Why Is Krill So Important to the Antarctic Ecosystem?

Antarctica

Krill are small, shrimp-like crustaceans that live in the Antarctic Ocean. They feed on small, one-celled algae called diatoms and thrive in the extreme conditions in the Antarctic ecosystem.

Population

Krill fills a huge niche in the polar ecosystem. There may be anywhere from 125 million to 6 billion tons of krill in the Antarctic Ocean each year.

Food Chain

Krill provide most of the food for many Antarctic animals, including whales and penguins. Small animals that depend on krill also may become food for larger predators.

Effects of Reduced Numbers

Reduced numbers of krill are devastating to the food chain. Many animals would starve, and the algae bloom would increase sharply, causing dangerous conditions for fish.

Climate Change

Krill are sensitive to changes in the environment. They concentrate around areas near sea ice. Warming conditions can melt the sea ice and reduce the krill's habitat.

Human Harvesting

Humans in many countries eat krill as a delicacy. People in some countries, including Russia and Japan, harvest millions of krill each year. Over harvesting can also disrupt the food web.

References

• The Mission: Krill
• Polar Discovery: Antarctica