Coherent assessments of Europe’s marine fishes show regional divergence and megafauna loss

Abstract

Europe has a long tradition of exploiting marine fishes and is promoting marine economic activity through its Blue Growth strategy. This increase in anthropogenic pressure, along with climate change, threatens the biodiversity of fishes and food security. Here, we examine the conservation status of 1,020 species of European marine fishes and identify factors that contribute to their extinction risk. Large fish species (greater than 1.5 m total length) are most at risk; half of these are threatened with extinction, predominantly sharks, rays and sturgeons. This analysis was based on the latest International Union for Conservation of Nature (IUCN) European regional Red List of marine fishes, which was coherent with assessments of the status of fish stocks carried out independently by fisheries management agencies: no species classified by IUCN as threatened were considered sustainable by these agencies. A remarkable geographic divergence in stock status was also evident: in northern Europe, most stocks were not overfished, whereas in the Mediterranean Sea, almost all stocks were overfished. As Europe proceeds with its sustainable Blue Growth agenda, two main issues stand out as needing priority actions in relation to its marine fishes: the conservation of marine fish megafauna and the sustainability of Mediterranean fish stocks.arine fishes exhibit high biodiversity 1,2 and have been culturally and nutritionally important throughout human history 3 . Europe, in particular, has a well-documented history of exploiting marine fish populations, written records of which commence in the classical works of ancient Greece. Although this historical exploitation has undoubtedly altered populations 4,5 and changed many seascapes 6 , marine defaunation in the region has not been as great as in terrestrial systems 7 . However, the use of ocean space and resources is increasing due to Europe's Blue Growth strategy 8 , the nutritional requirements of an expanding human population are growing 9,10 and marine ecosystems will experience unusually rapid changes in future due to climate change 11,12 . Consequently there are imminent threats both to European marine biodiversity and fish resources 13 . 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.We analysed data on the conservation status of 1,020 species of Europe's marine fishes from the recent International Union for Conservation of Nature (IUCN) Red List assessments 14 to identify characteristics that make Europe's fishes most susceptible to extinction risk. We then compared the Red List with 115 fish stock assessments (of 31 species) made by intergovernmental agencies charged with providing advice on the exploitation of commercial fishes. Previous comparisons of this sort applied criteria under various modelling assumptions [15][16][17] or limited the comparison to biomass reference points 18 . ResultsOf the 1,020 European marine fish species that were asses...

Status and rebuilding of European fisheries

“…4) is confirmed by Fernandes et al [41] who examined 95 assessments in European waters and report 19 sustainable stocks in the Northeast Atlantic and none in the Mediterranean.…”

Improved management is the main driver behind recovery of Northeast Atlantic fish stocks

“…Additional challenges remain, especially for species with little or no commercial value or for which data are deficient, and for specific regions, such as the Mediterranean Basin (although not considered in the present study, areas like the Mediterranean are highly relevant for marine biodiversity and regional subsistence; Fernandes et al . ). Our findings highlight the need for marine resources to be managed in a manner consistent with the science, and that also considers interactions between ecosystems and non‐commercial species, which contrasts sharply with current practices (Skern‐Mauritzen et al .…”

Accounting for ocean connectivity and hydroclimate in fish recruitment fluctuations within transboundary metapopulations

“…), of which more than 90% are in overexploitation state (Fernandes et al. ). This urges for effective measures and population dynamics modeling that realistically capture the ecological complexity of harvested populations.…”