Phytoplankton

Phytoplankton are very tiny living things that float in the ocean. They are like plants because they use sunlight to make food. This is called photosynthesis. Even though they are small, they feed most of the sea life on Earth.

How They Make Food

Phytoplankton live near the top of the water where sunlight reaches. They use sunlight, water, and a gas called carbon dioxide to make their food. This is the same thing trees and grass do on land. As they make food, they also make oxygen. That oxygen goes into the water and the air.

Food for the Sea

Tiny sea animals eat phytoplankton for their meals. Then small fish eat those tiny animals. Big fish eat the small fish, and on it goes. Even the largest animals like whales depend on phytoplankton. Without them, the ocean food chain would fall apart.

Fun Facts

• Phytoplankton can turn parts of the ocean bright green when there are lots of them.
• They make about half of the oxygen we breathe.
• Some phytoplankton are shaped like tiny glass jewels.

Did You Know?

Satellites in space can see huge clouds of phytoplankton floating in the ocean from far above Earth.