Vertical biogeography and realized niche traits of living coccolithophore community in the eastern Indian Ocean

Our investigations provided a broad view of annual-scale living coccolithophores in the quite under-sampled eastern Indian Ocean (EIO). The present study determined 7-year (2011-2018) living coccolithophore communities, as a major component in oligotrophic ecosystem, using polarized microscopic method. The ecologically important species Gephyrocapsa oceanica, Emiliania huxleyi, Algirosphaera robusta, Florisphaera profunda, Umbilicosphaera sibogae, and Umbellosphaera irregularis dominated the coccolithophore community out of 33 species. Annual mean coccolithophore abundance ranged 4306.1 - 11140.3 cells/L. Generally, coccolith detachment rates were enhanced with depth as seen from ratios of detached coccoliths and plated coccolithophores. We identified three types (upper-, middle-, lower-photic species) of vertical biogeography of coccolithophore taxa. To quantify the response of coccolithophores to environmental variables, we modeled univariate ecological realized niches of dominant spe...