EARTH Bay of Biscay -- 29 Apr 2005 --Enormous clouds of rich blue-green phytplankton swirl through the waters of the Bay of Biscay in this true-color satellite image.

EARTH Bay of Biscay -- 29 Apr 2005 --Enormous clouds of rich blue-green phytplankton swirl through the waters of the Bay of Biscay in this true-color satellite image. Stretching across almost the entirety of the Bay, the phytoplankton reveal currents and eddies in the water. Phytoplankton are tiny single-celled organisms that feed off of sunlight and nutrients in the water- they use chlorophyll, like their land-based plant relatives, to drive this process. It is the chlorophyll that gives them their distinctive colors, and which in large-enough populations helps them stand out against the deep blue of clear water -- Picture by Lightroom Photos / NASA / Topfoto