Mercury Persistent in Ocean and Tuna

"Most people with mercury in their bodies get it from eating contaminated seafood, and, even in small amounts, it can harm the brains of unborn children and have toxic effects on the human nervous, digestive and immune systems... The heavy human toll of mercury poisoning came to public attention after thousands of people came down with neurological and other diseases in Minamata, Japan, after decades of exposure traced to mercury in industrial wastewater that had poisoned local fish... Given the global scientific consensus over mercury’s health risks, most of the world’s countries signed the 2013 Minamata Convention committing themselves to eradicating its use... Yet the new research suggests that the earth heals slowly... [the scientists] specifically looked at tropical tuna — skipjack, bigeye and yellowfin — which make up 94 percent of the global tuna catch. They found that, in contrast to a global decrease in mercury emissions since the 1970s, mercury levels in tuna remained virtually unchanged... Gold mining is now thought to be the world’s largest source of human-caused mercury emissions."