[Federal Register Volume 77, Number 106 (Friday, June 1, 2012)]
[Notices]
[Pages 32573-32591]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-13327]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XC031


Takes of Marine Mammals Incidental to Specified Activities; 
Construction and Race Event Activities for the 34th America's Cup in 
San Francisco Bay, CA

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 an application from the America's Cup Event 
Authority (ACEA) and the Port of San Francisco (Port) for an Incidental 
Harassment Authorization (IHA) to take marine mammals incidental to 
activities associated with the 34th America's Cup. Pursuant to the 
Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its 
proposal to issue an IHA to ACEA and the Port to take, by Level B 
harassment only, several species of marine mammals during the specified 
activity.

DATES: Comments and information must be received no later than July 2, 
2012.

ADDRESSES: Comments on the application should be addressed to Tammy 
Adams, Acting Chief, Permits and Conservation Division, Office of

[[Page 32574]]

Protected Resources, National Marine Fisheries Service, 1315 East-West 
Highway, Silver Spring, MD 20910. The mailbox address for providing 
email comments is [email protected]. 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. All Personal Identifying Information (e.g., name, address) 
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 containing a list of the references used 
in this document may be obtained by writing to the address specified 
above, telephoning the contact listed below (see FOR FURTHER 
INFORMATION CONTACT), or visiting the internet at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm. Supplemental documents may 
be found at the same web address. Documents cited in this notice may 
also be viewed, by appointment only, at the aforementioned physical 
address.

FOR FURTHER INFORMATION CONTACT: Ben Laws, 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 to allow, upon request, the 
incidental, but not intentional, taking of small numbers of marine 
mammals by U.S. citizens who engage in a specified activity (other than 
commercial fishing) within a specified geographical region if certain 
findings are made and either regulations are issued or, if the taking 
is limited to harassment, a notice of a proposed authorization is 
published in the Federal Register to provide public notice and initiate 
a 30-day comment period.
    Authorization for incidental taking shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth. NMFS has defined `negligible impact' in 50 CFR 216.103 
as ``* * * an impact resulting from the specified activity that cannot 
be reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.''
    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 Level B 
harassment as defined below. 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. 
If authorized, an IHA may be effective for a maximum of one year from 
date of issuance.
    Except with respect to certain activities not pertinent here, the 
MMPA defines `harassment' as: ``any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild [Level A harassment]; or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering [Level B harassment].''

Summary of Request

    NMFS received an application on January 20, 2012, from ACEA and the 
Port requesting issuance of an IHA for the taking, by Level B 
harassment only, of marine mammals incidental to activities conducted 
in support of the 34th America's Cup (AC34) in San Francisco, 
California. Following revisions requested by NMFS, the applicants 
submitted an adequate and complete application on April 27, 2012. A 
series of yacht races will be held in San Francisco Bay during 2012-13. 
The proposed activities include the installation of temporary dock 
facilities along with certain permanent improvements at the proposed 
venue sites to accommodate the AC34 events; these activities would 
require pile driving and would be conducted in advance of AC34 events. 
Components of the AC34 race events that may result in harassment of 
marine mammals include helicopter operations and fireworks displays. 
Authorization of incidental take has been requested for the harbor seal 
(Phoca vitulina), California sea lion (Zalophus californianus), harbor 
porpoise (Phocoena phocoena), and elephant seal (Mirounga 
angustirostris). Based on the best available information, the 
applicants are requesting authorization to incidentally harass up to 
14,063 California sea lions, 686 harbor seals, 63 harbor porpoises, and 
two northern elephant seals during the 1-year time span of the proposed 
IHA. The proposed IHA would be valid for one year from the date of 
issuance. Any activities that may result in incidental harassment of 
marine mammals that fall outside of the 1-year period of validity would 
require subsequent authorization.

Description of the Specified Activity

    The America's Cup is a series of match races between two yachts. 
One yacht, known as the defender, represents the yacht club that 
currently holds the America's Cup trophy while the second yacht, known 
as the challenger, represents the yacht club that is challenging for 
the cup. AC34, to be held in San Francisco Bay (the Bay), consists of 
three main stages: The America's Cup World Series; the America's Cup 
Challenger Selection Series (CCS; also referred to as the Louis Vuitton 
Cup), and the America's Cup Finals. The America's Cup World Series is a 
regular circuit of regattas (held in venues around the world) which 
allows the teams to prepare for the CCS. Regattas in the Bay will be 
held in August and October 2012. Subsequently, a challenger must win 
the CCS to earn the right to race the defender in the AC34 finals. The 
challenger series and the finals will be held in the Bay in September 
2013.
    A number of project sites, or venues, are planned to accommodate 
these events. These venues would provide all aspects of AC34 facilities 
and services, including team bases and operations, support space, media 
operations, hospitality services, sponsored commercial space, and 
entertainment and spectator venues. Construction of these venues would 
require pile driving for the installation of temporary floating docks 
as well as for permanent improvements to existing waterfront 
facilities. Helicopters would be used for AC34 2012 and 2013 races to 
serve broadcasting and media operations. Commercial-grade fireworks 
displays are proposed at the opening and closing ceremonies for the 
2013 America's Cup events only.

Region of Activity

    The proposed activity would occur in San Francisco Bay and at 
multiple locations along the San Francisco waterfront between Pier 80 
and Aquatic Cove. The actual race area is within the Western Central 
San Francisco Bay, flanked by the Golden Gate, Angel Island, the North 
Shore of San

[[Page 32575]]

Francisco, and south to Treasure Island and the San Francisco-Oakland 
Bay Bridge (SFOBB). Figures 1-2 of the application provide a vicinity 
map and show the locations where construction activities would occur 
along the San Francisco waterfront and the designated race area where 
racing events will occur within the Bay. San Francisco Bay and the 
adjacent Sacramento-San Joaquin Delta make up a large, complex, and 
highly dynamic estuary, one of the largest estuarine systems on the 
continent. The area where the proposed activities would occur is a 
heavily urbanized area with substantial industrial activity.
    Circulation within the Bay is dependent upon tides, river flow, 
winds, and bathymetry; the Bay also receives inputs from stormwater 
runoff and wastewater from municipal and industrial sources that vary 
depending on the location and seasonal weather patterns. Project 
activities are located within what is described as the Central Bay, 
which is influenced by these hydrodynamic conditions. Current and wave 
patterns exhibited along the San Francisco waterfront and within the 
Central Bay are largely generated by the tides interacting with bottom 
and shoreline configurations. The area where construction and races 
will occur is saline and dominated by ocean influences. However, during 
periods of significant runoff, especially from the Sacramento-San 
Joaquin River system, substantial freshwater migrates through San Pablo 
Bay and into San Francisco Bay. This inundation of freshwater can 
temporarily reduce the salinity of waters in the project vicinity to 
substantially less than ocean water (Bay Institute, 2003).
    Intertidal habitats in the Central Bay, or those that lie between 
low and high tides, include sandy beaches, natural and artificial rock 
(riprap), concrete bulkheads, concrete, composite and wood pier 
pilings, and mud flats. The Central Bay's proximity to the Golden Gate 
and Pacific Ocean has resulted in an intertidal zone inhabited by many 
coastal as well as estuarine species. Pilings, riprap, and pipelines 
are a dominant feature along the San Francisco waterfront. In subtidal 
areas, the Central Bay contains both soft sediment and hard substrate 
habitat. Soft bottom substrate ranges between soft mud with high silt 
and clay content and areas of coarser sand. The predominant seafloor 
habitat in the project area is unconsolidated soft sediment composed of 
combinations of mud/silt/clay, sand, and pebble/cobble, with varying 
amounts of intermixed shell fragments. Exposure to wave and current 
action, temperature, salinity, and light penetration determine the 
composition and distribution of organisms within these soft sediments 
(NOAA, 2007).
    Various contaminants are transported into San Francisco Bay by an 
assortment of sources: urban uses, industrial outfalls, municipal 
wastewater outfalls, municipal stormwater, upstream farming, upstream 
historic and current mining discharges, legacy pollutants, and various 
other pollutant sources. Contaminants are introduced into the Central 
Bay primarily through runoff, combined sewer overflow, stormwater, 
spills and leaks, and remobilization from sediment into the overlying 
water column. The San Francisco Regional Water Quality Control Board 
listed the Central Bay as an impaired water body. Under Section 303(d) 
of the Clean Water Act, impaired waters are defined as those that do 
not meet water quality standards, even after point and non-point 
sources of pollution have had pollution control technologies 
implemented. The pollutants listed for the Central Bay include 
chlordane, dichlorodiphenyltrichloroethane (DDT), dieldrin, dioxin 
compounds, exotic species, furan compounds, mercury, polychlorinated 
biphenyls (PCBs), and selenium (Bay Institute, 2003). Pollutant 
concentrations vary seasonally and annually, dependent upon their 
specific source and degradation characteristics. Contaminants, such as 
ammonia, copper, and legacy pesticides, have decreased over recent 
years due to cleanup efforts and natural attenuation (SFEI, 2010; Bay 
Institute, 2003). Noise from urban and industrial activity may be 
considered an additional pollutant in the Bay; underwater ambient sound 
levels have been measured at 133 dB rms in the nearby Oakland Outer 
Harbor.

Pile Driving

    Temporary floating docks would be installed utilizing 18-in (457-
mm) steel pipe piles; all piles for floating docks would be installed 
via vibratory pile driver only. Floating docks would be located at 
Piers 80, 30-32, 14 North, 9, 23 North and South, 27 South, 29 and 
adjacent to Marina Green (please see Figure 1 of the AC34 application 
for location overview and Figures 3-9 for detailed location diagrams). 
The floating docks would be installed at various stages starting in 
2012 and extending through the spring of 2013. Floating docks would be 
made of concrete, aluminum, or lighter-duty timber pre-cast sections 
with maximum widths of 8-16 ft (2.4-4.9 m). The dock system modules 
would be fabricated offsite and towed to specific locations via 
material barges. The sections would then be assembled and located, and 
guide piles driven to fix the dock system in place. A total of 244 18-
in steel pipe piles would be installed for temporary floating docks; 
project engineers estimate that a maximum of eight piles may be 
installed per day. Accounting for unforeseen delays, installation of 
floating docks is expected to require approximately 2 weeks at each 
location (with varying amounts of actual pile driving days), although 
the time may vary depending on number of piles to be driven and any 
unforeseen difficulties.
    In addition, repairs and improvements are proposed for Pier 19 (see 
Figure 8 of the application for a site plan). Pier 19 repairs would 
require driving of 224 12-in (305-mm) wood piles; these would be 
installed via impact hammer with an estimated maximum production rate 
of eight piles per day. Pier 19 repairs are expected to require 
approximately 28 days over the course of 4 months. Table 1 details the 
extent and location of pile driving activity.

------------------------------------------------------------------------
                                                               Number of
                           Location                              piles
------------------------------------------------------------------------
Pier 80......................................................         26
Pier 32 South................................................         27
Pier 14 North................................................         44
Pier 9.......................................................         15
Pier 23 North................................................         21
Pier 23 South................................................         16
Pier 27......................................................         55
Pier 29 East.................................................          5
Pier 29 North................................................         21
Marina Green offshore........................................         14
                                                              ----------
  Total piles for vibratory installation.....................        244
                                                              ----------
Pier 19 *....................................................        224
------------------------------------------------------------------------
* Pier 19 repairs would require impact driving of 12-in wood piles. All
  other piles would be 18-in steel piles installed with vibratory
  driver.

    Depending on the location and logistics, piles would likely be 
installed from existing deck structures using land-based pile driving 
equipment or from a barge. Impact pile driving would not occur 
concurrently with any other known project using an impact hammer; 
however, there would be no restriction on concurrent vibratory driving. 
Vibratory pile driving for installation of floating docks is planned 
for July through August 2012 and approximately March through June of 
2013, while installation of 12-inch wood piles at Pier 19 is planned 
for sometime between July and December 2012.

