Hydropower production alters the range and rhythm of the water level in waterways as well as the flow rates, compared to their natural state. The changes affect e.g. the fishing industry and the ecology of the waterways. Power plant dams prevent fish from natural migration. Damming and regulation weaken and decrease the number of fish reproduction areas and change the nutritional conditions.
Stocking used to mitigate impacts
Fortum mitigates the impacts on fishing in the vicinity of its power plants mainly by stocking fish. Hydropower production’s fishing industry obligations are based on permit regulations set by authorities, and Fortum’s obligations are mainly fish stocking obligations.
Every year Fortum stocks about 700,000 salmon smolt in the Gulf of Bothnia in Finland and Sweden. Whitefish, zander and lake trout, for example, are released into the rivers and regulated lakes where hydropower is produced. Fortum has fish farms of its own in Finland and Sweden.
Fish stocking or fishways?
For Fortum, improving migratory fish habitats and strengthening wild fish populations are important goals. The most effective means to achieve these goals depend on the water system. In practice, the means are selected and planned in collaboration with the relevant parties and authorities.
Rather than obligatory fishways, the authorities require Fortum and other power companies with hydropower operations on major regulated rivers to stock fish because fish stocking is estimated as being the best way to compensate the adverse impacts on the fishing industry. Restoring migratory fish populations with fishways requires spawning and reproduction areas. There are not many of these reproduction areas in rivers that have been completely or partially regulated for decades.
Fortum has participated in all the projects that have studied the conditions for building fishways at the company’s power plants. The projects have examined practical matters related to building fishways, the benefits to be achieved with fishways, other support measures to restore migratory fish (e.g. restoration of reproduction areas, stocking support, transfers over dams), and they have developed fishway design plans. For example, the restocking of salmon smolt is one of the ongoing support measures underway in the Oulujoki river to restore migratory fish. Fortum has funded and participated in all of these projects for years.
Researching migratory fish in regulated rivers
Fortum is continuously developing the fish management obligation in collaboration with the authorities and other stakeholders, including representatives of local fishermen. The company also contributes labour and funding for the studies focusing on migratory fish populations. In Finland e.g. Fortum has actively participated in initiating and funding the research by Finnish Game and Fisheries Research Institution to explore ways to restore migratory fish in regulated rivers.
Fortum is an active participant also in the migratory fish forum, which promotes the exchange of information among authorities, hydropower companies and research communities.