Original subtitles

BEN (off-screen): It was like a scene out of Jaws.

There was blood coming down the stairs trickling back into the water.

NARRATOR: When a vacation hot spot is rocked by

a series of shark attacks,

chaos reigns.

JUSTINE (off-screen): When I looked down at the injury,

half of my leg was missing.

NARRATOR: All the victims are attacked in

the same small patch of ocean,

no larger than four football fields.

ADAM (off-screen): We really need to get to the bottom of it and

we need to get to the bottom of it fast.

NARRATOR: Is a rogue serial killer on the loose?

Or is something new drawing sharks and

humans into conflict?

NARRATOR: September 19th 2018.

Justine Barwick is on a yachting vacation with

her husband and friends in

Australia's remote Whitsunday Islands.

JUSTINE (off-screen): It was the sixth year running that we had been.

The water's beautiful, the beaches are lovely,

the hikes are great.

We just love it there.

NARRATOR: The Whitsundays lie at the heart of

the world-famous Great Barrier Reef.

One of Australia's most popular vacation destinations.

Over half a million tourists flock here every year

chartering yachts for the trip of a life time.

(laughter)

But beneath the waves something is about

to shatter the peace.

JUSTINE (off-screen): The conditions on that day had been really good.

But the weather was meant to be rough for

the following two or three days.

So, we made the decision that we would wait that weather out

at Cid Harbour, which is such a good place to do it.

It's so sheltered.

NARRATOR: Justine swam in Cid Harbour on countless occasions.

JUSTINE: Before I dive into the water I do sometimes think

of the sea being home to, you know, creatures that,

that might sting or bite.

But I didn't have those thoughts that day.

NARRATOR: There's good reason to feel safe.

While the Great Barrier Reef is home to bulls,

tigers and hammerhead sharks, the sheltered waters of

the Whitsundays are considered some of the safest in Australia.

ADAM (off-screen): In the last 20 years there's been like one shark bite

at Whitsundays and the Whitsundays is one of the most

visited areas in the whole of the Great Barrier Reef.

So, you, you can imagine per year there's like thousands

upon thousands of people in the water down there.

NARRATOR: At 5:00 pm,

Justine's world is about to change.

JUSTINE: I dived into the water and then as I came back

up that's the moment that the shark bit my leg.

Years later I still struggle to describe the force with

which the shark made impact with me.

I turned and attempted to push the shark away from me and

then I knew I had to get out of the water.

NARRATOR: Justine has a life-threatening bite to

her upper thigh, the size of a dinner plate.

Her femoral artery is severed, she's bleeding out.

JUSTINE (off-screen): Swimming back to the boat,

my right leg wasn't working as I would expect it to.

But it wasn't until I tried to get up the swing ladder that

I, I became really confused as to why

my right leg wouldn't work.

NARRATOR: In shock, Justine is dragged aboard by her husband.

(whimpering)

JUSTINE (off-screen): When I looked down at the injury,

half of my leg was missing.

(whimpering)

And I, I knew I was in really big trouble at that point.

(whimpering)

I, I said those words, "I think I might die."

I thought my kids would be sad but they're,

they're grown and they would be okay and that my husband,

he could go on and, and still be happy, maybe.

NARRATOR: Justine's friends desperately try to stem

the bleeding using towels to compress the wound.

Their quick-thinking help save her life.

MAN: Any vessels in the vicinity or able to get to Cid Harbour?

Patient has a shark attack bite

NARRATOR: Within minutes a doctor vacationing on a

nearby yacht responds.

JOHN: And I thought, well if anybody could help

I probably could help.

Uh, I'm an emergency doctor.

The cockpit floor was slick with blood and Justine was so

unwell but she unbelievably was surviving, um,

really because of the, uh, the first aid.

NARRATOR: On the mainland, medics mobilize.

BEN (off-screen): This is a first shark attack for the entire crew.

Adrenalin's running, tensions are high.

There's a lot of discussion and planning about what are

we going to do when we get there?

What are we going to be faced with?

PILOT: This is rescue 412 helicopter

Do yo have a visual on the helicopter?

And do you have any audio?

Can you hear the helicopter approach?

NARRATOR: Help arrives at Cid Harbour in ten minutes.

But with no easy way to reach Justine,

and her condition deteriorating,

Ben makes the decision to swim for it.

JUSTINE: I think Ben's decision to jump into

the water where I'd just been bitten by a shark very,

very, um, recently, it's, it's nothing short of amazing.

