The video below shows bioluminescent algae washing on shore in Singapore recently. Notice the fluorescent blue light as each wave crests and crashes against the sand.
It’s beautiful, but it’s actually extremely toxic for humans if ingested. The glowing blue color is actually a defense mechanism for the algae.
Here’s a little bit more information about bioluminescent algae from Treehugger.com:
“Bioluminescent algae are a group of tiny marine organisms that can produce an ethereal glow in the dark. While the phenomenon may occur in any region or any sea depth, some of the most stunning instances happen on the surface when the algae come close to shore, sparkling with the movement of the waves or through the jostling of boats.
The algae’s glow is actually a natural defense mechanism; the light flashes occur when the algae’s environment is disturbed. Single cell algae called dinoflagellates are almost always behind this kind of surface luminescence The species is notorious for forming some of the most widespread bioluminescent algal blooms. These algal blooms — while extremely beautiful — are connected to harmful environmental effects and can be dangerously toxic.”
You can read more about bioluminescent algae from Treehugger.com here.