Glow with the Flow: Bioluminescence on Bald Heads Beaches
Glow with the Flow: Bioluminescence on Bald Heads Beaches
Have you ever been on the beach at night and noticed the sand begin to glow as you walk through it, seen flashes of blue as the waves crash against the shore, or even noticed the whitewash of a wave seeming a little brighter than normal? That is a phenomenon known as bioluminescence. This glow comes from a chemical reaction that occurs in many different species. From the flash of a lightning bug to the lure of an angler fish, bioluminescence can be seen in many different environments throughout our incredible planet. The glow of these critters has many different uses depending on the species, from communication, to attracting food, to scaring away predators.
One of these glowing critters is known as “sea sparkle” which are microorganisms called dinoflagellates. A type of phytoplankton, which are free floating microscopic organisms that use the sun’s light in order to make their food, just like plants on land. Certain species of dinoflagellates have enzymes that emit light when agitated. This light is thought to be a way to deter predators that may try to eat these tiny creatures, acting as a “burglar alarm” that distracts the dinoflagellates predator and can even attract an even bigger animal to eat the original attacker. This defense mechanism is a great example of chemical reactions found in nature that aid in the survival of an organism.
Bioluminescence
These tiny glowing creatures can float freely in the ocean, create colonies, or settle on surfaces such as sand, rocks, and even the shells of some larger marine animals. One of the animals on Bald Head that we see these bioluminescent phytoplankton on is our nesting sea turtles. If you are lucky enough to see the amazing sight of a nesting female laying her eggs, you may notice a faint blue glow coming from her shell as she crawls up the beach and lays her nest. This is bioluminescence caused from the tiny dinoflagellates that have settled on her shell. As the turtle moves, the phytoplankton are agitated, causing a chemical reaction that makes it seem as if the turtle itself is glowing.
While the shell of a turtle is not the only place, or even the main place, these glowing creatures can be found, seeing them brings a different type of magic to the already incredible experience of seeing a sea turtle on the beach. The presence of these phytoplankton on turtles is important to science because it can show us where these elusive creatures spend their time in the water. But my favorite part about seeing these glowing turtles is seeing how such a large animal plays such an important role, as a home, for such small critters. Phytoplankton are the base of the oceans food chains, as the most abundant primary producer found in marine environments, making them a very important organism in the ocean. Since they are primary producers, these critters require an abundance of nutrients and sunlight in order to photosynthesize. When dinoflagellates settle on a turtle’s shell, they are provided with sunlight when the turtle surfaces to breathe. Additionally, since sea turtles are capable of swimming much further distances than an individual dinoflagellate could cover just by floating along the oceans currents, these dinoflagellates are exposed to a wider range of habitats and oceanic conditions. This allows for them to encounter more vital nutrients, reducing how limited their ability to produce energy is, as nutrient deficiency is often what inhibits phytoplankton from photosynthesizing. These phytoplankton play such an important role in the oceans ecosystems as primary producers, and their symbiotic relationship with sea turtles is truly fascinating. Even though we can’t see these individual tiny creatures with just our two eyes, we most definitely can see their glow.
Caroline Kornegay, Sea Turtle Protection Program Intern
