Original subtitles

The oceans are places of wonder.

Blue Planet II showed us

the beauty and extraordinary behaviour of marine life

whilst highlighting how fragile and threatened our seas have become.

Now, as Blue Planet Live carries out a health check

on the world's oceans,

we are staying closer to home.

Our British seas are rich, varied and key to our island heritage -

but how are our lifestyles affecting them?

Whoa!

We'll meet the unsung heroes

dedicated to protecting our waters

and the wildlife that relies on them...

If we don't look after nature, nobody else will.

..and celebrate the scientists

striving for solutions to the challenges.

Whoa...

Plus we'll meet the crabs with a flair for style...

They're dressing up as seaweed as a means of camouflage. Yes.

..and delve into our very own deep sea coral reefs.

This is the most important deep sea coral, I think, in the whole world -

and this is just off Scotland.

So, dip into our UK waters

and see them like you've never seen them before.

BOTH: Welcome to Blue Planet UK.

Hello, I'm Gillian Burke,

and I'm a biologist with a passion for all things marine.

I love exploring what lives out there in the ocean.

And I'm Steve Brown.

I've grown up on the coast

and I loved learning about our relationship with it,

from a kid collecting fossils and shells,

to now learning that what we wear makes a difference to the fish.

So, where are we today?

Well, we've come to the beautiful fishing village of St Abbs

on the south-east coast of Scotland.

Now, St Abbs is famous for all sorts of things -

it's famous for access to beautiful, amazing dive sites

just off the coast -

but, Steve, did you know it's also the unofficial capital

for one of the world's ugliest fish?

Well, I didn't know this at all.

What sort of fish are we talking about?

Well, it's one of my favourites - it's a wolf fish.

I mean, they are incredible.

They have rows of teeth, the front teeth are sharp, conical teeth,

and then behind that there's rows upon rows of these grinding molars

that they use to crush sea urchins and shellfish.

I think they're pretty cool.

Most fish are pretty cool, but that one itself, pretty ugly.

I mean, look at it, there.

It looks like a big overgrown eel.

As much as I love what's going on down there,

I'm just as interested in what's above the waterline.

Looking out on the cliffs, as a keen birder, I like looking out.

I can see just behind us, here, there is

a cormorant finishing up its fishing for the morning -

and what a place to be, eh? It is.

It's an absolutely stunning day -

so, let's see what else is coming up on today's show.

We make a big splash as Chris Packham meets an author

who is passionate about us all connecting to our British waters.

There's a mammal in the sea -

but it's not a dolphin or a whale, it's a man.

OK, go!

We fly high behind the scenes on Blue Planet Live

when they're looking for whales.

Flat, calm water.

Really makes for lovely shots.

I join in with some traditional fishing off the Cornish coast...

That's my first haul.

..and there's an unexpected catch.

The size of this is absolutely phenomenal.

And we uncover some of the secrets hiding around our British coastline.

Now, you'd have to be pretty unaware

to not to notice that our attitude towards single-use plastics

has changed loads over the years.

From being the answer to almost everything,

it's now the problem that won't go away. Quite literally.

It certainly is - and on Blue Planet II we highlighted,

a few times, the catastrophe facing our marine life,

and unfortunately, sadly, down to us.

DAVID ATTENBOROUGH: Just over 100 years ago,

we invented a wonderful new material

that could be moulded into all kinds of shapes,

and we took great trouble to ensure

that it was hard-wearing, rot proof and virtually indestructible.

Now, every year, we dump around 8 million tonnes of it into the sea.

Now, those images are powerful - but since they were shown,

I'm pleased to report that plastics

have become a national political talking point.

Here on Blue Planet UK,

we're looking at the many inspirational stories

of people who are making a difference.

Absolutely - and, to do just that, I went down to Devon recently.

When synthetic fishing nets reach the end of their working lives,

they're often lost or, even worse, discarded out to sea.

The problem is, the plastics in them don't break down,

and they cause biological booby traps known as ghost nets.

