[Federal Register Volume 74, Number 158 (Tuesday, August 18, 2009)]
[Notices]
[Pages 41684-41689]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-19771]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0638-XI68


Taking of Marine Mammals Incidental to Specified Activities; 
Construction of the East Span of the San Francisco-Oakland Bay Bridge

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

ACTION:  Notice of issuance of an incidental harassment authorization.

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SUMMARY:  In accordance with provisions of the Marine Mammal Protection 
Act (MMPA) as amended, notification is hereby given that an Incidental 
Harassment Authorization (IHA) has been issued to the California 
Department of Transportation (CALTRANS) to take small numbers of 
California sea lions, Pacific harbor seals, harbor porpoises, and gray 
whales, by harassment, incidental to construction of a replacement 
bridge for the East Span of the San Francisco-Oakland Bay Bridge (SF-
OBB) in California.

DATES:  This authorization is effective from August 14, 2009 until 
August 13, 2010.

ADDRESSES:  A copy of the application, IHA, and/or a list of references 
used in this document may be obtained by writing to P. 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.

FOR FURTHER INFORMATION CONTACT:  Shane Guan, NMFS, (301) 713-2289, ext 
137, or Monica DeAngelis, NMFS, (562) 980-3232.

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, the taking is 
limited to harassment, notice of a proposed authorization is provided 
to the public for review.
    Permission shall be granted if NMFS finds that the taking will have 
a negligible impact on the species or stock(s) and will not have an 
unmitigable adverse impact on the availability of the species or 
stock(s) for certain subsistence uses and if the permissible methods of 
taking and requirements pertaining to the mitigation, monitoring, and 
reporting of such taking are set forth. NMFS has defined egligible 
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. Except with respect to certain 
activities not pertinent here, the MMPA defines ``harassment'' as:

[[Page 41685]]

    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].
    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 
small numbers of marine mammals. Within 45 days of the close of the 
comment period, NMFS must either issue or deny issuance of the 
authorization.

