0:00:08 > 0:00:11Sharks are the ocean's top predators.
0:00:15 > 0:00:18They have a reputation as being nothing more than ruthless,
0:00:18 > 0:00:19mindless hunters.
0:00:23 > 0:00:28- But that is about to change. - You guys ready to go? Awesome.
0:00:34 > 0:00:37Scientists are getting closer to sharks than ever before.
0:00:41 > 0:00:45They're discovering that sharks are intelligent and sociable.
0:00:45 > 0:00:50These are really, really charismatic animals if you give them a chance.
0:00:50 > 0:00:53They're using extraordinary experiments to show their hidden
0:00:53 > 0:00:56abilities to find food.
0:00:56 > 0:00:58They just appear like ghosts behind the boat.
0:01:02 > 0:01:05Inventing cameras to find sharks that glow in the dark...
0:01:06 > 0:01:08It is pretty sci-fi.
0:01:08 > 0:01:11..even unlocking the secrets of their skin,
0:01:11 > 0:01:15to help us go faster and help cure deadly diseases.
0:01:19 > 0:01:21I really think we're at a turning point.
0:01:27 > 0:01:34This is a new dawn of discovery for sharks.
0:01:52 > 0:01:55Sharks have some of the most powerful sensors in nature.
0:01:59 > 0:02:02By studying how they work, scientists are making
0:02:02 > 0:02:05important discoveries about how sharks survive.
0:02:11 > 0:02:14They've learnt that sharks are so sensitive to electric fields,
0:02:14 > 0:02:17they can detect the beating heart of their prey...
0:02:20 > 0:02:23..that by picking up on pressure changes,
0:02:23 > 0:02:26they can feel movement, rather than see it...
0:02:30 > 0:02:34..and that sharks have highly sensitive ears
0:02:34 > 0:02:36so they can hear dinner long before they smell it.
0:02:45 > 0:02:48The ocean is a surprisingly noisy place.
0:03:01 > 0:03:04Sharks can hear sounds from several miles away.
0:03:08 > 0:03:10From a few fish...
0:03:11 > 0:03:13..to a huge feeding frenzy.
0:03:21 > 0:03:22Amidst the din,
0:03:22 > 0:03:26they must focus only on the sounds that will lead to food.
0:03:38 > 0:03:39Here in the Bahamas,
0:03:39 > 0:03:44scientists are studying a shark that is the master at using its hearing.
0:03:51 > 0:03:54Oceanic Whitetips live out in the open ocean.
0:03:56 > 0:03:59It's one of the toughest places to be a shark.
0:04:04 > 0:04:08In this big blue desert, food is patchy and hard to find.
0:04:13 > 0:04:17Dr Demian Chapman thinks these sharks use their hearing
0:04:17 > 0:04:19and their wits to survive.
0:04:19 > 0:04:22The oceanic white tip, the key thing is finding food.
0:04:22 > 0:04:24You're a constant clock.
0:04:24 > 0:04:27You need food, your metabolic needs, need to be met
0:04:27 > 0:04:30and there's not much food out there, so anything that gives them
0:04:30 > 0:04:34the edge in finding a big meal is really important to them.
0:04:36 > 0:04:40With Oceanic Whitetips, that edge is their hearing.
0:04:42 > 0:04:45And the first people to witness their extraordinary skills
0:04:45 > 0:04:47were not scientists, but sports fishermen.
0:05:00 > 0:05:02The moment they got a bite,
0:05:02 > 0:05:05Oceanic Whitetips would appear at their boat.
0:05:10 > 0:05:13The Whitetips can hear the engines from miles away,
0:05:13 > 0:05:17but somehow know only to arrive just when a fish has been caught.
0:05:19 > 0:05:23Demian thinks it's all down to the way they use their hearing.
0:05:23 > 0:05:26The sport fishing boat is just cruising like this.
0:05:26 > 0:05:28You hear the motor going.
0:05:29 > 0:05:32The sharks can hear that from a couple of miles.
0:05:34 > 0:05:39They key in on this sound, because whenever a guy catches a fish,
0:05:39 > 0:05:41that's the first the captain does, is drop out of gear
0:05:41 > 0:05:45so that they can start fighting the fish.
0:05:45 > 0:05:48So the sharks learn that when it goes from this...
0:05:52 > 0:05:58..down, that there's something up and they'll come up and investigate.
0:05:58 > 0:06:01They just appear like ghosts behind the boat.
0:06:03 > 0:06:05The fishermen, then, has a limited time to get
0:06:05 > 0:06:07the fish in before the sharks will get it.
0:06:34 > 0:06:38Now, for the first time, the theory is being tested with an experiment.
0:06:39 > 0:06:43This speaker plays a recording of a fishing boat in motion.
0:06:51 > 0:06:53The sharks listen, but keep their distance.
0:06:55 > 0:06:58Now it plays the sound of a motor dropping out of gear.
0:07:03 > 0:07:05The dinner bell is ringing
0:07:11 > 0:07:14The sharks instantly rush towards the speaker.
0:07:23 > 0:07:26As Demian suspected, Oceanic Whitetips not only
0:07:26 > 0:07:30have great hearing, they're smart about how they use it.
