The potential of non-native pink salmon to boost Arctic ecosystems – a threat or an opportunity?

Centre for multidisciplinary research: Kvantum
Faculty: Science

Pacific pink salmon (a. ka humpback salmon; Oncorhynchus gorbuscha), a non-native salmonid in North-Europe, has had in recent years large influxes to northernmost rivers in Europe, including Finnish parts of Teno and Näätämö rivers. Pink salmon is easily seen as a severe threat especially to native Atlantic salmon and salmon-related livelihoods. However, pink salmon invasion is likely to have broader ecosystem consequences starting from the very bottom of the food webs and transferring across aquatic-terrestrial ecosystem boundaries.

The lifecycle of pink salmon differs greatly from the native Atlantic salmon and brown trout. After hatching in spring fry migrate to sea and returns to spawn to rivers already after one sea-year. Adults die soon after spawning their carcasses remaining in rivers or ending up to the shores. In its native distribution areas, marine-derived nutrients released from dead pink salmon are a key resource both for rivers and their terrestrial surroundings. Arctic ecosystems are among the least productive ones, their biota consisting of partly unique species adapted to resource scarcity, and to demanding physical habitats. Decaying pink salmon carcasses may then provide a new, additional resource of food and nutrients for ecosystems not used to such prosperity. Consequently, the occurrence of pink salmon may have potential to boost Arctic river systems serving them an opportunity to become more productive, but that is likely to happen at the cost of original biodiversity.

In this projects, we focus on pink salmon’s potential to affect key ecosystem processes and change community structure of the native fauna and flora and, consequently, to have complicated effects across food webs. The research project utilizes multidisciplinary approaches and expertise of various research fields to reach its aims.

Research is conducted in the Ecology and Genetics Research Unit in close collaboration with Water, Energy and Environmental Engineering Research Unit.

Researchers ask the public for help – please report your observations

The public can give information on the places where dead pink salmon accumulate by sending a text message to the number +358 45 638 7271. The message should contain at least the coordinates of the pink salmon observation or pile (e.g. from standard map applications Google maps, Retkikartta, WhatsApp or similar). In addition, if possible, members of the public are asked to send a picture or a free-form description of the the carcass or pile of carcasses (e.g. how many carcasses, an estimate of the depth of the water and the structure of the bottom).

By sending the message, the sender confirms that they have read the privacy statement. Messages will be deleted immediately after saving the coordinates, i.e. personal data such as names or phone numbers are not collected in a register.

Researchers:

Doctoral researcher Aino Erkinaro, Ecology and Genetics Research Unit (email: aino.erkinaro@oulu.fi, Twitter: @AinoErkinaro)

PI Academy Research Fellow Kaisa-Leena Huttunen, Finnish Environment Institute - Nature Solutions Unit, University of Oulu - Ecology and Genetics Research Unit (Twitter: @KLHuttunen)

Academy Research Fellow Sami Kivelä, Ecology and Genetics Research Unit

Associate Professor Hannu Marttila, Water, Energy and Environmental Engineering Research Unit