Summary of Request

    On March 3, 2008, CALTRANS submitted a request to NOAA requesting 
renewal of an IHA for the possible harassment of small numbers of 
California sea lions (Zalophus californianus), Pacific harbor seals 
(Phoca vitulina richardsii), harbor porpoises (Phocoena phocoena), and 
gray whales (Eschrichtius robustus) incidental to construction of a 
replacement bridge for the East Span of the SF-OBB, in San Francisco 
Bay (SFB), California. An IHA was previously issued to CALTRANS for 
this activity on May 2, 2007 and it expired on May 1, 2008 (72 FR 
25748, May 7, 2007). However, no pile driving activities were conducted 
during that period. A detailed description of the SF-OBB project was 
provided in the November 14, 2003 (68 FR 64595) Federal Register notice 
of an earlier IHA and is not repeated here. Please refer to that 
Federal Register notice.
    On June 2, 2008, CALTRANS provided an update on the proposed pile 
driving activities planned for the 2008 - 2009 season. In its update, 
CALTRANS states that pile driving for the 2009 construction would be 
driving the 42 - 48 in (0.17 - 0.19 m) diameter temporary piles, as 
opposed to the 5.9 - 8.2 ft (1.8 - 2.5 m) diameter permanent piles. 
Therefore, the noise from pile driving of these temporary piles would 
be far less than from previous pile driving activities. In addition, 
CALTRANS indicates that deployment of an air bubble curtain would not 
be feasible for the driving of these smaller temporary piles due to the 
complexity of the driving frames. A Federal Register notice of receipt 
of the application, the modification of mitigation measures, and 
proposed IHA was published on July 3, 2008 (73 FR 38180), along with 
new safety zones without an air bubble system. On September 15, 2008, 
CALTRANS provided certain acoustic measures for testing pile driving of 
temporary piles without air bubble curtain system.
    On January 29, 2009, CAlTRANS provided NMFS with a detailed 
description of the SF-OBB construction work and all acoustic 
measurements without air bubble curtains (CALTRANS, 2009). 
Specifically, the modified proposed construction activities include 
driving of temporary piles at Temporary Towers D, F and G which are 
necessary for the erection of falsework to support the Self-Anchored 
Suspension Span (SAS) portion of the SF-OBB project. Each tower has a 
north and south node. All three Temporary Towers are located to the 
east of Yerba Buena Island (YBI). Temporary Tower D is located 
approximately 60 m (197 ft) from the eastern shoreline of YBI. 
Temporary Tower F is located approximately 100 m (328 ft) east of 
Temporary Tower D. Temporary Tower G is located approximately 100 m 
(328 ft) east of Temporary Tower F.
    In addition, CALTRANS indicated that certain piles would be 
installed by using both vibratory and impact hammers, instead of only 
impact hammers as in the previous IHAs. Unlike pile driving using 
impact hammers which involves the repeated striking of the head of a 
steel pile by a double-acting hydraulic hammer, vibratory pile driving 
was achieved by means of a variable eccentric vibrator attached to the 
head of the pile. The pile driving machine is lifted and positioned 
over the pile by means of an excavator or crane, and is fastened to the 
pile by a clamp and/or bolts. The majority of piles were initially 
driven into the substrate by vibration, over a period of several 
minutes.
    The use of vibratory pile driving has the benefit of having lower 
impact to anadramous fish species in the vicinity of the proposed 
project area, since the instantaneous sound pressure levels are lower 
when compared to noise from impact hammers. Therefore, fish species in 
close vicinity of the project area are less likely to suffer from 
mortality and injury (Hawkins, 2006). Empirical hydroacoustic 
measurements of impact and vibratory hammers during CALTRANS testing 
pile driving in San Francisco Bay on October 23, December 9, and 
December 11, 2008, are shown in Table 1. Hydroacoustic monitors used 
data collected on December 9 and December 11, 2008, determine the 
distance of the 120 dB isopleths. At 1,900 m from the vibratory pile 
driving, sound levels are in the low 120 dB rms range. At this distance 
pile driving was audible but not measurable due to ambient noise 
(CALTRANS, 2009).
    Both impact and vibratory pile driving is expected to be short-term 
in duration. Pile driving conducted to collect hydroacoustic data 
showed that the vibration of the bottom segment of each pile took 
approximately 3 minutes; the vibration of the top segment of each pile 
took approximately 8 minutes; and that the impact driving of the top 
segment of each pile lasted an average of 15 minutes. On average, it 
took about 25 minutes of driving time to install each temporary pile 
(CALTRANS, 2009). The entire project is expected to be completed by the 
end of 2009.
    Please refer to the CALTRANS memos for a detailed description of 
the modification of the proposed construction activities.

        Table 1. Root-Mean-Square Isopleths Based on Hydroacoustic Monitoring in San Francisco Bay by Illingworth & Rodkin, Inc. (CALTRANS, 2009)
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                 Sound Level (dB re 1 microPa rms)                          120*                160* *               180* *                190* *
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Radius for Vibratory Pile Driving                                              1,900 m                250 m                 15 m         does not exist
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[[Page 41686]]

