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<p>Hamilton Harbour is one of the most polluted sites on the Great Lakes, affected by airborne and sedimentary contamination as a result of both heavy vehicle traffic and thousands of kilograms of industrial steel emissions. Polycyclic Aromatic Hydrocarbons (PAHs) are ubiquitous mutagenic byproducts of incomplete organic combustion; they are present at very high concentrations in the air and sediment of Hamilton Harbour. We quantified DNA mutation rates in three different nesting colonies of Double-crested Cormorants (<em>Phalacrocorax auritus</em>) using five microsatellite markers. These colonies were located at various distances from sources of PAHs and other contamination. We compared pollution-exposed and reference colonies, hypothesizing that cormorants living closest to pollution will have higher rates of germline microsatellite mutations than those living farther away from pollution sources. Using a pedigree approach, we identified mutations when chicks showed microsatellite alleles not found in either parent, and other explanations such as extra-pair parentage had been ruled out. Microsatellite mutation rates were 4.4 times higher at the Hamilton Harbour site closest to the industrial sources of PAH contamination than the other Hamilton Harbour site, and both were higher than the reference colony. Metabolites of the PAH benzo[a]pyrene in cormorant tissues from both Hamilton Harbour sites were identified by LC-MS/MS, demonstrating that cormorants in Hamilton Harbour are exposed to, and metabolizing, PAHs. Diet was not substantially different between the two Hamilton Harbour colonies when measured with regurgitated samples and fatty acid analysis. This suggests airborne pollution in Hamilton Harbour induced germline mutations in cormorants.</p> / Master of Science (MSc)

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Increasing awareness about the presence and ecological ramifications of toxic, persistent and bioaccumulative contaminants within the Great Lakes system spurred the implementation of numerous bans and emissions restrictions over the past few decades. Due to their high trophic status in food webs and the critical link they serve with human consumers, fish species have historically been monitored to assess the relative success of such remedial efforts within the region and to simultaneously ascertain the current risks posed to local humans. Using Bayesian dynamic linear modelling, this project first aimed to evaluate temporal trends of various organochlorine contaminants within Lake Erie fish communities, the results of which generally indicated decreasing trends through time. The second half of this study used a similar Bayesian approach to propose a framework for updating fish consumption advisories, with specific attention paid to the acknowledgment of uncertainty and natural variability when producing such consumption guidelines.

Increasing awareness about the presence and ecological ramifications of toxic, persistent and bioaccumulative contaminants within the Great Lakes system spurred the implementation of numerous bans and emissions restrictions over the past few decades. Due to their high trophic status in food webs and the critical link they serve with human consumers, fish species have historically been monitored to assess the relative success of such remedial efforts within the region and to simultaneously ascertain the current risks posed to local humans. Using Bayesian dynamic linear modelling, this project first aimed to evaluate temporal trends of various organochlorine contaminants within Lake Erie fish communities, the results of which generally indicated decreasing trends through time. The second half of this study used a similar Bayesian approach to propose a framework for updating fish consumption advisories, with specific attention paid to the acknowledgment of uncertainty and natural variability when producing such consumption guidelines.

For over ten years the Western Basin of Lake Erie has been plagued by significant harmful algal blooms (HABs). Lake Erie is a body of water situated between the United States of America (USA) and Canada. The lake provides water to approximately 40 million people and is a considerable source of economic value. The Western Basin of Lake Erie is highly prone to HABs due to the shallow depth and large phosphorus (P) loads received from the large area of agricultural land surrounding the lake and its tributaries. HABs cause extensive ecosystem degradation, have multiple negative health impacts, and cause significant economic losses for the tourism and fishery industries. Five products with P load reducing properties from the three nutrient control categories (biological, physical, and chemical) were chosen to determine how effective their P load reduction pathways were. Additionally, these products were analyzed to determine if they could generate positive remediation effects on the Lake Erie HAB. Of these five products, the technologies Water 3.0 and PO4 Sponge were applied to a Western Basin HAB model generated using the Stella Professional software from ISEE Systems. The two products were modeled individually and collectively to compare the application effects on the HAB model. The model results illustrate the significant reduction in P load and HAB extent that the application of these products at wastewater treatment plants (WWTPs) and within waterways could have. The application of both products at multiple locations within the model showed the greatest P load reduction and nearly eliminated the HAB extent. Unfortunately, the residual P from extensive historical P loading into the lake would prevent such a significant reduction from occurring for over a decade. Current practices and regulations in the Lake Erie Basin are not stimulating P load reductions significant enough to remediate the HAB. As the Western Basin HAB continues to occur annually, the waste stream produced by the HAB remains unutilized. Implementing new and innovative technologies in the basin can generate high quality commodity streams out of the wasted biological algal matter. Meanwhile the implementation of new technologies and practices can help reduce the HAB to a smaller size that would have smaller negative impacts to the economy, health, and ecology.

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