A LAKE District scientist has again been sharing his expertise on water quality during his fifth visit to China.

Professor Gwyn Jones travelled to the industrial city of Shijiazhuang to teach

students the basics of fresh water physics, chemistry and biology, and to explain the importance of microbes in improving water quality.

Prof Jones has contacts with the Institute of Agricultural Modernisation which has been charged with solving water quality problems in the region, particularly the gross sewage pollution of the City River, and the nutrient enrichment of the massive Dalangdian Reservoir.

The retired director of the Freshwater Biological Association at Ferry House, Far Sawrey, was sponsored by the British Executive Service Overseas, a charity offering professional advice to less developed countries, and the Society for General Microbiology, which gave £3,000 towards textbooks and kit.

Students' imaginations were captured by case studies including phosphorus stripping in Windermere to reduce algal blooms, and the use of bacteria to control insect pests such as the Blandford fly in Dorset.

After his return from China, Prof Jones received good news from Yangzhou in China, which he visited late last year.

His advice on cleaning up the Slender West Lake, a beautiful tourist area near Shanghai, has already been acted upon thanks to television publicity during the trip.

A wetland has been created to purify incoming water, and plans are in hand to extend the botanical gardens surrounding the lake.

Prof Jones said the authorities had asked him to go out again in mid-summer to devise a way of monitoring progress, and said none of this would have been possible without the expertise he gained during his 30 years at Ferry House.

Prof Jones said he was looking forward to returning to China, and would be taking with him the new book by Professor Alan

Pickering, also of Ferry House, which explains how phosphorus stripping helped to clean up Windermere.