Winter Dissolved Oxygen Conditions of the Whitemud River and Willow Creek Watersheds, Alberta, 2016 – 2017
Logan Redman, Nikita Lebedynski, and Jason Blackburn
We observed no clear spatial trends in overwintering DO habitat suitability in either watershed based solely on datasonde results which varied considerably among sites. One of seven datasonde sites in the Whitemud River watershed, and one of five in the Willow Creek watershed recorded DO concentrations that remained above the chronic effects threshold for aquatic life throughout the winter months. However, using combined results between YSI and datasonde DO measurements, we determined that the majority of the Whitemud River mainstem remained suitable for salmonids throughout the winter, whereas the tributaries and North Whitemud River did not, due to low DO concentrations and frozen conditions. In the Willow Creek watershed, sampling sites in upper headwater reaches tended to have suitable winter DO concentrations for salmonids wherever streams did not freeze to the bottom. We observed site-specific freezing, and variable DO concentrations in both watersheds.
Correlation was low between datasonde and YSI datasets, potentially as a result of undetected freezing/frazzle-ice conditions occurring at or on the datasonde beneath the ice surface. Establishment of sites in pre-determined deep run sections of faster flowing water instead of the slower pool habitats used in this study, may improve correlation between DO concentrations taken by YSI and datasonde methods.