Abstract

Neurotoxic methylmercury (MeHg) formed from inorganic divalent mercury (HgII) accumulates in aquatic biota and remains at high levels worldwide. It is poorly understood to what extent different geochemical Hg pools contribute to these levels. Here we report quantitative data on MeHg formation and bioaccumulation, in mesocosm water-sediment model ecosystems, using five HgII and MeHg isotope tracers simulating recent Hg inputs to the water phase and Hg stored in sediment as bound to natural organic matter or as metacinnabar. Calculations for an estuarine ecosystem suggest that the chemical speciation of HgII solid/adsorbed phases control the sediment Hg pool's contribution to MeHg, but that input of MeHg from terrestrial and atmospheric sources bioaccumulates to a substantially greater extent than MeHg formed in situ in sediment. Our findings emphasize the importance of MeHg loadings from catchment runoff to MeHg content in estuarine biota and we suggest that this contribution has been underestimated.

Published in

Nature Communications
2014, Volume: 5, article number: 4624

SLU Authors

• Skyllberg, Ulf

  • Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
    

• Nilsson, Mats

  • Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

SDG6 Ensure availability and sustainable management of water and sanitation for all
SDG14 Conserve and sustainably use the oceans, seas and marine resources for sustainable development


UKÄ Subject classification

Forest Science


Publication identifier

DOI: https://doi.org/10.1038/ncomms5624

Permanent link to this page (URI)

https://res.slu.se/id/publ/60409