Big fish trouble in Europe, especially the Mediterranean
Drawing on the recent European Red List of Marine Fishes and fish stock assessments by government agencies, two major issues are evident from an analysis of the extinction risk and status of Europe’s marine fishes: the threats to large fish, the so- called megafauna, and an overfishing problem in the Mediterranean.
Marine fish are a diverse group of animals that play important roles in marine ecosystems, as well as being a major food source for marine and terrestrial mammals, notably humans. Nowhere is this more the case than in Europe, where we have been fishing for millennia. In spite of this, there are still “some” fish left in the sea, but not plenty. Exactly how many and what types, or species, are left, is revealed in our paper “'Coherent assessments of Europe’s marine fishes show regional divergence and megafauna loss”. Large fish are at risk in Europe, the bigger the fish species the more likely it is to be threatened with extinction: in fact, over 50% of all species which grow to a size of 1.5 metres or more are threatened with extinction. Many of these are cartilaginous fish (sharks, skates and rays), but they also include sturgeons and some other fish. Large fish species are more susceptible to threats such as overfishing, because they grow slower, take longer to mature and have fewer offspring; they are also more sought after.
We then examined the status of commercial fish stocks all around Europe and found a remarkable geographic contrast. In the Northeast Atlantic, almost twice as many stocks were sustainably fished (19) as overfished (10); 8 stocks were recovering (the fishing rate is not high, but their populations are small); and 19 were declining (their populations are healthy, but the fishing rate is now too high). However, in the Mediterranean Sea, almost all stocks examined in our study were overfished (36 of 39) and not one was sustainable. This comes down to how the areas are managed and the unique nature of the fishing communities in the two areas. In the Northeast Atlantic, there is a complex (& expensive) fishery monitoring and enforcement system, which sets quotas and other regulations to keep fish stocks healthy. In the Mediterranean, however, in addition to the economic challenges of the surrounding nations, such monitoring & enforcement would be even more expensive, because there are many more fishermen scattered in many small fishing ports. Hence there are largely no quotas in the Mediterranean, only some protected areas and some limits on the amount of fishing time; the area also has more pressing economic and food security concerns.
A typical scene in the Mediterranean showing a fishing village which has become a popular tourist destination (an example of "Blue Growth"). Throughout the Mediterranean, fishing is more like a subsistence culture with thousands of fishermen operating from small ports like these, making enforcement and monitoring of catches logistically challenging and prohibitively expensive. Picture credit: Paris Vasilakopoulos.
We have highlighted two major issues for Europe’s fish: the threats to large fish, the so- called megafauna, and the overfishing problem in the Mediterranean. Europe is proceeding with a Blue Growth agenda, aiming to expand its use of marine space in aquaculture, mining, renewable energy, tourism and biotechnology: as it does so it needs to take care of the megafauna and improve fishery management in the Mediterranean.