NOAA 2003-R122
Contact: Connie Barclay
NOAA News Releases 2003
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Studies Might Harass Small Numbers of Marine Mammals

NOAA’s National Marine Fisheries Service (NOAA Fisheries) is seeking comments on two proposals by the Lamont Doherty Earth Observatory (Observatory) of Columbia University to take small numbers of marine mammals, by harassment, incidental to conducting studies in the Gulf of Mexico and in waters of the Equatorial Pacific Ocean. The National Oceanic and Atmospheric Administration (NOAA) is an agency of the Commerce Department.

The Observatory wants to conduct calibration studies of its seismic airguns in the Gulf of Mexico. In addition, they plan to conduct oceanographic surveys in international waters of the Pacific Ocean to obtain scientific information on the geologic nature of the boundaries of the earth's crust at the spreading ridges of tectonic plates.

In the Pacific Ocean, the R/V Maurice Ewing will deploy an array of airguns as an energy source, plus a 6-km (3.2 nm) towed streamer containing hydrophones to receive the returning acoustic signals. In the Gulf of Mexico, the Observatory plans to measure sound levels from the airgun arrays that will be used during its seismic survey programs in the future. These measurements will be made in shallow, shelf slope, and deep waters either in late May or June 2003, but may be rescheduled for later in the year.

The researchers would like to develop specific knowledge about how sound levels change and radiate in varying topography and at different depths, in order to contribute scientific evidence on the extent that noise generated by the seismic sound sources has the potential to disturb the behavior of marine mammals in the vicinity of the ship. Therefore, Incidental Harassment Authorizations under the Marine Mammal Protection Act may be warranted.

The scientists expect the measurements to be used to verify estimates of sound fields around the airgun arrays that have been made using acoustical models. Verification of the output from these models is needed to confirm the distances from the airguns where mitigation may be necessary to avoid exposing marine mammals to airgun sounds at certain levels. The measurements will also verify the distances where the sounds diminish below levels that could bother the mammals.

While the number of potential takes by incidental harassment will depend on the distribution and abundance of marine mammals in the vicinity of seismic operations, NOAA Fisheries believes the number of potential takes by harassment would be small, and would not have more than a negligible impact on affected marine mammal stocks. No take by injury or death is anticipated, and the potential for temporary or permanent hearing impairment would be avoided through the incorporation of mitigation measures, such as ramping up airguns over several minutes to allow marine mammals to move away from the noise, and ensuring no marine mammals are within established safety zones through monitoring by trained biologists.

NOAA’s National Marine Fisheries Service (NOAA Fisheries) is dedicated to protecting and preserving our nation’s living marine resources through scientific research, management, enforcement, and the conservation of marine mammals and other protected marine species and their habitat.

NOAA Fisheries will accept comments on the application through May 14, 2003. Comments should be addressed to the Chief, Marine Mammal Division, Office of Protected Resources, NOAA Fisheries, 1315 East-West Highway, Silver Spring, MD 20910. A copy of the application and Federal Register notice may be obtained by contacting the same office at (301) 713-2055.

The Commerce Department’s National Oceanic and Atmospheric Administration (NOAA) is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and providing environmental stewardship of our nation’s coastal and marine resources.

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