All language subtitles for The.Blue.Planet.S01E02.The.Deep.1080p.AMZN.WEB-DL.DD+2.0.H.264-playWEB_track3_[eng]

Over 60% of our planet

is covered by ocean
more than a mile deep.

That, the deep sea,
is by far

the largest habitat
on Earth,

and it's
largely unknown.

Join us on a journey to
the very bottom of the deep sea,

to an alien world
never revealed before.

It's home to some of
the strangest animals on Earth.

Fish flash
in the darkness.

New species are discovered
on almost every dive.

More people have
traveled into space

than have ventured
this deep.

Come on a journey
into the abyss.

A sperm whale takes a breath,
its last for over an hour.

It's about to
leave the warm,

well-lit surface waters,

and dive far down
into the cold,

dark depths
of the deep ocean.

At the surface,

it took in air at the same
pressure as we breath it.

But it's going to
look for food

at more than
1,000 meters down,

where pressure is 100 times
that on the surface,

crushing the whale's lungs
to just 1% of their volume.

For us to follow
the whale,

we need the very latest
submersible.

A reinforced acrylic sphere
with walls 12 centimeters thick

protects a pilot
and our cameraman

from the enormous
pressure below,

and allows the submarine
to dive to just over 900 meters.

With every passing meter,

pressure increases,
and sunlight diminishes.

1,000 feet.

By 300 meters,
it's already very dark,

and the temperature of the water
is dropping fast.

My depth is 1,755.
Temperature is...

We are entering
the twilight zone,

a weird world of gloom,
where many animals

have become completely
transparent.

In this twilight,
an animal needs to see,

and yet,
as far as possible,

must avoid being seen.

A giant amphipod,
12 centimeters long,

and almost perfectly
transparent.

Its head is completely filled
by two huge eyes,

with which it strains
to detect its prey.

Another twilight monster,
Phronima,

the inspiration for
the Alien movies.

She and her developing
pink offspring

live like parasites
in the stolen body of a jelly.

This impressive
cutlery set

and its huge eyes
make Phronima

a powerful predator.

Even really complex animals
have become transparent

in the twilight zone.

Squids are among the most
advanced of invertebrates,

but this one never meets a hard
surface in its entire life,

so its body need not be
as robust

as that of its
shallow-water cousins.

There's a rich variety
of jellies

that live nowhere else
but in the deep sea.

Thousands of tiny cilia
propel them

through a world
without walls.

Invisible in the gloom,

they grope blindly
for their prey.

Comb jellies let out long,
sticky nets

to catch
passing copepods.

But the most extensive
death trap

is set by
siphonophores.

This pulsating bell is
the head of a colonial jelly

that can be
40 meters long.

Millions of tiny stinging cells
drifting through the sea.

500 meters down,

and in even the clearest
tropical waters,

only the faintest vestige
of the sunlight remains,

so little that our eyes
can't detect it.

But others can.

Survival in
the twilight zone

is all about seeing
yet not being seen.

Hatchetfish are masters
of the game of hide and seek.

They have the large,
sensitive eyes

needed for
seeking prey,

but their bodies
are flat.

And their sides
are highly silvered.

Head-on, they are just visible,
thin though they are.

But as soon as they turn,

their mirrored sides
reflect the remnants

of blue light
from the surface,

and they disappear
into the gloom.

Viewed from the side,

whole shoals can hide
in this way.

But what about
from below?

The tubular eyes
of many of the predators,

even in this gloom,

are able to distinguish
their prey silhouetted against

the scarcely detectable glimmer
of light from above.

Hatchetfish, however,
have a way of confusing any eyes

that might be searching
for them from below.

Their bellies carry rows

of light-producing cells
called "photophores."

They can use these
to exactly match

the changing color of light
from the surface far above.

This counter-shading
breaks up their silhouette,

making them almost invisible
from below--

almost.

But these are
no ordinary eyes.

The enormous yellow lenses
enable their owner

to distinguish
between light

produced by photophores
and sunlight.

So, one device for escape
is countered by another

equally subtle one for attack
in an evolutionary arms race

that has been waged
for millions of years.

