Nuka Hiva in French Polynesia and 
normal resting behaviors observed at Palmyra Island, in regard to 
physical features in the areas, melon-headed whale behavior, and lunar 
cycles. Brownell et al., (2009) concluded that the rapid entry of the 
whales into Hanalei Bay, their movement into very shallow water far 
from the 100-m contour, their milling behavior (typical pre-stranding 
behavior), and their reluctance to leave the bay constituted an unusual 
event that was not similar to the events that occurred at Rota (but was 
similar to the events at Palmyra), which appear to be similar to 
observations of melon-headed whales resting normally at Palmyra Island. 
Additionally, there was no correlation between lunar cycle and the 
types of behaviors observed in the Brownell et al. (2009) examples.

Association Between Mass Stranding Events and Exposure to MFAS

    Several authors have noted similarities between some of these 
stranding incidents: they occurred in

[[Page 64539]]

islands or archipelagoes with deep water nearby, several appeared to 
have been associated with acoustic waveguides like surface ducting, and 
the sound fields created by ships transmitting MFAS (Cox et al., 2006, 
D'Spain et al., 2006). Although Cuvier's beaked whales have been the 
most common species involved in these stranding events (81 percent of 
the total number of stranded animals), other beaked whales (including 
Mesoplodon europeaus, M. densirostris, and Hyperoodon ampullatus) 
comprise 14 percent of the total. Other species, 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 make 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 mammal 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 (e.g., 
acoustically mediated bubble growth, as addressed above) prior to 
stranding or whether a behavioral response to sound occurred that 
ultimately caused the beaked whales to be injured and 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 the following: Gas bubble formation 
caused by excessively fast surfacing; remaining at the surface too long 
when tissues are supersaturated with nitrogen; or diving prematurely 
when extended time at the surface is necessary to eliminate excess 
nitrogen. More specifically, beaked whales that occur in deep waters 
that are in close proximity to shallow waters (e.g., 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. Furthermore, beaked whales exposed to 
active sonar might alter their dive behavior. Changes in dive behavior 
might cause them to remain at the surface or at depth for extended 
periods of time which could lead to hypoxia by increasing their oxygen 
demands or increasing their energy expenditures (i.e., the energy 
needed to remain at depth, which would increase their oxygen demand). 
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 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 (e.g., 
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 (up to 2 
kilometers) and long (up to 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 (e.g., causing beaked whales to spend 
more time at surface without the bounce dives that are necessary for 
recovery) 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

[[Page 64540]]

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 three 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 GoA TMAA, NMFS recommends caution when either steep 
bathymetry, surface ducting conditions, 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.

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 depend 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, and 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 densities. Different velocities are 
imparted to tissues of different densities, and this can lead to their 
physical disruption. Blast effects are greatest at the gas-liquid 
interface (Landsberg, 2000). Gas-containing organs, particularly the 
lungs and gastrointestinal tract, are especially susceptible (Goertner, 
1982; Hill, 1978; Yelverton et al., 1973). In addition, gas-containing 
organs including the nasal sacs, larynx, pharynx, trachea, and lungs 
may be damaged by compression/expansion caused by the oscillations of 
the blast gas bubble (Reidenberg and Laitman, 2003). Intestinal walls 
can bruise or rupture, with subsequent hemorrhage and escape of gut 
contents into the body cavity. Less severe gastrointestinal tract 
injuries include contusions, petechiae (small red or purple spots 
caused by bleeding in the skin), and slight hemorrhaging (Yelverton et 
al., 1973).
    Because the ears are the most sensitive to pressure, they are the 
organs most 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 (see Noise-induced 
Threshold Shift Section above; Ketten, 1995). Sound-related trauma can 
be lethal or sublethal. Lethal impacts are those that result in 
immediate death or serious debilitation in or near an intense source 
and are not, technically, pure acoustic trauma (Ketten, 1995). 
Sublethal impacts include hearing loss, which is caused by exposures to 
perceptible sounds. Severe damage (from the shock wave) to the ears 
includes tympanic membrane rupture, fracture of the ossicles, damage to 
the cochlea, hemorrhage, and cerebrospinal fluid leakage into the 
middle ear. Moderate injury implies partial hearing loss due to 
tympanic membrane rupture and blood in the middle ear. Permanent 
hearing loss also can occur when the hair cells are damaged by one very 
loud event, as well as by prolonged exposure to a loud noise or chronic 
exposure to noise. The level of impact from blasts depends on both an 
animal's location and, at outer zones, on its sensitivity to the 
residual noise (Ketten, 1995).
    There have been fewer studies addressing the behavioral effects of 
explosives on marine mammals 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.

[[Page 64541]]

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 a 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 mammal taxonomy groups, Richardson et al. (1995) 
provides the following assessment regarding cetacean reactions to 
vessel traffic:
    Toothed whales: ``In summary, toothed whales sometimes show no 
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 interest (e.g., approaching vessels) to 
generally uninterested reactions; finback whales (B. physalus) changed 
from mostly negative (e.g., 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 reactions that were 
often strongly positive. 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 (e.g., the sperm whale). In addition, 
some baleen whales, such as the North Atlantic right whale, seem 
generally unresponsive to vessel sound, making them more susceptible to 
vessel collisions (Nowacek et al., 2004). These species are primarily 
large, slow moving whales. Smaller marine mammals (e.g., bottlenose 
dolphin) move quickly through the water column and are often seen 
riding the bow wave of large ships. Marine mammal responses to vessels 
may include avoidance and changes in dive pattern (NRC, 2003).
    An examination of all known ship strikes from all shipping sources 
(civilian and military) indicates vessel speed is a principal factor in 
whether a vessel strike results in death (Knowlton and Kraus, 2001; 
Laist et al., 2001; Jensen and Silber, 2003; Vanderlaan and Taggart, 
2007). In assessing records in which vessel speed was known, Laist et 
al. (2001) found a direct relationship between the occurrence of a 
whale strike and the speed of the vessel involved in the collision. The 
authors concluded that most deaths occurred when a vessel was traveling 
in excess of 13 knots.
    Jensen and Silber (2003) detailed 292 records of known or probable 
ship strikes of all large whale species from 1975 to 2002. Of these, 
vessel speed at the time of collision was reported for 58

[[Page 64542]]

cases. Of these cases, 39 (or 67 percent) resulted in serious injury or 
death (19 of those resulted in serious injury as determined by blood in 
the water, propeller gashes or severed tailstock, and fractured skull, 
jaw, vertebrae, hemorrhaging, massive bruising or other injuries noted 
during necropsy and 20 resulted in death). Operating speeds of vessels 
that struck various species of large whales ranged from 2 to 51 knots. 
The majority (79 percent) of these strikes occurred at speeds of 13 
knots or greater. The average speed that resulted in serious injury or 
death was 18.6 knots. Pace and Silber (2005) found that the probability 
of death or serious injury increased rapidly with increasing vessel 
speed. Specifically, the predicted probability of serious injury or 
death increased from 45 percent to 75 percent as vessel speed increased 
from 10 to 14 knots, and exceeded 90 percent at 17 knots. Higher speeds 
during collisions result in greater force of impact, but higher speeds 
also appear to increase the chance of severe injuries or death by 
pulling whales toward the vessel. Computer simulation modeling showed 
that hydrodynamic forces pulling whales toward the vessel hull increase 
with increasing speed (Clyne, 1999; Knowlton et al., 1995).
    The Jensen and Silber (2003) report notes that the database 
represents a minimum number of collisions, because the vast majority 
probably goes undetected or unreported. In contrast, Navy vessels are 
likely to detect any strike that does occur, and they are required to 
report all ship strikes involving marine mammals. Overall, the 
percentages of Navy traffic relative to overall large shipping traffic 
are very small (on the order of 2 percent).
    The probability of vessel and marine mammal interactions occurring 
in the GoA TMAA 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 that may be operating in the GoA TMAA varies 
based on training schedules and can typically range from zero to about 
ten vessels per 21-day exercise cycle. 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 rigid-hulled inflatable 
boats (RHIBs), may also be utilized in the GoA TMAA. 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 to three weeks. These training events are widely 
dispersed; consequently, the density of ships within the GoA TMAA at 
any given time is extremely low (i.e., approximately 0.0002 ships/
nm\2\). Moreover, naval vessels transiting the GoA TMAA 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 GoA TMAA 
training activities have a number of advantages for avoiding ship 
strikes as compared to most commercial merchant vessels, including the 
following: Navy ships have their bridges positioned forward, offering 
good visibility ahead of the bow; crew size is much larger than that of 
merchant ships allowing for more potential observers on the bridge; 
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; Navy lookouts receive extensive 
training including Marine Species Awareness Training designed to 
provide marine species detection cues and information necessary to 
detect marine mammals; and 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 GoA TMAA, 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 GoA TMAA application are 
considered military readiness activities.
    NMFS reviewed the proposed GoA TMAA activities and the proposed GoA 
TMAA 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 GoA, 
and the Navy and NMFS subsequently coordinated and produced the draft 
Stranding Response Plan for the GoA, 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).

[[Page 64543]]

Mitigation Measures Proposed in the Navy's LOA Application

Personnel Training--Watchstanders and Lookouts
    The use of shipboard lookouts is a critical component of all Navy 
mitigation measures. Navy shipboard lookouts (also referred to as 
``watchstanders'') are highly qualified and experienced observers of 
the marine environment. Their duties require that they report all 
objects sighted in the water to the Officer of the Deck (OOD) (e.g., 
trash, a periscope, marine mammals, sea turtles) and all disturbances 
(e.g., surface disturbance, discoloration) that may be indicative of a 
threat to the vessel and its crew. There are personnel serving as 
lookouts on station at all times (day and night) when a ship or 
surfaced submarine is moving through the water.
    All Commanding Officers (COs), Executive Officers (XOs), lookouts, 
OODs, Junior OODs (JOODs), maritime patrol aircraft aircrews, and Anti-
submarine Warfare (ASW) helicopter crews would complete the NMFS-
approved Marine Species Awareness Training (MSAT) by viewing the U.S. 
Navy MSAT digital versatile disk (DVD). MSAT may also be viewed on-line 
at https://portal.navfac.navy.mil/go/msat. MSAT training must be 
reviewed at least annually and again prior to the first use of mid-
frequency active sonar (MFAS) and/or IEER during major ASW exercises. 
This training addresses the lookout's role in environmental protection, 
laws governing the protection of marine species, Navy stewardship 
commitments, and general observation information to aid in avoiding 
interactions with marine species, and must be recorded in the 
individual's training record.
    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).
    Lookout training will include on-the-job instruction under the 
supervision of a qualified, experienced watchstander. 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 lookouts required by a 
particular mitigation measure as long as supervisors monitor their 
progress and performance.
    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.
Operating Procedures and Collision Avoidance (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.
    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.
    While underway, surface vessels will have at least two lookouts 
with binoculars; surfaced submarines would 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 shall watch for and report to the OOD 
the presence of marine mammals.
    All surface ships participating in ASW training events shall have, 
in addition to the three personnel on watch constantly, at least two 
additional personnel on watch as lookouts at all times during the 
exercise.
    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.
    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.
    Personnel on lookout shall employ visual search procedures 
employing a scanning methodology in accordance with the Lookout 
Training Handbook (NAVEDTRA 12968-D).
    After sunset and prior to sunrise, lookouts will employ Night 
Lookout Techniques in accordance with the Lookout Training Handbook 
(NAVEDTRA 12968-D).
    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 OOD, 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. Navy 
environmental compliance relies heavily on the abilities of lookouts to 
detect and avoid protected species. Therefore, it is critical that 
lookouts be vigilant in their reporting.
    While in transit, naval vessels shall be alert at all times, use 
extreme caution, and proceed at a ``safe speed'' so that the vessel 
could take proper and effective action to avoid a collision with any 
marine animal and could be stopped within a short distance appropriate 
to the prevailing circumstances and conditions.
    When marine mammals 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).
    Navy vessels will maneuver to keep at least 1,500 ft (500 yd or 457 
m) away from any observed whale in the vessel's path and avoid 
approaching whales head-on. These requirements do not apply if a 
vessel's safety is threatened, such as when change of course would 
create an imminent and serious threat to a person, vessel, or aircraft, 
and to the extent vessels are restricted in their ability to maneuver. 
Restricted maneuverability includes, but is not limited to, situations 
when vessels are engaged in dredging, submerged activities, launching 
and recovering aircraft or landing craft, minesweeping activities, 
replenishment while underway, and towing activities that severely 
restrict a vessel's ability to deviate course. Vessels will take 
reasonable steps to alert other vessels in the vicinity of the whale. 
Given rapid swimming speeds and maneuverability of many dolphin 
species, naval vessels shall maintain normal course and speed on 
sighting dolphins unless some condition indicated a need for the vessel 
to maneuver.
    Navy aircraft participating in exercises at sea will conduct and 
maintain, when operationally feasible and safe, surveillance for marine 
mammals as long as it does not violate safety constraints or interfere 
with the accomplishment of primary operational duties. Marine mammal 
detections would be immediately reported to the 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

[[Page 64544]]

would likely result in a closing of the distance to the detected marine 
mammal.
    Floating weeds and kelp, algal mats, clusters of seabirds, and 
jellyfish are good indicators of marine mammals. Therefore, where these 
circumstances are present, the Navy will exercise increased vigilance 
in watching for marine mammals.
    All vessels will maintain logs and records documenting training 
operations should they be required for event reconstruction purposes. 
Logs and records are kept and archived following completion of a major 
training exercise.

