(gentle music)
Far, far away, in the midst of an immense
almost uncrossable ocean, the atolls of the Pacific
are like oases in the middle of a desert.
Each of these jewel boxes conceals
a special environment beneath these waters,
both powerful and delicate.
Teeming with life.
These environments beneath the surface include passageways
between two worlds, breaches in the crown of coral
which allow the lagoon to communicate with the ocean.
These underwater canyons are playgrounds
of astonishing behavior.
Synchronized with the phases of the moon,
thousands of fish which Polynesians called Manini
are engaged in the survival of their species,
they are about to reproduce.
Out of the billions of eggs ejected into the ocean
only a very few will become adults.
In order to survive, the young Manini will need to go
on an extraordinary journey and overcome multiple dangers.
The Polynesian atolls were born 72 million years ago
from volcanoes surging out of the depths.
Nothing remains of them, the volcanoes have disappeared.
What we see, what has emerged, was built by an animal.
Tirelessly drawn by the light, the coral constructs
its calcium carbonate skeleton.
(light, playful music)
Each volcano has become an atoll at surface level,
an oasis of coral.
A refuge for marine species isolated in the middle
of a gigantic oceanic desert.
Lost in the middle of the world's largest ocean,
the atolls are cradled by the elements.
They're jewel boxes of life,
of sparkling untouched nature in perpetual evolution.
Beneath the water, the moon's calendar is respected.
Thousands of Manini come together to reproduce.
From all around the lagoon, all at the same moment,
they converge on a particular point, the pass.
This is the doorway out to the ocean.
A launchpad towards open waters
each time that the lagoon empties out
as the moon attracts the ocean towards it.
The Manini have come in search of this outward current
through the pass.
They want to eject their offspring from the atoll
so that they can escape the lagoons numerous predators.
They stake everything upon the phenomenal quantity
of eggs which will be carried away.
While other species prefer to produce less
but protect them more.
(light, playful music)
Like the damselfish.
The male has his harem.
One after another, the females come and leave
their purple-colored eggs within the territory of the male
who immediately releases his semen over them.
For eight days, the male constantly watches
over them until they hatch.
By contrast, the Manini meet in open water
and form small groups.
One female for several males.
This time it's the female who has her harem.
(suspenseful music)
A sudden surge of energy rushes through the pass.
The females head for the surface where the current
is strongest and release millions of egg cells.
At the same time as each female, several males swim up
and release their semen in what appears to be
a communal synchronized orgasm.
Within these little white clouds of gametes,
egg cells and spermatozoa interact.
(serious music)
But no sooner fertilized, the eggs are coveted.
The white, protein-filled soup is served.
It's all taken just a few minutes.
Out of the billions of microscopic eggs set adrift
those which have avoided the predators
begin a long oceanic journey.
Carried away by the current, the eggs disappear
into a 4,000 meter deep blue desert.
Cell division begins at incredible speed.
A Manini is on the way to being born.
(mysterious music)
Like a star in the middle of the Milky Way,
the Manini fish is for the moment,
just a potential life in the midst of oblivion.
By the end of it's first night, the Manini has taken form.
It measures two millimeters long and clings to the yolk sac
from which it draws energy.
Incapable of steering itself, it goes with the flow.
During the first week of its existence,
the little Manini belongs to the great zooplankton family.
All around, it is accompanied by other fish,
crustacean and mollusc larvae.
Each night, to feed, the zooplankton migrates vertically.
Going from the depths of the ocean to the surface.
It mainly feeds on drifting micro-algae
which depend upon light.
All these larvae look like aliens.
It's the strangest of worlds.
Unimaginable and yet at the origin of everything.
In the depths of the ocean
hides the world's biggest nursery.
(gentle music)
The little Manini is now 10 days old.
The embryo has become a larvae
with no further need for a yolk sac.
Slowly, it becomes strong enough
to use its fins for steering.
Anything floating in the ocean provides protection.
