Takes of Marine Mammals Incidental to Specified Activities; Navy Training Conducted at the Silver Strand Training Complex, San Diego Bay, 24161-24184 [2013-09618]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 78, Number 79 (Wednesday, April 24, 2013)]
[Notices]
[Pages 24161-24184]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-09618]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XC533


Takes of Marine Mammals Incidental to Specified Activities; Navy 
Training Conducted at the Silver Strand Training Complex, San Diego Bay

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 complete application from the U.S. Navy 
(Navy) for an Incidental Harassment Authorization (IHA) to take marine 
mammals, by harassment, incidental to conducting training exercises at 
the Silver Strand Training Complex (SSTC) in the vicinity of San Diego 
Bay, California. Pursuant to the Marine Mammal Protection Act (MMPA), 
NMFS is requesting comments on its proposal to issue an IHA to the Navy 
to incidentally harass, by Level B Harassment only, eight species of 
marine mammals during the specified activity.

DATES: Comments and information must be received no later than May 24, 
2013.

ADDRESSES: Comments on the application should be addressed to P. 
Michael Payne, Chief, Permits and Conservation Division, Office of 
Protected Resources, National Marine Fisheries Service, 1315 East-West 
Highway, Silver Spring, MD 20910-3225. The mailbox address for 
providing email comments is itp.magliocca@noaa.gov. NMFS is not 
responsible for email comments sent to addresses other than the one 
provided here. Comments sent via email, including all attachments, must 
not exceed a 10-megabyte file size.
    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.htm 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.
    A copy of the application may be obtained by visiting the internet 
at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm. Documents cited 
in this notice may also be viewed, by appointment, during regular 
business hours, at the aforementioned address.

FOR FURTHER INFORMATION CONTACT: Michelle Magliocca, Office of 
Protected Resources, NMFS, (301) 427-8401.

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 (Secretary) 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) if certain findings are made and regulations are 
issued or, if the taking is limited to harassment, notice of a proposed 
authorization is provided to the public for review.
    Authorization 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

[[Page 24162]]

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 taking are set forth. NMFS has defined 
``negligible impact'' in 50 CFR 216.103 as: ``* * * an impact resulting 
from the specified activity that cannot be reasonably expected to, and 
is not reasonably likely to, adversely affect the species or stock 
through effects on annual rates of recruitment or survival.''
    The National Defense Authorization Act of 2004 (NDAA) (Public Law 
108-136) removed the ``small numbers'' and ``specified geographical 
region'' limitations and amended the definition of ``harassment'' as it 
applies to a ``military readiness activity'' to read as follows 
(Section 3(18)(B) of the MMPA): (i) Any act that injures or has the 
significant potential to injure a marine mammal or marine mammal stock 
in the wild [Level A Harassment]; or (ii) any act that disturbs or is 
likely to disturb a marine mammal or marine mammal stock in the wild by 
causing disruption of natural behavioral patterns, including, but not 
limited to, migration, surfacing, nursing, breeding, feeding, or 
sheltering, to a point where such behavioral patterns are abandoned or 
significantly altered [Level B Harassment].
    Section 101(a)(5)(D) of the MMPA established an expedited process 
by which citizens of the United States can apply for an authorization 
to incidentally take small numbers of marine mammals by harassment. 
Section 101(a)(5)(D) establishes a 45-day time limit for NMFS review of 
an application followed by a 30-day public notice and comment period on 
any proposed authorizations for the incidental harassment of marine 
mammals. Within 45 days of the close of the comment period, NMFS must 
either issue or deny the authorization.

Summary of Request

    NMFS received an application on December 19, 2012, from the Navy 
for the taking, by harassment, of marine mammals incidental to 
conducting training exercises at the Navy's Silver Strand Training 
Complex (SSTC) in the vicinity of San Diego Bay, California. Underwater 
detonations and pile driving/removal during training events at the SSTC 
may rise to the level of harassment as defined under the MMPA. The Navy 
is currently operating under an IHA for training activities at the SSTC 
covering the period from July 18, 2012, through July 17, 2013.

Description of the Specific Activity

    The Navy has conducted a review of its continuing and proposed 
training conducted at the SSTC to determine whether there is a 
potential for harassment of marine mammals. Underwater detonation 
training and pile driving, as described below, may result in the 
incidental take of marine mammals from elevated levels of sound. Other 
training events conducted at the SSTC, which are not expected to rise 
to the level of harassment, are described in the SSTC Final 
Environmental Impact Statement (https://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications).

Underwater Detonations

    Underwater detonations are conducted by Explosive Ordnance Disposal 
(EOD) units, Naval Special Warfare (NSW) units, MH-60S Mine 
Countermeasure helicopter squadrons, and Mobile Diving and Salvage 
units at the SSTC. The training provides Navy personnel with hands-on 
experience with the design, deployment, and detonation of underwater 
clearance devices of the general type and size that they are required 
to understand and utilize in combat. EOD units conduct most of the 
underwater detonation training at the SSTC as part of their training in 
the detection, avoidance, and neutralization of mines. Tables 1-3 and 
2-1 in the Navy's LOA application describe in detail the types of 
underwater detonation training events conducted at the SSTC. Below is a 
basic description of some underwater detonation procedures that 
typically apply to underwater training events at the SSTC, with the 
exception of the Unmanned Underwater Vehicle Neutralization and 
Airborne Mine Neutralization System.
     Prior to getting underway, all EOD and NSW personnel 
conduct a detailed safety and procedure briefing to familiarize 
everyone with the goals, objectives, and safety requirements (including 
mitigation zones) applicable to the particular training event.
     For safety reasons, and in accordance with Navy 
directives, given the training nature of many of these events, 
underwater detonations only occur during daylight and are only 
conducted in sea-states of up to Beaufort 3 (presence of large 
wavelets, crests beginning to break, presence of glassy foam, and/or 
perhaps scattered whitecaps).
     EOD or NSW personnel can be transported to the planned 
detonation site via small boat or helicopter depending on the training 
event. Small boats can include 7-m Rigid Hull Inflatable Boats (RHIB), 
zodiacs, or other similar craft as available to the particular unit.
     Once on site, the applicable mitigation zone is 
established and visual survey commences for 30 minutes. Divers enter 
the water to conduct the training objective which could include 
searching for a training object such as a simulated mine or mine-like 
shape.
     For the detonation part of the training, the explosive 
charge and associate charge initiating device are taken to the 
detonation point. The explosives used are military forms of C-4. In 
order to detonate C-4, a fusing and initiating device is required.
     Following a particular underwater detonation, additional 
personnel in the support boats (or helicopter) keep watch within the 
mitigation zone for 30 minutes.
     Concurrent with the post-detonation survey, divers return 
to the detonation site to confirm the explosives detonated correctly 
and retrieve any residual material (pieces of wire, tape, large 
fragments, etc.).
    The Navy uses both time-delay and positive control to initiate 
underwater detonations, depending on the training event and objectives. 
The time-delay method uses a Time-delay Firing Device (TDFD) and the 
positive control method most commonly uses a Remote Firing Device 
(RFD). TDFDs are the simplest, safest, least expensive, most 
operationally acceptable method of initiating an underwater detonation. 
TDFDs are preferred due to their light weight, low magnetic signature 
(in cases of mines sensitive to magnetic fields), and reduced risk of 
accidental detonation from nearby radios or other electronics. TDFDs 
allow sufficient time for EOD personnel to swim outside of the 
detonation plume radius and human safety buffer zone after the timer is 
set. For a surface detonation training event involving a helicopter or 
a boat, the minimum time-delay that is reasonable for EOD divers to 
make their way to safety is about 10 minutes. For underwater detonation 
training events at depth using small boats, the time-delay can be 
minimized to 5 minutes; however, this requires the instructors to 
handle initiation of the detonation and therefore results in decreased 
training value for students. The Navy considers it critical that EOD 
and NSW platoons qualify annually with necessary time-delay 
certification, maintain proficiency, and train to face real-world 
scenarios that require use of TDFDs.
    While positive control devices do allow for instantaneous 
detonation of a

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charge and are used for some SSTC training events, RFDs are the less-
preferred method to initiate an underwater detonation. Current Navy 
RFDs use a radio signal to remotely detonate a charge. By using 
electronic positive control devices such as the RFD, additional 
electronic signals and metal from the receiver and wiring is 
unnecessarily introduced into the operating environment. Underwater 
detonation events need to be kept as simple and streamlined as 
possible, especially when diver safety is considered. In an open ocean 
environment, universal use of RFDs would greatly increase the risk of 
misfire due to component failure, and put unnecessary stress on all 
needed connections and devices (adding 600-1,000 feet of firing wire; 
building/deploying an improvised, bulky, floating system for the RFD 
receiver; and adding another 180 feet of detonating cord plus 10 feet 
of other material).

Pile Driving

    Installation and removal of Elevated Causeway System (ELCAS) 
support piles may also result in the harassment of marine mammals. The 
ELCAS is a modular pre-fabricated causeway pier that links offshore 
amphibious supply ships with associated lighterage (i.e., small cargo 
boats and barges). Offloaded vehicles and supplies can be driven on the 
causeway to and from shore.
    During ELCAS training events, 24-inch wide hollow steel piles would 
be driven into the sand in the surf zone with an impact hammer. About 
101 piles would be driven into the beach and surf zone with a diesel 
impact hammer over the course of about 10 days, 24-hours per day (i.e., 
day and night). Each pile takes an average of 10 minutes to install, 
with around 250 to 300 impacts per pile. Pile driving includes a semi-
soft start as part of the normal operating procedure based on the 
design of the drive equipment. The pile driver increases impact 
strength as resistance goes up. At first, the pile driver piston drops 
a few inches. As resistance goes up, the pile driver piston drops from 
a higher distance, providing more impact due to gravity. The pile 
driver can take 5 to 7 minutes to reach full impact strength. As 
chapters of piles are installed, causeway platforms are then hoisted 
and secured onto the piles with hydraulic jacks and cranes. At the end 
of training, the ELCAS piles would be removed with a vibratory 
extractor. Removal takes about 15 minutes per pile over a period of 
around 3 days. ELCAS training may occur along both the ocean side 
(SSTC-North boat and beach lanes) and with the designated training lane 
within Bravo beach on the bayside of SSTC. Up to four ELCAS training/
installation events may occur during the year.

Dates and Duration of Proposed Activities

    The Navy's proposed activities would occur between July 2013 and 
July 2014. Most underwater detonation training events include one or 
two detonations. Table 2-1 in the Navy's LOA application shows the 19 
different types and number of training events per year in the SSTC. 
Pile installation and removal would occur over an approximate 13 day 
period, up to four times per year. NMFS is proposing to issue a 1-year 
IHA that may be superseded if we issue a Letter of Authorization under 
regulations for the Navy's Hawaii-Southern California Training and 
Testing (HSTT) (which would include the SSTC) prior to expiration of 
the IHA.

Location of Proposed Activities

    The SSTC (Figure 1-1 of the Navy's IHA application) is located in 
and adjacent to San Diego Bay, south of Coronado, California and north 
of Imperial Beach, California. The complex is composed of ocean and bay 
training lanes, adjacent beach training areas, ocean anchorages, and 
inland training areas. To facilitate range management and scheduling, 
the SSTC is divided into numerous training sub-areas.
    The surfside training lanes of the SSTC are located in the Silver 
Strand Littoral Cell, which is an exposed, open subtidal area of the 
Pacific Ocean extending from south of the international border to the 
Zuniga Jetty at San Diego Bay for over 17 miles of coastal reach. The 
Silver Strand Littoral Cell is a coastal eddy system that dominates 
local ocean movement and generally moves from south to north with 
periodic reversals. Surface water temperatures generally are highest 
from June through September and lowest from November through February. 
Historical temperatures in the study area range from 52 to 74 degrees 
Fahrenheit near the surface and from 49 to 61 degrees Fahrenheit near 
the bottom. Water temperatures near the beach tend to be more uniform 
throughout the water column due to turbulent mixing and shallower 
depth. The bathymetry off the surfside training lanes is relatively 
evenly sloped, with a predominantly soft sandy bottom mixed with minor 
amounts of mud, hard-shale bedrock, and small cobble-boulder fields. 
The area does not have underwater canyons or significant upwelling 
conditions. Flora and fauna in the region of the SSTC is dominated by 
coastal surf zone and some coastal pelagic zone species. In the summer 
of 2011, the Navy funded a new benthic habitat survey to reassess 
benthic habitat and bottom conditions with results shown in Figure 2-1 
of the Navy LOA application. A second follow-up benthic habitat survey 
was performed in the late summer and fall of 2012 to cover areas 
between SSTC-North and SSTC-South, as well as areas further offshore to 
the 120-foot contour.

Description of Marine Mammals in the Area of the Specified Activity

    Four marine mammal species may inhabit or regularly transit the 
SSTC area: California sea lion (Zalophus californianus), Pacific harbor 
seal (Phoca vitulina richardsii), California coastal stock of 
bottlenose dolphin (Tursiops truncatus), and gray whale (Eschrichtius 
robustus). Following the incident of common dolphin mortalities that 
resulted from the use of TDFDs during a training exercise in 2012, the 
Navy and NMFS reassessed the species distribution in the SSTC study 
area and included four additional dolphin species: long-beaked common 
dolphin (Delphinus capensis), short-beaked common dolphin (D. delphis), 
Pacific white-sided dolphin (Lagenorhynchus obliquidens), and Risso's 
dolphin (Grampus griseus). These four dolphin species are less frequent 
visitors, but have been sighted in the vicinity of the SSTC training 
area.
    Navy-funded surveys in the SSTC in late 2012 and 2013 have 
documented the sporadic presence of long-beaked common dolphins near 
some parts of the SSTC. There is no documented NMFS sighting data for 
short-beaked common dolphin, Pacific white-sided dolphin, or Risso's 
dolphin, or other anecdotal information currently available as to 
likely presence within the very near-shore, shallow waters associated 
with the SSTC boat lanes. Therefore, the Navy included these species in 
their analysis in the rare event that they move through the SSTC boat 
lanes. None of the species above are listed as threatened or endangered 
under the Endangered Species Act (ESA). Further information on these 
species can also be found in the NMFS Stock Assessment Reports (SAR) 
(https://www.nmfs.noaa.gov/pr/species/mammals/).

California Sea Lions

    The California sea lion is by far the most commonly-sighted 
pinniped species at sea or on land in the vicinity of the SSTC. Nearly 
all of the U.S. Stock

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(more than 95 percent) of California sea lion breeds and gives birth to 
pups on San Miguel, San Nicolas, and Santa Barbara islands off 
California. Smaller numbers of pups are born on the Farallon Islands, 
and A[ntilde]o Nuevo Island (Lowry et al. 1992). In California waters, 
sea lions represented 97 percent (381 of 393) of identified pinniped 
sightings at sea during the 1998-1999 NMFS surveys (Carretta et al. 
2000). They were sighted during all seasons and in all areas with 
survey coverage from nearshore to offshore areas (Carretta et al. 
2000).
    Survey data from 1975 to 1978 were analyzed to describe the 
seasonal shifts in the offshore distribution of California sea lions 
(Bonnell and Ford 1987). During summer, the highest densities were 
found immediately west of San Miguel Island. During autumn, peak 
densities of sea lions were centered on Santa Cruz Island. During 
winter and spring, peak densities occurred just north of San Clemente 
Island. The seasonal changes in the center of distribution were 
attributed to changes in the distribution of the prey species. If 
California sea lion distribution is determined primarily by prey 
abundance as influenced by variations in local, seasonal, and inter-
annual oceanographic variation, these same areas might not be the 
center of sea lion distribution every year. Costa et al. (2007) was 
able to identify kernel home range contours for foraging female sea 
lions during non-El Nino conditions, although there was some variation 
over the three years of this tagging study. Melin et al. (2008) showed 
that foraging female sea lions showed significant variability in 
individual foraging behavior, and foraged farther offshore and at 
deeper depths during El Nino years as compared to non-El Nino years. 
The distribution and habitat use of California sea lions vary with the 
sex of the animals and their reproductive phase. Adult males haul out 
on land to defend territories and breed from mid-to-late May until late 
July. The pupping and mating season for sea lions begins in late May 
and continues through July (Heath 2002). Individual males remain on 
territories for 27-45 days without going to sea to feed. During August 
and September, after the mating season, the adult males migrate 
northward to feeding areas as far away as Washington (Puget Sound) and 
British Columbia (Lowry et al. 1992). They remain there until spring 
(March-May), when they migrate back to the breeding colonies. Thus, 
adult males are present in offshore areas of the SSTC only briefly as 
they move to and from rookeries. Distribution of immature California 
sea lions is less well known, but some make northward migrations that 
are shorter in length than the migrations of adult males (Huber 1991). 
However, most immature sea lions are presumed to remain near the 
rookeries, and thus remain near SSTC for most of the year (Lowry et al. 
1992). Adult females remain near the rookeries throughout the year. 
Most births occur from mid-June to mid-July (peak in late June).
    California sea lions feed on a wide variety of prey, including 
Pacific whiting, northern anchovy, mackerel, squid, sardines, and 
rockfish (Antonelis et al. 1990; Lowry et al. 1991; Lowry and Carretta 
1999; Lowry and Forney 2005; Bearzi 2006). In Santa Monica Bay, 
California sea lions are known to follow and feed near bottlenose 
dolphins (Bearzi 2006), and if in the near shore waters of SSTC, may 
forage on common coastal beach fish species (corbina and barred 
surfperch) (Allen 2006).
    There are limited published at-sea density estimates for pinnipeds 
within Southern California. Higher densities of California sea lions 
are observed during cold-water months. At-sea densities likely decrease 
during warm-water months because females spend more time ashore to give 
birth and attend to their pups. Radio-tagged female California sea 
lions at San Miguel Island spent approximately 70 percent of their time 
at sea during the non-breeding season (cold-water months) and pups 
spent an average of 67 percent of their time ashore during their 
mother's absence (Melin and DeLong 2000). Different age classes of 
California sea lions are found in the offshore areas of SSTC throughout 
the year (Lowry et al. 1992). Although adult male California sea lions 
feed in areas north of SSTC, animals of all other ages and sexes spend 
most, but not all, of their time feeding at sea during winter, thus, 
the winter estimates likely are somewhat low. During warm-water months, 
a high proportion of the adult males and females are hauled out at 
terrestrial sites during much of the period, so the summer estimates 
are low to a greater degree.
    The NMFS population estimate of the U.S. Stock of California sea 
lions is 296,750 (Carretta et al. 2010). The California sea lion is not 
listed under the ESA, and the U.S. Stock, some of which occurs in the 
SSTC, is not considered a strategic stock under the MMPA.

