0:00:47 > 0:00:52This tiny South Pacific island may not look like much.
0:00:53 > 0:00:58But it was once a mountain that towered above the waves.
0:01:01 > 0:01:04Now it barely breaks the surface.
0:01:08 > 0:01:12Yet still it attracts a spectacular array of wildlife.
0:01:19 > 0:01:22There are thousands of islands just like this
0:01:22 > 0:01:25scattered across the Pacific,
0:01:25 > 0:01:28and all are teeming with life.
0:01:36 > 0:01:40So what has reduced the mountains of the Pacific to this?
0:01:56 > 0:01:57Almost seven miles deep,
0:01:57 > 0:02:01the Pacific is the deepest body of water on the planet.
0:02:03 > 0:02:04But sometimes,
0:02:04 > 0:02:07the seabed shoots to the surface.
0:02:10 > 0:02:14Behold one of nature's rarest sights...
0:02:14 > 0:02:16(MUFFLED EXPLOSION)
0:02:16 > 0:02:19(STEAM HISSES)
0:02:19 > 0:02:22..the creation of a new island.
0:02:24 > 0:02:27This is Kavachi in the Solomon Islands...
0:02:29 > 0:02:33..one of the most active undersea volcanoes in the world.
0:02:34 > 0:02:36(MUFFLED EXPLOSION)
0:03:08 > 0:03:11(HISSING)
0:03:12 > 0:03:17In the last 100 years, Kavachi has emerged above the waves just a handful of times,
0:03:17 > 0:03:20but so far to no avail.
0:03:21 > 0:03:25Powerful waves keep sweeping its efforts away.
0:03:28 > 0:03:31This is a view of the Pacific as seen from space -
0:03:31 > 0:03:36a vast expanse of water that covers almost a third of the Earth's surface.
0:03:37 > 0:03:41Today, only 1% of this vast ocean is land,
0:03:41 > 0:03:46and much of it owes its existence to the explosive powers
0:03:46 > 0:03:48of volcanoes like Kavachi.
0:03:51 > 0:03:541,500 miles north of the equator,
0:03:54 > 0:03:59perhaps the most famous group of volcanic islands in the world -
0:03:59 > 0:04:01Hawaii...
0:04:04 > 0:04:08..still one of the most volcanically active areas on Earth.
0:04:15 > 0:04:18And this is Kilauea.
0:04:20 > 0:04:24Like all volcanoes, it's plumbed into the very heart of the Earth -
0:04:24 > 0:04:27home to a lot of hot, angry rock.
0:04:32 > 0:04:35Rising from 60 miles below the ocean's floor,
0:04:35 > 0:04:40this lava has flowed nonstop for 25 years.
0:04:47 > 0:04:49(GLOOPING)
0:04:49 > 0:04:51On the lower slopes,
0:04:51 > 0:04:54the lava travels at less than 100 metres an hour,
0:04:54 > 0:04:58betraying little of its awesome power.
0:04:58 > 0:05:01(CREAKING AND SPLINTERING)
0:05:03 > 0:05:05Nothing can survive
0:05:05 > 0:05:07this smouldering blanket.
0:05:16 > 0:05:17As the crust cools,
0:05:17 > 0:05:22it is lifted by the lava still flowing beneath it.
0:05:29 > 0:05:32The advance is relentless and unpredictable,
0:05:32 > 0:05:35changing direction without notice.
0:05:44 > 0:05:46(FIRE CRACKLES)
0:05:50 > 0:05:53Roads here are regularly swept away
0:05:53 > 0:05:57and some are now buried under 35 metres of rock.
0:06:15 > 0:06:17In the last 20 years,
0:06:17 > 0:06:22more than 200 homes have been destroyed by Kilauea's flow.
0:06:25 > 0:06:27And it doesn't stop here.
0:06:27 > 0:06:28(ROARING)
0:06:33 > 0:06:35Rivers of liquid rock plunge over the cliffs
0:06:35 > 0:06:38and into the water below.
0:06:38 > 0:06:39(HISSING)
0:06:41 > 0:06:45This is the front line in a battle between the elements.
0:06:45 > 0:06:48(WAVES WHOOSH AND STEAM HISSES)
0:06:58 > 0:07:01Most of the lava is swept away before it can settle.
0:07:18 > 0:07:22But inch by inch, the island grows.
0:07:22 > 0:07:25(MUFFLED CLATTERING)
0:07:28 > 0:07:31Below the waves, the battle rages on.
0:07:31 > 0:07:34(SMASHING)
0:07:36 > 0:07:41As the lava hits the water, it's burning at over 1,000 degrees Celsius.
0:07:44 > 0:07:46(SHATTERING)
0:07:48 > 0:07:53Cold currents from the deep send its temperature plummeting,
0:07:53 > 0:07:57releasing steam with explosive consequences.
0:07:57 > 0:07:59(EXPLOSION AND SHATTERING)
0:08:08 > 0:08:10The lava fights on,
0:08:10 > 0:08:14but it's only a matter of time before its fire goes out.