[[Page 32576]]

Race Events

    Two World Series events will occur in the Bay in August and October 
of 2012. Each event will run up to 9 days with 4 race days for each 
series. There will be multiple races per day. The World Series races 
will be followed in 2013 by the CCS to determine which of the 
challenger teams advances to compete with the defender in the final. 
The overall timeframe for the CCS races will occur over an 
approximately 81-day duration between July to early September of 2013 
with approximately 44 days of racing. The final races would occur in 
mid-September over an approximately 2-week period.
    The racing yachts will be launched from either Pier 80 or Piers 30-
32 Team Base locations. The yachts do not have engines; therefore, they 
will either be sailed or be towed to and from their launch area and the 
race area. During racing, yachts are required under the rules to remain 
within the race area. Each race is scheduled to last under an hour. 
These racing yachts are highly engineered in their design and 
production and have been specifically designed to be very maneuverable 
at both high and low speeds. Due to the efficient design of the hulls 
the yachts are very quiet and leave almost no wake.
    Personal watercraft or rigid inflatable boats will be used for 
umpiring the races. Two umpires will follow the racing yachts and 
remain within the course limits during the race. They will launch from 
either Marina Green or Pier 80 and power to the race course. As 
proposed by the project sponsors, the Course Marshal would establish a 
race course for each racing day within the conditions and parameters 
established under the U.S. Coast Guard's (USCG) Special Local 
Regulations (SLR), final environmental analysis documents, and various 
regulatory approvals and permits. Attendants would be at the starting 
line and each turning mark, and umpires and several support boats would 
be out on the course. All race management personnel are tasked with 
scanning for debris or other obstructions that could possibly damage or 
impede fair play. Although unlikely, in the event that a large marine 
mammal (i.e., a whale) is observed, the Course Marshal would postpone 
or abandon the race depending on the direction the whale is moving or 
its presence within or near the race course. These actions would be 
taken to ensure the safety of the marine mammal as well as the racing 
boats and crews.
    San Francisco Bay is host to regular and frequent sailing regattas, 
and there are no known records of boat strikes by race boats. Marine 
mammals present in the Bay typically avoid boats that are underway and 
that are traveling at high speeds. The high speed ferries that frequent 
Bay waters, which are predominantly multi-hull boats like the planned 
AC34 race boats, travel at speeds in excess of 20 kn and regularly 
transit across the western part of the Central Bay (where AC34 races 
are proposed to occur at speeds of up to 36 kn). These vessels have not 
been reported to be involved in any known marine mammal strikes.
    Spectator vessels would likely be moving at much slower speeds 
(under 10 kn) while congregated in the western part of the Central Bay 
to observe the races. USCG regulations are explicit that the operator 
(captain) of a vessel is responsible for the safe operation of that 
vessel at all times. A Water and Air Traffic Plan will be created for 
AC34 events, which will provide Information for Visiting Mariners to 
Reduce Impacts on Bay Habitats and Taxa (``Notice to Boaters''). The 
Notice to Boaters will be distributed to the public and will encourage 
methods for boaters to avoid any harassment (including collisions) with 
marine mammals. A comprehensive dissemination plan will coordinate 
distribution of the Water and Air Traffic Plan to multiple marinas and 
yacht clubs in California and spectator vessels entering the Bay. No 
incidental harassment of marine mammals is anticipated as a result of 
race activities.

Helicopter Operations

    Helicopters would be used for AC34 2012 and 2013 races to serve 
broadcasting and media operations. The helicopters following each race 
would fly between 100 and 400 feet above sea level (asl; 30-122 m) 
within the race area. The helicopters would normally perform coverage 
operations for up to 3 hours on a tank of fuel and would likely require 
refueling once per day. The coordination of the helicopters during race 
events would be such that one or two would stay above 400 ft asl and 
other helicopters would fly between 100-400 ft asl to more closely 
cover the racing action. The helicopters would be choreographed and 
move around the racecourse to anticipate the next important stage of 
each race for filming. To protect sensitive avian species, the project 
sponsors would restrict helicopter operations such that they would 
avoid the air space within at least 1,000 ft (vertically and 
horizontally; 305 m) around Alcatraz Island and Crissy Beach Wildlife 
Protection Area; these measures would also mitigate any possibility of 
incidental harassment of marine mammals at these locations. During 
flight operations, helicopters would minimize impacts to pinnipeds at 
Pier 39 by avoiding low flying (less than 100 ft asl). Final details of 
helicopter operations would be provided in the Water and Air Traffic 
Plan that would be developed and implemented for AC34.

Fireworks Displays

    Commercial grade fireworks displays are planned at the opening and 
closing ceremonies for the 2013 AC events only; therefore, it is likely 
that no fireworks events would occur during the 1-year period of 
validity for this proposed IHA. However, this potentially harassment-
inducing activity is precautionarily considered here to provide the 
event organizers with flexibility in scheduling such events. The 
location of the fireworks barge would be near Piers 27-29 and up to 
four fireworks displays would occur lasting 30-45 minutes each. It is 
anticipated that aerial shells would be launched from tubes (called 
mortars), using black powder charges, to altitudes of 200 to 1,000 ft 
(61-305 m) where they would explode and ignite internal burst charges 
and incendiary chemicals. Most of the incendiary elements and shell 
casings burn up in the atmosphere; however, portions of the casings and 
some internal structural components and chemical residue fall back to 
the ground or water, depending on prevailing winds.
    The project sponsors have coordinated and would continue to 
coordinate with the USCG regarding limitations on the location, 
frequency and duration of the fireworks to minimize potential 
environmental impacts. Any proposed fireworks displays would be subject 
to approval by the USCG through the USCG Marine Event Permit process.

Description of Sound Sources

    Sound travels in waves, the basic components of which are 
frequency, wavelength, velocity, and amplitude. Frequency is the number 
of pressure waves that pass by a reference point per unit of time and 
is measured in Hz or cycles per second. Wavelength is the distance 
between two peaks of a sound wave; lower frequency sounds have longer 
wavelengths than higher frequency sounds and attenuate more rapidly in 
shallower water. Amplitude is the height of the sound pressure wave or 
the ``loudness'' of a sound and is typically measured using the decibel 
(dB) scale. A dB is the ratio between a measured pressure (with sound) 
and a reference pressure (sound at a constant pressure, established by 
scientific standards). It is a logarithmic unit that

[[Page 32577]]

accounts for large variations in amplitude; therefore, relatively small 
changes in dB ratings correspond to large changes in sound pressure. 
When referring to sound pressure levels (SPLs; the sound force per unit 
area), sound is referenced in the context of underwater sound pressure 
to 1 microPascal ([mu]Pa). One pascal is the pressure resulting from a 
force of one newton exerted over an area of one square meter. The 
source level represents the sound level at a distance of 1 m from the 
source (referenced to 1 [mu]Pa). The received level is the sound level 
at the listener's position.
    Root mean square (rms) is the quadratic mean sound pressure over 
the duration of an impulse. Rms is calculated by squaring all of the 
sound amplitudes, averaging the squares, and then taking the square 
root of the average (Urick, 1975). Rms accounts for both positive and 
negative values; squaring the pressures makes all values positive so 
that they may be accounted for in the summation of pressure levels 
(Hastings and Popper, 2005). This measurement is often used in the 
context of discussing behavioral effects, in part because behavioral 
effects, which often result from auditory cues, may be better expressed 
through averaged units than by peak pressures.
    When underwater objects vibrate or activity occurs, sound-pressure 
waves are created. These waves alternately compress and decompress the 
water as the sound wave travels. Underwater sound waves radiate in all 
directions away from the source (similar to ripples on the surface of a 
pond), except in cases where the source is directional. The 
compressions and decompressions associated with sound waves are 
detected as changes in pressure by aquatic life and man-made sound 
receptors such as hydrophones. Underwater sound levels (``ambient 
sound'') are comprised of multiple sources, including physical (e.g., 
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds 
produced by marine mammals, fish, and invertebrates), and anthropogenic 
sound (e.g., vessels, dredging, aircraft, construction). Even in the 
absence of anthropogenic sound, the sea is typically a loud 
environment. A number of sources of sound are likely to occur within 
San Francisco Bay, including the following (Richardson et al., 1995):
     Wind and waves: The complex interactions between wind and 
water surface, including processes such as breaking waves and wave-
induced bubble oscillations and cavitation, are a main source of 
naturally occurring ambient noise for frequencies between 200 Hz and 50 
kHz (Mitson, 1995). In general, ambient noise levels tend to increase 
with increasing wind speed and wave height. Surf noise becomes 
important near shore, with measurements collected at a distance of 8.5 
km (5.3 mi) from shore showing an increase of 10 dB in the 100 to 700 
Hz band during heavy surf conditions.
     Precipitation noise: Noise from rain and hail impacting 
the water surface can become an important component of total noise at 
frequencies above 500 Hz, and possibly down to 100 Hz during quiet 
times.
     Biological noise: Marine mammals can contribute 
significantly to ambient noise levels, as can some fish and shrimp. The 
frequency band for biological contributions is from approximately 12 Hz 
to over 100 kHz.
     Anthropogenic noise: Sources of ambient noise related to 
human activity include transportation (surface vessels and aircraft), 
dredging and construction, oil and gas drilling and production, seismic 
surveys, sonar, explosions, and ocean acoustic studies (Richardson et 
al., 1995). Shipping noise typically dominates the total ambient noise 
for frequencies between 20 and 300 Hz. In general, the frequencies of 
anthropogenic sounds are below 1 kHz and, if higher frequency sound 
levels are created, they would attenuate (decrease) rapidly (Richardson 
et al., 1995).
    In-water construction activities associated with the project would 
include impact and vibratory pile driving. The sounds produced by these 
activities fall into one of two sound types: Pulsed and non-pulsed 
(defined in next paragraph). The distinction between these two general 
sound types is important because they have differing potential to cause 
physical effects, particularly with regard to hearing (e.g., Ward, 1997 
in Southall et al., 2007). Please see Southall et al., (2007) for an 
in-depth discussion of these concepts.
    Pulsed sounds (e.g., explosions, gunshots, sonic booms, and impact 
pile driving) are brief, broadband, atonal transients (ANSI, 1986; 
Harris, 1998) and occur either as isolated events or repeated in some 
succession. Pulsed sounds are all characterized by a relatively rapid 
rise from ambient pressure to a maximal pressure value followed by a 
decay period that may include a period of diminishing, oscillating 
maximal and minimal pressures. Pulsed sounds generally have an 
increased capacity to induce physical injury as compared with sounds 
that lack these features.
    Non-pulse (intermittent or continuous sounds) can be tonal, 
broadband, or both. Some of these non-pulse sounds can be transient 
signals of short duration but without the essential properties of 
pulses (e.g., rapid rise time). Examples of non-pulse sounds include 
those produced by vessels, aircraft, machinery operations such as 
drilling or dredging, vibratory pile driving, and active sonar systems. 
The duration of such sounds, as received at a distance, can be greatly 
extended in a highly reverberant environment.
    Impact hammers operate by repeatedly dropping a heavy piston onto a 
pile to drive the pile into the substrate. Sound generated by impact 
hammers is characterized by rapid rise times and high peak levels, a 
potentially injurious combination (Hastings and Popper, 2005). 
Vibratory hammers install piles by vibrating them and allowing the 
weight of the hammer to push them into the sediment. Vibratory hammers 
produce significantly less sound than impact hammers. Peak SPLs may be 
180 dB or greater, but are generally 10 to 20 dB lower than SPLs 
generated during impact pile driving of the same-sized pile (Caltrans, 
2009). Rise time is slower, reducing the probability and severity of 
injury (USFWS, 2009), and sound energy is distributed over a greater 
amount of time (Nedwell and Edwards, 2002; Carlson et al., 2001).

Ambient Sound

    The underwater acoustic environment consists of ambient sound, 
defined as environmental background sound levels lacking a single 
source or point (Richardson et al., 1995). The ambient underwater sound 
level of a region is defined by the total acoustical energy being 
generated by known and unknown sources, including sounds from both 
natural and anthropogenic sources. The sum of the various natural and 
anthropogenic sound sources at any given location and time depends not 
only on the source levels (as determined by current weather conditions 
and levels of biological and industrial or other anthropogenic 
activity) but also on the ability of sound to propagate through the 
environment. In turn, sound propagation is dependent on the spatially 
and temporally varying properties of the water column and sea floor, 
and is frequency-dependent. As a result of the dependence on a large 
number of varying factors, the ambient sound levels at a given 
frequency and location can vary by 10-20 dB from day to day (Richardson 
et al., 1995). In San Francisco Bay, the average broadband ambient 
underwater sound levels were measured at 133 dB re 1[mu]Pa in the 
Oakland Outer Harbor (Strategic Environmental Consulting, Inc., 2004).

[[Page 32578]]

Sound Attenuation Devices

    Sound levels can be greatly reduced during impact pile driving 
using sound attenuation devices. There are several types of sound 
attenuation devices including bubble curtains, cofferdams, and 
isolation casings (also called temporary noise attenuation piles 
[TNAP]), and cushion blocks. Cushion blocks, which are commonly used 
attenuation devices for timber piles, consist of materials (e.g., wood, 
nylon) placed atop piles during impact pile driving activities to 
reduce source levels. Typically sound reduction performance is 
variable, but can range from 4 to a maximum of 26 dB. Both 
environmental conditions and the characteristics of the sound 
attenuation device may influence the effectiveness of the device.

