All language subtitles for BBC.Asia.1of7.Beneath.the.Waves.1080p.HDTV.x265.AAC.MVGroup.org_track3_[eng]

Of all the wonderful places
in the world, one continent holds

more riches than any other.

It covers almost
a third of the land on Earth.

In the south, stand vast forests.

And to the north...

..lies an immense frozen wilderness.

Much of the centre is
dominated by deserts.

And at its heart are the world's
highest mountains.

Off the coast of this continent,

stretch the richest seas on Earth.

And that's not all.

This is the most populous place on
the planet.

Here, animals live alongside humans
in the most remarkable ways.

If you think you've seen the best
the natural world has to offer,

think again.

There's nowhere else on Earth
with so many untold stories.

Welcome then, to Asia.

Asia is the largest continent on
Earth.

With a coastline over 100,000
miles long,

it's surrounded by three oceans
and 21 seas.

Its waters stretch from Arabia,
through the Indian Ocean

and Southeast Asia, to the
edge of the Pacific.

Connected by some of the world's
most powerful currents...

..these seas are the richest
on the planet.

And the animals in Asia's oceans are
as spectacular as they are diverse.

In the warm waters
of the Western Pacific,

lives a dramatic little fish, with
pouting lips and dazzling stripes...

..the flamboyant Moorish idol.

This one is looking for a partner.

Moorish idols normally breed in
pairs.

But here, they do something that
no others of their species do.

They congregate in huge numbers...

..before swimming away from
the reef, to spawn.

But so many fish attract attention.

A grey reef shark...

..and it's not alone.

With so many hiding places,
there is safety on the reef...

..but they must get out past
the sharks.

Finally, they make a break for it.

Now in open water,
they can swim into the blue.

But they've been spotted.

A few sharks can be avoided...

..but hundreds are
a different matter.

To have any chance of survival,
they must stay in a tight group.

The sharks try to split them up...

..and pick them off.

After two hours of chasing,

only the strongest are left.

The few survivors swim in tight
spirals, desperate to avoid capture.

The sharks, tired and full,

one-by-one, abandon the chase...

..until only the luckiest
and fittest Moorish idols survive.

No-one knows exactly
where they spawn.

But the developing young are carried
away to safety by the currents.

From the Western Pacific,
comes one of the most powerful

currents in the world -
the Indonesian Throughflow.

It sweeps between Borneo
and Sulawesi, and into

the Flores Sea, where it hits
Indonesia's Lesser Sunda Islands.

Here, water is forced between
the islands at a rate

of 15 billion litres a second.

And this produces some of
the world's most intense currents...

..and whirlpools.

Off the island of Komodo,

the water is funnelled into
fast-flowing torrents,

which concentrate the plankton
it carries...

..providing food...

..for giants.

Manta rays.

With a wingspan
of up to five metres,

these mantas exploit
the powerful currents.

They feed by filtering plankton from
the water.

Such a feast makes this an excellent
place to produce young.

When the adults need a break, they
head off for a bit of pampering.

Out of the main flow
are cleaning stations,

staffed by hundreds
of butterfly fish.

The cleaners remove parasites
and dead skin,

and get a meal in exchange
for their services.

And the mantas get a welcome break
from the ripping currents.

Refreshed,
they can go back to feeding.

As the Indonesian Throughflow
continues, one branch flows

past Bali, to Java and
some of the richest

coastal forests on Earth...

..mangroves.

These are places where nothing
is as you might expect.

Trees grow in the sea...

..and fish live on land.

A dusky-gilled mudskipper...

..only five centimetres long,

but a master of these swamps.

As long as they can stay wet,
they can absorb oxygen from the air,

and they spend most of their life
out of water.

Joints in their pectoral fins
enable them to walk...

..and they can leap with
a flick of their tail.

This one is seeking a mate with
whom to start a family.

But first, he needs to dig
a breeding burrow.

Mudskippers will shift up to 300
times their body weight in mud,

one mouthful at a time.

Tiring work!

With the dirty job done,

it's time to find a female.

But the mangroves are full
of obstacles.

A special set of grasping belly
fins, however,

enable skippers to become climbers.

