The main topics of interest are reproduction biology and ecology, recruitment, population dynamics and early life history of rheophilic fishes, especially in large river systems. This involves studies in the laboratory (consumption, growth, energy partitioning, food and feeding relationships) and field investigations (distribution, migration, reproduction, microhabitat selection, population fluctuations). Methods involved are microrespiration, flow-channel experiments, electrofishing, mark-recapture techniques, image analysis and GIS. The aim of this work is to use the fish fauna as indicator of the ecological quality of river systems, i.e. understanding the functioning of relevant processes which govern the riverine biota.