Experts define 'ex-situ conservation' as conservation undertaken outside the place of origin of endangered species. It is one of the oldest species conservation methods, initially used to increase populations exploited by mankind. Nowadays it allows restoring natural ecosystems, in an attempt to save threatened species that would otherwise be doomed to disappear.
In recent years, we have been witnessing the transfer of technical and scientific knowledge on the maintenance and reproduction of aquatic organisms acquired in public aquariums to 'ex-situ' conservation programmes for endangered species aimed at reintroducing animals into the wild.
These 'ex-situ' conservation programmes make sense as part of wider projects aimed at restoring the natural habitats of wild populations in the place of origin of the species, i.e., what specialists call 'in-situ conservation'.
Freshwater fish are considered one of the most threatened groups on a global scale. In Portugal, the survival of most species is threatened due to pollution phenomena, periods of drought, invasion of exotic species, and fragmentation of river ecosystems as a result of the construction of dams and mini hydroelectric plants.
This was the context behind the creation of the Project for the ex-situ Conservation of River Organisms, which has relied on the active participation of the Vasco da Gama Aquarium since the beginning. Its main objective is the maintenance and 'ex-situ' reproduction of 'critically endangered' endemic aquatic species such as the 'Boga-portuguesa', Chondrostoma lusitanicum, and the 'Ruivaco-do-Oeste', Achondrostoma occidentale.