Arabian Seas (2017–…): Season 1, Episode 5 - Turtles Legacy - full transcript

The sea turtle is one of the oldest animals on Earth. These ancient mariners pre-date the dinosaurs and have existed for over 100 million years, but now all seven of the surviving species are endangered.

The sea turtle.

One of the oldest animals
on earth.

These ancient mariners
pre-date the dinosaurs.

They've remained
essentially unchanged

for 100 million years.

The seven surviving species

are all now endangered.

Yet here, on the Arabian
Peninsula, thousands gather

at one of the most important
breeding sites in the world.

Females endure hardship...

..and their young face
a heroic fight for life...

as they battle to become
the next generation

of Arabia's sea turtles.



The windswept beaches
of the Sultanate of Oman

provide the dramatic setting

for one of nature's most
enthralling breeding events.

Every year, four of the
world's seven species

of endangered sea turtles
come ashore here

to dig their nests
and lay their eggs.

Cautious females wait just
offshore until the sun sets.

As soon as darkness falls,

the first female emerges
from the waves.

She can spend several hours
at the waterline,

lifting her head
to check for danger,

before starting her journey
up the beach.

Nesting turtles are
discouraged by light.

To capture this intimate
moment of her life

without disturbing her,

the cameras switch
to infra-red,

a light that's invisible
to the turtle.

This is a Green sea turtle.

She hauls herself
up the beach

by moving her large, powerful

front flippers

This helps her
to gain traction

and move her heavy body.

Green sea turtles
commonly weigh in

at around 330 pounds.

In the water,
the sea turtle is graceful.

But on land, without the sea
to support her weight,

moving takes a lot of effort.

Like all sea turtles,

she can only breathe
when she's still.

The motion of her flippers
impinges on her lungs

and interrupts her breathing.

She must take in
a deep breath,

then hold it, in order
to make her next move.

She reaches
the high tide line.

It's safer to lay eggs
beyond this zone,

away from the risk
of the encroaching sea.

She selects her spot
and starts to dig her nest.

She rotates her fore-flippers

and uses her powerful muscles

to force them back through
the sand like shovels.

Again, she must hold
her breath to do this.

She needs to lay her eggs
in soft sand.

But this patch
is too unstable.

Females will abandon
nest sites

if they sense conditions
aren't exactly right.

They may give up altogether,

returning to the sea
without laying their eggs.

But she changes direction,

signaling her determination
to try again.

She's no longer alone.

These beaches are home to one
of the largest concentrations

of breeding Green sea turtles
found anywhere in the world.

The beaches lie on the
north-east tip of Oman

at Ras Al Jinz.

Every year, up to 15,000
female Greens

come here to lay their eggs.

They nest here year-round,

but numbers peak
in June and July,

when hundreds come ashore
each night.

Moonless nights,
like tonight,

provide extra privacy,
and so are the busiest.

The female finds a new place
to start her nest again.

She chooses fresh sand

with no evidence
of previous disturbance.

She rotates her body
to help create

a shallow depression
in the sand to lie in.

Once she's comfortable,

she's ready to start
digging a hole,

using her shorter
back flippers.

A steady stream of would-be
nesters continues to arrive.

But this spot is taken.

Some are digging deeper
than others.

Sand gets everywhere.

But sea turtles can flush it
out of their eyes

using a secretion from a salt
gland under their eyelid.

This gland primarily allows
them to excrete excess salt

from the seawater.

Once she completes
the nest hole,

she begins excavating
the most important part -

the egg chamber.

This requires precision.

One by one, she curls
each back flipper up

into a small shovel

to carefully scoop out the
damp, compact sand beneath.

The egg chamber is shaped
like a tear drop

and can be up to a further
three feet deep.

She rests between movements

to catch her breath
once more.

Tiring from her exertion,

she takes longer breaks in
this final digging phase.

With one last scoop of sand,

the chamber is ready.

The female, now in a deep
trance, lies almost still,

as she begins
to lay her eggs.

Once she enters this phase,
very little will disturb her.

She drops two or three
at a time.

Each egg is just over an inch
in diameter

and covered in mucus.

The shells are soft
and flexible,

so they don't break
on impact.

Here on the beaches
of Ras Al Jinz,

females have been recorded

laying between 100
and 150 eggs a night.

Her back flippers now conceal
the rest of her delivery.

Once she finishes, the female
covers the nest with sand.

This prevents her precious
clutch from drying out,

and aims to hide them
from predators.

Arabian foxes
patrol these beaches.

Sea turtle eggs
are a nutritious meal.

Two hours after
arriving on land,

the female starts her journey
back to the sea.

Her role as a parent
ends here.

If her eggs remain hidden
from predators,

they'll hatch in two months.

She will come ashore
up to six times this season,

laying up to 900 eggs
before the summer's out.

After that, it will be
two to five years

before she breeds again.

This multiple nesting
strategy each time

is critical to the sea
turtles' survival.

There will be heavy losses of
eggs and hatchlings to come.

In the early hours
of the morning,

it's easy to see why.

An Arabian red fox
breaks cover.

