A management strategy evaluation of dynamic and static closures in a swordfish fishery: balancing economic and bycatch concerns

Dr James Smith^1,2, Dr Desiree Tommasi^1,2, Dr Michael  Jacox³, Dr Elliot Hazen^1,3, Dr Heather Welch^1,3, Dr Stephanie Brodie^1,3

¹University of California Santa Cruz, , United States, ²NOAA Southwest Fisheries Science Centre, La Jolla, United States, ³NOAA Southwest Fisheries Science Centre, Monterey, United States

The dynamic distributions of many marine species complicates their spatial management. Management strategies for minimizing fisheries bycatch, for example, can include static closures during periods of high bycatch risk. But the changing distributions of both target and bycatch species can greatly affect the success of these closures, and dynamic ocean management (DOM) is considered a valuable alternative to static approaches.

We conducted a management strategy evaluation (MSE) for a U.S. swordfish fishery to: 1) quantify the impact of existing static closures on catch and bycatch; and 2) compare this impact to a multi-species DOM tool (EcoCast) used in the simulation to indicate bycatch risk. We found that using EcoCast instead of the static closures increased fleet-wide swordfish catch by 15-30%, while also achieving a reduction in turtle bycatch. The economic benefits varied greatly among fishing ports, depending on their proximity to closures. A clear advantage of using DOM was that less area was ‘closed’ to fishing than with the static closure, and that this area shifted with species’ distributions.

Our simulation demonstrates an approach for combining statistical catch models with an agent-based fishing model to conduct environmentally-driven MSE at a fine spatial scale. Our simulation also revealed that measuring the absolute performance of different management strategies required more defined economic and conservation goals (such as bycatch limits) than currently exist for this fishery.

Biography:

James recently left Australia for San Diego, and is currently a project scientist at NOAA/UCSC,  working on a project exploring impacts of climate change on the California Current. He is disappointed that ‘Anchor Man’ wasn’t actually filmed in San Diego, but wow the weather is nice.