Takes of Marine Mammals Incidental to Specified Activities; U.S. Navy Civilian Port Defense Activities at the Ports of Los Angeles/Long Beach, California, 53657-53689 [2015-21911]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 80, Number 172 (Friday, September 4, 2015)]
[Notices]
[Pages 53657-53689]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-21911]



[[Page 53657]]

Vol. 80

Friday,

No. 172

September 4, 2015

Part III





Department of Commerce





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 National Oceanic and Atmospheric Administration





 Takes of Marine Mammals Incidental to Specified Activities; U.S. Navy 
Civilian Port Defense Activities at the Ports of Los Angeles/Long 
Beach, California; Notice

Federal Register / Vol. 80 , No. 172 / Friday, September 4, 2015 / 
Notices

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XE131


Takes of Marine Mammals Incidental to Specified Activities; U.S. 
Navy Civilian Port Defense Activities at the Ports of Los Angeles/Long 
Beach, California

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

ACTION: Notice; proposed incidental harassment authorization; request 
for comments.

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SUMMARY: NMFS has received a request from the U.S. Navy (Navy) for an 
Incidental Harassment Authorization (IHA) to take marine mammals, by 
harassment, incidental to Civilian Port defense activities within and 
near the Ports of Los Angeles and Long Beach from October through 
November 2015. Pursuant to the Marine Mammal Protection Act (MMPA), 
NMFS is requesting comments on its proposal to issue an IHA to the Navy 
to incidentally take, by Level B harassment only, marine mammals during 
the specified activity.

DATES: Comments and information must be received no later than October 
5, 2015.

ADDRESSES: Comments on the Navy's IHA application (the application) 
should be addressed to Jolie Harrison, Chief, Permits and Conservation 
Division, Office of Protected Resources, National Marine Fisheries 
Service, 1315 East-West Highway, Silver Spring, MD 20910. The mailbox 
address for providing email comments is itp.fiorentino@noaa.gov. 
Comments sent via email, including all attachments, must not exceed a 
25-megabyte file size. NMFS is not responsible for comments sent to 
addresses other than those provided here.
    Instructions: All comments received are a part of the public record 
and will generally be posted to https://www.nmfs.noaa.gov/pr/permits/incidental/ 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.
    An electronic copy of the application may be obtained by writing to 
the address specified above, telephoning the contact listed below (see 
FOR FURTHER INFORMATION CONTACT), or visiting the Internet at: https://www.nmfs.noaa.gov/pr/permits/incidental/. Documents cited in this 
notice may also be viewed, by appointment, during regular business 
hours, at the aforementioned address.
    The Navy is also preparing an Environmental Assessment (EA) in 
accordance with the National Environmental Policy Act (NEPA), to 
evaluate all components of the proposed Civilian Port Defense training 
activities. NMFS intends to adopt the Navy's EA, if adequate and 
appropriate. Currently, we believe that the adoption of the Navy's EA 
will allow NMFS to meet its responsibilities under NEPA for the 
issuance of an IHA to the Navy for Civilian Port Defense activities at 
the Ports of Los Angeles and Long Beach Harbor. If necessary, however, 
NMFS will supplement the existing analysis to ensure that we comply 
with NEPA prior to the issuance of the final IHA.

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

SUPPLEMENTARY INFORMATION:

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce to allow, upon request, the 
incidental, but not intentional, taking of small numbers of marine 
mammals by U.S. citizens who engage in a specified activity (other than 
commercial fishing) within a specified geographical region if certain 
findings are made and either regulations are issued or, if the taking 
is limited to harassment, a notice of a proposed authorization is 
provided to the public for review.
    An authorization for incidental takings shall be granted if NMFS 
finds that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103 
as ``an impact resulting from the specified activity that cannot be 
reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.''
    The National Defense Authorization Act of 2004 (NDAA) (Pub. L. 108-
136) removed the ``small numbers'' and ``specified geographical 
region'' limitations indicated above and amended the definition of 
``harassment'' as it applies to a ``military readiness activity'' to 
read as follows (Section 3(18)(B) of the MMPA): (i) Any act that 
injures or has the significant potential to injure a marine mammal or 
marine mammal stock in the wild [Level A Harassment]; or (ii) Any act 
that disturbs or is likely to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of natural behavioral patterns, 
to a point where such behavioral patterns are abandoned or 
significantly altered [Level B Harassment].
    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: Any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild [Level A harassment]; or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering [Level B harassment].

Summary of Request

    On April 16, 2015, NMFS received an application from the Navy 
requesting an IHA for the taking of marine mammals incidental to 
Civilian Port Defense activities at the Ports of Los Angeles and Long 
Beach, California from October through November, 2015.
    The Study Area includes the waters within and near the Ports of Los 
Angeles and Long Beach, California. Since the Ports of Los Angeles and 
Long Beach are adjacent and are both encompassed within the larger 
proposed action area (Study Area) they will be described collectively 
as Los Angeles/Long Beach (see Figure 2-1 of the application for a map 
of the Study Area). These activities are classified as military 
readiness activities. Marine mammals present in the Study Area may be 
exposed to sound from active acoustic sources (sonar). The Navy is 
requesting authorization to take 7 marine mammal species by Level B 
harassment (behavioral). No injurious takes (Level A harassment) of 
marine mammals are predicted and, therefore, none are being authorized.

Description of the Specified Activity

    Civilian Port Defense activities are naval mine warfare exercises 
conducted in support of maritime homeland defense, per the Maritime 
Operational Threat Response Plan. These activities are conducted in 
conjunction with other federal agencies, principally the Department of 
Homeland Security. The

[[Page 53659]]

three pillars of Mine Warfare include airborne (helicopter), surface 
(ship and unmanned vehicles), and undersea (divers, marine mammal 
systems, and unmanned vehicles), all of which are used in order to 
ensure that strategic U.S. ports are cleared of mine threats. Civilian 
Port Defense events are conducted in ports or major surrounding 
waterways, within the shipping lanes, and seaward to the 300 feet (ft, 
91 meters [m]) depth contour. The events employ the use of various mine 
detection sensors, some of which utilize active acoustics for detection 
of mines and mine-like objects in and around various ports. Assets used 
during Civilian Port Defense training include up to four unmanned 
underwater vehicles, marine mammal systems, up to two helicopters 
operating (two to four hours) at altitudes as low as 75 to 100 ft (23 
to 31 m), explosive ordnance disposal platoons, a Littoral Combat Ship 
or Landing Dock Platform and AVENGER class ships. The AVENGER is a 
surface mine countermeasure vessel specifically outfitted for mine 
countermeasure capability. The proposed Civilian Port Defense 
activities for Los Angeles/Long Beach include the use of up to 20 
bottom placed non explosive mine training shapes. Mine shapes may be 
retrieved by Navy divers, typically explosive ordnance disposal 
personnel, and may be brought to beach side locations to ensure that 
the neutralization measures are effective and the shapes are secured. 
The final step to the beach side activity is the intelligence gathering 
and identifying how the mine works, disassembling it or neutralizing 
it. The entire training event takes place over multiple weeks utilizing 
a variety of assets and scenarios. The following descriptions detail 
the possible range of activities which could take place during a 
Civilian Port Defense training event. This is all inclusive and many of 
these activities are not included within the analysis of this specific 
event. Mine detection including towed or hull mounted sources would be 
the only portion of this event which we are proposing authorization.

Mine Detection Systems

    Mine detection systems are used to locate, classify, and map 
suspected mines (Figure 1-1 of the application). Once located, the 
mines can either be neutralized or avoided. These systems are 
specialized to either locate mines on the surface, in the water column, 
or on the sea floor.
     Towed or Hull-Mounted Mine Detection Systems. These 
detection systems use acoustic and laser or video sensors to locate and 
classify suspect mines. Helicopters, ships, and unmanned vehicles are 
used with towed systems, which can rapidly assess large areas.
     Unmanned/Remotely Operated Vehicles. These vehicles use 
acoustic and video or lasers systems to locate and classify mines. 
Unmanned/remotely operated vehicles provide mine warfare capabilities 
in nearshore littoral areas, surf zones, ports, and channels.
     Airborne Laser Mine Detection Systems. Airborne laser 
detection systems work in concert with neutralization systems. The 
detection system initially locates mines and a neutralization system is 
then used to relocate and neutralize the mine.
     Marine Mammal Systems. Navy personnel and Navy marine 
mammals work together to detect specified underwater objects. The Navy 
deploys trained bottlenose dolphins and California sea lions as part of 
the marine mammal mine-hunting and object-recovery system.
    Sonar systems to be used during Civilian Port Defense Mine 
Detection training would include AN/SQQ-32, AN/SLQ-48, AN/AQS-24, and 
handheld sonars (e.g., AN/PQS-2A). Of these sonar sources, only the AN/
SQQ-32 would require quantitative acoustic effects analysis, given its 
source parameters. The AN/SQQ-32 is a high frequency (between 10 and 
200 kilohertz [kHz]) sonar system; the specific source parameters of 
the AN/SQQ-32 are classified. The AN/AQS-24, AN/SLQ-48 and handheld 
sonars are considered de minimis sources, which are defined as sources 
with low source levels, narrow beams, downward directed transmission, 
short pulse lengths, frequencies above known hearing ranges, or some 
combination of these factors (Department of the Navy 2013). De minimis 
sources have been determined to not have potential impact to marine 
mammals.

Mine Neutralization

    Mine neutralization systems disrupt, disable, or detonate mines to 
clear ports and shipping lanes. Mine neutralization systems can clear 
individual mines or a large number of mines quickly. Two types of mine 
neutralization could be conducted, mechanical minesweeping and 
influence system minesweeping. Mechanical minesweeping consists of 
cutting the tether of mines moored in the water column or other means 
of physically releasing the mine. Moored mines cut loose by mechanical 
sweeping must then be neutralized or rendered safe for subsequent 
analysis. Influence minesweeping consists of simulating the magnetic, 
electric, acoustic, seismic, or pressure signature of a ship so that 
the mine detonates (no detonations would occur as part of the proposed 
training activities). Mine neutralization is included here to present 
the full spectrum of Civilian Port Defense Mine Warfare activities. The 
mine neutralization component of the proposed Civilian Port Defense 
training activities will not result in the incidental taking of marine 
mammals.

Dates, Duration, and Geographic Region

    Civilian Port Defense training activities are scheduled every year, 
typically alternating between the east and west coasts of the United 
States. Civilian Port Defense activities in 2015 are proposed to occur 
on the U.S. west coast near Los Angeles/Long Beach, California. 
Civilian Port Defense events are typically conducted in areas of ports 
or major surrounding waterways and within the shipping lanes and 
seaward to the 300 ft (91 m) depth contour.
    Civilian Port Defense activities would occur at the Ports of Los 
Angeles/Long Beach during October through November 2015 (Figure 2-1 of 
the application). The training exercise would occur for a period of two 
weeks in which active sonar would be utilized for two separate periods 
of four day long events. The AN/SQQ-32 sonar could be active for up to 
24 hours a day during these training events; however, the use of the 
AN/SQQ-32 would not be continuously active during the four day long 
period. Additional activities would occur during this time and are 
analyzed within the Navy's Environmental Assessment for Civilian Port 
Defense training activities. The Navy has determined there is potential 
for take as defined under MMPA for military readiness activities. 
Specifically take has potential to occur from utilization of active 
sonar sources. This stressor is the only aspect of the proposed 
training activities for which this IHA is being requested.
    The Ports of Los Angeles and Long Beach combined represent the 
busiest port along the U.S. West Coast and second busiest in the United 
States. In 2012 and 2013, approximately 4,550 and 4,500 vessel calls, 
respectively, for ships over 10,000 deadweight tons arrived at the 
Ports of Los Angeles and Long Beach (Louttit and Chavez 2014; U.S. 
Department of Transportation). This level of shipping would mean 
approximately 9,000 large ship transits to and from these ports and 
through the Study Area. By comparison, the next

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nearest large regional port, Port of San Diego, only had 318 vessel 
calls in 2012.

Description of Marine Mammals in the Area of the Specified Activity

    Nineteen marine mammal species are known to occur in the study 
area, including five mysticetes (baleen whales), nine odontocetes 
(dolphins and toothed whales), and five pinnipeds (seals and sea 
lions). Among these species are 31 stocks managed by NMFS. All species 
were quantitatively analyzed in the Navy Acoustic Effects Model (NAEMO; 
see Chapter 6.4 of the application for additional information on the 
modeling process). After completing the modeling simulations, seven 
species (each with a single stock) are estimated to potentially be 
taken by harassment as defined by the MMPA, as it applies to military 
readiness, during the proposed Civilian Port Defense activities due to 
use of active sonar sources. Based on a variety of factors, including 
source characterization, species presence, species hearing range, 
duration of exposure, and impact thresholds for species that may be 
present, the remainder of the species were not quantitatively predicted 
to be exposed to or affected by active acoustic transmissions related 
to the proposed activities that would result in harassment under the 
MMPA and, therefore, are not discussed further. Other potential 
stressors related to the proposed Civilian Port Defense activities 
(e.g., vessel movement/noise, in water device use) would not result in 
disruption or alteration of breeding, feeding, or nursing patterns that 
that would rise to a level of significance under the MMPA. The seven 
species with the potential to be taken by harassment during the 
proposed training activities are presented in Table 1 and relevant 
information on their status, behavior, life history, distribution, 
abundance, and hearing and vocalization is presented in Chapter 4 of 
the application. Further information on the general biology and ecology 
of marine mammals is included in the Navy's EA. In addition, NMFS 
publishes annual SARs for marine mammals, including stocks that occur 
within the Study Area (https://www.nmfs.noaa.gov/pr/species/mammals; 
Carretta et al., 2014; Allen and Angliss, 2014).

      Table 1--Marine Mammal Species With Estimated Exposures Above Harassment Thresholds in the Study Area
----------------------------------------------------------------------------------------------------------------
                                                                  Stock abundance
               Species                          Stock            \1\ (coefficient   Occurrence, seasonality, and
                                                                   of  variance)       duration in study area
----------------------------------------------------------------------------------------------------------------
                                                   Odontocetes
----------------------------------------------------------------------------------------------------------------
Long-beaked common dolphin (Delphinus  California.............      107,016 (0.42)  Common inshore of 820 ft
 capensis).                                                                          (250 m) isobath. Species
                                                                                     may be more abundant in
                                                                                     study area from May to
                                                                                     October.
Short-beaked common dolphin            California, Oregon,          411,211 (0.21)  Primary occurrence between
 (Delphinus delphis).                   Washington.                                  the coast and 300 nautical
                                                                                     miles (nm) from shore.
                                                                                     Prefers water depths
                                                                                     between 650 and 6,500 ft
                                                                                     (200 and 2,000 m).
Risso's dolphin (Grampus griseus)....  California, Oregon,            6,272 (0.30)  Frequently observed in
                                        Washington.                                  waters surrounding San
                                                                                     Clemente Island,
                                                                                     California. Occurs on the
                                                                                     shelf in the Southern
                                                                                     California Bight. Highest
                                                                                     abundance is in the cold
                                                                                     season.
Pacific white-sided dolphin            California, Oregon,           26,930 (0.28)  Occurs primarily in shelf
 (Lagenorhynchus obilquidens).          Washington.                                  and slope waters of
                                                                                     California; spends more
                                                                                     time in California waters
                                                                                     in colder water months.
Bottlenose dolphin coastal (Tursiops   Coastal California.....          323 (0.13)  Small, limited population;
 truncatus).                                                                         found within 1,640 ft (500
                                                                                     m) of the shoreline 99
                                                                                     percent of the time and
                                                                                     within 820 ft (250 m) 90
                                                                                     percent of the time.
----------------------------------------------------------------------------------------------------------------
                                                    Pinnipeds
----------------------------------------------------------------------------------------------------------------
Harbor seal (Phoca vitulina).........  California.............  \2\ 30,196 (0.157)  Found in moderate numbers.
                                                                                     Concentrate around haul-
                                                                                     outs in the Channel
                                                                                     Islands.
California sea lion (Zalophus          U.S....................             296,750  Most common pinniped.
 californianus).                                                                     Primarily congregate around
                                                                                     the Channel Islands. Peak
                                                                                     abundance is from May to
                                                                                     August.
----------------------------------------------------------------------------------------------------------------
\1\ From: Carretta et al. (2014). U.S. Pacific Marine Mammal Stock Assessments, 2013.
\2\ NMFS' draft U.S. Pacific Marine Mammal Stock Assessments, 2014 is proposing a small revision to the
  California stock of harbor seals from 30,196 to 30,968. No other proposed revisions are anticipated for these
  species.

Marine Mammal Hearing and Vocalizations

    Cetaceans have an auditory anatomy that follows the basic mammalian 
pattern, with some changes to adapt to the demands of hearing 
underwater. The typical mammalian ear is divided into an outer ear, 
middle ear, and inner ear. The outer ear is separated from the inner 
ear by a tympanic membrane, or eardrum. In terrestrial mammals, the 
outer ear, eardrum, and middle ear transmit airborne sound to the inner 
ear, where the sound waves are propagated through the cochlear fluid. 
Since the impedance of water is close to that of the tissues of a 
cetacean, the outer ear is not required to transduce sound energy as it 
does when sound waves travel from air to fluid (inner ear). Sound waves 
traveling through the inner ear cause the basilar membrane to vibrate. 
Specialized cells, called hair cells, respond to the vibration and 
produce nerve pulses that are transmitted to the central nervous 
system. Acoustic energy causes the basilar membrane in the cochlea to 
vibrate. Sensory cells at different positions along the basilar 
membrane are excited by different frequencies of sound (Pickles, 1998).
    Marine mammal vocalizations often extend both above and below the 
range of human hearing; vocalizations with frequencies lower than 20 Hz 
are labeled as infrasonic and those higher than 20 kHz as ultrasonic 
(National

[[Page 53661]]

Research Council (NRC), 2003; Figure 4-1). Measured data on the hearing 
abilities of cetaceans are sparse, particularly for the larger 
cetaceans such as the baleen whales. The auditory thresholds of some of 
the smaller odontocetes have been determined in captivity. It is 
generally believed that cetaceans should at least be sensitive to the 
frequencies of their own vocalizations. Comparisons of the anatomy of 
cetacean inner ears and models of the structural properties and the 
response to vibrations of the ear's components in different species 
provide an indication of likely sensitivity to various sound 
frequencies. The ears of small toothed whales are optimized for 
receiving high-frequency sound, while baleen whale inner ears are best 
in low to infrasonic frequencies (Ketten, 1992; 1997; 1998).
    Baleen whale vocalizations are composed primarily of frequencies 
below 1 kHz, and some contain fundamental frequencies as low as 16 Hz 
(Watkins et al., 1987; Richardson et al., 1995; Rivers, 1997; Moore et 
al., 1998; Stafford et al., 1999; Wartzok and Ketten, 1999) but can be 
as high as 24 kHz (humpback whale; Au et al., 2006). Clark and Ellison 
(2004) suggested that baleen whales use low-frequency sounds not only 
for long-range communication, but also as a simple form of echo 
ranging, using echoes to navigate and orient relative to physical 
features of the ocean. Information on auditory function in baleen 
whales is extremely lacking. Sensitivity to low-frequency sound by 
baleen whales has been inferred from observed vocalization frequencies, 
observed reactions to playback of sounds, and anatomical analyses of 
the auditory system. Although there is apparently much variation, the 
source levels of most baleen whale vocalizations lie in the range of 
150-190 dB re 1 microPascal ([micro]Pa) at 1 m. Low-frequency 
vocalizations made by baleen whales and their corresponding auditory 
anatomy suggest that they have good low-frequency hearing (Ketten, 
2000), although specific data on sensitivity, frequency or intensity 
discrimination, or localization abilities are lacking. Marine mammals, 
like all mammals, have typical U-shaped audiograms that begin with 
relatively low sensitivity (high threshold) at some specified low 
frequency with increased sensitivity (low threshold) to a species 
specific optimum followed by a generally steep rise at higher 
frequencies (high threshold) (Fay, 1988).
    The toothed whales produce a wide variety of sounds, which include 
species-specific broadband ``clicks'' with peak energy between 10 and 
200 kHz, individually variable ``burst pulse'' click trains, and 
constant frequency or frequency-modulated (FM) whistles ranging from 4 
to 16 kHz (Wartzok and Ketten, 1999). The general consensus is that the 
tonal vocalizations (whistles) produced by toothed whales play an 
important role in maintaining contact between dispersed individuals, 
while broadband clicks are used during echolocation (Wartzok and 
Ketten, 1999). Burst pulses have also been strongly implicated in 
communication, with some scientists suggesting that they play an 
important role in agonistic encounters (McCowan and Reiss, 1995), while 
others have proposed that they represent ``emotive'' signals in a 
broader sense, possibly representing graded communication signals 
(Herzing, 1996). Sperm whales, however, are known to produce only 
clicks, which are used for both communication and echolocation 
(Whitehead, 2003). Most of the energy of toothed whale social 
vocalizations is concentrated near 10 kHz, with source levels for 
whistles as high as 100 to 180 dB re 1 [micro]Pa at 1 m (Richardson et 
al., 1995). No odontocete has been shown audiometrically to have acute 
hearing (<80 dB re 1 [micro]Pa) below 500 Hz (DoN, 2001). Sperm whales 
produce clicks, which may be used to echolocate (Mullins et al., 1988), 
with a frequency range from less than 100 Hz to 30 kHz and source 
levels up to 230 dB re 1 [micro]Pa 1 m or greater (Mohl et al., 2000).

