conditions encountered by routine management. An experimental planting schedule 

 has been designed to assess the succes of different stocking rates under these 

 conditions. The first plantings will be made in the spring of 1962. Other factors 

 to be tested will include spring versus fall planting success and the relative 

 success of speckled trout, rainbow trout and splake plantings in particular lakes. 

 The success of all plantings will be measured by creel census and by experimental 

 netting over the next several years. 



Smallmouth Bass 



Our earlier studies of smallmouth bass showed that in Lake Opeongo 

 and in South Bay of Lake Huron, strong year classes of smallmouth bass 

 occurred when summers were particularly warm. This discovery has allowed us 

 to predict the quality of angling for this species some two or three years hence. 

 Confidence in these predictions is gradually growing as it is tested annually. It 

 has been found too that predictions made for South Bay bass hold true for bass in 

 Parry Sound and in Stokes Bay. It is hoped that eventually we may reliably 

 predict angling quality over a substantial portion of the province on the basis 

 of a routine sample analysis in a single location. Such an achievement would 

 provide a substantial economy to management by eliminating the need for annual, 

 local studies. Our confidence in the predictions is growing, but will remain shaky 

 until we understand why the relationship between strong bass year classes and 

 warm summers occurs and how the factors involved operate. Studies are also 

 continuing on this matter. 



Bass populations in the central part of their range, that is in Southern 

 Ontario, do not appear to be influenced by the same factors which control year 

 class strength in the northern part of their range (South Bay and Lake Opeongo). 

 Comparable studies are being considered therefore for a typical southern Ontario 

 population. 



Plans are well in hand for research into the value of hatchery plantings 

 of bass fingerlings. 



Selective Breeding (Splake) 



This research program has the primary objective of developing a trout 

 which can live in the Great Lakes successfully whether or not sea lampreys are 

 controlled. This objective demands that the hybrid developed be able to swim 

 in the deeper waters where the cold temperatures, suitable to trout, are available, 

 and that it reproduces itself naturally before being killed by sea lamprey attack. 

 The lake trout has been particularly vulnerable to the sea lamprey predation 

 because it matured at age seven after having been available to sea lampreys for 

 at least three years. By crossing speckled trout and lake trout a pool of genetic 

 characters are provided from which, using techniques developed by our staff, 

 we hope to select and fix the desirable characters. These are (1) the deep 

 swimming ability of the lake trout and (2) the early age (two or three) maturity 

 character of the speckled trout. To achieve a strain of hybrids in which these 

 characters are fixed will require selection through several generations. Excellent 

 and promising progress was made in the work up to and including part of 1961. 

 The need for additional experimental space and water supply became clearly 

 acute during 1961 when overcrowding and disease reduced the growth rate and 

 caused serious mortalities in selected stocks. Little further progress can be 

 achieved until these facilities become available. A delay in progress has been 

 particularly unfortunate at this stage when the demand for plantings of fish in 

 Lake Huron is being keenly felt. It had been hoped that the hybrid would be 



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