China: Algae Threatens Water Supply

Jun 26, 2007 05:19 AM EDT

Beijing(AP)- Bluegreen algae has emerged on another of China's large inland lakes, threatening water supplies for millions of local farmers, an official said Tuesday.

"The Dianchi Lake now looks like green paint," said a press officer with the government bureau in charge of the lake. Like many Chinese officials, he would only give his surname, Zhao. The massive freshwater lake lies near Kunming, the capital of China's southern Yunnan province.

Zhao said the outbreak began in May and was thought to be caused by hot weather. However, he also said the lake has been badly polluted by local industries and sewage discharge over the last several years.

He said Dianchi is among the country's most polluted lakes and is similar in quality to Lake Tai, which last month also suffered an algae bloom that forced 5 million residents of the country's eastern lakeside city of Wuxi to drink and bathe with bottled water.

Foul-smelling algae outbreaks on Dianchi Lake have occurred every year since the 1990s, he said. This year's bloom seemed to cover a smaller area than previous years, Zhao said, but was he unable to give specific measurements.

Yunnan's Life Express newspaper quoted a resident identified only by his surname, Zhang, as saying the bloom was worse then in recent years.

The paper also quoted another resident surnamed Li who said the algae was deadly to aquatic life and very corrosive.

"Where there is algae, there is no fish or shrimp. Ship paint also peels off because of the algae," Li told the paper.

Local residents in Kunming mainly rely on a separate Zhangjiuhe reservoir for their drinking water, but Zhao said that factories and millions of farmers still use Dianchi's water for industrial use and for watering crops.

Officials were using boats equipped with pumps that push the lake water through filters to try to get rid of the bloom, Zhao said.

Blue-green algae, a plant-like organism, blooms when nutrients sometimes caused by excessive pollution build up in water. Some algae can produce dangerous toxins and if ingested can cause vomiting, respiratory failure and, on rare occasions, death.