Brief Background on Sound

    An understanding of the basic properties of underwater sound is 
necessary to comprehend many of the concepts and analyses presented in 
this document. A summary is included below.
    Sound is a wave of pressure variations propagating through a medium 
(e.g., water). Pressure variations are created by compressing and 
relaxing the medium. Sound measurements can be expressed in two forms: 
intensity and pressure. Acoustic intensity is the average rate of 
energy transmitted through a unit area in a specified direction and is 
expressed in watts per square meter (W/m\2\). Acoustic intensity is 
rarely measured directly, but rather from ratios of pressures; the 
standard reference pressure for underwater sound is 1 [micro]Pa; for 
airborne sound, the standard reference pressure is 20 [micro]Pa 
(Richardson et al., 1995).
    Acousticians have adopted a logarithmic scale for sound 
intensities, which is denoted in decibels (dB). Decibel measurements 
represent the ratio between a measured pressure value and a reference 
pressure value (in this case 1 [micro]Pa or, for airborne sound, 20 
[micro]Pa). The logarithmic nature of the scale means that each 10-dB 
increase is a ten-fold increase in acoustic power (and a 20-dB increase 
is then a 100-fold increase in power; and a 30-dB increase is a 1,000-
fold increase in power). A ten-fold increase in acoustic power does not 
mean that the sound is perceived as being ten times louder, however. 
Humans perceive a 10-dB increase in sound level as a doubling of 
loudness, and a 10-dB decrease in sound level as a halving of loudness. 
The term ``sound pressure level'' implies a decibel measure and a 
reference pressure that is used as the denominator of the ratio. 
Throughout this document, NMFS uses 1 [micro]Pa (denoted re: 
1[micro]Pa) as a standard reference pressure unless noted otherwise.
    It is important to note that decibel values underwater and decibel 
values in air are not the same (different reference pressures and 
densities/sound speeds between media) and should not be directly 
compared. Because of the different densities of air and water and the 
different decibel standards (i.e., reference pressures) in air and 
water, a sound with the same level in air and in water would be 
approximately 62 dB lower in air. Thus, a sound that measures 160 dB 
(re 1 [micro]Pa) underwater would have the same approximate effective 
level as a sound that is 98 dB (re 20 [micro]Pa) in air.
    Sound frequency is measured in cycles per second, or Hertz 
(abbreviated Hz), and is analogous to musical pitch; high-pitched 
sounds contain high frequencies and low-pitched sounds contain low 
frequencies. Natural sounds in the ocean span a huge range of 
frequencies: from earthquake noise at 5 Hz to harbor porpoise clicks at 
150,000 Hz (150 kHz). These sounds are so low or so high in pitch that 
humans cannot even hear them; acousticians call these infrasonic 
(typically below 20 Hz) and ultrasonic (typically above 20,000 Hz) 
sounds, respectively. A single sound may be made up of many different 
frequencies together. Sounds made up of only a small range of 
frequencies are called ``narrowband'', and sounds with a broad range of 
frequencies are called ``broadband''; explosives are an example of a 
broadband sound source and active tactical sonars are an example of a 
narrowband sound source.
    When considering the influence of various kinds of sound on the 
marine environment, it is necessary to understand that different kinds 
of marine life are sensitive to different frequencies of sound. Current 
data indicate that not all marine mammal species have equal hearing 
capabilities

[[Page 53662]]

(Richardson et al., 1995; Southall et al., 1997; Wartzok and Ketten, 
1999; Au and Hastings, 2008).
    Southall et al. (2007) designated ``functional hearing groups'' for 
marine mammals based on available behavioral data; audiograms derived 
from auditory evoked potentials; anatomical modeling; and other data. 
Southall et al. (2007) also estimated the lower and upper frequencies 
of functional hearing for each group. However, animals are less 
sensitive to sounds at the outer edges of their functional hearing 
range and are more sensitive to a range of frequencies within the 
middle of their functional hearing range. Note that direct measurements 
of hearing sensitivity do not exist for all species of marine mammals, 
including low-frequency cetaceans. The functional hearing groups and 
the associated frequencies developed by Southall et al. (2007) were 
revised by Finneran and Jenkins (2012) and have been further modified 
by NOAA. Table 2 provides a summary of sound production and general 
hearing capabilities for marine mammal species (note that values in 
this table are not meant to reflect absolute possible maximum ranges, 
rather they represent the best known ranges of each functional hearing 
group). For purposes of the analysis in this document, marine mammals 
are arranged into the following functional hearing groups based on 
their generalized hearing sensitivities: High-frequency cetaceans, mid-
frequency cetaceans, low-frequency cetaceans (mysticetes), phocids 
(true seals), otariids (sea lion and fur seals), and mustelids (sea 
otters). A detailed discussion of the functional hearing groups can be 
found in Southall et al. (2007) and Finneran and Jenkins (2012).

            Table 2--Marine Mammal Functional Hearing Groups
------------------------------------------------------------------------
         Functional hearing group            Functional hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen        7 Hz to 25 kHz.
 whales).
Mid-frequency (MF) cetaceans (dolphins,     150 Hz to 160 kHz.
 toothed whales, beaked whales, bottlenose
 whales).
High-frequency (HF) cetaceans (true         200 Hz to 180 kHz.
 porpoises, Kogia, river dolphins,
 cephalorhynchid, Lagenorhynchus cruciger
 & L. australis).
Phocid pinnipeds (underwater) (true seals)  75 Hz to 100 kHz.
Otariid pinnipeds (underwater) (sea lions   100 Hz to 48 kHz.
 and fur seals).
------------------------------------------------------------------------
Adapted and derived from Southall et al. (2007).
* Represents frequency band of hearing for entire group as a composite
  (i.e., all species within the group), where individual species'
  hearing ranges are typically not as broad. Functional hearing is
  defined as the range of frequencies a group hears without
  incorporating non-acoustic mechanisms (Wartzok and Ketten, 1999). This
  is ~ 60 to ~ 70 dB above best hearing sensitivity (Southall et al.,
  2007) for all functional hearing groups except LF cetaceans, where no
  direct measurements on hearing are available. For LF cetaceans, the
  lower range is based on recommendations from Southall et al., 2007 and
  the upper range is based on information on inner ear anatomy and
  vocalizations.

    When sound travels (propagates) from its source, its loudness 
decreases as the distance traveled by the sound increases. Thus, the 
loudness of a sound at its source is higher than the loudness of that 
same sound a kilometer away. Acousticians often refer to the loudness 
of a sound at its source (typically referenced to one meter from the 
source) as the source level and the loudness of sound elsewhere as the 
received level (i.e., typically the receiver). For example, a humpback 
whale 3 km from a device that has a source level of 230 dB may only be 
exposed to sound that is 160 dB loud, depending on how the sound 
travels through water (e.g., spherical spreading [3 dB reduction with 
doubling of distance] was used in this example). As a result, it is 
important to understand the difference between source levels and 
received levels when discussing the loudness of sound in the ocean or 
its impacts on the marine environment.
    As sound travels from a source, its propagation in water is 
influenced by various physical characteristics, including water 
temperature, depth, salinity, and surface and bottom properties that 
cause refraction, reflection, absorption, and scattering of sound 
waves. Oceans are not homogeneous and the contribution of each of these 
individual factors is extremely complex and interrelated. The physical 
characteristics that determine the sound's speed through the water will 
change with depth, season, geographic location, and with time of day 
(as a result, in actual active sonar operations, crews will measure 
oceanic conditions, such as sea water temperature and depth, to 
calibrate models that determine the path the sonar signal will take as 
it travels through the ocean and how strong the sound signal will be at 
a given range along a particular transmission path). As sound travels 
through the ocean, the intensity associated with the wavefront 
diminishes, or attenuates. This decrease in intensity is referred to as 
propagation loss, also commonly called transmission loss.

Metrics Used in This Document

    This section includes a brief explanation of the two sound 
measurements (sound pressure level (SPL) and sound exposure level 
(SEL)) frequently used to describe sound levels in the discussions of 
acoustic effects in this document.
    Sound pressure level (SPL)--Sound pressure is the sound force per 
unit area, and is usually measured in micropascals ([micro]Pa), where 1 
Pa is the pressure resulting from a force of one newton exerted over an 
area of one square meter. SPL is expressed as the ratio of a measured 
sound pressure and a reference level.

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

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

SEL = SPL + 10 log (duration in seconds)

    As applied to active sonar, the SEL includes both the SPL of a 
sonar ping

[[Page 53663]]

and the total duration. Longer duration pings and/or pings with higher 
SPLs will have a higher SEL. If an animal is exposed to multiple pings, 
the SEL in each individual ping is summed to calculate the cumulative 
SEL. The cumulative SEL depends on the SPL, duration, and number of 
pings received. The thresholds that NMFS uses to indicate at what 
received level the onset of temporary threshold shift (TTS) and 
permanent threshold shift (PTS) in hearing are likely to occur are 
expressed as cumulative SEL.

Potential Effects of the Specified Activity on Marine Mammals

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

Non-Impulsive Sources

Direct Physiological Effects

    Based on the literature, there are two basic ways that non-
impulsive sources might directly result in physical trauma or damage: 
Noise-induced loss of hearing sensitivity (more commonly-called 
``threshold shift'') and acoustically mediated bubble growth.
    Threshold Shift (noise-induced loss of hearing)--When animals 
exhibit reduced hearing sensitivity (i.e., sounds must be louder for an 
animal to detect them) following exposure to an intense sound or sound 
for long duration, it is referred to as a noise-induced threshold shift 
(TS). An animal can experience temporary threshold shift (TTS) or 
permanent threshold shift (PTS). TTS can last from minutes or hours to 
days (i.e., there is complete recovery), can occur in specific 
frequency ranges (i.e., an animal might only have a temporary loss of 
hearing sensitivity between the frequencies of 1 and 10 kHz), and can 
be of varying amounts (for example, an animal's hearing sensitivity 
might be reduced initially by only 6 dB or reduced by 30 dB). PTS is 
permanent, but some recovery is possible. PTS can also occur in a 
specific frequency range and amount as mentioned above for TTS.
    The following physiological mechanisms are thought to play a role 
in inducing auditory TS: Effects to sensory hair cells in the inner ear 
that reduce their sensitivity, modification of the chemical environment 
within the sensory cells, residual muscular activity in the middle ear, 
displacement of certain inner ear membranes, increased blood flow, and 
post-stimulatory reduction in both efferent and sensory neural output 
(Southall et al., 2007). The amplitude, duration, frequency, temporal 
pattern, and energy distribution of sound exposure all can affect the 
amount of associated TS and the frequency range in which it occurs. As 
amplitude and duration of sound exposure increase, so, generally, does 
the amount of TS, along with the recovery time. For intermittent 
sounds, less TS could occur than compared to a continuous exposure with 
the same energy (some recovery could occur between intermittent 
exposures depending on the duty cycle between sounds) (Kryter et al., 
1966; Ward, 1997). For example, one short but loud (higher SPL) sound 
exposure may induce the same impairment as one longer but softer sound, 
which in turn may cause more impairment than a series of several 
intermittent softer sounds with the same total energy (Ward, 1997). 
Additionally, though TTS is temporary, prolonged exposure to sounds 
strong enough to elicit TTS, or shorter-term exposure to sound levels 
well above the TTS threshold, can cause PTS, at least in terrestrial 
mammals (Kryter, 1985). Although in the case of mid- and high-frequency 
active sonar (MFAS/HFAS), animals are not expected to be exposed to 
levels high enough or durations long enough to result in PTS.
    PTS is considered auditory injury (Southall et al., 2007). 
Irreparable damage to the inner or outer cochlear hair cells may cause 
PTS; however, other mechanisms are also involved, such as exceeding the 
elastic limits of certain tissues and membranes in the middle and inner 
ears and resultant changes in the chemical composition of the inner ear 
fluids (Southall et al., 2007).
    Although the published body of scientific literature contains 
numerous theoretical studies and discussion papers on hearing 
impairments that can occur with exposure to a loud sound, only a few 
studies provide empirical information on the levels at which noise-
induced loss in hearing sensitivity occurs in nonhuman animals. For 
marine mammals, published data are limited to the captive bottlenose 
dolphin, beluga, harbor porpoise, and Yangtze finless porpoise 
(Finneran et al., 2000, 2002b, 2003, 2005a, 2007, 2010a, 2010b; 
Finneran and Schlundt, 2010; Lucke et al., 2009; Mooney et al., 2009a, 
2009b; Popov et al., 2011a, 2011b; Kastelein et al., 2012a; Schlundt et 
al., 2000; Nachtigall et al., 2003, 2004). For pinnipeds in water, data 
are limited to measurements of TTS in harbor seals, an elephant seal, 
and California sea lions (Kastak et al., 1999, 2005; Kastelein et al., 
2012b).

[[Page 53664]]

    Marine mammal hearing plays a critical role in communication with 
conspecifics, and interpretation of environmental cues for purposes 
such as predator avoidance and prey capture. Depending on the degree 
(elevation of threshold in dB), duration (i.e., recovery time), and 
frequency range of TTS, and the context in which it is experienced, TTS 
can have effects on marine mammals ranging from discountable to serious 
(similar to those discussed in auditory masking, below). For example, a 
marine mammal may be able to readily compensate for a brief, relatively 
small amount of TTS in a non-critical frequency range that occurs 
during a time where ambient noise is lower and there are not as many 
competing sounds present. Alternatively, a larger amount and longer 
duration of TTS sustained during time when communication is critical 
for successful mother/calf interactions could have more serious 
impacts. Also, depending on the degree and frequency range, the effects 
of PTS on an animal could range in severity, although it is considered 
generally more serious because it is a permanent condition. Of note, 
reduced hearing sensitivity as a simple function of aging has been 
observed in marine mammals, as well as humans and other taxa (Southall 
et al., 2007), so one can infer that strategies exist for coping with 
this condition to some degree, though likely not without cost.
    Acoustically Mediated Bubble Growth--One theoretical cause of 
injury to marine mammals is rectified diffusion (Crum and Mao, 1996), 
the process of increasing the size of a bubble by exposing it to a 
sound field. This process could be facilitated if the environment in 
which the ensonified bubbles exist is supersaturated with gas. 
Repetitive diving by marine mammals can cause the blood and some 
tissues to accumulate gas to a greater degree than is supported by the 
surrounding environmental pressure (Ridgway and Howard, 1979). The 
deeper and longer dives of some marine mammals (for example, beaked 
whales) are theoretically predicted to induce greater supersaturation 
(Houser et al., 2001b). If rectified diffusion were possible in marine 
mammals exposed to high-level sound, conditions of tissue 
supersaturation could theoretically speed the rate and increase the 
size of bubble growth. Subsequent effects due to tissue trauma and 
emboli would presumably mirror those observed in humans suffering from 
decompression sickness.
    It is unlikely that the short duration of sonar pings would be long 
enough to drive bubble growth to any substantial size, if such a 
phenomenon occurs. However, an alternative but related hypothesis has 
also been suggested: Stable bubbles could be destabilized by high-level 
sound exposures such that bubble growth then occurs through static 
diffusion of gas out of the tissues. In such a scenario the marine 
mammal would need to be in a gas-supersaturated state for a long enough 
period of time for bubbles to become of a problematic size. Recent 
research with ex vivo supersaturated bovine tissues suggested that, for 
a 37 kHz signal, a sound exposure of approximately 215 dB referenced to 
(re) 1 [mu]Pa would be required before microbubbles became destabilized 
and grew (Crum et al., 2005). Assuming spherical spreading loss and a 
nominal sonar source level of 235 dB re 1 [mu]Pa at 1 m, a whale would 
need to be within 10 m (33 ft.) of the sonar dome to be exposed to such 
sound levels. Furthermore, tissues in the study were supersaturated by 
exposing them to pressures of 400-700 kilopascals for periods of hours 
and then releasing them to ambient pressures. Assuming the 
equilibration of gases with the tissues occurred when the tissues were 
exposed to the high pressures, levels of supersaturation in the tissues 
could have been as high as 400-700 percent. These levels of tissue 
supersaturation are substantially higher than model predictions for 
marine mammals (Houser et al., 2001; Saunders et al., 2008). It is 
improbable that this mechanism is responsible for stranding events or 
traumas associated with beaked whale strandings. Both the degree of 
supersaturation and exposure levels observed to cause microbubble 
destabilization are unlikely to occur, either alone or in concert.
    Yet another hypothesis (decompression sickness) has speculated that 
rapid ascent to the surface following exposure to a startling sound 
might produce tissue gas saturation sufficient for the evolution of 
nitrogen bubbles (Jepson et al., 2003; Fernandez et al., 2005; 
Fern[aacute]ndez et al., 2012). In this scenario, the rate of ascent 
would need to be sufficiently rapid to compromise behavioral or 
physiological protections against nitrogen bubble formation. 
Alternatively, Tyack et al. (2006) studied the deep diving behavior of 
beaked whales and concluded that: ``Using current models of breath-hold 
diving, we infer that their natural diving behavior is inconsistent 
with known problems of acute nitrogen supersaturation and embolism.'' 
Collectively, these hypotheses can be referred to as ``hypotheses of 
acoustically mediated bubble growth.''
    Although theoretical predictions suggest the possibility for 
acoustically mediated bubble growth, there is considerable disagreement 
among scientists as to its likelihood (Piantadosi and Thalmann, 2004; 
Evans and Miller, 2003). Crum and Mao (1996) hypothesized that received 
levels would have to exceed 190 dB in order for there to be the 
possibility of significant bubble growth due to supersaturation of 
gases in the blood (i.e., rectified diffusion). More recent work 
conducted by Crum et al. (2005) demonstrated the possibility of 
rectified diffusion for short duration signals, but at SELs and tissue 
saturation levels that are highly improbable to occur in diving marine 
mammals. To date, energy levels (ELs) predicted to cause in vivo bubble 
formation within diving cetaceans have not been evaluated (NOAA, 
2002b). Although it has been argued that traumas from some recent 
beaked whale strandings are consistent with gas emboli and bubble-
induced tissue separations (Jepson et al., 2003), there is no 
conclusive evidence of this. However, Jepson et al. (2003, 2005) and 
Fernandez et al. (2004, 2005, 2012) concluded that in vivo bubble 
formation, which may be exacerbated by deep, long-duration, repetitive 
dives may explain why beaked whales appear to be particularly 
vulnerable to sonar exposures. Further investigation is needed to 
further assess the potential validity of these hypotheses.

Acoustic Masking

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

[[Page 53665]]

exposure to noise in a narrow band of similar frequencies. As the sound 
level increases, though, the detection of frequencies above those of 
the masking stimulus decreases also. This principle is expected to 
apply to marine mammals as well because of common biomechanical 
cochlear properties across taxa.
    Richardson et al. (1995b) argued that the maximum radius of 
influence of an industrial noise (including broadband low frequency 
sound transmission) on a marine mammal is the distance from the source 
to the point at which the noise can barely be heard. This range is 
determined by either the hearing sensitivity of the animal or the 
background noise level present. Industrial masking is most likely to 
affect some species' ability to detect communication calls and natural 
sounds (i.e., surf noise, prey noise, etc.; Richardson et al., 1995).
    The echolocation calls of toothed whales are subject to masking by 
high frequency sound. Human data indicate low-frequency sound can mask 
high-frequency sounds (i.e., upward masking). Studies on captive 
odontocetes by Au et al. (1974, 1985, 1993) indicate that some species 
may use various processes to reduce masking effects (e.g., adjustments 
in echolocation call intensity or frequency as a function of background 
noise conditions). There is also evidence that the directional hearing 
abilities of odontocetes are useful in reducing masking at the high-
frequencies these cetaceans use to echolocate, but not at the low-to-
moderate frequencies they use to communicate (Zaitseva et al., 1980). A 
recent study by Nachtigall and Supin (2008) showed that false killer 
whales adjust their hearing to compensate for ambient sounds and the 
intensity of returning echolocation signals.
    As mentioned previously, the functional hearing ranges of 
odontocetes and pinnipeds underwater overlap the frequencies of the 
high-frequency sonar source (i.e., AN/SQQ-32) used in the Navy's 
training exercises. Additionally, species' vocal repertoires span 
across the frequencies of the sonar source used by the Navy. The closer 
the characteristics of the masking signal to the signal of interest, 
the more likely masking is to occur. For hull-mounted and towed sonar 
the pulse length and low duty cycle of the HFAS signal makes it less 
likely that masking would occur as a result. Further, the frequency 
band of the sonar is narrow, limiting the likelihood of auditory 
masking.

Impaired Communication

    In addition to making it more difficult for animals to perceive 
acoustic cues in their environment, anthropogenic sound presents 
separate challenges for animals that are vocalizing. When they 
vocalize, animals are aware of environmental conditions that affect the 
``active space'' of their vocalizations, which is the maximum area 
within which their vocalizations can be detected before it drops to the 
level of ambient noise (Brenowitz, 2004; Brumm et al., 2004; Lohr et 
al., 2003). Animals are also aware of environmental conditions that 
affect whether listeners can discriminate and recognize their 
vocalizations from other sounds, which is more important than simply 
detecting that a vocalization is occurring (Brenowitz, 1982; Brumm et 
al., 2004; Dooling, 2004, Marten and Marler, 1977; Patricelli et al., 
2006). Most animals that vocalize have evolved with an ability to make 
adjustments to their vocalizations to increase the signal-to-noise 
ratio, active space, and recognizability/distinguishability of their 
vocalizations in the face of temporary changes in background noise 
(Brumm et al., 2004; Patricelli et al., 2006). Vocalizing animals can 
make adjustments to vocalization characteristics such as the frequency 
structure, amplitude, temporal structure, and temporal delivery.
    Many animals will combine several of these strategies to compensate 
for high levels of background noise. Anthropogenic sounds that reduce 
the signal-to-noise ratio of animal vocalizations, increase the masked 
auditory thresholds of animals listening for such vocalizations, or 
reduce the active space of an animal's vocalizations impair 
communication between animals. Most animals that vocalize have evolved 
strategies to compensate for the effects of short-term or temporary 
increases in background or ambient noise on their songs or calls. 
Although the fitness consequences of these vocal adjustments remain 
unknown, like most other trade-offs animals must make, some of these 
strategies probably come at a cost (Patricelli et al., 2006). For 
example, vocalizing more loudly in noisy environments may have 
energetic costs that decrease the net benefits of vocal adjustment and 
alter a bird's energy budget (Brumm, 2004; Wood and Yezerinac, 2006). 
Shifting songs and calls to higher frequencies may also impose 
energetic costs (Lambrechts, 1996).

Stress Responses

    Classic stress responses begin when an animal's central nervous 
system perceives a potential threat to its homeostasis. That perception 
triggers stress responses regardless of whether a stimulus actually 
threatens the animal; the mere perception of a threat is sufficient to 
trigger a stress response (Moberg, 2000; Sapolsky et al., 2005; Seyle, 
1950). Once an animal's central nervous system perceives a threat, it 
mounts a biological response or defense that consists of a combination 
of the four general biological defense responses: behavioral responses, 
autonomic nervous system responses, neuroendocrine responses, or immune 
responses.
    In the case of many stressors, an animal's first and sometimes most 
economical (in terms of biotic costs) response is behavioral avoidance 
of the potential stressor or avoidance of continued exposure to a 
stressor. An animal's second line of defense to stressors involves the 
sympathetic part of the autonomic nervous system and the classical 
``fight or flight'' response which includes the cardiovascular system, 
the gastrointestinal system, the exocrine glands, and the adrenal 
medulla to produce changes in heart rate, blood pressure, and 
gastrointestinal activity that humans commonly associate with 
``stress.'' These responses have a relatively short duration and may or 
may not have significant long-term effect on an animal's welfare.
    An animal's third line of defense to stressors involves its 
neuroendocrine systems; the system that has received the most study has 
been the hypothalamus-pituitary-adrenal system (also known as the HPA 
axis in mammals or the hypothalamus-pituitary-interrenal axis in fish 
and some reptiles). Unlike stress responses associated with the 
autonomic nervous system, virtually all neuro-endocrine functions that 
are affected by stress--including immune competence, reproduction, 
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been 
implicated in failed reproduction (Moberg, 1987; Rivier, 1995), altered 
metabolism (Elasser et al., 2000), reduced immune competence (Blecha, 
2000), and behavioral disturbance. Increases in the circulation of 
glucocorticosteroids (cortisol, corticosterone, and aldosterone in 
marine mammals; see Romano et al., 2004) have been equated with stress 
for many years.

