INTERNATIONAL JOURNAL OF ENVIRONMENT AND POLLUTION, vol.29, no.4, pp.505-517, 2007 (SCI-Expanded)
The spatial and temporal variations in the concentrations of nutrients (NH4+, NO2-, PO43-, SiO3-) and chlorophyll a were monitored simultaneously in a slow-flowing watercourse (Saricay Stream, Turkey), which runs in a rural-urban gradient. Chlorophyll a concentrations ranged between 0.044 mu g l(-1) and 206.15 mu 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 mu M and 87.251 mu 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.