[Federal Register Volume 74, Number 82 (Thursday, April 30, 2009)]
[Proposed Rules]
[Pages 20156-20199]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-9645]



[[Page 20155]]

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Part IV





Department of Commerce





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National Oceanic and Atmospheric Administration



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50 CFR Part 218



Taking and Importing Marine Mammals; U.S. Naval Surface Warfare Center 
Panama City Division Mission Activities; Proposed Rule

  Federal Register / Vol. 74, No. 82 / Thursday, April 30, 2009 / 
Proposed Rules  

[[Page 20156]]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 218

RIN 0648-AW80


Taking and Importing Marine Mammals; U.S. Naval Surface Warfare 
Center Panama City Division Mission Activities

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

ACTION: Proposed rule; request for comments.

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SUMMARY: NMFS has received a request from the U.S. Navy (Navy) for 
authorization to take marine mammals incidental to Naval Surface 
Warfare Center Panama City Division (NSWC PCD) Research, Development, 
Test, and Evaluation (RDT&E) mission activities for the period of July 
2009 through July 2014. Pursuant to the Marine Mammal Protection Act 
(MMPA), NMFS is proposing regulations to govern that take and 
requesting information, suggestions, and comments on these proposed 
regulations.

DATES: Comments and information must be received no later than June 1, 
2009.

ADDRESSES: You may submit comments, identified by 0648-AW80, by any one 
of the following methods:
     Electronic Submissions: Submit all electronic public 
comments via the Federal eRulemaking Portal http://www.regulations.gov
     Hand delivery or mailing of paper, disk, or CD-ROM 
comments should be addressed to Michael Payne, Chief, Permits, 
Conservation and Education Division, Office of Protected Resources, 
National Marine Fisheries Service, 1315 East-West Highway, Silver 
Spring, MD 20910-3225.
    Instructions: All comments received are a part of the public record 
and will generally be posted to http://www.regulations.gov without 
change. All Personal Identifying Information (for example, name, 
address, etc.) voluntarily submitted by the commenter may be publicly 
accessible. Do not submit Confidential Business Information or 
otherwise sensitive or protected information.
    NMFS will accept anonymous comments (enter N/A in the required 
fields if you wish to remain anonymous). Attachments to electronic 
comments will be accepted in Microsoft Word, Excel, WordPerfect, or 
Adobe PDF file formats only.

FOR FURTHER INFORMATION CONTACT: Shane Guan, Office of Protected 
Resources, NMFS, (301) 713-2289, ext. 137.

SUPPLEMENTARY INFORMATION: 

Availability

    A copy of the Navy's application may be obtained by writing to the 
address specified above (See ADDRESSES), telephoning the contact listed 
above (see FOR FURTHER INFORMATION CONTACT), or visiting the internet 
at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm. The Navy's 
Draft Environmental Impact Statement (DEIS) for the NSWC PCD mission 
activities was published on April 4, 2008, and may be viewed at http://nswcpc.navsea.navy.mil/Environment-Documents.htm. NMFS participated in 
the development of the Navy's DEIS as a cooperating agency under the 
National Environmental Policy Act (NEPA).

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce (Secretary) to allow, upon request, 
the incidental, but not intentional taking of marine mammals by U.S. 
citizens who engage in a specified activity (other than commercial 
fishing) during periods of not more than five consecutive years each if 
certain findings are made and regulations are issued or, if the taking 
is limited to harassment, notice of a proposed authorization is 
provided to the public for review.
    Authorization shall be granted if NMFS finds that the taking will 
have a negligible impact on the species or stock(s), will not have an 
unmitigable adverse impact on the availability of the species or 
stock(s) for subsistence uses, and if the permissible methods of taking 
and requirements pertaining to the mitigation, monitoring and reporting 
of such taking are set forth. NMFS has defined ``negligible impact'' in 
50 CFR 216.103 as:

An impact resulting from the specified activity that cannot be 
reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.

    The National Defense Authorization Act of 2004 (NDAA) (Public Law 
108-136) removed the ``small numbers'' and ``specified geographical 
region'' limitations and amended the definition of ``harassment'' as it 
applies to a ``military readiness activity'' to read as follows 
(Section 3(18)(B) of the MMPA):

(i) Any act that injures or has the significant potential to injure 
a marine mammal or marine mammal stock in the wild [Level A 
Harassment]; or (ii) any act that disturbs or is likely to disturb a 
marine mammal or marine mammal stock in the wild by causing 
disruption of natural behavioral patterns, including, but not 
limited to, migration, surfacing, nursing, breeding, feeding, or 
sheltering, to a point where such behavioral patterns are abandoned 
or significantly altered [Level B Harassment].

Summary of Request

    On April 1, 2008, NMFS received an application, which was 
subsequently amended on February 12, 2009 with additional information, 
from the Navy requesting authorization for the take of 10 species of 
cetaceans incidental to the NSWC PCD RDT&E mission activities over the 
course of 5 years. These RDT&E activities are classified as military 
readiness activities. The Navy states that these RDT&E activities may 
cause various impacts to marine mammal species in the proposed action 
area (e.g., mortality, Level A and B harassment). The Navy requests an 
authorization to take individuals of these cetacean species by Level B 
Harassment. Further, the Navy requests authorization to take 2 
bottlenose dolphins, 2 Atlantic spotted dolphins, 1 pantropical spotted 
dolphin, and 1 spinner dolphin per year by Level A harassment (injury), 
as a result of the proposed mission activities. Please refer to Tables 
6-3, 6-4, 6-6, 6-7, 6-8, and 6-9 of the Letter of Authorization (LOA) 
Addendum for detailed information of the potential marine mammal 
exposures from the NSWC PCD mission activities per year. However, due 
to the proposed mitigation and monitoring measures, NMFS estimates that 
the take of marine mammals is likely to be lower than the amount 
requested. Although the Navy requests authorization to take marine 
mammals by mortality, NMFS does not expect any animals to be killed, 
and NMFS is not proposing to authorize any mortality incidental to the 
Navy's NSWC PCD mission activities.

Background of Navy Request

    The purpose of the proposed action is to enhance NSWC PCD's 
capability and capacity to meet littoral and expeditionary warfare 
requirements by providing RDT&E and in service engineering for 
expeditionary maneuver warfare, operations in extreme environments, 
mine warfare, maritime operations, and coastal operations.
    The need for the proposed action is for the Navy to successfully 
meet current and future national and global defense challenges by 
developing a robust capability to research, develop, test, and evaluate 
systems within the NSWC PCD Study Area. This capability allows the Navy 
to meet its statutory

[[Page 20157]]

mission to deploy worldwide naval forces equipped to meet existing and 
emergent threats and to enhance its ability to operate jointly with 
other components of the armed forces. NSWC PCD was established on the 
current site maintained by the Naval Support Activity Panama City (NSA 
PC) after a thorough site selection process in 1942. The Navy 
considered locations along the east coast and in the Gulf of Mexico 
(GOM). NSWC PCD provides:
     Accessibility to deep water
     Tests in clear water
     Conducive sand bottom
     Available land and sheltered areas, and
     Average good weather (year-round testing).
    In addition to these requirements for testing, the area was 
selected based on the moderate cost of living, the availability of 
personnel, and the low level of crowding from industries and 
development. In 1945, the station was re-commissioned as the U.S. Navy 
mine countermeasure station after its turnover as a section base for 
amphibious forces in 1944. The factors identified in 1942 during the 
selection process solidified the decision.
    NSWC PCD provides the greatest number of favorable circumstances 
needed to conduct RDT&E, in particular mine countermeasure exercises. 
Many of the other locations have large amounts of vessel traffic, rough 
waters and windy conditions, and closure of waterways seasonally due to 
water level. NSWC PCD has the established infrastructure, equipment, 
and personnel as well as the conditions required to fulfill the 
Proposed Action.
    The proposed mission activities involving sonar, ordnance and line 
charges, and projectile firing would occur in the NSWC PCD Study Area, 
which includes St. Andrew Bay (SAB) and military warning areas (areas 
within the Gulf of Mexico (GOM) subject to military operations) W-151 
(includes Panama City Operating Area), W-155 (includes Pensacola 
Operating Area), and W-470 (see Figures 2-1 and 2-2 of the LOA 
application). The NSWC PCD Study Area includes a Coastal Test Area, a 
Very Shallow Water Test Area, and Target and Operational Test Fields. 
The NSWC PCD RDT&E activities may be conducted anywhere within the 
existing military operating areas and SAB from the mean high water line 
(average high tide mark) out to 222 km (120 nm) offshore (see Figures 
2-1 and 2-2 of the LOA application). The locations and environments 
include:
     Test area control sites adjacent to NSWC PCD.
     Wide coastal shelf 97 km (52 nm) distance offshore to 183 
m (600 ft), including bays and harbors.
     Water temperature range of 27 [deg]C (80 [deg]F) in summer 
to 10 [deg]C (50[deg]F) in winter.
     Typically sandy bottom and good underwater visibility.
     Seas less than 0.91 m (3 ft) 80 percent of the time 
(summer) and less than 0.91 m (3 ft) 50 percent of the time (winter).

Description of the Specified Activities

    The purpose of the proposed action is to improve NSWC PCD's 
capabilities to conduct new and increased mission operations for the 
Department of the Navy (DON). NSWC PCD provides RDT&E and in-service 
support for expeditionary maneuver warfare, operations in extreme 
environments, mine warfare, maritime (ocean-related) operations, and 
coastal operations. A variety of naval assets, including vessels, 
aircraft, and underwater systems support these mission activities for 
eight primary test operations that occur within or over the water 
environment up to the high water mark. These operations include air, 
surface, and subsurface operations, sonar, electromagnetic energy, 
laser, ordnance, and projectile firing. Among these activities, surface 
operations, sonar, ordnance, and projectile firing may result in the 
incidental take of a marine mammal species or population stock, and are 
the focus of the Navy's LOA application and LOA Addendum. A detailed 
description of these operations is provided below.

Surface Operations

    The proposed NSWC PCD mission activities include up to 7,443 hours 
of surface operations per year in the NSWC PCD Study Area. Four 
subcategories make up surface operations.
    The first subcategory is support activities which are required by 
nearly all of the testing missions within the NSWC PCD Study Area. The 
size of these vessels varies according to test requirements and vessel 
availability. Often multiple surface crafts are required to support a 
single test event. Acting as a support platform for testing, these 
vessels are utilized to carry test equipment and personnel to and from 
the test sites and are also used to secure and monitor the designated 
test area. Normally, these vessels remain on site and return to port 
following the completion of the test; occasionally, however, they 
remain on-station throughout the duration of the test cycle for 
guarding sensitive equipment in the water. Testing associated with 
these operational capabilities may include a single test event or a 
series of test events spread out over consecutive days or as one long 
test operation that requires multiple days to complete.
    The remaining subcategories of additional support include tows, 
deployment and recovery of equipment, and systems development. Tows are 
also conducted from vessels at NSWC PCD to test system functionality. 
Tow tests of this nature involve either transporting the system to the 
designated test area where it is deployed and towed over a pre-
positioned inert minefield or towing the system from NSWC PCD to the 
designated test area. Surface vessels are also utilized as a tow 
platform for systems that are designed to be deployed by helicopters. 
Surface craft are also used to perform the deployment and recovery of 
underwater unmanned vehicles (UUVs), sonobuoys, inert mines, mine-like 
objects, versatile exercise mine systems, and other test systems. 
Surface vessels that are used in this manner normally return to port 
the same day. However, this is test dependent, and under certain 
circumstances (e.g., endurance testing), the vessel may be required to 
remain on site for an extended period of time. Finally, RDT&E 
activities also encompass testing of new, alternative, or upgraded 
hydrodynamics, and propulsion, navigational, and communication software 
and hardware systems.

Sonar Operations

    NSWC PCD sonar operations involve the testing of various sonar 
systems in the ocean and laboratory environment as a means of 
demonstrating the systems' software capability to detect, locate, and 
characterize mine-like objects under various environmental conditions. 
The data collected is used to validate the sonar system's effectiveness 
and capability to meet its mission.
    Based on frequency, the Navy has characterized low, mid, or high 
frequency sound sources as follows:
     Low frequency: Below 1 kHz
     Mid-frequency: From 1 to 10 kHz
     High frequency: Above 10 kHz
    Low frequency sonar is not proposed to be used during NSWC PCD 
operations. The various sonar systems proposed to be tested within the 
NSWC PCD Study Area range in frequencies of 1 kHz to 5 megahertz (MHz) 
(5,000 kHz). The source levels associated with NSWC PCD sonar systems 
that require analysis in this document based on the systems' parameters 
range from between 118 dB to 235 dB re 1 microPa at 1 m. The sonar 
systems tested are typically part of a towed array or hull mounted

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to a vessel. Additionally, subsystems associated with an underwater 
unmanned vehicle (UUV) or surf zone crawler operation are included. A 
detailed description of the frequency class and the reporting metric 
for each sonar system used at NSWC PCD can be found in Table A-1 of 
Appendix A, Supplemental Information for Underwater Noise Analysis, of 
the Navy's LOA application. Tables 1A and 1B present an overview of the 
number of operating hours annually for each of these sonar systems in 
territorial and non-territorial waters, respectively.

    Table 1A--Hours of Sonar Operations by Representative System for
                       Territorial Water Per Year
------------------------------------------------------------------------
                                                               Annual
                          System                              operating
                                                                hours
------------------------------------------------------------------------
AN/SQS-53/56 Kingfisher...................................           3
Sub-bottom profiler (2-9 kHz).............................          21
REMUS SAS-LF..............................................          12
REMUS Modem...............................................          25
Sub-bottom profiler (2-16 kHz)............................          24
AN/SQQ-32.................................................          30
REMUS-SAS-LF..............................................          20
SAS-LF....................................................          35
AN/WLD-1 RMS-ACL..........................................          33.5
BPAUV Sidescan............................................          25
TVSS......................................................          15
F84Y......................................................          15
BPAUV Sidescan............................................          25
REMUS-SAS-HF..............................................          10
SAS-HF....................................................          11.5
AN/AQS-20.................................................         545
AN/WLD-11 RMS Navigation..................................          15
BPAUV Sidescan............................................          30
------------------------------------------------------------------------


  Table 1B--Hours of Sonar Operations by Representative System for Non-
                       territorial Water Per Year
------------------------------------------------------------------------
                                                               Annual
                          System                              operating
                                                                hours
------------------------------------------------------------------------
AN/SQS-53/56 Kingfisher...................................           1
Sub-bottom profiler (2-9 kHz).............................           1
REMUS SAS-LF..............................................           0
REMUS Modem...............................................          12
Sub-bottom profiler (2-16 kHz)............................           1
AN/SQQ-32.................................................           1
REMUS-SAS-LF..............................................           0
SAS-LF....................................................          15
AN/WLD-1 RMS-ACL..........................................           5
BPAUV Sidescan............................................          38
TVSS......................................................          16.5
F84Y......................................................          15
BPAUV Sidescan............................................           0
REMUS-SAS-HF..............................................          25
SAS-HF....................................................          15
AN/AQS-20.................................................          15
AN/WLD-11 RMS Navigation..................................           0
BPAUV Sidescan............................................          25
------------------------------------------------------------------------

    Table 2 provides an overall summary of the total tempos associated 
with the proposed action. The table includes number of hours of 
operation per year for mid-frequency and high-frequency sonar testing 
activities for territorial and non-territorial waters, respectively. 
The ranges for the operations are given in the column, where 
appropriate. For example, sonar operations are divided into mid-
frequency and high-frequency ranges. The three columns to the left of 
the double vertical line contain the amount of operations for each 
subcategory conducted in territorial waters of the NSWC PCD Study Area. 
The values to the right of this demarcation, except those contained in 
the last column of the table, indicate the number of hours and/or 
operations that would occur in the non-territorial waters. The final 
column provides the total number of hours per year and/or operations in 
the NSWC PCD Study Area (or tempo in the territorial waters plus tempo 
in the non-territorial waters).

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[GRAPHIC] [TIFF OMITTED] TP30AP09.000

Ordnance Operations

    Ordnance operations include live testing of ordnance of various net 
explosive weights and line charges. The following subsections provide 
an overview of the events for ordnance and line charges, respectively.
1. Ordnance
    Live testing is only conducted after a system has successfully 
completed inert testing and an adequate amount of data has been 
collected to support the decision for live testing. Testing with live 
targets or ordnance is closely monitored and uses the minimum number of 
live munitions necessary to meet the testing requirement. Depending on 
the test scenario, live testing may occur from the surf zone out to the 
outer perimeter of the NSWC PCD Study Area. The Navy must develop its 
capability to conduct ordnance operations in shallow water to clear 
surf zone areas for sea-based expeditionary operations. The size and 
weight of the explosives used varies from 0.91 to 272 kg (2 to 600 lb) 
trinitrotoluene (TNT) equivalent net explosive weight (NEW) depending 
on the test requirements. For this document, ordnance was analyzed 
based on three ranges of NEW: 0.45 to 4.5 kg (1 to 10 lb), 5 to 34 kg 
(11 to 75 lb), and 34.5 to 272 kg (76 to 600 lb). Detonation of 
ordnance with a NEW less than 34.5 kg (76 lb) is conducted in 
territorial waters (with the exception of line charges and because of 
the need to use higher amounts of NEW to clear surf zone areas) and 
detonation of ordnance with a NEW greater than 34.5 kg (76 lb) is 
conducted in non-territorial waters.
2. Line Charges
    Line charges consist of a 107 m (350 ft) detonation cord with 
explosives lined from one end to the other end in 2 kg (5 lb) 
increments and total 794 kg (1,750 lb) of NEW. The charge is considered 
one explosive source that has multiple increments that detonate at one 
time. The energy released from line charges is comprised of a series of 
small detonations exploding sequentially rather than one simultaneous, 
large explosion. Therefore, they are treated as a series of small 
explosives rather than a large detonation. The Navy proposes to conduct 
up to three line charge events in the surf zone annually. Line charge 
testing would only be conducted in the surf zone along the portion of 
Santa Rosa Island that is part of Eglin Air Force Base (AFB). The Navy 
must develop its capability to safely clear surf zone areas for sea-
based expeditionary operations. To that end, NSWC PCD occasionally 
performs testing on various surf zone clearing systems that use line 
charges to neutralize mine threats. These tests are typically conducted 
from a surface vessel (e.g., Landing Craft Air Cushion [LCAC]) and are 
deployed using either a single or dual rocket launch scenario. This is 
a systems development test and only assesses the in-water components of 
testing.
    Table 2 also provides an overview of ordnance testing at NSWC PCD.

Projectile Firing

    Current projectile firing includes 50 rounds of 30-mm ammunition 
each year within the NSWC PCD Study Area. The ability to utilize 
gunfire during test operations was identified as a future requirement. 
Rounds (individual shots) identified include 5 inch, 20 mm, 25 mm, 30 
mm, 40 mm, 76 mm, and various small arms ammunition (i.e., standard 
target ammo). Projectiles associated with these rounds are mainly 
armor-piercing projectiles. The 5-in round is a high explosive (HE) 
projectile containing approximately 3.63 kg (8 lbs) of explosive 
material. Current projectile firing includes 50 rounds of 30-mm 
ammunition each year within the NSWC PCD Study Area. The preferred 
alternative would provide for increases in the number of 30-mm rounds 
as well as for expansion of projectile firing operations to 5 in, 20 
mm, 40 mm, 76 mm, 25 mm, and small arms ammunition. All projectile 
firing would occur over non-territorial waters.

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Description of Marine Mammals in the Area of the Specified Activities

    There are 30 marine mammal species with possible or confirmed 
occurrence in the NSWC PCD Study Area. As indicated in Table 3, there 
are 29 cetacean species (7 mysticetes and 22 odontocetes) and one 
sirenian species. Table 3 also includes the federal status of these 
marine mammal species. Seven marine mammal species listed as federally 
endangered under the Endangered Species Act (ESA) occur in the study 
area: The humpback whale, North Atlantic right whale, sei whale, fin 
whale, blue whale, sperm whale, and West Indian manatee. Of these 30 
species with occurrence records in the NSWC PCD Study Area, 22 species 
regularly occur here. These 22 species are: Bryde's whale, sperm whale, 
pygmy sperm whale, dwarf sperm whale, Cuvier's beaked whale, Gervais' 
beaked whale, Sowerby's beaked whale, Blainville's beaked whale, killer 
whale, false killer whale, pygmy killer whale, short-finned pilot 
whale, Risso's dolphin, melon-headed whale, rough-toothed dolphin, 
bottlenose dolphin, Atlantic spotted dolphin, pantropical spotted 
dolphin, striped dolphin, spinner dolphin, Clymene dolphin, and 
Fraser's dolphin. The remaining 8 species (i.e., North Atlantic right 
whale, humpback whale, sei whale, fin whale, blue whale, minke whale, 
True's beaked whale, and West Indian manatee) are extralimital and are 
excluded from further consideration of impacts from the NSWC PCD 
testing mission.

     Table 3--Marine Mammal Species Found in the NSWC PCD Study Area
------------------------------------------------------------------------
   Family and scientific name         Common name       Federal status
------------------------------------------------------------------------
Order Cetacea
------------------------------------------------------------------------
Suborder Mysticeti (baleen whales)
------------------------------------------------------------------------
Eubalaena glacialis.............  North Atlantic      Endangered.
                                   right whale.
Megaptera novaeangliae..........  Humpback whale....  Endangered.
Balaenoptera acutorostrata......  Minke whale.......  ..................
B. brydei.......................  Bryde's whale.....  ..................
B. borealis.....................  Sei whale.........  Endangered.
B. physalus.....................  Fin whale.........  Endangered.
B. musculus.....................  Blue whale........  Endangered.
------------------------------------------------------------------------
Suborder Odontoceti (toothed whales)
------------------------------------------------------------------------
Physeter macrocephalus..........  Sperm whale.......  Endangered.
Kogia breviceps.................  Pygmy sperm whale.  ..................
K. sima.........................  Dwarf sperm whale.  ..................
Ziphius cavirostris.............  Cuvier's beaked     ..................
                                   whale.
Mesoplodon europaeus............  Gervais' beaked     ..................
                                   whale.
M. Mirus........................  True's beaked       ..................
                                   whale.
M. bidens.......................  Sowerby's beaked    ..................
                                   whale.
M. densirostris.................  Blainville's        ..................
                                   beaked whale.
Steno bredanensis...............  Rough-toothed       ..................
                                   dolphin.
Tursiops truncatus..............  Bottlenose dolphin  ..................
Stenella attenuata..............  Pantropical         ..................
                                   spotted dolphin.
S. frontalis....................  Atlantic spotted    ..................
                                   dolphin.
S. longirostris.................  Spinner dolphin...  ..................
S. clymene......................  Clymene dolphin...  ..................
S. coeruleoalba.................  Striped dolphin...  ..................
Lagenodephis hosei..............  Fraser's dolphin..  ..................
Grampus griseus.................  Risso's dolphin...  ..................
Peponocephala electra...........  Melon-headed whale  ..................
Feresa attenuata................  Pygmy killer whale  ..................
Pseudorca crassidens............  False killer whale  ..................
Orcinus orca....................  Killer whale......  ..................
Globicephala melas..............  Long-finned pilot   ..................
                                   whale.
G. macrorhynchus................  Short-finned pilot  ..................
                                   whale.
------------------------------------------------------------------------
Order Sirenia
------------------------------------------------------------------------
Trichechus manatus..............  West Indian         Endangered.
                                   manatee.
------------------------------------------------------------------------

    The information contained herein relies heavily on the data 
gathered in the Marine Resource Assessments (MRAs). The Navy MRA 
Program was implemented by the Commander, Fleet Forces Command, to 
initiate collection of data and information concerning the protected 
and commercial marine resources found in the Navy's Operating Areas 
(OPAREAs). Specifically, the goal of the MRA program is to describe and 
document the marine resources present in each of the Navy's OPAREAs. 
The MRA for the NSWC PCD, which includes Pensacola and Panama City 
OPAREAs, was recently updated in 2007 (DoN, 2008).
    The MRA data were used to provide a regional context for each 
species. The MRA represents a compilation and synthesis of available 
scientific literature (for example, journals, periodicals, theses, 
dissertations, project reports, and other technical reports published 
by government agencies, private businesses, or consulting firms), and 
NMFS reports including stock assessment reports (SAR) (Waring et al., 
2007), which can be viewed at: http://www.nmfs.noaa.gov/pr/sars/species.htm.

[[Page 20161]]

    A detailed description of marine mammal density estimates in the 
NSWC PCD Study Area is provided in the Navy's LOA application and LOA 
Addendum.

A Brief Background on Sound

    An understanding of the basic properties of underwater sound is 
necessary to comprehend many of the concepts and analyses presented in 
this document. A summary is included below.
    Sound is a wave of pressure variations propagating through a medium 
(for the sonar considered in this proposed rule, the medium is marine 
water). Pressure variations are created by compressing and relaxing the 
medium. Sound measurements can be expressed in two forms: intensity and 
pressure. Acoustic intensity is the average rate of energy transmitted 
through a unit area in a specified direction and is expressed in watts 
per square meter (W/m\2\). Acoustic intensity is rarely measured 
directly, it is derived from ratios of pressures; the standard 
reference pressure for underwater sound is 1 microPascal (microPa); for 
airborne sound, the standard reference pressure is 20 microPa (Urick, 
1983).
    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 microPa or, for airborne sound, 20 
microPa). The logarithmic nature of the scale means that each 10 dB 
increase is a tenfold increase in power (e.g., 20 dB is a 100-fold 
increase, 30 dB is a 1,000-fold increase). Humans perceive a 10-dB 
increase in noise as a doubling of sound level, or a 10 dB decrease in 
noise as a halving of sound level. 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 microPa 
as a standard reference pressure unless noted otherwise.
    It is important to note that decibels underwater and decibels in 
air are not the same and cannot be directly compared. To estimate a 
comparison between sound in air and underwater, because of the 
different densities of air and water and the different decibel 
standards (i.e., reference pressures) in water and air, a sound with 
the same intensity (i.e., power) in air and in water would be 
approximately 63 dB lower in air. Thus, a sound that is 160 dB loud 
underwater would have the same approximate effective intensity as a 
sound that is 97 dB loud in air.
    Sound frequency is measured in cycles per second, or Hertz 
(abbreviated Hz), and is analogous to musical pitch; high-pitched 
sounds contain high frequencies and low-pitched sounds contain low 
frequencies. Natural sounds in the ocean span a huge range of 
frequencies: from earthquake noise at 5 Hz to harbor porpoise clicks at 
150,000 Hz (150 kHz). These sounds are so low or so high in pitch that 
humans cannot even hear them; acousticians call these infrasonic and 
ultrasonic 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''; airguns are an example of a 
broadband sound source and tactical sonars are an example of a 
narrowband sound source.
    When considering the influence of various kinds of sound on the 
marine environment, it is necessary to understand that different kinds 
of marine life are sensitive to different frequencies of sound. Based 
on available behavioral data, audiograms derived using auditory evoked 
potential, anatomical modeling, and other data, Southall et al. (2007) 
designate ``functional hearing groups'' and estimate the lower and 
upper frequencies of functional hearing of the groups. Further, the 
frequency range in which each group's hearing is estimated as being 
most sensitive is represented in the flat part of the M-weighting 
functions developed for each group. The functional groups and the 
associated frequencies are indicated below:
     Low frequency cetaceans (13 species of mysticetes): 
Functional hearing is estimated to occur between approximately 7 Hz and 
22 kHz.
     Mid-frequency cetaceans (32 species of dolphins, six 
species of larger toothed whales, and 19 species of beaked and 
bottlenose whales): Functional hearing is estimated to occur between 
approximately 150 Hz and 160 kHz.
     High frequency cetaceans (eight species of true porpoises, 
six species of river dolphins, Kogia, the franciscana, and four species 
of cephalorhynchids): Functional hearing is estimated to occur between 
approximately 200 Hz and 180 kHz.
     Pinnipeds in Water: Functional hearing is estimated to 
occur between approximately 75 Hz and 75 kHz, with the greatest 
sensitivity between approximately 700 Hz and 20 kHz.
     Pinnipeds in Air: Functional hearing is estimated to occur 
between approximately 75 Hz and 30 kHz.
    Because ears adapted to function underwater are physiologically 
different from human ears, comparisons using decibel measurements in 
air would still not be adequate to describe the effects of a sound on a 
whale. When sound travels away from its source, its loudness decreases 
as the distance traveled (propagates) by the sound increases. Thus, the 
loudness of a sound at its source is higher than the loudness of that 
same sound a kilometer distant. Acousticians often refer to the 
loudness of a sound at its source (typically measured one meter from 
the source) as the source level and the loudness of sound elsewhere as 
the received level. For example, a humpback whale three kilometers from 
an airgun that has a source level of 230 dB may only be exposed to 
sound that is 160 dB loud, depending on how the sound propagates. As a 
result, it is important not to confuse source levels and received 
levels when discussing the loudness of sound in the ocean.
    As sound travels from a source, its propagation in water is 
influenced by various physical characteristics, including water 
temperature, depth, salinity, and surface and bottom properties that 
cause refraction, reflection, absorption, and scattering of sound 
waves. Oceans are not homogeneous and the contribution of each of these 
individual factors is extremely complex and interrelated. The physical 
characteristics that determine the sound's speed through the water will 
change with depth, season, geographic location, and with time of day 
(as a result, in actual sonar operations, crews will measure oceanic 
conditions, such as sea water temperature and depth, to calibrate 
models that determine the path the sonar signal will take as it travels 
through the ocean and how strong the sound signal will be at a given 
range along a particular transmission path). As sound travels through 
the ocean, the intensity associated with the wavefront diminishes, or 
attenuates. This decrease in intensity is referred to as propagation 
loss, also commonly called transmission loss.

