We are transiting the deep ocean gyres, where life survives on the edge. From the surface of these deep blue surface waters there seems to be little life, except for the occasional flying fish skating out of the path of the ship.
Flying fish in the North Atlantic Gyre. (Credits: Ian Brown, Plymouth Marine Laboratory, UK).
At depth in the twilight zone however, where only a fraction of the surface light penetrates, there dwells a multitude of diverse organisms that are sustained by bacteria. These organisms are photosynthetic and known as the Cyanobacteria and live at depths in excess of 100 meters on recycled nutrients that are the waste products from other organisms, and form the essential macro- and micro-nutrients for them to exist where few other organisms can survive.
Ancestrally, through oxygenic photosynthesis, the Cyanobacteria were thought to have converted the Earth’s un-inhabitable and hostile atmosphere into an oxygen rich one, which allowed a diverse range of life forms to colonise the planet. The chloroplasts of plants are thought to have evolved from Cyanobacterial via endosymbiosis.
Cyanobacteria can be found in almost every terrestrial and aquatic environment from the deep oceans, fresh water and terrestrial environments from the wettest ...