On September 15, the Department of Agriculture and Rural Development of Quang Ngai province sent a report to the People's Committee of Quang Ngai province on the results of water quality monitoring and the assessment of the cause of fish deaths on the Tra Khuc River.
According to Mr. Nguyen Duc Trung - Deputy Director of the Department of Agriculture and Environment, from September 6 to September 8, in the area of the North bank of the Tra Khuc River, the section from Tra Khuc 2 bridge to the upslope dam downstream of the Tra Khuc River, belonging to Truong Quang Trong ward, there is a phenomenon of fish death concentrated in low-lying holes, small ponds and sand trenches on alluvial grounds along the river.
Through actual inspection on September 8, it was recorded that dead fish were concentrated mainly in isolated water areas with low water levels and small areas. The main dead fish species are tilapia; in addition, there are some other aquatic species such as shrimp and snails.
No widespread fish deaths were recorded at the main flow of the Tra Khuc River. In adjacent water areas, fish still lived normally, and no signs of aquatic diseases were detected.
The Department of Agriculture and Rural Environment assessed that fish deaths occur locally in low-lying holes, sand trenches and small ponds formed on alluvial grounds along the river after the water level of the Tra Khuc River dropped.
Before the incident occurred, the upstream area of the Tra Khuc river upstream and downstream dam was maintained at the water level to serve the trial operation of the project and create landscape; then, the valve gates were opened to bring the flow back to its natural state. The rapid water level retreat has caused a number of fish to be isolated in water holes and low-lying areas that are no longer connected to the main flow.
In hot weather conditions, low water levels, small water volume and poor water exchange, isolated water holes reduce local environmental quality, leading to fish dehydration, local oxygen deficiency and death.
The results of monitoring and analysis showed that the surface water quality in the inspection area basically met the requirements according to QCVN 08:2023/BTNMT (Level B) for typical physico-chemical indicators; no signs of serious water environment pollution that could cause mass fish deaths were detected.
Therefore, the above-mentioned fish death phenomenon is mainly identified as a consequence of fish being trapped in isolated low-lying water areas when river water levels drop, not a water environmental pollution incident throughout the river section.
As Lao Dong Newspaper has reported, from September 6 to September 8, the mass fish deaths on the Tra Khuc River, the section from Tra Khuc 2 bridge to the upslope dam downstream of the Tra Khuc River, Truong Quang Trong ward (Quang Ngai), have caused stench, affecting the environment in residential areas living along both banks of the river.
Previously, on September 4, the Department of Agriculture and Rural Development of the province released hundreds of kg of fish seeds into the Tra Khuc River to regenerate aquatic resources after the riverbed was waterlogged.