Metrics Used in This Document

    This section includes a brief explanation of the two sound 
measurements (sound pressure level (SPL) and sound exposure level 
(SEL)) frequently used in the discussions of acoustic effects in this 
document.
SPL
    Sound pressure is the sound force per unit area, and is usually 
measured in microPa, where 1 Pa is the pressure

[[Page 20162]]

resulting from a force of one newton exerted over an area of one square 
meter. SPL is expressed as the ratio of a measured sound pressure and a 
reference level. The commonly used reference pressure level in 
underwater acoustics is 1 microPa, and the units for SPLs are dB re: 1 
microPa.

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

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

SEL = SPL + 10log(duration in seconds)

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

Potential Impacts to Marine Mammal Species

    The Navy considers that the proposed NSWC PCD mission activities 
associated with surface operations, sonar, ordnance, and projectile 
firing operations are the activities with the potential to result in 
Level A or Level B harassment or mortality of marine mammals. The 
following sections discuss the potential for ship strikes to occur from 
surface operations, potential effects from noise related to sonar, 
potential effects from noise related to ordnance, potential effects 
from noise related to projectile firing operations, and direct physical 
impacts from projectile firing.

Surface Operations

    Typical operations occurring at the surface include the deployment 
or towing of mine countermeasures (MCM) equipment, retrieval of 
equipment, and clearing and monitoring for non-participating vessels. 
As such, the potential exists for a ship to strike a marine mammal 
while conducting surface operations. In an effort to reduce the 
likelihood of a vessel strike, the mitigation and monitoring measures 
discussed below would be implemented.
Surface Operations in Territorial Waters
    Collisions with commercial and U.S. Navy vessels can cause major 
wounds and may occasionally cause fatalities to marine mammals. 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). Laist et al. (2001) 
identified 11 species known to be hit by ships worldwide. Of these 
species, fin whales are struck most frequently; followed by right 
whales, humpback whales, sperm whales, and gray whales. More 
specifically, from 1975 through 1996, there were 31 dead whale 
strandings involving four large whales along the GOM coastline. 
Stranded animals included two sei whales, four minke whales, eight 
Bryde's whales, and 17 sperm whales. Only one of the stranded animals, 
a sperm whale with propeller wounds found in Louisiana on 9 March 1990, 
was identified as a result of a possible ship strike (Laist et al., 
2001). In addition, from 1999 through 2003, there was only one 
stranding involving a false killer whale in the northern GOM (Alabama 
1999) (Waring et al., 2006). None of these identified species are 
likely to occur in the territorial waters of the NSWC PCD Study Area. 
This area encompasses waters that are less than 33 m (108 ft) in depth 
and it is unlikely any species, including Bryde's whales are located 
here.
    It is unlikely that activities in territorial waters will result in 
a vessel strike because of the nature of the operations and size of the 
vessels. For example, the hours of surface operations take into 
consideration operation times for multiple vessels during each test 
event. These vessels range in size from small rigid hull inflatable 
boat (RHIB) to surface vessels of approximately 180 ft (55 m). The 
majority of these vessels are small RHIBs and medium-sized vessels. A 
large proportion of the timeframe for NSWC PCD test events include 
periods when vessels remain stationary within the test site. The 
greatest time spent in transit for tests includes navigation to and 
from the sites. At these times, the Navy follows standard operating 
procedures (SOPs). The captain and other crew members keep watch during 
vessel transits to avoid objects in the water. Furthermore, with the 
implementation of the proposed mitigation and monitoring measures 
described below, NMFS believes that it is unlikely vessel strikes would 
occur. Consequently, because of the nature of the surface operations 
and the size of the vessels, the proposed mitigation and monitoring 
measures, and the fact that cetaceans typically more vulnerable to ship 
strikes are not likely to be in the project area, the NMFS concludes 
that ship strikes are unlikely to occur in territorial waters.
Surface Operations in Non-Territorial Waters
    As stated above, there have been two reports of possible 
watercraft-related cetacean deaths in the GOM. These deaths include one 
sperm whale found with propeller wounds in Louisiana in March 1990 and 
one false killer whale in Alabama in 1999 (Laist et al., 2001; Waring 
et al., 2007). According to the 2008 SAR, no other marine mammal that 
is likely to occur in the northern GOM has been reported as either 
seriously or fatally injured from a ship strike between 1999 through 
2003 (Waring et al., 2007). The nature of operations, size of vessels 
and standard operating procedures to minimize the risk of vessel 
collisions will be similar to those expected to occur in territorial 
waters. Moreover, the implementation of additional mitigation and 
monitoring measures will reduce further the probability of a vessel 
strike. Thus, NMFS concludes that the potential effects to marine 
mammals from surface operations in non-territorial waters will be 
similar to those described for territorial waters.

Acoustic Effects: Exposure to Sonar

    For activities involving active tactical sonar, underwater 
detonations, and projectile firing, NMFS's analysis will identify the 
probability of lethal responses, physical trauma, sensory impairment 
(permanent and temporary threshold shifts and acoustic masking), 
physiological responses (particular stress responses), behavioral 
disturbance (that rises to the level of harassment), and social 
responses that would be classified as behavioral harassment or injury 
and/or would be likely to adversely affect the species or

[[Page 20163]]

stock through effects on annual rates of recruitment or survival. In 
this section, we will focus qualitatively on the different ways that 
mid-frequency active sonar (MFAS) and high frequency active sonar 
(HFAS), ordnance, and projectile firing may affect marine mammals (some 
of which NMFS would not classify as harassment). Then, in the Estimated 
Take of Marine Mammals section, NMFS will relate the potential effects 
to marine mammals from HFAS/MFAS, ordnance, and projectile firing to 
the MMPA regulatory definitions of Level A and Level B Harassment and 
attempt to quantify those effects.

Direct Physiological Effects

    Based on the literature, there are two basic ways that HFAS/MFAS 
might directly result in physical trauma or damage: Noise-induced loss 
of hearing sensitivity (more commonly-called ``threshold shift'') and 
acoustically mediated bubble growth. Separately, an animal's behavioral 
reaction to an acoustic exposure might lead to physiological effects 
that might ultimately lead to injury or death, which is discussed later 
in the Stranding section.

Threshold Shift (Noise-Induced Loss of Hearing)

    When animals exhibit reduced hearing sensitivity (i.e., sounds must 
be louder for an animal to recognize them) following exposure to a 
sufficiently intense sound, it is referred to as a noise-induced 
threshold shift (TS). An animal can experience temporary threshold 
shift (TTS) or permanent threshold shift (PTS). TTS can last from 
minutes or hours to days (i.e., there is recovery), occurs in specific 
frequency ranges (i.e., an animal might only have a temporary loss of 
hearing sensitivity between the frequencies of 1 and 10 kHz), and can 
be of varying amounts (for example, an animal's hearing sensitivity 
might be reduced by only 6 dB or reduced by 30 dB). PTS is permanent 
(i.e., there is no recovery), but also occurs in a specific frequency 
range and amount as mentioned in the TTS description.
    The following physiological mechanisms are thought to play a role 
in inducing auditory TSs: Effects to sensory hair cells in the inner 
ear that reduce their sensitivity, modification of the chemical 
environment within the sensory cells, residual muscular activity in the 
middle ear, displacement of certain inner ear membranes, increased 
blood flow, and post-stimulatory reduction in both efferent and sensory 
neural output (Southall et al., 2007). The amplitude, duration, 
frequency, temporal pattern, and energy distribution of sound exposure 
all affect the amount of associated TS and the frequency range in which 
it occurs. As amplitude and duration of sound exposure increase, so, 
generally, does the amount of TS. For continuous sounds, exposures of 
equal energy (the same SEL) will lead to approximately equal effects. 
For intermittent sounds, less TS will occur than from a continuous 
exposure with the same energy (some recovery will occur between 
exposures) (Kryter et al., 1966; Ward, 1997). For example, one short 
but loud (higher SPL) sound exposure may induce the same impairment as 
one longer but softer sound, which in turn may cause more impairment 
than a series of several intermittent softer sounds with the same total 
energy (Ward, 1997). Additionally, though TTS is temporary, very 
prolonged exposure to sound strong enough to elicit TTS, or shorter-
term exposure to sound levels well above the TTS threshold, can cause 
PTS, at least in terrestrial mammals (Kryter, 1985) (although in the 
case of HFAS/MFAS, animals are not expected to be exposed to levels 
high enough or durations long enough to result in PTS).
    PTS is considered auditory injury (Southall et al., 2007). 
Irreparable damage to the inner or outer cochlear hair cells may cause 
PTS, however, other mechanisms are also involved, such as exceeding the 
elastic limits of certain tissues and membranes in the middle and inner 
ears and resultant changes in the chemical composition of the inner ear 
fluids (Southall et al., 2007).
    Although the published body of scientific literature contains 
numerous theoretical studies and discussion papers on hearing 
impairments that can occur with exposure to a loud sound, only a few 
studies provide empirical information on the levels at which noise-
induced loss in hearing sensitivity occurs in nonhuman animals. For 
cetaceans, published data are limited to the captive bottlenose dolphin 
and beluga whale (Finneran et al., 2000, 2002b, 2005a; Schlundt et al., 
2000; Nachtigall et al., 2003, 2004).
    Marine mammal hearing plays a critical role in communication with 
conspecifics, and interpreting environmental cues for purposes such as 
predator avoidance and prey capture. Depending on the frequency range 
of TTS degree (dB), duration, and frequency range of TTS, and the 
context in which it is experienced, TTS can have effects on marine 
mammals ranging from discountable to serious (similar to those 
discussed in auditory masking, below). For example, a marine mammal may 
be able to readily compensate for a brief, relatively small amount of 
TTS in a non-critical frequency range that takes place during a time 
when the animal is traveling through the open ocean, where ambient 
noise is lower and there are not as many competing sounds present.
    Alternatively, a larger amount and longer duration of TTS sustained 
during time when communication is critical for successful mother/calf 
interactions could have more serious impacts. Also, depending on the 
degree and frequency range, the effects of PTS on an animal could range 
in severity, although it is considered generally more serious because 
it is a long term condition. Of note, reduced hearing sensitivity as a 
simple function of development and aging has been observed in marine 
mammals, as well as humans and other taxa (Southall et al., 2007), so 
we can infer that strategies exist for coping with this condition to 
some degree, though likely not without cost. There is no empirical 
evidence that exposure to HFAS/MFAS can cause PTS in any marine 
mammals; instead the probability of PTS has been inferred from studies 
of TTS (see Richardson et al., 1995).

Acoustically Mediated Bubble Growth

    One theoretical cause of injury to marine mammals is rectified 
diffusion (Crum and Mao, 1996), the process of increasing the size of a 
bubble by exposing it to a sound field. This process could be 
facilitated if the environment in which the ensonified bubbles exist is 
supersaturated with gas. Repetitive diving by marine mammals can cause 
the blood and some tissues to accumulate gas to a greater degree than 
is supported by the surrounding environmental pressure (Ridgway and 
Howard, 1979). The deeper and longer dives of some marine mammals (for 
example, beaked whales) are theoretically predicted to induce greater 
supersaturation (Houser et al., 2001b). 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 would be long 
enough to drive bubble growth to any substantial size, if such a 
phenomenon occurs. Recent work conducted by Crum et al. (2005) 
demonstrated the possibility of rectified diffusion for short duration

[[Page 20164]]

signals, but at sound exposure levels and tissue saturation levels that 
are improbable to occur in a diving marine mammal. However, an 
alternative but related hypothesis has also been suggested: Stable 
bubbles could be destabilized by high-level sound exposures such that 
bubble growth then occurs through static diffusion of gas out of the 
tissues. In such a scenario the marine mammal would need to be in a 
gas-supersaturated state for a long enough period of time for bubbles 
to become of a problematic size. Yet another hypothesis (decompression 
sickness) has speculated that rapid ascent to the surface following 
exposure to a startling sound might produce tissue gas saturation 
sufficient for the evolution of nitrogen bubbles (Jepson et al., 2003; 
Fernandez et al., 2005). In this scenario, the rate of ascent would 
need to be sufficiently rapid to compromise behavioral or physiological 
protections against nitrogen bubble formation. Collectively, these 
hypotheses can be referred to as ``hypotheses of acoustically mediated 
bubble growth.''
    Although theoretical predictions suggest the possibility for 
acoustically mediated bubble growth, there is considerable disagreement 
among scientists as to its likelihood (Piantadosi and Thalmann, 2004; 
Evans and Miller, 2003). Crum and Mao (1996) hypothesized that received 
levels would have to exceed 190 dB in order for there to be the 
possibility of significant bubble growth due to supersaturation of 
gases in the blood (i.e., rectified diffusion). More recent work 
conducted by Crum et al. (2005) demonstrated the possibility of 
rectified diffusion for short duration signals, but at SELs and tissue 
saturation levels that are highly improbable to occur in diving marine 
mammals. To date, Energy Levels (ELs) predicted to cause in vivo bubble 
formation within diving cetaceans have not been evaluated (NOAA, 
2002b). Although it has been argued that traumas from some recent 
beaked whale strandings are consistent with gas emboli and bubble-
induced tissue separations (Jepson et al., 2003), there is no 
conclusive evidence of this. However, Jepson et al. (2003, 2005) and 
Fernandez et al. (2004, 2005) concluded that in vivo bubble formation, 
which may be exacerbated by deep, long duration, repetitive dives may 
explain why beaked whales appear to be particularly vulnerable to sonar 
exposures. Further investigation is needed to further assess the 
potential validity of these hypotheses. More information regarding 
hypotheses that attempt to explain how behavioral responses to HFAS/
MFAS can lead to strandings is included in the Behaviorally Mediated 
Bubble Growth section, after the summary of strandings.
Acoustic Masking
    Marine mammals use acoustic signals for a variety of purposes, 
which differ among species, but include communication between 
individuals, navigation, foraging, reproduction, and learning about 
their environment (Erbe and Farmer, 2000; Tyack, 2000). Masking, or 
auditory interference, generally occurs when sounds in the environment 
are louder than and of a similar frequency 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. (1995) argued that the maximum radius of 
influence of an industrial noise (including broadband low frequency 
sound transmission) on a marine mammal is the distance from the source 
to the point at which the noise can barely be heard. This range is 
determined by either the hearing sensitivity of the animal or the 
background noise level present. Industrial masking is most likely to 
affect some species' ability to detect communication calls and natural 
sounds (i.e., surf noise, prey noise, etc.; Richardson et al., 1995).
    The echolocation calls of odontocetes (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).
    As mentioned previously, the functional hearing ranges of 
mysticetes (baleen whales) and odontocetes (toothed whales) all 
encompass the frequencies of the sonar sources used in the Navy's RDT&E 
activities. Additionally, almost all species' vocal repertoires span 
across the frequencies of the 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. However, because the 
pulse length and duty cycle of the HFAS/MFAS signal are of short 
duration and would not be continuous, masking is unlikely to occur as a 
result of exposure to HFAS/MFAS during the mission activities in the 
NSWC PCD Study Area.
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 are more important than 
detecting a vocalization (Brenowitz, 1982; Brumm et al., 2004; Dooling, 
2004; Marten and Marler, 1977; Patricelli et al., 2006). Most animals 
that vocalize have evolved an ability to make vocal adjustments to 
their vocalizations to increase the signal-to-noise ratio, active 
space, and recognizability of their vocalizations in the face of 
temporary changes in background noise (Brumm et al., 2004; Patricelli 
et al., 2006). Vocalizing animals will make one or more of the 
following adjustments to their vocalizations: Adjust the frequency 
structure; adjust the amplitude; adjust temporal structure; or adjust 
temporal delivery.
    Many animals will combine several of these strategies to compensate 
for high levels of background noise. Anthropogenic sounds that reduce 
the signal-to-noise ratio of animal

[[Page 20165]]

vocalizations, increase the masked auditory thresholds of animals 
listening for such vocalizations, or reduce the active space of an 
animal's vocalizations impair communication between animals. Most 
animals that vocalize have evolved strategies to compensate for the 
effects of short-term or temporary increases in background or ambient 
noise on their songs or calls. Although the fitness consequences of 
these vocal adjustments remain unknown, like most other trade-offs 
animals must make, some of these strategies probably come at a cost 
(Patricelli et al., 2006). For example, vocalizing more loudly in noisy 
environments may have energetic costs that decrease the net benefits of 
vocal adjustment and alter a bird's energy budget (Brumm, 2004; Wood 
and Yezerinac, 2006). Shifting songs and calls to higher frequencies 
may also impose energetic costs (Lambrechts, 1996).
Stress Responses
    Classic stress responses begin when an animal's central nervous 
system perceives a potential threat to its homeostasis. That perception 
triggers stress responses regardless of whether a stimulus actually 
threatens the animal; the mere perception of a threat is sufficient to 
trigger a stress response (Moberg, 2000; Sapolsky et al., 2005; Seyle, 
1950). Once an animal's central nervous system perceives a threat, it 
mounts a biological response or defense that consists of a combination 
of the four general biological defense responses: Behavioral responses, 
autonomic nervous system responses, neuroendocrine responses, or immune 
response.
    In the case of many stressors, an animal's first and most 
economical (in terms of biotic costs) response is behavioral avoidance 
of the potential stressor or avoidance of continued exposure to a 
stressor. An animal's second line of defense to stressors involves the 
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 effects on 
an animal's welfare.
    An animal's third line of defense to stressors involves its 
neuroendocrine or sympathetic nervous systems; the system that has 
received the most study has been the hypothalamus-pituitary-adrenal 
system (also known as the HPA axis in mammals or the hypothalamus-
pituitary-interrenal axis in fish and some reptiles). Unlike stress 
responses associated with the autonomic nervous system, virtually all 
neuro-endocrine functions that are affected by stress--including immune 
competence, reproduction, metabolism, and behavior--are regulated by 
pituitary hormones. Stress-induced changes in the secretion of 
pituitary hormones have been implicated in failed reproduction (Moberg, 
1987; Rivier, 1995) and altered metabolism (Elasser et al., 2000), 
reduced immune competence (Blecha, 2000) and behavioral disturbance. 
Increases in the circulation of glucocorticosteroids (cortisol, 
corticosterone, and aldosterone in marine mammals; Romano et al., 2004) 
have been equated with stress for many years.
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and distress is the biotic cost 
of the response. During a stress response, an animal uses glycogen 
stores that can be quickly replenished once the stress is alleviated. 
In such circumstances, the cost of the stress response would not pose a 
risk to the animal's welfare. However, when an animal does not have 
sufficient energy reserves to satisfy the energetic costs of a stress 
response, energy resources must be diverted from other biotic 
functions, which impair those functions that experience the diversion. 
For example, when mounting a stress response diverts energy away from 
growth in young animals, those animals may experience stunted growth. 
When mounting a stress response diverts energy from a fetus, an 
animal's reproductive success and its fitness will suffer. In these 
cases, the animals will have entered a pre-pathological or pathological 
state which is called ``distress'' (sensu Seyle, 1950) or ``allostatic 
loading'' (sensu McEwen and Wingfield, 2003). This pathological state 
will last until the animal replenishes its biotic reserves sufficient 
to restore normal function.
    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). Although no information has been collected on the physiological 
responses of marine mammals to exposure to anthropogenic sounds, 
studies of other marine animals and terrestrial animals would lead us 
to expect some marine mammals to experience physiological stress 
responses and, perhaps, physiological responses that would be 
classified as ``distress'' upon exposure to mid-frequency and low 
frequency sounds.
    For example, Jansen (1998) reported on the relationship between 
acoustic exposures and physiological responses that are indicative of 
stress responses in humans (for example, elevated respiration and 
increased heart rates). Jones (1998) reported on reductions in human 
performance when faced with acute, repetitive exposures to acoustic 
disturbance. Trimper et al. (1998) reported on the physiological stress 
responses of osprey to low-level aircraft noise while Krausman et al. 
(2004) reported on the auditory and physiology stress responses of 
endangered Sonoran pronghorn to military overflights. Smith et al. 
(2004a, 2004b) identified noise induced physiological transient stress 
responses in hearing-specialist fish 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 cetaceans 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 
cetaceans 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

[[Page 20166]]

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. Exposure of marine mammals to sound sources can result in 
(but is not limited to) the following observable responses: Increased 
alertness; orientation or attraction to a sound source; vocal 
modifications; cessation of feeding; cessation of social interaction; 
alteration of movement or diving behavior; habitat abandonment 
(temporary or permanent); and, in severe cases, panic, flight, 
stampede, or stranding, potentially resulting in death (Southall et 
al., 2007).
    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 type affects whether it is less likely 
(habituation) or more likely (sensitization) to respond to certain 
sounds in the future (animals can also be innately pre-disposed to 
respond to certain sounds in certain ways) (Southall et al., 2007). 
Related to the sound itself, the perceived nearness of the sound, 
bearing of the sound (approaching vs. retreating), similarity of a 
sound to biologically relevant sounds in the animal's environment 
(i.e., calls of predators, prey, or conspecifics), and familiarity of 
the sound may affect the way an animal responds to the sound (Southall 
et al., 2007). Individuals (of different age, gender, reproductive 
status, etc.) among most populations will have variable hearing 
capabilities, and differing behavioral sensitivities to sounds that 
will be affected by prior conditioning, experience, and current 
activities of those individuals. Often, specific acoustic features of 
the sound and contextual variables (i.e., proximity, duration, or 
recurrence of the sound or the current behavior that the marine mammal 
is engaged in or its prior experience), as well as entirely separate 
factors such as the physical presence of a nearby vessel, may be more 
relevant to the animal's response than the received level alone.
    There are few empirical studies of avoidance responses of free-
living cetaceans to mid-frequency sonars. Much more information is 
available on the avoidance responses of free-living cetaceans to other 
acoustic sources, like seismic airguns and low frequency sonar, than 
mid-frequency active sonar. Richardson et al., (1995) noted that 
avoidance reactions are the most obvious manifestations of disturbance 
in marine mammals.

Behavioral Responses (Southall et al. (2007))

    Southall et al., (2007) reports the results of the efforts of a 
panel of experts in acoustic research from behavioral, physiological, 
and physical disciplines that convened and reviewed the available 
literature on marine mammal hearing and physiological and behavioral 
responses to man-made sound with the goal of proposing exposure 
criteria for certain effects. This compilation of literature is very 
valuable, though Southall et al. note that not all data is 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.
    In the Southall et al., (2007) report, 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. HFAS/MFAS sonar is 
considered a non-pulse sound. Southall et al., (2007) summarize the 
reports associated with low, mid, and high frequency cetacean responses 
to non-pulse sounds (there are no pinnipeds in the Gulf of Mexico 
(GOM)) in Appendix C of their report (incorporated by reference and 
summarized in the three paragraphs below).
    The reports 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 HFAS/MFAS) 
including: Vessel noise, drilling and machinery playback, low frequency 
M-sequences (sine wave with multiple phase reversals) playback, low 
frequency active sonar playback, drill vessels, Acoustic Thermometry of 
Ocean Climate (ATOC) source, and non-pulse playbacks. These reports 
generally indicate no (or very limited) responses to received levels in 
the 90 to 120 dB re 1 micro Pa range and an increasing likelihood of 
avoidance and other behavioral effects in the 120 to 160 dB range. As 
mentioned earlier, however, 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 reports 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 HFAS/MFAS) including: Pingers, drilling playbacks, vessel 
and ice-breaking noise, vessel noise, Acoustic Harassment Devices 
(AHDs), Acoustic Deterrent Devices (ADDs), HFAS/MFAS, and non-pulse 
bands and tones. Southall et al. were unable to come to a clear 
conclusion regarding these reports. 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 responded at lower levels in the field).
    The reports that address the 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 HFAS/MFAS) including: acoustic harassment devices, 
Acoustical Telemetry of Ocean Climate (ATOC), wind turbine, vessel 
noise, and construction noise. However, no conclusive results are 
available from these reports. In some cases, high frequency cetaceans 
(harbor porpoises) are observed to be quite sensitive to a wide range 
of human sounds at very low exposure RLs (90 to 120 dB). All recorded 
exposures exceeding 140 dB produced profound and sustained avoidance 
behavior in wild harbor porpoises (Southall et al., 2007).
    In addition to summarizing the available data, the authors of 
Southall et al. (2007) developed a severity scaling system with the 
intent of ultimately being able to assign some level of biological 
significance to a response. Following is a summary of their scoring 
system, a comprehensive list of the behaviors associated with each 
score may be found in the report:
     0-3 (Minor and/or brief behaviors) includes, but is not 
limited to: No response; minor changes in speed or locomotion (but with 
no avoidance); individual alert behavior; minor cessation in vocal 
behavior; minor changes in response to trained behaviors (in 
laboratory).
     4-6 (Behaviors with higher potential to affect foraging, 
reproduction, or survival) includes, but is not limited to: Moderate 
changes in speed, direction, or dive profile; brief shift in group 
distribution; prolonged cessation or modification of vocal behavior 
(duration > duration of sound),

[[Page 20167]]

minor or moderate individual and/or group avoidance of sound; brief 
cessation of reproductive behavior; or refusal to initiate trained 
tasks (in laboratory).
     7-9 (Behaviors considered likely to affect the 
aforementioned vital rates) includes, but are not limited to: Extensive 
of prolonged aggressive behavior; moderate, prolonged or significant 
separation of females and dependent offspring with disruption of 
acoustic reunion mechanisms; long-term avoidance of an area; outright 
panic, stampede, stranding; threatening or attacking sound source (in 
laboratory).
    In Table 4 we have summarized the scores that Southall et al. 
(2007) assigned to the papers that reported behavioral responses of low 
frequency cetaceans, mid-frequency cetaceans, and high frequency 
cetaceans to non-pulse sounds.
[GRAPHIC] [TIFF OMITTED] TP30AP09.001

Potential Effects of Behavioral Disturbance

    The different ways that marine mammals respond to sound are 
sometimes indicators of the ultimate effect that exposure to a given 
stimulus will have on the well-being (survival, reproduction, etc.) of 
an animal. There is little marine mammal data quantitatively relating 
the exposure of marine mammals to sound to effects on reproduction or 
survival, though data exists for terrestrial species to which we can 
draw comparisons for marine mammals.
    Attention is the cognitive process of selectively concentrating on 
one aspect of an animal's environment while ignoring other things 
(Posner, 1994). Because animals (including humans) have limited 
cognitive resources, there is a limit to how much sensory information 
they can process at any time. The phenomenon called ``attentional 
capture'' occurs when a stimulus (usually a stimulus that an animal is 
not concentrating on or attending to) ``captures'' an animal's 
attention. This shift in attention can occur consciously or 
unconsciously (for example, when an animal hears sounds that it 
associates with the approach of a predator) and the shift in attention 
can be sudden (Dukas, 2002; van Rij, 2007). Once a stimulus has 
captured an animal's attention, the animal can respond by ignoring the 
stimulus, assuming a ``watch and wait'' posture, or treat the stimulus 
as a disturbance and respond accordingly, which includes scanning for 
the source of the stimulus or ``vigilance'' (Cowlishaw et al., 2004).
    Vigilance is normally an adaptive behavior that helps animals 
determine the presence or absence of predators, assess their distance 
from conspecifics, or to attend cues from prey (Bednekoff and 
Lima,1998; Treves, 2000). Despite those benefits, however, vigilance 
has a cost of time: When animals focus their attention on specific 
environmental cues, they are not attending to other activities such a 
foraging. These costs have been documented best in foraging animals, 
where vigilance has been shown to substantially reduce feeding rates 
(Saino, 1994; Beauchamp and Livoreil, 1997; Fritz et al., 2002).
    Animals will spend more time being vigilant, which may translate to 
less time foraging or resting, when disturbance stimuli approach them 
more directly, remain at closer distances, have a greater group size 
(for example, multiple surface vessels), or when they co-occur with 
times that an animal perceives increased risk (for example, when they 
are giving birth or accompanied by a calf). Most of the published 
literature, however, suggests that direct approaches will increase the 
amount of time animals will dedicate to being vigilant. For example, 
bighorn sheep and Dall's sheep dedicated more time being vigilant, and 
less time resting or foraging, when aircraft made direct approaches 
over them (Frid, 2001; Stockwell et al., 1991).
    Several authors have established that long-term and intense 
disturbance stimuli can cause population declines by reducing the body 
condition of individuals that have been disturbed, followed by reduced 
reproductive success, reduced survival, or both (Daan et al., 1996; 
Madsen, 1994; White, 1983). For example, Madsen (1994) reported that 
pink-footed geese (Anser brachyrhynchus) in undisturbed habitat gained 
body mass and had about a 46-percent reproductive success compared with 
geese in disturbed habitat (being

[[Page 20168]]

consistently scared off the fields on which they were foraging) which 
did not gain mass and has a 17 percent reproductive success. Similar 
reductions in reproductive success have been reported for mule deer 
(Odocoileus hemionus) disturbed by all-terrain vehicles (Yarmoloy et 
al., 1988), caribou disturbed by seismic exploration blasts (Bradshaw 
et al., 1998), caribou disturbed by low-elevation military jetfights 
(Luick et al., 1996), and caribou disturbed by low-elevation jet 
flights (Harrington and Veitch, 1992). Similarly, a study of elk 
(Cervus elaphus) that were disturbed experimentally by pedestrians 
concluded that the ratio of young to mothers was inversely related to 
disturbance rate (Phillips and Alldredge, 2000).
    The primary mechanism by which increased vigilance and disturbance 
appear to affect the fitness of individual animals is by disrupting an 
animal's time budget and, as a result, reducing the time they might 
spend foraging and resting (which increases an animal's activity rate 
and energy demand). For example, a study of grizzly bears (Ursus 
horribilis) reported that bears disturbed by hikers reduced their 
energy intake by an average of 12 kcal/min (50.2 x 103kJ/min), and 
spent energy fleeing or acting aggressively toward hikers (White et 
al., 1999).
    On a related note, many animals perform vital functions, such as 
feeding, resting, traveling, and socializing, on a diel cycle (24-hr. 
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 one day 
and not recurring on subsequent days is not considered particularly 
severe unless it could directly affect reproduction or survival 
(Southall et al., 2007).

