Methylmercury (MeHg) is a neurotoxin and the only mercury (Hg) species that biomagnifies in aquatic biota. Hg is classified as a contaminant of major health concern by WHO and is a leading toxin in the Baltic Sea food web. In the Baltic Sea the ongoing monitoring efforts focus on measuring total Hg concentrations. However, there is no direct relationship between total Hg load to the system and MeHg levels in biota. This disconnect suggests that other important processes control the variability of MeHg formation, bioaccumulation and biomagnification in the Baltic Sea. In this project we use a combination of field work and laboratory and modelling studies to improve our understanding of the impact of eutrophication and climate change on mercury concentrations in the Baltic Sea food web. This project is a collaboration between researchers from ACES, the Baltic Sea Centre, Umeå University, Pau University (France) and Harvard (USA).

Publications so far:
Soerensen, A.L., A. Schartup, E. Gustafsson, B. G. Gustafsson, E. Undeman, E. Björn (2016), Eutrophication increases phytoplankton methylmercury concentrations in a coastal sea – a Baltic Sea case study, Environmental Science and Technology, doi:10.1021/acs.est.6b02717

Soerensen, A.L., A. Schartup, A. Skrobonja, E. Björn (2017). Organic matter drives high interannual variability in methylmercury concentrations in a subarctic coastal sea, Environmental Pollution 229, 531-538, doi:10.1016/j.envpol.2017.06.008

Soerensen, A.L., A. Schartup, S. Bouchet, D. Amouroux, A. Skrobonja, E. Björn (in prep), The effect of water column redox gradients on methylmercury cycling in a coastal sea – the Baltic Sea

Project Info

Project start: 2014