All language subtitles for BBC Blue Planet UK (2019) - 04 Eng

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 in seaweed

as a means of camouflaging
themselves. Yeah.

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 and welcome to Blue Planet UK

and it really is blue today.

But whatever the weather,
there are some amazing things

to explore in our oceans.

There certainly are and today
I'm pleased to say we're back

in my old stomping ground Kent
or more specifically

the picture-perfect Victorian
seaside resort that's Herne Bay.

Not only is it a place steeped
in history,

the marine life here
is one of the best.

So while the Blue Planet Live team
had been carrying out a health check

on the world's oceans,
we are sticking closer to home

where there are plenty
of incredible stories.

There certainly are and this is
what's coming up today -

how spiny dogfish
have taken a battering

because of our love for
fish and chips.

Who would have thought

that underneath that lovely crispy
batter could be a kind of shark?

I discover how British science
may offer a lifeline

to Australia's Great Barrier Reef.

This is beautiful.

Yeah, this is South East London's
coral reef.

I love science experiments!

I soak up the science as I find out

how washing our clothes
can cause a plastic problem.

We're finding a lot of fibres
in the marine environment

and we're finding them in marine
creatures as well.

And we join
the Blue Planet Live team

as they descend into the unexplored
depths of Costa Rica.

You know what, Gillian?

It seems like us Brits enjoy nothing
more than finding a nice spot

in the sun on the coast and tucking
in to the humble fish and chips.

Well, you know, the great British
tradition of fish and chips

originated in the 19th century.

But the chip originated from
Belgium - les pommes frites -

and fish came from Spain - pescado
frito - who'd have thought it?

Doesn't sound that British at all!

When did this simple supper
land in Britain?

I've been investigating.

Fish and chips first appeared
on our high streets way back

in the 1860s and fast became
a firm favourite for the nation,

so much so that it was one of
the few foods that wasn't rationed

during World War II.

I usually go for cod or plaice
myself,

but there's always plenty of other
white fish on offer,

although some varieties may not be
quite what you were expecting.

Who would have thought that
underneath that lovely crispy batter

could be a kind of shark?

But you wouldn't have seen shark
advertised on any chippy menus.

The industry has been using
different names for decades to make

the fish in the dish more palatable
for the public.

Rock salmon, rock, huss, rigg,
flake -

these are all traditional
names for shark in the UK.

Dr Andrew Griffiths of Exeter
University has been researching

the use of shark products in the UK.

Andrew and his team have trawled
fish and chip shops

up and down the nation

and brought fish suppers back
to the lab for DNA testing.

We've analysed around about 89
fish and chip samples

and what we discovered is that over
90% of the samples that we analysed

were actually identified
as spiny dogfish.

Spiny dogfish were once one
of the world's most abundant shark,

but our taste for it
has led to numbers being decimated.

Now endangered
in the northeast Atlantic,

the EU has banned targeted
fishing since 2010.

But the UK waters are still
no safe haven.

Spiny dogfish have a low
reproductive rate,

meaning their numbers are slow
to increase.

Like many fish, they shoal
together for protection,

but this behaviour is the species'
downfall because when they get

caught accidentally,
it's in devastating numbers.

However, there are people
trying to help.

I'm joining the team
from SharkStuff,

who are attempting to tag spiny
dogfish, headed by Georgia French.

They're there somewhere, but you've
got to land over the shoal

get on top of them... Yeah.
..and find them. Exactly.

It's hoped that
by tagging the spiny dogfish

they will be able to identify
their favourite marine habitats,

in the hope of making them
protected sites

to safeguard the species
in the future.

The team will be using specialised
equipment to assess the size

of specimens in the water.

The stereo...ster... Oh, I'll be
honest, I can't pronounce its name.

Using the stereo photogrammetry
equipment,

we're getting measurements of
sharks in the water with big sharks.

One of the worst things you can do
is take them out of the water,

but it's important that you do know
how big they are, so we wanted

to come up with a method where you
could do that in the water.

We're getting bites.

Not spiny dogfish,
but another type of shark -

spotted catfish, to be precise -

and they're small enough
to land safely

and take manual measurements from,
which will help judge

the accuracy of the equipment.

Perfect.

Bye, bubs.

That's actually quite
a cool defence mechanism

where they curl up like that.

In South Africa,

they've got species they call shy
sharks because they're supposed

to hide, like, under their tail,
they curl up.

