Evaluation of trophic state of Lake Uluabat, Turkey.

Lake Uluabat, which is located in Marmara region, is one of the most productive lakes in Turkey. Due to concerns about potential pollution resulting from watershed sources and adjacent agricultural lands, a study of the trophic state of lake Uluabat was conducted during the period February 2003 to January 2004. Total nitrogen (TN), total phosphorus (TP), Secchi disc depth (SD) and chlorophyll a (Chl a) were analyzed monthly in order to assess the trophic state of the lake. According to calculated nutrient ratios, phosphorus was found to be the primary limiting nutrient in lake Uluabat. Carlson's trophic state index values, based on TP, SD and Chl a, indicated that lake Uluabat is an eutrophic system.