Pollution has been pinpointed as one of the culprits behind the discovery of a large amount of rotting fish in Baiyangdian Lake of north China's Hebei Province after the ice had thawed, the Beijing New newspaper has reported.

The low water level, rotten organic substance underwater, a high density of water pollution, among other factors, led to the death of the fishes, according to the local environmental protection bureau in Baoding.

The State Environmental Protection Administration and Ministry of Agriculture have sent a joint team on March 15 to investigate the cause of the incident. The team has not reported its findings so far.

Fisherman Zhang Hongda has a 9-hectare aquaculture farm. In early January, he discovered dead and stinking fish after breaking the icy surface of the lake.

"Then I was trying to persuade myself that there was still hope, since there has always been some dead fish found in spring," Zhang was quoted by the newspaper as saying.

But till now, all he saw was dead fish floating on the lake.

He collected more than 4,000 kilograms of dead fish in his farm in two days. "There is not one single live fish," Zhang said. He had expected to harvest more than 50,000 kilograms of fish this year.

No statistics about the number of dead fish in Baiyangdian Lake and the economic loss are available yet. But Zhang said this year's loss must be the most serious.

In 2000, the lake experienced a similar catastrophe, resulting in 24 million yuan (US$2.9 million) in economic loss.

According to the investigation of the local environmental protection bureau, water pollution is the major culprit for the death of fish.

Located in the upper reaches of Baiyangdian Lake, Baoding City has 41 papermaking factories. In a recent investigation, 29 factories were found illegally discharging wastewater into the lake, according to Hebei Daily.

The factories did not heed the local government's order that they should improve their wastewater processing facilities.

The city has two sewage treatment plants with a combined daily capacity of 16 tons compared to 20 tons of sewage water produced by both factories and citizens each day.

Baoding plans to invest 8 billion yuan (US$1 billion) in the next 10 years to improve the lake's ecology, using US$96 million in loans from the Asian Development Bank.

(China Daily April 4, 2006)