Takes of Marine Mammals Incidental to Specified Activities; U.S. Navy Training and Testing Activities in the Atlantic Fleet Training and Testing Study Area

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 218

[Docket No. 130109022-3022-01]

RIN 0648-BC53

Takes of Marine Mammals Incidental to Specified Activities; U.S. Navy Training and Testing Activities in the Atlantic Fleet Training and Testing Study Area

AGENCY:

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

ACTION:

Notice of proposed rulemaking; request for comments and information.

SUMMARY:

NMFS has received a request from the U.S. Navy (Navy) for authorization to take marine mammals incidental to the training and testing activities conducted in the Atlantic Fleet Training and Testing (AFTT) study area from January 2014 through January 2019. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposal to issue regulations and subsequent Letters of Authorization (LOAs) to the Navy to incidentally harass marine mammals.

DATES:

Comments and information must be received no later than March 11, 2013.

ADDRESSES:

You may submit comments, identified by 0648-BC53, by either of the following methods:

• Electronic submissions: submit all electronic public comments via the Federal eRulemaking Portal

http://www.regulations.gov

• Hand delivery of mailing of paper, disk, or CD-ROM comments should be addressed to P. Michael Payne, Chief, Permits and Conservation Division, Office of Protected Resources, National Marine Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910-3225.

Instructions: All comments received are a part of the public record and will generally be posted to

http://www.regulations.gov

without change. All Personal Identifying Information (for example, name, address, etc.) voluntarily submitted by the commenter may be publicly accessible. Do not submit Confidential Business Information or otherwise sensitive or protected information.

NMFS will accept anonymous comments (enter N/A in the required fields if you wish to remain anonymous). Attachments to electronic comments will be accepted in Microsoft Work, Excel, WordPerfect, or Adobe PDF file formats only.

FOR FURTHER INFORMATION CONTACT:

Brian D. Hopper, Office of Protected Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Availability

A copy of the Navy's application may be obtained by visiting the internet at:

http://www.nmfs.noaa.gov/pr/permits/incidental.htm

. The Navy's Draft Environmental Impact Statement/Overseas Environmental Impact Statement (DEIS/OEIS) for AFTT was made available to the public on May 11, 2012 (77 FR 27742). Documents cited in this notice may also be viewed, by appointment, during regular business hours, at the aforementioned address.

Background

Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361

et seq.

) direct the Secretary of Commerce to allow, upon request, the incidental, but not intentional, taking of small numbers of marine mammals by U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region if certain findings are made and either regulations are issued or, if the taking is limited to harassment, a notice of a proposed authorization is provided to the public for review.

Authorization for incidental takings shall be granted if NMFS finds that the taking will have a negligible impact on the species or stock(s), will not have an unmitigable adverse impact on the availability of the species or stock(s) for subsistence uses (where relevant), and if the permissible methods of taking and requirements pertaining to the mitigation, monitoring, and reporting of such takings are set forth. NMFS has defined “negligible impact” in 50 CFR 216.103 as “* * * an impact resulting from the specified activity that cannot be reasonably expected to, and is not reasonably likely to, adversely affect the species or stock through effects on annual rates of recruitment or survival.”

The National Defense Authorization Act of 2004 (NDAA) (Pub. L. 108-136) removed the “small numbers” and “specified geographic region” limitations indicated above and amended the definition of “harassment” as applied to “military readiness activity” to read as follows (Section 3(18)(B) of the MMPA: “(i) Any act that injures or has the significant potential to injure a marine mammal or marine mammal stock in the wild [Level A Harassment]; or (ii) any act that disturbs or is likely to disturb a marine mammal or marine mammal stock in the wild by causing disruption of natural behavioral patterns, including, but not limited to, migration, surfacing, nursing, breeding, feeding, or sheltering, to a point where such behavioral patterns are abandoned or significantly altered [Level B Harassment].”

Summary of Request

On April 13, 2012, NMFS received an application from the Navy requesting regulations and two LOAs for the take of 42 species of marine mammals incidental to Navy training and testing activities to be conducted in the AFTT Study Area over 5 years. The Navy submitted addendums on September 24, 2012 and December 21, 2012, and the application was considered complete. This proposed rule is based on the information contained in the revised LOA applications. The Navy is requesting regulations that would establish a process for authorizing take, via two separate 5-year LOAs, of marine mammals for training activities and for testing activities, each proposed to be conducted from 2014 through 2019. The Study Area includes several existing study areas, range complexes, and testing ranges (Atlantic Fleet Active Sonar Training (AFAST), Northeast, Virginia Capes (VACAPES), Cherry Point (CHPT), Jacksonville (JAX), Gulf of Mexico (GOMEX), Naval Surface Warfare Center, Panama City, Naval Undersea Warfare Center Newport, South Florida Ocean Measurement Facility (SFOMF), and Key West) plus pierside locations and areas on the high seas where maintenance, training, or testing may occur. The proposed activities are classified as military readiness activities. Marine mammals present in the Study Area may be exposed to sound from active sonar, underwater detonations, and/or pile driving and removal. In addition, incidental takes of marine mammals may occur from ship strikes. The Navy requests authorization to take individuals of 42 marine mammal species by Level B harassment and individuals of 32 marine mammal species by Level A harassment. In addition, the Navy requests authorization for take by serious injury or mortality individuals of 16 marine mammal species due to the use of explosives, and 11 total marine mammals (any species except North Atlantic right whale) over the course of the 5-year rule due to vessel strike.

The Navy's application and the AFTT DEIS/OEIS contain proposed acoustic criteria and thresholds that would, in some instances, represent changes from what NMFS has used to evaluate the

Navy's proposed activities for past incidental take authorizations. The revised thresholds are based on evaluations of recent scientific studies; a detailed explanation of how they were derived is provided in the AFTT DEIS/OEIS Criteria and Thresholds Technical Report. NMFS is currently updating and revising all of its acoustic criteria and thresholds. Until that process is complete, NMFS will continue its long-standing practice of considering specific modifications to the acoustic criteria and thresholds currently employed for incidental take authorizations only after providing the public with an opportunity for review and comment. NMFS is requesting comments on all aspects of the proposed rule, and specifically requests comment on the proposed acoustic criteria and thresholds.

Background of Request

The Navy's mission is to maintain, train, and equip combat-ready naval forces capable of winning wars, deterring aggression, and maintaining freedom of the seas. Section 5062 of Title 10 of the United States Code directs the Chief of Naval Operations to train all military forces for combat. The Chief of Naval Operations meets that directive, in part, by conducting at-sea training exercises and ensuring naval forces have access to ranges, operating areas (OPAREAs) and airspace where they can develop and maintain skills for wartime missions and conduct research, development, testing, and evaluation (RDT&E) of naval systems.

The Navy proposes to continue conducting training and testing activities within the AFTT Study Area, which have been ongoing since the 1940s. Recently, most of these activities were analyzed in six separate EISs completed between 2009 and 2011; the Atlantic Fleet Active Sonar Training (AFAST) EIS/OEIS (U.S. Department of the Navy, 2009a), the Virginia Capes Range Complex (VACAPES) EIS/OEIS (U.S. Department of the Navy, 2009b), the Navy Cherry Point Range Complex (CHPT) EIS/OEIS (U.S. Department of the Navy, 2009c), the Jacksonville Range Complex (JAX) EIS/OEIS (U.S. Department of the Navy, 2009d), the Panama City (PCD) EIS/OEIS (U.S. Department of the Navy, 2009e), and the Gulf of Mexico (GOMEX) EIS/OEIS (U.S. Department of the Navy, 2011). These documents, among others, and their associated MMPA regulations and authorizations, describe the baseline of training and testing activities currently conducted in the Study Area. The tempo and types of training and testing activities have fluctuated due to changing requirements; new technologies; the dynamic nature of international events; advances in warfighting doctrine and procedures; and changes in basing locations for ships, aircraft, and personnel. Such developments influence the frequency, duration, intensity, and location of required training and testing. The Navy's request covers training and testing activities that would occur for a 5-year period following the expiration of the current MMPA authorizations for AFAST, VACAPES, CHPT, JAX, and GOMEX. The Navy has also prepared a DEIS/OEIS analyzing the effects on the human environment of implementing their preferred alternative (among others).

The quantified results of the marine mammal acoustic effects analysis presented in the Navy's LOA application differ from the quantified results presented in the AFTT DEIS/OEIS. The differences are due to three main factors: (1) Changes to tempo or location of certain training and testing activities; (2) refinement to the modeling inputs for training and testing; and (3) additional post-model analysis of acoustic effects to include animal avoidance of repeated sound sources, avoidance of areas of activity before use of a sound source or explosive by sensitive species, and implementation of mitigation. The additional post-model analysis of acoustic effects was performed to clarify potential misunderstandings of the numbers presented as modeling results in the AFTT DEIS/OEIS. Some comments indicated that the readers believed the acoustic effects to marine mammals presented in the DEIS/OEIS were representative of the actual expected effects, although the AFTT DEIS/OEIS did not account for animal avoidance of an area prior to commencing sound-producing activities, animal avoidance of repeated explosive noise exposures, and the protections due to standard Navy mitigations. The net result of these changes is an overall decrease in takes in the Mortality and Level A takes within the LOA application compared with the DEIS, a net reduction in Level B takes for training, and a net increase in Level B takes for testing. The Navy has advised NMFS that all comments received on the proposed rule that address: (1) Changes to the tempo or location of certain proposed activities; (2) refinement to the modeling inputs for training and testing; and (3) additional post-model analysis of acoustic effects and implementation of mitigation, will be reviewed and addressed by the Navy in its FEIS/OEIS for AFTT.

Description of the Specified Activity

The Navy requests authorization to take marine mammals incidental to conducting training and testing activities. The Navy has determined that non-impulsive sources (e.g. sonar), underwater detonations, pile driving and removal, and vessel strikes are the stressors most likely to result in impacts on marine mammals that could rise to the level of harassment. Detailed descriptions of these activities are provided in the Navy's Draft Environmental Impact Statement (DEIS) and LOA application (

http://www.nmfs.noaa.gov/pr/permits/incidental.htm

) and summarized here.

Overview of Training Activities

The Navy routinely trains in the AFTT Study Area in preparation for national defense missions. Training activities are categorized into eight functional warfare areas (anti-air warfare; amphibious warfare; strike warfare; anti-surface warfare; anti-submarine warfare; electronic warfare; mine warfare; and naval special warfare). The Navy determined that stressors used in the following warfare areas are most likely to result in impacts on marine mammals:

• Amphibious warfare (underwater detonations, pile driving and removal)

• Anti-surface warfare (underwater detonations)

• Anti-submarine warfare (active sonar, underwater detonations)

• Mine warfare (active sonar, underwater detonations)

• Naval special warfare (underwater detonations)

The Navy's activities in anti-air warfare, strike warfare, and electronic warfare do not produce stressors that could result in harassment of marine mammals. Therefore, these activities are not discussed further.

Amphibious Warfare

The mission of amphibious warfare is to project military power from the sea to the shore through the use of naval firepower and Marine Corps landing forces. The Navy uses amphibious warfare to attack a threat located on land by a military force embarked on ships. Amphibious warfare training ranges from individual, crew, and small unit events to large task force exercises. Individual and crew training include amphibious vehicles and naval gunfire support training for shore assaults, boat raids, airfield or port seizures, and reconnaissance. Large-scale amphibious exercises involve ship-to-shore

maneuver, naval fire support, such as shore bombardment, and air strike and close air support training. However, the Navy only analyzed those portions of amphibious warfare training that occur at sea, in particular, underwater detonations associated with naval gunfire support training. The Navy conducts other amphibious warfare support activities that could potentially impact marine mammals (such as pile driving and removal) in the near shore region from the beach to about 914 m from shore.

Anti-Surface Warfare

The mission of anti-surface warfare is to defend against enemy ships or boats. When conducting anti-surface warfare, aircraft use cannons, air-launched cruise missiles, or other precision munitions (guided and unguided); ships use naval guns, and surface-to-surface missiles; and submarines use torpedoes or submarine-launched, anti-ship cruise missiles. Anti-surface warfare training includes surface-to-surface gunnery and missile exercises, air-to-surface gunnery and missile exercises, and submarine missile or exercise torpedo launch events.

Anti-Submarine Warfare

The mission of anti-submarine warfare is to locate, neutralize, and defeat hostile submarine threats to surface forces. Anti-submarine warfare is based on the principle of a layered defense of surveillance and attack aircraft, ships, and submarines all searching for hostile submarines. These forces operate together or independently to gain early warning and detection, and to localize, track, target, and attack hostile submarine threats. Anti-submarine warfare training addresses basic skills such as detection and classification of submarines, distinguishing between sounds made by enemy submarines and those of friendly submarines, ships, and marine life. More advanced, integrated anti-submarine warfare training exercises are conducted in coordinated, at-sea training events involving submarines, ships, and aircraft. This training integrates the full spectrum of anti-submarine warfare from detecting and tracking a submarine to attacking a target using either exercise torpedoes or simulated weapons.

Mine Warfare

The mission of mine warfare is to detect, and avoid or neutralize mines to protect Navy ships and submarines and to maintain free access to ports and shipping lanes. Mine warfare also includes offensive mine laying to gain control or deny the enemy access to sea space. Naval mines can be laid by ships, submarines, or aircraft. Mine warfare training includes exercises in which ships, aircraft, submarines, underwater vehicles, or marine mammal detection systems search for mines. Certain personnel train to destroy or disable mines by attaching and detonating underwater explosives to simulated mines. Other neutralization techniques involve impacting the mine with a bullet-like projectile or intentionally triggering the mine to detonate.

Naval Special Warfare

The mission of naval special warfare is to conduct unconventional warfare, direct action, combat terrorism, special reconnaissance, information warfare, security assistance, counter-drug operations, and recovery of personnel from hostile situations. Naval special warfare operations are highly specialized and require continual and intense training. Naval special warfare units are required to utilize a combination of specialized training, equipment, and tactics, including insertion and extraction operations using parachutes, submerged vehicles, rubber boats, and helicopters; boat-to-shore and boat-to-boat gunnery; underwater demolition training; reconnaissance; and small arms training.

Overview of Testing Activities

The Navy researches, develops, tests, and evaluates new platforms, systems, and technologies. Testing activities may occur independently of or in conjunction with training activities. Many testing activities are conducted similarly to Navy training activities and are also categorized under one of the primary mission areas. Other testing activities are unique and are described within their specific testing categories. The Navy determined that stressors used during the following testing activities are most likely to result in impacts on marine mammals:

• Naval Air Systems Command (NAVAIR) Testing

• Anti-surface warfare testing (underwater detonations)

• Anti-submarine warfare testing (active sonar, underwater detonations)

• Mine warfare testing (active sonar, underwater detonations)

• Naval Sea Systems Command (NAVSEA) Testing

• New ship construction (active sonar, underwater detonations)

• Shock trials (underwater detonations)

• Life cycle activities (active sonar, underwater detonations)

• Range Activities (active sonar, underwater detonations)

• Anti-surface warfare/anti-submarine warfare testing (active sonar, underwater detonations)

• Mine warfare testing (active sonar, underwater detonations)

• Ship protection systems and swimmer defense testing (active sonar, airguns)

• Unmanned vehicle testing (active sonar)

• Other testing (active sonar)

• Office of Naval Research (ONR) and Naval Research Laboratory (NRL) Testing

• ONR/NRL Research, Development, Test & Evaluation (active sonar)

Other Navy testing activities that do not involve underwater non-impulse sources or impulse sources that could result in marine mammal harassment are not discussed further.

Naval Air Systems Command Testing (NAVAIR)

NAVAIR events include testing of new aircraft platforms, weapons, and systems before delivery to the fleet for training activities. NAVAIR also conducts lot acceptance testing of weapons and systems, such as sonobuoys. In general, NAVAIR conducts its testing activities the same way the fleet conducts its training activities. However, NAVAIR testing activities may occur in different locations than equivalent fleet training activities and testing of a particular system may differ slightly from the way the fleet trains with the same system.

