All language subtitles for The.Blue.Planet.S01E04.Frozen.Seas.1080p.AMZN.WEB-DL.DD+2.0.H.264-playWEB_track3_[eng]

The frozen seas
are worlds unto themselves.

Beneath their ceiling of ice,

they have an eerie,
almost magical stillness,

cut off from the storms
that rage above.

In the winter, the feeble,
slanting rays of the sun

bring little warmth,

and the temperature seldom rises

above minus-50 degrees
centigrade.

For much of the year, it is dark
and cripplingly cold.

Yet there is life here
at both ends of the Earth--

the Arctic and the Antarctic.

For most animals,

whether they live
in or out of water,

the winters,
when much of the sea is frozen,

bring the greatest challenge.

The Northern Hemisphere.

It's February, and as the Earth
tilts on its axis,

the sun's rays
creep slowly northwards

and the Arctic emerges
from its harsh winter.

The Arctic is a frozen ocean
surrounded by continents,

and when the surface of the sea

between the continents
freezes from shore to shore,

land predators
walk out onto it to hunt.

It's early March,

and the sea
is still covered with ice.

But there are patches
of open water, polynyas,

that never freeze over.

Here, where tidal currents
are squeezed between islands,

the water movement is so strong
that ice cannot form.

Walruses spend the winter
in polynyas.

Here they have permanent access
to the air,

but they can also retreat
to the sea

to shelter and to hunt.

Other sea mammals overwinter
in polynyas, as well.

In this one,
a young bowhead whale.

Here the current is really fast,

and the shifting ice
is dangerous.

This whale became trapped

when ice encircled it
last autumn.

There is no food here,
but a whale must breathe,

and the only place that
it can do so for miles around

is in this tiny hole.

It's living entirely
on its reserves of fat,

but now they're dangerously low.

It will be some months yet
before it can escape.

Elsewhere, other whales
have also been trapped.

These are belugas.

Their tiny hole in the ice

has been kept open
not by currents,

but by the belugas'
continuous movements

as they rise to breathe.

Open water is now
some 20 miles away.

It will be two months yet
before the ice melts.

The belugas are extremely thin,

and most of them
are horribly scarred.

But their wounds were not
inflicted by the ice.

A whale would be a huge prize
for any meat-eating hunter,

and these belugas,
trapped by the ice,

are within reach of polar bears.

Well aware of the danger,

the belugas stay submerged
as long as they can,

but they can only hold their
breath for about 20 minutes.

Catching a 4-meter-long whale
that weighs one ton

is no easy task,

even if that whale
is weakened by starvation.

But a beluga
is well worth waiting for.

Day by day,
as the hole gets bigger,

it becomes
increasingly difficult

for the bear to land a whale.

Keeping its fur in good
condition and free from salt

is important for warmth,

and the bear uses snow
like blotting paper.

These belugas have been
attacked by many bears

over the last six months,

and some have been caught.

It may have taken a long time
and a lot of patience,

but a catch, when it's made,

brings abundant rewards
of energy-rich blubber.

Gulls rely on bear kills
at this time of the year,

and the color of blood
staining the ice

attracts them
from a long way away.

The remaining belugas
still have a long wait

before they're released
from their prison

and the threat of slaughter.

Can you feel it?

You're exactly where
you're meant to be right now.

You and me,
we could do anything.

Us against the world.

Welcome to the Theatre
des Vampires.

You have no idea
what I'm capable of.

My word means something.

We need you...

...to lead
the revival of humanity.

You deserve
a happy ending.

Well, guess this is it, then.

Arctic foxes also rely
on the polar bears

to hunt on their behalf.

They're the jackals of the north

and scavenge from bear kills
whenever they can.

In winter and early spring,

they are wholly dependent
on bears.

Only in the summer,
when the sea ice melts,

will they regularly catch prey
for themselves.

They're not strong enough
to tackle adult seals

but can certainly take
newborn pups or birds.

This canny individual
is going to bury its prize.

It may need it during
the uncertain times ahead.

The presence of bears
affects the behavior

of almost all the animals here,
big and small.

