Thousands of fish have been found dead in Nghia Do Lake in Hanoi over recent days, with the mass die-off producing a strong foul odour that has affected local residents and businesses.
On the morning of June 18, large numbers of fish carcasses were seen floating along the shoreline of the lake, forming dense patches on the water's surface. Fish of various sizes were found in advanced stages of decomposition, causing unpleasant smells to spread throughout the surrounding area.
Environmental sanitation workers arrived at the site from around 5.30 am to collect and remove the dead fish. Using nets and small boats, workers gathered the carcasses, placed them in bags and transported them for disposal.
According to residents living near the lake, isolated fish deaths had been observed several days earlier. However, the number of dead fish increased sharply on June 17.
Despite continuous clean-up efforts, the smell from the decomposing fish continued to spread around the lake. Many people exercising in the area during the morning were forced to leave early or wear face masks while passing through.
Vu Van Tien, owner of a food business on To Hieu Street, said the fish deaths had been occurring for about three days. He noted that similar incidents had happened before, but the scale and odour of this event were far more severe.
Local authorities have not yet announced the cause of the mass fish deaths.