May 5, 2009

Study: Big fish vanishing from Caribbean

The disappearance of sharks, barracuda and other large predators from Caribbean reefs is related to the growing human population, a Florida researcher says.

Chris Stallings, a post-doctoral researcher at the Florida State University Coastal and Marine Laboratory, compared populations of 20 predatory species of fish on the reefs of 22 Caribbean countries. His results were to be published Wednesday in the journal PLoS One.

I found that nations with more people have reefs with far fewer large fish because as the number of people increases, so does demand for seafood, he said. Fishermen typically go after the biggest fish first, but shift to smaller species once the bigger ones become depleted. In some areas with large human populations, my study revealed that only a few small predatory fish remain.

Stallings said the consequences of the decline in large fish are difficult to predict because of the complexity of the food webs on reefs. He said one likely result is the filling of niches by invaders such as the Pacific lionfish, introduced in the Caribbean through aquarium releases.