They hang in wait - sometimes almost invisible,

other times, mimicking vegetation -

but always a hazard for sea life.

Recreational diver Rob Thompson

has been getting up close and personal

to British wildlife for years...

..but he is continuously astounded

by the devastation that most nets can cause.

They float in the open ocean snaring or snagging on wrecks and reefs,

killing marine life in its millions.

Enough was enough for Rob.

A few years ago,

he pledged to retrieve as many of the death traps as he could.

Nowadays, when he is not collecting plastic underwater, he's on it.

Rob uses a kayak to access plastic in those nooks and crannies

which characterise our coastline,

and, remarkably, his kayak itself is made from recycled plastic -

and a key ingredient is ghost netting.

So, Rob, ghost nets - how long can they last?

Here's one example of how long they can potentially last.

This is a ghost net which went down

with the wreck of the Conqueror in 1977.

So, it had been in the water for 40 years.

It was a wreck just outside of Mousehole down in Penzance,

and it's got the full brunt of the elements,

through all of the winter storms every year,

and that has completely demolished the wreck.

The wreck, now, is unrecognisable as a shipwreck.

It's literally just plates on the seabed,

and yet, the net, still completely recognisable, completely strong.

It's designed to catch, it's designed to be very strong,

to entangle things and not to be forgiving.

In Cornwall, especially, we have lots of grey seals,

and they're regularly found entangled in nets,

because seals are naturally inquisitive.

They're a bit like dogs, really, they want to interact,

they want to play with things... Yeah.

..and they see a net drifting round,

it's just another thing to interact with.

You see quite a lot of crustaceans sort of tangled up,

but what you find is that as marine life goes into it,

gets tangled, it then almost baits that trap again... Yeah!

..and then more stuff comes in to feed on it,

and that whole cycle continues.

Is he still alive? Yeah. Yeah. There's a lot of live ones.

Rob started with a small team of people to retrieve ghost nets

and help trapped animals...

..but just organising clean-ups wasn't enough.

He was looking for the next step -

harnessing the positive potential of these super-strong nets.

You've got a resource, there,

very high-grade material that can be reused and repurposed.

For me, the eureka moment was that black bag photo at the end,

where you've got all your black bags lined up,

and the kayak was physically sat there next to it,

and I thought, that's it, that's what I want to do,

actually make the kayaks out of the plastic we're gathering,

and then that could be used to go back out on the water

and recover more marine plastics.

Rob sends his recovered plastics to a company in Denmark,

where they process it into pellets

and send them back to a factory in Somerset.

Here, Paul Robertson oversees the process

of turning the pellets into Rob's kayaks.

He'd had an idea, he'd seen it through,

followed a process and come up with the finished goods,

and he called me up and says, "Do you want to test it?"

and it was like, "Er, let me think for a second. Yes."

It's a bit like baking a cake.

With a mould, get it into the oven...

..just about 300 degrees Celsius,

cooks for about 40 minutes,

cool it down steadily,

out comes a finished, solid kayak,

which we then check over and add some fittings,

some seats and bits and pieces,

and pretty much goes out on the water, and people paddle it.

It seems simple,

but developing the right formula took Rob months to perfect.

Back in Plymouth, I'm going to put one to the test.

Argh!

And we're in.

Whoa!

We're setting off from the Mountbatten Centre on the docks,

which is surrounded by areas of natural beauty -

but also heavily populated,

sadly making it the perfect place to hunt for plastic.

So, what do I do if I see any plastic?

Just literally try and get hold of it and hoick it into your boat.

Eat my wake.

I can't believe you call this a job!

Whoa!

It's been a long time since I've been on the water like this,

and although we're paddling for plastic,

it's not a bad way to spend the day.

Enjoyment aside, it doesn't take us long to find a man-made mess.

Lots of different types of plastic

that's washed up along the breakwater,

from rubber tyres to bits of rope...

Looks like there's some kind of traffic cone over there, as well.

Yeah, there is a traffic cone up there!