Sound Thresholds

    Since 1997, NMFS has used generic sound exposure thresholds to 
determine when an activity in the ocean that produces sound might 
result in impacts to a marine mammal such that a take by harassment 
might occur (NMFS, 2005). To date, no studies have been conducted that 
examine impacts to marine mammals from pile driving sounds from which 
empirical sound thresholds have been established. Current NMFS practice 
regarding exposure of marine mammals to sound is that cetaceans and 
pinnipeds exposed to impulsive sounds of 180 and 190 dB rms or above, 
respectively, are considered to have been taken by Level A (i.e., 
injurious) harassment. Behavioral harassment (Level B) is considered to 
have occurred when marine mammals are exposed to sounds at or above 160 
dB rms for impulse sounds (e.g., impact pile driving) and 120 dB rms 
for continuous sound (e.g., vibratory pile driving), but below 
injurious thresholds. NMFS uses these levels as guidelines to estimate 
when harassment may occur.
    There is a general lack of information regarding driving of timber 
piles in the available literature. However, underwater sound produced 
by impact driving of 12-in timber piles with use of cushion blocks, as 
is planned for the proposed activity, has been measured in the Bay area 
at 170 dB rms at 10 m (Caltrans, 2007). Caltrans (2007) has also 
measured SPLs associated with vibratory pile driving in the Bay area; 
vibratory driving for 12-in steel pipe piles was measured at 155 dB rms 
and for 36-in steel pipe piles at 170 dB rms, both at 10 m distance. 
Averaging these values provides a conservative estimate of 162.5 dB rms 
for 18-in piles, as would be used in the proposed activities. Using 
practical spreading loss--4.5 dB reduction in level for each doubling 
of distance from the source--to approximate site-specific sound 
propagation characteristics, these data provide estimated source levels 
of 185 dB rms for impact driving of 12-in timber piles with use of a 
cushion block and 177.5 dB rms for vibratory driving of 18-in steel 
pipe piles. On the basis of these estimated source levels, the 
estimated distances to various thresholds (presented for reference 
only) are presented in Table 2. Impact pile driving activity would not 
produce SPLs of sufficient intensity to potentially cause injury to 
pinnipeds (i.e., 190 dB rms), and SPLs produced by vibratory pile 
driving would be low enough to preclude the potential for injury to any 
marine mammal (i.e., below 180 dB rms).

     Table 2--Estimated Distances to Underwater Marine Mammal Sound
                     Thresholds During Pile Driving
------------------------------------------------------------------------
                                                                Distance
                          Threshold                               (m)
------------------------------------------------------------------------
Impact driving, pinniped injury (190 dB).....................        n/a
Impact driving, cetacean injury (180 dB).....................        2.2
Impact driving, disturbance (160 dB).........................         46
Impact driving, airborne disturbance (100 dB)................        5.3
Impact driving, airborne disturbance (90 dB).................         17
Vibratory driving, pinniped injury (190 dB)..................        n/a
Vibratory driving, cetacean injury (180 dB)..................        n/a
Vibratory driving, disturbance (133 dB \1\)..................        926
Vibratory driving, airborne disturbance (100 dB).............        6.8
Vibratory driving, airborne disturbance (90 dB)..............         22
------------------------------------------------------------------------
\1\ Distance to disturbance zone calculated on basis of ambient sound
  measurement of 133 dB rms in vicinity of San Francisco waterfront.
  Marine mammals present in the project area are likely acclimated to
  non-pulsed sound at levels well above NMFS' threshold for harassment
  for these types of sound (i.e., 120 dB rms).

    Precise exposure thresholds for airborne sounds have not been 
determined; however, monitoring of marine mammal reactions to rocket 
launches at Vandenberg Air Force Base (VAFB) has indicated that 
behavioral harassment may occur for harbor seals at received levels of 
90 dB re 20 [mu]Pa, while similar reactions may occur at levels of 100 
dB re 20 [mu]Pa for other pinniped species. There is a general lack of 
data regarding airborne SPLs from similar pile driving events; however, 
acoustic monitoring of pile driving events conducted recently by the 
U.S. Navy in Hood Canal provides approximate source levels of 114.5 and 
116.7 dB rms for impact driving and vibratory driving, respectively, of 
steel piles of 24-48 in diameter. Impact driving of 12-in timber piles 
with a cushion block would produce sound at somewhat lower intensity. 
It is extremely unlikely that pinnipeds would be exposed to airborne 
SPLs above the relevant thresholds, given the source levels and likely 
distance between pinnipeds and the activity. Please see Table 2 for 
estimated distances to thresholds.

Description of Marine Mammals in the Area of the Specified Activity

    Marine mammals with confirmed occurrences in San Francisco Bay are 
the harbor seal, California sea lion, harbor porpoise, elephant seal, 
gray whale (Eschrichtius robustus), humpback whale (Megaptera 
noveangliae), and sea otter (Enhydra lutris). The gray whale is 
typically observed migrating southward along the Central California 
coast between December and February and then again heading northward 
between February and July. Observations in San Francisco Bay are 
typically made from December through May, during the whales' coastal 
migration (USACE, 2011). Pile driving activities could overlap with the 
southbound migrating whales; however, southbound migrants typically 
travel farther offshore and are less likely to enter into the Bay. 
Humpback whales are considered extremely rare in San Francisco Bay and 
are highly unlikely to be present in the action area. Sea otters are 
under the jurisdiction of the U.S. Fish and Wildlife Service. 
Therefore, these three species are not discussed in detail.
    Typically, there is very little marine mammal activity in the 
waters immediately adjacent to the San Francisco waterfront, where pile 
driving activities are proposed. The general lack of marine mammal 
activity at the San Francisco waterfront--other than a California sea 
lion haul-out at Pier 39--is likely due to the high level of human 
activity, both urban and industrial in nature. The primary route for 
shipping traffic into and out of the Port of San Francisco and Port of 
Oakland is located between the San Francisco waterfront and Angel 
Island, approximately 5 km to the north. Amongst other uses, tugboat 
activities occur at Piers 15 and 17, ferry traffic around Pier 1 and 
along the waterfront to Piers 39 and 45,

[[Page 32579]]

marine shipping and cargo transport to Piers 80 A-D and Piers 92 and 
94-96, and cruise vessel traffic at Piers 27 and 35 (see Figures 1-2 of 
the application for relative locations). As noted previously, ambient 
underwater sound has been measured at 133 dB rms, significantly above 
NMFS threshold for behavioral harassment from non-pulsed sound (120 
dB).
    Harbor seals and California sea lion are the most common marine 
mammals in the Bay, and may be found at multiple sites either resting 
or foraging. There are no documented haul-outs in the vicinity of 
proposed construction or race events other than those discussed in 
succeeding sections. Various sources have observed pinnipeds resting on 
channel marker buoys throughout the Bay, on the shorelines of Alcatraz 
or Angel Island and along the San Francisco waterfront but these 
locations have not been defined as haul-out sites.

Harbor Seals

    Harbor seals in the eastern Pacific inhabit near-shore coastal and 
estuarine areas from Baja California, Mexico, to the Pribilof Islands 
in Alaska. In California, approximately 400-600 harbor seal haul-outs 
are widely distributed along the mainland and on offshore islands, 
including intertidal sandbars, rocky shores and beaches (Hanan, 1996).
    The harbor seal population in California is estimated at 
approximately 34,233 (Carretta et al., 2007). Counts of harbor seals in 
California showed a rapid increase from approximately 1972 to 1990, 
though net production rates appeared to decline from 1982 to 1994. The 
decrease in population growth rate has occurred at the same time as a 
decrease in human-caused mortality and may be an indication that the 
population is reaching its environmental carrying capacity. Harbor 
seals are not listed under the ESA and are not considered depleted or 
designated as a strategic stock under the MMPA.
    In general, harbor seals do not undertake long migrations, but do 
travel 300-500 km on occasion to find food or suitable breeding areas 
(Herder, 1986). Harbor seals are rarely found in pelagic waters and 
typically stay within the tidal and intertidal zones. On land, harbor 
seals haul out on rocky outcrops, mudflats, sandbars and sandy beaches 
with unrestricted access to water and with minimal human presence. 
Haul-out sites are important as resting sites for harbor seals, who 
feed opportunistically in shallow waters on fish, crustaceans, and 
cephalopods. Harbor seals are typically solitary while foraging, 
although small groups have been observed. They normally choose isolated 
sites for pupping.
    The harbor seal is a permanent resident in San Francisco Bay. The 
current Bay-Delta harbor seal population is estimated at between 500 
and 700 individuals (Green et al., 2006). Harbor seals have established 
haul-out sites at Castro Rocks in San Pablo Bay, Yerba Buena Island 
(YBI) in the Central Bay, and Mowry Slough in the South Bay (NOAA, 
2007). The south side of YBI, approximately 2.4 km distant from the 
nearest project site, is the nearest haul-out area and the only one 
that may potentially be affected by project activities. The YBI haul-
out is approximately 3.2 km from Pier 19, the only location where 
impact pile driving is proposed.
    Although not historically identified as a pupping site for harbor 
seals, recent observations at the year-round seal haul-out on the south 
side of YBI suggest that occasional pupping does occur at this location 
(Green et al., 2006). Pupping season for harbor seals in San Francisco 
Bay spans approximately March 15th through May 31st, with pup numbers 
generally peaking in late April or May. Individual seals may 
occasionally haul out farther to the west and southwest of the main 
haul-out at YBI site, depending on space availability and conditions at 
the main haul-out area. Harbor seals present near the San Francisco 
waterfront would likely be transiting to and from YBI or 
opportunistically foraging.

California Sea Lions

    California sea lions range from southern Mexico to British 
Columbia, Canada. The entire U.S. population has been estimated at 
238,000, and grew at a rate of approximately 6 percent annually between 
1975 and 2005 (Carretta et al., 2007). Sea lions can be found at sea 
from the surf zone out to nearshore and pelagic waters. On land, sea 
lions are found resting and breeding in groups of various sizes, and 
haul out on rocky surfaces and outcroppings and beaches, as well as on 
manmade structures such as jetties. Sea lions prefer haul-out sites and 
rookeries near abundant food supplies, with easy access to water, 
although they may occasionally travel up rivers and bays in search of 
food. California sea lions are not listed under the ESA and are not 
considered depleted or designated as a strategic stock under the MMPA.
    California sea lions exhibit seasonal migration patterns organized 
around their breeding activity. Sea lions breed at large rookeries in 
the Channel Islands in southern California, and on both sides of the 
Baja California peninsula, typically from May to August. Females tend 
to remain close to the rookeries throughout the year, while males 
migrate north after the breeding season in the late summer before 
migrating back south to the breeding grounds in the spring (CDFG, 
1990). No established rookeries are known north of Point Reyes, 
California, but large numbers of subadult and non-breeding or post-
breeding male California sea lions are found throughout the Pacific 
Northwest. There is a mean seasonal pattern of peak numbers occurring 
in the northwest during fall, but local areas show high annual and 
seasonal variability. Sea lions feed on fish and cephalopods. Although 
solitary feeders, sea lions often hunt in groups, which can vary in 
size according to the abundance of prey (CDFG, 1990).
    California sea lions are typically found within the San Francisco 
Bay region while migrating to and from their primary breeding areas in 
the Channel Islands, and in association with herring and salmon 
spawning migrations. Sea lions haul out on offshore rocks, sandy 
beaches, floating docks, wharfs, vessels, and other man-made structures 
in the Bay, where winter numbers have historically been observed to be 
over 500 animals (Goals Project, 2000). Although some animals may 
remain in the Bay year-round, sea lions typically begin to appear in 
August. Numbers then increase gradually before a sudden increase in 
December, when the herring run results in greatest numbers (Dec-Feb). 
Following the winter peak, numbers decline to just a few animals by 
summer months.
    California sea lions are typically observed at Angel Island and 
occupying the docks near Pier 39, which is the largest haul-out in San 
Francisco Bay (Bauer, 1999). As many as 800 sea lions have been counted 
at Pier 39, although the aggregations have decreased in size in recent 
years, possibly coincident with a fluctuating decrease in the herring 
population in the Bay. No other sea lion haul-out sites have been 
identified in the Bay, there are no known breeding sites within San 
Francisco Bay, and no pupping has been observed at Pier 39 site or at 
any other site in San Francisco Bay under normal conditions (USACE, 
2011). Sea lions present at the Pier 39 haul-out are described 
anecdotally as being well-acclimated to human presence and activity.
    Pier 27 and Marina Green--both less than 1.6 km away from Pier 39--
are the closest locations where vibratory pile driving would be 
conducted. Pier 19, where impact pile driving would occur, is also less 
than 1.6 km distant.

[[Page 32580]]

California sea lions may forage in the waters of and adjacent to the 
sites where construction is proposed and where the race events would 
occur.

