Over the past several years, dense clouds of phytoplankton (microscopic
plants that live in water) have appeared in the Bering Sea each summer.
One class of phytoplankton are particularly easy to spot from overhead.
Called coccolithophores, these phytoplankton grow calcium-rich shells. These shells are bright white and turn the water
where they grow a milky blue.
The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) captured this image of
coccolithophores off the coast of Alaska on September 13 and 14, 2000. (The Bering
Sea straddles the International Dateline, so the left side of the image is
the 14th while the right is the 13th.) The bloom covers approximately 400,000
square kilometers (154,000 square miles). Swirls of water with varying shades show
ocean currents and eddies. In general, the brighter the water, the higher the
concentration of coccolithophores. SeaWiFS has been taking pictures of this area
since 1997. Follow these links to see more images: