Lake Superior 



The major research effort on Lake Superior continues to be the respon- 

 sibility of the Fisheries Research Board of Canada under the terms of the Federal- 

 Provincial Agreement for Ontario Fisheries. Our staff continued to maintain close 

 liaison with this program and to cooperate In the lake trout rehabilitation program 

 and In the assessment of sea lamprey predatlon. 



During 1960, the Great Lakes Fisheries Commission, on which this Depart- 

 ment Is represented, completed the first application of larvlclde to lamprey 

 producing Lake Superior streams. With this achievement, the task of assessing the 

 effect of this experimental control In terms of: (a) reduced numbers of lampreys 

 and (b) Improved numbers of lake trout, becomes doubly Important. Only results 

 In these terms can provide the basis for extending control work to lakes Huron, 

 Michigan and Ontario. 



■ ; .- ..•:,••■•. :- Lake Huron ■■'■•-' ^^--^ ^^^^-^ ' '• 

 The South Bay lake trout study was concluded with the passage of the 

 last of the planted trout through the experimental fishery In 1960. The following 

 general conclusions are drawn from the project: 



At the level of sea lamprey predatlon prevailing In South 

 Bay during the 1950 decade, a self- sustaining lake trout population 

 could not be established by hatchery plantings. No females were 

 able to survive to spawning age. 



The planting of 79,000 yearlings over a six year period 

 did not provide attractive angling for lake trout In South Bay. 



The stock used for planting was from Lake Superior but 

 did not differ markedly In growth rate or behaviour from the 

 native lake trout present when the Investigation began. 



It appears feasible to re-establish a self- sustaining lake 

 trout population by stocking If the sea lamprey population can 

 be substantially reduced. 



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