What is phytoplankton

The term phytoplankton refers, within the world of biology, to the set of aquatic life organisms that are part of plankton , characterized by being able to feed in an autotrophic way by capturing solar energy during the photosynthetic process. Its name comes from the Greek “phyto” (plant) and “planktos” (vagabond), since they are photosynthetic organisms that live dispersed in the water, instead of fixed in one place.

However, the range of phytoplankton is always restricted to the highest layers of the sea, since they must access sunlight, an essential element for their survival. These microscopic plant organisms reproduce very easily and, in fact, are so abundant in the seas that they are responsible for carrying out half of the total photosynthesis carried out by all photosynthetic organisms on the planet.

Expand this information with this other article on What is plankton and its importance .

The main phytoplankton organisms of the different seas of the world are species that are included within the following groups of living beings, all of them photosynthetic:

• Diatoms: Actinella Brasilliensis Lewis , Amphipleura kutzing, Achnanthes bory, Anphora ovalis, Asterionella hassall.
• Dinoflagellates: Ceratium furca, Peridinium depresum, Noctiluca scintillans.
• Blue-green algae (cyanophytes): Rivularia bullata, Chroococcus turgidus, Anabaena spp., Oscillatoria spp .
• Green algae: Chaetomorpha aerea, Cladophora fascicularis, Phycodrys ovifolia, Petalonia fascia.
• Brown algae: Synura spp., Stephanophyxis palmeriana, Rhizosolenia calcaravis.

Within this classification of phytoplankton organisms , diatoms (carriers of a characteristic silica skeleton) stand out as the most numerous group, followed by dinoflagellates (with two structures for their movement called flagella). You can learn more about it in this other post about What is diatomaceous earth .

Although the vast majority of the organisms that make up phytoplankton are usually microscopic organisms, the presence of certain algae is common, such as sargassum (genus Sargassum), which fill the most superficial layers of the world’s seas and oceans with photosynthetic life, forming so from phytoplankton. To expand this information, we also recommend this other post about the Classification of algae .

Phytoplankton stands out for its important role in the proper functioning and balance of marine ecosystems . More specifically, phytoplankton is responsible for fulfilling the following biological functions :

• It is the primary producer within the trophic chain of aquatic ecosystems . Phytoplankton serves as food for living beings of equal or greater size (zooplankton), which are consumed by small fish (but also by whales) which, in turn, will be ingested by other larger fish or other predators, being the human being the final link in this trophic chain, by consuming the fish that are incorporated into the food market by the fishing industries.
• Phytoplankton is the main responsible for maintaining oxygen in the atmosphere , since oxygen is one of the final products of photosynthesis , of which we have commented before, phytoplankton generates a very high percentage throughout the planet.
• They contribute richness and marine biodiversity , adding the countless number of individuals that constitute it, to the already abundant marine vegetation.