SEASONAL CHANGES IN THE ACCUMULATION OF NUTRIENTS IN THE HYDROSPHERE-ATMOSPHERE INTERFACE OF URBAN PONDS (SŁUPSK, NORTHERN POLAND)

Seasonal changes were investigated in concentrations of biogenic substances in the surface microlayer and subsurface water in ponds in the city of Slupsk (Northern Poland). Water samples from the surface microlayer were collected using the Garrett screen. Those water samples were analysed to determine concentrations of nitrogen and phosphorus compounds. It was found that biogenic substances are accumulated in the surface microlayer to a greater extent than in the subsurface water layer. This accumulation is subjected to seasonal changes. The source of the analysed nitrogen and phosphorus compounds in the surface microlayer was connected with their concentration in subsurface water. Key words: pond, surface microlayer, nutrients, seasonal changes