A £1m government grant has been made to restore dwindling fish populations in the River Monnow in Herefordshire.
The decline in trout has had an effect on other animals
The number of trout and grayling in the river and its tributaries has fallen away over the years because of a decline in rural practices such as clog-making.
Traditionally, people gathering wood to make clogs had cut back riverside trees, allowing much-needed sunlight to reach the water.
But the clog-making industry's decline, combined with livestock breaking down the river's banks and causing it to carry silt, has led to a change in the Monnow's ecosystem.
We hope that the result of all the effort will be a much better habitat for wildlife
The money, which was awarded by the Department for the Environment, Food and Rural Affairs (Defra), will be used to restore the traditional habitat, in part by bringing back beneficial farming methods along more than 30 kilometres of river.
Geoff Sansome, the regional manager for Defra's rural development service, said decline in the number of fish has had a knock-on effect.
"Over the last 30 years, the fall in trout and grayling stocks in the Monnow and its tributaries has been marked by a decline in other important species, including otters, water voles and native crayfish.
"(The project) will require the support and assistance of around 90 farmers and landowners.
"The work includes coppicing riverside trees and the fencing of banks to stop access by livestock.
"This should reduce silt levels in the water along some 30 km of river, which will significantly improve water quality.
"We hope that the result of all the effort will be a much better habitat for wildlife."