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

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 010599B]

Small Takes of Marine Mammals Incidental to Specified Activities;

Seismic Retrofit of the Richmond-San Rafael Bridge, San Francisco Bay,

CA

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 renewal of an authorization to take small

numbers of Pacific harbor seals and possibly California sea lions by

harassment incidental to seismic retrofit construction of the Richmond-

San Rafael Bridge, San Francisco Bay, CA (the Bridge). Under the Marine

Mammal Protection Act (MMPA), NMFS is requesting comments on its

proposal to reauthorize CALTRANS to incidentally take, by harassment,

small numbers of marine mammals in the above mentioned area for a

period of 1 year.

DATES: Comments and information must be received no later than March

18, 1999.

ADDRESSES: Comments on the application should be addressed to the

Chief, Marine Mammal Division, Office of Protected Resources, NMFS,

1315 East-West Highway, Silver Spring, MD 20910-3225. A copy of the

application, an Environmental Assessment (EA) and a list of references

cited in this document may be obtained by writing to this address or by

telephoning one of the contacts listed here.

FOR FURTHER INFORMATION CONTACT: Kenneth R. Hollingshead, Office of

Protected Resources, NMFS, (301) 713-2055, or Irma Lagomarsino,

Southwest Regional Office, NMFS, (562) 980-4016.

SUPPLEMENTARY INFORMATION:

Background

Section 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 `` ...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 now 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.

[[Page 7628]]

Summary of Request

On November 9, 1998, NMFS received an application from CALTRANS,

requesting reauthorization of an Incidental Harassment Authorization

(IHA) issued on December 16, 1997 (62 FR 6704, December 23, 1997). This

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 through December

2001. A detailed description of the work planned is contained in

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. The construction duration for the seismic retrofit of

foundation and towers on piers 52 through 57 will be approximately 7 to

8 months.

Although the seismic retrofit construction between piers 52 and 57

did not take place during 1998, because this work may potentially

result in disturbance of pinnipeds at Castro Rocks, reauthorization of

the IHA is warranted.

Description of Habitat and Marine Mammals Affected by the Activity

A description of the San Francisco Bay ecosystem and its associated

marine mammals can be found in the CALTRANS application (CALTRANS 1997)

and 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 Barlow et al.

(1995). The marine mammals likely to be found in the Bridge area are

limited to the California sea lion and harbor seal.

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 found in the

Bridge area in significant numbers. A detailed description of harbor

seals was provided in the 1997 notice of proposed authorization (62 FR

46480, September 3, 1997) and is not repeated here. Corrections and

clarifications to the proposed authorization were provided in the

notice of IHA issuance (62 FR 67045, December 23, 1997).

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 by

implementation of the proposed work restrictions and mitigation

measures (see Mitigation).

During the work period, harbor seal and, on rare occasions,

California sea lion incidental harassment 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 hauling 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, likely to be less affected.

Potential Effect on Habitat

Short-term impacts of the activities are expected to result in a

temporary reduction in utilization of the Castro Rocks haul out 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

haul out 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.

Mitigation

Several mitigation measures to reduce the potential for general

noise will be implemented by CALTRANS as part of their proposed

activity. General restrictions include: 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.

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 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 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 250 ft (76 m) from the most northern tip of Castro Rocks,

and the southern boundary will be located 250 ft (76 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

[[Page 7629]]

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.

Monitoring

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 hauling-out 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 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 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 at the alternative San Francisco 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 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, the monitor will conduct an additional

harbor seal census after midnight.

Reporting

NMFS proposes to require CALTRANS to provide weekly reports to the

Southwest Regional Administer, 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 and sub-adults, number of females/males, number of redcoats, 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 final report must be submitted to the Southwest Regional

Administrator no less than 90 days before the expiration of the

CALTRANS IHA. A final report must be submitted to the Southwest

Regional Administrator within 30 days after receiving comments from the

Regional Administrator on the draft 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 haul-out patterns are similar

to the pre-retrofit haul-out patterns at Castro Rocks.

National Environmental Policy Act

NMFS prepared an 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 is

available upon request (see ADDRESSES).

Conclusions

NMFS has preliminarily determined that the short-term impact of a

seismic retrofit construction of the Bridge will result, at worst, in a

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 noise, this action is expected to have a negligible

impact on the animals. In addition, no take by injury and/or death is

anticipated, and takes will be at the lowest level practicable due to

incorporation of the mitigation measures mentioned earlier in this

document.

Proposed Authorization

NMFS proposes to issue an incidental harassment authorization to

CALTRANS for the possible harassment of small numbers of harbor seals

and California sea lions incidental to seismic retrofit construction of

the Bridge, provided the above mentioned mitigation, monitoring, and

reporting requirements are incorporated. NMFS has preliminarily

determined that the proposed activities 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).

Dated: February 9, 1999.

P. Michael Payne,

Acting Deputy Director, Office of Protected Resources, National Marine

Fisheries Service.

[FR Doc. 99-3681 Filed 2-12-99; 8:45 am]

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