The status of Norwegian wild Atlantic salmon is evaluated annually by the Norwegian Scientific Advisory Committee for Atlantic Salmon. This is an English summary of the 2021 report.
The number of salmon returning from the ocean to Norway each year is now half of the level recorded in the 1980s. Still, the number of salmon spawning in the rivers has increased. The increased number of spawners despite reduced numbers returning from the ocean is due to reduced fisheries in the sea and rivers. Reduced exploitation has more than compensated for the decline.
The reasons for the decline of Atlantic salmon are impacts of human activities in combination with a large-scale decline in the sea survival. The largest population declines are seen in western and middle Norway, and negative impacts of salmon farming have contributed to this. Escaped farmed salmon, salmon lice and infections related to salmon farming are the greatest anthropogenic threats to Norwegian wild salmon. The present mitigation measures are insufficient to stabilize and reduce these threats.
Hydropower production and other habitat alterations are also threats to salmon. There is great potential for improving conditions for salmon in regulated rivers. Invasive pink salmon is a new threat, and there is need for national and international measures to reduce the risk of negative impacts on native salmonids, including Atlantic salmon.
Climate change impacts Atlantic salmon populations negatively. Climate change increases the need to reduce the impacts of other threats to support the ability of Atlantic salmon to adapt to changing environments.
A new classification of the state of all the 449 salmon populations showed that only one fifth of the populations were in a good or very good state, whereas more than one third of the populations were in a poor or very poor state. The state of the populations in 2015-2019 was not improved compared to in 2010-2014, and there was no change in the impact factors that had the strongest negative impact on the populations.
Summary of the report in English (pdf).
The 2021 annual report is published in Norwegian.