Original subtitles

[♪]

[Wind whistles]

[David Suzuki]: The end of the last Ice Age

signalled the birth of modern Canada.

But thousands of years later,

much of the north is still buried under ice.

People have shaped and exploited other areas of Canada,

but the ice and cold

have made the far north seem impenetrable.

Few people or animals feel at home here.

Less than 1% of North American mammals

can survive year-round above the tree line.

Ice defines the Arctic,

and what happens to ice here

will influence the entire planet.

Ice suits one creature more than any other in the Arctic...

The Polar bear.

Last fall, this mother built her den in the frozen ground

and gave birth to a pair of cubs over winter.

She hasn't eaten for eight months.

But she's lost almost half her body weight,

and relies on a double-layered coat of fur

to keep warm.

She needs to find food soon.

But she will have to wait

until her cubs are confident enough

to travel long distances.

They have no immediate worries,

as their mother will nurse them for around two years.

So for now, they can explore and play.

The ice that will become their greatest ally

is at first strange and new.

In early spring,

this family will travel hundreds of kilometres

to reach hunting grounds

before the break up of the sea ice.

Polar bears hunt seals in many different ways,

but they all rely on sea ice.

To anyone who hasn't spent their life here,

Arctic ice appears to be a single entity.

In fact, it takes many different forms

both on land and sea,

varying massively in age, consistency, and behaviour.

Some communities in the north

have 70 different words to describe sea ice,

even more than they have for snow.

Ice can be many different things,

from gigantic glaciers

to the smallest crystals,

and some ice behaves in astonishing ways.

With the right conditions,

one of the Arctic's secret ice wonders

starts to grow.

They are called frost flowers,

a phenomenon where beautiful patterns of ice

form on the frozen sea

when temperatures suddenly plummet.

No one knows for sure why they form,

but scientists know

that they contain a high concentration of bacteria,

the building blocks of life.

Only hours after they appear,

their intricate structures start to fade,

leaving no trace behind.

Sea ice is almost always in flux,

and it can move in all sorts of ways.

Seen from the level of the frozen sea,

it looks as if the cliffs are climbing to the sky.

But this illusion is created

by some of the largest tides in the world,

which are still flowing underneath the ice.

When the tide comes back in,

the temporary ice cliffs vanish once again.

This landscape appears to breathe.

These forceful tides present hidden opportunities,

but are also extremely dangerous.

With all other traditional food sources

hard to find in february,

these hunters will take the risk.

They know that at the lowest tides,

the sea under the thick ice retreats so far back

that if you know what to look for,

you can find stable hollow spaces under the ice.

This gives them access

to the rich bounty of the seabed.

It's knowledge that has been passed down

from generation to generation.

They are willing to risk the danger

from tonnes of ice

just centimetres above their heads,

all for an unlikely source of nutritious food...

Thousands of rich mussels,

enough to feed all their families.

They have less than an hour to collect them

before the tide returns.

When the sea starts to come back,

there's no time to lose.

They must leave now before the cave fills with seawater,

trapping them beneath the ice.

In moments, the ice seals over,

and there's no trace of anyone having been there.

[Wind blows]

Like the Inuit,

the animals that live year round in the Arctic

also know how to exploit local conditions

to find hidden food.

Even though the sea freezes over winter,

there are places

where the current and wind keeps the water open.

Called Polynyas, they act like oases,

and are magnets for animals.

In the middle of Hudson Bay,

common Eider ducks are drawn

to one of these patches of open water

to find food.

They appear to fly

as they dive to depths of 15 metres

to forage on the ocean floor.

They are looking for mussels and urchins.

Their digestive juices are so powerful

that they can eat the mussels, shells and all.

They can dive a long way on a single breath,

knowing the way back up only takes seconds.

In the deep winter,

with a wind chill that makes it feel like -70,

the opening in the sea ice is starting to close.

Without open water,

the birds have slim chances of survival.

The stronger birds sense what's happening

and fly off to find new water,

even though they have no idea how far that might be,

or if they'll make it.

But to stay is also risky.

The temperature needs to warm up to keep the water open.

At some indefinable point,

the ducks' options are gone.

Their energy is fading,

and they can't dive to get more food.

Sadly for the ducks,

the march of the ice here is unstoppable.