Let's begin.

My dog is one of us.

You and me, girl.

Home protection?
Hunting.

Out here,
most folks let things go.

I guess I'm not
most folks.

I want to live.

Are you prepared to kill?

Yes.

One of us is not
leaving this island.

You ready?

Descend below 1,000 meters,
and you enter the dark zone.

No sunlight whatsoever
penetrates this deep.

The temperature
of the water

has dropped below
4 degrees centigrade.

The pressure is more than
100 times that at the surface.

Life becomes
ever more sparse.

It's a dark,
dangerous world.

Relative to body size,

these are the largest teeth
in the ocean.

They're so big that their owner
can't even close its mouth.

They belong to
the fangtooth.

Unlike most deep-sea fish,
this has powerful muscles,

and is
an aggressive hunter.

With food in such short supply
at this depth,

dark-zone predators
have to be able to deal with

a meal of almost
any size.

Many animals here are dark red,
like this deep-sea jelly.

Caught in the lights
of the submersible,

it's a spectacular
firework display of color.

Normally, no red light
penetrates as deep as this,

so animals with
red pigment

appear completely black
down here,

perfectly concealed.

Predators here, however,
don't just rely on vision.

Many have tiny eyes.

Instead, their thin rod-like
bodies are lined with organs

sensitive to tiny movements
in the water.

This monster,
half a meter across,

is a hairy angler.

This is the first time
it's been seen.

It's covered with hundreds
of sensitive antennae,

each capable of detecting
the movements

of any prey
careless enough to stray

too close to this
motionless predator.

But this surely must be
the strangest of all

the deep-sea fish
yet discovered.

A highly sensitive
meter-long tail

hangs down
from the head

that makes up
a quarter of its body.

Its eyes are tiny,
but its mouth is truly enormous.

It's called the "gulper eel"
because it can engulf a meal

of almost any size.

Hanging motionless
in mid-water,

its enormous gape enables it
to deal with passing prey,

whether it's small
or large.

Gulper eels can swallow prey
as big as themselves,

which is very useful in a world
where you never know

when the next meal
is coming along.

Even in the dark zone,
there is some light.

Turn off
the submersible headlights,

and you see a pyrotechnic
display outside.

These lights are created
by animals.

This is bioluminescence.

A deep-sea anglerfish
flashes in the darkness.

The light is generated
by bacteria

that live permanently
inside the lure,

which attracts prey
to these murderous teeth.

There are all sorts of lures
out in the darkness.

"Come into my mouth,
little fish."

And what is the purpose
of this lure,

suspended on a long rod,
way below

its owner's terrifying
set of teeth?

It's difficult to be sure,
but then, this monster does have

another giant flashing lure
much closer to its mouth.

These fish are called "anglers"
because they use their lures

in much the same way
as fly fishermen

use their imitation flies.

For a hunting squid
with huge eyes,

this glimmer
is intriguing.

It might just be food.

A satisfying meal
for a fish

with a highly
extendible stomach.

Attracting a mate
in this endless darkness

can be even harder
than finding food.

Flashing lures may be helpful
in doing this.

Certainly only
female anglers have them.

The tiny males are just a tenth
the size of the females.

Their only purpose
is somehow

to find a mate
in the darkness.

She releases chemicals
into the water,

which the males scent
with a special white organ

in front of their eyes.

Having found a partner,
the male bites at her belly

with specially
designed teeth.

He needs to get
permanently attached.

Within a matter of weeks,

the male is completely fused
to the female,

and there he will stay
for the rest of his life.

Her blood
circulating in his body

provides him with
all the sustenance he needs.

In return,
she gets a continuous,

reliable supply
of sperm--

a brilliant solution
to the problem

of finding a mate in the vast
emptiness of the deep sea.

To help in the constant battle
between predators and prey,

some fish in the dark zone
have developed headlights.

These light-producing
photophores beneath their eyes

may be used to search out prey
in the darkness.

Most bioluminescence
in the deep sea

is blue or greenish-blue,

but a very few predatory fish
produce red light.

With this, red prey becomes
obvious in the darkness.