[[Page 53666]]

    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and distress is the biotic cost 
of the response. During a stress response, an animal uses glycogen 
stores that can be quickly replenished once the stress is alleviated. 
In such circumstances, the cost of the stress response would not pose a 
risk to the animal's welfare. However, when an animal does not have 
sufficient energy reserves to satisfy the energetic costs of a stress 
response, energy resources must be diverted from other biotic function, 
which impairs those functions that experience the diversion. For 
example, when mounting a stress response diverts energy away from 
growth in young animals, those animals may experience stunted growth. 
When mounting a stress response diverts energy from a fetus, an 
animal's reproductive success and its fitness will suffer. In these 
cases, the animals will have entered a pre-pathological or pathological 
state which is called ``distress'' (Seyle, 1950) or ``allostatic 
loading'' (McEwen and Wingfield, 2003). This pathological state will 
last until the animal replenishes its biotic reserves sufficient to 
restore normal function. Note that these examples involved a long-term 
(days or weeks) stress response exposure to stimuli.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses have also been documented 
fairly well through controlled experiments; because this physiology 
exists in every vertebrate that has been studied, it is not surprising 
that stress responses and their costs have been documented in both 
laboratory and free-living animals (for examples see, Holberton et al., 
1996; Hood et al., 1998; Jessop et al., 2003; Krausman et al., 2004; 
Lankford et al., 2005; Reneerkens et al., 2002; Thompson and Hamer, 
2000). Information has also been collected on the physiological 
responses of marine mammals to exposure to anthropogenic sounds (Fair 
and Becker, 2000; Romano et al., 2002; Wright et al., 2008). For 
example, Rolland et al. (2012) found that noise reduction from reduced 
ship traffic in the Bay of Fundy was associated with decreased stress 
in North Atlantic right whales. In a conceptual model developed by the 
Population Consequences of Acoustic Disturbance (PCAD) working group, 
serum hormones were identified as possible indicators of behavioral 
effects that are translated into altered rates of reproduction and 
mortality. The Office of Naval Research hosted a workshop (Effects of 
Stress on Marine Mammals Exposed to Sound) in 2009 that focused on this 
very topic (ONR, 2009).
    Studies of other marine animals and terrestrial animals would also 
lead us to expect some marine mammals to experience physiological 
stress responses and, perhaps, physiological responses that would be 
classified as ``distress'' upon exposure to high frequency, mid-
frequency and low-frequency sounds. For example, Jansen (1998) reported 
on the relationship between acoustic exposures and physiological 
responses that are indicative of stress responses in humans (for 
example, elevated respiration and increased heart rates). Jones (1998) 
reported on reductions in human performance when faced with acute, 
repetitive exposures to acoustic disturbance. Trimper et al. (1998) 
reported on the physiological stress responses of osprey to low-level 
aircraft noise while Krausman et al. (2004) reported on the auditory 
and physiology stress responses of endangered Sonoran pronghorn to 
military overflights. Smith et al. (2004a, 2004b), for example, 
identified noise-induced physiological transient stress responses in 
hearing-specialist fish (i.e., goldfish) that accompanied short- and 
long-term hearing losses. Welch and Welch (1970) reported physiological 
and behavioral stress responses that accompanied damage to the inner 
ears of fish and several mammals.
    Hearing is one of the primary senses marine mammals use to gather 
information about their environment and to communicate with 
conspecifics. Although empirical information on the relationship 
between sensory impairment (TTS, PTS, and acoustic masking) on marine 
mammals remains limited, it seems reasonable to assume that reducing an 
animal's ability to gather information about its environment and to 
communicate with other members of its species would be stressful for 
animals that use hearing as their primary sensory mechanism. Therefore, 
we assume that acoustic exposures sufficient to trigger onset PTS or 
TTS would be accompanied by physiological stress responses because 
terrestrial animals exhibit those responses under similar conditions 
(NRC, 2003). More importantly, marine mammals might experience stress 
responses at received levels lower than those necessary to trigger 
onset TTS. Based on empirical studies of the time required to recover 
from stress responses (Moberg, 2000), we also assume that stress 
responses are likely to persist beyond the time interval required for 
animals to recover from TTS and might result in pathological and pre-
pathological states that would be as significant as behavioral 
responses to TTS.

Behavioral Disturbance

    Behavioral responses to sound are highly variable and context-
specific. Many different variables can influence an animal's perception 
of and response to (nature and magnitude) an acoustic event. An 
animal's prior experience with a sound or sound source effects whether 
it is less likely (habituation) or more likely (sensitization) to 
respond to certain sounds in the future (animals can also be innately 
pre-disposed to respond to certain sounds in certain ways) (Southall et 
al., 2007). Related to the sound itself, the perceived nearness of the 
sound, bearing of the sound (approaching vs. retreating), similarity of 
a sound to biologically relevant sounds in the animal's environment 
(i.e., calls of predators, prey, or conspecifics), and familiarity of 
the sound may affect the way an animal responds to the sound (Southall 
et al., 2007). Individuals (of different age, gender, reproductive 
status, etc.) among most populations will have variable hearing 
capabilities, and differing behavioral sensitivities to sounds that 
will be affected by prior conditioning, experience, and current 
activities of those individuals. Often, specific acoustic features of 
the sound and contextual variables (i.e., proximity, duration, or 
recurrence of the sound or the current behavior that the marine mammal 
is engaged in or its prior experience), as well as entirely separate 
factors such as the physical presence of a nearby vessel, may be more 
relevant to the animal's response than the received level alone.
    Exposure of marine mammals to sound sources can result in no 
response or responses including, but not limited to: Increased 
alertness; orientation or attraction to a sound source; vocal 
modifications; cessation of feeding; cessation of social interaction; 
alteration of movement or diving behavior; habitat abandonment 
(temporary or permanent); and, in severe cases, panic, flight, 
stampede, or stranding, potentially resulting in death (Southall et 
al., 2007). A review of marine mammal responses to anthropogenic sound 
was first conducted by Richardson and others in 1995. A more recent 
review (Nowacek et al., 2007) addresses studies conducted since 1995 
and focuses on observations where the received sound level of the 
exposed marine mammal(s) was known or could be estimated. The following 
sub-sections provide examples of behavioral responses that provide an 
idea of the variability in behavioral

[[Page 53667]]

responses that would be expected given the differential sensitivities 
of marine mammal species to sound and the wide range of potential 
acoustic sources to which a marine mammal may be exposed. Estimates of 
the types of behavioral responses that could occur for a given sound 
exposure should be determined from the literature that is available for 
each species, or extrapolated from closely related species when no 
information exists.
    Flight Response--A flight response is a dramatic change in normal 
movement to a directed and rapid movement away from the perceived 
location of a sound source. Relatively little information on flight 
responses of marine mammals to anthropogenic signals exist, although 
observations of flight responses to the presence of predators have 
occurred (Connor and Heithaus, 1996). Flight responses have been 
speculated as being a component of marine mammal strandings associated 
with sonar activities (Evans and England, 2001).
    Response to Predator--Evidence suggests that at least some marine 
mammals have the ability to acoustically identify potential predators. 
For example, harbor seals that reside in the coastal waters off British 
Columbia are frequently targeted by certain groups of killer whales, 
but not others. The seals discriminate between the calls of threatening 
and non-threatening killer whales (Deecke et al., 2002), a capability 
that should increase survivorship while reducing the energy required 
for attending to and responding to all killer whale calls. The 
occurrence of masking or hearing impairment provides a means by which 
marine mammals may be prevented from responding to the acoustic cues 
produced by their predators. Whether or not this is a possibility 
depends on the duration of the masking/hearing impairment and the 
likelihood of encountering a predator during the time that predator 
cues are impeded.
    Diving--Changes in dive behavior can vary widely. They may consist 
of increased or decreased dive times and surface intervals as well as 
changes in the rates of ascent and descent during a dive. Variations in 
dive behavior may reflect interruptions in biologically significant 
activities (e.g., foraging) or they may be of little biological 
significance. Variations in dive behavior may also expose an animal to 
potentially harmful conditions (e.g., increasing the chance of ship-
strike) or may serve as an avoidance response that enhances 
survivorship. The impact of a variation in diving resulting from an 
acoustic exposure depends on what the animal is doing at the time of 
the exposure and the type and magnitude of the response.
    Nowacek et al. (2004) reported disruptions of dive behaviors in 
foraging North Atlantic right whales when exposed to an alerting 
stimulus, an action, they noted, that could lead to an increased 
likelihood of ship strike. However, the whales did not respond to 
playbacks of either right whale social sounds or vessel noise, 
highlighting the importance of the sound characteristics in producing a 
behavioral reaction. Conversely, Indo-Pacific humpback dolphins have 
been observed to dive for longer periods of time in areas where vessels 
were present and/or approaching (Ng and Leung, 2003). In both of these 
studies, the influence of the sound exposure cannot be decoupled from 
the physical presence of a surface vessel, thus complicating 
interpretations of the relative contribution of each stimulus to the 
response. Indeed, the presence of surface vessels, their approach, and 
speed of approach, seemed to be significant factors in the response of 
the Indo-Pacific humpback dolphins (Ng and Leung, 2003). Low frequency 
signals of the Acoustic Thermometry of Ocean Climate (ATOC) sound 
source were not found to affect dive times of humpback whales in 
Hawaiian waters (Frankel and Clark, 2000) or to overtly affect elephant 
seal dives (Costa et al., 2003). They did, however, produce subtle 
effects that varied in direction and degree among the individual seals, 
illustrating the equivocal nature of behavioral effects and consequent 
difficulty in defining and predicting them.
    Due to past incidents of beaked whale strandings associated with 
sonar operations, feedback paths are provided between avoidance and 
diving and indirect tissue effects. This feedback accounts for the 
hypothesis that variations in diving behavior and/or avoidance 
responses can possibly result in nitrogen tissue supersaturation and 
nitrogen off-gassing, possibly to the point of deleterious vascular 
bubble formation (Jepson et al., 2003). Although hypothetical, 
discussions surrounding this potential process are controversial.
    Foraging--Disruption of feeding behavior can be difficult to 
correlate with anthropogenic sound exposure, so it is usually inferred 
by observed displacement from known foraging areas, the appearance of 
secondary indicators (e.g., bubble nets or sediment plumes), or changes 
in dive behavior. Noise from seismic surveys was not found to impact 
the feeding behavior in western grey whales off the coast of Russia 
(Yazvenko et al., 2007) and sperm whales engaged in foraging dives did 
not abandon dives when exposed to distant signatures of seismic airguns 
(Madsen et al., 2006). However, Miller et al. (2009) reported buzz 
rates (a proxy for feeding) 19 percent lower during exposure to distant 
signatures of seismic airguns. Balaenopterid whales exposed to moderate 
low-frequency signals similar to the ATOC sound source demonstrated no 
variation in foraging activity (Croll et al., 2001), whereas five out 
of six North Atlantic right whales exposed to an acoustic alarm 
interrupted their foraging dives (Nowacek et al., 2004). Although the 
received sound pressure levels were similar in the latter two studies, 
the frequency, duration, and temporal pattern of signal presentation 
were different. These factors, as well as differences in species 
sensitivity, are likely contributing factors to the differential 
response. Blue whales exposed to simulated mid-frequency sonar in the 
Southern California Bight were less likely to produce low frequency 
calls usually associated with feeding behavior (Melc[oacute]n et al., 
2012). It is not known whether the lower rates of calling actually 
indicated a reduction in feeding behavior or social contact since the 
study used data from remotely deployed, passive acoustic monitoring 
buoys. In contrast, blue whales increased their likelihood of calling 
when ship noise was present, and decreased their likelihood of calling 
in the presence of explosive noise, although this result was not 
statistically significant (Melc[oacute]n et al., 2012). Additionally, 
the likelihood of an animal calling decreased with the increased 
received level of mid-frequency sonar, beginning at a SPL of 
approximately 110-120 dB re 1 [micro]Pa (Melc[oacute]n et al., 2012). 
Preliminary results from the 2010-2011 field season of an ongoing 
behavioral response study in Southern California waters indicated that, 
in some cases and at low received levels, tagged blue whales responded 
to mid-frequency sonar but that those responses were mild and there was 
a quick return to their baseline activity (Southall et al., 2011). A 
determination of whether foraging disruptions incur fitness 
consequences will require information on or estimates of the energetic 
requirements of the individuals and the relationship between prey 
availability, foraging effort and success, and the life history stage 
of the animal. Goldbogen et al., (2013) monitored behavioral responses 
of tagged blue whales located in feeding areas when exposed simulated 
MFA

[[Page 53668]]

sonar. Responses varied depending on behavioral context, with deep 
feeding whales being more significantly affected (i.e., generalized 
avoidance; cessation of feeding; increased swimming speeds; or directed 
travel away from the source) compared to surface feeding individuals 
that typically showed no change in behavior. Non-feeding whales also 
seemed to be affected by exposure. The authors indicate that disruption 
of feeding and displacement could impact individual fitness and health. 
However, for this to be true, we would have to assume that an 
individual whale could not compensate for this lost feeding opportunity 
by either immediately feeding at another location, by feeding shortly 
after cessation of acoustic exposure, or by feeding at a later time. 
There is no indication this is the case, particularly since unconsumed 
prey would likely still be available in the environment in most cases 
following the cessation of acoustic exposure.
    Breathing--Variations in respiration naturally vary with different 
behaviors and variations in respiration rate as a function of acoustic 
exposure can be expected to co-occur with other behavioral reactions, 
such as a flight response or an alteration in diving. However, 
respiration rates in and of themselves may be representative of 
annoyance or an acute stress response. Mean exhalation rates of gray 
whales at rest and while diving were found to be unaffected by seismic 
surveys conducted adjacent to the whale feeding grounds (Gailey et al., 
2007). Studies with captive harbor porpoises showed increased 
respiration rates upon introduction of acoustic alarms (Kastelein et 
al., 2001; Kastelein et al., 2006a) and emissions for underwater data 
transmission (Kastelein et al., 2005). However, exposure of the same 
acoustic alarm to a striped dolphin under the same conditions did not 
elicit a response (Kastelein et al., 2006a), again highlighting the 
importance in understanding species differences in the tolerance of 
underwater noise when determining the potential for impacts resulting 
from anthropogenic sound exposure (Southall et al., 2007; Henderson et 
al., 2014).
    Social Relationships--Social interactions between mammals can be 
affected by noise via the disruption of communication signals or by the 
displacement of individuals. Disruption of social relationships 
therefore depends on the disruption of other behaviors (e.g., caused 
avoidance, masking, etc.) and no specific overview is provided here. 
However, social disruptions must be considered in context of the 
relationships that are affected. Long-term disruptions of mother/calf 
pairs or mating displays have the potential to affect the growth and 
survival or reproductive effort/success of individuals, respectively.
    Vocalizations (also see Masking Section)--Vocal changes in response 
to anthropogenic noise can occur across the repertoire of sound 
production modes used by marine mammals, such as whistling, 
echolocation click production, calling, and singing. Changes may result 
in response to a need to compete with an increase in background noise 
or may reflect an increased vigilance or startle response. For example, 
in the presence of low-frequency active sonar, humpback whales have 
been observed to increase the length of their ``songs'' (Miller et al., 
2000; Fristrup et al., 2003), possibly due to the overlap in 
frequencies between the whale song and the low-frequency active sonar. 
A similar compensatory effect for the presence of low-frequency vessel 
noise has been suggested for right whales; right whales have been 
observed to shift the frequency content of their calls upward while 
reducing the rate of calling in areas of increased anthropogenic noise 
(Parks et al., 2007). Killer whales off the northwestern coast of the 
U.S. have been observed to increase the duration of primary calls once 
a threshold in observing vessel density (e.g., whale watching) was 
reached, which has been suggested as a response to increased masking 
noise produced by the vessels (Foote et al., 2004; NOAA, 2014b). In 
contrast, both sperm and pilot whales potentially ceased sound 
production during the Heard Island feasibility test (Bowles et al., 
1994), although it cannot be absolutely determined whether the 
inability to acoustically detect the animals was due to the cessation 
of sound production or the displacement of animals from the area.
    Avoidance--Avoidance is the displacement of an individual from an 
area as a result of the presence of a sound. Richardson et al., (1995) 
noted that avoidance reactions are the most obvious manifestations of 
disturbance in marine mammals. It is qualitatively different from the 
flight response, but also differs in the magnitude of the response 
(i.e., directed movement, rate of travel, etc.). Oftentimes avoidance 
is temporary, and animals return to the area once the noise has ceased. 
Longer term displacement is possible, however, which can lead to 
changes in abundance or distribution patterns of the species in the 
affected region if they do not become acclimated to the presence of the 
sound (Blackwell et al., 2004; Bejder et al., 2006; Teilmann et al., 
2006). Acute avoidance responses have been observed in captive 
porpoises and pinnipeds exposed to a number of different sound sources 
(Kastelein et al., 2001; Finneran et al., 2003; Kastelein et al., 
2006a; Kastelein et al., 2006b). Short-term avoidance of seismic 
surveys, low frequency emissions, and acoustic deterrents have also 
been noted in wild populations of odontocetes (Bowles et al., 1994; 
Goold, 1996; 1998; Stone et al., 2000; Morton and Symonds, 2002) and to 
some extent in mysticetes (Gailey et al., 2007), while longer term or 
repetitive/chronic displacement for some dolphin groups and for 
manatees has been suggested to be due to the presence of chronic vessel 
noise (Haviland-Howell et al., 2007; Miksis-Olds et al., 2007).
    Maybaum (1993) conducted sound playback experiments to assess the 
effects of MFAS on humpback whales in Hawaiian waters. Specifically, 
she exposed focal pods to sounds of a 3.3-kHz sonar pulse, a sonar 
frequency sweep from 3.1 to 3.6 kHz, and a control (blank) tape while 
monitoring behavior, movement, and underwater vocalizations. The two 
types of sonar signals (which both contained mid- and low-frequency 
components) differed in their effects on the humpback whales, but both 
resulted in avoidance behavior. The whales responded to the pulse by 
increasing their distance from the sound source and responded to the 
frequency sweep by increasing their swimming speeds and track 
linearity. In the Caribbean, sperm whales avoided exposure to mid-
frequency submarine sonar pulses, in the range of 1000 Hz to 10,000 Hz 
(IWC 2005).
    Kvadsheim et al., (2007) conducted a controlled exposure experiment 
in which killer whales fitted with D-tags were exposed to mid-frequency 
active sonar (Source A: a 1.0 second upsweep 209 dB @1-2 kHz every 10 
seconds for 10 minutes; Source B: with a 1.0 second upsweep 197 dB @6-7 
kHz every 10 seconds for 10 minutes). When exposed to Source A, a 
tagged whale and the group it was traveling with did not appear to 
avoid the source. When exposed to Source B, the tagged whales along 
with other whales that had been carousel feeding, ceased feeding during 
the approach of the sonar and moved rapidly away from the source. When 
exposed to Source B, Kvadsheim and his co-workers reported that a 
tagged killer whale seemed to try to avoid further exposure to the 
sound field by the following behaviors: immediately swimming away 
(horizontally) from the source of the sound; engaging in a series of 
erratic and frequently deep dives that seemed to take it below the 
sound field;

[[Page 53669]]

or swimming away while engaged in a series of erratic and frequently 
deep dives. Although the sample sizes in this study are too small to 
support statistical analysis, the behavioral responses of the orcas 
were consistent with the results of other studies.
    In 2007, the first in a series of behavioral response studies, a 
collaboration by the Navy, NMFS, and other scientists showed one beaked 
whale (Mesoplodon densirostris) responding to an MFAS playback. Tyack 
et al. (2011) indicates that the playback began when the tagged beaked 
whale was vocalizing at depth (at the deepest part of a typical feeding 
dive), following a previous control with no sound exposure. The whale 
appeared to stop clicking significantly earlier than usual, when 
exposed to mid-frequency signals in the 130-140 dB (rms) received level 
range. After a few more minutes of the playback, when the received 
level reached a maximum of 140-150 dB, the whale ascended on the slow 
side of normal ascent rates with a longer than normal ascent, at which 
point the exposure was terminated. The results are from a single 
experiment and a greater sample size is needed before robust and 
definitive conclusions can be drawn.
    Tyack et al. (2011) also indicates that Blainville's beaked whales 
appear to be sensitive to noise at levels well below expected TTS (~160 
dB re 1 [micro]Pa). This sensitivity is manifest by an adaptive 
movement away from a sound source. This response was observed 
irrespective of whether the signal transmitted was within the band 
width of MFAS, which suggests that beaked whales may not respond to the 
specific sound signatures. Instead, they may be sensitive to any pulsed 
sound from a point source in this frequency range. The response to such 
stimuli appears to involve maximizing the distance from the sound 
source.
    Stimpert et al. (2014) tagged a Baird's beaked whale, which was 
subsequently exposed to simulated mid-frequency sonar. Changes in the 
animal's dive behavior and locomotion were observed when received level 
reached 127 dB re 1 [mu]Pa.
    Results from a 2007-2008 study conducted near the Bahamas showed a 
change in diving behavior of an adult Blainville's beaked whale to 
playback of mid-frequency source and predator sounds (Boyd et al., 
2008; Southall et al. 2009; Tyack et al., 2011). Reaction to mid-
frequency sounds included premature cessation of clicking and 
termination of a foraging dive, and a slower ascent rate to the 
surface. Results from a similar behavioral response study in southern 
California waters have been presented for the 2010-2011 field season 
(Southall et al. 2011; DeRuiter et al., 2013b). DeRuiter et al. (2013b) 
presented results from two Cuvier's beaked whales that were tagged and 
exposed to simulated mid-frequency active sonar during the 2010 and 
2011 field seasons of the southern California behavioral response 
study. The 2011 whale was also incidentally exposed to mid-frequency 
active sonar from a distant naval exercise. Received levels from the 
mid-frequency active sonar signals from the controlled and incidental 
exposures were calculated as 84-144 and 78-106 dB re 1 [micro]Pa root 
mean square (rms), respectively. Both whales showed responses to the 
controlled exposures, ranging from initial orientation changes to 
avoidance responses characterized by energetic fluking and swimming 
away from the source. However, the authors did not detect similar 
responses to incidental exposure to distant naval sonar exercises at 
comparable received levels, indicating that context of the exposures 
(e.g., source proximity, controlled source ramp-up) may have been a 
significant factor. Cuvier's beaked whale responses suggested 
particular sensitivity to sound exposure as consistent with results for 
Blainville's beaked whale. Similarly, beaked whales exposed to sonar 
during British training exercises stopped foraging (DSTL, 2007), and 
preliminary results of controlled playback of sonar may indicate 
feeding/foraging disruption of killer whales and sperm whales (Miller 
et al., 2011).
    In the 2007-2008 Bahamas study, playback sounds of a potential 
predator--a killer whale--resulted in a similar but more pronounced 
reaction, which included longer inter-dive intervals and a sustained 
straight-line departure of more than 20 km from the area. The authors 
noted, however, that the magnified reaction to the predator sounds 
could represent a cumulative effect of exposure to the two sound types 
since killer whale playback began approximately 2 hours after mid-
frequency source playback. Pilot whales and killer whales off Norway 
also exhibited horizontal avoidance of a transducer with outputs in the 
mid-frequency range (signals in the 1-2 kHz and 6-7 kHz ranges) (Miller 
et al., 2011). Additionally, separation of a calf from its group during 
exposure to mid-frequency sonar playback was observed on one occasion 
(Miller et al., 2011). In contrast, preliminary analyses suggest that 
none of the pilot whales or false killer whales in the Bahamas showed 
an avoidance response to controlled exposure playbacks (Southall et 
al., 2009).
    Through analysis of the behavioral response studies, a preliminary 
overarching effect of greater sensitivity to all anthropogenic 
exposures was seen in beaked whales compared to the other odontocetes 
studied (Southall et al., 2009). Therefore, recent studies have focused 
specifically on beaked whale responses to active sonar transmissions or 
controlled exposure playback of simulated sonar on various military 
ranges (Defence Science and Technology Laboratory, 2007; Claridge and 
Durban, 2009; Moretti et al., 2009; McCarthy et al., 2011; Tyack et 
al., 2011). In the Bahamas, Blainville's beaked whales located on the 
range will move off-range during sonar use and return only after the 
sonar transmissions have stopped, sometimes taking several days to do 
so (Claridge and Durban 2009; Moretti et al., 2009; McCarthy et al., 
2011; Tyack et al., 2011). Moretti et al. (2014) used recordings from 
seafloor-mounted hydrophones at the Atlantic Undersea Test and 
Evaluation Center (AUTEC) to analyze the probability of Blainsville's 
beaked whale dives before, during, and after Navy sonar exercises.
    Orientation--A shift in an animal's resting state or an attentional 
change via an orienting response represent behaviors that would be 
considered mild disruptions if occurring alone. As previously 
mentioned, the responses may co-occur with other behaviors; for 
instance, an animal may initially orient toward a sound source, and 
then move away from it. Thus, any orienting response should be 
considered in context of other reactions that may occur.

