The ocean is a vast body of water that covers the majority of the earth’s surface. Around 70% of the earth’s area is occupied by the ocean, which is almost 361.9 million sq kilometers. Oceans have a direct impact on life.
Scientific study says that marine plants create quite half the oxygen in Earth’s atmosphere, making life possible in both oceans & on land to survive.
In addition to this, the oceans also function as climate regulators since they absorb the earth’s surplus heat and regulate the consequences of global climate change by exchanging gases with the atmosphere.
The Ocean Zones
The ocean contains 97% of Earth’s water, and oceanographers have stated that hardly 20% of the planet Ocean has been explored. In descending order by area, the global ocean is divided into five major basins: the Pacific, the Atlantic, the Indian, the Southern, and the Arctic.
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On the basis of biophysical conditions, the pelagic zone comprises all open ocean regions, which is divided into two zones, i.e., Photic and Aphotic zone. Based on light abundance and depth from the surface, the ocean is further sub-classified into several zones for the ease of oceanographic studies:
Photic Zone
The depth of the pelagic zone of the photic zone is extended downwards up to 200 meters from the surface of the ocean.
Sunlight Zone
Aphotic Zone
The depth of the pelagic part of the aphotic zone ranging beyond 200 meters. It can be further categorized into vertical regions based on temperature.
Twilight Zone
- Deep Ocean Zone (It is further divided into three layers)
- Midnight Zone
- The Abyss
- The Trenches
The Sunlight Zone
The Sunlight Zone is also named Surface Zone or Epipelagic Zone due to its position at the ocean’s surface level. It is generally the ocean’s warmer layer during the daytime, as the name indicates Sunlight Zone or Photic Zone.
This zone is extended downwards up to 200 meters from the ocean sheet’s surface, which is about 5% of the ocean’s average depth. At daytime, a surplus amount of sunlight generates heat, which passes down deeper into the water by the cause of the wind’s movement.
The temperature of the sunlight zone is around 97 degrees Fahrenheit. It is the most biodiverse region where photosynthesis can occur. Enough sunlight penetrates through this layer for aquatic plants, which successively creates around 50% of the oxygen in the environment.
At this zone, a large quantity of commercial fishing takes place. Also, various aquatic species survive at the surface zone, such as tuna, whales, dolphins, sea turtles, and sharks.
The Twilight Zone
The Twilight Zone or Mesopelagic Zone is the topmost region of the aphotic zone. It commences from 200 meters and extends downwards, up to 1,000 meters, covering approximately 20% of the ocean’s depth.
It is mainly a very dim region with a temperature of 54 degrees Fahrenheit, a very small amount of sunlight reaches this layer.
The Mesopelagic zone plays a significant role in restraining our planet; the ocean absorbs around 25% of the carbon dioxide released by humans and pushes it down into the deep ocean, thus preventing it from rereleasing into the environment.
The commercial fishing at the twilight zone is untouched as compared with the surface zone. The aquatic life survives in this zone are lanternfishes, cuttlefishes, wolf eels, chain catsharks, and Gonostomatidaes. Apart from this, it is the region where experts have found the presence of bioluminescent creatures.
The Deep Ocean
The deep ocean is the third and last layer of the aphotic zone. It extends from 1,000 meters to the deepest point of the ocean floor, covers up to 75% of the ocean’s depth.
The temperature in this region is below 10 degrees Celsius. No natural light possibly reaches this region, as it is deeper and darker. This zone consists of several bioluminescent organisms that produce and emit their natural light in the dark ocean.
The deep ocean is further sub-divided into three zones: the Midnight Zone, the Abyss, and the Trenches.
Ocean Midnight Zone
The midnight zone is also called the bathypelagic zone, the first layer in the deep ocean’s three layers model. It extends from 1,000 meters to 4,000 meters of ocean depth. The average temperature lies in this region is between 50 and 39 degrees Fahrenheit.
The bathypelagic zone is generally considered the world’s largest ecosystem, as it is fifteen times larger than the epipelagic zone. As there is no natural sunlight in this region, some of the bioluminescent animals lit the whole ocean’s area by emitting their light.
These animals usually use their own light for hunting or finding a mate in the complete darkness of the ocean. Some of the living creatures that survive in this zone are angler fish, snipe eel, opposom shrimp, tripod fish, sea cucumber, black swallower, and vampire squid.
The Abyss
The abyss is also known as the Abyssopelagic Zone, where Abyss signifies ‘no bottom.’ It is the second and the middle layer of the three layers model of the deep ocean. It extends from 4,000 meters down to 6,000 meters to the ocean’s depth and closes to the seafloor.
The temperature in this zone never rises above the near freezing point. Due to extreme frigid conditions, only a few aquatic living creatures survive in this region, such as Viperfish, Eelpouts, and Pelagic fish, including microorganisms and crustaceans molluscan, and varied classes of fishes.
The Trench
The trench is also known as the Hadalpelagic Zone, the third and final layer of the deep ocean. It is the deepest zone of the ocean that extends from 6,000 meters, crosses the abyssopelagic zone in parts of the planet where that’s physically possible; this is often usually within the sort of deep-sea trenches and canyons.
One instance of such a wonder is Mariana Trench in the Pacific Ocean, which marks the deepest location on the Earth at 11,034 meters, a depth so deep that even Everest would be completely drowned if placed at rock bottom.
Although the pressure is so severe at this point, that life does exist in this zone. In 1970, the abyssobrotula galatheae (a species of eel) was discovered at 8,372 meters in the Puerto Rico Trench.
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Conclusion
Oceans form the most extensive set of water and the greatest asset of our planet. It is the reason we have rivers, lakes, and groundwater. Also, the rain we get is due to the enormous evaporation from the seas.
Thus, we must preserve the ocean by stopping the deterioration of seawater, which seriously affects marine life and biodiversity.
