Contrasting Carbon Dioxide Inputs and Exchange in Three Adjacent New England Estuaries

Four surveys of the adjacent Cocheco, Bellamy, and Oyster estuaries reveal spatial heterogeneity with respect both to river-born carbon dioxide (CO₂) fluxes and CO₂ exchange with the atmosphere (−17 to 51 mmol m⁻² day⁻¹), a finding partially explained by CO₂ inputs from contributing watersheds. Nonuniform nutrient and organic carbon loading from upstream rivers and within the estuaries is considered as a mechanism resulting in the variability between estuaries. Conditions during the surveys included spring river runoff and phytoplankton blooms, drought with baseline river flow, and a historic flood which led to a large CO₂ release to the atmosphere. This study highlights the variability of CO₂ transport and release found between proximate estuaries over a wide range of flow conditions.