Current and past distribution PDF Print E-mail
The European sturgeon was once abundant along the maritime coasts and in most of the major European rivers, signifying one of the most extensive ranges.  It could be found in most of the European coastal waters of the North-East Atlantic (in particular the shallower waters of the North Sea and the Baltic Sea) and, to a lesser extent in the Black Sea and Mediterranean (including the Ligurian Sea, the Tyrrhenian Sea, the Adriatic Sea and Ionian Sea, the north of the Aegean Sea and the Marmara Sea).  Work carried out on the River Rhone by the Rhone-Mediterranean Migrators Association has confirmed the past presence of the species in the catchment basin from bones and stuffed trophy specimens (Pagès et al., 2008).  The presence of the species in the coastal waters of Iceland and the White Sea in North-West Russia was also notified, as well as along the Atlantic coasts and Mediterranean coasts of North Africa (especially off Casablanca, Oued Bouregreg and Fedala).
On the other hand, the species’ reproduction areas, situated in fresh water and only in European catchment basins, concerned the major rivers of the European continent.  Holcik et al (1989) enabled the historic range of the European sturgeon to be defined on the basis of an exhaustive inventory of the areas where the species was present.  Before its decline from the end of the 19th and the beginning of the 20th century, the species colonised over 30 European catchment basins.

Distribution_1850_(Internet) Distribution_2008_(Internet)

In less than a century, the accumulative effects of the deterioration of natural environments essential to the species and overharvesting of the fish to feed a flourishing market for caviar, deeply influenced the disappearance of almost all populations of the European sturgeon and, because of this, the extent of the species’ range. 

In the mid 1970s, two reproductive populations still persisted, the first in the Gironde Estuary (France) and the second in the Rioni River (Georgia), to the east of the Black Sea (Ninua, 1976).  The presence of the species in the Rioni River became gradually less frequent before becoming extremely rare.  Recent work there has indeed shown deterioration in conditions of access and reproduction. 

Consequently, the French hydrosystem is the last European basin that still has what may be remotely called a " population", and is even the last basin where the species still persists.  The marine range of this population, limited to coastal waters and shallow depths, now extends from the south of the Bay of Biscay to Scandinavia and around a part of the British Isles (Rochard et al., 1997).   Today, the European sturgeon is in critical danger of extinction (UICN CR A2d). 

 
Last Updated on Saturday, 07 November 2009 20:19