Biogeochemical cycling in the critical coastal zone: Developing novel methods to make reliable measurements of geochemical fluxes in permeable sedimen

Despite the importance of this part of the ocean, the environmental controls on the consumption, production and conversion of nutrients and other solutes in coastal, often sandy (permeable), sediments remain poorly understood. This uncertainty arises from a paucity of direct measurements in the upper centimetre-decimetre of coastal sediments, which often feature very steep geochemical gradients. Direct measurements have not been possible previously due to a lack of in-situ sensors for many biogeochemical species. However, new Lab-on-Chip sensors provide analytical capabilities to finally resolve geochemical processes and provide a much-needed step change in coastal sediment understanding. This project will develop and test novel methods using for the first time Lab-on-Chip sensors to quantify nutrient gradients and fluxes in permeable sediments and will transform our understanding of critical biogeochemical processes across coastal zones.