0:00:04 > 0:00:06In the vastness of the Pacific,
0:00:06 > 0:00:09a once-in-a-lifetime expedition is underway.
0:00:11 > 0:00:13We're on a voyage of discovery,
0:00:13 > 0:00:17covering over a thousand kilometres through the Galapagos Islands.
0:00:19 > 0:00:21Galapagos.
0:00:23 > 0:00:27One of the greatest treasures of the natural world.
0:00:27 > 0:00:30This place is just incredible.
0:00:33 > 0:00:38Over 1,000 species here are found nowhere else on Earth,
0:00:38 > 0:00:40and they've evolved in extraordinary ways.
0:00:43 > 0:00:46But this paradise is under threat,
0:00:46 > 0:00:49as our planet changes faster than ever before.
0:00:50 > 0:00:55He's such a beautiful specimen. What health checks are you carrying out?
0:00:55 > 0:00:59We've embarked on one of the most ambitious expeditions
0:00:59 > 0:01:01ever attempted in Galapagos.
0:01:01 > 0:01:04This just changes everything.
0:01:04 > 0:01:05Everything.
0:01:05 > 0:01:07'I'm Liz Bonnin.
0:01:08 > 0:01:10'I'm a wild animal biologist
0:01:10 > 0:01:12'and I'm helping to carry out
0:01:12 > 0:01:16'a series of ground-breaking research missions in the field.
0:01:17 > 0:01:21'With me is a team of world-renowned scientists.'
0:01:21 > 0:01:24- How's that look?- That looks perfect.
0:01:24 > 0:01:26'On this leg of our journey,
0:01:26 > 0:01:28'equipped with cutting-edge technology...
0:01:30 > 0:01:32'..we're going beneath the waves...
0:01:33 > 0:01:37'..to study the most endangered marine life in Galapagos...'
0:01:37 > 0:01:39I have a green board.
0:01:39 > 0:01:42'..in search of a giant of the deep...'
0:01:42 > 0:01:44- ALL GASP - It's massive!
0:01:44 > 0:01:48'..to reveal how young sea lions are fighting for their lives...'
0:01:48 > 0:01:51Mama's gone fishing. Look at this little munchkin!
0:01:53 > 0:01:58'..and to discover why hammerhead sharks gather here in huge numbers.'
0:01:58 > 0:02:00Oh, my God! Look at this!
0:02:01 > 0:02:03'But on such an expedition...'
0:02:03 > 0:02:06Toby, you're drifting onto us. Turn left, turn left...
0:02:06 > 0:02:09'..we're at the mercy of the mighty Pacific Ocean.'
0:02:09 > 0:02:11Oh, God! That was close.
0:02:11 > 0:02:14'This is Mission Galapagos.'
0:02:29 > 0:02:31We're one third of the way through
0:02:31 > 0:02:35our 1,000-kilometre voyage of discovery around the Galapagos,
0:02:35 > 0:02:39travelling on the scientific research vessel, the Alucia.
0:02:46 > 0:02:52Our expedition is continuing 1,000 kilometres west of South America,
0:02:52 > 0:02:53in the Pacific...
0:02:54 > 0:02:56..where the Galapagos Islands lie.
0:03:00 > 0:03:03So far, our journey has revealed
0:03:03 > 0:03:06how animals here are adapting on land.
0:03:07 > 0:03:10These animals are getting shorter to survive.
0:03:10 > 0:03:11It's like a magic trick.
0:03:13 > 0:03:17Now, we want to discover how animals are finding ways
0:03:17 > 0:03:19to survive in the ocean.
0:03:23 > 0:03:26Our first mission is taking us to the north-west tip
0:03:26 > 0:03:28of the largest island, Isabela.
0:03:32 > 0:03:33We're going in search
0:03:33 > 0:03:37of one of the world's most elusive marine creatures...
0:03:38 > 0:03:41..the mola, or ocean sunfish.
0:03:42 > 0:03:45They've been studied near the surface here,
0:03:45 > 0:03:47but never at depth.
0:03:47 > 0:03:50RADIO CHATTER
0:03:56 > 0:03:59Using Alucia's state-of-the-art submersible,
0:03:59 > 0:04:02we're hoping to observe one in the deep...
0:04:02 > 0:04:03This is Control, over.
0:04:03 > 0:04:05..and set down a receiver
0:04:05 > 0:04:08to track the movement of sunfish in the future.
0:04:08 > 0:04:11- Yeah, I'll make my way across. - Roger, Captain.
0:04:16 > 0:04:18There's a real buzz on board this morning.
0:04:18 > 0:04:21Everyone is excited about our plans for the day,
0:04:21 > 0:04:24particularly because this animal is just so rare,
0:04:24 > 0:04:26even here in the Galapagos.
0:04:29 > 0:04:33Marine biologist Dr Tierney Thys is leading our mission.
0:04:35 > 0:04:37She studies sunfish when they come to the surface.
0:04:37 > 0:04:41It's thought they do this to warm up in the sun, giving them their name.
0:04:44 > 0:04:48But no-one knows what sunfish do in deeper waters.
0:04:52 > 0:04:54You've got your standard hypothesis,
0:04:54 > 0:04:55that it's the food,
0:04:55 > 0:04:58and maybe, it's the finding mates.
0:04:58 > 0:05:00So, until you're down there with your own...
0:05:00 > 0:05:03you know, your own observational capabilities,
0:05:03 > 0:05:05you don't know the answer.
0:05:05 > 0:05:07They could be doing all sorts of different things.
0:05:12 > 0:05:16Taking us to the ocean floor is submersible pilot Buck Taylor.
0:05:18 > 0:05:21He's been a sub captain for almost 20 years.
0:05:21 > 0:05:23We couldn't be in safer hands.
0:05:23 > 0:05:27Galapagos is exciting on the way down.
0:05:27 > 0:05:31The last sort of 20, 30 metres, you've got everything running -
0:05:31 > 0:05:34sonars, lights - trying to see what the seabed's like.
0:05:36 > 0:05:40Touchdown and landing's definitely the bit that gets your heart going.
0:05:42 > 0:05:46For this mission, we'll be diving along the flanks of the volcano
0:05:46 > 0:05:48to a depth of 80 metres
0:05:48 > 0:05:52where Tierney thinks we might find sunfish.
0:05:56 > 0:05:58We'll then descend a further 20 metres,
0:05:58 > 0:06:02to the sea floor, to drop the receiver.
0:06:13 > 0:06:17The Nadir submersible will be our office for the next few hours.
0:06:19 > 0:06:21OK.
0:06:24 > 0:06:25It might be small,
0:06:25 > 0:06:28but it weighs a mighty eight tonnes.
