Different species of sturgeon or hybrid stocks are reared today, in both France and throughout Europe, for commercial purposes (mainly for caviar), for introduction into closed water for angling or for use as an ornamental fish.  Breeding hybrid sturgeon from two distinct species is, in general, of technical and/or financial interest for fish farmers.  Moreover, this type of farming is not subject to restrictions imposed by the CITES Convention.  These sturgeon, the introduction of which into open French waters is strictly prohibited, may also be sold on the open market.

The Siberian sturgeon ( Acipenser baerii) is the main species reared in France; it has been observed in most of the major French basins (Loire, Seine, Adour, Garonne, Dordogne, etc.) and may have accidentally escaped or been deliberately introduced.  Even though the reared "Baerii" does not tolerate salt water, it can cohabite with the “Sturio” in the lower river stretches and especially in the Gironde basin.  Hybridisation of the two species, mastered under experimental conditions, has however never been observed in the natural environment.  Additionally, the possibility of competition for food between the two species has been put forward by some who work in the environment..

Baerii capturé sur l'Adour en 2008

If the possibility of hybridisation and competition with the Siberian sturgeon seem at the moment to be very hypothetical, the risk of confusion between the two species is, on the other hand, a clear reality.  It may prove detrimental to the protected European species insofar as the fishermen and administrators ignore the existence of the two distinct species and consider that the situation of “the sturgeon”, associated in this case with the fish reared to produce the highly publicised caviar, does not justify so many precautionary and protective measures, and consequently, so much implication in this effort to save the fish.  In order to rectify this situation, specific information has been disseminated to fishermen in the major French estuaries in which the two species may occasionally co-exist.

 

Lately new hybrid species have made an appearance in closed waters and in certain fish farms in France.  They have already been regularly observed in certain waterways of neighbouring countries. 

 

Member States of the Bern Convention have agreed to work on developing European and national legislation that would limit the risks associated to the introduction of the species or allochtonous, or non-indigenous, stock.  The definition of a school of thought and adapted recommendations is anticipated within the plans for the restoration of the species in France.