As well as small spotted catfish,

the equipment is also picking
up spotted ray - a close relative

of the shark and a congo eel,
even a dolphin.

No spiny dogfish yet,
but it's fishing, isn't it?

There's no guarantees.

One man who knows the challenges
of sea fishing better than most

is Paul Burridge.

He's an angler, not a scientist,
but he's more than happy

to offer his expertise to the cause.

Yeah, there's something on there.

Little 'un.

Got a nipper.

About five years ago,
I started fishing large sharks

and found it interesting
that the amount of information

to be gained from the scientific
community as well as fishermen

being out here on the boat.

It's all worked hand in hand.

Well, unfortunately, it looks like

we're going to go back without
a spiny dogfish today,

but are you surprised?

Catching any fish on cue is always
a bit of a red herring really -

it's quite hard work, but there's
not a lot of them around.

They are under threat and when
there's not many of them,

it's a needle in a haystack.

What I really want to ask you
about on this is how important

you feel, from a fisherman's side
of things,

the stuff that SharkStuff are doing?

I love their ethos.
You know, it's education.

And most anglers,
especially big fish anglers,

don't want to harm their catch.

And if we can show the data to say -
"This is a better way of doing it,

"this is how we suggest things are
done" - it's important.

We haven't been lucky on this
expedition, but organisations

like SharkStuff are providing hope
for the spiny dogfish,

and scientists like Andrew
want to see changes in legislation.

It'd be much more useful
to have clearer labelling

which becomes much more tied
to a very small number of species

or a single species, which would
allow the consumer to know exactly

what they're buying.

If we embrace adaptations
like these,

we can make informed decisions
and carry on enjoying

our fish and chip suppers
without harming our sharks.

So how can we enjoy a 150-year-old
British tradition

without harming our fish stocks?

Well, the Marine Conservation
Society have a Good Fish Guide

where you can see which fish species

are the most sustainable -
the green rated -

and the least sustainable -
the red rated.

There's loads more information
on the website.

Very often, it's the scale
of the fishing that's the issue,

and there's a lot
of smaller companies

that just aren't finding it viable

to compete against
the bigger outfits,

but there's one lone fisherman
in Devon

that's trying to keep
alive the tradition.

For centuries, the seas around
Britain have provided a livelihood

for coastal communities.

Hope Cove is one of these

historically vibrant
fishing villages.

In the 1930s, there were more
than 30 men fishing from here.

But times have changed.

Centuries-old traditions and the
heritage of a Devon fishing village

are on the brink
of being lost forever.

Over the years, one by one,

the fishermen have left and now only
one man remains.

My name is David Morgan.

I'm the last full-time fisherman
living in Hope Cove.

If you're in fishing,
you have to work every day

that presents an opportunity
for you to go fishing.

I mean, our day typically starts

at four or five o'clock
in the morning

and if you're not prepared
to do that,

then don't entertain the idea
of going fishing.

We normally arrive at the first
fleet of the pots,

any time between half past five
and six o'clock in the morning

and we would haul maybe 500-600
pots continuously

until about half past two,
three o'clock in the afternoon.

In the winter, the weather
on average might affect us

to the extent where we don't go to
sea for perhaps two or three weeks.

The long-term decline is due largely
to the fact

that it's no longer possible to earn

a decent living
from small-scale fishing.

Over the last 10 or 15 years,
the value of crab, in real terms,

has gone down considerably.

The crew don't live in Hope Cove.

I would go so far as to say
that it's impossible to find

any crew in Hope Cove and that's
been the case for...

..many, many years.

The resident local population
is just getting smaller and smaller

and smaller, to the extent now
where, in the winter,

you've barely got a community
of people here at all.

It's very interesting
that when we were young lads,

there were many of us
that couldn't wait to jump aboard

a fishing boat
and find out about fishing,

but I don't see that happening
at all any more.

I cannot see the fishing industry
in Hope Cove ever returning

to anything like it was
50, 60 years ago.

There's nothing to say

that small-scale fisheries
shouldn't succeed...

..but you've got to be very
efficient at what you do.

It's very difficult to compete with
the larger players in the market.

I don't see too many coming
into the industry at all.

It's a poignant story that young
film-maker Nick Adams captures

perfectly and it's one
that's representative

of many of our fishing villages,

but there are some marine
communities that are bouncing back,

so I went to go and find out more.

I've come to Weymouth to meet
Charlotte Bolton.

