[Federal Register Volume 76, Number 207 (Wednesday, October 26, 2011)]
[Notices]
[Pages 66274-66281]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-27739]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XA650
Small Takes of Marine Mammals Incidental to Specified Activities;
Pier 36/Brannan Street Wharf Project in the 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 a complete and adequate application from the
United States Army Corps of Engineers, San Francisco District (USACE),
on behalf of the Port of San Francisco (Port), for an Incidental
Harassment Authorization (IHA) to take marine mammals, by harassment,
incidental to pile driving during construction of the Brannan Street
Wharf. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is
proposing to issue an IHA to incidentally harass, by Level B
harassment, four species of marine mammals during the specified
activity within a specific geographic region and is requesting comments
on its proposal.
DATES: Comments and information must be received no later than November
25, 2011.
ADDRESSES: Comments on the application and this proposal should be
addressed to Michael Payne, Chief, Permits, Conservation and Education
Division, Office of Protected Resources, National Marine Fisheries
Service, 1315 East-West Highway, Silver Spring, MD 20910-3225. The
mailbox address for
[[Page 66275]]
providing e-mail comments is [email protected]. NMFS is not
responsible for e-mail comments sent to addresses other than the one
provided here. Comments sent via e-mail, including all attachments,
must not exceed a 10-megabyte file size.
Instructions: All comments received are a part of the public record
and will generally be posted to http://www.nmfs.noaa.gov/pr/permits/incidental.htm without change. All Personal Identifying Information
(for example, name, address, etc.) voluntarily submitted by the
commenter may be publicly accessible. Do not submit Confidential
Business Information or otherwise sensitive or protected information.
A copy of the application 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. Documents cited in this
notice may also be viewed, by appointment, during regular business
hours, at the aforementioned address.
FOR FURTHER INFORMATION CONTACT: Michelle Magliocca, Office of
Protected Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Background
Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)
direct the Secretary of Commerce to allow, upon request, the
incidental, but not intentional, taking of small numbers of marine
mammals by United States citizens who engage in a specified activity
(other than commercial fishing) within a specific geographical region
if certain findings are made and either regulations are issued or, if
the taking is limited to harassment, a notice of a proposed
authorization is provided to the public for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s), will not have an unmitigable adverse impact on the
availability of the species or stock(s) for subsistence uses (where
relevant), and if the permissible methods of taking and requirements
pertaining to the mitigation, monitoring and reporting of such takings
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103
as `` * * * an impact resulting from the specified activity that cannot
be reasonably expected to, and is not reasonably likely to, adversely
affect the species or stock through effects on annual rates of
recruitment or survival.''
Section 101(a)(5)(D) of the MMPA established an expedited process
by which citizens of the United States can apply for an authorization
to incidentally take small numbers of marine mammals by harassment.
Section 101(a)(5)(D) further established 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.
Except with respect to certain activities not pertinent here, the
MMPA defines ``harassment'' as:
any act of pursuit, torment, or annoyance which (i) has the
potential to injure a marine mammal or marine mammal stock in the
wild [Level A harassment]; or (ii) has the potential to disturb a
marine mammal or marine mammal stock in the wild by causing
disruption of behavioral patterns, including, but not limited to,
migration, breathing, nursing, breeding, feeding, or sheltering
[Level B harassment].
Summary of Request
On May 6, 2011, NMFS received an application from the USACE, on
behalf of the Port, requesting an IHA for the take, by Level B
harassment, of small numbers of Pacific harbor seals (Phoca vitulina),
California sea lions (Zalophus californianus), gray whales
(Eschrichtius robustus), and Pacific harbor porpoises (Phocoena
phocoena) incidental to pile driving activities during construction of
the Brannan Street Wharf in San Francisco, California. Upon receipt of
additional information and a revised application, NMFS determined the
application complete and adequate on August 7, 2011.
The Port proposes to construct a pile-supported park that would be
known as the ``Brannan Street Wharf'' and would replace the existing
Pier 36 and provide recreational space for the public. The proposed
project would require installation of 261 steel and concrete piles and
57,000 square feet (ft\2\) of new decking. Because elevated sound
levels from pile driving have the potential to result in marine mammal
harassment, NMFS is proposing to issue an IHA for take incidental to
the specified activity.
Description of the Specified Activity
The Port proposes to replace the existing Pier 36 with a pile-
supported park along the San Francisco waterfront. The proposed park
would provide a new open space for the purpose of public recreation and
include the following: a 26,000 ft\2\ raised lawn area; a waterside
walkway with seating, shelters, and picnic tables; and a 2,000 ft\2\
small craft float and accessible gangway for launching non-motorized
recreational vessels.