 
Comment: The Comrequired
 in the current IHA.
General information on the marine mammal species found in
 California waters can be found in Caretta et al. (2007), which is
 available at the following URL: http://www.nmfs.noaa.gov/pr/pdfs/sars/po2007.pdf. Refer to that document for information on these
 species.
The marine mammals most likely to be found in the SF-OBB area are
 the California sea lion, Pacific harbor seal, and harbor
 porpoise. From December through May gray whales may also be
 present in the SF-OBB area. Information on California sea lion,
 harbor seal, and gray whale was provided in the November 14, 2003
 (68 FR 64595), Federal Register notice; information on harbor
 porpoise was pve determined that open-water pile driving, as
 outlined in the project description, has the potential to result
 in behavioral harassment of California sea lions, Pacific harbor
 seals, harbor porpoises, and gray whales that may be swimming,
 foraging, or resting in the project vicinity while pile driving
 is being conducted. Pile driving could potentially harass those
 few pinnipeds that are in the water close to the project site,
 whether their heads are above or below the surface.
Based on airborne noise levels measured and on-site monitoring
 conducted during 2004 under the previous IHAs, noise levels from
 the East Span project did not result in the harassment of harbor
 seals hauled out on Yerba Buenaxpected to result in
 harassment of the sea lions hauled out at Pier 39, as airborne
 and waterborne sound pressure levels (SPLs) would attenuate to
 levels below where harassment would be expected by the time they
 reach that haul-out site, 5.7 km (3.5 miles) from the project
 site. Therefore, no pinniped hauled out would be affected as a
 result of the proposed pile-driving. A detailed description of
 the acoustic measurements is provided in the 2004 CALTRANS marine
 mammal and acoustic monitoring report for the same activity
 (CALTRANS 2005). With the modification of the proposed
 construction activities involving smaller piles, NMFS believes
 that the in-air noise would only become less intense, therefore,
 no pinniped hauled out would be affected.
In contrary to impact pile driving, which the striking hammers
 produce intense bangs with rapid raise of acoustic energy within
 extremely short pulse duration, noises generated by vibratory
 pile driving have lower instantaneous SPL but longer duration
 (HDR Alaska et al., 2006).
However, since the transient sound produced by vibratory pile
 driving has longer duration then impact pile driving pulses, it
 is arguable that a single batch of vibratory pile driving noise
 could contain more acoustic energy than a single impact hammer
 pulse in terms of sound exposure levels (SEL). To mitigate the
 low level behavioral impact from this prolonged transient noise,
 currently NMFS uses the received level of 120 dB re 1 microPa rms
 as the onset of behavioral harassment for marine mammals from
 vibratory pile driving noise. In comparison, NMFS uses the
 received level of 160 dB re 1 microPa rms as the onset of
 behavioral harassment for marine mammals from the much shorter
 impulse, or noise from impact pile driving.
Since the modified proposed SF-OBB construction project would be
 installing smaller temporary piles with no air bubble curtain,
 and since the pile driving activities would be performed by using
 both impact and vibratory hammers, NMFS conducted an comparison
 of isopleths from large foundation pile driving activities using
 an air bubble curtain system (Table 2) with the current testing
 pile driving without an air bubble curtain by both impact and
 vibratory pile driving (Table 1). The acoustic data used from the
 foundation pile driving were provided by CALTRANS (CALTRANS,
 2005). The comparison shows that the radius for the zone of
 influence (ZOI) for Level B behavioral harassment, as defined by
 marine mammals exposed to received SPL (impulse) of 160 dB re 1
 microPa rms, for the previous larger pile driving activities
 using air bubble curtain was about 2,000 m. This distance is
 approximately the same as the radius for the proposed vibratory
 pile driving for the smaller temporary piles at received SPL of
 120 dB re 1 microPa rms, a level thought may cause Level B
 behavioral harassment to marine mammals by vibratory pile
 driving. Therefore, NMFS concludes that the potential impacts to
 marine mammals from the proposed SF-OBB construction project
 involving installation of smaller temporary piles using both
 impact and vibratory hammers without deployment of an air bubble
 curtain system are the same as the previous construction
 activities of installation larger foundation piles using impact
 hammers and air bubble curtain system as a mitigation
 measure.6,L2,i1,s50,14C,10C,10,10C,10C
50m West (made by Caltrans)*                                                        --                  177                  186   .....................
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[[Page 41687]]
                                 Table 2. Summary of Hydroacoustic Measurements Reported as dB re 1 microPa - Pier E3W Marine Mammal Hydroacoustic Characterization, 10/13/2004 (adopted from CALTRANS, 2005)1Position1Water Depth1South Pile
 
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* Continuous measurement. All others are spot measurements of at least 5 minutes in duration.
** Many obstructions including Pier E3E.

