are also being started on techniques for economically rearing whitefish to the year- 

 ling stage in the event that it proves possible to sustain a fishery by planting fish 

 of this size. 



The lake trout research, undertaken in cooperation with New York State, is 

 an attempt to re-establish by hatchery plantings, a reproducing population of this 

 species in Lake Ontario, or, failing this, to define the factors which make this im- 

 possible. The last large-scale plantings were made in 1963 and 1964, and all 

 efforts were directed towards assessment of the growth and survival of these 

 planted trout. This assessment will continue until 1968 or possibly 1970, when 

 they can be expected to mature if they have survived. Our experimental netting 

 must be increased to provide this assessment since the whitefish fishery, which 

 assisted us greatly in this respect, has declined. 



The walleye research programme has been assessing the level of exploitation 

 of this Bay of Quinte species by both commercial fishermen and anglers. It has 

 been clearly shown that the population was very lightly cropped by the two fish- 

 eries combined, in both good and poor years. It was also shown that anglers ex- 

 ploit the walleye when they are young, two and three years of age and that the 

 harvest by commercial fishermen is of older fish. As in the case of whitefish, the 

 walleyes too have apparently failed to reproduce successfully for several consecu- 

 tive years now. This has meant that no new year classes of walleyes are growing 

 into the two and three year age and size at which they are available to sportsmen, 

 and angling has been of poor quality. This failure in reproduction has occurred in 

 spite of very low exploitation and must therefore be attributed to deterioration of 

 the environment. Bay of Quinte waters are being enriched at a very rapid rate 

 according to data provided by our Limnological research unit. 



The American eel has been a small but stable resource for the commercial 

 fishery for a number of years. Its recent increased market value has made it more 

 important. A study was initiated some four years ago to determine the effect, if 

 any, of the St. Lawrence Seaway installations on the size of the population in Lake 

 Ontario. It seems logical that these barriers might reduce the number of elvers 

 reaching Lake Ontario from the sea, and also that the number of adult eel passing 

 down the St. Lawrence might be reduced. The next stage of this research plans 

 the capture of several thousand elvers from below the barriers where they accumu^ 

 late in early summer, and their release, marked, above the barriers. This should 

 be done for four years, and the resultant population levels in Lake Ontario assessed 

 for comparison with the levels now in existence. 



The second in the series of four plantings of kokanee was made during the 

 winter and early spring. These plantings are an attempt to introduce this salmon 

 species to Lake Ontario as a new sport and commercial species. The species was 

 selected because, theoretically at least, it is expected to live in the rich open waters 

 of Lake Ontario which do not now produce any appreciable poundage of valuable 

 fish. Attempts to capture young-of-the-year kokanee from the first planting during 

 the open water season of 1965 were unsuccessful. Though this was disappointing 

 it was not altogether surprising in view of the small number per acre planted, and 

 in view of our inexperience at fishing for small fish at mid-water depths. 



A number of smaller projects dealing with white perch, smelt and other 

 species was continued. 



LAKE ERIE 



Smelt and yellow perch populations continued to provide the major exploita- 

 tion resources of Lake Erie during 1965. The continued low level of the walleye 



240 