Stranding and Mortality

    When a live or dead marine mammal swims or floats onto shore and 
becomes ``beached'' or incapable of returning to sea, the event is 
termed a ``stranding'' (Geraci et al., 1999; Perrin and Geraci, 2002; 
Geraci and Lounsbury, 2005; NMFS, 2007). The legal definition for a 
stranding within the United States is that ``a marine mammal is dead 
and is (i) on a beach or shore of the United States; or (ii) in waters 
under the jurisdiction of the United States (including any navigable 
waters); or (B) a marine mammal is alive and is (i) on a beach or shore 
of the United States and is unable to return to the water; (ii) on a 
beach or shore of the United States and, although able to return to the 
water, is in need of apparent medical attention; or (iii) in the waters 
under the jurisdiction of the United States (including any navigable 
waters), but is unable to return to its natural habitat under its own 
power or without assistance.'' (16 U.S.C. 1421h).
    Marine mammals are known to strand for a variety of reasons, such 
as infectious agents, biotoxicosis, starvation, fishery interaction, 
ship strike, unusual oceanographic or weather events, sound exposure, 
or combinations of these stressors sustained concurrently or in series. 
However, the cause or causes of most stranding 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 these phenomena. These 
suggestions are consistent with the conclusions of numerous other 
studies that have demonstrated that combinations of dissimilar 
stressors commonly combine to kill an animal or dramatically reduce its 
fitness, even though one exposure without the other does not produce 
the same result (Chroussos, 2000; Creel, 2005; DeVries et al., 2003; 
Fair and Becker, 2000; Foley et al., 2001; Moberg, 2000; Relyea, 2005a; 
2005b, Romero, 2004; Sih et al., 2004).
    Several sources have published lists of mass stranding events of 
cetaceans during attempts to identify relationships between those 
stranding events and military sonar (Hildebrand, 2004; IWC, 2005; 
Taylor et al., 2004). For example, based on a review of stranding 
records between 1960 and 1995, the International Whaling Commission 
(IWC, 2005) identified ten mass stranding events of Cuvier's beaked 
whales that had been reported and one mass stranding of four Baird's 
beaked whales (Berardius bairdii). The IWC concluded that, out of eight 
stranding events reported from the mid-1980s to the summer of 2003, 
seven had been associated with the use of mid-frequency sonar, one of 
those seven had been associated with the use of low frequency sonar, 
and the remaining stranding event had been associated with the use of 
seismic airguns.
    Most of the stranding events reviewed by the IWC involved beaked 
whales. A mass stranding of Cuvier's beaked whales in the eastern 
Mediterranean Sea occurred in 1996 (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 that were using sonar.
    Between 1960 and 2006, 48 strandings (68 percent) involved beaked 
whales, 3 (4 percent) involved dolphins, and 14 (20 percent) involved 
other whale species. Cuvier's beaked whales were involved in the 
greatest number of these events (48 or 68 percent), followed by sperm 
whales (7 or 10 percent), and Blainville's and Gervais' beaked whales 
(4 each or 6 percent). Naval activities that might have involved active 
sonar are reported to have coincided with 9 (13 percent) or 10 (14 
percent) of those stranding events. Between the mid-1980s and 2003 (the 
period reported by the IWC), we identified reports of 44 mass cetacean 
stranding events of which at least 7 were coincident with naval 
exercises that were using mid-frequency sonar. A list of stranding 
events that are considered to be associated with MFAS is presented in 
the proposed rulemaking for the Navy's training in the Hawaii Range 
Complex (73 FR 35510; June 23, 2008).

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 vessels transmitting mid-frequency sonar (Cox et al., 2006, D'Spain 
et al., 2006). However, only 77 hours of the proposed NSWC PCD RDT&E 
activities would involve the use of mid-frequency sonar. Of the mid-
frequency sonar sources proposed to be used per year, only 4 hours 
would be associated with the highest powered surface vessel source (AN/
SQS-53/56). The remaining mid-frequency sonar sources do not have 
strong source levels, therefore, their zones of influence are much 
smaller compared to these highest powered surface vessel sources, and 
animals can be more easily detected, thereby increasing the probability 
that sonar operations can be modified to reduce the risk of injury to 
marine mammals. In addition, the proposed test events differ

[[Page 20169]]

significantly from major Navy exercises and training which involve 
multi-vessel training scenarios using the AN/SQS-53/56 source that have 
been associated with past strandings. In contrast, the majority of 
sonar operations (1,277 hours) would be using high-frequency sonar. 
Source levels of the HFAS are not as high as the 53C series MFAS or 
other proposed MFAS sources. In addition, high frequency signals tend 
to have more attenuation in the water column and are more prone to lose 
their energy during propagation. Therefore, their zones of influence 
are much smaller and are less likely to affect marine mammals. Although 
Cuvier's beaked whales have been the most common species involved in 
these stranding events (81 percent of the total number of stranded 
animals and see Figure 1), 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 available evidence, however, we cannot determine 
whether (a) Cuvier's beaked whale is more prone to injury from high-
intensity sound than other species, (b) their behavioral responses to 
sound makes them more likely to strand, or (c) they are more likely to 
be exposed to mid-frequency active sonar than other cetaceans (for 
reasons that remain unknown). Because the association between active 
sonar (mid-frequency) exposures and marine mammal 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 HFAS/MFAS That May Lead to Stranding

    Although the confluence of Navy mid-frequency active tactical sonar 
with the other contributory factors noted in the report was identified 
as the cause of the 2000 Bahamas stranding event, the specific 
mechanisms that led to that stranding (or the others) are not 
understood, and there is uncertainty regarding the ordering of effects 
that led to the stranding. It is unclear whether beaked whales were 
directly injured by sound (acoustically mediated bubble growth, 
addressed above) prior to stranding or whether a behavioral response to 
sound occurred that ultimately caused the beaked whales to be injured 
and 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 two mechanisms by which the behavioral responses of 
beaked whales upon being exposed to active sonar might result in a 
stranding event. These include: gas bubble formation caused by 
excessively fast surfacing; remaining at the surface too long when 
tissues are supersaturated with nitrogen; or diving prematurely when 
extended time at the surface is necessary to eliminate excess nitrogen. 
More specifically, beaked whales that occur in deep waters that are in 
close proximity to shallow waters (for example, the ``canyon areas'' 
that are cited in the Bahamas stranding event; see D'Spain and D'Amico, 
2006), may respond to active sonar by swimming into shallow waters to 
avoid further exposures and strand if they were not able to swim back 
to deeper waters. Second, beaked whales exposed to active sonar might 
alter their dive behavior. Changes in their dive behavior might cause 
them to remain at the surface or at depth for extended periods of time, 
which could lead to hypoxia directly by increasing their oxygen demands 
or indirectly by increasing their energy expenditures (to remain at 
depth) 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 with (2) relatively slow, controlled 
ascents, followed by (3) a series of ``bounce'' dives between 100 and 
400 m (328 and 1,323 ft) in depth (also see Zimmer and Tyack, 2007). 
They concluded that acoustic exposures that disrupted any part of this 
dive sequence (for example, causing beaked whales to spend more time at 
surface without the bounce dives that are necessary to recover from the 
deep dive) could produce excessive levels of nitrogen supersaturation 
in their tissues, leading to gas bubble and emboli formation that 
produces pathologies similar to decompression sickness.
    Recently, Zimmer and Tyack (2007) modeled nitrogen tension and 
bubble growth in several tissue compartments for several hypothetical 
dive profiles and concluded that repetitive shallow dives (defined as a 
dive where depth does not exceed the depth of alveolar collapse, 
approximately 72 m (236 ft) 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

[[Page 20170]]

of the response. Their models also suggested that unrealistically more 
rapid ascent rates 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 midfrequency range sonar (Jepson et al., 2003; Fernandez et al., 
2005) could stem from a behavioral response that involves repeated 
dives shallower than the depth of lung collapse. Given that nitrogen 
gas accumulation is a passive process (i.e., nitrogen is metabolically 
inert), a bottlenose dolphin was trained to repetitively dive a profile 
predicted to elevate nitrogen saturation to the point that nitrogen 
bubble formation was predicted to occur. However, inspection of the 
vascular system of the dolphin via ultrasound did not demonstrate the 
formation of asymptomatic nitrogen gas bubbles (Houser et al., 2007).
    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 vessel is, therefore, closer) and as vessel 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) summarize that 
scientific disagreement or complete lack of information exists 
regarding 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.
    Unlike those past stranding events that were coincident with 
military mid-frequency sonar use and were speculated to most likely 
have been caused by exposure to the sonar, those naval exercises 
involved multiple vessels in waters with steep bathymetry where deep 
channeling of sonar signals was more likely. The proposed NSWC PCD 
RDT&E activities would not involve multi-vessel operations and the 
bathymetry has none of the similarities where those mass strandings 
occurred. (e.g., Greece (1996); the Bahamas (2000); Madeira (2000); 
Canary Islands (2002); Hanalei Bay, Kaua'I, Hawaii (2004); and Spain 
(2006)). Consequently, because of the nature of the NSWC PCD operations 
(which involve low total hours of MFAS use, very limited use of high-
powered surface vessel source, and no high-speed, multi-vessel training 
scenarios) and the fact that the NSWC PCD has none of the bathymetric 
features that have been associated with mass strandings in the past, 
NMFS concludes it is unlikely that sonar use would result in a 
stranding event in the NSWC PCD region.

Acoustic Effects: Exposure to Ordnance and Projectile Firing

    Some of the Navy's RDT&E activities include the underwater 
detonation of explosives. For many of the exercises discussed, inert 
ordnance is used for a subset of the exercises. The underwater 
explosion from a weapon would send a shock wave and blast noise through 
the water, release gaseous by-products, create an oscillating bubble, 
and cause a plume of water to shoot up from the water surface. The 
shock wave and blast 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 worse 
impacts to an individual animal.
    Injuries resulting from a shock wave take place at boundaries 
between tissues of different density. Different velocities are imparted 
to tissues of different densities, and this can lead to their physical 
disruption. Blast effects are greatest at the gas-liquid interface 
(Landsberg, 2000). Gas-containing organs, particularly the lungs and 
gastrointestinal tract, are especially susceptible (Goertner, 1982; 
Hill, 1978; Yelverton et al., 1973). In addition, gas-containing organs 
including the nasal sacs, larynx, pharynx, trachea, and lungs may be 
damaged by compression/expansion caused by the oscillations of the 
blast gas bubble (Reidenberg and Laitman, 2003). Intestinal walls can 
bruise or rupture, with subsequent hemorrhage and escape of gut 
contents into the body cavity. Less severe gastrointestinal tract 
injuries include contusions, petechiae (small red or purple spots 
caused by bleeding in the skin), and slight hemorrhaging (Yelverton et 
al., 1973).
    Because the ears are the most susceptible to changes in pressure, 
they are the organs most sensitive to injury (Ketten, 2000). Sound-
related damage associated with blast noise can be theoretically 
distinct from injury from the shock wave, particularly farther from the 
explosion. If an animal is able to hear a noise, at some level it can 
damage its hearing by causing decreased sensitivity (Ketten, 1995) (See 
Noise-induced Threshold Shift Section above). Sound-related trauma can 
be lethal or sublethal. Lethal impacts are those that result in 
immediate death or serious debilitation in or near an intense source 
and are not, technically, pure acoustic trauma (Ketten, 1995). 
Sublethal impacts include hearing loss, which is caused by exposures to 
perceptible sounds. Severe damage (from the shock wave) to the ears 
includes tympanic membrane rupture, fracture of the ossicles, damage to 
the cochlea, hemorrhage, and cerebrospinal fluid leakage into the 
middle ear. Moderate injury implies partial hearing loss due to 
tympanic membrane rupture and blood in the middle ear. Permanent 
hearing loss also can occur when the hair cells are damaged by one very 
loud event, as well as by prolonged exposure to a loud noise or chronic 
exposure to noise. The level of impact from blasts depends on both an 
animal's location and, at outer zones, on its sensitivity to the 
residual noise (Ketten, 1995).
    There have been fewer studies addressing the behavioral effects of 
explosives on marine mammals than HFAS/MFAS. However, though the nature 
of the sound waves emitted from an explosion is different (in shape and

[[Page 20171]]

rise time) from HFAS/MFAS, we still anticipate the same sorts of 
behavioral responses (see Exposure to HFAS/MFAS: Behavioral Disturbance 
Section) to result from repeated explosive detonations (a smaller range 
of likely less severe responses would be expected to occur as a result 
of exposure to a single explosive detonation).
Estimated Take of Marine Mammals
    With respect to the MMPA, NMFS' effects assessment serves 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 Level A or B 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 will have a negligible 
impact on the affected species or stocks of marine mammals (based on 
the likelihood that the activity will adversely affect the species or 
stock through effects on annual rates of recruitment or survival); (3) 
to determine whether the specified activity will have an unmitigable 
adverse impact on the availability of the species or stock(s) for 
subsistence uses (however, there are no subsistence communities that 
would be affected in the NSWC PCD Study Area, so this determination is 
inapplicable for this rulemaking); and (4) to prescribe requirements 
pertaining to monitoring and reporting.
    In the Potential Effects of Exposure of Marine Mammal to HFAS/MFAS 
and Underwater Detonations sections, NMFS identifies the lethal 
responses, physical trauma, sensory impairment (permanent and temporary 
threshold shifts and acoustic masking), physiological responses 
(particular stress responses), and behavioral responses that could 
potentially result from exposure to HFAS/MFAS or underwater explosive 
detonations. In this section, we will relate the potential effects to 
marine mammals from HFAS/MFAS and underwater detonation of explosives 
to the MMPA regulatory definitions of Level A and Level B Harassment 
and attempt to quantify the effects that might occur from the specific 
RDT&E activities that the Navy is proposing in the NSWC PCD.

Definition of Harassment

    As mentioned previously, with respect to military readiness 
activities, Section 3(18)(B) of the MMPA defines ``harassment'' as: (i) 
Any act that injures or has the significant potential to injure a 
marine mammal or marine mammal stock in the wild [Level A Harassment]; 
or (ii) any act that disturbs or is likely to disturb a marine mammal 
or marine mammal stock in the wild by causing disruption of natural 
behavioral patterns, including, but not limited to, migration, 
surfacing, nursing, breeding, feeding, or sheltering, to a point where 
such behavioral patterns are abandoned or significantly altered [Level 
B Harassment].
Level B Harassment
    Of the potential effects that were described in the Potential 
Effects of Exposure of Marine Mammals to HFAS/MFAS and Underwater 
Detonations sections, the following are the types of effects that fall 
into the Level B Harassment category:
    Behavioral Harassment--Behavioral disturbance that rises to the 
level described in the definition above, when resulting from exposures 
to HFAS/MFAS or underwater detonations, is considered Level B 
Harassment. Some of the lower level physiological stress responses will 
also likely co-occur with the predicted harassments, although these 
responses are more difficult to detect and fewer data exist relating 
these responses to specific received levels of sound. When Level B 
Harassment is predicted based on estimated behavioral responses, those 
takes may have a stress-related physiological component as well.
    In the effects section above, we described the Southall et al., 
(2007) severity scaling system and listed some examples of the three 
broad categories of behaviors: (0-3: Minor and/or brief behaviors); 4-6 
(Behaviors with higher potential to affect foraging, reproduction, or 
survival); 7-9 (Behaviors considered likely to affect the 
aforementioned vital rates). Generally speaking, MMPA Level B 
Harassment, as defined in this document, would include the behaviors 
described in the 7-9 category, and a subset, dependent on context and 
other considerations, of the behaviors described in the 4-6 categories. 
Behavioral harassment generally does not include behaviors ranked 0-3 
in Southall et al., (2007).
    Acoustic Masking and Communication Impairment--Acoustic masking is 
considered Level B Harassment as it can disrupt natural behavioral 
patterns by interrupting or limiting the marine mammal's receipt or 
transmittal of important information or environmental cues.
    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 either HFAS/MFAS or underwater detonations) as Level B 
Harassment, not Level A Harassment (injury).
Level A Harassment
    Of the potential effects that were described in the Potential 
Effects of Exposure of Marine Mammal to HFAS/MFAS and Underwater 
Detonations Section, following are the types of effects that fall into 
the Level A Harassment category:
    PTS--PTS (resulting either from exposure to HFAS/MFAS 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 results in 
changes in the chemical composition of the inner ear fluids.
    Acoustically Mediated Bubble Growth--A few theories suggest ways in 
which gas bubbles become enlarged through exposure to intense sounds 
(HFAS/MFAS) to the point where tissue damage results. In rectified 
diffusion, exposure to a sound field would cause bubbles to increase in 
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. Tissue damage from either of these processes 
would be considered an injury.
    Behaviorally Mediated Bubble Growth--Several authors suggest 
mechanisms in which marine mammals could behaviorally respond to 
exposure to HFAS/MFAS by altering their dive

[[Page 20172]]

patterns in a manner (unusually rapid ascent, unusually long series of 
surface dives, etc.) that might result in unusual bubble formation or 
growth ultimately resulting in tissue damage (emboli, etc.).
    Physical Disruption of Tissues Resulting from Explosive Shock 
Wave--Physical damage of tissues resulting from a shock wave (from an 
explosive detonation) is classified as an injury. Blast effects are 
greatest at the gas-liquid interface (Landsberg, 2000) and gas-
containing organs, particularly the lungs and gastrointestinal tract, 
are especially susceptible (Goertner, 1982; Hill 1978; Yelverton et 
al., 1973). Nasal sacs, larynx, pharynx, trachea, and lungs may be 
damaged by compression/expansion caused by the oscillations of the 
blast gas bubble (Reidenberg and Laitman, 2003). Severe damage (from 
the shock wave) to the ears can include tympanic membrane rupture, 
fracture of the ossicles, damage to the cochlea, hemorrhage, and 
cerebrospinal fluid leakage into the middle ear.

Acoustic Take Criteria

    For the purposes of an MMPA incidental take authorization, three 
types of take are identified: Level B harassment; Level A harassment; 
and mortality (or serious injury leading to mortality). The categories 
of marine mammal responses (physiological and behavioral) that fall 
into the two harassment categories were described in the previous 
section.
    Because the physiological and behavioral responses of the majority 
of the marine mammals exposed to HFAS/MFAS and underwater detonations 
cannot be detected or measured, 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 uses acoustic criteria that 
estimate at what received level (when exposed to HFAS/MFAS or explosive 
detonations) Level B Harassment, Level A Harassment, and mortality (for 
explosives) of marine mammals would occur. The acoustic criteria for 
HFAS/MFAS and Underwater Detonations are discussed below.

HFAS/MFAS Acoustic Criteria

    Because relatively few applicable data exist to support acoustic 
criteria specifically for HFAS, and it is suspected that the majority 
of the adverse affects are from the MFAS due to their larger impact 
ranges, NMFS will apply the criteria developed for the MFAS to the HFAS 
as well.
    NMFS utilizes three acoustic criteria for HFAS/MFAS: PTS (injury--
Level A Harassment), behavioral harassment from TTS, and sub-TTS (Level 
B Harassment). Because the TTS and PTS criteria are derived similarly 
and the PTS criteria was extrapolated from the TTS data, the TTS and 
PTS acoustic criteria will be presented first, before the behavioral 
criteria.
    For more information regarding these criteria, please see the 
Navy's DEIS for the NSWC PCD.

Level B Harassment Threshold (TTS)

    As mentioned above, behavioral disturbance, acoustic masking, and 
TTS are all considered Level B Harassment. Marine mammals would usually 
be behaviorally disturbed at lower received levels than those at which 
they would likely sustain TTS, so the levels at which behavioral 
disturbance is likely to occur are considered the onset of Level B 
Harassment. The behavioral responses of marine mammals to sound are 
variable, context specific, and, therefore, difficult to quantify (see 
Risk Function section, below). TTS is a physiological effect that has 
been studied and quantified in laboratory conditions. NMFS also uses an 
acoustic criteria to estimate the number of marine mammals that might 
sustain TTS incidental to a specific activity (in addition to the 
behavioral criteria).
    A number of investigators have measured TTS in marine mammals. 
These studies measured hearing thresholds in trained marine mammals 
before and after exposure to intense sounds. The existing cetacean TTS 
data are summarized in the following bullets.
     Schlundt et al. (2000) reported the results of TTS 
experiments conducted with 5 bottlenose dolphins and 2 belugas exposed 
to 1-second tones. This paper also includes a reanalysis of preliminary 
TTS data released in a technical report by Ridgway et al. (1997). At 
frequencies of 3, 10, and 20 kHz, sound pressure levels (SPLs) 
necessary to induce measurable amounts (6 dB or more) of TTS were 
between 192 and 201 dB re 1 microPa (EL = 192 to 201 dB re 1 
microPa\2\-s). The mean exposure SPL and EL for onset-TTS were 195 dB 
re 1 microPa and 195 dB re 1 microPa\2\-s, respectively.
     Finneran et al. (2001, 2003, 2005) described TTS 
experiments conducted with bottlenose dolphins exposed to 3-kHz tones 
with durations of 1, 2, 4, and 8 seconds. Small amounts of TTS (3 to 6 
dB) were observed in one dolphin after exposure to ELs between 190 and 
204 dB re 1 microPa\2\-s. These results were consistent with the data 
of Schlundt et al. (2000) and showed that the Schlundt et al. (2000) 
data were not significantly affected by the masking sound used. These 
results also confirmed that, for tones with different durations, the 
amount of TTS is best correlated with the exposure EL rather than the 
exposure SPL.
     Nachtigall et al. (2003) measured TTS in a bottlenose 
dolphin exposed to octave-band sound centered at 7.5 kHz. Nachtigall et 
al. (2003a) reported TTSs of about 11 dB measured 10 to 15 minutes 
after exposure to 30 to 50 minutes of sound with SPL 179 dB re 1 
microPa (EL about 213 dB re microPa\2\-s). No TTS was observed after 
exposure to the same sound at 165 and 171 dB re 1 microPa. Nachtigall 
et al. (2004) reported TTSs of around 4 to 8 dB 5 minutes after 
exposure to 30 to 50 minutes of sound with SPL 160 dB re 1 microPa (EL 
about 193 to 195 dB re 1 microPa\2\-s). The difference in results was 
attributed to faster post-exposure threshold measurement--TTS may have 
recovered before being detected by Nachtigall et al. (2003). These 
studies showed that, for long duration exposures, lower sound pressures 
are required to induce TTS than are required for short-duration tones.
     Finneran et al. (2000, 2002) conducted TTS experiments 
with dolphins and belugas exposed to impulsive sounds similar to those 
produced by distant underwater explosions and seismic waterguns. These 
studies showed that, for very short-duration impulsive sounds, higher 
sound pressures were required to induce TTS than for longer-duration 
tones.
    Some of the more important data obtained from these studies are 
onset-TTS levels (exposure levels sufficient to cause a just-measurable 
amount of TTS) often defined as 6 dB of TTS (for example, Schlundt et 
al., 2000) and the fact that energy metrics (sound exposure levels 
(SEL), which include a duration component) better predict when an 
animal will sustain TTS than pressure (SPL) alone. NMFS' TTS criteria 
(which indicate the received level at which onset TTS (>6dB) is 
induced) for HFAS/MFAS are as follows:
     Cetaceans--195 dB re 1 microPa\2\-s (based on mid-
frequency cetaceans--no published data exist on auditory effects of 
noise in low or high frequency cetaceans (Southall et al., 2007).
    A detailed description of how TTS criteria were derived from the 
results of the above studies may be found in Chapter 3 of Southall et 
al. (2007), as well as the Navy's NSWC PCD LOA application.

Level A Harassment Threshold (PTS)

    For acoustic effects, because the tissues of the ear appear to be 
the most

[[Page 20173]]

susceptible to the physiological effects of sound, and because 
threshold shifts tend to occur at lower exposures than other more 
serious auditory effects, NMFS has determined that PTS is the best 
indicator for the smallest degree of injury that can be measured. 
Therefore, the acoustic exposure associated with onset-PTS is used to 
define the lower limit of the Level A harassment.
    PTS data do not currently exist for marine mammals and are unlikely 
to be obtained due to ethical concerns. However, PTS levels for these 
animals may be estimated using TTS data from marine mammals and 
relationships between TTS and PTS that have been discovered through 
study of terrestrial mammals. NMFS uses the following acoustic criteria 
for injury:
     Cetaceans--215 dB re 1 microPa \2\-s (based on mid-
frequency cetaceans--no published data exist on auditory effects of 
noise in low or high frequency cetaceans (Southall et al., 2007).
    These criteria are based on a 20 dB increase in SEL over that 
required for onset-TTS. Extrapolations from terrestrial mammal data 
indicate that PTS occurs at 40 dB or more of TS, and that TS growth 
occurs at a rate of approximately 1.6 dB TS per dB increase in EL. 
There is a 34-dB TS difference between onset-TTS (6 dB) and onset-PTS 
(40 dB). Therefore, an animal would require approximately 20-dB of 
additional exposure (34 dB divided by 1.6 dB) above onset-TTS to reach 
PTS. A detailed description of how TTS criteria were derived from the 
results of the above studies may be found in Chapter 3 of Southall et 
al. (2007), as well as the Navy's NSWC PCD LOA application. Southall et 
al. (2007) recommend a precautionary dual criteria for TTS (230 dB re 1 
microPa (SPL) in addition to 215 re 1 microPa \2\-s (SEL)) to account 
for the potentially damaging transients embedded within non-pulse 
exposures. However, in the case of HFAS/MFAS, the distance at which an 
animal would receive 215 (SEL) is farther from the source than the 
distance at which they would receive 230 (SPL) and therefore, it is not 
necessary to consider 230 dB.
    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.

