Original subtitles

This tiny South Pacific island may not look like much.

But it was once a mountain that towered above the waves.

Now it barely breaks the surface.

Yet still it attracts a spectacular array of wildlife.

There are thousands of islands just like this

scattered across the Pacific,

and all are teeming with life.

So what has reduced the mountains of the Pacific to this?

Almost seven miles deep,

the Pacific is the deepest body of water on the planet.

But sometimes,

the seabed shoots to the surface.

Behold one of nature's rarest sights...

...the creation of a new island.

This is Kavachi in the Solomon Islands...

...one of the most active undersea volcanoes in the world.

In the last 100 years, Kavachi has emerged above the waves just a handful of times,

but so far to no avail.

Powerful waves keep sweeping its efforts away.

This is a view of the Pacific as seen from space -

a vast expanse of water that covers almost a third of the Earth's surface.

Today, only 1 % of this vast ocean is land,

and much of it owes its existence to the explosive powers

of volcanoes like Kavachi.

1,500 miles north of the equator,

perhaps the most famous group of volcanic islands in the world -

Hawaii...

...still one of the most volcanically active areas on Earth.

And this is Kilauea.

Like all volcanoes, it's plumbed into the very heart of the Earth -

home to a lot of hot, angry rock.

Rising from 60 miles below the ocean's floor,

this lava has flowed non-stop for 25 years.

On the lower slopes,

the lava travels at less than 100 metres an hour,

betraying little of its awesome power.

Nothing can survive

this smouldering blanket.

As the crust cools,

it is lifted by the lava still flowing beneath it.

The advance is relentless and unpredictable,

changing direction without notice.

Roads here are regularly swept away

and some are now buried under 35 metres of rock.

In the last 20 years,

more than 200 homes have been destroyed by Kilauea's flow.

And it doesn't stop here.

Rivers of liquid rock plunge over the cliffs

and into the water below.

This is the front line in a battle between the elements.

Most of the lava is swept away before it can settle.

But, inch by inch, the island grows.

Below the waves, the battle rages on.

As the lava hits the water, it's burning at over 1,000 degrees Celsius.

Cold currents from the deep send its temperature plummeting,

releasing steam with explosive consequences.

The lava fights on,

but it's only a matter of time before its fire goes out.

The commotion attracts attention.

But it will be some time before it's safe to settle here.

Pouring into the sea,

Hawaii's lava has forged almost 2.5 square kilometres of new land

in less than 25 years.

It's cold, hard rock -

bleak, threatening and barren.

But there are some colonisers who just won't be put off.

'Ohi'a lehua, a native plant and symbol of Hawaii, is among the first

to flourish on this new land.

This spindly bush will grow into a 30m-tall tree,

its bright flowers food for a variety of birds,

like these Hawaiian honey creepers.

But how on earth can a seed become a tree

in a place where there is no soil and no sign of fresh water?

The long, tenacious roots of the 'ohi'a

wend their way through the cracks

and penetrate deep into the rock in search of trapped water and nutrients.

Their quest leads them to a remarkable, subterranean world.

Once, a raging torrent of lava flowed right through here.

When it stopped, this was all that remained...

...a lava tube...

...pitch black,

constantly damp...

and very cold.

Can anything survive in this harsh world?

Amazingly, yes.

Patches of bacteria line the walls, feeding on the minerals

in the volcanic rock itself.

But that's not all.

This is the small-eyed big-eyed hunting spider -

a curious name for any spider,

let alone one whose eyes barely function.

But in total darkness, eyes are little use.

Although he can't see it, the spider has company.

Rare crickets scale the rocks...

...while translucent earwigs

and milky millipedes forage for food.

These are cave specialists,

or troglobites,

and they never leave the lava tube.

Over time, most have lost their eyes and colour...

...like this plant hopper.

Its tail has a curious function.

Any predator biting it from behind will be left with nothing

but a mouthful of irritating, waxy hair.

This is a place of ghostly stillness -

a definite advantage for the small-eyed big-eyed hunting spider.

With its super-sensitive leg hairs,

it can pick up the slightest movement in the air...

...and it senses the cricket's presence long before it's close enough to ambush.