0:06:28 > 0:06:32Just getting it into the water is a major operation.
0:06:39 > 0:06:42Nadir. That's swimmer clear. Am I clear to vent?
0:06:44 > 0:06:47- Roger. Venting now. - He vents a lot, that guy.
0:06:47 > 0:06:49BUBBLING
0:06:55 > 0:06:58Control, Control, Nadir. Depth - ten metres. Life support, OK.
0:06:58 > 0:07:00Vent secure. Descending. Over.
0:07:00 > 0:07:02'Copy, Nadir.'
0:07:09 > 0:07:12We begin to descend down the wall of the volcano.
0:07:18 > 0:07:21The water is clouded with nutrients and plankton.
0:07:22 > 0:07:24It's teeming with life.
0:07:27 > 0:07:29This is a real hot spot.
0:07:29 > 0:07:32- Sea lion. Right in front of us. Look!- Oh.
0:07:32 > 0:07:35- Look at how beautiful they are in the water.- He's so graceful.
0:07:59 > 0:08:04We reach a depth of 80 metres. This is the spot where Tierney thinks
0:08:04 > 0:08:06we're most likely to see sunfish.
0:08:07 > 0:08:09How much is known about the mola,
0:08:09 > 0:08:12particularly the mola that hang out in the Galapagos?
0:08:12 > 0:08:14Well, not a lot.
0:08:14 > 0:08:17Not a lot. So, we're covering a lot of new ground.
0:08:17 > 0:08:20Ah! Mola! Deep! Coming right in.
0:08:20 > 0:08:22- Oh.- Oh, my gosh!- OK, so...
0:08:22 > 0:08:25- Mola, guys. Right in front of us. - 82 metres. 82 metres.
0:08:25 > 0:08:28Oh, my gosh! It's massive!
0:08:33 > 0:08:37Just an hour into our dive and we've found a sunfish.
0:08:40 > 0:08:42Tierney has never observed one this deep before.
0:08:47 > 0:08:51- It's the most odd shape for a fish. - So elegant.
0:08:51 > 0:08:53It's really elegant despite the fact
0:08:53 > 0:08:57that it looks like a big dinner plate with two fins on either side.
0:08:57 > 0:08:59It just looks so unusual.
0:09:01 > 0:09:03I mean, how big can they get?
0:09:03 > 0:09:05Well, the sunfish can get to be over three metres long,
0:09:05 > 0:09:08- two and a half tonne. - Two and a half tonne?!
0:09:08 > 0:09:10That's the weight of a big car.
0:09:10 > 0:09:13- Two big cars.- A small truck. - Yeah, easily.
0:09:16 > 0:09:20The sunfish is the world's largest bony fish.
0:09:21 > 0:09:25As it grows, it gains an incredible one kilogram per day.
0:09:27 > 0:09:30Its main food is jellyfish,
0:09:30 > 0:09:33so Tierney thinks that sunfish might be venturing down here
0:09:33 > 0:09:38to feed on them. But today, they're after something else.
0:09:45 > 0:09:46Oh!
0:09:46 > 0:09:50- It's getting cleaned. It's getting cleaned!- It's getting cleaned!
0:09:51 > 0:09:56Sunfish skin carries as many as 40 different parasites.
0:09:56 > 0:10:00The tiny organisms are removed by cleaner fish.
0:10:00 > 0:10:04Hogfish are one of several species which do this here.
0:10:04 > 0:10:05Without this cleaning service,
0:10:05 > 0:10:09the sunfish would become infested with parasites,
0:10:09 > 0:10:10compromising its health.
0:10:10 > 0:10:12Is this the first time, then,
0:10:12 > 0:10:15that you can categorically say that Galapagos mola
0:10:15 > 0:10:18- are being cleaned at this depth, then?- Yes.
0:10:18 > 0:10:23- Yes, because this is below our diver depth.- Right, so that's a first.
0:10:23 > 0:10:25This is a first.
0:10:27 > 0:10:29It looks like it's sort of in another world right now.
0:10:29 > 0:10:34It doesn't seem like it's very aware of what's going on around it.
0:10:34 > 0:10:36By taking that unusual attitude,
0:10:36 > 0:10:39it's saying to everybody who could potentially clean it,
0:10:39 > 0:10:41"I'm ready for my spa treatment.
0:10:41 > 0:10:43"Come in and exfoliate me..."
0:10:43 > 0:10:46- "I'm not going to eat you." - "..and I'm not going to eat you.
0:10:46 > 0:10:49"I'm at peace, and come do your thing."
0:10:50 > 0:10:54For me, they underscore how everybody plays a role,
0:10:54 > 0:10:57Even the tiniest little fishes are of service to the big ones.
0:10:57 > 0:11:00The big ones are of service to the little ones,
0:11:00 > 0:11:02and you need everyone.
0:11:02 > 0:11:05Everyone is what makes this system tick.
0:11:37 > 0:11:39But our dive isn't over yet.
0:11:42 > 0:11:44After two hours underwater,
0:11:44 > 0:11:47we reach a depth of nearly 100 metres.
0:11:49 > 0:11:53We've got one last thing to do before returning to the surface.
0:11:56 > 0:11:57- It's a good spot.- OK, Rover.
0:11:57 > 0:11:59We're going to set up to deploy.
0:11:59 > 0:12:04Very little is known about this incredibly rare species.
0:12:05 > 0:12:08This receiver will help to further Tierney's research,
0:12:08 > 0:12:12enabling her to monitor the movement and behaviour of sunfish
0:12:12 > 0:12:15tagged at the surface with tracking devices.
0:12:16 > 0:12:19- Look at that.- Good luck.
0:12:19 > 0:12:21Control, control - Nadir!
0:12:21 > 0:12:26Mark this waypoint, transducer deployment site, over.
0:12:28 > 0:12:32This is the first-ever deep-water receiver in Galapagos.
0:12:33 > 0:12:36- It's a special moment, Tierney. - Yes, it is.
0:12:39 > 0:12:43It's powerful enough to run for 14 months.
0:12:43 > 0:12:47Being able to deploy listening stations below diver depth,
0:12:47 > 0:12:51it allows us to keep our finger on the pulse of a changing ocean.
0:12:55 > 0:12:58'You are clear to surface.
0:12:58 > 0:12:59'Clear to surface. Over.'
0:13:05 > 0:13:07That was a brilliant dive.
0:13:07 > 0:13:08Amazing.
0:13:11 > 0:13:13All right! That was a great dive!
0:13:13 > 0:13:15That was epic!
0:13:17 > 0:13:18That was amazing!
0:13:19 > 0:13:21Dream come true.
