02-5101. Small Takes of Marine Mammals Incidental to Specified Activities; Harbor Activities at Vandenberg Air Force Base, CA

AGENCY:

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

ACTION:

Notice of receipt of application and proposed authorization for incidental harassment of marine mammals; request for comments.

SUMMARY:

NMFS has received a request from the Department of the Air Force, 30^th Space Wing, on behalf of The Boeing Company (Boeing) for an authorization to take small numbers of marine mammals by harassment incidental to harbor activities related to the Delta IV/Evolved Expendable Launch Vehicle (EELV) at south Vandenberg Air Force Base, CA (VAFB). Under the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposal to authorize Boeing to incidentally take, by harassment, small numbers of Pacific harbor seals at south VAFB beginning in mid-March 2002.

DATES:

Comments and information must be received no later than April 3, 2002.

ADDRESSES:

Comments on the application should be addressed to Donna Wieting, Chief, Marine Mammal Conservation Division, Office of Protected Resources, NMFS, 1315 East-West Highway, Silver Spring, MD 20910-3225. Comments will not be accepted if submitted via e-mail or the Internet. A copy of the application may be obtained by writing to this address or by telephoning one of the contacts listed here.

FOR FURTHER INFORMATION CONTACT:

Simona P. Roberts, [phone], ext. 106 or Christina Fahy, [phone].

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 for incidental takings 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. The MMPA defines “harassment” as:

...any act of pursuit, torment, or annoyance which

(a) has the potential to injure a marine mammal or marine mammal stock in the wild (“Level A harassment”); or

(b) 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, 2001, NMFS received an application from the 30th Space Wing on behalf of Boeing requesting an authorization for the harassment of small numbers of Pacific harbor seals incidental to harbor activities related to the Delta IV/EELV, including: wharf modification, transport vessel operations, cargo movement activities, and harbor maintenance dredging. The harbor where activities will take place is on south VAFB approximately 2.5 miles south of Point Arguello, CA, and approximately 1 mile north of the nearest marine mammal pupping site (i.e., Rocky Point).

Specified Activities

Modifications to the existing wharf are needed to accommodate the specially designed transport vessel, the Delta Mariner, that will be used for delivering the Delta IV/EELV's common booster core (CBC). These modifications involve removing portions of the wharf surface, re-surfacing the wharf with concrete and stainless steel rub-rails, and construction of a ramp on the seaward portion of the wharf. Equipment to be used includes: a skip-loader, concrete saw, concrete ready-mix truck, and dump truck. Measured noise levels of equivalent heavy equipment ranged from 61 dB A-weighted (quietest measurement from clamshell dredge measurement) to 81 dB A-weighted (loudest measurement from roll-off truck transporter) at a distance of 76.2 meters (m) (250 feet, ft). (Acentech, 1998). These wharf modifications are scheduled to begin in mid-March 2002 for a 6-week period.

Delta Mariner CBC off-loading operations and associated cargo movement activities will occur a maximum of 6 times per year, with the first Mariner visit scheduled for April 2002 and the first off-load operation for August 2002. The Delta Mariner is a 95.1 m (312 ft) long, 25.6 m (84 ft) wide steel hull ocean-going vessel capable of operating at a 2.4 m (8 ft) draft. For the first few visits to the south VAFB harbor, tug boats will accompany the Mariner. Sources of noise from the Delta Mariner vessel include ventilating propellers used for maneuvering into position and the cargo bay door when it becomes disengaged. Removal of the CBC from the Mariner requires use of an Elevating Platform Transporter (EPT). The EPT is an additional source of noise, with sound levels measured at a maximum of 82 dB A-weighted 6.1 m (20 ft) from the engine exhaust (Acentech, 1998). EPT operation procedures require 2 short (approximately 1/3 seconds) beeps of the horn prior to starting the ignition. At 60.9 m (200 ft) away, the sound level of the EPT horn ranged from 62-70 dB A-weighted. Containers containing flight hardware items will be towed off the Mariner by a tractor tug that generates a sound level of approximately 87 dB A-weighted at 15.2 m (50 ft) while in operational mode. Total time of Mariner docking and cargo movement activities is estimated at between 14 and 18 hours in good weather.