The bears tend to avoid

the fringe of fragmented ice
bordering open water,

where traveling
can be very laborious,

but that very fact makes
this area, the pack ice,

a particularly good place
for seals to pup.

Harp seals breed here.

Their pups are born
with white coats,

which camouflage them very
effectively against the snow.

Harp seals have
a very short nursing period,

a necessity on this
unstable pack ice,

but suckling is intensive.

The pup feeds for just 12 days

on milk that is 45% fat.

Then it's abandoned
and has to fend for itself.

A male hooded seal.

This impressive nasal display

is used to warn away
other males...

...and to win a mate.

Hooded seals also breed
on pack ice.

Their pups suckle
for only four days,

the shortest nursing period
known for any mammal,

and all because
the threat of polar bears

cause them to breed
on the unstable ice.

Another Arctic seal opts for
the solid ice further north.

Because it's easy for bears
to hunt here,

these ringed seals
must be particularly vigilant

and have to hide their pups.

Ringed seals
are comparatively small,

so they can give birth
to their pups

in little caves or lairs
under the snow.

Here a pup is out of sight
and protected from bad weather.

In late March and into April,

female bears emerge from
winter dens with their new cubs.

The mother has not eaten
for at least five months,

and she's hungry-- very hungry.

If she doesn't succeed
in catching

a regular supply of seals,

her milk will fail...
and her cub will die.

Bears have an extraordinarily
sensitive sense of smell

and can detect seal pups
hidden in the snow

from 2 kilometers away.

But a female ringed seal
uses several lairs,

and a bear will almost certainly
have to break into a number

before it finds one
that is occupied.

This is a crucial time
for the cub.

By watching its mother hunt
and by copying her actions,

it's beginning to acquire

the rudiments
of its own hunting skills.

Play is also important
for developing muscles

and improving coordination.

As the days ays go by,
the sun rises higher and
remains above the horizon
even at night.

The female bear
continues to hunt

until her cub is too tired
and can't keep up.

She's smelt something.

The pup escapes
through a hole in its lair

that leads to the sea below.

Only one in 20 hunts
is successful,

but this mother
must find a seal pup soon

if her cub is not
to starve to death.

As spring turns into summer,

the sun's heat
begins to melt the sea ice.

Now the ocean is accessible

and the Arctic's
summer visitors return.

Migrating birds
arrive from the south

to nest and feed on the seafood
that's now within their reach.

Brunnich's guillemots

are the northern equivalent
of penguins,

but they have retained
the power of flight,

for they need to reach
cliff ledges,

where their nests will be safe
from predatory bears and foxes.

Nonetheless, they are as at home
in the water as in the air.

They dive down to a depth
of 50 meters or more

to catch fish.

In June,
the ice begins to fracture.

The cracks, or leads,
form useful corridors

of open water
for air-breathing animals.

Belugas, migrating
to their feeding grounds,

use these leads to penetrate
the ice-covered seas

and reach areas where their
preferred food, Arctic cod,

has spent the winter.

The males regularly dive to
about 500 meters to find fish.

The females and young,
which have smaller lungs,

only go to about 350.

In late June and July,
narwhals arrive.

The females,
who usually lack tusks,

come first
with their new calves.

The males follow a little later.

They also move up the leads

in search
of fresh feeding grounds.

Bowheads.

Up to 18 meters long
and weighing 100 tons,

these are the only large whales

that stay in the Arctic
all year round.

They're not after fish.

They're seeking smaller prey.

Despite having the largest
mouths in the animal kingdom--

the size of a small garage--

they eat tiny crustaceans,
copepods,

straining them from the water

with the 4-meter-long
strips of baleen

that hang from their upper jaws.

In the summer,
they store enough energy

to last them through
the following winter,

when food will be less abundant.

As the ice melts away,

the polar bears are forced
to head for land.

They're excellent swimmers

and can cover 100 miles
of continuous open water

if need be.

Off East Greenland,

there is little ice left
by August,

so walruses haul out
to rest on land.

At this time of the year,
they are molting,

getting rid of
their old, scarred,

and parasite-ridden skin.

A bathe in the cold water

brings some relief
from the itching.

But even there,
the odd scratch is irresistible.

