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Full-Text Articles in Physical Sciences and Mathematics
Effects Of Harvest Regulations And Post-Release Hooking Mortality On Walleye Populations In South Dakota, Cade Lyon
Electronic Theses and Dissertations
Harvest regulations are commonly implemented to manipulate fisheries stocks. By regulating the size and number of fish that are harvested by anglers, managers are able to meet the goals and needs of regions. However, these management actions come with the potential for negative consequences. Overexploitation due to less restrictive harvest regulations can cause collapses in fisheries populations. In addition, indirect consequences such as hooking mortality brought on by length-based regulations can also be detrimental to populations. In this study, I investigated the effects of various harvest regulations on Walleye populations in three western South Dakota irrigation reservoirs: Angostura, Belle Fourche, …
Walleye Fishery Ecology In Lake Oahe Of The Dakotas, Eli Felts
Walleye Fishery Ecology In Lake Oahe Of The Dakotas, Eli Felts
Electronic Theses and Dissertations
Walleye Sander vitreus is among the most popular sport fishes in North America and is the most sought-after fish in both South Dakota and North Dakota. Lake Oahe, a large main stem Missouri River reservoir, spans state boundaries and provides one of the most popular and productive Walleye fisheries in both Dakotas. The Walleye population of Lake Oahe has experienced wide fluctuations in abundance and size structure over the last 25 years which has caused high variability in angler use and satisfaction. Much of this variation is thought to be driven by Rainbow Smelt Osmserus mordax, which are the dominant …
Use Of High Pressure Liquid Chromatography To Detect And Quantify Oxytetracycline Marks In Walleye Otoliths And Dorsal Spines, Michael J. Hawkins
Use Of High Pressure Liquid Chromatography To Detect And Quantify Oxytetracycline Marks In Walleye Otoliths And Dorsal Spines, Michael J. Hawkins
Electronic Theses and Dissertations
Oxytetracycline (OTC) is used to chemically mark calcified structures in walleye Stizostedion vitreum fry and fingerlings. Current visual methods for detection of these marks are subjective, and biologists are unable to quantify the amount of OTC in a sample. The goal of this study was to determine if high pressure liquid chromatography (HPLC) is a feasible and superior alternative for detecting and quantifying OTC in otoliths of fry-marked and spines of fingerlingmarked walleyes. Study objectives were to validate methodology of extraction of OTC from calcified tissue, detect and quantify extracted OTC using HPLC, and determine a cost comparison of current …
Food Habits And Diet Overlap Of Age-1 And Older Walleye And White Bass In Lake Poinsett, South Dakota, Andrew B. Starostka
Food Habits And Diet Overlap Of Age-1 And Older Walleye And White Bass In Lake Poinsett, South Dakota, Andrew B. Starostka
Electronic Theses and Dissertations
White bass Marone chysops and walleye Stizostedion vitreum coexist in several of the large glacial lakes in eastern South Dakota. I collected age-1 and older white bass and walleye in Lake Poinsett, South Dakota during May, July and September, 1998 to determine food habits and diet overlap using percent by weight to describe diets and Schoener's index (Cxy) to determine diet overlap. Macroinvertebrates were common prey items for white bass in all length groups during all sample dates. The primary macroinvertebrates consumed by white bass were corixids, amphipods and dipterans. Fish, as a group, were second in diet importance over …