As prey are few and far between,

this may be its last meal for some time.

With no light and little vegetation,

only the specialists survive here.

But that isn't the case for all lava tubes.

Southeast of Hawaii, straddling the equator, like the Galápagos Islands.

As on Hawaii, some of the volcanoes here are still very active.

The coastline of Isabela - the largest island -

is covered in volcanic rock.

Here a very different kind of animal can be found in the rocky tubes.

The chicks of Galápagos penguins.

Without the lava tubes, they wouldn't survive.

Cool and sheltered, the tubes are the perfect nursery, protecting the chicks

from the unforgiving temperatures outside.

Unforgiving if you're a penguin, that is.

Adult Galápagos penguins only cope by doing something the chicks can't yet do.

They take a dip.

The adults plunge into cool waters

that have travelled all the way from the Antarctic.

Who says penguins can't fly?

There's lots of food here, as schools of fish

are drawn to the shelter of these rocky, volcanic shores.

But while the parents are out fishing...

...their chicks are home alone.

Back in the lava tube,

there's something creeping around.

A Sally Lightfoot crab has penguin on its mind.

It's dark, so the crab can't be sure exactly what it's up against.

This time, it's taken on more than it can handle.

Had the encounter been just a few days earlier,

the outcome might have been very different.

Crabs are major predators of baby penguins.

Far to the west, in the Solomon Islands, lives an animal

that depends on another characteristic of volcanoes for its survival.

Heat.

Meet the megapode, also known as the incubator bird.

Megapodes work hard to find the perfect spot to lay their egg.

And, thanks to this island's volcanic springs,

that spot is just a foot or two below the sand,

where the temperature is an ideal 33 degrees.

But some megapodes don't seem as keen to dig as others...

...and this can sometimes lead to fights.

With the dispute finally settled, the victor lays an egg

and covers it with sand.

Parenting over,

the megapode leaves the time-consuming job of incubation

to the volcano.

While the megapode thrives on a volcano's heat,

back in Hawaii,

there's a creature that thrives on the exact opposite.

This is Mauna Kea...

...a dormant volcano and Hawaii's tallest mountain.

Incredibly for a tropical island, its peak is covered with snow.

Little can survive at such freezing heights.

Bugs blown up here don't stand a chance.

Stunned or trapped in snow, they slowly die.

But not everything succumbs to the cold.

These tiny creatures are wekiu bugs.

Their cells are filled with a special kind of antifreeze

that allows them to live around the snow line.

Originally, wekiu bugs were seed-eating vegetarians,

but their descendants have adapted to this hostile environment.

Now with a taste for blood,

they are the Pacific's own vampire bugs.

Needle-sharp mouthparts pierce their dead and dying victims,

before they suck out anything that's left inside.

Measured from the sea floor,

the wekiu's home is the tallest mountain in the world...

...about a kilometre taller than Everest.

But it won't hold this record for ever.

After millions of years of growth,

this mountain is slowly but surely losing height

at a rate of 20 centimetres every 100 years.

In fact, it's so massive that it's buckling the seafloor beneath it

and sinking into the ocean.

Mauna Kea's future can be glimpsed in the Society Islands of French Polynesia.

The peaks of these islands once rose much higher than this from the ocean floor.

It's been almost two million years

since their volcanoes first broke through the ocean.

But erosion is washing away their volcanic cores.

Now the only growth occurs just below sea level,

on what was once the mountain's sloping flanks.

In the shallow waters around an island's base,

coral reefs rise towards the surface.

Of all the formations in the Pacific,

these reefs are by far the richest in life.

There are hundreds of different kinds of coral.

And all are made up of millions of tiny creatures called polyps,

each covered in a hard skeleton.

Reefs are home to thousands of specialists...

...like these razorfish that blend into the staghorn coral around them.

But not all animals here need to blend in.

Grey reef sharks.

The reef's top predators, these sharks patrol the waters on strong currents.

But without all the life on the reef here,

they could never exist in such numbers.

They may be idle right now,

but they won't remain this way for long.

As night falls...

it's feeding time.

Needlefish stalk the coral shallows in search of food.

Predators by day, at night they become the prey.

Speeding away at 20mph,

the needlefish give the chasing sharks a run for their money.

