Scientists are asking divers not to cull lionfish at three Little Cayman sites as they begin a yearlong study of the invasive species.
Research assistant Savanna Barry, a graduate student of the University of Florida who is working at the Central Caribbean Marine Institute, said her team is assessing the impact of lionfish on native fish populations and also evaluating the success of community lionfish culls in Little Cayman. The yearlong study began last month.
Ms Barry said the researchers needed a baseline to which they may compare results. This baseline, or control, would be sites from which lionfish are not taken. These include Crystal Palace Wall, Rock Bottom Wall and from the area in front of Rock Bottom House between Cascades and the ICON station – all on the northern side of the island.
The research team is appealing to divers and lionfish cullers not to kill or capture lionfish on those sites.
“This will allow us to have a picture of what the reefs would be like without human interference in the lionfish invasion,” she said. “This is extremely important for the island because management decisions about lionfish can be made using this data and this study has the potential to show that we are making a difference out there.”
The scientists have chosen sites not usually frequented by customers of the local dive resorts and other divers.
“We are trying to figure out the impact lionfish are having on the native fish populations. A lot of research about lionfish has suggested they are going to have an impact on native fish populations, but no studies have actually demonstrated that,” Ms Barry said. “Another level of our study is assessing the effectiveness of the community culling on Little Cayman, whether the impact that the removal effort is having is positive.”
Lionfish were first spotted in the Cayman Islands in Little Cayman in 2008 and, since then, the invasive species has become a common sight near all three of the Cayman Islands.
In January 2011, management of resort and dive operations on Little Cayman joined forces with the Department of Environment and the Central Caribbean Marine Institute to organise community culls of lionfish, focusing mostly on Bloody Bay Marine Park, the most popular diving area of the island. They also carry out culls on the Preston Bay Marine Park and other areas outside the marine parks.
This is not the first time researchers have requested divers stay away from lionfish on certain dive sites. In summer 2010, researchers from Oregon State University investigating the growing invasion of lionfish asked divers not to take lionfish at Snap Shot and Sailfin Reef on the northern coast of the island over the summer months so they could study the fishes’ movements, survival, growth, and interactions with native predators and competitors to compare with their counterparts in the Pacific Ocean.
The latest study, carried out by the three-person team as well as volunteers, will involve researchers diving the three sites and carrying out “intensive visual surveys” of the lionfish and other species of fish and marine life present at the sites.
Ms Barry said this study would record the diversity and abundance of fish in areas where lionfish are present and also assess the biomass at the sites. Biomass is the mass of living biological organisms in an ecosystem at a given time.
The study is a joint effort between the University of Florida and the Central Caribbean Marine Institute, based in Little Cayman.