This proposal aims at facilitating an efficient and lasting re-integration of Dr Maria Tzortziou in the Hellenic Center for Marine Research (HCMR). The main goal is to initiate a competitive and interdisciplinary research program at HCMR that will advance our understanding of the role that wetlands and tidal marshes play in dissolved organic matter (DOM) dynamics, carbon cycling, photochemistry, biogeochemistry, and water quality changes in coastal margin ecosystems. Specific objectives of the research initiated with EcoDOM include: (i) Characterize landscape-scale variation in the quantity and quality of the dissolved organic compounds exported from different wetlands and coastal tidal marshes in SE Europe, and understand implications of such variation for estuarine biogeochemistry, ecosystem productivity, and water optics. (ii) Develop novel and improved modelling approaches for describing and predicting effects of photochemical processes on DOM quality and degradation. Accurate quantitative description of these effects is prerequisite for improving the accuracy of more general biogeochemical/ecological models of carbon cycling. (iii) Apply a novel radiative transfer model to examine the effects of wetland DOM inputs on underwater light fields. (iv) Link the proposed work to remote sensing applications by developing bio-optical relationships between remotely sensed quantities, DOM optical properties and biogeochemical variables in coastal waters. EcoDOM research is highly relevant to the European Union policy making and research initiatives for increased understanding and modelling of climate-related biogeochemical cycles in European wetland ecosystems and sustainable management of EU’s coastal natural resources. The HCMR Institute of Inland Waters is committed to absorb the research initiated in the proposed project by offering job stability through long-term research scientist appointments to Dr Tzortziou with the conclusion of the project.