01x02 - Ocean

[bunniefuu]

Much of our planet

still remains unexplored

..for most of it is covered

by water.

Every journey below the surface

can reveal something extraordinary.

More than a thousand new species

are discovered here every year.

The ocean is home to 80%

of all animal life on Planet Earth.

But today,

thriving in this varied world

sometimes demands

the most surprising behaviour.

The shallow seas of the tropics.

This may look like a paradise

..but beneath the surface,

it is an arena

for constant

life-and-death struggles,

where not everything

is quite as it seems.

A predatory lionfish

..on the hunt for shrimp

and small fish.

With so many places

for its prey to hide,

the lionfish has to be patient.

This shrimp appears tempting.

As the lion-fish closes in,

it fans out its fins

to disorientate its prey.

The hunter becomes the hunted.

Tricked by one

of the shallow sea's

most extraordinary predators

..a clown frogfish!

On its head, it carries

a fishing rod –

a modified dorsal fin,

baited with a lure -

easily mistaken for a shrimp.

But, when the fish stop biting,

it's time to pack the rod away

and move on.

And, for a frogfish,

that takes time.

Rather than swim, frogfish walk!

Its fins have, in effect,

become feet.

It may not look pretty,

but what appears to be coral living

on its skin is actually camouflage.

As every good angler knows,

picking the right spot is important.

Jigging the rod sends out

pressure waves

to attract the attention

of possible prey.

These dragonets

are certainly interested.

Almost there.

Hook, line, and sinker.

Like all shallow seas,

the cold waters

off the coast of North America,

benefit from the intensity

of the sunshine.

Here, that fuels

one of the fastest-growing

organisms on the planet

..giant kelp.

Towering forests

can eventually reach the height

of a 12-storey building.

These forests are nurseries

for young horn sharks.

As the sun begins to set,

they leave their daytime shelter

and set off into the heart

of the kelp forest to find food.

Barely half a metre long,

this little shark

is extremely vulnerable.

There are monsters here.

A giant sea bass –

weighing over 200kg

..and wolf-eels, with big teeth

that can crush

little red sea urchins.

But the biggest danger

comes from other sharks -

houndsharks

..and huge broadnose sevengills.

In this forest,

it pays to keep a low profile.

An angel shark

..one of the most deadly sharks

in the kelp forest,

and certainly

the best camouflaged.

An angel shark

will lie in wait for days

..but this one has already attracted

too much attention.

It's not welcome here.

Now, the coast is clear.

But angel sharks hunt

around the clock.

Openings for breathing,

called spiracles,

blow out sand

that helps cover its body.

The trap is set.

Staying close to the seabed is

a good way to avoid most predators.

Faster than the blink of an eye.

But it's not over yet.

Horn sharks have a secret w*apon.

Sharp spikes keep them very much

off the menu for most.

So, this young horn shark

can hunt in safety

..for now.

Violent winter storms

batter these kelp forests.

The plants can be ripped

from the seafloor

..and carried away far out to sea.

The open ocean

is a vast, featureless desert.

Even a small piece of drifting kelp

can become valuable.

It's just what these fish

have been searching for.

Here, shelter where eggs can be laid

unobtrusively is rare

..so they make the most of it.

Each female produces

up to a thousand eggs,

and the males rush in

to fertilise them.

All this activity attracts

the attention of blue sharks.

They can travel thousands of miles

through the ocean

in search of food

..and they may not have eaten

for weeks.

It seems that they're in luck.

But these fish are no easy meal.

They are flying fish!

The blue shark, however,

are not here for the fish

..they have come for the caviar.

But flying fish lay so many eggs,

that the sharks' feasts

hardly make an impact.

And, in a few months' time, a new

generation will take to the skies.

Floating islands of weed

are always attractive to creatures

looking for shelter

out in the big blue.

But, in today's ocean, they are

being replaced by something else

..plastic.

12 million tons of it

end up in the ocean every year.

The deadliest kind are discarded

fishing lines and nets.

Each year, it's likely over

half a million animals are ensnared

and k*lled by these "ghost nets."

But some animals are learning

how to take advantage

of the plastic rafts

..and use them for shelter,

or even as a home.

This male Columbus crab – barely

bigger than your thumb nail –

is a castaway.

Clinging to his net,

he may have been drifting

on ocean currents for months.

Now, fully grown,

he needs to find a partner.

But where?

Certainly not here,

alone on the net.

Columbus crabs are not good

swimmers, so this male is marooned.

Perhaps a passing loggerhead turtle

could be the chance

to hitch a lift.

Made it!

But there's more than one

passenger here -

a female Columbus crab!

