The Blue Planet (2001): Season 1, Episode 6 - Coral Seas - full transcript
Coral reefs are the rainforests of the sea; fish compete for food, territory and mates within this oasis of life. Incredible time-lapse photography shows the dramatic formation of a coral reef, portraying its inhabitants and its ultimate destruction.
In all the seas of the world the warm
waters of the tropics contain the richest
and the most colourful communities
Coral reefs
They may seem like
underwater paradise,
but they are perpetual battle
grounds... 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 fifteen centimetres 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
travelling 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 are animals,
because inside their flesh live millions
of tiny single-celled algae - plants
And all plants need sunlight
to photosynthesise sugars
Ninety eight per cent 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 are not safe from
the jaws of these butterfly fish
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 neighbours 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
Humphead parrotfish - nearly a metre
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 tonnes 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 colonised
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 defence 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
specialised 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
And 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 redmouth 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 prised
off arm another has reattached itself
Only by manoeuvring 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 spread 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
White tips
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 maximising
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 fertilise 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 pipe fish 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 synchronised 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 pipe fish are born
Only now are they independent
of their parents
Since the male takes charge of
the eggs as soon as they are laid,
the female can start immediately
producing the next batch
Without his help, the pair could
only breed every twenty 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 colourful 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 twelve 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 synchronise 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 maximises the chances
of cross-fertilisation
The fertilised 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
f 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 colonise the rubble
and a new reef will
grow on the wasteland
waters of the tropics contain the richest
and the most colourful communities
Coral reefs
They may seem like
underwater paradise,
but they are perpetual battle
grounds... 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 fifteen centimetres 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
travelling 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 are animals,
because inside their flesh live millions
of tiny single-celled algae - plants
And all plants need sunlight
to photosynthesise sugars
Ninety eight per cent 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 are not safe from
the jaws of these butterfly fish
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 neighbours 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
Humphead parrotfish - nearly a metre
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 tonnes 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 colonised
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 defence 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
specialised 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
And 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 redmouth 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 prised
off arm another has reattached itself
Only by manoeuvring 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 spread 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
White tips
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 maximising
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 fertilise 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 pipe fish 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 synchronised 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 pipe fish are born
Only now are they independent
of their parents
Since the male takes charge of
the eggs as soon as they are laid,
the female can start immediately
producing the next batch
Without his help, the pair could
only breed every twenty 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 colourful 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 twelve 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 synchronise 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 maximises the chances
of cross-fertilisation
The fertilised 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
f 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 colonise the rubble
and a new reef will
grow on the wasteland