Cover: In Rosati et al. (https://doi.org/10.1002/2017GB005700), Rosati et al. found elevated concentrations of Hg and MeHg in the euxinic waters of the Black Sea.

By integrating observations from the GEOTRACES cruise and 1D biogoechemical modeling along the extended redox gradient of the Black Sea, the work highlights that the bulk of MeHg is produced in situ in anoxic sulfidic waters, and inputs from external sources (i.e. rivers, sediment and the Mediterranean Sea) are negligible.

The investigation also stresses the significant role of Mn oxides that act as scavengers of Hg species in the suboxic water and mediate their cycling between suboxic and anoxic waters. In its present state, calculated HgT inputs to the Black Sea still exceed the outputs.

See pp. 529–550.