Original subtitles

Lakes are living creatures.

These precious reserves of water live and die

according to distinct natural cycles.

Their peaceful waters seem dormant,

yet them teem with mysterious life.

Lakes only reveal themselves to the men and women

who take time to patiently linger beside their shores.

Together, we are going to discover their secrets.

The rhythm of an entire country, Cambodia,

follows the cycle of this lake.

At the heart of the Khemarak Kingdom,

this huge and bounteous lake forms

the greatest reserve of fresh water

in Southeast Asia.

It's name, Tonle Sap.

The name means fresh water river,

in reference to the Mekong,

the river that provides most of it's water.

Tonle Sap is home to one of the

greatest flooded forests on Earth,

a fabulous natural sanctuary where migrating birds

from all over Asia stop to feed.

Of all the lakes in Asia,

Tonle Sap is probably the most bounteous.

More than three million Cambodians depend

on it's fish filled waters.

But it's also a capricious lake,

it's water disappearing and then reappearing

in rhythm with the seasons.

As vast as the sea during the wet season,

the lake becomes a muddy pond in the dry season.

The fortunes of the planet's last great food larder lake

depend entirely on the cyclical return of it's waters.

More than a million people live in the 90 villages

that surround Tonle Sap.

Their lives synchronized to the lake's own rhythm.

It shelters, transports, and feeds all these people

who have adapted to the water born life

the Tonle Sap imposes on them.

To the north of the lake,

in the floating villiage of Prek Toal,

there lives a fisherman who has never left Tonle Sap.

Kuy Ann lives in harmony with the lake,

it's cycles governing every moment of his existence.

I love this lake,

and especially the way we live here

in this floating village.

Living here is a question of what you're used to.

Everything's made easy for me.

Bathing, getting around by boat,

I don't feel comfortable on dry land.

I can't ride a bike or a motor bike.

Kuy Ann lives in a floating house,

tends a floating garden,

and spends most of his life on the water.

The bamboo which supports the floating garden,

has to be replaced every year.

It's a chore which Kuy Ann carries out

like a veritable mer-man.

I was born on the lake.

We're fishermen here from father to son.

I know Tonle Sap by heart,

and all the fish which live in it,

including those which hide in the mud.

I also know the wind, the directions it blows,

the mass movements of the fish.

Kuy Ann understands that it is the people

who must adapt to the movements of the lake

and not the other way around.

For Tonle Sap is an ever changing ecosystem,

which leads a double life.

The lake empties and fills up again

according to a seasonal cycle which it imposes

on all lakeside life.

When the waters have gone,

the lake becomes a veritable swamp.

When they return, the lake spreads out again,

no respecter of boundaries.

The entire lakeside ecosystem

depends on this primordial aquatic cycle.

Every year between May and June, the monsoon returns.

Torrential rains batter the whole of Southeast Asia

during this period.

The water brought by the rain is swollen by melt water

from the Himalayan glaciers.

The water gushes down the mountain slopes,

and the muddy torrents thus created converge

on the immense drainage basin of the Mekong.

Then occurs a unique hydro logical phenomenon,

the flow of water reverses.

Whereas the water usually flows from the Tonle Sap river

towards the Mekong,

all of the sudden this goes into reverse.

The pressure of the Mekong in spade becomes so strong,

that it flows back up in the direction of the lake.

The direction of the Tonle Sap river's current is reversed,

and the Mekong's muddy water fills the lake.

This is when the living heart of Cambodia

beats its strongest.

The lake is swollen by the river, and overflows,

flooding the land all around.

The surface area of the water increases

five fold at this time.

Water rich with sediment, floods some

15,000 square kilometers.

At this time, Tonle Sap's ecosystem undergoes

a radical transformation.

The rice fields absorb the excess water,

and the vegetation, stimulated by the alluvial deposits,

enjoys a new spurt of growth.

For several months the level of the lake keeps rising,

from a low of barely 50 centimeters,

to over eight meters.

A new equilibrium settles between the Earth and the water,

but it's a fragile one.

