Is the Bohai Sea very polluted? What are the causes of pollution?

The Bohai Sea is the most polluted and experts warn that it will become a "dead" sea in 10 years.

According to the People's Daily, according to recent monitoring, the Bohai Sea is still the most seriously damaged sea area in China's marine ecological environment, and a large number of land-based pollutants such as industrial wastewater, domestic sewage, industrial and domestic waste, pesticides, and fertilizers are discharged into the sea in excess of the standard, which has become the fundamental reason why the current deterioration of the Bohai Sea's environmental situation has not been curbed.

Marine experts point out that if nothing is done to curb pollution, the Bohai Sea will become a "dead" sea in 10 years. Even if not a single drop of sewage is discharged into the Bohai Sea now, it will take at least 200 years to restore cleanliness by exchanging water with the outside world.

According to reports, from 2001 to 2005, the total area of polluted sea areas in the Bohai Sea has fluctuated between 10,000 and 10,000 square kilometers, accounting for 24%-41% of the total area of the Bohai Sea. Monitoring by the State Oceanic Administration shows that the most prominent environmental problem in the Bohai Sea is land-based pollution. Every year, 100 million tons of sewage are discharged into the Bohai Sea on land, accounting for the whole country; The main pollutants enter the sea 2.16 million tons every year, accounting for the country's total.

As a result, the coastal pollution of the Bohai Sea is serious, the ecological environment has deteriorated, and the biological resources have been sharply reduced, and the sea areas near individual sewage outlets are almost devoid of life. In particular, the discharge of some sewage outlets has exceeded the standard year after year, resulting in the area of the four categories of water quality and the four categories of inferior water quality in the coastal waters remain high, which has been maintained at about 5,000 square kilometers.

According to the staff of the Beihai Branch of the State Oceanic Administration, in the supervision and monitoring data of 112 sewage outlets in the Bohai Rim region, 70% of the sewage outlets are set up in accordance with marine functional zoning, and are distributed in marine aquaculture areas, tourism areas and protected areas; Occupy only in the sewage discharge area; 81% of sewage outlets illegally exceed the standard.

According to statistics, land-based pollutants entering the Bohai Sea account for the pollutants in the Bohai Sea, and the main channels of pollutants entering the sea are rivers and sewage rivers. At the same time, a variety of persistent and highly toxic pollutants are discharged into the sea. The State Oceanic Administration's monitoring of the environmental priority control pollutants in the water of key sewage outlets shows that the sewage of key sewage outlets.

Six. Six. 6. The detection rate of DDT is 100%. Concentrations of silver, copper, nickel, lead and zinc in the effluent entering the sea from some outfalls have exceeded the threshold for acute or chronic biotoxic effects. Persistent and highly toxic pollutants monitored at key sewage outlets directly endanger the safety of marine ecology and can enter the human body through the food chain, thereby endangering the health and life safety of the public.

Relevant experts believe that the Bohai Rim region is industrially developed and densely populated, and that billions of tons of industrial, domestic, and municipal sewage and tens of billions of cubic meters of river runoff discharge millions of tons of pollutants into the coastal waters of the Bohai Sea every year are discharged uncontrollably, and this land-based sewage discharge directly leads to serious environmental pollution in the coastal waters of the Bohai Sea. As the only semi-enclosed inland sea in China and one of the typical enclosed seas in the world, the Bohai Sea's own weak water exchange capacity is simply unable to dissipate such a huge land-based source of sewage pressure.

If you look at the map, you can see that the passage between the Bohai Sea and the open sea is narrow, resulting in a small exchange of internal and external water, and the pollutant substances discharged into the Bohai Sea will accumulate more and more.

But we have to see that the huge ocean, with an area of 10,000 square kilometers and a water volume of 1,730 cubic kilometers, is actually polluted, and it is not an easy task. Huge area, huge capacity, as long as you do things well on the shore, what pollution in the sea needs you to control? In this sense, pollution control in the Bohai Sea is actually very easy.

To put it simply, if the water of the inland sea does not flow out, it cannot be circulated.