Limnological Features of Cedar Lake, Manitoba

Abstract

Cedar Lake, largest lake in the Saskatchewan River system, was studied from June 14 until August 31, 1962. Twenty stations, located in the main basin of the lake, were examined during six sampling periods. These stations were located along five transects, at depths of 1.5, 3, 6, and 9 m. No thermal stratification occurred and the oxygen concentration never fell below 78% of air saturation. Total alkalinity and total dissolved solids averaged above 65 and 270 ppm, respectively.The average number of bottom organisms increased with depth, with the bulk of these being made up of spheariid clams, mayflies, chironomids, and gastropods. The number of genera also increased with depth. The standing crops determined for the six sampling periods ranged from 17.7 to 33.2 lb/acre (dry weight), with a mean value of 23.4 lb/acre. Correlations between the physical and chemical factors and the distribution of bottom fauna are examined and it is felt that the bottom type is the major factor affecting the distribution and abundance of bottom organisms in Cedar Lake. On the basis of the physical and chemical criteria, Cedar Lake may be classified as eutrophic.