How a cyanobacterium manages iron scarcity makes it the most successful photosynthetic organism on Earth

The sea is the world's largest ecosystem, and it harbors two photosynthetic organisms that produce approximately half of the oxygen on Earth. The cyanobacterium Prochlorococcus is the most abundant photosynthetic organism in the oceans and fixes approximately 4 gigatons of carbon each year, comparable to the net global primary production of the world's agriculture industry.