Level B Harassment Risk Function (Behavioral Harassment)

    The first MMPA authorization for take of marine mammals incidental 
to tactical active sonar was issued in 2006 for Navy Rim of the Pacific 
training exercises in Hawaii. For that authorization, NMFS used 173 dB 
SEL as the criterion for the onset of behavioral harassment (Level B 
Harassment). This type of single number criterion is referred to as a 
step function, in which (in this example) all animals estimated to be 
exposed to received levels above 173 dB SEL would be predicted to be 
taken by Level B Harassment and all animals exposed to less than 173 dB 
SEL would not be taken by Level B Harassment. As mentioned previously, 
marine mammal behavioral responses to sound are highly variable and 
context specific (affected by differences in acoustic conditions; 
differences between species and populations; differences in gender, 
age, reproductive status, or social behavior; or the prior experience 
of the individuals), which does not support the use of a step function 
to estimate behavioral harassment.
    Unlike step functions, acoustic risk continuum functions (which are 
also called ``exposure-response functions,'' ``dose-response 
functions,'' or ``stress response functions'' in other risk assessment 
contexts) allow for probability of a response that NMFS would classify 
as harassment to occur over a range of possible received levels 
(instead of one number) and assume that the probability of a response 
depends first on the ``dose'' (in this case, the received level of 
sound) and that the probability of a response increases as the ``dose'' 
increases. The Navy and NMFS have previously used acoustic risk 
functions to estimate the probable responses of marine mammals to 
acoustic exposures in the Navy FEISs on the SURTASS LFA sonar (DoN, 
2001c) and the North Pacific Acoustic Laboratory experiments conducted 
off the Island of Kauai (ONR, 2001). The specific risk functions used 
here were also used in the MMPA regulations and FEIS for Hawaii Range 
Complex (HRC), Southern California Range Complex (SOCAL), and Atlantic 
Fleet Active Sonar Testing (AFAST). As discussed in the Effects 
section, factors other than received level (such as distance from or 
bearing to the sound source) can affect the way that marine mammals 
respond; however, data to support a quantitative analysis of those (and 
other factors) do not currently exist. NMFS will continue to modify 
these criteria as new data become available.
    To assess the potential effects on marine mammals associated with 
active sonar used during training activity the Navy and NMFS applied a 
risk function that estimates the probability of behavioral responses 
that NMFS would classify as harassment for the purposes of the MMPA 
given exposure to specific received levels of MFA sonar. The 
mathematical function is derived from a solution in Feller (1968) as 
defined in the SURTASS LFA Sonar Final OEIS/EIS (DoN, 2001), and relied 
on in the Supplemental SURTASS LFA Sonar EIS (DoN, 2007a) for the 
probability of MFA sonar risk for MMPA Level B behavioral harassment 
with input parameters modified by NMFS for MFA sonar for mysticetes and 
odontocetes (NMFS, 2008). The same risk function and input parameters 
will be applied to high frequency active (HFA) (<10 kHz) sources until 
applicable data becomes available for high frequency sources.
    In order to represent a probability of risk, the function should 
have a value near zero at very low exposures, and a value near one for 
very high exposures. One class of functions that satisfy this criterion 
is cumulative probability distributions, a type of cumulative 
distribution function. In selecting a particular functional expression 
for risk, several criteria were identified:
     The function must use parameters to focus discussion on 
areas of uncertainty;
     The function should contain a limited number of 
parameters;
     The function should be capable of accurately fitting 
experimental data; and
     The function should be reasonably convenient for algebraic 
manipulations.
    As described in U.S. Department of the Navy (2001), the 
mathematical function below is adapted from a solution in Feller 
(1968).
[GRAPHIC] [TIFF OMITTED] TP30AP09.003

Where:
R = Risk (0-1.0)
L = Received level (dB re: 1 [micro]Pa)
B = Basement received level = 120 dB re: 1 [micro]Pa
K = Received level increment above B where 50 percent risk = 45 dB 
re: 1 [micro]Pa
A = Risk transition sharpness parameter = 10 (odontocetes) or 8 
(mysticetes)
    In order to use this function to estimate the percentage of an 
exposed population that would respond in a manner that NMFS classifies 
as Level B harassment, based on a given received level, the values for 
B, K and A need to be identified.

[[Page 20174]]

    B Parameter (Basement)--The B parameter is the estimated received 
level below which the probability of disruption of natural behavioral 
patterns, such as migration, surfacing, nursing, breeding, feeding, or 
sheltering, to a point where such behavioral patterns are abandoned or 
significantly altered approaches zero for the HFAS/MFAS risk 
assessment. At this received level, the curve would predict that the 
percentage of the exposed population that would be taken by Level B 
Harassment approaches zero. For HFAS/MFAS, NMFS has determined that B = 
120 dB. This level is based on a broad overview of the levels at which 
many species have been reported responding to a variety of sound 
sources.
    K Parameter (representing the 50 percent Risk Point)--The K 
parameter is based on the received level that corresponds to 50 percent 
risk, or the received level at which we believe 50 percent of the 
animals exposed to the designated received level will respond in a 
manner that NMFS classifies as Level B Harassment. The K parameter (K = 
45 dB) is based on three datasets in which marine mammals exposed to 
mid-frequency sound sources were reported to respond in a manner that 
NMFS would classify as Level B Harassment. There is widespread 
consensus that marine mammal responses to HFA/MFA sound signals need to 
be better defined using controlled exposure experiments (Cox et al., 
2006; Southall et al., 2007). The Navy is contributing to an ongoing 
behavioral response study in the Bahamas that is expected to provide 
some initial information on beaked whales, the species identified as 
the most sensitive to MFAS. NMFS is leading this international effort 
with scientists from various academic institutions and research 
organizations to conduct studies on how marine mammals respond to 
underwater sound exposures. Until additional data is available, 
however, NMFS and the Navy have determined that the following three 
data sets are most applicable for the direct use in establishing the K 
parameter for the HFAS/MFAS risk function. These data sets, summarized 
below, represent the only known data that specifically relate altered 
behavioral responses (that NMFS would consider Level B Harassment) to 
exposure to HFAS/MFAS sources.
    Even though these data are considered the most representative of 
the proposed specified activities, and therefore the most appropriate 
on which to base the K parameter (which basically determines the 
midpoint) of the risk function, these data have limitations, which are 
discussed in Appendix J of the Navy's EIS for the NSWC PCD .
    1. Controlled Laboratory Experiments with Odontocetes (SSC 
Dataset)--Most of the observations of the behavioral responses of 
toothed whales resulted from a series of controlled experiments on 
bottlenose dolphins and beluga whales conducted by researchers at SSC's 
facility in San Diego, California (Finneran et al., 2001, 2003, 2005; 
Finneran and Schlundt, 2004; Schlundt et al., 2000). In experimental 
trials (designed to measure TTS) with marine mammals trained to perform 
tasks when prompted, scientists evaluated whether the marine mammals 
performed these tasks when exposed to mid-frequency tones. Altered 
behavior during experimental trials usually involved refusal of animals 
to return to the site of the sound stimulus, but also included attempts 
to avoid an exposure in progress, aggressive behavior, or refusal to 
further participate in tests.
    Finneran and Schlundt (2004) examined behavioral observations 
recorded by the trainers or test coordinators during the Schlundt et 
al. (2000) and Finneran et al. (2001, 2003, 2005) experiments. These 
included observations from 193 exposure sessions (fatiguing stimulus 
level > 141 dB re 1microPa) conducted by Schlundt et al. (2000) and 21 
exposure sessions conducted by Finneran et al. (2001, 2003, 2005). The 
TTS experiments that supported Finneran and Schlundt (2004) are further 
explained below:
     Schlundt et al. (2000) provided a detailed summary of the 
behavioral responses of trained marine mammals during TTS tests 
conducted at SSC San Diego with 1-sec tones and exposure frequencies of 
0.4 kHz, 3 kHz, 10 kHz, 20 kHz and 75 kHz. Schlundt et al. (2000) 
reported eight individual TTS experiments. The experiments were 
conducted in San Diego Bay. Because of the variable ambient noise in 
the bay, low-level broadband masking noise was used to keep hearing 
thresholds consistent despite fluctuations in the ambient noise. 
Schlundt et al. (2000) reported that ``behavioral alterations,'' or 
deviations from the behaviors the animals being tested had been trained 
to exhibit, occurred as the animals were exposed to increasing 
fatiguing stimulus levels.
     Finneran et al. (2001, 2003, 2005) conducted 2 separate 
TTS experiments using 1-sec tones at 3 kHz. The test methods were 
similar to that of Schlundt et al. (2000) except the tests were 
conducted in a pool with very low ambient noise level (below 50 dB re 1 
microPa\2\/Hz), and no masking noise was used. In the first, fatiguing 
sound levels were increased from 160 to 201 dB SPL. In the second 
experiment, fatiguing sound levels between 180 and 200 dB SPL were 
randomly presented.
    Bottlenose dolphins exposed to 1-sec intense tones exhibited short-
term changes in behavior above received sound levels of 178 to 193 dB 
re 1 microPa (rms), and beluga whales did so at received levels of 180 
to 196 dB and above.
    2. Mysticete Field Study (Nowacek et al., 2004)--The only available 
and applicable data relating mysticete responses to exposure to mid-
frequency sound sources is from Nowacek et al. (2004). Nowacek et al. 
(2004) documented observations of the behavioral response of North 
Atlantic right whales exposed to alert stimuli containing mid-frequency 
components in the Bay of Fundy. Investigators used archival digital 
acoustic recording tags (DTAG) to record the behavior (by measuring 
pitch, roll, heading, and depth) of right whales in the presence of an 
alert signal, and to calibrate received sound levels. The alert signal 
was 18 minutes of exposure consisting of three 2-minute signals played 
sequentially three times over. The three signals had a 60 percent duty 
cycle and consisted of: (1) Alternating 1-sec pure tones at 500 Hz and 
850 Hz; (2) a 2-sec logarithmic down-sweep from 4,500 Hz to 500 Hz; and 
(3) a pair of low (1,500 Hz)-high (2,000 Hz) sine wave tones amplitude 
modulated at 120 Hz and each 1-sec long. The purposes of the alert 
signal were (a) to pique the mammalian auditory system with disharmonic 
signals that cover the whales' estimated hearing range; (b) to maximize 
the signal to noise ratio (obtain the largest difference between 
background noise) and c) to provide localization cues for the whale. 
The maximum source level used was 173 dB SPL.
    Nowacek et al. (2004) reported that five out of six whales exposed 
to the alert signal with maximum received levels ranging from 133 to 
148 dB re 1 microPa significantly altered their regular behavior and 
did so in identical fashion. Each of these five whales: (i) Abandoned 
their current foraging dive prematurely as evidenced by curtailing 
their `bottom time'; (ii) executed a shallow-angled, high power (i.e. 
significantly increased fluke stroke rate) ascent; (iii) remained at or 
near the surface for the duration of the exposure, an abnormally long 
surface interval; and (iv) spent significantly more time at subsurface 
depths (1-10 m) compared with normal surfacing periods when whales 
normally stay within 1 m (1.1 yd) of the surface.

[[Page 20175]]

    3. Odontocete Field Data (Haro Strait--USS SHOUP)--In May 2003, 
killer whales were observed exhibiting behavioral responses generally 
described as avoidance behavior while the U.S. Ship (USS) SHOUP was 
engaged in MFAS in the Haro Strait in the vicinity of Puget Sound, 
Washington. Those observations have been documented in three reports 
developed by Navy and NMFS (NMFS, 2005a; Fromm, 2004a, 2004b; DON, 
2003). Although these observations were made in an uncontrolled 
environment, the sound field that may have been associated with the 
sonar operations was estimated using standard acoustic propagation 
models that were verified (for some but not all signals) based on 
calibrated in situ measurements from an independent researcher who 
recorded the sounds during the event. Behavioral observations were 
reported for the group of whales during the event by an experienced 
marine mammal biologist who happened to be on the water studying them 
at the time. The observations associated with the USS SHOUP provide the 
only data set available of the behavioral responses of wild, non-
captive animal upon actual exposure to AN/SQS-53 sonar.
    U.S. Department of Commerce (NMFS, 2005a); U.S. Department of the 
Navy (2004b); Fromm (2004a, 2004b) documented reconstruction of sound 
fields produced by USS SHOUP associated with the behavioral response of 
killer whales observed in Haro Strait. Observations from this 
reconstruction included an approximate closest approach time which was 
correlated to a reconstructed estimate of received level (which ranged 
from 150 to 180 dB) at an approximate whale location with a mean value 
of 169.3 dB SPL.
    Calculation of K Parameter--NMFS and the Navy used the mean of the 
following values to define the midpoint of the function: (1) The mean 
of the lowest received levels (185.3 dB) at which individuals responded 
with altered behavior to 3 kHz tones in the SSC data set; (2) the 
estimated mean received level value of 169.3 dB produced by the 
reconstruction of the USS SHOUP incident in which killer whales exposed 
to MFA sonar (range modeled possible received levels: 150 to 180 dB); 
and (3) the mean of the 5 maximum received levels at which Nowacek et 
al. (2004) observed significantly altered responses of right whales to 
the alert stimuli than to the control (no input signal) is 139.2 dB 
SPL. The arithmetic mean of these three mean values is 165 dB SPL. The 
value of K is the difference between the value of B (120 dB SPL) and 
the 50 percent value of 165 dB SPL; therefore, K=45.
    A Parameter (Steepness)--NMFS determined that a steepness parameter 
(A)=10 is appropriate for odontocetes (except harbor porpoises) and 
pinnipeds and A=8 is appropriate for mysticetes.
    The use of a steepness parameter of A=10 for odontocetes (except 
harbor porpoises) for the HFAS/MFAS risk function was based on the use 
of the same value for the SURTASS LFA risk continuum, which was 
supported by a sensitivity analysis of the parameter presented in 
Appendix D of the SURTASS/LFA FEIS (DON, 2001c). As concluded in the 
SURTASS FEIS/EIS, the value of A=10 produces a curve that has a more 
gradual transition than the curves developed by the analyses of 
migratory gray whale studies (Malme et al., 1984; Buck and Tyack, 2000; 
and SURTASS LFA Sonar EIS, Subchapters 1.43, 4.2.4.3 and Appendix D, 
and NMFS, 2008).
    NMFS determined that a lower steepness parameter (A=8), resulting 
in a shallower curve, was appropriate for use with mysticetes and HFAS/
MFAS. The Nowacek et al. (2004) dataset contains the only data 
illustrating mysticete behavioral responses to a mid-frequency sound 
source. A shallower curve (achieved by using A=8) better reflects the 
risk of behavioral response at the relatively low received levels at 
which behavioral responses of right whales were reported in the Nowacek 
et al. (2004) data. Compared to the odontocete curve, this adjustment 
results in an increase in the proportion of the exposed population of 
mysticetes being classified as behaviorally harassed at lower RLs, such 
as those reported in and is supported by the only dataset currently 
available.
    Basic Application of the Risk Function--The risk function is used 
to estimate the percentage of an exposed population that is likely to 
exhibit behaviors that would qualify as harassment (as that term is 
defined by the MMPA applicable to military readiness activities, such 
as the Navy's testing and research activities with HFA/MFA sonar) at a 
given received level of sound. For example, at 165 dB SPL (dB re: 1 
microPa rms), the risk (or probability) of harassment is defined 
according to this function as 50 percent, and Navy/NMFS applies that by 
estimating that 50 percent of the individuals exposed at that received 
level are likely to respond by exhibiting behavior that NMFS would 
classify as behavioral harassment. The risk function is not applied to 
individual animals, only to exposed populations.
    The data primarily used to produce the risk function (the K 
parameter) were compiled from four species that had been exposed to 
sound sources in a variety of different circumstances. As a result, the 
risk function represents a general relationship between acoustic 
exposures and behavioral responses that is then applied to specific 
circumstances. That is, the risk function represents a relationship 
that is deemed to be generally true, based on the limited, best-
available science, but may not be true in specific circumstances. In 
particular, the risk function, as currently derived, treats the 
received level as the only variable that is relevant to a marine 
mammal's behavioral response. However, we know that many other 
variables--the marine mammal's gender, age, and prior experience; the 
activity it is engaged in during an exposure event, its distance from a 
sound source, the number of sound sources, and whether the sound 
sources are approaching or moving away from the animal--can be 
critically important in determining whether and how a marine mammal 
will respond to a sound source (Southall et al., 2007). The data that 
are currently available do not allow for incorporation of these other 
variables in the current risk functions; however, the risk function 
represents the best use of the data that are available (Figure 1).

[[Page 20176]]

[GRAPHIC] [TIFF OMITTED] TP30AP09.002

    As more specific and applicable data become available for HFAS/MFAS 
sources, NMFS can use these data to modify the outputs generated by the 
risk function to make them more realistic. Ultimately, data may exist 
to justify the use of additional, alternate, or multivariate functions. 
For example, as mentioned previously, the distance from the sound 
source and whether it is perceived as approaching or moving away can 
affect the way an animal responds to a sound (Wartzok et al., 2003).

Explosive Detonation Criteria

Acoustic Effects: Ordnance

    Live ordnance testing may occur from the surf zone out to the outer 
perimeter of the NSWC PCD Study Area. The size and weight of the 
explosives used would vary from 0.91 to 272 kg (2 to 600 lb) 
trinitrotoluene (TNT) equivalent net explosive weight (NEW). No 
detonations over 34 kg (75 lb) NEW will be conducted within the 
territorial waters of the NSWC PCD Study Area. Operations involving 
live explosives include mine detonations and surf zone line charge 
detonations.
    Underwater detonations may project pressure and sound intensities 
sufficient to cause physical trauma or acoustic or behavioral effects 
to protected marine mammals. Determining the potential exposures 
associated with ordnance operations is very similar to determining 
potential exposures associated with sonar operations described above.
Metrics: Underwater Explosive Sound
    Four standard acoustic metrics for measuring underwater pressure 
waves were used in this analysis:
     Total Energy Flux Density Level (EFD)
     \1/3\-Octave EFD
     Positive Impulse
     Peak Pressure
    Total EFD--Total EFD is the metric used for analyzing the level of 
sound that would cause a permanent decrease in hearing sensitivity. 
Decibels are used to express this metric.
    \1/3\-Octave EFD--One-third octave EFD is the metric used in 
discussions of temporary (i.e., recoverable) hearing loss and for 
behavioral response thresholds of protected species to sound. One-third 
octave EFD is the energy flux density in the \1/3\-octave frequency 
band at which the animal potentially exposed hears best. Decibels are 
also used to express this metric. This metric is used for analyzing 
underwater detonations.
    Positive Impulse--Positive impulse is the metric used for analyzing 
lethal sound levels, as well as sound that marks the onset of slight 
lung injury in cetaceans. Positive impulse as it is used here is based 
on an equation modified by Goertner (1982); thus it is more completely 
stated as the Goertner-modified positive impulse. The units to express 
this metric are pounds per square inch millisecond (psi-ms).
    Peak Pressure--This is the maximum positive pressure for an arrival 
of a sound pressure wave that a marine mammal would receive at some 
distance away from a detonation. Units used here are pounds per square 
inch (psi) and dB levels.
Criteria and Thresholds for Explosive Sound
    Criteria and thresholds for estimating the effects on protected 
species including marine mammals and sea turtles from a single 
explosive event were established and publicly vetted through the NEPA 
process during the Seawolf Submarine Shock Test FEIS (``Seawolf'') and 
the USS Winston S. Churchill (DDG-81) Ship Shock FEIS (``Churchill'') 
(DON, 2001). These

[[Page 20177]]

criteria and thresholds were adopted by NMFS in its final rule on 
unintentional taking of marine animals incidental to the shock testing. 
The risk assessment approach for all gunfire-related sound in water was 
derived from the Seawolf/Churchill approach.

Criteria and Thresholds for Physiological Effects to Explosive Sound

    The criterion for mortality for marine mammals used in the 
Churchill FEIS is ``onset of severe lung injury.'' This criterion is 
conservative in that it corresponds to a 1 percent chance of mortal 
injury, and yet any animal experiencing onset severe lung injury is 
counted as a lethal exposure. The threshold is stated in terms of the 
Goertner (1982) modified positive impulse with value ``indexed to 31 
psi-msec.'' Since the Goertner approach depends on propagation, source/
animal depths, and animal mass in a complex way, the actual impulse 
value corresponding to the 31 psi-msec index is a complicated 
calculation. Again, to be conservative, Churchill used the mass of a 
calf dolphin (at 12.2 kg or 26.9 lb), so that the threshold index is 
30.5 psi-msec.
    Dual criteria are used for injury: 50 percent eardrum rupture 
(i.e., tympanic membrane [TM] rupture) and onset of slight lung injury. 
These criteria are considered indicative of the onset of injury. The 
threshold for TM rupture corresponds to a 50 percent rate of rupture 
(i.e., 50 percent of animals exposed to the level are expected to 
suffer TM); this is stated in terms of an EL value of 1.17 inches pound 
per square inch (in-lb/in\2\) (about 205 dB re 1 microPa\2\-s). This 
recognizes that TM rupture is not necessarily a serious or life-
threatening injury but is a useful index of possible injury that is 
well-correlated with measures of permanent hearing impairment (e.g., 
Ketten (1998) indicates a 30 percent incidence of PTS at the same 
threshold).
    The threshold for onset of slight lung injury is calculated for a 
calf dolphin (12.2 kg, or 27 lb); it is given in terms of the 
``Goertner modified positive impulse,'' indexed to 13 psi-ms. This is a 
departure from the Churchill and Seawolf approaches in the use of 
animal mass in the Goertner threshold for slight lung injury. In this 
assessment, cetaceans are assessed as calves, defined as those with 
mass less than 174 kg (384 lb). The associated threshold is indexed to 
13 psi-msec, which corresponds to a calf dolphin at 12.2 kg (27 lb) 
(DON, 2001).
    The first criterion for non-injurious harassment is TTS, which is 
defined as a temporary, recoverable loss of hearing sensitivity (NMFS, 
2001; DON, 2001). The criterion for TTS is 182 dB re 1 microPa\2\-s, 
which is the greatest energy flux density level in any \1/3\-octave 
band at frequencies above 100 Hz for marine mammals.
    The second criterion for estimating TTS threshold applies to all 
cetacean species and is stated in terms of peak pressure at 23 psi. The 
threshold is derived from the Churchill threshold which was 
subsequently adopted by NMFS in its Final Rule on the unintentional 
taking of marine animals incidental to the shock testing (NMFS, 2001). 
The original criteria in Churchill incorporated 12 psi. The current 
criteria and threshold for peak pressure over all exposures was updated 
from 12 psi to 23 psi for explosives less than 907 kg (2,000 lb) based 
on an IHA issued to the Air Force for a similar action (NOAA, 2006a). 
Peak pressure and energy scale at different rates with charge weight, 
so that ranges based on the peak-pressure threshold are much greater 
than those for the energy metric when charge weights are small, even 
when source and animal are away from the surface. In order to more 
accurately estimate TTS for smaller shots while preserving the safety 
feature provided by the peak pressure threshold, the peak pressure 
threshold is appropriately scaled for small shot detonations. This 
scaling is based on the similitude formulas (e.g., Urick, 1983) used in 
virtually all compliance documents for short ranges. Further, the peak-
pressure threshold for marine mammal TTS for explosives offers a safety 
margin for source or animal near the ocean surface.

Criteria and Thresholds for Behavioral Effects to Explosive Sound

    For a single explosion, to be consistent with Churchill, TTS is the 
criterion for Level B harassment. In other words, because behavioral 
disturbance for a single explosion is likely to be limited to a short-
lived startle reaction, use of the TTS criterion is considered 
sufficient protection. Behavioral modification (sub-TTS) is only 
applied to successive detonations. Table 5 summarizes the criteria and 
thresholds used in calculating the potential impacts to marine mammal 
from explosive sound.

                      Table 5--Effects, Criteria, and Thresholds for Explosive Detonations
----------------------------------------------------------------------------------------------------------------
             Effect                     Criteria             Metric             Threshold            Effect
----------------------------------------------------------------------------------------------------------------
Mortality.......................  Onset of Severe      Goertner modified   indexed to 30.5     Mortality.
                                   Lung Injury (1%      positive impulse.   psi-msec (assumes
                                   probability of                           100 percent small
                                   mortality).                              animal at 26.9
                                                                            lbs).
Injurious Physiological.........  Onset Slight Lung    Goertner modified   indexed to 13 psi-  Level A.
                                   Injury.              positive impulse.   msec (assumes 100
                                                                            percent small
                                                                            animal at 26.9
                                                                            lbs).
Injurious Physiological.........  50% Tympanic         Energy flux         1.17 in-lb/in\2\    Level A.
                                   Membrane Rupture.    density.            (about 205 dB re
                                                                            1 microPa\2\-sec).
Non-injurious Physiological.....  TTS................  Greatest energy     182 dB re 1         Level B.
                                                        flux density        microPa\2\-sec.
                                                        level in any \1/
                                                        3\-octave band
                                                        (>100 Hz for
                                                        toothed whales
                                                        and >10 Hz for
                                                        baleen whales)--
                                                        for total energy
                                                        over all
                                                        exposures.
Non-injurious Physiological.....  TTS................  Peak pressure over  23 psi............  Level B.
                                                        all exposures.
Non-injurious Behavioral........  Multiple Explosions  Greatest energy     177 dB re 1         Level B.
                                   Without TTS.         flux density        microPa\2\-sec.
                                                        level in any \1/
                                                        3\-octave (>100
                                                        Hz for toothed
                                                        whales and >10 Hz
                                                        for baleen
                                                        whales)--for
                                                        total energy over
                                                        all exposures
                                                        (multiple
                                                        explosions only).
----------------------------------------------------------------------------------------------------------------


[[Page 20178]]

Acoustic Effects: Projectile Firing

    Projectile firing includes the use of inert rounds of ammunition as 
well as high-explosive (HE) 5-in gun-rounds. The primary concern with 
respect to projectile firing and marine mammals encompasses the 
potential sound effects associated with their detonations. The same 
thresholds were used to analyze projectile firing as the previous 
section on ordnance operations. Modeling took into account the firing 
of single shots separated in time.

Estimated Exposures of Marine Mammals

Marine Mammal Exposures Due to HFAS/MFAS Operations

    Acoustical modeling provides an estimate of the actual exposures. 
Detailed information and formulas to model the effects of sonar from 
RDT&E activities in the NSWC PCD Study Area is provided in Appendix A, 
Supplemental Information for Underwater Noise Analysis of the LOA 
application.
    The quantitative analysis was based on conducting sonar operations 
in 16 different geographical regions, or provinces. Using combined 
marine mammal density and depth estimates, acoustical modeling was 
conducted to calculate the actual exposures. Refer to Appendix B, 
Geographic Description of Environmental Provinces of the LOA 
application, for additional information on provinces. Refer to Appendix 
C, Definitions and Metrics for Acoustic Quantities of the LOA 
application, for additional information regarding the acoustical 
analysis.
    The approach for estimating potential acoustic effects from NSWC 
PCD RDT&E activities on cetacean species uses the methodology that the 
DON developed in cooperation with NOAA for the Navy's USWTR Draft OEIS/
EIS (2005), Undersea Warfare Exercise (USWEX) Environmental Assessment 
(EA)/Overseas Environmental Assessment (OEA) (U.S. DON, 45, 2007a), 
RIMPAC EA/OEA (DON, Commander Third Fleet, 2006), Composite Training 
Unit Exercises (COMPTUEX)/Joint Task Force Exercises (JTFEX) EA/OEA 
(DON, 2007b), and HRC Draft EIS (DON, 2007c). The exposure analysis for 
behavioral response to sound in the water uses energy flux density for 
Level A harassment and the methods for risk function for Level B 
harassment (behavioral). The methodology is provided here to determine 
the number and species of marine mammals for which incidental take 
authorization is requested.
    To estimate acoustic effects from the NSWC PCD RDT&E activities, 
acoustic sources to be used were examined with regard to their 
operational characteristics as described in the previous section. In 
addition, systems with an operating frequency greater than 200 kHz were 
not analyzed in the detailed modeling as these signals attenuate 
rapidly, resulting in very short propagation distances. Acoustic 
countermeasures were previously examined and found not to be 
problematic. These acoustic sources, therefore, did not require further 
examination in this analysis. Based on the information above, the Navy 
modeled the following systems:
     Kingfisher
     Sub-bottom profilers
     SAS-LFs and SAS-HFs
     Modems
     AN/SQQ-32
     BPAUVs
     ACL
     TVSS
     F84Y
     AN/AQS-20
     Navigation systems
    Sonar parameters including source levels, ping length, the interval 
between pings, output frequencies, directivity (or angle), and other 
characteristics were based on records from previous test scenarios and 
projected future testing. Additional information on sonar systems and 
their associated parameters is in Appendix A, Supplemental Information 
for Underwater Noise Analysis of the LOA application.
    Every active sonar operation has the potential of exposing marine 
animals in the neighboring waters. The number of animals exposed to the 
sonar in any such action is dictated by the propagation field and the 
manner in which the sonar is operated (i.e., source level, depth, 
frequency, pulse length, directivity, platform speed, repetition rate). 
The modeling for NSWC PCD RDT&E activities involving sonar occurred in 
five broad steps, listed below and was conducted based on the typical 
RDT&E activities planned for the NSWC PCD Study Area.
    Step 1. Environmental Provinces. The NSWC PCD Study Area is divided 
into 16 environmental provinces, and each has a unique combination of 
environmental conditions. These represent various combinations of eight 
bathymetry provinces, one Sound Velocity Profile (SVP) province, and 
three Low-Frequency Bottom Loss geo-acoustic provinces and two High-
Frequency Bottom Loss classes. These are addressed by defining eight 
fundamental environments in two seasons that span the variety of 
depths, bottom types, sound speed profiles, and sediment thicknesses 
found in the NSWC PCD Study Area. The two seasons encompass winter and 
summer, which are the two extremes and for the GOM, the acoustic 
propagation characteristics do not vary significantly between the two. 
Each marine modeling area can be quantitatively described as a unique 
combination of these environments.
    Step 2. Transmission Loss. Since sound propagates differently in 
these environments, separate transmission loss calculations must be 
made for each, in both seasons. The transmission loss is predicted 
using Comprehensive Acoustic Simulation System/Gaussian Ray Bundle 
(CASS-GRAB) sound modeling software.
    Step 3. Exposure Volumes. The transmission loss, combined with the 
source characteristics, gives the energy field of a single ping. The 
energy of over 10 hours of pinging is summed, carefully accounting for 
overlap of several pings, so an accurate average exposure of an hour of 
pinging is calculated for each depth increment. At more than ten hours, 
the source is too far away and the energy is negligible. In addition, 
the acoustic modeling takes into account the use of a single system. 
Only one source will operate at any one time during NSWC PCD RDT&E 
activities.
    Repeating this calculation for each environment in each season 
gives the hourly ensonified volume, by depth, for each environment and 
season. This step begins the method for risk function modeling.
    Step 4. Marine Mammal Densities. The marine mammal densities were 
given in two dimensions, but using reliable peer-reviewed literature 
sources (published literature and agency reports) described in the 
following subsection, the depth regimes of these marine mammals are 
used to project the two dimensional densities (expressed as the number 
of animals per area where all individuals are assumed to be at the 
water's surface) into three dimensions (a volumetric approach whereby 
two-dimensional animal density incorporates depth into the calculation 
estimates).
    Step 5. Exposure Calculations. Each marine mammal's three-
dimensional (3-D) density is multiplied by the calculated impact volume 
to that marine mammal depth regime. This value is the number of 
exposures per hour for that particular marine mammal. In this way, each 
marine mammal's exposure count per hour is based on its density, depth 
habitat, and the ensonified volume by depth.