Even a humble coconut can serve as a refuge.
(ominous music)
The oceanic white tip shark
is the undisputed master of the open waters.
For him, everything is of interest.
He is the ocean's cleaner and mainly feeds
on the carcasses of dead animals.
Solitary and capable of going without food without weeks,
his metabolism is perfectly adapted to this food shortage.
In the end, he finds neither the coconut
nor the little Manini of interest.
(light music)
After seven to eight weeks of wandering around the ocean
the body of the little Manini changes.
Its method of subsistence and its camouflage
will soon no longer be adapted to oceanic life.
It's time for him to find an atoll
in which to settle definitively.
So he brings in to use a new sense
which he's just acquired, smell.
The atolls send out an olfactory flux for tens of kilometers
around them which act as a compass for the Manini larvae.
Along the way, it might cross the migratory route
of certain whales.
A female and her calf approach the atolls.
(gentle music)
Each year, Polynesia is frequented by whales
coming north from the Antarctic,
where they've stuffed themselves with shrimps.
They come in search of the warmth of the subtropical waters
for a few months, long enough to calve or mate.
(whales singing)
In any case, the severity of the southern winter
would be too much for them.
Breathing the extremely cold air could kill them.
The calf was born just a few weeks ago.
It will remain with its mother for more than a year,
drink its fill of her milk
and grow by 50 to 100 kilos a day.
The clement conditions of the Polynesian water
are also suitable for a fundamental apprenticeship.
The calf needs to learn to swim for a long time
in preparation for the return journey to the cold waters
of the Antarctic, which abound in food.
Each day, the mother takes it on long swims
around the atolls, punctuated by rest periods
for feeding and socializing.
An atoll is a refuge for both mothers and babies
and they know perfectly well how to navigate the passes
to keep out of the way of the oceans'
great marauding predators such as tiger sharks,
white tipped sharks and killer whales.
To avoid being spotted, the calf and it's mother
have developed whispering.
This means of communication, entails physical contact
and strengthens the maternal bond.
The calf is a baby of just a few weeks
and needs reassurance.
It hardly knows how to handle its buoyancy
and its mother serves as a buffer
to stop it rising to the surface.
54 days after its birth, the little Manini
comes to the end of its great ocean journey.
(light music)
The noise of the waves and the crackling of the reef
help it to find the outer rim of the atoll.
Behind this coral barrier lies shelter, a house
and fellow creatures.
But the hardest is yet to come.
Its small size allows it to easily pass the reef
by surfing on the waves around the atoll.
These breakers are provoked by contact
between the ocean swell and the coral rim at surface level.
This mixture of fresh water from the ocean, foam and light
is ideal for the development of coral.
(light, playful music)
Over this barrier, some of this swell enters the lagoon.
This is the principle means of water refreshment
and is vital for those living within.
It's through these hundreds of passages
a few centimeters deep and with no concern
for their turbulence that the Manini has chosen to enter.
It's the most dangerous moment of its life.
The moment when the vast majority of its fellow creatures
will be devoured by the fish of the reef.
To increase its chances of passing unnoticed,
the little Manini waits for a specific moment.
Once again, it is the moon which dictates the timing.
It is the moment when it is invisible
and the night is at its darkest that the operation
of slipping discreetly through the reef will begin.
Disappearing into the obscurity is a means of escaping
the predators which largely hunt by sight.
Made it, it's in the lagoon.
This new environment, not very deep, warmer,
of a calmer nature, allows it to complete its metamorphosis
and so it is that the larvae becomes a juvenile
in just a few hours.
It's still translucent body gives a hint
of the internal cartilage.
The little Manini is on the lookout
for its first hiding place and discovers all around
the world into which it was born.
(light, playful music)
Hierarchic.
Organized.
Inhabited.
The behavior of the parrot fish
when it sleeps is rather strange.
It hides itself away in a cocoon of mucus
which it constructs for itself,
thereby disguising its smell and its movements.
