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Successful artificial reproduction of the European sea sturgeon Acipenser sturio

23.07.2007
Despite its status as an endangered species in France since 1982 and in Europe since 1998, the last population of the European sea sturgeon has continued to decline. Today, only a few thousand individuals remain, all native to the Gironde River.

In Bordeaux, researchers were rushing to build up stocks of parent fish and set up artificial reproduction methods in an attempt to produce sturgeon fry. This objective was met on 25 june 2007 at the Cemagref fish station in St-Seurin-sur-l’Isle, in the Gironde area.

Sturgeon fry under close surveillance

The parent's are part of the sturgeon stock created from young fish born in the mid 1990s and kept in captivity since that time. After more than 10 years of daily care and effort on the part of the research team, a female (Francine, born in 1994 and weighing 8.5 kg) and two males (Justin, born in 1984, 24 kg, and Emile, born in 1994, 17.6 kg) provided slightly more than 11,000 larvae.

Depending on how successful these early-stage fish are, very fragile until they begin taking on food, and limited by the mother's weight and young age, this first reproduction should provide a few thousand fry.

Part of these fish are expected to reinforce the two stocks in captivity as part of the species’ preservation and restoration programme in Europe: one in France (the Cemagref fish station at St-Seurin-sur-l’Isle) and the other in Germany (the Freshwater Institute of Berlin). Depending on the success rearing these fry, the remainder should be released into the wild in the Garonne and Dordogne rivers, undoubtedly at the beginning of September, to sustain the wild population whose numbers are currently at their lowest.

Towards other artificial reproduction to stimulate reimplantation of the species
The last artificial reproduction dates back to 1995 : 9000 larvae and fry were released into the wild in the Garonne and Dardogne rivers, thus reinforcing the relictual population. The follow-up of the fish released during marking operations or accidental captures in the Gironde estuary and at sea, and finally during their return to the rivers where a few have been identified over the past few years, shows just how effective these measures have been.

The sturgeon in captive stocks, progressively built up since the mid-1990s, are now approaching sexual maturity. This first success in artificial reproduction of the European sea sturgeon, from fish reared in captivity, demonstrates the soundness of this solution. It compensates the absence of any natural reproduction since 1994, given the rarity of parent fish returning to the rivers for reproduction. There is now reasonable hope that the coming years will see the release of sufficiently abundant numbers to boost this last world population of the species.

Partners united in a single objective: restore and protect the species
This highly encouraging result is the fruit of more than 20 years of research conducted by Cemagref with its scientific partners (University of Bordeaux I and the Freshwater Institute of Berlin), both in the wild and in captivity. This research has been aided financially by the European Union (Life Nature), the Ministry of the Environment, the Aquitaine and Poitou-Charente regions, the Charente-Maritime and Gironde departments, and the Adour-Garonne Water Agency.

Work is currently coordinated by the WWF France within a consortium grouping (in addition to the scientific organazations) public institutions of the EPIDOR basins (the Dordogne river basin), SMEAG (the Garonne river basin) and SMIDDEST (the Gironde estuary) and the CNPMEM (National Committee for Marine Fishery and Marine Fish Rearing).

Efforts have been made to raise awareness to this situation, aiming notably at preserving the habitats used by this species and at limiting accidental capture,conditions indispenable to the restoration of the population. This work has finally benefitted from the involvement of professional and institutional organazations of the maritime and continental fisheries sector, environmental protection groups, and specific groups working towards preserving sturgeons.

Maximum level of protection for the European sea sturgeon
The European sea sturgeon, Acipenser sturio, is a species that is strictly protected by several international agreements (Convention on International Trade in Endangered Species, the Bern convention) and European directives (habitat, fauna, flora, OSPAR : Convention for the protection of the Marine Environment of the North-East Atlantic). A plan for preserving the species on the European scale is being finalized under the auspices of the Bern convention. A national plan within the national strategy for biodiversity will organize actions on the national level.

Marie Signoret | alfa
Further information:
http://www.cemagref.fr/English/seven/News/07/Anglais_Communique_Presse_Esturgeons_web.pdf

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