Original subtitles

Whales.

Ocean giants.

Ocean giants.

Ancient mariners.

(WHALE WHISTLES)

Their songs, majesty

Their songs, majesty

and sheer size fill us with joy and awe.

In their vast shadow, a human can feel very small.

In their vast shadow, a human can feel very small.

(WHALE HOOTS)

(WHALE HOOTS)

They were here long before us...

..caring for their young...

..hunting...

..voyaging...

But now we are changing their world.

But now we are changing their world.

So, now I want to see through their eyes,

meeting them on their terms,

to find how their future and ours are inseparable.

to find how their future and ours are inseparable.

(WHALE MOANS)

I'm tracking the latest discoveries

on the hunting behaviour of whales and dolphins.

on the hunting behaviour of whales and dolphins.

There are over 90 species...

..all very different,

(WHALE BELLOWS)

..but with one thing in common.

(ORCA SQUEAKS)

(ORCA SQUEAKS)

Whatever their shape or size...

(DOLPHINS CLICKING)

..they are all predators.

..they are all predators.

The whales and dolphins have been commanding our oceans

for perhaps 50 million years.

With the biggest brains,

the biggest appetites...

..and also the most creative hunting strategies.

..and also the most creative hunting strategies.

From the equators to the poles,

they are truly the ultimate hunters of our seas.

(ORCAS SQUEAK)

(ORCAS SQUEAK)

But whales' predatory strategies

are as varied as whales themselves,

often specific to a location or prey.

often specific to a location or prey.

And I want to understand the challenges they face

in our changing oceans.

in our changing oceans.

My journey into the world of ocean hunters

begins with the most iconic of all...

begins with the most iconic of all...

..orca, also known as killer whales.

In the far north of Norway...

..they feast...

on seasonal shoaling herring.

For just two months of the year,

the fjords of northern Norway play host to a gathering

of some of the finest hunters on our planet.

of some of the finest hunters on our planet.

We are inside the Arctic Circle and surrounded

by a pod of orca.

This is the largest species of dolphin,

and, I think, the most sophisticated,

complex and adept of all predators.

complex and adept of all predators.

There's just nothing that compares.

If any whale has a fearsome reputation...

If any whale has a fearsome reputation...

..it's these.

(OMINOUS MUSIC)

(OMINOUS MUSIC)

The ocean's top predators...

The ocean's top predators...

..they were named as a killer of whales.

Scientists consider them the most complex marine predators.

Scientists consider them the most complex marine predators.

They target specific prey,

and in nature have never harmed a human.

and in nature have never harmed a human.

And what better way to put this to the test

than to swim alongside them?

than to swim alongside them?

(ORCAS CLICK AND SQUEAK)

(ORCAS CLICK AND SQUEAK)

(ORCA SQUEAKS)

Usually they just cruise on by.

But this time, she turns...

..and comes to join me.

(ORCA CLICKS)

(SPIRITUAL CHORAL MUSIC)

Nose to nose... with our planet's greatest predator.

Nose to nose... with our planet's greatest predator.

(ORCA SQUEAKS)

In two decades of working with orca,

In two decades of working with orca,

that's the first time I've had one show real interest in me underwater.

that's the first time I've had one show real interest in me underwater.

She was looking at me, she was studying me,

and going around, and around, and around,

and going around, and around, and around,

and you can't tell if that's just curiosity...

..or if they're searching for a weakness.

..or if they're searching for a weakness.

But in that moment, when you look in their eye,

you can see the intelligence,

you can see them processing you, figuring out what you are.

you can see them processing you, figuring out what you are.

(ORCA SQUEAKS)

I have just had a proper moment...

..with the greatest predator,

potentially, our planet has ever seen.

potentially, our planet has ever seen.

Killer whales are capable of taking prey many times larger

Killer whales are capable of taking prey many times larger

and more formidable than a human...

..but they're smart enough to be selective.

What makes the perfect hunter is not big teeth or muscles,

What makes the perfect hunter is not big teeth or muscles,

it's having that brain power and its processing power.

Its curiosity is probably the closest of any other on the planet

Its curiosity is probably the closest of any other on the planet

to us as human beings.

