Effects of regulated discharge on burbot migration
Abstract:Burbot Lota lota movement and river discharge were studied in the Kootenai River, Idaho, U.S.A. and British Columbia, Canada, downstream of Libby Dam, Montana, U.S.A. A total of 24 adult burbot with transmitters were tracked from 1994 to 2000, for analysis of a travel distance of ≥5 km in ≤10 days termed ‘stepwise movement’. Of 44 ‘stepwise movements’, significantly greater movements during pre‐spawning and spawning were observed when average daily discharges from Libby Dam were <300 m3 s−1, with a mean of 176 m3 s−1, similar to pre‐dam conditions. Burbot travelled at a greater rate during all seasons (3·36 km day−1) at discharges >300 m3 s−1(mean = 1·84 km day−1) than at discharges >300 m3 s−1 but no difference was found for the pre‐spawning and spawning period. Burbot that started ‘stepwise movements’ in low discharge conditions frequently stopped during low discharges.
Document Type: Regular Paper
Affiliations: Idaho Department of Fish and Game 2750 Kathleen Avenue, Coeur d’ Alene, Idaho 83815, U.S.A.
Publication date: May 1, 2005