Plankton are many tiny organisms that drift at or near the surface of oceans, seas, lakes, and rivers. The word plankton actually means wandering. It is the source of life for all marine organisms. They do have the ability to swim, but due to strong currents they just float where the water takes them. These plankton are very microscopic. There are two main types of plankton. These kinds are phytoplankton and zooplankton. Phytoplankton consist of one-celled algae and the zooplankton consist of water fleas and jellyfish.
Ocean life begins with these tiny organisms. They are photosythetic animals. By photosynthesizing energy from the sun, they are the source of all the energy that flows to other parts of the trophic levels. They are the basis of this pyramid. Small fish and other animal larvae are considered plankton. Some plankton stay this small all of their lives, while others grow into larger organisms.
