d.fenner at aims.gov.au
Thu Jul 2 18:27:01 EDT 1998
CONTACT: Patricia Viets, NOAA FOR IMMEDIATE RELEASE
(301) 457-5005 xxxxxxx
1998 Coral Reef Bleaching in Indian Ocean Unprecedented,
An episode of extremely high ocean temperatures migrated from south
north throughout the Indian Ocean during the first six months of 1998
causing considerable coral reef bleaching in its wake, the National
and Atmospheric Administration reports.
Sea surface temperatures, exceeding the maximum values expected for
any time during the year, were observed by NOAA's satellites to have
exceeded levels critical to cause beaching where these waters overlay
Indian Ocean coral reefs.
A somewhat similar episode occurred following the 1987 El Nino in
Indian Ocean; however, in 1988 the extreme sea surface temperature
anomalies, toxic to corals, moderated sufficiently as the sun moved
the Northern Hemisphere. In that year, reefs in the Indian Ocean
the equator were spared heavy bleaching.
In 1998, this has not been the case. Bleaching, earlier projected
NOAA, has been reported from the field on the following reefs:
Kenya; Reunion; Mauritius; Somalia; Madagascar; Maldives; Indonesia;
Lanka; Gulf of Thailand [Siam]; Andaman Islands; Malaysia; Oman;
This unprecedented round of bleaching in coral reefs throughout the
Indian Ocean follows El Nino-related bleaching events during late-1997
early-1998 both projected by NOAA's satellite HotSpot charts and
by reef scientists in Mexico (Pacific), Panama (Pacific); Galapagos;
Australia's Great Barrier Reef; Papua New Guinea; and American Samoa.
In the Indian Ocean, sea surface temperature anomalies appear to be
coming less severe toward the end of June. The total area covered by
"HotSpots" is now only in the northernmost fringes of the Indian
However, during June the Philippines and the Florida Keys regions have
seeing temperature anomalies sufficiently high that bleaching has been
reported and biologists are concerned for reefs there.
Coral reefs -- the "rainforests of the oceans" -- support a variety
sea life and provide resources of significant economic importance such
fishing and recreation. Coral bleaching, induced by high water
temperatures, has raised concerns about these fragile ecosystems.
bleaching occurs as coral tissue expels zooxanthellae, a type of algae
resides in the structure of the coral, and is essential to the coral's
survival. Corals normally recover, unless high ocean temperatures
for too long a period or become too warm.
Coral Reef "HotSpots" depicted as regions of yellow/orange in the
those anomalies that are equal to or above the annual maximum sea
temperatures by +1 deg C or more.
HotSpot animations are available at the Oceanic Research &
Applications Division's WebSite:
(please send any replies to addresses found in these web sites, not the
forwarder of this message, as I have no further information on this.)
Douglas Fenner, Ph.D.
Australian Institute of Marine Science
PMB No 3
phone 07 4753 4241
e-mail: d.fenner at aims.gov.au
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