Samples from core ODP site 977, retrieved in the Alboran Sea (Western Mediterranean Sea), have
been studied in order to better constrain the factors controlling the Sr/Ca ratio in planktonic foraminifers.
For this purpose, this ratio has been measured in two different species, Neogloboquadrina pachyderma
(right coiling) and Globigerina bulloides, in samples from the marine isotope stage 7 (250-190 kyr). The
fast and pronounced fluctuations in shell Sr/Ca observed between substages cannot only respond to water
salinity, pH nor temperature changes. However, the results obtained suggest that shell Sr/Ca variations in
planktonic foraminifers from the Alboran Sea are also related to Sr/Ca glacial/interglacial changes in the
ocean. This would mean that the paleotemperature reconstructions based on corals, might be revised
since coral Sr paleothermometry would have underestimated sea surface temperature during glacial
episodes