Oceans (2008) s01e05 Episode Script
Indian Ocean
They cover two thirds of our planet, they hold clues to the mysteries of our past and they're vital for our future survival, but the secrets of our oceans have remained largely undiscovered.
I am with a six gill shark.
Yes, yes! Explorer Paul Rose is leading a team of ocean experts on a series of underwater science expeditions.
For a year, the team has voyaged across the world to build up a global picture of our seas.
We are doing some pretty uncharted research here.
That is psychedelically purple! We're here to try and understand the earth's oceans, and put them in a human scale.
Our oceans are changing faster than ever.
I've never seen ice like this before.
There's never been a better time to explore the last true wilderness on earth.
We're about to see one of the most remarkable creatures in the Indian Ocean.
This is the only way we can get there.
Dive of a lifetime.
It won't be very easy.
This expedition will explore the third largest body of water on earth, the Indian Ocean.
More than 6,000 miles wide, it covers 13% of the world's surface.
It's home to 5,000 species of fish, many unique to this sea.
But it's an ocean on the edge.
Global pressures like climate change and over-fishing threaten to push it to a tipping point.
The team has come to the Western Indian Ocean to find out what effect these changes are having.
Environmentalist Philippe Cousteau is the grandson of ocean pioneer Jacques Cousteau.
He'll be investigating the threat to one of these waters' greatest predators.
By removing them in such large numbers, that has drastic impacts on all the other species underneath it.
Maritime archaeologist Dr Lucy Blue will experience the treacherous effects of the unpredictable currents here.
She hit this reef behind us, and then broke her back.
And marine biologist and oceanographer Toni Math will explore what can be done to save this pristine wilderness.
What we're looking at here is almost the Indian Ocean equivalent of a garden centre.
The expedition begins off the southern coast of Mozambique.
Paul and Toni have come here in search of the largest population of manta rays in the world.
We actually stand a chance here of being right alongside or underneath or right with these huge mantas.
I mean, some of them are about five or six metres.
- Eight metres.
- And there's talk of Eight metres.
I'm going for a giant eight-metre one.
Yeah? Eight metres across, this is a huge fish.
And it's very exciting indeed.
The team's been brought here by a mystery.
Seventy-six percent of the manta rays here have been attacked by sharks.
Attacks that should have decimated their numbers.
So how have they survived? Ready, ready, ready.
This is a beautiful site.
Just the visibility is a little bit murky.
It means that there's a chance that this water is very plankton-rich.
Here, close to the edge of the continental shelf, the plankton is fed by nutrient-rich water welling up from the deep.
It helps support an entire ecosystem, everything from giant potato groupers to poisonous lionfish.
Toni spots a sign they're in the right place to find mantas.
This is a very particular environment, a cleaning station.
The clue, these tiny fish.
There's a whole load of small cleaner wrasse that are waiting here.
They're very small, black and white-striped fish.
And they're waiting here until the mantas actually come here, so they can go up to their skin and pick off all of the parasites, which apparently feels really good on the mantas, as well.
They seem to like the sensation.
So it's a bit like going for hair and make-up, and a massage at the same time.
Looking for mantas.
I'm waiting for one to just sneak up on us from behind.
I keep imagining that I'm seeing them coming out of the gloom.
Toni, there's a manta! Come on.
Oh, my goodness! Oh, my goodness.
Boy, he's a whopper, Toni.
That is beautiful! Oh, my, so elegant.
The largest of the ocean's rays, mantas weigh up to one-and-a-half tons.
Yet they fly gracefully through the water using their wing-like fins.
They are bizarre-looking, with the horns at the front that gave them their name, the devil ray.
The horns can unroll to funnel food into the manta's mouth.
As the water passes through, spongy tissue traps the plankton they feed on.
But this one shows no sign of a shark bite, so it provides no clue as to how so many mantas survive these attacks, and time has run out.
We're both low on air, we've both got 50 bar, so we need to leave the bottom.
Unfortunately, in man versus manta, manta gets to win this one.
- Ready for me? - Yep.
There was a whopper behind Toni, and then we didn't see any more.
They have located a manta cleaning station, but they still haven't found what they're looking for.
The manta that we did see didn't have any injuries at all, and it's actually specifically the injuries that I'm really interested in going and having a look at.
With the light fading, they decide to try again in the morning.
Next day, weather and sea conditions are perfect, but Toni's not.
Oh, God.
I'm feeling really ropey, and I think I've either got a stomach bug or something or other, but Being sick underwater could be deadly.
With the masks we're using, which are full face masks, where the air comes from is right down in the front.
And if someone was to throw up in them, uh, you know, just that Then there's a reflex inhalation, isn't there? You just can't When if You breathe in.
That reflex inhalation, which can't be controlled, would bring stuff back into the throat.
There's a chance of being brought to the surface unconscious, but she's experienced enough to know that she just can't push it.
I think you should probably go, and I'll - Okay, yeah.
- I'll sit this one out.
I know we saw the mantas yesterday, but we didn't We didn't see specifically what it was that we came to see.
And I've read about this for years, and I'd be really interested to see To see the mantas and their cleaning behaviour.
It's just It's just frustrating, it's just really frustrating.
It's all up to Paul to find out what helps the injured mantas survive.
One, two, three, go! This time, the elusive mantas turn up straight away.
Look at this! Look at him go! Effortless but incredibly fast.
What's really fascinating is that the whole life on this reef changes when the mantas come and go.
All the attention is focused on them.
There's a shark bite, right there at the very back.
A shark attack like this is often fatal.
Oh, there's another one.
This one has two big bites out of the back end.
No one's sure why so many of these mantas have been attacked by sharks, but the location of their wounds is less of a mystery.
The manta's eyes are on the side of its head, leaving a blind spot directly behind.
Exactly where the shark's taken a bite.
I'm going to stay still here to see if he'll come my way.
Here he comes.
Just look how big he is compared to me.
And look just how well he moves.
And here's some cleaning.
Can you see the cleaning going on? That's what I dreamed we would see.
The yellow butterfly fish and the moon wrasse clean the wounds, removing dead and infected tissue.
It's a bit like pulling into a hospital and having your wounds dressed.
It stops infection forming.
More and more mantas arrive to have their wounds treated.
This could be why they're so resilient to shark attacks, a cleaning station with fish that target the shark wounds.
Behaviour that's rarely seen.
Really, really marvellous.
And then here comes this huge white manta.
It just kind of came over me, shark wounds on the back end, and it was smothered in cleaner fish.
Yeah, it was a great dive.
The cleaning station is a perfect example of how complex interactions make the world's marine ecosystems function.
Every living thing here is vital to this ocean's health, right up to its most extreme predators, sharks.
Next, the team will investigate what's happening to shark populations in this ocean, because sharks have turned from the hunters into the hunted.
Up until now, they have reigned supreme, and we are totally decimating their numbers.
And as the apex predator, by removing them in such large numbers out of these areas, that has drastic impacts on all the other species underneath it.
Over-fishing means shark numbers are plummeting.
Estimates suggest that each year as many as 73 million sharks are fished worldwide.
Twenty-six shark species are now listed as critically endangered.
Along this coast, shark fishing has grown dramatically over the past few years.
Philippe and Lucy have come on land to find out more.
This is Pomona in Mozambique.
Lucy and I are here to try and figure out kind of exactly what's happening and why and how.
And we're here early in the morning because this is the time they take the boats out to check their lines.
Little is known about shark fishing in this part of the world.
It's a unique chance to investigate it firsthand.
How many sharks does he catch? Between three and seven.
Wow.
So, is he from here? - He's from violoncellos.
- Oh, he's from violoncellos.
And he came here five years ago to fish.
Yeah, yeah.
But violoncellos is several hours away.
These fishermen are not from here, and the locals have no history of shark fishing.
This is something new.
These people have come or been brought here deliberately within some sort of structured organisation to specifically do this type of fishing, and that is most unusual.
The fishermen head out to check their three kilometres of line with its 65 separate hooks.
This one boat can land up to 1,000 sharks in a single year.
The fishermen return with their catch.
Two males, a little blacktop reef shark.
Both sharks are extremely young.