Operating Procedures (for Mid-Frequency Active Sonar Activities)

    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.
    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.
    Aircraft with deployed sonobuoys will use only the passive 
capability of sonobuoys when marine mammals are detected within 200 yd 
(183 m) of the sonobuoy.
    Helicopters shall observe/survey the vicinity of an ASW exercise 
for 10 minutes before the first deployment of active (dipping) sonar in 
the water.
    Helicopters shall not dip their sonar within 200 yd (183 m) of a 
marine mammal and shall cease pinging if a marine mammal closes within 
200 yd (183 m) after pinging has begun.
    Safety Zones--When marine mammals are detected by any means 
(aircraft, shipboard lookout, or acoustically) the Navy shall ensure 
that sonar transmission levels are limited to at least 6 dB below 
normal operating levels if any detected marine mammals are within 1,000 
yd (914 m) of the sonar dome (the bow) (i.e., limit to at most 229 dB 
for AN/SQS-53 and 219 dB for AN/SQS-56, etc.). Ships and submarines 
shall continue to limit maximum transmission levels by this 6-dB factor 
until the animal has been seen to leave the 1,000-yd safety zone, has 
not been detected for 30 minutes, or the vessel has transited more than 
2,000 yd (1829 m) beyond the location of the last detection.
    When marine mammals are detected by any means (aircraft, shipboard 
lookout, or acoustically) the Navy shall ensure that sonar transmission 
levels are limited to at least 10 dB below normal operating levels if 
any detected marine mammals are within 500 yd (457 m) of the sonar dome 
(the bow). 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 safety zone, has not been detected for 30 minutes, or the vessel 
has transited more than 2,000 yd (1,829 m) beyond the location of the 
last detection.
    When marine mammals are detected by any means (aircraft, shipboard 
lookout, or acoustically) the Navy shall ensure that sonar transmission 
ceases if any detected marine mammals are within 200 yd (183 m) of the 
sonar dome (the bow). Sonar shall not resume until the animal has been 
seen to leave the 200-yd safety zone, has not been detected for 30 
minutes, or the vessel has transited more than 2,000 yd (457 m) beyond 
the location of the last detection.
    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.
    Prior to start up or restart of active sonar, operators will check 
that the 1,000-m safety zone radius around the sound source is clear of 
marine mammals.
    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.
    Submarine sonar operators will review detection indicators of 
close-aboard marine mammals prior to the commencement of ASW training 
events involving MFAS.
    If the need for power-down should arise when the Navy is 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).

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

    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.
    A 600 yd (585 m) radius buffer zone will be established around the 
intended target.
    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.
    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)

    A 200-yd (183 m) radius buffer zone shall be established around the 
intended target.
    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.
    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.
    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.

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

    Vessels will orient the geometry of gunnery exercises in order to 
prevent debris from falling in the area of sighted marine mammals.
    Vessels will attempt to recover any parachute deploying aerial 
targets to the extent practicable (and their parachutes if feasible) to 
reduce the potential for entanglement of marine mammals.
    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.

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

    A 200-yd (183 m) radius buffer zone will be established around the 
intended target.
    If surface vessels are involved, the lookouts would visually survey 
the

[[Page 64545]]

buffer zone for marine mammals prior to and during the exercise.
    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.
    The exercise will be conducted only if marine mammals are not 
visible within the buffer zone.

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

    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.
    A 1,000 yd (914 m) radius buffer zone shall be established around 
the intended target.
    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 it has visual site of the target area at a maximum 
height of 1,500 ft (457 m). 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.
    The exercises will be conducted only if marine mammals 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 ft 
(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.

Sinking Exercises (SINKEX)

    The selection of sites suitable for SINKEX involves a balance of 
operational suitability and requirements established under the Marine 
Protection, Research, and Sanctuaries Act (MPRSA) permit granted to the 
Navy (40 CFR Sec.  229.2). To meet operational suitability criteria, 
SINKEX locations 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 1,000 fathoms (6,000 ft (1828 m)) deep and at least 50 nm (92.6 
km) from land, which may incidentally avoid adverse impacts to marine 
mammals. In general, most marine mammals 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.
    In addition, the Magnuson-Stevens Fisheries Conservation and 
Management Act (16 U.S.C. 1801 et seq.), as amended by the Sustainable 
Fisheries Act (SFA), mandated identification and conservation of 
Essential Fish Habitat (EFH) as well as subset of EFH known as Habitat 
Areas of Particular Concern (HAPC). The guidelines for designating EFH 
identify HAPCs as types or areas of habitat within EFH that are defined 
based on one or more of the following considerations: The importance of 
the ecological function provided by the habitat; the extent to which 
the habitat is sensitive to human-induced environmental degradation; 
whether, and to what extent, development activities are or will be 
stressing the habitat type; and the rarity of the habitat type (50 CFR 
600.815(a)(8)). The following HAPCs have been established in the GoA: 
10 Gulf of Alaska Slope Habitat Conservation Areas (GOASHCAs), 15 
Alaska Seamount Habitat Protection Areas (ASHPAs); and 5 Gulf of Alaska 
Coral Habitat Protection Areas (NMFS 2006). Within the TMAA, one 
GOASHCA (Cable) and three ASHPAs (Dall, Giacomini, and Quinn Seamounts) 
occur almost entirely within the TMAA. Other areas, such as the Kodiak 
Seamount and Middleton West GOASHCA are partially located in the TMAA. 
The Navy has agreed not to conduct SINKEXs--the activity with the 
greatest potential to impact HAPCs--within these areas.
    The following mitigation measures shall be applied when conducting 
a SINKEX in the GoA TMAA:
    All weapons firing shall be conducted during the period 1 hour 
after official sunrise to 30 minutes before official sunset.
    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), shall be surveyed. 
Together, the zone extends out 2 nm (3.7 km) from the target.
    A series of surveillance over-flights shall be conducted within the 
2 nm (3.7 km) zone around the target, prior to and during the exercise, 
when feasible. Survey protocol shall be as follows:
    Overflights within the 2 nm (3.7 km) zone around the target 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.
    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.
    In addition to the overflights, the 2-nm (3.7 km) zone around the 
target shall be monitored by passive acoustic means, when assets are 
available. This passive acoustic monitoring will 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.
    On each day of the exercise, aerial surveillance of the 2 nm (3.7 
km) zone around the target shall commence 2 hours prior to the first 
firing.
    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 this 2 nm (3.7 km)

[[Page 64546]]

zone around the target is free of marine mammals.
    If a marine mammal is observed within the 2 nm (3.7 km) zone around 
the target, firing will be delayed until the animal is re-sighted 
outside the 2 nm (3.7 km) zone around the target, or 30 minutes have 
elapsed. After 30 minutes, if the animal has not been re-sighted it can 
be assumed to have left the 2 nm (3.7 km) zone around the target. The 
OCE will determine if the marine mammal is in danger of being adversely 
affected by commencement of the exercise.
    During breaks in the exercise of 30 minutes or more, the 2 nm (3.7 
km) zone around the target shall again be surveyed for any marine 
mammal. If marine mammals are sighted within the 2 nm (3.7 km) zone 
around the target, the OCE shall be notified, and the procedure 
described above shall be followed.
    Upon sinking of the vessel, a final surveillance of the 2 nm (3.7 
km) zone around the target shall be monitored for 2 hours, or until 
sunset, to verify that no marine mammals were harmed.
    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.
    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 2 nm (3.7 km) zone around the target. This shall be 
accomplished through the use of an additional aircraft, if available, 
and conducting tight search patterns.
    The exercise shall not be conducted unless the 2 nm (3.7 km) zone 
around the target 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.
    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 
Stranding Plan for detail).
    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.

Explosive Source Sonobuoys (SSQ-110A)

    AN/SSQ-110A Pattern Deployment--The following mitigation measures 
shall be used with the employment of IEER/AEER sonobuoys:
    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 500 yd (457 m) at a slow speed, if operationally 
feasible and weather conditions permit. In dual aircraft operations, 
crews are allowed to conduct coordinated area clearances.
    For IEER (AN/SSQ-110A), 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.
    For any part of the intended sonobuoy pattern where a post (source/
receiver sonobuoy pair) will be deployed within 1,000 yd (914 m) of 
observed marine mammal activity, the Navy shall deploy the receiver 
only (i.e., not the source) and monitor while conducting a visual 
search. When marine mammals are no longer detected within 1,000 yd (914 
m) of the intended post position, the source sonobuoy (AN/SSQ-110A/SSQ-
125) will be co-located with the receiver.
    When operationally feasible, Navy crews shall conduct continuous 
visual and aural monitoring of marine mammal activity. This shall 
include monitoring of own-aircraft sensors from the time of the first 
sensor placement until the aircraft have left the area and are out of 
RF range of these sensors.
AN/SSQ-110A Pattern Employment
    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.
    Visual Detection--If marine mammals are visually detected within 
1,000 yd (914 m) of the explosive source sonobuoy (AN/SSQ-110A/SSQ-125) 
intended for use, then that payload shall not be activated. 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 1,000 yd (914 
m) safety buffer. Aircrews may shift their multi-static active search 
to another post, where marine mammals are outside the 1,000 yd (914 m) 
safety buffer.
AN/SSQ-110A Scuttling Sonobuoys
    For IEER (AN/SSQ-110A), 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 shall ensure that a 1,000 yd 
(914 m) safety buffer, visually clear of marine mammals, is maintained 
around each post as is done during active search operations.
    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.
    The Navy 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.
    Mammal monitoring shall continue until out of own-aircraft sensor 
range.

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: The 
manner in which, and the degree to which, the successful implementation 
of the measure is expected to minimize adverse impacts to marine 
mammals; the proven or likely efficacy of the

[[Page 64547]]

specific measure to minimize adverse impacts as planned; and 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, 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 
would effect the least practicable adverse impact on the affected 
species or stocks and their habitat, NMFS will consider all public 
comments to help inform our final decision. Consequently, the proposed 
mitigation measures may be refined, modified, removed, or added to 
prior to the issuance of the final rule based on public comments 
received, and where appropriate, further analysis of any additional 
mitigation measures.
    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 would 
ensure power-down of MFAS/HFAS by 6 dB when a marine mammal is detected 
within 1,000 yd (914 m), power-down of 4 more dB (or 10 dB total) when 
a marine mammal is detected within 500 yd (457 m), and would cease 
MFAS/HFAS transmissions when a marine mammal is detected within 200 yd 
(183 m).
    PTS/Injury--NMFS believes that the proposed mitigation measures 
would allow the Navy to avoid exposing marine mammals to received 
levels of MFAS/HFAS sound that would result in injury for the following 
reasons: 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 33 ft (10 m); and 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.
    TTS--NMFS believes that the proposed mitigation measures would 
allow the Navy to minimize exposure of marine mammals to received 
levels of MFAS/HFAS sound associated with TTS for the following 
reasons: The estimated maximum distance from the most powerful source 
at which cetaceans would receive levels at or above the threshold for 
TTS is approximately 584 ft (178 m) from the source in most operating 
environments; based on the size of the animals, average group size, 
behavior, and average dive time, NMFS believes that the probability 
that Navy watchstanders would visually detect marine mammals at some 
point within the 1,000 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 shut down or power-down to avoid exposing these 
species to sound levels associated with TTS; more cryptic animals that 
are difficult to detect and observe, such as deep-diving cetaceans 
(i.e., beaked whales), 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 
1-hr subsurface dive by a beaked whale, the ship would have moved over 
5 to 10 nm from the original location; and, 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

[[Page 64548]]

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 the Navy to avoid exposing marine mammals to underwater 
detonations that would result in injury or mortality for the following 
reasons: 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). Animals would need to be less than 
611 m (688 yd) (large explosives) or 19 m (20.7 yd) (smaller charges) 
from the source to be injured. 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. The model 
predicted that four animals (three Dall's porpoises and one Northern 
fur seal) would be exposed to explosive levels associated with injury 
or death. 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: Seventy 
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. However, more 
cryptic, deep-diving species (e.g., beaked whales) are less likely to 
be visually detected and could potentially be exposed to explosive 
levels expected to cause TTS. The model estimated that two beaked 
whales would be exposed to TTS levels. 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 Fiscal Year 08 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 percent of all U.S. research concerning the effects of 
human-generated sound on marine mammals and 50 percent of such research 
conducted worldwide. Major topics of Navy-supported 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
    <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 Assessment. 
Furthermore, research cruises by NMFS and by academic institutions have 
received funding from the U.S. Navy. For example, in April 2009, the 
U.S. Pacific Fleet contributed approximately $250,000 to support a NMFS 
marine mammal density survey of the GoA's offshore waters. The goal of 
this validation monitoring was to increase the state of awareness on 
marine mammal occurrence, density, and distribution within the GoA. The 
Navy funded vessel-based line-transect survey conducted from onboard 
the NOAA ship Oscar Dyson determined marine mammal species distribution 
and abundance in the GoA TMAA. The survey cruise employed multiple 
observation techniques, including visual and passive acoustic 
observations, as well as photographic identifications (Rone et al., 
2009). In addition to the U.S. Pacific Fleet-funded monitoring 
initiative, the Chief of Naval Operations Environmental Readiness 
Division and the Office of Naval Research have developed a coordinated 
Science & Technology and Research & Development program focused on 
marine mammals and sound. Total Investment in this program between 2004 
and 2008 was $100 million. Fiscal Year 09 funding was $22 million and 
continued funding at levels greater than $14 million is foreseen in 
subsequent years (beyond 2010).
    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,

[[Page 64549]]

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.

Monitoring

    Section 101(a)(5)(A) of the MMPA states that in order to issue an 
ITA for an activity, NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such taking''. The MMPA implementing 
regulations at 50 CFR 216.104(a)(13) indicate that requests for LOAs 
must include the suggested means of accomplishing the necessary 
monitoring and reporting that will result in increased knowledge of the 
species and of the level of taking or impacts on populations of marine 
mammals that are expected to be present.
    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 increase in 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 GoA TMAA

    The Navy submitted a draft Monitoring Plan for the GoA TMAA 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.
    Navy Monitoring Plans are typically designed as a collection of 
focused ``studies'' to gather data that will allow the Navy to address 
one or more of the following questions:
    (a) Are marine mammals exposed to MFAS/HFAS (1-10 kHz), 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, 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 and 
explosives (e.g., Protective Measures Assessment Protocol, major 
exercise measures agreed to by the Navy through permitting) effective 
at avoiding TTS, injury, and mortality of marine mammals?
    Given the larger scope of training events within other Navy range 
complexes as compared to the GoA, not all of these original five study 
questions would necessarily be addressed within the GoA TMAA Monitoring 
Plan. Rather, data collected from the GoA monitoring efforts would be 
used to supplement a consolidated range complex marine mammal 
monitoring report incorporating data from the Hawaii Range Complex, 
Marianas Island Range Complex, Northwest Training Range Complex, and 
Southern California Range Complex.
    Data gathered in these studies will be collected by qualified, 
professional marine mammal biologists that are experts in their field.
    Monitoring methods proposed for the GoA include use of passive 
acoustic monitoring (PAM) to primarily focus on providing additional 
data or study questions (b) and (c).
    This monitoring plan has been designed to gather data on all 
species of marine mammals that are observed in the GoA TMAA study area; 
however, the Navy will prioritize monitoring efforts for ESA-listed 
species and beaked whale species. The Plan recognizes that deep-diving 
and cryptic species of marine mammals, such as beaked whales and sperm 
whales, may have low probability of visual detection (Barlow and 
Gisiner, 2006). Therefore, methods will be utilized to address this 
issue (e.g., PAM).
    During the comment period on the Notice of Receipt (75 FR 5575, 
February 3, 2010) for the GoA TMAA action, NMFS received multiple 
public comments suggesting that there are inadequate density, 
distribution, and abundance data for marine mammals in the GoA TMAA. As 
mentioned previously, the Navy funded a $250,000 density survey in the 
off-shore waters of the GoA TMAA in April, 2009. As noted above, the 
Navy's draft monitoring plan was developed specifically to address 
distribution and abundance of marine mammals, and the year-round PAM 
recorders may fill in some of the seasonal data-gaps. NMFS believes 
that we should vigorously target this baseline information need with 
the monitoring plan and we will continue to work with the Navy on the 
draft plan, and in consideration of the public comments that we receive 
on this proposed rule. During the public comment period, we encourage 
the public to recommend the most effective regionally specific methods 
for gathering the needed marine mammal density, distribution, and 
abundance information and to prioritize the specific data needs 
(species, time of year, etc.). This information will ensure the design 
of the most effective Monitoring Plan with the resources available.
    In addition to the Monitoring Plan for the GoA, the Navy has 
established an Integrated Comprehensive Monitoring Program (ICMP). The 
ICMP is a Navy-wide monitoring framework that will provide an 
overarching structure and coordination that will, over time, compile 
data from all Navy range-specific monitoring plans; the GoA TMAA plan 
is just one component of the ICMP. The overall objective of the

[[Page 64550]]

ICMP is to assimilate relevant data collected across Navy range 
complexes in order to answer questions pertaining to the impact of MFAS 
and underwater explosive detonations on marine animals. Top priorities 
of the ICMP include: Monitor Navy training events, particularly those 
involving MFAS and underwater detonations; collect data to support 
estimating the number of individuals exposed to sound levels above 
current regulatory thresholds; assess the efficacy and practicability 
of monitoring and mitigation tools and techniques and the Navy's 
current mitigation methods; and add to the overall knowledge base on 
potential behavioral and physiological effects to marine species from 
MFAS and underwater detonations. More information about the ICMP may be 
found in the draft Monitoring Plan for the GoA.

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 other Navy rules 
and LOAs (e.g., the Southern California Range Complex (SOCAL), Hawaii 
Range Complex (HRC), etc.). The Monitoring Workshop participants will 
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 will 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 will be applied to monitoring plans as appropriate.

Adaptive Management

    The final regulations governing the take of marine mammals 
incidental to Navy training exercises in the GoA TMAA will contain an 
adaptive management component. Our understanding of the effects of MFAS 
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 in the Pacific 
Ocean). 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 or biennial 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 or biennial LOAs.
    The following are some of the possible sources of applicable data: 
(1) Findings of the Workshop that the Navy will convene in 2011 to 
analyze monitoring results to date, review current science, and 
recommend modifications, as appropriate, to the monitoring protocols to 
increase monitoring effectiveness; (2) compiled results of Navy funded 
research and development (R&D) studies (presented pursuant to the ICMP, 
which is discussed elsewhere in this document); (3) results from 
specific stranding investigations (involving coincident MFAS or 
explosives training or not involving coincident use); (4) results from 
general marine mammal and sound research; and (5) any information which 
reveals that marine mammals may have been taken in a manner, extent or 
number not authorized by these regulations or subsequent Letters of 
Authorization.
    Separately, in July 2010, NMFS and the Navy convened the ``Marine 
Mammals and Sound'' workshop, which brought together science and policy 
experts from the government, the academic community, and non-
governmental organizations with the goals of prioritizing marine mammal 
research needs and opening up a broad discussion of (and potentially 
making recommendations regarding) some of the current management issues 
related to marine mammals and sound. After the information and ideas 
gathered during this workshop are sorted, compiled, and assessed, NMFS 
will use them, as appropriate, to inform our management decisions on 
issues such as appropriate mitigation and monitoring. In addition to 
considering these workshop products in the broader context of all MMPA 
authorizations that the Office of Protected Resources, they will also 
be considered as NMFS and the Navy work through the Adaptive Management 
process outlined for the GOA below.
    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 LOAs. NMFS and the Navy will meet, 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 GoA TMAA 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.

[[Page 64551]]

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 the 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; and
    <bullet> Provide NMFS a photo or video, if equipment is available.

Annual GoA TMAA Monitoring Plan Report

    The Navy shall submit a report annually on December 15 describing 
the implementation and results (April through October of the same year) 
of the GoA TMAA 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 GoA TMAA 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 GoA TMAA Exercise Report referenced below.
    The GoA TMAA Monitoring Plan Report may be provided to NMFS within 
a larger report that includes the required Monitoring Plan Reports from 
multiple Range Complexes.

Annual GoA TMAA Exercise Report

    The Navy will submit an Annual GoA TMAA Report on December 15 of 
every year (covering data gathered from April through October). This 
report shall contain the subsections and information indicated below.
MFAS/HFAS Training Exercises
    This section shall contain the following information for the 
following Coordinated and Strike Group exercises: Joint Multi-strike 
Group Exercises; Joint Expeditionary Exercises; and Marine Air Ground 
Task Force TMAA:
    (a) Exercise Information (for each exercise)
    (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 an 
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 exercise)
    (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
    (x) Sonar source in use (y/n)
    (xi) Indication of whether animal is <200 yd, 200-500 yd, 500-1,000 
yd, 1,000-2,000 yd, or >2,000 yd 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 
exercises) of the effectiveness of mitigation measures designed to 
avoid exposing marine mammals to MFAS, that 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 the GoA TMAA. The Navy shall include (in the GoA TMAA 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 GoA TMAA 
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

[[Page 64552]]

    (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 (762 m for SINKEX in the GoA TMAA); 
(2) the required exclusion zone (1 nm for SINKEX in the GoA TMAA); (3) 
the required observation distance (if different than the exclusion zone 
(2 nm for SINKEX in the GoA TMAA); and (4) greater than the required 
observed distance. For example, in this case, the observer would 
indicate if <762 m, from 762 m to 1 nm, from 1 nm to 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 propsed 
rule) conducted in the GoA TMAA
    (b) Total annual expended/detonated rounds (missiles, bombs, etc.) 
for each explosive type

GoA TMAA 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 GoA TMAA Exercise Reports and GoA TMAA Monitoring Plan 
Reports). This report shall be submitted at the end of the fourth year 
of the rule (December 2014), covering activities that have occurred 
through October 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 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 GoA TMAA Comprehensive Report, the 
Comprehensive National ASW report, the Annual GoA TMAA Exercise Report, 
or the Annual GoA TMAA 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. The 
Potential Effects section 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. This section 
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 GoA.
    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

[[Page 64553]]

such behavioral patterns are abandoned or significantly altered [Level 
B Harassment].
Level B Harassment
    Of the potential effects that were described in the previous 
sections, 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 
previous sections 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 category. 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 was in the same 
frequency band as the necessary vocalizations and of a severity that 
impeded communication.
    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) indicates 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 previous 
sections, 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 (e.g., emboli). 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

[[Page 64554]]

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 an 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--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 the GoA.

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 five bottlenose dolphins and two 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 (exposure level (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

[[Page 64555]]

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 19-33 dB from behavioral measurements and 40-45 dB 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 were 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 (e.g., 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 (<6 dB) 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 GoA 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 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) and onset-PTS 
(40 dB). Therefore, an animal would require approximately 20 dB 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 GoA LOA application. Southall et al. 
(2007) recommend a precautionary dual criteria for TTS (230 dB re 1 
[micro]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) 
does not exist. However, based on the number of years (more than 60) 
and number of hours of MFAS per year that the U.S. (and other 
countries) has operated compared to the reported (and verified) cases 
of associated marine mammal strandings, NMFS believes that the 
probability of these types of injuries is very low.

Level B Harassment Risk Function (Behavioral Harassment)

    In 2006, NMFS issued the first MMPA authorization to allow the take 
of marine mammals incidental to MFAS (to the Navy for RIMPAC). For that 
authorization, NMFS used 173 dB SEL as the criterion for the onset of 
behavioral harassment (Level B Harassment). This type of single number 
criterion is referred to as a step function, in which (in this example) 
all animals estimated to be exposed to received levels above 173 db SEL 
would be predicted to be taken by Level B Harassment and all animals 
exposed to less than 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 three 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

[[Page 64556]]

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] TP19OC10.011

Where:

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

    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 percent 
risk, or the received level at which we believe 50 percent of the 
animals exposed to the designated received level would respond in a 
manner that NMFS classifies as Level B Harassment. The K parameter (K = 
45 dB) is based on three datasets 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 (Cox et al., 2006; 
Southall et al., 2007). The Navy is contributing to an ongoing three-
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 preliminary results from Phase 2 became 
available in October 2008. 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 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 the GoA.
    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 captive marine mammals trained to 
perform tasks on command, 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.
    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.
    Finneran et al. (2001, 2003, 2005) conducted two 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

[[Page 64557]]

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-sec intense tones exhibited short-
term changes in behavior above received sound levels of 178 to 193 dB 
re 1 [micro]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-min signals played 
sequentially three times over. The three signals had a 60 percent 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 [micro]Pa significantly altered their regular behavior and 
did so in identical fashion. Each of these five whales did the 
following: (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 1.1 yd (1 m) 
of the surface.
    3. Odontocete Field Data (Haro Strait--U.S. Ship (USS) SHOUP)--In 
May 2003, killer whales (Orcinus orca) were observed exhibiting 
behavioral responses generally described as avoidance behavior while 
the 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 the 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 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 animals upon actual exposure to AN/SQS-53 sonar.
    The U.S. Department of Commerce (NMFS, 2005a), U.S. Department of 
the Navy (2004b), and 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 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 five 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 percent 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 (DoN, 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 NMFS, 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.