(MAJESTIC ORCHESTRAL MUSIC)

But the orca is rarely a lone hunter.

But the orca is rarely a lone hunter.

Perhaps the secret to the orca's success is the pod,

their social group.

They are the most potent matriarchy on the planet,

They are the most potent matriarchy on the planet,

and youngsters may stay with their mothers for their entire lives.

Their extraordinary communication

Their extraordinary communication

enables them to do things that other animals simply can't.

And their closeness and cooperation

is clearly seen in the Sea of Cortez.

(FISH SPLASING)

These are mobula rays,

here in their thousands to feed and breed.

here in their thousands to feed and breed.

For an orca hunting on her own, it's hard to separate a target.

For an orca hunting on her own, it's hard to separate a target.

(ORCA SQUEAKS)

(ORCA SQUEAKS)

The arrival of her pod changes the odds.

(ORCA SQUEAKS)

They begin to co-ordinate their hunt.

Their multi-pronged attack

panics the mobulas...

..breaking apart the school.

Now, the orca have the advantage.

Now, the orca have the advantage.

They pick off the rays one...

..by one.

By working together, every whale reaps the rewards.

By working together, every whale reaps the rewards.

But for some orca, the greatest advantage

comes not from sharing the hunt,

comes not from sharing the hunt,

but from sharing knowledge.

Over in New Zealand, this helps a different pod

Over in New Zealand, this helps a different pod

take much more risky prey.

It's a tempting meal,

but a sting ray's tail barb delivers a lethal toxin.

but a sting ray's tail barb delivers a lethal toxin.

(ORCA CLICKS)

(ORCA CLICKS)

The key is to approach from above...

The key is to approach from above...

..and grab the head end.

And then flip the ray upside down.

This puts it into a trance-like state called tonic immobility.

This puts it into a trance-like state called tonic immobility.

Now helpless, it can be consumed safely.

Now helpless, it can be consumed safely.

And she's not the only one doing this.

This method of handling sting rays has been learned by others,

This method of handling sting rays has been learned by others,

and is now practiced throughout the pod.

Many other orca groups also have very specific hunting techniques.

Some scientists say this shows that, like us,

killer whales have culture;

shared behaviour passed down through generations.

shared behaviour passed down through generations.

(MAJESTIC ORCHESTRAL MUSIC)

(ORCA SNORTS)

The orca have the ability to feed on everything,

from the smallest fish right up to the largest animal

from the smallest fish right up to the largest animal

ever known to have lived, the blue whale.

It's this adaptability,

this inventiveness that makes them such a success in all our oceans.

this inventiveness that makes them such a success in all our oceans.

But some whales are far more specialised.

So, what does the future hold for them

with our oceans in flux?

with our oceans in flux?

I'm on a quest to understand the new challenges

I'm on a quest to understand the new challenges

faced by whales hunting in our modern world.

Around 50 million years ago,

Around 50 million years ago,

land-based mammals abandoned their terrestrial lifestyle

and took to the waves.

In the millions of years since,

a diverse array of forms has evolved,

from porpoises the size of puppy dogs,

from porpoises the size of puppy dogs,

to the largest animals ever known to have lived.

But how they hunt couldn't be more varied.

To see one of the most impressive of them all,

To see one of the most impressive of them all,

we must venture to Baja California,

feeding grounds for the largest animal

ever to have lived on our planet...

ever to have lived on our planet...

(SNORTS)

..the blue whale.

(SERENE ORCHESTRAL MUSIC)

This female may be 25 metres

and weigh over a hundred tonnes.

And she's hungry.

Remarkably, the largest animal on earth feeds on something very small:

Remarkably, the largest animal on earth feeds on something very small:

shrimp-like plankton called krill.

shrimp-like plankton called krill.

These seasonal blooms form vital banquets for blue whales.

These seasonal blooms form vital banquets for blue whales.

She can descend 200 metres to feed.

Lunging, she engulfs as much as 100 tonnes of krill and water,

Lunging, she engulfs as much as 100 tonnes of krill and water,

swelling her throat like a balloon.

(WHALE EXHALES)

We once thought whales were bad for fish stocks...

