Studies of the Fish of Great Slave Lake

• Published in: Journal of the Fisheries Research Board of Canada
• Main Author: Rawson, D. S.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1951
• Subjects: Burbot; Great Slave Lake; Longnose sucker; North Arm
• Online Access: http://dx.doi.org/10.1139/f50-014; http://www.nrcresearchpress.com/doi/pdf/10.1139/f50-014

A four-year study of the fish of Great Slave Lake was initiated one year before the lake was opened for commercial fishing. Information has been obtained about the composition, distribution and general ecology of the major species. Twenty-one species are listed and the ciscoes, probably of three species, await identification. Lake trout, common whitefish and ciscoes dominate the population and the former two species support an extensive gill-net fishery. The inconnu Stenodus, and the deepwater sculpin, Triglopsis, are of special zoogeographic interest.Sampling was mainly with standardized 300-yard gangs of gill net. In these, some 12,000 fish weighing about 20,000 pounds were taken. Some data were obtained on the selective effect of mesh size. Young and small fish were collected by seining.Great Slave Lake's area of 10,500 square miles includes a large open portion and two great arms, one to the north, the other extending eastward. Part of the north arm is shallow and its fish population is much like that of the main lake. Goldeyes, white suckers and pikeperch are found in the shallow warmer parts of these areas. None of these species are found in the deep and cold east arm, but in it grayling and round whitefish are numerous. The common whitefish is virtually absent from McLeod Bay at the extremity of the east arm.Data concerning growth in length and weight are provided for round whitefish, white sucker, longnose sucker, burbot and pikeperch. Most of these species grow a little slower in Great Slave Lake than in lakes farther south. Growth studies of five other important species have been undertaken by other workers.Analysis of the food of all the larger species shows that the main food chains are plankton→ cisco→ lake trout and plankton→ detritus→ bottom organisms→ whitefish. Pontoporeia, Mysis and cottids are important fish food in the deep water.Twenty-one species of parasites are recorded from ten species of fish.