Original subtitles

NARRATOR: Two apex predators dominate the ocean,

the great white shark, a lone hunter.

And the orca, known as the killer whale.

Both sit atop the oceanic food chain so when orca begin to

hunt great white sharks in South Africa,

it's big news.

Experts want to know will it happen again,

and if so where?

(theme music plays)

It's happened before,

orca have hunted and killed great white sharks.

One of the first reported cases off the coast of

California in 1997.

And again in 2017 off South Africa.

Five dead white sharks washed ashore.

Shark scientists wondered why orca would hunt dangerous prey

like a white shark.

With attacks happening in oceans around the world,

experts are looking for similarities and patterns,

and what the effect would be on the marine ecosystem.

Particularly in New Zealand.

KINA: When the orca started to kill the great white sharks in South Africa,

the rest of the sharks actually disappeared

and haven't come back for years.

If that happened in New Zealand,

not only would we lose this population of great whites

that we've learned so much about but it would also be

disastrous for this ecosystem to lose

an apex predator like that.

NARRATOR: There are several theories about exactly why

the sharks vanished.

But the coincidence of the orca attacks

and the disappearance of the sharks is hard to ignore.

And there's a lot at stake,

including the health of the marine ecosystem.

New Zealand has a local orca population

of between 150 and 200.

While the white shark aggregation is one of the

largest in the world.

Estimated to be over 5,000.

If the orca begin to go after white sharks here,

they have plenty to choose from.

New Zealanders Kina Scollay and Dr. Ingrid Visser

are investigating.

Orca could be hunting great white sharks already.

But no white sharks have washed up

on New Zealand beaches.

So, they're searching for other signs of orca predation.

Any strange behavior, wounds from an encounter,

anything that points to orca hunting white sharks.

INGRID: I'm coming down the port side.

KINA: Roger.

It really is interesting, Ingrid. What do you think?

NARRATOR: Local great whites are in New Zealand waters from

December to June, when many will leave on their

annual 2,000 mile migration, to the coast of Australia,

and the Tropical Pacific.

Local orca, on the other hand, remain in New Zealand waters all year round,

roaming the coastline in search of prey.

Ingrid is New Zealand's top orca specialist.

But today is her first dive with great white sharks.

KINA: I'm pretty psyched to get you in a cage with, uh,

my favorite population of great white sharks in the world.

INGRID: I have to admit, I'm pretty pumped about it myself, that's for sure!

Wow!

KINA: What do you think?

INGRID: It's pretty amazing, Kina, to see New Zealand sharks this close.

I really expected to be quite scared, but

in the safety of the cage here, it's quite impressive to just watch them

doing their great white shark thing, right?

Wow!

He snuck up on us!

KINA: That's their specialty!

NARRATOR: Great white sharks in this area are curious and aggressive,

which makes them dangerous.

Orca and white sharks have shared the top of the ocean

food chain for millions of years.

So why would orca attack great whites like these now?

INGRID: Even though orca are the largest of the

dolphin family and they can be friendly,

we still have to consider that they are one of the top

predators of the ocean.

NARRATOR: Ingrid's research tracks the 200 or so orca

living in New Zealand's waters.

INGRID: Yeah, I know, big guy! Hang in there.

The exciting thing about this adventure for me is that we've

got two top predators, and we don't really know

what's happening between them.

NARRATOR: Orca and white sharks are the top

two ocean predators.

Yet they're fundamentally different.

Orca are air-breathing mammals.

White sharks are water-breathing fish.

Orcas live in pods of up to 40,

made up of individual family units that remain together

for life and hunt cooperatively.

Some new research suggests white sharks may occasionally

hunt in groups.

But they tend to hunt alone.

The largest great white ever recorded measured over 20 feet

and weighed 5,000 pounds.

Small for an orca.

Killer whales can grow to 30 feet or more.

And weigh as much as 20,000 pounds.

But as different as they are,

orca and great whites are both sophisticated,

tough, and hungry predators.

KINA: Whoa, this is a big animal.

NARRATOR: Kina and Ingrid dive again and again.

Searching for evidence.

KINA: Well, that was a pretty amazing interaction, Ingrid!

