[Federal Register Volume 67, Number 69 (Wednesday, April 10, 2002)]
[Notices]
[Pages 17409-17412]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-8692]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 030402C]


Small Takes of Marine Mammals Incidental to Specified Activities; 
Seismic Retrofit Project in Humboldt County, CA

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

ACTION: Notice of receipt of application and proposed incidental 
harassment authorization; request for comments.

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SUMMARY: NMFS has received a request from the California Department of 
Transportation (CALTRANS) for an authorization to take small numbers of 
marine mammals by harassment incidental to a project to seismically 
retrofit three bridges at Humboldt Bay in Humboldt County, CA. Under 
the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on 
its proposal to authorize CALTRANS to incidentally take, by harassment, 
small numbers of Pacific harbor seals in Humboldt Bay for a 1-year 
period.

DATES: Comments and information on CALTRANS' request and NMFS' proposal 
must be received no later than May 10, 2002.

ADDRESSES: Comments on the request and proposed authorization should be 
addressed to Donna Wieting, Chief, Marine Mammal Conservation Division, 
Office of Protected Resources, 1315 East-West Highway, Silver Spring, 
MD 20910-3282. Copies of CALTRANS' request may be obtained by writing 
to this address or by telephoning one of the contacts listed below. 
Comments will not be accepted if submitted via e-mail or the Internet.

FOR FURTHER INFORMATION CONTACT: Simona Perry Roberts, Office of 
Protected Resources, (301) 713-2322 ext. 106 or Christina Fahy, 
Southwest Regional Office, (562) 980-4023.

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.

[[Page 17410]]

    Subsection 101(a)(5)(D) of the MMPA established an expedited 
process by which citizens of the United States can apply for an 
authorization to incidentally take small numbers of marine mammals by 
harassment. The MMPA 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.

Summary of Request

    On January 28, 2002, NMFS received a request from CALTRANS for an 
IHA to incidentally take, by harassment, small numbers of Pacific 
harbor seals (Phoca vitulina richardsii) during a project to 
seismically retrofit three bridges in Humboldt County, CA.

Project Description

    The purpose of the project is to reduce the safety hazard caused by 
probable seismic activity through reinforcement of bridge footings and 
encasing of pier columns. Work will be on three bridges spanning 
Humboldt Bay, the Eureka Channel Bridge (ECB), Middle Channel Bridge 
(MCB), and the Samoa Channel Bridge (SCB). In general, work on the 
three bridges will include: driving 0.91 meter (m) (36 inch, in) and 
1.52 m (60 in) diameter cast-in-steel shell (CISS) piles; placement of 
reinforced concrete casings at each pier column; concrete topping of 
each pier; construction and removal of temporary trestles; installation 
and removal of cofferdams; placement and removal of silt curtains; and, 
movements of shallow draft barges and tender boats. Because work will 
be simultaneous at all three bridges there is a high likelihood that 
more than one pile driving episode will be occurring in the Bay at any 
given time. CALTRANS estimates work will last approximately 560 days on 
an 8-hour a day, 5 day a week work schedule. The project start date is 
scheduled for summer of 2002 and the entire project will end in the 
winter of 2004. The proposed IHA will only authorize the incidental 
take of marine mammals for a 1-year period.

Marine Mammal Species Potentially Impacted

    Pacific harbor seals are the most abundant marine mammal species 
found within Humboldt Bay. Seals are regularly seen within the three 
channels: Eureka, Middle, and Samoa. Their average abundance increases 
in the winter and spring (Andrea Gemmer, unpublished data, Humboldt 
State University, 2001). Two main haul-out locations have been 
identified in North Humboldt Bay, or Arcata Bay, closest to the project 
area. These haul-outs are Daby Island (402 m or a 1/4 mile (mi) North 
of ECB) and Mad River Slough (3.2 kilometers (km) or 2 mi North of 
SCB). Other recognized haul-outs in and near the Bay include: Indian 
Island, mud flats surrounding the terminal ends of Arcata Channel, 
Hookton Channel (12.9 km (8 mi) south of the project), Eel River (19.3 
km (12 mi) south of the project), and the mouth of Mad River (12.9 km 
(8 mi) north of the project).
    Although it is unlikely that any other species of marine mammal 
will be impacted by this CALTRANS project, California sea lions 
(Zalophus californianus) are present near the channel entrance and are 
occasionally seen within the lower Bay and there is a low probability 
that they will be present near the proposed project. However, no known 
California sea lion haul-out sites exist in the upper Bay, islands, or 
in the Eureka, Middle, or Samoa channels.
    General information on Pacific harbor seals, California sea lions 
and other marine mammal species found in California waters can be found 
in Forney et al. (2000) and Barlow et al.(1998).

