phytoplankton
/ˌfaɪtoʊˈplæŋktən/
noun
- Microscopic plants that drift in water and form the base of many aquatic food webs.
- Phytoplankton produce most of the oxygen in the atmosphere.
- Pollution can cause harmful blooms of phytoplankton in lakes.
- Whales feed on tiny animals that eat phytoplankton.