Constant progress within science and technology helps shed light on secrets related to life as well as wisdom and the real purpose behind many phenomena. Science also helps us to realize that many events we assume to be unconnected actually exist in harmony and solidarity with each other.

Our world is like a giant aquarium: 71% of its surface is covered with water, and it has a lamp, a heater, and air pumps, and there are biological systems for cleaning and food supplies.

This giant aquarium covers a surface area of 361 million square kilometers; its volume is 1.3 billion cubic kilometers, and it has an average depth of around 3,700 meters—and a maximum depth of 10,994 meters (the Mariana Trench). A wide range of interesting creatures, each having unique biological characteristics—from 30-meter-long whales to microscopic plankton [1]—live within this magnificent aquarium. Since the Sun lights up only the upper zones of the seas, the remaining majority is always in darkness. Certain temperature and depth ranges provide natural living environments for certain species.

The night lamp

Bright moonlight is a significant factor for the growth of larval fishes [2]. When the moonlight emerges, the larval fishes approach the surface of the sea while the predators that feed on them simultaneously move to the bottom.

In a study carried out on the larval fishes of the sixbar wrasse (Thalassoma hardwicke), in the family Labridae, known for its thick lips, it was found that their growth rate was maximized with the rise of the moon—i.e., when the first half of the night was dark, and the second half of the night was bright. Yet, the light mentioned here was not just light from any source, but the light coming from the rising moon. It was also found that lunar phases were significant, too: the new moon provided the most efficient time period for growth whereas the full moon was the least efficient time for growth. In addition, cloud-covered nights had a negative effect on growth.

Upon the emergence of moonlight, the zooplankton, the tiny animals on which the sixbar wrasse feeds most, approach the surface, while the lantern fishes, a major predator, stay deep under the sea. Meanwhile, the plankton called “Noctiluca scintillans” emit blue light under the moonlight via a chemical process called bioluminescence. In lamps invented by mankind, a significant portion of energy dissipates in the form of heat; bioluminescent fish and plankton lose no energy. It was also found that the ecosystem is harmed by the intensive artificial light and surface pollution in coastal cities. It is certain that more effective ways of managing of fisheries needs to be developed.

The heater

The heater of this magnificent aquarium is the Sun. The amount of light that penetrates into the oceans and seas depends on the position of the Sun at any given moment, as well as the density of the water. Most of the sunlight that hits the surface of the water is reflected back. The red wavelengths are absorbed by water molecules in the top few meters of the water. The yellow and green wavelengths can penetrate a bit deeper, while the blue and purple wavelengths can penetrate as deep as 1 km. On the other hand, the blue surface color is the result of a variety of factors, such as dissolved chlorophyll.

The water in the part of the oceans below 1,100 meters, called the “deep zone,” is colder and consists of almost 80% of the total ocean volume. The average temperature of the world’s oceans is only 3.9 °C.

The upper 200 meters of the ocean, called the “sunlight zone,” is the part of the ocean where photosynthesis takes place, and it is also the zone which contains most of the biodiversity. The plants that live in the parts of the ocean deeper than the sunlight zone are unable to photosynthesize. For the survival of life in the depths, another source of heat is granted, in addition to the Sun. This source consists of the hydrothermal (hot water) channels that extend from magma to the ocean floor. Hydrothermal vents, containing mostly sulfur compounds of volcanic origin and fine-grained clay minerals, form the basis of special ecosystems, where the organisms are specially created to live in such environments.

The oceans and seas are equipped with unseen water pipelines. These are the ocean currents, which have been perfectly designed to bring food and increase the diversity of species. They also help create global heat transmission, which plays a dominant role in shaping the climate of many of Earth’s regions. One of the most striking examples of this is the hot water current called the Gulf Stream. The circulation of hot water guided by this stream along a specific course makes northwest Europe much more temperate than any other region at the same latitude.

The food

“And We have sent down iron, in which is stern might. And it has a lot of benefits for humankind. So that God may mark out those who help (the cause of) God and His Messengers, though they do not see Him. Surely God is All-Strong, All-Glorious with irresistible might” (Al-Hadid, 25).