Anti-Surface Warfare Testing

Anti-surface warfare testing includes air-to-surface gunnery, missile, and rocket exercises. Testing is required to ensure the equipment is fully functional for defense from surface threats. Testing may be conducted on new guns or gun rounds, missiles, rockets, and aircraft, and also in support of scientific research to assess new and emerging technologies. Testing events are often integrated into training activities and in most cases the systems are used in the same manner in which they are used for fleet training activities.

Anti-Submarine Warfare Testing

Anti-submarine warfare testing addresses basic skills such as detection and classification of submarines, distinguishing between sounds made by enemy submarines and those of friendly submarines, ships, and marine life. More advanced, integrated anti-submarine warfare testing is conducted in coordinated, at-sea training events involving submarines, ships, and

aircraft. This testing integrates the full spectrum of anti-submarine warfare from detecting and tracking a submarine to attacking a target using various torpedoes and weapons.

Mine Warfare Testing

Mine warfare testing includes activities in which aircraft detection systems are used to search for and record the location of mines for subsequent neutralization. Mine neutralization tests evaluate a system's effectiveness at intentionally detonating or otherwise disabling the mine. Different mine neutralization systems are designed to neutralize mines either at the sea surface or deployed deeper within the water column. All components of these systems are tested in the at-sea environment to ensure they meet mission requirements.

Naval Sea Systems Command Testing (NAVSEA)

NAVSEA testing activities are aligned with its mission of new ship construction, shock trials, life cycle activities, range activities, and other weapon systems development and testing.

New Ship Construction Activities

Ship construction activities include pierside testing of ship systems, tests to determine how the ship performs at-sea (sea trials), and developmental and operational test and evaluation programs for new technologies and systems. Pierside and at-sea testing of systems aboard a ship may include sonar, acoustic countermeasures, radars, and radio equipment. During sea trials, each new ship propulsion engine is operated at full power and subjected to high-speed runs and steering tests. At-sea test firing of shipboard weapon systems, including guns, torpedoes, and missiles, are also conducted.

Shock Trials

One ship of each new class (or major upgrade) of combat surface ships constructed for the Navy may undergo an at-sea shock trial. A shock trial is a series of underwater detonations that send a shock wave through the ship's hull to simulate near misses during combat. A shock trial allows the Navy to validate the shock hardness of the ship and assess the survivability of the hull and ship's systems in a combat environment as well as the capability of the ship to protect the crew.

Life Cycle Activities

Testing activities are conducted throughout the life of a Navy ship to verify performance and mission capabilities. Sonar system testing occurs pierside during maintenance, repair, and overhaul availabilities, and at sea immediately following most major overhaul periods. A Combat System Ship Qualification Trial is conducted for new ships and for ships that have undergone modification or overhaul of their combat systems.

Radar cross signature testing of surface ships is conducted on new vessels and periodically throughout a ship's life to measure how detectable the ship is by radar. Electromagnetic measurements of off-board electromagnetic signatures are also conducted for submarines, ships, and surface craft periodically.

Range Activities

NAVSEA's testing ranges are used to conduct principal testing, analysis, and assessment activities for ship and submarine platforms, including ordnance, mines, and machinery technology for surface combat systems. Naval Surface Warfare Center, Panama City Division Testing Range focuses on surface warfare tests that often involve mine countermeasures. Naval Undersea Warfare Center Division, Newport Testing Range focuses on the undersea aspects of warfare and is, therefore, structured to test systems such as torpedoes and unmanned underwater vehicles. The South Florida Ocean Measurement Facility Testing Range retains a unique capability that focuses on signature analysis operations and mine warfare testing events.

Other Weapon Systems Development and Testing

Numerous test activities and technical evaluations, in support of NAVSEA's systems development mission, often occur with fleet activities within the Study Area. Tests within this category include, but are not limited to, anti-surface, anti-submarine, and mine warfare, using torpedoes, sonobuoys, and mine detection and neutralization systems.

Office of Naval Research (ONR) and Naval Research Laboratory (NLR) Testing

As the Navy's Science and Technology provider, ONR and NRL provide technology solutions for Navy and Marine Corps needs. ONR's mission, defined by law, is to plan, foster, and encourage scientific research in recognition of its paramount importance as related to the maintenance of future naval power, and the preservation of national security. Further, ONR manages the Navy's basic, applied, and advanced research to foster transition from science and technology to higher levels of research, development, test and evaluation. The Ocean Battlespace Sensing Department explores science and technology in the areas of oceanographic and meteorological observations, modeling, and prediction in the battlespace environment; submarine detection and classification (anti-submarine warfare); and mine warfare applications for detecting and neutralizing mines in both the ocean and littoral environments. ONR events include: Research, development, test and evaluation activities; surface processes acoustic communications experiments; shallow water acoustic propagation experiments; and long range acoustic propagation experiments.

Sonar, Ordnance, Targets, and Other Systems

The Navy uses a variety of sensors, platforms, weapons, and other devices to meet its mission. Training and testing with these systems may introduce acoustic (sound) energy into the environment. This section describes and organizes sonar systems, ordnance, munitions, targets, and other systems to facilitate understanding of the activities in which these systems are used. Underwater sound is described as one of two types for the purposes of the Navy's application: Impulsive and non-impulsive. Underwater detonations of explosives and other percussive events are impulsive sounds. Sonar and similar sound producing systems are categorized as non-impulsive sound sources.

Sonar and Other Non-Impulsive Sources

Modern sonar technology includes a variety of sonar sensor and processing systems. The simplest active sonar emits sound waves, or “pings,” sent out in multiple directions and the sound waves then reflect off of the target object in multiple directions. The sonar source calculates the time it takes for the reflected sound waves to return; this calculation determines the distance to the target object. More sophisticated active sonar systems emit a ping and then rapidly scan or listen to the sound waves in a specific area. This provides both distance to the target and directional information. Even more advanced sonar systems use multiple receivers to listen to echoes from several directions simultaneously and provide efficient detection of both direction and distance. The Navy rarely uses active sonar continuously throughout activities. When sonar is in use, the pings occur at intervals, referred to as a duty cycle, and the signals themselves

are very short in duration. For example, sonar that emits a 1-second ping every 10 seconds has a 10 percent duty cycle. The Navy utilizes sonar systems and other acoustic sensors in support of a variety of mission requirements. Primary uses include the detection of, and defense against, submarines (anti-submarine warfare) and mines (mine warfare); safe navigation and effective communications; use of unmanned undersea vehicles; and oceanographic surveys.

Ordnance and Munitions

Most ordnance and munitions used during training and testing events fall into three basic categories: projectiles (such as gun rounds), missiles (including rockets), and bombs. Ordnance can be further defined by their net explosive weight, which considers the type and quantity of the explosive substance without the packaging, casings, bullets, etc. Net explosive weight (NEW) is the trinitrotoluene (TNT) equivalent of energetic material, which is the standard measure of strength of bombs and other explosives. For example, a 5-inch shell fired from a Navy gun is analyzed at about 9.5 pounds (lb) (4.3 kg) of NEW. The Navy also uses non-explosive ordnance in place of high explosive ordnance in many training and testing events. Non-explosive ordnance munitions look and perform similarly to high explosive ordnance, but lack the main explosive charge.

Defense Countermeasures

Naval forces depend on effective defensive countermeasures to protect themselves against missile and torpedo attack. Defensive countermeasures are devices designed to confuse, distract, and confound precision guided munitions. Defensive countermeasures analyzed in this LOA application include acoustic countermeasures, which are used by surface ships and submarines to defend against torpedo attack. Acoustic countermeasures are either released from ships and submarines, or towed at a distance behind the ship.

Mine Warfare Systems

The Navy divides mine warfare systems into two categories: Mine detection and mine neutralization. Mine detection systems are used to locate, classify, and map suspected mines, on the surface, in the water column, or on the sea floor. The Navy analyzed the following mine detection systems for potential impacts on marine mammals:

• Towed or hull-mounted mine detection systems. These detection systems use acoustic and laser or video sensors to locate and classify suspect mines. Fixed and rotary wing platforms, ships, and unmanned vehicles are used for towed systems, which can rapidly assess large areas.

• Unmanned/remotely operated vehicles. These vehicles use acoustic and video or lasers to locate and classify mines and provide unique capabilities in nearshore littoral areas, surf zones, ports, and channels.

Mine Neutralization Systems

Mine neutralization systems disrupt, disable, or detonate mines to clear ports and shipping lanes, as well as littoral, surf, and beach areas in support of naval amphibious operations. The Navy analyzed the following mine neutralization systems for potential impacts to marine mammals:

• Towed influence mine sweep systems. These systems use towed equipment that mimic a particular ship's magnetic and acoustic signature triggering the mine and causing it to explode.

• Unmanned/remotely operated mine neutralization systems. Surface ships and helicopters operate these systems, which place explosive charges near or directly against mines to destroy the mine.

• Airborne projectile-based mine clearance systems. These systems neutralize mines by firing a small or medium-caliber non-explosive, supercavitating projectile from a hovering helicopter.

• Diver emplaced explosive charges. Operating from small craft, divers put explosive charges near or on mines to destroy the mine or disrupt its ability to function.

Classification of Non-Impulsive and Impulsive Sources Analyzed

In order to better organize and facilitate the analysis of about 300 sources of underwater non-impulsive sound or impulsive energy, the Navy developed a series of source classifications, or source bins. This method of analysis provides the following benefits:

• Allows for new sources to be covered under existing authorizations, as long as those sources fall within the parameters of a “bin;”

• Simplifies the data collection and reporting requirements anticipated under the MMPA;

• Ensures a conservative approach to all impact analysis because all sources in a single bin are modeled as the most powerful source (e.g., lowest frequency, highest source level, longest duty cycle, or largest net explosive weight within that bin);

• Allows analysis to be conducted more efficiently, without compromising the results;

• Provides a framework to support the reallocation of source usage (hours/explosives) between different source bins, as long as the total number of marine mammal takes remain within the overall analyzed and authorized limits. This flexibility is required to support evolving Navy training and testing requirements, which are linked to real world events.

A description of each source classification is provided in Tables 1-3. Non-impulsive sources are grouped into bins based on the frequency, source level when warranted, and how the source would be used. Impulsive bins are based on the net explosive weight of the munitions or explosive devices. The following factors further describe how non-impulsive sources are divided:

• Frequency of the non-impulsive source:

○ Low-frequency sources operate below 1 kilohertz (kHz)

○ Mid-frequency sources operate at and above 1 kHz, up to and including 10 kHz

○ High-frequency sources operate above 10 kHz, up to and including 100 kHz

○ Very high-frequency sources operate above 100 kHz, but below 200 kHz

• Source level of the non-impulsive source:

○ Greater than 160 decibels (dB), but less than 180 dB

○ Equal to 180 dB and up to 200 dB

○ Greater than 200 dB

How a sensor is used determines how the sensor's acoustic emissions are analyzed. Factors to consider include pulse length (time source is “on”); beam pattern (whether sound is emitted as a narrow, focused beam, or, as with most explosives, in all directions); and duty cycle (how often a transmission occurs in a given time period during an event).

There are also non-impulsive sources with characteristics that are not anticipated to result in takes of marine mammals. These sources have low source levels, narrow beam widths, downward directed transmission, short pulse lengths, frequencies beyond known hearing ranges of marine mammals, or some combination of these factors. These sources were not modeled by the Navy, but are qualitatively analyzed in Table 1-5 of the LOA application and Table 2.3.3 of the AFTT Draft EIS/OEIS.

Table 1—Explosive (Impulsive) Training and Testing Source Classes Analyzed

Source class

Representative munitions

Net Explosive weight (lbs)

E1

Medium-caliber projectiles

0.1-0.25

E2

Medium-caliber projectiles

0.26-0.5

E3

Large-caliber projectiles

>0.5-2.5

E4

Improved Extended Echo Ranging Sonobuoy

>2.5-5.0

E5

5 in. projectiles

>5-10

E6

15 lb. shaped charge

>10-20

E7

40 lb. demo block/shaped charge

>20-60

E8

250 lb. bomb

>60-100

E9

500 lb. bomb

>100-250

E10

1,000 lb. bomb

>250-500

E11

650 lb. mine

>500-650

E12

2,000 lb. bomb

>650-1,000

E13

1,200 lb. HBX charge

>1,000-1,740

E14

2,500 lb HBX charge

>1,740-3,625

E15

5,000 lb HBX charge

>3,625-7,250

Table 2—Active Acoustic (Non-Impulsive) Source Classes Analyzed

Source class category

Source class

Description

Low-Frequency (LF): Sources that produce low-frequency (less than 1 kHz) signals

LF3

Low-frequency sources greater than 200 dB.

LF4

Low-frequency sources equal to 180 dB and up to 200 dB.

LF5

Low-frequency sources greater than 160 dB, but less than 180 dB.

Mid-Frequency (MF): Tactical and non-tactical sources that produce mid-frequency (1 to 10 kHz) signals

MF1

Hull-mounted surface ship sonar (e.g., AN/SQS-53C and AN/SQS-60).

MF1K

Kingfisher mode associated with MF1 sonar.

MF2

Hull-mounted surface ship sonar (e.g., AN/SQS-56).

MF2K

Kingfisher mode associated with MF2 sonar.

MF3

Hull-mounted submarine sonar (e.g., AN/BQQ-10).

MF4

Helicopter-deployed dipping sonar (e.g., AN/AQS-22 and AN/AQS-13).

MF5

Active acoustic sonobuoys (e.g., DICASS).

MF6

Active sound underwater signal devices (e.g., MK-84).

MF8

Active sources (greater than 200 dB) not otherwise binned.

MF9

Active sources (equal to 180 dB and up to 200 dB) not otherwise binned.

MF10

Active sources (greater than 160 dB, but less than 180 dB) not otherwise binned.

MF11

Hull-mounted surface ship sonar with an active duty cycle greater than 80%.

MF12

Towed array surface ship sonar with an active duty cycle greater than 80%

High-Frequency (HF): Tactical and non-tactical sources that produce high-frequency (greater than 10 kHz but less than 180 kHz) signals

HF1

Hull-mounted submarine sonar (e.g., AN/BQQ-10).

HF2

High-Frequency Marine Mammal Monitoring System.

HF3

Other hull-mounted submarine sonar (classified).

HF4

Mine detection and classification sonar (e.g., Airborne Towed Minehunting Sonar System).

HF5

Active sources (greater than 200 dB) not otherwise binned.

HF6

Active sources (equal to 180 dB and up to 200 dB) not otherwise binned.

HF7

Active sources (greater than 160 dB, but less than 180 dB) not otherwise binned.

HF8

Hull-mounted surface ship sonar (e.g., AN/SQS-61).

Anti-Submarine Warfare (ASW): Tactical sources such as active sonobuoys and acoustic countermeasures systems used during the conduct of anti-submarine warfare training and testing activities

ASW1

Mid-frequency Deep Water Active Distributed System (DWADS).

ASW2

Mid-frequency Multistatic Active Coherent sonobuoy (e.g., AN/SSQ-125)—Sources that are analyzed by item.

ASW2

Mid-frequency Multistatic Active Coherent sonobuoy (e.g., AN/SSQ-125)—Sources that are analyzed by hours.

ASW3

Mid-frequency towed active acoustic countermeasure systems (e.g., AN/SLQ-25).

ASW4

Mid-frequency expendable active acoustic device countermeasures (e.g., MK-3).

Torpedoes (TORP): Source classes associated with the active acoustic signals produced by torpedoes

TORP1

Lightweight torpedo (e.g., MK-46, MK-54, or Anti-Torpedo Torpedo).

TORP2

Heavyweight torpedo (e.g., MK-48).

