Extreme ocean temperatures threaten to wipe out Caribbean coral

Unusually warm waters in the Caribbean Sea are fueling what some scientists say is the region’s worst episode of coral bleaching ever recorded — yet another worrisome development in what has been an off-the-charts year of warmth for the world’s oceans.

Reefs in and around the Caribbean are experiencing high levels of heat stress, according to researchers at the National Oceanic and Atmospheric Administration, stoking fears that widespread bleaching could lead to a catastrophic die-off of corals in the area. It comes on the heels of one of the worst bleaching events ever seen off Florida.

“Florida is just the tip of the iceberg,” said the coordinator of NOAA’s Coral Reef Watch Program, Derek Manzello, a coral reef ecologist. “The entire Caribbean right now is bleaching. If you picked a random spot on the map in the Caribbean and jumped in the water, you’re going to see bleached corals.”

Warm conditions are expected to linger in the Caribbean Sea in the coming weeks, while the Southern Hemisphere also transitions out of winter and into warmer spring temperatures. All told, it may be the start of what's known as a global bleaching event, Manzello said, which is characterized by widespread coral bleaching in all three ocean basins: the Atlantic, the Pacific and the Indian.