Brown trout in regulated lakes

We need better knowledge about the brown trout, a fish species that has been severely affected by hydropower development. This project studies the brown trout populations in inland Norrland to understand the environmental conditions required for the species to recover.

The brown trout is of great value to nature, culture, and recreational fishing, but many populations have declined sharply due to the impact of hydropower on spawning grounds and migration routes. Despite extensive research, there are still major gaps in our knowledge of the brown trout’s habitats in our northern lakes.

This project will collect data on the occurrence, spawning population size, diet, and growth in a large number of lakes from Härjedalen to Norrbotten. The project will analyse how the lakes’ morphometry, climate, reproduction areas, and prey fish communities affect the occurrence and life history of brown trout.

The results will provide important knowledge for managing conflicts between hydropower production and nature conservation, and facilitate the recovery of Europe’s remaining brown trout stocks.