0:07:30 > 0:07:34People think of sharks as very stupid and have narrow
0:07:34 > 0:07:37repertoire of behaviour, but that is really not true.
0:07:37 > 0:07:41They can adapt to new situations, they can learn,
0:07:41 > 0:07:42they can surprise you.
0:07:46 > 0:07:50Oceanic Whitetips are clever enough to use fishing to provide
0:07:50 > 0:07:52a free meal.
0:07:57 > 0:08:00You can see they'll take the fish right from the boat.
0:08:00 > 0:08:05Whoa! Sorry, I just don't want it to swim on the platform plate with me.
0:08:19 > 0:08:21Sharks have had to be smart to survive.
0:08:25 > 0:08:29And the latest research is revealing that their brainpower could
0:08:29 > 0:08:31help them do much more than just hunt.
0:08:41 > 0:08:44This is a Giant Manta Ray.
0:08:49 > 0:08:51The nomad of the shark family.
0:08:54 > 0:08:56It has the biggest brain of any fish...
0:08:59 > 0:09:02..yet manta rays appear to lead simple lives, following
0:09:02 > 0:09:04and feeding on plankton.
0:09:08 > 0:09:12So, why they need such big brains has baffled scientists for years.
0:09:24 > 0:09:27Off the coast of a volcanic island,
0:09:27 > 0:09:31Dr Andrea Marshall now thinks she has an answer.
0:09:41 > 0:09:44One of the things that really stands out with manta rays
0:09:44 > 0:09:45is their brain size.
0:09:45 > 0:09:48They have the largest brain of any fish and for a long time,
0:09:48 > 0:09:50people weren't really sure why.
0:09:50 > 0:09:52It's not like they have to outwit plankton, you know, it is
0:09:52 > 0:09:56not something that requires a lot of intelligence to eat and we found,
0:09:56 > 0:09:59over time, that it really has probably nothing to do
0:09:59 > 0:10:01with predation at all.
0:10:03 > 0:10:06Like many species of ray, manta's spend most of their time
0:10:06 > 0:10:08travelling solo.
0:10:12 > 0:10:14But, for a few days every year,
0:10:14 > 0:10:19key events like breeding can bring them together in their thousands.
0:10:25 > 0:10:28Andrea thinks it is these social gatherings that could
0:10:28 > 0:10:29explain their big brains.
0:10:37 > 0:10:39Because when it comes to Giant Manta Rays,
0:10:39 > 0:10:44far from following the crowd, they are all very much individuals.
0:10:49 > 0:10:51To show why, she needs to jump in.
0:10:51 > 0:10:54- You guys ready to go?- Always. - Awesome.
0:11:04 > 0:11:06Manta rays are incredibly inquisitive.
0:11:06 > 0:11:08They really engage you underwater.
0:11:08 > 0:11:10Sometimes, they can be quite a long distance away
0:11:10 > 0:11:14but they almost always seem to come in, approach and inspect you.
0:11:24 > 0:11:29This is a completely wild animal and in a location this remote,
0:11:29 > 0:11:32it could well be the first time it's seen a human.
0:11:34 > 0:11:39- Yet it swims straight over for a closer look.- Wow!
0:11:40 > 0:11:42She's a very friendly manta.
0:11:45 > 0:11:49We start to see that certain animals display the same
0:11:49 > 0:11:51type of behaviours every time you encounter it.
0:11:51 > 0:11:55You may encounter an individual that is always shy or hesitant to
0:11:55 > 0:11:58approach you, or, you know, seems very wary.
0:11:59 > 0:12:01Oh!
0:12:03 > 0:12:06Other animals are very bold, almost cheeky, if you will,
0:12:06 > 0:12:10and that is consistent throughout every single encounter.
0:12:14 > 0:12:17So could a manta ray really have an individual character?
0:12:23 > 0:12:28To find out, Andrea has created a profile for every single animal
0:12:28 > 0:12:29she meets.
0:12:31 > 0:12:34The first step is getting a good photograph.
0:12:34 > 0:12:37This looks like a new manta that I haven't seen yet.
0:12:39 > 0:12:43I'm going to take an ID shot of these beautiful spots.
0:12:46 > 0:12:48There we go.
0:12:48 > 0:12:50Very, very cool, she's very cooperative.
0:12:50 > 0:12:54Every single manta ray has a unique spot pattern on its stomach, that
0:12:54 > 0:12:56it has before it's born.
0:12:56 > 0:12:58It doesn't change over the course of its lifetime,
0:12:58 > 0:13:02so we can actually use it as a fingerprint to ID that animal.
0:13:04 > 0:13:07Once she has the profile pictures,
0:13:07 > 0:13:10she adds details of how the manta ray behaved.
0:13:10 > 0:13:14It operates almost like Facebook, in that you're
0:13:14 > 0:13:18putting in information from every single encounter, in a record,
0:13:18 > 0:13:20so when you look back at it, you can see all
0:13:20 > 0:13:24kinds of information about this animal, what its behaviour is like.
0:13:24 > 0:13:27Does it have a specific character?
0:13:27 > 0:13:28You start to realise, over time,
0:13:28 > 0:13:30that they actually do have personalities.
0:13:32 > 0:13:36It's very friendly. It's coming to say hello. Hi.