    For reasons provided in greater detail in NMFS November 14, 2003 
(68 FR 64595) Federal Register notice and in CALTRANS June 2004, 
January 2005 annual monitoring reports, and marine mammal observation 
memoranda between February and September, 2006, the proposed 
construction would result in harassment of only small numbers of harbor 
seals and would not result in more than a negligible impact on marine 
mammal stocks and their habitat. This was achieved by implementing a 
variety of monitoring and mitigation measures including marine mammal 
monitoring before and during pile driving, establishing safety zones, 
ramping up pile driving, and deploying air bubble curtain to attenuate 
underwater pile driving sound. However, with no air bubble curtain 
being deployed for the proposed pile driving of smaller temporary 
piles, additional cautions must be exercised to ensure that no marine 
mammals will be taken by Level A (i.e., injury) harassment. Based on 
the pinniped distribution within the proposed project area and prior 
monitoring reports, NMFS estimates that up to 5 harbor seals and 5 
California sea lions could be taken by Level B behavioral harassment as 
a result of the proposed temporary pile driving project.
    Short-term impacts to habitat may include minimal disturbance of 
the sediment where the channels are dredged for barge access and where 
individual bridge piers are constructed. Long-term impacts to marine 
mammal habitat will be limited to the footprint of the piles and the 
obstruction they will create following installation. However, this 
impact is not considered significant as the marine mammals can easily 
swim around the piles of the new bridge, as they currently swim around 
the existing bridge piers.

Mitigation Measures

    For the issuance of the IHA for the planned 2008 2009 SF-OBB 
planned construction activities to reduce adverse impacts to marine 
mammals to the lowest extent practicable, NMFS requires the following 
mitigation measures to be implemented.

Establishment of Safety/Buffer Zones

    CALTRANS indicated that for the planned 2008 2009 SF-OBB 
construction pile driving activities, an air bubble curtain cannot be 
deployed due to the complexity of the driving frame. Therefore, 
proposed shutdown safety zones corresponding to where a marine mammal 
could be injured would be established based on empirical field 
measurements of pile driving sound levels.
    These safety zones shall include all areas where the underwater 
SPLs are anticipated to equal or exceed 190 dB re 1 microPa rms 
(impulse) for pinnipeds and 180 dB re 1 microPa rms (impulse) for gray 
whales and harbor porpoises, and be monitored at all times when pile 
driving is underway. No additional safety zone will be established for 
vibratory pile driving since the measured source levels will not exceed 
the 180 and 190 dB re 1 microPa.
    Observers on boats shall survey the safety zone to ensure that no 
marine mammals are seen within the zone before pile driving of a pile 
segment begins. If marine mammals are found within the safety zone, 
pile driving of the segment shall be delayed until they move out of the 
area. If a marine mammal is seen above water and then dives below, the 
contractor shall wait 15 minutes and if no marine mammals are seen by 
the observer in that time it will be assumed that the animal has moved 
beyond the safety zone. This 15-minute criterion is based on scientific 
evidence that harbor seals in San Francisco Bay dive for a mean time of 
0.50 minutes to 3.33 minutes (Harvey and Torok, 1994), and the mean 
diving duration for harbor porpoises ranges from 44 to 103 seconds 
(Westgate et al., 1995). However, due to the limitations of monitoring 
from a boat, there can be no assurance that the zone will be devoid of 
all marine mammals at all times.
    Once the pile driving of a segment begins it cannot be stopped 
until that segment has reached its predetermined depth due to the 
nature of the sediments underlying the Bay. If pile driving stops and 
then resumes, it would potentially have to occur for a longer time and 
at increased energy levels. In sum, this would simply amplify impacts 
to marine mammals, as they would endure potentially higher SPLs for 
longer periods of time. Pile segment lengths and wall thickness have 
been specially designed so that when work is stopped between segments 
(but not during a single segment), the pile tip is never

