Original subtitles

A newly born bottlenose dolphin,

its skin still creased by the tightness of the womb

from which it has only just emerged.

Its mother is devoted to it...

..and will care for it for the next five years.

That is an unusually long time

for any ocean-going animal.

Most marine creatures

simply abandon their young as soon as they appear.

DOLPHINS WHISTLE AND CLICK

But those who care for them

do so in some very remarkable ways.

Coral reefs occupy less than 1%

of the floor of the world's oceans...

..but they provide homes

for over a quarter of all marine species.

Indonesia's reefs are among the most diverse on Earth.

Over 2,000 species of fish live here...

..and most reproduce in the simplest of ways.

Females release their eggs

and the males rush in and fertilise them.

The young are then swept away

and few, if any, will meet their parents again.

But one fish behaves very differently.

The Banggai cardinalfish.

The adults spend most of their time among sea urchins...

..protected to some degree by the urchins' spines.

When a female is ready to spawn,

she leads a male away from the shoal.

She displays to him,

quivering her distended fins.

And then she releases a mass of eggs, which he...

..takes into his mouth.

He hasn't swallowed them.

On the contrary,

he is protecting them.

But for the next four weeks,

he won't be able to eat.

Starvation, however, is the least of his worries.

There are predators around...

..of many kinds.

An unguarded baby fish would be quickly eaten,

so the hatchlings stay inside their father's mouth.

This anemone could provide the male with a home,

for, although its tentacles have stings,

he is immune to them,

but his predators are not.

The resident anemone fish is also immune...

..but this one doesn't welcome strangers.

This anemone, however, seems to have vacancies.

The male picks his moment

to leave the safety of the urchins' spines.

Here, he's not alone.

But this anemonefish doesn't mind sharing.

He has found a new home for his young.

But they seem unwilling to leave his mouth...

..so he gives them a little encouragement.

But there's always one who is reluctant to leave.

Here, among the anemone's tentacles,

they will remain until an urchin appears who has vacancies.

His 30 days of fasting

have given his young an excellent start in life.

But parental responsibilities extend far beyond providing shelter

for the mammals that live around the reef.

DOLPHINS WHISTLE AND CLICK

A bottlenose dolphin mother spends five years

showing her calf the skills necessary for survival.

And she does so through play.

Her lessons start with a trick.

First,

balance a piece of coral on your nose.

Second, take it up to the surface.

Third, drop it.

And then, before it reaches the bottom...

..catch it.

All adults can perform this trick.

Perfecting it is therefore a rite of passage for this calf.

First, balance the coral.

This is not easy.

Try again.

Step one - balance the coral.

Or bite it...

..and skip to step two.

Now...

..catch it.

Got it!

Just in time.

There are also other, more important skills that a calf must learn.

The mother leads her youngster

to one particular kind of coral

that is almost hidden.

One that has a special, extraordinary characteristic.

It produces antifungal chemicals

which dolphins rub on their skin.

These dolphins, remarkably, medicate themselves

and they pass on this knowledge to their young.

Passing on skills such as these

is part of good parenting.

The south coast of Australia.

Here, the shallow sea, for 5,000 miles,

is carpeted by dense seaweed.

These underwater meadows thrive in the cold, turbulent water.

And one remarkable fish has evolved here

and exists nowhere else -

the weedy seadragon.

It's marvellously camouflaged

and an exceptionally dedicated parent.

In spring,

male and female dance together.

They mirror each other's actions.

He seals their bond

by attaching her eggs to his tail.

The eggs are bright pink

and make him dangerously conspicuous.

But within a few weeks,

the eggs become covered by algae...

..and that makes them less obvious.

After six weeks,

his parenting duties come to an end.

The baby dragons begin to hatch.

They're just 2cm long.

Perfect miniatures of their parents.

They share their micro world

with one of the strangest creatures in the seas.

Skeleton shrimps.

They're seldom noticed,

but they live in oceans worldwide.

They're armed with formidable weapons

and they are remarkably attentive parents.

About 25 juveniles cling to their mother

until they're strong enough to grip the seaweed.

She needs to feed them...

..and the best food is at the top of the seaweed.

And that is where she takes them.

Carrying as many young as this

is exhausting.

And if she stops,

she risks everything.

She falls onto an urchin...

..which catches her with its tube feet

and starts transporting her towards its mouth.

