Metal composition and fluxes of sinking particles and post-depositional transformation in a ria coastal system (NW Iberian Peninsula)

► Seasonal dependence of trap metal composition driven by biological, physical and chemical processes. ► Terrestrial material during winter changing to marine-like towards spring and summer. ► Terrestrial inputs control Al/Ti/U/V; organic matter Cu/Pb/Zn/Cd; others depend upon both factors. ► Vertical fluxes of Cu/Pb/Zn increase with organic matter while continental inputs does for Al/Ti/U/V. ► Degradation of sedimentary organic matter releases metals (except Cd and Co) to the dissolved phase.