Red light is rare
down here,

and most animal eyes
can't see it.

Only these fish
can do so.

This gives them
a sniper scope,

a headlight invisible
to their targets.

This copepod, un-alarmed,
takes no avoiding action.

Bioluminescence is useful
in escape as well as attack.

A shrimp
senses a threat.

It spins in the water,
releasing a bioluminescent glue.

This acts like
a burglar alarm,

startling
the attacking fish,

and leaving it illuminated
in the dark,

and vulnerable
to its own predators.

These twinkling lights
in the darkness

are produced
by copepods.

They probably
flash like this

to communicate
with one another,

and confuse
their predators.

The most sensitive eyes
in the ocean

belong to an ostracod
called "Gigantocypris."

It's the size of a pea,

but that's enormous
for an ostracod.

Copepods are a favorite prey,
and it actively searches for

their flashes
in the darkness.

But this copepod
has a way of confusing

a hunting Gigantocypris.

It discharges a packet
of bioluminescent liquid.

The flash is delayed,
like a depth charge.

Spinning, confused
in the water,

Gigantocypris chases
after the flashes.

And the copepod slips away,
unseen, into the darkness.

The ultimate bioluminescent
defense mechanism

has to be the light show
created by

the deep-sea jellyfish
periphylla.

That, presumably, is the way
it scares away its enemies.

These bright lights are all
produced by firefly squid.

Normally, they live way down
at around 300 meters,

beyond the reach of these
Japanese fishermen's nets.

But for a few months
each spring,

they come to the surface
every night.

The brightest lights come from
the bioluminescent tips

of their two
front tentacles.

But it's only in the dark
of the deep sea that you can

really appreciate
the full complexity

of their displays.

It's not just
their tentacles,

but their whole bodies,
that are covered in photophores.

The exact function
is not clear.

The bright tentacle tips
may be for attracting mates

or dazzling predators.

The rest may be
camouflage,

providing counter-shading
for the squid

as they journey up into
the twilight zone.

Every night
in the season,

hundreds of thousands
of squid

journey up into
shallow water to spawn.

Before dawn,
they will return to the depths,

leaving their eggs to develop
in the shallows.

The daily cycle of the sun
has a profound influence

on life in
the deep ocean.

As the sun sets, it triggers
the largest migration

of living organisms
on our planet.

1,000 million tons
of animals

travel up from the dark zone
into richer,

shallower water
every night.

Tiny grazers
are first up,

searching for
the microscopic plants

that only grow in shallow,
sunlit waters.

Predators follow
the grazers.

An enormous variety
of different animals

join the convoy,
or feed off it as it passes.

Many will travel up
hundreds of meters

towards the surface,
and then, at dawn,

finding themselves
at greater risk from predators,

the visitors return to the safer
darkness of the depths.

The sun's rays only have
a direct effect

in the top hundred meters,
or so, of the ocean.

It's only here that
photosynthesis can take place,

and coral reefs
can flourish.

Leave this thin,
rich slice of life,

and travel over
the outer face of the reef,

and you quickly enter
a far more demanding world.

Below 150 meters,

photosynthesis
becomes impossible.

You find no plants,
just animals.

Here, the animals are adapted
to catch marine snow--

particles of dead animals
and plants

that drift down
from above.

So, they depend,
second-hand,

on the energy
captured from the sun

by organisms living in
the surface waters.

Traveling close to
the sea floor,

we're going to take a journey
to the very bottom

of the deep sea,

to a world completely separate
from the mid-water above.

At around 300 meters,
the drop-off levels out,

and we move out onto
the continental slope.

This stretches for about
150 miles from the coast,

sloping in
a gentle gradient

down to a maximum depth
of 4,000 meters.

Water temperatures down here
drop below 4 degrees centigrade,

and the pressure can reach up to
400 times that of the surface.

Without the lights
of the submersible,

it would be
completely dark.

The water
is crystal clear

because there's so little
organic matter.

Only 3%
of the potential food

in the surface waters
reaches the continental slope.

At first sight,
it appears a lifeless desert.

But take a closer look,

and you notice a network
of tracks and trails.

