1998 Bleaching: NOAA Press Release

astrong at nesdis.noaa.gov astrong at nesdis.noaa.gov
Fri Oct 23 09:44:25 EDT 1998


     Unprecedented coral bleaching and extremely warm waters occurred throughout 
the Tropics during the first half of 1998, the Commerce Department's National 
Oceanic and Atmospheric Administration announced today.

     Coral reefs -- the "rainforests of the sea" – are some of the oldest and 
most biologically diverse ecosystems on earth.   Important assets to local and 
national economies, they produce fisheries for food, materials for new 
medicines, and income from tourism and recreation, as well as protect coastal 
communities from storms.

     "Coral bleaching is a sign that reefs are under severe stress and may be 
seriously damaged," said NOAA Administrator D. James Baker.  "With 1998 named 
the Year of the Ocean, it is appropriate that we focus our attention on these 
extremely important and fragile coral reef ecosystems." 

     Corals thrive as long as temperatures remain at or below certain 
temperatures for a given site. An increase of one or two degrees above the usual 
maximum temperatures can be deadly to these animals.  The temperature range for 
corals to thrive varies from site to site by only a few degrees. While many 
corals normally recover from short bleaching events, long-term or frequent 
bleaching may severely weaken the corals leaving them more vulnerable to 
disease, damage or death. 

     Data from NOAA's satellites show that during the first half of 1998, more 
ocean area in the tropics experienced exceptionally high sea surface 
temperatures, or "hot spots," than observed in any full year since 1982.  
Approximately 50 countries have reported coral bleaching since 1997.   During 
the El Niño of 1982-83, large areas of coral reef around the world were severely 
damaged by high water temperatures associated with coral bleaching.  The 
previous annual record for high ocean temperature events was in 1988, which also 
followed an El Niño event the year before.

     Using satellites to measure sea surface temperatures and identify hot 
spots, NOAA has been able to predict coral reef bleaching events in real time 
over large ocean areas since 1997, reports NOAA oceanographer Al Strong.  Hot 
spots are identified when satellite-derived sea surface temperatures exceed by 
1.0 degree Celsius the monthly average temperature expected during the warm 

     Coral bleaching can be a sign that the coral is being stressed by a number 
of factors, including pollution, sedimentation or changes in salinity. Increases 
in water temperature of one degree or more for one month often result in 
extensive coral bleaching, making these hot spots prime candidates for bleaching 

     From January to July the coral bleaching events were concentrated in the 
Southern Hemisphere during its warm season.  Since July, the reports of 
extensive coral bleaching have spread into regions of the Northern Hemisphere 
following abnormally high sea surface temperatures, especially around the 
Philippines and throughout the Caribbean Basin, Bahamas, Bermuda and Florida 

     With collaborators Ray Hayes of Howard University and Tom Goreau of the 
Coral Reef Alliance, Strong is planning to summarize the year's coral bleaching 
events in the December issue of Reef Encounters.  

     Bleaching and other problems facing coral reefs will be the topic of a 
high-level government meeting in Key Biscayne, Fla., on Oct. 19 and 20.  The 
Coral Reef Task Force was created by an executive order signed June 11 by 
President Clinton as part of the Year of the Ocean observance and the National 
Ocean Conference held in Monterey, Calif., last June.  The first meeting of the 
task force will be hosted by the Commerce and Interior Departments.  


Notes to Editors: Charts accompanying this release are available on the World 
Wide Web at NOAA Public Affairs:  

Videotape animation of hot spots conducive to coral bleaching is available from 
Video Transfer, Rockville, Md. Telephone: 301-881-0270.

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

To subscribe to the Global Coral Reef Monitoring Network, go to:

October 15, 1998

**** <>< ******* <>< ******* <>< ******* <>< ******* <>< ******* <>< *****
Alan E. Strong
  Phys Scientist/Oceanographer                    Adj Assoc Res Professor
  NOAA/NESDIS/ORA/ORAD -- E/RA3                    US Naval Academy
  NOAA Science Center -- RM 711W                    Oceanography Department
  5200 Auth Road                                        Annapolis, MD 21402
  Camp Springs, MD 20746-4304                            410-293-6550
        Alan.E.Strong at noaa.gov
  301-763-8102 x170    FAX: 301-763-8108

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