Toxic man-made mercury pollution is discovered in the deepest part of the ocean

Toxic man-made mercury pollution has been discovered in the deepest part of the ocean, in the Marianas Trench -- more than six miles below the surface. Researchers from China and the US used submarine robots to identify mercury in the fish and crustaceans living in the deepest part of the western Pacific Ocean. Mercury enters the atmosphere through the burning of fossil fuels, mining and manufacturing. It can then be transported into the oceans via rainfall. The liquid metal -- which was once used in thermometers before being banned -- is highly toxic and can be ingested via polluted seafood.