Harbor Porpoise

    Harbor porpoises belong to the Phocoenid (porpoise) family and are 
found extensively along the Pacific U.S. coast. Harbor porpoises are 
small, with males reaching average lengths of approximately 5 ft (1.5 
m); Females are slightly larger with an average length of 5.5 ft (1.7 
m). The average adult harbor porpoise weighs between 135-170 lb (61-77 
kg). Harbor porpoises have a dark grey coloration on their backs, with 
their belly and throats white. They have a dark grey chin patch and 
intermediate shades of grey along their sides.
    Harbor porpoises are generally found in cool temperate to subarctic 
waters over the continental shelf in both the North Atlantic and North 
Pacific (Read, 1999). This species is seldom found in waters warmer 
than 17 [deg]C (63 [deg]F; Read, 1999) or south of Point Conception 
(Hubbs, 1960; Barlow and Hanan, 1995). Harbor porpoises can be found 
year-round primarily in the shallow coastal waters of harbors, bays, 
and river mouths (Green et al., 1992). Along the Pacific coast, harbor 
porpoises occur from Monterey Bay, California to the Aleutian Islands 
and west to Japan (Reeves et al., 2002).
    Harbor porpoises are non-social animals usually seen in small 
groups of two to five animals. Little is known about their social 
behavior. Harbor porpoises can be opportunistic foragers but primarily 
consume schooling forage fish (Osmek et al., 1996; Bowen and Siniff, 
1999; Reeves et al., 2002). Females reach sexual maturity at three to 
four years of age and may give birth every year for several years in a 
row. Calves are born in late spring (Read, 1990; Read and Hohn, 1995).
    Recent preliminary genetic analyses of samples ranging from 
Monterey, CA to Vancouver Island, BC indicate that there is small-scale 
subdivision within the U.S. portion of this range (Chivers et al., 
2002). Although geographic structure exists along an almost continuous 
distribution of harbor porpoises from California to Alaska, stock 
boundaries are difficult to draw because any rigid line is generally 
arbitrary from a biological perspective. Nevertheless, based on genetic 
data and density discontinuities identified from aerial surveys, NMFS 
identifies eight stocks in the Northeast Pacific Ocean. Pacific coast 
harbor porpoise stocks include: (1) Monterey Bay, (2) San Francisco-
Russian River, (3) northern California/southern Oregon, (4) Oregon/
Washington coastal, (5) inland Washington, (6) Southeast Alaska, (7) 
Gulf of Alaska, and (8) Bering Sea. Only individuals from the San 
Francisco-Russian River stock are likely to occur in the project area. 
Based on 2002-07 aerial surveys under good survey conditions the 
estimate of abundance for this stock is 9,189 animals (Carretta et al., 
2009). Abundance of the stock has steadily increased since 1993. The 
Golden Gate Cetacean Research Organization (GGCR) has suggested that 
the species is returning to San Francisco Bay after a general absence 
of approximately 65 years (GGCR, 2010). This re-emergence is not unique 
to San Francisco Bay, but rather may be indicative of harbor porpoise 
increases and expansions in general along the west coast. Harbor 
porpoises are not listed under the ESA and are not considered depleted 
or designated as a strategic stock under the MMPA.
    Harbor porpoises, although not commonly sighted in San Francisco 
Bay, have been observed traveling in small pods of two to three animals 
in the Central Bay and below the Golden Gate Bridge on occasion and in 
some instances displaying mating behavior. Recent observations of 
harbor porpoises have been reported by GGCR researchers off Cavallo 
Point, outside Raccoon Strait between Tiburon and Angel Island, off 
Fort Point and as far into the Bay as Carquinez Strait (Perlman, 2010). 
In addition, the California Department of Transportation reported 
observing a single harbor porpoise in 2000 in the vicinity of YBI 
during monitoring associated with bridge construction. Harbor porpoise 
presence in the project area is nevertheless considered rare.

Elephant Seals

    Populations of northern elephant seals in the U.S. and Mexico are 
derived from a few tens or hundreds of individuals surviving in Mexico 
after being nearly hunted to extinction (Stewart et al., 1994). Given 
the recent derivation of most rookeries, no genetic differentiation 
would be expected. Although movement and genetic exchange continues 
between rookeries, most elephant seals return to their natal rookeries 
when they start breeding (Huber et al., 1991). The California breeding 
population is now demographically isolated from the Baja California 
population and is considered to be a separate stock. Based on the 
estimated 35,549 pups born in California in 2005, the California stock 
was estimated at approximately 124,000 (Carretta et al. 2009). Based on 
trends in pup counts, northern elephant seal colonies were continuing 
to grow in California through 2005 (Carretta et al., 2009). The 
elephant seal is not listed under the ESA and is not considered 
depleted or designated as a strategic stock under the MMPA.
    Northern elephant seals breed and give birth in California and Baja 
California, Mexico, primarily on offshore islands from December to 
March (Stewart et al., 1994; Stewart and Huber, 1993). Gestation lasts 
around 11 months, and pups are born in early winter from December to 
January. Northern elephant seals are polygamous; males establish 
dominance over large groups of females during the breeding season. 
Males feed near the eastern Aleutian Islands and in the Gulf of Alaska, 
and females feed further south (Stewart and Huber, 1993; Le Boeuf et 
al., 1993). Adults return to land between March and August to molt, 
with males returning later than females. Adults return to their feeding 
areas again between their spring/summer molting and their winter 
breeding seasons.
    Individual juvenile elephant seals have been reported entering the 
Bay in the past few years between March and August, with an occasional 
report in October and November. Elephant Seals do not have any 
established haul out sites in the Bay, but occasional sightings have 
occurred at Crissy Field, approximately 1 km from the nearest project 
site. Elephant seals are considered rare in the Bay.

Potential Effects of the Specified Activity on Marine Mammals

    NMFS has determined that pile driving, as outlined in the project 
description, has the potential to result in behavioral harassment of 
marine mammals that may be swimming, foraging, or resting in the 
project vicinity while pile driving is being conducted. Behavioral 
disturbance is also possible when helicopter overflights or fireworks 
displays occur.

Marine Mammal Hearing

    The primary effect on marine mammals anticipated from the specified 
activities would result from exposure of animals to underwater sound. 
Exposure to sound can affect marine mammal hearing or cause changes in 
behavior. When considering the influence of various kinds of sound on 
the marine environment, it is necessary to understand that different 
kinds of marine life are sensitive to different frequencies of sound. 
Based on available behavioral data, audiograms derived using auditory 
evoked potential techniques, anatomical modeling, and other data, 
Southall et al. (2007)

[[Page 32581]]

designate functional hearing groups for marine mammals and estimate the 
lower and upper frequencies of functional hearing of the groups. The 
functional groups and the associated frequencies are indicated below 
(though animals are less sensitive to sounds at the outer edge of their 
functional range and most sensitive to sounds of frequencies within a 
smaller range somewhere in the middle of their functional hearing 
range):
     Low frequency cetaceans (13 species of mysticetes): 
Functional hearing is estimated to occur between approximately 7 Hz and 
22 kHz;
     Mid-frequency cetaceans (32 species of dolphins, six 
species of larger toothed whales, and 19 species of beaked and 
bottlenose whales): Functional hearing is estimated to occur between 
approximately 150 Hz and 160 kHz;
     High frequency cetaceans (six species of true porpoises, 
four species of river dolphins, two members of the genus Kogia, and 
four dolphin species of the genus Cephalorhynchus): Functional hearing 
is estimated to occur between approximately 200 Hz and 180 kHz; and
     Pinnipeds in water: functional hearing is estimated to 
occur between approximately 75 Hz and 75 kHz, with the greatest 
sensitivity between approximately 700 Hz and 20 kHz.
    As mentioned previously in this document, three pinniped and one 
cetacean species may occur in the proposed project area during the 
project timeframe. The harbor porpoise is classified as a high 
frequency cetacean (Southall et al., 2007).

Underwater Sound Effects

    Potential Effects of Pile Driving Sound--The effects of sounds from 
pile driving might generally result in one or more of the following: 
Temporary or permanent hearing impairment, non-auditory physical or 
physiological effects, behavioral disturbance, and masking (Richardson 
et al., 1995; Gordon et al., 2004; Nowacek et al., 2007; Southall et 
al., 2007). The effects of pile driving on marine mammals are dependent 
on several factors, including the size, type, and depth of the animal; 
the depth, intensity, and duration of the pile driving sound; the depth 
of the water column; the substrate of the habitat; the standoff 
distance between the pile and the animal; and the sound propagation 
properties of the environment. Impacts to marine mammals from pile 
driving activities are expected to result primarily from acoustic 
pathways. As such, the degree of effect is intrinsically related to the 
received level and duration of the sound exposure, which are in turn 
influenced by the distance between the animal and the source. The 
further away from the source, the less intense the exposure should be. 
The substrate and depth of the habitat affect the sound propagation 
properties of the environment. Shallow environments are typically more 
structurally complex, which leads to rapid sound attenuation. In 
addition, substrates that are soft (e.g., sand) would absorb or 
attenuate the sound more readily than hard substrates (e.g., rock) 
which may reflect the acoustic wave. Soft porous substrates would also 
likely require less time to drive the pile, and possibly less forceful 
equipment, which would ultimately decrease the intensity of the 
acoustic source.
    In the absence of mitigation, impacts to marine species would be 
expected to result from physiological and behavioral responses to both 
the type and strength of the acoustic signature (Viada et al., 2008). 
The type and severity of behavioral impacts are more difficult to 
define due to limited studies addressing the behavioral effects of 
sound on marine mammals. Potential effects from impulsive sound sources 
can range in severity, ranging from effects such as behavioral 
disturbance, tactile perception, physical discomfort, slight injury of 
the internal organs and the auditory system, to mortality (Yelverton et 
al., 1973; O'Keefe and Young, 1984; DoN, 2001b).
    Hearing Impairment and Other Physical Effects--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 not recoverable, or 
temporary (TTS), in which case the animal's hearing threshold would 
recover over time (Southall et al., 2007). Marine mammals depend on 
acoustic cues for vital biological functions, (e.g., orientation, 
communication, finding prey, avoiding predators); thus, TTS may result 
in reduced fitness in survival and reproduction, either permanently or 
temporarily. However, this depends on the frequency and duration of 
TTS, as well as the biological context in which it occurs. TTS of 
limited duration, occurring in a frequency range that does not coincide 
with that used for recognition of important acoustic cues, would have 
little to no effect on an animal's fitness. Repeated sound exposure 
that leads to TTS could cause PTS. PTS, in the unlikely event that it 
occurred, would constitute injury, but TTS is not considered injury 
(Southall et al., 2007). It is unlikely that the project would result 
in any cases of temporary or especially permanent hearing impairment or 
any significant non-auditory physical or physiological effects for 
reasons discussed later in this document. Some behavioral disturbance 
is expected, but it is likely that this would be localized and short-
term because of the short project duration.
    Several aspects of the planned monitoring and mitigation measures 
for this project (see the ``Proposed Mitigation'' and ``Proposed 
Monitoring and Reporting'' sections later in this document) are 
designed to detect marine mammals occurring near the pile driving to 
avoid exposing them to sound pulses that might, in theory, cause 
hearing impairment. In addition, many cetaceans are likely to show some 
avoidance of the area where received levels of pile driving sound are 
high enough that hearing impairment could potentially occur. In those 
cases, the avoidance responses of the animals themselves would reduce 
or (most likely) avoid any possibility of hearing impairment. Non-
auditory physical effects may also occur in marine mammals exposed to 
strong underwater pulsed sound. It is especially unlikely that any 
effects of these types would occur during the present project given the 
brief duration of exposure for any given individual and the planned 
monitoring and mitigation measures. The following subsections discuss 
in somewhat more detail the possibilities of TTS, PTS, and non-auditory 
physical effects.
    Temporary Threshold Shift--TTS is the mildest form of hearing 
impairment that can occur during exposure to a strong sound (Kryter, 
1985). While experiencing TTS, the hearing threshold rises, and a sound 
must be stronger in order to be heard. In terrestrial mammals, TTS can 
last from minutes or hours to days (in cases of strong TTS). For sound 
exposures at or somewhat above the TTS threshold, hearing sensitivity 
in both terrestrial and marine mammals recovers rapidly after exposure 
to the sound ends. Few data on sound levels and durations necessary to 
elicit mild TTS have been obtained for marine mammals, and none of the 
published data concern TTS elicited by exposure to multiple pulses of 
sound. Available data on TTS in marine mammals are summarized in 
Southall et al. (2007).
    Given the available data, the received level of a single pulse 
(with no frequency weighting) might need to be approximately 186 dB re 
1 [mu]Pa\2\-s (i.e.,

[[Page 32582]]

