Finland has around 159,000 kilometres of rivers, of which more than 90% are regulated or otherwise modified. The construction of hydroelectric power plants has severed the migration routes of fish in many rivers. Other factors that have affected the natural state of these river systems include water regulation, the clearing of river beds for log floating and the ditching of catchment areas.

Projects aiming at the restoration of migratory fish populations and the construction of fishways are top priorities in environmental management.  Comprehensive, efficient and simultaneous support and regulation measures facilitate the restoration of migratory fish populations in regulated rivers.

Finland’s National Fish Passage Strategy aims to enhance the viability of migratory fish stocks by shifting the focus from fish stocking to supporting and rehabilitating the natural reproductive cycles of fish. Studies of regulated rivers conducted at the Natural Resources Institute Finland are providing the required knowledge base for this purpose.

Picture on top of the page: Panu Orell/Luke