When Columbus neared the coast of the New World, he thought he saw lights of civilization twinkling on the shores. What he really saw, though, was likely bioluminescence from thriving marine life. The creation of light by living creatures, known to scientists as bioluminescence, is an evolved trait that benefits the organism by offering camouflage, mimicry, sexual attraction and more. This lush, lazy light is what we see in fields full of fireflies at night, or on the jellyfish as they bob in the night sea.
The shark you see above, however, is not bioluminescent. The gentleman below can explain.
Enter David Gruber, Associate Professor Biology and Environmental Science at Baruch College. He recently made some exciting discoveries involving another interaction of light and life: biofluorescence. Instead of producing light, biofluorescent creatures absorb light in their environment and reemit it as fluorescent. And, it turns out, this phenomenon happens more than we ever realized, deep in the ocean concentrated in a band of brilliance around 500 – 600 meters.
The trick is to get high powered lights, scientific cameras and actual scientists down to that depth to observe and record data about the phenomenon. The solution?
An atmospheric diving suit called the Exosuit working in conjunction with an ROV. The suit is the latest generation of the life support system that Sylvia used in 1979 in Oahu when she set the world’s deepest solo dive without a tether to the surface. (She descended to 1,250 feet while strapped to the front of a submarine. She then unstrapped herself and walked around the bottom, where the pressure was 600 pounds per square inch.)
Check out the two pictures below to see how the times have changed.
That surreal shark you see at the top of this article? The non-photoshopped image is real: the stunning world of biofluoresence revealed by Dr. Gruber and his team. First, Dr. Gruber’s shines a very bright blue light on the creature. (Blue, after all, is the color of the world they live in.) Then when filming, Dr. Gruber uses a yellow filter that allows us to see just the fluorescent light that comes off the creature: the reds and greens of a surreal world beyond our normal perception.
Mission Blue Board Member, Patty Elkus and her husband Rick are dedicated supporters of Seahorse research at the Birch Aquarium/SIO and enjoyed assisting David with this phase of his research.
It turns out biofluorescence is not an isolated trait in either bony or cartilaginous fish. In a single paper, Dr. Gruber’s team identified 180 species that exhibit the quality. Many questions remain such as: can they see their own biofluorescence? And, if the trait is so widespread, it likely has a physiological function — what is that function?
Check out this beautiful video to get a sense of it. How cool is that?