Wstępna ocena poziomu stężenia mineralnych związków azotu i fosforu w wodach powierzchniowych zlewni jeziora Świdwie

An article presents results of six-month research (V–X 2012) of mineral nitrogen and phosphorus compounds on surface waters in Swidwie lake’s catchment area. In investigated water courses the concentration of nitrate nitrogen(V) classified water to I purity class and concentration of ammonium nitrogen classified most of these water-courses to II purity class. Whereas the concentration of the phosphate phosphorus(V) on the most of examined water- -courses exceeded II class limits for surface waters (especially on water courses running by built-up area). Positive influence of the Zurawie reservoir on the quality of waters flowing in to the Swidwie lake was noted. On the base of obtained results we concluded that Struga Zurawia and canal Bolkowo-Łegi leading large amounts of phosphate phosphorus to Swidwie lake. It may cause to increased process of its eutrophication. However we did not found large amounts of investigated biogenic compounds in river Gunica which flows to Swidwie lake. On Swidwie lake outflow lower concentration of phosphorus(V) what is the evidence of phosphates cumulation in the lake.