Called red tide, this bioluminescent phenomenon was spotted on a California beach. This “stretch of water, which is part of the Pacific Ocean, was illuminated for a week before the glow diminished.” One caveat: during the day, it “can cause the water to turn a horrible reddish-brown color.” Continue reading for videos, more pictures, and additional information.


The glow – called ‘bioluminescence’ – occurs when a micro-organism in the water is disturbed by oxygen. Although a rare sight on a shoreline, the phenomenon is more commonly seen at sea in the wake of ships that stir up the oxygen in the sea, which causes the bioluminescent bacteria to glow.

Many undersea organisms ‘glow’, especially creatures that live at depths where light from the surface is less likely to penetrate. The night-time glow is a side-effect of blooming red algae, known as red tide, which can turn entire beaches scarlet and murky during the day.