Limnological characteristics of Canada's poorly known large lakes

Abstract

Canada holds several of the world's large lakes (⩾100 km2). Many of these lakes, apart from the largest like the Great Lakes, are almost unknown beyond their location and area. This study documents a recent compilation and analyses of some key limnological features of these lakes: drainage area, lake area, maximum and mean depth, pH, Secchi depth, and total dissolved solids. The analyses showed the relationships among these features and with their primary watershed and ecozone assignments. Lake area and maximum depth were good predictors of some of the other lake variables. Ecozone was generally a better predictor than primary watershed of regional variation in lake variables with lake area or maximum depth as a covariate scaling for lake size. To enable regional impact assessments of cumulative environmental pressures of Canada's large lakes, these predictive regression models provide a stop-gap means for estimating key lake characteristics when data are missing. However, as cumulative pressures increase, Canada needs to increase efforts to undertake limnological inventories and learn more first hand about these poorly known lakes.