We once thought whales were bad for fish stocks...

..but scientists are discovering

that blue whale poo acts like fertiliser on plant plankton...

that blue whale poo acts like fertiliser on plant plankton...

..which feed the krill that blue whales and others rely on.

..which feed the krill that blue whales and others rely on.

So, whales have been enhancing the health of our oceans

for millions of years.

But global warming and ever more acidic oceans are harming krill.

But global warming and ever more acidic oceans are harming krill.

Blue whales have been slowly recovering from whaling,

but without krill they would be lost.

but without krill they would be lost.

If we're endangering the largest animal on earth,

what other mistakes are we making?

what other mistakes are we making?

To see how we could affect their future,

To see how we could affect their future,

I want to know more about the highly varied hunting behaviour of whales.

I'm heading to Bimini, in the Bahamas,

I'm heading to Bimini, in the Bahamas,

where there is a hunter with a unique way of finding food.

(VIA DIVING RADIO): "Just offshore are these sand flats,

"which stretch on as far as the eye can see.

"which stretch on as far as the eye can see.

"But when you get your eye in, you can see they're filled

"with razor fish, garden eels, sand eels."

These fish pluck particles of food

from the water column.

They seem exposed, with nowhere to hide.

But at the first sign of danger...

..they disappear from sight.

But one seabed scanning predator

isn't searching with its eyes.

isn't searching with its eyes.

"These craters are the feeding signs

"of the bottle-nosed dolphin."

"of the bottle-nosed dolphin."

(DOLPHIN CLICKS AND WHISTLES)

They're using echolocation, beaming out high-pitched sounds

to build a picture of their world

to build a picture of their world

using the echoes that bounce back.

"The dolphins cruise along the bottom,

"The dolphins cruise along the bottom,

"and all the time, they're sending their echolocation

"down through the sand, penetrating down

"to find what's buried beneath."

(DOLPHIN CLICKS)

(DOLPHIN CLICKS)

It's a remarkable technique.

(DOLPHIN CLICKING)

(DOLPHIN CLICKING)

"When they sense something, they exhibit a left-hand turn...

"When they sense something, they exhibit a left-hand turn...

"..and then plunge their snout, their rostrum down into the sand

"..and then plunge their snout, their rostrum down into the sand

"as they try and find their food.

"Did you see that? Perfect!"

"Such an incredible sight, seeing a dolphin

"doing a headstand on the bottom

"and then coming up with a fish in its mouth."

Although bottle-nosed dolphins live all over the world,

this strategy is only known from this region.

this strategy is only known from this region.

(DOLPHIN CLICKING)

"This population here all seem to have learnt this technique.

"Perhaps, just like the orca,

"they have a culture that enables them to pass on this skill."

(DOLPHIN CLICKING)

(DOLPHIN CLICKING)

These dolphins have a specialised way

of finding food in this exact environment.

of finding food in this exact environment.

But what happens if that environment starts to change?

But what happens if that environment starts to change?

Could being a specialist make you more vulnerable?

The best place to investigate is an environment

we're already changing rapidly;

the last place you'd expect to find a member of the whale family...

the last place you'd expect to find a member of the whale family...

(BIRDS CACKLE AND TWITTER)

..deep in the heart of the Amazon.

..deep in the heart of the Amazon.

(INSECTS CHIRRUP)

Like strong tea, these waters are stained with tannins,

dissolved from forest leaves.

Here in the darkness lives the most unusual dolphin of all.

Here in the darkness lives the most unusual dolphin of all.

(DOLPHIN WHISTLES)

This Amazon river dolphin,

or boto, is uniquely adapted to live in this strange freshwater habitat.

or boto, is uniquely adapted to live in this strange freshwater habitat.

With pink skin, tiny eyes and a bulbous forehead,

With pink skin, tiny eyes and a bulbous forehead,

he's a curious-looking creature.

But this is a sophisticated hunter,

able to take more than 40 species of prey,

able to take more than 40 species of prey,

including piranhas.

With such poor visibility,

he relies on echolocation...

he relies on echolocation...

(DOLPHIN CLICKING)

..building a soundscape picture of his world.

