The Merikoski fishway, a well-known and popular landmark, provides a path for fish to swim upriver from the sea past the Merikoski hydro power plant. Thanks to the fishway, salmon and other migratory fish can reach a 40-kilometre stretch of the river above the Merikoski power plant up to the next power plant in Montta, and swim to the Muhosjoki and Sanginjoki rivers, tributaries of the Oulujoki river.
To reach the upper reservoir of the Merikoski power plant and continue upriver the fish must navigate a number of turns and steps. They must first find the entrance of the fishway, and then swim a stretch of 750 metres with 64 steps to climb to the required level, 11 metres above sea level. The most difficult challenge in building the fishway was how to signpost this complicated route.
The route consists of three parts. Entrance to the fishway is in the old log floating flume by the hydro power plant. The middle part is an ascending groove dredged to the old river bed, and the final climbing section is formed by landscaped, stream-like stretch in the Hupisaari Park.
Unforgettable experience for fish lovers
The Merikoski fishway is open from the beginning of May to late October. The ideal watching place is not, however, on the shore, but via the highly popular underwater webcam.
At the top end of the fishway in Lasaretinsaari island, next to the Lassinkallionsilta Bridge (the dam bridge), is an observation room with underwater view to the fish path built mainly for research purposes. The observation room is open to the public during demonstrations arranged a couple of times every summer.
The observation room on the map.