0:00:27 > 0:00:31Today, we're on the island of Tiree in the Inner Hebrides,
0:00:31 > 0:00:35looking to get up close and personal with the shark.
0:00:35 > 0:00:37It's the ocean's greatest hunter,
0:00:37 > 0:00:40evolved over 450 million years
0:00:40 > 0:00:43to thrive in almost every ocean on the planet.
0:00:43 > 0:00:47Including ours. There are sharks right here in UK waters
0:00:47 > 0:00:49but that's not all.
0:00:49 > 0:00:52Some can grow up to a staggering ten metres in length.
0:00:52 > 0:00:54That's as big as a bus.
0:00:54 > 0:00:57And some of those big fellows are right here
0:00:57 > 0:00:59because this is one of the best places
0:00:59 > 0:01:02to spot the UK's biggest shark species.
0:01:02 > 0:01:06There are actually over 30 different species of shark in Scottish waters
0:01:06 > 0:01:09and we're hoping to catch up with some of the jaws
0:01:09 > 0:01:10that surround our shores.
0:01:10 > 0:01:14But, don't worry, these are not fish to be feared.
0:01:14 > 0:01:17'Later, I'll be proving that as I head to Cornwall,
0:01:17 > 0:01:21'hoping to come face to fin with the beautiful blue shark.'
0:01:22 > 0:01:23Oh, she's right here.
0:01:23 > 0:01:26'I'll be tracking down evidence of baby sharks
0:01:26 > 0:01:28'on one of our most popular beaches.'
0:01:28 > 0:01:32Oh, guys, guys, look, look, look! CHILDREN ALL TALK AT ONCE
0:01:32 > 0:01:37'And every day, we're joined by intrepid wildlife cameraman Richard Taylor-Jones,
0:01:37 > 0:01:40'who today is investigating the relationship
0:01:40 > 0:01:43'between our ocean's biggest and smallest creatures.'
0:01:43 > 0:01:46Their life depends upon all these lives.
0:01:46 > 0:01:48'We'll also be joined by some familiar faces
0:01:48 > 0:01:52'sharing their best past experiences of marine wildlife.'
0:01:52 > 0:01:55But, first, Richard's going to give us the lowdown
0:01:55 > 0:01:59on some of the amazing shark species living in UK waters.
0:01:59 > 0:02:01'For the last 20 years,
0:02:01 > 0:02:02'I've been working as a cameraman,
0:02:02 > 0:02:05'filming wildlife all over the British Isles.
0:02:05 > 0:02:08'When it comes to capturing shots of sea life,
0:02:08 > 0:02:11'you definitely need patience and a fair bit of luck.
0:02:17 > 0:02:20'The majority of our sharks are resident
0:02:20 > 0:02:21'so they're here all year round.
0:02:23 > 0:02:26'And that's mainly because there's food and a lot of it
0:02:26 > 0:02:28'and they have different ways of finding it.
0:02:30 > 0:02:33'Bizarre-looking angel sharks inhabit the depths,
0:02:33 > 0:02:37'waiting for an unsuspecting fish to pass.
0:02:41 > 0:02:45'Bottom-dwelling smooth-hounds lurk around the shallows,
0:02:45 > 0:02:47'hunting out hermit crabs.
0:02:49 > 0:02:53'And huge basking sharks sweep the open ocean for plankton.
0:02:55 > 0:02:58'Not all our sharks are here year-round.
0:02:58 > 0:02:59'Some are seasonal visitors.
0:03:01 > 0:03:05'The beautiful blue shark can be seen from June to September.
0:03:07 > 0:03:11'During those summer months, the mako shark pays us a visit too.
0:03:13 > 0:03:15'It's the fastest shark in the ocean
0:03:15 > 0:03:17'so isn't quite as easy to spot.
0:03:21 > 0:03:25'Skates and rays are basically flattened sharks.
0:03:29 > 0:03:31'Instead of having boned skeletons,
0:03:31 > 0:03:35'skates, rays and sharks are made up of cartilage.
0:03:35 > 0:03:37'This is what defines them as a group.
0:03:40 > 0:03:43'Sharks don't have the best of reputations
0:03:43 > 0:03:47'but they actually play a very important role in our seas.
0:03:48 > 0:03:50'Whatever they eat,
0:03:50 > 0:03:54'they are at the top of the food chain in virtually every location.
0:03:54 > 0:03:59'This means they keep populations of other fish in proper proportion.
0:04:00 > 0:04:04'Without them, our seas would be a very different place.'
0:04:08 > 0:04:13Sharks, of course, unlike dolphins, are not mammals but fish.
0:04:13 > 0:04:16They don't have lungs that breathe air.
