Original subtitles

(lighthearted music)

(dolphin clicking)

(dolphin creaking)

- [David] A newly born bottlenose dolphin,

its skin still creased by the tightness of the womb

from which it has only just emerged.

(lighthearted music continues)

(dolphin clicking)

(lighthearted music continues)

Its mother is devoted to it,

and will care for it for the next five years.

That is an unusually long time for any oceangoing animal.

Most marine creatures simply abandon their young

as soon as they appear.

(dolphin clicking)

But those who care for them,

do so in some very remarkable ways.

(waves crashing)

(water splashing)

(lighthearted music continues)

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.

(exciting whimsical music)

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 urchin spines.

When a female is ready to spawn,

she leads a male away from the show.

(whimsical music)

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.

(hopeful music)

But for the next four weeks, he won't be able to eat.

Starvation, however, is the least of his worries.

(stirring music)

There are predators around.

Of many kinds.

(stirring music continues)

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.

(anemone purrs)

This anemone, however, seems to have vacancies.

The male picks his moment

to leave the safety of the urchin spines.

(tense whimsical music)

Here he's not alone.

(anemone purring)

(tense whimsical music fades)

But this anemone fish doesn't mind sharing.

He has found a new home for his young.

(hopeful music)

But they seem unwilling to leave his mouth,

so he gives them a little encouragement.

(hopeful music continues)

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

(hopeful music continues)

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.

(dolphin creaking)

(dolphin whistling)

A bottlenose dolphin mother spends five years

showing her calf the skills necessary for survival.

(dolphin clicking)

And she does so through play.

(dolphin whistling)

Her lessons start with a trick.

First, balance a piece of coral on your nose.

(epic music)

Second, take it up to the surface.

Third, drop it.

And then, before it reaches the bottom,

(dolphin creaking)

catch it.

(dolphins clicking)

All adults can perform this trick.

Perfecting it is, therefore,

a rite of passage for this calf.

(soft music)

(dolphin creaking)

First, balance the coral.

(quirky music)

(dolphin clicks)

This is not easy.

Try again.

(quirky music continues)

Step one, balance the coral.

(dolphin clicking)

Or bite it. And skip to step two.

Now, catch it.

(dolphin clicking)

(quirky music continues)

(dolphin continues clicking)

(dolphin whistling)

(quirky music continues)

Got it. Just in time.

There are also other more important skills

that a calf must learn.

(dolphin clicking)

The mother leads her youngster

to one particular kind of coral that is almost hidden,

one that has a special extraordinary characteristic.

It produces anti-fungal chemicals

which dolphins rub on their skin.

These dolphins remarkably medicate themselves.

And they pass on this knowledge to their young.

(dramatic music)

(dolphin whistling)

(dramatic music continues)

Passing on skills such as these

is part of good parenting.

(dolphin clicking)

(waves crashing)

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.

(mysterious music)

And one remarkable fish has evolved here

and exists nowhere else.

The weedy seadragon.

(serene music)

It's marvellously camouflaged,

and an exceptionally dedicated parent.

(serene music continues)

In spring, male and female dance together.

They mirror each other's actions.

(serene music continues)

(serene music fades)

He seals their bond by attaching her eggs to his tail.

The eggs are bright pink

and make him dangerously conspicuous.

(ominous music)

But within a few weeks, the eggs become covered by algae.

And that makes them less obvious.

(lighthearted music)

After six weeks, his parenting duties come to an end.

The baby dragons begin to hatch.

(lighthearted music continues)

They're just two centimetres long,

perfect miniatures of their parents.

(lighthearted music continues)

They share their microworld

with one of the strangest creatures in the seas.

(uncanny music)

Skeleton shrimps.

They're seldom noticed, but they live in oceans worldwide.

They're armed with formidable weapons,

and they are remarkably attentive parents.

(uncanny music continues)

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.

(uncanny music continues)

And that is where she takes them.

