The 1972 Sports Fisheries of Great Bear and Great Slave Lakes, Northwest Territories
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Environment Canada Environnement Canada Fisheries Service des pêches and Marine Service et des sciences de la mer The 1972 Sports Fisheries of Great Bear and Great Slave Lakes, Northwest Territories by M.R. Falk, D.V. Gillman, L.W. Dahlke Technical Report Series No. CEN/T-73-8 Resource Management Branch Central Region DEPARTMENT OF THE ENVIRONMENT FISHERIES AND MARINE SERVICE Fisheries Operations Directorate Central Region TECHNICAL REPORT SERIES No. CEN/T-73-8 THE 1972 SPORTS FISHERIES OF GREAT BEAR AND GREAT SLAVE LAKES, NORTHWEST TERRITORIES by Senior Biologist: M.R. FALK Technical Staff: D.V. GILLMAN L.W. DAHLKE Lake Management Section Resource Management Branch 1973 i ABSTRACT Creel census and biological sampling programs were carried out on the lake trout (Salvelinus namaycush) and other species of Great Bear and Great Slave Lakes, Northwest Territories. 4,386 anglers were interviewed from 6 sports fishing lodges. Information on the number and species composition of the catch retained and released was obtained. An estimated 46,897 and 25,286 kg of lake trout were harvested on Great Bear and Great Slave Lakes, respectively. 3,212 lake trout were sampled for length, weight, sex and maturity. Otoliths were removed and aged at later dates. Ages ranged from 5 to 42 years, lengths from 360 to 1,020 mm, and weight from 450 to 14,400 g. On Great Bear Lake trout first exhibited sexual maturity at age 13 (519 mm; 1,538 g) and were all sexually mature at age 22. Trout from Great Slave Lake, however, first attained sexual maturity at age 8 (490 mm; 1,253 g) and were fully mature at age 19. Sex ratio on each lake varied little from a 1:1 relationship. Growth rates differed among individual lodge samples and between Great Bear and Great Slave Lakes. All growth rates were similar until approximately 400 mm and age 6. After this age Great Slave trout exhibited larger gains in weight for a corresponding increase in length. Great Slave trout averaged 1;500 g heavier and 10 mm longer than Great Bear trout for corresponding ages beyond 6 years of age. Growth rates of trout were found to be much slower than those found in southern lakes. Comparisons were also made to other lake trout populations to determine the possible effect of the present exploitation rate. The present harvest of lake trout as trophies, fillet and angler lunches is substantial. Trout used for filleting comprised over 65 percent of the total catch. The data collected and local information sources indicate that the overall size and availability of trophy lake trout is declining due to the nature and magnitude of the present fishing harvest. In addition, all mature fish are susceptible to sports angling on the lake and the harvest is indiscriminate as to size and age. This raises a threat to the entire population because of the poor reproductive capacity and late maturation age of the stocks. The economic and conservation demands of the resource base to provide a sustained yield of lake trout can be best met by the continuance of the fishery on a trophy basis only. To ensure this, recommendations to convert the harvest primarily to trophy fish are made. Regulation changes are recommended to lower the catch and possession limits and to reduce mortality among released fish by implementing barbless hooks. Recommendations are also made to expand the creel census and sampling programs to portions of the fishery not covered and to investigate the effect of hooking mortality. ii ACKNOWLEDGEMENTS The Department is grateful to the lodge operators of the Northwest Territories who provided necessary information and cooperated in data collection for this study. Our appreciation is given for the work conducted during 1972 by the following students; L. French, M. Klassen, M. Busch, K. Callele, L. Cardinal, B. Thompson and K. Howard. C. Read and J. Favell assisted in age determinations and data analysis. Fisheries Service staff, based in Yellowknife, deserve special thanks for their involvement with the field program. iii TABLE OF CONTENTS Page Abstract.......................................................................................................................i Acknowledgements ................................................................................................... ii List of Figures ............................................................................................................ v List of Tables ...........................................................................................................viii List of Appendices. .................................................................................................... x Introduction ................................................................................................................1 Description of the Areas ............................................................................................2 Description of the Fisheries .......................................................................................8 Materials and Methods ............................................................................................13 General ..........................................................................................................13 Creel Census .................................................................................................14 Individual Lodge Harvest ...............................................................................15 Utilization of Harvest......................................................................................16 Total Lake Harvests.......................................................................................17 Fillet Study .....................................................................................................17 Results.....................................................................................................................19 A. Great Bear Lake...................................................................................19 Great Bear Lodge: Neiland Bay and Bear Island Outpost Camps......................................19 Great Bear Lake Lodge...................................................................29 Cameron Bay Lodge .......................................................................33 Great Bear Trophy Lodge ...............................................................37 Arctic Circle Lodge ..........................................................................40 Total Harvest from Great Bear Lake....................................................44 Comparison of Great Bear Lake Lodges .............................................45 iv Page B. Great Slave Lake ................................................................................. 47 Great Slave Lake Lodge ................................................................. 47 Frontier Fishing Lodge .................................................................... 57 Arctic Star Lodge............................................................................. 62 Indian Mountain Lodge ................................................................... 64 Trophy Lodge .................................................................................. 64 Total Harvest from Great Slave Lake, 1972 ........................................ 67 Comparison of Great Slave Lake Lodges............................................ 70 C. Fillet Study ........................................................................................... 70 D. Comparison of Great Bear and Great Slave Lakes.................................................................................................... 71 Discussion ............................................................................................................... 81 Summarv ................................................................................................................. 89 Recommendations................................................................................................... 91 Literature Cited ........................................................................................................ 93 Appendix.................................................................................................................. 95 v LIST OF FIGURES Page 1. Map of Great Slave Lake illustrating the sports fishing lodges........................................................................................... 3 2. Map of Great Bear Lake illustrating the sports fishing lodges........................................................................................... 6 3. Location of Great Bear Lodge, Neiland Bay Outpost Camp, showing the approximate area fished for lake trout, 1972................................................................................................. 20 4. Length-weight relationships of lake trout from three lodges on Great Bear Lake, 1972 ........................................................... 23 5. Comparison of length versus age of trout from three Great Bear Lake lodges, 1972 ................................................................ 25 6. Comparison of weight versus age of lake trout from three Great Bear Lake lodges, 1972 ................................................................ 26 7. Comparison of the age frequency distributions of lake trout from three Great Bear Lake lodges, 1972 ........................................ 27 8. Comparison of the length frequency distributions of lake trout from three Great