0:04:16 > 0:04:18Instead, they have gills that extract oxygen
0:04:18 > 0:04:21from the water as it passes through them.
0:04:21 > 0:04:24But, not all sharks share exactly the same biology,
0:04:24 > 0:04:27especially when it comes to reproduction.
0:04:27 > 0:04:31Some sharks give birth to live young, whereas others lay eggs,
0:04:31 > 0:04:34as Lindsey found out when she went to Devon.
0:04:35 > 0:04:40'You may think seeing a shark on a trip to the beach is highly unlikely
0:04:40 > 0:04:43'but amazingly, they're not that far away.'
0:04:43 > 0:04:48In fact, right now, I'm just metres from sharks
0:04:48 > 0:04:50and this curious little object is my evidence.
0:04:52 > 0:04:54'But, what is it?'
0:04:54 > 0:04:56A bit of seaweed.
0:04:56 > 0:04:57- Seaweed.- Seaweed?
0:04:59 > 0:05:01Shark's egg?
0:05:01 > 0:05:04'Emma's got it right. This is a shark's eggcase,
0:05:04 > 0:05:07'sometimes called a mermaid's purse.
0:05:07 > 0:05:10'Cat Gordon, from the Shark Trust, explains more.'
0:05:10 > 0:05:12So, these eggcases are laid in pairs
0:05:12 > 0:05:14and there'll be a yolk sac inside there
0:05:14 > 0:05:16that will give the embryo everything it needs
0:05:16 > 0:05:19and then, as it grows, it'll kind of fill the eggcase
0:05:19 > 0:05:22until it's ready to hatch out of this opening up here.
0:05:22 > 0:05:24- Just here?- Just there, yeah.
0:05:24 > 0:05:26So, the young will emerge as a fully formed miniature version
0:05:26 > 0:05:30of the adult that's ready to swim off into the sea and fend for itself
0:05:30 > 0:05:33and this empty eggcase can get dislodged quite easily
0:05:33 > 0:05:35and that's when it's washed up onto the beach.
0:05:39 > 0:05:42'Two of our British sharks,
0:05:42 > 0:05:43'a few rays
0:05:43 > 0:05:46'and all of our skates lay eggcases.
0:05:48 > 0:05:51'You can tell the species by the shape, colour and size,
0:05:51 > 0:05:53'just like birds' eggs.'
0:05:53 > 0:05:56We've got the two on the end here that are the shark species
0:05:56 > 0:05:58so that's the small spotted cat shark
0:05:58 > 0:06:00and then we've got the nursehound
0:06:00 > 0:06:02that's got those curly tendrils on the ends.
0:06:02 > 0:06:05And then these ones are all our skates and our rays
0:06:05 > 0:06:08so you can see they've got this pointed horn on each corner
0:06:08 > 0:06:09and then we've got this one.
0:06:09 > 0:06:12Look at that beast, that's huge!
0:06:12 > 0:06:14It's bigger than my hand, what's this?
0:06:14 > 0:06:15So, that's a flapper skate eggcase.
0:06:15 > 0:06:18It was previously called the common skate
0:06:18 > 0:06:20and that's from one of the largest skates in the world
0:06:20 > 0:06:22which gets a wingspan of about 2.5 metres across.
0:06:22 > 0:06:24Can I find this here?
0:06:24 > 0:06:25Not down here, no.
0:06:25 > 0:06:27It used to be common all the way around the country
0:06:27 > 0:06:29but now there's only a few strongholds left
0:06:29 > 0:06:31up on the west coast of Scotland and around Orkney.
0:06:31 > 0:06:33That's massive.
0:06:33 > 0:06:38'I may not be able to find a flapper skate eggcase here on Wembury Beach
0:06:38 > 0:06:41'but I've got a good chance of finding the other species.
0:06:43 > 0:06:46'Shark, skate and ray populations are fluctuating
0:06:46 > 0:06:50'so the Shark Trust set up a project called The Great Eggcase Hunt,
0:06:50 > 0:06:54'encouraging everyone in the UK to get out and see what they can find.
0:06:55 > 0:06:58'The information helps the Shark Trust understand
0:06:58 > 0:07:01'how many sharks we have and where they breed.
0:07:03 > 0:07:07'Today, I've got some help from the children of Wembury Primary School.'
0:07:07 > 0:07:09Where should we be looking and what are we looking for?
0:07:09 > 0:07:12OK, so, all of this seaweed makes up the strand line along the beach.
0:07:12 > 0:07:15That's where everything gets washed in from the sea
0:07:15 > 0:07:17so we need to look in there for all of these eggcases.
