[Federal Register Volume 74, Number 128 (Tuesday, July 7, 2009)]
[Proposed Rules]
[Pages 32264-32305]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-15839]
[[Page 32263]]
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Part III
Department of Commerce
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National Oceanic and Atmospheric Administration
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50 CFR Part 218
Taking and Importing Marine Mammals; U.S. Navy's Research, Development,
Test, and Evaluation Activities Within the Naval Sea Systems Command
Naval Undersea Warfare Center Keyport Range Complex; Proposed Rule
Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 /
Proposed Rules
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 218
RIN 0648-AX11
Taking and Importing Marine Mammals; U.S. Navy's Research,
Development, Test, and Evaluation Activities Within the Naval Sea
Systems Command Naval Undersea Warfare Center Keyport Range Complex
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 the Navy's Research,
Development, Test, and Evaluation (RDT&E) activities within the Naval
Sea System Command (NAVSEA) Naval Undersea Warfare Center (NUWC)
Keyport Range Complex and the associated proposed extensions for the
period of September 2009 through September 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 August
6, 2009.
ADDRESSES: You may submit comments, identified by 0648-AX11, 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 Keyport Range
Complex RDT&E and range extension activities was published on September
12, 2008, and may be viewed at http://www-keyport.kpt.nuwc.navy.mil.
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 in sections 101(a)(5)(A) and (D) 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 May 15, 2008, NMFS received an application from the Navy
requesting authorization for the take of 5 species of marine mammals
incidental to the RDT&E activities within the NAVSEA NUWC Keyport Range
Complex Extension over the course of 5 years. These RDT&E activities
are classified as military readiness activities. On April 29, 2009,
NMFS received additional information and clarification on the Navy's
proposed NAVSEA NUWC Keyport Range Complex Extension RDT&E activities.
The Navy states that these RDT&E activities may cause various impacts
to marine mammal species in the proposed action area. The Navy requests
an authorization to take individuals of these marine mammals by Level B
Harassment. Please refer to Tables 6-23, 6-24, 6-25, and 6-26 of the
Navy's Letter of Authorization (LOA) application for detailed
information of the potential marine mammal exposures from the RDT&E
activities in the Keyport Range Complex Extension per year. However,
due to the proposed mitigation and monitoring measures and standard
range operating procedures in place, NMFS estimates that the take of
marine mammals is likely to be lower than the amount requested. NMFS
does not expect any marine mammals to be killed or injured as a result
of the Navy's proposed activities, and NMFS is not proposing to
authorize any injury or mortality incidental to the Navy's proposed
RDT&E activities within the Keyport Range Complex Extension.
Background of Navy Request
The Navy proposes to extend the NAVSEA NUWC Keyport Range Complex
in Washington State. The NAVSEA NUWC Keyport Range Complex has the
infrastructure to support RDT&E activities. Centrally located within
Washington State, the
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NAVSEA NUWC Keyport Range Complex has extensive existing range assets
and capabilities. The NAVSEA NUWC Keyport Range Complex is composed of
Keyport Range Site, Dabob Bay Range Complex (DBRC) Site, and Quinault
Underwater Tracking Range (QUTR) Site (see Figure 1-1 of the Navy's LOA
application).
The goal of the Proposed Action is to extend the operational areas
of each range site. Extending the Range Complex operating areas outside
existing range boundaries will allow the Navy to support existing and
future range activities including evolving manned and unmanned vehicle
program needs in multiple marine environments. With the proposed
extension of the Keyport and QUTR range sites, the range sites could
support more activities, which include increases in the numbers of
tests and days of testing. No additional operational tempo is proposed
for the DBRC Site. Existing and evolving range activities applied for
in this LOA application include RDT&E and training of system
capabilities such as guidance, control, and sensor accuracy of manned
and unmanned vehicles in multiple marine environments (e.g., differing
depths, salinity levels, temperatures, sea states, etc.).
The range extension is necessary to provide adequate testing area
and volume (i.e., surface area and water depth) in multiple marine
environments. The extension enables the NUWC Keyport to fulfill its
mission of providing test and evaluation services in both surrogate and
simulated war-fighting environments for emerging manned and unmanned
vehicle program activities. Within the NAVSEA NUWC Keyport Range
Complex Extension, the NUWC Keyport activities include testing,
training, and evaluation of systems capabilities such as guidance,
control, and sensor accuracy of manned and unmanned vehicles in
multiple marine environments (e.g., differing depths, salinity levels,
temperatures, sea states, etc.).
NUWC Keyport consists of 340 acres (138 hectares [ha]) on the
shores of Liberty Bay and Port Orchard Reach (a.k.a. Port Orchard
Narrows), and is located adjacent to the town of Keyport, due west of
Seattle. NUWC Keyport, a part of NAVSEA, is the center for integrated
undersea warfare systems dependability, integrated mine and undersea
warfare supportability, and undersea vehicle maintenance and
engineering. It provides test and evaluation, in-service engineering,
maintenance, Fleet readiness, and industrial-based support for undersea
warfare systems, including RDT&E of torpedoes, unmanned vehicles,
sensors, targets, countermeasure systems, and acoustic systems.
The NAVSEA NUWC Keyport Range Complex is divided into open ocean/
offshore areas and in shore areas:
Open Ocean Area--air, surface, and subsurface areas of the
NAVSEA NUWC Keyport Range Complex that lie outside of 12 nautical miles
(nm) from land.
Offshore Area--air, surface, and subsurface ocean areas
within 12 nm of the Pacific Coast.
Inshore--air, surface, and subsurface areas within the
Puget Sound, Port Orchard Reach, Hood Canal, and Dabob Bay.
Keyport Range Site
Located adjacent to NUWC Keyport, this range provides approximately
1.5 square nautical miles (nm\2\) (5.1 square kilometers [km\2\]) of
shallow underwater testing, including in-shore shallow water sites and
a shallow lagoon to support integrated undersea warfare systems and
vehicle maintenance and engineering activities (see Figures 1-2 and 1-3
of the Navy's LOA application). The Navy has conducted underwater
testing at the Keyport Range Site since 1914. Underwater tracking of
test activities is accomplished by using temporary or portable range
equipment. The range is currently used an average of 6 times per year
for vehicle testing and a variety of boat and diver training
activities, each lasting 1-30 days. There may be several activities in
1 day. The range site also supports: (1) Detection, classification, and
localization of test objectives and (2) magnetics measurement programs.
Explosive warheads are not placed on test units or tested within the
Keyport Range Site.
DBRC Site
Currently, the DBRC Site assets include the Dabob Bay Military
Operating Area (MOA), the Hood Canal North and South MOAs adjacent to
Submarine Base (SUBASE) Bangor, and the Connecting Waters (see Figures
1-2 and 1-4 of the Navy's LOA application). The DBRC Site is the Navy's
premier location within the U.S. for RDT&E of underwater systems such
as torpedoes, countermeasures, targets, and ship systems. Primary
activities at the DBRC Site support proofing of underwater systems,
research and development test support, and Fleet training and tactical
evaluations involving aircraft, submarines, and surface ships. Tests
and evaluations of underwater systems, from the first prototype and
pre-production stages up through Fleet activities (inception to
deployment), ensure reliability and availability of underwater systems
and their Fleet components. As with the Keyport Range Site, there are
no explosive warheads tested or placed on test units.
The DBRC Site also supports acoustic/magnetic measurement programs.
These programs include underwater vehicle/ship noise/magnetic signature
recording, radiated sound investigations, and other acoustic
evaluations. In the course of these activities, various combinations of
aircraft, submarines, and surface ships are used as launch platforms.
Test equipment may also be launched or deployed from shore off a pier
or placed in the water by hand. NUWC Keyport currently conducts
activities within four underwater testing areas in the DBRC Site. These
areas are:
Dabob Bay MOA--a deep-water range in Jefferson County
approximately 14.5 nm\2\ (49.9 km\2\) in size. The acoustic tracking
space within the range is approximately 7.3 by 1.3 nm (13.5 by 2.4 km)
(9.5 nm\2\ [32.4 km\2\]) with a maximum depth of 600 ft (183 m). The
Dabob Bay MOA is the principal range and the only component of the DBRC
Site with extensive acoustic monitoring instrumentation installed on
the seafloor, allowing for object tracking, communications, passive
sensing, and target simulation.
Hood Canal MOAs--There are two deep-water operating areas
adjacent to SUBASE Bangor in Hood Canal: Hood Canal MOA South, which is
approximately 4.5 nm\2\ (15.4 km\2\) in size, and Hood Canal MOA North,
which is approximately 7.9 nm\2\ (27.0 km\2\) in size. Both areas have
an average depth of 200 ft (61 m). The Hood Canal MOAs are used for
vessel sensor accuracy tests and launch and recovery of test systems
where tracking is optional.
Connecting Waters--the portion of the Hood Canal that
connects the Dabob Bay MOA with the Hood Canal MOAs. The shortest
distance between the Dabob Bay MOA and Hood Canal MOA South by water is
approximately 5.8 nm\2\ (19.8 km\2\). Water depth in the Connecting
Waters is typically greater than 300 ft (91 m).
QUTR Site
The Navy has conducted underwater testing at the QUTR Site since
1981 and maintains a control center at the Kalaloch Ranger Station. As
at the other range sites, no explosive warheads are used at the QUTR
Site. The QUTR Site is a rectangular-shaped test area of about 48.3
nm\2\ (165.5 km\2\), located approximately 6.5 nm (12 km) off the
Pacific Coast at Kalaloch, Washington. It
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lies within the boundaries of the Olympic Coast National Marine
Sanctuary (OCNMS).
The QUTR Site is instrumented to track surface vessels, submarines,
and various undersea vehicles. Bottom sensors are permanently mounted
on the sea floor for tracking and are maintained and configured by the
Navy. The sensors are connected to the shore via cables, which extend
under the beach to the bluffs and end at a Navy trailer in Kalaloch
(National Park Service [NPS] property). In addition, portable range
equipment may be set up prior to conducting various activities on the
range and removed after it is no longer needed. All communications are
sent back to NUWC Keyport for monitoring.
This range underlies a small portion (W-237A) of the larger
airspace unit W-237. This airspace complex comprises the northern
portion of the Pacific Northwest Ocean Surface/Subsurface Operating
Area (OPAREA), NOAA chart number 18500 (NOAA, 2006). Activities in this
airspace are scheduled and coordinated with Naval Air Station (NAS)
Whidbey Island and Commander Submarine Force, U.S. Pacific Fleet
(COMSUBPAC).
All range areas in the NAVSEA NUWC Keyport Range Complex Extension
include areas where marine mammals may be found. Range activities will
be conducted in the Keyport Site, the DBRC, and the QUTR Site. The
proposed annual usage at each site is listed in Table 1. This includes
tracking sonar systems, side-scan, and thermal propulsion systems.
Table 1--Projected Annual Days of Use by Range Site
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QUTR site--
Keyport range DBRC site QUTR site-- surf zone
site offshore
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Current......................................... 55 200 14 0
Proposed........................................ 60 200 16 30
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Description of the Specified Activities
Typical activities conducted in the NAVSEA NUWC Keyport Range
Complex Extension on the three existing range sites primarily support
undersea warfare RDT&E program requirements, but they also support
general equipment test and military personnel training needs, including
Fleet activities. These activities involve mid- and high-frequency
acoustic sources with the potential to affect marine mammals that may
be present within the NAVSEA NUWC Keyport Range Complex Extension.
Current and proposed activities within the Keyport Range Complex
Extension are listed below:
Range Activities: Testing That Involves Active Acoustic Devices
A list of the primary active acoustic sources used within the
NAVSEA NUWC Keyport Range Complex with information on the frequency
bands is shown in Table 2. In this document, low frequency is defined
as below 1 kiloHertz (kHz), mid frequency is defined as between 1 kHz
and 10 kHz, and high frequency is defined as above 10 kHz.
