[Federal Register Volume 66, Number 227 (Monday, November 26, 2001)]
[Notices]
[Pages 59001-59006]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-29391]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 110801C]


Small Takes 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 receipt of application and proposed authorization for 
a small take exemption; request for comments.

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SUMMARY: NMFS has received a request from the California Department of 
Transportation (CALTRANS) for an authorization to take small numbers of 
marine mammals by harassment incidental to construction of a 
replacement bridge for the East Span of the San Francisco-Oakland Bay 
Bridge (SF-OBB). Under the Marine Mammal Protection Act (MMPA), NMFS is 
requesting comments on its proposal to authorize CALTRANS to 
incidentally take, by harassment, small numbers of California sea 
lions, Pacific harbor seals, and possibly gray whales in San Francisco 
Bay.

DATES: Comments and information must be received no later than December 
26, 2001.

ADDRESSES: Comments on the application should be addressed to Donna 
Wieting, Chief, Marine Mammal Conservation Division, Office of 
Protected Resources, NMFS, 1315 East-West Highway, Silver Spring, MD 
20910-3225. A copy of the application, and a list of references used in 
this document may be obtained by writing to this address or by 
telephoning one of the contacts listed here. Comments will not be 
accepted if submitted via e-mail or the Internet.

FOR FURTHER INFORMATION CONTACT: Simona Perry Roberts, (301) 713-2322, 
ext 106; or Tina Fahy, (562) 980-4023.

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, notice of a proposed authorization is 
provided to the public for review.
    Permission may be granted if NMFS finds that the taking will have 
no more than 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 subsistence uses and that the permissible 
methods of taking and requirements pertaining to the monitoring and 
reporting of such taking are set forth. NMFS has defined ``negligible 
impact'' in 50 CFR 216.103 as:

    ...an impact resulting from the specified activity that cannot 
be reasonably expected to, and is not reasonably likely to, 
adversely affect the species or stock through effects on annual 
rates of recruitment or survival.

    Subsection 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. The MMPA defines ``harassment'' as:

    ...any act of pursuit, torment, or annoyance which (a) has the 
potential to injure a marine mammal or marine mammal stock in the 
wild (``Level A harassment''); or (b) 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'').

    Subsection 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 September 14, 2001, NMFS received a request from CALTRANS 
requesting an Incidental Harassment Authorization (IHA) for the 
possible harassment of small numbers of California sea lions (Zalophus 
californianus), Pacific harbor seals (Phoca vitulina richardsii), and 
gray whales (Eschrichtius robustus) incidental to construction of a 
replacement bridge for the East Span of the SF-OBB.

[[Page 59002]]

