http://hdl.handle.net/1974/142 2013-05-26T08:05:20Z http://hdl.handle.net/1974/8023 Title: Relationships Between Blood Mercury Concentrations and Oxidative Stress in Phalacrocorax auritus Authors: Gibson, Laura A; Lavoie, Raphael A; Campbell, Linda M; Langlois, Valerie S Abstract: Mercury (Hg) is a widespread contaminant that has been shown to induce adverse health effects in a wide range of organisms. We explored the relationship between total blood Hg concentrations ([Hg]) and oxidative stress induction in double-crested cormorants (Phalacrocorax auritus). Cormorant blood was sampled at five sites across the Great Lakes basin, Ontario, Canada and was analyzed for total [Hg].To assess cellular stress, the expression of glutathione peroxidases 1 and 3, glutathione S- transferase µ3, superoxide dismutase 1 and heat-shock protein 70 kd-8 were measured in whole blood samples. No significant variations in mean relative gene expression were found between sites for any gene for all birds. Linear regression analyses showed a slight, significantly positive relationship between individual blood [Hg] and gpx3 expression for all birds. However, when separated by sex, there were differences. Male cormorants displayed higher blood Hg concentrations than females. Female individuals showed significant positive relationships between blood Hg concentration and expression of glutathione peroxidase 3 and glutathione S-transferase μ3. Different levels of oxidative stress experienced by males and females during the breeding season may be influencing the differential oxidative stress responses to blood [Hg] observed in this study. Overall, the results of our study suggest that Hg leads to oxidative stress in the blood of P. auritus and that this oxidative stress is mediated by upregulation of gstm3 and gpx3 expression. 2013-05-06T04:00:00Z http://hdl.handle.net/1974/8015 Title: Microbiological Indicators of Water Quality and Water Sustainability Authors: Akhuetie, Floxy Abstract: The provision of high quality, clean water is of paramount importance to both human public health and the welfare of all biodiversity. Maintaining this quality also helps to promote sustainability of water globally through programs involving public health, watershed (ecosystem) protection, water-resource management and water governance and regulation. These initiatives allow for more effective risk assessment and management of the world’s usable water supply. Pathogenic microorganisms such as bacteria, viruses and protozoa which are present in faecal-contaminated water have always been a major threat to human health. Monitoring every single pathogen present in water is impractical, therefore the use of microbial water-quality indicators has been recommended. Escherichia coli (E. coli) and Enterococcus sp. are the main microbial indicators used for assessing fresh and marine water (recreational water), respectively. E. coli testing is conducted all over the world and there are good tests readily available, but tests for Enterococcus are limited, even though these bacteria are often better indicators of faecal contamination. We are developing an Enterococcus test by adapting technology that was developed at Queen’s University for detecting E. coli and Total coliforms. Different growth media types were used and Todd-Hewitt broth (THB) was found to be the most effective media for the Enterococcus test and can be used at full strength or half strength. The test was optimized for temperature; 41oC elicited the best results. In order to promote selective Enterococcus growth, different antibiotics were administered. It was found that 6 mg / L of amikacin in half strength THB was optimal to make the THB media selective to Enterococcus in the presence of potentially interfering E. coli bacteria. This novel test will complement the tools already available for global water-quality monitoring, thereby promoting sustainable water-use, and thus enhancing the protection of the public’s health. Description: Thesis (Master, Environmental Studies) -- Queen's University, 2013-05-01 20:31:16.331 2013-05-02T04:00:00Z http://hdl.handle.net/1974/8002 Title: Assessing the probability and impact of secondary invasions of Hemimysis anomala to inland lakes of Ontario Authors: King, Meagan 2013-05-01T04:00:00Z http://hdl.handle.net/1974/7978 Title: Risk of Enbridge Northern Gateway Pipeline Project to Eulachon (Thaleichthys pacificus) Authors: Power, Helen Abstract: Eulachon, (Thaleichthys pacificus), is an anadromous species that spawns in the Kitimat River, British Columbia. The proposed Enbridge Northern Gateway Pipeline travels alongside this waterway and will put this species at risk. Eulachon are a unique species, and are important to freshwater and riparian ecosystems. Spawning runs occur at the end of winter, and they provide marine-derived nutrients that are essential to the functioning of these ecosystems. Species such as bears, gulls, eagles, and piscivorous fish all rely on eulachon for sustenance. The status of the central BC population of eulachon is “critically endangered”, with Kitimat River populations being “virtually extirpated” with fewer than 1000 members per run. Since 1992, eulachon runs of the Kitimat River have dropped substantially, and an oil spill at the most inopportune time could potentially eliminate this population. Haisla First Nations rely on eulachon runs for food, social, and ceremonial purposes. The elimination of these populations would have devastating effects on their way of life. The pipeline project puts eulachon at risk during all life stages; eulachon may be exposed as embryos incubating in the Kitimat River, as juveniles in the Kitimat Arm of the Douglas Channel, or as spawning adults running up the Douglas Channel. Should there be a tanker spill in the ocean, adult eulachon may also be exposed. There has been no research into the toxicological effects of crude oil or bitumen on eulachon during any life stage. Pink salmon (Oncorhynchus gorbuscha), Pacific herring (Clupea pallasii), and rainbow trout (Oncorhynchus mykiss) are three species that are most similar to eulachon. Toxicity of crude oil to pink salmon and Pacific herring embryos is observed at concentrations as low as 18 µg/L and 0.4 µg/L respectively. Liver lesions are observed in pink salmon juveniles exposed to ≥ 25 µg/L crude oil. Adult Pacific herring exposed to crude oil exhibit immunosuppression. Eulachon may have similar effects upon exposure to diluted bitumen. 2013-04-29T04:00:00Z