All language subtitles for (scene-rls.net) 03 Wildest Places (2019)

(dramatic music)

- [Kevin] It covers a third
of the world's surface.

(dramatic music)

Ringed by fire,

constantly reshaped by the almighty clash

of Earth's tectonic plates.

(dramatic music)

Creating lifeforms that, in turn,

become the architects
of underwater empires.

(dramatic music)

Here, the world's most primitive lifeforms

have outlived dinosaurs.

And found astonishing
ways to adapt and survive

in one of the most competitive
environments on the planet.

(dramatic music)

This is the Wildest Pacific.

(waves crashing)

(dramatic music)

Coral reefs are the most bio diverse areas

of the Pacific ecosystems.

Bio diversity is the number
of plants and animals

living together in one area.

More than a quarter of
the world's marine species

live on reefs, even though they make up

less than 2% of the surface area.

There are many types of reef systems.

The predominant three are fringing reef

which grows directly from the shore.

When reef has grown out
from a volcanic island

that, over millions of years, collapses,

it forms a ring of reef called an atoll,

a barrier reef runs parallel to coastline,

separated by lagoons.

A single barrier reef can
sit off shore from an island,

or it can be a long network of reefs,

forming vast chains
thousands of kilometers long.

The largest barrier
reef on Earth is so big

it can be seen from space.

It runs parallel to the coastline

of Northeastern Australia,

this is the Great Barrier Reef.

A chain of 3,000 individual
reefs and some 900 islands,

this systems is greater in
size than the United Kingdom,

Holland and Switzerland combined.

This living superstructure is
so significant to the world,

it's deemed one of its
seven natural wonders.

The Great Barrier Reef is a marine creche

for tiny camouflagers

and apex predators.

A place where life flows to
defend itself in curious ways.

And where migrators from across the world

undertake oceanic
odyssey's to return home.

(dramatic music)

(light music)

Reef life begins with the delivery

of the tiniest of parcels,
near millimeters across.

Once a year on a night after a full moon,

a mysteriously choreographed
event takes place.

Coral polyps mouths widen
within precious bundles

of egg and sperm.

Cued by the lunar cycle,
weather, and water conditions

these corals have determined
tonight is the night

to release their genetic
hope into the Pacific Ocean.

Though coral polyps replicate themselves

to colonize an immediate area
to migrate further afield,

they also synchronize a
mass release in this way.

Entire reef site enveloped
by a midnight blizzard.

Yellow, red, blue, and
orange bundles slowly rise

to the waters surface.

The gametes have only a few hours to live.

In that short time,

they must find each
other to spark into life.

When the coral egg and sperm join together

as an embryo, they continue
to drift in currents

developing into a coral
larva, called a planula.

No larger then a grain of rice,

the planulae will wind
their way across other reefs

and lagoons for days, even weeks,

before sinking down to the ocean floor.

A small rock surface is
enough for a larvae to attach

and develop into a coral polyp.

The multiplication begins
and a new patch of reef

grows into the sunlight.

The annual coral spawning is a ritual

that has been taking place
off the Australian Coastline

for tens of thousands of years.

Here, these tiny bundles have created

the largest living network
of reef on the planet.

The Great Barrier Reef
is built on the remains

of an immense mountain system,

The Great Dividing Range.

This` chain of mountains
extends along the full length

of Australia's Eastern Coast,

some three and a half thousand kilometers.

Coral began to claim its kingdom

at the base of the range
around 10 to 20,000 years ago,

after the end of the most recent ice age.

Sea levels began to rapidly rise,

some estimate by meters each year

and with it mountains became islands.

Coral empires rose up where
ancient forests once stood.

The barrier reef is so long,

it spans 14 degrees of latitude.

The warmth and abundant food sources

bring long distance travelers,

like humpback whales.

Each winter they arrive at
the reef's Southern outskirts,

midway through one of the longest

mammal migrations on the planet.

It's a 5,000 kilometer journey
from their feeding grounds

in the Antarctic.

The whales have come here
for the warmth and protection

of the Great Barrier Reef.

They travel north ensure
of the reef system

along the coastline.

These waters are one of
the worlds most significant

whale birthing areas.

More then 20,000 humpbacks
come here each year.

The newborn calves wouldn't be able

to survive the icy polar waters.

After giving birth in the warmer climates,

the whales stay for the winter,

fattening their calves on milk

and teaching them to be cautious.

The return journey south will be perilous.

