SNH said work on the loch will continue

Algal blooms found on Loch Leven, in Kinross, posed a threat to insects, fish and plant life.

Moves to cut phosphate levels to improve the loch's ecology have been paying off, said environmental body Scottish Natural Heritage.

However, experts warned that there was still more work to do to aid a proper recovery of the loch.

The Loch Leven Catchment Management Plan was launched in 1999 after toxic blue-green algal blooms were discovered on the loch - an internationally important wildlife site

Excessive phosphate in the loch raised nutrient levels, causing algae to cover it and steps had to be taken to improve the water for the local community, the fishery and wildlife.

Levels entering the loch were halved to 10 tonnes a year in 2005, compared with 1985, improving the habitat and food for wildlife.

'Amenity value'

Denise Reed, of SNH, said: "As a result of all the organisations and individuals concerned about Loch Leven working together over the last decade, we are showing that it is practically possible to restore the water quality of the loch.

"It may be many years before the loch is as clean as we would wish but given Loch Leven's international importance as a wildlife site and its amenity value for Kinross, it is important for all of us to put in more effort."

SNH said that due to the efforts of local farmers and others, the largest sources of phosphate release, from operations like woollen mills and sewage works, had been tackled.

Changes in farming practice, SNH said, have also started to reduce soil erosion.