Bid to improve River Wensum's ecosystem in Norfolk
Environmental scientists at the University of East Anglia (UEA) hope to improve the water quality of a Norfolk river as part of a £2m study.
Researchers, farmers and government agencies will work together to help the Wensum, the UEA said.
Monitoring stations on the river will measure the effectiveness of steps to reduce pollution.
More than 99.4% of the river's habitat is "unfavourable and declining", the UEA added.
Grass buffer strips
The river's poor condition is due mainly to phosphate pollution and sediment deposits, caused by run-off from farmed land and other sources such as roads and local sewage treatment works, the university said.
Steps being taken to reduce pollution include creating grass buffer strips at the edges of fields to soak up sediment and planting hedgerows between fields and rivers.
The Wensum flows through Norwich on its course from Whissonsett to Whitlingham and has more than 100 plant species and a rich invertebrate fauna.
Species under threat include bullhead and brook lamprey fish, white-clawed crayfish, Desmoulin's whorl snail and water starwort.
The four-year Wensum Alliance has been funded by Defra, the Environment Agency and the Welsh Assembly and is one of three projects, along with the Eden in Cumbria and the Avon in Hampshire.