Use of Coccolith based Proxies for Palaeoceanographic Reconstructions

Coccolithophores are one of the major groups of marine carbonate producers and are the most important pelagic unicellular calcifying organisms which play a pivotal role in the marine biogeochemical cycles. Since past few decades, coccolithophores have gained attention due to their unique role in the global carbon cycle and particularly due to their combined effects on the biological carbon and carbonate counter pumps. Owing to their high diversity, better preservation, fast turnover rate and significant role in the marine biogeochemical cycles, coccolithophores are identified as a potential proxy to reconstruct palaeoceanographic changes. In this review, a broad introduction of the biology and biogeography of extant coccolithophores is discussed with a brief overview on the preservation of the coccoliths and their applications. This includes how coccolith abundance, diversity and morphometric studies are used to reconstruct palaeotemperature, palaeosalinity, palaeoproductivity and palaeocirculation. In addition, implications of coccolithophores in the isotopic studies for the estimation of palaeotemperature and palaeoproductivity are also discussed.