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 they 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.

By the Atlantic ocean coast in northeast Brazil

is a huge expanse of sand dunes,

peppered with a string of lakes.

A place of breathtaking beauty,

the Lencois Maranhenses.

Paradoxically, this desert gets

more rain every year than Scotland.

Thousands of freshwater lakes then form

in the hollows of the dunes,

turning the white desert into one huge tropical beach.

This water makes it possible

for some rare but tenacious creatures,

human beings, too,

to survive in this extreme environment.

But the wet season is only one part

of the life cycle of the Lencois Maranhenses.

The water disappears almost as quickly

as it appears.

During the dry season,

the sand becomes, once again, dominant.

The Lencois Maranhenses are the product

of a unique combination of water, sand, and wind,

creating a mysterious ecosystem

with many secrets still to be revealed.

It's an astonishing landscape

of magnificent nature.

It would be a perfect laboratory

for any biologist,

but for me, it's more than that.

This is my land.

I was born here.

I love this place,

I love the people that live here.

I would say that a type of the ecosystem

is quite special as well.

It's unique, we cannot find something like this

in the world.

Located near the equator,

in Maranhao state,

the dunes that form Lencois Maranhenses National Park

cover a surface area of over 1,500 square kilometers.

Lencois Maranhenses is Portuguese for

"linen of Maranhao."

And it's true that these dunes of white sand,

stretching as far as the eye can see,

do look like a sheet,

negligently thrown over an immense bed

the size of the landscape.

It is now May, the end of the rainy season,

and water is the dominant feature.

15 years ago, while he was working on his doctorate,

Jivanildo Miranda spent over a year

camping among the dunes.

This Brazilian biologist and reptile expert

wrote the first in-depth study of the fauna

of the Lencois Maranhenses.

The scientist has done truly pioneering work,

devoting his life to the study of this little understood

but fascinating region.

Since then, the poor student has become

a respected academic, more than happy

to guide his students barefoot through the dunes

and share his passion for this magical place.

For Royana and Ramazio,

every day spent in Jivanildo's company

is yet another unique chance to improve

their understanding of this little-known ecosystem.

We are in the very heart of

a huge transition of biomes in Brazil.

We are in the transition of the Amazon forest,

Cerrado, which is a savanna-like vegetation,

and Caatinga, a type of arid biome

that you have here in Brazil, and

this is why, here in this spot,

have a mix of species

from those different type of biomes,

and those make it very, very special,

very particular, and

besides, we have an additional

transition, that is the transition from

this sea to the inland,

under strong influence of Cerrado vegetation.

Apparently, this land could look

like a dead land.

No life around here,

only dead logs.

But if you look carefully,

you're going to have amazing surprise,

there are a lot of life

hidden in this area.

This area we have two species of lizard

that can be found,

it's one lizard, the Cnemidophorus genus,

it's a lizard that's adapted to dig holes,

and then it can thermoregulate

when it's too hot for them.

They can just show here,

this Tropidurus,

it's a lizard that's not able

for this digging stuff, but

its able to hidden and control its temperature

just looking for some shelters,

and the logs and little piece of materials

that are around the park.

There are a lot of life, as well.

We have a turtle that,

probably it's active now,

because it's active only during the rain season,

and we have also tadpoles of many frogs

that reproduce in this type of environment,

and you have fish.

Despite the presence of water,

vegetation is still rare among the dunes.

It's sand which predominates.

Yet Jivanildo knows that life,

albeit on a small scale

and with a fragile hold,

does hide in and around these lakes.

- There are a lot of mystery,

because most species are poorly studied,

and I'm pretty sure

that as we increase our knowledge about them,

we are going to find out

amazing and very interesting

stories to tell.

The scientist's research

has brought to light an unexpected particularity

about this mostly mineral environment:

the presence of a large number of aquatic creatures.

Pleurodema diplolister, a small frog no bigger

than a fingernail, has particularly caught his attention.

It takes a real expert to spot this minuscule amphibian

in its natural environment.

