Physical and Chemical Studies in Lakes of the Prince Albert Park, Saskatchewan.

Abstract

The largest of these lakes has an area of 104 sq. km. (40 sq. mi.), the deepest has a maximum of 52 and a mean depth of 21 metres. The mean annual temperature is 0.0 °C. and the lakes are frozen over for six months of the year. Thermal stratification is found in six lakes each of which has a mean depth greater than 10 metres. In these lakes the thermal cycle includes the usual period of vernal circulation, summer stagnation lasting about one month and a long period of autumn circulation usually more than two months. Winter stagnation is present in an unknown degree. Two lakes with mean depths greater than 15 metres are clearly oligotrophic with no oxygen depletion at midsummer and four lakes with mean depths of from 10 to 15 metres are eutrophic and suffer from varying degrees of bottom stagnation and oxygen depletion at mid-summer. Four other lakes with mean depths of less than 10 metres are not thermally stratified and are therefore free from summer stagnation. A special examination of the near bottom layer in Waskesiu lake indicates a microstratification in the lower metre which at some seasons has a decline in oxygen equal to that in the thermocline. Brief discussions are included of the dissolved carbon dioxide, hydrogen ion concentration, mineral and organic constituents of the water.