0:13:23 > 0:13:26I'm not going to get this grin off my face in a hurry.
0:13:29 > 0:13:30I get it. I totally get it now.
0:13:30 > 0:13:33- I know.- I'm beginning to understand your obsession with sunfish.
0:13:33 > 0:13:35It's easy to be enchanted by them.
0:13:37 > 0:13:39ALL LAUGH
0:13:39 > 0:13:41WHOOPING
0:13:49 > 0:13:50Our next task is to study
0:13:50 > 0:13:55some of the most playful characters in Galapagos - sea lions.
0:13:59 > 0:14:02This group live on the coastline of Fernandina Island.
0:14:06 > 0:14:09They're one of the most endangered populations
0:14:09 > 0:14:11of sea lions on the planet.
0:14:19 > 0:14:24This is due in part to a regular weather phenomenon called El Nino.
0:14:26 > 0:14:29Its effects can be devastating for this population.
0:14:33 > 0:14:38And scientists believe that El Nino events are becoming more severe
0:14:38 > 0:14:39because of climate change.
0:14:42 > 0:14:45Marine biologist Dr Pelayo Salinas De Leon
0:14:45 > 0:14:48studies how El Nino affects sea lions.
0:14:50 > 0:14:51On this map,
0:14:51 > 0:14:55we can look for specific features of El Nino.
0:14:58 > 0:15:02For Galapagos, El Nino is really bad news,
0:15:02 > 0:15:05because it brings warm water from the Western Pacific
0:15:05 > 0:15:07that stops the production of food,
0:15:07 > 0:15:09you know, the basic levels, like plankton.
0:15:11 > 0:15:13Two cold currents are critical
0:15:13 > 0:15:16to all marine life in Galapagos.
0:15:16 > 0:15:18They're its lifeblood.
0:15:20 > 0:15:23These currents come from thousands of kilometres away
0:15:23 > 0:15:25and force nutrients up to the surface...
0:15:28 > 0:15:31..kick-starting a rich, marine food web.
0:15:35 > 0:15:37But El Nino disrupts these currents,
0:15:37 > 0:15:40raising water temperatures by up to two degrees
0:15:40 > 0:15:43which can severely affect the entire food chain.
0:15:46 > 0:15:49I'm getting an opportunity to observe first-hand
0:15:49 > 0:15:51how sea lions here are faring.
0:15:53 > 0:15:56So, we're just off the coast of Fernandina.
0:15:56 > 0:15:57It's nice and calm.
0:15:57 > 0:16:00The water's at its clearest, so we need to get going.
0:16:07 > 0:16:09The dive team has been out since first light,
0:16:09 > 0:16:12scouting the waters where the sea lions swim.
0:16:16 > 0:16:18We've had a quick recce in the little bay.
0:16:18 > 0:16:20- That's where we're going to go, in there.- OK. Perfect.
0:16:20 > 0:16:23It's incredibly shallow, maybe one metre,
0:16:23 > 0:16:26and there's juvenile sea lions in the bay.
0:16:35 > 0:16:37Monitoring young sea lion numbers like this
0:16:37 > 0:16:42can provide evidence of how well the entire colony is doing.
0:16:56 > 0:16:58If females can't find enough food,
0:16:58 > 0:17:00fewer pups will be born.
0:17:03 > 0:17:06And because pups feed on their mothers' milk for up to three years,
0:17:06 > 0:17:09those that ARE born can easily starve.
0:17:19 > 0:17:23Scientists are seeing evidence of the effects of the last El Nino.
0:17:24 > 0:17:27Numbers of sea lion pups have plummeted.
0:17:40 > 0:17:43But in the water, there are clues
0:17:43 > 0:17:46as to which pups still might fare better in tougher times.
0:17:49 > 0:17:52The vast majority are females and there is a good reason for that.
0:17:55 > 0:18:00Both male and female sea lions can catch food from six months old,
0:18:00 > 0:18:02but because males are bigger,
0:18:02 > 0:18:04they need to suckle their mother's nutritious milk
0:18:04 > 0:18:06for longer than the females.
0:18:09 > 0:18:13Daughters, meanwhile, are more independent,
0:18:13 > 0:18:16learning to hunt for themselves at an earlier age.
0:18:19 > 0:18:23This can give them an advantage when El Nino hits and times are hard.
0:18:25 > 0:18:28It's been shown that, in harsher years,
0:18:28 > 0:18:30when there isn't a lot of food around,
0:18:30 > 0:18:32more females are likely to survive
0:18:32 > 0:18:34because they've got all that practice in,
0:18:34 > 0:18:37so there's this balance with nature.
0:18:37 > 0:18:39The males get more milk when they're younger,
0:18:39 > 0:18:41but when things get tough out here,
0:18:41 > 0:18:43the females do a little bit better.
0:18:53 > 0:18:55Galapagos sea lion numbers
0:18:55 > 0:18:59have dropped by more than 50% in the last 30 years -
0:18:59 > 0:19:02but it's not all bad news.
0:19:05 > 0:19:07Scientists are finding signs
0:19:07 > 0:19:09that these sea lions are adapting
0:19:09 > 0:19:11by foraging at different depths...
0:19:12 > 0:19:14..or moving to other parts of Galapagos
0:19:14 > 0:19:17where the food supply is more plentiful.
0:19:18 > 0:19:21Thanks to their intelligent and resourceful nature,
0:19:21 > 0:19:24it's hoped their numbers will bounce back.
0:19:30 > 0:19:34Adaptation is vital for survival in Galapagos.
0:19:39 > 0:19:40And this species of cormorant,
0:19:40 > 0:19:42one of the world's rarest birds,
0:19:42 > 0:19:46tells one of the most extraordinary adaptation stories of all.
0:19:51 > 0:19:54It, too, has responded to the challenges
0:19:54 > 0:19:57this unique island chain presents.
0:19:58 > 0:20:00Over millions of years,
0:20:00 > 0:20:03this bird has lost its ability to fly.
0:20:06 > 0:20:11Instead, the flightless cormorant is a superb swimmer.
0:20:11 > 0:20:15It's developed a larger body and strong leg muscles
0:20:15 > 0:20:17that make it a powerful diver.
0:20:30 > 0:20:32And it's evolved denser, down-like feathers
0:20:32 > 0:20:35that trap tiny air bubbles,
0:20:35 > 0:20:38preventing them from getting waterlogged during deep dives.
0:20:46 > 0:20:50Cormorants don't have any large land predators
0:20:50 > 0:20:52that require them to fly off at a moment's notice
0:20:52 > 0:20:55and also, all of their food is beneath the surface.
