http://hdl.handle.net/1974/142 2013-06-18T23:25:01Z http://hdl.handle.net/1974/8066 Title: Quantitative Structure Activity Relationships for chronic toxicity of alkyl-benz[a]anthracenes to early life-stages Japanese medaka (Oryzias latipes) Authors: Morandi, Garrett; Hodson, Peter; Brown, Stephen Abstract: Polycyclic aromatic hydrocarbons (PAH) are hydrophobic environmental contaminants known to impact survival and reproduction in fish species. This study tested the toxicity of benz[a]anthracene (B[a]A) and 7-methylbenz[a]anthracene (7-MeB[a]A) to early life stages of Japanese medaka (Oryzias latipes) using the partition controlled delivery (PCD) method of exposure and the relationship between toxicity and the log of octanol- water partition coefficient (log P). The exposure method PCD provides stable exposure concentrations maintained at and below the solubility limit of test chemicals throughout chronic toxicity assays. It relies on the partitioning of the test chemical from prepared poly (dimethylsiloxane) (PDMS) films, loaded with various concentrations of chemical, to the exposure solution. Aqueous solubility limits and film: solution partition coefficients (log Kfs) were determined. The prevalence of blue sac disease (BSD) in exposed medaka embryos was used to determine median effective concentration (EC50) of the two congeners. The test chemical 7-MeB[a]A was more toxic than B[a]A, and toxicity increased with log P. These results will further contribute to models for assessing the risk of PAH mixtures as well as to our understanding of how toxicity is affected by alkylation. 2013-06-05T04:00:00Z http://hdl.handle.net/1974/8053 Title: Threats, Monitoring, and Policy to Present and Future Climate Change from Algonquin Park (Ontario, Canada) to the Adirondack Park (New York, United States) Authors: Tavenor, Samantha Abstract: Anthropogenic greenhouse gas emissions have been steadily increasing since the Industrial Revolution. The release of greenhouse gases and the results in changes in global climate have made it a challenge for parks and protected areas to respond to the potential negative impacts to ecological integrity. The predicted rate of climate change is forecasted to be faster than the rate of deglacial warming and a fragmented landscape between large protected areas further contributes to our challenges. The Algonquin to Adirondack corridor provides a corridor for flora and fauna to migrate in the face of climate change. Assessing the perceived threats, current level of monitoring and assessment, and climate change policy provides the framework to assess our preparedness to adapt to climate change on study areas within the Algonquin to Adirondack corridor. To compile data, a literature review was completed and 8 individuals representing 7 governmental and non-governmental organizations were interviewed. The findings include: 1) there are concerns that climate change is affecting study areas, however, climate change is a large problem that many areas are not financially or capacity-wise able to deal with; 2) monitoring and assessment relevant to climate change is occurring within study areas but no standardized method is utilized; 3) budget cuts for all organizations is impacting the ability to accomplish continuous data collection, however, citizen science may potentially fill this gap; 4) there are no specific climate change policies for parks and adjacent regions. The main policy recommendation based on this research is to employ an adaptive management approach to take into account the unpredictable nature of our climate future. Additionally, given the board range of climate change impacts, tackling this issue can be done quicker and more effectively when accomplished strategically and using partnerships across this region. 2013-05-30T04:00:00Z 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