Tidal influence on dissolved CO₂ at Sapelo Island, Georgia, USA

Abstract Measuring carbon (C) loss through different pathways is essential for understanding the net ecosystem exchange of carbon dioxide (CO2) in tidal wetlands, especially in a reality where wetland mitigation and protecting coastlines from rapid sea-level rise is a growing priority. Tracking C loss can help reveal where an ecosystem is storing the most C, but it can also help scientists understand near- and long-term impacts of wetland restoration on climate. A recently developed partial pressure of dissolved CO2 platform was tested in a subtropical salt marsh with an apparatus that raised and lowered sensor housing with the tide. Additional low-cost water quality sensors were installed nearby for measuring turbidity and salinity. Here, we evaluated how well this floating sensor platform along with 28 d of biogeochemical data from a tidal salt marsh could detect C import and export from tidal effects. This work provides a pathway to low-cost, routine in-situ C exchange measurements which serve the needs of environmental managers, researchers, and others interested in better estimating wetland C storage and transport.