Behavioral Responses

    Southall et al. (2007) reports the results of the efforts of a 
panel of experts in acoustic research from behavioral, physiological, 
and physical disciplines that convened and reviewed the available 
literature on marine mammal hearing and physiological and behavioral 
responses to human-made sound with the goal of proposing exposure 
criteria for certain effects. This peer-reviewed compilation of 
literature is very valuable, though Southall et al. (2007) note that 
not all data are equal, some have poor statistical power, insufficient 
controls, and/or limited information on received levels, background 
noise, and other potentially important contextual variables--such data 
were reviewed and sometimes used for qualitative illustration but were 
not included in the quantitative analysis for the criteria 
recommendations. All of the

[[Page 53670]]

studies considered, however, contain an estimate of the received sound 
level when the animal exhibited the indicated response.
    In the Southall et al. (2007) publication, for the purposes of 
analyzing responses of marine mammals to anthropogenic sound and 
developing criteria, the authors differentiate between single pulse 
sounds, multiple pulse sounds, and non-pulse sounds. MFAS/HFAS sonar is 
considered a non-pulse sound. Southall et al. (2007) summarize the 
studies associated with low-frequency, mid-frequency, and high-
frequency cetacean and pinniped responses to non-pulse sounds, based 
strictly on received level, in Appendix C of their article 
(incorporated by reference and summarized in the three paragraphs 
below).
    The studies that address responses of low-frequency cetaceans to 
non-pulse sounds include data gathered in the field and related to 
several types of sound sources (of varying similarity to MFAS/HFAS) 
including: Vessel noise, drilling and machinery playback, low-frequency 
M-sequences (sine wave with multiple phase reversals) playback, 
tactical low-frequency active sonar playback, drill ships, Acoustic 
Thermometry of Ocean Climate (ATOC) source, and non-pulse playbacks. 
These studies generally indicate no (or very 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, though, contextual variables 
play a very important role in the reported responses and the severity 
of effects are not linear when compared to received level. Also, few of 
the laboratory or field datasets had common conditions, behavioral 
contexts or sound sources, so it is not surprising that responses 
differ.
    The studies that address responses of mid-frequency cetaceans to 
non-pulse sounds include data gathered both in the field and the 
laboratory and related to several different sound sources (of varying 
similarity to MFAS/HFAS) including: pingers, drilling playbacks, ship 
and ice-breaking noise, vessel noise, Acoustic Harassment Devices 
(AHDs), Acoustic Deterrent Devices (ADDs), MFAS, and non-pulse bands 
and tones. Southall et al. (2007) were unable to come to a clear 
conclusion regarding the results of these studies. In some cases, 
animals in the field showed significant responses to received levels 
between 90 and 120 dB, while in other cases these responses were not 
seen in the 120 to 150 dB range. The disparity in results was likely 
due to contextual variation and the differences between the results in 
the field and laboratory data (animals typically responded at lower 
levels in the field).
    The studies that address responses of high frequency cetaceans to 
non-pulse sounds include data gathered both in the field and the 
laboratory and related to several different sound sources (of varying 
similarity to MFAS/HFAS) including: pingers, AHDs, and various 
laboratory non-pulse sounds. All of these data were collected from 
harbor porpoises. Southall et al. (2007) concluded that the existing 
data indicate that harbor porpoises are likely sensitive to a wide 
range of anthropogenic sounds at low received levels (~ 90 to 120 dB), 
at least for initial exposures. All recorded exposures above 140 dB 
induced profound and sustained avoidance behavior in wild harbor 
porpoises (Southall et al., 2007). Rapid habituation was noted in some 
but not all studies. There is no data to indicate whether other high 
frequency cetaceans are as sensitive to anthropogenic sound as harbor 
porpoises are.
    The studies that address the responses of pinnipeds in water to 
non-pulse sounds include data gathered both in the field and the 
laboratory and related to several different sound sources (of varying 
similarity to MFAS/HFAS) including: AHDs, ATOC, various non-pulse 
sounds used in underwater data communication; underwater drilling, and 
construction noise. Few studies exist with enough information to 
include them in the analysis. The limited data suggested that exposures 
to non-pulse sounds between 90 and 140 dB generally do not result in 
strong behavioral responses in pinnipeds in water, but no data exist at 
higher received levels.

Potential Effects of Behavioral Disturbance

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

[[Page 53671]]

success rate compared with geese in disturbed habitat (being 
consistently scared off the fields on which they were foraging) which 
did not gain mass and had a 17-percent reproductive success rate. 
Similar reductions in reproductive success have been reported for mule 
deer disturbed by all-terrain vehicles (Yarmoloy et al., 1988), caribou 
disturbed by seismic exploration blasts (Bradshaw et al., 1998), 
caribou disturbed by low-elevation military jet-fights (Luick et al., 
1996), and caribou disturbed by low-elevation jet flights (Harrington 
and Veitch, 1992). Similarly, a study of elk that were disturbed 
experimentally by pedestrians concluded that the ratio of young to 
mothers was inversely related to disturbance rate (Phillips and 
Alldredge, 2000).
    The primary mechanism by which increased vigilance and disturbance 
appear to affect the fitness of individual animals is by disrupting an 
animal's time budget and, as a result, reducing the time they might 
spend foraging and resting (which increases an animal's activity rate 
and energy demand). For example, a study of grizzly bears reported that 
bears disturbed by hikers reduced their energy intake by an average of 
12 kcal/minute (50.2 x 10\3\kJ/minute), and spent energy fleeing or 
acting aggressively toward hikers (White et al., 1999). Alternately, 
Ridgway et al. (2006) reported that increased vigilance in bottlenose 
dolphins exposed to sound over a 5-day period did not cause any sleep 
deprivation or stress effects such as changes in cortisol or 
epinephrine levels.
    Lusseau and Bejder (2007) present data from three long-term studies 
illustrating the connections between disturbance from whale-watching 
boats and population-level effects in cetaceans. In Sharks Bay 
Australia, the abundance of bottlenose dolphins was compared within 
adjacent control and tourism sites over three consecutive 4.5-year 
periods of increasing tourism levels. Between the second and third time 
periods, in which tourism doubled, dolphin abundance decreased by 15 
percent in the tourism area and did not change significantly in the 
control area. In Fiordland, New Zealand, two populations (Milford and 
Doubtful Sounds) of bottlenose dolphins with tourism levels that 
differed by a factor of seven were observed and significant increases 
in travelling time and decreases in resting time were documented for 
both. Consistent short-term avoidance strategies were observed in 
response to tour boats until a threshold of disturbance was reached 
(average 68 minutes between interactions), after which the response 
switched to a longer term habitat displacement strategy. For one 
population tourism only occurred in a part of the home range, however, 
tourism occurred throughout the home range of the Doubtful Sound 
population and once boat traffic increased beyond the 68-minute 
threshold (resulting in abandonment of their home range/preferred 
habitat), reproductive success drastically decreased (increased 
stillbirths) and abundance decreased significantly (from 67 to 56 
individuals in short period). Last, in a study of northern resident 
killer whales off Vancouver Island, exposure to boat traffic was shown 
to reduce foraging opportunities and increase traveling time. A simple 
bioenergetics model was applied to show that the reduced foraging 
opportunities equated to a decreased energy intake of 18 percent, while 
the increased traveling incurred an increased energy output of 3-4 
percent, which suggests that a management action based on avoiding 
interference with foraging might be particularly effective.
    On a related note, many animals perform vital functions, such as 
feeding, resting, traveling, and socializing, on a diel cycle (24-hour 
cycle). Substantive behavioral reactions to noise exposure (such as 
disruption of critical life functions, displacement, or avoidance of 
important habitat) are more likely to be significant if they last more 
than one diel cycle or recur on subsequent days (Southall et al., 
2007). Consequently, a behavioral response lasting less than 1 day and 
not recurring on subsequent days is not considered particularly severe 
unless it could directly affect reproduction or survival (Southall et 
al., 2007). Note that there is a difference between multiple-day 
substantive behavioral reactions and multiple-day anthropogenic 
activities. For example, just because an at-sea exercise lasts for 
multiple days does not necessarily mean that individual animals are 
either exposed to that exercise for multiple days or, further, exposed 
in a manner resulting in a sustained multiple day substantive 
behavioral responses.
    In order to understand how the effects of activities may or may not 
impact stocks and populations of marine mammals, it is necessary to 
understand not only what the likely disturbances are going to be, but 
how those disturbances may affect the reproductive success and 
survivorship of individuals, and then how those impacts to individuals 
translate to population changes. Following on the earlier work of a 
committee of the U.S. National Research Council (NRC, 2005), New et al. 
(2014), in an effort termed the Potential Consequences of Disturbance 
(PCoD), outline an updated conceptual model of the relationships 
linking disturbance to changes in behavior and physiology, health, 
vital rates, and population dynamics (below). As depicted, behavioral 
and physiological changes can either have direct (acute) effects on 
vital rates, such as when changes in habitat use or increased stress 
levels raise the probability of mother-calf separation or predation, or 
they can have indirect and long-term (chronic) effects on vital rates, 
such as when changes in time/energy budgets or increased disease 
susceptibility affect health, which then affects vital rates (New et 
al., 2014).
    In addition to outlining this general framework and compiling the 
relevant literature that supports it, New et al. (2014) have chosen 
four example species for which extensive long-term monitoring data 
exist (southern elephant seals, North Atlantic right whales, Ziphidae 
beaked whales, and bottlenose dolphins) and developed state-space 
energetic models that can be used to effectively forecast longer-term, 
population-level impacts from behavioral changes. While these are very 
specific models with very specific data requirements that cannot yet be 
applied broadly to project-specific risk assessments, they are a 
critical first step.

Vessels

    Commercial and Navy ship strikes of cetaceans can cause major 
wounds, which may lead to the death of the animal. An animal at the 
surface could be struck directly by a vessel, a surfacing animal could 
hit the bottom of a vessel, or an animal just below the surface could 
be cut by a vessel's propeller. The severity of injuries typically 
depends on the size and speed of the vessel (Knowlton and Kraus, 2001; 
Laist et al., 2001; Vanderlaan and Taggart, 2007).
    Marine mammals react to vessels in a variety of ways. Some respond 
negatively by retreating or engaging in antagonistic responses while 
other animals ignore the stimulus altogether (Terhune and Verboom, 
1999; Watkins, 1986). Silber et al. (2010) concludes that large whales 
that are in close proximity to a vessel may not regard the vessel as a 
threat, or may be involved in a vital activity (i.e., mating or 
feeding) which may not allow them to have a proper avoidance response. 
Cetacean species generally pay little attention to transiting vessel 
traffic as it approaches, although they may engage in last minute 
avoidance maneuvers (Laist et al., 2001). Baleen whale responses to 
vessel

[[Page 53672]]

traffic range from avoidance maneuvers to disinterest in the presence 
of vessels (Nowacek et al., 2007; Scheidat et al., 2004). Species of 
delphinids can vary widely in their reaction to vessels. Many exhibit 
mostly neutral behavior, but there are frequent instances of observed 
avoidance behaviors (Hewitt, 1985; W[uuml]rsig et al., 1998). Many 
species of odontocetes (e.g., bottlenose dolphin) are frequently 
observed bow riding or jumping in the wake of a vessel (Norris and 
Prescott, 1961; Ritter, 2002; Shane et al., 1986; W[uuml]rsig et al., 
1998).
    The most vulnerable marine mammals are those that spend extended 
periods of time at the surface in order to restore oxygen levels within 
their tissues after deep dives (e.g., the sperm whale). In addition, 
some baleen whales, such as the North Atlantic right whale, seem 
generally unresponsive to vessel sound, making them more susceptible to 
vessel collisions (Nowacek et al., 2004). These species are primarily 
large, slow moving whales. Smaller marine mammals (e.g., bottlenose 
dolphin) move quickly through the water column.
    An examination of all known ship strikes from all shipping sources 
(civilian and military) indicates vessel speed is a principal factor in 
whether a vessel strike results in death (Knowlton and Kraus, 2001; 
Laist et al., 2001; Jensen and Silber, 2003; Vanderlaan and Taggart, 
2007). In assessing records in which vessel speed was known, Laist et 
al. (2001) found a direct relationship between the occurrence of a 
whale strike and the speed of the vessel involved in the collision. The 
authors concluded that most deaths occurred when a vessel was traveling 
in excess of 13 knots.
    Jensen and Silber (2003) detailed 292 records of known or probable 
ship strikes of all large whale species from 1975 to 2002. Of these, 
vessel speed at the time of collision was reported for 58 cases. Of 
these cases, 39 (or 67 percent) resulted in serious injury or death (19 
of those resulted in serious injury as determined by blood in the 
water, propeller gashes or severed tailstock, and fractured skull, jaw, 
vertebrae, hemorrhaging, massive bruising or other injuries noted 
during necropsy and 20 resulted in death). Operating speeds of vessels 
that struck various species of large whales ranged from 2 to 51 knots. 
The majority (79 percent) of these strikes occurred at speeds of 13 
knots or greater. The average speed that resulted in serious injury or 
death was 18.6 knots. Pace and Silber (2005) found that the probability 
of death or serious injury increased rapidly with increasing vessel 
speed. Specifically, the predicted probability of serious injury or 
death increased from 45 to 75 percent as vessel speed increased from 10 
to 14 knots, and exceeded 90 percent at 17 knots. Higher speeds during 
collisions result in greater force of impact and also appear to 
increase the chance of severe injuries or death. While modeling studies 
have suggested that hydrodynamic forces pulling whales toward the 
vessel hull increase with increasing speed (Clyne, 1999; Knowlton et 
al., 1995), this is inconsistent with Silber et al. (2010), which 
demonstrated that there is no such relationship (i.e., hydrodynamic 
forces are independent of speed).
    The Jensen and Silber (2003) report notes that the database 
represents a minimum number of collisions, because the vast majority 
probably goes undetected or unreported. In contrast, Navy vessels are 
likely to detect any strike that does occur, and they are required to 
report all ship strikes involving marine mammals. Overall, the 
percentages of Navy traffic relative to overall large shipping traffic 
are very small (on the order of 2 percent).
    Other efforts have been undertaken to investigate the impact from 
vessels (both whale-watching and general vessel traffic noise) and 
demonstrated impacts do occur (Bain, 2002; Erbe, 2002; Lusseau, 2009; 
Williams et al., 2006, 2009, 2011b, 2013, 2014a, 2014b; Noren et al., 
2009; Read et al., 2014; Rolland et al., 2012; Pirotta et al., 2015). 
This body of research for the most part has investigated impacts 
associated with the presence of chronic stressors, which differ 
significantly from generally intermittent Navy training and testing 
activities. For example, in an analysis of energy costs to killer 
whales, Williams et al. (2009) suggested that whale-watching in the 
Johnstone Strait resulted in lost feeding opportunities due to vessel 
disturbance, which could carry higher costs than other measures of 
behavioral change might suggest. Ayres et al. (2012) recently reported 
on research in the Salish Sea involving the measurement of southern 
resident killer whale fecal hormones to assess two potential threats to 
the species recovery: Lack of prey (salmon) and impacts to behavior 
from vessel traffic. Ayres et al. (2012) suggested that the lack of 
prey overshadowed any population-level physiological impacts on 
southern resident killer whales from vessel traffic.
    The Navy's Draft EA for 2015 West Coast Civilian Port Defense 
training activities fully addressed the potential impacts of vessel 
movement on marine mammals in the Study Area. The Navy does not 
anticipate vessel strikes to marine mammals within the Study Area, nor 
were takes by injury or mortality resulting from vessel strike 
predicted in the Navy's analysis. Vessel strikes within the Study Area 
are highly unlikely due to the size, maneuverability, and speed of the 
surface mine countermeasure vessel (the AVENGER class ship would 
typically operate at speeds less than 10 knots (18 km/hour); the 
generally low likelihood of occurrence of large whales within the Study 
Area; the effectiveness of Navy lookouts; and the implementation of 
mitigation measures described below. Therefore, takes by injury or 
mortality resulting from vessel strikes are not authorized by NMFS in 
this proposed incidental harassment authorization. However, the Navy 
has proposed measures (see Proposed Mitigation) to mitigate potential 
impacts to marine mammals from vessel strike and other physical 
disturbance (towed in-water devices) during training activities in the 
Study Area.

Marine Mammal Habitat

    The primary source of potential marine mammal habitat impact is 
acoustic exposures resulting from mine detection and mine 
neutralization activities. However, the exposures do not constitute a 
long-term physical alteration of the water column or bottom topography, 
as the occurrences are of limited duration and intermittent in time.
    Marine mammal habitat and prey species may be temporarily impacted 
by acoustic sources associated with the proposed activities. The 
potential for acoustic sources to impact marine mammal habitat or prey 
species is discussed below.

Expected Effects on Habitat

    The effects of the introduction of sound into the environment are 
generally considered to have a lesser impact on marine mammal habitat 
than the physical alteration of the habitat. Acoustic exposures are not 
expected to result in long-term physical alteration of the water column 
or bottom topography, as the occurrences are of limited duration and 
intermittent in time. The proposed training activities will only occur 
during a two week period, and no military expended material would be 
left as a result of this event.
    The ambient underwater noise level within active shipping areas of 
Los Angeles/Long Beach has been estimated around 140 dB re 1 [mu]Pa 
(Tetra Tech Inc., 2011). Existing ambient acoustic levels in non-
shipping areas around Terminal Island in the Port of Long Beach ranged 
between 120 dB and 132 dB re 1 [mu]Pa (Tetra Tech Inc., 2011). 
Additional

[[Page 53673]]

vessel noise, aircraft noise, and underwater acoustics associated with 
the proposed training activities have the potential to temporarily 
increase the noise levels of the Study Area. However, with ambient 
levels of noise being elevated, the additional vessel noise would 
likely be masked by the existing environmental noise and marine species 
would not be impacted by the sound of the vessels or aircraft, but 
perhaps by the sight of an approaching vessel or the shadow of a 
helicopter.
    Noise generated from helicopters is transient in nature and 
variable in intensity. Helicopter sounds contain dominant tones from 
the rotors that are generally below 500 Hz. Helicopters often radiate 
more sound forward than aft. The underwater noise produced is generally 
brief when compared with the duration of audibility in the air. The 
sound pressure level from an H-60 helicopter hovering at a 50 ft (15 m) 
altitude would be approximately 125 dB re 1 [mu]Pa at 1 m below the 
water surface, which is lower than the ambient sound that has been 
estimated in and around the Ports of Los Angeles/Long Beach. Helicopter 
flights associated with the proposed activities could occur at 
altitudes as low as 75 to 100 ft (23 to 31 m), and typically last two 
to four hours.
    Mine warfare sonar employs high frequencies (above 10 kHz) that 
attenuate rapidly in the water, thus producing only a small area of 
potential auditory masking. Odontocetes and pinnipeds may experience 
some limited masking at closer ranges as the frequency band of many 
mine warfare sonar overlaps the hearing and vocalization abilities of 
some odontocetes and pinnipeds; however, the frequency band of the 
sonar is narrow, limiting the likelihood of auditory masking.
    The proposed training activities are of limited duration and 
dispersion of the activities in space and time reduce the potential for 
disturbance from ship-generated noise, helicopter noise, and acoustic 
transmissions from the proposed activities on marine mammals. The 
relatively high level of ambient noise in and near the busy shipping 
channels also reduces the potential for any impact on habitat from the 
addition of the platforms associated with the proposed activities.

