Original subtitles

(light music)

- Every year, extraordinary sharks descend en masse

to a secluded bay on the coast of Australia.

(dramatic music)

Port Jackson sharks share their tranquil waters

with an array of strange and wonderful creatures.

Finding a partner is the name of the game,

risking all in their quest for a mate.

Not all are successful

in their pursuit to add to their bloodline.

New life grows in mystifying eggs,

(thunder cracks)

while storms batter the coast.

The new generation enter the world alone,

and must learn fast in order to survive

amid the bay's many residents.

(exciting drum music)

(waves gently breaking)

(gentle music)

To the south of Australia's sprawling city of Sydney

lies the serene Jervis Bay.

The bay encompasses over a hundred square kilometers

and is surrounded by the world's most pristine white sands.

Part of a national park, the tranquil waters

are protected by the government,

and are teeming with life.

(water gently splashes)

Every winter, mysterious objects are discovered

on the bay's famed sands.

(gentle music)

(waves gently crash)

The 15-centimeter, spiraled-shaped objects

are, in fact, shark eggs.

(gentle piano music)

(gentle harp music)

Susan Newson has been observing the bay's wild residents

for years, and has been captivated by the peculiar eggs.

Diving into the tranquil waters,

she sets out to find the sharks that lay these mystery eggs.

(water splashes)

(gentle music)

It's winter, and the waters are a cool 14 degrees celsius.

Moving deeper into the bay, the environment changes

from white sands to hard rocks, covered in seaweed.

There is in excess of 230 kinds of seaweed

growing from the sea floor.

200 species of fish live amongst the sprawling,

aquatic foliage.

Old wife fish, endemic to Australia,

congregate in the tranquil waters.

The tiny fish school together,

seeking the shelter of the bay's many rocks.

Multiple species gather in the shallows,

ensuring safety in numbers.

(suspenseful musical tone)

At a depth of five meters, a shark appears

from within the seaweed bed.

(light music)

This is what Susan has been searching for,

a Port Jackson shark.

Black banding on the back and sides

are the shark's distinguishing features.

(whimsical violin music)

It's a meter in length, with a large, bull-like head

and slender body.

(Susan exhales)

Relaxed in the presence of humans,

Susan is able to get within inches

of the resting individual.

Port Jacksons belong to the bullhead order of sharks.

These distinctive fish have truly extraordinary mouths.

Their powerful jaws are specialized

in grinding up tough food sources

using sharp teeth at the front

and powerful, crushing molars at the back.

(playful violin music)

With poor eyesight, Port Jackson sharks

rely on their excellent sense of smell to find their prey.

Rather clumsily, they search for mollusks and crustaceans.

As bottom-feeders, much of their time

is spent on the sea floor.

(water current bubbles)

More sharks can be found in shallower parts of the bay.

The abundance of seaweed provides the perfect hiding place.

(gentle music)

Multiple Port Jacksons rest in close proximity,

showing no signs of aggression.

Two objects protrude from the resting shark's pelvic fins.

These are the male's genitalia,

and are known as claspers.

In this patch of the bay,

all the sharks encountered bare the distinctive organs.

It is only males lurking in the shallower waters.

(waves splash)

Females can be found at deeper depths.

(relaxing music)

Their domain is located towards the mouth of the bay,

some 10 kilometers from the shallows.

(waves gently rolling)

(water splashes)

Diving into the deeper waters,

Susan sets out to find the Jervis Bay's

female Port Jackson shark population.

(gentle music)

The landscape is very much different

to the shallower reefs of the males.

Sea tulips sprout from the seabed's rocks.

Swaying in the current, they feed on drifting plankton.

(water current bubbles)

At a depth of 20 meters, sharks begin to appear.

Hundreds of Port Jacksons litter the ocean's floor.

They are all missing the claspers of the males.

(gentle piano music)

These are the bay's females.

