Chlorophyll a and other water quality variables in lentic and lotic sections of the Cybina River

Annual research of some water quality variables was carried out at seven stations along a third order river (the Cybina River) situated in the Wielkopolska Region (mid-western Poland). Two lentic (lacustrine), two lotic (river), and two intermediate (lentic-lotic) sections were studied. Chlorophyll a increased 6.2-10.5-fold along the lentic sections (the influence of hypertrophic lakes) and decreased along the lotic sections. Similar trends were observed in the parameters of dissolved oxygen, BOD, suspended solids, and pH. Inverse trends were recorded for conductivity and the concentrations of most forms of nutrients. Changes in these parameters were less distinct and statistically insignificant along the intermediate sections.