Navigating complexity: Evaluating management measures for multispecies snapper-grouper fisheries in the Southeast U.S. Atlantic.

Multispecies fisheries are globally common, but typically managed through single-species controls. This situation can result in wasteful discarding, when fish of some species cannot be retained, but fishing effort toward the complex continues. In contrast, managing multispecies fisheries through effort controls can address this shortcoming. In this study, we used a simulation model to examine the effectiveness of various temporal and spatial effort controls applied to the multispecies snapper-grouper fishery in the southeast United States Atlantic. To represent the complex, we chose six species that are most commonly caught by the commercial and recreational sectors. We evaluated the various management scenarios based on performance metrics that quantify effects on spawning biomass, commercial and recreational landings, commercial and recreational discards, and economic indicators for both fishing sectors. These performance metrics were applied to both the species individually and in aggregate. We found that some management approaches were more effective than others, but that no single approach worked best for all species and both sectors. The optimal strategy depends on policy priorities, balancing potential tradeoffs between conservation goals (e.g., increased spawning biomass), harvest objectives (e.g., increased landings, decreased discards), and economic outcomes. Our modeling framework quantifies those tradeoffs.