This occurrence dataset is derived from surveys on the ecological quality of surface water masses in Wallonia (Belgium
), performed by the Department of Study of the Natural and Agricultural Environment (DEMNA - Public Service of Wallonia).
A small part of the data can be considered as archives ('opportunistic' data coming from scattered previous projects, before the set up of the current monitoring network).
A larger part has been collected during monitorings and inventories of an evolving sites network (mainly Fishes and freshwater invertebrates).
The network was later extended in order to accomplish the activites related to the EU frawework directive for Water (2000/60/CE).
Nowadays, the permanent network is composed of 440 control sites, and is optimised to perform the activites linked to the water directive for the Wallonia. Every water masse's biological quality is reported (to Europe) every 6 years.
Control networks are based on 4 major groups of biological indicators: phytobenthos, macrophytes, Benthic invertebrate fauna and fishes.
Each of these indicator groups correspond to distinct biodiversity indice(s), that is calibrated with a standrdised sampling methods and efforts. These indices are the deliverables used for the EU reporting.
Thus, the dataset includes 4 main collections; 'MI' (MacroInvertebrates), 'PO' (Fishes), 'DT' (Diatoms) and 'MP' (Macrophytes), since they come from distinct and comparative-oriented monitoring serials.
The collections 'MI-PO1' and 'MI-PO2' correspond to field observations (for taxons that are not integrated for the biological quality index) and data beeing processed, respectively.