Tonle Sap is a lake about which much is still unknown,

despite years of scientific study.

Sylyvann Borei, a scientist from the World Fish Center,

has traveled here from Phnom Penh, the capital,

to carry out his seasonal report

on the lakes aquatic resources.

He depends on Kuy Ann to help him collect his samples.

It's impossible to identify the fish

in their natural habitat,

because the lake's water is far too muddy.

The only possibility is to capture the fish,

and place them in a custom built aquarium.

There has been little research done on the fish of Tonle Sap

and yet they are vital importance to Cambodia.

They provide a third of the protein

consumed by the population.

But no one knows just exactly how long

the lake will be able to go on providing fish

in such quantity.

For Tonle Sap and its fauna,

the intensity of the monsoon is a decisive factor.

Was the flood extensive enough this year?

Was it sufficiently high in nutrients?

The good health of the fish's habitats

and therefor the abundance of future catches

depend on this muddy water.

Kuy Ann has spread his net

between the tops of submerged trees.

He knows that these flooded trees,

rich with insects and berries,

shelter many species of fish.

Straight away, Sylyvann starts to recognize

certain species he was hoping to catch specimens of.

See what we have here.

That's a , a Panga.

And is that a Channa?

Yes, it's a Striped Snakehead.

- Here in the Tonle Sap we have like

three main group of species.

So the first one is the Traera,

which belongs to the Blackfish Family.

They have small scales,

sometimes the scale is kinda absent.

Adaptation is very strong,

they can live in the water which is less oxygenated

during dry season.

Another fish is called Tripera,

that belongs to the Whitefish family.

You see the color is kind of silvery and light,

they need clean water.

So in dry season they usually move

up to 1,000 kilometer away to find food from upstream.

I'm gonna catch another fish, the.

That from the gray family.

The adaptation is fairly strong,

that is why they do not have to migrate too far

away from the lake to feed and to breed

during rainy season.

So usually they just go to the small tributary

along the lake.

It seems that we do not have the catfish

in the tank right now,

but we're gonna go and find out where it is.

There's one important species still missing,

Clarias batrachus, the walking catfish.

It's a remarkable creature whose no show could be a bad sign

for the lakeside ecosystem.

Although Sylyvann doesn't feel very comfortable

on the water,

he still has no hesitation about getting out there

in this strange canoe come lifeboat contraption.

Threading through the branches of the trees

in search of the fish he hopes to catch.

The scientist's determination finally pays off.

- This is a walking catfish,

it can definitely walk in the mud during dry season.

It's a fish one must handle with caution,

because of the stings in it's fins.

Once the walking catfish,

one of the lakes rare sedentary species, has been caught,

the collection is complete.

The lake is a full compliment of

black, white, and gray fish species.

Thanks to the flood,

this year again there'll be good fishing.

During the eight high water months,

the inhabitants of Tonle Sap barely see dry land.

The villages canals become clogged

with the fishermen's boats,

and fishing is once again the main activity.

All of local life takes place on the water.

They go to school by boat,

move merchandise around by boat,

there are even boats with ingenious hanging gardens

for growing vegetables.

The majority of those who fish Tonle Sap

live on the water.

Some opt for a fixed home with a house raised on stilts,

which remains dry all year round.

But in Prek Toal, most of the families have gone

for the originally Vietnamese option

of a floating habitat,

made of boats with rafts moored between them.

Just like the people who live in them,

these boat houses adapt to every little change

that occurs on Tonle Sap.

They follow its movements,

traveling up and down in accordance

with the lake's own rhythm.

Kuy Ann has always lived in just such a house.

Like many other Tonle Sap fishermen,

he raises Siamese Crocodiles in floating cages.

Previously present in great numbers in the lake,

these creatures are now rare in the wild.

In a few months, once these have grown big enough,

the best specimens will be sold in Vietnam or Thailand

where their skin will be used to make bags and shoes.

Kuy Ann's favorite lodgers are not his crocodiles however,

but farmed fish of a quite unusual size.

He wouldn't part with these for any price.

They're Panga, giant catfish,

which can weigh as much as 50 to 70 kilos.

These are about five years old.

All around here, in fact all around the lake,

I'm the only person to have any.

I'm very proud of them and take good care of them.

Once they're big enough,

these fish can fetch a good price.

But I'm growing them for their symbolic power.

I want to save them for the younger generation.

Tonle Sap is very important

to everyone in Cambodia.

It feeds the people, it's fish provide us with protein,

and we can cook all sorts of different dishes with them.

We sell our fish in the neighboring countries

as well as in Cambodia itself.

The entire population of the country

depends on the lake.

The water goes on rising until October.

By the time it reaches the highest level,

only the flooded forest treetops can still be seen.

The fish then disperse throughout the now immense lake,

and the nomad fisher families,

have no other choice but to accompany their migration.

We have to find a spot

where the water isn't so deep,

and where there are more fish.

Yes, there are too few fish here now.

We have to move.

We'll get ready to move

as quickly as we can.

In search of a more promising

fishing spot,

Folk See's family prepare to weigh anchor,

taking with them everything they own.

The fisherman and his son lash together

the house, the fish tanks, and the precious floating garden.

Towed by a tiny powered canoe,

the impressive convoy gets underway.

It's the right time to be moving

because the storms will soon come,

and getting around the lake will become

a dangerous undertaking.

The fishing families move their homes in this way

up to 12 times a year,

going wherever the migrating fish lead them.

This peripatetic existence is the price these families pay

in order to live in constant harmony

with the resources of the lake.

On an assignment for the World Conservation Society,

biologist Simon Mahood, sets out from Kampong Phluk

for the Flooded Forest,

the most unusual ecosystem

throughout the whole of Tonle Sap.

Covered in water for several months of the year,

this remarkable forest is able to survive

thanks to vegetation equally well adapted

to life under water as in the air.

It's an ecosystem that used to cover 10,000 square meters,

but now only a fraction of that still remains.

Making it all the more precious.

- The Tonle Sap supports a huge area of flooded forest,

about 300 kilometers square.

There are only four or five species of trees

able to survive these harsh conditions

of the drought and the flood every year.

At this period of the year,

the most interesting specimens

are to be found under the water.

Have you got one?

Yes, yes this is it.

This is the only tree that photosynthesizes

under water in the Tonle Sap.

Barringtonia acutangula , this is incredible.

This tree doesn't loose it's leaves,

even when it is inundated by water

for five whole months.

The fish swim amongst it's branches,

and they take food off the leaves.

The tree also produces flowers and fruits under water,

and so the flowers are pollinated by fish,

and the seeds are dispersed by fish also.

It's amazing.

The Barringtonia is incredibly important for local people.

It has shiny, waxy leaves,

local people pick them and put them in salads and soups.

The roots of the tree have also traditionally been used

to treat Malaria and other diseases.

Most of the trees around us,

and indeed most of the trees in the Tonle Sap,

are the Barringtonia trees.

But this tree close to us here

this is the.

This is an incredibly important tree for the water birds.

This tree grows very tall,

it makes a safe place to rear their young

and it's the reason why there are so many

storks, pelicans, and otters in the Tonle Sap.

This nurturing forest, which is as much

a nursery for fish as it is for birds,

is an incredible boon for lakeside biodiversity.

Wet forests like this are very rare in Asia today.

So important and unique is this fresh water mangrove swamp,

that UNESCO classified it as a biosphere reserve in 1997.

The birds know that during the high water period,

the treetops provide a safe haven.

During this season, ornithologist Sun Wisal,

visits his feathered proteges almost every day.

We'll try over there.

Over there.

The Prek Toal reserve is a bird sanctuary

born of a collaboration between

French Association Osmose,

and the Wildlife Conservation Society.

Hello.

The park rangers

are almost all former poachers.

Perched high in the Barringtonia treetops

like the birds they observe,

Sun Wisal's team keep 30 or so platforms

permanently manned.

