[Federal Register Volume 80, Number 106 (Wednesday, June 3, 2015)]
[Proposed Rules]
[Pages 31738-31817]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-13038]



[[Page 31737]]

Vol. 80

Wednesday,

No. 106

June 3, 2015

Part IV





Department of Commerce





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National Oceanic and Atmospheric Administration





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50 CFR Part 218





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

  Federal Register / Vol. 80 , No. 106 / Wednesday, June 3, 2015 / 
Proposed Rules  

[[Page 31738]]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 218

[Docket No. 140109018-5464-01]
RIN 0648-BD89


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

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

ACTION: Proposed rule; request for comments and information.

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SUMMARY: NMFS has received a request from the U.S. Navy (Navy) for 
authorization to take marine mammals incidental to the training and 
testing activities conducted in the Northwest Training and Testing 
(NWTT) study area from November 2015 through November 2020. 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. 
The Navy has also requested that NMFS authorize modifications to 
watchstander requirements for observed behavior of marine mammals 
during Major Training Events (MTEs) in the Hawaii-Southern California 
Training and Testing (HSTT), Atlantic Fleet Training and Testing 
(AFTT), Mariana Islands Training and Testing (MITT), and Gulf of Alaska 
Training (GOA) study areas. Modifications to the Navy watchstander 
requirements would require a revision to regulatory text in current 
regulations governing the taking and importing of marine mammals during 
testing and/or training activities in these study areas. There are no 
MTEs associated with Navy training and testing activities in the NWTT 
study area.

DATES: Comments and information must be received no later than July 17, 
2015.

ADDRESSES: You may submit comments, identified by NOAA-NMFS-2015-0031, 
by any of the following methods:
     Electronic submissions: submit all electronic public 
comments via the Federal eRulemaking Portal, Go to www.regulations.gov/#!docketDetail;D=NOAA-NMFS-2015-0031, click the ``Comment Now!'' icon, 
complete the required fields, and enter or attach your comments.
     Mail: Submit comments to Jolie Harrison, Chief, Permits 
and Conservation Division, Office of Protected Resources, National 
Marine Fisheries Service, 1315 East-West Highway, Silver Spring, MD 
20910-3225.
     Fax: (301) 713-0376; Attn: Jolie Harrison.
    Instructions: Comments sent by any other method, to any other 
address or individual, or received after the end of the comment period, 
may not be considered by NMFS. All comments received are a part of the 
public record and will generally be posted for public viewing on 
www.regulations.gov without change. All personal identifying 
information (e.g., name, address, etc.), confidential business 
information, or otherwise sensitive information submitted voluntarily 
by the sender will be publicly accessible. NMFS will accept anonymous 
comments (enter ``N/A'' in the required fields if you wish to remain 
anonymous). Attachments to electronic comments will be accepted in 
Microsoft Word, Excel, or Adobe PDF file formats only.

FOR FURTHER INFORMATION CONTACT: John Fiorentino, Office of Protected 
Resources, NMFS, (301) 427-8477.

SUPPLEMENTARY INFORMATION: 

Availability

    A copy of the Navy's LOA application, which contains a list of the 
references used in this document, may be obtained by visiting the 
internet at: http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm. The Navy also prepared a Draft Environmental Impact 
Statement (DEIS)/Overseas Environmental Impact Statement (OEIS) to 
assess the environmental impacts associated with ongoing and proposed 
training and testing activities in the NWTT Study Area. The NWTT DEIS/
OEIS was released to the public on January 24, 2014 (79 FR 4158) for 
review until April 15, 2014. On October 24, 2014 (79 FR 63610), the 
Navy published a Notice of Intent (NOI) to prepare a Supplement to the 
January 2014 NWTT DEIS/OEIS. The Supplement was released to the public 
on December 19, 2014 (79 FR 75800) for review until February 2, 2015. 
The Navy is the lead agency for the NWTT EIS/OEIS, and NMFS and the 
U.S. Coast Guard are cooperating agencies pursuant to 40 CFR 1501.6 and 
1508.5. The January 2014 NWTT DEIS/OEIS and the December 2014 
Supplement, which contain a list of the references used in this 
document, may be viewed at: http://www.nwtteis.com. 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) (Public Law 
108-136) removed the ``small numbers'' and ``specified geographical 
region'' limitations indicated above and amended the definition of 
``harassment'' as it applies to a ``military readiness activity'' to 
read as follows (section 3(18)(B) of the MMPA): ``(i) Any act that 
injures or has the significant potential to injure a marine mammal or 
marine mammal stock in the wild [Level A Harassment]; or (ii) any act 
that disturbs or is likely to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of natural behavioral patterns, 
including, but not limited to, migration, surfacing, nursing, breeding, 
feeding, or sheltering, to a point where such behavioral patterns are 
abandoned or significantly altered [Level B Harassment].''

Summary of Request

NWTT Proposed Rule

    On December 18, 2013, NMFS received an application from the Navy 
requesting two LOAs for the take of 26 species of marine mammals 
incidental to Navy training and testing activities to be conducted in 
the NWTT Study Area over 5 years. On September 26, 2014, the Navy 
submitted a revised LOA application to reflect updates to exposure 
estimates based on emergent

[[Page 31739]]

changes to specific types of training activities. The revised 
application also provided an update to the effects analysis for 
Guadalupe fur seals (summarized in the Analysis of Guadalupe Fur Seal 
Exposures section of this proposed rule) to more realistically reflect 
potential impacts from offshore Navy training and testing events. On 
November 7, 2014, the Navy submitted a revised LOA application to 
address: (a) An inadvertent error in the recommended mitigation zone 
for mine countermeasure and neutralization training events; (b) removal 
of the time delay firing underwater explosive training activity; and 
(c) correction or clarification of certain mitigation measures applied 
to testing. On April 2, 2015, the Navy submitted a final revision to 
the LOA application (hereinafter referred to as the LOA application) to 
incorporate and update population density estimates for the Hood Canal 
stock of harbor seals.
    The Navy is requesting separate 5-year LOAs for training and 
testing activities to be conducted from 2015 through 2020. The Study 
Area includes the existing Northwest Training Range Complex, the 
Keyport Range Complex, Carr Inlet Operations Area, Southeast Alaska 
Acoustic Measurement Facility (SEAFAC), and Navy pierside locations 
where sonar maintenance or testing may occur (see Figure 1-1 of the LOA 
application for a map of the NWTT Study Area). The activities conducted 
within the NWTT Study Area are classified as military readiness 
activities. The Navy states that these activities may expose some of 
the marine mammals present within the NWTT Study Area to sound from 
underwater acoustic sources and explosives. The Navy is requesting 
authorization to take 26 marine mammal species by Level B (behavioral) 
harassment; 4 of those marine mammal species may be taken by injury 
(Level A harassment).
    The LOA application and the January 2014 NWTT DEIS/OEIS contain 
proposed acoustic thresholds that were used to evaluate the Navy's AFTT 
and HSTT activities. The thresholds are based on evaluation of recent 
scientific studies; a detailed explanation of how they were derived is 
provided in the Criteria and Thresholds for Navy Acoustic Effects 
Analysis Technical Report (Finneran and Jenkins, 2012). NMFS is 
currently updating and revising all of its acoustic thresholds. Until 
that process is complete, NMFS will continue its long-standing practice 
of considering specific modifications to the acoustic thresholds 
currently employed for incidental take authorizations only after 
providing the public with an opportunity for review and comment. NMFS 
is requesting comments on all aspects of the proposed rule.
Modifications to HSTT, AFTT, MITT, and GOA Final Rules
    The Navy is also requesting that NMFS authorize modifications to 
watchstander requirements, unrelated to implementation of mitigation 
measures, for observed behavior of marine mammals during MTEs in the 
HSTT, AFTT, MITT, and GOA study areas. With these proposed 
modifications the Navy would no longer be required to report individual 
marine mammal sighting information during MTEs when mitigation is not 
occurring in the study area. After 5 years of collecting marine mammal 
sighting data for all animals sighted during MTEs, NMFS and Navy have 
determined that without the ability to obtain species information this 
data set does not provide for any meaningful analysis beyond that which 
may be possible using mitigation-related observations alone. The Navy 
and NMFS have thoroughly investigated several potential uses for the 
data prior to reaching this conclusion. Additionally, this reporting 
requirement places an undue administrative burden on ships watch teams. 
The Navy will continue to collect marine mammal sighting data during 
MTEs for every instance when any form of mitigation is employed such as 
powering down or securing sonar, maneuvering the ship, or delaying an 
event--in other words, in instances where animals are closer to the 
sound source around which mitigation measures are implemented. This 
data is useful in supporting mitigation effectiveness analyses and also 
may be helpful in supporting an understanding of the frequency with 
which marine mammals (generally, not by species) may be encountered or 
detected in close proximity to a particular source (e.g., where the 
likelihood of auditory or other injury is higher). Additionally, the 
Navy will continue to implement their separate Integrated Comprehensive 
Monitoring Program, which includes studies that are specifically 
designed to contribute to our understanding of the animals affected and 
how Navy training and testing impacts them.
    These modifications would be implemented through the revision of 
regulatory text for existing regulations governing the taking of marine 
mammals incidental to testing and/or training activities in HSTT, AFTT, 
MITT, and GOA study areas. Proposed revisions to the regulatory text 
are provided in the regulatory text at the end of this proposed rule. 
Proposed revisions to MITT regulatory text will be made in the MITT 
final rule, which is currently being prepared concurrent with the NWTT 
proposed rule and is expected to publish in the Federal Register prior 
to the NWTT final rule. There are no MTEs or marine mammal sighting 
reporting requirements associated with Navy training and testing 
activities in the NWTT study area.
Background of Request
    The Navy's mission is to maintain, train, and equip combat-ready 
naval forces capable of winning wars, deterring aggression, and 
maintaining freedom of the seas. Section 5062 of Title 10 of the United 
States Code directs the Chief of Naval Operations to train all military 
forces for combat. The Chief of Naval Operations meets that direction, 
in part, by conducting at-sea training exercises and ensuring naval 
forces have access to ranges, operating areas (OPAREAs) and airspace 
where they can develop and maintain skills for wartime missions and 
conduct research, development, testing, and evaluation (RDT&E) of naval 
systems.
    The Navy proposes to continue conducting training and testing 
activities within the NWTT Study Area, which have been ongoing for 
decades with some activities dating back to at least the early 1900s. 
The tempo and types of training and testing activities have fluctuated 
because of the introduction of new technologies, the evolving nature of 
international events, advances in war fighting doctrine and procedures, 
and force structure (organization of ships, submarines, aircraft, 
weapons, and personnel) changes. Such developments influence the 
frequency, duration, intensity, and location of required training and 
testing activities. The Navy analyzed many training and testing 
activities in the Study Area in the Tactical Training Theater 
Assessment and Planning Program Phase I and earlier documents, 
specifically the following environmental planning documents: Northwest 
Training Range Complex Final EIS/OEIS (U.S. Department of the Navy, 
2010a), NAVSEA NUWC Keyport Range Complex Extension Final EIS/OEIS 
(U.S. Department of the Navy, 2010b), and the Final EIS for the 
Southeast Alaska Acoustic Measurement Facility (SEAFAC) (U.S. 
Department of the Navy, 1988). The Navy's LOA request covers training 
and testing activities that would occur for a 5-year period following 
the expiration of the first of the two current MMPA authorizations

[[Page 31740]]

(Northwest Training Range Complex; Keyport Range Complex). The Navy has 
also prepared and released to the public a January 2014 DEIS/OEIS 
analyzing the effects on the human environment of implementing their 
preferred alternative (among others). The January 2014 NWTT DEIS/OEIS 
(which is part of Phase II of the program) accounts for planned 
adjustments to tempo and types of activities dictated by military 
readiness requirements. A NOI to prepare a Supplement to the January 
2014 NWTT DEIS/OEIS was published on October 24, 2014 and the draft 
Supplement was released to the public on December 19, 2014. The 
Supplement focused on changes to the Proposed Action due to updated 
training requirements and significant new information relevant to 
environmental concerns per 40 CFR 1502.9.
    The Navy's LOA application differs from the January 2014 NWTT DEIS/
OEIS in that it contains updated information on the Washington Inland 
Waters stocks of harbor seals (Carretta et al., 2014) and their 
abundance in Hood Canal based on a new application of London et al. 
(2012). The January 2014 NWTT DEIS/OEIS analysis relied on NMFS' Stock 
Assessment Reports (SARs) through 2013 (Carretta et al., 2014), which 
did not incorporate the London et al. findings. London et al. (2012) 
reported the variability of harbor seal haulout behavior in a sub-
portion of Hood Canal, covering 5 months of the year (July-November). 
The paper provided a range of haulout probabilities in Hood Canal that 
differed from the single value (65 percent--Huber et al., 2001) 
previously used by NMFS and Navy to calculate harbor seal abundance. 
Recently, in discussions between the Navy and NMFS it was determined 
that it is now appropriate to incorporate London et al. (2012) for the 
Hood Canal stock only. This resulted in increasing the population 
estimate of the Hood Canal stock of harbor seals by a factor of 
approximately 3.26, resulting in a new abundance estimate of 3,555. In 
addition, in calculating its exposure estimates, the Navy also applied 
the haulout probability of 20 percent derived from London et al. (2012) 
which changed the percentage of harbor seals in the water from 35 
percent (Huber et al., 2001) to 80 percent. These changes in 
assumptions result in a corresponding increase in estimated exposures 
because the Navy is assuming that there are more harbor seals present 
in Hood Canal and more of the animals will be in the water at any given 
time compared to the analysis presented in the January 2014 NWTT DEIS/
OEIS. The result of these changes in the best available science is that 
the Navy has estimated additional Level A and Level B takes for 
training and testing activities per year. These changes to the 
estimates presented in the January 2014 NWTT DEIS/OEIS do not reflect a 
change in the Navy's proposed action nor a significant change to Navy's 
methodology. The vast majority of the increased exposure estimates are 
Level B harassment exposures that derive from the Navy's already 
conservative acoustic effects model. The Navy has determined that these 
Level A and Level B harassment exposures are not biologically 
significant to the population because (1) none of the estimated 
exposures result in mortality; (2) the monitoring and mitigations 
employed would likely reduce the severity of Level A exposures; (3) 
there are no indications that the historically occurring activities 
resulting in these behavioral harassment exposures are having any 
effect on this population's survival by altering behavior patterns such 
as breeding, nursing, feeding, or sheltering; (4) the population has 
been stable and likely at carrying capacity (Jeffries et al., 2003); 
(5) the population continues to use known large haulouts in Hood Canal 
and Dabob Bay that are adjacent to Navy testing and training 
activities; (6) the population continues to use known haulouts for 
pupping; and (7) the population continues to use the waters in and 
around Dabob Bay and Hood Canal. As such, the Navy has determined, and 
NMFS concurs, that it is not necessary to supplement the January 2014 
NWTT DEIS/OEIS analysis as this information is not new significant 
information to the environmental impacts. However, the Navy has advised 
NMFS that all comments received on the proposed rule that address the 
changes in take estimates for the Hood Canal stock of harbor seals will 
be addressed by the Navy in its Final EIS/OEIS for NWTT.

Description of the Specified Activity

    The Navy is requesting authorization to take marine mammals 
incidental to conducting training and testing activities. The Navy has 
determined that sonar use and underwater detonations 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 January 2014 NWTT DEIS/OEIS and in the LOA application 
(http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm) and are 
summarized here.

Overview of Training Activities

    The Navy routinely trains in the NWTT Study Area in preparation for 
national defense missions. Training activities and exercises covered in 
the Navy's LOA request are briefly described below, and in more detail 
within Chapter 2 of the January 2014 NWTT DEIS/OEIS. Training 
activities are categorized into eight functional warfare areas (anti-
air warfare; amphibious warfare; strike warfare; anti-surface warfare; 
anti-submarine warfare; electronic warfare; mine warfare; and naval 
special warfare). The Navy determined that the following stressors used 
in these warfare areas are most likely to result in impacts on marine 
mammals:

 Anti-surface warfare (impulsive sources [underwater 
detonations])
 Anti-submarine warfare (non-impulsive sources [active sonar], 
impulsive underwater detonations)
 Mine warfare (non-impulsive sources, impulsive underwater 
detonations)

    The Navy's activities in anti-air warfare, electronic warfare, and 
naval special warfare do not involve stressors that could result in 
harassment of marine mammals. Therefore, these activities are not 
discussed further. The analysis and rationale for excluding these 
warfare areas is contained in the January 2014 DEIS/OEIS.

Anti-Surface Warfare

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

Anti-Submarine Warfare

    The mission of anti-submarine warfare (ASW) 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

[[Page 31741]]

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.

Other Activities

    Other activities include pierside and at-sea maintenance of 
submarine and surface ship sonar systems.

Overview of Testing Activities

    Testing activities covered in the Navy's LOA request are briefly 
described below, and in more detail within Chapter 2 of the January 
2014 NWTT DEIS/OEIS. The Navy researches, develops, tests, and 
evaluates new platforms, systems and technologies. Many tests are 
conducted in realistic conditions at sea, and can range in scale from 
testing new software to operating portable devices to conducting tests 
of live weapons (such as the Service Weapon Test of a torpedo) to 
ensure they function as intended. Testing activities may occur 
independently of or in conjunction with training activities.
    Many testing activities are conducted similarly to Navy training 
activities and are also categorized under one of the primary mission 
areas described above. Other testing activities are unique and are 
described within their specific testing categories. Because each test 
is conducted by a specific component of the Navy's research and 
acquisition community, which includes the Navy's Systems Commands and 
the Navy's scientific research organizations, the testing activities 
described in the LOA application are organized first by that particular 
organization as described below and in the order as presented.
    The Navy describes and analyzes the effects of its testing 
activities within the 2014 NWTT DEIS/OEIS. In its assessment, the Navy 
concluded that acoustic stressors from the use of underwater acoustic 
sources and underwater detonations resulted in impacts on marine 
mammals that rose to the level of harassment as defined under the MMPA. 
Therefore, the LOA application for NWTT provides the Navy's assessment 
of potential effects from these stressors in terms of the various 
activities in which they would be used.
    The individual commands within the research and acquisition 
community included in the NWTT DEIS/OEIS and in the LOA application 
are:

     Naval Sea Systems Command (NAVSEA). Within NAVSEA are the 
following field activities:
[cir] Naval Undersea Warfare Center (NUWC) Division, Keyport
[cir] Naval Surface Warfare Center, Carderock Division (NSWCCD), 
Detachment Puget Sound
[cir] NSWCCD Southeast Alaska Acoustic Measurement Facility (SEAFAC)
[cir] Puget Sound Naval Shipyard and Intermediate Maintenance Facility
[cir] Various NAVSEA program offices
     Naval Air Systems Command (NAVAIR)

Naval Sea Systems Command Testing Events

    NAVSEA is responsible for engineering, building, buying, and 
maintaining the Navy's ships and submarines and associated combat 
systems. NAVSEA is broken up into two types of warfare centers: NUWC 
and the Naval Surface Warfare Center (NSWC).
    NUWC provides Fleet readiness support for submarines, surface 
ships, torpedoes, mines, land attack systems, and Fleet training 
systems. NAVSEA has several field activities operating out of Naval 
Base (NAVBASE) Kitsap, including NUWC Division Keyport, NSWCCD 
Detachment Puget Sound, and Puget Sound Naval Shipyard and Intermediate 
Maintenance Facility. NSWCCD Detachment Puget Sound also operates the 
SEAFAC facility in Alaska.
    Each major category of NAVSEA activities in the Study Area is 
represented below. NUWC Division, Keyport and NSWCCD Detachment Puget 
Sound activities are grouped together in the discussion below to 
simplify review due to the diversity of activity types and locations 
they work in. Puget Sound Naval Shipyard and Intermediate Facility 
activities are grouped with the general activities conducted by NAVSEA. 
Numerous test activities and technical evaluations, in support of 
NAVSEA's systems development mission, often occur in conjunction with 
fleet activities within the Study Area.

Naval Undersea Warfare Center Division, Keyport Testing Activities

    NUWC Division Keyport's mission is to provide test and evaluation 
services and expertise to support the Navy's evolving manned and 
unmanned vehicle program activities. NUWC Keyport has historically 
provided facilities and capabilities to support testing of torpedoes, 
other unmanned vehicles, submarine readiness, diver training, and 
similar activities that are critical to the success of undersea 
warfare. Range support requirements for such activities include 
testing, training, and evaluation of system capabilities such as 
guidance, control, and sensor accuracy in multiple marine environments 
(e.g., differing depths, salinity levels, sea states) and in surrogate 
and simulated war-fighting environments. Technological advancements in 
the materials, instrumentation, guidance systems, and tactical 
capabilities of manned and unmanned vehicles continue to evolve in 
parallel with emerging national security priorities and threat 
assessments. However, NUWC Keyport does not utilize explosives in any 
testing scenarios.

Naval Surface Warfare Center, Carderock Division

    NSWCCD includes two organizations that conduct testing activities: 
NSWCCD, Detachment Puget Sound and NSWCCD SEAFAC. Detachment Puget 
Sound testing activities are aligned with its mission to provide 
research, development, test, and evaluation (RDT&E), analysis, 
acquisition support, in-service engineering, logistics and integration 
of surface and undersea vehicles and associated systems; develop and 
apply science and technology associated with naval architecture and 
marine engineering; and provide support to the maritime industry. 
Activities and support include engineering, technical, operations, 
diving, and logistics required for the RDT&E associated with:

 Advanced Technology Concepts, Engineering and Proofing

[[Page 31742]]

 Experimental Underwater Vehicles, Systems, Subsystems and 
Components
 Specialized Underwater Systems, Equipment, Tools and Hardware
 Acoustic Data Acquisition, Analysis and Measurement Systems 
(required to measure U.S. Navy Acoustic Signatures).

    These activities can be broken down into four major testing 
categories to include: System, Subsystem and Component Acoustic Testing 
Pierside; Performance Testing at Sea; Development Testing and Training; 
and Proof of Concept Testing.
    NSWCCD SEAFAC makes high fidelity directive volumetric and line 
arrays passive acoustic signature measurements. The SEAFAC site 
includes directive line arrays and data collection and processing 
systems for real-time data analysis and signature evaluation.
    SEAFAC provides the capability to perform RDT&E analyses to 
determine the sources of radiated acoustic noise, to assess 
vulnerability, and to develop quieting measures. Unforeseen emergent 
Navy requirements may influence actual testing activities during the 
time period under consideration. Testing activities that would occur at 
SEAFAC are identified to the extent practicable throughout this 
application.

Naval Sea Systems Command Program Office Sponsored Testing Activities

    NAVSEA also conducts tests that are not associated with NUWC 
Keyport or NSWCCD. Activities are conducted at Navy piers at NAVBASE 
Kitsap, Bremerton; NAVBASE Kitsap, Bangor; and Naval Station Everett; 
and in conjunction with fleet activities off the coast of Washington, 
Oregon, and northern California. Tests within this category include, 
but are not limited to, Life Cycle Activities, Shipboard Protection 
Systems and Swimmer Defense Testing, Unmanned Vehicle Testing, ASUW/ASW 
Testing, and New Ship Construction.

Naval Air Systems Command Testing Events

    NAVAIR testing events generally fall into the primary mission areas 
used by the fleets. NAVAIR events include, but are not limited to, the 
testing of new aircraft platforms, weapons, and systems before those 
platforms, weapons and systems are integrated into the fleet. In this 
application, NAVAIR testing activities are limited to ASW testing of 
sonobuoys. The sonobuoys tested include both passive and active non-
impulsive, sonobuoys using impulsive sources, and high duty cycle 
sonobuoys.

Description of 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 LOA 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 Active Acoustic 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. Sources of sonar and 
other active acoustic sources include surface ship sonar, sonobuoys, 
torpedoes, range pingers, and unmanned underwater vehicles.

Ordnance and Munitions

    Most ordnance and munitions used during training and testing events 
fall into three basic categories: projectiles (such as gun rounds), 
missiles (including rockets), and bombs. Ordnance can be further 
defined by their net explosive weight, which considers the type and 
quantity of the explosive substance without the packaging, casings, 
bullets, etc. Net explosive weight (NEW) is the trinitrotoluene (TNT) 
equivalent of energetic material, which is the standard measure of 
strength of bombs and other explosives. For example, a 12.7-centimeter 
(cm) shell fired from a Navy gun is analyzed at about 9.5 pounds (lb) 
(4.3 kilograms (kg)) of NEW. The Navy also uses non-explosive ordnance 
in place of high explosive ordnance in many training and testing 
events. Non-explosive ordnance munitions look and perform similarly to 
high explosive ordnance, but lack the main explosive charge.

Defense Countermeasures

    Naval forces depend on effective defensive countermeasures to 
protect themselves against missile and torpedo attack. Defensive 
countermeasures are devices designed to confuse, distract, and confound 
precision guided munitions. Defensive countermeasures analyzed in the 
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 to 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.
     Airborne Laser Mine Detection Systems. Airborne laser 
detection systems work in concert with neutralization systems. The 
detection system initially locates mines and a neutralization system is 
then used to relocate and neutralize the mine.

[[Page 31743]]

     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 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. Mine neutralization 
systems can clear individual mines or a large number of mines quickly. 
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.
     Towed mechanical mine sweeping systems.These systems tow a 
sweep wire to snag the line that attaches a moored mine to its anchor 
and then uses a series of cables and cutters to sever those lines. Once 
these lines are cut, the mines float to the surface where Navy 
personnel can neutralize the mines.
     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.
     Projectiles. Small- and medium-caliber projectiles, fired 
from surface ships or hovering helicopters, are used to neutralize 
floating and near-surface mines.
     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.
    Explosive charges are used during mine neutralization system 
training activities; however, only non-explosive mines or mine shapes 
would be used.
Classification of Non-Impulsive and Impulsive Sources Analyzed
    In order to better organize and facilitate the analysis of about 
300 sources of underwater non-impulsive sound or impulsive energy, the 
Navy developed a series of source classifications, or source bins. This 
method of analysis provides the following benefits:
     Allows for new sources to be covered under existing 
authorizations, as long as those sources fall within the parameters of 
a ``bin;''
     Simplifies the data collection and reporting requirements 
anticipated under the MMPA;
     Ensures a conservative approach to all impact analysis 
because all sources in a single bin are modeled as the loudest source 
(e.g., lowest frequency, highest source level, longest duty cycle, or 
largest net explosive weight within that bin);
     Allows analysis to be conducted more efficiently, without 
compromising the results;
     Provides a framework to support the reallocation of source 
usage (hours/explosives) between different source bins, as long as the 
total number and severity of marine mammal takes remain within the 
overall analyzed and authorized limits. This flexibility is required to 
support evolving Navy training and testing requirements, which are 
linked to real world events.
    A description of each source classification is provided in Tables 
1-3. 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:

[cir] Low-frequency sources operate below 1 kilohertz (kHz)
[cir] Mid-frequency sources operate at or above 1 kHz, up to and 
including 10 kHz
[cir] High-frequency sources operate above 10 kHz, up to and including 
100 kHz
[cir] Very high-frequency sources operate above 100 kHz, but below 200 
kHz

     Source level of the non-impulsive source:

[cir] Greater than 160 decibels (dB), but less than 180 dB
[cir] Equal to 180 dB and up to 200 dB
[cir] Greater than 200 dB
    How a sensor is used determines how the sensor's acoustic emissions 
are 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 1-4 of the LOA application and in the January 2014 NWTT DEIS/
OEIS. These sources generally meet the following criteria:

 Acoustic sources with frequencies greater than 200 kHz (based 
on known marine mammal hearing ranges)
 Sources with source levels less than 160 dB

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


[[Page 31744]]


         Table 2--Non-Impulsive Training Source Classes Analyzed
------------------------------------------------------------------------
      Source class category        Source class        Description
------------------------------------------------------------------------
Mid-Frequency (MF): Tactical and  MF1..........  Active hull-mounted
 non-tactical sources that                        surface ship sonar
 produce mid-frequency (1 to 10                   (e.g., AN/SQS-53C and
 kHz) signals.                                    AN/SQS-60).
                                  MF3..........  Active hull-mounted
                                                  submarine sonar (e.g.,
                                                  AN/BQQ-10).
                                  MF4..........  Active helicopter-
                                                  deployed dipping sonar
                                                  (e.g., AN/AQS-22 and
                                                  AN/AQS-13).
                                  MF5..........  Active acoustic
                                                  sonobuoys (e.g., AN/
                                                  SSQ-62 DICASS\2\).
                                  MF11.........  Hull-mounted surface
                                                  ship sonar with an
                                                  active duty cycle
                                                  greater than 80%.
High-Frequency (HF) and Very      HF1..........  Active hull-mounted
 High-Frequency (VHF): Tactical   HF4..........   submarine sonar (e.g.,
 and non-tactical sources that                    AN/BQQ-15).
 produce high-frequency (greater                 Active mine detection,
 than 10 kHz but less than 200                    classification, and
 kHz) signals.                                    neutralization sonar
                                                  (e.g., AN/SQS-20).
                                  HF6..........  Active sources (equal
                                                  to 180 dB and up to
                                                  200 dB).
Anti-Submarine Warfare (ASW):     ASW2.........  MF active Multistatic
 Tactical sources such as active  ASW3.........   Active Coherent (MAC)
 sonobuoys and acoustic                           sonobuoy (e.g., AN/SSQ-
 countermeasures systems used                     125).
 during ASW training activities.                 MF active towed active
                                                  acoustic
                                                  countermeasure systems
                                                  (e.g., AN/SLQ-25
                                                  NIXIE).
------------------------------------------------------------------------


         Table 3--Non-Impulsive Testing Source Classes Analyzed
------------------------------------------------------------------------
      Source class category        Source class        Description
------------------------------------------------------------------------
Low-Frequency (LF): Sources that  LF4..........  Low-frequency sources
 produce low-frequency (less      LF5..........   equal to 180 dB and up
 than 1 kilohertz [kHz]) signals.                 to 200 dB.
                                                 Low-frequency sources
                                                  less than 180 dB.
Mid-Frequency (MF): Tactical and  MF3..........  Hull-mounted submarine
 non-tactical sources that        MF4..........   sonar (e.g., AN/BQQ-
 produce mid-frequency (1 to 10                   10).
 kHz) signals.                                   Helicopter-deployed
                                                  dipping sonar (e.g.,
                                                  AN/AQS-22 and AN/AQS-
                                                  13).
                                  MF5..........  Active acoustic
                                                  sonobuoys (e.g.,
                                                  DICASS).
                                  MF6..........  Active underwater sound
                                                  signal devices (e.g.,
                                                  MK-84).
                                  MF8..........  Active sources (greater
                                                  than 200 dB).
                                  MF9..........  Active sources (equal
                                                  to 180 dB and up to
                                                  200 dB).
                                  MF10.........  Active sources (greater
                                                  than 160 dB, but less
                                                  than 180 dB) not
                                                  otherwise binned.
                                  MF11.........  Hull-mounted surface
                                                  ship sonar with an
                                                  active duty cycle
                                                  greater than 80%.
                                  MF12.........  High duty cycle--
                                                  variable depth sonar.
High-Frequency (HF) and Very      HF1..........  Hull-mounted submarine
 High-Frequency (VHF): Tactical   HF3..........   sonar (e.g., AN/BQQ-
 and non-tactical sources that    HF5 \1\......   10).
 produce high-frequency (greater                 Hull-mounted submarine
 than 10 kHz but less than 200                    sonar (classified).
 kHz) signals.                                   Active sources (greater
                                                  than 200 dB).
                                  HF6..........  Active sources (equal
                                                  to 180 dB and up to
                                                  200 dB).
                                  VHF2.........  Active sources with a
                                                  frequency greater than
                                                  100 kHz, up to 200 kHz
                                                  with a source level
                                                  less than 200 dB.
Anti-Submarine Warfare (ASW):     ASW1.........  Mid-frequency Deep
 Tactical sources such as active  ASW2.........   Water Active
 sonobuoys and acoustic                           Distributed System
 countermeasures systems used                     (DWADS).
 during the conduct of ASW                       Mid-frequency
 testing activities.                              Multistatic Active
                                                  Coherent sonobuoy
                                                  (e.g., AN/SSQ-125)--
                                                  sources analyzed by
                                                  number of items
                                                  (sonobuoys).
                                  ASW2.........  Mid-frequency sonobuoy
                                                  (e.g., high duty
                                                  cycle)--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  TORP1........  Lightweight torpedo
 associated with the active       TORP2........   (e.g., MK-46, MK-54).
 acoustic signals produced by                    Heavyweight torpedo
 torpedoes.                                       (e.g., MK-48, electric
                                                  vehicles).
Acoustic Modems (M): Systems      M3...........  Mid-frequency acoustic
 used to transmit data                            modems (greater than
 acoustically through water.                      190 dB) (e.g.,
                                                  Underwater Emergency
                                                  Warning System, Aid to
                                                  Navigation).
Swimmer Detection Sonar (SD):     SD1..........  High-frequency sources
 Systems used to detect divers                    with short pulse
 and submerged swimmers.                          lengths, used for the
                                                  detection of swimmers
                                                  and other objects for
                                                  the purpose of port
                                                  security.
Synthetic Aperture Sonar (SAS):   SAS2.........  High frequency unmanned
 Sonar in which active acoustic                   underwater vehicle
 signals are post-processed to                    (UUV) (e.g., UUV
 form high-resolution images of                   payloads).
 the seafloor.
------------------------------------------------------------------------
Notes: \1\ For this analysis, HF5 consists of only one source; the
  modeling was conducted specifically for that source.
\2\ DICASS = Directional Command Activated Sonobuoy System Proposed
  Action.


[[Page 31745]]

Training and Testing

    The training and testing activities that the Navy proposes to 
conduct in the NWTT Study Area are listed in Tables 4-6. Detailed 
information about each proposed activity (stressor, training or testing 
event, description, sound source, duration, and geographic location) 
can be found in the LOA application and in Appendix A of the January 
2014 NWTT DEIS/OEIS. NMFS used the detailed information in the LOA 
application and in Appendix A of the January 2014 NWTT DEIS/OEIS to 
analyze the potential impacts from training and testing activities on 
marine mammals. The Navy's proposed activities are anticipated to meet 
training and testing needs in the years 2015-2020.

Summary of Impulsive and Non-Impulsive Sources

    Table 4 provides a quantitative annual summary of training 
activities by sonar and other active acoustic source class analyzed in 
the Navy's LOA request.

  Table 4--Annual Hours of Sonar and Other Active Acoustic Sources Used
               During Training Within the NWTT Study Area
------------------------------------------------------------------------
      Source class  category         Source class        Annual use
------------------------------------------------------------------------
Mid-Frequency (MF) Active sources  MF1............  166 hours.
 from 1 to 10 kHz.                 MF3............  70 hours.
                                   MF4............  4 hours.
                                   MF5............  896 items.
                                   MF11...........  16 hours.
High-Frequency (HF) Tactical and   HF1............  48 hours.
 non-tactical sources that         HF4............  384 hours.
 produce signals greater than 10   HF6............  192 hours.
 kHz but less than 100 kHz.
Anti-Submarine Warfare (ASW).....  ASW2...........  720 items.
                                   ASW3...........  78 hours.
------------------------------------------------------------------------

    Table 5 provides a quantitative annual summary of testing 
activities by sonar and other active sources analyzed in the Navy's LOA 
request.

  Table 5--Annual Hours of Sonar and Other Active Acoustic Sources Used
                During Testing Within the NWTT Study Area
------------------------------------------------------------------------
      Source class category          Source class        Annual use
------------------------------------------------------------------------
Low-Frequency (LF): Sources that   LF4............  110 hours.
 produce signals less than 1 kHz.  LF5............  71 hours.
Mid-Frequency (MF): Tactical and   MF3............  161 hours.
 non-tactical sources that         MF4............  10 hours.
 produce signals from 1 to 10 kHz. MF5............  273 items.
                                   MF6............  12 items.
                                   MF8............  40 hours.
                                   MF9............  1,183 hours.
                                   MF10...........  1,156 hours.
                                   MF11...........  34 hours.
                                   MF12...........  24 hours.
High-Frequency (HF) and Very High- HF1............  161 hours.
 Frequency (VHF): Tactical and     HF3............  145 hours.
 non-tactical sources that         HF5 \1\........  360 hours.
 produce signals greater than 10   HF6............  2,099 hours.
 kHz but less than 200 kHz.
Very High-Frequency (VHF):         VHF2...........  35 hours.
 Tactical and non-tactical
 sources that produce signals
 greater than 100 kHz but less
 than 200 kHz.
Anti-Submarine Warfare (ASW):      ASW1...........  16 hours.
 Tactical sources used during ASW  ASW2 \2\.......  64 hours.
 training and testing activities.  ASW2 \2\.......  170 items.
                                   ASW3...........  444 hours.
                                   ASW4...........  1,182 hours.
Torpedoes (TORP): Source classes   TORP1..........  315 items.
 associated with active acoustic   TORP2..........  299 items.
 signals produced by torpedoes.
Acoustic Modems (M): Transmit      M3.............  1,519 hours.
 data acoustically through the
 water.
Swimmer Detection Sonar (SD):      SD1............  757 hours.
 Used to detect divers and
 submerged swimmers.
Synthetic Aperture Sonar (SAS):    SAS2...........  798 hours.
 Sonar in which active acoustic
 signals are post-processed to
 form high-resolution images of
 the seafloor.
------------------------------------------------------------------------
\1\ For this analysis, HF5 consists of only one source; the modeling was
  conducted specifically for that source.
\2\ The ASW2 bin contains sources that are analyzed by hours and some
  that are analyzed by count of items. There is no overlap of the
  numbers in the two rows.

    Table 6 provides a quantitative annual summary of training 
explosive source classes analyzed in the Navy's LOA request.

[[Page 31746]]



 Table 6--Proposed Annual Number of Impulsive Source Detonations During
                     Training in the NWTT Study Area
------------------------------------------------------------------------
                                                        Annual in-water
        Explosive class          Net explosive weight     detonations
                                        (NEW)              (training)
------------------------------------------------------------------------
E1............................  (0.1 lb.-0.25 lb.)...                 48
E3............................  (>0.5 lb.-2.5 lb.)...                  6
E5............................  (>5 lb.-10 lb.)......                 80
E10...........................  (>250 lb.-500 lb.)...                  4
E12...........................  (>650 lb.-1000 lb.)..                 10
------------------------------------------------------------------------

    Table 7 provides a quantitative annual summary of testing explosive 
source classes analyzed in the Navy's LOA request.

 Table 7--Proposed Annual Number of Impulsive Source Detonations During
                     Testing in the NWTT Study Area
------------------------------------------------------------------------
                                                        Annual In-Water
        Explosive class          Net explosive weight     Detonations
                                        (NEW)              (testing)
------------------------------------------------------------------------
E3............................  (>0.5 lb.-2.5 lb.)...                 72
E4............................  (>2.5 lb.-5 lb.).....                 70
E8............................  (>60 lb.-100 lb.)....                  3
E11...........................  (>500 lb.-650 lb.)...                  3
------------------------------------------------------------------------

Other Stressors--Vessel Strikes

    In addition to potential impacts to marine mammals from activities 
using explosives or sonar and other active acoustic sources, the Navy 
also considered ship strike impacts to marine mammals. The Navy 
assessed that no additional stressors would result in a take and 
require authorization under the MMPA.
    Vessel strikes may occur from surface operations and sub-surface 
operations (excluding bottom crawling, unmanned underwater vehicles). 
Vessels used as part of the Navy's proposed NWTT training and testing 
activities (proposed action) include ships, submarines and boats 
ranging in size from small, 16-foot (ft.) (5-meter [m]) rigid hull 
inflatable boats to aircraft carriers with lengths up to 1,092 ft. (333 
m). Representative Navy vessel types, lengths, and speeds used in both 
training and testing activities are shown in Table 8.

                             Table 8--Representative Navy Vessel Types, Lengths, and Speeds Used Within the NWTT Study Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
             Vessel type                     Example(s)                         Length                    Typical operating speed         Max speed
--------------------------------------------------------------------------------------------------------------------------------------------------------
Aircraft Carrier....................  Aircraft Carrier.......  >900 ft (>300 m)........................  10-15 knots..............  30+ knots
Surface Combatants..................  Cruisers, Destroyers,    330-660 ft (100-200 m)..................  10-15 knots..............  30+ knots
                                       Frigates, Littoral
                                       Combat Ships.
Support Craft/Other.................  Range Support Craft,     16-250 ft (5-80 m)......................  Variable.................  20 knots
                                       Combat Rubber Raiding
                                       Craft, Landing Craft,
                                       Utility; Submarine
                                       Tenders, Yard Patrol
                                       Craft, Protection
                                       Vessels, Barge.
Support Craft/Other--Specialized      Patrol Coastal Ships,    33-130 ft (10-40 m).....................  Variable.................  50+ knots
 High Speed.                           Patrol Boats, Rigid
                                       Hull Inflatable Boat,
                                       High Speed Protection
                                       Vessels.
Submarines..........................  Fleet Ballistic Missile  330-660 ft (100-200 m)..................  8-13 knots...............  20+ knots
                                       Submarines, Attack
                                       Submarines, Guided
                                       Missile Submarines.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Large Navy ships greater than 65 ft. (20 m) generally operate at 
speeds in the range of 10-15 knots for fuel conservation when cruising. 
Submarines generally operate at speeds in the range of 8-13 knots 
during transit and slower for certain tactical maneuvers. Small craft 
(for purposes of this discussion less than 65 ft. [20 m] in length) 
have much more variable speeds, dependent on the mission. While these 
speeds are representative, some vessels operate outside of these speeds 
due to unique training or safety requirements for a given event. 
Examples include increased speeds needed for flight operations, full 
speed runs to test engineering equipment, time critical positioning 
needs, etc. Examples of decreased speeds include speeds less than 5 
knots or completely stopped for launching small boats, certain tactical 
maneuvers, target launch or retrievals, etc.
    The number of Navy vessels in the Study Area varies based on 
training and testing schedules. Most activities include either one or 
two vessels, with an average of one vessel per activity, and last from 
a few hours up to 2 weeks. Vessel movement and the use of in-water 
devices as part of the proposed action would be concentrated in certain

[[Page 31747]]

portions of the Study Area (such as Western Behm Canal [Alaska] or Hood 
Canal in the inland waters portion of the Study Area) but may occur 
anywhere within the Study Area.
    The Navy is analyzing the potential environmental impacts of 
approximately 226 ongoing annual Maritime Security Operations events in 
Puget Sound and the Strait of Juan de Fuca. These critical events have 
been occurring since 2006 and exercise the Navy's Transit Protection 
System, where up to nine escort vessels provide protection during all 
nuclear ballistic missile submarine (SSBN) transits between the 
vessel's homeport and the dive/surface point in the Strait of Juan de 
Fuca or Dabob Bay. During a Transit Protection System event, the 
security escorts enforce a moving 1,000 yard security zone around the 
SSBN to prevent other vessels from approaching while the SSBN is in 
transit on the surface. These events include security escort vessels, 
U.S. Coast Guard personnel and their ancillary equipment and weapons 
systems. The Transit Protection System involves the movement of 
security vessels and also includes periodic exercises and firearms 
training (with blank rounds). Given the relative slow speed of the 
escorted and blocking vessels and multiple lookouts, no marine mammal 
vessel strikes are expected as a result of these events.
    Navy policy (Chief of Naval Operations Instruction 3100.6H) 
requires Navy vessels to report all whale strikes. That information is 
collected by the Office of the Chief of Naval Operations Energy and 
Environmental Readiness Division (OPNAV N45) and cumulatively provided 
to NMFS on an annual basis. In addition, the Navy and NMFS also have 
standardized regional reporting protocols for communicating to regional 
NMFS stranding coordinators information on any Navy vessel strikes as 
soon as possible. These communication procedures will remain in place 
for the duration of the LOAs. There are no records of any Navy vessel 
strikes to marine mammals during training or testing activities in the 
NWTT Study Area.

Duration and Location

    Training and testing activities would be conducted in the Study 
Area throughout the year from November 2015 through November 2020.
    The Study Area is composed of established maritime operating and 
warning areas in the eastern North Pacific Ocean region, including 
areas of the Strait of Juan de Fuca, Puget Sound, and Western Behm 
Canal in southeastern Alaska. The Study Area includes air and water 
space within and outside Washington state waters, and outside state 
waters of Oregon and Northern California. The Study Area includes four 
existing range complexes and facilities: The Northwest Training Range 
Complex (NWTRC), the Keyport Range Complex, Carr Inlet Operations Area, 
and SEAFAC. In addition to these range complexes, the Study Area also 
includes Navy pierside locations where sonar maintenance and testing 
occurs as part of overhaul, modernization, maintenance and repair 
activities at NAVBASE Kitsap, Bremerton; NAVBASE Kitsap, Bangor; and 
Naval Station Everett.
    A range complex is a designated set of specifically bounded 
geographic areas and encompasses a water component (above and below the 
surface), and may encompass airspace and a land component where 
training and testing of military platforms, tactics, munitions, 
explosives, and EW systems occurs. Range complexes include established 
OPAREAs, Restricted Areas, and special use airspace (SUA), which may be 
further divided to provide better control of the area and events for 
safety reasons. These designations are further described in Chapter 2 
of the LOA application.
    The Study Area includes only the at-sea components of the training 
and testing areas and facilities. The Navy is using ``at-sea'' to cover 
activity in, on, and over the water, but not activity on or over the 
land, which may include activities in the surf zone or supported from 
shore-side locations.
    Military activities in the Study Area occur (1) on the ocean 
surface, (2) beneath the ocean surface, and (3) in the air. To aid in 
the description of the ranges covered in the January 2014 NWTT DEIS/
OEIS, the ranges are divided into three distinct geographic and 
functional subdivisions. All of the training and testing activities 
proposed in this application would occur in one or more of these three 
range subdivisions:

 The Offshore Area
 The Inland Waters
 Western Behm Canal, Alaska

Offshore Area

    The Offshore Area of the Study Area includes air, surface, and 
subsurface OPAREAs extending generally west from the coastline of 
Washington, Oregon, and Northern California for a distance of 
approximately 250 nm into international waters. The eastern boundary of 
the Offshore Area is 12 nm off the coastline for most of the Study 
Area, including southern Washington, Oregon, and Northern California. 
The Offshore Area includes the ocean all the way to the coastline only 
along the Washington coast beneath the airspace of W-237 and the 
Olympic Military Operations Area (MOA) and the Washington coastline 
north of the Olympic MOA. The components of the Offshore Area are 
described below.

Airspace

    The SUA in the Offshore Area is comprised of Warning Area 237 (W-
237), which extends westward off the coast of Northern Washington State 
and is divided into nine sub-areas (A-H, and J). The eastern boundary 
of W-237 lies 3 nm off the coast of Washington. The floor of W-237 
extends to the ocean surface and the ceiling of the airspace varies 
between 27,000 ft. (8,200 m) in areas E, H, and J; 50,000 ft. (15,200 
m) in areas A and B; and unlimited in areas C, D, F, and G, with a 
total area of 25,331 square nautical miles (nm\2\).
    The Olympic MOA overlays both land (the Olympic Peninsula) and sea 
(extending to 3 nm off the coast of Washington into the Pacific Ocean). 
The MOA lower limit is 6,000 ft. (1,800 m) above mean sea level but not 
below 1,200 ft. above ground level, and the upper limit is up to, but 
not including, 18,000 ft. (5,500 m), with a total area coverage of 
1,614 nm\2\.
    Above the Olympic MOA is the Olympic Air Traffic Controlled 
Assigned Airspace (ATCAA), which has a floor coinciding with the 
Olympic MOA ceiling. The ATCAA has an upper limit of 35,000 ft. (10,700 
m).

For the LOA application, the Olympic MOA and the Olympic ATCAA Are 
components of the Offshore Area

Inland Waters

    The Inland Waters includes air, sea, and undersea space inland of 
the coastline, from buoy ``J'' at 48[deg] 29.6' N, 125[deg] W, eastward 
to include all waters of the Strait of Juan de Fuca and the Puget 
Sound. None of this area extends into Oregon or California. Within the 
Inland Waters are specific geographic components in which training and 
testing occur. The Inland Waters and its component areas are described 
below.

Airspace

    Restricted Area 6701 (R-6701, Admiralty Bay) is a Restricted Area 
over Admiralty Bay, Washington with a lower limit at the ocean surface 
and an upper limit of 5,000 ft. This airspace covers a total area of 56 
nm\2\.
    Chinook A and B MOAs are 56 nm\2\ of airspace south and west of 
Admiralty Bay. The Chinook MOAs extend from 300 ft. to 5,000 ft. above 
the ocean surface.

[[Page 31748]]

Sea and Undersea Space

    Explosive Ordnance Disposal Underwater Ranges--Two active EOD 
ranges are located in the Inland Waters at the following locations:
     Hood Canal EOD Training Range
     Crescent Harbor EOD Training Range
    Surface and Subsurface Testing Sites--There are three 
geographically distinct range sites in the Inland Waters where the Navy 
conducts surface and subsurface testing and some limited training. The 
Keyport Range Site is located in Kitsap County and includes portions of 
Liberty Bay and Port Orchard Reach (also known as Port Orchard 
Narrows). The Dabob Bay Range Complex (DBRC) Site is located in Hood 
Canal and Dabob Bay, in Jefferson, Kitsap, and Mason counties. The Carr 
Inlet OPAREA is located in southern Puget Sound.
    The Keyport Range Site is located adjacent to NAVBASE Kitsap, 
Keyport, providing approximately 3.2 nm\2\ for testing, including in-
shore shallow water sites and a shallow lagoon to support integrated 
undersea warfare systems and vehicle maintenance and engineering 
activities. Water depth at the Keyport Range Site is less than 100 ft. 
(30.5 m). Underwater tracking of test activities can be accomplished by 
using temporary or portable range equipment. The Navy has conducted 
testing at the Keyport Range Site since 1914.
    The DBRC Site includes the Dabob Bay and the Hood Canal from 1 mi. 
(1.6 km) south of the Hood Canal Bridge to the Hamma Hamma River, a 
total area of approximately 45.7 nm\2\. The Navy has conducted 
underwater testing at the DBRC Site since 1956, beginning with a 
control center at Whitney Point. The control center was subsequently 
moved to Zelatched Point.
    Dabob Bay is a deep-water area in Jefferson County approximately 
14.5 nm\2\ in size and contains an acoustic tracking range. The 
acoustic tracking space within the range is approximately 7.3 nm by 1.3 
nm (9 nm\2\) with a maximum depth of 600 ft. (182.9 m). The Dabob Bay 
tracking range, the only component of the DBRC Site with extensive 
acoustic monitoring instrumentation installed on the seafloor, provides 
for object tracking, communications, passive sensing, and target 
simulation. Many activities conducted within Dabob Bay are supported by 
land-based facilities at Zelatched Point.
    Hood Canal averages a depth of 200 ft. (61 m) and is used for 
vessel sensor accuracy tests and launch and recovery of test systems 
where tracking is optional.
    The Carr Inlet OPAREA is a quiet deep-water inland range 
approximately 12 nm\2\ in size. It is located in an arm of water 
between Key Peninsula and Gig Harbor Peninsula. Its southern end is 
connected to the southern basin of Puget Sound. Northward, it separates 
McNeil Island and Fox Island as well as the peninsulas of Key and Gig 
Harbor. The acoustic tracking space within the range is approximately 6 
nm by 2 nm with a maximum depth of 545 ft. (166 m). The Navy performed 
underwater acoustic testing at Carr Inlet from the 1950s through 2009, 
when activities were relocated to NAVBASE Kitsap, Bangor. While no 
permanently installed structures are present in the Carr Inlet OPAREA, 
the waterway remains a Navy-restricted area.
    Pierside Testing Facilities--In addition to the training and 
testing ranges, at which most of the training and testing assessed in 
this document occurs, the Navy conducts some testing at or near Navy 
piers. Most of this testing is sonar maintenance and testing while 
ships are in port for maintenance or system re-fitting. These piers 
within the Study Area are all within Puget Sound and include the 
NAVBASE Kitsap, Bremerton in Sinclair Inlet; NAVBASE Kitsap, Bangor 
Waterfront in Hood Canal, and Naval Station Everett.
    Navy Surface Operations Areas--In addition to the areas mentioned 
above, there are two surface and subsurface operations areas used for 
Navy training and testing within the Inland Waters. Navy 3 OPAREA is a 
surface and subsurface area off the west coast of northern Whidbey 
Island. Navy 7 OPAREA is the surface and subsurface area that lies 
beneath R-6701. This area covers a total area of 61 nm\2\.

Western Behm Canal, Alaska

    The Western Behm Canal is located in Southeast Alaska, near the 
city of Ketchikan, Alaska. SEAFAC is located in the Western Behm Canal 
and covers an area of 48 nm\2\. The Navy has been conducting testing 
activities at SEAFAC since 1992. The facility replaced the Santa Cruz 
Acoustic Range Facility in Southern California and is now the location 
for some acoustic testing previously conducted at the NSWC Carr Inlet 
Acoustic Range in Washington State.
    SEAFAC is comprised of land-based facilities and in-water assets. 
The land-based facilities are located within 5.5 acres (2 hectares) on 
Back Island and are not included in the scope of this analysis. The in-
water assets include two sites: the underway site and the static site. 
These assets and the operational area of SEAFAC are located in five 
restricted areas. The underway site arrays are in Area 1. The static 
site is in Area 2. All associated underwater cabling and other devices 
associated with the underway site are located in Area 3. Area 4 
provides a corridor for utility power and a phone cable. Area 5 is an 
operational area to allow for safe passage of local vessel traffic. 
Notifications of invoking restriction of Area 5 occur at least 72 hours 
prior to SEAFAC operations in accordance with 33 CFR 34.1275. During 
test periods, all vessels entering Area 5 are requested to contact 
SEAFAC to coordinate safe passage through the area. Area 5 defines the 
SEAFAC Study Area boundary, which is comprised only of the in-water 
area and excludes the land-based supporting facilities and operations.
    The SEAFAC at-sea areas are:
     Restricted Areas 1 through 5. The five restricted areas 
are located within Western Behm Canal. The main purposes of the 
restricted areas are to provide for vessel and public safety, lessen 
acoustic encroachment from non-participating vessels, and prohibit 
certain activities that could damage SEAFAC's sensitive in-water 
acoustic instruments and associated cables. Area 5 encompasses the 
entire SEAFAC operations area.
     Underway Measurement Site. The underway measurement site 
is in the center of Western Behm Canal and is 5,000 yards (yd.) (4,572 
m) wide and 12,000 yd. (10,973 m) long. The acoustic arrays are located 
at the center of this area (Area 1).
     Static Site. The static site is approximately 2 nm 
northwest of Back Island. During testing, a vessel is tethered between 
two surface barges. In most scenarios, the vessel submerges to conduct 
acoustic measurements. The static site is located at the center of Area 
2.
     Area 3 and Area 4. These restricted areas provide 
protection to underwater cables and bottom-mounted equipment they 
encompass.
    Bottom-moored acoustic measurement arrays are located in the middle 
of the site. These instrumented arrays are established for measuring 
vessel signatures when a vessel is underway (underway site) and is at 
rest and moored (static site). The instruments are passive arrays of 
hydrophones sensing the acoustic signature of the vessels (i.e., the 
sounds emitted when sonar units are not in operation). Hydrophones on 
the arrays pick up noise in the water and transmit it to shore 
facilities, where the data are processed. SEAFAC's sensitive and well-
positioned acoustic measurement equipment provides the ability to 
listen to and record the

[[Page 31749]]

radiated signature of submarines, as well as other submerged manned and 
unmanned vehicles, selected NOAA surface vessels, and cruise ships.
    The sensors at SEAFAC are passive and measure radiated noise in the 
water, such as machinery on submarines and other underwater vessels. 
Vessels do not use tactical mid-frequency active sonar while undergoing 
testing at SEAFAC. Active acoustic sources are used for communications, 
range calibration, and to provide position information for units 
operating submerged on the range.