(DOLPHIN SCREECHES)

His low-profile dorsal fin avoids snags...

His low-profile dorsal fin avoids snags...

..and his flippers, which move independently,

allow him to freely navigate...

..and home in on hiding fish.

(DOLPHIN CACKLES)

(DOLPHIN CACKLES)

His highly sensitive beak

is ideal for snatching fish from the deepest thickets.

is ideal for snatching fish from the deepest thickets.

These boto are the ultimate specialists,

These boto are the ultimate specialists,

perfectly adapted to their unique environment.

But that makes them vulnerable.

But that makes them vulnerable.

Fishing is emptying their home of food,

and fine-meshed modern nets can be a deathtrap.

and fine-meshed modern nets can be a deathtrap.

We've driven other river dolphins extinct,

We've driven other river dolphins extinct,

and unless we learn our lessons fast,

the boto could be next.

Scientists and conservationists

are in a race against time to protect whales.

But is the world simply changing too rapidly?

But is the world simply changing too rapidly?

One human activity

has bigger consequences for whales than any other...

(SEA BIRDS SQUAWKING)

(SEA BIRDS SQUAWKING)

..fishing.

We have replaced whales and dolphins

as the largest consumer in the oceans.

as the largest consumer in the oceans.

Here in the fjords of Norway, the catch is monitored,

Here in the fjords of Norway, the catch is monitored,

so there should be enough fish left for the whales,

but it's still affecting them.

To see what's happening,

To see what's happening,

I need to dive right alongside the gigantic boats

as they set their nets overnight.

(BREATHING TANK HISSES)

(VIA DIVING RADIO): "As the fishing boats bring in the nets,

"there could be several hundred tonnes of herring...

"..shimmering silver scales

"and thousands, if not millions, of fish trapped inside."

We're plundering the whales' natural food,

but some whales are learning how to use the boats to their advantage.

but some whales are learning how to use the boats to their advantage.

Orca recognise the characteristic sounds of a boat fishing.

To these ingenious predators, the clangs

and clanks are a dinner bell.

(SEA BIRDS CRYING)

(SEA BIRDS CRYING)

(ORCA WHISTLES)

Taking just the fish that spill from the nets,

the orcas' technique is surprisingly delicate.

the orcas' technique is surprisingly delicate.

Drawing other orca into the fjord, it's a mighty gathering.

Drawing other orca into the fjord, it's a mighty gathering.

(ORCAS SQUEAKING)

But they're not the only hunters arriving for this unusual feast.

But they're not the only hunters arriving for this unusual feast.

Giant humpbacks come in to join them.

Elsewhere, these whales would be mortal enemies.

But here, they feast together, mere metres from the boat.

(MAJESTIC ORCHESTRAL MUSIC)

It's a rare and dramatic sight,

but this spectacle has a dark side.

but this spectacle has a dark side.

It's hard to imagine a greater concentration

of hunters anywhere on the planet.

of hunters anywhere on the planet.

Mighty animals feeding on everything that's slopping out of the nets,

the excess from their catch.

To see all of these animals concentrated in together

To see all of these animals concentrated in together

is just breathtaking.

It's a strange scene,

these great predators feeding on scraps from our nets.

But tempting whales so close to industrial fishing

But tempting whales so close to industrial fishing

can end in disaster.

While we're filming, local marine biologist, Professor Audun Rikardsen,

is alerted to a whale caught up in fishing gear.

is alerted to a whale caught up in fishing gear.

So, you've had a humpback entanglement here.

We had to keep our distance, but you were right in there, involved.

Can you tell us what happened?

Can you tell us what happened?

This whale had something over its snout and through the mouth.

So, it was just laying there,

So, it was just laying there,

and it seems like it was, er, waiting for help.

(WHALE GROANS)

(WHALE GROANS)

And when we came, it came towards us.

So, it was almost like asking for help,

and it was also kind of screaming.

and it was also kind of screaming.

You can hear the sound blowing, "Whoo!"

It was really heart-breaking, honestly.

It touches you when you see that.

It touches you when you see that.

And you really wanted to help.