[[Page 64558]]

[GRAPHIC] [TIFF OMITTED] TP19OC10.012

[GRAPHIC] [TIFF OMITTED] TP19OC10.013

    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 
percent, and Navy/NMFS applies that by estimating that 50 percent 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 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

[[Page 64559]]

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 GoA TMAA example, animals exposed to received levels 
between 120 and 130 dB will likely be 76 to 105 km away from a sound 
source; 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 responses 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 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 GoA TMAA, the LOA application, and in the Navy's CHURCHILL FEIS 
(DoN, 2001c).
[GRAPHIC] [TIFF OMITTED] TP19OC10.014

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.

[[Page 64560]]

More information regarding the models used, the assumptions used in the 
models, and the process of estimating take is available in either 
Appendix B of the Navy's Application or Appendix D of the Navy's DEIS.
    (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 up to 20 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 surface 
roughness, as determined by wind speed
    <bullet> The estimated density of each marine mammal species in the 
GoA TMAA (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 GoA TMAA, 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 hrs
    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 percent. NMFS estimates that a 
10-percent increase in active sonar hours would result in approximately 
a 10-percent 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 of quantitative data, NMFS has, and will 
continue, to evaluate that sort of information qualitatively.
BILLING CODE 3510-22-P

[[Page 64561]]

[GRAPHIC] [TIFF OMITTED] TP19OC10.015

BILLING CODE 3510-22-C

[[Page 64562]]

Mortality

    Evidence from five beaked whale strandings, all of which have taken 
place outside the GoA TMAA, 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 five of these physical factors believed to have 
contributed to the likelihood of beaked whale strandings are present, 
in their aggregate, in the GoA TMA, 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 NMFS proposes to authorize take by 
injury or mortality of up to 15 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 GoA TMAA.

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 GoA 
TMAA 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 GoA TMAA 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 GoA TMAA 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, 1992b; 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

[[Page 64563]]

(Budelmann, 1992b). Packard et al. (1990) reported sensitivity to sound 
vibrations between 1 and 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 aggregations of zooplankton, 
krill, and small schooling fish, while toothed whales feed on 
epipelagic, mesopelagic, and bathypelagic fish and squid. As summarized 
above and in the GoA TMAA DEIS in more detail, potential impacts to 
marine mammal food resources within the GoA TMAA are 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 GoA 
TMAA.

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 GoA TMAA DEIS.
    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 GoA 
TMAA. 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 GoA 
TMAA 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 EMATTs.
    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 and a much 
greater amount of Navy training. Therefore, as discussed in the GoA 
TMAA DEIS, expendable material is highly unlikely to directly affect 
marine mammal species or potential habitat within the GoA TMAA.
    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 GoA TMAA DEIS analyzed the potential effects to water quality 
from sonobuoy, Acoustic Device Countermeasures (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,

[[Page 64564]]

nitrogen gas, ammonia, hydrogen cyanide, and nitrogen oxides. All of 
the byproducts, with the exception of 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 (e.g., 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 percent. 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 GoA TMAA.

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 qualifies 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-53 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.

    Table 9--Approximate Percent of Estimated Takes That Occur in the
      Indicated 10-dB Bins for AN/SQS-53 (The Most Powerful Source)
------------------------------------------------------------------------
                                                            Percent of
                                                               total
                                                            harassment
                                      Distance at which        takes
       Received level (SPL)          levels occur in GOA   estimated to
                                            TMAA             occur at
                                                             indicated
                                                               level
------------------------------------------------------------------------
Below 138 dB......................  42 km-105 km........              ~0
138 < Level < 144 dB..............  28 km-42 km.........             < 1
144 < Level < 150 dB..............  17 km-28 km.........              ~1
150 < Level < 156 dB..............  9 km-17 km..........               7
156 < Level < 162 dB..............  5 km-9 km...........              18
162 < Level < 168 dB..............  2.5 km-5 km.........              26
168 < Level < 174 dB..............  1.2 km-2.5 km.......              22
174 < Level < 180 dB..............  0.5 km-1.2 km.......              14
180 < Level < 186 dB..............  335 m-0.5 km........               6
186 < Level < TTS.................  178 m-335 m.........               5
TTS (195 SEL).....................  10 m-178 m..........             < 1

[[Page 64565]]

 
PTS (215 SEL).....................  10 m................           < .01
------------------------------------------------------------------------
Note: For smaller sources, a higher % of the takes occur at lower
  levels, and a lower % at higher levels.

    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 GoA TMAA will respond to MFAS/HFAS. The Navy has 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 indicate no behavioral disturbance was observed. One cannot 
conclude from these results that marine mammals were not harassed from 
MFAS/HFAS, as a portion of animals within the area of concern were not 
seen (especially those more cryptic, deep-diving species, such as 
beaked whales or Kogia spp.) 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; preliminary 2008 
results are also available). Separately, the Navy and NMFS conducted an 
opportunistic tagging experiment with several species of marine mammals 
in the area of the 2008 RIMPAC training exercises in the Hawaii Range 
Complex (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 hrs or be repeated in 
subsequent days. 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 hrs). 
Although explosive exercises may sometimes be conducted in the same 
general areas repeatedly, because of their short duration and the fact 
that they are in the open ocean and animals can easily move away, it is 
similarly unlikely that animals would be exposed for long, continuous 
amounts of time. Although SINKEXs may last for up to 48 hrs, only two 
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 
exposed to the exercise for extended periods or on consecutive days.

TTS

    NMFS and the Navy have estimated that approximately 1,000 
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 9 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:
    (1) Frequency--Available data (of mid-frequency hearing specialists 
exposed to mid- or high-frequency sounds; Southall et al., 2007) 
suggest that most TTS occurs in the frequency range of the source up to 
one octave higher than the source (with the maximum TTS at \1/2\ octave 
above). The more 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

[[Page 64566]]

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 available for each species.
    (2) Degree of the shift (i.e., how many dB is the sensitivity of 
the hearing reduced by)--Generally, both the degree of TTS and the 
duration of TTS will be greater if the marine mammal is exposed to a 
higher level of energy (which would occur when the peak dB level is 
higher or the duration is longer). The threshold for the onset of TTS 
(> 6 dB) is 195 dB (SEL), which might be received at distances of up to 
459 ft (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 
the GoA TMAA). 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).
    (3) Duration of TTS (recovery time)--In the TTS laboratory studies, 
some using exposures of almost an hour in duration or up to 217 SEL, 
almost all individuals recovered within 1 day (or less, often in 
minutes), though in one study (Finneran et al., 2007), recovery took 4 
days.
    Based on the range of degree and duration of TTS reportedly induced 
by exposures to non-pulse sounds of energy higher than that to which 
free-swimming marine mammals in the field are likely to be exposed 
during MFAS/HFAS training exercises in the GoA TMAA, 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 (see Communication Impairment 
Section), though these compensations may incur energetic costs.

Acoustic Masking or Communication Impairment

    Table 5a and Table 5b are 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 tens 
of microseconds. For hull-mounted active sonar, though some of the 
vocalizations that marine mammals make are less than one second long, 
there is only a 1 in 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 Dall's porpoise 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), or 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. 
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-m (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 the Navy's modeling predicts that one Dall's porpoise will 
incur PTS from exposure to MFAS/HFAS, the Navy and NMFS believe it is 
very unlikely to occur; therefore, the Navy has not requested 
authorization to take one by Level A Harasssment and NMFS is not 
proposing to authorize take of Dall's porpoise by Level A harassment.
    As discussed previously, marine mammals (especially beaked whales) 
could potentially respond to MFAS at a

[[Page 64567]]

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 GoA TMAA, which only has a 
strong surface duct present during the winter, and 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. Lastly, an active sonar shutdown protocol 
for strandings involving live animals milling in the water minimizes 
the chances that these types of events turn into mortalities. 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 proposes to authorize the injury or 
mortality of up to 15 beaked whales over the course of the 5-yr 
regulations.

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 one exposure of a blue whale to 
MFAS/HFAS at levels likely to result in Level B harassment will occur, 
and that one exposure 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; zero TTS takes 
are estimated. It is unlikely that any blue whales will incur TTS 
because of the following: 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 of two or three, 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 been seen in the GoA and the Eastern North Pacific 
population is estimated at a minimum of 1,368 whales. Like most baleen 
whales, blue whales would most likely feed in the north during summer 
months (potentially the GoA) and head southward 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 GoA TMAA 
activities are not expected to occur in an area/time of specific 
importance for breeding, calving, 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 
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 11,019 exposures of fin whales to 
MFAS/HFAS at sound levels likely to result in Level B harassment will 
occur, and that 18 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 26 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.
    Although reliable estimates of current abundance for the entire 
Northeast Pacific fin whale stock are not currently available, fin 
whales have been seen in the GoA and the provisional estimate for this 
stock is 3,368 whales for the central-eastern Bering Sea and 683 for 
the eastern Bering Sea. These estimates are considered provisional 
because they have not been corrected for animals missed on the 
trackline, animals submerged when the survey ship passed, and 
responsive movements. For purposes of acoustic impact modeling, a 
density of 0.010 individuals per km\2\ was used based on 24 visual 
observations of fin whale groups totaling 64 individuals during a 10-
day period (Rone et al., 2009). Although acoustic impact modeling 
predicted a large number of takes relative to population size, NMFS 
believes that this is a conservative estimate due to the high number of 
fin whales sighted during the most recent survey in 2009. In addition, 
the majority of fin whale takes by Level B harassment would

[[Page 64568]]

result in behavioral harassment (99.8 percent), which NMFS, for reasons 
discussed in the Behavioral Harassment section above, expects will have 
a negligible impact on the species. For instance, previous monitoring 
reports submitted by the Navy from more than 60 major exercises have 
indicated no observed behavioral disturbance Although one cannot 
conclude from these results that marine mammals were not harassed and 
some of the non-biologist watchstanders might not be well qualified to 
characterize behavior, one can say that the animals observed did not 
respond in any of the obviously more severe ways, such as panic, 
aggression, or anti-predator response that would be more likely to 
adversely affect annual rates of recruitment or survival. Additional 
reasons in support of NMFS' preliminary negligible impact determination 
follow. In the North Pacific, fin whales migrate seasonally from high 
Arctic feeding areas in the summer to low latitude breeding and calving 
areas in the winter. The GoA TMAA activities are not expected to occur 
in an area/time of specific importance for breeding, calving, 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 4 exposures of sei whales to MFAS/
HFAS at sound levels likely to result in Level B harassment will occur, 
and that 4 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; no TTS takes are estimated. 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 (three), 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 GoA TMAA activities are not 
expected to occur in an area/time of specific importance for breeding, 
calving, 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 1,394 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 six TTS takes are also estimated. However, it is 
unlikely that any humpback whales will incur TTS because of the 
following: The distance within which they would have to approach the 
MFAS source (approximately 459 ft (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 one humpback whale 
would be exposed to levels of pressure and/or energy from explosive 
detonations that would result in Level B 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, before or during exercise 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 (Calambokidis et al., 2008). 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 GoA TMAA activities are not expected to occur in an 
area/time of specific importance for breeding, calving, 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 effects of the takes, NMFS has 
preliminarily determined that the Navy's specified activities will have 
a negligible impact on this species.
North Pacific Right Whale (MMPA Depleted/ESA-Listed)
    Acoustic analysis predicts that one exposure of a North Pacific 
right whale to MFAS/HFAS at sound levels likely to result in Level B 
harassment will occur, and that one exposure to explosives will occur. 
These Level B takes are anticipated to be in the form of behavioral 
disturbance as described in the Definition of Harassment: Level B 
Harassment section; no TTS takes are estimated. It is unlikely that any 
North Pacific right whales will incur TTS because of: The distance 
within which they would have to approach the MFAS source (approximately 
459 ft (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

[[Page 64569]]

their large size, callosities on the head, and pronounced v-shaped 
blow) and implement active sonar powerdown or shutdown.
    North Pacific right whales are found in subpolar to temperate 
waters. There are no reliable estimates of current abundance or trends 
for right whales in the North Pacific and the population may only 
number in the low hundreds (Angliss and Allen, 2008). The population in 
the eastern North Pacific is considered to be very small, perhaps only 
in the tens of animals. Over the past 40 years, most sightings in the 
eastern North Pacific have been of single animals; however, during the 
last few years, small groups of right whales have been reported (such 
as the group of 17 documented in the Bering Sea in 2004; Angliss and 
Allen, 2008). There is evidence that the GoA was historically used as a 
feeding ground, and recent surveys suggest that some individuals 
continue to use the shelf east of Kodiak Island as a feeding area, 
which has now been designated under the ESA as critical habitat (73 FR 
19000, April 8, 2008). The North Pacific right 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 North Pacific right 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 679 exposures of minke whales to 
MFAS/HFAS at sound levels likely to result in Level B harassment will 
occur, and that two 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. It is somewhat unlikely that any minke whales 
will incur TTS because of: The distance within which they would have to 
approach the MFAS source (approximately 459 ft (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 distributed in polar, temperate, and tropical 
waters, but are less common in the tropics than in cooler waters. 
Within the Pacific EEZ, NMFS recognizes three stocks of minke whales: A 
California/Oregon/Washington stock; an Alaskan stock; and a Hawaiian 
stock. Currently, there are no estimates of abundance for minke whales 
in Alaskan waters (Angliss and Allen, 2008). In general, sightings of 
minke whales in the GoA are low. Although large numbers of minke whales 
were reported at Portlock Bank (in the TMAA) and Albatross bank (west 
of the TMAA) in May 1976 (Fiscus et al., 1976), subsequent NMFS surveys 
reported no minke whales in those locations. During the April 2009 
survey, two encounters totaling three individual minke whales occurred 
on the shelf and only one of these encounters was within the TMAA. The 
GoA TMAA activities are not expected to occur in an area/time of 
specific importance for breeding, calving, 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 328 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; one TTS take is estimated and proposed for authorization. 
However, it is unlikely that any sperm whales will incur TTS because 
of: The distance within which they would have to approach the MFAS 
source (approximately 459 ft (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, pronounced blow, and mean group size of seven).
    The acoustic analysis further predicts that one sperm whale would 
be exposed to levels of pressure and/or energy from explosive 
detonations that would result in Level B harassment. NMFS believes that 
this is unlikely because of: The distance within which they would have 
to approach the explosive source; and the likelihood that Navy monitors 
would, before or during exercise 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, and 
are broadly distributed from tropical and temperate waters to the 
Bering Sea as far north as Cape Navarin. Currently, estimates of sperm 
whale abundance in the North Pacific are not available. For the North 
Pacific, sperm whales have been divided into three separate stocks 
based on where they are found, which have been designated as (1) Alaska 
(North Pacific stock), (2) California/Oregon/Washington, and (3) Hawaii 
(Angliss and Allen, 2008). The estimated population for the North 
Pacific stock is 102,112 (CV = 0.15) (Angliss and Allen, 2008). In the 
GoA, sperm whales primarily occur seaward of the 1,640 ft (500 m) 
isobath (DoN, 2006). A survey in the Shelikof Strait (north of Kodiak), 
Cook Inlet, Prince William Sound and between Kodiak and Montique Island 
from June 26 to July 15, 2003 detected six sperm whales along the shelf 
break, with an average group size of 1.2 (Waite 2003). The April 2009 
survey in the TMAA recorded sperm whales acoustically in both the 
inshore and offshore strata, but no sperm whales were detected visually 
(Rone et al., 2009). 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.
Gray Whale
    Acoustic analysis predicts that 385 exposures of gray 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

[[Page 64570]]

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; one TTS take is 
estimated. NMFS believes that it is unlikely that a gray whale will 
incur TTS because of the distance within which they would have to 
approach the MFAS source (approximately 459 ft (140 m) for the most 
powerful source for TTS) and the fact that many animals will likely 
avoid active sonar sources to some degree. The gray whales' 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 gray whales.
    The acoustic analysis further predicts that three gray whales would 
be exposed to levels of pressure and/or energy from explosive 
detonations that would result in Level B harassment. 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.
    Gray whales occur only in the North Pacific. The Eastern North 
Pacific (ENP) population is found from the upper Gulf of California, 
south to the tip of Baja California, and up the Pacific coast of North 
America to the Chukchi and Beaufort seas. This stock is known to summer 
in the shallow waters of the northern Bering Sea, Chukchi Sea, and 
western Beaufort Sea, but some individuals spend the summer feeding 
along the Pacific coast from southeastern Alaska to central California. 
The minimum population estimates for the ENP stock of gray whales using 
the mean of the 2000/01 and 2001/02 abundance estimates is 17,752 and 
the best estimate of 18,813 whales (CV = 0.07; Angliss and Allen, 
2008). The April 2009 survey encountered one group of two gray whales 
within the western edge of the TMAA and two groups well outside the 
TMAA, nearshore at Kodiak Island (Rone et al., 2009). The GoA TMAA 
activities are not expected to occur in an area/time of specific 
importance for breeding, calving, or other known critical behaviors. 
Consequently, the activities are not expected to adversely impact rates 
of recruitment or survival of gray 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 486 Baird's beaked whales, 2,308 
Cuvier's beaked whales, and 2,308 Stejneger'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; one, six, and six (respectively, by species) TTS takes are 
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 459 ft (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 5a and Table 5b, some beaked whale vocalizations 
might overlap with the MFAS/HFAS TTS frequency range (2 to 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 one Cuvier's beaked 
whale and one Stejneger's beaked whale would be exposed to levels of 
pressure and/or energy from explosive detonations that would result in 
Level B harassment by TTS, and one Baird's beaked whale, three Cuvier's 
beaked whales, and four Stejneger's beaked whales could be exposed to 
levels associated with behavioral disturbance. It is important to note 
that, due to the lack of available density information for Stejneger's 
beaked whale, the density and results from modeling of Cuvier's beaked 
whales were used as a surrogate.
    Baird's beaked whales appear to occur mainly in cold deep water 
(3,300 ft (1,000 m) or greater) over the continental slope, oceanic 
seamounts, and in areas with submarine escarpments. They may also 
occasionally occur near shore along narrow continental shelves. The 
range for the Alaska stock of Baird's beaked whale extends from Cape 
Navarin (63 [deg]N lat.) and the central Sea of Okhotsk (57 [deg]N 
lat.) to St. Matthew Island, the Pribilof Islands in the Bering Sea, 
and the northern GoA (Angliss and Allen, 2008; DoN, 2006). Waite (2003) 
reported a group of four Baird's beaked whales at the shelf break to 
the east of the TMAA. There were no beaked whales detected acoustically 
or visually (although two groups of unidentified small whale were 
sighted) during the 2009 survey of the TMAA (Rone et al., 2009).
    Cuvier's beaked whales are considered to be the most widely 
distributed of the beaked whales. They occur in all three major oceans 
and most seas. In the North Pacific, they range north to the northern 
GoA, the Aleutian Islands, and the Commander Islands and as far south 
as Hawaii. In general, Cuvier's beaked whales are sighted in waters 
with a bottom depth greater than 656 ft (200 m) and are frequently 
recorded in areas with depths of 3,281 ft (1,000 m) or deeper. 
Occurrence has been linked to physical features such as the continental 
slope, canyons, escarpments, and oceanic islands (Angliss and Outlaw, 
2005). Waite (2003) reported one sighting of a group of four Cuvier's 
beaked whales at the shelf break within the TMAA. Other reports of 
Cuvier's beaked whales in the GoA were in very deep water. Rice and 
Wolman (1982) observed a group of six Cuvier's beaked whales in about 
14,715 ft (5,400 m) of water southeast of Kodiak Island. Surveys in the 
Aleutian Islands observed a group of six Cuvier's beaked whales in 
waters with a bottom depth of 13,123 to 16,404 ft (4,000 to 5,000 m) 
(Forney and Brown, 1996).
    Stejneger's beaked whales (also called Bering Sea beaked whales) 
are found only in the North Pacific and appear to prefer cold-temperate 
and subpolar waters. The Alaska stock is recognized as separate from 
the population off California (Angliss and Outlaw, 2007). Off Alaska, 
this species has been observed in waters ranging from a bottom depth 
ranging from 2,395 to 5,118 ft (730 to 1,560 m) on the steep slope of 
the continental shelf as it drops off into the Aleutian Basin (which 
exceeds 11,482 ft (3,500 m) in bottom depth) (DoN, 2006). Although the 
April 2009 survey in the TMAA detected no beaked whales, surveys in the 
central Aleutian Islands sighted groups of three to 15 Stejneger's 
beaked whales (Rice, 1986).
    No abundance estimates are available for any of these three species 
of beaked whale. There is only a limited amount

[[Page 64571]]

of information pertaining to the life history of beaked whales. 
Scientists have gathered some information from stranded animals, but 
little is known about how these animals express their life histories in 
the wild. Moreover, most sightings of beaked whales are brief because 
these whales are often difficult to approach and they actively avoid 
aircraft and vessels (e.g., Wursig et al., 1998). For the Stejneger's 
beaked whale, for example, there is no available information on 
reproduction and breeding. As discussed above, correlations have been 
made between bathymetric features and beaked whale sightings, which may 
indicate a habitat preference. The GoA TMAA 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.
Killer Whale (AT1 Transient Stock MMPA Depleted)
    Acoustic analysis predicts that 10,643 killer 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; 41 TTS takes are estimated. NMFS, for reasons discussed in the 
Behavioral Harassment section above, expects that these takes will have 
a negligible impact on the species. For instance, previous monitoring 
reports submitted by the Navy from more than 60 major exercises have 
indicated no observed behavioral disturbance. Although one cannot 
conclude from these results that marine mammals were not harassed and 
some of the non-biologist watchstanders might not be well qualified to 
characterize behavior, one can say that the animals observed did not 
respond in any of the obviously more severe ways, such as panic, 
aggression, or anti-predator response that would be more likely to 
adversely affect annual rates of recruitment or survival. With respect 
to the TTS takes, 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 459 ft (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 5a and Table 5b, vocalizations of these species 
might overlap with the MFAS/HFAS TTS frequency range (2 to 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 two killer whales would 
be exposed to levels of pressure and/or energy from explosive 
detonations that would result in Level B harassment by TTS, and four 
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.
    Killer whales have the most ubiquitous distribution of any marine 
mammal species, observed in virtually every marine habitat from the 
tropics to the poles and from shallow, inshore water (and even rivers) 
to deep, oceanic regions. In the eastern north Pacific, including 
Alaskan waters, killer whales are found in protected inshore waters, as 
well as offshore waters (DoN, 2006). Killer whales are segregated 
socially, genetically, and ecologically into three distinct eco-type 
groups: Residents, transients, and offshore animals; all three eco-
types are represented in the GoA. The ENP Alaskan Resident stock ranges 
from southeastern Alaska to the Aleutian Islands and Bering Sea. The 
ENP Northern Resident stock occurs from British Columbia through part 
of southeastern Alaska. There are about 656 and 216 photo-identified 
individuals in the ENP Alaska Resident and ENP Northern Resident 
stocks, respectively (Angliss and Allen, 2008).
    The minimum population estimate for the GoA, Aleutian Islands, and 
Bering Sea Transient stock is 314 individuals based on photo-
identification work. There is a minimum population estimate of 320 
individuals in the West Coast Transient stock, which includes about 225 
in Washington State and British Columbia, and southeastern Alaska, and 
105 off California. The population estimate for the ENP stock of 
Transient whales is 346. The minimum population estimate for the AT1 
Transient stock is seven individuals based on photographs from recent 
years (Angliss and Allen, 2008).
    The minimum population estimate for the ENP Offshore stock of 
killer whales is 1,214 individuals (Carretta et al., 2007). The total 
number of known offshore killer whales is 211 individuals, but the 
amount of time this transboundary stock spends in U.S. waters is 
unknown (Carretta et al., 2006).
    The GoA TMAA 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 three eco-
types of killer 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.
Pacific White-Sided Dolphins
    Acoustic analysis predicts that 16,973 Pacific white-sided dolphins 
will be exposed to MFAS/HFAS at sound levels likely to result in Level 
B harassment. 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; 61 TTS takes are 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 459 ft (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

[[Page 64572]]

