Bioluminescent algae are a type of algae (simple plantlike organisms) that naturally glow in the dark. Dinoflagellates are one example of marine algae that fluoresce.
Most species of bioluminescent algae glow blue, although in some cases, the glow is a green or orange color. The glow is due to a chemical called luciferin that the algae naturally produce. Luciferin reacts with an enzyme called luciferase, which is closely related to the chlorophyll found in plants, and the result is a bluish-green glow. Bioluminescent algae are usually naturally found in warm-water lagoons or bays but are often grown in artificial conditions for experimentation or as a light source.