Fish fauna and fisheries of large European rivers: examples from the Volga and the Danube

Abstract

Globally, multiple stressors acting on large rivers strongly influence their ecosystem functions. They do so by altering both their biodiversity and integrity, which may in turn degrade the available ecosystem services. We present the catchment characteristics and discuss different management strategies for the two longest European rivers, the Volga (3531 km) and the Danube (2850 km). Subsequently, we analyze patterns and characteristics of fish fauna of the two rivers based on a review of historical and recent fish surveys. The native fish community of the Danube is characterized by rheophilic species, whereas the Volga has a similar proportion of rheophilic and eurytopic fish, with increasing portions of rheophilic species in the Lower Volga and the Volga Delta. We analyzed the species composition of certain regions of the Volga and the Danube and found a range of 0.515–0.667 for the Jaccard distance. Our review and comparison of fish communities and fisheries between these two largest river systems in Europe indicate that the additive effects of multiple stressors cause impacts on their fish communities. Integrated management taking into account these stressors is needed in order to preserve riverine fish diversity and enhance sustainable fisheries.