[[Page 41688]]

resting in highly resistant sediment layers. Therefore, because of this 
operational situation, if seals, sea lions, or harbor porpoises enter 
the safety zone after pile driving of a segment has begun, pile driving 
will continue and marine mammal observers will monitor and record 
marine mammal numbers and behavior. However, if pile driving of a 
segment ceases for 30 minutes or more and a marine mammal is sighted 
within the designated safety zone prior to commencement of pile 
driving, the observer(s) must notify the Resident Engineer (or other 
authorized individual) immediately and follow the mitigation 
requirements as outlined previously in this document.

Soft Start

    It should be recognized that although marine mammals will be 
protected from Level A harassment (i.e., injury) through marine mammal 
observers monitoring a 190-dB safety zone for pinnipeds and 180-dB 
safety zone for cetaceans, mitigation may not be 100 percent effective 
at all times in locating marine mammals. Therefore, in order to provide 
additional protection to marine mammals near the project area by 
allowing marine mammals to vacate the area prior to receiving a 
potential injury, CALTRANS shall also oft start the hammer prior to 
operating at full capacity. CALTRANS typically implements a oft start 
with several initial hammer strikes at less than full capacity (i.e., 
approximately 40-60 percent energy levels) with no less than a 1 minute 
interval between each strike. Similar levels of noise reduction are 
expected underwater. Therefore, the contractor shall initiate pile 
driving hammers with this procedure in order to allow pinnipeds or 
cetaceans in the area to voluntarily move from the area. This should 
expose fewer animals to loud sounds both underwater and above water 
noise. This would also ensure that, although not expected, any 
pinnipeds and cetaceans that are missed during safety zone monitoring 
will not be injured.

Compliance with Equipment Noise Standards

    To mitigate noise levels and, therefore, impacts to California sea 
lions, Pacific harbor seals, harbor porpoises, and gray whales, all 
construction equipment shall comply as much as possible with applicable 
equipment noise standards of the U.S. Environmental Protection Agency, 
and all construction equipment shall have noise control devices no less 
effective than those provided on the original equipment.

Monitoring

    The following monitoring measures are required for the proposed SF-
OBB construction activities.

Visual Observations

    Safety zone monitoring shall be conducted during driving of all 
open-water piles without cofferdams and with cofferdams when underwater 
SPLs reach 190 dB RMS or greater. Monitoring of the pinniped and 
cetacean safety zones shall be conducted by a minimum of three 
qualified NMFS-approved observers for each safety zone. One three-
observer team shall be required for the safety zones around each pile 
driving site, so that multiple teams shall be required if pile driving 
is occurring at multiple locations at the same time. The observers 
shall begin monitoring at least 30 minutes prior to startup of the pile 
driving. Most likely observers will conduct the monitoring from small 
boats, as observations from a higher vantage point (such as the SF-OBB) 
are not practical. Pile driving shall not begin until the safety zones 
are clear of marine mammals. However, as described in the Mitigation 
section, once pile driving of a segment begins, operations will 
continue uninterrupted until the segment has reached its predetermined 
depth. However, if pile driving of a segment ceases for 30 minutes or 
more and a marine mammal is sighted within the designated safety zone 
prior to commencement of pile driving, the observer(s) must notify the 
Resident Engineer (or other authorized individual) immediately and 
follow the mitigation requirements as outlined previously (see 
Mitigation). Monitoring shall continue through the pile driving period 
and shall end approximately 30 minutes after pile driving has been 
completed. Biological observations shall be made using binoculars 
during daylight hours.
    In addition to monitoring from boats, during open-water pile 
driving, monitoring at one control site (i.e., harbor seal haul-out 
sites and the waters surrounding such sites not impacted by the East 
Span Project's pile driving activities, e.g., Mowry Slough) shall be 
designated and monitored for comparison. Monitoring shall be conducted 
twice a week at the control site whenever open-water pile driving is 
being conducted. Data on all observations shall be recorded and shall 
include items such as species, numbers, behavior, details of any 
observed disturbances, time of observation, location, and weather. The 
reactions of marine mammals shall be recorded based on the following 
classifications that are consistent with the Richmond Bridge Harbor 
Seal survey methodology (for information on the Richmond Bridge 
authorization, see 68 FR 66076, November 25, 2003): (1) No response, 
(2) head alert (looks toward the source of disturbance), (3) approach 
water (but not leave), and (4) flush (leaves haul-out site). The number 
of marine mammals under each disturbance reaction shall be recorded, as 
well as the time when seals re-haul after a flush.

