The sudden increase in pink salmon (Oncorhynchus gorbuscha) in Norwegian rivers in 2017, is thought to be linked to favourable climate conditions for pink salmon reproduction and survival, and is expected to continue as seawater temperatures rise. Anadromous fishes, such as Pacific and Atlantic salmon that migrate between the highly productive marine and less productive freshwater environments, transport energy and nutrients that subsidize freshwater and terrestrial food webs. Considerable research in North America has demonstrated the significant effect of these marine derived subsidies on the structure and function of terrestrial riverine ecosystems. But the role of marine-derived resources from the invasive pink salmon in Norway`s terrestrial environment remains unstudied. The objective of this project is to understand the effects of marine-derived energy and nutrients from pink salmon returns on terrestrial ecosystems in the oligotrophic subarctic tundra. Field work will take place in Varanger, Finnmark, in a river where large runs of pink salmon were experienced in 2017. The transfer of energy from the carcasses of pink salmon through the terrestrial food web will be quantified using terrestrial scavenger camera observations and stable isotope analysis using methodology used effectively in Alaska. The information provided by this project will be valuable in the development of future management strategies for pink salmon invasions in northern Norway. Results will be disseminated through APN and NINA media platforms, a potential Fram Forum article in 2020 and outreach workshops, in addition to a Master`s thesis.
Project manager: Guttorm Christensen
Project code: 832018