Doppler Sonars (DS): Sonars that use the Doppler effect to aid in navigation or collect oceanographic information

DS1

Low-frequency Doppler sonar (e.g., Webb Tomography Source).

Forward Looking Sonar (FLS): Forward or upward looking object avoidance sonars

FLS2-FLS3

High-frequency sources with short pulse lengths, narrow beam widths, and focused beam patterns used for navigation and safety of ships.

Acoustic Modems (M): Systems used to transmit data acoustically through the water

M3

Mid-frequency acoustic modems (greater than 190 dB).

Swimmer Detection Sonars (SD): Systems used to detect divers and submerged swimmers

SD1-SD2

High-frequency sources with short pulse lengths, used for detection of swimmers and other objects for the purposes of port security.

Synthetic Aperture Sonars (SAS): Sonars in which active acoustic signals are post-processed to form high-resolution images of the seafloor

SAS1

SAS2

SAS3

MF SAS systems.

HF SAS systems.

VHF SAS systems.

Table 3—Explosive Source Classes Analyzed for Non-Annual Training and Testing Activities

Source class

Representative munitions

Net explosive weight

1

(lbs)

E1

Medium-caliber projectiles

0.1-0.25

E2

Medium-caliber projectiles

0.26-0.5

E4

Improved Extended Echo Ranging Sonobuoy

2.6-5

E16

10,000 lb. HBX charge

7,251-14,500

E17

40,000 lb. HBX charge

14,501-58,000

Table 4—Active Acoustic (Non-Impulsive) Sources Analyzed for Non-Annual Training and Testing

Source class category

Source class

Description

Low-Frequency (LF): Sources that produce low-frequency (less than 1 kHz) signals

LF5

Low-frequency sources greater than 160 dB, but less than 180 dB.

Mid-Frequency (MF): Tactical and non-tactical sources that produce mid-frequency (1 to 10 kHz) signals

MF9

Active sources (equal to 180 dB and up to 200 dB) not otherwise binned.

High-Frequency (HF): Tactical and non-tactical sources that produce high-frequency (greater than 10 kHz but less than 180 kHz) signals

HF4

Mine detection and classification sonar (e.g., AN/AQS-20).

HF5

Active sources (greater than 200 dB) not otherwise binned.

HF6

Active sources (equal to 180 dB and up to 200 dB) not otherwise binned.

HF7

Active sources (greater than 160 dB, but less than 180 dB) not otherwise binned.

Forward Looking Sonar (FLS): Forward or upward looking object avoidance sonars

FLS2-FLS3

High-frequency sources with short pulse lengths, narrow beam widths, and focused beam patterns used for navigation and safety of ships.

Sonars (SAS): Sonars in which active acoustic signals are post-processed to form high-resolution images of the seafloor

SAS2

HF SAS systems.

Proposed Action

The Navy proposes to continue conducting training and testing activities within the AFTT Study Area. The Navy has been conducting similar military readiness training and testing activities in the AFTT Study Area since the 1940s. Recently, these activities were analyzed in separate EISs completed between 2009 and 2011. These documents, among others, and their associated MMPA regulations and authorizations, describe the baseline of training and testing activities currently conducted in the AFTT Study Area.

To meet all future training and testing requirements, the Navy has prepared the AFTT DEIS/OEIS to analyze changes to these activities due to fluctuations in the tempo and types of training and testing activities due to changing requirements; the introduction of new technologies; the dynamic nature of

international events; advances in warfighting doctrine and procedures; and changes in basing locations for ships, aircraft, and personnel (force structure changes). Such developments have influenced the frequency, duration, intensity, and location of required training and testing. In addition, the Study Area has expanded beyond the areas included in previous NMFS authorizations. The expansion of the Study Area does not represent an increase in areas where the Navy will train and test, but is merely an expansion of the area to be included in the proposed incidental take authorization.

Training

The Navy proposes to conduct training activities in the AFTT Study Area as described in Table 5 of this proposed rule. Detailed information about each proposed activity (stressor, training event, description, sound source, duration, and geographic location) can be found in Appendix A of the AFTT DEIS/OEIS. The Navy's proposed action is an adjustment to existing baseline training activities to accommodate the following:

• Force structure changes including the relocation of ships, aircraft, and personnel to meet Navy needs. As forces are moved within the existing Navy structure, training needs will necessarily change as the location of forces change.

• Development and introduction of new ships, aircraft, and new weapons systems;

• Current training activities that were not addressed in previous documents.

Table 5—Training Activities Within the Study Area

Stressor

Training event

Description

Source class

Number of

events per

year

Anti-Submarine Warfare (ASW)

Non-Impulsive

Tracking Exercise/Torpedo Exercise—Submarine (TRACKEX/TORPEX—Sub)

Submarine crews search, track, and detect submarines. Exercise torpedoes may be used during this event

ASW4; MF3; HF1; TORP2

102

Non-Impulsive

Tracking Exercise/Torpedo Exercise—Surface (TRACKEX/TORPEX—Surface)

Surface ship crews search, track and detect submarines. Exercise torpedoes may be used during this event

ASW1,3,4; MF1,2,3,4,5,11,12; HF1; TORP1

764

Non-Impulsive

Tracking Exercise/Torpedo Exercise—Helicopter (TRACKEX/TORPEX—Helo)

Helicopter crews search, detect and track submarines. Recoverable air launched torpedoes may be employed against submarine targets

ASW4; MF4,5; TORP1

432

Non-Impulsive

Tracking Exercise/Torpedo Exercise—Maritime Patrol Aircraft (TRACKEX/TORPEX—MPA)

Maritime patrol aircraft crews search, detect, and track submarines. Recoverable air launched torpedoes may be employed against submarine targets

MF5; TORP1

752

Non-Impulsive

Tracking Exercise—Maritime Patrol Aircraft Extended Echo Ranging Sonobuoy (TRACKEX—MPA sonobuoy)

Maritime patrol aircraft crews search, detect, and track submarines with extended echo ranging sonobuoys. Recoverable air launched torpedoes may be employed against submarine targets

ASW2

160

Non-Impulsive

Anti-Submarine Warfare Tactical Development Exercise

Multiple ships, aircraft and submarines coordinate their efforts to search, detect and track submarines with the use of all sensors. Anti-Submarine Warfare Tactical Development Exercise is a dedicated ASW event

ASW3,4; HF1; MF1,2,3,4,5

4

Non-Impulsive

Integrated Anti-Submarine Warfare Course (IAC)

Multiple ships, aircraft, and submarines coordinate the use of their sensors, including sonobuoys, to search, detect and track threat submarines. IAC is an intermediate level training event and can occur in conjunction with other major exercises

ASW 3,4; HF1; MF1,2,3,4,5

5

Non-Impulsive

Group Sail

Multiple ships and helicopters integrate the use of sensors, including sonobuoys, to search, detect and track a threat submarine. Group sails are not dedicated ASW events and involve multiple warfare areas

ASW 2,3; HF1; MF1,2,3,4,5

20

Non-Impulsive

ASW for Composite Training Unit Exercise (COMPTUEX)

Anti-Submarine Warfare activities conducted during a COMPTUEX

ASW 2,3,4; HF1; MF1,2,3,4,5,12

5

Non-Impulsive

ASW for Joint Task Force Exercise (JTFEX)/Sustainment Exercise (SUSTAINEX)

Anti-Submarine Warfare activities conducted during a JTFEX/SUSTAINEX

ASW2,3,4; HF1; MF1,2,3,4,5,12

4

Mine Warfare (MIW)

Non-Impulsive

Mine Countermeasures Exercise (MCM)—Ship Sonar

Littoral combat ship crews detect and avoid mines while navigating restricted areas or channels using active sonar

HF4

116

Non-Impulsive

Mine Countermeasures—Mine Detection

Ship crews and helicopter aircrews detect mines using towed and laser mine detection systems (e.g., AN/AQS-20, ALMDS)

HF4

2,538

Non-Impulsive

Coordinated Unit Level Helicopter Airborne Mine Countermeasure Exercises

Helicopters aircrew members train as a squadron in the use of airborne mine countermeasures, such as towed mine detection and neutralization systems

HF4

8

Non-Impulsive

Civilian Port Defense

Maritime security operations for military and civilian ports and harbors. Marine mammal systems may be used during the exercise

HF4

1 event every other year.

Other Training Activities

Non-Impulsive

Submarine Navigational (SUB NAV)

Submarine crews locate underwater objects and ships while transiting in and out of port

HF1; MF3

282

Non-Impulsive

Submarine Navigation Under Ice Certification

Submarine crews train to operate under ice. During training and certification other submarines and ships simulate ice

HF1

24

Non-Impulsive

Surface Ship Object Detection

Surface ship crews locate underwater objects that may impede transit in and out of port

MF1K; MF2K

144

Non-Impulsive

Surface Ship Sonar Maintenance

Pierside and at-sea maintenance of sonar systems

MF1,2

824

Non-Impulsive

Submarine Sonar Maintenance

Pierside and at-sea maintenance of sonar systems

MF3

220

Amphibious Warfare (AMW)

Impulsive

Naval Surface Fire Support Exercise—At Sea (FIREX [At Sea])

Surface ship crews use large-caliber guns to support forces ashore; however, the land target is simulated at sea. Rounds impact the water and are scored by passive acoustic hydrophones located at or near the target area

E5

50

Anti-Surface Warfare (ASUW)

Impulsive

Maritime Security Operations (MSO)—Anti-swimmer Grenades

Helicopter and surface ship crews conduct a suite of Maritime Security Operations (e.g., Visit, Board, Search, and Seizure; Maritime Interdiction Operations; Force Protection; and Anti-Piracy Operation)

E2

12

Impulsive

Gunnery Exercise (Surface-to-Surface) (Ship)—Medium-Caliber (GUNEX [S-S]—Ship)

Ship crews engage surface targets with ship's medium-caliber guns

E1; E2

827

Impulsive

Gunnery Exercise (Surface-to-Surface) (Ship)—Large-Caliber (GUNEX [S-S]—Ship)

Ship crews engage surface targets with ship's large-caliber guns

E3; E5

294

Impulsive

Gunnery Exercise (Surface-to-Surface) (Boat) (GUNEX [S-S]—Boat)

Small boat crews engage surface targets with small and medium-caliber guns

E1; E2

434

Impulsive

Missile Exercise (Surface-to-Surface) (MISSILEX [S-S])

Surface ship crews defend against threat missiles and other surface ships with missiles

E10

20

Impulsive

Gunnery Exercise (Air-to-Surface) (GUNEX [A-S])

Fixed-wing and helicopter aircrews, including embarked personnel, use small and medium-caliber guns to engage surface targets

E1; E2

715

Impulsive

Missile Exercise (Air-to-Surface)—Rocket (MISSILEX [A-S])

Fixed-wing and helicopter aircrews fire both precision-guided missiles and unguided rockets against surface targets

E5

210

Impulsive

Missile Exercise (Air-to-Surface) (MISSILEX [A-S])

Fixed-wing and helicopter aircrews fire both precision-guided missiles and unguided rockets against surface targets

E6; E8

248

Impulsive

Bombing Exercise (Air-to-Surface) (BOMBEX [A-S])

Fixed-wing aircrews deliver bombs against surface targets

E8; E9; E10; E12

930

Impulsive

Sinking Exercise (SINKEX)

Aircraft, ship, and submarine crews deliver ordnance on a seaborne target, usually a deactivated ship, which is deliberately sunk using multiple weapon systems

E3; E5; E8; E9; E10;E11;E12

1

Anti-Submarine Warfare (ASW)

Impulsive

Tracking Exercise—Maritime Patrol Aircraft Extended Echo Ranging Sonobuoy (TRACKEX—MPA sonobuoy)

Maritime patrol aircraft crews search, detect, and track submarines with extended echo ranging sonobuoys. Recoverable air launched torpedoes may be employed against submarine targets.

E4

160

Impulsive

Group Sail

Multiple ships and helicopters integrate the use of sensors, including sonobuoys, to search, detect and track a threat submarine. Group sails are not dedicated ASW events and involve multiple warfare areas

E4

20

Impulsive

ASW for Composite Training Unit Exercise (COMPTUEX)

Anti-Submarine Warfare activities conducted during a COMPTUEX

E4

4

Impulsive

ASW for Joint Task Force Exercise (JTFEX)/Sustainment Exercise (SUSTAINEX)

Anti-Submarine Warfare activities conducted during a JTFEX/SUSTAINEX

E4

4

Mine Warfare (MIW)

Impulsive

Explosive Ordnance Disposal (EOD)/Mine Neutralization

Personnel disable threat mines. Explosive charges may be used

E1; E4; E5; E6; E7; E8

618

Impulsive

Mine Countermeasures—Mine Neutralization—Remotely Operated Vehicles

Ship crews and helicopter aircrews disable mines using remotely operated underwater vehicles

E4

508

Impulsive

Civilian Port Defense

Maritime security operations for military and civilian ports and harbors. Marine mammal systems may be used during the exercise

E2; E4

1 event every other year.

Pile Driving and Pile Removal

Impulsive

Elevated Causeway System (ELCAS)

A temporary pier is constructed off the beach. Supporting pilings are driven into the sand and then later removed. The Elevated Causeway System is a portion of a larger activity Joint Logistics Over the Shore (JLOTS) which is covered under separate documentation. Construction would involve intermittent impact pile driving of 24-inch, uncapped, steel pipe piles over approximately 2 weeks. Crews work 24 hours a day and can drive approximately 8 piles in that period. Each pile takes about 10 minutes to drive. When training events that use the elevated causeway system are complete, the piles would be removed using vibratory methods over approximately 6 days. Crews can remove about 14 piles per 24-hour period, each taking about 6 minutes to remove

1

Testing

The Navy's proposed testing activities are described in Tables 6 and 7. Detailed information about each proposed activity (stressor, testing event, description, sound source, duration, and geographic location) can be found in Appendix A of the AFTT DEIS/OEIS. NMFS used the detailed information in Appendix A of the AFTT DEIS/OEIS to analyze the potential impacts on marine mammals; however, the Navy's proposed action is summarized in the Tables based on the type of sound source.

