HOT Hg investigates the biogeochemical, physicochemical, and microbial conditions that control Hg discharge and net MeHg production at hydrothermal vents (HV), and their impact on the local food web controlled by local hydrodynamics and dispersal. ANR HOT Hg will investigate Hg fluxes, speciation, and transformations at HV to provide better constraints on the global Hg cycle and to study the bioaccumulation on the ecosystem locally. To do so, 5 selected shallow and 3 deep hydrothermal vents sites, covering complementary geographic, geologic and biogeochemical settings will be surveyed for temperature, salinity, pH, O2, fluorescence, particles, CH4, optical properties of DOM, iron and sulfur speciation, macro nutrients, dissolved iron and other trace metals, REE and eNd measurements. LOV is participating to fieldwork and is responsible for DFe sampling and measurements.
