Theses and Dissertations at Montana State University (MSU)
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Item Feasibility of walleye population suppression in Buffalo Bill Reservoir, Wyoming(Montana State University - Bozeman, College of Letters & Science, 2019) Kaus, Daniel Joseph; Chairperson, Graduate Committee: Christopher S. GuyBuffalo Bill Reservoir, Wyoming is managed as a wild Rainbow Trout Oncorhynchus mykiss and Cutthroat Trout Oncorhynchus clarkii fishery. Nonnative Walleyes Sander vitreus were discovered in 2008, and spring sampling of Walleye indicate natural recruitment and a rapidly expanding population. Walleyes pose a predation threat to the wild trout populations in Buffalo Bill Reservoir. The Wyoming Game and Fish Department (WGFD) is interested in suppressing the Walleye population using mechanical removal with electrofishing and gillnetting during the Walleye spawning period. The purpose of this study was to evaluate the population demographics of Walleyes in Buffalo Bill Reservoir. Age-structured population models were used to estimate the Walleye population growth rate for scenarios with and without Walleye removal. To inform the population models, age-specific fecundity, probability of maturity, natural mortality, and fishing mortality were estimated. Mean asymptotic population growth rate for the five scenarios were estimated as 1.22 (95% CI of 1.05 to 1.37) for no suppression, 1.18 (95% CI of 1.04 to 1.32) for electrofish exploitation, 1.04 (95% CI of 0.88 to 1.19) for gill-net exploitation, 0.91 (95% CI of 0.61 to 1.36) for angler exploitation, and 0.81 (95% CI of 0.66 to 0.96) for angler and gill-net exploitation combined. Results from the age-structured population models suggest that long-term population suppression is a viable goal, and additional gill-net effort and angler harvest incentives should be pursued. During this study the density of mature Walleyes was low, indicating that the population had not yet reached carrying capacity. Analysis of population inertia indicates that the projected abundance of the initial population vector results in a lower population size compared to projected abundance of a population with stable-age distribution. Results from this study will be used to inform cost-effective management decisions regarding the future of the recreational fishery in Buffalo Bill Reservoir. The cost per mature female removed in 2017 was $490.91 and $80.08 for electrofish and gill net removal, respectively. Future suppression efforts should be monitored using population indices of age diversity for female Walleyes.Item Population characteristics and habitat use of a developing walleye population in Canyon Ferry Reservoir, Montana(Montana State University - Bozeman, College of Letters & Science, 2000) Yerk, David BrentItem Diet overlap and habitat utilization of rainbow trout and juvenile walleye in Cooney Reservoir, Montana(Montana State University - Bozeman, College of Letters & Science, 1994) Venditti, David AllanItem Habitat selection of adult walleye (Stizostedion vitreum) in Holter Reservoir, Missouri River(Montana State University - Bozeman, College of Letters & Science, 1996) Binkley, Keith MichaelItem Effect of diet on body composition and physical ability of intensively cultured Walleye fingerlings(Montana State University - Bozeman, College of Letters & Science, 1995) Pravecek, Jay JeffreyItem The relationship of physical habitat to the distribution of northern pike and walleye in two Montana prairie streams(Montana State University - Bozeman, College of Letters & Science, 1993) Guzevich, John WilliamItem Accumulation of dietary methylmercury by walleye and white crappie in the Tongue River Reservoir, Montana(Montana State University - Bozeman, College of Agriculture, 1982) Knight, Denise ElaineItem Competition potential between sauger and walleye in non-native sympatry : historical trends and resource overlap in the middle Missouri river, Montana(Montana State University - Bozeman, College of Letters & Science, 2006) Bellgraph, Brian Joseph; Chairperson, Graduate Committee: Christopher S. GuySauger Sander canadensis populations throughout Montana and North America have exhibited declines over the past few decades. Sauger population abundance declined in the middle Missouri and Yellowstone rivers of Montana in the mid-1980s following a period of drought. Higher flows resulted in a rebound of the lower Yellowstone River population; however, the middle Missouri River population has remained at low abundance. Various factors may contribute to the reduced population abundance of sauger in the middle Missouri River, including interspecific competition with walleye Sander vitreus. Historical trend data of sauger and walleye were assessed to determine long-term trends of sauger and walleye fitness. To assess competition potential, seasonal migrations, habitat use, and diets of both species were compared in the middle Missouri River. Trophic position of sauger was also compared between the middle Missouri and Yellowstone rivers to evaluate the trophic status of sauger in sympatry and allopatry with walleye. Sauger and walleye were tracked using radio telemetry to establish and compare seasonal migrations. Habitat use was compared at three hierarchical scales, diets were collected on fish sampled using electrofishing, and diet overlap was calculated.Item Interactions among hybrid striped bass, white bass, and walleye in Harlan County Reservoir(Montana State University - Bozeman, College of Letters & Science, 2004) Olson, Nathan William; Chairperson, Graduate Committee: Christopher S. GuyWalleye Sander vitreus, white bass Morone chrysops, and hybrid striped bass M. chrysops x M. saxatilis are common top-level predators in Midwestern reservoirs. However, the ecology and interactions among these species are not well understood. Therefore, I compared the food habits, diet breadth, diet overlap, isotopic composition, vertical distribution, and vertical overlap of these species in Harlan County Reservoir, Nebraska, during the months of June through September 2002 and 2003. In addition, prey selection of hybrid striped bass for walleye and golden shiner Notemigonus crysoleucas was evaluated using feeding experiments. All three species consumed similar prey (i.e., gizzard shad Dorosoma cepedianum), and diet overlap was high during all months in both years. No species was found to have consistently higher diet breadth. Vertical distribution was similar and spatial overlap was high for white bass and hybrid striped bass in 2002, and between white bass and walleye in 2003. Stable isotope analysis indicated that all three species occupied the same trophic level, and that each predator was deriving carbon from a similar prey source. Few hybrid striped bass consumed prey during feeding experiments, thus definitive selection by hybrid striped bass for walleye and golden shiner could not be determined. This study provides the first comprehensive evaluation of these three top-level predators in a reservoir system. Although resource overlap was high among these predators, competition is not suggested or expected because resources do not appear to be limited in Harlan County Reservoir.