Attenborough's Life That Glows (2016) - full transcript

As dusk gives way to twilight,

the encroaching darkness

is lit by life.

These dancing lights around me

are produced by fireflies -

creatures that have the strange

ability to produce light.

They bioluminesce.

And fireflies are not alone.

Scientists are finding ever

more strange and wonderful

glowing life forms

all around the world.

Living light has always

fascinated me.

And the discovery of more and more

luminous creatures raises more

and more questions.

Why? What is the light for?

And how is it made?

In recent years,

scientists have begun to find

answers to those questions.

And in doing so,

they've taken us into a world

that is utterly unlike our own.

However astonishing these images

look, they are all real.

With help from new cameras,

one designed just for this film,

we can reveal this

extraordinary phenomenon

as it has never been seen before.

Bioluminescence holds many

mysteries.

But we do know that fireflies use it

to attract the opposite sex.

Each species has its own flash code

and WE can join in the conversation.

I'm going to use this rod to

fish for fireflies.

It's the actual rod used

by the scientist who was the first

to decipher the various call

signs of fireflies.

And there are 15 different species,

at least, around here.

Each with its own signal.

Biologist Jim Lloyd used the rod

to imitate male fireflies

and so decode their various

light patterns.

He discovered that the call sign

consisted partly in

the actual flight path of the

species concerned.

There are, for example,

some fireflies which move steadily

horizontally, like that.

And there are others which

turn their light on as they climb,

like that.

But in addition to the flight path,

they flash a particular signal.

It's rather like Morse code.

So I should be able to use this

light myself.

There is a female amongst these

leaves here,

which will emit a single flash.

And the male of her species waits

for precisely four seconds,

and then answers back with a flash.

Whereupon she immediately gives

another flash, like that.

And the male then knows that he

is going to be a welcome visitor.

But the message has recently been

shown to be more than

a simple signal for sex.

A female judges

the quality of a male's genes

by the precision of his timing

and the brightness of his light.

She encourages her chosen suitor by

directing her lanterns towards him.

And it seems this male sent out

all the right signals.

We are now discovering that

this language of light

even has local dialects.

Throughout the summer months,

from Florida to southern Canada,

gardens, fields and forests sparkle

with these mating messages.

Time-lapse photography reveals

the extraordinary extent

of this courtship.

Some species flash only at dusk.

Others prefer the forest

canopy for their light show.

Some species make their flashes more

conspicuous by choosing

the very darkest

places in which to display.

I can see virtually nothing here,

except the flashes.

And this particular species has

another trick, too.

It synchronises the displays.

Individuals flash together.

Each individual is

triggered by its neighbour,

and soon waves of light

pulse through the woods.

Speeded up,

the wave becomes clearer.

Between the waves,

an impressed female can respond

with two flashes of her own.

And the males home in on her.

But she can only choose one.

These displays peak for just

a few nights in June,

which could explain why

they were only recently discovered.

Why they all flash together

is still a mystery.

It's surprising how little

we know about bioluminescence.

Fireflies are perhaps

the best understood

but some living light is still

very perplexing indeed.

With dawn, the sexual

signals of the fireflies are drowned

by the increasing flood of light.

The flies take

refuge in the undergrowth,

away from the sharp-eyed

predators of the day.

But right now,

Iight is being produced by life

in the soil under my feet.

The threads of certain fungi form

a glowing underground network.

But why would a fungus shine in the

permanent darkness of the soil?

We simply don't know.

And for years,

fungus bioluminescence,

Iike much other living light,

was written off as a beautiful

by-product of evolution with

no function.

But some species only

glow above ground and only at night,

when their intense green light

is very obvious.

If it was just a biochemical

accident then surely

they would shine all the time.

The glow certainly attracts insects

and the theory is that these

visitors spread the fungal spores.

So here, too,

just as with fireflies,

we're learning new things

all the time.

But much living light remains

a beautiful enigma.

And throughout history,

stories of bioluminescence were

often thought to be pure fiction.

In the 1870s, Jules Verne,

the French science-fiction novelist,

wrote this in his book,

20,000 Leagues Under The Sea.