186 dB sound exposure level [SEL] or approximately 221-226 dB pk-pk) in 
order to produce brief, mild TTS. Exposure to several strong pulses 
that each have received levels near 190 dB re 1 [mu]Pa rms (175-180 dB 
SEL) might result in cumulative exposure of approximately 186 dB SEL 
and thus slight TTS in a small odontocete, assuming the TTS threshold 
is (to a first approximation) a function of the total received pulse 
energy. Source levels for the proposed activities are not expected to 
exceed 190 dB re 1 [mu]Pa rms.
    The above TTS information for odontocetes is derived from studies 
on the bottlenose dolphin (Tursiops truncatus) and beluga whale 
(Delphinapterus leucas). There is no published TTS information for 
other species of cetaceans. However, preliminary evidence from a harbor 
porpoise exposed to pulsed sound suggests that its TTS threshold may 
have been lower (Lucke et al., 2009). To avoid the potential for 
injury, NMFS has determined that cetaceans should not be exposed to 
pulsed underwater sound at received levels exceeding 180 dB re 1 [mu]Pa 
rms. As summarized above, data that are now available imply that TTS is 
unlikely to occur unless odontocetes are exposed to pile driving pulses 
stronger than 180 dB re 1 [mu]Pa rms.
    Permanent Threshold Shift--When PTS occurs, there is physical 
damage to the sound receptors in the ear. In severe cases, there can be 
total or partial deafness, while in other cases the animal has an 
impaired ability to hear sounds in specific frequency ranges (Kryter, 
1985). There is no specific evidence that exposure to pulses of sound 
can cause PTS in any marine mammal. However, given the possibility that 
mammals close to pile driving activity might incur TTS, there has been 
further speculation about the possibility that some individuals 
occurring very close to pile driving might incur PTS. Single or 
occasional occurrences of mild TTS are not indicative of permanent 
auditory damage, but repeated or (in some cases) single exposures to a 
level well above that causing TTS onset might elicit PTS.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals but are assumed to be similar to those in humans and 
other terrestrial mammals. PTS might occur at a received sound level at 
least several decibels above that inducing mild TTS if the animal were 
exposed to strong sound pulses with rapid rise time. Based on data from 
terrestrial mammals, a precautionary assumption is that the PTS 
threshold for impulse sounds (such as pile driving pulses as received 
close to the source) is at least 6 dB higher than the TTS threshold on 
a peak-pressure basis and probably greater than 6 dB (Southall et al., 
2007). On an SEL basis, Southall et al. (2007) estimated that received 
levels would need to exceed the TTS threshold by at least 15 dB for 
there to be risk of PTS. Thus, for cetaceans, Southall et al. (2007) 
estimate that the PTS threshold might be an M-weighted SEL (for the 
sequence of received pulses) of approximately 198 dB re 1 [mu]Pa\2\-s 
(15 dB higher than the TTS threshold for an impulse). Given the higher 
level of sound necessary to cause PTS as compared with TTS, it is 
considerably less likely that PTS could occur.
    Non-auditory Physiological Effects--Non-auditory physiological 
effects or injuries that theoretically might occur in marine mammals 
exposed to strong underwater sound include stress, neurological 
effects, bubble formation, resonance effects, and other types of organ 
or tissue damage (Cox et al., 2006; Southall et al., 2007). Studies 
examining such effects are limited. In general, little is known about 
the potential for pile driving to cause auditory impairment or other 
physical effects in marine mammals. Available data suggest that such 
effects, if they occur at all, would presumably be limited to short 
distances from the sound source and to activities that extend over a 
prolonged period. The available data do not allow identification of a 
specific exposure level above which non-auditory effects can be 
expected (Southall et al., 2007) or any meaningful quantitative 
predictions of the numbers (if any) of marine mammals that might be 
affected in those ways. Marine mammals that show behavioral avoidance 
of pile driving, including some odontocetes and some pinnipeds, are 
especially unlikely to incur auditory impairment or non-auditory 
physical effects.
    Measured source levels from impact pile driving can be as high as 
214 dB re 1 [mu]Pa at 1 m (3.3 ft). Although no marine mammals have 
been shown to experience TTS or PTS as a result of being exposed to 
pile driving activities, captive bottlenose dolphins and beluga whales 
exhibited changes in behavior when exposed to strong pulsed sounds 
(Finneran et al., 2000, 2002, 2005). The animals tolerated high 
received levels of sound before exhibiting aversive behaviors. 
Experiments on a beluga whale showed that exposure to a single watergun 
impulse at a received level of 207 kPa (30 psi) p-p, which is 
equivalent to 228 dB p-p re 1 [mu]Pa, 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 four minutes of the 
exposure (Finneran et al., 2002). 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 sound 
exposure in terms of SEL than from the single watergun impulse 
(estimated at 188 dB re 1 [mu]Pa\2\-s) 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 sound levels for a prolonged period of time. 
Based on the best scientific information available, these SPLs are far 
below the thresholds that could cause TTS or the onset of PTS.

Disturbance Reactions

    Disturbance includes a variety of effects, including subtle changes 
in behavior, more conspicuous changes in activities, and displacement. 
Reactions to sound, if any, depend on species, state of maturity, 
experience, current activity, reproductive state, time of day, and many 
other factors (Richardson et al., 1995; Wartzok et al., 2004; Southall 
et al., 2007; Weilgart, 2007). Behavioral responses to sound are highly 
variable and context-specific. For each potential behavioral change, 
the magnitude of the change ultimately determines the severity of the 
response. A number of factors may influence an animal's response to 
sound, including its previous experience, its auditory sensitivity, its 
biological and social status (including age and sex), and its 
behavioral state and activity at the time of exposure.
    Habituation can occur when an animal's response to a stimulus wanes 
with repeated exposure, usually in the absence of unpleasant associated 
events (Wartzok et al., 2003/04). Animals are most likely to habituate 
to sounds that are predictable and unvarying. The opposite process is 
sensitization, when an unpleasant experience leads to subsequent 
responses, often in the form of avoidance, at a lower level of 
exposure. Behavioral state may affect the type of response as well. For 
example, animals that are resting may show greater behavioral change in 
response to disturbing sound levels than animals that are highly 
motivated to remain in an area for feeding (Richardson et al., 1995; 
NRC, 2003; Wartzok et al., 2003/04).
    Controlled experiments with captive marine mammals showed 
pronounced behavioral reactions, including

[[Page 32583]]

avoidance of loud sound sources (Ridgway et al., 1997; Finneran et al., 
2003). Observed responses of wild marine mammals to loud pulsed sound 
sources (typically seismic guns or acoustic harassment devices, but 
also including pile driving) have been varied but often consist of 
avoidance behavior or other behavioral changes suggesting discomfort 
(Morton and Symonds, 2002; Caltrans, 2001, 2006; see also Gordon et 
al., 2004; Wartzok et al., 2003/04; Nowacek et al., 2007). Responses to 
continuous sound, such as vibratory pile installation, have not been 
documented as well as responses to pulsed sounds.
    With both types of pile driving, it is likely that the onset of 
pile driving could result in temporary, short term changes in an 
animal's typical behavior and/or avoidance of the affected area. These 
behavioral changes may include (Richardson et al., 1995): 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 sound sources are located; and/or flight responses (e.g., 
pinnipeds flushing into water from haul-outs or rookeries). Pinnipeds 
may increase their haul-out time, possibly to avoid in-water 
disturbance (Caltrans 2001, 2006). Since pile driving typically occurs 
for short periods of time, and because marine mammals present at the 
San Francisco waterfront are likely acclimated to a loud environment 
and heavy urban and industrial usage of the area, it is unlikely to 
result in permanent displacement. Any potential impacts from pile 
driving activities could be experienced by individual marine mammals, 
but would not be likely to cause population level impacts, or affect 
the long-term fitness of the species.
    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, or reproduction. Significant 
behavioral modifications that could potentially lead to effects on 
growth, survival, or reproduction include:
     Drastic changes 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
     Cessation of feeding or social interaction.
    The onset of behavioral disturbance from anthropogenic sound 
depends on both external factors (characteristics of sound sources and 
their paths) and the specific characteristics of the receiving animals 
(hearing, motivation, experience, demography) and is difficult to 
predict (Southall et al., 2007).

Auditory Masking

    Natural and artificial sounds can disrupt behavior by masking, or 
interfering with, a marine mammal's ability to hear other sounds. 
Masking occurs when the receipt of a sound is interfered with by 
another coincident sound at similar frequencies and at similar or 
higher levels. Chronic exposure to excessive, though not high-
intensity, sound could cause masking at particular 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, under certain circumstances, 
marine mammals whose acoustical sensors or environment are being 
severely masked could also be impaired from maximizing their 
performance fitness in survival and reproduction. If the coincident 
(masking) sound were man-made, it could be potentially harassing if it 
disrupted hearing-related behavior. It is important to distinguish TTS 
and PTS, which persist after the sound exposure, from masking, which 
occurs during the sound exposure. Because masking (without resulting in 
TS) is not associated with abnormal physiological function, it is not 
considered a physiological effect, but rather a potential behavioral 
effect.
    The frequency range of the potentially masking sound is important 
in determining any potential behavioral impacts. Because sound 
generated from in-water pile driving is mostly concentrated at low 
frequency ranges, it may have less effect on high frequency 
echolocation sounds made by porpoises. However, lower frequency man-
made sounds are more likely to affect detection of communication calls 
and other potentially important natural sounds such as surf and prey 
sound. It may also affect communication signals when they occur near 
the sound band 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 has the potential to impact species at population, 
community, or even ecosystem levels, as well as at individual levels. 
Masking affects both senders and receivers of the signals and can 
potentially have long-term chronic effects on marine mammal species and 
populations. Recent research suggests that low frequency ambient sound 
levels have increased by as much as 20 dB (more than three times in 
terms of SPL) in the world's ocean from pre-industrial periods, and 
that most of these increases are from distant shipping (Hildebrand, 
2009). All anthropogenic sound sources, such as those from vessel 
traffic, pile driving, and dredging activities, contribute to the 
elevated ambient sound levels, thus intensifying masking. However, the 
sum of sound from the proposed activities is confined in an area of 
inland waters that is bounded by landmass; therefore, the sound 
generated is not expected to contribute to increased ocean ambient 
sound.
    The most intense underwater sounds in the proposed action are those 
produced by impact pile driving, although the proposed activity 
involves the striking of only relatively small diameter timber piles, 
meaning that source levels would be much lower than are typically 
produced by impact pile driving. Given that the energy distribution of 
pile driving covers a broad frequency spectrum, sound from these 
sources would likely be within the audible range of animals in the 
vicinity. Impact pile driving activity is relatively short-term, with 
rapid pulses occurring for short periods of time. The probability for 
impact pile driving resulting from this proposed action masking 
acoustic signals important to the behavior and survival of marine 
mammal species is likely to be negligible. Vibratory pile driving is 
also relatively short-term, producing sound from rapid oscillations. It 
is possible that vibratory pile driving resulting from this proposed 
action may mask acoustic signals important to the behavior and survival 
of marine mammal species, but the short-term duration and limited 
affected area, coupled with high levels of ambient noise in the action 
area, would result in a negligible impact from masking.

Airborne Sound Effects

    Marine mammals that occur in the project area could be exposed to 
airborne sounds associated with pile driving, helicopter overflights, 
or fireworks displays that have the potential to cause harassment, 
depending on their distance from pile

[[Page 32584]]

driving activities. Airborne pile driving sound would have less impact 
on cetaceans than pinnipeds because sound from atmospheric sources does 
not transmit well underwater (Richardson et al., 1995); thus, airborne 
sound would only be an issue for hauled-out pinnipeds in the project 
area or those pinnipeds in the water but with their heads above water. 
Given the busy and loud environment within which the proposed 
activities would occur, and the degree of acclimatization displayed by 
pinnipeds at Pier 39, it is unlikely that airborne sound from pile 
driving, or sound alone from fireworks or helicopters, would cause 
behavioral responses similar to those discussed above in relation to 
underwater sound. However, anthropogenic sound could potentially cause 
pinnipeds to exhibit changes in their normal behavior, such as 
reduction in vocalizations, or cause them to temporarily abandon their 
habitat and move further from the source. Studies by Blackwell et al. 
(2004) and Moulton et al. (2005) indicate a tolerance or lack of 
response to unweighted airborne sounds as high as 112 dB peak and 96 dB 
rms.

