Mass fish death in Hanoi’s West lake due to oxygen depletion

By the afternoon of the October 3rd, Hanoi’s environmental workers fished out 60 tons of dead fish in West Lake, the largest lake in Hanoi. Oxygen depletion is allegedly responsible for the mass fish death.

A man salvages dead fish bodies at the Ho Tay (West Lake) in Hanoi on October 2, 2016 (Photo: tuoitre)

Nguyễn Ngọc Lý, 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 Hà Nội administration yesterday quickly directed the Hà Nội 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.

Nguyễn Hữu Tiến, director of the company, said the company also sent 50 employees to remove the dead fish and 20 trucks to transport the fish to the Nam Sơn Waste Treatment Complex for treatment according to regulations.

Environmental police have also taken samples of the dead fish and the lake’s water to conduct tests.

The city administration has warned residents to avoid eating the dead fish until authorised agencies issue the final conclusion of whether or not toxic substance is present in the dead fish./.

VNF