By april,

the sun is back for a good 12 hours each day,

and the land gradually warms.

The rise in temperatures triggers the spring melt,

a period of frenetic change and activity in the Arctic...

Which is focused at the floe edge,

the boundary between the open water and sea ice.

It's the ice that is the key

to the blooming of life here at this time of year.

Long strands of algae grow,

which feed vast blooms of microscopic plankton,

the food for the explosion of life here each spring.

Under the ice,

there is twice the productivity

that would occur in the open ocean.

Fish, like the Arctic cod...

Seabirds...

And large mammals, like the seal,

are all drawn in.

In a matter of weeks,

this seemingly desolate frozen sea

has become a hotspot for life...

And that means it's the perfect time

for the Arctic's top predator to show up.

It's springtime at the floe edge,

and Polar bears are here to hunt ringed seals.

Seals are most vulnerable when basking on the sea ice,

so they choose open areas

where they can see and smell approaching predators.

The Polar bear goes hungry...

Again.

Nine out of every ten hunts end in failure.

The Polar bear rarely stops looking for food,

and there's plenty around here.

Polar bears are not the only big predators

who have come to the floe edge to find seals.

[Wind whistles and blows]

With harpoon ready,

the Inuit hunter patiently waits perfectly still by a seal hole.

The approach is so similar to the bear's

that it's hard not to suppose

that the Polar bear inspired the Inuit

thousands of years ago.

[Dogs bay and bark]

Today, this seal isn't for the humans.

It's destined for the hunter's pack of dogs

that brought him out to the floe edge.

The meat is so rich and nutritious

that it will keep the dogs fed for days.

Finally, the Polar bear has succeeded in getting a seal.

But he's gone about it in a most unusual way.

He's found the leftovers of the dogs' dinner...

[Dogs whine, bark]

Much to their distress.

[Dogs howl and bark]

He has to build up enough fat reserves

to last throughout the summer,

as hunting will become much harder

when the sea ice melts.

[Dogs barking]

A mother and two yearling cubs

arrive at the foot of cliffs near the floe edge.

She's skinny and desperately needs food.

The thousands of murres

who are starting to nest on narrow cliff ledges

have caught her attention.

The hungry mother heads up the cliff to investigate,

taking one cub with her.

Later in the year,

the bears will feast on murre eggs and chicks,

but right now,

the adult birds are just too hard to reach.

The second cub, still on the ice,

gets lucky when it finds an injured murre.

This makes for a small but much-needed meal.

Up at the top of the cliff,

the mother and cub aren't getting anywhere.

The cub resorts to eating moss.

The lone cub catches up with the rest of the family...

And they are happily reunited.

[♪]

And on snow, what goes up must slide down.

At the bottom, their interest in the murres finally pays off.

The mother is able to feed as well.

She needs to eat

as she is still providing milk for the cubs.

This tight family unit will stay together

until next year,

and then the cubs will head off and fend for themselves.

As spring continues,

the sea ice starts to break up.

Even for the Inuit,

who know this ice better than anyone,

the ice is much more unpredictable now

than in years past.

The dogs can sense the thickness and stability of the ice

through their paws,

and so offer more protection than riding on a snowmobile.

Gradually, the speed of the break-up accelerates.

Life for those who depend on the ice

becomes more precarious.

[Splashing]

With rising temperatures, the fragmentation continues

and creates long passages between ice sheets

called leads.

The magical narwhal,

with its spiralled elongated tooth,

have been waiting for this moment.

With no dorsal fin,

they are perfectly adapted to the Arctic.

They can dive under and between the ice

the moment it begins to break up.

They are heading up long inlets

to find a safe place to raise their calves.

This break-up signals

the start of the short but intense Arctic summer.

Each summer,

the Arctic landscape is transformed.

More than half of all the Arctic sea ice melts.

And now it's disappearing at a faster rate

than anyone could imagine.

We still don't know

how these changes will affect the life here.

Although walrus use ice to rest on,

they also love to bask on rocks in the summer sun.

Walrus are bottom feeders.

They shoot water from their mouths

to excavate clams.

Sensitive bristles

help find them in the muddy seabed,

then they suck them out with their huge rubbery lips.

The summer's heat also triggers a massive change inland,

on the tundra.