These aren't even anywhere near sexual maturity.
- They're little baby reef sharks.
- No, they are tiny.
Maybe two years old, a year old maybe, I think.
Yeah.
Sharks don't start reproducing till they're several years old.
When they do, most have few offspring, so catching young sharks like these is particularly worrying.
The worst thing for me is the fact that they're so small, you know, they haven't reached maturity, so there's no reproduction.
It's just, that's the end of this particular lineage.
But why is this industry growing so fast? The fins are the most valued part of the catch.
The essential ingredient in the Chinese delicacy shark fin soup, demand for which is growing rapidly.
Oh, this is pretty barbaric, actually, when you see it here, now.
It's (BLEEP).
Look at this, this little pile of fins for soup.
What a waste.
It's disgusting.
Look at this.
I mean, the only reason they sell the meat is because they can get a few cents for it.
I mean, it's worth nothing.
The only reason they're doing this is for those fins.
And there's a huge incentive.
How much will they sell those fins for? If they fish big one, bigger than the fish today, only the fins, they can make 50, 60 dollars.
- Fifty, 60 dollars for just the fin? - Yeah.
In a country where most people live on less than a dollar a day, six sharks can provide a year's income.
There you go.
Merry Christmas.
The fishermen show off a recent catch.
This pile of fins is worth a small fortune.
Where do they go now? - It goes to Maputo.
- Maputo, yeah.
And then they go out.
According to the fishermen, the big money means that regulations to control the export of fins are being ignored, so the trade flourishes.
Across the globe each year, millions of sharks continue to be wiped out.
It's scary when you think that so few individuals can come into a community like this, and take out so many animals.
- Yeah, yeah.
It's scary.
- I mean, over 1,000 animals a year Yeah.
Come out of this little cove.
I mean, this is not big.
Off four boats.
I mean, that is just It's shocking.
And then when you think of what's going on around the other shores of the Indian Ocean.
And to add insult to injury, shark fin has no flavour.
They have to flavour the soup with chicken broth, for God sakes.
I mean, it's just It's ridiculous.
It is absolutely ridiculous.
They've discovered that along this coast, shark fishing is an organised industry driven by fat profits.
It's just one part of a global trade that's decimating species and disrupting the balance of life throughout the Indian Ocean.
But over-fishing is not the only threat.
A changing climate will impact the ocean, altering its weather patterns.
These are dominated by heat transfer to and from the sea, but this is a complex process we know little about.
To try and find out more, the expedition will take part in a huge project run by scientists around the world, including the British Met Office.
They head north to the equator, where the heating effects of the sun have a powerful impact on the ocean and on the weather.
There's no clearer example of the link between the oceans and the climate than a tropical storm.
The energy in the Indian Ocean, here it is coming right at us.
Maybe a bit more than we'd ideally want right now.
- I don't know.
- But it's definitely coming.
This is a proper good pile of rain, and the sea's picking up a little bit.
Heavens have opened, it's bucketing down.
The captain advised us that this thing rolls quite a bit, and it's not unusual to have two feet of water swilling around on this deck, so Storms are powered by the constant exchange of heat and moisture between the ocean and the atmosphere, so understanding these processes is vital.
I've got Goosebumps! Just look at the sea, look at what the rain does to the sea.
It gets knocked down, it's fantastic.
The global project to gather data on the forces driving our weather is based around one vital piece of equipment.
Got to make sure that it's in there.
I can see it's been opened by customs.
You never know with these things.
It's supposed to be yellow and expensive-looking.
This is the Argo float.
Great.
A robotic buoy designed to gather readings on temperature and salinity from the depths of the ocean.
How this thing works is it descends to 1,000 metres and then comes back up again.
Uploads all of its data, and then sinks again.
This will be one of a vast network of floats transmitting their data to satellites to build up a dynamic picture of the ocean.
The plan is to launch it into an area that's poorly covered by Argo floats to help plug a gap in the survey network.
You should hear at some point Here we go, one.
It's working.
Now it's turned on, it's programmed to be deployed in just six hours.
There we go.
I can hear it! It runs for say, five, ten seconds, and then stops.
You can't put enthusiasm into projects like this unless you have some empathy and some interest in it.
And I do, I really do.
I mean, this is a Yeah, there it goes again.
En route to the launch site, the 6,000 pounds worth of equipment must be kept upright while it makes contact with the satellite network.
What sort of information is being collected in this? - It's temperature, salinity and depth.
- Right.
And then, of course, when it comes up, it's also position as well.
Yeah.
The data will help scientists worldwide to improve climate change prediction and tropical storm forecasting.
So how much longer do we have before it needs to be in the water? Well, it's six hours from when we turn it on, so it's now 1:10.
So, it's 4:50.
But the journey is taking longer than expected.
It would suit us better, I think, if we could be on the eastern side of the target area, where it's deeper.
Just a bit twitchy about Everything seems to happen just once, you know? The plan is for Paul to be in the water when the float is launched, to make sure it deploys correctly.
All systems go, and we've got 45 minutes to go.
It took a little bit longer to get here than we thought.
As you can see, I'm not dressed for the dive yet.
Probably just can't afford to be loafing at the moment.
Far from land, with no reference points to gauge position and depth, dive safety supervisor Richard Bull is concerned about Paul's dive into the big blue.
What I'm worried about is just sinking down without noticing it.
- Yeah.
- Because you get to a point where you're so deep, you can't see the surface, you can't see the bottom, you can't see that way and you can't see that way.
You can't tell which is up and which is down.
Yeah.
It'd be easy to do on this dive, you're right, because I'm just watching that yellow float.
Okay, we're getting late.
We're going to miss it, mate.
The float is timed to begin its first descent in just a few minutes.
Lucy is in charge of the crane.
You know yourself when you're handling a crane.
"You know yourself when you're handling a crane.
" I have to point out this is the first time I've done any crane handling.
This over here.
I'm really, really concerned about it hitting the side of the boat, though.
There you go.
A tiny bump against the metal hull could dent the casing, creating a weak spot that might rupture deep below the surface, where the water pressure will reach 200 times atmospheric pressure.
Five minutes, five minutes.
The rolling of the boat is also a problem for Paul.
I'm just swimming out of the way here, because our dive boat is right there.
I don't want to bank myself into it, and he's going to have to start positioning soon.
And that propeller's going to start going round, so I want to get out of the way.
I have to make a note of a number of things so that the Met Office have an understanding of the sort of basic sea state when the Argo's launched.
Knocks and bangs against the side of the vessel, apart from the initial swing that I induced, I think it was fine.
God, I'm shaking a bit, actually, because I don't want to mess it up.
You've only got one go, haven't you? You can't take two on this one.
But the descent time comes No, it's still there.
Look.
And goes.
That is Oh, no! I mean, if it doesn't go down in the next minute or so, then there could potentially be a problem.
It's not ready just yet.
Another couple of minutes? It hasn't sunk yet.
Finally, the launch begins.
Five, four, three, two, one.
Wow, there it goes! I'm waving goodbye to it on its four-year mission.
If it works, it'll help scientists gain a better understanding of the Indian Ocean monsoons.
It goes down 1,000 metres, and then 2,000 metres.
It comes to the surface repeatedly, up to 150 times for four years solid.
I can just see it, look.
You can just pick her out.
In 10 days, it should surface and transmit back to base for the first time.
Only then will the team know if the launch has succeeded.
It's gone! We're now underway for the southern coast of Zanzibar, the south-western tip of Zanzibar.
It's a brilliant feeling when even just You just mention the name Zanzibar to me, and I want to go there.
The team takes the opportunity to go ashore.
It's such a popular game and it's such a great game, and I think we have a winner.
Okay, got it.
- Okay, thank you very much.
- Thank you very much, thank you.
- Welcome again.
- Good, good, very happy with that.
With coastal development and over-fishing, human pressure on this sea is increasing.
So for the next mission, the team wants to see how that's impacting on one of the ocean's most precious ecosystems.
Environmentalist Philippe heads out with Lucy to check on the health of the Indian Ocean's world-famous coral reefs.
Worldwide, coral reefs are vital to the lives of a billion people who rely on them for food and income.