0:20:55 > 0:20:58And so, evolution
0:20:58 > 0:21:02has allowed the cormorant to spend all of its energy
0:21:02 > 0:21:04in becoming a better, sleeker diver,
0:21:04 > 0:21:06and for that, it doesn't need its wings.
0:21:12 > 0:21:15The flightless cormorant hunts a variety of prey,
0:21:15 > 0:21:19including octopus, eels and crustaceans.
0:21:20 > 0:21:23A diverse diet which helps it to survive harsh times
0:21:23 > 0:21:26when the food supply might be disrupted.
0:21:32 > 0:21:34Oh, no. Look!
0:21:35 > 0:21:36Mama's gone fishing.
0:21:36 > 0:21:38Look at this little munchkin!
0:21:40 > 0:21:41Hi, baby.
0:21:43 > 0:21:44Bye, sweet thing.
0:21:54 > 0:21:57Severe El Ninos can threaten the survival of the animals here...
0:22:07 > 0:22:10..but the cold currents are returning,
0:22:10 > 0:22:13bringing with them a bountiful food supply.
0:22:14 > 0:22:17This year is going to be amazing.
0:22:18 > 0:22:22With such cold water, there's going to be life everywhere.
0:22:23 > 0:22:27These cold currents will deliver the all-important nutrients
0:22:27 > 0:22:30that all life in Galapagos relies on.
0:22:31 > 0:22:34Orca pod just sighted...there!
0:22:34 > 0:22:36Right there! That's the male!
0:22:36 > 0:22:38A huge dorsal fin.
0:22:38 > 0:22:40There's about three or four of them.
0:22:44 > 0:22:50It just goes to show how rich these waters are.
0:22:50 > 0:22:51There's the male!
0:22:54 > 0:22:57The ocean here is heaving with food,
0:22:57 > 0:23:00all the way up the food chain. The orcas are here.
0:23:00 > 0:23:02There must be a lot of fish.
0:23:02 > 0:23:05I just saw a sea lion, there, in the background
0:23:05 > 0:23:09and it's all down to this current bringing all those nutrients,
0:23:09 > 0:23:13and then, the whole food chain just benefits from that bounty.
0:23:15 > 0:23:18INDISTINCT RADIO CHATTER
0:23:20 > 0:23:22For the next part of our expedition,
0:23:22 > 0:23:25we're focusing on the sharks of Galapagos.
0:23:28 > 0:23:29I've had such an incredible time
0:23:29 > 0:23:33getting to know the west of the Galapagos, but I am keen to see more
0:23:33 > 0:23:37and we are now heading to the two most northerly islands
0:23:37 > 0:23:41in the archipelago - the frontier islands of Wolf and Darwin.
0:23:45 > 0:23:50These two rugged islands are located 160 kilometres north of us.
0:23:55 > 0:23:57The journey takes the entire night.
0:24:05 > 0:24:07By daybreak...
0:24:09 > 0:24:11..we're anchored in the centre
0:24:11 > 0:24:14of the now extinct volcano, Wolf Island.
0:24:16 > 0:24:18The waters beneath us boast
0:24:18 > 0:24:23one of the highest concentrations of sharks in the world...
0:24:24 > 0:24:27..and 33 different species have been recorded here.
0:24:32 > 0:24:36Today, we're interested in a particular one...
0:24:37 > 0:24:40..the endangered scalloped hammerhead shark.
0:24:44 > 0:24:47They congregate here in vast numbers.
0:24:47 > 0:24:49Our task is to assess just how many.
0:24:59 > 0:25:03Shark expert Dr Alex Hearn is leading this mission.
0:25:04 > 0:25:09He's been studying hammerheads there for the past 11 years.
0:25:09 > 0:25:13The scalloped hammerhead shark is classified as endangered,
0:25:13 > 0:25:16and this is because it's been subject to overfishing,
0:25:16 > 0:25:18especially in this region.
0:25:18 > 0:25:20Over the last 20 years,
0:25:20 > 0:25:22there's been a huge increase
0:25:22 > 0:25:25in the demand for shark products,
0:25:25 > 0:25:28and in particular, shark fins for shark fin soup,
0:25:28 > 0:25:30and hammerhead sharks in particular,
0:25:30 > 0:25:33because of their large fins, are a desirable species to catch.
0:25:37 > 0:25:42In many parts of the world, hammerhead numbers have decreased
0:25:42 > 0:25:45by a staggering 99% in the past 30 years.
0:25:50 > 0:25:53Alex believes that the gathering here
0:25:53 > 0:25:56is now the biggest remaining one on the planet.
0:25:58 > 0:26:01If he's right, this will help the cause to protect them.
0:26:04 > 0:26:08But how do you count hammerheads when they're always on the move?
0:26:15 > 0:26:18The answer is by fitting them with tags
0:26:18 > 0:26:21that will be detected by an underwater receiver.
0:26:23 > 0:26:26The man responsible for this daunting task
0:26:26 > 0:26:27is Dr Cesar Penaherrera.
0:26:29 > 0:26:32His research group is the only one in the world
0:26:32 > 0:26:34with permits to tag hammerheads like this.
0:26:48 > 0:26:51So, this is one of the tags that we use. It's an acoustic tag
0:26:51 > 0:26:54that sends a sound signal in the water.
0:26:54 > 0:26:59In a normal dive, you can count probably, I don't know, 80 sharks.
0:26:59 > 0:27:03But there are not 80, there are more sharks moving around the area
0:27:03 > 0:27:05and that amount of the sharks that we tag,
0:27:05 > 0:27:08it helps us to refine and get more accurate estimates.
0:27:08 > 0:27:11The good that we are getting out of this information is vital,
0:27:11 > 0:27:13not only for protecting sharks here
0:27:13 > 0:27:16but to show what do we need to know about them.
0:27:21 > 0:27:25Hammerheads are disturbed by the noise and bubbles
0:27:25 > 0:27:26of scuba-diving gear.
0:27:26 > 0:27:31So Cesar has to free-dive and tag them by hand.
0:27:32 > 0:27:36He can hold his breath for an incredible two and a half minutes
0:27:36 > 0:27:39and dive to depths of 15 metres.
0:27:39 > 0:27:43Is there any other way to tag a shark other than free-diving?
0:27:43 > 0:27:46Well, there are, but particularly with hammerhead sharks,
0:27:46 > 0:27:50this is the fastest way to get most of the data that we need.
0:27:55 > 0:27:58Hammerheads have eyes on either end of their wide heads.
0:28:02 > 0:28:05This gives them superb depth perception,
0:28:05 > 0:28:09allowing them to accurately track and catch fast-moving prey.
0:28:12 > 0:28:15But it also means that they have a large blind spot
0:28:15 > 0:28:19in front of their heads, which Cesar is only too happy to exploit.
0:28:21 > 0:28:23I'm getting butterflies for you.
0:28:23 > 0:28:24HE LAUGHS And I commend you.
0:28:24 > 0:28:27Well, you should join me one of these days.
0:28:27 > 0:28:29There is no way in heck I would ever do it!
0:28:45 > 0:28:48You can see the hammerheads, the water is so clear.
0:28:48 > 0:28:50That's mad.
0:29:06 > 0:29:10Cesar aims for the thick skin at the base of the fin.
0:29:12 > 0:29:15If he's not certain he'll hit the target,
0:29:15 > 0:29:16he won't take the shot.
0:29:35 > 0:29:36Did you get it?
0:29:36 > 0:29:41- That was exciting! But, yeah, we got it.- That's amazing!
0:29:41 > 0:29:44Wow! I could see you for quite a distance, the water is so clear.
0:29:44 > 0:29:46That's amazing.
0:29:49 > 0:29:52He sets off to tag another shark.
0:29:56 > 0:29:58As risky as this might seem,
0:29:58 > 0:30:01the hammerheads are highly unlikely to attack Cesar.
0:30:01 > 0:30:05Aggressive behaviours towards humans are incredibly rare.
0:30:14 > 0:30:16Can you manage?
0:30:16 > 0:30:18- Wow!- Let me catch my breath.
0:30:18 > 0:30:20That was quite something.
0:30:20 > 0:30:22It's amazing to watch, Cesar.
0:30:22 > 0:30:24It really is.
0:30:24 > 0:30:26- Yeah. It is. It is... - HE PANTS
0:30:26 > 0:30:29Sorry, I have to catch my breath!
0:30:29 > 0:30:31I don't know how you do that.
0:30:37 > 0:30:39With ten hammerheads tagged,
0:30:39 > 0:30:43these new individuals can be added to Alex's data-set,
0:30:43 > 0:30:45and by analysing it,
0:30:45 > 0:30:49he can begin to get an idea of the size of these congregations.
0:30:52 > 0:30:54Preliminary estimates would suggest
0:30:54 > 0:30:58maybe there's 500 or 600 hammerhead sharks here at any given time.
0:30:58 > 0:31:00We are very happy.
0:31:02 > 0:31:04Alex's calculations show
0:31:04 > 0:31:07that this may be the biggest known congregation
0:31:07 > 0:31:09of hammerheads on the planet.
0:31:11 > 0:31:15This research helps to highlight just what an essential refuge
0:31:15 > 0:31:19these waters are, and how important it is to protect them.
0:31:20 > 0:31:25Darwin and Wolf are really among the last outposts in the world
0:31:25 > 0:31:27where we have these huge numbers of sharks.
0:31:27 > 0:31:29It's the front line of conservation.
0:31:31 > 0:31:36Alex has studied sharks here for many years, but never on this scale.
0:31:37 > 0:31:40Some of his previous data from GPS tags
0:31:40 > 0:31:43is revealing another remarkable discovery...
0:31:43 > 0:31:45Look how we've tagged them here and they've moved off...
0:31:45 > 0:31:48..the distance hammerheads are travelling.
0:31:48 > 0:31:51So, these are some tracks of the hammerheads
0:31:51 > 0:31:53that we've tagged with satellite tags.
0:31:53 > 0:31:57And so we can pinpoint their location at different times,
0:31:57 > 0:32:01and we can see, first off, that they've moved incredible distances.
0:32:01 > 0:32:03And so, we have these two sharks that headed out
0:32:03 > 0:32:05about 200, 300 kilometres north-east,
0:32:05 > 0:32:10and then we have this other one that headed over 500 kilometres out
0:32:10 > 0:32:11and back again to Darwin and Wolf.
0:32:11 > 0:32:15So, it's almost like Darwin and Wolf are the central hub.
0:32:19 > 0:32:20Alex's research reveals
0:32:20 > 0:32:23that hammerheads consistently return here.
0:32:27 > 0:32:30But why do they gather in such large numbers?
0:32:33 > 0:32:35Answering this is the second part of our mission.
0:32:46 > 0:32:50Alucia is a hive of activity
0:32:50 > 0:32:53as we prepare to dive with hammerheads.
0:32:58 > 0:33:03Alex has chosen a prime location nicknamed "Shark Point".
0:33:04 > 0:33:07It's full of large swells and strong currents.
0:33:11 > 0:33:15The perfect place for us to observe hammerhead behaviour.
0:33:20 > 0:33:22Yeah, roger that. Thanks very much.
0:33:22 > 0:33:26The target location is nearly 50 metres down.
0:33:26 > 0:33:28It's reachable with scuba gear,
0:33:28 > 0:33:31but we want to study the hammerheads for as long as possible
0:33:31 > 0:33:34without running out of air.
0:33:34 > 0:33:37So, for this mission, we need Nadir.
0:33:37 > 0:33:39We know where they are,
0:33:39 > 0:33:41but we don't know exactly what they are doing.
0:33:41 > 0:33:44The only way we can do that is by observation.
0:33:44 > 0:33:47We're really limited by scuba,
0:33:47 > 0:33:50which is why being able to jump into one of these
0:33:50 > 0:33:54and get down there and really spend some quality time with the sharks
0:33:54 > 0:33:57is going to give us so much more insight.
0:33:58 > 0:34:02This gathering in large groups is a behaviour called "schooling".
0:34:03 > 0:34:06But Alex doesn't know why hammerheads do it.
0:34:08 > 0:34:10So, how common is this behaviour and what is it exactly?
0:34:10 > 0:34:12Not all sharks school.
0:34:12 > 0:34:16Hammerheads are perhaps the most iconic of the ones that do.
0:34:16 > 0:34:20It basically means when you have a large group of sharks
0:34:20 > 0:34:23that stick close together for an extended period.
0:34:23 > 0:34:26Here, if we're lucky, we'll see schools of several hundred,
0:34:26 > 0:34:29which is just... And it will blow your mind!
0:34:29 > 0:34:31It really will!
0:34:33 > 0:34:36At the spot where the hammerheads prefer to gather,
0:34:36 > 0:34:39a huge current splits into two.
0:34:40 > 0:34:42So, we'll have to battle turbulent waters
0:34:42 > 0:34:45to get our sub into the right position.
0:34:48 > 0:34:50We're going to need the second submersible,
0:34:50 > 0:34:52Deep Rover, as a safety backup.
0:35:02 > 0:35:04It's actually called Shark Point,
0:35:04 > 0:35:07- because it's so sharky?- Because it's so sharky, yeah.- OK. OK.