Project Description

    The East Span Project will provide a seismically upgraded vehicular 
crossing for current and future users. The existing East Span must be 
replaced or retrofitted because it is not expected to withstand a 
maximum credible earthquake on the San Andreas (Richter 8) or Hayward 
(Richter 7.25) faults, it does not meet lifeline criteria for providing 
emergency relief access following a maximum credible earthquake, and it 
does not meet current operational and safety design standards.
    The new bridge will be constructed north of the existing East Span 
and will be approximately 3,514 meters (m) (2.18 mi) long and 
approximately 70 m (230 ft) wide, including a 15.3 m (50 ft) minimum 
space between the east and westbound bridge decks. The bridge decks 
will be side-by-side, except for the double deck portion between the 
existing Yerba Buena Island (YBI) tunnel and the transition structures 
where the double deck structure becomes two parallel structures. Each 
deck will consist of five traffic lanes and inside and outside 
shoulders. The traffic lanes will be 3.6 m (12 ft) wide with 3 m (10 
ft) wide shoulders. A bicycle/pedestrian path will be constructed on 
the south side of the eastbound structure and will be 4.7 m (15.5 ft) 
wide. The East Span Project would also replace the eastbound on-ramp on 
YBI. The existing ramp needs to be dismantled to construct the new 
bridge. The ramp would be rebuilt and would meet current design and 
safety standards.
    The foundations for the piers of the replacement East Span will 
consist of large diameter steel pipe piles that will be driven into the 
Bay floor. Current plans anticipate driving a total of 189 2.5 m (8.2 
ft) diameter piles and 70 1.8 m (5.9 ft) diameter steel pipe piles. 
Each pile is expected to consist of two or more segments; the first 
segment will be driven to an established depth, then the next 
segment(s) will be welded on and driven in succession until the pile is 
driven to its final or ``tip'' depth (or elevation). However, the 
contractor could choose to drive the piles in one piece. Some piles 
will be battered, meaning that they will be driven in at an angle, 
essentially splaying out from the pier to provide additional stability. 
The rest would be vertical piles. The larger piles will support the 
skyway and main span sections of the replacement bridge; they will be 
driven to depths ranging from about -66 m to about -108 m (-256 ft to -
358 ft), with most being driven to about -95 m (-312 ft). The smaller 
diameter piles will support the Oakland Touchdown structures; they will 
be driven to ``tip'' depth ranging from about -41 m to about -65 m (-
135 ft to -213 ft).
    Due to the untested nature of large hammers and piles in San 
Francisco Bay, a pile installation demonstration was conducted in 
October through December of 2000. This Pile Installation Demonstration 
Project (PIDP) was an investigation that provided an opportunity to 
gather information on construction activities and potential impacts to 
marine life. CALTRANS obtained an IHA from NMFS for the PIDP, which 
established a safety zone around each pile driving site where 
underwater sound pressure levels (SPLs) were anticipated to equal or 
exceed 190 decibels (dB) re 1 micro-Pascal (micro-Pa) with a maximum 
root mean square sound pressure level averaged over a 31 millisecond 
time frame (RMS (impulse)). This IHA also included several other 
stipulations about pile driving operations and requirements for marine 
mammal monitoring and reporting. During the PIDP, 3 large steel piles 
each required approximately 5 hours total driving time to reach the 
specified ``tip'' depth.
    Based on the PIDP experience, it is expected that the 259 in-Bay 
piles could require about 1,300 hours of total pile driving time. 
However, the contractor will be allowed to drive simultaneously at 
multiple locations. Furthermore, it is possible that piles necessary 
for the YBI portion, the skyway, and the Oakland approach structures 
would be driven simultaneously. Pile driving will be allowed only from 
7 AM to 7 PM, 7 days a week.
    In addition to in-Bay pile driving, the East Span Project will 
include pile driving on YBI for construction of the YBI transition 
structures on the northeastern side of the island. The piles will be 
steel driven piles, which are conventionally used in building 
construction. Unlike in-Bay pile driving which may require hammer 
energy levels up to 1,700 kiloJoules (kJ), pile driving activity on YBI 
will require hammer energy levels less than 100 kJ. A total of 
approximately 2,950 piles will be needed to support the YBI transition 
structures. Each pile will require about 30 minutes of driving time; 
therefore, it is estimated that the East Span Project will include a 
total of about 1,500 hours of driving time for piles on YBI.
    To construct all permanent structures, contractors will install 
piles to found temporary structures, supports, falsework, a barge dock 
and trestles. These temporary structures are required to facilitate 
construction and support the permanent structures until they are self-
supporting. Since the temporary structures will be contractor designed, 
their exact nature (size, type, quantity, etc.) will not be known until 
the contractors submit their plans to CALTRANS. While the number of 
piles placed to found the structures will be large, it is expected that 
they will be of a smaller size than the permanent structures since they 
are temporary and are not designed for traffic or seismic loading. 
There may be 1,000 to 2,000 temporary piles. These piles are expected 
to be 0.5 m (18 in) to 0.9 m (36 in) in diameter and 12 m (40 ft) to 30 
m (100 ft) long. Driving time for each pile is likely to be 3 to 5 
hours.
    The East Span Project would take 7 years to complete, plus 2 years 
to remove the existing East Span. Seismic safety and lifeline criteria 
would be achieved for westbound traffic 4 years after the start of 
construction and, for eastbound traffic, 5 years after the start of 
construction. Construction is scheduled to begin in early 2002. For 
more detailed description on the work proposed by CALTRANS, please 
refer to the CALTRANS application and/or the Final Environmental Impact 
Statement (FEIS) prepared by the Federal Highway Administration (FHWA).

