Taking Marine Mammals Incidental to Specified Activities; Sandholdt Road Bridge Replacement, Moss Landing, California, 333-338 [05-97]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 70, Number 2 (Tuesday, January 4, 2005)]
[Notices]
[Pages 333-338]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-97]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 072204A]


Taking Marine Mammals Incidental to Specified Activities; 
Sandholdt Road Bridge Replacement, Moss Landing, California

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 Monterey County 
Department of Public Works (Monterey County DPW) to take small numbers 
of marine mammals, by harassment, incidental to the replacement of the 
Sandholdt Road Bridge (Bridge) in Moss Landing, Monterey County, CA.

DATES: This authorization is effective from April 15, 2005, through 
April 14, 2006.

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: Kenneth Hollingshead, Office of 
Protected Resources, NMFS, (301) 713-2389, ext 128 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 of small numbers 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 
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.''
    Subsection 101(a)(5)(D) of the MMPA established an expedited 
process by which citizens of the United States can apply for an 
authorization to incidentally take small numbers of marine mammals by 
harassment. Except for certain categories of actions 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].
    Subsection 101(a)(5)(D) establishes a 45-day time limit for NMFS 
review of an application followed by a 30-day public notice and comment 
period on any proposed authorizations for the incidental harassment of 
small numbers of marine mammals. Within 45 days of the close of the 
comment period, NMFS must either issue or deny issuance of the 
authorization.

[[Page 334]]

Summary of Request

    On February 26, 2004, NMFS received an IHA application from the 
California Department of Transportation (CALTRANS) on behalf of the 
Monterey County DPW. The IHA request is for the potential harassment of 
small numbers of Pacific harbor seals (Phoca vitulina) and possibly 
some California sea lions (Zalophus californianus), incidental to 
demolition of the current Bridge and construction of a new Bridge. 
Construction is scheduled to extend from early to mid-2005 until the 
fall of 2006. A detailed description of the work planned is contained 
in the CALTRANS application and in LSA Associates, Inc. (1999).
    The County of Monterey, with funding from the Federal Highway 
Administration (FHWA), proposes to replace the existing one-lane Bridge 
over the Moss Landing Slough. Sandholdt Road, a two-lane county road, 
carries an average of about 2700 vehicles per day between Moss Landing 
Road and part of the community of Moss Landing. The Bridge is of 
unknown age with a deck replacement having taken place over 54 years 
ago. The wooden piling system has been weakened by marine bore worms 
and is decaying. The Bridge, therefore, is at the end of its useful 
service life. The one-lane Bridge is a traffic safety concern and does 
not meet Federal standards for rural roads, which require such bridges 
to have a minimum of two traffic lanes and safe access for pedestrians. 
The Bridge does not meet structural capacity requirements as it is 
incapable of withstanding loads over minimum highway legal loads. 
Further, because of its age and dilapidated condition, the structure is 
not capable of withstanding a significant earthquake without the 
possibility of incurring significant damage that may require the Bridge 
to be closed for repairs. Bridge closure may result in significant 
economic impact to the community, as the Bridge is the only public 
access point to the island.