The common opinion about the phrase “We have sent down” in the Qur’anic verse above is that the iron in our world came from the gigantic stars in space. Heavy metals like iron are created at the cores of giant stars. Iron can only be produced in giant stars, which are much larger than the Sun, at temperatures up to a several hundred million degrees. The Sun’s temperature of about 15 million degrees does not suffice to form iron. When the amount of iron in these stars exceeds a certain level, the star cannot withstand it and explodes—also called a “supernova.” Meteoroids that contain iron are dispersed into space, and they travel until they are caught in the gravity of a celestial body and merge with it. Not only iron but also other elements such as nickel (⁵⁹Ni) came to our world from outside the solar system.

Another opinion suggests that thousands of small and large meteoroids, known colloquially as shooting stars, scatter by colliding with our atmosphere and descend to the Earth in the form of dust. Asteroids enter the atmosphere at a very high speed, are heated due to friction and burn to pieces, with a significant portion of them turning into dust. Iron atoms abundant in this dust are a source of food for plankton in the oceans, which have a vital role in the production of most of the oxygen produced through photosynthesis, and thus in the life chain on Earth. This dust is an important source of the iron that the plankton need for photosynthesis.

Iron-rich grains of sand that reach the oceans after sandstorms in great deserts are assigned the same duty: ensuring the proliferation of phytoplankton, followed by a plenitude of fish in certain periods.

According to a study carried out by the Marine Mammal Institute at Oregon State University [3], the blue whale, one of the largest mammals, feeds on krill [4], one of the smallest creatures; krill feed on zooplankton, which in turn feed on phytoplankton. In other words, the beginning of the chain of life is connected to the existence of plankton, while the viability of plankton depends on the iron sent from space by meteors, like food provided to an aquarium tank.

This magnificent aquarium, which is home to about 230,000 identified species iso far, still has secrets waiting to be discovered. According to the US National Oceanic and Atmospheric Administration, 95 percent of the ocean floor is yet to be explored. Today, the surface of Mars is better known than the deep oceans. Due to risks such as the high pressure, more people have gone into space than to the deep ocean floor.

As scientific developments progress, it is understood that a thing is not just what it seems, and life is full of wise and hidden purposes that we do not know or understand. The sheer interconnection of the visible and invisible parts of the entire ecosystem continues to amaze fair-minded scientists. The connection between moonlight and the unicellular plankton that produce bioluminescence, the magnetic protective shield that produces the aurora borealis, and shooting stars that provide sustenance to some sea creatures in the form of iron dust, are perfect scenes offered for our observation.

Notes

1. Microscopic creatures that aquatic animals feed on.
2. Jeffrey Shima et al. Lunar rhythms in growth of larval fish. Proceedings of the Royal Society B: Biological Sciences, 2021, 288. 20202609. 10.1098/rspb.2020.2609.
3. “PNAS Study: Migrating blue whales rely on memory more than environmental cues to find prey”, today.oregonstate.edu/news/pnas-study-migrating-blue-whales-rely-memory-more-environmental-cues-find-prey
4. “Krill”, en.wikipedia.org/wiki/Krill

I am sure that there are a lot of people who’ve found themselves in a similar situation to the man above. Unfortunately, most of us are usually not aware of the things happening in this universe. One of the things we tend to overlook is the cleanliness of nature. This is a topic which needs to be considered carefully, but I will just touch on some important aspects of this issue.

First, let’s look at the oceans. The oceans cover three-fourths of the Earth’s surface. There is a bigger world under the ocean than above it. This huge mass hosts jelly fish and tuna, dolphins and octopus, crabs and plankton, sea stars and sea plants. Currently, there are 120,000 species living in the ocean. This is just the number of the species, and doesn’t account for how many variations there are within each species. When we consider the number of living organisms, there are millions of them. Every single day, lots of these organisms die. If there are millions of organisms and thousands of them die each day, then why cannot we see them on the surface of the ocean? Even if these dead organisms are very small, such as plankton, which has a size range from 0.2 m to 20mm, when millions of their dead bodies cluster on the surface, we should be able to see them. The answer lies in a perfect arrangement. For example, the job of cleaning the dead bodies of plankton (also the live bodies!) is performed by fish, sharks, and whales. A large percentage of the daily diet of these animals depends on plankton. Since these animals perform their job well, it is impossible to see any dirt that would have been caused by the dead plankton.

