Blue Planet II (2017–2018): Season 1, Episode 1 - One Ocean - full transcript

One Ocean takes us on a journey from the intense heat of the tropics to our planet's frozen poles to reveal new worlds and extraordinary never-before-seen animal behaviours.

The oceans, seemingly limitless,

invoke in us a sense of awe and wonder
and also sometimes fear.

They cover 70% of the surface
of our planet,

and yet they are still
the least explored.

Hidden beneath the waves
right beneath my feet,

there are creatures
beyond our imagination.

With revolutionary technology,
we can enter new worlds...

...and shine a light on behaviours

in ways that were impossible
just a generation ago.

We've also recognised
an uncomfortable fact.

The health of our oceans
is under threat.



They're changing at a faster rate
than ever before in human history.

Never has there been a more crucial time

to reveal what is going on
beneath the surface of the seas.

In this first episode,

we will journey across the globe
from the warm waters of the tropics

to the coldest around the poles.

To bring us a new understanding
of live beneath the waves.

This is Blue Planet H.

The surface of the ocean conceals
the many creatures that live beneath

but not all.

Bottlenose dolphins.

They're extremely intelligent.

And with this intelligence
comes playfulness.

They surf.



And as far as we can tell,
they do so for the sheer joy of it.

But to properly appreciate
their true character,

you have to travel with them
into their world.

A pod of bottlenose dolphins is visiting
a coral reef in the Red Sea.

For the youngsters,
there are things to be learned here.

The adults lead a calf
to a particular bush-like coral

called a Gorgonian.

And here, the adults behave
rather strangely.

They deliberately rub themselves
through the fronds.

Their calf seems reluctant to do so.

By watching his elders,

he may be realising
that this is something he ought to do.

Gorgonia fronds, in fact,
are covered with a mucous

that can have anti-inflammatory
and antimicrobial properties.

So maybe the adult dolphins
are doing this

to protect themselves from infection.

The dolphins' intimate knowledge
of the reef

is spurring us to search
for new medicines here, too.

Tropical coral reefs

occupy only a tenth of one percent
of the ocean floor.

But their shallow warm waters
and stable year round conditions,

support some of the most crowded
and varied communities

to be found anywhere in the oceans.

And there are new discoveries to be made
on every one of them.

One creature
on Australia's Great Barrier Reef

is challenging our understanding
of fish intelligence.

A tusk fish.

And you can see why it gets its name.

He does something
few would have believed a fish could do.

Every morning,
he travels to the edge of the reef.

He's searching
for something special to eat

amongst the coral and sand.

Here's one.

A small clam.

But how to crack it open
and get to the meat?

He takes it all the way back

to his special kitchen.

A bowl-shaped coral

that has a particular bump on the inside
that he always uses.

It's not easy if you have no hands.

Whoops.

There he goes again.

But he's got great determination

and surprising accuracy.

At last.

So here is a fish that uses tools.

Some fish are much cleverer
than you might suppose.

The density of the animals
on tropical reefs

makes competition
inevitable and extreme.

Not only for those that lived
within the reef,

but for the birds that fly above them.

During the dry season,

over half a million terns

crowd onto this remote atoll
in the Indian Ocean.

Their chicks are still
in their dark, juvenile plumage.

They vary in age.

Whilst the more advanced chicks
take to the air,

others aren't quite ready yet.

Those just starting to learn to fly

use the shallow lagoon
that occupies the centre of the atoll

as their training ground.

It's difficult for some of them
to stay aloft for long.

Giant trevallies.

Usually, they're solitary hunters,

but about 50 of them have come here
from neighbouring reefs

attracted by this abundance
of potential prey.

The fledglings stay out of the water
if they can,

they even drink on the wing.

If the trevally are to catch one now,

they have to up their game.

So there is a fish here that amazingly

has a brain capable of calculating
the airspeed,

altitude and trajectory of a bird.

The time comes when every fledgling
has to take to the air

and collect food for itself.

Their parents lead them
to the training grounds.

If they're to survive,

they must learn quickly.

After a month of practising
over the lagoon,

the youngsters start to leave

and take their chances
out over the open sea.

The oceans hold 97% of all the water
in the world.

As the sun warms their surface,
water evaporates.

The vapour rises into the sky

until it cools and condenses
into towering clouds.

And they generate huge storms.

The spin of the earth
deflects these storms

north and south into cooler latitudes.

As they travel across the sea,

storm-driven winds create huge swells.

When the swells reach shallower waters,

they rise into gigantic waves.

In its lifetime,
a large storm can release energy

that is the equivalent
of 70, 000 nuclear bombs.

These are the seasonal seas.

And when they warm in spring,

they can suddenly explode with life.

Mobula rays have gathered
in Mexico's Sea of Cortez

in vast numbers.

Why do they leap?

Is it to tell others that they're here?

No one knows.

They feed mostly at night

for that is when vast swarms
of plankton rise from the depths.

The disturbance in the water stimulates
many of the planktonic creatures

to luminesce.

Only now do we have the technology
to record their faint glow.

The feasting rays swim through them

creating an extraordinary ballet
of life and death.

The richness of these waters
is based on microscopic plants,

Phytoplankton,

which bloom on such a massive scale
they benefit us all.

They, together with seaweeds
and sea grasses,

produce as much oxygen

as all the forests
and grassy plains on land.

Every spring off New Zealand,

the seasonal bounty
draws in rare visitors.

False killer whales.

They're relatives of the orca,

six metres long
and weighing over a tonne.

They appear to be searching
for dolphins.

And there are many
in these coastal waters.

Here, bottlenose dolphins stick together

constantly chattering
with whistles and clicks.