Table 2--Primary Acoustic Sources Commonly Used Within the NAVSEA NUWC
Keyport Range Complex
------------------------------------------------------------------------
Maximum source
Source Frequency (kHz) level (dB re 1
[mu]Pa-m)
------------------------------------------------------------------------
Sonar:
General range tracking (at 10-100 195
Keyport Range Site)..........
General range tracking (at 10-100 203
DBRC and QUTR Sites).........
UUV tracking.................. 10-100 195
Torpedoes..................... 10-100 233
Range targets and special 5-100 195
tests (at Keyport Range Site)
Range targets and special 5-100 238
tests (at DBRC and QUTR
Sites).......................
Special sonars (e.g., UUV 100-2,500 235
payload).....................
Fleet aircraft--active 2-20 225
sonobuoys and helo-dipping
sonars.......................
Side-scan..................... 100-700 235
Other Acoustic Sources:
Acoustic modems............... 10-300 210
Target simulator.............. 0.1-10 170
Aid to navigation (range 70-80 210
equipment)...................
Sub-bottom profiler........... 2-7 210
35-45 220
Engine noise (surface vessels, 0.05-10 170
submarines, torpedoes, UUVs).
------------------------------------------------------------------------
(1) General Range Tracking
General range tracking on the instrumented ranges and portable
range sites have active output in relatively wide frequency bands.
Operating frequencies are 10 to 100 kHz. At the Keyport Range Site the
sound pressure level (SPL) of the source (source level) is a maximum of
195 dB re 1 [mu]Pa-m. At the DBRC and QUTR sites, the source level for
general range tracking is a maximum of 203 dB re 1 [mu]Pa-m.
(2) UUV Tracking Systems
UUV tracking systems operate at frequencies of 10 to 100 kHz with
maximum source levels of 195 dB re 1 [mu]Pa-m at all range sites.
(3) Torpedo Sonars
Torpedo sonars are used for several purposes including detection,
classification, and location and vary in frequency from 10 to 100 kHz.
The maximum source level of a torpedo sonar is 233 dB re 1 [mu]Pa-m.
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(4) Range Targets and Special Tests
Range targets and special test systems are within the 5 to 100 kHz
frequency range at the Keyport Range Site with a maximum source level
of 195 dB re 1 [mu]Pa-m. At the DBRC and QUTR sites, the maximum source
level is 238 dB re 1 [mu]Pa-m.
(5) Special Sonars
Special sonars can be carried as a payload on a UUV, suspended from
a range craft, or set on or above the sea floor. These can vary widely
from 100 kHz to a very high frequency of 2,500 kHz for very short range
detection and classification. The maximum source level of these
acoustic sources is 235 dB re 1 [mu]Pa-m.
(6) Sonobuoys and Helicopter Dipping Sonar
Sonobuoys and helicopter dipping sonars are deployed from Fleet
aircraft and operate at frequencies of 2 to 20 kHz with maximum source
levels of 225 dB re 1 [mu]Pa-m. Dipping sonars are active or passive
devices that are lowered on cable by helicopters or surface vessels to
detect or maintain contact with underwater targets.
(7) Side Scan Sonar
Side-scan sonar is used for mapping, detection, classification, and
localization of items on the sea floor such as cabling, shipwrecks, and
mine shapes. It is high frequency typically 100 to 700 kHz using
multiple frequencies at one time with a very directional focus. The
maximum source level is 235 dB re 1 [mu]Pa-m. Side-scan and multibeam
sonar systems are towed or mounted on a test vehicle or ship.
(8) Other Acoustic Sources
Other acoustic sources may include acoustic modems, targets, aids
to navigation, subbottom profilers, and engine noise.
An acoustic modem is a communication device that transmits
an acoustically encoded signal from a source to a receiver. Acoustic
modems emit pulses from 10 to 300 kHz at source levels less than 210 dB
re 1 [mu]Pa-m.
Target simulators operate at frequencies of 100 Hertz (Hz)
(0.1 kHz) to 10 kHz at source levels of less than 170 dB re 1 [mu]Pa-m.
Aids to navigation transmit location data from ship to
shore and back to ship so the crew can have real-time detailed location
information. This is typical of the range equipment used in support of
testing. New aids to navigation can also be deployed and tested using
70 to 80 kHz at source levels less than 210 dB re 1 [mu]Pa-m.
Subbottom profilers are often commercial off-the-shelf
sonars used to determine characteristics of the sea bottom and
subbottom such as mud above bedrock or other rocky substrate. These
operate at 2 to 7 kHz at source levels less than 210 dB re 1 [mu]Pa-m,
and 35 to 45 kHz at less than 220 dB re 1 [mu]Pa-m.
There are many sources of engine noise including but not
limited to surface vessels, submarines, torpedoes, and other UUVs. The
acoustic energy generally ranges from 50 Hz to 10 kHz at source levels
less than 170 dB re 1 [mu]Pa-m. Targets, both mobile and stationary,
may simulate engine noise at these same frequencies.
Additionally, a variety of surface vessels operate active acoustic
depth sensors (fathometers) within the range sites, including Navy,
private, and commercial vessels. In some cases, one or more frequencies
are projected underwater. Bottom type, depth contours, and objects
(e.g., cables, sunken ships) can be located using this equipment. The
depth sensors used by NUWC Keyport are the same fathometers used by
commercial and recreational vessels for navigational safety. Because
these instruments are widely used and are not found to adversely impact
the human or natural environment, they are not analyzed further.
Range Activities: Testing That Involves Non-Acoustic Activities
(1) Magnetic
There are two types: (a) Magnetic sensors, and (b) magnetic
sources. Magnetic sensors are passive and do not have a magnetic field
associated with them. The sensors are bottom mounted, over the side
(stationary or towed) or can be integrated into a UUV. They are used to
sense the magnetic field of an object such as a surface vessel, a
submarine, or a buried target. Magnetic sources are used to represent
magnetic targets or are energized items such as power cables for energy
generators (e.g. tidal). Magnetic sources generate electromagnetic
fields (EMF). Evaluation of EMF (Navy 2008a) has shown that sources
(e.g. Organic Airborne and Surface Influence Sweep (OASIS)) used are
typically below 23 gauss (G) and are considered relatively minute
strength.
(2) Oceanographic Sensor
These sensors have been used historically to determine marine
characteristics such as conductivity, temperature, and pressure of
water to determine sound velocity in water. This provides information
about how sound will travel through the water. These sensors can be
deployed over the side from a surface craft, suspended in water, or
carried on a UUV.
(3) Laser Imaging Detection and Ranging (LIDAR)
Also known as light detection and ranging, LIDAR is used to measure
distance, speed, rotation, and chemical composition and concentration
of remote solid objects such as a ship or submerged object. LIDAR uses
the same principle as radar. The LIDAR instrument transmits short
pulses of laser light towards the target. The transmitted light
interacts with and is changed by the target. Some of this light is
reflected back to the instrument where it is analyzed. The change in
the properties of the light enables some property of the target to be
determined. The time it takes the light to travel to the target and
back to the LIDAR can be used to determine the distance to the target.
Since light attenuates rapidly in water, underwater LIDAR uses light in
the blue-green part of the spectrum as it attenuates the least. Common
civilian uses of LIDAR in the ocean include seabed mapping and fish
detection. All safety issues associated with the use of lasers are
evaluated for all applicable test activities within the range sites
according to Navy and Federal regulations. This bounds the intensity of
LIDAR used pursuant to this request to those systems that meet human
safety standards.
(4) Inert Mine Hunting and Inert Mine Clearing Exercises
Associated with testing, a series of inert mine shapes are set out
in a uniform or random pattern to test the detection, classification
and localization capability of the system under test. They are made
from plastic, metal, and concrete and vary in shape. An inert mine
shape can measure about 10 by 1.75 ft (3 by 0.5 m) and weigh about 800
lbs (362 kg). Inert mine shapes either sit on the bottom or are
tethered by an anchor to the bottom at various depths. Inert mine
shapes can be placed approximately 200-300 yards (183-274 m) apart
using a support craft and remain on the bottom until they need to be
removed. All major components of all inert mine systems used as
`targets' for inert mine hunting systems are removed within 2 years.
NMFS does not believe that those Range activities that involve non-
acoustic testing will have adverse impacts to marine mammals,
therefore,
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they are not analyzed further and will not be covered under the
proposed rule.
Increased Activities Due to Range Extension
The proposed range extension would expand the geographic area for
all three range sites and increase the tempo of activities in the
Keyport and QUTR ranges sites. A detailed list of the proposed annual
range is provided in Table 3.
(1) Keyport Range Site
Range boundaries of the Keyport Range Site would be extended to the
north, east and south, increasing the size of the range from 1.5 nm\2\
to 3.2 nm\2\ (5.1 km\2\ to 11.0 km\2\). The average annual days of use
of the Keyport Range Site would increase from the current 55 days to 60
days.
(2) DBRC Site
The southern boundary of DBRC Site would be extended to the Hamma
Hamma River and its northern boundary would be extended to 1 nm (2 km)
south of the Hood Canal Bridge (Highway 104). This extension would
increase the size of the current operating area from approximately 32.7
nm\2\ (112.1 km\2\) to approximately 45.7 nm\2\ (150.8 km\2\) and would
afford a straight run of approximately 27.5 nm (50.9 km). There would
be no change in the number and types of activities from the existing
range activities at DBRC Site, and no increase in average annual days
of use due to the range extension at this site.
(3) QUTR Site
Range boundaries of QUTR Site would be extended to coincide with
the overlying special use airspace of W-237A plus a 7.8 nm\2\ (26.6
km\2\) surf zone at Pacific Beach. The total range area would increase
from approximately 48.3 nm\2\ (165.5 km\2\) to approximately 1,839.8
nm\2\ (6,310.2 km\2\). The average annual number of days of use for
offshore activities would increase from 14 days/year to 16 days/year in
the offshore area. The average annual days of use for surf-zone
activities would increase from 0 days/year to 30 days/year.
[GRAPHIC] [TIFF OMITTED] TP07JY09.002
Description of Marine Mammals in the Area of the Specified Activities
The information on marine mammals and their distribution and
density are based on the data gathered from NMFS, United States Fish
and Wildlife Service (USFWS) and recent references, literature searches
of search engines, peer review journals, and other technical reports,
to provide a regional context for each species. The data were compiled
from available sighting records, literature, satellite tracking, and
stranding and by-catch data.
A total of 24 cetacean species and subspecies and 5 pinniped
species are known to occur in Washington State waters; however, several
are seen only rarely. Seven of these marine mammal species are listed
as Federally-endangered under the Endangered Species Act (ESA) occur or
have the potential to occur in the proposed action area: blue whale
(Balaenoptera musculus), fin whale (B. physalus), Sei whale (B.
borealis), humpback whale (Megaptera novaengliae), north Pacific right
whale (Eubalaena japonica), sperm whale (Physeter macrocephalus), and
the southern resident population of
[[Page 32269]]
killer whales (Orcinus orca). The species, Steller sea lion (Eumetopias
jubatus), is listed as threatened under the ESA.
Survey data concerning the inland waters of Puget Sound are sparse.
There have been few comprehensive studies of marine mammals in inland
waters, and those that have occurred have focused on inland waters
farther north (Strait of Juan de Fuca, San Juan/Gulf Islands, Strait of
Georgia) (Osmek et al., 1998). Most published information focuses on
single species (e.g., harbor seals, Jeffries et al., 2003) or are stock
assessment reports published by NMFS (e.g., Carretta et al., 2008).