They are much larger than the males of the shallow reefs,

and take between 11 and 14 years to reach sexual maturity.

It's not unusual for male and female Port Jackson sharks

to be separated like this.

In fact, this is their natural behavior.

(intriguing music)

Port Jackson sharks spend their summer

in separate groups, near Tasmania.

As winter descends, they travel over 800 kilometers

to Jervis Bay.

The males swim to the shelter of the rocky reefs,

while the females linger in deeper waters.

As the spring tide hits, the females become more active,

gradually swimming into the shallows.

During this period,

the difference between high and low water

is at its greatest.

It can increase by as much as two meters.

(waves gently breaking) (slow beat music)

As the motions of the bay's water change,

so do its residents' behavior.

Male Port Jackson sharks will be waiting

for the females' arrival.

(suspenseful musical tone)

However, it's not only the males lurking in the shallows;

a smooth stingray glides through the tranquil waters.

(gentle up-tempo music)

At four meters long, and weighing a hefty 300 kilos,

it is Australia's largest stingray.

The bay's inhabitants are becoming more active.

Another enormous creature emerges:

a giant Australian cuttlefish -- the world's largest.

Its body can reach up to a meter in length

and weigh over 10 kilos.

Their specialized eyes can see aspects of light

that are invisible to humans.

Gracefully, the highly-evolved mollusk

waves its lateral fins to propel itself through the bay.

This individual is a male.

Effortlessly, he swims into a crevasse.

(intriguing music)

Port Jackson sharks rest within,

and are undisturbed by their unusual visitor.

From the depths of the crevasse, a female appears.

In her rare sight, the pair gently lock tentacles,

and begin to mate.

With a specially modified arm,

the male transfers a capsule of sperm.

(water current rushes)

Port Jackson sharks will also soon get their chance

to extend their bloodlines.

Females are beginning to appear in the shallows.

(bright music)

Swollen bellies indicate they are ready to mate.

More and more females arrive in the shallows.

They start to gather around crevasses.

Finding the most sheltered spot

is the wandering shark's assignment.

Once a suitable crevasse is found, they finally rest.

(gentle piano music)

Now, they will wait for the males to come to them.

(suspenseful musical tone)

Out in the open, males begin their search for a mate.

Using their heightened sense of smell,

they comb the shallows for the scent of a female.

(up-tempo drum music)

One has picked up the aroma of a potential mate.

(acoustic guitar music)

Peering inside the crevasse,

he finds what he's been searching for.

The egg-laden female dwarfs the male,

but he is not overwhelmed by her imposing size.

(intense musical tone)

In what looks like an act of aggression,

the male bites the female's pectoral fin.

(intense music)

She manages to shake off the aggressor.

The apparent act of aggression

is actually a display of courtship.

Males will bite the females' fins

to assess their willingness to mate.

Wriggling free is a clear sign of rejection.

More and more, males begin to inspect the bay's crevasses,

in search for mating partners.

One contains a nasty surprise.

(eerie dramatic music)

A banded wobbegong springs from the darkness.

It is a superbly camouflaged, carnivorous carpet shark.

At three meters in length, it is more than twice the size

of the Port Jackson shark.

It is the perfect ambush predator,

easily able to blend into the bay's seabed.

(suspenseful music)

A careless Port Jackson male

swims right into the predatory wobbegong's path.

But he's lucky this time.

Not all have been so fortunate.

This individual bares the scars of a recent shark attack.

(peaceful music)

Males are willing to risk all in their quest for a mate.

All around the bay, romance is blossoming.

(light cheerful music)

One male makes his move, and latches onto a potential mate.

(gentle music)

Persistence is key.

This female does not wriggle free from the male's grip.

With a firm grasp, he pulls his mate closer.

The claspers are inserted, and mating begins.

(intense music)

Another male tries to take advantage,

rudely cutting in on the couple.

He is rapidly shrugged off,

failing in his bid to cut in on the mating female.

