Blue Planet II

New worlds and extraordinary animal behaviours are revealed in this journey from the intense heat of the tropics to the planet's frozen poles. The journey begins in the tropical coral reefs, the ocean's most diverse habitat.

Perhaps the most hostile environment on earth, the deep is a world of crushing pressure, brutal cold, and utter darkness. It is the largest living space on the planet, yet exploration has barely begun.

Coral reefs are home to one-quarter of all marine life and survival can be a tricky challenge. Here, an inventive turtle figures out how to skip undersea queues, and a grouper and an octopus collaborate to expose their prey.

The Big Blue is a marine desert, a vast expanse of empty ocean with scarce food that is home to some of the largest animals on Earth. With the help of pressure-proof cameras, sperm whales are spotted hunting for squid 3000 feet below the surface.

Life comes to the oceans through the green of the sea, where sunlight powers the growth of sea grass, mangroves and kelp. An octopus outwits deadly sharks and cuttlefish battle for a mate in waters teeming with life.

Coasts are an ever-changing landscape where worlds collide, and alongside great rewards is great danger. The creatures that exist here must find ingenious ways to survive.