The large-scale movement behavior of European catfish (Silurus glanis L.) remains poorly understood, despite it being a species of interest for conservation management. We report the movement patterns of 13 native individual catfish, recorded using acoustic telemetry over 160-km estuarine habitat free of migration barriers in the Scheldt River basin (Belgium). The results show that catfish can travel vast distances of over 10 km with a seasonal pattern of fish moving the largest distances in summer. The wels catfish is often considered a relatively sedentary species
however, our results show that this is not the case in systems where they have the freedom to move over large distances. Knowledge about the large-scale movement behavior of the wels catfish can be useful for species conservation, as well as pest control. For instance, the effects of migration barriers could be (re)considered in terms of the large movement distances.