Description of the Marine Mammals Potentially Affected by the 
Activity

    General information on California sea lions, Pacific harbor seals, 
gray whales and other marine mammal species found in California waters 
can be found in Forney et al. (2000) and Barlow et al. (1998). The 
marine mammals most likely to be found in the SF-OBB area are the 
California sea lion and Pacific harbor seal. From December through May 
gray whales may also be present in the SF-OBB area.

California Sea Lions

    While there is evidence that California sea lions historically used 
the Bay, they are rarely observed hauled out in the Bay (Bauer, 1999). 
However, since at least 1987, sea lions have been observed occupying 
the docks near Pier 39 in San Francisco, approximately 5.7 km (3.5 mi) 
from the project site. Pier 39 has now become a regular haul-out site 
for California sea lions. Currently, no other California sea lion haul-
out sites have been identified in the Bay. Approximately 85 percent of 
the animals hauled out at the Pier 39 site are males, and no pupping 
has been observed at this site or any other site in the Bay (Lander 
pers. comm. to CALTRANS, 1999).
    The number of California sea lions hauled out at Pier 39 ranged 
from 63 to 737 in 1998 and from 5 to 906 in 1997

[[Page 59003]]

(Marine Mammal Center, Sausalito data). For both years, the lows 
occurred in June and the highs occurred in August. Most recently, 831 
sea lions were observed on K dock at Pier 39 in October 1999. The trend 
in annual movement is for sea lions to first appear at the site after 
returning from the Channel Islands breeding area (over 483 km or 300 mi 
to the southwest) at the beginning of August (Bauer, 1999). Around late 
winter, the sea lions travel south to the breeding grounds, and numbers 
at the Bay haul-out site decline. The lowest numbers of sea lions at 
the Pier 39 haul-out are usually observed from May through July. 
However, the number of sea lions at the haul-out site fluctuates quite 
a bit throughout the year and even from one week to the next. For 
example, in June of 1998, a maximum of 574 sea lions was observed on 
June 7th while a low count of 63 was observed on June 
25th (Lander pers. comm. to CALTRANS, 1999).
    While little information is available on the foraging patterns of 
California sea lions in the Bay, individual sea lions have been 
observed feeding in the shipping channel to the south of YBI on a 
fairly regular basis (Grigg pers. comm. to CALTRANS, 1999). Foraging by 
sea lions that utilize the Pier 39 haul-out site primarily occurs in 
the Bay, where they feed on prey items such as Pacific herring, 
northern anchovy and sardines (Hanni, 1995).

Pacific Harbor Seals

    Pacific harbor seals are the only species of marine mammal that 
breed and bear young in the Bay (Howorth and Abbott, 1999). There are 
12 haul-out sites and rookeries in the Bay and of those, only eight are 
used by more than a few animals at a time. Only three sites in the Bay 
are regularly used by more than 40 harbor seals at any one time; these 
are Mowry Slough, located in the South Bay, YBI, and Castro Rocks, 
located in the Central Bay (Spencer, 1997). The three closest haul-out 
sites to the project location are at YBI, Angel Island, and Castro 
Rocks. The most recent aerial harbor seal count, conducted by D. Hanan 
of the California Department of Fish and Game, found 477 individuals in 
the Bay (Greene, pers. comm. to CALTRANS, 1999). It is important to 
note that not all harbor seals were counted, as some may have been 
under water during the survey.
    Harbor seals are present in the Bay year-round and use it for 
foraging, resting and reproduction. Peak numbers of hauled-out harbor 
seals vary by haul-out site depending on the season. Results of a study 
of 39 radio-tagged harbor seals in the Bay found that most active 
diving occurred at night and a majority of the diving time was spent in 
seven feeding areas in the Bay. The two feeding areas located closest 
to the project site are just to the south of YBI and north of Treasure 
Island. This study also found that the seals dove for a mean time of 
0.50 minutes to 3.33 minutes. Mean surface intervals or the mean time 
the seals spent at the surface between dives ranged from 0.33 minutes 
to 1.04 minutes. Mean haul-out periods ranged from 80 minutes to 24 
hours (Harvey and Torok, 1994).
    Pupping season in the Bay begins in mid-March and continues until 
about mid-May. Pups nurse for only 4 weeks and mating begins after pups 
are weaned. In the Bay, mating occurs from April to July and molting 
season is from June until August (Schoenherr, 1995; Kopec and Harvey, 
1995).

