Authorities in eastern Zhejiang Province began on Monday releasing algae-eating fish into Taihu Lake, China's third largest freshwater lake, to curb the rampant algae growth.

In the next few days more than 20 million fish, mainly silver carp fry, would go into the 2,400-square-km lake in Huzhou in Zhejiang as well as in Suzhou, Changzhou and Wuxi in neighboring Jiangsu Province, said Lin Jianhua, director of the Taihu Lake Fishing Administration.

A silver carp weighing 1.5 to 2 kg could consume 50 kg of algae during its lifetime. Many of the fish released were expected to be of this weight by September this year, Lin said.

The local government began to use silver carp to clean the lake in February last year after blue-green algae choked the lake in 2007 as a result of pollution. The algae had affected the drinking water of 17 million residents, Lin said.

"The fish and shrimp we caught in recent years weighed much less and were smaller than before," said Qian Fenglin, a 42-year-old fisherman.

The fish were bought using government funds and public donations.

By Sunday, people in Jiangsu, Zhejiang and neighboring Shanghai Municipality had donated about 600,000 yuan (87,800 U.S.dollars), which bought 1.02 million silver carp fry, Lin said.

The donation campaign was initiated on Jan. 20 by 20 local media organizations.

"When I was young, Taihu Lake was clean. But its water quality deteriorated several years ago," said Zhao Meizhen, a 90-year-old retired teacher who bought 500 fry from Shanghai.

In 2009, the local government bought more than 14 million silver carp fry and donors bought 1 million.