But she wriggles free

and resumes her climb.

Skeleton shrimps live in colonies

and compete for the best feeding places.

This looks good...

..and she waits for something edible to drift by.

This mysid is big enough to provide a meal

for the shrimp's entire brood.

Her young clamber over her head

to claim a share.

Once fed, they leave,

giving her a break from the responsibilities of motherhood.

Seaweed, wherever it grows,

provides animals with both food and shelter.

The Shetlands -

the northernmost of the British Isles.

It has the densest population of Eurasian otters in the world.

OTTERS SQUEAK

These three cubs are five months old.

They're still totally dependent on their mother for food.

She finds it in the seaweed...

..where there are great numbers of small fish.

The fish are well camouflaged and not easy to see...

..but she uses her whiskers to feel for them.

Otter mothers usually produce one or two cubs at a time.

Triplets like these are extremely rare,

and each cub needs to eat a quarter of its body weight every day...

..so this mother has to catch a lot of food.

She must also feed well herself

if she's to survive the winter.

The youngsters squabble over every fish.

OTTERS CHIRP AND BARK

The biggest and most vigorous cub

is the first to get food,

and the smallest often goes hungry.

This small male, however,

decides to fish for himself

and joins his mother farther out to sea.

He's caught something.

Unfortunately,

it's something that bites back.

OTTER SQUEALS

It's a crab...

..which is easy to catch, but not very nutritious.

His mother has been too busy to notice...

..that he has strayed...

OTTER SQUEAKS

..and now he is lost.

SQUEAKING CONTINUES

Over a quarter of otter cubs

don't survive their first year...

..many because they lose touch with their mothers.

All he can do is to keep calling.

OTTER BARKS

SQUEAKING

NEARBY BARK

Winter in Shetland is very cold,

and life becomes hard for otters,

both old and young.

The bigger the cubs grow, the more food they need,

and soon she will leave them to find food for themselves.

California's Channel Islands

are surrounded by one of the richest of marine nurseries.

A forest of giant kelp.

This area has now been declared a marine reserve,

where fishing is totally banned.

As a consequence,

over 1,000 different species of animals now live here.

Among them, giant sea bass,

which, elsewhere, are critically endangered.

On the floor of this submarine forest

lives a particularly territorial species.

The Garibaldi.

This male has built his nest in the centre of his territory...

..and here he cultivates a particular kind of red algae.

He carefully prunes it

so that the females can lay their eggs on it.

Several have already done that...

..so now he has a potential brood

of over 150,000.

He devotes his time to keeping the eggs free from algae

and driving off hungry intruders.

Some visitors, however, are so big they're best ignored.

His most dangerous enemy, however,

is, in fact, relatively tiny.

A little blue-banded goby...

..which takes advantage of the constant intruders...

..to steal the Garibaldi's eggs.

But the biggest threat of all comes from the sea urchins.

They eat virtually everything in their path...

..from the nest of a Garibaldi,

to the entire kelp forest.

He does all he can to keep the urchins away.

His neighbours help.

Inside the reserve,

there are enough fish

to keep urchin numbers in check.

But the reserve is tiny.

Outside it,

humans have caught most of the fish

that once kept down urchin numbers.

And that, combined with an ever-warming sea,

has created a plague of urchins

that have devastated the seafloor.

They have destroyed the kelp forests

along great stretches of California's coast...

..and now we ourselves are adding to that damage

by using our seas

as dumping grounds for our waste.

Many animals have changed their parental behaviour

in order to survive in this new world.

Pale octopus are relatively short-lived...

..and this female has just over a year

in which to breed and raise her young.

To do that, she has to find a safe den.

She must choose carefully.

Good dens are rare.

A discarded toilet could perhaps serve...

..but this one is engaged...

..and is already being fought over.

A squirt from its owner's ink sac

makes things clear.

She keeps looking.

Many of the available den sites are too exposed.

She wants somewhere a little more secluded.

This plastic pipe is also occupied...

..by a male.

But he is signalling his readiness to breed.

It's an irresistible performance...

..so she inspects his den.

It may not look like much

but, to her, apparently, it will do.

He nudges her into his home.

She gives his den, and him, her seal of approval

and the two mate.

A few days later,

she starts laying her eggs inside the pipe.

She will eventually produce about 500 of them.

She strokes them with her suckers

to keep them clear of algae.

