Any night diver will most certainly tell you about all the fish and reef creatures that they have seen, many of which you may not see during a daytime dive. Animals, like octopus and some sharks, are most active at night. But for me, the real reason for jumping in after dark is to witness the spectacle of coral fluorescence.

Live coral is typically composed of a coral polyp host living in a symbiotic relationship with algae called zooxanthellae. Through photosynthesis, the algae provide nutrients to sustain the coral polyp. Within the polyp is a protein that when lit by special underwater lights excites the protein’s electrons. These proteins give off heat in their excited condition. Due to this heat loss, the light is reflected back at a different wavelength that to my camera has the appearance of glowing in the dark. It takes some special photographic equipment to capture this phenomenon, so the casual night diver is unable to witness what is unfolding before me.

Scientists believe that this fluorescence may serve as a kind of sunscreen to protect the algae and its coral host from becoming “sunburned” in the shallow ocean waters. That may in fact be true, but to me it is incredibly fascinating to see the various corals, tube anemones, and even algae-encrusted lizard fish fluoresce. On a night dive in Roatan, Honduras, I have seen very small amphipods crawling across the glowing coral. In Indonesia I have filmed a tube anemone’s fluorescing tentacles catching plankton with which it feeds itself. To my knowledge, Cousteau never employed this special equipment to capture coral fluorescence.

I have shot coral fluorescence in Bonaire, Roatan, and Indonesia, and the experience has been different in every location. I hope to shoot some off our South Carolina coast soon. In addition, I am working on a short film about the wild world of coral fluorescence. I hope you will have an opportunity to experience this beauty some time!