BEN: I get asked a lot like,

"Oh, were you thinking about the sharks?

Worried about the sharks?"

And then not really, because I'm too busy thinking about

all the stuff I've got to do.

NARRATOR: Two hours after the bite,

Justine is finally winched into the helicopter.

JOHN: I felt a great sense of, uh, despondency because I thought

Justine wouldn't be alive at the top of the wire.

NARRATOR: On the rescue helicopter,

the medical team realizes just how serious

Justine's wound is.

BEN: There's an arterial bleed, um,

quite significant, a lot of blood loss.

NARRATOR: By the time they reach the mainland,

Justine is unconscious and close to death.

BEN: The thought did run through our minds where

we're like there's every chance that she won't come out of this.

NARRATOR: But after a long night of intensive surgery,

her severed artery is repaired and

surgeons work to save her leg.

But what had actually attacked Justine?

JUSTINE: I didn't see it before the incident or

after the incident.

I've got a memory of my hands on the shark.

I can remember what it felt like,

the force back through my arms.

Um, it was incredibly solid.

NARRATOR: The Cid Harbour mystery begins.

Australian shark expert, Richard Fitzpatrick hears

the news within hours of the attack.

RICHARD: I was very curious, you know,

shark attacks on the Great Barrier Reef are

extremely rare events.

And we were starting to get phone calls in from

concerned tourism operators and

everyone just wanted to know what was it?

Will it happen again?

NARRATOR: Little does he know, these questions would dominate

the next two years of his life.

At Florida's world-famous international shark attack file,

Dr. Gavin Naylor keeps a meticulous record of

every single shark attack recorded around the world.

GAVIN: This is an x-ray image of Justine Barwick's injury.

And you can see it's a fairly clean bite and

a semi-circular bite.

There's no doubt in my mind that, uh, this is from a shark.

This is a very, very explosively powerful bite.

White sharks are always the thing that we jump to

when there's been a shark attack in Australia.

Over the past 20 years,

there have been 91 bites attributed to white sharks.

But in this instance,

we don't think there's white shark involvement.

White sharks in general prefer cooler waters and the bites in

the Whitsundays are outside of this range.

So, it's more likely to be a tropical shark.

NARRATOR: But before anyone can investigate further,

just hours later, news of a second attack

rocks the Whitsundays.

NARRATOR: 2018 and a shark attack victim,

Justine Barwick, lies unconscious in the hospital.

Australia is rocked by more bad news.

REPORTER (over TV): There's been another savage shark attack

in the Whitsundays.

The two maulings, less than 24 hours apart,

at the same beach.

TIM (over TV): This is now a fight for life for the

12-year-old girl who remains in a critical condition

inside Mackay Hospital where

she's currently undergoing emergency surgery.

BEN (off-screen): When the second call came in I was actually just

leaving work to head home for the night.

And I got to the end of the runway and my phone rung again

and it was the helicopter phone saying,

"Oh, you need to get back there's been

another shark attack at Cid Harbour."

It's, it's a bit unbelievable at first and,

you, you kind of think it was like,

"Oh, has someone made a mistake because it's, uh, it's exactly the same thing."

NARRATOR: Racing to the scene,

the paramedic team arrives within

40 minutes of the attack.

BEN: So, we met the patient on shore.

We were worried about it because she is a young girl.

Just a lot of blood missing, a major impact wound to the leg.

NARRATOR: Hannah Papps is struck just before 2:00 pm.

Just like the first victim,

she jumps into the water for a swim.

And just like Justine, within seconds she's attacked.

(screaming)

BEN: We could tell that it was definitely

a smaller bite wound than Justine.

But being such a young girl with such a major bite there

was every chance that she was not going to make it.

NARRATOR: Just two hours after the alarm was raised,

Hannah arrives at Mackay Hospital where

surgeons battle to save her life.

They stop the blood loss,

but sadly Hannah's left leg has to be amputated.

BEN: It's always hard to hear that a child has lost a limb.

It's a lot sadder to hear when your patient doesn't make it.

So we were still, still pretty stoked that she, um, got out of there.

NARRATOR: What had attacked the two Cid Harbour swimmers?

Like Justine, Hannah is bitten in the afternoon on

the inside of her leg,

shortly after entering the water.

And most worrying of all, it happens within yards

of the first attack site.

Coincide?

Or is a serial attacker on the loose?

The scientific community is baffled.

