marinealgae

2. A group of simple, plant-like organisms that grow in salt water and make food from sunlight.

Scientists study marine algae to learn how ocean food chains work.

3. Seaweed used as food or fertilizer.

Farmers spread dried marine algae on their fields to help crops grow.

4. Microscopic ocean organisms that produce much of Earth's oxygen.

Tiny marine algae in the sea help make the air we breathe.