Foxes are the biggest threat
to sea turtle eggs

on these beaches.

This one scours the shore.

If it smells a nest,
it will dig up the eggs.

Foxes on these beaches
have adapted their diet

to take advantage of the
year-round breeding season.

95 per cent of their diet

is sea turtle eggs
and hatchlings.

This one doesn't smell
the newly-laid eggs,

so is out of luck
this morning.

The rising sunlight
now reveals the extent

of the overnight
comings and goings.

Pathways of sea turtle tracks
litter the beach -

evidence of the multiple
night-time nesters.

From above, it's easy to see
the circular nest,

with its arrival and
departure tracks each side -

a clear indication of a
female's route of the beach

and back again to the sea.

In its more usual habitat,
beneath the waves,

a Green sea turtle moves with
ease as it looks for a meal.

Its weight is supported
in the water.

Its curved fore-flippers act
as both wings and propellers

against the sea current.

The sea turtle uses
almost vertical strokes

as it appears to fly
through the water.

Its shorter, rear flippers
act mainly as rudders,

allowing the turtle
to make sharp turns.

Green sea turtles are
exceptionally streamlined

and are highly efficient

Like all sea turtles,

Greens are long-lived.

They have the slowest
maturity rate

of any sea turtle,

sometimes taking
up to 40 years

to become sexually mature.

This juvenile is at least
five years old,

as it's feeding here
in coastal waters.

It will have spent its early
years in the open ocean.

Young sea turtles
are mostly carnivorous,

eating marine invertebrates.

As Green sea turtles grow up,
their diet changes

and they move into these
shallow coastal waters
to feed,

where they become vegetarian,

feeding on seagrass,
kelp and algae,

making adult Greens the only
herbivorous sea turtles

in the world.

This juvenile tugs at carpets
of algae on the hard coral.

Its serrated jaw enables it
to clip and chew plants.

Oman's coast provides plenty
of feeding opportunities.

Seagrass meadows
lie off the central coast.

Algae-rich coral reefs
lie to the north and south.

A sea turtle's shell
is made of keratin,

the same substance as human
hair and fingernails.

It's also known
as a carapace.

And each species
has a distinctive pattern.

In Greens, five scutes, or
plates, run down the center,

with four more
on either side.

The scutes fuse together
over the bony shell,

which provides
a protective shield.

This effective defense

means turtles more than
two years old

have few predators
in the ocean.

Their greatest threat
is from human activity.

Hunting and entrapment
in fishing gear

are perils in the sea.

Dangers on land are from
people harvesting eggs

and destruction
of nesting beaches.

Greens aren't the only
sea turtles

feasting in these waters.

Nearby, a critically
endangered Hawksbill

scours the same reef.

Fully grown, this Hawksbill
is smaller than a Green.

It's most easily identified
by its raptor-like beak,

that gives it its name.

Unlike the Greens,

Hawksbills remain omnivorous
throughout their lives.

A favorite food is sponges.

But they will look for other
marine animals to eat.

This one settles on a tasty
patch of Octocoral,

so called for its eight
hollow tentacles.

It uses its beak
to bite off chunks of coral,

which it crushes
in its powerful jaws.

Hawksbills and Greens are
just two of the four species

of endangered sea turtles
that breed here in Oman,

making the country's beaches

one of the most important
nesting sites in the world.

The juvenile Green sea turtle
now has company.

Despite being
mostly solitary,

aggregations of juveniles

are not uncommon
in prime feeding grounds.

Like all reptiles,

the sea turtle breathes air
through a pair of lungs,

so it must head to the
surface to breathe.

How often they come up

depends on how active
they need to be.

Sea turtles can spend

as little as three per cent
of their time

at the sea surface.

These short bursts of breath

give the Green sea turtle
enough oxygen

to hold it under the water
for up to five hours.

This incredible
breath-holding ability

is largely due to an
extremely slow metabolism.

This enables the sea turtle
to release oxygen very slowly

from large stored reserves
in its blood and muscles.

Their lungs are
specially adapted

to cope with high pressure
under water,

enabling them to dive at
depths of up to 360 feet.

A resting Green sea turtle
can even conserve oxygen

by slowing its heart rate

to just one beat
every nine minutes.

But these active youngsters
show no sign of slowing down.

Along the Ras Al Jinz

strong summer winds
cause turbulence

in the Arabian Sea.

Concealed amongst the waves,

a sea turtle appears
at the surface.

This is not one turtle...

..but two.

A male has hold of a female.

Waves batter the couple
as they mate just offshore.

Closer to the beach,

a second pair struggles
to stay together

against the force
of the breaking waves.

The male hooks onto
the female's shell

using a long claw on each
of his fore-flippers.

As he desperately tries
to cling on,

the claws may inflict damage

to the soft flesh
around the female's neck.

The pair eventually

either by choice
or by the force of the waves.

The female will mate again
with multiple males

to increase genetic diversity
and for sperm storage.

The females now wait offshore
until darkness falls

and the nocturnal nesting
begins once more.

Further north,
on a handful of smaller

and fox-free beaches,

there's a small stirring
in the sand.

Green sea turtle eggs, laid
60 days ago, are hatching.