Helicopter Operations and Fireworks Displays

    Potential effects to pinnipeds could result from both acoustic (as 
described in the preceding section) and non-acoustic stimuli. It is 
generally difficult to ascertain whether pinnipeds displaying 
behavioral reactions to these activities are reacting to sound or to 
visual stimuli (e.g., physical presence of aircraft, shadow of 
aircraft, light from fireworks).
    The functional hearing range for pinnipeds in air is 75 Hz to 30 
kHz (Southall et al., 2007). Richardson et al. (1995) note that 
dominant tones in noise spectra from helicopters are generally below 
500 Hz, while Kastak and Schustermann (1995) state that the in air 
hearing sensitivity--which is generally less than the in-water hearing 
sensitivity for pinnipeds--decreases below 2 kHz, and that pinnipeds 
appear generally to be considerably less sensitive to airborne sounds 
below 10 kHz than are humans. There is a dearth of information on 
acoustic effects of helicopter overflights on pinniped hearing and 
communication (Richardson et al., 1995) and to our knowledge, there has 
been no specific documentation of temporary threshold shift (TTS), let 
alone permanent threshold shift (PTS), in free-ranging pinnipeds 
exposed to helicopter operations during realistic field conditions.
    Typical reactions of hauled-out pinnipeds to aircraft that have 
been observed include looking up at the aircraft, moving on land, or 
entering the water. Hauled out pinnipeds have been observed diving into 
the water when approached by a low-flying aircraft or helicopter 
(Richardson et al., 1995). Richardson et al. (1995) note that responses 
can vary based on differences in aircraft type, altitude, and flight 
pattern. Additionally, a study conducted by Born et al. (1999) found 
that wind chill, time of day, and relative wind direction were factors 
in the level of response.
    As for helicopter overflights, few data are available regarding 
pinniped reactions to fireworks displays, although there is information 
from monitoring of fireworks displays conducted by the Monterey Bay 
National Marine Sanctuary (MBNMS). In some display locations, marine 
mammals may avoid or temporarily depart the impact area during the 
hours immediately prior to the beginning of the fireworks display due 
to increased human recreational activities associated with the overall 
celebration event, and as a fireworks presentation progresses, most 
marine mammals generally evacuate the impact area. The proposed display 
locations are approximately 800-1,000 m from Pier 39, where California 
sea lions haul out during parts of the year.
    The MBNMS has monitored commercial fireworks displays for potential 
impacts to marine life and habitats since 1993. Though monitoring 
techniques and intensity have varied over the years and visual 
monitoring of wildlife abundance and behavioral responses to nighttime 
displays is challenging, observed impacts have been consistent. In 
summary, nearly two decades of observing sea lion reactions to 
fireworks displays gives the following general observations: Sea lions 
(1) begin leaving the breakwater as soon as the fireworks begin; (2) 
clear completely off after an aerial salute or quick succession of loud 
effects; (3) usually begin returning within a few hours of the end of 
the display; and (4) are present on the breakwater at pre-firework 
numbers by the following morning. The loud sound bursts and pressure 
waves created by the exploding shells appear to cause more wildlife 
disturbance than the illumination effects. In particular, the 
percussive aerial salute shells have been observed to elicit a strong 
flight response in California sea lions in the vicinity of the impact 
area (within 800 m of the launch site). No signs of wildlife injury or 
mortality have ever been discovered as a result of managed fireworks 
displays. It is unclear whether observed reactions at Monterey would be 
applicable to animals at the San Francisco waterfront, where human 
activity, including fireworks, is more frequent and of greater 
intensity. It is possible that animals at Pier 39 would display lesser 
reactions to fireworks displays.
    In 2007, MBNMS conducted acoustic monitoring for the City of 
Monterey Independence Day fireworks display. The fireworks display 
began with two sets of fireworks detonations and ended with a grand 
finale of multiple explosions after 20 minutes. The average sound level 
measured during the hour containing the fireworks display was 72.9 dB, 
approximately 14 dB greater than ambient levels recorded before the 
display. The loudest sound recorded during the event was associated 
with the detonation of a 10-in shell, and was measured at 133.9 dB 
(peak). Overall, sound generated during the display was low- to mid-
frequency and ranged from 97 to 107 dB rms, while the majority of the 
fireworks detonations ranged from 112 to 124 dB rms.
    Aerial shells produce flashes of light that can be brilliant 
(exceeding 30,000 candela) and can occur in rapid succession. Loud 
explosive and crackling sound effects stem primarily from salutes and 
bursting charges at altitude. Humans and wildlife on the ground and on 
the surface of the water may feel the sound waves and the accompanying 
rapid shift of ambient atmospheric pressure. Sound propagates further 
from high altitude shells than low altitude shells, thus ensonifying 
more surface area on the ground and water, as they are not blocked 
significantly by buildings and landforms. The sound from the lifting 
charge detonation is vectored upward through the mortar tube opening 
and reports as a dull thump to bystanders on the ground, far less 
conspicuous than the high-level aerial bursts. The intensity of an 
aerial show can be amplified by increasing the number of shells used, 
the pace of the barrage, and the length of the display.
    Low-level devices reach a maximum altitude of 200 ft (61 m). The 
acute impact area can extend to 1 mi (1.6 km) from the center of the 
ignition point depending on the size and flight patterns of 
projectiles, maximum altitude of projectiles, the type of special 
effects, wind direction, atmospheric conditions, and local structures 
and topography. Low-level devices also produce brilliant flashes and 
fountains of light and sparks accompanied by small explosions, popping, 
and crackling sounds. Since

[[Page 32585]]

they are lower in altitude than aerial shells, sound and light effects 
impact a smaller area. Low-level devices do not typically employ large 
black powder charges as do aerial shells, but are often used in large 
numbers in concert with one another and in rapid succession, producing 
intense localized effects.
    Regular rocket launches at VAFB, which produce sound and light 
somewhat similar to that produced by fireworks, do not appear to have 
had long-term effects on the harbor seal population there. The total 
population of harbor seals at VAFB has been estimated to be increasing 
at an annual rate of 12.6 percent, despite five to seven space vehicle 
launches per year. Thus, there appear to be only short-term disturbance 
effects to harbor seals as a result of launch noise (SRS Technologies, 
2001). Harbor seals will temporarily leave their haul-out when exposed 
to launch noise; however, they generally return to the haul-out within 
one hour.
    Based on the available information, any pinnipeds in the vicinity 
of these activities are only anticipated to have short-term behavioral 
reactions to the helicopter flying overhead or to fireworks displays. 
Those animals that do flee the haul-out would be anticipated to return 
shortly after the helicopter leaves the area or within hours of the 
fireworks display. Harassment as a result of exceedance of sound 
thresholds is likely not possible, as the distance between helicopters 
or fireworks displays and the Pier 39 haul-out would preclude such 
effects; in addition, if for some reason an animal were hauled out 
closer to the fireworks display it would likely flee before the loudest 
effects were discharged. On the basis of the preceding discussion, we 
have preliminarily determined that potential impacts to marine mammals 
would consist of no more than behavioral harassment of limited duration 
and limited intensity (i.e., temporary flushing at most).

Anticipated Effects on Habitat

    No permanent detrimental impacts to marine mammal habitat are 
expected to result from the proposed activities. Pile driving may 
impact prey species and marine mammals by causing temporary avoidance 
or abandonment of the immediate area. Site conditions are expected to 
be substantively unchanged from existing conditions. In addition, local 
habitat as it exists is significantly degraded as a result of the 
history of urban and industrial activity. Overall, the proposed 
activity is not expected to cause significant or long-term adverse 
impacts on marine mammal habitat or to the prey base for marine 
mammals.

Proposed Mitigation

    In order to issue an IHA 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.
    Estimated distances to various sound thresholds were described 
previously under ``Sound Thresholds,'' and would be used to establish 
zones of influence (ZOIs) (described in following sections) to be used 
as mitigation measures for pile driving activities. ZOIs are often used 
to effectively represent the mitigation zone that would be established 
around each pile to prevent Level A harassment of marine mammals. In 
addition to the specific measures described later, ACEA and the Port 
would employ the following general mitigation measures:
     All work would be performed according to the requirements 
and conditions of the regulatory permits issued by federal, state, and 
local governments.
     Briefings would be conducted between the project 
construction supervisors and crew and marine mammal observer(s) (MMO) 
as necessary prior to the start of all pile-driving activity, and when 
new personnel join the work, to explain responsibilities, communication 
procedures, marine mammal monitoring protocol, and operational 
procedures.
     Contractors for construction work would comply with all 
applicable equipment sound standards and ensure that all construction 
equipment has sound control devices no less effective than those 
provided on the original equipment (i.e., equipment may not have been 
modified in such a way that it is louder than it was initially).
     Only one impact pile driver may be operated 
simultaneously.
     For impact driving of timber piles, a cushion block or 
similar device would be used for sound attenuation at all times.

Monitoring and Shutdown

    Shutdown Zones--For all pile driving and removal activities, a 
shutdown zone (defined as, at minimum, the area in which SPLs equal or 
exceed 180 dB rms) would be established when applicable. For the 
proposed activity, this would be required only for impact pile driving. 
The purpose of a shutdown zone is to define an area within which 
shutdown of activity would occur upon sighting of a marine mammal (or 
in anticipation of an animal entering the defined area), thus 
preventing injury, serious injury, or death of marine mammals. During 
all impact pile driving, the Port would establish a conservative 
shutdown zone of 10 m radius around each pile to avoid exposure of 
marine mammals to sound levels that could potentially cause injury. The 
shutdown zone would be monitored during all impact pile driving.
    Disturbance Zones--For all pile driving and removal activities, a 
disturbance zone would be established. Disturbance zones are typically 
defined as the area in which SPLs equal or exceed 160 or 120 dB rms 
(for impact and vibratory pile driving, respectively). Disturbance 
zones provide utility for monitoring conducted for mitigation purposes 
(i.e., shutdown zone monitoring) by establishing monitoring protocols 
for areas adjacent to the shutdown zones. Monitoring of disturbance 
zones enables MMOs to be aware of and communicate the presence of 
marine mammals in the project area but outside the shutdown zone and 
thus prepare for potential shutdowns of activity. However, the primary 
purpose of disturbance zone monitoring is for documenting incidents of 
Level B harassment; disturbance zone monitoring is discussed in greater 
detail later (see Proposed Monitoring and Reporting). Disturbance zones 
would be established with 50 m radius for impact pile driving and 1,000 
m radius for vibratory pile driving; these zones would subsume the 
calculated disturbance zones for harassment from airborne sound.
    Monitoring Protocols--The shutdown and disturbance zones would be 
monitored throughout the time required to drive a pile. If a marine 
mammal is observed within the disturbance zone, a take would be 
recorded and behaviors documented. However, that pile segment would be 
completed without cessation, unless the animal approaches or enters the 
shutdown zone, at which point all pile driving activities would be 
halted. Impact driving would only occur during daylight hours. If the 
shutdown zone is obscured by fog or poor lighting conditions, pile 
driving would not be initiated until the entire shutdown zone is 
visible. Work that has been initiated appropriately in conditions of 
good visibility may continue during poor visibility.

[[Page 32586]]

    The shutdown zone would be monitored for the presence of marine 
mammals before, during, and after any pile driving activity. The 
shutdown zone would be monitored for 30 minutes prior to initiating the 
start of pile driving. If marine mammals are present within the 
shutdown zone prior to pile driving, the start of pile driving would be 
delayed until the animals leave the shutdown zone of their own 
volition, or until 15 minutes elapse without resighting the animal(s). 
The shutdown zone would also be monitored throughout the time required 
to drive a pile. If a marine mammal is observed approaching or entering 
the shutdown zone, piling operations would be discontinued until the 
animal has moved outside of the shutdown zone. Pile driving would 
resume only after the animal is determined to have moved outside the 
shutdown zone by a qualified observer or after 15 minutes have elapsed 
since the last sighting of the animal within the shutdown zone.
    Monitoring would be conducted using binoculars and the naked eye. 
When possible, digital video or still cameras would also be used to 
document the behavior and response of marine mammals to construction 
activities or other disturbances. Each observer would have a radio or 
cell phone for contact with other monitors or work crews. Observers 
would implement shutdown or delay procedures when applicable by calling 
for the shutdown to the hammer operator. A GPS unit or electric range 
finder would be used for determining the observation location and 
distance to marine mammals, boats, and construction equipment.
    Monitoring would be conducted by qualified observers. In order to 
be considered qualified, observers must meet the following criteria:
     Visual acuity in both eyes (correction is permissible) 
sufficient for discernment of moving targets at the water's surface 
with ability to estimate target size and distance; use of binoculars 
may be necessary to correctly identify the target.
     Advanced education in biological science, wildlife 
management, mammalogy, or related fields (bachelor's degree or higher 
is required).
     Experience and ability to conduct field observations and 
collect data according to assigned protocols (this may include academic 
experience).
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors.
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations.
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates and times when in-water construction 
activities were suspended to avoid potential incidental injury from 
construction sound of marine mammals observed within a defined shutdown 
zone; and marine mammal behavior.
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
Ramp-Up
    The objective of a ramp-up is to alert any animals close to the 
activity and allow them time to move away, which would expose fewer 
animals to loud sounds, including both underwater and above water 
sound. This procedure also ensures that any marine mammals missed 
during shutdown zone monitoring would move away from the activity and 
not be injured. The following ramp-up procedures would be used for in-
water pile installation:
     A ramp-up technique would be used at the beginning of each 
day's in-water pile driving activities or if pile driving has ceased 
for more than 30 minutes.
     If a vibratory driver is used, contractors would be 
required to initiate sound from vibratory hammers for 15 seconds at 
reduced energy followed by a 30-second waiting period. The procedure 
would be repeated two additional times before full energy may be 
achieved.
     For impact driving, contractors would be required to 
conduct soft start if the technique is feasible given the hammer type. 
Soft start would be conducted to provide an initial set of strikes from 
the impact hammer at reduced energy, followed by a 30-second waiting 
period, then two subsequent sets. The reduced energy of an individual 
hammer cannot be quantified because they vary by individual drivers. 
Also, the number of strikes would vary at reduced energy because 
raising the hammer at less than full power and then releasing it 
results in the hammer ``bouncing'' as it strikes the pile, resulting in 
multiple `strikes'.