To construct the 57,000 ft\2\ open space, the existing overwater
Pier 36 structures would be demolished, the existing supporting
caissons would be removed, and 261 steel and concrete piles would be
installed at the site using vibratory and impact pile driving.
Demolition and removal of the caissons is not expected to harass marine
mammals because these activities would occur above water and the height
of the existing Pier 36 decking prevents marine mammals from hauling
out. (The nearest haul-out site is over 3.2 kilometers (km) (2 miles
[mi]) away at Yerba Buena Island.) The caissons would be removed using
a barge mounted excavator and this method is not expected to generate
sound at pressures outside of the ambient noise conditions.
Installation of the new cast-in-place concrete decking would also occur
above water. Installation of the 261 steel and concrete piles, however,
would require in-water pile driving that could produce high-intensity
sound and has the potential to harass marine mammals. A breakdown of
proposed pile size and type is shown in Table 1.
Table 1--Summary of Pile Types and Pile Driving Activity
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Max piles per
Pile type Total piles Pile driver day
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24-inch octagonal concrete.................. 141 Impact........................ 8
24-inch steel shell......................... 116 Vibratory and impact.......... 5
36-inch steel shell......................... 4 Vibratory and impact.......... 4
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[[Page 66276]]
Of the 261 piles, about 141 would be 24-inch (in) octagonal
concrete piles driven in water depths of 2 to 15 ft mean lower low
water. These piles would be driven to a depth of 60 ft below the
mudline elevation--like all the other piles--using an impact hammer.
Each pile may take 20 minutes to drive into the substrate, which
consists of about 20 ft of bay mud underlain by a sand mixture. Up to
800 blows from an impact hammer would be necessary for each concrete
pile.
Of the 261 piles, about 116 would be 24-in steel shell piles driven
in water depths of zero to 6 ft mean lower low water. These piles would
be installed nearest the shoreline as pier support piles and would be
used in place of concrete piles due to the presence of rock dike
material along the shore. Installation would include about eight
minutes of vibratory pile driving, followed by up to 300 blows from an
impact hammer.
The remaining 4 piles would be 36-in steel shell piles used for the
new floating dock. These piles would be installed in water depths of 10
to 15 ft mean lower low water. Each pile installation would begin with
five to 15 minutes of vibratory pile driving, followed by about 600
blows from an impact hammer.
Only one pile type is expected to be installed on any given day.
Conservatively assuming the maximum vibratory time and number of impact
blows required for each pile, a total of 988 minutes of vibratory
driving and 150,000 impact blows would be necessary over the 12-month
duration of the project. All vibratory pile driving would use a
standard frequency hammer similar to an APE 150, which produces up to
1,800 vibrations per minute. All impact pile driving would use a DelMag
D46-32 diesel impact hammer, which produces about 122,000 foot-pounds
maximum energy blow at 1.5 seconds per blow on average. A bubble
curtain would be used as a sound attenuation device during impact pile
driving for the 24-in and 36-in steel shell piles.
Region of Activity
The proposed activity would occur in the San Francisco Bay at Pier
36, four blocks south of the San Francisco Oakland Bay Bridge. More
specifically, this area is located between Pier 30-32 and Pier 38,
directly adjacent to the east side of the Embarcadero and within the
South of Market district of San Francisco. San Francisco Bay and the
adjacent Sacramento-San Joaquin Delta make up one of the largest
estuarine systems on the continent. The Bay has undergone extensive
industrialization, but remains an important environment for healthy
marine mammal populations year round. The area surrounding the proposed
activity is an intertidal landscape with heavy industrial use and boat
traffic.
Dates of Activity
Wharf and pier demolition--which is not expected to harass marine
mammals--may begin in January 2012 and last for five months. The new
wharf construction, including pile driving, is scheduled to begin in
May 2012 and end 13 months later; however, pile driving is expected to
be complete by December 2012.
Sound Propagation
For background, sound is a mechanical disturbance consisting of
minute vibrations that travel through a medium, such as air or water,
and is generally characterized by several variables. Frequency
describes the sound's pitch and is measured in hertz (Hz) or kilohertz
(kHz), while sound level describes the sound's loudness and is measured
in decibels (dB). Sound level increases or decreases exponentially with
each dB of change. For example, 10 dB yields a sound level 10 times
more intense than 1 dB, while a 20 dB level equates to 100 times more
intense, and a 30 dB level is 1,000 times more intense. Sound levels
are compared to a reference sound pressure (micro-Pascal) to identify
the medium. For air and water, these reference pressures are ``re: 20
[micro]Pa'' and ``re: 1 [micro]Pa,'' respectively. 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 rather than by peak pressures.