Pacific Harbor Seal

    Harbor seals are considered abundant throughout most of their range 
from Baja California to the eastern Aleutian Islands. An unknown number 
of harbor seals also occur along the west coast of Baja California, at 
least as far south as Isla Asuncion, which is about 100 miles south of 
Punta Eugenia. Animals along Baja California are not considered to be a 
part of the California stock because it is not known if there is any 
demographically significant movement of harbor seals between California 
and Mexico (Carretta et al. 2010). Peak numbers of harbor seals haul 
out on land during late May to early June, which coincides with the 
peak of their molt. They generally favor sandy, cobble, and gravel 
beaches (Stewart and Yochem 1994; 2000), and most haul out on the 
central California mainland and Santa Cruz Island (Lowry and Carretta 
2003; Carretta et al. 2010).
    There are limited at-sea density estimates for pinnipeds within 
Southern California. Harbor seals do not make extensive pelagic 
migrations, but do travel 300-500 km on occasion to find food or 
suitable breeding areas (Herder 1986; Carretta et al. 2007). Nursing of 
pups begins in late February, and pups start to become weaned in May. 
Breeding occurs between late March and early May on the southern and 
northern Channel Islands. When at sea during May and June (and March to 
May for breeding females), they generally remain in the vicinity of 
haul out sites and forage close to shore in relatively shallow waters. 
Based on likely foraging strategies, Grigg et al. (2009) reported 
seasonal shifts in harbor seal movements based on prey availability.
    Harbor seals are opportunistic feeders that adjust their feeding to 
take advantage of locally and seasonally abundant prey which can 
include small crustaceans, rock fish, cusk-eel, octopus, market squid, 
and surfperch (Bigg 1981; Payne and Selzer 1989; Stewart and Yochem 
1994; Stewart and Yochem 2000; Baird 2001; Oates 2005). If in the near 
shore waters of SSTC, harbor seals may forage on common coastal beach 
fish species, such as corbina and barred surfperch (Allen 2006).
    Harbor seals are found in the SSTC throughout the year (Carretta et 
al. 2000). Based on the most recent harbor seal counts (19,608 in May-
July 2009; NMFS unpublished data) and the Harvey and Goley (2011) 
correction factor, the harbor seal population in California is 
estimated to number 30,196.
    The harbor seal is not listed under the ESA, and the California 
Stock, some of which occurs in the SSTC, is not considered a strategic 
stock under the MMPA. The California population has increased from the 
mid-1960s to the

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mid-1990s, although the rate of increase may have slowed during the 
1990s as the population has reached and may be stabilizing at carrying 
capacity (Hanan 1996, Carretta et al. 2010).

Bottlenose Dolphin

    There are two distinct populations of bottlenose dolphins within 
southern California, a coastal population found within 0.5 nm (0.9 km) 
of shore and a larger offshore population (Hansen 1990; Bearzi et al. 
2009). The California Coastal Stock is the only one of these two stocks 
likely to occur within the SSTC. The bottlenose dolphin California 
Coastal Stock occurs at least from Point Conception south into Mexican 
waters, at least as far south as San Quintin, Mexico. Bottlenose 
dolphins in the Southern California Bight (SCB) appear to be highly 
mobile within a relatively narrow coastal zone (Defran et al. 1999), 
and exhibit no seasonal site fidelity to the region (Defran and Weller 
1999). There is little site fidelity of coastal bottlenose dolphins 
along the California coast; over 80 percent of the dolphins identified 
in Santa Barbara, Monterey, and Ensenada have also been identified off 
San Diego (Defran et al. 1999; Maldini-Feinholz 1996; Carretta et al. 
2008; Bearzi et al. 2009). Bottlenose dolphins could occur in the SSTC 
at variable frequencies and periods throughout the year based on 
localized prey availability (Defran et al. 1999).
    The Pacific coast bottlenose dolphins feed primarily on surf 
perches and croakers (Norris and Prescott 1961; Walker 1981; Schwartz 
et al. 1992; Hanson and Defran 1993), and also consume squid (Schwartz 
et al. 1992). The coastal stock of bottlenose dolphin utilizes a 
limited number of fish prey species with up to 74 percent being various 
species of surfperch or croakers, a group of non-migratory year-round 
coastal inhabitants (Defran et al. 1999; Allen et al. 2006). For 
Southern California, common croaker prey species include spotfin 
croaker, yellowfin croaker, and California corbina, while common 
surfperch species include barred surfperch and walleye surfperch (Allen 
et al. 2006). The corbina and barred surfperch are the most common surf 
zone fish where bottlenose dolphins have been observed foraging (Allen 
et al. 2006). Defran et al. (1999) postulated that the coastal stock of 
bottlenose dolphins showed significant movement within their home range 
(Central California to Mexico) in search of preferred but patchy 
concentrations of near shore prey (i.e., croakers and surfperch). After 
finding concentrations of prey, animals may then forage within a more 
limited spatial extent to take advantage of this local accumulation 
until such time that prey abundance is reduced after which the dolphins 
once again shift location over larger distances (Defran et al. 1999). 
Bearzi (2005) and Bearzi et al. (2009) also noted little site fidelity 
from coastal bottlenose dolphins in Santa Monica Bay, California, and 
that these animals were highly mobile with up to 69 percent of their 
time spent in travel and dive-travel mode and only 5 percent of the 
time in feeding behaviors.
    Group size of the California coastal stock of bottlenose dolphins 
has been reported to range from 1 to 57 dolphins (Bearzi 2005), 
although mean pod sizes were around 19.8 (Defran and Weller 1999) and 
10.1 (Bearzi 2005). An at-sea density estimate of 0.202 animals/km\2\ 
was used for acoustic impact modeling for both the warm and cold 
seasons as derived in National Center for Coastal Ocean Science (2005).
    Based on photographic mark-recapture surveys conducted along the 
San Diego coast in 2004 and 2005, population size for the California 
Coastal Stock of the bottlenose dolphin is estimated to be 323 
individuals (CV = 0.13, 95% CI 259-430; Dudzik et al. 2005; Carretta et 
al. 2010). This estimate does not reflect that approximately 35 percent 
of dolphins encountered lack identifiable dorsal fin marks (Defran and 
Weller 1999). If 35 percent of all animals lack distinguishing marks, 
then the true population size would be closer to 450-500 animals 
(Carretta et al. 2010). The California Coastal Stock of bottlenose 
dolphins is not listed under the ESA, and is not considered a strategic 
stock under the MMPA.

Gray Whale

    The Eastern North Pacific population is found from the upper Gulf 
of California (Tershy and Breese 1991), south to the tip of Baja 
California, and up the Pacific coast of North America to the Chukchi 
and Beaufort seas. There is a pronounced seasonal north-south 
migration. The eastern North Pacific population summers in the shallow 
waters of the northern Bering Sea, the Chukchi Sea, and the western 
Beaufort Sea (Rice and Wolman 1971). The northern Gulf of Alaska (near 
Kodiak Island) is also considered a feeding area; some gray whales 
occur there year-round (Moore et al. 2007). Some individuals spend the 
summer feeding along the Pacific coast from southeastern Alaska to 
central California (Sumich 1984; Calambokidis et al. 1987; 2002). 
Photo-identification studies indicate that gray whales move widely 
along the Pacific coast and are often not sighted in the same area each 
year (Calambokidis et al. 2002). In October and November, the whales 
begin to migrate southeast through Unimak Pass and follow the shoreline 
south to breeding grounds on the west coast of Baja California and the 
southeastern Gulf of California (Braham 1984; Rugh 1984). The average 
gray whale migrates 4,050 to 5,000 nm (7,500 to 10,000 km) at a rate of 
80 nm (147 km) per day (Rugh et al. 2001; Jones and Swartz 2002). 
Although some calves are born along the coast of California (Shelden et 
al. 2004), most are born in the shallow, protected waters on the 
Pacific coast of Baja California from Morro de Santo Domingo (28[deg]N) 
south to Isla Creciente (24[deg]N) (Urb[aacute]n et al. 2003). Main 
calving sites are Laguna Guerrero Negro, Laguna Ojo de Liebre, Laguna 
San Ignacio, and Estero Soledad (Rice et al. 1981).
    A group of gray whales known as the Pacific Coast Feeding 
Aggregation (PCFA) feeds along the Pacific coast between southeastern 
Alaska and northern to central California throughout the summer and 
fall (NMFS 2001; Calambokidis et al. 2002; Calambokidis et al. 2004). 
The gray whales in this feeding aggregation are a relatively small 
proportion (a few hundred individuals) of the overall eastern North 
Pacific population and typically arrive and depart from these feeding 
grounds concurrently with the migration to and from the wintering 
grounds (Calambokidis et al. 2002; Allen and Angliss 2010). Although 
some site fidelity is known to occur, there is generally considerable 
inter-annual variation since many individuals do not return to the same 
feeding site in successive years (Calambokidis et al. 2000; 
Calambokidis et al. 2004).
    The Eastern North Pacific stock of gray whale transits through 
Southern California during its northward and southward migrations 
between December and June. Gray whales follow three routes from within 
15 to 200 km from shore (Bonnell and Dailey 1993). The nearshore route 
follows the shoreline between Point Conception and Point Vicente but 
includes a more direct line from Santa Barbara to Ventura and across 
Santa Monica Bay. Around Point Vicente or Point Fermin, some whales 
veer south towards Santa Catalina Island and return to the nearshore 
route near Newport Beach. Others join the inshore route that includes 
the northern chain of the Channel Islands along Santa Cruz Island and 
Anacapa Island and east along the Santa Cruz Basin to Santa Barbara 
Island and the Osborn Bank. From here, gray whales migrate east 
directly to Santa Catalina Island and then to Point Loma or Punta 
Descanso or southeast to San Clemente

[[Page 24166]]

Island and on to the area near Punta Banda. A significant portion of 
the Eastern North Pacific stock passes by San Clemente Island and its 
associated offshore waters (Carretta et al. 2000). The offshore route 
follows the undersea ridge from Santa Rosa Island to the mainland shore 
of Baja California and includes San Nicolas Island and Tanner and 
Cortes banks (Bonnell and Dailey 1993).
    Peak abundance of gray whales off the coast of San Diego is 
typically January during the southward migration and in March during 
the migration north, although females with calves, which depart Mexico 
later than males or females without calves, can be sighted from March 
through May or June (Leatherwood 1974; Poole 1984; Rugh et al. 2001; 
Stevick et al. 2002; Angliss and Outlaw 2008). Gray whales would be 
expected to be infrequent migratory transients within the out portions 
of SSTC only during cold-water months (Carretta et al. 2000). Migrating 
gray whales that might infrequently transit through the SSTC would not 
be expected to forage, and would likely be present for less than two 
hours at typical travel speeds of 3 knots (approximately 3.5 miles per 
hour) (Perryman et al. 1999; Mate and Urb[aacute]n-Ramirez 2003). A 
mean group size of 2.9 gray whales was reported for both coastal (16 
groups) and non-coastal (15 groups) areas around San Clemente Island 
(Carretta et al. 2000). The largest group reported was nine animals. 
The largest group reported by U.S. Navy (1998) was 27 animals. Gray 
whales would not be expected in the SSTC from July through November 
(Rice et al. 1981), and are excluded from warm season analysis. Even 
though gray whale transitory occurrence is infrequent along SSTC a cold 
season density is estimated at 0.014 animals per km\2\ for purposes of 
conservative analysis.
    Systematic counts of gray whales migrating south along the central 
California coast have been conducted by shore-based observers at 
Granite Canyon most years since 1967. The population size of the 
Eastern North Pacific gray whale stock has been increasing over the 
past several decades at a rate approximately between 2.5 to 3.3 percent 
per year since 1967. The most recent abundance estimates are based on 
the National Marine Fisheries Service's population estimate of 19,126 
individuals as reported in Allen and Angliss (2010).
    In 1994, due to steady increases in population abundance, the 
Eastern North Pacific stock of gray whales was removed from the List of 
Endangered and Threatened Wildlife, as it was no longer considered 
endangered or threatened under the ESA (Allen and Angliss 2010). The 
Eastern North Pacific stock of gray whale is not considered a strategic 
stock under the MMPA. Even though the stock is within Optimal 
Sustainable Population, abundance will rise and fall as the population 
adjusts to natural and man-caused factors affecting the carrying 
capacity of the environment (Rugh et al. 2005). In fact, it is expected 
that a population close to or at the carrying capacity of the 
environment will be more susceptible to fluctuations in the environment 
(Moore et al. 2001).

Long-Beaked Common Dolphin, California Stock

    Long-beaked common dolphins are found year-round in the waters off 
California (Carretta et al. 2000; Bearzi 2005; DoN 2009, 2010). The 
distribution and abundance of long-beaked common dolphins appears to be 
variable based on inter-annual and seasonal time scales (Dohl et al. 
1986; Heyning and Perrin 1994; Barlow 1995; Forney et al. 1995; Forney 
and Barlow 2007). As oceanographic conditions change, long-beaked 
common dolphins may move between Mexican and U.S. waters, and therefore 
a multi-year average abundance estimate is the most appropriate for 
management within the U.S. waters (Carretta et al. 2010). California 
waters represent the northern limit for this stock and animal's likely 
movement between U.S. and Mexican waters. No information on trends in 
abundance is available for this stock because of high inter-annual 
variability in line-transect abundance estimates (Carretta et al. 
2010). Heyning and Perrin (1994) detected changes in the proportion of 
short-beaked to long-beaked common dolphins stranding along the 
California coast, with the short-beaked common dolphin stranding more 
frequently prior to the 1982-83 El Ni[ntilde]o (which increased water 
temperatures off California), and the long-beaked common dolphin more 
frequently observed for several years afterwards. Thus, it appears that 
both relative and absolute abundance of these species off California 
may change with varying oceanographic conditions (Carretta et al. 
2010). Common dolphin distributions may be related to bathymetry (Hui 
1979). Long-beaked common dolphins are usually found within 50 nautical 
miles (nm) (92.5 km) of shore with significantly more occurrence near 
canyons, escarpments, and slopes (Heyning and Perrin 1994; Barlow et 
al. 1997; Bearzi 2005, 2006). Group size ranges from less than a dozen 
to several thousand individuals (Barlow and Forney 2007; Barlow et al. 
2010).
    Recent anecdotal accounts from Navy Explosive Ordnance Disposal 
(EOD) divers remark on periodic sightings of large dolphin pods within 
the more seaward portions of the SSTC that are likely comprised of 
long-beaked common dolphin. During SSTC Navy-funded marine mammal 
monitoring conducted over 2 days in November 2012, there were confirmed 
sightings of long-beaked common dolphin pods in the outer portions of 
the SSTC in about 75 feet of water. Unlike the large congregated 
schools common to this species, the long-beaked common dolphins seen in 
November were in widely dispersed small sub-groups with one to five 
dolphins per group. Individuals and small groups were seen chasing bait 
fish to the surface and foraging. The dolphins were observed over a 
one-hour period and eventually left the SSTC heading seaward.
    Sparse information is available on the life history of long-beaked 
common dolphins, however, some information is provided for short-beaked 
common dolphins which may also apply to long-beaked dolphins. North 
Pacific short-beaked common dolphin females and males reach sexual 
maturity at roughly 8 and 10 years, respectively (Ferrero and Walker 
1995). Peak calving season for common dolphins in the eastern North 
Pacific may be spring and early summer (Forney 1994). Barlow (2010) 
reported average group size for long-beaked common dolphins within a 
Southern California-specific stratum as 195 individuals from a 2008 
survey along the U.S. West Coast. The geometric mean abundance estimate 
in NMFS' annual stock assessment for the entire California stock of 
long-beaked common dolphins, based on two ship surveys conducted in 
2005 and 2008, is 27,046 (CV = 0.59) (Forney 2007; Barlow 2010; 
Carretta et al. 2010). Using a more stratified approach, Barlow et al. 
(2010) estimated abundance within a Southern California-specific strata 
of 16,480 (CV = 0.41) long-beaked common dolphins based on analysis of 
pooled sighting data from 1991-2008. Long-beaked common dolphins are 
not listed under the ESA, and are not considered a strategic stock 
under the MMPA.