0:07:17 > 0:07:20- Are we ready? CHILDREN:- Yeah!- Yeah? Let's go.
0:07:23 > 0:07:25'The best time to look is after stormy weather,
0:07:25 > 0:07:29'when lots of seaweed and debris is thrown up on the beach.'
0:07:31 > 0:07:33Oh, guys, guys, look, look, look!
0:07:33 > 0:07:37- I moved it.- Did you find it?- Yeah. - You moved it from under here?
0:07:37 > 0:07:39It's got the curly bit on the end.
0:07:39 > 0:07:42Given the size of that one, which one do you think that might be?
0:07:42 > 0:07:44It could be this one here.
0:07:44 > 0:07:47Exactly, so yeah, that one is a nursehound eggcase.
0:07:47 > 0:07:50It's a little bit broken up but it's a nursehound's.
0:07:50 > 0:07:52'Finding this eggcase could be proof
0:07:52 > 0:07:55'that nursehounds breed right here off Wembury Beach
0:07:55 > 0:07:58'so Cat's taking me into the water and if we're lucky enough,
0:07:58 > 0:08:02'we might find an eggcase with a live embryo inside.
0:08:03 > 0:08:06'These shallow waters are beautiful.
0:08:08 > 0:08:09'As we swim through them,
0:08:09 > 0:08:13'we see a rich variety of seaweeds in all shapes and colours.
0:08:15 > 0:08:16'Throughout spring and summer,
0:08:16 > 0:08:19'the female will deposit the eggs amongst these weeds.
0:08:21 > 0:08:24'Eggcases themselves aren't that camouflaged
0:08:24 > 0:08:26'but algae will grow on them,
0:08:26 > 0:08:28'making them hard to find.
0:08:32 > 0:08:34'And sadly, that's the case today.
0:08:34 > 0:08:38'But other snorkellers have found them right here at Wembury
0:08:38 > 0:08:40'and this is what they saw.
0:08:42 > 0:08:44'These are nursehound eggs.
0:08:45 > 0:08:47'When held up to the sunlight,
0:08:47 > 0:08:50'you can even see the shark developing inside.
0:08:53 > 0:08:57'It's remarkable to think that just metres from this busy beach
0:08:57 > 0:08:59'is a shark nursery.'
0:08:59 > 0:09:01If you want to have a close encounter with a shark
0:09:01 > 0:09:04in UK waters, then get down to a beach near you
0:09:04 > 0:09:06and start looking for mermaid's purses.
0:09:06 > 0:09:08Join in the Great Eggcase Hunt.
0:09:12 > 0:09:16And I'm delighted to say that lots of you have been doing just that.
0:09:16 > 0:09:20The map that Lindsey has here shows all the eggcase sightings
0:09:20 > 0:09:23reported since 2003.
0:09:23 > 0:09:25Lindsey, is there anything in our neck of the woods?
0:09:25 > 0:09:29Take a look at this. This is Tiree, round about here.
0:09:29 > 0:09:31- Under that splodge. - That's right, and guess what?
0:09:31 > 0:09:35On the 7th of July, somebody found a giant flapper skate eggcase,
0:09:35 > 0:09:39so that means they're living just off the shores here.
0:09:39 > 0:09:42And, Lindsey, I've just got to show off a little bit here
0:09:42 > 0:09:44because just a couple of weeks ago,
0:09:44 > 0:09:47I was out here in Gunna Sound with my sister and her family
0:09:47 > 0:09:51and my brother-in-law shot this rather amazing footage.
0:09:51 > 0:09:53- Wow!- Have a look.
0:09:53 > 0:09:55- Gosh, it's huge!- It's a big one.
0:09:55 > 0:09:59We saw six huge basking sharks, just metres from where I am now.
0:10:00 > 0:10:05And just a few days ago, my son Oscar took these underwater images while
0:10:05 > 0:10:10snorkelling, and grabbed this shot of a basking shark actually breaching.
0:10:13 > 0:10:15It looks stunning.
0:10:15 > 0:10:18It was a really wonderful thing to see, but I have to say,
0:10:18 > 0:10:21we were very lucky because, in fact, nationwide,
0:10:21 > 0:10:24basking shark sightings have been really down this summer.
0:10:24 > 0:10:29I asked Richard Taylor-Jones to try and find out why.
0:10:29 > 0:10:31Well, it's all down to what they
0:10:31 > 0:10:34like to feed on, which is contained
0:10:34 > 0:10:36within this seemingly clear seawater
0:10:36 > 0:10:39I have in this beaker. It's plankton.
0:10:39 > 0:10:43And, believe it or not, within this beaker alone, there are more
0:10:43 > 0:10:46individual creatures than there are people in the whole of the UK.
