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. 080897A]

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 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) 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) has been issued to the California

Department of Transportation (Caltrans) for a period of 1 year.

DATES: This authorization is effective from December 16, 1997, through

December 15, 1998.

ADDRESSES: The application, authorization, and environmental assessment

(EA), and a list of references used in this document are available by

writing to the following offices: Marine Mammal Division, Office of

Protected Resources, NMFS, 1315 East-West Highway, Silver Spring, MD

20910-3225, or the Southwest Region, NMFS, 501 West Ocean Blvd., Suite

4200, Long Beach, CA 90802, or by telephoning one of the following

contacts.

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 (Secretary) 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, 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), will not have an

unmitigable adverse impact on the availability of the species or

stock(s) for subsistence uses, and 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.''

Section 101(a)(5)(D) of the MMPA provides 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

[[Page 67046]]

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) provides 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 July 7, 1997, NMFS received an application from Caltrans,

requesting an authorization 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. Accordingly, NMFS published a

notice in the Federal Register on September 3, 1997 (62 FR 46480),

requesting comments on NMFS' proposal to authorize Caltrans, under

section 101(a)(5)(D) of the MMPA, to take, by harassment, small numbers

of marine mammals incidental to seismic retrofit construction of the

Bridge.

The Bridge will be seismically retrofitted to withstand a future

severe earthquake. Construction is scheduled to begin in December 1997

and extend through December 2001. A detailed description of the work

planned is contained in Caltrans' 1996 Final Natural Environmental

Study/Biological Assessment for the Richmond-San Rafael Bridge Seismic

Retrofit Project. 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. Because of work restrictions and mitigation measures, the

seismic retrofit construction in this area is expected to be completed

within two authorized work periods.

As the seismic retrofit construction between Piers 52 and 57 may

potentially result in disturbance of pinnipeds at Castro Rocks, an MMPA

authorization is warranted.

Comments and responses

A notice of receipt of the application and proposed authorization

was published on September 3, 1997 (62 FR 46480), and a 30-day public

comment period was provided on the application and proposed

authorization. In addition a press release was issued on September 10,

1997, and a public notice was published in a newspaper of general

circulation in the San Francisco Bay area. During the comment period,

comments were received from the Marine Mammal Commission (MMC),

Caltrans, and the California Law Project (CLP). Information on the

activity and authorization request that are not subject to reviewer

comments can be found in the proposed authorization notice and is not

repeated here.

Comments on MMPA Authorizations

Comment 1: CLP was of the opinion that the purpose and intent of

the IHA provision in section 101(a)(5)(D) of the MMPA is to allow

incidental marine mammal taking when the harassment will be ``short-

term and non-lethal.'' Because neither the Caltrans application nor the

EA made clear that the seismic retrofit project would have ``short-term

and non-lethal'' impacts to harbor seals, a section 101(a)(5)(D)

authorization under the MMPA would be inappropriate. CLP notes that the

project would extend beyond the 1-year time limit specified in section

101(a)(5)(D) and that subsequent renewals would be necessary. CLP notes

that Congress intended that projects of this length (up to 5

consecutive years) be permitted under the more protective provisions of

section 101(a)(5)(A).

Response: NMFS does not agree. When implementing section

101(a)(5)(D) in 1994, the House of Representatives noted: ``It is not

the Committee's intent to weaken any of the existing standards which

protect marine mammals and their habitats from incidental takes under

this section. However, the Committee recognizes that the regulatory

agencies must be afforded some procedural flexibility in order to

streamline the review of authorizations under this section.'' (H. Rept.

103-439, 103rd Congress, 2nd Sess., pp. 29, 30.) Provided the taking is

not expected to result in the serious injury or mortality of marine

mammals, a section 101(a)(5)(D) authorization is appropriate. That

issue is addressed below.

The U.S. Congress did not intend to limit incidental harassment

authorizations to activities that would take place in a single year or

less, only that the authorization would be valid for no more than 1

year. After that period, the activity participants could reapply. This

interpretation of the statute is supported by the statement ``The

Committee notes that, in some instances, a request will be made for an

authorization identical to one issued in the previous year. In such

circumstances, the Committee expects the Secretary to act expeditiously

in complying with the notice and comment requirements.'' (H. Rept. 103-

439, 103rd Congress, 2nd Sess., p. 29.)