They make daily excursions
out to deeper water.

Down at 20 meters, they
root around in the sediment

using their bristles to
search out soft-shelled clams.

Once they find a clam,

they suck its flesh
from the shell

with their powerful,
muscular mouths.

Walruses can feed for about
five minutes at this depth

before they have to return
to the surface to breathe.

Elsewhere in the Arctic,

belugas are gathering
in their thousands.

They congregate in just
a few large estuaries.

Belugas of all ages and sizes
come here.

There are even young calves.

Some are so young--
born only a week or so ago--

that they need help.

They swim
on their mothers' backs

so that they can breathe
more easily.

As the tide
moves up the estuary,

the belugas follow,

swimming into surprisingly
shallow water.

Like walruses,
they also need to molt.

A combination
of warm freshwater

and vigorous rubbing against
the gravel does the trick.

They remain here
for days or even weeks,

so it's likely that socializing

is also important to them.

After molting, they head
back out to sea to feed.

It's now autumn,
and the sea

begins to freeze
over once again.

Thin sheets of ice
form at the surface

and pile up, layer upon layer,

gradually creating
an impenetrable barrier.

By late November,

the Arctic Ocean is sealed
once again by ice.

The lights of the aurora
play in the winter sky.

And at the other end
of the planet,

in the Antarctic,
there is the southern aurora.

Antarctica is now emerging
from winter.

This is the coldest,
windiest place in the world.

Temperatures are still hovering
at a numbing minus-50,

and the returning sun
has virtually no warmth.

Very few animals can survive
such extreme conditions.

But emperor penguins can.

Standing on the frozen sea,

they endure the full force
of the Antarctic storms.

Only by huddling together

can they survive
the appalling winter months.

They take it in turns
to bear the brunt of the gales.

They can only live here at all

because Antarctica is surrounded
by the Great Southern Ocean,

and no land predators
have been able to reach it,

so, unlike Arctic animals,

they're not threatened
by polar bears.

The sea is still frozen,
but one seal,

nonetheless,
manages to stay here,

even throughout the winter.

The Weddell seal.

Underwater, it's protected
from the storms above,

but it must have access
to the air all year

in order to breathe.

And they keep
their breathing holes open

with their teeth.

Only by continually
scraping away at the ice

can they maintain access
to the air,

but that means that their teeth
get badly worn down.

Then they can no longer hunt
and eat effectively.

Weddell seals die young.

The continent of Antarctica
is so isolated and so high--

almost 5,000 meters in places--

that it's considerably colder
than the Arctic.

Ice slides slowly down
from its center

towards its rim
in immense glaciers.

During winter,

the continent effectively
doubles in size

as the sea freezes over.

Ice forms around its shores

and extends outwards
for hundreds of miles

around the entire land mass.

Under the sea ice live small,
shrimp-like creatures--

krill.

They have been here all winter.

During these dark months,

they feed by scraping algae
from the ice.

Remarkably,
they also shrink in size

and revert to their juvenile
form to save energy.

As the temperature rises
in spring,

the ice begins to melt,

and little air bubbles
trapped within it are released.

Microscopic algae
grow around these bubbles,

and the krill now graze on them,

gathering them up
with their beating legs.

As the sun's rays grow stronger

and penetrate deeper
into the water,

floating algae
begin to flourish,

and krill leave
the dwindling ice

and gather in swarms
as they harvest this new crop.

Far to the north,
beyond the blanket of sea ice,

chinstrap penguins
have been overwintering

in the open ocean.

The occasional iceberg gives
them the chance of a rest,

if they can get onto it.

But at this time of year,

where they really want to be
is on land.

It's just getting there
that's tricky.

It's spring, and the penguins
are returning to breed.

Their need to get ashore
is now urgent and imperative.

Doing so
is all a matter of timing

and picking the right wave.

But their journey
has only just begun.

Most of them will
have to walk many miles

before they can find
a nest site.

This is Zavodovski Island,

which has the largest
penguin colony in the world.

About two million chinstraps
breed here,

and they come to this island
for a good reason.

It's an active volcano.

