Sea sparkle Noctiluca scintillans
On warm summer nights, the waves along the coast or in the wake of ships sometimes glow with a spooky blue light. The creature responsible for this light is sea sparkle (Noctiluca scintillans), a type of microalga.
Balloon with a tentacle
Sea sparkle (Noctiluca scintillans) resembles a balloon with a tentacle. It is a single-celled dinoflagellate (an alga with a flagellum or tentacle) and is one of the microalgae. Unlike most algae, sea sparkle does not use sunlight to make food (photosynthesis). For this reason, scientists are not quite sure whether it is more like an animal or a plant. While it does have some plant-like characteristics, it also has to eat other organisms to survive. So it is neither a true microalgae nor a true animal.
Bioluminescence: a dazzling wonder
The light that Noctiluca scintillans emits is produced by a chemical reaction involving the protein luciferin and the enzyme luciferase. The cell emits the light only when physically disturbed, for example by wave action or the motion of passing fish. It produces an enchanting blue glow that can illuminate the whole coastline.
Red tide
Because Noctiluca is translucent, it is easy to observe what it has eaten. One of its food sources is red algae, whose red pigment is clearly visible inside the sea sparkle cell. During sunny weather or when nutrient concentrations are high, these red algae sometimes undergo a bloom. The abundance of this food sometimes leads to a sea sparkle bloom, colouring the water reddish-brown. This phenomenon is also known as a red tide and can sometimes be seen off the Dutch coast.
Want to experience sea sparkle for yourself?
You might get lucky and see sea sparkle in its natural setting from the beach, or you can come and see it at ARTIS-Micropia. The museum is home to many more fascinating microorganisms too. Why not drop by for a visit?