It divides its time between the sand,

into which it burrows in order to protect itself

from the heat, and the lakes,

where it finds its food.

But these tiny Batrachians rarely venture

into deep water in this season,

because one of their main predators

will most likely be found there, hunting.

Rare and protected, the peninga

is a turtle with an insatiable appetite.

The biologist knows that during the wet season,

the turtle spends most of its day underwater,

hunting down its prey.

Its diet consists mostly of small fish,

insect larvae, and tadpoles.

It is constantly hunting for food,

because it must store the maximum amount of energy

and then reproduce before the water is all gone.

The scientist has noticed

that a lot of the denizens of these temporary lakes

live a speeded up life,

having only a few months in which to accomplish

their biological life cycle.

Jivanildo Miranda knows

that the least of them is as important a part

of the ecosystem as any other.

He considers even the most minuscule creature

of this environment worthy of study.

Late in the afternoon,

when the sun's rays are less fierce,

the peninga changes lakes,

in search of new prey.

At the center of the national park

is an oasis of greenery surrounded by dunes,

which the inhabitants call an island,

Queimada dos Britos.

It's the only place in this part of the desert

which offers a little shade,

so it's here that the professor and his students

have decided to bed down for the night.

But to get there, they must first cross

the Rio Negro, the park's only permanent river.

Without it, there would be no oasis or village

at the heart of the dunes.

Visitors are rare here,

but always given a warm welcome.

- Hello, Raymundo, how are you?

Very well, thanks.

- Do you remember me?

Of course I do.

- You know who I am?

- The frog catcher.

These are my students, Royana and Ramazio.

Pleased to meet you.

- Raymundo, do you have somewhere

we can put the horses?

- Yes, just behind.

- Thanks, see ya in a bit.

Raymundo is the patriarch of the village.

His grandfather, Zebrito,

was the first person to settle in this place

almost 100 years ago.

At the time, his native region to the east of Maranhao

was suffering a terrible drought.

So the nomadic fisherman traveled up the coast by boat,

until he discovered the mouth of the Rio Negro.

Amazed to find so much fresh water

surging out of the desert,

he worked his way upstream,

discovered this oasis,

and decided to settle here.

Zebrito and his family

were the very first inhabitants of the Lencois Maranhenses.

And thus was born Queimada dos Britos,

the hamlet named after the family.

- What has changed the most, in your opinion?

- The dunes,

which are encroaching on us more and more.

- Have they buried homes?

- Yes, mine, my first house,

the dunes took it from me.

- So the dunes are encroaching more than they used to?

- That's right.

- Because it rains less?

- Yes, less and less.

- But it's rained a lot this year, hasn't it?

- Yes, it's rained, thank god.

- Raymundo, has the work that the people do here

changed, too?

- There's more livestock farming.

- Twice what there used to be?

- Yes, there's more than twice as much.

We've had to stop growing crops

because of the dunes.

We advise people not to grow crops,

in order to slow down the dunes' advance.

- I see.

You are trying to hold back the constant

encroachment of the dunes.

- That's right.

Crop farming and livestock are,

in theory, forbidden in the park,

because they destroy the fragile vegetation

which keeps the dunes steady.

Yet the authorities show a certain amount of

tolerance for these activities,

because they have neither the means

nor the will to rehouse families

which have lived in the park for generations.

The year Jivanildo spent studying the park

taught him that a large part of its fauna

can only be observed at night.

But nocturnal hunting has its dangers.

Although rare, a few poisonous snakes and spiders

live in these bushes.

To carry out

fieldwork during the night,

it's really important for me,

otherwise we are not going to be able

to record all the species that live in this park,

because many of them

are reactive only during the night.

This is a Kuru toad,

native to the Lencois Maranhenses.

It has venom glands on its rear limbs,

and by its cloaca,

so its skin is toxic.

It's a close relative of Rhinella marina,

an invasive species of toad

which has caused lots of problems in Australia.

It's a common toad in the Lencois Maranhenses,

found in the restingas, among the trees and shrubs,

as well as in the dunes.

