Cayman lionfish study under way

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. 

lionfish hunting

Scientists want divers to stay clear of three sites where they are studying lionfish. – PHOTO: FILE


  1. A 20 year ban on Grouper fishing in the Exuma Cays Land and Sea Parks (ECLSP) has allowed predatory groupers to attain some of the highest biomasses reported anywhere in the Caribbean. Thus the ECLSP and it’s surrounding areas provide an unusual opportunity to examine the potential of groupers to act as a natural biocontrol of non-native lionfish. Awesome scientific report.

    PLoS ONE: Grouper as a Natural Biocontrol of Invasive Lionfish
    PLoS ONE: an inclusive, peer-reviewed, open-access resource from the PUBLIC LIBRARY OF SCIENCE. Reports of well-performed scientific studies from all disciplines freely available to the whole world.

    Ms Barry there is already a on going baseline to which you may compare results as stated above. Over the next year you are going to allow millions of juveniles to be eaten by these Lionfish. Spend your time killing this invasive species.

  2. Divejay – Little Cayman has what is considered the last healthy grouper aggregation spawning site left in the Caribbean Basin. We have what is also found at ECLSP, but more so. That is not the point however. Without the No-Cull baseline sites here on Little Cayman the research would not pass a peer review and would not be publishable. For better or worse, that is how science works. The three (3) sites to be removed from culling efforts are all remote, seldom dived, and have not been on any of the weekly volunteer culling trips scheduled through each of Little Cayman’s Dive operations.

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