Page 119 Division of Research 



Speckled trout fishing was poorer in 1950 than in the previous two years, but 

 there was some indication that this decrease was due to unfavourable angling condi- 

 tions rather than to a decrease in the abundance of speckled trout. 



Lake Trout Investigation: A knowledge of the movements of lake trout from one to 

 another of the four main basins of lake Opeongo is of considerable importance from a 

 management viewpoint. Tagging studies since 1949 show a movement of lake trout up 

 the lake in the spring and down the lake in the fall. It is not yet known what per- 

 centage of the fish make this migration. Studies of lake trout spawning and water level 

 fluctuations due to the operation of the Hydro-Electric Power Commission of Ontario, 

 initiated in 1949, were continued in 1950. It was found that in Lake Opeongo a normal 

 draw-down of 2>4 feet had little effect on the spawning of lake trout. Similarly in 

 Hay Lake, where no serious water fluctuation was experienced in 1950. only slight 

 damage to spawn occurred. In Shirley Lake major water level fluctuations have con- 

 fined the lake trout to a narrow spawning bed of inferior quality, thereby interfering 

 seriously with natural reproduction. The depths at which lake trout spawn and the 

 position and extent of the spawning beds vary considerably from lake to lake. The 

 problem of lake level fluctuations and lake trout spawning should therefore be studied 

 at a local level. The development of techniques and equipment to aid in these studies 

 is under investigation. 



Speckled Trout Investigation: \'arious aspects of the life history of the speckled 

 trout have been studied since 1947 in order to obtain information which would aid in 

 the management of this important game fish. A study of the growth rate of these fish 

 from a number of lakes and streams was undertaken in 1950. Investigations of the 

 various requirements of speckled trout in lakes was continued, but the proposed aerial 

 search for spawning sites, proposed in 1949. could not be undertaken due to unfavor- 

 able weather. .Artificial spawning boxes were used by trout introduced into a small lake. 

 Further development of this device, it is hoped, will provide a means of encouraging 

 natural reproduction. 



Southern Research Station: In 1948 the Department, in co-operation with the Uni- 

 versity of Toronto, established a laboratory for experimental limnology at this station. 

 During the past year laboratory investigation of the effects of temperature and low 

 oxygen on various species of trout and other fish have been undertaken. An investiga- 

 tion of the inheritance of temperature resistance has also been started. A fish scale 

 projector, used to determine the age of fish, was in almost constant use during 1950 

 by technicians studying the rate of growth of fi.sh collected in the field. Facilities were 

 also provided for the study of the food habits of fish sent in by the field stations. 



Wildlife 



Wildlife research projects were under the direction of C. D. Fowle. 



Projects at the Wildlife Re.search Station. .Algonquin Park— 



Small Mammals: Studies of fluctuations and turn-over in small mammal populations 

 continued. A series of animals were examined for parasites, in co-operation with 

 the (Ontario Research Foundation. 



Small Bird Populations: Using the census technique developed in the past several 

 summers, the variations in density and species composition of the l)ir(l populations in 

 two distinct forest environments were studied. 



