Overcoming adversity through diversity: aquatic carbon concentrating mechanisms

Carbon concentrating mechanism (CCM) systems, associated with evolutionarily diverse aquatic photosynthetic organisms, make a major contribution to global net primary productivity and marine carbon sequestration. Here, an overview of these global contributions is presented from their evolutionary origins, including a possible trigger for their diversification when the aqueous O-2/CO2 ratio rose above parity, and a re-definition of the paradox of phytoplankton. The reviews and research in the special issue also include molecular physiology and ecology of CCMs, through to future potential applications for sustaining carbon sequestration and supporting terrestrial crop productivity.