Relationship between Walleye Stocking and Year-Class Strength in Three Minnesota Lakes

Abstract We evaluated fry and fingerling walleye Stizostedion vitreum stocking to supplement natural reproduction for 17–21 years in three west-central Minnesota lakes ranging in size from 960 to 2,363 ha. We used year-class strength as our primary indicator variable because strong walleye year-classes were necessary for angling to improve. An index of year-class strength (YCI) was estimated with a linear model based on catch-at-age data from gill nets. In each lake, YCI did not vary significantly among years with and without stocking of fry or fingerlings. The mean YCI was greatest for fry stocking in lakes Mary and Ida and for no stocking on Lake Miltona. The greater economic costs associated with fingerling stocking indicate that it is the least effective walleye management strategy on these lakes.