Andrea - Queen of Mantas Natural World

The first time I saw a manta it took my breath away.

It just came out of the gloom right towards me and it was like

the most beautiful underwater bird I'd ever seen.

It was so majestic

and I couldn't even focus on anything except this magnificent animal.

This chance meeting changed the course of Andrea Marshall's life.

Manta rays are unlike anything I've ever been in the water with.

They're inquisitive, they will engage a diver.

It's just an amazing experience to be with them

because you can actually see that they want to interact with you, and they are quite curious.

And it was a brief encounter,

but at the same time I knew then that I would never be the same again.

Abandoning her life in California, the young biologist moved to Africa

for a life with manta rays.

Her dream -

to find out all there is to know about these mysterious creatures.

And seven years on, her work has rocked the world of science

with the discovery of a new species of giant manta

and remarkable new findings about how they live their lives.

But around the world, mantas are in trouble - their numbers crashing.

It is terribly frightening that something as beautiful and as important as a manta ray

could ever be brought to the brink of extinction.

From fighting to protect these beautiful rays

to ground-breaking revelations about their secretive lives,

this film charts a remarkable year of Andrea's life living with mantas.

Tofo Beach, Mozambique,

where the Indian Ocean meets the east coast of Africa.

And it's here, on this wild, inaccessible stretch of coast,

that Andrea lives and works.

Look at him! Too cool!

We've motored about five miles down the coast

to dive at one of the many inshore reefs off here.

The place we're going today is called Manta Reef and it's a renowned cleaning station for manta rays.

Every day, Andrea makes the ten-mile round trip

to one of the many reefs that are scattered amongst these waters.

I think we should dive the south side of the reef today.

So about another 400 metres, and slightly to the left would be good.

And it's amongst these newly discovered reefs that Andrea has

found one of the largest populations of manta rays in the world.

Do me a favour, if you see any pregnant ones down there, just keep a track of how many that you see.

We'll be about 40 minutes, OK?

Several major currents converge at Tofo,

creating some of the richest waters on the African coast.

I hadn't actually seen anything quite like the Mozambique coastline

when I first came here.

There was just so much life here.

It was like the Galapagos of the Indian Ocean.

There's so much plankton, it turns the waters cloudy

drawing in leviathans from across the Indian Ocean to feed.

And it's here, living amongst these reefs,

that Andrea has discovered more than 650 manta rays.

With a wingspan of up to seven-and-a-half metres,

mantas are the largest of all the rays.

Once feared as dangerous devil fish, they're in fact harmless giants,

feeding only on the tiny plants and animals that make up the plankton.

Yet intriguingly,

mantas could be one of the most intelligent creatures in the ocean.

For their size, they have the largest brain of any fish,

and no-one knows why.

They almost have personalities.

Some of them are more shy, some of them are more bold.

Some of them love bubbles on their tummies, some of them don't.

They don't swim away from you like a normal shark or fish would.

So they really engage you,

and it makes working on them all the more fun.

And that's a great feeling as a biologist

to actually have a connection with the animal you're working with.

Despite their size and curious nature,

very little is known about manta rays.

So armed with her camera, Andrea records every move they make.

With each dive, she's discovering more and more about them.

Building up an intimate picture of their secretive lives.

Did you see Jo? She was one of the pregnant ones.

That's the second year I've seen her consecutively pregnant. That's amazing.

We saw a number of individuals, maybe about ten.

A lot of ones that I knew, a couple of ones that I didn't know,

a lot of ID shots, so there should be a lot of information there,

a few pregnant ones.

So that's a good sign. That's exactly what we want to see.

From this straw hut, Andrea runs the Mozambican Manta Ray Project.

And with the support of the Save Our Seas foundation,

she's transforming this remote site on Tofo Beach

into one of the leading research centres in the Indian Ocean.

At the moment I'm actually uploading my photos from today's dive

just to check the individuals I saw on the reef today.

Like a fingerprint, every manta's born with a unique spot pattern on its belly.

