Arctic fjords are known to modulate iron fluxes from glacial meltwaters to the ocean regulating marine primary productivity and thus atmospheric carbon dioxide removal. This ice-to-ocean iron transport is driven by the sedimentary recycling of particulate to dissolved iron up to the seafloor which is promoted by bioturbation (=biological reworking of sediments through the activities of benthic macrofauna). In my current project, I investigate the links between macrobenthic communities, their functional traits and respective bioturbation activity, external environmental conditions and seafloor iron cycling in Greenlandic fjord systems through a combination of field studies, experimental microcosm incubations and a modelling approach.