Green and blue-green algae are found in freshwater as well as saltwater. Red and brown algae are found only in saltwater and are also called seaweed. Did you know that algae of all four types have ...

Have you ever seen brown or green goo floating on a river or in the ocean? Or have you noticed how the walls of a fish tank sometimes turn green and slimy? These are all examples of algae—but there is ...