What is Plankton?

Plankton is made up of animals and plants that either float passively in the water, or possess such limited powers of swimming that they are carried from place to place by the currents.

Plankton is made up of animals and plants that either float passively in the water, or possess such limited powers of swimming that they are carried from place to place by the currents.

The word plankton comes from the Greek word planktos, which means ‘wandering’ or ‘drifting’. Plankton dominates the well-lit surface layers of the world's oceans.

Plankton range in size from tiny microbes, which are invisible to the naked eye, to jellyfish metres long. Apart from bacteria, planktonic organisms are the most abundant life form on earth and play a crucial role in the marine food chain. Without plankton, there would be few living organisms on earth, and certainly no Great Barrier Reef. Planktonic organisms are food for a range of animals from barnacles and sea squirts to large fish and whales. The largest fish in the world, the Whale Shark, is a plankton feeder as are many of the largest whales.