When they leave the safety of the reefs,

the cold water will
bring great white sharks

and Orcas on the lookout
for vulnerable juveniles.

The Great Barrier Reef network

has an average depth of 35 meters.

On the oceanic side of the system,

beyond Australia's continental shelf

where the Great Dividing
Range once stopped,

is a sudden and steep drop.

In some places of several hundred meters.

The oceanic side of the reef
network is locally called,

"the hard line".

At these steep walls,
the reef earns its name.

It acts as a barrier,
protecting the coastline

from the powerful energy of waves

that have traveled thousands of kilometers

across the Pacific.

Here, hardy brain and boulder corals

are the reefs sentinels,

taking the brunt of the incoming energy.

A green turtle finally
meets the reef's edge,

where she bumps into another.

She too has had a long journey,
several hundred kilometers.

Like all turtles, she's following
an internal homing beacon

to return to the very
beach she was born on.

She's undertaken this journey
every two or three years

since reaching adulthood.

Her home beach lies on a small island cay

at the Southern most tip
of the Great Barrier Reef.

She has many reef crests and lagoons

to cross to reach her birth place,

but first, a weather and rest.

The open ocean has
offered few landing places

and even fewer feeding opportunities.

For this herbivore, the
alkaline floor provides both.

Currents bring nutrients to the walls

of the outer reef edges.

The nutrients bring smaller fish.

And those fish bring predators.

Reef sharks sit atop the
current awaiting easy targets.

Dogtooth tuna have barrel shaped bodies,

weighing well over 100 kilograms,

and are streamlined for speed

with sprints of 80 kilometers an hour.

Barracuda have a row of razor sharp teeth

that angle backward to grip prey.

All have learned to hunt in packs.

Aware of their precarious
position in the food chain,

the smaller fish have
learned to communicate

in astonishing unison to
school up for protection.

(light music)

A fish decides where and how to move

depending on its
whereabouts in the school.

If the fish behind gets within
a couple of body lengths

it speeds up.

If it gets to close to the
one in front, it slows down.

Schooling fish watch one another.

But, they can also feel the
waves their neighbors make

as they swim using
pressure sensitive pores

along their body called lateral lines.

Arriving at the great barrier wall

is like reaching the outskirts
of a bustling metropolis.

Painted clown fish in their anemone homes

tend to their tiny eggs.

One of the reef's largest
residents is the humphead wrasse.

It reaches nearly two meters long

and up to 180 kilograms in weight.

The imposing fish is territorial,

so will be one of the first

to inspect new arrivals to the reef wall,

but tend to be more
inquisitive then aggressive.

(orchestral music)

At the walls deeper areas,
soft corals take hold.

Here, they flourish away
from the buffeting waves

and feed from the nutrient
swirl falling from above.

Soft corals are octocorals.

Unlike limestone building coral polyps

that have six arms, these
soft corals have eight,

and grow without the support of a casing.

Though not reef builders,

some species exclusively
prefer to live amongst them.

Gorgonians, or sea fans, are an octocoral

that can live over a hundred years.

They grow across the current
to net and feed on plankton

drifting by.

Within its ancient arms,

a tiny creature lives out
its entire adult existence,

this is a pygmy seahorse.

Fully grown, it could fit on a fingernail.

A pygmy seahorse drifts
as planktonic brown larvae

until it settles on a gorgonian.

Once in its host, it grows
in a astonishing way.

This seahorse's color isn't
predetermined by genes,

but by the species of
gorgonian it falls into.

If a pygmy seahorse falls
into a purple sea fan,

it will turn purple.

One living in a red and
white species will grow

into those colors and
even sprout knobby skin

for a better match.

This extraordinary adaption ensures

such a small vulnerable animal

is hidden well enough to survive.

Though one of the worlds
smallest fish when born,

the pygmy's young have
the highest survival rates

of all seahorses.

Another soft coral mimic is
the juvenile rockmover wrasse.

It's brown feathery spines and
tumbling swimming technique

imitates a soft coral
caught in the current.

As it grows stronger,
this wrasse will graduate

to the stony coral gardens above.

Here, hard corals harbor
zooxanthellae algae,

which are the tiny
organisms within the polyps

that give the Great Barrier Reef

its stunning array of color.

Many of the harder boulder
and brain corals are decorated

with even more color, in the
form of Christmas tree worms.

These multi-hued spirals
unfold from the coral in pairs.

That's because their twin antennae

of a long soft bodied worm living inside.

