Paleolimnological assessment of limnological change in 10 lakes from northwest Saskatchewan downwind of the Athabasca oils sands based on analysis of siliceous algae and trace metals in sediment cores.

• Published in: Hydrobiologia
• Main Authors: Laird, K., Das, B., Kingsbury, M., Moos, Melissa T., Pla-Rabes, S., Ahad, J. E., Wiltse, B., Cumming, B.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer 2013
• Subjects: Athabasca oil sands; Saskatchewan; Lake acidification; Climate change; Diatoms; Chrysophyte scales; Trace metals; Fort MacKay; Fort McMurray; Mackay
• Online Access: http://hdl.handle.net/10261/88868; https://doi.org/10.1007/s10750-013-1623-5

19 páginas, 5 figuras, 2 tablas. The extraction of bitumen from the Athabasca oil sands is rapidly expanding, and emission of sulphur and nitrogen oxides has substantially increased. To determine whether lakes downwind of this development in northwest Saskatchewan have been detrimentally impacted since development of the oil sands, a paleolimnological assessment of ten lakes was carried out. Analysis of diatom valves and inferences of diatom-inferred pH indicated that emissions have not resulted in widespread chronic acidification of acidsensitive lakes *80–250 km east and northeast of the oil sands development around Fort McMurray and Fort Mackay. However, one of the closest sites to the development indicated a slight decline in diatominferred pH, but the two next closest sites, both ofwhich had higher alkalinity, did not show any evidence of acidification. There were also no consistent trends in the concentration or flux of total or individual priority pollutants including lead, mercury, copper, zinc and vanadium. The sedimentation rates in most lakes increased since the mid-1900s, along with increased flux of both diatoms and scaled chrysophytes. Subtle changes in the species assemblages of diatoms and increased flux of diatoms and chrysophyte scales are consistent with recent climate change in this region. This project was funded by the Saskatchewan Ministry of the Environment Peer reviewed