Such a din carries for miles underwater.

The false killers have detected them.

Travelling at ten knots,
the killers quickly close in on them.

But then,
something truly extraordinary happens.

The dolphins turn

as if to greet their pursuers.

They seem to change their course.

Could it be that they're attempting
to communicate?

Scientists studying
this annual encounter,

now think that individuals
may recognise one another.

Almost unbelievably,
it seems that these different species

appear to be old friends.

Together they're gathering
as one unified army

up to a thousand strong.

This formidable hunting party
now harvests the riches

that come with New Zealand's summer.

All across the higher latitudes,

seasonal seas flourish
under the summer sun.

Here in Alaska,
sea otters lounge in the canopy

of great submarine forests.

Giant kelp, the biggest seaweed of all
is home to all kinds of life.

On the forest floor, spiny
sea urchins munch through the kelp.

Elsewhere there are continuously hungry
sea cucumbers

And in the tangled undergrowth,

wonderfully camouflaged sea dragons.

In the underwater forests
of northern Japan,

the residents of this sunken wreck

are waiting for the summer temperatures
to reach 16 degrees Celsius.

That for some is the time for mating.

A kind of giant wrasse called a Kobudai.

This is a male.

And in female terms,
he's particularly handsome.

He's a metre long and weighs 15 kilos.

Much larger than the diminutive female,

and he is ready to breed.

He attempts to mate with her

and with any of the dozen or so females
that live in his territory,

whenever he gets the chance.

But females from around ten years old

take little notice of his advances.

This is because when any large female
reaches a critical body size,

she can begin a dramatic transformation.

Over just a few months,

particular enzymes inside her body
cease to work,

and male hormones start to circulate.

As time passes,

her head expands

and her chin gets longer.

A she has changed into a he.

And with this comes a change
in temperament.

The old male who rules
all the females here

is challenged to a face off.

The more bulbous the head,

the more it intimidates an opponent.

The territory has a new ruler.

Only the largest females transform
themselves in this way.

But the change enables them
to have more mates,

so they will have many more offspring
carrying their genes.

But a new male can't afford
to be complacent.

Inside the body of every Kobudai female,

there is a new male in waiting.

The closer we travel towards the poles,
the colder the seas become.

Icebergs appear.

Huge slabs that have broken away

from glaciers that are sliding
into the sea.

And then the surface starts to freeze.

While the lights of the aurora
play above,

even in the depths of midwinter,

there are a few places
well north of the Arctic circle

that are still open.

The fjords of northern Norway
remain ice free

because a giant current,
the Gulf Stream,

flows up here from the south

bringing warmth all the way
from the Caribbean.

And every winter,

billions of herring
come here for shelter.

And following them...

...Orca.

There are up to a thousand of them.

It's possibly the greatest gathering
of orca on the planet.

The herring maybe plentiful
but in these winding fjords

they're not always easy to track down.

These particular orca, however,

are fish hunting specialists.

They work as a team,

coordinating their approach
by calling loudly to one another.

They herd the herring
into tighter and tighter shoals.

They swim below them,

trapping them against
the surface of the sea.

And now the orca deploy
their special weapon.

They beat their tails with such force,

that the shock waves stun the herring.

And then the senseless victims
are easily collected.

But all this underwater noise
attracts others.

Humpback whales.

They move in on the action.

They approach the shoal from beneath
and then lunge upwards,

gathering up to a hundred kilos
of herring in a single mouthful.

The humpbacks are comparative newcomers.

They only started coming here
within the last decade.

But these polars seas are so rich

that there appears to be enough food
for everyone.

Nonetheless, few if any of these riches

would be here were it not
for the Gulf Stream.

Ocean currents, in fact, are crucial
to the well being of our planet.

They distribute the sun's heat
towards the poles

all the way from the equator,

maintaining a climate favourable
for life almost everywhere.

From creating the weather
to producing oxygen,

the seas keep our world healthy.

But there are now worrying signs

that conditions in the oceans

that have remained relatively stable
for millennia

are changing radically.

Nowhere is this more evident
than in the Arctic.

Here in the past 30 years,

the extent of the ice in summer
has been reduced by 40%.

This sudden warming,

most likely a consequence
of human activity,

is having a profound impact
on its wildlife.

Walruses are among those
that are seriously affected.

Every adult female
needs to find a safe place

where her 80-kilo pup can rest.

The sea ice is retreating

from much
of the walrus' traditional range,

so they now have
to haul out on dry land.

But a herd of hundreds
of quarrelsome mothers,

some weighing almost a tonne,
is not an ideal nursery.

Walruses on land stick together
for good reason.

Polar bears.

A full grown male walrus is gigantic,

too big for even a polar bear to tackle.

So the bear is looking
for a walrus baby.

The scent of the bear
spreads alarm through the colony.

The walruses retreat into the sea.

The bear knows it won't be able
to catch them there.

But she too has young ones to feed.

What is a mother to do?

A mother walrus still needs
to find a place

where her young can rest.

A melting iceberg might do,

but she is not the first
to find this one.

Suitable places are already taken.

Other mothers don't want to share.

They, too, need a patch of ice
where they can protect their young.

A desperate mother has no choice
but to barge her way in.

So this time everyone loses.

Finding the right place
on these melting shores

gets harder and harder.

Solving these problems together
helps create a bond so strong

that the mother will stay in contact
with her young for the rest of her life.

But who knows now
what their future will be.

As we understand more
about the complexity

of the lives of sea creatures,

so we begin to appreciate
the fragility of their home.

Our blue planet.

Next time.

The deep.

A world richer
than we ever though possible,

where creatures thrive,

in the most extreme conditions on Earth.