[[Page 20179]]

    The planned sonar hours for each system were inserted and a 
cumulative number of exposures were determined for each alternative.
    As previously mentioned, NSWC PCD RDT&E activities involve mid-
frequency sonar operation for only 6 percent of operational hours. 
Furthermore, testing generally involves short-term use and single 
systems at a time. Appendix A, Supplemental Information for Underwater 
Noise Analysis of the LOA application, includes specific formulas and 
more detailed information.

Marine Mammal Sonar Exposures in Territorial Waters

    Sonar operations in territorial waters may expose bottlenose 
dolphins and Atlantic spotted dolphins to sound likely to result in 
Level B (behavioral) harassment. In addition, three bottlenose dolphins 
and two Atlantic spotted dolphins may be exposed to levels of sound 
likely to result in TTS (Table 6).

  Table 6--Estimates of Marine Mammal Exposures From Sonar Missions in
                       Territorial Waters per Year
------------------------------------------------------------------------
                                                Level B       Level B
       Marine mammal species         Level A     (TTS)     (behavioral)
------------------------------------------------------------------------
Bottlenose dolphin................          0          3             521
Atlantic spotted dolphin..........          0          2             408
------------------------------------------------------------------------

Marine Mammal Sonar Exposures in Non-Territorial Waters

    Sonar operations in non-territorial waters may expose up to ten 
species to sound likely to result in Level B (behavioral) harassment 
(Table 7). They include the sperm whale, Risso's dolphin, rough-toothed 
dolphin, bottlenose dolphin, Atlantic bottlenose dolphin, Atlantic 
spotted dolphin, pantropical spotted dolphin, striped dolphin, spinner 
dolphin, Clymene dolphin, melon-headed whale, and short-finned pilot 
whale. In addition, sonar operations in non-territorial waters may 
expose up to one bottlenose dolphin and one Atlantic spotted dolphin to 
levels of sound likely to result in TTS. Marine mammals are likely to 
incur only Level B harassment from sonar exercises in non-territorial 
waters.

Table 7--Estimates of Marine Mammal Exposures From Sonar Missions in Non-
                       Territorial Waters per Year
------------------------------------------------------------------------
                                                Level B       Level B
       Marine mammal species         Level A     (TTS)     (behavioral)
------------------------------------------------------------------------
Bryde's whale.....................          0          0               0
Sperm whale.......................          0          0               1
Dwarf/Pygmy sperm whale...........          0          0               0
All beaked whales.................          0          0               0
Killer whale......................          0          0               0
False killer whale................          0          0               0
Pygmy killer whale................          0          0               0
Melon-headed whale................          0          0               1
Short-finned pilot whale..........          0          0               1
Risso's dolphin...................          0          0               1
Rough-toothed dolphin.............          0          0               0
Bottlenose dolphin................          0          1              46
Atlantic spotted dolphin..........          0          1              39
Pantropical spotted dolphin.......          0          0              16
Striped dolphin...................          0          0               3
Spinner dolphin...................          0          0              13
Clymene dolphin...................          0          0               5
Fraser's dolphin..................          0          0               0
------------------------------------------------------------------------

Marine Mammal Exposures Due to Ordnance

Calculation Methods
    An overview of the methods to determine the number of exposures of 
MMPA-protected species to sound likely to result in mortality, Level A 
harassment (injury), or Level B harassment is provided in the following 
paragraphs. Appendix A, ``Supplemental Information for Underwater Noise 
Analysis'' of the LOA application, includes specific formulas and more 
detailed information.
    Acoustic threshold areas are derived from mathematical calculations 
and models that predict the distances or range to which threshold sound 
levels will travel. Sound is assumed to spread more or less 
spherically. Therefore, the range of influence is the radius of an 
ensonified area (the area exposed to sound). The equations for the 
models consider the amount of net explosive and the properties of 
detonations under water as well as environmental factors such as depth 
of the explosion, overall water depth, water temperature, and bottom 
type. Various combinations of these environmental factors result in a 
number of environmental provinces.
    The result of the calculations and/or modeling is a volume. There 
are separate volumes for mortality, harassment resulting in injury 
(hearing-related and slight lung), and behavioral harassment (from TTS 
and sub-TTS). For mine detonations, the sound effects were modeled 
using the different net explosive weights at 16 environmental provinces 
during the winter and summer seasons. There are three ranges of NEW: 1-
10 lb (0.45-4.5 kg), 11-75 lb (5-34 kg), and 76-600 lbs (34.5-272 kg). 
The three ranges of NEW for mine detonations mirror the ranges 
identified in the analysis of alternatives. Due to differences in 
delivery and orientation, line charges are not included within these 
three ranges of NEW, and their

[[Page 20180]]

potential effects were analyzed and presented separately. A discussion 
of the equations used and environmental provinces and equations used 
are provided in Appendix A, ``Supplemental Information for Underwater 
Noise Analysis,'' and Appendix B, ``Geographic Description of Acoustic 
Environmental Provinces'' of the LOA application.
    Based on the model calculation, the various zones of influence from 
these three ranges of NEW are listed below in Table 8.

     Table 8--Zones of Influence (in Meters) From Different Ranges of NEW Under Explosive Acoustic Criteria
----------------------------------------------------------------------------------------------------------------
                                                                                   Indexed to 13    Indexed to
                                                                   1.17 in-lb/in     psi-msec      30.5 psi-msec
                                    182 dB re 1                   \2\ (about 205   (assumes 100    (assumes 100
           Size of NEW             microPa \2\-       23 psi          dB re 1      percent small   percent small
                                        sec                        microPa \2\-   animal at 26.9  animal at 26.9
                                                                       sec)            lbs)            lbs)
----------------------------------------------------------------------------------------------------------------
10 lb...........................             345             379             151              70              15
75 lb...........................             997             535             357             190              66
600 lb..........................           2,863           1,186             927             502             203
----------------------------------------------------------------------------------------------------------------

    Analysis for mine-clearing line charges followed methods similar to 
detonations. The major differences in the line charge analysis included 
(1) focus on propagation through the sediment layer(s) rather than 
treating the bottom as a boundary with a particular reflection loss and 
(2) modeling according to its unique physical characteristics. The 
specific information on calculations for mine-clearing line charges is 
presented in Appendix A, ``Supplemental Information for Underwater 
Noise Analysis'' of the LOA application.
    Acoustical modeling is a conservative measure of the actual 
exposures and, therefore, the numbers presented in the following 
paragraphs are not necessarily indicative of actual exposures under the 
MMPA. In an effort to reduce the potential exposures associated with 
live detonations, the mitigation and protective measures will be 
implemented.

Marine Mammal Ordnance Exposures in Territorial Waters

    Detonations in territorial waters may expose up to three bottlenose 
dolphins and two Atlantic spotted dolphins to sound likely to result in 
harassment (Table 9). Marine mammals are likely to incur only Level B 
harassment from ordnance exercises conducted in territorial waters.

 Table 9--Estimates of Marine Mammal Exposures From Detonations (0-34 kg
               or 0-75 lb) in Territorial Waters per Year
------------------------------------------------------------------------
                                    Mortality     Level A
                                     (severe      (slight      Level B
      Marine mammal species            lung         lung        (non-
                                     injury)      injury)      injury)
------------------------------------------------------------------------
Bottlenose dolphin...............            0            0            3
Atlantic spotted dolphin.........            0            0            2
------------------------------------------------------------------------

    Line charge events will only be conducted in the surf zone along a 
portion of Santa Rosa Island in water depth between 1-3 meters (which 
is not a normal habitat for marine mammals). The charge is considered 
one explosive source that has multiple increments that detonate at one 
time. Line charge events produce a series of small detonations (5 lb. 
increments) that occur sequentially, rather than a simultaneous large 
explosion. The instantaneous SPL produced by these sequential 
detonations is significantly less than a single, large explosion and is 
unlikely to produce harmful levels of energy. The Navy's model revealed 
that given the small, sequential explosions, the ZOIs would be small as 
compared to a single large explosion. Combined with shallow water in 
which the exercises are proposed to be conducted and the fewer marine 
mammals expected in the surf zone, NMFS and the Navy do not expect 
marine mammals to experience harassment from sound generated by line 
charge exercises in territorial waters (Table 10).

Table 10--Estimates of Marine Mammal Exposures From Line Charges (794 kg
               or 1,750 lb) in Territorial Waters per Year
------------------------------------------------------------------------
                                    Mortality     Level A
                                     (severe      (slight      Level B
      Marine mammal species            lung         lung        (non-
                                     injury)      injury)      injury)
------------------------------------------------------------------------
Bottlenose dolphin...............            0            0            0
Atlantic spotted dolphin.........            0            0            0
------------------------------------------------------------------------


[[Page 20181]]

Marine Mammal Ordnance Exposures in Non-Territorial Waters
    Detonations in non-territorial waters may expose up to eight marine 
mammal species to sound likely to result in Level B harassment (Table 
11). They include the sperm whale, melon-headed whale, Risso's dolphin, 
rough-toothed dolphin, bottlenose dolphin, Atlantic spotted dolphin, 
pantropical spotted dolphin, striped dolphin, and spinner dolphin. In 
addition, two bottlenose dolphin, two Atlantic spotted dolphin, one 
pantropical spotted dolphin, and one spinner dolphin may be exposed to 
levels of sound likely to result in Level A harassment (slight lung 
injury). Although Navy's modeling showed that one bottlenose dolphin 
and one Atlantic spotted dolphin may be exposed to levels of sound 
likely to result in mortality (severe lung injury), NMFS considers that 
such events are unlikely. Based on the ZOIs calculated for different 
categories of NEW explosives, the animals have to be within a range of 
203 m from the explosion in order to experience severe lung injury or 
mortality. NMFS expects that the mitigation and monitoring measures 
associated with ordnance exercises will provide sufficient protection 
to marine mammals, and will prevent mortality because operations will 
not be conducted (or will be suspended, as appropriate) if animals are 
detected within or approaching the ZOI.

 Table 11--Estimates of Marine Mammal Exposures From Detonations (34-272
           kg [76-600 lb]) in Non-Territorial Waters per Year*
------------------------------------------------------------------------
                                    Mortality     Level A
                                     (severe      (slight      Level B
      Marine mammal species            lung         lung        (non-
                                     injury)      injury)      injury)
------------------------------------------------------------------------
Bryde's whale....................            0            0            0
Sperm whale......................            0            0            1
Dwarf/Pygmy sperm whale..........            0            0            0
All beaked whales................            0            0            0
Killer whale.....................            0            0            0
False killer whale...............            0            0            0
Pygmy killer whale...............            0            0            0
Melon-headed whale...............            0            0            1
Short-finned pilot whale.........            0            0            0
Risso's dolphin..................            0            0            1
Rough-toothed dolphin............            0            0            0
Bottlenose dolphin...............            0            2           38
Atlantic spotted dolphin.........            0            2           18
Pantropical spotted dolphin......            0            1            6
Striped dolphin..................            0            0            2
Spinner dolphin..................            0            1           10
Clymene dolphin..................            0            0            0
------------------------------------------------------------------------
* The Navy's estimates were revised by NMFS after further analysis and
  consideration of the proposed mitigation and monitoring measures.

Marine Mammal Exposures Due to Projectile Firing

    Live projectile firing operations will not occur in territorial 
waters.
    Five-inch round testing is to have 60, 5-inch rounds tested 
annually. Projectile firing in non-territorial waters may expose up to 
three species of marine mammals to sound likely to result in Level B 
harassment (Table 12). They include the bottlenose dolphin and Atlantic 
spotted dolphin, pantropical and striped dolphin. Marine mammals are 
likely to incur only Level B harassment from the projectile firing 
exercises occurring in non-territorial waters.
    In addition, tests involving projectile firing are conducted at 
close range. The probability is low that a marine mammal will enter the 
firing area directly adjacent to the target undetected simultaneous to 
projectile firing. The noise associated with the firing and the support 
aircraft and/or surface vessels would likely cause animals to avoid the 
area. Furthermore, the mitigation and clearance procedures described 
below will be implemented, thereby reducing the likelihood that a 
marine mammal will enter the firing area at the same time a projectile 
firing exercise is initiated. If present, large groups of cetaceans 
such as schools of dolphin species and large species of whales such as 
sperm whales and Bryde's whales will be sighted at the surface during 
standard clearance procedures and operations would be suspended until 
such time as these animals leave the target area.

    Table 12--Estimates of Marine Mammal Exposures From 5-Inch Round
             Detonations in Non-Territorial Waters per Year
------------------------------------------------------------------------
                                    Mortality     Level A
                                     (severe      (slight      Level B
      Marine mammal species            lung         lung        (non-
                                     injury)      injury)      injury)
------------------------------------------------------------------------
Bryde's whale....................            0            0            0
Sperm whale......................            0            0            0
Dwarf/Pygmy sperm whale..........            0            0            0
All beaked whales................            0            0            0
Killer whale.....................            0            0            0
False killer whale...............            0            0            0
Pygmy killer whale...............            0            0            0
Melon-headed whale...............            0            0            0
Short-finned pilot whale.........            0            0            0

[[Page 20182]]

 
Risso's dolphin..................            0            0            0
Rough-toothed dolphin............            0            0            0
Bottlenose dolphin...............            0            0            2
Atlantic spotted dolphin.........            0            0            1
Pantropical spotted dolphin......            0            0            1
Striped dolphin..................            0            0            0
Spinner dolphin..................            0            0            0
Clymene dolphin..................            0            0            0
------------------------------------------------------------------------

    Table 13 provides a summary of estimated marine mammals under NMFS 
jurisdiction that could be affected by the proposed NSWC PCD RDT&E 
activities.

 Table 13--Estimates of Total Marine Mammal Exposures From the NSWC PCD
                       Mission Activities per Year
------------------------------------------------------------------------
                                    Mortality     Level A
                                     (severe      (slight      Level B
      Marine mammal species            lung         lung        (non-
                                     injury)      injury)      injury)
------------------------------------------------------------------------
Bryde's whale....................  ...........  ...........  ...........
Sperm whale......................  ...........  ...........            2
Dwarf/Pygmy sperm whale..........  ...........  ...........  ...........
All beaked whales................  ...........  ...........  ...........
Killer whale.....................  ...........  ...........  ...........
False killer whale...............  ...........  ...........  ...........
Pygmy killer whale...............  ...........  ...........  ...........
Melon-headed whale...............  ...........  ...........            2
Short-finned pilot whale.........  ...........  ...........            1
Risso's dolphin..................  ...........  ...........            2
Rough-toothed dolphin............  ...........  ...........  ...........
Bottlenose dolphin...............            0            2          614
Atlantic spotted dolphin.........            0            2          471
Pantropical spotted dolphin......  ...........            1           23
Striped dolphin..................  ...........  ...........            5
Spinner dolphin..................  ...........            1           23
Clymene dolphin..................  ...........  ...........            5
------------------------------------------------------------------------

Effects on Marine Mammal Habitat

    There are no areas within the NSWC PCD that are specifically 
considered as important physical habitat for marine mammals.
    The prey of marine mammals are considered part of their habitat. 
The Navy's DEIS for the NSWC PCD contains a detailed discussion of the 
potential effects to fish from HFAS/MFAS and explosive detonations. 
Below is a summary of conclusions regarding those effects.

Effects on Fish From HFAS/MFAS

    The extent of data, and particularly scientifically peer-reviewed 
data, on the effects of high intensity sounds on fish is limited. In 
considering the available literature, the vast majority of fish species 
studied to date are hearing generalists and cannot hear sounds above 
500 to 1,500 Hz (depending upon the species), and, therefore, 
behavioral effects on these species from higher frequency sounds are 
not likely. Moreover, even those fish species that may hear above 1.5 
kHz, such as a few sciaenids and the clupeids (and relatives), have 
relatively poor hearing above 1.5 kHz as compared to their hearing 
sensitivity at lower frequencies. Therefore, even among the species 
that have hearing ranges that overlap with some mid- and high frequency 
sounds, it is likely that the fish will only actually hear the sounds 
if the fish and source are very close to one another. Finally, since 
the vast majority of sounds that are of biological relevance to fish 
are below 1 kHz (e.g., Zelick et al., 1999; Ladich and Popper, 2004), 
even if a fish detects a mid- or high frequency sound, these sounds 
will not mask detection of lower frequency biologically relevant 
sounds. Based on the above information, there will likely be few, if 
any, behavioral impacts on fish.
    Alternatively, it is possible that very intense mid- and high 
frequency signals, and particularly explosives, could have a physical 
impact on fish, resulting in damage to the swim bladder and other organ 
systems. However, even these kinds of effects have only been shown in a 
few cases in response to explosives, and only when the fish has been 
very close to the source. Such effects have never been indicated in 
response to any Navy sonar. Moreover, at greater distances (the 
distance clearly would depend on the intensity of the signal from the 
source) there appears to be little or no impact on fish, and 
particularly no impact on fish that do not have a swim bladder or other 
air bubble that would be affected by rapid pressure changes.

Effects on Fish From Explosive Detonations

    There are currently no well-established thresholds for estimating

[[Page 20183]]

effects to fish from explosives other than mortality models. Fish that 
are located in the water column, in proximity to the source of 
detonation could be injured, killed, or disturbed by the impulsive 
sound and possibly temporarily leave the area. Continental Shelf Inc. 
(2004) summarized a few studies conducted to determine effects 
associated with removal of offshore structures (e.g., oil rigs) in the 
Gulf of Mexico. Their findings revealed that at very close range, 
underwater explosions are lethal to most fish species regardless of 
size, shape, or internal anatomy. For most situations, cause of death 
in fishes has been massive organ and tissue damage and internal 
bleeding. At longer range, species with gas-filled swimbladders (e.g., 
snapper, cod, and striped bass) are more susceptible than those without 
swimbladders (e.g., flounders, eels). Studies also suggest that larger 
fishes are generally less susceptible to death or injury than small 
fishes. Moreover, elongated forms that are round in cross section are 
less at risk than deep-bodied forms; and orientation of fish relative 
to the shock wave may affect the extent of injury. Open water pelagic 
fish (e.g., mackerel) also seem to be less affected than reef fishes. 
The results of most studies are dependent upon specific biological, 
environmental, explosive, and data recording factors.
    The huge variations in the fish population, including numbers, 
species, sizes, and orientation and range from the detonation point, 
make it very difficult to accurately predict mortalities at any 
specific site of detonation. Fish have the ability to quickly and 
easily leave an area temporarily when vessels and/or helicopters 
approach; it is reasonable to assume that fish will leave an area prior 
to ordnance detonation and will return when operations are completed. 
Thus, it is anticipated that the quantity of fish affected will be 
small and will not imperil any fish populations. In addition, most fish 
species experience large number of natural mortalities, especially 
during early life-stages, and any small level of mortality caused by 
the NSWC PCD's limited RDT&E activities involving the explosive 
detonations will likely be insignificant to the population as a whole.

Proposed Mitigation Measures

    In order to issue an incidental take authorization (ITA) under 
Section 101(a)(5)(A) of the MMPA, NMFS must set forth the ``permissible 
methods of taking pursuant to such activity, and other means of 
effecting the least practicable adverse impact on such species or stock 
and its habitat, paying particular attention to rookeries, mating 
grounds, and areas of similar significance.'' The National Defense 
Authorization Act (NDAA) of 2004 amended the MMPA as it relates to 
military-readiness activities and the incidental take authorization 
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 
mission activities described in the NSWC PCD LOA application and LOA 
Addendum are considered military readiness activities.
    In addition, any mitigation measure prescribed by NMFS should be 
known to accomplish, have a reasonable likelihood of accomplishing 
(based on current science), or contribute to the accomplishment of one 
or more of the general goals listed below:
    (a) Avoidance or minimization of injury or death of marine mammals 
wherever possible (goals b, c, and d may contribute to this goal).
    (b) A reduction in the numbers of marine mammals (total number or 
number at a biologically important time or location) exposed to 
received levels of underwater detonations or other activities expected 
to result in the take of marine mammals (this goal may contribute to a, 
above, or to reducing harassment takes only).
    (c) A reduction in the number of times (total number or number at 
biologically important time or location) individuals would be exposed 
to received levels of underwater detonations or other activities 
expected to result in the take of marine mammals (this goal may 
contribute to a, above, or to reducing harassment takes only).
    (d) A reduction in the intensity of exposures (either total number 
or number at biologically important time or location) to received 
levels of 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) A reduction in adverse effects to marine mammal habitat, paying 
special attention to the food base, activities that block or limit 
passage to or from biologically important areas, permanent destruction 
of habitat, or temporary destruction/disturbance of habitat during a 
biologically important time.
    (f) For monitoring directly related to mitigation--an increase in 
the probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation (shut-down zone, etc.).
    NMFS worked with the Navy and identified potential practicable and 
effective mitigation measures, which included 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 ``military-readiness activity''. 
These mitigation measures are listed below.

Proposed Mitigation Measures for HFAS/MFAS Operations

    Current protective measures employed by the Navy include applicable 
training of personnel and implementation of activity specific 
procedures resulting in minimization and/or avoidance of interactions 
with protected resources.
    The Navy includes marine species awareness as part of its training 
for its Navy personnel on vessels. Marine Species Awareness Training 
(MSAT) was updated in 2005, and the additional training materials are 
now included as required training for Navy marine observers. This 
training addresses the marine observer's (equivalent to lookout or 
watchstander in other Navy actions) role in environmental protection, 
laws governing the protection of marine species, Navy stewardship 
commitments, and general observation information to aid in avoiding 
interactions with marine species. Marine species awareness and training 
is reemphasized by the following means:
     Marine observers--Personnel are required to utilize marine 
species awareness training techniques as standard operating procedure, 
have available a marine species visual identification aid when marine 
mammals are sighted, and receive updates to the current marine species 
awareness training as appropriate.
    Implementation of these protective measures is required of all 
units. The activities undertaken on a Navy vessel or aircraft are 
highly controlled. The chain of command supervises these activities. 
Failure to follow orders can result in disciplinary action.
Personnel Training
    1. All marine observers onboard platforms involved in the mission 
activities will review the NMFS-approved MSAT material prior to use of 
mid- and high-frequency active sonar.
    2. Navy marine observers will undertake extensive training in order 
to qualify as a watchstander in accordance with the Lookout Training 
Handbook (NAVEDTRA, 12968-D).

[[Page 20184]]

    3. Marine observer training will include on-the-job instruction 
under the supervision of a qualified, experienced watchstander. 
Following successful completion of this supervised training period, 
Marine observers will complete the Personal Qualification Standard 
program, certifying that they have demonstrated the necessary skills 
(such as detection and reporting of partially submerged objects). This 
does not forbid personnel being trained as marine observers from being 
counted as those listed in previous measures so long as supervisors 
monitor their progress and performance.
    4. Marine observers will be trained in the most effective means to 
ensure quick and effective communication within the command structure 
in order to facilitate implementation of mitigation measures if marine 
species are spotted.
Marine Observer Responsibilities
    1. On the bridge of surface vessels, there will always be at least 
one to three persons (depending on the length of the vessel) on watch 
whose duties include observing the water surface around the vessel.
    Manned motor-driven vessels with length overall less than 65 ft (20 
m) would require at least one marine species awareness trained 
observer; vessels with length overall between 65-200 ft (20-61 m) would 
require at least two marine species awareness trained observers; and 
vessels with length overall over 200 ft (61 m) would require at least 3 
marine species awareness trained observers.
    2. Each marine observer will have at their disposal at least one 
set of binoculars available to aid in the detection of marine mammals.
    3. On surface vessels equipped with the AN/SQQ-53C/56, pedestal 
mounted ``Big Eye'' (20 x 110) binoculars will be present and in good 
working order to assist in the detection of marine mammals in the 
vicinity of the vessel.
    4. Marine observers will employ visual search procedures employing 
a scanning methodology in accordance with the Lookout Training Handbook 
(NAVEDTRA 12968-D).
    5. Marine observers would scan the water from the vessel to the 
horizon and be responsible for all contacts in their sector. In 
searching the assigned sector, the marine observer would always start 
at the forward part of the sector and search aft (toward the back). To 
search and scan, the marine observer would hold the binoculars steady 
so the horizon is in the top third of the field of vision and direct 
the eyes just below the horizon. The marine observer would scan for 
approximately five seconds in as many small steps as possible across 
the field seen through the binoculars. They would search the entire 
sector in approximately five-degree steps, pausing between steps for 
approximately five seconds to scan the field of view. At the end of the 
sector search, the glasses would be lowered to allow the eyes to rest 
for a few seconds, and then the marine observer would search back 
across the sector with the naked eye.
    6. After sunset and prior to sunrise, marine observers will employ 
Night Lookout Techniques in accordance with the Lookout Training 
Handbook.
    7. At night, marine observers would not sweep the horizon with 
their eyes because eyes do not see well when they are moving. Marine 
observers would scan the horizon in a series of movements that would 
allow their eyes to come to periodic rests as they scan the sector. 
When visually searching at night, they would look a little to one side 
and out of the corners of their eyes, paying attention to the things on 
the outer edges of their field of vision.
    8. Marine observers will be responsible for reporting all objects 
or anomalies sighted in the water (regardless of the distance from the 
vessel) to the Test Director or the Test Director's designee, since any 
object or disturbance (e.g., trash, periscope, surface disturbance, 
discoloration) in the water may be indicative of a threat to the vessel 
and its crew or indicative of a marine species that may need to be 
avoided as warranted.
Operating Procedures
    1. A Record of Environmental Consideration will be included in the 
Test Plan prior to the test event to further disseminate the personnel 
testing requirement and general marine mammal mitigation measures.
    2. Test Directors will make use of marine species detection cues 
and information to limit interaction with marine species to the maximum 
extent possible consistent with safety of the vessel.
    3. All personnel engaged in passive acoustic sonar operation 
(including aircraft or surface vessels) will monitor for marine mammal 
vocalizations and report the detection of any marine mammal to the 
appropriate watch station for dissemination and appropriate action.
    4. During mid- and high frequency active sonar activities, 
personnel will utilize all available sensor and optical systems (such 
as Night Vision Goggles) to aid in the detection of marine mammals.
    5. Navy aircraft participating in exercises at sea will conduct and 
maintain, when operationally feasible and safe, surveillance for marine 
species of concern as long as it does not violate safety constraints or 
interfere with the accomplishment of primary operational duties.
    6. Aircraft with deployed sonobuoys will use only the passive 
capability of sonobuoys when marine mammals are detected within 200 
yards of the sonobuoy.
    7. Marine mammal detections will be immediately reported to 
assigned Test Director or the Test Director's designee for further 
dissemination to vessels in the vicinity of the marine species as 
appropriate where it is reasonable to conclude that the course of the 
vessel will likely result in a closing of the distance to the detected 
marine mammal.
    8. Safety Zones--When marine mammals are detected by any means 
(aircraft, marine observer, or acoustically) the Navy will ensure that 
HFAS/MFAS transmission levels are limited to at least 6 dB below normal 
operating levels if any detected marine mammals are within 1,000 yards 
(914 m) of the sonar dome (the bow).
    (1) Vessels will continue to limit maximum HFAS/MFAS transmission 
levels by this 6-dB factor until the marine mammal has been seen to 
leave the area, has not been detected for 30 minutes, or the vessel has 
transited more than 2,000 yards (1,828 m) beyond the location of the 
last detection.
    (2) The Navy will ensure that HFAS/MFAS transmissions will be 
limited to at least 10 dB below the equipment's normal operating level 
if any detected animals are within 500 yards (457 m) of the sonar dome. 
Vessels will continue to limit maximum ping levels by this 10-dB factor 
until the marine mammal has been seen to leave the area, has not been 
detected for 30 minutes, or the vessel has transited more than 2,000 
yards (1,828 m) beyond the location of the last detection.
    (3) The Navy will ensure that HFAS/MFAS transmissions are ceased if 
any detected marine mammals are within 200 yards (183 m) of the sonar 
dome. HFAS/MFAS will not resume until the marine mammal has been seen 
to leave the area, has not been detected for 30 minutes, or the vessel 
has transited more than 2,000 yards (1,828 m) beyond the location of 
the last detection.
    (4) Special conditions applicable for dolphins only: If, after 
conducting an initial maneuver to avoid close quarters with dolphins, 
the Test Director or the Test Director's designee concludes that 
dolphins are deliberately closing to ride

[[Page 20185]]

the vessel's bow wave, no further mitigation actions are necessary 
while the dolphins or porpoises continue to exhibit bow wave riding 
behavior.
    (5) If the need for power-down should arise as detailed in ``Safety 
Zones'' above, Navy shall follow the requirements as though they were 
operating at 235 dB--the normal operating level (i.e., the first power-
down will be to 229 dB, regardless of at what level above 235 sonar was 
being operated).
    9. Prior to start up or restart of active sonar, operators will 
check that the Safety Zone radius around the sound source is clear of 
marine mammals.
    10. Sonar levels (generally)--Navy will operate sonar at the lowest 
practicable level, not to exceed 235 dB, except as required to meet 
testing objectives.
    11. Helicopters shall observe/survey the vicinity of the mission 
activities for 10 minutes before the first deployment of active 
(dipping) sonar in the water.
    12. Helicopters shall not dip their sonar within 200 yards (183 m) 
of a marine mammal and shall cease pinging if a marine mammal closes 
within 200 yards (183 m) after pinging has begun.