Pacific Harbor Seal Haul-Out Sites in the Vicinity of the East Span 
Project

    YBI is located in the Central Bay, adjacent to man-made Treasure 
Island. The SF-OBB passes through a tunnel on YBI. An important harbor 
seal haul-out is located on a rocky beach on the southwest side of YBI 
(Kopec and Harvey, 1995). Harbor seal re-sightings at the YBI haul-out 
site indicate long-term usage of the site (Spencer, 1997). Pile driving 
activity for the East Span Project will be performed on the northwest 
side of YBI and in the San Francisco Bay, between the northwest side of 
the island to the Oakland Touchdown area. The harbor seal haul-out site 
is located about 450 m (1,476 ft) from the closest planned pile driving 
activity on land and about 950 m (3,117 ft) from the closest planned 
pile driving activity in the Bay.
    Harbor seals haul out year-round on YBI, but it is not considered a 
pupping site as no births have been observed there. Occasionally, pups 
have been seen at an average of 1 pup per year, though more recently, 7 
pups were observed at one time in May, 1999 (San Francisco State 
University unpublished records, 1998-9). In a study of the haul-out 
site conducted between 1989 and 1992, males comprised 83.1 percent of 
the seals whose gender could be determined (Spencer, 1997). Peak 
numbers of harbor seals at this haul-out site have been observed from 
November to February. The maximum reported number of seals hauled out 
at one time is 344, counted in January 1992 (Kopec and Harvey, 1995). 
More recently, the number of seals counted at YBI ranged from 0 to 296 
for the period May 1998 to January 1999. Mean monthly counts for the 
same period range from approximately 15 in September 1998 to 107 in 
June 1999 (San Francisco State University, unpublished records 1998-
1999). The abundance of harbor seals at this site during the winter 
months likely coincides with the presence of spawning Pacific herring 
near the island.
    Angel Island is a small haul-out site located approximately 7.4 km 
(4.6 mi) from the project site. A maximum count of 15 seals was 
observed in the 1980s and most recently, six harbor seals were seen in 
1989. No pupping has been observed at the site.
    The next closest haul-out site in the Bay is approximately 14 km 
(8.7 mi) away at Castro Rocks, near the Richmond end of the Richmond-
San Rafael Bridge. The Castro Rocks haul-out site is a recognized 
pupping site. A maximum of 176 harbor seals were observed at Castro 
Rocks in October 1999 (San Francisco State University unpublished 
records, 1998-99).