A review of numerous pile driving projects with comparable water
depth and substrate conditions was conducted to identify source sound
level data and estimate potential sound levels for pile driving
activities around Pier 36. In their calculations, the Port
conservatively assumed that the use of a bubble curtain for steel shell
piles would reduce sound levels by 5 dB RMS. A conservative attenuation
factor of 16 dB RMS (about 5 dB RMS per doubling of distance) was also
assumed in the Port's analysis; sound attenuation would likely be
greater than 16 dB RMS for such shallow water pile driving (CalTrans,
2009). Pile driving at Pier 36 is expected to occur in water depths of
zero to 15 feet. Maximum sound pressure levels for pile driving
activities are shown in Table 2.
Table 2--Measured Unattenuated Sound Pressure Levels in the Near Field (10 m) During Pile Driving in San
Francisco Bay (Caltrans, 2009)
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Pile type Attenuation device Sound level (impact) Sound level (vibratory)
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24-in octagonal concrete............ None................... 170 dB n/a
24-in steel shell................... Bubble curtain......... 190 dB 165 dB
36-in steel shell................... Bubble curtain......... 190 dB 175 dB
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Description of Marine Mammals in the Area of the Specified Activity
Marine mammals with confirmed occurrences in San Francisco Bay are
the Pacific harbor seal, California sea lion, gray whale, harbor
porpoise, humpback whale (Megaptera noveangliae), and sea otter
(Enhydra lutris). However, humpback whales are considered extremely
rare in San Francisco Bay and are highly unlikely to be present in the
project vicinity during pile driving. Sea otters are managed by the
United States Fish and Wildlife Service. Therefore, these two species
are not discussed further.
[[Page 66277]]
Pacific Harbor Seals
Pacific harbor seals reside in coastal and estuarine waters off
Baja, California, north to British Columbia, west through the Gulf of
Alaska, and in the Bering Sea. The most recent harbor seal counts
estimate the California stock of Pacific harbor seals at 34,233
individuals. The population appears to be stabilizing at what may be
their carrying capacity, and human-caused mortality is declining (NMFS,
2005). The California stock of Pacific harbor seals is not listed under
the Endangered Species Act (ESA) nor considered depleted under the
MMPA.
In California, approximately 400-500 harbor seal haul-out sites are
widely distributed along the mainland and offshore islands, including
intertidal sandbars, rocky shores, and beaches. The northside of Yerba
Buena Island is the closest haul-out to the project location,
approximately 3.2 km (2 mi) from Pier 36. Although harbor seals use
this haul-out year-round, Yerba Buena Island is not considered a
pupping site. In California, breeding occurs from March to May, and
pupping between April and May depending on local populations. Harbor
seals around Pier 36 would likely be transiting to and from their
closest haul-out (Yerba Buena Island) or opportunistically foraging.
Herring spawning events could result in harbor seals congregating and
approaching the action area sporadically in an unpredictable manner
(pers. comm., M. DeAngelis to M. Magliocca).
Pinnipeds produce a wide range of social signals, most occurring at
relatively low frequencies (Southall et al., 2007), suggesting that
hearing is keenest at these frequencies. Pinnipeds communicate
acoustically both on land and underwater, but have different hearing
capabilities dependent upon the medium (air or water). Based on
numerous studies, as summarized in Southall et al. (2007), pinnipeds
are more sensitive to a broader range of sound frequencies underwater
than in air. Underwater, pinnipeds can hear frequencies from 75 Hz to
75 kHz. In air, pinnipeds can hear frequencies from 75 Hz to 30 kHz
(Southall et al., 2007).
California Sea Lions
California sea lions reside throughout the Eastern North Pacific
Ocean in shallow coastal and estuarine waters, ranging from Central
Mexico to British Columbia, Canada. Their primary breeding range
extends from Central Mexico to the Channel Islands in Southern
California. The United States stock abundance is estimated at 238,000
sea lions (NMFS, 2007). This stock is approaching carrying capacity and
is reaching ``optimum sustainable population'' limits, as defined by
the MMPA. California sea lions are not listed under the ESA nor
considered depleted under the MMPA.
Sandy beaches are preferred habitat for haul-out sites, but marina
docks, jetties, and buoys are often used in California for resting,
breeding, and molting. In San Francisco Bay, sea lions have been
observed at Angel Island and are known to haul out on buoys and
floating docks near Pier 39, which is about 3.6 km (2.2 mi) north of
the proposed project site. Sea lions usually appear at Pier 39 after
returning from the Channel Islands at the beginning of August. No other
sea lion haul-out sites have been identified in the Bay and no pupping
has been observed in the Bay. Sea lions observed within this area may
be transiting to and from nearby piers or opportunistically foraging.
