Ecological condition of water in Rega river in the area of Gryfice, Poland

Biomonitoring of the Rega River and its affluent - "Gryfice A" Canal, which are passing through Gryfice, was conducted in 2009. For this purpose six sites were chosen. Two of them were situated on the affluent of the river, and the others on the main stream of the river. All of the measurement sites were within the administrative boundary of Gryfice city. Thirty samples were taken overall. Five from each site. The analysis concerned of taxonomic affiliation, quantity and biomass of identified organisms. Based on the research results, the ecological condition of the investigated watercourses was established. In this study indices were used: TBI (Trent Biotic Index), the BMWP-PL index (Biological Monitiring Working Party which has been adapted to the Polish conditions), the EPT index (Ephemeroptera, Plectoptera, Trichoptera). The ecological condition of the watercourses oscillated between very good to satisfactory, depending on the site and indicator which were used. The best water quality, according to the indexes used, appeared on the first and second sites, where the determined state was very good. The worst results appeared at the sixth site. The dominating conditions of water on this site were moderate and poor. The lowest value of EPT index was reached on the sixth site and the highest one on the fourth site. Conducting the constant biomonitoring of the waters is necessary for describing the level of anthropopression. Also, it gives the bases for the water reclamation. It is also very important, because all countries of the European Union are obliged to reach at least good ecological state of surface water by 2015