Environmental Biology of fishes 48:359–370. 1997.
© 1997KluwerAcademic Publishers.Printed in theNetherlands
Biological characteristics ofEuropean Atlantic sturgeon, Acipenser sturio,
as the basis for a restoration program in France
Patrick Williot, Eric Rochard, Gérard Castelnaud, Thierry Rouault, Rémy Brun, Mario Lepage & Pierre Elie
Cemagref, Division Aquaculture et Pêche, BP 3, 33612 Cestas, France
Received11.10.1994 Accepted8.4.1996
Key words:population structure,artificialreproduction,wildjuvenile farming,endangeredspeciesSynopsisThe European Atlantic Sturgeon,Acipensersturio,has received increasedattention in Francebecause of
populationdeclines due tooverfishing anddeterioration ofspawninggrounds. Conservation ofthisspecies
requires manyactions, includingpublicizing the necessity toprotectthisfish and itshabitats,investigations on
catches andprobablespawning grounds, and onartificialreproduction,which isstill in anexperimentalstage.
During its sealife,EuropeanAtlanticsturgeonoccurfrom the Bay of Biscay t o theBristolChannel and North
Sea.Presently, thenumber ofyoungfish in theGirondeEstuary during summertime is low and thepopulation
has a unimodal agestructure. At thetimethispaper waswritten, thelastrecorded reproduction of sturgeon in
the Gironde system occurred in 1988 (new evidence of reproduction was discovered in 1995). Growth of young
fishfrom the 1988 cohort was fasterthan thatpreviouslydetermined for others cohorts.Over ourstudy period
(1980-1994), the availability of wild broodfish declined. Successful artificial reproduction of wild-caught fe-
malesrequires an optimalphysiologicalstate; anydelay decreasestheir reproductive potential.Acclimatiza
tion ofwild-caughtjuveniles to freshwater wasmostsuccessfulwhenfishweretransported andheldupon
arrival in low salinitywater. Forsuch wild-caughtjuveniles, thefirstfood intakeusuallyoccurs severalmonths
after capture, butremainsirregular.These findingswill b eused toimproveongoingefforts torestoreA. sturio.Introduction France(Magnin1962),Portugal and Spain(Classen
1944,Gutierrez Rodriguez1962), in theAdriatic
The EuropeanAtlantic sturgeon,Acipenser sturio Sea (Holcík et al. 1989) and in the Black Sea (Anti∨ -
is a species distinctfrom the North American At- pa 1934,Ninua1976).Populations havesince de-
lantic sturgeon, A. oxyrinchus, although many bi- clined along theIberianPeninsula(Almaea 1988,
ologicalfeatures aresimilar(seeBirstein &Bemis Elvira et al.1991,Elvira &Almodovar1993),France
1997 thisvolume).Since themiddle of the 19thcen- (Castelnaud et al.1991), and theRomaniancourse
tury,populations ofA. sturiohave beendeclining, of theDanubeRiver(Bacalbaca-Dobrovici 1991,
the declineoccurringfaster in thenorthern part of 1997 thisvolume). Atpresent, weknow ofonly two
theiroverall distributionarea(Roule1922,Berg relictpopulations: one inhabits theGironde and its
1948, Magnin l959b, Kinzelbach 1987,Holcík et al.∨ tributaries, the Garonne and Dordogne rivers in
1989,Maitland &Lyle1990,Debus1995). In the France; theotheroccurs in the Rioni River basin
middle of thetwentiethcentury,EuropeanAtlantic (BlackSea) in Georgia (formerUSSR).
sturgeon existed along the southwest coast of In France,A. sturiois consideredendangered