Trends on the state of Mediterranean fish stocks

The Mediterranean Sea is not only a one of the world’s biodiversity hotspot but also is considered as one of the most important fishing area playing a crucial socio-economic role. However, recent studies indicate a worrying state of its main commercial fisheries. In this respect, considerable efforts are deploying at regional level to improve the status of Mediterranean fisheries on which many millions of peoples depend and this through providing management recommendations, establishing multi-annual management plans and developing strategies. With the overall objective of performing an up-to-date deeper spatio-temporal diagnostic of Mediterranean stock status, the annual validated assessments by scientific experts were collected, from which the available current values and available times series of indicators of recruitment (R), of fishing mortality (F) and of stock biomass (SSB and TB) as well as the set of established reference points were extracted. The stock status analysis was provided applying different approaches (meta-analysis and stock-by-stock analysis), using several indicators applied at different scale of aggregation. Which allowed diagnosing the current and the temporal trends of status of main Mediterranean fisheries at regional and sub-regional level as well as pointing out the different state of functional groups and individual stocks. The findings of the present study clearly show that the Mediterranean assessed stocks are in a worrying status being the majority outside safe biological limits either in terms of biomass, exploitation or both criteria and that the degree vary among stocks, functional group and geographical sub-areas. It was revealed that the Western Mediterranean stocks are in the worst state compared to the others Mediterranean sub-regions. Among functional groups, the small pelagic showed the better status compared to demersal fish and crustaceans. Out of the 87% stocks subjected to the overexploitation (F > FMSY), 21% are currently in a low overfishing level from them 33% of assessed stocks are so close to reach the target level and among the 69% of stock with biomass below the threshold empirical reference point, 12% are close to reach the reference point. Those stocks request only a least of 10% of fishing mortality reduction to shift their status from an overfishing to a rational exploitation. Among all examined individual stocks, the red mullet in the strait of Sicily showed the lowest relative biomass level. On other hand, some stocks are very hardly harvested such as the stock of hake in Gulf of Lions that is exploited around 13 times greater than the MSY level. The assessment of stock status based on a simultaneous analysis of the status of stock size and fishing mortality reflects better the status of stocks specially when it is presented on Kobe plot using both threshold and limit reference points. This kind of analysis provide more complete picture when it is enhanced with updated information on fishery such as the sensitive species habitats, fishing grounds, catch composition and historical landings.