CONTACT: Patricia Viets, NOAA
An international team of coral reef experts has reported that high sea surface temperatures in 1998 have affected almost all species of corals, leading to unprecedented global coral bleaching and mortality, the Commerce Department's National Oceanic and Atmospheric Administration said today.
Corals live on the upper edge of their temperature tolerance, with high temperatures directly damaging them. This means that the increase by about 2 degrees Celsius predicted by the Intergovernmental Panel on Climate Change for the next 50 years would pose a serious threat. The 1998 bleaching event may have far-reaching negative consequences for human health and economies that depend on biodiversity, fisheries, tourism and shore protection provided by coral reefs.
The group of experts, attending the International Tropical Marine Ecosystems Management Symposium conference in Townsville, Queensville, at Australia's Great Barrier Reef, also reported that associated reef invertebrates have been affected by warmer sea temperatures. Loss of some corals more than 1000 years old indicates the severity of this event.
"Managers and scientists from around the globe are particularly concerned about this past year's unprecedented, global bleaching episode," said D. James Baker, NOAA administrator. "The bleaching and mortality rate may even worsen in the years ahead. This serves as a wake-up call for more research and monitoring to help protect these valuable coral reef ecosystems."
Global coral bleaching and die-off was unprecedented in 1998 in geographic extent, depth, and severity. Although the effects were uneven and patchy, the only major reef region spared from coral bleaching appears to be the Central Pacific. In some parts of the Indian Ocean, mortality is as high as 90 percent.
Reefs in the Maldives, Sri Lanka, Kenya, and Tanzania were devastated, with shallow reefs looking like graveyards. Many reefs in Southeast Asia have been similarly affected. Countries worst hit were Japan, Taiwan, Philippines, Vietnam, Thailand, Singapore, Indonesia and the islands of Palau. This will impact severely on the livelihoods of millions of people.
Current projections of global warming suggest there could be increased frequency of coral bleaching and coral mortality.
The meeting concluded that this is a matter of particular concern for dozens of developing nations, especially tropical small islands, because healthy coral reefs are crucial to their inhabitants' economic and social survival.
Alan Strong, a NOAA oceanographer, has tracked sea surface temperatures and coral reef events worldwide and was part of the team reporting the unprecedented results for 1998. He is working with Australian scientists to develop future research collaboration with NOAA using satellites and buoys more effectively in coral reef studies. Strong said that an international conference is being planned for Hawaii in June 1999 to help assess and stimulate further satellite research of reefs