Proposed Mitigation Measures for Ordnance and Projectile Firing

    To ensure protection of marine mammals during ordnance and 
projectile firing related underwater detonation mission activities, the 
operating area must be determined to be clear of marine mammals prior 
to detonation. Implementation of the following mitigation measures 
would ensure that marine mammals would not be exposed to TTS, PTS or 
injury from ordnance and projectile firing exercises.
     No detonations over 34 kg (75 lb) will be conducted in 
territorial waters. This does not apply to the line charge detonation, 
which is a 107 m (350 ft) detonation cord with explosives lined from 
one end to the other end in 2 kg (5 lb) increments and total 794 kg 
(1,750 lb) of NEW. This charge is considered one explosive source that 
has multiple increments that detonate at one time.
     The number of live mine detonations will be minimized and 
the smallest amount of explosive material possible to achieve test 
objectives will be used.
     Activities will be coordinated through the Environmental 
Help Desk to allow potential concentrations of detonations in a 
particular area over a short time to be identified and avoided.
     Visual surveys and aerial surveys will be conducted for 
all test operations that involve detonation events with for 30 minutes 
before and during the test event.
     Line charge tests would not be conducted during the 
nighttime.
     Additional mitigation will be determined through the NSWC 
PCD's Environmental Review Process review based on test activities 
including the size of detonations, test platforms, and environmental 
effects documented in the Navy's EIS/OEIS. Various zones of influence 
(ZOIs) from different ranges of NEW are shown in Table 8. As a 
mitigation measure, the largest ZOI associated with the upper limit of 
each NEW would be adopted as a clearance zone for such range of NEW. 
Therefore, for the following ranges of NEW, the clearance zones are: 
2,863 m for NEW between 76-600 lb, 997 m for NEW between 11-75 lb, and 
345 m for NEW under 11 lb.

Proposed Mitigation Measures for Surface Operations and Other 
Activities

    For surface operations, vessel-based visual surveys would be 
conducted for all test operations to reduce the potential for vessel 
collisions with a protected species.
    (a) While underway, vessels will have at least one to three marine 
species awareness trained observers (based on the length of the vessel) 
with binoculars. Manned motor-driven vessels with length overall less 
than 65 ft (20 m) would require at least one marine species awareness 
trained observer; vessels with length overall between 65-200 ft (20-61 
m) would require at least two marine species awareness trained 
observers; and vessels with length overall over 200 ft (61 m) would 
require at least three marine species awareness trained observers. As 
part of their regular duties, marine observers will watch for and 
report to the Test Director or Test Director's designee the presence of 
marine mammals.
    (b) Marine observers will employ visual search procedures employing 
a scanning method in accordance with the Lookout Training Handbook 
(NAVEDTRA 12968-D).
    (c) While in transit, naval vessels shall be alert at all times, 
use extreme caution, and proceed at a ``safe speed'' (the minimum speed 
at which mission goals or safety will not be compromised) so that the 
vessel can take proper and effective action to avoid a collision with 
any marine animal and can be stopped within a distance appropriate to 
the prevailing circumstances and conditions.
    (d) When marine mammals have been sighted in the area, Navy vessels 
will increase vigilance and implement measures to avoid collisions with 
marine mammals and avoid activities that might result in close 
interaction of naval assets and marine mammals. Actions shall include 
changing speed and/or direction and are dictated by environmental and 
other conditions (e.g., safety, weather).
    (e) Naval vessels will maneuver to keep at least 500 yd (460 m) 
away from any observed whale and avoid approaching whales head-on. This 
requirement does 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. Vessels will take reasonable steps to 
alert other vessels in the vicinity of the whale.
    (f) Where feasible and consistent with mission and safety, vessels 
will avoid closing to within 200 yards (183 m) of marine mammals other 
than whales (whales addressed above).
    (g) Floating weeds, algal mats, Sargassum rafts, clusters of 
seabirds, and jellyfish are good indicators of marine mammal presence. 
Therefore, increased vigilance in watching for marine mammals will be 
taken where these conditions exist.
    (h) All vessels will maintain logs and records documenting RDT&E 
activities should they be required for event reconstruction purposes. 
Logs and records will be kept for a period of 30 days following 
completion of a RDT&E mission activity.

Research and Conservation Measures for Marine Mammals

    The Navy provides a significant amount of funding and support for 
marine research. The Navy provided $26 million in Fiscal Year 2008 and 
plans for $22 million in Fiscal Year 2009 to universities, research 
institutions, Federal laboratories, private companies, and independent 
researchers around the world to study marine mammals. Over the past 
five years the Navy has funded over $100 million in marine mammal 
research. The U.S. Navy sponsors seventy percent of all U.S. research 
concerning the effects of human-generated sound on marine mammals and 
50 percent of such research conducted worldwide. Major topics of Navy-
supported research include the following:
     Better understanding of marine species distribution and 
important habitat areas,
     Developing methods to detect and monitor marine species 
before and during training,

[[Page 20186]]

     Understanding the effects of sound on marine mammals, sea 
turtles, fish, and birds, and
     Developing tools to model and estimate potential effects 
of sound.
    The Navy's Office of Naval Research currently coordinates six 
programs that examine the marine environment and are devoted solely to 
studying the effects of noise and/or the implementation of technology 
tools that will assist the Navy in studying and tracking marine 
mammals. The six programs are as follows:
     Environmental Consequences of Underwater Sound,
     Non-Auditory Biological Effects of Sound on Marine 
Mammals,
     Effects of Sound on the Marine Environment,
     Sensors and Models for Marine Environmental Monitoring,
     Effects of Sound on Hearing of Marine Animals, and
     Passive Acoustic Detection, Classification, and Tracking 
of Marine Mammals.
    Furthermore, research cruises by NMFS and by academic institutions 
have received funding from the Navy.
    The Navy has sponsored several workshops to evaluate the current 
state of knowledge and potential for future acoustic monitoring of 
marine mammals. The workshops brought together acoustic experts and 
marine biologists from the Navy and other research organizations to 
present data and information on current acoustic monitoring research 
efforts and to evaluate the potential for incorporating similar 
technology and methods on instrumented ranges. However, acoustic 
detection, identification, localization, and tracking of individual 
animals still requires a significant amount of research effort to be 
considered a reliable method for marine mammal monitoring. The Navy 
supports research efforts on acoustic monitoring and will continue to 
investigate the feasibility of passive acoustics as a potential 
mitigation and monitoring tool.
    Overall, the Navy will continue to fund ongoing marine mammal 
research, and is planning to coordinate long-term monitoring/studies of 
marine mammals on various established ranges and operating areas. The 
Navy will continue to research and contribute to university/external 
research to improve the state of the science regarding marine species 
biology and acoustic effects. These efforts include mitigation and 
monitoring programs; data sharing with NMFS and via the literature for 
research and development efforts.

Long-Term Prospective Study

    NMFS, with input and assistance from the Navy and several other 
agencies and entities, will perform a longitudinal observational study 
of marine mammal strandings to systematically observe for and record 
the types of pathologies and diseases and investigate the relationship 
with potential causal factors (e.g., sonar, seismic, weather). The 
study will not be a true ``cohort'' study, because we will be unable to 
quantify or estimate specific sonar or other sound exposures for 
individual animals that strand. However, a cross-sectional or 
correlational analysis, a method of descriptive rather than analytical 
epidemiology, can be conducted to compare population characteristics, 
e.g., frequency of strandings and types of specific pathologies between 
general periods of various anthropogenic activities and non-activities 
within a prescribed geographic space. In the long term study, we will 
more fully and consistently collect and analyze data on the 
demographics of strandings in specific locations and consider 
anthropogenic activities and physical, chemical, and biological 
environmental parameters. This approach in conjunction with true cohort 
studies (tagging animals, measuring received sounds, and evaluating 
behavior or injuries) in the presence of activities and non-activities 
will provide critical information needed to further define the impacts 
of MTEs and other anthropogenic and non-anthropogenic stressors. In 
coordination with the Navy and other federal and non-federal partners, 
the comparative study will be designed and conducted for specific sites 
during intervals of the presence of anthropogenic activities such as 
sonar transmission or other sound exposures and absence to evaluate 
demographics of morbidity and mortality, lesions found, and cause of 
death or stranding. Additional data that will be collected and analyzed 
in an effort to control potential confounding factors include variables 
such as average sea temperature (or just season), meteorological or 
other environmental variables (e.g., seismic activity), fishing 
activities, etc. All efforts will be made to include appropriate 
controls (i.e., no sonar or no seismic); environmental variables may 
complicate the interpretation of ``control'' measurements. The Navy and 
NMFS along with other partners are evaluating mechanisms for funding 
this study.

Proposed Monitoring Measures

    In order to issue an ITA for an activity, section 101(a)(5)(A) of 
the MMPA states that NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such taking.'' The MMPA implementing 
regulations at 50 CFR 216.104(a)(13) indicate that requests for LOAs 
must include the suggested means of accomplishing the necessary 
monitoring and reporting that will result in increased knowledge of the 
species and of the level of taking or impacts on populations of marine 
mammals that are expected to be present.
    Monitoring measures prescribed by NMFS should accomplish one or 
more of the following general goals:
    (a) An increase in the probability of detecting marine mammals, 
both within the safety zone (thus allowing for more effective 
implementation of the mitigation) and in general to generate more data 
to contribute to the analyses mentioned below.
    (b) An increase in our understanding of how many marine mammals are 
likely to be exposed to levels of HFAS/MFAS (or explosives or other 
stimuli) that we associate with specific adverse effects, such as 
behavioral harassment, TTS, or PTS.
    (c) An increase in our understanding of how marine mammals respond 
to HFAS/MFAS (at specific received levels), explosives, or other 
stimuli expected to result in take and how anticipated adverse effects 
on individuals (in different ways and to varying degrees) may impact 
the population, species, or stock (specifically through effects on 
annual rates of recruitment or survival) through any of the following 
methods:
     Behavioral observations in the presence of HFAS/MFAS 
compared to observations in the absence of sonar (need to be able to 
accurately predict received level and report bathymetric conditions, 
distance from source, and other pertinent information).
     Physiological measurements in the presence of HFAS/MFAS 
compared to observations in the absence of sonar (need to be able to 
accurately predict received level and report bathymetric conditions, 
distance from source, and other pertinent information), and/or
     Pre-planned and thorough investigation of stranding events 
that occur coincident to naval activities.
     Distribution and/or abundance comparisons in times or 
areas with concentrated HFAS/MFAS versus times or areas without HFAS/
MFAS.
    (d) An increased knowledge of the affected species.

[[Page 20187]]

    (e) An increase in our understanding of the effectiveness of 
certain mitigation and monitoring measures.
    With these goals in mind, the following monitoring procedures for 
the proposed Navy's NSWC PCD mission activities have been worked out 
between NMFS and the Navy. NMFS and the Navy continue to improve the 
plan and may modify the monitoring plan based on input received during 
the public comment period.
    Several monitoring techniques were prescribed for other Navy 
activities related to sonar exercises and underwater detonations (see 
monitoring plan for Navy's Hawaii Range Complex; Navy, 2008). Every 
known monitoring technique has advantages and disadvantages that vary 
temporally and spatially. Therefore, a combination of techniques are 
proposed to be used so that the detection and observation of marine 
animals is maximized. Monitoring methods proposed during mission 
activity events in the NSWC PCD Study Area include a combination of the 
following research elements that would be used to collection data for 
comprehensive assessment:
     Visual Surveys--Vessel, Aerial and Shore-based
     Passive Acoustic Monitoring (PAM)
     Marine Mammal Observers (MMOs) on Navy vessels

Visual Surveys--Vessel, Aerial and Shore-Based

    Visual surveys of marine animals can provide detailed information 
about the behavior, distribution, and abundance. Baseline measurements 
and/or data for comparison can be obtained before, during and after 
mission activities. Changes in behavior and geographical distribution 
may be used to infer if and how animals are impacted by sound. In 
accordance with all safety considerations, observations will be 
maximized by working from all available platforms: Vessels, aircraft, 
land and/or in combination. Vessel and aerial surveys will be conducted 
on commercial vessels and aircraft. Visual surveys will be conducted 
during Navy RDT&E events that have been identified as providing the 
highest likelihood of success.
    Vessel surveys are often preferred by researchers because of their 
slow speed, offshore survey ability, duration and ability to more 
closely approach animals under observation. They also result in higher 
rate of species identification, the opportunity to combine line 
transect and mark-recapture methods of estimating abundance, and 
collection of oceanographic and other relevant data. Vessels can be 
less expensive per unit of time, but because of the length of time to 
cover a given survey area, may actually be more expensive in the long 
run compared to aerial surveys (Dawson et al., 2008). Changes in 
behavior and geographical distribution may be used to infer if and how 
animals are impacted by sound. However, it should be noted that animal 
reaction (reactive movement) to the survey vessel itself is possible 
(Dawson et al., 2008). Vessel surveys typically do not allow for 
observation of animals below the ocean's surface (e.g., in the water 
column) as compared to aerial surveys (DoN, 2008a; Slooten et al., 
2004).
    For underwater detonations, the size of the survey area has been 
determined based upon the type of explosive event planned and the 
amount of NEW used. As a conservative measure, the largest ZOI 
associated with the upper limit of each NEW would be surveyed during 
the training event. For example, the Navy would be required to observe 
the following ZOIs and ensure they are clear of marine mammals prior to 
conducting explosive ordnance exercises: 2,863 m for NEW between 76-600 
lb; 997 m for NEW between 11-75 lb; and 345 m for NEW under 11 lb.
    If animals are observed prior to or during an explosion, a focal 
follow of that individual or group will be conducted to record 
behavioral responses. Navy mitigation measures will prevent the mission 
activity from occurring should animals be seen within these ZOIs of the 
events listed above.
    The visual survey team will collect the same data that are 
collected by Navy marine observers, including but not limited to: (1) 
Location of sighting; (2) species; (3) number of individuals; (4) 
number of calves present, if any; (5) duration of sighting; (6) 
behavior of marine animals sighted; (7) direction of travel; (8) 
environmental information associated with sighting event including 
Beaufort sea state, wave height, swell direction, wind direction, wind 
speed, glare, percentage of glare, percentage of cloud cover; and (9) 
when in relation to navy exercises did the sighting occur (before, 
during or after detonations/exercise). Animal sightings and relative 
distance from a particular detonation site will be used post-survey to 
estimate the number of marine mammals exposed to different received 
levels (energy and pressure of discharge based on distance to the 
source, bathymetry, oceanographic conditions and the type and size of 
detonation) and their corresponding behavior. For vessel based surveys 
a passive acoustic system (hydrophone or towed array) or sonobuoys may 
be used to help determine if marine mammals are in the area before and 
after a detonation event.
    Although photo-identification studies are not typically a component 
of Navy exercise monitoring surveys, the Navy supports using the 
contracted platforms to obtain opportunistic data collection. 
Therefore, any digital photographs that are taken of marine mammals 
during visual surveys will be provided to local researchers for their 
regional research.
1. Aerial Surveys
    During sonar operations, an aerial survey team will fly transects 
relative to a Navy surface vessel that is transmitting HFA/MFA sonar. 
The aerial survey team will collect both visual sightings and 
behavioral observations of marine animals. These transect data will 
provide an opportunity to collect data of marine mammals at different 
received levels and their behavioral responses and movement relative to 
the Navy vessel's position. Surveys will include time with and without 
active sonar in order to compare density, geographical distribution and 
behavioral observations. After declassification, related sonar 
transmissions will be used to calculate exposure levels.
    Behavioral observation methods will involve three professionally 
trained marine mammal observers and a pilot. Two observers will observe 
behaviors, one with hand-held binoculars and one with the naked eye per 
Wursig et al. (1985) and Richardson et al. (1986). If there is more 
than one whale, each observer will record respirations of different 
animals, ideally from the same animal. In the case of large groups, 
e.g., of delphinids, group behavior, speed, orientation, etc., will be 
recorded as described in Smultea and W[uuml]rsig (1995). An observer 
will use a video camera to record behaviors in real time. Two external 
microphones will be input and attached to the video camera to record 
vocal behavioral descriptions on two different channels of the video 
camera. The videotape will be time-stamped and observers will also call 
out times. The third observer will record notes, environmental data, 
and operate a laptop connected to a GPS and the plane's altimeter.
    Detailed behavioral focal observations of cetaceans will be 
recorded, including the following variables where possible: Species, 
group size and composition (number of calves, etc.), latitude/
longitude, surface and dive durations and times, number and spacing/
times of respirations, conspicuous behaviors (e.g., breach, tail slap, 
etc.), behavioral states, orientation and changes in orientation, 
estimated group travel

[[Page 20188]]

speed, inter-individual distances, defecations, social interactions, 
aircraft speed, aircraft altitude, distance to focal group (using the 
plane's radar) and any unusual behaviors or apparent reactions 
following previously established protocol (Richardson et al., 1985; 
1986; 1990; Wursig et al., 1985; 1989; Smultea and W[uuml]rsig, 1995; 
Patenaude et al., 2002).
    In addition, to measure whether marine mammals are displaced 
geographically as a result of sonar operations, systematic line-
transect aerial surveys will be conducted on the two days before and a 
variation of one to five days after a NSWC PCD RDT&E testing activity 
to collect relative density data in the testing area for marine mammals 
in the area. Attempts will be made to survey during a test event, but 
safety of navigation for the survey vessel may preclude conduction this 
kind of survey during certain NSWC PCD RDT&E activities. Rationale 
supporting variation in the number of days after a test event allows 
for detection of animals that gradually return to an area, if their 
distribution changes as a response. One survey day following the 
mission activity event will be devoted to flying coastlines nearest the 
mission event to look for potential marine mammal strandings. If a 
stranding is observed, an assessment of the animal's condition (alive, 
injured, dead, and/or decayed) will be immediately reported to the Navy 
for appropriate action and the information will be transmitted 
immediately to NMFS.
2. Vessel Surveys
    The primary purpose of vessel surveys will be to document and 
monitor potential behavioral effects of the mission activities on 
marine mammals. As such, parameters to be monitored for potential 
effects are changes in the occurrence, distribution, numbers, surface 
behavior, and/or disposition (injured or dead) of marine mammal species 
before, during and after the mission activities. While challenging, the 
vessel surveys will attempt to conduct focal follows on animals with 
Navy vessels in view.
    As with the aerial surveys, the vessel surveys will be designed to 
maximize detections of any target species near mission activity events 
for focal follows. Systematic transects will be used to locate marine 
mammals, however, the survey should deviate from transect protocol to 
collect behavioral data particularly if a Navy vessel is visible on the 
horizon or closer. At this point, they will approach within three 
nautical miles of the vessel(s), if weather and conditions allow, and 
will work in `focal follow mode' (e.g. collect behavioral data using 
the big eyes, and observe the behavior of any animals that are seen). 
The team will go off effort for photo-id and close approach `focal 
animal follows' as feasible, and when marine animal encounters occur in 
proximity to the vessel. While in focal follow mode, observers will 
gather detailed behavioral data from the animals, for as long as the 
animal allows. Analysis of behavioral observations will be made after 
the RDT&E event (Altman, 1974; Martin and Bateson, 1993). While the 
Navy vessels are within view, attempts will be made to position the 
dedicated survey vessel in the best possible way to obtain focal follow 
data in the presence of the NSWC PCD test event. If Navy vessels are 
not in view, then the vessel will begin a systematic line transect 
survey within the area to assess marine mammal occurrence and observe 
behavior. The goal of this part of the survey is to observe marine 
mammals that may not have been exposed to HFAS/MFAS or explosions. 
Therefore, post-analysis will focus on how the location, speed and 
vector of the survey vessel and the location and direction of the sonar 
source (e.g., Navy surface vessel) relates to the animal. Any other 
vessels or aircraft observed in the area will also be documented.
3. Shore-Based Surveys
    If explosive events are planned in advance to occur adjacent to 
nearshore areas where there are elevated coastal structures (e.g. 
lookout tower at Eglin Air Force Base) or topography, then shore-based 
monitoring, using binoculars or theodolite, may be used to augment 
other visual survey methods. These methods have been proven valuable in 
similar monitoring studies such as ATOC and others (Frankel and Clark, 
1998; Clark and Altman, 2006).

Passive Acoustic Monitoring

    There are both benefits and limitations to passive acoustic 
monitoring (Mellinger et al., 2007). Passive acoustic monitoring allows 
detection of marine mammals that may not be seen during a visual 
survey. When interpreting data collected from PAM, it is understood 
that species specific results must be viewed with caution because not 
all animals within a given population are calling, or may be calling 
only under certain conditions (Mellinger, 2007; ONR, 2007). Because the 
NSWC PCD study area does not have some of the advanced features that 
the South Atlantic Range and Atlantic Undersea Testing and Evaluation 
Center have, allowing for the potential to track real-time, passive 
acoustic monitoring in the NSWC PCD will utilize a stationary, bottom-
set hydrophone array for PAM.
    The array would be deployed for each of the days the ship is at 
sea. NSWC PCD has a bottom set hydrophone array, which can detect 
marine mammals that vocalize and would be used to supplement the ship 
based systematic line transect surveys (particularly for species such 
as beaked whales that are rarely seen). The array would need to detect 
low frequency vocalizations (less than 1,000 Hertz) for baleen whales 
and relatively high frequency vocalizations (up to 30 kilohertz) for 
odontocetes such as sperm whales.

Marine Mammal Observers on Navy Vessels

    Civilian Marine Mammal Observers (MMOs) aboard Navy vessels will be 
used to research the effectiveness of Navy marine observers, as well as 
for data collection during other monitoring surveys.
    MMOs will be field-experienced observers that are Navy biologists 
or contracted observers. These civilian MMOs will be placed alongside 
existing Navy marine observers during a sub-set of NSWC PCD RDT&E 
activities. This can only be done on certain vessels and observers may 
be required to have security clearance. Use of MMOs will verify Navy 
marine observer sighting efficiency, offer an opportunity for more 
detailed species identification, provide an opportunity to bring animal 
protection awareness to the vessels' crew, and provide the opportunity 
for an experienced biologist to collect data on marine mammal behavior. 
Data collected by the MMOs is anticipated to assist the Navy with 
potential improvements to marine observer training as well as providing 
the marine observers with a chance to gain additional knowledge on 
marine mammals.
    Events selected for MMO participation will be an appropriate fit in 
terms of security, safety, logistics, and compatibility with NSWC PCD 
RDT&E activities. The MMOs will not be part of the Navy's formal 
reporting chain of command during their data collection efforts and 
Navy marine observers will follow their chain of command in reporting 
marine mammal sightings. Exceptions will be made if an animal is 
observed by the MMO within the shutdown zone and was not seen by the 
Navy marine observer. The MMO will inform the marine observer of the 
sighting so that appropriate action may be taken by the chain of 
command. For less biased data, it is recommended that

[[Page 20189]]

MMOs should schedule their daily observations to duplicate the Navy 
marine observers' schedule.
    Civilian MMOs will be aboard Navy vessels involved in the study. As 
described earlier, MMOs will meet and adhere to necessary 
qualifications, security clearance, logistics and safety concerns. MMOs 
will monitor for marine mammals from the same height above water as the 
marine observers and as all visual survey teams, they will collect the 
same data collected by Navy marine observers, including but not limited 
to: (1) Location of sighting; (2) species (if not possible, 
identification of whale or dolphin); (3) number of individuals; (4) 
number of calves present, if any; (5) duration of sighting; (6) 
behavior of marine animals sighted; (7) direction of travel; (8) 
environmental information associated with sighting event including 
Beaufort sea state, wave height, swell direction, wind direction, wind 
speed, glare, percentage of glare, percentage of cloud cover; and (9) 
when in relation to navy exercises did the sighting occur (before, 
during or after detonations/exercise).
    In addition, the Navy is developing an Integrated Comprehensive 
Monitoring Program (ICMP) for marine species to assess the effects of 
NSWC PCD RDT&E activities on marine species and investigate population 
trends in marine species distribution and abundance in locations where 
NSWC PCD RDT&E activities regularly occurs.
    The ICMP will provide the overarching coordination that will 
support compilation of data from range-specific monitoring plans (e.g., 
NSWC PCD plan) as well as Navy funded research and development (R&D) 
studies. The ICMP will coordinate the monitoring programs progress 
towards meeting its goals and develop a data management plan. The ICMP 
will be evaluated annually to provide a matrix for progress and goals 
for the following year, and will make recommendations on adaptive 
management for refinement and analysis of the monitoring methods.
    The primary objectives of the ICMP are to:
     Monitor and assess the effects of Navy activities on 
protected species;
     Ensure that data collected at multiple locations is 
collected in a manner that allows comparison between and among 
different geographic locations;
     Assess the efficacy and practicality of the monitoring and 
mitigation techniques;
     Add to the overall knowledge-base of marine species and 
the effects of Navy activities on marine species.
    The ICMP will be used both as: (1) a planning tool to focus Navy 
monitoring priorities (pursuant to ESA/MMPA requirements) across Navy 
Range Complexes and Exercises; and (2) an adaptive management tool, 
through the consolidation and analysis of the Navy's monitoring and 
watchstander data, as well as new information from other Navy programs 
(e.g., R&D), and other appropriate newly published information.
    In combination with the adaptive management component of the 
proposed NSWC PCD rule and the other planned Navy rules (e.g., Atlantic 
Fleet Active Sonar Training, Hawaii Range Complex, and Southern 
California Range Complex), the ICMP could potentially provide a 
framework for restructuring the monitoring plans and allocating 
monitoring effort based on the value of particular specific monitoring 
proposals (in terms of the degree to which results would likely 
contribute to stated monitoring goals, as well as the likely technical 
success of the monitoring based on a review of past monitoring results) 
that have been developed through the ICMP framework, instead of 
allocating based on maintaining an equal (or commensurate to effects) 
distribution of monitoring effort across Range complexes. For example, 
if careful prioritization and planning through the ICMP (which would 
include a review of both past monitoring results and current scientific 
developments) were to show that a large, intense monitoring effort in 
GOM would likely provide extensive, robust and much-needed data that 
could be used to understand the effects of sonar throughout different 
geographical areas, it may be appropriate to have other Range Complexes 
dedicate money, resources, or staff to the specific monitoring proposal 
identified as ``high priority'' by the Navy and NMFS, in lieu of 
focusing on smaller, lower priority projects divided throughout their 
home Range Complexes. The ICMP will identify:
     A means by which NMFS and the Navy would jointly consider 
prior years' monitoring results and advancing science to determine if 
modifications are needed in mitigation or monitoring measures to better 
effect the goals laid out in the Mitigation and Monitoring sections of 
the NSWC PCD rule.
     Guidelines for prioritizing monitoring projects.
     If, as a result of the workshop and similar to the example 
described in the paragraph above, the Navy and NMFS decide it is 
appropriate to restructure the monitoring plans for multiple ranges 
such that they are no longer evenly allocated (by Range Complex), but 
rather focused on priority monitoring projects that are not necessarily 
tied to the geographic area addressed in the rule, the ICMP will be 
modified to include a very clear and unclassified record-keeping system 
that will allow NMFS and the public to see how each Range Complex/
project is contributing to all of the ongoing monitoring (resources, 
effort, money, etc.).