Acoustical Observations

    Airborne noise level measurements have been completed and 
underwater environmental noise levels will continue to be measured as 
part of the East Span Project. The purpose of the underwater sound 
monitoring is to establish the safety zone of 190 dB re 1 micro-Pa RMS 
(impulse) for pinnipeds and the safety zone of 180 dB re 1 micro-Pa RMS 
(impulse) for cetaceans. Monitoring will be conducted during the 
driving of the last half (deepest pile segment) for any given open-
water pile. One pile in every other pair of pier groups will be 
monitored. One reference location will be established at a distance of 
100 m (328 ft) from the pile driving. Sound measurements will be taken 
at the reference location at two depths (a depth near the mid-water 
column and a depth near the bottom of the water column but at least 1 m 
(3 ft) above the bottom) during the driving of the last half (deepest 
pile segment) for any given pile. Two additional in-water spot 
measurements will be conducted at appropriate depths (near mid water 
column), generally 500 m (1,640 ft) in two directions either west, 
east, south or north of the pile driving site will be conducted at the 
same two depths as the reference location measurements. In cases where 
such measurements cannot be obtained due to obstruction by land mass, 
structures or navigational hazards, measurements will be conducted at 
alternate spot measurement locations. Measurements will be made at 
other locations either nearer or farther as necessary to establish the 
approximate distance for the safety zones. Each measuring system shall 
consist of a hydrophone with an appropriate signal conditioning 
connected to a sound level meter and an instrument grade digital 
audiotape recorder (DAT). Overall SPLs shall be measured and reported 
in the field in dB re 1 micro-Pa rms (impulse). An infrared range 
finder will be used to determine distance from the monitoring location 
to the pile. The recorded data will be analyzed to determine the 
amplitude, time history and frequency content of the impulse.

[[Page 41689]]
                                                                                                                                                                                              Hammer: Menck 1,7002RMS impulse2Peak1North Pile
Reporting

    Under previous IHAs, CALTRANS submitted weekly marine mammal 
monitoring reports for the time when pile driving was commenced. In 
August 2006, CALTRANS submitted its Hydroacoustic Measurement at Piers 
T1 and E2 report. This report is available by contacting NMFS (see 
ADDRESSES) or on the Web at http://biomitigation.org.
    Under the proposed IHA, coordination with NMFS will occur on a 
weekly basis. During periods with open-water pile driving activity, 
weekly monitoring reports will be made available to NMFS and the public 
at http://biomitigation.org. These weekly reports will include a 
summary of the previous week monitoring activities and an estimate of 
the number of seals and sea lions that may have been disturbed as a 
result of pile driving activities.
    In addition, CALTRANS will to provide NMFS' Southwest Regional 
Administrator with a draft final report within 90 days after completion 
of the westbound Skyway contract and 90 days after completion of the 
Suspension Span foundations contract. This report should detail the 
monitoring protocol, summarize the data recorded during monitoring, and 
estimate the number of marine mammals that may have been harassed due 
to pile driving. If no comments are received from NMFS Southwest 
Regional Administrator within 30 days, the draft final report will be 
considered the final report. If comments are received, a final report 
must be submitted within 30 days after receipt of comments.

