Behaviour and survival of wild versus stocked fingerling walleye

Walleye Sander vitreus Mitchill have been progressively raised in hatcheries to larger sizes under the paradigm that larger stocked fish have higher survival. However, extended time in hatcheries may result in domestication, with stocked individuals lacking behaviours that promote survival. The objective of this study was to evaluate behaviour and survival of wild versus stocked fingerling (>200 mm) walleye in two Iowa reservoirs. Radio telemetry was used to evaluate walleye movement rates, depth use, home range size, habitat selection and apparent survival. Depth use increased with days since stocking and varied between lake-years but was similar between walleye groups. Daily movement rates varied by the interaction between group and day, with rates declining through time. Home ranges did not differ between groups but were significantly greater in Big Creek than Brushy Creek. Walleye in both lakes generally used habitat in proportion to availability, with few differences between groups detected. Weekly apparent survival ranged from 0.948 to 1.000, varied across lakes, years and seasons, and was higher for stocked than wild walleye in Big Creek but not Brushy Creek. The results indicate that hatchery-reared fingerling walleye behave similar to but can have higher survival than wild fish, suggesting that domestication may not be occurring and that stocking autumn fingerling walleye may help supplement year-class strength.