Abstract

In the tropical Western Atlantic, lionfish (Pterois volitans and P. miles) are highly invasive and can have negative impacts on ecosystems. In the Florida Keys (USA), divers have had some success in reducing lionfish abundance in waters within SCUBA diving depths; however, the depth range of lionfish greatly exceeds common diving limits. Commercial spiny lobster (Panulirus argus) fishers occasionally catch lionfish in their traps, particularly when using traps constructed primarily of wire at depths between 30 and 100 meters. The goal of this project was to modify wire-style lobster traps to increase lionfish catch in these deep waters while ensuring that the catch of other fish remained low. Modifications of the trap throat, throat location, escape gap size, and bait type were evaluated to determine the best trap designs with respect to bycatch reduction and lionfish catch. Simple modifications to these lobster traps increased lionfish catch and reduced bycatch. Two critical elements of creating a species-specific lionfish trap were: 1) a narrow top-entrance throat to preclude entry of legal-size lobsters and other large fish and 2) an escape gap to reduce the retention of small lobsters and small fish. These two trap design elements effectively reduced the catch of both lobsters and other fish, which was the key attribute to increasing the catch of lionfish. Bait type did not have a strong influence on lionfish catch. Fishers evaluated if the traps were an effective addition to their commercial fishing operations and generally concluded the experimental traps caught more lionfish than their standard spiny lobster traps and could be used to target lionfish at known lionfish aggregation sites. The use of lionfish-specific traps to enhance commercial fisher income remains to be assessed by individual fishers. However, the strategic use of this trap in no-fishing or marine protected areas could remove invasive lionfish while posing a smaller risk to non-targeted, native species compared to traditional lobster and fish traps.