Report of the Department of Lands and Forests for 1950 



No. 3 



Three of the fertilized lakes and one control lake were fished to determine the 

 forage fish population present and the effect on the remaining population of the 

 presence of these fish. 



As a sidelight on the fertilization problem, a study was made of incoming nu- 

 trients in the feeder streams of various lakes. This was done by analyzing water 

 samples from the streams and determining the quantity of water delivered in each. 

 Ultimately the run-off for the whole water-shed of each lake will be computed and 

 the total possible productivity in fish of each lake assessed. 



192,000 speckled trout, bass, lake trout and cisco were planted experimentally 

 in thirteen lakes and streams of the southern part of Algonquin Park. This was done 

 to determine the effect of planting and the fate of the fish so introduced. An improved 

 fish tagging system was put into effect in 1948. 



A list of lakes for closure in alternate years was compiled for the use of park 

 authorities as a means of building up the fish population. 



Fisheries — Southern Ontario 



This project, under the direction of X. S. Baldwin, was carried out in Wilmot 

 Creek to determine the brown trout population; fish movements in response to tem- 

 perature, and the effect of planting as against natural increase. 



Productivity was determined at seven pounds per acre per annum; availability 

 of fish per 100 rod hours was determined as 55 for the stream. Brown trout were 

 found to be larger than speckled trout, less predatory on fish and less vulnerable to 

 angling. 

 Fisheries — Southern Research Station 



Water analyses, stomach analyses and scale readings were carried on here on 

 samples collected at all the centres of fisheries research. The work was done by M. 

 B. Gibson, X. S. Baldwin and A. Papson. 



The Fish Laboratory at the Southern Research Station, at Maple, Ontario. 



