In an experiment with three species of Hawaiian corals researchers found that, when bleached, the branching coral Montipora capitata sharply increased its intake of tiny plankton, making it much more likely to bounce back. The findings suggest that any coral, regardless of shape or location, may recover from bleaching if it can ramp up feeding.
James Palardy, a Brown University graduate student and co-author of the Nature paper, said the results indicate that these corals may become the dominant species in reefs and could play a role in protecting these critical marine ecosystems.
"These 'super-feeders' have an ecological advantage, one that may protect reefs from extinction," Palardy said. "If our results hold up with other species, we may well see that these resilient corals are the future for our reefs."
Coral reefs reduce beach erosion, support tourism and serve as breeding grounds and habitat for fish. A 2006 report by the United Nations Environment Programme put the value of coral reefs at $100,000 to $600,000 per square kilometer per year.
But the UNEP report states that 30 percent of the world's coral reefs are severely damaged or dead and that 60 percent of remaining reefs will vanish by 2030. Several factors are to blame, from pollution to overfishing. Scientists say the biggest new threat is global warming. Because corals are highly sensitive to temperature, even small amounts of warming can trigger bleaching.
When water temperatures rise, coral expel single-celled algae called zooxanthellae, which live inside coral tissue and give corals their color and, more importantly, supply the bulk of their food energy. If bleaching pers
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Contact: Wendy Lawton
Wendy_Lawton@brown.edu
401-863-1862
Brown University
26-Apr-2006