But it's funny, isn't it, because on first glance,

you can see the tide line, because of the wood in it,

but it doesn't take much to start spotting the different colours

of the rubbish amongst it. It doesn't.

You could easily be working in one of the buildings above

and have no idea of the rubbish lodged into the rocks below -

which is why the kayaks provide such a unique viewpoint.

Well, there's more than you think, isn't there?

It is absolutely strewn along here.

How many canoes have you got up there, do you reckon? A couple!

I can't believe how much plastic Rob has retrieved.

Including traffic cones.

So, that was maybe 10 square metres in five minutes... Yeah.

..and you've got a kayak full of it.

That illustrates how it doesn't really

have to eat into your day that much. Couple of minutes' work.

Yeah, it's good fun, scrabbling around rocks.

Who could object to doing that?

And do some good.

It's about going out kayaking, and whilst you're there,

pick up some rubbish, if you see it.

Yeah, definitely - and it didn't seem like so much of a chore,

and if everyone did that

during their normal recreational activities,

they'd have a fantastic cumulative effect.

Now, that is inspiring - and incredible to think

that all this plastic waste turns into a kayak

that you can use to go out there and collect more plastic waste.

I think that's brilliant.

Now, joining me today is Calum Duncan

from the Marine Conservation Society.

Calum, tell me, the Blue Planet effect -

have you, as a marine conservationist,

noticed a big change since Blue Planet II came out?

Absolutely.

We've been running our Great British Beach Clean for 25 years now,

but last year was the biggest ever event that we've had.

We had the biggest ever in Scotland, we had 135 beaches,

many thousands of people taking part.

More and more people just want to get engaged,

they want to do their bit, they want to help stop this plastic tide,

so we are very grateful for the awareness

that this programme has brought.

Now, beach cleaners are a great way for people to get involved,

to help to make a difference.

What other work, though,

what other things are MCS doing to get people involved?

Were also asking people to report sightings of wildlife

such as basking sharks, turtles and jellyfish, which everybody can do.

For those who dive, we've also got a project could Seasearch,

and we've been very active here at St Abbs over the years,

and we've also been making films to celebrate the connections

the people living round the sea have with the sea.

Everybody is connected to the sea,

every second breath we take includes oxygen from the ocean.

It's all about celebrating what an amazing resource

and fantastic environment the ocean is.

Well, that's incredible, and I believe this film -

some of it, at least - has been filmed right here.

So, let's take a look.

I believe in that lifelong learning, keep learning, keep the brain going,

and whenever you go diving, you see something different.

Every time, you know, all the years I've been diving,

I still see things that I haven't seen before.

You never know what's going to come up.

You know, the last couple of years, we've been seeing pods of dolphins

along the coast here, which is beautiful.

You never know if you're going to see them or not,

so it's a little bit of anticipation of what excitement there might be.

Calum, you've been doing this work, marine conservation work,

for almost two decades.

How do you feel, now,

about marine conservation and the future of marine life here?

There's been a huge increase in awareness,

there's been an increase in people getting involved,

being part of the solution, so, everybody's getting more aware,

and we need to take that awareness and change it into action,

and that's where the people who are getting

involved in our projects, they're the ones showing leadership

through our beach projects, through wildlife sightings,

through diving, but what we need now is real leadership

from government and industry

to match that ambition shown by the people.

I couldn't agree more with that. Thank you so much. Steve.

Some whales and dolphins can be seen here

off the coast in St Abbs, but an absolute hot spot for them

this time of year is Baja California in Mexico, where Chris Packham

is reporting for Blue Planet Live all this week -

and everyone that knows Chris

knows how passionate he is about British wildlife,

so, before he left, he spent some time down on the south coast,

where he lives, with some people

that want to champion our British seas.

Oh, goodness me.

Oh, my goodness.

There's a mammal in the sea -

but it's not a dolphin or a whale, it's a man.

Philip Hoare.

He is an author, and he is passionate about animals

that should be in the sea on a freezing cold day like this.

Those whales and dolphins.

