1997: Year of the Reef/Planeta.com

1997: Year of the Reef

August 1996

Next year, 1997, is designated as the "International Year of the Reef" (IYOR). It is a major effort to assess the condition of coral reefs worldwide. It seeks to document patterns of degradation and their causes, as well as educate the public about the value of reefs. It also aims to advance their recovery and promote their sustainable management. It hopes to be complementary to other reef programs and activities.

On one hand, IYOR will undertake coral reef assessment, monitoring, and other relevant research in order to gain a more complete picture of the reefs of this world and how to keep them alive. On the other hand, it will work through a "Public Awareness Committee" to publicize the value of coral reefs and they serious threats we humans are making to them. Various conservation and government organizations and scientists will take the lead.

IYOR is still in the planning stages and will be launched at the 8th International Coral Reef Symposium in Panama in June of this year. If you are interested in participating, contact Stephen Colwell, Executive Director, Coral Reef Alliance, 809 Delaware Street, Berkeley, CA 94710, U.S.A., Tel. (510) 528-2492. Fax (510) 528-9317. E-mail: .

The U.S. Global Change Research Program Seminar Series presented "Coral reef bleaching: ecological and economic implications" as its February program. The public is always invited to this monthly series, held in the Rayburn House Office Bldg., Room B369. For further information, see below. Speakers this month were Dr. Raymond L. Hayes, Howard University, Washington, D.C. and Dr. Alan E. Strong, National Environmental Satellite, Data, and Information Service (NESDIS), National Oceanic and Atmospheric Administration,Annapolis, Md.

Overview

Coral reef bleaching is a reduction in the density of marine microscopic plants (dinoflagellate algae) that are housed in reef ecosystems. Bleaching also represents a reduction in algal pigments, rendering reef corals bleached or white in appearance. Consequently, coral reef bleaching represents an uncoupling of the mutually life-sustaining association between algae and coral. Corals do not receive their normal nutritive support from the algae, and the algae do not receive the protective nutritive environment afforded by the corals.

Coral reef bleaching was first observed in the early 1980's. Since that time reef ecosystems in all tropical regions of the globe have experienced repetitive and more frequent episodes of mass coral reef bleaching. Although elevated salinity, toxic chemicals, elevated UV radiation, reduced temperatures, and prolonged shading due to cloud cover have been demonstrated to induce coral reef bleaching locally, there is no evidence of these factors being responsible for mass coral reef bleaching episodes.

Observations also indicate that mass coral reef bleaching has coincided in space and time with the warmest season and with warmer than usual sea surface temperatures. Thermal anomalies are significantly correlated with the rapid onset and duration of mass coral reef bleaching episodes. As elevated sea surface temperatures gradually fall, reefs may either recover gradually or succumb entirely to the stress. If bleaching persists, there is no net reef building and the reef frame gradually erodes, which can result in habitat destruction and mortality.

Satellite data confirm that elevated sea surface temperatures have been associated with widespread coral reef bleaching in the western Caribbean and in the Gulf of Mexico. An analysis of the satellite-derived sea surface temperatures show that the summer of 1995 was the warmest since 1984 (when reliable records were first obtained) for Belizian Reefs and for the entire Caribbean Basin. Belize represents the Western Hemisphere's longest and most pristine barrier reef, and massive coral reef bleaching broke out for the first time in Belize in September, 1995.

Prolonged coral reef bleaching can alter the relative abundance of reef organisms and, in so doing, alter the biodiversity of the reef communities. The physical reef structures can also suffer gradual physical losses and/or be covered by algae, thus leading to light and oxygen starvation, and changes in pH (alkalinity-acidity) in the surrounding water column. As reef ecosystems change in composition, a new community equilibrium may appear, while some medically important members of former reef communities may disappear. Loss of physical reef habitat for young fish may also lead to a reduction in reef fish and, in turn, a decline in economically important open ocean fishstocks.

For more information please contact: Dr. Anthony D. Socci, U.S. Global Change Research Program Office, 300 D St., SW, Suite 840, Washington, DC 20024. Telephone: (202) 651-8244; Fax: (202) 554-6715. E-Mail: . Normally these seminars are held on the second Monday of each month.