Year: 2024, 2024
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Phosphorus is the growth-limiting nutrient in freshwater environments. Dissolved organic phosphorus (DOP) refers to phosphorus within dissolved organic matter (DOM). Much of DOP is bioavailable, but it is poorly understood due to its complexity. This thesis explores the export DOP to Lake Erie from its tributaries, by investigating its speciation and concentration seasonally through… more
Year: 2023, 2023
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Brown, Rachel, Thesis advisor (ths): Aherne, Julian, Degree committee member (dgc): Koprivnjak, Jean-François, Degree committee member (dgc): Sager, Eric, Degree committee member (dgc): Lafleur, Peter, Degree granting institution (dgg): Trent University Abstract: <p>In this study, twenty lake catchments surrounding Iqaluit, Baffin Island, were assessed for trace element concentrations (Al, As, Ba, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Sb, Se, THg, V, Zn) in lake water, catchment soil, lake sediment, and moss (Hylocomium splendens). Additionally, the sources of each trace element were determined through the positive matrix factorization (PMF) model and… more
Year: 2023, 2023
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Annan, Melanie Joslyn, Thesis advisor (ths): Frost, Paul C, Degree committee member (dgc): Koprivnjak, Jean-François, Degree committee member (dgc): Bailey, Robert, Degree committee member (dgc): Raby, Graham, Degree granting institution (dgg): Trent University Abstract: <p>In situ chlorophyll sensors are beneficial for monitoring of long-term impacts of algal blooms and accessing water quality issues in bodies of water. However, more research is needed to validate their efficacy and understand how environmental conditions can influence sensor measurements. I assessed the performance of an in situ chlorophyll sensor under controlled environmental conditions… more
Year: 2022, 2022
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Maximum permitted SO2 emissions from an aluminum smelter in Kitimat, B.C., increased after modernization in 2015. An increase in acidic deposition can potentially acidify forest soils. Monitoring was conducted at two long-term soil monitoring plots at near (7 km) and far (41 km) sites downwind from the smelter. Change in soil properties was assessed between 2015 and 2018: for the near… more
Year: 2022, 2022
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The following study measured dissolved organic carbon (DOC) and total mercury (THg) concentrations in acid sensitive lakes in the Republic of Ireland. Sixty-eight upland lakes and 48 lowland lakes were sampled for DOC; the upland lakes were additionally sampled for THg. Spatial variability of DOC was explained by regional precipitation and soil organic matter. A subset of lakes was… more
Year: 2020, 2020
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Environmental and seasonal processes are important watershed drivers controlling the amount, composition, and fate of dissolved organic matter (DOM) in aquatic ecosystems. We used ten months of water samples and eight months of bioassay incubations from two </p><p>contrasting catchments (agriculture and natural, forested) to assess the effects of seasonal variability on the… more
Year: 2016, 2016
Member of: Trent University Graduate Thesis Collection
Abstract: <p>This study assesses the bioavailable metal (Cu, Ni, Zn, Pb) species in the Athabasca-Mackenzie watersheds using diffusive gradient in thin films (DGT) devices. Metal toxicity is not only based on the concentration of metal in natural waters, but also on the nature of metal species. Four main forms in aquatic systems are: free ion, inorganic species, DOM bound (humic) species and metal… more
Year: 2014, 2014
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Webster, Eva Marie, Thesis advisor (ths): Ellis, David A, Degree committee member (dgc): Harner, Tom, Degree committee member (dgc): Hintelmann, Holger, Degree committee member (dgc): Koprivnjak, Jean-François, Degree granting institution (dgg): Trent University Abstract: <p>Ionizing organic chemicals are recognized as constituting a large fraction of the organic chemicals of commerce. Many governments internationally are engaged in the time-consuming and expensive task of chemical risk assessment for the protection of human and environmental health. There are standard models that are consistently used to supplement experimental and monitoring data in such… more
Year: 2014, 2014
Member of: Trent University Graduate Thesis Collection
Abstract: <p>This thesis was designed to quantify absorbance and fluorescence characteristics of dissolved organic matter (DOM) in North Atlantic, Pacific and Arctic Oceans. DOM was described in water masses of distinct sources and formation pathways as well as in regions where environmental forcings such as deep water upwelling, enhanced biological activity and receipt of freshwater discharge were… more