(WHALE GROANS)

Horribly entangled,

she couldn't dive or feed.

she couldn't dive or feed.

(WHALE WHOOPS)

Time was running out.

Time was running out.

(WHALE WHOOPS)

But to free a frightened whale is a serious business.

But to free a frightened whale is a serious business.

(WHALE SQUEAKS)

(WHALE SQUEAKS)

Spooked, she tried to flee.

With darkness falling,

it was a race against time.

But finally, the ropes were cut.

But finally, the ropes were cut.

And she was free.

(WHALE GROANS)

For her, it was a lucky escape.

For her, it was a lucky escape.

But for most whales there is no rescue.

For this North Atlantic right whale calf,

For this North Atlantic right whale calf,

being born to an entangled mother

stacked the odds too high against them both.

With less than 350 of her kind left,

every loss is a step towards extinction.

The scale of modern fishing is now immense.

Our fishing activities are one of the biggest threats

to whales and dolphins.

(SEA BIRDS SQUAWKING)

Globally, almost a thousand cetaceans a day

are caught in nets as bycatch.

Ghost nets, lost or discarded fishing gear,

haunt our oceans...

with up to a million tonnes more added every year.

with up to a million tonnes more added every year.

Taking up to 600 years to break down...

..they're not coming out unless we remove them.

There has to be a better way.

(CRASHING WAVES BOOM)

(CRASHING WAVES BOOM)

All around the world

marine reserves are creating whale havens.

marine reserves are creating whale havens.

And I want to see the benefits they can bring.

(URGENT ORCHESTRAL MUSIC)

I'm exploring our oceans to see how whales are trying to get by

I'm exploring our oceans to see how whales are trying to get by

in a world very different from the one they evolved in.

(DOLPHINS CLICKING)

There are places where whales can thrive,

and where they hunt as they once used to.

and where they hunt as they once used to.

This group of islands

was once a centre of commercial whaling.

But they're now a safe haven for whales and their prey -

the Azores.

the Azores.

Where the mid-Atlantic ridge carves the ocean in two,

there are volcanic mountains coming up from thousands of metres of depth.

there are volcanic mountains coming up from thousands of metres of depth.

Oceanic currents drive up nutrients from the deep water

and that creates an explosion of life.

and that creates an explosion of life.

When areas like this are protected,

it can lead to an abundance of fish,

which are, in turn,

which are, in turn,

food for the whales.

And one phenomenon draws them in like nothing else.

In the presence of the right kind of predators,

the shoals of fish coalesce into shimmering bait balls,

targeted from all angles by all the various mighty mouths,

targeted from all angles by all the various mighty mouths,

and they don't hang together for very long.

A bait ball is my best chance of witnessing whales feeding underwater.

A bait ball is my best chance of witnessing whales feeding underwater.

But they can quickly disappear.

So, when one happens,

I have to get in fast.

(CALM PIANO MUSIC)

(CALM PIANO MUSIC)

For these fish, schooling is a vital defence strategy.

For these fish, schooling is a vital defence strategy.

They're obvious targets for predators

like these spotted dolphin.

(DOLPHIN SQUEAKS)

(DOLPHIN SQUEAKS)

But there is safety in numbers.

Each fish marks its neighbour,

keeping a set distance and alignment.

keeping a set distance and alignment.

For this lone dolphin,

it's a tricky moving target.

it's a tricky moving target.

One reacting fish triggers the whole school

to shift in unison.

to shift in unison.

This dazzling effect makes it hard to pick out any individual.

This dazzling effect makes it hard to pick out any individual.

(DOLPHINS CLICKING AND SQUEAKING)

(DOLPHINS CLICKING AND SQUEAKING)

The shifting, silvery shoals of fish,

The shifting, silvery shoals of fish,

which just move like quicksilver,

are designed to throw off the smaller predators,

are designed to throw off the smaller predators,

but having all of those creatures concentrated together

in one ball makes them easy prey for the whales.

in one ball makes them easy prey for the whales.

And they're bringing in true leviathans.

And they're bringing in true leviathans.

Sei whales.

They can reach lengths of almost 20 metres

and weigh up to 45 tonnes.

and weigh up to 45 tonnes.

