Thesis (Ph. D., Civil Engineering)--University of Idaho, 2007. / Major professor: Peter Goodwin. Includes bibliographical references. Also available online (PDF file) by subscription or by purchasing the individual file.

Thesis (M.S. in food science)--Washington State University, May 2009. / Title from PDF title page (viewed on July 28, 2009). "School of Food Science." Includes bibliographical references.

Thesis (Ph.D.)--University of Idaho, June 2006. / Major professor: Kenneth D. Cain. Includes bibliographical references. Also available online in PDF format.

Thesis (M.S.)--Montana State University--Bozeman, 2008. / Typescript. Chairperson, Graduate Committee: Christopher S. Guy. Includes bibliographical references (leaves 46-50).

Nuclear microsatellite DNA and mitochondrial DNA variation were examined in coho salmon (Oncorhynchus kisutch) and white sturgeon (Acipenser transmontanus) populations in order to address conservation issues in each species. In coho the goal was to examine genetic structure on a broad scale, in order to facilitate the conservation of genetic resources within the species. Coho salmon were widely sampled across their North American range. In white sturgeon the goal was to characterize population structure within the Fraser River, in order to identify biologically meaningful management units within that system. White sturgeon sampling was restricted to two watersheds (the Fraser and Columbia rivers), allowing much more thorough sampling than was done for coho. For both species, the use of mitochondrial and nuclear markers proved advantageous over examining either marker alone. The coho data revealed two levels of intraspecific variation, and gave the best indication to date regarding how genetic resources might be distributed within this species. The data is useful for protecting this species' ability to evolve. In contrast, the sturgeon data identified four regions within the Fraser River between which migration is limited. The sturgeon data, therefore, facilitate prevention of extirpation of local populations within the Fraser River. / Graduate

There is concern regarding exposure of aquatic organisms to chemicals that interfere with the endocrine system. Disruption of the endocrine system can lead to impacts on sexual development, altered hormone levels, intersex, and ultimately reproductive failure. While effects of endocrine disrupting chemicals (EDCs) on standard laboratory species have been subject of intense study, to this day there is a large gap in knowledge and a high degree of uncertainty regarding the sensitivity of wild fish species to these compounds. One of the main concerns with current toxicity testing approaches is that they require the use of a large number of live animals, particularly when working with native species. Therefore, the aim of this study was to develop in vitro tissue explant assays that would enable the assessment of the sensitivity of different wild fish species native to North America to the exposure with EDCs. Specifically, two in vitro assays were developed: 1) A liver explant assay to assess effects of EDCs that can interact with the estrogen receptor (environmental estrogens), and 2) a gonadal explant assay to assess effects of EDCs on sex-steroid production. The test species selected were northern pike (Esox lucius), walleye (Sander vitreus), and white sucker (Catostomus commersoni) that were sampled from Lake Diefenbaker, Saskatchewan, Canada, and white sturgeon (Acipenser transmontanus) that were randomly selected from an in house stock reared from eggs. Liver tissue was excised from male fishes and exposed for 24 h to a synthetic estrogen, 17α- ethinylestradiol (EE2). Transcript abundance of vitellogenin (VTG), estrogen receptor (ER) α and β in liver tissue were quantified using qPCR. Gonad tissue from both male and female were excised and exposed for 24 h to a model inducer (forskolin) and inhibitor (prochloraz) of steroidogenesis. 11-ketotestosterone (11-KT) and estradiol (E2) were quantified in media by use of ELISA. Exposure to EE2 resulted in a concentration dependent increase in VTG in all species, and an increase in ERα in northern pike. Walleye males showed the greatest sensitivity to EE2. Gonad tissues exposed to forskolin showed a concentration dependent increase in 11-KT and E2. Exposure to prochloraz resulted in a decrease of 11-KTand E2. Male and female white sucker showed greatest sensitivity to forskolin, while male and female walleye showed greatest sensitivity to prochloraz. The seasonal time point during which gonad explants were excised and exposed had an impact on the potency and magnitude of response, resulting in a seasonal effect on sensitivity. Also, gonad explants from these species were found to have greater sensitivity than responses previously reported for in vitro explants of other fish species such as the fathead minnow (Pimephales promelas), and stable cell lines currently used as screening applications to detect chemicals that might disrupt the endocrine system. Therefore, current approaches that use stable cell lines or tissue explants from standardized small bodied laboratory species might not be protective of some wild fish species. These tissue explants represent a promising approach to help understand species sensitivity to EDCs, and if appropriately validated, could be a powerful tool for chemical screening.