Researchers at UC San Diego’s Scripps Institution of Oceanography published a study Monday documenting successful species conservation and recovery efforts for the Nassau grouper near the Cayman Islands.
Overfishing in the Carribbean in recent decades has led to a collapse of the Nassau grouper stock and, in 2003, prompted the Cayman Islands government to pass and enforce fishing management policies to keep the species from disappearing from the region entirely.
An aggregation of roughly 7,000 Nassau grouper was discovered in the Cayman Islands in 2001 and subsequently overfished, according to Scripps. Monday, few aggregations of Nassau grouper in the region contain more than 1,000 fish.
The International Union for Conservation of Nature currently lists the Nassau grouper as critically endangered.
“Normally, Nassau grouper are relatively solitary, and tend to be hard to catch,” said Lynn Waterhouse, a research biologist at Chicago’s John G. Shedd Aquarium and former Scripps Oceanography student. “But at spawning, they come together en masse to form annual spawning aggregations, where historically tens of thousands of fish come together to reproduce, so they’re very easy for fishermen to catch.”
Scripps Institution researchers jointly published their study in the journal Proceedings of the National Academy of Sciences with researchers and scientists from Oregon State University, the Grouper Moon Project, the Cayman Islands Department of Environment and the citizen conservation group Reef Environmental Education Foundation.
The study used tagging and video data to monitor the species’ wild population and measure the success of season fishing closures, which allow overfished species to recover. The study team tracked the region’s Nassau grouper population for more than 15 years and saw the species’ aggregation near Little Cayman increase nearly six-fold, from roughly 1,200 in 2009 to more than 7,000 fish in 2018, due in large part to a spike in young fish.
“This really demonstrates the power of this collaborative approach to conservation,” REEF Director of Science and study co-author Christy Pattengill-Semmens said. “We were able to monitor the population and provide information to support management as the data came in, allowing the Cayman government to respond rapidly with policy changes.”
Scripps Institution associate professor, ecologist and senior study author Brice Stemmens suggested that the strategy of managed fishing and patience used in the Cayman Islands are key to reviving depleted fish populations in other locations.
“This is an ideal approach for conservation,” Semmens said. “Just doing the science isn’t enough. You need to partner with groups and governments capable of turning science into conservation decisions that support the local community.”
— City News Service