And they're home to a vast variety of marine life.
But the reefs may have reached a tipping point.
I have to be honest with you, I'm a little disappointed.
I'm not seeing the abundance of fish life that I'd expect here.
It just seems a little light to me, and that's kind of disappointing.
For three generations, Philippe's family has been documenting this ocean's threatened habitats.
Having grown up with images of my grandfather's films and my father's films, back in 1948, and you look at that, even though it's in black and white, it's like an amazing forest, just Richness is unparalleled.
And you go back to those same places today and it's just a desert.
Coral reefs are disappearing at such a scary rate.
Across the globe, 25% of coral reefs are under threat.
Philippe spots what's attacking this reef, one of its most voracious predators.
Wow, look at that.
That's a crown of thorns, right? It's enveloping that piece of coral.
The crown of thorns starfish eats the coral alive.
They can eat up to 16 or 17, maybe even 18 or more square feet of coral reef a year.
You can see right there that they take their stomach, literally, and turn it inside out when they get onto coral, and then start to eject all these stomach enzymes all over it.
It oozes out over the coral and liquefy it, and then they just suck it up.
It's kind of nasty.
Recently, a hundred-fold increase in the numbers of crown of thorns has devastated local reefs.
It may have been caused by people over-fishing its predators.
They are very, very prolific.
These guys are just wiping coral out.
But killing crown of thorns is tough.
Cut them in two, and both halves can survive.
The only ways to get rid of them, inject them with poison or bag them up and take them away.
We want to actually remove these from the reef, because these guys are just wiping coral out.
Oh, look at it reacting.
We're still finding more and more of them all over the seabed, and you can actually just see the way they're sort of moving over the surface of the coral.
Together with other factors, like warming seas, this has contributed to the destruction of over 22% of the reefs in the Southwest Indian Ocean alone.
But there is still hope.
Toni and Philippe head off to discover how damaged coral reefs could be revived using a new scientific technique.
Leading the work here is Tanzanian scientist Massage Omega.
- Hello, I'm Toni.
- Toni.
- Nice to meet you.
- I'm Omega.
- Omega, Philippe.
- Philippe, nice to meet you.
- Thank you for coming.
- Hello, everybody, how are you? Omega's working on a project around Mumbai, which is just, to me, is a great example of really innovative science, and it's the first time that this methodology has been used in the Indian Ocean.
They gear up to visit Omega's laboratory, not on land but about 10 metres beneath the water's surface.
Go, Omega! Go, Philippe! It's a facility which could hold an answer to saving the coral reefs, a man-made coral garden.
What we're looking at here is almost the Indian Ocean equivalent of a garden centre.
In this whole nursery, there are about 9,200 individual little pieces of coral.
These little bits of coral, or nubbins, are taken from a mother colony from a different location and moved into this area, where they're basically grown.
It's a little bit like pruning.
The plan is to help save endangered reefs by transplanting living coral into them.
But direct transplantation has had little success, so Omega and his team are growing young coral in this protected environment till it's strong enough to survive being transplanted.
The first thing Omega does is collect young coral from a healthy reef.
And then he cuts coral nubbins off, kind of like taking pruning of a tree, and he puts them into these small, little rubber tubes.
Although it doesn't look like much, that little section of coral is actually alive.
The coral will grow from what looks like something that potentially doesn't amount to much.
But that could spell the survival of the coral reefs in some areas where they've been decimated in the Indian Ocean.
The coral can't be left on its own.
It needs constant care.
So Omega is weeding the garden.
This blanketing algae will smother the coral, so by removing all of this, these corals have an opportunity to grow in as healthy a habitat as possible.
Once the nubbins have spent about 10 months here, they're ready for transplantation.
If this technique is successful, it could help regenerate damaged reefs, not just in the Indian Ocean but across the entire world.
It's really encouraging to see that that kind of methodology is actually being used in areas such as this, where there obviously isn't a huge amount of money to invest in marine science.
But this technique is so simple and so cheap, basically, it just requires an awful lot of manpower.
I mean, we've already lost at least 25%%% of the world's coral reefs.
So, now, because we're taking an active role in their destruction, this is an opportunity to take an active role in their restoration, and it's a very hopeful, hopeful time right now.
As the day ends - I planted coral today.
- Yet! - These little fingers of greenness.
- Oh, cool.
It's a chance to plan the next stage of the expedition.
So, yeah.
So, up here, this is I've not been here before.
This looks fantastic.
Very, very good.
People have been living on the shores of the Indian Ocean for over 100,000 years.
How they've related to this vast body of water is the speciality of maritime archaeologist Lucy Blue.
I'm trying to work out how different people, different cultures, would have approached this sea, this ocean.
Obviously, there are certain parameters that they were constrained by, so the winds and the currents.
What were the challenges that they faced? Trade and migration in the Indian Ocean has been dominated by the powerful currents that flow uninterrupted for thousands of miles across it, before crashing into the East African coast.
All right, so this gives you a really good idea of the way that the currents are moving along this coastline.
Particularly this East African coastal current, or the Zanzibar one.
The combination of the currents and the winds have completely dictated the way that people have manoeuvred around, particularly this part of the Indian Ocean.
Lucy believes there's much to learn from mankind's battles with these treacherous currents.
So the expedition's heading for a site of particular interest to her, the wreck of a ship sunk 40 years ago in the unpredictable waters of the Indian Ocean.
To avoid the same fate, the expedition ship will have to be extremely cautious.
When I was talking with the skipper earlier, he was saying, you know, "This is actually quite a treacherous area.
" I mean, we're not actually mooring up because the currents are quite complex and unpredictable.
But when they reach the site, they find they aren't the only ones interested in it.
A group of local salvagers are already here trying to break up the ship and recover valuable metals.
They're none too pleased to have competition.
All right, folks, we've got a little bit of a situation out there.
It's a bunch of guys that are trying to cut off the propeller with welding gear.
I don't know whether they think that we're going to try and poach their propeller from them.
It's big and it's worth a lot of money, but they're protecting themselves with spear guns.
- Okay.
- And, Scott, he actually had one of them go to him As expedition leader, Paul's worried about the safety of his team.
But for Lucy, this is an example of a worldwide problem she often faces, the destruction of archaeological sites.
There's nothing we can do.
I mean, if they start ripping off the portholes and the props and all the rest of it, there's nothing for anybody to see.
There's nothing for anybody to learn about it.
I'm actually rooting for them.
- Why? - Because I feel Then we could end up having some contretemps.
I feel that the ship is in their waters, and that propeller and all, any of the bits they can use, will sustain their livelihood better than tourists coming and looking at it.
Really, I'm not sure about that, though, because you have That thing is there for an instance.
They are going to reap an immediate reward.
- Hmm.
- It's just condoning that whole activity, encouraging other people do to it on wrecks throughout the world, and then it's gone.
Whichever one of you is right, it's not the immediate problem.
- No.
- The immediate problem is that they've got spear guns and they exhibited very threatening behaviour.
The situation is tense.
A crew member who speaks Swahili has gone over to explain that the team are just here to dive the wreck.
Mike, this is Richard.
Come in.
Over.
The translator's just talked with the salvage crew, and they've given us permission to dive on the site.
Mike, that's fantastic.
The salvagers stop diving.
The team can get to work.
One This is what the salvagers are after, the remains of the Proportion.
Wow, it's absolutely huge! After 40 years on the bottom, there's still a lot left of this 94-metre cargo ship.
It's clear from the chains and pulleys that the salvagers are well on their way to removing the huge bronze propeller.
Bronze scrap is worth thousands of pounds per ton.
It's going to be a lot of work to shift this, and ultimately it's setting a precedent for just ripping shipwrecks apart, regardless of whether they're 40 years old or 400 years old.
All shipwrecks tell the story of a moment in time when a combination of circumstances came together to create a catastrophe.
So the Proportion sunk here in 1967, early in the evening, carrying wheat from Romania to Jedi.
The ship was meant to go via the Suez Canal, but with the Arab-Israeli war in full swing, that was closed, forcing the Proportion to travel right round Africa.
For weeks, the voyage went well.
Then, with just days to go, things went badly wrong.
