Some Sharks, Barracuda Completely Gone in Caribbean

The big fish of the Caribbean (above, a juvenile yellowfin grouper) are disappearing due to unchecked overfishing, though programs to work with small-scale fishers are underway, experts say.Photograph by Emma Hickerson/Flower Garden Bank National Marine Sanctuary

The big fish that prowl the Caribbean reefs—gaping groupers, sharp-toothed barracuda, and gigantic sharks—are completely gone in some places due to overfishing, a new study says.

The problem is worst in the most densely populated Caribbean countries, where fishers have wiped entire reefs clean of large predators.


In such places, smaller predators have begun to fill in niches left by the big hunters—sending coral reefs into a tailspin.

The new research, based on a public database of fish sightings by trained volunteer scuba divers, provides one of the most comprehensive glimpses so far of the decline in large Caribbean predators.

"Healthy and intact coral reefs need large predatory fish in order to continue to provide human societies with food and with beauty," said study author Chris Stallings, a researcher at Florida State University's Coastal and Marine Laboratory.

Phillip Kramer, director of the Caribbean program for the nonprofit group the Nature Conservancy, agreed that "you can't take the large carnivores out of the system.

"It's like the deer in Yellowstone without the wolves—you'll have cascading impacts," said Kramer, who was not involved in the research.

Off Balance

Stallings studied more than 38,000 surveys over a 15-year period in the Reef Environmental Education Foundation's online database, which Stallings said is a reliable source for fish sightings.

He examined 20 predator species of varying sizes and their abundance across the region.

The findings, in the journal PLoS ONE, revealed that some species of large groupers, snappers, and sharks—such as bull sharks, tiger sharks, and blue sharks—are now gone near densely populated areas. This includes reefs in the Greater and Lesser Antilles and Jamaica.

The Nassau grouper, once abundant throughout the Caribbean, has been so heavily fished it is listed as endangered by the International Union for Conservation of Nature.

With the giants out of the picture, other fish have moved in, including the relatively unfished trumpet fish, the two smallest grouper species, graysby and coney; and two small snapper species, lane and mahogany.

The increase in smaller predators may lead to unanticipated changes in the ecosystem, Stallings said, and may even open the door to invasive creatures.

For example, the Pacific lionfish, a recent arrival to the Caribbean due to aquarium releases, has blossomed in the absence of big hunters.

Tough Situation

Most Caribbean countries do not have strong fisheries management programs that emphasize conserving big fish, Stallings said.

He also noted that the region's fishers, who are mostly small-scale, face a day-to-day demand to catch enough to feed their families and to sell enough to make a living, he said.

To show—rather than tell—Caribbean fishers about the importance of sustainable fishing, the Nature Conservancy has begun a fisher-exchange program, the conservancy's Kramer said.

As part of this program, Jamaican fishers recently traveled to Belize to see that country's well-preserved and predator-rich reefs.

"It's amazing what that does to a fisherman's perspective," Kramer said.

"You have to be working at the community level to instill change."