NOAA 97-R130

Contact: Scott Smullen             FOR IMMEDIATE RELEASE
                                              4/25/97

NOAA SEEKS COMMENT ON APPLICATION AND PROPOSED AUTHORIZATION FOR MARINE MAMMAL DISTURBANCE DURING SEISMIC SURVEY

The National Oceanic and Atmospheric Administration is seeking comment on an application and proposed authorization for BP Exploration (Alaska) of Anchorage to potentially disturb small numbers of marine mammals while conducting a seismic survey in the Western Beaufort Sea in state and federal waters of Alaska.

Under the Marine Mammal Protection Act, BP Exploration applied for a permit to incidentally disturb small numbers of bowhead whales and other marine mammals during an oil and gas survey in the vicinity of the Northstar Unit of the Western Beaufort Sea.

NOAA's National Marine Fisheries Service may grant permission to incidentally harass these mammals if it finds the survey will have a negligible impact on marine mammals and will not halt the availability of some species for subsistence uses. Also, BP Exploration must meet proposed mitigation, monitoring, and reporting guidelines.

If a marine mammal authorization is approved, the survey is expected to take place between about July 1 and Oct. 20, 1997, during the open water season in and near the Northstar Unit.

The Beaufort/Chukchi Seas support a diverse assembly of marine mammals, including bowhead whales, gray whales, belukha whales, ringed seals, spotted seals, and bearded seals.

It is possible the harvest of some marine mammals (mainly bowhead whales, ringed seals, and bearded seals) by native hunters from coastal North Slope communities may be affected. Migrating marine mammals (principally bowhead whales) may move farther offshore due to possible behavioral changes from elevated noise levels, and this could potentially make the subsistence harvest of this species more difficult.

Deep seismic surveys collect data about oil-bearing rock formations several thousands of meters deep. Sound waves are transmitted into the earth, which are reflected off subsurface formations and recorded. A typical marine seismic source is an airgun array that releases compressed air into the water, creating an acoustical energy pulse that is directed into the earth. Hydrophones spaced along the ocean bottom receive the reflected energy from the subsurface formations and transmit the data to the surface vessels. On board, the signals are amplified, digitized, and recorded on magnetic tape.

The airguns emit pulsed energy primarily at frequencies in the 10 to 300 Hz range. Small whale and seal hearing is believed to be poor at frequencies less than 1,000 Hz, and should be relatively unaffected by the survey, although the belukha whale and the seals are likely to detect some sounds at these frequencies. However, bowhead and gray whales have been known to move away from a seismic search area.

As part of the proposed authorization, the fisheries service proposes that BP Exploration observe several operating procedures designed to avoid potential injury to marine mammals. The fisheries service proposes 1) biological observers onboard the seismic vessels monitor marine mammal presence in the vicinity of the seismic array (the array would be powered down if seals or whales are sighted within 850 - 3,300 feet, depending on the species); 2) the airguns be brought to operating levels over a several minute period at the commencement of operations or after any period where the array is powered down; and 3) if marine mammals are observed within a safety zone designated to prevent injury to the animals, start-up operations will be delayed until all marine mammals are outside that distance.

In addition, BP Exploration is developing an agreement with Native American subsistence whalers to reduce any potential interference with their hunt as well as provide information to help resolve uncertainties about the effects of seismic exploration on the accessibility of bowheads to hunters.

Comments will be received through May 22, 1997, and should be addressed to Chief, Marine Mammal Division, Office of Protected Resources, National Marine Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910-3225. Copies of the application and an environmental assessment may be obtained by contacting the above office.