Helicopter Operations and Fireworks Displays

    Approved flight patterns for AC34 contracted and race-affiliated 
helicopters would be detailed in the Water and Air Traffic Plan. The 
project sponsors would be responsible for coordinating with the FAA to 
ensure compliance with flight regulations and to enforce the flight 
restrictions identified in the Plan to protect marine mammals. 
Helicopters would descend/ascend vertically for landing and take-off at 
the helipad on Treasure Island. Helicopters would not skim the surface 
of water (i.e., flight no lower than 100 ft) during the race events nor 
during landing and takeoff operations. In addition, race-related 
helicopters would maintain a buffer of at least 1,000 ft (vertically 
and horizontally) around Alcatraz Island and Crissy Beach Wildlife 
Protection Area, would avoid direct overflights of the Pier 39 haul-
out, and would maintain the restriction on flight below 100 ft in the 
vicinity of Pier 39 where sea lions are known to haul out.
    Any fireworks displays would be limited in terms of frequency and 
location as necessary to protect marine mammals. There would be no more 
than four events, two up to 30 minutes and two up to 45 minutes in 
duration in 2013. The fireworks barge would be in a similar location to 
and of the same noise intensity as the annual 4th of July fireworks 
display conducted by the City of San Francisco. These fireworks 
displays would be regulated through the USCG Marine Event Permit 
process.
    NMFS has carefully evaluated the applicant's mitigation measures as 
proposed and considered their effectiveness in past implementation to 
preliminarily determine whether they are likely to effect the least 
practicable adverse impact on the affected marine mammal species and 
stocks and their habitat. Our evaluation of potential measures includes 
consideration of the following factors in relation to one another: (1) 
The manner in which, and the degree to which, the successful 
implementation of the measure is expected to minimize adverse impacts 
to marine mammals, (2) the proven or likely efficacy of the specific 
measure to minimize adverse impacts as planned; (3) the practicability 
of the measure for applicant implementation, including consideration of 
personnel safety, and practicality of implementation.
    Injury, serious injury, or mortality to marine mammals is extremely 
unlikely to result from the proposed activities even in the absence of 
any mitigation measures. However, in cooperation with the applicants, 
we have proposed the described mitigation measures to reduce even 
further the probability of such events occurring and to reduce the 
number of potential behavioral harassments to the level of least

[[Page 32587]]

practicable impact. NMFS has preliminarily determined that the proposed 
mitigation measures provide the means of effecting the least 
practicable adverse impacts on marine mammal species or stocks and 
their habitat.

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 ``requirements pertaining to 
the monitoring and reporting of such taking''. The MMPA implementing 
regulations at 50 CFR 216 indicate that requests for IHAs 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.
    The applicants proposed a marine mammal monitoring plan, which may 
be modified or supplemented based on comments or new information 
received during the public comment period. All methods identified 
herein have been developed through coordination between NMFS and the 
applicants, and are based on the parties' professional judgment 
supported by their collective knowledge of marine mammal behavior, site 
conditions, and proposed project activities. Any modifications to this 
protocol would be coordinated with NMFS. A summary of the plan, as well 
as the proposed reporting requirements, is contained here.
    The intent of the monitoring plan is to:
     Comply with the requirements of the MMPA;
     Avoid injury to marine mammals through visual monitoring 
of identified shutdown zones and shutdown of activities when animals 
enter or approach those zones; and
     To the extent possible, record the number, species, and 
behavior of marine mammals in disturbance zones for proposed 
activities.
    As described previously, monitoring for marine mammals during pile 
driving would be conducted in specific zones established to avoid or 
minimize effects of elevated levels of sound created by the specified 
activities. Shutdown and disturbance zones would correspond to the 
distances described previously in this document.

Visual Monitoring

    The established shutdown and disturbance zones would be monitored 
by qualified marine mammal observers for mitigation purposes, as well 
as to document marine mammal behavior and incidents of Level B 
harassment. Monitoring protocols were described in greater detail under 
Proposed Mitigation. The marine mammal monitoring plan would be 
implemented, requiring collection of sighting data for each marine 
mammal observed during the proposed activities for which monitoring is 
required, including all impact pile driving and a subset of vibratory 
pile driving. Disturbance zones, briefly described previously under 
Proposed Mitigation, are discussed in greater depth here.
    Disturbance Zone Monitoring--Disturbance zones, described 
previously in Proposed Mitigation, are defined as 50 m radius for 
impact pile driving and 1,000 m radius for vibratory pile driving. 
Monitoring of disturbance zones would be implemented as described 
previously in Proposed Mitigation. All impact pile driving would be 
monitored according to described protocols. For vibratory driving, the 
first two days of representative pile driving activity at each specific 
location, when the contractors are mobilizing and starting use of the 
vibratory hammer, would be monitored in order to validate estimates of 
incidental take and to record behavioral reactions, if any, of marine 
mammals present in the vicinity. Additional monitoring, to be decided 
when the schedule of work is provided by the contractor, would be 
conducted as necessary in each specific location such that a minimum of 
one-third of the total pile driving days at each location are 
monitored. These additional days may be scheduled at the discretion of 
the applicant, but shall include any days of heightened activity (if 
they occur) or would be representative of typical levels of activity. 
It is not possible for NMFS to define a ``typical'' day of pile driving 
activity. Should it become apparent that greater than anticipated 
numbers of animals are being harassed, or that animals are displaying 
behavioral reactions of greater than anticipated intensity, we may 
require the applicants to expand the monitoring program.
    We considered but rejected an expanded monitoring plan that would 
require the applicants to conduct monitoring as described but for every 
day of vibratory pile driving. NMFS does not believe that monitoring 
need be conducted at all times during this low-level activity as there 
is no potential for injury, serious injury, or mortality and the 
probability of an animal being physically injured from the equipment is 
extremely low if not discountable. Similar to scientific research 
studies, when correcting for effort, the applicants and NMFS would be 
able to adequately determine the number of animals taken and impacts of 
the project on marine mammals based on the proposed monitoring plan. As 
noted previously, in the event of more intense reactions or greater 
numbers of take than anticipated, the applicants would temporarily stop 
activity and consult with NMFS. However, based on the nature of the 
activity and the local context (i.e., a heavily urbanized area with 
animals that are likely habituated to a loud environment and high 
levels of activity), we do not believe that animals would display 
significant adverse reactions to sound levels above background.
    The monitoring biologists would document all marine mammals 
observed in the monitoring area. Data collection would include a count 
of all marine mammals observed by species, sex, age class, their 
location within or in relation to the zone, and their reaction (if any) 
to construction activities, including direction of movement, and type 
of construction that is occurring, time that pile driving begins and 
ends, any acoustic or visual disturbance, and time of the observation. 
Environmental conditions such as wind speed, wind direction, 
visibility, and temperature would also be recorded. No monitoring would 
be conducted during inclement weather that creates potentially 
hazardous conditions, as determined by the biologist, nor would 
monitoring be conducted when visibility is significantly limited, such 
as during heavy rain or fog. During these times of inclement weather, 
impact pile driving would be halted; these activities would not 
commence until monitoring has started for the day.
    Helicopter Operations and Fireworks Displays--In order to estimate 
levels of take incidental to these activities and to better understand 
pinniped sensitivity to disturbance from overflights and fireworks 
displays, the applicants would conduct monitoring as described here. 
For helicopter operations, at least one monitor would conduct 
observations at the California sea lion haul-out at Pier 39 (the only 
established haul-out within the project area) during a subset of 
helicopter operations days. Monitoring would be conducted for the first 
five days on which helicopter operations occur in order to confirm 
assumptions regarding the degree to which pinnipeds may be disturbed by 
such operations. If pinnipeds are being disturbed by helicopter 
operations to a degree similar to that assumed here (see Estimated Take 
by Incidental Harassment), the applicants shall

[[Page 32588]]

monitor on additional days, determined by the applicants and 
contractors, totaling at least one-third of total helicopter operations 
days. If pinnipeds at Pier 39 are not being disturbed, or are being 
disturbed to a much lesser degree than what is assumed here, the 
applicants may cease monitoring after the initial five days.
    For fireworks displays, the applicants would conduct a pre- and 
post-event census of marine mammals within the acute fireworks impact 
area (the area where sound, light, and debris effects may have direct 
impacts on marine organisms and habitats) and would also monitor the 
California sea lion haul-out at Pier 39. The pre-event census, 
conducted in order to estimate the number of marine mammals that may be 
harassed by displays, would occur as close to the actual display time 
as possible, would be conducted for no less than 30 minutes, and would 
describe all observed marine mammals. However, only hauled-out 
pinnipeds observed in the area during the pre-event census, if any, 
would be assumed to be incidentally harassed by the display. Post-event 
monitoring in the acute fireworks impact area, to occur no later than 
the morning following the display and for no less than 30 minutes, 
would be conducted to record injured or dead marine mammals, if any.
    During monitoring at the Pier 39 haul-out--during helicopter 
overflights or fireworks displays--monitors would note pinniped 
disturbance according to a three-point scale indicating severity of 
behavioral reaction, as shown in Table 3. The time, source, and 
duration of the disturbance, as well as an estimated distance between 
the source and haul-out, would be recorded. Only responses falling into 
Levels 2 and 3 would be considered as harassment under the MMPA, under 
the terms of this proposed IHA.

                Table 3--Pinniped Response to Disturbance
------------------------------------------------------------------------
          Level                Type of response           Definition
------------------------------------------------------------------------
1........................  Alert...................  Head orientation in
                                                      response to
                                                      disturbance. This
                                                      may include
                                                      turning head
                                                      towards the
                                                      disturbance,
                                                      craning head and
                                                      neck while holding
                                                      the body rigid in
                                                      a u-shaped
                                                      position, or
                                                      changing from a
                                                      lying to a sitting
                                                      position. May
                                                      include slight
                                                      movement of less
                                                      than 1 m.
2........................  Movement................  Movements in
                                                      response to or
                                                      away from
                                                      disturbance,
                                                      typically over
                                                      short distances (1-
                                                      3 m).
3........................  Flight..................  All flushes to the
                                                      water as well as
                                                      lengthier retreats
                                                      (>3 m).
------------------------------------------------------------------------

    All monitoring personnel must have appropriate qualifications as 
identified previously, with qualifications to be certified by ACEA and 
the Port (see Proposed Mitigation). These qualifications include 
education and experience identifying marine mammals that may occur in 
the Bay and the ability to understand and document marine mammal 
behavior. All monitoring personnel would meet at least once for a 
training session sponsored by the applicants. Topics would include: 
implementation of the protocol, identification of marine mammals, and 
reporting requirements.
    All monitoring personnel would be provided a copy of the IHA. 
Monitoring personnel must read and understand the contents of the IHA 
as they relate to coordination, communication, and identification and 
reporting incidental harassment of marine mammals.

Reporting

    The applicants are required to submit a report on all activities 
and marine mammal monitoring results to the Office of Protected 
Resources, NMFS, and the Southwest Regional Administrator, NMFS, 90 
days prior to the desired date of validity for any subsequent IHA, or 
within 90 days of the expiration of the IHA, whichever comes first. A 
final report would be prepared and submitted to NMFS within 30 days 
following receipt of NMFS' comments on the draft report. The report 
would provide descriptions of any observed behavioral responses to the 
proposed activities by marine mammals, including marine mammal 
observations pre-, during-, and post-activity for pile driving 
monitoring. At a minimum, the report would include:
     Specifics of the activity: Date, time, and location; 
observation conditions (e.g., sea state, tide state, percent cover, 
visibility); pile driving activity specifications (e.g., size and type 
of piles, hammer specifications and sound attenuation device 
specifications);
     Discussion of incidental take, including (1) records of 
all observed incidental take events; (2) for vibratory pile driving, 
the total estimated amount of incidental take based on extrapolation of 
observed take; and (3) estimates of take for helicopter operations and 
fireworks displays.
     Description of observed marine mammal behavior, including 
correlations of observed behavior to activity, including distance to 
pile being driven or other source of disturbance; and discussion of 
sensitivity of hauled-out pinnipeds to helicopter overflights and/or 
fireworks displays as described previously.
     Discussion of mitigation, including description of any 
actions performed to minimize impacts to marine mammals; and times when 
pile driving is stopped or delayed due to presence of marine mammals 
within shutdown zones and time when pile driving resumes.
     Any recommendations for improving efficacy and efficiency 
of monitoring and/or mitigation.