There is life,
even down here.

These animals
would die immediately

if brought to the surface
in nets,

so you can only see them
behaving normally

from submersibles.

Many are new
to science.

The deep sea floor
is dominated

by echinoderms--
sea cucumbers,

brittle stars,
and sea urchins.

There are literally
millions of them

marching across the seabed,
hoovering up

any edible particles there
might be in the sediment.

They come in all sorts
of shapes and sizes,

and though they are
very thinly spread,

the deep ocean floor is so vast
that these are among

the most numerous animals
on the planet.

Their spikes are good
for locomotion and defense,

but perhaps not quite so good
when it comes to mating.

Finding a mate
in this largely empty sea floor

could be a problem, so some
urchins stay together on herds,

to be sure that
they're never too far

from a potential partner.

Rocky outcrops provide
good anchorage for animals

that rely on food
that might drift past.

These crinoids,
or sea lilies,

look like plants,
but are, in fact, animals.

Their long stalks
ensure that their umbrella,

of feeding tentacles,
are positioned

to best effect
in the current.

Particles are swept
onto the arms,

and carried down to a mouth
in the middle of the umbrella.

These sudden movements
swat away tiny amphipods

that try to steal
the sea lily's captures.

Coral reefs are not
supposed to exist

in total darkness,

but recently,
a new kind of coral

was found as deep
as 2,000 meters.

In the cold waters
of a Norwegian fjord,

there was a deep-sea reef
30 meters high

and 200 meters long.

This coral gets no energy
from the sun,

so it has to be very efficient
in catching food.

Its polyps
are far larger

than those of
shallow-water corals.

These are, in fact,

the largest coral polyps
in the ocean.

They belong to
the deep-sea mushroom coral.

Their 3-centimeter-long
tentacles can catch

far larger prey
than other corals can.

This necessity to capture every
particle of food

that comes within reach
in this near desert

has radically changed
many animals.

Most tunicates
are filter feeders,

but this one, uniquely,
has become a predator,

and its greatly
enlarged siphon

has been converted
into a trap.

Most sea cucumbers
stay firmly on the bottom,

but not this extraordinary
deep-sea species.

Its skirts of skin
allow it to swim

hundreds of meters
above the sea floor.

Eventually, it will descend,
and, with luck,

will land on fresh
feeding grounds.

This, though, has to be
the most extraordinary

animal design
of all.

It's a polychaete worm,
and normally, you would expect

the long, pulsating body to be
stuck firmly in the sediment.

This worm, alone in its group,
swims in the open water.

Propelling itself
with its yellow frill,

it moves about, and so finds
new sources of food,

or maybe succeeds in escaping
from a predator.

This is chimaera,
a close relative of the sharks,

less than a meter long.

Sensory pits on its chin help it
hunt prey on the bottom,

while its surprisingly
large eyes may help it

spot bioluminescence.

Large fish
are rare down here.

There's simply not enough
live prey to sustain them.

Most have become
scavengers.

A dead tuna has attracted
a deep-sea conger eel...

and a sixgill shark.

These monsters grow to
8 meters long.

Sixgills are
living fossils.

For 150 million years,
they have existed unchanged,

living in water as deep
as 2,500 meters.

Very few people
have ever been lucky enough

to glimpse these sharks
from submersibles,

and we know almost nothing
about their behavior.

The body of a tuna
is a substantial meal,

but just occasionally,
a really gigantic corpse

drifts down
to the deep sea floor.

This is the freshly dead carcass
of a 30-ton gray whale.

It's resting on the sea floor
a mile down.

It's only been on the bottom
for six weeks,

but already, it has attracted
hundreds of hagfish.

These ancient scavengers
are nearly always

the first to discover
a fallen body,

and are attracted
from miles around.

They lack jaws,
and rasp at the flesh

with two rows of horny teeth
on either side

of their
sucker-like mouths.

Next to arrive,
a sleeper shark,

a real deep-sea
specialist.

They grow to over
7 meters long,

and have never been filmed
at such a depth before.

The gaping wounds in the whale's
flank are its work.

