Estimating the Benefits of Derelict Crab Trap Removal in the Gulf of Mexico

Abstract

AbstractGhost fishing in derelict blue crab traps is ubiquitous and causes incidental mortality which can be reduced by trap removal programs. In an effort to scale the benefits of such removal programs, in the context of restoring the Gulf of Mexico after the Deepwater Horizon oil spill, this paper calculates the ecological benefits of trap removal by estimating the extent of derelict blue crab traps across Gulf of Mexico waterbodies and combining these estimates with Gulf-specific crab and finfish mortality rates due to ghost fishing. The highest numbers and densities of traps are found in Louisiana, with estimates ranging up to 203,000 derelict traps across the state and up to 41 traps per square kilometer in areas such as Terrebonne Bay. Mortality rates are estimated at 26 crabs per trap per year and 8 fish per trap per year. The results of this analysis indicate a Gulf-wide removal program targeting 10% of derelict traps over the course of 5 years would lead to a combined benefit of more than 691,000 kg of crabs and fish prevented from mortality in ghost fishing traps. These results emphasize the importance of ongoing derelict trap removal programs. Future work could assess additional benefits of trap removal programs, such as fewer entanglements of marine organisms, improved esthetics, and increases in harvestable catch. Lastly, this model could be utilized by fishery managers to calculate the benefits of other management options designed to decrease the extent and impact of derelict fishing gear.