And it's the shape of these spots

that gives Andrea the inspiration for naming her mantas.

I try and see an image.

So I basically have named all 650 mantas

after something that pops out at me.

So I have names ranging from cartoon characters,

all the way to presidents.

Andrea calls the two new arrivals Spotty and Bleeding Heart.

And they join the likes of Homer Simpson and Dracula on her growing database.

What's important is not the name, but the fact that when I'm on the reef I know all the different individuals

I'm seeing, and the picture becomes so much more clear.

It's a more intimate type of research

and it's quite exciting because they are kind of like my little children.

And after thousands of dives with Mozambique's mantas,

Andrea's beginning to understand their lives.

She's found that many of them are resident to these waters.

But what surprised her the most was that 80% of the mantas were female.

I really strongly believe this is one of the most important sites,

a critical habitat for manta rays.

They are coming here to mate,

the females are hanging around for most of the year to give birth,

find mates and have their pups

which is probably why they occur in such large numbers.

By sheer luck Andrea had not only discovered one of the largest populations of mantas in the world,

but she'd stumbled across a manta breeding site.

There's nowhere else like it in the world.

But living in such a remote corner of Africa has been far from easy.

'It was very intimidating when I first moved to Mozambique.

'I actually didn't know anyone when I first came here.'

I try and act tough sometimes,

but I am a girl that came from a sheltered environment.

I grew up in California with a lot of close friends and family

and it was tough for the first few years.

'But at the same time, I knew it was going to be well worth the effort that was put in.'

I get a bit nervous driving around here,

because people hit a lot of people on these roads.

These roads are terrible.

What are you doing?

CAR HORN TOOTS

Speaking of why it is dangerous to live in Africa!

It's November and the manta breeding season has begun.

It's a key time for Andrea

and dive buddy and research partner, Simon Pierce,

but it's going to be a dangerous launch.

Conditions are pretty miserable today. There's huge swells.

Short distance between the waves.

It's not ideal at all.

It's actually quite dangerous.

People have flipped boats here before.

People have lost people over the side of boats.

But, you know, it's the only way we can get out.

With waves of up to three metres, no coastguard,

and the nearest doctor 30 miles away

there's no room for error.

You know you've got to get out.

I mean, there's no harbours to launch from here,

and so basically if I don't get out, I don't get to do my research.

SHE WHOOPS

Today Andrea is setting up a state of the art acoustic tagging study.

It will record what her reef mantas do when she's not around.

But to get the project started,

she's got to be good with a spear gun.

My shot's pretty good, you know.

We pick a place on the manta to shoot,

and I'm usually within a couple of inches of that shot,

so, I think I'm all right at least on my shot. Just not on loading.

Well, it helps that she's only about that far away!

As they make their way down to Manta Reef,

Andrea spots one of the ocean's rarest creatures.

It's a small-eyed stingray.

Tofo is the only place in the world where they've ever been seen alive.

At more than two-and-a-half metres across,

it's the largest of the stingrays.

And this brief encounter

is the first footage ever to be shown of them.

As the ray moves off,

Andrea and Simon set to work anchoring a special "listening post"

to the sea bed.

For the next 12 months, it will monitor the mantas'

day-to-day movements around the reef.

A manta Andrea's known for four years, called Tri-Star,

is the first to get a tiny acoustic transmitter attached to her back.

She's now emitting her very own signature tune.

FAINT BEEPING

Whenever Tri-Star comes within 400 metres of the listening post,

it will detect her signal, logging her in and out of the reef.

Got a tag on Tri-Star, which is one of my favourites...

I've known her since 2004, so that was really exciting.

And she was pregnant again so that was fantastic.

I'll just go back and see what kind of data we can get from her in a few months.

Over the coming days, five more reef mantas will be tagged.

These acoustic tags are giving us 24-hour information, 365 days a year.

So it's really fantastic technology.

Back underwater,

the mantas arrive on the reef in ever-increasing numbers.

During November they gather here to court and mate.

And the displays can be breathtaking.

