Survival and behaviour of Atlantic salmon smolts passing a run‐of‐river hydropower facility with a movable bulb turbine

• Published in: Fisheries Management and Ecology
• Main Authors: Thorstad, E. B., Havn, T. B., Sæther, S. A., Heermann, L., Teichert, M. A. K., Diserud, O. H., Tambets, M., Borcherding, J., Økland, F.
• Other Authors: Ministry for Climate Protection, Environment, Agriculture, Conservation and Consumer Protection of the State of North Rhine-Westphalia (MKULNV), North Rhine-Westphalian State Agency for Nature, Environment and Consumer Protection (LANUV)
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2017
• Subjects: Atlantic salmon; Salmo salar
• Online Access: http://dx.doi.org/10.1111/fme.12216; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Ffme.12216; https://onlinelibrary.wiley.com/doi/pdf/10.1111/fme.12216

Abstract Downstream migration of radio‐tagged Atlantic salmon smolts, Salmo salar L., was studied in the Kinzig, Germany, to examine effects of passing a run‐of‐river hydropower station with a movable bulb turbine. Immediate mortality for smolts passing the power station was low (3%–6%), probably facilitated by a curved rack in front of the turbine and the possibility to pass over it. Mortality in the impounded stretch above the power station was also low (1.5% extra mortality compared to a control stretch). The combined mortality due to hydropower was 5%–8%, excluding delayed effects. Most smolts followed the main flow passing through the turbine area (94%). Only few used a fishway (4%) or a nearby millstream (2%). Migration speed was slowed down at the power station, but the passage only caused a short delay (average/median 8.6/1.3 hr). However, even low mortality and short delays at several power stations and reservoirs may have considerable cumulative effects.