Okay, let's look at the data.

A zero means a youngster that survived to adulthood,

is that right?

Yes.

So in all that makes 4,012 birds,

and 400 nests.

The constant surveillance of the nests

has considerably reduced the poaching of the eggs.

In order to get a closer look,

Sun Wisal has had special observation platforms made.

The raft has to be maneuvered by oar,

and positioned with extreme care.

And then there might be a long wait

of several hours before the birds

dare to return to their nests.

It's Tonle Sap's hydro logical cycle,

which gives the whole region such a rich biodiversity.

The fish get all the food they need in the lake.

And it's because of the fish that the birds nest

and lay their eggs here,

because of the abundance of fish.

The lake attracts certain species of birds

that are going extinct all over Southeast Asia.

They spend six months here,

time enough for them to reproduce.

That's the reserve of the Black Bellied Darters,

we also call them Snake Birds.

They are a species threatened with extinction

around the world.

In 2002, there were only 250 couples left.

But today in 2014,

their population has increased to 7,000 couples,

and the number is still growing.

The reserve is unique in Southeast Asia.

There are so many of them that they

completely cover the trees, it's amazing.

But this constant surveillance of the birds

is not enough.

Some effort must be made to involve the local people

in their protection.

Sun Wisal knows that school children

from the surrounding villages,

will make excellent spokespersons for his cause.

What does the red poster show?

The birds of Tonle Sap

that are under threat.

Who can show me the Egret?

Have you ever seen one?

Or eaten one?

No.

By initiating the lakes children

into the practice of bird watching,

Sun Wisal hopes to make them understand the importance

of preserving Tonle Sap's rare species.

Darters, Storks, Ibis's, and Herons

will soon take to the skies once again

on their migratory journey.

They wont return to Prek Toal for several months.

Every year dozens of bird species,

including some that are now extremely rare,

find a precious refuge here.

At the end of October when the water level

is at its highest,

the lake is covered with water Hyacinths.

This invasive plant, originally from Amazonia,

chokes Tonle Sap.

It makes boating and fishing difficult,

and uses up a lot of the lake's precious oxygen.

The women of Prek Toal form small teams

which do their best to free the lake

from the plant's strangle hold.

They scythe the Hyacinths by the armful.

Their roots are used as compost,

the flowers are eaten,

and the stems are plaited to make hammocks.

This way the women of Prek Toal

have turned this yearly scourge

into a useful resource.

When the water Hyacinths are proliferating,

and the snakes are swimming at the surface,

the water has reached its peak.

For Kuy Ann, it's time to start a new type of fishing.

This one's been dead a while.

The Hyacinth groves are the preferred

habitat of the water snakes

and the small fish on which they feed.

These reptiles, most of which are not poisonous,

have no chance of escaping the nets

placed by Kuy Ann during the night.

In only a few hours, he manages to catch dozens

and he prefers them still alive.

Throw it in the tank,

that one's still alive.

The thousands of snakes

caught daily in the Tonle Sap,

are not destined for the fishermen's dining tables,

but for feeding their precious crocodiles.

During this season, snake replaces fish

on the crocodile's menu.

Every year Tonle Sap's farmed crocodiles

consume millions of these snakes.

It's the most extensive concerted snake hunt

anywhere in the world.

In November, the water level starts to drop.

The phenomenon which began five months ago

now reverses and the flow of the water changes

for the second time.

Nature and people must once again

adapt to the changes forced on them by the lake.

The Mekong's flow is considerably diminished,

and the Tonle Sap river can finally resume its role

as an outlet.

The water flows once again from the lake to the river,

and Tonle Sap begins to empty out.

The beating heart of Cambodia contracts,

as its vital precious liquid pours away.

It's the beginning of a new period in the life of the lake,

the low water season.

The lake doesn't disappear entirely,

but in a few months its surface area

shrinks from 15,000 square kilometers,

to only 3,000.

It's a clear signal for the fish.

