PALM BEACH, Fla., Aug. 30 (UPI) -- A rare series of cold-water upwellings from the deep ocean has severely damaged coral reefs in Florida already stressed by pollution, scientists say.
The blasts of cold water hit the reefs in July, fatally bleaching large areas of coral, already under siege from sewage, fertilizers, pesticides and algae, The Palm Beach (Fla.) Post reported.
Much of the damage hit staghorn coral, an endangered species.
The impact is not just environmental; there an economic cost as well because marinas, boat-sellers, bait shops and fishing and dive charters depend on the health of the reefs.
Thomas Goreau, president of the Global Coral Reef Alliance in Cambridge, Mass., said 70 percent of a patch of staghorn coral off Palm Beach, the area's largest, was dead or dying.
"There are records of cold water bleaching kills, but they all happened in the winter," Goreau said.
Upwellings, upward flows of water, are impossible to predict, Goreau said.
"What is really exceptional about this event is it happened in the hottest time of the year."
The upwellings in July subjected the corals to quickly alternating lethally high and lethally low temperatures, another expert said.
"It would be the equivalent of a human being jumping into the Bering Sea, where hypothermia would kill the individual in minutes to hours," said Rob Ruzicka, a coral researcher with the Florida Fish and Wildlife Conservation Commission. "Exposure to extreme cold water like this would have acute impacts."