Response of Cladocera (Crustacea) to Neolithic settlement at Osłonki (Kujawy region, Central Poland)

Analysis of cladoceran remains was done on two cores from fossil lakes located near the Neolithic settlement site at Osłonki (Kujawy region, Poland). The cores provide records started from the Allerod and the Younger Dryas, respectively. The cladoceran remains were used to reconstruct natural and anthropogenic eutrophication and changes in water ecosystems. Both water bodies were shallow and clear-water lakes during the Late Glacial period. Since the beginning of the Holocene, climatic and biotic changes induced natural, slow and gradual eutrophication. The evidence of intensive eutrophication started with the first occurrences the pollen antl spores of crops and weeds. Human settlement caused significant changes in cladoceran species composition. The first occurrence of crop pollen was coincident with decline of plant-associated species and increase of euplanktonic taxa tolerant to high nutrient concentration.