This is sufficient for it to remain undetected
by the predators of the night.
Here, at every level there is a species,
a community, an individual.
They sleep, they hide or they hunt.
While the moon influences the major biological cycles,
it is the sun which governs daily activities.
(mysterious music)
With its rays, the sun sets off photosynthesis.
Even underwater and especially when it's not very deep.
This light nourishes the algae which find in coral
an ideal structure for taking root.
But certain species stifle and kill coral.
Fortunately the fish in the lagoon nibble away
at these algae and stop them proliferating.
(gentle music)
Everything is connected in an atoll
and everything balances out to provide a habitat
and a biotope which has been regulating itself
for more than 70 million years.
In the kingdom of fish, the atoll has visitors.
The turtle is a reptile capable
of holding its breath for 20 minutes.
(light, playful music)
It is also a great traveler onto which small species
can cling, it is therefore instrumental
in dispersion around the ocean.
A large consumer of jellyfish when out in open water
the turtle comes to the islands for a change of diet.
It too feeds on the algae,
but it's on the lookout for zooxanthellae,
algae which are vital for coral
and which are contained in each polyp.
It interferes with the work of the herbivorous fish,
but not too much.
The turtle lives alone,
surrounded by the legions of grazer fish.
(gentle music)
The young Manini has tasted its first algae.
It too has become a herbivore and will remain so for life.
This change of diet marks the end of its metamorphosis.
In the space of a single night,
its striped robe has appeared.
This camouflage outfit is designed to trick the adversary.
The eye is disguised by a stripe so that predators
can't distinguish between the front and the back
and thereby anticipate the direction of flight.
(dramatic music)
Nearby the triggerfish marks out its territory
which it is quite capable of defending.
It moves some coral and sends the sand flying
while building its nest.
Its eggs will be placed here and ferociously guarded.
(gentle music)
The angel of the lagoon, the manta ray,
is in the habit of circling the same block of coral
in the hope of a mutually profitable deal.
It offers a good meal in exchange for cleaning services.
Cleaner fish come to feed on its dead skin and parasites.
All the fish of the lagoon are familiar
with these little cleaner wrasses which are renowned
for providing top quality service.
You just have to turn up at the cleaning station.
With such attentiveness, even the most fearsome
become docile and present an impressive row of teeth.
In addition to this organized routine,
there are also the major events.
The one being prepared by the groupers of the atoll
is probably the most important one of the year.
Tens of thousands of groupers, which are usually solitary,
meet up in the pass to reproduce.
They come from all over the atoll, always to the same spot
some having traveled almost 100 kilometers.
They only do this once a year and all at the same moment.
How do they achieve this synchronization?
Once again, it is the moon which gives the signal.
Sometime around the winter solstice when the nights
are at their longest.
On arriving in the unique setting of the pass,
a few days ahead of the time of reproduction,
the young groupers do not yet have sexual organs
neither male nor female.
And yet, they are mature.
It is upon meeting up that the final transformation
takes place, according to the needs
of the survival of the species.
For the moment, they need to share
a tiny territory at the exit of the pass.
This number of fish in such a small area
causes upheaval in the daily life of the atoll.
But all these fish constitute an animal society
with tried and tested codes, which make the atoll
one of the most balanced of ecosystems.
Feeding, disinfection, reproduction.
These are the fundamental activities in the lagoon.
The mantas also reproduce, but not like the groupers.
There's no great assembly,
but instead, fleeting couples are formed.
The eggs are contained in the belly of the female
and are fertilized by the male during mating.
The male seizes one of the female's fins in its mouth.
These preliminaries are imperative if the belly to belly
position is to be achieved and sustained during the act.
The fertilized eggs in the uterus of the female
develop inside her body for a year before hatching,
as is the case with most sharks.
(ominous music)
Except for sharks, mating is more painful.
As with manta rays, the male grips the female by the fin
with its mouth, holding her in a certain position.
