The return of the salmon is good news for fly fishermen - and for conservationists who have worked hard to restore numbers after the fish's disastrous decline two decades ago.
However, experts warn that the current increase - revealed in statistics for salmon tagged and counted in 2010 and from observations from river banks this year - may only be temporary.
"We still don't know why this is happening. It may just be a one-off or it could be a general trend to a return to healthy salmon numbers in our rivers," said Dr Anton Ibbotson, of the Game and Wildlife Conservation Trust.
Some of the most detailed figures on salmon numbers have come from the river Frome in Dorset. Conservation experts have been able to monitor fish more easily and in greater detail on this modestly sized waterway than on the nation's great salmon rivers such as the Tweed and Tay, and at East Stoke they have introduced a system that can accurately count salmon in the river. Read the full report here.
Source: Robin McKie, Science Editor, The Observer, Guardian.co.uk.