0:13:36 > 0:13:40Andrea believes that manta ray gatherings could be far more
0:13:40 > 0:13:42complex than previously realised.
0:13:51 > 0:13:54It takes brains to have good social skills.
0:14:03 > 0:14:07But there is something else that makes Andrea think
0:14:07 > 0:14:09MANTA rays could be an Einstein of the ocean.
0:14:10 > 0:14:12Just lets me approach.
0:14:15 > 0:14:19I'll tickle her a little, just to let her know that I'm here. Hi.
0:14:24 > 0:14:26They look at you from different angles.
0:14:26 > 0:14:29They want to understand what you are and then, ultimately, they want to
0:14:29 > 0:14:33figure out how they can interact with you and how they can play with you.
0:14:35 > 0:14:38Playing with another member of a different species is a strong
0:14:38 > 0:14:40sign of intelligence.
0:14:42 > 0:14:45It's something that has never before been seen in a fish.
0:15:01 > 0:15:04They love the bubbles.
0:15:04 > 0:15:08She just loves the spa bath that I'm giving her, underneath her belly.
0:15:09 > 0:15:12It's like tactile stimulation for her.
0:15:17 > 0:15:19You see how she wants more, you know.
0:15:19 > 0:15:23As soon as I leave her, she looks and then turns back to us.
0:15:28 > 0:15:30This is an animal with brains and personality.
0:15:43 > 0:15:46And scientists are now finding signs of personality
0:15:46 > 0:15:49and complex social lives in many other species.
0:16:01 > 0:16:03Lemon sharks make childhood friends.
0:16:06 > 0:16:09By sticking together, they learn how to avoid danger.
0:16:14 > 0:16:18When Great White's meet, they keep the peace using body language.
0:16:24 > 0:16:29Swimming slow and holding their fins at this angle, means all's well.
0:16:37 > 0:16:41The key to understanding sharks is spending time getting to know them.
0:16:45 > 0:16:46And that is no easy matter.
0:16:55 > 0:16:59One species in particular, shows just what scientists are up against.
0:17:07 > 0:17:09Whale sharks are the biggest fish in the sea.
0:17:17 > 0:17:21But in open water, even a 40 ft giant can be hard to find.
0:17:31 > 0:17:35In some parts of the world, Whale sharks gather in huge numbers.
0:17:44 > 0:17:49How they get there and where they go next, is a mystery.
0:18:06 > 0:18:10Here in the Philippines, scientist, Alessandro Ponzo,
0:18:10 > 0:18:13is out every day trying to follow these Whale sharks.
0:18:19 > 0:18:22We don't know much yet about the Whale shark movement.
0:18:22 > 0:18:23That's why we're here, right now.
0:18:23 > 0:18:28They're trying to connect their dots to unravel the mysteries
0:18:28 > 0:18:30around the life of the Whale shark.
0:18:34 > 0:18:37While some of these animals are regular visitors,
0:18:37 > 0:18:39others disappear for months or even years.
0:18:56 > 0:19:00The only way to work out who's who, is to look at their DNA.
0:19:00 > 0:19:02And that means taking a tissue sample.
0:19:06 > 0:19:10They may be harmless filter feeders,
0:19:10 > 0:19:13but catching up with a 20-tonne animal is no mean feat.
0:19:31 > 0:19:32Using only a snorkel,
0:19:32 > 0:19:36Alessandro must dive down to take a small sample from the skin.
0:19:38 > 0:19:40To an animal of this size, it's a pinprick.
0:20:01 > 0:20:06His skin was very, very tough. I shot it twice with maximum power.
0:20:07 > 0:20:09It just cut the first two or three centimetres of the skin,
0:20:09 > 0:20:12but for genetic, it is more than enough.
0:20:16 > 0:20:19Analysis of the DNA reveals that this individual
0:20:19 > 0:20:21is new to the Philippines.
0:20:23 > 0:20:26Like many others, it's appeared from out of the blue.
0:20:29 > 0:20:32It's led scientists to suspect that Whale sharks are making
0:20:32 > 0:20:36huge migrations that can take several years to complete.
0:20:39 > 0:20:41And there is other evidence to back up this theory.
0:20:43 > 0:20:49A study done with satellite tagging, has shown that one animal from here,
0:20:49 > 0:20:51it travelled all the way to Vietnam.
0:20:51 > 0:20:55So, that is more than 3,500 km migration.
0:20:55 > 0:20:58So, we know that this animal moved very far.
0:21:01 > 0:21:05But to uncover the full picture of the whale shark's journey,
0:21:05 > 0:21:07Alessandro can't just rely on technology.
0:21:10 > 0:21:14Sometimes, going back to basics is just as important.
0:21:15 > 0:21:18I've got all the tools I need. A plastic spoon and a net.
0:21:25 > 0:21:27Sharks pick up parasites on their travels.
0:21:31 > 0:21:35Alessandro's task is to try and collect them,
0:21:35 > 0:21:37using just his small plastic spoon.
0:21:47 > 0:21:48It's a delicate procedure.
0:22:13 > 0:22:16It was pretty hard. It's super-exciting.
0:22:16 > 0:22:18This is coming from a new shark.
