[Federal Register Volume 71, Number 88 (Monday, May 8, 2006)]
[Notices]
[Pages 26750-26754]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-6929]



[[Page 26750]]

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 041706A]


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

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

ACTION: Notice of issuance of an incidental harassment authorization.

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

DATES: This authorization is effective from April 30, 2006, until April 
29, 2007.

ADDRESSES: A copy of the application, IHA, and/or a list of references 
used in this document may be obtained by writing to Steve Leathery, 
Chief, Permits, Conservation and Education Division, Office of 
Protected Resources, National Marine Fisheries Service, 1315 East-West 
Highway, Silver Spring, MD 20910-3225.

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

SUPPLEMENTARY INFORMATION:

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce to allow, upon request, the 
incidental, but not intentional, taking by Level B harassment of small 
numbers of marine mammals of a species or population stock 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.

    Section 101(a)(5)(D) of the MMPA established an expedited process 
by which citizens of the United States can apply for an authorization 
to incidentally take small numbers of marine mammals by harassment. 
Except with respect to certain activities not pertinent here, the MMPA 
defines ``harassment'' as:

    any act of pursuit, torment, or annoyance which (i) has the 
potential to injure a marine mammal or marine mammal stock in the 
wild [Level A harassment]; or (ii) has the potential to disturb a 
marine mammal or marine mammal stock in the wild by causing 
disruption of behavioral patterns, including, but not limited to, 
migration, breathing, nursing, breeding, feeding, or sheltering 
[Level B harassment].

    Section 101(a)(5)(D) establishes a 45-day time limit for NMFS 
review of an application followed by a 30-day public notice and comment 
period on any proposed authorizations for the incidental harassment of 
small numbers of marine mammals. Within 45 days of the close of the 
comment period, NMFS must either issue or deny issuance of the 
authorization.

Summary of Request

    On October 17, 2005, CALTRANS sumbitted a request to NOAA 
requesting renewal of an IHA for the possible harassment of small 
numbers of California sea lions (Zalophus californianus), Pacific 
harbor seals (Phoca vitulina richardsi), harbor porpoises (Phocoena 
phocoena), and gray whales (Eschrichtius robustus) incidental to the 
construction of a replacement bridge for the East Span of the SF-OBB, 
in San Francisco Bay (SFB or the Bay), California. An IHA was issued to 
CALTRANS for this activity on January 3, 2005 and expired on January 3, 
2006 (70 FR 2123, January 12, 2005). Background information on the 
issuance of this IHA was published in the Federal Register on January 
26, 2006 (71 FR 4352). A detailed description of the SF-OBB project was 
provided in the Federal Register on November 14, 2003 (68 FR 64595), 
and is not repeated here.

Comments and Responses

    A notice of receipt and request for 30-day public comment on the 
application and proposed authorization was published on January 26, 
2006 (71 FR 4352). During the 30-day public comment period, comments 
were received from the Marine Mammal Commission (the Commission).
    Comment 1: The Commission believes NMFS' preliminary determinations 
are reasonable, provided that the visual monitoring of the safety zone 
to be conducted prior to and during pile driving operations is adequate 
to detect all marine mammals within the safety zone. According to 
CALTRANS, pile driving would occur from 7 a.m. to 7 p.m., visual 
monitoring in the late afternoon and early evening would be compromised 
during the winter months.
    Response: The Marine Mammal Monitoring Plan developed by CALTRANS 
in May 2002 notes that marine mammal observers will have night-time 
infrared (IR) scopes or other tools to conduct monitoring during low 
light conditions. CALTRANS has indicated that when using the IR scopes 
the marine mammal safety zone and marine mammals are visible. Please 
also refer to Federal Register notice published on November 14, 2003 
(68 FR 64595) for additional information. NMFS will require the use of 
IR scopes in the IHA.
    Comment 2: The Commission continues to believe that, in situations 
where a temporary threshold shift (TTS) may lead to biologically 
significant behavioral effects (e.g., an increased risk of natural 
predation or ship strikes), it should be considered as having the 
potential for injury (i.e., Level A Harassment).
    Response: CALTRANS will implement a series of mitigation measures 
including visual monitoring prior to and during construction, 
installation of a bubble curtain for in-water pile driving, 
establishment of safety/buffer zones, and implementing ``soft star'' 
hammer strikes. Based on CALTRANS' June 2004 and January 2005 annual 
monitoring reports, the East Span Project is resulting in only small 
numbers of pinnipeds being harassed (through October 2005, the 
biological observers indicated that only one startle behavior of a sea 
lion was observed as a result of construction). Therefore, NMFS 
believes that it is not likely that a TTS would occur. In addition, 
NMFS has addressed the issue