As the snow melts,

female caribou migrate hundreds of kilometres

to their calving grounds in the far north.

More than half of all the females

will give birth within a few days of each other.

It's called "predator swamping."

This year, the summer melt has come early,

so the river current is strong.

The soft snow makes it hard

for the pregnant caribou to get out.

But caribou are some of the most resilient animals

on earth.

On one of the longest days of the year,

the mothers start to give birth.

[Caribou snorts]

Within minutes, the newborn calf is up on its feet.

Within hours, he can walk well.

And within days, he can keep up with his mother

over long distances.

Fresh green vegetation grows vigorously

with the 24-hour sunlight,

and gives the mother the energy

to produce rich milk.

Today, across the Arctic,

caribou numbers are falling dramatically.

Their finely tuned body clocks are out of sync

with the variability of the seasons now.

At the height of this most productive time,

they share the tundra with many other species.

But with no trees,

nesting birds are vulnerable

to predators like the Arctic fox.

Canada geese make themselves big and threatening.

But the fox is not actually after the birds.

The fox buries the egg,

knowing that harder times lie ahead.

It can return to the exact spot at any time for a ready meal

when there's less easy prey about.

In the Arctic,

it's all about reaping the rewards

when they are on offer.

It's harder for some Arctic animals

to adapt to their changing world

than others.

As the ice season gets shorter,

Polar bears have less time to hunt.

During the longer, warmer summers,

their metabolism slows right down to conserve energy.

Some bears that didn't catch enough seals

eat seaweed to fill their stomachs.

Others pluck individual berries off thorny bushes...

But these are slim pickings

and provide nowhere near enough calories

for the bears.

What they need is fat and protein,

and that means they must hunt.

A few ingenious bears in Northern Québec

have learned that Arctic char can be found here

at this time of the year.

The fish can't survive in the icy winter ocean,

so they all return inland before it gets too cold.

And this gives the waiting Polar bears

a chance to catch them.

Polar bears hunt best in and around ice.

They need a new strategy here.

And unlike grizzly bears,

this kind of chase doesn't seem to come easy to them.

At last, this bear gets a meal with some protein.

But for the Polar bears that stayed at the coast,

the ice can't return fast enough.

At the height of summer

in the Canadian Arctic,

thousands of beluga whales head to somerset island

for a seasonal get-together.

Like the narwhal,

they're adapted for a life in the Arctic.

They don't have a dorsal fin,

and they have a huge amount of blubber,

up to 50% of their body weight.

But they haven't come here to feed.

They are here for the equivalent of a health spa.

This shallow estuary contains a mix of fresh and sea water

which is warmer than the open ocean.

The water and gravel allow them to have a body scrub,

which helps get rid of their old skin.

They appear to love it.

But beluga can't relax too much.

They face new threats

caused by the changing summer conditions.

[Blowing]

Killer whales have traditionally found it hard

to hunt in the Arctic

because of their massive dorsal fin,

which can be taller than an adult human.

They aren't able to travel far under the sea ice

because of their dorsal fin,

which interferes with their ability

to surface and breathe.

But as more of the sea ice is melting,

they appear to be increasing in number,

coming in from the atlantic

to hunt large marine mammals like beluga and narwhal.

[Blowing]

Many feel they are fast becoming

the Polar region's top new predator.

Although Polar bears can swim vast distances,

hunting in an ice-free ocean is virtually impossible.

We now know that the sea ice will be gone in the summer

within a few decades.

For so long,

the far north of Canada was a stable haven

for the animals that were adapted

to life in the extreme cold.

And it seemed to be a place too vast and too extreme

to be affected dramatically by people.

But that didn't turn out to be the case.

From a distance, and unintentionally,

humans have triggered the massive changes

now underway here.

The future is uncertain in an Arctic landscape

that is undergoing

some of the most intense and rapid fluctuations

in the history of the planet.

Ever since the melting of the continental ice sheet

began 15,000 years ago,

animals and humans alike

have shaped the landscapes of Canada.

And humans continue to play a defining role,

although the speed and scale of our influence

is accelerating.

Canada's unique natural history has created

one of the richest and most beautiful countries on earth...

And one that, at least for now, remains surprisingly wild.

[♪]