But it's hard to escape from so many.

Daylight reveals another reef predator.

Crown-of-thorns starfish... coral killers.

Climbing over their prey,

they secrete digestive juices that turn the inside of the coral to liquid.

Then they suck out the nutrients,

leaving nothing behind but a ghostly skeleton.

In only a few days, they can kill huge swathes of the reef.

Fortunately, coral has an unlikely ally...

...the Triton's trumpet.

Believe it or not, this is a predator on the prowl...

...its killer pounce revealed only when time is speeded up.

An unlikely hero perhaps.

But the Triton's trumpet is an invaluable control on these starfish.

And the crown-of-thorns isn't the only coral killer on the reef.

The razor-sharp beaks of bumphead parrot fish

also put a dent in this living landscape.

A single fish can chew its way through

a staggering five tonnes of coral a year.

Smaller parrot fish, colourful cousins of the bumphead, are also at it.

But they all give a little back...

...as the ground-up coral comes out as sand.

This is island building of a different kind.

So, some of the Pacific's most elegant beaches

have sprung from a less than stylish birth.

Above the water, time seems to stand still.

But the Pacific islands are always changing...

if slowly.

This is Bora Bora...

...a volcano in what could be called "late middle age".

The sloping flanks have slipped further into the sea,

pushing the reef away from the shore.

A lagoon is formed.

It's a patchwork of coral outcrops and sand.

Protected from the powerful waves of the surrounding ocean,

all kinds of animals take refuge in these calm, shallow waters.

Some take comfort in their bold appearance.

But others take shelter in the coral.

Such as these sedentary and appropriately named Christmas tree worms,

filtering food from the gentle currents.

For many, entire lives are played out within the clumps of coral.

Mandarin fish.

A dozen of them may inhabit one outcrop.

Males are always on the hunt for a mate, and competition is fierce.

Disputes start with a polite warning.

The rising dorsal fin is a clear signal to back off.

But sometimes, going for the jugular is the only way.

The fight over, it's time to get down to business.

Spawning is a brief affair.

Then the eggs are left to the mercy of the current.

Life in the lagoon depends on a daily flushing of water from the open ocean.

This flows in through channels formed by natural gaps in the reef.

With each changing tide, a soupy river of debris and nutrients

flows out of the lagoon and into the blue.

This attracts all sorts of life.

One regular visitor to the channels

is the gently gliding manta ray.

It filters out minute creatures floating in the currents.

But there's more than enough to go around.

Schools of snapper take the lead...

...while a wall of fusiliers mops up the remains.

Across the South Pacific,

time continues to work its magic on rock.

Millions of years of erosion and sinking have reduced

the volcanic mount of Maupiti to little more than a hill.

Eventually, this hill will disappear too.

And when it does, it will look like this...

...Mataiva, a coral atoll.

Rising above the waves, a coral atoll's reef surrounds a shallow lagoon.

Where there was once a mighty peak, now there is only water.

There are thousands of atolls like Mataiva dotted around the South Pacific,

their size and shape determined by the original volcano.

Some atolls are round, their rings unbroken...

...while others have been bent out of shape

by ocean currents and earthquakes.

And a few span huge distances,

a testament to volcanoes whose size and power were once truly colossal.

Rangiroa in French Polynesia.

Over 30 miles wide,

its lagoon is so large that if you were floating in its centre,

you wouldn't see land in any direction.

The story of land building in the South Pacific

may start with volcanic eruptions...

...but it doesn't end there.

A volcano once formed an island here, but it sank back below the surface.

Now it's on the rise again.

This is the extraordinary Kingman Reef.

Over 3,000 miles from the nearest continent,

it is one of the last pristine coral reefs left in the world.

As tourism and fishing are banned here,

the reef is about as close as you'll get

to the Pacific as it used to be... before humans arrived.

Part of what makes Kingman extraordinary

is the 200 types of coral found here.

But there's also something else.

And it's helping to build the reef.

Giant clams...

everywhere.

More than you'll see on any other reef in the world.

When giant clams spawn, they expel millions of eggs into the water.

And when one starts, all the others quickly follow.

The sea soon turns cloudy...with life.

