Tons of dead fish whiten the regulating lake
In recent days, people living near regulating lakes in Hai Phong City such as Phuong Luu Lake, An Bien Lake... have continuously reported on the situation of dead fish, floating white on the lake surface. On the afternoon of August 19, Lao Dong Newspaper reporters recorded in the Phuong Luu Lake area - the largest regulating lake in the East of the city with an area of 24 hectares. At 3:30 pm, the Phuong Luu Lake area near Vuon Hong cafe, dead fish floated white in one area, with a strong fishy smell. A resident of Phuong Luu 6 residential group, Dong Hai ward - reflected that from 4-5 days now, dead fish have appeared, the number is increasing day by day, the stench and fishy smell cover the entire area. This person believes that the water in the lake may have been polluted.
Also according to households living along Phuong Luu Lake, after the phenomenon of fish deaths occurred, the management unit also arranged workers to pick up fish on the lake surface, but just day after day, fish died again, floating all over. People hope that functional units will thoroughly handle this situation, restore a healthy living space for people to live, exercise, and do sports every day.
Faced with this situation, in an exchange with Lao Dong Newspaper, a representative of Hai Phong Drainage One Member Limited Liability Company said that in recent days, fish deaths have occurred at Phuong Luu, An Bien, Tien Nga, Mam Tom and Dam Huyen lakes. The estimated amount of dead fish is about 3-4 tons.
Urgently overcome and restore the environment of the regulating lake
According to a preliminary assessment by Hai Phong Drainage One Member Limited Liability Company, the phenomenon of mass fish deaths (mainly tilapia) is likely due to prolonged hot weather days causing the surface water temperature to rise, and when encountering sudden thunderstorms, the water environment changes, causing fish to not have time to adapt.
The city's drainage system is mostly a common drainage system for both rainwater and wastewater. When it rains heavily to prevent urban flooding, the discharge gates and spillway to the lake ditch will be opened. Therefore, a part of untreated domestic wastewater will flow into the lake, stimulating bacteria to break down organic matter and consume a large amount of oxygen in the water. Taking water from nearby river mouths to wash water from lake ditches during high tides can suddenly change salt concentrations and can also cause environmental shock to fish.
Along with that, the amount of bottom mud in the regulating lake ditches is thick, creating a suitable environment for algae and disease-causing bacteria to develop, reducing the oxygen concentration in the water. The company takes surface water samples from the lake to analyze and assess the surface water status, the analysis results show that the COD index (the amount of oxygen needed to use chemicals to oxidize all chemical compounds) is exceeding the threshold with a value of 51-55(mg/l) above the reference value of 30 (mg/l)
As soon as mass fish deaths were discovered, Hai Phong Drainage One Member Limited Liability Company mobilized all manpower to work through noon, overtime in the evening and all day Sunday to thoroughly recover dead fish at regulating lakes. Fish are gathered in boxes with lids and transported on the same day to minimize environmental pollution.
Workers also sprinkle lime powder for disinfection at embankments, fish gathering areas, tanks for dead fish, strengthen environmental sanitation, and wash water from regulating lakes. Along with that, strictly implement the management and operation of regulating lakes and tide control culverts according to regulations, ensuring the correct function of regulating lakes and drainage ditches, and ensuring environmental sanitation at regulating lakes.
