In this lesson, students will learn about three broad ocean habitats—the intertidal zone, the open ocean, and the abyss—and find out about some specific adaptations animals have made in each of these regions. They will conduct Web research and list some of the things they notice about animal adaptations in the ocean. Students will conclude by designing games to help other students match species and their adaptations to appropriate parts of the ocean.

Geography, life science

Standard 8: "The characteristics and spatial distribution of ecosystems on Earth's surface"

Two to three hours

• Computer with Internet access
• Construction paper
• Drawing materials (e.g., crayons, colored pencils)
• Scissors
• Blank white paper

Students will

• discuss the depth of the ocean in different places;
• brainstorm marine animals adaptations;
• use the Web to research marine animals and their adaptations to varying ocean depths;
• list information they learn in their research; and
• design games about ocean animals.

Draw a simplified version of this diagram of cephalopod ocean habitats on the board. Your drawing should show the intertidal zone, the three pelagic layers (epipelagic, mesopelagic, and bathypelagic) and the abyssal benthic layer. You may combine the pelagic layers into one layer that you call "open ocean." The diagram should also show the depths in feet; you'll need to convert the meters into feet by dividing meters by 3.28. [Note: You can also have students look at the diagram directly on the computer, but you'll need to have them convert the depths into feet for them to have a better understanding of how deep the water is.]

Explain to the class that this diagram shows different depths of the ocean. The intertidal layer is the shallowest part—the animals that live here are actually above the water line when the tide is out. If students have been to the ocean, they may have seen some animals and plants living in this intertidal zone. Below the intertidal zone, the three pelagic layers are also known as the "open ocean" (you can use this term throughout the lesson to simplify the concept for your students). The abyssal benthic zone (abyss) is the floor of the deep ocean. As students probably know, animals can be found at all these ocean levels.

Have one or more students measure the length of the classroom with a tape measure or yardstick. Compare that measurement to the depths of the shallowest parts of the ocean, such as the intertidal zone and the epipelagic zone. How many times would their classroom fit (if turned on its side) into this part of the ocean?

Write on the board "1 mile = 5,280 feet." Help students figure out a landmark in your town that's about one mile from school, such as a store or park. Then have students compare that distance to the distances on the chart. How many times would they walk to that location to reach the same distance as the deepest part shown on this chart (about 10,000 feet)? (For older students who are good at math: How many times would they walk to that location to travel the same distance as the deepest part of the ocean, which is about 36,000 feet?)

Discuss the differences in pressure, temperature, and light between the different layers of the ocean. Where is it the darkest? Where is it the coldest? Where is the pressure the greatest? Students should realize that it gets colder and darker and pressure increases as one descends into the ocean.

Discuss the meaning of the word "adaptation" as it applies to animals. How are animals adapted to their habitats? What examples of animal adaptation can students think of close to home? Have they learned about any special adaptations of ocean animals?

Divide the class into groups of four or five. Ask groups to brainstorm the adaptations that animals might have developed to cope with the low light, cold water, and high pressure in deep water. They should list as many ideas as they can think of.

Discuss groups' lists as a class, and explain that they'll now do some Web research to see how accurate their predictions were and to learn about some actual animal adaptations to ocean life.

Have groups use the following Web resources to learn more about species and their adaptations in the intertidal zone, the open ocean, and the abyss. Ask them to list at least two species for each of these three ocean regions, and then have them list one or two adaptations that these species have made to their habitats.

Intertidal Zone
Monterey Bay National Marine Sanctuary: Virtual Tide Pool (click on the species to learn more about them)
PBS: Nature—Virtual Tide Pool

Open Ocean
Monterey Bay Aquarium Habitats Path: Open Waters

Deep Sea (Abyss)
PBS: NOVA Online—Into the Abyss
Voyage to the Deep: Creature Features

Discuss students' lists as a class. What animals have they learned about? How have these species adapted to their ocean habitats? How does the information students have gathered at the Web sites compare with the predictions they made about how animals might adapt to life in the ocean?

Have groups design games that they can trade with other groups. Their games will challenge the other groups to think about how ocean animals adapt to various parts of the ocean. The object of the games will be to recognize adaptations and associate them with specific parts of the ocean.

First, have groups make "game boards" that depict the three major ocean layers they've learned about: the intertidal zone, the open ocean, and the abyss. They should draw these "boards" on large pieces of construction paper.

Next, have groups make cards that represent the species they've learned about. They can make these cards by cutting pieces of paper into smaller rectangles. Each card should have a number to identify it. It should also contain one or more clues about an ocean animal. For example, a card might say "1. This animal attaches itself tightly to rocks."

To complete their games, have each group make a numbered list of the cards they've created. Each number should correspond to the number of a card and should state the name of the animal the card refers to and the part of the ocean where it lives. A list item corresponding to the above example would say "1. California mussel."

Have groups trade games and play them. Instruct students to look at the cards one at a time and place them onto the game board in the location where they think they belong. For example, they would read the above clue about the California mussel and place that card in the intertidal zone.

To modify this lesson for grades K-2: Divide the class into six groups. Assign each group to one of the following ocean levels: intertidal zone (shallowest part of the ocean), open ocean, and abyss (deepest part of the ocean). You'll therefore assign each ocean level twice.

Draw a sketch of an ocean cross-section on the board, showing the shallow and deep parts as well as the open ocean. Discuss what it's like at the different depth levels: the uppermost levels are warmest and lightest, while the abyss is cold and completely dark.

Have groups visit the Web sites for their assigned ocean levels and sketch pictures of the creatures they see and the habitats where they live.

Give each group a large piece of poster paper, and ask the students to draw their ocean habitats, including some of the animals that live there.

Have students share their posters with the rest of the class and explain what it might be like for animals who live there.

As an additional option, have students create (by drawing or making models) their own ocean animals that might live in their assigned parts of the ocean. These animals can be fanciful but must show evidence of special adaptations to the conditions in which they live. For example, students assigned to the abyss might create a creature that wears a fur coat and has a large flashlight attached to its head.

This lesson is made possible by a generous grant from the National Oceanic and Atmospheric Administration National Marine Sanctuary Program.

Cephalopod Ocean Habitats
Monterey Bay Aquarium Habitats Path: Open Waters
Monterey Bay National Marine Sanctuary: Virtual Tidal Pool
PBS: NOVA Online—Into the Abyss
PBS: Nature—Virtual Tide Pool
Voyage to the Deep: Creature Features