To find out the cause of a large number of dead fish in Tangkeng Reservoir, Dongguan. What is the reason?

There are two reasons for the large number of dead fish in Tangkeng Reservoir in Dongguan. The first reason is that the recent frequent high temperature weather has caused the water in the reservoir to heat up and the fish died of lack of oxygen. Secondly, an alien species called scavenger appeared in the reservoir, which grew wildly in the reservoir, competing for food of the original species, affecting the ecological balance of the reservoir, resulting in a large number of dead fish in the reservoir. After strict inspection and water quality testing, the water center has confirmed that the overall water quality of the reservoir is in a safe state, and the public need not worry too much.

The phenomenon of a large number of dead fish in the reservoir was discovered at the end of August, and nearby residents reported that there were a large number of dead fish in the reservoir, which smelled bad. Through field investigation, the aquatic center cleared about 2.5 tons of dead fish and salvaged nearly 10 tons of scavenger species. However, this does not mean that the problem has been solved, and the subsequent salvage and cleaning work is still going on.

The hot weather causes the water body to heat up and the air pressure to drop, so the solubility of oxygen in water will decrease. At the same time, the vast number of microorganisms in the water will multiply in large numbers, thus consuming oxygen in the water. Coupled with the fish's own activities, it will also consume oxygen, which will eventually lead to the overall lack of oxygen in the water body. This situation is natural selection, and human disturbance may have a negative impact on the whole aquatic ecosystem. However, human beings can still help to increase the oxygen content in water and maintain the survival of fish in some way.

The invasion of alien species can be completely avoided. In order to maintain ecological balance, conservation rules such as reservoirs and fish ponds will stipulate that harmful substances should not be put into water bodies, otherwise the whole aquatic ecosystem will be polluted. Some people don't have a clear understanding of alien species, and they don't know their source and harm, so they release or breed at will. Once there is any problem, it will break the ecological balance and bring irreparable harm. The large area of dead fish in this reservoir is a good example, reminding everyone to pay attention to protecting the ecosystem.

In addition, untreated factory and domestic water discharged into fish ponds or reservoirs will also affect the ecosystem of water bodies, so unnecessary interference to the ecosystem must be avoided.