Prélèvements d'eau des mésocosmes pour analyses, lors de l'expérience menée en Corse en juin/juillet 2012 (© A. Ree, PML)

Gelatinous plankton Pelagia and Ctenophores  (Photo : Fabien Lombard)

Dinoflagellate Ceratium ranipes grd mains (Photo : Sophie Marro)

Préparation des mésocosmes sur le ponton du laboratoire d'Océanographie de Villefranche lors de l'expérience menée en rade de Villefranche en février 2013 (© L. Maugendre, LOV)

Ocean color satellites travel around the Earth at an altitude of about 700 to 800 km.

Vue sous-marine d'un groupe de mésocosmes montrant la structure de flottaison en surface (© Stareso)

Villefranche-sur-Mer in stormy weather, winter 2011 -  Photo : J.-M. Grisoni

Diatom species Odontella mobiliensis (Photo : Sophie Marro)

Dinoflagellate Ceratium azoricum (Photo : Sophie Marro)

Gelatinous plankton salpes and Beroe (Photo : Fabien Lombard)

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)

Rosette used to collect seawater samples during a scientific cruise in the South Pacific Ocean. During the austral summer, the amount of chlorophyll a is so low that the water becomes deep blue, almost purple. (Photo : Joséphine Ras)

Dinoflagellates Ceratium platycorne var platycorne (Photo : Sophie Marro)

Dinoflagellate Ceratium gravidum (Photo : Sophie Marro)

Phytoplankton bloom observed in the Barents Sea (North of Norway) in August 2010 by the ocean color sensor MODIS onboard NASA satellite Aqua. Changes in ocean color result from modifications in the phytoplankton composition and concentration. The green colors are likely associated with the presence of diatoms. The shades of light blue result from the occurrence of coccolithophores, phytoplankton organisms that strongly reflect light due to their chalky shells - Source : NASA's Earth Observatory (http:/earthobservatory.nasa.gov)

Acantharia (Photo : Fabien Lombard)