NCCOS Project Explorer (NPE)

Derelict Traps and Casita Debris in the Florida Keys National Marine Sanctuary: Distribution, Habitat Impacts, and Bycatch Mortality(2008)

Project Description:
Spiny lobster and stone crab trap debris and casitas (artificial structures illegally deployed by divers to attract lobsters for subsequent harvest) are common features along shorelines and in nearshore waters of the Florida Keys. Tens of thousands of traps are lost annually during routine fishing and hundreds of thousands of traps are lost during hurricanes. The number of casitas is unknown but a recent cleanup effort removed 66 tons of debris. In addition to presenting a hazard to navigation and public health and safety, derelict traps and casitas may both have an impact on Essential Fish Habitat (EFH) as they rest directly on top of habitat features and move during storms. Traps may also continue to actively fish, causing mortality of confined animals. Little data exists on the impact of traps and casitas on EFH or the extent of lobster, crab, and bycatch mortality from derelict traps. This project uses towed-diver surveys throughout the Florida Keys National Marine Sanctuary (FKNMS) to document the distribution of derelict trap debris and casita structures and the extent of habitat damage from both. We specifically identify debris in sand, seagrass meadows, algae beds, hardbottom, and low-relief coral habitats. Additionally, we estimate mortality of lobsters and other confined animals due to derelict traps. This project will result in a distribution map of primary habitats in the FKNMS affected by debris, the extent of habitat damage from both derelict traps and casitas, and the estimation of lobster and other confined animal mortality due to derelict traps. In combination, these key pieces of information will help more effectively manage the trap fisheries in the FKNMS by providing quantitative information on the existence and extent of the debris problem and identification of specific targets for remedial action.

Expected Outcome:
The towed-diver debris surveys will provide critical data on the distribution of trap and casita debris, the impact of this debris to habitat, and lobster and by-catch mortality. Specifically, this project will result in the estimation of lobster mortality due to derelict traps, a distribution map of primary habitats affected by debris, the extent of habitat damage from both derelict traps and casitas, and the estimation of confined animal mortality due to derelict traps. In combination, these key pieces of information will help managers more effectively manage the trap fisheries in the Florida Keys by providing quantitative information on the existence and extent of the debris problem and identification of specific targets for remedial action. This project will fulfill FKNMS habitat management requirements, facilitate revision of EFH provisions in regional fishery management plans, promote informed industry decision-making with respect to trap placement, the need for gear removal at the end of the season or at the onset of severe storms, and the effect of derelict gear on EFH, and encourage a more effective and ongoing debris removal program in the FKNMS.