This lesson asks students to think about how beluga whales survive in icy Arctic and subarctic waters and why they sometimes need to migrate. Students will view and sketch photographs of ice at different stages of thickness, look at pictures of belugas, and discuss how belugas' bodies are adapted to life in the ice. They will conclude by writing and illustrating paragraphs about how belugas survive in the ice and where the whales go when the ice becomes too thick.

Geography, life science

Standard 9: "The characteristics, distribution, and migration of human populations on Earth's surface"

Two to three hours

• Computer with Internet access
• Wall map of the world
• Writing and drawing materials

Students will

• sketch and write words describing photographs of Arctic and subarctic waters;
• hypothesize how sea animals might be able to live in this icy water;
• locate and circle some important physical features of the beluga whale on a printout showing the beluga's body;
• hypothesize how the beluga's special body features might help it survive in icy waters;
• write paragraphs explaining what belugas might do in late summer as the ice becomes thicker and winter approaches; and
• illustrate their paragraphs.

Write the word "Arctic" on the board.

Hold up a globe, and ask one or two student volunteers to point out the North Pole.

Run your fingers over the Arctic region as you introduce students to the word "Arctic." They will see that the North Pole is in the center of the Arctic region.

Point out the differences between the Arctic islands and land masses and the Arctic Ocean. Explain that the Arctic Ocean covers most of this region, including the North Pole. Some parts of the Arctic Ocean are covered with ice all or most of the time, but there's still an ocean underneath that ice. Tell them that they will see some pictures of the ice in a few minutes.

Ask students to describe what they think the weather might be like in this part of the world. They should recognize that it is very cold compared to other parts of the world.

Explain that some people live in the Arctic region, but that it is not an easy place to live. It is much more common for animals to live there. These animals need special features that help them adapt to the cold environment. Some also migrate away from the coldest areas to spend the winters in places that are not as cold. Can students think of times when people might migrate away from cold places in the winter?

Have students look at the following photographs of ice in Arctic and subarctic waters. It would be ideal if you could project the images to the entire class at the same time. If this is not possible, have students take turns looking at the pictures on the computer.

Ice floes in the Northern Bering Sea
A congealed old ice pressure ridge, Alaska North Slope
"Pancake ice" in the Bering Sea
Edge of pack ice, Northern Bering Sea
Winter sea ice terrain of the Beaufort Sea

As they look at each picture, ask them to:

• sketch what the ice looks like; and
• write words describing the ice.

[Note: You may want to have students place their sketches and words into a two-column chart, with the sketches in the first column and the words in the second.]

Discuss students' observations of these photographs. Also discuss these questions:

• In which type of ice do you think it would be easiest for an animal to swim?
• Did any of the pictures show ice that looked impossible to swim in?
• Which picture looks most like winter? Which picture looks most like summer?

Ask students to think about animals that might live in the Arctic Ocean. How could these animals swim in such icy water? What special features might they need? What might they do in the winter when the ice becomes very thick? Discuss students' ideas as a class.

Tell the class that the beluga whale is a special animal that lives in the Arctic Ocean and other waters near the Arctic Ocean.

Show students this beluga distribution map, and explain that beluga live in the purple zone on this map.

Have students look at pictures of beluga whales at these Web sites:

Mystic Aquarium Homepage
Mystic Aquarium: Beluga Whale
Shedd Aquarium—click on "Animals" and then select "Beluga Whale"

Ask students what they think are the most interesting things about the beluga's appearance. List their ideas on the board. Have them draw the outline of a beluga whale, or let them trace a printout of one of the pictures above.

Help students locate the beluga's "melon" (head) and write the word on their drawings. Then ask them to write the word "blubber" in the middle of the whale. Explain that blubber is whale fat. Although we can't see the blubber, we know that belugas have two layers of it under their skin.

Tell the class that the beluga's melon, blubber, and white color help it live in icy waters. Ask students to think about how each of these features might be useful. Provide some hints such as "belugas often swim under the ice but must make their way to the surface to breathe" and "killer whales and polar bears sometimes hunt belugas."

Have students discuss their ideas as a class or with partners. If they work in pairs, have them summarize their discussion in a list of ideas and report back to the class on what they have discussed.

After reviewing the class's ideas, inform students that belugas use the tops of their heads (their melons) to help them break through the ice when they need to get to the surface. Their white skin makes it hard for killer whales and polar bears to see them. Their blubber helps keep them warm. As an option, have students draw pictures of belugas involved in these activities (e.g., surfacing for air, being hunted, and trying to stay warm) to help them understand and remember these concepts.

Ask students to consider what they have learned about ice in the Arctic and subarctic regions, and about beluga whales. What do they think belugas do when winter comes?

Explain that many belugas migrate away from the heaviest ice. They live in ice that is broken into pieces, but they cannot live under solid ice because they must come up for air.

Use the world wall map to point out Alaska and its southwestern coastline along the Bering Sea.

Define the word "bay"—it may be helpful to point out a major bay, such as Hudson Bay, on the world map, and then tell students that there are many much smaller bays all around the world's coastlines.

Ask students to imagine this scenario:

It is late summer in the North. Many belugas are swimming in a bay on the western coast of Alaska. There is no ice in the water. They are eating a lot of fish.

Soon, the bay will have ice in it. It will get much colder. The ice will become very thick. What will the belugas do?

Ask students to write paragraphs explaining how the belugas will deal with the ice. Their paragraphs should address:

• how the belugas use their special body features (melon, white color, and blubber) to survive in an icy sea;
• what the ice will look like as time passes and it becomes thicker; and
• where the belugas might go to get away from the ice as it becomes thicker.

Have students draw pictures to illustrate the things they have discussed in their paragraphs.

Younger students can simply draw the pictures to show the belugas interacting with their icy environment.

Have students go through the beluga slide show. Ask them to create additional slides showing some of the things they have learned about belugas and their adaptations to the ice.

Mystic Aquarium
NOAA Photo Library: Paths Less Taken
Natural Habitat Adventures: Impressions of an Arctic Summer Tour
Shedd Aquarium