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 5a and Table 5b, vocalizations of these species might overlap 
with the MFAS/HFAS TTS frequency range (2 to 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 six Pacific white-sided 
dolphins would be exposed to levels of pressure and/or energy from 
explosive detonations that would result in Level B harassment by TTS, 
and 12 could be exposed to levels associated with behavioral 
disturbance. NMFS believes that this is unlikely because of: The 
distance within which they would have to approach the explosive source; 
and the likelihood that Navy monitors would, before or during exercise 
monitoring, detect these large-grouped gregarious animals prior to an 
approach within this distance and require a delay of the exercise.
    Pacific white-sided dolphins occur across the central north Pacific 
waters to latitudes as low as (or lower than) 38 [deg]N and northward 
to the Bering Sea and coastal areas of southern Alaska. In the eastern 
north Pacific, the species occurs from the southern Gulf of California, 
north to the GoA, west to Amchitka in the Aleutian Islands, and is 
rarely encountered in the southern Bering Sea. Pacific white-sided 
dolphins occur regularly year-round throughout the GoA. They are widely 
distributed along the shelf break, continental slope, and in offshore 
waters. In Alaska, peak abundance is between July and August, when 
Pacific white-sided dolphins tend to congregate near the Fairweather 
Grounds in the southeastern GoA and Portlock Bank in the northeast part 
of the TMAA (Angliss and Allen, 2008; DoN, 2006). The minimum 
population estimate for the North Pacific stock is 26,880 (CV = 0.90) 
individuals (Angliss and Allen, 2008).
    The GoA TMAA 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 Pacific white-
sided 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 this 
species.
Porpoises
    The acoustic analysis predicts that the following numbers of Level 
B behavioral harassments of the associated species will occur: 206,374 
Dall's porpoises and 5,440 harbor porpoises. This estimate represents 
the total number of exposures and not necessarily the number of 
individuals exposed, as a single individual may be exposed multiple 
times over the course of a year.
    Although a portion (768 Dall's porpoises) of the modeled Level B 
Harassment takes for these species is predicted to be in the form of 
TTS from MFAS, NMFS believes it is unlikely that all of the individuals 
estimated will incur TTS because of the distance within which they 
would have to approach the active sonar source (approximately 459 ft 
(140 m) for the most powerful source), 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 and implement active sonar powerdown or shutdown. 
Navy lookouts will likely detect a group of dolphins given their 
relatively short dives, gregarious behavior, and large average group 
size. 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 5a and Table 5b, some porpoise vocalizations might 
overlap with the MFAS/HFAS TTS frequency range (2 to 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.
    Acoustic analysis also predicted that 37 Dall's porpoises would be 
exposed to sound or pressure from explosives at levels expected to 
result in TTS. For the same reasons noted above, NMFS anticipates that 
the Navy watchstanders would likely detect these species and implement 
the mitigation to avoid exposure. However, the range to TTS for a few 
of the larger explosives is larger than the associated exclusion zones 
for BOMBEX, MISSILEX, or SINKEX (see Table 3), and therefore NMFS 
anticipates that TTS might not be entirely avoided during those 
exercises.
    Acoustic analysis also predicted that three Dall's porpoises might 
be exposed to sound or pressure from sonar (one) and explosive 
detonations (two) that would result in PTS or injury. In addition, the 
analysis predicted that one Dall's porpoise mortality may occur as a 
result of exposure to pressure/energy levels from explosive 
detonations. For the same reasons listed above (group size, dive and 
social behavior), NMFS anticipates that the Navy watchstanders would 
detect these species and implement the mitigation measures to avoid 
exposure. In the case of all explosive exercises, the exclusion zones 
are 2-12 times larger than the estimated distance at which an animal 
would be exposed to injurious sounds or pressure waves.
    No areas of specific importance for reproduction or feeding for 
porpoises have been identified in the GoA TMAA. Table 4 shows the 
estimated abundance of the affected porpoise stocks.
    Based on the general information contained in the Negligible Impact 
Analysis section and this stock-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.
Steller Sea Lion (MMPA Depleted/ESA-Listed)
    The risk function and Navy post-modeling analysis estimates that 
11,106 Steller sea lions would be exposed to non-TTS (behavioral) Level 
B harassment, two Steller sea lions would be exposed to TTS Level B 
harassment and no Steller sea lions would be exposed to Level A 
harassment (11,105 from sonar and three from at-sea explosions). 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 the year. The short duration and 
intermittent transmission of the sonar signals, combined with 
relatively rapid vessel speed, reduces the likelihood that exposure to 
sonar sound would cause a behavioral response that may affect vital 
functions, TTS, or PTS. The set-up procedures and checks required for

[[Page 64573]]

safety of event participants make it unlikely that Steller sea lions 
would remain in an area undetected before explosive detonation 
occurred.
    The minimum abundance estimate for the western U.S. stock of 
Steller sea lions is 38,988 individuals and for the Eastern stock is 
45,095 to 55,832 (Angliss and Allen, 2008). Given the wide dispersal of 
individuals, both the western and eastern U.S. stocks may occur in the 
GoA (DoN, 2006; Angliss and Outlaw, 2007; NMFS, 2008), with about 70 
percent of the population living in Alaskan waters. Relative to the 
population size, the Navy's activities are anticipated to result only 
in a limited number of Level B harassment takes. For the GoA, foraging 
habitat is primarily shallow, nearshore, and continental shelf waters 
4.3 to 13 nm (8 to 24 km) offshore with a secondary occurrence inshore 
of the 3,289 ft (1,000 m) isobaths, and a rare occurrence seaward of 
the 3,280 ft (1,000 m) isobaths. Steller sea lions have been sighted 
foraging in the middle of the GoA (DoN, 2006). The April 2009 survey in 
the TMAA encountered two groups of Steller sea lions (Rone et al., 
2009). No aquatic foraging critical habitat exists within the TMAA. 
Steller sea lions form large rookeries during late spring and most 
births occur from mid-May through mid-July outside the boundaries of 
the TMAA. There are no known areas used by Steller sea lions for 
reproduction or calving within the TMAA. 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.
California Sea Lion
    There are not sufficient numbers of California sea lions present in 
the TMAA to allow for acoustic impact modeling. Even if an accurate 
abundance or density could be derived for these species, being so few 
in number in the TMAA, accepted modeling methodology would predict zero 
exposures. Therefore, for each proposed 21-day exercise period, the 
number of behavioral harassments will be based on an assumption of 
having exposed the average group size to one instance of behavioral 
harassment to account for all acoustic sources for purposes of this 
analysis in the TMAA. It is assumed, given that California sea lions 
are very rare in the GoA, that they would only be encountered 
individually (i.e., average group size of one) even if a prey species 
was running. In order to account for rare animals, the Navy requests 
authorization to take two California sea lions by non-TTS Level B 
harassment. No TTS Level B harassment or Level A harassment is 
anticipated.
    The abundance estimate for the U.S. stock of California sea lions 
is 238,000 individuals (Carretta et al., 2007b). This number is from 
counts during the 2001 breeding season of animals that were ashore at 
the four major rookeries in Southern California and at haulout sites 
north to the Oregon/California border. The few California sea lions 
recorded in Alaska are usually observed at Steller sea lion rookeries 
and haulout sites with most sightings recorded between March and May, 
although they may be found in the GoA throughout the year (Maniscalco 
et al., 2004; DoN, 2006). During August and September, after the mating 
season, adult male California sea lions migrate to feeding areas as far 
north as the GoA (Lowry et al., 1991). They remain there until spring 
(March-May), when they migrate southward to the breeding colonies. The 
GoA is outside of the known breeding range for California sea lions. 
There are no known areas used by California sea lions for reproduction 
or calving in the TMAA. 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.
Harbor Seal
    The Navy's acoustic analysis estimates that one harbor seal would 
be exposed to MFAS/HFAS at sound levels likely to result in Level B 
harassment. This Level B take is anticipated to be in the form of 
behavioral disturbance as described in the Definition of Harassment: 
Level B Harassment section; no TTS takes are estimated.
    The acoustic analysis further predicts that one harbor seal would 
be exposed to levels of pressure and/or energy from explosive 
detonations that would result in Level B harassment. This Level B take 
is also anticipated to be in the form of behavioral disturbance and no 
TTS takes are estimated from exposure to levels of pressure and/or 
energy from explosive detonations.
    The population estimate for the Gulf of Alaska stock of harbor 
seals is 45,975 (CV = 0.04) (Angliss and Allen, 2008). The harbor seal 
is one of the most widespread of the pinniped species distributed from 
the eastern Baltic Sea, west across the Atlantic and Pacific Oceans to 
southern Japan, along the coast and offshore islands of the GoA (DoN, 
2006). With few exceptions, harbor seals in the GoA are located in 
shallow nearshore areas and not at sea in the TMAA. Harbor seals, 
therefore, should be very rare in the small section of the TMAA nearest 
Kenai Peninsula, Montague Island, and Middleton Island. During the 
April 2009 survey, no harbor seals were encountered within the TMAA 
(Rone et al., 2009). There are harbor seal haulouts along the shoreline 
of southeast Alaska, the south side of the Alaska Peninsula, the 
Aleutian Islands, and Middleton and Montague Islands (Hoover, 1988; 
Lowrey et al., 2001; Boveng et al., 2003). However, there are no known 
preferred habitat areas used by harbor seals within the TMAA. 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.
Northern Elephant Seal
    The Navy's acoustic analysis estimates that 2,064 northern elephant 
seals would 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 the year. 
These Level B takes are anticipated to be in the form of behavioral 
disturbance as described in the Definition of Harassment: Level B 
Harassment section, and no TTS takes are estimated from exposure to 
MFAS/HFAS.
    The acoustic analysis further predicts that one northern elephant 
seal would be exposed to levels of pressure and/or energy from 
explosive detonations that would result in Level B harassment by TTS, 
and four could be exposed to levels associated with behavioral 
disturbance. NMFS believes it unlikely that a northern elephant seal 
will incur TTS because of: The distance within which they would have to 
approach to explosive source; and the likelihood that Navy monitors 
would, during pre-exercise monitoring or while an exercise is taking 
place, detect these pinnipeds (because of the relatively short duration 
of their dives and their tendency to rest near the surface) prior to an 
approach within this distance and implement the appropriate mitigation 
measures.
    The population estimate for the California Breeding stock of 
northern elephant seals is 124,000 (Carretta et al., 2007). Northern 
elephant seals are endemic to the North Pacific Ocean, occurring almost 
exclusively in the

[[Page 64574]]

eastern and central North Pacific. Individuals from the California 
breeding stock do occur regularly in the GoA year-round (Calkins, 
1986). Typically, only sub-adult and adult male elephant seals forage 
in the GoA with a peak abundance in the spring and fall (Le Boeuf et 
al., 2000). There are no known areas used by northern elephant seals 
for reproduction or calving in the TMAA. 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.
Northern Fur Seal (Eastern Pacific Stock MMPA Depleted)
    The Navy's acoustic analysis estimates that 154,160 northern fur 
seals would 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 the 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 16 TTS takes are estimated from 
exposure to MFAS/HFAS. NMFS believes it unlikely that a northern fur 
seals, for which the TTS threshold is 206 dB SEL, will incur TTS 
because of the distance within which they would have to approach the 
MFAS source (approximately 121 ft (37 m) for the most powerful source), 
the fact that many animals will likely avoid active sonar sources to 
some degree, and the likelihood that Navy monitors would detect these 
pinnipeds (because of the relatively short duration of their dives and 
their tendency to rest near the surface) prior to an approach within 
this distance and implement active sonar powerdown or shutdown. In 
addition, some northern fur seal vocalizations might overlap with the 
MFAS/HFAS TTS frequency range (2 to 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 16 northern fur seals 
would be exposed to levels of pressure and/or energy from explosive 
detonations that would result in Level B harassment by TTS, 26 could be 
exposed to levels associated with behavioral disturbance, and one Level 
A harassment may occur. NMFS believes it unlikely that a northern fur 
seal will be subject to Level A harassment or incur TTS because of: The 
distance within which they would have to approach to explosive source; 
and the likelihood that Navy monitors would, during pre-exercise 
monitoring or while an exercise is taking place, detect these pinnipeds 
(because of the relatively short duration of their dives and their 
tendency to rest near the surface) prior to an approach within this 
distance and implement the appropriate mitigation measures.
    The population estimate for the Eastern Pacific stock of northern 
fur seals is 665,550 (Angliss and Allen, 2008). Northern fur seals are 
a highly oceanic species spending all but 35 to 45 days per year at 
sea. They are usually sighted 70 to 130 km from land along the 
continental shelf and slope, seamounts, submarine canyons, and sea 
valleys, where there are upwellings of nutrient-rich water. The Eastern 
Pacific stock spends May through November inwaters and breeding 
colonies north of the GoA. In late November, females and young begin to 
arrive in offshore waters off California while adult males migrate only 
as far south as the GoA (Kajimura, 1984). Peak abundance in the TMAA 
should occur between March and June during the annual migration north 
to the Pribilof Islands breeding grounds (Fiscus et al., 1976; 
Consiglieri et al., 1982). However, some northern fur seals, 
particularly juvenile males and nonpregnant females, remain in the GoA 
throughout the summer and have been documented in the nearshore waters 
of Southeastern Alaska, Prince William Sound, Portlock Bank, and the 
middle of the GoA (Calkins, 1986; Fiscus et al., 1976). Tagging data 
presented by Ream et al. (2005) indicate that the main foraging areas 
and the main migration route through the GoA are located far to the 
west of the TMAA. There are no known rookeries or haulout sites areas 
used by northern fur seals for reproduction or pupping in the vicinity 
of the TMAA. 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.