0:22:18 > 0:22:20New shark usually swim pretty deep,
0:22:20 > 0:22:23so I have to go down five to six metres to be able to take it
0:22:23 > 0:22:25from the upper lips of the animal.
0:22:29 > 0:22:32Every area has its own distinct set of local parasites.
0:22:34 > 0:22:36Like stamps in a passport,
0:22:36 > 0:22:39they can tell Alessandro where the shark has been.
0:22:43 > 0:22:46It's just one of the many techniques scientists are using to
0:22:46 > 0:22:49unravel the mysteries of shark migration.
0:22:54 > 0:22:56Already, they are making big breakthroughs.
0:23:08 > 0:23:10They've discovered that Great Whites
0:23:10 > 0:23:13can swim from Africa to Australia, then back again,
0:23:13 > 0:23:16all in just nine months.
0:23:19 > 0:23:23Even after ten years out at sea, pregnant Lemon sharks find their
0:23:23 > 0:23:27way back to the exact same mangrove where they were born, to give birth.
0:23:35 > 0:23:40Tiger sharks can also make huge international journeys, timing their
0:23:40 > 0:23:47migrations to arrive at the same beach, at the same time, every year.
0:23:54 > 0:23:57The very moment young albatross learning to fly
0:23:57 > 0:23:59are at their most vulnerable.
0:24:25 > 0:24:27Scientists are closer than ever to revealing the remarkable
0:24:27 > 0:24:29abilities of sharks.
0:24:33 > 0:24:37And their discoveries could have surprising benefits for us.
0:24:49 > 0:24:51Many sharks are built for speed...
0:24:53 > 0:24:55..with sleek curves and a powerful tail.
0:24:58 > 0:25:02MUSIC PLAYS
0:25:13 > 0:25:16But what really gives them the edge, is their skin.
0:25:19 > 0:25:22It's covered in microscopic ridges that reduce drag.
0:25:26 > 0:25:31Copying the texture creates the ultimate streamlined service.
0:25:38 > 0:25:42And there's one area where that's been more successful than any other.
0:25:49 > 0:25:51In the world of professional swimming,
0:25:51 > 0:25:54sharks have helped smash Olympic records.
0:26:04 > 0:26:07By wearing swimwear that mimics the texture of shark skin,
0:26:07 > 0:26:10a swimmer creates less drag.
0:26:11 > 0:26:14And that means more speed.
0:26:17 > 0:26:21A huge advantage in a sport where every fraction of a second counts.
0:26:28 > 0:26:31Shark skin clothing helped many athletes to win Olympic medals.
0:26:35 > 0:26:38But it became seen as too big an advantage.
0:26:45 > 0:26:50To keep the sport fair, the swimwear was banned from competitions.
0:26:52 > 0:26:58But in other areas, sharks are still helping us speed things up.
0:27:00 > 0:27:03Synthetic shark skin also reduces friction in the air.
0:27:04 > 0:27:07Tests using it on planes and cars, have shown
0:27:07 > 0:27:11it can save fuel and make journeys faster.
0:27:26 > 0:27:29But their skin doesn't just give sharks speed.
0:27:31 > 0:27:33It also helps them fight disease.
0:27:36 > 0:27:43Almost nothing can stick to shark skin. Not even bacteria.
0:27:48 > 0:27:50Scientists have now imitated the texture
0:27:50 > 0:27:55and created their very own disease fighting material,
0:27:55 > 0:28:00that's being trialled in hospitals and on touch screens.
0:28:01 > 0:28:04It's over 18 times better at preventing
0:28:04 > 0:28:08the spread of deadly superbugs like MRSA.
0:28:17 > 0:28:19And off the coast of California,
0:28:19 > 0:28:23scientists have found a shark with skin so extraordinary,
0:28:23 > 0:28:26it can help fight some of the worst diseases of the 21st century.
0:28:36 > 0:28:40Hidden amongst the kelp forests of Santa Barbara, is a shark that
0:28:40 > 0:28:42could save human lives.
0:28:49 > 0:28:52And the best way to study it, is to wait for dark.
0:28:56 > 0:28:58Professor David Gruber, has created a camera
0:28:58 > 0:29:00that gives him shark vision.
0:29:04 > 0:29:08- And tonight, he's ready to put it to the test.- It is pretty sci-fi.
0:29:08 > 0:29:12It's almost surreal to be entering this alien
0:29:12 > 0:29:14world in the middle of the night.
0:29:20 > 0:29:22This is the first time David has attempted to film these
0:29:22 > 0:29:24sharks in the wild.
0:29:26 > 0:29:27This camera allows us
0:29:27 > 0:29:32to get a little portal into the world of a very shy species of shark.
0:29:36 > 0:29:38All he and his team need to do, is find them.
0:29:46 > 0:29:50This is surface to divers, surface to divers. You guys OK?
0:29:53 > 0:29:55Roger that, I'm happy.
0:29:56 > 0:30:02At night, in murky water, spotting them is not easy.
0:30:16 > 0:30:17It's time to turn on the camera.
0:30:20 > 0:30:23The lights are the same wavelength as moonlight.
0:30:26 > 0:30:30And the lens works like a shark's eye.
0:30:32 > 0:30:34These are shy sharks.
0:30:34 > 0:30:36They camouflage very nicely into the rock crevices,
0:30:36 > 0:30:41so, you can be swimming over a shark and almost not even notice it.