0:10:46 > 0:10:51Effectively, what you have in here is a whole living ecosystem,
0:10:51 > 0:10:55a Maasai Mara of herbivores eating plants
0:10:55 > 0:10:58and carnivores eating the herbivores.
0:10:58 > 0:11:02It is a quite incredible living soup.
0:11:02 > 0:11:07Astonishingly, it's this invisible soup supper that sustains the mighty
0:11:07 > 0:11:10basking shark and I would love to see this
0:11:10 > 0:11:14micro world that they are so dependent on.
0:11:14 > 0:11:18So, I've come to a plankton research laboratory in Plymouth to
0:11:18 > 0:11:20meet with Dr Nick Owens.
0:11:20 > 0:11:23He and his team have a raft of powerful microscopes that
0:11:23 > 0:11:27enable them to see plankton in incredible detail.
0:11:27 > 0:11:31What I'd really like to do is take this seemingly empty beaker
0:11:31 > 0:11:35and actually get some shots of the live animals in here.
0:11:35 > 0:11:38- Could we sort of use this set-up to do that?- Yeah, most certainly.
0:11:38 > 0:11:40Yeah, let's do that.
0:11:40 > 0:11:41Where do we start?
0:11:41 > 0:11:45We start by getting some of that out into a little dish like this
0:11:45 > 0:11:48- and under the microscope. - OK. Well, let's get to work.
0:11:48 > 0:11:51By using specialist kit, I can attach my cameras to the
0:11:51 > 0:11:55microscopes and start to film the plankton in incredible detail.
0:11:55 > 0:11:57And this micro world comes to life.
0:11:59 > 0:12:01Oh, my goodness me! Masses of stuff!
0:12:01 > 0:12:04Yeah, all sorts of things whizzing around.
0:12:04 > 0:12:07One in the middle there, you can see it's got a...
0:12:07 > 0:12:12- That's one of these copepods.- Mm-hm.
0:12:12 > 0:12:15And these are favourite food of young fish,
0:12:15 > 0:12:19even up to those basking sharks you've been talking about.
0:12:19 > 0:12:22That's absolutely amazing.
0:12:22 > 0:12:26- Can you see that? Is that...? The pulsating...- That's...
0:12:26 > 0:12:29- Is that a little jellyfish? - That's a little jellyfish.- Wow!
0:12:29 > 0:12:33This is just fascinating, being in a
0:12:33 > 0:12:36lab and seeing what the basking sharks are
0:12:36 > 0:12:41feeding on, that their life depends upon all these lives in here.
0:12:41 > 0:12:42Yeah.
0:12:42 > 0:12:45So, could it be that this plankton
0:12:45 > 0:12:48is affecting our basking sharks this summer?
0:12:48 > 0:12:50There has been an ongoing study
0:12:50 > 0:12:53since the 1930s that could help get some answers.
0:12:53 > 0:12:57The study uses an ingenious collecting machine that is
0:12:57 > 0:12:59towed behind commercial ships.
0:12:59 > 0:13:04140,000 miles have been covered this year alone.
0:13:04 > 0:13:07I'm going to join operations manager Lance Gregory to pick up
0:13:07 > 0:13:11a recorder from the Plymouth to Roscoff ferry.
0:13:11 > 0:13:14Lance, this is a pretty heavy looking piece of equipment.
0:13:14 > 0:13:16How do you actually get it over the side of the ship?
0:13:16 > 0:13:19As you can see, over here, we've got the ship's mooring winches,
0:13:19 > 0:13:22we've got a davit and it goes over the side, on a 10mm steel wire rope.
0:13:22 > 0:13:26OK, so basically, it's chucked over the edge on a big string.
0:13:26 > 0:13:29- That's right. - And how does it actually work?
0:13:29 > 0:13:32We've got water and plankton coming through this aperture at the front.
0:13:32 > 0:13:35It gets trapped on a band of silk, another piece of silk goes
0:13:35 > 0:13:38over the top and, effectively, we get a plankton sandwich.
0:13:38 > 0:13:40The crew will tell us where it's gone into the water,
0:13:40 > 0:13:43where it's come out of the water,
0:13:43 > 0:13:46and then we can assign that segment of silk to that part
0:13:46 > 0:13:50of the ocean and then the scientists can start doing their stuff.
0:13:50 > 0:13:55In the lab, every silk is logged, as to when and where it came from.
0:13:55 > 0:14:00Then, it's painstakingly analysed and the results are very revealing.
