From cyanobacteria to krill: the hidden chain that sustains marine life and ours

Everything begins with cyanobacteria, the primordial cells that gave rise to the plant organisms we know today and that "invented" photosynthesis. They also "taught" these algae to absorb carbon dioxide while producing oxygen.

Just like land plants that appeared later, but with different forms that in most cases are not even visible to the human eye, phytoplankton has a total biomass 200 times smaller than that of plant organisms growing between soil and air, while producing about 50 percent of the breathable oxygen.

The best known is krill, or Euphausiacea, which according to scientific classification constitutes an order that includes several species. They resemble small shrimp, with an exoskeleton divided into three segments: head, thorax, and abdomen. Each year between 150,000 and 200,000 tons of krill are harvested, mainly off the southern coasts of Japan.

In addition to being one of the main food sources for large marine animals and aquatic birds, krill also sustains turtles and fish living in domestic aquariums (or, in the case of fish, in aquaculture tanks). It is used in the pharmaceutical industry as a source of phospholipids and omega-3s, mainly in the form of oil, for recreational fishing, and is also incorporated into the menus of Japanese and eastern Russian cuisine.