She's part of a national drive
to survey our seas

and has a passion for spectacular
shellfish - the spiny lobster.

What on Earth is a spiny lobster?

It's like a lobster. But spiny!
It has spines... But spiny!

All right, OK! And it lacks the big
pincers and it has stripy antenna...

OK, right. ..so it tends to work
in the reef.

And they've had a pretty rough time
of it

in the past, haven't they? Oh, yes.

Spiny lobsters were
effectively extinct in this country.

Basically they were
fished out in the '70s and '80s

and we just didn't see them at all.

So that was a combination

of commercial fishing pressures
and also divers.

Divers have to take their share
of the blame here because they were

also responsible for collecting them
and we simply didn't see them.

So it's really nothing to do
with it being predated on

or anything to do
with the environment,

but it was purely overfishing.
It's us.

It's us - the apex predator is to
blame again, unfortunately, yes.

And I think... I mean, now they're
incredibly valuable

because there are so few of them,
but we are seeing them coming back

and last year we saw them here in
Dorset which was... It was amazing.

As a local diver, it's really
exciting to know that they are back

in our local waters.

So what on Earth has brought
around all this change for them?

If we're honest, we don't
really know.

It might be one of these big
planetary,

you know, sort of ocean systems.

The Atlantic Decadal Oscillation
has been mentioned.

Who knows? Is it the warming seas?

We don't really know. And I suppose
that's one of the things, isn't it?

There's so much going on with our
oceans at the moment, man-driven

and otherwise, that it's hard
to be able to put your finger

on why things might be changing.

Yes, and it's so complicated out
there, you think...

You know, one little thing changes
and then that knock-on effect -

this whole web of life
we just don't know

and that's what for me makes it
really exciting.

But whatever that change is, to have
spiny lobster back on the shores

of Britain is fantastic, isn't it?
Yes, it is, it is.

As a diver, I love them.

You can hear me finding them
underwater because I get

all high pitched and I scream.

They are just...they are really
exciting to find.

I don't think I'd ever get
bored of it.

It's not all doom and gloom.

Some of it is, but there are plenty
of good news stories out there,

which is really exciting.

You know, I love a story like that

and look at the passion
Charlotte's got.

It is amazing, but I have an even
bigger news story for you.

Steve, listen to this.

RAPID PULSING

Well, that's a bit different,
isn't it?

What am I listening to there?

That is the very first minke whale

to have been recorded
off the east coast of Scotland.

No way! How cool's that?

It is very.

The minke whale is one of
the largest marine species

that regularly visits the Scottish
coast, but it's secretive

and unpredictable which means much
of its behaviour remains a mystery.

They can grow up to eight or even
ten metres in length,

but are hard to track
because of their behaviour.

Unlike humpback whales and dolphins,

they don't display
when they come to the surface.

The Scottish Association for Marine
Science and Marine Scotland Science

are thrilled to have captured
that audio and it is the beginning

of hopefully learning more about
these really mysterious animals.

And to be finding out
that kind of thing

is really ground-breaking, isn't it?

Now before Chris Packham headed
off to Mexico for Blue Planet Live,

he caught up with a biologist
that has dedicated his career

to looking at some of the wildlife
that lives on our British coasts.

Today I've come to meet a man called
Paul Naylor and I like him.

He applies classic
naturalist values,

enhanced skills in observation,

only he does it in the marine
environment

and another thing I like
is that he's content to work

with common species,

but he wants to know not
just the species but individuals

and learn about their personalities.

Paul, what is it that lured you
in there in the first place?

When the conditions are right
and you can get in there and see

the animals that live in there,
you just find amazing characters.

Hold on. We've got some
perfectly good animals on land.

Yeah, but we see them all the time.

The ones in the sea
are less familiar to us.

And one of those animals you've got
to know is the tompot blenny

and this is a familiar species
to anyone who's had their toe

in a rocky...rock pools
and just offshore, isn't it?

Yeah, it's a very close relative
of the common blenny or shanny,

which is that small
greeny-brown fish

that people know in rock pools
so well.

What's so... I mean, I think apart
from them looking...

A very sort of early '70s
glam rock fish, isn't it? Yeah.

Yeah, they look great

and then from a study point
of view, what's so brilliant

about them is that they've these
individual skin markings

and you can recognise them,

so you can follow an individual.

And this is a rogue's gallery

on one particular reef
that we study.