Giant clams can live for over 50 years.

But it's their death that is crucial to the creation of land in Kingman Reef.

These few hundred metres of coral rubble and dead clams

are the only visible signs of Kingman above the water...

...providing a valuable rest stop to passing voyagers.

Eventually, seeds brought by ocean currents and birds

will turn it into a new island.

And once vegetation is established,

wildlife is never far behind.

Being good long-distance travellers,

fairy terns island-hopped their way here to French Polynesia.

The ancestors of these blue lorikeets, however,

were brought here by some of the earliest Polynesians.

It could be described as the ultimate honeymoon destination.

Though the waters off these shores don't always appear too inviting.

Blacktip sharks have adapted to swim in less than a foot of water.

They come to these shallows to hunt for smaller fish.

Like Kingman Reef, all signs of these islands' volcanic past

have long since disappeared.

But without it, land could never have got started here.

In the very west of the Pacific, however,

volcanoes have had a helping hand.

Palau - the jewel of Micronesia.

As with many islands in the Pacific, its volcanic peaks still linger on.

Beyond their shores are other familiar scenes.

Barrier reefs.

And small coral atolls.

But here, there's something different.

The reefs of Palau have risen from the deep,

not slowly, like Kingman, but suddenly.

35 million years ago, powerful earthquakes forced them high above the waves.

And Palau's rock islands were created.

Some are up to 200 metres tall.

Exposed cliffs now reveal their rock's true origins.

It's limestone, created by crushed coral and ancient shells.

Since those earthquakes, there's been another big change here.

At the end of the last ice age,

large areas of this landscape became flooded as the ice melted.

In the process, over 70 marine lakes were created.

Cut off from the outside world,

these lakes produced some unique animals.

One of these was an ocean predator with long tentacles.

But here, it evolved into a harmless, graceful wanderer.

Jellyfish normally feed on small fish.

But in the lakes, there was little prey.

So their bells have become a home to millions of tiny photosynthesising algae.

When exposed to sunlight, these algae produce sugars,

which in turn provide their hosts, the jellyfish, with food.

Now, each day, the jellyfish migrate across the lake,

following the arc of the sun.

Their only obstacle, the occasional anemone that tries to catch them

as they float past.

And sometimes fails.

So, with little danger, and a never-ending supply of food,

the jellyfish have multiplied...

..and multiplied...

..and multiplied.

It's strange to think that Palau was once just a piece of endless ocean.

But nothing lasts for ever.

The never-ending rise and fall of land in the Pacific

will continue to produce strange and wonderful worlds like these.

At the start of it all will always be the incredible natural force

that created land here in the first place...

..the ocean volcano.

During the making of this series,

the team filmed in many remote locations across the South Pacific.

These isolated islands are home to some truly unique wildlife,

many of them found nowhere else on Earth.

But life on remote islands comes at a price.

Any change can be disastrous.

And this is what the team came face to face with on the Galápagos Islands.

The Galápagos are very special.

It was of course these volcanic islands that inspired Darwin.

And here, there are an astounding number of creatures

that exist nowhere else in the world.

One of these unique animals is the Galápagos penguin.

And this is what the team wanted to film.

Recently, their survival has become increasingly uncertain.

And the crew knew this could make filming very difficult.

Fortunately, the cameramen had close ties with the Galápagos.

Richard Wollocombe worked as a wildlife guide on Galápagos for several years.

He was aware of the penguins' problems,

so this filming trip was a chance to find out more.

Ironically, it's people's love of the islands

which have actually caused some of the problems.

The major problem is, the big increase in the amount of tourists going to Galápagos

has meant that the service industries who supply those tourists

have increased the amount of products going to the islands,

and those products can contain very damaging species, introduced species,

which can have huge detrimental impacts on the native flora and fauna.

Richard hoped to film inside the nests of Galápagos penguins.

How easy this was going to be, nobody knew.

Today's penguin population stands at less than 2,000,

dramatically less than it was 25 years ago.

Now introduced species are adding extra pressure to the lives of the penguins.

When Richard arrived, the Galápagos authorities

were tightening their regulations. And the final filming permission

was down to a meeting with the National Park in person.

They've decided to collaborate with our filming.

