A major project is starting to secure the future of ospreys and rare fish at Bassenthwaite Lake, in Cumbria.
Lake Bassenthwaite is home to rare species of fish
Ospreys have proved a regular treat for birdwatchers at Bassenthwaite over the last four years.
But environmentalists say pollution, too much silt entering the waters and invading fish and plant species could harm existing wildlife.
Work will be carried out to clean up Bassenthwaite Lake before being extended to all lakes in the region.
Lake Bassenthwaite is a designated Site of Special Scientific Interest and National Nature Reserve.
The Environment Agency, English Nature, the Forestry Commission, the National Trust and United Utilities water company are involved in the restoration project.
"Bassenthwaite was chosen because it was the one that required priority attention.
"We are looking carefully how we perform and how we achieve our objectives because this will be a template for how we address other lakes.
"There are 19 large lakes and numerous small tarns and they all have to have the level of protection so that we retain these lakes for future generations."