Pacific White-sided Dolphin, California/Oregon/Washington Stock

    While Pacific white-sided dolphins could potentially occur year-
round in Southern California, surveys suggest a seasonal north-south 
movement in the eastern North Pacific, with animals found primarily off 
California during the colder water months and shifting

[[Page 24167]]

northward into Oregon and Washington as water temperatures increase 
during late spring and summer (Green et al. 1992, 1993; Forney 1994; 
Forney and Barlow 2007; Barlow 2010). Salvadeo et al. (2010) propose 
that increased global warming may increase a northward shift in Pacific 
white-sided dolphins. The Pacific white-sided dolphin is most common in 
waters over the continental shelf and slope, however, sighting records 
and captures in pelagic driftnets indicate that this species also 
occurs in oceanic waters well beyond the shelf and slope (Leatherwood 
et al. 1984; DoN 2009, 2010). Soldevilla et al. (2010a) reported the 
possibility of two distinct eco-types of Pacific white-sided dolphins 
occurring in Southern California based on passive acoustic detection of 
two distinct echolocation click patterns. No population trends have 
been observed in California or adjacent waters. Barlow (2010) reported 
average group size for Pacific white-sided dolphins within a Southern 
California-specific stratum as 17 from a 2008 survey along the U.S. 
West Coast. The size of the entire California/Oregon/Washington Stock 
is estimated to be 26,930 (CV = 0.28) individuals (Forney 2007, Barlow, 
2010). Using a more stratified approach, Barlow et al. (2010) estimated 
abundance within a Southern California-specific strata of 1,914 (CV = 
0.39) Pacific white-sided dolphins based on analysis of pooled sighting 
data from 1991-2008. Pacific white-sided dolphins are not listed under 
the ESA, and are not considered a strategic stock under the MMPA.

Risso's Dolphin, California/Oregon/Washington Stock

    Off the U.S. West coast, Risso's dolphins are commonly seen on the 
shelf off Southern California and in slope and offshore waters of 
California, Oregon and Washington (Soldevilla et al. 2010b; Carretta et 
al. 2010). Animals found off California during the colder water months 
are thought to shift northward into Oregon and Washington as water 
temperatures increase in late spring and summer (Green et al. 1992). 
The southern end of this population's range is not well documented, but 
previous surveys have shown a conspicuous 500 nm distributional gap 
between these animals and Risso's dolphins sighted south of Baja 
California and in the Gulf of California (Mangels and Gerrodette 1994). 
Thus this population appears distinct from animals found in the eastern 
tropical Pacific and the Gulf of California (Carretta et al. 2010). As 
oceanographic conditions vary, Risso's dolphins may spend time outside 
the U.S. Exclusive Economic Zone. Barlow (2010) reported average group 
size for Risso's dolphins within a Southern California-specific stratum 
as 23 from a 2008 survey along the U.S. West Coast. The size of the 
California/Oregon/Washington Stock is estimated to be 6,272 (CV = 0.30) 
individuals (Forney 2007; Barlow 2010; Carretta et al. 2010). Using a 
more stratified approach, Barlow et al. (2010) estimated abundance 
within a Southern California-specific strata of 3,974 (CV = 0.39) 
Risso's dolphins based on analysis of pooled sighting data from 1991-
2008. Risso's dolphins are not listed under the ESA, and are not 
considered a strategic stock under the MMPA.

Short-Beaked Common Dolphin, California/Oregon/Washington Stock

    Short-beaked common dolphins are the most abundant cetacean off 
California, and are widely distributed between the coast and at least 
300 nm distance from shore (Dohl et al. 1981; Forney et al. 1995; 
Barlow 2010; Carretta et al. 2010). Along the U.S. West Coast, portions 
of the short-beaked common dolphins' distribution overlap with that of 
the long-beaked common dolphin. The northward extent of short-beaked 
common dolphin distribution appears to vary inter-annually and with 
changing oceanographic conditions (Forney and Barlow 1998). Barlow 
(2010) reported average group size for short-beaked common dolphins 
within a Southern California-specific stratum as 122 from a 2008 survey 
along the U.S. West Coast. The size of the California/Oregon/Washington 
Stock is estimated to be 411,211 (CV = 0.21) individuals (Carretta et 
al. 2010). Using a more stratified approach, Barlow et al. (2010) 
estimated abundance within a Southern California-specific strata of 
152,000 (CV = 0.17) short-beaked common dolphins based on analysis of 
pooled sighting data from 1991-2008. Short-beaked common dolphins are 
not listed under the ESA, and are not considered a strategic stock 
under the MMPA.

Potential Effects on Marine Mammals

    Anticipated impacts resulting from the Navy's proposed SSTC 
training activities include disturbance from underwater detonation 
events and pile driving from ELCAS training events if marine mammals 
are in the vicinity of these action areas.

Impacts From Anthropogenic Noise

    Marine mammals exposed to high intensity sound repeatedly or for 
prolonged periods can experience hearing threshold shift (TS), which is 
the loss of hearing sensitivity at certain frequency ranges (Kastak et 
al. 1999; Schlundt et al. 2000; Finneran et al. 2002; 2005). TS can be 
permanent (PTS), in which case the loss of hearing sensitivity is 
unrecoverable, or temporary (TTS), in which case the animal's hearing 
threshold will recover over time (Southall et al. 2007). Since marine 
mammals depend on acoustic cues for vital biological functions, such as 
orientation, communication, finding prey, and avoiding predators, 
marine mammals that suffer from PTS or TTS will have reduced fitness in 
survival and reproduction, either permanently or temporarily. Repeated 
noise exposure that leads to TTS could cause PTS.
    Although no marine mammals have been shown to experience TTS or PTS 
as a result of being exposed to pile driving activities, experiments on 
a bottlenose dolphin and beluga whale (Delphinapterus leucas) showed 
that exposure to a single watergun impulse at a received level of 207 
kPa (or 30 psi) peak-to-peak (p-p), which is equivalent to 228 dB re 1 
[mu]Pa (p-p), resulted in a 7 and 6 dB TTS in the beluga whale at 0.4 
and 30 kHz, respectively. Thresholds returned to within 2 dB of the 
pre-exposure level within 4 minutes of the exposure (Finneran et al. 
2002). No TTS was observed in the bottlenose dolphin. Although the 
source level of pile driving from one hammer strike is expected to be 
much lower than the single watergun impulse cited here, animals being 
exposed for a prolonged period to repeated hammer strikes could receive 
more noise exposure in terms of SEL than from the single watergun 
impulse in the aforementioned experiment (Finneran et al. 2002).
    However, in order for marine mammals to experience TTS or PTS, the 
animals have to be close enough to be exposed to high intensity noise 
levels for prolonged period of time. Current NMFS standards for 
preventing injury from PTS and TTS is to require shutdown or power-down 
of noise sources when a cetacean species is detected within the 
isopleths corresponding to SPL at received levels equal to or higher 
than 180 dB re 1 [mu]Pa (rms), or a pinniped species at 190 dB re 1 
[mu]Pa (rms). Based on the best scientific information available, these 
SPLs are far below the threshold that could cause TTS or the onset of 
PTS. Certain mitigation measures proposed by the Navy, discussed below, 
can effectively prevent the onset of TS in marine mammals, including 
establishing safety zones and monitoring safety zones during the 
training exercise.
    In addition, chronic exposure to excessive, though not high-
intensity, noise could cause masking at particular

[[Page 24168]]

frequencies for marine mammals that utilize sound for vital biological 
functions. Masking can interfere with detection of acoustic signals 
such as communication calls, echolocation sounds, and environmental 
sounds important to marine mammals. Therefore, like TS, marine mammals 
whose acoustical sensors or environment are being masked are also 
impaired from maximizing their performance fitness in survival and 
reproduction.
    Masking occurs at the frequency band which the animals utilize. 
Therefore, since noise generated from the proposed underwater 
detonation and pile driving and removal is mostly concentrated at low 
frequency ranges, it may have less effect on species with mid- and 
high-frequency echolocation sounds. However, lower frequency man-made 
noises are more likely to affect detection of communication calls and 
other potentially important natural sounds such as surf and prey noise. 
It may also affect communication signals when they occur near the noise 
band used by the animals and thus reduce the communication space of 
animals (e.g., Clark et al. 2009) and cause increased stress levels 
(e.g., Foote et al. 2004; Holt et al. 2009).
    Masking can potentially impact marine mammals at the individual, 
population, community, or even ecosystem levels (instead of individual 
levels caused by TS). Masking affects both senders and receivers of the 
signals and can potentially have long-term chronic effects on marine 
mammal species and populations in certain situations. Recent science 
suggests that low-frequency ambient sound levels have increased by as 
much as 20 dB (more than 3 times in terms of SPL) in the world's ocean 
from pre-industrial periods, and most of these increases are from 
distant shipping (Hildebrand 2009). All anthropogenic noise sources, 
such as those from underwater explosions and pile driving, contribute 
to the elevated ambient noise levels and, thus intensify masking. 
However, single detonations are unlikely to contribute much to masking.
    Since all of the underwater detonation events and ELCAS events are 
planned in a very shallow water situation (wave length >> water depth), 
where low-frequency propagation is not efficient, the noise generated 
from these activities is predominantly in the low-frequency range and 
is not expected to contribute significantly to increased ocean ambient 
noise.
    Finally, exposure of marine mammals to certain sounds could lead to 
behavioral disturbance (Richardson et al. 1995). Behavioral responses 
to exposure to sound and explosions can range from no observable 
response to panic, flight and possibly more significant responses as 
discussed previously (Richardson et al. 1995; Southall et al. 2007). 
These responses include: changing durations of surfacing and dives, 
number of blows per surfacing, or moving direction and/or speed; 
reduced/increased vocal activities, changing/cessation of certain 
behavioral activities (such as socializing or feeding); visible startle 
response or aggressive behavior (such as tail/fluke slapping or jaw 
clapping), avoidance of areas where noise sources are located, and/or 
flight responses (e.g., pinnipeds flushing into water from haul-outs or 
rookeries) (reviews by Richardson et al. 1995; Wartzok et al. 2003; Cox 
et al. 2006; Nowacek et al. 2007; Southall et al. 2007).
    The biological significance of many of these behavioral 
disturbances is difficult to predict, especially if the detected 
disturbances appear minor. However, the consequences of behavioral 
modification could be expected to be biologically significant if the 
change affects growth, survival, and reproduction. Some of these 
significant behavioral modifications include:
     Drastic change in diving/surfacing patterns (such as those 
thought to be causing beaked whale stranding due to exposure to 
military mid-frequency tactical sonar);
     Habitat abandonment due to loss of desirable acoustic 
environment; and
     Cease feeding or social interaction.
    For example, at the Guerreo Negro Lagoon in Baja California, 
Mexico, which is one of the important breeding grounds for Pacific gray 
whales, shipping and dredging associated with a salt works may have 
induced gray whales to abandon the area through most of the 1960s 
(Bryant et al. 1984). After these activities stopped, the lagoon was 
reoccupied, first by single whales and later by cow-calf pairs.
    The onset of behavioral disturbance from anthropogenic noise 
depends on both external factors (characteristics of noise sources and 
their paths) and the receiving animals (hearing, motivation, 
experience, demography) and is also difficult to predict (Southall et 
al. 2007). However, the proposed action area is not believed to be a 
prime habitat for marine mammals, nor is it considered an area 
frequented by marine mammals. Therefore, behavioral disturbances that 
could result from anthropogenic construction noise associated with the 
Navy's proposed training activities are expected to affect only a small 
number of marine mammals on an infrequent basis.

Impacts from Underwater Detonations at Close Range

    In addition to noise induced disturbances and harassment, marine 
mammals could be killed or injured by underwater explosions due to the 
impacts to air cavities, such as the lungs and bubbles in the 
intestines, from the shock wave (Elsayed 1997; Elsayed and Gorbunov 
2007). The criterion for mortality and non-auditory injury used in MMPA 
take authorization is the onset of extensive lung hemorrhage and slight 
lung injury or ear drum rupture, respectively (see Table 3). Extensive 
lung hemorrhage is considered debilitating and potentially fatal as a 
result of air embolism or suffocation. In the Incidental Harassment 
Authorization application, all marine mammals within the calculated 
radius for 1 percent probability of onset of extensive lung injury 
(i.e., onset of mortality) were counted as lethal exposures. The range 
at which 1 percent probability of onset of extensive lung hemorrhage is 
expected to occur is greater than the ranges at which 50 percent to 100 
percent lethality would occur from closest proximity to the charge or 
from presence within the bulk cavitation region. (The region of bulk 
cavitation is an area near the surface above the detonation point in 
which the reflected shock wave creates a region of cavitation within 
which smaller animals would not be expected to survive). Because the 
range for onset of extensive lung hemorrhage for smaller animals 
exceeds the range for bulk cavitation and all more serious injuries, 
all smaller animals within the region of cavitation and all animals 
(regardless of body mass) with more serious injuries than onset of 
extensive lung hemorrhage were accounted for in the lethal exposures 
estimate. The calculated maximum ranges for onset of extensive lung 
hemorrhage depend upon animal body mass, with smaller animals having 
the greatest potential for impact, as well as water column temperature 
and density.
    However, due to the small detonation that would be used in the 
proposed SSTC training activities and the resulting small safety zones 
to be monitored and mitigated for marine mammals in the vicinity of the 
proposed action area, it is highly unlikely that marine mammals would 
be killed or injured by underwater detonations.

Impact Criteria and Thresholds

    The effects of an at-sea explosion or pile driving on a marine 
mammal

[[Page 24169]]

depend on many factors, including the size, type, and depth of both the 
animal and the explosive charge/pile being driven; the depth of the 
water column; the standoff distance between the charge/pile and the 
animal; and the sound propagation properties of the environment. 
Potential impacts can range from brief acoustic effects (such as 
behavioral disturbance), tactile perception, physical discomfort, and 
slight injury of the internal organs and the auditory system, to death 
of the animal (Yelverton et al. 1973; O'Keeffe and Young 1984; DoN 
2001). Non-lethal injury includes slight injury to internal organs and 
the auditory system; however, delayed lethality can be a result of 
individual or cumulative sub-lethal injuries (DoN 2001). Short-term or 
immediate lethal injury would result from massive combined trauma to 
internal organs as a direct result of proximity to the point of 
detonation or pile driving (DoN 2001).
    This section summarizes the marine mammal impact criteria used for 
the subsequent modeled calculations. Several standard acoustic metrics 
(Urick 1983) are used to describe the thresholds for predicting 
potential physical impacts from underwater pressure waves:
     Total energy flux density or Sound Exposure Level (SEL). 
For plane waves (as assumed here), SEL is the time integral of the 
instantaneous intensity, where the instantaneous intensity is defined 
as the squared acoustic pressure divided by the characteristic 
impedance of sea water. Thus, SEL is the instantaneous pressure 
amplitude squared, summed over the duration of the signal and has dB 
units referenced to 1 re [mu]Pa\2\-s.
     \1/3\-octave SEL. This is the SEL in a \1/3\-octave 
frequency band. A \1/3\-octave band has upper and lower frequency 
limits with a ratio of 21:3, creating bandwidth limits of about 23 
percent of center frequency.
     Positive impulse. This is the time integral of the initial 
positive pressure pulse of an explosion or explosive-like wave form. 
Standard units are Pa-s, but psi-ms also are used.
     Peak pressure. This is the maximum positive amplitude of a 
pressure wave, dependent on charge mass and range. Units used here are 
psi, but other units of pressure, such as [mu]Pa and Bar, also are 
used.
    Harassment Threshold for Sequential Underwater Detonations--There 
may be rare occasions when sequential underwater detonations are part 
of a static location event. Sequential detonations are more than one 
detonation within a 24-hour period in a geographic location where 
harassment zones overlap. For sequential underwater detonations, 
accumulated energy over the entire training time is the natural 
extension for energy thresholds since energy accumulates with each 
subsequent shot.
    For sequential underwater detonations, the acoustic criterion for 
behavioral harassment is used to account for behavioral effects 
significant enough to be judged as harassment, but occurring at lower 
sound energy levels than those that may cause TTS. The behavioral 
harassment threshold is based on recent guidance from NMFS (NMFS 2009a; 
2009b) for the energy-based TTS threshold. The research on pure tone 
exposures reported in Schlundt et al. (2000) and Finneran and Schlundt 
(2004) provided the pure-tone threshold of 192 dB as the lowest TTS 
value. The resulting TTS threshold for explosives is 182 dB re 1 
[mu]Pa\2\-s in any \1/3\ octave band. As reported by Schlundt et al. 
(2000) and Finneran and Schlundt (2004), instances of altered behavior 
in the pure tone research generally began 5 dB lower than those causing 
TTS. The behavioral harassment threshold is therefore derived by 
subtracting 5 dB from the 182 dB re 1 [mu]Pa\2\-s in any \1/3\ octave 
band threshold, resulting in a 177 dB re 1 [mu]Pa\2\-s behavioral 
disturbance harassment threshold for multiple successive explosives 
(Table 3).
    Criteria for ELCAS Pile Driving and Removal--Since 1997, NMFS has 
been using generic sound exposure thresholds to determine when an 
activity in the ocean that produces impact sound (i.e., pile driving) 
results in potential take of marine mammals by harassment (70 FR 1871). 
Current NMFS criteria (70 FR 1871) regarding exposure of marine mammals 
to underwater sounds is that cetaceans exposed to sound pressure levels 
(SPLs) of 180 dB root mean squared (dBrms in units of dB re 
1 [mu]Pa) or higher and pinnipeds exposed to 190 dBrms or 
higher are considered to have been taken by Level A (i.e., injurious) 
harassment. Marine mammals (cetaceans and pinnipeds) exposed to impulse 
sounds (e.g., impact pile driving) of 160 dBrms but below 
Level A thresholds (i.e., 180 or 190 dB) are considered to have been 
taken by Level B behavioral harassment. Marine mammals (cetaceans and 
pinnipeds) exposed to non-impulse noise (e.g., vibratory pile driving) 
at received levels of 120 dB RMS or above are considered to have been 
taken by Level B behavioral harassment (Table 3).