0:08:21 > 0:08:25(EXPLOSIONS)
0:08:31 > 0:08:34The commotion attracts attention.
0:08:36 > 0:08:41But it will be some time before it's safe to settle here.
0:08:43 > 0:08:45Pouring into the sea,
0:08:45 > 0:08:50Hawaii's lava has forged almost 2.5 square kilometres of new land
0:08:50 > 0:08:52in less than 25 years.
0:08:54 > 0:08:56It's cold, hard rock -
0:08:56 > 0:08:59bleak, threatening and barren.
0:08:59 > 0:09:04But there are some colonisers who just won't be put off.
0:09:06 > 0:09:11'Ohi'a lehua, a native plant and symbol of Hawaii, is among the first
0:09:11 > 0:09:13to flourish on this new land.
0:09:15 > 0:09:19This spindly bush will grow into a 30m-tall tree,
0:09:19 > 0:09:23its bright flowers food for a variety of birds,
0:09:23 > 0:09:26like these Hawaiian honey creepers.
0:09:31 > 0:09:34But how on earth can a seed become a tree
0:09:34 > 0:09:38in a place where there is no soil and no sign of fresh water?
0:10:00 > 0:10:03The long, tenacious roots of the 'ohi'a
0:10:03 > 0:10:06wend their way through the cracks
0:10:06 > 0:10:12and penetrate deep into the rock in search of trapped water and nutrients.
0:10:13 > 0:10:18Their quest leads them to a remarkable, subterranean world.
0:10:18 > 0:10:20(DRIPPING WATER ECHOES)
0:10:28 > 0:10:33Once, a raging torrent of lava flowed right through here.
0:10:33 > 0:10:36When it stopped, this was all that remained...
0:10:38 > 0:10:40..a lava tube...
0:10:46 > 0:10:47..pitch black,
0:10:47 > 0:10:49constantly damp...
0:10:49 > 0:10:52and very cold.
0:10:52 > 0:10:54(DRIPS ECHO)
0:10:55 > 0:10:59Can anything survive in this harsh world?
0:11:00 > 0:11:02Amazingly, yes.
0:11:02 > 0:11:06Patches of bacteria line the walls, feeding on the minerals
0:11:06 > 0:11:09in the volcanic rock itself.
0:11:13 > 0:11:14But that's not all.
0:11:29 > 0:11:32This is the small-eyed big-eyed hunting spider -
0:11:32 > 0:11:35a curious name for any spider,
0:11:35 > 0:11:38let alone one whose eyes barely function.
0:11:39 > 0:11:43But in total darkness, eyes are little use.
0:11:53 > 0:11:57Although he can't see it, the spider has company.
0:12:03 > 0:12:05Rare crickets scale the rocks...
0:12:16 > 0:12:19..while translucent earwigs
0:12:19 > 0:12:22and milky millipedes forage for food.
0:12:22 > 0:12:25These are cave specialists,
0:12:25 > 0:12:27or troglobites,
0:12:27 > 0:12:30and they never leave the lava tube.
0:12:30 > 0:12:33Over time, most have lost their eyes and colour...
0:12:34 > 0:12:37..like this plant hopper.
0:12:38 > 0:12:41Its tail has a curious function.
0:12:41 > 0:12:45Any predator biting it from behind will be left with nothing
0:12:45 > 0:12:48but a mouthful of irritating, waxy hair.
0:12:55 > 0:12:58This is a place of ghostly stillness -
0:12:58 > 0:13:03a definite advantage for the small-eyed big-eyed hunting spider.
0:13:03 > 0:13:05With its super-sensitive leg hairs,
0:13:05 > 0:13:09it can pick up the slightest movement in the air...
0:13:13 > 0:13:18..and it senses the cricket's presence long before it's close enough to ambush.
0:13:27 > 0:13:30As prey are few and far between,
0:13:30 > 0:13:33this may be its last meal for some time.
0:13:34 > 0:13:37With no light and little vegetation,
0:13:37 > 0:13:40only the specialists survive here.
0:13:41 > 0:13:45But that isn't the case for all lava tubes.
0:13:48 > 0:13:54Southeast of Hawaii, straddling the equator, lie the Galpagos Islands.
0:13:58 > 0:14:04As on Hawaii, some of the volcanoes here are still very active.
0:14:04 > 0:14:06(WHOOSHING)
0:14:20 > 0:14:24The coastline of Isabela - the largest island -
0:14:24 > 0:14:27is covered in volcanic rock.
0:14:28 > 0:14:33Here a very different kind of animal can be found in the rocky tubes.
0:14:33 > 0:14:35(CHEEPING)
0:14:39 > 0:14:42The chicks of Galpagos penguins.
0:14:46 > 0:14:50Without the lava tubes, they wouldn't survive.