We believe that they'd lost their radar and their echo-sounder and they were basically travelling in very unfamiliar waters.
So they had to resort to compass and sextants and navigating by the stars in currents which they didn't understand.
Just imagine the sense of terror coming up on this reef.
Completely lost, the noise, panic.
She hit this reef behind us and then broke her back, sprawling down here onto the sand.
Somehow, everyone on board survived, but the reef and the currents battered and sank the Proportion.
Considering she's only been down 40 years, it's an amazing amount of marine life, though, here.
The Proportion may be home to many fish, but Lucy is shocked at how the salvagers are wiping out precious historical information.
I mean, they've got rigs up there.
They've got, you know, the whole works.
- Is it pretty much free game? - It's free game.
It's free game at the moment, yeah.
It's free game.
This is not in the marine reserve area, so there's nothing in terms of the conservation of this particular Zone that says And anyway, I would imagine it's very difficult to police.
I mean, I know how difficult it is in the UK.
My job on a daily basis is trying to battle against the problems of treasure hunters and salvage work, and when you do meet it face to face, it You can't but, you know, despise it and everything it represents.
Ten days ago, the expedition launched the Argo float to monitor the depths of the Indian Ocean.
There it goes.
I'm waving goodbye to it on its four-year mission.
It's now scheduled to surface and upload its first data.
But has its mission succeeded? - So this is - Moment of truth.
Well, it is the moment of truth, because with any luck - First of all - Yeah.
If we can get this through, we're going to figure out if the Argo actually worked, so hang on.
- Is that the map? - That's it.
That's it? That's the transmit? Yeah, it is.
So it's working.
The map tracks the float's position from where Paul first powered it up to when it surfaced and successfully uploaded its data.
This must be us going out.
This is when we deployed it.
- Yeah, just about, gosh - And it sank.
And this is it here, so you see, it obviously didn't get stuck.
It's going on the expected track, which is north and then northwest.
And it's come up and it's sent the right expected data up.
- So, the blooming thing worked.
- So, you feel the flutter of pride that it actually worked.
The big thing for me, and it does excite me, is that it's real-time data.
So they're all coming up and down, all sending up temperature, salinity, depth and where they are.
For me, it's the fact that there are 3,000-plus of the Argo floats all over the world, so our little float is basically representative of just this huge global data search.
Scientists are already using the data to look into the future and determine how our oceans and climate might change over the next decade.
With just two days left, the team wants to see how one of the ocean's most elusive residents is faring in these fast-changing waters.
The hunt brings them here, to the Lazaretto Archipelago, a chain of islands 20 miles off the coast of Mozambique.
The islands are hammered by the powerful waves and winds that have shaped these 100-metre-high dunes built up over thousands of years.
You really get a sense of the power of the wind and the ocean here.
Just looking out over the Indian Ocean, next stop, Australia.
All that power of the Indian Ocean just slams into this coast, and it stings, it kind of stings the back of your legs.
- Stings? - Like you're getting sandblasted.
- Slamming into us at the moment.
- It is slamming.
The Lazaretto Archipelago acts as a barrier, absorbing the fury of the Indian Ocean and protecting the 20-mile stretch of water on the other side.
Toni believes it's here that the team may find a sensitive barometer of the health of the Indian Ocean, one of its rarest animals.
So this is the dugong.
With the best Latin name ever, the Dugong dugong.
A really bizarre kind of hybridisation between the dolphin tail Yeah.
And then you've got sort of a cow-like/elephantine front end.
They grow up to about 3.
4 metres, so they're a fairly decent size.
Dugongs once thrived in this part of the Indian Ocean, but not any more.
Hunting and entrapment in fishermen's nets have drastically reduced their numbers.
So how well is this tiny population doing? Right here is pretty much the last viable population of dugong in the Western Indian Ocean.
So we've come to this specific area to see if we can find them, and to be honest, it would be an absolute joy, and I think something really special if we did.
But finding them, I think, is going to be a bit of a nightmare.
Dugongs have always been mysterious.
Their unusual body shape probably inspired the myth of the mermaid.
They have what's called a bursiform body, combining the flute tail of a fish with four limbs and a snout-like head.
This isn't the first time Toni's searched for them.
She knows how tough it is looking for a few dugongs in a very big ocean.
I spent a month hunting for dugong and I didn't see a single flipping whisker.
So if we do see them, we are going to be exceptionally lucky.
Ready then, team? If they can find them, it will be a rare chance for Toni to see how well they're coping.
They head for an area they've been told has a high density of dugongs, but Toni is not convinced.
A high density is a little bit of a misnomer and it's a slightly misleading name, because "high density" suggests that there's loads of them swimming around.
But in actual fact, that's not true.
It just means that more of them have been spotted in that location than anywhere else.
Toni still hopes to find a few, but dugongs are notoriously timid.
The plan is to just cut the engines.
It's going to have to be a really, really quiet and slow operation, so we don't freak them out, 'cause as soon as they hear the boat noise or hear splashing, they're just going to be gone.
If we smell a dugong, it's going to be miraculous.
One of the crew believes they've seen a dugong, so Toni takes a chance and jumps in to try and get close.
But underwater, the visibility is terrible.
Finding the dugongs will take more than this.
Well, it just shows you how bad the visibility is, because we didn't see fiddly.
Paul is going to try and spot them from the air and guide Toni to them.
These things really are hard to find, so this is our secret weapon.
And Toni's really counting on me up there, she's really counting on me being able to see them from about 500 feet, and I can steer her in.
Delta Echo Oscar victor Charlie is entering and vectoring.
There's a bunch of goats ahead of us, so what we're going to try and do is get airborne before we hit any of the goats.
Toni, Toni, it's Paul in victor Charlie now.
Copy.
Paul, this is Toni.
Over.
We can see you.
If you just follow us now, follow this bearing.
Great, keep us posted.
Out.
Suddenly, Paul sees a grey smudge in the water.
There's a dugong! Dugong dugong, yeah.
Right there! It's coming round.
The wing's in the way, but you'll see him in a minute.
We've got a dugong.
In fact, it's a small group.
Toni, Toni, we are over Get your foot down, because we're over them right now.
That's great news, Paul, great news.
We'll make our way towards you now.
We head straight for the aeroplane, straight for the aeroplane.
I can sense dugong.
I can sense them.
Paul, Paul, which direction are they travelling in.
Over? The track you're on, they'll be right ahead, right ahead.
They're kind of Running parallel with you.
Yeah, at the surface.
They are at the surface.
Oh, I can see them! Toni, can you see them? They're right in front of you.
Over.
Roger that.
I can see them, Paul, I can see them.
I'm so happy that we've seen them, 'cause I didn't think I didn't think we were going to at all, actually, if truth be told.
Seeing the group of dugongs is positive evidence that the population here is surviving.
But then Paul spots something even more encouraging, a sign that the dugongs here may be in better shape than they'd thought.
And a cub.
You see the cub as well? Right there, right there.
Fantastic news, look at them.
Three and a half dugong! The dugongs are doing more than surviving.
They're reproducing.
It's incredibly good news.
That's that.
That's all right, isn't it? The team's success has come just in time.
We're off, we're getting so low on fuel.
Over.
Okay, Paul.
Thank you so much.
We did see the dugong, which is absolutely fantastic.
All right, guys.
Here we go.
It's the end of their Indian Ocean odyssey.
It was excellent.
They've journeyed through seas that support some of the most varied marine life on the planet.
Diving with the manta rays, one of the finest dives I've ever had.
You know, I've done over 6,000 of them.
The most special part of this expedition for me has been getting a chance to see this part of the world.
The diversity that's here, the diversity of life and abundance of life from an ocean perspective, because coral reefs here in the Indian Ocean are some of the most bio diverse in the world.
Coming on this project and seeing, you know, looking at the marine life as well as the cultural context has just reinforced to me how little we know about this ocean.
The Indian Ocean is so rich.
I'm worried about it, though.
So far, the Indian Ocean is holding its own.
But in a world that's being transformed so rapidly, how much longer can it cope? Next time, the team continues to explore the Indian Ocean.
They'll investigate how marine creatures can help predict extreme weather.