Like the complex tree root
systems of a large forest,

vast networks of Christmas tree worms,

colonize these coral heads
in calcium carbonate tombs.

Atop, the crown serve is
gills to absorb oxygen

and as filters to catch
passing phytoplankton

that slides down the
spirals and feeds the worm.

Here, they can live for several decades,

the coral ever growing
in size around them.

The outer wall of these reefs,
levels into a reef crest.

The crest is the highest point of a reef.

It can span out in a long
plate-like formation,

roughly three to 50 meters across.

This is the busiest hub
of a reef ecosystem.

At high tide, large fish
and sharks cruise in

from the open ocean taking advantage

of the buffet on offer below.

Strong branching corals
grow in dense thickets

to help withstand the
constant wave action.

Staghorn is a fast growing species,

gaining up to 20 centimeters each year.

The multi-hued algae
within the tiny polyps

give these staghorn gardens
their stunning color palate.

(light music)

The closely interlocking
framework is an idea hiding spot

for smaller barrier reef fish,

striped humbugs, envious,
and blue-green chromis.

Chromis graze above the reef crest

in thick shimmering clouds.

With protruding jaws that can
extend beyond their mouths,

like a small pipette,

they suck the algae from staghorn polyps.

Chromis also use their
powerful pounce to kiss,

or so it would seem.

These chromis are males, the
lip locking is a showdown,

like a brief arm wrestle,

it's a square off to
sort out the hierarchy.

Staghorns and other hard crest
corals have another predator,

one far more devastating.

It's the crown-of-thorns, starfish.

This starfish reaches three
quarters of a meter in diameter.

It can grow more then 20 arms,

each covered in venomous spines.

(dramatic music)

The crown-of-thorns is a carnivore.

An animal that feasts almost
solely on coral polyps.

It feeds by injecting its
stomach onto the reef.

Then uses enzymes to
digest and suck the polyps

out of their limestone casings.

(dramatic music)

When the starfish moves
on, it leaves nothing more

then the corals white skeleton behind.

(dramatic music)

These starfish are fast and veracious.

In numbers they can decimate
a small patch of coral

in mere hours.

They are prolific breeders,

each starfish can produce
60 million eggs in a season.

Population outbreaks every
few years decimate kilometers

of the barrier reef in just a few months.

Crown-of-thorn starfish

have a particularly keen sense of smell.

There is one scent that will spur them

to move away as fast as they can.

It's the smell of a triton snail.

One of the largest marine
snails in the world.

The triton can grow up
to half a meter long.

It too has a highly
evolved sense of smell.

It can detect the
crown-of-thorn starfish, nearby.

It's a slow hunt, but a relentless one.

The triton snail is seemingly
immune to the toxic spines.

(dramatic music)

It over powers the starfish
with its large muscular foot.

The snail then sinks a long
feeding tube called a proboscis

into the crown-of-thorns.

It's tipped with radula teeth,

the entire hunt and consumption

of the sea star lasts
for around four hours.

It's one of the few natural predators

of the crown-of-thorn starfish.

(light music)

The outgoing tide is a queue
for a flurry of activity

on the reef crest.

A trumpet fish is looking
for an easy last bite.

It saddles up to a coral trout.

The trumpet fish employs a sneaky strategy

called shadow stalking.

It closely tailgates and
uses the trout as cover

to plan its own ambush.

(light music)

The hunting party is
ruined for this trout,

it looks for new feeding grounds,

but this hitchhiker is hard to shake.

The outgoing tide forces large predators

to retreat the crest for deeper water.

With fewer carnivores in close range,

surgeonfish amass in a
hurried spalling rush.

Females and a small number of males

swim upward from the group

and hurriedly release gametes
near the water surface.

Many surgeon species
will do this dance daily

on the out going tide in a last minute bid

to carry their genes out to sea

where they have more chance of surviving.

(light music)

The reef crest at low tide

becomes another environment entirely.

The waters retreat leaves a
vast platform of exposed reef

that also leaves animals exposed

to harmful UV rays and desiccation.

Predators know these few
precious hours of low tide,

awful rich pickings.

Waiting birds stalk the
flats, armed with long legs

and lifelike beaks to
fish in the shallows.

For those who can't swim
freely in strong currents,

the inshore tidal pools
are a safer alternative

to the depths.

But to survive, they've had to develop

ingenious defense mechanisms.

There are few escape
routes in the tidal pools.

The stone fish isn't a strong swimmer,

but it is the worlds most venomous fish.

