State-Funded Pink Salmon (Pukkellaks) Trapping Programme — Tana River (Norway)

Pink salmon (Oncorhynchus gorbuscha), originally introduced to Russia's Kola Peninsula in the mid-20th century, now invade Norwegian rivers biennially, arriving in odd years (2021, 2023, 2025) with further recurrence expected in 2027. Norway's Environment Agency (Miljodirektoratet) describes native Atlantic salmon as 'at risk of extinction', with only approximately 323,000 wild spawners counted nationally in 2024. The Tana River, managed jointly with cross-border partners including Statsforvalteren i Troms og Finnmark, is one of the country's most significant salmon rivers.

To trap and remove invasive pink salmon before they can spawn and compete with native Atlantic salmon, while releasing incidentally-caught Atlantic salmon alive, in the context of a nationally expanding, state-funded control programme.

Miljodirektoratet, the Norwegian Veterinary Institute (Veterinaerinstituttet) and Statsforvalteren i Troms og Finnmark operate fish traps on Norwegian rivers during biennial pink salmon runs. The flagship installation is a 400-metre pole-row trap at Seida on the Tana River, run by the Veterinary Institute. By 2025, state-funded control measures were in place on 63 rivers nationally, with 53 fitted with fish traps. Trapped pink salmon are euthanised; incidentally caught Atlantic salmon are released alive.

In 2023, 481,463 pink salmon were caught or observed nationally, including 7,666 at the Seida trap on the Tana River; officials nonetheless described the Tana trap as 'a pilot rather than a solution' since 'considerable quantities' of fish passed through unblocked that year. By mid-summer 2025, roughly 150,000 fish had been caught nationally, approximately 30,000 of them from the Tana River alone. On a single documented day, 47 incidentally-caught Atlantic salmon were released alive. A peer-reviewed ecosystem study on the Skallelv river found that white-tailed eagle sightings rose from a mean of 0.38 to 10.9 per day during the 2021-2022 pink salmon invasion, as carcasses became available as a food source.

Catch totals have grown across successive biennial cycles despite expanded trapping infrastructure, though available sources do not clarify whether this reflects rising invasion pressure, improved trapping efficiency, or both. The programme is transparently scaled and reported annually, but suppression efficacy at flagship sites like Tana remains unconfirmed by officials' own account.