A comparison of Globigerinoides ruber calcification between upwelling and non-upwelling regions in the Arabian Sea

Abstract

Shell weights of planktonic foraminifera species Globigerinoides ruber in the size range of 300–355 $\upmu$ m were measured from sediment traps in the western and eastern Arabian Sea which represent upwelling and non-upwelling conditions respectively. In the Western Arabian Sea Trap (WAST), G. ruber flux ranged from 33.3 to 437.3 #/m2/day and shell weights ranged from 6.7 to 14.2 $\upmu$ g. Whereas, in the Eastern Arabian Sea Trap (EAST), flux ranged from 0.7 to 164.6 #/m2/day and shell weights ranged from 10.4 to 14.8 $\upmu$ g. Shell weights of G. ruber versus flux showed significant correlation at both the sites which reveals that shell calcification mainly depends on optimal growth conditions. Though the WAST and EAST location have distinct difference in pCO2 and sea surface temperature (SST), the shell weights of G. ruber are similar in these two regions which suggest that surface water pCO2 and SST do not show dominant influence on shell calcification on a seasonal timescale.