   Table 3--Effects Criteria for Underwater Detonations and ELCAS Pile
                            Driving/Removal.
------------------------------------------------------------------------
                                       Criterion
            Criterion                 Definition           Threshold
------------------------------------------------------------------------
                      Underwater Explosive Criteria
------------------------------------------------------------------------
Mortality.......................  Onset of severe     30.5 psi-ms
                                   lung injury (1      (positive
                                   percent             impulse).
                                   probability of
                                   mortality).
Level A Harassment (Injury).....  Slight lung         13.0 psi-ms
                                   injury; or.         (positive
                                                       impulse).
                                  50 percent of       205 dB re 1
                                   marine mammals      [mu]Pa\2\-s
                                   would experience   (full spectrum
                                   ear drum rupture;   energy).
                                   and 30 percent
                                   exposed sustain
                                   PTS.
Level B Harassment..............  TTS (dual           23 psi (peak
                                   criteria).          pressure;
                                                       explosives <2,000
                                                       lbs), or
                                                      182 dB re 1
                                                       [mu]Pa\2\-s (peak
                                                       \1/3\ octave
                                                       band).
                                  (sequential         177 dB re 1
                                   detonations only).  [mu]Pa\2\-s.
------------------------------------------------------------------------
                     Pile Driving/Removal Criteria
------------------------------------------------------------------------
Level A Harassment..............  Pinniped only: PTS  190 dBrms re 1
                                   caused by           [mu]Pa.
                                   repeated exposure
                                   to received
                                   levels that cause
                                   TTS.
                                  Cetacean only: PTS  180 dBrms re 1
                                   caused by           [mu]Pa.
                                   repeated exposure
                                   to received
                                   levels that cause
                                   TTS.
Level B Behavioral Harassment...  Cetacean only:      160 dBrms re 1
                                   Impulse noise;      [mu]Pa.
                                   Behavioral
                                   modification of
                                   animals.

[[Page 24170]]

 
                                  Pinniped only: Non- 190 dBrms re 1
                                   impulse noise;      [mu]Pa.
                                   Behavioral
                                   modification of
                                   animals.
------------------------------------------------------------------------

Assessing Harassment from Underwater Detonations

    Underwater detonations produced during SSTC training events 
represent a single, known source. Chemical explosives create a bubble 
of expanding gases as the material detonates. The bubble can oscillate 
underwater or, depending on charge-size and depth, be vented to the 
surface in which case there is no bubble-oscillation with its 
associated low-frequency energy. Explosions produce very brief, 
broadband pulses characterized by rapid rise-time, great zero-to-peak 
pressures, and intense sound, sometimes described as impulse. Close to 
the explosion, there is a very brief, great-pressure acoustic wave-
front. The impulse's rapid onset time, in addition to great peak 
pressure, can cause auditory impacts, although the brevity of the 
impulse can include less SEL than expected to cause impacts. The 
transient impulse gradually decays in magnitude as it broadens in 
duration with range from the source. The waveform transforms to 
approximate a low-frequency, broadband signal with a continuous sound 
energy distribution across the spectrum. In addition, underwater 
explosions are relatively brief, transitory events when compared to the 
existing ambient noise within the San Diego Bay and at the SSTC.
    The impacts of an underwater explosion to a marine mammal are 
dependent upon multiple factors including the size, type, and depth of 
both the animal and the explosive. Depth of the water column and the 
distance from the charge to the animal also are determining factors as 
are boundary conditions that influence reflections and refraction of 
energy radiated from the source. The severity of physiological effects 
generally decreases with decreasing exposure (impulse, sound exposure 
level, or peak pressure) and/or increasing distance from the sound 
source. The same generalization is not applicable for behavioral 
effects, because they do not depend solely on sound exposure level. 
Potential impacts can range from brief acoustic effects, tactile 
perception, and physical discomfort to both lethal and non-lethal 
injuries. Disturbance of ongoing behaviors could occur as a result of 
non-injurious physiological responses to both the acoustic signature 
and shock wave from the underwater explosion. Non-lethal injury 
includes slight injury to internal organs and auditory system. The 
severity of physiological effects generally decreases with decreasing 
sound exposure and/or increasing distance from the sound source. 
Injuries to internal organs and the auditory system from shock waves 
and intense impulsive noise associated with explosions can be 
exacerbated by strong bottom-reflected pressure pulses in reverberant 
environments (Gaspin 1983; Ahroon et al. 1996). Nevertheless, the 
overall size of the explosives used at the SSTC is much smaller than 
those used during larger Fleet ship and aircraft training events.
    All underwater detonations proposed for SSTC were modeled as if 
they will be conducted in shallow water of 24 to 72 feet, including 
those that would normally be conducted in very shallow water (VSW) 
depths of zero to 24 feet. Modeling in deeper than actual water depths 
causes the modeled results to be more conservative (i.e., it 
overestimates propagation and potential exposures) than if the 
underwater detonations were modeled at their actual, representative 
depths when water depth is less than 24 feet.
    The Navy's underwater explosive effects simulation requires six 
major process components:
     A training event description including explosive type;
     Physical oceanographic and geoacoustic data for input into 
the acoustic propagation model representing seasonality of the planned 
operation;
     Biological data for the area including density (and 
multidimensional animal movement for those training events with 
multiple detonations);
     An acoustic propagation model suitable for the source type 
to predict impulse, energy, and peak pressure at ranges and depths from 
the source;
     The ability to collect acoustic and animal movement 
information to predict exposures for all animals during a training 
event (dosimeter record); and
     The ability for post-operation processing to evaluate the 
dosimeter exposure record and calculate exposure statistics for each 
species based on applicable thresholds.
    An impact model, such as the one used for the SSTC analysis, 
simulates the conditions present based on location(s), source(s), and 
species parameters by using combinations of embedded models (Mitchell 
et al. 2008). The software package used for SSTC consists of two main 
parts: An underwater noise model and bioacoustic impact model (Lazauski 
et al. 1999; Lazauski and Mitchell 2006; Lazauski and Mitchell 2008).
    Location-specific data characterize the physical and biological 
environments while exercise-specific data construct the training 
operations. The quantification process involves employment of modeling 
tools that yield numbers of exposures for each training operation. 
During modeling, the exposures are logged in a time-step manner by 
virtual dosimeters linked to each simulated animal. After the operation 
simulation, the logs are compared to exposure thresholds to produce raw 
exposure statistics. It is important to note that dosimeters only were 
used to determine exposures based on energy thresholds, not impulse or 
peak pressure thresholds. The analysis process uses quantitative 
methods and identifies immediate short-term impacts of the explosions 
based on assumptions inherent in modeling processes, criteria and 
thresholds used, and input data. The estimations should be viewed with 
caution, keeping in mind that they do not reflect measures taken to 
avoid these impacts (i.e., mitigations). Ultimately, the goals of this 
acoustic impact model were to predict acoustic propagation, estimate 
exposure levels, and reliably predict impacts.
    Predictive sound analysis software incorporates specific 
bathymetric and oceanographic data to create accurate sound field 
models for each source type. Oceanographic data such as the sound speed 
profiles, bathymetry, and seafloor properties directly affect the 
acoustic propagation model. Depending on location, seasonal variations, 
and the oceanic current flow, dynamic oceanographic attributes (e.g., 
sound speed profile) can change dramatically with time. The sound field 
model is embedded in the impact model as a core feature used to analyze 
sound and pressure fields associated with SSTC underwater detonations.

[[Page 24171]]

    The sound field model for SSTC detonations was the Reflection and 
Refraction in Multilayered Ocean/Ocean Bottoms with Shear Wave Effects 
(REFMS) model (version 6.03). The REFMS model calculates the combined 
reflected and refracted shock wave environment for underwater 
detonations using a single, generalized model based on linear wave 
propagation theory (Cagniard 1962; Britt 1986; Britt et al. 1991).
    The model outputs include positive impulse, sound exposure level 
(total and in 1/3-octave bands) at specific ranges and depths of 
receivers (i.e., marine mammals), and peak pressure. The shock wave 
consists of two parts, a very rapid onset ``impulsive'' rise to 
positive peak over-pressure followed by a reflected negative under-
pressure rarefaction wave. Propagation of shock waves and sound energy 
in the shallow-water environment is constrained by boundary conditions 
at the surface and seafloor.
    Multiple locations (in Boat Lanes and Echo area) and charge depths 
were used to determine the most realistic spatial and temporal 
distribution of detonation types associated with each training 
operation for a representative year. Additionally, the effect of sound 
on an animal depends on many factors including:
     Properties of the acoustic source(s): Source level (SL), 
spectrum, duration, and duty cycle;
     Sound propagation loss from source to animal, as well as, 
reflection and refraction;
     Received sound exposure measured using well-defined 
metrics;
     Specific hearing;
     Exposure duration; and
     Masking effects of background and ambient noise.
    To estimate exposures sufficient to be considered injury or 
significantly disrupt behavior by affecting the ability of an 
individual animal to grow (e.g., feeding and energetics), survive 
(e.g., behavioral reactions leading to injury or death, such as 
stranding), reproduce (e.g., mating behaviors), and/or degrade habitat 
quality resulting in abandonment or avoidance of those areas, 
dosimeters were attached to the virtual animals during the simulation 
process. Propagation and received impulse, SEL, and peak pressure are a 
function of depth, as well as range, depending on the location of an 
animal in the simulation space.
    A detailed discussion of the computational process for the 
modeling, which ultimately generates two outcomes--the zones of 
influence (ZOIs) and marine mammal exposures, is presented in the 
Navy's IHA application.
    Severity of an effect often is related to the distance between the 
sound source and a marine mammal and is influenced by source 
characteristics (Richardson and Malme 1995). For SSTC, ZOIs were 
estimated for the different charge weights, charge depths, water 
depths, and seasons using the REFMS model as described previously. 
These ZOIs for SSTC underwater detonations by training event are shown 
in Table 4 and conceptually illustrated in Figure 6-5 in the Navy's IHA 
application.
    For single detonations, the ZOIs were calculated using the range 
associated with the onset of TTS based on the Navy REFMS model 
predictions.
    For Multiple Successive Explosive events (i.e., sequential 
detonations) ZOI calculation was based on the range to non-TTS behavior 
disruption. Calculating the zones of influence in terms of total SEL, 
1/3-octave bands SEL, impulse, and peak pressure for sequential (10 sec 
timed) and multiple controlled detonations (>30 minutes) were slightly 
different than the single detonations. For the sequential detonations, 
ZOI calculations considered spatial and temporal distribution of the 
detonations, as well as the effective accumulation of the resultant 
acoustic energy. To calculate the ZOI, sequential detonations were 
modeled such that explosion SEL were summed incoherently to predict 
zones while peak pressure was not.

                                           Table 4--Maximum ZOIs for Underwater Detonation Events at the SSTC
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                        Maximum ZOI (yards)
                                                                         -------------------------------------------------------------------------------
                                                                                        TTS                           Injury                 Mortality
    Underwater detonation training event              Season\*\          -------------------------------------------------------------------------------
                                                                                            182 dB re 1                     205 dB re 1
                                                                              23 psi        [mu]Pa\2\-s     13.0 psi-ms     [mu]Pa\2\-s     30.5 psi-ms
--------------------------------------------------------------------------------------------------------------------------------------------------------
Shock wave action generator (SWAG) (San      Warm.......................              60              20               0               0               0
 Diego Bay--Echo sub-area) 0.033 NEW (74/
 yr).
                                             Cold.......................              40              20               0               0               0
Shock wave action generator (SWAG) (SSTC--   Warm.......................              60              20               0               0               0
 North and South oceanside) 0.033 NEW (16/
 yr).
                                             Cold.......................              40              20               0               0               0
Mine Counter Measure < 20 lbs NEW (29/yr)..  Warm.......................             470             300             360              80              80
                                             Cold.......................             450             340             160              80              80
Floating Mine < 5 lbs NEW (53/yr)..........  Warm.......................             240             160              80              40              20
                                             Cold.......................             260             180              80              40              20
Dive Platoon < 3.5 lbs NEW (sequential) (8/  Warm.......................             210             330              80              90              50
 yr).
                                             Cold.......................             220             370              90              90              50
Unmanned Underwater Vehicle <15 lbs NEW (4/  Warm.......................             440             280             360              80              80
 yr).
                                             Cold.......................             400             320             150              80              80
Marine Mammal Systems < 29 lbs NEW           Warm.......................             380             420             360             140              90
 (sequential) (8/yr).
                                             Cold.......................             450             470             170             140              90
Marine Mammal Systems < 29 lbs NEW (8/yr)..  Warm.......................             400             330             360             100              90
                                             Cold.......................             490             370             170             100              90
Mine Neutralization < 3.5 lbs NEW            Warm.......................             210             330              80              90              50
 (sequential) (4/yr).
                                             Cold.......................             230             370              90              90              50

[[Page 24172]]

 
Surf Zone Training and Evaluation < 20 lbs   Warm.......................             470             300             160              80              80
 NEW (2/yr).
                                             Cold.......................             450             340             160              80              80
Unmanned Underwater Vehicle Neutralization   Warm.......................             220             180              80              60              50
 < 3.6 lbs NEW (sequential) (4/yr).
                                             Cold.......................             230             180              90              60              50
Airborne Mine Neutralization System < 3.5    Warm.......................             220             170              80              40              40
 lbs NEW (10/yr).
                                             Cold.......................             230             180              80              40              40
Qualification/Certification < 13.8 lbs NEW   Warm.......................             330             330             140             100              80
 (sequential) (8/yr).
                                             Cold.......................             360             370             140             100              80
Qualification/Certification < 25.5 lbs NEW   Warm.......................             420             330             300              90              90
 (4/yr).
                                             Cold.......................             470             360             170              90              90
Naval Special Warfare Demolition Training <  Warm.......................             360             240             160              80              40
 10 lbs NEW (4/yr).
                                             Cold.......................             360             250             160              80              40
Naval Special Warfare Demolition Training <  Warm.......................             220             180              80              60              50
 3.6 lbs NEW (4/yr).
                                             Cold.......................             230             180              90              60              50
Navy Special Warfare SEAL Delivery Vehicle   Warm.......................             360             240             160              80              40
 < 10 lbs NEW (40/yr).
                                             Cold.......................             360             250             160              80              40
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Warm: November-April; cold: May-October.

    In summary, all ZOI radii were strongly influenced by charge size 
and placement in the water column, and only slightly by the environment 
variables. Detailed information on ZOI determination for very shallow 
water is provided in section 6 of the Navy's LOA application.
    The anticipated impacts from marine mammal exposure to explosive 
detonations and pile-driving remain unchanged from the IHA issued to 
the Navy in 2012 (77 FR 43238, July 24, 2012).