Those two sharks actually physically bumped into each other!

Nobody wanted to back down, and they were leaning

pectoral fin onto pectoral fin. That's quite a sight!

INGRID: I think this was more of a, you know, "get out of my territory" interaction.

I don't doubt that if the orca were going to take on one of these great white sharks,

they would be thinking very carefully about it before they did.

There wouldn't be a mistake, and it wouldn't be something

that they would take on lightly.

Yeah, there seems to be a very strong hierarchy going on here.

When you see that with orca, it's usually a nice social interaction.

It really is an impressive, predator on predator interaction, that's for sure.

NARRATOR: In 2017,

a predator-on-predator interaction of another kind

took place along the coast of South Africa.

Five dead great white sharks washed up on local beaches.

The news is shocking.

Scientists conducted an investigation.

Of all the evidence collected, it was the bite marks on the

shark bodies that revealed the killers.

The teeth marks belonged to orca.

Stranger still, the killer whales had taken only

the shark livers and left the rest of the bodies untouched.

This was the first recorded case of orcas killing

white sharks in South Africa.

Shark and orca scientists wondered when and where it

might happen again.

INGRID: We can't rule out that the orca here in New Zealand

could hunt great white sharks in exactly the same way.

NARRATOR: The Foveaux Strait sits at the southern end

of New Zealand.

Over 6,000 miles to the east of South Africa.

Both regions have large populations of great whites

and roaming pods of orca.

A combination that resulted in a fatal confrontation

in South Africa.

And if white sharks and orca ever cross paths in New Zealand,

this is where it could happen,

in the Foveaux Strait.

♪ ♪

KINA: We've got a couple of good players here.

There's two sharks that are pretty boisterous.

It's pretty cool!

NARRATOR: Large, boisterous,

and aggressive great white sharks.

What possible motive could an orca have for attacking

a great white?

There isn't a clear answer.

But to Ingrid, it makes some sense.

INGRID (off-screen): Typically, in New Zealand,

the orcas are not just targeting prey to take

the whole thing.

They're focused on particular parts of them

and that's the liver!

NARRATOR: When the South African orcas killed the great whites,

this is what they did.

Hunting for liver with great precision.

Liver is a prize for any predator.

To hunt, mate, and migrate thousands of miles,

takes energy.

Liver is pure fuel.

So when they hunt, they're filling the tank.

New Zealand orca feed on the 25 species of rays and

skates that swim in local waters.

The preference for rays is unique to orca in New Zealand.

But recently local orca have acquired

a taste for shark liver.

From a smaller cousin of the great white, the sevengill.

And evidence suggests South African orca

started on sevengill sharks

and graduated to great whites.

NARRATOR: Ingrid Visser and Kina Scollay are looking for

evidence that orca are hunting great white sharks

in New Zealand waters.

Ingrid has evidence that there's a disturbing pattern

in orca hunting.

New Zealand orca are hunting sevengill sharks,

just like the South African orca.

Sevengill sharks grow to nine feet long and 200 pounds.

A much larger meal for an orca than a small ray.

But the sevengill shark is no easy prey.

INGRID: Sevengills are relatively new on the orca menu,

but I've seen it a few times now.

INGRID (off-screen): You see the orca, and they're very,

very precise in how they do it.

I've got footage of the orca with the sevengills where

they've ripped the pectoral fin,

right under the pectoral girdle there.

KINA (off-screen): Right.

INGRID: And they've extracted the liver.

WOMAN (off-screen): Wee! Oh, there's a shark.

WOMAN (off-screen): Oh, shark. Shark.

INGRID (off-screen): One of the things I find fascinating is how the

sevengills will actually turn and defend themselves

against the orca.

The way the orca hunt the sevengills

is pretty impressive.

First of all they'll come in and they'll karate chop the shark,

so they'll just come and lift their tail up and

whack them on the back.

Then they grab the sharks by the pectoral fin and rip them

open and pull the livers out.

NARRATOR: Ingrid captured rare footage of orcas hunting

sevengills in Northern New Zealand.

♪ ♪

Their precision in hunting for shark liver is clear.