Comment 2: CLP believes that without more protective mitigation,

injury or mortality of harbor seals could occur, and, therefore, the

use of an IHA may be inappropriate because no serious injury or death

would be authorized.

Response: NMFS disagrees that the issuance of an IHA under section

101(a)(5)(D) is inappropriate for this project. In the IHA, NMFS is

requiring Caltrans to expand several of its mitigation measures to

further decrease the potential for serious injury or mortality of

harbor seals during construction activities (see Comments on Mitigation

and Mitigation Measures). Moreover, the monitoring and reporting

programs have been greatly expanded (see Monitoring and Reporting

sections). NMFS expects the mitigation requirements of the IHA to

preclude harbor seals from serious injury or mortality and will result

in the least practicable impact to harbor seals from construction

activities. Comment 3: CLP recommends that NMFS require that Bridge

retrofit construction be halted if any ``harmful disturbance'' occurs

during the pupping or molting season.

Response: NMFS will not be requiring Caltrans to stop work if

certain threshold seal disturbances are observed because certain

construction operations cannot be stopped in progress without

jeopardizing the structural integrity of the Bridge and NMFS does not

expect incidental harassment of harbor seals from construction

activities to have more than a negligible impact on the harbor seal

population. Nevertheless, if any unauthorized marine mammal taking

(serious injury or mortality) occurs as a result of seismic retrofit

construction activities, Caltrans will be subject to the penalties of

the MMPA. NMFS will, however, reevaluate the appropriateness of the IHA

before Caltrans reapplies for a new IHA next year, based on required

reports (see Reporting section).

Comment 4: CLP concludes that harbor seals that inhabit San

Francisco Bay (SFB) are a ``population stock'' under the MMPA and

believes NMFS

[[Page 67047]]

should consider the impacts of the retrofit construction relative to

the SFB population stock.

Response: NMFS disagrees that the best available information

indicates that harbor seals that inhabit SFB are a ``population stock''

under the MMPA. Studies have shown that adult harbor seals in SFB have

a high degree of site fidelity as indicated by (1) high occurrence of

red pelaged seals in SFB; (2) organochlorine containment levels are

higher in harbor seals that haul-out in SFB; and (3) limited movement

of adult harbor seals tagged in SFB to nearby coastal areas.

Nevertheless, data are not available that demonstrate that harbor seal

pups born at haul-out sites in SFB return to breed and pup at the same

site where they were born. Thus, at this time, scientists do not know

whether pups born in SFB show the same degree of site fidelity as

adults or whether they utilize other haul-outs either within SFB or in

nearby coastal areas when they mature. Studies of adult harbor seals

tagged in SFB indicate that the level of movement to nearby coastal

areas (20 percent) (Kopec and Harvey 1995, Harvey and Torok 1994) would

be sufficient to preclude isolation if those seals were breeding with

seals found along the coast (Harvey, J., Moss Landing Marine

Laboratory, pers. commun., November 1997). Moreover, genetic studies

have not been conducted to determine whether seals in SFB have unique

genetic variation or genotypes. In contrast, NMFS has separated harbor

seals within inland waters of Washington as a population stock under

the MMPA based on (1) extremely low mixing with coastal harbor seals,

(2) pollutant loads, (3) fishery interactions, (4) existence of unique

haplotypes in inland Washington harbor seals, and (5) differences in

mean pupping dates. The best available information does not demonstrate

that harbor seals in SFB are a unique biological population (Harvey,

J., pers. commun., 1997; Allen, S., NPS, pers. commun., November 1997;

Hanan, D., CDFG, pers. commun., November 1997). For these reasons, NMFS

does not consider harbor seals in SFB to be a population stock under

the MMPA.