It's in the same animal group as the blue whale,

and shares much in common.

They're long, streamlined, sleek,

They're long, streamlined, sleek,

impossibly fast through the water,

and they're also one of the largest creatures in our seas.

and they're also one of the largest creatures in our seas.

But to really appreciate their hunting skills,

I need to see what's going on beneath the waves.

I need to see what's going on beneath the waves.

(DOLPHINS CLICKING)

(SERENE ORCHESTRAL MUSIC)

(SERENE ORCHESTRAL MUSIC)

(MUSIC BUILDS IN INTENSITY)

Like submarines, they pass with deceptive speed.

Like submarines, they pass with deceptive speed.

It's ominous and awe-inspiring in equal measure.

Wow!

That was incredible.

That was incredible.

The sei whale is one of the very fastest of the cetaceans,

and underwater there's barely any sense of motion

and underwater there's barely any sense of motion

as they go through the water, but when you're close to them,

the wake just tosses you around like you're in a washing machine.

the wake just tosses you around like you're in a washing machine.

Sei whales have been clocked at nearly 50 kilometres per hour,

and this speed is key to their hunting strategy -

and this speed is key to their hunting strategy -

lunge feeding.

A sprint enables them to ambush the fish.

A sprint enables them to ambush the fish.

This sei whale needs to eat close to a tonne of fish every day.

This sei whale needs to eat close to a tonne of fish every day.

Bait balls offer a focused target.

But accelerating 45 tonnes of whale to top speed...

But accelerating 45 tonnes of whale to top speed...

..takes a lot of energy.

They can only use this technique in places where there are enough fish

to make the sprint worthwhile.

to make the sprint worthwhile.

This is extraordinary.

I've never been somewhere where you're genuinely at risk

of getting run over by a whale.

of getting run over by a whale.

Oh!

Look at that.

Honestly, I could stay in there all week

Honestly, I could stay in there all week

with that amount of life kicking off.

Apart from anything else,

Apart from anything else,

it's just a sign of what a healthy looking marine ecosystem

should look like.

You've got everything from the primary producers at the bottom,

You've got everything from the primary producers at the bottom,

the plankton, the zooplankton,

the smaller fish that feed on it,

all the way up to the biggest creatures

all the way up to the biggest creatures

ever known to have lived on our planet,

and they're all focused here.

This is what protection can do,

This is what protection can do,

this is what sanctuaries can achieve.

When you protect waters,

they turn into abundant focuses of life like this.

they turn into abundant focuses of life like this.

These precious moments are a glimpse of how the world could be...

These precious moments are a glimpse of how the world could be...

..if we didn't empty the seas of life.

And The Azores is not the only place

where healthy feeding spectacles can be seen.

Off the coast of South Africa,

new gatherings of whales are giving us a vision of a better future.

new gatherings of whales are giving us a vision of a better future.

Since we stopped hunting them,

Since we stopped hunting them,

humpback whales have made a remarkable comeback.

(WHALES HOOTING)

There's far more work to do,

but sights like this are increasing,

and what we're now learning is that whales help remove carbon

and what we're now learning is that whales help remove carbon

from the atmosphere.

Fertilising plant plankton,

storing carbon in their vast bodies,

storing carbon in their vast bodies,

they soak up almost 30 million tonnes every year...

..as much as a billion trees.

..as much as a billion trees.

Whales are an integral part of keeping our oceans healthy...

Whales are an integral part of keeping our oceans healthy...

..and healthy oceans are vital to combat climate change.

It's now up to us to take action to choose our future.

What's needed now more than ever

What's needed now more than ever

is better protection from the unintended consequences

of our fishing activities.

Once, the call was to "save the whale,"

Once, the call was to "save the whale,"

but now we know we have to save the whales' whole world,

and our very future depends on it.

and our very future depends on it.

To discover how whales are coping in our modern world,

we wanted to observe these ocean hunters in their world.

we wanted to observe these ocean hunters in their world.

(ORCA CHIRRUPS)

And the best way to film this was to start with their food.

Which would mean pushing our diving and filming techniques to the limit.