Thank you! It's a real pleasure to meet you. And you!

But before your metabolism shuts down, let's get out of here

and into that warm cafe.

Fantastic! Quick, get dry. Philip, get dry.

Philip's love of the sea

is beautifully described in his writing.

Philip, two questions that I have to ask you immediately

whilst you're supping your warm tea is, firstly, why do you do that,

and secondly, metabolically, how do you do that?

Why I do it - I think I'm making up for lost time.

I grew up in Southampton, like you,

but I had this absolute deep-seated fear of the sea.

I mean, it just scared me so deeply.

I didn't learn to swim until I was 29.

I was living in the East End of Hackney

and I realise that I just felt really inept

in my relationship to the...

..you know, that great big thing, the biggest thing on our planet.

I mean, that is the wild world,

and just by one step you could be somewhere which is completely wild -

and I think that is one of the reasons why I love swimming.

You don't like calling it wild swimming.

No. Why is that?

Because I think that's a very middle class, commodified...

You know, "We've suddenly discovered swimming."

I do it, very often, in the dark -

I did it this morning, actually, at 2am, in the dark. 2am?

Yeah. You went into the sea... Yeah. ..at 2am? Yeah.

It's a strange compulsion, isn't it? Do you feel better for it?

I absolutely do. Actually... Physically? I absolutely do -

and, for me, that's the great sort of thing about the water,

is that, briefly, I can be like a whale, or a dolphin.

Is difficult to say, Philip, that anyone animal, organism,

is more important than any others,

but whales are important for so many reasons -

the things you've written about.

Yeah, because they are us. They are very like us.

The social structure, the communication.

In your book here, Leviathan, you've said,

"It's becoming clear that whales and dolphins

"have brains matched only by the higher primates and humans,

"with whom they share the same convoluted neocortex

"part of the brain, the characteristic wrinkles and whirls

"on that top layer of the organ,

"and which indicate exceptional intelligence.

"Studies show that cetaceans can solve problems, use tools,

"exhibit joy and grief, live in complex societies -

"but, not only that, they pass on these abilities

"in cultural transmission."

There is another couple of things I'd like to quote from your book.

This is the thing, I marked this page when I read it,

because it was terrifying to me.

You were talking about the hunting of sperm whales,

and you write here that between 1964 and '74,

they managed to kill a quarter of a million animals.

"It was as if, in advance of the end they knew that must come,

"they exerted themselves all the more in the effort."

That was going on in our lifetime!

That's right - and there were ships coming up from the South Atlantic

laden with whale fat, which became margarine.

You and I probably ate margarine with whale blubber in it.

Um...

You know, your mother... It's astonishing, isn't it?

Yeah, no, it's astonishing - but we stopped killing them in 1983.

Generally, most people stopped killing great whales.

That's an amazing thing that we human beings did.

In order to, you know, continue that,

so that people can cherish not just whales

but everything else that lives in the ocean,

and the oceans themselves, we've got to connect people to it.

How do we do it?

I think, you know, physically, you go back to it, you know?

You go swimming, you mean?

I would say so. You're trying to get me...

You're trying to get me in... You need to get in there, Chris!

Get your kit off.

Into the water.

Let that big, white, surging, monstrous animal

engulf you in its embrace.

I'm not sure.

There's nothing wrong with British waters - I love the colour,

the colour's amazing, it's just... it's just the temperature.

I don't blame you.

If you've been inspired to take a plunge in the sea,

then please do visit our website for advice on how to swim safely.

You know, it's so true that although this is an island nation,

so many of us don't feel connected to the sea.

No, there's a lot of us that have got no connection at all.

Now, whilst Chris is abroad reporting for Blue Planet Live,

we've been given access to some extraordinary

behind-the-scenes footage.

You might remember during Blue Planet II there was a moment

when the team managed to get a camera onto a sperm whale.

DAVID ATTENBOROUGH: Sperm whales don't wait for their prey

to rise to the surface,

they swim down into the depths to find it.

The calf sticks to its mother as closely as it can...