Effects on Marine Mammal Prey

    Invertebrates--Marine invertebrates in the Study Area inhabit 
coastal waters and benthic habitats, including salt marshes, kelp 
forests, and soft sediments, canyons, and the continential shelf. The 
diverse range of species include oysters, crabs, worms, ghost shrimp, 
snails, sponges, sea fans, isopods, and stony corals (Chess and Hobson 
1997; Dugan et al. 2000; Proctor et al. 1980).
    Very little is known about sound detection and use of sound by 
aquatic invertebrates (Montgomery et al. 2006; Popper et al. 2001). 
Organisms may detect sound by sensing either the particle motion or 
pressure component of sound, or both. Aquatic invertebrates probably do 
not detect pressure since many are generally the same density as water 
and few, if any, have air cavities that would function like the fish 
swim bladder in responding to pressure (Popper et al. 2001). Many 
marine invertebrates, however, have ciliated ``hair'' cells that may be 
sensitive to water movements, such as those caused by currents or water 
particle motion very close to a sound source (Mackie and Singla 2003). 
These cilia may allow invertebrates to sense nearby prey or predators 
or help with local navigation. Marine invertebrates may produce and use 
sound in territorial behavior, to deter predators, to find a mate, and 
to pursue courtship (Popper et al. 2001).
    Both behavioral and auditory brainstem response studies suggest 
that crustaceans may sense sounds up to 3 kHz, but best sensitivity is 
likely below 200 Hz (Goodall et al. 1990; Lovell et al. 2005; Lovell et 
al. 2006). Most cephalopods (e.g., octopus and squid) likely sense low-
frequency sound below 1,000 Hz, with best sensitivities at lower 
frequencies (Mooney et al. 2010; Packard et al. 1990). A few 
cephalopods may sense higher frequencies up to 1,500 Hz (Hu et al. 
2009). Squid did not respond to toothed whale ultrasonic echolocation 
clicks at sound pressure levels ranging from 199 to 226 dB re 1 
microPascal peak-to-peak, likely because these clicks were outside of 
squid hearing range (Wilson et al. 2007). However, squid exhibited 
alarm responses when exposed to broadband sound from an approaching 
seismic airgun with received levels exceeding 145 to 150 dB re 1 
microPascal root mean square (McCauley et al. 2000).
    It is expected that most marine invertebrates would not sense high-
frequency sonar associated with the proposed activities. Most marine 
invertebrates would not be close enough to active sonar systems to 
potentially experience impacts to sensory structures. Any marine 
invertebrate capable of sensing sound may alter its behavior if exposed 
to sonar. Although acoustic transmissions produced during the proposed 
activities may briefly impact individuals, intermittent exposures to 
sonar are not expected to impact survival, growth, recruitment, or 
reproduction of widespread marine invertebrate populations.
    Fish--The portion of the California Bight in the vicinity of the 
Study Area is a transitional zone between cold and warm water masses, 
geographically separated by Point Conception, and is highly productive 
(Leet et al. 2001). The cold-water of the California Bight is rich in 
microscopic plankton (diatoms, krill, and other organisms), which form 
the base of the food chain in the Study Area. Small coastal pelagic 
fishes depend on this plankton and in turn are fed on by larger species 
(such as highly migratory species). The high fish diversity found in 
the Study Area occurs for several reasons: (1) The ranges of many 
temperate and tropical species extend into Southern California, (2) the 
area has complex bottom features and physical oceanographic features 
that include several water masses and a changeable marine climate 
offshore (Allen et al. 2006; Horn and Allen 1978), and (3) the islands 
and coastal areas provide a diversity of habitats that include soft 
bottom, rocky reefs, kelp beds, and estuaries, bays, and lagoons.
    All fish have two sensory systems to detect sound in the water: The 
inner ear, which functions very much like the inner ear in other 
vertebrates, and the lateral line, which consists of a series of 
receptors along the fish's body (Popper 2008). The inner ear generally 
detects relatively higher-frequency sounds, while the lateral line 
detects water motion at low frequencies (below a few hundred Hz) 
(Hastings and Popper 2005). Although hearing capability data only exist 
for fewer than 100 of the 32,000 fish species, current data suggest 
that most species of fish detect sounds from 50 to 1,000 Hz, with few 
fish hearing sounds above 4 kHz (Popper 2008). It is believed that most 
fish have their best hearing sensitivity from 100 to 400 Hz (Popper 
2003). Additionally, some clupeids (shad in the subfamily Alosinae) 
possess ultrasonic hearing (i.e., able to detect sounds above 100 kHz) 
(Astrup 1999). Permanent hearing loss, or PTS, has not been documented 
in fish. The sensory hair cells of the inner ear in fish can regenerate 
after they are damaged, unlike in mammals where sensory hair cells loss 
is permanent (Lombarte et al. 1993; Smith et al. 2006). As a 
consequence, any hearing loss in fish may be as temporary as the 
timeframe required to repair or replace the sensory cells that were 
damaged or destroyed (Smith et al. 2006).
    Potential direct injuries from acoustic transmissions are unlikely 
because of the relatively lower peak pressures and

[[Page 53674]]

slower rise times than potentially injurious sources such as 
explosives. Acoustic sources also lack the strong shock waves 
associated with an explosion. Therefore, direct injury is not likely to 
occur from exposure to sonar. Only a few fish species are able to 
detect high-frequency sonar and could have behavioral reactions or 
experience auditory masking during these activities. These effects are 
expected to be transient and long-term consequences for the population 
are not expected. Hearing specialists are not expected to be within the 
Study Area. If hearing specialists were present, they would have to in 
close vicinity to the source to experience effects from the acoustic 
transmission. While a large number of fish species may be able to 
detect low-frequency sonar, some mid-frequency sonar and other active 
acoustic sources, low-frequency and mid-frequency acoustic sources are 
not planned as part of the proposed activities. Overall effects to fish 
from active sonar sources would be localized, temporary and infrequent.
    Based on the detailed review within the Navy's EA for 2015 Civilian 
Port Defense training activities and the discussion above, there would 
be no effects to marine mammals resulting from loss or modification of 
marine mammal habitat or prey species related to the proposed 
activities.

Marine Mammal Avoidance

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

Effects of Habitat Impacts on Marine Mammals

    The proposed Civilian Port Defense training activities are not 
expected to have any habitat-related effects that cause significant or 
long-term consequences for individual marine mammals, their 
populations, or prey species. Based on the discussions above, there 
will be no loss or modification of marine mammal habitat and as a 
result no impacts to marine mammal populations.

Proposed Mitigation

    In order to issue an incidental take authorization under section 
101(a)(5)(A) and (D) of the MMPA, NMFS must set forth the ``permissible 
methods of taking pursuant to such activity, and other means of 
effecting the least practicable adverse impact on such species or stock 
and its habitat, paying particular attention to rookeries, mating 
grounds, and areas of similar significance.'' NMFS' duty under this 
``least practicable adverse impact'' standard is to prescribe 
mitigation reasonably designed to minimize, to the extent practicable, 
any adverse population-level impacts, as well as habitat impacts. While 
population-level impacts can be minimized by reducing impacts on 
individual marine mammals, not all takes translate to population-level 
impacts. NMFS' primary objective under the ``least practicable adverse 
impact'' standard is to design mitigation targeting those impacts on 
individual marine mammals that are most likely to lead to adverse 
population-level effects.
    The NDAA of 2004 amended the MMPA as it relates to military-
readiness activities and the ITA process such that ``least practicable 
adverse impact'' shall include consideration of personnel safety, 
practicality of implementation, and impact on the effectiveness of the 
``military readiness activity.'' The training activities described in 
the Navy's application are considered military readiness activities.
    NMFS reviewed the proposed activities and the proposed mitigation 
measures as described in the application to determine if they would 
result in the least practicable adverse effect on marine mammals, which 
includes a careful balancing of the likely benefit of any particular 
measure to the marine mammals with the likely effect of that measure on 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the ``military-readiness activity.'' Included below 
are the mitigation measures the Navy proposed in their application. 
NMFS worked with the Navy to develop these proposed measures, and they 
are informed by years of experience and monitoring.
    The Navy's proposed mitigation measures are modifications to the 
proposed activities that are implemented for the sole purpose of 
reducing a specific potential environmental impact on a particular 
resource. These do not include standard operating procedures, which are 
established for reasons other than environmental benefit. Most of the 
following proposed mitigation measures are currently, or were 
previously, implemented as a result of past environmental compliance 
documents. The Navy's overall approach to assessing potential 
mitigation measures is based on two principles: (1) Mitigation measures 
will be effective at reducing potential impacts on the resource, and 
(2) from a military perspective, the mitigation measures are 
practicable, executable, and safety and readiness will not be impacted.
    The mitigation measures applicable to the proposed Civilian Port 
Defense training activities are the same as those identified in the 
Mariana Islands Training and Testing Environmental Impact Statement/
Overseas Environmental Impact Statement (MITT EIS/OEIS), Chapter 5. All 
mitigation measures which could be applicable to the proposed 
activities are provided below. For the mitigation measures described 
below, the Lookout Procedures and Mitigation Zone Procedure sections 
from the MITT EIS/OEIS have been combined. For details regarding the 
methodology for analyzing each measure, see the MITT EIS/OEIS, Chapter 
5.

Lookout Procedure Measures

    The Navy will have two types of lookouts for the purposes of 
conducting visual observations: (1) Those positioned on surface ships, 
and (2) those positioned in aircraft or on boats. Lookouts positioned 
on surface ships will be dedicated solely to diligent observation of 
the air and surface of the water. They will have multiple observation 
objectives, which include but are not limited to detecting the presence 
of biological resources and recreational or fishing boats, observing 
mitigation zones, and monitoring for vessel and personnel safety 
concerns. Lookouts positioned on surface ships will typically be 
personnel already standing watch or existing members of the bridge 
watch team who become temporarily relieved of job responsibilities that 
would divert their attention from observing the air or surface of the 
water (such as navigation of a vessel).
    Due to aircraft and boat manning and space restrictions, Lookouts 
positioned in aircraft or on boats will consist of the aircraft crew, 
pilot, or boat crew. Lookouts positioned in aircraft and boats may 
necessarily be responsible for tasks in addition to observing the air 
or surface of the water (for example,

[[Page 53675]]

navigation of a helicopter or rigid hull inflatable boat). However, 
aircraft and boat lookouts will, to the maximum extent practicable and 
consistent with aircraft and boat safety and training requirements, 
comply with the observation objectives described above for Lookouts 
positioned on surface ships.

Mitigation Measures

High-Frequency Active Sonar

    The Navy will have one Lookout on ships or aircraft conducting 
high-frequency active sonar activities associated with mine warfare 
activities at sea.
    Mitigation will include visual observation from a vessel or 
aircraft (with the exception of platforms operating at high altitudes) 
immediately before and during active transmission within a mitigation 
zone of 200 yards (yds. [183 m]) from the active sonar source. If the 
source can be turned off during the activity, active transmission will 
cease if a marine mammal is sighted within the mitigation zone. Active 
transmission will recommence if any one of the following conditions is 
met: (1) The animal is observed exiting the mitigation zone, (2) the 
animal is thought to have exited the mitigation zone based on a 
determination of its course and speed and the relative motion between 
the animal and the source, (3) the mitigation zone has been clear from 
any additional sightings for a period of 10 minutes for an aircraft-
deployed source, (4) the mitigation zone has been clear from any 
additional sightings for a period of 30 minutes for a vessel-deployed 
source, (5) the vessel or aircraft has repositioned itself more than 
400 yds (366 m) away from the location of the last sighting, or (6) the 
vessel concludes that dolphins are deliberately closing in to ride the 
vessel's bow wave (and there are no other marine mammal sightings 
within the mitigation zone).

Physical Disturbance and Strike

    Although the Navy does not anticipate that any marine mammals would 
be struck during the conduct of Civilian Port Defense training 
activities, the mitigation measures below will be implemented and 
adhered to.
     Vessels--While underway, vessels will have a minimum of one 
Lookout. Vessels will avoid approaching marine mammals head on and will 
maneuver to maintain a mitigation zone of 500 yds (457 m) around 
observed whales, and 200 yds (183 m) around all other marine mammals 
(except bow riding dolphins), providing it is safe to do so.
     Towed In-Water Devices--The Navy will have one Lookout during 
activities using towed in-water devices when towed from a manned 
platform.
    The Navy will ensure that towed in-water devices being towed from 
manned platforms avoid coming within a mitigation zone of 250 yds (229 
m) around any observed marine mammal, providing it is safe to do so.

Mitigation Conclusions

    NMFS has carefully evaluated the Navy's proposed mitigation 
measures--many of which were developed with NMFS' input during previous 
Navy Training and Testing authorizations--and considered a range of 
other measures in the context of ensuring that NMFS prescribes the 
means of effecting the least practicable adverse impact on the affected 
marine mammal species and stocks and their habitat. Our evaluation of 
potential measures included consideration of the following factors in 
relation to one another: The manner in which, and the degree to which, 
the successful implementation of the mitigation measures is expected to 
reduce the likelihood and/or magnitude of adverse impacts to marine 
mammal species and stocks and their habitat; the proven or likely 
efficacy of the measures; and the practicability of the suite of 
measures for applicant implementation, including consideration of 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    Any mitigation measure(s) prescribed by NMFS should be able to 
accomplish, have a reasonable likelihood of accomplishing (based on 
current science), or contribute to accomplishing one or more of the 
general goals listed below:
    a. Avoid or minimize injury or death of marine mammals wherever 
possible (goals b, c, and d may contribute to this goal).
    b. Reduce the number of marine mammals (total number or number at 
biologically important time or location) exposed to received levels of 
MFAS/HFAS, underwater detonations, or other activities expected to 
result in the take of marine mammals (this goal may contribute to a, 
above, or to reducing harassment takes only).
    c. Reduce the number of times (total number or number at 
biologically important time or location) individuals would be exposed 
to received levels of MFAS/HFAS, underwater detonations, or other 
activities expected to result in the take of marine mammals (this goal 
may contribute to a, above, or to reducing harassment takes only).
    d. Reduce the intensity of exposures (either total number or number 
at biologically important time or location) to received levels of MFAS/
HFAS, underwater detonations, or other activities expected to result in 
the take of marine mammals (this goal may contribute to a, above, or to 
reducing the severity of harassment takes only).
    e. Avoid or minimize adverse effects to marine mammal habitat, 
paying special attention to the food base, activities that block or 
limit passage to or from biologically important areas, permanent 
destruction of habitat, or temporary destruction/disturbance of habitat 
during a biologically important time.
    f. For monitoring directly related to mitigation--increase the 
probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation (shut-down zone, etc.).
    Based on our evaluation of the Navy's proposed measures, as well as 
other measures considered by NMFS, NMFS has determined preliminarily 
that the Navy's proposed mitigation measures are adequate means of 
effecting the least practicable adverse impacts on marine mammals 
species or stocks and their habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, while 
also considering personnel safety, practicality of implementation, and 
impact on the effectiveness of the military readiness activity.
    The proposed IHA comment period provides the public an opportunity 
to submit recommendations, views, and/or concerns regarding this action 
and the proposed mitigation measures. While NMFS has determined 
preliminarily that the Navy's proposed mitigation measures would effect 
the least practicable adverse impact on the affected species or stocks 
and their habitat, NMFS will consider all public comments to help 
inform our final decision. Consequently, the proposed mitigation 
measures may be refined, modified, removed, or added to prior to the 
issuance of the authorization based on public comments received, and 
where appropriate, further analysis of any additional mitigation 
measures.

Proposed Monitoring and Reporting

    Section 101(a)(5)(A) of the MMPA states that in order to issue an 
ITA for an activity, NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such taking.'' The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for LOAs 
must include the suggested means of

[[Page 53676]]

accomplishing the necessary monitoring and reporting that will result 
in increased knowledge of the species and of the level of taking or 
impacts on populations of marine mammals that are expected to be 
present.

Integrated Comprehensive Monitoring Program

    The U.S. Navy has coordinated with NMFS to develop an overarching 
program plan in which specific monitoring would occur. This plan is 
called the Integrated Comprehensive Monitoring Program (ICMP) (U.S. 
Department of the Navy, 2011). The ICMP has been developed in direct 
response to Navy permitting requirements established in various MMPA 
Final Rules, Endangered Species Act consultations, Biological Opinions, 
and applicable regulations. As a framework document, the ICMP applies 
by regulation to those activities on ranges and operating areas for 
which the Navy is seeking or has sought incidental take authorizations. 
The ICMP is intended to coordinate monitoring efforts across all 
regions and to allocate the most appropriate level and type of effort 
based on set of standardized research goals, and in acknowledgement of 
regional scientific value and resource availability.
    The ICMP is designed to be a flexible, scalable, and adjustable 
plan. The ICMP is evaluated annually through the adaptive management 
process to assess progress, provide a matrix of goals for the following 
year, and make recommendations for refinement. Future monitoring will 
address the following ICMP top-level goals through a series of regional 
and ocean basin study questions with a priority study and funding focus 
on species of interest as identified for each range complex.
     An increase in our understanding of the likely occurrence 
of marine mammals and/or ESA-listed marine species in the vicinity of 
the action (i.e., presence, abundance, distribution, and/or density of 
species);
     An increase in our understanding of the nature, scope, or 
context of the likely exposure of marine mammals and/or ESA-listed 
species to any of the potential stressor(s) associated with the action 
(e.g., tonal and impulsive sound), through better understanding of one 
or more of the following: (1) The action and the environment in which 
it occurs (e.g., sound source characterization, propagation, and 
ambient noise levels); (2) the affected species (e.g., life history or 
dive patterns); (3) the likely co-occurrence of marine mammals and/or 
ESA-listed marine species with the action (in whole or part) associated 
with specific adverse effects, and/or; (4) the likely biological or 
behavioral context of exposure to the stressor for the marine mammal 
and/or ESA-listed marine species (e.g., age class of exposed animals or 
known pupping, calving or feeding areas);
     An increase in our understanding of how individual marine 
mammals or ESA-listed marine species respond (behaviorally or 
physiologically) to the specific stressors associated with the action 
(in specific contexts, where possible, e.g., at what distance or 
received level);
     An increase in our understanding of how anticipated 
individual responses, to individual stressors or anticipated 
combinations of stressors, may impact either: (1) The long-term fitness 
and survival of an individual; or (2) the population, species, or stock 
(e.g., through effects on annual rates of recruitment or survival);
     An increase in our understanding of the effectiveness of 
mitigation and monitoring measures;
     A better understanding and record of the manner in which 
the authorized entity complies with the ITA and Incidental Take 
Statement;
     An increase in the probability of detecting marine mammals 
(through improved technology or methods), both specifically within the 
safety zone (thus allowing for more effective implementation of the 
mitigation) and in general, to better achieve the above goals; and
     A reduction in the adverse impact of activities to the 
least practicable level, as defined in the MMPA.
    The ICMP will also address relative investments to different range 
complexes based on goals across all range complexes, and monitoring 
will leverage multiple techniques for data acquisition and analysis 
whenever possible. Because the ICMP does not specify actual monitoring 
field work or projects in a given area, it allows the Navy to 
coordinate its monitoring to gather the best scientific data possible 
across all areas in which the Navy operates. Details of the ICMP are 
available online (https://www.navymarinespeciesmonitoring.us/).

Strategic Planning Process for Marine Species Monitoring

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

Reporting

    In order to issue an incidental take authorization for an activity, 
section 101(a)(5)(A) and (D) of the MMPA states that NMFS must set 
forth ``requirements pertaining to the monitoring and reporting of such 
taking.'' Effective reporting is critical both to compliance as well as 
ensuring that the most value is obtained from the required monitoring. 
Some of the reporting requirements are still in development and the 
final authorization may contain additional details not contained here. 
Additionally, proposed reporting requirements may be modified, removed, 
or added based on information or comments received during the public 
comment period. Reports from individual monitoring events, results of 
analyses, publications, and periodic progress reports for specific 
monitoring projects would be posted to the Navy's Marine Species 
Monitoring Web portal: https://www.navymarinespeciesmonitoring.us.
    General Notification of Injured or Dead Marine Mammals--If any 
injury or death of a marine mammal is observed during the Civilian Port 
Defense training activities, the Navy will immediately halt the 
activity and report the incident to NMFS following the standard 
monitoring and reporting measures consistent with the MITT EIS/OEIS. 
The reporting measures include the following procedures:
    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 activity 
utilizing high-frequency active sonar. The Navy shall provide NMFS with 
species or description of the animal(s),

[[Page 53677]]

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 Navy shall consult 
the Stranding Response and Communication Plan to obtain more specific 
reporting requirements for specific circumstances.
    Vessel Strike--Vessel strike during Navy Civilian Port Defense 
activities in the Study Area is not anticipated; however, in the event 
that a Navy vessel strikes a whale, the Navy shall do the following:
    Immediately report to NMFS (pursuant to the established 
Communication Protocol) the:
     Species identification (if known);
     Location (latitude/longitude) of the animal (or location 
of the strike if the animal has disappeared);
     Whether the animal is alive or dead (or unknown); and
     The time of the strike.
    As soon as feasible, the Navy shall report to or provide to NMFS, 
the:
     Size, length, and description (critical if species is not 
known) of animal;
     An estimate of the injury status (e.g., dead, injured but 
alive, injured and moving, blood or tissue observed in the water, 
status unknown, disappeared, etc.);
     Description of the behavior of the whale during event, 
immediately after the strike, and following the strike (until the 
report is made or the animal is no longer sighted);
     Vessel class/type and operational status;
     Vessel length;
     Vessel speed and heading; and
     To the best extent possible, obtain a photo or video of 
the struck animal, if the animal is still in view.
    Within 2 weeks of the strike, provide NMFS:
     A detailed description of the specific actions of the 
vessel in the 30-minute timeframe immediately preceding the strike, 
during the event, and immediately after the strike (e.g., the speed and 
changes in speed, the direction and changes in direction, other 
maneuvers, sonar use, etc., if not classified);
     A narrative description of marine mammal sightings during 
the event and immediately after, and any information as to sightings 
prior to the strike, if available; and use established Navy shipboard 
procedures to make a camera available to attempt to capture photographs 
following a ship strike.
    NMFS and the Navy will coordinate to determine the services the 
Navy may provide to assist NMFS with the investigation of the strike. 
The response and support activities to be provided by the Navy are 
dependent on resource availability, must be consistent with military 
security, and must be logistically feasible without compromising Navy 
personnel safety. Assistance requested and provided may vary based on 
distance of strike from shore, the nature of the vessel that hit the 
whale, available nearby Navy resources, operational and installation 
commitments, or other factors.

Estimated Take by Incidental Harassment

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

Definition of Harassment

    As mentioned previously, with respect to military readiness 
activities, section 3(18)(B) of the MMPA defines ``harassment'' as: 
``(i) any act that injures or has the significant potential to injure a 
marine mammal or marine mammal stock in the wild [Level A Harassment]; 
or (ii) any act that disturbs or is likely to disturb a marine mammal 
or marine mammal stock in the wild by causing disruption of natural 
behavioral patterns, including, but not limited to, migration, 
surfacing, nursing, breeding, feeding, or sheltering, to a point where 
such behavioral patterns are abandoned or significantly altered [Level 
B Harassment].'' It is important to note that, as Level B harassment is 
interpreted here and quantified by the behavioral thresholds described 
below, the fact that a single behavioral pattern (of unspecified 
duration) is abandoned or significantly altered and classified as a 
Level B take does not mean, necessarily, that the fitness of the 
harassed individual is affected either at all or significantly, or 
that, for example, a preferred habitat area is abandoned. Further 
analysis of context and duration of likely exposures and effects is 
necessary to determine the impacts of the estimated effects on 
individuals and how those may translate to population level impacts, 
and is included in the Analysis and Negligible Impact Determination.

Level B Harassment

    Of the potential effects that were described earlier in this 
document, the following are the types of effects that fall into the 
Level B harassment category:
    Behavioral Harassment--Behavioral disturbance that rises to the 
level described in the definition above, when resulting from exposures 
to non-impulsive or impulsive sound, is considered Level B harassment. 
Some of the lower level physiological stress responses discussed 
earlier would also likely co-occur with the predicted harassments, 
although these responses are more difficult to detect and fewer data 
exist relating these responses to specific received levels of sound. 
When Level B harassment is predicted based on estimated behavioral 
responses, those takes may have a stress-related physiological 
component as well.
    As the statutory definition is currently applied, a wide range of 
behavioral reactions may qualify as Level B harassment under the MMPA, 
including but not limited to avoidance of the sound source, temporary 
changes in vocalizations or dive patters, temporary avoidance of an 
area, or temporary disruption of feeding, migrating, or reproductive 
behaviors. The estimates calculated by the Navy using the acoustic 
thresholds do not differentiate between the different types of 
potential behavioral reactions. Nor do the

[[Page 53678]]

estimates provide information regarding the potential fitness or other 
biological consequences of the reactions on the affected individuals. 
We therefore consider the available scientific evidence to determine 
the likely nature of the modeled behavioral responses and the potential 
fitness consequences for affected individuals.
    Temporary Threshold Shift (TTS)--As discussed previously, TTS can 
affect how an animal behaves in response to the environment, including 
conspecifics, predators, and prey. The following physiological 
mechanisms are thought to play a role in inducing auditory fatigue: 
Effects to sensory hair cells in the inner ear that reduce their 
sensitivity, modification of the chemical environment within the 
sensory cells; residual muscular activity in the middle ear, 
displacement of certain inner ear membranes; increased blood flow; and 
post-stimulatory reduction in both efferent and sensory neural output. 
Ward (1997) suggested that when these effects result in TTS rather than 
PTS, they are within the normal bounds of physiological variability and 
tolerance and do not represent a physical injury. Additionally, 
Southall et al. (2007) indicate that although PTS is a tissue injury, 
TTS is not because the reduced hearing sensitivity following exposure 
to intense sound results primarily from fatigue, not loss, of cochlear 
hair cells and supporting structures and is reversible. Accordingly, 
NMFS classifies TTS (when resulting from exposure to sonar and other 
active acoustic sources and explosives and other impulsive sources) as 
Level B harassment, not Level A harassment (injury).

