A multi-criteria approach to support decision making in ecosystem-based fisheries management

Ecosystem-based fisheries management (EBFM) requires tools capable of integrating ecological, economic, and social information while making trade-offs explicit. We applied a multi-attribute utility theory (MAUT) framework to evaluate alternative management strategies in three case studies: the mixed fisheries of the Central Mediterranean, the Bay of Biscay, and the North Sea. Bioeconomic and ecosystem modelling outputs were translated into utilities for twelve indicators representing stock status, biodiversity, benthic habitat condition, climate mitigation, community wellbeing, and economic viability. Management strategies included the status quo (SQ), rules based on maximum sustainable yield (MSY) and pretty good yield (PGY), and case-specific measures, assessed under current climate conditions and two climate change projections (RCP4.5, RCP8.5). Utilities were aggregated using alternative weighting schemes representing different value priorities, with emphasis on either environmental or economic objectives. MSY and PGY generally provided the best compromise between ecological and socio-economic performance, outperforming SQ, which ranked lowest in the North Sea and Central Mediterranean but highest in the Bay of Biscay when economic objectives were prioritized. Climate impacts were region-specific: modest in the Central Mediterranean, strategy-dependent in the Bay of Biscay, and strongly negative in the North Sea. Technical and spatial measures improved specific objectives but did not alter overall rankings. Overall, our results demonstrate that MAUT provides a transparent and flexible decision-support tool to synthesise complex model outputs, make trade-offs and value-dependencies explicit, and support robust EBFM advice.