Original subtitles

Narrator: In australia, the sharkiest place on earth,

scientists make an astonishing discovery.

There's not one population of great whites down under,

there's two.

Man: Whoa, oh, oh, oh!

Narrator: And one...

Man: That is a much different face,

look at that.

Narrator: ...Appears way more deadly than the other.

A little terrifying, to be honest.

Narrator: Now experts are asking,

could it be a super predator?

♪♪

to find out, they put the two shark tribes head to head...

♪♪

...In a great white face off.

Man: Wow.

Narrator: Buckle up.

4,000!

Narrator: It's double trouble down under.

-- Captions by vitac -- www.Vitac.Com

captions paid for by discovery communications

♪♪

australia's apex predator --

the great white shark.

Around 7,000 of them patrol the oceans down under.

[ sirens wailing ]

beneath the water's surface, a deadly mystery is unfolding.

♪♪

and it's caught the attention

of shark encounter survivor paul de gelder.

♪♪

de gelder: We've stumbled upon a really curious mystery here

in australia with the great white sharks.

We've been looking at the stats and we noticed that there's way

more deaths on the west coast of australia than on the east.

And I mean way more, a lot.

Now, we don't really know why that is.

Narrator: Since 2000,

there have been just four human fatalities

in the east compared to a staggering 22 in the west,

that's almost six times the number of dead.

While it's known that great whites don't target humans,

and deaths are tragic accidents,

the disparity between east and west leaves paul baffled.

Doesn't make sense to me why the great whites

on the west coast are creating more fatalities.

It just -- it boggles the mind.

Narrator: A scientific discovery could offer a clue.

Until 10,000 years ago,

australia was connected to the island of tasmania

by a land bridge separating great white sharks

on the east and west.

When the ice age ended, the ocean levels rose,

allowing the two groups to mingle.

But they chose not to.

And even today, they're genetically different,

begging the question,

did one evolve to be more lethal than the other?

The discovery that there's two distinct populations

of great white sharks in australian waters

throws a whole new light onto our investigation here.

So I'm teaming up with my friend riley elliot.

He's a shark scientist from new zealand.

We're gonna try and get to the bottom of this mystery,

learn how to keep these sharks safe,

but at the same time, learn how to keep us safe.

Hello, mate.

Ah, good to see you again.

You good? -Yeah, man, great.

De gelder: We've got a mystery to solve.

We've got an adventure to have.

Elliott: You know, it's really a compare and contrast.

Other great whites on the west coast, super sharks,

are they more aggressive? Are they more powerful?

The answer's out there. We just gotta get to it.

♪♪

narrator: Paul and riley's investigation

starts at australia's foster bay,

where they meet up with shark scientist dr. Paul butcher

to gather evidence on the east coast

great white tribe.

-How you doing, mate? -Good.

Nice to finally meet you.

Butch uses smart drumlines

to catch, tag, and track great whites.

Elliott: What I like about smart drumlines

is we're actually learning more about sharks.

We're coexisting through science.

Narrator: When a shark takes the bait,

a gps sends a message to butch's phone.

Butcher: Four years worth of tagging,

450 odd white sharks

we've caught along the entire coast.

-450? -What?

As a scientist, that is a data city dream.

[ beeping ]

I hear your phone popping off.

And that's my message now.

Elliott: Oh, man, I'm excited.

Got a bite, got a bite.

I'm pumped, bro.

♪♪

there's a white shark.

Oh, beautiful.

Oh!

They're such amazing animals.

Narrator: It's a juvenile around nine feet long,

hunting only yards from a busy beach.

Wow.

This is only fractionally smaller

than the shark that attacked me.

They've modeled actually the bite force

of a juvenile like this.

And it came in about half that of an african lion,

which is no small -- no small bite.

They still crush bones.

Narrator: The shark is measured, tagged, and released.

-Ready? -Oh!

-Wow! -Whoo-hoo!

Good job.

Narrator: A quick reset and right away,

they're back in business

and now there's a shark within two minutes.

That's moving -- -we're on again.

So we're just set back here. -What!

I can't believe that!

-This one's a little male. -Yeah.

Kind of blown away by how many of these little white sharks

there are, serious, never seen anything like it.

