Bioluminescence
At night, water can have an appearance of sparkling light due to the bioluminescence of dinoflagellates. More than 18 genera of dinoflagellates are bioluminescent, and the majority of them (including Gonyaulax) emit a blue-green wavelength. Therefore, when mechanically stimulated—by boat, swimming or waves, for example—a blue sparkling light can be seen emanating from the sea surface. The luciferin-luciferase reaction responsible for the bioluminescence is pH sensitive. When the pH drops, luciferase changes its shape, allowing luciferin, more specifically tetrapyrrole, to bind. Dinoflagellates can use bioluminescence as a defense mechanism. They can startle their predators by their flashing light or they can ward off potential predators by an indirect effect such as the "burglar alarm". The dinoflagellate can use its bioluminescence to attract attention to itself, thereby bringing attention to the predator and making the predator more vulnerable to predators from higher trophic levels.
Bioluminescent dinoflagellate ecosystem bays are among the rarest and most fragile.
Read more about this topic: Dinoflagellate