China's largest freshwater lake has shrunk to its smallest size in years due to drought, state media and officials said Thursday, endangering the ecology in the area and fishermen's livelihoods.

After a dry spell of more than a decade, Poyang Lake in east China's Jiangxi province is drying up fast as scant rainfall has sent water levels in the Gan River -- which feeds the lake -- to record lows, the Xinhua news agency said.

The lake's area was 183 square kilometres (73 square miles) Thursday, an official at the local hydrological bureau told AFP -- nearly half the average of 344 square kilometres recorded each year on this day since 1951.

"This year's level is very low," the official said, asking not to be named, adding there had been 65 percent less rainfall in the area since December compared to the average recorded at the same period over the past 60 years.

As large as 4,500 square kilometres when at full capacity -- more than six times the size of Singapore -- the lake is home to the migrating Siberian crane in winter and to a rare finless porpoise all year round.

The long drought has left many of the lake's 10,000 fishing boats stranded in shallow waters.

China is regularly affected by crippling dry spells. Last spring, authorities said a drought along the Yangtze river had affected more than 34 million people, leaving livestock without water and parching a major grain belt.

In December, Outlook -- an official Xinhua news agency weekly -- quoted the Yangtze Water Resources Commission as predicting an ongoing drought in the lake area and warning of a threat to the local ecology and economic development.

Citing local officials, the report said low water levels and a fishing ban in March and April implemented in 2002 had reduced the fishing season to three months a year, threatening local fishermen's livelihoods.

The annual per capita income of fishermen in Poyang Lake fell to 1,000 yuan ($160) in 2011 from as much as 4,000 yuan in previous years, state media has said.

Meanwhile, dwindling fish stocks will also affect the lake's half-a-million migratory birds, which will lose their source of food, Xinhua said.

Authorities plan to try and resolve the problem by putting 165 million fry into the lake, it added.