This biogeochemical survey took place in October 2017 on board the Marine Institute's R.V. Celtic Voyager off the west and south-west coast of Ireland. This survey formed a key part of the ongoing research into biogeochemical processes along the Irish west coast that is being conducted as part of the iCRAG Marine Geoscience spoke. The survey comprised of CTD (Conductivity, Temperature, Depth) profiles, reineck box cores. underway radium sampling and plankton net tows. The main objective of the expedition is two fold: (i) To examine the influence the of the outflow plume of the Shannon river on the optical properties and nutrient concentrations along the west coast of Ireland from Valentia island to Galway Bay. (ii) To determine the extent of submarine groundwater discharge in this region by the use of the radium quartet.