0:35:07 > 0:35:10And then the hammerheads like to sit in that spot
0:35:10 > 0:35:11where the currents split,
0:35:11 > 0:35:14so it's like this little sweet spot that they sit in.
0:35:14 > 0:35:15That's where they want to be.
0:35:19 > 0:35:21'Deep Rover has just dropped.'
0:35:21 > 0:35:24As soon as we touch the water, we've got company.
0:35:24 > 0:35:27Inquisitive silky sharks have come to investigate.
0:35:29 > 0:35:32Two silkies. They love it. Oh, look at that.
0:35:32 > 0:35:35Are they sort of renowned for being the most curious sharks?
0:35:35 > 0:35:39- They are very curious.- Look at that! They are loving it.
0:35:39 > 0:35:40They seem to be fascinated by us.
0:35:40 > 0:35:43They're more fascinated by us than we are of them.
0:35:43 > 0:35:45INDISTINCT CONVERSATION
0:35:45 > 0:35:47Venting now.
0:35:48 > 0:35:50Oh, here we go.
0:35:56 > 0:35:57Control, Control. Nadir.
0:35:57 > 0:36:00Life support OK. Vents secure. Descending.
0:36:02 > 0:36:04Because of the difficult conditions,
0:36:04 > 0:36:06it's paramount that we work as a team
0:36:06 > 0:36:09with Mission Control on board Alucia.
0:36:09 > 0:36:13Once the subs get past about probably 80 metres,
0:36:13 > 0:36:15visibility starts to go.
0:36:15 > 0:36:18So, they're just going down, descending down,
0:36:18 > 0:36:21so they need us to tell them in which direction to go to.
0:36:35 > 0:36:37Together, we begin the dive
0:36:37 > 0:36:40and reach the sea floor relatively quickly.
0:36:45 > 0:36:47So far, no hammerheads.
0:36:49 > 0:36:53But in Galapagos, you never know what surprises might lie in store.
0:36:54 > 0:36:56I thought that was rubble,
0:36:56 > 0:36:59but it's all...it's all crabs.
0:36:59 > 0:37:01Wow!
0:37:05 > 0:37:10These spider crabs are most probably gathering in large numbers to mate.
0:37:11 > 0:37:13Grouping together like this
0:37:13 > 0:37:16also helps to protect them from predators such as octopus.
0:37:18 > 0:37:22From claw to claw, the largest males are over half a metre in length.
0:37:35 > 0:37:38I think we should move further along.
0:37:38 > 0:37:40I think we should move further to the Point, over?
0:37:49 > 0:37:52We're edging closer to Shark Point.
0:37:53 > 0:37:57But as we do, we're becoming more exposed to the currents.
0:38:01 > 0:38:04They're starting to push all eight tonnes of our sub.
0:38:09 > 0:38:11Yeah, affirmative. I don't think we'll go much further.
0:38:11 > 0:38:14- The current's starting to pull quite hard.- OK.
0:38:14 > 0:38:16So, we'll just hold it on this point.
0:38:18 > 0:38:19Come on, now, hammerheads.
0:38:19 > 0:38:22Starting to get in the zone now.
0:38:22 > 0:38:23Eyes peeled.
0:38:27 > 0:38:30You can see the currents coming in from either side,
0:38:30 > 0:38:32so we're right on the point now.
0:38:34 > 0:38:38Holding our position in these strong currents is proving difficult.
0:38:41 > 0:38:43Watch yourself, Toby. You're drifting onto us.
0:38:43 > 0:38:45Turn left. Turn left.
0:38:47 > 0:38:49We're being pushed dangerously close together.
0:38:51 > 0:38:53A collision could spell disaster.
0:38:56 > 0:38:57Stay away, Toby.
0:38:57 > 0:38:59Keep coming to port.
0:39:01 > 0:39:02OK, that's good there.
0:39:02 > 0:39:05Fall down.
0:39:06 > 0:39:10The current keeps getting stronger and stronger,
0:39:10 > 0:39:12now pushing our sub towards the rocks.
0:39:12 > 0:39:15ENGINES WHIR
0:39:15 > 0:39:18Come on, baby! Hold it!
0:39:22 > 0:39:25We're going backwards!
0:39:30 > 0:39:34- ENGINES WHIR - Come on, come on, come on...!
0:39:42 > 0:39:45- Is that the current pushing you? - Yeah.- Oh, my God!
0:39:46 > 0:39:51Nadir is no match for the surging water, even on full power.
0:39:51 > 0:39:56- Jesus Christ! - Look behind you. It's just mad.
0:39:56 > 0:40:00Are you used to this? Does it happen a lot?
0:40:00 > 0:40:01Er, no...
0:40:07 > 0:40:11On board Alucia, the team is unaware of the problem.
0:40:11 > 0:40:13We've lost communication.
0:40:14 > 0:40:18Control, Nadir. Do you copy my last, over?
0:40:19 > 0:40:22Turbulent water can disrupt comms,
0:40:22 > 0:40:24as well as the tracking of our sub.
0:40:26 > 0:40:29Comms, at the moment, are poor.
0:40:29 > 0:40:32We'll move to clearer water
0:40:32 > 0:40:35and, hopefully, get a better comms angle to them.
0:40:38 > 0:40:40We finally spot some hammerheads,
0:40:40 > 0:40:42but they're the last thing on our minds
0:40:42 > 0:40:45as we're forced towards jagged rock.
0:40:52 > 0:40:54Oh, God! That was close!
0:41:03 > 0:41:06At last, Buck gets Nadir back under control.
0:41:07 > 0:41:09Control, Nadir.
0:41:09 > 0:41:11Over. Strong current.
0:41:11 > 0:41:15Seeking permission to ascend back to the surface. Over.
0:41:15 > 0:41:16Bottom depth, 116 metres. Over.
0:41:16 > 0:41:19I'm kind of relieved to be going to the surface, I have to say.
0:41:19 > 0:41:21Just this once.
0:41:22 > 0:41:27Buck releases bubbles to help Alucia find us at the surface.
0:41:36 > 0:41:39DEEP SPLOOSHING
0:41:59 > 0:42:02On the scale of one to ten with things you've had to deal with,
0:42:02 > 0:42:06- with respect to currents, what was that?- That was up there.
0:42:06 > 0:42:08I would say nine and three quarters.
0:42:08 > 0:42:12It was taking us from 15 metres down to about 45.
0:42:12 > 0:42:13Just pumping us up and down.
0:42:13 > 0:42:18And I tell you what, as much as I've had an amazing time in the subs
0:42:18 > 0:42:21and then really beginning to appreciate the oceans,
0:42:21 > 0:42:25this experience has made me realise we've got to still respect it.
