Blue Planet

The ocean's influence dominates the world's weather systems and supports an enormous range of life. This first episode demonstrates the sheer scale, power and complexity of the "Blue Planet".

The deep sea covers most of the planet and is thus by far the largest habitat on earth, yet has been explored less then space. David Attenborough looks at the strange creatures that live here.

Endless blue stretches in every direction. The sea bed is a staggering eight kilometres deeper down and the nearest island is 500 kilometres away. There is nothing save the burning sun above and the blackened abyss below. How, then, does life exist?

Life on the edge of a frozen sea is tough. Ice at both poles is constantly moving, and in winter freezes solid with air temperatures 70C below freezing. Only in spring, with the retreating ice and light reaching the water, does life begin again.

Shafts of sunlight are the vital source of energy used by the countless billions of plankton that grow every spring and summer in the world's temperate sea, the richest of all habitats.

Coral reefs are the rainforests of the sea; fish compete for food, territory and mates within this oasis of life. Incredible time-lapse photography shows the dramatic formation of a coral reef, portraying its inhabitants and its ultimate destruction.