Description of Marine Mammals in the Area of the Specified Activities

    Twenty-nine marine mammal species are known to occur in the Study 
Area, including seven mysticetes (baleen whales), 16 odontocetes 
(dolphins and toothed whales), and six pinnipeds (seals and sea lions). 
Among these species, there are 50 stocks managed by NMFS or the U.S. 
Fish and Wildlife Service (USFWS) in the U.S. Exclusive Economic Zone 
(EEZ). These species and their numbers are presented in Table 9. 
Consistent with NMFS most recent Pacific Stock Assessment Report, a 
single species may include multiple stocks recognized for management 
purposes (e.g., killer whale), while other species are grouped into a 
single stock due to limited species-specific information (e.g., beaked 
whales belonging to the genus Mesoplodon).

             Table 9--Marine Mammals With Possible or Confirmed Presence Within the NWTT Study Area
----------------------------------------------------------------------------------------------------------------
         Common name            Scientific name        Stock        Stock abundance            ESA/MMPA
----------------------------------------------------------------------------------------------------------------
North Pacific right whale....  Eubalaena         Eastern North     31..............  Endangered/Depleted.
                                japonica.         Pacific.
Humpback whale...............  Megaptera         Central North     10,103..........  Endangered/Depleted.
                                novaeangliae.     Pacific.
                                                 California,       1,918...........  Endangered/Depleted.
                                                  Oregon, &
                                                  Washington.
Blue whale...................  Balaenoptera      Eastern North     1,647...........  Endangered/Depleted.
                                musculus.         Pacific.
Fin whale....................  Balaenoptera      Northeast         1,214 (minimum    Endangered/Depleted.
                                physalus.         Pacific.          estimate).
                                                 California,       3,051...........  Endangered/Depleted.
                                                  Oregon, &
                                                  Washington.
Sei whale....................  Balaenoptera      Eastern North     126.............  Endangered/Depleted.
                                borealis.         Pacific.
Minke whale..................  Balaenoptera      Alaska..........  Not available...
                                acutorostrata.
                                                 California,       478.............
                                                  Oregon, &
                                                  Washington.
Gray whale...................  Eschrichtius      Eastern North     19,126..........
                                robustus.         Pacific.
                                                 Western North     155.............  Endangered/Depleted.
                                                  Pacific.
Sperm whale..................  Physeter          North Pacific...  Not available...  Endangered/Depleted.
                                macrocephalus.
                                                 California,       971.............  Endangered/Depleted.
                                                  Oregon, &
                                                  Washington.
Pygmy sperm whale............  Kogia breviceps.  California,       579.............
                                                  Oregon, &
                                                  Washington.
Dwarf sperm whale............  Kogia sima......  California,       Not available...
                                                  Oregon, &
                                                  Washington.
Killer whale.................  Orcinus orca....  Alaskan Resident  2,347...........
                                                 Northern          261.............
                                                  Resident.
                                                 West Coast        243.............
                                                  Transient.
                                                 Eastern North     240.............
                                                  Pacific
                                                  Offshore.
                                                 Eastern North     85 (direct        Endangered/Depleted.
                                                  Pacific           count).
                                                  Southern
                                                  Resident.
Short-finned pilot whale.....  Globicephala      California,       760.............
                                macrorhynchus.    Oregon, &
                                                  Washington.
Short-beaked common dolphin..  Delphinus         California,       411,211.........
                                delphis.          Oregon, &
                                                  Washington.
Bottlenose dolphin...........  Tursiops          California,       1,006...........
                                truncatus.        Oregon, &
                                                  Washington
                                                  Offshore.
Striped dolphin..............  Stenella          California,       10,908..........
                                coeruleoalba.     Oregon, &
                                                  Washington.
Pacific white-sided dolphin..  Lagenorhynchus    North Pacific...  26,880..........
                                obliquidens.
                                                 California,       26,930..........
                                                  Oregon, &
                                                  Washington.
Northern right whale dolphin.  Lissodelphis      California,       8,334...........
                                borealis.         Oregon, &
                                                  Washington.
Risso's dolphin..............  Grampus griseus.  California,       6,272...........
                                                  Oregon, &
                                                  Washington.
Harbor porpoise..............  Phocoena          Southeast Alaska  11,146..........
                                phocoena.
                                                 Northern Oregon/  21,487..........
                                                  WA Coast.
                                                 Northern CA/      35,769..........
                                                  southern OR.
                                                 WA Inland Waters  10,682.           ...........................
                                                 Alaska..........  83,400..........
Dall's porpoise..............  Phocoenoides      California,       42,000..........
                                dalli.            Oregon, &
                                                  Washington.
Cuvier's beaked whale........  Ziphius           Alaska..........  Not available...
                                cavirostris.
                                                 California,       6,590...........
                                                  Oregon, &
                                                  Washington.
Baird's beaked whale.........  Berardius         Alaska..........  Not available...
                                bairdii.
                                                 California,       847.............
                                                  Oregon, &
                                                  Washington.

[[Page 31750]]

 
Mesoplodont beaked whales \1\  Mesoplodon spp..  California,       694.............
                                                  Oregon, &
                                                  Washington.
Steller sea lion.............  Eumetopias        Eastern U.S.....  63,160-78,198...
                                jubatus.
California sea lion..........  Zalophus          U.S.............  296,750.........
                                californianus.
Northern fur seal............  Callorhinus       Eastern Pacific.  639,545.........  Depleted.
                                ursinus.
                                                 California        12,844..........
                                                  Breeding.
Guadalupe fur seal...........  Arctocephalus     Mexico..........  14,000-15,000...  Threatened/Depleted.
                                townsendi.
Northern elephant seal.......  Mirounga          California        124,000.........
                                angustirostris.   Breeding.
Harbor seal..................  Phoca vitulina..  Southeast Alaska  152,602.........
                                                  (Clarence
                                                  Strait).
                                                 OR/WA Coast.....  24,732..........
                                                 California......  30,196..........
                                                 WA Northern       11,036..........
                                                  Inland Waters.
                                                 Southern Puget    1,568...........
                                                  Sound.
                                                 Hood Canal......  3,555. \2\
----------------------------------------------------------------------------------------------------------------
\1\ In waters off the U.S. west coast, the Mesoplodon species M. carlhubbsi, M. ginkgodens, M. perrini, M.
  peruvianus, M. stejnegeri and M. densirostris have been grouped by NMFS into a single management unit
  (Mesoplodon spp.) in the 2014 Pacific Stock Assessment report (Carretta et al., 2014).
\2\ The most recent SAR (2014) divided the harbor seals within the Inland Waters into three stocks: The
  Washington Northern Inland Waters stock; the Southern Puget Sound stock, and the Hood Canal stock.

    Based on recent discussion with regional NMFS subject matter 
experts and subsequent to the publication of the 2014 SAR, the Navy and 
NMFS applied research presented in London et al. (2012) to reevaluate 
the Hood Canal stock abundance. Using updated tag data from London et 
al. 2012, the count of harbor seals collected in 1999 (n=711) from 
aerial surveys (Jeffries et al., 2003) was corrected to account for 
harbor seal haulout behavior that most closely aligned with the season 
and time of day in which the original survey was conducted. The tag 
data showed that during this month and time of day, approximately 80 
percent of the animals would be in the water. Therefore, the corrected 
Hood Canal stock abundance (based on the 1999 aerial survey) is 
calculated as 711/0.20 or 711*5 = 3,555. While this aerial survey data 
is considered out of date based on the standards of NOAA stock 
assessment reports, this revised Hood Canal harbor seal abundance 
represents the best available science based on publically available 
data.
    Information on the status, distribution, abundance, and 
vocalizations of marine mammal species in the Study Area may be viewed 
in Chapter 4 of the LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm). Further information on the general 
biology and ecology of marine mammals is included in the NWTT DEIS/
OEIS. In addition, NMFS publishes annual SARs for marine mammals, 
including stocks that occur within the Study Area (http://www.nmfs.noaa.gov/pr/species/mammals; Carretta et al., 2014; Allen and 
Angliss, 2014).

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 microPascal ([micro]Pa) at 1 m. Low-

[[Page 31751]]

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

Brief Background on Sound

    An understanding of the basic properties of underwater sound is 
necessary to comprehend many of the concepts and analyses presented in 
this document. A summary is included below.
    Sound is a wave of pressure variations propagating through a medium 
(e.g., water). Pressure variations are created by compressing and 
relaxing the medium. Sound measurements can be expressed in two forms: 
intensity and pressure. Acoustic intensity is the average rate of 
energy transmitted through a unit area in a specified direction and is 
expressed in watts per square meter (W/m\2\). Acoustic intensity is 
rarely measured directly, but rather from ratios of pressures; the 
standard reference pressure for underwater sound is 1 [micro]Pa; for 
airborne sound, the standard reference pressure is 20 [micro]Pa 
(Richardson et al., 1995).
    Acousticians have adopted a logarithmic scale for sound 
intensities, which is denoted in decibels (dB). Decibel measurements 
represent the ratio between a measured pressure value and a reference 
pressure value (in this case 1 [micro]Pa or, for airborne sound, 20 
[micro]Pa). The logarithmic nature of the scale means that each 10-dB 
increase is a ten-fold increase in acoustic power (and a 20-dB increase 
is then a 100-fold increase in power; and a 30-dB increase is a 1,000-
fold increase in power). A ten-fold increase in acoustic power does not 
mean that the sound is perceived as being ten times louder, however. 
Humans perceive a 10-dB increase in sound level as a doubling of 
loudness, and a 10-dB decrease in sound level as a halving of loudness. 
The term ``sound pressure level'' implies a decibel measure and a 
reference pressure that is used as the denominator of the ratio. 
Throughout this document, NMFS uses 1 [micro]Pa (denoted re: 
1[micro]Pa) as a standard reference pressure unless noted otherwise.
    It is important to note that decibel values underwater and decibel 
values in air are not the same (different reference pressures and 
densities/sound speeds between media) and should not be directly 
compared. Because of the different densities of air and water and the 
different decibel standards (i.e., reference pressures) in air and 
water, a sound with the same level in air and in water would be 
approximately 62 dB lower in air. Thus, a sound that measures 160 dB 
(re 1 [micro]Pa) underwater would have the same approximate effective 
level as a sound that is 98 dB (re 20 [micro]Pa) in air.
    Sound frequency is measured in cycles per second, or Hertz 
(abbreviated Hz), and is analogous to musical pitch; high-pitched 
sounds contain high frequencies and low-pitched sounds contain low 
frequencies. Natural sounds in the ocean span a huge range of 
frequencies: from earthquake noise at 5 Hz to harbor porpoise clicks at 
150,000 Hz (150 kHz). These sounds are so low or so high in pitch that 
humans cannot even hear them; acousticians call these infrasonic 
(typically below 20 Hz) and ultrasonic (typically above 20,000 Hz) 
sounds, respectively. A single sound may be made up of many different 
frequencies together. Sounds made up of only a small range of 
frequencies are called ``narrowband'', and sounds with a broad range of 
frequencies are called ``broadband''; explosives are an example of a 
broadband sound source and active tactical sonars are an example of a 
narrowband sound source.
    When considering the influence of various kinds of sound on the 
marine environment, it is necessary to understand that different kinds 
of marine life are sensitive to different frequencies of sound. Current 
data indicate that not all marine mammal species have equal hearing 
capabilities (Richardson et al., 1995; Southall et al., 1997; Wartzok 
and Ketten, 1999; Au and Hastings, 2008).
    Southall et al. (2007) designated ``functional hearing groups'' for 
marine mammals based on available behavioral data; audiograms derived 
from auditory evoked potentials; anatomical modeling; and other data. 
Southall et al. (2007) also estimated the lower and upper frequencies 
of functional hearing for each group. However, animals are less 
sensitive to sounds at the outer edges of their functional hearing 
range and are more sensitive to a range of frequencies within the 
middle of their functional hearing range. Note that no direct 
measurements of hearing ability have been successfully completed for 
low-frequency cetaceans. The functional groups and the associated 
frequencies are indicated below (note that these frequency ranges 
correspond to the range for the composite group, with the entire range 
not necessarily reflecting the capabilities of every species within 
that group):
     Low frequency cetaceans (13 species of mysticetes): 
Functional hearing estimates occur between approximately 7 Hz and 30 
kilohertz (kHz) (extended from 22 kHz based on data indicating that 
some mysticetes can hear above 22 kHz; Watkins, 1986; Ketten, 1998; 
Houser et al., 2001; Au et al., 2006; Lucifredi and Stein, 2007; Ketten 
et al., 2007; Parks et al., 2007a; Ketten and Mountain, 2009; Tubelli 
et al., 2012);
     Mid-frequency cetaceans (larger toothed whales, beaked 
whales, and most delphinids): Functional hearing is estimated to occur 
between approximately 150 Hz and 160 kHz, with best hearing from 10 to 
less than 100 kHz (Johnson, 1967; White, 1977; Richardson et al., 1995; 
Szymanski et al., 1999; Kastelein et al., 2003; Finneran et al., 2005a, 
2009; Nachtigall et al., 2005, 2008; Yuen et al., 2005;

[[Page 31752]]

Popov et al., 2007; Au and Hastings, 2008; Houser et al., 2008; Pacini 
et al., 2010, 2011; Schlundt et al., 2011);
     High-frequency cetaceans (porpoises, river dolphins, and 
members of the genera Kogia and Cephalorhynchus; including two members 
of the genus Lagenorhynchus, including the hourglass dolphin, on the 
basis of recent echolocation data and genetic data [May-Collado and 
Agnarsson, 2006; Kyhn et al., 2009, 2010; Tougaard et al., 2010]): 
Functional hearing is estimated to occur between approximately 200 Hz 
and 180 kHz (Popov and Supin, 1990a,b; Kastelein et al., 2002; Popov et 
al., 2005); and
     Pinnipeds in water; Phocidae (true seals): Functional 
hearing is estimated to occur between approximately 75 Hz to 100 kHz, 
with best hearing between 1-50 kHz (M[oslash]hl, 1968; Terhune and 
Ronald, 1971, 1972; Richardson et al., 1995; Kastak and Schusterman, 
1999; Reichmuth, 2008; Kastelein et al., 2009);
     Pinnipeds in water; Otariidae (eared seals): Functional 
hearing is estimated to occur between 100 Hz and 40 kHz for Otariidae, 
with best hearing between 2-48 kHz (Schusterman et al., 1972; Moore and 
Schusterman, 1987; Babushina et al., 1991; Richardson et al., 1995; 
Kastak and Schusterman, 1998; Kastelein et al., 2005a; Mulsow and 
Reichmuth, 2007; Mulsow et al., 2011a, b).
    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth et al., 
2013).
    Concurrent with the development of NOAA's Ocean Noise Strategy and 
draft ``Guidance for Assessing the Effects of Anthropogenic Sound on 
Marine Mammals,'' NMFS is currently considering additional 
modifications to some of the functional hearing ranges proposed by 
Southall et al. (2007). As more data from more species and/or 
individuals become available, these estimated hearing ranges may 
require additional modifications.
    When sound travels (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 away. Acousticians often refer to the loudness 
of a sound at its source (typically referenced to one meter from the 
source) as the source level and the loudness of sound elsewhere as the 
received level (i.e., typically the receiver). For example, a humpback 
whale 3 km from a device that has a source level of 230 dB may only be 
exposed to sound that is 160 dB loud, depending on how the sound 
travels through water (e.g., spherical spreading [3 dB reduction with 
doubling of distance] was used in this example). As a result, it is 
important to understand the difference between source levels and 
received levels when discussing the loudness of sound in the ocean or 
its impacts on the marine environment.
    As sound travels from a source, its propagation in water is 
influenced by various physical characteristics, including water 
temperature, depth, salinity, and surface and bottom properties that 
cause refraction, reflection, absorption, and scattering of sound 
waves. Oceans are not homogeneous and the contribution of each of these 
individual factors is extremely complex and interrelated. The physical 
characteristics that determine the sound's speed through the water will 
change with depth, season, geographic location, and with time of day 
(as a result, in actual active sonar operations, crews will measure 
oceanic conditions, such as sea water temperature and depth, to 
calibrate models that determine the path the sonar signal will take as 
it travels through the ocean and how strong the sound signal will be at 
a given range along a particular transmission path). 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.
    Sound pressure level (SPL)--Sound pressure is the sound force per 
unit area, and is usually measured in micropascals ([micro]Pa), where 1 
Pa is the pressure resulting from a force of one newton exerted over an 
area of one square meter. SPL is expressed as the ratio of a measured 
sound pressure and a reference level.

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

    The commonly used reference pressure level in underwater acoustics 
is 1 [micro]Pa, and the units for SPLs are dB re: 1 [micro]Pa. SPL is 
an instantaneous pressure measurement and can be expressed as the peak, 
the peak-peak, or the root mean square (rms). Root mean square 
pressure, which is the square root of the 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 exposure into account. SPL is the applicable metric used in 
the risk continuum, which is used to estimate behavioral harassment 
takes (see Level B Harassment Risk Function (Behavioral Harassment) 
Section).
    Sound exposure level (SEL)--SEL is an energy metric that integrates 
the squared instantaneous sound pressure over a stated time interval. 
The units for SEL are dB re: 1 [micro]Pa\2\-s. Below is a simplified 
formula for SEL.

SEL = SPL + 10 log (duration in seconds)

    As applied to active sonar, 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 
Study Area. The Navy has analyzed potential impacts to marine mammals 
from impulsive and non-impulsive sound sources and vessel strike.
    Other potential impacts to marine mammals from training activities 
in the Study Area were analyzed in the Navy's January 2014 NWTT DEIS/
OEIS, in consultation with NMFS as a cooperating agency, and determined 
to be unlikely to result in marine mammal harassment. Therefore, the 
Navy has not requested authorization for take of marine mammals that 
might occur incidental to other components of their proposed 
activities. In this document, NMFS analyzes the potential effects on 
marine mammals from exposure to non-impulsive sound sources (sonar and 
other active acoustic sources), impulsive sound sources (underwater 
detonations), and vessel strikes.

[[Page 31753]]

    For the purpose of MMPA authorizations, NMFS' effects assessments 
serve four primary purposes: (1) To prescribe the permissible methods 
of taking (i.e., Level B harassment (behavioral harassment), Level A 
harassment (injury), or mortality, including an identification of the 
number and types of take that could occur by harassment or mortality) 
and to prescribe other means of effecting the least practicable adverse 
impact on such species or stock and its habitat (i.e., mitigation); (2) 
to determine whether the specified activity would have a negligible 
impact on the affected species or stocks of marine mammals (based on 
the likelihood that the activity would adversely affect the species or 
stock through effects on annual rates of recruitment or survival); (3) 
to determine whether the specified activity would have an unmitigable 
adverse impact on the availability of the species or stock(s) for 
subsistence uses; and (4) to prescribe requirements pertaining to 
monitoring and reporting.
    More specifically, for activities involving non-impulsive or 
impulsive sources, NMFS' analysis will identify the probability of 
lethal responses, physical trauma, sensory impairment (permanent and 
temporary threshold shifts and acoustic masking), physiological 
responses (particular stress responses), behavioral disturbance (that 
rises to the level of harassment), and social responses (effects to 
social relationships) that would be classified as a take and whether 
such take would have a negligible impact on such species or stocks. 
This section focuses qualitatively on the different ways that non-
impulsive and impulsive sources may affect marine mammals (some of 
which NMFS would not classify as harassment). Then, in the Estimated 
Take of Marine Mammals section, the potential effects to marine mammals 
from non-impulsive and impulsive sources will be related to the MMPA 
definitions of Level A and Level B harassment, along with the potential 
effects from vessel strikes, and we will attempt to quantify those 
effects.

Non-Impulsive Sources

Direct Physiological Effects

    Based on the literature, there are two basic ways that non-
impulsive sources might directly result in physical trauma or damage: 
Noise-induced loss of hearing sensitivity (more commonly-called 
``threshold shift'') and acoustically mediated bubble growth. 
Separately, an animal's behavioral reaction to an acoustic exposure 
could lead to physiological effects that might ultimately lead to 
injury or death, which is discussed later in the Stranding section.
    Threshold Shift (noise-induced loss of hearing)--When animals 
exhibit reduced hearing sensitivity (i.e., sounds must be louder for an 
animal to detect them) following exposure to an intense sound or sound 
for long duration, it is referred to as a noise-induced threshold shift 
(TS). An animal can experience temporary threshold shift (TTS) or 
permanent threshold shift (PTS). TTS can last from minutes or hours to 
days (i.e., there is complete recovery), can occur in specific 
frequency ranges (i.e., an animal might only have a temporary loss of 
hearing sensitivity between the frequencies of 1 and 10 kHz), and can 
be of varying amounts (for example, an animal's hearing sensitivity 
might be reduced initially by only 6 dB or reduced by 30 dB). PTS is 
permanent, but some recovery is possible. PTS can also occur in a 
specific frequency range and amount as mentioned above for TTS.
    The following physiological mechanisms are thought to play a role 
in inducing auditory TS: Effects to sensory hair cells in the inner ear 
that reduce their sensitivity, modification of the chemical environment 
within the sensory cells, residual muscular activity in the middle ear, 
displacement of certain inner ear membranes, increased blood flow, and 
post-stimulatory reduction in both efferent and sensory neural output 
(Southall et al., 2007). The amplitude, duration, frequency, temporal 
pattern, and energy distribution of sound exposure all can affect the 
amount of associated TS and the frequency range in which it occurs. As 
amplitude and duration of sound exposure increase, so, generally, does 
the amount of TS, along with the recovery time. For intermittent 
sounds, less TS could occur than compared to a continuous exposure with 
the same energy (some recovery could occur between intermittent 
exposures depending on the duty cycle between sounds) (Kryter et al., 
1966; Ward, 1997). For example, one short but loud (higher SPL) sound 
exposure may induce the same impairment as one longer but softer sound, 
which in turn may cause more impairment than a series of several 
intermittent softer sounds with the same total energy (Ward, 1997). 
Additionally, though TTS is temporary, prolonged exposure to sounds 
strong enough to elicit TTS, or shorter-term exposure to sound levels 
well above the TTS threshold, can cause PTS, at least in terrestrial 
mammals (Kryter, 1985). Although in the case of mid- and high-frequency 
active sonar (MFAS/HFAS), animals are not expected to be exposed to 
levels high enough or durations long enough to result in PTS.
    PTS is considered auditory injury (Southall et al., 2007). 
Irreparable damage to the inner or outer cochlear hair cells may cause 
PTS; however, other mechanisms are also involved, such as exceeding the 
elastic limits of certain tissues and membranes in the middle and inner 
ears and resultant changes in the chemical composition of the inner ear 
fluids (Southall et al., 2007).
    Although the published body of scientific literature contains 
numerous theoretical studies and discussion papers on hearing 
impairments that can occur with exposure to a loud sound, only a few 
studies provide empirical information on the levels at which noise-
induced loss in hearing sensitivity occurs in nonhuman animals. For 
marine mammals, 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; Kastelein et al., 2012a; Schlundt et 
al., 2000; Nachtigall et al., 2003, 2004). For pinnipeds in water, data 
are limited to measurements of TTS in harbor seals, an elephant seal, 
and California sea lions (Kastak et al., 1999, 2005; Kastelein 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 occurs 
during a time where ambient noise is lower and there are not as many 
competing sounds present. Alternatively, a larger amount and longer 
duration of TTS sustained during time when communication is critical 
for successful mother/calf interactions could have more serious 
impacts. Also, depending on the degree and frequency range, the effects 
of PTS on an animal could range in severity, although it is considered 
generally more serious because it is a permanent

[[Page 31754]]

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 one can infer that strategies exist 
for coping with this condition to some degree, though likely not 
without cost.
    Acoustically Mediated Bubble Growth--One theoretical cause of 
injury to marine mammals is rectified diffusion (Crum and Mao, 1996), 
the process of increasing the size of a bubble by exposing it to a 
sound field. This process could be facilitated if the environment in 
which the ensonified bubbles exist is supersaturated with gas. 
Repetitive diving by marine mammals can cause the blood and some 
tissues to accumulate gas to a greater degree than is supported by the 
surrounding environmental pressure (Ridgway and Howard, 1979). The 
deeper and longer dives of some marine mammals (for example, beaked 
whales) are theoretically predicted to induce greater supersaturation 
(Houser et al., 2001b). If rectified diffusion were possible in marine 
mammals exposed to high-level sound, conditions of tissue 
supersaturation could theoretically speed the rate and increase the 
size of bubble growth. Subsequent effects due to tissue trauma and 
emboli would presumably mirror those observed in humans suffering from 
decompression sickness.
    It is unlikely that the short duration of sonar pings or explosion 
sounds would be long enough to drive bubble growth to any substantial 
size, if such a phenomenon occurs. However, an alternative but related 
hypothesis has also been suggested: Stable bubbles could be 
destabilized by high-level sound exposures such that bubble growth then 
occurs through static diffusion of gas out of the tissues. In such a 
scenario the marine mammal would need to be in a gas-supersaturated 
state for a long enough period of time for bubbles to become of a 
problematic size. Recent research with ex vivo supersaturated bovine 
tissues suggested that, for a 37 kHz signal, a sound exposure of 
approximately 215 dB referenced to (re) 1 [mu]Pa would be required 
before microbubbles became destabilized and grew (Crum et al., 2005). 
Assuming spherical spreading loss and a nominal sonar source level of 
235 dB re 1 [mu]Pa at 1 m, a whale would need to be within 10 m (33 
ft.) of the sonar dome to be exposed to such sound levels. Furthermore, 
tissues in the study were supersaturated by exposing them to pressures 
of 400-700 kilopascals for periods of hours and then releasing them to 
ambient pressures. Assuming the equilibration of gases with the tissues 
occurred when the tissues were exposed to the high pressures, levels of 
supersaturation in the tissues could have been as high as 400-700 
percent. These levels of tissue supersaturation are substantially 
higher than model predictions for marine mammals (Houser et al., 2001; 
Saunders et al., 2008). It is improbable that this mechanism is 
responsible for stranding events or traumas associated with beaked 
whale strandings. Both the degree of supersaturation and exposure 
levels observed to cause microbubble destabilization are unlikely to 
occur, either alone or in concert.
    Yet another hypothesis (decompression sickness) has speculated that 
rapid ascent to the surface following exposure to a startling sound 
might produce tissue gas saturation sufficient for the evolution of 
nitrogen bubbles (Jepson et al., 2003; Fernandez et al., 2005; 
Fern[aacute]ndez et al., 2012). In this scenario, the rate of ascent 
would need to be sufficiently rapid to compromise behavioral or 
physiological protections against nitrogen bubble formation. 
Alternatively, Tyack et al. (2006) studied the deep diving behavior of 
beaked whales and concluded that: ``Using current models of breath-hold 
diving, we infer that their natural diving behavior is inconsistent 
with known problems of acute nitrogen supersaturation and embolism.'' 
Collectively, these hypotheses can be referred to as ``hypotheses of 
acoustically mediated bubble growth.''
    Although theoretical predictions suggest the possibility for 
acoustically mediated bubble growth, there is considerable disagreement 
among scientists as to its likelihood (Piantadosi and Thalmann, 2004; 
Evans and Miller, 2003). Crum and Mao (1996) hypothesized that received 
levels would have to exceed 190 dB in order for there to be the 
possibility of significant bubble growth due to supersaturation of 
gases in the blood (i.e., rectified diffusion). More recent work 
conducted by Crum et al. (2005) demonstrated the possibility of 
rectified diffusion for short duration signals, but at SELs and tissue 
saturation levels that are highly improbable to occur in diving marine 
mammals. To date, energy levels (ELs) predicted to cause in vivo bubble 
formation within diving cetaceans have not been evaluated (NOAA, 
2002b). Although it has been argued that traumas from some recent 
beaked whale strandings are consistent with gas emboli and bubble-
induced tissue separations (Jepson et al., 2003), there is no 
conclusive evidence of this. However, Jepson et al. (2003, 2005) and 
Fernandez et al. (2004, 2005, 2012) concluded that in vivo bubble 
formation, which may be exacerbated by deep, long-duration, repetitive 
dives may explain why beaked whales appear to be particularly 
vulnerable to sonar exposures. Further investigation is needed to 
further assess the potential validity of these hypotheses. More 
information regarding hypotheses that attempt to explain how behavioral 
responses to non-impulsive sources can lead to strandings is included 
in the Stranding and Mortality section.

Acoustic Masking

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

[[Page 31755]]

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

Impaired Communication

    In addition to making it more difficult for animals to perceive 
acoustic cues in their environment, anthropogenic sound presents 
separate challenges for animals that are vocalizing. When they 
vocalize, animals are aware of environmental conditions that affect the 
``active space'' of their vocalizations, which is the maximum area 
within which their vocalizations can be detected before it drops to the 
level of ambient noise (Brenowitz, 2004; Brumm et al., 2004; Lohr et 
al., 2003). Animals are also aware of environmental conditions that 
affect whether listeners can discriminate and recognize their 
vocalizations from other sounds, which is more important than simply 
detecting that a vocalization is occurring (Brenowitz, 1982; Brumm et 
al., 2004; Dooling, 2004, Marten and Marler, 1977; Patricelli et al., 
2006). Most 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 
responses.
    In the case of many stressors, an animal's first and sometimes most 
economical (in terms of biotic costs) response is behavioral avoidance 
of the potential stressor or avoidance of continued exposure to a 
stressor. An animal's second line of defense to stressors involves the 
sympathetic part of the autonomic nervous system and the classical 
``fight or flight'' response which includes the cardiovascular system, 
the gastrointestinal system, the exocrine glands, and the adrenal 
medulla to produce changes in heart rate, blood pressure, and 
gastrointestinal activity that humans commonly associate with 
``stress.'' These responses have a relatively short duration and may or 
may not have significant long-term effect on an animal's welfare.
    An animal's third line of defense to stressors involves its 
neuroendocrine systems; the system that has received the most study has 
been the hypothalmus-pituitary-adrenal system (also known as the HPA 
axis in mammals or the hypothalamus-pituitary-interrenal axis in fish 
and some reptiles). Unlike stress responses associated with the 
autonomic nervous system, virtually all neuro-endocrine functions that 
are affected by stress--including immune competence, reproduction, 
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been 
implicated in failed reproduction (Moberg, 1987; Rivier, 1995), altered 
metabolism (Elasser et al., 2000), reduced immune competence (Blecha, 
2000), and behavioral disturbance. Increases in the circulation of 
glucocorticosteroids (cortisol, corticosterone, and aldosterone in 
marine mammals; see Romano et al., 2004) have been equated with stress 
for many years.
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and distress is the biotic cost 
of the response. During a stress response, an animal uses glycogen 
stores that can be quickly replenished once the stress is alleviated. 
In such circumstances, the cost of the stress response would not pose a 
risk to the animal's welfare. However, when an animal does not have 
sufficient energy reserves to satisfy the energetic costs of a stress 
response, energy resources must be diverted from other biotic 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'' (Seyle, 1950) or ``allostatic 
loading'' (McEwen and Wingfield, 2003). This pathological state will 
last until the animal replenishes its biotic

[[Page 31756]]

reserves sufficient to restore normal function. Note that these 
examples involved a long-term (days or weeks) stress response exposure 
to stimuli.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses have also been documented 
fairly well through controlled experiments; because this physiology 
exists in every vertebrate that has been studied, it is not surprising 
that stress responses and their costs have been documented in both 
laboratory and free-living animals (for examples see, Holberton et al., 
1996; Hood et al., 1998; Jessop et al., 2003; Krausman et al., 2004; 
Lankford et al., 2005; Reneerkens et al., 2002; Thompson and Hamer, 
2000). Information has also been collected on the physiological 
responses of marine mammals to exposure to anthropogenic sounds (Fair 
and Becker, 2000; Romano et al., 2002; Wright et al., 2008). For 
example, Rolland et al. (2012) found that noise reduction from reduced 
ship traffic in the Bay of Fundy was associated with decreased stress 
in North Atlantic right whales. In a conceptual model developed by the 
Population Consequences of Acoustic Disturbance (PCAD) working group, 
serum hormones were identified as possible indicators of behavioral 
effects that are translated into altered rates of reproduction and 
mortality. The Office of Naval Research hosted a workshop (Effects of 
Stress on Marine Mammals Exposed to Sound) in 2009 that focused on this 
very topic (ONR, 2009).
    Studies of other marine animals and terrestrial animals would also 
lead us to expect some marine mammals to experience physiological 
stress responses and, perhaps, physiological responses that would be 
classified as ``distress'' upon exposure to high frequency, mid-
frequency and low-frequency sounds. For example, Jansen (1998) reported 
on the relationship between acoustic exposures and physiological 
responses that are indicative of stress responses in humans (for 
example, elevated respiration and increased heart rates). Jones (1998) 
reported on reductions in human performance when faced with acute, 
repetitive exposures to acoustic disturbance. Trimper et al. (1998) 
reported on the physiological stress responses of osprey to low-level 
aircraft noise while Krausman et al. (2004) reported on the auditory 
and physiology stress responses of endangered Sonoran pronghorn to 
military overflights. Smith et al. (2004a, 2004b), for example, 
identified noise-induced physiological transient stress responses in 
hearing-specialist fish (i.e., goldfish) that accompanied short- and 
long-term hearing losses. Welch and Welch (1970) reported physiological 
and behavioral stress responses that accompanied damage to the inner 
ears of fish and several mammals.
    Hearing is one of the primary senses marine mammals use to gather 
information about their environment and to communicate with 
conspecifics. Although empirical information on the 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 more recent 
review (Nowacek et al., 2007) addresses studies conducted since 1995 
and focuses on observations where the received sound level of the 
exposed marine mammal(s) was known or could be estimated. The following 
sub-sections provide examples of behavioral responses that provide an 
idea of the variability in behavioral responses that would be expected 
given the differential sensitivities of marine mammal species to sound 
and the wide range of potential acoustic sources to which a marine 
mammal may be exposed. Estimates of the types of behavioral responses 
that could occur for a given sound exposure should be determined from 
the literature that is available for each species, or extrapolated from 
closely related species when no information exists.
    Flight Response--A flight response is a dramatic change in normal 
movement to a directed and rapid movement away from the perceived 
location of a sound source. Relatively little information on flight 
responses of marine mammals to anthropogenic signals exist, 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

[[Page 31757]]

the coastal waters off British Columbia are frequently targeted by 
certain groups of killer whales, but not others. The seals discriminate 
between the calls of threatening and non-threatening killer whales 
(Deecke et al., 2002), a capability that should increase survivorship 
while reducing the energy required for attending to and responding to 
all killer whale calls. The occurrence of masking or hearing impairment 
provides a means by which marine mammals may be prevented from 
responding to the acoustic cues produced by their predators. Whether or 
not this is a possibility depends on the duration of the masking/
hearing impairment and the likelihood of encountering a predator during 
the time that predator cues are impeded.
    Diving--Changes in dive behavior can vary widely. They may consist 
of increased or decreased dive times and surface intervals as well as 
changes in the rates of ascent and descent during a dive. Variations in 
dive behavior may reflect interruptions in biologically significant 
activities (e.g., foraging) or they may be of little biological 
significance. Variations in dive behavior may also expose an animal to 
potentially harmful conditions (e.g., increasing the chance of ship-
strike) or may serve as an avoidance response that enhances 
survivorship. The impact of a variation in diving resulting from an 
acoustic exposure depends on what the animal is doing at the time of 
the exposure and the type and magnitude of the response.
    Nowacek et al. (2004) reported disruptions of dive behaviors in 
foraging North Atlantic right whales when exposed to an alerting 
stimulus, an action, they noted, that could lead to an increased 
likelihood of ship strike. However, the whales did not respond to 
playbacks of either right whale social sounds or vessel noise, 
highlighting the importance of the sound characteristics in producing a 
behavioral reaction. Conversely, Indo-Pacific humpback dolphins have 
been observed to dive for longer periods of time in areas where vessels 
were present and/or approaching (Ng and Leung, 2003). In both of these 
studies, the influence of the sound exposure cannot be decoupled from 
the physical presence of a surface vessel, thus complicating 
interpretations of the relative contribution of each stimulus to the 
response. Indeed, the presence of surface vessels, their approach, and 
speed of approach, seemed to be significant factors in the response of 
the Indo-Pacific humpback dolphins (Ng and Leung, 2003). Low frequency 
signals of the Acoustic Thermometry of Ocean Climate (ATOC) sound 
source were not found to affect dive times of humpback whales in 
Hawaiian waters (Frankel and Clark, 2000) or to overtly affect elephant 
seal dives (Costa et al., 2003). They did, however, produce subtle 
effects that varied in direction and degree among the individual seals, 
illustrating the equivocal nature of behavioral effects and consequent 
difficulty in defining and predicting them.
    Due to past incidents of beaked whale strandings associated with 
sonar operations, feedback paths are provided between avoidance and 
diving and indirect tissue effects. This feedback accounts for the 
hypothesis that variations in diving behavior and/or avoidance 
responses can possibly result in nitrogen tissue supersaturation and 
nitrogen off-gassing, possibly to the point of deleterious vascular 
bubble formation (Jepson et al., 2003). Although hypothetical, 
discussions surrounding this potential process are controversial.
    Foraging--Disruption of feeding behavior can be difficult to 
correlate with anthropogenic sound exposure, so it is usually inferred 
by observed displacement from known foraging areas, the appearance of 
secondary indicators (e.g., bubble nets or sediment plumes), or changes 
in dive behavior. Noise from seismic surveys was not found to impact 
the feeding behavior in western grey whales off the coast of Russia 
(Yazvenko et al., 2007) and sperm whales engaged in foraging dives did 
not abandon dives when exposed to distant signatures of seismic airguns 
(Madsen et al., 2006). However, Miller et al. (2009) reported buzz 
rates (a proxy for feeding) 19 percent lower during exposure to distant 
signatures of seismic airguns. Balaenopterid whales exposed to moderate 
low-frequency signals similar to the ATOC sound source demonstrated no 
variation in foraging activity (Croll et al., 2001), whereas five out 
of six North Atlantic right whales exposed to an acoustic alarm 
interrupted their foraging dives (Nowacek et al., 2004). Although the 
received sound pressure levels were similar in the latter two studies, 
the frequency, duration, and temporal pattern of signal presentation 
were different. These factors, as well as differences in species 
sensitivity, are likely contributing factors to the differential 
response. Blue whales exposed to simulated mid-frequency sonar in the 
Southern California Bight were less likely to produce low frequency 
calls usually associated with feeding behavior (Melc[oacute]n et al., 
2012). It is not known whether the lower rates of calling actually 
indicated a reduction in feeding behavior or social contact since the 
study used data from remotely deployed, passive acoustic monitoring 
buoys. In contrast, blue whales increased their likelihood of calling 
when ship noise was present, and decreased their likelihood of calling 
in the presence of explosive noise, although this result was not 
statistically significant (Melc[oacute]n et al., 2012). Additionally, 
the likelihood of an animal calling decreased with the increased 
received level of mid-frequency sonar, beginning at a SPL of 
approximately 110-120 dB re 1 [micro]Pa (Melc[oacute]n et al., 2012). 
Preliminary results from the 2010-2011 field season of an ongoing 
behavioral response study in Southern California waters indicated that, 
in some cases and at low received levels, tagged blue whales responded 
to mid-frequency sonar but that those responses were mild and there was 
a quick return to their baseline activity (Southall et al., 2011). A 
determination of whether foraging disruptions incur fitness 
consequences will require information on or estimates of the energetic 
requirements of the individuals and the relationship between prey 
availability, foraging effort and success, and the life history stage 
of the animal. Goldbogen et al., (2013) monitored behavioral responses 
of tagged blue whales located in feeding areas when exposed simulated 
MFA sonar. Responses varied depending on behavioral context, with deep 
feeding whales being more significantly affected (i.e., generalized 
avoidance; cessation of feeding; increased swimming speeds; or directed 
travel away from the source) compared to surface feeding individuals 
that typically showed no change in behavior. Non-feeding whales also 
seemed to be affected by exposure. The authors indicate that disruption 
of feeding and displacement could impact individual fitness and health.
    Breathing--Variations in respiration naturally vary with different 
behaviors and variations in respiration rate as a function of acoustic 
exposure can be expected to co-occur with other behavioral reactions, 
such as a flight response or an alteration in diving. However, 
respiration rates in and of themselves may be representative of 
annoyance or an acute stress response. Mean exhalation rates of gray 
whales at rest and while diving were found to be unaffected by seismic 
surveys conducted adjacent to the whale feeding grounds (Gailey et al., 
2007). Studies with captive harbor porpoises showed increased 
respiration rates upon introduction of acoustic alarms

[[Page 31758]]

(Kastelein et al., 2001; Kastelein et al., 2006a) and emissions for 
underwater data transmission (Kastelein et al., 2005). However, 
exposure of the same acoustic alarm to a striped dolphin under the same 
conditions did not elicit a response (Kastelein et al., 2006a), again 
highlighting the importance in understanding species differences in the 
tolerance of underwater noise when determining the potential for 
impacts resulting from anthropogenic sound exposure (Southall et al., 
2007; Henderson et al., 2014).
    Social Relationships--Social interactions between mammals can be 
affected by noise via the disruption of communication signals or by the 
displacement of individuals. Disruption of social relationships 
therefore depends on the disruption of other behaviors (e.g., caused 
avoidance, masking, etc.) and no specific overview is provided here. 
However, social disruptions must be considered in context of the 
relationships that are affected. Long-term disruptions of mother/calf 
pairs or mating displays have the potential to affect the growth and 
survival or reproductive effort/success of individuals, respectively.
    Vocalizations (also see Masking Section)--Vocal changes in response 
to anthropogenic noise can occur across the repertoire of sound 
production modes used by marine mammals, such as whistling, 
echolocation click production, calling, and singing. Changes may result 
in response to a need to compete with an increase in background noise 
or may reflect an increased vigilance or startle response. For example, 
in the presence of low-frequency active sonar, humpback whales have 
been observed to increase the length of their ''songs'' (Miller et al., 
2000; Fristrup et al., 2003), possibly due to the overlap in 
frequencies between the whale song and the low-frequency active sonar. 
A similar compensatory effect for the presence of low-frequency vessel 
noise has been suggested for right whales; right whales have been 
observed to shift the frequency content of their calls upward while 
reducing the rate of calling in areas of increased anthropogenic noise 
(Parks et al., 2007). Killer whales off the northwestern coast of the 
U.S. have been observed to increase the duration of primary calls once 
a threshold in observing vessel density (e.g., whale watching) was 
reached, which has been suggested as a response to increased masking 
noise produced by the vessels (Foote et al., 2004; NOAA, 2014b). In 
contrast, both sperm and pilot whales potentially ceased sound 
production during the Heard Island feasibility test (Bowles et al., 
1994), although it cannot be absolutely determined whether the 
inability to acoustically detect the animals was due to the cessation 
of sound production or the displacement of animals from the area.
    Avoidance--Avoidance is the displacement of an individual from an 
area as a result of the presence of a sound. Richardson et al., (1995) 
noted that avoidance reactions are the most obvious manifestations of 
disturbance in marine mammals. It is qualitatively different from the 
flight response, but also differs in the magnitude of the response 
(i.e., directed movement, rate of travel, etc.). Oftentimes avoidance 
is temporary, and animals return to the area once the noise has ceased. 
Longer term displacement is possible, however, which can lead to 
changes in abundance or distribution patterns of the species in the 
affected region if they do not become acclimated to the presence of the 
sound (Blackwell et al., 2004; Bejder et al., 2006; Teilmann et al., 
2006). Acute avoidance responses have been observed in captive 
porpoises and pinnipeds exposed to a number of different sound sources 
(Kastelein et al., 2001; Finneran et al., 2003; Kastelein et al., 
2006a; Kastelein et al., 2006b). Short-term avoidance of seismic 
surveys, low frequency emissions, and acoustic deterrents have also 
been noted in wild populations of odontocetes (Bowles et al., 1994; 
Goold, 1996; 1998; Stone et al., 2000; Morton and Symonds, 2002) and to 
some extent in mysticetes (Gailey et al., 2007), while longer term or 
repetitive/chronic displacement for some dolphin groups and for 
manatees has been suggested to be due to the presence of chronic vessel 
noise (Haviland-Howell et al., 2007; Miksis-Olds et al., 2007).
    Maybaum (1993) conducted sound playback experiments to assess the 
effects of MFAS on humpback whales in Hawaiian waters. Specifically, 
she exposed focal pods to sounds of a 3.3-kHz sonar pulse, a sonar 
frequency sweep from 3.1 to 3.6 kHz, and a control (blank) tape while 
monitoring behavior, movement, and underwater vocalizations. The two 
types of sonar signals (which both contained mid- and low-frequency 
components) differed in their effects on the humpback whales, but both 
resulted in avoidance behavior. The whales responded to the pulse by 
increasing their distance from the sound source and responded to the 
frequency sweep by increasing their swimming speeds and track 
linearity. In the Caribbean, sperm whales avoided exposure to mid-
frequency submarine sonar pulses, in the range of 1000 Hz to 10,000 Hz 
(IWC 2005).
    Kvadsheim et al., (2007) conducted a controlled exposure experiment 
in which killer whales fitted with D-tags were exposed to mid-frequency 
active sonar (Source A: a 1.0 second upsweep 209 dB @ 1-2 kHz every 10 
seconds for 10 minutes; Source B: with a 1.0 second upsweep 197 dB @ 6-
7 kHz every 10 seconds for 10 minutes). When exposed to Source A, a 
tagged whale and the group it was traveling with did not appear to 
avoid the source. When exposed to Source B, the tagged whales along 
with other whales that had been carousel feeding, ceased feeding during 
the approach of the sonar and moved rapidly away from the source. When 
exposed to Source B, Kvadsheim and his co-workers reported that a 
tagged killer whale seemed to try to avoid further exposure to the 
sound field by the following behaviors: Immediately swimming away 
(horizontally) from the source of the sound; engaging in a series of 
erratic and frequently deep dives that seemed to take it below the 
sound field; or swimming away while engaged in a series of erratic and 
frequently deep dives. Although the sample sizes in this study are too 
small to support statistical analysis, the behavioral responses of the 
orcas were consistent with the results of other studies.
    In 2007, the first in a series of behavioral response studies, a 
collaboration by the Navy, NMFS, and other scientists showed one beaked 
whale (Mesoplodon densirostris) responding to an MFAS playback. Tyack 
et al. (2011) indicates that the playback began when the tagged beaked 
whale was vocalizing at depth (at the deepest part of a typical feeding 
dive), following a previous control with no sound exposure. The whale 
appeared to stop clicking significantly earlier than usual, when 
exposed to mid-frequency signals in the 130-140 dB (rms) received level 
range. After a few more minutes of the playback, when the received 
level reached a maximum of 140-150 dB, the whale ascended on the slow 
side of normal ascent rates with a longer than normal ascent, at which 
point the exposure was terminated. The results are from a single 
experiment and a greater sample size is needed before robust and 
definitive conclusions can be drawn.
    Tyack et al. (2011) also indicates that Blainville's beaked whales 
appear to be sensitive to noise at levels well below expected TTS (~160 
dB re1[micro]Pa). This sensitivity is manifest by an adaptive movement 
away from a sound source. This response was observed irrespective of 
whether the signal transmitted was within the band width of MFAS, which 
suggests that beaked whales may not

[[Page 31759]]

respond to the specific sound signatures. Instead, they may be 
sensitive to any pulsed sound from a point source in this frequency 
range. The response to such stimuli appears to involve maximizing the 
distance from the sound source.
    Stimpert et al. (2014) tagged a Baird's beaked whale, which was 
subsequently exposed to simulated mid-frequency sonar. Changes in the 
animal's dive behavior and locomotion were observed when received level 
reached 127 dB re1[mu]Pa.
    Results from a 2007-2008 study conducted near the Bahamas showed a 
change in diving behavior of an adult Blainville's beaked whale to 
playback of mid-frequency source and predator sounds (Boyd et al., 
2008; Southall et al. 2009; Tyack et al., 2011). Reaction to mid-
frequency sounds included premature cessation of clicking and 
termination of a foraging dive, and a slower ascent rate to the 
surface. Results from a similar behavioral response study in southern 
California waters have been presented for the 2010-2011 field season 
(Southall et al. 2011; DeRuiter et al., 2013b). DeRuiter et al. (2013b) 
presented results from two Cuvier's beaked whales that were tagged and 
exposed to simulated mid-frequency active sonar during the 2010 and 
2011 field seasons of the southern California behavioral response 
study. The 2011 whale was also incidentally exposed to mid-frequency 
active sonar from a distant naval exercise. Received levels from the 
mid-frequency active sonar signals from the controlled and incidental 
exposures were calculated as 84-144 and 78-106 dB re 1 [micro]Pa root 
mean square (rms), respectively. Both whales showed responses to the 
controlled exposures, ranging from initial orientation changes to 
avoidance responses characterized by energetic fluking and swimming 
away from the source. However, the authors did not detect similar 
responses to incidental exposure to distant naval sonar exercises at 
comparable received levels, indicating that context of the exposures 
(e.g., source proximity, controlled source ramp-up) may have been a 
significant factor. Cuvier's beaked whale responses suggested 
particular sensitivity to sound exposure as consistent with results for 
Blainville's beaked whale. Similarly, beaked whales exposed to sonar 
during British training exercises stopped foraging (DSTL, 2007), and 
preliminary results of controlled playback of sonar may indicate 
feeding/foraging disruption of killer whales and sperm whales (Miller 
et al., 2011).
    In the 2007-2008 Bahamas study, playback sounds of a potential 
predator--a killer whale--resulted in a similar but more pronounced 
reaction, which included longer inter-dive intervals and a sustained 
straight-line departure of more than 20 km from the area. The authors 
noted, however, that the magnified reaction to the predator sounds 
could represent a cumulative effect of exposure to the two sound types 
since killer whale playback began approximately 2 hours after mid-
frequency source playback. Pilot whales and killer whales off Norway 
also exhibited horizontal avoidance of a transducer with outputs in the 
mid-frequency range (signals in the 1-2 kHz and 6-7 kHz ranges) (Miller 
et al., 2011). Additionally, separation of a calf from its group during 
exposure to mid-frequency sonar playback was observed on one occasion 
(Miller et al., 2011). In contrast, preliminary analyses suggest that 
none of the pilot whales or false killer whales in the Bahamas showed 
an avoidance response to controlled exposure playbacks (Southall et 
al., 2009).
    Through analysis of the behavioral response studies, a preliminary 
overarching effect of greater sensitivity to all anthropogenic 
exposures was seen in beaked whales compared to the other odontocetes 
studied (Southall et al., 2009). Therefore, recent studies have focused 
specifically on beaked whale responses to active sonar transmissions or 
controlled exposure playback of simulated sonar on various military 
ranges (Defence Science and Technology Laboratory, 2007; Claridge and 
Durban, 2009; Moretti et al., 2009; McCarthy et al., 2011; Tyack et 
al., 2011). In the Bahamas, Blainville's beaked whales located on the 
range will move off-range during sonar use and return only after the 
sonar transmissions have stopped, sometimes taking several days to do 
so (Claridge and Durban 2009; Moretti et al., 2009; McCarthy et al., 
2011; Tyack et al., 2011). Moretti et al. (2014) used recordings from 
seafloor-mounted hydrophones at the Atlantic Undersea Test and 
Evaluation Center (AUTEC) to analyze the probability of Blainsville's 
beaked whale dives before, during, and after Navy sonar exercises.
    Orientation--A shift in an animal's resting state or an attentional 
change via an orienting response represent behaviors that would be 
considered mild disruptions if occurring alone. As previously 
mentioned, the responses may co-occur with other behaviors; for 
instance, an animal may initially orient toward a sound source, and 
then move away from it. Thus, any orienting response should be 
considered in context of other reactions that may occur.
    There are few empirical studies of avoidance responses of free-
living cetaceans to MFAS. Much more information is available on the 
avoidance responses of free-living cetaceans to other acoustic sources, 
such as seismic airguns and low-frequency tactical sonar, than MFAS.

Behavioral Responses

    Southall et al. (2007) reports the results of the efforts of a 
panel of experts in acoustic research from behavioral, physiological, 
and physical disciplines that convened and reviewed the available 
literature on marine mammal hearing and physiological and behavioral 
responses to human-made sound with the goal of proposing exposure 
criteria for certain effects. This peer-reviewed compilation of 
literature is very valuable, though Southall et al. (2007) note that 
not all data are equal, some have poor statistical power, insufficient 
controls, and/or limited information on received levels, background 
noise, and other potentially important contextual variables--such data 
were reviewed and sometimes used for qualitative illustration but were 
not included in the quantitative analysis for the criteria 
recommendations. All of the studies considered, however, contain an 
estimate of the received sound level when the animal exhibited the 
indicated response.
    In the Southall et al. (2007) publication, for the purposes of 
analyzing responses of marine mammals to anthropogenic sound and 
developing criteria, the authors differentiate between single pulse 
sounds, multiple pulse sounds, and non-pulse sounds. MFAS/HFAS sonar is 
considered a non-pulse sound. Southall et al. (2007) summarize the 
studies associated with low-frequency, mid-frequency, and high-
frequency cetacean and pinniped responses to non-pulse sounds, based 
strictly on received level, in Appendix C of their article 
(incorporated by reference and summarized in the three paragraphs 
below).
    The studies that address responses of low-frequency cetaceans to 
non-pulse sounds include data gathered in the field and related to 
several types of sound sources (of varying similarity to MFAS/HFAS) 
including: Vessel noise, drilling and machinery playback, low-frequency 
M-sequences (sine wave with multiple phase reversals) playback, 
tactical low-frequency active sonar playback, drill ships, Acoustic 
Thermometry of Ocean Climate (ATOC) source, and non-pulse playbacks. 
These studies generally indicate no (or very

[[Page 31760]]

limited) responses to received levels in the 90 to 120 dB re: 1 [mu]Pa 
range and an increasing likelihood of avoidance and other behavioral 
effects in the 120 to 160 dB range. As mentioned earlier, though, 
contextual variables play a very important role in the reported 
responses and the severity of effects are not linear when compared to 
received level. Also, few of the laboratory or field datasets had 
common conditions, behavioral contexts or sound sources, so it is not 
surprising that responses differ.
    The studies that address responses of mid-frequency cetaceans to 
non-pulse sounds include data gathered both in the field and the 
laboratory and related to several different sound sources (of varying 
similarity to MFAS/HFAS) including: Pingers, drilling playbacks, ship 
and ice-breaking noise, vessel noise, Acoustic Harassment Devices 
(AHDs), Acoustic Deterrent Devices (ADDs), MFAS, and non-pulse bands 
and tones. Southall et al. (2007) were unable to come to a clear 
conclusion regarding the results of these studies. In some cases, 
animals in the field showed significant responses to received levels 
between 90 and 120 dB, while in other cases these responses were not 
seen in the 120 to 150 dB range. The disparity in results was likely 
due to contextual variation and the differences between the results in 
the field and laboratory data (animals typically responded at lower 
levels in the field).
    The studies that address responses of high frequency cetaceans to 
non-pulse sounds include data gathered both in the field and the 
laboratory and related to several different sound sources (of varying 
similarity to MFAS/HFAS) including: pingers, AHDs, and various 
laboratory non-pulse sounds. All of these data were collected from 
harbor porpoises. Southall et al. (2007) concluded that the existing 
data indicate that harbor porpoises are likely sensitive to a wide 
range of anthropogenic sounds at low received levels (~ 90 to 120 dB), 
at least for initial exposures. All recorded exposures above 140 dB 
induced profound and sustained avoidance behavior in wild harbor 
porpoises (Southall et al., 2007). Rapid habituation was noted in some 
but not all studies. There is no data to indicate whether other high 
frequency cetaceans are as sensitive to anthropogenic sound as harbor 
porpoises are.
    The studies that address the responses of pinnipeds in water to 
non-pulse sounds include data gathered both in the field and the 
laboratory and related to several different sound sources (of varying 
similarity to MFAS/HFAS) including: AHDs, ATOC, various non-pulse 
sounds used in underwater data communication; underwater drilling, and 
construction noise. Few studies exist with enough information to 
include them in the analysis. The limited data suggested that exposures 
to non-pulse sounds between 90 and 140 dB generally do not result in 
strong behavioral responses in pinnipeds in water, but no data exist at 
higher received levels.

