Abstract
Increasing anthropopressure affects natural ecosystems and may express itself in regional or spot contamination of water and soil environment. The quality of ground and surface waters depends to a large extent on drainage area management, where biogenic substances (i.e. nitrogen, phosphorus and potassium) are transported with surface run-offs to the environment. The article discusses results of studies on the drainage area of Lake Czolnowskie (Zachodniopomorskie Province). Studies covered physical and chemical assessment of soil conditions and water quality; additionally, fish was caught using two independent methods - gillnets and power generator (pursuant to CEN EN 14011 2003 and PN-EN 14011 2006). Results obtained confirm regular run-off of biogenic materials from the surface of farmed drainage area to Lake Czolnowskie. During the period of studies, the reservoir was exposed to i.e. reduction of water oxygen (3.56 mg/dm3) and permanently elevated level of general phosphorus (0.15-0.27 mg/dm3) and ammonium acid (0.16-0.27 mg/dm3), which degraded the quality of life for ichthyofauna inhabiting the lake.