Date of this Version
Kill, R. A. 2013. A population model for walleye in Nebraska irrigation reservoirs. Master's Thesis. University of Nebraska-Lincoln, Lincoln, Nebraska.
Understanding how and why fish population size changes between years is a central theme in fisheries ecology. Fishery agencies have limited time and financial resources, thus there is a need for a quantitative way to direct the limited time and financial resources so agencies can manage fisheries more efficiently. I developed a tool for fishery managers that synthesizes common population indices and evaluated the relative importance of those indices given varying uncertainty in age-0 walleye Sander vitreus survival. Under most circumstances, I determined that resources are best utilized in reducing age-0 survival uncertainty when understanding walleye population growth. I applied our model to walleye populations in irrigation reservoirs in southwest Nebraska to understand how often a strong year class must be produced to sustain walleye populations, and found that a strong year class must be produced at least once every four years at Harlan County Lake, Medicine Creek Reservoir, and Red Willow Reservoir, and once every 7 years at Swanson Reservoir. Additionally, I hypothesized the effects of increased water temperature resulting from climate change in the region, and determined that a strong year class must be produced at least once every 3 years at Harlan County Lake and Medicine Creek Reservoir, once every 2 years at Red Willow Reservoir, and once every 4 years at Swanson Reservoir to sustain walleye populations (i.e., populations had a higher risk of quasi-extinction during the climate change scenarios).
Advisor: Kevin L. Pope