The Abundance and Distribution of Benthic Fauna of Three Mountain Reservoirs on the Kananaskis River in Alberta

Abstract

Changes in the balance of the components of benthic faunal communities are characteristic of artificially regulated aquatic environments; major alterations both of quantitative and qualitative nature occur which are most evident in the region subject to water level fluctuations, with less evident effects extending to all depths (cf. Grim'as 1961; Miller & Paetz 1959; Rawson 1958). Three artificially regulated environments were investigated during this study, Barrier Reservoir, Upper Kananaskis Lake, and Lower Kananaskis Lake; these reservoirs are located in the Rocky Mountain region of southwestern Alberta and are associated with production of hydro-electric power. The reservoirs were previously investigated (Miller 1954; Nursall 1952, 1961; Rawson 1937, 1948) and the object of the present study was to compare the distribution of the macroscopic benthic faunal communities in Upper and Lower Kananaskis Lakes with the conditions prior to regulation, and to evaluate changes in Barrier Reservoir which formerly existed as an unmodified river valley. Data were collected from 1960 to 1962 from Barrier Reservoir and in 1961 and 1962 from Upper and Lower Kananaskis Lakes. Emphasis was given to the study of Barrier Reservoir. Field records and preserved material are at the Department of Zoology, University of Alberta, Edmonton, Alberta.