It might seem easy to get rid of the dead bodies of plankton, because they are small organisms. But what about big animals such as whales? What happens to dead whales? Let’s consider the cleaning of dead whales. When a whale dies, its dead body sinks to the bottom of the ocean. This is called a “whale fall” by scientists. There are a lot of species whose diet depends on dead whales. In 1988, a group of researchers at the University of Hawaii found that there are at least 12,490 single organisms which supply their daily diet from a whale fall in the deep North Pacific Ocean. After bigger organisms, such as fish, finish their job, which includes eating the flesh of the dead whale, the other cleaners come to the scene to perform their roles. At this part of the fall, bacteria play a key role in cleaning the bones left from the whale fall. This is not as easy as it might seem. Actually, it takes several years to really clean the dead body from the bottom of the ocean. This is not just a cleaning process at all. While the whale fall is being cleaned from the bottom of the ocean, the ecosystem is supported by the energy from the dead whale.

This cleaning process is not only seen in the oceans, but also on the land. Even though it is more apparent than undersea, we are not totally aware of the cleaning process on land. Decomposition is the chain of events by which a dead organism breaks down to its smaller parts. We must stop here and ask this question: “What would happen if these dead organisms stayed on the land forever?”

So let’s look at what happens to a dead animal on land.

When an organism dies, the process of decomposition starts shortly after its death. There are some stages in the decomposition of an animal. Shortly after the death of the organism, the enzymes in the cytoplasm of the cells start to break down the tissues. This process is called autolysis. It is one of the stages of decomposition in which bacteria plays a role. Bacteria start to break down the tissues. This is called putrefaction. Bacteria are not the only players who have roles in this process. Besides them, some fungi, insects, and even some carnivores are also involved. Live animals, water, air, and temperature (higher temperatures increase the decomposition rate) also help this process. During this time, fungi and bacteria, by using compounds from the dead organisms, convert carbon to carbon dioxide and organic nitrogen to ammonium (NH4+), and so they contribute to both the Carbon and Nitrogen Cycle. After this process is done, many organisms living in the ecosystem have benefitted. At the end of this cycle, soil is enriched with new nutrients which will help the new plants to grow up and the Carbon and Nitrogen cycles are enhanced.

By looking at the processes above, as well as other cycles (e.g. the Carbon cycle), it can be said that the Earth has its own recycling system. While modern societies have only recently understood the importance of recycling, Earth has been using this system thanks to the arrangements given to it.

The things shown here are just some examples of the extraordinary systems existing on the Earth. These systems have always been like this, since the very beginning of the universe. These perfects systems in nature perform their tasks without any human help. The only thing for us to do is to appreciate this harmony, understand its value, and keep it going for the next generations.

These tiny and mysterious creatures of the water are called Plankton; included in these are passively floating or weakly swimming animals and plants. The word plankton comes from the Greek word “planktos,” which means “to drift.” The plankton that drifts in the ocean currents are among the most abundant creatures of the planet. A bowl of water taken from an ocean consists of millions of these tiny organisms; they cannot be perceived by the naked eye. The only way to really become familiar with these creatures is to find them and observe them with the help of a video scope or a microscope. Many marine plants and animals go through a stage in their life cycle when they are plankton, but they ultimately outgrow this stage. These types of creatures are called meroplankton. Unlike meroplankton, holoplankton are tiny creatures which live their whole life as plankton.

Plankton are also classified as either plant plankton or animal plankton. Phytoplankton is the scientific name for plant plankton, whereas zooplankton is the term used for animal plankton. Phytoplankton are usually smaller than zooplankton and it is hard to observe them even under the microscope. Most of the food chains in the ocean begin with phytoplankton, which are eaten by tiny zooplankton. These tiny zooplankton in turn are eaten by larger animals living under the water, including sharks and blue whales.