You have to look very closely to see it,

because of its coloration.

It's perfectly camouflaged for this kind of environment.

Go that way.

Be careful, it's very quick.

It'll try and get away.

Take care not to harm the vegetation.

It's not poisonous, but it's very quick.

This is a Thamnodynastes hypoconia,

one of the most common snakes in the park.

People are very frightened of this species,

because of its aggressive behavior.

It acts in a very threatening way,

darting with its head

and trying to bite.

This makes it appear really dangerous.

It has vertical pupils,

because it's a nocturnal creature.

It's also a very interesting snake

because it's a viviparous species,

meaning that it doesn't lay eggs,

but gives birth to live young.

The local name for it is "goipeba,"

and people are really frightened of it.

They think it's deadly poisonous,

but that simply isn't so.

This morning, Jivanildo and his students

are moving on again,

this time to the hamlet of Santo Amaro,

located on the western edge of the park.

It's a good five hour walk away.

In the dry and extremely loose sand of this desert,

making headway is difficult.

The dunes of the Lencois Maranhenses

consist of a fine white sand,

originating in the mountains to the south of the park.

For hundreds and thousands of years,

the major rivers of Maranhao

have torn off pieces of the continent's rock,

sweeping it into the Atlantic ocean.

On their long river journey to the sea,

these mineral fragments are gradually ground down

into particles as fine as dust.

It's these tiny grains of naturally polished quartz,

as transparent as glass,

that make the Lencois Maranhenses sand so white.

The sand is also exceptionally fine.

Blown from the shore by the wind,

the sand has accumulated over this coastal area of Maranhao

for millennia.

On a geological time scale,

the Lencois Maranhenses are a relatively young landscape.

Most of the sand of these dunes

has only been here a few thousand years.

Another remarkable feature of the Lencois Maranhenses

is that water is omnipresent here.

Not only in the lakes,

but also under the ground.

Under the basins in the hollows of the dunes,

the groundwater can be reached at a depth

of only 10 or 20 centimeters.

People used to drink the water in the lakes.

But now, with cattle in the park,

the water isn't as clean as it used to be.

There. That's water naturally filtered by the sand.

- So, the groundwater isn't very deep down at all?

You just have to dig a little hole to get at it?

- All the water in the Lencois Maranhenses

comes from the Inter Tropical Convergence Zone,

near the equator.

That's where the clouds come from

that bring the rain here.

The northern Maranhao region, where we are now,

is very sandy,

and the groundwater is at a very shallow depth.

The water accumulates between the dunes,

and causes all these lakes to appear.

In fact, you could think of it more as one huge lake,

formed by many smaller lake-lets,

all of them interconnected.

Built near one of the Lencois Maranhenses's

few permanent lakes,

the houses of Santo Amaro are protected

from the sun and the encroachment of the dunes

by the restinga, a thick tangle of thorny bushes

whose deep roots give some stability to the sand.

During the wet season,

the hamlet's inhabitants spend much of their time fishing.

In their nets, they catch considerable quantities of

traiarao, cara bicuda, and jacunda,

the lake's most common fish species.

In a region as poor as this,

having such a readily available food source

is a real godsend.

- Whether it's winter or summer, we fish.

During the dry season, the water level drops,

and it gets harder to catch the fish.

That is why the people here don't live only on fish.

They have to work on their farms

and do other little jobs to survive.

But in spite of all that, people love the life here.

They wouldn't leave for anything in the world.

And the same goes for me.

Even those who leave end up coming back,

because they miss it so much.

They can't bear to live anywhere but here.

Despite the fish, the main activity

of many Lencois Maranhenses inhabitants

is the rearing of livestock.

During the wet season,

most of the herds roam free among the dunes,

picking at the rare bits of vegetation they can find.

- Hello! - Hello.

- How are you? - Fine.

How are the goats doing?

Okay.

Do they get sick a lot?

Yes, quite a lot.

What sort of things?

- A cough, like a sort of pneumonia.

They also get a problem with their feet from the rain.

It rots their hooves.

