Ultrasonic transmitters were surgically implanted into 50 sexually mature walleye Stizostedion vitreum vitreum (mean weight 1.9 kg) in Canton Reservoir during March 1977. The locations of these fish were determined bimontly from March through November 1977, as an indication of walleye concentration areas in the reservoir. Temperature, dissolved oxygen and pH profiles were also obtained bimonthly at 2 stations during this time. During the March spawning season walleye were all located near the riprap of the dam. The rest ofthe year the fish showed a preference for areas near submerged islands. There was also a tendency for the walleye to concentrate farther upstream along the perimeters of these islands as the year progressed. This apparent upstream movement by transmitter-equipped walleye may have been related to low dissolved oxygen concentrations near the bottom in the deeper portion of the reservoir during the summer months. However, no correlation was found between walleye locations throughout the year and the measured environmental parameters.
