The development of an ecological quality assessment and classification system for Greek running waters based on benthic macroinvertebrates

A first approach towards an integrated, macroinvertebrate based, river type specific system for the assessment and classification of the ecological quality in Greek rivers affected by nutrient enrichment is presented. This system, which was developed within the framework of the AQEM project application in Greece, is regionally adapted and integrated, since it contains a multitude of biotic and abiotic factors affecting taxa presences and abundances. The methodology applied is very promising for the application of the Water Framework Directive (WFD) in Greece. According to the AQEM project, a seasonal 'multi habitat sampling' procedure, at 45 sampling sites, scattered over three river types, was applied. In addition, a large set of hydrological, morphological, geological, biological, hydrochemical parameters and anthropogenic factors were considered. The system is based on a new, river type specific biotic metric, adapted for Greek conditions (BMG) and a new nutrient pollution metric. The developed metrics showed high correlations with each other. Hence, BMG seems to be suitable for the ecological quality assessment of Greek running waters affected by nutrients. Moreover, by applying BMG, a final classification of the rivers into five quality classes, according to the demands of the WFD, was achieved.