All language subtitles for The.Blue.Planet.S01E06.Coral.Seas.1080p.AMZN.WEB-DL.DD+2.0.H.264-playWEB_track3_[eng]

In all the seas of the world,

the warm waters of the tropics
contain the richest

and the most colorful
communities...

...coral reefs.

They may seem like
underwater paradise,

but they are perpetual
battlegrounds for space.

Even the corals have
to fight for it.

In this crowded,
frenetic community,

every individual has
to find its own place,

its own way of surviving.

But none of these creatures
would be here,

if it were not for the coral.

A coral larva drifts
in the open sea,

floating in a soup
of young reef animals.

If just one of these
coral larvae settles

in a suitable spot and survives,
a new reef will be founded.

In just a few days,
the larva changes form

and becomes a polyp,
similar to a sea anemone.

Identical copies bud off
and, gradually,

a colony develops.

Each polyp surrounds itself
with a hard skeleton

and, from this solid base,
begins to grow.

It increases in length

by an impressive
15 centimeters a year.

This branching coral
is only two years old.

A mature reef can be thousands.

Corals provide the foundations

on which the entire
reef community relies.

Some organisms,
like the Christmas tree worms,

actually live within the coral.

Others climb out,
away from the reef,

to filter their food
from the water.

As the community grows,

intimate relationships
are formed

and different creatures become

increasingly dependent
on one another.

Even animals that spend much
of their time traveling

in the open ocean return
to the reef for a clean.

Corals reefs can be home
to astounding numbers of fish.

Here swim the smallest, and the
largest, fish in the sea.

Whale sharks are only visitors.

When currents bring
nutrient-rich water

up from the deep,
they come here to feed.

All these animals are here
because of the coral.

This extraordinary, complex maze
is built layer upon layer,

by millions and millions
of individual animals--

polyps.

Each polyp's flesh is supported
by a limestone skeleton.

Below the gut...

...is the place where most
of the growth occurs.

Here, the living tissue deposits

an intricate lattice
of limestone.

Beneath that,
the limestone skeleton is bare,

having been vacated
by the living coral tissues.

This is the hard structure

that forms the foundation
of the reef

and a single reef can extend
for many miles.

Coral reefs are only found
in the clear,

warm, shallow waters
of the tropics.

Sunlight is vital to them,
even though they're animals,

because inside their flesh

live millions of tiny,
single-celled algae--

plants.

And all plants need sunlight
to photosynthesize sugars.

98% of the food
that corals consume

is produced by the algae.

Without them,
the reef would not exist.

Like any other plant,

algae need just the right
amount of light--

not too much, not too little.

The corals regulate that

with pigments
that we can only see

when they are illuminated
by ultraviolet light.

Most corals, for protection,

spend the day withdrawn
into their stony fortresses,

but even then, they're not safe

from the jaws
of these butterflyfish.

At night,
the corals take in water,

expand their tentacles,
and emerge to feed.

They collect plankton.

Each tentacle has batteries
of stinging cells

which fire on contact.

Once the prey is caught,

it's passed down
to the polyp's mouth.

It's at night,
when the polyps are extended,

that they add to the limestone
foundations beneath them.

Inevitably, the corals begin
to overgrow each other,

and that means trouble.

When neighbors get too close,

they detect one another's
presence chemically.

The aggressor, on the right,
prepares for battle.

The polyps extrude their guts

and simply digest
their rivals alive.

A no-man's-land,
a band of white skeleton,

is the only evidence of the
night's border dispute.

Some corals are targeted
by yet more deadly predators.

Predators that can crawl
in search of their victims.

Crown-of-thorns starfish.

Poisonous,
invincible eating machines.

They also extrude their gut
and digest coral wholesale.

But some corals have help.

Small crabs living
within their branches

resist these onslaughts
and defend their home.

From beneath,
they launch an attack

on the vulnerable underside
of the starfish.

Even the crown-of-thorns
will retreat

from such a determined attack,
and this coral is left unharmed.

Success is related
to standing out, not fitting in.

The day you saw
something in me...

my whole life changed.

Cheyenne is a dangerous place.

I got nothing left to lose.

You know, you really
don't have to be so dramatic.

Whoo!

I'm moving up in the world.

So,
when's the show start?

Humphead parrotfish,

nearly a meter and a half
in length.

Their jaws are so powerful,
they can bite through rock.

When they descend to feed,
the reef itself is under threat.

They are indiscriminate feeders,

taking both rock
and coral, alike,

in their quest for algae.

These fish play a large part
in the erosion of the reef.

