Sightings of blue-green algae in reservoirs in Guangdong Province have put local authorities
on high alert to ensure the scourge does not contaminate the water
supply, as it did this summer in Taihu Lake in Jiangsu Province.
"Blue-green algae has been seen in more than 20 reservoirs in the
province," Li Yue'an, vice-director of the Guangdong water resource
department, said at a water resource conference in the city of
The algae comprise microscopic organisms that are naturally
present in lakes and streams. Scientists have said they grow easily
in polluted waters and an excess of them can starve the water of
oxygen, killing fish and other aquatic life.
Li said if there is an outbreak of the algae in Guangdong, the
effect will be worse than it was in Taihu Lake because of the
higher temperatures and stronger sunlight in the province.
He did not say which reservoirs had been hit by the algae
Officials from the Guangzhou water resource bureau said the
algae had not yet been detected in the city, the provincial
capital. They said Guangzhou's rivers flow very fast, which helps
counteract the growth of the algae.
Some experts have said it is unlikely Guangdong will witness a
large-scale outbreak of the algae.
Li Jianji, director of the Guangzhou Astronomy Society, said
yesterday that the region's Pearl River experiences at least two
tides every day, which maintain the steady flow of the river and
Blue-green algae can only become abundant in relatively still
water, he said.
The tides also carry large numbers of freshwater and saltwater
fish to the mouth of the Pearl River, which eat the algae, he
"The river will not see an outbreak of blue-green algae in the
next 10 years," Li said.
Han Boping, a hydrobiology professor at the Guangzhou-based
Jinan University, who has studied the blue-green algae in the
province for many years, said that local people and the authorities
must, however, be on the alert for the algae once spring approaches
and brings with it warmer temperatures.
He said the government should take measures to control pollution
in rivers, lakes and reservoirs before the weather gets warmer.
In May, a blue-green algae outbreak hit Taihu Lake, affecting
the water supply to thousands of people in Wuxi.
( China Daily
December 28, 2007)