Young Atlantic salmon have been recorded in three north-west England rivers for the first time since 2015.
The critically endangered species was spotted in the Mersey, Bollin and Goyt rivers.
The sightings confirm the fish successfully migrated from Arctic feeding grounds to spawn.
Salmon return to freshwater gravel beds after two to three years at sea.
The Environment Agency described the discovery as a significant environmental turnaround.
Officials plan a new distribution study using eDNA sampling in early 2026.
Atlantic salmon populations in Britain have fallen by 30–50% since 2006.
Climate change, pollution, invasive species and river barriers remain major threats.
Water quality improvements have helped revive previously polluted rivers.
However, dams, weirs and locks still block salmon access in several catchments.
Conservation groups say fish passes are urgently needed to support recovery.
