Invasive Fish Species (Fauna)
Action C6 concerns the capture and removal of Silurus glanis (Wels catfish), whose presence threatens the native fish community. Silurus glanis is an allochthonous species in Italy, native to Eastern Europe (Danube basin); this fish is an exceptional predator with major impact on resident fish species.
The strong reduction of Silurus glanis could have benefits on the protection of the fish community and at the same time maintain the biodiversity of the site. The goal is to try to restore the native fish fauna as much as possible over the years, favoring some species. The action C6 aims to contain the Wels catfish population through selective fishing. As documented in the scientific literature, in limited areas a constant fishing effort determines the reduction of biomass and the number of individuals of this species.
Currently, the Silurus glanis (Wels catfish) has spread throughout Northern Italy. Well structured populations, high density and considerable growth rate indicate a tendency for further diffusion which, in compartmentalized water systems such as drainage canals, can lead to a complete imbalance of the fish community, which can be composed for more than 50% from this predator. Once the classic preys represented by Cyprinids (carp and similar species) have been exhausted, the Silurus glanis (Wels catfish) also uses other food resources such as reptiles, waterfowl and mammals. The Silurus glanis can be found both in deep channels and in basins with reduced bathymetry (<50 cm).