Improving the performance of a Mediterranean demersal fishery toward economic objectives beyond MSY

Abstract

Mediterranean demersal fisheries are highly multispecific and many of their target stocks are overex-ploited. In addition, rocketing fuel costs and low market prices of traditionally high-value species arechallenging the viability of fisheries. Here, based on the numeric results of a simulation model, we con-clude that this situation can be remedied by reducing both fishing mortality and fishing costs. Accordingto our model results, fishing effort reductions of 48–71% would improve the health of fish stocks whileincreasing the economic profits of Mallorca islands bottom trawl fishery to as much as 1.9 MD (146%higher than current profits). If all fish stocks were exploited at their MSY (or below) level, the reductionin fishing effort would have to be of 71% from current values. If equilibrium profits from the fishery wereto be maximized (MEY), fishing effort would need to be reduced by 48%. These results must be takenwith caution due the many sources of uncertainty of our analysis. The modeling tools used to estimatethese values are conditional to the adequate treatment of two sources of uncertainty that are partic-ularly problematic in Mediterranean fisheries: insufficiently known recruitment variability and lack ofperiodic evaluations of the state of many species. Our results show that fishing effort reductions wouldproduce economic yield gains after a period of transition. Further studies on the benefits of changing thesize-selection pattern of fisheries, on better estimation of stock–recruitment relationships and on betterquantifications of the contribution of secondary species to these fisheries, are expected to improve thescientific recommendations for Mediterranean demersal fisheries toward sustainability principles.