Her home will hide her...

..and is easy to defend.

But laying her eggs will be the last act of her life.

All octopus mothers die in their dens.

As her eggs hatch,

she takes her young in her arms...

..and uses her siphon to propel them to independence.

In their year-long lives,

13 million tonnes of plastic

will have been dumped onto their ocean homes.

Her final resting place

was the home that she set out to find...

..but perhaps not the grave that anyone might consider appropriate

for such a dedicated parent.

As our seas change,

those species with sufficient intelligence to adapt

are finding new ways to support their offspring.

And there are few sea creatures

more inventive in their search for food

than killer whales.

They're powerful, swift and agile...

..but the key to their success

lies beyond their physicality.

It comes from their sociability

and the way they use their complex relationships to teach one another.

Each family is led by its grandmother,

the matriarch.

She may live into her 80s,

far beyond the age of producing calves of her own.

But her responsibilities as a leader never cease.

She plays a key part in teaching them all how to hunt.

She initiates a chase...

..and the rest of the family join her.

But this is not a game.

One deliberately stops swimming

in order to enable the others to practise a particular skill.

They push it beneath the surface

and submerge its blowhole

to prevent it from breathing.

They are practising the actions they will use to drown their prey...

..and these orca need to be on top of their game.

They hunt the largest animals that have ever lived.

Blue whales.

Such prey are too big for most orca to tackle...

..but this matriarch has found one.

The blue whale seems to have been caught off guard.

Working as a team,

the orca keep their victim's blowhole beneath the surface...

..exactly as the matriarch taught them to do.

The hunting of blue whales by orca

has only recently been documented.

A new behaviour that is a response to changes in their ocean home.

But many animals today

are finding it hard to change their habits.

A trawler fishing off the coast of South Africa.

SHIP HORN

It has attracted thousands of seabirds...

..and hundreds of fur seals.

The trawler's presence illustrates the problem

that all these animals are now facing.

They're having to compete for their food with us.

This trawler has collected its fish

from the ocean's depths.

But such fish are low in nutrients.

They're junk food for the birds and the seals.

An adult Cape gannet male is flying in this crowd.

He's picked up what he can,

and now he must begin the long flight back to his family.

His home is Malgas Island,

the world's second largest Cape gannet colony.

GANNETS CHITTER

Using his own particular call,

he locates his lifelong partner and their chick.

But the fish he has scavenged

doesn't contain enough energy to nourish his chick.

Gannet chicks need rich, oily food such as sardines and anchovies,

the natural prey of these gannets.

As the parents change guard,

the mother takes her turn and heads out to sea.

She must find suitable food

if their chick is to survive.

Cape gannets have nested on Malgas Island for generations.

But due to our overfishing,

the gannets must now fly further out to sea

to find what they need.

At last, a hopeful sign.

Common dolphins.

The gannet mother knows they will lead her to food.

And she's not alone.

Sardines.

She dives at 50mph...

..but fails to catch anything.

The dolphins now encircle the sardines...

..and drive them upwards,

trapping them against the surface.

For the gannets,

it's the time to strike.

They dive as deep as 20 metres.

The mother makes one last dive...

..and catches one more fish.

Now she has enough food for her chick.

This hard-won meal

is the last she will give this chick.

It's now ready for independence.

CHICK CHIRPS

The chick makes its way to the edge of the colony,

where the wind is strongest.

But first she has to find her way through 40,000 neighbours.

SQUAWKING

She joins dozens of others...

..all preparing for their first flight.

She watches others make their attempts.

Those who catch the wind

lift off and are away.

Those who don't

have to face the fury of the Atlantic Ocean.

And great danger lurks beneath the waves.

SQUAWK

Cape fur seals.

Gannets aren't usually taken by seals...

..but in this depleted ocean,

prey of any kind is worth having.

SEAL SNARLS

SQUAWKING

The food she took from her parents

will only sustain her for a further day or so.

She waits for a gust of wind.

Her timing is not good.

Safe in the shallows.

Few get such a second chance.

She must try again.

She's made it.

The depleted ocean will remain a hugely challenging place for her.

But the oceans are ecologically very resilient

and they can recover faster than any other habitat on Earth,

given the right protection.

Gannet parents stay together for life, up to 20 years.

If their ocean home is given the chance to recover,

the vast shoals of fish on which so many depend

could reappear within the lifetime of these parents...

