This lesson has students investigate three broad ocean habitats—the intertidal zone, the pelagic zone (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 answer questions about what they find, and conclude by writing paragraphs describing what would happen if marine animals were placed in the wrong levels 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

Students will

• discuss the differences between different depth levels of the ocean;
• use the Web to research marine animals and their adaptations to varying ocean depths;
• answer questions about their research; and
• write paragraphs describing what would happen if marine animals were placed in the wrong levels of the ocean.

Write the word "adaptation" on the board, and ask students to define this word as it relates to animals. Why do animals have special adaptations to their habitats? What examples of animal adaptation can students think of close to home? What types of adaptations in marine animals have students learned about?

Have students look at the diagram of cephalopod ocean habitats. Ask them to convert the depth from meters to feet by dividing the numbers on this chart by 3.28.

Discuss the significance of the depths shown on this diagram: How many miles (5,280 feet) deep is the deepest part of the ocean shown here? (Make sure students realize that the ocean actually reaches down to about 36,000 feet.) What range of depths does the pelagic zone (open ocean) cover?

Have students write one-sentence definitions of the following terms: intertidal zone, epipelagic zone, mesopelagic zone, bathypelagic zone, and abyssal benthic zone (abyss). Discuss these definitions as a class, and explain that the three pelagic zones are considered the "open ocean."

Ask students to describe the differences in pressure, temperature, and light in 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.

Have students use the Web sites listed below to learn about marine species and their special adaptations. As they go through the sites, they should answer these questions:

• Name three species that live in the intertidal zone.
• How do animals of the intertidal zone deal with rocks and waves?
• How do animals of the intertidal zone keep themselves safe from predators?
• What is one example of an intertidal predator, and how does it capture and eat its prey?
• Name three species that live in the pelagic zone (open ocean).
• List two ways that each of these open ocean species has adapted to its habitat.
• Name three species that live in the abyss.
• What are three adaptations of animals of the abyss? How do these adaptations help them survive?

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

Ask students to imagine this scenario:

A scientist has collected several species of ocean animals to study in a laboratory. The animals have been living in aquariums and have been given suitable habitats, including pressure and temperature control. Unfortunately, the scientist has hired an assistant who doesn't know much about marine animals and isn't smart enough to ask the right questions—a big mistake for the scientist!

At the end of the research period, the scientist asks this assistant to board a boat on the ocean and release the animals back into their natural habitats. Lo and behold, the assistant gets them all mixed up, placing the deep sea creatures into the shallow waters of the intertidal zone, the animals of the intertidal zone into the open ocean, and the animals of the open ocean into the abyss. Ugh. What will become of these animals? What will become of other animals in the ecosystem? Discuss students' ideas as a class.

Have students write paragraphs answering the above questions, based on the scenario you have read to them and specific things they've learned in this lesson.

Divide the class into small groups, and have each group create a game that challenges other groups to match marine animal adaptations with the parts of the ocean where the animals live.

First, have groups make "game boards" that depict the three major ocean layers they've learned about: the intertidal zone, the pelagic zone, 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 they 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.

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