Survey data for the offshore waters of Washington State, including
the area of the QUTR Site, are somewhat better, particularly for
cetaceans. The NMFS conducted vessel surveys in the region in 1996 and
2001, which are summarized in Barlow (2003) and Appler et al. (2004).
Vessel surveys were again conducted by NMFS in summer 2005, and
included finer-scale survey lines within the OCNMS (Forney, 2007).
Cetacean densities from this most recent effort were used wherever
possible; older density values (2001 or 1996) were used when more
recent values were not available. Some cetacean densities (gray and
killer whale, harbor porpoise) were obtained from sources other than
the broad scale surveys indicated above and the methodologies of
deriving the densities are included in the Navy's LOA application.
Pinniped at-sea density is not often available because pinniped
abundance is most often obtained via shore counts of animals at known
rookeries and haulouts. Therefore, densities of pinnipeds were derived
differently from those of cetaceans. Several parameters were identified
from the literature, including area of stock occurrence, number of
animals (which may vary seasonally) and season, and those parameters
were then used to calculate density. Determining density in this manner
is risky as the parameters used usually contain error (e.g., geographic
range is not exactly known and needs to be estimated, abundance
estimates usually have large variances) and, as is true of all density
estimates, they assume that animals are always distributed evenly
within an area, which is likely rarely true. However, this remains one
of the few means available to determine at-sea density for pinnipeds.
Sea otters occur along the northern Washington coast. Density of
sea otters was published as animals/km, which was modified to provide
density per area. Since sea otters are under the U.S. Fish and Wildlife
Service jurisdiction, they are not considered in this document.
The following are brief descriptions of the temporal and spatial
distribution and abundance of marine mammals throughout the NAVSEA NUWC
Keyport Range Complex Extension.
Keyport Range Site
A total of five cetaceans and three pinnipeds are known to occur
within central Puget Sound, which encompasses the Keyport action area,
but several of these species have never been observed in Port Orchard
Narrows or in the action area (Table 4). Humpback whales, minke whales,
killer whales, and Steller sea lions are expected to be uncommon to
rare in southern Puget Sound and have never been seen in the Keyport
action area. Density estimates for these species are available for
Puget Sound as a whole, but since these species have never been
recorded or observed in the action area, the densities for the action
area are shown as ``0'' to reflect this. The proposed extension area of
the Keyport Range Site is listed as critical habitat for Southern
Resident killer whales. The current Keyport Range Site is outside the
critical habitat area.
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DBRC Site
Six cetaceans and three pinnipeds are known to occur or potentially
occur within the DBRC action area (Table 5). Density estimates for
these species are available for Puget Sound as a whole, but since these
species have never been recorded or observed in the action area, the
densities for the action area are shown as ``0'' to reflect this. There
is no designated or proposed critical habitat for marine mammals within
the DBRC action area.
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[GRAPHIC] [TIFF OMITTED] TP07JY09.004
3.2.3 QUTR Site
The diversity of marine mammals that occur in QUTR is greater than
that in the Puget Sound ranges and is listed in Table 6.
BILLING CODE 3510-22-P
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[GRAPHIC] [TIFF OMITTED] TP07JY09.006
More detailed description of marine mammal density estimates within
the NAVSEA NUWC Keyport Range Complex Extension is provided in the
Navy's LOA application.
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 61.5 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 98.5 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)
designated ``functional hearing groups'' and estimated the lower and
upper frequencies of functional hearing of the groups. Further, the
frequency range in which each group's hearing is estimated as being
most sensitive is represented in the flat part of the M-weighting
functions 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
cetacean. When sound travels away from its source, its loudness
decreases as the distance from the source increases (propagation).
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
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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 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. 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. Surface-ship hull-mounted
sonars, known as tactical sonars, are not used by NAVSEA NUWC Keyport.
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 the received levels at which 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 following sections discuss the potential effects from noise
related to active acoustic devices that would be used in the proposed
Keyport Range Complex Extension.
For activities involving active acoustic sources such as tactical
sonar, NMFS's analysis identifies the probability of lethal responses,
physical trauma, sensory impairment (permanent and temporary threshold
shifts and acoustic masking), physiological responses (particular
stress responses), behavioral disturbance (that rises to the level of
harassment), and social responses that would be classified as
behavioral harassment or injury and/or would be likely to adversely
affect the species or stock through effects on annual rates of
recruitment or survival. It should be noted that the description below
is based on more powerful mid-frequency active sonar (MFAS) used on
surface ships. The NAVSEA NUWC Keyport Range does not utilize these
sources in RDT&E activities. Many of these severe effects (e.g.,
mortality, acoustically mediated bubble growth, and stranding) are not
likely to occur for acoustic sources used in the proposed Keyport Range
activities, as shown in Estimated Takes of Marine Mammals section.
Direct Physiological Effects
Based on the literature, there are two basic ways that 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 as with TTS occurs in a specific
frequency range and amount.
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
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longer but softer sound, which in turn may cause more impairment than a
series of several intermittent softer sounds with the same total energy
(Ward, 1997). Additionally, though TTS is temporary, very prolonged
exposure to sound strong enough to elicit TTS, or shorter-term exposure
to sound levels well above the TTS threshold, can cause PTS, at least
in terrestrial mammals (Kryter, 1985) (although in the case of MFAS,
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 a 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
conspecific, 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 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
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 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
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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 marine
mammals all encompass the frequencies of the active acoustic sources
used in the Navy's Keyport Range activities. Additionally, almost all
species' vocal repertoires span across the frequencies of the 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 source signals are
of short duration and would not be continuous, masking is unlikely to
occur as a result of exposure to active acoustic sources during the
RDT&E activities in the Keyport Range Complex Extension 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 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 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 hypothalmus-pituitary-adrenal
system (also known as the HPA axis in mammals or the hypothalamus-
pituitary-interrenal axis in fish and some reptiles). Unlike stress
responses associated with the autonomic nervous system, virtually all
neuro-endocrine functions that are affected by stress--including immune
competence, reproduction, metabolism, and behavior--are regulated by
pituitary hormones. Stress-induced changes in the secretion of
pituitary hormones have been implicated in failed reproduction (Moberg,
1987; Rivier, 1995) and altered metabolism (Elasser et al., 2000),
reduced immune competence (Blecha, 2000) and behavioral disturbance.
Increases in the circulation of glucocorticosteroids (cortisol,
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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 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
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 anthropogenic sound with the goal of proposing exposure
criteria for certain effects. This compilation of literature is very
valuable, though Southall et al. notes that not all data is equal: Some
have poor statistical power, insufficient controls, and/or limited
information on received levels, background noise, and
[[Page 32278]]
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. Sonar signal 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 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 sonar signals)
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 sonar signals) 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 sonar signals) 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), 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 7 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.
Table 7--Data Compiled From Three Tables From Southall et al. (2007) Indicating When Marine Mammals (Low-Frequency Cetacean = L, Mid-Frequency Cetacean = M, and High-Frequency Cetacean = H)
Were Reported as Having a Behavioral Response of the Indicated Severity to a Non-Pulse Sound of the Indicated Received Level
[As discussed in the text, responses are highly variable and context specific]
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Response Score
-----------------------------------------------------------------------------------------------------------------------------------
Received RMS sound pressure level (dB re 1 microPa) 90 to < 100 to < 110 to 120 to < 130 to < 140 to < 150 to < 160 to < 170 to < 180 to < 190 to <
80 to <90 100 110 <120 130 140 150 160 170 180 190 200
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
9........................................................... ......... ......... ......... ......... ......... ......... ......... ......... ......... ......... ......... .........
8........................................................... ......... M M ......... M ......... M ......... ......... ......... M M
7........................................................... ......... ......... ......... ......... ......... L L ......... ......... ......... ......... .........
6........................................................... H L/H L/H L/M/H L/M/H L L/H H M/H M ......... .........
5........................................................... ......... ......... ......... ......... M ......... ......... ......... ......... ......... ......... .........
4........................................................... ......... ......... H L/M/H L/M ......... L ......... ......... ......... ......... .........
3........................................................... ......... M L/M L/M M ......... ......... ......... ......... ......... ......... .........
2........................................................... ......... ......... L L/M L L L ......... ......... ......... ......... .........
1........................................................... ......... ......... M M M ......... ......... ......... ......... ......... ......... .........
0........................................................... L/H L/H L/M/H L/M/H L/M/H L M ......... ......... ......... M M
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 32279]]
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 exist for terrestrial species from 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 (such as 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 as
foraging. These costs have been documented best in foraging animals,
where vigilance has been shown to substantially reduce feeding rates
(Saino, 1994; Beauchamp and Livoreil, 1997; Fritz et al., 2002).
Animals will spend more time being vigilant, which may translate to
less time foraging or resting, when disturbance stimuli approach them
more directly, remain at closer distances, have a greater group size
(for example, multiple surface vessels), or when they co-occur with
times that an animal perceives increased risk (for example, when they
are giving birth or accompanied by a calf). Most of the published
literature, however, suggests that direct approaches will increase the
amount of time animals will dedicate to being vigilant. For example,
bighorn sheep and Dall's sheep dedicated more time being vigilant, and
less time resting or foraging, when aircraft made direct approaches
over them (Frid, 2001; Stockwell et al., 1991).
Several authors have established that long-term and intense
disturbance stimuli can cause population declines by reducing the body
condition of individuals that have been disturbed, followed by reduced
reproductive success, reduced survival, or both (Daan et al., 1996;
Madsen, 1994; White, 1983). For example, Madsen (1994) reported that
pink-footed geese (Anser brachyrhynchus) in undisturbed habitat gained
body mass and had about a 46-percent reproductive success compared with
geese in disturbed habitat (being consistently scared off the fields on
which they were foraging) which did not gain mass and had 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 103 kJ/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) 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
[[Page 32280]]
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 strandings or 68 percent), followed
by sperm whales (7 strandings 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 mass
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 low intensity sonars and low intensity
acoustic sources are proposed for the Keyport Range Complex RDT&E and
range extension activities, and no powerful MFAS such as the 53C series
tactical sonar would be used for these activities; therefore, their
zones of influence are much smaller compared to these highest powered
surface vessel sources, and animals can be more easily detected in
these smaller areas, 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 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. 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), 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 make 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 strand and
be injured.
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 startle response to exposure to active sonar or to
further avoid exposure (Cox et al., 2006, Rommel et al., 2006). These
authors proposed three mechanisms by which the behavioral responses of
beaked whales upon being exposed to active sonar might result in a
stranding event. These include: Gas bubble formation caused by
excessively fast surfacing; remaining at the surface too long when
tissues are supersaturated with nitrogen; or diving prematurely when
extended time at the surface is necessary to eliminate excess nitrogen.
More specifically, beaked whales that occur in deep waters that are in
close proximity to shallow waters (for example, the ``canyon areas''
that are cited in the Bahamas stranding event; see D'Spain and D'Amico,
2006), may respond to active sonar by swimming into shallow waters to
avoid further exposures and strand if they were not able to swim back
to deeper waters. Second, beaked whales exposed to active sonar might
alter their dive behavior. Changes in their dive behavior might cause
them to remain at the surface or at depth for extended periods of time,
which could lead to hypoxia directly by increasing their oxygen demands
or indirectly by increasing their energy expenditures (to remain at
depth) 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
[[Page 32281]]
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 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) summarizes 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 to which 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 RDT&E
activities within the Keyport Range Complex Extension would not involve
multi-vessel operations, would not use powerful sonar such as the AN/
SQQ-53C/56 MFAS, and the bathymetry bears no similarity to 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
Keyport Range operations (which involve less powerful active sonar
(MFAS/HFAS) and other sound sources, and no high-speed, multi-vessel
training scenarios) and the fact that the Keyport Range Complex
Extension 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
Keyport Range Complex region.
