BẮC NINH — Oxygen depletion is allegedly responsible for killing tonnes of fish in Bắc Ninh Province’s Cầu River last week.

The dead fish were found from last Tuesday in breeding cages of many households in Cầu River, the section passing through Dũng Liệt and Yên Trung communes, Yên Phong District.

Nguyễn Văn Hợi, head of Yên Phong District’s Division of Agriculture and Rural Development, said a lack of oxygen was initially determined to be the cause of the mass death.

He said the concentration of dissolved oxygen in the water was between 0.85mg/l to 2.35mg/l while the required ratio was 4 mg/l.

According to Hợi, cold air and rain in recent days has affected the environment in fish cages and was not good for the growth of fish.

Agriculture officers recommended the farmers take measures as rain is forecast over the coming days.

An Đình Du, director of Lương Cầm Aquaculture Co-operative in Dũng Liệt, said it was estimated that some 20 tonnes of dead fish had been collected.

Phạm Thị Lý, a farmer from Lương Cầm Village, said she lost four tonnes of fish, costing hundreds of millions of đồng.

She used aeration devices to enhance the water quality in cages but could not keep them alive, Lý said.

Another farmer, Nguyễn Văn Dũng, said about 1.5 tonnes of fish raised in cages died, causing a loss of up to VNĐ100 million (US$4,220).

Director Du said this was the first fish death to happen in his co-operative. He asked the local agency to support farmers suffering from the damage. — VNS