Description of the Activity

    The proposed new Bridge will improve traffic operations and safety 
and provide safe access for pedestrians and bicyclists. The following 
improvements are planned: (1) Construct a new 321-ft (98-m) long bridge 
with two 12-ft (3.6-m) travel lanes; (2) improve pedestrian safety by 
constructing a 5-ft (1.5-m) sidewalk on the north side of the new 
Bridge with pedestrian lighting; (3) improve safety for bicyclists by 
constructing 4-ft (1.2-m) bicycle lanes on each side of the new Bridge; 
and (4) improve the turn radius of the Bridge approach on the west and 
the Bridge alignment with Sandholdt Road on the east by constructing 
the new Bridge 23 m (75 ft) south of the existing structure.
    The Bridge will be supported by two bridge abutments and 3 pairs of 
1.7-m (5.6-ft) diameter columns. Each of the columns will be supported 
by a Cast-In-Shell (CISS) pile of the same diameter. Each CISS pile 
will be installed using standard bridge construction practices. This 
includes the use of a vibratory hammer to drive the piles down into the 
substrate and an impact hammer to drive the piles the last 1.7 m (5.6 
ft) in order to determine if load capacity has been reached.
    The Bridge replacement work will include construction of a 
temporary access trestle for equipment access during construction that 
includes installation of wood pilings, installation of temporary 
supporting framework (falsework) piles, and, later, removal of existing 
wood piles. The piles and trestle deck will be installed at the same 
time and the crane that drives the piles will be mounted on the 
previously constructed portion of the trestle span. The falsework piles 
will be installed in a similar manner. Construction of the access 
trestle and falsework will require a total of approximately 200 piles 
(0.3 to 0.6 m by 15 m (11.8 in. to 24 in. by 49 ft), wood or steel). 
These piles could be installed with a vibratory hammer and/or drop 
(impact) hammer. The time to install each pile will be about 30 to 60 
minutes.
    Construction of the bridge span will require 6 piles (1.7 by 31.75 
m (5.6 by 104 ft)) in the slough and 12 piles (0.61 by 19.05 m (2 by 
62.5 ft)) on the shore, for the abutment foundation. These will be the 
CISS piles. They will be installed using a vibratory hammer and a drop 
(impact) hammer.
    A work barge will be anchored at the Bridge site for approximately 
3 months to assist with the construction of the temporary access 
trestle, which will take about 2 weeks. It will take approximately 2 
weeks to place embankment earthwork, four weeks to drive the bridge 
piles, 3 weeks to drive the falsework piles, and approximately 3 weeks 
to construct the abutments. After the falsework is in place, the 
superstructure will take approximately 36 weeks to construct.
    Once the superstructure is completed, it will take 2 weeks to 
remove the falsework piles, 2 weeks to remove the access trestle, and 
about 4 weeks to remove the existing Bridge. The existing piles will be 
removed from the channel by a crane lifting and applying vibration. 
Additional dilapidated pilings along the adjacent shoreline will be 
removed in a similar manner. These activities will presumably take 
place under a future IHA because they will occur after the subject IHA 
expires.
    The Monterey County DPW has divided the work year into two seasons, 
an in-water period and an out-of-water period. In-water construction is 
limited to the months of June through October, as required by condition 
15 of the California Coastal Commission's Coastal Development Permit 
(CCC CDP). Out-of-water construction activities are defined as any 
activities located above mean high water (MHW), which is +0.61 m (2.0 
ft) at the Sandholdt Road Bridge site. Activities, such as pile 
driving, are considered ``in-water'' regardless of the actual tide 
level at the time of construction. Certain activities, however, are 
classified as both in-water and out-of-water because some portions of 
the activity take place above and below the MHW. Most of the activities 
described in this document are considered ``in-water'' activities. 
Because construction activities have the potential to disturb harbor 
seals moving to and from a haul-out site located about 500-800 m (1640 
to 2625 ft) south of the Bridge along the Old Salinas River, an IHA is 
warranted.

Comments and Responses

    A notice of receipt and request for 30-day public comment on the 
application and proposed authorization was published on August 24, 2004 
(69 FR 51992). During the 30-day public comment period, comments were 
received from the Marine Mammal Commission, Monterey County DPW and one 
individual. The Commission concurs with NMFS' determinations concerning 
the impacts of the proposed activities on harbor seals and California 
sea lions and recommends that the authorization be granted.
    Comment 1: Without providing supporting documentation, the 
individual commenter believes that the project cannot be accomplished 
without killing seals and that the pinniped population estimates are 
flawed. In addition, this person believes that seals have few places 
acceptable to them to live and this construction project will drive 
them from one of these few sites.
    Response: Information was provided in the proposed IHA notice that 
harbor seals are found at 400 to 500 haul-out sites along the mainland 
coast and offshore islands of California. Based on the most recent 
counts, the California stock of the Pacific harbor seal is estimated at 
27,863 (Carretta et al., 2003) having a net annual increase of