Estimated Take of Marine Mammals
With respect to the MMPA, NMFS's effects assessment serves four
primary purposes: (1) To prescribe the permissible methods of taking
(i.e., Level B Harassment (behavioral
[[Page 32282]]
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
Keyport Range Complex Study Area, so this determination is inapplicable
for this rulemaking); and (4) to prescribe requirements pertaining to
monitoring and reporting.
In the Potential Impacts to Marine Mammal Species section, 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 active
acoustic sources (e.g., powerful sonar). In this section, we will
relate the potential effects to marine mammals from active acoustic
sources 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 Keyport
Range Complex.
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
Impacts to Marine Mammals Species section, the following are the types
of effects that fall into the Level B Harassment category:
Behavioral Harassment--Behavioral disturbance that rises to the
level described in the definition above, when resulting from exposures
to active acoustic sources, 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 active acoustic sources) as Level B Harassment, not Level A
Harassment (injury).
Level A Harassment
Of the potential effects that were described in the Potential
Impacts to Marine Mammal Species section, following are the types of
effects that fall into the Level A Harassment category:
PTS--PTS (resulting either from exposure to active acoustic
sources) 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 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.).
Acoustic Take Criteria for Naval Sonar
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/
[[Page 32283]]
MFAS 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 the received level (when exposed to HFAS/MFAS) at which Level
B or Level A harassment would occur. The acoustic criteria for HFAS/
MFAS are discussed below.
Because relatively few applicable data exist to support acoustic
criteria specifically for HFAS, and it is suspected that the majority
of the adverse effects 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 LOA application for the Keyport Range Complex RDT&E and range
extension activities.
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.
Mooney et al. (2009) exposed a bottlenose dolphin with a
``typical'' mid-frequency naval sonar signal (two down sweeps of 0.5 s
each separated by a 0.5 s gap, fundamental frequency approximately 3-4
kHz with multiple harmonics) recorded within the Puget Sound,
Washington. Successive three-ping blocks, each block spaced 24 s apart,
were used to simulate a ``typical'' mid-frequency sonar application. To
evaluate TTS, hearing thresholds for a 5.6 kHz tone were measured
before and after noise exposure using the physiological method of
auditory evoked potentials. Sonar SPLs were gradually increased up to
203 dB SPL (rms) (measured at the location of the dolphin's ear) for
individual pings. The ping number was then increased over multiple
exposure sessions until a threshold shift was induced. Results showed
that only the five blocks of sonar pings, presenting an SPL of 203 dB
(SEL of 214 dB re 1 microPa\2\-s), reliably induced shifts for three
consecutive research sessions.
Kastak et al. (1999a, 2005) conducted TTS experiments with
three species of pinnipeds, California sea lion, northern elephant seal
and a Pacific harbor seal, exposed to continuous underwater sounds at
levels of 80 and 95 dB sensation level (the level above its hearing
threshold) at 2.5 and 3.5 kHz for up to 50 minutes. Mean TTS shifts of
up to 12.2 dB occurred with the harbor seals showing the largest shift
of 28.1 dB. Increasing the sound duration had a greater effect on TTS
than increasing the sound level from 80 to 95 dB.
Some of the more important data obtained from these studies are
onset-TTS levels (exposure levels sufficient to cause a just-measurable
amount of TTS) often defined as 6 dB of TTS (for example, Schlundt et
al., 2000) and the fact that energy metrics (sound exposure levels
(SEL), which include a duration component) better predict when an
animal will sustain TTS than pressure (SPL) alone. NMFS' TTS criteria
(which indicate the received level at which onset TTS (<6dB) is
induced, expressed in SELs) 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)).
Pinnipeds:
--Harbor Seals (and closely related species)--183 dB re 1 microPa\2\-s
--Northern Elephant Seals (and closely related species)--204 dB re 1
microPa\2\-s
--California Sea Lions (and closely related species)--206 dB re 1
microPa\2\-s
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 Keyport Range Complex LOA
application.
[[Page 32284]]
Level A Harassment Threshold (PTS)
For acoustic effects, because the tissues of the ear appear to be
the most susceptible to the physiological effects of sound, and because
threshold shifts tend to occur at lower exposures than other more
serious auditory effects, NMFS has determined that PTS is the best
indicator for the smallest degree of injury that can be measured.
Therefore, the acoustic exposure associated with onset-PTS is used to
define the lower limit of the Level A harassment.
PTS data do not currently exist for marine mammals and are unlikely
to be obtained due to ethical concerns. However, PTS levels for these
animals may be estimated using TTS data from marine mammals and
relationships between TTS and PTS that have been discovered through
study of terrestrial mammals. NMFS uses the following acoustic criteria
for injury (expressed in SELs):
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)).
Pinnipeds:
--Harbor Seals (and closely related species)--203 dB re 1 microPa\2\-s
--Northern Elephant Seals (and closely related species)--224 dB re 1
microPa\2\-s
--California Sea Lions (and closely related species)--226 dB re 1
microPa\2\-s
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 Keyport Range Complex 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 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), Atlantic Fleet Active
Sonar Testing (AFAST), and the Naval Surface Warfare Center Panama City
Division (NSWC PCD) mission activities. 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.
The methodology described below is based on surface ship acoustic
sources. The NAVSEA NUWC Keyport Range does not utilize these sources
in RDT&E activities. It should be noted though, that the sources
methodology described below is utilized for the modeling of potential
exposures to mid- and high-frequency active sonar.
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 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 become 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 satisfies 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.
[[Page 32285]]
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] TP07JY09.000
Where:
R = Risk (0-1.0)
L = Received level (dB re: 1 [mu]Pa)
B = Basement received level = 120 dB re: 1 [mu]Pa
K = Received level increment above B where 50 percent risk = 45 dB
re: 1 [mu]Pa
A = Risk transition sharpness parameter = 10 (odontocetes) or 8
(mysticetes)
In order to use this function to estimate the percentage of an
exposed population that would respond in a manner that NMFS classifies
as Level B harassment, based on a given received level, the values for
B, K and A need to be identified.
B Parameter (Basement)--The B parameter is the estimated received
level below which the probability of disruption of natural behavioral
patterns, such as migration, surfacing, nursing, breeding, feeding, or
sheltering, to a point where such behavioral patterns are abandoned or
significantly altered approaches zero for the 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 re 1 [mu]Pa (SPL). 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 are available,
however, NMFS and the Navy have determined that the following three
data sets are most applicable for direct use in establishing the K
parameter for the 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 C of the NAVSEA NUWC Keyport Range Complex
Extension EIS/OEIS.
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 two separate
TTS experiments using 1-sec tones at 3 kHz. The test methods were
similar to that of Schlundt et al. (2000) except the tests were
conducted in a pool with very low ambient noise level (below 50 dB re 1
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 are 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
[[Page 32286]]
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.
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 animals 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 here 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 Pa
rms), the risk (or probability) of harassment is defined according to
this function as 50 percent, and Navy/NMFS applies that by estimating
that 50 percent of the individuals exposed at that received level are
likely to respond by exhibiting behavior that NMFS would classify as
behavioral harassment. The risk function is not applied to individual
animals, only to exposed populations.
The data primarily used to produce the risk function (the K
parameter) were compiled from four species that had been exposed to
sound sources in a variety of different circumstances. As a result, the
risk function represents a general relationship between acoustic
exposures and behavioral responses that is then applied to specific
circumstances. That is, the risk function represents a relationship
that is deemed to be generally true, based on the limited, best-
available science, but may not be true in specific circumstances. In
particular, the risk function, as currently derived, treats the
received level as the only variable that is relevant to a marine
mammal's behavioral response. However, we know that many other
variables--the marine mammal's gender, age, and prior experience, the
activity it is engaged in during an exposure event, its distance from a
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 32287]]
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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).
Specific Consideration for Harbor Porpoises
The information currently available regarding these inshore species
that inhabit shallow and coastal waters suggests a very low threshold
level of response for both captive and wild animals. Threshold levels
at which both captive (e.g., Kastelein et al., 2000; 2005a; 2006) and
wild harbor porpoises (e.g., Johnston, 2002) responded to sound (e.g.,
acoustic harassment devices (ADHs), acoustic deterrent devices (ADDs),
or other non-pulsed sound sources) is very low (e.g., ~120 dB SPL),
although the biological significance of the disturbance is uncertain.
Therefore, the risk function curve as presented is not used. Instead, a
step function threshold of 120 dB SPL is used to estimate take of
harbor porpoises (i.e., assumes that all harbor porpoises exposed to
120 dB or higher MFAS/HFAS will respond in a way NMFS considers
behavioral harassment).
Modeling Acoustic Effects
The methodology for analyzing potential impacts from mid- and high-
frequency acoustic sources is presented in this section, which defines
the model process in detail, describes how the impact threshold derived
from Navy-NMFS consultations are derived, and discusses relative
potential impact based on species biology.
Modeling methods applied herein were originally developed for mid-
frequency (1-10 kHz) active (MFA) sonars (e.g., surface-ship hull-
mounted sonars, which are not used in the NAVSEA NUWC Keyport Range
Complex). Nevertheless, the methods and thresholds are agreed upon by
the U.S. Navy and NMFS as the best available science with which to
determine the extent of physiological or behavioral effects on marine
mammals that would result from the use of mid-frequency active (MFA)
and high frequency active (HFA) acoustic sources for this proposed
action. Detailed descriptions of the modeling process and results are
provided in LOA Application.
The Navy acoustic exposure model process uses a number of inter-
related software tools to assess potential exposure of marine mammals
to Navy generated underwater sound. For sonar, these tools estimate
potential impact volumes and areas over a range of thresholds for sonar
specific operating modes. Results are based upon extensive pre-
computations over the range of acoustic environments that might be
encountered in the operating area.
The process includes four steps used to calculate potential
exposures:
Identify unique acoustic environments that encompass the
operating area. Parameters include depth and seafloor geography, bottom
characteristics and sediment type, wind and surface roughness, sound
velocity profile, surface duct, sound channel, and convergence zones.
Compute transmission loss (TL) data appropriate for each
sensor type in each of these acoustic environments.
[[Page 32288]]
Propagation can be complex depending on a number of environmental
parameters listed in step one, as well as sonar operating parameters
such as directivity, source level, ping rate, and ping length. The Navy
standard CASS-GRAB acoustic propagation model is used to resolve these
complexities for underwater propagation prediction.
Use that TL to estimate the total sound energy received at
each point in the acoustic environment.
Apply this energy to predicted animal density for that
area to estimate potential acoustic exposure, with animals distributed
in 3-D based on best available science on animal dive profiles.
The primary potential impact to marine mammals from underwater
acoustics is Level B harassment from noise. A certain proportion of
marine mammals are expected to experience behavioral disturbance at
different received sound pressure levels and are counted as Level B
harassment exposures. A detailed discussion of the modeling is provided
in the Navy's LOA application.
Step 1. Acoustic Sources
For modeling purposes, acoustic source parameters were based on
records from previous RDT&E activities, to reflect the underwater sound
use expected to occur during activities in the NAVSEA NUWC Keyport
Range Complex. The actual acoustic source parameters in many cases are
classified, however, modeling used to calculate exposures to marine
mammals employed actual and preferred parameters which have in the past
been used during RDT&E activities in the NAVSEA NUWC Keyport Range
Complex.
Every use of underwater acoustic energy includes the potential to
harass marine animals in the vicinity of the source. The number of
animals exposed to potential harassment in any such action is dictated
by the propagation field and the manner in which the acoustic source is
operated (i.e., source level, depth, frequency, pulse length,
directivity, platform speed, repetition rate). A wide variety of
systems/equipment that utilize narrowband acoustic sources are employed
at the NAVSEA NUWC Keyport Range Complex. Eight have been selected as
representative of the types of operating in this range and are
described in Table 8. Take estimates for these sources are calculated
and reported on a per-run basis.
