La répartition spatiale des poissons en rivière : aspects écologiques fondamentaux et implications pratiques

This paper examines from research carried out in the Belgian running waters some problems related to the spatial distribution of fish (seen at different scales from the view of geographical distribution to that of micro-habitat selection). Original results are presented on the geographical distribution of Chondrostoma nasus (L) in Belgium, the quantification of population biomass of Salmo trutta, Salmo trutta + Thymallus thymallus and Leuciscus cephalus in the river Ourthe basin and adjacent area, the occurrence and relative population density of 9 species along sucessive habitats within a 10 km reach of the River Ourthe and finally the relationship between the absolute density and biomass of Barbus barbus and the mean river depth.