What is a pink salmon?

Last changed: 04 May 2023
the open mouth of a pink salmon

The pink salmon (Oncorhynchus gorbuscha, in Swedish puckellax) is an alien species in Sweden and has probably migrated here from the Kola Peninsula via Norway. During 2023, SLU is investigating the spread of spawning pink salmon in Sweden and we need the public's help by reporting their sightings/catches of pink salmon to Artfakta/Rappen.


The pink salmon has been observed in increased numbers in several western Swedish rivers since 2017. How it affects our native fish species, such as Atlantic salmon and trout, if it spawns in Swedish rivers is currently unknown. Nor is it known how it affects the aquatic ecosystem in general.

Pink salmon have a 2-year life cycle and spawn every other year (mainly odd year in Europe) and the next spawning cycle expected in 2023. They often spawn in July-August and after spawning the pinks die in the river. The young emerge from the gravel during the late winter - early spring of the year after spawning and quickly leave the waterways.

During 2024, SLU will investigate whether the spawning was successful in the rivers where the most pink salmon were detected.

How to recognise a pink salmon

  • The male develops a characteristic hump on his back before spawning. ​
  • Black dots on the tail
  • Black tongue
  • A mature adult pink salmon is about 40-55 cm long, but can grow up to 75 cm and weighing of up to 5 kilos
  • Download the information flyer here

Male and female pink salmon, Norway. Credit Eva Thorstad, NINA_hane_hona.jpg

Photo: Eva Thorstad, NINA


More information about pink salmon


The article Pink salmon distribution in Sweden: The calm before the storm? Has been published in Ecology and Evolution 2022.

SLUs earlier Overview, risk assessment and proposed measures for pink salmon in  Aqua reports 2018:17, (Swedish; abstract in English).

Distribution and abundance of pink salmon across the North Atlantic Report of the Working Group on North Atlantic Salmon (nasco.int)

Websites and presentations

Pink Salmon (NINA, Norwegian Institute for Natural Research)

Emerging Threats - Pink Salmon (Atlantic Salmon Trust)


If you have any questions or need more information contact puckellax@slu.se

Tom Staveley, Researcher
Department of Aquatic Resources, Institute of Freshwater Research, SLU
tom.staveley@slu.se, +46(0)10-478 42 52

Ida Ahlbeck Bergendahl, Environmental Monitoring and Assessment Analyst
Department of Aquatic Resources, Institute of Freshwater Research, SLU
ida.ahlbeck.bergendahl@slu.se, +46(0)10-478 42 50