Before Andrea started her work in Mozambique,

very little was known about manta breeding behaviour.

A female manta, when she's ready, when she wants to mate,

she will lead males on almost a chase

and you usually get a single large female

followed by what's called a train of many males.

Sometimes one or two, and sometimes it's 20

And they will chase her around the reef at high speeds and basically

everything that she does, the males will actually do behind her.

It's almost uncanny, so it's beautiful to see.

If she banks, they bank,

if she turns, they turn, if she flips, they flip.

Mantas usually give birth to a single pup

after a 12-month pregnancy.

But in another manta first,

Andrea's found it's very rare for them to pup each year.

That's one of the very important distinctions

that I've made here in Mozambique.

Manta rays often have one or two years off in between pregnancies,

and that's probably to recoup energy stores.

So the fact that they only have one pup every two to three years

is a very, very important in terms of conserving them because it means that they don't have the ability

to repopulate if they're under threat,

for instance, from fishing pressure.

With manta rays reproducing so slowly,

the only way for Andrea to protect them

is to make regular visits to the fishing communities

that line Mozambique's sparsely populated coast.

I want to know what season the people take and kill the manta rays here, what time of year?

He says in the summer months when the mantas are at the surface -

that's their breeding season - they will kill a lot, so that is very disturbing

and that's probably why they catch a lot of pregnant females.

The fishermen here are just trying to survive.

They don't know that these populations are fragile.

They don't understand that by taking even what seems like a few to them,

they can have devastating and permanent effects.

And it's not just mantas that are being hauled in.

Who do they sell this to?

HE ASKS QUESTION IN LOCAL DIALECT

We know that there are Chinese syndicates along this coastline

that are buying shark fins for a lot of money.

But they're very secretive about who they're selling to

and it's no wonder, they make a very good living out of selling shark fins.

The growing Chinese influence along this coast is a real concern.

Mantas are highly prized in traditional Chinese medicine.

And the financial rewards for poor fishing communities like this

could be hard to resist.

Throughout the world, in areas where they are fished,

mantas are listed as vulnerable to extinction.

The only way for Andrea to give Mozambique's mantas any long-term protection,

is to get this remote stretch of coast

recognised as a marine reserve.

These waters are visited by more whale sharks

than anywhere else in the world.

Whales, from humpbacks to southern rights,

are regularly seen here, too.

WHALE SONG

But there's a much rarer creature that comes here,

a creature that's led to Andrea's most remarkable discovery yet...

..giants.

Up to two metres larger than the reef mantas,

the giants usually stay at Tofo for just few days,

before disappearing back into the Indian Ocean,

rarely, if ever, to be seen again.

Until now,

it was thought there was just one species of manta in the ocean.

But the more Andrea swam with them,

the more she noticed how different they were.

With a wingspan of up to 7.5 metres,

they were not only much larger than the reef mantas,

but their markings were also much more pronounced.

All these little things started adding up.

I just had such a hunch.

I just knew...I just knew in my heart that there was a difference there.

But she needed proof.

And it came from a strange bump on the giant's tail.

When I first saw the tail, my heart was beating so fast, I just...

It's hard to explain.

Mantas evolved from stingrays millions of years ago,

and when they did, it was thought they'd lost their sting.

But while the smaller mantas had lost theirs,

Andrea found the giants still had the remains

of a stinging spine in the bump on their tail.

So to see mantas, a group of mantas that I knew was different,

have a spine still, it was amazing to me.

It was kind of seeing, like, the missing link in evolution.

It was the proof Andrea had been searching for.

And finally, she was able to announce to the world

that she'd found a new, giant species of manta.

For the then unknown field researcher,

with little more than a passion for mantas,

it was an astonishing breakthrough.

But where the giants go after their brief visit to the Mozambique coast,

that remains a mystery.

I have such a hunch that they are long distance swimmers.

I feel that they are very migratory.

I feel that they might be actually travelling really long distances.

If the giants ARE ocean travellers,

they're likely to be spending much of their lives

in the heavily fished waters of the Indian Ocean.

