Concentrations of various mercury species (total mercury, THg; monomethyl mercury, MeHg; dissolved gaseous mercury, DGM; and dimethylmercury, DMeHg) as measured during GA10 GEOTRACES cruise in the South Atlantic Ocean.

The data on mercury speciation is needed for oceanographic campaigns because such data are generally missing from remote regions. The authors were selected to perform onboard measurements and to collect samples for later laboratory determination during the GA10 cruise across 40S parallel in the South Atlantic Ocean. The dataset contains results on mercury speciation; that is, concentrations for total, monomethyl-, dimethyl- and dissolved gaseous mercury. Total mercury and dissolved gaseous mercury were measured onboard the ship and the waters were collected from regular rosettes. Samples for mono- and dimethylmercury were stored for later analysis in the laboratory and were collected from trace metal clean (titanium) rosettes. Due to the nature of contamination, it is possible to use two different rosettes and not only a clean one.