And they're really excited we're doing the filming

because they can collaborate with us with some scientific investigations.

Few observations had ever been made inside a penguin's nest,

so filming might reveal some interesting behaviour.

I'm fascinated because I've never seen it on television or any video,

so it's a first.

However, filming couldn't start immediately.

First, Richard's equipment had to be fumigated and placed in a freezer

to kill off anything living - plant or animal - that was carried in on the plane.

It's so amazing to see the level of dedication going on here in this job.

They're going through our equipment with a fine-tooth comb,

taking absolutely everything apart

and looking at the finest details.

The National Park had cause to be concerned.

Disaster had nearly struck Isabela Island,

the very place Richard hoped to film the penguins.

Just a few introduced goats multiplied to a staggering 100,000.

Their indiscriminate grazing devastated the landscape,

destroying the shade and food of the unique giant tortoises.

Something had to be done.

The government of Ecuador took on the battle,

and, against all odds, managed to eradicate every goat.

With the goats gone, the landscape quickly recovered,

and the population of the island's precious giant tortoises increased.

The goat invasion did not affect the penguins.

But the penguins have other pressures

and not all man-made.

Galápagos penguins are the most northerly penguins in the world.

And they can only live here because of the cold, nutrient-rich current,

flowing all the way from the Antarctic, which supports huge shoals of fish -

penguin food.

But just a small change in water temperature

can dramatically alter this food source.

And that is exactly what happened.

In 1982, the strongest-ever-recorded El Niño hit the islands.

El Niño, a natural phenomenon,

brings warm waters which destroys the huge shoals of fish.

As a result, penguin breeding failed

and their population crashed by almost 70%.

Ahoy there!

After 72 hours in the freezer, Richard's film equipment had passed inspection,

and he was ready to set off.

He was joined by Carolina Larrea Angermeyer,

a local scientist who had agreed to take Richard

to a location where she knew penguins regularly nested.

It would take 16 hours to reach Isabela Island.

There, they hoped to find the chicks

hidden in rocky crevices near the shoreline.

But the search didn't start well.

RICHARD: What's that?

A dead penguin. I saw two more over there.

- Do you think it's a cat? - Probably.

I'm not sure because it's not very recent, so you cannot really see much of it.

- There's the wing there. - Yeah, it's the wing there,

but the rest of the body, you cannot really tell, because...

RICHARD: Man, can you believe that? It's pretty depressing if it WAS a cat.

So this is one of the troubles in Galápagos,

is that we have introduced mammals

that these animals have not evolved to compete with.

The search continued.

But they didn't find any penguin nests at all.

We still have to check a number of other nests, but, um...

I don't think we'll get a chance to see penguin chicks here.

Carolina set up mosquito traps, as there were also fears

that avian malaria may have reached the islands.

We might have a bit of a dilemma,

because what we were expecting to find was life, not death.

We were expecting to find a new generation of penguins in their nests,

um, being tended by their parents.

And it was really a big disappointment to find just dead penguins everywhere.

Tourism is growing by 10% a year in the Galápagos,

and with people

come invading species.

It's impossible to apply the strict fumigation regulations

the filming kit was subject to on the importers and traders.

Other South Pacific islands, like Hawaii, are fighting the same battle.

There, an estimated 30 new species arrive every year.

For several days, Richard and Carolina travelled around the islands

searching for penguin nests.

And at last, good news.

We have got two little babies, two-week-old chicks about this big,

sitting abandoned on a nest.

Both parents are out feeding right now to try and ensure their survival.

I'm so happy!

I'm really relieved, I have to say. I am...

Phew!

Richard worked quickly to get the camera in place,

and all his efforts were rewarded.

A great view of an adult feeding the chicks.

And to top that, an unexpected visitor to the nest.

RICHARD: The chicks didn't like the crab at all.

Suffice it to say, there was a constant tit-for-tat going on in the nest.

The crab would go forward, and the penguins would bite it.

Then the crab would recede into the shadows.

It was really interesting for a while. It looked quite ominous.

No, it's quite unusual, I think. I don't think that's...

Certainly no-one in Galápagos has seen

what goes on in the nests at night-time.

So this is all very novel, very new and very, very exciting.