Phytoplankton is a microscopic algae set that have structures similar to plants. That's exactly why they get their name: the term phyto, in Greek, means plant.
It is a type of plankton - microscopic microorganisms that exist in the aquatic ecosystem. In addition to phytoplankton, zooplankton, protozooplankton and bacterioplankton are also part of this group.
They live on the surface of water, mainly in the seas, although they can also be found in other aquatic environments, such as lakes and rivers.
The two most easily found types are the dinoflagellates (Pyrrophyte) and diatoms (Chrysophyta).
Phytoplankton characteristics
They are plant microorganisms that can have varied forms (rounded, prickly or oval, for example). They can live alone or grouped in colonies.
The most easily found phytoplankton are single-celled algae. But there are others, such as the flagellates. This species is characterized by the presence of a flagellum, which serves to boost its locomotion in the waters.
Phytoplankton growth
The growth of the phytoplankton population in a location is influenced by several environmental factors, such as:
- amount of nutrients in the ecosystem,
- water temperature,
- presence of fungi and bacteria or other aquatic plants,
- amount of light that falls on the waters.
bloom
When the phytoplankton population over-develops a phenomenon called bloom or flowering, that is, when there is an excessive presence of these microorganisms. This occurrence is easily noticed when, for example, the surface of a lake is covered by a green layer.
O bloom it can happen naturally, but it can also happen because of human influence, as in polluted water. The phenomenon may be responsible for cause imbalances in the local ecosystem, as it interferes with the food chain and affects the existence of other animals.
In many cases, flowering ends when excess nutrients are depleted or when the ambient temperature returns to its normal state.
How important are phytoplankton?
Phytoplankton are responsible for the production of almost half of all oxygen present in the atmosphere from the earth. As they have chlorophyll and live on the surface of the water, they receive direct sunlight in quantity enough to do photosynthesis, a process that helps in air purification through the release of oxygen.
Learn more about the photosynthesis.
They are also very important in preserving life and water balance, as are part of the base of most food chains of these ecosystems, that is, phytoplankton serve as food for other animals.
Furthermore, its presence on the water surface makes up a barrier capable of filtering the amount of light that penetrates into the water.
Phytoplankton and bioluminescence
A specific type of these organisms - the bioluminescent phytoplanktons - when grouped in large quantities it creates a luminescence phenomenon, leaving the water in shades neon.
The phenomenon is explained by a chemical reaction of these organisms, which generate a bluish or greenish luminosity that can be seen more easily at night.
Bioluminescence record in Mosquito Bay/Puerto Rico.
Science does not yet know how to explain for sure the reason for the luminescence, but it is believed that it is a defense mechanism to ward off predators. Another explanation relates the occurrence to the species' reproductive cycle.
In Brazil, there are records of these phenomena in some beaches in the south and southeast of the country.
Also read the meaning of Plankton.