Pinnipeds produce a wide range of social signals, most occurring at
relatively low frequencies (Southall et al., 2007), suggesting that
hearing is keenest at these frequencies. Pinnipeds communicate
acoustically both on land and underwater, but have different hearing
capabilities dependent upon the medium (air or water). Based on
numerous studies, as summarized in Southall et al. (2007), pinnipeds
are more sensitive to a broader range of sound frequencies underwater
than in air. Underwater, pinnipeds can hear frequencies from 75 Hz to
75 kHz. In air, pinnipeds can hear frequencies from 75 Hz to 30 kHz
(Southall et al., 2007).
Harbor Porpoises
Harbor porpoises have a wide and discontinuous range that includes
the North Atlantic and North Pacific. In the Eastern North Pacific,
harbor porpoises are found in coastal and inland waters from Point
Conception, California to Alaska. Harbor porpoises in United States
waters are divided into 10 stocks, based on genetics, movement
patterns, and management. Any harbor porpoises encountered during the
proposed project would likely be part of the San Francisco-Russian
River stock, which has an estimated abundance of 9,189 animals. This
stock appeared to be stable or declining between 1988 and 1991 and has
steadily increased since 1993, although not significantly. Harbor
porpoises are not commonly sighted in San Francisco Bay, but have been
observed traveling in small pods of two to three animals on occasion
(pers. comm., M. DeAngelis to M. Magliocca) and sightings have been
reported by the California Department of Transportation. The closest
sightings to Pier 36 have been near Yerba Buena Island, about 3.2 km (2
mi) away. They may occur in the action area during a time when they
could be affected by pile driving activities; however, their presence
in the vicinity is rare. Harbor porpoises in California are not listed
under the ESA nor considered depleted under the MMPA.
Cetaceans are divided into three functional hearing groups: low-
frequency, mid-frequency, and high-frequency. Harbor porpoises are
considered high-frequency cetaceans and their estimated auditory
bandwidth (lower to upper frequency hearing cut-off) ranges from 200 Hz
to 180 kHz.
Gray Whales
Gray whales are large mysticetes, or baleen whales, found mainly in
shallow coastal waters of the North Pacific Ocean. Two isolated
geographic distributions of gray whales exist: the Eastern North
Pacific stock and the Western North Pacific stock. The Eastern North
Pacific stock migrates as far south as Baja, California for breeding
and calving in the winter and as far north as the Bering and Chukchi
Seas for summer feeding. During migration, gray whales occasionally
enter rivers and bays in very low numbers. They could potentially be in
the proposed project area during pile driving activities. The most
recent 2008 stock assessment report estimated the Eastern North Pacific
stock to be approximately 18,813 individuals with an increasing
population trend over the past several decades. Gray whales were
delisted from the ESA in 1994 and are not considered depleted under the
MMPA.
Gray whales, like other baleen whales, are in the low-frequency
hearing group. There are no empirical data on gray whale hearing;
however, Wartzok and Ketten (1999) suggest that mysticete hearing is
most sensitive at the same frequencies at which they vocalize.
Underwater sounds produced by gray whales range from 20 Hz to 20 kHz
(Richardson et al., 1995).
Potential Effects on Marine Mammals
The proposed action consists of both in-water and above-water
components, but the only activity with the potential to take marine
mammals is pile driving. Elevated in-water sound levels from pile
driving in the proposed project area may temporarily impact marine
mammal behavior. Elevated in-air sound levels are not a concern because
the nearest pinniped haul-out is approximately 3.2 km (2 mi) away.
Marine mammals are continually exposed to many sources of sound. For
example, lightning, rain, sub-sea earthquakes, and animals are
[[Page 66278]]
natural sound sources throughout the marine environment. Marine mammals
produce sounds in various contexts and use sound for various biological
functions including, but not limited to, (1) Social interactions; (2)
foraging; (3) orientation; and (4) predator detection. Interference
with producing or receiving these sounds may result in adverse impacts.
Audible distance or received levels will depend on the sound source,
ambient noise, and the sensitivity of the receptor (Richardson et al.,
1995). Marine mammal reactions to sound may depend on sound frequency,
ambient sound, what the animal is doing, and the animal's distance from
the sound source (Southall et al., 2007).
Hearing Impairment
Marine mammals may experience temporary or permanent hearing
impairment when exposed to loud sounds. Hearing impairment is
classified by temporary threshold shift (TTS) and permanent threshold
shift (PTS). There are no empirical data for when PTS first occurs in
marine mammals; therefore, it must be estimated from when TTS first
occurs and from the rate of TTS growth with increasing exposure levels.
PTS is likely if the animal's hearing threshold is reduced by >=40 dB
of TTS. PTS is considered auditory injury (Southall et al., 2007) and
occurs in a specific frequency range and amount. Irreparable damage to
the inner or outer cochlear hair cells may cause PTS; however, other
mechanisms are also involved, such as exceeding the elastic limits of
certain tissues and membranes in the middle and inner ears and
resultant changes in the chemical composition of the inner ear fluids
(Southall et al., 2007). Due to proposed mitigation measures and source
levels in the proposed project area, NMFS does not expect marine
mammals to be exposed to PTS levels.