0:30:41 > 0:30:45But looking through the viewfinder, David now has shark vision.
0:30:45 > 0:30:47INDISTINCT TALKING
0:30:49 > 0:30:53This is the best chance he has of seeing the shark he's after.
0:30:55 > 0:30:58INDISTINCT TALKING
0:31:00 > 0:31:03This is it. A Swell shark.
0:31:08 > 0:31:10A shark that glows in the dark.
0:31:27 > 0:31:28It's known as bio-fluorescence.
0:31:39 > 0:31:43To see it, you need the shark's highly specialised eyes...
0:31:45 > 0:31:47..or this camera.
0:31:54 > 0:31:57Without them, this is all you see.
0:32:09 > 0:32:14Wow, amazing. This is super-exciting for us.
0:32:14 > 0:32:18This is the first time that we've got this footage in the wild.
0:32:18 > 0:32:21This is a world that these sharks have been seeing
0:32:21 > 0:32:24for millions of years and we're finally just tuning in.
0:32:28 > 0:32:31But why would a shark need to glow bright green?
0:32:33 > 0:32:37In all honesty, we're not exactly sure why these sharks
0:32:37 > 0:32:39are fluorescent.
0:32:39 > 0:32:43One of the theories is, they are using this as a special secret
0:32:43 > 0:32:48signal in which male and female Swell sharks can quickly be
0:32:48 > 0:32:53able to find each other, mate and then go back into hiding.
0:32:53 > 0:32:56It's like a plane flying into Las Vegas in the middle of the night,
0:32:56 > 0:32:58you know, you can see it from miles away.
0:33:02 > 0:33:05These small and timid sharks are vulnerable to predation.
0:33:07 > 0:33:10Having a secret way to signal to each other, could be
0:33:10 > 0:33:12the perfect way to stay safe.
0:33:15 > 0:33:18But this shark is attracting the attention of scientists
0:33:18 > 0:33:19for another reason.
0:33:26 > 0:33:29Its skin could transform the treatment of life-threatening
0:33:29 > 0:33:33diseases like cancer and Alzheimer's.
0:33:40 > 0:33:44The chemical that makes the shark glow can be used to track
0:33:44 > 0:33:45unhealthy cells.
0:33:48 > 0:33:51By following how they spread around the body, it is
0:33:51 > 0:33:53possible to study how diseases work...
0:33:55 > 0:33:58..and see what drugs work best at stopping them.
0:34:01 > 0:34:04So David's natural home is not out diving in kelp forests,
0:34:04 > 0:34:06but in the lab.
0:34:12 > 0:34:15Now, by finding this whole new reservoir of biological
0:34:15 > 0:34:17fluorescence in sharks,
0:34:17 > 0:34:22we're hoping this can be used as the new tool that can better understand
0:34:22 > 0:34:26ourselves on an even deeper level and, perhaps, even save lives.
0:34:29 > 0:34:32Researchers are now eager to find out how many other sharks glow...
0:34:34 > 0:34:37..and see if they too have life-saving potential.
0:34:55 > 0:34:56Unfortunately,
0:34:56 > 0:34:59not everything scientists are discovering is good news.
0:35:02 > 0:35:04Many sharks are in serious trouble.
0:35:10 > 0:35:13Almost a quarter of all species are now facing extinction.
0:35:21 > 0:35:23The main threat is commercial fishing.
0:35:25 > 0:35:28These are animals with a high price on their heads.
0:35:33 > 0:35:36In Asia, there is a huge appetite for their meat
0:35:36 > 0:35:38and highly prized fins.
0:35:40 > 0:35:43Shark fin soup is a popular Chinese delicacy.
0:35:45 > 0:35:48Demand for the key ingredient has had a devastating
0:35:48 > 0:35:50effect on shark numbers.
0:35:58 > 0:36:02In an ocean full of lines, hooks and nets,
0:36:02 > 0:36:04sharks and rays don't stand much chance.
0:36:07 > 0:36:10A top predator has become prey.
0:36:15 > 0:36:20100 million sharks are estimated to be killed every year.
0:36:22 > 0:36:26The fear is that entire species will soon be gone.
0:36:29 > 0:36:33In some cases, before we even knew they existed.
0:36:48 > 0:36:51To date, we know of over 500 species of shark.
0:36:57 > 0:37:01But this man thinks there could be many more still to find.
0:37:03 > 0:37:07Dr David Ebert has dedicated his career to identifying every
0:37:07 > 0:37:11single species of shark before it's too late.
0:37:14 > 0:37:17It's an assignment that has taken him around the globe.
0:37:28 > 0:37:31Most of us who are young children, usually get a book on dinosaurs
0:37:31 > 0:37:34or sharks and we get really excited about it.
0:37:34 > 0:37:37Most kids grow out of that phase, but people like myself,
0:37:37 > 0:37:40you never grow out of it, it's a lifelong fascination.
0:37:43 > 0:37:47So far, David has found 24 new species,
0:37:47 > 0:37:49often in unexpected places.
0:37:53 > 0:37:55Some of his most important discoveries have been
0:37:55 > 0:38:00made on dry land, here, in the fish markets of Taiwan.
