What is a lagoon?

A lagoon is marine water or freshwater that is near to, but separated from, a larger body of water by a natural barrier or several natural barriers. It occurs in oceans and near the coast. Some lagoons have brackish water, which is a mixture of sea water and freshwater from a river mouth at the coast.

The natural barrier between the small and large body of water can be a reef or a sandbar.

The word lagoon comes from the Italian word laguna, meaning pond or lake.

There are two types of lagoons. 

One type of lagoon is an atoll which is a ring of land caused by a submerged island. In the centre is the deep-water lagoon. Scientists think that an atoll takes about 300,000 years to form. The atoll lagoon is quite protected from the ocean water.

The other type of lagoon is a coastal lagoon. It is usually shallow water that is separated from coastal sea water. It is usually exposed because it is close to the shore, but it is protected by sandbars. 

Lagoons are also called estuaries, sounds, bays, or lakes.

Many animals like lagoons because they are not far from land. Water birds like lagoons. Fish, sea stars, jellyfish, and many other aquatic animals like lagoons.

Photographer: Martina Nicolls

Martina Nicolls: SIMILAR BUT DIFFERENT IN THE ANIMAL KINGDOM