Temporary Threshold Shift (TTS)
TTS is the mildest form of hearing impairment that can occur during
exposure to a loud sound (Kryter, 1985). While experiencing TTS, the
hearing threshold rises and a sound must be louder in order to be
heard. TTS can last from minutes or hours to days, occurs in specific
frequency ranges (i.e., an animal might only have a temporary loss of
hearing sensitivity between the frequencies of 1 and 10 kHz), and can
occur to varying degrees (e.g., an animal's hearing sensitivity might
be reduced by 6 dB or by 30 dB). For sound exposures at or somewhat
above the TTS-onset threshold, hearing sensitivity 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. Southall et al. (2007) considers a 6 dB TTS (i.e., baseline
thresholds are elevated by 6 dB) sufficient to be recognized as an
unequivocal deviation and thus a sufficient definition of TTS-onset.
Because it is non-injurious, NMFS considers TTS as Level B harassment
that is mediated by physiological effects on the auditory system;
however, NMFS does not consider onset TTS to be the lowest level at
which Level B harassment may occur.
Southall et al. (2007) summarizes underwater pinniped data from
Kastak et al. (2005), indicating that a tested harbor seal showed a TTS
of around 6 dB when exposed to a non-pulse noise at SPL 152 dB re: 1
[mu]Pa for 25 minutes. In contrast, a tested sea lion exhibited TTS-
onset at 174 dB re: 1 [mu]Pa under the same conditions as the harbor
seal. Data from a single study on underwater pulses found no signs of
TTS-onset in sea lions at exposures up to 183 dB re: 1 [mu]Pa (peak-to-
peak) (Finneran et al., 2003). There is no information on species-
specific TTS for harbor porpoises or gray whales.
Behavioral Effects
There are limited data available on the behavioral effects of non-
pulse noise (for example, vibratory pile driving) on pinnipeds while
underwater; however, field and captive studies to date collectively
suggest that pinnipeds do not react strongly to exposures between 90
and 140 dB re: 1 microPa; no data exist from exposures at higher
levels. Jacobs and Terhune (2002) observed wild harbor seal reactions
to high-frequency acoustic harassment devices around nine sites. Seals
came within 44 m of the active acoustic harassment devices and failed
to demonstrate any behavioral response when received SPLs were
estimated at 120-130 dB. In a captive study (Kastelein, 2006),
scientists subjected a group of seals to non-pulse sounds between 8 and
16 kHz. Exposures between 80 and 107 dB did not induce strong
behavioral responses; however, a single observation from 100 to 110 dB
indicated an avoidance response. The seals returned to baseline
conditions shortly following exposure. Southall et al. (2007) notes
contextual differences between these two studies; the captive animals
were not reinforced with food for remaining in the noise fields,
whereas free-ranging animals may have been more tolerant of exposures
because of motivation to return to a safe location or approach
enclosures holding prey items. Vibratory and impact pile driving may
result in anticipated hydroacoustic levels between 165 and 190 dB root
mean square. Southall et al. (2007) reviewed relevant data from studies
involving pinnipeds exposed to pulse sounds and concluded that
exposures to 150 to 180 dB generally have limited potential to induce
avoidance behavior.
No known data exist for sound levels resulting from the type of
vibratory hammer and pile sizes that would be used at the proposed
project site; however, measured sound levels for the ``King Kong''
vibratory hammer used in Richmond, California ranged between 163 and
180 dB RMS (Illingworth and Rodkin, 2007). Sound levels at the proposed
project site are expected to be lower because the vibratory hammer
being used has an expected sound level of 165 dB for 24-in piles and
175 dB for 36-in piles. In addition, San Francisco Bay is highly
industrialized and masking of the pile driver by other vessels and
anthropogenic noise within the action area may, especially in the
nearby shipping channel, make construction sounds difficult to hear at
greater distances. Underwater ambient noise levels along the San
Francisco waterfront may be around 133 dB RMS, based on measurements
from the nearby Oakland Outer Harbor (Caltrans, 2009). Seals would
likely also exhibit tolerance or habituation (Richardson et al., 1999)
due to the amount of anthropogenic noise within the proposed project
area and San Francisco Bay as a whole.