0:14:00 > 0:14:03The sea's warming up, global warming,
0:14:03 > 0:14:06and what that is doing is it's shifting
0:14:06 > 0:14:10the distributions of the plankton, so for instance, the colder
0:14:10 > 0:14:12water species is much richer in fat,
0:14:12 > 0:14:15therefore a much better food source, and they're moving north,
0:14:15 > 0:14:19out of the North Sea, to be replaced by a copepod that actually isn't
0:14:19 > 0:14:22such good food and that will have a big impact on such
0:14:22 > 0:14:24things as basking sharks.
0:14:24 > 0:14:27It seems that one of the possible reasons
0:14:27 > 0:14:30we could be seeing less of the huge basking sharks
0:14:30 > 0:14:35around our shores is the lack of the right tiny stuff around our shores.
0:14:37 > 0:14:40Climate change appears to be altering
0:14:40 > 0:14:43the plankton around our coast.
0:14:43 > 0:14:47And that, I hope, Hugh, goes some way to answering your question.
0:14:49 > 0:14:50Now, this over here is Gunna Sound,
0:14:50 > 0:14:53one of the basking shark hot spots of the UK.
0:14:53 > 0:14:56Anything out there right now, Lindsey?
0:14:56 > 0:14:58No luck so far, Hugh, but I do live in hope.
0:14:58 > 0:15:01Actually, speaking of extraordinary sightings,
0:15:01 > 0:15:04back in July this year, a member of the public took some amazing
0:15:04 > 0:15:09footage of sharks just off from RSPB Medmerry in West Sussex.
0:15:09 > 0:15:11Take a look at this footage.
0:15:15 > 0:15:18The RSPB officer who filmed this video said there
0:15:18 > 0:15:23were around 50 smoothhound sharks in this one little spot.
0:15:23 > 0:15:28Each shark measures up to 1.5 metres in length, so it's understandable
0:15:28 > 0:15:32that the people watching were pretty surprised to see them.
0:15:32 > 0:15:36Experts think they came in to the shallows to hunt for hermit
0:15:36 > 0:15:38crabs and other marine life.
0:15:38 > 0:15:43But after three days, they vanished as quickly as they arrived.
0:15:43 > 0:15:45A real mystery.
0:15:45 > 0:15:49And it isn't the first time sharks have come close to shore.
0:15:49 > 0:15:53This is a blue shark filmed in Pembrokeshire.
0:15:53 > 0:15:57The Shark Trust have said this behaviour is very strange.
0:15:57 > 0:16:00Most likely, it was a very young shark that had mistakenly
0:16:00 > 0:16:02swum into the shallow waters.
0:16:02 > 0:16:05But don't be scared.
0:16:05 > 0:16:08There have only been two unprovoked shark attacks in England
0:16:08 > 0:16:12since 1847, neither of which proved fatal.
0:16:12 > 0:16:15The common skate or flapper skate is a species that's particularly
0:16:15 > 0:16:17struggling.
0:16:17 > 0:16:20The One Show's Mike Dilger went to find out how they're being
0:16:20 > 0:16:22protected.
0:16:22 > 0:16:25The Sound of Jura on the west coast of Scotland is home to
0:16:25 > 0:16:29one of our largest and rarely filmed fish.
0:16:29 > 0:16:30Today, I'm joining sea angler
0:16:30 > 0:16:32Ian Bowart, who is hopefully going
0:16:32 > 0:16:34to help me catch more than just
0:16:34 > 0:16:35a glimpse of one.
0:16:35 > 0:16:39Ian is part of the conservation effort for the enormous common
0:16:39 > 0:16:43skate, which sadly today is anything but common.
0:16:43 > 0:16:46That's about a 180 pound fish going back.
0:16:46 > 0:16:48They're massive! Look at the size of that!
0:16:48 > 0:16:51They're actually classed as critically endangered.
0:16:51 > 0:16:54They're on the same list as Siberian tigers and polar bears.
0:16:54 > 0:16:57Eight years ago, Ian established the Scottish Sea Angling
0:16:57 > 0:17:01Conservation Network to protect vulnerable skate and shark species.
0:17:03 > 0:17:06Skate are bottom dwelling fish, closely related to sharks,
0:17:06 > 0:17:10so hauling one up from the depths is going to be tough.
0:17:10 > 0:17:13- 30 minutes later... - Got something here, mate.
0:17:14 > 0:17:16- Get the harness.- OK.
0:17:16 > 0:17:20And now I need to bring it up through 450ft of water.
0:17:20 > 0:17:22Argh!
0:17:22 > 0:17:25- That's it.- God! Quite a pull on it!
0:17:25 > 0:17:27This fish isn't going to go up in 30 seconds.
0:17:27 > 0:17:28You could be here 40 minutes.