[[Page 335]]

approximately 3.5 percent, but are increasing at about 7.7 percent 
annually in Monterey Bay. During Bridge construction, harbor seals will 
not be killed or seriously injured, but may be disturbed on a daily 
basis as they are moving to and from the haul-out site located about 
500-800 m (1640 to 2625 ft) south of the Bridge site. Due to this 
distance, no harbor seals are expected to flush from the haul-out.
    In the project area approximately 35 individuals are known to haul 
out along the Old Salinas River approximately 500 to 800 m (1640 to 
2625 ft) south of the current Bridge location, with more seals 
generally found at about 800 m (2625 ft) or more south of the Bridge 
(J. Harvey, pers. comm). The new Bridge will not eliminate or 
significantly alter haul-out sites. Therefore, as seen at other 
construction sites, although there may be short-term abandonment of 
these haul-out sites due to construction noise, long-term abandonment 
is unlikely. In addition, since these sites are not prime locations for 
pupping and nursing (a prime location is nearby in Elkhorn Slough) and 
in-water work is limited to the period from June through October, it is 
highly unlikely that this project will significantly impact harbor 
seals. As California sea lions do not haul out in this area, no impact 
on sea lion haul-outs is likely.
    Comment 2: The Monterey County DPW had several technical 
corrections to the proposed mitigation measures. First, backup alarms 
are important for public safety and, therefore, cannot be disabled to 
reduce noise levels. Second, the County does not have authority to 
restrict vessel traffic in the vicinity of the Bridge or near the 
pinniped haul-out site, except to limit vessel traffic by County staff 
and contractors. Therefore, Monterey County DPW states, neither of 
these mitigation measures are feasible.
    Response: NMFS has not included in the IHA a requirement to disable 
back-up alarms and has modified the vessel traffic restriction to 
vessels associated with the construction activity itself.
    Comment 3: The Monterey County DPW recommends that the biological 
monitor(s) record noise levels by noting the types of construction 
equipment being used each day and then refer to the table provided in 
the CALTRANS application (which provides the typical noise level for 
each type of equipment). Alternatively, Monterey County DPW recommends 
the monitor could record in-air noise levels with a simple decibel 
meter, but it would be difficult to standardize such measurements in a 
way that would make them meaningful (and in a way that would not 
interfere with the biologist's primary responsibility of monitoring the 
marine mammals).
    Response: NMFS believes that in-air noise levels produced by the 
construction equipment will not cause more than a short-term behavioral 
response by the affected pinnipeds. As a result, noting behavioral 
responses made by the harbor seals to the specific type of equipment 
being used at the time will be sufficient for this activity.
    Comment 4: The Monterey County DPW requests that in-water 
monitoring be restricted to the establishment of in-water buffer zone 
(as described later in this document), as the cost of more frequent 
underwater sound monitoring would be prohibitive.
    Response: As noted in the CALTRANS' application, when pile-driving 
is started, a qualified underwater acoustic monitor will record sound 
pressure levels (SPLs) from the pile driving to determine the distance 
to the 160- and 190-dB re 1 microPa (root-mean-squared or rms) 
isopleths. The measured 160-dB radius will be the new marine mammal 
buffer zone and the 190-dB radius will be the marine mammal safety zone 
for that specific type of activity. This same procedure will be 
followed to establish the appropriate buffer and safety zones for each 
type of loud in-water construction activity (e.g., impact hammer, 
vibratory hammer), different hammer sizes and types of piles (e.g., 
hollow steel, wood). Alternatively, the Monterey County DPW can conduct 
underwater measurements of the loudest in-water activity (presumably 
the largest impact hammer) and use those measurements to establish 
conservative buffer and safety zones for pinnipeds.
    Comment 5: Monterey County DPW requests that the IHA have a delayed 
effectiveness until April 15, 2005, when out-of-water construction work 
is scheduled to start.
    Response: NMFS agrees. Early issuance of an IHA with a delayed 
effectiveness date allows a Holder of an IHA time to incorporate marine 
mammal mitigation measures into work contracts and to establish the 
marine mammal monitoring program.

