Ocean Ecosystem Lesson for Kids

Instructor: Heather Jenkins

Heather has a bachelor's degree in elementary education and a master's degree in special education. She was a public school teacher and administrator for 11 years.

The ocean is more than just the waves we see hitting the shoreline; it is a fascinating and mysterious ecosystem. In this lesson, you will learn all about the ocean, its characteristics, location, and the plants and animals that call it home.

Characteristics of the Ocean

Have you ever wondered what it would be like to travel in a submarine? Diving down from the surface of the ocean water until you could no longer see the land or the sky above you could be really exciting. What do you think you would see? Think about this as we explore the ocean ecosystem.

The ocean ecosystem

The oceans are large bodies of salt water that covers over 70% of the earth's surface. Unlike the water you drink, ocean water tastes salty, like licking the salt off of a pretzel.

The ocean can range from a few inches deep at the shoreline to tens of thousands of feet deep. The deepest known part of the ocean is the Challenger Deep in the Pacific Ocean at 36,000 feet deep. Like a cake, the ocean is made up of layers. There are three main layers of the ocean based on the depth of the water.

Surface Zone

Example of the plant and animal life found in the surface zone of the ocean
surface zone of ocean

The first layer of the ocean is the surface zone, which extends from the surface to about 600 feet deep. It is also called the sunlit or euphotic zone. In this zone, sunlight can be seen throughout the majority of the water and the water is relatively warm.

Most ocean life call this zone home. For example, phytoplankton use the sunlight and convert it to energy. These phytoplankton, and other similar organisms, become food for other creatures like turtles and a variety of fish. Sharks, dolphins, whales, jellyfish, and seals also call this zone home. Plants, coral, and algae are abundant due to the presence of sunlight.

Twilight Zone

The second layer of the ocean is the twilight zone, which extends from the end of the surface zone to approximately 3,300 feet deep. It is also called the disphotic zone. During the day, this zone may be slightly lit to dark depending on the depth. The water is much colder than the surface zone and the water pressure is much greater.

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