0:38:20 > 0:38:24Over 180 different species of shark have been found off this coast,
0:38:24 > 0:38:26more than anywhere else in the world.
0:38:34 > 0:38:38Sharks are a big part of the local diet.
0:38:42 > 0:38:46If you're looking for new sharks, this is the place to come.
0:38:53 > 0:38:56You can understand how people might be appalled by what they see.
0:38:56 > 0:39:00You're going to see a lot of dead fish,
0:39:00 > 0:39:04so you just focus on the work you're here to do and do the best you can.
0:39:09 > 0:39:11Any arrival could be something new.
0:39:11 > 0:39:15You have to be moving all the time because something could show up
0:39:15 > 0:39:18somewhere and they could be gone very quickly.
0:39:18 > 0:39:21You hear the whistle in the background, that is
0:39:21 > 0:39:25the auction going on, so fish will show up and fish will be gone.
0:39:25 > 0:39:27You need to always be moving and looking constantly
0:39:27 > 0:39:29to find what you're looking for.
0:39:30 > 0:39:32It's almost like a CSI investigation,
0:39:32 > 0:39:36trying to figure out what these different species are,
0:39:36 > 0:39:39trying to identify them and see if there's something new.
0:39:46 > 0:39:49New species are often found where nobody would think of looking.
0:39:54 > 0:39:57These piles of trash fish like this are the best places to find
0:39:57 > 0:40:00these little-known lost shark.
0:40:00 > 0:40:01It might seem like a strange place
0:40:01 > 0:40:03but it's, like, one of those dirty jobs.
0:40:03 > 0:40:06You have to go looking where most people are not going to bother to go.
0:40:09 > 0:40:14David is one of the few people looking out for these tiny sharks.
0:40:14 > 0:40:17These are the kind of things that are actually species that are really
0:40:17 > 0:40:21important to the ecosystem but no-one pays any attention to these things.
0:40:27 > 0:40:31Years of searching for sharks mean David's expert eye is
0:40:31 > 0:40:34quick to spot anything unusual.
0:40:34 > 0:40:37And he's found a real rarity.
0:40:38 > 0:40:40This is a Frilled shark.
0:40:40 > 0:40:44Really very cool and interesting and a bizarre species to see.
0:40:44 > 0:40:46It's the kind of thing that people don't often think
0:40:46 > 0:40:50of as being a shark, just because it's so weird and so different.
0:40:52 > 0:40:56It may look odd, but this shark is adapted for life in the deep sea.
0:40:58 > 0:41:00Its appearance here is a worrying sign.
0:41:02 > 0:41:06Coming back to this market repeatedly over the last 25 years,
0:41:06 > 0:41:09I start seeing deep sea species we didn't see before.
0:41:11 > 0:41:13It indicates they're fishing much deeper.
0:41:15 > 0:41:18Speaking to some of my fishing contacts here, they tell me
0:41:18 > 0:41:20they fish one to 200m 25 years ago.
0:41:20 > 0:41:23Now, they are fishing down to 800, 900m.
0:41:31 > 0:41:34The deep ocean is the most mysterious unexplored
0:41:34 > 0:41:36habitat on the planet.
0:41:37 > 0:41:40Scientists believe this is where many new shark
0:41:40 > 0:41:41species could be found.
0:41:49 > 0:41:52What we know about sharks is just the tip of the iceberg.
0:42:01 > 0:42:05For many species, even the most basic information is still missing.
0:42:10 > 0:42:12Scientists are racing to fill in the blanks.
0:42:24 > 0:42:29One species they're most concerned about, is the Oceanic Whitetip.
0:42:31 > 0:42:35They were once one of the most common sharks on the planet...
0:42:36 > 0:42:39..until their distinctive large fins attracted
0:42:39 > 0:42:41the attention of the shark fin trade.
0:42:43 > 0:42:46It's amazing that we can take an animal that was super common
0:42:46 > 0:42:49and just in the space of a few decades, fish them down to the point
0:42:49 > 0:42:53where there's real great concern that they'll exist in the future.
0:42:58 > 0:43:00By understanding more about their daily lives,
0:43:00 > 0:43:04Demian and his team can come up with a strategy for their protection.
0:43:05 > 0:43:08We learn something new about these sharks every time
0:43:08 > 0:43:12we come out here, because that is how little we know about them.
0:43:14 > 0:43:15It's coming towards us.
0:43:19 > 0:43:23Here in the Bahamas, they've now banned shark fishing,
0:43:23 > 0:43:26so it is one of the few places scientists can still find
0:43:26 > 0:43:28and study Oceanic Whitetips.
0:43:32 > 0:43:35First, one is lured in with bait.
0:43:36 > 0:43:41Then, floats are attached to slow it down and tire it out.
0:43:41 > 0:43:43They've got it.
0:43:45 > 0:43:48Now it can be handled without being hurt.
0:43:48 > 0:43:50There, you see the balls, just like Jaws.
0:43:57 > 0:44:02So, this shark is going to have a lot of activity going on around it.
0:44:02 > 0:44:04We're going to learn a lot about these sharks
0:44:04 > 0:44:06just from looking at this one individual.
