US: Florida reef showing signs of coral bleaching

KEVIN WADLOW Keys Info Net 13 Aug 14;

A warm winter and hot summer have pushed water temperatures at the Florida Keys reef to a point where coral bleaching may occur.

"The Florida Keys reefs are under a bleaching warning, which means thermal stress continues to accumulate and coral bleaching is possible," said a Tuesday report from Mote Marine Laboratory's Florida Keys Coral Bleaching Early Warning Network.

A state coral researcher reported Monday that water temperatures on shallower patch reefs in the Lower Keys "were in the high 80s, even touching 90 degrees at some spots."

Smaller corals "are paling or beginning to partially bleach," biologist Ron Ruzucka wrote. "However, larger boulder and brain corals on nearshore or patch reefs have started to turn."

"Certainly if conditions remain like they are, it could be a very stressful August and September for the corals," he wrote.

Divers and scientists noted that water temperatures dropped slightly Saturday when the Gulf Stream moved closer to shore.

Coral bleaching -- when extreme temperatures cause corals to expel the algae that give corals their color -- is a natural summer event, but frequent or extended bleaching can damage or kill corals.

Volunteer divers in the Keys can report incidents of bleaching at www.mote.org/bleachwatch.