RICHARD: To have lightning strike twice in one spot within 24 hours,

it's the first time it's happened on

the Great Barrier Reef.

ADAM: These people are just hitting the water and

getting bitten, you know, something odd is going on.

GAVIN: Individual shark attacks are incredibly rare events.

Clusters of shark attacks are even rarer.

They're like hen's teeth.

In the 6,000 plus records of shark bite incidents we have

in the shark attack files, there's no more than a handful

of them that are associated with these cluster attacks.

NARRATOR: The most famous cluster incident was the

New Jersey attacks of 1916 that likely

inspired the movie Jaws.

Over 12 days, four people were killed and one injured.

As shark struck swimmers at seaside resorts along

the Jersey shore.

More recently, in 2010, oceanic white tipped sharks

were blamed for a similar spate of attacks on tourists

in Egypt's famous Sharm el-Sheik resort.

GAVIN: We don't know what triggers cluster attacks at all.

And it's very likely that the triggers for one species in

one part of the world are quite different than

the triggers in another part of the world.

NARRATOR: Back in Australia, with lives on the line and a

multibillion tourism industry under threat,

the state government takes swift action.

REPORTER (over TV): The tropical holiday coast has

been rocked by the attacks.

Baited drum lines sit today in a bid to catch the shark.

NARRATOR: Police patrols are initiated,

warning signs erected and baited hooks set to cross Cid Harbour.

Within 48 hours, four sharks are caught and shot.

All tigers.

The largest over three meters in size.

Has the suspect or suspects been caught?

Shark experts have their doubts.

GAVIN (off-screen): There's only been six confirmed,

unprovoked bites by tiger sharks in Australian waters in

the past 20 years and only two of those have been fatal.

So, in a country where there are so many bites,

the fraction that are due to tiger sharks is

actually quite small.

They'll feed on birds, they feed on turtles,

they feed on marine mammals.

So, they're not really specialist feeders.

And so, this plays into the idea that tiger sharks could

be opportunistically biting people.

Certainly, the first bite was of a large animal.

But the intent and the severity of the bite and

the speed that it must have occurred is not typically

characteristic of a tiger shark.

NARRATOR: One week later, with no further attacks and

the busy holiday season coming to an end,

state officials decide to remove the drum lines and

curtail the police patrols at Cid Harbour.

Just a month later medical researcher Daniel Christidis

anchors his rental yacht in Cid Harbour.

On a five-day vacation with a group of fellow medics,

they choose Cid Harbour as their first night's anchorage.

At 5:30 pm, Daniel and a colleague decide to take

the paddle board out.

Taking turns to swim and paddle across the bay.

Minutes later, Daniel jumps in.

Within seconds Cid Harbour has another victim.

(splashing)

♪ ♪

BEN: When the third shark attack came in,

once again it was sort of coming on dusk and

then the phone rings, the siren goes through the hanger,

it's another shark attack.

Cid Harbour all over again, the same thing.

We were just sitting there going this is unbelievable.

We received another phone call on the way out saying that

the CPR was in progress.

Obviously the patient's quite unwell.

It's quite a confronting scene to rock up to.

There's a lot going on.

It's dark.

There was blood coming down the stairs,

trickling back into the water.

There was more than one major bite wound.

So, the body's going into shock,

it's starting to shut down.

The heart's not beating properly,

there's not enough blood going around.

So there's a, there's a lot needed to be done to stabilize

the patient before we could actually move him.

NARRATOR: Shortly after arriving at the hospital,

Daniel is pronounced dead.

BEN: I mean it's probably right up there as probably

one of the worst days I've had.

I don't know, you know that the work that you did do is

all that you can really do and you provide them with

the best that you can do, um.

Sometimes it's not enough.

Sometimes it is.

GAVIN (off-screen): The third victim had extensive wounds on

his legs and also on his wrists.

And it's clear from the pattern of bite marks that

this third victim was attacked by a large shark.

NARRATOR: Has a lone rogue shark struck again?

With lives on the line, the government calls in

the help of shark experts.

RICHARD: So that's the channel.

NARRATOR: Richard Fitzpatrick and Adam Barnett have been

studying Australia's sharks for over 20 years.

ADAM: So, that's the area across there were the,

the shark bites occurred.

NARRATOR: If anyone can discover what's attacking

people in Cid Harbour and why, it's them.

ADAM: Something strange is going on here in this bay.