..touching her frequently...

..as if for reassurance.

The Blue Planet Live team returned to film those sperm whales,

and one of the shots they wanted to get

was to show the size of the sperm whale in relation to the boat.

This is what happened.

So, I am just preparing my drone to fly over the water here.

The drones really have become a completely essential

part of the film-making experience now, particularly of marine mammals

that spend only a portion of their time at the surface.

To be able to get them at the surface from above them

is an amazing vantage point.

The team are attempting to film sperm whales,

which spend most of their time underwater...

..but briefly surface to breathe.

To have any chance of getting the shot,

the drone needs to be in the air, waiting.

OK, go!

OK, where are they?

Launching from the water is making me a bit more nervous,

because obviously Mark is fantastic, kind of, like, guiding

the drone into your hands and stuff,

but if one wave moves or something like that, and something knocks,

then you could end up hitting the drone, or else just not catching it.

It's a real risk to losing it altogether,

and it's not like we're recording footage directly from the drone

onto something else - if that drone goes down,

everything that we've shot on that card goes with it.

So, it's a lot of tension.

The whales break the surface.

The whale's gone.

So, first attempt at trying to get a two shot

of a sperm whale at the surface and our boat was half successful.

I was able to get in position,

but the horizon on the drone was a bit out,

so I just had to adjust for that, and by the time that had finished,

then the whale had just got the last of its dive.

But I think it's just a shallow dive,

so it should actually be at the surface again

in the not-too-distant future.

The team are in luck.

OK, so, they did indeed go for a shallow dive,

and it's basically a family of sperm whales at the surface,

two adults and a calf, and Shane's boat, that I'm filming,

is following them - at a nice safe distance, of course.

So, I'm just trying to get ahead

and get some nice shots of them at the surface.

Oh, it's so wonderful to see these whales.

They haven't been seen for a couple of days,

So, really glad that they're back with us today,

and the conditions are wonderful. Really flat, calm water.

Really makes for lovely shots.

One of the reasons we want to get a two shot of the whale and the boat

is just to show the scale of them. They are huge animals.

I'm just trying to make the most of it.

This might be our only opportunity.

A low battery warning has just popped up on my drone,

so, even though I got really excited

that I've captured all this lovely footage,

it's going to mean nothing if I don't get this drawn back,

so, yeah, going to have to really concentrate now

and just make sure we get a safe landing

and bring this drone and the car at home.

It's a nail-biting moment, but the retrieval of the drone as a success.

Phew!

Well done.

High five. Always... Squeaky bum time. Always a relief.

Well done. Oh, my God.

OK, great. That's excellent.

Just as we were running out of time,

pretty much the last chance we had before this boat's got to go,

and the last of the drone batteries, we got our shot.

What an amazing shot that was - that really paid off.

We have a drone up there, too...

..and a lifeboat heading out -

and that's what drones are really useful for.

You get these incredible shots, incredible perspective,

as we're doing this morning over here,

but they're not just useful for filming.

They're useful for science and research,

as Mike Dilger found out when he went to West Wales for The One Show.

I've come to Cardigan Bay to look for the UK's most sociable animals -

but to find them, I'm going to have to head out there,

because I'm after bottlenose dolphins.

Katrin Lohrengel from the Sea Watch Foundation

has been studying these dolphins for three years.

Until recently, dolphin behaviour

could only be observed from the boat -

but now drone technology is giving a fresh perspective.

By getting aerial shots of the dolphins

we can get a bit more information

on how they're interacting with each other.

We can see better with the drone, really,

because we have a better view of them.

It can approach them quite closely

without causing a lot of disturbance.

Also, if we see them from above,

often you can see deeper into the water,

so you're able to get a definite count of the animals.

So, it's an exciting time, being a researcher on dolphins.

Yes, definitely.

Drones surveying of marine mammals is still in its infancy in the UK,

and can only be conducted

by certified researchers with a licence.

And what they find will help us understand

how and why dolphins socialise - but first, we need to find some.

