In Haapakoski, Iijoki, Finland's first downhill migration route for salmonids and catching equipment have been taken into use this summer. The downward migration path was implemented as part of the large-scale Iijoki migratory fish project 2020-2022. The fairway was presented to the media and the public at the opening ceremony on 22 August 2022.
“Good cooperation leads to innovative solutions. The Haapakoski downhill migration route is a unique solution, both nationally and internationally, the implementation of which has required significant research and development efforts and open-minded implementation’, Speaking at the event, the Minister for Agriculture and Forestry: Antti Kurvinen.
“We have made a tangible step forward in Haapakoski for the downward migration of migratory fish in good cooperation with the various parties involved. In the future, we will test and, based on the results, develop the downhill migration solution further. Research, interactive cooperation and step-by-step progress are also key to the concrete results of the future for the benefit of migratory fish”, says CEO of PVO-Vesivoima Oy Jani Pulli.
The downstream route of salmonid migrating juveniles (smolts) in Haapakoski consists of a downward migration channel and a guide fence. There is an accelerating flow at the beginning of the downhill migration path. The purpose is that the smolts come to the entrance of the fairway following the guide fence, detect the flow and seek the fairway attracted by it. The fish are then directed either to the catching device or through a pipe to the lower channel of the power plant to continue their migration. The first smolts entered the fairway already in the summer of 2022.
‘This summer, underwater photography was tested in the first part of the fairway. The shooting conditions are challenging, but it would seem that the shooting will provide important information in the coming years on the behaviour of fish when entering the fairway and, at the same time, on the quantities of fish.”, says Project Manager for the Iijoki migratory fish project 2020-2022 Mirko Laakkonen Regional Council of Northern Ostrobothnia.
The downhill migration route is used annually from mid-May to the end of July. The peak migration of the Smolts is assumed to occur in Iijoki at the beginning of June with a water temperature of around 10-12 °C. In the early years, smolts are intended to be directed to a catching device and transferred by a fish transport vehicle below the lowest power plant, Raasaka. If the downhill migration equipment proves to be functional and efficient enough, similar structures will be built on other Iijoki dams. This allows fish to migrate from upstream to the sea.
The actual costs of the downhill migration route were approximately EUR 1.8 million. In the Lohi Iijoki project, which will be launched in the autumn, the operation of the fairway will be further developed. The project also invests in the monitoring of fish through extensive studies.
The measures of the Iijoki migratory fish project 2020-2022 include the construction of a downward migration path for smolts to Haapakoski, the restocking of small juveniles and the over-transfer and monitoring of salmonids. The project is implemented by PVO-Vesivoima Oy, Lapland ELY Centre, Ministry of Agriculture and Forestry, Ii, Oulu, Pudasjärvi, Taivalkoski, Kuusamo, Regional Council of Northern Ostrobothnia, Iijoki Fishing Area, Metsähallitus,
North Ostrobothnia ELY Centre and Natural Resources Institute Finland. The project is coordinated by the Regional Council of Northern Ostrobothnia. The total budget of the project is approximately EUR 2.2 million.
The project has received funding from the NOUSU programme of the Ministry of Agriculture and Forestry. The programme improves the living conditions of migratory fish and aims to restore the natural reproduction of migratory fish stocks in Finland's current waters.
Additional information:
Mirko Laakkonen, Project Manager, Iijoki migratory fish project 2020-2022, Regional Council of Northern Ostrobothnia, tel. +358 40 685 4036, mirko.laakkonen(at)pohjois-pohjanmaa.fi
Jani Pulli, CEO, PVO-Vesivoima Oy, tel: 050 386 2680, jani.pulli(at)pvo.fi
