The presence of mercury in the world’s oceans has ramifications for human health and wildlife, especially in coastal areas where the majority of fishing takes place. But while models evaluating sources of mercury in the oceans have focused on mercury deposited directly from the atmosphere, a new study led by Peter Raymond, professor of ecosystem ecology at the Yale School of the Environment and published in Nature Geoscience shows that rivers are actually the main source of the toxic heavy metal along the world’s coasts.
“It kind of rewires the global mercury cycle,” Raymond says. Previously, it was believed that most mercury in the open ocean was deposited there from the atmosphere, and then made its way into coastal areas. But now it appears that most mercury flows into the coastal ocean areas from rivers, and from there it moves out into the open ocean.
“Currently, policymakers mainly focus on controlling atmospheric emission and deposition of mercury, while the contribution of river mercury to coastal oceans is not well understood,” says Maodian Liu, a postdoctoral fellow in Raymond’s lab. He says that the new findings underscore the importance of limiting the mercury that makes its way into rivers.
Read more at: Yale University
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