I mean it's unusual to get three bites in such a short time,

but also in such a small area.

We really need to get to the bottom of it and

we need to get to the bottom of it fast.

RICHARD: This area is essentially a black hole of

information for us on, on shark biology.

A lot of work's been done to the north and south.

But here we know very little.

NARRATOR: They need to find out what sharks live here and

why these previously safe waters have transformed

into a killing zone.

ADAM: We're throwing everything we can,

every bit of technology available to us.

We're going to throw it at this and

see what we can find out.

RICHARD: We know nothing at the moment.

RICHARD (over radio): Adam, Adam do you copy?

ADAM: Go ahead skipper.

NARRATOR: Adam and Richard review the details of each attack.

RICHARD: So, there are some distinct patterns that have

happened with the bites in Cid Harbour.

First is the time of day.

They were all in the afternoon.

The other really interesting one is that they've all

occurred in an area about the size of a football field.

That is really unusual.

The other thing is that the bites have happened almost

instantaneously after the victims have jumped in

the water and splashed.

NARRATOR: Like Gavin, Richard thinks the evidence points

away from tiger sharks.

RICHARD (off-screen): Whatever has done it has reacted straight away.

That's not tiger behavior.

They're a bit cautious in how they approach things.

They tend to be a bit slower in how they react to baits and pray.

So, this leads us to think it's possibly something else.

NARRATOR: But if a tiger isn't responsible,

what did attack the Cid Harbour swimmers?

To find out the team set a series of baited lines and

within hours they hook their first shark.

MAN: Uh, looks like we've got a bit of action on the, uh, set lines.

ADAM: Okay mate, uh,

yeah, we'll just pop over and have a look at it.

MAN (over radio): Yeah, copy that.

NARRATOR: With its distinctive striped back

it can only be one shark.

RICHARD: I can see the white snout.

ADAM: Sort of just hanging,

oh we've got our first tiger of the trip.

RICHARD: Whoa. ADAM: Hello.

RICHARD: Hello. Hello big boy.

ADAM: Whoa, okay.

That's Let it, let it go, let it go, let it go.

NARRATOR: Over three meters long,

she's a mature female.

ADAM: Whoa! Okay, let it go.

Tiger sharks is a species which is copping some of

the blame for the bites.

So, it's going to be really interesting to get some tags

on these guys and see what their behavior is in this general area.

NARRATOR: The team works fast to attach a tail rope and

bring her under control.

Next, they prep a state-of-the-art acoustic tag.

Flipped on her back, the shark enters a calm trance

like state known as tonic inability.

Adam then inserts the tiny tag in

the body cavity under her skin.

Within minutes, the Whitsundays

first tagged shark is released.

RICHARD: Woo.

(beeping)

NARRATOR: The team name her Alara.

She gives off a steady acoustic signal

as she swims away.

The signal will be picked up by a network of listening stations

the team plans to deploy around the Whitsundays.

But first, someone needs to set them up.

(splashing)

Richard draws the short straw.

RICHARD (off-screen): I don't like going in water that I can't see through.

And the things that struck me first when I came here

was just the lack of visibility in the water.

NARRATOR: With a safety diver watching on,

he works fast to set up the first acoustic listening station

outside the northern entrance to Cid Harbour.

(beeping)

The listening stations will eavesdrop on the islands 24-7.

If tiger Alara or any tag shark comes within

30 meters of a station it's date,

time and position will be logged.

It should give the team the first detailed picture of

whether any sharks are hanging around the attack site.

It could lead them straight to the prime suspect.

♪ ♪

NARRATOR: Across the Whitsundays hundreds of baited

cameras are deployed and listening stations fixed as

scientists race to understand why these

previously safe waters have turned deadly.

And as the footage comes in one big clue emerges.

The poor visibility.

ADAM: What we have here is a satellite image of

the actual water clarity of the Whitsundays area.

It's showing the turbid waters versus the clearer waters.

And as you can see, most of the Whitsundays region

itself is quite turbid.

Including Cid Harbour in here.

You don't get the bluer waters until you move off shore.

These turbid waters are probably driven by the

actual sediments coming off the land and

out of these river systems.

Now the interesting thing about these river systems is

that these are pretty key habitats for bull sharks.

NARRATOR: In the last 20 years bull sharks have been responsible

for five attacks in Australian waters.

Armed with an incredible sense of smell and a sixth sense

that allows them to detect vibrations in the water,

they're perfectly adapted for hunting in murky conditions.

