Emiliania Huxleyi - Abundance and Distribution

Abundance and Distribution

E. huxleyi is by far the most abundant coccolithophore found in the Earth's oceans, and is considered ubiquitous, occurring everywhere except the polar regions. During massive blooms (which can cover >100,000 square kilometers), EHUX cell concentrations can outnumber those of all other species in the region combined, accounting for 75% or more of the total number of photosynthetic plankton in the area. EHUX blooms regionally act as an important source of calcium carbonate and dimethyl sulfide, the massive production of which can have a significant impact not only on the properties of the surface mixed layer, but also on global climate (Balch et al., 1991). The blooms can can be identified through satellite imagery because of the large amount of light back-scattered from the water column, which provides a method to assess their biogeochemical importance on both basin and global scales. These blooms are prevalent in the Norwegian fjords, causing satellites to pick up "white waters", which describes the reflectance of the blooms picked up by satellites. This is due to the mass of coccoliths reflecting the incoming sunlight back out of the water, allowing the extent of EHUX blooms to be distinguished in fine detail.

Extensive E. huxleyi blooms can have a visible impact on sea albedo. While multiple scattering can increase light path per unit depth, increasing absorption and solar heating of the water column, EHUX has inspired proposals for geomimesis, (Seitz 2011) because micron sized air bubbles are specular reflectors, and so in contrast to E. huxleyi, tend to lower the temperature of the upper water column, . As with self shading within water-whitening coccolithophore plankton blooms, this may reduce photosynthetic productivity by altering the geometry of the euphotic zone, and both experiments and modeling are needed to quantify the potential biological impact of such effects, and the corollary potential of reflective blooms of other organisms to increase or reduce evaporation and methane evolution by altering fresh water temperatures.