A large phytoplankton bloom off of the coast of Portugal can be seen in this
true-color image taken on April 23, 2002, by the Moderate-resolution Imaging
Spectroradiometer (MODIS) aboard NASA’s Terra satellite. The bloom is roughly
half the size of Portugal and forms a bluish-green cloud in the water. The red
spots in northwest Spain denote what are likely small agricultural fires.
Acquired February 9, 2010, this true-color image shows jewel-toned water caused by a phytoplankton bloom off the coast of Argentina. Roughly mimicking the coastline, the bloom forms a giant semicircle in the Atlantic Ocean.