These are your blenny friends...
Yeah.

..that you've got to know
as individual animals

and that gives you a lot more
empowerment

to study them. Absolutely.

For a start, you can find out
how long a male -

cos they're territorial,
the males -

how long they keep territories.
Go on. Tell me.

I would imagine a fish like this,
two or three years seasonally.

Certainly up to five years... Five!

..five years and they'll keep
the same territory. OK.

I know you've got some footage here

that you've shot
of some of your blennies.

Let's have a look at this.
What's going on?

Well, what's happening here is -

this is a female
and she's laying eggs

and, behind, is one
of the territorial males

and appearing is what we thought
was another female,

but when we looked very close
up later, we found that you could

just see the glands underneath it
that make it a male.

But this male has snuck in
presumably to try and fertilise

some of the female's eggs...
Exactly.

..which is a strategy that we see in
all sorts of other animals. Exactly.

But never before in the tompot
blenny

before these sets of observations.
And this is not a one-off.

You've seen this repeatedly.
Absolutely.

And just there, he seems to have
sussed it out and off he chases him.

Do you know what's striking
about this is that just out there,

literally a few metres
off the beach,

this new behaviour's now only
being uncovered.

Exactly. What else have we got?

Another animal is the spiny
spider crab.

Now all round our coasts...

This was filmed near Torquay
and groups of them come together

and they go through what's called
the pubertal molt, where they emerge

from their old armour as adults.

But what we didn't realise was that
when they got this new armour,

they need to camouflage it again

and it's quite an intricate process.

They rub each piece of seaweed
on the spines on their backs

until it sticks. So they're
dressing up in seaweed

as a means of camouflaging
themselves? Yes.

Maybe they've evolved the spines
specifically to make it possible

to attach the seaweed. I think so,
because in between the big spines,

there are these tiny curved hooks
which, I think, is what the seaweed

attaches to and those hooks look
just like Velcro,

the hooks on Velcro, so the
spider crab invented Velcro.

What about that?

But, Paul, you don't have to be
a diver to access marine life.

I mean, rock pools are full of
similar species, aren't they?

Absolutely, yes.

Look into any rock pool
and you can see animals

going about their lives.

And if you move things around,
it is an animal's home.

I mean, it could be a blenny's
territory or a shanny's territory.

Exactly. Put it back, and then
safety - a little bit of a concern -

if you're going rock pooling, check
the tide times, good stout footwear,

Wellingtons, that sort of stuff and
if you're a young person, make sure

your parents know where you are.
Absolutely. That's the key thing.

But, look, I have to say thank
you very much.

It's been an absolute eye-opener.
Just out there.

I've been looking at badgers
and birds -

they don't dress themselves up
in weed.

Amazing, absolutely amazing.

And you can see Chris and the team
on Blue Planet Live tonight

when they take another look to see

how healthy the world's
oceans really are.

And the health of the oceans or not,
a lot of it is down to us

and although we're very aware

of the problems
with single-use plastics,

who knew the clothes you wear
can make such an impact?

The UK puts on a staggering
seven billion washes a year,

so, with that in mind,
anything that indicates

they're causing plastic pollution
is a big deal.

I'm visiting a lab

at the International Marine Litter
Research Unit in Plymouth

where Richard Thompson
and PhD student Imogen Napper

have been researching
how washing our clothes

can end up with synthetics
in our seas.

Wow! You know, when you said "lab",

this isn't quite what I was
expecting.

This looks more like a launderette.

It feels a bit like that sometimes,
but, actually, it is a lab.

What we're trying to do here
is quantify how many fibres

are coming off everyday items
of clothing when you wash them.

A lot of people don't know that our
clothes are made out of plastic

and this can be polyester, acrylic
or natural synthetic blends

and when it's swishing and swirling
around in the washing machine,

tiny fibres can come off
and go down the waste water

and potentially into our oceans.

We know that we're finding
a lot of fibres

in the marine environment -
we're finding them in the deep sea,

we're finding them in Arctic sea ice

and we're finding them in marine
creatures as well.

To find out what kind of fibres are
making their way into our oceans,

we're going to run a test
on three different fabrics.

So we've got 100% acrylic
jumper, 100% polyester jumper

and then a blend of polyester
and cotton.

Different colours means different
fibres

and you just use that all the time?
Yeah. See, there was me

just thinking you're separating
your lights and darks. Yeah.

I love science experiments.