Fortunately, her skin is twice as thick
as that of the male, making the embracing bite bearable.
(tense music)
In this position, the male produces
one of its two reproductive organs
and inserts it in the cloaca of the female.
Depending on the species of shark, the fertilized eggs
are either released by the female,
or remain sheltered in the mother's belly
until giving birth to several little shark pups.
Sometimes as many as eight in the case of nurse sharks.
The atoll breathes.
Fresh water is provided by the swell
coming in over the reef.
This is the inhalation.
(gentle music)
Exhalation is through the pass
when the lagoon is emptied out by the tide.
This is how the water of an atoll is refreshed.
A constant exchange between the ocean and the lagoon
which is filled up over its crown
and emptied through its passes.
The encounter between the swell of the open water
and the current coming out of the pass forms waves.
This is an amazing playground for dolphins,
a place where they come to socialize.
A colony of Tursiops dolphins has set up home in this pass.
A little melon-headed dolphin with its rounded nose
has also made a stopover in the pass and mimics
the jumping of the longer nosed resident species.
(dolphins calling)
This proximity and indeed complicity,
demonstrates the capacity of dolphins
to have much more elaborate behavior than fish.
The young melon-headed dolphin, probably orphaned,
appears lost and doesn't dare go back to open waters.
It remains attached to the Tursiops community
and even seems to be in search of adult protection.
After a few days, the young dolphin becomes accepted
and resides henceforth in the bosom of the Tursiops group.
It's been taken in charge by an adoptive mother.
To advance its education, she demonstrates a new game.
While it watches, she cleans her muzzle
on the silky surface of a sponge attached to the coral.
When the water flows out of the lagoon
towards the great expanse, the current leaving the pass
carries particles and biological debris with it.
The waters are rich and bring the fish
an abundant source of food.
Arriving from further afield, the eagle ray
is not one of the pass's residents, but often glides through
as if taking advantage of the refreshing current.
(gentle music)
At the same time, it skims the bed,
unearthing small crustaceans to feed on.
From its muzzle, it fires a jet of water
which lifts the sand and flushes out its prey,
which it sucks in and crushes, thanks to several rows
of powerful teeth, capable of cracking carapaces and shells.
Each species has good reasons for frequenting the pass.
Despite the diversity and the density,
there is little hunting.
Everything seems peaceful.
The nourishing current alone is sufficient
to satisfy all these animals.
(playful music)
So there are those who come to feed in the pass
and those who set up home.
Like the inseparable goby and blind shrimp.
Like a true drudge, the shrimp hollows out a gallery.
It spends its time doing maintenance on a hole
which tends to cave in.
As for the goby, eyes wide open, it keeps a lookout.
There is constant contact between the two
thanks to the shrimp's antennae which strokes the goby.
In case of emergency, the fish makes use of the gallery
while warning the shrimp of the danger.
(suspenseful music)
The pass is full of these subtle associations.
(light music)
The yellow tropic fish swims in synchronization
with the trigger fish.
What is behind this strange behavior?
Does it stay hidden from its prey to increase surprise?
Or is it taking advantage of the hunting skills
of the trigger fish which flushes out small animals?
(mysterious music)
In the passes, the regular exchanges between the lagoon
and the ocean, attract a good number of species.
These are the most crowded places in the atolls
and at the end of the food chain is the shark.
(ominous music)
Arriving from open waters, the hammerhead shark
and the tiger shark sometimes make incursions here.
They are gray shark eaters.
During the day, the gray sharks rest and take advantage
of the current to breathe effortlessly, they don't hunt.
(gentle music)
The southern pass of the Fakarava atoll
probably has the largest gray shark population
in all of Polynesia.
This is linked to the current,
which being neither too strong nor too weak
is ideal for the expansive development of coral.
Consequently, fish find enough food and hiding places
to be able to live here in large numbers
and most importantly, this is where they come to reproduce.
It's the turn of the groupers.
For four weeks they've been gathering here
from all over the atoll.
They have literally invaded the pass and now number
more than 18,000, packed in, one against the other.
They need to mark out their territory, impose their law
and form their harems, ready for reproduction day.
The males provoke each other, parade about,
intimidate and fight.
Order is progressively established,
everyone holds their breath facing the current,
waiting for the big day.
But certain groupers bear severe wounds.
Their in-fighting alone cannot be responsible
for the state they're in.
In reality, their crowding together has attracted
much bigger predators.
The pass has become a gigantic larder for sharks.
(ominous music)
It is now two days since the young Manini
arrived at the atoll.
It is now a miniature adult with stripes
which allow it to melt into the background.
But it isn't particularly at ease
in the middle of this teeming atoll.
Each day, the half light gives the signal for a radical
behavioral transformation in the pass.
(ominous music)
In this bottleneck trembling with life,
the diurnal fish disappear into the holes in the coral.
They know that the predatorial instincts
of the sharks are growing.
At night, they take the upper hand over all the fish
which become potential prey.
The paradox of this animal with the fearsome jaw
is that it's a very bad hunter.
On its own it has very little chance of catching fish,
apart from those which are sick or weakened.
This shark, which hunts exclusively at night,
is only efficient when in a group.
Its wave captors lining the length of its body
are particularly sensitive and able to detect
the slightest of movements.
At night, these captors which are more reactive
than those of a fish, give it an advantage over its prey
which is caught by surprise.
At the moment of the attack, over the last centimeters,
other captors contained in its muzzle come into play
but this isn't always sufficient.
(tense music)
In the general panic, the poor fish
which manages to escape the first time is pursued.
Hope is running out.
Harassment from the group, over-excited by the stress
of the fleeing fish, sound the death knell.
Unless the prey can manage to reach the fortress of coral
without delay, but even then, in their frenzy,
the sharks are capable of breaking in.
Each night brings its nightmare for the groupers
as for many other fish in the pass.
At daybreak, they come out again
and take back possession of their territory.
The females have had about enough of their bellyful of eggs.
They haven't fed for weeks.
They're harassed by the males, who have only one thing
in mind, being the first to enjoy synchronized contact
with a female at the moment of laying.
At the moment when the females release their eggs
the males eject a cloud of spermatozoa.
This immediately provokes a rush of fusilier fish.
No sooner out of the belly of the groupers,
the gametes are swallowed.
A lightning choreography.
Fireworks of fertility.
That pass has become the stage of a fight for life.
The islands are colonized by what the ocean lets drift.
Often dead wood, sometimes a grain.
The island is essentially mineral.
It is a sand bank formed from coral wrenched from the reef.
It's not simple for life to prosper here.
Out of the water, aggression from the elements
makes things difficult.
Beneath the water, life is more gentle.
The situation is more ripe for colonization.
What's more, that's where it all started.
The little Manini has been living for two weeks in the atoll
and it's prisoner-like striped clothing is now complete.
It had one chance in a million of becoming an adult.
It avoided all the snares of the open water,
of the reef and of the pass.
It is a young Manini capable of accompanying
its fellow creatures towards the point of reproduction.
It will have to wait another year before reaching maturity.
In the meantime, it observes the others of its kind.
If it's to reproduce, it will need to learn
to escape from sharks and other opportunist predators.
In a certain way, outmaneuver death in order to give life.
These sublime and untouched atolls are always regarded
as an achievement, as a journey's end.
The nearest continent is thousands of kilometers away.
But this isolation doesn't make these jewel boxes
any less vulnerable.
An abnormal variation in ocean temperature
or a brutal rise in water level
would get the better of these lagoons and their fish.
This is why the balance
of these far-flung places remains precarious.
As with the journeys of the first Polynesians
and their pirogues, guided by the stars
and similarly pushed by the currents.
At the time, there was no fear that these men
might change nature.
They too were lucky to come upon the atolls.