They waste no time

in getting acquainted

..and start to mate.

This pair may well stay together

for the rest of their lives.

A turtle, after all,

makes an excellent home.

In return, the crabs provide

an onboard grooming service.

Finding a partner in the vast ocean

is not easy.

Dawn in the Sea of Cortez

..Mobula rays.

They're gathering here,

most likely to breed.

No-one is sure why they leap,

but the loud splashes

certainly seem to attract more rays.

Other creatures, however,

are also listening.

Orca have heard the splashes.

This female specialises

in hunting rays.

But today, she is teaching

two youngsters

the finer points

of Mobula ray hunting.

The rays are fast

and can outmanoeuvre an orca.

She knows she needs to herd

the prey into a tight group

..but she can't do that on her own.

It will take teamwork,

and that is today's lesson.

The young orca

are quick to catch on.

The rays are surrounded.

They dive

..only to be forced back up again

by the experienced female.

And now, with the exhausted rays

trapped against the surface,

she att*cks

..and the young ones

follow her lead.

This family are the only orca

known to hunt rays like this

..and they are lethally efficient.

But it appears that school

is over for today.

For a few battle-scarred survivors,

it's a lucky reprieve.

With the orca gone, the rays

can resume their courtship

..and they do so

in astounding numbers.

Tens of thousands of rays

in a single shoal.

Vast areas of our ocean

are yet to be explored.

The least known parts of it

are its great depths.

Only highly-specialised vessels

can take you there.

As you descend,

the sunlight rapidly fades.

200m down,

you enter the twilight zone

..an alien world, inhabited

by creatures beyond imagination.

A siphonophore – with a cloak

of lethal stinging tentacles.

Siphonophores repeatedly

clone themselves

and so grow to immense lengths.

This one measures 45m and is

the longest animal ever recorded.

With such deadly predators around,

creatures here go

to great lengths to hide.

A glass squid

..completely transparent,

except for its eyes

..and stomach,

so it is extremely difficult

to find in the gloom.

Below 1,000m,

all traces of sunlight

have disappeared.

This is the midnight zone.

Catching food in the perpetual

darkness is not easy.

A gulper eel.

Its giant, extendable mouth

can engulf prey

larger than its own body.

Two miles down,

you finally reach the ocean floor.

We know more

about the surface of Mars.

The pressure of the water is 300

times greater than at the surface

..and it's freezing cold.

Yet, amazingly,

there are animals living here.

Muusoctopus robustus,

nicknamed the pearl octopus.

Breeding, in these

extreme conditions poses

a particular problem

for these animals.

At these low temperatures,

this female's eggs could take

over ten years to develop.

So she travels

to a very special place.

This is the largest known

gathering of octopus in the world.

She joins 20,000 other females

..all here to lay their eggs.

Water, heated deep

in the Earth's crust,

rises through cracks

in the seabed

..raising the temperature

to as much as 10 degrees Celsius.

A deep-sea thermal spa!

This warmth significantly speeds up

the development of their eggs.

Even so, they will still take

nearly two years to hatch.

Once a female is settled,

she won't move from her spot

..not even to feed.

She will constantly tend

to her brood –

keeping them clean,

and oxygenating them

with jets of water.

Pearl octopus mothers must surely be

amongst the most devoted.

After almost two years,

the ordeal take its toll.

But the vigil is almost over.

The last of the brood

are gently encouraged to leave.

But this will be a final act.

Like all the mothers here, this

octopus is starved and exhausted.

Her life will soon be over.

But this devotion means

that her offspring are among

the largest and most developed

of any octopus

and have the best chance of survival

in the demanding world of the deep.

We're finding more of these

strange hot springs every year.

In some places,

they can be astonishingly violent.

Super-heated water –

hot enough to melt lead -

spouts from the seafloor.

Dissolved minerals

condense around them

to form towering chimneys,

known as hydrothermal vents.

They are home to unique

communities of animals

that all rely on the nutrients

in the scalding water.

Some suggest that vents

like these could be the places

where life on Earth first began

four billion years ago.

And there is now evidence

of hydrothermal vents

on the moons of Jupiter and Saturn.

Could they too be supporting life?

Here on Earth,

the influence of these vents

extends far beyond their chimneys.

The essential nutrients

carried in these plumes

can rise all the way to the surface

two miles above.

Here, they stimulate the rapid

growth of tiny marine plants

..on an astronomic scale.

This phytoplankton is so abundant

that it produces half

of all the oxygen on Earth.

It's also food for a host

of minute animals -

zooplankton.

Together, they are the basis

of the food chains

that sustain

nearly all life in the ocean.

