Never heard of bioluminescence before? No worries, we will explain in pictures and words.
Picture yourself strolling along a beach at night. A gorgeous moon lights up the sky. Suddenly, you see something flickering in the waves. You think someone is in the water with a flashlight, that there is a lighthouse in the distance or that you saw an airplane. However, the beach and the water are deserted.
Photo Credit: Kristofer Williams
You look again, and that same eerie blue luminescent glow is there, right in front of you. You may be worried that the aliens have landed, but it is in fact bioluminescent algae performing an awesome show.
Bioluminescent algae defend themselves by producing a blue-green light whenever they feel threatened, for instance when their habit is disturbed. This process is called bioluminescence.
Bioluminescence how does it work?
Something as simple as a slightly larger wave can set them off. The light, which is controlled by circadian rhythms, is only visible at night, when the world is in darkness.
It is believed that these algae have been the inspiration for many a sailor’s ghost story. Indeed, if you are lucky enough to have ever seen them, you will feel as if you have some otherworldly experience. They algae can even leave a footprint of glow on the sand itself!
There is actually nothing mystical about nature’s glow in the dark beauty. In fact, it is all about practicality. The flash of light only lasts about a tenth of a second and it is the algae’s only real survival system. By emitting the light, they frighten any potential predator away.
Larger predators, who are well aware of what this is, are attracted by it and start to hunt for those elements that set the lights off in the first place.
There is a scientific explanation for this as well, of course. It has to do with luciferin, a complex molecule, which holds and releases extra energy. It does this by emitting cold light, meaning you would not be able to see the glow using a heat detector. In order to achieve all of this, the enzyme luciferase comes into play.
Interestingly, luciferase doesn’t actually cause the reaction itself. All it does is make sure that the reaction is quick and efficient.
In daytime, the pH levels of water are a steady 8. This keeps the luciferin molecule stable. However, when it becomes night, the pH levels drop to 6, which changes the shape of the molecule. When this happens, luciferase can bind to the molecule, which makes the reaction happen much quicker.
Bioluminescence why does it happen?
Scientists believe that the fact that light was created was actually purely accidental. It is believed that the main purpose of luciferin is to bind any excesses of oxygen.
Too much oxygen can damage the algae’s cells, which they need to protect themselves from. Obviously, therefore, luciferin has always been related to self-preservation and protection, which is why the algae still exist today.
Whatever the scientific explanation is, what matters most is that this is perhaps one of nature’s most beautiful displays and certainly one of the most fascinating and interesting phenomena to experience and watch.
Have you ever seen a bioluminescent algae show? Let us know in the comments below
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Article written by Rutger Thole who is an avid scuba diver and loves to travel, dive and write about scuba diving. Based in Amsterdam he runs bookyourdive.com and at least twice a year he plans a dive trip of the beaten track.