Brown Trout

Brown trout (Photo: Juho Vuolteenaho)

Brown trout (Salmo trutta) is a freshwater fish that is popular for recreational fishing in Norway and is an important host species for the larvae of the freshwater pearl mussel (more information about this can be found here).

In the Pasvik River, the brown trout population is threatened by a combination of factors, including hydroelectric dams and insufficient spawning grounds, and fishing. Management measures include stocking to support the population.

Brown trout (Photo: Juho Vuolteenaho)

We are using this species as a model to study the impact of different human activities on genetic diversity, connectivity, and temporal population composition. Further, we are interested studying the effects of pollution on gene expression patterns.

Electrofishing (Photo: Juho Vuolteenaho)

We are also studying the tributaries of the Pasvik River to better understand how those are used in spawning and to see how stocking may influence the genetic composition of local tributary populations.

Finally, we are conducting pedigree analyses to assess and provide information to the stocking program.

Fish mail box at the station

Citizen Science

Local fishermen and recreational anglers kindly help us with our collection efforts by taking fin clips of their catches and deliver them to our fish mail box at the station. Thanks a lot for your continuous help!

Check out also our brown trout database (which will be updated soon!): https://orretbasen.com/

Relevant Literature

Klütsch, C. F. C., Maduna, S. N., Polikarpova, N., Forfang, K.Aspholm, P. E.Nyman, T.Eiken, H. G., Amundsen, P. A. & Hagen, S. B. 2019. Genetic changes caused by restocking and hydroelectric dams in demographically bottlenecked brown trout in a transnational subarctic riverine system. Ecology and Evolution 9: 6068–6081. [Pdf]