There are a lot of dead fish in Shuangyuewan Beach, Guangdong Province. What caused it? There are bigger hidden worries behind it.

Last month, a large number of dead salmon and sea urchins appeared on the coast of Hokkaido, Japan. After accident investigation, it was confirmed that the death of these creatures was caused by red tide in the ocean. Coincidentally, a large number of dead fish have also appeared on the beach of Shuangyue Bay in Huizhou City, Guangdong Province recently. Witnesses recorded this scene and posted it on social platforms, which attracted a lot of attention. Judging from the content of the video, there are indeed many silver-white dead fish on the beach, which are lined up on the coast for hundreds of meters.

Shuangyuewan Beach is a famous tourist attraction in Guangdong. After this kind of thing appeared, the local tourism management department immediately sent staff to the scene to investigate and deal with it. Later, a reporter went to the scene to interview and saw that sanitation workers were already dealing with dead fish. So what are these fish? Why did a large number of people die on the beach? How to avoid this phenomenon from happening again?

The management committee of Shuangyuewan Scenic Area reported the news to the local marine and fishery comprehensive law enforcement brigade, and then the law enforcement brigade sent professionals to the scene for investigation. After professional investigation, it is confirmed that most of the dead fish on the beach are yellow-tailed fish, and other kinds of fish are rarely seen. As for their causes of death, they are still under investigation. There are generally two reasons for the large number of fish deaths, one is environmental pollution, and the other is lack of oxygen in the water.

Environmental pollution is generally caused by improper discharge of industrial wastewater, waste gas, waste residue and domestic sewage in cities, especially if the wastewater is directly discharged into natural water without treatment, heavy metals or compounds in the wastewater will directly pose a life threat to aquatic organisms, and then a large area of death will occur. Hypoxia of water body is one of the consequences of environmental pollution, and red tide is one of them.

The chemicals in the sewage make the algae in the water grow wildly, and most of them float on the water surface, blocking the sunlight from entering the water. On the other hand, the growth of algae needs to consume a lot of oxygen, which is more than the oxygen produced, leading to hypoxia in water, which will lead to suffocation of fish. If there is water pollution or lack of oxygen in the waters of Shuangyue Bay, why are most of the dead fish yellow-tailed?

Yellow-tailed fish is a common fish in the Yangtze River basin and south of the Yangtze River basin in China, and it is a kind of freshwater fish with strong adaptability. The body structure of yellow-tailed fish has one characteristic. The cutin on the edge of its mandible is developed, which can help the yellow-tailed fish get more food, but it is also easy for the yellow-tailed fish to consume more water pollution. So some people think that food poisoning is the cause of a large number of deaths of yellow-tailed fish.

In addition, the oxygen content in Shuangyue Bay is indeed likely to decrease, and yellow croaker is a kind of fish that is sensitive to oxygen content. When the oxygen content in water changes greatly, yellow croaker will die of lack of oxygen.

If individuals find a large number of dead fish on beaches, lakes and rivers, the first thing to do is to report the situation to the relevant departments and hand over the professional matters to the relevant departments for handling. Secondly, people should not think that they can "Bai Piao" just by seeing a lot of dead fish. The cause of death of these dead fish is unknown, and there is likely to be food safety problems. Therefore, after the dead fish incident in Shuangyue Bay, local law enforcement officers advised the public not to pick up dead fish to eat.

After professionals from relevant departments arrive at the scene, they usually take samples of dead fish and send them to the laboratory for testing. This process can usually judge whether dead fish are seriously polluted. Secondly, professionals will also sample the waters near the dead fish and then send them to the laboratory for testing to further determine the cause of the accident. After professional sampling is completed, on-site law enforcement officers can carry out harmless treatment of dead fish, including deep burial, centralized high-temperature treatment and centralized high-concentration disinfectant treatment.

In addition to finding out the causes of a large number of fish deaths and handling the dead fish, the staff should also carry out post-work according to the causes of death to avoid the recurrence of dead fish. If fish die because of lack of oxygen, but there is no red tide or other water pollution in the sea area, then people can be arranged to clean up the algae on the seabed, or oxygen-making equipment can be added at the seaside, which is beneficial to improve the oxygen content in the water.

abstract

In fact, this is not the first time that a large number of fish have died in South China in the past two years. In August last year, a large number of dead fish also appeared on the beach of Hailing Island in Yangjiang, Guangdong. In September, a 4-kilometer-long "dead fish line" appeared in Yintan Scenic Spot in Beihai, Guangxi. If the problem of environmental pollution is ruled out, then the death of these fish may be related to deeper factors, such as global ocean change.