Our natural world is made up of incredibly diverse lifeforms that range in all different sizes, from the humongous blue whale and the giant sequoia to the tiny ant and minuscule plankton. So, it should be no surprise that some of Earth’s smallest creatures — such as diatoms — can actually have some of the biggest impacts on our planet.
Diatoms are microscopic single-cell algae. These organisms come in a variety of shapes, such as cylindrical orbs or long, boat-like structures. What makes a diatom interesting is that they have cell walls made of glass, or silica. Known as a frustule, these glass walls are covered in patterned pores and ridges.
Diatoms are found abundantly in almost every aquatic environment: oceans, lakes and wetlands, too. As a plant-like lifeform, they rely on photosynthesis for survival. They can live individually or in colonies, and when the environment is just right — plenty of nutrients and sunlight — their populations will rapidly expand. Living diatoms make up a good portion of Earth’s biomass and create 20% of our planet’s oxygen.
But dead diatoms are particularly important to understanding the health of our planet, too. Because the frustule is heavier than the water surrounding it, after a diatom dies, the glass skeletal remains slowly sink to the bottom of the ocean or lake and become part of the sediment. Here, the shells can reside for millions of years.
This means that scientists can study these tiny, fossilized diatoms to better comprehend the global changes in our climate and aquatic environments — both then and now.
Visit Invisible World of Water at the Academy and witness the microscopic wonders of snow crystals, water drops and diatoms — hidden just out of sight.