And when there is a dead end...

..a mudskipper simply skips
across the water's surface,

a metre at a time.

What's this?

An open arena...

..full of females.

Excellent!

But there are also other males here
looking for partners.

To win a female, they must duel.

But no-one is backing down.

Victory and the opponent
beats a hasty retreat.

And it looks like this male...

..has caught someone's eye.

A quick wave should seal the deal.

It's a date.

They head back to his place...

..ready to start a family of
their own.

Mangrove forests are essential for
the survival of Asia's mudskippers.

And trap four times more carbon
than forests growing on dry land.

Today, Southeast Asia holds
a third of what is left of these

precious forests...

..adding clean, fresh water
to the Indonesian Throughflow,

as it travels.

Sweeping away from Indonesia,

the current heads west across
the vast Indian Ocean...

..carrying with it a whole host of
drifters.

And some objects provide
entertainment

for one of Asia's giants.

A baby sperm whale plays
with a mangrove seed,

so practising his coordination.

He produces pulses of high frequency
sound from his large head,

sonar that will eventually enable
him to locate prey

in the black depths...

..and zeroing in on a tiny seed
is great practice for doing so.

When you're as big as this,

grabbing something
the size of a pencil is not easy.

With play over,
it's time to get back to the family.

The grown-ups are taking a nap.

It's thought that the reason
they sleep upright is to make it

easy to bob up for air.

The calf is keen to join in.

But it's not as easy as it looks.

Staying vertical takes practice.

And when you get the hang of that,

the next challenge is buoyancy.

Holding just the right amount of
breath is an art.

Too little and you sink.

The adults tenderly correct
his mistakes.

He still has a lot to learn.

In his 70-year lifespan,

he will explore
much of the Indian Ocean.

From here, the Indonesian
Throughflow continues west...

..but a very different kind of
traffic is moving northwards.

Shipping.

Major international cargo-lanes
run from the Indian Ocean

into the Red Sea, which divides
Asia from Africa.

At its Northern end
is the Suez Canal.

One third of the world's container
freight travels along it

and emerges into
the Mediterranean...

..one of the planet's
most polluted seas.

Here, on Asia's westernmost
coastline,

this Israeli power station
discharges water ten degrees hotter

than the surrounding sea.

Astonishingly, this has become
a refuge for one of the most

vulnerable of species...

..dusky sharks.

Mediterranean sharks
are the most endangered on Earth.

But up to 100 females
come here in winter...

..and each one of them is pregnant.

It's thought the warmth speeds up

the development of
their unborn young.

This power station has created
a shark sanctuary by accident.

But elsewhere in Asia,

deliberate steps are being taken
to protect marine life.

Over 5,000 miles away on the other
side of the continent...

..life is booming
in the unlikeliest of places...

..the tiny island of Tyuleniy,
in far-eastern Russia...

..a disused hunting settlement.

Here, enormous numbers of
fur seals were once killed

annually for their skins.

But hunting restrictions have
produced a spectacular recovery.

Over 100,000 Northern fur seals now
come here each summer.

It's one of the largest colonies in
the world.

The beaches are jam-packed.

BLEATS LOUDLY

Huge, territorial males
compete for space.

It's dangerous for the tiny pups,

which weigh just
a 50th of the adult bulls.

The aggressive males are only
focused on the next challenge.

When fights break out,
the pups are ignored.

In the aftermath,
many pups lie injured.

Life on the beach
is full of danger...

..but it's no safer in the sea.

Orca.

Fur seals returning from fishing
must run the gauntlet.

But these orca are specialists...

..ramming and tail-slapping
to stun their prey.

And when their victim has been
disabled...

..they drown it.

Many pups are left as orphans...

..but enough will survive to support
this now healthy

population of Northern fur seals.

This richness in Asia's
shallow seas can also be

found in some of its deepest waters.

Every night, billions of creatures
travel up from the abyss.

It's the largest regular movement of
life on the planet.

Strange life-forms come up to feed
in the surface waters...

..among them jelly-like salps,
which have tiny crustaceans

living inside their bodies.

As dawn arrives, they return
to the safety of the deep.

