2 NOAA announced today
that 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.
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
Maps showing twice-weekly distributions
of hot spots are available at:
Movie/animations are posted at:
Maps showing the annual distribution
of bleaching from 1969 through 1997 are posted at: http://www.fas.harvard.edu/~goreau