Faithful to their lake, the black fish

prepare to spend the dry season hidden in the mud.

The gray fish seek refuge in the smaller tributaries,

but the white fish, guided by instinct,

know that it is time to abandon the lake,

now become too small for them.

They leave the lake in which they grew up,

reach the Mekong, and then head up stream

to the falls further North.

But their voyage up stream is not without its dangers.

They have to get past the dice,

the formidable floating fisheries which bar their way.

This is where the Cambodian fishermen

are waiting for them.

On the dice, the fishing is quite miraculous,

with an enormous daily catch.

In all, over 15,000 tons of fish are caught here every year,

all thanks to Tonle Sap's incredible fecundity.

The most sought after species are sold in the local markets,

while the rest is made into prahok,

a fish paste which can be kept for months.

Only 20% of the fish manage to escape the nets,

but this appears to be enough for the migrating species

to reproduce.

As perserverant as salmon,

the escaped fish continue their journey

for 20 days and 20 nights

on towards the Laotian border.

Before them looms the final obstacle,

keeping them from their spawning beds,

the rapids at Cyf Andong.

Beyond these falls,

and the tumultuous waters of the Mekong's tributaries,

Tonle Sap's white fish finally reach their spawning beds.

At the next monsoon, their tiny young

will swim back down the Mekong,

so that they too can grow to adulthood

in the muddy water of the great lake.

The Mekong's falls are spectacular,

but very hard to get to.

It's a spot that Thai photgrapher, Suthep Kritsanavarin,

has become particularly fond of.

For the last 10 years, he's been coming back every year

to photograph the fishermen of the Mekong rapids.

Throughout the whole Mekong

they have special places for fishing.

One is in Tonle Sap in Cambodia,

and the other one is in Cyf Andong in Laos.

And the people use many special fishing techniques.

Here we can see the rapids

and the really strong waterfalls,

where they're trying to catch some of the fish.

Here, Cyf Andong is in the middle,

at least 200 species have to pass along this route

to the North.

Because he's willing to take the same risks

as the acrobatic fishermen,

Suthep has gained their trust

and been able to take his incredible photos.

In 2011, the fishermen of Cyf Andong,

finally managed to catch the mythical fish

they've been after for years.

The most important picture for me,

is the giant catfish that they caught

in the Soham channel.

So I was waiting for that shot

for two or three years.

When I saw it, I was really excited

because it was there in its natural environment.

I know it's really important because that is the one picture

that can show many things,

because there had been no evidence before

that these fish travel a very long way to Tonle Sap lake,

and then thousands of kilometers past here

to the North of Thailand to spawn.

The giant catfish is one of the last

representatives of a species that used to be found

in Tonle Sap.

Today only a few rare specimens,

still lives in the rapids of Cyf Andong.

In May, several months after the second reversal

of the water flow,

Tonle Sap has reached its lowest level.

Rice fields and roads reappear,

where before there was only water,

the mud which is omnipresent in this season,

is not considered a problem,

but a great treasure offered up by the lake.

The sediment brought by the flood is deposited everywhere.

This mixture of earth and water makes an ideal soil

in which to grow rice.

For the inhabitants of Tonle Sap,

a new life now begins.

Fishing becomes a secondary activity,

carried out by children and old men.

Yesterday's fishermen have put away their boats

and turned into farmers for a season.

There's no time to lose,

barely have the waters receded

before they're working the soil,

planting and then harvesting.

The few months before the next flood

are just enough to ensure the yearly rice harvest.

Kompong Phluk has emerged from the lake.

The usually water bound lake village

can now be walked through.

On either side of the village,

a narrow muddy channel is all that remains

of the great lake.

The elevated kamare houses

are now only accessible by ladder.

A few stubborn fishermen still apply their trade,

but all the others have already opted for life on the land.

Fishing biologists at the World Fish Center

Eric Baran has been carefully observing Tonle Sap

for almost 20 years.

In between his research missions on the Mekong,

the scientist regularly returns

to check the health of the lake.