KINA (off-screen): What's really fascinating is that in South Africa,

the orca started by hunting sevengills,

and then they moved on to the great white sharks.

So knowing what's gone on in South Africa,

what concerns me is exactly the same thing could happen here.

NARRATOR: A concentration of sevengill sharks lives up

along the western coast of New Zealand.

Kina has dived with them for years,

knows just where they live, and how they behave.

KINA (over radio): Beautiful.

NARRATOR: They decide to drop in and see if the sevengills

can give them any clues.

Fiordland National Park is a vast,

remote wilderness on the western shore

of New Zealand's south island.

Most areas are accessible only by helicopter or boat.

KINA (over radio): You know really,

you fly over these mountains and

you're in a completely different world,

and then under the water,

it's completely different again.

Different to just about anywhere else you'll dive.

Amazing.

NARRATOR: These deep fiords are murky,

stained with tannins from the ancient forest.

It makes the water dark, even in the middle of the day.

If orcas came here to hunt sevengills,

it's possible no one would ever know.

KINA (over radio): I actually haven't been in here for about two years.

INGRID (over radio): Wow.

KINA (over radio): And that's after diving here month in,

month out for many years, and I really felt like

I knew these sevengills so well.

All this talk about orca eating them,

I just kind of want to come and have a look.

INGRID (over radio): Yeah.

Absolutely Kina, and I mean look,

that ties in with the sightings we've had recently

of the orca coming down this bit of coastline,

so I'd be fascinated to know if they're coming up here

to your sevengills.

NARRATOR: The only place for Kina and Ingrid to land is on

a small fishing trawler, in the middle of nowhere.

KINA (off-screen): My little secret spot is only just literally one

minute's flying time from here,

so I think it's easiest if I gear up here.

INGRID (off-screen): Right. Yeah.

KINA (off-screen): And then I'm gonna hop in the helicopter,

just buzz around there and bomb in!

♪ ♪

NARRATOR: Diving without a cage,

Kina will have to be careful of the sevengills

and keep an eye out for orca.

They could be anywhere.

NARRATOR: Kina Scollay is paying a visit to an

aggregation of sevengill sharks in

Fiordland National Park, New Zealand.

And knows just where to find them.

He's looking for any signs that orca are hunting

these sevengill sharks.

♪ ♪

KINA: The murky water really works well for these guys.

You just can't see them coming.

As they're approaching, you just see the

white under their mouth.

Looks like an evil kind of Joker grin.

And then a shark materializes out of the murk.

NARRATOR: The sevengills are here,

drifting in and out of sight.

Checking out the intruder.

KINA: Scientists have found remains of really big animals inside them.

Prey items as big, or bigger, than a human.

And really, the only way they could do this is if they're pack hunting.

When you see one coming out of the murk,

you almost know there'll be another one coming from one side,

and if you look the other way,

there'll be another one sneaking in there, too.

KINA (over radio): Whoa!

KINA: And they're relentless!

Well, it's good to see that these sevengills are here

and up to their usual tricks.

But to be honest,

there's less than I expected to find on this dive.

NARRATOR: Sevengills may be prey for orca,

but these sharks are no pushovers.

KINA: Oh, this one means business!

But it's the ones that sneak up behind that I really have to worry about.

Whoa, I like this guy!

Yeah, these guys are revving up a bit much for me.

I think it's time to get out before they take control of the situation.

That was awesome to go and visit those guys.

INGRID: Yeah, great jump! KINA: Yeah, cheers mate.

KINA (off-screen): That splash and the, and the noise of the helicopter really has to

attract them and they were straight on top of me when I got in,

but not as many as I would've expected to see.

INGRID: Really?

Okay, well that's really interesting because given that

we know historically that orca are coming in here,

and we've had the reports recently,

and now you're seeing less sharks in here too, so,

you know, it's indicative that something's been going on, right?

NARRATOR: Lower sevengill numbers could mean a few

things are going on including predation by larger predators,

like orcas.

That would mark a change in their usual diet.

Traditionally, New Zealand orca hunt the many species

of rays and skates that live in these waters.

Like, all dolphins, they have a special ability to find them.