Potential Effects of Behavioral Disturbance

    The different ways that marine mammals respond to sound are 
sometimes indicators of the ultimate effect that exposure to a given 
stimulus will have on the well-being (survival, reproduction, etc.) of 
an animal. There is limited marine mammal data quantitatively relating 
the exposure of marine mammals to sound to effects on reproduction or 
survival, though data exists for terrestrial species to which we can 
draw comparisons for marine mammals.
    Attention is the cognitive process of selectively concentrating on 
one aspect of an animal's environment while ignoring other things 
(Posner, 1994). Because animals (including humans) have limited 
cognitive resources, there is a limit to how much sensory information 
they can process at any time. The phenomenon called ``attentional 
capture'' occurs when a stimulus (usually a stimulus that an animal is 
not concentrating on or attending to) ``captures'' an animal's 
attention. This shift in attention can occur consciously or 
subconsciously (for example, when an animal hears sounds that it 
associates with the approach of a predator) and the shift in attention 
can be sudden (Dukas, 2002; van Rij, 2007). Once a stimulus has 
captured an animal's attention, the animal can respond by ignoring the 
stimulus, assuming a ``watch and wait'' posture, or treat the stimulus 
as a disturbance and respond accordingly, which includes scanning for 
the source of the stimulus or ``vigilance'' (Cowlishaw et al., 2004).
    Vigilance is normally an adaptive behavior that helps animals 
determine the presence or absence of predators, assess their distance 
from conspecifics, or to attend cues from prey (Bednekoff and Lima, 
1998; Treves, 2000). Despite those benefits, however, vigilance has a 
cost of time; when animals focus their attention on specific 
environmental cues, they are not attending to other activities such as 
foraging. These costs have been documented best in foraging animals, 
where vigilance has been shown to substantially reduce feeding rates 
(Saino, 1994; Beauchamp and Livoreil, 1997; Fritz et al., 2002). 
Animals will spend more time being vigilant, which may translate to 
less time foraging or resting, when disturbance stimuli approach them 
more directly, remain at closer distances, have a greater group size 
(for example, multiple surface vessels), or when they co-occur with 
times that an animal perceives increased risk (for example, when they 
are giving birth or accompanied by a calf). Most of the published 
literature, however, suggests that direct approaches will increase the 
amount of time animals will dedicate to being vigilant. For example, 
bighorn sheep and Dall's sheep dedicated more time being vigilant, and 
less time resting or foraging, when aircraft made direct approaches 
over them (Frid, 2001; Stockwell et al., 1991).
    Several authors have established that long-term and intense 
disturbance stimuli can cause population declines by reducing the body 
condition of individuals that have been disturbed, followed by reduced 
reproductive success, reduced survival, or both (Daan et al., 1996; 
Madsen, 1994; White, 1983). For example, Madsen (1994) reported that 
pink-footed geese in undisturbed habitat gained body mass and had about 
a 46-percent reproductive success rate compared with geese in disturbed 
habitat (being consistently scared off the fields on which they were 
foraging) which did not gain mass and had a 17-percent reproductive 
success rate. Similar reductions in reproductive success have been 
reported for mule deer disturbed by all-terrain vehicles (Yarmoloy et 
al., 1988), caribou disturbed by seismic exploration blasts (Bradshaw 
et al., 1998), caribou disturbed by low-elevation military jet-fights 
(Luick et al., 1996), and caribou disturbed by low-elevation jet 
flights (Harrington and Veitch, 1992). Similarly, a study of elk that 
were disturbed experimentally by pedestrians concluded that the ratio 
of young to mothers was inversely related to disturbance rate (Phillips 
and Alldredge, 2000).
    The primary mechanism by which increased vigilance and disturbance 
appear to affect the fitness of individual animals is by disrupting an 
animal's time budget and, as a result, reducing the time they might 
spend foraging and resting (which increases an animal's activity rate 
and energy demand). For example, a study of grizzly bears reported that 
bears disturbed by hikers reduced their energy intake by an average of 
12 kcal/minute (50.2 x 10\3\kJ/minute), and spent energy fleeing or 
acting aggressively toward hikers (White

[[Page 31761]]

et al., 1999). Alternately, Ridgway et al. (2006) reported that 
increased vigilance in bottlenose dolphins exposed to sound over a 5-
day period did not cause any sleep deprivation or stress effects such 
as changes in cortisol or epinephrine levels.
    Lusseau and Bejder (2007) present data from three long-term studies 
illustrating the connections between disturbance from whale-watching 
boats and population-level effects in cetaceans. In Sharks Bay 
Australia, the abundance of bottlenose dolphins was compared within 
adjacent control and tourism sites over three consecutive 4.5-year 
periods of increasing tourism levels. Between the second and third time 
periods, in which tourism doubled, dolphin abundance decreased by 15 
percent in the tourism area and did not change significantly in the 
control area. In Fiordland, New Zealand, two populations (Milford and 
Doubtful Sounds) of bottlenose dolphins with tourism levels that 
differed by a factor of seven were observed and significant increases 
in travelling time and decreases in resting time were documented for 
both. Consistent short-term avoidance strategies were observed in 
response to tour boats until a threshold of disturbance was reached 
(average 68 minutes between interactions), after which the response 
switched to a longer term habitat displacement strategy. For one 
population tourism only occurred in a part of the home range, however, 
tourism occurred throughout the home range of the Doubtful Sound 
population and once boat traffic increased beyond the 68-minute 
threshold (resulting in abandonment of their home range/preferred 
habitat), reproductive success drastically decreased (increased 
stillbirths) and abundance decreased significantly (from 67 to 56 
individuals in short period). Last, in a study of northern resident 
killer whales off Vancouver Island, exposure to boat traffic was shown 
to reduce foraging opportunities and increase traveling time. A simple 
bioenergetics model was applied to show that the reduced foraging 
opportunities equated to a decreased energy intake of 18 percent, while 
the increased traveling incurred an increased energy output of 3-4 
percent, which suggests that a management action based on avoiding 
interference with foraging might be particularly effective.
    On a related note, many animals perform vital functions, such as 
feeding, resting, traveling, and socializing, on a diel cycle (24-hour 
cycle). Substantive behavioral reactions to noise exposure (such as 
disruption of critical life functions, displacement, or avoidance of 
important habitat) are more likely to be significant if they last more 
than one diel cycle or recur on subsequent days (Southall et al., 
2007). Consequently, a behavioral response lasting less than 1 day and 
not recurring on subsequent days is not considered particularly severe 
unless it could directly affect reproduction or survival (Southall et 
al., 2007). Note that there is a difference between multiple-day 
substantive behavioral reactions and multiple-day anthropogenic 
activities. For example, just because an at-sea exercise lasts for 
multiple days does not necessarily mean that individual animals are 
either exposed to that exercise for multiple days or, further, exposed 
in a manner resulting in a sustained multiple day substantive 
behavioral responses.
    In order to understand how the effects of activities may or may not 
impact stocks and populations of marine mammals, it is necessary to 
understand not only what the likely disturbances are going to be, but 
how those disturbances may affect the reproductive success and 
survivorship of individuals, and then how those impacts to individuals 
translate to population changes. Following on the earlier work of a 
committee of the U.S. National Research Council (NRC, 2005), New et al. 
(2014), in an effort termed the Potential Consequences of Disturbance 
(PCoD), outline an updated conceptual model of the relationships 
linking disturbance to changes in behavior and physiology, health, 
vital rates, and population dynamics (below). As depicted, behavioral 
and physiological changes can either have direct (acute) effects on 
vital rates, such as when changes in habitat use or increased stress 
levels raise the probability of mother-calf separation or predation, or 
they can have indirect and long-term (chronic) effects on vital rates, 
such as when changes in time/energy budgets or increased disease 
susceptibility affect health, which then affects vital rates (New et 
al., 2014).
    In addition to outlining this general framework and compiling the 
relevant literature that supports it, New et al. (2014) have chosen 
four example species for which extensive long-term monitoring data 
exist (southern elephant seals, North Atlantic right whales, Ziphidae 
beaked whales, and bottlenose dolphins) and developed state-space 
energetic models that can be used to effectively forecast longer-term, 
population-level impacts from behavioral changes. While these are very 
specific models with very specific data requirements that cannot yet be 
applied broadly to project-specific risk assessments, they are a 
critical first step.

Stranding and Mortality

    When a live or dead marine mammal swims or floats onto shore and 
becomes ``beached'' or incapable of returning to sea, the event is 
termed a ``stranding'' (Geraci et al., 1999; Perrin and Geraci, 2002; 
Geraci and Lounsbury, 2005; NMFS, 2007). The legal definition for a 
stranding within the U.S. is that (A) ``a marine mammal is dead and is 
(i) on a beach or shore of the United States; or (ii) in waters under 
the jurisdiction of the United States (including any navigable waters); 
or (B) a marine mammal is alive and is (i) on a beach or shore of the 
United States and unable to return to the water; (ii) on a beach or 
shore of the United States and, although able to return to the water, 
is in need of apparent medical attention; or (iii) in the waters under 
the jurisdiction of the United States (including any navigable waters), 
but is unable to return to its natural habitat under its own power or 
without assistance.'' (16 U.S.C. 1421h).
    Marine mammals are known to strand for a variety of reasons, such 
as infectious agents, biotoxicosis, starvation, fishery interaction, 
ship strike, unusual oceanographic or weather events, sound exposure, 
or combinations of these stressors sustained concurrently or in series. 
However, the cause or causes of most strandings are unknown (Geraci et 
al., 1976; Eaton, 1979, Odell et al., 1980; Best, 1982). Numerous 
studies suggest that the physiology, behavior, habitat relationships, 
age, or condition of cetaceans may cause them to strand or might pre-
dispose them to strand when exposed to another phenomenon. These 
suggestions are consistent with the conclusions of numerous other 
studies that have demonstrated that combinations of dissimilar 
stressors commonly combine to kill an animal or dramatically reduce its 
fitness, even though one exposure without the other does not produce 
the same result (Chroussos, 2000; Creel, 2005; DeVries et al., 2003; 
Fair and Becker, 2000; Foley et al., 2001; Moberg, 2000; Relyea, 2005a; 
2005b, Romero, 2004; Sih et al., 2004). For reference, between 2001 and 
2009, there was an annual average of 1,400 cetacean strandings and 
4,300 pinniped strandings along the coasts of the continental U.S. and 
Alaska (NMFS, 2011).
    Several sources have published lists of mass stranding events of 
cetaceans in an attempt to identify relationships between those 
stranding events and military sonar (Hildebrand, 2004; IWC, 2005; 
Taylor et al., 2004). For example,

[[Page 31762]]

based on a review of stranding records between 1960 and 1995, the 
International Whaling Commission (2005) identified ten mass stranding 
events of Cuvier's beaked whales had been reported and one mass 
stranding of four Baird's beaked whale. The IWC concluded that, out of 
eight stranding events reported from the mid-1980s to the summer of 
2003, seven had been coincident with the use of tactical mid-frequency 
sonar, one of those seven had been associated with the use of tactical 
low-frequency sonar, and the remaining stranding event had been 
associated with the use of seismic airguns.
    Most of the stranding events reviewed by the International Whaling 
Commission involved beaked whales. A mass stranding of Cuvier's beaked 
whales in the eastern Mediterranean Sea occurred in 1996 (Frantzis, 
1998) and mass stranding events involving Gervais' beaked whales, 
Blainville's beaked whales, and Cuvier's beaked whales occurred off the 
coast of the Canary Islands in the late 1980s (Simmonds and Lopez-
Jurado, 1991). The stranding events that occurred in the Canary Islands 
and Kyparissiakos Gulf in the late 1990s and the Bahamas in 2000 have 
been the most intensively-studied mass stranding events and have been 
associated with naval maneuvers involving the use of tactical sonar.
    Between 1960 and 2006, 48 strandings (68 percent) involved beaked 
whales, three (4 percent) involved dolphins, and 14 (20 percent) 
involved whale species. Cuvier's beaked whales were involved in the 
greatest number of these events (48 or 68 percent), followed by sperm 
whales (seven or 10 percent), and Blainville's and Gervais' beaked 
whales (four each or 6 percent). Naval activities (not just activities 
conducted by the U.S. Navy) that might have involved active sonar are 
reported to have coincided with nine or 10 (13 to 14 percent) of those 
stranding events. Between the mid-1980s and 2003 (the period reported 
by the International Whaling Commission), NMFS identified reports of 44 
mass cetacean stranding events of which at least seven were coincident 
with naval exercises that were using MFAS.

Strandings Associated With Impulse Sound

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

Strandings Associated With MFAS

    Over the past 16 years, there have been five stranding events 
coincident with military mid-frequency sonar use in which exposure to 
sonar is believed to have been a contributing factor: Greece (1996); 
the Bahamas (2000); Madeira (2000); Canary Islands (2002); and Spain 
(2006). Additionally, in 2004, during the Rim of the Pacific (RIMPAC) 
exercises, between 150 and 200 usually pelagic melon-headed whales 
occupied the shallow waters of Hanalei Bay, Kauai, Hawaii for over 28 
hours. NMFS determined that MFAS was a plausible, if not likely, 
contributing factor in what may have been a confluence of events that 
led to the stranding. A number of other stranding events coincident 
with the operation of mid-frequency sonar, including the death of 
beaked whales or other species (minke whales, dwarf sperm whales, pilot 
whales), have been reported; however, the majority have not been 
investigated to the degree necessary to determine the cause of the 
stranding and only one of these stranding events, the Bahamas (2000), 
was associated with exercises conducted by the U.S. Navy. Most 
recently, the Independent Scientific Review Panel investigating 
potential contributing factors to a 2008 mass stranding of melon-headed 
whales in Antsohihy, Madagascar released its final report suggesting 
that the stranding was likely initially triggered by an industry 
seismic survey. This report suggests that the operation of a commercial 
high-powered 12 kHz multi-beam echosounder during an industry seismic 
survey was a plausible and likely initial trigger that caused a large 
group of melon-headed whales to leave their typical habitat and then 
ultimately strand as a result of secondary factors such as 
malnourishment and dehydration. The report indicates that the risk of 
this particular convergence of factors and ultimate outcome is likely 
very low, but recommends that the potential be considered in 
environmental planning. Because of the association between tactical 
mid-frequency active sonar use and a small number of marine mammal 
strandings, the Navy and NMFS have been considering and addressing the 
potential for strandings in association with Navy activities for years. 
In addition to a suite of mitigation intended to more broadly minimize 
impacts to marine mammals, the Navy and NMFS have a detailed Stranding 
Response Plan that outlines reporting, communication, and response 
protocols intended both to minimize the impacts of, and enhance the 
analysis of, any potential stranding in areas where the Navy operates.
    Greece (1996)--Twelve Cuvier's beaked whales stranded atypically 
(in both time and space) along a 38.2-km strand of the Kyparissiakos 
Gulf coast on May 12 and 13, 1996 (Frantzis, 1998). From May 11 through 
May 15, the North Atlantic Treaty Organization (NATO) research vessel 
Alliance was conducting sonar tests with signals of 600 Hz and 3 kHz 
and source levels of 228 and 226 dB re: 1[mu]Pa, respectively (D'Amico 
and Verboom, 1998; D'Spain et al., 2006). The timing and location of 
the testing encompassed the time and location of the strandings 
(Frantzis, 1998).
    Necropsies of eight of the animals were performed but were limited 
to basic external examination and sampling of stomach contents, blood, 
and skin. No ears or organs were

[[Page 31763]]

collected, and no histological samples were preserved. No apparent 
abnormalities or wounds were found. Examination of photos of the 
animals, taken soon after their death, revealed that the eyes of at 
least four of the individuals were bleeding. Photos were taken soon 
after their death (Frantzis, 2004). Stomach contents contained the 
flesh of cephalopods, indicating that feeding had recently taken place 
(Frantzis, 1998).
    All available information regarding the conditions associated with 
this stranding event were compiled, and many potential causes were 
examined including major pollution events, prominent tectonic activity, 
unusual physical or meteorological events, magnetic anomalies, 
epizootics, and conventional military activities (International Council 
for the Exploration of the Sea, 2005a). However, none of these 
potential causes coincided in time or space with the mass stranding, or 
could explain its characteristics (International Council for the 
Exploration of the Sea, 2005a). The robust condition of the animals, 
plus the recent stomach contents, is inconsistent with pathogenic 
causes. In addition, environmental causes can be ruled out as there 
were no unusual environmental circumstances or events before or during 
this time period and within the general proximity (Frantzis, 2004).
    Because of the rarity of this mass stranding of Cuvier's beaked 
whales in the Kyparissiakos Gulf (first one in history), the 
probability for the two events (the military exercises and the 
strandings) to coincide in time and location, while being independent 
of each other, was thought to be extremely low (Frantzis, 1998). 
However, because full necropsies had not been conducted, and no 
abnormalities were noted, the cause of the strandings could not be 
precisely determined (Cox et al., 2006). A Bioacoustics Panel convened 
by NATO concluded that the evidence available did not allow them to 
accept or reject sonar exposures as a causal agent in these stranding 
events. The analysis of this stranding event provided support for, but 
no clear evidence for, the cause-and-effect relationship of tactical 
sonar training activities and beaked whale strandings (Cox et al., 
2006).
    Bahamas (2000)--NMFS and the Navy prepared a joint report 
addressing the multi-species stranding in the Bahamas in 2000, which 
took place within 24 hours of U.S. Navy ships using MFAS as they passed 
through the Northeast and Northwest Providence Channels on March 15-16, 
2000. The ships, which operated both AN/SQS-53C and AN/SQS-56, moved 
through the channel while emitting sonar pings approximately every 24 
seconds. Of the 17 cetaceans that stranded over a 36-hr period 
(Cuvier's beaked whales, Blainville's beaked whales, minke whales, and 
a spotted dolphin), seven animals died on the beach (five Cuvier's 
beaked whales, one Blainville's beaked whale, and the spotted dolphin), 
while the other 10 were returned to the water alive (though their 
ultimate fate is unknown). As discussed in the Bahamas report (DOC/DON, 
2001), there is no likely association between the minke whale and 
spotted dolphin strandings and the operation of MFAS.
    Necropsies were performed on five of the stranded beaked whales. 
All five necropsied beaked whales were in good body condition, showing 
no signs of infection, disease, ship strike, blunt trauma, or fishery 
related injuries, and three still had food remains in their stomachs. 
Auditory structural damage was discovered in four of the whales, 
specifically bloody effusions or hemorrhaging around the ears. 
Bilateral intracochlear and unilateral temporal region subarachnoid 
hemorrhage, with blood clots in the lateral ventricles, were found in 
two of the whales. Three of the whales had small hemorrhages in their 
acoustic fats (located along the jaw and in the melon).
    A comprehensive investigation was conducted and all possible causes 
of the stranding event were considered, whether they seemed likely at 
the outset or not. Based on the way in which the strandings coincided 
with ongoing naval activity involving tactical MFAS use, in terms of 
both time and geography, the nature of the physiological effects 
experienced by the dead animals, and the absence of any other acoustic 
sources, the investigation team concluded that MFAS aboard U.S. Navy 
ships that were in use during the active sonar exercise in question 
were the most plausible source of this acoustic or impulse trauma to 
beaked whales. This sound source was active in a complex environment 
that included the presence of a surface duct, unusual and steep 
bathymetry, a constricted channel with limited egress, intensive use of 
multiple, active sonar units over an extended period of time, and the 
presence of beaked whales that appear to be sensitive to the 
frequencies produced by these active sonars. The investigation team 
concluded that the cause of this stranding event was the confluence of 
the Navy MFAS and these contributory factors working together, and 
further recommended that the Navy avoid operating MFAS in situations 
where these five factors would be likely to occur. This report does not 
conclude that all five of these factors must be present for a stranding 
to occur, nor that beaked whales are the only species that could 
potentially be affected by the confluence of the other factors. Based 
on this, NMFS believes that the operation of MFAS in situations where 
surface ducts exist, or in marine environments defined by steep 
bathymetry and/or constricted channels may increase the likelihood of 
producing a sound field with the potential to cause cetaceans 
(especially beaked whales) to strand, and therefore, suggests the need 
for increased vigilance while operating MFAS in these areas, especially 
when beaked whales (or potentially other deep divers) are likely 
present.
    Madeira, Spain (2000)--From May 10-14, 2000, three Cuvier's beaked 
whales were found atypically stranded on two islands in the Madeira 
archipelago, Portugal (Cox et al., 2006). A fourth animal was reported 
floating in the Madeiran waters by fisherman but did not come ashore 
(Woods Hole Oceanographic Institution, 2005). Joint NATO amphibious 
training peacekeeping exercises involving participants from 17 
countries 80 warships, took place in Portugal during May 2-15, 2000.
    The bodies of the three stranded whales were examined post mortem 
(Woods Hole Oceanographic Institution, 2005), though only one of the 
stranded whales was fresh enough (24 hours after stranding) to be 
necropsied (Cox et al., 2006). Results from the necropsy revealed 
evidence of hemorrhage and congestion in the right lung and both 
kidneys (Cox et al., 2006). There was also evidence of intercochlear 
and intracranial hemorrhage similar to that which was observed in the 
whales that stranded in the Bahamas event (Cox et al., 2006). There 
were no signs of blunt trauma, and no major fractures (Woods Hole 
Oceanographic Institution, 2005). The cranial sinuses and airways were 
found to be clear with little or no fluid deposition, which may 
indicate good preservation of tissues (Woods Hole Oceanographic 
Institution, 2005).
    Several observations on the Madeira stranded beaked whales, such as 
the pattern of injury to the auditory system, are the same as those 
observed in the Bahamas strandings. Blood in and around the eyes, 
kidney lesions, pleural hemorrhages, and congestion in the lungs are 
particularly consistent with the pathologies from the whales stranded 
in the Bahamas, and are consistent with stress and pressure related 
trauma. The similarities in pathology and stranding patterns between 
these two events suggest that a

[[Page 31764]]

similar pressure event may have precipitated or contributed to the 
strandings at both sites (Woods Hole Oceanographic Institution, 2005).
    Even though no definitive causal link can be made between the 
stranding event and naval exercises, certain conditions may have 
existed in the exercise area that, in their aggregate, may have 
contributed to the marine mammal strandings (Freitas, 2004): exercises 
were conducted in areas of at least 547 fathoms (1,000 m) depth near a 
shoreline where there is a rapid change in bathymetry on the order of 
547 to 3,281 fathoms (1,000 to 6,000 m) occurring across a relatively 
short horizontal distance (Freitas, 2004); multiple ships were 
operating around Madeira, though it is not known if MFAS was used, and 
the specifics of the sound sources used are unknown (Cox et al., 2006, 
Freitas, 2004); and exercises took place in an area surrounded by 
landmasses separated by less than 35 nm (65 km) and at least 10 nm (19 
km) in length, or in an embayment. Exercises involving multiple ships 
employing MFAS near land may produce sound directed towards a channel 
or embayment that may cut off the lines of egress for marine mammals 
(Freitas, 2004).
    Canary Islands, Spain (2002)--The southeastern area within the 
Canary Islands is well known for aggregations of beaked whales due to 
its ocean depths of greater than 547 fathoms (1,000 m) within a few 
hundred meters of the coastline (Fernandez et al., 2005). On September 
24, 2002, 14 beaked whales were found stranded on Fuerteventura and 
Lanzarote Islands in the Canary Islands (International Council for 
Exploration of the Sea, 2005a). Seven whales died, while the remaining 
seven live whales were returned to deeper waters (Fernandez et al., 
2005). Four beaked whales were found stranded dead over the next three 
days either on the coast or floating offshore. These strandings 
occurred within near proximity of an international naval exercise that 
utilized MFAS and involved numerous surface warships and several 
submarines. Strandings began about 4 hours after the onset of MFAS 
activity (International Council for Exploration of the Sea, 2005a; 
Fernandez et al., 2005).
    Eight Cuvier's beaked whales, one Blainville's beaked whale, and 
one Gervais' beaked whale were necropsied, six of them within 12 hours 
of stranding (Fernandez et al., 2005). No pathogenic bacteria were 
isolated from the carcasses (Jepson et al., 2003). The animals 
displayed severe vascular congestion and hemorrhage especially around 
the tissues in the jaw, ears, brain, and kidneys, displaying marked 
disseminated microvascular hemorrhages associated with widespread fat 
emboli (Jepson et al., 2003; International Council for Exploration of 
the Sea, 2005a). Several organs contained intravascular bubbles, 
although definitive evidence of gas embolism in vivo is difficult to 
determine after death (Jepson et al., 2003). The livers of the 
necropsied animals were the most consistently affected organ, which 
contained macroscopic gas-filled cavities and had variable degrees of 
fibrotic encapsulation. In some animals, cavitary lesions had 
extensively replaced the normal tissue (Jepson et al., 2003). Stomachs 
contained a large amount of fresh and undigested contents, suggesting a 
rapid onset of disease and death (Fernandez et al., 2005). Head and 
neck lymph nodes were enlarged and congested, and parasites were found 
in the kidneys of all animals (Fernandez et al., 2005).
    The association of NATO MFAS use close in space and time to the 
beaked whale strandings, and the similarity between this stranding 
event and previous beaked whale mass strandings coincident with sonar 
use, suggests that a similar scenario and causative mechanism of 
stranding may be shared between the events. Beaked whales stranded in 
this event demonstrated brain and auditory system injuries, 
hemorrhages, and congestion in multiple organs, similar to the 
pathological findings of the Bahamas and Madeira stranding events. In 
addition, the necropsy results of Canary Islands stranding event lead 
to the hypothesis that the presence of disseminated and widespread gas 
bubbles and fat emboli were indicative of nitrogen bubble formation, 
similar to what might be expected in decompression sickness (Jepson et 
al., 2003; Fern[aacute]ndez et al., 2005; Fern[aacute]ndez et al., 
2012).
    Hanalei Bay (2004)--On July 3 and 4, 2004, approximately 150 to 200 
melon-headed whales occupied the shallow waters of the Hanalei Bay, 
Kaua'i, Hawaii for over 28 hrs. Attendees of a canoe blessing observed 
the animals entering the Bay in a single wave formation at 7 a.m. on 
July 3, 2004. The animals were observed moving back into the shore from 
the mouth of the Bay at 9 a.m. The usually pelagic animals milled in 
the shallow bay and were returned to deeper water with human assistance 
beginning at 9:30 a.m. on July 4, 2004, and were out of sight by 10:30 
a.m.
    Only one animal, a calf, was known to have died following this 
event. The animal was noted alive and alone in the Bay on the afternoon 
of July 4, 2004, and was found dead in the Bay the morning of July 5, 
2004. A full necropsy, magnetic resonance imaging, and computerized 
tomography examination were performed on the calf to determine the 
manner and cause of death. The combination of imaging, necropsy and 
histological analyses found no evidence of infectious, internal 
traumatic, congenital, or toxic factors. Cause of death could not be 
definitively determined, but it is likely that maternal separation, 
poor nutritional condition, and dehydration contributed to the final 
demise of the animal. Although it is not known when the calf was 
separated from its mother, the animals' movement into the Bay and 
subsequent milling and re-grouping may have contributed to the 
separation or lack of nursing, especially if the maternal bond was weak 
or this was an inexperienced mother with her first calf.
    Environmental factors, abiotic and biotic, were analyzed for any 
anomalous occurrences that would have contributed to the animals 
entering and remaining in Hanalei Bay. The Bay's bathymetry is similar 
to many other sites within the Hawaiian Island chain and dissimilar to 
sites that have been associated with mass strandings in other parts of 
the U.S. The weather conditions appeared to be normal for that time of 
year with no fronts or other significant features noted. There was no 
evidence of unusual distribution, occurrence of predator or prey 
species, or unusual harmful algal blooms, although Mobley et al., 2007 
suggested that the full moon cycle that occurred at that time may have 
influenced a run of squid into the Bay. Weather patterns and bathymetry 
that have been associated with mass strandings elsewhere were not found 
to occur in this instance.
    The Hanalei event was spatially and temporally correlated with 
RIMPAC. Official sonar training and tracking exercises in the Pacific 
Missile Range Facility (PMRF) warning area did not commence until 
approximately 8 a.m. on July 3 and were thus ruled out as a possible 
trigger for the initial movement into the Bay. However, six naval 
surface vessels transiting to the operational area on July 2 
intermittently transmitted active sonar (for approximately 9 hours 
total from 1:15 p.m. to 12:30 a.m.) as they approached from the south. 
The potential for these transmissions to have triggered the whales' 
movement into Hanalei Bay was investigated. Analyses with the 
information available indicated that animals to the south and east of

[[Page 31765]]

Kaua'i could have detected active sonar transmissions on July 2, and 
reached Hanalei Bay on or before 7 a.m. on July 3. However, data 
limitations regarding the position of the whales prior to their arrival 
in the Bay, the magnitude of sonar exposure, behavioral responses of 
melon-headed whales to acoustic stimuli, and other possible relevant 
factors preclude a conclusive finding regarding the role of sonar in 
triggering this event. Propagation modeling suggests that transmissions 
from sonar use during the July 3 exercise in the PMRF warning area may 
have been detectable at the mouth of the Bay. If the animals responded 
negatively to these signals, it may have contributed to their continued 
presence in the Bay. The U.S. Navy ceased all active sonar 
transmissions during exercises in this range on the afternoon of July 
3. Subsequent to the cessation of sonar use, the animals were herded 
out of the Bay.
    While causation of this stranding event may never be unequivocally 
determined, NMFS consider the active sonar transmissions of July 2-3, 
2004, a plausible, if not likely, contributing factor in what may have 
been a confluence of events. This conclusion is based on the following: 
(1) The evidently anomalous nature of the stranding; (2) its close 
spatiotemporal correlation with wide-scale, sustained use of sonar 
systems previously associated with stranding of deep-diving marine 
mammals; (3) the directed movement of two groups of transmitting 
vessels toward the southeast and southwest coast of Kauai; (4) the 
results of acoustic propagation modeling and an analysis of possible 
animal transit times to the Bay; and (5) the absence of any other 
compelling causative explanation. The initiation and persistence of 
this event may have resulted from an interaction of biological and 
physical factors. The biological factors may have included the presence 
of an apparently uncommon, deep-diving cetacean species (and possibly 
an offshore, non-resident group), social interactions among the animals 
before or after they entered the Bay, and/or unknown predator or prey 
conditions. The physical factors may have included the presence of 
nearby deep water, multiple vessels transiting in a directed manner 
while transmitting active sonar over a sustained period, the presence 
of surface sound ducting conditions, and/or intermittent and random 
human interactions while the animals were in the Bay.
    A separate event involving melon-headed whales and rough-toothed 
dolphins took place over the same period of time in the Northern 
Mariana Islands (Jefferson et al., 2006), which is several thousand 
miles from Hawaii. Some 500 to 700 melon-headed whales came into 
Sasanhaya Bay on July 4, 2004, near the island of Rota and then left of 
their own accord after 5.5 hours; no known active sonar transmissions 
occurred in the vicinity of that event. The Rota incident led to 
scientific debate regarding what, if any, relationship the event had to 
the simultaneous events in Hawaii and whether they might be related by 
some common factor (e.g., there was a full moon on July 2, 2004, as 
well as during other melon-headed whale strandings and nearshore 
aggregations (Brownell et al., 2009; Lignon et al., 2007; Mobley et 
al., 2007). Brownell et al. (2009) compared the two incidents, along 
with one other stranding incident at Nuka Hiva in French Polynesia and 
normal resting behaviors observed at Palmyra Island, in regard to 
physical features in the areas, melon-headed whale behavior, and lunar 
cycles. Brownell et al., (2009) concluded that the rapid entry of the 
whales into Hanalei Bay, their movement into very shallow water far 
from the 100-m contour, their milling behavior (typical pre-stranding 
behavior), and their reluctance to leave the bay constituted an unusual 
event that was not similar to the events that occurred at Rota (but was 
similar to the events at Palmyra), which appear to be similar to 
observations of melon-headed whales resting normally at Palmyra Island. 
Additionally, there was no correlation between lunar cycle and the 
types of behaviors observed in the Brownell et al. (2009) examples. 
Since that time there have been two ``out of habitat'' or ``near mass 
strandings'' of melon-headed whales in the Philippines (Aragones et 
al., 2010). Pictures of one of these events depict grouping behavior 
like that displayed at Hanalei Bay in July 2004. No naval sonar 
activity was noted it the area, although it was suspected by the 
authors, based on personal communication with a government fisheries 
representative, that dynamite blasting in the area may have occurred 
within the days prior to one of the events (Aragones et al., 2010). 
Although melon-headed whales entering embayments may be infrequent and 
rare, there is precedent for this type of occurrence on other occasions 
in the absence of naval activity.
    Spain (2006)--The Spanish Cetacean Society reported an atypical 
mass stranding of four beaked whales that occurred January 26, 2006, on 
the southeast coast of Spain, near Mojacar (Gulf of Vera) in the 
Western Mediterranean Sea. According to the report, two of the whales 
were discovered the evening of January 26 and were found to be still 
alive (these later died). Two other whales were discovered during the 
day on January 27, but had already died. The first three animals were 
located near the town of Mojacar and the fourth animal was found dead, 
a few kilometers north of the first three animals. From January 25-26, 
2006, Standing NATO Response Force Maritime Group Two (five of seven 
ships including one U.S. ship under NATO Operational Control) had 
conducted active sonar training against a Spanish submarine within 50 
nm (93 km) of the stranding site.
    Veterinary pathologists necropsied the two male and two female 
Cuvier's beaked whales. According to the pathologists, the most likely 
primary cause of this type of beaked whale mass stranding event was 
anthropogenic acoustic activities, most probably anti-submarine MFAS 
used during the military naval exercises. However, no positive acoustic 
link was established as a direct cause of the stranding. Even though no 
causal link can be made between the stranding event and naval 
exercises, certain conditions may have existed in the exercise area 
that, in their aggregate, may have contributed to the marine mammal 
strandings (Freitas, 2004): exercises were conducted in areas of at 
least 547 fathoms (1,000 m) depth near a shoreline where there is a 
rapid change in bathymetry on the order of 547 to 3,281 fathoms (1,000 
to 6,000 m) occurring across a relatively short horizontal distance 
(Freitas, 2004); multiple ships (in this instance, five) were operating 
MFAS in the same area over extended periods of time (in this case, 20 
hours) in close proximity; and exercises took place in an area 
surrounded by landmasses, or in an embayment. Exercises involving 
multiple ships employing MFAS near land may have produced sound 
directed towards a channel or embayment that may have cut off the lines 
of egress for the affected marine mammals (Freitas, 2004).

Association Between Mass Stranding Events and Exposure to MFAS

    Several authors have noted similarities between some of these 
stranding incidents: They occurred in islands or archipelagoes with 
deep water nearby, several appeared to have been associated with 
acoustic waveguides like surface ducting, and the sound fields created 
by ships transmitting MFAS (Cox et al., 2006, D'Spain et al., 2006). 
Although Cuvier's beaked whales have been the most

[[Page 31766]]

common species involved in these stranding events (81 percent of the 
total number of stranded animals), other beaked whales (including 
Mesoplodon europeaus, M. densirostris, and Hyperoodon ampullatus) 
comprise 14 percent of the total. Other species (Stenella coeruleoalba, 
Kogia breviceps and Balaenoptera acutorostrata) have stranded, but in 
much lower numbers and less consistently than beaked whales.
    Based on the evidence available, however, NMFS cannot determine 
whether (a) Cuvier's beaked whale is more prone to injury from high-
intensity sound than other species; (b) their behavioral responses to 
sound makes them more likely to strand; or (c) they are more likely to 
be exposed to MFAS than other cetaceans (for reasons that remain 
unknown). Because the association between active sonar exposures and 
marine mammals mass stranding events is not consistent--some marine 
mammals strand without being exposed to sonar and some sonar 
transmissions are not associated with marine mammal stranding events 
despite their co-occurrence--other risk factors or a grouping of risk 
factors probably contribute to these stranding events.

Behaviorally Mediated Responses to MFAS That May Lead to Stranding

    Although the confluence of Navy MFAS with the other contributory 
factors noted in the report was identified as the cause of the 2000 
Bahamas stranding event, the specific mechanisms that led to that 
stranding (or the others) are not understood, and there is uncertainty 
regarding the ordering of effects that led to the stranding. It is 
unclear whether beaked whales were directly injured by sound (e.g., 
acoustically mediated bubble growth, as addressed above) prior to 
stranding or whether a behavioral response to sound occurred that 
ultimately caused the beaked whales to be injured and strand.
    Although causal relationships between beaked whale stranding events 
and active sonar remain unknown, several authors have hypothesized that 
stranding events involving these species in the Bahamas and Canary 
Islands may have been triggered when the whales changed their dive 
behavior in a startled response to exposure to active sonar or to 
further avoid exposure (Cox et al., 2006, Rommel et al., 2006). These 
authors proposed three mechanisms by which the behavioral responses of 
beaked whales upon being exposed to active sonar might result in a 
stranding event. These include the following: Gas bubble formation 
caused by excessively fast surfacing; remaining at the surface too long 
when tissues are supersaturated with nitrogen; or diving prematurely 
when extended time at the surface is necessary to eliminate excess 
nitrogen. More specifically, beaked whales that occur in deep waters 
that are in close proximity to shallow waters (for example, the 
``canyon areas'' that are cited in the Bahamas stranding event; see 
D'Spain and D'Amico, 2006), may respond to active sonar by swimming 
into shallow waters to avoid further exposures and strand if they were 
not able to swim back to deeper waters. Second, beaked whales exposed 
to active sonar might alter their dive behavior. Changes in their dive 
behavior might cause them to remain at the surface or at depth for 
extended periods of time which could lead to hypoxia directly by 
increasing their oxygen demands or indirectly by increasing their 
energy expenditures (to remain at depth) and increase their oxygen 
demands as a result. If beaked whales are at depth when they detect a 
ping from an active sonar transmission and change their dive profile, 
this could lead to the formation of significant gas bubbles, which 
could damage multiple organs or interfere with normal physiological 
function (Cox et al., 2006; Rommel et al., 2006; Zimmer and Tyack, 
2007). Baird et al. (2005) found that slow ascent rates from deep dives 
and long periods of time spent within 50 m of the surface were typical 
for both Cuvier's and Blainville's beaked whales, the two species 
involved in mass strandings related to naval sonar. These two 
behavioral mechanisms may be necessary to purge excessive dissolved 
nitrogen concentrated in their tissues during their frequent long dives 
(Baird et al., 2005). Baird et al. (2005) further suggests that 
abnormally rapid ascents or premature dives in response to high-
intensity sonar could indirectly result in physical harm to the beaked 
whales, through the mechanisms described above (gas bubble formation or 
non-elimination of excess nitrogen).
    Because many species of marine mammals make repetitive and 
prolonged dives to great depths, it has long been assumed that marine 
mammals have evolved physiological mechanisms to protect against the 
effects of rapid and repeated decompressions. Although several 
investigators have identified physiological adaptations that may 
protect marine mammals against nitrogen gas supersaturation (alveolar 
collapse and elective circulation; Kooyman et al., 1972; Ridgway and 
Howard, 1979), Ridgway and Howard (1979) reported that bottlenose 
dolphins that were trained to dive repeatedly had muscle tissues that 
were substantially supersaturated with nitrogen gas. Houser et al. 
(2001) used these data to model the accumulation of nitrogen gas within 
the muscle tissue of other marine mammal species and concluded that 
cetaceans that dive deep and have slow ascent or descent speeds would 
have tissues that are more supersaturated with nitrogen gas than other 
marine mammals. Based on these data, Cox et al. (2006) hypothesized 
that a critical dive sequence might make beaked whales more prone to 
stranding in response to acoustic exposures. The sequence began with 
(1) very deep (to depths as deep as 2 kilometers) and long (as long as 
90 minutes) foraging dives; (2) relatively slow, controlled ascents; 
and (3) a series of ``bounce'' dives between 100 and 400 m in depth 
(also see Zimmer and Tyack, 2007). They concluded that acoustic 
exposures that disrupted any part of this dive sequence (for example, 
causing beaked whales to spend more time at surface without the bounce 
dives that are necessary to recover from the deep dive) could produce 
excessive levels of nitrogen supersaturation in their tissues, leading 
to gas bubble and emboli formation that produces pathologies similar to 
decompression sickness.
    Zimmer and Tyack (2007) modeled nitrogen tension and bubble growth 
in several tissue compartments for several hypothetical dive profiles 
and concluded that repetitive shallow dives (defined as a dive where 
depth does not exceed the depth of alveolar collapse, approximately 72 
m for Ziphius), perhaps as a consequence of an extended avoidance 
reaction to sonar sound, could pose a risk for decompression sickness 
and that this risk should increase with the duration of the response. 
Their models also suggested that unrealistically rapid ascent rates of 
ascent from normal dive behaviors are unlikely to result in 
supersaturation to the extent that bubble formation would be expected. 
Tyack et al. (2006) suggested that emboli observed in animals exposed 
to mid-frequency range sonar (Jepson et al., 2003; Fernandez et al., 
2005; Fern[aacute]ndez et al., 2012) could stem from a behavioral 
response that involves repeated dives shallower than the depth of lung 
collapse. Given that nitrogen gas accumulation is a passive process 
(i.e. nitrogen is metabolically inert), a bottlenose dolphin was 
trained to repetitively dive a profile predicted to elevate nitrogen 
saturation to the point

[[Page 31767]]

that nitrogen bubble formation was predicted to occur. However, 
inspection of the vascular system of the dolphin via ultrasound did not 
demonstrate the formation of asymptomatic nitrogen gas bubbles (Houser 
et al., 2007). Baird et al. (2008), in a beaked whale tagging study off 
Hawaii, showed that deep dives are equally common during day or night, 
but ``bounce dives'' are typically a daytime behavior, possibly 
associated with visual predator avoidance. This may indicate that 
``bounce dives'' are associated with something other than behavioral 
regulation of dissolved nitrogen levels, which would be necessary day 
and night.
    If marine mammals respond to a Navy vessel that is transmitting 
active sonar in the same way that they might respond to a predator, 
their probability of flight responses should increase when they 
perceive that Navy vessels are approaching them directly, because a 
direct approach may convey detection and intent to capture (Burger and 
Gochfeld, 1981, 1990; Cooper, 1997, 1998). The probability of flight 
responses should also increase as received levels of active sonar 
increase (and the ship is, therefore, closer) and as ship speeds 
increase (that is, as approach speeds increase). For example, the 
probability of flight responses in Dall's sheep (Ovis dalli dalli) 
(Frid 2001a, b), ringed seals (Phoca hispida) (Born et al., 1999), 
Pacific brant (Branta bernic nigricans) and Canada geese (B. 
Canadensis) increased as a helicopter or fixed-wing aircraft approached 
groups of these animals more directly (Ward et al., 1999). Bald eagles 
(Haliaeetus leucocephalus) perched on trees alongside a river were also 
more likely to flee from a paddle raft when their perches were closer 
to the river or were closer to the ground (Steidl and Anthony, 1996).
    Despite the many theories involving bubble formation (both as a 
direct cause of injury (see Acoustically Mediated Bubble Growth 
Section) and an indirect cause of stranding (See Behaviorally Mediated 
Bubble Growth Section), Southall et al., (2007) summarizes that there 
is either scientific disagreement or a lack of information regarding 
each of the following important points: (1) Received acoustical 
exposure conditions for animals involved in stranding events; (2) 
pathological interpretation of observed lesions in stranded marine 
mammals; (3) acoustic exposure conditions required to induce such 
physical trauma directly; (4) whether noise exposure may cause 
behavioral reactions (such as atypical diving behavior) that 
secondarily cause bubble formation and tissue damage; and (5) the 
extent the post mortem artifacts introduced by decomposition before 
sampling, handling, freezing, or necropsy procedures affect 
interpretation of observed lesions.

Impulsive Sources

    Underwater explosive detonations send a shock wave and sound energy 
through the water and can release gaseous by-products, create an 
oscillating bubble, or cause a plume of water to shoot up from the 
water surface. The shock wave and accompanying noise are of most 
concern to marine animals. Depending on the intensity of the shock wave 
and size, location, and depth of the animal, an animal can be injured, 
killed, suffer non-lethal physical effects, experience hearing related 
effects with or without behavioral responses, or exhibit temporary 
behavioral responses or tolerance from hearing the blast sound. 
Generally, exposures to higher levels of impulse and pressure levels 
would result in greater impacts to an individual animal.
    Injuries resulting from a shock wave take place at boundaries 
between tissues of different densities. Different velocities are 
imparted to tissues of different densities, and this can lead to their 
physical disruption. Blast effects are greatest at the gas-liquid 
interface (Landsberg, 2000). Gas-containing organs, particularly the 
lungs and gastrointestinal tract, are especially susceptible (Goertner, 
1982; Hill, 1978; Yelverton et al., 1973). In addition, gas-containing 
organs including the nasal sacs, larynx, pharynx, trachea, and lungs 
may be damaged by compression/expansion caused by the oscillations of 
the blast gas bubble (Reidenberg and Laitman, 2003). Intestinal walls 
can bruise or rupture, with subsequent hemorrhage and escape of gut 
contents into the body cavity. Less severe gastrointestinal tract 
injuries include contusions, petechiae (small red or purple spots 
caused by bleeding in the skin), and slight hemorrhaging (Yelverton et 
al., 1973).
    Because the ears are the most sensitive to pressure, they are the 
organs most susceptible to injury (Ketten, 2000). Sound-related damage 
associated with sound energy from detonations can be theoretically 
distinct from injury from the shock wave, particularly farther from the 
explosion. If a noise is audible to an animal, it has the potential to 
damage the animal's hearing by causing decreased sensitivity (Ketten, 
1995). Sound-related trauma can be lethal or sublethal. Lethal impacts 
are those that result in immediate death or serious debilitation in or 
near an intense source and are not, technically, pure acoustic trauma 
(Ketten, 1995). Sublethal impacts include hearing loss, which is caused 
by exposures to perceptible sounds. Severe damage (from the shock wave) 
to the ears includes tympanic membrane rupture, fracture of the 
ossicles, damage to the cochlea, hemorrhage, and cerebrospinal fluid 
leakage into the middle ear. Moderate injury implies partial hearing 
loss due to tympanic membrane rupture and blood in the middle ear. 
Permanent hearing loss also can occur when the hair cells are damaged 
by one very loud event, as well as by prolonged exposure to a loud 
noise or chronic exposure to noise. The level of impact from blasts 
depends on both an animal's location and, at outer zones, on its 
sensitivity to the residual noise (Ketten, 1995).
    There have been fewer studies addressing the behavioral effects of 
explosives on marine mammals compared to MFAS/HFAS. However, though the 
nature of the sound waves emitted from an explosion are different (in 
shape and rise time) from MFAS/HFAS, NMFS still anticipates the same 
sorts of behavioral responses to result from repeated explosive 
detonations (a smaller range of likely less severe responses (i.e., not 
rising to the level of MMPA harassment)) would be expected to occur as 
a result of exposure to a single explosive detonation that was not 
powerful enough or close enough to the animal to cause TTS or injury.
    Baleen whales have shown a variety of responses to impulse sound 
sources, including avoidance, reduced surface intervals, altered 
swimming behavior, and changes in vocalization rates (Richardson et 
al., 1995; Gordon et al., 2003; Southall, 2007). While most bowhead 
whales did not show active avoidance until within 8 km of seismic 
vessels (Richardson et al., 1995), some whales avoided vessels by more 
than 20 km at received levels as low as 120 dB re 1 [mu]Pa rms. 
Additionally, Malme et al. (1988) observed clear changes in diving and 
respiration patterns in bowheads at ranges up to 73 km from seismic 
vessels, with received levels as low as 125 dB re 1 [mu]Pa.
    Gray whales migrating along the U.S. west coast showed avoidance 
responses to seismic vessels by 10 percent of animals at 164 dB re 1 
[mu]Pa, and by 90 percent of animals at 190 dB re 1 [mu]Pa, with 
similar results for whales in the Bering Sea (Malme 1986, 1988). In 
contrast, noise from seismic surveys was not found to impact feeding 
behavior or exhalation rates while resting or diving in western gray 
whales off the coast of Russia (Yazvenko et al., 2007; Gailey et al., 
2007).

[[Page 31768]]

    Humpback whales showed avoidance behavior at ranges of 5-8 km from 
a seismic array during observational studies and controlled exposure 
experiments in western Australia (McCauley, 1998; Todd et al., 1996) 
found no clear short-term behavioral responses by foraging humpbacks to 
explosions associated with construction operations in Newfoundland, but 
did see a trend of increased rates of net entanglement and a shift to a 
higher incidence of net entanglement closer to the noise source.
    Seismic pulses at average received levels of 131 dB re 1 
micropascal squared second ([mu]Pa\2\-s) caused blue whales to increase 
call production (Di Iorio and Clark, 2010). In contrast, McDonald et 
al. (1995) tracked a blue whale with seafloor seismometers and reported 
that it stopped vocalizing and changed its travel direction at a range 
of 10 km from the seismic vessel (estimated received level 143 dB re 1 
[mu]Pa peak-to-peak). These studies demonstrate that even low levels of 
noise received far from the noise source can induce behavioral 
responses.
    Madsen et al. (2006) and Miller et al. (2009) tagged and monitored 
eight sperm whales in the Gulf of Mexico exposed to seismic airgun 
surveys. Sound sources were from approximately 2 to 7 nm away from the 
whales and based on multipath propagation received levels were as high 
as 162 dB SPL re 1 [mu]Pa with energy content greatest between 0.3 and 
3.0 kHz (Madsen, 2006). The whales showed no horizontal avoidance, 
although the whale that was approached most closely had an extended 
resting period and did not resume foraging until the airguns had ceased 
firing (Miller et al., 2009). The remaining whales continued to execute 
foraging dives throughout exposure; however, swimming movements during 
foraging dives were 6 percent lower during exposure than control 
periods, suggesting subtle effects of noise on foraging behavior 
(Miller et al., 2009). Captive bottlenose dolphins sometimes vocalized 
after an exposure to impulse sound from a seismic watergun (Finneran et 
al., 2010a).
    A review of behavioral reactions by pinnipeds to impulse noise can 
be found in Richardson et al. (1995) and Southall et al. (2007). 
Blackwell et al. (2004) observed that ringed seals exhibited little or 
no reaction to pipe-driving noise with mean underwater levels of 157 dB 
re 1 [mu]Pa rms and in air levels of 112 dB re 20 [mu]Pa, suggesting 
that the seals had habituated to the noise. In contrast, captive 
California sea lions avoided sounds from an impulse source at levels of 
165-170 dB re 1 [mu]Pa (Finneran et al., 2003b). Experimentally, 
G[ouml]tz and Janik (2011) tested underwater, startle responses to a 
startling sound (sound with a rapid rise time and a 93 dB sensation 
level [the level above the animal's threshold at that frequency]) and a 
non-startling sound (sound with the same level, but with a slower rise 
time) in wild-captured gray seals. The animals exposed to the startling 
treatment avoided a known food source, whereas animals exposed to the 
non-startling treatment did not react or habituated during the exposure 
period. The results of this study highlight the importance of the 
characteristics of the acoustic signal in an animal's response of 
habituation.

Vessels

    Commercial and Navy ship strikes of cetaceans can cause major 
wounds, which may lead to the death of the animal. An animal at the 
surface could be struck directly by a vessel, a surfacing animal could 
hit the bottom of a vessel, or an animal just below the surface could 
be cut by a vessel's propeller. The severity of injuries typically 
depends on the size and speed of the vessel (Knowlton and Kraus, 2001; 
Laist et al., 2001; Vanderlaan and Taggart, 2007). The most vulnerable 
marine mammals are those that spend extended periods of time at the 
surface in order to restore oxygen levels within their tissues after 
deep dives (e.g., the sperm whale). In addition, some baleen whales, 
such as the North Atlantic right whale, seem generally unresponsive to 
vessel sound, making them more susceptible to vessel collisions 
(Nowacek et al., 2004). These species are primarily large, slow moving 
whales. Smaller marine mammals (e.g., bottlenose dolphin) move quickly 
through the water column and are often seen riding the bow wave of 
large ships. Marine mammal responses to vessels may include avoidance 
and changes in dive pattern (NRC, 2003).
    An examination of all known ship strikes from all shipping sources 
(civilian and military) indicates vessel speed is a principal factor in 
whether a vessel strike results in death (Knowlton and Kraus, 2001; 
Laist et al., 2001; Jensen and Silber, 2003; Vanderlaan and Taggart, 
2007). In assessing records in which vessel speed was known, Laist et 
al. (2001) found a direct relationship between the occurrence of a 
whale strike and the speed of the vessel involved in the collision. The 
authors concluded that most deaths occurred when a vessel was traveling 
in excess of 13 knots.
    Jensen and Silber (2003) detailed 292 records of known or probable 
ship strikes of all large whale species from 1975 to 2002. Of these, 
vessel speed at the time of collision was reported for 58 cases. Of 
these cases, 39 (or 67 percent) resulted in serious injury or death (19 
of those resulted in serious injury as determined by blood in the 
water, propeller gashes or severed tailstock, and fractured skull, jaw, 
vertebrae, hemorrhaging, massive bruising or other injuries noted 
during necropsy and 20 resulted in death). Operating speeds of vessels 
that struck various species of large whales ranged from 2 to 51 knots. 
The majority (79 percent) of these strikes occurred at speeds of 13 
knots or greater. The average speed that resulted in serious injury or 
death was 18.6 knots. Pace and Silber (2005) found that the probability 
of death or serious injury increased rapidly with increasing vessel 
speed. Specifically, the predicted probability of serious injury or 
death increased from 45 to 75 percent as vessel speed increased from 10 
to 14 knots, and exceeded 90 percent at 17 knots. Higher speeds during 
collisions result in greater force of impact and also appear to 
increase the chance of severe injuries or death. While modeling studies 
have suggested that hydrodynamic forces pulling whales toward the 
vessel hull increase with increasing speed (Clyne, 1999; Knowlton et 
al., 1995), this is inconsistent with Silber et al. (2010), which 
demonstrated that there is no such relationship (i.e., hydrodynamic 
forces are independent of speed).
    The Jensen and Silber (2003) report notes that the database 
represents a minimum number of collisions, because the vast majority 
probably goes undetected or unreported. In contrast, Navy vessels are 
likely to detect any strike that does occur, and they are required to 
report all ship strikes involving marine mammals. Overall, the 
percentages of Navy traffic relative to overall large shipping traffic 
are very small (on the order of 2 percent).
    There are no records of any Navy vessel strikes to marine mammals 
during training or testing activities in the NWTT Study Area. There has 
been only one whale strike in the Pacific Northwest by the Navy since 
such records have been kept (June 1994-present). In August 2012, a San 
Diego homeported DDG (destroyer) at-sea about 35 nm west of Coos Bay, 
Oregon struck a whale (believed to be a minke) while transiting to San 
Diego from Seattle. There have been Navy strikes of large whales in 
areas outside the Study Area, such as Hawaii and Southern California. 
However, these areas differ significantly from the Study Area given 
that both Hawaii and Southern

[[Page 31769]]

California have a much higher number of Navy vessel activities.
    Other efforts have been undertaken to investigate the impact from 
vessels (both whale-watching and general vessel traffic noise) and 
demonstrated impacts do occur (Bain, 2002; Erbe, 2002; Lusseau, 2009; 
Williams et al., 2006, 2009, 2011b, 2013, 2014a, 2014b; Noren et al., 
2009; Read et al., 2014; Rolland et al., 2012; Pirotta et al., 2015). 
This body of research for the most part has investigated impacts 
associated with the presence of chronic stressors, which differ 
significantly from generally intermittent Navy training and testing 
activities. For example, in an analysis of energy costs to killer 
whales, Williams et al. (2009) suggested that whale-watching in the 
Johnstone Strait resulted in lost feeding opportunities due to vessel 
disturbance, which could carry higher costs than other measures of 
behavioral change might suggest. Ayres et al. (2012) recently reported 
on research in the Salish Sea involving the measurement of southern 
resident killer whale fecal hormones to assess two potential threats to 
the species recovery: Lack of prey (salmon) and impacts to behavior 
from vessel traffic. Ayres et al. (2012) suggested that the lack of 
prey overshadowed any population-level physiological impacts on 
southern resident killer whales from vessel traffic.