The impatient male will have to wait

for another chance of romance.

The whole saga does not last long,

but the female bares the marks of the rough courtship.

Fortunately, she has thick skin.

These wounds should heal, given time.

(up-tempo violin music)

A freshly fertilized egg will now begin

to develop inside the female's body.

Of the 500 species of shark,

around 70% of them give birth to live pups.

It's only the minority that lay eggs.

Some of the bay's Port Jackson sharks are near to laying,

and begin to search for suitable spawning sites.

With such a precious cargo,

finding the perfect location is paramount.

(water current bubbling)

(water current flowing)

An egg is already protruding.

It will not be long until she lays.

A suitable spot must be found soon,

but she seems reluctant to commit.

Finding the right spot is crucial

for the egg's chances of success,

and decisions cannot be rushed.

(seagulls squawking)

As night draws in, the shark has yet to lay.

(up-tempo intriguing music)

Susan does not want to miss the rare occasion,

and believes there is a higher chance

of discovering a laying shark at night.

(insects chirp)

Diving into the pitch-black depths,

she sets out to find a spawning Port Jackson shark.

The search is focused around the crevasse

the females were examining during the day.

Sure enough, a female on the verge of laying is found.

Restlessly, she swims around the crevasse.

An egg protrudes from her body.

(gentle violin music)

She is ready to lay.

Port Jackson shark eggs take

between 10 to 12 months to hatch.

Finding a safe nesting spot is crucial.

A long, deep crack in the rock

looks like the perfect location.

It would supply the eggs with plenty of shelter

from the ocean's currents.

(gentle piano music)

Happy with the crevasse as a spawning ground,

the female moves into position.

(whimsical music)

Frantically, she shakes her tail into the gap.

This is the moment Susan has been waiting for.

A single spiraled egg drops into the crevasse.

Exhausted, the female swims away.

Her job here is done.

(intriguing music)

The egg rests deep within the rocks.

Newly laid, it is about 15 centimeters long.

There is an ingenious purpose to the exquisite shape.

(cheerful music)

Currents push the egg into the back of the crevasse,

wedging it into a small gap.

Acting like a corkscrew,

it screws itself into the perfect position.

The longer it is in the water, the harder it will become.

Rocky reefs provide perfect nooks and crannies

for the spiraled eggs.

But, not all make it to hatching.

Many are dislodged from unsecure spawning sites.

(waves crashing)

The displaced eggs wash up on the bay's sandy beaches.

(waves crashing)

Other than their unique shape,

they also have an astonishing, tough outer shell.

Susan takes the opportunity

to dissect one of the stranded eggs.

(waves crashing)

- [Susan] These things are tough.

- [Narrator] Even a sharp pair of scissors struggles

to penetrate the protective case.

The thick shell is made up of the same protein, keratin,

found in human hair and nails.

Jelly-like albumen surrounds the yolk.

It takes around 10 months

for the shark to fully develop, and hatch.

(gentle music)

The first stage of development can already be seen.

A well-placed Port Jackson shark egg

will safely develop over time,

tightly packed into crevasses.

Another species of bullhead shark

employs a different tactic.

Their eggs are similar in appearance,

but use tendrils to anchor themselves to the bay's seaweed.

The tiny, developing sharks

only have their tough keratin shell as protection.

(gentle cheerful music)

It is a crested bullhead shark that lays these eggs.

They look almost identical to Port Jacksons,

but lack the Port Jackson's tell-tale lateral banding.

Breeding is at its peak for the bay's sharks in mid August.

Port Jacksons will lay up to 16 times

during the mating season.

(water current bubbles)

Eggs litter the seabed...

drifting in the current, as if they were somehow dislodged.

(water current flowing)

Many of the ruined eggs bare distinct puncture wounds.

They have been predated.

(somber music)

The bay contains many likely suspects.

Some carnivorous fish are of a monstrous size,

like the Eastern blue groper,

reaching over a meter in length.