0:44:13 > 0:44:17They just measured the shark and it's actually 285 cm, which is, I think,
0:44:17 > 0:44:20the biggest male we've ever measured here, so this is really exciting.
0:44:20 > 0:44:23It's like King Kong of the Oceanic Whitetips.
0:44:26 > 0:44:28As soon as they have its vital stats,
0:44:28 > 0:44:32the shark is turned upside down,
0:44:32 > 0:44:36a position known to make sharks feel calm.
0:44:37 > 0:44:41Blood and DNA samples or quickly taken, before, finally,
0:44:41 > 0:44:46the shark is kitted out with the very latest technology.
0:44:46 > 0:44:47He's like the Robocop of sharks right now.
0:44:47 > 0:44:49It's got a couple of different tags.
0:44:49 > 0:44:52It's actually carrying about 20,000 worth of tags.
0:44:56 > 0:45:00In a few months, the gadgets will fall off,
0:45:00 > 0:45:04leaving the shark none the wiser of the important mission it was on.
0:45:10 > 0:45:12These instruments give us this window into a world
0:45:12 > 0:45:16we know very little about, the world of the Oceanic Whitetip.
0:45:18 > 0:45:21We're going to learn from these instruments where they go,
0:45:21 > 0:45:24how far they travel, their swimming speed, their diving behaviour,
0:45:24 > 0:45:25their feeding behaviour.
0:45:32 > 0:45:34Demian needs to know where the sharks go
0:45:34 > 0:45:37once they leave the safety of the Bahamas.
0:45:42 > 0:45:44Like many sharks,
0:45:44 > 0:45:47they undertake huge migrations that may take them through very
0:45:47 > 0:45:53dangerous waters and their loss could have terrible consequences.
0:45:56 > 0:45:59Sharks are important in the ocean ecosystem.
0:45:59 > 0:46:02They're the top predators, like lions and tigers, wolves,
0:46:02 > 0:46:06and we know when we have taken lions and tigers and wolves
0:46:06 > 0:46:08out of the land ecosystems.
0:46:08 > 0:46:09We've seen big changes.
0:46:12 > 0:46:14We don't want those changes to happen in the ocean.
0:46:25 > 0:46:28But it's hard to get people to care about sharks
0:46:28 > 0:46:30if they're afraid of them.
0:46:41 > 0:46:45To some, this is the stuff of nightmares.
0:46:53 > 0:46:57But do sharks really deserve a deadly reputation?
0:47:01 > 0:47:05There's no evidence to suggest sharks deliberately target humans.
0:47:09 > 0:47:13They've little interest in anything other than their natural prey.
0:47:17 > 0:47:20Most attacks are a case of mistaken identity,
0:47:20 > 0:47:22which is why they're so rare.
0:47:35 > 0:47:40You're over 50,000 times more likely to drown than be killed by a shark.
0:47:48 > 0:47:50Despite their statistics,
0:47:50 > 0:47:53some people still see sharks as the enemy.
0:47:58 > 0:48:01Many countries go to great lengths to keep sharks
0:48:01 > 0:48:02away from their beaches.
0:48:08 > 0:48:12Nets and lines trap and kill animals that come in too close to shore.
0:48:19 > 0:48:22Australia even resorted to shooting sharks,
0:48:22 > 0:48:24culling 50 in a matter of months.
0:48:31 > 0:48:35Scientists are now urgently looking for an alternative solution.
0:48:39 > 0:48:42Here in Cape Town, they're close to finding it.
0:48:49 > 0:48:52No other city has such a high concentration of sharks
0:48:52 > 0:48:53right on its doorstep.
0:49:00 > 0:49:02Every year, swimmers
0:49:02 > 0:49:05and surfers share the water with up to 700 Great White sharks.
0:49:10 > 0:49:14But thanks to science, they are learning how to live with them.
0:49:15 > 0:49:17Shark shot.
0:49:24 > 0:49:28Dr Alison Kock has spent her working life studying
0:49:28 > 0:49:29the sharks in this bay.
0:49:29 > 0:49:32They are the most incredible sharks.
0:49:32 > 0:49:37They've got power, this raw power but this grace. Ah, gorgeous.
0:49:40 > 0:49:42We get to know them really well.
0:49:42 > 0:49:46We get to know their behaviour around the boat. It's very individual.
0:49:54 > 0:49:57Now, by understanding what makes these sharks tick,
0:49:57 > 0:50:01Alison is looking for ways to keep people safe.
0:50:01 > 0:50:03- I'm ready.- Coming in from the left.
0:50:03 > 0:50:09Closer, closer. OK, here we go.
0:50:09 > 0:50:10Got it.
0:50:10 > 0:50:12By tagging and tracking the sharks,
0:50:12 > 0:50:16she's been working out where these Great White's hunt.
0:50:16 > 0:50:20I never ever feel nervous around the sharks like this, because more
0:50:20 > 0:50:22than likely, if I fell in now,
0:50:22 > 0:50:25the shark would probably get a fright and swim away,
0:50:25 > 0:50:28so, it is more about trying to get the science done.
0:50:30 > 0:50:32Her research has shown that where sharks hunt,
0:50:32 > 0:50:34is far from random.
0:50:38 > 0:50:42They use different parts of the bay depending on the time of year.
0:50:46 > 0:50:48So, by making people aware of the danger zones...