Adaptive Management

    Our understanding of the effects of HFAS/MFAS on marine mammals is 
still in its relative infancy, and yet the science in this field is 
evolving fairly quickly. These circumstances make the inclusion of an 
adaptive management component both valuable and necessary within the 
context of 5-year regulations for activities that have been associated 
with marine mammal mortality in certain circumstances and locations 
(though not the NSWC PCD Study Area). The use of adaptive management 
will give NMFS the ability to consider new data from different sources 
to determine (in coordination with the Navy), on an annual basis, if 
new or modified mitigation or monitoring measures are appropriate for 
subsequent annual LOAs. Following are some of the possible sources of 
applicable data:
     Results from the Navy's monitoring from the previous year 
(either from the NSWC PCD Study Area or other locations).
     Results from specific stranding investigations (either 
from the NSWC PCD Study Area or other locations, and involving 
coincident NSWC PCD RDT&E or not involving coincident use).
     Results from the research activities associated with 
Navy's HFAS/MFAS.
     Results from general marine mammal and sound research 
(funded by the Navy or otherwise).
     Any information which reveals that marine mammals may have 
been taken in a manner, extent or number not authorized by these 
regulations or subsequent Letters of Authorization.
    Mitigation measures could be modified or added if new data suggest 
that such modifications would have a reasonable likelihood of 
accomplishing the goals of mitigation laid out in this proposed rule 
and if the measures are practicable. NMFS would also coordinate with 
the Navy to modify or add to the existing monitoring requirements if 
the new data suggest that the addition of a particular measure would 
more effectively accomplish the goals of monitoring laid out in this 
proposed rule. The reporting requirements associated with this proposed 
rule are designed to provide

[[Page 20190]]

NMFS with monitoring data from the previous year to allow NMFS to 
consider the data in issuing annual LOAs. NMFS and the Navy will meet 
annually prior to LOA issuance to discuss the monitoring reports, Navy 
R&D developments, and current science and whether mitigation or 
monitoring modifications are appropriate.

Reporting

    In order to issue an ITA for an activity, section 101(a)(5)(A) of 
the MMPA states that NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such taking.'' Effective reporting is 
critical both to compliance as well as ensuring that the most value is 
obtained from the required monitoring. Some of the reporting 
requirements are still in development and the final rule may contain 
additional details not contained in the proposed rule. Additionally, 
proposed reporting requirements may be modified, removed, or added 
based on information or comments received during the public comment 
period.

General Notification of Injured or Dead Marine Mammals

    Navy personnel will ensure that NMFS (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 mission activities 
utilizing MFAS, HFAS, or underwater explosive detonations. The Navy 
will provide NMFS with species or description of the animal(s), the 
condition of the animal(s) (including carcass condition if the animal 
is dead), location, time of first discovery, observed behaviors (if 
alive), and photo or video (if available). The Stranding Response Plan 
contains more specific reporting requirements for specific 
circumstances.

Annual Report

    The Navy will submit its first annual report to the Office of 
Protected Resources, NMFS, no later than 120 days before the expiration 
of the LOA. These reports will, at a minimum, include the following 
information:

     The estimated number of hours of sonar operation, broken 
down by source type.
     If possible, the total number of hours of observation 
effort (including observation time when sonar was not operating).
     A report of all marine mammal sightings (at any distance--
not just within a particular distance) to include, when possible and to 
the best of their ability, and if not classified:

--Species.
--Number of animals sighted.
--Location of marine mammal sighting.
--Distance of animal from any operating sonar sources.
--Whether animal is fore, aft, port, starboard.
--Direction animal is moving in relation to source (away, towards, 
parallel).
--Any observed behaviors of marine mammals.

     The status of any sonar sources (what sources were in use) 
and whether or not they were powered down or shut down as a result of 
the marine mammal observation.
     The platform that the marine mammals were sighted from.

NSWC PCD Comprehensive Report

    The Navy will submit to NMFS a draft report that analyzes and 
summarizes all of the multi-year marine mammal information gathered 
during HFAS/MFAS and underwater detonation related mission activities 
for which annual reports are required as described above. This report 
will be submitted at the end of the fourth year of the rule (March 
2013), covering activities that have occurred through October 1, 2012. 
The Navy will respond to NMFS comments on the draft comprehensive 
report if submitted within 3 months of receipt. The report will be 
considered final after the Navy has addressed NMFS' comments, or three 
months after the submittal of the draft if NMFS does not comment by 
then.

Analysis and Negligible Impact Determination

    Pursuant to NMFS' regulations implementing the MMPA, an applicant 
is required to estimate the number of animals that will be ``taken'' by 
the specified activities (i.e., takes by harassment only, or takes by 
harassment, injury, and/or death). This estimate informs the analysis 
that NMFS must perform to determine whether the activity will have a 
``negligible impact'' on the species or stock. Level B (behavioral) 
harassment occurs at the level of the individual(s) and does not assume 
any resulting population-level consequences, though there are known 
avenues through which behavioral disturbance of individuals can result 
in population-level effects. A negligible impact finding is based on 
the lack of likely adverse effects on annual rates of recruitment or 
survival (i.e., population-level effects). An estimate of the number of 
Level B harassment takes, alone, is not enough information on which to 
base an impact determination. In addition to considering estimates of 
the number of marine mammals that might be ``taken'' through behavioral 
harassment, NMFS must consider other factors, such as the likely nature 
of any responses (their intensity, duration, etc.), the context of any 
responses (critical reproductive time or location, migration, etc.), or 
any of the other variables mentioned in the first paragraph (if known), 
as well as the number and nature of estimated Level A takes, the number 
of estimated mortalities, and effects on habitat.
    The Navy's specified activities have been described based on best 
estimates of the number of HFAS/MFAS hours that the Navy will conduct 
and the planned detonation events. Taking the above into account, 
considering the sections discussed below, and dependent upon the 
implementation of the proposed mitigation measures, NMFS has 
preliminarily determined that Navy's RDT&E activities utilizing HFAS/
MFAS and underwater detonations will have a negligible impact on the 
marine mammal species and stocks present in the NSWC PCD Study Area.

Behavioral Harassment

    As discussed in the Potential Effects of Exposure of Marine Mammals 
to HFAS/MFAS and illustrated in the conceptual framework, marine 
mammals can respond to HFAS/MFAS in many different ways, a subset of 
which qualifies as harassment. One thing that the take estimates do not 
take into account is the fact that most marine mammals will likely 
avoid strong sound sources to one extent or another. Although an animal 
that avoids the sound source will likely still be taken in some 
instances (such as if the avoidance results in a missed opportunity to 
feed, interruption of reproductive behaviors, etc.) in other cases 
avoidance may result in fewer instances of take than were estimated or 
in the takes resulting from exposure to a lower received level than was 
estimated, which could result in a less severe response. The Navy 
proposes only 77 hours of mid-frequency sonar operations per year 
(Table 2) in the NSWC PCD Study Area, and the use of the most powerful 
53C series sonar will be limited to just 4 hours per year. Therefore, 
any disturbance to marine mammals resulting from 53C and other MFAS is 
expected to be significantly less in terms of severity and duration 
when compared to major sonar exercises (e.g., AFAST, HRC, SOCAL). As 
for the HFAS, source levels of those HFAS are not as high as the 53C 
series MFAS. In addition, high frequency signals tend to

[[Page 20191]]

have more attenuation in the water column and are more prone to lose 
their energy during propagation. Therefore, their zones of influence 
are much smaller, thereby making it easier to detect marine mammals and 
prevent adverse effects from occurring.
    There is little information available concerning marine mammal 
reactions to MFAS/HFAS. The Navy has only been conducting monitoring 
activities since 2006 and has not compiled enough data to date to 
provide a meaningful picture of effects of HFAS/MFAS on marine mammals, 
particularly in the NSWC PCD Study Area. From the four major training 
exercises (MTEs) of HFAS/MFAS in the AFAST Study Area for which NMFS 
has received a monitoring report, no instances of obvious behavioral 
disturbance were observed by the Navy watchstanders in the 700+ hours 
of effort in which 79 sightings of marine mammals were made (10 during 
active sonar operation). One cannot conclude from these results that 
marine mammals were not harassed from HFAS/MFAS, 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 sp.) and 
some of the non-biologist watchstanders might not have had the 
expertise to characterize behaviors. However, the data demonstrate that 
the animals that were observed did not respond in any of the obviously 
more severe ways, such as panic, aggression, or anti-predator response.
    In addition to the monitoring that will be required pursuant to 
these regulations and subsequent LOAs, which is specifically designed 
to help us better understand how marine mammals respond to sound, the 
Navy and NMFS have developed, funded, and begun conducting a controlled 
exposure experiment with beaked whales in the Bahamas.

Diel Cycle

    As noted previously, many animals perform vital functions, such as 
feeding, resting, traveling, and socializing on a diel cycle (24-hr 
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 one day 
and not recurring on subsequent days is not considered particularly 
severe unless it could directly affect reproduction or survival 
(Southall et al., 2007).
    In the previous section, we discussed the fact that potential 
behavioral responses to HFAS/MFAS and underwater detonations that fall 
into the category of harassment could range in severity. By definition, 
the takes by behavioral harassment involve the disturbance of a marine 
mammal or marine mammal stock in the wild by causing disruption of 
natural behavioral patterns (such as migration, surfacing, nursing, 
breeding, feeding, or sheltering) to a point where such behavioral 
patterns are abandoned or significantly altered. These reactions would, 
however, be more of a concern if they were expected to last over 24 
hours or be repeated in subsequent days. For hull-mounted sonar 53C 
series sonar (the highest power source), the total time of operation is 
only 4 hours per year, with 3 hours planned in territorial waters and 1 
hour in non-territorial waters. Different sonar testing and underwater 
detonation activities will not occur simultaneously. When this is 
combined with the fact that the majority of the cetaceans in the NSWC 
PCD Study Area would not likely remain in the same area for successive 
days, it is unlikely that animals would be exposed to HFAS/MFAS and 
underwater detonations at levels or for a duration likely to result in 
a substantive response that would then be carried on for more than one 
day or on successive days.

TTS

    NMFS and the Navy have estimated that individuals of some species 
of marine mammals may sustain some level of TTS from HFAS/MFAS and/or 
underwater detonation. As mentioned previously, TTS can last from a few 
minutes to days, be of varying degree, and occur across various 
frequency bandwidths. The TTS sustained by an animal is primarily 
classified by three characteristics:
     Frequency--Available data (of mid-frequency hearing 
specialists exposed to mid to high frequency sounds--Southall et al., 
2007) suggest that most TTS occurs in the frequency range of the source 
up to one octave higher than the source (with the maximum TTS at \1/2\ 
octave above).
     Degree of the shift (i.e., how many dB is the sensitivity 
of the hearing reduced by)--generally, both the degree of TTS and the 
duration of TTS will be greater if the marine mammal is exposed to a 
higher level of energy (which would occur when the peak dB level is 
higher or the duration is longer). The threshold for the onset of TTS 
(>6 dB) for Navy sonars is 195 dB (SEL), which might be received at 
distances of up to 275-500 m from the most powerful MFAS source, the 
AN/SQS-53 (the maximum ranges to TTS from other sources would be less). 
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 marine observers 
and the nominal speed of a sonar vessel (10-12 knots). Of all TTS 
studies, some using exposures of almost an hour in duration or up to 
217 SEL, most of the TTS induced was 15 dB or less, though Finneran et 
al. (2007) induced 43 dB of TTS with a 64-sec exposure to a 20 kHz 
source (MFAS emits a 1-s ping 2 times/minute). The threshold for the 
onset of TTS for detonations is a dual criteria: 182 dB re 1 
microPa\2\-sec or 23 psi, which might be received at distances from 
345-2,863 m from the centers of detonation based on the types of NEW 
involved.
     Duration of TTS (Recovery time)--see above. Of all TTS 
laboratory studies, some using exposures of almost an hour in duration 
or up to 217 SEL, almost all recovered within 1 day (or less, often in 
minutes), though in one study (Finneran et al., 2007), recovery took 4 
days.
    Based on the range of degree and duration of TTS reportedly induced 
by exposures to non-pulse sounds of energy higher than that to which 
free-swimming marine mammals in the field are likely to be exposed 
during HFAS/MFAS testing activities, it is unlikely that marine mammals 
would sustain a TTS from MFAS that alters their sensitivity by more 
than 20 dB for more than a few days (and the majority would be far less 
severe). 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 were 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 more 
likely be sustained because the higher source level and slower 
attenuation make it more likely that an animal would be exposed to a 
higher level) would not usually span the entire frequency range of one 
vocalization type, much less span all types of vocalizations.
    For underwater detonations, due to its brief impulse of sounds, 
animals have to be at distances from 345-2,863 m from the center of 
detonation, based on the types of NEW involved to receive the

[[Page 20192]]

SEL that causes TTS compared to similar source level with longer 
durations (such as sonar signals).

Acoustic Masking or Communication Impairment

    As discussed above, it is also possible that anthropogenic sound 
could result in masking of marine mammal communication and navigation 
signals. However, masking only occurs during the time of the signal 
(and potential secondary arrivals of indirect rays), versus TTS, which 
occurs continuously for its duration. Standard HFAS/MFAS sonar pings 
last on average one second and occur about once every 24-30 seconds for 
hull-mounted sources. When hull-mounted sonar is used in the Kingfisher 
mode, pulse length is shorter, but pings are much closer together (both 
in time and space, since the vessel goes slower when operating in this 
mode). For the sources for which we know the pulse length, most are 
significantly shorter than hull-mounted sonar, on the order of several 
microseconds to 10s of micro seconds. For hull-mounted sonar, though 
some of the vocalizations that marine mammals make are less than one 
second long, there is only a 1 in 24 chance that they would occur 
exactly when the ping was received, and when vocalizations are longer 
than one second, only parts of them are masked. Alternately, when the 
pulses are only several microseconds long, the majority of most 
animals' vocalizations would not be masked. Masking effects from HFAS/
MFAS are expected to be minimal. Likewise, the masking effects from 
underwater detonation are also considered to be unlikely due to the 
much shorter impulsive signals from explosions. If masking or 
communication impairment were to occur briefly, it would be in the 
frequency range of MFAS, which overlaps with some marine mammal 
vocalizations; however, it would likely not mask the entirety of any 
particular vocalization or communication series because the pulse 
length, frequency, and duty cycle of the HFAS/MFAS signal does not 
perfectly mimic the characteristics of any marine mammal's 
vocalizations.

PTS, Injury, or Mortality

    The Navy's model estimated that 1 individual of bottlenose dolphin 
and 1 individual of Atlantic spotted dolphin could experience severe 
lung injury (i.e., mortality) from explosive ordnance activities; and 1 
individual each of bottlenose, Atlantic spotted, pantropical spotted, 
and spinner dolphins from slight lung injury (Level A harassment) as a 
result of the underwater detonation exposures in the range of 76-272 lb 
NEW (34-272 kg) in non-territorial waters per year. However, these 
estimates do not take into consideration the proposed mitigation 
measures. For sonar operations, NMFS believes that many marine mammals 
would deliberately avoid exposing themselves to the received levels 
necessary to induce injury (i.e., approaching to within approximately 
10 m (10.9 yd) of the source). Animals would likely move away from or 
at least modify 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/power-down zones for HFAS/MFAS) further ensure that animals 
would be not be exposed to injurious levels of sound. As for underwater 
detonations, the animals have to be within the 203 m ZOI to experience 
severe lung injury or mortality. NMFS believes it is unlikely that Navy 
observers will fail to detect an animal in such a small area during 
pre-testing surveys. As discussed previously, the Navy plans to utilize 
aerial (when available) in addition to marine observers on vessels to 
detect marine mammals for mitigation implementation and indicated that 
they are capable of effectively monitoring safety zones. When these 
points are considered, NMFS does not believe that any marine mammals 
will experience severe lung injury or mortality from exposure to HFAS/
MFAS or underwater detonation. Instead, based on proposed mitigation 
and monitoring measures, NMFS preliminary determines that 2 individuals 
of bottlenose and Atlantic spotted dolphins, and 1 individual of 
pantropical spotted and spinner dolphins would receive slight lung 
injury (Level A harassment) as a result of underwater detonation 
exposures in the range of 76-272 lb NEW (34-272 kg) in non-territorial 
waters per year.
    Based on the aforementioned assessment, NMFS determines that 
approximately 2 sperm whales, 2 melon-headed whales, 1 short-finned 
pilot whale, 2 rough-toothed dolphins, 614 bottlenose dolphins, 471 
Atlantic spotted dolphins, 23 pantropical spotted dolphins, 5 striped 
dolphins, 23 spinner dolphins, and 5 Clymene dolphins would be affected 
by Level B harassment (TTS and sub-TTS) as a result of the proposed 
NSWC PCD RDT&E sonar and underwater detonation testing activities. 
These numbers represent approximately 0.12%, 0.08%, 0.14%, 0.07%, 
2.85%, 1.72%, 0.07%, 0.15%, 1.16%, and 0.08% of sperm whales, melon-
headed whales, short-finned pilot whale, rough-toothed dolphins, 
bottlenose dolphins, Atlantic spotted dolphins, pantropical spotted 
dolphins, striped dolphins, spinner dolphins, and Clymene dolphins, 
respectively in the vicinity of the proposed NSWC PCD Study Area 
(calculation based on NMFS 2007 US Atlantic and Gulf of Mexico Marine 
Mammal Stock Assessment).
    In addition, the Level A takes of 2 bottlenose, 2 Atlantic spotted, 
1 pantropical spotted, and 1 spinner dolphins represent 0.009%, 0.007%, 
0.003%, and 0.050% of these species in the vicinity of the proposed 
NSWC PCD Study Area (calculation based on NMFS 2007 US Atlantic and 
Gulf of Mexico Marine Mammal Stock Assessment).
    Based on the supporting analyses, which suggest that no marine 
mammals will be killed as a result of these activities, only 6 
individuals of dolphins (2 bottlenose, 2 Atlantic spotted, 1 
pantropical spotted, and 1 spinner dolphins) would experience injury 
(Level A harassment), and no more than a small percentage of the 
individuals of any affected species will be taken in the form of short-
term Level B harassment per year. Coupled with the fact that these 
impacts will likely not occur in areas and times critical to 
reproduction, NMFS has preliminarily determined that the total taking 
over the 5-year period of the regulations and subsequent LOAs from the 
Navy's NSWC PCD RDT&E mission activities will have a negligible impact 
on the marine mammal species and stocks present in the NSWC PCD Study 
Area.

Subsistence Harvest of Marine Mammals

    NMFS has preliminarily determined that the total taking of marine 
mammal species or stocks from the Navy's mission activities in the NSWC 
PCD study area would not have an unmitigable adverse impact on the 
availability of the affected species or stocks for subsistence uses, 
since there are no such uses in the specified area.

ESA

    There are six marine mammal species of which NMFS has jurisdiction 
that are listed as endangered under the ESA that could occur in the 
NSWC PCD study area: Humpback whale, North Atlantic right whale, blue 
whale, fin whale, sei whale, and sperm whale. The Navy has begun 
consultation with NMFS pursuant to section 7 of the ESA, and NMFS will 
also consult internally on the issuance of an LOA under section 
101(a)(5)(A) of the MMPA for mission activities in the NSWC PCD study 
area. Consultation will be concluded prior to

[[Page 20193]]

a determination on the issuance of the final rule and an LOA.

NEPA

    The Navy is preparing an Environmental Impact Statement (EIS) for 
the proposed NSWC PCD mission activities. A draft EIS was released for 
public comment from April 4-May 19, 2008 and is available at http://nswcpc.navsea.navy.mil/Environment-Documents.htm. NMFS is a cooperating 
agency (as defined by the Council on Environmental Quality (40 CFR 
1501.6)) in the preparation of the EIS. NMFS has reviewed the Draft EIS 
and will be working with the Navy on the Final EIS (FEIS).
    NMFS intends to adopt the Navy's FEIS, if adequate and appropriate, 
and we believe that the Navy's FEIS will allow NMFS to meet its 
responsibilities under NEPA for the issuance of the 5-year regulations 
and LOAs (as warranted) for mission activities in the NSWC PCD study 
area. If the Navy's FEIS is not adequate, NMFS would supplement the 
existing analysis and documents to ensure that we comply with NEPA 
prior to the issuance of the final rule and LOA.

Preliminary Determination

    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 mission activities 
utilizing HFAS/MFAS and underwater explosives in the NSWC PCD study 
area will have a negligible impact on the affected marine mammal 
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 such taking.

Classification

    This action does not contain a collection of information 
requirement for purposes of the Paperwork Reduction Act.
    This proposed rule has been determined by the Office of Management 
and Budget to be not significant for purposes of Executive Order 12866.
    Pursuant to the Regulatory Flexibility Act, the Chief Counsel for 
Regulation of the Department of Commerce has certified to the Chief 
Counsel for Advocacy of the Small Business Administration that this 
rule, if adopted, would not have a significant economic impact on a 
substantial number of small entities. The RFA requires Federal agencies 
to prepare an analysis of a rule's impact on small entities whenever 
the agency is required to publish a notice of proposed rulemaking. 
However, a Federal agency may certify, pursuant to 5 U.S.C. 605(b), 
that the action will not have a significant economic impact on a 
substantial number of small entities. The Navy is the sole entity that 
will be affected by this proposed rulemaking, not a small governmental 
jurisdiction, small organization or small business, as defined by the 
RFA. This proposed rulemaking authorizes the take of marine mammals 
incidental to a specified activity. The specified activity defined in 
the proposed rule includes the use of high-frequency and mid-frequency 
sonar and underwater detonations during training activities that are 
only conducted by the U.S. Navy. Additionally, the proposed regulations 
are specifically written for ``military readiness'' activities, as 
defined by the Marine Mammal Protection Act, as amended by the National 
Defense Authorization Act, which means that they cannot apply to small 
businesses. Additionally, any requirements imposed by a Letter of 
Authorization issued pursuant to these regulations, and any monitoring 
or reporting requirements imposed by these regulations, will be 
applicable only to the Navy. 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. Accordingly, no IRFA is required 
and none has been prepared.

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: April 22, 2009.
John Oliver,
Deputy Assistant Administrator for Operations, National Marine 
Fisheries Service.
    For the reasons set forth in the preamble, 50 CFR part 218, as 
proposed to be added at 73 FR 75655, December 12, 2008, is proposed to 
be amended as follows:

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

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

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

    2. Subpart S is added to part 218 to read as follows:

Subpart S--Taking Marine Mammals Incidental to U.S. Navy Mission 
Activities in the Naval Surface Warfare Center Panama City Division 
Study Area

Sec.
218.180 Specified activity and specified geographical region.
218.181 Permissible methods of taking.
218.182 Prohibitions.
218.183 Mitigation.
218.184 Requirements for monitoring and reporting.
218.185 Applications for Letters of Authorization.
218.186 Letters of Authorization.
218.187 Renewal of Letters of Authorization and adaptive management.
218.188 Modifications to Letters of Authorization.

Subpart S--Taking Marine Mammals Incidental to U.S. Navy Mission 
Activities in the Naval Surface Warfare Center Panama City Division 
Study Area


Sec.  218.180  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 occur incidental to the activities 
described in paragraph (c) of this section.
    (b) The taking of marine mammals by the Navy is only authorized if 
it occurs within the NSWC PCD Study, which includes St. Andrew Bay 
(SAB) and military warning areas (areas within the GOM subject to 
military operations) W-151 (includes Panama City Operating Area), W-155 
(includes Pensacola Operating Area), and W-470. A detailed description 
of these specific geographic regions is listed in Figures 2-1 and 2-2 
of the Navy's application for the Letter of Authorization (LOA). The 
NSWC PCD Study Area includes a Coastal Test Area, a Very Shallow Water 
Test Area, and Target and Operational Test Fields. The NSWC PCD 
Research, Development, Test, and Evaluation (RDT&E) activities may be 
conducted anywhere within the existing military operating areas and SAB 
from the mean high water line (average high tide mark) out to 222 km 
(120 nm) offshore. The locations and environments include:

[[Page 20194]]

    (1) Test area control sites adjacent to NSWC PCD.
    (2) Wide coastal shelf 97 km (52 nm) distance offshore to 183 m 
(600 ft), including bays and harbors.
    (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) Surface operations in territorial and non-territorial waters:
    (i) Diving;
    (ii) Salvage;
    (iii) Use of robotic vehicles;
    (iv) Use of underwater unmanned vehicles; and
    (v) Mooring and burying of mines.
    (2) The use of the following high frequency active sonar (HFAS) and 
mid-frequency active sonar (MFAS) or similar sources for U.S. Navy 
mission activities in territorial waters in the amounts indicated 
below:
    (i) AN/SQS-53/56 Kingfisher--up to 15 hours over the course of 5 
years (an average of 3 hours per year);
    (ii) Sub-bottom profiler (2-9 kHz)--up to 105 hours over the course 
of 5 years (an average of 21 hours per year);
    (iii) REMUS SAS-LF (center frequency 15 kHz)--up to 60 hours over 
the course of 5 years (an average of 12 hours per year);
    (iv) REMUS Modem--up to 125 hours over the course of 5 years (an 
average of 25 hours per year);
    (v) Sub-bottom profiler (2-16 kHz)--up to 120 hours over the course 
of 5 years (an average of 24 hours per year);
    (vi) AN/SQQ-32--up to 150 hours over the course of 5 years (an 
average of 30 hours per year);
    (vii) REMUS-SAS-LF (center frequency 20 kHz)--up to 100 hours over 
the course of 5 years (an average of 20 hours per year);
    (viii) SAS-LF--up to 175 hours over the course of 5 years (an 
average of 35 hours per year);
    (ix) AN/WLD-1 RMS-ACL--up to 168 hours over the course of 5 years 
(an average of 33.5 hours per year);
    (x) BPAUV Sidescan (center frequency 75 kHz)--up to 125 hours over 
the course of 5 years (an average of 25 hours per year);
    (xi) TVSS--up to 75 hours over the course of 5 years (an average of 
15 hours per year);
    (xii) F84Y--up to 75 hours over the course of 5 years (an average 
of 15 hours per year);
    (xiii) BPAUV Sidescan (center frequency 102.5 kHz)--up to 125 hours 
over the course of 5 years (an average of 25 hours per year);
    (xiv) REMUS-SAS-HF--up to 50 hours over the course of 5 years (an 
average of 10 hours per year);
    (xv) SAS-HF--up to 58 hours over the course of 5 years (an average 
of 11.5 hours per year);
    (xvi) AN/SQS-20--up to 2,725 hours over the course of 5 years (an 
average of 545 hours per year);
    (xvii) AN/WLD-11 RMS Navigation--up to 75 hours over the course of 
5 years (an average of 15 hours per year); and
    (xviii) BPAUV Sidescan (center frequency 120 kHz)--up to 150 hours 
over the course of 5 years (an average of 30 hours per year).
    (3) The use of the following high frequency active sonar (HFAS) and 
mid-frequency active sonar (MFAS) or similar sources for U.S. Navy 
mission activities in non-territorial waters in the amounts indicated 
below:
    (i) AN/SQS-53/56 Kingfisher--up to 5 hours over the course of 5 
years (an average of 1 hour per year);
    (ii) Sub-bottom profiler (2-9 kHz)--up to 5 hours over the course 
of 5 years (an average of 1 hour per year);
    (iii) REMUS Modem--up to 60 hours over the course of 5 years (an 
average of 12 hours per year);
    (iv) Sub-bottom profiler (2-16 kHz)--up to 5 hours over the course 
of 5 years (an average of 1 hour per year);
    (v) AN/SQQ-32--up to 5 hours over the course of 5 years (an average 
of 1 hour per year);
    (vi) SAS-LF--up to 75 hours over the course of 5 years (an average 
of 15 hours per year);
    (vii) AN/WLD-1 RMS-ACL--up to 25 hours over the course of 5 years 
(an average of 5 hours per year);
    (viii) BPAUV Sidescan (center frequency 75 kHz)--up to 190 hours 
over the course of 5 years (an average of 38 hours per year);
    (ix) TVSS--up to 83 hours over the course of 5 years (an average of 
16.5 hours per year);
    (x) F84Y--up to 75 hours over the course of 5 years (an average of 
15 hours per year);
    (xi) REMUS-SAS-HF--up to 125 hours over the course of 5 years (an 
average of 25 hours per year);
    (xii) SAS-HF--up to 75 hours over the course of 5 years (an average 
of 15 hours per year);
    (xiii) AN/AQS-20--up to 75 hours over the course of 5 years (an 
average of 15 hours per year); and
    (xiv) BPAUV Sidescan (center frequency 120 kHz)--up to 125 hours 
over the course of 5 years (an average of 25 hours per year).
    (4) Ordnance operations for U.S. Navy mission activities in 
territorial waters in the amounts indicated below:
    (i) Range 1 (0-10 lbs.)--up to 255 detonations over the course of 5 
years (an average of 51 detonations per year);
    (ii) Range 2 (11-75 lbs.)--up to 15 detonations over the course of 
5 years (an average of 3 detonations per year); and
    (iii) Line charges--up to 15 detonations over the course of 5 years 
(an average of 3 detonations per year).
    (5) Ordnance operations for U.S. Navy mission activities in non-
territorial waters in the amounts indicated below:
    (i) Range 3 (76-600 lbs.)--up to 80 detonations over the course of 
5 years (an average of 16 detonations per year).
    (ii) Reserved.
    (6) Projectile firing operations for U.S. Navy mission activities 
in non-territorial waters in the amounts indicated below:
    (i) 5 in. Naval gunfire--up to 300 rounds over the course of 5 
years (an average of 60 rounds per year);
    (ii) 40 mm rounds--up to 2,400 rounds over the course of 5 years 
(an average of 480 rounds per year);
    (iii) 30 mm rounds--up to 3,000 rounds over the course of 5 years 
(an average of 600 rounds per year);
    (iv) 20 mm rounds--up to 14,835 rounds over the course of 5 years 
(an average of 2,967 rounds per year);
    (v) 76 mm rounds--up to 1,200 rounds over the course of 5 years (an 
average of 240 rounds per year);
    (vi) 25 mm rounds--up to 2,625 rounds over the course of 5 years 
(an average of 525 rounds per year); and
    (vii) Small arms--up to 30,000 rounds over the course of 5 years 
(an average of 6,000 rounds per year).


