Sea sparkle is a phenomenon that occurs in the ocean as the result of a little creature called Noctiluca scintillans. These luminescent algae are organisms that float in swarms of millions under the surface of the ocean and that cause the sea to glow. This unicellular creature measuring up to one millimeter is heterotrophic, which means it eats other organisms.
Because of their size, these algae can be caught from the surface of the sea with a plankton net and studied with a strong magnifying glass. The Noctiluca scintillans is one of the wonders of the sea. When disturbed, the creatures give off a burst of phosphorescent blue light. It's a fascinating experience for night swimmers, whose movements become illuminated, and it is particularly fascinating to watch fish as they dart in different direction leaving behind a glowing trail as they pass through the algae.