0:14:51 > 0:14:56Cool and sheltered, the tubes are the perfect nursery, protecting the chicks
0:14:56 > 0:14:59from the unforgiving temperatures outside.
0:15:04 > 0:15:07Unforgiving if you're a penguin, that is.
0:15:11 > 0:15:16Adult Galpagos penguins only cope by doing something the chicks can't yet do.
0:15:18 > 0:15:20They take a dip.
0:15:32 > 0:15:34The adults plunge into cool waters
0:15:34 > 0:15:37that have travelled all the way from the Antarctic.
0:15:46 > 0:15:49Who says penguins can't fly?
0:16:15 > 0:16:18There's lots of food here, as schools of fish
0:16:18 > 0:16:23are drawn to the shelter of these rocky, volcanic shores.
0:16:45 > 0:16:47But while the parents are out fishing...
0:16:49 > 0:16:51..their chicks are home alone.
0:16:54 > 0:16:57Back in the lava tube,
0:16:57 > 0:17:00there's something creeping around.
0:17:05 > 0:17:10A Sally Lightfoot crab has penguin on its mind.
0:17:15 > 0:17:16(CHEEPING)
0:17:20 > 0:17:25It's dark, so the crab can't be sure exactly what it's up against.
0:17:28 > 0:17:29(CHEEP)
0:17:31 > 0:17:32(CHEEPING)
0:17:40 > 0:17:43This time, it's taken on more than it can handle.
0:17:47 > 0:17:50Had the encounter been just a few days earlier,
0:17:50 > 0:17:52the outcome might have been very different.
0:17:52 > 0:17:55Crabs are major predators of baby penguins.
0:18:01 > 0:18:05Far to the west, in the Solomon Islands, lives an animal
0:18:05 > 0:18:10that depends on another characteristic of volcanoes for its survival.
0:18:12 > 0:18:14Heat.
0:18:14 > 0:18:16(BURBLING)
0:18:28 > 0:18:33Meet the megapode, also known as the incubator bird.
0:18:39 > 0:18:44Megapodes work hard to find the perfect spot to lay their egg.
0:18:47 > 0:18:50And thanks to this island's volcanic springs,
0:18:50 > 0:18:53that spot is just a foot or two below the sand,
0:18:53 > 0:18:56where the temperature is an ideal 33 degrees.
0:18:57 > 0:19:02But some megapodes don't seem as keen to dig as others...
0:19:06 > 0:19:08..and this can sometimes lead to fights.
0:19:10 > 0:19:12(SQUAWKING)
0:19:23 > 0:19:27With the dispute finally settled, the victor lays an egg
0:19:27 > 0:19:30and covers it with sand.
0:19:32 > 0:19:33Parenting over,
0:19:33 > 0:19:37the megapode leaves the time-consuming job of incubation
0:19:37 > 0:19:39to the volcano.
0:19:39 > 0:19:41(CHIRRUPING)
0:19:44 > 0:19:47While the megapode thrives on a volcano's heat,
0:19:47 > 0:19:48back in Hawaii,
0:19:48 > 0:19:52there's a creature that thrives on the exact opposite.
0:19:57 > 0:19:59This is Mauna Kea...
0:20:01 > 0:20:06..a dormant volcano and Hawaii's tallest mountain.
0:20:07 > 0:20:13Incredibly for a tropical island, its peak is covered with snow.
0:20:14 > 0:20:18Little can survive at such freezing heights.
0:20:21 > 0:20:24Bugs blown up here don't stand a chance.
0:20:27 > 0:20:32Stunned or trapped in snow, they slowly die.
0:20:32 > 0:20:34(ICE CREAKS STEALTHILY)
0:20:40 > 0:20:43But not everything succumbs to the cold.
0:20:47 > 0:20:50These tiny creatures are wekiu bugs.
0:20:50 > 0:20:53Their cells are filled with a special kind of antifreeze
0:20:53 > 0:20:56that allows them to live around the snow line.
0:20:56 > 0:20:59Originally, wekiu bugs were seed-eating vegetarians,
0:20:59 > 0:21:05but their descendants have adapted to this hostile environment.
0:21:05 > 0:21:08Now with a taste for blood,
0:21:08 > 0:21:11they are the Pacific's own vampire bugs.
0:21:14 > 0:21:18Needle-sharp mouthparts pierce their dead and dying victims,
0:21:18 > 0:21:22before they suck out anything that's left inside.
0:21:27 > 0:21:29Measured from the sea floor,
0:21:29 > 0:21:33the wekiu's home is the tallest mountain in the world...
0:21:35 > 0:21:37..about a kilometre taller than Everest.
0:21:39 > 0:21:42But it won't hold this record for ever.
0:21:44 > 0:21:47After millions of years of growth,
0:21:47 > 0:21:51this mountain is slowly but surely losing height
0:21:51 > 0:21:55at a rate of 20 centimetres every 100 years.
0:21:56 > 0:22:00In fact, it's so massive that it's buckling the seafloor beneath it
0:22:00 > 0:22:03and sinking into the ocean.