INGRID: Orca hunt using echolocation,

which is a series of clicks that they send out that bounce

back and give them incredible information.

They can tell even if a shark has a full tummy.

NARRATOR: It works like sonar.

The orca can detect their prey even when it's buried

in the sand.

But, filling up on rays and skates can be hard work

and burn a lot of precious energy.

KINA: All right.

INGRID (off-screen): Do you see them?

Look, they're in a really tight group over here.

Right there.

NARRATOR: Many rays are bottom feeders,

and spend much of their time on or buried in the sandy

ocean floor.

Orca jaws are not designed to grab them off the bottom,

so the orca work together.

Chasing the rays upward and catching them in the open.

But ray hunts don't always go smoothly.

Rays often flee to shallower water,

making it dangerous for the orca.

There is the risk of a fatal stranding

as the tide goes out.

And the ray may still escape.

NARRATOR: When orca hunt rays in New Zealand,

their size is not always an advantage.

♪ ♪

After a lot of work and coordinated effort among several orca,

they catch the ray

but it's a tiny payoff for all that effort.

And compared with white sharks rays are a snack.

One 700-pound great white shark liver could be

equivalent to nearly 175 ray livers.

And it's a lot more work to hunt multiple rays.

While it is more dangerous to hunt a single great white,

it might be worth the risk.

KINA: It's really hard not to think when you see animals

that big that their liver must be

gold to a liver-eating orca.

NARRATOR: A great white liver can grow to 25% of the shark's

total weight.

If a 12-foot great white weighs 1,000 pounds,

it may have a liver weighing 250 pounds.

A big pay-off for the orca.

Kina and Ingrid are off one of the Foveaux Strait's large

colonies of seals.

Over the summer, the white sharks consume many.

Their livers are swollen with seal blubber and oil.

Ingrid and Kina are looking at the length of the sharks

to estimate their liver weight.

INGRID: There's one coming up from the starboard side there.

That's coming right in at us.

How big do you think that one is, Kina?

KINA: See, that male there is quite a bit smaller.

And he's well longer than this cage is wide, so,

probably...

three and a half meters?

It's still three or four times bigger than any of the sevengills

I saw on the dive the other day.

NARRATOR: Great white sharks as prey for anything,

even orca, is hard to fathom.

But the orca may see them that way.

INGRID: All our evidence points to the fact that the

New Zealand orca have a very strong culture of hunting sharks.

INGRID (off-screen): If the rays were removed from the food web here in New Zealand,

chances are the orca would shift their food preferences.

And they could start targeting great white sharks in earnest.

NARRATOR: So far the supply of rays and skates

has been ample.

But add warming oceans to natural fluctuations in all

animal populations and it's hard to predict

what will happen.

INGRID: Looks like the size of a horse.

A shark that size, the liver has to be absolutely huge.

KINA: I think we can pretty accurately say

it's 4.2 meters long, or even a little bit bigger.

And that weighs something like 1200 kilos, or 2500 pounds.

That's a mighty, mighty feed for a

liver-eating orca.

INGRID: I think a shark that size would be a feast for a whole family, mate.

Not just one orca!

Is it just me, Kina, or are the circles that they're making

getting smaller and smaller?

KINA: I think you're dead right, mate.

INGRID: Is it behind us?

Under the boat!

Here he comes again, eh?

NARRATOR: The half dozen white sharks swimming by

are more than impressive.

To an orca, they may represent the food value of 1,000 rays.

KINA: There's another huge one. Here we go!

If that other one that we saw earlier was 4.2 meters,

I would say that she would have to be

well over four and a half meters. Probably close to 15 or 16 feet.

NARRATOR: At 16 feet, this one great white shark alone

is the equivalent of 200 rays to a hungry orca.

It might be a motive for predation.

INGRID: Compared to the size of a ray liver, which is just a few pounds,

a couple of kilos at most, to the size of a liver of these guys,

it's no wonder the orca would want to target them.

KINA (off-screen): It's hard not to think,

an animal as intelligent as the orca,

that they're coming through here at the perfect time

of year, when the livers are fat,

they've gotta see this as a food source.

