Our blue planet is facing one its biggest threats in human history. Trillions of pieces of plastic are choking the very lifeblood of our earth, and every marine animal, from the smallest plankton to the largest mammals, is being affected. But can we turn back this growing plastic tide before it is too late? Wildlife biologist Liz Bonnin visits scientists working at the cutting edge of plastics research. She works with some of the world's leading marine biologists and campaigners to discover the true dangers of plastic in our oceans and what it means for the future of all life on our planet, including us.
Liz travels to a remote island off the coast of Australia that is the nesting site for a population of seabirds called flesh-footed shearwaters. Newly hatched chicks are unable to regurgitate effectively, so they are filling up on deadly plastic. She visits the Coral Triangle that stretches from Papua New Guinea to the Solomon Islands to find out more from top coral scientists trying to work out why plastic is so lethal to the reefs, fragile ecosystems that contain 25 per cent of all marine life.

Marine invertebrates are some of the most bizarre and beautiful animals on the planet, and thrive in the toughest parts of the oceans. Divers swim into a shoal of predatory Humboldt squid as they emerge from the ocean depths to hunt in packs. When cuttlefish gather to mate, their bodies flash in stroboscopic colours. Time-lapse photography reveals thousands of starfish gathering under the Arctic ice to devour a seal carcass. A giant octopus commits suicide for her young. A camera follows her into a cave which she walls up, then she protects her eggs until she starves. The greatest living structures on earth, coral reefs, are created by tiny animals in some of the world's most inhospitable waters.

There is no greater test for life than winter, as temperatures plummet to 70 below and winds reach 200kph. Darkness and ice extend across the polar regions and only a few remarkable survivors gamble on remaining. We join a female polar bear trekking into the Arctic mountains to give birth as the first blizzards arrive. Out on the frozen ocean, the entire world's population of spectacled eider ducks brave the winter in a giant ice hole kept open by ferocious currents. Arctic forests transform into a wonderland of frost and snow - the scene of a desperate and bloody battle between wolf and bison, but also where a remarkable alliance between raven and wolverine is made. Beneath the snow lies a magical world of winter survivors. Here tiny voles dodge the clutches of the great grey owl, but cannot escape the ultimate under-show predator - the least weasel. Midwinter and a male polar bear wanders alone across the dark, empty icescape. Below the snow, polar bear cubs begin life in an icy den while fantastical auroras light the night skies above. In Antarctica, we join male emperor penguins in their darkest hour, battling to protect precious eggs from fierce polar storms. Weddell seals escape to a hidden world of jewel-coloured corals and alien-looking creatures but frozen devastation follows as sinister ice stalactites reach down with deadly effect.

Coral reefs are the nursery for all life in the oceans, a remarkable ecosystem that sustains us. Yet with carbon emissions warming the seas, a phenomenon called 'coral bleaching' -a sign of mass coral death- has been accelerating around the world, and the public has no idea of the scale or implication of the catastrophe silently raging underwater.
Chasing Coral taps into the collective will and wisdom of an ad man, a self-proclaimed coral nerd, top-notch camera designers, and renowned marine biologists as they invent the first time-lapse camera to record bleaching events as they happen. Unfortunately, the effort is anything but simple, and the team doggedly battles technical malfunctions and the force of nature in pursuit of their golden fleece: documenting the indisputable and tragic transformation below the waves. With its breathtaking photography, nail-biting suspense, and startling emotion, Chasing Coral is a dramatic revelation that won't have audiences sitting idle for long.

Laurent Ballesta has yet again challenged himself to a new world record: spend 28 days at a depth of 100 meters to reveal the luxuriant and unknown depths of the Mediterranean.
Because people have been travelling there for thousands of years, this sea is be­lieved to be without secrets. And yet, far below its surface, lie vast unexplored territories, luxurious gardens worthy of the finest tro­pical coral reefs. These natural wonders are inaccessible to the traditional diver, in a twilight zone, between 60 and 120 m, where there’s less than 1% of sunlight. If diving at such depths is always a challenge, staying there is a fan­tasy, a utopia that becomes reality in 'The Deep Med'.

Corals build themselves homes of limestone in the warm, clear, shallow seas of the tropics. Their reefs occupy less than one tenth of one per cent of the ocean floor, yet they are home to a quarter of all known marine species. The broad-club cuttlefish has found its place by using a hypnotic display that apparently mesmerizes its prey, causing it to let down its defences. On the Great Barrier Reef a remarkable grouper uses sign language, dubbed the headstand signal, to reach out to an entirely different creature, a reef octopus, to flush small fish out of their hiding holes and into the groupers waiting mouth.