At present, in general, China's marine environment is basically in good condition. But in some bays, rivers and local waters, such as Dalian Bay, Liaohekou, Jinzhou Bay, Bohai Bay, Laizhou Bay and Jiaozhou Bay, etc. are more serious; some marine aquatic resources have declined, and the catch is reduced, a few Precious sea products are damaged, and some marine aquatic resources have been affected; some beaches are damaged, and the coastal environment is damaged. As far as sea areas, the contamination along the Bohai Sea is more polluted, and the East China Sea and Huanghai, the South China Sea is contaminated, and it is basically normal.
Currently, pollution and harm the factors in China's marine environment include the following aspects:
1, land source pollutants. 2. Contaminants emissions from ships. 3, pollution in marine oil exploration and development. 4, artificial dumping waste pollution. 5. Unreasonable marine projects and marine development make some deep water ports and channel deposits, and local waters are destroyed.
There are more than 200 main pollution in China, there are more than 100 main pollution in the coast of China, and there are more than 100 coasts along the Yellow Sea, around 100 in the east and Nanhai. These pollution sources are discharged into the main pollutants of the sea, petroleum hydrocarbons, heavy metal pollutants and organic contaminants. River carrying is the main way for pollutants into the sea.
Petroleum pollution: There is no pollution along the coast of China. Petroleum is the most income in various pollutants. Petroleum pollution is extremely harmful to marine biological resources, and oil is easy to form a film in water surface, preventing air exchange, and reduces dissolution oxygen in seawater, so oil pollution can cause large area of hypoxia. Oil film, oil blocks can stick a lot of fish eggs and young fish, so asphyxia; can make the ovarficoma deformity, causing fish, and subcounting certain carcinogens.
Heavy metal pollution: mainly refers to mercury, cadmium, lead, and the like. There are more than 60 main pollution in China's coastal mercury, especially in the Yangtze River, Pearl River, Duck Green River, Wuli River, etc. is the main pollution source of mercury. Mercury is the largest in the East China Sea, and the South China Sea and the Yellow Sea, the least in the Bohai Sea. However, the average concentration of mercury is the highest in the East China Sea, the lowest in the South China Sea.
Organic contamination: Oil organic contamination of seawater is usually measured by chemical oxygen consumption (COD). The main organic contamination sources have more than 150 in China. The organic matter entered into the sea in the sea takes more than 7 million tons in a COD. Among them, about 50% of the flow in the East Sea, and the remaining half flow into the Bohai, Huang and South China Sea. The river is also the main way for organic containers into the sea.
In short, oil is the most important pollutant in China, and the nest of the East China Sea and the Bohai Sea is two serious zones in oil pollution. It is not serious from the overall to see heavy metal pollution, but in the northern part of the Liaonong Bay, the duck Green Riverkou and the Pearl River Estate, the concentration is high, should pay attention. As for organic contamination, there is obvious reflection in the Bohai Sea and some bays in China, and the COD value has a trend in the north of south.
