How will dead pink salmon affect northern nature? Researchers are asking the public for help

The pink salmon is an alien species that is taking over northern rivers again this summer. Estimates regarding the number of pink salmon vary, but in the worst case in the river Teno, even hundreds of thousands of pink salmon could come in the river. Pink salmon die in rivers shortly after spawning, their carcasses remaining in rivers and on shores.
Pink salmon, kyttyrälohi. Photo: Panu Orell, Luke

Researchers from the University of Oulu and the Finnish Environment Institute are investigating how the decomposing pink salmon carcasses affect rivers and their surrounding environments. The public is being asked to help researchers by informing of the places where carcasses naturally accumulate.

Doctoral researcher Aino Erkinaro from the University of Oulu and project leader, researcher Kaisa-Leena Huttunen from the Finnish Environment Institute study the decomposition of pink salmon carcasses in August–September in Norwegian and Finnish rivers. The research focuses on how decomposing carcasses affect the nutrient concentrations of rivers and shores, how far the effect of nutrients can be seen in time and place, and whether the effects of nutrient changes can be seen in living organisms.

"It's really wild when a major change happens so quickly," says Erkinaro.

"The situation is shocking from the standpoint of northern nature, but also extremely interesting for a researcher."

The pink salmon research wants to make use of citizen science. "We need help from fishermen, hikers, and people who move in nature to find those places where pink salmon carcasses naturally accumulate, both in rivers and on shores. This way we can get information on what kinds of places the pink salmon carcasses will pile up, which is of great benefit when studying the movements of nutrients,” says Erkinaro.

"We are very grateful to the public for their help in this important work. This research will help us get a better picture of what the future of northern rivers will be.”

More information about the study and how to send observations on the project page.

Contact information

Doctoral Researcher Aino Erkinaro, +358 45 6387271,

Erkinaro is a part of the Stream Ecology Research Group at the University of Oulu, which is led by Professor Timo Muotka ( The pink salmon project is led by Researcher Kaisa-Leena Huttunen at the Finnish Environment Institute (

Photo: Panu Orell, Luke

Last updated: 17.4.2024