01/10/2026
That’s officially a wrap on our electrofishing season! 🐟
Across 211 surveys on 69 watercourses, our teams recorded 4,577 trout and 6,328 salmon. Our official fish survey report with detailed catchment breakdowns will be released in a few months, so keep an eye out for the full analysis! 📊
A massive thank you to all our dedicated interns and volunteers who contributed hundreds of hours of hands-on assistance across the catchment - we couldn’t gather this vital data without you! 👏
Alongside our fish surveys, our team closely monitored water temperatures to ensure it was safe to work. When drought conditions and low river flows pushed temperatures up, electrofishing was paused to protect the fish, but we recorded some sobering peak readings:
🌡️13th July – Dub Beck (near Loweswater): 20.9°C
🌡️ 14th July – River Derwent (Cockermouth): 20.2°C
🌡️ 28th July – River Derwent (near Bassenthwaite): 20.0°C
🌡️ 29th July – River Cocker (near Lorton): 18.9°C
🌡️ 30th July – Lower Derwent (near Workington): 21.9°C
These figures are likely an underestimate of how widespread the heat issues were. From 15th July onwards, readings across all our target rivers were so consistently high that we stopped checking temperatures to see if we could survey; we simply paused everything and waited until the weather cooled down.
Atlantic salmon and wild brown trout begin to experience thermal stress at temperatures from 18°C upwards, which reduces available oxygen levels in the water and places significant physical strain on cold-water fish.
While water temperature dynamics across a river system are complex, open upper reaches that lack tree cover are particularly vulnerable to direct solar heating during dry, low-flow periods.
Without meeting global Net Zero targets to curb warming, these extreme summer temperatures are only projected to worsen. Planting native trees along our watercourses (riparian shading) acts as a natural canopy - giving our rivers immediate climate resilience while keeping waters cool for the future. We need more trees on our rivers! 🌳
