Marine cyanobacteria do not survive solely on photosynthesis

Marine cyanobacteria are single-cell organisms that settled in the oceans millions of years ago. They are organisms that, by means of photosynthesis, create organic material by using inorganic substances. Specifically, the cyanobacteria known as Prochlorococcus and Synechococcus are the most abundant photosynthetic organisms on Earth and they generate a large part of the oxygen necessary for life, hence the oceans are the Earth's real lungs.