The fish pass has been in operation for over 20 years. To date, more than 17,000 salmon and nearly 4,000 trout have used it to migrate upstream. These figures are based on a fish counter, and weekly fish reports are published on Oulun Energia’s website.

It is a positive development that, after a few quieter years, the migration of fish has clearly picked up this summer. The high number of migrating fish also partly explains the unfortunate incident discussed in social media and the press on Wednesday, 27 August, when an unusually large number of fish became trapped in the deep pools of the dam basin. As a result, a short bypass flow was implemented to rescue the fish.

Oulun Energia, in collaboration with the City of Oulu, is committed to developing the Merikoski area and improving conditions for migratory fish. The development of the Merikoski area is a large-scale initiative involving various activities and potential areas for improvement. In the Merikoski development project, we work together with the City of Oulu to assess and decide on the measures to be implemented, and we will communicate further once decisions are made. The project supports the waterway vision for the Oulujoki river basin created under the Arvovesi initiative, a city council motion from 2020, and regional water management plans.

As a rapid measure to improve the functionality of the fish pass, we have already initiated planning for structural changes to the deep pools and basins of the dam. The preliminary plan involves rock excavation and water drainage adjustments to guide fish into the fishway and prevent them from becoming trapped. These modifications are scheduled to take place later this autumn or early winter after the fish pass is closed, provided weather and safety conditions allow. We will provide further updates as the plans become more detailed.