The flux of carbon dioxide has been measured by eddy correlation techniques over shallow coastal waters at an outer submerged reef near Miami, Florida, during two weeks in March when the sea water was gradually warming. Large upward fluxes were detected, much larger than expected, and they were nearly linearly proportional to friction velocity u* for the wind speeds of 3--10 m s-1 encountered. In 10 m s-1 winds, the flux was 0.30--0.35 mg m-2 s-1 and the aqueous transfer velocity across the interfacial sublayer was about 0.20 cm s-1. The measured eddy fluxes of submicron particles were also directed upward and displayed a strong, nearly linear dependence on u* similar to the case for CO2. Bubbles could be a source of increased CO2 transport and of particle production by film drops associated with bursting at the surface, but the number of bubbles required seems to be too large when comparisons are made with current knowledge of bubbles produced by breaking waves.