Sea animals, including various fish and squid, tiny creatures called crustaceans, and even algae, produce light, which is known as bioluminescence. They do this to either confuse predators, attract animals they want for food, or get the attention of possible mates.
We can see this amazing natural light show in various coastal waters when bioluminescent algae or plankton are in the water, producing bioluminescence.
1. What are Bioluminescence and Bioluminescent Plankton?
Some animals and plants, whether on land or in the ocean, can emit light inside their bodies through special chemical reactions.
This ability to produce light which makes the sea sparkle or gives it a blue glow, is known as bioluminescence, and it occurs because of a chemical reaction called chemiluminescence.
When certain chemicals are mixed together, they produce energy that makes other particles vibrate and create light, making the bioluminescent organisms glow.
The chemicals responsible for making plankton glow are luciferin molecules, and the light is generated through a series of reactions triggered by a substance called luciferase.
Bioluminescence is quite common in glowing plankton and comes in various forms; it is a type of cold light or luminescence.
2. The Bioluminescent Light
When living things produce their own light, the colors and patterns can be very different. In the ocean, most glowing light is blue-green, and it’s easier to see in deep waters. Sea creatures usually see best in these colors and can’t see colors like yellow, red, or violet.
On land, many creatures also glow in blue-green, like fireflies. But some glow in yellow, like a special land snail in Southeast Asia.
Only a few creatures can glow in more than one color, and one such example is the railroad worm – its head glows red, and its body glows green. Different parts of the creature’s body use different colors to shine.
Certain fungi in decaying wood always give off a steady glow called foxfire. Most of the time, animals use their light to flash on and off for a short time, like a few seconds.
Some creatures have specific spots that light up, like dots on a squid, while others can make their whole body light up.
3. Why do Organisms Use Bioluminescence?
Bioluminescence serves various purposes, and one of its key functions is to help organisms evade predators and act as a defense mechanism. For example, dinoflagellates, a type of plankton, use bioluminescence to protect.
When disturbed, dinoflagellates produce light, a quick flash of light that lasts only a fraction of a second and this light flash is not just a random occurrence but a strategic move.
The purpose of the flash is to attract the attention of potential predators towards the creature that is disturbing or trying to consume the dinoflagellate in the deep sea.
The sudden burst of stimulating light surprises the predator, making it reconsider its actions. The predator becomes concerned about the possibility of other predators being attracted to the scene, diverting its attention away from the dinoflagellate.
This clever use of bioluminescence by dinoflagellates not only helps them avoid being eaten but also creates a moment of confusion for the predator, making it less likely to prey on the glowing organism.
Thus, bioluminescence in this context acts as a defensive strategy, aiding in the survival of the organisms employing it.
4. Which Plankton are Bioluminescent Plankton?
Bioluminescent organisms produce light. The tiny ones in the ocean are called Plankton, and Plankton are small living things that float in the ocean and are an important food source for fish.
Some types of plankton, like tiny animals and single-celled organisms, can glow in the dark. The most common glowing plankton are called Dinoflagellates.
They’re like tiny, single-celled plants known as fire plants. When you see sparks of light in the water, like glowing waves in neon blue, especially at night, it’s likely caused by these tiny glowing marine animals called dinoflagellates or other small creatures like copepods.
Dinoflagellates can move with the help of special protein strands on their bodies called flagella in the dark ocean.
5. Where will you Find Bioluminescent Plankton?
You can discover glowing plankton in different parts of the world’s oceans, especially during night. These fascinating tiny creatures are mainly found in oceans and seas and sometimes even in big freshwater areas.
Where they are found depends on things like how warm the water is, how salty it is, the nutrients around it, and if there are animals that might eat them.
One famous kind of glowing plankton lives in the coastal waters of Maldives, Thailand, and Puerto Rico, and people often visit these spots because they have “bioluminescent bays,” where the plankton light up in a beautiful blue-green glow when the water is disturbed, like by waves or movement.
Glowing plankton can also be seen in other parts of the world, such as the Arabian Sea, the Pacific Ocean, and the Caribbean Sea.
Sometimes, the glow happens now and then; in other places, there are lots of glowing plankton together. In certain areas, specific types of glowing plankton are only found there, making each place special and different.
6. Final Thoughts
There are a lot of organisms that are bioluminescent and produce light, which looks like a glow. Various reasons for these creatures and different circumstances might force bioluminescent algae, plant plankton, or other such organisms to do so.
But the sight is absolutely stunning, and it is a sight to behold when you see a wave of bright, beautiful, sparkling light in the deep blue oceans.