Potential Impact on Marine Mammals and their Habitat

    At this time, NMFS considers that underwater sound pressure levels 
(SPLs) above 190 dB re 1 micro-Pa RMS (impulse) could cause temporary 
hearing impairment (Level B harassment) in harbor seals and sea lions. 
The effects of elevated SPLs on marine mammals may include avoidance of 
an area, tissue rupture, hearing loss, disruption of echolocation, 
masking, habitat abandonment, aggression, pup abandonment, and 
annoyance. During pile driving, the level of sound produced from the 
impact hammering may be affected by the size and maximum operating 
energy level of the hammer, the size and length of the piles, soil 
conditions, water depth, bathymetry, salinity, and temperature. For the 
Humboldt Bay project described here, pile installation will occur from 
shallow (less than 1 m, 3.28 feet (ft)) to deep (16 m, 52.5 ft) water, 
with several different types and sizes of piles. Low frequency sounds, 
such as those that dominate in pile driving, tend to attenuate more 
rapidly in relatively shallow water (i.e., 6-10 m, 19.7-32.8 ft) than 
in deeper waters. Although underwater SPL measurements for pile driving 
in Humboldt Bay have not been collected and are difficult to estimate, 
marine mammal reactions to previous pile driving activities in other 
geographic locations (i.e., San Francisco Bay) have led CALTRANS to a 
determination that the pile driving outlined in the project description 
has the potential to harass Pacific harbor seals that may be swimming, 
foraging, or resting in the area where activities will be taking place. 
In discussions with Structures Engineering Staff, CALTRANS determined 
that the type and size of pile driver that would be used on the 
Humboldt Bay retrofit project would be comparable to a Delmag Model 
D80-23 with a maximum energy per blow of 635 kiloJoules (kJ) (212,420 
foot pounds (ft.lbs.)) and a minimum energy per blow of 377 kJ (126,192 
ft.lbs.) (CALTRANS, 2002). The impact of the pile driver on the piling 
will result in substantial noise energy propagation within the water 
column. Although there will be attenuation of the noise energy due to 
substrate, currents, other pre-existing piles and other factors, the 
attenuation level is impossible to accurately predict. In their 
request, CALTRANS provided an analysis of the potential 160 dB and 190 
dB re 1 micro-Pa RMS (impulse) noise contours based on the hammer 
energy to be used in Humboldt Bay on the larger diameter (1.52 m, 60 
in) CISS piles and the underwater sound propagation characteristics in 
shallow Humboldt Bay waters. The results of this analysis showed that a 
hammer energy of 635 kJ (212,420 ft.lbs.) would result in a 160 dB 
noise contour at a distance of 670 m (2,198 ft) and a 190 dB noise 
contour at a distance of 185 m (607 ft). For a hammer energy of 377 kJ, 
the results showed that a 160 dB noise contour would occur at a 
distance of 625 m (2,051 ft) and a 190 dB noise contour would occur at 
a distance of 130 m (427 ft). Based on these results, marine mammals 
that are within the 190 dB contour could be subject to temporary 
hearing threshold shift or other non-lethal injury that has the 
potential to cause injury. Marine mammals within the 160 dB contour 
would also be likely

[[Page 17411]]

to demonstrate avoidance behaviors (level B harassment), but would not 
be likely to sustain hearing threshold shifts or other potential 
injuries associated with exposure to a loud sound source. The seals 
most likely to be affected by the pile driving activities would be 
those at the Daby Island haul-out site. Temporary abandonment of this 
one site could occur, but the animals are expected to return once 
construction is completed.
    CALTRANS expects pile driving noise will be substantially less for 
the placement of the small diameter pilings used to support the 
temporary trestles and for the smaller diameter CISS piles that will be 
driven within the cofferdam enclosures. For these smaller pilings (0.91 
m, 36 in), CALTRANS did not conduct calculations of estimated noise 
energy since there is no experimental data available to verify the 
calculations and there are so many different variables, such as water 
depth, proximity to shoreline, substrate, and pile material.
    In addition, noise and visual stimulus resulting from activities 
such as construction, removals of temporary structures, and the 
movement of barges, boats, and people all have the potential to harass 
harbor seals in the area.
    With regard to habitat, temporary structures may provide new haul-
out locations for seals, increasing the potential for harassment of 
marine mammals when construction stops (i.e., at night) and is then re-
initiated (i.e., at sunrise). At the same time, the placement of piles 
will permanently fill a small area of substrate, thus removing a minor 
amount of benthic forage habitat; however, the mid-water structure 
created by pilings may create an additional foraging habitat. This 
minor change in habitat is not likely to affect the harbor seal 
population within Humboldt Bay.

Numbers of Marine Mammals Expected to be Harassed

    Only Pacific harbor seals are expected to be harassed by the 
project. Seals are expected to be present in the construction area and 
impacts are most likely to those animals at the Daby Island haul-out 
site. Due to their irregular occurrence and the intermittent nature of 
the proposed pile driving, CALTRANS did not provide an estimate of the 
number of animals potentially affected. Crude estimates of the average 
seal abundance in the entire North Humboldt Bay area during September 
2000-August 2001 show that the number of animals found in the area 
ranges from 93 to 18 per month. Therefore, NMFS conservatively 
estimates that between 200 to 1,100 harbor seals may be harassed during 
a 1-year period.