Description of Habitat and Marine Mammals Affected by the Activity

    A description of the habitat and its associated marine mammals 
affected by the proposed Bridge replacement project can be found in the 
CALTRANS application and in Monterey County DPW Marine Mammal and Bird 
Mitigation Plan (CALTRANS, 2004). Harbor seals routinely move between 
the Old Salinas River, beneath and south of the existing Bridge, and 
the adjoining Moss Landing Harbor, on the north side of the site. 
Approximately 35 individuals are known to haul out along the Old 
Salinas River approximately 500 to 800 m (1640 to 2625 ft) south of the 
current Bridge location, with more seals generally found at about 800 m 
(2625 ft) or more south of the Bridge. California sea lions only 
occasionally transit through the project area, but are not known to 
haul-out in the area.

Marine Mammals

    General information on harbor seals and other marine mammal species 
found in Central California waters can be found in Carretta et al. 
(2002, 2003), which are available at the following URL: https://
www.nmfs.noaa.gov/prot_res/PR2/Stock_Assessment_Program/sars.html. 
Please refer to these documents for information on these species. The 
marine mammals likely to be affected by work in the Bridge area are 
limited to harbor seals and California sea lions. The harbor seal and 
California sea lion are the only marine mammal species expected to be 
found regularly in the Bridge area and are described in detail below.

Harbor Seals

    The California stock of harbor seals is comprised of those seals 
found at the 400 to 500 haul-out sites along the mainland coast and 
offshore islands of California. Based on the most recent counts, the 
California stock of the Pacific harbor seal is estimated at 27,863 
(Carretta et al., 2003). A rapid increase in harbor seal abundance was 
recorded from 1972 to 1990, but there has been no net growth along the 
mainland or Channel Islands since 1990. The annual growth rate estimate 
is 3.5 percent, however, the current rate of reproduction is greater 
than this observed rate because fishery mortality takes a fraction of 
the net production (Carretta et al., 2003).
    Harbor seals are considered non-migratory, generally making local 
movements in association with the distribution of food resources, 
tides, weather, season and breeding activities (Bigg, 1973, 1981; 
Stewart and Yochem, 1994). Harbor seals are found in estuaries and 
marine embayments, and typically rest ashore or haul out on beaches and 
tidal-inundated habitats such as mudflats, marshes, and near-shore 
rocky outcroppings (Kopec and Harvey, 1995; Zeiner et al., 1990). They 
often use these isolated, undisturbed sites for pupping, molting, and 
resting.
    Harbor seals are very skittish by nature, and a startle response in 
harbor seals can vary from a temporary state of

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agitation by a few individuals to the permanent abandonment of the 
haul-out site by the entire colony. Normally, when harbor seals are 
frightened by a noise, the approach of a boat, plane, human, predator, 
or another seal, for example, they will move rapidly to the water or 
flush. Disturbances have the potential to cause a more serious effect 
during pupping or nursing, or when aggregations are dense during the 
molting season, as mothers may become separated from their pups or 
individuals may be injured.
    Harbor seals feed opportunistically on a variety of fish, 
crustaceans, and cephalapods (Zeiner et al., 1990). Harbor seals are 
year-round residents in the Monterey Bay area and, contrary to the 
trend noted above for the stock as a whole, Hanan et al. (1992), as 
reported in Harvey (2003), report that the Monterey Bay population is 
increasing at an annual rate of approximately 7.7 percent. Within the 
Monterey Bay area, there are numerous haul-out sites. Several locations 
in Elkhorn Slough are of particular importance, as they provide the 
gently-sloped, isolated, undisturbed conditions critical to harbor 
seals. Within the Sandholdt Road Bridge Replacement project vicinity, 
harbor seals are known to routinely haul out at a recently established 
site, located approximately 800 m (2625 ft) south of the Bridge, along 
the Old Salinas River. This is not a location typically used by harbor 
seals for pupping and nursing, and although such activities could occur 
at the site, it is considered a rare event. Harbor seals may use the 
Old Salinas River haul out during the molting season, but it is 
presumed that long-established alternative sites in this region (i.e. 
along Elkhorn Slough) are more preferable to seals during these 
sensitive time periods. Bridge construction may temporarily restrict a 
small number of harbor seals from using this haul-out site during the 
construction period.

