Coccolithophore Calcification: Changing Paradigms in Changing Oceans

Coccolithophores represent a major component of the marine phytoplankton and contribute to the bulk of biogenic calcite formation on Earth. These unicellular protists produce minute calcite scales (coccoliths) within the cell, which are secreted to the cell surface. Individual coccoliths and their arrangements on the cell surface display a wide range of morphological variations. This review explores some of the recent evidence that point to similarities and differences in the mechanisms of calcification, focussing on the transport mechanisms that bring substrates to, remove product from the site of calcification, together with new findings on factors that regulate coccolith morphology. We argue that better knowledge of these mechanisms and their variations may inform more generally how different species of coccolithophore are likely to respond to changes in ocean chemistry.