Original subtitles

[water rushing]

[ice floes creaking]

[birds cawing]

[gentle, serene music playing]

[Barack Obama] A polar bear.

The top predator in the world's fastest-changing ocean.

[polar bear huffs]

Wanderer of the sea

and its frozen surface.

[sweet, whimsical music playing]

She's got company.

Two hungry little troublemakers.

Her cubs were born on land,

but will spend most of their lives on this frozen ocean.

And it's her job to teach them how to find food.

[mother huffs softly]

Lesson number one is learning to navigate the sea ice.

[whimsical, enchanting music playing]

Not easy, when it's constantly moving.

Her smallest cub is finding sea ice school

a bit of a stretch.

The climate crisis means

the sea ice is thinner and less reliable than when she was a cub.

[water burbling]

[confused huffing]

[somber, distressing music playing]

Her smallest is starting to lag behind.

[whimpers]

So, Mom decides school's over for the day.

It's time to get them back to safety, before they get too wet and tired.

[agitated huffing]

[yawps]

For the little one, it's just too much.

[distressing music continuing]

[little one huffs plaintively]

In this fast-melting ocean, he'll face many obstacles.

[little one yawps]

[distressing music continues]

Being so small, he's vulnerable to hypothermia,

which is one of the reasons why almost half of all polar bear cubs

don't make it to their first birthday.

[whimpers]

Mom must decide.

Does she prioritize her strong cub and keep moving in search of food?

Or, does she let the weakest hold them back?

[whimpering]

[bittersweet music playing]

The cries of her baby

prove impossible to ignore.

[bellows]

[little one yowls]

[gentle, hopeful music rising]

It's been a tough day,

but the little cub has learned an important lesson.

To never give up.

The future of this melting ocean is being written now.

Only those able to adapt will make it

in the fastest-changing of all our oceans.

[sweeping, majestic music playing]

For thousands of years, the Arctic has been a frozen ocean.

Today, our actions are melting this barrier

that once held outsiders back.

As the climate crisis heats the global ocean current,

warmer waters are encroaching from the Atlantic,

creating challenges for some and opportunities for others.

[water burbling]

The great current sweeps past Iceland on its journey north,

where one extraordinary sea creature is thriving

at the very edge of the Arctic Ocean.

[tinkling, eccentric music playing]

The wolffish.

Eating his way north, one urchin at a time.

But in summer, his focus shifts from finding a meal to finding a mate.

He's on the prowl for a she-wolf.

[jazzy lounge music playing]

Could she be the one?

To a wolffish male,

she's gorgeous.

But, sadly, it appears she's settled down.

On to the next.

Inside every wolf den he tries,

the females already have partners.

[music trails off]

[eccentric music playing]

Wolffish teeth aren't just for eating.

A snarl signals aggression.

The lone wolf is no match

for this protective male,

whose battle scars are a sign he's seen off many other rivals.

Instead, he must bide his time...

[eccentric, suspenseful music playing]

...waiting for another daring bachelor to come along.

Bigger, bolder, this new guy is a true match for the scar-faced male.

[music intensifies]

[music trails off]

On the sidelines, the lone wolf waits

for just the right moment,

when both his rivals are exhausted.

Only now does he make his move...

[eccentric music playing]

...sneaking in next to the unattended she-wolf.

Where he seems to seal the deal with a gift.

[jazzy lounge music playing]

But in fact, she's outsmarted them all.

After mating, she ghosts her lover, laying her eggs and promptly dumping him.

Leaving him to raise their offspring for the next seven months,

when, if he's successful,

some of their babies will be swept north on the great current...

[stirring, rousing music playing]

...joining millions of tons of warm water barreling further into the Arctic.

The combination of this warm current and changing climate

is turning once-solid ice into slush.

[music halts abruptly]

[croaky bellowing]

[huffy harrumphing]

Walrus mothers and calves use the biggest chunks they can find

as a floating nursery.

They have one of the closest bonds of any Arctic animal.

[elegant, quirky music playing]

Snuggling up for warmth.

But at three years old,

some youngsters are almost the size of their mom.

[quirky music trails off]

And this calf is no longer the apple of her eye.

He's recently been replaced...

[cheeky, lively music playing]

...by an annoying little brother

who's hogging all her milk and affection.

[blubbering]

[walrus gurgles]

Whenever he tries to get her attention...

[loud baying]

...he's given the cold shoulder.

He has no choice but to leave home.

Females often stay in the nursery their whole lives,

but there comes a time when every male walrus

must leave Mom's side in search of companionship...

and will travel hundreds of miles to find it.

[eccentric woodwinds playing]

Every adolescent needs some buddies their own age.

