Variation in Walleye Abundance with Lake Size and Recruitment Source

Abstract

We quantified the relationship between lake size and abundance of walleyes Stizostedion vitreum at two life stages, age 0 and adult, in 172 northern Wisconsin lakes. We also determined if the relationship varied with recruitment source (stocked or natural) in order to evaluate the current system of management. For adult walleyes, as estimated by mark–recapture in spring, abundance was linearly related to lake surface area. Age-0 walleye abundance estimated by fall electrofishing catch was also linearly related to the miles of shoreline surveyed. Lake surface area explained 59% of the variability in adult walleye abundance across lakes ranging in size from 93 to 15,300 acres. Lake surface area explained 61% of the variation in abundance of self-sustaining walleye populations and 65% of stocked populations. Walleye abundance was higher in lakes sustained by natural reproduction than in lakes sustained by stocking. These patterns in abundance based on recruitment source were also apparent at age 0. We conclude that differences in abundance between self-sustaining and stocked walleye populations in northern Wisconsin lakes may be established during the first year, possibly due in part to recruitment source.