Unlike the hagfish,
it has powerful jaws,

so it's able to rip off
huge chunks of meat.

Sharks, hagfish,

and a whole succession
of different deep-sea scavengers

will feast on the carcass
for years

before all its nutriment
has gone.

18 months later,
when we returned to this whale,

all that was left was a perfect
skeleton, stripped bare.

It was almost as if
a museum specimen

had been carefully laid out
on the sea floor.

At first, the skeleton
seemed totally abandoned.

But even after so long,

there was still some flesh
left in the head.

Hagfish have a skeleton
of cartilage,

and are so flexible that they
can tie themselves into knots,

and so get a better purchase
on the flesh they feed on.

But smaller organisms
had fed here.

A thick band of white bacteria
had formed on the mud

outlining the original shape
of the whale.

And on the skeleton itself,

colonies of specialized bacteria
were extracting energy

from the bones
themselves.

Most remarkably,
and in huge abundance,

polychaete worms were collecting
the last edible fragments.

These are a new species that,
so far,

have only been found on
the fallen bodies of whales.

Scientists have discovered
178 different animals

on a single
whale vertebra,

most of which have been found
nowhere else.

This whale,
lying over a mile down,

was not filmed
from a submersible

with an acrylic sphere.

Such craft can't go
as deep as this.

To withstand
the pressure here,

you need a far stronger
submersible.

This is Alvin,
a 2-meter-wide sphere

with just enough
room in it

for a pilot
and two observers.

Its walls are made
of titanium.

The viewing ports
have to be tiny.

Any larger,
and the submersible

would implode under
the enormous pressure down here.

Alvin can dive
to 4,500 meters,

3 miles below
the surface.

Around 3,000 meters,
the continental slope

finally flattens out,
and joins the abyssal plain.

This covers over half
the Earth's surface.

Mostly, it's completely flat,
but in places,

it's gashed by massive trenches
hundreds of miles wide.

The deepest of these
is the Mariana Trench,

which drops to over 7 miles
below sea level.

There are just five
manned submersibles worldwide

that can reach
the abyssal plain,

and between them, so far,
they have explored

less than 1% of it.

There are 1,000 times fewer
large animals down here

than on
the continental slope,

but in places,
hundreds of brittle stars

march over the sea bed
in search of food.

Fish have been found
right down to the bottom

of the deepest trenches.

Most come from one family,
the aptly named "rattails."

They forage
near the sea floor,

and use their battery
of sensory pits

to follow odor trails
from rotting carcasses.

Rattails can travel
long distances

across the abyssal plain
in search of food,

but others down here
prefer to sit and wait.

This is a tripod fish.

It supports itself on two
specially adapted fin rays,

and can sit motionless
for hour after hour.

It does have tiny eyes,
but it's almost totally blind.

It locates potential prey with
a pair of fins behind its head,

which are sensitive
to even tiny movements.

We know more about
the surface of the moon

than we do about
the abyssal plain.

Every dive still produces
complete surprises.

This deep-sea octopus is
about the size of a beach ball,

and has been
nicknamed "Dumbo."

An umbrella of skin
between its tentacles

and its extraordinary
flapping ears

allow Dumbo
to hover effortlessly

over the sea floor
as it searches for food.

Right in the middle
of the abyssal plain

lie the largest geological
structures on our planet...

...the mid-ocean ridges.

Rising almost 2 miles
off the sea floor,

the ridges extend
for over 28,000 miles,

the largest mountain chain
on Earth.

When submersibles
finally succeeded

in reaching the ridges
in the 1970s,

they found an extraordinary
world with mile upon mile

of once-molten rock
that had welled up

from the deep in the past,
and had now solidified.

They discovered
towering chimneys

pouring out water
as hot as molten lead.

At the surface, water becomes
steam at 100 degrees centigrade,

but down here, under the immense
pressure of the ocean,

it remains liquid
at temperatures

as hot as
400 degrees centigrade.

The submersible
has to move carefully.

Disaster is very close
when surrounded by

such enormous temperatures
and pressures.

And here,
where the very water

is loaded with
hydrogen sulfides

poisonous to normal
life processes,

they found
living creatures.

