THE DAM EFFECTS ON THE DISTRIBUTIONS OF FISH ASSEMBLAGES AND WATER QUALITY ON THE RIVER YESILIRMAK (TURKEY) USING PRINCIPLE COMPONENT ANALYSIS

There are multiple effects of human induced like dams on river ecosystems. Transforming the river into a lake, dams interrupt the continuity of river flow to downstream, affecting the water quality as well as biodiversity and behavior of the species in the river stretch below the dam. There can be an environmental filter through which only the species exhibiting strategies adapted to the new environment. In order to pass through environmental filter fish must be adapted to, or they must be able to change their behavior according to hydrological changes in the new environment. Otherwise, they have to migrate to an appropriate medium if they find on the river. A similar situation arises when two different dams (Suat Ugurlu and Hasan Ugurlu Dam Reservoirs) are built on the river in Yeşilırmak river basin. The aim of this study was to determine hydrological effects on fish population and the water quality of the River Yeşilırmak (Turkey). In the study, an assessment of water quality varieties between lotic and lentic habitats on Yeşilırmak River (Turkey) is presented. Seasonal samples were taken from April 2008 to July 2009 at 9 sampling sites of riverine and dam lakes built on the river. According to the results of analysis of some water quality parameters; water depth, turbidity, current speed, chlorophyll-a and nutrients of water significantly varied between dam and river sections of Yeşilırmak. Existence of dams have clearly formed spatial differences between river and lakes in terms of fish species. On the other hand, water quality data indicated that river and dam lake water had water quality classes ranging from 1 to 3. It seemed that intensive agricultural, industrial and anthropogenic activities could be responsible for creating this variability in water class level.