At this time of year,

bottlenose dolphin numbers are at their peak in the bay,

and Katrin is taking us to some known hot spots.

It isn't long before we glimpse some in the distance.

Ohh!

Lovely hook fin, beautiful black-grey back -

that's a bottlenose.

Due to the extra blubber needed to keep warm in UK seas,

these dolphins are some of the largest in the world,

reaching an impressive 4m in length.

Bottlenose dolphin.

Oh-ho-ho!

That was probably 2m, leaping out of the water.

Brilliant.

With the survey complete, it's time for us to look at the footage.

Really clear shots of dolphins... Yeah. ..from above, into the water.

Yeah, it really shows that the views that we get from above

can be a lot clearer than what we would see sort of from eye level.

Traditionally, researchers assumed that dolphins

hung out in family groups,

but the drones show that isn't always the case.

What we think is happening here in Cardigan Bay at the moment

is that we have mainly females spending time together.

So, females and calves, and then males and males,

so animals of the same gender and age tend to stick together,

and particularly females with calves will hang out together,

because they often babysit each other's calves for each other.

Look at this, here!

I mean, these dolphins are touching, they're quite close together. Yeah.

What's going on?

So, this is probably a slightly sexual interaction.

So, we have one of the dolphins coming up underneath the other one,

and sort of nudging the other animal's belly...

So, a male, an over-amorous male with a female?

Not necessarily female, to be honest.

They do interact with members of the same sex that way, as well,

particularly males.

The tend to touch each other a lot with their pectoral fins, and...

Quite tactile. Yeah, they're very tactile when they're socialising.

Today's drone survey has shown two dolphins

that Katrin's very familiar with in a completely new light.

We've not, that I know of, seen them together in a group before,

so that's quite interesting.

Start of something exciting. Yes, definitely.

The drone is also important

in assessing the health of individual dolphins.

Using the footage, they can accurately measure

whether they're healthy, or indeed pregnant, without disturbing them.

We are only just scratching the surface

in terms of our understanding of these mercurial animals -

but hopefully the drone research is a game changer

and is going to grant us brand-new insights

into the complex social lives of these dolphins.

Technology really is helping us understand our marine biology,

and even here, we've got it today in St Abbs.

Mario, what is that piece of kit you've got there?

Yeah, this is a 360 underwater camera.

We've got three cameras, so when you take this underwater,

you will be able to see every single direction,

and because St Abbs is such an incredible place to dive,

we want to take this out there

and show people the amazing marine life you can see out there.

Well, talking of amazing marine life,

what we do have is some footage

of some of the stuff that is just out here behind us.

Now, this, here, is an anemone.

It's really hard to tell what it is,

but as it spits the starfish out - it was obviously not to its taste -

you can see that's a dahlia anemone...

..and there's other creatures. I mean, it really is a busy seabed.

This is carpeted with brittle stars -

but check this, they get out of the way,

because that is a predatory starfish.

This is an extraordinary footage - and that's the kind of thing

you're trying to capture with that, isn't it? Yeah, exactly.

We are going to take this through all the best dive sites around here,

so, through tunnels into sea caves,

and really try to capture some of the amazing life around here.

And I suppose it is about making it accessible to everybody.

Yeah, exactly.

That is one of our key goals at the voluntary marine reserve.

It's going to be accessible on the virtual reality headsets,

so even if you don't want to dive, you're too scared to drive,

you think you're too old, you'll be able to go diving out here, as well.

And at home with a cup of tea. Exactly, yeah. Oh, can you imagine?

A whole world opening up - and that's life on the seabed,

and there's another creature that makes its home in the seabed,

but its numbers have not been so prevalent lately,

and that is oysters.

George McGavin from The One Show has gone out to find how whisky...

Whisky?! Yes, whisky - is giving it a boost.

The Dornoch Firth on the north-east coast of Scotland.

It's something of a hidden gem -

a place of outstanding natural beauty.

And a sanctuary for rare wildlife.

But there is an animal that's missing...