Table 6—Naval Air Systems Command Testing Activities Within the Study Area

Stressor

Testing event

Description

Source class

Number of

events per

year

Anti-Submarine Warfare (ASW)

Non-Impulsive

Anti-Submarine Warfare Torpedo Test

This event is similar to the training event Torpedo Exercise. The test evaluates anti-submarine warfare systems onboard rotary wing and fixed wing aircraft and the ability to search for, detect, classify, localize, and track a submarine or similar target

TORP1

242

Non-Impulsive

Kilo Dip

A kilo dip is the operational term used to describe a functional check of a helicopter deployed dipping sonar system. The sonar system is briefly activated to ensure all systems are functional. A kilo dip is simply a precursor to more comprehensive testing

MF4

43

Non-Impulsive

Sonobuoy Lot Acceptance Test

Sonobuoys are deployed from surface vessels and aircraft to verify the integrity and performance of a lot, or group, of sonobuoys in advance of delivery to the Fleet for operational use

ASW2; MF5,6

39

Non-Impulsive

ASW Tracking Test—Helicopter

This event is similar to the training event anti-submarine warfare Tracking Exercise—Helicopter. The test evaluates the sensors and systems used to detect and track submarines and to ensure that helicopter systems used to deploy the tracking systems perform to specifications

MF4,5

428

Non-Impulsive

ASW Tracking Test—Maritime Patrol Aircraft

This event is similar to the training event anti-submarine warfare Tracking Exercise—Maritime Patrol Aircraft. The test evaluates the sensors and systems used by maritime patrol aircraft to detect and track submarines and to ensure that aircraft systems used to deploy the tracking systems perform to specifications and meet operational requirements

ASW2; MF5,6

75

Mine Warfare (MIW)

Non-Impulsive

Airborne Towed Minehunting Sonar System Test

Tests of the Airborne Towed Minehunting Sonar System to evaluate the search capabilities of this towed, mine hunting, detection, and classification system. The sonar on the Airborne Towed Minehunting Sonar System identifies mine-like objects in the deeper parts of the water column

HF4

155

Anti-Surface Warfare (ASUW)

Impulsive

Air to Surface Missile Test

This event is similar to the training event Missile Exercise Air to Surface. Test may involve both fixed wing and rotary wing aircraft launching missiles at surface maritime targets to evaluate the weapons system or as part of another systems integration test

E6; E10

239

Impulsive

Air to Surface Gunnery Test

This event is similar to the training event Gunnery Exercise Air to Surface. Strike fighter and helicopter aircrews evaluate new or enhanced aircraft guns against surface maritime targets to test that the gun, gun ammunition, or associated systems meet required specifications or to train aircrew in the operation of a new or enhanced weapons system

E1

165

Impulsive

Rocket Test

Rocket testing evaluates the integration, accuracy, performance, and safe separation of laser-guided and unguided 2.75-in rockets fired from a hovering or forward flying helicopter or from a fixed wing strike aircraft

E5

332

Anti-Submarine Warfare (ASW)

Impulsive

Sonobuoy Lot Acceptance Test

Sonobuoys are deployed from surface vessels and aircraft to verify the integrity and performance of a lot, or group, of sonobuoys in advance of delivery to the Fleet for operational use

E3; E4

39

Impulsive

ASW Tracking Test—Helicopter

This event is similar to the training event anti-submarine warfare Tracking Exercise—Helicopter. The test evaluates the sensors and systems used to detect and track submarines and to ensure that helicopter systems used to deploy the tracking systems perform to specifications

E3

428

Impulsive

ASW Tracking Test—Maritime Patrol Aircraft

This event is similar to the training event anti-submarine warfare Tracking Exercise—Maritime Patrol Aircraft. The test evaluates the sensors and systems used by maritime patrol aircraft to detect and track submarines and to ensure that aircraft systems used to deploy the tracking systems perform to specifications and meet operational requirements

E3; E4

75

Mine Warfare (MIW)

Impulsive

Airborne Mine Neutralization System Test

Airborne mine neutralization tests evaluate the system's ability to detect and destroy mines. The Airborne Mine Neutralization System Test uses up to four unmanned underwater vehicles equipped with HF sonar, video cameras, and explosive neutralizers

E4; E11

165

Impulsive

Airborne Projectile-based Mine Clearance System

An MH-60S helicopter uses a laser-based detection system to search for mines and to fix mine locations for neutralization with an airborne projectile-based mine clearance system. The system neutralizes mines by firing a small or medium-caliber inert, supercavitating projectile from a hovering helicopter

E11

237

Impulsive

Airborne Towed Minesweeping Test

Tests of the Airborne Towed Minesweeping System would be conducted by a MH-60S helicopter to evaluate the functionality of the system and the MH-60S at sea. The system is towed from a forward flying helicopter and works by emitting an electromagnetic field and mechanically generated underwater sound to simulate the presence of a ship. The sound and electromagnetic signature cause nearby mines to explode

E11

72

Table 7—Naval Sea Systems Command Testing Activities Within the Study Area

Stressor

Testing event

Description

Source class

Number of events per year

New Ship Construction

Non-Impulsive

Surface Combatant Sea Trials—Pierside Sonar Testing

Tests ship's sonar systems pierside to ensure proper operation

MF1,9,10; MF1K

12.

Non-Impulsive

Surface Combatant Sea Trials—Anti-Submarine Warfare Testing

Ships demonstrate capability of countermeasure systems and underwater surveillance and communications systems

ASW3; MF 1,9,10; MF1K

10.

Non-Impulsive

Submarine Sea Trials—Pierside Sonar Testing

Tests ship's sonar systems pierside to ensure proper operation

M3; HF1; MF3,10

6

Non-Impulsive

Submarine Sea Trials—Anti-Submarine Warfare Testing

Submarines demonstrate capability of underwater surveillance and communications systems

M3; HF1; MF3,10

12.

Non-Impulsive

Anti-submarine Warfare Mission Package Testing

Ships and their supporting platforms (e.g., helicopters, unmanned aerial vehicles) detect, localize, and prosecute submarines

ASW1,3; MF4,5,12; TORP1

24.

Non-Impulsive

Mine Countermeasure Mission Package Testing

Ships conduct mine countermeasure operations

HF4

8.

Life Cycle Activities

Non-Impulsive

Surface Ship Sonar Testing/Maintenance

Pierside and at-sea testing of ship systems occurs periodically following major maintenance periods and for routine maintenance

ASW3; MF1, 9,10; MF1K

16.

Non-Impulsive

Submarine Sonar Testing/Maintenance

Pierside and at-sea testing of submarine systems occurs periodically following major maintenance periods and for routine maintenance

HF1,3; M3; MF3

28.

Non-Impulsive

Combat System Ship Qualification Trial (CSSQT)—In-port Maintenance Period

All combat systems are tested to ensure they are functioning in a technically acceptable manner and are operationally ready to support at-sea CSSQT events

MF1

12.

Non-Impulsive

Combat System Ship Qualification Trial (CSSQT)—Undersea Warfare (USW)

Tests ships ability to track and defend against undersea targets

HF4; MF1,2,4,5; TORP1

9.

NAVSEA Range Activities

Naval Surface Warfare Center, Panama City Division (NSWC PCD)

Non-Impulsive

Unmanned Underwater Vehicles Demonstration

Testing and demonstrations of multiple Unmanned Underwater Vehicles and associated acoustic, optical, and magnetic systems

HF5,6,7; LF5; FLS2; MF9; SAS2

1 per 5 year period.

Non-Impulsive

Mine Detection and Classification Testing

Air, surface, and subsurface vessels detect and classify mines and mine-like objects

HF1,4; MF1K; SAS2

81.

Non-Impulsive

Stationary Source Testing

Stationary equipment (including swimmer defense systems) is deployed to determine functionality

LF4; MF8; SD1,2

11.

Non-Impulsive

Special Warfare Testing

Testing of submersibles capable of inserting and extracting personnel and/or payloads into denied areas from strategic distances

MF9

110.

Non-Impulsive

Unmanned Underwater Vehicle Testing

Unmanned Underwater Vehicles are deployed to evaluate hydrodynamic parameters, to full mission, multiple vehicle functionality assessments

FLS2; HF 5,6,7; LF5; MF9; SAS2

88.

Naval Undersea Warfare Center Division, Newport (NUWCDIVNPT)

Non-Impulsive

Torpedo Testing

Non-explosive torpedoes are launched to record operational data. All torpedoes are recovered

TORP1; TORP2

30.

Non-Impulsive

Towed Equipment Testing

Surface vessel or Unmanned Underwater Vehicle deploys equipment to determine functionality of towed systems

LF4; MF9; SAS1

33.

Non-Impulsive

Unmanned Underwater Vehicle Testing

Unmanned Underwater Vehicles are deployed to evaluate hydrodynamic parameters, to full mission, multiple vehicle functionality assessments

HF6,7; LF5; MF10; SAS2

123.

Non-Impulsive

Semi-Stationary Equipment Testing

Semi-stationary equipment (e.g., hydrophones) is deployed to determine functionality

ASW3,4; HF 5,6; LF 4,5; MF9,10

154.

Non-Impulsive

Unmanned Underwater Vehicle Demonstrations

Testing and demonstrations of multiple Unmanned Underwater Vehicles and associated acoustic, optical, and magnetic systems

FLS2; HF5,6,7; LF5; MF9; SAS2

1 per 5 year period.

Non-Impulsive

Pierside Integrated Swimmer Defense Testing

Swimmer defense testing ensures that systems can effectively detect, characterize, verify, and defend against swimmer/diver threats in harbor environments

LF4; MF8; SD1

6.

South Florida Ocean Measurement Facility (SFOMF)

Non-Impulsive

Signature Analysis Activities

Testing of electromagnetic, acoustic, optical, and radar signature measurements of surface ship and submarine

ASW2; HF1,6; LF4; M3; MF9

18.

Non-Impulsive

Mine Testing

Air, surface, and sub-surface systems detect, counter, and neutralize ocean-deployed mines

HF4

33.

Non-Impulsive

Surface Testing

Various surface vessels, moored equipment and materials are testing to evaluate performance in the marine environment

FLS2; HF5,6,7; LF5; MF9; SAS2

33.

Non-Impulsive

Unmanned Underwater Vehicles Demonstrations

Testing and demonstrations of multiple Unmanned Underwater Vehicles and associated acoustic, optical, and magnetic systems

FLS2; HF5,6,7; LF5; MF9; SAS2

1 per 5 year period.

Additional Activities at Locations Outside of NAVSEA Ranges

Anti-Surface Warfare (ASUW)/Anti-Submarine Warfare (ASW) Testing

Non-Impulsive

Torpedo (Non-explosive) Testing

Air, surface, or submarine crews employ inert torpedoes against submarines or surface vessels. All torpedoes are recovered

ASW3,4; HF1; M3; MF1,3,4,5; TORP1,2

26.

Non-Impulsive

Torpedo (Explosive) Testing

Air, surface, or submarine crews employ explosive torpedoes against artificial targets or deactivated ships

TORP1; TORP2

2.

Non-Impulsive

Countermeasure Testing

Towed sonar arrays and anti-torpedo torpedo systems are employed to detect and neutralize incoming weapons

ASW3; HF5; TORP 1,2

3.

Non-Impulsive

Pierside Sonar Testing

Pierside testing to ensure systems are fully functional in a controlled pierside environment prior to at-sea test activities

ASW3; HF1,3; M3; MF1,3

23.

Non-Impulsive

At-sea Sonar Testing

At-sea testing to ensure systems are fully functional in an open ocean environment

ASW4; HF1; M3; MF3

15.

Mine Warfare (MIW) Testing

Non-Impulsive

Mine Detection and Classification Testing

Air, surface, and subsurface vessels detect and classify mines and mine-like objects

HF4

66.

Non-Impulsive

Mine Countermeasure/Neutralization Testing

Air, surface, and subsurface vessels neutralize threat mines that would otherwise restrict passage through an area

HF4; M3

14.

Shipboard Protection Systems and Swimmer Defense Testing

Non-Impulsive

Pierside Integrated Swimmer Defense Testing

Swimmer defense testing ensures that systems can effectively detect, characterize, verify, and defend against swimmer/diver threats in harbor environments

LF4; MF8; SD1

3.

Unmanned Vehicle Testing

Non-Impulsive

Unmanned Vehicle Development and Payload Testing

Vehicle development involves the production and upgrade of new unmanned platforms on which to attach various payloads used for different purposes

MF9; SAS2

111.

Other Testing Activities

Non-Impulsive

Special Warfare Testing

Special warfare includes testing of submersibles capable of inserting and extracting personnel and/or payloads into denied areas from strategic distances

HF1; M3; MF9

4.

Ship Construction and Maintenance

New Ship Construction

Impulsive

Aircraft Carrier Sea Trials—Gun Testing—Medium-Caliber

Medium-caliber gun systems are tested using non-explosive and explosive rounds

E1

410.

Impulsive

Surface Warfare Mission Package—Gun Testing- Medium Caliber

Ships defense against surface targets with medium-caliber guns

E1

5.

Impulsive

Surface Warfare Mission Package—Gun Testing- Large Caliber

Ships defense against surface targets with large-caliber guns

E3

5.

Impulsive

Surface Warfare Mission Package—Missile/Rocket Testing

Ships defense against surface targets with medium range missiles or rockets

E6

15.

Impulsive

Mine Countermeasure Mission Package Testing

Ships conduct mine countermeasure operations.

E4

8.

Ship Shock Trials

Impulsive

Aircraft Carrier Full Ship Shock Trial

Explosives are detonated underwater against surface ships

E17

1 per 5 year period.

Impulsive

DDG 1000 Zumwalt Class Destroyer Full Ship Shock Trial

Explosives are detonated underwater against surface ships

E16

1 per 5 year period.

Impulsive

Littoral Combat Ship Full Ship Shock Trial

Explosives are detonated underwater against surface ships

E16

2 per 5 year period.

NAVSEA Range Activities

Naval Surface Warfare Center, Panama City Division (NSWC PCD)

Impulsive

Mine Countermeasure/Neutralization Testing

Air, surface, and subsurface vessels neutralize threat mines and mine-like objects

E4

15.

Impulsive

Ordnance Testing

Airborne and surface crews defend against surface targets with small-, medium-, and large-caliber guns, as well as line charge testing

E5; E14

37.

Additional Activities at Locations Outside of NAVSEA Ranges

Anti-Surface Warfare (ASUW)/Anti-Submarine Warfare (ASW) Testing

Impulsive

Torpedo (Explosive) Testing

Air, surface, or submarine crews employ explosive torpedoes against artificial targets or deactivated ships

E8; E11

2.

Mine Warfare (MIW) Testing

Impulsive

Mine Countermeasure/Neutralization Testing

Air, surface, and subsurface vessels neutralize threat mines that would otherwise restrict passage through an area

E4; E8

14.

Other Testing Activities

Impulsive

At-Sea Explosives Testing

Explosives are detonated at sea

E5

4.

Vessels

Vessels used as part of the proposed action include ships, submarines, Unmanned Undersea Vehicles (UUVs), and boats ranging in size from small, 16 ft (5 m) Rigid Hull Inflatable Boats to 1,092-ft (333 m) long aircraft carriers. Representative Navy vessel types, lengths, and speeds used in both training and testing activities are shown in Table 5 of this proposed rule. While these speeds are representative, some vessels operate outside of these speeds due to unique training, testing, or safety requirements for a given event. Examples include increased speeds needed for flight operations, full speed runs to test engineering equipment, time critical positioning needs, etc. Examples of decreased speeds include speeds less than 5 knots or completely stopped for launching small boats, certain tactical maneuvers, target launch or retrievals, UUVs, etc.

The number of Navy vessels in the Study Area varies based on training and testing schedules. These activities could be widely dispersed throughout the Study Area, but would be more concentrated near naval ports, piers, and range areas. Activities involving vessel movements occur intermittently and are variable in duration, ranging from a few hours up to 2 weeks. Navy vessel traffic would especially be concentrated near Naval Station Norfolk in Norfolk, VA and Naval Station Mayport in Jacksonville, FL. Surface and sub-surface vessel operations in the Study Area may result in marine mammal strikes.

Table 8—Typical Navy Boat and Vessel Types With Length Greater Than 18 Meters Used Within the AFTT Study Area

Vessel Type

(>18 m)

Example(s) (specifications in meters (m) for length, metric tons (mt) for mass, and knots for speed)

Typical operating speed

(knots)

Aircraft Carrier

Aircraft Carrier (CVN)

10 to 15.

length: 333 m beam: 41 m draft: 12 m displacement: 81,284 mt max. speed: 30+ knots.

Surface Combatants

Cruiser (CG)

10 to 15.

length: 173 m beam: 17 m draft: 10 m displacement: 9,754 mt max. speed: 30+ knots.

Destroyer (DDG).

length: 155 m beam: 18 m draft: 9 m displacement: 9,648 mt max. speed: 30+ knots.

Frigate (FFG).

length: 136 m beam: 14 m draft: 7 m displacement: 4,166 mt max. speed: 30+ knots.

Littoral Combat Ship (LCS).

length: 115 m beam: 18 m draft: 4 m displacement: 3,000 mt max. speed: 40+ knots.

Amphibious Warfare Ships

Amphibious Assault Ship (LHA, LHD)

10 to 15.

length: 253 m beam: 32 m draft: 8 m displacement: 42,442 mt max. speed: 20+knots.

Amphibious Transport Dock (LPD).

length: 208 m beam: 32 m draft: 7 m displacement: 25,997 mt max. speed: 20+knots.

Dock Landing Ship (LSD).

length: 186 m beam: 26 m draft: 6 m displacement: 16,976 mt max. speed: 20+knots.

