BaselineMercury deposition during the previous century in an upwelling region; Cabo Frio, Brazil

•The Hg flux was related to the relatively high silt-clay and organic carbon burial.•Atmospheric deposition is the main input of Hg to continental shelves.•Upwelling may be contributing to the Hg fluxes on the Cabo Frio continental shelf.

To investigate the upwelling influence on Hg biogeochemical cycles and the sedimentological changes during the previous ∼150 years, four sediment box-cores were sampled along an inshore offshore transect on the Southeastern Brazilian continental shelf. Mercury values were found to be relatively low, with means ranging between 8.08 and 30.4 ng g−1. Mercury fluxes along the sediment cores are directly related to the well documented historical regional activity and global atmospheric deposition. The narrow relationship between mercury and organic carbon suggest that upwelling phenomenon and primary production may play an important role on Hg input and distribution along continental shelf depositional settings.