With the giants potentially at great risk,

for Andrea, the race is on to find out where they go and why.

Following up on all sightings of giants

Andrea's heading 3,000 miles across the Indian Ocean

to the Maldive Islands.

Here a manta research team

are reporting occasional sightings of giants.

As well as huge gatherings of reef mantas...

With more than 1,200 coral islands scattered across 500 miles of water

the Maldives have some of the richest reefs in the world.

-Hi! How are you going?

-Good, you?

-That was absolutely spectacular.

Guy Stevens from the Save Our Seas Maldivian Manta Ray Project

has been studying the mantas here for four years.

Well, I just got a call from the guys out there,

and there's about three whale sharks

-and 100 mantas.

-Oh, excellent. That's fantastic.

-OK? Right...

-Well, let's get in the boat.

The Baa Atoll is a circular chain of 60 tiny islands.

A network of coral reefs snake between them,

channelling the fast-moving currents.

-Look, Andrea, look!

-Look at them!

-Oh, there's one, there's one!

-Right here.

Oh, wow!

Look at him, wow, there's so many.

Wow, there's heaps right there, right now.

Here at Hanifaru, the currents sweep into a horseshoe-shaped lagoon,

creating the perfect conditions

for one of nature's most extraordinary events.

Wow, that is a massive group.

And you can see right down there.

-As many as you can see up here, it'll be full way down to the bottom.

-That is amazing.

-Can we get in and start looking?

-Yep. Let's go.

Nowhere else in the world

do mantas gather together in such huge numbers.

Within minutes, more than 100 arrive in the lagoon.

All are reef mantas.

The giants are nowhere to be seen...

'I'd never actually been in a situation like that

'with mantas before.

'I've never seen so many in one location.

'I've been diving all over the world with manta rays

'so it was actually a really extraordinary experience.

'They were just packed one on top of another - it was madness.

'I was just blown away, completely blown away.'

Never filmed before, the mantas only gather on this scale

for a few days each year.

And it only happens during the monsoon,

when spring tides cause strong currents

to draw up nutrients from the depths.

It creates the perfect conditions for a plankton explosion.

And a feast for the mantas.

This somersaulting, called "barrel-rolling",

funnels the plankton into their mouths in even greater numbers.

Then, Andrea spots some of the mantas

skimming across the lagoon floor.

Again, it's behaviour that's never been filmed before...

What they're feeding on is unclear.

It's likely the plankton, trying to escape the mantas circling above,

have sunk down and got trapped on the sea bed.

Intriguingly,

the mantas have changed the position of their front fins,

moving them away from their mouths

to get as close to the sea bed as possible.

I think that what all the different feeding behaviours tell you

is that mantas are thinkers, you know!

When the plankton's diffuse

they'll obviously swim through the water column with the mouth open,

but when it's concentrated they do these barrel rolls,

and when the plankton actually settles onto the ground,

then they change their feeding strategy entirely

and actually feed off the ground.

After more than an hour in the water,

the tide starts to change, sweeping the plankton bloom away.

As quickly as they came, the mantas start to disappear.

Pretty good, eh?

Oh, wow. That was sensational.

Have a look at all those mantas.

That had to have been the best dive I've ever done in my life,

I really do think.

I was dancing with them!

It was just incredible.

I know I didn't see any of the giants down there today.

-Did you?

-No. Not today. And that's not surprising for me.

I expect...

When I see one, it's like, wow.

It's an event. It's not like a regular thing.

-Do you ever see them in this area?

-Yeah, I've seen about two here.

And they'll be feeding with the others,

but they won't ever interact, yeah, associate.

So if you have a chain of mantas, you'll never get

the larger species, the giant mantas, interacting with the others.

As the light begins to fade,

it's time to make the one-hour journey back to Guy's base.

But the day's work isn't over yet.

You can just about make out the cluster of spots there.

You can see one, two, three, four, five, six, seven spots there.

And then it goes off to a circle...

Over the past three years, Guy has recorded ten giants in the Maldives.

