Average chlorophyll concentration in the surface ocean (from mi-September 1997 to August 2007) from the ocean color sensor SeaWiFS (NASA). Subtropical gyres, in the center of the oceanic basins, are characterized by very low concentrations of chlorophyll a (dark blue) - Source : NASA's Earth Observatory (http:/earthobservatory.nasa.gov)
Plankton Plankton are a multitude of living organisms adrift in the currents.Our food, our fuel, and the air we breathe originate in plankton.
Dinoflagellate Ceratium extensum(Photo : Sophie Marro)
Rosette used to collect seawater samples during a scientific cruise in the South Pacific Ocean. Duringthe austral summer,the amount of chlorophyllais so low thatthe water becomesdeepblue,almostpurple. (Photo : Joséphine Ras)
Scientists collecting seawater samples from the rosette (Photo : Stacy Knapp, Woods Hole Oceanographic Institution)
