UNDERNEWS

Undernews is the online report of the Progressive Review, edited by Sam Smith, who has covered Washington during all or part of one quarter of America's presidencies and edited alternative journals since 1964. The Review has been on the web since 1995. See main page for full contents

May 4, 2009

PACIFIC MERCURY LEVELS COULD RISE 50%

Tree Hugger - According to a new study, if mercury levels continue to rise at the rate they're predicted to rise, the amount of mercury in the Pacific will increase by 50% over the next 40 years. The study also shows just how the mercury in emissions from around the world wind up in the North Pacific Ocean:

"Methylmercury is produced in mid-depth ocean waters by processes linked to the "ocean rain." Algae, which are produced in sunlit waters near the surface, die quickly and "rain" downward to greater water depths. At depth, the settling algae are decomposed by bacteria and the interaction of this decomposition process in the presence of mercury results in the formation of methylmercury. Many steps up the food chain later, predators like tuna receive methylmercury from the fish they consume. . . it appears the recent mercury enrichment of the sampled Pacific Ocean waters is caused by emissions originating from fallout near the Asian coasts. The mercury-enriched waters then enter a long-range eastward transport by large ocean circulation currents," said USGS scientist and coauthor David Krabbenhoft.

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