Jeffrey Cederwall
Ph.D. Candidate
Biology
Queen's University
2018 - 2020
Supervisor(s): Diane Orihel
Research Project: Understanding the ecological impacts of diluted bitumen in freshwater lakes and their watersheds
Understanding how our lakes respond to human stressors is critical to both fundamental biology and to enable evidence-based environmental policies. Oil spills are one such stressor but, while public concern over the environmental impacts of oil spills to ecosystems is growing, we still lack a complete understanding of how aquatic food webs will respond following spills, partially in freshwater. To address this gap, the BOREAL (Boreal lake Oil Release Experiment by Additions to Limnocorrals) project is working to give a comprehensive picture of the fate and effects of diluted bitumen (dilbit) on a natural food web in a temperate oligotrophic lake. We simulated dilbit spills in limnocorrals—large, 10-m diameter enclosures installed into a lake—at the IISD-Experimental lakes, monitoring both the short and long-term responses. Within this collaborative project, my research is focused on the lower food, assessing diluted bitumen’s effects on the structure and function of phytoplankton and microbial communities. Preliminary analysis suggests that diluted bitumen stimulated both phytoplankton and microbial communities with responses dependant on the spill size— a larger effect when more oil was spilled. We hope to provide useful algal bioindicators of oil pollution to track ecosystem recovery and determine the extent of microbial biodegradation of diluted bitumen in freshwater environments.
Rodriguez-Gil JL, Stoyanovich S, Hanson ML, Hollebone B, Oriel DM, Palce V, Faragher R, Mirnaghi FS, Shah K, Yang Z, Black TA, Cederwall J, Mason J, Patterson S, Timlick L, Seguine JY, Blais JM. (2021) Simulating diluted bitumen spills in boreal lake limnocorrals - Part 1: Experimental design and responses of hydrocarbons, metals, and water quality parameters. Science of the Total Environment, 790: 148537.
Cederwall J, Black TA, Blais JM, Hanson ML, Hollebone BP, Palace VP, Rodriguez-Gil JL, Greer CW, Maynard C, Ortmann AC, Rooney RC, Orihel DM*. Life under an oil slick: Response of a freshwater food web to simulated spills of diluted bitumen in field mesocosms. Canadian Journal of Fisheries and Aquatic Sciences, 77(5).