"At seven o'clock in the evening,

our ship, half-immersed,

"was sailing in a sea of milk.

"At first sight,

the ocean seemed lactified.

"The whole sky seemed

black by contrast with

"the whiteness of the waters."

Jules Verne may have

based this story

on a myth told to him by sailors.

But in 1995, the captain of

a British vessel wrote

a real-life account

in his ship's log.

"At 18:00 hours on a clear

moonless night,

"while 150 miles

east of the Somalian coast,

"a whitish glow was

observed on the horizon.

"And after 15 minutes of steaming,

the ship was completely surrounded

"by a sea of milky white colour with

a fairly uniform luminescence.

"And it appeared as

though the ship was sailing over

"a field of snow or gliding

over the clouds."

Reports like this are rarer

than the supposed sightings

of the Loch Ness Monster.

And there was no

photographic evidence.

Some scientists, including marine

biologist Steven Haddock,

were curious,

and sought confirmation from above.

We wondered if you could find

one of these ship reports where

they record sailing through

one of these milky seas,

and actually find the corresponding

satellite data that cover

that area at that same time.

So we looked at the satellite

from the ship report in 1995

and it was somewhat of

a eureka moment.

We cleaned up the noisy sensor

image from the camera,

we mapped it onto the ship track,

and this 300km feature

emerged on the map matching exactly

with what the ship had reported.

So it was really an amazing moment.

We were able to document the full

extent of the milky sea over

three successive nights

as it rotated with the currents.

So satellite images from

the space age validated

a piece of maritime folklore.

On rare occasions,

the oceans do glow.

But what was causing a glow

so bright that it could be

seen from space?

The answer can be found at the back

of a neglected fridge.

Left for a couple of days,

this sea bream starts to glow.

The fish itself has no

light- producing ability.

The glow is, in fact,

produced by bacteria that are found

in almost all seawater when

they start to feed on decaying fish.

On rare occasions when currents and

temperatures cause a large bloom of

algae in the ocean, these very same

bacteria also feed on dying algae.

Once they reach a critical

concentration,

their secretions trigger

others to glow.

They were glowing in such

numbers that they can be

detected by a satellite in orbit.

Bacteria are among the most

ancient forms of life,

so they may have been the very first

living things to glow.

But why they did

so is still debated.

Today some animals have stolen

the genes of the bacteria,

and incorporated them

into their own DNA.

Others have simply kidnapped

the bacteria themselves.

These lights are made by captives,

which are farmed in special organs

below the eyes of flashlight fish.

They have harnessed the bacterial

glow for many purposes.

We can only see them because our

special cameras use infrared light.

But to a predator,

the fish look like this.

A confusion of lights which makes it

hard to pick a single target.

Just before they change direction,

the fish give a quick blink.

These lights have

other functions, too.

They act as headlights to illuminate

the sea floor

as the fish search for food.

They may even help a fish to flirt

with the opposite sex.

Unlike their captive bacteria,

flashlight fish use living light for

functions we now understand.

But how is the light made?

While it might appear magic,

it's actually a straightforward

chemical reaction that happens

when a substance is mixed with

a particular enzyme, like this.

Hey, presto, light.

The exact chemical formula varies

according to the species.

The reaction is very similar to that

with which bacteria produce energy.

Indeed, it could well be that the

first luminescence was

a by-product of that process.

An evolutionary accident that

has been co-opted by the fish to

help them survive.

The chemicals involved are

quite harmless.

In fact, you can

actually buy a lollipop which,

when you put it in hot water, glows.

But to be truthful, I don't really

find that very appetising.

Perhaps, at the back of my mind,

there's a memory of those

bacteria on rotting fish,

which tells me

that things that glow aren't

all that nice to eat.

Bacteria may have been the

first living lights,

but then many other organisms

also developed the ability.

From jellyfish to fungi and

insects,

bioluminescence has evolved

independently over 50 times,

and is now produced by thousands

of different species.

And defence seems to be

a common function.

Millipedes are found

across the globe.

Many are active during the day,

scuttling across the damp

forest floor.