Mine Warship Ship

Mine Countermeasures Ship (MCM)

5 to 8.

length: 68 m beam: 12 m draft: 4 m displacement: 1,333 max. speed: 14 knots.

Submarines

Attack Submarine (SSN)

8 to 13.

length: 115 m beam: 12 m draft: 9 m displacement: 12,353 mt max. speed: 20+knots.

Guided Missile Submarine (SSGN).

length: 171 m beam: 13 m draft: 12 m displacement: 19,000 mt max. speed: 20+knots.

Combat Logistics Force Ships

Fast Combat Support Ship (T-AOE)

8 to 12.

length: 230 m beam: 33 m draft: 12 m displacement: 49,583 max. speed: 25 knots.

Dry Cargo/Ammunition Ship (T-AKE).

length: 210 m beam: 32 m draft: 9 m displacement: 41,658 mt max speed: 20 knots.

Fleet Replenishment Oilers (T-AO).

length: 206 m beam: 30 m draft: 11 m displacement: 42,674 mt max. speed: 20 knots.

Fleet Ocean Tugs (T-ATF).

length: 69 m beam: 13 m draft: 5 m displacement: 2,297 max. speed: 14 knots.

Support Craft/Other

Landing Craft, Utility (LCU)

3 to 5.

length: 41m beam: 9 m draft: 2 m displacement: 381 mt max. speed: 11 knots.

Landing Craft, Mechanized (LCM).

length: 23 m beam: 6 m draft: 1 m displacement: 107 mt max. speed: 11 knots.

Support Craft/Other Specialized High Speed

MK V Special Operations Craft

length: 25 m beam: 5 m displacement: 52 mt max. speed: 50 knots

Variable.

Duration and Location

Training and testing activities would be conducted in the AFTT Study Area throughout the year from January 2014 to January 2019. The AFTT Study Area is in the western Atlantic Ocean and encompasses the east coast of North America and the Gulf of Mexico. The Study Area has expanded slightly beyond the areas included in previous Navy authorizations. However, this expansion is not an increase in the Navy's training and testing area, but merely an increase in the area to be analyzed under an incidental take authorization in support of the AFTT EIS/OEIS. The Study Area includes several existing study areas, range complexes, and testing ranges: The Atlantic Fleet Active Sonar Training (AFAST) Study Area; Northeast Range Complexes; Naval Undersea Warfare Center Division, Newport (NUWCDIVNPT) Testing Range; Virginia Capes (VACAPES) Range Complex; Cherry Point (CHPT) Range Complex; Jacksonville (JAX) Range Complex; Naval Surface Warfare Center (NSWC) Carderock Division, South Florida Ocean Measurement Facility (SFOMF) Testing Range; Key West Range Complex; Gulf of Mexico (GOMEX); and Naval Surface Warfare Center, Panama City Division (NSWC PCD) Testing Range. In addition, the Study Area includes Narragansett Bay, the lower Chesapeake Bay and St. Andrew Bay for training and testing activities. Ports included for Civilian Port Defense training events include Earle, New Jersey; Groton, Connecticut; Norfolk, Virginia; Morehead City, North Carolina; Wilmington, North Carolina; Kings Bay, Georgia; Mayport, Florida; Beaumont, Texas; and Corpus Christi, Texas.

The Study Area includes pierside locations where Navy surface ship and submarine sonar maintenance and testing occur. Pierside locations include channels and transit routes in ports and facilities associated with ports and shipyards. These locations in the AFTT Study Area are located at the following Navy ports and naval shipyards:

• Portsmouth Naval Shipyard, Kittery, Maine;

• Naval Submarine Base New London, Groton, Connecticut;

• Naval Station Norfolk, Norfolk, Virginia;

• Joint Expeditionary Base Little Creek—Fort Story, Virginia Beach, Virginia;

• Norfolk Naval Shipyard, Portsmouth, Virginia;

• Naval Submarine Base Kings Bay, Kings Bay, Georgia;

• Naval Station Mayport, Jacksonville, Florida; and

• Port Canaveral, Cape Canaveral, Florida.

Navy-contractor shipyards in the following cities are also in the Study Area:

• Bath, Maine;

• Groton, Connecticut;

• Newport News, Virginia; and

• Pascagoula, Mississippi.

More detailed information is provided in the Navy's LOA application (

http://www.nmfs.noaa.gov/pr/permits/incidental.htm

).

Description of Marine Mammals in the Area of the Specified Activities

There are 48 marine mammal species with possible or known occurrence in the AFTT Study Area, 45 of which are managed by NMFS. As indicated in Table 9, there are 39 cetacean species (8 mysticetes and 31 odontocetes) and six pinnipeds. Seven marine mammal species are listed under the Endangered Species Act: Bowhead whale, North Atlantic right whale, humpback whale, sei whale, fin whale, blue whale, and sperm whale.

Table 9—Marine Mammal Occurrence Within the AFTT Study Area

Common name

Scientific name

1

ESA/MMPA

status

2

Stock

3

Stock

abundance

3

best (CV)/min

Occurrence in study area

4

Open ocean

Large marine

ecosystems

Bays, rivers, and

estuaries

Order Cetacea

Suborder Mysticeti (baleen whales)

Family Balaenidae (right whales)

North Atlantic right whale

Eubalaena glacialis

Endangered, Strategic, Depleted

Western North Atlantic

361 (0)/361

Gulf Stream, Labrador Current

Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Bowhead whale

Balaena mysticetus

Endangered, Strategic, Depleted

West Greenland

1,230

5

/490-2,940

Labrador Current

Newfoundland-Labrador Shelf, West Greenland Shelf.

Family Balaenopteridae (rorquals)

Humpback whale

Megaptera novaeangliae

Endangered, Strategic, Depleted

Gulf of Maine

847 (0.55)/549

Gulf Stream, North Atlantic Gyre, Labrador Current

Gulf of Mexico, Caribbean Sea, Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Minke whale

Balaenoptera acutorostrata

Canadian east coast

8,987 (0.32)/6,909

Gulf Stream, North Atlantic Gyre, Labrador Current

Caribbean Sea, Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Bryde's whale

Balaenoptera brydei/edeni

Gulf of Mexico Oceanic

15 (1.98)/5

Gulf Stream, North Atlantic Gyre

Gulf of Mexico, Caribbean Sea, Southeast U.S. Continental Shelf.

Sei whale

Balaenoptera borealis

Endangered, Strategic, Depleted

Nova Scotia

386 (0.85)/208

Gulf Stream, North Atlantic Gyre, Labrador Current

Gulf of Mexico, Caribbean Sea, Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Fin whale

Balaenoptera physalus

Endangered, Strategic, Depleted

Western North Atlantic

3,985 (0.24)/3,269

Gulf Stream, North Atlantic Gyre, Labrador Current

Caribbean Sea, Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Blue whale

Balaenoptera musculus

Endangered, Strategic, Depleted

Western North Atlantic

NA/440

6

Gulf Stream, North Atlantic Gyre, Labrador Current

Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Suborder Odontoceti (toothed whales)

Family Physeteridae (sperm whale)

Sperm whale

Physeter macrocephalus

Endangered, Strategic, Depleted

North Atlantic

4,804 (0.38)/3,539

Gulf Stream, North Atlantic Gyre, Labrador Current

Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Endangered, Strategic, Depleted

Gulf of Mexico Oceanic

1,665 (0.2)/1,409

Gulf of Mexico.

Endangered, Strategic, Depleted

Puerto Rico and U.S. Virgin Islands

unknown

North Atlantic Gyre

Caribbean Sea.

Family Kogiidae (sperm whales)

Pygmy sperm whale

Kogia breviceps

Strategic

Western North Atlantic

395 (0.4)/285

7

Gulf Stream, North Atlantic Gyre

Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Gulf of Mexico Oceanic

453(0.35)/340

7

Gulf of Mexico, Caribbean Sea.

Dwarf sperm whale

Kogia sima

Western North Atlantic

395 (0.4)/285

7

Gulf Stream, North Atlantic Gyre

Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf, Scotian Shelf.

Gulf of Mexico Oceanic

453(0.35)/340

7

Gulf of Mexico, Caribbean Sea

Family Monodontidae (beluga whale and narwhal)

Beluga whale

Delphinapterus leucas

NA8

NA

8

Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Narwhal

Monodon monoceros

NA9

NA

9

Newfoundland-Labrador Shelf, West Greenland Shelf.

Family Ziphiidae (beaked whales)

Cuvier's beaked whale

Ziphius cavirostris

Western North Atlantic

3,513 (0.63)/2,154

10

Gulf Stream, North Atlantic Gyre, Labrador Current

Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Gulf of Mexico Oceanic

65 (0.67)/39

Gulf of Mexico, Caribbean Sea.

True's beaked whale

Mesoplodon mirus

Western North Atlantic

3,513 (0.63)/2,154

10

Gulf Stream, North Atlantic Gyre, Labrador Current

Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Gervais' beaked whale

Mesoplodon europaeus

Western North Atlantic

3,513 (0.63)/2,154

10

Gulf Stream, North Atlantic Gyre

Southeast U.S. Continental Shelf, Northeast United States Continental Shelf.

Gulf of Mexico Oceanic

57 (1.4)/24

11

Gulf Stream, North Atlantic Gyre

Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf.

Sowerby's beaked whale

Mesoplodon bidens

Western North Atlantic

3,513 (0.63)/2,154

10

Gulf Stream, North Atlantic Gyre

Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Blainville's beaked whale

Mesoplodon densirostris

Western North Atlantic

3,513 (0.63)/2,154

10

Gulf Stream, North Atlantic Gyre, Labrador Current

Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Gulf of Mexico Oceanic

57 (1.4)/24

11

Gulf of Mexico, Caribbean Sea.

Northern bottlenose whale

Hyperoodon ampullatus

Western North Atlantic

Unknown

Gulf Stream, North Atlantic Gyre, Labrador Current

Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Family Delphinidae (dolphins)

Rough-toothed dolphin

Steno bredanensis

Western North Atlantic

Unknown

Gulf Stream, North Atlantic Gyre

Caribbean Sea, Southeast U.S. Continental Shelf.

Gulf of Mexico (Outer continental shelf and Oceanic)

Unknown

Gulf of Mexico, Caribbean Sea.

Bottlenose dolphin

Tursiops truncatus

Strategic, Depleted

Western North Atlantic, offshore

12

81,588 (0.17)/70,775

Gulf Stream, North Atlantic Gyre

Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf.

Strategic, Depleted

Western North Atlantic, coastal, northern migratory

9,604 (0.36)/7,147

Southeast U.S. Continental Shelf

Island Sound, Sandy Hook Bay, Lower Chesapeake Bay, James River, Elizabeth River.

Strategic, Depleted

Western North Atlantic, coastal, southern migratory

12,482 (0.32)/9,591

Southeast U.S. Continental Shelf

Lower Chesapeake Bay, James River, Elizabeth River, Beaufort Inlet, Cape Fear River, Kings Bay, St. Johns River.

Strategic, Depleted

Western North Atlantic, coastal, South Carolina/Georgia

7,738 (0.23)/6,399

Southeast U.S. Continental Shelf

Kings Bay, St. Johns River.

Strategic, Depleted

Western North Atlantic, coastal, Northern Florida

3,064 (0.24)/2,511

Southeast U.S. Continental Shelf

Kings Bay, St. Johns River.

Strategic

Western North Atlantic, coastal, Central Florida

6,318 (0.26)/5,094

Southeast U.S. Continental Shelf

Port Canaveral.

Strategic

Northern North Carolina Estuarine System

Unknown

Southeast U.S. Continental Shelf

Beaufort Inlet, Cape Fear River.

Strategic

Southern North Carolina Estuarine System

2,454 (0.53)/1,614

Southeast U.S. Continental Shelf

Beaufort Inlet, Cape Fear River.

Strategic

Charleston Estuarine System

Unknown

Southeast U.S. Continental Shelf.

Strategic

Northern Georgia/Southern South Carolina Estuarine System

Unknown

Southeast U.S. Continental Shelf.

Strategic

Southern Georgia Estuarine System

Unknown

Southeast U.S. Continental Shelf

Kings Bay, St. Johns River.

Strategic

Jacksonville Estuarine System

Unknown

Southeast U.S. Continental Shelf

Kings Bay, St. Johns River.

Strategic

Indian River Lagoon Estuarine System

Unknown

Southeast U.S. Continental Shelf

Port Canaveral.

Strategic

Biscayne Bay

Unknown

Southeast U.S. Continental Shelf.

Florida Bay

514 (0.17)/447

Gulf of Mexico.

Gulf of Mexico Continental Shelf

Unknown

Gulf of Mexico.

Gulf of Mexico, eastern coastal

7,702 (0.19)/6,551

Gulf of Mexico.

Gulf of Mexico, northern coastal

2,473 (0.25)/2,004

Gulf of Mexico

St. Andrew Bay, Pascagoula River.

Strategic

Gulf of Mexico, western coastal

Unknown

Gulf of Mexico

Corpus Christi Bay, Galveston Bay.

Gulf of Mexico Oceanic

3,708 (0.42)/2,641

Gulf of Mexico.

Strategic

Gulf of Mexico bay, sound, and estuarine

Unknown

Gulf of Mexico

St. Andrew Bay, Pascagoula River, Sabine Lake, Corpus Christi Bay, and Galveston Bay.

Pantropical spotted dolphin

Stenella attenuata

Western North Atlantic

4,439 (0.49)/3,010

Gulf Stream, North Atlantic Gyre

Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf.

Gulf of Mexico Oceanic

34,067 (0.18)/29,311

Gulf of Mexico, Caribbean Sea.

Atlantic spotted dolphin

Stenella frontalis

Western North Atlantic

50,978 (0.42)/36,235

Gulf Stream

Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Gulf of Mexico (Continental shelf and Oceanic)

Unknown

Gulf of Mexico, Caribbean Sea.

Spinner dolphin

Stenella longirostris

Western North Atlantic

Unknown

Gulf Stream, North Atlantic Gyre

Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf.

Gulf of Mexico Oceanic

1,989 (0.48)/1,356

Gulf of Mexico, Caribbean Sea.

Clymene dolphin

Stenella clymene

Western North Atlantic

Unknown

Gulf Stream

Southeast U.S. Continental Shelf.

Gulf of Mexico Oceanic

6,575 (0.36)/4,901

Gulf of Mexico, Caribbean Sea.

Striped dolphin

Stenella coeruleoalba

Western North Atlantic

94,462 (0.4)/68,558

Gulf Stream.

Gulf of Mexico Oceanic

3,325 (0.48)/2,266

Gulf of Mexico, Caribbean Sea.

Fraser's dolphin

Lagenodelphis hosei

Western North Atlantic

Unknown

North Atlantic Gyre

Southeast U.S. Continental Shelf.

Gulf of Mexico Oceanic

Unknown

Gulf of Mexico, Caribbean Sea.

Risso's dolphin

Grampus griseus

Western North Atlantic

20,479 (0.59)/12,920

Gulf Stream

Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Gulf of Mexico Oceanic

1,589 (0.27)/1,271

Gulf of Mexico, Caribbean Sea.

Atlantic white-sided dolphin

Lagenorhynchus acutus

Western North Atlantic

63,368 (0.27)/50,883

Labrador Current

Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

White-beaked dolphin

Lagenorhynchus albirostris

Western North Atlantic

2,003 (0.94)/1,023

Labrador Current

Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Long-beaked common dolphin

Delphinus capensis

NA

13

Unknown

13

Caribbean Sea 13.

Short-beaked common dolphin

Delphinus delphis

Western North Atlantic

120,743 (0.23)/99,975

Gulf Stream

Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Melon-headed whale

Peponocephala electra

Western North Atlantic

Unknown

Gulf Stream, North Atlantic Gyre

Southeast U.S. Continental Shelf.

Gulf of Mexico Oceanic

2,283 (0.76)/1,293

Gulf of Mexico, Caribbean Sea.