Table 8--Mid- and High-Frequency Acoustic Sources Employed in the Keyport Range Complex
----------------------------------------------------------------------------------------------------------------
Acoustic source
Source designation description Frequency class Takes reported
----------------------------------------------------------------------------------------------------------------
S1............................... Sub-bottom profiler. Mid-frequency....... Per 4-hour run.
S2............................... UUV source.......... High-frequency...... Per 2-hour run.
S3............................... REMUS Modem......... Mid-frequency....... Per 2-hour run.
S4............................... REMUS-SAS-HF........ High-frequency...... Per 2-hour run.
S5............................... Range Target........ Mid-frequency....... Per 20-minute run.
S6............................... Test Vehicle 1...... High-frequency...... Per 10-minute run.
S7............................... Test Vehicle 2...... High-frequency...... Per 10-minute run.
S8............................... Test Vehicle 3...... High-frequency...... Per 10-minute run.
----------------------------------------------------------------------------------------------------------------
The acoustic modeling that is necessary to support the take
estimates for each of these sources relies upon a generalized
description of the manner of the operating modes. This description
includes the following:
``Effective'' energy source level--The total energy across
the band of the source, scaled by the pulse length (10 log10 [pulse
length]).
Source depth--Depth of the source in meters. Each source
was modeled in the middle of the water column.
Nominal frequency--Typically the center band of the source
emission. These are frequencies that have been reported in open
literature and are used to avoid classification issues. Differences
between these nominal values and actual source frequencies are small
enough to be of little consequence to the output impact volumes.
Source directivity--The source beam is modeled as the
product of a horizontal beam pattern and a vertical beam pattern. Two
parameters define the horizontal beam pattern:
Horizontal beam width--Width of the source beam (degrees)
in the horizontal plane (assumed constant for all horizontal steer
directions).
Horizontal steer direction--Direction in the horizontal in
which the beam is steered relative to the direction in which the
platform is heading.
The horizontal beam has constant response across the width of the
beam and with flat, 20-dB down sidelobes. (Note that steer directions
[phi], -[phi], 180o - [phi], and 180o + [phi] all produce equal impact
volumes.)
Similarly, two parameters define the vertical beam pattern:
Vertical beam width--Width of the source beam (degrees) in
the vertical plane measured at the 3-dB down point. (The width is that
of the beam steered towards broadside and not the width of the beam at
the specified vertical steer direction.)
Vertical steer direction--Direction in the vertical plane
that the beam is steered relative to the horizontal (upward looking
angles are positive).
To avoid sharp transitions that a rectangular beam might introduce,
the power response at vertical angle [thgr] is
[GRAPHIC] [TIFF OMITTED] TP07JY09.001
where n = 180[deg]/[thgr]w is the number of half-wavelength-
spaced elements in a line array that produces a main lobe with a beam
width of [thgr]w. [thgr]s is the vertical beam
steer direction.
Ping spacing--Distance between pings. For most sources this is
generally just the product of the speed of advance of the platform and
the repetition rate of the source. Animal motion is generally of no
consequence as long as the source motion is greater than the speed of
the animal (nominally, three knots). For stationary (or nearly
stationary) sources, the ``average'' speed of the animal is used in
place of the platform speed. The attendant assumption is that the
animals are all moving in the same constant direction.
These parameters are defined for each of the acoustic sources in
the following Table 9.
[[Page 32289]]
Table 9--Description of NAVSEA NUWC Keyport Range Complex Sources
--------------------------------------------------------------------------------------------------------------------------------------------------------
Horizontal
Acoustic source description Center frequency Source level Emission spacing Vertical directivity directivity
horizontal horizontal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sub-bottom profiler................ 4.5 kHz............... 207 dB................ 0.2 m................ 20 deg............... 20 deg.
UUV source......................... 15 kHz................ 205 dB................ 1.9 m................ 30 deg............... 50 deg.
REMUS Modem........................ 10 kHz................ 186 dB................ 45 m................. 60 deg............... 360 deg.
REMUS-SAS-HF....................... 150 kHz............... 220 dB................ 1.9 m................ 9 deg................ 15 deg.
Range Target....................... 5 kHz................. 233 dB................ 93 m................. 60 deg............... 360 deg.
Test Vehicle 1..................... 20 kHz................ 233 dB................ 45 m................. 20 deg............... 60 deg.
Test Vehicle 2..................... 25 kHz................ 230 dB................ 540 m................ 20 deg............... 60 deg.
Test Vehicle 3..................... 30 kHz................ 233 dB................ 617 m................ 20 deg............... 60 deg.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Step 2. Environmental Provinces
Propagation loss ultimately determines the extent of the Zone of
Influence (ZOI) for a particular source activity. Propagation loss as a
function of range responds to a number of environmental parameters:
Water depth
Sound speed variability throughout the water column
Bottom geo-acoustic properties, and
Wind speed
Due to the importance that propagation loss plays in modeling
effects, the Navy has over the last four to five decades invested
heavily in measuring and modeling these environmental parameters. The
result of this effort is the following collection of global databases
of these environmental parameters, most of which are accepted as
standards for all Navy modeling efforts.
Water depth--Digital Bathymetry Data Base Variable
Resolution (DBDBV)
Sound speed--Generalized Digital Environmental Model
(GDEM)
Bottom loss--Low-Frequency Bottom Loss (LFBL), Sediment
Thickness Database, and High-Frequency Bottom Loss (HFBL), and
Wind speed--U.S. Navy Marine Climatic Atlas of the World
Representative environmental parameters are selected for each of
the three operating areas: DBRC, Keyport, and Quinault. Sources of
local environmental-acoustic properties were supplemented with Navy
Standard OAML data to determine model inputs for bathymetry, sound-
speed, and sediment properties.
The DBRC and Keyport ranges are located inland with limited water-
depth variability: The maximum water depth in Dabob Bay is
approximately 200 meters; the maximum in the Keyport range is
approximately 30 meters (98 feet). The Quinault range, on the other
hand, is located seaward of the Washington State Coast to depths
greater than a kilometer.
Sound speed profiles for winter and summer from the OAML open-ocean
database are presented in Figure 6-10 of the Navy's LOA application.
The winter profile is a classic half-channel (sound speed monotonically
increasing with depth). The summer profile consists of a shallow
surface duct over a modest thermocline. Individual profiles taken from
World Ocean Data Base (NODC, 2005) for DBRC and Keyport are generally
consistent with these open-ocean profiles. Some of these profiles
exhibit some effects of additional fresh water near the surface; others
have a little warmer surface layer than this summer profile. However,
the truncated deep-water profiles are adequately representative of the
inland ranges.
The bottom type in the Quinault range varies consistently with
water depth. The shallower depths (less than 500 meters) tend to have
sandy bottoms (HFBL class = 2); the deeper depths tend to be silt (HFBL
class = 8).
The sediment type of the DBRC and Keyport areas that we used for
our modeling were different from those found in the Low Frequency
Bottom Loss (LFBL) database or implied by the High-Frequency Bottom
Loss (HFBL) database. Although the water depth of these areas can be
greater that 50 m, the LFBL database assigned them the default ``coarse
sand'' sediment type that was assigned to areas with water depth less
than 50 m (Vidmar, 1994). Core data from these areas were collected as
part of environmental monitoring (Llanso, 1998). Cores 14 and 15 from
the northern parts of the DBRC area indicated sediments with sands and
silty sands. A silty sand sediment type was assigned to these areas
(HFBL class = 2). Core 304R from the southern part of the DBRC area
indicated sediments with clay. A clay-silt sediment type (HFBL class =
4) was assigned to this area taking into account the transition from
the more sandy northern area to the clay of the southern area. These
assignments are consistent with the observation (Helton, 1976) that the
boundary area between the northern and southern areas had sediments
that were mostly mud with a small amount of sand. The Keyport area did
not have any cores in the study area but had three cores surrounding
the area: Core 308R to the northwest indicated sand sediment; core 69
to the northeast indicated sand and silty sand sediments; and core 34
to the south indicated clay sediment. Given the surrounding cores we
assigned a sand-silt-clay sediment type to this area (HFBL class = 4).
The Keyport range has a proposed extension to the east and south of
the existing boundaries. In addition to the existing DBRC boundary,
there is one extension to the south and another extension to the south
and the north. The Quinault range is extended into a much larger deep-
water region coincident with W-237A with a surf zone at Pacific Beach.
Step 3. Impact Volumes and Impact Ranges
Many naval actions include the potential to injure or harass marine
animals in the neighboring waters through noise emissions. Given fixed
harassment metrics and thresholds, the number of animals exposed to
potential harassment in any such action is dictated by the propagation
field and the characteristics of the noise source.
The expected impact volume associated with a particular activity is
defined as the expected volume of water in which some acoustic metric
exceeds a specified threshold. The product of this volume with a
volumetric animal density yields the expected value of the number of
animals exposed to that acoustic metric at a level that exceeds the
threshold. There are two acoustic metrics for mid- and high-frequency
acoustic sources effects: An energy term (energy flux density) or a
pressure term (peak pressure). The thresholds associated with each of
these metrics define the levels at which the animals exposed will
experience some degree of harassment (ranging from behavioral change to
hearing loss).
Impact volume is particularly relevant when trying to estimate the
effect of repeated source emissions separated in either time or space.
Impact range is
[[Page 32290]]
defined as the maximum range at which a particular threshold is
exceeded for a single source emission.
The two measures of potential harm to marine wildlife due to mid-
and high-frequency acoustic sources operations are the accumulated
(summed over all source emissions) energy flux density received by the
animal over the duration of the activity, and the peak pressure
(loudest sound received) by the animal over the duration of the
activity.
Regardless of the type of source, estimating the number of animals
that may be harassed in a particular environment entails the following
steps.
Each source emission is modeled according to the
particular operating mode of that source. The ``effective'' energy
source level is computed by integrating over the bandwidth of the
source, and scaling by the pulse length. The location of the source at
the time of each emission must also be specified.
For the relevant environmental acoustic parameters,
Transmission Loss (TL) estimates are computed, sampling the water
column over the appropriate depth and range intervals. TL data are
sampled at the typical depth(s) of the source and at the nominal center
frequency of the source.
The accumulated energy and maximum sound pressure level
(SPL) are sampled over a volumetric grid within the waters surrounding
a source action. At each grid point, the received signal from each
source emission is modeled as the source level reduced by the
appropriate propagation loss from the location of the source at the
time of each emission to that grid point. The maximum SPL field is
calculated by taking the maximum level of the received signal over all
emissions, and the energy field is calculated by summing the energy of
the signal over all emissions, and adjusting for pulse length.
The impact volume for a given threshold is estimated by
summing the incremental volumes represented by each grid point for
which the appropriate metric exceeds that threshold. For maximum SPL,
calculation of the expected volume represented by each grid point
depends on the maximum SPL at that point, and requires an extra step to
apply the risk function.
Finally, the number of takes is estimated as the product (scalar or
vector, depending upon whether an animal density depth distribution is
available) of the impact volume and the animal densities.
(4) Computing Impact Volumes for Active Sonars
The computation for impact volumes of active acoustic sources uses
the following steps:
Identification of the underwater propagation model used to
compute transmission loss data, a listing of the source-related inputs
to that model, and a description of the output parameters that are
passed to the energy accumulation algorithm.
Definitions of the parameters describing each acoustic
source type.
Description of the algorithms and sampling rates
associated with the energy accumulation algorithm.
A detailed discussion of computing methodologies is provided in the
Navy's LOA application.