Sec.  218.181  Permissible methods of taking.

    (a) Under Letters of Authorization issued pursuant to Sec. Sec.  
216.106 and 218.186 of this chapter, the Holder of the Letter of 
Authorization may incidentally, but not intentionally, take marine 
mammals within the area described in Sec.  218.180(b), provided the 
activity is in compliance with all terms, conditions, and requirements 
of these regulations and the appropriate Letter of Authorization.
    (b) The incidental take of marine mammals under the activities 
identified in Sec.  218.180(c) is limited to the following species, by 
the indicated method of take and the indicated number of times:
    (1) Level B Harassment:
    (i) Sperm whale (Physeter macrocephalus)--10 (an average of 2 
annually),
    (ii) Risso's dolphin (Grampus griseus)--10 (an average of 2 
annually);
    (iii) Bottlenose dolphin (Tursiops truncatus)--3,070 (an average of 
614 annually);
    (iv) Atlantic spotted dolphin (Stenella frontalis)--2,355 (an 
average of 471 annually);

[[Page 20195]]

    (v) Pantropical spotted dolphin (S. attenuata)--115 (an average of 
23 annually);
    (vi) Striped dolphin (S. coeruleoalba)--25 (an average of 5 
annually);
    (vii) Spinner dolphin (S. longirostris)--115 (an average of 23 
annually);
    (viii) Melon-headed whale (Peponocephala electra)--10 (an average 
of 2 annually);
    (ix) Short-finned pilot whale (Globicephala macrorhynchus)--5 (an 
average of 1 annually);
    (x) Clymene dolphin (S. clymene)--25 (an average of 5 annually);
    (2) Level A Harassment:
    (i) Bottlenose dolphin (Tursiops truncatus)--10 (an average of 2 
annually);
    (ii) Atlantic spotted dolphin (Stenella frontalis)--10 (an average 
of 2 annually);
    (iii) Pantropical spotted dolphin (S. attenuata)--5 (an average of 
1 annually);
    (ix) Spinner dolphin (Stenella longirostris)--5 (an average of 1 
annually).


Sec.  218.182  Prohibitions.

    Notwithstanding takings contemplated in Sec.  218.181 and 
authorized by a Letter of Authorization issued under Sec.  216.106 of 
this chapter and Sec.  218.186, no person in connection with the 
activities described in Sec.  218.180 may:
    (a) Take any marine mammal not specified in Sec.  218.181(b);
    (b) Take any marine mammal specified in Sec.  218.181(b) other than 
by incidental take as specified in Sec.  218.181(b)(1) and (2);
    (c) Take a marine mammal specified in Sec.  218.181(b) if such 
taking results in more than a negligible impact on the species or 
stocks of such marine mammal; or
    (d) Violate, or fail to comply with, the terms, conditions, and 
requirements of these regulations or a Letter of Authorization issued 
under Sec.  216.106 of this chapter and Sec.  218.186.


Sec.  218.183  Mitigation.

    (a) When conducting RDT&E activities identified in Sec.  
218.180(c), the mitigation measures contained in this subpart and 
subsequent Letters of Authorization issued under Sec. Sec.  216.106 and 
218.186 of this chapter must be implemented. These mitigation measures 
include, but are not limited to:

(1) Mitigation Measures for HFAS/MFAS Operations

    (i) Personnel Training;
    (A) All marine observers onboard platforms involved in NSWC PCD 
RDT&E activities shall review the NMFS-approved Marine Species 
Awareness Training (MSAT) material prior to use of HFAS/MFAS.
    (B) Marine observers shall be trained in the most effective means 
to ensure quick and effective communication within the command 
structure in order to facilitate implementation of mitigation measures 
if marine species are spotted.
    (ii) Marine Observer and Watchstander Responsibilities;
    (A) On the bridge of surface vessels, there shall always be at 
least one to three marine species awareness trained observer(s) on 
watch whose duties include observing the water surface around the 
vessel.
    (1) For vessels with length under 65 ft (20 m), there shall always 
be at least one marine observer on watch.
    (2) For vessels with length between 65-200 ft (20-61 m), there 
shall always be at least two marine observers on watch.
    (3) For vessels with length above 200 ft (61 m), there shall always 
be at least three marine observers on watch.
    (B) Each marine observer shall have at their disposal at least one 
set of binoculars available to aid in the detection of marine mammals.
    (C) On surface vessels equipped with AN/SQQ-53C/56, pedestal 
mounted ``Big Eye'' (20 x 110) binoculars shall be present and in good 
working order to assist in the detection of marine mammals in the 
vicinity of the vessel.
    (D) Marine observer shall employ visual search procedures employing 
a scanning methodology in accordance with the Lookout Training Handbook 
(NAVEDTRA 12968-D).
    (E) Marine observers shall scan the water from the vessel to the 
horizon and be responsible for all contacts in their sector follow the 
below protocols:
    (1) In searching the assigned sector, the marine observer shall 
always start at the forward part of the sector and search aft (toward 
the back).
    (2) To search and scan, the marine observer shall hold the 
binoculars steady so the horizon is in the top third of the field of 
vision and direct the eyes just below the horizon.
    (3) The marine observer shall scan for approximately five seconds 
in as many small steps as possible across the field seen through the 
binoculars.
    (4) The marine observers shall search the entire sector in 
approximately five-degree steps, pausing between steps for 
approximately five seconds to scan the field of view.
    (5) At the end of the sector search, the glasses would be lowered 
to allow the eyes to rest for a few seconds, and then the marine 
observer shall search back across the sector with the naked eye.
    (F) After sunset and prior to sunrise, marine observers shall 
employ Night Lookout Techniques in accordance with the Lookout Training 
Handbook.
    (G) At night, marine observers shall scan the horizon in a series 
of movements that would allow their eyes to come to periodic rests as 
they scan the sector. When visually searching at night, marine 
observers shall look a little to one side and out of the corners of 
their eyes, paying attention to the things on the outer edges of their 
field of vision.
    (H) Marine observers shall be responsible for reporting all objects 
or anomalies sighted in the water (regardless of the distance from the 
vessel) to the Test Director or the Test Director's designee.
    (iii) Operating Procedures;
    (A) A Record of Environmental Consideration shall be included in 
the Test Plan prior to the test event to further disseminate the 
personnel testing requirement and general marine mammal mitigation 
measures.
    (B) Test Directors shall make use of marine species detection cues 
and information to limit interaction with marine species to the maximum 
extent possible consistent with safety of the vessel.
    (C) All personnel engaged in passive acoustic sonar operation 
(including aircraft or surface vessels) shall monitor for marine mammal 
vocalizations and report the detection of any marine mammal to the Test 
Director or the Test Director's designee for dissemination and 
appropriate action.
    (D) During HFAS/MFAS mission activities, personnel shall utilize 
all available sensor and optical systems (such as Night Vision Goggles) 
to aid in the detection of marine mammals.
    (E) Navy aircraft participating in exercises at sea shall conduct 
and maintain surveillance for marine species of concern as long as it 
does not violate safety constraints or interfere with the 
accomplishment of primary operational duties.
    (F) Aircraft with deployed sonobuoys shall use only the passive 
capability of sonobuoys when marine mammals are detected within 200 
yards of the sonobuoy.
    (G) Marine mammal detections shall be immediately reported to 
assigned Aircraft Control Unit for further dissemination to vessels in 
the vicinity of the marine species as appropriate where it is 
reasonable to conclude that the course of the vessel will likely result 
in a closing of the distance to the detected marine mammal.

[[Page 20196]]

    (H) Safety Zones--When marine mammals are detected by any means 
(aircraft, shipboard marine observer, or acoustically) the Navy will 
ensure that HFAS/MFAS transmission levels are limited to at least 6 dB 
below normal operating levels if any detected marine mammals are within 
1,000 yards (914 m) of the sonar dome (the bow).
    (1) Vessels shall continue to limit maximum HFAS/MFAS transmission 
levels by this 6-dB factor until the marine mammal has been seen to 
leave the area, has not been detected for 30 minutes, or the vessel has 
transited more than 2,000 yards (1,828 m) beyond the location of the 
last detection.
    (2) The Navy shall ensure that HFAS/MFAS transmissions will be 
limited to at least 10 dB below the equipment's normal operating level 
if any detected animals are within 500 yards (457 m) of the sonar dome. 
Vessels will continue to limit maximum ping levels by this 10-dB factor 
until the marine mammal has been seen to leave the area, has not been 
detected for 30 minutes, or the vessel has transited more than 2,000 
yards (1,828 m) beyond the location of the last detection.
    (3) The Navy shall ensure that HFAS/MFAS transmissions are ceased 
if any detected marine mammals are within 200 yards (183 m) of the 
sonar dome. HFAS/MFAS will not resume until the marine mammal has been 
seen to leave the area, has not been detected for 30 minutes, or the 
vessel has transited more than 2,000 yards (1,828 m) beyond the 
location of the last detection.
    (4) Special conditions applicable for dolphins and porpoises only: 
If, after conducting an initial maneuver to avoid close quarters with 
dolphins or porpoises, the Officer of the Deck concludes that dolphins 
or porpoises are deliberately closing to ride the vessel's bow wave, no 
further mitigation actions are necessary while the dolphins or 
porpoises continue to exhibit bow wave riding behavior.
    (5) If the need for power-down should arise as detailed in ``Safety 
Zones'' above, Navy shall follow the requirements as though they were 
operating at 235 dB--the normal operating level (i.e., the first power-
down will be to 229 dB, regardless of at what level above 235 sonar was 
being operated).
    (I) Prior to start up or restart of active sonar, operators will 
check that the Safety Zone radius around the sound source is clear of 
marine mammals.
    (J) Sonar levels (generally)--Navy shall operate sonar at the 
lowest practicable level, not to exceed 235 dB, except as required to 
meet RDT&E objectives.
    (K) Helicopters shall observe/survey the vicinity of mission 
activities for 10 minutes before the first deployment of active 
(dipping) sonar in the water.
    (L) Helicopters shall not dip their sonar within 200 yards (183 m) 
of a marine mammal and shall cease pinging if a marine mammal closes 
within 200 yards (183 m) after pinging has begun.
    (M) Submarine sonar operators shall review detection indicators of 
close-aboard marine mammals prior to the commencement of mission 
activities involving active mid-frequency and high frequency sonar.

(2) Proposed Mitigation Measures for Ordnance and Projectile Firing

    (i) No detonations over 34 kg (75 lb) shall be conducted in 
territorial waters, except the line charge detonation, which is a 107 m 
(350 ft).
    (ii) The number of live mine detonations shall be minimized and the 
smallest amount of explosive material possible to achieve test 
objectives will be used.
    (iii) Activities shall be coordinated through the Environmental 
Help Desk to allow potential concentrations of detonations in a 
particular area over a short time to be identified and avoided.
    (iv) Visual surveys and aerial surveys of the clearance zones 
specified in Sec.  218.183(2)(vi)(A)-(C)shall be conducted in 
accordance with Sec.  218.184(e) for all test operations that involve 
detonation events with large net explosive weight (NEW). Any protected 
species sighted will be reported.
    (v) Line charge tests shall not be conducted during the nighttime.
    (vi) Additional mitigation measures shall be determined through the 
NSWC PCD's Environmental Review Process based on test activities 
including the size of detonations, test platforms, and environmental 
effects documented in the Navy's EIS/OEIS. Clearance zones must be 
determined based on the upper limit of different ranges of net 
explosive weight (NEW) used in the tests, as listed below:
    (A) NEW between 76-600 lb: clearance zone is 2,863 m;
    (B) NEW between 11-75 lb: clearance zone is 997 m; and
    (C) NEW under 11 lb: clearance zone is 345 m.

(3) Proposed Mitigation Measures for Surface Operations and Other 
Activities:

    (i) While underway, vessels shall have at least one to three marine 
species awareness trained observers (based on vessel length) with 
binoculars. As part of their regular duties, marine observers shall 
watch for and report to the Test Director or Test Director's designee 
the presence of marine mammals.
    (A) For vessels with length under 65 ft (20 m), there shall always 
be at least one marine observer on watch.
    (B) For vessels with length between 65-200 ft (20-61 m), there 
shall always be at least two marine observers on watch.
    (C) For vessels with length above 200 ft (61 m), there shall always 
be at least three marine observers on watch.
    (ii) Marine observers shall employ visual search procedures 
employing a scanning method in accordance with the Lookout Training 
Handbook (NAVEDTRA 12968-D).
    (iii) While in transit, naval vessels shall be alert at all times, 
use extreme caution, and proceed at a ``safe speed'' (the minimum speed 
at which mission goals or safety will not be compromised) so that the 
vessel can take proper and effective action to avoid a collision with 
any marine animal and can be stopped within a distance appropriate to 
the prevailing circumstances and conditions.
    (iv) When marine mammals have been sighted in the area, Navy 
vessels shall increase vigilance and shall implement measures to avoid 
collisions with marine mammals and avoid activities that might result 
in close interaction of naval assets and marine mammals. Actions shall 
include changing speed and/or direction and are dictated by 
environmental and other conditions (e.g., safety, weather).
    (v) Naval vessels shall maneuver to keep at least 500 yd (460 m) 
away from any observed whale and avoid approaching whales head-on. This 
requirement does 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. Vessels shall take reasonable steps to 
alert other vessels in the vicinity of the whale.
    (vi) Where feasible and consistent with mission and safety, vessels 
shall avoid closing to within 200 yards (183 m) of marine mammals other 
than whales.
    (vii) All vessels shall maintain logs and records documenting RDT&E 
activities should they be required for event reconstruction purposes. 
Logs and records shall be kept for a period of 30 days following 
completion of a RDT&E mission activity.
    (b) [Reserved]

[[Page 20197]]

Sec.  218.184  Requirements for monitoring and reporting.

    (a) The Holder of the Letter of Authorization issued pursuant to 
Sec. Sec.  216.106 and 218.186 for activities described in Sec.  
218.180(c) is required to cooperate with the NMFS when monitoring the 
impacts of the activity on marine mammals.
    (b) The Holder of the Authorization must notify NMFS immediately 
(or as soon as clearance procedures allow) if the specified activity 
identified in Sec.  218.180(c) is thought to have resulted in the 
mortality or injury of any marine mammals, or in any take of marine 
mammals not identified or authorized in Sec.  218.181(b).
    (c) The Holder of the Letter of Authorization must conduct all 
monitoring and/or research required under the Letter of Authorization.
    (d) The Navy shall complete an Integrated Comprehensive Monitoring 
Program (ICMP) Plan in 2009. This planning and adaptive management tool 
shall include:
    (1) A method for prioritizing monitoring projects that clearly 
describes the characteristics of a proposal that factor into its 
priority.
    (2) A method for annually reviewing, with NMFS, monitoring results, 
Navy R&D, and current science to use for potential modification of 
mitigation or monitoring methods.
    (3) A detailed description of the Monitoring Workshop to be 
convened in 2011 and how and when Navy/NMFS will subsequently utilize 
the findings of the Monitoring Workshop to potentially modify 
subsequent monitoring and mitigation.
    (4) An adaptive management plan.
    (5) A method for standardizing data collection for the NSWC PCD 
Study Area and across other locations.
    (e) The Holder of the Letter of Authorization shall, when 
conducting training events in the NSWC PCD Study Area, implement the 
following monitoring methods:
    (1) Visual Surveys--Vessel, Aerial and Shore-based
    (i) In accordance with all safety considerations, observations 
shall be maximized by working from all available platforms: vessels, 
aircraft, land and/or in combination.
    (ii) Vessel and aerial surveys shall be conducted two days before, 
during, and one to five days after the NSWC PCD mission activities on 
commercial vessels and aircraft.
    (iii) Visual surveys shall be conducted during Navy mission 
activities that have been identified to provide the highest likelihood 
of success.
    (iv) The visual survey team shall collect the same data that are 
collected by Navy marine observers, including but not limited to:
    (A) Location of sighting;
    (B) Species (or to the lowest taxa possible);
    (C) Number of individuals;
    (D) Number of calves present, if any;
    (E) Duration of sighting;
    (F) Behavior of marine animals sighted;
    (G) Direction of travel;
    (H) Environmental information associated with sighting event 
including Beaufort sea state, wave height, swell direction, wind 
direction, wind speed, glare, percentage of glare, percentage of cloud 
cover; and
    (I) When in relation to Navy exercises did the sighting occur 
(before, during or after detonations/exercise).
    (v) Animal sightings and relative distance from a particular 
activity site shall be used post survey to estimate the number of 
marine mammals exposed to different received levels (energy and 
pressure of discharge based on distance to the source, bathymetry, 
oceanographic conditions and the type and size of detonation) and their 
corresponding behavior.
    (vi) Any digital photographs that are taken of marine mammals 
during visual surveys shall be provided to local researchers for their 
regional research.
    (A) Aerial surveys:
    (1) During NSWC PCD mission activities, an aerial survey team shall 
fly transects relative to a Navy surface vessel that is conducting the 
mission activities.
    (2) The aerial survey team shall collect both visual sightings and 
behavioral observations of marine animals.
    (3) These transect data shall provide an opportunity to collect 
data of marine mammals at different received levels and their 
behavioral responses and movement relative to the Navy vessel's 
position.
    (4) Aerial surveys shall include time with and without test events 
in order to compare density, geographical distribution and behavioral 
observations.
    (5) Behavioral observation methods shall involve three 
professionally trained marine mammal observers and a pilot. Two 
observers shall observe behaviors, one with hand-held binoculars and 
one with the naked eye.
    (6) Detailed behavioral focal observations of cetaceans shall be 
recorded including the following variables where possible: species (or 
to the lowest taxa possible), group size and composition (number of 
calves, etc.), latitude/longitude, surface and dive durations and 
times, number and spacing/times of respirations, conspicuous behaviors 
(e.g., breach, tail slap, etc.), behavioral states, orientation and 
changes in orientation, estimated group travel speed, inter-individual 
distances, defecation, social interactions, aircraft speed, aircraft 
altitude, distance to focal group (using the plane's radar) and any 
unusual behaviors or apparent reactions.
    (B) Vessel Surveys:
    (1) Vessel surveys shall be designed to maximize detections of any 
target species near mission activity event for focal follows.
    (2) Systematic transects shall be used to locate marine mammals. In 
the course of conducting these surveys, the vessel(s) shall deviate 
from transect protocol to collect behavioral data particularly if a 
Navy vessel is visible on the horizon or closer.
    (3) While the Navy vessels are within view, attempts shall be made 
to position the dedicated survey vessel in the best possible way to 
obtain focal follow data in the presence of the Navy mission 
activities. If Navy vessels are not in view, then the vessel shall 
begin a systematic line transect surveys within the area to assess 
marine mammal occurrence and observe behavior.
    (4) Post-analysis shall focus on how the location, speed and vector 
of the survey vessel and the location and direction of the sonar source 
(e.g., Navy surface vessel) relates to the animal.
    (5) Any other vessels or aircraft observed in the area shall also 
be documented.
    (C) Shore-based Surveys:
    (1) Shore-based monitors shall observe explosive events that are 
planned in advance to occur adjacent to nearshore areas where there are 
elevated coastal structures (e.g., lookout tower at Eglin Air Force 
Base) or topography, and shall use binoculars or theodolite to augment 
other visual survey methods.
    (2) Shore-based surveys of the detonation area and nearby beaches 
shall be conducted for stranded marine animals following nearshore 
events. If any distressed, injured or stranded animals are observed, an 
assessment of the animal's condition (alive, injured, dead, or degree 
of decomposition) shall be reported immediately to the Navy for 
appropriate action and the information shall be transmitted immediately 
to NMFS.
    (3) If animals are observed prior to or during an explosion, a 
focal follow of that individual or group shall be conducted to record 
behavioral responses.

[[Page 20198]]

    (2) Passive Acoustic Monitoring (PAM):
    (i) The Navy shall deploy a stationary, bottom-set hydrophone array 
in the NSWC PCD Study Area for PAM.
    (ii) The array shall be deployed for each of the days the ship is 
at sea.
    (iii) The array shall be able to detect low frequency vocalizations 
(less than 1,000 Hz) for baleen whales and relatively high frequency 
vocalizations (up to 30 kHz) for odontocetes.
    (iv) These buoys shall be left in place for a long enough duration 
(e.g., months) that data are collected before, during and outside of 
mission activities.
    (v) Acoustic data collected from the buoys shall be used in order 
to detect, locate, and potentially track calling whales/dolphins.
    (3) Marine Mammal Observers on Navy vessels:
    (i) Civilian Marine Mammal Observers (MMOs) aboard Navy vessels 
shall be used to research the effectiveness of Navy lookouts, as well 
as for data collection during other monitoring surveys.
    (ii) MMOs shall be field-experienced observers that are Navy 
biologists or contracted observers.
    (iii) MMOs shall be placed alongside existing Navy marine observers 
during a sub-set of RDT&E events.
    (iv) MMOs shall inform the Navy marine observer of any marine 
mammal sighting so that appropriate action may be taken by the chain of 
command. For less biased data, it is recommended that MMOs schedule 
their daily observations to duplicate the marine observers' schedule.
    (v) MMOs shall monitor for marine mammals from the same height 
above water as the lookouts (e.g. bridge wings) and as all visual 
survey teams, and they shall collect the same data collected by Navy 
marine observers, including but not limited to:
    (A) Location of sighting;
    (B) Species;
    (C) Number of individuals;
    (D) Number of calves present, if any;
    (E) Duration of sighting;
    (F) Behavior of marine animals sighted;
    (G) Direction of travel;
    (H) Environmental information associated with sighting event 
including Beaufort sea state, wave height, swell direction, wind 
direction, wind speed, glare, percentage of glare, percentage of cloud 
cover; and
    (I) When in relation to Navy exercises did the sighting occur 
(before, during or after detonations/exercise).
    (f) Monitoring Report--The Navy shall submit a report annually on 
September 1 describing the implementation and results (through June 1 
of the same year) of the monitoring required in Sec.  218.184(e).
    (g) NSWC PCD Comprehensive Report--The Navy shall submit to NMFS a 
draft report that analyzes and summarizes all of the multi-year marine 
mammal information gathered during sonar and explosive exercises for 
which individual reports are required in Sec.  218.184 (d-f). This 
report will be submitted at the end of the fourth year of the rule 
(November 2012), covering activities that have occurred through June 1, 
2012.
    (h) The Navy shall respond to NMFS comments on the draft 
comprehensive report if submitted within 3 months of receipt. The 
report will be considered final after the Navy has addressed NMFS' 
comments, or three months after the submittal of the draft if NMFS does 
not comment by then.
    (i) In 2011, the Navy shall convene a Monitoring Workshop in which 
the Monitoring Workshop participants will be asked to review the Navy's 
Monitoring Plans and monitoring results and make individual 
recommendations (to the Navy and NMFS) of ways of improving the 
Monitoring Plans. The recommendations shall be reviewed by the Navy, in 
consultation with NMFS, and modifications to the Monitoring Plan shall 
be made, as appropriate.


Sec.  218.185  Applications for Letters of Authorization.

    To incidentally take marine mammals pursuant to these regulations, 
the U.S. citizen (as defined by Sec.  216.103 of this chapter) 
conducting the activity identified in Sec.  218.180(c) (the U.S. Navy) 
must apply for and obtain either an initial Letter of Authorization in 
accordance with Sec.  218.186 or a renewal under Sec.  218.187.


Sec.  218.186  Letters of Authorization.

    (a) A Letter of Authorization, unless suspended or revoked, will be 
valid for a period of time not to exceed the period of validity of this 
subpart, but must be renewed annually subject to annual renewal 
conditions in Sec.  218.187.
    (b) Each Letter of Authorization will set forth:
    (1) Permissible methods of incidental taking;
    (2) Means of effecting the least practicable adverse impact on the 
species, its habitat, and on the availability of the species for 
subsistence uses (i.e., mitigation); and
    (3) Requirements for mitigation, monitoring and reporting.
    (c) Issuance and renewal of the Letter of Authorization 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.  218.187  Renewal of Letters of Authorization and adaptive 
management.

    (a) A Letter of Authorization issued under Sec.  216.106 and Sec.  
218.186 for the activity identified in Sec.  218.180(c) will be renewed 
annually upon:
    (1) Notification to NMFS that the activity described in the 
application submitted under Sec.  218.185 shall be undertaken and that 
there will not be a substantial modification to the described work, 
mitigation or monitoring undertaken during the upcoming 12 months;
    (2) Timely receipt of the monitoring reports required under Sec.  
218.184(b); and
    (3) A determination by the NMFS that the mitigation, monitoring and 
reporting measures required under Sec.  218.183 and the Letter of 
Authorization issued under Sec. Sec.  216.106 and 218.186, were 
undertaken and will be undertaken during the upcoming annual period of 
validity of a renewed Letter of Authorization.
    (b) If a request for a renewal of a Letter of Authorization issued 
under Sec. Sec.  216.106 and 218.187 indicates that a substantial 
modification to the described work, mitigation or monitoring undertaken 
during the upcoming season will occur, the NMFS will provide the public 
a period of 30 days for review and comment on the request. Review and 
comment on renewals of Letters of Authorization are restricted to:
    (1) New cited information and data indicating that the 
determinations made in this document are in need of reconsideration, 
and
    (2) Proposed changes to the mitigation and monitoring requirements 
contained in these regulations or in the current Letter of 
Authorization.
    (c) A notice of issuance or denial of a renewal of a Letter of 
Authorization will be published in the Federal Register.
    (d) NMFS, in response to new information and in consultation with 
the Navy, may modify the mitigation or monitoring measures in 
subsequent LOAs if doing so creates a reasonable likelihood of more 
effectively accomplishing the goals of mitigation and monitoring set 
forth in the preamble of these regulations. Below are some of the 
possible sources of new data that could contribute to the decision to 
modify the mitigation or monitoring measures:
    (1) Results from the Navy's monitoring from the previous year

[[Page 20199]]

(either from NSWC PCD Study Area or other locations).
    (2) Findings of the Monitoring Workshop that the Navy will convene 
in 2011 (Sec.  218.184(i)).
    (3) Compiled results of Navy funded research and development (R&D) 
studies (presented pursuant to the ICMP (Sec.  218.184(d)).
    (4) Results from specific stranding investigations (either from the 
NSWC PCD Study Area or other locations).
    (5) Results from the Long Term Prospective Study described in the 
preamble to these regulations.
    (6) Results from general marine mammal and sound research (funded 
by the Navy (described below) or otherwise).
    (7) Any information which reveals that marine mammals may have been 
taken in a manner, extent or number not authorized by these regulations 
or subsequent Letters of Authorization.


Sec.  218.188  Modifications to Letters of Authorization.

    (a) Except as provided in paragraph (b) of this section, no 
substantive modification (including withdrawal or suspension) to the 
Letter of Authorization by NMFS, issued pursuant to Sec.  216.106 of 
this chapter and Sec.  218.186 and subject to the provisions of this 
subpart shall be made until after notification and an opportunity for 
public comment has been provided. For purposes of this paragraph, a 
renewal of a Letter of Authorization under Sec.  218.187, without 
modification (except for the period of validity), is not considered a 
substantive modification.
    (b) If the Assistant Administrator determines that an emergency 
exists that poses a significant risk to the well-being of the species 
or stocks of marine mammals specified in Sec.  218.181(b), a Letter of 
Authorization issued pursuant to Sec.  216.106 of this chapter and 
Sec.  218.186 may be substantively modified without prior notification 
and an opportunity for public comment. Notification will be published 
in the Federal Register within 30 days subsequent to the action.

[FR Doc. E9-9645 Filed 4-29-09; 8:45 am]
BILLING CODE 3510-22-P