CHAPEL HILL -- Coral disease outbreaks hit hardest in the healthiest sections of the Great Barrier Reef, where close living quarters among coral may make it easy for infection to spread, University of North Carolina at Chapel Hill researchers have found.
Despite a link to warmer ocean temperatures, coral disease defies predictability, with puzzling variations between years and locations. The international research team, led by UNC-Chapel Hill, tracked an infection called white syndrome in 48 reefs along more than 900 miles (1,500 kilometers) of Australias coastline for six years. While higher temperatures drove the disease outbreaks, the team also discovered a strong connection between white syndrome and coral cover, a measure of reef health. The highest-cover reefs, which had living coral covering more than 50 percent of the ocean floor, had major outbreaks after warm years. Disease was usually absent on low-cover reefs.
Understanding the causes of disease outbreaks will help ecologists protect reef-building corals, which support commercial marine species and buffer low-lying coastal areas. "More diseases are infecting more coral species every year, leading to the global loss of reef-building corals and the decline of other important species dependent on reefs," said lead study author John Bruno, Ph.D., assistant professor of marine ecology and conservation in UNCs College of Arts and Sciences. "Weve long suspected climate change is driving disease outbreaks. Our results suggest that warmer temperatures are increasing the severity of disease in the ocean," Bruno said.
The results were published May 8, 2007, in the online journal PLoS Biology. The study is one of the largest and longest surveys of ocean temperature and coral disease and is the first to conclusively demonstrate a link between disease severity and ocean temperature, Bruno said.
The colorful coral colonies that attract visitors to the Great Barrier Reef li
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Contact: Becky Oskin
becky_oskin@unc.edu
919-962-8596
University of North Carolina at Chapel Hill
7-May-2007