And even though it's high risk,

we've seen in South Africa that they can decide

it's worth it.

There's such a food source there.

INGRID: Oh, absolutely.

KINA: You've gotta wonder whether they're not already

onto this.

It may have been going on for a long time in New Zealand but

we've just never heard about it.

INGRID: Just, yeah, exactly.

NARRATOR: Ingrid and Kina have found many similarities

between New Zealand and South Africa.

In both places, the orca already have a taste

for sevengill sharks.

But after the orca killed five great whites in South Africa,

all the other white sharks disappeared.

In New Zealand, all of these sharks

are still here and hunting.

Then, like a bolt from the blue,

Kina and Ingrid finally see what they've been looking for.

INGRID: Wow!

That didn't look like shark bites.

KINA: That really is phenomenal!

NARRATOR: Kina and Ingrid are observing local white shark behavior,

when a male with a wound catches their eye.

KINA: Wow!

One has got big, white rake marks on his dorsal.

INGRID: They didn't look like shark bites.

Should have a look and see if it's orca bite marks!

KINA: You're right! That's interesting.

I'll try to get some close shots of it, so we can have a look

later on, see if we can figure out what they are.

INGRID: It's coming up on your left, right there, Kina.

The one with the rake marks.

That's the guy we want. We just want him to come in a bit closer, eh?

NARRATOR: An unusual mark on a white shark's dorsal fin

looks like a bite.

INGRID: He's just swum towards the bow.

He's just coming down the port side of the boat at the moment.

Coming in close now.

Wow!

Those rake marks look really distinctive.

KINA: What were those rake marks on the fin?

That was fascinating.

INGRID: Yeah.

KINA: They were quite wide apart and very straight,

which was interesting.

INGRID (off-screen): Yes.

KINA (off-screen): And those were uniform. That was something new to me.

INGRID: Yeah.

And it looks very similar to what I see in the stingrays

when the orca have been biting them.

You know, you get these sort of like someone's raked the garden,

but it's teeth rake marks,

and that's what it looked like to me.

Yeah, so let me show you these.

This is a picture of an orca's teeth.

See how the teeth curve backwards?

And so here, this is a close up of these teeth marks,

and this is what I think we saw on that great white shark.

KINA (off-screen): Yeah, amazing.

INGRID: And when you look at the scale on here.

KINA: Same thing, that was what we saw on that shark!

INGRID: Matched with what we saw. Yeah.

So if I had to put money on it, I would say it was orca.

KINA (off-screen): Well, I certainly can't think of anything else,

and that is pretty phenomenal.

INGRID (off-screen): Sure.

KINA (off-screen): This could well be the evidence we're looking for.

NARRATOR: The bite marks could be a breakthrough.

The first visible sign of orca-on-white shark predation

they've seen.

Ingrid and Kina devise an experiment that will use sound

instead of sight.

INGRID: Orca use a range of different sounds.

They use clicks for echolocation,

they use whistles and pulsed calls when

they're communicating.

It's really impressive.

NARRATOR: So they'll use recorded whale sounds and

observe how the sharks react.

KINA (off-screen): It's a little known fact about great white sharks that

they actually have amazing hearing.

So I think if the great white sharks react to orca sounds,

that might mean that they've met them before.

How they react could possibly even tell us,

whether that experience was hunting, or otherwise.

So this experiment is going to be very interesting.

NARRATOR: They mount an underwater speaker

on the dive cage.

The plan, play sounds from several other kinds of whales first.

INGRID: Here you go.

NARRATOR: To try and draw the sharks in.

INGRID (off-screen): Oh, that's perfect.

NARRATOR: Once white sharks are around the cage,

Ingrid will play the sounds of New Zealand orcas hunting.

KINA: Done.

It will be interesting to see if they are actually scared of

orca or if they, you know, if they know what it's like

to be scared of something!

♪ ♪

INGRID: Do you copy me, Kina?

KINA: Roger, Ingrid, loud and clear.

I guess we're good to go!

INGRID: Well, look I'm gonna start playing the first set

of sounds now.

This is the humpback whale calls that you recorded.

KINA: Roger that. Go right ahead.