Estimated Take by Incidental Harassment

    ACEA and the Port have requested, and we are proposing, 
authorization to take harbor seals, California sea lions, northern 
elephant seals, and harbor porpoises, by Level B harassment only, 
incidental to the proposed activities. Pile driving activities are 
expected to incidentally harass marine mammals through the introduction 
of underwater and/or airborne sound to the environment, while 
helicopter operations and fireworks displays have the potential to 
harass pinnipeds through some combination of acoustic and visual 
stimuli. Based on the nature of the activities and the mitigation 
measures proposed for implementation, no take by injury, serious 
injury, or mortality is anticipated or proposed for authorization. 
Estimates of the number of animals that may be harassed by the proposed 
activities is based upon the number of animals believed to potentially 
be present within relevant areas at the time a given activity is 
conducted. Tables 4 details the total number of estimated takes. In 
summary, we propose to authorize the incidental take, by Level B 
harassment only, of 14,063 California sea lions, 686 harbor seals, 63 
harbor porpoises, and two elephant seals. These take events would 
likely represent multiple takes of individuals, rather than each event 
being of a new individual.

[[Page 32589]]



                                       Table 4--Incidental Take Estimates
----------------------------------------------------------------------------------------------------------------
                                                                                 Helicopter         Fireworks
              Species                                         Pile driving       operations         displays
----------------------------------------------------------------------------------------------------------------
California sea lion................  Individuals/day......                 1               250               250
                                     Total  days.                63                52                 4
                                     Total take estimate..                63            13,000             1,000
Harbor seal........................  Individuals/day......                 2                10                10
                                     Total  days.                63                52                 4
                                     Total take estimate..               126               520                40
Harbor porpoise....................  Individuals/day......                 1               n/a               n/a
                                     Total  days.                63               n/a               n/a
                                     Total take estimate..                63               n/a               n/a
                                                           -----------------------------------------------------
Elephant seal......................  .....................  Total request of two individuals for all activities.
----------------------------------------------------------------------------------------------------------------

Pile Driving

    California sea lions and harbor seals may use the waters adjacent 
to the San Francisco waterfront for foraging or for daily movement 
between foraging and haul out locations, and observations have been 
made at various locations along the San Francisco waterfront. The 
California sea lion haul-out at Pier 39 is approximately 800-1,000 m 
from the nearest vibratory driving location--although sound would be 
attenuated by at least three major piers between, as well as the 
curvature of the waterfront shoreline--and is approximately 1.6 km from 
Pier 19, where impact pile driving would occur. As previously 
described, the nearest known haul out site for harbor seals is at YBI. 
Vibratory driving locations range approximately 2.4-6.8 km from the 
haul-out, while Pier 19, where impact driving of timber piles would 
occur, is more than 3.2 km distant from the haul-out. Proposed 
fireworks displays would be approximately 1.6-3.2 km from Pier 39 and 
3.2-4.8 km from YBI, depending on the final selected location. No 
proposed activities would be expected to affect animals at the YBI 
haul-out. While it is possible that harbor porpoises could occur in the 
vicinity of the waterfront, sightings greater than approximately 800 m 
inside the Golden Gate Bridge are infrequent (NMFS, 2009) and the 
harbor porpoise is considered uncommon in the vicinity of the San 
Francisco waterfront.
    The most comprehensive monitoring data available was collected by 
Caltrans for the SFOBB project; these data represent the best available 
information for approximating local abundance of these species. The 
SFOBB monitoring site was located in the vicinity of the YBI haul-out, 
whereas most of the sites where construction or race activities would 
occur are in areas of high commercial shipping and boat activity. 
Therefore, SFOBB monitoring data may be expected to provide 
conservative estimates of marine mammal abundance. More recent 
monitoring was conducted during construction associated with the 
Exploratorium, located at Piers 15 and 17 at the San Francisco 
waterfront. During vibratory pile driving only, monitoring was 
conducted on 25 days from January 10-July 29, 2011, to a distance of 
approximately 2,000 m from the pile driving location. On those 25 days, 
the only species observed were the California sea lion and the harbor 
seal. Harbor seals were observed on 9 of 25 days, while California sea 
lions were observed on 8 of 25 days. Sightings data provide rates of 
0.52 and 0.68 animals observed per monitoring day for harbor seals and 
California sea lions, respectively.
    During monitoring of the SFOBB project over 22 days, abundance 
estimates of 1.5 seals per day and 0.09 sea lions per day were 
recorded. Due to the relative tranquility of YBI and the presence of a 
harbor seal haul-out, the estimate for harbor seals is likely higher 
than would be found for the San Francisco waterfront. However, as 
confirmed by information from the Exploratorium monitoring effort, the 
estimate for California sea lions is likely lower, given that greater 
numbers of that species may be encountered transiting to and from the 
Pier 39 haul-out.
    The applicants propose conservative estimates of two harbor seals 
per day--a slight increase from the SFOBB data--and one California sea 
lion per day, a slight increase from the Exploratorium observations. 
The Caltrans SFOBB monitoring reported one observed harbor porpoise in 
the vicinity of YBI. This is the only available information for harbor 
porpoise and provides an extremely conservative estimate of one harbor 
porpoise per day of activity. Based on estimated pile driving 
production rates, a maximum of 63 days is anticipated for pile driving 
under this proposed IHA.

Helicopter Operations and Fireworks Displays

    Incidental take resulting from helicopter overflights and/or 
fireworks displays would likely be limited to California sea lions and 
harbor seals occurring within the immediate vicinity of a helicopter 
flight patterns or fireworks displays. Specifically, California sea 
lions present at Pier 39 would likely be subject to incidental 
harassment, although there is the potential for harbor seals to be 
hauled-out within range of stimuli that may cause harassment.
    Estimates of the number of California sea lions that could be 
harassed by helicopter operations and/or fireworks displays are based 
on information from the Pier 39 haul-out. California sea lion usage of 
Pier 39 is a relatively recent phenomenon. The first individuals were 
observed during the winter of 1989-90, however, by the next year the 
numbers reached an average 500 per day (Goals Project, 2000), with a 
maximum recorded observation of approximately 800 individuals. Since 
the early 1990s, peak numbers during winter have declined and now 
average about 200-300 animals per day. In order to estimate incidental 
take, a conservative estimate of 500 animals present per day was 
considered. Observations of pinniped response to the presence of humans 
on foot in the Channel Islands indicated that the proportion of 
California sea lions that are behaviorally harassed is approximately 
fifty percent (77 FR 12246), although this is likely conservative, 
given that the animals at Pier 39 are more habituated to stimuli than 
those in more remote locations.
    Estimates of the number of harbor seal that may be present during 
helicopter operations and/or fireworks displays are based on local 
observations reported by the applicants--no other upon which to base 
the estimate is known to us or to the applicants. Anecdotal information 
from monitoring of fleet week, National

[[Page 32590]]

Park Service staff observations, and local sailors reported 
observations of anywhere from 10-15 seals per day while out on the 
water. Therefore, in an extremely conservative estimation, we assume 
that ten animals per day may be hauled-out in locations along the 
waterfront and that all animals would be harassed. The previously 
mentioned Channel Islands observations indicate that approximately 75 
percent of animals are harassed by a given stimuli, but it is likely 
that all animals would flush in this context.

Elephant Seals

    As stated previously, elephant seals breed between December and 
March and have been rarely sighted in the Bay. However, regular, if 
infrequent, sightings of juveniles have been made in recent years at 
Crissy Field beach. Therefore, it is possible that an elephant seal 
could occur within areas that are ensonified above levels that NMFS 
considers to result in Level B harassment. Although possible, it is 
unlikely that elephant seals would be harassed; however, in order to be 
precautionary the applicants have requested authorization for 
incidental take of two elephant seals over the life of the proposed IHA 
and we propose to authorize that take. There is no information upon 
which to base a quantitative estimate of potential take; therefore, 
take is estimated on the basis of the few individuals observed at 
Crissy Field beach.
    It is not anticipated that elephant seals would be harassed by 
helicopter operations and/or fireworks displays because (1) elephant 
seals have been observed, during the aforementioned Channel Island 
monitoring, to display behavioral reactions to potentially harassing 
stimuli less than one percent of the time; (2) Crissy Field beach is 
over 4 km distant from the nearest potential fireworks display 
location; and (3) helicopters would avoid Crissy Field beach by 1,000 
ft in response to concerns about sensitive avian species.

Negligible Impact and Small Numbers Analysis and Determination

    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.'' In making a negligible impact determination, 
NMFS considers a variety of factors, including but not limited to: (1) 
The number of anticipated mortalities (if any); (2) the number and 
nature of anticipated injuries (if any); (3) the number, nature, 
intensity, and duration of Level B harassment; and (4) the context in 
which the take occurs.
    Although the proposed activities may harass marine mammals present 
in the action area, impacts are largely occurring to a localized group 
of animals (i.e., the California sea lions present in the vicinity of 
Pier 39 and harbor seals from YBI that may be present at the San 
Francisco waterfront). Further, any incidents of harassment would be 
occurring to animals that are habituated to a high level of surrounding 
human activity, including both urban and industrial activity, and to an 
already loud environment. Monitoring associated with the Exploratorium 
project resulted in no observations of discernible reactions to 
vibratory pile driving or any other work activity, although animals 
were observed as close as 12 m from pile driving. No avoidance behavior 
was observed, including even basic reactions such as head alerts. Both 
sea lions and harbor seals appeared to use the waterfront for 
travelling along a rough north-south course. Travel was typically slow, 
although some fast traveling (indicating by porpoising) by sea lions 
was noted. A few individuals of both species were also observed resting 
at the surface. Frequent commercial and recreational vessel traffic was 
consistently observed on all monitoring days, and observed animals were 
reported as appearing habituated to such traffic.
    The proposed number of animals taken for each species can be 
considered small relative to the population size. There are an 
estimated 34,233 harbor seals in the California stock, 238,000 
California sea lions, 9,189 harbor porpoises, and 124,000 northern 
elephant seals in the California breeding population. Based on the best 
available information, NMFS is proposing to authorize take, by Level B 
harassment only, of 14,063 California sea lions, 686 harbor seals, 63 
harbor porpoises, and two northern elephant seals, representing 5.9, 
2.0, 0.7, and 0.002 percent of the populations, respectively. However, 
this represents an overestimate of the number of individuals harassed 
over the duration of the proposed IHA, because these totals represent 
much smaller numbers of individuals that may be harassed multiple 
times. No stocks known from the action area are listed as threatened or 
endangered under the ESA or determined to be depleted or considered 
strategic under the MMPA. Recent data suggests that harbor seal 
populations have reached carrying capacity, populations of California 
sea lions and northern elephant seals in California are also considered 
healthy, and recent information suggests that the harbor porpoise may 
be expanding its range on the west coast. No injury, serious injury, or 
mortality is anticipated, nor is the proposed action likely to result 
in long-term impacts such as permanent abandonment of the Pier 39 haul-
out or a permanent reduction in presence in San Francisco Bay. No 
impacts are expected at the population or stock level.
    Based on the foregoing analysis, behavioral disturbance to marine 
mammals in the Bay would be of low intensity and limited duration. To 
ensure minimal disturbance, the applicants would implement the 
mitigation measures described previously, which we have preliminarily 
determined would serve as the means for effecting the least practicable 
adverse impact on the relevant marine mammal stocks or populations and 
their habitat. We preliminarily find that the proposed activities would 
result in the incidental take of small numbers of marine mammals, and 
that the requested number of takes would have no more than a negligible 
impact on the affected species and stocks.

Impact on Availability of Affected Species for Taking for Subsistence 
Uses

    There are no relevant subsistence uses of marine mammals implicated 
by this action.

Endangered Species Act (ESA)

    There are no ESA-listed marine mammals found in the action area; 
therefore, no consultation under the ESA is required.

National Environmental Policy Act (NEPA)

    In compliance with the National Environmental Policy Act of 1969 
(42 U.S.C. 4321 et seq.), as implemented by the regulations published 
by the Council on Environmental Quality (40 CFR parts 1500-1508), and 
NOAA Administrative Order 216-6, we are preparing an Environmental 
Assessment (EA) to consider the direct, indirect and cumulative effects 
to the human environment resulting from issuance of a proposed IHA to 
ACEA and the Port for the specified activities.

Proposed Authorization

    As a result of these preliminary determinations, we propose to 
authorize the take of marine mammals incidental to the proposed 
activities, provided the previously mentioned mitigation,

[[Page 32591]]

monitoring, and reporting requirements are incorporated.

    Dated: May 25, 2012.
Frederick C. Sutter III,
Acting Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2012-13327 Filed 5-31-12; 8:45 am]
BILLING CODE 3510-22-P