Proposed Mitigation Measures

    In order to issue an incidental take authorization under section 
101(a)(5)(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, and on the availability of such species 
or stock for taking for certain subsistence uses.
    The take estimates provided later in this document represent the 
maximum expected number of takes and do not account for mitigation 
measures. The Navy proposes the following mitigation measures to reduce 
potential impacts to marine mammals:

Mitigation Zones

    The Navy used the ZOI modeling results (discussed in Chapter 6 of 
their IHA application) to develop mitigation zones for underwater 
detonations in water >24 feet and Shock Wave Generator (SWAG) training 
events. While the ZOIs vary between the different types of underwater 
detonation training, the Navy is proposing to establish an expanded 700 
yard mitigation zone for all positive control (RFD) underwater 
detonations conducted on the oceanside of the SSTC, a 700-1,500 yard 
mitigation zone around all time-delay (TDFD) underwater detonations 
conducted on the oceanside of the SSTC, and a 60 yard mitigation zone 
around SWAG training events conducted on the oceanside and bayside of 
the SSTC. Details on how the mitigation zones were derived are provided 
in section 11 of the Navy's IHA application. These mitigation zones are 
expected to reduce or eliminate Level B harassment to marine mammals. 
The Navy also proposes a 50 yard mitigation zone during ELCAS pile 
driving and removal. In summary, the proposed mitigation zones are as 
follows for the three broad sets of training events:
    Very shallow water (<24 feet) underwater detonation--The Navy would 
use a 700 yard mitigation zone for positive control events, and 700-
1,500 yard mitigation zone for TDFD events depending on charge weight 
and delay time. The positive control mitigation zone is based on the 
maximum range of onset TTS as predicted by the iso-velocity analysis of 
empirically measured very shallow water detonations <20 lbs NEW (450-
470 yards) plus a buffer that brings the final zone to 700 yards.
    Shallow water (24 feet) underwater detonation--The Navy 
would use a 700 yard mitigation zone for positive control events, and 
700-1,500 yard mitigation zone for TDFD events depending on charge 
weight and delay time. The positive control mitigation zone is based on 
the maximum range to onset TTS predicted using the Navy's REFMS model 
(490 yards) plus a buffer that brings the final zone to 700 yards.
    ELCAS pile driving and removal--The Navy would use a 50 yard 
mitigation zone based on the maximum range estimated to the Level A 
harassment criteria for cetaceans (180 dB).

Proposed Mitigation Measures for Underwater Detonations in Very Shallow 
Water (VSW, water depth <24 ft)

Positive Control
    1. Underwater detonations using positive control (remote firing 
devices) will only be conducted during daylight.
    2. Easily visible anchored floats will be positioned on 700 yard 
radius of a roughly semi-circular zone (the

[[Page 24173]]

shoreward half being bounded by shoreline and immediate offshore water) 
around the detonation location for small explosive exercises at the 
SSTC. These mark the outer limits of the mitigation zone.
    3. For each VSW underwater detonation event, a safety-boat with a 
minimum of one observer is launched 30 or more minutes prior to 
detonation and moves through the area around the detonation site. The 
task of the safety observer is to exclude humans from coming into the 
area and to augment a shore observer's visual search of the mitigation 
zone for marine mammals. The safety-boat observer is in constant radio 
communication with the exercise coordinator and shore observer 
discussed below.
    4. A shore-based observer will also be deployed for VSW detonations 
in addition to boat based observers. The shore observer will indicate 
that the area is clear of marine mammals after 10 or more minutes of 
continuous observation with no marine mammals having been seen in the 
mitigation zone or moving toward it.
    5. At least 10 minutes prior to the planned initiation of the 
detonation event-sequence, the shore observer, on an elevated on-shore 
position, begins a continuous visual search with binoculars of the 
mitigation zone. At this time, the safety-boat observer informs the 
shore observer if any marine mammal has been seen in the zone and, 
together, both search the surface within and beyond the mitigation zone 
for marine mammals.
    6. The observers (boat and shore based) will indicate that the area 
is not clear any time a marine mammal is sighted in the mitigation zone 
or moving toward it and, subsequently, indicate that the area is clear 
of marine mammals when the animal is out and moving away and no other 
marine mammals have been sited.
    7. Initiation of the detonation sequence will only begin on final 
receipt of an indication from the shore observer that the area is clear 
of marine mammals and will be postponed on receipt of an indication 
from any observer that the area is not clear of marine mammals.
    8. Following the detonation, visual monitoring of the mitigation 
zone continues for 30 minutes for the appearance of any marine mammal 
in the zone. Any marine mammal appearing in the area will be observed 
for signs of possible injury.
    9. Any marine mammal observed after a VSW underwater detonation 
either injured or exhibiting signs of distress will be reported via 
operational chain of command to Navy environmental representatives from 
U.S. Pacific Fleet, Environmental Office, San Diego Detachment. Using 
Marine Mammal Stranding communication trees and contact procedures 
established for the Southern California Range Complex, the Navy will 
report these events to the Stranding Coordinator of NMFS' Southwest 
Regional Office. These voice or email reports will contain the date and 
time of the sighting, location (or if precise latitude and longitude is 
not currently available, then the approximate location in reference to 
an established SSTC beach feature), species description (if known), and 
indication of the animal's status.

Time-Delay Firing Devices

    1. Underwater detonations using timed delay devices would only be 
conducted during daylight.
    2. Time-delays longer than 10 minutes would not be used. The 
initiation of the device will not start until the mitigation area below 
is clear for a full 30 minutes prior to initiation of the timer.
    3. A mitigation zone would be established around each underwater 
detonation location as indicated in Table 7 (1,000, 1,400 yards, or 
1,500) based on charge weight and length of time delay used.
    4. VSW ranges 1,000 yds:
     For each VSW underwater detonation event with a mitigation 
zone of 1,000 yds, a safety boat with a minimum of one observer is 
launched 30 or more minutes prior to detonation and moves through the 
area around the detonation site at the seaward edge of the mitigation 
zone. The task of the boat is to exclude humans from coming into the 
area and to augment a shore observer's visual search of the mitigation 
zone for marine mammals. The safety-boat observer is in constant radio 
communication with the exercise coordinator and shore observer 
discussed below. To the best extent practical, boats will try to 
maintain a 10 knot search speed.
     A shore-based observer will also be deployed for VSW 
detonations in addition to boat based observers. At least 10 minutes 
prior to the planned initiation of the detonation event-sequence, the 
shore observer, on an elevated on-shore position, begins a continuous 
visual search with binoculars of the mitigation zone. At this time, the 
safety-boat observer informs the shore observer if any marine mammal 
has been seen in the zone and, together, both search the surface within 
and beyond the mitigation zone for marine mammals. The shore observer 
will indicate that the area is clear of marine mammals after 10 or more 
minutes of continuous observation with no marine mammals having been 
seen in the mitigation zone or moving toward it.
    5. VSW ranges >=1,400 yards:
     A minimum of two boats and one shore-based observer would 
be used to survey for marine mammals at mitigation ranges >=1,400 
yards.
     When conducting the surveys within a mitigation zone 
>=1,400 yds, boats will position themselves near the mid-point of the 
mitigation zone radius (but always outside the detonation plume radius/
human safety zone) and travel in a semi-circular pattern around the 
detonation location surveying both the inner (toward detonation site) 
and outer (away from detonation site) areas. When using two boats, each 
boat will be positioned on opposite sides of the detonation location, 
separated by 180 degrees. If using more than two boats, each boat will 
be positioned equidistant from one another (120 degrees separation for 
three boats, 90 degrees separation for four boats, etc.). If available, 
aerial visual survey support from Navy helicopters can be utilized, so 
long as it will not jeopardize safety of flight. Helicopters will 
travel in a circular pattern around the detonation location.
    6. A mitigation zone will be surveyed from 30 minutes prior to the 
detonation and for 30 minutes after the detonation.
    7. Other personnel besides boat observers can also maintain 
situational awareness on the presence of marine mammals within the 
mitigation zone to the best extent practical given dive safety 
considerations.
    Divers placing the charges on mines will observe the immediate 
underwater area around a detonation site for marine mammals and report 
sightings to surface observers.
    8. If a marine mammal is sighted within an established mitigation 
zone or moving towards it, underwater detonation events will be 
suspended until the marine mammal has voluntarily left the area and the 
area is clear of marine mammals for at least 30 minutes.
    9. Immediately following the detonation, visual monitoring for 
affected marine mammals within the mitigation zone will continue for 30 
minutes.
    10. Any marine mammal observed after an underwater detonation 
either injured or exhibiting signs of distress will be reported via 
Navy operational chain of command to Navy environmental representatives 
from U.S. Pacific Fleet, Environmental Office, San Diego Detachment. 
Using Marine

[[Page 24174]]

Mammal Stranding communication trees and contact procedures established 
for the Southern California Range Complex, the Navy will report these 
events to the Stranding Coordinator of NMFS' Southwest Regional Office. 
These voice or email reports will contain the date and time of the 
sighting, location (or if precise latitude and longitude is not 
currently available, then the approximate location in reference to an 
established SSTC beach feature), species description (if known), and 
indication of the animal's status.

Proposed Mitigation and Monitoring Measures for Underwater Detonations 
in Shallow Water (>24 Feet)

Positive Control (Except SWAG and Timed Detonations)
    1. Underwater detonations using positive control devices would only 
be conducted during daylight.
    2. A mitigation zone of 700 yards would be established around each 
underwater detonation point.
    3. A minimum of two boats, including but not limited to small 
zodiacs and 7-m Rigid Hulled Inflatable Boats (RHIB) would be deployed. 
One boat would act as an observer platform, while the other boat is 
typically the diver support boat.
    4. Two observers with binoculars on one small craft/boat would 
survey the detonation area and the mitigation zone for marine mammals 
from at least 30 minutes prior to commencement of the scheduled 
explosive event and until at least 30 minutes after detonation.
    5. In addition to the dedicated observers, all divers and boat 
operators engaged in detonation events can potentially monitor the area 
immediately surrounding the point of detonation for marine mammals.
    6. Explosive detonations would cease if a marine mammal is visually 
detected within the mitigation zone. Detonations may recommence if any 
of the following conditions are met: (1) The animal is observed exiting 
the mitigation zone, (2) the animal is thought to have exited the 
mitigation zone based on its course and speed, or (3) the mitigation 
zone has been clear from any additional sightings for a period of 30 
minutes.
    7. Immediately following the detonation, visual monitoring for 
marine mammals within the mitigation zone will continue for 30 minutes. 
Any marine mammal observed after an underwater detonation either 
injured or exhibiting signs of distress will be reported to via Navy 
operational chain of command to Navy environmental representatives from 
U.S. Pacific Fleet, Environmental Office, San Diego Detachment. Using 
Marine Mammal Stranding communication trees and contact procedures 
established for the Southern California Range Complex, the Navy will 
report these events to the Stranding Coordinator of NMFS' Southwest 
Regional Office. These voice or email reports will contain the date and 
time of the sighting, location (or if precise latitude and longitude is 
not currently available, then the approximate location in reference to 
an established SSTC beach feature), species description (if known), and 
indication of the animals status.

Mitigation and Monitoring Measures for Underwater Detonations Using 
Time-Delay (TDFD Detonations Only)

    1. Underwater detonations using timed delay devices would only be 
conducted during daylight.
    2. Time-delays longer than 10 minutes would not be used. The 
initiation of the device would not start until the mitigation area 
below is clear for a full 30 minutes prior to initiation of the timer.
    3. A mitigation zone would be established around each underwater 
detonation location as indicated in Table 3 based on charge weight and 
length of time-delay used. When conducting the surveys within a 
mitigation zone (either 1,000 or >=1,400 yds), boats will position 
themselves near the mid-point of the mitigation zone radius (but always 
outside the detonation plume radius/human safety zone) and travel in a 
circular pattern around the detonation location surveying both the 
inner (toward detonation site) and outer (away from detonation site) 
areas.
    4. Shallow water TDFD detonations 1,000 yds:
     A minimum of two boats would be used to survey for marine 
mammals at mitigation ranges of 1,000 yds.
     When using two boats, each boat would be positioned on 
opposite sides of the detonation location, separated by 180 degrees.
     Two observers in each of the boats will conduct continuous 
visual survey of the mitigation zone for the entire duration of a 
training event.
     To the best extent practical, boats will try to maintain a 
10 knot search speed. This search speed was added to ensure adequate 
coverage of the buffer zone during observation periods. While weather 
conditions and sea states may require slower speeds in some instances, 
10 knots is a prudent, safe, and executable speed that will allow for 
adequate surveillance. For a 1,000 yd radius buffer zone a boat 
travelling at 10 knots and 500 yds away from the detonation point would 
circle the detonation point 3.22 times during a 30 minute survey 
period. By using two boats, 6.44 circles around the detonation point 
would be completed in a 30 minute span.
    5. Shallow water TDFD detonations >=1,400 yds:
     A minimum of three boats or two boats and one helicopter 
would be used to survey for marine mammals at mitigation ranges of 
1,400 yds.
     When using three (or more) boats, each boat would be 
positioned equidistant from one another (120 degrees separation for 
three boats, 90 degrees separation for four boats, etc.).
     For a 1,400 yd radius mitigation zone, a 10 knot speed 
results in 2.3 circles for each of the three boats, or nearly 7 circles 
around the detonation point over a 30 minute span.
     If available, aerial visual survey support from Navy 
helicopters can be utilized, so long as it will not jeopardize safety 
of flight.
     Helicopters, if available, can be used in lieu of one of 
the boat requirements. Navy helicopter pilots are trained to conduct 
searches for relatively small objects in the water, such as a missing 
person. A helicopter search pattern is dictated by standard Navy 
protocols and accounts for multiple variables, such as the size and 
shape of the search area, size of the object being searched for, and 
local environmental conditions, among others.
    6. A mitigation zone would be surveyed from 30 minutes prior to the 
detonation and for 30 minutes after the detonation.
    7. Other personnel besides boat observers can also maintain 
situational awareness on the presence of marine mammals within the 
mitigation zone to the best extent practical given dive safety 
considerations.
    Divers placing the charges on mines would observe the immediate 
underwater area around a detonation site for marine mammals and report 
sightings to surface observers.
    8. If a marine mammal is sighted within an established mitigation 
zone or moving towards it, underwater detonation events will be 
suspended until the marine mammal has voluntarily left the area and the 
area is clear of marine mammals for at least 30 minutes.
    9. Immediately following the detonation, visual monitoring for 
affected marine mammals within the mitigation zone will continue for 30 
minutes.
    10. Any marine mammal observed after an underwater detonation 
either

[[Page 24175]]

injured or exhibiting signs of distress will be reported via Navy 
operational chain of command to Navy environmental representatives from 
U.S. Pacific Fleet, Environmental Office, San Diego Detachment or Pearl 
Harbor. Using Marine Mammal Stranding protocols and communication trees 
established for the Southern California and Hawaii Range Complexes, the 
Navy will report these events to the Stranding Coordinator of NMFS' 
Southwest or Pacific Islands Regional Office. These voice or email 
reports will contain the date and time of the sighting, location (or if 
precise latitude and longitude is not currently available, then the 
approximate location in reference to an established SSTC beach 
feature), species description (if known), and indication of the 
animal's status.
(3) Proposed Mitigation and Monitoring Measures for Underwater SWAG 
Detonations (SWAG Only)
    A modified set of mitigation measures would be implemented for SWAG 
detonations, which involve much smaller charges of 0.03 lbs NEW.
    1. Underwater detonations using SWAG would only be conducted during 
daylight.
    2. A mitigation zone of 60 yards would be established around each 
SWAG detonation site.
    3. A minimum of two boats, including but not limited to small 
zodiacs and 7-m Rigid Hulled Inflatable Boats (RHIB) would be deployed. 
One boat would act as an observer platform, while the other boat is 
typically the diver support boat.
    4. Two observers with binoculars on one small craft\boat would 
survey the detonation area and the mitigation zone for marine mammals 
from at least 10 minutes prior to commencement of the scheduled 
explosive event and until at least 10 minutes after detonation.
    5. In addition to the dedicated observers, all divers and boat 
operators engaged in detonation events can potentially monitor the area 
immediately surrounding the point of detonation for marine mammals.
    Divers and personnel in support boats would monitor for marine 
mammals out to the 60 yard mitigation zone for 10 minutes prior to any 
detonation.
    6. After the detonation, visual monitoring for marine mammals would 
continue for 10 minutes. Any marine mammal observed after an underwater 
detonation either injured or exhibiting signs of distress will be 
reported via Navy operational chain of command to Navy environmental 
representatives from U.S. Pacific Fleet, Environmental Office, San 
Diego Detachment. Using Marine Mammal Stranding communication trees and 
contact procedures established for the Southern California Range 
Complex, the Navy will report these events to the Stranding Coordinator 
of NMFS' Southwest Regional Office. These voice or email reports will 
contain the date and time of the sighting, location (or if precise 
latitude and longitude is not currently available, then the approximate 
location in reference to an established SSTC beach feature), species 
description (if known), and indication of the animal's status.

