Summary:
Working in teams, the students will use pictures to construct both Arctic and Antarctic food webs and then compare and contrast their features. They will analyze the roles of producers, consumers, and decomposers, and then predict the effect that changes in the environment might have on the food webs.

Materials:

For each student team:

• Picture cards of Arctic marine organisms: spectacled eider, clam, amphipod, walrus, polar bear, Arctic cod, seal, ice algae, phytoplankton, zooplankton, Native Alaskan hunter, grey whale, bowhead whale, bacteria, starfish, Polychaete worm, crab, and bacteria
• Environmental factor cards
• Butcher paper, markers

Vocabulary

• marine
• photosynthesis
• producer
• consumer
• decomposer
• phytoplankton

Background For Teachers:

Most organisms that live and thrive in polar regions are marine in nature. They range in size from microscopic single-celled creatures to the largest animals on Earth. Even the ice that floats on these oceans can be teeming with microscopic life. Bacteria, algae, and many small creatures inhabit the hollow pockets and cracks inside the ice or cling to its bottom, while larger animals “hitch” rides on the upper surface. Polar oceans can be among the richest on Earth in terms of the abundance and variety of plants and animals, and all living things in and on these cold waters have adapted to the extreme conditions in a multitude of ways. All creatures in the polar regions share a dependence upon the Sun as the ultimate source of energy. The Sun drives the process of photosynthesis for the primary producers of these marine food webs – the phytoplankton (plants.) Phytoplankton, which is mostly algae, is eaten by the zooplankton (animals), which are then eaten by larger and larger creatures. Some of the larger animals may also feed directly on phytoplankton.

Some marine animals, like seals are found in both the Arctic and Antarctic. However, all but one species of penguins are found in the southern hemisphere, and none are found in the Arctic. On the other hand, polar bears are only found up north. They are believed to have evolved from bears inhabiting continents closer to the Equator and represent the top-level consumer and predator of the Arctic.

Most Antarctic life is found near and along the coast and ice sheets, and the interior of the continent is absent any large animals except one – the research scientist.

Instructional Procedures:

Direct the students to define the biological roles of producer, consumer, and decomposer, and ask them to give specific examples in their local ecosystem. What environmental changes could impact that ecosystem, and how might those changes affect the food webs that comprise it?

Optional: show the Antarctic Food Web sequence from Passport To Antarctica, which shows the relationship of some of the smallest organisms, krill, to the largest, whales.

Procedure

1. Instruct each team to start with either the Arctic or Antarctic set of picture cards and arrange them into a food web on top of a sheet of butcher paper.
2. Use the descriptions on the back of each card to find the role each organism plays within the ecosystem.
3. Once the team agrees on the arrangement of the food web, use the markers to draw lines on the butcher paper that represent producer, consumer, or decomposer relationships between the various organisms.
4. Draw an environmental factor card and read aloud to the team.
5. As a team, discuss how the environmental change might impact the populations of organisms in the food web.
6. Repeat the steps with the other set of cards
7. Compare and contrast the Arctic and Antarctic food webs.

Extensions:

1. This activity can be conducted in an open area with each student holding an organism card. Each student should have researched the ecological niche of “their” creature, and their role in the food web. Use different colors of string or yarn, held by the students, to connect the producers, consumers, and decomposers into the proper arrangement. When any organism is eliminated from the food web as a result of the impact of an environmental factor card, that student should release the string.

2. Use coat hangers, the picture cards, and string or yarn to construct mobiles of the food webs. Display the completed food webs by hanging them from the classroom ceiling.

3. “How many Big Macs = 5,000 calories?” Challenge the students to design a “balanced” daily diet that would equal at least 5,000 calories, the typical daily requirement for scientists working in polar regions. Note: Eating that amount of food is NOT required, or they’ll need to attend P.E. all day!

Bibliography:

Adapted from:

• NSTA IPY Symposium #1 by Jackie Grebmeier and Betty Carvellas, LFAII Teacher’s Guide, p. 33,
• Gulf of Maine Aquarium – Ozone and Phytoplankton

Author:
Utah LessonPlans

Created Date :
Feb 20 2008 13:41 PM