Have you lost many?

- Yes, especially in February,

during the rainy season, we lose a lot of goats.

They get swollen bellies,

and we have to give them sugar water,

a remedy which helps them a little.

We deal with it the best we can.

- They have a very, very simple way of life.

They are tough people.

They work a lot, they work all the time,

they fish, they raise those animals,

it's a very, very old way of living.

And they live in a very difficult area.

And they have to work hard to provide

food for the families.

I met them by chance, I was

walking around this area,

and decided to knock the door one day,

and then introduced myself and explained

what I was trying to do around this park,

and they were very friendly,

they are a very friendly people,

and they helped me a lot.

At the time it was also nice

for me, psychologically, to have this contact

to these people, because I spent many days

in the field and sometimes it was hard,

and today, for me, they are like my family.

I really appreciate when I have the chance

to come back and talk to them.

It's very nice people.

- It's funny, everyone thinks you're a local.

- Yes, I feel at home with you.

As a scientist, Jivanildo understands

that the livestock have a negative impact

on the park and its vegetation.

But as a child of Maranhao, he also knows

that the inhabitants of Lencois Maranhenses

depend on their herds in order to survive.

For a long time now he's been fighting a campaign

for the park's environmental policy

to take the human factor into consideration.

Being close to these people and speaking their language,

Jivanildo Miranda hopes he can convince the inhabitants

of the Lencois Maranhenses of the priceless nature

of the riches to be found

right outside their own front doors.

From August to December,

a strong northeasterly wind blows almost constantly,

at an average speed of 50 kilometers per hour.

This wind is the harbinger of the great metamorphosis

the Lencois Maranhenses will undergo.

The end of the rain, and the start of the dry season.

Spread out among the dunes,

the cattle have cropped all they can

of the meager clumps of vegetation growing in the hollows.

Everything will soon have dried out.

It's high time the cattle

were back in their enclosures.

For months on end,

the sun, sand, and wind will join forces

in a pitiless war waged on the water.

Under the wind's constant blowing,

the dunes slowly advance

at a pace that's invisible to the naked eye,

but inexorable all the same.

And under the burning sun,

the lakes dry out,

turning into deadly traps

for the last few fish.

The elements don't let up

until the last drop of water has evaporated

and the Lencois Maranhenses have turned into

one vast desert.

To the east of the park

is the lush, copiously irrigated landscape

of River Preguicas.

It is now October.

In the dunes, water has lost the battle,

but here, it's triumphant.

Belgian biologist Kay Van Damme

is back in the region for the first time in 18 years.

The Lencois is a very interesting ecosystem

to study because although it is relatively young

geological phenomenon, or relatively young ecosystem,

it is extremely dynamic, and so

populations that survive here can show you

evolution on a very short time scale.

They have to survive these

pools that dry out and come back every year,

and also they survive in all these different pools

that are sometimes connected, sometimes not connected,

so populations get fragmented into different parts,

and then they get rejoined,

and this is one of the processes that drives

genetic diversity and drives speciation.

To the Lencois is an ideal place to actually

study speciation and study the drivers of evolution

and the drivers of biodiversity,

and there are very few areas where you can actually

study this, and this is a hot topic in biology,

and it is a very interesting thing for me to study.

Kay Van Damme is one of the very few

non-Brazilian scientists to have studied

the Lencois Maranhenses in any depth.

He's back now to study this special ecosystem

during the most mysterious phase of its cycle:

the dry season.

His area of expertise is the fauna

that lives in and around the periodically dried out dunes.

But before venturing off among the dunes,

Kay goes to visit Nestor, an old acquaintance.

Part shopkeeper, part livestock breeder,

Nestor built his house between the river and the dunes

at the very spot where the two opposing worlds meet.

It seems like a peaceful spot,

but appearances can be deceptive.

In truth, it is a battlefield

between powerful opposing forces.

As elsewhere here, the truce that reigns

between salt and water is a fragile one,

liable to be broken at any moment.

Hello!

Hello.

- How are things with you?

- Not too bad, thank god.

