Dilbit toxicity

Behaviour changes in freshwater amphipods.

  • Melissa Giddy University of Lethbridge


The Alberta oil sands contain an estimated 167.2 billion barrels of bitumen, a heavy crude oil that comprises the majority of Canada’s crude oil production. Unrefined bitumen is extremely viscous compared to conventional oil, which is a fluid at atmospheric pressure and temperature, and therefore must be diluted with natural-gas condensates to create diluted bitumen or ‘dilbit’, so that it can flow through pipelines. New Canadian dilbit pipelines such as the Enbridge Northern Gateway Pipeline and the Kinder Morgan Trans Mountain Expansion Pipeline will come in close proximity to thousands of freshwater ecosystems. When dilbit is spilled, it will initially float in freshwater, but the added diluents will begin to evaporate and the remaining dilbit will combine with sediments, causing it to sink in freshwater Ongoing research is addressing the toxicity of sediment-bound dilbit to the freshwater amphipod Hyalella azteca. In this study, Hyalella azteca will be exposed to sediment bound dilbit for 96 hours and the adverse behavioural and physiological effects of dilbit will be assessed. To date, sediment bound dilbit has not been toxicologically studied. This research will address these questions and refine research techniques using dilbit and bitumen products in toxicity research using amphipods and other organisms. Not only that but addressing these issues will lead to better knowledge on how to best lead cleanup efforts in freshwater dilbit spills, saving money, time and possibly preventing environmental devastation as a result of pipeline spills.

Poster Abstracts