It has a powerful set of teeth,

adapted to ripping barnacles off rocks.

(up-tempo intriguing music)

Swimming near a Port Jackson shark egg,

it appears the groper could be one of the egg-eaters.

However, it shows little interest.

Many fish swim past the eggs,

but only show a slight curiosity.

The egg's tough outer shell and large size

prevents most fish from being able to feed on them.

A culprit is yet to be found.

(water gently flowing)

One female begins to lay what will be one of the last eggs

of the breeding season.

(shark thrashes)

Twisting her body into the crevasse, she begins to lay.

(intense musical tone)

Unfortunately, it is a failed attempt.

Dislodged from the crevasse, the egg falls to the sea floor.

(somber music)

Drifting in the current, it is dangerously exposed.

An opportunistic male spots the wayward egg.

Swimming over, he claps it in his powerful jaws.

It is not unknown for Port Jackson sharks

to transport their precious eggs,

but this male has something else on his mind.

(up-tempo intriguing music)

He takes the egg away from the safety of the rocks,

carrying it to a secluded sand bed.

(intense music)

Astonishingly, the male begins to bite down.

Repeatedly, it attempts to pierce the tough, keratin shell.

Once penetrated, it sucks out the egg's contents.

Utilizing its specialized jaws,

this male makes short work of the spiraled food.

It's not just a single wayward male;

some will go to great lengths in their pursuit of the eggs.

(shark thrashing)

They will even squeeze into the tightest of gaps

to get to the spiraled snacks.

(water current rushing)

(gentle somber music)

This cannibalistic behavior

is not limited to the males alone.

Female Port Jackson sharks will also resort

to eating their own species' eggs.

It may seem brutal, but the sharks expend a lot of energy

during the mating season.

Eggs provide a valuable food source

during this testing time.

(gentle somber music)

(water current flowing)

However, not all are devoured.

Some are left untouched,

and become brilliantly camouflaged among the bay's rocks.

Marine life has started to grow on the keratin shell.

Susan believes the egg has survived here for almost a year.

(water gently flowing)

Inside the shell, a shark pup must be near to hatching.

A narrow gap in the shell

allows a specialized camera to enter.

(gentle music)

Growing inside, is a tiny Port Jackson shark pup.

(shark bubbles)

Breathing steadily, it is almost ready to hatch.

(waves gently rolling)

(water current flows)

A few days later, Susan searches for the same egg.

(divers breathing, water bubbling)

(light cheerful music)

A tiny head pokes out of the spiraled shell.

The pup is on the verge of fully hatching.

Wriggling with all its might, it is finally freed

into its underwater world.

Its first swim is a little unsteady.

(cheerful orchestral music)

The newly-hatched pup is only 20 centimeters in size.

It soon becomes a more established swimmer,

and heads up to the surface to explore its new world.

The pup's umbilical cord,

that was once connected to the yolk, can still be seen.

(cheerful orchestral music)

This energetic, young shark

seems to have a destination in mind.

(water gently flows)

(motor humming)

Susan heads to the area of the bay

she believes the pup is heading to.

The waters here are particularly calm,

with only a gentle current.

(motor hums, water splashes)

Sea grass stretches in all directions.

Many different species surround the area,

including eelgrass and paddle weed.

(playful music)

Curious creatures live within the aquatic garden.

A tiny pygmy leatherjacket appears.

The miniature fish is only three centimeters in size.

A wide-body piper fish sways in the current,

looking remarkably like the sea grass it lives in.

(playful music)

A year-old Port Jackson pup rests on the sea floor.

There is a reason why it has chosen this location:

the sandy sea grass garden

is teeming with micro life.

(gentle piano music)

A pup scans the floor for food.

It has sensed something in the sand.

On this occasion, the tiny shark

has bitten off more than it can chew.

But, the sands and sea grass are bristling with life.

More opportunities will arise.

