Polar ecosystems compared
Compare Arctic land and sea ecosystems with Antarctica's small land ecosystems and marine food webs. The Arctic has native land mammals and Indigenous communities. Antarctica has no native land mammals or Indigenous permanent settlements, but research stations are staffed through winter. Both polar oceans depend on phytoplankton and ice algae. Krill are important in the Southern Ocean; copepods and other small animals are important in the Arctic. Climate change can change habitats and food supplies.
What a learner can do afterwards
- Compare Arctic land and sea ecosystems, native land mammals and Indigenous communities with Antarctica's small land ecosystems, marine food webs and year-round staffed research stations
- Explain how phytoplankton and ice algae support polar ocean food webs, distinguishing the importance of Southern Ocean krill from Arctic copepods and other small animals
- Explain how changes in sea ice, temperatures and food supplies can affect polar animals adapted to cold or dependent on ice
1 · Read
The Arctic is an ocean surrounded by land, including tundra. Antarctica is a continent surrounded by the Southern Ocean. Both regions have land and sea life. Antarctica has small land ecosystems, but many of its animals get food from the ocean. Its ocean food webs support penguins, seals and whales. One feeding path is krill to penguin to leopard seal.
Caribou and Arctic foxes are native Arctic land mammals. Polar bears live on land and sea ice. Antarctica has no native land mammals, but it has small land animals, including mites and springtails.
Selin's Arctic photos show caribou and a village. Indigenous peoples have lived in the Arctic for thousands of years, using land and sea resources. Her Antarctic photos show penguins and a research station. Antarctica has no Indigenous permanent settlements. Scientists and support staff work at stations, including through winter. They rely on supplies brought from elsewhere.
Krill are especially important in many Southern Ocean food webs. They eat phytoplankton and are eaten by fish, penguins and other animals. Copepods are especially important small animals in Arctic food webs. They are one kind of zooplankton. Copepods and other small animals pass food from algae and phytoplankton to fish. Penguins and seals eat other animals.
Polar bears hunt seals from Arctic sea ice. They use the ice as a hunting platform. When ice disappears earlier or forms later, bears may have less time to hunt. Sea ice loss can also change the food and shelter available to other polar animals.
Climate change can alter sea ice, temperatures and food supplies. Many polar animals are adapted to cold or depend on ice. If a food source declines, animals that eat it may have less to eat. For example, fewer krill can leave some Southern Ocean animals with less food. Food webs have several paths, so effects vary. A short food chain alone does not tell us how easily an ecosystem could be harmed.
Krill in the Southern Ocean and copepods in the Arctic eat tiny producers and pass food to larger animals. Both regions have land and sea life.
Reading summaries adapted from SubjectToClimate's Polar Bears: Climate Change Lesson and The Arctic: Narrative Writing Lesson, U.C. San Diego's Ocean Warming unit plan, and the Biology and Biology AP Courses critical-thinking question records.
2 · Watch
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