Pteropods from the Caribbean Sea: variations in calcification as an indicator of past ocean carbonate saturation

[摘要] The aragonite shell-bearing thecosome pteropods are animportant component of the oceanic plankton. However, with increasingpCO₂ and the associated reduction in oceanic pH (ocean acidification),thecosome pteropods are thought to be particularly vulnerable to shelldissolution. The distribution and preservation of pteropods over the last250 000 years have been investigated in marine sediment cores from theCaribbean Sea close to the island of Montserrat. Using the Limacina DissolutionIndex (LDX), fluctuations in pteropod calcification through the most recentglacial/interglacial cycles are documented. By comparison to the oxygenisotope record (global ice volume), we show that pteropod calcification isclosely linked to global changes in pCO₂ and pH and is, therefore, aglobal signal. These data are in agreement with the findings of experimentsupon living pteropods, which show that variations in pH can greatly affectaragonitic shells. The results of this study provide information which maybe useful in the prediction of future changes to the pteropod assemblagecaused by ocean acidification.

[学科分类] 地球化学与岩石