By comparing the spot patterns of the Maldives and Mozambique giants,

they're hoping to find a match.

If they find a positive ID,

it will prove the giants are travelling large distances.

Is there any way we can zoom in on that a little bit?

But with all the cross-referencing done by eye, it's a slow process.

-I can say for sure that one's not in the population.

-OK.

-On to the next one.

-On to the next one.

Wow, that's very, sort of, dramatic markings, huh?

Dawn on day two of Andrea's trip.

And the photo comparison work is yet to find a match.

But with more than 70 of Andrea's giants still to look at,

there's a lot more work to be done.

Out at sea,

Andrea and Guy continue their hunt for giants

amongst the huge numbers of reef mantas

that have gathered, once again, at the Hanifaru lagoon.

Today, the plankton is higher up in the water column.

And now, great trains of mantas start forming just below the waves.

-It's amazing how they move in huge groups right at the surface.

-Exactly.

They've learnt exactly where to be at what time.

-A little more experience.

-Exactly...

Lining up behind each other in a staggered formation,

the trains travel up and down the lagoon

scooping up huge quantities of food.

This feeding strategy is a deliberate and highly effective way

of maximising their catch.

As the animal plankton sense

the pressure waves from the approaching mantas,

they try to escape.

But the following mantas, by moving in such a precise group,

leave the plankton with few places to go.

Sucked into the mantas' mouths, the feast is sieved from the water

by finger-like structures called gill rakers.

It's thought mantas can harvest more than 17 kilos of plankton a day.

As the mantas begin to disperse,

the world's largest fish arrives.

Growing up to 12 metres long, the whale shark,

like the mantas, feeds mainly on plankton.

As Andrea's week comes to an end,

there are still no sightings of any giant mantas.

And the photo ID work also draws a blank.

I had an amazing week here in the Maldives.

I'm so glad that I found the time to come out here.

This was our first step in trying to figure out if perhaps the giants

were making migrations from the African coastline to the Maldives.

But we didn't get any matches.

Andrea will need a radical new approach

if she's ever to find out where the giant mantas are going.

Back in Mozambique,

Andrea has taken delivery of two state-of-the-art tracking devices.

I took a band off the spear gun to try and limit the amount of power.

Her plan is to attach them to two giants to see where they go.

Out on the water Andrea begins her search,

but it's not just the mantas she has to look out for.

When the water gets murky and you see a manta swimming by

and it has blood trailing out of it,

you always look over your shoulder and you think,

"Jeez, what just did that?" And is it, you know, after me next?

Tiger sharks, bull sharks and great whites all stalk these reefs.

Down at 30 metres, there's no sign of any giants.

Only the reef mantas are around.

75% bear the scars of horrific shark bite wounds.

Bites like these come from sharks over four metres in length.

Quite why they're the victims of such frequent attacks is a mystery.

There's nowhere else in the world

where mantas get hunted on this scale.

But Andrea's discovered they have a special way

of surviving such terrible injuries.

Tofo's reefs are a hotbed of activity.

Creatures of all shapes and sizes come to the cleaning stations

to be picked clean of parasites and dead skin.

Injured mantas are frequent visitors here, too...

..queuing up for the attention of this tiny fish.

The butterflyfish.

Andrea has found they specialise in bite wounds.

Madonna, a female Andrea has known for more than five years,

has a fresh injury on her flank.

By nibbling her wound,

the butterflyfish removes dead tissue, preventing infection,

making the difference between life and death for Mozambique's mantas.

Butterflyfish aren't the only specialist cleaners here.

Schools of sergeant major damselfish

concentrate on the area around Madonna's mouth.

While cleaner wrasse swim right to the back of her throat

to pick clean her gills.

The giant mantas, when they're around,

are frequent visitors to these cleaning stations, too.

But with no sign of any today, Andrea will just have to keep

returning here until her luck changes.

Back on land there's better news.

The listening station she set up in November

is starting to reveal more about the reef mantas' secretive lives.

Already from the first manta we tagged, Tri-Star,

we've gotten some amazing data.

