CONTACT:  Patricia Viets           FOR IMMEDIATE RELEASE
          Stephanie Kenitzer       2/25/98
          

El Nino-related drought and high ocean temperatures in the Pacific Ocean off Australia have resulted in coral reef bleaching around the Great Barrier Reef, raising concern among experts about the future of these fragile ecosystems known as the "rainforests of the sea," the Commerce Department's National Oceanic and Atmospheric Administration announced.

Corals normally recover from bleaching, unless high ocean temperatures persist for too long a period or become even warmer. Coral reefs support a variety of marine life and provide resources of significant economic importance such as fishing and recreation. Coral bleaching, induced by high water temperatures, has raised concerns about these fragile ecosystems. Coral bleaching occurs as coral tissue expels zooxanthellae, a type of algae that resides in the structure of the coral and is essential to the coral's survival.

The bleaching was observed on many inshore reefs of central Great Barrier Reef, particularly reefs off Townsville, after temperatures in the water reached 29 - 30 degrees Celsius (84 - 86 degrees Fahrenheit). Corals there usually thrive in temperatures no higher than 28 degrees C (82 degrees F). These "hot spots," with temperatures well above last year's levels, have been identified by NOAA satellite data and confirmed by data provided by the Australian Institute of Marine Science.

"Sea surface temperatures have warmed considerably off the eastern coast of Australia during the past few weeks," said NOAA oceanographer Al Strong. "Our research indicates bleaching most likely began in the southernmost region of the Great Barrier Reef and appears to be moving toward the north. From our latest observations, these bleaching conditions appear to have reached New Caledonia (at 21 South Latitude,165 East Longitude). Sea surface temperatures from the 1982/83 and 1987 El Ni¤o events were not quite this warm."

NOAA also reports continued warm waters from El Nino and coral reef bleaching off the Galapagos Islands off the coast of Ecuador. Sea surface temperatures there are about 30 degrees C (86 degrees F). This is nearly two degrees warmer than the waters that promoted initial bleaching there in mid-December.

Corals at the Galapagos thrive as long as temperatures remain at or below 27 degrees C -- the normal maximum sea surface temperature at this site. An increase of one or two degrees above the usual maximum temperatures can be deadly to these animals. The temperature range for corals to thrive varies from site to site by only a few degrees.

During the 1997-98 El Nino, NOAA has confirmed coral bleaching in the Western Hemisphere at sites in the Florida Keys, Baja California, Pacific coast of Panama, the Yucatan coast, Caymans, and the Netherland Antilles. In the Eastern Hemisphere, reefs in the Red Sea and the Seychelles have experienced some bleaching during the past year.

"During this Year of the Ocean, it is important that we learn all we can about these extremely important ecosystems," Strong said. "Our interactive Internet site is proving to be a remarkable asset to both the researcher and the reef manager."

Notes to Editors: Videotape animation of hot spots conducive to coral bleaching is available from Video Transfer, Rockville, Md., telephone 301-881-0270.

Video animations of coral reef Hot Spots and sea surface temperatures are available on the World Wide Web at: http://manati.wwb.noaa.gov/orad Click onto "Experimental Products." From there, click onto "Coral Bleaching Hotspots."

For a still image of the area of coral bleaching off Australia, go to: http://manati.wwb.noaa.gov/orad and click on "What's New."