Fish restocking as part of environmental responsibility
Each year, we plant a significant number of salmon, trout, and young whitefish in the waters up and downstream from the power plant. Whitefish eggs are also harvested at the Merikoski power plant and, in the autumn, lampreys are caught and moved past the power plant to spawn in the River Oulujoki.
Annual obligatory restocking volumes
- 26,200 Atlantic salmon hatchlings, at least 14 cm in length
- 4,550 sea trout, at least 20 cm in length
- 13 million newly-hatched whitefish
- 50,000 lampreys
- 3,800 kg of mature rainbow trout
- Annual costs EUR 150,000
The power plant provides a framework for the harvesting of roe
The Merikoski power plant hatchery is lively in autumn when it is time to harvest the whitefish eggs. The roe is obtained by catching female whitefish in autumn from the waters below Merikoski. The harvested roe is fertilised with the milt of a male whitefish and transferred to the hatchery of the Montta fish farm to develop. Millions of whitefish usually hatch around Labour Day in early May. Some of the young fish are introduced into the stock as hatchlings, and some are moved to natural feeding ponds for further rearing.
Restoration project of the Hupisaaret streams
The restoration of the Hupisaaret streams of the River Oulujoki delta started in the summer of 2017. The aim of the project is to restore the streams in the area by means that change the environment as little as possible, to make them suitable for migratory fish and to restore the naturally reproducing migratory fish stocks.
Nearly two kilometres of small streams flow through the islands, the water of which comes from the River Oulujoki via the Lasaretinväylä fairway gate-structure dam. The restoration of streams and year-round watering contribute to the return of sea trout and other migratory fish to the River Oulujoki.
The City of Oulu was responsible for the planning and implementation of the restoration of the streams, the procurement of the fishery monitoring equipment and the organisation of fishery research and monitoring. Oulun Energia will participate in the project both by funding the project and by watering the streams year-round, in accordance with the project schedule, from autumn 2018 onwards.
See also the restoration sites on the map (PDF)