National Environmental Policy Act (NEPA)

    NMFS prepared an Environmental Assessment (EA) for the take of 
marine mammals incidental to construction of the East Span of the SF-
OBB and made a Finding of No Significant Impact (FONSI) on November 4, 
2003. Due to the modification of part of the construction project and 
the mitigation measures, NMFS reviewed additional information from 
CALTRANS regarding empirical measurements of pile driving noises for 
the smaller temporary piles without an air bubble curtain system and 
the use of vibratory pile driving. NMFS prepared a Supplemental 
Environmental Assessment (SEA) and analyzed the potential impacts to 
marine mammals that would result from the modification of the action. A 
Finding of No Significant Impact (FONSI) was signed on August 5, 2009. 
A copy of the SEA and FONSI is available upon request (see ADDRESSES).

Endangered Species Act (ESA)

    On October 30, 2001, NMFS completed consultation under section 7 of 
the ESA with the Federal Highway Administration (FHWA) on the CALTRANS' 
construction of a replacement bridge for the East Span of the SF-OBB in 
California. Anadromous salmonids are the only listed species which may 
be affected by the project. The finding contained in the Biological 
Opinion was that the proposed action at the East Span of the SF-OBB is 
not likely to jeopardize the continued existence of listed anadromous 
salmonids, or result in the destruction or adverse modification of 
designated critical habitat for these species. Listed marine mammals 
are not expected to be in the area of the action and thus would not be 
affected.
    NMFS proposed issuance of an IHA to CALTRANS constitutes an agency 
action that authorizes an activity that may affect ESA-listed species 
and, therefore, is subject to section 7 of the ESA. The effects of the 
activities on listed salmonids were analyzed during consultation 
between the FHWA and NMFS, and the underlying action has not changed 
from that considered in the consultation. Therefore, the effects 
discussion contained in the Biological Opinion issued to the FHWA on 
October 30, 2001, pertains also to this action. NMFS has determined 
that issuance of an IHA for this activity does not lead to any effects 
on listed species apart from those that were considered in the 
consultation on FHWA's action.

Determinations

    For the reasons discussed in this document and in previously 
identified supporting documents, NMFS has preliminarily determined that 
the impact of pile driving and other activities associated with 
construction of the East Span Project should result, at worst, in the 
Level B harassment of small numbers of California sea lions, Pacific 
harbor seals, harbor porpoises, and potentially gray whales that 
inhabit or visit SFB in general and the vicinity of the SF-OBB in 
particular. While behavioral modifications, including temporarily 
vacating the area around the construction site, may be made by these 
species to avoid the resultant visual and acoustic disturbance, the 
availability of alternate areas within SFB and haul-out sites 
(including pupping sites) and feeding areas within the Bay has led NMFS 
to determine that this action will have a negligible impact on 
California sea lion, Pacific harbor seal, harbor porpoises, and gray 
whale populations along the California coast.
    In addition, no take by Level A harassment (injury) or death is 
anticipated and harassment takes should be at the lowest level 
practicable due to incorporation of the mitigation measures mentioned 
previously in this document. The activity will not have an unmitigable 
adverse impact on subsistence uses of marine mammals described in MMPA 
section 101(a)(5)(D)(i)(II).

Authorization

    NMFS has issued an IHA to CALTRANS for the potential harassment of 
small numbers of harbor seals, California sea lions, harbor porpoises, 
and gray whales incidental to construction of a replacement bridge for 
the East Span of the San Franciso-Oakland Bay Bridge in California, 
provided the previously mentioned mitigation, monitoring, and reporting 
requirements are incorporated.

    Dated: August 12, 2009.
James H. Lecky,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. E9-19771 Filed 8-17-09; 8:45 am]
BILLING CODE 3510-22-S