[[Page 26751]]

of impact assessment in several previous small take authorizations, and 
without new scientific documentation on this issue, a detailed response 
is not warranted here. For reviewers interested in this discussion, 
refer to the incidental take authorizations for the USS WINSTON S. 
CHURCHILL shock trial (66 FR 22450, May 4, 2001) and Eglin Air Force 
Base's Precision Strike Weapon (70 FR 48675, August 19, 2005).
    Comment 3: An across-the-board redefinition of TTS from Level A 
harassment to Level B harassment raises questions both in terms of the 
activities that involve the potential for repeated TTS harassment and 
of general cumulative effects. The Commission recommends that NMFS 
revise its assessment of TTS accordingly.
    Response: As NMFS has stated in a previous Federal Register notice 
(68 FR 64595, November 14, 2003) that the reclassification of TTS is 
irrelevant for this IHA, since mitigation and monitoring requirements 
under the IHA should prevent TTS. While there have been debates among 
scientists regarding whether a permanent shift in hearing threshold 
(PTS) can occur with repeated exposures of TTS, at least one study 
showed that long-term (4 - 7 years) noise exposure on three 
experimental pinniped species had caused no change on their underwater 
hearing thresholds at frequencies of 0.2 - 6.4 kHz (Southall et al., 
2005).


Description of the Marine Mammals Potentially Affected by the Activity

    General information on the marine mammal species found in 
California waters can be found in Caretta et al. (2004), which is 
available at the following URL: http://www.nmfs.noaa.gov/pr/PR2/Stock_Assessment_Program/sars.html. Refer to that document for information 
on these species.
    The marine mammals most likely to be found in the SF-OBB area are 
the California sea lion, Pacific harbor seal, and harbor porpoise. From 
December through May gray whales may also be present in the SF-OBB 
area. Information on these 4 species was provided in the November 14, 
2003 (68 FR 64595) and January 26, 2006 (71 FR 4352) Federal Register 
notices and is not repeated here.

Potential Effects on Marine Mammals and Their Habitat

    CALTRANS and NMFS have determined that open-water pile driving, as 
outlined in the project description, has the potential to result in a 
Level B harassment (e.g., disruption of behavioral patterns) of 
California sea lions, Pacific harbor seals, harbor porpoises, and gray 
whales that may be swimming, foraging, or resting in the project 
vicinity while pile driving is being conducted. Pile driving could 
potentially harass those few pinnipeds that are in the water close to 
the project site, whether their heads are above or below the surface.
    Based on airborne noise levels measured and on-site monitoring 
conducted during 2004 under the previous IHA, noise levels from the 
East Span project did not result in the harassment of harbor seals 
hauled out on Yerba Buena Island (YBI). Also, noise levels from the 
East Span project are not expected to result in harassment of the sea 
lions hauled out at Pier 39 as airborne and waterborne sound pressure 
levels (SPLs) would attenuate to below harassment levels by the time 
they reach that haul-out site, 5.7 kilometers (3.5 miles) from the 
project site.
    For reasons provided in greater detail in NMFS' November 14, 2003 
(68 FR 64595) Federal Register notice and in CALTRANS' June 2004 and 
January 2005 annual monitoring reports, the East Span Project is 
resulting in only small numbers of pinnipeds being taken by Level B 
harassment (through October 2005, the biological observers indicated 
that only one startle behavior of a sea lion was observed as a result 
of East Span construction) and, therefore, is not expected to result in 
more than a negligible impact on marine mammal species or stocks and 
will not have a significant impact on their habitat. Short-term impacts 
to habitat may include minimal disturbance of the sediment where the 
channels are dredged for barge access and where individual bridge piers 
are constructed. Long-term impacts to marine mammal habitat will be 
limited to the footprint of the piles and the obstruction they will 
create following installation. However, this impact is not considered 
significant as the marine mammals can easily swim around the piles of 
the new bridge, as they currently swim around the existing bridge 
piers.

Mitigation

    The following mitigation measures are required under the IHA to 
reduce impacts to marine mammals to the lowest extent practicable.