[zesty, festive music playing]

At last, a gang of mostly young, ousted males...

who've formed a boys-only beach club.

If only they'll let him in.

[splutters]

It's smelly...

[flatulence squeaking]

...boisterous...

[harrumphs]

...and to get in, you have to pass an initiation.

To get the warmest spot in the middle,

he'll need to find a way through this scrum of tusks and blubber.

Room for a little one?

[walruses braying]

Time to create a distraction.

[lows]

[all bellowing]

It doesn't take much to get them going.

He might not be big enough to fight his way in.

But he's still small enough to crowd-surf.

Ah.

Finally, he earns a prime spot...

and discovers these big brutes

are, in fact, big softies...

giving him all the companionship he craves.

It seems male walruses can do well in these beach haul-outs...

but moms and babies may find it harder to adapt to the changing Arctic

as the sea ice they need for their nursery becomes more unstable.

[distressing music playing]

Thanks to the climate crisis,

half of the Arctic summer sea ice has been lost in the last 40 years.

Much of what remains drifts across the ocean

at the mercy of the current, wind, and tides.

[floes creaking ominously]

[sobering, distraught music playing]

Beneath the frozen surface, the great current flows on,

carrying with it seemingly delicate forms of life.

A swimming sea slug.

Also known as a sea angel.

Its translucent body reveals tiny glowing organs.

[shimmering, ethereal music playing]

Drifting nearby...

a comb jelly refracts light into psychedelic colors.

Surprisingly resilient to changing sea temperatures,

new science has revealed that comb jellies are, in fact,

the most ancient lineage of sea creatures alive today.

For over 500 million years,

they have been our ocean's greatest survivors.

But faced with rapid change,

most of the Arctic's residents aren't so resilient.

[wind rushing]

This frozen lake, 500 miles north of the Arctic Circle,

hides a secret.

[mysterious music playing]

Arctic char, imprisoned by the ice.

They've evolved to survive in both fresh and salt water.

Getting the timing right as they move between the two

is a matter of life or death.

It's warmer here than in the Arctic Ocean,

so hundreds of char have overwintered in the lake.

But there's little food to be had.

And after ten months of fasting, they are starving.

The weak and hungry char line up at the wall of ice...

[ice creaking, thumping]

...waiting for temperatures to rise

and the floodgates to their summer feeding grounds to open.

They prepare themselves for a return to salt water.

[bold, steady bass line pulsing]

Until at last...

the river begins to flow...

[dynamic, energetic music playing]

...reconnecting their lake to the ocean.

[music intensifying]

[grumbles]

The char reach the sea.

But in their weakened state, the cold slows them down.

So, for a few days, they're vulnerable.

[gulls cawing]

Gulls sound the dinner bell.

The sushi belt is on the move.

[whimsical, sprightly music playing]

Char are not exactly fast food...

but they're still surprisingly hard to catch.

[grouses]

In an ocean where you must make the most of any opportunity,

it's a chance to feast.

[music trails off]

The char who survive the onslaught venture beyond the river mouth

and into the path of a much larger predator.

[sweeping, magical music playing]

Narwhal, the unicorns of the sea.

Males have a canine tooth up to ten feet long,

with millions of nerve endings inside.

Its many uses are still being discovered.

[lively, enchanting music playing]

With pinpoint precision, this tusker separates a single char.

But he's not trying to spear it.

He's trying to stun it.

And his persistence pays off.

This is the first time a narwhal has been filmed hunting Arctic char using its tusk.

And he's not alone.

Other males are using the same technique.

We don't know yet if all narwhal hunt like this,

or if these are the only ones who have learned

to take advantage of this brief seasonal bounty.

But this windfall may not be around for much longer.

[distressing, eerie music playing]

The climate crisis is now heating some coastal rivers

to over 70 degrees Fahrenheit.

A threshold beyond which Arctic char cannot survive.

This delicate web of life is at risk.

And we may lose this Arctic spectacle

before we've even had a chance to fully understand it.

[sweeping, majestic music playing]

Nowhere is the warming ocean current having a bigger impact

than around a group of islands in the high Arctic.

Svalbard.

Svalbard's climate is warming six times faster than the global average.

This changing landscape creates a challenge for a hungry polar bear...

who, instead of stalking the ice, must swim to find his next meal.

[quizzical music playing]

A bearded seal.

The biggest and fattest seal in the Arctic.

The perfect target.

Bears and seals have played a cat-and-mouse game on the sea ice

for generations.

But as the ice melts,

the rules are changing.

[music intensifies]

[eccentric musical flourish]

[birds squawking]

He's trying to master

the art of sneaking up on your prey from the water.

