Jon Edwards on Nostr: Nearly all of the world's chalk is produced by tiny, marine phytoplankton called ...

Nearly all of the world's chalk is produced by tiny, marine phytoplankton called coccolithophores.

While the innate purpose of the chalk they create is unknown, scientists speculate that the structures they build serve as a form of armour, protecting them from predators, viruses, & harmful UV rays.

On a global scale, the chalk they produce has helped regulate the acidity of the oceans for millions of years.