It's a real pleasure for me to come back now,

because when we were here in August,

the water reached all the way up to the houses,

and now look at the difference.

You can see all the fishing apparatus,

the forest of wooden stilts.

They're taking this opportunity

to repair their fishing gear.

During the dry season,

the inhabitants of Kampong Phluk

devote a lot of time to the maintenance

of their fishing equipment.

Life on land kicks off again at the feet of the spider house

and kids relearn how to ride their bikes.

They play ball next to the prawns

spread out to dry on the ground.

On the very spot where a few months earlier

they were swimming.

Everyone makes the most of Tonle Sap's

low water season,

of the time and space it gives them

to carry out repairs on their homes, boats,

and fishing nets.

There are just over a million people

who really do depend on the water and the fishing.

These people consume over 40 kilograms

of fish each per year.

That comes out at 100 grams per person per day.

Which shows to what extent this lake

really does nourish an entire population.

From an ecological point of view,

it really is an exceptional lake.

The surface area changes five fold

and at it's maximum,

it is roughly the size or Corsica.

Then when it shrinks to its minimum,

it becomes extremely hard for the fish species

to survive because it's so shallow.

It goes from a depth of about eight meters,

to just one meter, or even half a meter.

The water gets very warm, and there's very little oxygen,

so there are few species that can survive.

Besides small fry and prawns,

which remain abundant,

the sedentary blackfish species

are still present in the lake.

To catch them, there's no need of a net,

a simple creole suffices.

In this season the flooded forest is one big quagmire.

To fish that don't migrate bury themselves into the mud,

where they're easy prey for as experienced

of fishermen as Kuy Ann.

I've caught a walking fish.

It's a fish that survives in the mud.

It's a really clever fish,

because it can adapt to both seasons.

It can get around and move over land like that.

The changes that the lake undergoes,

have led to the striped Shauna,

evolving the ability to move about on land

during the dry season.

The amazing fish, which has both gills

and a primitive lung, can breathe air

and uses its fins to walk out of the water.

Half aquatic, half terrestrial,

it really is a perfect symbol for the inhabitants

of Tonle Sap.

By stubbornly continuing to fish during the dry season,

Kuy Ann is something of an exception.

Most of the villagers devote themselves during these months

to their rice fields.

It's also in the rice fields

that most of Tonle Sap's water snakes take refuge.

This is where Neang Thy comes to hunt them.

Considered one of Cambodia's top reptile expert,

this scientist is here to study the effect

of the intensive hunting of the past few months

has had on these creatures.

- Oh this is a rainbow snake.

This is a species that's very common in Tonle Sap

and around Cambodia.

Tonle Sap is the place where you can find

the most water snakes,

but we don't know how many there are in the water.

Previous study recorded that four to seven million

water snakes have been hunted every year.

People around Tonle Sap they waste snake

to sell for the crocodile farm.

And because the crocodile farm is pleasing,

and they take water snake to feed the crocodile.

And most water snakes also collected for

local consumption, for skin,

for thread to neighboring country.

It's brought to China, it's brought to Thai,

it's brought to Vietnam.

People reported that they used to buy

50 kilogram from one place of water snake,

but they only get 15 kilogram instead.

That is seem to be decline around 30%.

Another iconic creature of the region,

the python, is today threatened with extinction,

which could have serious consequences

for the local human population.

Python very important

in sustaining a quota in the food chain,

because python control rodent.

Now because the python hunted out

and very rare now,

and why python is very rare,

rat a lot now increasing.

And when the rat increasing

they may eat peoples crop that

the use of rice production every year.

The uncontrollable proliferation

of rats and other pests,

could turn out to be a very serious consequence

of snakes disappearing from Tonle Sap.

At the height of the dry season,

Prek Toal village is unrecognizable.

Resting on the muddy banks of the lake,

the floating houses look strange

in their immobile sate.

In the rare canals that still remain,

the water can reach temperatures

of 30 degrees Celsius.

For Kuy Ann, it's time to move his crocodiles

onto the land.

