Modelling Winter Oxygen Depletion Rates in Ice-Covered Temperate Zone Lakes in Canada

Abstract

Winter oxygen depletion rates (WODR) (g O2∙m−2∙d−1) were determined for 13 lakes in central Alberta during the winter of 1982–83. Although dissolved oxygen decreased in all lakes for the first 3.5 mo after freeze-up, the decreases were nonlinear. The highest WODR were observed just after freeze-up. The nonlinear WODR were significantly correlated with two estimates of lake productivity (i.e. total phosphorus and chlorophyll a, P < 0.05) but were not significantly correlated with morphometry (e.g. mean depth). When the WODR from the Albertan lakes were treated as linear, to enable a comparison with other studies, correlations were found between WODR and morphometry, and WODR and estimates of summer productivity. These relationships were significantly different from observations by previous investigators who worked on ice-covered lakes in two other regions. When data from other ice-covered lakes were combined with this study, WODR were best predicted from a combination of mean summer TP (TPsu in mg∙m−2) in the euphotic zone and mean depth ([Formula: see text] in m):[Formula: see text]The above equation permits the prediction of WODR for a greater range of lake types than previous models.