A school of 200,000 silver carp has been released to help clean up algae in Taihu Lake, the country's third largest freshwater lake, authorities said on March 11.

More than 100 residents, volunteers and fishermen in Suzhou, a city in the eastern province of Jiangsu, released the fish on March 10, the Wuzhong district bureau of agriculture said in a statement.

The fish will not only increase fishery resources, but also clean up the lake, it said.

A silver carp can consume about 42 kg of algae for every kilogram it gains.

The local government began using silver carp to clean the lake in February 2009 after huge clusters of blue-green algae appeared in the lake in 2007 as a result of rampant pollution, affecting the drinking water of 17 million residents.

Since then, about 12 million silver carp fry are released into the 2,400-square-km lake every year.

The water quality in Taihu Lake has been improving over the past several years due to a series of measures, including the biological treatment of algae.