Epipelagic Zone Definition | Epipelagic Zone Animals | Epipelagic Zone Pressure
What is the Epipelagic zone?
The Epipelagic zone can be defined as the top layer of the water column (from the surface to 200 meters). This zone accounts for about half of all life in the oceans. Coral reefs are home to diverse and vibrant assemblages of organisms such as fish, crabs, sponges, corals, squid, and mollusks. The epipelagic zone is an excellent area for fishing because there is plenty of life to catch. It also makes up a large component of plankton or algae that form the base food chain in marine habitats.
The epipelagic zone gets its name from being exposed to the sun. Organisms in the epipelagic zone receive their energy directly or indirectly from the sun and are subject to heat, salinity, and light variations. The organisms in this zone are also affected by surface water currents and tides. There is a constant need for movement by these organisms, unlike animals that live in the next deeper layer of the ocean known as the Mesopelagic Zone.
Epipelagic Zone Temperature
The temperature of the epipelagic zone is controlled by two processes. The first is that the sun’s rays are absorbed by water in this zone and re-radiated at different wavelengths. This causes the water to warm up because of a change in density so that cooler, denser water in the deeper layers flows upward.
The second process that controls temperature is that oxygen from air bubbles rises to replace carbon dioxide as a dissolved gas in the water.
Epipelagic Zone Pressure
Another factor that is important to the animals who live in this zone is pressure. The seafloor’s pressure is greater than at sea level because of the weight of water pressing down on it. Although this deep into the ocean, you will not feel any weight from the water; you can be crushed if you were to fall in simply.
The water pressure on a creature living at 2000 m would probably be about 1500 times that of an air-breathing animal such as a human being at sea level.
Epipelagic Zone Fish & Animals
Fish are the most common animals that live in the epipelagic zone. They can see the light, so they have clear eyes. Most fish that live in this zone have silvery-gray or brown bodies.
This is because these colors blend into their surroundings. Fish that live here are usually nocturnal, and they hunt for food at night and rest during the day when it is too bright to see very well.
Epipelagic zone animals include the important tuna stocks and sharks such as the great white shark.
In this zone, there are very few organisms. These include squid, jellyfish, eels, and some species of marine mammals. The zone is sometimes called the disphotic zone. Because light cannot penetrate this deep into the ocean, humans cannot see anything in it.
Epipelagic Zone Characteristics
The sunlight in the epipelagic zone is weak, and because of this, a variety of colors are seen. You can see many different shades of green and blue because these substances absorb the sun’s rays.
Since the water in this zone is clear, you can see all the way to the bottom of the ocean (200m). Therefore, it is also called as “the last refuge.” Normally below 1000m, creatures will be blind as there will not be enough sunlight to power their eyes.
Epipelagic Zone Dangers
The main threat in this zone is from being eaten by a predator. Also, some predators may poison the prey as well. In some cases, certain types of algae may poison fishes if they cannot compete for nutrients. Animals that live in this area include fish, squid, and jellyfish.
Some animals in this depth are able to see and eat other organisms that live in these depths. Others have developed methods to find food and get rid of their predators.
Some animals that grow up in this layer include jellyfish, corals, sponges, plankton, and eels. Many of these organisms possess white hard exoskeletons, which make them well-protected against high pressure.
Fish also have special anatomical adaptations that make them well adapted for low pressures at depth.
Epipelagic Zone Temperature Comparison
Although the epipelagic zone is colder than the mesopelagic, it is usually not much colder than the surface water because of its close proximity. Because of this, many animals are able to survive in this zone despite its cold temperature.
Epipelagic Zone Depth Comparison
The epipelagic zone is deeper than the surface water in which it exists. As such, the layer has a significant influence on life on the lower levels of the ocean. The below table is a comparison of some features that are important in this area.
In this category, fish is an animal that can live at or near the edge of the light. In addition to being a prey item for predators at depth, fish have been observed to carry light as a defensive tool against potential predators at depth.
The Epipelagic zone can extend from the ocean’s surface down to 200 meters (660 feet) deep.
Epipelagic Zone Salinity
The salinity of this zone can change drastically from high to low, freshwater to saltwater. The salinity can vary in the epipelagic zone due to the rains that fall from the sky.
Epipelagic Zone Facts
-In the epipelagic zone, there is a lot of sunlight and little light from artificial light.
-Plants cannot grow in this zone because there is not enough sunlight and nutrients for them to grow.
-Animals that live here are called epipelagic animals because they live in the epipelagic zone.
-The Epipelagic zone is one of the zones of the ocean. This zone is above and below the top layer of water in an ocean that is deeper than 200 meters or 620 feet. There are many other zones in oceans, including tropics, thermocline, euphotic zone, and mesopelagic.
The epipelagic zone is a cold area that can reach temperatures as low as 3 degrees Celsius.
Comparison of the epipelagic zone with other marine environments:
Animals that live in the epipelagic zone
Examples of animals that live in this area include dolphins, tuna, and salmon. Some types of fishes that live in this area are mackerels, tuna, skipjack tuna, and mahi-mahi. The deep ocean creatures are snowflake eel, triggerfish, and squirrelfish.
In conclusion, the epipelagic zone is one of the most important zones in the ocean. Coral reefs need sunlight to survive, and without this zone, these animals would not be able to survive. Besides, humans need sunlight too, so it is also important that the epipelagic zone is protected for our own well-being as well.
The epipelagic zone should be kept safe for future generations. For example, oil spills frequently occur, which can have harmful consequences on the animals’ well-being in this zone.