Experts and authorities in Ho Chi Minh City are concerned over the mass fish deaths occurring in an iconic canal following unseasonal rains.
The phenomenon has been happening for years along the Nhieu Loc- Thi Nghe Canal, typically at the beginning of the annual rainy season, though unseasonal downpours earlier this month seem to have had the same fatal affect on the canal’s marine life.
Though the reason behind the phenomenon has already been determined, a variety of proposed solutions has failed to bring about a permanent fix.
According to an employee at the Ho Chi Minh City Urban Environment Company, downpours at the beginning of April left hundreds of kilograms of dead fish floating in the canal.
Along several sections of the waterway, bubbles pop along the water’s surface, indicating a release of toxic gas from the mud layering the bottom of the canal, a hazard previously identified by that the municipal Department of Agriculture and Rural Development.
The most serious mass death was recorded on May 17 and 18, 2016 with over 70 metric tons of fish being killed.
Doctor Vu Cam Luong, a local expert, attributed the problem to sudden changes to the canal’s marine environment at the beginning of the rainy season.
Luong’s recommended solution is to lower the amount of tilapia living in the canal by 30 percent to balance the habitat.
Pumping machines should also be installed under the water’s surface to increase the oxygen available to the fish, he explained.
However, Luong’s approach is considered to be very costly, a local official said, adding that the solution would come with a VND130 billion (US$5.7 million) price tag.
According to Vo Thi Mong Thu, an official from the city’s agriculture department, a plan to actively cope with the situation has been developed and evaluated by relevant agencies and is in the process of being approved by the municipal People’s Committee.
Regarding the application of zeolite chemical substance to absorb the toxic gas, Thu stated it was a passive measure and only recommended for closed lakes.
For a permanent solution, regular dredging should be carried out prior to the rainy season to remove the toxic mud layer.
Tran Van Giau, director of the Ho Chi Minh City Inland Waterway Administration, stated that a dredging plan would be submitted to the municipal Department of Transport next week.