The Rite of Passage (Mała matura 1947)

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 ocean 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 II.

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 10,000 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 seagrasses,

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.