The project was the first comprehensive assessment of the resiliency of reefs along the entire National Marine Sanctuary that stretches about 300 miles from Martin County to the Dry Tortugas in the Florida Keys. Scientists are trying to determine why some reefs are resilient to environmental changes and impacts. The work may also identify ways to care for reefs worldwide.
At nearly 175 sites, scuba divers recorded the number and species of coral and the extent of bleaching -- corals turn white when tiny algae that live inside them die. Bleaching is a symptom of coral stress, which can be caused by high water temperatures, other environmental stresses, or disease. The project was part of the Florida Reef Resiliency Program, funded by the state of Florida and The Nature Conservancy. It involved volunteers and researchers from several agencies, organizations and universities, including the University of South Florida.
Data from the MODerate-resolution Imaging Spectroradiometer (MODIS) aboard the Terra and Aqua satellites gave accurate, up-to-date information on sea surface temperatures to identify areas vulnerable to bleaching. The data was also used to measure the cumulative heat buildup over several weeks, shown to be particularly important to the health of reefs.
"MODIS imagery is beneficial because it provides more detail than traditional satellites, allowing us to detect conditions down to hundreds of meters - the size of individual reefs," said Christopher Moses, University of South Florida, Tampa, Fla.
Researchers also used the recently developed Landsat-based Millennium Coral Reef Map http://seawifs.gsfc.nasa.gov/cgi/landsat.pl to determine which reef areas were most appropriate for sampling. Funded by NASA and
Source:NASA/Goddard Space Flight Center