Pygmy killer whale

Feresa attenuata

Western North Atlantic

Unknown

Gulf Stream, North Atlantic Gyre

Southeast U.S. Continental Shelf.

Gulf of Mexico Oceanic

323 (0.6)/203

Gulf of Mexico, Caribbean Sea, Southeast U.S. Continental Shelf.

False killer whale

Pseudorca crassidens

Gulf of Mexico Oceanic

777 (0.56)/501

Gulf Stream, North Atlantic Gyre

Gulf of Mexico, Caribbean Sea, Southeast U.S. Continental Shelf.

Killer whale

Orcinus orca

Western North Atlantic

Unknown

Gulf Stream, North Atlantic Gyre, Labrador Current

Southeast U.S. Continental Shelf, Northeast U.S. Continental shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Gulf of Mexico Oceanic

49 (0.77)/28

Gulf of Mexico, Caribbean Sea.

Long-finned pilot whale

Globicephala melas

Western North Atlantic

12,619 (0.37)/9,333

Gulf Stream

Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Short-finned pilot whale

Globicephala macrorhynchus

Western North Atlantic

24,674 (0.45)/17,190

Gulf Stream

Northeast U.S. Continental Shelf, Southeast U.S. Continental Shelf.

Gulf of Mexico Oceanic

716 (0.34)/542

Gulf of Mexico, Caribbean Sea.

Family Phocoenidae (porpoises)

Harbor porpoise

Phocoena phocoena

Gulf of Maine/Bay of Fundy

89,054 (0.47)/60,970

Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf

Narragansett Bay, Rhode Island Sound, Block Island Sound, Buzzards Bay, Vineyard Sound, Long Island Sound, Piscataqua River, Thames River, Kennebec River.

Order Carnivora

Suborder Pinnipedia

Family Phocidae (true seals)

Ringed seal

Pusa hispida

Proposed

15

NA

14

Unknown

Newfoundland-Labrador Shelf, West Greenland Shelf.

Bearded seal

Erignathus barbatus

NA

14

Unknown

Scotian Shelf, Newfoundland-Labrador Shelf, West Greenland Shelf.

Hooded seal

Cystophora cristata

Western North Atlantic

592,100/512,000

Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf, West Greenland Shelf

Narragansett Bay, Rhode Island Sound, Block Island Sound, Buzzards Bay, Vineyard Sound, Long Island Sound, Piscataqua River, Thames River, Kennebec River.

Harp seal

Pagophilus groenlandicus

Western North Atlantic

Unknown

Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf.

Gray seal

Halichoerus grypus

Western North Atlantic

Unknown

Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf

Narragansett Bay, Rhode Island Sound, Block Island Sound, Buzzards Bay, Vineyard Sound, Long Island Sound, Piscataqua River, Thames River, Kennebeck River.

Harbor seal

Phoca vitulina

Western North Atlantic

Unknown

16

Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf, Scotian Shelf, Newfoundland-Labrador Shelf

Narragansett Bay, Rhode Island Sound, Block Island Sound, Buzzards Bay, Vineyard Sound, Long Island Sound, Piscataqua River, Thames River, Kennebeck River.

1

Taxonomy follows Perrin 2009.

2

ESA listing status. All marine mammals are protected under MMPA. Populations or stocks for which the level of direct human-caused mortality exceeds the potential biological removal level, which, based on the best available scientific information, is declining and is likely to be listed as a threatened species under the ESA within the foreseeable future, or is listed as a threatened or endangered species under the ESA, or is designated as depleted under the MMPA are considered “strategic” under MMPA.

3

Best CV/Min is a statistic measurement used as an indicator of the accuracy of the estimate. Stock designations for the U.S. Exclusive Economic Zone and abundance estimates from 2010 Stock Assessment Report (Waring

et al.

2010).

4

Occurrence in the Study Area includes open ocean areas—Labrador Current, North Atlantic Gyre, and Gulf Stream, and coastal/shelf waters of seven Large Marine Ecosystems—Gulf of Mexico, Southeast U.S. Continental Shelf, Northeast U.S. Continental Shelf, Caribbean Sea, Scotian Shelf, Newfoundland-Labrador Shelf, West Greenland Shelf, and inland waters of—Kennebec River, Piscataqua River, Thames River, Narragansett Bay, Rhode Island Sound, Block Island Sound, Buzzards Bay, Vineyard Sound, Long Island Sound, Sandy Hook Bay, Lower Chesapeake Bay, James River, Elizabeth River, Beaufort Inlet, Cape Fear River, Kings Bay, St. Johns River, Port Canaveral, St. Andrew Bay, Pascagoula River, Sabine Lake, Corpus Christi Bay, and Galveston Bay.

5

This species occurs in the Atlantic outside of the U.S. Exclusive Economic Zone; and therefore has no associated Stock Assessment Report. See the appropriate subsections below for details of populations that may be found within the Study Area. Abundance and 95 percent confidence interval are provided by the International Whaling Commission.

6

Photo identification catalogue count of 440 recognizable blue whale individuals from the Gulf of St. Lawrence is considered to be a minimum population estimate for the western North Atlantic stock.

7

Estimate may include both the pygmy and dwarf sperm whales.

8

This species occurs in the Atlantic outside of the U.S. Exclusive Economic Zone; and therefore has no associated Stock Assessment Report. See the appropriate subsections below for details of populations that may be found within the Study Area.

9

Narwhals in the Atlantic are not managed by NMFS and have no associated Stock Assessment Report.

10

Estimate includes Cuvier's beaked whales and undifferentiated Mesoplodon species.

11

Estimate includes Gervais' and Blainville's beaked whales.

12

Estimate may include sightings of the coastal form.

13

Long-beaked common dolphins are only known in the western Atlantic from a discrete population off the east coast of South America.

14

This species occurs in the Atlantic outside of the U.S. Exclusive Economic Zone; and therefore has no associated Stock Assessment Report. See the appropriate subsections below for details of populations that may be found within the Study Area.

15

Arctic sub-species of ringed seal has been proposed as threatened under the ESA (75

Federal Register

[FR] 77476).

16

2010 Stock Assessment Report states that present data are insufficient to calculate a minimum population estimate for this stock, however, the 2009 Stock Assessment Report indicated the “best” population estimate was 99,340 (CV = .097) and minimum population estimate was 91,546.

NMFS has reviewed the information complied by the Navy on the abundance, behavior, status and distribution, and vocalizations of marine mammal species in the waters of the AFTT Study Area, which was derived from peer reviewed literature, the Navy Marine Resource Assessments, NMFS Stock Assessment Reports, and marine mammal surveys using acoustic or visual observations from aircraft or ships. NMFS considers this information to be the best available science with which we can conduct the analyses necessary to propose these regulations and future LOAs. This information may be viewed in the Navy's LOA application and the Navy's EIS for AFTT (

see

Availability). Additional information is available in the NMFS Stock Assessment Reports, which may be viewed at:

http://www.nmfs.noaa.gov/pr/sars/species.htm

.

Bowhead whales, beluga whales, and narwhal are considered rare in the AFTT Study Area. Bowhead whales inhabit only the arctic and subarctic regions, often close to the ice edge. The St. Lawrence estuary is at the southern limit of the beluga whales' distribution (Lesage and Kingsley, 1998). Beluga distribution does not include the Gulf of Mexico or the southeastern Atlantic coast and they are considered extralimital in the Northeast. Narwhals inhabit Arctic waters, but populations from the Hudson Strait and Davis Strait—at the northwest extreme of the Study Area—may extend into the AFTT Study Area, but the possibility of narwhal actually occurring is considered remote. Based on the rare occurrence of these species in the AFTT Study Area, the Navy and NMFS do not anticipate any take of bowhead whales, beluga whales, or narwhals; therefore, these species are not addressed further in this proposed rule.

Important Areas

NMFS identifies biologically important areas when considering an application to authorize the incidental take of marine mammals. The negligible impact finding necessary for the issuance of an MMPA authorization requires NMFS to consider areas where marine mammals are known to selectively breed or calve/pup. In addition, NMFS must prescribe regulations setting forth the permissible methods of taking and other means of effecting the least practicable adverse impact on marine mammals species or stocks by paying particular attention to rookeries, mating grounds, and other areas of similar significance. This section identifies and discusses known important reproductive and feeding areas within the AFTT Study Area.

Little is known about the breeding and calving behaviors of many of the marine mammals that occur within the AFTT Study Area. For rorquals (humpback whale, minke whale, Bryde's whale, sei whale, fin whale, and blue whale) and sperm whales, mating is generally thought to occur in tropical and sub-tropical waters between mid-winter and mid-summer in deep offshore waters. Delphinids (Melon-headed whale, killer whale, pygmy killer whale, false killer whale, pilot whale, common dolphin, Atlantic spotted dolphin, clymene dolphin, pantropical spotted dolphin, spinner dolphin, striped dolphin, rough-toothed dolphin, bottlenose dolphin, Risso's dolphin, Fraser's dolphin, Atlantic white-sided dolphin, white-beaked dolphin) may mate throughout their distribution during any time of year. For pinnipeds, mating and pupping typically occur in coastal waters near northeast rookeries. With one notable exception, no specific areas for breeding or calving/pupping have been identified in the AFTT Study Area for the species that occur there. However, under the Endangered Species Act (ESA), critical habitat has been designated for the North Atlantic right whale. Additional biologically important areas have been identified for humpback whales and sperm whales. Biologically important areas for all three species are discussed below.

North Atlantic Right Whale

Most North Atlantic right whale sightings follow a well-defined seasonal migratory pattern through several consistently utilized habitats (Winn

et al.,

1986). It should be noted, however, that some individuals may be sighted in these habitats outside of the typical time of year and that migration routes are not well known (there may be a regular offshore component). The population migrates as two separate components, although some whales may remain in the feeding grounds throughout the winter (Winn

et al.,

1986, Kenney

et al.,

2001). Pregnant females and some juveniles migrate from the feeding grounds to the calving grounds off the southeastern United States in late fall to winter. The cow-calf pairs return northward in late winter to early spring. The majority of the right whale population leaves the feeding grounds for unknown habitats in the winter but returns to the feeding grounds coinciding with the return of the cow-calf pairs. Some individuals as well as cow-calf pairs can be seen through the fall and winter on the feeding grounds

with feeding being observed (e.g., Sardi

et al.,

2005).

During the spring through early summer, North Atlantic right whales are found on feeding grounds off the northeastern United States and Canada. Individuals may be found in Cape Cod Bay in February through April (Winn

et al.,

1986; Hamilton and Mayo, 1990) and in the Great South Channel east of Cape Cod in April through June (Winn

et al.,

1986; Kenney

et al.,

1995). Right whales are found throughout the remainder of summer and into fall (June through November) on two feeding grounds in Canadian waters (Gaskin, 1987 and 1991), with peak abundance in August, September, and early October. The majority of summer/fall sightings of mother/calf pairs occur east of Grand Manan Island (Bay of Fundy), although some pairs might move to other unknown locations (Schaeff

et al.,

1993). Jeffreys Ledge appears to be important habitat for right whales, with extended whale residences; this area appears to be an important fall feeding area for right whales and an important nursery area during summer (Weinrich

et al.,

2000). The second feeding area is off the southern tip of Nova Scotia in the Roseway Basin between Browns, Baccaro, and Roseway banks (Mitchell

et al.,

1986; Gaskin, 1987; Stone

et al.,

1988; Gaskin, 1991). The Cape Cod Bay and Great South Channel feeding grounds have been designated as critical habitat under the ESA (Silber and Clapham, 2001).

During the winter (as early as November and through March), North Atlantic right whales may be found in coastal waters off North Carolina, Georgia, and northern Florida (Winn

et al.,

1986). The waters off Georgia and northern Florida are the only known calving ground for western North Atlantic right whales and they have been designated as critical habitat under the ESA. Calving occurs from December through March (Silber and Clapham, 2001). On 1 January 2005, the first observed birth on the calving grounds was reported (Zani

et al.,

2005). The majority of the population is not accounted for on the calving grounds, and not all reproductively active females return to this area each year (Kraus

et al.,

1986a).

The coastal waters of the Carolinas are suggested to be a migratory corridor for the right whale (Winn

et al.,

1986). This area, consisting of coastal waters between North Carolina and northern Florida, was mainly a winter and early spring (January-March) right whaling ground during the late 1800s (Reeves and Mitchell, 1986). The whaling ground was centered along the coasts of South Carolina and Georgia (Reeves and Mitchell, 1986). An examination of sighting records from all sources between 1950 and 1992 found that wintering right whales were observed widely along the coast from Cape Hatteras, North Carolina, to Miami, Florida (Kraus

et al.,

1993). Sightings off the Carolinas were comprised of single individuals that appeared to be transients (Kraus

et al.,

1993). These observations are consistent with the hypothesis that the coastal waters of the Carolinas are part of a migratory corridor for the North Atlantic right whale (Winn

et al.,

1986). Knowlton

et al.

(2002) analyzed sightings data collected in the mid-Atlantic from northern Georgia to southern New England and found that the majority of North Atlantic right whale sightings occurred within approximately 30 NM (56 km) from shore. Critical habitat for the north Atlantic population of the North Atlantic right whale exists in portions of the JAX and Northeast OPAREAs (Figure 4-1 of the Navy's Application). The following three areas occur in U.S. waters and were designated by NMFS as critical habitat in June 1994 (NMFS, 2005):

• Coastal Florida and Georgia (Sebastian Inlet, Florida, to the Altamaha River, Georgia),

• The Great South Channel, east of Cape Cod, and

• Cape Cod and Massachusetts Bays.

The northern critical habitat areas serve as feeding and nursery grounds, while the southern area from the mid-Georgia coast extending southward along the Florida coast serves as calving grounds. A large portion of this habitat lies within the coastal waters of the JAX OPAREA. The physical features correlated with the distribution of right whales in the southern critical habitat area provide an optimum environment for calving. For example, the bathymetry of the inner and nearshore middle shelf area minimizes the effect of strong winds and offshore waves, limiting the formation of large waves and rough water. The average temperature of critical habitat waters is cooler during the time right whales are present due to a lack of influence by the Gulf Stream and cool freshwater runoff from coastal areas. The water temperatures may provide an optimal balance between offshore waters that are too warm for nursing mothers to tolerate, yet not too cool for calves that may only have minimal fatty insulation. On the calving grounds, the reproductive females and calves are expected to be concentrated near the critical habitat in the JAX OPAREA from December through April.

Two additional biologically important habitat areas are located in Canadian waters—Grand Manan Basin and Roseway Basin. These areas were identified in Canada's final recovery strategy for the North Atlantic right whale. On October 6, 2010, NMFS published a notice announcing 90-day finding and 12-month determination on a petition to revise critical habitat for the North Atlantic right whale (75 FR 61690). NMFS found that the petition, in addition with the information readily available, presents substantial scientific information indicating that the requested revision may be warranted. NMFS determined that we would proceed with the ongoing rulemaking process for revising critical habitat for the North Atlantic right whale.

Humpback Whale

In the North Atlantic Ocean, humpbacks are found from spring through fall on feeding grounds that are located from south of New England to northern Norway (NMFS, 1991). The Gulf of Maine is one of the principal summer feeding grounds for humpback whales in the North Atlantic. The largest numbers of humpback whales are present from mid-April to mid- November. Feeding locations off the northeastern United States include Stellwagen Bank, Jeffreys Ledge, the Great South Channel, the edges and shoals of Georges Bank, Cashes Ledge, Grand Manan Banks, the banks on the Scotian Shelf, the Gulf of St. Lawrence, and the Newfoundland Grand Banks (CETAP, 1982; Whitehead, 1982; Kenney and Winn, 1986; Weinrich

et al.,

1997). Distribution in this region has been largely correlated to prey species and abundance, although behavior and bottom topography are factors in foraging strategy (Payne

et al.,

1986; Payne

et al.,

1990b). Humpbacks typically return to the same feeding areas each year.

