In coastal areas, there are many petrochemical, metallurgical and pharmaceutical plants, and their sewage often contains more toxic heavy metals such as mercury, cadmium, copper and lead. Some coastal thermal power plants also rely on coal, a large number of emissions of sulfur dioxide. All these have caused serious pollution to the sea.
About 6 million tons of oil and petroleum products enter the ocean each year by various means. Massive oil pollution has led to the death of a large number of organisms due to lack of oxygen. Film and lumps of oil can stick to large numbers of young fish and eggs, killing them. The damage to the Marine environment, as well as plastic bags, oil bags, pesticides and even cigarettes in our daily life, must not be underestimated.