This was a once-in-a-lifetime moment. Could this be visual proof that dolphins have learned how to hunt by using the glow of bioluminescence in tandem with echolocation? Let’s go a little deeper: The bioluminescence is light emitted by dinoflagellates (a plankton not visible to the naked eye). These little guys give off light whenever they are disturbed. It’s often thought by scientists that they give off light as a defense mechanism to attract larger predators to go after the thing bothering th