Foreign media: 200 years ago, stony corals became "new witnesses" of the Opium War

The Reference News Network reported on June 12 that the British fleet had sunk a number of Chinese ships since 1840, first near Hong Kong and later in other places. They forced the Chinese market to open up to the East India Company, the world's largest drug dealer at the time, and what the company supplied became the name of the war — the First Opium War, which the British won and completely occupied Hong Kong.

According to the Austrian newspaper Zeitung on June 7, the naval battles of this war and the Second Opium War shortly thereafter have been documented by British naval painters, but now there are other "witnesses" - they are called bell-shaped coastal corals, a type of stony coral. Their bones are made of aragonite (a calcium carbonate mineral) and other metals such as mercury can replace calcium as its component.

Explosives contain mercury, and the shells fired by the British fleet are no exception. Sun Ruoyu and Holger Hintermann of Trent University measured mercury levels in corals over 200 years and found that mercury was not detectable until the First Opium War, then plummeted, rose further by the history of naval warfare during the Second Opium War, and then soared again by World War II.

Coral mercury levels in many parts of the ocean have plummeted since industrialization began, a background signal that appeared relatively late and weakly in China. (Compilation/Lian Zhao)