Tadjan River is the habitat of two groups of fishes, Sturgeon and teleost. Research survey in this river shows that the fish species basically belong to 6 families of Cyprinidae, Mugilidae, Gobbidae, Acipenseridae, Salmonidae and Esocidae. All studies on the aquatic organisms living in this river also indicate that aquatic submerged Microphytae mainly consist of Potamogeton which are distributed between the second and the fourth stations. 34 genesis of 4 Phytoplankton phyla are identified and the Zeoplankton existing in this river belong to 4 animal classes-working on the benthos was also among the research programme of this project and at the end, 13 families were identified......