Proposed Mitigation for ELCAS Training

     Mitigation zone--A mitigation zone would be established at 
50 yards from ELCAS pile driving and removal events. This mitigation 
zone is based on the predicted range to Level A harassment for 
cetaceans (180 dB) and would also be applied to pinnipeds.
     Monitoring would be conducted within the 50 yard 
mitigation zone for the presence of marine mammals during ELCAS pile 
driving and removal events. Monitoring would begin 30 minutes before 
any ELCAS pile driving or removal event, continue during pile driving 
or removal events, and be conducted for 30 minutes after pile driving 
or removal ends. A minimum of one trained observer would be placed on 
shore, on the ELCAS, or in a boat at the best vantage point(s) to 
monitor for marine mammals.
     If a marine mammal is seen within the 50 yard mitigation 
zone, pile removal events would be delayed or stopped until the animal 
has voluntarily left the mitigation zone.
     The observer(s) would implement shutdown and delay 
procedures when applicable by notifying the hammer operator when a 
marine mammal is seen within the mitigation zone.
     Soft start-The Navy would implement a soft start for all 
ELCAS pile driving. The pile driver would increase impact strength as 
resistance goes up. The pile driver piston initially drops a few 
inches, but as resistance increases, the pile driver piston drops from 
a higher distance and has more impact. This would allow marine mammals 
in the proposed action area to move away from the sound source before 
the pile driver reaches full power.

Proposed Monitoring and Reporting

    In order to issue an ITA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth, where applicable, 
``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 ITAs must include the suggested means of 
accomplishing the necessary monitoring and reporting that will result 
in increased knowledge of the species and of the level of taking or 
impacts on populations of marine mammals that are expected to be 
present in the proposed action area.
    In addition to the mitigation monitoring described above, the Navy 
also proposes to monitor a subset of SSTC underwater detonation events 
to validate the Navy's pre- and post-event mitigation effectiveness, 
and observe marine mammal reaction, or lack of reaction to SSTC 
training events. The Navy also proposes to conduct an acoustic 
monitoring project during the first field deployment of the ELCAS.

Monitoring a Subset of Underwater Detonations

    Protected species observers would be placed either alongside 
existing Navy SSTC operators during a subset of training events, or on 
a separate small boat viewing platform. Use of protected species 
observers would verify Navy mitigation efforts within the SSTC, offer 
an opportunity for more detailed species identification, provide an 
opportunity to bring animal protection awareness to Navy personnel at 
the SSTC, and provide the opportunity for an experienced biologist to 
collect data on marine mammal behavior. Events selected for protected 
species observer participation would be an appropriate fit in terms of 
security, safety, logistics, and compatibility with Navy underwater 
detonation training. The Navy would attempt to monitor between 2 and 4 
percent of their annual underwater detonations (6-12 detonations). 
Protected species observers would collect the same data currently being 
collected for more elaborate offshore ship-based observations, 
including but not limited to:
     Location of sighting;
     Species;
     Number of individuals;
     Number of calves present;
     Duration of sighting;
     Behavior of marine mammals sighted;
     Direction of travel;
     Environmental information associated with sighting event, 
including Beaufort sea state, wave height, swell direction, wind 
direction, wind speed, glare, percentage of glare, percentage of cloud 
cover; and
     Whether the sighting occurred before, during, or after a 
detonation.
    Protected species observers would not be part of the Navy's formal 
reporting

[[Page 24176]]

chain of command during their data collection efforts. However, 
exceptions would be made if a marine mammal is observed within the 
proposed mitigation zone. Protected species observers would inform any 
Navy operator of the sighting so that appropriate action may be taken.

ELCAS Underwater Propagation Monitoring

    The Navy proposes to conduct an underwater acoustic propagation 
monitoring project during the first available ELCAS deployment at the 
SSTC. The acoustic monitoring would provide empirical field data on 
actual ELCAS pile driving and removal underwater source levels, and 
propagation specific to ELCAS training at the SSTC. These results would 
be used to either confirm or refine the Navy's exposure predictions.

Reporting

    In order to issue an ITA for an activity, section 101(a)(5)(A) of 
the MMPA states that NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such taking.'' Effective reporting is 
critical both to compliance as well as ensuring that the most value is 
obtained from the required monitoring.
    General Notification of Injured or Dead Marine Mammals--Navy 
personnel would ensure that NMFS (the appropriate Regional Stranding 
Coordinator) is notified immediately (or as soon as clearance 
procedures allow) if an injured or dead marine mammal is found during 
or shortly after, and in the vicinity of, any Navy training exercises 
involving underwater detonations or pile driving. The Navy shall 
provide NMFS with species or description of the animal(s), the 
conditions 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 submit a report to the Office of Protected 
Resources, NMFS, no later than 90 days after the expiration of the IHA. 
The report shall, at a minimum, include the following marine mammal 
sighting information:
     Location of sighting;
     Species;
     Number of individuals;
     Number of calves present;
     Duration of sighting;
     Behavior of marine mammals sighted;
     Direction of travel;
     Environmental information associated with each sighting 
event, including Beaufort sea state, wave height, swell direction, wind 
direction, wind speed, glare, percentage of glare, percentage of cloud 
cover; and
     Whether the sighting occurred before, during, or after a 
detonation.
    In addition, the Navy would provide information for all underwater 
detonation events and ELCAS events under the IHA. This information 
would include: total number of each type of underwater detonation 
events and total number of piles driven/extracted during ELCAS.
    The Navy would submit a draft report to NMFS, as described above, 
and would respond to NMFS comments within 3 months of receipt. The 
report would be considered final after the Navy has addressed NMFS' 
comments, or 3 months after the submittal of the draft if NMFS does not 
comment by then.

Past Monitoring and Reporting

    The Navy has complied with monitoring and reporting requirements 
under their previous IHAs for the SSTC. To date, two underwater 
demolition training events have been observed by protected species 
observers between July 2012 and November 2012. Broad scale Navy-funded 
monitoring in support of the Navy's Southern California (SOCAL) Range 
Complex Letter of Authorization has typically focused on the offshore 
waters north and west of the SSTC. The Navy obtained special flight 
permission to survey the vicinity of the SSTC during part of three 
aerial surveys under the SOCAL monitoring plan in 2011-2012. As 
anticipated, marine mammal sightings were limited and included several 
California sea lions and a few unidentified dolphins, although the 
dolphin sightings were several miles offshore from the normal SSTC 
training area.

Estimated Take by Incidental Harassment

Estimated Marine Mammal Exposures from SSTC Underwater Detonations

    The Navy's quantitative exposure modeling methodology estimated 
numbers of animals exposed to the effects of underwater detonations 
exceeding the thresholds used, as if no mitigation measures were 
employed. All estimated exposures are seasonal averages (mean) plus one 
standard deviation using half of the annual training tempo to represent 
each season. This approach results in an over-prediction of exposure to 
typical training during a single year. Table 5 shows the number of 
annual predicted exposures by species for all underwater detonation 
training within the SSTC. As stated previously, only events with 
sequential detonations were examined for non-TTS behavior disruption. 
For all underwater detonations, the Navy's impact model predicted no 
marine mammal mortality and no Level A exposure to any species.

            Table 5--The Navy's Modeled Estimates of Species Exposed to Underwater Detonations Without Implementation of Mitigation Measures
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                        Annual Marine Mammal Exposure (All Sources)
                                                                 ---------------------------------------------------------------------------------------
                                                                    Level B Behavior         Level B TTS             Level A              Mortality
                                                                  (Multiple Successive -----------------------------------------------------------------
                             Species                                Explosive Events
                                                                          Only)              182 dB re 1           205 dB re 1
                                                                 ----------------------  [mu]Pa\2\-s/23 psi   [mu]Pa\2\-s/13.0 psi-      30.5 psi-ms
                                                                   177 dB re 1 [mu]Pa                                  ms
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray Whale:
    Warm........................................................                   N/A                   N/A                   N/A                   N/A
    Cold........................................................                     0                     0                     0                     0
Bottlenose Dolphin:
    Warm........................................................                    30                    43                     0                     0
    Cold........................................................                    40                    55                     0                     0
California Sea Lion:
    Warm........................................................                     4                     4                     0                     0
    Cold........................................................                    40                    51                     0                     0
Harbor Seal:

[[Page 24177]]

 
    Warm........................................................                     0                     0                     0                     0
    Cold........................................................                     0                     0                     0                     0
Long-beaked common dolphin:
    Warm........................................................                    14                    21                     0                     0
    Cold........................................................                     7                    10                     0                     0
Pacific white-sided dolphin:
    Warm........................................................                     2                     3                     0                     0
    Cold........................................................                     3                     4                     0                     0
Risso's dolphin:
    Warm........................................................                     3                     4                     0                     0
    Cold........................................................                    11                    15                     0                     0
Short-beaked common dolphin:
    Warm........................................................                   123                   177                     0                     0
    Cold........................................................                    62                    86                     0                     0
                                                                 ---------------------------------------------------------------------------------------
        Total Annual Exposures..................................                   339                   473                     0                     0
--------------------------------------------------------------------------------------------------------------------------------------------------------

Estimated Marine Mammal Exposures From ELCAS Pile Driving and Removal

I. Pile Driving
    Using the marine mammal densities presented in the Navy's IHA 
application, the number of animals exposed to annual Level B harassment 
from ELCAS pile driving can be estimated. A couple of business rules 
and assumptions are used in this determination:
    1. Pile driving is estimated to occur 10 days per ELCAS training 
event, with up to four training exercises being conducted per year (40 
days per year). Given likely variable training schedules, an assumption 
was made that approximately 20 of these 40 days would occur during the 
warm water season, and 20 of the 40 days would occur during the cold 
water season.
    2. To be more conservative even to the point of over predicting 
likely exposures, the Navy asserts that during the calculation there 
can be no ``fractional'' exposures of marine mammals on a daily basis, 
and all exposure values are rounded up during the calculation.
    To estimate the potential ELCAS pile driving exposure, the 
following expression is used:
    Annual exposure = ZOI x warm season marine mammal density x warm 
season pile driving days + ZOI x cold season marine mammal density x 
cold season pile driving days, with ZOI = [pi] x R\2\, where R is the 
radius of the ZOI.
    An example showing the take calculation for bottlenose dolphins, 
with the conservative ``daily rounding up'' business rule (2 
above), is shown below:
    Daily exposure = [pi] x 0.999\2\ x 0.202 + [pi] x 0.999\2\ x 0.202 
= 0.6 + 0.6.
    When rounding up the daily exposure 0.6 dolphin to 1 dolphin; the 
annual exposure from warm season pile driving days (20 days) and cold 
season pile driving days (20 days) is:
    Annual exposure = 1 x 20 + 1 x 20 = 40
    Based on the assessment using the methodology discussed previously, 
applying the business rules and limitations described here, and without 
consideration of mitigation measures, the take estimate is that ELCAS 
pile driving is predicted to result in no Level A Harassment takes of 
any marine mammal (received SPL of 190 dBrms for pinnipeds 
and 180 dBrms re 1 [mu]Pa for cetacean, respectively) but 
take of 40 bottlenose dolphins, 20 California sea lions, and 80 short-
beaked common dolphins by Level B behavioral harassment (Table 5).
II. Pile Removal
    The same approach is applied for take estimation from ELCAS pile 
removal. To estimate the potential ELCAS pile removal exposure, the 
following expression is used:
    Annual exposure = ZOI x warm season marine mammal density x warm 
season pile removal days + ZOI x cold season marine mammal density x 
cold season pile removal days, with ZOI = [pi] x R\2\, where R is the 
radius of the ZOI.
    An example showing the take calculation for bottlenose dolphins, 
with the conservative ``daily rounding up'' business rule for pile 
removal, is shown below:
    Daily exposure = [pi] x 4.64\2\ x 0.202 + [pi] x 4.64\2\ x 0.202 = 
13.7 + 13.7.
    When rounding up the daily exposure 13.7 dolphins to 14 dolphins; 
the annual exposure from warm season pile removal days (6 days) and 
cold season pile removal days (6 days) is:
    Annual exposure = 14 x 6 + 14 x 6 = 168
    Based on the assessment using the methodology discussed previously, 
applying the methods and limitations described here, and without 
consideration of mitigation measures, the take estimate is that ELCAS 
pile removal is predicted to result in no Level A Harassments takes of 
any marine mammal; Level B exposures are shown in Table 6.

[[Page 24178]]



                          Table 6--Exposure Estimates From ELCAS Pile Driving and Removal Prior to Implementation of Mitigation
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                        Annual marine mammal exposure (all sources)
                                                                 ---------------------------------------------------------------------------------------
                             Species                                Level B Behavior      Level B Behavior     Level A (Cetacean)    Level A (Pinniped)
                                                                    (Non-Impulse) 120    (Impulse) 120 dBrms     120 dBrms re 1        120 dBrms re 1
                                                                    dBrms re 1 [mu]Pa        re 1 [mu]Pa             [mu]Pa                [mu]Pa
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray Whale
    Installation................................................                   N/A                     0                     0                     0
    Removal.....................................................                     6                   N/A                     0                     0
Bottlenose Dolphin
    Installation................................................                   N/A                    40                     0                     0
    Removal.....................................................                   168                   N/A                     0                     0
California Sea Lion
    Installation................................................                   N/A                    20                     0                     0
    Removal.....................................................                   102                   N/A                     0                     0
Harbor Seal
    Installation................................................                   N/A                     0                     0                     0
    Removal.....................................................                    12                   N/A                     0                     0
Long-beaked common dolphin
    Installation................................................                   N/A                     0                     0                     0
    Removal.....................................................                    54                   N/A                     0                     0
Pacific white-sided dolphin
    Installation................................................                   N/A                     0                     0                     0
    Removal.....................................................                    12                   N/A                     0                     0
Risso's dolphin
    Installation................................................                   N/A                     0                     0                     0
    Removal.....................................................                    30                   N/A                     0                     0
Short-beaked common dolphin
    Installation................................................                   N/A                    80                     0                     0
    Removal.....................................................                   462                   N/A                     0                     0
                                                                 ---------------------------------------------------------------------------------------
        Total Annual Exposures..................................                   846                   140                     0                     0
--------------------------------------------------------------------------------------------------------------------------------------------------------

    In summary, for all underwater detonations and ELCAS pile driving 
activities, the Navy's impact model predicted that no mortality and/or 
Level A harassment (injury) would occur to marine mammal species and 
stocks within the proposed action area.

Anticipated Effects on Habitat

    The proposed training activities at SSTC would not result in any 
permanent impact on habitats used by marine mammals, and potentially 
short-term to minimum impact to the food sources such as forage fish. 
There are no known haul-out sites, foraging hotspots, or other ocean 
bottom structures of significant biological importance to harbor seals, 
California sea lions, or bottlenose dolphins within SSTC. Therefore, 
the main impact associated with the proposed activity would be 
temporarily elevated noise levels and the associated direct effects on 
marine mammals, as discussed previously.
    The primary source of effects to marine mammal habitat is exposures 
resulting from underwater detonation training and ELCAS pile driving 
and removal training events. Other sources that may affect marine 
mammal habitat include changes in transiting vessels, vessel strike, 
turbidity, and introduction of fuel, debris, ordnance, and chemical 
residues. However, each of these components was addressed in the SSTC 
Environmental Impact Statement (EIS) and it is the Navy's assertion 
that there would be no likely impacts to marine mammal habitats from 
these training events.
    The most likely impact to marine mammal habitat occurs from 
underwater detonation and pile driving and removal effects on likely 
marine mammal prey (i.e., fish) within SSTC. There are currently no 
well-established thresholds for estimating effects to fish from 
explosives other than mortality models. Fish that are located in the 
water column, in proximity to the source of detonation could be 
injured, killed, or disturbed by the impulsive sound and could leave 
the area temporarily. Continental Shelf Inc. (2004) summarized a few 
studies conducted to determine effects associated with removal of 
offshore structures (e.g., oil rigs) in the Gulf of Mexico. Their 
findings revealed that at very close range, underwater explosions are 
lethal to most fish species regardless of size, shape, or internal 
anatomy. In most situations, cause of death in fish has been massive 
organ and tissue damage and internal bleeding. At longer range, species 
with gas-filled swimbladders (e.g., snapper, cod, and striped bass) are 
more susceptible than those without swimbladders (e.g., flounders, 
eels).
    Studies also suggest that larger fish are generally less 
susceptible to death or injury than small fish. Moreover, elongated 
forms that are round in cross section are less at risk than deep-bodied 
forms. Orientation of fish relative to the shock wave may also affect 
the extent of injury. Open water pelagic fish (e.g., mackerel) seem to 
be less affected than reef fishes. The results of most studies are 
dependent upon specific biological, environmental, explosive, and data 
recording factors.
    The huge variation in fish populations, including numbers, species, 
sizes, and orientation and range from the detonation point, makes it 
very difficult to accurately predict mortalities at any specific site 
of detonation. All underwater detonations are of small scale (under 29 
lbs NEW), and the proposed training exercises would be conducted in 
several areas within the large SSTC Study Area over the seasons during 
the year. Most fish species experience a large number of natural 
mortalities, especially during early life-stages, and any small level 
of mortality caused by the SSTC training exercises involving explosives 
will likely be insignificant to the population as a whole.
    Therefore, potential impacts to marine mammal food resources within 
the SSTC are expected to be minimal given both the very geographic and 
spatially

[[Page 24179]]

limited scope of most Navy at-sea activities including underwater 
detonations, and the high biological productivity of these resources. 
No short or long term effects to marine mammal food resources from Navy 
activities are anticipated within the SSTC.

