Present and past coccolith assemblages in the South Atlantic: implications for species ecology, carbonate contribution and palaeoceanographic applicability.

Coccolithophores, unicellular marine phytoplankton, belong to the most important primmy producers in the oceans. These haptophyte algae possess a calcitic exo-skeleton (coccosphere), composed of minute scales, the coccoliths. The coccoliths constitute a major part of the fine-grained, pelagic sediments. As carbonate producers and photoautotrophic organisms, the coccolithophores playa significant double-role affecting the carbon-cycle via the carbonate and biological pumps. While during photosynthesis the climate-relevant green-house gas CO2 is removed, it is released during carbonate production.