IMPACT OF PREHISTORIC SETTLEMENTS ON THE CLADOCERA IN THE SEDIMENTS OF LAKES SUSZEK, BLEDOWO, AND SKRZETUSZEWSKIE

An analysis of Cladocera has been made on sediments from the three Polish lakes Suszek, Bledowo, and Skrzetuszeqskie. The analysed sediments are gyttja from the Subboreal and Subatlantic periods, during which the lakes were subject variously to eutrophication. The eutrophication process has been analysed from the frequency of Cladocera, particularly the index species, and has been correlated with climatic and settlement changes. It was found that in Suszek lake, in which no significant human activity had taken place (palynologically documented), the eutrophication must have been slow and gradual. On the contrary, in the two remaining lakes, in which the human influence was more intense, the eutrophication process underwent intensive changes and coincided somewhat with settlement fluctuations.