DRIFTERS In a single spoonful of ocean water an entire world exists Plankton are tiny organisms They drift in oceans rivers and lakes Humans can rarely see them Still plankton play a huge role on Earth For example much of the air that humans breathe depends on plankton So do many of the foods that humans eat Plankton can be seen up close under a microscope 5 CHAPTER 1
Even the oil that humans use as fuel comes from ancient plankton Most plankton are too small to see But under a microscope plankton look like plants and animals Phytoplankton are one type of plankton These plankton are similar to plants They can produce their own food Other plankton are similar to tiny animals They feed on other organisms These ones are called zooplankton Plankton get their name from the Greek word planktos In Greek it means drifting Plankton are so small they cannot swim easily Instead wind and water move them around 6
On their own plankton are tiny But they often gather together in huge groups Groups of plankton often float near the ocean’s surface Phytoplankton take in sunlight carbon dioxide and nutrients As they float they give off oxygen In fact half of all oxygen on Earth comes from plankton TYPES OF PHYTOPLANKTON There are many types of phytoplankton Below are some of the most common types cyanobacteria diatom dinoflagellate green algae coccolithophore 7