Estimated Takes of Marine Mammals
When analyzing the results of the acoustic exposure modeling to
provide an estimate of effects, it is important to understand that
there are limitations to the ecological data used in the model, and
that the model results must be interpreted within the context of a
given species' ecology. When reviewing the acoustic effects modeling
results, it is also important to understand there have been no
confirmed acoustic effects on any marine species in previous NAVSEA
NUWC Keyport Range Complex exercises or from any other mid- and high-
frequency active sonar RDT&E activities within the NAVSEA NUWC Keyport
Range Complex.
The annual estimated number of exposures from acoustic sources are
given for each species. The modeled exposure is the probability of a
response that NMFS would classify as harassment under the MMPA. These
exposures are calculated for all activities modeled and represent the
total exposures per year and are not based on a per day basis.
Range Operating Policies and Procedures (ROP) Description operating
policies and procedures, as described in NUWC Keyport Report 1509,
Range Operating Policies and Procedures Manual (ROP), are followed for
all NUWC Keyport range activities. NUWC Keyport would continue to
implement the ROP policies and procedures within the NAVSEA NUWC
Keyport Range Complex with implementation of the proposed range
extension. The ROP is followed to protect the health and safety of the
public and Navy personnel and equipment as well as to protect the
marine environment. The policies and procedures address issues such as
safety, development of approved run plans, range operation personnel
responsibility, deficiency reporting, all facets of range activities,
and the establishment of ``exclusion zones'' to ensure that there are
no marine mammals within a prescribed area prior to the commencement of
each in-water exercise within the NAVSEA NUWC Keyport Range Complex.
All range operators are trained by NOAA in marine mammal
identification, and active acoustic activities are suspended or delayed
if whales, dolphins, or porpoises (cetaceans) are observed within range
areas.
The modeling for acoustic sources using the risk function
methodology predicts 15,130 annual acoustic exposures that result in
Level B harassment and 2,026 annual exposures of pinnipeds that exceed
the TTS threshold for Level B Harassment under these criteria. The
model predicts 0 annual exposures that exceed the PTS threshold (Level
A Harassment). The Navy is not requesting Level A harassment
authorization for any marine mammal. The summary of modeled mid- and
high-frequency acoustic source exposure harassment numbers by species
are presented in Tables 9 through 12 and represent potential harassment
after implementation of the ROP. Implementation of the ROP would result
in a zero take with respect to all cetaceans except for the harbor
porpoise.
[[Page 32291]]
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[[Page 32292]]
[GRAPHIC] [TIFF OMITTED] TP07JY09.010
It is highly unlikely that a marine mammal would experience any
long-term effects because the large NAVSEA NUWC Keyport Range Complex
test areas make individual mammals' repeated and/or prolonged exposures
to high-level sonar signals unlikely. Specifically, mid- and high-
frequency acoustic sources have limited marine mammal exposure ranges
and relatively high platform speeds. Moreover, there are no exposures
that exceed the PTS threshold and result in Level A harassment from
sonar and other active acoustic sources. Therefore, long-term effects
on individuals, populations or stocks are unlikely.
When analyzing the results of the acoustic exposure modeling to
provide an estimate of effects, it is important to understand that
there are limitations to the ecological data (diving behavior,
migration or movement patterns and population dynamics) used in the
model, and that the model results must be interpreted within the
context of a given species' ecology.
When reviewing the acoustic exposure modeling results, it is also
important to understand that the estimates of marine mammal sound
exposures are presented with consideration of standard protective
measure operating procedures. The ROP along with monitoring and
mitigation measures for the Keyport Range Complex RDT&E activities,
including detection of marine mammals, protective measures such as
stand off distances and delaying or halting activities, and power down
procedures if marine mammals are detected within one of the exclusion
zones, are provided below.
Because of the time delay between pings, an animal encountering the
sonar will accumulate energy for only a few sonar pings over the course
of a few minutes. Therefore, exposure to sonar would be a short-term
event, minimizing any single animal's exposure to sound levels
approaching the harassment thresholds.
Effects on Marine Mammal Habitat
The proposed extended area for the Keyport Range Site is also
critical habitat of the Southern Resident killer whales. The current
Keyport Range Site is outside the critical habitat area. There are no
other areas within the Keyport Range Complex with extensions 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 Keyport Range Complex RDT&E and range extension
activities contain a detailed discussion of the potential effects to
fish from active acoustic sources. Below is a summary of conclusions
regarding those effects.
Effects on Fish From Active Acoustic Sources
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
[[Page 32293]]
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 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 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.
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.''
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 underwater active acoustic sources 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 active acoustic sources 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 active acoustic sources 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 Active Acoustic Sources, Surface
Operations and Other Activities
Current protective measures known as the ROP employed by the NAVSEA
NUWC Keyport include applicable training of personnel and
implementation of activity specific procedures resulting in
minimization and/or avoidance of interactions with protected resources
and are provided below.
(1) Range activities shall be conducted in such a way as to ensure
marine mammals are not harassed or harmed by human-caused events.
(2) Marine mammal observers are on board ship during range
activities. All range personnel shall be trained in marine mammal
recognition. Marine mammal observer training is normally conducted by
qualified organizations such as NOAA/National Marine Mammal Lab (NMML)
on an as needed basis.
(3) Vessels on a range use safety lookouts during all hours of
range activities. Lookout duties include looking for any and all
objects in the water, including marine mammals. These lookouts are not
necessarily looking only for marine mammals. They have other duties
while aboard. All sightings are reported to the Range Officer in charge
of overseeing the activity.
(4) Visual surveillance shall be accomplished just prior to all in-
water exercises. This surveillance shall ensure that no marine mammals
are visible within the boundaries of the area within which the test
unit is expected to be operating. Surveillance shall include, as a
minimum, monitoring from all participating surface craft and, where
available, adjacent shore sites.
(5) The Navy shall postpone activities until cetaceans (whales,
dolphins, and porpoises) leave the project area. When cetaceans have
been sighted in an area, all range participants increase vigilance and
take reasonable and practicable actions to avoid collisions and
activities that may result in close interaction of naval assets and
marine mammals. Actions may include changing speed and/or direction and
are dictated by environmental and other conditions (e.g., safety,
weather).
(6) An ``exclusion zone'' shall be established and surveillance
will be conducted to ensure that there are no marine mammals within
this exclusion zone prior to the commencement of each in-water
exercise. For cetaceans (whales, dolphins, and porpoises), the
exclusion zone must be at least as large as the entire area within
which the test unit may operate, and must extend at least 1,000 yards
(914.4 m) from the intended track of the test unit. For pinnipeds, the
exclusion zone extends out 100 yards (91 m) from the intended track of
the test unit.
[[Page 32294]]
(7) Range craft shall not approach within 100 yards (91 m) of
marine mammals and shall be followed to the extent practicable
considering human and vessel safety priorities. All Navy vessels and
aircraft, including helicopters, are expected to comply with this
directive. This includes marine mammals ``hauled-out'' on islands,
rocks, and other areas such as buoys.
(8) Passive acoustic monitoring shall be utilized to detect marine
mammals in the area before and during activities, especially when
visibility is reduced.
(9) Procedures for reporting marine mammal sightings on the NAVSEA
NUWC Keyport Range Complex shall be promulgated, and sightings shall be
entered into the Range Operating System and forwarded to NOAA/NMML
Platforms of Opportunity Program.
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,
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 led 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 incidental take authorization (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
[[Page 32295]]
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 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) 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.
(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 NAVSEA NUWC Keyport Range Complex RDT&E and range
extension activities have been worked out between NMFS and the Navy.
Keyport will conduct two special surveys per year to monitor HFAS and
MFAS respectively. This will occur at the DBRC Range site. This will
include visual surveys composed of vessel, shore monitoring and passive
acoustic monitoring. Marine mammal observers may be on range craft and/
or on shore side. 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 (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 is proposed to be used so that
the detection and observation of marine animals is maximized.
Monitoring methods proposed during mission activity events in the
NAVSEA NUWC Keyport Range Complex Study Area include a combination of
the following research elements that would be used to collect data for
comprehensive assessment:
Visual Surveys--Vessel, Shore-based, and Aerial (as
applicable)
Passive Acoustic Monitoring (PAM)
Marine Mammal Observers (MMOs) on Range craft
Visual Surveys
Visual surveys of marine animals can provide detailed information
about their 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. Shore-based (for inland waters),
vessel and aerial (as applicable) surveys may be conducted from shore
support, range craft, Navy vessels, or contracted vessels. Visual
surveys will be conducted during NAVSEA NUWC Keyport range events which
are identified as being able to provide 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 surface (e.g. in the water
column) as compared to aerial surveys (DoN, 2008a; Slooten et al.,
2004).
NAVSEA NUWC Keyport will conduct two special surveys per year to
monitor HFAS and MFAS respectively. This will occur at the DBRC Range
site. The determination to monitor in the DBRC area includes the
following reasoning: (1) It would provide the highest amount of
activity; (2) it is a controlled environment; (3) permanently bottom
mounted monitoring hydrophones are in place; (4) most likely
environment to get accurate data; and (5) conducive to excellent shore
side observation.
For specified events, shore-based and vessel surveys will be used 1
day prior to and 1-2 days post activity. The variation in the number of
days after allows for the detection of animals that gradually return to
an area, if they indeed do change their distribution in response to the
associated events. DBRC is a small area and animals are likely to
return more quickly than if the test were in open ocean.
Surveys will include the range site with special emphasis given to
the particular path of the test run. Passive acoustic system
(hydrophone or towed array) would be used to determine if marine
mammals are in the area before and/or after the event. When conducting
a particular survey, the survey team will collect: (1) Species
identification and group size; (2) location and relative distance from
the acoustic source(s); (3) the behavior of marine mammals, including
standard environmental and oceanographic parameters; (4) date, time and
visual conditions associated with each observation; (5) direction of
travel relative to the active acoustic source; and (6) duration of the
observation. Animal sightings and relative distance from a particular
active acoustic source will be used post-survey to determine potential
received energy (dB re 1 micro Pa-sec). This data will be used, post-
survey, to estimate the number of marine mammals exposed to different
received levels (energy based on distance to the source, bathymetry,
oceanographic conditions and the type and power of the acoustic source)
and their corresponding behavior.
Although photo-identification studies are not typically a component
of Navy RDT&E activity monitoring surveys, the Navy supports using the
contracted platforms to obtain opportunistic data collection.
Therefore, absent classification issues any unclassified digital
photographs, if taken, of marine mammals during visual surveys will be
[[Page 32296]]
provided to local researchers for their regional research if requested.
1. Shore-Based Surveys
A large number of test events in the Keyport Range complex are
conducted in inland waters allowing for excellent shore based
surveillance opportunities. When practicable, for test events planned
adjacent to nearshore areas, where there are elevated topography or
coastal structures, shore-based visual survey methods will be
implemented using binoculars or theodolite. These methods have been
proven valuable in similar monitoring studies such as ATOC and others
(Frankel and Clark, 1998; Clark and Altman, 2006).
2. Vessel Surveys
Keyport Range Complex activities conducted in the inland waters are
supported both from the shore (described above) and from range craft.
The primary purpose of surveys performed from these range craft 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. 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.
Passive Acoustic Monitoring
There are both benefits and limitations to passive acoustic
monitoring (Mellinger et al., 2007). Passive acoustic monitoring (PAM)
allows detection of marine mammals that vocalize but 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
only be calling only under certain conditions (Mellinger, 2007; ONR,
2007). The Keyport Range Complex study area has advanced features which
allow for passive acoustic monitoring. These hydrophones are both
permanently bottom mounted, towed or over-the-side. Subject matter
experts are available for detection and identification of species type.
