Development and application of paleolimnological methods to assess pollution of aquatic ecosystems downstream of the Alberta oilsands

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In recent years, societal concerns have escalated over cumulative effects of rapidly-growing oilsands development on downstream ecosystems in the lower Athabasca River watershed. Based on expert-panel reports, current monitoring programs are inadequate to address the growing apprehension about releases of pollution from oilsands development via air and water. Key locations include the lower Athabasca River, Lake Athabasca, Peace-Athabasca Delta and community of Ft. Chipewyan where worries have been expressed for human and ecosystem health. Of particular concern are metals and organic pollutants. Studies of snowpack and lake sediments show that oilsands development is polluting at least a 50-km radius via the air. However, disentangling the roles of natural processes versus industrial development on contaminant supply via the Athabasca River remains a key scientific challenge, because systematic monitoring began 30 years after oilsands development. Thus, real-time measurements of pre-disturbance contaminant levels are not known and cannot be produced retroactively. Also, the river naturally erodes oil-bearing strata along >100 km of riverbank, which further confounds interpretation of existing monitoring data. The proposed research will develop and apply a scientifically-rigorous paleolimnological approach at three strategically-selected locations (Athabasca River downstream of oilsands, Peace-Athabasca Delta, lower Peace River) to provide key missing information on pre-industrial baseline levels of metal contaminants of concern carried by the Athabasca and Peace rivers. This approach, a product of 15 years of prior research, will use analyses of contaminants in sediments deposited into floodplain lakes by river floodwaters before industrial development to determine the natural range of sediment contaminant concentrations in the river, as baseline' to evaluate long-term river monitoring data for evidence of pollution by oilsands development and other human activities. A novel aspect is use of pre-disturbance sediments from flood-prone lakes to assess pollution of rivers. A key outcome will be generation of methods and data that can be used in ongoing and future river-quality monitoring to ensure there are minimal downstream cumulative effects from oilsands development. Ultimately, we aim to use the methodology to determine relative roles of natural processes versus industrial activity on contaminant levels at other rivers in Canada and elsewhere in the world where insufficient pre-impact data impede an ability to detect pollution, and to adapt the methodology for other types of contaminants (e.g., polycyclic aromatic compounds). Three PhD and 12 undergraduate students will be trained in sought-after skills in environmental assessment.