Michigan Department of Natural Resources
Fisheries Research Report No.1881, 1980

Vital Statistics of the Fish Population in Manistee Lake, Kalkaska County, with Special Emphasis on Mortality and Exploitation of Stocked 15-cm Walleye Fingerlings


Percy W. Laarman


      

Abstract–Walleyes stocked as 11- to 17-cm fingerlings in Manistee Lake, Kalkaska County from 1974 to 1977, had an average total mortality rate of 74% one year subsequent to planting. The mean total annual mortality rate of age-groups II-VII native and stocked walleyes was 56% Mean total mortality rates of smallmouth bass, bluegills, pumpkinseeds, and black crappie were 60%, 66%, 72%, and 58%, respectively.

Fishing pressure was 35 angler hours per hectare in 1976, 16 in 1977, and 60 in 1978. For the same 3-year period, exploitation rate of all walleyes ranged from 3 to 35% with a mean of 17%. Eventually, an estimated 3.5% of the stocked walleyes will be harvested by anglers. Although the stocked fingerlings made a significant contribution to the walleye population in the lake, returns to the angler probably were not sufficient to justify raising the fingerlings to 15 cm prior to planting. The mean exploitation rates of smallmouthbass, bluegills, pumpkinseeds, and black crappie were 13%, 17%, 8%, and 19%, respectively.

Growth rates of all species except yellow perch exceeded the statewide average growth rates of fishes in Michigan.