0:22:09 > 0:22:14Mauna Kea's future can be glimpsed in the Society Islands of French Polynesia.
0:22:17 > 0:22:22The peaks of these islands once rose much higher than this from the ocean floor.
0:22:27 > 0:22:30It's been almost two million years
0:22:30 > 0:22:34since their volcanoes first broke through the ocean.
0:22:40 > 0:22:44But erosion is washing away their volcanic cores.
0:22:54 > 0:22:57Now the only growth occurs just below sea level,
0:22:57 > 0:23:01on what was once the mountain's sloping flanks.
0:23:09 > 0:23:12In the shallow waters around an island's base,
0:23:12 > 0:23:16coral reefs rise towards the surface.
0:23:24 > 0:23:28Of all the formations in the Pacific,
0:23:28 > 0:23:31these reefs are by far the richest in life.
0:23:35 > 0:23:39There are hundreds of different kinds of coral.
0:23:39 > 0:23:44And all are made up of millions of tiny creatures called polyps,
0:23:44 > 0:23:46each covered in a hard skeleton.
0:23:49 > 0:23:52Reefs are home to thousands of specialists...
0:23:53 > 0:23:58..like these razorfish that blend in to the staghorn coral around them.
0:24:03 > 0:24:07But not all animals here need to blend in.
0:24:12 > 0:24:15Grey reef sharks.
0:24:21 > 0:24:26The reef's top predators, these sharks patrol the waters on strong currents.
0:24:32 > 0:24:34But without all the life on the reef here,
0:24:34 > 0:24:37they could never exist in such numbers.
0:24:50 > 0:24:52They may be idle right now,
0:24:52 > 0:24:55but they won't remain this way for long.
0:25:08 > 0:25:10As night falls...
0:25:10 > 0:25:13it's feeding time.
0:25:33 > 0:25:37Needlefish stalk the coral shallows in search of food.
0:25:37 > 0:25:42Predators by day, at night they become the prey.
0:25:55 > 0:25:57Speeding away at 20mph,
0:25:57 > 0:26:01the needlefish give the chasing sharks a run for their money.
0:26:02 > 0:26:04But it's hard to escape from so many.
0:26:39 > 0:26:43Daylight reveals another reef predator.
0:26:54 > 0:26:56Crown-of-thorns starfish...
0:26:56 > 0:26:59coral killers.
0:27:00 > 0:27:02Climbing over their prey,
0:27:02 > 0:27:08they secrete digestive juices that turn the inside of the coral to liquid.
0:27:08 > 0:27:11Then they suck out the nutrients,
0:27:11 > 0:27:15leaving nothing behind but a ghostly skeleton.
0:27:19 > 0:27:24In only a few days, they can kill huge swathes of the reef.
0:27:35 > 0:27:39Fortunately, coral has an unlikely ally...
0:27:41 > 0:27:44..the Triton's trumpet.
0:27:54 > 0:27:58Believe it or not, this is a predator on the prowl...
0:28:05 > 0:28:11..its killer pounce revealed only when time is speeded up.
0:28:18 > 0:28:20An unlikely hero, perhaps.
0:28:20 > 0:28:26But the Triton's trumpet is an invaluable control on these starfish.
0:28:28 > 0:28:32And the crown-of-thorns isn't the only coral killer on the reef.
0:28:34 > 0:28:38The razor-sharp beaks of bumphead parrotfish
0:28:38 > 0:28:42also put a dent in this living landscape.
0:28:48 > 0:28:51A single fish can chew its way through
0:28:51 > 0:28:55a staggering five tonnes of coral a year.
0:29:04 > 0:29:10Smaller parrotfish, colourful cousins of the bumphead, are also at it.
0:29:15 > 0:29:17But they all give a little back...
0:29:18 > 0:29:21..as the ground-up coral comes out as sand.
0:29:25 > 0:29:29This is island building of a different kind.
0:29:31 > 0:29:34So some of the Pacific's most elegant beaches
0:29:34 > 0:29:37have sprung from a less than stylish birth.
0:29:42 > 0:29:46Above the water, time seems to stand still.
0:29:46 > 0:29:50But the Pacific islands are always changing...
0:29:50 > 0:29:52if slowly.
0:29:55 > 0:29:57This is Bora Bora...
0:29:59 > 0:30:03..a volcano in what could be called "late middle age".
0:30:03 > 0:30:06The sloping flanks have slipped further into the sea,
0:30:06 > 0:30:09pushing the reef away from the shore.
0:30:11 > 0:30:13A lagoon is formed.
0:30:14 > 0:30:18It's a patchwork of coral outcrops and sand.
0:30:24 > 0:30:27Protected from the powerful waves of the surrounding ocean,
0:30:27 > 0:30:33all kinds of animals take refuge in these calm, shallow waters.
0:30:47 > 0:30:50Some take comfort in their bold appearance.