They can do this with impunity,

because they are deadly poisonous.

Their bright colours are a clear

message to predators -

"Do not eat me.

I am laced with cyanide."

But what about millipedes

that are active at night?

They are no less toxic than those

that are active during the day.

But, of course, colours at night

are no warning at all.

Could it be that

luminescence is a way

of warning off night-time predators?

These extraordinary millipedes

are only found

in the high mountains of California.

Their bioluminescence has never

been filmed before.

They can't be sending signals to one

another, because they're blind.

Their living light evolved

separately from bacteria,

from a chemical process that helps

millipedes conserve water

in dry environments.

But since the millipedes already

contain cyanide,

the light evolved a function.

To my eyes, he doesn't look

very bright.

But my eyes are not

the eyes of a night-time predator,

or indeed of our specialist camera.

And to both of them,

this could look very bright indeed

and be a real warning.

When scientists made clay

models of these millipedes,

half of which glowed,

nocturnal predators were more likely

to attack those that didn't glow.

This simple experiment produced

a clear result.

Living light can act as a warning.

But proving the function

of bioluminescence is not always

so easy,

as a recent discovery has shown.

These, surely, are like

creatures from science-fiction.

Luminous earthworms.

A few years ago,

a lady living in the Loire Valley in

central France went out during the

evening to look for her dog which

was digging a hole in the garden.

And in the bottom of the hole,

the soil was glowing.

It was these earthworms.

She could hardly believe her eyes.

And she went

and told people what she had seen

and few people would believe her.

The species of worm was already

known, it lived over quite

a lot of France, but no-one had

ever seen it glow before.

Perhaps that's because few people

went out in the middle of the night

digging a hole,

especially without a light.

But eventually,

science recognised these creatures.

But why should they luminesce

in the darkness of the soil?

Nobody knew.

This blue light had gone

unnoticed by science until 2010,

when biologist Marcel Koken first

saw their eerie glow.

We are trying to find out why this

animal produces light.

A thing living underground.

Why produce light?

No use for it, apparently.

Is it just a by-product of some

internal chemistry?

Or could the glow be used to

frighten off attackers?

These ground beetles are voracious

predators and they love earthworms.

The worms look like ordinary ones

until the light goes out.

Our special camera gives us

a privileged view of what's

happening in the dark.

Marcel's experiments have

shown that the worms can

control their brightness.

When the beetle touches part of the

worm, its light gets brighter.

So it could be that in case

a predator tries to bite it,

it lights up,

that scares the predator.

The predator goes

off and the earthworm can escape.

The beetle bites,

and the worm's entire body

bursts into light as it

struggles to break free.

But the beetle doesn't seem

put off by the glow.

If this is defence,

it isn't working here.

Marcel is still

looking for the function.

Perhaps other predators are put

off or perhaps the worms use

Iight to find each other.

So it seems that this beautiful glow

has a function which

we still don't understand.

The world of living light is

full of mysteries.

The French worms went

unnoticed for so long

because they produce their eerie

light underground.

But there are rare occasions

when luminous life is

all about revealing yourself.

May 2015.

While the southern aurora

illuminates the night sky above,

the sea below produces

a strange blue glow.

Each wave causes

a ripple of intense colour.

The animals in the bay

notice it first.

Wading birds are attracted

to small crustaceans

caught in the glow.

Each movement alerts others to

this rare spectacle.

People gather to marvel at this

once-in-a-lifetime event.

That is amazing!

I've never seen anything like this

before in my life.

That's wicked.

LAUGHTER

It may look like something from

Willy Wonka's chocolate factory,

but the phenomenon is real.

A mass bloom of microscopic

organisms caused by a rare

combination of climate

and nutrients.

Under this microscope, I've got

a drop of ordinary seawater.

And it's full of tiny organisms,

invisible to the naked eye,

called dinoflagellates.

And if I disturb them in some way,

they combine two chemicals in their

body to produce a flash of light.

Watch.

Dinoflagellates are one of the

biggest single-celled

organisms known.

They are 1,000 times bigger

than bacteria.

