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Small Takes of Marine Mammals Incidental to Specified Activities; Seismic Retrofit of the Richmond-San Rafael Bridge, San Francisco Bay, CA

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


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


NMFS has received a request from the California Department of Transportation (CALTRANS) for a renewal of its Incidental Harassment Authorization (IHA) to take small numbers of marine mammals, by harassment, incidental to seismic retrofit construction of the Richmond-San Rafael Bridge (the Bridge), San Francisco Bay (the Bay), CA. Under the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposal to renew a small take authorization to CALTRANS to incidentally take, by harassment, small numbers of Pacific harbor seals and possibly California sea lions for 1 year.


Comments and information must be received no later than August 22, 2001.


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 may be obtained by writing to this address or by telephoning one of the contacts listed here. Comments cannot be accepted if submitted via e-mail or the Internet.

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Kenneth R. Hollingshead, Office of Protected Resources, NMFS, (301) 713-2055, or Christina Fahy, Southwest Regional Office, NMFS, (562) 980-4023.

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Sections 101 (a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) directs the Secretary of Commerce to allow, upon request, the incidental, but not intentional, taking of marine mammals by U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region if certain findings are made and either regulations are issued or, if the taking is limited to harassment, a notice of a proposed authorization is provided to the public for review.

Permission may 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 subsistence uses and that the permissible methods of taking and requirements pertaining to the monitoring and reporting of such takings are set forth. NMFS has defined “negligible impact” in 50 CFR 216.103 as “ 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; 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.

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 June 8, 2001, NMFS received a letter from CALTRANS, requesting reauthorization of an IHA that was first issued to it on December 16, 1997 (62 FR 6704, December 23, 1997), and renewed on January 8, 2000 (65 FR 2375, January 14, 2000), with an effective date for the IHA beginning on Start Printed Page 38259September 1, 2000, and expiring on August 31, 2001. The renewed authorization would be for the possible harassment of small numbers of Pacific harbor seals (Phoca vitulina) and possibly some California sea lions (Zalophus californianus), incidental to seismic retrofit construction of the Bridge.

The Bridge is being seismically retrofitted to withstand a future severe earthquake. Construction is scheduled to extend until the year 2005. A detailed description of the work planned is contained in the Final Natural Environmental Study/Biological Assessment for the Richmond-San Rafael Bridge Seismic Retrofit Project (CALTRANS, 1996). Among other things, seismic retrofit work will include excavation around pier bases, hydro-jet cleaning, installation of steel casings around the piers with a crane, installation of micro-piles, and installation of precast concrete jackets. Foundation construction will require approximately 2 months per pier, with construction occurring on more than one pier at a time. In addition to pier retrofit, superstructure construction and tower retrofit work will also be carried out. Because seismic retrofit construction between piers 52 and 57 has the potential to disturb harbor seals hauled out on Castro Rocks, an IHA is warranted. The duration for the seismic retrofit of foundation and towers on piers 52 through 57, which has not taken place as of this date, will take approximately 7 to 8 months to complete.

Description of Habitat and Marine Mammals Affected by the Activity

A description of the Bay ecosystem and its associated marine mammals can be found in the CALTRANS application (CALTRANS 1997) and in CALTRANS (1996).

Castro Rocks are a small chain of rocky islands located next to the Bridge and approximately 1500 ft (460 m) north of the Chevron Long Wharf. They extend in a southwesterly direction for approximately 800 ft (240 m) from pier 55. The rocks start at about 55 ft (17 m) from pier 55 and end at approximately 250 ft (76 m) from pier 53. The chain of rocks is exposed during low tides and inundated during high tide.

Marine Mammals

General information on harbor seals and other marine mammal species found in Central California waters can be found in Forney et al. (2000). The marine mammals likely to be found in the Bridge area are limited to California sea lions and harbor seals.

The California sea lion primarily uses the Central San Francisco Bay area to feed. California sea lions are periodically observed at Castro Rocks. No pupping or regular haulouts occur in the project area.

The harbor seal is the only marine mammal species expected to be found regularly in the Bridge area. A detailed description of harbor seals was provided in the 1997 notification of proposed authorization (62 FR 46480, September 3, 1997) and is not repeated here. Corrections and clarifications to the first IHA were provided in the notice of IHA issuance (62 FR 67045, December 23, 1997). Additional information on harbor seals in San Francisco Bay, impacts on harbor seals, and on mitigation and monitoring of the activity were provided in the 2000 IHA authorization document (65 FR 2375, January 14, 2000).

