Ecology of Arctic Populations of Lake Trout, Salvelinus namaycush , Lake Whitefish, Coregonus clupeaformis , Arctic Char, S . alpinus , and Associated Species in Unexploited Lakes of the Canadian Northwest Territories

• Published in: Journal of the Fisheries Research Board of Canada
• Main Author: Johnson, Lionel
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1976
• Subjects: General Medicine; Arctic; Northwest Territories; Hudson Bay; Mackenzie River; Hudson; Great Bear Lake; Keyhole; Bay Lake; Namaycush Lake; Keyhole Lake; Mackenzie river
• Online Access: http://dx.doi.org/10.1139/f76-293; http://www.nrcresearchpress.com/doi/pdf/10.1139/f76-293

The available data on the fish populations of 35 lakes in the Northwest Territories are examined. The lakes range in size from Great Bear Lake (31, 156 km 2 ) to Keyhole Lake (46 ha); they are situated between lat. 60 and 75° N, east from the Mackenzie River to the west coast of Hudson Bay. Lake trout (Salvelinus namaycush) and whitefish (Coregonus clupeaformis) form the main populations of the mainland lakes and together make up to 95% of the total catch. There is a trend toward increasing importance of whitefish with decreasing severity of conditions. Most populations show a uni, bi-, or trimodal length distribution; age distributions are unimodal. No change in these distributions was observed over a large number of years in certain lakes. These populations are considered to have reached a climax condition comparable with a vegetational climax, and are therefore in equilibrium with their environment. All incoming energy is ultimately used in respiration to support a high biomass of fish.