Seasonal migrations of broad whitefish (Coregonus nasus (Pallas)) in an Arctic lake

The seasonal migrations of anadromous broad whitefish (Coregonus nasus (Pallas)) are relatively well understood, but little is known regarding the seasonal migrations and habitat use of the lacustrine form of this species. Radio telemetry was used to document the seasonal movements and identify important habitats of broad whitefish in a lake system in Canada's Northwest Territories. Radio transmitters were surgically implanted into 50 mature broad whitefish which were then relocated over a 16 month period. In the summer, broad whitefish used the shallow areas of the lakes and nearby riverine areas, presumably for feeding. In the autumn, fish migrated from the lakes into rivers where two spawning areas were identified. Following spawning, broad whitefish migrated back to the lakes to overwinter. These data provide the first comprehensive examination of the seasonal movements of the lacustrine form of this species. It is suggested that future management strategies for lower Mackenzie River system broad whitefish consider two units of conservation below that of the species level.