Ecological Status Assessment of Batova River (Bulgaria).

The Batova Valley is protected in the sense of the requirements of the Habitats and Birds Directives and the Biodiversity Act. European environmental agency developed in the 2000 year Directive 2000/60/EC for a mutual strategy of European Council countries, for prevention and protection of waters. Criteria for assessment of surface water bodies based on hydromorphological, phisico-chemical and biological quality elemets for characterization of ecological state had addopted. In this study, two points of water collection sampling of Batova River were chosen: before and after Batovo Village, in order to assess the impact of the village on the quality of waters and the status of aquatic ecosystems. Physico-chemical parameters (pH, conductivity, dissolved oxygen, biochemical oxygen demand, ammonium, nitrate, phosphate ions) were measured and biological/benthological samples were taken. According phisico-chemical quality elements Batova River was classifided as moderate status and "not achieved good" status because of high concentration of ammonium and nitrate ions. The ecological assessment based on the leading of the lotic ecosystem biological quality element macrosoobenthos showed a high status before the Batovo Village and high according Total Number of Taxa and good status on the Biotic Index after the village. The registered less unfavorable values of the studied nutrients during the low waters periods could be attributed at one hand to the natural, active processes of decomposition of riparian vegetation fall and mineralization of the organic matter. Local anthropogenic effects like the interference caused by unauthorized discharges, landfills and diffuse sources of pollution, should not be ignored. [ABSTRACT FROM AUTHOR]