The lake trout experimental planting program, presently designed to test the 

 eflFect of stock source on survival, achieved another measured step forward in 1963 

 with the first of two special plantings in Lake Opeongo. This phase of lake trout 

 research was started in 1960 when it was noted that hatchery reared lake trout, 

 when planted in Lake Manitou, survived extremely well, but that trout from the 

 same lot and source failed to survive in Lake Opeongo. It was postulated that this 

 survival difference might be related to differences in water hardness between the 

 stock source lake, the hatchery, and the planting lake. In the fall of 1961, lake 

 trout eggs were collected from Lakes Opeongo, Lavieille and Simcoe, the planting 

 lake, a soft water lake and a hard water lake. Each lot of eggs was divided, one 

 half being hatched and reared in a soft water hatchery, the other being hatched 

 and reared in a hard water hatchery. All lots of trout were marked distinctively, 

 transported identically and planted almost simultaneously as yearlings in Lake 

 Opeongo. The plantings will be replicated in the spring of 1964. Then begins the 

 long wait for fish of the various lots to grow into the fishery during the next four 

 or five years, when we will be able to compare their survival rates. 



BROOK TROUT 



Because the brook trout has a shorter life span, research on this species tends 

 to yield results more quickly. Preliminary results of the first experimental plantings 

 made in the spring of 1962 were available through anglers and experimental netting 

 during 1963. The recovery of planted brook trout, assumed to be directly related 

 to survival, was 29.4 per cent in a lake where the only other species present were 

 minnows. In lakes where suckers as well as minnows were present with the planted 

 trout, the recoveries ranged from 2 to 4 per cent. In lakes where perch, pumpkin- 

 seed, bullheads, suckers and minnows were present, only 0.4 to 1.8 per cent of 

 the planted trout were recovered. These preliminary findings will be checked by 

 replicate plantings. The relationship between brook trout and the common sucker, 

 apparently so detrimental to the survival of planted brook trout, will require study 

 before it is understood. 



SMALLMOUTH BASS 



Work on smallmouth bass was again largely confined to Lake Opeongo and 

 to efforts to understand the relationship between strong bass year classes and 

 unusually warm summers. It is considered that Opeongo is typical of bass lakes in 

 the Shield area of Ontario, and that this research will be applicable to most bass 

 waters in northern Ontario. Plans to undertake research on bass in the southern 

 part of the province await funds and staff. 



WALLEYES 



Authority and funds were received at the beginning of 1963 to establish a 

 research program on walleyes. Difficulties in staff recruitment delayed initiation 

 of an active program until February 1964. Consideration has been given to the 

 problems in walleye management throughout the province. This, together with a 

 survey of the literature, has suggested that the most productive research is likely 

 to be in the field of walleye ecology. Potentially suitable lakes for this kind of 

 research are being sought with district help. 



LIMNOLOGY 



Support, financial and co-operative, was again provided to the Great Lakes 

 Institute, University of Toronto, in its program of studying the physical and 



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