According to people's reflections, from the end of December 2025 to the beginning of January 2026, in the sea area of Cay Son lagoon (Thoi Day lagoon), Phuc Tien village, Dam Ha commune, natural dead fish carcasses appeared scattered along the shore.
After receiving information, the People's Committee of Dam Ha commune worked with aquaculture households in the area; received many images and videos provided by people, recording the phenomenon of fish deaths during sea voyages.
Talking to a reporter of Lao Dong Newspaper on January 13, Mr. Nguyen Van Toi (born in 1981, Phuc Tien village, Dam Ha commune) said: From the beginning of January 2026, during the coastal fishing process, he discovered many natural fish species such as snakehead fish, herring, yellow threadfin fish, goby fish... dead and drifting into the net.
Not only him, many other fishermen also recorded similar phenomena, filming videos, taking photos and sharing them on social networks.
According to Mr. Toi, the phenomenon of scattered natural fish deaths has appeared in early 2025; in late 2025 and early 2026, it continued to recur with a higher density.
With experience in the sea profession since childhood, he believes that it is likely related to the use of impurities in the process of raising flower mussels in the area, affecting the natural environment.
In 2025, in this area, the family was assigned water surface to raise caged fish such as song fish and gio fish. Natural fish dying abnormally like this is too worrying. Worrying about the water environment being affected, which could cause damage to the farmed fish herd if local authorities do not soon get involved to clarify the cause and take handling measures," Mr. Toi said.
On January 13, Dam Ha Commune People's Committee coordinated with the Sub-Department of Sea, Islands and Fisheries; Sub-Department of Livestock and Veterinary Medicine (Department of Agriculture and Environment of Quang Ninh province), and representatives of cage fish farming households to organize field inspections in the reflected area.
The working group took samples of seawater, bottom mud and dead seafood samples for analysis and assessment to find the cause of the incident.
According to information from the People's Committee of Dam Ha commune, the locality will continue to closely coordinate with functional agencies to inspect and verify the cause of the incident; when there is an official conclusion, information will be provided to the people. In the immediate future, guide farming households to regularly monitor environmental developments, proactively implement preventive measures to protect the safety of farmed fish in cages.