..and they could live to see a brighter future.

The Parenthood crew travelled to South Africa's Malgas Island

to film the remarkable parenting story of the endangered Cape gannet.

They're joined by Cape gannet expert Dr Zanri Strydom.

- I really have a passion for Cape gannets.

They've all got specific, different personalities.

I really like their

parenting strategies.

They're just different to other species of seabirds.

- So what we can see as soon as you arrive here

is a huge colony of birds, seabirds.

There's a lot of sounds, a lot of smells.

- And vast quantities of dried gannet droppings -

guano.

- We've got some strong northwesterlies blowing.

It's just blowing the guano dust everywhere.

- It's quite bad in your eyes, actually.

Do you feel the same? - Yeah. - Yeah.

- Oh!

- I just had a feather blowing into my mouth.

- The living conditions are a challenge,

but the island's most alarming feature for the crew

are the vast swathes of empty nests.

- Although it's really impressive,

you can also clearly see what it used to be like,

how big the population was

and now what it is.

This was all nests, right up until the house,

active nests, all of this,

and now the colony starts way back there.

Absolutely crazy.

- The single largest threat to the Cape gannet

is the decline of food resources.

Within just one generation of gannets,

24 years or so,

this colony has experienced a dramatic decline.

- The colony acts as this visual barometer

to the state of the ocean,

and it is really hard to see what happens

in the ocean sometimes, and how much we've taken from it,

and to think what animals are having to do to adapt to it.

- The gannets aren't the only ones suffering from a lack of food.

- On the right, just where the wave's cresting now.

- Starving Cape fur seals are also switching to new prey.

- Oh!

Got him. - Mm.

- There's not enough fish,

and what some seals have now learnt

is that the gannets carry fish in their stomach.

In a day, just one day,

we can have 100 or more predated out at sea.

- No! - In just one day.

- Up to 10,000 fledglings can be predated in a year,

accelerating the colony's demise.

But remarkably, some fledglings escape

and are offered a little help from Zanri.

- As a researcher, I know that there's always still hope.

It's so important to not think, "Oh, I'll just leave him to die."

That chick could have lived for another 24 years or so.

And then in those 24 years,

they can reproduce at least 20 times.

So you don't just lose that one fledgling -

you lose those 20 chicks

that he could have produced as a parent one day.

So we, all of a sudden, saw this juvenile Cape gannet.

He's been bitten by a seal.

We'll have a boat coming out today to the island

to come and fetch this little guy,

and we'll take him to the hospital, where he will undergo an operation,

and then he'll be released in a month or so.

- A month later,

Zanri visits Cape Town's Sanccob,

a seabird rehabilitation centre

where injured fledglings are recovering.

- So we're currently at Sanccob,

and we're very excited to be seeing how the gannets have been doing

after they've been rescued off the islands.

- Since being rescued,

the birds have been cared for daily by Sanccob's volunteers.

- 2.66.

- They undergo final health checks...

- And for the chest.

- ..ensuring that they're fit to be released into the wild

and begin their life of independence.

- So, chest is clear.

Body condition is good.

Oh, sorry, buddy.

OK, you can go in the pool.

- So here we are, spraying them down.

This is extremely important

because getting this mist on them stimulates them to flap their wings,

because they need to strengthen their muscles.

Some of them look like they already want to take off, almost.

It's a good sign.

- The following morning,

the eight birds that Zanri rescued

are ready for their big day.

- So, everything boils down to this.

It's been weeks of hard work,

trying to get these birds happy and healthy,

and now, finally, they are back where they belong.

There we go. Woohoo!

Last one. Let's go.

Get you back into the ocean.

He wants to go.

He's going, he's going!

Oh, nice!

Success. First one off.

- Rehabilitating these chicks

is vital to the recovery of this endangered species.

But if they are to have their own chance at parenthood,

it's up to us to ensure that they and generations to come

will have an ocean worth inheriting.

Next time...

..grasslands.

# Go steady

# You can take your time

# You're ready

# It'll all be fine

# And whatever you face

# There's a bond you can't break

# Cos I'll love you

# That'll never change

- # That'll never change

- # Oh-oh-oh-oh-oh-oh-oh - That'll never change

- # That'll never change

- # Oh - That'll never change

- # That'll never change

- # That'll never change That'll never change

- # That'll never change

- # That'll never change. #