..a vital part of this precious habitat,

that vanished over 100 years ago.

Bill Sanderson from Edinburgh's Heriot-Watt University

has a fascination with this missing creature.

Now, the first thing that is really obvious here

is that we've got lots of these.

What have we got here?

Yeah, these are the European flat oysters. How old do you think it is?

Well, it's impossible to tell, really, but I have got one here -

this one came from the Dornoch Firth, we've carbon dated this.

This is 6,000 years old.

Wow. So, they've been here for a very long time.

Oysters were once so abundant in UK waters

that they were considered a cheap fast food -

but with the rise of industrial fishing in the late 1800s,

Britain's vast oyster reefs vanished.

Now, Bill has a dream of bringing oysters back to the Dornoch Firth.

I can see the value of trying to put animals back that were once there.

Mm. Is that all there is to it? No.

The thing about oysters is that they create structure on the seabed -

but they're also amazing biofilters.

They suck the water clean of all the particles.

So, they do two things -

they create a habitat where hundreds of other species will live,

but they also improve water quality.

Bill's dream may have remained just that, had it not been for whisky.

Glenmorangie has been distilling on the banks of the Dornoch Firth

for over 150 years.

Dougie Murray is a second-generation whisky craftsman.

My father started here in 1972 and I've been here for 23 years.

And in that time, since your father began, how have things changed?

They've changed a lot.

The distillery's upped production two or three times,

big investments, as well, which has helped the company grow and grow.

But as the distillery has grown,

so has its impact on the Dornoch Firth.

Waste water from the distilling process

is cleaned and then discharged into the estuary -

but it still contains some organic matter.

This promotes the growth of algae, robbing oxygen from the water -

and this is where the oysters come in,

because oysters just love to feast on algae.

Let me show you what I mean.

Here we have two tanks filled with algae-rich water,

like that in the Dornoch Firth.

In this tank, there are 15 European flat oysters,

while in this tank, there are none.

And now, we wait.

Five hours later -

quite remarkable.

One oyster can filter over 200 litres of water a day.

So, imagine what a reef with millions of oysters can do.

With the financial support of the whisky distillery,

it's a big day for Bill.

His team are putting 300 oysters into the firth

in a pioneering experiment.

Height, width and depth. That's right, yeah.

For every single one.

These are pretty special oysters. They are.

Yeah. These are the first ones back in the Dornoch in 100 years.

All this research and effort is now riding on this.

So, Bill, how do you feel? Oh... This is...

I can't stop grinning, actually. Yeah? Yeah, this is brilliant.

If this batch of oysters settles in,

they will be followed by more.

The vision, eventually,

is for several reefs to be established in the estuary.

Well, I really hope the oysters will thrive

here in the Dornoch Firth once again,

bringing even more life to this beautiful and unique estuary.

I think we can all drink to that.

And I can tell you that the number of oysters has grown

since George was down there, which is great news -

but there are still natural native populations

hanging on in there around the country.

One of those is in Cornwall,

so Gillian went down to find out why.

This is Carrick Roads, Cornwall's largest estuary.

This is a part of the world that I now call home,

and it's got an incredibly complex and beautiful

marine and coastal environment.

And a stronghold for the UK's native oyster.

Here on the Fal, mechanised harvesting of the shellfish

has been banned, and more traditional methods are used.

To protect the oyster stocks, you can only fish here under sail,

casting small nets which dredge the seabed

before being hauled aboard and sifted by hand for mature oysters.

It's backbreaking labour,

and only undertaken in the coldest months, from October to March.

There are no fair weather oyster fishermen round here.

I've often watched these old sailing boats

working their way back and forth across the estuary,

but today I get to see what they do up close.

I'm joining the traditional working boat Boy Willie,

and skipper Timmy Vinnicombe is bringing up the first dredging net.

They're much lighter and less destructive

than modern industrial dredgers.

They pass over a lot of the shellfish.

They just tease over the shells, and a few go into the dredge.

A lot stay behind.

They're very inefficient, really.