Tiny baby sea turtles begin
their short but epic journey

down the beach.

The hatchlings are just
two inches long.

Both Green sea turtles
and Hawksbills

breed on these
northern beaches.

Temperature determines
the hatchling's sex.

Those incubated
in warmer conditions,

often nearer the surface,
tend to be female.

Those developed
in cooler temperatures,

in, say, deeper sand,

tend to be male.

This is known as temperature
dependent sex determination

and is common to sea turtles,
crocodiles and some lizards.

Unlike their mothers,

baby sea turtles alternate
left and right flippers,

moving diagonally-opposite
limbs together

to propel themselves
over the sand.

There may be many obstacles
to overcome...

..small pebbles
on the sand...

..giant boulders.

As they reach the smooth,
wet sand,

they pick up their pace.

The vulnerable hatchlings

head to the water,

guided by the light
reflecting on the waves

and the slope of the beach.

Sea turtles usually emerge
at night

to reduce their exposure
to potential danger.

With no land predators
on these beaches,

the youngsters risk it
in the late afternoon light.

This is an extremely
rare sight.

The first plucky adventurers
reach the water.

This baby sea turtle
must now swim for its life.

Frantic flipper movements,
known as a swimming frenzy,

move it rapidly away

from the dangers of
shallow water predators.

Where these hatchlings
go next is still a mystery.

Somewhere out
in the open ocean.

Females that survive
to adulthood

will eventually return
to the beaches

they were born on to nest.

Back on the southern
nesting beaches,

hatchlings have a far more
perilous journey ahead.

Armies of Ghost crabs
patrol this shore.

They're the fastest
crustacean on land,

moving at up to seven feet
a second.

Foxes aside, they pose
the greatest danger

to baby sea turtles.

They get their name Ghost
from their pale color

and their ability
to vanish in an instant.

The crabs can tunnel
through the sand,

breaking into turtle nests
to raid the eggs,

but are at their most

when the hatchlings emerge.

Crabs will snatch up
a hatchling

with their large claws.

Some will then drag
their hapless victims

into their burrows.

Gulls will be ready for any
latecomers in the morning.

The scene is set for a battle
between predator and prey.

As darkness falls,

the females continue to come
ashore to lay more eggs.

Even in low season,

up to 30 can make this
important journey each night.

As they lumber up the beach
to dig new nests,

life is emerging from eggs
laid two months earlier.

Hatchlings often stay
buried under the sand

for several days

before clawing their way
to the surface.

This tiny pioneer
scrambles rapidly

towards the moonlight
reflected on the waves.

But a minefield of danger
awaits him.

The two-inch crabs

will easily grab a hatchling
their own size.

The plucky baby sea turtle
evades the first.

But it's still several feet
from the water.

Finally, success.

Others begin their own
treacherous journeys

to the sea.

Some get a lucky break.

Others are not as fortunate.

Dodging death-traps can be
a matter of luck

more than judgement.

The crabs appear
to be winning.

They devour their hapless
victims alive.

The odds appear overwhelming.

But hatchling survival
is a numbers game.

With up to 150 tiny
sea turtles per nest,

more scramble to the sea

than can be scooped up
by hungry crabs.

A final hatchling embarks
on its mad dash to the water.

Its brief taste of life
seems over in an instant.

But this little guy
is a fighter.

For those that make it
this far,

their perilous journey
is only just beginning.

As dawn breaks,

the hatchlings
have all but vanished.

A gull picks off an unlucky
young straggler.

The last of the night's
nesting females

are also departing.

Those that have laid
all their eggs

will start to migrate back
to their feeding grounds.

Many will head to other areas
around the Arabian Peninsula.

Some will travel as far
as Africa, or the Maldives.

One latecomer
is still hard at it.

She's laid her eggs but she
still has to hide them.

With so many dangers
facing her offspring,

this female takes extra time

to cover her tracks
in daylight.

Females can spend
up to two hours

disguising the nest
from land predators.

A flesh wound
beneath her shell

is likely an injury sustained
whilst mating offshore.

But it will heal soon enough.

This may be her last nest
of the season.

A final clutch of eggs
among a possible 900

she could have laid
this year.

Not all will hatch.

And of those that do,
on these beaches,

less than one in 1,000
will make it to adulthood.

This female was one
of the lucky ones

who survived her inaugural
mad dash for the ocean,

and many years at sea since.

She was born on this beach.

Returning here to nest makes
her at least 20 years old.

For years, scientists
were mystified

about how sea turtles are
able to find their way back

to their natal beaches.

Some travel over 1,500 miles.

Recent research reveals
that sea turtle hatchlings

may use tiny magnetic
particles in their brain

to imprint on the magnetic

around the beach
they're born on.

They may use
this unique signature

to find their way back
as adults.

If a nest site worked
for her mother,

it will probably work
for her.

90 per cent of Oman's
female Green sea turtles

lay their eggs on the beaches
around Ras Al Jinz.

This mother's efforts,

and those of all
the nesting females,

mean they have done
as much as they can

to secure the legacy

of Arabia's
Green sea turtles.