Voimalohi on a field trip to North America

Early in summer 2023, ten Finnish experts travelled to the east coast of North America to learn about migratory fish solutions in the harnessed rivers of New Brunswick in Canada and Maine in the USA. It was an interdisciplinary group: there were three fish experts from Voimalohi, including myself, plus power company executives and experts on the environment, technology and law.

Why did we travel across the Atlantic?

Migratory fish restoration work is relatively new in Finland, and we do not have many fishway options for large rivers. Similar work has been done for much longer in our neighbouring countries, and for several decades at our field trip destinations. Research data and experience of different options from a long time span will help us develop models tailored to our local conditions.

Moreover, our circumstances are quite similar. Even the salmon species that rises in the big Finnish rivers is the same – the Atlantic salmon. The rivers we visited have several power plants in a row, like we do on the Iijoki and Kemijoki rivers. This configuration of several power plants, which is typical for Finland, creates its own challenges for the work on migratory fish. It would be difficult to find a similar setup with migratory fish solutions closer to home than America.

We wanted to see upstream migration solutions for adult migratory fish and downstream migration routes for smolts that are starting their migration to the sea. Of course, the locals have their own challenges – in North America, the Atlantic salmon stock that rises in rivers has experienced an alarming decline. Climate change and warming sea water are adversely affecting migratory fish, with fewer returning to rivers. The same trend is also a concern in Finland. Here too, salmon numbers have been poor this summer, and researchers have been unable to determine any single reason for this.

Solutions must be tailored to the micro-environment

As the work has been ongoing for so long, our North American colleagues have had their share of both successes and failures. Due to the local fixed-term hydropower licensing practice, there are active efforts to identify inefficient solutions and replace them with better ones. Information about both the successes and the failures is crucial to us as we consider our own opportunities and solutions in Finland.

The highlights of the field trip were the different solutions used at the different sites, driven by the environment and the conditions. Different conditions can be found even along the same river due to characteristics such as differences in altitude and the space available for construction.

That is why the solutions, whether natural or engineered channels, must always be tailored to the current micro-environment and conditions. The solutions that work best are often based on details that take the specific characteristics of the location into account. They are best seen and understood on site.

Experiences to support development work

At Voimalohi, we are expanding our scope of operation to the restoration of migratory fish stocks in harnessed rivers, including the development of fishways, transport of fish and downstream migration routes, as well as the restoration of fish stocks and supportive stocking of rivers.

Fishways for all the power plants on the Iijoki river are planned, and the experiences and lessons learned from the field trip will be useful in this planning work for a long time to come. We are already reaping tangible benefits from some of the new experiences and observations. At the uppermost power plant on the Iijoki river, Haapakoski, we have a brand new downstream migration route for smolt and catching equipment. We already have ideas on their development and improvement, partly thanks to the new experiences.

One important lesson learned from North America was that development work inevitably takes time and is never fully completed. The successful restoration of migratory fish requires continuous monitoring and research, as well as actions based on these findings, not only during the design of fishways but also after construction.

Mikko Jaukkuri

Head or Research and Development, Voimalohi Oy