Trap netting during June was extended in order to capture and tag the 

 required 1,000 walleye. Exceptional catches of black crappie and brown bullhead 

 and greater concentrations of saugers were noted. 



Gill netting of this, the largest of the five study areas, extended into 

 September. The accumulation of consistent and comparative catch and sample 

 records will be of great value in the ultimate assessment of this fishery. 



The parasitology study of the fishes was carried out for its third successive 

 year. One paper on a new species of trematode has been published by the 

 Research Branch and a final report is pending further investigation. 



Walleye angling quality was good, however, the catch of northern pike 

 decreased. Three separate creel census studies were carried out. 



Other points of interest include the taking of a lake sturgeon by two Indian 

 women — the fish weighed in excess of 230 pounds. It was marketed for about 

 $1.20 per pound in Kenora. Lake St. Clair trap nets were demonstrated to the 

 Indian fishery at Sioux Narrows both during the spring and fall fishery. A Lake 

 St. Clair commercial fisherman was hired for this purpose. The regional net section 

 from Port Arthur assisted commercial fishermen not only in fishing trap nets, but 

 in a better understanding of their use and construction. Though slow in adapting 

 to this new type of gear, good headway is being made with the more progressive 

 fishermen. 



RAINY LAKE 



This Unit, consisting of one biologist, was established in 1965 to study and 

 evaluate the fishery resources of Rainy Lake, to investigate the reports of declining 

 angling success and to provide data upon which management could 'be based. 



The Unit will continue work initiated by the Fort Frances staff and carried 

 out in conjunction with the Minnesota Department of Conservation. During this 

 earlier work, special emphasis was placed on analyzing Rainy Lake water levels 

 during walleye spawning. 



The 1965 programme gave precedence to distribution and age and growth 

 studies of walleye and whitefish. The 1966 programme will continue the work 

 initiated late in 1965, but will concentrate on the north arm of Rainy Lake. 



Special Projects 



1. WATER QUALITY TESTS 



The fertility or mineral content of water is one indication of the potential 

 fish productivity of a lake and such tests are an important aspect of the depart- 

 ment's lake survey programme. Water samples from specific lakes are collected by 

 field personnel and forwarded to the Ontario Water Resources Commission 

 laboratories for analysis relative to total alkalinity, total dissolved solids and 

 turbidity determinations. In 1965, tests were carried out on 692 water samples as 

 part of the lake survey programme. 



The detection of pollution is another aspect of the work conducted by the 

 department's field staff. When water quality is in doubt due to the presence of 

 industrial waste or effluents from sewage plants, water samples are taken and 

 forwarded to the Ontario Water Resources Commission for analysis. In 1965, 

 forty-five such samples were analysed. 



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