| Situation of the natural population |
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The actual size of the Gironde population, or more widely the North East Atlantic population and that of a possible relictual population in the Black Sea, remains unknown. However, due to the spectacular decline over the last decades, the number of adult individuals present in nature has most certainly become very limited, probably no more than a few hundred.
During the last half of the 1990s, the Black Sea population of European sturgeon venturing into the Rioni River in order to reproduce probably comprised no more than 300 specimens. Efforts made to capture some wild reproductive adults with a view to later artificial reproduction, as part of a population strengthening programme, nevertheless remained futile as it proved impossible to catch any fish before the programme terminated in 1998.
In France, the last two reproductions observed in a natural environment go back to 1988 and 1994 in the Gironde basin. The number of juveniles born in 1998 was estimated at between several hundred and several thousand individuals. On the other hand, genetic research strongly suggests that the 1994 cohort come from the same single reproductive couple. This bears witness to the very low number of spawners in the wild that are still active in their natural environment : less than 5 per year on average these last few years, compared to several dozen in the middle of the 1980s. Yet, there is new hope today thanks to the success of the latest artificial reproductions that have in particular enabled nearly 100,000 European sturgeon alevins to be released in 2007 and 2008 in the Gironde catchment area, in the waters of the Rivers Garonne and Dordogne.
Despite international protection given to the European sturgeon and its status as a protected species in French and European waters since, respectively 1982 and 1998, and in spite of significant efforts made in France since the end of the 1970s, its population remains in a particularly precarious situation.
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| Last Updated on Saturday, 07 November 2009 20:03 |