Algae are a large and diverse group of aquatic organisms that can be distinguished from other plant life by their simple structure.
Most algae are single cells that float in the water, but some forms are multi-celled. Algae range in size from microscopic to giant kelp over 100 feet long.
Algae are an essential part of the global ecosystem. They produce oxygen and help to remove carbon dioxide and other pollutants from the air.
Algae can be found in fresh and salt water. They can also be found on land, soil, and rocks.
Blue-green or green algae are the most common types of algae. They are usually found in freshwater, but can also be found in salt water. Green algae range in color from olive green to bright green.
Algae are also a food source for fish, animals, and humans. Some types of algae can be used to make health supplements for treating high blood pressure and as protein supplements.