The Guaymas Basin hydrothermal vents in the Gulf of California have been visited during RV Atlantis mission AT37-06 in December 2016. Aim of this mission was to understand element fluxes and microbially driven reactions at the diffusive vent sites. The submarine ALVIN and push cores were used to sample undisturbed sediments at specific locations covering different temperature and geochemical regimes. From these cores porewater was sampled using Rhizons. Here we present concentrations of select anions in the porewater. We measured the concentrations of sulfate, sulfide, chloride, ammonia, phosphate and silicate.