Yorkshire's River Cock is set once again to become a breeding ground for salmon.

The river is a tributary of the River Wharfe and flows between Leeds and Tadcaster.

It was named after the term for a mature salmon and was once an excellent spawning ground for both salmon and trout.

Now the Environment Agency is attempting to reverse the toll taken by industrial pollution which has seen the fish disappear.

Healthy fish

The agency is putting in small weirs, installing suitable spawning gravel and removing debris, including burnt out cars.

Improvements are also being made at the confluence of the Wharfe to enable fish to move more easily between the two rivers.

Chris Wilcock from the Environment Agency said: "Although the River Cock has quite a healthy fish population, in some sections the potential is limited.

"It will take some time but hopefully the river will once again have the numbers of salmon for which it was once known."