Ocean Zones

Ocean zones are formed by layers within the oceans that contain distinctive plant and animal life. They are occasionally referred to as ocean layers or environmental zones.

An ocean is a major body of saline water and a principal component of the body of water. Approximately 71% of the Earth’s surface extends over by ocean, a continuous body of water that is normally divided into several principal oceans and smaller seas.

The ocean layer or ocean ozone is divided into two large categories known as realms

  • The benthic realm (consisting of the seafloor)
  • Pelagic Realm (consisting of the ocean waters).

These two realms are then subdivided into different zones according to the depth of the water.

The Benthic Realm Ocean Zone

The benthic realm covers a wide range from the shoreline to the deepest parts of the ocean floor. The benthic realm is an especially wealthy environment for living organisms. Approx 98% of all marine species are found in or near the ocean floor. Most are organisms that tunnel in the sand or mud, bore into or are attached to rocks, live in shells, or simply move about on the ocean floor.

The benthic realm extends from the shoreline to the deepest parts of the ocean floor. The benthic realm is an especially rich environment for living organisms. Up to 98 percent of all marine species are found in or near the ocean floor. Most are organisms that burrow in the sand or mud, bore into or are attached to rocks, live in shells, or simply move about on the ocean floor

The benthic zone is the ecological region at the below-average level of a body of water such as an ocean or a lake, it also includes the sediment surface and some sub-surface layers. Organisms that lives in this zone are called benthos. The outermost layer of the soil lining the given body of water, the benthic boundary layer, is an integral part of the benthic zone, as it affects mostly the biological activity which takes place within this zone.

  • Examples of contact soil layers include
    • Sand bottoms
    • Rock outcrops
    • Coral
    • Bay mud.

The Pelagic Realm Ocean Zone

In the pelagic zone from the surface to 660 feet (200 meters), phytoplankton (algae and microscopic plants) live. They are the primary producers of the ocean, the lowest level on the oceanic food web. They use the process of photosynthesis to provide food for themselves and for higher organisms. The pelagic food web is the primary consumer, the zooplankton (microscopic animals). They feed on phytoplankton and, in turn, become food for larger animals (secondary consumers) such as sardines, herring, tuna, bonito, and other kinds of fish and swimming mammals. At the top of this food web are the ultimate consumers, the toothed whales.

In the pelagic zone, the depth is from the surface to 660 feet (200 meters), phytoplankton, algae, and microscopic plants live in this zone. They are also called as primary producers of the ocean, it is the lowest level on the oceanic food web. They produce food by the process of photosynthesis to provide food for themselves and for higher organisms. The pelagic food web is the primary consumer, the zooplankton i.e. microscopic animals. They give food to phytoplankton and, in turn, become food for larger animals i.e. for secondary consumers such as sardines, herring, tuna, bonito, and other many different types of fish and swimming mammals. At the top of this food, the web is the greatest consumer, the toothed whales.

The pelagic zone occupies 1,370 million cubic kilometers and has a vertical range up to 11 kilometers. Fish that live in this zone are called pelagic fish and its life decreases with increasing depth. It is affected by light levels, pressure, temperature, salinity, the supply of dissolved oxygen and nutrients, and the submarine arrangement of the natural and artificial physical features of an area.

The benthic zone is the ecological region at the deeply bottom of the sea. It comprises of the sediment surface and some sub-surface layers. Marine animals or plants that live in this zone, such as clams and crabs, are called benthos. The demersal zone is impartial above the benthic zone. It can be seriously affected by the seabed and the life that lives there. Fish that live in the demersal zone are called demersal fish.

Ocean Depth and layers

Epipelagic (sunlight)

The sunlight surface zone where there is more light as per the requirement for photosynthesis. Due to this, plants and animals are largely present in this zone. Nearly all production for primary produces here in the ocean.

  • This layer is the area of the territory of fish such as
    • Tuna
    • Many sharks
    • Dolphin fish
    • Jellyfish.
  • This zone is called as the surface zone.

Mesopelagic (twilight)

some light penetrates this deep, it is insufficient for photosynthesis. At about 500 m the water becomes depleted of oxygen. Still, an abundance of life copes with more efficient gills or minimal movement. Animals such as swordfish, squids, wolffish, a few species of cuttlefish, and other semi-deep-sea creatures live here. Many bioluminescent organisms live in this zone. Due to the relative lack of nutritious food found in this zone, some creatures living in the mesopelagic zone will rise to the epipelagic zone at night in order to feed.

Some light, not enough penetrates this deep, which is insufficient for the photosynthesis process. At about 500 m the water becomes drain of oxygen. Still, a very large quantity of life copes with more efficient gills or minimal movement. Animals such as swordfish, squids, wolffish, a few species of cuttlefish, and other semi-deep-sea animals live here. Many light emission living organisms live in this zone. Due to the more lack of nutrition and food found in this zone, some creatures living in the mesopelagic zone will rise to the epipelagic zone at night in order to feed for food.

Bathypelagic (Darkzone)

Very few animals can be adapted to survive in the cold temperatures and breathtaking pressures found at this depth.

  • The species found in this zone are several species of squid, echinoderms including the
    • Basket star
    • Swimming cucumber
    • The sea pig
    • Marine arthropods including the sea spider.
  • Many of the species living at these depths have developed gradually to be transparent and eyeless as a result of the total state of being away from light in this zone.

Hadopelagic

Very few species are known to live here in the open areas. However, many organisms live in hydrothermal allow air in this and other zones. Some define the hadopelagic as waters below 6,000 m, whether in a narrow ditch or not. The bathypelagic, abyssopelagic, and hadopelagic zones have similar in character, and some marine biologists merge them into a single zone. The depth plain is covered with soft sludge covered by the dead organisms.

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