(uncanny music continues)

Carrying as many young as this is exhausting.

And if she stops, she risks everything.

(spines scrunching)

She falls onto an urchin,

which catches her with its tube feet

and starts transporting her towards its mouth.

(suspenseful music)

But she wriggles free and resumes her climb.

(whimsical music)

Skeleton shrimps live in colonies

and compete for the best feeding places.

(whimsical music continues)

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.

(suspenseful music)

(whimsical music)

Her young clamber over her head to claim a share.

Once fed, they leave,

giving her a break from the responsibilities of motherhood.

(whimsical music fades)

Seaweed, wherever it grows,

provides animals with both food and shelter.

(animals chirping)

The Shetlands, the northern-most of the British isles,

(otter grunts) (otter chirping)

it has the densest population

of Eurasian otters in the world.

These three cubs are five months old.

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

(water splashes)

(water burbling)

She finds it in the seaweed,

where there are great numbers of small fish.

(lighthearted music)

The fish are well-camouflaged and not easy to see,

(dramatic music)

but she uses her whiskers to feel for them.

(dramatic music continues)

(water splashing)

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.

(otter grunts)

(otter squeals)

So this mother has to catch a lot of food.

(lighthearted music)

(otter grunts)

She must also feed well herself

if she's to survive the winter.

(lighthearted guitar music)

(water splashes)

The youngsters squabble over every fish.

(otter squealing)

(otter grunting)

(lighthearted guitar music continues)

(otter squeals)

The biggest, the most vigorous cub is the first to get food.

And the smallest often goes hungry.

(otters squealing)

This small male, however, decides to fish for himself

and joins his mother farther out to sea.

(water burbling)

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.

(soft music)

His mother has been too busy to notice

that he has strayed.

(otter squealing)

And now he is lost.

(otter continues squealing)

(water splashing)

(otter continues squealing)

Over a quarter of otter cubs don't survive their first year.

Many, because they lose touch with their mothers.

(otter squeals)

All he can do is to keep calling.

(otter continues squealing)

(otter grunts)

(lighthearted music)

(otter continues squealing)

(otter grunts)

(lighthearted music continues)

Winter in Shetland is very cold

and life becomes hard for otters, both old and young.

(lighthearted music continues)

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

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

(lighthearted music fades)

(wind swooshing)

California's Channel Islands

are surrounded by one of the richest of marine nurseries,

a forest of giant kelp.

(ethereal music)

This area has now been declared a marine reserve

where fishing is totally banned.

(ethereal music continues)

As a consequence,

over a thousand different species of animals now live here.

Among them giant sea bass,

which elsewhere are critically endangered.

(ethereal music continues)

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.

(quirky music)

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.

(quirky music continues)

(ominous music)

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.

(whimsical music)

Which takes advantage of the constant intruders

to steal the garibaldi's eggs.

(whimsical music continues)

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

(ominous music)

They eat virtually everything in their path.

From the nest of a garibaldi

to the entire kelp forest.

(dramatic music)

He does all he can to keep the urchins away.

(dramatic music continues)

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.

(poignant music)

And that, combined with an ever-warming sea,

has created a plague of urchins

that have devastated the sea floor.

(poignant music continues)

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.

(poignant music continues)

Many animals have changed their parental behaviour

in order to survive in this new world.

(dramatic music)

Pale octopus are relatively short-lived.

And this female has just over a year

in which to breed and raise her young.

(dramatic music continues)

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

(pensive music continues)

She must choose carefully. Good dens are rare.

(pensive music continues)

A discarded toilet could perhaps serve,

but this one is engaged

and is already being fought over.

A squirt from its owners ink sack makes things clear.

She keeps looking.

Many of the available den sites are too exposed.

(tense music)

She wants somewhere a little more secluded.

This plastic pipe is also occupied

by a male.

(uncanny music)

But he is signalling his readiness to breed.

(uncanny music continues)

It's an irresistible performance.