The average size of our white sharks

that we're catching is around 2 1/2,

2.6 meters. -Wow.

Those elusive adults,

we don't see them, we don't catch,

and we don't tag.

♪♪

bit of a mystery as to why

these big great whites aren't along the coastline here.

Just like any good mystery,

when you start asking one question more pop up.

400 animals have been tagged,

but not one of those is an adult?

Where are the adults?

Narrator: To find out, paul and riley split up.

♪♪

while paul heads west to gather evidence

on the western great white sharks.

♪♪

riley travels over 1,000 miles southeast

to stewart island, off of the tip of new zealand.

♪♪

he believes that the elusive east australian adults

migrate here in summer in search of food.

Elliott: Stewart island's a very unique location.

It's cold, it's in the roaring 40s,

but there's a lot of sea life here.

Really good hunting ground for great white sharks.

Narrator: Seasoned shark cameraman

dave abbott knows these waters

like the back of his hand.

Abbott: Water looks good.

I see albatross around that's always to me, a sign of sharks.

♪♪

a-ha, david, that's a great white

and that's a big one.

This is exactly what we came here for

to try and find the elusive east australian adult sharks.

Whoo-hoo.

It's definitely a lot bigger than what we saw in forster.

That's definitely not a juvenile.

I'm just excited to see how this differs and right now

I can just tell you it's a lot more impressive.

It's a lot bigger.

Oh, jeez.

All day, this is impressive.

It's just circling around, it seems to be standoffish.

I've got a feeling this is another shark, yeah.

They're just sizing each other up,

who's allowed in first?

♪♪

oh!

♪♪

oh, jeez, that is a much different face. Look at that.

Jeez!

♪♪

oh, oh, oh!

Wow.

Let's get in there, dave.

♪♪

what ultimately want to know is

are the adult east australian great white sharks here?

Narrator: There's only one way to know for sure.

Find one that bears one of butch's tags.

♪♪

within minutes, the water is swarming with great whites.

Whoa!

Amidst the chaos, riley can't make out a tag.

Elliott: Whoa!

Whoa!

Whoa! Oh, oh, oh!

Oh!

Narrator: Then, he spots a juvenile among the giants.

Elliott: Wow.

Narrator: It's the proof he needed.

And there are adults here, too, some up to 18 feet long.

♪♪

elliott: Wow!

Whoo, wow.

It blew me away.

The might, the speed, the power.

One shark did turn up, it had a spot tag.

And this is really the missing link.

Narrator: Riley's in the right place,

let the showdown between east and west begin.

♪♪

coming up, the two tribes go head to head...

Wow...

Narrator: ...To find out if the western sharks

are super predators.

And riley makes a sensational scientific discovery.

Whoa, oh, oh, oh!

Narrator: Beneath the surface of australia's oceans

lurk two separate populations of great white sharks.

Statistics show that in accidental encounters

with humans, western great whites

are almost six times more deadly and their eastern cousins.

Could they be some kind of super predator?

De gelder: Are the western sharks bigger?

Are they more aggressive?

Or is there something we don't yet understand going on?

Narrator: To find out,

paul de gelder and riley elliott

will pit the two shark tribes against each other.

The categories for testing will be size,

bite force,

and hunting behavior.

Riley's already located his eastern adults

at stewart island.

Now, paul's hunting for the deadly western great whites

at the neptune islands

where he teams up with shark scientist

dr. Charlie huveneers.

Charlie's research involves tagging

and tracking these predators.

-Yes, yes. -Yeah.

-All right. -We got him.

Narrator: Data shows that the same western whites

return here regularly,

with some arriving at almost exactly the same time each year.

There's fur seals, the sea lions,

so the sharks here are looking for that fat, juicy food.

♪♪

yeah! [ laughs ]

first shark of the trip.

Narrator: These western whites appear

to be more lethal than their eastern cousins.

Look at that power.

Narrator: Could that be, because they are bigger sharks?

Time for test number one -- size.

Yeah, let's get in the water.

♪♪

I'm gonna jump in the cage now

and I'm gonna utilize this really great piece of technology

we've got called a stereo camera

that accurately measures the length of every shark.