0:30:52 > 0:30:55But others take shelter in the coral.
0:30:57 > 0:31:02Such as these sedentary and appropriately named Christmas tree worms,
0:31:02 > 0:31:06filtering food from the gentle currents.
0:31:09 > 0:31:14For many, entire lives are played out within the clumps of coral.
0:31:19 > 0:31:21Mandarin fish.
0:31:21 > 0:31:24A dozen of them may inhabit one outcrop.
0:31:24 > 0:31:27Males are always on the hunt for a mate.
0:31:27 > 0:31:30And competition is fierce.
0:31:31 > 0:31:34Disputes start with a polite warning.
0:31:34 > 0:31:39The rising dorsal fin is a clear signal to back off.
0:31:41 > 0:31:45But sometimes, going for the jugular is the only way.
0:32:09 > 0:32:14The fight over, it's time to get down to business.
0:32:16 > 0:32:18Spawning is a brief affair.
0:32:20 > 0:32:23Then the eggs are left to the mercy of the current.
0:32:26 > 0:32:32Life in the lagoon depends on a daily flushing of water from the open ocean.
0:32:34 > 0:32:38This flows in through channels formed by natural gaps in the reef.
0:32:41 > 0:32:45With each changing tide, a soupy river of debris and nutrients
0:32:45 > 0:32:49flows out of the lagoon and into the blue.
0:32:53 > 0:32:56This attracts all sorts of life.
0:33:03 > 0:33:05One regular visitor to the channels
0:33:05 > 0:33:08is the gently gliding manta ray.
0:33:14 > 0:33:18It filters out minute creatures floating in the currents.
0:33:37 > 0:33:39But there's more than enough to go around.
0:34:04 > 0:34:07Schools of snapper take the lead...
0:34:13 > 0:34:16..while a wall of fusiliers mops up the remains.
0:35:06 > 0:35:08Across the South Pacific,
0:35:08 > 0:35:13time continues to work its magic on rock.
0:35:15 > 0:35:19Millions of years of erosion and sinking have reduced
0:35:19 > 0:35:23the volcanic mount of Maupiti to little more than a hill.
0:35:28 > 0:35:30Eventually, this hill will disappear too.
0:35:30 > 0:35:34And when it does, it will look like this...
0:35:36 > 0:35:40..Mataiva, a coral atoll.
0:35:42 > 0:35:48Rising above the waves, a coral atoll's reef surrounds a shallow lagoon.
0:35:52 > 0:35:57Where there was once a mighty peak, now there is only water.
0:36:05 > 0:36:09There are thousands of atolls like Mataiva dotted around the South Pacific,
0:36:09 > 0:36:14their size and shape determined by the original volcano.
0:36:30 > 0:36:34Some atolls are round, their rings unbroken...
0:36:37 > 0:36:40..while others have been bent out of shape
0:36:40 > 0:36:42by ocean currents and earthquakes.
0:36:51 > 0:36:55And a few span huge distances,
0:36:55 > 0:37:00a testament to volcanoes whose size and power were once truly colossal.
0:37:06 > 0:37:09Rangiroa in French Polynesia.
0:37:10 > 0:37:12Over 30 miles wide,
0:37:12 > 0:37:16its lagoon is so large that if you were floating in its centre,
0:37:16 > 0:37:19you wouldn't see land in any direction.
0:37:25 > 0:37:27The story of land building in the South Pacific
0:37:27 > 0:37:29may start with volcanic eruptions...
0:37:31 > 0:37:33..but it doesn't end there.
0:37:33 > 0:37:38A volcano once formed an island here, but it sank back below the surface.
0:37:38 > 0:37:41Now it's on the rise again.
0:37:49 > 0:37:53This is the extraordinary Kingman Reef.
0:38:05 > 0:38:08Over 3,000 miles from the nearest continent,
0:38:08 > 0:38:12it is one of the last pristine coral reefs left in the world.
0:38:17 > 0:38:21As tourism and fishing are banned here,
0:38:21 > 0:38:23the reef is about as close as you'll get
0:38:23 > 0:38:26to the Pacific as it used to be, before humans arrived.
0:38:41 > 0:38:45Part of what makes Kingman extraordinary
0:38:45 > 0:38:47is the 200 types of coral found here.
0:38:50 > 0:38:52But there's also something else.
0:38:53 > 0:38:56And it's helping to build the reef.
0:38:58 > 0:38:59Giant clams...
0:38:59 > 0:39:01everywhere.
0:39:04 > 0:39:07More than you'll see on any other reef in the world.
0:39:25 > 0:39:31When giant clams spawn, they expel millions of eggs into the water.
0:39:32 > 0:39:36And when one starts, all the others quickly follow.
0:39:39 > 0:39:42The sea soon turns cloudy... with life.
0:40:20 > 0:40:23Giant clams can live for over 50 years.
0:40:23 > 0:40:29But it's their death that is crucial to the creation of land in Kingman Reef.
