A1 Journal article (refereed)
Redds of brown trout in the deep channels of a hydroelectric power station (2020)

Syrjänen, J. T., Sivonen, K., Räihä, V., Kivinen, J., Sivonen, O., & Haapsalo, M. (2020). Redds of brown trout in the deep channels of a hydroelectric power station. River Research and Applications, 36(1), 183-186. https://doi.org/10.1002/rra.3568

JYU authors or editors

Publication details

All authors or editors: Syrjänen, Jukka T.; Sivonen, Kimmo; Räihä, Ville; Kivinen, Jouni; Sivonen, Olli; Haapsalo, Miska

Journal or series: River Research and Applications

ISSN: 1535-1459

eISSN: 1535-1467

Publication year: 2020

Volume: 36

Issue number: 1

Pages range: 183-186

Publisher: John Wiley & Sons Ltd.

Publication country: United Kingdom

Publication language: English

DOI: https://doi.org/10.1002/rra.3568

Publication open access: Not open

Publication channel open access:


Natural spawning redds of brown trout were surveyed for the first time in 1−6‐m deep urban channels of a hydroelectric power station (HEP) between two lakes in Finland, by scuba diving and wading. Before damming a century ago, thousands of lake migrating trout spawners ascended through the rapids to upstream spawning areas. Between 2015 and 2018, 11 trout redds were observed at depths of 250−340 cm; these may be the deepest reported in running waters. Nine redds were found at depths of 75−230 cm. The nearest redds were situated only 55 m upstream and 110 m downstream from the HEP inflow and outflow, respectively. Channel substrate and trout redds were dominated by particle size classes 32−64, 64−128, and 16−32 mm. The risk of diving in the area increased due to the high amount of litter on the riverbed. Observations of wild trout parr by local anglers provide evidence that natural spawning produces some fish in the HEP channels.

Keywords: trout; spawn; constructed environment; rapids; hydroelectric power stations

Free keywords: Finnish lake district; impounded river; scuba diving; Vaajanvirta rapids

Contributing organizations

Ministry reporting: Yes

Reporting Year: 2020

JUFO rating: 1

Last updated on 2022-19-08 at 19:42