Feeding most often occurs in relatively shallow waters over the inner continental shelf and sometimes in deeper waters. Large multi-species feeding aggregations (including humpback whales) have been observed over the shelf break on the southern edge of Georges Bank (CETAP, 1982; Kenney and Winn, 1987) and in shelf break waters off the U.S. mid-Atlantic coast (Smith

et al.,

1996).

Sperm Whale

The region of the Mississippi River Delta (Desoto Canyon) has been recognized for high densities of sperm whales and may potentially represent an important calving and nursery, or feeding area for these animals

(Townsend, 1935; Collum and Fritts, 1985; Mullin

et al.,

1994a; Würsig

et al.,

2000; Baumgartner

et al.,

2001; Davis

et al.,

2002; Mullin

et al.,

2004; Jochens

et al.,

2006). Sperm whales typically exhibit a strong affinity for deep waters beyond the continental shelf, though in the area of the Mississippi Delta they also occur on the outer continental shelf break.

Marine Mammal Density Estimates

A quantitative analysis of impacts on a species requires data on the abundance and distribution of the species population in the potentially impacted area. One metric for performing this type of analysis is density, which is the number of animals present per unit area. The Navy compiled existing, publically available density data for use in the quantitative acoustic impact analysis.

There is no single source of density data for every area of the world, species, and season because of the costs, resources, and effort required to provide adequate survey coverage to sufficiently estimate density. Therefore, to estimate the marine mammal densities for large areas like the AFTT Study Area, the Navy compiled data from several sources. To compile and structure the most appropriate database of marine species density data, the Navy developed a protocol to select the best available data sources based on species, area, and time (season). The resulting Geographic Information System database, called the Navy Marine Species Density Database, includes seasonal density values for every marine mammal species present within the AFTT Study Area (Navy, 2012).

The Navy Marine Species Density Database includes a compilation of the best available density data from several primary sources and published works including survey data from NMFS within the U.S. Exclusive Economic Zone.

Additional information on the density data sources and how the database was applied to the AFTT Study Area is detailed in the Navy Marine Species Density Database Technical Report (

aftteis.com/DocumentsandReferences/AFTTDocuments/SupportingTechnicalDocuments.aspx

).

Marine Mammal Hearing and Vocalizations

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

Marine mammal vocalizations often extend both above and below the range of human hearing; vocalizations with frequencies lower than 20 Hz are labeled as infrasonic and those higher than 20 kHz as ultrasonic (National Research Council (NRC), 2003; Figure 4-1). Measured data on the hearing abilities of cetaceans are sparse, particularly for the larger cetaceans such as the baleen whales. The auditory thresholds of some of the smaller odontocetes have been determined in captivity. It is generally believed that cetaceans should at least be sensitive to the frequencies of their own vocalizations. Comparisons of the anatomy of cetacean inner ears and models of the structural properties and the response to vibrations of the ear's components in different species provide an indication of likely sensitivity to various sound frequencies. The ears of small toothed whales are optimized for receiving high-frequency sound, while baleen whale inner ears are best in low to infrasonic frequencies (Ketten, 1992; 1997; 1998).

Baleen whale vocalizations are composed primarily of frequencies below 1 kHz, and some contain fundamental frequencies as low as 16 Hz (Watkins

et al.,

1987; Richardson

et al.,

1995; Rivers, 1997; Moore

et al.,

1998; Stafford

et al.,

1999; Wartzok and Ketten, 1999) but can 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 baleen whales 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 μPa 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 μPa at 1 m (Richardson

et al.,

1995). No odontocete has been shown audiometrically to have acute hearing (<80 dB re 1 μPa) below 500 Hz (Southall

et al.,

2007). 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 μPa 1 m or greater (Mohl

et al.,

2000).

Brief Background on Sound

An understanding of the basic properties of underwater sound is necessary to comprehend many of the concepts and analyses presented in this document. A summary is included below.

Sound is a wave of pressure variations propagating through a medium (e.g., water). Sound measurements can be expressed in two forms: intensity and pressure. Acoustic intensity is the average rate of energy transmitted through a unit area in a specified direction and is expressed in watts per square meter (W/m

2

). Acoustic intensity is rarely measured directly, but rather from ratios of pressures; the standard reference pressure for underwater sound is 1 microPascal (μPa); for airborne sound, the standard reference pressure is 20 μPa (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 μPa or, for airborne sound, 20 μPa.). The logarithmic nature of the scale means that each 10-dB increase is a ten-fold increase in acoustic power (and a 20-dB increase is then a 100-fold increase in power; and a 30-dB increase is a 1,000-fold increase in power). A ten-fold increase in acoustic power does not mean that the sound is perceived as being ten times louder. Humans perceive a 10-dB increase in sound level as a doubling of loudness, and a 10-dB decrease in sound level as a halving of loudness. The term “sound pressure level” implies a decibel measure and a reference pressure that is used as the denominator of the ratio. Throughout this document, NMFS uses 1 microPascal (denoted re: 1μPa) as a standard reference pressure unless noted otherwise.

It is important to note that decibels underwater and decibels in air are not the same and cannot be directly compared. To estimate a comparison between sound in air and underwater, because of the different densities of air and water and the different decibel standards (i.e., reference pressures) in air and water, a sound with the same intensity (i.e., power) in air and in water would be approximately 62 dB lower in air. Thus a sound that measures 160 dB (re 1μPa) underwater would have the same approximate effective level as a sound that is 98 dB (re 20 1μPa) 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”; tactical sonars are an example of a narrowband sound source and explosives are an example of a broadband 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) designated “functional hearing groups” for marine mammals and estimated 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):

• Low frequency cetaceans (13 species of mysticetes): functional hearing is estimated to occur between approximately 7 Hz and 30 kHz.

• 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.

• 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.

• 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.

The estimated hearing range for low-frequency cetaceans has been slightly extended from previous analyses (from 22 to 30 kHz). This decision is based on data from Watkins

et al.

(1986) for numerous mysticete species, Au

et al.

(2006) for humpback whales, and abstract from Frankel (2005) and a paper from Lucifredi and Stein (2007) on gray whales, and an unpublished report (Ketten and Mountain, 2009) and abstract (Tubelli

et al.,

2012) for minke whales. As more data from additional species become available, these estimated hearing ranges may require modification.

When sound travels away (propagates) 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 referenced to one meter from the source) as the source level and the loudness of sound elsewhere as the received level (i.e., typically the receiver). For example, a humpback whale 3 kilometers from a device that has a source level of 230 dB re 1 μPa may only be exposed to sound that is 160 dB re 1 μPa loud, depending on how the sound travels through the water (in this example, it is spherical spreading [3 dB reduction with doubling of distance]). As a result, it is important to understand the difference between source levels and received levels when discussing the loudness of sound in the ocean or its impacts on the marine environment.

As sound travels from a source, its propagation in water is influenced by various physical characteristics, including water temperature, depth, salinity, and surface and bottom properties that cause refraction, reflection, absorption, and scattering of sound waves. Oceans are not homogeneous and the contribution of each of these individual factors is extremely complex and interrelated. The physical characteristics that determine the sound's speed through the water will change with depth, season, geographic location, and with time of day (as a result, in actual sonar operations, crews will measure oceanic conditions, such as sea water temperature and depth, to calibrate models that determine the path the sonar signal will take as it travels through the ocean and how strong the

sound signal will be at a given range along a particular transmission path). 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 to describe sound levels 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 (μPa), where 1 Pa is the pressure resulting from a force of one newton exerted over an area of one square meter. SPL is expressed as the ratio of a measured sound pressure and a reference level.

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

The commonly used reference pressure level in underwater acoustics is 1 μPa, and the units for SPLs are dB re: 1 μPa. SPL is an instantaneous measurement and can be expressed as the peak, the peak-to-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 Behavioral Response Function (BRF), which is used to estimate behavioral harassment takes.

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 μPa

2

s.

SEL = SPL + 10 log(duration in seconds)

As applied to sonar and other active acoustic sources, 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 cumulative SEL. The cumulative SEL depends on the SPL, duration, and number of pings received. The thresholds that NMFS uses to indicate at what received level the onset of temporary threshold shift (TTS) and permanent threshold shift (PTS) in hearing are likely to occur are expressed as cumulative SEL.

Potential Effects of Specified Activities on Marine Mammals

The Navy has requested authorization for the take of marine mammals that may occur incidental to training and testing activities in the AFTT Study Area. The Navy has analyzed the potential impacts on marine mammals from impulsive and non-impulsive sound sources and vessel strikes.

Other potential impacts on marine mammals from AFTT training and testing activities were analyzed in the Navy's AFTT EIS/OEIS, in consultation with NMFS as a cooperating agency, and determined to be unlikely to result in marine mammal harassment. Therefore, the Navy has not requested authorization for take of marine mammals that might occur incidental to other components of their proposed activities. In this document, NMFS analyzes the potential effects on marine mammals from exposure to non-impulsive (sonar and other active acoustic sources) and impulsive (underwater detonations, pile driving, and air guns) stressors, and vessel strikes.

For the purpose of MMPA authorizations, NMFS' effects assessments serve four primary purposes: (1) To prescribe the permissible methods of taking (i.e., Level B Harassment (behavioral harassment), Level A Harassment (injury), or mortality, including an identification of the number and types of take that could occur by harassment or mortality) and to prescribe other means of effecting the least practicable adverse impact on such species or stock and its habitat (i.e., mitigation); (2) to determine whether the specified activity would have a negligible impact on the affected species or stocks of marine mammals (based on the likelihood that the activity would adversely affect the species or stock through effects on annual rates of recruitment or survival); (3) to determine whether the specified activity would have an unmitigable adverse impact on the availability of the species or stock(s) for subsistence uses (however, there are no subsistence communities that would be affected in the AFTT Study Area, so this determination is inapplicable to the AFTT rulemaking); and (4) to prescribe requirements pertaining to monitoring and reporting.

More specifically, for activities involving non-impulsive or impulsive sources, NMFS' analysis will identify the probability of lethal responses, physical trauma, sensory impairment (permanent and temporary threshold shifts and acoustic masking), physiological responses (particular stress responses), behavioral disturbance (that rises to the level of harassment), and social responses (effects to social relationships) that would be classified as a take and whether such take will have a negligible impact on such species or stocks. Vessel strikes, which have the potential to result in incidental take from direct injury and/or mortality, will be discussed in more detail in the Estimated Take of Marine Mammals Section. In this section, we will focus qualitatively on the different ways that non-impulsive and impulsive sources may affect marine mammals (some of which NMFS does not classify as harassment). Then, in the Estimated Take of Marine Mammals Section, we will relate the potential effects on marine mammals from non-impulsive and impulsive sources to the MMPA definitions of Level A and Level B Harassment, along with the potential effects from vessel strikes, and attempt to quantify those effects.

Non-Impulsive Sources

Direct Physiological Effects

Based on the literature, there are two basic ways that non-impulsive sources might directly result in direct physiological effects: 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 received at a higher level for an animal to recognize them) following exposure to a sufficiently intense sound, it is referred to as a noise-induced threshold shift (TS). An animal can experience temporary threshold shift (TTS) or permanent threshold shift (PTS). TTS can last from minutes or hours to days (i.e., there is recovery), occurs in specific frequency ranges (i.e., an animal might only have a temporary loss of hearing sensitivity between the frequencies of 1 and 10 kHz)), and can be of varying amounts (for example, an animal's hearing sensitivity might be reduced by only 6 dB or reduced by 30

dB). PTS is permanent, but some recovery is possible. PTS can also occurs in a specific frequency range and amount as mentioned above for TTS.

The following physiological mechanisms are thought to play a role in inducing auditory TSs: Effects on sensory hair cells in the inner ear that reduce their sensitivity, modification of the chemical environment within the sensory cells, residual muscular activity in the middle ear, displacement of certain inner ear membranes, increased blood flow, and post-stimulatory reduction in both efferent and sensory neural output (Southall

et al.,

2007). The amplitude, duration, frequency, temporal pattern, and energy distribution of sound exposure all affect the amount of associated TS and the frequency range in which it occurs. As amplitude and duration of sound exposure increase, so, generally, does the amount of TS, along with the recovery time. For continuous sounds, exposures of equal energy (the same SEL) will lead to approximately equal effects. 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 sonar and other active acoustic sources, 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 are limited to the captive bottlenose dolphin, beluga, harbor porpoise, and Yangtze finless porpoise (Finneran

et al.,

2000, 2002b, 2003, 2005a, 2007, 2010a, 2010b; Finneran and Schlundt, 2010; Lucke et al, 2009; Mooney

et al.,

2009a, 2009b; Popov

et al.,

2011a, 2011b; Popov and Supin, 2012; Kastelein

et al.,

2012a; Schlundt

et al.,

2000; Nachtigall

et al.,

2003, 2004). For pinnipeds in water, data are limited to measurement of TTS in harbor seals, one elephant seal, and California sea lions (Kastak

et al.,

1999, 2005; Kastelien

et al.,

2012b).

Marine mammal hearing plays a critical role in communication with conspecifics, and interpretation of environmental cues for purposes such as predator avoidance and prey capture. Depending on the degree (elevation of threshold in dB), duration (i.e., recovery time), and frequency range of TTS, and the context in which it is experienced, TTS can have effects on marine mammals ranging from discountable to serious (similar to those discussed in auditory masking, below). For example, a marine mammal may be able to readily compensate for a brief, relatively small amount of TTS in a non-critical frequency range that 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 time when communication is critical for successful mother/calf interactions could have more serious impacts. Also, depending on the degree and frequency range, the effects of PTS on an animal could range in severity, although it is considered generally more serious because it is a permanent condition. Of note, reduced hearing sensitivity as a simple function of aging has been observed in marine mammals, as well as humans and other taxa (Southall

et al.,

2007), so we can infer that strategies exist for coping with this condition to some degree, though likely not without cost.

Acoustically Mediated Bubble Growth

A suggested indirect 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. The process depends on many factors, including the sound pressure level and duration. Under this hypothesis, microscopic bubbles assumed to exist in the tissues of marine mammals may experience one of three things: (1) Bubbles grow to the extent that tissue hemorrhage (injury) occurs; (2) bubbles develop to the extent that an immune response is triggered or nervous system tissue is subjected to enough localized pressure that pain or dysfunction occurs (a stress response without injury); or (3) the bubbles are cleared by the lung without negative consequence to the animal. The probability of rectified diffusion, or any other indirect tissue effect, will necessarily be based on what is known about the specific process involved. Rectified diffusion is 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 nitrogen gas to a greater degree than is supported by the surrounding environmental pressure (Ridgway and Howard, 1979). The dive patterns of some marine mammals (for example, beaked whales) are theoretically predicted to induce greater nitrogen gas supersaturation (Houser

et al.,

2001). If rectified diffusion were possible in marine mammals exposed to a high level of 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 (e.g., nausea, disorientation, localized pain, breathing problems, etc.).

It is unlikely that the short duration of sonar or explosion sounds would last long enough to drive bubble growth to any substantial size, if such a phenomenon occurs. However, an alternative but related hypothesis is also suggested: stable microbubbles could be destabilized by high-level sound exposures so bubble growth would occur 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 time for bubbles to become a problematic size. Recent research with

ex vivo

supersaturated bovine tissues suggests that for a 37 kHz signal, a sound exposure of approximately 215 dB re 1 μPa would be required before microbubbles became destabilized and grew (Crum

et al.,

2005). Assuming spherical spreading loss and a nominal sonar source level of 235 dB re 1 μPa, a whale would need to be within 33 ft. (10 m) of the sonar dome to be exposed to such sound levels. Furthermore, tissues in the study were supersaturated by exposing them to pressures of 400 to 700 kiloPascals (kPa) for periods of hours and then releasing them to

ambient pressures. Assuming the equilibration of gases with the tissues occurred when the tissues were exposed to the high pressures, levels of supersaturation in the tissues could have been as high as 400 to 700 percent. These levels of tissue supersaturation are substantially higher than model predictions for marine mammals (Houser

et al.,

2001). It is improbable that this mechanism would be responsible for stranding events or traumas associated with beaked whale strandings. Both the degree of supersaturation and exposure levels observed to cause microbubble destabilization are unlikely to occur, either alone or in concert.

