To determine the timing of movements and relative abundance of burbot, Lota lota, and inconnu, Stenodus leucichthys, on the lower Slave River north of the 60th parallel, we sampled on a regular basis using gillnets from June to November, 1994. Movement patterns in time and space in the Slave River and Great Slave Lake were determined by radio-tagging 24 inconnu and 16 burbot in the fall of 1994. Tracking was carried through the fall of 1994 through to July 1995.
Inconnu entered the Slave River system from Great Slave Lake in August and attained peak catch-per-unit-effort (CPUE) during the first two weeks of September. By November they had left the system. Burbot CPUE did not increase substantially, therefore, no discemable pattern of movement was recognized from catches. Radio-tagged inconnu stayed in the Fort Smith area of the river until late October when they migrated out of the system into Great Slave Lake. Migrations in Great Slave Lake appeared to be geographically extensive. From January to the end of August 1995, all inconnu were captured or detected by radio telemetry in Great Slave Lake, only. No inconnu were detected or captured in the Slave River. Extensive floy- tagging programs conducted by the Department of Fisheries and Oceans corroborate these observations for inconnu in Great Slave Lake. Burbot appeared to be relatively sedentary and probably escaped detection by residing in deep holes of the river and the river delta. These movement patterns signify that inconnu may transfer contaminants over a large area including Great Slave Lake whereas burbot would concentrate contaminants locally in the lower Slave River and its delta.