Sea trout return to cleaner rivers

The numbers of sea trout and salmon found in some English rivers have hit record highs this year, thanks to efforts to clean up polluted waterways.

More than 15,000 of the fish have been recorded migrating up the River Tyne – in which no salmon and trout were seen 50 years ago – according to studies by the Environment Agency.

Record numbers of sea trout have been spotted in the Thames, a river once declared biologically dead, while the Mersey – formerly the most polluted river in Europe – is at its cleanest for 100 years, the agency said yesterday.

The quality of river water in England had improved for the 20th consecutive year, the agency reported, with 70 per cent of rivers graded as "very good" or "good" under its general quality assessment classification.

Improvements were achieved through investment by water companies, tougher action against polluters, reducing discharges from industry into waterways and changing farming practices, the Environment Agency explained.