To accommodate the Delta Mariner, the harbor will need to be dredged to a working depth of approximately 3.0 m (10 ft) mean lower low water level plus a 0.61 m (2 ft) over-dredge. Dredging of the harbor will involve the use of heavy equipment, including a clamshell dredge, dredging crane, a small tug, dredging barge, dump trucks, and a skip loader. Measured sound levels from this equipment are roughly equivalent to those estimated for the wharf modification equipment: 61-81 dB A-weighted at 76.2 m (250 ft). Dredge operations, from set-up to tear-down, would continue 24-hours a day for 3-5 weeks. The frequency of maintenance dredging will be based on fill rate surveys conducted periodically during the first year following the initial dredge to determine the sedimentation rate. Boeing expects maintenance dredging would likely be required every 2-3 years.

A more detailed description of the work proposed for 2002 is contained in the application which is available upon request (see ADDRESSES) and in the Final US Air Force Environmental Assessment for Harbor Activities Associated with the Delta IV Program at Vandenberg Air Force Base (ENSR International, 2001).

Description of Habitat and Marine Mammals Affected by the Activity

The only marine mammal species likely to be harassed incidental to harbor activities at south VAFB is the Pacific harbor seal (Phoca vitulina richardsi). The most recent estimate of the Pacific harbor seal population in California is 30,293 seals (Forney et al., 2000). From 1979 to 1995, the California population increased at an estimated annual rate of 5.6 percent. The total population of harbor seals on VAFB is now estimated to be 1,040 (775 on south VAFB) based on sighting surveys and telemetry data (SRS Technologies 2001).

The daily haul-out behavior of harbor seals along the south VAFB coastline is dependent on time of day rather than tide height. The highest number of seals haul-out at south VAFB between 1100 through 1700 hours. In addition, haul-out behavior at all sites seems to be influenced by environmental factors such as high swell, tide height, and wind. The combination of all three may prevent seals from hauling out at most sites. The number of seals hauled out at any site can vary greatly from day to day based on environmental conditions. Harbor seals occasionally haul out at a beach 76.2 m (250 ft) west of the south VAFB harbor and on rocks outside the harbor breakwater where Boeing will be conducting wharf modification, Delta Mariner operations, cargo loading, and dredging activities. The maximum number of seals present during past dredging of the harbor was 23, with an average of 7 seals sighted per day. The harbor seal pupping site closest to south VAFB harbor is at Rocky Point, approximately 1.6 kilometers (km) (1 mile, mi) north.

Several factors affect the seasonal haul-out behavior of harbor seals including environmental conditions, reproduction, and molting. Harbor seal numbers at VAFB begin to increase in March during the pupping season (March to June) as females spend more time on shore nursing pups. The number of hauled-out seals is at its highest during the molt which occurs from May through July. During the molting season, tagged harbor seals at VAFB increased their time spent on shore by 22.4 percent; however, all seals continued to make daily trips to sea to forage. Molting harbor seals entering the water because of a disturbance by a space vehicle launch or another source are not adversely affected in their ability to molt and do not endure thermoregulatory stress. During pupping and molting season, harbor seals at the south VAFB sites expand into haul-out areas that are not used the rest of the year. The number of seals hauled out begins to decrease in August after the molt is complete and reaches the lowest number in late fall and early winter.

Three other marine mammal species are known to occur infrequently along the south VAFB coast during certain times of the year and are unlikely to be harassed by Boeing's activities. These three species are: the California sea lion (Zalophus californianus), northern elephant seal (Mirounga angustirostris) and northern fur seal (Callorhinus ursinus). Descriptions of the biology and local distribution of these species can be found in the application as well as other sources such as Stewart and Yochem (1994, 1984), Forney et al. (2000), Koski et al. (1998), Barlow et al. (1993), Stewart and DeLong (1995), and Lowry et al. (1992). Please refer to those documents for information on these species.

Potential Effects of Activities on Marine Mammals

Acoustic and visual stimuli generated by the use of heavy equipment during the wharf modifications, Delta Mariner and off-loading operations, and dredging, as well as the increased presence of personnel, may cause short-term disturbance to harbor seals hauled out along the beach and rocks in the vicinity of the south VAFB harbor. This disturbance from acoustic and visual stimuli is the principal means of marine mammal taking associated with these activities. Based on the measured sounds of construction equipment, such as might be used during Boeing's activities, sound levels from all equipment drops to a maximum level of 95 dB A-weighted within 50 ft (15.2 m) of the sources. In contrast, the ambient background noise measured approximately 76.2 m (250 ft) from the beach was estimated to be 35-48 dB A-weighted (Acentech, 1998; EPA, 1971).

