In the meadow closer to the fish cages, total inorganic nitrogen, ammonium, chlorophyll-a concentrations and organic matter content in sediment were determined. It is relatively higher than those recorded at the control meadow. In order to test significant differences among stations, sampling periods and depths, environmental variables together with morphological characters of the both sites were analyzed by Canoco. Shoot density, adult leaf length, adult leaf surface area, and leaf area index (LAI) showed significant spatial and temporal changes. Additionally, except shoot density, the values obtained other morphological characters showed increasing trend towards deeper stations and further meadow from the cage activities. A coefficient values were relatively higher in the near cages and decreased related with depth.