Oxygen Conditions in Two Prairie Pothole Lakes During Winter Ice Cover

Abstract

Winter oxygen depletions rates (WODR) from two small southern Alberta prairie lakes were much higher than reported in 1979 for similar lakes in Manitoba. Depletion of oxygen was nonlinear, and the most appropriate regression model used a log transformation indicating that depletion was exponential. A correlation between WODR and sediment organic content was found both within and between the two lakes studied. Spatial variation in WODR indicated that whole-lake WODR based on single-point vertical profiles may be highly inaccurate. Oxygen concentrations in the water column stabilized at low (0.5–2.0 mg∙L −1 ) levels although an anoxic water layer may occur over the sediment.