European sea sturgeon
According to the French national red list, the European sea sturgeon is a threatened species in France.
The European sea sturgeon, the largest migratory fish in France, spends most of its life in the sea and returns to fresh water to reproduce.
In the past it was found in all the major rivers of Western Europe. This amphihaline species has gradually disappeared over the 20th century from most of its range. There is now only a single population of a few thousand individuals of which the last reproduction sites are limited to the Gironde-Garonne-Dordogne drainage basin, and of which the young and adults live in the waters of the Northeast Atlantic, the English Channel and the North Sea.
The species is classified " critically endangered" in France as well as globally.
French national red list category: critically endangered (CR)
A vulnerable species
Fished for a long time for the quality of its flesh and for the production of caviar, the European sea sturgeon has suffered greatly from overfishing. Although it is protected and its fishing is prohibited in France since 1982, it is still caught accidentally at the mouths of large estuaries or in the sea.
The destruction of its habitat by theextraction of aggregate in rivers and estuaries has increased the species' vulnerability. The presence of dams is an additional threat to its migratory course as existing fish passageways are not adapted to its large size. Furthermore, the high age of sexual maturity (10 years for males and 15 years for females) means that the population renewal rate is very slow.
Legal protection of the European sea sturgeon
The European sea sturgeon is notably included in annexes II and IV of the European " Habitats" directive (1992) and in Annex I of the Washington Convention on International Trade in Endangered Species (CITES, 1973). In France it is the subject of a national action plan which especially includes:
- raising awareness in professional fishermen to encourage them to release these fish in the event of accidental capture;
- development of reproduction methods in captivity.
Developed by the French public agricultural and environmental research institute (CEMAGREF), these methods support the species' repopulation by releasing young fish into the natural environment.
European sea sturgeon. © Cemagref