The poisonous spines
don't help capture food,

but they are a very persuasive deterrent

for becoming a meal itself,

if it can be spotted.

(dramatic music)

A blue-ringed octopus will, at least,

grant a potential predator
a curtesy warning.

At roughly the same
weight as a light bulb,

this small shy octopus is one
of the most lethal animals

on the planet.

Its tiny frame harbors a deadly poison.

Relaxed, it could blend
in to any tidal scenery,

but when threatened,
electric blue rings light up

all over the small mollusk skin.

(dramatic music)

In the marine world, this
color display is akin

to throwing on a red hazard light.

It serves as advance notice.

The octopus's glands hold enough venom

to paralyze 10 humans.

It doesn't take much for
a small crab to succumb.

(water gurgling)

Elsewhere in the crest shallows,

harlequin shrimp has something
a little more ambitious

in its sights, or rather antennae.

It detects the scent of
a starfish in the water.

This shrimp feeds almost
exclusively on sea stars.

When its managed to drag
it back to its lair,

it will feast on the starfish for weeks.

The reward will be worth the effort.

An epaulette shark emerges from the coral.

The sinking sun is its cue to feed.

When its much larger cousins
have been forced out seaward,

this shark takes advantage
of a live skeletal structure.

Named for the military like
patches above its pectoral fins,

the epaulette shark has evolved

to wind its way through staghorn thickets.

And to move between
tidal pools, it can walk.

The pectoral and pelvic fin
pairs are strong and splayed.

These sharks can slow their heart rate

to survive on very little
oxygen for up to an hour

to allow it to wait out
the tide in shallow pools.

Here, it shares its space with a relative

that also defies the typical idea

of what a shark should look like.

The name wobbegong is an
indigenous Australian word

for shaggy beard.

Part of the carpet shark family,

few others bear the name more accurately.

Its grown tassels of skin around its jaw

to blend in to the reef shallows.

It has eyes atop of its head
to allow for ambush hunting.

But this shark has a mouth
designed to vacuum in prey

rather then pin it with sharp teeth.

The reef crests often give way

to barrier reef island lagoons.

Usually surrounding a sand cay,

lagoons are a shallow body of water

separated from the deeper
zones by reef and rock.

They often have an entry and
exit channel, granting access.

Gentler water conditions in
these shallow protected areas,

allow nutrients to amass
and corals to flourish.

Lagoons foster some of the most iconic

Great Barrier Reef species,

brilliantly hued parrotfish,

bizarre and intricate sea slugs,

and resident coral trout.

A pair of reef lizard
fish await passing prey.

These are perfectly
designed ambush hunters

modeled to blend into the background

and equipped with sharp needle like teeth

to lock on to the right opportunity.

Longfin bannerfish sweep coral and rock

looking for polyps and worms to pick at.

They're efficiently adept at hovering,

using their pectoral fins to
brake, turn, and even reverse.

They saw past juvenile snapper
peering out from a crevice.

Schooling up in numbers
until they grow big enough

to venture beyond the protective walls.

The white blotch razorfish
is also engineered

for lagoon life.

It raises a top spine as a
rotor in the calmer waters,

or lowers it to sprint.

It can just as quickly
activate all fins as brakes

until a safe hiding
place is close to hand.

(mysterious music)

This intricately patterned
reef fish is a saddleback toby.

It's a type of puffer fish.

Despite being a smaller bony fish,

these tobies are often
spotted free swimming,

away from the protection
of nearby reef and rock.

It's thought such confidence is bolstered

by their defense mechanism,

their liver and skin
contains a deadly neurotoxin.

These puffer fish have big-like mouths

to pick at small invertebrates and algae,

which they synthesize
into the lethal toxin.

The poison is so strong,

most predators will avoid the fish onsite.

The black saddle filefish is a
completely different species.

It's not at all poisonous,
and is highly nutritious

for large fish and crabs
looking for a meal.

In an astonishing act
of evolutionary mimicry,

this filefish has taken
on the exact markings

of its toxic neighbor,

dots, yellow lines, and black saddles.

It even tries to hover nearby

to share the untouchable status.

It's estimated in every school

of saddleback puffer fish,

about 5% are filefish imitators.

Lagoons are very social areas.

Vast schools in varied
species and size amass.

(mysterious music)

Red-throat and spangled emperors

grow up in mangroves in sea grass beds

before graduating to lagoons.

Here, they shoal together to
forage the reef and floors

for crustaceans and small sea stars.