Sometimes she spends up to eight hours on the reef.

A lot of the mantas seem to be

spending extraordinary amounts of time on the reef, cleaning,

and that's something you don't see other places in the world.

Most people are reporting mantas cleaning for small periods of time,

maybe two hours max,

but I think the mantas here are spending more time on the cleaning stations

because they have these massive shark bite injuries.

The data has thrown up some further surprises.

None of the mantas that we tagged

are spending any time at the cleaning stations during night-time hours,

so where they go at night, whether they go offshore, or down the coast,

remains a complete mystery.

Andrea suspects they're moving out into open-water to feed,

or to avoid the sharks,

which are at their most active as the sun goes down.

It's her first glimpse into what Tofo's mantas are doing at night.

Four weeks later, and Andrea is facing a new problem.

Not only are there still no giants around,

but now her entire reef population has disappeared as well.

In seven years, Andrea has never seen anything like it.

Ah. That was a pretty rough day.

We've been going out for ages

and we can't seem to find a single ray in the ocean.

I'm getting thoroughly frustrated.

The conditions are fine, It's just, I don't know where the mantas went, so I'm pretty frustrated.

It's hard, you know, when the animal you study doesn't show up

for such a long period of time, you start to worry.

And I've heard of other researchers in the world

that have lost their manta populations

and then that's it, they have to pack up and move somewhere else,

so it does make you worry,

but we have such a stable population here,

I'm just hoping that that's not the case.

Andrea has good reason to be concerned.

Worldwide, entire manta populations are being wiped out.

I think the first time I saw a dead manta, it was actually in Mozambique

and fishermen pulled it up, it was actually an individual that I knew.

And, I couldn't control myself.

I was crying. It was really hard for me.

Worst affected are mantas in South-East Asia...

..their body parts used in Chinese medicine

to treat illnesses from diabetes to the common cold.

And increasingly there are reports of foreign fishing boats

working Mozambique's 1,600-mile coastline.

Four weeks later

and still no mantas.

An aerial survey is Andrea's last hope of finding them,

or at least to uncover the reason for their disappearance.

In the past, the mantas have vanished,

but only for short periods when plankton levels have dropped.

We've also had instances where a predator will come through the area,

a great white shark or a pod of orcas,

and everything will leave - whale sharks, manta rays,

and sometimes they'll leave the area for up to three weeks.

But even from the air,

Andrea can see nothing to explain their baffling disappearance.

So far we've seen turtles, humpback whales

but none of the manta rays.

They seem to have disappeared completely from about a 60km area.

With her entire population of over 650 mantas missing...

it's now a real crisis.

'The thing that really gets to me is just the waiting.

'I go out to sea, I check,

'I am in contact with dive centres up and down the coastline.

'I'm doing everything in my power to find my population.

'I just don't know where else to look at this stage.'

Two weeks later, and a full eight weeks since she last laid eyes on a manta,

Andrea's luck looks like it's finally changing.

I just got a call from one of the dive operators

and there's mantas on the reef.

I'm not sure which ones, but they could be giants so I've prepped the boats and we're ready to go out now.

If there ARE giants around,

it will finally be Andrea's chance to attach a tag.

But in the gloomy depths, mantas are nowhere to be seen.

Then, Andrea spots an unmistakable outline.

With its distinct markings,

the first manta to return to Tofo's reefs is a giant.

Far more wary of humans than their smaller reef cousins,

getting close to a giant is not going to be easy.

Something has gone wrong.

The tag has failed to attach.

Not good.

We're going to have that not happen again.

There haven't been mantas for weeks, finally we have a great opportunity.

They're back. There are individuals on the reef that are cooperative.

-And now, it's just so disappointing.

-Really disappointing.

We're going to have to go back to the drawing board tonight,

to figure out how to get this to work tomorrow, before these giants leave.

Andrea decides she can't risk waiting until tomorrow.

Right, copy that. We'll be swapping Richie over to this boat...

If her giants leave the reef tonight,

the chances are she won't see any more for weeks.

