Answer:  Real - Bioluminescent Dinoflagellate Plankton

In 1753, the first modern dinoflagellates were described by Henry Baker as "Animalcules which cause the Sparkling Light in Sea Water".  Sometimes referred to as "Fire Algae" it is recognized usually in darkness as it has the appearance of blue glowing glitter swirling in the water when disturbed. Truly a wonder of nature. This particular Dinoflagellate looks earily like an alien spacecraft. Photo by Joe Scott