Have you ever seen this? That is the question in the description of a Facebook video by Beautiful South Africa.

The video? A beautiful blue display of bioluminescent plankton captured by Andrea Ben at Umdloti, also known as eMdloti, along the KZN North Coast.

Known as the northern lights of the ocean, bioluminescence occurs when a living organism produces and emits light from its body owing to an internal chemical reaction that turns chemical energy into light energy.

When a family experienced this blue wonder in Umdloti in 2023, uShaka Sea World education executive manager Jone Porter told The North Coast Courier that bioluminescence could be a quick flash or a steady glow. It’s used by all sorts of creatures at different depths to give predators the slip, attract something tasty to eat, or even to reel in a potential partner.

She pointed out: “Several deep-sea corals have bioluminescence in their tentacles. They use it to attract plankton, which they then gobble up.”

Porter mentioned that some of those twilight zone critters, like seal sharks, goblin sharks and diamond squids, use bioluminescence to tempt their prey without scaring them off, before nabbing them.