Under section 117 of the MMPA, NMFS is required to prepare stock

assessment reports (SARs) for every marine mammal stock that occurs in

U.S. waters. NMFS has convened two expert working groups (NMFS and Non-

NMFS scientists/managers) to draft guidelines for preparing SARs

(Barlow et al. 1995, Wade and Angliss 1997). Furthermore, SARs are

available for public review and comment and are reviewed by regional

scientific review groups (all non-NMFS scientists). Using these

guidelines and in consultation with the Pacific Scientific Review

Group, NMFS published a SAR that considers harbor seals that occur in

California as a separate population stock (Barlow et al. 1995). This

SAR reports a population abundance estimate of 34,554 harbor seals.

This stock of harbor seals is not considered ``depleted'' or

``strategic'' under the MMPA or listed as an endangered or threatened

species under the Endangered Species Act. For these reasons, NMFS is

considering the impact of seismic retrofit construction of the Bridge

on the California harbor seal stock.

Harbor Seal Concerns

Comment 5: CLP believes the Federal Register notice's statement

``evidence to date has not indicated that anthropogenic disturbances

have resulted in increased mortality to harbor seals'' in 62 FR 46480

(September 3, 1997), is incorrect as several studies document this. The

Boles and Stewart (1980) study merely describes behavior patterns

consistent with one found with Bay harbor seals and does not support a

finding that human disturbance does not result in serious harm or

mortality.

Response: In retrospect, NMFS believes the statement made was too

broad and it should reflect that, to date, studies have not indicated

that airborne anthropogenic noise has resulted in increased harbor seal

mortality. NMFS would be interested in specific harbor seal studies

that indicate otherwise. It should be recognized that most of this

information is from studies on the impact of noise from rocket launches

and sonic booms on harbor seals and sea lions in the California Channel

Islands and, in the past, has been mostly qualitative. Upcoming studies

have been redesigned to be more quantitative.

Comment 6: CLP states that there is no evidence that seals will

adapt to construction, and harbor seals have abandoned sites in SFB.

Harbor seals hauling-out in areas of frequent but non-threatening

disturbances show a relatively higher tolerance for such events when

compared with more isolated areas where disturbance is rare.

Observations of harbor seals at Castro Rocks found that seals flush

easily in response to human disturbance.

Response: NMFS agrees that there is no scientific evidence that

demonstrates harbor seals will acclimate to disturbance from

construction activities. NMFS also believes that seals are likely to

acclimate to activities they perceive as non-threatening. Although

harbor seal colonies have abandoned haul-out sites in SFB, colonies

also have acclimated to various levels of human activity. In

particular, despite the regular exposure to traffic noises from the

Bridge, vessel traffic from commercial activities at the Chevron Long

Wharf, and vessel traffic from recreational boating and commercial

shipping in the area, harbor seals continue to haul-out, pup, breed,

and molt at Castro Rocks. For these reasons, NMFS believes that harbor

seals at Castro Rocks may acclimate to certain seismic retrofit

construction activities if they perceive these activities as non-

threatening.

Comment 7: CLP believes that seal counts by Caltrans personnel

during June 1994/1996 misrepresent the number of pups using Castro

Rocks.

Response: Presentation of the seal counts by Caltrans personnel

during June 1994 and 1996 was not intended to establish the period in

which pups are born at Castro Rocks. The best available information

indicates that in SFB harbor seal pups are first observed in mid-March,

peak numbers of pups are observed in early May, and by the first week

of June, the majority of the pups are weaned (Kopec, D., Romberg

Tiburon Centers, pers. commun., November 1997; (i.e., Kopec 1997)).

Comment 8: The statement in the Federal Register notice (62 FR

46480, September 3, 1997) that ``haul-out groups are temporary,

unstable aggregations'' does not accurately represent the current

knowledge of harbor seal population dynamics. Seals in SFB show strong

site fidelity.

Response: The statement is from Sullivan (1982) and is not refuted

by Kopec and Harvey (1995). However, because harbor seals show strong

site fidelity (Kopec and Harvey 1995, Stewart and Yochem 1994), the

statement may be misleading.

