Original subtitles

[narrator] Australia is the world's largest island.

Geographic separation over thousands of years

resulted in 90% of the species found in Australia

being endemic to this vast land.

And for the locals, living here means living

amongst some of the world's most dangerous animals.

Some of these animals can kill instantly,

others leave lasting injuries

and some can just inflict a nasty bite.

In all, 72 animals can cause us damage,

but which one tops the list of most dangerous?

Taking first spot in the arena

is a creature who is silent, prehistoric and deadly.

Once a favorite swimming spot.

Now a place full of horrific memories.

When it hit me, I don't know, it was just sharp pricks

and it was hard.

Something had hit me real bad.

Initially Mark thought he'd been hit

by the force of a boat propeller.

He was only 25m from shore,

splashing around with family and friends

in a spot they'd been coming to for more than 20 years.

But five minutes into his swim,

in the middle of a backward roll,

the wind was knocked out of him,

he was struggling to breathe.

Halfway through the roll

and this thing hit me from under water.

Lake Argyle is about a half-hour drive

from Kununurra in the north of Western Australia

and is a must-see on the tourist list.

But visitors be warned -

freshwater crocodiles also frequent this destination.

Known as the Johnston's crocodile,

this reptile is widespread

across the northern regions of Australia.

They prefer to live in the inland river systems

and are thus known as the 'freshie',

although they can tolerate quite high levels of salinity.

They don't need a great deal of food to survive.

Roughly one fish a week is enough.

But if food is on offer, they'll take it.

They're experts at building up their condition,

storing around 70% of their food,

which allows them to go through the dry season

without actually eating anything.

They're an ambush predator, so beware,

they'll be lurking -

not wanting to attack, but ready if confronted.

Yeah, I didn't know which way was up, which way was down.

Up or down, confused,

the crocodile had spun Mark around.

He needed to escape the depths of the water.

It was dark and there were no clues

of how to get to the surface.

He was on his own.

The pressure was increasing in his ears.

He needed to get air. Time was running out.

He was wounded, bleeding,

the realization sinking in as to what had happened.

I just remember the things

going into my arm and the side of my chest

and then the swish of the water coming around me,

which I later learnt was the tail

as it went in the other direction.

For Mark, he was living a nightmare,

trying to get away from any further danger.

For the freshwater crocodile, it wasn't much different.

The only reason it's biting you is to defend itself.

It's not a food response,

it's not an act of aggression towards you.

Nuala is part of a team of rangers

at Billabong Sanctuary in Queensland

that present a freshwater crocodile show

on a daily basis for tourists.

Safety is paramount to the show.

Knowing crocodile behavior is the key to their safety.

Whoa!

That crocodile's not gonna try take you away.

It's gonna bite you and then hope

that you're gonna run in the opposite direction.

For Mark, swimming in the opposite direction

was his plan.

But he was losing blood, he was disoriented,

he only had use of one arm.

Saving himself was his only thought,

but panic had set in.

Mark was trying to swim as well as he could,

struggling against his injuries,

struggling to find the right direction.

Well, I started swimming towards the middle of the lake

where you can't even see land.

His confusion led him back

to the spot where he'd been attacked.

Survival.

I needed to get back to shore.

And I'm ready for this thing to come a second time.

I'm ready for it the next time.

He had to find the courage

to swim over the top of where he'd last seen the crocodile.

I suppose like they do in the war when you get shot,

you run towards the enemy without thinking.

By now, time was critical for Mark.

He was still a long way from the shore

and miles from the closest town.

And of course, he was still losing blood.

I had to go back and by then I didn't have any air left,

I was gasping for air

and I was trying to warn the other people

that I'd been bitten

'cause I'd sort of worked out that time

that my arm... blood was coming out of it

and it wasn't functioning.

[Nuala] The bite itself will be many lacerations,

in the sense that the teeth are very sharp

and they're likely to pull at you.

And so it would split your skin.

You probably wouldn't be able to stitch that wound.

Mark's friends were quick to get him to safety,

applying pressure bandages

in an attempt to stop the bleeding.

Keeping Mark still

during the 25-minute drive to the hospital

was paramount to his survival.

His wounds were numerous, horrific

and almost cost him his life.

[Nuala] They can hold their breath for several hours.

What they do is they actually slow their heart rate down.

OK? So they reduce the amount of oxygen

that they need to flow around their body,

which enables them to stay submerged for longer periods.

OK, so they swim using their tails -

that is the engine of a crocodile.

When they're under the water, they will actually walk

along the bottom of the river to save energy.

But it's got numerous sharp teeth there.

You can just see his nostril on the top.

Just here are his ears.

And these are his eyes.