Some of the chimneys were
encrusted with white tubes.

The tubes were inhabited

by a new species
of polychaete worm

that was exposed
to temperatures

as high as
80 degrees centigrade.

No other animal on Earth
was known to tolerate

such high temperatures,
so the scientists called

these creatures
"Pompeii worms."

But this was just
the beginning.

Nearby, there were chimneys
completely covered

by whole communities
of different organisms.

The bottom of the vent was
encrusted with large mussels.

There were swarms
of white crabs,

and most spectacular of all,
dominating the chimney

were hundreds of
bright-red tube worms,

each 2 meters long
and 4 centimeters wide.

Until these creatures
were discovered,

all life on Earth was thought
to be dependent on the sun.

But here, in the complete
darkness of the deep,

they had discovered
a rich density of life

that clearly derived no energy
from the sun.

So, what do they live on?

The answer was found within
the tube worms themselves.

They were packed full
of specialized bacteria

that are able to derive energy
from the sulfides

that are pouring
from the vents.

The worms' plumes
were bright red

with hemoglobin that carries
sulfides and oxygen

down to the bacteria.

These bacterial colonies are
the primary source of energy

for all the life
that lives here.

The mussels were
packed with them.

Just as green plants are
the basis of life for animals

living in the sun,

so these bacteria
and other microbes are

at the foot of the food chain on
which over 500 species depend.

Crabs and shrimps
feed off bacteria,

and even try to steal pieces
of tube worm plumes.

Since the vents were first
visited by biologists in 1979,

a new species has been described
every 10 days.

At the top
of the food chain,

fish that never stray far
from the vents.

But they,
or their descendants,

will have to move eventually,
for we now know

that individual vents
are rarely active

for more than
a few decades.

Such a density of life
living in such harsh conditions

in the middle of a vast
and otherwise barren

abyssal plain
astounded the biologists

who first saw it.

It seemed to them that
here was evidence of how

life on this planet,

which certainly started
in the sea,

might have begun.

Deep-sea submersibles
made an even more

extraordinary discovery
in 1990.

Over half a mile down,

at the bottom of
the Gulf of Mexico,

they came across what appeared
to be an underwater lake

over 20 meters long,
with its own sandy shore.

Around its edge, there even
seemed to be a tide line.

But this couldn't be,
of course.

This was underwater.

In fact, the lapping edge
was created by a thick soup

of salty brine far heavier
than the surrounding seawater.

And the sand
was made up of

hundreds of thousands
of mussels.

Once again, in the midst of
a totally barren seabed,

an extraordinarily rich
oasis of life

totally independent
of the sun's energy.

The source of energy this time
was not sulfides,

but methane bubbling out of
the sea bed.

And once again, the mussels
carried special bacteria

capable of fixing
the methane's energy.

Just like the hot vents,
a complete ecosystem

had developed
based on the bacteria.

There was an enormous variety
of completely new species--

shrimps,
weird squat lobsters,

and bright-red
polychaete worms.

These oases were called
"cold seeps,"

and were surprisingly similar
to the hot vents.

The geological processes
in the sea floor

that produce methane
also tend to result in

the release of
hydrogen sulfides.

It was hardly surprising,
then, when,

not far from
the brine pool,

they found tube worms.

Extensive fields
of tube worms

that stretch for
hundreds of meters.

This new species
also uses bacteria

to fix energy
from sulfides,

but it extracts them
directly from the ground.

Their beautiful gills
are only used

to supply oxygen
to the bacteria.

Amazingly, these tube worms
are over 200 years old.

While hot-vent tube worms
are thought to be

the fastest-growing
invertebrates in the sea,

these appear
to be far slower.

All the more reason
to protect your gills

from biting amphipods.

The energy sources exploited
by the hot-vent animals

may suddenly fail,
but here,

life can enjoy a more stable
geological future.

To discover, within 10 years,
two completely new ecosystems,

both totally independent
of the sun's energy,

has been quite
extraordinary.

So far, we have
explored just 1%

of the deep
ocean floor.

Who knows what is still
out there to be discovered?