Barrier Systems

    An air bubble curtain system is required to be used only when 
driving the permanent open-water piles at Piers E3 - E6 of Skyway and 
Piers E1 and E2 of the Self-Anchored Suspension (SAS) span. While the 
bubble curtain is required specifically as a method to reduce impacts 
to endangered and threatened fish species in SFB, it may also provide 
some benefit to marine mammals. The NMFS' Biological Opinion and the 
California Department of Fish and Game's (CDFG) 2001 Incidental Take 
Permit also allow for the use of other equally effective methods, such 
as cofferdams, as an alternative to the air bubble curtain system to 
attenuate the effects of sound pressure waves on fish during driving of 
permanent in-Bay piles (NMFS 2001; CDFG, 2001). Piers E-16 through E-7 
for both the eastbound and westbound structures of the Skyway will be 
surrounded by sheet-pile cofferdams, which will be de-watered before 
the start of pile driving. De-watered cofferdams are generally 
effective sound attenuation devices. For Piers E3 through E6 of the 
Skyway and Piers 1 and E2 of the Self-Anchored Suspension span, it is 
anticipated that cofferdams will not be used; therefore, a bubble 
curtain will surround the piles.

Sound Attenuation

    As a result of the determinations made during the Pile Installation 
Demonstration Project (PIDP) restrike and the investigation at the 
Benicia-Martinez Bridge, NMFS determined in 2003 that CALTRANS must 
install an air bubble curtain for pile driving for the open-water piles 
without cofferdams located at the SF-OBB. This air bubble curtain 
system consists of concentric layers of perforated aeration pipes 
stacked vertically and spaced no more than five vertical meters apart 
in all tide conditions. The minimum number of layers must be in 
accordance with water depth at the subject pile: 0-<5 m = 2 layers 
(1263 cfm); 5-<10 m = 4 layers (2526 cfm), 10-<15 m = 7 layers (4420 
cfm); 15-<20 m = 10 layers (6314 cfm); 20-<25 m= 13 layers (8208 cfm). 
The lowest layer of perforated aeration pipes must be designed to 
ensure contact at all times and tidal conditions with the mudline 
without sinking into the bay mud. Pipes in any layer must be arranged 
in a geometric pattern, which will allow for the pile driving operation 
to be completely enclosed by bubbles for the full depth of the water 
column.
    To provide a uniform bubble flux, each aeration pipe must have four 
adjacent rows of air holes along the pipe. Air holes must be 1.6-mm 
diameter and spaced approximately 20 mm apart. The bubble curtain 
system will provide a bubble flux of at least two cubic meters per 
minute, per linear meter of pipeline in each layer. Air holes must be 
placed in 4 adjacent rows.

[[Page 26752]]

    The air bubble curtain system must be composed of the following: 
(1) An air compressor(s), (2) supply lines to deliver the air, (3) 
distribution manifolds or headers, (4) perforated aeration pipes, and 
(5) a frame. The frame facilitates transport and placement of the 
system, keeps the aeration pipes stable, and provides ballast to 
counteract the buoyancy of the aeration pipes in operation. Meters are 
required to monitor the operation of the bubble curtain system. 
Pressure meters will be installed and monitored at all inlets to 
aeration pipelines and at points of lowest pressure in each branch of 
the aeration pipeline. If the pressure or flow rate in any meter falls 
below 90 percent of its operating value, the contractor will cease pile 
driving operations until the problem is corrected and the system is 
tested to the satisfaction of the CALTRANS resident engineer.

