At its conference in South Korea, the International Union for Conservation of Nature released a report this month indicating that live coral coverage on reefs in the Caribbean has plummeted to less than 10 percent, from nearly 50 percent in the 1970s. Yet describing the entire Caribbean as a region where reefs are in a state of general collapse tends to cloud the problem’s complexity, the study suggests.
The acidification of the ocean has contributed to the bleaching and diminution of coral off Caye Caulker, Belize.
Michael Lesser, a program director for biological oceanography at the National Science Foundation, acknowledges that the region is the “poster child” for the global destruction of reefs.
“The pronouncement that the Caribbean itself would be in dire straits is no surprise,” he said. “We’ve been talking about this for a long time now.”
Overfishing has left its mark, as has the decline of species like the parrotfish and the spiny black urchin known as Diadema antillarum, which graze on algae and ideally keep it from stifling the reefs. Ocean warming and acidification add more pressure, bleaching and weakening coral networks.
“It’s a sort of double whammy,” Lesser said.
But the conservation group’s report shows that the destruction is not spread uniformly. Spots like the Cayman Islands have up to three times more live cover than afflicted reefs in Jamaica and in the U.S. Virgin Islands, which also have noticeably smaller fish and an abundance of algae. There is also uncertainty about what causes coral decline in certain places, pointing up the need for varying strategies across the Caribbean instead of a one-size-fits-all approach.
Jamaica, for instance, struggles economically and is highly dependent on its marine resources, so overfishing is a primary concern there. Enforcing species protection and establishing minimum size limits for catch would therefore be a crucial strategy there, Lesser said.
As for a time scale for recovery, “we’re talking decades,” Lesser said.
Yet hope persists because coral reefs have bounced back in the past. Australia’s Great Barrier Reef is one notable example.