Transferring the creatures to their new habitat

requires a great deal of care.

It's a delicate operation,

the crocodiles mustn't be hurt,

and neither of course must their owner.

The fisherman knows that the crocodiles

will take advantage of their stay on land to reproduce,

helping his lucrative farm to prosper.

With the water all now gone,

the flooded forest is completely changed.

It's the season where the land animals,

swamp deer, makoks, and giant bats,

retake possession of the forest.

Near the villages, the now accessible forest

becomes a valuable resource for the human population.

During the dry season, it's exploited

in an intensive manor.

The villagers go there to gather indispensable wood

for cooking, chop trunks to use as stilts for new houses,

and collect the wherewithal for repairing their boats.

During this season, a large number of fishing birds

concentrate in the last stretches of forest

that are still flooded.

The heat causes short-lived showers,

which attract fish to the surface

in search of insects.

They're easy prey for the pelicans and egrets,

the only species of bird that still haven't migrated.

Simon Mahood is back at his favorite spot,

the bird reserve at Prek Toal.

He's come to take over for his colleague, Sun Wisal,

and draw up a provisional report

on their actions here.

The flood was slow

and all the trees are visible

above the surface of the water now.

It's completely different from when we were here

at the height of the flood season in November.

Huge numbers of birds come to the dry season streams

in Prek Toal at the end of the breeding season.

This is the only place where the water remains,

and so the fish are concentrated here.

The water is very shallow,

and so it's easy to catch fish.

Big numbers of oriental daughters and cormorants

take advantage of these fish,

and they feed up before flying off across Asia.

There's a huge pelican in front of us,

but it wouldn't have been very flight.

The birds have been hunted

for hundreds of years by people,

and so they're afraid of people and of big boats.

It's incredible that one lake

has got such a range between high floods

and low floods season,

and it's this that allows so many different bird species

to breed here.

In this way the Tonle Sap is unique in the world,

and very special in my heart,

because there's no where on Earth like this

and no more special place that we could have protected

such huge numbers of birds,

to the benefit of everybody in the region.

For how much longer

can Tonle Sap go on playing its protective role?

Eric Baran knows that major changes are underway,

far from the lake in the Northern stretches of the Mekong.

The scientist has a lot to be concerned about.

As Tonle Sap is inextricably linked

to the rest of the Mekong,

it's totally dependent on what happens up stream.

And the major threat from up stream comes from the dams

because these are being developed at a frantic pace.

In 2000 there was 16 dams,

by 2030 there will be somewhere between 77 and 88,

that breaks the whole system into segments,

it holds back the flow of sediment,

and there'll be a big reduction in fertility.

The people don't have enough time to adapt to that,

they adapt to the seasonal changes

and they've adapted over the course of history,

but this is happening too fast.

The children wont have the time to go to school for years

to learn new ways of earning a living.

The impact of this rapid development

will be all kinds of nutritional and social problems.

It's not the dams themselves that are the problem,

the system is evolving, people need electricity

but it's all going too fast.

For the moment, despite this imminent threat

to the people and the biodiversity,

millions of Cambodians continue to live in harmony

with their great lake.

The inhabitants of Tonle Sap

can not imagine that one day things

may no longer be like this,

and that the lake will no longer provide them

with all its riches.

In the minds of the Tonle Sap fishermen,

the return of the waters is never taken for granted,

it's a gift of heaven.

They trust the lake, and have faith

that the ancient divinities which inhabit it,

will bring the lifesaving monsoon.

So far, the Mekong's flood has always kept its promise.

This year yet again, the water flowed back up to the lake,

depositing its rich mud and bringing with it

countless fish.

Once again the Mekong flooded the Khemara land,

fertilizing the forests and fields,

the people sewed and harvested,

the fish and the birds multiplied,

the plants and the trees thrived,

but all of this happened only because

Cambodia's great lake accomplished yet another

entire life cycle.

Once again, Tonle Sap, the bounteous lake,

gave far more than was ever asked of it.