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Taking of Marine Mammals Incidental to Specified Activities; Construction of the East Span of the San Francisco-Oakland Bay Bridge
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
[Federal Register: May 8, 2006 (Volume 71, Number 88)]
[Notices]
[Page 26750-26754]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08my06-33]
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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