Among marine life, bioluminescence — the production and emission of light by living organisms — occurs widely.
The combination of bioluminescence and the fluid motion of dolphins swimming can be hypnotic, as this clip shows.
For you armchair marine biologists, the principal chemical reaction in bioluminescence involves the light-emitting pigment luciferin and the enzyme luciferase, assisted by other proteins, such as aequorin in some species. The enzyme catalyzes the oxidation of luciferin.
We also found this link showcasing “15 Places To See Bioluminescence.”