Never been so excited about washing.

Each item gets washed
on an identical cycle

with the same detergent at the same
temperature.

MUSIC: Where's Me Jumper?
by The Sultans Of Ping FC

The water from the outlet pipes
is filtered to collect any fibres

that would have gone down the drain
and whatever is found is dried

in a petri dish.

Each sample has come from just one
item of clothing after a single wash

and the next step is to take
a closer look under the microscope.

OK, so first one I can see is blue

and that was the hoodie,
wasn't it? Yep.

This is the blue hoodie
and this was polyester-cotton blend.

This is all of the fluff

that we extracted from that
one hoodie in one wash.

That is unreal, isn't it?

Because normally I'd look at that
as fluff... Mmm.

..but I don't think about what the
fluff is made up of. Yeah.

So this is plastic fluff,

well, polyester and cotton.

Some past research that we did
showed that for a typical wash,

on average, about 130,000
fibres can come off

a polyester-cotton blend wash.

And how many washes did
you get this average from?

I did over 200 hours of washes.
Oh, my word!

So you really do know
your blue hoodies

and the fluff that comes off it. I
know this very well. OK. All right.

So, moving on, what else
have we got?

The next one that we had was
the fluffy black jumper

and this was made
out of polyester,

different material -
completely plastic this time.

It's a big tangled mess.
That looks so different.

For a typical wash, up to 500,000
fibres could come off in one wash,

so three times more
than the polyester-cotton blend.

Wow! All right. And we've still got
another one yet. Number three.

So the next one was the beige
jumper. That was made of...?

Acrylic. Hardest to see,
cos it's beige.

But in our past research, we showed
up to 700,000 fibres could come off

a typical clothes wash,
so the most by quite a mile.

And that is all plastic. Yep.

Oh, my word!

These fibres could make their way
through the sewage treatment works

and into our oceans,
making it a big plastic soup.

So it really is
a one way street, isn't it?

Once the plastics are in there,

it's very hard to get such
small plastics out again.

So what's the answer, then? I'll
just stop wearing acrylic, I guess.

Well, it's really not that easy.

Even though in our research

we've shown that acrylic shed
the most fibres,

it can depend how the clothes
are made, how they're woven,

so we need to look right down to the
beginning of the manufacturing stage

so we can stop them shedding fibres
when we're washing them.

The devil really is in the detail
with this, isn't it?

At every stage of the clothes
being manufactured... Yeah.

..to the way that they're washed.
It's very complex.

When it comes to shed-ability, we
can say that mixed fabric is bad -

the polyester three times worse

and the acrylic, by a country mile,

is bottom of the tops.

And these are the culprits here -

the microfibres, the plastic fibres
that come out the clothes

and there's no real solution
to it yet,

but it's all being looked into
and one option is to put together

a textile that doesn't give
off microfibres in the first place

and the other is to find a way
to capture the microfibres

before they make their way
to the ocean.

And this is a prototype
to do just that.

It's a washing machine filter.

The idea being that every single
washing machine would be installed

with one of these to capture
all those microfibres

as micro plastic pollution entering
the environment.

And it wouldn't just benefit
the large marine mammals,

it would benefit
the tiny things as well

cos even plankton is being affected
by this micro plastic pollution.

And plankton is the cornerstone
for every ocean ecosystem,

as The One Show's Mike Dilger
found out.

If someone sent you the greatest
migration on Earth,

what would you think of -

wildebeest crossing
the Serengeti plains,

caribou crossing the Arctic tundra?

Nice guesses but, no,
because it's plankton

and this amazing journey
happens just off our shores.

The animals that take part
in this huge migration underpin

all marine life
in the British Isles,

but, for the most part, you'll
probably have never even seen them.

I've come to the west coast of
Scotland and the beautiful island

of Mull to take a closer
look at plankton -

these tiny
but incredibly important organisms.

During the summer months, the seas
off the British Isles transform,

filling up with swirling patterns

covering hundreds of square
kilometres,

which can even be seen from space.

These patterns are, in fact,

blooms of tiny plants
called phytoplankton -

most no bigger than a pinhead.

These tiny plants are so numerous.

they produce over half
the oxygen we breathe,

they even give the sea its smell
and, most importantly,

they're the food of the creatures
I've come to investigate today.

I'm on a quest to find zooplankton,

some of the weirdest animals
on the planet.

They're so small that if we want
to find them, we need to look out

for the predators that feed on them.

