Hypoxia and Water Quality

Have you ever dreamed of swimming in the water without oxygen like marine life? Unfortunately, your dream is moving away from you because of hypoxia. This is because hypoxia worsens the ecosystem by killing organisms in the water and lowering the concentration of oxygen dissolved in the water. And this problem is an increasingly serious trend in advanced countries like China. In particular, as more the city is getting developed, frequency of hypoxia is increasing rapidly, like in the Pearl river, East China Sea, or Min River.

The mouth of the Pearl River meets the South China Sea in southeastern China. Hypoxia has emerged as one of the major environmental problems here every summer due to lights from high-rise buildings such as modern shopping malls and beautiful and luxurious hotels along both banks of the Pearl River. Beautiful and wonderful lights and landscapes have reached a point where the ecological plants living in the river are threatened with their living grounds. It is estimated that about 80 percent of the fresh water emissions of the Pearl River occur during humidity (April-September), and it also carries abundant nutrients and organic matter to the Pearl river estuary. However, the problem begins in the summer (June-August) when the industry of the Pearl River begins to become active (J.X. Wu 2018, p. 2). The original hypoxia is generally controlled by various physical factors mentioned above, such as material transport, but when humans are included there, hypoxia extends further from coastal waters adjacent to the River basin to coastal areas near WanSan Island. If you look at the results of a study of this river, the closer you get to the riverside, the lower your oxygen solubility, and the higher you get to the far center of the coast. And the correlation between these two variables is 0.70 showing a high correlation. People's industrial activity has also resulted in more hypoxia, with water flowing into the river feeding plankton excessively (L. Luo 2009, p. 420). As human activity becomes more active, many coastal and esteemed waters around the world have been supplied with large amounts of nutrients and pollutants, which are expected to not only affect the fisheries industry but also lower water quality and cause a shortage of drinking water due to chemicals.

Hypoxia is also China's East Sea one of the regions is getting worse is being reported. Unlike the United States, which had research data on hypoxia until the '80s and '70s, the river did not realize the seriousness of the problem until the late 1990s and began to study little by little. By the time the research was started, hypoxia had already occurred, and the area was also. After searching for the main cause of this hypoxia, we found that besides the environmental and weather effects, factories around them were also one of the important factors. Most of the factories produce nitrogen or sulfur, which began when it flowed into the river. These chemicals have resulted in rapidly lowering oxygen levels while providing a very good environment for plankton. If you look at the graph, the nitrogen content in the river, which stayed at 200 (10kg7 kg in units) in the 1960s, rose to 600 in a flash in the 70s when China's industry developed rapidly, and reached 800 in the 1990s as if it were on a downward spiral again, and this figure has been rising rapidly so far. For this reason, the Yangtze River Delta, an economic zone, has failed to meet the water quality standards that 80 percent of rivers can drink due to the discharge of large amounts of liquid waste. There is one more reason for hypoxia caused by people, not the substances that enter the water. It is a global warming phenomenon that causes the amount of oxygen in the water to drop rapidly as the temperature of the water rises. The main cause of global warming is human, and among them, human industrial activities can be selected as a representative example. A graph of the rising global temperature anomalies shows that the number that remained stable until the 1950s has more than tripled over the course of 2000.

In the Min River, or the South China Sea, it would be right to say that the problem continues, rather gets worse. The South China Sea is bordered by Fuzhou, a large city known for its farming and maritime projects. First of all, Fuzhou has good conditions for farming, so it has big agricultural projects, but the problem is that when it rains, all the chemicals in the pesticides and pesticides used to farm, all the chemicals on the ground and on the crops will flow into the South China Sea. Most pesticides contain a compound called chlorinated hydrocarbon interties, a combination of carbon, hydrogen and chlorine, which has an indestructible property, which lasts for a long time at the bottom of the soil or river, and is a good food for omnivorous plankton. And this ingredient is included in most pesticides, so the problems caused by pesticides are serious, especially in places where agriculture has developed, such as Fuzhou. To talk about the second marine industry, we should first know why the marine industry has developed. Since ancient China, there have been frequent droughts in the interior of the region, which led people to search for water. As a result, agriculture and maritime industries began to develop together. Due to the fast-developing technology and advanced facilities, many factories are packed in rivers and beaches, and as a result, many people who have flocked to find jobs, as well as their families, are moving to shore, dumping waste water and many chemicals from many factories that do not have clean-up facilities, as well as people who are ignorant of environmental protection, and many of the selfish environmental destruction of those people are making hypoxia worse day by day.

Now, hypoxia, which has emerged as a serious ecological problem around the world, is exacerbated by human selfishness and desire. East China Sea, a busy metropolitan area and near the Pearl River, or Min River couldn't avoid this problem. Human influences have been enormous, from indiscriminate use of pesticides to untreated wastewater to serious global warming. This problem could lead to the death of fish, the destruction of marine ecosystems, the decay of seawater and the lack of food in the future. In order to solve this problem, we need to be a little alert, and I think it's time for a public debate and a lot of countermeasures like global warming, although it's not yet well covered in the news.