Diatoms are a major group of microorganisms found in the oceans, waterways and soils of the world. Living diatoms number in the trillions: they generate about 20 percent of the oxygen produced on the planet each year; take in over 6.7 billion metric tons of silicon each year from the oceans in which they live; and contribute nearly half of the organic material found in those oceans. The shells of dead diatoms can reach as much as a half mile deep on the ocean floor; and the entire Amazon basin is fertilized annually by 27 million tons of diatom shell dust transported by westerly transatlantic winds from the bed of a large dried up lake once covering much of the African Sahara. Diatoms are unicellular; they can live alone or form colonies, taking shapes such as ribbons, fans, zigzags, and stars.
Diatoms
