Years of work to curb pollution in Wirral’s streams and rivers have been credited with seeing the Mersey Basin gaining recognition as one of the most improved river systems in Britain.

The River Dee also gained recognition in the Environment Agency list of the ten most improved rivers.

Painstaking efforts have been made to improve sewage systems, cut factory discharges, stop oil and chemicals being tipped into drains, and reduce fertiliser run-off from farmers' fields.

Improvements are set to continue, with the UK required to meet tough new EU targets on water quality by 2015.

The most improved rivers were: the River Wandle in London, the Thames, River Wear in County Durham, River Stour in Worcestershire, the River Darent in Kent, the River Dee flowing from Wales through north west England, River Nar in Norfolk, River Taff in South Wales, River Stour in Dorset and the Mersey Basin.

Wirral Euro-MP Chris Davies praised the efforts of all involved in bringing about the transformation.

He said: "I remember standing on the Mersey promenade in Liverpool back in the 1980s and watching lumps of sewage float by on the tide.

"Many of our local streams flow into the Mersey, and it is a fantastic achievement that it is now clean enough to support otters and salmon.

"It gives hope to the idea that we can tackle the pollution challenges our world faces."

The Liberal Democrat MEP claimed that European Union laws had played a key role in driving forward the improvements.

"Environmental improvements have been one of the success stories of the European Union", he said.

"Pollution pays no respect to national boundaries, and having common commitment and legal obligations to meet has helped stimulate action and secure public investment.

"Improvements would have been made without the EU laws on water quality, but the pace would have been very much slower."