Plankton is the main food source in the ocean. Phyto plankton feeds plankton. Phyto plankton is the is one of the main sources of food in the ocean. Without plankton there would be no life in the ocean. Plankton is a microscopic algae/plant matter
50-80% of the oxygen in the ocean comes from plankton.
Plankton is the fuel for our carbon based society