Plankton are tiny organisms that drift in water and cannot swim strongly enough to move against currents. They include both phytoplankton (plant- like, photosynthetic) and zooplankton (animal-like), and they form a crucial part of aquatic food webs.

Quick Scoop

  • The word “plankton” comes from a Greek word meaning “drifter” or “wanderer.”
  • Plankton can be microscopic, but some larger organisms like jellyfish can also count as plankton if they drift with currents.
  • Phytoplankton make their own food using sunlight and help produce oxygen.
  • Zooplankton eat other organisms and are an important food source for many sea animals.

Simple example

Think of plankton like the ocean’s tiny floaters: some are like drifting plants, others like drifting animals, and many bigger creatures depend on them for food.

Why it matters

Plankton are a foundation of the ocean food web, supporting everything from small fish to whales. They also play a major role in the planet’s oxygen production and carbon cycle.

TL;DR: Plankton are tiny drifting organisms in water, and they are essential to ocean life.