Extravagant profits are undoubtedly the root cause of the illegal mining, Fu noted.

Sand, a necessity to build houses, is priced at 20 yuan (3.2 U.S. dollars) to 50 yuan per tonne around Poyang Lake. When it is shipped to Shanghai, the country's economic powerhouse to the east of Jiangxi, however, the sand can sell for as much as 200 yuan per tonne. Because of the huge profits, miners have gone after the "heroin in the water," as it is popularly known among local people around Poyang Lake.

"In response to the booming real estate market, China will raise increasingly bigger demands on sand. Mining sand has become a 'short cut' for many to get rich rapidly," according to Fu.

While bringing sudden and huge profits for some, the unchecked sand mining has posed damage to the safety of dikes, bridges and local ecological environments. It has even threatened the integrity, wild fishery resources and migrant bird food chain of the Poyang Lake wetlands, officials say.

According to a local resident surnamed Ye from Wucheng Town, Yongxiu County, a big sand mining vessel can suck up sand and leave a hollow of 60 meters wide in a river bed in one operation.

To protect Poyang Lake, sometimes known as "China's last lake of clear water," Jiangxi has made extensive efforts to combat illegal sand mining.

On July 1 last year, the municipal government of Jiujiang launched a crackdown on the practice in the lake and branch rivers. It punished 51 offenders and detained 200 vessels. Some 53 percent of the Poyang Lake water area falls within Jiujiang.

However, municipal water police chief Bao Daxin admits Poyang Lake is too large to manage well. It remains hard to put an end to illegal sand mining.

The government must resolve the current problems and eliminate the root causes, officials say.

Combating the building of illegal vessel is believed to be an effective, drastic measure.

On Feb. 3, the municipal government of Nanchang, which borders the lake on its western bank, dismantled 92 illegal sand mining vessels, the largest scale crackdown in recent years.

Fu proposed that the government work out a regulation on watercourse sand mining management as soon as possible to straighten out the system of administration.