The famous Red Sea is a seawater inlet of the Indian Ocean that lies between Africa and Asia. If you’ve ever been there though (or if you just look at pictures), you’ll notice that the sea is not actually red. So, one could easily wonder: why do they call it Red Sea if it’s not red?
Well, even though no one knowns for sure the exact origin of the name, it is believed that the Red Sea got its name because it is occasionally filled with a type of cyanobacteria algae called Trichodesmium Erythraeum. When these blooms of bacteria die, they turn the blue-green water of the sea to a reddish-brown.
The color of course, is not intense and it varies across the expansive body of water but it’s enough to give the sea the nickname… red sea.