Blog Post By: Elaine Walters, Sea Turtle Intern
Bioluminescence is one of biology’s most magical phenomena. It can be found in a variety of organisms, with the vast majority being microscopic marine organisms called plankton. Plankton are tiny organisms that drift freely in the ocean currents. They can be plants, animals, or bacteria, and hold different properties as each; however, they all share a miniscule size and relatively low mobility. These organisms, specifically photosynthetic phytoplankton, provide much of the ocean’s primary productivity and fill a niche similar to grass.
Bioluminescence is often thought of as a tropical phenomenon; however, it can also be experienced here on Edisto Beach. If you were to go to the beach at low tide and turn your (red!) lights off you would be delighted to find tiny bluish sparks forming where the sand near the waterline is disturbed. The bioluminescence here is caused by dinoflagellates. Their numbers increase as the waters warm in the summer. This is very beneficial for the other larger organisms like fish, crustaceans, and even small aquatic larvae. Because of these many predators, it is probable that the dinoflagellates use their bioluminescence as a defense mechanism. This relies on the idea that there’s always a bigger fish. They make themselves highly visible so another bigger creature might come to consume their attacker.
There are a great many other bioluminescent organisms in the ocean, especially in the deep ocean where light is even more noteworthy than it is at the surface. It can even be observed on the backs of some loggerhead sea turtles which use Edisto Beach as a nesting beach. There is much about this glowing phenomenon that is still a mystery; however, it is a fantastic sight! Next time you find yourself on the beach at night shuffle your feet in the sand and find out for yourself!
Sea Turtle Biologist