To succeed, he'll need a stealthier approach.

[quizzical music continuing]

Nothing to see here.

But he can't resist a peek.

And now, the stalked becomes the stalker.

[plucky, eccentric music playing]

He's behind you.

The seal is showing his attacker that he's blown it.

Time to move on.

[music trailing off]

[somber, taut music playing]

His skills are being tested.

This time, there is over 600 feet of open water between them,

and nowhere to hide.

[suspenseful music intensifying]

To disguise himself here,

he must become invisible.

[music intensifies]

[jolting stinger]

[relieved sigh]

[plucky, eccentric music playing]

It's just not his day.

If polar bears are going to succeed in this new, warmer world,

they'll have to perfect this hunting strategy.

[somber, thoughtful music playing]

Dwindling sea ice might be tough on ice specialists,

but the seasonal summer melt is just what visiting seabirds need

to access the Arctic's riches.

Brünnich's guillemots.

The penguins of the north.

As proficient in the water as they are in the skies.

[sparkling, lively music playing]

Their small but powerful wings allow them to dive 650 feet,

deeper than any other flying bird.

On the 500-foot cliffs above their feeding grounds,

this little seabird

has yet to wet her wings.

[chirrups]

She lives in one of the biggest guillemot colonies here.

[overwhelming din]

A squawking city of over 100,000 residents.

But not all of them get the same start in life.

She was born at the top of this tower block.

[warm, gentle music playing]

It might seem like a dangerous place to raise a family,

but hers is a life of luxury.

Tucked under Dad's down duvet, she's hidden from predators.

Mom delivers food daily, straight to her penthouse...

[mother squawks]

...which has en suite facilities.

Below them, the neighbors are forced to live in squalor.

So far, this privileged chick

has never had to venture beyond the comfort of her ledge.

But at three weeks old,

the time has come for her to spread her wings.

She must join the adults out at sea,

since food near the colony is running low.

[tense music playing]

Getting down will be the biggest challenge of her little life.

She can't fly yet...

and the only way to reach the water is to jump.

[cawing]

[foreboding music intensifies]

If she misses the ocean,

even by a few feet,

she'll hit the rocks below.

Beneath her, other chicks are preparing to jump.

[squawks]

[tense music escalating]

The further the BASE jump, the harder it seems.

Adults jump with chicks for support.

[music swells]

[thud]

[bleak music playing]

[fox growling]

Arctic foxes wait for casualties.

At the top of the colony,

the little chick faces the scariest jump of all.

[bleak music continuing]

[squawks]

Dad jumps with her.

[music intensifies]

[muffled thud]

Her feathers cushion the impact just enough.

But making it to the ocean does not guarantee safety.

[grim, foreboding music playing]

A Glaucous gull...

on the lookout for stragglers.

[taut, intense music playing]

[gull cawing]

The gulls squabble...

[squawks]

...giving time for reinforcements to arrive.

[triumphant, uplifting music playing]

It's not just family who come to the rescue.

Neighbors from high and low pile in too.

Because no matter which ledge they're born on...

they're all in it together.

[music trails off]

The great current continues its journey around the Arctic Ocean,

where some of the outbound current

peels off through the Canadian archipelago.

The Northwest Passage.

[daunting, intense music playing]

A fabled sea route...

notoriously clogged by ice.

Wind and current fracture and pile up the ice,

creating frozen pinnacles

up to 60 feet thick.

[ice creaking ponderously]

Making it impenetrable to most ships.

But one Arctic resident has their own way of navigating this ice-clogged waterway.

[delicate, inquisitive music playing]

A beluga whale and her baby...

[echolocation trilling]

...on a long voyage to a secret spot.

These white whales are known as the canaries of the sea.

They use a complex language,

helping calves to stay in close contact with their mothers

as they learn to navigate the ice maze.

[echolocation trilling, clicking]

These ice-savvy whales can swim through cracks in the sea ice.

Most would struggle to travel here.

But belugas have no dorsal fin,

an adaptation which allows them to slide just under the ice.

The calves can hold their breath for over eight minutes,

sipping breaths through ice holes as they go.

[gentle, inquisitive music continuing]

At last, the whole family makes it through,

arriving at an almost ice-free coast.

This inlet is what they've traveled hundreds of miles to find.

The adults have been coming here since they were calves.

And today, the newest members of the pod are learning why it's so special.

[quirky music playing]

They follow their parents into just six feet of water.

In summer, melting rivers feed the inlet,

making it a balmy 20 degrees Fahrenheit warmer than the ocean.

[folksy, whimsical music playing]

It's a beluga health spa.

