Global SEM coccolithophore abundance compilation

Coccolithophores are globally important marine calcifying phytoplankton. They contribute to the organic carbon pump through the primary production and the ballast of organic matter, and to the carbonate pump through the production of calcium carbonate. Here we compiled all available scanning electron microscopy (SEM) coccolithophore abundance observations. Taxa were standardized following NannoTax3 to a species level where possible. Subspecies (e.a. C. leptoporus subsp. leptoporus and C. leptoporus subsp. quadriperforatus) were grouped as single species. The database contains 2556 abundance observations from 35 different publications. The data span the period of 1993-2017, with observations from all ocean basins and all seasons, and at depths ranging from the surface to 5000 m. We limited our compilation to SEM observations (or observations which further identified samples with SEM) because SEM provides greater detail of coccolithophore diversity than more commonly used polarized light microscopy. Although this limits the number of observations, this allows for a more in-depth analysis of coccolithophore ecology, such as the ecological significance of the coccolithophore life cycle.