For others, lagoons
are the starting point.

Schooling is a survival strategy

for these striped catfish juveniles,

at least until they're large enough

to travel beyond the walls.

The young catfish gather in dense balls.

From a distance, they can look

like a single entity swimming about,

sending predators in another direction.

(mysterious music)

They also work as a team
when it comes to feeding.

Striped catfish mouths are
ringed by four pairs of barbels,

fleshy arms that sweep the seabed

for tiny shellfish and worms.

Other fish will often hover
nearby knowing the catfish ball

will fastidiously uncover anything hiding

just below the surface.

The front line of the school will forage

and flick up morsels to the rows behind,

they fall back and the next wave

takes on the work at the front.

The school becomes an
efficient fast moving mass,

mowing its way along the seabed.

(mysterious music)

The lagoon seabeds are often lined

with spectacular giant clams.

It's the largest mollusk on Earth,

an enormous animal between
two scallop shells.

These clams can grow
well over a meter long

and weigh more then 200 kilograms.

On the barrier reef, their
often deeply embedded in coral.

It's simply grown around the clam

over its hundred year lifespan.

The animal within slides
out along the shell's edges.

Like coral, it harbors an algae

that helps it harness sunlight.

In the center a siphon,

one tube to breathe,
feed, excrete, and spawn.

(dramatic music)

Another pacific mollusk giant
is the broadclub cuttlefish.

Broadclubs are part of
the Cephalopod family,

mollusks that, for the most part,

discarded their shells long ago.

They have distinctive bright yellow rings

at the lower edges of their eyes,

broad tentacles for capturing prey,

and a centralized pair for
feeding and egg laying.

At 10 kilograms,

the broadclub is the
second largest cuttlefish.

Despite its size, it's
exceptionally adept at hovering

through the water.

This animal shell is on
the inside of its body.

It's called a cuttlebone,
it's highly porous,

and the cuttlefish controls
the gas levels within it

to move up and down.

An undulating skirt around its body,

helps with direction control.

Tonight, a number of
broadclubs are gathered

around a crop of fire coral.

A rare stinging species only
found on the Northern fringes

of the Great Barrier Reef.

A female has a clutch of eggs to deposit.

The stinging coral is a safe nest.

A male hovers nearby,
it wants to protect her

so she can deliver the eggs
he has fertilized to safety.

But other males know it's
also a chance to mate.

A game of chase ensues,
but the stakes are high.

This is the final chance
for their genes to continue.

(intense dramatic music)

Several arrive, sensing opportunity.

(intense dramatic music)

The dominant male chases
the smaller ones away.

Broadclubs have an exceptionally advanced

skin pigment network, it
flashes color to communicate.

The dominant male flashing an angry red.

One section of his skirt
lights up, like a raised fist,

it's the side closest to
the rival he's intimidating.

(intense dramatic music)

The subordinate males back away.

Male or female, none of these
cuttlefish will live long

after reproducing.

With a moments respite, the
female deposits her eggs deep

into the fire coral.

The eggs immediately harden and
firmly attach in their nest.

Tiny cuttlefish begin growing within.

It will be another 40 days
before the juveniles emerge.

They'll be on their own,

but at the very least the toxic fire coral

will help keep the eggs safe until then.

Also meeting in the lagoon
shallows of dawns early light,

green turtles.

This female has wound her
way through the barrier reef

and finally arrived at the
island where she was born

as a hatchling.

She will mate with as
many males as she can

to fertilize the eggs
she has ready to deliver

to their own beach nest.

The males, usually smaller,
hang on for up to 24 hours

until she signals it's
time for them to move on.

She'll soon need to leave the water

to deliver the precious eggs on her own.

A strawberry hermit crab
is also getting ready

to venture topside onto land,

but first a quick change.

Hermit crabs have a soft abdomen,

which requires extra protection.

They seek out the old shells
of mollusks, like sea snails.

This crab has found one
that may be a better fit.

After measuring it up,

it holds its body up out of
the old one and into the new.

It scurries off toward shore.

(mysterious music)

(birds chirping)

(soft music)

These hermit crabs live
most of their lives on land,

but they need seawater nearby
to keep their gills moist.

Unlike most other crabs,

they have joints that
allow them to walk forward.

Strawberry hermit crab communities

can number in the hundreds.

On the Great Barrier Reef,

they have colonized Southern island cays.

There are roughly 300 of these sand cays,

all along the barrier reef system.

