Answer:
plankton
Step-by-step explanation:
Plankton are essential organisms for life on planet Earth, since they make up the base of the food chain, thus being a fundamental component for the balance of aquatic ecosystems and the maintenance of the food chain of such species. Thus, it is important to highlight that many animals feed on the most varied types of plankton, be they fish, whales, sharks, mammals, among others. Thus we can say that plankton is the group of organisms that form the basis of the energy pyramid in a pelagic marine ecosystem.
In addition, the importance of plankton in nature enables the survival of thousands of species, since the function of the capture of carbon dioxide from the atmosphere and the production of oxygen, responsible for phytoplankton, considered the main source of oxygen to the planet's atmosphere.