There's a certain irony that this technique is so inefficient

that it actually is what makes this a sustainable fishery. Absolutely.

Some people come out and say, "You must be crazy doing this," you know?

I can see at least three, four other oyster boats at the moment.

Do you work together,

or do you kind of work to your own patch in the estuary?

We watch each other quite closely,

you'll see someone go back to a little spot several times,

you'll think, "Ah, I wonder if there are some oysters there," you know?

Yeah! You'll nip and have a look,

and sure enough, someone's found some

and tried to keep it a bit secret. Yep.

And how old is this boat?

This boat was built around 1870, I believe,

because she came into the family in 1923,

needed a rebuild then, in 1923... Right! So, it was an old boat then.

The traditional boats are as much a part of the landscape

as they are in Timmy's blood.

He is the fifth generation of his family

to work these waters using these methods.

We've been on the oyster fisheries since around 1880.

Which is a fair old time.

A few hints been passed down through the generations

of what to do and what not to do, and it can be quite helpful.

We're sorting through Timmy's catch to pick out the oysters,

which has to measure up to strict rules.

Those with a diameter of less than 67mm must be thrown back.

Presumably, that's too small. Yeah, it is a bit small.

How about that one?

Yeah... Keeper? Yeah.

This is what this is all about. These are the oysters, here.

They've kind of got a round shape.

Now, this has a concave back and it sits on the seabed like that,

and its lid will open,

and it filters up to, it's thought, 399 pints of sea water a day -

and if you think about thousands of these

doing the same thing every day,

that adds up to an amazing, like, ecosystem service.

Oysters are considered to be ecosystem engineers,

providing the foundations for diverse marine habitats -

even becoming nurseries for other species.

Oh, that is beautiful!

I mean, this is like rock pooling on a massive scale -

the dredging here, in a sense, is sort of sampling the seabed,

sampling the social communities

and animals that live down in these oyster beds,

and over the short time that we've been here,

I've got two bucket-loads of curiosities.

Got an urchin in here - absolutely gorgeous snakelock anemone.

I mean, I would normally, on the beach,

see much smaller relatives of this, a spiny starfish,

but this - the size of this is absolutely phenomenal.

So, if you flip this over, it's a really good chance

just to see the underside of these animals.

The mouth is there, and all along, on each limb,

are covered with hundreds of these feet,

and they all sort of work in unison,

so that it can actually march along the seabed.

It's really beautiful.

This probably tells the story better than anything else.

This is a huge shell, and inside there is a hermit crab

living in the shell, and on the shell is an anemone, as well.

I mean, that's three organisms all rolled up into one.

I think that's pretty cool.

Of course, all of these wonders go back where they belong.

Now, before we head back,

I can't resist having a go at hauling in

the last catch of the day.

Yeah. Keep pulling.

Keep pulling!

This is not one of those jokes

where it just keeps going and keeps going, is it?

So, what's the technique? Get this on? Yeah.

Agh!

See, and lift out there.

Urgh! That's it.

Now press down...

That's it!

That's my first haul.

Well done. Very good.

Very good for a first... Have I got a job, then?

Yes, definitely.

SHE LAUGHS Cleaning up.

Yeah, I made a bit of a mess. Yeah.

You know, what I love about that was the diversity.

You know, it wasn't just oysters down there, was it?

No, you're absolutely right.

We are so lucky with the marine life we have in this country.

Well, that is it for today, but I'd like to thank everyone

and everything that's been part of Blue Planet UK -

not least our marine life

that we are lucky to share this country with.

Don't forget to join us tomorrow,

when will be back in the beautiful St Abbs.

Bye-bye for now. Bye!

Next time on Blue Planet UK,

I delve into the history of a sea bird colony

that is reaching new heights.

Oh, my word!

Coming up!

We learn the importance of surveying our Scottish sea life

in all seasons...

..and Chris finds out about some rather relaxed rays.

They were bending, and it was like, "Do it again.

"Ooh, do it again!"

So, this is ray back massage. This is ray massage.