Gray Whales

    The vast majority of all gray whales are found in the Pacific Ocean 
along the western coastline of North America. Here, they spend their 
winters in the waters off Baja California and migrate more than 9,000 
kilometers (5,600 miles) north to spend their summers north of Alaska. 
They are typically seen off the California coastline from December 
through May as they migrate northward to the Bering and Chukchi Seas, 
and again in the return trip to Baja California.
    Gray whales have been sighted more frequently in recent years in 
San Francisco Bay. Reduced food supply in the Bering Sea has been 
suspected as the most probable cause. Gray whales have been sighted in 
the Bay in areas off Sausalito in Richardson Bay and the tip of the 
Tiburon Peninsula (approximately 11 km or 7 mi northwest of the project 
area) and as far south as the San Bruno Shoals area (approximately 23 
km or 14 mi southwest of the project area). Gray whales have been 
observed foraging in these areas. Sightings in the Bay have typically 
been made from December through May, during the whales' coastal 
migration. Calves may be expected during the migration north with 
mothers in March and May. Most recently, in February 2001, a pod of 
gray whales was observed near the Dumbarton Bridge in the South Bay.
    Gray whales heading to the San Bruno Shoals area would pass beneath 
the SF-OBB. It is likely that some of the whales that enter the Bay 
would swim through the two deep-water shipping channels beneath the 
West Spans of the bridge.

[[Page 59004]]

 Though the number of sightings of gray whales to the east of YBI and 
in the immediate vicinity of the SF-OBB are low, they are not precluded 
from swimming there to reach the San Bruno Shoals area or foraging near 
or in these areas in the future.

Potential Effects on Marine Mammals and Their Habitat

    At this time, NMFS considers that underwater SPLs above 190 dB re 1 
micro-Pa RMS (impulse) could cause temporary hearing impairment (Level 
B harassment) in harbor seals and sea lions and SPLs above 180 dB re 1 
micro-Pa RMS (impulse) could cause temporary hearing impairment (Level 
B harassment) in whales (Fahy, personal communication 2001). The 
effects of elevated SPLs on marine mammals may include avoidance of an 
area, tissue rupture, hearing loss, disruption of echolocation, 
masking, habitat abandonment, aggression, pup/calf abandonment, and 
annoyance. Therefore, CALTRANS has determined that the pile driving 
outlined in the project description has the potential to harass 
California sea lions, Pacific harbor seals, and gray whales that may be 
swimming, foraging, or resting in the project vicinity.
    During the 2-month PIDP construction period, sound measurements 
were taken during pile driving of three piles, and marine mammals were 
monitored at the project site and at the harbor seal haul-out site on 
YBI. Results of observable effects of the PIDP on marine mammals is 
summarized in the Marine Mammal Impact Assessment Report prepared by 
CALTRANS in August 2001 (CALTRANS 2001). More specifically, the 
demonstration provided CALTRANS an opportunity to measure resulting 
SPLs both in air and under water, record impacts to marine mammals and 
experiment with measures to reduce harm to marine mammals. Sixty-eight 
pinnipeds (55 harbor seals and 13 sea lions) were sighted during 
monitoring activities. Of this total, 57 pinnipeds (47 harbor seals and 
10 sea lions) were seen during non-pile driving activities. Only eight 
harbor seals and three sea lions were observed near the PIDP site 
during actual pile driving, which totaled 12 hours and 51 minutes. In 
addition, up to 85 harbor seals per monitoring period hauled out at the 
semi-protected cove on the southwestern side of YBI, approximately 
1,500 m (4,920 ft) from the pile-driving area. No gray whales were 
observed.
    The East Span Project is not expected to result in any significant 
impacts to marine mammal habitat. Short-term impacts will include the 
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.

California Sea Lions

    Of the 13 total sea lions observed during the PIDP construction 
period, three individual sea lions were observed in the PIDP 
construction site within and beyond the 500-m (1,640-ft) safety zone 
during the actual driving of piles. The three sea lions rapidly swam 
and porpoised out of the area when pile driving began, indicating 
possibly: (1) increased sensitivity to the pile driving noise in air 
and/or water, (2) less conditioning to anthropogenic noise, or (3) a 
difference of the level of sound received by the sea lions resulting 
from varying human, environmental (ambient) and hammer magnitude or 
conditions at the time of pile driving. Alternatively, since the three 
sea lions were present at the start of pile driving, their response 
could indicate that they were startled by the noise (SRS Technologies, 
2001). The frequency and duration of the noise and whether underwater 
or airborne sounds start suddenly or gradually, creating a ramping 
effect (as usually performed for the PIDP), may also influence the 
behavior of these mammals. However, none of these factors could be 
explored in detail within the scope of the demonstration project.
    Noise levels from the East Span project within and beyond a 500-m 
(1,640-ft) safety zone are not expected to result in harassment of the 
sea lions hauled out at Pier 39 as SPLs would attenuate to below 
harassment levels by the time they reach the haul-out site, 5.7 
kilometers (3.5 miles) from the project site.