But without vision, they can make mistakes.

GAVIN (off-screen): Most shark bites are cases of mistaken identity.

If you live in an environment where you can't see very well

you have to be very, very quick and very decisive.

So, they'll bite quickly and sort of ask questions later.

So, this is consistent with at least

the first bite in Cid Harbour.

This is one bite that's removed a chunk of flesh

in, in one fowl swoop.

If I was a betting person I would lean towards this being

inflicted by a bull shark.

NARRATOR: On the Australian mainland,

Richard and Adam's colleague,

Andrew Chin is following a different line of enquiry.

He's trying to discover why these previously safe waters

might have turned so deadly.

ANDREW: And what we were looking for is the perceptions

of people who had been to the Whitsundays over the years

understand what sort of things had they seen?

What did they think was happening in some of

these different anchorages like Cid Harbour?

Was there anything that people were doing that could explain

what might have just happened.

When we have a look at the data,

it's obvious that Cid Harbour is a very busy place.

There's a lot of people anchoring in there,

there's a lot of activities going in there,

people are paddle boarding, people are swimming.

So you've got a lot of water board activity.

You also have people discarding rubbish,

throwing food scraps over the side,

some people are even fishing or

baiting in these anchorages.

Those two activities don't go hand in hand.

Sharks are smart, they will learn.

They're not going to waste energy swimming around the

whole ocean looking for food when you can get it delivered

to you off the side of a boat.

NARRATOR: Throwing food waste overboard is illegal in

Whitsunday waters, but the team unearths evidence that

the practice continues.

Could this be triggering the attacks?

ADAM (off-screen): It definitely was a turning point.

You start putting two and two together of like,

okay these people are jumping off a boat

or falling off a paddleboard and

getting bit straight away and there's reports of lots of

food going in the water.

Lots of boats.

RICHARD: If you imagine being a shark in that situation,

you're cruising around,

there's food scraps thrown in the water.

Smell can drift for long, long distances as well.

So, they could be following that up current to its source

thinking what's happening here.

As more scraps go in the water then they can feel the

commotion of little bait fish zipping around and

going for a feed and all that kind of stuff.

So, there's a lot of stimulus in the water.

When they switch into feeding mode they're like a bit more

on edge and they're, you know,

"Oh, okay where is this,

where is this, where is this?

I'm trying to find the source, trying to find the source."

The visibility is bad.

You can't really see around.

There's a huge shadow above me but something's under it and

then splash boom, oh cool.

I'm going to go for it.

And unfortunately if it's a person that's jumped in at that stage,

they will come through at high speed and bite.

NARRATOR: The possibility that human activity could trigger

the attacks is new and alarming.

And has implications for every bay around the world

where boats gather in large numbers.

Particularly locations in Southern Florida.

ANDREW: The other thing that a boat does is it provides you

with a hiding spot, right?

So you have this big thing of shade that

hangs over you with structure.

It's kind of like a movable ambush point for a shark.

And it's interesting that many of the shark bite accounts

that we have, not, not just in Cid Harbour,

but everywhere, people have been bitten when they have

jumped into the water with a splash and

then they've been struck.

NARRATOR: The likely cause of the cluster attacks now uncovered,

the team races to identify the potential culprit.

RICHARD: What have we got here?

Whoa!

NARRATOR: Over the course of 12 months,

the team make five trips to the Whitsundays as

they attempt to discover what sharks might have been

responsible for the Cid Harbour attacks.

They only catch and tag 43 sharks, including 18 tigers,

three hammerheads and seven bulls.

A low number by Great Barrier Reef standards.

RICHARD: Oh yeah, that's a decent size.

Hello.

One of the biggest surprises were we weren't catching a lot.

We were putting in a lot of fishing effort.

So, it's what we weren't getting that was probably

the biggest surprise to us.

NARRATOR: Over 500 hours of baited camera footage

is also reviewed.

ADAM: Oh! Hello. RICHARD: Oh hello.

Nice little female tiger shark.

NARRATOR: And once again, shark numbers are low.

RICHARD: But she's only about,

I don't know, 1.8, two meters max.

NARRATOR: But by far the most common sharks are spot tails

and black tips belonging to a group known

as the small whalers.

RICHARD: It's a very large group of, um, sharks that have

been implicated in bites around the world.

Mostly in association with spear fishing and fishing.

Sometimes they can come up to boats and

particularly fishing boats and

things like that where there's scent coming off them.