Subsistence Harvest of Marine Mammals

    NMFS has preliminarily determined that the Navy's proposed training 
activities at the SSTC would not have an unmitigable adverse impact on 
the availability of the affected species or stocks for subsistence use 
since there are no such uses in the specified area.
    Negligible Impact Analysis and Determination
    Pursuant to NMFS' regulations implementing the MMPA, an applicant 
is required to estimate the number of animals that will be ``taken'' by 
the specified activities (i.e., takes by harassment only, or takes by 
harassment, injury, and/or death). This estimate informs the analysis 
that NMFS must perform to determine whether the activity will have a 
``negligible impact'' on the species or stock. Level B (behavioral) 
harassment occurs at the level of the individual(s) and does not assume 
any resulting population-level consequences, though there are known 
avenues through which behavioral disturbance of individuals can result 
in population-level effects. A negligible impact finding is based on 
the lack of likely adverse effects on annual rates of recruitment or 
survival (i.e., population-level effects). An estimate of the number of 
Level B harassment takes, alone, is not enough information on which to 
base an impact determination. In addition to considering estimates of 
the number of marine mammals that might be ``taken'' through behavioral 
harassment, NMFS must consider other factors, such as the likely nature 
of any responses (their intensity, duration, etc.), the context of any 
responses (critical reproductive time or location, migration, etc.), or 
any of the other variables mentioned in the first paragraph (if known), 
as well as the number and nature of estimated Level A takes, the number 
of estimated mortalities, and effects on habitat.
    The Navy's specified activities have been described based on best 
estimates of the planned training exercises at SSTC action area. Some 
of the noises that would be generated as a result of the proposed 
underwater detonation and ELCAS pile driving activities are high 
intensity. However, the planned explosives have relatively small zones 
of influence. The locations of the proposed training activities are 
shallow water areas, which would effectively contain the spreading of 
explosive energy within the bottom boundary. Taking the above into 
account, along with the fact that NMFS anticipates no mortalities and 
injuries to result from the action, the fact that there are no specific 
areas of reproductive importance for marine mammals recognized within 
the SSTC area, the sections discussed below, and dependent upon the 
implementation of the proposed mitigation measures, NMFS has determined 
that Navy training exercises utilizing underwater detonations and ELCAS 
pile driving and removal would have a negligible impact on the affected 
marine mammal species and stocks present in the SSTC Study Area.
    NMFS' analysis of potential behavioral harassment, temporary 
threshold shifts, permanent threshold shifts, injury, and mortality to 
marine mammals as a result of the SSTC training activities was provided 
earlier in this document and is analyzed in more detail below.

Behavioral Harassment

    As discussed earlier, the Navy's proposed SSTC training activities 
would use small underwater explosives with maximum NEW of 29 lbs with 
16 events per year in areas of small ZOIs that would mostly eliminate 
the likelihood of mortality and injury to marine mammals. In addition, 
these detonation events are widely dispersed in several designated 
sites within the SSTC Study Area. The probability that detonation 
events will overlap in time and space with marine mammals is low, 
particularly given the densities of marine mammals in the vicinity of 
SSTC Study Area and the implementation of monitoring and mitigation 
measures. Moreover, NMFS does not expect animals to experience repeat 
exposures to the same sound source as animals will likely move away 
from the source after being exposed. In addition, these isolated 
exposures, when received at distances of Level B behavioral harassment 
(i.e., 177 dB re 1 [mu]Pa\2\-s), are expected to cause brief startle 
reactions or short-term behavioral modification by the animals. These 
brief reactions and behavioral changes are expected to disappear when 
the exposures cease. Therefore, these levels of received impulse noise 
from detonation are not expected to affect annual rates or recruitment 
or survival.

TTS

    NMFS and the Navy have estimated that individuals of some species 
of marine mammals may sustain some level of temporary threshold shift 
TTS from underwater detonations. TTS can last from a few minutes to 
days, be of varying degree, and occur across various frequency 
bandwidths. The TTS sustained by an animal is primarily classified by 
three characteristics:
     Frequency--Available data (of mid-frequency hearing 
specialists exposed to mid to high frequency sounds--Southall et al. 
2007) suggest that most TTS occurs in the frequency range of the source 
up to one octave higher than the source (with the maximum TTS at \1/2\ 
octave above).
     Degree of the shift (i.e., how many dB is the sensitivity 
of the hearing reduced by)--generally, both the degree of TTS and the 
duration of TTS will be greater if the marine mammal is exposed to a 
higher level of energy (which would occur when the peak dB level is 
higher or the duration is longer). Since the impulse from detonation is 
extremely brief, an animal would have to approach very close to the 
detonation site to increase the received SEL. The threshold for the 
onset of TTS for detonations is a dual criteria: 182 dB re 1 [mu]Pa\2\-
s or 23 psi, which might be received at distances from 20-490 yards 
from the centers of detonation based on the types of NEW involved to 
receive the SEL that causes TTS compared to similar source level with 
longer durations (such as sonar signals).
     Duration of TTS (Recovery time)--Of all TTS laboratory 
studies, some using exposures of almost an hour in duration or up to 
SEL at 217 dB re 1 [mu]Pa\2\-s, almost all recovered within 1 day (or 
less, often in minutes), though in one study (Finneran et al. 2007), 
recovery took 4 days.
    Although the degree of TTS depends on the received noise levels and 
exposure time, all studies show that TTS is reversible and animals' 
sensitivity is expected to recover fully in minutes to hours based on 
the fact that the proposed underwater detonations are small in scale 
and isolated. Therefore, NMFS expects that TTS would not affect annual 
rates of recruitment or survival.

Acoustic Masking or Communication Impairment

    As discussed above, it is also possible that anthropogenic sound 
could result in masking of marine mammal communication and navigation 
signals. However, masking only occurs during the time of the signal 
(and potential secondary arrivals of indirect rays), versus TTS, which 
occurs continuously for its duration. Impulse sounds from underwater 
detonation and pile driving are brief and the majority of most

[[Page 24180]]

animals' vocalizations would not be masked. Although impulse noises 
such as those from underwater explosives and impact pile driving tend 
to decay at distance, and thus become non-impulse, give the area of 
extremely shallow water (which effectively attenuates low frequency 
sound of these impulses) and the small NEW of explosives, the SPLs at 
these distances are expected to be barely above ambient level. 
Therefore, masking effects from underwater detonation are expected to 
be minimal and unlikely. If masking or communication impairment were to 
occur briefly, it would be in the frequency ranges below 100 Hz, which 
overlaps with some mysticete vocalizations; however, it would likely 
not mask the entirety of any particular vocalization or communication 
series because of the short impulse.

PTS, Injury, or Mortality

    The modeling for take estimates predicts that no marine mammal 
would be taken by Level A harassment (injury, PTS included) or 
mortality due to the low power of the underwater detonation and the 
small ZOIs. Further, the mitigation measures have been designed to 
ensure that animals are detected in time to avoid injury or mortality 
when TDFDs are used, in consideration of swim speed.
    Additionally, as discussed previously, the take estimates do not 
account for the implementation of mitigation measures. With the 
implementation of mitigation and monitoring measures, NMFS expects that 
the takes would be reduced further. Coupled with the fact that these 
impacts would likely not occur in areas and times critical to 
reproduction, NMFS has preliminarily determined that the total taking 
incidental to the Navy's proposed SSTC training activities would have a 
negligible impact on the marine mammal species and stocks present in 
the SSTC Study Area.
    Based on the analyses of the potential impacts from the proposed 
underwater detonation training exercises conducted within the Navy's 
SSTC action area, including the consideration of TDFD use and the 
implementation of the improved marine mammal monitoring and mitigation 
measures, NMFS has preliminarily determined that the Navy's proposed 
activities within the SSTC would have a negligible impact on the marine 
mammal species and stocks, provided that mitigation and monitoring 
measures are implemented.

Endangered Species Act (ESA)

    No marine mammal species are listed as endangered or threatened 
under the ESA with confirmed or possible occurrence in the study area. 
Therefore, section 7 consultation under the ESA for NMFS's proposed 
issuance of an MMPA authorization is not warranted.

National Environmental Policy Act (NEPA)

    The Navy has prepared a Final Environmental Impact Statement (EIS) 
for the proposed SSTC training activities. The FEIS was released in 
January 2011 and it is available at https://www.silverstrandtrainingcomplexeis.com/EIS.aspx/. NMFS is a cooperating 
agency (as defined by the Council on Environmental Quality (40 CFR 
1501.6)) in the preparation of the EIS. NMFS has subsequently adopted 
the FEIS for the SSTC training activities.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to the Navy for activities at the SSTC, provided the 
previously mentioned mitigation, monitoring, and reporting requirements 
are incorporated. The proposed IHA language is provided below:
    The Commander, U.S. Pacific Fleet, 250 Makalapa Drive, Pearl 
Harbor, HI 96860-7000, and persons operating under his authority (i.e., 
Navy), are hereby authorized under section 101(a)(5)(D) of the Marine 
Mammal Protection Act (16 U.S.C. 1371 (a)(5)(D)), to harass marine 
mammals incidental to Navy training activities conducted in the Silver 
Strand Training Complex (SSTC) in California.
    1. This Incidental Harassment Authorization (IHA) is valid from 
July 18, 2012, through July 17, 2013.
    2. This IHA is valid only for training activities conducted at the 
SSTC Study Area in the vicinity of San Diego Bay, California. The 
geography location of the SSTC Study Area is located south of the City 
of Coronado, California and north of the City of Imperial Beach, 
California.
    3. General Conditions.
    (a) A copy of this IHA must be in the possession of the Commander, 
his designees, and commanding officer(s) operating under the authority 
of this IHA.
    (b) The species authorized for taking are the California sea lion 
(Zalophus californianus), Pacific Harbor seal (Phoca vitulina), 
bottlenose dolphin (Tursiops truncatus), the eastern North Pacific gray 
whale (Eschrichtius robustus), long-beaked common dolphin (Delphinus 
capensis), short-beaked common dolphin (D. delphis), Pacific white-
sided dolphin (Lagenorhynchus obliquidens), and Risso's dolphin 
(Grampus griseus).
    (c) The taking, by Level B harassment only, is limited to the 
species listed in condition 3(b).
    (d) The taking by Level A harassment, injury or death of any of the 
species listed in item 3(b) of the Authorization or the taking by 
harassment, injury or death of any other species of marine mammal is 
prohibited and may result in the modification, suspension, or 
revocation of this IHA.
    (e) In the unanticipated event that any cases of marine mammal 
injury or mortality are judged to result from these activities, the 
holder of this Authorization must immediately cease operations and 
report the incident, as soon as clearance procedures allow, to the 
Assistant Regional Administrator (ARA) for Protected Resources, NMFS 
Southwest Region, phone (562) 980-4000 and to the Chief, Permits and 
Conservation Division, Office of Protected Resources, NMFS, phone (301) 
427-8401.
    (i) The Navy shall suspend the training activities at the SSTC 
until NMFS is able to review the incident and determine whether steps 
can be taken to avoid further injury or mortality or until such taking 
can be authorized under regulations promulgated under section 
101(a)(5)(A) of the Marine Mammal Protection Act.
    4. Mitigation Measures.
    In order to ensure the least practicable impact on the species and 
levels of takes listed in 3(b) and (c), the holder of this 
Authorization is required to comply with the following mitigation 
measures:
    (a) Mitigation Measures for Underwater Detonations
    (i) Mitigation and Monitoring Measures for Underwater Detonations 
in Very Shallow Water (VSW, water depth < 24 ft)
    (1) Mitigation and Monitoring Measures for VSW Underwater 
Detonations Using Positive Control.
    A. Underwater detonations using positive control (remote firing 
devices) shall only be conducted during daylight.
    B. Easily visible anchored floats shall be positioned on 700 yard 
radius of a roughly semi-circular zone (the shoreward half being 
bounded by shoreline and immediate off-shore water) around the 
detonation location for small explosive exercises at the SSTC. These 
mark the outer limits of the mitigation zone.
    C. For each VSW underwater detonation event, a safety-boat with a 
minimum of one observer shall be launched 30 or more minutes prior to 
detonation and moves through the area around the detonation site. The 
safety-

[[Page 24181]]

boat observer shall be in constant radio communication with the 
exercise coordinator and shore observer.
    D. A shore-based observer shall also be deployed for VSW 
detonations in addition to boat based observers. The shore observer 
shall indicate that the area is clear of marine mammals after 10 or 
more minutes of continuous observation with no marine mammals having 
been seen in the mitigation zone or moving toward it.
    E. At least 10 minutes prior to the planned initiation of the 
detonation event sequence, the shore observer, on an elevated on-shore 
position, shall begin a continuous visual search with binoculars of the 
mitigation zone. At this time, the safety-boat observer shall inform 
the shore observer if any marine mammal has been seen in the zone and, 
together, both search the surface within and beyond the mitigation zone 
for marine mammals.
    F. The observers (boat and shore based) shall indicate that the 
area is not clear any time a marine mammal is sighted in the mitigation 
zone or moving toward it and, subsequently, indicate that the area is 
clear of marine mammals when the animal is out and moving away and no 
other marine mammals have been sited.
    G. Initiation of the detonation sequence shall only begin on final 
receipt of an indication from the shore observer that the area is clear 
of marine mammals and will be postponed on receipt of an indication 
from any observer that the area is not clear of marine mammals.
    H. Following the detonation, visual monitoring of the mitigation 
zone shall continue for 30 minutes for the appearance of any marine 
mammal in the zone. Any marine mammal appearing in the area shall be 
observed for signs of possible injury.
    I. Any marine mammal observed after a VSW underwater detonation 
either injured or exhibiting signs of distress shall be reported via 
operational chain of command to Navy environmental representatives from 
U.S. Pacific Fleet, Environmental Office, San Diego Detachment. Using 
Marine Mammal Stranding communication trees and contact procedures 
established for the Southern California Range Complex, the Navy shall 
report these events to the Stranding Coordinator of NMFS' Southwest 
Regional Office. These voice or email reports shall contain the date 
and time of the sighting, location (or if precise latitude and 
longitude is not currently available, then the approximate location in 
reference to an established SSTC beach feature), species description 
(if known), and indication of the animal's status.
    (2) Mitigation and Monitoring Measures for VSW Underwater 
Detonations Using Time-Delay (TDFD Only).
    A. Underwater detonations using timed delay devices will only be 
conducted during daylight.
    B. Time-delays longer than 10 minutes shall not be used. The 
initiation of the device shall not start until the mitigation area 
below is clear for a full 30 minutes prior to initiation of the timer.
    C. A mitigation zone shall be established around each underwater 
detonation location as indicated in Table below based on charge weight 
and length of time delay used.

