ANNUAL REPORT, 1945-46 27 



Whitefish Lake 



That portion in vicinity of Jones' Falls north of bridge and fifty feet south of 

 bridge, Township of South Crosby, County of Leeds. 



White Pine Lake 



Township of Gamble, District of Timiskaming. 



BIOLOGICAL SURVEYS 



ATLANTIC SALMON EXPERIMENT, DUFFIN CREEK SYSTEM, 

 ONTARIO COUNTY 



"This experiment, initiated in 1944, is being carried out for a twofold purpose. 

 Primarily, it is an attempt to reintroduce Atlantic salmon (Salmo salar) into Lake 

 Ontario and tributary streams and, secondly, to determine the efficiency of restocking 

 streams with hatchery raised fish. This is an excellent opportunity to do the latter 

 because here a species is being introduced which is not already present in the stream 

 system which eliminates any confusion between the introduced fish and those which 

 are the result of natural propagation. 



During June of 1944, 1945 and 1946, approximately 40,000 salmon fry were planted 

 each year. These salmon were distributed evenly over the stream system which includes 

 many types of streams. By seining, and other methods, the number of salmon present 

 in each section of the stream was estimated and from this the number which survive out 

 of a definite number planted may be calculated. 



Work to date has largely been confined to determining the salmon distribution and 

 survival in the various types of streams. This gives a good indication of the types of 

 streams preferred by salmon as it was found that some streams had few or no survivors 

 whereas others had a large number of survivors. Work is now being carried out to 

 determine what attributes a stream must have to qualify as a good salmon stream. 

 The more important factors affecting salmon distribution are light, temperature, food, 

 rate of flow, type of bottom, overhead cover, sedimentation, and the number of other 

 species present. 



An estimation of the number of salmon present in the whole stream system, 

 including the areas where none was found to survive, as of October, 1946, showed that 

 approximately 16% of the salmon planted in 1946 and 8% of those planted in 1945 

 were still present in the stream system. 



Although the experiment is still in its early stages, results thus far indicate that 

 if salmon are planted in favourable streams a large percentage will survive for at least 

 two years of stream life, at which time they are expected to descend the streams. 

 Traps are to be constructed in the stream during the spring of 1947 to determine the 

 number of descending smolts. 



It has been found that the rate of growth of these salmon parr is comparable with 

 that of the salmon of the Maritime Provinces." 



Biological surveys were carried out on: 



Pond at Hagersville. 



Pond at Simcoe. 



Lake on Golf Course at Renfrew. 



The south end of Lake Simcoe was examined with regard to a sudden mortality of 

 fish in that area. The fish affected were largely bullheads but some pike, black bass 

 and rock bass also died. Cause of the mortality was not determined but it is believed 

 that it was due to a disease of a bacterial or virus nature. 



