The European eel is a remarkable migratory fish: it spends most of its life in fresh inland waters but migrates to the Sargasso Sea in the Atlantic to spawn. Mature eels leave inland waters and travel through the Baltic Sea and the Danish Straits to the Atlantic Ocean. After spawning, the larvae drift back toward Europe on the Gulf Stream and eventually return to inland waters.
European eel populations have declined significantly across Europe – for many reasons
The decline of European eel populations has been linked to several factors, including overfishing, hydropower plants, and hydraulic engineering structures such as dams. Climate change, habitat and ocean current changes, diseases, and pollution may also contribute to the species’ decline.
For decades, the negative impacts of hydropower and water infrastructure on fish populations and fisheries have been offset by fisheries fees paid by power companies. These funds are used by authorities to stock various fish species and to conduct studies and surveys.
One of the species stocked is the European eel. According to the Pirkanmaa Fisheries Center, a total of 660,000 eels were stocked in the Kokemäenjoki River basin upstream of the dams between 1989 and 2023. From there, the eels migrate downstream, and unfortunately, due to their elongated shape and the large number of dams along the route, some do not survive the journey.
Action is needed to improve the situation
Fishing restrictions have already been tightened, and stocking upstream of dams has been reduced. The Pirkanmaa Fisheries Center is currently running a project with fisheries authorities, the Pirkkala Fisheries Area, and the Natural Resources Institute Finland, in which European eels are caught and transported downstream of the dams. The project is called “From the Kokemäenjoki River to the Sargasso Sea (link to a Finnish website).”
Last year, power companies, the Kokemäenjoki Water Protection Association (KVVY), and the Natural Resources Institute Finland attempted to launch a similar project, but it unfortunately did not receive funding from the European Maritime, Fisheries, and Aquaculture Fund – meaning a promising initiative could not be implemented.
Achieving results through stakeholder cooperation
The Kokemäenjoki River Basin now has an opportunity to address the European eel situation through broad, coordinated stakeholder collaboration. Power companies are prepared to take voluntary measures to support eels together with fisheries authorities, the Fisheries Center, fisheries regions, shareholder associations, NGOs, and other partners – for example, by expanding the successful ongoing project.
Much has been done – and more is underway
UPM Energy pays annual fisheries fees for its hydropower facilities. In addition to these statutory fees, the company runs a voluntary stream water program aimed at restoring or rehabilitating 500 kilometers of streams and waterways by 2030 (baseline year 2015). By the end of 2025, 323 kilometers had already been achieved. We calculate kilometers based on UPM’s share of project funding. For example, if we cover 10% of the costs of restoring a 100 kilometer stretch, we record 10 kilometers towards our target. In total, we have helped restore more than 1,100 kilometers of streams and waterways.
In 2025, we contributed to projects such as Virtaankoski in Sysmä, Kuusinkijoki in Kuusamo, Kurunkoski on the Torsanjoki River in Rautjärvi, and Linnanvirta in Savonlinna. We also arranged two volunteer days on UPM owned land in Karkkila.
Promising projects are planned for the current year as well. The Louhikoski dam removal on the Tipasjoki River in Sotkamo, the Joutsenkoski dam removal on the Urpalanjoki River in Lappeenranta, and the Lietukkajoki dam removal in Outokumpu are all progressing, and we are participating in each of them as funders. Our goal of freeing up 500 kilometers of streams and waterways is now within reach, one dam and one rapid at a time.
You can learn more about our stream water program here.