Comment 9: The finding of Bowles and Stewart (1980) referenced in

the Federal Register notice (62 FR 46480) that ``harbor seals tendency

to flee...decreased during the pupping season,'' does not support the

claim that young seals are protected from `` ...the startle response of

the herd.''

Response: Reviewing the referenced source, NMFS has determined that

there is no evidence that harbor seals are less sensitive to

disturbance during the pupping season than at other times. This agrees

with Kopec's observations (Kopec 1997). See Mitigation Measures.

Comments on Mitigation Measures

Comment 10: CLP had several concerns regarding NMFS' conclusions on

the impact of disturbance on molting harbor seals and the

appropriateness of Caltrans' proposed work closure period

[[Page 67048]]

(February 1-June 30). For example, CLP believes there is no scientific

evidence to support the conclusion in the Federal Register notice (62

FR 46480, September 3, 1997) that harbor seals have evolved adaptive

mechanisms to deal with natural disturbance from predators and seabirds

during the molt. CLP states this is supported by the behavior of harbor

seals to haul out in very isolated locations precisely to avoid

disturbance, and it is not factual to suggest that seabirds cause seals

to flush into the water. Existing as they do at the top of the food

web, CLP states, harbor seals using Castro Rocks have no natural

predators. CLP states that the very sensitive molting season of seals

using Castro Rocks extends to at least early or mid-August. Caltrans'

application and the EA failed to adequately assess the project's

impacts to molting seals during July and August. For these reasons, CLP

recommended that the Closure Period be extended to include the entire

molt.

Response: The process of molting is an important and energetically

demanding part of a seal's annual cycle (Leatherwood et al. 1992).

While on land, harbor seals bask in the sun to warm their body surface

and promote flow of blood to the skin which is essential for new hair

growth. While little is known about the effect of disturbance on

molting harbor seals, energetic costs are probably higher for seals

that spend more time in the water during the molt since a seal's

metabolic rate increases in the water (DeLong, R., NMFS, pers. commun.,

November 1997). Nevertheless, NMFS believes that it is likely that

harbor seals have evolved adaptive mechanisms to deal with exposure to

the water during the molt for the following reasons. First, on some

harbor seal haul-outs during the molting season seals must enter the

water once or even twice a day due to tidal fluctuations limiting

access to the haul-out. Second, since harbor seals lose hair in patches

during the molt, they are never completely hairless and would not be as

vulnerable to heat loss in the water during this period compared to

other seals (e.g., elephant seals) that lose their all their hair at

one time. Finally, due to the large amount of time hauled-out harbor

seals allocate to scanning their environment, it is likely that

terrestrial predation was an important selection pressure during the

early evolution of harbor seal behavior (Da Silva and Terhune 1988) and

could be the reason why hauled-out harbor seals appear to be so

sensitive to disturbance. Disturbance would not have been isolated to

only non-molting seasons and thus, harbor seals most likely evolved

mechanisms to tolerate exposure to water during the molt. Some harbor

seal colonies in California continue to be subject to disturbance from

wildlife such as seabirds (Hanan, D. pers. commun., 1997) and human

activities. If the levels of harbor seal disturbance during the molt

are relatively high, seals are likely to utilize other local haul-out

sites during the molt (DeLong, R., pers. commun. 1997; Hanan, D., pers.

commun. 1997; Harvey, J., pers. commun. 1997). Hanan (1996) found that

although harbor seals tagged at an isolated southern California haul-

out tended to exhibit site-fidelity during the molt, some seals were

observed molting at other nearby haul-outs.

The primary objectives of the Kopec and Harvey (1995) study was to

determine the population dynamic and movements, investigate the

concentration of pollutants, and assess the health of harbor seals

within and near SFB. Although the number of molting seals was recorded

during most field observations, molt observations were incidental to

Kopec and Harvey's (1995) primary census counts (Kopec 1997). Thus,

although Kopec and Harvey (1995) refer to the ``reproductive/molting''

period at Castro Rocks as occurring between March-July, no data are

presented to support this conclusion. Moreover, they report that ``In

San Francisco Bay, pupping occurs from March to May, and molt in June.