- Nestor, it is after,

since 1996 that I come back to the Lencois,

and a lot of things have changed, I've seen,

so I was wondering how this is for you as well,

if you have the same feeling.

- The dunes used to come right up to here.

And the water flowed behind and front of

the sand bank that my house stood on.

But one day the water just poured in and formed a lake.

In the end, I had to abandon my house

because the water was too high,

it came all the way up to here.

I couldn't stay trapped between

the water on one side, the dunes on the other,

and then, after about a year,

the lake completely disappeared,

as though the ground had just swallowed it up.

The wind blew the sand back,

and it filled up the hole.

All of a sudden there was no water at all.

That's the way things go around here.

- Thank you, Nestor. May God be with you.

- Thank you.

- Thanks, Nestor.

- Yeah, see you soon.

It is very important for a scientist

that this is considered a national park,

because the Lencois, like other areas in the world,

are very attractive, very nice,

and without a certain protection

of the whole area, it could change very rapidly,

and it could become completely different.

The shortest route to the dunes

is the beach along the Atlantic ocean,

the northern boundary of the park.

Kay's expedition is heading for the mouth of the Rio Negro.

This is the spot where the only river

that still flows through the dunes during

the dry season reaches the sea.

The continuous running of water here

has dug a deep trench in the sand.

It's one of the few spots

where the very particular geological structure of the park

can be clearly seen.

The secret of the Lencois lays under the sand.

There is a layer of peat,

there is a layer of turf, and there is a layer of clay,

on which the sand is deposited.

These layers contain organic material

from former vegetation that was here

before the sand was deposited,

and we can see the proof of this

by the color of the sediment that is below.

The Lencois is geologically relatively young,

most of the sand that you see here

was deposited between 15,000 and 4,000 years ago.

20,000 years ago,

during the last glacial maximum,

a large proportion of the planet's water

was frozen in glaciers.

The average sea level was from 80 to 100 meters lower

than it is today.

The sand, which had accumulated under the sea,

was therefore exposed to the air.

For thousands of years,

the wind drove this sea sand at the continent,

until it totally covered the coastal areas and vegetation.

The organic matter thus buried under the sand

underwent a slow metamorphosis,

finally forming the dark geological layers

that we find under the dunes today.

The secret of the Lencois lies in the fact that

below the sand, which is permeable for water,

there is a harder layer that

keeps the water during the wet season,

and then, once it's full,

this water will overflow in the deeper cuvettes,

and these cuvettes are the pools in the Lencois.

There are thousands of small pools and lakes,

but in a way, we can consider this area as having

one large lake.

We cannot see the lake, it is under the sand,

and it is actually the large phreatic water table

that connects all these pools during the rainy season.

Few creatures still venture through the dunes

during the dry season.

This seemingly lost armadillo

won't survive for long in the debilitating heat

if it doesn't find some shelter.

Finding creatures in the burning desert

will be no easy task.

Fortunately, Kay can count on Joilson,

who comes originally from Baixada Grande,

the park's other oasis.

I chose to do research in the Lencois

because it has some basic elements

that appeal very much to a young biologist.

One is the novelty,

it is a region that is not very much studied.

The second is the aesthetic value,

it is a beautiful area to come and explore,

and a third is to actually explore

and look at animals that are relatively badly studied.

So that appealed to me, but even

after 18 years, the feeling is

exactly the same coming back here.

We'll take the air temperature.

- Wow, that's hot!

- It really is very hot.

39 degrees Celsius.

Shall we go that way?

- Okay, let's go.

When we look at a lake like this,

one would not think it is a lake,

because everything is dried out,

and here in the Lencois,

the water dries out

and then it comes back, so

waters are very temporary and short-lived.

It seems to be that there is

no life in this place, not right now,

but this is the wrong perception.

Within a small piece of sediment,

it's full of different animals,

and also plants that can be revived

once water comes into contact.

In changing environments such as this,

animals have to adapt,

and if they do not adapt, they will go extinct.

