Researchers studied groundwater flow and nutrient fluxes in Dauphin Island to understand how freshwater and contaminants move to the ocean. They used radon and radium isotopes to track groundwater discharge, finding that storm events increased discharge rates up to three times. Most of the groundwater was fresh, driven by marine and terrestrial forces, with nutrient dynamics varying across the island. The eastern shore had high nitrogen fluxes, while the south-central shore had more nitrate. This study shows the importance of understanding groundwater dynamics in barrier islands, especially those near urban areas or large estuaries.