Mercury sinks deep into marine trenches

Abstract

Marine trenches contain some of the most remote ocean habitats. The ecosystems along the bottom of these V-shaped chasms , which lie as far as 11 km below the surface, thrive on dead organisms and particulate matter funneled down from above. A new study finds that mercury pollution has reached these previously unplumbed depths. Researchers led by Xuejun Wang of Peking University and Yunping Xu of Shanghai Ocean University found high concentrations of mercury and methylmercury in shrimp-like amphipods collected from the bottom of three deep-sea trenches ( 2020, DOI: ). Average methylmercury concentrations in the amphipods were about three times as high as amphipods from freshwater environments. The average total mercury level was more than seven times that of amphipods off the coast of New Jersey, one of the most industrialized and highly populated areas in North America. Coauthor Wenjie Xiao says such high contamination might be common throughout