NARRATOR: With their reputation for hanging around boats,

could these smaller sharks be responsible for

any of the attacks?

GAVIN (off-screen): Given the size of Justine's wounds,

I think that we can discount a lot of the smaller whaler sharks like

black tip sharks because the diameter of the bite marks

on the first victim were just simply too large.

That said, the much smaller bite on the second victim

could indeed have been, uh, a bite from one of

these smaller whalers.

Especially given that they're so abundant in Cid Harbour.

NARRATOR: Rather than one rogue shark,

could the attacks have been by a variety of

different shark species.

Before they could find out,

news of yet another attack comes in.

REPORTER (over TV): A tragic end to an

idyllic morning of snorkeling.

28-year-old Alistair Radan had his right foot severed.

His 22-year-old friend Danny Maggs suffered

deep cuts to his leg.

RICHARD (off-screen): I was driving to a meeting in town when,

you know, I got a text through that there had

been another incident.

We heard of where the location was and

it was just around the corner from Cid Harbour.

And so instantly going through our mind was like,

was it one of our animals?

NARRATOR: The two victims are snorkeling when

they are attacked.

(muffled yelling)

Play fighting in the water,

the noise draws in the attention of a shark.

(muffled yelling)

(splashing)

(yelling)

WOMAN (over TV): One of the male patients was attacked first, um,

and the shark is believed to have returned and come back

and attack the second patient.

RICHARD (off-screen): A friend of ours was working down there,

in the Whitsundays, had been through the channel

that morning and had commented that there was a lot

of bait fish in the water.

Sea birds were hitting.

So we knew it was biologically very active.

(splashing)

(laughing)

The two guys, they were skylarking in the water,

pushing each other down and making a lot of commotion.

A lot of splashing right next to where there's

a big bait fish aggregations.

We also got reports that there was another boat

recreationally fishing right next to the boat

when it was snorkeling.

Layered on top of that low visibility and it's like,

you know, a bit of a recipe for disaster.

GAVIN: Eye witness accounts of the injuries sustained by the

two snorkelers suggests that the species involved was much smaller

than the individual that was involved in the first bite.

Probably more consistent with a whaler shark.

NARRATOR: Incredibly, the latest attack takes place

just yards from one of the listening stations.

If one or more of the tagged sharks is responsible,

there ID, time and location will have been logged on

the underwater recorder.

The team could finally have proof of the attackers identities.

NARRATOR: 18 months after a series of shark bites shakes

the remote islands of the Whitsundays,

the acoustic listening stations are pulled from the water.

And the team paw over the data.

RICHARD: Comes in from the outside.

So, here's the initial cluster in Cid Harbour.

And then 13 months later we've had this incident up

here in, uh, Hook Passage.

We actually have a receiver just around the corner.

So, we've retrieved that to see what was around in

the area at the time of the incident.

ADAM: There was two detections from the same animal, uh.

12:30 at night and 1:43 in the morning.

So, way after the incident.

Shark number 12808, which is a bull shark.

Prior to the bite there was a, a different animal,

about 11:00 in the morning.

So, it's shark number 128,

uh, pretty sure that's a bull shark as well.

Yeah, look, it's pretty clear from this data that our,

one of our tagged sharks was not there at the time of the bite.

(screaming)

NARRATOR: The identity of the most recent attacker remains unknown.

But as 18 months’ worth of data is analyzed,

some surprising patterns emerge,

shedding new light on this tragic cluster of incidents.

By far the most common large shark showing up

in Cid Harbour is the tiger.

ADAM: It's recorded 18 individuals.

NARRATOR: And their movement patterns make them

a prime suspect once again.

ADAM: This is, um, a shark we called Ingo.

It's a juvenile male, one of the first ones we tagged.

Um, you can see it starts of in Cid Harbour,

moves widely over the Whitsundays,

but you see it keeps on looping back through

Cid Harbour out again, back again,

coming back, coming back.

RICHARD: So what we see of Ingo is actually not unusual.

When you zoom out wider and look at, uh, a few of the other tigers,

we're seeing that they're doing the same thing

of going out on these big swims out to these

other potential feeding areas.

But you see them always looping back through

the Cid Harbour area.

So the question is, why are these tiger sharks

focused on the Cid Harbour area?

ADAM: We've seen a lot of shark prey in the bay,

you know, there's stingrays, there's turtles,

there's lots of other fish that smaller sharks that

the bigger sharks eat.