Marine Mammal Habitat

    The Navy's proposed training and testing activities could 
potentially affect marine mammal habitat through the introduction of 
sound into the water column, impacts to the prey species of marine 
mammals, bottom disturbance, or changes in water quality. Each of these 
components was considered in the January 2014 NWTT DEIS/OEIS and was 
determined by the Navy to have no effect on marine mammal habitat. 
Based on the information below and the supporting information included 
in the January 2014 NWTT DEIS/OEIS, NMFS has preliminarily determined 
that the proposed training and testing activities would not have 
adverse or long-term impacts on marine mammal habitat.

Critical Habitat

    The southern resident killer whale (in the inshore area) is the 
only ESA-listed marine mammal species with designated critical habitat 
located in the Study Area. The majority of the Navy's proposed training 
and testing activities would, however, not occur in the southern 
resident killer whale's designated critical habitat (NMFS, 2006). For 
all substressors that would occur within the critical habitat, those 
training and testing activities are not expected to impact the 
identified primary constituent elements of that habitat and therefore 
would have no effect on that critical habitat. Effects to designated 
critical habitat will be fully analyzed in the Navy's and NMFS' 
internal ESA Section 7 consultations for NWTT.

Expected Effects on Habitat

    Unless the sound source or explosive detonation is stationary and/
or continuous over a long duration in one area, the effects of the 
introduction of sound into the environment are generally considered to 
have a less severe impact on marine mammal habitat than the physical 
alteration of the habitat. Acoustic exposures are not expected to 
result in long-term physical alteration of the water column or bottom 
topography, as the occurrences are of limited duration and are 
intermittent in time. Surface vessels associated with the activities 
are present in limited duration and are intermittent as they move 
relatively rapidly through any given area. Most of the high-explosive 
military expended materials would detonate at or near the water 
surface. Only bottom-laid explosives are likely to affect bottom 
substrate; habitat used for underwater detonations and seafloor device 
placement would primarily be soft-bottom sediment. Once on the 
seafloor, military expended material would likely be colonized by 
benthic organisms because the materials would serve as anchor points in 
the shifting bottom substrates, similar to a reef. The surface area of 
bottom substrate affected would make up a very small percentage of the 
total training area available in the NWTT Study Area.

Effects on Marine Mammal Prey

    Invertebrates--Marine invertebrate distribution in the NWTT Study 
Area is influenced by habitat, ocean currents, and water quality 
factors such as temperature, salinity, and nutrient content (Levinton, 
2009). The distribution of invertebrates is also influenced by their 
distance from the equator (latitude); in general, the number of marine 
invertebrate species increases toward the equator (Macpherson, 2002). 
The higher number of species (diversity) and abundance of marine 
invertebrates in coastal habitats, compared with the open ocean, is a 
result of more nutrient availability from terrestrial environments and 
the variety of habitats and substrates found in coastal waters 
(Levinton, 2009).
    Marine invertebrates in the Study Area inhabit coastal waters and 
benthic habitats, including salt marshes, kelp forests, soft sediments, 
canyons, and the continental shelf. Salt marsh invertebrates include 
oysters, crabs, and worms that are important prey for birds and small 
mammals. Mudflats provide habitat for substantial amounts of 
crustaceans, bivalves, and worms. The sandy intertidal area is 
dominated by species that are highly mobile and can burrow. One of the 
most abundant invertebrates found in the near shore areas of the Study 
Area on soft sediments are geoduck clams (Panopea generosa).
    All marine invertebrate taxonomic groups are represented in the 
NWTT Study Area. Major invertebrate phyla (taxonomic range)--those with 
greater than 1,000 species and the general zones they inhabit in the 
Study Area are described in Chapter 3 of the January 2014 NWTT DEIS/
OEIS.
    Very little is known about sound detection and use of sound by 
aquatic invertebrates (Budelmann 2010; Montgomery et al., 2006; Popper 
et al., 2001). Organisms may detect sound by sensing either the 
particle motion or pressure component of sound, or both. Aquatic 
invertebrates probably do not detect pressure since many are generally 
the same density as water and few, if any, have air cavities that would 
function like the fish swim bladder in responding to pressure 
(Budelmann, 2010; Popper et al., 2001). Many marine invertebrates, 
however, have ciliated ``hair'' cells that may be sensitive to water 
movements, such as those caused by currents or water particle motion 
very close to a sound source (Budelmann, 2010; Mackie and Singla, 
2003). These cilia may allow invertebrates to sense nearby prey or 
predators or help with local navigation. Marine invertebrates may 
produce and use sound in territorial behavior, to deter predators, to 
find a mate, and to pursue courtship (Popper et al., 2001).
    Both behavioral and auditory brainstem response studies suggest 
that crustaceans may sense sounds up to three kilohertz (kHz), but best 
sensitivity is likely below 200 Hz (Lovell et al., 2005; Lovell et al., 
2006; Goodall et al., 1990). Most cephalopods (e.g., octopus and squid) 
likely sense low-frequency sound below 1,000 Hz, with best 
sensitivities at lower frequencies (Budelmann, 2010; Mooney et al., 
2010; Packard et al., 1990). A few cephalopods may sense higher 
frequencies up to 1,500 Hz (Hu et al., 2009). Squid did not respond to 
toothed whale ultrasonic echolocation clicks at sound pressure levels 
ranging from 199 to 226 dB re 1 [mu]Pa peak-to-peak, likely because 
these clicks were outside of squid hearing range (Wilson et al.,

[[Page 31770]]

2007). However, squid exhibited alarm responses when exposed to 
broadband sound from an approaching seismic airgun with received levels 
exceeding 145 to 150 dB re 1 [mu]Pa root mean square (McCauley et al., 
2000b).
    Little information is available on the potential impacts on marine 
invertebrates of exposure to sonar, explosions, and other sound-
producing activities. It is expected that most marine invertebrates 
would not sense mid- or high-frequency sounds, distant sounds, or 
aircraft noise transmitted through the air-water interface. Most marine 
invertebrates would not be close enough to intense sound sources, such 
as some sonars, to potentially experience impacts to sensory 
structures. Any marine invertebrate capable of sensing sound may alter 
its behavior if exposed to non-impulsive sound, although it is unknown 
if responses to non-impulsive sounds occur. Continuous noise, such as 
from vessels, may contribute to masking of relevant environmental 
sounds, such as reef noise. Because the distance over which most marine 
invertebrates are expected to detect any sounds is limited and vessels 
would be in transit, any sound exposures with the potential to cause 
masking or behavioral responses would be brief and long-term impacts 
are not expected. Although non-impulsive underwater sounds produced 
during training and testing activities may briefly impact individuals, 
intermittent exposures to non-impulsive sounds are not expected to 
impact survival, growth, recruitment, or reproduction of widespread 
marine invertebrate populations.
    Most detonations would occur greater than 3 nm from shore. As water 
depth increases away from shore, benthic invertebrates would be less 
likely to be impacted by detonations at or near the surface. In 
addition, detonations near the surface would release a portion of their 
explosive energy into the air, reducing the explosive impacts in the 
water. Some marine invertebrates may be sensitive to the low-frequency 
component of impulsive sound, and they may exhibit startle reactions or 
temporary changes in swim speed in response to an impulsive exposure. 
Because exposures are brief, limited in number, and spread over a large 
area, no long-term impacts due to startle reactions or short-term 
behavioral changes are expected. Although individual marine 
invertebrates may be injured or killed during an explosion or pile 
driving, no long-term impacts on the survival, growth, recruitment, or 
reproduction of marine invertebrate populations are expected.
    Fish--Fish are not distributed uniformly throughout the NWTT Study 
Area, but are closely associated with a variety of habitats. Some 
species range across thousands of square miles while others have small 
home ranges and restricted distributions (Helfman et al., 2009). The 
movements of some open-ocean species may never overlap with coastal 
fishes that spend their lives within several hundred feet (a few 
hundred meters) of the shore. Even within a single fish species, the 
distribution and specific habitats in which individuals occur may be 
influenced by its developmental stage, size, sex, reproductive 
condition, and other factors.
    The distribution and abundance of fishes depends greatly on the 
physical and biological factors of the marine ecosystem, such as 
salinity, temperature, dissolved oxygen, population dynamics, predator 
and prey interaction oscillations, seasonal movements, reproduction and 
life cycles, and recruitment success (Helfman et al., 1997). A single 
factor is rarely responsible for the distribution of fish species; more 
often, a combination of factors is accountable. For example, open ocean 
species optimize their growth, reproduction, and survival by tracking 
gradients of temperature, oxygen, or salinity (Helfman et al., 1997). 
Another major component in understanding species distribution is the 
location of highly productive regions, such as frontal zones. These 
areas concentrate various prey species and their predators, such as 
tuna, and provide visual cues for the location of target species for 
commercial fisheries (NMFS, 2001).
    There are 17 major taxonomic groups of marine fishes within the 
NWTT Study Area. Detailed information on taxa presence, distribution, 
and characteristics are provided in Chapter 3 of the January 2014 NWTT 
DEIS/OEIS.
    All fish have two sensory systems to detect sound in the water: The 
inner ear, which functions very much like the inner ear in other 
vertebrates, and the lateral line, which consists of a series of 
receptors along the fish's body (Popper, 2008). The inner ear generally 
detects relatively higher-frequency sounds, while the lateral line 
detects water motion at low frequencies (below a few hundred Hz) 
(Hastings and Popper, 2005a). Although hearing capability data only 
exist for fewer than 100 of the 32,000 fish species, current data 
suggest that most species of fish detect sounds from 50 to 1,000 Hz, 
with few fish hearing sounds above 4 kHz (Popper, 2008). It is believed 
that most fish have their best hearing sensitivity from 100 to 400 Hz 
(Popper, 2003b). Additionally, some clupeids (shad in the subfamily 
Alosinae) possess ultrasonic hearing (i.e., able to detect sounds above 
100,000 Hz) (Astrup, 1999). Permanent hearing loss, or permanent 
threshold shift has not been documented in fish. The sensory hair cells 
of the inner ear in fish can regenerate after they are damaged, unlike 
in mammals where sensory hair cells loss is permanent (Lombarte et al., 
1993; Smith et al., 2006). As a consequence, any hearing loss in fish 
may be as temporary as the timeframe required to repair or replace the 
sensory cells that were damaged or destroyed (e.g., Smith et al., 
2006).
    Potential direct injuries from non-impulsive sound sources, such as 
sonar, are unlikely because of the relatively lower peak pressures and 
slower rise times than potentially injurious sources such as 
explosives. Non-impulsive sources also lack the strong shock waves 
associated with an explosion. Therefore, direct injury is not likely to 
occur from exposure to non-impulsive sources such as sonar, vessel 
noise, or subsonic aircraft noise. Only a few fish species are able to 
detect high-frequency sonar and could have behavioral reactions or 
experience auditory masking during these activities. These effects are 
expected to be transient and long-term consequences for the population 
are not expected. MFAS is unlikely to impact fish species because most 
species are unable to detect sounds in this frequency range and vessels 
operating MFAS would be transiting an area (not stationary). While a 
large number of fish species may be able to detect low-frequency sonar 
and other active acoustic sources, low-frequency active usage is rare 
and mostly conducted in deeper waters. Overall effects to fish from 
would be localized and infrequent.
    Physical effects from pressure waves generated by underwater sounds 
(e.g. underwater explosions) could potentially affect fish within 
proximity of training or testing activities. In particular, the rapid 
oscillation between high- and low-pressure peaks has the potential to 
burst the swim bladders and other gas-containing organs of fish (Keevin 
and Hemen, 1997). Sublethal effects, such as changes in behavior of 
fish, have been observed in several occasions as a result of noise 
produced by explosives (National Research Council of the National 
Academies, 2003; Wright, 1982). If an individual fish were repeatedly 
exposed to sounds from underwater explosions that caused alterations in 
natural behavioral patterns or physiological stress, these impacts 
could lead to long-term consequences for the individual such as

[[Page 31771]]

reduced survival, growth, or reproductive capacity. However, the time 
scale of individual explosions is very limited, and training exercises 
involving explosions are dispersed in space and time. Consequently, 
repeated exposure of individual fish to sounds from underwater 
explosions is not likely and most acoustic effects are expected to be 
short-term and localized. Long-term consequences for populations would 
not be expected. A limited number of fish may be killed in the 
immediate proximity of pile driving locations and additional fish may 
be injured. Short-term effects such as masking, stress, behavioral 
change, and hearing threshold shifts are also expected during pile 
driving operations. However, given the relatively small area that would 
be affected, and the abundance and distribution of the species 
concerned, no population-level effects are expected. The abundances of 
various fish and invertebrates near the detonation point of an 
explosion or around a pile driving location could be altered for a few 
hours before animals from surrounding areas repopulate the area; 
however these populations would be replenished as waters near the sound 
source are mixed with adjacent waters.

Marine Mammal Avoidance

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

Other Expected Effects

    Other sources that may affect marine mammal habitat were considered 
in the January 2014 NWTT DEIS/OEIS and potentially include the 
introduction of fuel, debris, ordnance, and chemical residues into the 
water column. The majority of high-order explosions would occur at or 
above the surface of the ocean, and would have no impacts on sediments 
and minimal impacts on water quality. While disturbance or strike from 
an item falling through the water column is possible, it is unlikely 
because (1) objects sink slowly, (2) most projectiles are fired at 
targets (and hit those targets), and (3) animals are generally widely 
dispersed throughout the water column and over the NWTT Study Area. 
Chemical, physical, or biological changes in sediment or water quality 
would not be detectable. In the event of an ordnance failure, the 
energetic materials it contained would remain mostly intact. The 
explosive materials in failed ordnance items and metal components from 
training and testing would leach slowly and would quickly disperse in 
the water column. Chemicals from other explosives would not be 
introduced into the water column in large amounts and all torpedoes 
would be recovered following training and testing activities, reducing 
the potential for chemical concentrations to reach levels that can 
affect sediment quality, water quality, or benthic habitats.

Proposed Mitigation

    In order to issue an incidental take authorization under section 
101(a)(5)(A) of the MMPA, NMFS must set forth the ``permissible methods 
of taking pursuant to such activity, and other means of effecting the 
least practicable adverse impact on such species or stock and its 
habitat, paying particular attention to rookeries, mating grounds, and 
areas of similar significance.'' NMFS' duty under this ``least 
practicable adverse impact'' standard is to prescribe mitigation 
reasonably designed to minimize, to the extent practicable, any adverse 
population-level impacts, as well as habitat impacts. While population-
level impacts can be minimized by reducing impacts on individual marine 
mammals, not all takes translate to population-level impacts. NMFS' 
primary objective under the ``least practicable adverse impact'' 
standard is to design mitigation targeting those impacts on individual 
marine mammals that are most likely to lead to adverse population-level 
effects.
    The NDAA of 2004 amended the MMPA as it relates to military-
readiness activities and the ITA process such that ``least practicable 
adverse impact'' shall include consideration of personnel safety, 
practicality of implementation, and impact on the effectiveness of the 
``military readiness activity.'' The training and testing activities 
described in the LOA application are considered military readiness 
activities.
    NMFS reviewed the proposed activities and the proposed mitigation 
measures as described in the LOA application to determine if they would 
result in the least practicable adverse effect on marine mammals, which 
includes a careful balancing of the likely benefit of any particular 
measure to the marine mammals with the likely effect of that measure on 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the ``military-readiness activity.'' Included below 
are the mitigation measures the Navy proposed in their LOA application. 
NMFS worked with the Navy to develop these proposed measures, and they 
are informed by years of experience and monitoring. In addition, the 
adaptive management process (see Adaptive management) and annual 
meetings between NMFS and the Navy allows NMFS to consider new 
information from different sources to determine (with input from the 
Navy regarding practicability) on an annual or biennial basis if 
mitigation measures should be refined or modified.
    The Navy's proposed mitigation measures are modifications to the 
proposed activities that are implemented for the sole purpose of 
reducing a specific potential environmental impact on a particular 
resource. These do not include standard operating procedures, which are 
established for reasons other than environmental benefit. Most of the 
following proposed mitigation measures are currently, or were 
previously, implemented as a result of past environmental compliance 
documents. The Navy's overall approach to assessing potential 
mitigation measures is based on two principles: (1) Mitigation measures 
will be effective at reducing potential impacts on the resource, and 
(2) from a military perspective, the mitigation measures are 
practicable, executable, and safety and readiness will not be impacted.
Lookouts
    The use of Lookouts is a critical component of Navy procedural 
measures and implementation of mitigation zones. Navy Lookouts are 
highly qualified and experienced observers of the marine environment. 
Their duties require that they report all objects sighted in the water 
to the Officer of the Deck (OOD) (e.g., trash, a periscope, marine 
mammals, sea turtles) and all disturbances (e.g., surface disturbance, 
discoloration) that may be indicative of a threat to the vessel and its 
crew. There are personnel standing watch on station at all times (day 
and night) when a ship or surfaced submarine is moving through the 
water.
    The Navy would have two types of Lookouts for the purposes of 
conducting visual observations: (1) Those positioned on surface ships, 
and (2)

[[Page 31772]]

those positioned ashore, in aircraft or on boats. Lookouts positioned 
on surface ships would be dedicated solely to diligent observation of 
the air and surface of the water. They would have multiple observation 
objectives, which include but are not limited to detecting the presence 
of biological resources and recreational or fishing boats, observing 
mitigation zones, and monitoring for vessel and personnel safety 
concerns.
    Due to manning and space restrictions on aircraft, small boats, and 
some Navy ships, Lookouts for these platforms may be supplemented by 
the aircraft crew or pilot, boat crew, range site personnel, or shore-
side personnel. Lookouts positioned in minimally manned platforms may 
be responsible for tasks in addition to observing the air or surface of 
the water (e.g., navigation of a helicopter or small boat). However, 
all Lookouts will (considering personnel safety, practicality of 
implementation, and impact on the effectiveness of the activity) comply 
with the observation objectives described above for Lookouts positioned 
on ships.
    The procedural measures described below primarily consist of having 
Lookouts during specific training and testing activities.
    All personnel standing watch on the bridge, Commanding Officers, 
Executive Officers, maritime patrol aircraft aircrews, 
anti[hyphen]submarine warfare helicopter crews, civilian equivalents, 
and Lookouts will successfully complete the United States Navy Marine 
Species Awareness Training prior to standing watch or serving as a 
Lookout. Additional details on the Navy's Marine Species Awareness 
Training can be found in the NWTT Draft EIS/OEIS.
    The Navy proposes to use one or more Lookouts during the training 
and testing activities provided in Table 10. Additional details on 
Lookout procedures and implementation are provided in Chapter 11 of the 
LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm).

     Table 10--Lookout Mitigation Measures for Training and Testing
                  Activities Within the NWTT Study Area
------------------------------------------------------------------------
        Number of  lookouts            Training and testing activities
------------------------------------------------------------------------
1-2................................  Low-Frequency and Non-Hull Mounted
                                      Mid-Frequency Active Sonar.
1..................................  High-Frequency and Hull Mounted Mid-
                                      Frequency Active Sonar.
1..................................  Improved Extended Echo Ranging
                                      Sonobuoys (testing only).
1..................................  Explosive Signal Underwater Sound
                                      Buoys Using >0.5-2.5 Pound Net
                                      Explosive Weight.
2..................................  Mine Countermeasures and
                                      Neutralization Activities Using
                                      Positive Control Firing Devices
                                      (training only).
1-2................................  Gunnery Exercises Using Surface
                                      Target (training only).
1..................................  Missile Exercises Using Surface
                                      Target (training only).
1 (minimum)........................  Bombing Exercises--Explosive
                                      (training only).
1..................................  Torpedo--Explosive (testing
                                      only).\1\
1..................................  Weapons Firing Noise During Gunnery
                                      Exercises (training only).
1 (minimum)........................  Vessel Movement.
1..................................  Towed In-Water Strike.
1..................................  Gunnery Exercises--Non-Explosive
                                      (training only).
1..................................  Bombing Exercises--Non-Explosive
                                      (training only).
------------------------------------------------------------------------
\1\ For explosive torpedo tests from aircraft, the Navy will have one
  Lookout positioned in an aircraft; for explosive torpedoes tested from
  a surface ship, the Navy is proposing to use the Lookout procedures
  currently implemented for hull-mounted mid-frequency active sonar
  activities.

Mitigation Zones

    The Navy proposes to use mitigation zones to reduce the potential 
impacts to marine mammals from training and testing activities. 
Mitigation zones are measured as the radius from a source and represent 
a distance that the Navy would monitor. Mitigation zones are applied to 
acoustic stressors (i.e., non-impulsive and impulsive sound) and 
physical strike and disturbance (e.g., vessel movement and bombing 
exercises). In each instance, visual detections of marine mammals would 
be communicated immediately to a watch station for information 
dissemination and appropriate action. Acoustic detections would be 
communicated to Lookouts posted in aircraft and on surface vessels.
    Most of the current mitigation zones for activities that involve 
the use of impulsive and non-impulsive sources were originally designed 
to reduce the potential for onset of TTS. The Navy updated their 
acoustic propagation modeling to incorporate new hearing threshold 
metrics (i.e., upper and lower frequency limits), new marine mammal 
density data, and factors such as an animal's likely presence at 
various depths. An explanation of the acoustic propagation modeling 
process can be found in previous authorizations for the Atlantic Fleet 
Training and Testing Study Area; the Hawaii-Southern California 
Training and Testing Study Area; and the Determination of Acoustic 
Effects on Marine Mammals and Sea Turtles for the Northwest Training 
and Testing EIS/OEIS technical report (Marine Species Modeling Team, 
2013).
    As a result of the updates to the acoustic propagation modeling, in 
some cases the ranges to onset of TTS effects are much larger than 
previous model outputs. Due to the ineffectiveness and unacceptable 
operational impacts associated with mitigating these large areas, the 
Navy is unable to mitigate for onset of TTS for every activity. For the 
NWTT analysis, the Navy developed each recommended mitigation zone to 
avoid or reduce the potential for onset of the lowest level of injury, 
PTS, out to the predicted maximum range. In some cases where the ranges 
to effects are smaller than previous models estimated, the mitigation 
zones were adjusted accordingly to provide consistency across the 
measures. Mitigating to the predicted maximum range to PTS consequently 
also mitigates to the predicted maximum range to onset mortality (1 
percent mortality), onset slight lung injury, and onset slight 
gastrointestinal tract injury, since the maximum range to effects for 
these criteria are shorter than for PTS. Furthermore, in most cases, 
the predicted maximum range to PTS also consequently covers the 
predicted average range to TTS. Table 11 summarizes the predicted 
average range to TTS, average range to PTS, maximum range to PTS, and 
recommended mitigation zone for each activity category, based on the 
Navy's acoustic propagation modeling results. The predicted ranges are 
based on local environmental conditions and are unique to the NWTT 
Study Area.
    The Navy's proposed mitigation zones are based on the longest range 
for all the

[[Page 31773]]

marine mammal and sea turtle functional hearing groups. Most mitigation 
zones were driven by the high-frequency cetacean or sea turtle 
functional hearing group. Therefore, the mitigation zones are more 
conservative for the remaining functional hearing groups (low-frequency 
and mid-frequency cetaceans, and pinnipeds), and likely cover a larger 
portion of the potential range to onset of TTS. Additional information 
on the estimated range to effects for each acoustic stressor is 
detailed in Chapter 11 of the LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm).

                           Table 11--Predicted Ranges to TTS, PTS, and Recommended Mitigation Zones for Each Activity Category
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                       Bin (representative     Predicted  average     Predicted  average     Predicted  maximum   Recommended mitigation
         Activity category                 source) \1\            range to TTS           range to PTS           range to PTS               zone
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Non-Impulsive Sound
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-Frequency and Hull-Mounted Mid-  SQS-53 ASW hull-        4,251 yd. (3,887 m)..  281 yd. (257 m)......  <292 yd. (<267 m)....  Training: 1,000 yd.
 Frequency Active Sonar.\2\           mounted sonar (MF1).                                                                         (920 m) and 500 yd.
                                                                                                                                   (460 m) power downs
                                                                                                                                   and 200 yd. (180 m)
                                                                                                                                   shutdown for
                                                                                                                                   cetaceans, 100 yd.
                                                                                                                                   (90 m) mitigation
                                                                                                                                   zone for pinnipeds.
                                                                                                                                  Testing: 1,000 yd.
                                                                                                                                   (920 m) and 500 yd.
                                                                                                                                   (460 m) power downs
                                                                                                                                   for sources that can
                                                                                                                                   be powered down and
                                                                                                                                   200 yd. (180 m)
                                                                                                                                   shutdown for
                                                                                                                                   cetaceans, 100 yd.
                                                                                                                                   (90 m) for pinnipeds
                                                                                                                                   (excludes haulouts).
High-Frequency and Non-Hull-Mounted  AQS-22 ASW dipping      226 yd. (207 m)......  <55 yd. (<50 m)......  <55 yd. (<50 m)......  Training: 200 yd. (180
 Mid-Frequency Active Sonar.\2\       sonar (MF4).                                                                                 m).
                                                                                                                                  Testing: 200 yd. (180
                                                                                                                                   m) for cetaceans, 100
                                                                                                                                   yd. (90 m) for
                                                                                                                                   pinnipeds (excludes
                                                                                                                                   haulouts).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                              Explosive and Impulsive Sound
--------------------------------------------------------------------------------------------------------------------------------------------------------
Improved Extended Echo Ranging       Explosive sonobuoy      237 yd. (217 m)......  133 yd. (122 m)......  235 yd. (215 m)......  Training: n/a
 Sonobuoys.                           (E4).                                                                                       Testing: 600 yd. (550
                                                                                                                                   m) for marine
                                                                                                                                   mammals, sea turtles,
                                                                                                                                   and concentrations of
                                                                                                                                   floating vegetation.
Signal Underwater Sound (SUS) buoys  Explosive sonobuoy      178 yd. (163 m)......  92 yd. (84 m)........  214 yd. (196 m)......  Training: 350 yd. (320
 using >0.5-2.5 lb. NEW.              (E3).                                                                                        m) for marine
                                                                                                                                   mammals, sea turtles,
                                                                                                                                   and concentrations of
                                                                                                                                   floating vegetation.
                                                                                                                                  Testing: 350 yd. (320
                                                                                                                                   m) for marine
                                                                                                                                   mammals, sea turtles,
                                                                                                                                   and concentrations of
                                                                                                                                   floating vegetation.
Mine Countermeasure and              >0.5 to 2.5 lb NEW      495 yd. (453 m)......  145 yd. (133 m)......  373 yd. (341 m)......  Training: 400 yd. (336
 Neutralization Activities            (E3).                                                                                        m).
 (positive control).                                                                                                              Testing: n/a.
Gunnery Exercises--Small- and        25 mm projectile (E1).  72 yd. (66 m)........  48 yd. (44 m)........  73 yd. (67 m)........  Training: 200 yd. (180
 Medium-Caliber (Surface Target).                                                                                                  m).
                                                                                                                                  Testing: n/a.
Gunnery Exercises--Large-Caliber     5 in. projectiles (E5   210 yd. (192 m)......  110 yd. (101 m)......  177 yd. (162 m)......  Training: 600 yd. (550
 (Surface Target).                    at the surface).\3\                                                                          m).
                                                                                                                                  Testing: 600 yd. (550
                                                                                                                                   m).
Missile Exercises up to 500 lb. NEW  Harpoon missile (E10).  1,164 yd. (1,065 m)..  502 yd. (459 m)......  955 yd. (873 m)......  Training: 2,000 yd.
 (Surface Target).                                                                                                                 (1.8 km).
                                                                                                                                  Testing: n/a.
Bombing Exercises..................  MK-84 2,000 lb. bomb    1,374 yd. (1,256 m)..  591 yd. (540 m)......  1,368 yd. (1,251 m)..  Training: 2,500 yd.
                                      (E12).                                                                                       (2.3 km).
                                                                                                                                  Testing: n/a.
Lightweight Torpedo (Explosive)      MK-46 torpedo (E8)....  497 yd. (454 m)......  245 yd. (224 m)......  465 yd. (425 m)......  Training: n/a.
 Testing.                                                                                                                         Testing: 2,100 yd.
                                                                                                                                   (1.9 km).
Heavyweight Torpedo (Explosive)      MK-48 torpedo (E11)...  1,012 yd. (926 m)....  472 yd. (432 m)......  885 yd. (809 m)......  Training: n/a.
 Testing.                                                                                                                         Testing: 2,100 yd.
                                                                                                                                   (1.9 km).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ This table does not provide an inclusive list of source bins; bins presented here represent the source bin with the largest range to effects within
  the given activity category.
\2\ High-frequency and non-hull-mounted mid-frequency active sonar category includes unmanned underwater vehicle and torpedo testing activities.
\3\ The representative source Bin E5 has different range to effects depending on the depth of activity occurrence (at the surface or at various depths).
Notes: ASW = anti-submarine warfare, in. = inch, km = kilometer, m = meter, mm = millimeter, n/a = Not Applicable, NEW = net explosive weight, PTS =
  permanent threshold shift, TTS = temporary threshold shift, yd. = yard.


[[Page 31774]]

Low-Frequency and Hull-Mounted Mid-Frequency Active Sonar Training

    There are no low-frequency active sonar training activities 
proposed in the Study Area. The Navy is proposing to (1) continue 
implementing the current measures for mid-frequency active sonar, (2) 
clarify the conditions needed to recommence an activity after a 
sighting, and (3) implement mitigation measures for pinnipeds and for 
pierside sonar testing in the vicinity of hauled out pinnipeds.
    Activities that involve the use of hull-mounted mid-frequency 
active sonar (including pierside) will use Lookouts for visual 
observation from a ship immediately before and during the activity. 
Mitigation zones for these activities involve powering down the sonar 
by 6 dB when a marine mammal is sighted within 1,000 yd. (920 m) of the 
sonar dome, and by an additional 4 dB when sighted within 500 yd. (460 
m) from the source, for a total reduction of 10 dB. Active 
transmissions will cease if a marine mammal is sighted within 200 yd. 
(180 m). Active transmission will recommence if any one of the 
following conditions is met: (1) The animal is observed exiting the 
mitigation zone, (2) the animal is thought to have exited the 
mitigation zone based on its course and speed, (3) the mitigation zone 
has been clear from any additional sightings for a period of 30 
minutes, (4) the ship has transited more than 2,000 yd. (1.8 km) beyond 
the location of the last sighting, or (5) the Lookout concludes that 
dolphins are deliberately closing in on the ship to ride the ship's bow 
wave (and there are no other marine mammal sightings within the 
mitigation zone). Active transmission may resume when dolphins are bow 
riding because they are out of the main transmission axis of the active 
sonar while in the shallow-wave area of the ship bow.
    For pinnipeds, the Navy proposes a 100 yd. (90 m) mitigation zone 
for activities that involve the use of hull-mounted mid-frequency 
active sonar. The pinniped mitigation zone does not apply for pierside 
testing in the vicinity of pinnipeds hauled out on man-made structures 
and vessels. Within Puget Sound there are several locations where 
pinnipeds use Navy structures (e.g., submarines, security barriers) for 
haulouts in spite of the degree of activity surrounding these sites. 
Given that animals continue to choose these areas for their resting 
behavior, it would appear there are no long-term effects or 
consequences to those animals as a result of ongoing and routine Navy 
activities.
Testing
    There are no current hull-mounted mid-frequency active sonar 
testing activities in the Study Area, and no mitigation procedures. 
However, the Navy's Proposed Action includes newly assessed hull-
mounted mid-frequency active sonar testing activities. For testing 
activities, the recommended measures are provided below.
    Activities that involve the use of low-frequency active sonar 
(including pierside) will use Lookouts for visual observation 
immediately before and during the event. If a marine mammal is sighted 
within 200 yd. (180 m) of the sound source, active transmissions will 
cease. Active transmission will recommence if any one of the following 
conditions is met: (1) The animal is observed exiting the mitigation 
zone, (2) the animal is thought to have exited the mitigation zone 
based on its course and speed, (3) the mitigation zone has been clear 
from any additional sightings for a period of 30 minutes, or (4) the 
sound source has transited more than 2,000 yd. (1.8 km) beyond the 
location of the last sighting.
    Activities that involve the use of hull-mounted mid-frequency 
active sonar (including pierside and shore-based testing) will follow 
the mitigation measures described above for Low-Frequency and Hull-
Mounted Mid-Frequency Active Sonar Training.
    For pinnipeds, the Navy proposes a 100 yd. mitigation zone. The 
pinniped mitigation zone does not apply for pierside testing in the 
vicinity of pinnipeds hauled out on man-made structures and vessels.

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

    Non-hull-mounted mid-frequency active sonar training activities 
include the use of aircraft deployed sonobuoys and helicopter dipping 
sonar. The Navy is proposing to: (1) Continue implementing the current 
mitigation measures for activities currently being executed, such as 
dipping sonar activities; (2) extend the implementation of its current 
mitigation to all other activities in this category; and (3) clarify 
the conditions needed to recommence an activity after a sighting.
    Mitigation will include visual observation from a vessel or 
aircraft (with the exception of platforms operating at high altitudes) 
immediately before and during active transmission within a mitigation 
zone of 200 yd. (180 m) from the active sonar source. For activities 
involving helicopter deployed dipping sonar, visual observation will 
commence 10 minutes before the first deployment of active dipping 
sonar. Helicopter dipping and sonobuoy deployment will not begin if 
concentrations of floating vegetation (kelp paddies), are observed in 
the mitigation zone. If the source can be turned off during the 
activity, active transmission will cease if a marine mammal is sighted 
within the mitigation zone. Active transmission will recommence if any 
one of the following conditions is met: (1) The animal is observed 
exiting the mitigation zone, (2) the animal is thought to have exited 
the mitigation zone based on its course and speed, (3) the mitigation 
zone has been clear from any additional sightings for a period of 10 
minutes for an aircraft-deployed source, (4) the mitigation zone has 
been clear from any additional sightings for a period of 30 minutes for 
a vessel-deployed source, (5) the vessel or aircraft has repositioned 
itself more than 400 yd. (370 m) away from the location of the last 
sighting, or (6) the vessel concludes that dolphins are deliberately 
closing in to ride the vessel's bow wave (and there are no other marine 
mammal sightings within the mitigation zone).
Testing
    Mitigation measures for high-frequency active sonar sources 
currently exist only for testing activities conducted in the Inland 
Waters of Puget Sound and in the Western Behm Canal, Alaska. These 
activities include the use of unmanned vehicles, non-explosive 
torpedoes, and similar systems. Currently, the mitigation measures for 
testing activities using high frequency and non-hull-mounted mid-
frequency sources are the same as those currently in place for testing 
activities with low frequency sources.
    For the proposed action, the Navy is proposing that testing 
activities with high frequency and non-hull-mounted mid-frequency 
sources employ the proposed mitigation measures described above for 
training.
    For pinnipeds, the Navy proposes a 100 yd. (90 m) mitigation zone 
during testing. The pinniped mitigation zone does not apply for 
pierside or shore-based testing in the vicinity of pinnipeds hauled out 
on man-made structures and vessels. Within Puget Sound there are 
several locations where pinnipeds use Navy structures (e.g., 
submarines, security barriers) for haulouts in spite of the degree of 
activity surrounding these sites. Given that animals continue to choose 
these areas for their resting behavior, it would appear there are no 
long-term effects or consequences to those animals as a

[[Page 31775]]

result of ongoing and routine Navy activities.

Improved Extended Echo Ranging Sonobuoys

Training
    The Navy's proposed action does not include Improved Extended Echo 
Ranging sonobuoy training activities.
Testing
    The Navy is proposing to (1) modify the mitigation measures 
currently implemented for this activity by reducing the marine mammal 
mitigation zone from 1,000 yd. (920 m) to 600 yd. (550 m), (2) clarify 
the conditions needed to recommence an activity after a sighting, and 
(3) adopt the marine mammal mitigation zone size for floating 
vegetation for ease of implementation. The recommended measures are 
provided below.
    Mitigation will include pre-testing aerial observation and passive 
acoustic monitoring, which will begin 30 minutes before the first 
source/receiver pair detonation and continue throughout the duration of 
the test. The pre-testing aerial observation will include the time it 
takes to deploy the sonobuoy pattern (deployment is conducted by 
aircraft dropping sonobuoys in the water). Improved Extended Echo 
Ranging sonobuoys will not be deployed if concentrations of floating 
vegetation (kelp paddies) are observed in the mitigation zone around 
the intended deployment location. Explosive detonations will cease if a 
marine mammal or sea turtle is sighted within the mitigation zone. 
Detonations will recommence if any one of the following conditions is 
met: (1) The animal is observed exiting the mitigation zone, (2) the 
animal is thought to have exited the mitigation zone based on its 
course and speed, or (3) the mitigation zone has been clear from any 
additional sightings for a period of 30 minutes.
    Passive acoustic monitoring would be conducted with Navy assets, 
such as sonobuoys, already participating in the activity. These assets 
would only detect vocalizing marine mammals within the frequency bands 
monitored by Navy personnel. Passive acoustic detections would provide 
only limited range and bearing to detected animals, and therefore 
cannot provide locations of these animals. Passive acoustic detections 
would be reported to Lookouts posted in aircraft and on vessels in 
order to increase vigilance of their visual surveillance.

Explosive Signal Underwater Sound Buoys Using >0.5-2.5 Pound Net 
Explosive Weight

Training
    The Navy is proposing to add the following recommended measures. 
Mitigation will include pre-exercise aerial monitoring during 
deployment within a mitigation zone of 350 yd. (320 m) around an 
explosive SUS buoy. Explosive SUS buoys will not be deployed if 
concentrations of floating vegetation (kelp paddies) are observed in 
the mitigation zone (around the intended deployment location). SUS 
deployment will cease if a marine mammal or sea turtle is sighted 
within the mitigation zone. Deployment will recommence if any one of 
the following conditions is met: (1) The animal is observed exiting the 
mitigation zone, (2) the animal is thought to have exited the 
mitigation zone based on its course and speed, or (3) the mitigation 
zone has been clear from any additional sightings for a period of 10 
minutes.
    Passive acoustic monitoring will also be conducted with Navy 
assets, such as sonobuoys, already participating in the activity. These 
assets would only detect vocalizing marine mammals within the frequency 
bands monitored by Navy personnel. Passive acoustic detections would 
not provide range or bearing to detected animals, and therefore cannot 
provide locations of these animals. Passive acoustic detections would 
be reported to Lookouts posted in aircraft in order to increase 
vigilance of their visual surveillance.
Testing
    The Navy's proposed mitigation measures for testing activities are 
consistent with Navy training mitigation measures described above.

Mine Countermeasures and Neutralization Activities Using Positive 
Control Firing Devices

Training
    Mine countermeasure and neutralization activities in the Study Area 
involve the use of diver-placed charges that typically occur close to 
shore. When these activities are conducted using a positive control 
firing device, the detonation is controlled by the personnel conducting 
the activity and is not authorized until the area is clear at the time 
of detonation.
    Currently, the Navy employs the following mitigation zone 
procedures during mine countermeasure and neutralization activities 
using positive control firing devices:
     Mitigation Zone--The exclusion zone for marine mammals 
shall extend in a 700 yd. (640 m) arc radius around the detonation site 
for charges >0.5-2.5 lb. NEW.
     Pre-Exercise Surveys--For Demolition and Mine 
Countermeasures Operations, pre-exercise surveys shall be conducted 
within 30 minutes prior to the commencement of the scheduled explosive 
event. The survey may be conducted from the surface, by divers, or from 
the air, and personnel shall be alert to the presence of any marine 
mammal. Should such an animal be present within the survey area, the 
explosive event shall not be started until the animal voluntarily 
leaves the area. The Navy will ensure the mitigation zone is clear of 
marine mammals for a full 30 minutes prior to initiating the explosive 
event. Personnel will record any marine mammal observations during the 
exercise as well as measures taken if species are detected within the 
exclusion zone.
     Post-Exercise Surveys--Surveys within the same radius 
shall also be conducted within 30 minutes after the completion of the 
explosive event.
    For activities involving positive control diver-placed charges, the 
Navy is proposing to (1) modify the currently implemented mitigation 
measures for this activity involving >0.5-2.5 lb. NEW detonation by 
changing the mitigation zone from 700 yd. (640 m) to 400 yd. (366 m), 
(2) clarify the conditions needed to recommence an activity after a 
sighting, and (3) add a requirement to observe for floating vegetation. 
The recommended measures for activities involving positive control 
diver-placed activities are provided below.
    The Navy is proposing to use the 400 yd. (366 m) mitigation zones 
for marine mammals described above during activities involving positive 
control diver-placed charges involving >0.5-2.5 lb. NEW. Visual 
observation will be conducted by two small boats, each with a minimum 
of one surveyor.
    Explosive detonations will cease if a marine mammal is sighted in 
the water portion of the mitigation zone (i.e., not on shore). 
Detonations will recommence if any one of the following conditions is 
met: (1) The animal is observed exiting the mitigation zone, (2) the 
animal is thought to have exited the mitigation zone based on its 
course and speed, or (3) the mitigation zone has been clear from any 
additional sightings for a period of 30 minutes.
Testing
    The Navy's proposed action does not include mine countermeasure and 
neutralization testing activities.

[[Page 31776]]

Gunnery Exercises--Small and Medium-Caliber Using a Surface Target

Training
    The Navy is proposing to (1) continue implementing the current 
mitigation measures for this activity, (2) clarify the conditions 
needed to recommence an activity after a sighting, and (3) add a 
requirement to visually observe for kelp paddies.
    Mitigation will include visual observation from a vessel or 
aircraft immediately before and during the exercise within a mitigation 
zone of 200 yd. (180 m) around the intended impact location. Vessels 
will observe the mitigation zone from the firing position. When 
aircraft are firing, the aircrew will maintain visual watch of the 
mitigation zone during the activity. The exercise will not commence if 
concentrations of floating vegetation (kelp paddies) are observed in 
the mitigation zone. Firing will cease if a marine mammal is sighted 
within the mitigation zone. Firing will recommence if any one of the 
following conditions is met: (1) The animal is observed exiting the 
mitigation zone, (2) the animal is thought to have exited the 
mitigation zone based on its course and speed, (3) the mitigation zone 
has been clear from any additional sightings for a period of 10 minutes 
for a firing aircraft, (4) the mitigation zone has been clear from any 
additional sightings for a period of 30 minutes for a firing ship, or 
(5) the intended target location has been repositioned more than 400 
yd. (370 m) away from the location of the last sighting.
Testing
    The Navy's proposed action does not include gunnery testing 
activities.

Gunnery Exercises--Large-Caliber Explosive Rounds Using a Surface 
Target

Training
    There are currently no existing mitigation measures unique to 
large-caliber explosive gunnery exercises in the Study Area. The Navy 
is proposing to adopt mitigation measures in place at other Navy 
training ranges outside of the Study Area.
    For all explosive and non-explosive large-caliber gunnery exercises 
conducted from a ship, mitigation will include visual observation 
immediately before and during the exercise within a mitigation zone of 
70 yd. (46 m) within 30 degrees on either side of the gun target line 
on the firing side. The exercise will not commence if concentrations of 
floating vegetation (kelp paddies) are observed in the mitigation zone. 
Firing will cease if a marine mammal is sighted within the mitigation 
zone. Firing will recommence if any one of the following conditions is 
met: (1) The animal is observed exiting the mitigation zone, (2) the 
animal is thought to have exited the mitigation zone based on its 
course and speed, (3) the mitigation zone has been clear from any 
additional sightings for a period of 30 minutes, or (4) the vessel has 
repositioned itself more than 140 yd. (128 m) away from the location of 
the last sighting.
Testing
    The Navy is proposing to (1) implement new mitigation zone measures 
for this activity, (2) describe conditions needed to recommence an 
activity after a sighting, and (3) implement a requirement to visually 
observe for kelp paddies. The recommended measures are provided below.
    Mitigation will include visual observation from a ship immediately 
before and during the exercise within a mitigation zone of 600 yd. (550 
m) around the intended impact location. Ships will observe the 
mitigation zone from the firing position. The exercise will not 
commence if concentrations of floating vegetation (kelp paddies) are 
observed in the mitigation zone. Firing will cease if a marine mammal 
is sighted within the mitigation zone. Firing will recommence if any 
one of the following conditions is met: (1) The animal is observed 
exiting the mitigation zone, (2) the animal is thought to have exited 
the mitigation zone based on its course and speed, or (3) the 
mitigation zone has been clear from any additional sightings for a 
period of 30 minutes.

Missile Exercises up to 250 Pound Net Explosive Weight Using a Surface 
Target

Training
    Currently, the Navy employs a mitigation zone of 1,800 yd. (1.6 km) 
for all missile exercises. Because the Navy is not proposing to use 
missiles with less than a 251 lb. NEW warhead in the Study Area, 
separate mitigation procedures for this exercise have not been 
developed. Should the need arise to conduct training using missiles in 
this category, the Navy proposes that mitigation procedures be followed 
as described below for the larger category of missiles (Missile 
Exercises 251-500 Pound Net Explosive Weight [Surface Target]).
Testing
    The Navy's proposed action does not include missile testing 
activities.

Missile Exercises 251-500 Pound Net Explosive Weight (Surface Target)

Training
    Current mitigation measures apply to all missile exercises, 
regardless of the warhead size. The Navy proposes to add a mitigation 
zone that applies only to missiles with a NEW of 251-500 lb. The 
recommended measures are provided below.
    When aircraft are involved in the missile firing, mitigation will 
include visual observation by the aircrew prior to commencement of the 
activity within a mitigation zone of 2,000 yd. (1.8 km) around the 
intended impact location. The exercise will not commence if 
concentrations of floating vegetation (kelp paddies) are observed in 
the mitigation zone. Firing will cease if a marine mammal is sighted 
within the mitigation zone. Firing will recommence if any one of the 
following conditions is met: (1) The animal is observed exiting the 
mitigation zone, (2) the animal is thought to have exited the 
mitigation zone based on its course and speed, or (3) the mitigation 
zone has been clear from any additional sightings for a period of 10 
minutes or 30 minutes (depending on aircraft type).
Testing
    The Navy's proposed action does not include missile testing 
activities.

Bombing Exercises

Training
    Currently, the Navy employs the following mitigation zone 
procedures during bombing exercises:
     Ordnance shall not be targeted to impact within 1,000 yd. 
(920 m) of known or observed floating kelp or marine mammals.
     A 1,000 yd. (920 m) radius mitigation zone shall be 
established around the intended target.
     The exercise will be conducted only if marine mammals are 
not visible within the mitigation zone.
    The Navy is proposing to (1) maintain the existing mitigation zone 
to be used for non-explosive bombing activities, (2) revise the 
mitigation zone procedures to account for predicted ranges to impacts 
to marine species when high explosive bombs are used, (3) clarify the 
conditions needed to recommence an activity after a sighting, and (4) 
add a requirement to visually observe for kelp paddies.
    Mitigation will include visual observation from the aircraft

[[Page 31777]]

immediately before the exercise and during target approach within a 
mitigation zone of 2,500 yd. (2.3 km) around the intended impact 
location for explosive bombs and 1,000 yd. (920 m) for non-explosive 
bombs. The exercise will not commence if concentrations of floating 
vegetation (kelp paddies) are observed in the mitigation zone. Bombing 
will cease if a marine mammal is sighted within the mitigation zone. 
Bombing will recommence if any one of the following conditions is met: 
(1) The animal is observed exiting the mitigation zone, (2) the animal 
is thought to have exited the mitigation zone based on its course and 
speed, or (3) the mitigation zone has been clear from any additional 
sightings for a period of 10 minutes.
Testing
    The Navy's proposed action does not include bomb testing 
activities.

Torpedo (Explosive) Testing

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

Weapons Firing Noise During Gunnery Exercises--Large-Caliber

Training
    The Navy and U.S. Coast Guard are proposing to adopt measures 
currently used during Navy gunnery exercises in other ranges outside of 
the Study Area. For all explosive and non-explosive large-caliber 
gunnery exercises conducted from a ship, mitigation will include visual 
observation immediately before and during the exercise within a 
mitigation zone of 70 yd. (46 m) within 30 degrees on either side of 
the gun target line on the firing side. The exercise will not commence 
if concentrations of floating vegetation (kelp paddies) are observed in 
the mitigation zone. Firing will cease if a marine mammal is sighted 
within the mitigation zone. Firing will recommence if any one of the 
following conditions is met: (1) The animal is observed exiting the 
mitigation zone, (2) the animal is thought to have exited the 
mitigation zone based on its course and speed, (3) the mitigation zone 
has been clear from any additional sightings for a period of 30 
minutes, or (4) the vessel has repositioned itself more than 140 yd. 
(128 m) away from the location of the last sighting.
Testing
    The Navy's proposed action does not include gun testing activities.

Vessels

Training
    The Navy's current measures to mitigate potential impacts to marine 
mammals from vessel and in-water device strikes during training 
activities are provided below:
     Naval vessels shall maneuver to keep at least 500 yd. (460 
m) away from any observed whale in the vessel's path and avoid 
approaching whales head-on. These requirements do not apply if a 
vessel's safety is threatened, such as when change of course will 
create an imminent and serious threat to a person, vessel, or aircraft, 
and to the extent vessels are restricted in their ability to maneuver. 
Restricted maneuverability includes, but is not limited to, situations 
when vessels are engaged in dredging, submerged activities, launching 
and recovering aircraft or landing craft, minesweeping activities, 
replenishment while underway and towing activities that severely 
restrict a vessel's ability to deviate course.
     Vessels will take reasonable steps to alert other vessels 
in the vicinity of the whale. Given rapid swimming speeds and 
maneuverability of many dolphin species, naval vessels would maintain 
normal course and speed on sighting dolphins unless some condition 
indicated a need for the vessel to maneuver.
    The Navy is proposing to continue to use the 500 yd. (460 m) 
mitigation zone currently established for whales, and to implement a 
200 yd. (180 m) mitigation zone for all other marine mammals. Vessels 
will avoid approaching marine mammals head on and will maneuver to 
maintain a mitigation zone of 500 yd. (460 m) around observed whales 
and 200 yd. (180 m) around all other marine mammals (except bow-riding 
dolphins), providing it is safe to do so.
Testing
    The Navy's current measures to mitigate potential impacts to marine 
mammals from vessel and in-water device strikes during testing 
activities are provided below:
     Range activities shall be conducted in such a way as to 
ensure marine mammals are not harassed or harmed by human-caused 
events.
     Visual surveillance shall be accomplished just prior to 
all in-water exercises. This surveillance shall ensure that no marine 
mammals are visible within the boundaries of the area within which the 
test unit is expected to be operating. Surveillance shall include, as a 
minimum, monitoring from all participating surface craft and, where 
available, adjacent shore sites.
     The Navy shall postpone activities until cetaceans 
(whales, dolphins, and porpoises) leave the activity area. When 
cetaceans have been sighted in an area, all range participants increase 
vigilance and take reasonable and practicable actions to avoid 
collisions and activities that may result in close interaction of naval 
assets and marine mammals. Actions may include changing speed or

[[Page 31778]]

direction and are dictated by environmental and other conditions (e.g., 
safety, weather).
     Range craft shall not approach within 100 yd. (90 m) of 
marine mammals and shall be followed to the extent practicable 
considering human and vessel safety priorities. All Navy vessels and 
aircraft, including helicopters, are expected to comply with this 
directive. This includes marine mammals ``hauled-out'' on islands, 
rocks, and other areas such as buoys.
    The Navy is proposing to incorporate the training mitigation 
measures described above during testing activities involving surface 
ships, and for all other testing activities to continue using the 
mitigation measures currently implemented, revised to exclude pinnipeds 
during test body retrieval and to include the exception for bow-riding 
dolphins as described above under Training. During test body retrieval, 
the activity cannot be relocated away from marine mammals active in the 
area, or significantly delayed without risking loss of the test body, 
so the activity must proceed even if pinnipeds are present in the 
immediate vicinity. However, the retrieval vessel is a range craft and 
risks to marine mammals are very low.

Towed In-Water Devices

Training
    The Navy is proposing to adopt measures currently used in other 
ranges outside of the Study Area during activities involving towed in-
water devices. The Navy will ensure that towed in-water devices being 
towed from manned platforms avoid coming within a mitigation zone of 
250 yd. (230 m) around any observed marine mammal, providing it is safe 
to do so.
Testing
    The Navy's proposed mitigation measures for testing activities from 
manned platforms are consistent with Navy training mitigation measures 
described above. During testing in which in-water devices are towed by 
unmanned platforms, a manned escort vessel will be included and one 
Lookout will be employed.

Non-Explosive Gunnery Exercises--Small, Medium, and Large-Caliber Using 
a Surface Target

Training
    Currently, the Navy employs the same mitigation measures for non-
explosive gunnery exercises as described above for explosive Gunnery 
Exercises--Small-, Medium-, and Large-Caliber Using a Surface Target.
    The Navy is proposing to (1) continue using the mitigation measures 
currently implemented for this activity, and (2) clarify the conditions 
needed to recommence an activity after a sighting. The recommended 
measures are provided below.
    Mitigation will include visual observation from a vessel or 
aircraft immediately before and during the exercise within a mitigation 
zone of 200 yd. (180 m) around the intended impact location. The 
exercise will not commence if concentrations of floating vegetation 
(kelp paddies) are observed in the mitigation zone. Firing will cease 
if a marine mammal is sighted within the mitigation zone. Firing will 
recommence if any one of the following conditions is met: (1) The 
animal is observed exiting the mitigation zone, (2) the animal is 
thought to have exited the mitigation zone based on its course and 
speed, (3) the mitigation zone has been clear from any additional 
sightings for a period of 10 minutes for a firing aircraft, (4) the 
mitigation zone has been clear from any additional sightings for a 
period of 30 minutes for a firing ship, or (5) the intended target 
location has been repositioned more than 400 yd. (370 m) away from the 
location of the last sighting.
Testing
    The Navy's proposed action does not include gunnery testing 
activities.

Non-Explosive Bombing Exercises

Training
    The Navy is proposing to continue using the mitigation measures 
currently implemented for this activity. The recommended measure 
includes clarification of a post-sighting activity recommencement 
criterion.
    Mitigation will include visual observation from the aircraft 
immediately before the exercise and during target approach within a 
mitigation zone of 1,000 yd. (920 m) around the intended impact 
location. The exercise will not commence if concentrations of floating 
vegetation (kelp paddies) are observed in the mitigation zone. Bombing 
will cease if a marine mammal is sighted within the mitigation zone. 
Bombing will recommence if any one of the following conditions is met: 
(1) The animal is observed exiting the mitigation zone, (2) the animal 
is thought to have exited the mitigation zone based on its course and 
speed, or (3) the mitigation zone has been clear from any additional 
sightings for a period of 10 minutes.
Testing
    The Navy's proposed action does not include bomb testing 
activities.