Zooplankton make an incredible
journey each day,

moving between the surface waters
where they feed

and the dark depths
where they're safe from predators.

Some of these tiny individuals

travel to depths of half
a kilometre.

This monumental feat by so many
minuscule animals makes them part

of the biggest migration
on the planet.

Here off the Hebrides, the upwelling
waters, which are rich in nutrients,

create a plankton hot spot.

And in these waters
off the coast of Tiree,

it isn't long before we find
what we're looking for.

This is fabulous behaviour.

You've got sand eel
that feed on plankton,

being pushed
to the surface by bigger fish

and then we've got the birds
piling in from the top.

I'm watching gannets diving from
25 to 30 metres up and slamming

into the water and they're feeding
on big shoals of fish

and where there are fish, there are
going to be huge plankton blooms

and that's what we want to see.

Zooplankton may be amongst the most
numerous animals on Earth,

but catching them isn't easy,

so we've brought plankton
Professor David Pond to help us.

With his specialist net system,

we soon catch some of these marathon
migrators while they're up

at the surface feeding
and head back to the lab.

David, this is a whole new world.

So talk me through this very
distinctive creature

with what looks like a fantail
and red in its body.

It's a really large copepod.

It's about seven millimetres long

and it's kind of the lion
of the sea.

It's carnivorous and it basically
eats all the other chaps.

There's one as well that's
incredibly distinctive

with long antennae that also has red
running through its body

and this seems almost
the most numerous.

It's found across the North
Atlantic, up into the Arctic.

It's really important as a source
of fish food

for commercially important species
and you can see along here,

running along the length of
its body,

you can see an oil sac like lipid -
it's fat basically.

Fish like herring and mackerel feed
on these copepods in huge numbers

and then transfers that lipid,
that oil, into its tissues.

And that's the omega-3 that
we need to eat for our own diet.

Absolutely.

It's incredible to think
that the world's marine life

is so reliant on such tiny animals,

so the next time you're sitting
down to a fish supper,

remember -
it's all down to the plankton.

Microscopic organisms are crucial
to healthy ocean habitats

like coral reefs.

Coral are affected by climate
change, however,

because as sea temperatures rise,
it causes them to go white.

It's called bleaching and can lead
to the coral dying.

It's a really sobering sight
but I went to London to meet

a scientist who thinks
he may have come up with a solution.

Jamie Craggs of the Horniman Museum
is leading the fight

to save the world's coral,

and this little piece of Australia's
Great Barrier Reef holds the key.

Hello. Nice to meet you.
Nice to meet you.

Oh, my goodness. This is beautiful.

Yeah, this is southeast London's
coral reef. That's incredible.

So this is where all the action
happens? Absolutely, yeah.

Reproduction is obviously
the process

that a species and population
continues,

so studying reproduction gives us
that fundamental knowledge,

but then getting them to reproduce
is very difficult.

So our work is focusing
on triggering them to reproduce

and understanding what happens
in the wild,

replicating that in aquariums.

Some of these individual
corals are special,

because they're genetically
resistant to coral bleaching.

It's hoped their offspring can help
save the world's dying reefs.

But breeding coral is easier
said than done.

These corals only spawn over just
a couple of nights a year,

so there's a very small window of
time to get the material you need

for your experiments.

Coral spawning is triggered by
a precise combination of day length,

water temperature and the phase
of the moon.

To get coral to breed in the lab,

all these conditions
must be mirrored exactly.

So that's the sun.
How do you replicate a moon?

We have four LED lights and then

a ping-pong ball's been cut in half
to act as a diffuser.

And really importantly, three bits
of sticky tape have been put

over the top to make sure it's

exactly the same amount of light
as a full moon.

In the natural world, other
creatures live amongst the coral,

like sea urchins.

These resilient little animals graze
on algae

which can kill the coral
if left unchecked.

So these are going to be like room
mates or tank mates, I should say,

for the corals. Yeah, so we've got
four different age groups here

of urchins and they each have
their own use.

So when they're nice and small,
they're great with the baby corals.

As they get older, we then move
them in to control the algae

in with our adult corals.

If the young corals are to feel
at home,

they need the sea urchins there too.

And Jamie has a breeding
programme to maintain his supply

of juvenile urchins.

It's all kicking off in here, isn't
it? Absolutely. Oh, my goodness.

