If you plunge into the warm, blue waters of the Caribbean today, what you’ll see in most regions is actually quite bleak. Where there were once vibrant coral reefs teeming with sharks, groupers, and lobsters, there are now piles of rubble, carpets of green seaweed, and only the meager remains of a once colorful sea of coral.
Over the last 50 years, more than half of all hard corals — colonies of tiny animals called polyps that grow skeletons and build coral reefs — have disappeared in the Caribbean. The picture is even grimmer nearby in the Florida Keys, where coral has declined by 90 percent. As corals die, seaweed often takes over, which can make it hard for the reef to recover…
The small island of Bonaire, however, tells a different story.
East of Curaçao in the south Caribbean, Bonaire is a volcanic island just half the size of Chicago. And within its waters is a bustling marine metropolis. A large reef circles the island with towering, centuries-old corals, where countless creatures reside, from seahorses and sea turtles to hammerhead sharks and rays.
“Bonaire is what a well-functioning, healthy reef should be,” said Sophie McCoy, a marine ecologist at the University of North Carolina Chapel Hill, who researches mats of algae-like bacteria that colonize these ecosystems. “We’ve been studying Bonaire in my lab as an example of how a reef should be functioning.”
…But there’s another potentially critical reason why coral in Bonaire is so abundant: half a century of fishing restrictions. The island banned spearfishing in 1971 and soon after established one of the world’s first marine parks. The park, or marine protected area (MPA), encircles the entire island and prohibits certain kinds of fishing, anchoring, and other activities that can damage coral. Unlike most MPAs in the Caribbean, which fail to limit commercial activities, this park has successfully restrained fishing…
The virtue of MPAs as a coral conservation strategy is surprisingly controversial. What’s clear is that even the strongest protections, whether they prevent fishing, pollution, or any other local impacts, won’t do much for reefs during an extreme heat wave or storm. Such threats don’t care about park boundaries. That’s why some scientists have railed against MPAs as a coral-saving strategy.
“They can’t keep temperatures out,” John Bruno, a marine ecologist at the University of North Carolina Chapel Hill, told me. “They can’t keep climate out.”