Marine Mammal Observer on Navy Vessels
All Keyport Range Complex operators are trained by NOAA in marine
mammal identification. Additional use of civilian biologists as Marine
Mammal Observers (MMOs) aboard range craft and Navy vessels may 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 who are Navy biologists or
contracted observers. These civilian MMOs will be placed alongside
existing Navy marine observers during a sub-set of Keyport Range
Complex RDT&E activities. This can only be done on certain vessels and
observers may be required to have security clearance. NUWC Keyport may
also use MMOs on range craft during test events being monitored. MMOs
will not be placed aboard Navy platforms for every Navy testing event,
but during specifically identified opportunities deemed appropriate for
data collection efforts. The events selected for MMO participation will
take into account safety, logistics, and operational concerns. 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 Keyport
Range Complex RDT&E activities. The MMOs will not be part of the Navy's
formal vessel reporting chain of command during their data collection
efforts, and Navy marine observers will follow the appropriate 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 Navy
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
MMOs 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
Navy 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.
In addition, the Navy is developing an Integrated Comprehensive
Monitoring Program (ICMP) for marine species to assess the effects of
Keyport Range Complex RDT&E activities on marine species and
investigate population trends in marine species distribution and
abundance in locations where Keyport Range Complex RDT&E activities
regularly occur. As part of the ICMP, knowledge gained from other Navy
MMO monitored events will be incorporated into NUWC Keyport monitoring/
mitigations as part of the adaptive management approach.
The ICMP will provide the overarching coordination that will
support compilation of data from range-specific monitoring plans (e.g.,
Keyport Range Complex plan) as well as Navy funded research and
development (R&D) studies. The ICMP will coordinate the monitoring
program's progress toward 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;
[[Page 32297]]
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 NAVSEA NUWC Keyport Range Complex 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 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
this proposed Keyport Range Complex rule.
Guidelines for prioritizing monitoring projects
If, as a result of the Navy-NMFS 2011 Monitoring 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
recordkeeping 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 Keyport Range Complex 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 Keyport Range Complex Study Area or other locations).
Results from specific stranding investigations (either
from the Keyport Range Complex Study Area or other locations, and
involving coincident Keyport Range Complex 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 and 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 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 monitoring 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.
Notification of Injured or Dead Marine Mammals
Navy personnel will ensure through proper chain of command 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 Keyport
Range Complex RDT&E activities utilizing active acoustic sources. 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:
[[Page 32298]]
The estimated number of hours of sonar and other
operations involving active acoustic sources, 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)
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.
Keyport Range Complex 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 test activities involving active acoustic sources for which
annual reports are required as described above. This report will be
submitted at the end of the fourth year of the rule (anticipated to be
December 2013), covering activities that have occurred through June 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.), 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 planned RDT&E activities the Navy would conduct within
the proposed NAVSEA NUWC Keyport Range Complex Extension. The acoustic
sources proposed to be used in the NAVSEA NUWC Keyport Range Complex
Extension are low intensity and total proposed sonar operation hours
are under 1,570 hours. Taking the above into account, along with the
fact that NMFS anticipates no mortalities and injuries to result from
the action, the fact that there are no specific areas of reproductive
importance for marine mammals recognized within the Keyport Range
Complex Extension study area, the sections discussed below, and
dependent upon the implementation of the proposed mitigation measures,
NMFS has determined that Navy RDT&E activities utilizing underwater
acoustic sources will have a negligible impact on the affected marine
mammal species and stocks present in the proposed action 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 some extent. 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 Keyport
Range Complex application involves mid-frequency and high frequency
active sonar operations shown in Table 2, and none of the tests would
involve powerful tactical sonar such as the 53C series MFAS. Therefore,
any disturbance to marine mammals resulting from MFAS and HFAS in the
proposed Keyport Range Complex RDT&E activities is expected to be
significantly less in terms of severity when compared to major sonar
exercises (e.g., AFAST, HRC, SOCAL). 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, 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 Keyport Range Complex 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 may not have been 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
[[Page 32299]]
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 that fall into the category of
harassment could range in severity. By definition, the takes by Level B
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. Different sonar testing may not occur
simultaneously. Some of the marine mammals in the Keyport Range Complex
Study Area are residents and others would not likely remain in the same
area for successive days, it is unlikely that animals would be exposed
to HFAS/MFAS 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
operations. 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 dB 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).
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 dB 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.
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. Masking effects from HFAS/MFAS
are expected to be minimal. If masking or communication impairment were
to occur briefly, it would be in the frequency range of MFAS, which
overlaps with some marine mammal vocalizations; however, it would
likely not mask the entirety of any particular vocalization or
communication series because the 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 no marine mammal would be taken by
Level A harassment (injury, PTS included) or mortality due to the low
intensity of the active sound sources being used.
Based on the aforementioned assessment, NMFS preliminarily
determines that there would be the following number of takes: 11,283
harbor porpoises, 44 northern fur seals, 114 California sea lions, 14
northern elephant seals, and 5,569 (5,468 Washington Inland Waters
stock and 101 Oregon/Washington Coastal stock) harbor seals at Level B
harassment (TTS and sub-TTS) as a result of the proposed Keyport Range
Complex RDT&E sonar testing activities. These numbers do not represent
the number of individuals that would be taken, since it's most likely
that many individual marine mammals would be taken multiple times.
However, under the worst case scenario that each animal is taken only
once, it is expected that these take numbers represent approximately
29.89%, 0.01%, 0.05%, 0.01%, 37.42%, and 0.41% of the Oregon/Washington
Coastal stock harbor porpoises, Eastern Pacific stock northern fur
seals, U.S. stock California sea lions, California breeding stock
northern elephant seals, Washington Inland Waters stock harbor seals,
and Oregon/Washington Coastal stock harbor seals, respectively, in the
vicinity of the proposed Keyport Range Complex Study Area (calculation
based
[[Page 32300]]
on NMFS 2007 U.S. Pacific Marine Mammal Stock Assessments and 2007 U.S.
Alaska Marine Mammal Stock Assessments).
No Level A take (injury, PTS included) or mortality would occur as
the result of the proposed RDT&E and range extension activities for the
Keyport Range Complex.
Based on these analyses, NMFS has preliminarily determined that the
total taking over the 5-year period of the regulations and subsequent
LOAs from the Navy's NAVSEA NUWCX Keyport Range Complex RDT&E and range
extension activities will have a negligible impact on the marine mammal
species and stocks present in the Keyport Range Complex 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
Keyport Range Complex 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 eight marine mammal species/stocks over which NMFS has
jurisdiction that are listed as endangered or threatened under the ESA
that could occur in the NAVSEA NUWCX Keyport Range Complex study area:
Blue whales, fin whales, sei whales, humpback whales, North Pacific
right whales, sperm whales, Southern Resident killer whales, and
Steller sea lions. The Navy has begun consultation with NMFS pursuant
to section 7 of the ESA, and NMFS will also consult internally on the
issuance of regulations and LOAs under section 101(a)(5)(A) of the MMPA
for mission activities in the Keyport Range Complex study area.
Consultation will be concluded prior to a determination on the issuance
of a final rule and an LOAs.
NEPA
The Navy is preparing an Environmental Impact Statement (EIS) for
the proposed Keyport Range Complex RDT&E and range extension
activities. A draft EIS was released for public comment from September
12-October 27, 2008 and is available at http://www-keyport.kpt.nuwc.navy.mil. 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 Keyport Range
Complex 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 NAVSEA NUWC Keyport
Range Complex RDT&E and range extension activities utilizing active
acoustic sources in the NAVSEA NUWC Keyport Range Complex 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
requirements 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 active acoustic sources during
RDT&E activities that are only conducted by and for 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 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: June 30, 2009.
James W. Balsiger,
Acting Assistant Administrator for Fisheries, National Marine Fisheries
Service.
For reasons set forth in the preamble, 50 CFR part 218 is proposed
to be amended as follows.
PART 218--REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE
MAMMALS
1. The authority citation for part 218 continues to read as
follows:
Authority: 16 U.S.C. 1361 et seq.
2. Subpart S is added to part 218 to read as follows:
Subpart S--Taking Marine Mammals Incidental to U.S. Navy Research,
Development, Test, and Evaluation Activities in the Naval Sea System
Command Naval Undersea Warfare Center Keyport Range Complex and the
Associated Proposed Extensions Study Area
Sec.
218.170 Specified activity and specified geographical area.
218.171 Permissible methods of taking.
218.172 Prohibitions.
218.173 Mitigation.
218.174 Requirements for monitoring and reporting.
[[Page 32301]]
218.175 Applications for Letters of Authorization.
218.176 Letters of Authorization.
218.177 Renewal of Letters of Authorization and adaptive management.
218.178 Modifications to Letters of Authorization.
Subpart S--Taking Marine Mammals Incidental to U.S. Navy Research,
Development, Test, and Evaluation Activities in the Naval Sea
System Command (NAVSEA) Naval Undersea Warfare Center (NUWC)
Keyport Range Complex and the Associated Proposed Extensions Study
Area
Sec. 218.170 Specified activity and specified geographical area.
(a) Regulations in this subpart apply only to the U.S. Navy for the
taking of marine mammals that occur 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) These regulations apply only to the taking of marine mammals by
the Navy that occurs within the Keyport Range Complex Action Area,
which includes the extended Keyport Range Site, the extended DBRC Range
Complex (DBRC) Site, and the extended Quinault Underwater Tracking
Range (QUTR) Site, as presented in the Navy's LOA application. The
NAVSEA NUWC Keyport Range Complex is divided into open ocean/offshore
areas and in-shore areas:
(1) Open Ocean Area--air, surface, and subsurface areas of the
NAVSEA NUWC Keyport Range Complex Extension that lie outside of 12
nautical miles (nm) from land.
(2) Offshore Area--air, surface, and subsurface ocean areas within
12 nm of the Pacific Coast.
(3) In-shore--air, surface, and subsurface areas within the Puget
Sound, Port Orchard Reach, Hood Canal, and Dabob Bay.
(c) These regulations apply only to the taking of marine mammals by
the Navy if it occurs incidental to the following activities within the
designated amounts of use:
(1) Range Activities Using Active Acoustic Devices:
(i) General range tracking: Narrow frequency output between 10 to
100 kHz with source levels (SL) between 195-203 dB re 1 microPa-m.
(ii) UUV Tracking Systems: Operating frequency of 10 to 100 kHz
with SLs less than 195 dB re 1 microPa-m at all range sites.
(iii) Torpedo Sonars: Operating frequency from 10 to 100 kHz with
SL under 233 dB re 1 microPa-m.
(iv) Range Targets and Special Test Systems: 5 to 100 kHz frequency
range with a SL less than 195 dB re 1 microPa-m at the Keyport Range
Site and SL less than 238 dB re microPa-m at the DBRC and QUTR sites.
(v) Special Sonars: Frequencies vary from 100 to 2,500 kHz with SL
less than 235 dB re 1 microPa-m.
(vi) Sonobuoys and Helicopter Dipping Sonar: Operate at frequencies
of 2 to 20 kHz with SLs of less than 225 dB re 1 microPa-m.
(vii) Side Scan Sonar: Multiple frequencies typically at 100 to 700
kHz with SLs less than 235 dB re 1 microPa-m.
(viii) Other Acoustic Sources:
(A) Acoustic Modems: Emit pulses at frequencies from 10 to 300 kHz
with SLs less than 210 dB re 1 microPa-m.
(B) Target Simulators: Operate at frequencies of 100 Hz to 10 kHz
at source levels of less than 170 dB re 1 microPa-m.
(C) Aids to Navigation: Operate at frequencies of 70 to 80 kHz at
SLs less than 210 dB re 1 microPa-m.
(D) Subbottom Profilers: Operate at 2 to 7 kHz at SLs less than 210
dB re 1 microPa-m, and 35 to 45 kHz at SLs less than 220 dB re 1
microPa-m.