But some creatures, gathering
in the Sea of Japan, are about

to embark on a one-way trip
out of the depths, never to return.

Firefly squid.

They live for just 12 months.

It's thought that they use
their blue bio-luminescent lights

to confuse predators...

..and their green lights to
communicate with one another.

No other deep-sea
animal can see green.

It's the squids' own secret code.

Some quarter of a billion females
are heading to the surface.

In the shallows, they lay
thousands of eggs in strings...

..the final act of
their short lives.

With this done,
their bodies are programmed to die.

Here, on the north coast of Japan,

they wash up on the beaches
of Toyama Bay.

Their lights fade,
as life drifts away.

Their eggs, however...

..are beginning to hatch.

Sinking into the vast darkness of
the deep sea,

they won't return to shallow water
for a year,

when it will be their turn to lay
eggs and then die.

2,000 miles south,
in the western Pacific, lie wide

expanses of shallow seas
around the Philippines,

Malaysia and Indonesia...

..the so-called Coral Triangle.

Here, there are more abundant
coral reefs than anywhere else.

It's the richest concentration
of marine life on the planet.

Three-quarters of the world's
coral species are found here...

..and over 3,000 species of fish.

It's every bit as diverse
as the Amazon rainforest.

Coral reefs truly are the ocean's
bustling cities.

Many residents have evolved
ingenious ways of solving

the problems of living in such
close quarters.

But some appear to be
completely defenceless.

Meet the sea bunny.

Just a few centimetres long,

this tiny sea slug has no shell for
protection...

..no eyes to spot danger...

..and travels at a snail's pace.

It's looking for food.

What appear to be its ears are, in
fact, finely-tuned chemical sensors,

that enable it to "smell" its way to
its next meal.

But on the reef,
predators are everywhere.

When you can't see...

..it can be hard to avoid trouble.

Alien-like beasts patrol the nooks
and crannies of the reef.

This one filters its food
from the water...

..and is no threat to the sea bunny.

But not everything here is quite
so harmless.

The Moray eel, powerful and fast...

..but apparently not keen on slug
for dinner.

A scorpionfish, one of the reef's
most deadly inhabitants.

Extravagantly camouflaged,
it waits for prey to come close...

..then swallows them whole.

But the sea bunny just walks all
over him.

And now, it's headed straight
for a deadly-poisonous blue sponge.

Blind and hungry,
it's about to take a bite.

It seems that its luck
has finally run out.

But, no,
this is actually its favourite food.

It's immune to the poison...

..and by eating the sponge,

the sea bunny has made itself
toxic to predators.

No wonder it's untouchable.

As long as it can maintain its blue
sponge diet,

the sea bunny will be protected
against the dangers of the reef.

With so many complex survival
strategies...

..life for predators
on the coral triangle

can require complex tactics.

This snake, a black-banded
sea krait,

has venom ten times stronger
than a cobra...

..a forked tongue that enables it
to sniff out prey underwater...

..and a flexible body,

so it can squeeze into crevices
on the reef to look for prey.

A formidable killer, it would seem.

Yet, hunting fast prey is not
one of its abilities.

It's slow with poor eyesight,
hardly the deadliest of assassins.

If only it were fast and agile...

..like these bluefin trevally.

They rely on sheer speed
to catch their prey.

Unlike the snake,

they are too big to get between
the arms of the coral.

But these two struggling species
have found a solution.

They work as a team.

The trevally leads...

..indicating places where prey could
be hiding...

..which the snake then investigates.

As they roam the reef,
they're joined by more trevally...

..and more snakes.

Soon, they are an army.

The trevally find a target.

The snakes head in...

..and the trevally cover
the escape routes.

There's nowhere left to hide.

The trevally catch the fish
that are flushed out...

..and the snake eats anything
left inside.

Each species benefits
from the partnership.

The hunts are so successful that
they attract

hundreds of trevally and snakes.

This behaviour is extremely rare,

and has only been seen in
Asia's coral triangle.

Innovation and teamwork are critical
to success

in these competitive waters.

These relationships and strategies
developed over millennia,

are a consequence of
the extraordinary richness of

Asia's seas.

