Citizen testing of rivers in England and Wales by anglers reveals that more than a third of freshwater sites breach phosphate levels for good ecological status.

Volunteers from angling groups are using the data to try to drive change in the way rivers are treated – but the task ahead is huge, according to the Angling Trust and Fish Legal.

“Our freshwater habitats are in crisis – a fact now widely recognised by the public, politicians and regulators,” the chief executive, Jamie Cook, said. “Many anglers already knew this, having witnessed the decline in water quality at our favourite fishing spots.