They'll dive the remains of a medieval village.
See this design here? That's got to be Oriental.
And try to protect the largest fish in the sea.
I am with a six gill shark.
Yes, yes! Explorer Paul Rose is leading a team of ocean experts on a series of underwater science expeditions.
For a year, the team has voyaged across the world to build up a global picture of our seas.
We are doing some pretty uncharted research here.
That is psychedelically purple! We're here to try and understand the earth's oceans, and put them in a human scale.
Our oceans are changing faster than ever.
I've never seen ice like this before.
There's never been a better time to explore the last true wilderness on earth.
We're about to see one of the most remarkable creatures in the Indian Ocean.
This is the only way we can get there.
Dive of a lifetime.
It won't be very easy.
This expedition will explore the third largest body of water on earth, the Indian Ocean.
More than 6,000 miles wide, it covers 13% of the world's surface.
It's home to 5,000 species of fish, many unique to this sea.
But it's an ocean on the edge.
Global pressures like climate change and over-fishing threaten to push it to a tipping point.
The team has come to the Western Indian Ocean to find out what effect these changes are having.
Environmentalist Philippe Cousteau is the grandson of ocean pioneer Jacques Cousteau.
He'll be investigating the threat to one of these waters' greatest predators.
By removing them in such large numbers, that has drastic impacts on all the other species underneath it.
Maritime archaeologist Dr Lucy Blue will experience the treacherous effects of the unpredictable currents here.
She hit this reef behind us, and then broke her back.
And marine biologist and oceanographer Toni Math will explore what can be done to save this pristine wilderness.
What we're looking at here is almost the Indian Ocean equivalent of a garden centre.
The expedition begins off the southern coast of Mozambique.
Paul and Toni have come here in search of the largest population of manta rays in the world.
We actually stand a chance here of being right alongside or underneath or right with these huge mantas.
I mean, some of them are about five or six metres.
- Eight metres.
- And there's talk of Eight metres.
I'm going for a giant eight-metre one.
Yeah? Eight metres across, this is a huge fish.
And it's very exciting indeed.
The team's been brought here by a mystery.
Seventy-six percent of the manta rays here have been attacked by sharks.
Attacks that should have decimated their numbers.
So how have they survived? Ready, ready, ready.
This is a beautiful site.
Just the visibility is a little bit murky.
It means that there's a chance that this water is very plankton-rich.
Here, close to the edge of the continental shelf, the plankton is fed by nutrient-rich water welling up from the deep.
It helps support an entire ecosystem, everything from giant potato groupers to poisonous lionfish.
Toni spots a sign they're in the right place to find mantas.
This is a very particular environment, a cleaning station.
The clue, these tiny fish.
There's a whole load of small cleaner wrasse that are waiting here.
They're very small, black and white-striped fish.
And they're waiting here until the mantas actually come here, so they can go up to their skin and pick off all of the parasites, which apparently feels really good on the mantas, as well.
They seem to like the sensation.
So it's a bit like going for hair and make-up, and a massage at the same time.
Looking for mantas.
I'm waiting for one to just sneak up on us from behind.
I keep imagining that I'm seeing them coming out of the gloom.
Toni, there's a manta! Come on.
Oh, my goodness! Oh, my goodness.
Boy, he's a whopper, Toni.
That is beautiful! Oh, my, so elegant.
The largest of the ocean's rays, mantas weigh up to one-and-a-half tons.
Yet they fly gracefully through the water using their wing-like fins.
They are bizarre-looking, with the horns at the front that gave them their name, the devil ray.
The horns can unroll to funnel food into the manta's mouth.
As the water passes through, spongy tissue traps the plankton they feed on.
But this one shows no sign of a shark bite, so it provides no clue as to how so many mantas survive these attacks, and time has run out.
We're both low on air, we've both got 50 bar, so we need to leave the bottom.
Unfortunately, in man versus manta, manta gets to win this one.
- Ready for me? - Yep.
There was a whopper behind Toni, and then we didn't see any more.
They have located a manta cleaning station, but they still haven't found what they're looking for.
The manta that we did see didn't have any injuries at all, and it's actually specifically the injuries that I'm really interested in going and having a look at.
With the light fading, they decide to try again in the morning.
Next day, weather and sea conditions are perfect, but Toni's not.
Oh, God.
I'm feeling really ropey, and I think I've either got a stomach bug or something or other, but Being sick underwater could be deadly.
With the masks we're using, which are full face masks, where the air comes from is right down in the front.
And if someone was to throw up in them, uh, you know, just that Then there's a reflex inhalation, isn't there? You just can't When if You breathe in.
That reflex inhalation, which can't be controlled, would bring stuff back into the throat.
There's a chance of being brought to the surface unconscious, but she's experienced enough to know that she just can't push it.
I think you should probably go, and I'll - Okay, yeah.
- I'll sit this one out.
I know we saw the mantas yesterday, but we didn't We didn't see specifically what it was that we came to see.
And I've read about this for years, and I'd be really interested to see To see the mantas and their cleaning behaviour.
It's just It's just frustrating, it's just really frustrating.
It's all up to Paul to find out what helps the injured mantas survive.
One, two, three, go! This time, the elusive mantas turn up straight away.
Look at this! Look at him go! Effortless but incredibly fast.
What's really fascinating is that the whole life on this reef changes when the mantas come and go.
All the attention is focused on them.
There's a shark bite, right there at the very back.
A shark attack like this is often fatal.
Oh, there's another one.
This one has two big bites out of the back end.
No one's sure why so many of these mantas have been attacked by sharks, but the location of their wounds is less of a mystery.
The manta's eyes are on the side of its head, leaving a blind spot directly behind.
Exactly where the shark's taken a bite.
I'm going to stay still here to see if he'll come my way.
Here he comes.
Just look how big he is compared to me.
And look just how well he moves.
And here's some cleaning.
Can you see the cleaning going on? That's what I dreamed we would see.
The yellow butterfly fish and the moon wrasse clean the wounds, removing dead and infected tissue.
It's a bit like pulling into a hospital and having your wounds dressed.
It stops infection forming.
More and more mantas arrive to have their wounds treated.
This could be why they're so resilient to shark attacks, a cleaning station with fish that target the shark wounds.
Behaviour that's rarely seen.
Really, really marvellous.
And then here comes this huge white manta.
It just kind of came over me, shark wounds on the back end, and it was smothered in cleaner fish.
Yeah, it was a great dive.
The cleaning station is a perfect example of how complex interactions make the world's marine ecosystems function.
Every living thing here is vital to this ocean's health, right up to its most extreme predators, sharks.
Next, the team will investigate what's happening to shark populations in this ocean, because sharks have turned from the hunters into the hunted.
Up until now, they have reigned supreme, and we are totally decimating their numbers.
And as the apex predator, by removing them in such large numbers out of these areas, that has drastic impacts on all the other species underneath it.
Over-fishing means shark numbers are plummeting.
Estimates suggest that each year as many as 73 million sharks are fished worldwide.
Twenty-six shark species are now listed as critically endangered.
Along this coast, shark fishing has grown dramatically over the past few years.
Philippe and Lucy have come on land to find out more.
This is Pomona in Mozambique.
Lucy and I are here to try and figure out kind of exactly what's happening and why and how.
And we're here early in the morning because this is the time they take the boats out to check their lines.
Little is known about shark fishing in this part of the world.
It's a unique chance to investigate it firsthand.
How many sharks does he catch? Between three and seven.
Wow.
So, is he from here? - He's from violoncellos.
- Oh, he's from violoncellos.
And he came here five years ago to fish.
Yeah, yeah.
But violoncellos is several hours away.
These fishermen are not from here, and the locals have no history of shark fishing.
This is something new.
These people have come or been brought here deliberately within some sort of structured organisation to specifically do this type of fishing, and that is most unusual.
The fishermen head out to check their three kilometres of line with its 65 separate hooks.
This one boat can land up to 1,000 sharks in a single year.
The fishermen return with their catch.
Two males, a little blacktop reef shark.
Both sharks are extremely young.
These aren't even anywhere near sexual maturity.
- They're little baby reef sharks.
- No, they are tiny.