Some are barely more then a hint of sand,

others kilometers across.

A sand cay is a small low
island resting on top of a reef.

Cays form in the reefs when
currents push sand on top,

building until they breech surface level.

Eventually, vegetation takes hold

and with it crabs, birds,
reptiles, and mammals,

any life form that can
migrate, move ashore,

or hitch a ride on floating
debris from the mainland.

These small landing pads
become important rookeries,

nesting sites for birds and turtles.

The sand comes from the
reef ecosystem itself,

shells, coral, and skeletons

all breakdown into calcium
carbonate fragments.

It can take thousands
of years for enough sand

to collect on a reef crest
to support vegetation.

The first seeds are sown by birds.

Some use this cays as
stopovers on migration routes.

Others build nests, fish
in the surrounding lagoons,

and live out their entire
lifecycle on one sandy cay.

On this Southern barrier reef island,

a peculiar relationship has developed

between noddy terns
and the resident trees.

Heron Island supports one
of the most significant

nesting sites for black
noddies in the world.

Around a hundred thousand of these terns

make their homes here, amid pisonia trees.

Pisonias produce small sticky seed pods.

The seeds attract insects
and insects attract birds.

With the food source so readily available,

the noddies are inclined to build nests

within the pisonias branches.

It also benefits the pisonia,

the sticky seeds cling
to the terns feathers.

When they travel offshore
to other islands,

the birds fly with the seeds onboard,

and spread the trees to new cays.

Pisonia forest appear
to flourish even more so

when they're nurtured
by the bird droppings

of black noddies.

However, the relationship
isn't always a kind one.

The noddy tern coats at times
become so thick with seeds,

they can no longer fly.

Downy baby terns are
particularly vulnerable.

The birds often die at
the base of the same tree

that has nurtured them.

Their bodies add fertilizer
to nourish the pisonia,

encouraging more seed pods.

The circle of life and death
on this sand island continues.

(birds squawking)

(mysterious music)

It's been a long journey
for the green sea turtles.

They left their feeding
grounds two months ago

to find this very beach.

They've wound their way
from the outer reef walls

through lagoons to shore.

They're tired, and the final act

will be the most exhausting yet.

In the few hours of low tide,

they must find a place to
dig and lay their egg clutch.

On land, 150 kilograms of body and shell

is a heavy load to haul uphill,

across rocks, and tree roots.

The barrier reef is home to a number

of important turtle rookeries
all in its sandy cays.

Competition for space can be fierce.

Other nests are unearthed in the rush.

They need to dig deep
enough to keep the clutch

of more then a hundred
eggs safe from predators,

and warm enough to hatch.

The turtles must beat the incoming tide.

If they don't reenter the
water before it turns again,

the exposed lagoon flats
are too long for them

to traverse in the dry.

Trapped in the sun, they'll parish.

This green turtle is
too tired and too late

to make it all the way up to the beach,

she deposits her eggs anyway.

The eggs won't survive
without a warm sand home,

but island life will make fast work

for the meal left behind.

Others have been more successful,

and make the final
exhausting return to sea.

They've grasped the few hours
they have between tides,

and now their crucial role

in continuing their kind is complete.

They can't stay to defend the
nest or see their young born.

When incoming waves meet the
sand it's their queue to leave.

It's another small window to safety

before the tide turns once more.

(mellow music)

In the new year, in the
Southern summer's later days,

the first of the hatchlings
break free from their shells.

(mellow music)

Hundreds of babies weighing
little more then 25 grams

burst forth from a single nest.

It's a common survival
strategy on the reef,

start with a great number of young

and one may just live long
enough to reach adulthood.

Instinctively, the head to the ocean.

It's a a perilous run in broad daylight.

Birds and crabs are on
the hunt for a quick meal.

When they reach the safety of the sea,

the survival game begins, anew.

Just one in 1,000 of these tiny turtles

will live out the next few
decades and return to this beach.

The cays of Australia's Northeast Coast,

are such valuable nesting sites

due to the protection afforded them

by the Great Barrier Reef.

Barrier reefs shield the coastline

and foster their own ecology.

None on Earth are bigger then this one.

A living structure that spans more then

two and a half thousand kilometers.

The Great Barrier Reef is not only a guard

for the continent it boarders Westward,

but is a nursery for the Eastern ocean.

Currents leave the reef
and travel to the open sea.

The barrier reefs larvae and
seeds are carried far off shore

where they learn to adapt
in new Pacific places.

(dramatic music)