Natural World (1983) s29e03 Episode Script

WOMAN: 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.
NARRATOR: This chance meeting changed the course ofAndrea Marshall's life.
ANDREA: 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 see 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 ofAndrea's life living with mantas.
Tofo Beach, Mozambique, where the Indian Ocean meets the east coast ofAfrica.
And it's here, on this wild, inaccessible stretch of coast, that Andrea lives and works.
ANDREA: 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, slightly to the left, would be good.
Do me a favour - if you see pregnant ones down there, just keep a track of how many 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 among 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.
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.
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.
ANDREA: 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 theyjoin 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 really quite exciting because they're 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're 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.
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 swell, short distance between the waves.
It's not ideal at all.
It's actually quite dangerous.
With waves of up to three metres, no coastguard, and the nearest doctor 30 miles away, there's no room for error.
ANDREA: You know, you've got to get out.
I mean, there's no harbours to launch from here, 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 seabed.
For the next 1 2 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's 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 almost on 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.
Mantas usually give birth to a single pup after a 1 2-month pregnancy.
But, in another manta first, Andrea's found it 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 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.
(SPEAKS IN MOZAMBICAN LANGUAGE) He says, in the summer, 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.
And it's notjust mantas that are being hauled in.
We know that Chinese syndicates along this coastline buy shark fins for quite a lot of money.
But they're very secretive about who they sell it 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're 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 forjust a 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 seven and a half metres, they were not only much larger than the reef mantas, but their markings were also much more pronounced.
ANDREA: 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 ofyears 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 visits to the Mozambique coast, that remains a mystery.
I have such a hunch that they are long-distance swimmers.
I feel that they're 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? That was absolutely spectacular Guy Stevens, from the Save Our Seas Maldivian Manta Ray Project, has been studying the mantas here for four years.
I just got a call from the guys out there, and there's about three whale sharks and 1 00 mantas.
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.
ANDREA: Look at them! Oh, there's one.
- There's one! Oh, wow! - Right here.
Look at him! Wow! There's so many.
There's heaps right there.
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 down there, as well.
- They're all the way down to the bottom.
- Yeah, right to the bottom.
- That is incredible! - As many as you can see up here, the whole water column will be full, down to the bottom.
That is amazing.
- Can we get in and start snorkelling? - Yeah.
Let's go.
Nowhere else in the world do mantas gather together in such huge numbers.
Within minutes, more than 1 00 arrive in the lagoon.
All are reef mantas.
The giants are nowhere to be seen.
ANDREA: I'd never actually been in a situation like that with mantas before.
I've never seen so many in one location, and 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.
It's likely the plankton, trying to escape the mantas circling above, have sunk down and got trapped on the seabed.
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, huh? - Oh, wow! That was sensational! Being able to look at all those mantas! That had to have been the best dive I've ever done in my life, I really would think.
I was dancing with them! It was just incredible.
I know that I didn't see any of the giants down there today.
Did you? No.
No, not today.
And that's not surprising for me.
I expect You know, 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, they won't associate.
So if you have a chain of mantas you'll never get the larger species, the giant mantas, actually interacting with the others.
As the light begins to fade, it's time to make the one-hourjourney back to Guy's base.
But the day's work isn't over yet.
GUY: So you can just about make out the cluster of spots there.
ANDREA: OK.
- GUY: One, two, three, four, five, six - Seven in a circle.
And then it goes off to a Over the past three years, Guy has recorded ten giants in the Maldives.
That's hard to say, you know By comparing the spot patterns of the Maldives and the Mozambique giants, they're hoping to find a match.
If they find a positive ID, it will prove the giants are travelling large distances.
- Can we zoom in on that a little bit? - Yeah.
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.
All right.
- On to the next one.
- On to the next one.
Wow! That's very, sort of, dramatic markings, huh? Dawn on day two ofAndrea's trip, and the photo comparison work is yet to find a match.
But, with more than 70 ofAndrea'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 of the tide - A little bit more experienced, huh? - 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 1 7 kilos of plankton a day.
As the mantas begin to disperse, the world's largest fish arrives.
Growing up to 1 2 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.
ANDREA: I had an amazing week here in the Maldives.
I am 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.
NARRATOR: 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 notjust 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 attentions of this tiny fish the butterfly fish.
Andrea has found they specialise in bite wounds.
Madonna, a female Andrea's known for more than five years, has a fresh injury on her flank.
By nibbling her wound, the butterfly fish removes dead tissue, preventing infection, making the difference between life and death for Mozambique's mantas.
Butterfly fish 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 giants mantas, when they're around, are frequent visitors to these cleaning stations, too.
But, with no sign of any today, Andrea willjust 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 that you don't see other places in the world.
Most people are reporting mantas cleaning for small periods of time - two hours, maybe, 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 the 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.
Two weeks later, and a full eight weeks since she last laid eyes on a giant manta, Andrea's luck looks like it's finally changing.
I'm really excited.
One of the dive operators just called.
They say there are mantas on the reef.
I don't know which ones, but they could well be giants, so we've prepped the boats and I'm 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, it's a giant.
Far more wary of humans than their smaller reef cousins, getting close to a giant is not going to be easy.
ANDREA: 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 that 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! Phew! 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: Simon.
- No, not Simon.
(THEY LAUGH) 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 onto Google and type in "manta products", you'll 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 Southeast 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'sJune, and the satellite data that could be the key to the giants' survival is finally in.
Cook's tag released early afterjust 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 1 50 metres for half of herjourney.
Why remains a mystery.
Magellan's tag stayed on for the full 60 days, and she made an incrediblejourney.
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 thejourney is enormous.
It means protecting giants like Magellan will need international co-operation.
As Andrea's year draws to a close there's a breakthrough for Tofo'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 a 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 1 5 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,