Consideration of Time/Area Limitations

    Already incorporated into the Navy's and NMFS' analysis of affects 
to marine mammals, has been consideration of emergent science regarding 
locations where cetaceans are known to engage in specific activities 
(e.g., feeding, breeding/calving, or migration) at certain times of the 
year that are important to individual animals as well as populations of 
marine mammals (see discussion in Van Parijs, 2015). As explained in 
that paper, each such location has been designated a Biologically 
Important Area (BIA). It is important to note that the BIAs were not 
meant to define exclusionary zones, nor were they meant to be locations 
that serve as sanctuaries from human activity, or areas analogous to 
marine protected areas (see Ferguson et al. (2015a) regarding the 
envisioned purpose for the BIA designations). The delineation of BIAs 
does not have direct or immediate regulatory consequences. The 
intention was that the BIAs would serve as resource management tools 
and their boundaries be dynamic and considered along with any new 
information as well as, ``existing density estimates, range-wide 
distribution data, information on population trends and life history 
parameters, known threats to the population, and other relevant 
information'' (Van Parijs, 2015).
    The Navy and NMFS have supported and will continue to support the 
Cetacean and Sound Mapping project, including providing representation 
on the Cetacean Density and Distribution Mapping Working Group (CetMap) 
developing the BIAs. The final products, including U.S. West Coast 
BIAs, from this mapping effort were completed and published in March 
2015 (Aquatic Mammals, 2015; Calambokidis et al., 2015; Ferguson et 
al., 2015a, 2015b; Van Parijs, 2015). 131 BIAs for 24 marine mammal 
species, stocks, or populations in seven regions within U.S. waters 
were identified (Ferguson et al., 2015a). BIAs in the West Coast of the 
continental U.S. with the potential to overlap portions of the Study 
Area include the following feeding and migration areas: Northern Puget 
Sound Feeding Area for gray whales; Northbound Migration Phase A for 
gray whales; Northbound Migration Phase B for gray whales; Potential 
Presence Migration Area for gray whales; Northern Washington Feeding 
Area for humpback whales; Stonewall and Heceta Bank Feeding Area for

[[Page 31779]]

humpback whales; Cape Blanco and Orford Reef Feeding Area for gray 
whale; and Point St. George Feeding Area for gray whales (Calambokidis 
et al., 2015).
    NMFS Office of Protected Resources routinely considers available 
information about marine mammal habitat use to inform discussions with 
applicants regarding potential spatio-temporal limitations on their 
activities that might help effect the least practicable adverse impact 
on species or stocks and their habitat. BIAs are useful tools for 
planning and impact assessments and are being provided to the public 
via this Web site: www.cetsound.noaa.gov. While these BIAs are useful 
tools for analysts, any decisions regarding protective measures based 
on these areas must go through the normal MMPA evaluation process (or 
any other statutory process that the BIAs are used to inform)--the 
designation of a BIA does not pre-suppose any specific management 
decision associated with those areas, nor does it have direct or 
immediate regulatory consequences.
    During the April 2014 annual adaptive management meeting in 
Washington, DC, NMFS and the Navy discussed the BIAs that might overlap 
with portions of the NWTT Study Area, what Navy activities take place 
in these areas (in the context of what their effects on marine mammals 
might be or whether additional mitigation is necessary), and what 
measures could be implemented to reduce impacts in these areas (in the 
context of their potential to reduce marine mammal impacts and their 
practicability). Upon request by NMFS the Navy preparing a draft 
assessment of these BIAs, including the degree of spatial overlap as 
well as an assessment of potential impacts or lack of impacts for each 
BIA. The Navy preliminarily determined that the degree of overlap 
between Navy activities within the Study Area and regional BIAs is 
relatively small (10 percent) geographically. Further, a review of the 
BIAs for humpback whales and gray whales against areas where most 
acoustic activities are conducted in the Study Area (especially those 
that involve ASW hull-mounted sonar, sonobuoys, and use of explosive 
munitions) identified that there is no spatial overlap. The Navy 
preliminarily concluded that any potential impacts from training and 
testing activities on a given area are infrequent, spatially and 
temporally variable, and biologically insignificant since the 
activities are unlikely to significantly affect the marine mammal 
activities for which the BIAs were designated. The Navy also concluded 
that additional mitigations other than those already described in the 
January 2014 NWTT DEIS/OEIS and LOA application would not be further 
protective nor offer addition protection to marine mammals beyond what 
is already proposed. NMFS is currently reviewing the Navy's draft 
assessment, the outcome of which will be discussed in the final rule.
    As we learn more about marine mammal density, distribution, and 
habitat use (and the BIAs are updated), NMFS and the Navy will continue 
to reevaluate appropriate time-area measures through the Adaptive 
Management process outlined in these regulations.

Stranding Response Plan

    NMFS and the Navy developed a Stranding Response Plan for the NWTRC 
in 2010 and the NUWC Keyport Range Complex in 2011 as part of the 
incidental take authorization process for those complexes. The 
Stranding Response Plan is specifically intended to outline the 
applicable requirements in the event that a marine mammal stranding is 
reported in the complexes during a major training exercise. NMFS 
considers all plausible causes within the course of a stranding 
investigation and this plan in no way presumes that any strandings in a 
Navy range complex are related to, or caused by, Navy training and 
testing activities, absent a determination made during investigation. 
The plan is designed to address mitigation, monitoring, and compliance. 
The Navy is currently working with NMFS to refine this plan for the 
NWTT Study Area. The current Stranding Response Plans for the NWTRC and 
NUWC Keyport Range Complex are available for review here: http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm.

Mitigation Conclusions

    NMFS has carefully evaluated the Navy's proposed mitigation 
measures--many of which were developed with NMFS' input during the 
first phase of Navy Training and Testing authorizations--and considered 
a range of other measures in the context of ensuring that NMFS 
prescribes the means of effecting the least practicable adverse impact 
on the affected marine mammal species and stocks and their habitat. Our 
evaluation of potential measures included consideration of the 
following factors in relation to one another: The manner in which, and 
the degree to which, the successful implementation of the mitigation 
measures is expected to reduce the likelihood and/or magnitude of 
adverse impacts to marine mammal species and stocks and their habitat; 
the proven or likely efficacy of the measures; and the practicability 
of the suite of measures for applicant implementation, including 
consideration of personnel safety, practicality of implementation, and 
impact on the effectiveness of the military readiness activity.
    Any mitigation measure(s) prescribed by NMFS should be able to 
accomplish, have a reasonable likelihood of accomplishing (based on 
current science), or contribute to accomplishing one or more of the 
general goals listed below:
    a. Avoid or minimize injury or death of marine mammals wherever 
possible (goals b, c, and d may contribute to this goal).
    b. Reduce the number of marine mammals (total number or number at 
biologically important time or location) exposed to received levels of 
MFAS/HFAS, underwater detonations, or other activities expected to 
result in the take of marine mammals (this goal may contribute to a, 
above, or to reducing harassment takes only).
    c. Reduce the number of times (total number or number at 
biologically important time or location) individuals would be exposed 
to received levels of MFAS/HFAS, underwater detonations, or other 
activities expected to result in the take of marine mammals (this goal 
may contribute to a, above, or to reducing harassment takes only).
    d. Reduce the intensity of exposures (either total number or number 
at biologically important time or location) to received levels of MFAS/
HFAS, underwater detonations, or other activities expected to result in 
the take of marine mammals (this goal may contribute to a, above, or to 
reducing the severity of harassment takes only).
    e. Avoid or minimize adverse effects to marine mammal habitat, 
paying special attention to the food base, activities that block or 
limit passage to or from biologically important areas, permanent 
destruction of habitat, or temporary destruction/disturbance of habitat 
during a biologically important time.
    f. For monitoring directly related to mitigation--increase the 
probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation (shut-down zone, etc.).
    Based on our evaluation of the Navy's proposed measures, as well as 
other measures considered by NMFS, NMFS has determined preliminarily 
that the Navy's proposed mitigation measures (especially when the 
adaptive management component is taken into

[[Page 31780]]

consideration (see Adaptive Management, below)) are adequate means of 
effecting the least practicable adverse impacts on marine mammals 
species or stocks and their habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, while 
also considering personnel safety, practicality of implementation, and 
impact on the effectiveness of the military readiness activity.
    The proposed rule comment period provides the public an opportunity 
to submit recommendations, views, and/or concerns regarding this action 
and the proposed mitigation measures. While NMFS has determined 
preliminarily that the Navy's proposed mitigation measures would effect 
the least practicable adverse impact on the affected species or stocks 
and their habitat, NMFS will consider all public comments to help 
inform our final decision. Consequently, the proposed mitigation 
measures may be refined, modified, removed, or added to prior to the 
issuance of the final rule based on public comments received, and where 
appropriate, further analysis of any additional mitigation measures.

Monitoring

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

Integrated Comprehensive Monitoring Program (ICMP)

    The Navy's ICMP is intended to coordinate monitoring efforts across 
all regions and to allocate the most appropriate level and type of 
effort for each range complex based on a set of standardized 
objectives, and in acknowledgement of regional expertise and resource 
availability. The ICMP is designed to be flexible, scalable, and 
adaptable through the adaptive management and strategic planning 
processes to periodically assess progress and reevaluate objectives. 
Although the ICMP does not specify actual monitoring field work or 
projects, it does establish top-level goals that have been developed in 
coordination with NMFS. As the ICMP is implemented, detailed and 
specific studies will be developed which support the Navy's top-level 
monitoring goals. In essence, the ICMP directs that monitoring 
activities relating to the effects of Navy training and testing 
activities on marine species should be designed to contribute towards 
one or more of the following top-level goals:
     An increase in our understanding of the likely occurrence 
of marine mammals and/or ESA-listed marine species in the vicinity of 
the action (i.e., presence, abundance, distribution, and/or density of 
species);
     An increase in our understanding of the nature, scope, or 
context of the likely exposure of marine mammals and/or ESA-listed 
species to any of the potential stressor(s) associated with the action 
(e.g., tonal and impulsive sound), through better understanding of one 
or more of the following: (1) The action and the environment in which 
it occurs (e.g., sound source characterization, propagation, and 
ambient noise levels); (2) the affected species (e.g., life history or 
dive patterns); (3) the likely co-occurrence of marine mammals and/or 
ESA-listed marine species with the action (in whole or part) associated 
with specific adverse effects, and/or; (4) the likely biological or 
behavioral context of exposure to the stressor for the marine mammal 
and/or ESA-listed marine species (e.g., age class of exposed animals or 
known pupping, calving or feeding areas);
     An increase in our understanding of how individual marine 
mammals or ESA-listed marine species respond (behaviorally or 
physiologically) to the specific stressors associated with the action 
(in specific contexts, where possible, e.g., at what distance or 
received level);
     An increase in our understanding of how anticipated 
individual responses to individual stressors or anticipated 
combinations of stressors may impact either: (1) The long-term fitness 
and survival of an individual; or (2) the population, species, or stock 
(e.g., through effects on annual rates of recruitment or survival);
     An increase in our understanding of the effectiveness of 
mitigation and monitoring measures;
     A better understanding and record of the manner in which 
the authorized entity complies with the ITA and Incidental Take 
Statement;
     An increase in the probability of detecting marine mammals 
(through improved technology or methods), both specifically within the 
safety zone (thus allowing for more effective implementation of the 
mitigation) and in general, to better achieve the above goals; and
     A reduction in the adverse impact of activities to the 
least practicable level, as defined in the MMPA.
    Monitoring would address the ICMP top-level goals through a 
collection of specific regional and ocean basin studies based on 
scientific objectives. Quantitative metrics of monitoring effort (e.g., 
20 days of aerial surveys) would not be a specific requirement. The 
adaptive management process and reporting requirements would serve as 
the basis for evaluating performance and compliance, primarily 
considering the quality of the work and results produced, as well as 
peer review and publications, and public dissemination of information, 
reports, and data. Details of the ICMP are available online (http://www.navymarinespeciesmonitoring.us/).

Strategic Planning Process for Marine Species Monitoring

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

Past Monitoring in the NWTT Study Area

    NMFS has received multiple years' worth of annual exercise and 
monitoring reports addressing active sonar use and explosive 
detonations within the NWTT and other Navy range complexes. The data 
and information contained in these reports have been considered in 
developing mitigation and

[[Page 31781]]

monitoring measures for the proposed training and testing activities 
within the NWTT Study Area. The Navy's annual exercise and monitoring 
reports may be viewed at: http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm and http://www.navymarinespeciesmonitoring.us. 
NMFS has reviewed these reports and summarized the results, as related 
to marine mammal monitoring, below.
    1. The Navy has shown significant initiative in developing its 
marine species monitoring program and made considerable progress toward 
reaching goals and objectives of the ICMP.
    2. Observation data from watchstanders aboard navy vessels is 
generally useful to indicate the presence or absence of marine mammals 
within the mitigation zones (and sometimes beyond) and to document the 
implementation of mitigation measures, but does not provide useful 
species-specific information or behavioral data.
    3. Data gathered by experienced marine mammal observers can provide 
very valuable information at a level of detail not possible with 
watchstanders.
    4. Though it is by no means conclusive, it is worth noting that no 
instances of obvious behavioral disturbance have been observed by Navy 
watchstanders or experienced marine mammal observers conducting visual 
monitoring.
    5. Visual surveys generally provide suitable data for addressing 
questions of distribution and abundance of marine mammals, but are much 
less effective at providing information on movements and behavior, with 
a few notable exceptions where sightings are most frequent.
    6. Passive acoustics and animal tagging have significant potential 
for applications addressing animal movements and behavioral response to 
Navy training activities, but require a longer time horizon and heavy 
investment in analysis to produce relevant results.
    This following section includes a summary of Navy-funded compliance 
monitoring in the NWTRC since 2010 and in the NUWC Keyport Range 
Complex since 2011. Additional Navy-funded monitoring outside of and in 
addition to the Navy's commitments to NMFS is provided later in the 
section. The monitoring years are shown in Table 12.

                                Table 12--Navy Monitoring Years in the Study Area
----------------------------------------------------------------------------------------------------------------
  Navy monitoring years in the study
          area range complex                    Year 1                   Year 2                   Year 3
----------------------------------------------------------------------------------------------------------------
Northwest Training Range Complex.....  12 November 2010-01 May  02 May 2011-01 May 2012  02 May 2012-01 May
                                        2011.                                             2013.
Keyport Range Complex................  12 April 2011-08         09 November 2011-08      09 November 2012-08
                                        November 2011.           November 2012.           November 2013.
----------------------------------------------------------------------------------------------------------------

Northwest Training Range Complex

Passive Acoustic Monitoring
    As part of previous monitoring within the Pacific Northwest, the 
Navy funded deployment of two passive acoustic devices along the 
central coast of Washington State from 2011 to 2013. Results from this 
effort are summarized in the Navy's annual NWTRC monitoring reports for 
2011, 2012, and 2013 (U.S. Department of the Navy, 2011; 
[Scaron]irovi[cacute] et al., 2012a and 2012b in U.S. Department of the 
Navy, 2012a; Kerosky et al., 2013 in U.S. Department of the Navy, 
2013). Total passive acoustic data recorded over the 3 years totals 
over 17,417 hours and includes signals from four baleen whale species 
(blue whale, fin whale, gray whale, and humpback whale) and seven 
odontocetes (Risso's dolphin, Pacific white-sided dolphin, killer 
whale, sperm whale, Stejneger's beaked whale, Baird's beaked whale, and 
Cuvier's beaked whale) (Kerosky et al. 2013 in U.S. Department of the 
Navy, 2013). Kerosky et al. (2013) found that seasonal patterns of all 
four baleen whale species were similar within the monitoring sites in 
NWTRC, with most calls detected between winter and early spring. Of the 
odontocetes recorded, sperm whales were generally detected most 
consistently while other non-beaked odontocetes occurred more 
sporadically. Stejneger's beaked whales were the most consistently 
recorded beaked whale, with all their detections occurring between 
December and June. Previous research-funded results from these same 
locations from 2004 to 2010 is available in Oleson et al. (2009) and 
Oleson and Hildebrand (2012).
Satellite Tagging
    The Navy purchased 10 satellite tracking tags in Year 1, suitable 
for deployment by a suite of marine species within the offshore waters 
of the NWTRC. The tags used were the Andrews-style LIMPET (Low Impact 
Minimally Percutaneous External Transmitter), in either the location-
only Spot5 configuration or the location/dive data Mk10-A configuration 
(Wildlife Computers, Redmond, Washington) (Schorr et al., 2012). Tags 
were programmed to species-specific, transmission schedule-based 
surfacing behavior and transmission data from previous deployments. 
Tags transmit animal movement data via the Argos satellite system. The 
commercial Argos system consists of data acquisition and relay 
equipment attached to NOAA low-orbiting weather satellites and ground-
based receivers and data processing systems.
    The Navy purchased these satellite tracking tags as part of the 
NWTRC monitoring from 2010 to 2013. The tags were deployed 
opportunistically during field efforts associated with a 3-year 
collaborative field project addressing marine mammal distribution and 
habitat use off Oregon and Washington (Schorr et al., 2012). The 
species of interest were endangered cetaceans such as blue whales, fin 
whales, humpback whales, and sperm whales, but also included high-
priority cetaceans such as beaked whales, in the event they were 
encountered in favorable tagging conditions. Other species of interest 
for tagging included seasonal resident gray whales and transient or 
offshore killer whales.
    Annual results from this effort are summarized in the Navy's NWTRC 
Monitoring Reports for 2011, 2012, and 2013 (U.S. Department of the 
Navy, 2011a, 2012a, and 2013d) and collectively in Schorr et al. 
(2012). During this reporting period (2010-2013), a collective total of 
21 tags were deployed on four different species off the Washington 
coast (3 gray whales, 5 humpback whales, 11 fin whales, and 2 offshore 
killer whales). A total of approximately 348 days of animal movement 
data was obtained (Schorr et al., 2013; U.S. Department of the Navy, 
2013d). Transmissions confirmed that gray whales were not migrating; 
rather, they stayed very close to shore and in a very localized area 
consistent with feeding. Movement data for the tagged

[[Page 31782]]

humpback whales suggest individuals spent time both on and off the 
shelf edge, including some of the underwater canyons off northern 
Washington. Movements obtained from tagged fin whales suggest these 
whales are most commonly using waters associated with the outer shelf 
edge. Overall, 75 percent of the fin whale locations received were 
within the NWTRC. Three fin whales with transmission durations greater 
than 21 days remained in the NWTRC for the entire duration of tag 
transmission. According to Schorr et al. (2013), localized movements 
for periods of this duration suggest that at least some fin whales are 
not simply migrating through the area, but are utilizing habitat within 
the NWTRC for extended periods of time, even during seasons generally 
associated with migration and use of lower latitude breeding areas for 
other baleen whales. While in the NWTRC, tagged killer whales primarily 
spent their time on the continental shelf, or well offshore of the 
shelf edge.
    In 2012, the Navy funded a multi-year satellite tracking study of 
Pacific Coast Feeding Group gray whales (U.S. Department of the Navy, 
2013d). Tags were attached to 11 gray whales near Crescent City, 
California, in fall 2012 (Mate, 2013). Good track histories were 
received from nine of the 11 tags which confirmed an exclusive near 
shore (< 15 km) distribution and movement along the California, Oregon, 
and Washington coast. Additional tag deployments on gray whales have 
occurred since the Mate (2013) report. These will be described in the 
NWTRC Year 4 Annual Monitoring Report in 2014.
    Satellite tagging efforts are also funded for 2014-2018 along the 
U.S. west coast and include fin and blue whales. Longer term tags (up 
to 1 year) will allow for an assessment of animal occurrence, movement 
patterns, and residence time at areas within and outside of Navy at-sea 
ranges, including the NWTRC.

Explosive Ordnance/Underwater Detonation Monitoring

    The Navy has conducted two annual underwater detonation training 
events in the NWTRC at the Floral Point site in Hood Canal. In 2012, 
the event was monitored by marine mammal and seabird observers, and 
acoustic measurements were also recorded. The observers were positioned 
aboard small Navy craft that followed a closely spaced transect pattern 
in nearshore waters. In 2013, a similar monitoring effort occurred, but 
two beach observers were added to the monitoring team in order to 
provide a training opportunity. The beach observers are not required 
under the permits. The entire area to be monitored can be seen via the 
small craft vessels and as a result of the tightly spaced transect 
observation pattern. Pre-event and post-event surveys were also 
conducted. Harbor seals were the only marine mammal species seen either 
before or after the training event, and no marine mammals were in the 
exclusion zone during the detonations.

Keyport Range Complex

    Annual monitoring surveys were undertaken in 2011, 2012, and 2013 
in the DBRC portion of the Keyport Range Complex. These surveys 
included both visual and passive acoustic monitoring during concurrent 
mid-frequency active sonar and high-frequency active sonar tests. In 
addition to Navy Lookouts, Navy marine mammal observers were positioned 
aboard range vessels and at a high elevation observation point on land 
to monitor the events. A pre-event and post-event survey was also 
conducted. Species seen included harbor seals, California sea lions, 
and harbor porpoise. In total over all years, there were 262 sightings 
representing 420 individuals seen during the visual surveys, which may 
include repeat sightings of the same individuals. No marine mammals 
were detected using the bottom-moored passive acoustic monitoring array 
in any year. Discussion and results from these efforts are summarized 
in the Navy's Keyport Range Complex Annual Monitoring Reports for 2011, 
2012, and 2013 (U.S. Department of the Navy, 2012c, 2012d, and 2013e).

Other Regional Navy-Funded Monitoring Efforts

    Additional marine mammal studies are being funded or conducted by 
the Navy outside of and in addition to the Navy's commitments to NMFS 
for the NWTRC and the NUWC Keyport Range Complex. A variety of field 
survey methodologies are being utilized in order to better determine 
marine mammal presence, seasonality, abundance, distribution, habitat 
use, and density in these areas. The following studies either have been 
conducted or are underway during the 2010-2014 period:
     Naval Base Pinniped Haulout Surveys (2010-2014): 
Biologists located at NAVBASE Kitsap, Bangor, Bremerton, the Manchester 
Fuel Depot, and Naval Station Everett have been conducting year-round 
counts of sea lions hauled out on site-specific structures such as the 
floating security fences, submarines, or other opportunistic haulouts 
such as the large floating dock near Manchester. These counts are 
typically conducted weekly and involve identifying the sea lions to 
species and documenting branded animals. This information has shown 
seasonal use of the haulouts at each site, as well as trends in the 
number of animals by species using the haulouts at each site. In the 
case of Bangor, there are no haulout areas used by adult harbor seals, 
despite the adults being seen daily in the water, year-round. The only 
exception to this would be during pupping season when one wave screen 
(floating dock) is used temporarily by adult females to give birth. In 
late fall 2013, there were sightings of individual harbor seal pups 
using opportunistic manmade structures as temporary haulouts. These 
sightings include one harbor seal pup using a partially submerged 
ladder rung as a haulout and place to nurse; another pup resting on a 
floating oil boom; a third pup resting on a large piece of chain 
hanging in the water; a fourth pup managing to get aboard a submarine 
and haul out next to the California sea lions; and a fifth, older 
juvenile resting on the outer pontoon of the floating security fence. 
Harbor seals have not been seen hauled out at Bremerton or at the 
floating dock near Manchester. Harbor seals do haul out on the log 
rafts near Naval Station Everett.
     Marine Mammal Surveys in Hood Canal and Dabob Bay (2011-
2012): The Navy conducted an opportunistic marine mammal vessel-based 
line transect density survey in Hood Canal and Dabob Bay during 
September and October 2011 and again in October 2012. In Hood Canal, 
the surveys followed a double saw-tooth pattern to achieve uniform 
coverage of the entire NAVBASE Kitsap, Bangor waterfront. Transects 
generally covered the area from Hazel Point on the south end of the 
Toandos Peninsula to Thorndyke Bay. Surveys in the adjacent Dabob Bay 
followed a slightly different pattern and generally followed more 
closely to the shoreline while completing a circular route through the 
Bay. These surveys had a dual purpose of collecting marine mammal and 
marbled murrelet (bird species) data, and near-shore surveys tended to 
yield more marbled murrelet sightings. During surveys, the survey 
vessels traveled at a speed of approximately five knots when transiting 
along the transect lines. Two observers recorded sightings of marine 
mammals both in the water and hauled out. Marine mammal sightings data 
included species identification, Global Positioning System animal 
locations relative to vessel position, and detailed behavioral notes. 
Data from the line

[[Page 31783]]

transect surveys can be used to improve estimates of marine mammal 
density in Hood Canal and Dabob Bay.
     Aerial Surveys of Pinniped Haulout Sites in Pacific 
Northwest Inland Waters (2013-2014): Navy-funded aerial surveys of 
pinniped haulout sites in the inland waters of Washington State were 
initiated in March 2013 (Jeffries, 2013b) and continued until March 
2014 (1-year study design). The objectives of this effort were to 
provide estimates of seasonal abundance, identify seasonal distribution 
patterns, and collect data to determine seal and sea lion densities. 
Aerial surveys being conducted under this effort represent the first 
pinniped assessments to be done in the region over all four seasons, 
and will therefore provide much-needed information about seasonal 
variation of harbor seal, northern elephant seal, California sea lion, 
and Steller sea lion distribution and abundance in the inland waters of 
Washington. In addition, this effort will update the Atlas of Seal and 
Seal Lion Haulout Sites in Washington (inland waters region) (Jeffries 
et al., 2000). Finally, in a collaborative effort, the NMFS Northwest 
Region provided additional funding to support summer-only aerial 
surveys of the U.S. waters of the Strait of Juan de Fuca (Cape Flattery 
to Port Angeles), as well as the San Juan Islands. This collaborative 
approach between the Navy and NMFS will allow NMFS to update the SAR 
for the Pacific harbor seal (Washington Inland Waters stock). The 
current SAR is derived from population estimates from 1999, and 
abundance information from current surveys will provide NMFS with 
required data to revise this outdated stock assessment.
     Aerial Surveys of Marine Mammals in Pacific Northwest 
Inland Waters (2013-2014): Navy-funded aerial line-transect density 
surveys in the inland waters of Washington State were initiated in 
August 2013 (Smultea and Bacon, 2013). Surveys are planned to continue 
quarterly (every season) through 2014. These surveys were designed in 
cooperation with NMFS in order to estimate density and abundance of 
species with sufficient sightings, document distribution and habitat 
use, and describe behaviors seen. Smultea and Bacon (2013) reported a 
total of 779 sightings composed of an estimated 1,716 individual marine 
mammals representing four species: Harbor seal, harbor porpoise, 
California sea lion, and Risso's dolphins. Eighty-seven percent of 
sightings were of harbor seals, while harbor porpoise were the second-
most frequent sighting (9 percent), followed by California sea lions; a 
pair of Risso's dolphins were seen twice.
     Tagging and Behavioral Monitoring of Sea Lions in the 
Pacific Northwest in Proximity to Navy Facilities (2013-2015): In an 
Interagency Agreement between the Navy and the NMFS Alaska Fisheries 
Science Center, the Navy has funded a sea lion satellite tagging study 
beginning in 2013 through 2015. Tagging is anticipated to occur in 
early 2014 with monitoring and data analysis extending into 2015. There 
are significant scientific data gaps in identifying the location of 
local foraging areas and percentage of time hauled out for pinniped 
species near Puget Sound Navy facilities. Data collected from this 
project will directly tie into Navy's future Phase III marine mammal 
density modeling for training and testing activities at-sea, and within 
Puget Sound. In particular, integration of improved haulout percentages 
will lower over-predictive modeled takes which currently, due to lack 
of regional data, assume all pinniped species are always in-water for 
purposes of model assessment of takes. Numbers of animals observed 
hauled out can be corrected into a population estimate by applying an 
estimate of the proportion of satellite-tagged-animals that are hauled 
out at the time of the census. Satellite-linked dive recorders can be 
used to assess location of foraging activity and describe the diving 
behavior, as well as record when the animal is hauled out.

Proposed Monitoring for the NWTT Study Area

    Based on NMFS-Navy meetings in June and October 2011, future Navy 
compliance monitoring, including pending NWTT monitoring, will address 
ICMP top-level goals through a series of regional and ocean basin study 
questions with a prioritization and funding focus on species of 
interest as identified for each range complex. The ICMP will also 
address relative investments to different range complexes based on 
goals across all range complexes, and monitoring will leverage multiple 
techniques for data acquisition and analysis whenever possible.
    Within the NWTT area, the Navy's initial recommendation for species 
of interest includes blue whale, fin whale, humpback whale, Southern 
Resident killer whale (offshore portion of their annual movements), and 
beaked whales. Navy monitoring for NWTT under this LOA authorization 
and concurrently in other areas of the Pacific Ocean will therefore be 
structured to address region-specific species-specific study questions 
that will be outlined in the final NWTT Monitoring Project Table in 
consultation with NMFS.
    As an early start to NWTT monitoring, in July 2014 the Navy 
provided funding ($209,000) to NMFS' Northwest Fisheries Science Center 
to jointly participate in a new NWTT-specific study: Modeling the 
distribution of southern resident killer whales in the Pacific 
Northwest. The goal of this new study is to provide a more scientific 
understanding of endangered southern resident killer whale winter 
distribution off the Pacific Northwest coast. While the end project 
will work to develop a Bayesian space-state model for predicting the 
offshore winter occurrence, the project will actually consist of 
analysis of existing NMFS data (passive acoustic detections, satellite 
tag tracks) as well as new data collection from fall 2014 through 
spring 2015. Details of the study can be found at: http://www.navymarinespeciesmonitoring.us/regions/pacific/current-projects/. 
The eight main tasks the study supports include:
     Identification and classification of marine mammal 
detections from acoustic recorders.
     Acquisition and field deployment of satellite-linked 
transmitters (n=4) to track and determine southern resident killer 
whales movements.
     Deployment of autonomous underwater acoustic recorders in 
and adjacent to the coastal and shelf/slope waters of Washington State. 
Navy funding will allow 10 additional recorders to be purchased and 
deployed along with four NMFS recorders for a total of 14 deployed 
recorders.
     Estimation of the probability of Southern Resident killer 
whale detection on acoustic recorders.
     Development of the state-space occurrence models.
     Development of predicative maps of the seasonal annual 
occurrence of southern resident killer whales.
     Development a cost efficient strategy for the deployment 
of acoustic recorders in and adjacent to Pacific Northwest Navy ranges.
     Reporting.

Ongoing Navy Research

    The U.S. Navy is one of the world's leading organizations in 
assessing the effects of human activities the marine environment, 
including marine mammals. From 2004 through 2013, the Navy has funded 
over $240M specifically for marine mammal research. Navy scientists 
work cooperatively with other government researchers and scientists, 
universities, industry, and non-governmental conservation organizations 
in collecting, evaluating, and modeling information

[[Page 31784]]

on marine resources. They also develop approaches to ensure that these 
resources are minimally impacted by existing and future Navy 
operations. It is imperative that the Navy's Research and Development 
efforts related to marine mammals are conducted in an open, transparent 
manner with validated study needs and requirements. The goal of the 
Navy's R&D program is to enable collection and publication of 
scientifically valid research as well as development of techniques and 
tools for Navy, academic, and commercial use. Historically, R&D 
programs are funded and developed by the Navy's Chief of Naval 
Operations Energy and Environmental Readiness and Office of Naval 
Research (ONR), Code 322 Marine Mammals and Biological Oceanography 
Program. Primary focus of these programs since the 1990s is on 
understanding the effects of sound on marine mammals, including 
physiological, behavioral and ecological effects.
    ONR's current Marine Mammals and Biology Program thrusts include, 
but are not limited to: (1) Monitoring and detection research; (2) 
integrated ecosystem research including sensor and tag development; (3) 
effects of sound on marine life (such as hearing, behavioral response 
studies, physiology [diving and stress], and PCAD); and (4) models and 
databases for environmental compliance.
    To manage some of the Navy's marine mammal research programmatic 
elements, OPNAV N45 developed in 2011 a new Living Marine Resources 
(LMR) Research and Development Program (http://www.lmr.navy.mil/). The 
goal of the LMR Research and Development Program is to identify and 
fill knowledge gaps and to demonstrate, validate, and integrate new 
processes and technologies to minimize potential effects to marine 
mammals and other marine resources. Key elements of the LMR program 
include:
     Providing science-based information to support Navy 
environmental effects assessments for research, development, 
acquisition, testing, and evaluation as well as Fleet at-sea training, 
exercises, maintenance, and support activities.
     Improving knowledge of the status and trends of marine 
species of concern and the ecosystems of which they are a part.
     Developing the scientific basis for the criteria and 
thresholds to measure the effects of Navy-generated sound.
     Improving understanding of underwater sound and sound 
field characterization unique to assessing the biological consequences 
resulting from underwater sound (as opposed to tactical applications of 
underwater sound or propagation loss modeling for military 
communications or tactical applications).
     Developing technologies and methods to monitor and, where 
possible, mitigate biologically significant consequences to living 
marine resources resulting from naval activities, emphasizing those 
consequences that are most likely to be biologically significant.

Navy Research and Development

    Navy Funded--Both the LMR and ONR Research and Development (R&D) 
programs periodically fund projects within the NWTT Study Area. Some 
data and results from these R&D projects are summarized in the Navy's 
annual range complex monitoring reports, and available on NMFS' Web 
site (http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm) and 
the Fleet's new marine species monitoring Web site (http://www.navymarinespeciesmonitoring.us/regions/pacific/current-projects/). 
In addition, the Navy's Range Complex monitoring during training and 
testing activities is coordinated with the Research and Development 
monitoring in a given region to leverage research objectives, assets, 
and studies where possible under the ICMP.
    The integration between the Navy's new LMR research and development 
program and related range complex monitoring will continue and improve 
during the applicable period of the rulemaking with results presented 
in NWTT annual monitoring reports.
    Other National Department of Defense Funded Initiatives--Strategic 
Environmental Research and Development Program (SERDP) and 
Environmental Security Technology Certification Program (ESTCP) are the 
DoD's environmental research programs, harnessing the latest science 
and technology to improve environmental performance, reduce costs, and 
enhance and sustain mission capabilities. The Programs respond to 
environmental technology requirements that are common to all of the 
military Services, complementing the Services' research programs. SERDP 
and ESTCP promote partnerships and collaboration among academia, 
industry, the military Services, and other Federal agencies. They are 
independent programs managed from a joint office to coordinate the full 
spectrum of efforts, from basic and applied research to field 
demonstration and validation.

Adaptive Management

    The final regulations governing the take of marine mammals 
incidental to Navy training and testing activities in the NWTT Study 
Area would contain an adaptive management component carried over from 
previous authorizations. Although better than 5 years ago, our 
understanding of the effects of Navy training and testing activities 
(e.g., MFAS/HFAS, underwater detonations) on marine mammals is still 
relatively limited, and yet the science in this field is evolving 
fairly quickly. These circumstances make the inclusion of an adaptive 
management component both valuable and necessary within the context of 
5-year regulations for activities that have been associated with marine 
mammal mortality in certain circumstances and locations.
    The reporting requirements associated with this proposed rule are 
designed to provide NMFS with monitoring data from the previous year to 
allow NMFS to consider whether any changes are appropriate. NMFS and 
the Navy would meet to discuss the monitoring reports, Navy R&D 
developments, and current science and whether mitigation or monitoring 
modifications are appropriate. The use of adaptive management allows 
NMFS to consider new information from different sources to determine 
(with input from the Navy regarding practicability) on an annual or 
biennial basis if mitigation or monitoring measures should be modified 
(including additions or deletions). Mitigation measures could be 
modified if new data suggests that such modifications would have a 
reasonable likelihood of reducing adverse effects to marine mammals and 
if the measures are practicable.
    The following are some of the possible sources of applicable data 
to be considered through the adaptive management process: (1) Results 
from monitoring and exercises reports, as required by MMPA 
authorizations; (2) compiled results of Navy funded R&D studies; (3) 
results from specific stranding investigations; (4) results from 
general marine mammal and sound research; and (5) any information which 
reveals that marine mammals may have been taken in a manner, extent, or 
number not authorized by these regulations or subsequent LOAs.

Proposed Reporting

    In order to issue an ITA for an activity, section 101(a)(5)(A) of 
the MMPA states that NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such

[[Page 31785]]

taking.'' Effective reporting is critical both to compliance as well as 
ensuring that the most value is obtained from the required monitoring. 
Some of the reporting requirements are still in development and the 
final rulemaking may contain additional details not contained here. 
Additionally, proposed reporting requirements may be modified, removed, 
or added based on information or comments received during the public 
comment period. Reports from individual monitoring events, results of 
analyses, publications, and periodic progress reports for specific 
monitoring projects would be posted to the Navy's Marine Species 
Monitoring web portal: http://www.navymarinespeciesmonitoring.us. 
Currently, there are several different reporting requirements pursuant 
to these proposed regulations:

General Notification of Injured or Dead Marine Mammals

    Navy personnel would ensure that NMFS (the appropriate Regional 
Stranding Coordinator) is notified immediately (or as soon as clearance 
procedures allow) if an injured or dead marine mammal is found during 
or shortly after, and in the vicinity of, any Navy training exercise 
utilizing MFAS, HFAS, or underwater explosive detonations. The Navy 
would provide NMFS with species identification or a description of the 
animal(s), the condition of the animal(s) (including carcass condition 
if the animal is dead), location, time of first discovery, observed 
behaviors (if alive), and photographs or video (if available).
    In the event that an injured, stranded, or dead marine mammal is 
found by the Navy that is not in the vicinity of, or during or shortly 
after MFAS, HFAS, or underwater explosive detonations, the Navy will 
report the same information as listed above as soon as operationally 
feasible and clearance procedures allow.

Annual Monitoring Plan Reports

    The Navy shall submit an annual report of the NWTT Monitoring Plan 
describing the implementation and results of the NWTT Monitoring Plan 
from the previous calendar year. Data collection methods will be 
standardized across range complexes and study areas to allow for 
comparison in different geographic locations. Although additional 
information will be gathered, the protected species observers 
collecting marine mammal data pursuant to the NWTT Monitoring Plan 
shall, at a minimum, provide the same marine mammal observation data 
required in Sec.  218.145. The report shall be submitted either 90 days 
after the calendar year, or 90 days after the conclusion of the 
monitoring year to be determined by the Adaptive Management process.
    The NWTT Monitoring Plan Report may be provided to NMFS within a 
larger report that includes the required Monitoring Plan reports from 
multiple range complexes and study areas (the multi-Range Complex 
Annual Monitoring Report). Such a report would describe progress of 
knowledge made with respect to monitoring plan study questions across 
all Navy ranges associated with the ICMP. Similar study questions shall 
be treated together so that progress on each topic shall be summarized 
across all Navy ranges. The report need not include analyses and 
content that does not provide direct assessment of cumulative progress 
on the monitoring plan study questions.

Annual Exercise and Testing Reports

    The Navy shall submit preliminary reports detailing the status of 
authorized sound sources within 21 days after the anniversary of the 
date of issuance of the LOA. The Navy shall submit detailed reports 3 
months after the anniversary of the date of issuance of the LOA. The 
detailed annual reports shall describe the level of training and 
testing conducted during the reporting period, and a summary of sound 
sources used (total annual hours or quantity [per the LOA] of each bin 
of sonar or other non-impulsive source; total annual number of each 
type of explosive exercises; total annual expended/detonated rounds 
[missiles, bombs, etc.] for each explosive bin; and improved Extended 
Echo-Ranging System (IEER)/sonobuoy summary, including total number of 
IEER events conducted in the Study Area, total expended/detonated 
rounds (buoys), and total number of self-scuttled IEER rounds. The 
analysis in the detailed reports will be based on the accumulation of 
data from the current year's report and data collected from previous 
reports.

5-Year Close-Out Exercise and Testing Report

    This report will be included as part of the 2020 annual exercise or 
testing report. This report will provide the annual totals for each 
sound source bin with a comparison to the annual allowance and the 5-
year total for each sound source bin with a comparison to the 5-year 
allowance. Additionally, if there were any changes to the sound source 
allowance, this report will include a discussion of why the change was 
made and include the analysis to support how the change did or did not 
result in a change in the SEIS and final rule determinations. The 
report will be submitted 3 months after the expiration of the rule. 
NMFS will submit comments on the draft close-out report, if any, within 
3 months of receipt. The report will be considered final after the Navy 
has addressed NMFS' comments, or 3 months after the submittal of the 
draft if NMFS does not provide comments.

Estimated Take of Marine Mammals

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

Definition of Harassment

    As mentioned previously, with respect to military readiness 
activities, section 3(18)(B) of the MMPA defines ``harassment'' as: 
``(i) any act that injures or has the significant potential to injure a 
marine mammal or marine mammal stock in the wild [Level A

[[Page 31786]]

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].'' It is important to note that, as Level 
B harassment is interpreted here and quantified by the behavioral 
thresholds described below, the fact that a single behavioral pattern 
(of unspecified duration) is abandoned or significantly altered and 
classified as a Level B take does not mean, necessarily, that the 
fitness of the harassed individual is affected either at all or 
significantly, or that, for example, a preferred habitat area is 
abandoned. Further analysis of context and duration of likely exposures 
and effects is necessary to determine the impacts of the estimated 
effects on individuals and how those may translate to population level 
impacts, and is included in the Analysis and Negligible Impact 
Determination.

Level B Harassment

    Of the potential effects that were described earlier in this 
document, the following are the types of effects that fall into the 
Level B harassment category:
    Behavioral Harassment--Behavioral disturbance that rises to the 
level described in the definition above, when resulting from exposures 
to non-impulsive or impulsive sound, is considered Level B harassment. 
Some of the lower level physiological stress responses discussed 
earlier would also likely co-occur with the predicted harassments, 
although these responses are more difficult to detect and fewer data 
exist relating these responses to specific received levels of sound. 
When Level B harassment is predicted based on estimated behavioral 
responses, those takes may have a stress-related physiological 
component as well.
    As the statutory definition is currently applied, a wide range of 
behavioral reactions may qualify as Level B harassment under the MMPA, 
including but not limited to avoidance of the sound source, temporary 
changes in vocalizations or dive patters, temporary avoidance of an 
area, or temporary disruption of feeding, migrating, or reproductive 
behaviors. The estimates calculated by the Navy using the acoustic 
thresholds do not differentiate between the different types of 
potential behavioral reactions. Nor do the estimates provide 
information regarding the potential fitness or other biological 
consequences of the reactions on the affected individuals. We therefore 
consider the available scientific evidence to determine the likely 
nature of the modeled behavioral responses and the potential fitness 
consequences for affected individuals
    Temporary Threshold Shift (TTS)--As discussed previously, TTS can 
affect how an animal behaves in response to the environment, including 
conspecifics, predators, and prey. The following physiological 
mechanisms are thought to play a role in inducing auditory fatigue: 
Effects to sensory hair cells in the inner ear that reduce their 
sensitivity, modification of the chemical environment within the 
sensory cells; residual muscular activity in the middle ear, 
displacement of certain inner ear membranes; increased blood flow; and 
post-stimulatory reduction in both efferent and sensory neural output. 
Ward (1997) suggested that when these effects result in TTS rather than 
PTS, they are within the normal bounds of physiological variability and 
tolerance and do not represent a physical injury. Additionally, 
Southall et al. (2007) indicate that although PTS is a tissue injury, 
TTS is not because the reduced hearing sensitivity following exposure 
to intense sound results primarily from fatigue, not loss, of cochlear 
hair cells and supporting structures and is reversible. Accordingly, 
NMFS classifies TTS (when resulting from exposure to sonar and other 
active acoustic sources and explosives and other impulsive sources) as 
Level B harassment, not Level A harassment (injury).

Level A Harassment

    Of the potential effects that were described earlier, following are 
the types of effects that can fall into the Level A harassment category 
(unless they further rise to the level of serious injury or mortality):
    Permanent Threshold Shift (PTS)--PTS (resulting either from 
exposure to MFAS/HFAS or explosive detonations) is irreversible and 
considered an injury. PTS results from exposure to intense sounds that 
cause a permanent loss of inner or outer cochlear hair cells or exceed 
the elastic limits of certain tissues and membranes in the middle and 
inner ears and result in changes in the chemical composition of the 
inner ear fluids.
    Tissue Damage due to Acoustically Mediated Bubble Growth--A few 
theories suggest ways in which gas bubbles become enlarged through 
exposure to intense sounds (MFAS/HFAS) to the point where tissue damage 
results. In rectified diffusion, exposure to a sound field would cause 
bubbles to increase in size. A short duration of sonar pings (such as 
that which an animal exposed to MFAS would be most likely to encounter) 
would not likely be long enough to drive bubble growth to any 
substantial size. Alternately, bubbles could be destabilized by high-
level sound exposures such that bubble growth then occurs through 
static diffusion of gas out of the tissues. The degree of 
supersaturation and exposure levels observed to cause microbubble 
destabilization are unlikely to occur, either alone or in concert 
because of how close an animal would need to be to the sound source to 
be exposed to high enough levels, especially considering the likely 
avoidance of the sound source and the required mitigation. Still, 
possible tissue damage from either of these processes would be 
considered an injury.
    Tissue Damage due to Behaviorally Mediated Bubble Growth--Several 
authors suggest mechanisms in which marine mammals could behaviorally 
respond to exposure to MFAS/HFAS by altering their dive patterns 
(unusually rapid ascent, unusually long series of surface dives, etc.) 
in a manner that might result in unusual bubble formation or growth 
ultimately resulting in tissue damage. In this scenario, the rate of 
ascent would need to be sufficiently rapid to compromise behavioral or 
physiological protections against nitrogen bubble formation.
    There is considerable disagreement among scientists as to the 
likelihood of this phenomenon (Piantadosi and Thalmann, 2004; Evans and 
Miller, 2003). Although it has been argued that traumas from recent 
beaked whale strandings are consistent with gas emboli and bubble-
induced tissue separations (Jepson et al., 2003; Fernandez et al., 
2005; Fern[aacute]ndez et al., 2012), nitrogen bubble formation as the 
cause of the traumas has not been verified. If tissue damage does occur 
by this phenomenon, it would be considered an injury. Recent modeling 
by Kvadsheim et al. (2012) determined that while behavioral and 
physiological responses to sonar have the potential to result in bubble 
formation, the actual observed behavioral responses of cetaceans to 
sonar did not imply any significantly increased risk over what may 
otherwise occur normally in individual marine mammals.
    Physical Disruption of Tissues Resulting from Explosive Shock 
Wave--Physical damage of tissues resulting from a shock wave (from an 
explosive detonation) is classified as an injury. Blast effects are 
greatest at the gas-liquid interface (Landsberg, 2000) and gas-
containing organs, particularly the lungs

[[Page 31787]]

and gastrointestinal tract, are especially susceptible (Goertner, 1982; 
Hill, 1978; Yelverton et al., 1973). Nasal sacs, larynx, pharynx, 
trachea, and lungs may be damaged by compression/expansion caused by 
the oscillations of the blast gas bubble (Reidenberg and Laitman, 
2003). Severe damage (from the shock wave) to the ears can include 
tympanic membrane rupture, fracture of the ossicles, damage to the 
cochlea, hemorrhage, and cerebrospinal fluid leakage into the middle 
ear.
    Vessel or Ordnance Strike--Vessel strike or ordnance strike 
associated with the specified activities would be considered Level A 
harassment, serious injury, or mortality. Vessel or ordnance strike is 
not anticipated with the Navy activities in the Study Area.

Take Thresholds

    For the purposes of an MMPA authorization, three types of take are 
identified: Level B harassment; Level A harassment; and mortality (or 
serious injury leading to mortality). The categories of marine mammal 
responses (physiological and behavioral) that fall into the two 
harassment categories were described in the previous section.
    Because the physiological and behavioral responses of the majority 
of the marine mammals exposed to non-impulse and impulse sounds cannot 
be easily detected or measured, and because NMFS must authorize take 
prior to the impacts to marine mammals, a method is needed to estimate 
the number of individuals that will be taken, pursuant to the MMPA, 
based on the proposed action. To this end, NMFS developed acoustic 
thresholds that estimate at what received level (when exposed to non-
impulse or impulse sounds) Level B harassment and Level A harassment of 
marine mammals would occur. The acoustic thresholds for non-impulse and 
impulse sounds are discussed below.
    Level B Harassment Threshold (TTS)--Behavioral disturbance, 
acoustic masking, and TTS are all considered Level B harassment. Marine 
mammals would usually be behaviorally disturbed at lower received 
levels than those at which they would likely sustain TTS, so the levels 
at which behavioral disturbance are likely to occur is considered the 
onset of Level B harassment. The behavioral responses of marine mammals 
to sound are variable, context specific, and, therefore, difficult to 
quantify (see Risk Function section, below).
    TTS is a physiological effect that has been studied and quantified 
in laboratory conditions. Because data exist to support an estimate of 
the received levels at which marine mammals will incur TTS, NMFS uses 
an acoustic criteria to estimate the number of marine mammals that 
might sustain TTS. TTS is a subset of Level B harassment (along with 
sub-TTS behavioral harassment) and the Navy is not specifically 
required to estimate those numbers; however, the more specifically the 
affected marine mammal responses can be estimated, the better the 
analysis.
    Level A Harassment Threshold (PTS)--For acoustic effects, because 
the tissues of the ear appear to be the most susceptible to the 
physiological effects of sound, and because threshold shifts tend to 
occur at lower exposures than other more serious auditory effects, NMFS 
has determined that PTS is the best indicator for the smallest degree 
of injury that can be measured. Therefore, the acoustic exposure 
associated with onset-PTS is used to define the lower limit of Level A 
harassment.
    PTS data do not currently exist for marine mammals and are unlikely 
to be obtained due to ethical concerns. However, PTS levels for these 
animals may be estimated using TTS data from marine mammals and 
relationships between TTS and PTS that have been determined through 
study of terrestrial mammals.
    We note here that behaviorally mediated injuries (such as those 
that have been hypothesized as the cause of some beaked whale 
strandings) could potentially occur in response to received levels 
lower than those believed to directly result in tissue damage. As 
mentioned previously, data to support a quantitative estimate of these 
potential effects (for which the exact mechanism is not known and in 
which factors other than received level may play a significant role) do 
not exist. However, based on the number of years (more than 60) and 
number of hours of MFAS per year that the U.S. (and other countries) 
has operated compared to the reported (and verified) cases of 
associated marine mammal strandings, NMFS believes that the probability 
of these types of injuries is very low. Tables 13 and 14 provide a 
summary of non-impulsive and impulsive thresholds to TTS and PTS for 
marine mammals. A detailed explanation of how these thresholds were 
derived is provided in the NWTT DEIS/OEIS Criteria and Thresholds 
Technical Report (Finneran and Jenkins, 2012) and summarized in Chapter 
6 of the LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm).

                          Table 13--Onset TTS and PTS Thresholds for Non-Impulse Sound
----------------------------------------------------------------------------------------------------------------
                Group                          Species                 Onset TTS                Onset PTS
----------------------------------------------------------------------------------------------------------------
Low-Frequency Cetaceans..............  All mysticetes.........  178 dB re 1[mu]Pa2-      198 dB re 1[mu]Pa2-
                                                                 sec(LFII).               sec(LFII)
Mid-Frequency Cetaceans..............  Most delphinids, beaked  178 dB re 1[mu]Pa2-      198 dB re 1[mu]Pa2-
                                        whales, medium and       sec(MFII).               sec(MFII)
                                        large toothed whales.
High-Frequency Cetaceans.............  Porpoises, Kogia spp...  152 dB re 1[mu]Pa2-      172 dB re 1[mu]Pa2-
                                                                 sec(HFII).              secSEL (HFII)
Phocidae In-water....................  Harbor, Hawaiian monk,   183 dB re 1[mu]Pa2-      197 dB re 1[mu]Pa2-
                                        elephant seals.          sec(PWI).                sec(PWI)
Otariidae & Obodenidae In-water......  Sea lions and fur seals  206 dB re 1[mu]Pa2-      220 dB re 1[mu]Pa2-
Mustelidae In-water..................  Sea otters.............   sec(OWI).                sec(OWI)
----------------------------------------------------------------------------------------------------------------
LFII, MFII, HFII: New compound Type II weighting functions; PWI, OWI: Original Type I (Southall et al., 2007)
  for pinniped and mustelid in water.