No impacts to marine mammal reproduction are anticipated because
there are no known pinniped haul-outs or rookeries within the proposed
project area and San Francisco Bay is not a known breeding ground for
cetaceans. Marine mammals may avoid the area around the hammer, thereby
reducing their exposure to elevated sound levels. NMFS expects any
impacts to marine mammal behavior to be temporary, Level B harassment
(for example, avoidance or alteration of behavior). The Port
conservatively assumes that five 24-in concrete piles would be
installed per day, three 24-in steel piles would be installed per day,
and four 36-in steel piles would be installed per day. Considering that
only one pile type is expected to be installed on any given day, the
maximum number of pile driving days is expected to be 69 over the
eight-month period. Marine mammal injury or mortality is not likely, as
the 180 dB isopleth (NMFS' Level A harassment threshold for cetaceans)
for the impact hammer is 42 m (138 ft) and would be continuously
monitored for marine mammals. Impact pile driving would
[[Page 66279]]
cease if a marine mammal is observed nearing or within a Level A
harassment exclusion zone (50 m [164 ft]). For these reasons, NMFS
expects any changes to marine mammal behavior to be temporary.
Anticipated Effects on Habitat
No permanent detrimental impacts to marine mammal habitat are
expected to result from the proposed project. Pile driving (resulting
in temporary ensonification) may impact prey species and marine mammals
by resulting in avoidance or abandonment of the area; however, these
impacts are expected to be local and temporary. Site conditions are
expected to be improved or substantively unchanged from existing
conditions. The proposed project would result in the net removal of
approximately 3,550 ft\2\ of pile fill and clearing of 47,000 ft\2\ of
timber debris that has collapsed at the end of Pier 36. This debris
includes 350-400 creosote-treated wood pilings. Creosote can leach out
of the wood over time, potentially causing long-term impacts to marine
species. The proposed project would also result in a net reduction of
47,000 ft\2\ of shadow fill (shading over the water). This increase of
unshaded water is expected to be beneficial to benthic invertebrates,
fish, and marine mammals through restoration of ambient light
conditions and increased biological productivity. Overall, the proposed
activity is not expected to cause significant or long-term adverse
impacts on marine mammal habitat.
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.
The Port proposed the following mitigation measures to minimize
adverse impacts to marine mammals:
Sound Attenuation Device
When using impact pile driving to install steel piles in water
depths greater than two feet, an unconfined bubble curtain would be
used to reduce hydroacoustic sound levels to avoid the potential for
injury. The bubble curtain is expected to reduce sound levels by at
least 5 dB.
Establishment of an Exclusion Zone
During all in-water impact pile driving, the Port would establish a
preliminary marine mammal exclusion zone with 50 m (164 ft) radius
around each pile to avoid exposure to sounds at or above 180 dB. This
includes an 8-m (26-ft) buffer zone to further avoid marine mammals
from entering the 180 dB isopleth. The exclusion zone would be
monitored during all impact pile driving to ensure that no marine
mammals enter the 50-m (164-ft) radius. The purpose of this area is to
prevent Level A harassment (injury) of any marine mammal species. Once
underwater sound measurements are taken, the exclusion zone may be
adjusted accordingly so that marine mammals are not exposed to Level A
harassment sound pressure levels. A safety zone for vibratory pile
driving or installation of concrete piles is unnecessary as source
levels would not exceed the Level A harassment threshold.
Pile Driving Shut Down and Delay Procedures
If a protected species observer sees a marine mammal within or
approaching the exclusion zone prior to start of impact pile driving,
the observer would notify the on-site resident engineer (or other
authorized individual) who would then be required to delay pile driving
until the marine mammal has moved outside of the exclusion zone or if
the animal has not been resighted within 15 minutes for pinnipeds or 30
minutes for cetaceans. If a marine mammal is sighted within or on a
path toward the exclusion zone during pile driving, pile driving should
cease until that animal has cleared and is on a path away from the
exclusion zone or 15/30 minutes (pinnipeds/cetaceans) has lapsed since
the last sighting.
Soft-Start Procedures
A ``soft-start'' technique would be used at the beginning of each
pile installation to allow any marine mammal that may be in the
immediate area to leave before the pile hammer reaches full energy. For
vibratory pile driving, the soft-start procedure requires contractors
to initiate noise from the vibratory hammer for 15 seconds at 40-60
percent reduced energy followed by a 1-minute waiting period. The
procedure would be repeated two additional times before full energy may
be achieved. For impact hammering, contractors would be required to
provide an initial set of three strikes from the impact hammer at 40
percent energy, followed by a 1-minute waiting period, then two
subsequent three-strike sets. Soft-start procedures would be conducted
prior to driving each pile if hammering ceases for more than 30
minutes.
Monitoring for Herring
Monitoring for herring spawning events would be conducted on a
daily basis between December 1 and February (although pile driving is
expected to be complete in December). If a herring spawning event is
observed, in-water work would cease for a period of two weeks following
the spawning event (a measure designed to reduce impacts to fish).
Pinniped presence can be sporadic and unpredictable during herring runs
in San Francisco Bay; therefore, this mitigation measure would minimize
impacts to marine mammals.