Pacific Harbor Seals

    The Richmond Bridge Harbor Seal Survey is currently gathering data 
on harbor seals at the Castro Rocks and YBI haul-out sites as part of 
the San Rafael-Richmond Bridge Seismic Retrofit Project monitoring 
program (see 66 FR 49165, September 26, 2001). A total of 55 harbor 
seals were observed in the vicinity of the PIDP site during the 2\1/2\-
month construction period. Of this total, 47 were observed during non-
pile driving activities and eight harbor seals were observed during 
actual pile driving. The eight harbor seals, which were sighted within 
the 500 m (1,640 ft) safety zone, seemed to observe the activities 
around the barge during pile driving while swimming in and out of the 
safety zone, but did not show any avoidance response during pile 
driving. Additional observations during the PIDP showed that harbor 
seals at YBI increased in number during low tide, and responded to 
activities unrelated to pile driving activities such as helicopter 
noise, boat traffic and kayakers, with head alerts or flushing of the 
site when startled or disturbed.
    Pile driving could potentially harass those harbor seals that are 
in the water closer to the project site, whether their heads are above 
or below the surface. Since no response was observed from harbor seals 
in the water at YBI during the PIDP project except for initial reaction 
from airborne noise during driving of unattenuated Pile 1A, it is 
likely that underwater SPLs resulting from pile driving activity at a 
distance of about 1,500 m (4,920 ft) or greater would be sufficiently 
attenuated at the haul-out site. It is unknown whether piles driven 
closer to YBI would result in underwater SPLs that would disturb harbor 
seals at the haul-out site. It is estimated that a fraction of the 
seals hauled out at YBI would potentially be in the water and close to 
the project site during pile driving activities. Potential harassment 
would only occur during those times when piles are being hammered, 
which will include a total of approximately 1,300 hours of in-Bay pile 
driving and approximately 1,500 hours of pile driving on YBI over the 
9-year construction period. The number of harbor seals that could 
potentially be harassed during the East Span Project would vary based 
on the location of pile driving activity and the proximity of the seals 
to the pile driving site.
    Harbor seals on the YBI haul-out site are commonly subjected to 
high levels of disturbance, primarily from watercraft. This is 
particularly true during the summer, when the numbers of small boats, 
jet skis, kayaks, etc., in San Francisco Bay increase (San Francisco 
State University, 1999b). Abandonment of the haul-out site is not 
anticipated as sound levels from pile driving, both in water and in 
air, are expected to attenuate sufficiently by the time they reach the 
site. Although harbor seal pups have been observed at the YBI haul-out 
site, it is not a recognized pupping site. Therefore, no significant 
impacts on species recruitment are anticipated.

[[Page 59005]]

Gray Whales

    No gray whales were observed during the PIDP. However, gray whales 
can be expected in the Bay in increasing numbers from December through 
May during their winter migration to and from Alaska. Noise from the 
pile driving activities therefore may affect gray whales swimming 
toward the southern San Bruno Shoals region.
    Behavioral responses of gray whales to noise can include avoidance, 
startle response, and complete abandonment of an area. Noise may elicit 
short-term disruptions of normal activities similar to seals, such as 
startle response, agitation, stress, and cessation of foraging 
activities. Most evidence suggests that whales will avoid loud noises, 
which may result in a temporary displacement of the animal from typical 
foraging or traveling areas. Although it is uncertain whether gray 
whales will be affected by SPLs generated by pile driving during the 
East Span Project, observations and research from the past 3 years 
(1999-2001) indicate that fewer than 10 gray whales have been sighted 
in the Bay on any particular day (Oliver personal communication, 2001). 
The number of gray whales present in the Bay may increase in the 
future, since in recent years there have been more frequent sightings 
of gray whales in the Bay during their migration period. Whether these 
whales will be in close proximity to the construction area for any 
period of time is unknown at this time. The primary concern is for 
whales passing by YBI on the west or east sides while traveling to San 
Bruno Shoals.

