(Xinhua)
Updated: 2007-09-04 16:11

"It is very hard to restore a damaged lake's ecological environment in a very short period of time, but success is not mission impossible if concerted efforts can be made over dozens of years, " said Yu.

The scientific team led by Yu has built a resource bank and a database of more than 150,000 aquatic weed samples collected in the past 25 years.

"I believe the growing of aquatic weeds is a cost efficient method to prevent ecological degradation of lakes and there are no technical barriers in this regard," said Yu.

There are more than 20,000 natural lakes across China, of which 2,800 measure at least one square kilometer.One thousand lakes have disappeared from Chinese territory in the past 50 years, according the State Environmental Protection Administration of China.

Many of the country's lakes have been ridden by pollution. The Taihu Lake drainage area is situated in one of the most densely populated regions in China and receives 56 billion tons of sewage discharge each year.

However, about 30 million people rely on Taihu Lake, China's third largest freshwater lake, for drinking water, including nine cities in the provinces of Jiangsu and Zhejiang as well as Shanghai Municipality.

A severe algae outbreak at the end of May rendered tap water undrinkable for a week for half of the 2.3 million residents in Wuxi, a city in eastern Jiangsu Province.

By mid-June, a second algae bloom appeared, covering 800 square kilometers and causing widespread concern in cities around the lake.

Blue-green algae outbreaks have also been reported in the Chaohu Lake in East China's Anhui Province and the Dianchi Lake in southwestern Yunnan Province since May, and have threatened the local tap water supply.

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