In this document we report about the surveys performed within the framework of the freshwater monitoring network. We assessed the fish assemblages in 149 sites in nine different river basins. Among the rivers we fished in the Dijle , the Leie and the Zenne . Fish assemblage data were obtained by electrofishing using a 5 kW generator with an adjustable output voltage of 300 to 500 V and a pulse frequency of 480 Hz. The number of electric fishing devices and the number of hand-held anodes used was 2 except when the river was smaller than 1 m. We sampled also fish using double fyke nets (type 120/80). Fish data recorded included speciesspecific fish densities, individual total lengths (TL) and wet weights (g). On each site we recorded different abiotic parameters. We give for each river basin the results of the fishing campaigns. In the River Dijle basin we surveyed the Dijle and some of its tributaries. The ecological quality of the River Dijle downstream Leuven improved compared to previous campaigns. The upstream locations have a better quality but in general we observe a positive evolution in the fish population. For the first time fish was caught in the River Zenne which is rather a remarkable result since this river had a reputation as an open sewer for years and is only recently purified. In the other tributaries we could only observe an improvement in the Voer. In average the sites in the River Dijle basin have a poor quality. In the River Demer basin we surveyed two tributaries each of them showing a decrease in water quality which is reflected in a poor score for the index of biotic integrity (IBI). In the River Nete Basin and River Maas basin we could not see a change of quality compared to previous surveys. Most of the locations score a moderate quality. 25% of the assessed sites in the River Maas basin have a good quality. In the River IJzer basin a positive trend was observed but the IBI still scores poor in most sites. A similar trend is observed for the water courses within the Gentse Kanalen which ...