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 Yesilirmak river basin.