Evaluating optimal removal of derelict blue crab pots in Virginia, US

Derelict fishing gear is a growing concern in many fisheries and coastal communities. Pots and traps are prevalent forms of derelict fishing gear with numerous documented harmful effects. In the Chesapeake Bay, US, a large blue crab (Callinectes sapidus) pot fishery produces high levels of derelict gear. From 2008 to 2014, 34,408 derelict pots were removed from blue crab fishing areas in Virginia. This research first evaluates whether observed increases in catch rates occurring contemporaneously with the removal program were the result of derelict gear removals. An econometric production model is then used to estimate marginal removal benefits and assess optimal removal levels. Fishing locations with removals during the removal program were estimated to have experienced increases in harvest per pot and harvest per trip of 22.35% and 34.68%, respectively. Optimal removal levels were found to depend on location-specific fishing effort, with high-effort areas yielding greater marginal removal benefits. Fishery productivity gains, though large, were found to last only one year following removals. Assuming a removal cost of $100/pot, the optimal level of removals was estimated to be over 7000 pots/year and would generate productivity gains of ~17–18%, yielding over US $3M in annual net benefits to the commercial fishery. Optimizing mitigation and management strategies for derelict fishing gear and marine debris requires quantitative assessment of the benefits and costs of alternative policy measures.