The rock and coral they swallow
emerges later as a fine sand.

On a single reef, they can
produce tons of it every year.

This soft sand forms

the tropical beaches
that we find so alluring.

Over time, the sand builds up
to form an island,

which is then colonized
by animals and plants.

Trees take root.

Birds arrive.

The guano from thousands
of terns

which have chosen to nest here
enriches the sandy soil,

which then can support
more plants.

But these terns,
like other seabirds,

depend on the ocean
for their food.

Below water, on the reef,

there is not only competition
for living space,

but a continual contest
between predators and prey.

It's the arms race
between them that,

over millions of years,

has produced today's
extraordinary diversity of form.

Jacks are one of the key
predators on the reef.

Their weapon is speed.

They seek silversides

and their defense is
to congregate

in confusing shoals
of shimmering silver.

The jacks try to deal with that

by herding the silversides
onto the reef.

Here, the jacks have
a better chance

of separating individual fish
from the shoal.

The jacks can now catch
the isolated individuals

with lightning attacks.

It's far safer to be hidden
on the reef itself,

within the tunnels of a sponge,
for example.

These tiny shrimp are no bigger
than grains of rice.

These shrimps are unique.

It's recently been discovered

that they have a highly
sophisticated social system,

similar to that of bees.

All members of the colony
are the offspring of one female.

She is the queen, and the only
one to produce eggs.

As in a colony of bees,

different individuals
are specialized

for particular tasks.

Some are guards, and are armed

with particularly large
and powerful claws.

They are on watch at all times,
ready to tackle intruders.

A polychaete worm.

For it, a sponge is
an excellent hunting ground.

In such a maze of tunnels,

attack can come at any time,
from any quarter.

Once the guards are alerted,
the worm loses its advantage.

Better to retreat intact
than risk serious injury.

The sponge not only makes
a safe home for the shrimps,

it also supplies them with food,

so that they never need
venture outside.

An establishment that provides
for all their needs

is clearly well worth defending.

Just as shrimps
guard their home,

other animals defend
their hunting grounds.

Glassfish make tempting prey
for the red-mouthed grouper.

Its strategy is
to swim slowly amongst them,

until they no longer see it
as a threat.

There are other fish here, too.

Lionfish are ambush predators,

taking their time and watching
for the right moment.

But there isn't room here
for two predators.

The grouper, braving the
lionfish's poisonous spines,

tries to evict its rival.

But lionfish are persistent.

This grouper spent many hours

simply defending
his hunting patch.

Some animals prefer to avoid
conflict whenever possible.

These harlequin shrimp,
having captured a starfish,

are taking it back
to a safe house

beyond the reach
of competitors and danger.

The problem with starfish is

that they have minds
of their own

and five large, sticky arms.

By the time the shrimps
have prized off one arm,

another has reattached itself.

Only by maneuvering the starfish
onto its back

can they have any hope
of gaining the advantage.

Even so, getting it back home
is a major undertaking.

The starfish is now
a living larder.

If the shrimps can hang onto it,

it will feed them
for days to come.

The top of the reef
is usually covered

by a thin layer of green algae,
another living larder,

and many fish depend on it.

Powder blue tangs
defend their right

to graze on a particular patch,

but, for a larder
as well-stocked as this,

there is always competition.

When a shoal of convict tangs
decide to graze,

little can stop them.

The powder blue tangs try
to keep them off...

...but they are overwhelmed
by sheer numbers.

The territory is stripped
of algae in minutes.

The blue tangs appear to be
fighting a losing battle.

But, eventually, they begin
to get the upper hand.

They persist with their attacks

until the marauders
are well on their way.

When night falls,

some very strange creatures
creep out of crevices

and crawl over the reef.

This moving bush is an animal,

a basket star,

which spreads out its arms
to catch the night's plankton.

The reef becomes
uncannily tranquil.

Fish retire, hiding themselves
where they can.

Marbled rays come out to hunt
for prey buried in the sand,

using electro-receptors
to scan the seabed.

Their activity attracts sharks.

Whitetips.

At night,
when vision is of little use,

sharks have a real advantage.

They can still use both smell
and electro-reception

to track fish.

These sharks are also hunting

for fish concealed
within the reef.

Their slender shape enables them
to squeeze

through surprisingly
narrow gaps.

There is nowhere to hide.

Few animals are safe
during these feeding frenzies.

Night after night,

the reef animals are subjected
to these raids.

But life on the reef
is not just about food.

It's also about sex.

There are many different
breeding strategies,

but each is aimed at maximizing

the number of young
that will survive.