Level A Harassment

    Of the potential effects that were described earlier, the types of 
effects that can fall into the Level A harassment category (unless they 
further rise to the level of serious injury or mortality) include 
permanent threshold shift (PTS), tissue damage due to acoustically 
mediated bubble growth, tissue damage due to behaviorally mediated 
bubble growth, physical disruption of tissues resulting from explosive 
shock wave, and vessel strike and other physical disturbance (strike 
from towed in-water devices). Level A harassment and mortality are not 
anticipated to result from any of the proposed Civilian Port Defense 
activities; therefore, these effects will not be discussed further. 
Although the Navy does not anticipate that any marine mammals would be 
struck during proposed Civilian Port Defense activities, the mitigation 
measures described above in Proposed Mitigation will be implemented and 
adhered to.

Criteria and Thresholds for Predicting Acoustic Impacts

    Criteria and thresholds used for determining the potential effects 
from the Civilian Port Defense activities are consistent with those 
used in the Navy's Phase II Training and Testing EISs (e.g., HSTT, 
MITT). Table 3 below provides the criteria and thresholds used in this 
analysis for estimating quantitative acoustic exposures of marine 
mammals from the proposed training activities. Weighting criteria are 
shown in the table below. Southall et al. (2007) proposed frequency-
weighting to account for the frequency bandwidth of hearing in marine 
mammals. Frequency-weighting functions are used to adjust the received 
sound level based on the sensitivity of the animal to the frequency of 
the sound. Details regarding these criteria and thresholds can be found 
in Finneran and Jenkins (2012).

            Table 3--Injury (PTS) and Disturbance (TTS, Behavioral) Thresholds for Underwater Sounds
----------------------------------------------------------------------------------------------------------------
                                                                                    Physiological criteria
             Group                     Species          Behavioral criteria  -----------------------------------
                                                                                  Onset TTS         Onset PTS
----------------------------------------------------------------------------------------------------------------
Low-Frequency Cetaceans.......  All mysticetes.......  Mysticete Dose         178 dB Sound      198 dB SEL (Type
                                                        Function (Type I       Exposure Level    II weighted).
                                                        weighted).             (SEL) \1\ (Type
                                                                               II weighted).
Mid-Frequency Cetaceans.......  Most delphinids,       Odontocete Dose        178 dB SEL (Type  198 dB SEL (Type
                                 beaked whales,         Function (Type I       II weighted).     II weighted).
                                 medium and large       weighted).
                                 toothed whales.
High-Frequency Cetaceans......  Porpoises, River       Odontocete Dose        152 dB SEL (Type  172 dB SEL (Type
                                 dolphins,              Function (Type I       II weighted).     II weighted).
                                 Cephalorynchus spp.,   weighted).
                                 Kogia sp.
Harbor Porpoises..............  Harbor porpoises.....  120 dB SPL,            152 dB SEL (Type  172 dB SEL (Type
                                                        unweighted.            II weighted).     II weighted).
Beaked Whales.................  All Ziphiidae........  140 dB SPL,            178 dB SEL (Type  198 dB SEL (Type
                                                        unweighted.            II weighted).     II weighted).
Phocidae (in water)...........  Harbor, Bearded,       Odontocete Dose        183 dB SEL (Type  197 dB SEL (Type
                                 Hooded, Common,        Function (Type I       I weighted).      I weighted).
                                 Spotted, Ringed,       weighted).
                                 Baikal, Caspian,
                                 Harp, Ribbon, Gray
                                 seals, Monk,
                                 Elephant, Ross,
                                 Crabeater, Leopard,
                                 and Weddell seals.
Otariidae (in water)..........  Guadalupe fur seal,    Odontocete Dose        206 dB SEL (Type  220 dB SEL (Type
                                 Northern fur seal,     Function (Type I       I weighted).      I weighted).
                                 California sea lion,   weighted).
                                 Steller sea lion.
----------------------------------------------------------------------------------------------------------------

    As discussed earlier, factors other than received level (such as 
distance from or bearing to the sound source, context of animal at time 
of exposure) can affect the way that marine mammals respond; however, 
data to support a quantitative analysis of those (and other factors) do 
not currently exist. It is also worth specifically noting that while 
context is very important in marine mammal response, given otherwise 
equivalent context, the severity of a marine mammal behavioral response 
is also expected to increase with received level (Houser and Moore, 
2014). NMFS will continue to modify these criteria as new data become 
available and can be appropriately and effectively incorporated.

Marine Mammal Density Estimates

    A quantitative analysis of impacts on a species requires data on 
the abundance and distribution of the species population in the 
potentially impacted area. The most appropriate unit of metric for this 
type of analysis is density, which is described as the number of 
animals present per unit area.

[[Page 53679]]

    There is no single source of density data for every area, species, 
and season because of the fiscal costs, resources, and effort involved 
in NMFS providing enough survey coverage to sufficiently estimate 
density. Therefore, to characterize the marine species density for 
large areas such as the Study Area, the Navy needed to compile data 
from multiple sources. Each data source may use different methods to 
estimate density, of which, uncertainty in the estimate can be directly 
related to the method applied. To develop a database of marine species 
density estimates, the Navy, in consultation with NMFS experts, adopted 
a protocol to select the best available data sources (including 
habitat-based density models, line-transect analyses, and peer-reviewed 
published studies) based on species, area, and season (see the Navy's 
Pacific Marine Species Density Database Technical Report; U.S. 
Department of the Navy, 2012, 2014). The resulting Geographic 
Information System (GIS) database includes one single spatial and 
seasonal density value for every marine mammal present within the Study 
Area.
    The Navy Marine Species Density Database includes a compilation of 
the best available density data from several primary sources and 
published works including survey data from NMFS within the U.S. EEZ. 
NMFS is the primary agency responsible for estimating marine mammal and 
sea turtle density within the U.S. EEZ. NMFS publishes annual SARs for 
various regions of U.S. waters and covers all stocks of marine mammals 
within those waters. The majority of species that occur in the Study 
Area are covered by the Pacific Region Stock Assessment Report 
(Carretta et al., 2014). Other independent researchers often publish 
density data or research covering a particular marine mammal species, 
which is integrated into the NMFS SARs.
    For most cetacean species, abundance is estimated using line-
transect methods that employ a standard equation to derive densities 
based on sighting data collected from systematic ship or aerial 
surveys. More recently, habitat-based density models have been used 
effectively to model cetacean density as a function of environmental 
variables (e.g., Redfern et al., 2006; Barlow et al., 2009; Becker et 
al., 2010; Becker et al., 2012a; Becker et al., 2012b; Becker, 2012c; 
Forney et al., 2012). Where the data supports habitat based density 
modeling, the Navy's database uses those density predictions. Habitat-
based density models allow predictions of cetacean densities on a finer 
spatial scale than traditional line-transect analyses because cetacean 
densities are estimated as a continuous function of habitat variables 
(e.g., sea surface temperature, water depth). Within most of the 
world's oceans, however there have not been enough systematic surveys 
to allow for line-transect density estimation or the development of 
habitat models. To get an approximation of the cetacean species 
distribution and abundance for unsurveyed areas, in some cases it is 
appropriate to extrapolate data from areas with similar oceanic 
conditions where extensive survey data exist. Habitat Suitability 
Indexes or Relative Environmental Suitability have also been used in 
data-limited areas to estimate occurrence based on existing 
observations about a given species' presence and relationships between 
basic environmental conditions (Kaschner et al., 2006).
    Methods used to estimate pinniped at-sea density are generally 
quite different than those described above for cetaceans. Pinniped 
abundance is generally estimated via shore counts of animals at known 
rookeries and haulout sites. For example, for species such as the 
California sea lion, population estimates are based on counts of pups 
at the breeding sites (Carretta et al., 2014). However, this method is 
not appropriate for other species such as harbor seals, whose pups 
enter the water shortly after birth. Population estimates for these 
species are typically made by counting the number of seals ashore and 
applying correction factors based on the proportion of animals 
estimated to be in the water (Carretta et al., 2014). Population 
estimates for pinniped species that occur in the Study Area are 
provided in the Pacific Region Stock Assessment Report (Carretta et 
al., 2014). Translating these population estimates to in-water 
densities presents challenges because the percentage of seals or sea 
lions at sea compared to those on shore is species-specific and depends 
on gender, age class, time of year (molt and breeding/pupping seasons), 
foraging range, and for species such as harbor seal, time of day and 
tide level. These parameters were identified from the literature and 
used to establish correction factors which were then applied to 
estimate the proportion of pinnipeds that would be at sea within the 
Study Area for a given season.
    Density estimates for each species in the Study Area, and the 
sources for these estimates, are provided in Chapter 4 of the 
application and in the Navy's Pacific Marine Species Density Database 
Technical Report.

Quantitative Modeling To Estimate Take

    The Navy performed a quantitative analysis to estimate the number 
of mammals that could be exposed to the acoustic transmissions during 
the proposed Civilian Port Defense activities. Inputs to the 
quantitative analysis included marine mammal density estimates, marine 
mammal depth occurrence distributions (Watwood and Buonantony 2012), 
oceanographic and environmental data, marine mammal hearing data, and 
criteria and thresholds for levels of potential effects. The 
quantitative analysis consists of computer modeled estimates and a 
post-model analysis to determine the number of potential mortalities 
and harassments. The model calculates sound energy propagation from the 
proposed sonars, the sound received by animat (virtual animal) 
dosimeters representing marine mammals distributed in the area around 
the modeled activity, and whether the sound received by a marine mammal 
exceeds the thresholds for effects. The model estimates are then 
further analyzed to consider animal avoidance and implementation of 
mitigation measures, resulting in final estimates of effects due to the 
proposed training activities.
    The Navy developed a set of software tools and compiled data for 
estimating acoustic effects on marine mammals without consideration of 
behavioral avoidance or Navy's standard mitigations. These databases 
and tools collectively form the Navy Acoustic Effects Model (NAEMO). In 
NAEMO, animats (virtual animals) are distributed non-uniformly based on 
species-specific density, depth distribution, and group size 
information. Animats record energy received at their location in the 
water column. A fully three-dimensional environment is used for 
calculating sound propagation and animat exposure in NAEMO. Site-
specific bathymetry, sound speed profiles, wind speed, and bottom 
properties are incorporated into the propagation modeling process. 
NAEMO calculates the likely propagation for various levels of energy 
(sound or pressure) resulting from each source used during the training 
event.
    NAEMO then records the energy received by each animat within the 
energy footprint of the event and calculates the number of animats 
having received levels of energy exposures that fall within defined 
impact thresholds. Predicted effects on the animats within a scenario 
are then tallied and the highest order effect (based on severity of 
criteria; e.g., PTS over TTS) predicted for a given animat is assumed. 
Each

[[Page 53680]]

scenario or each 24-hour period for scenarios lasting greater than 24 
hours is independent of all others, and therefore, the same individual 
marine animal could be impacted during each independent scenario or 24-
hour period. In few instances, although the activities themselves all 
occur within the Study Area, sound may propagate beyond the boundary of 
the Study Area. Any exposures occurring outside the boundary of the 
Study Area are counted as if they occurred within the Study Area 
boundary. NAEMO provides the initial estimated impacts on marine 
species with a static horizontal distribution. These model-estimated 
results are then further analyzed to account for pre-activity avoidance 
by sensitive species, mitigation (considering sound source and 
platform), and avoidance of repeated sound exposures by marine mammals, 
producing the final predictions of effects used in this request for an 
IHA.
    There are limitations to the data used in the acoustic effects 
model, and the results must be interpreted within these context. While 
the most accurate data and input assumptions have been used in the 
modeling, when there is a lack of definitive data to support an aspect 
of the modeling, modeling assumptions believed to overestimate the 
number of exposures have been chosen:
     Animats are modeled as being underwater, stationary, and 
facing the source and therefore always predicted to receive the maximum 
sound level (i.e., no porpoising or pinnipeds' heads above water). Some 
odontocetes have been shown to have directional hearing, with best 
hearing sensitivity facing a sound source and higher hearing thresholds 
for sounds propagating towards the rear or side of an animal (Kastelein 
et al. 2005; Mooney et al. 2008; Popov and Supin 2009).
     Animats do not move horizontally (but change their 
position vertically within the water column), which may overestimate 
physiological effects such as hearing loss, especially for slow moving 
or stationary sound sources in the model.
     Animats are stationary horizontally and therefore do not 
avoid the sound source, unlike in the wild where animals would most 
often avoid exposures at higher sound levels, especially those 
exposures that may result in PTS.
     Multiple exposures within any 24-hour period are 
considered one continuous exposure for the purposes of calculating the 
temporary or permanent hearing loss, because there are not sufficient 
data to estimate a hearing recovery function for the time between 
exposures.
     Mitigation measures that are implemented were not 
considered in the model. In reality, sound-producing activities would 
be reduced, stopped, or delayed if marine mammals are detected within 
the mitigation zones around sound sources.
    Because of these inherent model limitations and simplifications, 
model-estimated results must be further analyzed, considering such 
factors as the range to specific effects, avoidance, and the likelihood 
of successfully implementing mitigation measures, in order to determine 
the final estimate of potential takes.

Impacts on Marine Mammals

    Range to Effects--Table 4 provides range to effects for active 
acoustic sources to specific criteria determined using NAEMO. Marine 
mammals within these ranges would be predicted to receive the 
associated effect. Range to effects is important information in not 
only predicting acoustic impacts, but also in verifying the accuracy of 
model results against real-world situations and determining adequate 
mitigation ranges to avoid higher level effects, especially 
physiological effects to marine mammals. Therefore, the ranges in Table 
4 provide realistic maximum distances over which the specific effects 
from the use of the AN/SQQ-32 high frequency sonar, the only acoustic 
source to be used in the proposed activities that requires quantitative 
analysis, would be possible.

Table 4--Maximum Range to Temporary Threshold Shift and Behavioral Effects From the AN/SQQ-32 in the Los Angeles/
                                              Long Beach Study Area
----------------------------------------------------------------------------------------------------------------
                                                   Range to effects cold season    Range to effects warm season
                                                                (m)                             (m)
                  Hearing group                  ---------------------------------------------------------------
                                                    Behavioral          TTS         Behavioral          TTS
----------------------------------------------------------------------------------------------------------------
Low Frequency Cetacean..........................           2,800             <50           1,900             <50
Mid-Frequency Cetacean..........................           3,550             <50           2,550             <50
High Frequency Cetacean.........................           3,550              95           2,550             195
Phocidae water..................................           3,450             <50           2,500             <50
Otariidae Odobenidae water......................           3,350             <50           2,200             <50
----------------------------------------------------------------------------------------------------------------

    Avoidance Behavior and Mitigation Measures--When sonar is active, 
exposure to increased sound pressure levels would likely involve 
individuals that are moving through the area during foraging trips. 
Pinnipeds may also be exposed enroute to haul-out sites. As discussed 
further in Chapter 7 of the application and in Analysis and Negligible 
Impact Determination below, if exposure were to occur, both pinnipeds 
and cetaceans could exhibit behavioral changes such as increased 
swimming speeds, increased surfacing time, or decreased foraging. Most 
likely, individuals affected by elevated underwater noise would move 
away from the sound source and be temporarily displaced from the 
proposed Study Area. Any effects experienced by individual marine 
mammals are anticipated to be limited to short-term disturbance of 
normal behavior, temporary displacement or disruption of animals which 
may occur near the proposed training activities. Therefore, the 
exposures requested are expected to have no more than a minor effect on 
individual animals and no adverse effect on the populations of these 
species.
    Results from the quantitative analysis should be regarded as 
conservative estimates that are strongly influenced by limited marine 
mammal population data. While the numbers generated from the 
quantitative analysis provide conservative overestimates of marine 
mammal exposures, the short duration, limited geographic extent of 
Civilian Port Defense training activities, and mitigation measures 
would further limit actual exposures.

Incidental Take Request

    The Navy's Draft EA for 2015 West Coast Civilian Port Defense 
training activities analyzed the following stressors for potential 
impacts to marine mammals:

[[Page 53681]]

 Acoustic (sonar sources, vessel noise, aircraft noise)
 Energy (electromagnetic devices and lasers)
 Physical disturbance and strikes (vessels, in-water devices, 
seafloor objects)
    NMFS and the Navy determined the only stressor that could 
potentially result in the incidental taking of marine mammals per the 
definition of MMPA harassment from the Civilian Port Defense activities 
within the Study Area is from acoustic transmissions related to high-
frequency sonar.
    The methods of incidental take associated with the acoustic 
transmissions from the proposed Civilian Port Defense are described 
within Chapter 2 of the application. Acoustic transmissions have the 
potential to temporarily disturb or displace marine mammals. 
Specifically, only underwater active transmissions may result in the 
``take'' in the form of Level B harassment.
    Level A harassment and mortality are not anticipated to result from 
any of the proposed Civilian Port Defense activities. Furthermore, Navy 
mitigation and monitoring measures will be implemented to further 
minimize the potential for Level B takes of marine mammals.
    A detailed analysis of effects due to marine mammal exposures to 
non-impulsive sources (i.e., active sonar) in the Study Area is 
presented in Chapter 6 of the application and in the Estimated Take by 
Incidental Harassment section of this proposed IHA. Based on the 
quantitative acoustic modeling and analysis described in Chapter 6 of 
the application, Table 5 summarizes the Navy's final take request the 
Civilian Port Defense training activities from October through November 
2015.

Table 5--Total Number of Exposures Modeled and Requested per Species for
                Civilian Port Defense Training Activities
------------------------------------------------------------------------
                                                           Percentage of
               Common name                 Level B takes    stock taken
                                             requested          (%)
------------------------------------------------------------------------
Long-beaked common dolphin..............               8           0.007
Short-beaked common dolphin.............             727           0.177
Risso's dolphin.........................              21           0.330
Pacific white-sided dolphin.............              40           0.149
Bottlenose dolphin coastal..............              48          14.985
Harbor seal.............................               8           0.026
California sea lion.....................              46           0.015
                                         -------------------------------
    Total...............................             898  ..............
------------------------------------------------------------------------

Analysis and Negligible Impact Determination

    Negligible impact is ``an impact resulting from the specified 
activity that cannot be reasonably expected to, and is not reasonably 
likely to, adversely affect the species or stock through effects on 
annual rates of recruitment or survival'' (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes, alone, is not 
enough information on which to base an impact determination, as the 
severity of harassment may vary greatly depending on the context and 
duration of the behavioral response, many of which would not be 
expected to have deleterious impacts on the fitness of any individuals. 
In determining whether the expected takes will have a negligible 
impact, in addition to considering estimates of the number of marine 
mammals that might be ``taken'', NMFS must consider other factors, such 
as the likely nature of any responses (their intensity, duration, 
etc.), the context of any responses (critical reproductive time or 
location, migration, etc.), as well as the number and nature (e.g., 
severity) of estimated Level A harassment takes, the number of 
estimated mortalities, and the status of the species.
    To avoid repetition, we provide some general analysis immediately 
below that applies to all the species listed in Table 5, given that 
some of the anticipated effects (or lack thereof) of the Navy's 
training activities on marine mammals are expected to be relatively 
similar in nature. However, below that, we break our analysis into 
species to provide more specific information related to the anticipated 
effects on individuals or where there is information about the status 
or structure of any species that would lead to a differing assessment 
of the effects on the population.

Behavioral Harassment

    As discussed previously in this document, marine mammals can 
respond to MFAS/HFAS in many different ways, a subset of which 
qualifies as harassment (see Behavioral Harassment). One thing that the 
Level B harassment take estimates do not take into account is the fact 
that most marine mammals will likely avoid strong sound sources to one 
extent or another. Although an animal that avoids the sound source will 
likely still be taken in some instances (such as if the avoidance 
results in a missed opportunity to feed, interruption of reproductive 
behaviors, etc.), in other cases avoidance may result in fewer 
instances of take than were estimated or in the takes resulting from 
exposure to a lower received level than was estimated, which could 
result in a less severe response. An animal's exposure to a higher 
received level is more likely to result in a behavioral response that 
is more likely to adversely affect the health of the animal.
    Specifically, given a range of behavioral responses that may be 
classified as Level B harassment, to the degree that higher received 
levels are expected to result in more severe behavioral responses, only 
a small percentage of the anticipated Level B harassment from Navy 
activities might necessarily be expected to potentially result in more 
severe responses, especially when the distance from the source at which 
the levels below are received is considered. Marine mammals are able to 
discern the distance of a given sound source, and given other equal 
factors (including received level), they have been reported to respond 
more to sounds that are closer (DeRuiter et al., 2013). Further, the 
estimated number of responses do not reflect either the duration or 
context of those anticipated responses, some of which will be of very 
short duration, and other factors should be considered

[[Page 53682]]

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

Diel Cycle

    As noted previously, many animals perform vital functions, such as 
feeding, resting, traveling, and socializing on a diel cycle (24-hour 
cycle). Behavioral reactions to noise exposure (when taking place in a 
biologically important context, such as disruption of critical life 
functions, displacement, or avoidance of important habitat) are more 
likely to be significant if they last more than one diel cycle or recur 
on subsequent days (Southall et al., 2007). Consequently, a behavioral 
response lasting less than one day and not recurring on subsequent days 
is not considered severe unless it could directly affect reproduction 
or survival (Southall et al., 2007). Note that there is a difference 
between multiple-day substantive behavioral reactions and multiple-day 
anthropogenic activities. For example, just because at-sea exercises 
last for multiple days does not necessarily mean that individual 
animals are either exposed to those exercises for multiple days or, 
further, exposed in a manner resulting in a sustained multiple day 
substantive behavioral response. Additionally, the Navy does not 
necessarily operate active sonar the entire time during an exercise. 
While it is certainly possible that these sorts of exercises could 
overlap with individual marine mammals multiple days in a row at levels 
above those anticipated to result in a take, because of the factors 
mentioned above, it is considered not to be likely for the majority of 
takes, does not mean that a behavioral response is necessarily 
sustained for multiple days, and still necessitates the consideration 
of likely duration and context to assess any effects on the 
individual's fitness.