(E) Surface Vessels, Submarines, Torpedoes, and Other UUVs:
Acoustic energy from engines usually from 50 Hz to 10 kHz at SLs less
than 170 dB re 1 microPa-m.
(2) Increased Tempo and Activities due to Range Extension: Proposed
annual range activities and operations as listed in the following
table:
[[Page 32302]]
[GRAPHIC] [TIFF OMITTED] TP07JY09.011
Sec. 218.171 Permissible methods of taking.
(a) Under Letters of Authorization issued pursuant to Sec. Sec.
216.106 and 218.176 of this chapter, the Holder of the Letter of
Authorization may incidentally, but not intentionally, take marine
mammals within the area described in Sec. 218.170(b), provided the
activity is in compliance with all terms, conditions, and requirements
of these regulations and the appropriate Letter of Authorization.
(b) The activities identified in Sec. 218.170(c) must be conducted
in a manner that minimizes, to the greatest extent practicable, any
adverse impacts on marine mammals and their habitat.
(c) The incidental take of marine mammals under the activities
identified in Sec. 218.170(c) is limited to the following species, by
Level B harassment only and the indicated number of times:
(1) Harbor porpoise (Phocoena phocoena)--56,415 (an average of
11,283 annually),
(2) Northern fur seal (Callorhinus ursinus)--220 (an average of 44
annually);
(3) California sea lion (Zalophus californianus)--570 (an average
of 114 annually);
(4) Northern elephant seal (Mirounga angustirostris)--70 (an
average of 14 annually);
(5) Harbor seal (Phoca vitulina richardsi) (Washington Inland
Waters stock)--27,340 (an average of 5,468 annually); and
(6) Harbor seal (P. v. richardsi) (Oregon/Washington Coastal
stock)--505 (an average of 101 annually);
Sec. 218.172 Prohibitions.
Notwithstanding takings contemplated in Sec. 218.171 and
authorized by a Letter of Authorization issued under Sec. 216.106 of
this chapter and Sec. 218.176, no person in connection with the
activities described in Sec. 218.170 may:
(a) Take any marine mammal not specified in Sec. 218.171(b);
(b) Take any marine mammal specified in Sec. 218.171(b) other than
by incidental take as specified in Sec. 218.171 (b);
(c) Take a marine mammal specified in Sec. 218.171(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. 218.176.
Sec. 218.173 Mitigation.
When conducting RDT&E activities identified in Sec. 218.170(c),
the mitigation measures contained in this subpart and subsequent
Letters of Authorization issued under Sec. 216.106 of this chapter and
Sec. 218.176 must be implemented. These mitigation measures include,
but are not limited to:
(a) Marine mammal observers training:
(1) All range personnel shall be trained in marine mammal
recognition.
(2) Marine mammal observer training shall be conducted by qualified
organizations approved by NMFS.
(b) Lookouts onboard vessels:
(1) Vessels on a range shall use lookouts during all hours of range
activities.
(2) Lookout duties include looking for marine mammals.
(3) All sightings of marine mammals shall be reported to the Range
Officer in charge of overseeing the activity.
(c) Visual surveillance shall be conducted just prior to all in-
water exercises.
[[Page 32303]]
(1) Surveillance shall include, as a minimum, monitoring from all
participating surface craft and, where available, adjacent shore sites.
(2) When cetaceans have been sighted in the vicinity of the
operation, all range participants increase vigilance and take
reasonable and practicable actions to avoid collisions and activities
that may result in close interaction of naval assets and marine
mammals.
(3) Actions may include changing speed and/or direction, subject to
environmental and other conditions (e.g., safety, weather).
(d) An ``exclusion zone'' shall be established and surveillance
will be conducted to ensure that there are no marine mammals within
this exclusion zone prior to the commencement of each in-water
exercise.
(1) For cetaceans, the exclusion zone shall extend out 1,000 yards
(914.4 m) from the intended track of the test unit.
(2) For pinnipeds, the exclusion zone shall extend out 100 yards
(91 m) from the intended track of the test unit.
(e) Range craft shall not approach within 100 yards (91 m) of
marine mammals, to the extent practicable considering human and vessel
safety priorities. This includes marine mammals ``hauled-out'' on
islands, rocks, and other areas such as buoys.
(f) In the event of a collision between a Navy vessel and a marine
mammal, NUWC Keyport activities shall notify immediately the Navy chain
of Command, which shall notify NMFS immediately.
(g) Passive acoustic monitoring shall be utilized to detect marine
mammals in the area before and during activities.
(h) Procedures for reporting marine mammal sightings on the NAVSEA
NUWC Keyport Range Complex shall be promulgated, and sightings shall be
entered into the Range Operating System and forwarded to NOAA/NMML
Platforms of Opportunity Program.
Sec. 218.174 Requirements for monitoring and reporting.
(a) The Holder of the Letter of Authorization issued pursuant to
Sec. 216.106 of this chapter and Sec. 218.176 for activities
described in Sec. 218.170(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. 218.170(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. 218.171(c).
(c) The Navy must conduct all monitoring and required reporting
under the Letter of Authorization, including abiding by the NAVSEA NUWC
Keyport Range Complex Monitoring Plan, which is incorporated herein by
reference, and which requires the Navy to implement, at a minimum, the
monitoring activities summarized below:
(1) Visual Surveys:
(i) The Holder of this Authorization shall conduct a minimum of 2
special visual surveys per year to monitor HFAS and MFAS respectively
at the DBRC Range site.
(ii) For specified events, shore-based and vessel surveys shall be
used 1 day prior to and 1-2 days post activity.
(A) Shore-based Surveys:
(1) Shore-based monitors shall observe test events that are planned
in advance to occur adjacent to near shore areas where there are
elevated topography or coastal structures, and shall use binoculars or
theodolite to augment other visual survey methods.
(2) Shore-based surveys of the test 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 and the
information shall be transmitted immediately to NMFS through the
appropriate chain of command.
(B) Vessel-based Surveys:
(1) Vessel-based surveys shall be designed to maximize detections
of marine mammals near mission activity event.
(2) Post-analysis shall focus on how the location, speed and vector
of the range craft and the location and direction of the sonar source
(e.g., Navy surface vessel) relates to the animal.
(3) Any other vessels or aircraft observed in the area shall also
be documented.
(iii) Surveys shall include the range site with special emphasis
given to the particular path of the test run. When conducting a
particular survey, the survey team shall collect the following
information.
(A) Species identification and group size;
(B) Location and relative distance from the acoustic source(s);
(C) The behavior of marine mammals including standard environmental
and oceanographic parameters;
(D) Date, time and visual conditions associated with each
observation;
(E) Direction of travel relative to the active acoustic source; and
(F) Duration of the observation.
(iv) Animal sightings and relative distance from a particular
active acoustic source shall be used post-survey to determine potential
received energy (dB re 1 micro Pa-sec). This data shall be used, post-
survey, to estimate the number of marine mammals exposed to different
received levels (energy based on distance to the source, bathymetry,
oceanographic conditions and the type and power of the acoustic source)
and their corresponding behavior.
(2) Passive Acoustic Monitoring (PAM):
(i) The Navy shall deploy a hydrophone array in the Keyport Range
Complex Study Area for PAM.
(ii) The array shall be utilized during the two special monitoring
surveys in DBRC as described in Sec. 218.174(c)(1)(i).
(iii) The array shall have the capability of detecting low-
frequency vocalizations (<1,000 Hz) for baleen whales and relatively
high frequency (up to 30 kHz) for odontocetes.
(iv) Acoustic data collected from the PAM shall be used to detect
acoustically active marine mammals as appropriate.
(3) Marine Mammal Observers on range craft or Navy vessels:
(i) Navy Marine mammal observers (NMMOs) may be placed on a range
craft or Navy platform during the event being monitored.
(ii) The NMMO must possess expertise in species identification of
regional marine mammal species and experience collecting behavioral
data.
(iii) NMMOs may be placed alongside existing lookouts during the
two specified monitoring events as described in Sec. 218.174(c)(1)(i).
(iv) NMMOs shall inform the lookouts of any marine mammal sighting
so that appropriate action may be taken by the chain of command. NMMOs
shall schedule their daily observations to duplicate the lookouts'
schedule.
(v) NMMOs shall observe from the same height above water as the
lookouts, and they shall collect the same data collected by lookouts
listed in Sec. 218.174(c)(1)(iii).
(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.
[[Page 32304]]
(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 NAVSEA NUWC
Keyport Range Complex Extension and across range complexes.
(e) Notification of Injured or Dead Marine Mammals--Navy personnel
shall 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 training exercise utilizing underwater explosive
detonations. The Navy shall provide NMFS with species or description of
the animal(s), the condition of the animal(s) (including carcass
condition if the animal is dead), location, time of first discovery,
observed behaviors (if alive), and photo or video (if available).
(f) Annual Keyport Range Complex Monitoring Plan Report--The Navy
shall submit a report annually on December 1 describing the
implementation and results (through September 1 of the same year) of
the Keyport Range Complex Monitoring Plan. Data collection methods will
be standardized across range complexes to allow for comparison in
different geographic locations. Although additional information will
also be gathered, the NMMOs collecting marine mammal data pursuant to
the Keyport Range Complex Monitoring Plan shall, at a minimum, provide
the same marine mammal observation data required in Sec. 218.174(c).
The Keyport Range Complex Monitoring Plan Report may be provided to
NMFS within a larger report that includes the required Monitoring Plan
Reports from Keyport Range Complex and multiple range complexes.
(g) Keyport Range Complex 5-yr Comprehensive Report--The Navy shall
submit to NMFS a draft comprehensive report that analyzes and
summarizes all of the multi-year marine mammal information gathered
during tests involving active acoustic sources for which individual
reports are required in Sec. 218.174(d-f). This report will be
submitted at the end of the fourth year of the rule (June 2013),
covering activities that have occurred through September 1, 2013.
(h) The Navy shall respond to NMFS comments and requests for
additional information or clarification on the Keyport Range Complex
Extension Comprehensive Report, the Annual Keyport Range Complex
Monitoring Plan Report (or the multi-Range Complex Annual Monitoring
Report, if that is how the Navy chooses to submit the information) 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. 218.175 Applications for Letters of Authorization.
To incidentally take marine mammals pursuant to these regulations
for the activities identified in Sec. 218.170(c), the U.S. Navy must
apply for and obtain either an initial Letter of Authorization in
accordance with Sec. 218.176 or a renewal under Sec. 218.177.
Sec. 218.176 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. 218.177.
(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. 218.177 Renewal of Letters of Authorization and adaptive
management.
(a) A Letter of Authorization issued under Sec. 216.106 and Sec.
218.176 for the activity identified in Sec. 218.170(c) will be renewed
annually upon:
(1) Notification to NMFS that the activity described in the
application submitted under Sec. 218.175 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.
218.174(b); and
(3) A determination by the NMFS that the mitigation, monitoring and
reporting measures required under Sec. 218.173 and the Letter of
Authorization issued under Sec. Sec. 216.106 and 218.176, 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 218.177 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. Public
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
(either from Keyport Range Complex Study Area or other locations).
(2) Findings of the Monitoring Workshop that the Navy will convene
in 2011 (Sec. 218.174(i)).
(3) Compiled results of Navy funded research and development (R&D)
studies (presented pursuant to the ICMP (Sec. 218.174(d)).
(4) Results from specific stranding investigations (either from the
Keyport Range Complex Study Area or other locations).
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(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. 218.178 Modifications to Letters of Authorization.
(a) Except as provided in paragraph (b) of this section and Sec.
218.177(d), 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. 218.176 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.
218.177, 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. 218.171(b), a Letter of
Authorization issued pursuant to Sec. 216.106 of this chapter and
Sec. 218.176 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. E9-15839 Filed 6-30-09; 4:15 pm]
BILLING CODE 3510-22-P