Pinnipeds sometimes show startle reactions when exposed to sudden brief sounds. An acoustic stimulus with sudden onset (such as a sonic boom) may be analogous to a “looming” visual stimulus (Hayes and Saif, 1967), which may elicit flight away from the source (Berrens et al., 1988). The onset of operations by a loud sound source, such as the EPT during CBC off-loading procedures, may elicit such a reaction. In addition, the movements of cranes and dredges may represent a “looming” visual stimulus to seals hauled out in close proximity. Seals exposed to such acoustic and visual stimuli may either exhibit a startle response or leave the haul-out site.

According to the MMPA, when harbor activities disrupt the behavioral patterns of harbor seals, they are considered to be taken by harassment. In general, if the received level of the noise stimulus exceeds both the background (ambient) noise level and the auditory threshold of the animals, and especially if the stimulus is novel to them, then there may be a behavioral response. The probability and degree of response will also depend on the season, the group composition of the pinnipeds, and the type of activity in which they are engaged. Minor and brief responses, such as short-duration startle or alert reactions, are not likely to result in disruption of behavioral patterns, such as migration, nursing, breeding, feeding, or sheltering (i.e., Level B harassment) and will not cause serious injury or mortality to marine mammals. On the other hand, startle and alert reactions accompanied by large-scale movements, such as stampedes into the water, may have adverse effects on individuals and would be considered a take by harassment due to disruption of behavioral patterns. In addition, such large-scale movements by dense aggregations of marine mammals or on pupping sites, could potentially lead to takes by serious injury or death. However, there is no potential for large-scale movements leading to serious injury or mortality near the south VAFB harbor, since on average the number of harbor seals hauled out near the site is less than 30 and there is no pupping at nearby sites. The effects of the harbor activities are expected to be limited to short-term startle responses and localized behavioral changes (i.e., Level B harassment).

For a further discussion of the anticipated effects of the planned activities on harbor seals in the area, please refer to the application and ENSR International's 2001 Final Environmental Assessment. Information in the application and referenced sources is preliminarily adopted by NMFS as the best information available on this subject.

Numbers of Marine Mammals Expected to Be Harassed

Boeing estimates that a maximum of 30 harbor seals per day may be hauled out near the south VAFB harbor, with a daily average of 7 seals sighted during previous dredging operations in the harbor. Using the maximum and average number of seals hauled out per day, assuming that half of the seals will use the site at least twice, assuming that half of the seals hauled out will react to the activities, and using a maximum total of 83 operating days in 2002-2003, NMFS calculates that between 623 and 145 Pacific harbor seals may be subject to Level B harassment, as defined in 50 CFR 216.3.

Possible Effects of Activities on Marine Mammal Habitat

Boeing anticipates no loss or modification to the habitat used by Pacific harbor seals that haul out near the south VAFB harbor. The harbor seal haul-out sites near south VAFB harbor are not used as breeding, molting, or mating sites; therefore, it is not expected that the activities in the harbor will have any impact on the ability of Pacific harbor seals in the area to reproduce.

Possible Effects of Activities on Subsistence Needs

There are no subsistence uses for Pacific harbor seals in California waters, and, thus, there are no anticipated effects on subsistence needs.

Mitigation

No pinniped mortality and no significant long-term effect on the stocks of pinnipeds hauled out near south VAFB harbor are expected based on the relatively low levels of sound generated by the equipment to be used during Boeing's harbor activities (maximum level of 95 dB A-weighted within 50 ft (15.2 m)) and the relatively short time periods over which the project will take place (totaling approximately 83 days). However, Boeing expects that the harbor activities may cause disturbance reactions by some of the harbor seals hauled out on the adjacent beach and rocks. To reduce the potential for disturbance from visual and acoustic stimuli associated with the activities Boeing will undertake the following marine mammal mitigating measures:

(1) If activities occur during nighttime hours, lighting will be turned on before dusk and left on the entire night to avoid startling harbor seals at night.