Maybe two years old, a year old maybe, I think.
Yeah.
Sharks don't start reproducing till they're several years old.
When they do, most have few offspring, so catching young sharks like these is particularly worrying.
The worst thing for me is the fact that they're so small, you know, they haven't reached maturity, so there's no reproduction.
It's just, that's the end of this particular lineage.
But why is this industry growing so fast? The fins are the most valued part of the catch.
The essential ingredient in the Chinese delicacy shark fin soup, demand for which is growing rapidly.
Oh, this is pretty barbaric, actually, when you see it here, now.
It's (BLEEP).
Look at this, this little pile of fins for soup.
What a waste.
It's disgusting.
Look at this.
I mean, the only reason they sell the meat is because they can get a few cents for it.
I mean, it's worth nothing.
The only reason they're doing this is for those fins.
And there's a huge incentive.
How much will they sell those fins for? If they fish big one, bigger than the fish today, only the fins, they can make 50, 60 dollars.
- Fifty, 60 dollars for just the fin? - Yeah.
In a country where most people live on less than a dollar a day, six sharks can provide a year's income.
There you go.
Merry Christmas.
The fishermen show off a recent catch.
This pile of fins is worth a small fortune.
Where do they go now? - It goes to Maputo.
- Maputo, yeah.
And then they go out.
According to the fishermen, the big money means that regulations to control the export of fins are being ignored, so the trade flourishes.
Across the globe each year, millions of sharks continue to be wiped out.
It's scary when you think that so few individuals can come into a community like this, and take out so many animals.
- Yeah, yeah.
It's scary.
- I mean, over 1,000 animals a year Yeah.
Come out of this little cove.
I mean, this is not big.
Off four boats.
I mean, that is just It's shocking.
And then when you think of what's going on around the other shores of the Indian Ocean.
And to add insult to injury, shark fin has no flavour.
They have to flavour the soup with chicken broth, for God sakes.
I mean, it's just It's ridiculous.
It is absolutely ridiculous.
They've discovered that along this coast, shark fishing is an organised industry driven by fat profits.
It's just one part of a global trade that's decimating species and disrupting the balance of life throughout the Indian Ocean.
But over-fishing is not the only threat.
A changing climate will impact the ocean, altering its weather patterns.
These are dominated by heat transfer to and from the sea, but this is a complex process we know little about.
To try and find out more, the expedition will take part in a huge project run by scientists around the world, including the British Met Office.
They head north to the equator, where the heating effects of the sun have a powerful impact on the ocean and on the weather.
There's no clearer example of the link between the oceans and the climate than a tropical storm.
The energy in the Indian Ocean, here it is coming right at us.
Maybe a bit more than we'd ideally want right now.
- I don't know.
- But it's definitely coming.
This is a proper good pile of rain, and the sea's picking up a little bit.
Heavens have opened, it's bucketing down.
The captain advised us that this thing rolls quite a bit, and it's not unusual to have two feet of water swilling around on this deck, so Storms are powered by the constant exchange of heat and moisture between the ocean and the atmosphere, so understanding these processes is vital.
I've got Goosebumps! Just look at the sea, look at what the rain does to the sea.
It gets knocked down, it's fantastic.
The global project to gather data on the forces driving our weather is based around one vital piece of equipment.
Got to make sure that it's in there.
I can see it's been opened by customs.
You never know with these things.
It's supposed to be yellow and expensive-looking.
This is the Argo float.
Great.
A robotic buoy designed to gather readings on temperature and salinity from the depths of the ocean.
How this thing works is it descends to 1,000 metres and then comes back up again.
Uploads all of its data, and then sinks again.
This will be one of a vast network of floats transmitting their data to satellites to build up a dynamic picture of the ocean.
The plan is to launch it into an area that's poorly covered by Argo floats to help plug a gap in the survey network.
You should hear at some point Here we go, one.
It's working.
Now it's turned on, it's programmed to be deployed in just six hours.
There we go.
I can hear it! It runs for say, five, ten seconds, and then stops.
You can't put enthusiasm into projects like this unless you have some empathy and some interest in it.
And I do, I really do.
I mean, this is a Yeah, there it goes again.
En route to the launch site, the 6,000 pounds worth of equipment must be kept upright while it makes contact with the satellite network.
What sort of information is being collected in this? - It's temperature, salinity and depth.
- Right.
And then, of course, when it comes up, it's also position as well.
Yeah.
The data will help scientists worldwide to improve climate change prediction and tropical storm forecasting.
So how much longer do we have before it needs to be in the water? Well, it's six hours from when we turn it on, so it's now 1:10.
So, it's 4:50.
But the journey is taking longer than expected.
It would suit us better, I think, if we could be on the eastern side of the target area, where it's deeper.
Just a bit twitchy about Everything seems to happen just once, you know? The plan is for Paul to be in the water when the float is launched, to make sure it deploys correctly.
All systems go, and we've got 45 minutes to go.
It took a little bit longer to get here than we thought.
As you can see, I'm not dressed for the dive yet.
Probably just can't afford to be loafing at the moment.
Far from land, with no reference points to gauge position and depth, dive safety supervisor Richard Bull is concerned about Paul's dive into the big blue.
What I'm worried about is just sinking down without noticing it.
- Yeah.
- Because you get to a point where you're so deep, you can't see the surface, you can't see the bottom, you can't see that way and you can't see that way.
You can't tell which is up and which is down.
Yeah.
It'd be easy to do on this dive, you're right, because I'm just watching that yellow float.
Okay, we're getting late.
We're going to miss it, mate.
The float is timed to begin its first descent in just a few minutes.
Lucy is in charge of the crane.
You know yourself when you're handling a crane.
"You know yourself when you're handling a crane.
" I have to point out this is the first time I've done any crane handling.
This over here.
I'm really, really concerned about it hitting the side of the boat, though.
There you go.
A tiny bump against the metal hull could dent the casing, creating a weak spot that might rupture deep below the surface, where the water pressure will reach 200 times atmospheric pressure.
Five minutes, five minutes.
The rolling of the boat is also a problem for Paul.
I'm just swimming out of the way here, because our dive boat is right there.
I don't want to bank myself into it, and he's going to have to start positioning soon.
And that propeller's going to start going round, so I want to get out of the way.
I have to make a note of a number of things so that the Met Office have an understanding of the sort of basic sea state when the Argo's launched.
Knocks and bangs against the side of the vessel, apart from the initial swing that I induced, I think it was fine.
God, I'm shaking a bit, actually, because I don't want to mess it up.
You've only got one go, haven't you? You can't take two on this one.
But the descent time comes No, it's still there.
Look.
And goes.
That is Oh, no! I mean, if it doesn't go down in the next minute or so, then there could potentially be a problem.
It's not ready just yet.
Another couple of minutes? It hasn't sunk yet.
Finally, the launch begins.
Five, four, three, two, one.
Wow, there it goes! I'm waving goodbye to it on its four-year mission.
If it works, it'll help scientists gain a better understanding of the Indian Ocean monsoons.
It goes down 1,000 metres, and then 2,000 metres.
It comes to the surface repeatedly, up to 150 times for four years solid.
I can just see it, look.
You can just pick her out.
In 10 days, it should surface and transmit back to base for the first time.
Only then will the team know if the launch has succeeded.
It's gone! We're now underway for the southern coast of Zanzibar, the south-western tip of Zanzibar.
It's a brilliant feeling when even just You just mention the name Zanzibar to me, and I want to go there.
The team takes the opportunity to go ashore.
It's such a popular game and it's such a great game, and I think we have a winner.
Okay, got it.
- Okay, thank you very much.
- Thank you very much, thank you.
- Welcome again.
- Good, good, very happy with that.
With coastal development and over-fishing, human pressure on this sea is increasing.
So for the next mission, the team wants to see how that's impacting on one of the ocean's most precious ecosystems.
Environmentalist Philippe heads out with Lucy to check on the health of the Indian Ocean's world-famous coral reefs.
Worldwide, coral reefs are vital to the lives of a billion people who rely on them for food and income.
And they're home to a vast variety of marine life.
But the reefs may have reached a tipping point.
I have to be honest with you, I'm a little disappointed.
