Walleye Sander vitreus are culturally and recreationally important in Wisconsin, USA and have experienced population declines in some lakes due to reduced natural recruitment. In 2013, the Wisconsin legislature implemented the Wisconsin Walleye Stocking Initiative, a statewide rehabilitation effort to help declining walleye populations through increased stockings of fall fingerling walleye (150–250 mm). Our objectives were to: (1) test for differences in natural mortality (M) of stocked walleye among stocking densities (12.4, 24.7, 37.1 fish/ha), lake recruitment status (some natural recruitment or no natural recruitment), and lake conductivity (surrogate for lake productivity); (2) estimate cost to harvestable age (i.e., age-4); and (3) compare predicted adult walleye abundance among lakes across various stocking densities in relation to Wisconsin walleye adult abundance standards (i.e., naturally reproducing population ≥7.4 adults/ha, “fishable” population ≥ 3.7 adults/ha). Fall fingerling stocked walleye M was lowest in lakes with some natural recruitment, with medium-low and high conductivities, and stocked at 24.7 and 37.1 fish/ha, respectively. Using a mixed-effects model, fall fingerling M was negatively related to stocking density but not lake recruitment status or conductivity. No conditions resulted in the naturally reproducing population density standard to be met after multiple stockings. Two to four stocking events were required to achieve the “fishable” population standard, depending on lake conditions. When estimating cost to harvestable age, lakes stocked at 24.7 fish/ha generally had the best survival resulting in the lowest cost to age-4 ($17.70 - $35.41/fish). Lakes stocked at 12.4 fish/ha had the highest cost to age-4 ($91.17 - $182.34/fish). Juvenile walleye survival from age-0 to age-1 was dependent on lake conductivity and recruitment status, with lakes stocked at 24.7 fish/ha providing the lowest cost to age-4. Our results may inform science-based decision making and best-case scenario stocking rates to increase the probability of reestablishing walleye natural recruitment.
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