Some Sharks, Barracuda Completely Gone in Caribbean

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.

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.

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.

(From news.nationalgeographic.com)