So this is really important because we want to document

how large these sharks are out here on the west side

and compare them to the east.

♪♪

narrator: Paul's goal is to measure

the biggest shark he can find.

Wow.

Whoo-hoo-hoo-hoo!

Narrator: Software factors in the distance

between the two cameras, then aligns the images

to accurately measure the size of the shark.

♪♪

paul captures a range of great whites.

And the winner is almost 15 feet long

about the length of an suv.

♪♪

that was awesome.

As soon as we got down there, he came straight up to the cage,

had a little nibble, his face was right here.

It was amazing, so inquisitive.

A little aggressive, a little terrifying, to be honest.

♪♪

what a shark.

♪♪

narrator: Back at stewart island,

riley prepares to find out

how the eastern whites measure up using laser cam technology.

So on the shark and basically as I swim by,

you can get these lasers on me.

Narrator: Two parallel beams exactly one foot apart,

work like an underwater ruler.

When we take a still grab from your video.

There's a 12-inch ruler that's on the shark

and we can extrapolate how big the shark actually is.

Yeah.

♪♪

narrator: Riley's plan -- head to the ocean floor,

where he hopes the largest sharks are lurking.

♪♪

elliott: One, you gotta put that cage on the bottom

in one of the most notorious areas of the world

for aggressive and high numbers of great white sharks.

It's probably the most dangerous aspect of this trip.

♪♪

narrator: Giants close in on the cage one by one.

Then suddenly, the water clears.

♪♪

♪♪

whoa!

Narrator: Measurements in the back,

they resurface to study the data.

Oh, dave, that was incredible.

It's very much stepping into their world, wasn't it?

Yeah... [ speaks indistinctly ]

oh.

Oh, nice data, there's a great one.

Look, you can see these lasers perfectly.

Oh, nice.

There we go. There's that big female.

Beautiful girl.

That shark's 5.1 meters.

I mean, that there is a mature female great white shark.

She's likely 35 to 50 years old. Truly an incredible animal.

Narrator: Riley's shark beats paul's for size.

It's clear the eastern great whites

are every bit as big as their western cousins.

So why do western sharks account for almost six times

more accidental human deaths?

Coming up,

two tribes in the great white bite off.

4,000! And he's gonna tell them that.

Oh, jeez!

Narrator: And a jaw-dropping discovery.

Man: Whoo-hoo-hoo!

♪♪

man: Wow.

Narrator: In australia,

a study has revealed two tribes of great white sharks.

Elliott: Whoa!

Those in the west appear to be more deadly

than those in the east.

To find out why

experts put together a white shark showdown.

The first test ruled out size as a factor.

So could the difference lie in the power of their jaws?

Elliott: Do they have sharper teeth, bigger teeth,

larger jaw structure.

The only way to really tell is to get as close

as I can to the sharp end of the shark.

Narrator: Time for test number two -- bite force.

♪♪

so what I've got here is a bite meter.

This is some high density foam with some sensors in here

that simply measure downward pressure.

And obviously in this case, that's the jaws of the shark.

So is charlie and paul doing the same thing

in west australia?

Yeah, they have the exact same device as this.

♪♪

bombs away.

♪♪

here it comes. He's looking at it.

Narrator: Using tuna,

dave tempts a big male towards the bite pad.

Oh, there it is. It's coming in.

Oh, oh, oh, jeez.

Just wait for a second, if it turns back.

♪♪

oh! Jeez!

Almost, davey, almost.

Narrator: While riley struggles to get a bite,

in australia's neptune islands,

shark attack survivor paul de gelder goes fishing

for a western white.

This bite pad data is really interesting to me,

especially on a personal level,

because when the bull shark bit me in sydney harbor,

the first thing I remember feeling

was that immense pressure.

So to get a clear indication of how much actual bite force

these great white sharks have,

I think that's really gonna blow me away.

This information is going to give us more data

so that we can accurately create better shark mitigation policies

to protect sharks and humans and that's the main goal.

We've got a decent sized shark coming up to visit.

[ speaks indistinctly ]

no.

He's made a few passes on the bite pad,

but he hasn't quite grabbed it yet.

Yes, yes, yes.

Oh.