(humpback whale singing over PA)

NARRATOR: This is humpback whale song,

and possibly a great white dinner bell.

White sharks are known to hunt whale calves

in the tropical pacific.

KINA: Well, that certainly got a couple of people interested!

(humpback whale singing over PA)

Oh, yep, all of a sudden we've got three sharks right on top of us.

NARRATOR: The circling great whites begin to rush the

speaker and the cage.

KINA: The sharks are just

all over the cage, and all over the side that the speaker's on.

It's hard not to think that they're reacting to that sound, to be honest.

♪ ♪

(humpback whale singing over PA)

Wow!

Ingrid, we've just got that, uh,

shark with the two big rake marks on its dorsal fin back again!

Look at that!

♪ ♪

NARRATOR: The sharks are clearly responding to the

humpback whale sounds.

The question is, how will they react to the sound

of New Zealand killer whales?

NARRATOR: Ingrid Visser and Kina Scollay want to see how

great whites react to the sounds of hunting orca.

First, as a test, they play humpback whale song.

The sharks come straight to the sound.

KINA: Whoa!

NARRATOR: Including the shark with the bite marks

on its dorsal fin.

They have to wait a few minutes for the sharks to

settle down after the humpback reaction.

INGRID: Now I'm just gonna play you the sounds from the

orca that eat the salmon, I recorded these guys off

North America.

Standby.

(orca calls over PA)

INGRID (over radio): Can you hear that?

KINA: Loud and clear.

Ingrid, it's really interesting. I-

To be honest, I can't see much difference

in the shark behavior here at all, over.

Not much has changed down here.

INGRID (off-screen): Yeah, well, I guess that doesn't really surprise me

given that these are the fish-eating orca.

NARRATOR: The sharks appear unresponsive to the North American orca calls

but these sounds have never been heard

before in New Zealand.

INGRID: Yeah, Kina, so now I'm gonna play you the New Zealand orca.

These are probably the ones that the great whites have

heard before.

INGRID (off-screen): Stand by.

(orca calls over PA)

(orca calls over PA)

KINA: Just skirted off towards the side of the boat there.

I can't say for sure, but

right now, I can't see

any sharks at all.

NARRATOR: The sharks response was clearly to

move away from the sound.

KINA: That's a huge female!

But she's just not approaching the cage.

Way out across the bottom, I keep seeing these shapes.

Big sharks cruising past.

The sharks are there, but they just don't seem to be interested

in coming anywhere near us.

NARRATOR: Ingrid and Kina observe that the sharks keep

the source of the orca sounds in sight.

But stay well out of the way.

KINA: It is hard to know what's going on, but, um.

Yeah, interesting.

INGRID (off-screen): How was that, mate?

KINA: Yeah, well, another awesome dive down here but interesting.

We've only really had a glimpse, eh?

NARRATOR: The orca sounds changed the behavior of

the white sharks.

From fearlessly coming into the sounds of the humpbacks,

to moving off and keeping their distance when they heard

hunting orca.

But was this a typical animal reaction to danger?

INGRID: You know, when you think about the bite marks

that we saw that could've been the orca,

and you saw the way that the great white sharks, you know,

there was a bit of a reaction there but not full on.

KINA: Obviously, we'd have to do this a lot of times to be able to say for sure.

INGRID: Yeah.

KINA: But maybe actually the sharks aren't so scared of orca.

INGRID: Well, maybe New Zealand sharks are more

exposed to it like even from when they are little sharks,

and so they just become habituated to it.

NARRATOR: When orca killed five white sharks in South Africa in 2017,

many scientists believed it was a

first for the region.

But is it possible that white sharks have been fending off

orca attacks for thousands of years?

And what we see are only the most recent incidents in an

ancient and on-going battle?

INGRID: I guess the big thing for me is, you know,

how far are these orca going?

We've got some evidence that suggests that they are at

least trying to have a nibble on them, but, uh,

you know I'm, I'm curious to know just how far they've taken it.

NARRATOR: So far, there have been no reported serial shark

attacks in New Zealand.

But here on the far side of the world,

the unseen struggle between orca and white shark goes on,

in secret, for now.

Captioned by Cotter Media Group.