Establish Prior Knowledge
Call on students to describe what a food web is and how it functions. Ask them what they think would happen if the species at the bottom of the food web began to decline. Tell students that in the Snapshot they are about to see, they will learn about a melting ice shelf in Antarctica and how it is affecting the food chain.
Have students view the Snapshot and read the synopsis. Use the following questions to guide a class discussion:
- How are warming trends affecting the Antarctic ice shelf?
- What conditions do phytoplankton need for growth?
- How is the decline of phytoplankton affecting the Antarctic food web?
- What species is finding the warming trend beneficial?
Point out that the snapshot focuses on phytoplankton, krill, and penguins. Ask students what other animals in the food web will might affected. Have them consider leopard seals, whales, skuas, arctic terns.