Total alkalinity (TA) was determined via Gran-titration (Smith and Kinsey 1978) with sample exchanger and titration unit (Titro-Line#alpha plus, SI Analytics, Mainz, Germany, with A 157 1 M-DIN-ID pH electrode), and sea water standards were calibrated regularly with a TA-standard (Dickson and Goyet 1991, standard from Oceanic Carbon Dioxide Quality Control, AG Dickson, Scripps Institution of Oceanography, http//andrew.ucsd.edu/co2qc/index.html). Carbonate chemistry parameters (Total carbon (TC) (lmol kg-1), pCO2 (latm), CO2 (lmol kg-1), HCO3- (lmol kg-1), CO3 2- (lmol kg-1), saturation statuses of Calcite (Xcal) and Aragonite (Xarag)) were calculated using 'co2sys.xls' (excel version modified after ORNL/CDIAC- 105, Lewis and Wallace 1998).