Oct. 25, 2006 – Global coral health has rapidly declined in the last half-century due to pollution and global warming, researchers at the Coral Reef Task Force symposium in St. Thomas said this week.
Some 200 scientists met at the Marriot Frenchman's Reef this week, where reports on global coral health included in-depth reports on V.I. coral.
"The U.S. Virgin Islands are one of the most beautiful places in the world, and it's hard to believe sometimes that there are problems here under the sea," said Caroline Rogers, a U.S. Geological Survey scientist who studies coral around St. John.
Pollution (such as from boat paints and sewage), overfishing, runoff from land-based construction, and global warming have decimated coral, pushing the vital undersea life toward mass die-offs. Last summer, record amounts of coral bleached and later died in the Virgin Islands during nearly six months of abnormally warm seas, the scientists said.
Some 60 percent of the world's coral reefs could die in less than 25 years under these increasing stresses, said UVI researcher Tyler Smith.
Up to 30 percent of the world's coral reefs have died in the last 50 years, and another 30 percent are severely damaged, Smith said, quoting a 2004 study by Australian government researchers.
"U.S. Virgin Islands coral today is likely at its lowest levels in recorded history," he said.
Nearly half of the coral at 31 acres of underwater study sites around the Virgin Islands died after abnormally warm seas in 2005, said Jeff Miller, a scientist with the V.I. National Park. "Forty-seven percent in a year. That's amazing. It's catastrophic," Miller said.
A record 9 percent of reef-building elk horn coral also died in the sample areas.
The coral reefs, which are vital habitat for countless marine plants and animals, were more susceptible to disease and premature death when seas topped normal temperatures for nearly three months last year.
"Disease doubled after the bleaching event," Smith said.
Stressed by the high sea temperatures, the coral also battled an increase in algae, which competes with coral for sunlight.
Nutrient-rich sewage may be to blame for some of the algae, Rogers said, as well as overfishing of algae-eating parrot fish.
Silt runoff from construction sites also block access to sun for coral, which are "basically solar-powered animals," Rogers said.
Government and private scientists from the Caribbean, Florida, and the U.S. Pacific territories shared ideas and concerns about coral health and the best ways to hold back the damage, which depends largely on changing man's behavior.
Rogers pleaded for better study of water dispelled by cruise ships.
"We don't know what's coming out of these things, and we should find out," she said. "Sewage is a pollution that hasn't been very well studied."
Historically — before overfishing, increased pollution and warmer-than-normal sea temperatures — coral recovered quickly from hurricanes and other damage, Smith said.
Since 2002, however, disease in reef-building elk horn coral increased 88 percent, and elk horn death is up 25 percent in the Virgin Islands, Smith said.
"Down the road, our grandchildren will lament the fact that we lost the resources that we had a chance to save," Smith said.
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