We've got five males spawning
and then a female over here

is producing eggs. That's a huge,
massive egg. That's incredible.

The Horniman Museum was the
first institution in the world

to successfully breed coral
in captivity

and they filmed the magical
moment it all began.

Once the coral starts to spawn,
the eggs and the sperm are collected

so that Jamie can maximise
the chances of fertilisation.

While we can get the corals to spawn
in a very planned way now,

we can rear potentially hundreds
of thousands of embryos.

The next frontier and the next
challenge for us is to get those

hundreds of thousands of larvae to
settle, grow into baby corals

and then have hundreds of thousands
of corals.

As the coral grows,
it's transplanted into tanks.

Here, the team has come up with
a novel way

of monitoring their health.

I'm guessing these are here
for a reason.

Yeah, if we use the light, the blue
light in combination with goggles,

it allows us to highlight
the fluorescence

that are inside the corals.

That is beautiful.

They glow.

Why would coral need to fluoresce?

There's a lot of debate about it.

One thought is the proteins,
the fluorescent proteins, act

as a sunscreen, a bit like suntan
lotion, for the corals

and it protects them against
the harsh UV rays of the sun.

In successfully spawning, breeding
and growing coral,

Jamie has made amazing progress.

The next hurdle is to grow thousands
of warm-water-tolerant coral

and take them back into the oceans

to help fortify our reefs
against climate change.

That was a superb bit of research

and hopefully will make
a real difference.

Tomorrow, we're going to be looking
at British coral reefs,

only in much deeper water.

And to help understand
the challenges, our cameras follow

the Blue Planet Live team as they
drill down

deep off the coast of Costa Rica.

So it's about five o'clock
in the morning.

We've been up since about four,
four-thirty.

We're about 50 miles off

the Pacific coast of Costa Rica.

As you can probably see,

we're just about to rendezvous
with the RV Atlantis.

The Atlantis is a scientific
research vessel

carrying some very special cargo.

We are filming with Erik Cordes,
who's the leader of this expedition

to a series of sea mounts that have
never been explored before.

What they're going to find -
who knows?

These underwater mountains
rise from the ocean's floor

but their peaks never break
the water's surface.

To embark on the expedition,
Erik Cordes will be using

a submarine called Alvin.

So, Alvin, by the time we get
on board, is already in operation.

They're doing their dive checks

and making sure it's completely
safe, it's operational.

So that's all going on
as we turn up,

so as soon as we start the day,

as soon as we get on board,
it's go.

So they're just about to go
on a dive.

You can see here at the front
of Alvin,

you've got all the area

where essentially these robotic arms
can pick up samples.

We've got soil samples here.

You've got places where they can
pick up specimens and keep them

until they're on the way up.

Just as a bit of filming equipment,
it's pretty incredible.

You have pan and tilt cameras
up the top there.

It's equipped with 4K camera.

It's got cameras on the arms here.

It can actually grab cameras
with these arms and then place them

on the sea floor and then be
able to move around them.

It's absolutely incredible.

All of them of course have got their
own pressure...specialised casing,

so they can deal with the pressures

at thousands
and thousands of metres deep.

So we haven't be able to take our
own cameras into Alvin,

so we are using
the cameras that they've got.

You know, we've been having to test
that out as we go.

Usually you do that back at base -

you'd do that before you'd arrive,
but it's still just a challenge,

just to try and work that out
and make sure that we get it right,

because Erik is only going
down once.

So if it goes wrong...

..then we could have a problem.

With final checks complete,
Alvin is ready to start its mission

exploring the sea mounts.

So Erik's just left now.

He's going to be down there
for about eight hours.

I just can't wait to see
what he comes back with.

It's going to be amazing.

Watch Blue Planet Live

to find out the results of Alvin's
deep sea dive.

That's it for today.

Don't forget Blue Planet Live
on BBC One tonight.

We're going to be back tomorrow,
same time, but from Scotland

for our final Blue Planet UK.
See you then.

In our final programme, I delve
into the deep of our British oceans.

We're actually looking at an area
1.5km deep.

We learn about one of the most
secretive species in UK waters.

I remember the very first time I saw
a seahorse in the wild.

Absolutely amazing.

Chris reveals why he has a passion
for our coastline.

I feel a closeness to the sea
because of the birds

that are an intrinsic part
of that environment.

And there's a sight to behold as
herring return to Scotland's coast.

There's a great wall of herring
going round and round me.

It's fantastic.