Phosphorus content of bottom sediments in Swarzedzkie Lake

摘要

Phosphorus is accumulated in sediments as a result of the sedimentation of suspended matter containing this element and of its sorption on bottom sediments from the overlying water layer. Sediments are usually rich in phosphorus, especially in highly eutrophic lakes. In the surficial sediments of such lakes, phosphorus occurs mainly in the organic form, in sedi-mented plant and animal remnants (WISNIEWSKI & RZEPECKI 1996). Although plankton growth and amounts of sedimented organisms are similar throughout the lake, usually some differences in phosphorus content are observed between different parts of the lake because of local conditions, mainly due to resuspension and sediment-focusing processes, as well as to differences in external loading with tributary waters (HAKANSON & JANSSON 1983, HILTON 1985, JAMES et al. 2000, ECKERT et al. 2003). The phosphorus content of bottom sediments, as well as temperature, pH, oxygen and nitrate content, are important factors affecting internal phosphorus loading of the lake (BOSTROM et al. 1988, JENSEN & ANDERSEN 1992, NAGID et al. 2001). The aim of this study was to assess the seasonal and spatial variation in phosphorus content of bottom sediments of hyper-trophic Swarzedzkie Lake. The results were the basis for research planning of internal phosphorus loading, which is now being carried out with intact sediment cores.