Particle flux data from 27 sites in the Atlantic Ocean have been compiled with a view to determining regional variations in the strength and efficiency of the biological pump and quantifying basin-wide fluxes and estimating the potential oceanic sequestration of atmospheric CO2. An algorithm is derived relating annual particulate organic carbon (POC) flux to primary production and depth that yields variations in the Export Ratio (ER = POC FLUX/Primary Production) at 125 m of between 0.1 and 0.4 over the range of production from 50 to 400 gCm-2 yr-2. Significant regional differences in changes of the ER with depth are related to the temporal stability of flux. Sites with more pulsed export have higher shallow ERs and show more rapid degradation of particulate organic carbon (POC) flux with depth, resulting in little variation in fluxes below ca. 3000 m. The opposing effects of organic carbon production and calcification on pCO2 of surface seawater are combined to calculate an "effective carbon flux" at the depth ofeuphotic zone and at the base of the winter mixed layer. POC flux at the base of the euphotic zone between 65°N and 65°S amounts to 3.14 Gt C yr-1, of which 5.7% is remineralised above the winter mixed layer, and is thus not available to sequestration on climatically relevant time scales. The effective carbon flux, termed Jeff, amounts to 2.47 Gt C yr-1 and is a measure of the potential sequestration of atmospheric CO2 for the area considered. A shift in the composition of sedimenting particles (opal: carbonate ratio) is seen across the entire North Atlantic, indicating a basin-wide phenomenon that may be related to large-scale changes in climatic forcing.