Proposed Mitigation Measures

    Attenuation devices such as air blankets and bubble curtains are 
commercially available products that are designed to decrease the noise 
level by placing an air/water interface around the sound source (i.e., 
pile driver). However, due to the high velocity tidal currents within 
the three channels, CALTRANS has determined that these devices will not 
work for mitigating the noise from this project.

Establishment of Safety/Buffer Zones

    Prior to commencement of pile driving involving the large diameter 
pilings (1.52 m or 60 in), safety and buffer zones will be designated 
around each driving site depending on the hammer energy per blow 
predicted. The safety zones will be based on calculations CALTRANS 
provided in its request to NMFS for the 190 dB re 1 micro-Pa RMS 
(impulse) noise contour. That is, for a hammer energy of 635 kJ the 
safety zone will be out to a distance of 185 m (607 ft) and for a 
hammer energy of 377 kJ the safety zone will be out to a distance of 
130 m (427 ft). The safety zone is intended to include all areas where 
the underwater SPLs are anticipated to equal or exceed 190 dB re 1 
micro-Pa RMS (impulse). If marine mammals are seen within the safety 
zone, pile driving must not commence or must stop immediately and not 
restart until the marine mammal has moved beyond the 190 dB contour, 
either verified through sighting by a qualified observer outside the 
contour or by waiting until enough time has elapsed (15 minutes) to 
assume that the animal has moved beyond the safety zone. In addition, a 
buffer zone will be established around large diameter pilings based on 
calculations CALTRANS provided in its request to NMFS for the 160 dB re 
1 micro-Pa RMS (impulse) noise contour. These buffer zones would be 
monitored closely during all pile driving activities for the presence 
and potential disturbance of marine mammals. If marine mammals are 
sighted within these zones, behavior of the mammals would be documented 
by observers and reported to NMFS, but operations would not need to 
cease.

Proposed Monitoring Plan

    Qualified biologist(s) will be present during all CISS pile driving 
to observe for marine mammals in the vicinity of pile driving activity. 
Biological observers will position themselves so that they have an 
unobstructed view up and down the channel. The observer(s) will have 
direct communication with the job foreman so that stop-work and start-
work directions can be relayed effectively. If CISS pile driving is 
occurring at more than one bridge at a time, each bridge location will 
have a biologist assigned to monitor for the presence of marine 
mammals. The observer(s) will record the date, time, location, 
distance, direction of travel, species, approximate age class, type of 
project activity occurring at time of sighting, and apparent behavior 
of marine mammals. Such records will serve as a means for documenting 
the species, numbers, and frequency of marine mammals incidentally 
harassed during the project.

Reporting Requirements

    NMFS' Southwest Regional Administrator will be notified prior to 
the initiation of the East Span Project, and coordination with NMFS 
will occur on a weekly basis, or more often as necessary. Monitoring 
reports will be faxed to NMFS on a monthly basis during pile driving 
activity. The monthly report will include a summary of the previous 
month's monitoring activities and an estimate of the number of seals 
that may have been disturbed as a result of pile driving activities.
    Because the Humboldt Bay project is expected to continue beyond the 
date of expiration of this IHA (under a new IHA or under regulations 
pursuant to section 101(a)(5)(A) of the MMPA), CALTRANS will provide 
NMFS' Southwest Regional Administrator with a draft final report before 
90 days after expiration of this IHA. 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. If no comments are received from 
NMFS, the draft final report will be considered to be the final report.

Preliminary Determination

    NMFS has preliminarily determined that the short-term impact of 
pile driving and other activities associated with the seismic retrofit 
of three bridges in Humboldt Bay in Humboldt County, CA, as described 
in this document, should result, at worst, in the temporary 
modification in behavior of Pacific harbor seals. While behavioral 
modifications, including temporarily vacating haul-out sites and other 
areas, may be made by these species to avoid

[[Page 17412]]

the resultant visual and acoustic disturbance, the availability of 
alternate haul-out sites (including pupping sites) and feeding areas 
within the Bay has led NMFS to the preliminary conclusion that this 
action will have a negligible impact on Pacific harbor seal populations 
in Humboldt Bay and along the California coast.
    In addition, no take by serious injury or death is anticipated and 
harassment takes should be at the lowest level practicable due to 
incorporation of the mitigation measures mentioned previously in this 
document.

Proposed Authorization

    NMFS proposes to issue an IHA to CALTRANS for the potential 
harassment of small numbers of Pacific harbor seals incidental to the 
seismic retrofit of three bridges in Humboldt County, CA provided the 
previously mentioned mitigation, monitoring, and reporting requirements 
are incorporated.

Information Solicited

    NMFS requests interested persons to submit comments, information, 
and suggestions concerning this proposed authorization to Donna 
Wieting, Chief, Marine Mammal Conservation Division, Office of 
Protected Resources, NMFS, 1315 East-West Highway, Silver Spring, MD 
20910-3225.

    Dated: April 3, 2002.
David Cottingham,
Deputy Director, Office of protected Resources, National Marine 
Fisheries Service.
[FR Doc. 02-8692 Filed 4-9-02; 8:45 am]
BILLING CODE 3510-22-S