Physical, chemical and algological characteristics of the Tigris river and dam lakes on the river

In this study, variations in density and composition of phytoplankton and water quality of Kralkızı, Dicle and Batman dam lakes and the Tigris River were investigated between February 2008 and January 2009. 48 taxa belonging to 8 algal divisio in the phytoplankton of Kralkızı Dam Lake, 64 taxa belonging to 8 algal divisio in the phytoplankton of Dicle Dam Lake, 60 taxa belonging to 8 algal divisio in the phytoplankton of Batman Dam Lake and 390 taxa belonging to 9 algal divisio in the phytoplankton of the Tigris River were determined. Members of Bacillariophyta, Chlorophyta and Cyanophyta constituted the dominant groups in terms of both species number and individual abundance in the phytoplankton of Kralkızı, Dicle and Batman dam lakes and Tigris River.Phytoplankton species and habitat characteristics of functional groups belonging to these species showed that Kralkızı and Dicle dam lakes had oligotrophic-mesotrophic conditions, while Batman Dam Lake had mesotrophic-eutrophic conditions.Trophic status of Kralkızı, Dicle and Batman dam lakes was mesotrophic according to mean values of secchi disc depth, total nitrogen, total phosphorus, chlorophyll a and trophic state index (TSI).Trophic status of the Tigris River was mesotrophic-eutrophic conditions according to mean values of total nitrogen and total phosphorus, while it was oligotrophic-mesotrophic conditions according to chlorophyll a.It was observed that although there weren?t important pollutant sources threatening water quality of Kralkızı, Dicle and Batman dam lakes, the Tigris River faced a serious pollution in Diyarbakır, Bismil and Cizre because of domestic sewage.