Most areas along the coast have a higher than desirable impact from sea lice on wild fish, according to the experts' report from the production areas in 2024.
Photo: Frode Oppedal/HI.
A new report assessing the impact of sea lice on wild fish along the Norwegian coast in 2024 has raised concerns among experts and officials, revealing "higher-than-desirable" infestation levels in most aquaculture production areas.
The evaluation, a critical step in determining future policies for aquaculture growth and sustainability under Norway's traffic light system, is undertaken by an expert group and encompasses 13 production areas along the entire Norwegian coastline.
This year's analysis revealed varying levels of sea lice risk, with the highest risk found in Production Area 3 from Karmøy to Sotra, and "moderate" risk in a further eight production areas.
"With the warm summer this year, we were prepared that the lice impact would be higher in Northern Norway than in previous years. It is nevertheless concerning that wild salmon in most production areas are moderately affected by salmon lice," said Norwegian Minister of Fisheries and Oceans, Marianne Sivertsen Næss, announcing the findings.
The 2024 report is the first step in data collection for revision of Norway's "traffic light" system for aquaculture, a framework that adjusts permitted production levels based on the environmental impact of sea lice on wild salmonids. The findings will contribute to a comprehensive reassessment of production area traffic light designations in 2026.
While the study focused on wild salmon, it also reviewed sea lice larvae released from fish farms later in the season, in order to understand infection pressure on sea trout and sea char.
However, a formal assessment of sea lice-induced mortality for these species was not included due to the lack of an established methodology, the report authors noted. A new methodology, developed by the Norwegian Institute for Nature Research, is expected to be used in future assessments, potentially informing the 2026 traffic light update.
Norway's traffic light system divides the national aquaculture industry into 13 production areas, assigning colours - green for growth, yellow for neutral, and red for reduced capacity - based on the environmental impact of sea lice. The colour designations are reviewed every two years, with the next major update scheduled for 2026.
