Grant: Collaborative Research and Development Grants

In recent years, dissolved oxygen (DO) concentration in the Athabasca River decreased below critical thresholds for aquatic organisms, due in part to point-source loading from industrial waste waters. Previously calibrated models failed to predict these low DO concentrations, indicating a knowledge gap in our current understanding of important ecosystem processes that control DO concentrations in large ice-covered rivers. The objectives of this project are (1) to gain a better understanding of the factors affecting oxygen concentration in ice-covered rivers, with a focus on sediment oxygen demand (SOD) and ice-cover ratio; (2) to improve year-round DO modeling in the Athabasca River; (3) to assess the extent and magnitude of ecological impacts from low DO events; and (4) to evaluate the effectiveness of oxygen injection as a remedy measure. A team of experts from a Canadian university, industry and government will take a multi-disciplinary approach to conduct the laboratory and field experiments and study mathematical models to achieve the project objectives. We expect the results of this project will provide participating Canadian companies with (1) a management tool that can be used to predict the impacts of biological oxygen demand and nutrient loading under variable ambient river conditions, and (2) a model to evaluate the effectiveness of oxygen injection and optimize its operation. The project will advance our understanding of the relationships between pulp mill effluents, accumulation and diagenesis in surficial sediments, and the dependence of SOD rates on these factors. The research will continue to develop innovative research capacities, pioneered at the University of Alberta in the prediction of ice cover as well as the use of microsensor and pseudo-in situ core techniques for measuring SOD rates, and to train graduate students with unique expertise relevant to managing northern rivers.