And whilst our influence
is now not far away,

Asia's oceans still remain
a world of wonder,

offering spectacles not found
anywhere else on Earth.

The Asia team explored many
of the continent's 21 seas.

They spent thousands of hours
underwater,

filming the spectacular diversity of
life.

But their biggest challenge
was getting up close with

some of the most powerful currents
on earth.

The Indonesian Throughflow carries
ten times more water than all

the world's rivers combined.

The tide has to make its way
from the Pacific to the Indian,

and that's a huge amount of water.

And as it does that,

it gets squeezed through
these islands, which

creates intense currents, but also
brings an incredible amount of life.

The team want to capture
this immense power up close...

..but the fast currents are making
filming difficult.

For their first attempt,
they use a pole-mounted camera.

But getting the boat into position
is almost impossible.

We're fighting a losing battle.
Yeah. We'll drop it.

Let's go back to the main boat.

David thinks he has a solution,
but it's radical.

He's going to get in the water
himself,

using a floating camera rig
to film inside the vortex.

We'll see the swirling water,
literally the opening of the

funnel of the whirlpool, that's what
I want, it's like the epic shot.

If the shot works, it's going
to be amazing.

It's going to really tell
the story of the currents nicely.

So, I think what we have to do is
put David up current, initially,

but close-ish in to the island,

to get those swirls,
as you come past.

What's the normal advice for divers
here?

Normally, we'll actually jump right
next to the island where there's no
current.

They stay out of the current
entirely... Yes.

..which is the opposite to what
you're going to be doing! Yes.
OK, yeah.

This challenge is unlike anything
David has faced

in 30 years of film-making.

I'm going to add two life jackets
to the camera rig, and you know

if I start to get sucked down I'm
going to just hang on to that.

The key to staying safe will be
buoyancy.

Yeah, I don't know
if I can get this third one on.

Three life jackets should resist
the pull of the whirlpools.

It's not that bad.

What do you think? Money? Yeah.

The team decide to dive on
the rising tide

when the currents are weaker.

I think I'm plenty floaty!

David's home-made protection
is holding up well.

The current is running fast,
but the whirlpools aren't forming.

David, nothing? Nothing.

Nothing at all? Like, I... I feel
the current, and I, like, I don't

see any, like, whirlpools, bubbles,
hardly anything in the water.

Do you want picking up?

Yeah.

It seems that
if David is to get his shots...

..he will have to brave the much
faster falling tide.

Preparation will be key to success.

Whirlpools only last a few seconds,

so to get in the right position,
the team needs eyes in the sky.

Drone's in the air.

OK, copy, copy.
What do you guys see?

The current looks strong on that
eastern edge of the island.

If you can spot good places where
the whirlpools are cropping up...

Mark, Mark, the swirl's
forming on the edge you're at.

Right, thanks, mate.

Look, we've got some,
definitely some forming here.

David must get to the whirlpools
before they dissipate.

Is this a good spot?
Yeah, I call it right here.

OK, clear to go.

You're going to get
sucked in pretty quickly.

Behind you, David.

Mark is ready with a throw rope, in
case of trouble.

You OK?

Do you want the rope?

He's OK.

He wants to carry on.

David's commitment is paying off.

He's starting to get the shots.

But the whirlpools are growing
stronger.

That is putting him
right in the whirlpool zone.

He's getting sucked in.

All he can do now is hang on.

OK, can we get closer to David?

Whoa!

At last,
the whirlpool spits him out.

David, you OK?

Yeah.

It's hairy. It's not doing anything
for my nerves, let alone David's.

It's time to get
back into the safety of the boat.

OK? Yeah.

It had me. Like, I could feel myself
going bloob, bloob, bloob, blub,
blub.

Really? Like that, but I had,
I had enough, I kind of kept
my hands on the camera.

Yeah. I didn't even see it coming,
suddenly I was like...
Yeah, yeah, yeah.

A good whirlpool, huh?

David's plan has succeeded.

Yeah! He's faced Asia's ripping
whirlpools,

and captured their fierce beauty, as
never before.

Next time, we journey to Asia's
remarkable mountains...

..a world full of surprises...

..and home to some of the most
captivating creatures on the planet.