So she inspects his den.

(uncanny music continues)

It may not look like much,

but to her, apparently, it will do.

(epic music)

He nudges her into his home.

(epic music continues)

She gives his den and him her seal of approval,

and the two mate.

(epic music fades)

A few days later, she starts laying her eggs

inside the pipe.

She will eventually produce about 500 of them.

(soft music)

She strokes them with her suckers

to keep them clear of algae.

Her home will hide her,

and is easy to defend.

(soft music continues)

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

All octopus mothers die in their dens.

(soft music continues)

As her eggs hatch, she takes her young in her arms

and uses her syphon to propel them to independence.

(soft music builds up)

In their yearlong 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.

(poignant music fades)

(waves crashing)

As all seas change,

those species with sufficient intelligence to adapt

are finding new ways to support their offspring.

(downhearted music)

And there are few sea creatures

more inventive in their search for food

than killer whales.

(whale whistles)

(epic music)

(water splashes)

They're powerful, swift, and agile.

But the key to their success

lies beyond their physicality.

(whales whistle)

It comes from their sociability

and the way they use their complex relationships

to teach one another.

(whales whistle)

Each family is led by its grandmother, the matriarch.

(whales blow)

She may live into her 80s,

far beyond the age of producing calves of her own,

(whale squeaks)

but her responsibilities as a leader never cease.

(whales blow)

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

(epic music)

She initiates a chase.

And the rest of the family join her.

(whales blow) (epic music continues)

(water splashing)

(whales blow)

(water splashing)

But this is not a game.

(whale blows)

(water splashing)

One deliberately stop 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.

(whale blows)

They are practising the actions

they will use to drown their prey.

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

(epic music builds up)

They hunt the largest animals that have ever lived.

(whale blows)

Blue whales.

Such prey are too big for most orca to tackle,

but this matriarch has found one.

(suspenseful music)

(whales blow)

(water splashing)

(suspenseful music continues)

The blue whale seems to have been caught off guard.

Working as a team,

the orca keep their victims blowhole beneath the surface,

(suspenseful music continues)

exactly as the matriarch taught them to do.

(water splash)

(suspenseful music continues)

(water continues splashing)

(suspenseful music crescendos)

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,

it has attracted thousands of seabirds

(waves crashing)

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.

(birds squawking)

This trawler has collected its fish from the ocean's depths,

(water splashing)

but such fish are low in nutrients.

(bird croaks)

They're junk foods for the birds and the seas.

(water splashing)

(birds squawking)

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.

(waves crashing)

His home is Malgas Island,

the world's second-largest Cape gannet colony.

(birds squawking)

Using his own particular call,

he locates his lifelong partner and their chick.

(birds continue squawking)

(lighthearted music)

But the fish he has scavenged doesn't contain enough energy

to nourish his chick.

Gannet chicks need rich, oily foods

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.

(waves crashing)

(birds squawking)

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.

(pensive music)

At last, a hopeful sign.

(water splashing)

Common dolphins.

(suspenseful music)

The gannet mother knows they will lead her to food.

(suspenseful music continues)

(water splashing)

And she's not alone.

(birds squawking)

(water continue splashing)

(dolphin whistles)

Sardines.

(birds squawking)

She dives at 50 miles an hour,

(water splashes)

(suspenseful music)

but fails to catch anything.

The dolphins now encircle the sardines,

(suspenseful music continues)

and drive them upwards, trapping them against the surface.

For the gannets, it's the time to strike.

(water splashing)

(suspenseful music continues)

They dive as deep as 20 metres.

(suspenseful music continues)

The mother makes one last dive

(water splashes)

and catches one more fish.

(water splashes)

(birds shrieking)

(lighthearted music)

Now she has enough food for her chick.

(waves crashing)

(lighthearted music continues)

(birds squawking)

This hard one meal is the last she will give this chick.

(lighthearted music continues)

(birds continue squawking)

It's now ready for independence.