Profiling the characteristics of the crocodile,

it's hard to believe it's not considered to be aggressive.

I had my arms above my head, up here,

and the crocodile come down there

and down there and there.

Feet were over here.

Mark was covered in cut marks -

marks from the teeth of the crocodile,

as well as cuts caused by the feet

scratching across his body.

I tell you, there was a lot of blood coming out there.

And the pressure bandages on there and there,

I think, really stopped me from losing the blood.

There's no doubt Mark's injuries were gruesome.

It was very much a case of being in the wrong spot

at the wrong time.

The action of his friends saved his life,

but there was one confronting fact yet to be revealed.

Well, the doctor was, um... she was quite graphic,

she liked me to see what was going on,

so she showed me the skin she was cutting off

'cause it wasn't gonna stitch up properly

and then she put her finger in there,

which went right up past the second knuckle, you know,

and she's flicking out this artery and she's saying:

"See that artery, Mark, if that was broken,

you wouldn't be here to tell the story.

You would've lost all your blood."

And she's just holding it.

92 stitches, a long course of antibiotics

and many scars have led to a new-found respect

for this incredible animal.

[Nuala] They can move very quickly

and they can also jump reasonable heights,

so you have to have your wits about you.

In the wild,

freshwater crocodiles will actually shy away from people.

So if I was out with my fishing rod

heading down to the water's edge, making noise,

talking to you guys,

these guys in the wild would shoot off.

They would realize that something big is coming

and they don't want to interact with it.

The fact that these guys live in captivity,

they understand that us rangers

coming into the enclosure means that food is on, OK?

Or potentially. So that is why they approach us.

Crocodiles have great camouflage ability.

They range in color from browns

through to greens and yellows,

enabling them to be well hidden

in river systems and billabongs.

This gives them that element of surprise over their prey

and when they feel threatened.

[Nuala] I've not had any close calls yet.

We do work in a controlled situation

so we try and minimize the risk

and if we feel there is gonna be an issue,

we won't even go in.

Working with crocodiles and freshwater crocodiles

brings an excitement that cannot be compared

with any other job, OK?

Your heart races, you have to think quickly.

It's an exciting job and I love it.

Animals are competitive by nature.

They need to be to survive.

So in keeping with the action, we're gonna rank them

according to just how dangerous they can be.

We'll scrutinize each one,

highlighting how they can affect your life,

quite literally,

allowing you to decide if you're game enough

to get as close as some of our experts.

The Johnston's crocodile is more likely to run away

than harm you.

However, it's taken its toll on many

and will therefore rank high on our list.

It's our first animal on the show,

so right now it sits at number one.

The question is, will our next featured beast

slither its way higher up the ladder?

A caravan camping holiday

on the magnificent southern coast of Western Australia

turned from a relaxing break to drama

in just four short hours.

We'd started a fire

but we weren't particularly successful

because the wood was quite wet.

Fortunately, a friend was bringing dry firewood

from the farm.

Phil went to get the dry wood from the back of the truck.

It was dark. He put his hand into the stacked wood.

I felt a sharp pain on my left index finger.

Only recently bitten by his son's pet snake,

Phil knew it was probably a snakebite.

He knew what the feeling was like,

but he had no idea what snake had attacked.

Generally, a snake will give you warning

and it'll try and run away.

However, if the snake is cornered,

it's naturally going to defend itself.

Gary Davies has worked with snakes all his life,

removing and relocating

countless numbers of venomous snakes

as well as educating children and adults

about safety around snakes.

Brown snake venom is one of the most potent,

so it doesn't rely on lots of volume,

it's just very toxic.

In this part of Australia, the dugite reigns

and is one of the many brown snakes

that live all over this vast country.

Dugites vary in color from light straw to dark chocolate,

but what is typical

is that they have irregular black scales

that look like freckles.

Average adult size for a dugite would be 1.2m-1.5m.

But then you will get the occasional thumpers

that get up around 2m,

and that's a big snake for a dugite.

They're an elapid snake,

which means they have fixed, hollow fangs

at the front of the mouth

through which the venom is injected.

The pain of the snakebite

was like being injected with a hypodermic needle.

Phil's friends wrapped his arm

in makeshift bandages ripped from a pillowcase.

A call was made to the local nursing post,

but they were advised not to wait for an ambulance -

just go straight to the nearest hospital,

40 minutes away.

Arriving at the hospital,

I was immediately laid down upon a gurney

and told not to move.

The makeshift bandages were replaced

with more compression bandages,

starting at the lower limb and moving tightly up Phil's arm

towards his heart.

An intravenous drip was then hooked up to the same arm.

Venom itself doesn't travel through the veins.

It's actually... it's distributed through the body

through the lymphatic system

which is only just under the skin.

