Keywords: chlorophyll a, nutrients, phytoplankton biomass, eutrophication, Turkey, water pollution, environmental pollution, streams, nitrates, agricultural run-off, urban point discharges, eutrophication
Monitoring of phytoplankton biomass and nutrients in a polluted stream
The spatial and temporal variations in the concentrations of nutrients (NH4+, NO2−, PO43−, SiO4−) and chlorophyll a were monitored simultaneously in a slow-flowing watercourse (Saricay Stream, Turkey), which runs in a ruralurban gradient. Chlorophyll a concentrations ranged between 0.044 g l-1 and 206.15 g l-1 and, in general, the higher concentrations of chlorophyll a and ammonium were measured downstream of the raw sewage outfalls. Nitrate was by far the most abundant form of inorganic nitrogen, and its concentration ranged between 411.71 M and 87.25 M. Silicates and phosphates were always potentially limiting to biomass relative to nitrogen. Agricultural run-off and point discharges from urban sources greatly affected the chemical composition of the water in the Saricay Stream and drove the system towards eutrophication.