NITROLINKS - NITROGEN - Loading into the Ria Formosa through Coastal Groundwater Discharge CGD) – Pathways, turnover and LINKS between land andsea in the Coastal Zone

NITROLINKS focuses on the least understood coastal ecotone: coastal sediments including groundwater discharge. Using the Ria Formosa as a study site, we seek to answer the questions: 1) How important are permeable sediments on the borderline between inland groundwater inputs and productive marine ecosystems as sources or sinks of nitrogen? 2) How important is the discharge of groundwater containing nitrate into the coastal lagoon and what is its biogeochemical relevance, and Endingly, 3) Do coastal managers need to account for potential source when implementing water and land-use policies in the littoral zone? Research includes mapping of groundwater discharge zones, evaluation of fluxes and seasonal discharge patterns, quantification of biogeochemical process rates at seepage sites, and tracing the transfer of groundwater-borne N to the autotrophic food-web. Results will clarify how CGD relates to the N cycle in the Ria Formosa, filling a current gap in the knowledge of the functioning of coastal lagoon ecosystems.