0:40:32 > 0:40:36These few hundred metres of coral rubble and dead clams
0:40:36 > 0:40:40are the only visible signs of Kingman above the water...
0:40:41 > 0:40:45..providing a valuable rest stop to passing voyagers.
0:40:50 > 0:40:54Eventually, seeds brought by ocean currents and birds
0:40:54 > 0:40:57will turn it into a new island.
0:41:08 > 0:41:10And once vegetation is established,
0:41:10 > 0:41:12wildlife is never far behind.
0:41:19 > 0:41:23Being good long-distance travellers,
0:41:23 > 0:41:26fairy terns island-hopped their way here to French Polynesia.
0:41:28 > 0:41:31The ancestors of these blue lorikeets, however,
0:41:31 > 0:41:34were brought here by some of the earliest Polynesians.
0:41:38 > 0:41:43It could be described as the ultimate honeymoon destination.
0:41:48 > 0:41:52Though the waters off these shores don't always appear too inviting.
0:41:56 > 0:42:02Blacktip sharks have adapted to swim in less than a foot of water.
0:42:02 > 0:42:07They come to these shallows to hunt for smaller fish.
0:42:23 > 0:42:27Like Kingman Reef, all signs of these islands' volcanic past
0:42:27 > 0:42:29have long since disappeared.
0:42:29 > 0:42:33But without it, land could never have got started here.
0:42:39 > 0:42:42In the very west of the Pacific, however,
0:42:42 > 0:42:45volcanoes have had a helping hand.
0:42:55 > 0:42:59Palau - the jewel of Micronesia.
0:43:03 > 0:43:09As with many islands in the Pacific, its volcanic peaks still linger on.
0:43:12 > 0:43:15Beyond their shores are other familiar scenes...
0:43:17 > 0:43:18..barrier reefs...
0:43:20 > 0:43:23..and small coral atolls.
0:43:28 > 0:43:30But here, there's something different.
0:43:30 > 0:43:34The reefs of Palau have risen from the deep
0:43:34 > 0:43:38not slowly, like Kingman, but suddenly.
0:43:42 > 0:43:4835 million years ago, powerful earthquakes forced them high above the waves.
0:43:49 > 0:43:53And Palau's rock islands were created.
0:43:56 > 0:43:58Some are up to 200 metres tall.
0:44:02 > 0:44:06Exposed cliffs now reveal their rock's true origins.
0:44:07 > 0:44:12It's limestone, created by crushed coral and ancient shells.
0:44:16 > 0:44:21Since those earthquakes, there's been another big change here.
0:44:22 > 0:44:25At the end of the last ice age,
0:44:25 > 0:44:30large areas of this landscape became flooded as the ice melted.
0:44:31 > 0:44:36In the process, over 70 marine lakes were created.
0:44:41 > 0:44:44Cut off from the outside world,
0:44:44 > 0:44:47these lakes produced some unique animals.
0:44:47 > 0:44:52One of these was an ocean predator with long tentacles.
0:44:52 > 0:44:57But here, it evolved into a harmless, graceful wanderer.
0:45:01 > 0:45:05Jellyfish normally feed on small fish.
0:45:05 > 0:45:08But in the lakes, there was little prey.
0:45:11 > 0:45:18So their bells have become a home to millions of tiny photosynthesising algae.
0:45:22 > 0:45:27When exposed to sunlight, these algae produce sugars,
0:45:27 > 0:45:32which in turn provide their hosts, the jellyfish, with food.
0:45:37 > 0:45:42Now, each day, the jellyfish migrate across the lake,
0:45:42 > 0:45:44following the arc of the sun.
0:45:51 > 0:45:56Their only obstacle, the occasional anemone that tries to catch them
0:45:56 > 0:45:57as they float past.
0:46:02 > 0:46:05And sometimes fails.
0:46:12 > 0:46:17So with little danger, and a never-ending supply of food,
0:46:17 > 0:46:20the jellyfish have multiplied...
0:46:25 > 0:46:28..and multiplied...
0:46:36 > 0:46:38..and multiplied.
0:46:55 > 0:47:01It's strange to think that Palau was once just a piece of endless ocean.
0:47:04 > 0:47:06But nothing lasts for ever.
0:47:12 > 0:47:15The never-ending rise and fall of land in the Pacific
0:47:15 > 0:47:20will continue to produce strange and wonderful worlds like these.
0:47:32 > 0:47:37At the start of it all will always be the incredible natural force
0:47:37 > 0:47:40that created land here in the first place...
0:47:41 > 0:47:44..the ocean volcano.
0:48:07 > 0:48:09During the making of this series,
0:48:09 > 0:48:13the team filmed in many remote locations across the South Pacific.
0:48:14 > 0:48:19These isolated islands are home to some truly unique wildlife,
0:48:19 > 0:48:22many of them found nowhere else on Earth.
0:48:34 > 0:48:38But life on remote islands comes at a price.
