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Ocean Biome

The ocean biome is one type of marine biome.  More than 70% of the Earth’s surface is covered by ocean biome. Ocean biome refers to the five oceans: Pacific, Indian, Southern, Atlantic, and Arctic.

The ocean biome consists of the five oceans.

On average, the depth of the ocean is about 2.4 miles, and the ocean water is cold and salty. The average temperature of the ocean is 4°C (39°F), and every gallon of seawater contains a cup of salt. Therefore, the ocean biome is not a suitable place for many creatures to live in, including humans.

The water in the ocean biome is always moving.

Big waves move water in the ocean.

As you can see, waves curl, splash on the beach, and crash to the shore. Ocean water is constantly moving. The movement of waves is mainly caused by the wind. As the wind blows across the ocean surface, the waves follow the direction of the wind. When the wind blows stronger, waves become higher and larger.

The activity of the ocean is more complex than just looking at its surface. In fact, underneath the sea level is even more active. For example, the majority of volcanic activity actually occurs below the ocean’s surface.

Species Diversity in the Ocean Biome

Humans have studied more than 230,000 species of ocean animals and plants. Approximately 2 million species are still unnamed or undiscovered! Scientists divide the ocean into three layers according to how much sunlight each layer receives. With the different amount of sunlight received, each layer has distinct ecological characteristics.

Zones of the ocean biome

Different zones in the oceans have different species of ocean creatures

The top layer is the sunlight zone, or epipelagic zone. Since this layer is shallow, it can receive plenty of sunlight and heat. It reaches from the sea level down to 200 meters, but it only represents 5% of the average ocean depth. The species diversity in this zone is very abundant because of the sunlight. Many ocean plants, including seaweed, algae, kelp, seagrasses, and phytoplankton, live in this zone. They need access to the sunlight for photosynthesis. They are also the primary food source for a lot of ocean animals. You can also find a variety of ocean animals live in this zone such as sharks, dolphins, turtles, whales, and seals.

Blue whales live in the ocean biome.

The blue whale, the biggest animal on Earth, lives in the ocean biome’s sunlight zone.

Beyond the sunlight zone, it becomes harder for sunlight to pass through. The layer under the sunlight zone is the twilight zone, or mesopelagic zone. It reaches from 200 meters down to 1,000 meters under the sea level. The temperature of this layer is cold, and it does not change season to season. Animals like eels, octopus, and jellyfish live in this layer. 

The last zone, called the midnight zone or bathypelagic zone, is located 1,000 meters below the sea level. No sunlight reaches this area. As a result, this layer is dark and the water temperature is freezing. Animals have to adapt themselves to handle the challenging living conditions in this layer. For example, anglerfish use their illuminated lures to attract and hunt for prey. Other deep-sea creatures such as lanternfish, swallower fish, and vampire squid have their own way to survive.

Written by: ChungLing Wong