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 GoA TMAA 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.

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 GoA 
TMAA would not have an unmitigable adverse impact on the availability 
of the affected species or stocks for subsistence use. The tribes 
nearest the GoA TMAA include the Alutiiq, Eyak, and Tlingit groups; 
however, these tribes do not use the TMAA for subsistence. In March 
2008, letter were sent to 12 tribes, including those listed above, by 
the Navy's Alaskan Command and Elemendorf Air Force Base requesting 
government-to-government consultation pursuant to Executive Order 
13175. All 12 tribes indicated that they have no concerns over the 
proposed action as described in the GoA TMAA DEIS. The Navy will 
continue to keep the tribes informed of the timeframes of future joint 
training exercises.
    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 eight marine mammal species under NMFS jurisdiction that 
are listed as endangered or threatened under the ESA with confirmed or 
possible occurrence in the TMAA: Cook Inlet beluga whale, North Pacific 
right whale, humpback whale, sei whale, fin whale, blue whale, sperm 
whale, and Steller sea lion. Typically, the Cook Inlet beluga whale 
does not leave Cook Inlet, which is approximately 70 nm (129.6 km) from 
the nearest edge of the TMAA. Based on this information, Cook Inlet 
beluga whales are considered extralimital to the TMAA and will not be 
considered further for analysis under the MMPA and the Navy has 
concluded

[[Page 64575]]

that the proposed action will have no effect on Cook Inlet beluga 
whales. If NMFS concurs with this determination, for the remaining 
seven species, the Navy will consult with NMFS pursuant to section 7 of 
the ESA, and NMFS will also consult internally on the issuance of LOAs 
under section 101(a)(5)(A) of the MMPA for GoA TMAA 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 GoA TMAA, which was 
published on December 11, 2009. 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 regulations and an LOA for GoA TMAA. If the Navy's FEIS is 
deemed inadequate, NMFS would supplement the existing analysis to 
ensure that we comply with NEPA prior to the issuance of the final rule 
or LOA.

Classification

    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 not significant for purposes of Executive Order 12866.
    Pursuant to the Regulatory Flexibility Act (RFA), the Chief Counsel 
for Regulation of the Department of Commerce has certified to the Chief 
Counsel for Advocacy of the Small Business Administration that this 
proposed rule, if adopted, would not have a significant economic impact 
on a substantial number of small entities. The RFA requires Federal 
agencies to prepare an analysis of a rule's impact on small entities 
whenever the agency is required to publish a notice of proposed 
rulemaking. However, a Federal agency may certify, pursuant to 5 U.S.C. 
605 (b), that the action will not have a significant economic impact on 
a substantial number of small entities. The Navy is the sole entity 
that will be affected by this rulemaking, not a small governmental 
jurisdiction, small organization, or small business, as defined by the 
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, Sonar, Transportation.

    Dated: October 1, 2010.
Eric C. Schwaab,
Assistant Administrator for Fisheries, 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.

    2. Subpart M is added to part 218 to read as follows:
Subpart M--Taking and Importing Marine Mammals; U.S. Navy's Gulf of 
Alaska Temporary Maritime Activities Area (GoA TMAA)
Sec.
218.120 Specified activity and geographical area.
218.121 [Reserved]
218.122 Permissible methods of taking.
218.123 Prohibitions.
218.124 Mitigation.
218.125 Requirements for monitoring and reporting.
218.126 Applications for Letters of Authorization.
218.127 Letters of Authorization.
218.128 Renewal of Letters of Authorization and adaptive management.
218.129 Modifications to Letters of Authorization.

Subpart M--Taking and Importing Marine Mammals; U.S. Navy's Gulf of 
Alaska Temporary Maritime Activities Area (GoA TMAA)


Sec.  218.120  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 may be authorized in a 
Letter of Authorization (LOA) only if it occurs within the Gulf of 
Alaska Temporary Maritime Activities Area (GoA TMAA) (as depicted in 
Figure 1-1 in the Navy's application for GoA TMAA), which is bounded by 
a hexagon with the following six corners: 57[deg]30' N. lat., 
141[deg]30' W. long.; 59[deg]36' N. lat., 148[deg]10' W. long.; 
58[deg]57' N. lat., 150[deg]04' W. long.; 58[deg]20' N. lat., 
151[deg]00' W. long.; 57[deg]16' N. lat., 151[deg]00' W. long.; and 
55[deg]30' N. lat, 142[deg]00' W. long.
    (c) The taking of marine mammals by the Navy may be authorized in 
an LOA only 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 percent):
    (i) AN/SQS-53 (hull-mounted active sonar)--up to 2,890 hours over 
the course of 5 years (an average of 578 hours per year);
    (ii) AN/SQS-56 (hull-mounted active sonar)--up to 260 hours over 
the course of 5 years (an average of 52 hours per year);
    (iii) AN/SSQ-62 (Directional Command Activated Sonobuoy System 
(DICASS) sonobuoys)--up to 1,330 sonobuoys over the course of 5 years 
(an average of 266 sonobuoys per year);
    (iv) AN/AQS-22 (helicopter dipping sonar)--up to 960 ``dips'' over 
the course of 5 years (an average of 192 ``dips'' per year);
    (v) AN/BQQ-10 (submarine hull-mounted sonar)--up to 240 hours over 
the course of 5 years (an average of 48 hours per year);
    (vi) MK-48 (torpedo)--up to 10 torpedoes over the course of 5 years 
(a maximum of 2 torpedoes per year);
    (vii) AN/SSQ-110A (IEER)--up to 400 buoys deployed over the course 
of 5 years (an average of 80 per year maximum combined use of AN/SSQ-
110A or AN/SSQ-125);
    (viii) AN/SSQ-125 (MAC)--up to 400 buoys deployed over the course 
of 5 years (an average of 80 per year maximum combined use of AN/SSQ-
110A or AN/SSQ-125);
    (ix) Range Pingers--up to 400 hours over the course of 5 years (an 
average of 80 hours per year);
    (x) SUS MK-84--up to 120 devices over the course of 5 years (an 
average of 24 per year); and

[[Page 64576]]

    (xi) PUTR Transponder--up to 400 hours over the course of 5 years 
(an average of 80 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 (Net Explosive Weight (NEW)):
    (A) 5'' Naval Gunfire (9.5 lbs NEW);
    (B) 76 mm rounds (1.6 lbs NEW);
    (C) Maverick (78.5 lbs NEW);
    (D) MK-82 (238 lbs NEW);
    (E) MK-83 (238 lbs NEW);
    (F) MK-83 (574 lbs NEW);
    (G) MK-84 (945 lbs NEW);
    (H) MK-48 (851 lbs NEW);
    (I) AN/SSQ-110A (IEER explosive sonobuoy--5 lbs NEW);
    (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 180 exercises over the course 
of 5 years (an average of 36 per year);
    (C) Sinking Exercises (SINKEX)--up to 10 exercises over the course 
of 5 years (a maximum of 2 per year);
    (D) Extended Echo Ranging and Improved Extended Echo Ranging (EER/
IEER) Systems--up to 400 deployments over the course of 5 years (an 
average of 80 per year);
    (E) Missile exercises (A-S MISSILEX)--up to 20 exercises over the 
course of 5 years (an average of 4 per year).
    (d) The taking of marine mammals may also be authorized in an LOA 
for the activities and sources listed in Sec.  218.120(c) should the 
amounts (i.e., hours, dips, number of exercises) vary from those 
estimated in Sec.  218.120(c), provided that the variation does not 
result in exceeding the amount of take indicated in Sec.  218.122.


Sec.  218.121  [Reserved]


Sec.  218.122  Permissible methods of taking.

    (a) Under Letters of Authorization issued pursuant to Sec. Sec.  
216.106 and 218.127 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.  
218.120(b), provided the activity is in compliance with all terms, 
conditions, and requirements of these regulations and the appropriate 
Letter of Authorization.
    (b) The activities identified in Sec.  218.120(c) must be conducted 
in a manner that minimizes, to the greatest extent practicable, any 
adverse impacts on marine mammals and their habitat.
    (c) The incidental take of marine mammals under the activities 
identified in Sec.  218.120(c) is limited to the species listed below 
in paragraphs (c)(4), (5), and (6) of this section by the indicated 
method of take and the indicated number of times (estimated based on 
the authorized amounts of sound source operation), but with the 
following allowances for annual variation in activities:
    (1) In any given year, annual take, by harassment, of any species 
of marine mammal may not exceed the amount identified in paragraphs 
(c)(4) and (5) of this section, for that species by more than 25 
percent (a post-calculation/estimation of which must be provided in the 
annual LOA application);
    (2) In any given year, annual take by harassment of all marine 
mammal species combined may not exceed the estimated total of all 
species combined, indicated in paragraphs (c)(4) and (5) of this 
section, by more than 10 percent; and
    (3) Over the course of the effective period of this subpart, total 
take, by harassment, of any species may not exceed the 5-year amounts 
indicated in paragraphs (c)(4) and (5) of this section by more than 10 
percent. A running calculation/estimation of takes of each species over 
the course of the years covered by the rule must be maintained.
    (4) Level B Harassment:
    (i) Mysticetes:
    (A) Humpback whale (Megaptera novaeangliae)--6,975 (an average of 
1,395 annually);
    (B) Fin whale (Balaenoptera physalus)--55,185 (an average of 11,037 
annually);
    (C) Blue whale (Balaenoptera musculus)--10 (an average of 2 
annually);
    (D) Sei whale (Balaenoptera borealis)--40 (an average of 8 
annually);
    (E) Minke whale (Balaenoptera acutorostrata)--3,405 (an average of 
681 annually);
    (F) Gray whale (Eschrichtius robustus)--1,940 (an average of 388 
annually); and
    (G) North Pacific right whale (Eubalaena japonica)--10 (an average 
of 2 annually).
    (ii) Odontocetes:
    (A) Sperm whales (Physeter macrocephalus)--1,645 (an average of 329 
annually);
    (B) Killer whale (Orcinus orca)--53,245 (an average of 10,649 
annually);
    (C) Harbor porpoise (Phocoena phocoena)--27,200 (an average of 
5,440 annually);
    (D) Baird's beaked whales (Berardius bairdii)--2,435 (an average of 
487 annually);
    (E) Cuvier's beaked whales (Ziphius cavirostris)--11,560 (an 
average of 2,312 annually);
    (F) Stejneger's beaked whales (Mesoplodon stejnegeri)--11,565 (an 
average of 2,313 annually);
    (G) Pacific white-sided dolphin (Lagenorhynchus obliquidens)--
84,955 (an average of 16,991 annually); and
    (H) Dall's porpoise (Phocoenoides dalli)--1,031,870 (an average of 
206,374 annually).
    (iii) Pinnipeds:
    (A) Steller sea lion (Eumetopias jubatus)--55,540 (an average of 
11,108 annually)
    (B) California sea lion (Zalophus californianus)--10 (an average of 
2 annually);
    (C) Harbor seal (Phoca vitulina richardsi)--10 (an average of 2 
annually);
    (D) Northern elephant seal (Mirounga angustirostris)--10,345 (an 
average of 2,069 annually); and
    (E) Northern fur seal (Callorhinus ursinus)--771,010 (an average of 
154,202 annually).
    (5) Level A Harassment and/or mortality of no more than 15 beaked 
whales (total), of any of the species listed in Sec.  
218.122(c)(1)(ii)(D) through (F) over the course of the 5-year 
regulations.


Sec.  218.123  Prohibitions.

    No person in connection with the activities described in Sec.  
218.120 may:
    (a) Take any marine mammal not specified in Sec.  218.122(c);
    (b) Take any marine mammal specified in Sec.  218.122(c) other than 
by incidental take as specified in Sec. Sec.  218.122(c)(1), (c)(2), 
and (c)(3);
    (c) Take a marine mammal specified in Sec.  218.122(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 218.127 of this chapter.


Sec.  218.124  Mitigation.

