Diatoms are photosynthesizing algae found in nearly every aquatic environment on the Earth. They possess a skeleton made of silica and are only capable of limited movement. To access sunlight, diatoms are confined to the photic zone, water depths down to roughly 200 meters. Diatoms are microscopic with a diameter of approximately 200 microns. However, when grouped in large numbers, diatoms can form visible sediments.
Diatoms form the base of aquatic food chains in freshwater and marine habitats and are primary food sources for the smallest planktonic animals. Diatoms are crucial for maintaining the natural progression of Earth’s ecosystems. They are believed to produce 40 percent of the Earth’s oxygen through photosynthesis, and they are regarded as the primary source of new energy in the ocean ecosystem.
The number of diatom species present on Earth is up for debate, with estimates ranging from 20,000 to 2 million. This variance exists because scientists are still working to understand the basics of the algae species, which has proven quite complicated. Diatom cell structure may be simple, branched or enveloped in a gelatinous tube. Individually, diatoms do not have a visible color. However, when grouped in a large mass, the organisms often appear dark brown or black.