 Table 7--Updated Buffer Zone Radius (yd) for TDFDs Based on Size of Charge and Length of Time-Delay, With Additional Buffer Added to Account for Faster
                                                                       Swim Speeds
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                       Time-delay
                              --------------------------------------------------------------------------------------------------------------------------
                                      5 min                6 min                7 min                8 min               9 min              10 min
--------------------------------------------------------------------------------------------------------------------------------------------------------
Charge Size (lb NEW)
    5 lb.....................  1,000 yd...........  1,000 yd...........  1,000 yd...........  1,000 yd..........  1,400 yd..........  1,400 yd.
    10 lb....................  1,000 yd...........  1,000 yd...........  1,000 yd...........  1,400 yd..........  1,400 yd..........  1,400 yd.
    15-29 lb.................  1,000 yd...........  1,400 yd...........  1,400 yd...........  1,400 yd..........  1,500 yd..........  1,500 yd.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    D. VSW ranges 1,000 yds:
    (A) For each VSW underwater detonation event with a mitigation zone 
of 1,000 yds, a safety boat with a minimum of one observer shall be 
launched 30 or more minutes prior to detonation and moves through the 
area around the detonation site at the seaward edge of the mitigation 
zone. The task of the boat is to exclude humans from coming into the 
area and to augment a shore observer's visual search of the mitigation 
zone for marine mammals. The safety-boat observer shall be in constant 
radio communication with the exercise coordinator and shore observer 
discussed below. To the best extent practical, boats will try to 
maintain a 10 knot search speed.
    (B) A shore-based observer shall also be deployed for VSW 
detonations in addition to boat based observers. At least 10 minutes 
prior to the planned initiation of the detonation event-sequence, the 
shore observer, on an elevated on-shore position, begins a continuous 
visual search with binoculars of the mitigation zone. The safety-boat 
observer shall inform the shore observer if any marine mammal has been 
seen in the zone and, together, both search the surface within and 
beyond the mitigation zone for marine mammals. The shore observer shall 
indicate that the area is clear of marine mammals after 10 or more 
minutes of continuous observation with no marine mammals having been 
seen in the mitigation zone or moving toward it.
    E. VSW ranges larger than 1,400 yards:
    (A) A minimum of 2 boats shall be used to survey for marine mammals 
at mitigation ranges larger than 1,400 yards.
    (B) When conducting the surveys within a mitigation zone >1,400 
yds, boats shall position themselves near the mid-point of the 
mitigation zone radius (but always outside the detonation plume radius/
human safety zone) and travel in a semi-circular pattern around the 
detonation location surveying both the inner (toward detonation site) 
and outer (away from detonation site) areas. When using 2 boats, each 
boat shall be positioned on opposite sides of the detonation location, 
separated by 180 degrees. If using more than 2 boats, each boat shall 
be positioned equidistant from one another (120 degrees separation for 
3 boats, 90 degrees separation for 4 boats, etc.). If available, aerial 
visual survey support from Navy helicopters can be utilized, so long as 
it shall not jeopardize safety of flight. Helicopters will travel in a 
circular pattern around the detonation location.
    F. A mitigation zone shall be surveyed from 30 minutes prior to the 
detonation and for 30 minutes after the detonation.
    G. Other personnel besides boat observers shall also maintain 
situational awareness on the presence of marine mammals within the 
mitigation zone to

[[Page 24182]]

the best extent practical given dive safety considerations. Divers 
placing the charges on mines shall observe the immediate underwater 
area around a detonation site for marine mammals and report sightings 
to surface observers.
    H. If a marine mammal is sighted within an established mitigation 
zone or moving towards it, underwater detonation events shall be 
suspended until the marine mammal has voluntarily left the area and the 
area is clear of marine mammals for at least 30 minutes.
    I. Immediately following the detonation, visual monitoring for 
affected marine mammals within the mitigation zone shall continue for 
30 minutes.
    J. Any marine mammal observed after an underwater detonation either 
injured or exhibiting signs of distress shall be reported via Navy 
operational chain of command to Navy environmental representatives from 
U.S. Pacific Fleet, Environmental Office, San Diego Detachment. Using 
Marine Mammal Stranding communication trees and contact procedures 
established for the Southern California Range Complex, the Navy shall 
report these events to the Stranding Coordinator of NMFS' Southwest 
Regional Office. These voice or email reports shall contain the date 
and time of the sighting, location (or if precise latitude and 
longitude is not currently available, then the approximate location in 
reference to an established SSTC beach feature), species description 
(if known), and indication of the animal's status.
    (ii) Mitigation and Monitoring Measures for Underwater Detonations 
in Shallow Water (>24 Feet)
    (1) Mitigation and Monitoring Measures for Underwater Detonations 
Using Positive Control (Except SWAG and Timed Detonations).
    A. Underwater detonations using positive control devices shall only 
be conducted during daylight.
    B. A mitigation zone of 700 yards shall be established around each 
underwater detonation point.
    C. A minimum of two boats, including but not limited to small 
zodiacs and 7-m Rigid Hulled Inflatable Boats (RHIB) shall be deployed. 
One boat shall act as an observer platform, while the other boat is 
typically the diver support boat.
    D. Two observers with binoculars on one small craft/boat shall 
survey the detonation area and the mitigation zone for marine mammals 
from at least 30 minutes prior to commencement of the scheduled 
explosive event and until at least 30 minutes after detonation.
    E. In addition to the dedicated observers, all divers and boat 
operators engaged in detonation events can potentially monitor the area 
immediately surrounding the point of detonation for marine mammals.
    F. If a marine mammal is sighted within the 700 yard mitigation 
zone or moving towards it, underwater detonation events shall be 
suspended until the marine mammal has voluntarily left the area and the 
area is clear of marine mammals for at least 30 minutes.
    G. Immediately following the detonation, visual monitoring for 
marine mammals within the mitigation zone shall continue for 30 
minutes. Any marine mammal observed after an underwater detonation 
either injured or exhibiting signs of distress shall be reported to via 
Navy operational chain of command to Navy environmental representatives 
from U.S. Pacific Fleet, Environmental Office, San Diego Detachment. 
Using Marine Mammal Stranding communication trees and contact 
procedures established for the Southern California Range Complex, the 
Navy will report these events to the Stranding Coordinator of NMFS' 
Southwest Regional Office. These voice or email reports shall contain 
the date and time of the sighting, location (or if precise latitude and 
longitude is not currently available, then the approximate location in 
reference to an established SSTC beach feature), species description 
(if known), and indication of the animals status.
    (2) Mitigation and Monitoring Measures for Underwater Detonations 
Using Time-Delay (TDFD Detonations Only)
    A. Underwater detonations using timed delay devices shall only be 
conducted during daylight.
    B. Time-delays longer than 10 minutes shall not be used. The 
initiation of the device shall not start until the mitigation area 
below is clear for a full 30 minutes prior to initiation of the timer.
    C. A mitigation zone shall be established around each underwater 
detonation location as indicated in Table above based on charge weight 
and length of time-delay used. When conducting the surveys within a 
mitigation zone (either 1,000 or 1,400 yds), boats shall position 
themselves near the mid-point of the mitigation zone radius (but always 
outside the detonation plume radius/human safety zone) and travel in a 
circular pattern around the detonation location surveying both the 
inner (toward detonation site) and outer (away from detonation site) 
areas.
    D. Shallow water TDFD detonations range 1,000 yds:
    (A) A minimum of 2 boats shall be used to survey for marine mammals 
at mitigation ranges of 1,000 yds.
    (B) When using 2 boats, each boat shall be positioned on opposite 
sides of the detonation location, separated by 180 degrees.
    (C) Two observers in each of the boats shall conduct continuous 
visual survey of the mitigation zone for the entire duration of a 
training event.
    (D) To the best extent practical, boats shall try to maintain a 10 
knot search speed. This search speed was added to ensure adequate 
coverage of the buffer zone during observation periods. While weather 
conditions and sea states may require slower speeds in some instances, 
10 knots is a prudent, safe, and executable speed that will allow for 
adequate surveillance. For a 1,000 yd radius buffer zone a boat 
travelling at 10 knots and 500 yds away from the detonation point would 
circle the detonation point 3.22 times during a 30 minute survey 
period. By using 2 boats, 6.44 circles around the detonation point 
would be completed in a 30 minute span.
    E. Shallow water TDFD detonations greater than 1,400 yds:
    (A) A minimum of 3 boats or 2 boats and 1 helicopter shall be used 
to survey for marine mammals at mitigation ranges of 1,400 yds.
    (B) When using 3 (or more) boats, each boat shall be positioned 
equidistant from one another (120 degrees separation for 3 boats, 90 
degrees separation for 4 boats, etc.).
    (C) For a 1,400 yd radius mitigation zone, a 10 knot speed results 
in 2.3 circles for each of the three boats, or nearly 7 circles around 
the detonation point over a 30 minute span.
    (D) If available, aerial visual survey support from Navy 
helicopters shall be utilized, so long as it will not jeopardize safety 
of flight.
    (E) Helicopters, if available, shall be used in lieu of one of the 
boat requirements. A helicopter search pattern is dictated by standard 
Navy protocols and accounts for multiple variables, such as the size 
and shape of the search area, size of the object being searched for, 
and local environmental conditions, among others.
    F. A mitigation zone shall be surveyed from 30 minutes prior to the 
detonation and for 30 minutes after the detonation.
    G. Other personnel besides boat observers can also maintain 
situational awareness on the presence of marine mammals within the 
mitigation zone to the best extent practical given dive safety 
considerations. Divers placing the charges on mines shall observe the 
immediate underwater area around a

[[Page 24183]]

detonation site for marine mammals and report sightings to surface 
observers.
    H. If a marine mammal is sighted within an established mitigation 
zone or moving towards it, underwater detonation events shall be 
suspended until the marine mammal has voluntarily left the area and the 
area is clear of marine mammals for at least 30 minutes.
    I. Immediately following the detonation, visual monitoring for 
affected marine mammals within the mitigation zone shall continue for 
30 minutes.
    J. Any marine mammal observed after an underwater detonation either 
injured or exhibiting signs of distress shall be reported via Navy 
operational chain of command to Navy environmental representatives from 
U.S. Pacific Fleet, Environmental Office, San Diego Detachment or Pearl 
Harbor. Using Marine Mammal Stranding protocols and communication trees 
established for the Southern California and Hawaii Range Complexes, the 
Navy shall report these events to the Stranding Coordinator of NMFS' 
Southwest or Pacific Islands Regional Office. These voice or email 
reports shall contain the date and time of the sighting, location (or 
if precise latitude and longitude is not currently available, then the 
approximate location in reference to an established SSTC beach 
feature), species description (if known), and indication of the 
animal's status.
    (3) Mitigation and Monitoring Measures for Underwater SWAG 
Detonations (SWAG Only).
    A. Underwater detonations using SWAG shall only be conducted during 
daylight.
    B. A mitigation zone of 60 yards shall be established around each 
SWAG detonation site.
    C. A minimum of two boats, including but not limited to small 
zodiacs and 7-m Rigid Hulled Inflatable Boats (RHIB) shall be deployed. 
One boat shall act as an observer platform, while the other boat is 
typically the diver support boat.
    D. Two observers with binoculars on one small craft\boat shall 
survey the detonation area and the mitigation zone for marine mammals 
from at least 10 minutes prior to commencement of the scheduled 
explosive event and until at least 10 minutes after detonation.
    E. In addition to the dedicated observers, all divers and boat 
operators engaged in detonation events shall monitor the area 
immediately surrounding the point of detonation for marine mammals when 
possible.
    F. Divers and personnel in support boats shall monitor for marine 
mammals out to the 60 yard mitigation zone for 10 minutes prior to any 
detonation.
    G. After the detonation, visual monitoring for marine mammals shall 
continue for 10 minutes. Any marine mammal observed after an underwater 
detonation either injured or exhibiting signs of distress shall be 
reported via Navy operational chain of command to Navy environmental 
representatives from U.S. Pacific Fleet, Environmental Office, San 
Diego Detachment. Using Marine Mammal Stranding communication trees and 
contact procedures established for the Southern California Range 
Complex, the Navy shall report these events to the Stranding 
Coordinator of NMFS' Southwest Regional Office. These voice or email 
reports shall contain the date and time of the sighting, location (or 
if precise latitude and longitude is not currently available, then the 
approximate location in reference to an established SSTC beach 
feature), species description (if known), and indication of the 
animal's status.
    (a) Mitigation for ELCAS Training at SSTC
    (1) Safety Zone: A safety zone shall be established at 150 feet (50 
yards) from ELCAS pile driving or removal events. This safety zone is 
base on the predicted range to Level A harassment (180 
dBrms) for cetaceans during pile driving, and is being 
applied conservatively to both cetaceans and pinnipeds during pile 
driving and removal.
    (2) If marine mammals are found within the 150-foot (50-yard) 
safety zone, pile driving or removal events shall be halted until the 
marine mammals have voluntarily left the mitigation zone.
    (3) Monitoring for marine mammals shall be conducted within the 
zone of influence and take place at 30 minutes before, during, and 30 
minutes after pile driving and removal activities, including ramp-up 
periods. A minimum of one trained observer shall be placed on shore, on 
the ELCAS, or in a boat at the best vantage point(s) practicable to 
monitor for marine mammals.
    (4) Monitoring observer(s) shall implement shut-down/delay 
procedures by calling for shut-down to the hammer operator when marine 
mammals are sighted within the safety zone. After a shut-down/delay, 
pile driving or removal shall not be resumed until the marine mammal 
within the safety zone is confirmed to have left the area or 30 minutes 
have passed without seeing the animal.
    (5) Soft Start--ELCAS pile driving shall implement a soft start as 
part of normal construction procedures. The pile driver increases 
impact strength as resistance goes up. At first, the pile driver piston 
drops a few inches. As resistance goes up, the pile driver piston will 
drop from a higher distance thus providing more impact due to gravity. 
This will allow marine mammals in the project area to vacate or begin 
vacating the area minimizing potential harassment.
    (6) Emergency Shut-down Related to Marine Mammal Injury and 
Mortality--If there is clear evidence that a marine mammal is injured 
or killed as a result of the proposed Navy training activities (e.g., 
instances in which it is clear that munitions explosions caused the 
injury or death), the Naval activities shall be immediately suspended 
and the situation immediately reported by personnel involved in the 
activity to the officer in charge of the training, who will follow Navy 
procedures for reporting the incident to NMFS through the Navy's chain-
of-command.
    1. Monitoring Measures
    In order to ensure the least practicable impact on the species and 
levels of takes listed in 3(b) and (c), the holder of this 
Authorization is required to comply with the following monitoring 
measures:
    (i) Marine Mammal Observer at a Sub-set of SSTC Underwater 
Detonation:
    (1) Civilian scientists acting as protected species observers 
(PSOs) shall be used to observe a sub-set of the SSTC underwater 
detonation events. The PSOs shall validate the suite of SSTC specific 
mitigation measures applicable to a sub-set of SSTC training events and 
to observe marine mammal behavior in the vicinity of SSTC training 
events.
    (2) PSOs shall be field-experienced observers that are either Navy 
biologists or contracted marine biologists. These civilian PSOs shall 
be placed either alongside existing Navy SSTC operators during a sub-
set of training events, or on a separate small boat viewing platform.
    (3) PSOs shall collect the same data currently being collected for 
more elaborate offshore ship-based observations including but not 
limited to:
    A. location of sighting;
    B. species;
    C. number of individuals;
    D. number of calves present;
    E. duration of sighting;
    F. behavior of marine animals sighted;
    G. direction of travel;
    H. environmental information associated with sighting event 
including Beaufort sea state, wave height, swell direction, wind 
direction, wind speed, glare, percentage of glare, percentage of cloud 
cover; and
    I. when in relation to Navy training did the sighting occur 
[before, during or after the detonation(s)].

[[Page 24184]]

    (1) The PSOs will not be part of the Navy's formal reporting chain 
of command during their data collection efforts. Exceptions can be made 
if a marine mammal is observed by the PSO within the SSTC specific 
mitigation zones the Navy has formally proposed to the NMFS. The PSO 
shall inform any Navy operator of the sighting so that appropriate 
action may be taken by the Navy trainees.
    (i) ELCAS Visual Monitoring: The Navy shall place monitoring 
personnel to note any observations during the entire pile driving 
sequence, including ``soft start'' period, for later analysis. 
Information regarding species observed during pile driving and removal 
events (including soft start period) shall include:
    (1) location of sighting;
    (2) species;
    (3) number of individuals;
    (4) number of calves present;
    (5) duration of sighting;
    (6) behavior of marine animals sighted;
    (7) direction of travel;
    (8) environmental information associated with sighting event 
including Beaufort sea state, wave height, swell direction, wind 
direction, wind speed, glare, percentage of glare, percentage of cloud 
cover; and
    (9) when in relation to Navy training did the sighting occur 
(before, during or after pile driving or removal).
    (i) ELCAS Acoustic Monitoring: The Navy shall conduct underwater 
acoustic propagation monitoring during the first available ELCAS 
deployment at the SSTC. These acoustic monitoring results shall be used 
to either confirm or refine the Navy's zones of safety and influence 
for pile driving and removal listed in 4(b)(1).
1. Reporting Measures
    (i) The Navy shall report results obtained annually from the 
Southern California Range Complex Monitoring Plan for areas pertinent 
to the SSTC, if applicable.
    (ii) The Navy shall submit a report to the Office of Protected 
Resources, NMFS, no later than 90 days after the expiration of the IHA. 
The report shall, at a minimum, includes the following marine mammal 
sighting information:
    (1) location of sighting;
    (2) species;
    (3) number of individuals;
    (4) number of calves present;
    (5) duration of sighting;
    (6) behavior of marine animals sighted;
    (7) direction of travel;
    (8) environmental information associated with sighting event 
including Beaufort sea state, wave height, swell direction, wind 
direction, wind speed, glare, percentage of glare, percentage of cloud 
cover; and
    (9) when in relation to Navy training did the sighting occur 
[before, during or after the detonation(s)].
    (i) In addition, the Navy shall provide the information for all of 
its underwater detonation events and ELCAS events under the IHA. The 
information shall include: (1) Total number of each type of underwater 
detonation events conducted at the SSTC, and (2) total number of piles 
driven and extracted during the ELCAS exercise.
    (ii) The Navy shall submit to NMFS a draft report as described 
above and shall respond to NMFS comments within 3 months of receipt. 
The report will be considered final after the Navy has addressed NMFS' 
comments, or 3 months after the submittal of the draft if NMFS does not 
comment by then.
    1. This Authorization may be modified, suspended or withdrawn if 
the holder 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.

    Dated: April 18, 2013.
Helen M. Golde,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2013-09618 Filed 4-23-13; 8:45 am]
BILLING CODE 3510-22-P