Diatoms: Made of Glass

 

On land we know that food chains begin with plants.  These plants are usually things that we can see very easily, like grasses and trees.  In the deep ocean there are no plants.  Instead food chains start with tiny algae, called phytoplankton.  One of the most important phytoplankton is diatoms.  You can think of diatoms as the grasses of the ocean.  They are very common.  They grow very fast.  And animals love to eat them.  In fact, so many animals love to eat them that diatoms have evolved an important way of protecting themselves.  They build a shell out of glass!

 

Diatom shells come in many shapes and sizes.  They are very thin.  But they are still so strong that engineers sometimes model their designs after diatom shells!  The shells protect diatoms from some predators.  The shells also make diatoms denser than water.  This means that when diatoms die they sink into the deep ocean.  For this reason, diatoms are important sources of food for deep sea organisms.  Sinking diatoms also remove carbon dioxide from the atmosphere.