Hydroelectric Plant Linked to Salmon Injuries in Norway’s Namsen River

A new hydroelectric power plant in Norway is facing scrutiny after a significant increase in injuries observed in wild Atlantic salmon caught in the Namsen River, one of the country’s most important salmon waterways. Researchers at the Norwegian Institute for Nature Research (NINA) have documented unusual snout and jaw damage in salmon, raising concerns about the plant’s impact on the fish population.

Extent of the Injuries

Monitoring fishing conducted by NINA below the Nedre Fiskumfoss hydropower plant revealed a concerning trend. In autumn 2024, 73 wild salmon were caught, with over half exhibiting injuries, particularly to the snout and jaw. This contrasts sharply with the previous year, where only 17 salmon showed similar damage. The injuries often penetrate the skin, potentially causing pain, disrupting the fish’s sense of smell, and increasing susceptibility to infection, according to Åse Helene Garseth, the specialist responsible for wild salmon health at the Veterinary Institute.

The Nedre Fiskumfoss Power Plant

The Nedre Fiskumfoss plant, the largest hydroelectric facility built in Trøndelag since the 1990s, began operations in April 2024. NTE, the power company operating the plant, invested over one billion kroner in its development, aiming to supply electricity to 50,000 households – a 40 percent increase over the previous power station. To mitigate the impact on salmon migration, NTE implemented several measures, including new fishing barriers and alternative routes for the fish to bypass the turbines.

NVE Investigation and Concerns

The Norwegian Water Resources and Energy Directorate (NVE) has indicated it is “predominantly likely” that the new power plant is harming the salmon population. NVE recently issued a notice to reassess the current license conditions for the plant. The agency noted that NTE had no video surveillance below the power plant in 2024, and previous monitoring showed salmon entering the plant and sustaining turbine-related injuries. However, NTE maintains that after modifications to the fish barrier in 2025, their monitoring has not detected any injured fish.

Researcher Observations

Eva B. Thorstad, a researcher at NINA, emphasizes the unusual nature of the observations. “I have never seen similar damage to salmon on such a large scale,” she stated. NINA monitors nearly 200 waterways in Norway annually. Thorstad also raises the possibility that the monitoring catches may not represent the full extent of injuries within the river, suggesting there could be more severely injured fish that are less likely to be caught during routine monitoring.

NTE’s Response and Mitigation Efforts

Vemund Gjertsen, expert consultant for environment and property at NTE, acknowledges the responsibility of operating hydropower in a vital salmon river like the Namsen. He stated that issues with the initial fish barrier were identified and addressed in consultation with NVE and other experts. NTE has implemented several measures to protect salmon, including a dedicated tunnel for fish passage, automatic sluice gates for stable water flow, and an improved fish barrier in the drainage tunnel. They also upgraded the fishing ladder for salmon migrating upstream.

Regulatory Oversight and Animal Welfare

The Norwegian Food Safety Authority was notified of the situation in June 2025 by the Veterinary Institute and subsequently engaged with NVE. Geir Arne Ystmark, head of department at the Norwegian Food Safety Authority, highlighted that damage to wild fish caused by turbines is an animal welfare concern. He indicated that a new licensing process could incorporate specific measures to safeguard wild fish.

Looking Ahead

NTE has been given a deadline of March 26, 2026, to respond to NVE’s notification regarding a potential review of the concession. The Namsen River remains one of Norway’s most important salmon rivers, and the ongoing investigation aims to balance hydropower production with the preservation of this valuable natural resource.