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

Pink salmon (Oncorhynchus gorbuscha), introduced to Russia's Kola Peninsula in the mid-20th century, now return to Norwegian rivers in huge numbers every odd year, following a fixed two-year life cycle. Norway's Environment Agency (Miljødirektoratet) describes native Atlantic salmon as now itself 'at risk of extinction' — only around 323,000 wild spawners were counted nationally in 2024 — while 481,463 pink salmon were caught or observed across Norwegian rivers in 2023 alone.

The agency funds state trapping infrastructure that expanded from early feasibility pilots to 63 rivers with state-funded control measures by 2025, 53 of them fitted with fish traps. The best-documented site is a 400-metre pole-row trap at Seida on the Tana River, operated by the Veterinary Institute, which caught and euthanised 7,666 pink salmon in 2023. National catches during the 2025 run reached roughly 150,000 fish by mid-summer, with about 30,000 taken from the Tana alone; Atlantic salmon caught incidentally are released alive, for example 47 released on a single day.

A peer-reviewed study on the Skallelv river (Varanger Peninsula) found white-tailed eagle sightings rose from a mean of 0.38 to 10.9 per day as pink salmon carcasses became available during a 2021-2022 invasion, direct evidence that the invasion — and the resulting removal operation — is reshaping the river's food web.

Officials describe the Tana trap explicitly as a pilot rather than a solution, since 'considerable quantities' of fish passed through unblocked in 2023. National catch totals have grown across the 2021, 2023 and 2025 cycles even as trapping capacity expanded, and available sources do not disambiguate whether this reflects continued invasion pressure or simply improved trapping infrastructure.

Read the full analysis: https://www.environmentagency.no/areas-of-activity/hunting-and-fishing/pink-salmon-oncorhynchus-gorbuscha/