The main environmental objective of the European Water Framework Directive is to achieve good surface water and groundwater quality in various European water systems by 2015. Member States should make efforts and report on the progress made. For surface waters in particular, member states are obliged to develop and implement a specific ecological monitoring network. In addition, Natura 2000 species must be monitored area-wide in Flanders in implementation of the EU Habitats Directive.
The INBO fish reference network annually collects the necessary data to meet both European reporting requirements.