The heat from the crater
and the fumaroles

keeps the slopes
free from the ice and snow,

allowing these chinstraps
to start breeding earlier

than those further south.

But then again,
living on an active volcano

is not without its risks.

Unlike the emperors,

these penguins are able to lay
their eggs on the bare ground.

Little wonder
so many of them choose

to brave the mountainous waves
in order to get here.

Further south,
near the continent,

the blanket of sea ice
is beginning to break up.

Icebergs are gigantic
fragments of ice

that have broken away
into the sea

from the front of glaciers.

During the winter, they were
frozen into the sea ice,

but now they're set adrift
once more.

As the bergs break up,
they form brash ice.

It litters the backwaters
of the Antarctic peninsula.

Minke whales make their way into
these placid waters in summer.

This is the most abundant whale
in the Southern Ocean.

Minkes are one of the smallest
of all the baleen whales,

and like all others,
they come here to feed.

The majestic humpback whales
are also summer visitors.

They have traveled
thousands of miles

from their winter breeding
grounds in the tropics

to gather the food that becomes
available here in summer.

In just four months,
they accumulate enough fat

to provide them with energy

for the whole of
the rest of the year.

All these animals have come here
in search of one thing--

the krill.

Krill is the mainstay
of the Antarctic food web.

It occurs
in phenomenal quantity.

Billions of individuals
in a single swarm,

and swarms can stretch
for miles.

Fur seals also collect
this rich, super-abundant food.

Krill swarms are very patchy,

but once found, feeding is easy.

Humpbacks engulf hundreds
of thousands of them

in a single gargantuan mouthful.

When the going is good,
the whales feed continuously,

each eating up to two tons
of krill in 24 hours.

Further south,
near the continent,
the sea ice is still sound.

Here, where the ice remains
for most of the summer,

emperor penguins
make their home.

These have been feeding
out at sea

and are now ready to make
their way back to the colony

to feed their chicks.

Instead of heading
straight for the ice edge,

the penguins hesitate
some distance from it.

They're nervous.

They dive down
and investigate the ice edge.

And for good reason.

Leopard seals
patrol this border.

Leopard seals are
the Antarctic's equivalent

of polar bears--
they're the top predators.

But they hunt most successfully
in the water,

so, by and large,
the animals they prey on

are safer out on the ice.

They have a lazy grace

that belies
their ferocious nature.

Confident
that the coast is clear,

the emperor penguins
head for the ice.

But they certainly don't linger.

Now they have a long walk
back to the colony.

Emperor penguin colonies are
some way back from the ice edge.

In winter, they may be as much
as 100 miles from it,

but as the summer progresses
and the ice melts,

the edge comes
ever closer to the colony.

So, by the time
the chicks are fledged

and ready to take
their first swim,

the water is close by.

This colony
is in the lee of a headland,

and that prevents the ice

from being broken up
by ocean currents.

The returning adults
are so full of food

that they can barely walk,

but with no predator
to threaten them now,

they can take their time.

Somehow, in this melee
of 60,000 or so penguins,

a parent has to find its chick.

It returns to the place
where it last left its chick

in the hope that it might
still be close by.

But chicks tend to wander,

so the adult has to call to it.

The chick responds,

and they slowly home in
on one another.

The plaintive entreaties

of the chick
stimulates the adult

to regurgitate
a mouthful of fish.

With the return of one parent,

the other is free to go to sea
to feed for itself.

Aware of the leopard seal's
presence,

the penguins press together
at the ice edge,

unwilling to be the first
to risk diving in.

Occasionally,
the seal comes out onto the ice

and attempts to grab one.

But its most successful
strategy by far

is to lie in wait.

It hides behind a corner of ice.

The emperors gain confidence
and make a dash for it.

The first wave of penguins
escape.

Once in open water,
they will be safe.

But the seal is alerted
by the noise,

and through the mass of bubbles,
it makes its attack.

Almost invariably,
it makes a kill.

Encouraged by the absence
of the seal,

the remaining penguins
make a break for the open sea.

In time,
their chicks will fledge,

and when the Antarctic autumn
is near its end,

these adults will walk across
the newly formed ice

to endure yet another winter
on the frozen sea.