0:48:38 > 0:48:41Any change can be disastrous.
0:48:48 > 0:48:52And this is what the team came face to face with on the Galpagos Islands.
0:48:58 > 0:49:00The Galpagos are very special.
0:49:00 > 0:49:04It was of course these volcanic islands that inspired Darwin.
0:49:04 > 0:49:08And here, there are an astounding number of creatures
0:49:08 > 0:49:11that exist nowhere else in the world.
0:49:17 > 0:49:21One of these unique animals is the Galpagos penguin.
0:49:21 > 0:49:24This is what the team wanted to film.
0:49:28 > 0:49:31Recently, their survival has become increasingly uncertain.
0:49:31 > 0:49:35And the crew knew this could make filming very difficult.
0:49:36 > 0:49:40Fortunately, the cameramen had close ties with the Galpagos.
0:49:40 > 0:49:46Richard Wollocombe worked as a wildlife guide on Galpagos for several years.
0:49:46 > 0:49:51(THEY SPEAK IN SPANISH)
0:49:51 > 0:49:54He was aware of the penguins' problems,
0:49:54 > 0:49:56so this filming trip was a chance to find out more.
0:49:58 > 0:50:01Ironically, it's people's love of the islands
0:50:01 > 0:50:04which has actually caused some of the problems.
0:50:04 > 0:50:07The major problem is the big increase in the amount of tourists going to Galpagos
0:50:07 > 0:50:11has meant that the service industries who supply those tourists
0:50:11 > 0:50:13have increased the amount of products going to the islands
0:50:13 > 0:50:17and those products can contain very damaging species, introduce species,
0:50:17 > 0:50:22which can have huge detrimental impacts on the native flora and fauna.
0:50:23 > 0:50:28Richard hoped to film inside the nests of Galpagos penguins.
0:50:28 > 0:50:31How easy this was going to be, nobody knew.
0:50:36 > 0:50:41Today's penguin population stands at less than 2,000,
0:50:41 > 0:50:44dramatically less than it was 25 years ago.
0:50:46 > 0:50:51Now introduced species are adding extra pressure to the lives of the penguins.
0:50:54 > 0:50:57When Richard arrived, the Galpagos authorities
0:50:57 > 0:51:00were tightening their regulations, and the final filming permission
0:51:00 > 0:51:03was down to a meeting with the National Park in person.
0:51:06 > 0:51:08They've decided to collaborate with our filming.
0:51:08 > 0:51:11And they're really excited we're doing the filming
0:51:11 > 0:51:15because they can collaborate with us with some scientific investigations.
0:51:15 > 0:51:19Few observations had ever been made inside a penguin's nest,
0:51:19 > 0:51:23so filming might reveal some interesting behaviour.
0:51:23 > 0:51:26I'm fascinated because I've never seen it on television or video,
0:51:26 > 0:51:27so it's a first.
0:51:29 > 0:51:32However, filming couldn't start immediately.
0:51:34 > 0:51:38First, Richard's equipment had to be fumigated and placed in a freezer
0:51:38 > 0:51:42to kill off anything living - plant or animal - that was carried in on the plane.
0:51:47 > 0:51:52It's so amazing to see the level of dedication going on here in this job.
0:51:52 > 0:51:55They're going through our equipment with a fine-tooth comb,
0:51:55 > 0:51:57taking absolutely everything apart
0:51:57 > 0:52:00and looking at the finest details.
0:52:02 > 0:52:05The National Park had cause to be concerned.
0:52:05 > 0:52:08Disaster had nearly struck Isabela Island,
0:52:08 > 0:52:11the very place Richard hoped to film the penguins.
0:52:11 > 0:52:17Just a few introduced goats multiplied to a staggering 100,000.
0:52:17 > 0:52:21Their indiscriminate grazing devastated the landscape,
0:52:21 > 0:52:25destroying the shade and food of the unique giant tortoises.
0:52:25 > 0:52:27Something had to be done.
0:52:29 > 0:52:32The government of Ecuador took on the battle,
0:52:32 > 0:52:36and, against all odds, managed to eradicate every goat.
0:52:44 > 0:52:46(GUNSHOTS)
0:52:52 > 0:52:57With the goats gone, the landscape quickly recovered,
0:52:57 > 0:53:01and the population of the island's precious giant tortoises increased.
0:53:07 > 0:53:11The goat invasion did not affect the penguins.
0:53:11 > 0:53:14But the penguins have other pressures,
0:53:14 > 0:53:16and not all man made.
0:53:19 > 0:53:23Galpagos penguins are the most northerly penguins in the world.
0:53:24 > 0:53:29And they can only live here because of the cold, nutrient-rich current,
0:53:29 > 0:53:34flowing all the way from the Antarctic, which supports huge shoals of fish -
0:53:34 > 0:53:35penguin food.
0:53:51 > 0:53:53But just a small change in water temperature
0:53:53 > 0:53:56can dramatically alter this food source.