So it is an environment such as the Lencois

where animals adapt quickly,

both on a yearly basis,

but also on a longer time scale.

- Kay! I found a peninga!

- That's great!

- It's usually really hard to find one.

- Pretty rare, huh?

- Very rare.

It's magnificent.

- It's a female, a young female.

- How can you tell?

- The coloring is a bit lighter.

There are light ones, and slightly darker ones.

So, this turtle is an example of species that are

adapted to this special environment,

whereas in Europe we have species that are

adapted to very cold winters,

which is the harshest climate that we have,

and animals go into hibernation to survive.

In here, in tropical and arid ecosystems,

animals can into estevation.

They can reduce up to 90 percent of their

metabolic activity on a cellular level,

which means in this period, for months,

they will not need food

and they will go into a kind of sleep mode.

The environment allows them to actually

emerge again from the sand

and come into, again,

a new, freshly formed aqua ecosystem.

The Belgian scientist's special area

of expertise is cladocera, or water fleas,

tiny crustaceans which form the basis of

the food chain in the lakes.

The samples he takes contain thousands of these water fleas,

but the minuscule creatures are invisible to the naked eye.

To see them at all,

the scientist will at the very least

need a magnifying glass.

When the lakes of the Lencois Maranhenses dry up,

life doesn't totally disappear.

Many of the creatures, including the fish,

lay eggs, which are able to survive the dry conditions.

Buried in the dehydrated sediment,

these dormant eggs are resuscitated

as soon as the water returns.

And life returns to the lakes

according to an astonishingly precise chronology.

First there's the plankton,

soon followed by water fleas,

then the fish, and finally the frogs and turtles,

which emerge from the sand

in which they buried themselves.

The food chain always reestablishes itself

in the right order.

If it didn't, the survival of all of these

interdependent species would be at risk.

It is now October.

Just a few shallow ponds remain.

And yet, despite the arid conditions all around,

water is never far away.

Only a few meters under the sand

lies the Lencois Maranhenses's

huge body of groundwater.

No one knows exactly what the volume

of this immense underground lake might be,

but there is no doubt that its water

is an inestimable treasure.

Kay has chosen to set up his base camp

in Baixada Grande,

Joilson's native village.

While the horses enjoy a cooling down,

the scientist is finally able to examine

the samples he took from the lake beds.

- Until I came here in 1996 and 1997,

there was no research that had been done

on the microscopic invertebrate life

of the Lencois.

And we described several species

for the first time from this area.

So in fact, for diversity in Brazil,

this is a special place, because

this is what we call a type locality for several species,

this means this is the original place

where this particular species has been described.

When I take samples from these dried areas,

I am very interested in looking

which animals are in the sediment,

and how they resurrected from there.

So there is a field of biology which is called

resurrection biology, and animals that come out

are very interesting.

Water fleas are very interesting,

they have a very interesting life cycle.

They are animals that can reproduce clonally,

without a need of a sexual stage.

However, they can do this only if the ecosystem

remains stable, so when

the animals that will hatch will be females

that will reproduce identical clones to themselves,

eggs that are constantly reproduced,

so they have a lot of twins, so to say,

and sisters and daughters that are identically,

genetically identical within the pool.

And then, when the ecosystem changes,

they will produce males

only in this case, and then by

recombining the males with the females,

they will produce an egg that is

more adapted for the next generation to survive.

So this means that each season,

there is a new generation that hatches.

And because the cue for making,

for changing, for example, the sex of the offspring,

is purely ecological,

so instead of being originally genetic,

it is purely ecological cue that says,

okay, now we have to produce males,

because the season will change,

and this is very, very special,

and this is a very interesting topic

because the males and the females

are genetically completely identical,

but they are completely different morphologically.

Then they will form a new resting egg

that they can dry out completely, and so

after a period of dry season,

for example, they can hatch again,

and then the cycle starts again.

The samples Kay Van Damme collected

have by no means yet revealed all their secrets.

In a few weeks, when the scientist is back

in his laboratory, all he will need to do

is pour a little water onto the dried out sediment

to stir an incredible diversity

of animal and vegetal life from its slumber.