Mitigation

Establishment of Safety/Buffer Zones

    Prior to commencement of any pile driving, a preliminary 500-m 
(1,640-ft) radius safety zone for pinnipeds (California sea lions and 
Pacific harbor seals) will be established around the pile driving site, 
as it was for the PIDP. The safety zone is intended to include all 
areas where the underwater SPLs are anticipated to equal or exceed 190 
dB re 1 mPa RMS (impulse). Once pile driving begins, SPLs will be 
recorded at the 500-m (1,640-ft) contour. The safety zone radius for 
pinnipeds will then be enlarged or reduced, depending on the actual 
recorded SPLs. A 180-dB re 1 mPa RMS (impulse) safety zone for gray 
whales will be established for pile driving occurring during the gray 
whale migration season from December through May.
    Observers on boats will 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 will be delayed until they move out of the 
area. If a marine mammal is seen above water and then dives below, the 
contractor will wait 15 minutes and if no marine mammals are observed 
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). Due to the 
limitations of monitoring from a boat, there can be no assurance that 
the zone will be devoid of all marine mammals.
    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 San Francisco 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 
resting in highly resistant sediment layers. Therefore, because of this 
operational situation, if marine mammals enter the safety zone after 
pile driving of a segment has begun, pile driving will continue and 
marine mammal observers will monitor and record their numbers and 
behavior.
    A 500-m (1,640-ft) no-entry buffer zone will be established around 
the haul-out site on YBI to minimize the impact of project-related 
vessel traffic during the East Span Project on marine mammals. This 
buffer zone will be established in coordination with the U.S. Coast 
Guard (USCG). The buffer zone will be delineated with USCG-compliant 
brightly colored temporary buoys. CALTRANS will establish strict 
standards on vessel speed for all project-related crafts traveling in 
the Bay.

Compliance with Equipment Noise Standards

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

Barrier Systems

    CALTRANS proposes to utilize a ``marine pile-driving energy 
attenuator'' during all pile driving activities in an attempt to reduce 
overall sound levels (Mara Melandry, personal communication 2001). This 
attenuator system would consist of an air bubble curtain, similar to 
the system tested during the PIDP. The PIDP air bubble attenuator 
system consisted of a piping system ring that was submerged to the Bay 
floor where it encircled the pile template and was supplied air from a 
compressor at the surface. Wursig et al. (2000) used a similar system 
for attenuating noise received by dolphins during pile driving 
activities for an airport expansion.

Monitoring

    Before issuance of an IHA, a mammal monitoring plan must be 
prepared and approved by NMFS prior to the start of the East Span 
Project. The complete monitoring plan must include: (1) a description 
of the proposed survey techniques that would be used to determine the 
movement and activity of marine mammals near the construction areas; 
and (2) scientific rigor that will allow NMFS to verify that any 
impacts on marine mammal populations from this specific activity are 
small in number and negligible.

Visual Observations

    NMFS will require safety zone monitoring during all active pile 
driving and for a period of time (yet to be established) before the 
entire East Span Project begins. Monitoring of the pinniped and 
cetacean safety zones will be conducted by a minimum of three qualified 
NMFS-approved observers for each safety zone. The observers will begin 
monitoring at least 30 minutes prior to startup of the pile driving. 
Observers will likely conduct the monitoring from small boats, as 
observations from a higher vantage point (such as the SF-OBB) may not 
be practical. Pile driving will not begin until the safety zone is 
clear of marine mammals. But, 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.
    Biological observations will be made using binoculars during 
daylight hours. In addition to monitoring from boats, monitoring of the 
YBI haul-out may be conducted during pile driving activity, in 
coordination with the Richmond

[[Page 59006]]

Bridge Harbor Seal survey team. NMFS will also require one or more 
control sites (harbor seal haul-out sites and the waters surrounding 
such sites not impacted by the East Span Project's pile driving 
activities, i.e. Mowry Slough) be designated and monitored for 
comparison. All observations will be recorded and will include items 
such as species, numbers, behavior, details of any observed 
disturbances, time of observation, location, and weather.

