The luminous sea...the biological phenomenon that illuminates sea waters

ArabiaWeather - The marine environment is considered a mysterious and beautiful place that embraces diverse and amazing life, and among the charming biological phenomena that occur in the waters of the seas and oceans, the luminous sea appears as one of the most surprising and admirable phenomena. It is a phenomenon that makes the water light up at night in a mysterious and beautiful way, creating It is an enchanting sight that attracts many lovers of nature and the marine environment. In this article, we will discuss the topic of the luminous sea, how this biological phenomenon occurs, and its environmental importance.

How do you light up the beaches in blue?

Answer: The luminous sea or the phenomenon of bioluminescence is a type of rare and magical biological phenomenon that occurs in marine waters around the world. This phenomenon causes the release of a faint light when small marine organisms such as algae and microorganisms passing near the surface of the water move; As living organisms follow various strategies to adapt, survive, and hunt in their changing environments, some of them change their color to suit their surrounding environment, while others choose to pretend to be dead as a survival strategy, and there are those who benefit from biological lighting as a means of survival, such as fireflies, fungi, and certain types of fish. Bacteria and molluscs.

Bioluminescence

According to what was stated by the National Geographic website, bioluminescence is defined as a type of chemiluminescence, which is a term used to describe the process of a chemical reaction during which light is produced within a part of an organism’s body. This type of bioluminescence is known as “cold light,” meaning that Only a small percentage, less than 20% of the light produced, has a thermal effect, and it should be noted that this type of biological lighting is often found in marine organisms, and is not observed in organisms that live in freshwater.

The luminous sea depends on the presence of a substance called "luciferin" in marine organisms, which is a substance that converts chemical energy into light. When these organisms move, they produce rubbing between water molecules, activating the luciferin and releasing light. This light can be blue, green, or even red depending on the type of marine organism and the concentration of luciferin in its body.

How does bioluminescence occur?

Answer: When looking at the chemical reaction that leads to the generation of bioluminescence, we find that it depends on the presence of two unique chemicals, luciferin and luciferase , or what is also known as the photoprotein, and luciferin is the primary compound that actually turns into light through a catalytic oxidation process that occurs by The enzyme known as luciferase, and this chemical reaction produces the characteristic bioluminescence, where the yellow color is dominant in the case of fireflies, while the bioluminescence of lantern fish is characterized by green.

Some luminous organisms produce luciferin on their own, while others depend on absorbing luciferin from external sources, whether as part of their diet, or in the context of symbiotic interactions between them and other organisms. Luciferase, which is classified as an enzyme (an enzyme is a chemical substance that acts as a catalyst for a chemical reaction) , plays a crucial role in this process. Luciferase reacts with oxidized luciferin. This reaction involves adding oxygen to the luciferin, producing a byproduct known as oxyluciferin . The important point here is that this chemical reaction leads to the emission of light, which contributes to explaining the phenomenon of bioluminescence.

Diversity of colors and unknown functions

The manifestations of bioluminescence vary greatly depending on the environment and organism in which it is found. Bioluminescence in marine waters is mainly observed in blue and green colors, and these colors are often more evident in the deep ocean. Furthermore, most marine organisms are sensitive to only blue and green colors, and often lack the physical ability to absorb or process yellow, red, and violet colors.

Most organisms on land glow in different colors, ranging from blue to green. However, there are exceptions, as some organisms, such as fireflies and land snails in tropical regions of Southeast Asia, glow in spectral colors that include yellow. For some few organisms, they can have They glow in more than one color. For example, the railworm, a beetle larva, can glow red in its head, while its body glows green. This is due to a difference in the different luciferases that contribute to bioluminescence in various forms.

Bioluminescence functions

The National Oceanic and Atmospheric Administration's (NOAA) Ocean Explorer website states that bioluminescence is very common in the ocean, at least in the surface region of the water column where 80% of marine organisms living at depths between 200 and 1,000 meters have the ability to luminize. Biological.

In contrast, in completely light-less deep ocean environments, light becomes absolutely vital. Light contributes to survival in those dark conditions in the deep sea, as it helps marine organisms search for food, reproduce, and implement defense mechanisms. However, the mystery lies in the main purpose of bioluminescence, as scientists are still not sure of it exactly.

Although many marine organisms are capable of producing this “living light,” much about the phenomenon remains mysterious. For example, the reason why bioluminescence is so common in the marine water column has not yet been discovered, while the evolution of this phenomenon in freshwater systems remains completely unknown.

The known functions of bioluminescence in defense are summarized in 3 main functions:

Defense

One of the simplest ways to send a frightening message to predators is to use bioluminescence, which emits light through sudden defenses. This behavior is common among prawns, many of which release bioluminescence as a defense. In addition, many species of squid exhibit bioluminescence, either on their bodies or by secreting a luminous chemical from their ink, in order to frighten and distract predators.

Also, when a squid is attacked by a predator, the squid can release a cloud of luminous ink, which distracts the predator and allows the squid to escape. In addition, the squid uses anti-light camouflage technology, where its color mimics its surrounding environment, and blends in with it when it attacks it. A group of predators from below, it has the ability to camouflage and escape quickly. Moreover, bioluminescence can be used as a warning sign against predators to confuse them and encourage them to withdraw, as the predator believes that the prey may be dangerous or toxic.

attack

One of the most famous types of bioluminescence goes back to the small bulb known as an "esca," which dangles in front of the head of an angler fish to attract creatures small enough to lure and attack them. Additionally, counter lighting can be used to mimic the appearance of a school of small fish, fooling the fish below. It makes her think that there is an opportunity to hunt.

Some deep-sea fish have evolved to emit red light, which cannot be easily seen by most fish in deep marine depths; Because this color is absorbed by water at great depths, however, some dragonfish exploit this red bioluminescence as a source of illumination that only they can see, enabling them to sneak up on their prey without being noticed by anyone else.