♪♪

here we go. Here we go.

Yep, coming through the pad.

Yep, really close, really close.

-Oh! -Yep, yep, yep, yep.

Whoo-hoo-hoo-hoo.

Yes! Yay!

♪♪

yeah!

That's what we want, buddy, yeah.

-Finally we got one. -Yeah.

Whoo-hoo.

So we just got a reading on the bite pad.

And look, I'm no scientist, but I'm pretty sure

that was strong enough to bite through a human limb.

♪♪

predictive model for three and a half meter shark

was about 2,000 newton to a 6,000 newtons --

mm-hmm.

...And the bite that we got from about a similar size shark's

was between 3,000 and 4,000 newtons.

Narrator: At that reading, each bite is like being hit

with the force of a charging bull.

And one of these bites registered at more than

4,500 newtons, which is a lot.

Yeah, that's a big bite.

Narrator: So do eastern whites cause

fewer human fatalities because they have a weaker bite?

Elliott: Oh, might turn back on it.

Narrator: Back at stewart island.

Riley is about to find out.

♪♪

oh, dave, yes!

♪♪

2,000!

♪♪

2,500! 4,000!

Oh, jeez!

4,300.

Oh, man, he's got a tail on that.

4,600.

♪♪

and now he's off. Oh.

What have we got? Oh, oh, oh, oh!

Oh, my god. -[ laughs ]

wow, I don't even think I need to actually look back

at the measurements. That is intense.

I mean.

There's no doubt that the great white sharks from east australia

definitely have bite to them.

The numbers there when he first got purchase,

he bit, you know, at the start here.

Yeah, with the tip of their mouth,

at anterior part of their mouth, that was 1,200.

He started getting purchase, it just skyrocketed.

When I pushed peak here, the peak here was 4,600 newtons.

We put that into pounds,

it's about 1,000 pounds of pressure.

Narrator: Test number two is a photo finish.

Similar size sharks, almost identical bite power.

Clearly, there's no difference in the bite force of sharks

from east australia or western australia,

but there is a significant difference

in the statistics of fatalities.

So there's more to uncover.

We just got to keep looking for it.

Narrator: Size and bite force tests

reveal no big difference between the two tribes.

So could it all come down to hunting behavior?

Are western great whites a more calculated,

ruthless predator?

For me, that's the big question.

Narrator: Scientists have discovered

two different tribes of great whites in australia --

east coast and west coast.

Paul de gelder and riley elliott are trying to discover

why the western sharks are apparently

more deadly to humans.

Size and bite force tests have shown both tribes

to be equally fearsome.

Elliott: Oh, man, he's got a tell on that.

Now this one final test -- hunting behavior.

Elliott: Is the way the great whites hunt

on the east different from on the west?

♪♪

narrator: In the neptune islands,

paul, studying the western whites' predation techniques.

De gelder: This is great watching these mature sharks.

You just don't see 'em for a while.

They disappear,

and then all of a sudden,

they just charge in, take the bait.

It's really awesome to watch from the surface.

They just come out of nowhere.

Narrator: To get a closer view of their ambush attack method,

paul all breaks out a shark's-eye-view.

A tag equipped with a camera and accelerometer

to capture sudden bursts of speed.

So the shark's-eye-view is going to give us a clearer picture

of how they're hunting in this area?

Exactly. If you only get the acceleration,

you don't really know what they're doing.

You know they're accelerating, but you don't know what for.

♪♪

narrator: To attach the tag to its fin,

they'll need to bring the shark right up to the boat.

De gelder: Getting a fin cam on the back of a great white shark

is always a challenge, but the data that you get from that,

the p.O.V. Is just such a wealth of knowledge,

it's so worth it to get it done.

On the left. On the left. Yep. Yep. Yep. Yep. Yep.

-Yeah! -Got it!

[ all cheering ]

de gelder: 48 hours, that's gonna pop off.

We'll retrieve it and be able to plug it into the computer

and check out the footage.

Narrator: Two days later, they retrieve the camera.

♪♪

all right, mate. What have we got?

Huveneers: We can see the footage from the camera.

Awesome.

The western great white begins by cruising the shallow reefs.

♪♪

then it goes deep.

