The Iridescent Sea
When the moon is right on an Outer Banks night and ghostly, blue, opalescent waves nip at the shore, you can sometimes behold a magic show of nature for all to see. Life on Planet Earth is in one of its most curious states!
On these special occasions, ocean life can produce light through a chemical process in their bodies called bioluminescence, or the ability of an organism to create light. It is one of nature’s most amazing phenomena. Bioluminescence happens when certain chemicals mix and produce energy that generates light. Thus its ephemeral glow is emitted and plays with our imaginations.
While relatively rare on land, bioluminescence is very common in the ocean. Eighty (80) percent of the animals that live between 200 and 1,000 meters (656 and 3,280 feet) depth are bioluminescent. Bioluminescence is most common among fish, squid, and what is called the gelatinous zooplankton – jellyfish, siphonophores, comb jellies, and other animals which are mostly made of water.
Bioluminescence happens when certain chemicals mix and produce energy that generates light. Thus its ephemeral glow is emitted and plays with
our imaginations.
While usually blue, because this is the light that travels best through the water, bioluminescence can range from nearly violet to green-yellow (and very occasionally red). All bioluminescent organisms use a reaction between an enzyme and a substrate to make light. Still, different species use different chemicals in the process, suggesting to scientists that the ability to make light may have evolved independently many times.
Plankton are drifting organisms that live in the ocean and provide a vital food source for marine life. They are also one of the creatures in which bioluminescence is very high. Therefore, if you see a glowing blue light on your Outer Banks vacation, you’re either witnessing bioluminescent plankton, or you’re about to meet a new extraterrestrial friend. It’s common for scuba divers to run into these little creatures (bioluminescent plankton, not ETs,). Their presence in your trail sometimes can even be seen on the beach, making your footsteps sparkle in the moonlight.
The United States National Park Service officials say the blue color is likely caused by microscopic “dinoflagellate” plankton floating in the water. According to the NPS, these plankton make their food using photosynthesis, and bioluminescence is a byproduct. This plankton is typically found in tropical waters, but it can be swept farther north if the conditions are right. The Outer Banks has had only one documented case of this “red tide,” which occurred in 1987. “Red Tide” more frequently happens on the Pacific Coast and along Florida’s Gulf Coast.
“Red tide” is the common name for what many experts refer to as “harmful algae blooms.” Harmful algae blooms (HAB) are the sudden proliferation of one or more marine species of microscopic organisms called phytoplankton, primarily dinoflagellates. Some of these species produce neurotoxins. These organisms can collectively cause adverse and sometimes fatal effects in fish, birds, marine mammals, and even humans in large enough numbers.
There are approximately 80 species of aquatic plants that can cause harmful algae blooms. Additionally, blooms can occur in both marine as well as freshwater environments. Some HAB species can turn the water a reddish color in high concentrations, which is the source of the name “red tide.” Other species can turn the water green, brown, or purple. In contrast, others, although highly toxic, do not discolor the water at all.
Most phytoplankton are harmless. They are essential elements in the foundation of the global food chain. Without them and their ancestors, higher life forms, including humans, would not exist and could not survive.
While cognitive of the negative side of certain plankton, to a lighter note, “a common name for these organisms is ‘sea sparkle.’ When these organisms are moved by waves or the paddle of a kayak or canoe, the light becomes visible,” the National Park Service reports. “The best times for viewing bioluminescence are in the summer and fall on dark, cloudy nights before the moon has risen or after it sets.” Seeking such phenomena in the Outer Banks is the stuff of legends in oceanic aficionados here. The biggest question about the mysterious bioluminescence that makes the surf glow a neon blue is, where will it appear next?
It’s not an easy question to answer, with strong ocean currents, whipping winds, and swinging tides pushing around the elusive bloom of bioluminescent phytoplankton that put on a light show when they are disturbed. But something to put on your bucket list is watching as the white crest of the waves explode with an electric blue as they crash on the shore, lighting up dark stretches of beach.
Darker beaches, under a new moon, without much light usually have the best glow, but use caution and judgment about where to seek out the glowing waves. Be patient. The bioluminescence comes in waves – yes, pun intended. It can be bright one minute and dark the next. Seasoned veteran “glitter wave chaser” photographers recommend staying at a spot for a bit and avoiding looking at your phone to adjust to the dark. This will help you spot glowing waves. Many also say part of finding this so much fun is the actual chase to find the bioluminescence phenomena. Not knowing where or when you’ll find it, but actually going out and searching as much as possible, you, your friends, and your cameras looking for glittering stars in the sea! And don’t forget to look up at the Milky Way while you’re at it.
Author: Rebecca Orr
Rebecca is a recent Iowa transplant to the Outer Banks and spends her days enjoying the beach and seafood, and her nights contemplating the sea and the stars. It has been her long-held dream to be a writer.
