Meet the tiny drifting organisms that quietly power much of ocean life.
Plankton are organisms that drift with ocean currents rather than swimming strongly against them. Although many plankton are microscopic, they play an enormous role in ocean food webs and in producing oxygen for the planet.
Learn how these tiny drifting organisms use sunlight to make food.
Learn MoreDiscover the drifting animals that graze on phytoplankton and each other.
Learn MoreSee how plankton support fish, whales, and countless other ocean animals.
Learn MoreExplore how phytoplankton help supply oxygen to Earth's atmosphere.
Learn MoreLearn what happens when plankton populations rapidly increase.
Learn MoreDiscover how many ocean animals begin life as tiny drifting larvae.
Learn MoreFind out how scientists collect and examine these microscopic organisms.
Learn MorePhytoplankton are microscopic, plant-like organisms that use sunlight, water, and carbon dioxide to produce food through photosynthesis. They live near the ocean surface, where enough light is available, and form the foundation of many marine food webs.
Zooplankton are drifting animals that range from tiny single-celled organisms to larger creatures like jellyfish. Many zooplankton feed on phytoplankton or on each other, transferring energy up through the ocean food web.
Small fish, filter-feeding whales, and countless other animals rely directly or indirectly on plankton for food. Because so many species depend on them, changes in plankton populations can affect the health of entire marine ecosystems.
Through photosynthesis, phytoplankton release oxygen into the water and atmosphere. Scientists estimate that phytoplankton contribute a significant portion of the oxygen produced on Earth, making them important to life far beyond the ocean.
Under the right conditions of light, temperature, and nutrients, plankton populations can rapidly increase in what is called a bloom. Blooms can turn water different colors and provide a burst of food for other marine organisms, though some blooms can also be harmful.
Many ocean animals, including crabs, fish, and sea stars, begin life as tiny drifting larvae that are technically considered plankton. These larvae eventually grow and settle into their adult forms and habitats.
Scientists collect plankton using fine nets, water samples, and specialized instruments, then examine them under microscopes. Studying plankton helps researchers monitor ocean health, track climate patterns, and understand marine food webs.