What are Diatoms? - Diatoms of North America

Why should I care?

Diatoms turn energy from the sun into sugar

Diatoms have light-absorbing molecules (chlorophylls a and c) that collect energy from the sun and turn it into chemical energy through photosynthesis.

Diatoms produce 20-30% of the air we breathe

Through carbon fixation, diatoms remove carbon dioxide (CO2) from the atmosphere. The CO2 is converted to organic carbon in the form of sugar, and oxygen (O2) is released. We breathe the oxygen that diatoms release.

Diatoms feed the oceans, lakes and rivers

Diatoms produce long-chain fatty acids. Diatoms are an important source of these energy rich molecules that are food for the entire food web, from zooplankton to aquatic insects to fish to whales.

Diatoms are the most diverse protists on earth

Diatoms are eukaryotes, one of the Heterokont algae. Estimates of the number of diatom species range from 20,000 - 2 million. Scientists are discovering new species every year.

Chattachoochee River Gwinnett Forsyth Counties Ga

Diatoms tell us about the health of aquatic systems

Diatoms are particular about the quality of water in which they live. For example, species have distinct ranges of pH and salinity where they will grow. Diatoms also have ranges and tolerances for other environmental variables, including nutrient concentration, suspended sediment, flow regime, elevation, and for different types of human disturbance. As a result, diatoms are vital for assessment and monitoring biotic condition of waters.

Taking a microscopic view of diatoms

How big are diatoms?

Nearly all diatoms are microscopic - cells range in size from 2 µm to 500 µm (= 0.5 mm). The biggest diatoms are about the width of a human hair. Scientists use light microscopes (LM) or scanning electron microscopes (SEM) to view diatom. When diatoms are viewed with a light...

Where do diatoms live?

Diatoms live in water, or even in moist habitats or soils. Some diatoms live as free-floating cells in the plankton of ponds, lakes and oceans. Planktonic species often have special adaptations to prevent sinking, including the formation of long chains of cells, linked by silica...

Does climate affect diatoms?

Yes, climate affects diatoms in complex ways. As the planet warms due to the increase in carbon dioxide, scientists predict that larger marine plankton, like diatoms, will decrease compared to smaller plankton, like cyanobacteria. In lakes and rivers, a changing climate alters...

How long does a diatom cell live?

A single diatom cell can divide asexually and form two new cells. Cells may divide as quickly as once a day up to once every several weeks. The silica cell wall is a sort of biological constraint, because with each cell division diatom cells become progressively smaller. As a...

How do diatoms get big again?

Diatoms regain their maximum size through the formation of a special structure, termed an auxospore. An auxospore is a unique type of cell that possesses silica bands called perizonia, rather than a rigid silica cell wall. The perizonium allows the cell to expand to be its...

Do diatoms form fossils?

The silica cell walls of diatoms do not decompose, so diatoms can be preserved over long periods of time, up to tens of millions of years. Diatoms are not true fossils, because the cell walls are not fossilized, or replaced by another mineral. The silica cell walls accumulate in...

What is diatomaceous earth?

Diatomaceous earth, or diatomite, is composed by the silica cell walls of diatoms. There are many deposits of diatomite in North America, both marine and freshwater. Diatomites are commercially mined for many uses. Diatomite is a crucial component of dynamite. Alfred Nobel, who...

Where can I buy diatoms?

Living diatom cells can be isolated from their surrounding assemblage of cells and in kept alive in cultures. Culture collections have staff that do the time-consuming work to maintain strains of diatoms over the long term. These collections provide a valuable source of...

Diatoms are single-celled algae