This corresponds with the greatest number of harbor seals counted in *

* *Castro Rocks.'' For these reasons, NMFS concluded that the proposed

Closure Period (February 1-June 30) would encompass all of the pupping

and breeding season, and nearly the entire harbor seal molting season

at Castro Rocks.

Recently available unpublished information indicates that the peak

number of actively molting harbor seals occurs in early July at Castro

Rocks (Kopec 1997), which coincides with the peak of the molt for

harbor seals near and within SFB (S. Allen, pers. commun., 1997). By

early August, only five to seven percent of the seals are actively

molting at Castro Rocks (Kopec 1997).

Based on new information on harbor seals molting at Castro Rocks,

NMFS has expanded the Closure Period to include the entire month of

July (see Mitigation Measures). The modified Closure Period (February

15 - July 31) is designed to encompass the entire harbor seal pupping

and breeding seasons and nearly the entire molting season at Castro

Rocks (see Mitigation Measures). This represents a period of five and

one-half months in which no work may be conducted on the substructure,

towers, or superstructure between Piers 52 and 57, inclusive (please

see related comment 11 below). Any harbor seals that are still molting

when work begins after the Closure Period are likely to utilize other

SFB haul-out sites if they are substantially disturbed by construction

activities in the area (DeLong, R., pers. commun., 1997; Hanan, D.,

pers. commun. 1997; Harvey, J., pers. commun. 1997). Expanding the

Closure Period further would result in another season of work near

Castro Rocks and in prolonged disturbance to seals utilizing Castro

Rocks. The Closure Period could be expanded during the second year of

the project if monitoring results indicate that impacts may be greater

than negligible.

Comment 11: CLP believes that the proposed seasonal restrictions

are not sufficient to protect seals during the earlier pupping and

nursing season because work will be allowed to continue on the

superstructure and could negatively impact seals during the spring

pupping and summer molting seasons. Furthermore, CLP notes that the IHA

notice contradicts the EA's superstructure seasonal closure period. For

these reasons, CLP recommends that the work closure area include a

prohibition on superstructure work between Piers 52 and 57.

Response: NMFS agrees and, as mentioned in comment 10 above, has

modified the Closure Period to include all retrofit construction

activities on the substructure (e.g., piers), towers, and

superstructure between Pier's 52 and 57, inclusive (see Mitigation

Measures). Since the Closure Period has been expanded to include nearly

the entire molting season (see above), NMFS has modified the Closure

Period to begin on February 15, instead of February 1. In SFB, harbor

seal pups are first observed in mid-March, peak numbers of pups are

observed in early May, and, by the first week of June, all pups are

weaned (Kopec and Harvey 1995). Thus, the Closure Period will include

the entire pupping season at Castro Rocks and a substantial pre-pupping

period when females are moving into pupping areas. As mentioned

previously, imposing a 6-month Work Closure Period (i.e., February 1-

July 31) would likely result in another season of work near Castro

Rocks and in prolonged disturbance to seals at Castro Rocks.

Comment 12: The CLP believes that the size of Caltrans' proposed

exclusion zone around Castro Rocks is arbitrary and inconsistent with

both the existing scientific literature or reported reactions and

actual observations of disturbance behavior at Castro Rocks. For these

[[Page 67049]]

reasons, CLP recommends that the exclusion zone be expanded to a

minimum of 200 m (656 ft) on all sides of Castro Rocks and that the

zone be expanded if monitoring indicates seals are adversely effected

by boats traveling outside the zone boundaries.

Response: The purpose of the exclusion zone is to establish an area

around Castro Rocks in which retrofit construction activity will be

prohibited during the pupping, breeding, and the majority of the

molting season (the Work Closure Period) to minimize the impacts to

seals during the sensitive periods of their life cycle. Caltrans

originally proposed that the exclusion zone be located between the

Bridge center line, between Piers 52 and 57, and extend to 200 ft (61

m) south of the most southwestern portion of Castro Rocks.

