Prime Minister Nguyen Xuan Phuc yesterday asked Hanoi People’s Committee to handle the West Lake mass fish death incident, of which fish losses have already reached 60 tonnes and counting.

PM Phuc also ordered district authorities to work with water service agencies to inspect all lakes in the city and report their findings to the Government.  

Hundreds of soldiers were deployed to the lake yesterday to help urban environmental staff and residents remove the dead fish.

Most of the fish were retrieved as of yesterday evening, reported a Vietnam News Agency reporter at the scene.

The fish deaths reportedly began on Saturday night, leaving the lake surface covered with a layer of floating dead fish. Authorities are yet to determine the cause of the phenomenon.

A preliminary report from the city People’s Committee said an initial quick test conducted on Sunday showed the oxygen level of lake surface water measured zero.

"All the dead fish in the lake died between Saturday and Sunday," Hanoi People’s Committee Chairman Nguyen Duc Chung told the press yesterday during his trip to the West Lake.

"After the city administration took prompt action to provide oxygen for the lake, the die-off ended."

In an early attempt to fix the situation quickly on Sunday, the Hanoi  administration directed the Hanoi Urban Environment Ltd, Co to install 20 aeration devices to provide oxygen to save fish in the lake, with the company’s staff working overnight.

The company director Nguyen Huu Tien said the company also sent 50 employees to remove dead fish and 20 trucks to transport the dead fish to the Nam Sơn Waste Treatment Complex for treatment as per regulations.

The city subsequently ordered authorised agencies to use RedOxy-3C, a substance manufactured in Germany to treat surface water and ground water.

In the meantime, health department staff were dispatched to spray chemicals to sterilize areas around the lake.

Environmental police also took samples of the dead fish and lake water to conduct tests.

The city administration has warned residents not to eat fish from West Lake until authorised agencies issue their final conclusions about whether or not toxic substances are present in the dead fish. 

Oxygen depletion causes fish deaths in West Lake

Oxygen depletion is allegedly responsible for killing tonnes of fish in West Lake since Saturday night in Hanoi.

Nguyen Ngoc Ly, director of the Centre for Environmental and Community Research, said algal blooms in the hot weather and water pollution [caused by household wastewater discharged into the lake] were suspected to be behind the fish deaths.

When algae died, the decomposition used oxygen in the water that is vital for fish. Small fish, in particular, were unable to survive due to the sudden decrease in oxygen, she added.

In response to the situation, the Hanoi administration yesterday quickly directed the Hanoi Urban Environment One Member Co Ltd to install 20 aeration devices to provide oxygen to save fish in the lake, with the company’s staff working overnight.

Until last night, it was estimated that some 10 tonnes of dead fish had been salvaged. This morning too, dead fish has been still found.

VNS