In Arctic Norway, our attempt to film interactions

between whales and herring boats

meant a dangerous night dive as the boats set their nets.

meant a dangerous night dive as the boats set their nets.

There's a huge amount goes into the safety for diving like this.

There's a huge amount goes into the safety for diving like this.

I mean, first of all, you're diving in Arctic waters

where the temperatures can be below freezing.

But we're gonna be doing this with orca, humpback whales,

But we're gonna be doing this with orca, humpback whales,

the nets and the fishing as well.

Yeah, I'd be lying if I said I wasn't nervous.

Yeah, I'd be lying if I said I wasn't nervous.

(EDGY MUSIC)

'As darkness fell, we prepared for blackwater diving.

'As darkness fell, we prepared for blackwater diving.

'Unable to see beyond your torch beam,

'it's a bit like being in space.

'it's a bit like being in space.

'It's incredibly disorientating.'

We're excited, but at the same time,

never losing sight of the fact that this is about as dangerous

never losing sight of the fact that this is about as dangerous

as wildlife filming dives get,

and everything has to be done right.

MAN: Don't rush anyone. Take your time.

MAN: Don't rush anyone. Take your time.

MAN 2: Just, er, waiting on contact, er, with the fishing vessel.

'At last, just before dawn, we get the go-ahead.'

OK, guys, so we can dive.

All OK, happy? One going in.

Nice one, Steve.

Nice one, Steve.

Two divers in. Get a safety diver in.

(SEAGULLS SHRIEKING)

Diver one, diver two, can you all hear me?

"This is diver Steve to surface. I can read you loud and clear."

"This is diver Steve to surface. I can read you loud and clear."

Capturing the scale of fish spilling out from the nets

showed exactly why whales are changing their behaviour

showed exactly why whales are changing their behaviour

and being drawn to the boats.

And what we saw was even more impressive

And what we saw was even more impressive

than we'd expected.

This is, to my mind,

This is, to my mind,

the most creative of all predators on our planet.

They have the ability to adapt to their environment,

They have the ability to adapt to their environment,

to take advantage of any resource that comes their way,

and here the enormous abundance of herring

is feeding 80 orca in one single feeding.

In Norway, we could use the herring boats to find the whales.

In Norway, we could use the herring boats to find the whales.

But in the Azores, speedy bait balls hunted by even faster sei whales

But in the Azores, speedy bait balls hunted by even faster sei whales

demanded a far more dynamic approach.

MAN: Bait is at 11 o'clock. Yeah.

Shall we go?

Shall we go?

'This time, we're free diving.

'Diving on a single breath, without bulky scuba gear,

'we're more responsive and faster in the water.

'we're more responsive and faster in the water.

'And we minimise disturbance to the animals in this protected habitat.

'We can't know in advance which bait balls the whales will target,

'but with so much life, the prospects look good.'

'but with so much life, the prospects look good.'

The amount of whales and dolphins here is phenomenal.

The amount of whales and dolphins here is phenomenal.

Just phenomenal.

So, yeah, we need to focus on the fish and everything else will follow.

So, yeah, we need to focus on the fish and everything else will follow.

Sighting a whale is a start, though we need to be closer.

It's so exciting, but also utterly exhausting,

just in and out the water over and over again,

just in and out the water over and over again,

trying to keep up with the fish which are moving at lighting speed.

Oh, wow, out there, yes!

Yeah, we have it, the epicentre of our bait ball,

Yeah, we have it, the epicentre of our bait ball,

which is exactly what we've been hoping for!

And finally, following the food pays off.

We catch up with one of the fastest whales on the planet,

taking advantage of the food available in these productive waters.

taking advantage of the food available in these productive waters.

Wow! Wow!

Wow! Wow!

Utterly, utterly jaw-dropping.

I never in a million years expected to get that close to a sei whale.

I never in a million years expected to get that close to a sei whale.

That's one of the craziest things that's ever happened to me. Ha ha ha.

From the Arctic to the tropics,

adapting our filming to each ocean hunter

helped reveal the challenges they face in our modern world,

helped reveal the challenges they face in our modern world,

and what needs to be done to ensure their future.

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