Reactions of harbor seals to disturbance depends upon the distance

of the activity to the seal, type of the activity (e.g., boat traffic,

aircraft overflights, loud sounds, etc.), phase of seal life cycle

(e.g., pupping season, non-pupping season), and the history of

disturbance the colony has previously experienced. Depending on the

activity, a wide range of seal ``reaction distances'' have been

reported in the literature (e.g., 30-1,800 m (98-5900 ft)). In an

adjacent SFB estuary, Bolinas Lagoon, 81 percent of disturbances

(boats, hikers, dogs) were within 100 and 200 m (328 and 656 ft) of a

harbor seal haul-out (Swift and Morgan 1993). Although seals at Castro

Rocks have habituated to background traffic noise from the Bridge, they

respond to unusual noises, such as hammering, truck horns, back-up

signal beeps, work boats, and other human activity on the Bridge

(Kopec, D., letter to CLP, dated October 3, 1997).

NMFS agrees that the exclusion zone should be expanded to further

minimize the impact of seismic retrofit construction activities during

the Closure Period. For this reason, NMFS is requiring Caltrans to

greatly expand the northern boundary of the exclusion zone. For

example, the northern boundary has been extended from the Bridge center

line to 250 ft (76.2 m) north of the most northern tip of Castro Rocks

(approximately 200 ft (61 m)) north of the Bridge center line). An

expansion of this boundary further north is impractical due to the need

for a safe navigation corridor north of the Bridge for work vessel

access to construction staging areas near the east end of the Bridge.

The southern boundary of the exclusion zone will be 250 ft (76.2 m)

south of the southern tip of Castro Rocks. Due to the location of this

boundary relative to the Bridge (600 ft/183 m), it is unlikely that the

unrestricted area further south would be practicable for use during

construction (e.g., corridor to a staging area on the south side of the

Bridge). Any further expansion of the southern boundary would encroach

onto waters outside Caltran's control (e.g., right-of-way) and could

affect Chevron's oil pier operations further south. The eastern

boundary will be 300 ft (91.4 m) east of the eastern tip of Castro

Rocks, and the western boundary will be 300 ft (91.4 m) west of the

western tip of Castro Rocks. Similarly, any further expansion of these

boundaries would encroach onto waters outside Caltrans' control.

Caltrans will minimize vessel traffic in the exclusion zone when

conducting construction activities during the Work Period. For these

reasons, NMFS believes these boundaries will have the least practicable

impact on the California harbor seal population.

Comment 13: Caltrans recommends that the prohibition on pile

installation and the limitation on maximum noise levels to 86 DBA re 20

uPa at 50 m between 7 p.m. and 7 a.m. be modified to the hours between

9 p.m. and 7 a.m.. Caltrans states that this is necessary to allow for

the Bridge retrofit contractor to use two working shifts instead of one

shift. Caltrans also recommends removing the 24-hr construction noise

limitation near Castro Rocks during the pupping/molting restriction

period because no work will be conducted between Piers 52 and 57,

inclusive on the substructure, towers, or superstructure during this

period.

Response: NMFS agrees. Although the night time restriction for pile

installation and maximum noise levels was originally developed by

Caltrans to minimize human residential noise disturbance, NMFS is also

requiring night time restrictions because it believes that it could

protect seals at Castro Rocks if they change their hauling-out patterns

from daytime to night time. NMFS has modified the time period for this

requirement from 7 p.m.-7 a.m. to 9 p.m.-7 a.m. because restricting

this mitigation measure further would allow only one work shift, would

likely result in another season of work near Castro Rocks, and thus,

would result in prolonged disturbance to seals utilizing Castro Rocks

(see Mitigation Measures). NMFS also agrees that the 24-hr. noise

limitation near Castro Rocks is no longer necessary due to all work

ceasing on the substructure, towers, and superstructure on Pier's 52-

57, inclusive, during the pupping, breeding, and majority of the

molting season.

Comment 14: CLP recommends that NMFS require Caltrans to conduct

certain offsite mitigation that will enhance the protection of

alternative haul-out sites, many of which are under pressure from human

disturbance. Such mitigation might take the form of education signs or

posters at haul-outs and other locations to reduce potential for human

disturbance.