They are neither animal nor plant,

but have characteristics

of them both,

and when conditions are right in the

sea, as they were in Tasmania,

they bloom in enormous numbers.

Bioluminescent tides like this

one are certainly rare.

However, dinoflagellates are found

in huge numbers all over the world.

They are among the most widespread

of all bioluminescent life.

Wherever they exist,

these single-celled creatures

highlight anything that moves.

But why do dinoflagellates

behave in this way?

It's certainly not to entertain us,

though it obviously does.

Well, it could be that it is a kind

of burglar alarm -

that when a shrimp

or some other animal

that feeds on the dinoflagellates by

filtering them out,

comes along and starts to feed,

it is, in doing so,

illuminating itself.

So that attracts the attention

of perhaps bigger fish that might

feed on the shrimp.

Just as a flashing burglar alarm

alerts the police to a thief,

the dinoflagellates expose

their attacker to its enemies.

The shrimp is revealed to a

cuttlefish, with fatal results.

And so the cuttlefish can

hunt in total darkness.

But while the dinoflagellates'

light can work in this way,

it is still debated

if that's why they do it.

Whatever the reason, the magic

created by their light can be

one of nature's most magical

spectacles.

Bow-riding dolphins are

revealed as dazzling outlines.

Whenever these lights appear,

the way life in the ocean hunts

and hides is transformed.

Perhaps dolphins are guided

to their prey by the light

of the dinoflagellates.

Only now has it become possible to

film these scenes with such clarity.

But every night, spectacular light

shows like this play out

somewhere in the vastness

of the oceans.

While exactly how dinoflagellates

use bioluminescence remains

unproven, there are other instances

when the burglar alarm effect

has been clearly demonstrated.

Caribbean coral reefs

are some of the

most well-dived waters

in the world...

..by day.

At night, it's a different world.

A crab searches for a tasty morsel.

This is just what it's looking for,

the delicate

tentacles of a brittle star,

a relative of starfish.

But the brittle star has

a surprisingly effective defence.

When disturbed, it unleashes a

dazzling weapon, raising the alarm.

Having been revealed,

the crab makes a run for it.

And the normally well camouflaged

crustacean becomes easy prey

for the octopus,

even in the gloom.

Scientists have only recently proved

the light helps the

brittle star drive off predators or,

better still, to get them eaten.

It's in the open water, where

there's nowhere to hide, that the

burglar alarm defence is most

effective.

Fish hunt small invertebrates

silhouetted against the night sky.

Ostracods, tiny crustaceans no

bigger than a grain of sand,

emerge from the reef.

Cardinal fish are common

predators of the small and unwary.

But when they strike

an ostracod,

they get more than

they bargained for.

The ostracod discharges

a bioluminescent flash bomb,

one of the brightest

forms of living light.

And the cardinal fish

quickly spits it out.

The light is

so bright that it shines through

the body of the fish, temporarily

blinding it, and this normally

invisible fish becomes an easy

target for a predator.

Ostracods,

with their flash bomb defence,

are found throughout

the world's oceans.

But in the Caribbean,

they employ their glow to

attract as well as to repel.

It's something that researchers

Gretchen Gerrish

and Trevor Rivers are studying.

The spectacular mating

display of ostracods.

But they can't even begin to work

until the moon has set.

A fully moonlit night is not dark in

the eyes of an organism that

depends on their own light that they

create, and so darkness truly

is just a starlit sky,

no moon present in the sky at all.

Diving without torches in near total

darkness, Gretchen

and Trevor are entering a world that

few people ever witness.

You are immersed in darkness,

you are immersed in water.

And you see streaming stars floating

past you and they're being

produced by these tiny crustaceans

that we barely understand.

By releasing small amounts

of glowing liquid as they swim,

male ostracods leave

a trail of lights in their wake.

The series of precisely timed dots

tell the female where

he will be in exactly half a second.

But as one male starts to display,

another and another join him.

And as they synchronise,

they fan out into this

firework-like display of light.

It's one of the most awe-inspiring

things I've ever seen.

