The International Union for Conservation of Nature (IUCN) defines as invasive alien species a species introduced outside of its natural distribution, which becomes problematic. The invasive alien species represent one of the most common threats for the biodiversity. The IdroLIFE Project foreseen the containment of the invasive alien species with a strong impact on the balance of the alpine and prealpine aquatic ecosystems, including the wels catfish, the red swamp crayfish and the black bullhead catfish (in the picture).