♪♪

when it spots something on the surface,

there is a burst of speed...

♪♪

...As it ambushes its prey.

♪♪

de gelder: What the sharks are doing here is they're going to the bottom,

planning their strategy and then just exploding

to the surface with killing it in mind.

Narrator: Calculated, committed, clinical.

♪♪

what's more, tracking data

shows these sharks migrate

between the remote neptunes

and australia's west coast population centers.

De gelder: These sharks will soon be going up the west coast

and they're going to be very hungry from their long swim,

looking for appraisals.

Narrator: Seal colonies await, but so do surfers.

Anyone mistaken for food would stand little chance.

♪♪

de gelder: These are large adult white sharks,

and that could be one of the main reasons

why we're having so many fatalities on the west coast.

So do riley's eastern great whites

have a different technique,

one less lethal to humans?

Elliott: Are the east coast sharks here on stewart island

predating in a way that's as committed as on the west?

Or it's a different hunting tactic?

Narrator: To get to the bottom of it,

riley heads back to the ocean floor

in search of the biggest predators.

♪♪

but then riley witnesses something extraordinary.

Could this be a breeding ground?

♪♪

witnessing great white mating

is the elusive holy grail of shark science.

This might be as close as anyone's ever gotten.

Elliott: [ laughs ]

while riley is focused on this unique behavior,

the mood in the water suddenly changes.

♪♪

[ static ]

♪♪

narrator: Riley eliot and dave abbott are at the bottom

of the ocean gathering evidence on how eastern great whites hunt

when their cage starts to tip.

♪♪

just in time, it rights itself.

But the sharks continue to swarm.

♪♪

with adults and juveniles in one place,

riley's team invites them to hunt.

♪♪

just weeks ago, really found australia's east coast

teeming with juveniles and sub-adults like these.

They close in at surface level,

nipping at their prey with short, sharp bites.

A human might survive these sorts of exploratory bites.

But down below, the huge sharks are lurking...

...Eyeing the bait.

Elliott: Oh! [ chuckles ]

whoa!

[ chuckles ]

[ chuckles ]

narrator: These eastern adults hunt just as aggressively

as paul's western great whites.

♪♪

they are just as big, their jaws just as strong.

Two populations, but one species.

In the great battle of east versus west,

it's a dead heat.

I can't believe it. I honestly can't believe that.

It's awesome, isn't it?

[ laughs ] that was insane, man.

♪♪

oh, mate.

It's like a freight train of sharks for a little while there, wasn't it?

That's the largest array

of great white sharks I've ever seen.

And look -- that is a rare thing to see anywhere on earth.

So much unique. It's unique, I feel.

I feel like that was something really special.

I was blown away, how obvious the difference

between juvenile behavior, sub-adult behavior,

and adult white shark behavior is.

All those younger animals will come in right up at the surface,

swimming slowly in clear view,

and kind of miss things, nibble on things,

versus the mature sharks are very much on the bottom,

stealthy and slow.

And then you see them look up,

and what they want, bang!

♪♪

and that was the big standout difference

between that adult shark and the sub-adult sharks,

and I think that is literally the point of fatality.

[ chuckles ]

♪♪

it's the end of an investigation

that has its starting point millions of years ago,

when two tribes of great white sharks evolved separately.

Today, they record different rates of human fatalities.

But it's not because one tribe is more deadly than the other.

It's likely the age of the sharks that come in-shore.

We set out to investigate

why the great white sharks on the west coast

seem to be more lethal to humans than the sharks on the east.

What we've discovered on the east coast

is a much larger population of young white sharks.

These sharks are more likely to bite,

but less likely to kill.

Narrator: On the west, large colonies of seals

attract the big sharks into coastal waters,

where humans recreate.

De gelder: These are the perfect conditions

for a deep water ambush,

and if the surfer gets in the way...

It's all over.

Narrator: Paul and riley's findings can reduce the risk

if we understand and respect the realm of the great white.

Elliott: This is a marine environment where the top predator roams.

If we go there to recreate,

we must understand the environments we go into.

We must understand the risk.

Elliott: To the next one, eh?

De gelder: Let's go find some sharks somewhere else.

[ laughs ]