TTS

    As mentioned previously, TTS can last from a few minutes to days, 
be of varying degree, and occur across various frequency bandwidths, 
all of which determine the severity of the impacts on the affected 
individual, which can range from minor to more severe. The TTS 
sustained by an animal is primarily classified by three 
characteristics:
    1. Frequency--Available data (of mid-frequency hearing specialists 
exposed to mid- or high-frequency sounds; Southall et al., 2007) 
suggest that most TTS occurs in the frequency range of the source up to 
one octave higher than the source (with the maximum TTS at \1/2\ octave 
above). The more powerful MF sources used have center frequencies 
between 3.5 and 8 kHz and the other unidentified MF sources are, by 
definition, less than 10 kHz, which suggests that TTS induced by any of 
these MF sources would be in a frequency band somewhere between 
approximately 2 and 20 kHz. There are fewer hours of HF source use and 
the sounds would attenuate more quickly, plus they have lower source 
levels, but if an animal were to incur TTS from these sources, it would 
cover a higher frequency range (sources are between 20 and 100 kHz, 
which means that TTS could range up to 200 kHz; however, HF systems are 
typically used less frequently and for shorter time periods than 
surface ship and aircraft MF systems, so TTS from these sources is even 
less likely).
    2. Degree of the shift (i.e., by how many dB the sensitivity of the 
hearing is reduced)--Generally, both the degree of TTS and the duration 
of TTS will be greater if the marine mammal is exposed to a higher 
level of energy (which would occur when the peak dB level is higher or 
the duration is longer). The threshold for the onset of TTS was 
discussed previously in this document. An animal would have to approach 
closer to the source or remain in the vicinity of the sound source 
appreciably longer to increase the received SEL, which would be 
difficult considering the Lookouts and the nominal speed of an active 
sonar vessel (10-15 knots). In the TTS studies, some using exposures of 
almost an hour in duration or up to 217 SEL, most of the TTS induced 
was 15 dB or less, though Finneran et al. (2007) induced 43 dB of TTS 
with a 64-second exposure to a 20 kHz source. However, MFAS emits a 
nominal ping every 50 seconds, and incurring those levels of TTS is 
highly unlikely.
    3. Duration of TTS (recovery time)--In the TTS laboratory studies, 
some using exposures of almost an hour in duration or up to 217 SEL, 
almost all individuals recovered within 1 day (or less, often in 
minutes), although in one study (Finneran et al., 2007), recovery took 
4 days.
    Based on the range of degree and duration of TTS reportedly induced 
by exposures to non-pulse sounds of energy higher than that to which 
free-swimming marine mammals in the field are likely to be exposed 
during MFAS/HFAS training exercises in the Study Area, it is unlikely 
that marine mammals would ever sustain a TTS from active sonar that 
alters their sensitivity by more than 20 dB for more than a few days 
(and any incident of TTS would likely be far less severe due to the 
short duration of the majority of the exercises and the speed of a 
typical vessel). Also, for the same reasons discussed in the Diel Cycle 
section, and because of the short distance within which animals would 
need to approach the sound source, it is unlikely that animals would be 
exposed to the levels necessary to induce TTS in subsequent time 
periods such that their recovery is impeded. Additionally, though the 
frequency range of TTS that marine mammals might sustain would overlap 
with some of the frequency ranges of their vocalization types, the 
frequency range of TTS from MFAS/HFAS (the source from which TTS would 
most likely be sustained because the higher source level and slower 
attenuation make it more likely that an animal would be exposed to a 
higher received level) would not usually span the entire frequency 
range of one vocalization type, much less span all types of 
vocalizations or other critical auditory cues. If impaired, marine 
mammals would typically be aware of their impairment and are sometimes 
able to implement behaviors to compensate (see Acoustic Masking or 
Communication Impairment section), though these compensations may incur 
energetic costs.

Acoustic Masking or Communication Impairment

    Masking only occurs during the time of the signal (and potential 
secondary arrivals of indirect rays), versus TTS, which continues 
beyond the duration of the signal. Standard MFAS/HFAS nominally pings 
every 50 seconds for hull-mounted sources. For the sources for which we 
know the pulse length, most are significantly shorter than hull-

[[Page 53683]]

mounted active sonar, on the order of several microseconds to tens of 
microseconds. For hull-mounted active sonar, though some of the 
vocalizations that marine mammals make are less than one second long, 
there is only a 1 in 50 chance that they would occur exactly when the 
ping was received, and when vocalizations are longer than one second, 
only parts of them are masked. Alternately, when the pulses are only 
several microseconds long, the majority of most animals' vocalizations 
would not be masked. Masking effects from MFAS/HFAS are expected to be 
minimal. If masking or communication impairment were to occur briefly, 
it would be in the frequency range of MFAS/HFAS, which overlaps with 
some marine mammal vocalizations; however, it would likely not mask the 
entirety of any particular vocalization, communication series, or other 
critical auditory cue, because the signal length, frequency, and duty 
cycle of the MFAS/HFAS signal does not perfectly mimic the 
characteristics of any marine mammal's vocalizations.

Important Marine Mammal Habitat

    No critical habitat for marine mammals species protected under the 
ESA has been designated in the Study Area. There are also no known 
specific breeding or calving areas for marine mammals within the Study 
Area.

Species-Specific Analysis

    Long-beaked Common Dolphin--Long-beaked common dolphins that may be 
found in the Study Area belong to the California stock (Carretta et 
al., 2014). The Navy's acoustic analysis (quantitative modeling) 
predicts that 8 instances of Level B harassment of long-beaked common 
dolphin may occur from active sonar in the Study Area during Civilian 
Port Defense training activities. These Level B takes are anticipated 
to be in the form of behavioral reactions (3) and TTS (5) and no 
injurious takes of long-beaked common dolphin are requested or proposed 
for authorization. Relative to population size, these activities are 
anticipated to result only in a limited number of level B harassment 
takes. When the numbers of behavioral takes are compared to the 
estimated stock abundance (stock abundance estimates are shown in Table 
1) and if one assumes that each take happens to a separate animal, less 
than 0.01 percent of the California stock of long-beaked common dolphin 
would be behaviorally harassed during proposed training activities.
    Behavioral reactions of marine mammals to sound are known to occur 
but are difficult to predict. Recent behavioral studies indicate that 
reactions to sounds, if any, are highly contextual and vary between 
species and individuals within a species (Moretti et al., 2010; 
Southall et al., 2011; Thompson et al., 2010; Tyack, 2009; Tyack et 
al., 2011). Behavioral responses can range from alerting, to changing 
their behavior or vocalizations, to avoiding the sound source by 
swimming away or diving (Richardson, 1995; Nowacek, 2007; Southall et 
al., 2007; Finneran and Jenkins, 2012). Long-beaked common dolphins 
generally travel in large pods and should be visible from a distance in 
order to implement mitigation measures and reduce potential impacts. 
Many of the recorded long-beaked common dolphin vocalizations overlap 
with the MFAS/HFAS TTS frequency range (2-20 kHz) (Moore and Ridgway, 
1995; Ketten, 1998); however, NMFS does not anticipate TTS of a serious 
degree or extended duration to occur as a result of exposure to MFAS/
HFAS. Recovery from a threshold shift (TTS) can take a few minutes to a 
few days, depending on the exposure duration, sound exposure level, and 
the magnitude of the initial shift, with larger threshold shifts and 
longer exposure durations requiring longer recovery times (Finneran et 
al., 2005; Mooney et al., 2009a; Mooney et al., 2009b; Finneran and 
Schlundt, 2010). Large threshold shifts are not anticipated for these 
activities because of the unlikelihood that animals will remain within 
the ensonified area at high levels for the duration necessary to induce 
larger threshold shifts. Threshold shifts do not necessarily affect all 
hearing frequencies equally, so some threshold shifts may not interfere 
with an animal's hearing of biologically relevant sounds.
    Overall, the number of predicted behavioral reactions is low and 
temporary behavioral reactions in long-beaked common dolphins are 
unlikely to cause long-term consequences for individual animals or the 
population. The Civilian Port Defense activities are not expected to 
occur in an area/time of specific importance for reproductive, feeding, 
or other known critical behaviors for long-beaked common dolphin. No 
evidence suggests any major reproductive differences in comparison to 
short-beaked common dolphins (Reeves et al., 2002). Short-beaked common 
dolphin gestation is approximately 11 to 11.5 months in duration 
(Danil, 2004; Murphy and Rogan, 2006) with most calves born from May to 
September (Murphy and Rogan, 2006). Therefore, calving would not occur 
during the Civilian Port Defense training timeframe. The California 
stock of long-beaked common dolphin is not depleted under the MMPA. 
Although there is no formal statistical trend analysis, over the last 
30 years sighting and stranding data shows an increasing trend of long-
beaked common dolphins in California waters (Carretta et al., 2014). 
Consequently, the activities are not expected to adversely impact 
annual rates of recruitment or survival of long-beaked common dolphin.
    Short-beaked Common Dolphin--Short-beaked common dolphins that may 
be found in the Study Area belong to the California/Washington/Oregon 
stock (Carretta et al., 2014). The Navy's acoustic analysis 
(quantitative modeling) predicts that 727 instances of Level B 
harassment of short-beaked common dolphin may occur from active sonar 
in the Study Area during Civilian Port Defense training activities. 
These Level B takes are anticipated to be in the form of behavioral 
reactions (422) and TTS (305) and no injurious takes of short-beaked 
common dolphin are requested or proposed for authorization. Relative to 
population size, these activities are anticipated to result only in a 
limited number of level B harassment takes. When the numbers of 
behavioral takes are compared to the estimated stock abundance (stock 
abundance estimates are shown in Table 1) and if one assumes that each 
take happens to a separate animal, less than 0.18 percent of the 
California/Washington/Oregon stock of short-beaked common dolphin would 
be behaviorally harassed during proposed training activities.
    Behavioral reactions of marine mammals to sound are known to occur 
but are difficult to predict. Recent behavioral studies indicate that 
reactions to sounds, if any, are highly contextual and vary between 
species and individuals within a species (Moretti et al., 2010; 
Southall et al., 2011; Thompson et al., 2010; Tyack, 2009; Tyack et 
al., 2011). Behavioral responses can range from alerting, to changing 
their behavior or vocalizations, to avoiding the sound source by 
swimming away or diving (Richardson, 1995; Nowacek, 2007; Southall et 
al., 2007; Finneran and Jenkins, 2012). Short-beaked common dolphins 
generally travel in large pods and should be visible from a distance in 
order to implement mitigation measures and reduce potential impacts. 
Many of the recorded short-beaked common dolphin vocalizations overlap 
with the MFAS/HFAS TTS frequency range (2-20 kHz) (Moore and Ridgway, 
1995;

[[Page 53684]]

Ketten, 1998); however, NMFS does not anticipate TTS of a serious 
degree or extended duration to occur as a result of exposure to MFAS/
HFAS. Recovery from a threshold shift (TTS) can take a few minutes to a 
few days, depending on the exposure duration, sound exposure level, and 
the magnitude of the initial shift, with larger threshold shifts and 
longer exposure durations requiring longer recovery times (Finneran et 
al., 2005; Mooney et al., 2009a; Mooney et al., 2009b; Finneran and 
Schlundt, 2010). Large threshold shifts are not anticipated for these 
activities because of the unlikelihood that animals will remain within 
the ensonified area at high levels for the duration necessary to induce 
larger threshold shifts. Threshold shifts do not necessarily affect all 
hearing frequencies equally, so some threshold shifts may not interfere 
with an animal's hearing of biologically relevant sounds.
    Overall, the number of predicted behavioral reactions is low and 
temporary behavioral reactions in short-beaked common dolphins are 
unlikely to cause long-term consequences for individual animals or the 
population. The Civilian Port Defense activities are not expected to 
occur in an area/time of specific importance for reproductive, feeding, 
or other known critical behaviors for long-beaked common dolphin. 
Short-beaked common dolphin gestation is approximately 11 to 11.5 
months in duration (Danil, 2004; Murphy and Rogan, 2006) with most 
calves born from May to September (Murphy and Rogan, 2006). Therefore, 
calving would not occur during the Civilian Port Defense training 
timeframe. The California/Washington/Oregon stock of short-beaked 
common dolphin is not depleted under the MMPA. Abundance off California 
has increased dramatically since the late 1970s, along with a smaller 
decrease in abundance in the eastern tropical Pacific, suggesting a 
large-scale northward shift in the distribution of this species in the 
eastern north Pacific (Forney and Barlow, 1998; Forney et al., 1995). 
Consequently, the activities are not expected to adversely impact 
annual rates of recruitment or survival of short-beaked common dolphin.
    Risso's Dolphin--Risso's dolphins that may be found in the Study 
Area belong to the California/Washington/Oregon stock (Carretta et al., 
2014). The Navy's acoustic analysis (quantitative modeling) predicts 
that 21 instances of Level B harassment of Risso's dolphin may occur 
from active sonar in the Study Area during Civilian Port Defense 
training activities. These Level B takes are anticipated to be in the 
form of behavioral reactions (16) and TTS (5) and no injurious takes of 
Risso's dolphin are requested or proposed for authorization. Relative 
to population size, these activities are anticipated to result only in 
a limited number of level B harassment takes. When the numbers of 
behavioral takes are compared to the estimated stock abundance (stock 
abundance estimates are shown in Table 1) and if one assumes that each 
take happens to a separate animal, approximately 0.33 percent of the 
California/Washington/Oregon stock of Risso's dolphin would be 
behaviorally harassed during proposed training activities.
    Behavioral reactions of marine mammals to sound are known to occur 
but are difficult to predict. Recent behavioral studies indicate that 
reactions to sounds, if any, are highly contextual and vary between 
species and individuals within a species (Moretti et al., 2010; 
Southall et al., 2011; Thompson et al., 2010; Tyack, 2009; Tyack et 
al., 2011). Behavioral responses can range from alerting, to changing 
their behavior or vocalizations, to avoiding the sound source by 
swimming away or diving (Richardson, 1995; Nowacek, 2007; Southall et 
al., 2007; Finneran and Jenkins, 2012). Risso's dolphins generally 
travel in large pods and should be visible from a distance in order to 
implement mitigation measures and reduce potential impacts. Many of the 
recorded Risso's dolphin vocalizations overlap with the MFAS/HFAS TTS 
frequency range (2-20 kHz) (Corkeron and Van Parijs 2001); however, 
NMFS does not anticipate TTS of a serious degree or extended duration 
to occur as a result of exposure to MFAS/HFAS. Recovery from a 
threshold shift (TTS) can take a few minutes to a few days, depending 
on the exposure duration, sound exposure level, and the magnitude of 
the initial shift, with larger threshold shifts and longer exposure 
durations requiring longer recovery times (Finneran et al., 2005; 
Mooney et al., 2009a; Mooney et al., 2009b; Finneran and Schlundt, 
2010). Large threshold shifts are not anticipated for these activities 
because of the unlikelihood that animals will remain within the 
ensonified area at high levels for the duration necessary to induce 
larger threshold shifts. Threshold shifts do not necessarily affect all 
hearing frequencies equally, so some threshold shifts may not interfere 
with an animal's hearing of biologically relevant sounds.
    Overall, the number of predicted behavioral reactions is low and 
temporary behavioral reactions in Risso's dolphins are unlikely to 
cause long-term consequences for individual animals or the population. 
The Civilian Port Defense activities are not expected to occur in an 
area/time of specific importance for reproductive, feeding, or other 
known critical behaviors for Risso's dolphin. The California/
Washington/Oregon stock of Risso's dolphin is not depleted under the 
MMPA. The distribution of Risso's dolphins throughout the region is 
highly variable, apparently in response to oceanographic changes 
(Forney and Barlow, 1998). The status of Risso's dolphins off 
California, Oregon and Washington relative to optimum sustainable 
population is not known, and there are insufficient data to evaluate 
potential trends in abundance. However, Civilian Port Defense training 
activities are not expected to adversely impact annual rates of 
recruitment or survival of Risso's dolphin for the reasons stated 
above.
    Pacific White-Sided Dolphin--Pacific white-sided dolphins that may 
be found in the Study Area belong to the California/Washington/Oregon 
stock (Carretta et al., 2014). The Navy's acoustic analysis 
(quantitative modeling) predicts that 40 instances of Level B 
harassment of Pacific white-sided dolphin may occur from active sonar 
in the Study Area during Civilian Port Defense training activities. 
These Level B takes are anticipated to be in the form of behavioral 
reactions (21) and TTS (19) and no injurious takes of Pacific white-
sided dolphin are requested or proposed for authorization. Relative to 
population size, these activities are anticipated to result only in a 
limited number of level B harassment takes. When the numbers of 
behavioral takes are compared to the estimated stock abundance (stock 
abundance estimates are shown in Table 1) and if one assumes that each 
take happens to a separate animal, less than 0.15 percent of the 
California/Washington/Oregon stock of Pacific white-sided dolphin would 
be behaviorally harassed during proposed training activities.
    Behavioral reactions of marine mammals to sound are known to occur 
but are difficult to predict. Recent behavioral studies indicate that 
reactions to sounds, if any, are highly contextual and vary between 
species and individuals within a species (Moretti et al., 2010; 
Southall et al., 2011; Thompson et al., 2010; Tyack, 2009; Tyack et 
al., 2011). Behavioral responses can range from alerting, to changing 
their behavior or vocalizations, to avoiding the sound source by 
swimming away or diving

[[Page 53685]]

(Richardson, 1995; Nowacek, 2007; Southall et al., 2007; Finneran and 
Jenkins, 2012). Pacific white-sided dolphins generally travel in large 
pods and should be visible from a distance in order to implement 
mitigation measures and reduce potential impacts. Many of the recorded 
Pacific white-sided dolphin vocalizations overlap with the MFAS/HFAS 
TTS frequency range (2-20 kHz); however, NMFS does not anticipate TTS 
of a serious degree or extended duration to occur as a result of 
exposure to MFAS/HFAS. Recovery from a threshold shift (TTS) can take a 
few minutes to a few days, depending on the exposure duration, sound 
exposure level, and the magnitude of the initial shift, with larger 
threshold shifts and longer exposure durations requiring longer 
recovery times (Finneran et al., 2005; Mooney et al., 2009a; Mooney et 
al., 2009b; Finneran and Schlundt, 2010). Large threshold shifts are 
not anticipated for these activities because of the unlikelihood that 
animals will remain within the ensonified area at high levels for the 
duration necessary to induce larger threshold shifts. Threshold shifts 
do not necessarily affect all hearing frequencies equally, so some 
threshold shifts may not interfere with an animal's hearing of 
biologically relevant sounds.
    Overall, the number of predicted behavioral reactions is low and 
temporary behavioral reactions in Pacific white-sided dolphins are 
unlikely to cause long-term consequences for individual animals or the 
population. The Civilian Port Defense activities are not expected to 
occur in an area/time of specific importance for reproductive, feeding, 
or other known critical behaviors for long-beaked common dolphin. 
Pacific white-sided dolphin calves are typically born in the summer 
months between April and early September (Black, 1994; NOAA, 2012; 
Reidenberg and Laitman, 2002). This species is predominantly located 
around the proposed Study Area in the colder winter months when neither 
mating nor calving is expected, as both occur off the coast of Oregon 
and Washington outside of the timeframe for the proposed activities 
(October through November). The California/Washington/Oregon stock of 
Pacific white-sided dolphin is not depleted under the MMPA. The stock 
is considered stable, with no indications of any positive or negative 
trends in abundance (NOAA, 2014). Consequently, the activities are not 
expected to adversely impact annual rates of recruitment or survival of 
Pacific white-sided dolphin.
    Bottlenose Dolphin--Bottlenose dolphins that may be found in the 
Study Area belong to the California Coastal stock (Carretta et al., 
2014). The Navy's acoustic analysis (quantitative modeling) predicts 
that 48 instances of Level B harassment of bottlenose dolphin may occur 
from active sonar in the Study Area during Civilian Port Defense 
training activities. These Level B takes are anticipated to be in the 
form of behavioral reactions (29) and TTS (19) and no injurious takes 
of bottlenose dolphin are requested or proposed for authorization. 
Relative to population size, these activities are anticipated to result 
only in a limited number of level B harassment takes. When the numbers 
of behavioral takes are compared to the estimated stock abundance 
(stock abundance estimates are shown in Table 1) and if one assumes 
that each take happens to a separate animal, less than 15 percent of 
the Coastal stock of bottlenose dolphin would be behaviorally harassed 
during proposed training activities.
    Behavioral reactions of marine mammals to sound are known to occur 
but are difficult to predict. Recent behavioral studies indicate that 
reactions to sounds, if any, are highly contextual and vary between 
species and individuals within a species (Moretti et al., 2010; 
Southall et al., 2011; Thompson et al., 2010; Tyack, 2009; Tyack et 
al., 2011). Behavioral responses can range from alerting, to changing 
their behavior or vocalizations, to avoiding the sound source by 
swimming away or diving (Richardson, 1995; Nowacek, 2007; Southall et 
al., 2007; Finneran and Jenkins, 2012). Bottlenose dolphins generally 
travel in large pods and should be visible from a distance in order to 
implement mitigation measures and reduce potential impacts. Many of the 
recorded bottlenose dolphin vocalizations overlap with the MFAS/HFAS 
TTS frequency range (2-20 kHz); however, NMFS does not anticipate TTS 
of a serious degree or extended duration to occur as a result of 
exposure to MFAS/HFAS. Recovery from a threshold shift (TTS) can take a 
few minutes to a few days, depending on the exposure duration, sound 
exposure level, and the magnitude of the initial shift, with larger 
threshold shifts and longer exposure durations requiring longer 
recovery times (Finneran et al., 2005; Mooney et al., 2009a; Mooney et 
al., 2009b; Finneran and Schlundt, 2010). Large threshold shifts are 
not anticipated for these activities because of the unlikelihood that 
animals will remain within the ensonified area at high levels for the 
duration necessary to induce larger threshold shifts. Threshold shifts 
do not necessarily affect all hearing frequencies equally, so some 
threshold shifts may not interfere with an animal's hearing of 
biologically relevant sounds.
    Overall, the number of predicted behavioral reactions is low and 
temporary behavioral reactions in bottlenose dolphins are unlikely to 
cause long-term consequences for individual animals or the population. 
The Civilian Port Defense activities are not expected to occur in an 
area/time of specific importance for reproductive, feeding, or other 
known critical behaviors for bottlenose dolphin. The California/
Washington/Oregon stock of bottlenose dolphin is not depleted under the 
MMPA. In a comparison of abundance estimates from 1987-89 (n = 354), 
1996-98 (n = 356), and 2004-05 (n = 323), Dudzik et al. (2006) found 
that the population size has remained stable over this period of 
approximately 20 years. Consequently, the activities are not expected 
to adversely impact annual rates of recruitment or survival of 
bottlenose dolphin.
    Harbor Seal--Harbor seals that may be found in the Study Area 
belong to the California stock (Carretta et al., 2014). Harbor seals 
have not been observed on the mainland coast of Los Angeles, Orange, 
and northern San Diego Counties (Henkel and Harvey, 2008; Lowry et al., 
2008). Thus, no harbor seal haul-outs are located within the proposed 
Study Area. The Navy's acoustic analysis (quantitative modeling) 
predicts that 8 instances of Level B harassment of harbor seal may 
occur from active sonar in the Study Area during Civilian Port Defense 
training activities. These Level B takes are anticipated to be in the 
form of non-TTS behavioral reactions only and no injurious takes of 
harbor seal are requested or proposed for authorization. Relative to 
population size, these activities are anticipated to result only in a 
limited number of level B harassment takes. When the numbers of 
behavioral takes are compared to the estimated stock abundance (stock 
abundance estimates are shown in Table 1) and if one assumes that each 
take happens to a separate animal, less than 0.03 percent of the 
California stock of harbor seal would be behaviorally harassed during 
proposed training activities.
    Research and observations show that pinnipeds in the water may be 
tolerant of anthropogenic noise and activity (a review of behavioral 
reactions by pinnipeds to impulsive and non-impulsive noise can be 
found in