NMFS has carefully evaluated the applicant's proposed mitigation
measures and considered a range of other measures in the context of
ensuring that NMFS prescribes the means of effecting the least
practicable adverse impact on the affected marine mammal species and
stocks and their habitat. Our evaluation of potential measures included
consideration of the following factors in relation to one another: (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; and (3) the
practicability of the measure for applicant implementation, including
consideration of personnel safety, and practicality of implementation.
Based on our evaluation of the applicant's proposed measures, NMFS
has preliminarily determined that the proposed mitigation measures
provide the means of effecting the least practicable adverse impacts on
marine mammals species or stocks and their habitat, paying particular
attention to rookeries, mating grounds, and areas of similar
significance.
Proposed Monitoring and Reporting
In order to issue an IHA 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 216.104 (a)(13) 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
[[Page 66280]]
populations of marine mammals that are expected to be present.
Hydroacoustic monitoring would be performed at the initial
installation of each pile type (24-in concrete, 24-in steel, and 36-in
steel) to ensure that the harassment isopleths are not extending past
the calculated distances described in this notice. The Port must
designate at least one biologically-trained, on-site individual,
approved in advance by NMFS, to monitor the Level B harassment zone
area for marine mammals 30 minutes before, during, and 30 minutes after
all impact pile driving activities and call for shut down if any marine
mammal is observed within or approaching the designated exclusion zone
(preliminarily set at 50 m [164 ft]). In addition, at least two NMFS-
approved protected species observers would conduct behavioral
monitoring out to 1,900 m during all vibratory pile driving for the
first two weeks of activity to validate take estimates and evaluate the
behavioral impacts piles driving has on marine mammals out to the Level
B harassment isopleth. If there are no observations of marine mammals
within the Level B harassment isopleth during this time, behavioral
monitoring may be reduced to a level agreed upon by the applicant and
NMFS. Note that for impact hammering, the initial Level B (160 dB)
harassment isopleths are 42 m (138 ft) for the concrete piles and 750 m
(2,460 ft) for the steel piles. For vibratory hammering, the initial
estimated distance is 1,900 m (6,233 ft). If light condition is low
(such as early morning or late afternoon), protected species observers
would use infrared scopes to conduct their observations.
Protected species observers would be provided with the equipment
necessary to effectively monitor for marine mammals (for example, high-
quality binoculars, spotting scopes, compass, and range-finder) in
order to determine if animals have entered into the exclusion zone or
Level B harassment isopleth and to record species, behaviors, and
responses to pile driving. If hydroacoustic monitoring indicates that
threshold isopleths are greater than originally calculated, the Port
would contact NMFS within 48 hours and make the necessary adjustments.
Likewise, if threshold isopleths are actually less than originally
calculated, adjustments may be made. Protected species observers would
be required to submit a report to NMFS within 90 days of completion of
pile driving. The report would include data from marine mammal
sightings (such as species, group size, and behavior), any observed
reactions to construction, distance to operating pile hammer, and
construction activities occurring at time of sighting.
Estimated Take by Incidental Harassment
Except with respect to certain activities not pertinent here, the
MMPA defines ``harassment'' as:
any act of pursuit, torment, or annoyance which (i) Has the
potential to injure a marine mammal or marine mammal stock in the
wild [Level A harassment]; or (ii) has the potential to disturb a
marine mammal or marine mammal stock in the wild by causing
disruption of behavioral patterns, including, but not limited to,
migration, breathing, nursing, breeding, feeding, or sheltering
[Level B harassment].
Based on the application and subsequent analysis, the impact of the
described pile driving operations may result in, at most, short-term
modification of behavior by small numbers of marine mammals within the
action area. Marine mammals may avoid the area or temporarily alter
their behavior at time of exposure.
Current NMFS practice regarding exposure of marine mammals to
anthropogenic noise is that in order to avoid the potential for injury
(PTS), cetaceans and pinnipeds should not be exposed to impulsive
sounds of 180 and 190 dB or above, respectively. This level is
considered precautionary as it is likely that more intense sounds would
be required before injury would actually occur (Southall et al., 2007).
Potential for behavioral harassment (Level B) is considered to have
occurred when marine mammals are exposed to sounds at or above 160 dB
for impulse sounds (such as impact pile driving) and 120 dB for non-
pulse noise (such as vibratory pile driving). These levels are also
considered precautionary.
Distances to NMFS' harassment thresholds were calculated based on
the sound levels at each source and the expected attenuation rate of
sound (Table 3). Two sets of threshold distances were identified: one
for concrete piles and one for steel piles. The threshold distances
listed for the steel piles are those expected from the 36-in steel pile
driving activities, as they would also encompass the isopleths for the
24-in steel piles. The 42-m (268-ft) distance to the Level A harassment
threshold provides protected species observers plenty of time and
adequate visibility to prevent marine mammals from entering the area
during impact pile driving. This would prevent marine mammals from
being exposed to sound levels that reach the Level A harassment
threshold. In-air sound from pile driving also has the potential to
affect marine mammals. However, in-air sound is not a concern here
because there are no pinniped haul-outs near the project area.
