collection of sites with both biological and abiotic information - biological data covers all quality elements (macroinvertebrates, macrophytes, diatoms, other benthic algae, fish, and phytoplancton) - abiotic data comprises hydromorphological info (Gew�sserstrukturkartierung), physico-chemical info, and information about landcovering in catchment area primary aim was to aquire complete site information (complete set of environmental data and data from all organism groups), but finally the datasets turned out to be quite fregmentary More information on this dataset can be found in the Freshwater Metadatabase - BF_W_76-R-CAl (http://www.freshwatermetadata.eu/metadb/bf_mdb_view.php?entryID=BF_W_76-R-CAl).