Blue Planet II explores parts of the ocean that nobody has ever visited, encountered extraordinary animals, and discovered new insights into life beneath the waves. In Our Blue Planet, Sir David Attenborough examines the impact of human life on life in the ocean. In this final episode, we uncover the impact that our modern lives are having on our best-loved characters from across the series, including devoted albatross parents unwittingly feeding their chicks discarded plastic and mother dolphins potentially exposing their new born calves to pollutants through their contaminated milk. Scientists have even discovered that increasing noise levels may stop baby clownfish finding their way home.

The big blue is the world's greatest wilderness, far from shore and many kilometres deep. It's a vast marine desert where there is little to eat and nowhere to hide. Yet it's home to some of the biggest and most spectacular creatures on earth. This episode reveals what it takes to survive in this savage and forbidding world. We witness feats of incredible endurance, moments of high drama and extraordinary acts of heart-wrenching self-sacrifice. Every animal in the big blue must find their own unique way to survive. Sperm whales have the largest brains in the world. They live for 80 years, and we are only now beginning to learn the extraordinary complexity of their language of clicks - thought to coordinate the whole family in everything from childcare to hunting. With special pressure-proof cameras, we witness record-breaking feats of endurance as they hunt for squid a kilometre down into the abyss. Only recently have we begun to solve the mystery of where baby turtles disappear to in their early years. They leave the crowded waters of the coast and head to the open ocean, where they use floating debris like logs as life rafts. Here they remain until adulthood, adrift on the high seas in relative safety away from coastal predators. Over half of all animals in the open ocean drift in currents. Jellyfish cross entire oceans feeding on whatever happens to tangle with their tentacles. The jelly-like Portuguese man-of-war can harness sail power to fish with its deadly tentacles. Sometimes there is a brief explosion of food in this marine desert, but ocean hunters must be fast to make the best of this bonanza. We witness super pods of up to 5,000 spinner dolphins racing to herd vast shoals of lanternfish, briefly caught at the surface where it is thought they spawn. New aerial footage reveals, for the first time, the truth to a centuries-old sailors' legend of the 'boiling seas' - the spectacular feeding frenzy of 90kg tuna and dolphins smashing through the lantern fish shoals turning the sea white with foam.

Nearly a generation after the acclaimed Blue Planet documentary was released, David Attenborough returns to narrate this groundbreaking sequel/reboot. Blue Planet II focuses more heavily on mankind's influence on the world's oceans through both global pollution and climate change. This series features a variety of revolutionary segments never before seen in a video documentary. One Ocean Footage of marine life in different environments around the north, beginning with a tropical coral reef which has medicinal properties for dolphins, and is used as a tool by tusk fish. In Japan, a shipwreck is home to the Asian sheepshead wrasse, which can change gender, while in the polar north, walruses struggle to find ice floes for their pups to rest on as climate change takes its toll on the environment.

Scientists around the world are asking themselves the same questions. Over the decades the focus on dolphin research has changed from asking 'how intelligent are dolphins?' to 'how are dolphins intelligent?' and we look at research from the world's foremost dolphin experts for the answers.

Do dolphins think the way we do or are their brains wired in a very different way from ours? Will we communicate with them one day? Dolphins have been a source of curiosity to humans and have appeared in our stories and myths for thousands of years. What is the link between our two species? Why do we seem to be so interested and curious about each other?

Fly over Africa on the back of a vulture and see the most animal-packed continent with fresh eyes. Arrow-dive with cape gannets among sharks, dolphins and whales as they join the great sardine run. Soar with fish eagles as they discover an S-shaped living island comprised entirely of flamingos, and join them on a spectacular hunt. Fly with kelp gulls as they study the hunting behaviour of the greatest underwater predator of all: the great white shark. On the wings of eagles, fly through the mist-filled Victoria Falls and dive for fish in the mighty Zambezi. Circle with vultures high above the Serengeti as they watch the drama of the wildebeest migration below, and discover what happens when this canny scavenger suddenly becomes prey. Among toxic soda lakes, find out what it is like to be a flamingo, vulnerable to every predator on the continent, including baboons and hyenas. Join these flamingos as they take part in one of the most beautiful dances in the bird world. This is Africa as never seen before - from the wings of birds