Combining turbine blade-strike and life cycle models to assess mitigation strategies for fish passing dams

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Authors: Ferguson, John W., Ploskey, Gene R., Leonardsson, Kjell, Zabel, Richard W., Lundqvist, Hans
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 2008
• Subjects: Atlantic salmon; Salmo salar
• Online Access: http://dx.doi.org/10.1139/f08-078; http://www.nrcresearchpress.com/doi/full-xml/10.1139/F08-078; http://www.nrcresearchpress.com/doi/pdf/10.1139/F08-078

The combined model produced a tool for evaluating effects on fish populations from passage through hydropower turbines at dams. Mean blade-strike mortality was higher for adult Atlantic salmon ( Salmo salar ) and sea-run brown trout ( Salmo trutta ) (25.2%–45.3%) than for juveniles (5.3%–9.7%). Based on life cycle modeling, salmon populations in two Swedish rivers responded differently to strategies for mitigating mortality caused by fish striking turbine blades. Although population growth rates increased up to 3% and were relatively similar for both rivers, the relative increase in the number of female salmon escaping above a dam annually after 20 years when both juveniles and adults were protected was greater in the River Piteälven (68%) than in the River Vindelälven (46%) and was approximately four times greater in the River Piteälven (38% vs. 10%) when only adults were protected. These population responses were not predicted by estimates of mortality through turbines. They showed the model could be used to evaluate strategies to conserve fish populations affected by dams located in fish migratory corridors and how postspawn adults contributed to population productivity.