And the youngsters are checking out the facilities for the first time.

Dad goes for a body scrub,

while the aunties try some aqua aerobics.

And, if you know where to look,

there are special tricks for scrubbing those hard-to-reach places.

Mom shows her baby beluga

how to use the larger rocks like a body loofah.

Just what she needs after months at sea.

But the family doesn't have exclusive use of this wellness retreat.

[jaunty cabana music playing]

Other beluga pods arrive.

They're all here to exfoliate their dead, yellowing skin

and shed parasites.

They scrub until it's gleaming white.

Even the babies learn the importance of self-care.

At peak times, up to 2,000 gather here to enjoy the inlet's health benefits,

creating one of the liveliest beluga pool parties on Earth.

[joyful whale song]

Their pleasure is audible,

and can be heard below the water for miles around.

But beluga voices are being drowned out by a new threat.

[low, pervasive rumbling]

[loud cracking]

Noise pollution.

[ship's horn blares]

The Arctic Ocean is changing from a quiet, icy haven

to a busy shipping highway.

Five times as many vessels are now cutting through the Northwest Passage

than they were two decades ago.

Increased traffic is bad news for belugas...

[burst of echolocation]

...who rely heavily on their world of sound.

And they're slow to adapt to change.

Their ancient migration paths are now in direct conflict

with the new shipping routes...

[foreboding music playing]

...increasing chances of ship strikes.

Across the Arctic, nations are racing

to stake their claim to this final frontier,

with new industrial exploration happening every year to meet the world's demands.

[foreboding music continuing]

Some of the world's most valuable untapped resources

are thought to lie in the Arctic deep.

[mysterious music playing]

Technology, like this remotely operated vehicle...

is allowing us to explore previously uncharted depths.

Close to the North Pole, two-and-a-half miles beneath the sea ice,

there's a primal source of heat.

A deep-sea volcano.

The furthest north ever found.

Its vents are gilded in precious metals.

It's estimated that millions of tons of minerals,

and 90 billion barrels of oil,

lie in the Arctic deep.

[volcanic vent rumbling]

As this melting ocean becomes easier to access,

mineral extraction,

and even deep-sea fishing,

are becoming possible.

[mysterious, fraught music playing]

The Arctic's deep-sea treasures are still being discovered.

But they're already in great peril.

Now, we have a choice.

To exploit or protect these incredible new discoveries.

[polar bear whuffs]

[sweeping, mysterious music playing]

In just over three years,

the global ocean current

completes its journey through the Arctic Ocean,

coming full circle.

In early summer,

the shores of northeastern Svalbard would normally be covered in sea ice.

But the climate crisis has turned ice into open water.

This mom is taking her one-year-old cubs beachcombing.

Foraging has always been part of the bears' skill set.

But without sea ice to hunt on, they must now increasingly rely on it.

[delicate, uneasy music playing]

When she was their age,

she would only have had to endure up to two summer months without ice.

Now, it can be twice that or more.

Meaning long periods of famine.

So, she must teach her cubs how to be resourceful,

searching for scraps.

[somber, distressed music playing]

Working out what's safe to eat

and what isn't.

It's confusing, even for an adult.

The current carries plastics and pollutants to the Arctic

from neighboring oceans.

Getting tangled in the shoreline litter can be a death sentence.

[whimpering]

But not this time.

[melancholy, somber music playing]

Other threats are inescapable.

Like chemicals from industrial pollution.

In polar bears, these chemicals accumulate

and can affect their ability to reproduce.

In the face of adversity,

this mom and the rest of the Arctic's residents

are doing their best to survive.

[forceful, dramatic music playing]

The Arctic Ocean is no longer the icy stronghold it once was.

Hordes of new arrivals are following the retreating ice north.

Orca.

And humpback whales.

Creating opportunities for themselves

and competition for residents.

And, among them...

a blue whale.

[deep, resonant lowing]

The biggest animal

to have ever lived on Earth.

Nearly 100 feet long

and weighing over 150 tons.

[dramatic music continuing]

She has made this long-distance voyage

following krill that are flourishing in the warming current.

And she's not alone.

It's the first time Atlantic blue whales have been filmed

bringing their calves this far north,

signaling huge changes that are already happening.

In the global climate crisis,

every Arctic resident is on the front line.

Their survival in this precious but fast-melting ocean

is in our hands.

Next, we voyage all the way to the Southern Ocean.

[majestic, stirring music playing]

Isolated,

mysterious,

and bountiful.

The great current brings new challenges,

and only those tough enough...

will survive.

[growls, snarls]

[whimsical, delicate outro music playing]