California Sea Lions

    The geographic range of the U.S. stock of the California sea lion 
extends from the U.S./Mexico border north into Canada. Breeding occurs 
only in the Gulf of California, western Baja California, and southern 
California. Population estimates for this stock range from 244,000 to 
237,000. The minimum population size is based on counts of all age and 
sex classes that were ashore at all major rookeries and haul-out sites 
during the 2001 breeding season, the number of births estimated from 
the pup count, and the proportion of the pups in the population. 
Current trends indicate that the stock as a whole has been growing at a 
rate of 5.4 to 6.1 percent per year (Carretta et al., 2003). The 
Monterey Bay population is reported to be increasing at a slightly 
higher rate of 6 to 8 percent (Harvey, 2003).
    California sea lions are the most abundant pinniped in the Monterey 
Bay region, with the highest numbers occurring during the spring and 
fall migrations (MBA, 1999). At least 12,000 California sea lions may 
be present within the entire Monterey Bay National Marine Sanctuary at 
any one time (Harvey, 2003), although only a few individuals are 
typically present within the Moss Landing Harbor-Sandholdt Road Bridge 
Project area (S. Dearn pers. comm.). Most of the sea lions within the 
region are males of varying age classes that arrive in early fall from 
their southern breeding grounds (MBA, 1999). Many individuals remain 
over the course of the winter until the following spring, with just a 
few sea lions staying through the summer. There are no breeding areas 
for the California sea lion located in the Monterey Bay area, and most 
individuals migrate to offshore breeding sites in southern California 
and Mexico.

Potential Effects on Marine Mammals

    The impact to harbor seals and California sea lions is expected to 
be disturbance by the presence of workers, construction noise, and 
construction vessel traffic. The crane used to construct the access 
trestle will generate a moderate degree of noise (similar to that of a 
diesel truck). Pile driving will be noisier and will also cause ground 
vibrations. Vibratory hammers usually create less noise than pile 
driving, but noise will also be created by rock drills, other tools and 
also several of the vehicles commonly used on construction sites. The 
pile drivers planned for use at the Bridge have energy levels of 
approximately 16-24 kiloJoules (kJ). This is significantly less energy 
than either of the pile drivers being used on the San Francisco-Oakland 
Bay Bridge (SF-OBB)(see 68 FR 64595, November 14, 2003), which are 500 
kJ and 1700 kJ. As a result, airborne and underwater impact zones for 
marine mammals (and other estuarine life) will be significantly smaller 
than at SF-OBB. At a distance of 50 ft (15.2 m) from the specific 
activity, CALTRANS believes airborne noise levels from the pile driver 
(and other construction equipment) will not exceed 100 dBA and most 
sounds will be 90 dBA or lower at that distance. Previously, NMFS has 
determined that sound exposure levels (SELs) of 100 dBA and 90 dBA (re 
20 micro-Pa\2\ -sec) or greater are the levels where California sea 
lions (and northern elephant seals) and Pacific harbor seals, 
respectively, will sometimes be harassed. Pinnipeds inside these 
airborne SEL isopleths at the time of pile driving and other equipment 
activity are presumed to be harassed, whether or not an actual 
behavioral disturbance occurs. NMFS does not believe that any airborne 
sounds from the Bridge construction site are sufficient to cause Level 
A harassment (injury or potential therefor). However, harbor seals and 
possibly some California sea lions may be disturbed on a daily basis as 
they are moving within the area and harbor seals are transiting to and 
from the haul-out site located about 500-800 m (1640 to 2625 ft) south 
of the Bridge site. Moreover, due to the distance between the 
construction site and the haul-out, no harbor seals are expected to be 
disturbed sufficiently to cause them to flush from the haul-out.
    In addition to airborne sounds, loud underwater sounds, such as 
those produced by in-water pile driving, can have detrimental effects 
on marine mammals, causing stress, changes in behavior, and 
interference with communication and predator/prey detection. The most 
significant detrimental effect that loud underwater noises can have on 
marine mammals is a temporary or permanent loss of hearing.
    Based on studies, previous pile-driving projects, consultation with 
experts, and review of the literature, NMFS has determined that marine 
mammals may exhibit behavioral changes when exposed to underwater 
impulse SPLs of 160 dB re 1 microPa (rms). In addition, current NMFS 
policy is that underwater SPLs at 190 dB re 1 micro-Pa RMS (impulse) 
and above could cause temporary or permanent hearing impairment in 
harbor seals and sea lions and therefore, activities should be designed 
to ensure, to the greatest extent practicable, that pinnipeds are not 
exposed to SPLs greater than 190 dB dB re 1 microPa rms.
    While disturbances can consist of head alerts, approaches to the 
water, and flushes into the water, only the latter behavior is 
considered by NMFS to be Level B harassment in this situation. During 
the in-water work period (June through October), the incidental 
harassment of harbor seals is expected to occur on a daily basis upon 
initiation of the work. During the out-of-water work period, incidental 
harassment of harbor seals is expected to occur less frequently than 
what is expected for in-water construction activities. In addition, the 
number of seals disturbed will vary daily

