The various operations aim to restore, sustainably, a salmon population that must tend towards self-sufficiency. Since the species has completely disappeared from the basin, its restoration inevitably passes through restocking operations. The success of these operations is monitored through genetic monitoring of returning individuals and herds of hatchery broodstock. The release of juveniles up to 425,000 yearly fish from the Bergerac and Castels fish farms must allow the return of several hundred broodstocks that will naturally breed in the favourable habitats of the rivers upstream of the Dordogne basin.