0:53:56 > 0:53:59And that is exactly what happened.
0:54:05 > 0:54:10In 1982, the strongest ever recorded El Nio hit the islands.
0:54:10 > 0:54:13El Nio, a natural phenomenon,
0:54:13 > 0:54:17brings warm waters which destroys the huge shoals of fish.
0:54:19 > 0:54:22As a result, penguin breeding failed,
0:54:22 > 0:54:25and their population crashed by almost 70%.
0:54:30 > 0:54:32Ahoy, there!
0:54:32 > 0:54:37After 72 hours in the freezer, Richard's film equipment had passed inspection
0:54:37 > 0:54:38and he was ready to set off.
0:54:38 > 0:54:41He was joined by Carolina Larrea Angermeyer,
0:54:41 > 0:54:45a local scientist who had agreed to take Richard
0:54:45 > 0:54:48to a location where she knew penguins regularly nested.
0:54:50 > 0:54:53It would take 16 hours to reach Isabela Island.
0:54:53 > 0:54:56There, they hoped to find the chicks
0:54:56 > 0:55:00hidden in rocky crevices near the shoreline.
0:55:02 > 0:55:05But the search didn't start well.
0:55:09 > 0:55:11RICHARD: What's that?
0:55:11 > 0:55:14A dead penguin. I saw two more over there.
0:55:14 > 0:55:16- Do you think it's a cat? - Probably.
0:55:16 > 0:55:21I'm not sure because it's not very recent, so you cannot really see much of it.
0:55:21 > 0:55:24- There's the wing there. - Yeah, it's the wing there,
0:55:24 > 0:55:28but the rest of the body, you cannot really tell because...
0:55:28 > 0:55:33RICHARD: Man, can you believe that? It's pretty depressing if it was a cat.
0:55:33 > 0:55:36So this is one of the troubles in Galpagos,
0:55:36 > 0:55:38is that we have introduced mammals
0:55:38 > 0:55:41that these animals have not evolved to compete with.
0:55:41 > 0:55:44The search continued.
0:55:44 > 0:55:47But they didn't find any penguin nests at all.
0:55:47 > 0:55:50We still have to check a number of other nests, but, um...
0:55:50 > 0:55:52I don't think we'll get a chance to see penguin chicks here.
0:55:52 > 0:55:57Carolina set up mosquito traps, as there were also fears
0:55:57 > 0:55:59that avian malaria may have reached the islands.
0:55:59 > 0:56:01We might have a bit of a dilemma,
0:56:01 > 0:56:05because what we were expecting to find was life, not death.
0:56:05 > 0:56:08We were expecting to find a new generation of penguins in their nests,
0:56:08 > 0:56:11um, being tended by their parents.
0:56:11 > 0:56:16And it was really a big disappointment to find just dead penguins everywhere.
0:56:18 > 0:56:22Tourism is growing by 10% a year in the Galpagos,
0:56:22 > 0:56:25and with people come invading species.
0:56:25 > 0:56:29It's impossible to apply the strict fumigation regulations
0:56:29 > 0:56:33the filming kit was subject to on the importers and traders.
0:56:33 > 0:56:38Other South Pacific islands, like Hawaii, are fighting the same battle.
0:56:38 > 0:56:42There, an estimated 30 new species arrive every year.
0:56:48 > 0:56:52For several days, Richard and Carolina travelled around the islands
0:56:52 > 0:56:54searching for penguin nests.
0:56:54 > 0:56:56And at last, good news.
0:56:56 > 0:57:01We have got two little babies, two-week-old chicks about this big,
0:57:01 > 0:57:03sitting abandoned on a nest.
0:57:03 > 0:57:07Both parents are out feeding right now to try and ensure their survival.
0:57:07 > 0:57:09(LAUGHING) I'm so happy!
0:57:09 > 0:57:13I'm really relieved, I have to say. I am...
0:57:13 > 0:57:14Phew!
0:57:16 > 0:57:19Richard worked quickly to get the camera in place,
0:57:19 > 0:57:21and all his efforts were rewarded.
0:57:22 > 0:57:25A great view of an adult feeding the chicks.
0:57:29 > 0:57:33And to top that, an unexpected visitor to the nest.
0:57:35 > 0:57:38RICHARD: The chicks didn't like the crab at all.
0:57:38 > 0:57:43Suffice it to say, there was a constant tit-for-tat going on in the nest.
0:57:43 > 0:57:46The crab would go forward and the penguins would bite it.
0:57:46 > 0:57:49Then the crab would recede into the shadows.
0:57:49 > 0:57:52It was really interesting for a while. It looked quite ominous.
0:57:52 > 0:57:55No, it's quite unusual, I think. I don't think that's...
0:57:55 > 0:57:58Certainly no-one in Galpagos has seen
0:57:58 > 0:58:02what goes on in the nests at night-time.
0:58:02 > 0:58:06So this is all very novel, very new and very, very exciting.