In the Pacific waters

off South America,

they feed anchovy

that gather here in billions.

This is one of the world's

most productive ecosystems.

These South American

sea lions are on the hunt.

But the anchovy shoal

has already been located

..by the planet's

most efficient hunters.

A net, over half a mile long,

encircles the shoal.

It can trap over a million fish.

But the sea lions

aren't about to go hungry.

They have learnt

to look for holes in the net.

Why waste energy when food

comes to you as easily as this?!

As more and more sea lions arrive,

some change their tactics.

They line up

on both sides of the net

..and wait.

As the net tightens, the anchovy

panic and rush for the surface.

This is the moment the sea lions

have been waiting for.

It's such an effective way

of hunting that the sea lions here

are changing

their natural behaviour

..and are raiding the fishing nets

in their thousands.

With the net almost drawn in,

the fishermen b*at out

a warning signal.

Time is up.

In the confusion,

not everyone manages to escape.

The trapped sea lions are in danger

of being drowned.

Pups are separated

from their mothers.

Then, at the last minute, the

fishermen briefly drop their net

..and the trapped sea lions

can escape.

But many are not so lucky.

Around the world, millions

of animals are accidently caught

and die in fishing nets every day.

And this by-catch, as it's known,

is pushing many species

toward extinction.

Animals have evolved

in remarkable ways

to the demands of life in the ocean.

But can they now adapt

to the new challenge -

living alongside us?

The open ocean is home

to some of the largest

and most extraordinary animals

on Earth.

But here, off the Canary Islands,

the Planet Earth team are searching

for one of its smaller,

and less familiar residents.

We're looking for a tiny creature

called a Columbus crab,

which is only about the size

of your thumbnail,

which live on floating objects

in the open ocean.

Columbus crabs were once

only found on natural debris,

like driftwood or seaweed,

but the oceans are changing,

and they've been forced to adapt.

One of the most common items

they find is discarded fishing gear.

Over a million tons is left adrift

in the ocean each year.

And Columbus crabs are now

making their homes

on these unnatural materials.

Surprisingly, Columbus crabs

are thriving on this new habitat.

But, for larger ocean creatures,

these nets can be lethal.

Loggerhead sea turtles

are especially vulnerable.

Many times, they are very injured

and many times

they don't even survive.

It's a sad situation.

As a rule, wildlife film-makers

observe natural behaviour

and do not interfere.

But this is far from natural.

The team feel they must take action.

Sh

It seems that the turtle

is quite OK.

We'll just finish to cut

the plastic and then we release it.

It's a bittersweet moment,

as this is one of eight turtles

they rescued whilst filming here.

This situation is not natural,

it's something that is

being caused by human beings.

Sadly, the crew now face

dilemmas like this

on many of their

filming expeditions

..including, when they travelled

to the Pacific coast of Chile,

to show how sea lions

are competing for food

with one of the biggest fisheries

on Earth.

Expedition leader Fernando Olivares

takes the team to the fleet.

Diving near fishing nets

is extremely dangerous,

so the crew must ensure they have

the full cooperation

of the fishermen.

Pretty hazardous place to dive.

It's just a case of trying

to keep an eye on the divers,

but the sea lions also like

to go down and blow bubbles,

so you'll think

you're following the divers,

and then a sea lion will pop up.

Taking the utmost care,

the divers get a close-up view

of the sheer scale of the operation.

This one net must have

about 15 tons of fish in it

and there's eight or nine boats

in this one little bay,

and these are just the small boats.

Out there, there are huge

factory ships that are taking

even bigger catches.

How much fish a year from just here?

From a million tons a year

more or less.

The catches are so vast,

the sea lions have changed

their natural behaviour

to collect anchovies

directly from the nets.

But it's a risky strategy.

The crew witnessed sea lions

caught in nets multiple times.

Whoa, it's intense mate,

there are so many in there.

There's a pup stuck in the net,

calling to its mother,

and its mother's just on the outside

of the net calling back.

That's really hard to watch.

Oh, the pup's really panicking now.

Sometimes, fishermen are able

to release trapped sea lions

..but not this time.

The pup is in serious danger.

Once again,

the crew decide to step in.

Hey, he's going to go

inside of the net to save him.

Wow.

Nice, really nice.

It's a relief this time

..but it highlights the new

realities of filming wildlife

in today's changing ocean.

Next time, a journey to Earth's

greatest wilderness -

deserts and grasslands

..where nature puts on

its most dramatic show.

Habitat Explorer brings animals

and their habitats to life.

Explore this free interactive

and make origami animals.

Go to

And follow the links

to the Open University.

Or to order a free printed version,

visit the website

or call the numbers on the screen.