The five oceans

On the world map we can see five oceans: the Pacific, the Atlantic, the Indian, the Southern (or Antarctic) and the Arctic. An easy way to remember them is the word PAISA: Pacific, Atlantic, Indian, Southern, Arctic.

PAISA also gives you their order of size, from biggest to smallest. The Pacific is the largest, then the Atlantic. The Indian Ocean is third, the Southern Ocean fourth, and the Arctic is the smallest.

But although we list five oceans, the map shows they are not really separate. The lines dividing them are only conventions (agreements people have made); nature does not follow them. Sea water keeps flowing from one ocean into another, and many plants and animals live across several oceans. A whale does not stop at a line on a map.

Three useful words:

• Marine: to do with the oceans and seas, or found in them.
• Flora: the plant life of a region or a period of time.
• Fauna: the animal life of a region or a period of time.

The marine flora includes tiny plants called algae and all kinds of seaweeds. The marine fauna includes thousands of kinds of colourful fish, dolphins, whales and countless mysterious deep-sea creatures. Every part of the ocean, from the sunlit surface to the dark depths, has its own life.

Our own ocean: the Indian Ocean is bounded by Asia to the north, Africa to the west and Australia to the east, with the Southern Ocean to the south. On either side of India are two parts of it: the Arabian Sea to the west and the Bay of Bengal to the east.