Response: NMFS believes that the mitigation measures imposed under

the IHA will effectively mitigate the activity to the lowest level

practicable and still allow the project to continue near to schedule.

As a result, additional off-site mitigation measures are unwarranted.

NMFS believes that mitigation banking is appropriate only under those

circumstances when the impact cannot be mitigated onsite.

Monitoring and Reporting Concerns

Comment 15: CLP believes that the proposed monitoring plan is

inadequate and should be replaced by a comprehensive, quantitative

monitoring program. CLP recommends that the IHA establish upper limits

of disturbance beyond which the source construction activity is

curtailed. CLP believes the IHA should require continuous site

monitoring and immediate reporting that, when triggered, will

temporarily halt construction activity near Castro Rocks and will

impose additional mitigation.

Response: NMFS has significantly expanded the requirements of the

monitoring program that must be implemented by Caltrans under its IHA

(see Monitoring). For example, the monitoring program includes pre-

construction monitoring of Castro Rocks (e.g., baseline information)

and frequent monitoring each week within the Work Period to document

the effects of construction activities on harbor seals at Castro Rocks.

The monitoring of at least one alternative haul-out site in SFB is also

required to evaluate whether harbor seals at Castro Rocks could be

hauling out at other sites in SFB as a result of construction.

Monitoring will also occur during the Closure Period to evaluate

whether construction activities are disturbing the seals during their

pupping, breeding and molting periods. Moreover, night time censussing

of harbor seals will occur during the Closure Period and Work Period at

Castro Rocks to evaluate whether harbor seal haul-out behavior may be

affected by construction activities during these periods. NMFS believes

this improved monitoring program will be sufficient to collect

appropriate data to adequately evaluate the biological impact of

[[Page 67050]]

construction activities on Castro Rocks harbor seals.

Comment 16: CLP suggested that enhanced protection and monitoring

of other, limited, haul-out sites in SFB are critical to monitoring

measures and must be implemented under National Environmental Policy

Act (NEPA) and MMPA.

Response: In the IHA, NMFS is requiring Caltrans to simultaneously

monitor at least one other harbor seal haul-out site in SFB to document

potential changes in harbor seal population dynamics in SFB from

seismic retrofit construction disturbance of seals at Castro Rocks.

NEPA Concerns

Comment 17: CLP states that NMFS must comply with NEPA, which is

the statute requires the preparation of an environmental impact

statement (EIS) where a Federal project may have a significant adverse

impact on the environment.

Response: NMFS is issuing the IHA in compliance with NEPA. After

assessing the effects of the Bridge project (undertaken with the

mitigation measures) on marine mammals in an EA, NMFS found that

issuance of the IHA will not have a significant effect on the human

environment. Accordingly, an EIS was not prepared.

For the Bridge project as a whole, the lead Federal agency is the

Federal Highway Administration (FHA). On August 15, 1997, the FHA

determined that the retrofit project is categorically excluded from

NEPA. In that determination, the FHA stated that the retrofit project

does not have a significant effect on the human environment.

In addition, Caltrans determined that the retrofit project is

statutorily exempt from the California Environmental Quality Act (CEQA)

under section 180.2 of the Streets and Highways Code and section

2180(b)(4) of the Public Resources Code.

Comment 18: CLP states that CLP believes that an EIS must be

prepared, unless the project is ``fully mitigated,'' to avoid

``devastating impacts'' (e.g., abandonment) on the future viability of

Castro Rocks as a harbor seal haul-out site and adversely affecting the

population stock that relies on Castro Rocks.

Response: NMFS does not agree that abandonment of Castro Rocks as a

haul-out site is likely from the seismic retrofit construction of the

Bridge, provided Caltrans undertakes the mitigation measures required

in the IHA. NMFS expects that the short-term impact of construction to

have a temporary mod-ification in behavior by harbor seals at Castro

Rocks and possibly by some California sea lions. At worst, disturbance

from construction activities is expected to cause the harbor seals to

haul-out at night at Castro Rocks (Kopec, D., letter to CLP, dated

October 3, 1997), or to utilize alternative haul-out sites in the SFB

for a short period (Harvey, J., 1997, pers. commun.). Therefore, NMFS

expects the impacts from the seismic retrofit construction of the

Bridge to have no more than a negligible impact on the California

harbor seal population and does not expect harbor seals to permanently

abandon Castro Rocks as a rookery or haul-out. With the mitigation

measures NMFS is requiring, the Bridge project is expected to result in

minimal disturbance to harbor seals at Castro Rocks.