    (a) When conducting training and utilizing the sound sources or 
explosives identified in Sec.  218.120(c), the mitigation measures 
contained in a Letter of Authorization issued under Sec. Sec.  216.106 
and 218.127 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

[[Page 64577]]

aircrews, and Anti-submarine Warfare (ASW) 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 
shall 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 shall 
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 shall 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.
    (xi) Naval vessels shall maneuver to keep at least 1,500 ft (500 yd 
or 457 m) away from any observed whale in the vessel's path and avoid 
approaching whales head-on. These requirements do not apply if a 
vessel's safety is threatened, such as when change of course will 
create an imminent and serious threat to a person, vessel, or aircraft, 
and to the extent vessels are restricted in their ability to maneuver. 
Restricted maneuverability includes, but is not limited to, situations 
when vessels are engaged in dredging, submerged activities, launching 
and recovering aircraft or landing craft, minesweeping activities, 
replenishment while underway and towing activities that severely 
restrict a vessel's ability to deviate course. Vessels shall take 
reasonable steps to alert other vessels in the vicinity of the whale. 
Given rapid swimming speeds and maneuverability of many dolphin 
species, naval vessels would maintain normal course and speed on 
sighting dolphins unless some condition indicated a need for the vessel 
to maneuver.
    (3) Operating Procedures (for Anti-submarine Warfare (ASW) 
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 
shall 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 yd 
(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 yd (183 m) of 
a marine

[[Page 64578]]

mammal and shall cease pinging if a marine mammal closes within 200 yd 
(183 m) after pinging has begun.
    (x) Safety Zones--When marine mammals are detected by any means 
(aircraft, shipboard lookout, or acoustically) within 1,000 yd (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-53 and 
219 for AN/SQS-56, etc.).
    (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 1,000-yd (914 m) exclusion zone, has not been detected for 
30 minutes, or the vessel has transited more than 2,000 yds (1,829 m) 
beyond the location of the last detection.
    (B) Should a marine mammal be detected within 500 yd (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-53 and 215 for AN/SQS-56, 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 (457 m) safety zone (at 
which point the 6-dB powerdown applies until the animal leaves the 
1,000-yd (914 m) safety zone), has not been detected for 30 minutes, or 
the vessel has transited more than 2,000 yd (1,829 m) beyond the 
location of the last detection.
    (C) Should the marine mammal be detected within 200 yd (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 (183 m) 
safety zone (at which point the 10-dB or 6-dB powerdowns apply until 
the animal leaves the 500-yd (457 m) or 1,000-yd (914 m) safety zone, 
respectively), has not been detected for 30 minutes, or the vessel has 
transited more than 2,000 yd (1,829 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 shall 
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 shall 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 is 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) 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) shall 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), shall 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 shall 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 shall be maintained throughout the 
exercise. Additionally, passive sonar onboard submarines may be 
utilized to detect any vocalizing marine mammals in the area. The OCE 
shall be informed of any aural detection of marine mammals and shall 
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 shall be delayed until the animal is re-sighted 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 shall 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.

[[Page 64579]]

    (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 can be adequately monitored visually. Should low 
cloud cover or surface visibility prevent adequate visual monitoring as 
described previously, the exercise shall be delayed until conditions 
improved, and all of the above monitoring criteria can 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.
    (5) 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 
shall immediately notify the firing vessel, which shall suspend the 
exercise until the area is clear.
    (ii) A 600-yd (585 m) radius buffer zone shall be established 
around the intended target.
    (iii) 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. 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 shall be conducted only when the buffer zone is 
visible and marine mammals are not detected within it.
    (6) 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.
    (7) Surface-to-Air Gunnery (Explosive and Non-explosive Rounds):
    (i) Vessels shall orient the geometry of gunnery exercises in order 
to prevent debris from falling in the area of sighted marine mammals.
    (ii) Vessels shall expedite the attempt to recover 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 shall immediately notify the firing vessel in order to secure 
gunnery firing until the area is clear.
    (8) Air-to-Surface Gunnery (Explosive and Non-explosive Rounds):
    (i) A 200-yd (183 m) radius buffer zone shall be established around 
the intended target.
    (ii) If surface vessels are involved, lookout(s) shall visually 
survey the buffer zone for marine mammals to and during the exercise.
    (iii) Aerial surveillance of the buffer zone for marine mammals 
shall be conducted prior to commencement of the exercise. Aerial 
surveillance altitude of 500 ft to 1,500 ft (152-456 m) is optimum. 
Aircraft crew/pilot shall 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 shall be conducted only if marine mammals are not 
visible within the buffer zone.
    (9) Small Arms Training (Grenades, Explosive and Non-explosive 
Rounds)--Lookouts shall visually survey for marine mammals. Weapons 
shall not be fired in the direction of known or observed marine 
mammals.
    (10) 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 yd (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 (457 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,'' shall clear the target area and perform the clearance and 
observation functions required before the dropping plane may release 
its weapons. Both planes shall 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 shall assure it has visual site of the target area at a 
maximum height of 1,500 ft (457 m). The clearing plane shall 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 shall be conducted only if marine mammals are not 
visible within the buffer zone.
    (11) Air-to-Surface At-Sea Bombing Exercises (Non-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 yd (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 (457 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,'' shall 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 shall assure it has visual site of the target area at a

[[Page 64580]]

maximum height of 1,500 ft (457 m). The clearing plane shall 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 shall be conducted only if marine mammals and are 
not visible within the buffer zone.
    (12) Air-to-Surface Missile Exercises (explosive and non-
explosive):
    (i) Aircraft shall visually survey the target area for marine 
mammals. Visual inspection of the target area shall be made by flying 
at 1,500 ft (457 m) or lower, if safe to do so, and at the 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 yd (1646 m) of sighted marine mammals.
    (13) Aircraft Training Activities Involving Non-Explosive Devices: 
Non-explosive devices such as some sonobuoys and inert bombs 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.
    (14) 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 500 yd (457 m) 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) shall be deployed within 1,000 yd (914 m) 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 1,000 yd (914 m) 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 1,000 yd (914 m) 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 1,000-yd (914 
m) safety buffer. Aircrews may shift their multi-static active search 
to another post, where marine mammals are outside the 1,000-yd (914 m) 
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 shall ensure that a 1,000-yd (914 m) 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 shall 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 cannot be scuttled shall 
be reported as unexploded ordnance via voice communications while 
airborne, then upon landing via naval message.
    (x) Marine mammal monitoring shall continue until out of own-
aircraft sensor range.
    (15) The Navy shall abide by the letter of the ``Stranding Response 
Plan for Major Navy Training Exercises in the GoA TMAA'' (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 GoA TMAA), the Navy shall implement the 
procedures described below.
    (A) The Navy shall implement a Shutdown (as defined in the 
Stranding Response Plan for GoA TMAA) when advised by a NMFS Office of 
Protected Resources Headquarters Senior Official designated in the GoA 
TMAA Stranding Communication Protocol that a USE (as defined in the 
Stranding Response Plan for the GoA TMAA) 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.
    (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 the species or description of the animal(s), the condition of the 
animal(s) including carcass condition if the animal(s) is/are dead), 
location, time of first discovery, observed behavior(s) (if alive), and 
photo or video of the animal(s) (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: qualified individuals are 
attempting to herd animals back out to the open ocean and animals are 
not willing to leave, or animals are seen repeatedly heading for the 
open ocean but turning back to shore, NMFS and the Navy shall 
coordinate (including an investigation of other potential anthropogenic 
stressors in the area) to determine if the proximity of 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

[[Page 64581]]

likelihood and implement those measures as appropriate.
    (ii) Within 72 hrs of NMFS notifying the Navy of the presence of a 
USE, the Navy shall provide available information to NMFS (per the GoA 
TMAA 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 hrs prior to the USE 
event. Information not initially available regarding the 80 nm (148 km) 
and 72 hrs 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.  218.125  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 shall provide 
NMFS with the 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 behavior(s) (if alive), and 
photo or video of the animal(s) (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 shall 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 (e.g., 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 GoA TMAA 
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 December 15 
describing the implementation and results (through October of the same 
year) of the monitoring required in paragraph (c) of this section. The 
Navy shall 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 15 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 GoA TMAA Report--The Navy shall submit an Annual 
Exercise GoA TMAA Report on December 15 of every year (covering data 
gathered through October). This report shall contain the subsections 
and information indicated below.
    (1) MFAS/HFAS Training Exercises--This section shall contain the 
following information for the following Coordinated and Strike Group 
Exercises: Joint Multi-strike Group Exercises; Joint Expeditionary 
Exercises; and Marine Air Ground Task Force GoA TMAA:
    (i) Exercise Information (for each exercise):
    (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 exercise):
    (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);
    (G) Length of time observers maintained visual contact with marine 
mammal(s);
    (H) Wave height (ft);
    (I) Visibility;
    (J) Sonar source in use (y/n);
    (K) Indication of whether animal is <200 yd, 200-500 yd, 500-1,000 
yd, 1,000-2,000 yd, or >2,000 yd from sonar source in (x) above;
    (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 (x) is hull-mounted, true bearing of animal 
from ship, true direction of ship's travel, and estimation of animal's 
motion relative to ship (opening, closing, parallel); 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 
exercises) 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.)).

[[Page 64582]]

    (ii) Cumulative Impacts--To the extent practicable, the Navy, in 
coordination with NMFS, shall develop and implement a method of 
annually reporting other training (i.e., Unit Level Training (ULT)) 
utilizing hull-mounted sonar. The report shall present an annual (and 
seasonal, where practicable) depiction of non-major training exercises 
geographically across the GoA TMAA. The Navy shall include (in the GoA 
TMAA 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 (ft);
    (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 (762 m for SINKEX in the GoA 
TMAA);
    (2) The required exclusion zone (1 nm for SINKEX in the GoA TMAA);
    (3) The required observation distance (if different than the 
exclusion zone (2 nm for SINKEX in the GoA TMAA); and
    (4) Greater than the required observed distance. For example, in 
this case, the observer shall indicate if <762 m, from 762 m-1 nm, from 
1 nm-2 nm, and > 2 nm.
    (K) 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.), 
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 the GoA TMAA;
    (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 shall 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 the GoA TMAA; and
    (ii) Total annual expended/detonated rounds (missiles, bombs, etc.) 
for each explosive type.
    (g) GoA TMAA 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 GoA TMAA Exercise Reports 
and GoA TMAA Monitoring Plan Reports). This report shall be submitted 
at the end of the fourth year of the rule (December 2014), covering 
activities that have occurred through October 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 Mariana Islands Range Complex, and the Gulf 
of Alaska.
    (i) The Navy shall comply with the 2009 Integrated Comprehensive 
Monitoring Program (ICMP) Plan and continue to improve the program in 
consultation with NMFS. Changes and improvements to the program made 
during 2010 (as prescribed in the 2009 ICMP and deemed appropriate by 
the Navy and NMFS) will be described in an updated 2010 ICMP and 
submitted to NMFS by October 31, 2010, for review. An updated 2010 ICMP 
will be finalized by December 31, 2010.


Sec.  218.126  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.  218.120(c) (i.e., the Navy) 
must apply for and obtain either an initial Letter of Authorization in 
accordance with Sec.  218.127 or a renewal under Sec.  218.128.


Sec.  218.127  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 or biennially subject to renewal 
conditions in Sec.  218.128.
    (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).

[[Page 64583]]

Sec.  218.128  Renewal of Letters of Authorization and adaptive 
management.

    (a) A Letter of Authorization issued under Sec.  216.106 and Sec.  
218.127 of this chapter or the activity identified in Sec.  218.120(c) 
shall be renewed annually or biennially upon:
    (1) Notification to NMFS that the activity described in the 
application submitted under Sec.  218.126 shall be undertaken and that 
there will not be a substantial modification to the described work, 
mitigation or monitoring undertaken during the upcoming 12-24 months;
    (2) Receipt of the monitoring reports and notifications within the 
indicated timeframes required under Sec.  218.125(b through j); and
    (3) A determination by NMFS that the mitigation, monitoring, and 
reporting measures required under Sec.  218.124 and the Letter of 
Authorization issued under Sec. Sec.  216.126 and 218.127 of this 
chapter were undertaken and will be undertaken during the upcoming 
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.  216.126 and 216.128 indicates that a substantial 
modification, as determined by NMFS, to the described work, mitigation 
or monitoring undertaken during the upcoming season will occur, 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 GoA TMAA 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 
GoA TMAA 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.  218.129  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.  216.126 
and 218.127 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.  218.128, 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.  218.120(b), a Letter of 
Authorization issued pursuant to Sec. Sec.  216.126 and 218.127 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. 2010-25230 Filed 10-18-10; 8:45 am]
BILLING CODE 3510-22-P