[[Page 31788]]

[GRAPHIC] [TIFF OMITTED] TP03JN15.018

Level B Harassment Risk Function (Behavioral Harassment)

    As the statutory definition is currently applied, a wide range of 
behavioral reactions may qualify as Level B harassment under the MMPA, 
including but not limited to avoidance of the sound source, temporary 
changes in vocalizations or dive patters, temporary avoidance of an 
area, or temporary disruption of feeding, migrating, or reproductive 
behaviors. The estimates calculated by the Navy using the acoustic 
thresholds do not differentiate between the different types of 
potential behavioral reactions. Nor do the estimates provide 
information regarding the potential fitness or other biological 
consequences of the reactions on the affected individuals. We therefore 
consider the available scientific evidence to determine the likely 
nature of the modeled behavioral responses and the potential fitness 
consequences for affected individuals.
    Behavioral Response Criteria for Non-Impulsive Sound from Sonar and 
other

[[Page 31789]]

Active Sources--In 2006, NMFS issued the first MMPA authorization to 
allow the take of marine mammals incidental to MFAS (to the Navy for 
RIMPAC). For that authorization, NMFS used 173 dB SEL as the criterion 
for the onset of behavioral harassment (Level B harassment). This type 
of single number criterion is referred to as a step function, in which 
(in this example) all animals estimated to be exposed to received 
levels above 173 db SEL would be predicted to be taken by Level B 
harassment and all animals exposed to less than 173 dB SEL would not be 
taken by Level B harassment. As mentioned previously, marine mammal 
behavioral responses to sound are highly variable and context specific 
(affected by differences in acoustic conditions; differences between 
species and populations; differences in gender, age, reproductive 
status, or social behavior; or the prior experience of the 
individuals), which means that there is support for alternate 
approaches for estimating behavioral harassment.
    Unlike step functions, acoustic risk continuum functions (which are 
also called ``exposure-response functions'' or ``dose-response 
functions'' in other risk assessment contexts) allow for probability of 
a response that NMFS would classify as harassment to occur over a range 
of possible received levels (instead of one number) and assume that the 
probability of a response depends first on the ``dose'' (in this case, 
the received level of sound) and that the probability of a response 
increases as the ``dose'' increases. In January 2009, NMFS issued three 
final rules governing the incidental take of marine mammals (within 
Navy's Hawaii Range, Southern California Training and Testing Range, 
and Atlantic Fleet Active Sonar Training complexes) that used a risk 
continuum to estimate the percent of marine mammals exposed to various 
levels of MFAS that would respond in a manner NMFS considers 
harassment.
    The Navy and NMFS have previously used acoustic risk functions to 
estimate the probable responses of marine mammals to acoustic exposures 
for other training and research programs. Examples of previous 
application include the Navy EISs on the Surveillance Towed Array 
Sensor System Low Frequency Active (SURTASS LFA) sonar (U.S. Department 
of the Navy, 2001c); the North Pacific Acoustic Laboratory experiments 
conducted off the Island of Kauai (Office of Naval Research, 2001), and 
the Supplemental EIS for SURTASS LFA sonar (U.S. Department of the 
Navy, 2007d). As discussed earlier, factors other than received level 
(such as distance from or bearing to the sound source, context of 
animal at time of exposure) can affect the way that marine mammals 
respond; however, data to support a quantitative analysis of those (and 
other factors) do not currently exist. It is also worth specifically 
noting that while context is very important in marine mammal response, 
given otherwise equivalent context, the severity of a marine mammal 
behavioral response is also expected to increase with received level 
(Houser and Moore, 2014). NMFS will continue to modify these criteria 
as new data become available and can be appropriately and effectively 
incorporated.
    The particular acoustic risk functions developed by NMFS and the 
Navy (see Figures 1 and 2 of the LOA application) estimate the 
probability of behavioral responses to MFAS/HFAS (interpreted as the 
percentage of the exposed population) that NMFS would classify as 
harassment for the purposes of the MMPA given exposure to specific 
received levels of MFAS/HFAS. The mathematical function (below) 
underlying this curve is a cumulative probability distribution adapted 
from a solution in Feller (1968) and was also used in predicting risk 
for the Navy's SURTASS LFA MMPA authorization as well.
[GRAPHIC] [TIFF OMITTED] TP03JN15.019


Where: R = Risk (0 - 1.0)

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

    Detailed information on the above equation and its parameters is 
available in the January 2014 NWTT DEIS/OEIS and previous Navy 
documents listed above.
    The harbor porpoise and beaked whales have unique criteria based on 
specific data that show these animals to be especially sensitive to 
sound. Harbor porpoise and beaked whale non-impulsive behavioral 
criteria are used unweighted--without weighting the received level 
before comparing it to the threshold (see Finneran and Jenkins, 2012).
    It has been speculated for some time that beaked whales might have 
unusual sensitivities to sonar sound due to their likelihood of 
stranding in conjunction with mid-frequency sonar use, even in areas 
where other species were more abundant (D'Amico et al., 2009), but 
there were not sufficient data to support a separate treatment for 
beaked whales until recently. With the recent publication of results 
from Blainville's beaked whale monitoring and experimental exposure 
studies on the instrumented AUTEC range in the Bahamas (McCarthy et al. 
2011; Tyack et al. 2011), there are now statistically strong data 
suggesting that beaked whales tend to avoid actual naval mid-frequency 
sonar in real anti-submarine training scenarios as well as playbacks of 
killer whale vocalizations, and other anthropogenic sounds. Tyack et 
al. (2011) report that, in reaction to sonar playbacks, most beaked 
whales stopped echolocating, made long slow ascent, and moved away from 
the sound. During an exercise using mid-frequency sonar, beaked whales 
avoided the sonar acoustic footprint at a distance where the received 
level was ``around 140 dB'' (SPL) and once the exercise ended, beaked 
whales re-inhabited the center of exercise area within 2-3 days (Tyack 
et al., 2011). The Navy has therefore adopted an unweighted 140 dB re 1 
[mu]Pa SPL threshold for significant behavioral effects for all beaked 
whales (family: Ziphiidae).
    Since the development of the criterion, analysis of the data the 
2010 and 2011 field seasons of the southern California Behavioral 
Responses Study have been published. The study, DeRuiter et al. 
(2013b), provides similar evidence of Cuvier's beaked whale 
sensitivities to sound based on two controlled exposures. Two whales, 
one in each season, were tagged and exposed to simulated mid-frequency 
active sonar at distances of 3.4-9.5 km. The 2011 whale was also 
incidentally exposed to mid-frequency active sonar from a distant naval 
exercise (approximately 118 km away). Received levels from the mid-
frequency active sonar signals during the controlled and incidental 
exposures were calculated as 84-144 and 78-106 dB re 1 [mu]Pa rms, 
respectively. Both whales showed responses to the controlled exposures, 
ranging from initial orientation changes to avoidance responses 
characterized by energetic fluking and swimming away from the source. 
However, the authors did not detect similar responses to incidental 
exposure to distant naval sonar exercises at comparable received 
levels, indicating that context of the exposures (e.g., source 
proximity, controlled source ramp-up) may have been a significant 
factor. Because the

[[Page 31790]]

sample size was limited (controlled exposures during a single dive in 
both 2010 and 2011) and baseline behavioral data was obtained from 
different stocks and geographic areas (i.e., Hawaii and Mediterranean 
Sea), and the responses exhibited to controlled exposures were not 
exhibited by an animal exposed to some of the same received levels of 
real sonar exercises, the Navy relied on the studies at the AUTEC that 
analyzed beaked whale responses to actual naval exercises using mid-
frequency active sonar to evaluate potential behavioral responses by 
beaked whales to proposed training and testing activities using sonar 
and other active acoustic sources.
    The information currently available regarding harbor porpoises 
suggests a very low threshold level of response for both captive and 
wild animals. Threshold levels at which both captive (Kastelein et al., 
2000; Kastelein et al., 2005; Kastelein et al., 2006; Kastelein et al., 
2008) and wild harbor porpoises (Johnston, 2002) responded to sound 
(e.g., acoustic harassment devices, acoustic deterrent devices, or 
other non-impulsive sound sources) are very low (e.g., approximately 
120 dB re 1 [mu]Pa). Therefore, a SPL of 120 dB re 1 [mu]Pa is used in 
this analysis as a threshold for predicting behavioral responses in 
harbor porpoises instead of the risk functions used for other species 
(i.e., we assume for the purpose of estimating take that all harbor 
porpoises exposed to 120 dB or higher MFAS/HFAS will be taken by Level 
B behavioral harassment).
    Behavioral Response Criteria for Impulsive Sound from Explosions--
If more than one explosive event occurs within any given 24-hour period 
within a training or testing event, behavioral criteria are applied to 
predict the number of animals that may be taken by Level B harassment. 
For multiple explosive events the behavioral threshold used in this 
analysis is 5 dB less than the TTS onset threshold (in sound exposure 
level). This value is derived from observed onsets of behavioral 
response by test subjects (bottlenose dolphins) during non-impulse TTS 
testing (Schlundt et al. 2000). Some multiple explosive events, such as 
certain naval gunnery exercises, may be treated as a single impulsive 
event because a few explosions occur closely spaced within a very short 
period of time (a few seconds). For single impulses at received sound 
levels below hearing loss thresholds, the most likely behavioral 
response is a brief alerting or orienting response. Since no further 
sounds follow the initial brief impulses, Level B take in the form of 
behavioral harassment beyond that associated with potential TTS would 
not be expected to occur. This reasoning was applied to previous shock 
trials (63 FR 230; 66 FR 87; 73 FR 143) and is extended to these Phase 
II criteria. Behavioral thresholds for impulsive sources are summarized 
in Table 15 and further detailed in the LOA application.
    Since impulse events can be quite short, it may be possible to 
accumulate multiple received impulses at sound pressure levels 
considerably above the energy-based criterion and still not be 
considered a behavioral take. The Navy treats all individual received 
impulses as if they were one second long for the purposes of 
calculating cumulative sound exposure level for multiple impulse 
events. For example, five air gun impulses, each 0.1 second long, 
received at a Type II weighted sound pressure level of 167 dB SPL would 
equal a 164 dB sound exposure level, and would not be predicted as 
leading to a significant behavioral response (take) in MF or HF 
cetaceans. However, if the five 0.1 second pulses are treated as a 5 
second exposure, it would yield an adjusted SEL of approximately 169 
dB, exceeding the behavioral threshold of 167 dB SEL. For impulses 
associated with explosions that have durations of a few microseconds, 
this assumption greatly overestimates effects based on sound exposure 
level metrics such as TTS and PTS and behavioral responses. Appropriate 
weighting values will be applied to the received impulse in one-third 
octave bands and the energy summed to produce a total weighted sound 
exposure level value. For impulsive behavioral criteria, the Navy's 
weighting functions (detailed in Chapter 6 of the LOA application) are 
applied to the received sound level before being compared to the 
threshold.

                               Table 15--Behavioral Thresholds for Impulsive Sound
----------------------------------------------------------------------------------------------------------------
                                            Impulsive behavioral threshold for > 2
              Hearing group                            pulses/24 hours                        Onset TTS
----------------------------------------------------------------------------------------------------------------
Low-Frequency Cetaceans..................  167 dB SEL (LFII)                        172 dB SEL (MFII) or 224 dB
                                                                                     Peak SPL.
Mid-Frequency Cetaceans..................  167 dB SEL (MFII)
High-Frequency Cetaceans.................  141 dB SEL (HFII)                        146 dB SEL (HFII) or 195 dB
                                                                                     Peak SPL.
Phocid Seals (in water)..................  172 dB SEL (PWI)                         177 dB SEL (PWI) or 212 dB
                                                                                     Peak SPL.
Otariidae & Mustelidae (in water)........  195 dB SEL (OWI)                         200 dB SEL (OWI) or 212 dB
                                                                                     Peak SPL.
----------------------------------------------------------------------------------------------------------------
Notes: (1) LFII, MFII, HFII are New compound Type II weighting functions; PWI, OWI = Original Type I (Southall
  et al. 2007) for pinniped and mustelid in water (see Finneran and Jenkins 2012). (2) SEL = re 1 [micro]Pa\2\-
  s; SPL = re 1 [micro]Pa, SEL = Sound Exposure Level, dB = decibel, SPL = Sound Pressure Level.

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. The most appropriate unit of metric for this 
type of analysis is density, which is described as the number of 
animals present per unit area.
    There is no single source of density data for every area, species, 
and season because of the fiscal costs, resources, and effort involved 
in NMFS providing enough survey coverage to sufficiently estimate 
density. Therefore, to characterize the marine species density for 
large areas such as the Study Area, the Navy needed to compile data 
from multiple sources. Each data source may use different methods to 
estimate density, of which, uncertainty in the estimate can be directly 
related to the method applied. To develop a database of marine species 
density estimates, the Navy, in consultation with NMFS experts, adopted 
a protocol to select the best available data sources (including 
habitat-based density models, line-transect analyses, and peer-reviewed 
published studies) based on species, area, and season (see the Navy's 
Pacific Marine Species Density Database Technical Report; U.S. 
Department of the Navy, 2014b). The resulting Geographic Information 
System (GIS) database includes one single spatial and seasonal density 
value for every marine mammal present within the Study Area.
    The Navy Marine Species Density Database includes a compilation of 
the best available density data from several primary sources and 
published works

[[Page 31791]]

including survey data from NMFS within the U.S. EEZ. NMFS is the 
primary agency responsible for estimating marine mammal and sea turtle 
density within the U.S. EEZ. NMFS publishes annual SARs for various 
regions of U.S. waters and covers all stocks of marine mammals within 
those waters. The majority of species that occur in the Study Area are 
covered by the Pacific Region Stock Assessment Report (Carretta et al., 
2014), with a few species (e.g., Steller sea lions) covered by the 
Alaska Region Stock Assessment Report (Allen and Angliss, 2014). Other 
independent researchers often publish density data or research covering 
a particular marine mammal species, which is integrated into the NMFS 
SARs.
    For most cetacean species, abundance is estimated using line-
transect methods that employ a standard equation to derive densities 
based on sighting data collected from systematic ship or aerial 
surveys. More recently, habitat-based density models have been used 
effectively to model cetacean density as a function of environmental 
variables (e.g., Redfern et al., 2006; Barlow et al., 2009; Becker et 
al., 2010; Becker et al., 2012a; Becker et al., 2012b; Becker, 2012c; 
Forney et al., 2012). Where the data supports habitat based density 
modeling, the Navy's database uses those density predictions. Habitat-
based density models allow predictions of cetacean densities on a finer 
spatial scale than traditional line-transect analyses because cetacean 
densities are estimated as a continuous function of habitat variables 
(e.g., sea surface temperature, water depth). Within most of the 
world's oceans, however there have not been enough systematic surveys 
to allow for line-transect density estimation or the development of 
habitat models. To get an approximation of the cetacean species 
distribution and abundance for unsurveyed areas, in some cases it is 
appropriate to extrapolate data from areas with similar oceanic 
conditions where extensive survey data exist. Habitat Suitability 
Indexes or Relative Environmental Suitability have also been used in 
data-limited areas to estimate occurrence based on existing 
observations about a given species' presence and relationships between 
basic environmental conditions (Kaschner et al., 2006).
    Methods used to estimate pinniped at-sea density are generally 
quite different than those described above for cetaceans. Pinniped 
abundance is generally estimated via shore counts of animals at known 
rookeries and haulout sites. For example, for species such as the 
California sea lion, population estimates are based on counts of pups 
at the breeding sites (Carretta et al., 2014). However, this method is 
not appropriate for other species such as harbor seals, whose pups 
enter the water shortly after birth. Population estimates for these 
species are typically made by counting the number of seals ashore and 
applying correction factors based on the proportion of animals 
estimated to be in the water (Carretta et al., 2014). Population 
estimates for pinniped species that occur in the Study Area are 
provided in the Pacific Region Stock Assessment Report (Carretta et 
al., 2014). Translating these population estimates to in-water 
densities presents challenges because the percentage of seals or sea 
lions at sea compared to those on shore is species-specific and depends 
on gender, age class, time of year (molt and breeding/pupping seasons), 
foraging range, and for species such as harbor seal, time of day and 
tide level. These parameters were identified from the literature and 
used to establish correction factors which were then applied to 
estimate the proportion of pinnipeds that would be at sea within the 
Study Area for a given season.
    Density estimates for each species in the Study Area, and the 
sources for these estimates, are provided in Chapter 6 of the LOA 
application and in the Navy's Pacific Marine Species Density Database 
Technical Report (U.S. Department of the Navy, 2014b).

Quantitative Modeling To Estimate Take for Impulsive and Non-Impulsive 
Sound

    The Navy performed a quantitative analysis to estimate the number 
of marine mammals that could be affected by acoustic sources or 
explosives used during Navy training and testing activities. Inputs to 
the quantitative analysis include marine mammal density estimates; 
marine mammal depth occurrence distributions; oceanographic and 
environmental data; marine mammal hearing data; and criteria and 
thresholds for levels of potential effects. The quantitative analysis 
consists of computer modeled estimates and a post-model analysis to 
determine the number of potential harassments. The model calculates 
sound energy propagation from sonar, other active acoustic sources, and 
explosives during naval activities; the sound or impulse received by 
animat (virtual representation of an animal) dosimeters representing 
marine mammals distributed in the area around the modeled activity; and 
whether the sound or impulse received by a marine mammal exceeds the 
thresholds for effects. The model estimates are then further analyzed 
and adjusted to consider animal avoidance (i.e., swimming away from 
sonar or other active sources and away from multiple explosions to 
avoid repeated high level sound exposures) and implementation of 
mitigation measures, resulting in final estimates of potential effects 
due to Navy training and testing.
    Various computer models and mathematical equations can be used to 
predict how energy spreads from a sound source (e.g., sonar or 
underwater detonation) to a receiver (e.g., dolphin or sea turtle). 
Basic underwater sound models calculate the overlap of energy and 
marine life using assumptions that account for the many, variable, and 
often unknown factors that can influence the result. Assumptions in 
previous and current Navy models have intentionally erred on the side 
of overestimation when there are unknowns or when the addition of other 
variables was not likely to substantively change the final analysis. 
For example, because the ocean environment is extremely dynamic and 
information is often limited to a synthesis of data gathered over wide 
areas and requiring many years of research, known information tends to 
be an average of a seasonal or annual variation. El Ni[ntilde]o 
Southern Oscillation events of the ocean-atmosphere system are an 
example of dynamic change where unusually warm or cold ocean 
temperatures are likely to redistribute marine life and alter the 
propagation of underwater sound energy. Previous Navy modeling 
therefore made some assumptions indicative of a maximum theoretical 
propagation for sound energy (such as a perfectly reflective ocean 
surface and a flat seafloor).
    More complex computer models build upon basic modeling by factoring 
in additional variables in an effort to be more accurate by accounting 
for such things as variable bathymetry and an animal's likely presence 
at various depths.
    The Navy has developed new software tools, up to date marine mammal 
density data, and other oceanographic data for the quantification of 
estimated acoustic impacts to marine mammal impacts from Navy 
activities. This new approach is the resulting evolution of the basic 
model previously used by the Navy and reflects a more complex modeling 
approach as described below. The new model, NAEMO, is the standard 
model now used by the Navy to estimate the potential acoustic effects 
of Navy training and testing activities on marine mammals. Although 
this more complex computer modeling approach accounts

[[Page 31792]]

for various environmental factors affecting acoustic propagation, the 
current software tools do not consider the likelihood that a marine 
mammal would attempt to avoid repeated exposures to a sound or avoid an 
area of intense activity where a training or testing event may be 
focused. Additionally, the software tools do not consider the 
implementation of mitigation (e.g., stopping sonar transmissions when a 
marine mammal is within a certain distance of a ship or mitigation zone 
clearance prior to detonations). In both of these situations, naval 
activities are modeled as though an activity would occur regardless of 
proximity to marine mammals and without any horizontal movement by the 
animal away from the sound source or human activities. Therefore, the 
final step of the quantitative analysis of acoustic effects is to 
consider the implementation of mitigation and the possibility that 
marine mammals would avoid continued or repeated sound exposures. This 
final, post-analysis step in the modeling process is meant to better 
quantify the predicted effects by accounting for likely animal 
avoidance behavior and implementation of standard Navy mitigations.
    The incorporation of mitigation factors for the reduction of 
predicted effects used a conservative approach (erring on the side of 
overestimating the number of effects) since reductions as a result of 
implemented mitigation were only applied to those events having a very 
high likelihood of detecting marine mammals. It is important to note 
that there are additional protections offered by mitigation procedures 
which will further reduce effects to marine mammals, but these are not 
considered in the quantitative adjustment of the model predicted 
effects.
    The steps of the quantitative analysis of acoustic effects, the 
values and assumptions that went into the Navy's model, and the 
resulting ranges to effects are detailed in Chapter 6 (Section 6.5) of 
the LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm). Details of the model's processes and the description and 
derivation of the inputs are presented in the Navy's Determination of 
Acoustic Effects technical Report (Marine Species Modeling Team, 2013). 
The post-model analysis, which considers the potential for avoidance 
and highly effective mitigation during the use of sonar and other 
active acoustic sources and explosives, is described in Section 6.5 of 
the LOA application. A detailed explanation of the post-model acoustic 
effect analysis quantification process is also provided in the 
technical report Post-Model Quantitative Analysis of Animal Avoidance 
Behavior and Mitigation Effectiveness for the Northwest Training and 
Testing (U.S. Department of the Navy, 2014c).

Analysis of Guadalupe Fur Seal Exposures

    While there are past and current reports of Guadalupe fur seal 
strandings in the Pacific Northwest, NMFS does not have at-sea 
Guadalupe fur seal sightings from which to derive a density estimate. 
For the NWTT DEIS/OEIS, the Navy elected to take a subset of Northern 
fur seal modeled exposures as a surrogate for Guadalupe fur seals. 
Essentially, a fraction of the northern fur seal modeled exposures from 
the Navy's acoustic effects analysis were used for Guadalupe fur seals 
exposures based on a comparative ratio of expected occurrence offshore 
in the NWTT Study Area for northern fur seals and Guadalupe fur seals 
(based on NMFS stranding records). Northern fur seal at-sea densities 
described in the Navy's Pacific Marine Species Density Database 
Technical Report (U.S. Department of the Navy, 2014b) were derived as a 
single NWTT Study Area wide layer (0.106 animals/km\2\ winter and 
spring, and 0.082 animals/km\2\ summer and fall). The estimated (not 
modeled) results for Guadalupe fur seals were incorporated directly 
into the NWTT DEIS/OEIS (and original December 2013 NWTT LOA 
application).
    This initial analysis, however, was done without consideration of 
the likely differences in biological at-sea distributions of both 
northern fur seals and Guadalupe fur seals. Northern fur seals have a 
documented highly pelagic distribution through the offshore waters of 
the Study Area where the majority of Navy training would occur (Davis 
et al., 2008, NMFS 2007, Lee et al., 2014, Pelland et al., 2014, 
Sterling et al., 2014). This was the justification for the NWTT Study 
Area wide single density values by season (U.S. Department of the Navy, 
2014b). Within the Pacific Northwest, Guadalupe fur seals are more 
likely to be coastally distributed given their extralimital at-sea 
occurrence and associated stranding records (Lambourn et al., 2012).
    The Navy, therefore, has proposed to modify the Guadalupe fur seal 
take number in the NWTT Final EIS/OEIS and has revised the LOA 
application to account for species-specific biological differences in 
at-sea distributions within the NWTT Study Area. This would limit 
Guadalupe fur seal exposures as compared to the process described 
above, as well as more realistically reflect impacts from offshore Navy 
training and testing events. The first step in this reanalysis was an 
examination of the exact Navy events modeled in NAEMO that generated 
exposures for Northern fur seals. The Navy then analyzed the potential 
for co-occurrence of the activities resulting in exposures with the 
Guadalupe fur seal's distribution to determine if the currently 
predicted exposures should be modified. For training, the Navy asserted 
that TRACKEX events typically conducted >50 nm from shore in the NWTT 
Study Area would have limited to no co-occurrence with Guadalupe fur 
seals, and would not result in training related MMPA exposures. TRACKEX 
events account for 82 percent of exposures under the NWTT DEIS/OEIS 
preferred alternative (Table 16). The remaining 18 percent of exposures 
were from offshore submarine sonar maintenance and offshore surface 
ship sonar maintenance. While these events would also likely be further 
offshore, the Navy cannot totally exclude such events from at-sea co-
occurring with the Guadalupe fur seal. For testing, the Navy asserts 
that countermeasure testing and littoral combat ship (LCS) mission 
package testing-ASW typically conducted >50 nm from shore in the NWTT 
Study Area would have limited to no co-occurrence with Guadalupe fur 
seals and would not result in testing MMPA exposures. Countermeasure 
testing and LCS mission package testing-ASW events account for 92 
percent of exposures under the NWTT EIS/OEIS preferred alternative 
(Table 16). The remaining 8 percent of exposures were from various 
testing activities with the majority (5.6 percent) from ASW-guided 
missile destroyer (DDG)-attack submarine (SSN) testing which the Navy 
cannot totally exclude from at-sea co-occurrence with the Guadalupe fur 
seal.
    Based on the results of this analysis, the Navy is modifying 
current NWTT EIS/OEIS take tables and has revised the LOA application 
to account for a percentage decrease in Guadalupe fur seal take 
requests. For this proposed rulemaking, the Guadalupe fur seal Level B 
behavioral take request for training has changed from ``37'' to ``7'' 
(Table 18) and for testing has changed from ``27'' to ``3'' (Table 21).

[[Page 31793]]



 Table 16--Phase II NAEMO Modeled Exposures to Northern Fur Seal in Relationship to Navy Training Events Similar
                                      to NWTRC Phase I Events and for NWTT
----------------------------------------------------------------------------------------------------------------
                                   Dec 2013                                      Revised Navy
                                 Percentage of     Dec 2013      Proposed Aug     recommended
 NWTT events applicable to the   Northern fur    Guadalupe fur       2014        Guadalupe fur      Rational
     NWTT LOA application        seal modeled      seal take     Modification      seal take
                                   exposures        request         amount          request
----------------------------------------------------------------------------------------------------------------
           Training Activities Deemed to Not Have High Probability Of Overlap With Guadalupe Fur Seals
----------------------------------------------------------------------------------------------------------------
TRACKEX (Maritime patrol                    82              37             -30               7  82% of exposures
 aircraft, submarine, surface                                                                    from TRACKEX,
 ship).                                                                                          therefore 30
                                                                                                 exposures (82%
                                                                                                 of 37) can be
                                                                                                 reduced.
----------------------------------------------------------------------------------------------------------------
                      Training Activities That Could Have Overlap With Guadalupe Fur Seals
----------------------------------------------------------------------------------------------------------------
Submarine sonar maintenance...              11
Surface ship sonar maintenance               7
----------------------------------------------------------------------------------------------------------------
           Testing Activities Deemed to Not Have High Probability Of Overlap With Guadalupe Fur Seals
----------------------------------------------------------------------------------------------------------------
NAVSEA countermeasure testing.              81              27             -24               3  92% of exposures
NAVSEA LCS mission package                 11.                                                   from
 testing--ASW.                                                                                   countermeasure
                                                                                                 testing and LCS
                                                                                                 package testing-
                                                                                                 ASW, therefore
                                                                                                 24 exposures
                                                                                                 (92% of 27) can
                                                                                                 be reduced.
----------------------------------------------------------------------------------------------------------------
                       Testing Activities That Could Have Overlap With Guadalupe Fur Seals
----------------------------------------------------------------------------------------------------------------
NAVSEA ASW-DDG-SSN............               6
Various others................             < 1
----------------------------------------------------------------------------------------------------------------

Analysis of Harbor Seal Exposures

    For harbor seals in the inland waters portion of the Study Area, 
there was a change to the Washington Inland Waters stock in 2014 
subsequent to the presentation of the January 2014 NWTT DEIS/OEIS to 
the public. Based on DNA evidence, the single Inland Waters stock was 
broken up into three new stocks, designated the Hood Canal, the 
Washington Northern Inland Waters, and the Southern Puget Sound stocks 
(Carretta et al., 2014). Evidence from tagging data (London et al., 
2012) suggests the Hood Canal stock generally does not forage beyond 
Hood Canal. The Navy has assumed that acoustic effects modeling for 
locations in Hood Canal and Dabob Bay can therefore be accurately 
assigned to the Hood Canal stock. For the Washington Northern Inland 
Waters stock and the Southern Puget Sound stock and because it is 
possible that these stocks overlap while foraging, modeled acoustic 
effects to harbor seals in the inland waters portion of the Study Area 
(excluding Hood Canal and Dabob Bay) were therefore assigned to the 
appropriate stock using a derived ratio based on the abundance 
estimates for the two stocks as reported in the 2013 Pacific Stock 
Assessment Report (Carretta et al. (2014); Washington Northern Inland 
Waters stock: n = 11,036; Southern Puget Sound stock: n = 1,568). The 
ratio of the Washington Northern Inland Waters stock (0.88) to that of 
the Southern Puget Sound stock (0.12) was then used to prorate the 
total modeled exposures in order to estimate acoustic exposures for 
each of these stocks in the inland waters portion of the Study Area.
    As a result of the changes to the harbor seal abundance and haulout 
assumptions for the Hood Canal stock, for this proposed rulemaking the 
harbor seal Level B behavioral take request has increased by an 
additional 417 takes for training (Table 18) and an additional 52,970 
takes (Table 21) for testing. The Level A take request has increased an 
additional 4 takes for training (Table 18) and an additional 61 takes 
for testing (Table 21).

Take Request

    The January 2014 NWTT DEIS/OEIS considered all training and testing 
activities proposed to occur in the Study Area that have the potential 
to result in the MMPA defined take of marine mammals. The potential 
stressors associated with these activities included the following:
     Acoustic (sonar and other active non-impulse sources, 
explosives, swimmer defense airguns, weapons firing, launch and impact 
noise, vessel noise, aircraft noise);
     Energy (electromagnetic devices);
     Physical disturbance or strikes (vessels, in-water 
devices, military expended materials, seafloor devices);
     Entanglement (fiber optic cables, guidance wires, 
parachutes);
     Ingestion (munitions, military expended materials other 
than munitions); and
     Secondary stressors (sediments and water quality).
    NMFS has determined that two stressors could potentially result in 
the incidental taking of marine mammals from training and testing 
activities within the Study Area: (1) Non-impulsive stressors (sonar 
and other active acoustic sources) and (2) impulsive stressors 
(explosives). Non-impulsive and impulsive stressors have the potential 
to result in incidental takes of marine mammals by harassment, injury, 
or mortality. NMFS also considered the potential for vessel strikes to 
impact marine mammals, and that assessment is presented below.

Training Activities

    A detailed analysis of effects due to marine mammal exposures to 
impulsive and non-impulsive sources in the Study Area is presented in 
Chapter 6 of the LOA application. Based on the model and post-model 
analysis described in Chapter 6 of the LOA application, Table 17 
summarizes the Navy's final take request for training activities for a 
year (a 12-month period) and the summation over a 5-year period (annual 
events occurring five times and the non-annual event occurring three 
times). The Civilian Port Defense exercise is a non-

[[Page 31794]]

annual event and is analyzed as occurring every other year, or three 
times during the 5-year period considered in this analysis. Annual 
totals presented in the tables are the summation of all annual events 
plus all the proposed non-annual events occurring in a 12-month period 
as a maximum year.

 Table 17--Summary of Annual and 5-Year Take Requests for NWTT Training
                               Activities
------------------------------------------------------------------------
                                               Training activities
                                       ---------------------------------
    MMPA category           Source           Annual           5-Year
                                         authorization    authorization
                                             sought           sought
------------------------------------------------------------------------
Level A..............  Impulsive and..  11--Species      55--Species
                       Non-Impulsive..   specific data    specific data
                                         shown in         shown in
                                         Tables 16 and    Tables 16 and
                                         17.              17.
Level B..............  Impulsive and..  107,459--Specie  533,543--Specie
                       Non-Impulsive..   s specific       s specific
                                         data shown in    data shown in
                                         Tables 16 and    Tables 16 and
                                         17.              17.
------------------------------------------------------------------------

Impulsive and Non-Impulsive Sources

    Table 18 provides the Navy's take request for training activities 
by species from the acoustic effects modeling estimates. The numbers 
provided in the annual columns are the totals for a maximum year (i.e., 
a year in which a Civilian Port Defense Occurs). Table 19 provides the 
contribution to the maximum year total (1,876 Level B exposures) 
resulting from the biennial Civilian Port Defense exercise. The 5-year 
totals presented assume the biennial event would occur three times over 
the 5-year period (in the first, third, and fifth years). Derivations 
of the numbers presented in Tables 18 and 19 are described in more 
detail within Chapter 6 of the LOA application. There are no 
mortalities predicted for any training activities resulting from the 
use of impulsive or non-impulsive sources. Values shown in Table 18 
also include Level B values from non-annual Civilian Port Defense 
training events.

 Table 18--Species-Specific Take Requests From Modeling and Post-Model Estimates of Impulsive and Non-Impulsive
                                   Source Effects for all Training Activities
----------------------------------------------------------------------------------------------------------------
                                                                       Annual                    5-Year
               Species                         Stock         ---------------------------------------------------
                                                                Level B      Level A      Level B      Level A
----------------------------------------------------------------------------------------------------------------
North Pacific right whale...........  Eastern North Pacific.            0            0            0            0
Humpback whale......................  Central North Pacific.            0            0            0            0
                                      California, Oregon, &            12            0           60            0
                                       Washington.
Blue whale..........................  Eastern North Pacific.            5            0           25            0
Fin whale...........................  Northeast Pacific.....            0            0            0            0
                                      California, Oregon, &            25            0          125            0
                                       Washington.
Sei whale...........................  Eastern North Pacific.            0            0            0            0
Minke whale.........................  Alaska................            0            0            0            0
                                      California, Oregon, &            18            0           90            0
                                       Washington.
Gray whale..........................  Eastern North Pacific.            6            0           30            0
                                      Western North Pacific.            0            0            0            0
Sperm whale.........................  North Pacific.........            0            0            0            0
                                      California, Oregon, &            81            0          405            0
                                       Washington.
Kogia (spp.)........................  California, Oregon, &            73            0          365            0
                                       Washington.
Killer whale........................  Alaska Resident.......            0            0            0            0
                                      Northern Resident.....            0            0            0            0
                                      West Coast Transient..            9            0           39            0
                                      East N. Pacific                  13            0           65            0
                                       Offshore.
                                      East N. Pacific                   2            0            6            0
                                       Southern Resident.
Short-finned pilot whale............  California, Oregon, &             0            0            0            0
                                       Washington.
Short-beaked common dolphin.........  California, Oregon, &           734            0        3,670            0
                                       Washington.
Bottlenose dolphin..................  California, Oregon, &             0            0            0            0
                                       Washington.
Striped dolphin.....................  California, Oregon, &            22            0          110            0
                                       Washington.
Pacific white-sided dolphin.........  North Pacific.........            0            0            0            0
                                      California, Oregon, &         3,482            0       17,408            0
                                       Washington.
Northern right whale dolphin........  California, Oregon, &         1,332            0        6,660            0
                                       Washington.
Risso's dolphin.....................  California, Oregon, &           657            0        3,285            0
                                       Washington.
Harbor porpoise.....................  Southeast Alaska......            0            0            0            0
                                      Northern OR/WA Coast..       35,006            0      175,030            0
                                      Northern CA/Southern         52,509            0      262,545            0
                                       OR.
                                      WA Inland Waters......        1,417            1        4,409            5
Dall's porpoise.....................  Alaska................            0            0            0            0
                                      California, Oregon, &         3,732            4       18,188           20
                                       Washington.
Cuvier's beaked whale...............  Alaska................            0            0            0            0
                                      California, Oregon, &           353            0        1,765            0
                                       Washington.
Baird's beaked whale................  Alaska................            0            0            0            0
                                      California, Oregon, &           591            0        2,955            0
                                       Washington.
Mesoplodon beaked whales............  California, Oregon, &         1,417            0        7,085            0
                                       Washington.
Steller sea lion....................  Eastern U.S...........          404            0        1,986            0
Guadalupe fur seal..................  San Miguel Island.....            7            0           35            0
California sea lion.................  U.S. Stock............          814            0        4,038            0
Northern fur seal...................  Eastern Pacific.......        2,495            0       12,475            0

[[Page 31795]]

 
                                      California............           37            0          185            0
Northern elephant seal..............  California Breeding...        1,271            0        6,353            0
Harbor seal.........................  Southeast Alaska                  0            0            0            0
                                       (Clarence Strait).
                                      OR/WA Coast...........            0            0            0            0
                                      California............            0            0            0            0
                                      WA Northern Inland              427            4        1,855           20
                                       Waters.
                                      Southern Puget Sound..           58            0          252            0
                                      Hood Canal............          452            2        2,054           10
----------------------------------------------------------------------------------------------------------------


   Table 19--Training Exposures Specific to the Biennial Civilian Port
                            Defense Exercise
[Values provided for informational purposes and are included in Table 18
                        species-specific totals]
------------------------------------------------------------------------
                                                        Biennial
           Species                  Stock      -------------------------
                                                  Level B      Level A
------------------------------------------------------------------------
North Pacific right whale....  Eastern North              0            0
                                Pacific.
Humpback whale...............  Central North              0            0
                                Pacific.
                               California,                0            0
                                Oregon, &
                                Washington.
Blue whale...................  Eastern North              0            0
                                Pacific.
Fin whale....................  Northeast                  0            0
                                Pacific.
                               California,                0            0
                                Oregon, &
                                Washington.
Sei whale....................  Eastern North              0            0
                                Pacific.
Minke whale..................  Alaska.........            0            0
                               California,                0            0
                                Oregon, &
                                Washington.
Gray whale...................  Eastern North              0            0
                                Pacific.
                               Western North              0            0
                                Pacific.
Sperm whale..................  North Pacific..            0            0
                               California,                0            0
                                Oregon, &
                                Washington.
Kogia (spp.).................  California,                0            0
                                Oregon, &
                                Washington.
Killer whale.................  Alaska Resident            0            0
                               Northern                   0            0
                                Resident.
                               West Coast                 3            0
                                Transient.
                               East N. Pacific            0            0
                                Offshore.
                               East N. Pacific            2            0
                                Southern
                                Resident.
Short-finned pilot whale.....  California,                0            0
                                Oregon, &
                                Washington.
Short-beaked common dolphin..  California,                0            0
                                Oregon, &
                                Washington.
Bottlenose dolphin...........  California,                0            0
                                Oregon, &
                                Washington.
Striped dolphin..............  California,                0            0
                                Oregon, &
                                Washington.
Pacific white-sided dolphin..  North Pacific..            0            0
                               California,                1            0
                                Oregon, &
                                Washington.
Northern right whale dolphin.  California,                0            0
                                Oregon, &
                                Washington.
Risso's dolphin..............  California,                0            0
                                Oregon, &
                                Washington.
Harbor porpoise..............  Southeast                  0            0
                                Alaska.
                               Northern OR/WA             0            0
                                Coast.
                               Northern CA/               0            0
                                Southern OR.
                               WA Inland              1,338            0
                                Waters.
Dall's porpoise..............  Alaska.........            0            0
                               California,              236            0
                                Oregon, &
                                Washington.
Cuvier's beaked whale........  Alaska.........            0            0
                               California,                0            0
                                Oregon, &
                                Washington.
Baird's beaked whale.........  Alaska.........            0            0
                               California,                0            0
                                Oregon, &
                                Washington.
Mesoplodon beaked whales.....  California,                0            0
                                Oregon, &
                                Washington.
Steller sea lion.............  Eastern U.S....           17            0
Guadalupe fur seal...........  San Miguel                 0            0
                                Island.
California sea lion..........  U.S. Stock.....           16            0
Northern fur seal............  Eastern Pacific            0            0
                               California.....            0            0
Northern elephant seal.......  California                 1            0
                                Breeding.
Harbor seal..................  Southeast                  0            0
                                Alaska
                                (Clarence
                                Strait).
                               OR/WA Coast....            0            0
                               California.....            0            0
                               WA Northern              140            0
                                Inland Waters.
                               Southern Puget            19            0
                                Sound.
                               Hood Canal.....          103            0
------------------------------------------------------------------------


[[Page 31796]]

Vessel Strike

    There has never been a vessel strike to marine mammals during any 
training activities in the Study Area. A detailed analysis of strike 
data is contained in Section 6.7 (Estimated Take of Large Whales by 
Navy Vessel Strike) of the LOA application. The Navy does not 
anticipate vessel strikes to marine mammals within the Study Area, nor 
were takes by injury or mortality resulting from vessel strike 
predicted in the Navy's analysis. Therefore, takes by injury or 
mortality resulting from vessel strikes are not authorized by NMFS in 
this proposed rule. However, the Navy has proposed measures (see 
Proposed Mitigation) to mitigate potential impacts to marine mammals 
from vessel strikes during training activities in the Study Area.

Testing Activities

    A detailed analysis of effects due to marine mammal exposures to 
impulsive and non-impulsive sources in the Study Area is presented in 
Chapter 6 of the LOA application. Based on the model and post-model 
analysis described in Chapter 6 of the LOA application, Table 20 
summarizes the Navy's final take request for testing activities for an 
annual (12-month) period and the summation over a 5-year period. There 
are no non-annual testing events.

  Table 20--Summary of Annual and 5-Year Take Requests for NWTT Testing
                               Activities
------------------------------------------------------------------------
                                               Testing activities
                                       ---------------------------------
    MMPA  category          Source           Annual           5-Year
                                         authorization    authorization
                                             sought           sought
------------------------------------------------------------------------
Level A..............  Impulsive and    176--Species     880--Species
                        Non-Impulsive.   specific data    specific data
                                         shown in         shown in
                                         Tables 18 and    Tables 18 and
                                         19.              19.
Level B..............  Impulsive and    139,815--Specie  699,075--Specie
                        Non-Impulsive.   s specific       s specific
                                         data shown in    data shown in
                                         Tables 18 and    Tables 18 and
                                         19.              19.
------------------------------------------------------------------------

Impulsive and Non-Impulsive Sources

    Table 21 summarizes the Navy's take request for testing activities 
by species. There are no non-annual testing events. Derivation of these 
values is described in more detail within Chapter 6 of the LOA 
application. There are no mortalities predicted for any testing 
activities based on the analysis of impulsive and non-impulsive 
sources.

 Table 21--Species-Specific Take Requests From Modeling and Post-Model Estimates of Impulsive and Non-Impulsive
                                    Source Effects for All Testing Activities
----------------------------------------------------------------------------------------------------------------
                                                                       Annual                    5-Year
               Species                         Stock         ---------------------------------------------------
                                                                Level B      Level A      Level B      Level A
----------------------------------------------------------------------------------------------------------------
North Pacific right whale...........  Eastern North Pacific.            0            0            0            0
Humpback whale......................  Central North Pacific.            1            0            5            0
                                      California, Oregon, &            44            0          220            0
                                       Washington.
Blue whale..........................  Eastern North Pacific.            6            0           30            0
Fin whale...........................  Northeast Pacific.....            2            0           10            0
                                      California, Oregon, &            34            0          170            0
                                       Washington.
Sei whale...........................  Eastern North Pacific.            2            0           10            0
Minke whale.........................  Alaska................            0            0            0            0
                                      California, Oregon, &            18            0           90            0
                                       Washington.
Gray whale..........................  Eastern North Pacific.           11            0           55            0
                                      Western North Pacific.            0            0            0            0
Sperm whale.........................  North Pacific.........            0            0            0            0
                                      California, Oregon, &            78            0          390            0
                                       Washington.
Kogia (spp.)........................  California, Oregon, &           106            1          530            5
                                       Washington.
Killer Whale........................  Alaska Resident.......            2            0           10            0
                                      Northern Resident.....            0            0            0            0
                                      West Coast Transient..          202            0        1,010            0
                                      East N. Pacific                  22            0          110            0
                                       Offshore.
                                      East N. Pacific                   0            0            0            0
                                       Southern Resident.
Short-finned pilot whale............  California, Oregon, &             0            0            0            0
                                       Washington.
Short-beaked common dolphin.........  California, Oregon, &         1,628            0        8,140            0
                                       Washington.
Bottlenose dolphin..................  California, Oregon, &             0            0            0            0
                                       Washington.
Striped dolphin.....................  California, Oregon, &            14            0           70            0
                                       Washington.
Pacific white-sided dolphin.........  North Pacific.........            3            0           15            0
                                      California, Oregon, &         4,869            0       24,345            0
                                       Washington.
Northern right whale dolphin........  California, Oregon, &         2,038            0       10,190            0
                                       Washington.
Risso's dolphin.....................  California, Oregon, &         1,154            0        5,770            0
                                       Washington.
Harbor porpoise.....................  Southeast Alaska......          926            0        4,630            0
                                      Northern OR/WA Coast..       17,212           15       86,060           75
                                      Northern CA/Southern         25,819           23      129,095          115
                                       OR.
                                      WA Inland Waters......        5,336            6       26,680           30
Dall's porpoise.....................  Alaska................        1,200            0        6,000            0
                                      California, Oregon, &        10,139           43       50,695          215
                                       Washington.
Cuvier's beaked whale...............  Alaska................           15            0           75            0
                                      California, Oregon, &            91            0          455            0
                                       Washington.
Baird's beaked whale................  Alaska................           25            0          125            0

[[Page 31797]]

 
                                      California, Oregon, &           149            0          745            0
                                       Washington.
Mesoplodon beaked whales............  California, Oregon, &           369            0        1,845            0
                                       Washington.
Steller sea lion....................  Eastern U.S...........          504            0        2,520            0
Guadalupe fur seal..................  San Miguel Island.....            3            0           15            0
California sea lion.................  U.S. Stock............        2,073            0       10,365            0
Northern fur seal...................  Eastern Pacific.......        1,830            0        9,150            0
                                      California............           27            0          135            0
Northern elephant seal..............  California Breeding...        1,325            2         6625           10
Harbor seal.........................  Southeast Alaska                 22            0          110            0
                                       (Clarence Strait).
                                      OR/WA Coast...........        1,655            4        8,275           20
                                      California............            0            0            0            0
                                      WA Northern Inland            1,448           14        7,240           70
                                       Waters.
                                      Southern Puget Sound..          196            1          980            5
                                      Hood Canal............       59,217           67      296,085          335
----------------------------------------------------------------------------------------------------------------

Vessel Strike

    There has never been a vessel strike to marine mammals during any 
testing activities in the Study Area. A detailed analysis of strike 
data is contained in Section 6.7 (Estimated Take of Large Whales by 
Navy Vessel Strike) of the LOA application. Testing activities 
involving vessel movement could mainly occur in the Inland Waters and 
in Western Behm Canal with some additional testing activities in the 
offshore region. The majority of vessels used in the Inland Waters and 
Western Behm Canal are smaller vessels, which are less likely to be 
involved in a whale strike. The Navy's proposed actions would not 
result in any appreciable changes in locations or frequency of vessel 
activity, and there have been no whale strikes during any previous 
testing activities in the Study Area. The manner in which the Navy has 
tested would remain consistent with the range of variability observed 
over the last decade so the Navy does not anticipate vessel strikes 
would occur within the Study Area during testing events. Further, takes 
by injury or mortality resulting from vessel strike were not predicted 
in the Navy's analysis. As such, NMFS is not authorizing take by injury 
or mortality resulting from vessel strike this proposed rule. However, 
the Navy has proposed measures (see Proposed Mitigation) to mitigate 
potential impacts to marine mammals from vessel strikes during testing 
activities in the Study Area.

Analysis and Negligible Impact Determination

    Negligible impact is ``an impact resulting from the specified 
activity that cannot be reasonably expected to, and is not reasonably 
likely to, adversely affect the species or stock through effects on 
annual rates of recruitment or survival'' (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes, alone, is not 
enough information on which to base an impact determination, as the 
severity of harassment may vary greatly depending on the context and 
duration of the behavioral response, many of which would not be 
expected to have deleterious impacts on the fitness of any individuals. 
In determining whether the expected takes will have a negligible 
impact, in addition to considering estimates of the number of marine 
mammals that might be ``taken'', NMFS must consider other factors, such 
as the likely nature of any responses (their intensity, duration, 
etc.), the context of any responses (critical reproductive time or 
location, migration, etc.), as well as the number and nature (e.g., 
severity) of estimated Level A harassment takes, the number of 
estimated mortalities, and the status of the species.
    The Navy's specified activities have been described based on best 
estimates of the maximum amount of sonar and other acoustic source use 
or detonations that the Navy would conduct. There may be some 
flexibility in that the exact number of hours, items, or detonations 
may vary from year to year, but take totals are not authorized to 
exceed the 5-year totals indicated in Tables 17-21. However, it is also 
worth noting here that while models that incorporate realistic 
environmental, operational, and biological parameters are the best way 
to satisfy our need to quantify takes, and are very useful in our 
analysis (especially where subsets of takes can be pared with factors 
associated with differential expected levels of severity or duration), 
due to the inherent variability and uncertainty in model inputs, 
modeled take estimates are never expected to represent the exact number 
of animals that will actually be taken, but rather can provide 
(depending on nature of model) a decent relative understanding of the 
portion of a population that might be affected and/or the number of 
repeat takes of individuals on subsequent days that might occur.
    The Navy's take request is based on their model and post-model 
analysis. Generally speaking, and especially with other factors being 
equal, the Navy and NMFS anticipate more severe effects from takes 
resulting from exposure to higher received levels (though this is in no 
way a strictly linear relationship throughout species, individuals, or 
circumstances) and less severe effects from takes resulting from 
exposure to lower received levels. The requested number of Level B 
takes does not equate to the number of individual animals the Navy 
expects to harass (which is lower), but rather to the instances of take 
(i.e., exposures above the Level B harassment threshold) that would 
occur. Additionally, these instances may represent either a very brief 
exposure (seconds) or, in some cases, longer durations of exposure 
within a day. Depending on the location, duration, and frequency of 
activities, along with the distribution and movement of marine mammals, 
individual animals may be exposed to impulse or non-impulse sounds at 
or above the Level B harassment threshold on multiple days. However, 
the Navy is currently unable to estimate the number of individuals that 
may be taken during training and testing activities. The model results 
estimate the total number of takes that may occur to a smaller number 
of

[[Page 31798]]

individuals. While the model shows that an increased number of 
exposures may take place due to an increase in events/activities and 
ordnance, the types and severity of individual responses to training 
and testing activities are not expected to change.
    It is important to note that, while NMFS does not expect that all 
of the requested and authorized takes (as shown in Tables 17-21 and 
based on the acoustic analysis) will actually occur, we nevertheless 
base our analysis and NID on the maximum number of takes requested and 
authorized (i.e., not on a lower number of takes anticipated).

Behavioral Harassment

    As discussed previously in this document, marine mammals can 
respond to MFAS/HFAS in many different ways, a subset of which 
qualifies as harassment (see Behavioral Harassment Section). One thing 
that the Level B harassment take estimates do not take into account is 
the fact that most marine mammals will likely avoid strong sound 
sources to one extent or another. Although an animal that avoids the 
sound source will likely still be taken in some instances (such as if 
the avoidance results in a missed opportunity to feed, interruption of 
reproductive behaviors, etc.), in other cases avoidance may result in 
fewer instances of take than were estimated or in the takes resulting 
from exposure to a lower received level than was estimated, which could 
result in a less severe response. For MFAS/HFAS, the Navy provided 
information (Table 22) estimating the percentage of behavioral 
harassment that would occur within the 6-dB bins (without considering 
mitigation or avoidance). As mentioned above, an animal's exposure to a 
higher received level is more likely to result in a behavioral response 
that is more likely to adversely affect the health of the animal. As 
illustrated below, the majority (about 73 percent, at least for hull-
mounted sonar, which is responsible for most of the sonar takes) of 
calculated takes from MFAS result from exposures between 156 dB and 162 
dB. Less than 0.5 percent of the takes are expected to result from 
exposures above 174 dB.
    Specifically, given a range of behavioral responses that may be 
classified as Level B harassment, to the degree that higher received 
levels are expected to result in more severe behavioral responses, only 
a small percentage of the anticipated Level B harassment from Navy 
activities might necessarily be expected to potentially result in more 
severe responses, especially when the distance from the source at which 
the levels below are received is considered (see Table 22). Marine 
mammals are able to discern the distance of a given sound source, and 
given other equal factors (including received level), they have been 
reported to respond more to sounds that are closer (DeRuiter et al., 
2013). Further, the estimated number of responses do not reflect either 
the duration or context of those anticipated responses, some of which 
will be of very short duration, and other factors should be considered 
when predicting how the estimated takes may affect individual fitness.

                                  Table 22--Non-Impulsive Ranges in 6-dB Bins and Percentage of Behavioral Harassments
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                  Sonar Bin MF1 (e.g., SQS-53; ASW   Sonar Bin MF4 (e.g., AQS-22; ASW   Sonar Bin MF5 (e.g., SSQ-62; ASW
                                                        Hull Mounted Sonar)                   Dipping Sonar)                       Sonobuoy)
                                                --------------------------------------------------------------------------------------------------------
                                                                     Percentage of                      Percentage of                      Percentage of
                 Received Level                  Distance at which    behavioral    Distance at which    behavioral    Distance at which    behavioral
                                                    levels occur      harassments      levels occur      harassments      levels occur      harassments
                                                  within radius of   occurring at    within radius of   occurring at    within radius of   occurring at
                                                     source (m)      given levels       source (m)      given levels       source (m)      given levels
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low Frequency Cetaceans
120 <=SPL <126.................................    178,750-156,450            0.00     100,000-92,200            0.00      22,800-15,650            0.00
126 <=SPL <132.................................    156,450-147,500            0.00      92,200-55,050            0.11      15,650-11,850            0.05
132 <=SPL <138.................................    147,500-103,700            0.21      55,050-46,550            1.08       11,850-6,950            2.84
138 <=SPL <144.................................     103,700-97,950            0.33      46,550-15,150           35.69        6,950-3,600           16.04
144 <=SPL <150.................................      97,950-55,050           13.73       15,150-5,900           26.40        3,600-1,700           33.63
150 <=SPL <156.................................      55,050-49,900            5.28        5,900-2,700           17.43          1,700-250           44.12
156 <=SPL <162.................................      49,900-10,700           72.62        2,700-1,500            9.99            250-100            2.56
162 <=SPL <168.................................       10,700-4,200            6.13          1,500-200            9.07            100-<50            0.76
168 <=SPL <174.................................        4,200-1,850            1.32            200-100            0.18                <50            0.00
174 <=SPL <180.................................          1,850-850            0.30            100-<50            0.05                <50            0.00
180 <=SPL <186.................................            850-400            0.07                <50            0.00                <50            0.00
186 <=SPL <192.................................            400-200            0.01                <50            0.00                <50            0.00
192 <=SPL <198.................................            200-100            0.00                <50            0.00                <50            0.00
Mid Frequency Cetaceans
120 <=SPL <126.................................    179,400-156,450            0.00     100,000-92,200            0.00      23,413-16,125            0.00
126 <=SPL <132.................................    156,450-147,500            0.00      92,200-55,050            0.11      16,125-11,500            0.06
132 <=SPL <138.................................    147,500-103,750            0.21      55,050-46,550            1.08       11,500-6,738            2.56
138 <=SPL <144.................................     103,750-97,950            0.33      46,550-15,150           35.69        6,738-3,825           13.35
144 <=SPL <150.................................      97,950-55,900           13.36       15,150-5,900           26.40        3,825-1,713           37.37
150 <=SPL <156.................................      55,900-49,900            6.12        5,900-2,700           17.43          1,713-250           42.85
156 <=SPL <162.................................      49,900-11,450           71.18        2,700-1,500            9.99            250-150            1.87
162 <=SPL <168.................................       11,450-4,350            7.01          1,500-200            9.07            150-<50            1.93
168 <=SPL <174.................................        4,350-1,850            1.42            200-100            0.18                <50            0.00
174 <=SPL <180.................................          1,850-850            0.29            100-<50            0.05                <50            0.00
180 <=SPL <186.................................            850-400            0.07                <50            0.00                <50            0.00
186 <=SPL <192.................................            400-200            0.01                <50            0.00                <50            0.00
192 <=SPL <198.................................            200-100            0.00                <50            0.00                <50            0.00
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes: (1) ASW = anti-submarine warfare, m = meters, SPL = sound pressure level; (2) Odontocete behavioral response function is also used for high-
  frequency cetaceans, phocid seals, otariid seals and sea lions, and sea otters.


[[Page 31799]]

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

Diel Cycle

    As noted previously, many animals perform vital functions, such as 
feeding, resting, traveling, and socializing on a diel cycle (24-hour 
cycle). Behavioral reactions to noise exposure (when taking place in a 
biologically important context, such as disruption of critical life 
functions, displacement, or avoidance of important habitat) are more 
likely to be significant if they last more than one diel cycle or recur 
on subsequent days (Southall et al., 2007). Consequently, a behavioral 
response lasting less than one day and not recurring on subsequent days 
is not considered severe unless it could directly affect reproduction 
or survival (Southall et al., 2007). Note that there is a difference 
between multiple-day substantive behavioral reactions and multiple-day 
anthropogenic activities. For example, just because at-sea exercises 
last for multiple days does not necessarily mean that individual 
animals are either exposed to those exercises for multiple days or, 
further, exposed in a manner resulting in a sustained multiple day 
substantive behavioral response. Large multi-day Navy exercises 
typically include assets that travel at high speeds (typically 10-15 
knots, or higher) and likely cover large areas that are relatively far 
from shore, in addition to the fact that marine mammals are moving as 
well, which would make it unlikely that the same animal could remain in 
the immediate vicinity of the ship for the entire duration of the 
exercise. Additionally, the Navy does not necessarily operate active 
sonar the entire time during an exercise. While it is certainly 
possible that these sorts of exercises could overlap with individual 
marine mammals multiple days in a row at levels above those anticipated 
to result in a take, because of the factors mentioned above, it is 
considered not to be likely for the majority of takes, does not mean 
that a behavioral response is necessarily sustained for multiple days, 
and still necessitates the consideration of likely duration and context 
to assess any effects on the individual's fitness.
    Durations for non-impulsive activities utilizing tactical sonar 
sources vary and are fully described in Appendix A of the January 2014 
DEIS/OEIS. ASW training and testing exercises using MFAS/HFAS generally 
last for 2-16 hours, and may have intervals of non-activity in between. 
Because of the need to train in a large variety of situations, the Navy 
does not typically conduct successive MTEs or other ASW exercises in 
the same locations. Given the average length of ASW exercises (times of 
continuous sonar use) and typical vessel speed, combined with the fact 
that the majority of the cetaceans in the Study Area would not likely 
remain in an area for successive days, it is unlikely that an animal 
would be exposed to MFAS/HFAS at levels likely to result in a 
substantive response that would then be carried on for more than one 
day or on successive days. There are no MTEs proposed for NWTT 
activities.
    Most planned explosive exercises are of a short duration (1-6 
hours). Although explosive exercises may sometimes be conducted in the 
same general areas repeatedly, because of their short duration and the 
fact that they are in the open ocean and animals can easily move away, 
it is similarly unlikely that animals would be exposed for long, 
continuous amounts of time.

