This lesson outline provides suggestions for how to use existing National Geographic resources about marine ecosystems in the classroom. Resources include illustrations, charts, articles, and videos about marine ecosystems. Select the resources that are most applicable to your classroom and students’ needs to build your own lesson on marine ecosystems.

Grade Level: 5-8

Topics Covered:

  • Biodiversity
  • Habitat
  • Marine Ecosystems
  • Marine Food Pyramid
  • Marine Protected Areas
  • Predator/Prey
  • Symbiosis
  • Trophic level


Students will be able to:

  • Identify the characteristics of a marine ecosystem.
  • Explain how a marine ecosystem functions.
  • Recognize different types of marine ecosystems and locate examples of them around the world.
  • Identify the threats to a healthy marine ecosystem and the efforts to protect them.

Lesson Resources:

Choose a Hook:

  • Watch the National Geographic video Coral Reefs 101 to provide the students one example of a marine ecosystem with great biodiversity. Ask the students to talk about the ways species in a marine ecosystem interact, focusing on concepts such as symbiosis, and why high biodiversity means more symbiotic relationships.
  • Kick off with Kahoot! quiz on marine ecosystems. Get a sense of what your students know or think they know about marine ecosystems.
  • Read about Marine Ecosystems.

Choose activities that will help your students understand the characteristics of ecosystems and how they are threatened and protected utilizing the following resources:

  • (50 minutes) Mapping Marine Ecosystems. Learn about the many different types of marine ecosystems by studying their main features and mapping some of their locations around the world.
  • (50 minutes) Marine Food Pyramid. Study the example pyramid provided, and then have the students research a different type of marine ecosystem, such as the Arctic Ocean or a freshwater lake. Have the students make their own four-level marine food pyramids for their chosen ecosystem.
  • (35 minutes) Coastal Ecosystems. Explore this infographic of a marine ecosystem along the Gulf of Mexico coastline. Examine how different the species are at each layer of the ecosystem, and how fish, birds, and other wildlife depend on the unique nature of each coastal habitat, such as mangrove forests and saltwater marshes.
  • (50 minutes) Each student will research one organism in a marine ecosystem and complete this worksheet that describes the organism, its habitat, its trophic level, its prey and predators (if applicable), and other important characteristics.
  • (35 minutes) Marine Protected Areas. Have your students learn about marine protected areas, and then have them compare and contrast marine and terrestrial protected areas, such as national parks and wildlife refuges. Draw a T-chart on the board. Ask the students to brainstorm differences between terrestrial and marine protected areas. Write the students’ ideas on the board. If needed, prompt the students with the following characteristics:

Terrestrial Protected Areas:

  • Have more discrete boundaries
  • Are more internally controlled by the life processes of the dominant organisms
  • Have people living nearby
  • Have food that is cultured and obtained by farming
  • Have a longer history

Marine Protected Areas:

  • Are subject to forces such as tides, circulation patterns, and shifts in overall productivity
  • Do not have people living within them
  • Have not been established as long
  • Animals and pollutants typically travel longer distances due to global currents
  • Are relatively open
  • Have food that is wild and obtained by fishing

Explain that because of these differences, marine ecosystems require different approaches to studying and managing them.

Read about Marine Ecosystems

  • Have your students read this article on Biodiversity and talk about the factors that can increase biodiversity in an ecosystem or reduce biodiversity.

Choose an assessment:

  • [5 minutes] 5 question Kahoot! quiz on marine ecosystems. If you used the Kahoot! as a hook with your class, debrief the students by asking if their scores improved and why.