EXCLUSIVE: How "Glowing" Sharks See Each Other
April 25, 2016 - What do
biofluorescent sharks see through
their eyes? The recent discovery of more than 200 biofluorescent marine creatures has sparked interest in the biological and ecological roles of this phenomenon. Marine biologist and National Geographic Emerging Explorer
David Gruber delves into the study of how these creatures see by designing a "
shark-eye camera" that replicates the vision of biofluorescent sharks. Gruber enters the deep waters of Scripps Canyon, off the coast of Southern California, to image glowing swell sharks without the aid of artificial light. The resulting footage shows that swell sharks see each other's biofluorescent markings much better than other objects in the dark, blue sea.
Read "Through a Shark's Eyes: See How They Glow in the Deep."
Transcript
This amazing thing happened a few years ago. We accidentally found a fluorescent fish and then that led us to over 200 fluorescent fish including two species of sharks.
I wanted to film these sharks in their natural world with the “shark-eye camera” and see essentially what their world looks like through their eye.
So humans see in three colors: red, green and blue. And as soon I was go underwater we start losing all the other colors quickly and it becomes dark and blue.
These biofluorescent sharks that we’re looking at are called swell sharks. These sharks had one visual pigment and it was only right at the intersection of blue and green. They’re in a blue world where everything is blue but they’re capable of turning blue into green.
Once we learned what the pigment of the shark eye was like we filtered a very sensitive camera we had, a RED Epic, to have the same color sensitivity as the shark.
At 120 feet in this canyon, we were just using this blue ocean light. And this was difficult for us humans but the sharks can still see amazingly well. And that makes sense because they’ve been down there for 400 million years and they’ve been living in an environment with very little light.
This was a huge step for us because we didn’t even know could the swell sharks, could the fluorescent sharks see this. And with this study, now we know yes they can see the fluorescence among themselves.
This almost seems like when it was discovered that bats were communicating with sound outside of human detection and that there was a whole mode of communication going on. And with sharks, it could be something similar. How they’re using it, now we can go further and further.
We’re in this era where we’re losing species at a rate that we haven’t seen in millions of years. So in trying to connect with nature, it’s important to kind of empathize with nature and to even see what these animals are seeing. And by putting ourselves behind the shark’s eye gives us a portal in to their life.