(pensive music)

The chick makes its way to the edge of the colony

where the wind is strongest.

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

(birds squawking)

She joins dozens of others,

all preparing for their first flight.

(waves crashing)

She watches others make their attempt.

Those who catch the wind lift off and are away.

Those who don't have to face the fury of the Atlantic Ocean.

(waves crashing)

And great danger lurks beneath the waves.

(bird squawks)

(suspenseful music)

(waves crashing)

Cape fur seals.

(suspenseful music continues)

(bird squawks)

(water splashing)

(suspenseful music continues)

Gannets aren't usually taken by seals,

but in this depleted ocean,

prey of any kind is worth living.

(fur seal grunts)

(birds squawking)

(tense music)

(bird squawks)

The food she took from her parents

will only sustain her for a further day or so.

She waits for a gust of wind.

(waves crashing)

(tense music)

(wings fluttering)

(tense music continues)

Her timing is not good.

(tense music continues)

(fur seal grunts)

(suspenseful music)

(water splashing)

(suspenseful music continues)

Safe in the shadows.

Few get such a second chance.

(suspenseful music continues)

She must try again.

(bird squawking)

(suspenseful music continues)

(fur seal grunts)

(waves crashing)

(epic music)

She's made it.

(waves crashing)

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

(birds squawking)

and they could live to see a brighter future.

(birds squawking fades)

(lighthearted music)

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 parenthood strategies.

They're just different to other species of seabirds.

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

there's a huge colony of birds, seabirds.

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

- [David] And vast quantities

of dried gannet droppings, guano.

(whimsical music)

- [Mae] We've got some strong Northwesterlies blowing.

It's just blowing the guano just everywhere.

- It's quite bad in your eyes actually.

Do you feel the same? - Yeah.

- Yeah. (Mae exclaims)

I just had feather blowing into my mouth.

(camera lens squeaks)

- [David] 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.

- [David] The gannets aren't the only ones

suffering from a lack of food.

- [Crew Member] On the right,

just where the waves crashing now.

- [David] Starving cape fur seals

are also switching to new prey.

(bird squawking)

- [Crew Member] Oh.

(crew member speaks indistinctly)

- There's not enough fish.

And what some seals have now learned

is that the gannets carry fish in their stomach.

In a day, just one day,

we can have a hundred or more predated out at sea.

- [Crew Member] No. - In just one day.

- [David] Up to 10,000 fledglings

can be predated in a year,

accelerating the colony's demise.

But remarkably, some fledglings escape

and 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've 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've 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.

- [David] A month later,

Zanri visits Cape Town's SANCCOB,

a seabird rehabilitation centre

where injured fledglings are recovering.

(birds shrieking)

- 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.

(birds shrieking)

(poignant music)

- [Volunteer] Okay, next.

- [David] Since being rescued,

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

- [Volunteer] 2.66.

- [David] They undergo final health checks.

- And for the chest...

- [David] Ensuring that they're fit

to be released into the wild

and begin their life of independence.

- Okay, chest is clear. Body condition is good.

Oh, sorry buddy.

Okay, you can go in the pool.

(water splashes)

(birds shrieking)

(water sprayer hissing)

- So here we are, spraying them down.

This is extremely important

because getting this mist on them

stimulates them to slap 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.

(lighthearted music)

- [David] The following morning,

the eight birds that Zanri rescued

are ready for their big day.

(bird squawking)

(lighthearted music continues)

- 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.

(lighthearted music continues)

Here we go. (water splashes)

Woo-hoo!

(water splashing)

Last one, let's go.

Get you back into the ocean.

(water splashes)

(lighthearted music continues)

He wants to go.

He's going. He's going.

Oh, nice! Success!

First one off.

- [David] Rehabilitating these chicks

is vital to the recovery of this endangered species.

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

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

will have an ocean worth inheriting.

(lighthearted music)

(lighthearted music fades)