|Abstract or Summary
- Unilateral conservation of a transboundary resources, notably bycatch species, can lead to production, trade, and conservation leakages, losses in net benefits to society, and, paradoxically, increased rather than the intended decline biodiversity loss. A 2001 time-area closure of a key fishing area for the California-Oregon drift gillnet fleet harvesting swordfish aimed to reduce sea turtle bycatch. A cost-benefit analysis demonstrates a loss in US PFMC Region consumer and producer benefits, in which predominately frozen imported swordfish replaced lower landings of local, fresh swordfish. Counterfactual models predicted the “without” closure activity for swordfish imports, consumer benefits for imported and domestic swordfish, and drift gillnet fleet sie. Producer benefits fell due to 11 vessels exiting the fishery and lower supply chain benefits. The closure led to increased net sea turtle bycatch due to higher foreign bycatch rate per ton of swordfish caught. Over 11 years, present value of total consumer and producer benefits ranged between $26,114,109 if exiting vessels fishing in another fishery to $27,470,916 if vessels completely exited fishing. Net turtle bycatch increased by 1,457 animals. The results demonstrate that bycatch reduction of transboundary species, such as marine megafauna, requires multilateral rather than unilateral conservation.