There is considerable disagreement among scientists as to the likelihood of bubble formation in diving marine mammals (Evans and Miller, 2003; Piantadosi and Thalmann, 2004). Although it has been argued that traumas from recent beaked whale strandings are consistent with gas emboli and bubble-induced tissue separations (Fernández

et al.,

2005; Jepson

et al.,

2003), nitrogen bubble formation as the cause of the traumas has not been verified. The presence of bubbles postmortem, particularly after decompression, is not necessarily indicative of bubble pathology. Prior experimental work demonstrates that the postmortem presence of bubbles following decompression in laboratory animals can occur as a result of invasive investigative procedures (Stock

et al.,

1980). Also, variations in diving behavior or avoidance responses can possibly result in nitrogen tissue supersaturation and nitrogen off-gassing, possibly to the point of deleterious vascular bubble formation (Jepson

et al.,

2003). The mechanism for bubble formation would be different from rectified diffusion, but the effects would be similar. Although hypothetical, the potential process is under debate in the scientific community. The hypothesis speculates that if exposure to a startling sound elicits a rapid ascent to the surface, tissue gas saturation sufficient for the evolution of nitrogen bubbles might result (Fernández

et al.,

2005; Jepson

et al.,

2003). In this scenario, the rate of ascent would need to be sufficiently rapid to compromise behavioral or physiological protections against nitrogen bubble formation.

Recent modeling suggests that even unrealistically rapid rates of ascent from normal dive behaviors are unlikely to result in supersaturation to the extent that bubble formation would be expected in beaked whales (Zimmer and Tyack, 2007). Tyack

et al.

(Tyack

et al.,

2006) suggested that emboli observed in animals exposed to mid-frequency active sonar (Fernández

et al.,

2005; Jepson

et al.,

2003) could stem instead from a behavioral response that involves repeated dives, shallower than the depth of lung collapse. A bottlenose dolphin was trained to repetitively dive to specific depths to elevate nitrogen saturation to the point that asymptomatic nitrogen bubble formation was predicted to occur. However, inspection of the vascular system of the dolphin via ultrasound did not demonstrate the formation of any nitrogen gas bubbles (Houser

et al.,

2009).

More recently, modeling has suggested that the long, deep dives performed regularly by beaked whales over a lifetime could result in the saturation of long-halftime tissues (e.g. fat, bone lipid) to the point that they are supersaturated when the animals are at the surface (Hooker

et al.

2009). Proposed adaptations for prevention of bubble formation under conditions of persistent tissue saturation have been suggested (Fahlman

et al.,

2006; Hooker

et al.,

2009), while the condition of supersaturation required for bubble formation has been demonstrated in bycatch animals drowned at depth and brought to the surface (Moore

et al.,

2009). Since bubble formation is facilitated by compromised blood flow, it has been suggested that rapid stranding may lead to bubble formation in animals with supersaturated, long-halftime tissues because of the stress of stranding and the cardiovascular collapse that can accompany it (Houser

et al.,

2009).

A fat embolic syndrome was identified by Fernández

et al.

(2005) coincident with the identification of bubble emboli in stranded beaked whales. The fat embolic syndrome was the first pathology of this type identified in marine mammals, and was thought to possibly arise from the formation of bubbles in fat bodies, which subsequently resulted in the release of fat emboli into the blood stream. Recently, Dennison

et al.

(2011) reported on investigations of dolphins stranded in 2009-2010 and, using ultrasound, identified gas bubbles in kidneys of 21 of 22 live-stranded dolphins and in the liver of two of 22. The authors postulated that stranded animals are unable to recompress by diving, and thus may retain bubbles that are otherwise re-absorbed in animals that can continue to dive. The researchers concluded that the minor bubble formation observed can be tolerated since the majority of stranded dolphins released did not re-strand. As a result, no marine mammals addressed in this analysis are given differential treatment due to the possibility for acoustically mediated bubble growth.

Acoustic Masking

Marine mammals use acoustic signals for a variety of purposes, which differ among species, but include communication between individuals, navigation, foraging, reproduction, and learning about their environment (Erbe and Farmer 2000, Tyack 2000). Masking, or auditory interference, generally occurs when sounds in the environment are louder than and of a similar frequency to, auditory signals an animal is trying to receive. Masking is a phenomenon that affects animals that are trying to receive acoustic information about their environment, including sounds from other members of their species, predators, prey, and sounds that allow them to orient in their environment. Masking these acoustic signals can disturb the behavior of individual animals, groups of animals, or entire populations.

The extent of the masking interference depends on the spectral, temporal, and spatial relationships between the signals an animal is trying to receive and the masking noise, in addition to other factors. In humans, significant masking of tonal signals occurs as a result of exposure to noise in a narrow band of similar frequencies. As the sound level increases, though, the detection of frequencies above those of the masking stimulus decreases also. This principle is expected to apply to marine mammals as well because of common biomechanical cochlear properties across taxa.

Richardson

et al.

(1995b) argued that the maximum radius of influence of an industrial noise (including broadband low frequency sound transmission) on a marine mammal is the distance from the source to the point at which the noise can barely be heard. This range is determined by either the hearing sensitivity of the animal or the background noise level present. Industrial masking is most likely to affect some species' ability to detect communication calls and natural sounds (i.e., surf noise, prey noise, etc.; Richardson

et al.,

1995).

The echolocation calls of toothed whales are subject to masking by high frequency sound. Human data indicate low-frequency sound can mask high-frequency sounds (i.e., upward masking). Studies on captive odontocetes by Au

et al.

(1974, 1985, 1993) indicate that some species may use various processes to reduce masking effects (e.g., adjustments in echolocation

call intensity or frequency as a function of background noise conditions). There is also evidence that the directional hearing abilities of odontocetes are useful in reducing masking at the high-frequencies these cetaceans use to echolocate, but not at the low-to-moderate frequencies they use to communicate (Zaitseva

et al.,

1980). A recent study by Nachtigall and Supin (2008) showed that false killer whales adjust their hearing to compensate for ambient sounds and the intensity of returning echolocation signals.

As mentioned previously, the functional hearing ranges of mysticetes, odontocetes, and pinnipeds underwater all encompass the frequencies of the sonar sources used in the Navy's training exercises. Additionally, almost all species, vocal repertoires span across the frequencies of these sonar sources used by the Navy. The closer the characteristics of the masking signal to the signal of interest, the more likely masking is to occur. For hull-mounted sonar, the duty cycle of the signal 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 it drops to the level of ambient noise (Brenowitz, 2004; Brumm

et al.,

2004; Lohr

et al.,

2003). Animals are also aware of environment 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. Anthropogenic sounds that reduce the signal-to-noise ratio of animal vocalizations, increase the masked auditory thresholds of animals listening for such vocalizations, or reduce the active space of an animal's vocalizations impair communication between animals. Most animals that vocalize have evolved strategies to compensate for the effects of short-term or temporary increases in background or ambient noise on their songs or calls. Although the fitness consequences of these vocal adjustments remain unknown, like most other trade-offs animals must make, some of these strategies probably come at a cost (Patricelli

et al.,

2006). For example, vocalizing more loudly in noisy environments may have energetic costs that decrease the net benefits of vocal adjustment and alter a bird's energy budget (Brumm, 2004; Wood and Yezerinac, 2006). Shifting songs and calls to higher frequencies may also impose energetic costs (Lambrechts, 1996).

Stress Responses

Classic stress responses begin when an animal's central nervous system perceives a potential threat to its homeostasis. That perception triggers stress responses regardless of whether a stimulus actually threatens the animal; the mere perception of a threat is sufficient to trigger a stress response (Moberg, 2000; Sapolsky

et al.,

2005; Seyle, 1950). Once an animal's central nervous system perceives a threat, it mounts a biological response or defense that consists of a combination of the four general biological defense responses: Behavioral responses, autonomic nervous system responses, neuroendocrine responses, or immune response.

In the case of many stressors, an animal's first and most economical (in terms of biotic costs) response is behavioral avoidance of the potential stressor or avoidance of continued exposure to a stressor. An animal's second line of defense to stressors involves the sympathetic part of the autonomic nervous system and the classical “fight or flight” response which includes the cardiovascular system, the gastrointestinal system, the exocrine glands, and the adrenal medulla to produce changes in heart rate, blood pressure, and gastrointestinal activity that humans commonly associate with “stress.” These responses have a relatively short duration and may or may not have significant long-term effect on an animal's welfare.

An animal's third line of defense to stressors involves its neuroendocrine or sympathetic nervous systems; the system that has received the most study has been the hypothalmus-pituitary-adrenal system (also known as the HPA axis in mammals or the hypothalamus-pituitary-interrenal axis in fish and some reptiles). Unlike stress responses associated with the autonomic nervous system, virtually all neuro-endocrine functions that are affected by stress—including immune competence, reproduction, metabolism, and behavior—are regulated by pituitary hormones. Stress-induced changes in the secretion of pituitary hormones have been implicated in failed reproduction (Moberg, 1987; Rivier, 1995) and altered metabolism (Elasser

et al.,

2000), reduced immune competence (Blecha, 2000) and behavioral disturbance. Increases in the circulation of glucocorticosteroids (cortisol, corticosterone, and aldosterone in marine mammals; see Romano

et al.,

2004) have been equated with stress for many years.

The primary distinction between stress (which is adaptive and does not normally place an animal at risk) and distress is the biotic cost of the response. During a stress response, an animal uses glycogen stores that can be quickly replenished once the stress is alleviated. In such circumstances, the cost of the stress response would not pose a risk to the animal's welfare. However, when an animal does not have sufficient energy reserves to satisfy the energetic costs of a stress response, energy resources must be diverted from other biotic function, which impairs those functions that experience the diversion. For example, when mounting a stress response diverts energy away from growth in young animals, those animals may experience stunted growth. When mounting a stress response diverts energy from a fetus, an animal's reproductive success and its fitness will suffer. In these cases, the animals will have entered a pre-pathological or pathological state which is called “distress” (sensu Seyle 1950) or “allostatic loading” (sensu McEwen and Wingfield, 2003). This pathological state will last until the animal replenishes its biotic reserves sufficient to restore normal function. Note that these examples involved a long-term (days or weeks) stress response exposure to 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). Information has also been collected on the physiological responses of marine mammals to exposure to anthropogenic sounds (Fair and Becker, 2000; Romano

et al.,

2002; Wright

et al.,

2008). For example, Rolland

et al.

(2012) found that noise reduction from reduced ship traffic in the Bay of Fundy was associated with decreased stress in North Atlantic right whales. In a conceptual model developed by the Population Consequences of Acoustic Disturbance (PCAD) working group, serum hormones were identified as possible indicators of behavioral effects that translated into altered rates of reproduction and mortality. The Office of Naval Research hosted a workshop (Effects of Stress on Marine Mammals Exposed to Sound) in 2009 that focused on this very topic (ONR, 2009).

Studies of other marine animals and terrestrial animals would lead us to expect some marine mammals to experience physiological stress responses and, perhaps, physiological responses that would be classified as “distress” upon exposure to high frequency, mid-frequency and low-frequency sounds. For example, Jansen (1998) reported on the relationship between acoustic exposures and physiological responses that are indicative of stress responses in humans (for example, elevated respiration and increased heart rates). Jones (1998) reported on reductions in human performance when faced with acute, repetitive exposures to acoustic disturbance. Trimper

et al.

(1998) reported on the physiological stress responses of osprey to low-level aircraft noise while Krausman

et al.

(2004) reported on the auditory and physiology stress responses of endangered Sonoran pronghorn to military overflights. Smith

et al.

(2004a, 2004b) identified noise-induced physiological transient stress responses in hearing-specialist fish (i.e., goldfish) that accompanied short- and long-term hearing losses. Welch and Welch (1970) reported physiological and behavioral stress responses that accompanied damage to the inner ears of fish and several mammals.

Hearing is one of the primary senses marine mammals use to gather information about their environment and to communicate with conspecifics. Although empirical information on the relationship between sensory impairment (TTS, PTS, and acoustic masking) on marine mammals remains limited, it seems reasonable to assume that reducing an animal's ability to gather information about its environment and to communicate with other members of its species would be stressful for animals that use hearing as their primary sensory mechanism. Therefore, we assume that acoustic exposures sufficient to trigger onset PTS or TTS would be accompanied by physiological stress responses because terrestrial animals exhibit those responses under similar conditions (NRC, 2003). More importantly, marine mammals might experience stress responses at received levels lower than those necessary to trigger onset TTS. Based on empirical studies of the time required to recover from stress responses (Moberg, 2000), we also assume that stress responses are likely to persist beyond the time interval required for animals to recover from TTS and might result in pathological and pre-pathological states that would be as significant as behavioral responses to TTS.

Behavioral Disturbance

Behavioral responses to sound are highly variable and context-specific. Many different variables can influence an animal's perception of and response to (nature and magnitude) an acoustic event. An animal's prior experience with a sound or sound source effects whether it is less likely (habituation) or more likely (sensitization) to respond to certain sounds in the future (animals can also be innately pre-disposed to respond to certain sounds in certain ways) (Southall

et al.,

2007). Related to the sound itself, the perceived nearness of the sound, bearing of the sound (approaching vs. retreating), similarity of a sound to biologically relevant sounds in the animal's environment (i.e., calls of predators, prey, or conspecifics), and familiarity of the sound may affect the way an animal responds to the sound (Southall

et al.,

2007). Individuals (of different age, gender, reproductive status, etc.) among most populations will have variable hearing capabilities, and differing behavioral sensitivities to sounds that will be affected by prior conditioning, experience, and current activities of those individuals. Often, specific acoustic features of the sound and contextual variables (i.e., proximity, duration, or recurrence of the sound or the current behavior that the marine mammal is engaged in or its prior experience), as well as entirely separate factors such as the physical presence of a nearby vessel, may be more relevant to the animal's response than the received level alone.

Exposure of marine mammals to sound sources can result in no response or responses including, but not limited to increased alertness; orientation or attraction to a sound source; vocal modifications; cessation of feeding; cessation of social interaction; alteration of movement or diving behavior; habitat abandonment (temporary or permanent); and, in severe cases, panic, flight, stampede, or stranding, potentially resulting in death (Southall

et al.,

2007). A review of marine mammal responses to anthropogenic sound was first conducted by Richardson and others in 1995. A review by Nowacek

et al.

(2007) addresses studies conducted since 1995 and focuses on observations where the received sound level of the exposed marine mammal(s) was known or could be estimated. The following sub-sections provide examples of behavioral responses that provide an idea of the variability in behavioral responses that would be expected given the differential sensitivities of marine mammal species to sound and the wide range of potential acoustic sources to which a marine mammal may be exposed.

Flight Response

—A flight response is a dramatic change in normal movement to a directed and rapid movement away from the perceived location of a sound source. Relatively little information on flight responses of marine mammals to anthropogenic signals exist, although observations of flight responses to the presence of predators have occurred (Connor and Heithaus, 1996). Flight responses have been speculated as being a component of marine mammal strandings associated with sonar activities (Evans and England, 2001).

Response to Predator

—Evidence suggests that at least some marine mammals have the ability to acoustically identify potential predators. For example, harbor seals that reside in the coastal waters off British Columbia are frequently targeted by certain groups of killer whales, but not others. The seals discriminate between the calls of threatening and non-threatening killer whales (Deecke

et al.,

2002), a capability that should increase survivorship while reducing the energy required for attending to and responding to all killer whale calls. The occurrence of masking or hearing impairment provides a means by which marine mamma

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