TTS

    As mentioned previously, TTS can last from a few minutes to days, 
be of varying degree, and occur across various frequency bandwidths, 
all of which determine the severity of the impacts on the affected 
individual, which can range from minor to more severe. The TTS 
sustained by an animal is primarily classified by three 
characteristics:
    1. Frequency--Available data (of mid-frequency hearing specialists 
exposed to mid- or high-frequency sounds; Southall et al., 2007) 
suggest that most TTS occurs in the frequency range of the source up to 
one octave higher than the source (with the maximum TTS at \1/2\ octave 
above). The more powerful MF sources used have center frequencies 
between 3.5 and 8 kHz and the other unidentified MF sources are, by 
definition, less than 10 kHz, which suggests that TTS induced by any of 
these MF sources would be in a frequency band somewhere between 
approximately 2 and 20 kHz. There are fewer hours of HF source use and 
the sounds would attenuate more quickly, plus they have lower source 
levels, but if an animal were to incur TTS from these sources, it would 
cover a higher frequency range (sources are between 20 and 100 kHz, 
which means that TTS could range up to 200 kHz; however, HF systems are 
typically used less frequently and for shorter time periods than 
surface ship and aircraft MF systems, so TTS from these sources is even 
less likely). TTS from explosives would be broadband. Vocalization data 
for each species, which would inform how TTS might specifically 
interfere with communications with conspecifics, was provided in the 
LOA application.
    2. Degree of the shift (i.e., by how many dB the sensitivity of the 
hearing is reduced)--Generally, both the degree of TTS and the duration 
of TTS will be greater if the marine mammal is exposed to a higher 
level of energy (which would occur when the peak dB level is higher or 
the duration is longer). The threshold for the onset of TTS was 
discussed previously in this document. An animal would have to approach 
closer to the source or remain in the vicinity of the sound source 
appreciably longer to increase the received SEL, which would be 
difficult considering the Lookouts and the nominal speed of an active 
sonar vessel (10-15 knots). In the TTS studies, some using exposures of 
almost an hour in duration or up to 217 SEL, most of the TTS induced 
was 15 dB or less, though Finneran et al. (2007) induced 43 dB of TTS 
with a 64-second exposure to a 20 kHz source. However, MFAS emits a 
nominal ping every 50 seconds, and incurring those levels of TTS is 
highly unlikely.
    3. Duration of TTS (recovery time)--In the TTS laboratory studies, 
some using exposures of almost an hour in duration or up to 217 SEL, 
almost all individuals recovered within 1 day (or less, often in 
minutes), although in one study (Finneran et al., 2007), recovery took 
4 days.
    Based on the range of degree and duration of TTS reportedly induced 
by exposures to non-pulse sounds of energy higher than that to which 
free-swimming marine mammals in the field are likely to be exposed 
during MFAS/HFAS training exercises in the Study Area, it is unlikely 
that marine mammals would ever sustain a TTS

[[Page 31800]]

from MFAS that alters their sensitivity by more than 20 dB for more 
than a few days (and any incident of TTS would likely be far less 
severe due to the short duration of the majority of the exercises and 
the speed of a typical vessel). Also, for the same reasons discussed in 
the Diel Cycle section, and because of the short distance within which 
animals would need to approach the sound source, it is unlikely that 
animals would be exposed to the levels necessary to induce TTS in 
subsequent time periods such that their recovery is impeded. 
Additionally, though the frequency range of TTS that marine mammals 
might sustain would overlap with some of the frequency ranges of their 
vocalization types, the frequency range of TTS from MFAS (the source 
from which TTS would most likely be sustained because the higher source 
level and slower attenuation make it more likely that an animal would 
be exposed to a higher received level) would not usually span the 
entire frequency range of one vocalization type, much less span all 
types of vocalizations or other critical auditory cues. If impaired, 
marine mammals would typically be aware of their impairment and are 
sometimes able to implement behaviors to compensate (see Acoustic 
Masking or Communication Impairment section), though these 
compensations may incur energetic costs.

Acoustic Masking or Communication Impairment

    Masking only occurs during the time of the signal (and potential 
secondary arrivals of indirect rays), versus TTS, which continues 
beyond the duration of the signal. Standard MFAS nominally pings every 
50 seconds for hull-mounted sources. For the sources for which we know 
the pulse length, most are significantly shorter than hull-mounted 
active sonar, on the order of several microseconds to tens of 
microseconds. For hull-mounted active sonar, though some of the 
vocalizations that marine mammals make are less than one second long, 
there is only a 1 in 50 chance that they would occur exactly when the 
ping was received, and when vocalizations are longer than one second, 
only parts of them are masked. Alternately, when the pulses are only 
several microseconds long, the majority of most animals' vocalizations 
would not be masked. Masking effects from MFAS/HFAS are expected to be 
minimal. If masking or communication impairment were to occur briefly, 
it would be in the frequency range of MFAS, which overlaps with some 
marine mammal vocalizations; however, it would likely not mask the 
entirety of any particular vocalization, communication series, or other 
critical auditory cue, because the signal length, frequency, and duty 
cycle of the MFAS/HFAS signal does not perfectly mimic the 
characteristics of any marine mammal's vocalizations.

PTS, Injury, or Mortality

    NMFS believes that many marine mammals would deliberately avoid 
exposing themselves to the received levels of active sonar necessary to 
induce injury by moving away from or at least modifying their path to 
avoid a close approach. Additionally, in the unlikely event that an 
animal approaches the sonar vessel at a close distance, NMFS believes 
that the mitigation measures (i.e., shutdown/powerdown zones for MFAS/
HFAS) would typically ensure that animals would not be exposed to 
injurious levels of sound. As discussed previously, the Navy utilizes 
both aerial (when available) and passive acoustic monitoring (during 
all ASW exercises) in addition to watchstanders on vessels to detect 
marine mammals for mitigation implementation.
    If a marine mammal is able to approach a surface vessel within the 
distance necessary to incur PTS, the likely speed of the vessel 
(nominal 10-15 knots) would make it very difficult for the animal to 
remain in range long enough to accumulate enough energy to result in 
more than a mild case of PTS. As mentioned previously and in relation 
to TTS, the likely consequences to the health of an individual that 
incurs PTS can range from mild to more serious, depending upon the 
degree of PTS and the frequency band it is in, and many animals are 
able to compensate for the shift, although it may include energetic 
costs.
    As discussed previously, marine mammals (especially beaked whales) 
could potentially respond to MFAS at a received level lower than the 
injury threshold in a manner that indirectly results in the animals 
stranding. The exact mechanism of this potential response, behavioral 
or physiological, is not known. When naval exercises have been 
associated with strandings in the past, it has typically been when 
three or more vessels are operating simultaneously, in the presence of 
a strong surface duct, and in areas of constricted channels, semi-
enclosed areas, and/or steep bathymetry. A combination of these 
environmental and operational parameters is not present in the NWTT 
action. When this is combined with consideration of the number of hours 
of active sonar training that will be conducted and the nature of the 
exercises--which do not typically include the use of multiple hull-
mounted sonar sources--we believe that the probability is small that 
this will occur. Furthermore, given that there has never been a 
stranding in the Study Area associated with sonar use and based on the 
number of occurrences where strandings have been definitively 
associated with military sonar versus the number of hours of active 
sonar training that have been conducted, we believe that the 
probability is small that this will occur as a result of the Navy's 
proposed training and testing activities. Lastly, an active sonar 
shutdown protocol for strandings involving live animals milling in the 
water minimizes the chances that these types of events turn into 
mortalities.
    As stated previously, there have been no recorded Navy vessel 
strikes of any marine mammals during training or testing in the NWTT 
Study Area to date, nor were takes by injury or mortality resulting 
from vessel strike predicted in the Navy's acoustic effects analysis.

Species/Group Specific Analysis

    In the discussions below, the ``acoustic analysis'' refers to the 
Navy's model results and post-model analysis. The Navy performed a 
quantitative analysis to estimate the number of marine mammals that 
could be harassed by acoustic sources or explosives used during Navy 
training and testing activities. Inputs to the quantitative analysis 
included marine mammal density estimates; marine mammal depth 
occurrence distributions; oceanographic and environmental data; marine 
mammal hearing data; and criteria and thresholds for levels of 
potential effects. Marine mammal densities used in the model may 
overestimate actual densities when species data is limited and for 
species with seasonal migrations (e.g., humpbacks, blue whales, sei 
whales, gray whales). The quantitative analysis consists of computer 
modeled estimates and a post-model analysis (which considers the 
potential for avoidance and highly effective mitigation to prevent 
Level A harassments) to determine the number of potential harassments. 
The model calculates sound energy propagation from sonars, other active 
acoustic sources, and explosives during naval activities; the sound or 
impulse received by animat dosimeters representing marine mammals 
distributed in the area around the modeled activity; and whether the 
sound or impulse received by a marine mammal exceeds the thresholds for 
effects. The model estimates are then

[[Page 31801]]

further analyzed and adjusted to consider animal avoidance and 
implementation of mitigation measures, resulting in final estimates of 
effects due to Navy training and testing.
    Although this more complex computer modeling approach accounts for 
various environmental factors affecting acoustic propagation, the 
current software tools do not consider the likelihood that a marine 
mammal would attempt to avoid repeated exposures to a sound or avoid an 
area of intense activity where a training or testing event may be 
focused. Additionally, the software tools do not consider the 
implementation of mitigation (e.g., stopping sonar transmissions when a 
marine mammal is within a certain distance of a ship or range clearance 
prior to detonations). In both of these situations, naval activities 
are modeled as though an activity would occur regardless of proximity 
to marine mammals and without any horizontal movement by the animal 
away from the sound source or human activities (e.g., without 
accounting for likely animal avoidance). The initial model results 
overestimate the number of takes (as described previously). The final 
step of the quantitative analysis of acoustic effects is to consider 
the implementation of mitigation and the possibility that marine 
mammals would avoid continued or repeated injurious sound exposures, 
thus, reducing Level A takes. All adjusted effects resulting from 
likely avoidance behaviors and implementation of highly effective 
mitigation are quantified (added) as Level B harassment (TTS) and are 
part of the requested annual effects to marine mammals.
    It is important to note that adjustments to take estimates as a 
result of implemented mitigation were only applied to those events 
having a very high likelihood of detecting marine mammals. It is also 
important to note that the Navy's take estimates represent the total 
number of takes and not the number of individuals taken, as a single 
individual may be taken multiple times over the course of a year. NMFS 
provided input to the Navy on this process and the Navy's qualitative 
analysis is described in detail in Chapter 6 of their LOA application. 
(http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm).
    Predicted harassment of marine mammals from sonar and other active 
acoustic sources and explosions during annual training and testing 
activities are shown in Tables 18-21. The acoustic analysis predicts 
the majority of marine mammal species in the Study Area would not be 
exposed to explosive (impulse) sources associated with training and 
testing activities, which would exceed the current impact thresholds 
(Table 4). Only harbor porpoise, Dall's porpoise, and Northern elephant 
seal are predicted to have exposures that would exceed the current 
impact thresholds for explosives, as presented in the following 
subsections.
    The analysis below may in some cases (e.g., mysticetes, porpoises, 
pinnipeds) address species collectively if they occupy the same 
functional hearing group (i.e., low, mid, and high-frequency cetaceans 
and pinnipeds in water), have similar hearing capabilities, and/or are 
known to generally behaviorally respond similarly to acoustic 
stressors. Where there are meaningful differences between species in 
anticipated individual responses to activities, impact of expected take 
on the population due to differences in population status, or impacts 
on habitat, they will either be described within the section or the 
species will be included as a separate sub-section. See the Brief 
Background on Sound section earlier in this proposed rule for a 
description of marine mammal functional hearing groups as originally 
designated by Southall et al. (2007).
    Mysticetes--The Navy's acoustic analysis predicts that 184 
instances of Level B harassment of mysticete whales may occur in the 
Study Area each year from sonar and other active acoustic stressors 
during training and testing activities. Species-specific Level B take 
estimates are as follows: 57 humpback whales (Central North Pacific and 
California/Oregon/Washington stocks); 11 blue whales (Eastern North 
Pacific stock); 61 fin whales (Northeast Pacific and California/Oregon/
Washington stocks); 2 sei whales (Eastern North Pacific stock); 36 
minke whales (Alaska and California/Oregon/Washington stocks); and 17 
gray whales (Eastern North Pacific and Western North Pacific stocks). 
Based on the distribution information presented in the LOA application, 
it is highly unlikely that North Pacific right whales would be 
encountered in the Study Area during events involving use of sonar and 
other active acoustic sources. The acoustic analysis did not predict 
any takes of North Pacific right whales, and NMFS is not authorizing 
any takes of this species. Of these species, humpback (This species is 
being considered by NMFS for removal or down-listing from the U.S. 
Endangered Species List [NMFS, 2009, 2013a; Bettridge et al. 2015; 
NOAA, 2015b]), blue, fin, and sei whales are listed as endangered under 
the ESA and depleted under the MMPA.
    These exposure estimates represent a limited number of takes 
relative to population estimates for all mysticete stocks in the Study 
Area (Table 9). When the numbers of behavioral takes are compared to 
the estimated stock abundance and if one assumes that each take happens 
to a separate animal, less than 20 percent of each of these stocks 
would be behaviorally harassed during the course of a year. More 
likely, fewer individuals would be taken, but a subset would be taken 
more than one time per year.
    Level B harassment takes are anticipated to be in the form of TTS 
and behavioral reactions and no injurious takes of humpback, blue, fin, 
or sei whales from sonar and other active acoustic stressors or 
explosives are expected. The majority of acoustic effects to mysticetes 
from sonar and other active sound sources during training activities 
would be primarily from anti-submarine warfare events involving surface 
ships and hull mounted sonar. Most Level B harassments to mysticetes 
from sonar would result from received levels less than 158 dB SPL. 
Recovery from a threshold shift (TTS) can take a few minutes to a few 
days (i.e., there is recovery), depending on the severity of the 
initial shift; however, NMFS does not anticipate TTS of a long duration 
or severe degree to occur as a result of exposure to MFAS/HFAS in the 
Study Area. Threshold shifts do not necessarily affect all hearing 
frequencies equally, so some threshold shifts may not interfere with an 
animal's of biologically relevant sounds. Most low-frequency 
(mysticetes) cetaceans observed in studies usually avoided sound 
sources at levels of less than or equal to 160 dB re 1[mu]Pa. 
Mysticetes that are exposed to sonar and other active acoustic sources 
may react by alerting, ignoring the stimulus, changing their behaviors 
or vocalizations, or avoiding the area by swimming away or diving 
(Richardson, 1995; Nowacek, 2007; Southall et al., 2007).
    Specific to U.S. Navy systems using low frequency sound, studies 
were undertaken in 1997-98 pursuant to the Navy's Low Frequency Sound 
Scientific Research Program. These studies found only short-term 
responses to low frequency sound by mysticetes (fin, blue, and 
humpback), including changes in vocal activity and avoidance of the 
source vessel (Clark, 2001; Miller et al., 2000; Croll et al., 2001; 
Fristrup et al., 2003; Nowacek et al., 2007). Baleen whales exposed to 
moderate low-frequency signals demonstrated no variation in foraging 
activity (Croll et al., 2001). Low-frequency signals of the

[[Page 31802]]

Acoustic Thermometry of Ocean Climate sound source were not found to 
affect dive times of humpback whales in Hawaiian waters (Frankel and 
Clark, 2000).
    Specific to mid-frequency sounds, studies by Melc[oacute]n et al. 
(2012) in the Southern California Bight found that the likelihood of 
blue whale low-frequency calling (usually associated with feeding 
behavior) decreased with an increased level of mid-frequency sonar, 
beginning at a SPL of approximately 110-120 dB re 1 [mu]Pa. However, it 
is not known whether the lower rates of calling actually indicated a 
reduction in feeding behavior or social contact since the study used 
data from remotely deployed, passive acoustic monitoring buoys. 
Preliminary results from the 2010-2011 field season of an ongoing 
behavioral response study in Southern California waters indicated that 
in some cases and at low received levels, tagged blue whales responded 
to mid-frequency sonar but that those responses were mild and there was 
a quick return to their baseline activity (Southall et al., 2012b). 
Blue whales responded to a mid-frequency sound source, with a source 
level between 160 and 210 dB re 1 [mu]Pa at 1 m and a received sound 
level up to 160 dB re 1 [mu]Pa, by exhibiting generalized avoidance 
responses and changes to dive behavior during controlled exposure 
experiments (CEE) (Goldbogen et al., 2013). However, reactions were not 
consistent across individuals based on received sound levels alone, and 
likely were the result of a complex interaction between sound exposure 
factors such as proximity to sound source and sound type (mid-frequency 
sonar simulation vs. pseudo-random noise), environmental conditions, 
and behavioral state. Surface feeding whales did not show a change in 
behavior during CEEs, but deep feeding and non-feeding whales showed 
temporary reactions that quickly abated after sound exposure. Distances 
of the sound source from the whales during CEEs were sometimes less 
than a mile. Furthermore, the more dramatic reactions reported by 
Goldbogen et al. (2013) were from non-sonar like signals, a 
pseudorandom noise that could likely have been a novel signal to blue 
whales. The preliminary findings from Goldbogen et al. (2013) and 
Melc[oacute]n et al. (2012) are consistent with the Navy's criteria and 
thresholds for predicting behavioral effects to mysticetes from sonar 
and other active acoustic sources used in the quantitative acoustic 
effects analysis for NWTT. The behavioral response function predicts a 
probability of a substantive behavioral reaction for individuals 
exposed to a received SPL of 120 dB re 1 [mu]Pa or greater, with an 
increasing probability of reaction with increased received level as 
demonstrated in Melc[oacute]n et al. (2012).
    High-frequency systems are not within mysticetes' ideal hearing 
range and it is unlikely that they would cause a significant behavioral 
reaction resulting in takes.
    Overall, the number of predicted behavioral reactions is low and 
occasional behavioral reactions are unlikely to cause long-term 
consequences for individual animals or populations. The implementation 
of mitigation and the sightability of mysticetes (due to their large 
size) reduces the potential for a significant behavioral reaction or a 
threshold shift to occur. Furthermore, there is no designated critical 
habitat for mysticetes in the NWTT Study Area. There are also no known 
specific breeding or calving areas for mysticete species within the 
Study Area. Some biologically-important mysticete feeding and migration 
areas (Northern Puget Sound Feeding Area for gray whales; Northbound 
Migration Phase A for gray whales; Northbound Migration Phase B for 
gray whales; Potential Presence Migration Area for gray whales; 
Northern Washington Feeding Area for humpback whales; Stonewall and 
Heceta Bank Feeding Area for humpback whales; Cape Blanco and Orford 
Reef Feeding Area for gray whale; and Point St. George Feeding Area for 
gray whales) may overlap slightly with the Study Area. However, a 
review of the BIAs for humpback whales and gray whales against areas 
where most acoustic activities are conducted in the Study Area 
(especially those that involve ASW hull-mounted sonar, sonobuoys, and 
use of explosive munitions) identified that there is no spatial 
overlap. The overall risk to species in these areas has been 
preliminarily determined to be low or biologically insignificant, in 
part due to the generally infrequent, temporally and spatially 
variable, and extreme offshore nature of sonar-related activities and 
sound propagation relative to the more coastally distributed 
biologically important areas; the probability that propagated receive 
levels within these areas would be relatively low in terms of 
behavioral criteria (Debich et al., 2014; U.S. Department of the Navy, 
2013d); the likelihood of TTS or PTS sound levels being extremely low; 
and the overall application of Navy mitigation procedures for marine 
mammals sighted within prescribed mitigation zones if such activities 
were to occur in or near these areas. If additional biologically 
important areas are identified by NMFS after finalization of this rule 
and the Navy's NWTT EIS/OEIS, the Navy and NMFS will use the Adaptive 
Management process to assess whether any additional mitigation should 
be considered in those areas. Consequently, the NWTT activities are not 
expected to adversely impact annual rates of recruitment or survival of 
mysticete whales.
    There has never been a vessel strike to a whale during any active 
training or testing activities in the Study Area. A detailed analysis 
of strike data is contained in Chapter 6 (Section 6.7, Estimated Take 
of Large Whales by Navy Vessel Strike) of the LOA application. The Navy 
and NMFS do not anticipate vessel strikes to any marine mammals during 
training or testing activities within the Study Area, nor were takes by 
injury or mortality resulting from vessel strike predicted in the 
Navy's analysis. Therefore, NMFS is not authorizing mysticete takes (by 
injury or mortality) from vessel strikes during the 5-year period of 
the NWTT regulations.
    Sperm Whales--The Navy's acoustic analysis predicts that 159 
instances of Level B harassment of sperm whales (California/Oregon/
Washington stock) may occur in the Study Area each year from sonar or 
other active acoustic stressors during training and testing activities. 
These Level B takes are anticipated to be in the form of TTS and 
behavioral reactions and no injurious takes of sperm whales from sonar 
and other active acoustic stressors or explosives are requested or 
proposed for authorization. Sperm whales have shown resilience to 
acoustic and human disturbance, although they may react to sound 
sources and activities within a few kilometers. Sperm whales that are 
exposed to activities that involve the use of sonar and other active 
acoustic sources may alert, ignore the stimulus, avoid the area by 
swimming away or diving, or display aggressive behavior (Richardson, 
1995; Nowacek, 2007; Southall et al., 2007). Some (but not all) sperm 
whale vocalizations might overlap with the MFAS/HFAS TTS frequency 
range, which could temporarily decrease an animal's sensitivity to the 
calls of conspecifics or returning echolocation signals. However, as 
noted previously, NMFS does not anticipate TTS of a long duration or 
severe degree to occur as a result of exposure to MFAS/HFAS. Recovery 
from a threshold shift (TTS) can take a few minutes to a few days, 
depending on the exposure duration, sound exposure level, and the 
magnitude of the initial shift, with

[[Page 31803]]

larger threshold shifts and longer exposure durations requiring longer 
recovery times (Finneran et al., 2005; Mooney et al., 2009a; Mooney et 
al., 2009b; Finneran and Schlundt, 2010). Large threshold shifts are 
not anticipated for these activities because of the unlikelihood that 
animals will remain within the ensonified area (due to the short 
duration of the majority of exercises, the speed of the vessels, and 
the short distance within which the animal would need to approach the 
sound source) at high levels for the duration necessary to induce 
larger threshold shifts. Threshold shifts do not necessarily affect all 
hearing frequencies equally, so some threshold shifts may not interfere 
with an animal's hearing of biologically relevant sounds. No sperm 
whales are predicted to be exposed to MFAS/HFAS sound levels associated 
with PTS or injury.
    The majority of Level B takes are expected to be in the form of 
mild responses. Relative to the population size (stock abundance 
estimates are shown in Table 9), this activity is anticipated to result 
only in a limited number of Level B harassment takes. When the number 
of behavioral takes is compared to the estimated stock abundance and if 
one assumes that each take happens to a separate animal, less than 17 
percent of the California/Oregon/Washington stock would be behaviorally 
harassed during the course of a year. More likely, fewer individuals 
would be taken, but a subset would be taken more than one time per 
year. Overall, the number of predicted behavioral reactions are 
unlikely to cause long-term consequences for individual animals or 
populations. The NWTT activities are not expected to occur in an area/
time of specific importance for reproductive, feeding, or other known 
critical behaviors for sperm whales. Consequently, the activities are 
not expected to adversely impact annual rates of recruitment or 
survival of sperm whales. Sperm whales are listed as depleted under the 
MMPA and endangered under the ESA; however, there is no designated 
critical habitat in the Study Area.
    There has never been a vessel strike to a sperm whale during any 
active training or testing activities in the Study Area. A detailed 
analysis of strike data is contained in Chapter 6 (Section 6.7, 
Estimated Take of Large Whales by Navy Vessel Strike) of the LOA 
application. The Navy and NMFS do not anticipate vessel strikes to any 
marine mammals during training or testing activities within the Study 
Area, nor were takes by injury or mortality resulting from vessel 
strikes predicted in the Navy's analysis. Therefore, NMFS is not 
authorizing sperm whale takes (by injury or mortality) from vessel 
strikes during the 5-year period of the NWTT regulations.
    Porpoises--The Navy's acoustic analysis predicts that 15,071 
instances of Level B harassment of Dall's porpoises (Alaska and 
California/Oregon/Washington stocks) and 138,225 instances of Level B 
harassment of harbor porpoises (Southeast Alaska, Northern Oregon/
Washington Coast, Northern California/Southern Oregon, and Washington 
Inland Waters stocks) (mainly behavioral reaction) may occur each year 
from sonar and other active acoustic stressors and explosives 
associated with training and testing activities in the Study Area. 
These estimates represent the total number of exposures and not 
necessarily the number of individuals exposed, as a single individual 
may be exposed multiple times over the course of a year. Behavioral 
responses can range from a mild orienting response, or a shifting of 
attention, to flight and panic (Richardson, 1995; Nowacek, 2007; 
Southall et al., 2007).
    Acoustic analysis (factoring in the post-model correction for 
avoidance and mitigation) also predicted that 47 Dall's porpoises and 
45 harbor porpoises might be exposed to sound levels likely to result 
in PTS or injury (Level A harassment) from mainly sonar and other 
active acoustic stressors, and explosives. In the case of all explosive 
exercises, it is worth noting that the amount of explosive and acoustic 
energy entering the water, and therefore the effects on marine mammals, 
may be overestimated, as many explosions actually occur upon impact 
with above-water targets. However, sources such as these were modeled 
as exploding at 1-meter depth. Furthermore, in the case of all 
explosive exercises, the exclusion zones are considerably larger than 
the estimated distance at which an animal would be exposed to injurious 
sounds or pressure waves.
    Animals that do experience hearing loss (TTS or PTS) may have 
reduced ability to detect relevant sounds such as predators, prey, or 
social vocalizations. Some porpoise vocalizations might overlap with 
the MFAS/HFAS TTS frequency range (2-20 kHz). It is worth noting that 
TTS in the range induced by MFAS/HFAS would reduce sensitivity in the 
band that killer whales (a potential predator) click and echolocate in. 
Recovery from a threshold shift (TTS; partial hearing loss) can take a 
few minutes to a few days, depending on the exposure duration, sound 
exposure level, and the magnitude of the initial shift, with larger 
threshold shifts and longer exposure durations requiring longer 
recovery times (Finneran et al., 2005; Mooney et al., 2009a; Mooney et 
al., 2009b; Finneran and Schlundt, 2010). More severe shifts may not 
fully recover and thus would be considered PTS. However, large degrees 
of PTS are not anticipated for these activities because of the 
unlikelihood that animals will remain within the ensonified area (due 
to the short duration of the majority of exercises, the speed of the 
vessels, and the short distance within which the animal would need to 
approach the sound source) at high levels for the duration necessary to 
induce larger threshold shifts. Threshold shifts do not necessarily 
affect all hearing frequencies equally, so some threshold shifts may 
not interfere with an animal hearing biologically relevant sounds. The 
likely consequences to the health of an individual that incurs PTS can 
range from mild to more serious, depending upon the degree of PTS and 
the frequency band it is in, and many animals are able to compensate 
for the shift, although it may include energetic costs. Furthermore, 
likely avoidance of intense activity and sound coupled with mitigation 
measures would further reduce the potential for severe PTS exposures to 
occur. If a marine mammal is able to approach a surface vessel within 
the distance necessary to incur PTS, the likely speed of the vessel 
(nominal 10-15 knots) would make it very difficult for the animal to 
remain in range long enough to accumulate enough energy to result in 
more than a mild case of PTS.
    Harbor porpoises have been observed to be especially sensitive to 
human activity (Tyack et al., 2011; Pirotta et al., 2012). The 
information currently available regarding harbor porpoises suggests a 
very low threshold level of response for both captive (Kastelein et 
al., 2000; Kastelein et al., 2005) and wild (Johnston, 2002) animals. 
Southall et al. (2007) concluded that harbor porpoises are likely 
sensitive to a wide range of anthropogenic sounds at low received 
levels (~90 to 120 dB). Research and observations of harbor porpoises 
for other locations show that this small species is wary of human 
activity and will display profound avoidance behavior for anthropogenic 
sound sources in many situations at levels down to 120 dB re 1 [mu]Pa 
(Southall, 2007). Harbor porpoises routinely avoid and swim away from 
large motorized vessels (Barlow et al., 1988; Evans et al., 1994; Palka 
and Hammond, 2001; Polacheck and

[[Page 31804]]

Thorpe, 1990). The vaquita, which is closely related to the harbor 
porpoise in the Study Area, appears to avoid large vessels at about 
2,995 ft. (913 m) (Jaramillo-Legorreta et al., 1999). The assumption is 
that the harbor porpoise would respond similarly to large Navy vessels, 
possibly prior to commencement of sonar or explosive activity (i.e., 
pre-activity avoidance). Harbor porpoises may startle and temporarily 
leave the immediate area of the training or testing until after the 
event ends. Since a large proportion of training and testing activities 
occur within harbor porpoise habitat in the Study Area and given their 
very low behavioral threshold, predicted effects are more likely than 
with most other odontocetes, especially at closer ranges (within a few 
kilometers). Since this species is typically found in nearshore and 
inshore habitats, resident animals that are present throughout the 
Study Area could receive multiple exposures over a short period of time 
year round. As mentioned earlier in the Analysis and Negligible Impact 
Determination section, we anticipate more severe effects from takes 
when animals are exposed to higher received levels. Animals that do not 
exhibit a significant behavioral reaction would likely recover from any 
incurred costs, which reduces the likelihood of long-term consequences, 
such as reduced fitness, for the individual or population.
    Stock abundance estimates for Dall's and harbor porpoises are shown 
in Table 9. When the numbers of takes for Dall's porpoise are compared 
to the estimated stock abundances and if one assumes that each take 
happens to a separate animal, approximately 30 percent of the Alaska 
stock and less than 2 percent of the California/Oregon/Washington stock 
would be harassed (behaviorally) during the course of a year. More 
likely, fewer individuals are harassed, but a subset are harassed more 
than one time during the course of the year. The number of harbor 
porpoises--in particular, Northern Oregon/Washington Coast and Northern 
California/Southern Oregon stocks--behaviorally harassed by exposure to 
MFAS/HFAS in the Study Area is higher than the other species (and, in 
fact, suggests that every member of the stock could potentially be 
taken by Level B harassment multiple times, although it is more likely 
that fewer individuals are harassed but a subset are harassed more than 
one time during the course of the year) because of the low Level B 
harassment threshold (we assume for the purpose of estimating take that 
all harbor porpoises exposed to 120 dB or higher MFAS/HFAS will be 
taken by Level B behavioral harassment), which essentially makes the 
ensonified area of effects significantly larger than for the other 
species. However, the fact that the threshold is a step function and 
not a curve (and assuming uniform density) means that the vast majority 
of the takes occur in the very lowest levels that exceed the threshold 
(it is estimated that approximately 80 percent of the takes are from 
exposures to 120 dB to 126 dB), which means that anticipated behavioral 
effects are not expected to be severe (e.g., temporary avoidance). As 
mentioned above, an animal's exposure to a higher received level is 
more likely to result in a behavioral response that is more likely to 
adversely affect the health of an animal. ASW training and testing 
exercises using MFAS/HFAS generally last for 2-16 hours, and may have 
intervals of non-activity in between. In addition, the Navy does not 
typically conduct successive MTEs (no MTEs are proposed for NWTT) or 
other ASW exercises in the same locations. Given the average length of 
ASW exercises (times of continuous sonar use) and typical vessel speed, 
combined with the fact that the majority of the harbor porpoises in the 
Study Area would not likely remain in an area for successive days, it 
is unlikely that an animal would be exposed to MFAS/HFAS at levels 
likely to result in a substantive response (e.g., interruption of 
feeding) that would then be carried on for more than one day or on 
successive days. Thompson et al. (2013) showed that seismic surveys 
conducted over a 10-day period in the North Sea did not result in the 
broad-scale displacement of harbor porpoises away from preferred 
habitat. The harbor porpoises were observed to leave the area at the 
onset of survey, but returned within a few hours, and the overall 
response of the porpoises decreased over the 10-day period.
    The harbor porpoise is a common species in the nearshore coastal 
waters of the Study Area year-round (Barlow, 1988; Green et al., 1992; 
Osmek et al., 1996, 1998; Forney and Barlow, 1998; Carretta et al., 
2009). Since 1999, Puget Sound Ambient Monitoring Program data and 
stranding data documented increasing numbers of harbor porpoise in 
Puget Sound, indicating that the species may be returning to the area 
(Nysewander, 2008; Washington Department of Fish and Wildlife, 2008; 
Jeffries, 2013a). Sightings in northern Hood Canal (north of the Hood 
Canal Bridge) have increased in recent years (Calambokidis, 2010). 
Harbor porpoise continue to inhabit the waters of Hood Canal (including 
Dabob Bay), which has for decades served as the location for training 
and testing events using sonar and other active acoustic sources.
    Considering the information above, the predicted effects to Dall's 
and harbor porpoises are unlikely to cause long-term consequences for 
individual animals or the population. The NWTT activities are not 
expected to occur in an area/time of specific importance for 
reproductive, feeding, or other known critical behaviors for Dall's and 
harbor porpoises. Pacific stocks of Dall's and harbor porpoises are not 
listed as depleted under the MMPA. Consequently, the activities are not 
expected to adversely impact annual rates of recruitment or survival of 
porpoises.
    Pygmy and Dwarf Sperm Whales (Kogia spp.)--Due to the difficulty in 
differentiating these two species at sea, an estimate of the effects on 
the two species have been combined. The Navy's acoustic analysis 
predicts that 179 instances of Level B harassment (TTS and behavioral 
reaction) of the California/Oregon/Washington stock of Kogia spp. may 
occur each year from sonar and other active acoustic stressors 
associated with training and testing activities in the Study Area. The 
Navy's acoustics analysis (factoring in the post-model correction for 
avoidance and mitigation) also indicates that 1 exposure of Kogia to 
sound levels from non-impulsive acoustic sources likely to result in 
level A harassment (PTS) may occur during testing activities in the 
Study Area. Stock abundance estimates for California/Oregon/Washington 
stocks of Kogia spp. are shown in Table 9. Relative to population size 
these represent only a limited number of takes if one assumes that each 
take happens to a separate animal. More likely, fewer individuals would 
be taken, but a subset would be taken more than one time per year.
    Recovery from a threshold shift (TTS; partial hearing loss) can 
take a few minutes to a few days, depending on the exposure duration, 
sound exposure level, and the magnitude of the initial shift, with 
larger threshold shifts and longer exposure durations requiring longer 
recovery times (Finneran et al., 2005; Mooney et al., 2009a; Mooney et 
al., 2009b; Finneran and Schlundt, 2010). PTS would not fully recover. 
However, large degrees of PTS are not anticipated for these activities 
because of the unlikelihood that animals will remain within the 
ensonified area (due to the short duration of the majority of 
exercises, the speed of the vessels, and the short distance within 
which the

[[Page 31805]]

animal would need to approach the sound source) at high levels for the 
duration necessary to induce larger threshold shifts. Threshold shifts 
do not necessarily affect all hearing frequencies equally, so some 
threshold shifts may not interfere with an animal hearing biologically 
relevant sounds. The likely consequences to the health of an individual 
that incurs PTS can range from mild to more serious, depending upon the 
degree of PTS and the frequency band it is in, and many animals are 
able to compensate for the shift, although it may include energetic 
costs. Furthermore, likely avoidance of intense activity and sound 
coupled with mitigation measures would further reduce the potential for 
severe PTS exposures to occur. If a marine mammal is able to approach a 
surface vessel within the distance necessary to incur PTS, the likely 
speed of the vessel (nominal 10-15 knots) would make it very difficult 
for the animal to remain in range long enough to accumulate enough 
energy to result in more than a mild case of PTS.
    Some Kogia spp. vocalizations might overlap with the MFAS/HFAS TTS 
frequency range (2-20 kHz), but the limited information for Kogia spp. 
indicates that their clicks are at a much higher frequency and that 
their maximum hearing sensitivity is between 90 and 150 kHz. It is 
worth noting that TTS in the range induced by MFAS would reduce 
sensitivity in the band that killer whales (a potential predator) click 
and echolocate in. However, as noted previously, NMFS does not 
anticipate TTS of a long duration or severe degree to occur as a result 
of exposure to MFA/HFAS.
    Research and observations on Kogia spp. are limited. These species 
tend to avoid human activity and presumably anthropogenic sounds. Pygmy 
and dwarf sperm whales may startle and leave the immediate area of 
activity, reducing potential impacts. Pygmy and dwarf sperm whales have 
been observed to react negatively to survey vessels or low altitude 
aircraft by quick diving and other avoidance maneuvers, and none were 
observed to approach vessels (Wursig et al., 1998). Based on their 
tendency to avoid acoustic stressors (e.g., quick diving and other 
vertical avoidance maneuvers) coupled with the short duration and 
intermittent nature (e.g., sonar pings during ASW activities occur 
about every 50 seconds) of the majority of training and testing 
exercises and the speed of the Navy vessels involved, it is unlikely 
that animals would receive multiple exposures over a short period of 
time, allowing animals to recover lost resources (e.g., food) or 
opportunities (e.g., mating).
    The predicted effects to Kogia spp. are expected to be temporary 
and unlikely to cause long-term consequences for individual animals or 
populations. The NWTT activities are not expected to occur in an area/
time of specific importance for reproductive, feeding, or other known 
critical behaviors. Pacific stocks of Kogia are not depleted under the 
MMPA. Consequently, the activities are not expected to adversely impact 
annual rates of recruitment or survival of pygmy and dwarf sperm 
whales.
    Beaked Whales--The Navy's acoustic analysis predicts that the 
following numbers of Level B harassment of beaked whales may occur 
annually from sonar and other active acoustic stressors associated with 
training and testing activities in the Study Area: 665 Baird's beaked 
whales (California/Oregon/Washington and Alaska stocks), 459 Cuvier's 
beaked whales (California/Oregon/Washington and Alaska stocks), and 
1,616 Mesoplodon beaked whales (California/Oregon/Washington stock). 
These estimates represent the total number of exposures and not 
necessarily the number of individuals exposed, as a single individual 
may be exposed multiple times over the course of a year. These takes 
are anticipated to be in the form of behavioral harassment (TTS and 
behavioral reaction) and no injurious takes of beaked whales from 
active acoustic stressors or explosives are requested or proposed. 
Stock abundance estimates for beaked whales in the Study Area are shown 
in Table 9. When the numbers of behavioral takes are compared to the 
estimated stock abundances and if one assumes that each take happens to 
a separate animal, less than 7 percent of the California/Oregon/
Washington stock of Cuvier's beaked whale would be behaviorally 
harassed during the course of a year. Virtually all of the Baird's and 
Mesoplodon beaked whale stocks (California/Oregon/Washington) would 
potentially be behaviorally harassed each year, although it is more 
likely that fewer individuals would be harassed but a subset would be 
harassed more than one time during the course of the year. As is the 
case with harbor porpoises, beaked whales have been shown to be 
particularly sensitive to sound and therefore have been assigned a 
lower harassment threshold based on observations of wild animals by 
McCarthy et al. (2011) and Tyack et al. (2011). The fact that the Level 
B harassment threshold is a step function (The Navy has adopted an 
unweighted 140 dB re 1 [micro]Pa SPL threshold for significant 
behavioral effects for all beaked whales) and not a curve (and assuming 
uniform density) means that the vast majority of the takes occur in the 
very lowest levels that exceed the threshold (it is estimated that 
approximately 80 percent of the takes are from exposures to 140 dB to 
146 dB), which means that the anticipated effects for the majority of 
exposures are not expected to be severe (As mentioned above, an 
animal's exposure to a higher received level is more likely to result 
in a behavioral response that is more likely to adversely affect the 
health of an animal). Further, Moretti et al. (2014) recently derived 
an empirical risk function for Blainville's beaked whale that predicts 
there is a 0.5 probability of disturbance at a received level of 150 dB 
(CI: 144-155), suggesting that in some cases the current Navy step 
function may over-estimate the effects of an activity using sonar on 
beaked whales. Irrespective of the Moretti et al. (2014) risk function, 
NMFS' analysis assumes that all of the beaked whale Level B takes that 
are proposed for authorization will occur, and we base our negligible 
impact determination, in part, on the fact that these exposures would 
mainly occur at the very lowest end of the 140-dB behavioral harassment 
threshold where behavioral effects are expected to be much less severe 
and generally temporary in nature.
    Behavioral responses can range from a mild orienting response, or a 
shifting of attention, to flight and panic (Richardson, 1995; Nowacek, 
2007; Southall et al., 2007). Research has also shown that beaked 
whales are especially sensitive to the presence of human activity 
(Tyack et al., 2011; Pirotta et al., 2012). Beaked whales have been 
documented to exhibit avoidance of human activity or respond to vessel 
presence (Pirotta et al., 2012). Beaked whales were observed to react 
negatively to survey vessels or low altitude aircraft by quick diving 
and other avoidance maneuvers, and none were observed to approach 
vessels (Wursig et al., 1998). Some beaked whale vocalizations may 
overlap with the MFAS/HFAS TTS frequency range (2-20 kHz); however, as 
noted above, NMFS does not anticipate TTS of a serious degree or 
extended duration to occur as a result of exposure to MFA/HFAS. 
Recovery from a threshold shift (TTS) can take a few minutes to a few 
days, depending on the exposure duration, sound exposure level, and the 
magnitude of the initial shift, with larger threshold shifts and longer 
exposure durations requiring longer recovery times (Finneran et al., 
2005; Mooney et al., 2009a; Mooney et al.,

[[Page 31806]]

2009b; Finneran and Schlundt, 2010). Large threshold shifts are not 
anticipated for these activities because of the unlikelihood that 
animals will remain within the ensonified area (due to the short 
duration of the majority of exercises, the speed of the vessels, and 
the short distance within which the animal would need to approach the 
sound source) at high levels for the duration necessary to induce 
larger threshold shifts. Threshold shifts do not necessarily affect all 
hearing frequencies equally, so some threshold shifts may not interfere 
with an animal's hearing of biologically relevant sounds.
    It has been speculated for some time that beaked whales might have 
unusual sensitivities to sonar sound due to their likelihood of 
stranding in conjunction with mid-frequency sonar use. Research and 
observations show that if beaked whales are exposed to sonar or other 
active acoustic sources they may startle, break off feeding dives, and 
avoid the area of the sound source to levels of 157 dB re 1 [mu]Pa, or 
below (McCarthy et al., 2011). Acoustic monitoring during actual sonar 
exercises revealed some beaked whales continuing to forage at levels up 
to 157 dB re 1 [mu]Pa (Tyack et al. 2011). Stimpert et al. (2014) 
tagged a Baird's beaked whale, which was subsequently exposed to 
simulated mid-frequency sonar. Changes in the animal's dive behavior 
and locomotion were observed when received level reached 127 dB re 1 
[mu]Pa. Manzano-Roth et al. (2013) found that for beaked whale dives 
that continued to occur during MFAS activity, differences from normal 
dive profiles and click rates were not detected with estimated received 
levels up to 137 dB re 1 [mu]Pa while the animals were at depth during 
their dives. In research done at the Navy's fixed tracking range in the 
Bahamas, animals were observed to leave the immediate area of the anti-
submarine warfare training exercise (avoiding the sonar acoustic 
footprint at a distance where the received level was ``around 140 dB'' 
SPL, according to Tyack et al. [2011]) but return within a few days 
after the event ended (Claridge and Durban, 2009; Moretti et al., 2009, 
2010; Tyack et al., 2010, 2011; McCarthy et al., 2011). Tyack et al. 
(2011) report that, in reaction to sonar playbacks, most beaked whales 
stopped echolocating, made long slow ascent to the surface, and moved 
away from the sound. A similar behavioral response study conducted in 
Southern California waters during the 2010-2011 field season found that 
Cuvier's beaked whales exposed to MFAS displayed behavior ranging from 
initial orientation changes to avoidance responses characterized by 
energetic fluking and swimming away from the source (DeRuiter et al., 
2013b). However, the authors did not detect similar responses to 
incidental exposure to distant naval sonar exercises at comparable 
received levels, indicating that context of the exposures (e.g., source 
proximity, controlled source ramp-up) may have been a significant 
factor. The study itself found the results inconclusive and meriting 
further investigation. Cuvier's beaked whale responses suggested 
particular sensitivity to sound exposure as consistent with results for 
Blainville's beaked whale. Populations of beaked whales and other 
odontocetes on the Bahamas and other Navy fixed ranges that have been 
operating for decades, appear to be stable. Behavioral reactions 
(avoidance of the area of Navy activity) seem likely in most cases if 
beaked whales are exposed to anti-submarine sonar within a few tens of 
kilometers, especially for prolonged periods (a few hours or more) 
since this is one of the most sensitive marine mammal groups to 
anthropogenic sound of any species or group studied to date and 
research indicates beaked whales will leave an area where anthropogenic 
sound is present (Tyack et al., 2011; De Ruiter et al., 2013; Manzano-
Roth et al., 2013; Moretti et al., 2014). Research involving tagged 
Cuvier's beaked whales in the SOCAL Range Complex reported on by 
Falcone and Schorr (2012, 2014) indicates year-round prolonged use of 
the Navy's training and testing area by these beaked whales and has 
documented movements in excess of hundreds of kilometers by some of 
those animals. Given that some of these animals may routinely move 
hundreds of kilometers as part of their normal pattern, leaving an area 
where sonar or other anthropogenic sound is present may have little, if 
any, cost to such an animal. Photo identification studies in the SOCAL 
Range Complex, a Navy range that is utilized for training and testing 
more frequently than the NWTT Study Area, have identified approximately 
100 individual Cuvier's beaked whale individuals with 40 percent having 
been seen in one or more prior years, with re-sightings up to 7 years 
apart (Falcone and Schorr, 2014). These results indicate long-term 
residency by individuals in an intensively used Navy training and 
testing area, which may also suggest a lack of long-term consequences 
as a result of exposure to Navy training and testing activities. 
Finally, results from passive acoustic monitoring estimated regional 
Cuvier's beaked whale densities were higher than indicated by the 
NMFS's broad scale visual surveys for the U.S. west coast (Hildebrand 
and McDonald, 2009).
    Based on the findings above, it is clear that the Navy's long-term 
ongoing use of sonar and other active acoustic sources has not 
precluded beaked whales from also continuing to inhabit those areas. In 
summary, based on the best available science, the Navy and NMFS believe 
that beaked whales that exhibit a significant TTS or behavioral 
reaction due to sonar and other active acoustic testing activities 
would generally not have long-term consequences for individuals or 
populations. Claridge (2013) speculates that sonar use in a Bahamas 
range could have ``a possible population-level effect'' on beaked 
whales based on lower abundance in comparison to control sites. 
However, the study suffers from several shortcomings and incorrectly 
assumes that the Navy range and control sites were identical. The 
author also acknowledged that ``information currently available cannot 
provide a quantitative answer to whether frequent sonar use at [the 
Bahamas range] is causing stress to resident beaked whales,'' and 
cautioned that the outcome of ongoing studies ``is a critical component 
to understanding if there are population-level effects.'' Moore and 
Barlow (2013) have noted a decline in beaked whale populations in a 
broad area of the Pacific Ocean area out to 300 nm from the coast and 
extending from the Canadian-U.S. border to the tip of Baja Mexico. 
There are scientific caveats and limitations to the data used for that 
analysis, as well as oceanographic and species assemblage changes on 
the U.S. Pacific coast not thoroughly addressed. Interestingly, 
however, in the small portion of that area overlapping the Navy's SOCAL 
Range Complex, long-term residency by individual Cuvier's beaked whales 
and higher densities provide indications that the proposed decline 
noted elsewhere is not apparent where for decades the Navy has been 
intensively training and testing with sonar and other systems.
    NMFS also considered New et al. (2013) and their mathematical model 
simulating a functional link between foraging energetics and 
requirements for survival and reproduction for 21 species of beaked 
whales. However, NMFS concluded that New et al. (2013) model lacks 
critical data and accurate inputs necessary to form valid conclusions 
specifically about impacts of anthropogenic sound from Navy activities 
on beaked whale populations. The study itself notes the need for 
``future research,'' identifies ``key data

[[Page 31807]]

needs'' relating to input parameters that ``particularly affected'' the 
model results, and states only that the use of the model ``in 
combination with more detailed research'' could help predict the 
effects of management actions on beaked whale species. In short, 
information is not currently available to specifically support the use 
of this model in a project-specific evaluation of the effects of navy 
activities on the impacted beaked whale species in NWTT.
    No beaked whales are predicted in the acoustic analysis to be 
exposed to sound levels associated with PTS, other injury, or 
mortality. After decades of the Navy conducting similar activities in 
the NWTT Study Area without incident, NMFS does not expect strandings, 
injury, or mortality of beaked whales to occur as a result of training 
and testing activities. Additionally, through the MMPA process (which 
allows for adaptive management), NMFS and the Navy will determine the 
appropriate way to proceed in the event that a causal relationship were 
to be found between Navy activities and a future stranding.
    The NWTT training and testing activities are not expected to occur 
in an area/time of specific importance for reproductive, feeding, or 
other known critical behaviors for beaked whales. Although no areas of 
specific importance for reproduction or feeding of beaked whales have 
been identified in the Study Area, beaked whales are generally found in 
deep waters over the continental slope, oceanic seamounts, and areas 
with submarine escarpments (very seldom over the continental shelf). 
None of the Pacific stocks for beaked whales species found in the Study 
Area are depleted under the MMPA. Consequently, the activities are not 
expected to adversely impact annual rates of recruitment or survival of 
beaked whales.
    Dolphins and Small Whales--The Navy's acoustic analysis predicts 
the following numbers of Level B harassment of the associated species 
of delphinids (dolphins and small whales, excluding killer whales) may 
occur each year from sonar and other active acoustic sources during 
training and testing activities in the Study Area: 2,362 short-beaked 
common dolphins (California/Oregon/Washington stock); 36 striped 
dolphins (California/Oregon/Washington stock); 8,354 Pacific white-
sided dolphins (California/Oregon/Washington and North Pacific stocks); 
3,370 Northern right whale dolphins (California/Oregon/Washington 
stock); and 1,811 Risso's dolphins (California/Oregon/Washington 
stock). Based on the distribution information presented in the LOA 
application, it is highly unlikely that short-finned pilot whales or 
common bottlenose dolphins would be encountered in the Study Area. The 
acoustic analysis did not predict any takes of short-finned pilot 
whales or bottlenose dolphins and NMFS is not authorizing any takes of 
these species. Relative to delphinid population sizes (stock abundance 
estimates are shown in Table 9), these activities are anticipated to 
generally result only in a limited number of level B harassment takes. 
When the numbers of behavioral takes are compared to the estimated 
stock abundance and if one assumes that each take happens to a separate 
animal, less than 30 percent of the California/Oregon/Washington stock 
of Risso's dolphin; less than 30 percent of the California/Oregon/
Washington stock and less than 0.02 percent of the North Pacific stock 
of pacific white-sided dolphin; less than 28 percent of the California/
Oregon/Washington stock of northern right whale dolphin; less than 0.6 
percent of the California/Oregon/Washington stock of short-beaked 
common dolphin; and less than 0.4 percent of the California/Oregon/
Washington stock of striped dolphin would be behaviorally harassed 
during the course of a year. More likely, slightly fewer individuals 
are harassed, but a subset are harassed more than one time during the 
course of the year.
    All of these takes are anticipated to be in the form of behavioral 
harassment (TTS and behavioral reaction) and no injurious takes of 
delphinids from sonar and other active acoustic stressors or explosives 
are requested or proposed for authorization. Further, the majority of 
takes are anticipated to be by behavioral harassment in the form of 
mild responses. Behavioral responses can range from a mild orienting 
response, or a shifting of attention, to flight and panic (Richardson, 
1995; Nowacek, 2007; Southall et al., 2007). Delphinid species 
generally travel in large pods and should be visible from a distance in 
order to implement mitigation measures and reduce potential impacts. 
Many of the recorded delphinid vocalizations overlap with the MFAS/HFAS 
TTS frequency range (2-20 kHz); however, as noted above, NMFS does not 
anticipate TTS of a serious degree or extended duration to occur as a 
result of exposure to MFAS/HFAS. Recovery from a threshold shift (TTS) 
can take a few minutes to a few days, depending on the exposure 
duration, sound exposure level, and the magnitude of the initial shift, 
with larger threshold shifts and longer exposure durations requiring 
longer recovery times (Finneran et al., 2005; Mooney et al., 2009a; 
Mooney et al., 2009b; Finneran and Schlundt, 2010). Large threshold 
shifts are not anticipated for these activities because of the 
unlikelihood that animals will remain within the ensonified area (due 
to the short duration of the majority of exercises, the speed of the 
vessels, and the short distance within which the animal would need to 
approach the sound source) at high levels for the duration necessary to 
induce larger threshold shifts. Threshold shifts do not necessarily 
affect all hearing frequencies equally, so some threshold shifts may 
not interfere with an animal's hearing of biologically relevant sounds.
    The predicted effects to delphinids are unlikely to cause long-term 
consequences for individual animals or populations. The NWTT activities 
are not expected to occur in an area/time of specific importance for 
reproductive, feeding, or other known critical behaviors for 
delphinids. Pacific stocks of delphinid species found in the Study Area 
are not depleted under the MMPA. Consequently, the activities are not 
expected to adversely impact annual rates of recruitment or survival of 
delphinid species.
    Killer Whales--The Navy's acoustic analysis predicts 250 instances 
of Level B harassment of killer whales (Alaska Resident, Northern 
Resident, West Coast Transient, Eastern North Pacific Offshore, and 
Eastern North Pacific Southern Resident stocks), including 2 Level B 
takes of southern resident killer whales, from sonar and other active 
acoustic sources during annual training activities in the Study Area. 
Relative to population sizes (killer whale stock abundance estimates 
are shown in Table 9), these activities are anticipated to generally 
result only in a limited number of level B harassment takes. When the 
numbers of behavioral takes are compared to the estimated stock 
abundance and if one assumes that each take happens to a separate 
animal, less than 15 percent of all killer whale stocks--and 2 percent 
of the Southern Resident stock of killer whale--would be behaviorally 
harassed during the course of a year. More likely, slightly fewer 
individuals would harassed, but a subset would be harassed more than 
one time during the course of the year.
    All of these takes are anticipated to be in the form of behavioral 
harassment (TTS and behavioral reaction) and no injurious takes of 
killer whales from sonar and other active acoustic stressors or 
explosives are requested or proposed for authorization. Further, the 
majority of takes are anticipated to be by behavioral harassment in the 
form of

