Sonar reveals salmon recovery

Two Scottish rivers have recorded dramatic increases in returning salmon in their second year of sonar count data, with remarkable results for both conservation and angling.

In their second year of data release, the Laxford in Northwest Sutherland recorded 1,376 returning salmon in 2024, a healthy 23% increase. The Deveron in Aberdeenshire performed even better, with 8,796 salmon – a remarkable 54% jump.

An impossible level of precision

The Laxford and Deveron are the only two rivers in Scotland using state-of-the-art ARIS (Adaptive Resolution Imaging Sonar) systems, filming every salmon that passes and providing unprecedented accuracy compared to traditional angler catch reports.

Scientists now have precise counts of entire salmon runs rather than estimates, revealing the true scale of population changes. The technology highlighted the link between fish numbers and angling success: on the Deveron, angler catches jumped from 766 fish in 2023 to 1,711 in 2024. This level of precision is impossible with traditional monitoring methods.

River restoration projects

Both rivers are part of restoration projects run by the Atlantic Salmon Trust, working with local partners to improve habitat while monitoring results. The data also supports the Scottish Government’s annual assessments, which grade salmon rivers as good, moderate or poor based on whether they’re producing enough eggs to sustain their populations.

Mark Bilsby, CEO of the Atlantic Salmon Trust, said: “We hope that over time this new level of year-to-year accuracy will enable us to make a direct link between restoration efforts and recovering wild salmon populations.”

The success offers genuine hope at a time when Scotland needs it most, with salmon catches having hit their lowest level since records began in 1952 and 62 populations showing decline between 2011 and 2023. These results suggest that targeted restoration combined with accurate monitoring can reverse the trend.

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