Unraveling the combined effects of sociopolitical and climate change scenarios for an artisanal small-scale fishery in the Western Mediterranean

Worldwide climate change will influence the spatial distribution and status of exploited fish stocks, often in uncertain ways with cascading effects on the social-ecological systems depending on them. Likewise, changes in sociopolitical conditions influencing consumer demand, fuel, and fish prices may jeopardize the viability of fisheries. Predicting whether existing management systems can adapt to these changes is key and especially challenging in data-poor fisheries. In the Mediterranean Sea, the tropical and subtropical dolphinfish (Coryphaena hippurus) is at its northernmost reproductive distribution area and has sustained a seasonal age-0 based artisanal small-scale fishery since ancient times. We built a quantitative Bayesian Belief Network (BBN) model integrating a diverse set of ecological, social, and economic input data to assess the impact of plausible midterm futures (2040-2059) on the seasonal economic profit for dolphinfish fishers in Mallorca (Balearic Islands, Western Mediterranean). These future scenarios accounted for increasing sea surface temperature based on global IPCC projections, population dynamics and growth of dolphinfish, economic forecasts of future fish and fuel prices, and stakeholders' views on feasible adaptations of the local management system. Seven out of twelve scenarios point towards increased profitability for fishers. To date, the fishery is managed locally although within a wider EU regulatory framework, and options such as advancing the opening date of the fishing season in response to climate-induced changes in growth and body size of dolphinfish might be economically beneficial. This will, however, depend critically on the evolution of unknown factors such as changes in other target species, consumption habits of people, and market dynamics. We show here that, even in fisheries without information on stock status, an integrated and holistic assessment of adaptive capacities of management systems is possible.