Rethinking Land-Ocean Connectivity - An Integrated Approach to Understanding the Effects of Groundwater on Coastal Ecosystems – medLOC

The objective will be addressed in an integrated approach of hydrogeological, (bio)geochemical and ecological investigations, and in collaboration with expert colleagues from regionally and internationally leading institutions. The project aims at the quantification of groundwater and associated nutrient fluxes, and of groundwater effects on lagoon primary production, as well as the innovation of the use of molluscs as bio-archives for groundwater exposure to coastal ecosystems.

The results of this project will provide an improved understanding of key ecohydrological processes in the coastal zone, and improve our capacity to sustainably manage hydrological and ecological resources in the coastal zone in the future.

none to date.

Conference activities
1) Invited keynote: Stieglitz T, 2016. Groundwater-ocean interaction and its effects on coastal ecological processes – are there groundwater-dependant ecosystems in the coastal zone?, 24th Salt Water Intrusion Meeting and 4th Asia-Pacific Coastal Aquifer Management Meeting, Cairns, Australia. 4-8 July 2016.
2) Invited keynote: Stieglitz T, Cook P, Clark JF, van Beek P, Hancock G, 2015. Multi-scale studies of advective transport across the sediment-water interface with radioactive tracer tools – some examples from coastal environments. Annual Goldschmidt Conference Prague, Czech Republic, Aug 2015.
3) Invited keynote: Rodellas, V, Submarine Groundwater Discharge: a relevant but overlooked process in the Mediterranean Sea. XXII meeting of the Italian Association of Oceanography and Limnology (AIOL). Verbania, Italy, 2015.
4) Invited speaker: Rodellas, V, Garcia-Orellana, J., Masqué, P., Feldman, M., Weinstein, Y. Evaluating Submarine Groundwater Discharge as a source of nutrients to the Mediterranean Sea using 228Ra. Goldschmidt conference 2015, Prague, Czech Republic, 2015.
5) Conference Organising Committee. International Conference Radium & Radon Isotopes as Environmental Tracers Ra-Rn5, Girona, July 2016. Conference committee: J Garcia Orellana (E), V Rodellas (E/F), P Mas (E), T Stieglitz (F), P van Beek (F).

Publications
1) Rodellas V, Garcia-Orellana J , Trezzi G, Masqué P, Stieglitz TC, Bokuniewicz H, Cochran KJ, Berdalet E. Using the radium quartet to distinguish sources of submarine groundwater discharge: terrestrial groundwater vs seawater recirculation through sediments. Geochimica et Cosmochimica Acta 196 (2017) 58–73
2) Stieglitz is invited guest editor of a special issue of Estuarine Coastal and Shelf Science to be published in 2018.

The coastal zone hosts some of the most dynamic, diverse and productive ecosystems on Earth. These ecosystems experience significant pressure from human activities, and respond drastically to direct and indirect human disturbance and to climatic-hydrologic variability. It is universally accepted that hydrological land-ocean connectivity is an important driver of coastal ecosystems. The paradigm that “water flows from the land to the sea via rivers” seems to be too self-evident to question: whilst the critical role of surface water discharge from rivers to coastal ecosystems is well documented for decades, the ecological ‘footprint’ of hidden subsurface flow of groundwater on hydrology, productivity, diversity and functioning of coastal ecosystems along the world’s shorelines is far less well understood, and remains virtually un-studied along most of the world’s shores, including much of the Mediterranean Sea’s coastlines.
As transitional (brackish) water bodies, coastal lagoons are of critical ecological and economic importance. At the same time, these semi-enclosed systems are disproportionally affected by land-derived fluxes of water and solutes through restricted offshore exchange. The long-term objective of this study is to improve the understanding of the direct and indirect impacts of human activities affecting coastal groundwater resources on the ecological functioning of coastal lagoonal ecosystems in the Mediterranean region. Whilst a vast body of work has been and continues to be carried out on many aspects of ecosystem functioning, climate and human impacts on these lagoon systems, the ‘downstream’ ecological effects of groundwater and associated solute fluxes to these systems remains unknown despite recent evidence that they may indeed play a considerable role.
I therefore propose to establish an integrated, interdisciplinary, multi-national and multi-institutional research program documenting the role groundwater flows play in Mediterranean lagoon ecosystems, ranging from near pristine to heavily impacted ecosystems, with the aim of closing the significant gap of fundamental understanding of the role groundwater flows play in the functioning and vulnerability of coastal ecosystems. The objective will be addressed in an integrated approach of hydrogeological, (bio)geochemical and ecological investigations, and in collaboration with expert colleagues from regionally and internationally leading institutions. The project aims at the quantification of groundwater and associated nutrient fluxes, and of groundwater effects on lagoon primary production, as well as the innovation of the use of molluscs as bio-archives for groundwater exposure to coastal ecosystems. The results of this project will provide an improved understanding of key ecohydrological processes in the coastal zone, and improve our capacity to sustainably manage hydrological and ecological resources in the coastal zone in the future.