Once studied, these samples may be found

to contain new species, or reveal yet more

hitherto unknown aspects of the secret life

of the Lencois Maranhenses.

In February, the wind finally changes direction,

and gets a new name.

It is no longer the banal "vento"

blowing from the northeast,

but the "terral," a wind from the land

which blows from the south,

bringing with it clouds heavily laden with water.

The rainy season is finally back again.

For four months, intermittent but torrential downpours

will batter the Lencois Maranhenses.

More than a meter and half per square meter.

Resurrected by the water,

the lake's animal and vegetal life

doesn't take long to reappear.

Once again, the Lencois Maranhenses

will have completed their life cycle.

The return of the rains

also marks the beginning of the sea fishing season.

It's time for Joilson to join his father

and the other fishermen of Baixada Grande

on the beach.

My grandfather lived in Ceara state,

in a very dry area.

He discovered this place

where there's never any lack of water,

and he fell in love with it.

Not only was it beautiful,

but there was water in abundance.

That's the Rio Negro.

I used to play in it when I was a kid.

But today, the dunes have invaded half of the river,

and its level has dropped considerably.

The cabins built by the fishermen

at the ocean's edge are exactly the same

as the ones the Tremembe Indians,

who formerly lived in this region,

used to construct.

Simple but strong, these shelters,

with their low-hanging roofs,

are economical in their use of construction materials,

and require little in the way of upkeep.

Although the flow of the Rio Negro

has diminished a lot over the last few years,

the spot where it meets the sea

is still especially good for fishing.

The casoiera, the net which the fishermen

of the Lencois Maranhenses use,

is about 30 meters long,

but less than 2 meters deep.

The wading fishing technique,

one of the most ancient in existence,

consists of driving the fish onto the beach.

We live right next to the sea,

and it's full of fish.

So when we want to eat fresh fish,

we just go and catch some.

It's for our own consumption, not for selling.

For the most part, we only fish what we're going to eat.

If we catch too much, it has to be salted,

which gives it a very strong flavor.

So we mostly just take two or three kilos,

enough for our daily needs.

While most of the fish

that the oasis's inhabitants catch is eaten without delay,

there is sometimes a small surplus

that's immediately preserved for consumption

at a later date.

Once the fish has been gutted and scaled,

it's salted, and then left to dry

on the roofs of the houses.

Preserved in this way,

the fish will keep for several months.

The fearsome sun of the Lencois Maranhenses

can thus sometimes prove to be a useful ally.

- I think that one day

the dunes will end up burying my house.

When the summer comes, the dunes encroach a lot,

driven by the really strong wind.

In winter they don't move so much,

but as soon as summer comes around again,

they destroy all the vegetation,

advancing quickly and covering everything.

I think that one day the dunes will cover everything here.

Including my house.

It was a perfect spot for planting crops.

It's my farm.

And I'm sure I couldn't find such a beautiful place

anywhere else.

That'd be hard, wouldn't it,

finding somewhere like this,

where I could plant my crops.

It saddens me not to have my crops anymore, but

what can I do?

How much longer can this

simple way of life go on

in the ever changing world of sand and water

that is the Lencois Maranhenses?

The Lencois Maranhenses are a paradoxical landscape.

Depending on the season,

they may appear to be a region of lakes

invaded by sand dunes,

or, conversely, a desert

flooded with fresh water.

It's undeniably a hostile environment,

which imposes severe constraints

on the creatures that live here.

But this unique environment

has also created an ecosystem worthy

of its great beauty.

Plants, animals, and human beings

have adapted to it,

and learned to live in accordance with the life cycle

of these lakes of sand.

And yet, when measured against

the immensity of Brazil,

the Lencois Maranhenses are just

small islands of sand and water,

caught between the rest of the continent

and the ocean.

Seen from this perspective,

this extreme ecosystem reveals its true nature,

and suddenly seems terribly fragile.

And the need to protect it from the inevitable changes

awaiting it becomes all the more urgent.