Fish and lamprey passage in a combined Denil and vertical slot fishway

• Published in: Fisheries Management and Ecology
• Main Authors: LAINE, KAMULA, HOOLI
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1998
• Subjects: Kemijoki; Northern Finland; Salmo salar
• Online Access: http://dx.doi.org/10.1046/j.1365-2400.1998.00077.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2400.1998.00077.x; https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2400.1998.00077.x

A fishway (fish pass), consisting of vertical slot and Denil sections, was constructed at the lowest dam on the River Kemijoki, northern Finland, in 1993. The river was one of the best salmon rivers in Europe until 1949, when the dam and the hydropower plant were completed close to the river mouth. From 1993 to 1995, nearly 1000 adult salmonids passed through the fishway despite heavy fishing below the dam. Of environmental variables measured, water temperature, headwater level, and discharge through the power plant in relation to season changes explained most of the variation in Baltic salmon, Salmo salar L., numbers. They had a minor effect on trout, Salmo trutta L. Migratory whitefish, Coregonus lavaretus (L.), entered the fishway but were not observed in its uppermost pool. River lamprey, Lampetra fluviatilis (L.), passed through the vertical slot section of the fishway after plastic bristles were fastened into the bottom of the slots.