Viable and ecosystem-based management for tropical small-scale fisheries facing climate change

Marine ecosystems, biodiversity and fisheries are under pressure worldwide because of global changes including climate warming and demographic pressure. In that regard, many scientists and stakeholders advocate ecosystem-based fishery management (EBFM). But how such EBFM can be operationalized in ecological-economic terms remains unclear. To address such issues, we propose a model of intermediate complexity (MICE) relying on multi-species, resource-based and multi-fleet dynamics, also taking climate effects into account. The model is calibrated for the small-scale coastal fishery in French Guiana. From the calibrated model, we compare different fishing species in terms of sustainability through to 2070, including a predictive strategy and the normative strategies entitled Multi-species Maximum Sustainable Yield, Multi-species Maximum Economic Yield and Ecoviability. The sustainability assessment of fishing strategies relies here on profitability, food security and biodiversity constraints to be fulfilled over time. The results point overall to the long-term detrimental impact of climate change. The prognosis is particularly catastrophic under the most pessimistic climate scenario (RCP 8.5), with a potential collapse of both biomass of targeted species and fishing activity by 2070, regardless of the fishing strategies. However, under the optimistic scenario (RCP 2.6), our results demonstrate the interest of Ecoviability strategies in order to ensure sustainability and ecosystem-based management of fisheries. Such EVA strategies require a major reallocation of the fleets operating in the fishery.