Whats causing coral bleaching?
Oceanographic studies over the past several years, corroborated by the National Oceanic and Atmospheric Administration, showed that high sea-surface temperatures were to blame for unprecedented coral reef bleaching throughout the Indian Ocean and the Pacific. Reef scientists knew that temperature change could stress the corals and cause expulsion of zooxanthellae, their symbiotic algae (see Geotimes, April 1998) or loss of symbiotic algal pigments. But recent research has shown that other factors, including zooxanthellae density and pathogens, also may be at work. Effects of temperature Bleaching was first reported in the 1980s in Puerto Rico, Jamaica, southern Florida, and other Caribbean areas. As researchers began to collect data on the bleaching, they found that Caribbean water temperature had increased by nearly 2 degrees Celsius between 1986 and 1987. Episodes of bleaching, linked to temperature increases, continued to occur during the next 10 years. In some cases, it seemed as t