With every research trip, Trevor

and Gretchen discover new species,

each with its own light language.

Ostracods and fireflies use

bioluminescence

to find potential mates.

And it can be an efficient means

of getting your message across,

but it's not foolproof.

Those messages can be hacked.

There's a love cheat in

this situation.

There's also a female

of a particular species here that,

when she sees the males

of a different species fly past,

answers with their particular

call sign, and that attracts them.

And when they arrive,

instead of mating with them,

she has her own dastardly

way with them.

She mimics the flash

patterns of other species.

An unsuspecting male is lured in.

Fireflies contain toxins thought to

protect them against most predators.

But this femme fatale is not

put off.

And she eats him alive.

In fact, it may be

the toxins that she is after.

She can't produce such

chemicals herself.

So she tricks and then devours males

of different species to obtain them.

If she can't get males to come to

her, she goes after them.

And a good place to look for one

is on a spider's web.

A male firefly is ensnared.

As the spider venom takes effect,

his flashing turns to

a constant glow.

The femme fatale is

alerted by the dim glow,

and she flies straight onto the web

to steal the spider's catch.

As the spider

struggles to keep its prey,

she dazzles it with her lantern.

Using her light, the firefly can

clearly see the spider

and avoid the web.

The confused spider loses out.

Predation turns out to be one area

where light-making life

has been very creative.

Like a scene from the surface

of an alien planet,

these termite mounds have lodgers

living in their walls.

The luminous larvae of click

beetles wait in burrows.

Insects are drawn

to their death by the green glow,

Iike moths to a flame.

And the beetle larvae gorge

on the steady supply of

unsuspecting victims.

These predators work as individuals.

There is another insect that

excels in deception.

But it works alongside

thousands of its own kind.

From outside, this cave shows no

sign of the astonishing

things that go on inside.

The entrance is fringed with

a curtain of silk,

woven by the larvae of a

kind of gnat.

They move back

and forth along the rocks,

Iowering sticky strings of saliva

from the roof of the cave.

As night falls, the walls

and ceiling of this cavern become

nature's very own planetarium.

The trap is set.

The cool, blue light produced

in each larva's tail is the lure.

Other insects that hatch

and emerge in the cave instinctively

fly upwards to the sky.

But this is not a starlit sky.

It's a deathtrap.

Bioluminescence is clearly

a powerful tool

to these life forms that possess it.

But it is only

effective in darkness.

Each dawn,

the bright rays of the sun overwhelm

the power of living light.

For all of the wonders

of bioluminescence

in the plains and woodlands

of the Earth, there is

one place where living light is

virtually the key to existence.

The world of eternal darkness,

the deep sea.

The Western Fire is

one of the world's most advanced

deep sea research vessels.

In the black depths there are no

edges.

No boundaries, nowhere to hide.

Predators and prey have therefore

had to develop some

extraordinary strategies to

stay alive.

And many do so

with the help of light.

Dr Steven Haddock has spent

the last 25 years studying the

Ieast known part of our planet,

the ocean depths.

I think people

look at bioluminescence,

this ability to make light, they

think of it as a very magical thing,

but once you see the diversity

and the range of functions that

bioluminescence serves for animals

in the ocean, it is

clear that it is a critical

part of the whole ecology

of the system.

Until recently, it was all but

impossible

to collect living bioluminescent

creatures from the deep.

But this remote submersible,

known as the Doc Ricketts,

is equipped to do just that.

They are trying to find new life

and clues as to why light-making has

evolved in so many forms.

In the control room,

thousands of metres above, Steve

and the crew navigate past

alien-like life forms.

Nice.

Wow.

But in truth, it is us

who are the aliens down here.

Although very sophisticated,

the Doc Ricketts'

own remote cameras are not sensitive

enough to record bioluminescence,

so they use bright lights to find

and film these creatures.

To have any hope of observing

their light-making powers,

the research team needs to

bring them to the surface.

Gentle suction and remotely

controlled canisters are used to

delicately scoop up

the rare sea creatures.

Vampire squid.

Yes!

Viper fish.

Perfect.

Oh, look at that!

And dragonfish.

