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Continued Study May Provide Clues on Reef's Resiliency

NOAA image of coral bleaching as seen in the Caribbean.Feb. 10, 2006 The coral reefs of NOAA's Flower Garden Banks National Marine Sanctuary, located off the Texas-Louisiana coast, have begun to recover from what some observers feared would be a deadly coral bleaching event this past fall. Last fall, surveys showed an average between 42 percent and 46 percent of all coral were showing signs of bleaching. A follow-up survey in January showed that between 4 percent and 10 percent of the coral were showing any signs of bleaching. (Click NOAA image for larger view of coral bleaching as seen in the Caribbean. Click here for high resolution version. Please credit “NOAA.”)

"History has shown the Flower Garden Banks to contain resilient coral reefs," said George Schmahl, manager of the NOAA Flower Garden Banks National Marine Sanctuary. "Further research is needed to determine what allows this location to be so resilient. This may help us understand why reefs in other places are not doing as well and how we can help them."

Coral bleaching is associated with a variety of stresses, including increased sea surface temperatures. This causes the coral to expel symbiotic micro-algae living in their tissues—algae that provides corals with nutrients. Losing their algae leaves coral tissues devoid of color, and thus the coral appears to be bleached. Prolonged coral bleaching can lead to coral death and the subsequent loss of coral reef habitats for a range of marine life.

While the Flower Garden Banks survey showed that most corals are recovering from the bleaching episode, it also showed that some coral colonies were displaying symptoms consistent with a class of coral disease known generally as "white plague." Similar patterns of increased disease following bleaching events have been observed throughout the Caribbean.

"It is the cumulative impact of a number of seemingly small injuries that appear to be causing the overall degradation of many coral reefs," said Schmahl. "Think of it as being 'pecked to death by ducks.' As managers, it is our responsibility to reduce the total number of things that are causing stress on corals. Although we can not control coral bleaching, we may be able to control some of the other potential impacts that contribute to the total stress on coral reefs."

Located in the northwestern Gulf of Mexico, the NOAA Flower Garden Banks National Marine Sanctuary, designated in 1992, includes three separate areas: East Flower Garden, West Flower Garden and Stetson Banks, which was added in 1996. The sanctuary harbors the northernmost coral reefs in the continental United States and serve as regional reservoirs of shallow-water reef fishes and invertebrates. The sanctuary has become one of the top diving locations in the world for coral reef viewing.

The NOAA National Marine Sanctuary Program seeks to increase the public awareness of America's marine resources and maritime heritage by conducting scientific research, monitoring, exploration and educational programs. Today, the sanctuary program manages 13 national marine sanctuaries and one coral reef ecosystem reserve that together encompass more than 150,000 square miles of America's ocean and Great Lakes natural and cultural resources.

NOAA, an agency of the U.S. Department of Commerce, is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and providing environmental stewardship of the nation's coastal and marine resources.

Through the emerging Global Earth Observation System of Systems (GEOSS), NOAA is working with its federal partners and nearly 60 countries to develop a global monitoring network that is as integrated as the planet it observes.

Relevant Web Sites
NOAA Flower Garden Banks National Marine Sanctuary

NOAA National Marine Sanctuary Program

NOAA Ocean Service

Media Contact:
Ben Sherman, NOAA Ocean Service, (301) 713-3066 or David Hall, NOAA National Marine Sanctuaries, (301) 713-3125 ext. 248