Coccolith mass: for each sample, mass measurements were done with SYRACO (Beaufort and Dollfus, 2004; doi:10.1016/j.marmicro.2003.09.003) on at least 100 - 300 coccoliths and then averagedCoccolith length: for each sample, length measurements were done with SYRACO (Beaufort and Dollfus, 2004; doi:10.1016/j.marmicro.2003.09.003) on at least 100 - 300 coccoliths and then averaged Coccolith, corrected length: averaged coccolith lengths obtained from SYRACO where converted into Lc using the formula: Lc = (0.585 x coccolith length from SYRACO) + 0.4537Calcification index: Ci=Ms/Mn); Mn=coccolith volume x density of calcite; coccolith volume=(Ks constant for E. huxleyi coccolith medium-calcified (Young and Ziveri, 2000; doi:10.1016/S0967-0645(00)00003-5) x averaged coccolith length obtained from SYRACO)