Coral Reef Bleaching Seminar

Coral Health and Monitoring Program coral at
Fri Jan 26 12:02:26 EST 1996

  U.S. Global Change Research Program Second Monday Seminar Series 


What is coral reef bleaching?  What are its causes?  Where is it 
occurring and how long has this phenomenon been observed?  When was 
coral reef bleaching first observed?  What are the economic, 
ecological, and societal implications of coral reef bleaching?  Can 
bleaching be remedied?  What's being done?  


                                     TUESDAY, February 13, 1996, 
					3:15-4:45 P= M 
                                     Rayburn House Office Bldg., Room B369 
                                     Reception Following 


Rafe Pomerance, Deputy Assistant Secretary for Environment and 
Development, US Department of State, Washington, DC.  


Dr. Raymond L. Hayes, Howard University, Washington, DC.  

Dr. Alan E. Strong, National Environmental Satellite, Data, and 
Information Service (NESDIS), National Oceanic and Atmospheric 
Administration, Annapolis, MD.  


Coral reef bleaching is a reduction in the density of dinoflagellate 
algae (marine microscopic plants) that are housed in reef ecosystems.  
Bleaching also represents a reduction in algal pigments, rendering 
reef corals bleached or white in appearance.  Consequently, coral 
reef bleaching represents an uncoupling of the mutually 
life-sustaining association between algae and coral.  Corals do not 
receive their normal nutritive support from the algae, and the algae 
do not receive the protective nutritive environment afforded by the 

Coral reef bleaching was first observed in the early 1980's.  Since 
that time reef ecosystems in all tropical regions of the globe have 
experienced repetitive and more frequent episodes of mass coral reef 
bleaching. Although elevated salinity, toxic chemicals, elevated UV 
radiation, reduced temperatures, and prolonged shading due to cloud 
cover have been demonstrated to induce coral reef bleaching locally, 
there is no evidence of these factors being responsible for mass 
coral reef bleaching episodes. Observations also indicate that mass 
coral reef bleaching has coincided in space and time with the warmest 
season and with warmer than usual sea surface temperatures (generally 
in excess of an approximate temperature threshold of 30=9A C).  
Thermal anomalies of 1=9A C or more above the maximu= m warm water 
seasonal averages are significantly correlated with the rapid onset 
and duration of mass coral reef bleaching episodes.  As elevated sea 
surface temperatures gradually fall, reefs may either recover 
gradually or succumb entirely to the stress.  If bleaching persists, 
there is no net reef building and the reef frame gradually erodes, 
which can result in habitat destruction and mortality.  

Satellite data confirm that elevated sea surface temperatures have 
been associated with widespread coral reef bleaching in the western 
Caribbean and in the Gulf of Mexico.  An analysis of the 
satellite-derived sea surface temperatures show that the summer of 
1995 was the warmest since 1984 (when reliable records were first 
obtained) for Belizian Reefs and for the entire Caribbean Basin. 
Belize represents the Western Hemisphere's longest and most pristine 
barrier reef, and massive coral reef bleaching broke out for the 
first time in Belize in September, 1995.  

Prolonged coral reef bleaching can alter the relative abundance of 
reef organisms and, in so doing, alter the biodiversity of the reef 
communities. The physical reef structures can also suffer gradual 
physical losses and/or be covered by algae, thus leading to light and 
oxygen starvation, and changes in pH in the surrounding water column.  
As reef ecosystems change in composition, a new community equilibrium 
may appear, while some medically important members of former reef 
communities may disappear.  Loss of physical reef habitat for young 
fish may also lead to a reduction in reef fish and, in turn, a 
decline in economically important open ocean fish stocks.  

                                   Biography of Dr. Raymond L. Hayes 

Dr. Raymond L. Hayes is currently Assistant Dean for Medical 
Education, and Professor of Anatomy, at Howard University in 
Washington, DC.  Dr. Hayes formerly served as Chair in the Department 
of Anatomy at Howard University and at the University of Pittsburgh.  
He has also held academic appointments in the Department of Anatomy 
at Harvard Medical School, the Department of Anatomy and Cell Biology 
at the University of Pittsburgh, and in the Department of Anatomy at 
Morehouse School of Medicine in Atlanta, Georgia.  His research 
interests include the biology of coral reefs and reef ecosystems, 
reef ecosystems and climate change, and human health and climate 
change.  Dr. Hayes has served as a member of the National Advisory 
Council of the National Institute of Environmental Health Sciences, 
and as Acting Director of the MacLean Marine Science Center at the 
University of the Virgin Islands in St. Thomas, and currently serves 
as a Corporation Member of the Marine Biological Laboratory, Woods 
Hole, MA.  He also serves as Vice President and Executive Board 
Member of the Association of Marine Laboratories of the Caribbean, 
and as a member of the Board of Directors for the Marine 
Archeological and Historical Society in Washington, DC.  In 1994 Dr. 
Hayes received the Distinguished Service Award from Howard 
University.  He received his BS degree from Amherst College, MA, and 
his MS and Ph.D. degrees from the University of Michigan at Ann 

                                   Biography of Dr. Alan E. Strong 

Dr. Alan E. Strong has been Research Physical Scientist at the 
National Oceanic and Atmospheric Administration's Environmental 
Satellite, Data, and Information Service (NESDIS) since 1991.  Prior 
to that he served at NESDIS's Office of Research and Applications 
Oceanic Sciences Branch, using satellite data to address 
oceanographic problems.  In 1986 Dr. Strong was assigned to serve as 
Chair of Remote Sensing in the Oceanography Department of the US 
Naval Academy in Annapolis, MD.  In 1991 Dr. Strong was also 
appointed Project Manager of NOAA's Cooperative Project in Oceanic 
Remote Sensing (CPORS) with the US Naval Academy.  His research 
interests include: satellite monitoring of sea surface temperature, 
wind speed, and ocean color; monitoring volcanic aerosols; using 
satellite data to investigate coral bleaching and sea surface 
temperature changes; monitoring sea surface temperature trends; using 
satellite data to study global change and El Nino phenomena; and the 
application of satellite data to study other important environmental 
issues.  For the past three years he has also been involved in 
teaching global climate change at the US Naval Academy.  Dr. Strong 
received his BA degree in mathematics at Kalamazoo College, MI, and 
his MS and Ph.D. degrees in Oceanography at the University of 

                                 NEXT SEMINAR: Monday, March 11,1996 

    Extent & Implications of Land Cover Changes: The View from Space 

for more information please contact: 

Dr. Anthony D. Socci, U.S. Global Change Research Program Office 
300 D St., SW, Suite 840, Washington, DC 20024 
Telephone: (202) 651-8244; Fax: (202) 554-6715 

Additional information on the U.S. Global Change Research Program 
(USGCRP) and this Seminar Series is available on the USGCRP Home Page 
at:  Normally these seminars are held on the 
second Monday of each month.  

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