Cuban scientists hunt for clues to save coral reefs as ocean temperatures soar

Scientists in Cuba hunt for clues that could help researchers across the globe protect reefs in the face of warming waters, over-fishing, pollution and other threats.

Cuban marine biologist Ariandy Gonzalez emerges uneasy from the sun-speckled Caribbean sea off a remote stretch of Cuba's south coast. Something is not right.

The sea floor, once a mosaic of colourful corals, is now marred by patchy white splotches. That is evidence of heat-related coral bleaching, where stressed corals expel their colorful algae symbionts, leaving them pale and vulnerable.

"I think this is the worst bleaching we've seen yet," Gonzalez told five fellow scientists, hoisting himself into a small diveboat that heaved in churning seas.

Gonzalez is among 18 scientists and crew members who for nearly two months have circumnavigated Cuba in the M/V Oceans for Youth ship to hunt for clues that could help researchers across the globe protect reefs in the face of warming waters, over-fishing, pollution and other threats.

The ongoing "Bojeo a Cuba" study is a snapshot in time of the health of Cuba's reef, fish and sea life, the first of its kind across such a large area of the island's waters, said Dr. Fabian Pina, a Cuban marine biologist and expedition co-leader who initiated the project nearly two years ago.

The project has received funding from the Cuban government and international partners, Pina said.

Preliminary observations - the voyage is still about a week from completion - suggest both good and bad news, the scientists told Reuters in interviews at sea.