A bloom of the coccolithophorid, E. huxleyi, occurred on the eastern Bering Sea shelf during September--October 2000. We examined the impact of this bloom on the CO2 system in the surface water. Drawdowns of total alkalinity (TAlk) from the values predicted by the TAlk-salinity conservative mixing relationship reached a maximum of 82.0 ¿mol kg-1, but was confined to latitudes 57.0¿N--61.0¿N. Surface water partial pressures of CO2 (pCO2) in excess of 400 ¿atm, depletion of nitrate + nitrite and low concentrations of silicate were also found, together with the TAlk drawdowns. The relationship between salinity-normalized TAlk and total CO2 suggests that the ratio of calcification to photosynthesis during the bloom was approximately 1.0, implying that any CO2 produced from calcification was balanced by photosynthesis. We discuss the possible cause of the observed high surface water pCO2 in the TAlk-drawdown (bloom) area.