Detected mercury pollution in the deepest part of the ocean

Chinese submersibles discovered large amounts of mercury accumulated in the deepest parts of the ocean, including the Mariana Trench.

The study, published last week in Proceedings of the National Academy of Sciences of the United States of America (PNAS), was carried out by Shanghai Ocean University, led by expert Xu Yunping, in collaboration with international collaborators. .

Using a remote-controlled diving device developed by the Hadal Science and Technology Research Center of Shanghai Ocean University, the researchers collected numerous sediment samples from the Hadal region, also known as the Hadal region. The so-called dark seas, including the deepest trenches of the ocean from 6,000 to 11,000 m above the sea surface, including the Mariana Trench.

A Chinese deep-sea submersible returns from a Pacific expedition.

Sample analysis shows that the Hadal region is accumulating mercury at a remarkably high rate, greater than the global deep-sea average. Most mercury comes from the surface ocean.

The study also showed that mercury concentrations in the core regions of the trench tended to increase rapidly from before 1900 to after 1950. The main reason was due to mercury emissions from anthropogenic sources into the sea.

The Hadal Zone is a major reservoir of ocean mercury and may play an important role in regulating the global biochemical cycle.