A preliminary national analysis of some key characteristics of Canadian lakes

Knowledge of Canada's lakes is needed to manage environmental stresses. Lake inventory and lake feature databases were used to build a national impact assessment template and assess regional typology. There are similar to 910 400 lakes with area >= 0.1 km(2) (10 ha), 37% of the Earth's total. Lake features (number of lakes by size class, maximum depth, mean-maximum depth ratio, Secchi depth, pH, and total dissolved solids) were modeled regionally by secondary watershed (SWS) using linear regression models. Lake trout (Salvelimus namaycush) occurrence was analyzed as a cofactor to highlight regional links between lake characteristics and aquatic biota. Significant (R-2 from 0.231 to 0.492) regional models were obtained using area or maximum depth, lake trout Occurrence, and their cross products as covariates. Analyses of fitted SWS coefficients showed that ecozones were a better predictor of lake characteristics than primary watersheds. The national typology was consistent with previous regional assessments. The regional models were used to estimate the ber, area. and volume of lake trout lakes by size class and ecozone. There are similar to 66 500 lake trout lakes covering similar to 3 5 10 000 km(2) primarily on Boreal and Taiga Shield areas. Regional lake resource models will enable national assessment of stresses Such as climate change and invasive species.