[[Page 337]]

depending upon tidal elevations. Although California sea lions have 
been shown to react to pile driving noise by porpoising quickly away 
from other bridge construction sites (SRS Technologies, 2001), it is 
not known whether they will react to general construction noise and 
move away from the area during construction activities. However, sea 
lions are generally thought to be more tolerant of human activities 
than harbor seals and are, therefore, less likely to be affected. 
However, Level B harassment of California sea lions may occur on rare 
occasions during the in-water work and out-of-water work periods.
    However, disturbance from these activities is expected to have no 
more than a short-term negligible impact on the affected species or 
stocks and will result in harassment takes of small numbers of harbor 
seals and sea lions. These disturbances will be reduced to the lowest 
level practicable by implementation of the work restrictions and 
mitigation measures (see Mitigation).

Potential Effects on Habitat

    The activities are expected to result in a temporary reduction in 
utilization of the Old Salinas River haulout site while work is in 
progress or until seals acclimate to the disturbance. This will not 
likely result in any permanent reduction in the number of seals at the 
Old Salinas River haul out. Permanent abandonment of the haul-out site 
is not anticipated since traffic noise from the Bridge, commercial 
activities along the river front area, and recreational boating that 
currently occurs within the area have not caused long-term abandonment. 
In addition, mitigation measures and work restrictions are designed to 
preclude abandonment. Therefore, as described in detail in the CALTRANS 
(2004), other than the potential short-term abandonment by harbor seals 
of part or all of the Old Salinas River haul-out site during Bridge 
construction, no impact on the habitat or food sources of marine 
mammals are likely from this construction project.