I'm not seeing the abundance of fish life that I'd expect here.
It just seems a little light to me, and that's kind of disappointing.
For three generations, Philippe's family has been documenting this ocean's threatened habitats.
Having grown up with images of my grandfather's films and my father's films, back in 1948, and you look at that, even though it's in black and white, it's like an amazing forest, just Richness is unparalleled.
And you go back to those same places today and it's just a desert.
Coral reefs are disappearing at such a scary rate.
Across the globe, 25% of coral reefs are under threat.
Philippe spots what's attacking this reef, one of its most voracious predators.
Wow, look at that.
That's a crown of thorns, right? It's enveloping that piece of coral.
The crown of thorns starfish eats the coral alive.
They can eat up to 16 or 17, maybe even 18 or more square feet of coral reef a year.
You can see right there that they take their stomach, literally, and turn it inside out when they get onto coral, and then start to eject all these stomach enzymes all over it.
It oozes out over the coral and liquefy it, and then they just suck it up.
It's kind of nasty.
Recently, a hundred-fold increase in the numbers of crown of thorns has devastated local reefs.
It may have been caused by people over-fishing its predators.
They are very, very prolific.
These guys are just wiping coral out.
But killing crown of thorns is tough.
Cut them in two, and both halves can survive.
The only ways to get rid of them, inject them with poison or bag them up and take them away.
We want to actually remove these from the reef, because these guys are just wiping coral out.
Oh, look at it reacting.
We're still finding more and more of them all over the seabed, and you can actually just see the way they're sort of moving over the surface of the coral.
Together with other factors, like warming seas, this has contributed to the destruction of over 22% of the reefs in the Southwest Indian Ocean alone.
But there is still hope.
Toni and Philippe head off to discover how damaged coral reefs could be revived using a new scientific technique.
Leading the work here is Tanzanian scientist Massage Omega.
- Hello, I'm Toni.
- Toni.
- Nice to meet you.
- I'm Omega.
- Omega, Philippe.
- Philippe, nice to meet you.
- Thank you for coming.
- Hello, everybody, how are you? Omega's working on a project around Mumbai, which is just, to me, is a great example of really innovative science, and it's the first time that this methodology has been used in the Indian Ocean.
They gear up to visit Omega's laboratory, not on land but about 10 metres beneath the water's surface.
Go, Omega! Go, Philippe! It's a facility which could hold an answer to saving the coral reefs, a man-made coral garden.
What we're looking at here is almost the Indian Ocean equivalent of a garden centre.
In this whole nursery, there are about 9,200 individual little pieces of coral.
These little bits of coral, or nubbins, are taken from a mother colony from a different location and moved into this area, where they're basically grown.
It's a little bit like pruning.
The plan is to help save endangered reefs by transplanting living coral into them.
But direct transplantation has had little success, so Omega and his team are growing young coral in this protected environment till it's strong enough to survive being transplanted.
The first thing Omega does is collect young coral from a healthy reef.
And then he cuts coral nubbins off, kind of like taking pruning of a tree, and he puts them into these small, little rubber tubes.
Although it doesn't look like much, that little section of coral is actually alive.
The coral will grow from what looks like something that potentially doesn't amount to much.
But that could spell the survival of the coral reefs in some areas where they've been decimated in the Indian Ocean.
The coral can't be left on its own.
It needs constant care.
So Omega is weeding the garden.
This blanketing algae will smother the coral, so by removing all of this, these corals have an opportunity to grow in as healthy a habitat as possible.
Once the nubbins have spent about 10 months here, they're ready for transplantation.
If this technique is successful, it could help regenerate damaged reefs, not just in the Indian Ocean but across the entire world.
It's really encouraging to see that that kind of methodology is actually being used in areas such as this, where there obviously isn't a huge amount of money to invest in marine science.
But this technique is so simple and so cheap, basically, it just requires an awful lot of manpower.
I mean, we've already lost at least 25%%% of the world's coral reefs.
So, now, because we're taking an active role in their destruction, this is an opportunity to take an active role in their restoration, and it's a very hopeful, hopeful time right now.
As the day ends - I planted coral today.
- Yet! - These little fingers of greenness.
- Oh, cool.
It's a chance to plan the next stage of the expedition.
So, yeah.
So, up here, this is I've not been here before.
This looks fantastic.
Very, very good.
People have been living on the shores of the Indian Ocean for over 100,000 years.
How they've related to this vast body of water is the speciality of maritime archaeologist Lucy Blue.
I'm trying to work out how different people, different cultures, would have approached this sea, this ocean.
Obviously, there are certain parameters that they were constrained by, so the winds and the currents.
What were the challenges that they faced? Trade and migration in the Indian Ocean has been dominated by the powerful currents that flow uninterrupted for thousands of miles across it, before crashing into the East African coast.
All right, so this gives you a really good idea of the way that the currents are moving along this coastline.
Particularly this East African coastal current, or the Zanzibar one.
The combination of the currents and the winds have completely dictated the way that people have manoeuvred around, particularly this part of the Indian Ocean.
Lucy believes there's much to learn from mankind's battles with these treacherous currents.
So the expedition's heading for a site of particular interest to her, the wreck of a ship sunk 40 years ago in the unpredictable waters of the Indian Ocean.
To avoid the same fate, the expedition ship will have to be extremely cautious.
When I was talking with the skipper earlier, he was saying, you know, "This is actually quite a treacherous area.
" I mean, we're not actually mooring up because the currents are quite complex and unpredictable.
But when they reach the site, they find they aren't the only ones interested in it.
A group of local salvagers are already here trying to break up the ship and recover valuable metals.
They're none too pleased to have competition.
All right, folks, we've got a little bit of a situation out there.
It's a bunch of guys that are trying to cut off the propeller with welding gear.
I don't know whether they think that we're going to try and poach their propeller from them.
It's big and it's worth a lot of money, but they're protecting themselves with spear guns.
- Okay.
- And, Scott, he actually had one of them go to him As expedition leader, Paul's worried about the safety of his team.
But for Lucy, this is an example of a worldwide problem she often faces, the destruction of archaeological sites.
There's nothing we can do.
I mean, if they start ripping off the portholes and the props and all the rest of it, there's nothing for anybody to see.
There's nothing for anybody to learn about it.
I'm actually rooting for them.
- Why? - Because I feel Then we could end up having some contretemps.
I feel that the ship is in their waters, and that propeller and all, any of the bits they can use, will sustain their livelihood better than tourists coming and looking at it.
Really, I'm not sure about that, though, because you have That thing is there for an instance.
They are going to reap an immediate reward.
- Hmm.
- It's just condoning that whole activity, encouraging other people do to it on wrecks throughout the world, and then it's gone.
Whichever one of you is right, it's not the immediate problem.
- No.
- The immediate problem is that they've got spear guns and they exhibited very threatening behaviour.
The situation is tense.
A crew member who speaks Swahili has gone over to explain that the team are just here to dive the wreck.
Mike, this is Richard.
Come in.
Over.
The translator's just talked with the salvage crew, and they've given us permission to dive on the site.
Mike, that's fantastic.
The salvagers stop diving.
The team can get to work.
One This is what the salvagers are after, the remains of the Proportion.
Wow, it's absolutely huge! After 40 years on the bottom, there's still a lot left of this 94-metre cargo ship.
It's clear from the chains and pulleys that the salvagers are well on their way to removing the huge bronze propeller.
Bronze scrap is worth thousands of pounds per ton.
It's going to be a lot of work to shift this, and ultimately it's setting a precedent for just ripping shipwrecks apart, regardless of whether they're 40 years old or 400 years old.
All shipwrecks tell the story of a moment in time when a combination of circumstances came together to create a catastrophe.
So the Proportion sunk here in 1967, early in the evening, carrying wheat from Romania to Jedi.
The ship was meant to go via the Suez Canal, but with the Arab-Israeli war in full swing, that was closed, forcing the Proportion to travel right round Africa.
For weeks, the voyage went well.
Then, with just days to go, things went badly wrong.
We believe that they'd lost their radar and their echo-sounder and they were basically travelling in very unfamiliar waters.
