Distribution
Emiliania huxleyi has an exceptionally wide distribution. These scanning electron microscope images show E. huxleyi from the tropical Atlantic (left) and Antarctic (right) oceans.
Vertical distribution
Like all coccolithophore species, Emiliania huxleyi is confined to the upper part of the water column where light allows photosynthesis. The depth of this zone varies with oceanic conditions, but typically E. huxleyi only occurs in the top 50-100m of the water column.
Geographical distribution
E. huxleyi has an exceptionally wide distribution.
Most coccolithophore species have reasonably clear ecological preferences in terms of:
- temperature
- trophic levels
- water depth
As a result, there are clearly different assemblages of coccolithophores in, for instance, the surface waters of oligotrophic gyres, the deep photic zone and in eutrophic upwelled waters (e.g. Winter et al. 1994).
E. huxleyi, however, occurs almost everywhere:
- from near-freezing sub-Arctic waters to the equator
- from extreme nutrient depleted waters to upwelling zones
- from the surface to below the deep chlorophyll maximum
A one litre water sample taken from the photic zone of the ocean virtually anywhere in the world is likely to contain numerous specimens of E. huxleyi, with abundance varying from several hundred cells in low-productivity, mid-ocean waters to a few million cells per litre in blooms.
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Population biology
Emiliania huxleyi is the most abundant coccolithophore species and frequently dominates assemblages. Explore why it might be so successful compared to other species.