Potential Effects on Marine Mammals

The impact to the harbor seals and California sea lions is expected to be disturbance by the presence of workers, construction noise, and construction vessel traffic. Disturbance from these activities is expected to have a short-term negligible impact to a small number of harbor seals and sea lions. These disturbances will be reduced to the lowest level practicable by implementation of the proposed work restrictions and mitigation measures (see Mitigation).

During the work period, the incidental harassment of harbor seals and, on rare occasions, California sea lions is expected to occur on a daily basis upon initiation of the retrofit work. If harbor seals no longer perceive construction noise and activity as being threatening, they are likely to resume their regular haul out behavior. The number of seals disturbed will vary daily depending upon tidal elevations. It is expected that disturbance to harbor seals during peak periods of abundance will not occur since construction activities will not take place within the restricted work area during the peak period (see Mitigation).

Whether California sea lions will react to construction noise and move away from the rocks during construction activities is unknown. Sea lions are generally thought to be more tolerant of human activities than harbor seals and are, therefore, less likely to be affected.

Potential Effects on Habitat

Short-term impacts of the activities are expected to result in a temporary reduction in utilization of the Castro Rocks haulout site while work is in progress or until seals acclimate to the disturbance. This will not likely result in any permanent reduction in the number of seals at Castro Rocks. The abandonment of Castro Rocks as a harbor seal haulout and rookery is not anticipated since existing traffic noise from the Bridge, commercial activities at the Chevron Long Wharf used for off-loading crude oil, and considerable recreational boating and commercial shipping that currently occur within the area have not caused long-term abandonment. In addition, mitigation measures and proposed work restrictions are designed to preclude abandonment.

Therefore, as described in detail in CALTRANS (1996), other than the potential short-term abandonment by harbor seals of part or all of Castro Rocks during retrofit construction, no impact on the habitat or food sources of marine mammals are likely from this construction project.


Several mitigation measures to reduce the potential for general noise will be implemented by CALTRANS as part of their activity. General restrictions include: with the exception of the Concrete Trestle Section, no piles will be driven (i.e., no repetitive pounding of piles) on the Bridge between 9 p.m. and 7 a.m.; an imposition of a construction noise limit of 86 dBA at 50 ft (15 m) between 9 p.m. and 7 a.m.; and, a limitation on construction noise levels for 24 hrs/day in the vicinity of Castro Rocks during the pupping/molting restriction period (February 15 through July 31).

To minimize potential harassment of marine mammals, NMFS proposes to require CALTRANS to comply with the following mitigation measures: (1) A February 15 through July 31 restriction on work in the water south of the Bridge center line and retrofit work on the Bridge substructure, towers, superstructure, piers, and pilings from piers 52 through 57; (2) no watercraft will be deployed by CALTRANS employees or contractors, during the year within the exclusion zone located between piers 52 and 57, except for when construction equipment is required for seismic retrofitting of piers 52 through 57; and (3) minimize vessel traffic to the greatest extent practicable in the exclusion zone when conducting construction activities between piers 52 and 57. The boundary of the exclusion zone is rectangular in shape (1700 ft (518 m) by 800 ft (244 m)) and completely encloses Castro Rocks and piers 52 through 57, inclusive. The northern boundary of the exclusion zone will be located 300 ft (91 m) from the most northern tip of Castro Rocks, Start Printed Page 38260and the southern boundary will be located 300 ft (91 m) from the most southern tip of Castro Rocks. The eastern boundary will be located 300 ft (91 m) from the most eastern tip of Castro Rocks, and the western boundary will be located 300 ft (91 m) from the most western tip of Castro Rocks. This exclusion zone will be restricted as a controlled access area and will be marked off with buoys and warning signs for the entire year.


NMFS will require CALTRANS to monitor the impact of seismic retrofit construction activities on harbor seals at Castro Rocks. Monitoring will be conducted by one or more NMFS-approved monitors. CALTRANS is to monitor at least one additional harbor seal haulout within San Francisco Bay to evaluate whether harbor seals use alternative haulout areas as a result of seismic retrofit disturbance at Castro Rocks.

