Natural Resource Ecology and Management
Journal or Book Title
North American Journal of Fisheries Management
Age‐0 Walleye Sander vitreus are stocked throughout North America to maintain and supplement populations. Predation has been implicated as a factor limiting survival of stocked age‐0 Walleye; however, timing, duration, and extent of post‐stocking predation remains uncertain. Our objectives were to estimate the abundance of predators in areas adjacent to stocking locations, estimate temporal variation in the proportion of stocked age‐0 Walleye (98‐287 mm) in predator diets, and estimate the total proportion of stocked age‐0 Walleye that were consumed. Largemouth Bass Micropterus salmoides, Northern Pike Esox lucius, and adult Walleye diets were collected from East Okoboji and West Okoboji, Iowa, USA before and after age‐0 Walleye stocking and bioenergetics models were used to estimate the number of age‐0 Walleye consumed from stocking through ice‐up. During both years, Largemouth Bass had the highest densities in West Okoboji, whereas densities of all other predators was similar in East Okoboji. The highest proportions of age‐0 Walleye in predator diets (up to 1.0) generally occurred within 14 days after the most recent stocking event, with the proportion of age‐0 Walleye in predator diets decreasing thereafter. Northern Pike (0.12 ± 0.32 age‐0 Walleye per individual) had the highest mean proportion (± SD) of age‐0 Walleye in their diets followed by Largemouth Bass (0.11 ± 0.30 age‐0 Walleye per individual) and adult Walleye (0.04 ± 0.20 age‐0 Walleye per individual). At the end of 2016, the estimated proportion (± 95% confidence interval) of age‐0 Walleye consumed in East Okoboji was 0.15 (± 0.08) and 0.29 (± 0.13) in West Okoboji. At the end of 2017, the estimated proportion of age‐0 Walleye consumed was 0.47 (± 0.16) in East Okoboji and 0.64 (± 0.02) in West Okoboji. Overall, predators consumed large proportions of stocked Walleye, suggesting that alternative stocking practices should be considered.
American Fisheries Society
Grausgruber, Emily Elise and Weber, Michael John, "Using bioenergetics to estimate consumption of stocked age‐0 Walleye Sander vitreus by a suite of piscivore" (2020). Natural Resource Ecology and Management Publications. 361.
Available for download on Tuesday, September 28, 2021