They don't just sound like something

from a sailor's tale of

fantasy monsters,

they look like them, too.

This is one of the few dragonfish

that has ever been seen alive.

And it's one of the even fewer that

have been captured unharmed.

Yes! Yay! Oh, my gosh.

Once they arrive on the ship,

thousands of metres

above their normal environment,

there is no time to waste.

The enormous pressure change is

likely to cause any

bioluminescence abilities to

disappear.

The race is on to try

and observe those abilities

and understand their functions.

Wow.

In some species,

it seems to be defensive.

Like the circling

flashes of the Atolla jellyfish.

Or the rippling light

waves of the Beroe comb jelly.

In other species,

like this viper fish,

Iight is used not only for defence,

but to lure prey.

These pyrosomes, colonies of minute

translucent creatures,

use light to communicate

within the colony.

The team's experiment shows that as

one colony begins to glow,

its neighbours light up in response.

What could they be saying?

Thanks to the delicate sampling

methods of the Doc Ricketts,

the team are able to

observe a living

and luminescing dragonfish,

a sight few have ever witnessed.

Whatever their function,

one thing unites all these

types of bioluminescence -

their otherworldly beauty.

And this beauty is the result

of an evolutionary arms race

where light is a weapon to

blind or deceive.

In response, some animals have

evolved the most sophisticated

and bizarre eyes on the planet.

The rare barreleye fish has eyes

that can only look upwards,

through the top

of its translucent head.

Searching for prey above.

It is so rare,

catching even a glimpse of it alive

is a huge achievement.

And the same is

true for the cock-eyed squid.

It has one normal eye and one

strange, upward-looking eye.

At this depth, it is

too dark for human eyes.

But the faintest

light from the surface,

half a kilometre above, can just

reach this twilight zone.

Firefly squid normally

live at these depths.

To prevent themselves from being

seen from below,

they hide themselves with light.

It's a strange paradox.

In this dark world,

light can be used for camouflage.

At close range, the light-emitting

cells, called photophores,

are easy to see.

But from a distance, they break up

the outline of the squid

and it merges with the background.

It's an elegant solution

used by many creatures

when a silhouette can be

a death sentence.

In shallower waters,

the colour of the light changes

so the squid, as it gets closer to

the surface, uses green photophores.

The lives of firefly

squid are short.

When they are only a year old,

mated females make their final

journey, to the surface to spawn.

But even in their final moments,

they are both spectacular

and valuable.

All along the coast here,

these squid, which die naturally

after spawning,

are gathered as a local delicacy.

It's largely through this

fishery that we know

anything at all

about the firefly squid.

Like so many deep sea creatures,

their daily lives are still

virtually unknown.

What we do know is that their world

is dominated by bioluminescence.

We've come a long way from watching

fireflies

in the woodlands of Pennsylvania.

Organisms that produce

light on land may be exceptional

but in the sea,

creatures that do so, like these

comb jellies,

are, in fact, the norm.

In the oceans and on land,

Iiving creatures of many kinds have

harnessed the power of light in

extraordinary ways, to mate, to lie,

even to hide under a cloak of light.

Yet, with the latest cameras

and technology, we are

only beginning to understand

the lives of luminous creatures.

There remain many mysteries. But

what a beautiful world they create.

And what a beautiful world awaits

the scientists of the future.

During this programme,

we've had to use cameras

that are far more sensitive than our

own eyes

and about as sensitive as many

of the animals that we are showing.

The eye is one of evolution's

greatest achievements.

And nature has certainly devised

some fiendishly complex

and sensitive examples.

Some of which are designed

specifically to see bioluminescence.

When we enter the dark,

we barely notice bioluminescence.

But after a few minutes,

physiological changes

take place in our eyes that

enable us to see living light.

Cameras have always struggled to

replicate

what the human eye can do,

but with special low-light cameras,

we can now record glowing

light at least as well,

and sometimes better,

than we can see it ourselves.

But being able to film the glow is

only one part of the solution.

To really understand light on Earth,

you need to be able to record

the creature themselves as

they make the light.

