Asked in EconomicsZoology or Animal Biology
What is the economic importance of protozoans?
November 05, 2007 4:20AM
Since some types of protozoans (namely plankton) are "considered by some to be the most important organisms on Earth"*, the economic importance, while maybe difficult to measure, would seem to be quite large.
*see following text for a discussion:
Protozoans are unicellular microbes whose cells have membrane-bound nuclei.
In the 21st century, the tendency has been to classify algae outside the class of protozoans. This then would preclude kelp (a type of brown algae) from the class of protozoans. Another possible, widely-used, microorganism that might be confused with protozoa are diatoms--diatomaceous earth, for example, is a valued product (and therefore of great economic importance) made from diatoms.
Unicellular aquatic Protista (plankton) form a very important component of the food chain. The photosynthetic ones are called phytoplankton and the heterotrophic ones are called zooplankton (which also includes many animal larvae or tiny crustaceans). The planktons are credited with supporting the lower end of the ocean food chains. They are therefore considered by some to be the most important organisms on Earth.
(General info on protozoa:
Most protozoa are too small to be seen with the naked eye-most are around 10-50 μm, but forms up to 0.5 mm exist-but can easily be found under a microscope. Protozoa are ubiquitous throughout aqueous environments and the soil, and play an important role in their ecology. Protozoa occupy a range of trophic levels. As predators upon unicellular or filamentous algae, bacteria, and microfungi, protozoa play a role both as herbivores and as consumers in the decomposer link of the food chain. Protozoa also play a vital role in controlling bacteria population and biomass. As components of the micro- and meiofauna, protozoa are an important food source for microinvertebrates. Thus, the ecological role of protozoa in the transfer of bacterial and algal production to successive trophic levels is important. Protozoa such as the malaria parasites, trypanosomes and leishmania are also important as parasites and symbionts of multicellular animals.)