With her project already months behind schedule,

it's a delay she can't afford.

Two hours later they've done all they can

and the improvised tags are ready to go.

Seems like it should be fine. But nothing's ever fine in science.

But we'll try this one now.

30 metres down, the giant is still circling the reef.

It worked beautifully, I think.

It went in perfect.

I didn't see it again, but the tag looked so good when it moved off.

I think it's in there for good.

I hope it's on its way to, like, Bangladesh or something, far away.

Oh, it went in and I was going to cry I was so happy.

What a relief!

It makes it all worth it, you know?

So, first satellite-tagged manta in Africa.

Got to give it a pretty special name now.

-Simon.

-No, not Simon.

Two days later, Andrea tags her second giant.

Both mantas are new to her database, and she names them Cook and Magellan

after the famous oceanic explorers.

The sat-tag will record the mantas' every move for the next 60 days.

Then, if all goes to plan it will release and transmit

the giants' secrets to a satellite deep in space...

For now, all Andrea can do is wait.

Meanwhile, reports come in of an alarming trend

that could be a real threat

to both the giants and Tofo's reef mantas.

If you just go in to Google and type in "manta products"

you come up with several sites that are selling fins,

the gill rakers, skin... It's really alarming.

What's so shocking is that with the click of a button

I can actually add manta ray products to my purchase bin.

I mean, it's that easy.

These products are coming from India, they're coming from South-East Asia.

But it's that quick. You can access them that quick online.

The global online trade is a serious development.

Andrea's seen for herself the devastation it can bring.

I was just so sad that these animals were dead.

I was angry that this is still allowed to happen in the world today,

I'm angry that mantas aren't protected anywhere,

and I'm frustrated in the fact that science is often a very slow road.

So, yeah, I do get very emotional.

I won't lie.

Protecting her mantas and finding out where the giants are going

couldn't be more critical.

It's June and the satellite data

that could be the key to the giants' survival

is finally in.

Cook's tag released early, after just 22 days.

But the data it reveals is fascinating.

It was always thought that mantas spent most of their time in shallow waters.

But Cook behaved very differently,

staying down between 50 and 150 metres for half of her journey.

Why remains a mystery.

Magellan's tag stayed on for the full 60 days.

She made an incredible journey.

Leaving Mozambique, she entered South African waters

where 90 miles off Durban, the tag released.

The last data shows Magellan heading into the cold waters

of the southern Indian Ocean.

It's a journey of over 700 miles...

and the first evidence that Andrea's giants are,

as she suspected, ocean wanderers.

Where Magellan was heading will never be known.

But the significance of the journey is enormous.

It means protecting giants like Magellan

will need international cooperation.

As Andrea's year draws to a close,

there's a breakthrough for Tofu's reef mantas, too.

The latest listening station results are in.

For the first time, Andrea now has tantalising clues

about where her reef mantas give birth.

Tri-Star was pregnant when tagged.

And then, just as she was about to pup,

she disappeared from the reef.

What's really interesting about Tri-Star is that she only left

the inshore area for about two weeks, so she probably didn't go very far.

All of this data basically suggests to me

that they are giving birth in the vicinity,

just probably somewhere else,

offshore, maybe in a bay or mangrove, but definitely within the vicinity.

It's the first evidence

that there may be a manta pupping ground close by,

perhaps even in this estuary just 15 miles from Andrea's base.

There are no other known pupping grounds in the world.

With each new discovery,

this remarkable stretch of coast becomes ever more precious.

Andrea is now in talks with the Mozambique government

to set up a marine reserve at Tofo.

But the future for her newly-discovered giants

is far more uncertain.

It is terribly frightening

that something as beautiful and important as a manta ray

could ever be brought to the brink of extinction.

To have found a new species in this modern day is remarkable.

To lose them to unregulated fishing and to Chinese medicines

would be a tragedy.

I'm not quite sure what the future holds for them.

I believe that they need to be protected,

and certainly off the African coastline,

I will not leave until I see that they are.