0:50:50 > 0:50:53..she's hoping to minimise the risk of attack.
0:50:57 > 0:50:59Now, in winter, the sharks are focusing
0:50:59 > 0:51:03all their attention on the offshore islands full of young seals.
0:51:05 > 0:51:07By watching how the sharks hunt here,
0:51:07 > 0:51:12Alison has learned what time of day an attack is most likely.
0:51:16 > 0:51:20This is Frank. This is our seal decoy and he really helps us
0:51:20 > 0:51:24to try and understand how the sharks are hunting here around the island.
0:51:24 > 0:51:27He's already got a couple of war wounds heal from a small shark.
0:51:27 > 0:51:29Good luck, Frank.
0:51:32 > 0:51:35Frank plays the role of a vulnerable lone seal...
0:51:38 > 0:51:40..just what the sharks are looking for.
0:51:44 > 0:51:49Let's make one turn back down to the boat again.
0:51:49 > 0:51:53But even after hours of towing, they show no signs of interest.
0:51:59 > 0:52:02Alison thinks they're biding their time.
0:52:02 > 0:52:08Seals are incredibly smart and incredibly agile, so the tactics
0:52:08 > 0:52:12the White Sharks have to use are stealth, to ambush attack the seals.
0:52:13 > 0:52:14If they don't do that,
0:52:14 > 0:52:17they have very little chance of actually catching the seals.
0:52:20 > 0:52:24In broad daylight, it is hard for a shark to make a surprise attack.
0:52:30 > 0:52:33So, by day, Frank stays safe.
0:52:36 > 0:52:43But when the sun is low, sharks use the darker water to stay hidden.
0:52:51 > 0:52:55This is when seals, and Frank, are most at risk.
0:53:03 > 0:53:06Brilliant! He got it pretty hard.
0:53:08 > 0:53:12The shark cleared and re-entered the water in less than a second.
0:53:18 > 0:53:24Ah, that is a massive shark. That's an over four metre shark,
0:53:24 > 0:53:29and it really hit the decoy right in the middle there.
0:53:29 > 0:53:31They come from below and behind.
0:53:38 > 0:53:41Frank demonstrates how sharks use low light
0:53:41 > 0:53:44and stealth tactics to their advantage,
0:53:44 > 0:53:46behaviour that Alison thinks all swimmers
0:53:46 > 0:53:48and surfers should understand.
0:53:49 > 0:53:52We can say, look, this is a risky time,
0:53:52 > 0:53:54you should rather avoid this time.
0:53:54 > 0:53:57That's a really simple way to keep people
0:53:57 > 0:54:00and sharks out of each other's way for a short amount of time.
0:54:05 > 0:54:09By using science, sharks and humans can share the sea.
0:54:16 > 0:54:18I think that what we're showing here in Cape Town,
0:54:18 > 0:54:20is that there are other ways.
0:54:20 > 0:54:25You can find ways to live with white sharks that doesn't involve
0:54:25 > 0:54:28ruining the ecosystem and doesn't involve the killing of sharks.
0:54:31 > 0:54:33It is a little bit easier to manage people,
0:54:33 > 0:54:36than it is a big two tonne white shark.
0:54:41 > 0:54:44What Alison and many other scientists hope, is that the more
0:54:44 > 0:54:50people get to know sharks, the less reason they'll have to fear them.
0:55:03 > 0:55:06With all the advances in science, with all of the things that
0:55:06 > 0:55:09we're learning about these animals, I hope that science can show
0:55:09 > 0:55:11people that these are not the animals
0:55:11 > 0:55:13that they've been betrayed to be.
0:55:13 > 0:55:16These are really, really special and incredibly, I think,
0:55:16 > 0:55:19charismatic animals, if you give them a chance.
0:55:21 > 0:55:24Changing attitudes towards sharks could play a big
0:55:24 > 0:55:26role in their future.
0:55:26 > 0:55:30There has been a lot of activity, just recently, that inspires me
0:55:30 > 0:55:34with a lot of hope with starting to have the will from the people
0:55:34 > 0:55:36wanting to see sharks protected.
0:55:48 > 0:55:49For the first time,
0:55:49 > 0:55:52people are queueing up to swim with sharks, not hunt them.
0:55:59 > 0:56:01Shark tourism is becoming big business.
0:56:05 > 0:56:08Countries like the Philippines and Fiji have realised
0:56:08 > 0:56:11that sharks are worth more alive than dead.
0:56:19 > 0:56:22And the more people are learning to love sharks,
0:56:22 > 0:56:24the less interest they have in eating them.
0:56:29 > 0:56:32The price of shark fins has dropped, as more
0:56:32 > 0:56:35and more restaurants take shark fin soup off the menu.
0:56:45 > 0:56:49In Australia, people came out in their masses to stand
0:56:49 > 0:56:52up for sharks and protest against a cull.
0:56:59 > 0:57:04At last, we could be at a turning point for sharks and rays.
0:57:06 > 0:57:09Scientists are not only revealing their powerful sensors,
0:57:09 > 0:57:17their intelligence and their complex social lives,
0:57:17 > 0:57:21scientists are also changing attitudes
0:57:21 > 0:57:26and convincing the world that our oceans need sharks.