Polar Food Chains
Understand polar food chains — in the Antarctic, phytoplankton are eaten by krill, krill are eaten by fish and penguins, and penguins are eaten by leopard seals and orcas; in the Arctic, algae under ice feeds zooplankton, which feeds fish, which feeds seals, which feeds polar bears — and that tiny organisms like krill and plankton are the foundation of all polar life
What a learner can do afterwards
- Construct an Antarctic food chain: phytoplankton → krill → penguin → leopard seal or orca
- Construct an Arctic food chain: algae → zooplankton → fish → seal → polar bear
- Explain why krill and plankton are critical — without them, the entire food chain collapses
The lesson
Every living thing needs food for energy, and in nature, food connects in a chain. One animal eats another, and that animal gets eaten by something bigger. At the icy poles, every chain starts with something so small you can barely see it.
In the Antarctic Ocean, tiny phytoplankton float near the surface and soak up sunlight. Small krill eat the phytoplankton by the billions. Fish and penguins eat the krill. Then leopard seals and orcas hunt the penguins. Each animal passes energy up to the next.
Under the Arctic ice, tiny algae grow and use sunlight to make food. Zooplankton eat the algae. Fish eat the zooplankton. Seals eat the fish. Polar bears hunt the seals on top of the ice. It is the same idea as the Antarctic chain, just with different animals.
Krill and plankton are tiny, but they hold up the whole chain. If they disappeared, penguins, fish, seals, and even polar bears and orcas would run out of food.
Every polar food chain starts with tiny plankton or algae, and every bigger animal depends on it.
Watch it
Where it sits
Learn first
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.