Brad Walker

Researchers target five habitat areas in the Florida Keys to assess lionfish populations to help develop a management plan for the invasive species

If you fish, dive or conduct other aquatic activities in Florida, you may have encountered a lionfish. Its exotic, zebra-like appearance is hard to miss, and biologists aren’t overlooking the negative impact this invasive species is having on Florida’s marine life. The lionfish is a non-native predatory reef fish that feed on native Florida fish and competes with them for food. Because they have no known predators in Florida waters, lionfish are spreading rapidly. Biologists and fisheries managers are well aware, and the FWC recognized the importance of controlling the lionfish population and the difficulties associated with managing a highly invasive species in a marine environment.

A large-scale lionfish eradication has been proposed in recent years, but results from past lionfish studies determined that wiping the species out completely may not be possible even with substantial financial resources. Population control is the next viable option, so in 2013 the FWC began a research study funded by the Conserve Wildlife Tag program to study the species in five selected reef habitats in the Middle Florida Keys. Researchers identified key habitats affected by lionfish and studied the impact of lionfish on local fish populations. The study’s goal is to provide managers with guidelines to prioritize locations for lionfish management and inform stakeholders of effective control strategies.

Project scientists selected five different reef habitat types representative of the Florida Keys for targeted removal efforts. At these habitat sites, researchers are assessing the rate of recolonization after lionfish are removed, as well as changes in the number of native species. To do this, researchers use monthly visual assessments. The team perform an initial visual assessment before removing any lionfish. Following the initial assessment, researchers remove all lionfish from the targeted habitat sites. Subsequent monthly visual assessments allow researchers to document newly settled lionfish and determine how quickly the species recolonizes these habitats. By maintaining a lionfish-free environment through systematic monthly removals, researchers will be able to determine whether lionfish negatively affected populations of native species. Researchers believe that fewer lionfish in these habitats will result in an increase in native fish.

In another aspect of the project, scientists are using acoustic tracking technology and video monitoring to observe lionfish behavior and movement patterns. Movement and behavior data will provide fishery managers with accurate community structure information and enable scientists to determine how often lionfish migrate between adjacent sites. By determining how often lionfish venture to and from adjacent sites and how far they travel, we will be able to accurately estimate the true home range of lionfish.

Learning more about lionfish will increase our capacity to effectively manage this fish and its negative effects. Instead of a short-term fix, researchers and managers are working together to develop a long-term plan for effective, sustainable management of lionfish in Florida waters.