This brilliant cyan pattern scattered across the surface of the Black Sea is a bloom of microscopic phytoplankton. The multitude of single-celled algae in this image are most likely coccolithophores, one of Earth’s champions of carbon pumping. Coccolithophores constantly remove carbon dioxide from the atmosphere and slowly send it down to the seafloor, an action that helps to stabilize the Earth’s climate.
This image of this swirling blue bloom was captured on July 15, 2012, by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite. Note that the image is rotated so that north is to the right. Ocean scientist Norman Kuring of NASA’s Goddard Space Flight Center suggested the bloom was likely Emiliania huxleyi, though it is impossible to know the species for sure without direct sampling of the water.