Bioluminescence and optical variability in the ocean: An overview of the Marine Light‐Mixed Layers Program

Bioluminescence is the production of light from a chemiluminescent reaction in living organisms. Although compared to sunlight and moonlight, it is very dim [e.g., Smith et al., 1989], it features prominently in the ecology of the seas, occurring in all oceans, and is produced by a wide variety of marine plankton and nekton [Herring, 1987]. Its commonality across phyla and ecological niches means also that it has general adaptive significance. Even though it is broadly distributed, bioluminescence in the ocean remains largely unexplained because the intensity and the duration of the light produced are complicated functions of the interaction between the organism and its environment.