So they had to resort to compass and sextants and navigating by the stars in currents which they didn't understand.
Just imagine the sense of terror coming up on this reef.
Completely lost, the noise, panic.
She hit this reef behind us and then broke her back, sprawling down here onto the sand.
Somehow, everyone on board survived, but the reef and the currents battered and sank the Proportion.
Considering she's only been down 40 years, it's an amazing amount of marine life, though, here.
The Proportion may be home to many fish, but Lucy is shocked at how the salvagers are wiping out precious historical information.
I mean, they've got rigs up there.
They've got, you know, the whole works.
- Is it pretty much free game? - It's free game.
It's free game at the moment, yeah.
It's free game.
This is not in the marine reserve area, so there's nothing in terms of the conservation of this particular Zone that says And anyway, I would imagine it's very difficult to police.
I mean, I know how difficult it is in the UK.
My job on a daily basis is trying to battle against the problems of treasure hunters and salvage work, and when you do meet it face to face, it You can't but, you know, despise it and everything it represents.
Ten days ago, the expedition launched the Argo float to monitor the depths of the Indian Ocean.
There it goes.
I'm waving goodbye to it on its four-year mission.
It's now scheduled to surface and upload its first data.
But has its mission succeeded? - So this is - Moment of truth.
Well, it is the moment of truth, because with any luck - First of all - Yeah.
If we can get this through, we're going to figure out if the Argo actually worked, so hang on.
- Is that the map? - That's it.
That's it? That's the transmit? Yeah, it is.
So it's working.
The map tracks the float's position from where Paul first powered it up to when it surfaced and successfully uploaded its data.
This must be us going out.
This is when we deployed it.
- Yeah, just about, gosh - And it sank.
And this is it here, so you see, it obviously didn't get stuck.
It's going on the expected track, which is north and then northwest.
And it's come up and it's sent the right expected data up.
- So, the blooming thing worked.
- So, you feel the flutter of pride that it actually worked.
The big thing for me, and it does excite me, is that it's real-time data.
So they're all coming up and down, all sending up temperature, salinity, depth and where they are.
For me, it's the fact that there are 3,000-plus of the Argo floats all over the world, so our little float is basically representative of just this huge global data search.
Scientists are already using the data to look into the future and determine how our oceans and climate might change over the next decade.
With just two days left, the team wants to see how one of the ocean's most elusive residents is faring in these fast-changing waters.
The hunt brings them here, to the Lazaretto Archipelago, a chain of islands 20 miles off the coast of Mozambique.
The islands are hammered by the powerful waves and winds that have shaped these 100-metre-high dunes built up over thousands of years.
You really get a sense of the power of the wind and the ocean here.
Just looking out over the Indian Ocean, next stop, Australia.
All that power of the Indian Ocean just slams into this coast, and it stings, it kind of stings the back of your legs.
- Stings? - Like you're getting sandblasted.
- Slamming into us at the moment.
- It is slamming.
The Lazaretto Archipelago acts as a barrier, absorbing the fury of the Indian Ocean and protecting the 20-mile stretch of water on the other side.
Toni believes it's here that the team may find a sensitive barometer of the health of the Indian Ocean, one of its rarest animals.
So this is the dugong.
With the best Latin name ever, the Dugong dugong.
A really bizarre kind of hybridisation between the dolphin tail Yeah.
And then you've got sort of a cow-like/elephantine front end.
They grow up to about 3.
4 metres, so they're a fairly decent size.
Dugongs once thrived in this part of the Indian Ocean, but not any more.
Hunting and entrapment in fishermen's nets have drastically reduced their numbers.
So how well is this tiny population doing? Right here is pretty much the last viable population of dugong in the Western Indian Ocean.
So we've come to this specific area to see if we can find them, and to be honest, it would be an absolute joy, and I think something really special if we did.
But finding them, I think, is going to be a bit of a nightmare.
Dugongs have always been mysterious.
Their unusual body shape probably inspired the myth of the mermaid.
They have what's called a bursiform body, combining the flute tail of a fish with four limbs and a snout-like head.
This isn't the first time Toni's searched for them.
She knows how tough it is looking for a few dugongs in a very big ocean.
I spent a month hunting for dugong and I didn't see a single flipping whisker.
So if we do see them, we are going to be exceptionally lucky.
Ready then, team? If they can find them, it will be a rare chance for Toni to see how well they're coping.
They head for an area they've been told has a high density of dugongs, but Toni is not convinced.
A high density is a little bit of a misnomer and it's a slightly misleading name, because "high density" suggests that there's loads of them swimming around.
But in actual fact, that's not true.
It just means that more of them have been spotted in that location than anywhere else.
Toni still hopes to find a few, but dugongs are notoriously timid.
The plan is to just cut the engines.
It's going to have to be a really, really quiet and slow operation, so we don't freak them out, 'cause as soon as they hear the boat noise or hear splashing, they're just going to be gone.
If we smell a dugong, it's going to be miraculous.
One of the crew believes they've seen a dugong, so Toni takes a chance and jumps in to try and get close.
But underwater, the visibility is terrible.
Finding the dugongs will take more than this.
Well, it just shows you how bad the visibility is, because we didn't see fiddly.
Paul is going to try and spot them from the air and guide Toni to them.
These things really are hard to find, so this is our secret weapon.
And Toni's really counting on me up there, she's really counting on me being able to see them from about 500 feet, and I can steer her in.
Delta Echo Oscar victor Charlie is entering and vectoring.
There's a bunch of goats ahead of us, so what we're going to try and do is get airborne before we hit any of the goats.
Toni, Toni, it's Paul in victor Charlie now.
Copy.
Paul, this is Toni.
Over.
We can see you.
If you just follow us now, follow this bearing.
Great, keep us posted.
Out.
Suddenly, Paul sees a grey smudge in the water.
There's a dugong! Dugong dugong, yeah.
Right there! It's coming round.
The wing's in the way, but you'll see him in a minute.
We've got a dugong.
In fact, it's a small group.
Toni, Toni, we are over Get your foot down, because we're over them right now.
That's great news, Paul, great news.
We'll make our way towards you now.
We head straight for the aeroplane, straight for the aeroplane.
I can sense dugong.
I can sense them.
Paul, Paul, which direction are they travelling in.
Over? The track you're on, they'll be right ahead, right ahead.
They're kind of Running parallel with you.
Yeah, at the surface.
They are at the surface.
Oh, I can see them! Toni, can you see them? They're right in front of you.
Over.
Roger that.
I can see them, Paul, I can see them.
I'm so happy that we've seen them, 'cause I didn't think I didn't think we were going to at all, actually, if truth be told.
Seeing the group of dugongs is positive evidence that the population here is surviving.
But then Paul spots something even more encouraging, a sign that the dugongs here may be in better shape than they'd thought.
And a cub.
You see the cub as well? Right there, right there.
Fantastic news, look at them.
Three and a half dugong! The dugongs are doing more than surviving.
They're reproducing.
It's incredibly good news.
That's that.
That's all right, isn't it? The team's success has come just in time.
We're off, we're getting so low on fuel.
Over.
Okay, Paul.
Thank you so much.
We did see the dugong, which is absolutely fantastic.
All right, guys.
Here we go.
It's the end of their Indian Ocean odyssey.
It was excellent.
They've journeyed through seas that support some of the most varied marine life on the planet.
Diving with the manta rays, one of the finest dives I've ever had.
You know, I've done over 6,000 of them.
The most special part of this expedition for me has been getting a chance to see this part of the world.
The diversity that's here, the diversity of life and abundance of life from an ocean perspective, because coral reefs here in the Indian Ocean are some of the most bio diverse in the world.
Coming on this project and seeing, you know, looking at the marine life as well as the cultural context has just reinforced to me how little we know about this ocean.
The Indian Ocean is so rich.
I'm worried about it, though.
So far, the Indian Ocean is holding its own.
But in a world that's being transformed so rapidly, how much longer can it cope? Next time, the team continues to explore the Indian Ocean.
They'll investigate how marine creatures can help predict extreme weather.
They'll dive the remains of a medieval village.
See this design here? That's got to be Oriental.
And try to protect the largest fish in the sea.