14 DEPARTMENT OF GAME AND FISHERIES No. 9 



has shown that the brown trout become predominant, eventually, and replace brooks. 

 They not only compete with brooks for food, but they spawn about the same time 

 and are known to monopolize the spawning beds. 



The lower reaches of many streams in southern Ontario do not possess suitable 

 conditions for speckled trout. The headwaters of some of these streams, still pro- 

 vide suitable conditions for a limited number of small trout, but, on the whole, they 

 could be more profitably stocked with browns. After careful survey and selection, 

 a number of promising streams have been stocked in old Ontario and favourable 

 reports have been received on some of these. 



Brown trout are much more notional in their feeding habits than our native 

 trout and hence are not so easily taken. They are considered a night feeder, and 

 probably the best catches are made about dark, although there are many excep- 

 tions and good catches have been made during the day time. In view of the diflB- 

 culties experienced in catching brown trout, they withstand heavy fishing pressure, 

 and hence are valuable for re-stocking waters in populated areas. 



There are several examples which testify to the fact that brown trout will live 

 in lakes, but on account of the diflftculty of capture in such an environment, from the 

 standpoint of sport fishing, re-stocking seems impracticable. However, for the pur- 

 pose of establishing natural sources of supply for brown trout eggs, the introduction 

 to suitable and controlled areas is worth a trial. This was the Department's objec- 

 tive in re-stocking Brewer Lake, in Algonquin Park, as noted in the report of the 

 Department for 1934. 



A biological study of the lake was first carried out by setting test gill nets, 

 etc., to determine the inhabitants of the lake, their relative abundance and their 

 feeding habits. The lake was then intensively netted for mature trout, predatory 

 and competitive fish. The catch was chiefly comprised of lake trout, speckled trout, 

 suckers and ling. When the netting was completed, the outlet of the lake was suit- 

 ably screened off and brown trout introduced. In addition to favourable biological 

 features, the lake is also accessible and easily controlled. 



RAINBOW TROUT: 



A study similar to that conducted for brown trout was made on Costello Lake, 

 located Immediately below Brewer Lake and Into which Brewer Lake drains. After 

 screening the outlet, rainbow trout yearlings were planted directly Into suitable 

 parts of the lake and fingerllngs were planted In the stream connecting Brewer 

 and Costello. 



The object of this work Is to establish. If possible, a source of supply for col- 

 lecting spawn In order to overcome the expense Incurred In retaining domesticated 

 stock In ponds. 



The rainbow trout distributed In our waters show a strong migratory instinct 

 to drop down to larger waters while they are yet Immature. In this way they 

 become lost to the stream In which they were originally planted, except during their 

 return for spawning purposes. During the year fingerllngs have been distributed 

 in ponds, lakes and streams where the best possible results may be obtained. Care 

 was taken to plant the rainbows In waters where spawning facilities were available 

 and tributary to larger suitable waters. 



As an Illustration of some success of the Introduction of rainbow trout, may 

 we quote the result of planting rainbow trout fingerllngs in Burnt Lake, Townships 

 of Sherbourne and McCllntock, District of Hallburton, In 1932: 