Every afternoon, for two months,

brown surgeonfish
can be seen streaming

across reefs in the Red Sea.

They all head
for the same place,

usually some prominent feature.

Here, they wait
for the light to fade.

Suddenly, females
within the group make a dash

away from the reef
to release their eggs.

They're immediately followed

by the quickest and closest
of the males,

all of whom are striving
to fertilize the eggs.

Inevitably, others come here
to feast on such easy food.

As the surgeonfish spawn,

fusiliers move in above
to eat the nutritious eggs.

These are just the first
of many predators

which will feed on the eggs
and developing larvae

as they drift in the ocean
during the next few weeks.

Other fish are less casual
about their eggs.

Banded pipefish stay close

to a small, chosen area
on the reef.

Every morning, at sunrise,

the female leaves
her sleeping site

and swims to find her partner.

For ten minutes or so,
they remain together,

reaffirming the bond that is
essential to their partnership.

They swim together
around his territory

in a simple greeting dance.

Throughout the summer,
when the female's eggs are ripe,

courtship begins in earnest
in the early morning.

It takes time
and, after about two hours,

they rise together
off the seabed,

entwining their bodies.

The male rubs himself
against the female,

stimulating her
to release her eggs.

And, now, swiftly,
the male takes them.

The eggs,
now stuck to his belly,

are patted down to ensure
that they stay there.

The female then leaves him.

But, every morning,
she will return

for a session
of synchronized swimming,

and so ensure that their bond
is maintained.

Ten days later,
under the cover of darkness,

the male shakes his body
and the young pipefish are born.

Only now are they independent
of their parents.

Since the male takes charge
of the eggs

as soon as they're laid,

the female can start immediately
producing the next batch.

Without his help,
the pair could only breed

every 20 days,
rather than every ten,

so, by sharing the work,
they're doubling the number

of young they can produce
in any one year.

A flamboyant cuttlefish.

Unlike most cuttlefish,

this one spends much
of its time walking,

rather than jetting
across the seabed.

This is a male.

He is using his colorful display
to try and seduce

the larger female,
who seems unimpressed.

Eventually, she concedes.

The final event,
the transfer of sperm,

is very quick.

A singing male humpback whale.

Humpbacks are only visitors
to the reef.

After a pregnancy
that lasted a whole year,

the females come here
to give birth

and suckle
their newly-born young.

Their investment in their single
offspring is considerable,

for each female
will continue to nurse it

for a further six to 12 months.

But the males are here to mate.

The lone males sing

to establish
their relative seniority.

The louder and longer the song,

the bigger and stronger
the singer.

The better the song,
the larger the male,

the more mating opportunities
he will get.

All these different mating
strategies have the same aim--

to ensure that the greatest
possible number of offspring

will live long enough
to breed themselves.

Corals also reproduce sexually,

but, being fixed to the seabed,
they can't move to find a mate.

Somehow, they must synchronize
their sexual activity,

and they do so using the rising
water temperatures of spring

and the phases of the Moon.

A few days after the full Moon,
in late spring,

when tidal currents are
at their weakest,

the corals
of the Great Barrier Reef

are ready to spawn.

Some corals are male,
and release clouds of sperm.

Nearby, a female
will be releasing eggs.

Other species of coral
are both male and female.

These release packages of eggs
already pre-wrapped in sperm.

Bundles of eggs and sperm float
to the surface,

to mix with others,
from further along the reef.

Each kind of coral
times its release

to a certain hour
on a certain night.

That maximizes the chances
of cross-fertilization.

The fertilized eggs drift
away from the reef.

The stormy season
brings real danger

to the animals of the reef.

Lobsters in the Caribbean
sense a change in the water.

The temperature drops,

and powerful ocean swells
disturb the sand.

Under the cover of darkness,

they emerge,
to run before the storm

and risk crossing
the exposed sand flats

to seek shelter in deeper water.

Every year
they make this journey.

From all over the reef,
lobsters come to join the march.

They conserve their energy

by travelling
in one another's slipstream.

And there is the added benefit
of safety in numbers.

By daybreak, they've reached
the edge of the deep reef,

and down they go.

For the rest
of the stormy season,

they will remain
in the shelter of deep water,

out of harm's way.

Sometimes,
during the stormy season,

a hurricane builds, and then,

the very structure of the reef
itself is under threat.

An entire reef can be destroyed
by just one big storm,

hundreds of years of growth,
gone, in a few hours.

Out in the ocean,
new life continues to develop.

In time, coral larvae
will return

to colonize the rubble

and a new reef will grow
on the wasteland.