Mitigation Measures

To limit incidental harassment to the lowest practicable level,

NMFS will require Caltrans to implement the following mitigation

measures. First, Caltrans must cease seismic retrofit construction work

from February 15 to July 31 on the Bridge substructure, towers, and

superstructure between Pier's 52 and 57, inclusive (Closure Period).

Seismic retrofit work may occur from August 1 to February 14 on the

Bridge substructure, towers, and superstructure between Pier's 52 and

57, inclusive (Work Period). Second, no water craft associated with

construction activities will be deployed during the year within the

``exclusion zone'' except when construction equipment is required for

seismic retrofit construction between Piers 52 and 57, inclusive, and

within the Work Period. Vessel traffic will be minimized in the

exclusion zone when construction activities are occurring during the

Work Period. The boundary of the exclusion zone is rectangular in shape

(1700 ft by 800 ft (518.2 m by 244 m)) and completely encloses Castro

Rocks and Pier's 52-57, inclusive. The northern boundary of exclusion

zone will be located 250 ft (76.2 m) from the most northern tip of

Castro Rocks, and the southern boundary will be located 250 ft (76.2 m)

from the most southern tip of Castro Rocks. The eastern boundary will

be located 300 ft (91.4 m) from the most eastern tip of Castro Rocks,

and the western boundary will be located 300 ft (91.4 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. Lastly, between 9 p.m. and 7 a.m., no piles

may be installed on the Bridge, and construction noise may not exceed

86 DBA re 20 uPa at 50 ft (15 m).

Summary of 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 will monitor at least one additional harbor seal haul-out

within SFB 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 - February 14) and the Closure Period Phase (February 15 -

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 Pier's 52 and 57, inclusive, the

monitor(s) will conduct baseline observations of seal behavior once a

day for a period of five 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 haul-out at least 3 days/week

(Work Period) and 2 days/week (Closure Period), during a low tide.

In addition, NMFS proposes to require under a second authorization

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.

[[Page 67051]]

Reporting

Caltrans will 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 level measurements made at the haulout will also be

provided.

A draft interim report must be submitted to the Southwest Regional

Administrator on August 1, 1998. A draft final report must be submitted

to the Southwest Regional Administrator within 90 days after the

expiration of Caltrans Incidental Harassment Authorization. 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.

NEPA

NMFS has prepared an EA that concludes that the impacts of

Caltrans' seismic retrofit construction of the Bridge will not have a

significant impact on the human environment. A copy of the EA is

available upon request (see ADDRESSES).

Conclusions

NMFS has determined that the short-term impact of the seismic

retrofit construction of the Bridge, as described above, will 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 haul-out, 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 above.

Since NMFS is assured that the taking will not result in more than

the incidental harassment (as defined by the MMPA) of small numbers of

Pacific harbor seals and possibly of California sea lions; would not

have an unmitigatable adverse impact on the availability of these

stocks for subsistence uses; and would result in the least practicable

impact on the stocks, NMFS has determined that the requirements of

section 101(a)(5)(D) have been met and the authorization can be issued.

For the above reasons, NMFS has issued an IHA for a 1-year period

beginning on the date noted above (see EFFECTIVE DATES) for the

incidental harassment of harbor seals and California sea lions by the

seismic retrofit of the Richmond-San Rafael Bridge, San Francisco Bay,

California, provided the above mentioned monitoring and reporting

requirements are incorporated.

Dated: December 16, 1997.

Hilda Diaz-Soltero,

Director, Office of Protected Resources, National Marine Fisheries

Service.

[FR Doc. 97-33387 Filed 12-22-97; 8:45 am]

BILLING CODE 3510-22-F