Since plankton are at the bottom of most of the food chains in the ocean, anything that causes damage to their lives may effect many other organisms. Losing large numbers of plankton may affect the abundance of krill, which is the main diet of whales. Phytoplankton produce oxygen that people breathe; therefore a decrease in the number of phytoplankton may cause problems for human beings. Most plankton live near the surface of the oceans. Pollution, especially that caused by chemical pollutants, has a direct impact on the water at the surface. This is a great threat to plankton populations. Plankton are not only critical for their role in the food chain, but they are also important for their usage in the production of valuable minerals. Ancient deposits of plankton, which were buried under the seafloor and later mined, have become important sources of oil, shale, and many other valuable minerals.

Like land plants, phytoplankton fix carbon through photosynthesis, making it available for higher trophic levels.¹ The major environmental factors influencing phytoplankton growth are temperature, light, and availability of nutrients. Phytoplankton can undergo rapid population growth or “algal blooms” when water temperatures rise in the presence of excess nutrients. While increased phytoplankton populations provide more food to organisms at higher trophic levels, too much phytoplankton can harm the overall health of the oceans. During these blooms, most of the phytoplankton die and sink to the bottom, where they decompose. This process depletes the bottom waters of dissolved oxygen, which is necessary for the survival of other organisms, including fish and crabs.

Major groups of phytoplankton include: diatoms, golden-brown algae, green algae, blue-green algae, dinoflagellates and crypto monads. Phytoplankton are being used as indicators of environmental conditions within the oceans because their populations are especially sensitive to changes in nutrient levels and other water quality conditions.

Zooplankton are planktonic animals that range in size from microscopic rotifers to macroscopic jellyfish. Their distribution within the oceans is governed by salinity, temperature and food availability. The zooplankton community is composed of both primary consumers, which eat phytoplankton, and secondary consumers, which feed on other zooplankton. Zooplankton can be classified into three size classes: Microzooplankton-protozoans and rotifers, Mesozooplankton-including copepods and invertebrate larvae, and Macrozooplankton-including amphipods, shrimp, fish larvae, and jelly fish. Zooplankton, like phytoplankton, are excellent indicators of environmental conditions within the oceans, because they are sensitive to changes in water quality.

The most common animal in the plankton group is the copepod. There are more than 7,500 species of copepods. Copepods are small shrimp-like animals.

Copepods have appendages that are used like paddles for movement. They eat diatoms and other plankton and in turn are eaten by other, larger, drifters. A single copepod can eat an average of 200,000 diatoms a day.

Amphipods, which are the main diet of the gray whale, look like a cross between a shrimp and an isopod. The amphipod typically ranges in size from 2 to 50 mm, although a few may be larger. Amphipods are common in aquatic ecosystems throughout many parts of the world, inhabiting marine, brackish, and freshwater environments. A few species also live in terrestrial ecosystems.

One of the most interesting plankton species is the barnacle. It lives in the upper zone of the oceans where the water only comes at high tide. The appearance of a barnacle is rather deceptive. At first glance it looks like a mollusk, but when you observe the larva of the barnacle the truth becomes clear. Barnacles cause serious problems on the hulls of ships and buoys.

Jellyfish, which are basically nothing more than a large stomach with long tentacles, are also plankton. Their tentacles have stingers on them which they use to catch and paralyze food and then bring it to their stomachs. They move through the water by pumping their stomachs. For the most part they move up and down in the water, letting the currents carry them from side to side.

Copepods, amphipods, jellyfish, and barnacles are some of the most abundant and well-known examples of plankton. The oceans of the world contain a world of tiny organisms; most of them invisible to the human eye and yet these are the basis for nearly all the life in the sea. Our awareness of these tiny creatures will help enhance our appreciation of God’s uniqueness and greatness. The more we learn about the mysteries of the deep, the more we believe in the existence of God.

Footnote

1. Trophic levels: Producer, primary consumer, secondary consumer, tertiary consumer.