The Geneva Tribune reports that catfish have colonized the Rhone river and Lake Geneva. It is unclear how much of a pest they really are and if they attack other fish. The local authorities have asked fishermen to kill them when they are caught, but it appears the fishermen do not want to either because they view them as beautiful creatures or that it creates a big bloody mess.
Fishermen are prohibited from selling fish caught in the lake so there is no financial incentive to kill them. According to the article catfish taste good smoked, so maybe about time to change the regulations so that fisherman can supply local food companies to smoke the fish and at the same time remove an invasive species from the lake.