Diatoms

Natural history

The ecological significance of diatoms can't be overstated. Diatoms absorb carbon dioxide from the atmosphere, water, and energy from sunlight through photosynthesis. After a diatom converts these into carbohydrates for energy, the leftover oxygen molecules are released back into the atmosphere. Scientists estimate 20 to 40 percent of the oxygen we breathe is produced by diatoms. These tiny unicellular organisms affect climate on a global scale! 

Conservation

The open ocean is the world’s “plankton pasture,” home to the tiny drifting algae that power enormous food webs. Photosynthesizing phytoplankton like diatoms are important members of the ocean’s delicate balance. Plankton feeds small fishes, which in turn feed larger predators like fishes, seabirds, seals, and whales. We’re part of the food web, too, as communities around the globe depend on the fishes nourished by ocean plankton.

There's an enormous number of diatom species, and they can be very particular about their living conditions. For example, some species might only thrive at specific salinities, current strengths, water depths, or pH levels. Assessing diatom populations can help scientists monitor habitat stability in the face of a changing climate. The impact of climate change on diatom populations may cascade all the way up to the chemistry of Earth’s atmosphere.

Cool facts

• Diatoms live in glass houses. Their cell walls are made of silica, the same material in glass.
• The seasonal abundance of diatoms is one of the reasons there's such rich marine life in Monterey Bay.
• Diatomaceous earth is made up of the silica houses that were once home to diatoms. Some deposits are thought to be nearly 13 million years old.
• Diatomaceous earth is used in water filtration, insecticides, cat litter, and potting soils.
• Diatomaceous deposits make up 26 percent of Earth’s crust by weight.
• The largest diatoms are about the width of a hair.