Establishment of Safety/Buffer Zones

    A safety zone is to be established and monitored to include all 
areas where the underwater SPLs are anticipated to equal or exceed 180 
dB re 1 microPa RMS (impulse) for harbor porpoises and gray whales, and 
190 dB re 1 microPa RMS (impulse) for pinnipeds, for open water pile 
driving activities. Prior to commencement of any pile driving, a 
preliminary 500-m (1,640-ft) radius safety zone for marine mammals will 
be established around the pile driving site, as it was for the PIDP. 
Once pile driving begins, either new safety zones can be established 
for the 500 kJ and 1700 kJ hammers or the 500 m (1,640 ft) safety zone 
can be retained. If new safety zones are established based on SPL 
measurements, NMFS requires that each new safety zone be based on the 
most conservative measurement (i.e., the largest safety zone 
configuration). SPLs will be recorded at the 500-m (1,640-ft) contour. 
The safety zone radius for marine mammals will then be enlarged or 
reduced, depending on the actual recorded SPLs.
    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 seen by 
the observer in that time it will be assumed that the animal has moved 
beyond the safety zone. This 15-minute criterion is based on scientific 
evidence that harbor seals in San Francisco Bay dive for a mean time of 
0.50 minutes to 3.33 minutes (Harvey and Torok, 1994), and the mean 
diving duration for harbor porpoises ranges from 44 to 103 seconds 
(Westgate et al., 1995). However, due to the limitations of monitoring 
from a boat, there can be no assurance that the zone will be devoid of 
all marine mammals at all times.
    Once the pile driving of a segment begins it cannot be stopped 
until that segment has reached its predetermined depth due to the 
nature of the sediments underlying the Bay. If pile driving stops and 
then resumes, it would potentially have to occur for a longer time and 
at increased energy levels. In sum, this would simply amplify impacts 
to marine mammals, as they would endure potentially higher SPLs for 
longer periods of time. Pile segment lengths and wall thickness have 
been specially designed so that when work is stopped between segments 
(but not during a single segment), the pile tip is never resting in 
highly resistant sediment layers. Therefore, because of this 
operational situation, if seals, sea lions, or harbor porpoises enter 
the safety zone after pile driving of a segment has begun, pile driving 
will continue and marine mammal observers will monitor and record 
marine mammal numbers and behavior. However, if pile driving of a 
segment ceases for 30 minutes or more and a marine mammal is sighted 
within the designated safety zone prior to commencement of pile 
driving, the observer(s) must notify the Resident Engineer (or other 
authorized individual) immediately and follow the mitigation 
requirements as outlined previously in this document.

Soft Start

    It should be recognized that although marine mammals will be 
protected from Level A harassment by establishment of an air-bubble 
curtain and marine mammal observers monitoring a 190-dB safety zone for 
pinipeds and 180-dB safety zone for cetaceans, mitigation may not be 
100 percent effective at all times in locating marine mammals. 
Therefore, in order to provide additional protection to marine mammals 
near the project area by allowing marine mammals to vacate the area 
prior to receiving a potential injury, CALTRANS will also ``soft 
start'' the hammer prior to operating at full capacity. CALTRANS 
typically implements a ``soft start'' with several initial hammer 
strikes at less than full capacity (i.e., approximately 40-60 percent 
energy levels) with no less than a 1 minute interval between each 
strike. Similar levels of noise reduction are expected underwater. 
Therefore, the contractor will initiate hammering of both the 500-kJ 
and the 1,700-kJ hammers with this procedure in order to allow 
pinnipeds or cetaceans in the area to voluntarily move from the area, 
this should expose fewer animals to loud sounds both underwater and 
above water noise. This would also ensure that, although not expected, 
any pinnipeds and cetaceans that are missed during safety zone 
monitoring will not be injured.

Compliance with Equipment Noise Standards

    To mitigate noise levels and, therefore, impacts to California sea 
lions, Pacific harbor seals, harbor porpoises, and gray whales, all 
construction equipment will comply 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.

Monitoring

    The following monitoring measures are required under the IHA to 
reduce impacts to marine mammals to the lowest extent practicable.

Visual Observations

    The area-wide baseline monitoring and the aerial photo survey to 
estimate the fraction of pinnipeds that might be missed by visual 
monitoring have been completed under the current IHA and do not need to 
be continued.
    Safety zone monitoring will be conducted during driving of all 
open-water, permanent piles without cofferdams and with cofferdams when 
underwater SPLs reach 180 dB RMS or greater. Monitoring of the pinniped 
and cetacean safety zones will be conducted by a minimum of three 
qualified NMFS-approved observers for each safety zone. One three-
observer team will be required for the safety zones around each pile 
driving site, so that multiple teams will be required if pile driving 
is occurring at multiple locations at the same time. The observers will 
begin monitoring at least 30 minutes prior to startup of the pile 
driving. Observers will conduct the monitoring from small boats, as 
observations from a higher vantage point (such as the SF-OBB) is not 
practical. Pile driving will not begin until the safety zone is clear 
of marine mammals. However, as described in the Mitigation section, 
once pile driving of a segment begins, operations will continue 
uninterrupted until the segment has reached its predetermined depth. 
However, if pile driving of a segment ceases for 30 minutes or more and 
a marine mammal is sighted within the designated safety zone prior to