0:42:25 > 0:42:29She's the boss, and every now and then, she lets you know it.
0:42:29 > 0:42:31- Thank you for getting us out of the soup.- Thank you.
0:42:31 > 0:42:34And thanks for being part of the adventure.
0:42:34 > 0:42:36- I loved it. - When do we go back down?
0:42:36 > 0:42:38- Half an hour? - I'm going for a gin and tonic!
0:42:38 > 0:42:40ALL LAUGH
0:42:45 > 0:42:48Our failed sub dive is a setback.
0:42:50 > 0:42:53We managed to catch a brief glimpse of hammerheads gathering,
0:42:53 > 0:42:56but not long enough to be able to study them properly.
0:42:57 > 0:43:01And now, with time running out before we need to move on,
0:43:01 > 0:43:04we only have one more chance to observe their behaviour.
0:43:06 > 0:43:09The team regroup to discuss the plan...
0:43:11 > 0:43:14..and it's decided that the currents at Wolf Island
0:43:14 > 0:43:17are just too strong to risk another sub dive.
0:43:19 > 0:43:22We choose to relocate 20 kilometres north
0:43:22 > 0:43:24to nearby Darwin Island.
0:43:31 > 0:43:34Not much can live on this barren rock...
0:43:36 > 0:43:37..but beneath the waves,
0:43:37 > 0:43:40it's brimming with life and, hopefully, hammerheads.
0:43:47 > 0:43:51Alex is keen to get into the water as soon as possible.
0:43:52 > 0:43:55Now, we've got to get the sub in,
0:43:55 > 0:43:58because hammerheads tend to move offshore at night to feed,
0:43:58 > 0:44:00and come back at dawn. What I'm hoping is,
0:44:00 > 0:44:03over the morning, as the hammerheads come back,
0:44:03 > 0:44:05they'll build into a nice school
0:44:05 > 0:44:08and then we can go down and start looking at their interactions.
0:44:08 > 0:44:11So, let's really hope we can get the sub down there.
0:44:15 > 0:44:17The bulk of the hammerheads are due back
0:44:17 > 0:44:21from feeding out in deeper water at any moment.
0:44:24 > 0:44:28This is the ideal time and place to see them school.
0:44:37 > 0:44:41But Buck and dive master Steve have been assessing the site
0:44:41 > 0:44:43and there's a problem.
0:44:44 > 0:44:47Conditions, visibility-wise, are lovely.
0:44:47 > 0:44:49Very blue. Lots of fish.
0:44:49 > 0:44:52Lots of hammerheads. However...
0:44:52 > 0:44:54- Currents, don't tell us. - The current is strong.
0:44:54 > 0:44:58- It's a definite no.- At the moment.
0:44:59 > 0:45:03It's just too dangerous to use the sub.
0:45:03 > 0:45:07With time running out, we decide to attempt a dive with scuba instead.
0:45:09 > 0:45:11Remind me again why it's not OK for the sub,
0:45:11 > 0:45:15but it's OK for us, even though the currents are so strong?
0:45:15 > 0:45:18A sub is very big and lumbering, and we find it hard to hide.
0:45:18 > 0:45:22Whereas, you're small, agile, nimble. You can tuck into the rocks.
0:45:22 > 0:45:24I don't know about the agile bit...
0:45:24 > 0:45:27It would be crazy to waste this time.
0:45:27 > 0:45:29It would. We need to observe more hammerheads.
0:45:29 > 0:45:31We need to see what it's all about down there.
0:45:31 > 0:45:34- And the action's happening now. - So, they're there now?
0:45:34 > 0:45:37- Are they schooling? - They are schooling.- Oh, right.
0:45:37 > 0:45:40- Let's go.- Wet-suit time? - Yes.- OK, perfect.- Let's do it.
0:45:45 > 0:45:48Scuba isn't an ideal way to observe hammerheads,
0:45:48 > 0:45:50as the noise and bubbles spook them.
0:45:54 > 0:45:57But, at least for a short time, at a safe depth,
0:45:57 > 0:45:59we might get to watch them as they school.
0:46:06 > 0:46:10To maximise his chances of studying this behaviour,
0:46:10 > 0:46:15Alex has asked the dive team to construct an array of cameras.
0:46:15 > 0:46:17They will be left unmanned,
0:46:17 > 0:46:19recording on the sea floor,
0:46:19 > 0:46:21and retrieved later.
0:46:22 > 0:46:25I'm covering 360 degrees, basically.
0:46:25 > 0:46:27So, towards you. Behind me.
0:46:27 > 0:46:28Left and right.
0:46:30 > 0:46:31Alex hopes this will help him
0:46:31 > 0:46:34to better understand the sharks' behaviour.
0:46:40 > 0:46:42INDISTINCT
0:46:42 > 0:46:47This location is an iconic dive site at the tip of the island.
0:46:50 > 0:46:51Darwin's Arch.
0:46:54 > 0:46:57With dangerous rocks and strong currents,
0:46:57 > 0:47:02it's a testing dive location for even the most experienced of divers.
0:47:04 > 0:47:07You get big seas. There's strong currents.
0:47:07 > 0:47:10You get counter currents. You get up-wellings,
0:47:10 > 0:47:14and what we don't want to do is get into a situation
0:47:14 > 0:47:16whereby we start drifting,
0:47:16 > 0:47:21because there's a place further on known as the "Meat Grinder".
0:47:26 > 0:47:29It will be the most advanced dive I've ever attempted.
0:47:29 > 0:47:31But I'm in safe hands.
0:47:33 > 0:47:35Bobby, my dive buddy, has a plan.
0:47:37 > 0:47:39Liz, so what we're going to do
0:47:39 > 0:47:42is I'm going to actually get behind you and push you down by your tank,
0:47:42 > 0:47:46just to assist you to get down on the rocks as quick as possible.
0:47:46 > 0:47:47So, then we'll proceed with the dive,
0:47:47 > 0:47:50so we'll just bounce along the rocks. Get a little closer.
0:47:50 > 0:47:52Right at the edge and then, hopefully,
0:47:52 > 0:47:55we'll get the school of hammerheads right over the top of us.
0:47:55 > 0:47:57Okey dokey. So, I'm not going to see you beside me,
0:47:57 > 0:48:00but I'm going to feel you shoving me down into the water?
0:48:00 > 0:48:01I'll be right there with you the whole time.
0:48:01 > 0:48:03I'll just be right behind you.
0:48:19 > 0:48:22Conditions above the surface are intense.
0:48:25 > 0:48:28Beneath, it looks almost serene.
0:48:30 > 0:48:33But powerful swells and currents are in force.
