'Emiliania huxleyi is a spherical coccolithaporoid less than 4/1000ths of a millimeter in diameter (4 microns). As the most abundant phytoplankton in the world’s seas, Emiliana is a major producer of three climate forcing substances: organic carbon, calcium carbonate and dimethyl sulphide (DMS). These coccolithopores close pack together in a swarming mass before they fall to the water’s floor, or rise to its surface. The role of this most prevalent phytoplankton in the world’s oceans is to reflect the sunlight, much like snow in the arctic. Miles-long blooms of Emiliania, sometimes as large as the country of England, swirl with the ocean gyres to form massive, brilliant white “creatures” on the ocean’s surface.' 
LANDSAT satellite image of a bloom in the English Channel off the coast of Cornwall, 24 July 1999. The bloom was sampled six days later by scientists at Plymouth Marine Laboratory and positively identified as Ehux. Image courtesy of Andrew Wilson and Steve Groom:
Black and white pictures:
http://scaleindependentthought.typepad.com/scale_independent_thought/2009/08/visioning-sustainability.html
Emiliania Huxleyi homepage:
http://www.soes.soton.ac.uk/staff/tt/
