Salpes - La vie enchaînée Bien que d’apparence primitive, les salpes sont de proches ancêtres des poissons. Lorsque les algues abondent, les salpes prolifèrent en de longues chaînes d’individus clonés.
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)
Diatoms - Life in glass houses Champions of photosynthesis, these unicellular organisms appeared at the time of dinosaurs.They produce a quarter of the oxygen we breathe.
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)
