Parameterization of an Ecosystem Model and Application for Assessing the Utility of Gulf of Mexico Pelagic Longline Spatial Closures

Many highly migratory predator stocks that occupy the Gulf of Mexico are at risk, and the collapse of stocks could harm fisheries and ecosystems. Two pelagic longline spatial closures within the pelagic waters of the Gulf of Mexico have been established to protect pelagic species. In 2000, a permanent closure was established around DeSoto Canyon, with the management objectives of reducing catch and rebuilding biomass of bycatch and incidental catch species while minimizing impact to catch of target species. In 2015, a seasonal closure was established off the Louisiana shelf (Spring Closure), with the management objectives of reducing catch and rebuilding biomass of bluefin tuna (Thunnus thynnus). Pelagic spatial closures are relatively untested management tools. Science-driven analysis, including the investigation of ecosystem impacts through mathematical modeling, is necessary to address their utility. This dissertation presents research used to parameterize an ecosystem model, Atlantis, for the Gulf of Mexico marine ecosystem, followed by a study that used the Gulf of Mexico Atlantis model to conduct a policy exploration of the utility of Gulf of Mexico pelagic longline spatial closures...

...The Atlantis framework allowed for the detailed, spatially-explicit representation of biota, fleets and spatial closures, and provided a means to explore broad-scale ecosystem impacts...

...This dissertation found that pelagic spatial closures could be viable means to achieve management objectives for protecting highly mobile pelagic predators from fishing pressure.