Global mapping of planktonic "chameleons"
Cyanobacteria of the genus Synechococcus are ubiquitous in the world ocean and contribute significantly to both the marine food chain and the carbon cycle. Like chameleons of the plankton world, some of them are able to change pigmentation to match the ambient light color. Yet, their distribution or abundance has remained unknown so far. Research scientists from CNRS and CEA, together with international collaborators including Professor Dave Scanlan from the University of Warwick, have just demonstrated these color-shifters are the most abundant group of Synechococcus in the ocean —representing about 40% of the whole population at depth and high latitudes. This adaptive capacity is an important asset for such planktonic organisms that are carried around by currents in areas where the color of the water varies as it allows them to keep photosynthesizing efficiently and to supply energy to the rest of the food web. This discovery represents a major breakthrough in our understanding of these organisms, which prove to be excellent bio-indicators of climate change.
Their findings are published in PNAS (February 12, 2018)