Molecular composition of organic matter controls methylmercury formation in boreal lakes.

ABSTRACT: A detailed understanding of the formation of the potent neurotoxic methylmercury is needed to explain the large observed variability in methylmercury levels in aquatic systems. While it is known that organic matter interacts strongly with mercury, the role of organic matter composition in the formation of methylmercury in aquatic systems remains poorly understood. Here we show that phytoplankton-derived organic compounds enhance mercury methylation rates in boreal lake sediments through an overall increase of bacterial activity. Accordingly, in situ mercury methylation defines methylmercury levels in lake sediments strongly influenced by planktonic blooms. In contrast, sediments dominated by terrigenous organic matter inputs have far lower methylation rates but higher concentrations of met

SUBMITTER: Bravo AG 

PROVIDER: S-EPMC5309796 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature