se 



This agreement is currently being considered for revision, in view of the progress 

 of the experiment in sea lamprey control. 



Principal research programmes are: (1) to attempt to control the sea lamprey 

 and (2) to assess the lake trout populations of Lake Superior. 



The sea lamprey control experiment has proceeded on schedule, and the 

 cond round of treatment with the larvicide T.F.M. of all lamprey producing 

 streams entering the lake was completed in 1964. The effectiveness of this second 

 treatment in reducing the lamprey population beyond its present level, awaits 

 assessment in 1965 and 1966. Plans are being made for the extension of the 

 control programme to Lake Huron. 



The lake trout population, both native and planted, continues to respond 

 well to the level of sea lamprey control achieved in the first round of treatments. 

 Some mid-lake populations which escaped full predation by sea lampreys have 

 recovered without the assistance of plantings to what are considered pre-lamprey 

 status. A limited commercial fishery has been recommended for these populations. 

 The in-shore stocks, which were decimated by predation, have been recovering 

 well with the aid in local areas of large scale plantings of lake trout yearlings. 

 These stocks have not yet reached a condition where a fishery can be recom- 

 mended. In 1964, widespread evidence of a few mature trout in spawning condi- 

 tion was noted. This is the first sign in many years of natural reproduction in 

 these in-shore areas. 



Introduction of Kokanee (land-locked salmon) 

 to the Great Lakes 



The depressed state of the fisheries, both commercial and sport, throughout 

 the Great Lakes, has been a cause of major concern to research and management 

 fisheries people for a number of years. In Lake Erie new species have become 

 important and have maintained the industry, though at a different economic level. 

 In Lake Superior, the sea lamprey control experiment offers some grounds for 

 optimism that the former fishery may be recovered. In Lakes Huron and Ontario, 

 immediate prospects for improvement are dim. A number of new species have 

 invaded the Great Lakes, e.g. sea lamprey, smelt, alewife, white perch, perhaps 

 to the detriment of the environment for traditional species. Few of these have 

 been useful. Biologists have given much thought to the consequences of deliber- 

 ately introducing new species. 



The Research Branch, after lengthy study, recommended in 1964 the intro- 

 duction of Kokanee, a land-locked variety of sockeye salmon, to Lakes Huron 

 and Ontario. The objective of the introduction was seen as the establishment 

 of a new game and commercial species. No detrimental consequences to present 

 species or to the re-establishment of formerly important species were foreseen. 



Subsequently, during 1964, some W2 million eggs from a stream-spawning 

 variety of Kokanee were obtained from British Columbia and another 1 Vi million 

 eggs from shore spawning Kokanee were obtained from the states of Montana, 

 Colorado and Washington. These have been planted, half as eyed-eggs and half 

 as "swim-up" fry, at selected sites in Lakes Huron and Ontario. Four annual 

 plantings are planned as the initial experiment to establish the species. Follow-up 

 studies to determine survival, growth, distribution and spawning success will be 

 developed during the next few years. 



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