Catch and Winter Food of Lake Trout in certain Algonquin Park Lakes

Abstract

Winter catches of lake trout in the sports fishery exceeded those taken at other times of the year in some Algonquin Park lakes. The size of the fish caught was generally smaller because of the different type of gear used in winter. The winter fishing also exploited a high percentage of the immature stock.The winter diet was less varied than at other seasons and there was a high percentage of empty stomachs. Bottom feeding was negligible in most lakes, but, in some, insect larvae were taken more frequently than at any other time of the year. Plankton feeding was at a low level in winter even in those lakes which have predominantly plankton-feeding populations in summer. In these same lakes the absence of thermal barriers permitted trout to feed more frequently on fish in winter and also on a greater variety of fish species. Populations feeding on fish in summer continued to do so in winter. As the winter progressed, there was a decline in the frequency of plankton in the stomachs and an increase in fish and bottom fauna.