0:17:28 > 0:17:32I'm seriously overheating. I'll have to take my hat off.
0:17:32 > 0:17:35It's hard but vital work, as Ian's tagging programme is
0:17:35 > 0:17:38unravelling the mysteries of the skates' life.
0:17:38 > 0:17:40The remarkable thing is the tags have shown the fish
0:17:40 > 0:17:42don't go very far.
0:17:42 > 0:17:46In fact, 66% of the fish we've tagged have been recaptured
0:17:46 > 0:17:49within five miles of the original capture site.
0:17:49 > 0:17:52Ian hopes his work will lead to the Sound being granted
0:17:52 > 0:17:53Marine Protected Area status,
0:17:53 > 0:17:57as it's so crucial to the skate's survival.
0:17:57 > 0:18:00And after the hard work reeling,
0:18:00 > 0:18:04I finally get my first glimpse of this amazing fish.
0:18:04 > 0:18:05It's coming, it's coming!
0:18:05 > 0:18:07It's coming! It's flippin' huge!
0:18:07 > 0:18:11- Ha-ha! Wow! Look at that! - Come in behind me.
0:18:11 > 0:18:14Oh, my word! I've just caught myself
0:18:14 > 0:18:17an absolutely enormous skate.
0:18:17 > 0:18:20What a beautiful animal! Look at that!
0:18:20 > 0:18:22Oh, my word!
0:18:22 > 0:18:26In order to get the skate on board and tag it, we need to use hooks.
0:18:26 > 0:18:28It might look uncomfortable,
0:18:28 > 0:18:31but Ian's work has shown there's no lasting damage done
0:18:31 > 0:18:35and the data gained of course is incredibly valuable.
0:18:35 > 0:18:37Wow! Look at that!
0:18:37 > 0:18:39That is amazing!
0:18:39 > 0:18:44I can't believe that this fish exists in British waters.
0:18:44 > 0:18:48We need to minimise the time the skate is out of the water,
0:18:48 > 0:18:51so first task is to harmlessly tag it with a unique code attached
0:18:51 > 0:18:53to its giant wing.
0:18:53 > 0:18:59Check out the wingspan of this. It is a fish I'm talking about, not a bird.
0:18:59 > 0:19:01What a specimen!
0:19:01 > 0:19:05But we need precise measurements for the scientific records.
0:19:05 > 0:19:09- 53 inches by 80 inches.- Yes. - Is that a big size? - It's a good fish.
0:19:09 > 0:19:13And that equates to a 12 stone fish, the weight of a fully-grown man.
0:19:13 > 0:19:15We've got the tags in, we've got the measurements,
0:19:15 > 0:19:17so a kiss and a cuddle and put it back.
0:19:17 > 0:19:19- Job done.- Yeah.
0:19:19 > 0:19:23But with a fish this size, it's a task that's easier said than done.
0:19:23 > 0:19:25Argh! Yes.
0:19:25 > 0:19:28- Ready to go?- Yeah.
0:19:28 > 0:19:31Ha-ha-ha! There it goes!
0:19:31 > 0:19:34- Just flapping off into the deep. - And gone.
0:19:34 > 0:19:37But our job for the day isn't done
0:19:37 > 0:19:41and it's not long before we land another of these incredible fish.
0:19:41 > 0:19:43A smaller one, but it's a male.
0:19:43 > 0:19:47When I say smaller, I still mean very big.
0:19:47 > 0:19:51You can see the row of teeth and it's got a surprisingly large mouth.
0:19:51 > 0:19:54Anything that gets in there, basically, is history.
0:19:54 > 0:19:58They feed on other skate species and crustaceans.
0:19:58 > 0:20:02Males are smaller than females and there's another obvious difference.
0:20:02 > 0:20:08The main difference is the claspers. Now, these actually are the penis.
0:20:08 > 0:20:10A skate, shark, literally has two penises.
0:20:10 > 0:20:12Skate are long-lived animals,
0:20:12 > 0:20:15potentially living up to 100 years of age.
0:20:15 > 0:20:17Any idea how old this might be?
0:20:17 > 0:20:19I would guess, based on the size, about 20 years old.
0:20:19 > 0:20:23So, there's a fair bit of growing in that one yet. It's a young teenager.
0:20:23 > 0:20:26- It's a pretty fine specimen though. - It's a lovely fish.
0:20:26 > 0:20:28- Let's get him back in the water. - Yes.
0:20:28 > 0:20:33To date, Ian has tagged 3,000 individuals and each one returned
0:20:33 > 0:20:36safely increases our understanding of this spectacular skate.
