Coral Reef Bleaching Seminar
Coral Health and Monitoring Program
coral at coral.aoml.erl.gov
Fri Jan 26 12:02:26 EST 1996
U.S. Global Change Research Program Second Monday Seminar Series
CORAL REEF BLEACHING: ECOLOGICAL AND ECONOMIC IMPLICATIONS
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
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
E-Mail: TSOCCI at USGCRP.GOV.
Additional information on the U.S. Global Change Research Program
(USGCRP) and this Seminar Series is available on the USGCRP Home Page
at: http://www.usgcrp.gov. Normally these seminars are held on the
second Monday of each month.
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