[[Page 31808]]

mild responses. Behavioral responses can range from a mild orienting 
response, or a shifting of attention, to flight and panic (Richardson, 
1995; Nowacek, 2007; Southall et al., 2007). Killer whales generally 
travel in pods and should be visible from a distance in order to 
implement mitigation measures and reduce potential impacts. Recovery 
from a threshold shift (TTS) can take a few minutes to a few days, 
depending on the exposure duration, sound exposure level, and the 
magnitude of the initial shift, with larger threshold shifts and longer 
exposure durations requiring longer recovery times (Finneran et al., 
2005; Mooney et al., 2009a; Mooney et al., 2009b; Finneran and 
Schlundt, 2010). Large threshold shifts are not anticipated for these 
activities because of the unlikelihood that animals will remain within 
the ensonified area (due to the short duration of the majority of 
exercises, the speed of the vessels, and the short distance within 
which the animal would need to approach the sound source) at high 
levels for the duration necessary to induce larger threshold shifts. 
Threshold shifts do not necessarily affect all hearing frequencies 
equally, so some threshold shifts may not interfere with an animal's 
hearing of biologically relevant sounds.
    The southern resident killer whale is the only ESA-listed marine 
mammal species with designated critical habitat located in the NWTT 
Study Area (NMFS, 2006). The majority of the Navy's proposed training 
and testing activities would, however, not occur in the southern 
resident killer whale's designated critical habitat (NMFS, 2006). For 
all substressors that would occur within the critical habitat, those 
training and testing activities are not expected to impact the 
identified primary constituent elements of that habitat and therefore 
would have no effect on that critical habitat. Furthermore, the 
majority of testing events would occur in Hood Canal, where southern 
resident killer whales are not believed to be present, while the 
majority of training activities would occur in the offshore portions of 
the Study Area where they are only present briefly during their annual 
migration period. Effects to designated critical habitat will be fully 
analyzed in the Navy's and NMFS' internal ESA Section 7 consultations 
for NWTT.
    The whale's size and detectability makes it unlikely that these 
animals would be exposed to the higher energy or pressure expected to 
result in more severe effects. As stated above, the vocalizations of 
killer whales fall directly into the frequency range in which TTS would 
be incurred from the MFAS sources used during ASW exercises; however, 
the Navy is conducting ASW exercises mainly in the Offshore Area while 
killer whales are predominantly situated in the Inland Waters Area. 
Both behavioral and auditory brainstem response techniques indicate 
killer whales can hear a frequency range of 1 to 100 kHz and are most 
sensitive at 20 kHz. This is one the lowest maximum-sensitivity 
frequencies known among toothed whales (Szymanski et al., 1999).
    The NWTT training and testing activities are generally not expected 
to occur in an area/time of specific importance for reproductive, 
feeding, or other known critical behaviors for killer whales. 
Consequently, the activities are not expected to adversely impact 
annual rates of recruitment or survival of killer whale species and 
will therefore not result in population-level impacts.
    Pinnipeds--The Navy's acoustic analysis predicts that the following 
numbers of Level B harassment (TTS and behavioral reaction) may occur 
annually from sonar and other active acoustic stressors and sound or 
energy from explosions associated with training and testing activities 
in the Study Area: 908 Steller sea lions (Eastern U.S. stock); 10 
Guadalupe fur seals (San Miguel Island stock); 2,887 California sea 
lions (U.S. stock); 4,389 northern fur seals (Eastern Pacific and 
California stocks); 2,596 northern elephant seals (California Breeding 
stock); and 63,475 harbor seals (Southeast Alaska [Clarence Strait], 
Oregon/Washington Coast, Washington Northern Inland Waters, Southern 
Puget Sound, and Hood Canal stocks). These estimates represents the 
total number of exposures and not necessarily the number of individuals 
exposed, as a single individual may be exposed multiple times over the 
course of a year. Northern elephant seals are the only pinnipeds 
predicted to incur takes (one Level B take) from exposure to 
explosives. The acoustic analysis (factoring in the post-model 
correction for avoidance and mitigation) also indicates that 2 Northern 
elephant seals and 92 harbor seals would be exposed to sound levels 
likely to result in Level A harassment (PTS) from sonar or other active 
acoustic sources.
    Research has demonstrated that for pinnipeds, as for other mammals, 
recovery from a hearing threshold shift (i.e., TTS; temporary partial 
hearing loss) can take a few minutes to a few days depending on the 
severity of the initial shift. More severe shifts may not fully recover 
and thus would be considered PTS. However, large degrees of PTS are not 
anticipated for these activities because of the unlikelihood that 
animals will remain within the ensonified area (due to the short 
duration of the majority of exercises, the speed of the vessels, and 
the short distance within which the animal would need to approach the 
sound source) at high levels for the duration necessary to induce 
larger threshold shifts. Threshold shifts do not necessarily affect all 
hearing frequencies equally, so threshold shifts may not necessarily 
interfere with an animal's ability to hear biologically relevant 
sounds. The likely consequences to the health of an individual that 
incurs PTS can range from mild to more serious, depending upon the 
degree of PTS and the frequency band it is in, and many animals are 
able to compensate for the shift, although it may include energetic 
costs. Likely avoidance of intense activity and sound coupled with 
mitigation measures would further reduce the potential for severe PTS 
exposures to occur. If a marine mammal is able to approach a surface 
vessel within the distance necessary to incur PTS, the likely speed of 
the vessel (nominal 10-15 knots) would make it very difficult for the 
animal to remain in range long enough to accumulate enough energy to 
result in more than a mild case of PTS.
    Research and observations show that pinnipeds in the water may be 
tolerant of anthropogenic noise and activity (a review of behavioral 
reactions by pinnipeds to impulsive and non-impulsive noise can be 
found in Richardson et al., 1995 and Southall et al., 2007). Available 
data, though limited, suggest that exposures between approximately 90 
and 140 dB SPL do not appear to induce strong behavioral responses in 
pinnipeds exposed to nonpulse sounds in water (Jacobs and Terhune, 
2002; Costa et al., 2003; Kastelein et al., 2006c). Based on the 
limited data on pinnipeds in the water exposed to multiple pulses 
(small explosives, impact pile driving, and seismic sources), exposures 
in the approximately 150 to 180 dB SPL range generally have limited 
potential to induce avoidance behavior in pinnipeds (Harris et al., 
2001; Blackwell et al., 2004; Miller et al., 2004). If pinnipeds are 
exposed to sonar or other active acoustic sources they may react in a 
number of ways depending on their experience with the sound source and 
what activity they are engaged in at the time of the acoustic exposure. 
Pinnipeds may not react at all until the sound source is approaching 
within a few hundred meters and then may alert, ignore the stimulus, 
change their

[[Page 31809]]

behaviors, or avoid the immediate area by swimming away or diving. 
Effects on pinnipeds in the Study Area that are taken by Level B 
harassment, on the basis of reports in the literature as well as Navy 
monitoring from past activities, will likely be limited to reactions 
such as increased swimming speeds, increased surfacing time, or 
decreased foraging (if such activity were occurring). Most likely, 
individuals will simply move away from the sound source and be 
temporarily displaced from those areas, or not respond at all. In areas 
of repeated and frequent acoustic disturbance, some animals may 
habituate or learn to tolerate the new baseline or fluctuations in 
noise level. Habituation can occur when an animal's response to a 
stimulus wanes with repeated exposure, usually in the absence of 
unpleasant associated events (Wartzok et al., 2003). While some animals 
may not return to an area, or may begin using an area differently due 
to training and testing activities, most animals are expected to return 
to their usual locations and behavior. Given their documented tolerance 
of anthropogenic sound (Richardson et al., 1995 and Southall et al., 
2007), repeated exposures of individuals (e.g., harbor seals) to levels 
of sound that may cause Level B harassment are unlikely to result in 
hearing impairment or to significantly disrupt foraging behavior. As 
stated above, pinnipeds may habituate to or become tolerant of repeated 
exposures over time, learning to ignore a stimulus that in the past has 
not accompanied any overt threat.
    Thus, even repeated Level B harassment of some small subset of the 
overall stock is unlikely to result in any significant realized 
decrease in fitness to those individuals, and would not result in any 
adverse impact to the stock as a whole. Evidence from areas where the 
Navy extensively trains and tests provides some indication of the 
possible consequences resulting from those proposed activities. In the 
confined waters of Washington State's Hood Canal where the Navy has 
been training and intensively testing for decades and harbor seals are 
present year-round, the population level has remained stable suggesting 
the area's carrying capacity may have been reached (Jeffries et al., 
2003). Within Puget Sound there are several locations where pinnipeds 
use Navy structures (e.g., submarines, security barriers) for haulouts. 
Given that animals continue to choose these areas for their resting 
behavior, it would appear there are no long-term effects or 
consequences to those animals as a result of ongoing and routine Navy 
activities.
    Generally speaking, pinniped stocks in the Study Area are thought 
to be stable or increasing. Abundance estimates for pinniped stocks in 
the Study Area are shown in Table 9. Relative to population size, 
training and testing activities are anticipated to result only in a 
limited number of takes for the majority of pinniped species. When the 
numbers of takes are compared to the estimated stock abundances and if 
one assumes that each take happens to a separate animal, less than 2 
percent of each Steller sea lion, California sea lion, northern fur 
seal, and northern elephant seal stock would be harassed (behaviorally) 
during the course of a year. More likely, fewer individuals are 
harassed, but a subset are harassed more than one time during the 
course of the year. Takes of depleted (as defined under the MMPA) 
stocks of northern fur seals (Eastern Pacific) and Guadalupe fur seals 
(Mexoco) represent only 0.7 percent and 0.07 percent of their 
respective stock.
    NMFS has determined that the Level A and Level B harassment 
exposures to the Hood Canal stock of harbor seals are not biologically 
significant to the population because (1) the vast majority of the 
exposures are within the non-injurious TTS or behavioral effects zones 
and none of the estimated exposures result in mortality; (2) the 
majority of predicted harbor seal exposures result from testing 
activities which are generally of an intermittent or short duration and 
should prevent animals from being exposed to stressors on a continuous 
basis; (3) there are no indications that the historically occurring 
activities resulting in these behavioral harassment exposures are 
having any effect on this population's survival by altering behavior 
patterns such as breeding, nursing, feeding, or sheltering; (4) the 
population has been stable and likely at carrying capacity (Jeffries et 
al., 2003; Gaydos et al., 2013); (5) the population continues to use 
known large haulouts in Hood Canal and Dabob Bay that are adjacent to 
Navy testing and training activities (London et al., 2012); (6) the 
population continues to use known haulouts for pupping; and (7) the 
population continues to use the waters in and around Dabob Bay and Hood 
Canal.
    The Guadalupe fur seal is the only ESA-listed pinniped species 
found within the NWTT Study Area. Guadalupe fur seals are considered 
``seasonally migrant'' and are present within the offshore portion of 
the Study Area during the warm season (summer and early autumn) and 
during that portion of the year may be exposed to sonar and other 
active acoustic sources associated with training and testing 
activities. Predicted Level B takes of Guadalupe fur seals in the Study 
Area represent a negligible percentage of the San Miguel Island stock. 
Furthermore, critical habitat has not been designated for Guadalupe fur 
seals.
    We believe that factors described above, as well as the available 
body of evidence from past Navy activities in the Study Area, 
demonstrate that the potential effects of the specified activity will 
have only short-term effects on individuals. The NWTT training and 
testing activities are not expected to occur in an area/time of 
specific importance for reproductive, feeding, or other known critical 
behaviors for pinnipeds. Consequently, the activities are not expected 
to adversely impact annual rates of recruitment or survival of pinniped 
species and will therefore not result in population-level impacts.

Long-Term Consequences

    The best assessment of long-term consequences from training and 
testing activities will be to monitor the populations over time within 
a given Navy range complex. A U.S. workshop on Marine Mammals and Sound 
(Fitch et al., 2011) indicated a critical need for baseline biological 
data on marine mammal abundance, distribution, habitat, and behavior 
over sufficient time and space to evaluate impacts from human-generated 
activities on long-term population survival. The Navy has developed 
monitoring plans for protected marine mammals occurring on Navy ranges 
with the goal of assessing the impacts of training and testing 
activities on marine species and the effectiveness of the Navy's 
current mitigation practices. Continued monitoring efforts over time 
will be necessary to completely evaluate the long-term consequences of 
exposure to noise sources.
    Since 2006 across all Navy Range Complexes (in the Atlantic, Gulf 
of Mexico, and the Pacific), there have been more than 80 reports; 
Major Exercise Reports, Annual Exercise Reports, and Monitoring 
Reports. For the Pacific since 2011, there have been 29 monitoring and 
exercise reports (as shown in Table 6-1 of the LOA application) 
submitted to NMFS to further research goals aimed at understanding the 
Navy's impact on the environment as it carries out its mission to train 
and test.
    In addition to this multi-year record of reports from across the 
Navy, there have also been ongoing Behavioral Response Study research 
efforts (in

[[Page 31810]]

Southern California and the Bahamas) specifically focused on 
determining the potential effects from Navy mid-frequency sonar 
(Southall et al., 2011, 2012; Tyack et al., 2011; DeRuiter et al., 
2013b; Goldbogen et al., 2013; Moretti et al., 2014). This multi-year 
compendium of monitoring, observation, study, and broad scientific 
research is informative with regard to assessing the effects of Navy 
training and testing in general. Given that this record involves many 
of the same Navy training and testing activities being considered for 
the Study Area, and because it includes all the marine mammal taxonomic 
families and many of the same species, this compendium of Navy 
reporting is directly applicable to the Study Area. Other research 
findings related to the general topic of long-term impacts are 
discussed above in the Species/Group Specific Analysis.
    Based on the findings from surveys in Puget Sound and research 
efforts and monitoring before, during, and after training and testing 
events across the Navy since 2006, NMFS' assessment is that it is 
unlikely there would be impacts to populations of marine mammals having 
any long-term consequences as a result of the proposed continuation of 
training and testing in the ocean areas historically used by the Navy, 
including the Study Area. This assessment of likelihood is based on 
four indicators from areas in the Pacific where Navy training and 
testing has been ongoing for decades: (1) Evidence suggesting or 
documenting increases in the numbers of marine mammals present 
(Calambokidis and Barlow, 2004; Calambokidis et al., 2009a; Falcone et 
al., 2009; Hildebrand and McDonald, 2009; Berman-Kowalewski et al., 
2010; Moore and Barlow, 2011; Barlow et al. 2011; Falcone and Shorr, 
2012; Kerosky et al., 2012; Smultea et al., 2013), (2) examples of 
documented presence and site fidelity of species and long-term 
residence by individual animals of some species (Hooker et al., 2002; 
McSweeney et al., 2007; McSweeney et al., 2009; McSweeney et al., 2010; 
Martin and Kok, 2011; Baumann-Pickering et al., 2012; Falcone and 
Schorr, 2014), (3) use of training and testing areas for breeding and 
nursing activities (Littnan, 2010), and (4) 6 years of comprehensive 
monitoring data indicating a lack of any observable effects to marine 
mammal populations as a result of Navy training and testing activities.
    To summarize, while the evidence covers most marine mammal 
taxonomic suborders, it is limited to a few species and only suggestive 
of the general viability of those species in intensively used Navy 
training and testing areas. There is no direct evidence that routine 
Navy training and testing spanning decades has negatively impacted 
marine mammal populations at any Navy Range Complex. Although there 
have been a few strandings associated with use of sonar in other 
locations (see U.S. Department of the Navy, 2013b), Ketten (2012) has 
recently summarized, ``to date, there has been no demonstrable evidence 
of acute, traumatic, disruptive, or profound auditory damage in any 
marine mammal as the result of anthropogenic noise exposures, including 
sonar.'' Therefore, based on the best available science (Barlow et al., 
2011; Falcone et al., 2009; Falcone and Schorr, 2012, 2014; Littnan, 
2011; Martin and Kok, 2011; McCarthy et al., 2011; McSweeney et al., 
2007; McSweeney et al., 2009; Moore and Barlow, 2011; Tyack et al., 
2011; Southall et al., 2012; Manzano-Roth et al., 2013; DeRuiter et 
al., 2013b; Goldbogen et al., 2013; Moretti et al., 2014; Smultea and 
Jefferson, 2014), including data developed in the series of reports 
submitted to NMFS, we believe that long-term consequences for 
individuals or populations are unlikely to result from Navy training 
and testing activities in the Study Area.

Preliminary Determination

    Training and testing activities proposed in the NWTT Study Area 
would result in Level B and Level A takes, as summarized in Tables 17-
21. Based on best available science, as summarized in this proposed 
rule and in the January 2014 DEIS/OEIS (Section 3.4.4.1), NMFS 
concludes that exposures to marine mammal species and stocks due to 
NWTT activities would result in only short-term (temporary and short in 
duration) and relatively infrequent effects to most individuals 
exposed, and not of the type or severity that would be expected to be 
additive for the generally small portion of the stocks and species 
likely to be exposed. Marine mammal takes from Navy activities are not 
expected to impact annual rates of recruitment or survival and will 
therefore not result in population-level impacts for the following 
reasons:
     Most acoustic exposures (greater than 99 percent) are 
within the non-injurious TTS or behavioral effects zones (Level B 
harassment consisting of generally temporary modifications in behavior) 
and none of the estimated exposures result in mortality.
     Although the numbers presented in Tables 17-21 represent 
estimated harassment under the MMPA, as described above, they are 
conservative estimates of harassment, primarily by behavioral 
disturbance, and made without taking into consideration all possible 
reductions as a result of standard operating procedures and mitigation 
measures (only a subset of mitigations are factored into the post-
modeling analysis).
     Additionally, the protective measures described in the 
Proposed Mitigation section above are designed to reduce sound exposure 
and explosive effects on marine mammals to levels below those that may 
cause physiological effects (injury) and to achieve the least 
practicable adverse effect on marine mammal species or stocks.
     Range complexes where intensive training and testing have 
been occurring for decades have populations of multiple species with 
strong site fidelity (including highly sensitive resident beaked whales 
at some locations) and increases in the number of some species.
     Years of monitoring of Navy-wide activities (since 2006) 
have documented hundreds of thousands of marine mammals on the range 
complexes and there are only two instances of overt behavioral change 
that have been observed.
     Years of monitoring of Navy-wide activities on the range 
complexes have documented no demonstrable instances of injury to marine 
mammals as a direct result of non-impulsive acoustic sources.
     In at least three decades of the same type of activities, 
only one instance of injury to marine mammals (March 4, 2011; three 
long-beaked common dolphin off Southern California) has occurred as a 
known result of training or testing using an impulsive source 
(underwater explosion). Of note, the time-delay firing underwater 
explosive training activity implicated in the March 4 incident is not 
proposed for the training activities in the NWTT Study Area.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat and dependent 
upon the implementation of the mitigation and monitoring measures, NMFS 
preliminarily finds that the total taking from Navy training and 
testing exercises in the NWTT Study Area will have a negligible impact 
on the affected species or stocks. NMFS has proposed regulations for 
these exercises that prescribe the means of effecting the least 
practicable adverse impact on marine mammals and their habitat and set 
forth requirements pertaining to the monitoring and reporting of that 
taking.

[[Page 31811]]

Subsistence Harvest of Marine Mammals

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

ESA

    There are nine marine mammal species under NMFS jurisdiction that 
are listed as endangered or threatened under the ESA with confirmed or 
possible occurrence in the NWTT Study Area: North Pacific right whale, 
blue whale, humpback whale, fin whale, sei whale, gray whale (Western 
North Pacific stock), sperm whale, killer whale (Eastern North Pacific 
Southern Resident stock), and Guadalupe fur seal. The Navy will consult 
with NMFS pursuant to section 7 of the ESA, and NMFS will also consult 
internally on the issuance of LOAs under section 101(a)(5)(A) of the 
MMPA for NWTT activities. Consultation will be concluded prior to a 
determination on the issuance of the final rule and an LOA.

NEPA

    NMFS is a cooperating agency on the Navy's NWTT DEIS/OEIS, which 
was prepared and released to the public in January 2014. Upon 
completion, the Final EIS/OEIS (FEIS/OEIS) will be made available for 
public review and posted on NMFS' Web site: http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm. NMFS intends to adopt the Navy's 
NWTT FEIS/OEIS, if adequate and appropriate. Currently, we believe that 
the adoption of the Navy's NWTT FEIS/OEIS will allow NMFS to meet its 
responsibilities under NEPA for the issuance of regulations and LOAs 
for NWTT. If necessary, however, NMFS will supplement the existing 
analysis to ensure that we comply with NEPA prior to the issuance of 
the final rule or LOA.

NMSA

    Some Navy NWTT activities will occur within the Olympic Coast 
National Marine Sanctuary (OCNMS). Federal agency actions that are 
likely to injure sanctuary resources are subject to consultation with 
the NOAA Office of National Marine Sanctuaries (ONMS) under section 
304(d) of the National Marine Sanctuaries Act (NMSA). The Navy analyzed 
potential impacts to sanctuary resources and has provided the analysis 
in the January 2014 NWTT DEIS/OEIS. Where the Navy either proposes new 
military activities or proposes to modify existing military activities 
that are otherwise exempted by individual sanctuary regulations at 15 
CFR part 922 in a way that the modified activities would adversely 
impact sanctuary resources and qualities, the Navy will initiate 
consultation with ONMS.
    NMFS is currently consulting with ONMS on the issuance of 
regulations and LOAs for NWTT activities. Consultation will be 
concluded prior to a determination on the issuance of the final rule 
and an LOA.

Classification

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

List of Subjects in 50 CFR Part 218

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

    Dated: May 26, 2015.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine 
Fisheries Service.
    For reasons set forth in the preamble, 50 CFR part 218 is proposed 
to be amended as follows:

PART 218--REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE 
MAMMALS

0
1. The authority citation for part 218 continues to read as follow:

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

0
2. In Sec.  218.75, revise introductory paragraph (f)(1)(ii)(F) as 
follows:


Sec.  218.75  Requirements for monitoring and reporting.

* * * * *
    (f) * * *
    (1) * * *
    (ii) * * *
    (F) Individual marine mammal sighting information for each sighting 
when mitigation occurred during each MTE.
* * * * *
0
3. In Sec.  218.85, revise introductory paragraph (f)(1)(ii)(F) as 
follows:


Sec.  218.85  Requirements for monitoring and reporting.

* * * * *
    (f) * * *
    (1) * * *
    (ii) * * *
    (F) Individual marine mammal sighting information for each sighting 
when mitigation occurred during each MTE.
* * * * *
0
4. In Sec.  218.125, revise introductory paragraph (f)(1)(ii) as 
follows:


Sec.  218.125  Requirements for monitoring and reporting.

* * * * *
    (f) * * *
    (1) * * *
    (ii) Individual marine mammal sighting information for each 
sighting in each exercise when mitigation occurred.
* * * * *

Subpart M--[Removed and Reserved]

0
5. Remove and reserve subpart M, consisting of Sec. Sec.  218.110 
through 218.119.

Subpart R--[Removed and Reserved]

0
6. Remove and reserve subpart R, consisting of Sec. Sec.  218.170 
through 218.178.
0
7. Subpart O is added to part 218 to read as follows:

[[Page 31812]]

Subpart O--Taking and Importing Marine Mammals; U.S. Navy's Northwest 
Training and Testing (NWTT) Study Area
Sec.
218.140 Specified activity and specified geographical region.
218.141 Effective dates and definitions.
218.142 Permissible methods of taking.
218.143 Prohibitions.
218.144 Mitigation.
218.145 Requirements for monitoring and reporting.
218.146 Applications for Letters of Authorization
218.147 Letters of Authorization.
218.148 Renewal and Modifications of Letters of Authorization and 
Adaptive Management.

Subpart O--Taking and Importing Marine Mammals; U.S. Navy's 
Northwest Training and Testing (NWTT) Study Area


Sec.  218.140  Specified activity and specified geographical region.

    (a) Regulations in this subpart apply only to the U.S. Navy for the 
taking of marine mammals that occurs in the area outlined in paragraph 
(b) of this section and that occurs incidental to the activities 
described in paragraph (c) of this section.
    (b) The taking of marine mammals by the Navy is only authorized if 
it occurs within the NWTT Study Area, which is composed of established 
maritime operating and warning areas in the eastern North Pacific Ocean 
region, including areas of the Strait of Juan de Fuca, Puget Sound, and 
Western Behm Canal in southeastern Alaska. The Study Area includes air 
and water space within and outside Washington state waters, and outside 
state waters of Oregon and Northern California. The Study Area includes 
four existing range complexes and facilities: The Northwest Training 
Range Complex (NWTRC), the Keyport Range Complex, Carr Inlet Operations 
Area, and SEAFAC. In addition to these range complexes, the Study Area 
also includes Navy pierside locations where sonar maintenance and 
testing occurs as part of overhaul, modernization, maintenance and 
repair activities at NAVBASE Kitsap, Bremerton; NAVBASE Kitsap, Bangor; 
and Naval Station Everett.
    (c) The taking of marine mammals by the Navy is only authorized if 
it occurs incidental to the following activities within the designated 
amounts of use:
    (1) Sonar and other Active Sources Used During Training:
    (i) Mid-frequency (MF) Source Classes:
    (A) MF1--an average of 166 hours per year.
    (B) MF3--an average of 70 hours per year.
    (C) MF4--an average of 4 hours per year.
    (D) MF5--an average of 896 items per year.
    (E) MF11--an average of 16 hours per year.
    (ii) High-frequency (HF) Source Classes:
    (A) HF1--an average of 48 hours per year.
    (B) HF4--an average of 384 hours per year.
    (C) HF6--an average of 192 items per year.
    (iii) Anti-Submarine Warfare (ASW) Source Classes:
    (A) ASW2--an average of 720 items per year per year.
    (B) ASW3--an average of 78 hours per year.
    (2) Sonar and other Active Sources Used During Testing:
    (i) Low-frequency (LF) Source Classes:
    (A) LF4--an average of 110 hours per year.
    (B) LF5--an average of 71 hours per year.
    (ii) Mid-frequency (MF):
    (A) MF3--an average of 161 hours per year.
    (B) MF4--an average of 10 hours per year.
    (C) MF5--an average of 273 items per year.
    (D) MF6--an average of 12 items per year.
    (E) MF8--an average of 40 hours per year.
    (F) MF9--an average of 1,183 hours per year.
    (G) MF10--an average of 1,156 hours per year.
    (H) MF11--an average of 34 hours per year.
    (I) MF12--an average of 24 hours per year.
    (iii) High-frequency (HF) and Very High-frequency (VHF):
    (A) HF1--an average of 161 hours per year.
    (B) HF3--an average of 145 hours per year.
    (C) HF5--an average of 360 hours per year.
    (D) HF6--an average of 2,099 hours per year.
    (iv) VHF:
    (A) VHF2--an average of 35 hours per year.
    (v) ASW:
    (A) ASW1--an average of 16 hours per year.
    (B) ASW2--an average of 64 hours per year.
    (C) ASW2--an average of 170 items per year.
    (D) ASW3--an average of 444 hours per year.
    (E) ASW4--an average of 1,182 items per year.
    (vi) Acoustic Modems (M):
    (A) M3--an average of 1,519 hours per year.
    (vii) Torpedoes (TORP):
    (A) TORP1--an average of 315 items per year.
    (B) TORP2--an average of 299 items per year.
    (viii) Swimmer Detection Sonar (SD):
    (A) SD1--an average of 757 hours per year.
    (ix) Synthetic Aperture Sonar (SAS):
    (A) SAS2--an average of 798 hours per year.
    (3) Impulsive Source Detonations During Training:
    (i) Explosive Classes:
    (A) E1 (0.1 to 0.25 pound [lb] NEW)--an average of 48 detonations 
per year.
    (B) E3 (>0.5 to 2.5 lb NEW)--an average of 6 detonations per year.
    (C) E5 (>5 to 10 lb NEW)--an average of 80 detonations per year.
    (D) E10 (>250 to 500 lb NEW)--an average of 4 detonations per year.
    (E) E12 (>650 to 1,000 lb NEW)--an average of 10 detonations per 
year.
    (ii) [Reserved].
    (4) Impulsive Source Detonations During Testing:
    (i) Explosive Classes:
    (A) E3 (>0.5 to 2.5 lb NEW)--an average of 72 detonations per year.
    (B) E4 (>2.5 to 5 lb NEW)--an average of 70 detonations per year.
    (C) E8 (>60 to 100 lb NEW)--an average of 3 detonations per year.
    (D) E11 (500 to 650 lb NEW)--an average of 3 detonations 
per year.
    (ii) [Reserved]


Sec.  218.141  Effective dates.

    Regulations in this subpart are effective June 2, 2015 through June 
2, 2020.


Sec.  218.142  Permissible methods of taking.

    (a) Under Letters of Authorization (LOAs) issued pursuant to Sec.  
218.147, the Holder of LOA may incidentally, but not intentionally, 
take marine mammals within the area described in Sec.  218.140, 
provided the activity is in compliance with all terms, conditions, and 
requirements of these regulations and the appropriate LOA.
    (b) The activities identified in Sec.  218.140(c) must be conducted 
in a manner that minimizes, to the greatest extent practicable, any 
adverse impacts on marine mammals and their habitat.
    (c) The incidental take of marine mammals under the activities 
identified in Sec.  218.140(c) is limited to the following species, by 
the identified method of take and the indicated number of times:
    (1) Level B Harassment for all Training Activities:

[[Page 31813]]

    (i) Mysticetes:
    (A) Blue whale (Balaenoptera musculus)--25 (an average of 5 per 
year).
    (B) Fin whale (Balaenoptera physalus)--125 (an average of 25 per 
year).
    (C) Gray whale (Eschrichtius robustus)--30 (an average of 6 per 
year).
    (D) Humpback whale (Megaptera novaeangliae)--60 (an average of 12 
per year).
    (E) Minke whale (Balaenoptera acutorostrata)--90 (an average of 18 
per year).
    (ii) Odontocetes:
    (A) Baird's beaked whale (Berardius bairdii)--2,955 (an average of 
591 per year).
    (B) Mesoplodont beaked whale Mesoplodon spp.)--7,085 (an average of 
1,417 per year).
    (C) Cuvier's beaked whale Ziphius cavirostris--1,765 (an average of 
353 per year).
    (D) Dall's porpoise Phocoenoidea dalli--18,188 (an average of 3,732 
per year).
    (E) Harbor porpoise Phocoena phocoena--441,984 (an average of 
88,932 per year).
    (F) Killer whale Orcinus orca--110 (an average of 24 per year).
    (G) Kogia spp.--365 (an average of 73 per year).
    (H) Northern right whale dolphin Lissodelphis borealis--6,660 (an 
average of 1,332 per year).
    (I) Pacific white-sided dolphin Lagenorhynchus obliquidens--17,408 
(an average of 3,482 per year).
    (J) Risso's dolphin Grampus griseus--3,285 (an average of 657 per 
year).
    (K) Short-beaked common dolphin Delphinus delphis--3,670 (an 
average of 734 per year).
    (L) Sperm whale Physeter macrocephalus--405 (an average of 81 per 
year).
    (M) Striped dolphin Stenella coerulealba--110 (an average of 22 per 
year).
    (iii) Pinnipeds:
    (A) California sea lion Zalophus californianus--4,038 (an average 
of 814 per year).
    (B) Steller sea lion Eumetopias jubatus--1,986 (an average of 404 
per year).
    (C) Guadalupe fur seal Arctocephalus townsendi--35 (an average of 7 
per year).
    (D) Harbor seal Phoca vitulina--4,161 (an average of 832 per year).
    (E) Northern elephant seal Mirounga angustirostris--6,353 (an 
average of 1,271 per year).
    (F) Northern fur seal Callorhinus ursinus--12,660 (an average of 
2,532 per year).
    (2) Level A Harassment for all Training Activities:
    (i) Mysticetes:
    (A) [Reserved]
    (B) [Reserved]
    (ii) Odontocetes:
    (A) Dall's porpoise (Phocoenoidea dalli)--20 (an average of 4 per 
year).
    (B) Harbor porpoise (Phocoena phocoena)--5 (an average of 1 per 
year).
    (iii) Pinnipeds:
    (A) Harbor seal (Phoca vitulina)--30 (an average of 6 per year).
    (B) [Reserved]
    (3) Level B Harassment for all Testing Activities:
    (i) Mysticetes:
    (A) Blue whale (Balaenoptera musculus)--30 (an average of 6 per 
year).
    (B) Fin whale (Balaenoptera physalus)--180 (an average of 36 per 
year).
    (C) Gray whale (Eschrichtius robustus)--55 (an average of 11 per 
year).
    (D) Humpback whale (Megaptera novaeangliae)--225 (an average of 45 
per year).
    (E) Minke whale (Balaenoptera acutorostrata)--90 (an average of 18 
per year).
    (F) Sei whale (Balaenoptera borealis)--10 (an average of 2 per 
year).
    (ii) Odontocetes:
    (A) Baird's beaked whale (Berardius bairdii)--870 (an average of 
174 per year).
    (B) Mesoplodont beaked whale (Mesoplodon spp.)--1,845 (an average 
of 369 per year).
    (C) Cuvier's beaked whale (Ziphius cavirostris)--530 (an average of 
106 per year).
    (D) Dall's porpoise (Phocoenoidea dalli)--56,695 (an average of 
11,339 per year).
    (E) Harbor porpoise (Phocoena phocoena)--246,465 (an average of 
49,293 per year).
    (F) Killer whale (Orcinus orca)--1, 130 (an average of 226 per 
year).
    (G) Kogia spp.--530 (an average of 106 per year).
    (H) Northern right whale dolphin (Lissodelphis borealis)--10 (an 
average of 2,038 per year).
    (I) Pacific white-sided dolphin (Lagenorhynchus obliquidens)--
24,360 (an average of 4,872 per year).
    (J) Risso's dolphin (Grampus griseus)--5,770 (an average of 1,154 
per year).
    (K) Short-beaked common dolphin (Delphinus delphis)--8,140 (an 
average of 1,628 per year).
    (L) Sperm whale (Physeter macrocephalus)--390 (an average of 78 per 
year).
    (M) Striped dolphin (Stenella coerulealba)--70 (an average of 14 
per year).
    (iii) Pinnipeds:
    (A) California sea lion (Zalophus californianus)--10,365 (an 
average of 2,073 per year).
    (B) Steller sea lion (Eumetopias jubatus)--2,520 (an average of 504 
per year).
    (C) Guadalupe fur seal (Arctocephalus townsendi)--15 (an average of 
3 per year).
    (D) Harbor seal (Phoca vitulina)--312,690 (an average of 62,538 per 
year).
    (E) Northern elephant seal (Mirounga angustirostris)--6,625 (an 
average of 1,325 per year).
    (F) Northern fur seal (Callorhinus ursinus)--9,285 (an average of 
1,857 per year).
    (4) Level A Harassment for all Testing Activities:
    (i) Mysticetes:
    (A) [Reserved]
    (B) [Reserved]
    (ii) Odontocetes:
    (A) Kogia spp.--5 (an average of 1 per year).
    (B) Dall' porpoise (Phocoenoidea dalli)--215 (an average of 43 per 
year).
    (C) Harbor porpoise (Phocoena phocoena)--220 (an average of 44 per 
year).
    (iii) Pinnipeds:
    (A) Harbor seal (Phoca vitulina)--430 (an average of 86 per 
year).(B) Northern elephant seal (Mirounga angustirostris)--10 (an 
average of 2 per year).
    (C) [Reserved]


Sec.  218.143  Prohibitions.

    Notwithstanding takings contemplated in Sec.  218.142 and 
authorized by an LOA issued under Sec. Sec.  216.106 and 218.147 of 
this chapter, no person in connection with the activities described in 
Sec.  218.140 may:
    (a) Take any marine mammal not specified in Sec.  218.142(c);
    (b) Take any marine mammal specified in Sec.  218.142(c) other than 
by incidental take as specified in Sec.  218.142(c);
    (c) Take a marine mammal specified in Sec.  218.142(c) if such 
taking results in more than a negligible impact on the species or 
stocks of such marine mammal; or
    (d) Violate, or fail to comply with, the terms, conditions, and 
requirements of these regulations or an LOA issued under Sec. Sec.  
216.106 and 218.147.


Sec.  218.144  Mitigation.

    (a) When conducting training and testing activities, as identified 
in Sec.  218.140, the mitigation measures

[[Page 31814]]

contained in the LOA issued under Sec. Sec.  216.106 and 218.147 of 
this chapter must be implemented. These mitigation measures include, 
but are not limited to:
    (1) Lookouts--The following are protective measures concerning the 
use of Lookouts.
    (i) Lookouts positioned on surface ships will be dedicated solely 
to diligent observation of the air and surface of the water. Their 
observation objectives will include, but are not limited to, detecting 
the presence of biological resources and recreational or fishing boats, 
observing mitigation zones, and monitoring for vessel and personnel 
safety concerns.
    (ii) Lookouts positioned ashore, in aircraft or on boats will, to 
the maximum extent practicable and consistent with aircraft and boat 
safety and training and testing requirements, comply with the 
observation objectives described in paragraph (a)(1)(i) of this 
section.
    (iii) Lookout measures for non-impulsive sound:
    (A) With the exception of vessels less than 65 ft (20 m) in length 
and the Littoral Combat Ship (and similar vessels which are minimally 
manned), ships using low-frequency or hull-mounted mid-frequency active 
sonar sources associated with anti-submarine warfare and mine warfare 
activities at sea will have two Lookouts at the forward position of the 
vessel. For the purposes of this rule, low-frequency active sonar does 
not include surface towed array surveillance system low-frequency 
active sonar.
    (B) While using low-frequency or hull-mounted mid-frequency active 
sonar sources associated with anti-submarine warfare and mine warfare 
activities at sea, vessels less than 65 ft (20 m) in length and the 
Littoral Combat Ship (and similar vessels which are minimally manned) 
will have one Lookout at the forward position of the vessel due to 
space and manning restrictions.
    (C) Ships conducting active sonar activities while moored or at 
anchor (including pierside or shore-based testing or maintenance) will 
maintain one Lookout.
    (D) Small boats, range craft, minimally manned vessels, or aircraft 
conducting hull-mounted mid-frequency testing will employ one Lookout.
    (E) Ships or aircraft conducting non-hull-mounted mid-frequency 
active sonar, such as helicopter dipping sonar systems, will maintain 
one Lookout.
    (F) Surface ships or aircraft conducting high-frequency or non-
hull-mounted mid-frequency active sonar activities associated with 
anti-submarine warfare and mine warfare activities at sea will have one 
Lookout.
    (iv) Lookout measures for explosives and impulsive sound:
    (A) Aircraft conducting improved extended echo ranging sonobuoy 
activities will have one Lookout.
    (B) Aircraft conducting explosive sonobuoy activities using >0.5 to 
2.5-lb net explosive weight (NEW) will have one Lookout.
    (C) General mine countermeasure and neutralization activities 
involving positive control diver placed charges using >0.5 to 2.5 lb 
NEW will have a total of two Lookouts (one Lookout positioned in each 
of the two support vessels). All divers placing the charges on mines 
will support the Lookouts while performing their regular duties. The 
divers and Lookouts will report all marine mammal sightings to their 
dive support vessel.
    (D) Surface vessels or aircraft conducting small- and medium-
caliber gunnery exercises will have one Lookout. Towing vessels, if 
applicable, will also maintain one Lookout.
    (E) Aircraft conducting missile exercises against a surface target 
will have one Lookout.
    (F) Aircraft conducting explosive bombing exercises will have one 
Lookout and any surface vessels involved will have trained Lookouts.
    (G) During explosive torpedo testing from aircraft one Lookout will 
be used and positioned in an aircraft. During explosive torpedo testing 
from a surface ship the Lookout procedures implemented for hull-mounted 
mid-frequency active sonar activities will be used.
    (H) Ships conducting explosive and non-explosive large-caliber 
gunnery exercises will have one Lookout. This may be the same Lookout 
used for small, medium, and large-caliber gunnery exercises using a 
surface target when that activity is conducted from a ship against a 
surface target.
    (v) Lookout measures for physical strike and disturbance:
    (A) While underway, surface ships will have at least one Lookout.
    (B) During activities using towed in-water devices towed from a 
manned platform, one Lookout will be used. During activities in which 
in-water devices are towed by unmanned platforms, a manned escort 
vessel will be included and one Lookout will be employed.
    (C) Activities involving non-explosive practice munitions (e.g., 
small-, medium-, and large-caliber gunnery exercises) using a surface 
target will have one Lookout.
    (D) During non-explosive bombing exercises one Lookout will be 
positioned in an aircraft and trained Lookouts will be positioned in 
any surface vessels involved.
    (2) Mitigation zones--The following are protective measures 
concerning the implementation of mitigation zones.
    (i) Mitigation zones will be measured as the radius from a source 
and represent a distance to be monitored.
    (ii) Visual detections of marine mammals (or sea turtles) within a 
mitigation zone will be communicated immediately to a watch station for 
information dissemination and appropriate action.
    (iii) Mitigation zones for non-impulsive sound:
    (A) The Navy shall ensure that hull-mounted mid-frequency active 
sonar transmission levels are limited to at least 6 dB below normal 
operating levels if any detected marine mammals (or sea turtles) are 
within 1,000 yd. (914 m) of the sonar dome (the bow).
    (B) The Navy shall ensure that hull-mounted mid-frequency active 
sonar transmissions are limited to at least 10 dB below the equipment's 
normal operating level if any detected marine mammals (or sea turtles) 
are within 500 yd. (457 m) of the sonar dome.
    (C) The Navy shall ensure that hull-mounted mid-frequency active 
sonar transmissions are ceased if any detected cetaceans (or sea 
turtles) are within 200 yd. (180 m) and pinnipeds are within 100 yd. 
(90 m) of the sonar dome. Transmissions will not resume until the 
marine mammal has been observed exiting the mitigation zone, is thought 
to have exited the mitigation zone based on its course and speed, has 
not been detected for 30 minutes, the vessel has transited more than 
2,000 yd. beyond the location of the last detection, or the Lookout 
concludes that dolphins are deliberately closing in on the ship to ride 
the ship's bow wave (and there are no other marine mammal sightings 
within the mitigation zone). Active transmission may resume when 
dolphins are bow riding because they are out of the main transmission 
axis of the active sonar while in the shallow-wave area of the ship 
bow. The pinniped mitigation zone does not apply for pierside or shore-
based testing in the vicinity of pinnipeds hauled out on man-made 
structures and vessels.
    (D) The Navy shall ensure that low-frequency active sonar 
transmission levels are ceased if any detected cetaceans (or sea 
turtles) are within 200 yd. (180 m) and pinnipeds are within 100 yd. 
(90 m) of the source. Transmissions will not resume until the marine 
mammal has been observed

[[Page 31815]]

exiting the mitigation zone, is thought to have exited the mitigation 
zone based on its course and speed, has not been detected for 30 
minutes, or the vessel has transited more than 2,000 yd. beyond the 
location of the last detection. The pinniped mitigation zone does not 
apply for pierside testing in the vicinity of pinnipeds hauled out on 
man-made structures and vessels.
    (E) The Navy shall ensure that high-frequency and non-hull-mounted 
mid-frequency active sonar transmission levels are ceased if any 
detected cetaceans are within 200 yd. (180 m) and pinnipeds are within 
100 yd. (90 m) of the source. Transmissions will not resume until the 
marine mammal has been observed exiting the mitigation zone, is thought 
to have exited the mitigation zone based on its course and speed, the 
mitigation zone has been clear from any additional sightings for a 
period of 10 minutes for an aircraft-deployed source, the mitigation 
zone has been clear from any additional sightings for a period of 30 
minutes for a vessel-deployed source, the vessel or aircraft has 
repositioned itself more than 400 yd. (370 m) away from the location of 
the last sighting, or the vessel concludes that dolphins are 
deliberately closing in to ride the vessel's bow wave (and there are no 
other marine mammal sightings within the mitigation zone). The pinniped 
mitigation zone does not apply for pierside or shore-based testing in 
the vicinity of pinnipeds hauled out on man-made structures and 
vessels.
    (iv) Mitigation zones for explosive and impulsive sound:
    (A) For activities using IEERs, explosive detonations will cease if 
a marine mammal, sea turtle, or concentrations of floating vegetation 
are sighted within a 600-yd. (550 m) mitigation zone. Detonations will 
recommence if the animal is observed exiting the mitigation zone, the 
animal is thought to have exited the mitigation zone based on its 
course and speed, or the mitigation zone has been clear from any 
additional sightings for a period of 30 minutes.
    (B) A mitigation zone with a radius of 350 yd. (320 m) shall be 
established for explosive signal underwater sonobuoys using >0.5 to 2.5 
lb net explosive weight. Detonations will recommence if the animal is 
observed exiting the mitigation zone, the animal is thought to have 
exited the mitigation zone based on its course and speed, or the 
mitigation zone has been clear from any additional sightings for a 
period of 10 minutes.
    (C) A mitigation zone with a radius of 400 yd. (366 m) shall be 
established for mine countermeasures and neutralization activities 
using positive control firing devices. Explosive detonations will cease 
if a marine mammal is sighted in the water portion of the mitigation 
zone (i.e., not on shore). Detonations will recommence if the animal is 
observed exiting the mitigation zone, the animal is thought to have 
exited the mitigation zone based on its course and speed, or the 
mitigation zone has been clear from any additional sightings for a 
period of 30 minutes.
    (D) A mitigation zone with a radius of 200 yd. (180 m) shall be 
established for small- and medium-caliber gunnery exercises with a 
surface target. Firing will cease if a marine mammal is sighted within 
the mitigation zone. Firing will recommence if the animal is observed 
exiting the mitigation zone, the animal is thought to have exited the 
mitigation zone based on its course and speed, the mitigation zone has 
been clear from any additional sightings for a period of 10 minutes for 
a firing aircraft, the mitigation zone has been clear from any 
additional sightings for a period of 30 minutes for a firing ship, or 
the intended target location has been repositioned more than 400 yd. 
(370 m) away from the location of the last sighting.
    (E) A mitigation zone with a radius of 600 yd. (550 m) shall be 
established for large-caliber gunnery exercises with a surface target. 
Firing will cease if a marine mammal is sighted within the mitigation 
zone. Firing will recommence if the animal is observed exiting the 
mitigation zone, the animal is thought to have exited the mitigation 
zone based on its course and speed, or the mitigation zone has been 
clear from any additional sightings for a period of 30 minutes.
    (F) The Navy is not proposing to use missiles with less than a 251 
lb NEW warhead in the NWTT Study Area. However, should the need arise 
to conduct training activities using missiles in this category, a 
mitigation zone with a radius of 2,000 yd. (1.8 km) shall be 
established for missile exercises with up to 250 lb net explosive 
weight and a surface target. Firing will cease if a marine mammal is 
sighted within the mitigation zone. Firing will recommence if the 
animal is observed exiting the mitigation zone, the animal is thought 
to have exited the mitigation zone based on its course and speed, or 
the mitigation zone has been clear from any additional sightings for a 
period of 10 minutes or 30 minutes (depending on aircraft type).
    (G) A mitigation zone with a radius of 2,000 yd. (1.8 km) shall be 
established for missile exercises with 251 to 500 lb NEW using a 
surface target. Firing will cease if a marine mammal is sighted within 
the mitigation zone. Firing will recommence if the animal is observed 
exiting the mitigation zone, the animal is thought to have exited the 
mitigation zone based on its course and speed, or the mitigation zone 
has been clear from any additional sightings for a period of 10 minutes 
or 30 minutes (depending on aircraft type).
    (H) A mitigation zone with a radius of 2,500 yd. (2.3 km) around 
the intended impact location for explosive bombs shall be established 
for bombing exercises. Bombing will cease if a marine mammal is sighted 
within the mitigation zone. Bombing will recommence if the animal is 
observed exiting the mitigation zone, the animal is thought to have 
exited the mitigation zone based on its course and speed, or the 
mitigation zone has been clear from any additional sightings for a 
period of 10 minutes.
    (I) A mitigation zone with a radius of 2,100 yd. (1.9 km) shall be 
established for torpedo (explosive) testing. Firing will cease if a 
marine mammal, sea turtle, or concentrations of floating vegetation are 
sighted within the mitigation zone. Firing will recommence if the 
animal is observed exiting the mitigation zone, the animal is thought 
to have exited the mitigation zone based on its course and speed, or 
the mitigation zone has been clear from any additional sightings for a 
period of 10 minutes or 30 minutes (depending on aircraft type).
    (iii) Mitigation zones for vessels and in-water devices:
    (A) A mitigation zone of 500 yd. (460 m) for observed whales and 
200 yd (183 m) for all other marine mammals (except bow riding 
dolphins) shall be established for all vessel movement during training 
activities, providing it is safe to do so. During testing activities, 
all range craft (vessels and aircraft, including helicopters) shall not 
approach within 100 yd. (90 m) of marine mammals.
    (B) A mitigation zone of 250 yd. (230 m) shall be established for 
all towed in-water devices, providing it is safe to do so.
    (vi) Mitigation zones for non-explosive practice munitions:
    (A) A mitigation zone of 200 yd. (180 m) shall be established for 
small, medium, and large caliber gunnery exercises using a surface 
target. Firing will cease if a marine mammal is sighted within the 
mitigation zone. Firing will recommence if the animal is observed 
exiting the mitigation zone, the animal is thought to have exited the 
mitigation zone based on its course and

[[Page 31816]]

speed, the mitigation zone has been clear from any additional sightings 
for a period of 10 minutes for a firing aircraft, the mitigation zone 
has been clear from any additional sightings for a period of 30 minutes 
for a firing ship, or the intended target location has been 
repositioned more than 400 yd. (370 m) away from the location of the 
last sighting.
    (B) A mitigation zone of 1,000 yd. (920 m) shall be established for 
bombing exercises. Bombing will cease if a marine mammal is sighted 
within the mitigation zone. Bombing will recommence if the animal is 
observed exiting the mitigation zone, the animal is thought to have 
exited the mitigation zone based on its course and speed, or the 
mitigation zone has been clear from any additional sightings for a 
period of 10 minutes.


Sec.  218.145  Requirements for monitoring and reporting.

    (a) The Navy is required to cooperate with the NMFS, and any other 
Federal, state or local agency monitoring the impacts of the activity 
on marine mammals.
    (b) General Notification of Injured or Dead Marine Mammals--Navy 
personnel shall ensure that NMFS is notified immediately (or as soon as 
clearance procedures allow) if an injured, stranded, or dead marine 
mammal is found during or shortly after, and in the vicinity of, any 
Navy training exercise utilizing MFAS, HFAS, or underwater explosive 
detonations. The Navy will provide NMFS with species or description of 
the animal(s), the condition of the animal(s) (including carcass 
condition if the animal is dead), location, time of first discovery, 
observed behaviors (if alive), and photo or video (if available). In 
the event that an injured, stranded, or dead marine mammal is found by 
the Navy that is not in the vicinity of, or during or shortly after, 
MFAS, HFAS, or underwater explosive detonations, the Navy will report 
the same information as listed above as soon as operationally feasible 
and clearance procedures allow.
    (c) General Notification of Ship Strike--In the event of a ship 
strike by any Navy vessel, at any time or place, the Navy shall do the 
following:
    (1) Immediately report to NMFS the species identification (if 
known), location (lat/long) of the animal (or the strike if the animal 
has disappeared), and whether the animal is alive or dead (or unknown)
    (2) Report to NMFS as soon as operationally feasible the size and 
length of animal, an estimate of the injury status (ex., dead, injured 
but alive, injured and moving, unknown, etc.), vessel class/type and 
operational status.
    (3) Report to NMFS the vessel length, speed, and heading as soon as 
feasible.
    (4) Provide NMFS a photo or video, if equipment is available
    (d) Event Communication Plan--The Navy shall develop a 
communication plan that will include all of the communication protocols 
(phone trees, etc.) and associated contact information required for 
NMFS and the Navy to carry out the necessary expeditious communication 
required in the event of a stranding or ship strike, including as 
described in the proposed notification measures above.
    (e) The Navy must conduct all monitoring and/or research required 
under the Letter of Authorization including abiding by the NWTT 
Monitoring Plan (http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm).
    (f) Annual NWTT Monitoring Plan Report--The Navy shall submit an 
annual report of the NWTT Monitoring Plan describing the implementation 
and results of the NWTT Monitoring Plan from the previous calendar 
year. Data collection methods will be standardized across range 
complexes and study areas to allow for comparison in different 
geographic locations. Although additional information will be gathered, 
the protected species observers collecting marine mammal data pursuant 
to the NWTT Monitoring Plan shall, at a minimum, provide the same 
marine mammal observation data required in Sec.  218.145. The report 
shall be submitted either 90 days after the calendar year, or 90 days 
after the conclusion of the monitoring year to be determined by the 
Adaptive Management process.
    The NWTT Monitoring Plan may be provided to NMFS within a larger 
report that includes the required Monitoring Plan reports from multiple 
range complexes and study areas (the multi-Range Complex Annual 
Monitoring Report). Such a report would describe progress of knowledge 
made with respect to monitoring plan study questions across all Navy 
ranges associated with the ICMP. Similar study questions shall be 
treated together so that progress on each topic shall be summarized 
across all Navy ranges. The report need not include analyses and 
content that does not provide direct assessment of cumulative progress 
on the monitoring plan study questions.
    (g) Annual NWTT Exercise and Testing Reports--The Navy shall submit 
preliminary reports detailing the status of authorized sound sources 
within 21 days after the anniversary of the date of issuance of the 
LOA. The Navy shall submit detailed reports 3 months after the 
anniversary of the date of issuance of the LOA. The detailed annual 
reports shall describe the level of training and testing conducted 
during the reporting period, and a summary of sound sources used (total 
annual hours or quantity [per the LOA] of each bin of sonar or other 
non-impulsive source; total annual number of each type of explosive 
exercises; total annual expended/detonated rounds [missiles, bombs, 
etc.] for each explosive bin; and improved Extended Echo-Ranging System 
(IEER)/sonobuoy summary, including total number of IEER events 
conducted in the Study Area, total expended/detonated rounds (buoys), 
and total number of self-scuttled IEER rounds. The analysis in the 
detailed reports will be based on the accumulation of data from the 
current year's report and data collected from previous reports.
    (h) 5-year Close-out Exercise and Testing Report--This report will 
be included as part of the 2020 annual exercise or testing report. This 
report will provide the annual totals for each sound source bin with a 
comparison to the annual allowance and the 5-year total for each sound 
source bin with a comparison to the 5-year allowance. Additionally, if 
there were any changes to the sound source allowance, this report will 
include a discussion of why the change was made and include the 
analysis to support how the change did or did not result in a change in 
the SEIS and final rule determinations. The report will be submitted 3 
months after the expiration of the rule. NMFS will submit comments on 
the draft close-out report, if any, within 3 months of receipt. The 
report will be considered final after the Navy has addressed NMFS' 
comments, or 3 months after the submittal of the draft if NMFS does not 
provide comments.


Sec.  218.146  Applications for Letters of Authorization.

    To incidentally take marine mammals pursuant to the regulations in 
this subpart, the U.S. citizen (as defined by Sec.  216.106) conducting 
the activity identified in Sec.  218.140(c) (the U.S. Navy) must apply 
for and obtain either an initial LOA in accordance with Sec.  218.147 
or a renewal under Sec.  218.148.


Sec.  218.147  Letters of Authorization.

    (a) An LOA, unless suspended or revoked, will be valid for a period 
of time not to exceed the period of validity of this subpart.
    (b) Each LOA will set forth:

[[Page 31817]]

    (1) Permissible methods of incidental taking;
    (2) Means of effecting the least practicable adverse impact on the 
species, its habitat, and on the availability of the species for 
subsistence uses (i.e., mitigation); and
    (3) Requirements for mitigation, monitoring and reporting.
    (c) Issuance and renewal of the LOA will be based on a 
determination that the total number of marine mammals taken by the 
activity as a whole will have no more than a negligible impact on the 
affected species or stock of marine mammal(s).


Sec.  218.148  Renewals and Modifications of Letters of Authorization 
and Adaptive Management.

    (a) A Letter of Authorization issued under Sec. Sec.  216.106 and 
218.147 of this chapter for the activity identified in Sec.  218.140(c) 
will be renewed or modified upon request of the applicant, provided 
that:
    (1) The proposed specified activity and mitigation, monitoring, and 
reporting measures, as well as the anticipated impacts, are the same as 
those described and analyzed for these regulations (excluding changes 
made pursuant to the adaptive management provision of this chapter), 
and;
    (2) NMFS determines that the mitigation, monitoring, and reporting 
measures required by the previous LOA under these regulations were 
implemented.
    (b) For LOA modification or renewal requests by the applicant that 
include changes to the activity or the mitigation, monitoring, or 
reporting (excluding changes made pursuant to the adaptive management 
provision of this chapter) that do not change the findings made for the 
regulations or result in no more than a minor change in the total 
estimated number of takes (or distribution by species or years), NMFS 
may publish a notice of proposed LOA in the Federal Register, including 
the associated analysis illustrating the change, and solicit public 
comment before issuing the LOA.
    (c) An LOA issued under Sec.  216.106 and Sec.  218.147 of this 
chapter for the activity identified in Sec.  218.144 of this chapter 
may be modified by NMFS under the following circumstances:
    (1) Adaptive Management--NMFS may modify (including augment) the 
existing mitigation, monitoring, or reporting measures (after 
consulting with the Navy regarding the practicability of the 
modifications) if doing so creates a reasonable likelihood of more 
effectively accomplishing the goals of the mitigation and monitoring 
set forth in the preamble for these regulations.
    (i) Possible sources of data that could contribute to the decision 
to modify the mitigation, monitoring, and reporting measures in an LOA:
    (A) Results from Navy's monitoring from the previous year(s);
    (B) Results from other marine mammal and/or sound research or 
studies; or
    (C) Any information that reveals marine mammals may have been taken 
in a manner, extent, or number not authorized by these regulations or 
subsequent LOAs.
    (ii) If, through adaptive management, the modifications to the 
mitigation, monitoring, or reporting measures are substantial, NMFS 
would publish a notice of proposed LOA in the Federal Register and 
solicit public comment.
    (2) Emergencies--If NMFS determines that an emergency exists that 
poses a significant risk to the well-being of the species or stocks of 
marine mammals specified in Sec.  218.142(c), an LOA may be modified 
without prior notification and an opportunity for public comment. 
Notification would be published in the Federal Register within 30 days 
of the action.

[FR Doc. 2015-13038 Filed 6-2-15; 8:45 am]
BILLING CODE 3510-22-P