[[Page 53686]]

Richardson et al., 1995 and Southall et al., 2007). Available data, 
though limited, suggest that exposures between approximately 90 and 140 
dB SPL do not appear to induce strong behavioral responses in pinnipeds 
exposed to nonpulse sounds in water (Jacobs and Terhune, 2002; Costa et 
al., 2003; Kastelein et al., 2006c). Based on the limited data on 
pinnipeds in the water exposed to multiple pulses (small explosives, 
impact pile driving, and seismic sources), exposures in the 
approximately 150 to 180 dB SPL range generally have limited potential 
to induce avoidance behavior in pinnipeds (Harris et al., 2001; 
Blackwell et al., 2004; Miller et al., 2004). If pinnipeds are exposed 
to sonar or other active acoustic sources they may react in a number of 
ways depending on their experience with the sound source and what 
activity they are engaged in at the time of the acoustic exposure. 
Pinnipeds may not react at all until the sound source is approaching 
within a few hundred meters and then may alert, ignore the stimulus, 
change their behaviors, or avoid the immediate area by swimming away or 
diving. Effects on pinnipeds in the Study Area that are taken by Level 
B harassment, on the basis of reports in the literature as well as Navy 
monitoring from past activities, will likely be limited to reactions 
such as increased swimming speeds, increased surfacing time, or 
decreased foraging (if such activity were occurring). Most likely, 
individuals will simply move away from the sound source and be 
temporarily displaced from those areas, or not respond at all. In areas 
of repeated and frequent acoustic disturbance, some animals may 
habituate or learn to tolerate the new baseline or fluctuations in 
noise level. Habituation can occur when an animal's response to a 
stimulus wanes with repeated exposure, usually in the absence of 
unpleasant associated events (Wartzok et al., 2003). While some animals 
may not return to an area, or may begin using an area differently due 
to training activities, most animals are expected to return to their 
usual locations and behavior. Given their documented tolerance of 
anthropogenic sound (Richardson et al., 1995 and Southall et al., 
2007), repeated exposures of harbor seals to levels of sound that may 
cause Level B harassment are unlikely to result in hearing impairment 
or to significantly disrupt foraging behavior.
    Overall, the number of predicted behavioral reactions is low and 
temporary behavioral reactions in harbor seals are unlikely to cause 
long-term consequences for individual animals or the population. The 
Civilian Port Defense activities are not expected to occur in an area/
time of specific importance for reproductive, feeding, or other known 
critical behaviors for harbor seal. In California, harbor seals breed 
from March to May and pupping occurs between April and May (Alden et 
al., 2002; Reeves et al., 2002), neither of which occur within the 
timeframe of the proposed activities. The California stock of harbor 
seal is not depleted under the MMPA. Counts of harbor seals in 
California increased from 1981 to 2004, although a review of harbor 
seal dynamics through 1991 concluded that their status could not be 
determined with certainty (Hanan, 1996). The population appears to be 
stabilizing at what may be its carrying capacity. Consequently, the 
activities are not expected to adversely impact annual rates of 
recruitment or survival of harbor seal.
    California Sea Lion--California sea lions that may be found in the 
Study Area belong to the U.S. stock (Carretta et al., 2014). The Navy's 
acoustic analysis (quantitative modeling) predicts that 46 instances of 
Level B harassment of California sea lion may occur from active sonar 
in the Study Area during Civilian Port Defense training activities. 
These Level B takes are anticipated to be in the form of non-TTS 
behavioral reactions only and no injurious takes of California sea 
lions are requested or proposed for authorization. Relative to 
population size, these activities are anticipated to result only in a 
limited number of level B harassment takes. When the numbers of 
behavioral takes are compared to the estimated stock abundance (stock 
abundance estimates are shown in Table 1) and if one assumes that each 
take happens to a separate animal, less than 0.02 percent of the U.S. 
stock of California sea lions would be behaviorally harassed during 
proposed training activities.
    Research and observations show that pinnipeds in the water may be 
tolerant of anthropogenic noise and activity (a review of behavioral 
reactions by pinnipeds to impulsive and non-impulsive noise can be 
found in Richardson et al., 1995 and Southall et al., 2007). Available 
data, though limited, suggest that exposures between approximately 90 
and 140 dB SPL do not appear to induce strong behavioral responses in 
pinnipeds exposed to nonpulse sounds in water (Jacobs and Terhune, 
2002; Costa et al., 2003; Kastelein et al., 2006c). Based on the 
limited data on pinnipeds in the water exposed to multiple pulses 
(small explosives, impact pile driving, and seismic sources), exposures 
in the approximately 150 to 180 dB SPL range generally have limited 
potential to induce avoidance behavior in pinnipeds (Harris et al., 
2001; Blackwell et al., 2004; Miller et al., 2004). If pinnipeds are 
exposed to sonar or other active acoustic sources they may react in a 
number of ways depending on their experience with the sound source and 
what activity they are engaged in at the time of the acoustic exposure. 
Pinnipeds may not react at all until the sound source is approaching 
within a few hundred meters and then may alert, ignore the stimulus, 
change their behaviors, or avoid the immediate area by swimming away or 
diving. Effects on pinnipeds in the Study Area that are taken by Level 
B harassment, on the basis of reports in the literature as well as Navy 
monitoring from past activities will likely be limited to reactions 
such as increased swimming speeds, increased surfacing time, or 
decreased foraging (if such activity were occurring). Most likely, 
individuals will simply move away from the sound source and be 
temporarily displaced from those areas, or not respond at all. In areas 
of repeated and frequent acoustic disturbance, some animals may 
habituate or learn to tolerate the new baseline or fluctuations in 
noise level. Habituation can occur when an animal's response to a 
stimulus wanes with repeated exposure, usually in the absence of 
unpleasant associated events (Wartzok et al., 2003). While some animals 
may not return to an area, or may begin using an area differently due 
to training activities, most animals are expected to return to their 
usual locations and behavior. Given their documented tolerance of 
anthropogenic sound (Richardson et al., 1995 and Southall et al., 
2007), repeated exposures of individuals to levels of sound that may 
cause Level B harassment are unlikely to result in hearing impairment 
or to significantly disrupt foraging behavior.
    Overall, the number of predicted behavioral reactions is low and 
temporary behavioral reactions in California sea lions are unlikely to 
cause long-term consequences for individual animals or the population. 
The Civilian Port Defense activities are not expected to occur in an 
area/time of specific importance for reproductive, feeding, or other 
known critical behaviors for California sea lions. It is likely that 
male California sea lions will be primarily outside of the Study Area 
during the timeframe of the proposed activities, but females may be 
present. Typically

[[Page 53687]]

during the summer, California sea lions congregate near rookery islands 
and specific open-water areas. The primary rookeries off the coast of 
California are on San Nicolas, San Miguel, Santa Barbara, and San 
Clemente Islands (Boeuf and Bonnell, 1980; Carretta et al., 2000; Lowry 
et al., 1992; Lowry and Forney, 2005). In May or June, female sea lions 
give birth, either on land or in water. Adult males establish breeding 
territories, both on land and in water, from May to July. In addition 
to the rookery sites, Santa Catalina Island is a major haul-out site 
within the Southern California Bight (Boeuf, 2002). Thus, breeding and 
pupping take place outside of the timeframe and location of the 
proposed training activities. The U.S. stock of California sea lions is 
not depleted under the MMPA. A regression of the natural logarithm of 
the pup counts against year indicates that the counts of pups increased 
at an annual rate of 5.4 percent between 1975 and 2008 (when pup counts 
for El Ni[ntilde]o years were removed from the 1975-2005 time series). 
These records of pup counts from 1975 to 2008 were compiled from Lowry 
and Maravilla-Chavez (2005) and unpublished NMFS data. Consequently, 
the activities are not expected to adversely impact annual rates of 
recruitment or survival of California sea lion.

Preliminary Determination

    Overall, the conclusions and predicted exposures in this analysis 
find that overall impacts on marine mammal species and stocks would be 
negligible for the following reasons:
     All estimated acoustic harassments for the proposed 
Civilian Port Defense training activities are within the non-injurious 
temporary threshold shift (TTS) or behavioral effects zones (Level B 
harassment), and these harassments (take numbers) represent only a 
small percentage (less than 15 percent of bottlenose dolphin coastal 
stock; less than 0.5 percent for all other species) of the respective 
stock abundance for each species taken.
     Marine mammal densities inputted into the model are also 
overly conservative, particularly when considering species where data 
is limited in portions of the proposed study area and seasonal 
migrations extend throughout the Study Area.
     The protective measures described in Proposed Mitigation 
are designed to reduce sound exposure on marine mammals to levels below 
those that may cause physiological effects (injury).
     Animals exposed to acoustics from this two week event are 
habituated to a bustling industrial port environment.
    This proposed IHA assumes that short-term non-injurious SELs 
predicted to cause onset-TTS or predicted SPLs predicted to cause 
temporary behavioral disruptions (non-TTS) qualify as Level B 
harassment. This approach predominately overestimates disturbances from 
acoustic transmissions as qualifying as harassment under MMPA's 
definition for military readiness activities because there is no 
established scientific correlation between short term sonar use and 
long term abandonment or significant alteration of behavioral patterns 
in marine mammals.
    Consideration of negligible impact is required for NMFS to 
authorize incidental take of marine mammals. By definition, an activity 
has a ``negligible impact'' on a species or stock when it is determined 
that the total taking is not likely to reduce annual rates of adult 
survival or recruitment (i.e., offspring survival, birth rates).
    Behavioral reactions of marine mammals to sound are known to occur 
but are difficult to predict. Recent behavioral studies indicate that 
reactions to sounds, if any, are highly contextual and vary between 
species and individuals within a species (Moretti et al., 2010; 
Southall et al., 2011; Thompson et al., 2010; Tyack, 2009; Tyack et 
al., 2011). Depending on the context, marine mammals often change their 
activity when exposed to disruptive levels of sound. When sound becomes 
potentially disruptive, cetaceans at rest become active, feeding or 
socializing cetaceans or pinnipeds often interrupt these events by 
diving or swimming away. If the sound disturbance occurs around a haul 
out site, pinnipeds may move back and forth between water and land or 
eventually abandon the haul out. When attempting to understand 
behavioral disruption by anthropogenic sound, a key question to ask is 
whether the exposures have biologically significant consequences for 
the individual or population (National Research Council of the National 
Academies, 2005).
    If a marine mammal does react to an underwater sound by changing 
its behavior or moving a small distance, the impacts of the change may 
not be detrimental to the individual. For example, researchers have 
found during a study focusing on dolphins response to whale watching 
vessels in New Zealand, that when animals can cope with constraint and 
easily feed or move elsewhere, there's little effect on survival 
(Lusseau and Bejder, 2007). On the other hand, if a sound source 
displaces marine mammals from an important feeding or breeding area for 
a prolonged period and they do not have an alternate equally desirable 
area, impacts on the marine mammal could be negative because the 
disruption has biological consequences. Biological parameters or key 
elements having greatest importance to a marine mammal relate to its 
ability to mature, reproduce, and survive. For example, some elements 
that should be considered include the following:
     Growth: Adverse effects on ability to feed;
     Reproduction: The range at which reproductive displays can 
be heard and the quality of mating/calving grounds; and
     Survival: Sound exposure may directly affect survival, for 
example where sources of a certain type are deployed in a a manner that 
could lead to a stranding response.
    The importance of the disruption and degree of consequence for 
individual marine mammals often has much to do with the frequency, 
intensity, and duration of the disturbance. Isolated acoustic 
disturbances such as acoustic transmissions usually have minimal 
consequences or no lasting effects for marine mammals. Marine mammals 
regularly cope with occasional disruption of their activities by 
predators, adverse weather, and other natural phenomena. It is also 
reasonable to assume that they can tolerate occasional or brief 
disturbances by anthropogenic sound without significant consequences.
    The exposure estimates calculated by predictive models currently 
available reliably predict propagation of sound and received levels and 
measure a short-term, immediate response of an individual using 
applicable criteria. Consequences to populations are much more 
difficult to predict and empirical measurement of population effects 
from anthropogenic stressors is limited (National Research Council of 
the National Academies, 2005). To predict indirect, long-term, and 
cumulative effects, the processes must be well understood and the 
underlying data available for models. Based on each species' life 
history information, expected behavioral patterns in the Study Area, 
all of the modeled exposures resulting in temporary behavioral 
disturbance (Table 5), and the application of mitigation procedures 
proposed above, the proposed Civilian Port Defense activities are 
anticipated to have a negligible impact on marine mammal stocks within 
the Study Area.
    NMFS concludes that Civilian Port Defense training activities 
within the Study Area would result in Level B takes only, as summarized 
in Table 5.

[[Page 53688]]

The effects of these military readiness activities will be limited to 
short-term, localized changes in behavior and possible temporary 
threshold shift in the hearing of marine mammal species. These effects 
are not likely to have a significant or long-term impact on feeding, 
breeding, or other important biological functions. No take by injury or 
mortality is anticipated, and the potential for permanent hearing 
impairment is unlikely. Based on best available science NMFS concludes 
that exposures to marine mammal species and stocks due to the proposed 
training activities would result in only short-term effects from those 
Level B takes to most individuals exposed and would likely not affect 
annual rates of recruitment or survival.
    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 Civilian Port Defense 
training activities in the Study Area will have a negligible impact on 
the affected species or stocks.

Subsistence Harvest of Marine Mammals

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

NEPA

    The Navy is preparing an EA in accordance with the National 
Environmental Policy Act (NEPA), to evaluate all components of the 
proposed Civilian Port Defense training activities. NMFS intends to 
adopt the Navy's EA, if adequate and appropriate. Currently, we believe 
that the adoption of the Navy's EA will allow NMFS to meet its 
responsibilities under NEPA for the issuance of an IHA to the Navy for 
Civilian Port Defense activities at the Ports of Los Angeles and Long 
Beach Harbor. If necessary, however, NMFS will supplement the existing 
analysis to ensure that we comply with NEPA prior to the issuance of 
the final IHA.

 ESA

    No species listed under the Endangered Species Act (ESA) are 
expected to be affected by the proposed Civilian Port Defense training 
activities and no takes of any ESA-listed species are requested or 
proposed for authorization under the MMPA. Therefore, NMFS has 
determined that a formal section 7 consultation under the ESA is not 
required.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to the Navy for conducting Civilian Port Defense 
activities from October to November 2015 on the U.S. west coast near 
Los Angeles/Long Beach, California, provided the previously mentioned 
mitigation, monitoring, and reporting requirements are incorporated. 
The proposed IHA language is provided next.
    This section contains a draft of the IHA itself. The wording 
contained in this section is proposed for inclusion in the IHA (if 
issued).
    The Commander, U.S. Pacific Fleet, 250 Makalapa Drive, Pearl 
Harbor, Hawaii 96860, and persons operating under his authority (i.e., 
Navy), is hereby authorized under section 101(a)(5)(D) of the Marine 
Mammal Protection Act (16 U.S.C. 1371(a)(5)(D)) and 50 CFR 216.107, to 
harass marine mammals incidental to Civilian Port Defense training 
activities proposed to be conducted near the Ports of Los Angeles and 
Long Beach from October to November 2015.
    1. This Authorization is valid from October 25, 2015 through 
November 25, 2015.
    2. This Authorization is valid for the incidental taking of a 
specified number of marine mammals, incidental to Civilian Port Defense 
training activities proposed to be conducted near the Ports of Los 
Angeles and Long Beach from October to November 2015, as described in 
the Incidental Harassment Authorization (IHA) application.
    3. The holder of this authorization (Holder) is hereby authorized 
to take, by Level B harassment only, 8 long-beaked common dolphins 
(Delphinus capensis), 727 short-beaked common dolphins (Delphinus 
delphis), 21 Risso's dolphins (Grampus griseus), 40 Pacific white-sided 
dolphins (Lagenorhynchus obilquidens), 48 bottlenose dolphins (Tursiops 
truncates), 8 harbor seals (Phoca vitulina), and 46 California sea 
lions (Zalophus californianus) incidental to Civilian Port Defense 
training activities proposed to be conducted near the Ports of Los 
Angeles and Long Beach, California.
    4. The taking of any marine mammal in a manner prohibited under 
this IHA must be reported immediately to NMFS' Office of Protected 
Resources, 1315 East-West Highway, Silver Spring, MD 20910; phone 301-
427-8401; fax 301-713-0376.
    5. Mitigation Requirements
    The Holder is required to abide by the following mitigation 
conditions listed in 5(a)-(b). Failure to comply with these conditions 
may result in the modification, suspension, or revocation of this IHA.
(a) Lookouts
    The following are protective measures concerning the use of 
Lookouts:
    Procedural Measures--The Navy will have two types of lookouts for 
the purposes of conducting visual observations: (1) Those positioned on 
surface ships, and (2) those positioned in aircraft or on boats. 
Lookouts positioned on surface ships will be dedicated solely to 
diligent observation of the air and surface of the water. Their 
observation objectives will include, but are not limited to, detecting 
the presence of biological resources and recreational or fishing boats, 
observing mitigation zones, and monitoring for vessel and personnel 
safety concerns. Lookouts positioned in aircraft or on boats will, to 
the maximum extent practicable and consistent with aircraft and boat 
safety and training requirements, comply with the observation 
objectives described above for Lookouts positioned on surface ships.
    Active Sonar--The Navy will have one Lookout on ships or aircraft 
conducting high-frequency active sonar activities associated with mine 
warfare activities at sea.
    Vessels--While underway, vessels will have a minimum of one 
Lookout.
    Towed In-Water Devices--The Navy will have one Lookout during 
activities using towed in-water devices when towed from a manned 
platform.
    (b) Mitigation Zones--The following are protective measures 
concerning the implementation of mitigation zones:
    Active Sonar--Mitigation will include visual observation from a 
vessel or aircraft (with the exception of platforms operating at high 
altitudes) immediately before and during active transmission within a 
mitigation zone of 200 yards (yds. [183 m]) from the active sonar 
source. If the source can be turned off during the activity, active 
transmission will cease if a marine mammal is sighted within the 
mitigation zone. Active transmission will recommence if any one of the 
following conditions is met: (1) the animal is observed exiting the 
mitigation zone, (2) the animal is thought to have exited the 
mitigation zone based on a determination of its course and speed and 
the relative motion between the animal and the source, (3) the 
mitigation zone has been clear from any additional sightings for a

[[Page 53689]]

period of 10 minutes for an aircraft-deployed source, (4) the 
mitigation zone has been clear from any additional sightings for a 
period of 30 minutes for a vessel-deployed source, (5) the vessel or 
aircraft has repositioned itself more than 400 yds (366 m) away from 
the location of the last sighting, or (6) the vessel concludes that 
dolphins are deliberately closing in to ride the vessel's bow wave (and 
there are no other marine mammal sightings within the mitigation zone).
    Vessels--Vessels will avoid approaching marine mammals head on and 
will maneuver to maintain a mitigation zone of 500 yds (457 m) around 
observed whales, and 200 yds (183 m) around all other marine mammals 
(except bow riding dolphins), providing it is safe to do so.
    Towed In-Water Devices--The Navy will ensure that towed in-water 
devices being towed from manned platforms avoid coming within a 
mitigation zone of 250 yds (229 m) around any observed marine mammal, 
providing it is safe to do so.
    6. Monitoring and Reporting Requirements
    The Holder is required to abide by the following monitoring and 
reporting conditions. Failure to comply with these conditions may 
result in the modification, suspension, or revocation of this IHA.
    General Notification of Injured or Dead Marine Mammals--If any 
injury or death of a marine mammal is observed during the Civilian Port 
Defense training activity, the Navy will immediately halt the activity 
and report the incident to NMFS following the standard monitoring and 
reporting measures consistent with the MITT EIS/OEIS. The reporting 
measures include the following procedures:
    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 activity 
utilizing high-frequency active sonar. 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). The Navy shall consult the Stranding Response and 
Communication Plan to obtain more specific reporting requirements for 
specific circumstances.
    Vessel Strike--Vessel strike during Navy Civilian Port Defense 
activities in the Study Area is not anticipated; however, in the event 
that a Navy vessel strikes a whale, the Navy shall do the following:
    Immediately report to NMFS (pursuant to the established 
Communication Protocol) the:
     Species identification (if known);
     Location (latitude/longitude) of the animal (or location 
of the strike if the animal has disappeared);
     Whether the animal is alive or dead (or unknown); and
     The time of the strike.
    As soon as feasible, the Navy shall report to or provide to NMFS, 
the:
     Size, length, and description (critical if species is not 
known) of animal;
     An estimate of the injury status (e.g., dead, injured but 
alive, injured and moving, blood or tissue observed in the water, 
status unknown, disappeared, etc.);
     Description of the behavior of the whale during event, 
immediately after the strike, and following the strike (until the 
report is made or the animal is no longer sighted);
     Vessel class/type and operational status;
     Vessel length;
     Vessel speed and heading; and
     To the best extent possible, obtain a photo or video of 
the struck animal, if the animal is still in view.
    Within 2 weeks of the strike, provide NMFS:
     A detailed description of the specific actions of the 
vessel in the 30-minute timeframe immediately preceding the strike, 
during the event, and immediately after the strike (e.g., the speed and 
changes in speed, the direction and changes in direction, other 
maneuvers, sonar use, etc., if not classified);
     A narrative description of marine mammal sightings during 
the event and immediately after, and any information as to sightings 
prior to the strike, if available; and use established Navy shipboard 
procedures to make a camera available to attempt to capture photographs 
following a ship strike.
    NMFS and the Navy will coordinate to determine the services the 
Navy may provide to assist NMFS with the investigation of the strike. 
The response and support activities to be provided by the Navy are 
dependent on resource availability, must be consistent with military 
security, and must be logistically feasible without compromising Navy 
personnel safety. Assistance requested and provided may vary based on 
distance of strike from shore, the nature of the vessel that hit the 
whale, available nearby Navy resources, operational and installation 
commitments, or other factors.
    7. A copy of this Authorization must be in the possession of the 
on-site Commanding Officer in order to take marine mammals under the 
authority of this Incidental Harassment Authorization while conducting 
the specified activities.
    8. This Authorization may be modified, suspended, or withdrawn if 
the Holder or any person operating under his authority fails to abide 
by the conditions prescribed herein or if the authorized taking is 
having more than a negligible impact on the species or stock of 
affected marine mammals.

Request for Public Comments

    NMFS requests comment on our analysis, the draft authorization, and 
any other aspect of the Notice of Proposed IHA for the Navy's Civilian 
Port Defense training activities. Please include with your comments any 
supporting data or literature citations to help inform our final 
decision on the Navy's request for an MMPA authorization.

    Dated: August 31, 2015.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2015-21911 Filed 9-3-15; 8:45 am]
 BILLING CODE 3510-22-P