(2) Activities should be initiated before dusk.

(3) Construction noises must be kept constant (i.e., not interrupted by periods of quiet in excess of 30 minutes) while harbor seals are present.

(4) If activities cease for longer than 30 minutes and harbor seals are in the area, start-up of activities will include a gradual increase in noise levels.

(5) A qualified marine mammal observer will visually monitor the harbor seals on the beach adjacent to the harbor and on rocks for any flushing or other behaviors as a result of Boeing's activities. If flushing results, then the activities suspected of causing the seals to enter the water will be delayed until the seals leave the area.

(6) The Delta Mariner and accompanying vessels will enter the harbor only when the tide is too high for harbor seals to haul-out on the rocks.

(7) As alternate dredge methods are explored, the dredge contractor may introduce quieter techniques and equipment.

Monitoring

As part of its application, Boeing provided a proposed monitoring plan for assessing impacts to harbor seals from the activities at south VAFB harbor and for determining when mitigation measures should be employed.

A NMFS-approved and VAFB-designated biologically trained observer will monitor the area for harbor seals during all harbor activities. During nighttime activities, the harbor area will be lit and the monitor will use a night vision scope. Monitoring activities will consist of:

(1) Conducting baseline observation of harbor seals in the project area prior to initiating project activities.

(2) Conducting and recording observations on harbor seals in the vicinity of the harbor for the duration of the activity occurring when tides are low enough for harbor seals to haul out (+ 2 ft. or less).

(3) Conducting post-construction observations of harbor seal haul-outs in the project area to determine whether animals disturbed by the project activities return to the haul-out.

As required by the MMPA, this monitoring plan will be subject to a review by technical experts prior to formal acceptance by NMFS.

Reporting

Boeing will notify NMFS 2 weeks prior to initiation of each activity. After each activity is completed, Boeing will provide a report to NMFS within 90 days. This report will provide dates and locations of specific activities, details of seal behavioral observations, and estimates of the amount and nature of all takes of seals by harassment or in other ways. In the unanticipated event that any cases of pinniped mortality are judged to result from these activities, this will be reported to NMFS immediately.

Consultation

Boeing has not requested the take of any listed species. Therefore, NMFS has determined that a section 7 consultation under the Endangered Species Act is not required at this time.

Conclusions

NMFS has preliminarily determined that the impact of harbor activities related to the Delta IV/EELV at VAFB, including: wharf modification, transport vessel operations, cargo movement activities, and harbor maintenance dredging, will result, at worst, in a temporary modification in behavior by Pacific harbor seals. While behavioral modifications may be made by these species to avoid the resultant acoustic and visual stimuli, there is no potential for large-scale movements, such as stampedes, since harbor seals haul out in such small numbers near the site (maximum hauled out in one day estimated at 30 seals). The effects of the harbor activities are expected to be limited to short-term and localized behavioral changes. Therefore, NMFS preliminarily concludes that the effects of the planned demolition activities will have no more than a negligible impact on pinnipeds.

Due to the localized nature of these activities, the number of potential takings by harassment are estimated to be small. In addition, no take by injury and/or death is anticipated, and the potential for temporary or permanent hearing impairment is unlikely given the low noise levels and will be entirely avoided through the incorporation of appropriate mitigation measures. No rookeries, mating grounds, areas of concentrated feeding, or other areas of special significance for marine mammals occur within or near south VAFB harbor.

Proposed Authorization

NMFS proposes to issue an IHA to Boeing for harbor activities related to the Delta IV/EELV to take place at south Vandenberg Air Force Base, CA, (VAFB) over a 1-year period. The proposal to issue this IHA is contingent upon adherence to the previously mentioned mitigation, monitoring, and reporting requirements. NMFS has preliminarily determined that the proposed activity would result in the harassment of only small numbers of harbor seals; would have no more than a negligible impact on these marine mammal stocks; and would not have an unmitigable adverse impact on the availability of marine mammal stocks for subsistence uses.

Information Solicited

NMFS requests interested persons to submit comments and information concerning this request (see ADDRESSES).

Dated: February 26, 2002.

David Cottingham,

Deputy Office Director, Office of Protected Resources, National Marine Fisheries Service.