Mitigation

    Among other local, state and Federal requirements, the Monterey 
County DPW marine mammal (and bird) mitigation plan was prepared to 
comply with condition 8 of the Monterey County Coastal Development 
Permit and the CCC CDP. The access trestle and falsework piles will be 
located such that they do not pose more of a barrier to marine mammals 
than do the support structures for the existing Bridge. In addition, 
construction barges and/or other in-water support construction 
equipment will be located in an area that would not restrict the 
movements of harbor seals or California sea lions through the work 
area.
    To minimize underwater noise levels, the loudest pile-driving 
activities will be restricted to low-water periods. The loudest in-
water noise levels are expected to occur during pile driving of the 6 
large CISS piles with an impact hammer (driving steel piles is much 
louder than driving wooden piles, and an impact hammer is much louder 
than a vibratory hammer). As a result, the following mitigation 
measures will apply to pile driving: (1) for the two CISS piles in the 
deeper channel area, the impact hammer will not be used when water 
depth is more than 5 ft (1.5 m); and (2) for the other 4 CISS piles, 
the impact hammer will be used when the water depth is more than 3 ft 
(1 m).
    Several mitigation measures to reduce the potential for general 
noise have been implemented by the Monterey County DPW as part of their 
activity. General restrictions include: piles will only be driven 
during daylight hours and all in-water support equipment will be 
located so as not to restrict marine mammal movement.
    To minimize potential harassment of marine mammals to the lowest 
level practicable, the following mitigation measures are also required: 
(1) limit all in-water construction activity (as described in the 
Marine Mammal and Bird Mitigation Plan (Monterey County DPW, 2004)) to 
the period from June 1 through October 31, and (2) minimize Bridge 
construction-related vessel traffic to the greatest extent practicable 
in the in-water buffer zone (described in the next paragraph) when 
conducting in-water construction activities and to the greatest extent 
practicable near the haul-out site.
    Underwater sound measurements have not been made for the pile 
driving equipment planned for use at the Bridge. Until the distance at 
which underwater sound levels equal 160 db and 190 dB re 1 microPa rms 
can be determined and implemented, Monterey County DPW will establish a 
preliminary in-water marine mammal impact zone, delineated by a 500-ft 
(152-m) radius from the in-water construction activity. The preliminary 
in-water, 500-ft (152-m) impact zone will be clearly marked by highly 
visible stakes securely placed on the banks.
    Once pile-driving has started, a qualified underwater acoustic 
monitor will record SPLs from the pile driving to determine the 
distance to 160- and 190-dB re 1 microPa rms isopleths. When these 
radii are established, they will replace the 500-ft (152-m) impact zone 
and will be used as the 160-dB pinniped buffer and 190-dB pinniped 
safety zones. This same procedure will be followed to establish the 
appropriate buffer and safety zones for each type of loud in-water 
construction activity (e.g., impact hammer, vibratory hammer), 
different hammer sizes and types of piles (e.g., hollow steel, wood). 
The 160-dB radius will be called the pinniped buffer zone and the 190-
dB radius will be called the pinniped safety zone for the specific type 
of activity currently underway. Alternatively, under the IHA, the 
Monterey County DPW can conduct underwater measurements of only the 
loudest in-water activity (presumably the largest impact hammer) and 
use those measurements to establish conservative buffer and safety 
zones for pinnipeds. The new safety zones will be clearly marked by 
highly visible stakes and the stakes delineating the initial 500-ft 
(152-m) impact zone will be removed.
    Each day, before pile-driving (or other loud in-water construction 
activity) begins, the marine mammal monitor will survey the appropriate 
impact, buffer and/or safety zones for harbor seals and California sea 
lions. If any pinnipeds are sighted within the impact or safety zones, 
the monitor will require the contractor to delay pile-driving until the 
monitor determines that the marine mammal(s) has moved beyond the 
impact or safety zone, either through sighting or by waiting until 
enough time has elapsed (about 15 minutes) to assume that the animal 
has moved beyond the safety zone. However, once pile driving has begun, 
that individual pile can be driven to depth without cessation 
notwithstanding any pinniped presence.
    Other in-water and out-of-water construction activities not related 
to pile driving, such as the use of heavy equipment to place embankment 
earthwork and rock slope protection, construct bridge abutments and the 
superstructure, and complete the roadway and embankment structural 
section (i.e., activities not involving loud, impulsive hammering 
sounds), will generate noise levels equivalent to that of a diesel 
truck. For these activities, a 50-ft (15.2-m) radius impact zone will 
be established if that radius extends into the water. This pinniped 
impact zone will be clearly marked by highly visible stakes securely 
placed into the banks.
    Each day before non-pile driving construction begins, the monitor 
will search the 50-ft (15.2-m) impact zone for marine mammals. If a 
marine

[[Page 338]]

mammal is sighted within the impact zone, the monitor will require the 
contractor to delay in-water or out-of-water construction activities 
until the monitor determines that no marine mammals are present within 
the impact zone.

Monitoring

    In addition to monitoring and recording behavioral responses within 
the 50-ft (15.2-m) pinniped impact zone, the preliminary 500-ft (152-m) 
pinniped impact zone, and the buffer and safety zones, NMFS is 
requiring the Monterey County DPW to monitor the impact of Bridge 
replacement construction activities on harbor seals (and California sea 
lions, if present) at the Old Salinas River haul-out site. In addition 
to specific monitoring tasks mentioned herein, all biological 
monitor(s) will record general construction activity (including all 
equipment being used), location, duration, and standardized noise 
levels for the construction equipment.
    Monitoring will be divided into the in-water and out-of-water 
construction periods. Monitoring will be conducted every day during in-
water construction activities and for an 8-hour period once a week 
during out-of-water activities, by at least one trained, NMFS-approved, 
biological monitor. The following data will be recorded: (1) Number of 
seals and sea lions on site; (2) date; (3) time; (4) tidal height; (5) 
number of adults, subadults, and pups; (6) number of females and males; 
(7) number of molting seals; and (8) details of any observed 
disturbances. The monitor(s) will conduct baseline observations of 
pinniped behavior at the Old Salinas River haul-out site, once a day 
for a period of 5 consecutive days immediately before the initiation of 
construction in the area to establish pre-construction behavioral 
patterns. In addition, NMFS requires that, immediately following the 
completion of the construction of the Bridge, the monitor(s) will 
conduct observations of pinniped behavior at the Old Salinas River haul 
out, for at least 5 consecutive days for approximately 1 tidal cycle 
(high tide to high tide) each day.