So, there's definitely food in the bay.

But we're not seeing anything that you might think,

"Oh, that's going to attract a lot of sharks in, you know."

That's the thing, there's nothing unusual about the bay.

The most unusual thing about the bay probably is that

there's 100 boats in the peak season mooring there and

throwing stuff in the water.

NARRATOR: Next, the team analyzes the data on bull sharks.

With just seven caught, they're not as common

in Cid Harbour as expected.

RICHARD (off-screen): One of the first bull sharks we tagged was

as big 3.2 meter male, that we called Bevin.

So, he was tagged in July and he has swum over 1,500 miles

to the very tip of Queensland and

back in a three-month period.

I mean that's a substantial swim.

ADAM (off-screen): We tagged seven, seven bull sharks and

most of them showed really large-scale movements

up and down the coast.

They returned to Cid Harbour but

for very short periods, passing through.

You probably sort of want to dismiss them based on that.

But we had one shark, it was the last shark we tagged.

Uh, that animal actually didn't make any large-scale movements.

It hung around the Whitsundays area in general.

It spent about 50% of its time moving through or

staying in Cid Harbour.

Out of the biggest sharks we've tagged,

this is the only one that's really shown

some sort of short-term residency.

So, we'd be silly to actually rule him out as

possibly being responsible for at least one of the bites.

NARRATOR: Along with tigers and bulls,

only one other group of sharks could be involved in the attacks.

ADAM: The only other shark that actually spent quite a

bit of time in Cid Harbour itself was a, was a...

one of the spot-tails we tagged.

And they spend about 50% of its time in Cid Harbour,

but it's not getting picked up on any of these other locations

we had receivers around the Whitsundays.

So, it looks like it spent a lot of time in the bay.

NARRATOR: With such a small number of sharks in the study,

exactly who was responsible for the attacks may never be known.

But with tigers, bulls and small whalers all spending

time at the attack site, none can be ruled out.

GAVIN (off-screen): Every time we see a cluster of bites,

in the same area of the world over a short period of time,

everybody jumps to conclusions and

it's one individual that's responsible.

Every time we drill down and looked into it,

we can't find any scientific evidence to support that.

Instead, we find increasing evidence that it's likely to

be different individuals,

sometimes even different species.

I think something similar is going on in Cid Harbour.

The medical examination suggested that the first bite

was by a very large animal and

the second bite was much, much smaller.

So, clearly we're not looking at one rogue shark.

Something in Cid Harbour is causing different sharks to

act in this peculiar way.

ADAM (off-screen): You know it's not the be all and end all what did it.

It's like well, why?

So, I think that's the more interesting question.

Is it the perfect storm?

Because Cid Harbour's got a lot of natural pray,

so it makes sense that sharks are moved through there.

It's got very bad visibility.

There's people in there like dumping scraps,

attracting sharks for fun, you know, there's fishing, uh,

cleaning their catch so they can eat it.

Then you've got other people that are swimming, snorkeling,

paddle boarding, jumping off boats and splashing.

ANDREW (off-screen): Sharks are smart.

They will learn.

So, when something falls, splash into the water,

they're going to strike at it.

ADAM: I think the interesting thing is that it's not just Cid Harbour,

this is happening in other places.

There's other bays up and down the Great Barrier Reef,

and probably around the world,

that humans are doing very similar behavior and

some of these places are probably just

next in line to have some sort of shark incident if

they keep on going the way they're going.

RICHARD: It's important that we learn from this experience,

and we are.

You know, there's a lot of changes happening.

ANDREW: If you're on a boat,

don't throw your stuff overboard,

don't throw your waste overboard,

don't fish where people are swimming.

They're just not compatible activities.

It's not worth the risk.

RICHARD: You know, what we're talking about is common sense.

So it's just having people think and become shark smart.

NARRATOR: Scientific research into Cid Harbour's

shark population is ongoing and the survivors continue their recovery.

Justine Barwick still needs regular physiotherapy and

walks with a cane.

JUSTINE: My leg has been reconstructed by using a

muscle from my tummy and also, um, skin from my tummy as well.

Rehabilitation has been extensive and, and it even

two years down the track it continues to

be a, a really big commitment.

I can't feel my leg but the physio's taught me to,

to walk on this leg that I can't feel.

I just feel incredibly lucky to be back at work,

to be back with my family and really enjoying life.

Captioned by Cotter Media Group.