0:20:36 > 0:20:40Ian and his team are playing a massive role in conserving
0:20:40 > 0:20:41this beautiful species.
0:20:41 > 0:20:44Let's hope the skate we've caught today will steadily
0:20:44 > 0:20:48but surely repopulate the seas further afield once more.
0:20:53 > 0:20:54In the Atlantic,
0:20:54 > 0:20:58blue sharks migrate from the eastern seaboard of the United States,
0:20:58 > 0:21:02following the Gulf Stream, and by the summer it's thought that many
0:21:02 > 0:21:05thousands of them are arriving here on the UK coast.
0:21:05 > 0:21:08For a very particular reason,
0:21:08 > 0:21:12I've hankered after seeing blue sharks in the wild for years.
0:21:12 > 0:21:15And in June this summer, reports from fishermen indicated that the
0:21:15 > 0:21:18sharks had started to arrive in Cornwall.
0:21:18 > 0:21:21By the end of July, they were seeing them almost every day.
0:21:21 > 0:21:23So as soon as there was a break in the weather,
0:21:23 > 0:21:26I headed down there myself to see if I could catch up with them.
0:21:34 > 0:21:38If I'm lucky today, I could have one of the most exciting marine
0:21:38 > 0:21:41wildlife encounters that Britain has to offer.
0:21:41 > 0:21:44But there's another reason that I'm really keen to catch up with
0:21:44 > 0:21:46Cornwall's blue sharks today.
0:21:46 > 0:21:51I've actually met them before, under very different circumstances.
0:21:55 > 0:21:59Back in 1974 on holiday in north Cornwall, I was already
0:21:59 > 0:22:02a mad keen fisherman and me and my friend Charlie
0:22:02 > 0:22:05had heard it was possible to go shark fishing.
0:22:06 > 0:22:10And this is the Super 8 footage that my mum took of that trip.
0:22:13 > 0:22:17We did actually catch four sharks that day and I caught one myself.
0:22:17 > 0:22:19Clearly at the time,
0:22:19 > 0:22:22this was about the most exciting thing that could happen.
0:22:22 > 0:22:25But all these years later I really don't feel good about the fact
0:22:25 > 0:22:27that I killed a shark.
0:22:28 > 0:22:31I'm afraid I didn't have a thought for marine conservation back then.
0:22:32 > 0:22:36But today I want to go out there, say hello to the blue sharks of Cornwall
0:22:36 > 0:22:41and make amends for something I did 40 years ago that frankly, I regret.
0:22:43 > 0:22:46I'm joining John Richardson from the Shark Trust
0:22:46 > 0:22:48and heading out of Penzance harbour.
0:22:52 > 0:22:55Fishing for shark does still happen here but attitudes have moved on.
0:22:55 > 0:22:58Since you were fishing as a kid it has changed completely.
0:22:58 > 0:23:01Nowadays it's almost always catch and release.
0:23:01 > 0:23:03Some of them will bring them on to the deck very quickly
0:23:03 > 0:23:06and they might get a photograph and take measurements
0:23:06 > 0:23:09which are really useful information and they will get them
0:23:09 > 0:23:12back in the water as quickly as possible with the minimal impact.
0:23:12 > 0:23:15So does catch and release angling provide a good opportunity for anglers
0:23:15 > 0:23:20to actually collaborate and help scientists and conservationists such as yourself?
0:23:20 > 0:23:23Yes, it certainly does. They can tell us the species, the size, the sex,
0:23:23 > 0:23:26all sorts of really useful information about shark populations.
0:23:30 > 0:23:32Today, we won't be catching sharks.
0:23:32 > 0:23:35I just want to see them in their natural environment.
0:23:38 > 0:23:41Blue sharks are found in the deep, open ocean
0:23:41 > 0:23:43so we are heading ten miles offshore.
0:23:47 > 0:23:49Skipper Charles Hood is taking me
0:23:49 > 0:23:51to what seems like the middle of nowhere.
0:23:54 > 0:23:58What I've done over the years is come back to the places we have been seeing them
0:23:58 > 0:24:02and for some reason, maybe it is where the currents meet or where the tides meet,
0:24:02 > 0:24:05this is a good spot where we regularly see them.
0:24:05 > 0:24:08To encourage the sharks to come to us, we are
0:24:08 > 0:24:11chumming the water with minced up dead fish.
0:24:11 > 0:24:14Following Shark Trust advice we are not actually feeding them,
0:24:14 > 0:24:17simply laying a scent trail to attract them.
0:24:18 > 0:24:20And if we do see them, we should be in for a treat.
0:24:22 > 0:24:24Living up to 20 years,
0:24:24 > 0:24:27blue sharks can reach almost four metres in length.
