Writing in Nature Ecology and Evolution, an international team of scientists have identified the fish species particularly at risk, which include sturgeon, the Atlantic halibut (Hippoglossus hippoglossus) and wild Atlantic salmon (Salmo salar).
The scientists point to a greater vulnerability and threats such as overfishing because they grow more slowly, take longer to mature, have fewer offspring and are in higher demand for food consumption.
According to Paris Vasilakopoulos from the European Commission's Joint Research Centre (JRC) and co-author of the study, the threats to large fish species and the severe overfishing in the Mediterranean is in contrast to the improving picture in the northeast Atlantic.
“In the northeast Atlantic, there are catch limits in place, coupled with rigorous fisheries monitoring and enforcement schemes.
“In the Mediterranean there is a larger number of fishing vessels using multiple gears, there are largely no catch limits, and management is carried out mainly through some spatial and temporal restrictions to fishing, which are often poorly enforced.”
Despite the warning, the study pointed out that most of Northern Europe’s commercial fish stocks were in a healthy state and not yet threatened with extinction.
“In terms of the conservation of commercially fished species, management agencies in northern Europe had succeeded in reducing fishing pressure and, in some cases, populations were recovering.”
Fishing for insight
The research team that included scientists from the Universities of Aberdeen and Strathclyde, collaborated with the JRC, who analysed stock assessment data of commercial fish stocks in the Mediterranean Sea.
When compared with the northeast Atlantic, a much higher portion of the fish stocks were overexploited and depleted in biomass in the Mediterranean.
Worryingly, none of the 39 assessed Mediterranean fish stocks examined were classed as sustainable.
Of the 12 examined hake stocks in the Mediterranean, nine had exploitation rates that were over five times higher than the rate in line with maximum sustainable yield.
“The use of ocean space and resources is increasing due to Europe’s Blue Growth strategy,” the study said.
“The nutritional requirements of an expanding human population are growing and marine ecosystems will experience unusually rapid changes in future due to climate change.
“It is important, therefore, to assess the threats of extinction to fish species and to ensure consistency in the management approach by the various agencies involved.
The Blue Growth strategy refers to the sustainable growth achievable in the marine and maritime sector.
The European Commission (EC) believes the 'blue' economy represents roughly 5.4 million jobs and generates a gross added value of almost €500 billion a year.
In recent times, the EC has tried to rebalance harvesting activities and stock productivity.
Modern EU regulations against overfishing apply domestically so the EC has established working relationships with non-EU Mediterranean countries to extend regulation reach.
This is achieved through international channels such as the General Fisheries Commission for the Mediterranean, the International Commission for the Conservation of Atlantic Tunas and the Barcelona Convention.
Similarly, regions-specific conservation initiatives for the Adriatic-Ionian and the western Mediterranean are now being developed.
The Commission recently launched the MEDFISH4EVER strategy to improve the state of Mediterranean fish stocks, which Vasilakopoulos said was “a step to the right direction.”
Set up in March this year, the strategy was signed by 15 fisheries ministers that included Spain, France, Italy, Malta, Slovenia, Croatia, Greece and Cyprus.
The countries vowed to take action to improve fisheries governance in the region.
Examples of initiatives underway include upgrading data collection and scientific evaluation, establishing an ecosystem-based fisheries management framework and firmer efforts to combat illegal, unreported and unregulated fishing.
The 10-year long partnership, which also includes countries such as Morocco, Algeria, Tunisia, Egypt, Turkey, Albania, Montenegro, have plans to extend its reach to other countries.
Source: Nature Ecology and Evolution
Published online ahead of print: doi:10.1038/s41559-017-0170
“Coherent assessments of Europe’s marine fishes show regional divergence and megafauna loss.”
Authors: Paul Fernandes, Gina Ralph, Kent Carpenter