0:48:38 > 0:48:40To avoid them,
0:48:40 > 0:48:44we descend quickly, looking for shelter among the rocks.
0:49:13 > 0:49:16The filming team has the added difficulty
0:49:16 > 0:49:18of taking the camera rig with them.
0:49:22 > 0:49:24Underwater cameraman Mike Pitts
0:49:24 > 0:49:29is able to communicate with the rest of the team with a special mask.
0:49:31 > 0:49:34There's such a strong
0:49:34 > 0:49:36surging current here.
0:49:36 > 0:49:38But we're going to get down.
0:49:45 > 0:49:49As predicted, the hammerheads are startled by the noise
0:49:49 > 0:49:51and bubbles of our scuba gear.
0:49:51 > 0:49:54The unmanned cameras will be vital
0:49:54 > 0:49:58for observing their natural, undisturbed behaviour.
0:49:58 > 0:50:02Jorge, can you hear me? Yo!
0:50:02 > 0:50:03Let's go!
0:50:06 > 0:50:10Only the team deploying the camera rig venture beyond the reef.
0:50:17 > 0:50:19This could be quite good here, I think.
0:50:22 > 0:50:25The camera is positioned, weighted down
0:50:25 > 0:50:29and switched on to record for four hours.
0:50:31 > 0:50:34Well, I hope nothing happens to it...
0:50:35 > 0:50:37..and the sharks don't bite it.
0:50:40 > 0:50:44Alex and I find a position to anchor ourselves at the reef's edge,
0:50:44 > 0:50:46just out of the currents.
0:50:46 > 0:50:50Beyond us, the ledge drops off hundreds of metres.
0:50:54 > 0:50:58The hammerheads should come right past this point, so, in theory,
0:50:58 > 0:51:01we're in the perfect spot to see them gathering.
0:51:04 > 0:51:06All we can do now
0:51:06 > 0:51:08is watch and wait.
0:51:16 > 0:51:18And then it begins.
0:51:28 > 0:51:30The hammerheads are gathering
0:51:30 > 0:51:33and our cameras are rolling.
0:51:42 > 0:51:44It's just like being in an aquarium.
0:51:45 > 0:51:50The only difference with this aquarium is it's for real.
0:51:56 > 0:51:58Oh, my God! Look at this!
0:52:44 > 0:52:47OK, we're just going to go up now gently.
0:52:47 > 0:52:51Finally, just before we hit the surface,
0:52:51 > 0:52:54Galapagos has one more surprise for us.
0:52:54 > 0:52:56I can't believe it!
0:52:56 > 0:52:59Whale shark! Whale shark!
0:53:02 > 0:53:04A passing whale shark,
0:53:04 > 0:53:07the biggest fish in the ocean.
0:53:07 > 0:53:08Whoo!
0:53:08 > 0:53:12Whoohoo! That is unbelievable!
0:53:22 > 0:53:27Something on the surface, port side, 15 metres.
0:53:31 > 0:53:32Good dive. Good dive.
0:53:36 > 0:53:38Oh, my God! That was amaz...!
0:53:40 > 0:53:42Hammerheads, fireworks and fish.
0:53:42 > 0:53:45Shark everywhere.
0:53:47 > 0:53:48That was totally worth it.
0:53:48 > 0:53:51It's like a dream. Like the best dream you would ever have,
0:53:51 > 0:53:53except it's real.
0:53:54 > 0:53:56That was a good morning at the office!
0:53:56 > 0:53:58HE LAUGHS
0:54:04 > 0:54:07By observing these hammerheads school,
0:54:07 > 0:54:09Alex is closer than ever before
0:54:09 > 0:54:11to explaining why they group like this.
0:54:16 > 0:54:19The hammerheads. They were coming in. They were circling.
0:54:19 > 0:54:22What it appears to be is that the largest females
0:54:22 > 0:54:25tend to dominate the centre of the school,
0:54:25 > 0:54:27and the smallest ones are around the outside.
0:54:27 > 0:54:29And then the males are kind of trying to mate
0:54:29 > 0:54:32with the females that are at the centre.
0:54:32 > 0:54:33It was a stunning dive.
0:54:33 > 0:54:34It really was.
0:54:37 > 0:54:39Alex believes this behaviour
0:54:39 > 0:54:42is part of a complex courtship ritual.
0:54:46 > 0:54:49The largest, more sexually mature females
0:54:49 > 0:54:53place themselves at the centre of the school.
0:54:53 > 0:54:55This means that only the strongest males,
0:54:55 > 0:54:59capable of making their way through, succeed in mating with them.
0:55:02 > 0:55:05Footage from our locked-off cameras supports this theory...
0:55:09 > 0:55:11..shedding light on our understanding
0:55:11 > 0:55:13of hammerhead behaviour.
0:55:24 > 0:55:28That's just opened my eyes to... this extraordinary world
0:55:28 > 0:55:31that we hardly understand, beneath the waves. It's just...
0:55:31 > 0:55:34It's just shifted something in my brain.
0:55:38 > 0:55:41It's more glorious than you can possibly imagine.
0:55:52 > 0:55:55On this leg of our journey,
0:55:55 > 0:55:58Alucia and her technology have helped us to understand
0:55:58 > 0:56:01the rapidly changing oceans here like never before.
0:56:08 > 0:56:12We've found a rare ocean giant in the deep...
0:56:14 > 0:56:18..learned more about the survival strategies of sea lions...
0:56:21 > 0:56:24..and we've come closer to revealing why hammerheads gather here.
0:56:30 > 0:56:33Our responsibility to protect these waters
0:56:33 > 0:56:36has never been more important.
0:56:39 > 0:56:43'Next time on Mission Galapagos...
0:56:43 > 0:56:48'we'll explore what the future holds for this last, great wilderness.'
0:56:48 > 0:56:53We're heading to a lush, green world, unlike any other.
0:56:54 > 0:56:58'What does the magma chamber, deep beneath Galapagos...'
0:56:58 > 0:57:01This place is just incredible.
0:57:01 > 0:57:04'..reveal about the future of these volcanic islands?'
0:57:04 > 0:57:07It feels pretty special to sit here imagining
0:57:07 > 0:57:09that lava used to rush through here.
0:57:10 > 0:57:14'How are scientists protecting the ancient migration routes
0:57:14 > 0:57:17'of the Islands' most iconic creatures?'
0:57:17 > 0:57:21Tortoises will definitely suffer the consequences.
0:57:21 > 0:57:25'And how can deploying the latest drone technology
0:57:25 > 0:57:29'help us to save an enchanted forest?'
0:57:29 > 0:57:31This place is so completely different
0:57:31 > 0:57:33to anywhere else I've been on these islands.