It is the perfect place for the sharks to develop.

(water current flows)

For a few years,

the pups will remain in their serene nursery.

(water bubbling)

Deeper in the bay,

an airplane wreckage has been enveloped by the ocean,

and has become an artificial reef.

(light up-tempo music)

Eastern Fortescue, endemic to Australia,

swarm around the wreckage.

The small, 15-centimeter-long fish

have poisonous spines on their back,

and are more commonly known as waspfish.

(light up-tempo music)

A juvenile Port Jackson shark rests among the school.

Similar in color to the waspfish, the pup blends in.

There is safety in numbers,

but they must not let their guard down.

(eerie suspenseful music)

(sharp musical tone)

Something disturbs the fish.

A meter-long Eastern fiddler ray plows into the school.

(up-tempo music)

(fiddler ray thrashes)

The waspfish part way,

but confidently, the shark pup stands its ground.

It appears as if the ray is sizing up the young shark.

Defiantly, the youngster does not budge.

It has something up its sleeve:

a defensive weapon that is enough to deter the ray.

Joined to the joint of the dorsal fin,

protrudes a protective spine.

At its sharpest during the juvenile stage

of the shark's life,

it is enough to deter the would-be predator.

(up-tempo suspenseful music)

Port Jackson sharks enter the world on their own,

with only their dorsal fin spine as defense.

With a lifespan of 40 years,

they spend their first few years in the bay,

before heading out to the open ocean.

(waves crashing)

(thunder rumbles)

As August comes to an end,

low air pressure consumes the bay.

(thunder cracks)

A storm surges across the coast.

(waves crash)

Raging waves smash against the bay's beaches.

(waves crashing, wind blowing)

(birds chirping)

The fierce storm has persisted for three days.

(waves gently break)

Susan walks along the coastline, examining the damage.

Where there was once a white, sandy beach,

there is now a thick covering of seaweed.

The powerful storm surge shifted the aquatic foliage

onto the land.

(gentle music)

Port Jackson eggs are strewn across the beach.

A mere 10% of the sharks will make it to hatching.

Only the most well-placed of eggs will survive.

(water gently splashes, seagulls squawk)

It is the first time Susan has been able to head out

into the bay since the fearsome storm.

She is keen to see how the bay's shark population has fared.

The torn seaweed of the storm obscures visibility.

Finding anything amid the carnage is difficult.

(somber music)

Port Jackson sharks begin to appear in the murky water.

They have weathered the storm,

but the fate of their eggs is unknown.

(up-tempo drum music)

Slowly, the sharks begin to venture out

into the open to feed.

They sift through the sand, looking for stray crustaceans.

Heading further out into the bay, more begin to appear.

Sheltering under rocks,

the sharks avoided the storm's harsh conditions.

(water current flows)

Susan is keen to find their eggs.

With so many washed up on the beach,

have any remained in the bay?

(somber music)

Tightly corkscrewed into the crevasses,

the best-placed eggs have survived the monstrous storm.

(gentle violin music)

It's thanks to the unique spiral shape,

that they have remained intact.

The Port Jackson shark pups have also withstood the storm

in their sea grass nursery.

One in five of the shark pups will make it to adulthood.

As winter comes to an end,

the adult Port Jackson sharks will leave

the tranquil Jervis Bay and head out, once again,

into the open ocean.

They leave behind their spiraled eggs,

safely squeezed into rock crevasses.

Next winter, they will once again return,

and give birth to a new generation.

(uplifting orchestral music)

These extraordinary sharks have made Jervis Bay

a home away from home.

Their time in the tranquil waters is crucial

for both the old

and the young.

Timing is everything in carving out a successful future.

Sometimes, a ruthless edge is required to survive

in the competitive bay.

With their specialized eggs and unique adaptations,

Port Jackson sharks will continue to thrive

in their aquatic realm.

(uplifting orchestral music)

(light music)