Reporting

    NMFS will be notified in writing within 10 working days of any 
changes to the impact, buffer and safety zones due to completion and 
analysis of the SPL measurements.
    The Monterey County DPW will provide weekly reports to the 
Southwest Regional Administrator (Regional Administrator), NMFS, 
including a summary of the previous week's monitoring activities and an 
estimate of the number of pinnipeds that may have been disturbed as a 
result of Bridge replacement construction activities. These reports 
will provide dates, time, tidal height, maximum number of harbor seals 
ashore, number of adults, sub-adults and pups, number of females/males, 
and any observed disturbances. The Monterey County DPW will also 
provide a description of construction activities at the time of 
observation and any SPL measurements made at the haulout site. The 
Monterey County DPW must submit draft final reports to NMFS within 90 
days of completion of the 2005 in-water work phase and the 2005/2006 
out-of-water work phase. The draft interim reports are considered final 
reports unless NMFS requests modifications to those reports within 90 
days of receipt. The Monterey County DPW will also provide NMFS with a 
follow-up report on the post-construction monitoring activities within 
18 months of project completion in order to evaluate whether haulout 
patterns are similar to the pre-Bridge replacement haul-out patterns at 
the Old Salinas River site.

Endangered Species Act (ESA)

    NMFS has determined that this action will have no effect on species 
listed under the ESA that are under the jurisdiction of NMFS. On April 
12, 2000, the U.S. Fish and Wildlife Service (USFWS) concurred with the 
determination of the FHWA that the proposed Bridge project was not 
likely to adversely affect the federally endangered goby 
(Eucyclobgobius newberryi), the brown pelican (Pelecanus occidentalis) 
and southern sea otter (Enhydra lutris nereis). However, issuance of an 
IHA to the Monterey County DPW also constitutes an agency action 
subject to section 7 of the ESA. As the effects of the Bridge 
activities on listed species were analyzed earlier, and as the action 
has not changed from that considered in that informal consultation, the 
discussion of effects that is contained in the April 12, 2000 
concurrence letter from the USFWS to the FHWA pertains also to this 
action. In conclusion, NMFS has determined that issuance of an IHA does 
not lead to any effects to listed species apart from those that were 
considered in the consultation on FHWA's action.

National Environmental Policy Act (NEPA)

    NMFS has prepared an Environmental Assessment (EA) on this action 
and has made a Finding of No Significant Impact (FONSI). Therefore, 
preparation of an environmental impact statement on this action is not 
required. A copy of the EA and FONSI are available upon request (see 
ADDRESSES).

Conclusions

    NMFS has determined that the Bridge replacement, as described in 
this document, should result, at worst, in the temporary modification 
in behavior of small numbers of harbor seals and, possibly, of small 
numbers of California sea lions. While behavioral modifications, 
including temporarily vacating the haulout, may be made by these 
species to avoid the resultant visual and acoustic disturbance, this 
action is expected to have a negligible impact on the affected species 
and stocks of pinnipeds. 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 described 
in this document.

Authorization

    For the reasons previously discussed, NMFS has issued an IHA for a 
1-year period, for the incidental harassment of small numbers of harbor 
seals and California sea lions incidental to Bridge replacement 
construction, provided the previously mentioned mitigation, monitoring, 
and reporting requirements are incorporated.

    Dated: December 27, 2004.
Donna Wieting,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 05-97 Filed 1-3-05; 8:45 am]
BILLING CODE 3510-22-S