This camera allows you to film

in low-light levels

in a completely new way.

The beam of light

comes in through the single lens,

but it is then split into two,

and one camera records on one

Iight frequency, and the other

on a different light frequency.

One of the cameras is sensitive to

infrared light, invisible to

most animals, but which allows

the camera to record in the dark.

The second camera records only the

bioluminescence,

which is mostly blue or green.

The two are then

combined into one picture.

And that way you can get

pictures at a low-light level,

not only of bioluminescent animals,

but even the environment

in which they are living.

This technique, pioneered

by film-maker Martin Dohrn,

allows us to enter the world

of bioluminescent creatures,

and also to contribute to

new science.

With this type of camera,

there are many things

I see on these images which

I wouldn't be able to see normally.

In the past, scientist Marcel

Koken has been unable to

study the worm

and beetle without using a light.

But when he did,

the light would frighten the beetle

and overpower the worm's

bioluminescence.

With the help of Martin's camera,

Marcel is able to observe

and record the beetle and worm

encounter for the first time.

Having decided working with two

cameras simultaneously wasn't

already hard enough, the team

decide to take them underwater.

The objective was to film

the beautiful mating display

of ostracods -

tiny, one millimetre long

crustaceans in the dark

swirling currents of their natural

habitat. A huge challenge.

Martin, how was it tonight?

We had a lot of problems.

Tonight, it went smoother.

It's calmer. Much, much calmer.

A lot of what

I saw looked utterly amazing.

Martin's beam-splitting system

makes it possible to film

the bioluminescence as well

as the tiny ostracods, as they leave

Iights in their wake.

However, the scientists are not

done.

Marine biologist Gretchen Gerrish

hopes the camera will enable

her to film groups of males

that aren't flashing,

swimming alongside

the individual that is.

Something that has only ever been

seen in the lab.

These males, known as sneakers,

are invisible to a normal camera,

because they leave no night trail.

But our camera, nicknamed Bertha,

could change all that.

So, how was Bertha?

Bertha is awesome.

She was filming sneakers

and you could see them swimming.

She's a bit of a beast.

What do you think, Trevor?

Did you get any good footage?

It was just awesome.

This is opening the doors for

so much.

The scientists are keen to

get their first look at the combined

images from Bertha.

The infrared does show there is

a spiralling group of males,

intent on intercepting the female,

before she can reach the male

that has done all the hard

work of attracting her.

And there are far more competing

males

than the scientists had expected.

It's an ostracod soup.

There's thousands of them.

What, to our eyes, is a beautiful,

orderly display is in fact

an ostracod free-for-all.

Lots of males try to

cash in on the efforts of a few.

The amount of information you could

fire from this is something

we've been trying to do

for the last five years.

Yeah, that's a paper, right there.

What? You mean in that short clip?

There's not a paper there.

Close to it.

But having hi-tech kit

is only part of the story.

Since much of the bioluminescence

is little-known,

just finding it is often

the biggest hurdle.

The crew are about to head

out on their most ambitious shoot.

Tonight, we're going to try

and film something that we know is

found all over the world,

and it happens every night in every

ocean, almost anywhere,

and yet, in terms of getting

information from people

as to where we might find it,

and when the best time is,

there is nothing.

As night falls, they head away from

shore and any artificial light.

And soon, they are sailing in the

sea laced with dinoflagellates.

These blue flashes can be seen

in almost any ocean at night,

with the lights out.

But this alone

is not what the crew came for.

They are hoping to meet some

special visitors.

Working on a rocking boat

in complete darkness with

a prototype camera is one

of the trickiest challenges Martin

has faced in his career.

After a week searching the dark sea,

here they are.

Dolphins.

To be out at night, with clear skies

and beautiful stars,

and everywhere there are

flashes of light,

and when dolphins turn up, the show

just gets more extraordinary still.

It really is one of the most amazing

things I've ever seen in my life.

Scenes like this are happening

across the oceans,

yet this is one of the few times

they've ever been caught on camera.

New technologies

and new ideas are creating

a revolution in our way

of seeing the world.

And of understanding

life that glows.