Acoustical Observations

    Both airborne and underwater environmental noise levels will 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 gray whales. 
Monitoring will be conducted during the driving of the last half 
(deepest pile segment) for any given pile. One pile in every other pair 
of pier groups will be monitored. One reference location will be 
established at a depth of 100 m (328 ft). Sound levels will be measured 
during the entire driving session at the reference location. Additional 
spot measurements will be conducted at appropriate depths (near mid 
water column) 500 m (1,640 ft) distance at two locations west and 
north. 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.
    Airborne sound levels will be measured at times and locations that 
are coincidental to the underwater measurement sights. Each system will 
consist of a type 1 integrating sound level meter connected to a DAT. 
In addition, airborne sound will also be measured at the YBI haul-out 
site. Real time amplitude measurement of airborne sound levels will be 
reported. Linear Peak and RMS impulse SPLs will be reported. 
Microphones will be fitted with windscreens and calibration will be 
verified before and after each measurement session. The recorded data 
will be analyzed to determine the amplitude, time history and frequency 
content of the impulse.

Reporting

    NMFS' Southwest Regional Administrator will be notified prior to 
the initiation of the East Span Project, and coordination with NMFS 
will occur on a weekly basis, or more often as necessary. NMFS will be 
informed of the initial SPL measurements taken at the 500-m (1,640-ft) 
contour and the final safety-zone radius established. Monitoring 
reports will be faxed to NMFS on a monthly basis during pile driving 
activity. The monthly report will include a summary of the previous 
month's 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.
    Because the East Span Project is expected to continue beyond the 
date of expiration of this IHA (under a new IHA or under regulations 
pursuant to section 101(a)(5)(A) of the MMPA), CALTRANS will provide 
NMFS' Southwest Regional Administrator with a draft final report before 
90 days after expiration of this IHA. 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 comments are received from the Regional 
Administrator on the draft final report, a final report must be 
submitted to NMFS within 30 days. If no comments are received from 
NMFS, the draft final report will be considered to be the final report.

Preliminary Conclusions

    NMFS has determined that the short-term impact of pile driving and 
other activities associated with the East Span Project, as described in 
this document, should result, at worst, in the temporary modification 
in behavior of California sea lions and Pacific harbor seals, and 
potentially gray whales. While behavioral modifications, including 
temporarily vacating haul-out sites and other areas, may be made by 
these species to avoid the resultant visual and acoustic disturbance, 
the availability of alternate haul-out sites (including pupping sites) 
and feeding areas within the Bay has led NMFS to the preliminary 
conclusion that this action will have a negligible impact on California 
sea lion, Pacific harbor seal, and gray whale populations along the 
California coast.
    In addition, no take by 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.

Proposed Authorization

    NMFS proposes to issue an IHA to CALTRANS for the potential 
harassment of small numbers of California sea lions, Pacific harbor 
seals, and gray whales incidental to construction of a replacement 
bridge for the East Span of the SF-OBB provided the previously 
mentioned mitigation, monitoring, and reporting requirements are 
incorporated.

Information Solicited

    NMFS requests interested persons to submit comments, information, 
and suggestions concerning this proposed authorization to Donna 
Wieting, Chief, Marine Mammal Conservation Division, Office of 
Protected Resources, NMFS, 1315 East-West Highway, Silver Spring, MD 
20910-3225.

    Dated: November 19, 2001.
David Cottingham,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 01-29391 Filed 11-23-01; 8:45 am]
BILLING CODE 3510-22-S