When ocean waves glow electric blue at night, the light comes from millions of living creatures. Dinoflagellates - microscopic plankton - carry a chemical called luciferin that flashes the instant water is disturbed. It is a defense: the burst of light summons predators of whatever is eating them. Mosquito Bay on Vieques, Puerto Rico holds the Guinness World Record for the brightest bioluminescent bay, with 700,000 glowing organisms per gallon.