Table 3--Calculated Underwater Distances to NMFS' Marine Mammal Harassment Threshold Levels
----------------------------------------------------------------------------------------------------------------
Distance from source (24-in concrete Distance from source (36-in steel
Threshold piles) piles)
----------------------------------------------------------------------------------------------------------------
120 dB RMS (Level B--continuous). n/a................................... 1,900 m (6,233 ft).
160 dB RMS (Level B--impulse).... 42 m (138 ft)......................... 750 m (2,460 ft).
180/190 dB RMS (Level A)......... n/a................................... 42 m (138 ft).
----------------------------------------------------------------------------------------------------------------
The estimated number of marine mammals potentially taken is based
on marine mammal monitoring reports prepared by the California
Department of Transportation during similar activities in San Francisco
Bay and on discussions with the NMFS Southwest Regional Office. The
California Department of Transportation's San Francisco-Oakland Bay
Bridge marine mammal monitoring reports were used to estimate the
number of pinnipeds near the Pier 36/Brannan Street Wharf area as both
sites are relatively close in distance and are similar in bathymetric
features. However, monitoring conducted for the San Francisco-Oakland
Bay Bridge project was in close proximity to a haul-out area, while the
Pier 36/Brannan Street Wharf location is in an area of high commercial
boat activity and no adjacent haul-outs. Therefore, the Caltrans data
likely overestimate marine mammal abundance for the Pier 36/Brannan
Street Wharf location. Based on consultation with the NMFS Southwest
Regional Office, review of the monitoring reports described above, and
the estimated number of pile driving
[[Page 66281]]
days, the Port requested authorization for the incidental take of 138
harbor seals (an average of 2 per day), 69 California sea lions (an
average of 1 per day), 69 harbor porpoises (an average of 1 per day),
and 2 gray whales (2 annually). Based on further consultation with the
NMFS Southwest Regional Office and previous authorizations in this
region, NMFS is proposing to authorize the take of five gray whales
annually, rather than two. These numbers indicate the maximum number of
animals expected to occur within the largest Level B harassment
isopleth (1,900 m).
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 number of factors which include, but are not limited
to, number of anticipated injuries or mortalities (none of which would
be authorized here), number, nature, intensity, and duration of Level B
harassment, and the context in which takes occur.
As described above, marine mammals would not be exposed to
activities or sound levels which would result in injury (PTS), serious
injury, or mortality. Pile driving would occur in shallow coastal
waters of the Columbia River. The action area (waters around Terminal
5) is not considered significant habitat for pinnipeds. The closest
haul-out is 3.2 km (2 mi) away, which is well outside the project
area's largest harassment zone. Marine mammals approaching the action
area would likely be traveling or opportunistically foraging. The
amount of take the Port has requested, and NMFS proposes to authorize,
is considered small (less than one percent) relative to the estimated
populations of 34,233 Pacific harbor seals, 238,000 California sea
lions, 9,189 harbor porpoises, and 18,813 gray whales. Marine mammals
may be temporarily impacted by pile driving noise. However, marine
mammals are expected to avoid the area, thereby reducing exposure and
impacts. Pile driving activities are expected to occur for
approximately 69 days. Furthermore, San Francisco Bay is a highly
industrialized area, so animals are likely tolerant or habituated to
anthropogenic disturbance, including low level vibratory pile driving
operations, and noise from other anthropogenic sources (such as
vessels) may mask construction related sounds. There is no anticipated
effect on annual rates of recruitment or survival of affected marine
mammals.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the mitigation and monitoring
measures, NMFS preliminarily determines that the Port's proposed pile
driving activities will result in the incidental take of small numbers
of marine mammals, by Level B harassment only, and that the total
taking from will have a negligible impact on the affected species or
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)
No marine mammal species listed under the ESA are anticipated to
occur within the action area. Therefore, section 7 consultation under
the ESA is not 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, NMFS is preparing an Environmental
Assessment (EA) to consider the direct, indirect, and cumulative
effects to marine mammals and other applicable environmental resources
resulting from issuance of a one-year IHA and the potential issuance of
future authorizations for incidental harassment for the ongoing
project. Upon completion, this EA will be available on the NMFS Web
site listed in the beginning of this document (see ADDRESSES).
Dated: October 19, 2011.
Helen M. Golde,
Deputy Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2011-27739 Filed 10-25-11; 8:45 am]
BILLING CODE 3510-22-P