0:24:27 > 0:24:28As the name suggests,
0:24:28 > 0:24:31they have a distinct metallic blue across their backs.
0:24:34 > 0:24:38The underside is actually pure white. This is for camouflage.
0:24:39 > 0:24:43That feature does not protect them from their biggest predator.
0:24:43 > 0:24:44Us.
0:24:46 > 0:24:49Globally, they are one of the most widespread sharks on the planet,
0:24:49 > 0:24:52but they are also one of the most heavily fished.
0:24:52 > 0:24:55So they're being caught around the world for their fins and for their meat.
0:24:55 > 0:24:58And what is the impact of this fishing on the blue shark population?
0:24:58 > 0:25:02Recent research suggests that the Atlantic blue shark population alone
0:25:02 > 0:25:05has decreased by 30% in the last three decades.
0:25:05 > 0:25:07That is due to commercial fishing
0:25:07 > 0:25:10and also the fact that there is no catch limits at all.
0:25:10 > 0:25:13We know that they are out there somewhere
0:25:13 > 0:25:16but catching sight of one on a trip like this is never a given.
0:25:17 > 0:25:20Maybe the sharks remember me from all those years ago
0:25:20 > 0:25:22because today they are staying well clear.
0:25:22 > 0:25:26When you're constantly staring at the ocean waiting for something to happen,
0:25:26 > 0:25:29waiting for a little shark fin to appear,
0:25:29 > 0:25:32your mind can start playing tricks on you
0:25:32 > 0:25:35and you start seeing those shark fins popping up all over the place.
0:25:43 > 0:25:46And then, finally, after four and a half hours...
0:25:46 > 0:25:47There it is.
0:25:47 > 0:25:50..we get our first glimpse.
0:25:50 > 0:25:52That was definitely a blue shark.
0:25:52 > 0:25:54It was definitely a shark, wasn't it?
0:25:54 > 0:25:57And with a shark in the vicinity, we get kitted up.
0:25:59 > 0:26:02Before I have a chance to get in the water, the shark comes back.
0:26:02 > 0:26:05But at least I'm ready with my underwater camera.
0:26:10 > 0:26:12She's right here.
0:26:16 > 0:26:18She's coming in again.
0:26:20 > 0:26:23And then, after a sniff of mackerel, she disappears.
0:26:25 > 0:26:28I enter the water hoping she will return.
0:26:29 > 0:26:32But it seems she's had enough of us for today
0:26:32 > 0:26:35and my hope of swimming with her is dashed.
0:26:36 > 0:26:40Well, it has been about half an hour since we last saw her
0:26:40 > 0:26:43and I think maybe that's it for today and she's headed off.
0:26:44 > 0:26:46But I did see her.
0:26:46 > 0:26:50She came really close to the boat and it really was very exciting.
0:26:51 > 0:26:56I can't change what I did 40 years ago but I hope that now fishing
0:26:56 > 0:27:00practices have changed, sharks have a brighter future here in the UK.
0:27:01 > 0:27:05It was breathtaking to see one, this time where it should be.
0:27:06 > 0:27:08She's right here.
0:27:09 > 0:27:12Sharks belong out in the wild.
0:27:12 > 0:27:14And very much alive.
0:27:18 > 0:27:20Now, perhaps at the beginning of this programme
0:27:20 > 0:27:22you were just a little bit wary of sharks.
0:27:22 > 0:27:24Maybe more than a little bit wary.
0:27:24 > 0:27:27Maybe you were outright terrified.
0:27:27 > 0:27:29Well, I hope we have managed to convince you to love
0:27:29 > 0:27:33and not fear this amazingly versatile group of fishes.
0:27:33 > 0:27:37They play a key role in maintaining the balance of our oceans,
0:27:37 > 0:27:40not just here in the UK but all over the world.
0:27:40 > 0:27:44That is all we've got time for today but we will be back tomorrow
0:27:44 > 0:27:48with another dip into our extraordinary marine scene here in the UK
0:27:48 > 0:27:51and we will be taking a closer look at the diverse sea birds
0:27:51 > 0:27:54that fly and live around our shores.
0:27:54 > 0:27:57I'll be holding in my hands a baby puffin,
0:27:57 > 0:28:00which in case you didn't know is called a puffling.
0:28:00 > 0:28:01How cute is that?
0:28:03 > 0:28:06And I'll be scrambling up a rock face to try and place
0:28:06 > 0:28:09a tracking device on one of our most superb seabirds, the gannet.
0:28:12 > 0:28:13That's all for now.
0:28:13 > 0:28:16Meanwhile, we will leave you with some fantastic sharks.