Biofluorescence is the ability to reflect blue light that it hitting a surface, and then re-emit it as a different color – most commonly, green, red, and orange. You can see the exclusive National Geographic footage below. It should be noted that it’s different from bioluminescence, which is an animal’s property to produce light on its own due to a host bacteria and certain chemical reactions. Marine mammals are sometimes observed “glowing” underwater when they are surrounded by bioluminescent plankton.
The hawksbill turtle’s ability was discovered off the coast of the Solomon Islands near Papua New Guinea.
Gruber told National Geographic that the red on the turtles could indeed be caused by algae, that are potentially growing on their shell as a few kind of camouflage strategy.
Hawksbill sea turtles are critically endangered, with populations that have declined about 80 percent in the past decade, according to the worldwide Union for Conservation of Nature’s “red list” of endangered species.
“I’ve been [studying turtles] for a long time and I don’t think anyone’s ever seen this”, says Alexander Gaos, director of the Eastern Pacific Hawksbill Initiative, who was not involved in the find. “This is really quite awesome”. The marine biologist used a yellow filter on the camera to capture the lovely lights in intricate patterns across the turtle’s shell and head.
Usually, biofluorescence is employed by animals in an effort to attract prey, to communicate with each other or to defend themselves against predators. But he believes that the green glow was definitely from the turtle itself, which he describes in the video as a “UFO” that appeared out of nowhere. However, researchers will direct their attention to its closest relative, the green sea turtle, in search for similar abilities. It’s the ideal light environment that would fuel the biofluorescent quality in hawksbill sea turtles. “It’d be fairly hard to study this turtle because there are so few left and they’re so protected”, said Gruber.
Talking about the discovery, David Gruber explained that they now have a lot of work to do to work out exactly how the turtles use their biofluorescence.