The monitoring protocol will be divided into the Work Period Phase (August 1 through February 14) and the Closure Period Phase (February 15 through July 31). During the Work Period Phase and Closure Period Phase, the monitor(s) will conduct observations of seal behavior at least 3 days/week for approximately one tidal cycle each day at Castro Rocks. The following data will be recorded: (1) Number of seals and sea lions on site; (2) date; (3) time; (4) tidal height; (5) number of adults, subadults, and pups; (6) number of individuals with red pelage; (7) number of females and males; (8) number of molting seals; and (9) details of any observed disturbances. Concurrently, the monitor(s) will record general construction activity, location, duration, and noise levels. At least 2 nights/week, the monitor will conduct a harbor seal census after midnight at Castro Rocks. In addition, during the Work Period Phase and prior to any construction between piers 52 and 57, inclusive, the monitor(s) will conduct baseline observations of seal behavior at Castro Rocks and at the alternative site(s) once a day for a period of 5 consecutive days immediately before the initiation of construction in the area to establish pre-construction behavioral patterns. During the Work Period and Closure Period Phases, the monitor(s) will conduct observations of seal behavior, and collect appropriate data, at the alternative Bay harbor seal haulout at least 3 days/week (Work Period) and 2 days/week (Closure Period), during a low tide.

In addition, NMFS proposes to require that, immediately following the completion of the seismic retrofit construction of the Bridge, the monitor(s) will conduct observations of seal behavior, at Castro Rocks, at least 5 days/week for approximately 1 tidal cycle (high tide to high tide) each day, for one week/month during the months of April, July, October, and January. At least 2 nights/week during this same period, the monitor will conduct an additional harbor seal census after midnight.


CALTRANS will provide weekly reports to the Southwest Regional Administrator (Regional Administrator), NMFS, including a summary of the previous week's monitoring activities and an estimate of the number of harbor seals that may have been disturbed as a result of seismic retrofit construction activities. These reports will provide dates, time, tidal height, maximum number of harbor seals ashore, number of adults, sub-adults and pups, number of females/males, number of harbor seals with a red pelage, and any observed disturbances. A description of retrofit activities at the time of observation and any sound pressure levels measurements made at the haulout will also be provided. A draft interim report must be submitted to NMFS by April 30, 2002.

Because seismic retrofit activities are expected to continue beyond the date of expiration of this IHA (presumably under a new IHA), a draft final report must be submitted to the Regional Administrator within 90 days after the expiration of this IHA. A final report must be submitted to the Regional Administrator within 30 days after receiving comments from the Regional Administrator on the draft final report. If no comments are received from NMFS, the draft final report will be considered to be the final report.

CALTRANS will provide NMFS with a follow-up report on the post-construction monitoring activities within 18 months of project completion in order to evaluate whether haulout patterns are similar to the pre-retrofit haul-out patterns at Castro Rocks.

National Environmental Policy Act

NMFS prepared an Environmental Assessment (EA) in 1997 that concluded that the impacts of CALTRANS' seismic retrofit construction of the Bridge will not have a significant impact on the human environment. A copy of that EA, which includes the Finding of No Significant Impact is available upon request (see ADDRESSES).

Preliminary Conclusions

NMFS has preliminarily determined that the short-term impact of the seismic retrofit construction of the Bridge, as described in this document, should result, at worst, in the temporary modification in behavior by harbor seals and, possibly, by some California sea lions. While behavioral modifications, including temporarily vacating the haulout, may be made by these species to avoid the resultant visual and acoustic disturbance, this action is expected to have a negligible impact on the animals. In addition, no take by injury and/or death is anticipated, and harassment takes will be at the lowest level practicable due to incorporation of the mitigation measures mentioned previously in this document.

Proposed Authorization

NMFS proposes to renew an IHA to CALTRANS for the potential harassment of small numbers of harbor seals and California sea lions incidental to seismic retrofit construction of the Bridge, provided the previously mentioned mitigation, monitoring, and reporting requirements are incorporated. NMFS has preliminarily determined that the proposed activity would result in the harassment of only small numbers of harbor seals and possibly California sea lions and will have no more than a negligible impact on these marine mammal stocks.

Information Solicited

NMFS requests interested persons to submit comments, information, and suggestions concerning this request (see ADDRESSES).

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Dated: July 17, 2001.

Wanda L. Cain,

Acting Deputy Director, Office of Protected Resources, National Marine Fisheries Service.

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[FR Doc. 01-18322 Filed 7-20-01; 8:45 am]