The Life History and Ecology of the Yellow Walleye, Stizostedion Vitreum, in Lac La Ronge, Saskatchewan

Abstract

The yellow walleye population of Lac la Ronge was studied from 1950 to 1956 using creel census, tagging, trapping the spawning run and extensive gill netting. Spawning runs of thirteen to thirty thousand walleyes enter the Montreal and Potato Rivers a few days after the ice leaves the rivers and small lakes but much earlier than the break-up of ice on Lac la Ronge. Maximum spawning activity was in water temperatures of 45–50°F. Males outnumber females in the run by 5 to 1. A few spawned at 5 years but the bulk of the run was 8 to 10 years old. The rate of growth of walleyes in Lac la Ronge is intermediate as compared to that recorded elsewhere in Canada and in the United States. Females grow considerably faster than males. The food was 97 percent fish with ciscoes and ninespine sticklebacks as the main items. External and internal parasites are reported. Movements of the walleye population were followed through the spawning run, gradual return to the main lake and late summer dispersal into deep water. Greater activity was demonstrated at night than during the day. Seventy percent of the recoveries were within two miles of the tagging site and only 5 percent more than 20 miles away. One walleye had gone 65 miles upstream. Tagging and other evidence suggests that the spawning runs of two rivers about 6 miles apart represent essentially discrete populations. The anglerˈs catch of walleyes, averaging 41,000 pounds per year, is of the same order as the previous commercial catch. Six years of creel census indicates that the walleyes have contributed steadily, about 17 percent of the game fish catch. The population appears quite capable of supporting present rates of utilization.