[[Page 26753]]

commencement of pile driving, the observer(s) must notify the Resident 
Engineer (or other authorized individual) immediately and follow the 
mitigation requirements outlined previously (see Mitigation). 
Monitoring will continue through the pile driving period and will end 
approximately 30 minutes after pile driving has been completed. 
Biological observations will be made using binoculars during daylight 
hours. Infrared (IR) scopes will be used during low light condition for 
marine mammal monitoring.
    In addition to monitoring from boats, during open-water pile 
driving, monitoring at one control site (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) will be 
designated and monitored for comparison. Monitoring will be conducted 
twice a week at the control site whenever open-water pile driving is 
being conducted. Data on 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. The 
reactions of marine mammals will be recorded based on the following 
classifications that are consistent with the Richmond Bridge Harbor 
Seal survey methodology (for information on the Richmond Bridge 
authorization, see 68 FR 66076, November 25, 2003): (1) No response, 
(2) head alert (looks toward the source of disturbance), (3) approach 
water (but not leave), and (4) flush (leaves haul-out site). The number 
of marine mammals under each disturbance reaction will be recorded, as 
well as the time when seal re-haul after a flush.

Acoustical Observations

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

Reporting

    Under previous IHAs, CALTRANS submitted weekly marine mammal 
monitoring reports and in January, 2005, CALTRANS submitted its Marine 
Mammal and Acoustic Monitoring for the Eastbound Structure. This annual 
report is available by contacting NMFS (see ADDRESSES) or on the Web at 
http://biomitigation.org. A report for the 2005 season will be 
completed and posted here shortly.
    Under the 2006 IHA, coordination with NMFS will occur on a weekly 
basis, or more often as necessary. During periods with open-water pile 
driving activity, weekly monitoring reports will be made available to 
NMFS and the public at http://biomitigation.org. These weekly reports 
will include a summary of the previous week's monitoring activities and 
an estimate of the number of seals and sea lions that may have been 
taken by Level B harassment as a result of pile driving activities.
    In addition, CALTRANS will provide NMFS' Southwest Regional 
Administrator with a draft final report within 90 days after completion 
of the westbound Skyway contract and 90 days after completion of the 
Suspension Span foundations contract. This report should detail the 
monitoring protocol, summarize the data recorded during monitoring, and 
estimate the number of marine mammals that may have been harassed due 
to pile driving. If comments are received from the Regional 
Administrator on the draft final report, a final report must be 
submitted to NMFS within 30 days thereafter. If no comments are 
received from NMFS, the draft final report will be considered to be the 
final report.

National Environmental Policy Act (NEPA)

    In November, 2003, NMFS prepared an Environmental Assessment (EA) 
and, on November 4, 2003, made a Finding of No Significant Impact 
(FONSI). A review of the renewal of this IHA has determined that the 
findings and determinations made in the 2003 EA/FONSI continue to 
accurately address the impacts on the human environment through the 
taking of marine mammals by the CALTRANS project. Therefore, 
preparation of an environmental impact statement on this action is not 
required by section 102(2) of the NEPA or its implementing regulations. 
A copy of the EA and FONSI are available upon request (see ADDRESSES).

Endangered Species Act (ESA)

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

[[Page 26754]]

Determinations

    For the reasons discussed in this document and in previously 
identified supporting documents, NMFS has determined that the impact of 
pile driving and other activities associated with construction of the 
East Span Project may result in the Level B harassment of small numbers 
of California sea lions, Pacific harbor seals, harbor porpoises, and 
potentially gray whales that inhabit or visit SFB in general and the 
vicinity of the SF-OBB in particular. While behavioral modifications, 
including temporarily vacating the area around the construction site, 
may be made by these species to avoid the resultant visual and acoustic 
disturbance, the availability of alternate areas within SFB and haul-
out sites (including pupping sites) and feeding areas within the Bay 
has led NMFS to determine that this action will have a negligible 
impact on California sea lions, Pacific harbor seals, harbor porpoises, 
and gray whale populations along the California coast.
    In addition, no take by Level A harassment (injury) or death is 
anticipated or authorized and Level B harassment takes should be at the 
lowest level practicable due to incorporation of the mitigation 
measures mentioned previously in this document.

Authorization

    For the reasons previously discussed, NMFS has issued an IHA for a 
1-year period to take small numbers of harbor seals, California sea 
lions, harbor porpoises, and gray whales, by Level B harassment 
incidental to construction of a replacement bridge for the East Span of 
the San Franciso-Oakland Bay Bridge in California, provided the 
previously mentioned mitigation, monitoring, and reporting requirements 
are incorporated. NMFS has determined that the activity would result in 
the harassment of only small numbers of harbor seals, California sea 
lions, harbor porpoises, and possibly gray whales and will have no more 
than a negligible impact on these marine mammal stocks.

    Dated: April 27, 2006.
James H. Lecky,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. E6-6929 Filed 5-5-06; 8:45 am]
BILLING CODE 3510-22-S