The relationship between wind speed and air-sea gas exchange in nearshore environments could differ significantly from that in the open ocean due to wind fetch limitation, younger wave ages, and higher surfactant concentrations. Indeed, dual tracer (³He/SF₆) experiments that we have conducted in diverse nearshore environments, including Florida Bay, the coastal Baltic Sea, an Icelandic fjord, and a coastal salt pond in Rhode Island, consistently show that nearshore gas transfer velocities fall below open ocean predictions. Yet current oceanographic models almost universally apply open ocean wind speed parameterizations, which substantially overestimate gas transfer in coastal and nearshore environments by up to 65%. This overestimation has important implications for marine carbon dioxide removal (mCDR), since these deployments will occur nearshore, close to the energy, infrastructure, and human resources needed to operate them. Because mCDR pathways such as ocean alkalinity enhancement (OAE) and direct ocean removal (DOR) rely on the transfer of CO₂ across the air-sea interface, accurate knowledge of gas exchange is fundamental to monitoring, reporting, and verification (MRV). Currently, observations of nearshore gas exchange remain sparse, leaving insufficient data to establish a robust, universal nearshore parameterization, which is a key bottleneck to accurate MRV and scalable mCDR deployment. Future air-sea gas exchange experiments should prioritize nearshore sites representative of planned mCDR deployment regions, across a range of wind fetch and wave conditions. 

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