So if we compress the lymphatic system,

we stop the flow of venom

but we still allow blood flow to the limb.

And that way, you don't have to take the bandage off,

you can leave it on for 24 hours.

Longer, if you have to.

One of the biggest misconceptions

about snake envenomation is that people think

you have to identify the snake that gets you.

But you don't have to catch or kill the snake to survive.

Your biggest concern is to get to hospital in time.

Generally, a doctor doesn't know

how to identify snakes himself.

He's gonna ask you what the hell you brought that in for.

You carry all the evidence they need in your body.

To determine the type of snake,

the medical team will carry out blood tests, urine tests

and take swabs around the bite site.

The information will then be processed

in a venom detection kit.

Because I wasn't feeling unwell,

I actually asked the doctor if it would be OK

if I went back to my caravan.

Unfortunately the news for Phil wasn't good.

He may have been feeling well -

often there is no pain from a snakebite -

but the risk was high

and the doctors were taking no chances.

Phil was about to fly out

on the Royal Flying Doctor Service

to a larger regional hospital with both a doctor and a nurse

monitoring his blood pressure and heart rate all the way.

In the emergency department,

blood tests were taken every four hours.

Venom had been detected in his blood

as well as a slight amount of muscle wastage.

My anxiety levels did rise quite sharply

because I realized that I was possibly

in a very dangerous situation.

Snakes are dangerous from the beginning.

There is no parental care, so as soon as the eggs hatch,

the babies are out looking after themselves.

They have to feed, so they're born ready with venom -

much less in volume than an adult snake but still toxic.

[Gary] Dugites aren't fussy.

As long as there's a food source

and good places to hide, they don't care.

They go right through banksia scrub,

all the way through the coastal dunes,

around swampy areas

and right in the middle of suburbs, amongst humans.

They're really not fussy.

Dugites are one of the few species

that have increased in numbers around human habitation.

With settlement comes many places to hide.

Plus their favorite food is the introduced house mouse,

so wherever there are humans, there are usually mice,

thus an environment where dugites thrive.

[Gary] You're never gonna have a problem

with a snake that's just lurking in the backyard.

And, quite frankly, there's probably

lots of snakes lurking in your backyards

that you don't know about already

and as long as you leave them alone,

they'll leave you alone.

For Phil, the venom load was light

and the compression bandages prevented any danger

to his health.

However, there was still care to be taken

when the bandages were finally released.

Six medical staff were on board, ready for an emergency.

Apparently, that's a very dangerous time

because if there's any venom

that has been captured by the compression bandages

and hasn't been dealt with by your body,

it can rush through to your heart

and that's when it can cause some damage.

People have died in Australia from dugite bites.

But through education,

the scientific development of antivenin

and good hospital systems, it's no longer to be feared.

There's no reason to die in this country of snakebite

as long as you do the right thing,

put a bandage on and go to hospital.

The dugite can be deadly

and if you don't get treatment quick, it could end badly.

And even though in Australia

fatal snakebites are few and far between,

its bite still outranks the ferocity

of the Johnston's crocodile.

The freshie moves to number two and the dugite reigns.

But our next animal could see them both slide.

This is a story of history repeating itself.

An event long forgotten on a popular beach

a couple of hours north of Sydney.

80 years later, another tragic day.

I've surfed at Redhead for 35 years

and never seen a shark

and this day was like no other day.

The decision to go for a surf or not,

despite a few mates saying the conditions weren't great,

changed Glen's life forever.

I paddled out and I was getting good waves.

After everyone had said there was no good waves,

I managed to find a spot by myself.

At first, a spot by himself seemed ideal.

But being further out and alone

may have been Glen's downfall.

He was thinking about coming in

when the decision was rapidly made for him

when he realized he wasn't on his own.

I was facing east, and from the south

was just this almighty hit,

like a rubbery boat that felt like sandpaper

and just a massive weight behind it.

The massive weight was about 350 kilos of bull shark,

roughly about 10ft long, aggressive

and keen to make his mark.

They hit you with an impact to disable you

and then they finish you off.

Bull sharks are the master of low-visibility water

and they're specialists at working those inshore waters

where it can be murky, hard to see, camouflaged.

The inshore waters cover a range of environments

from estuaries and rivers to coastal waters,

highlighting the bull shark's ability

to live in both fresh and salt water.

They have triangular, serrated teeth

on the upper jaw

and generally feed on fish and other smaller sharks.

They are known for a bite-shake-and-release attack,

aiming to grab their prey and kill it straightaway.

There's probably more attacks by bull sharks on people

than any other species.

Richard Fitzpatrick is a marine biologist

who has dedicated much of his time

to researching sharks.

They're very attuned to, you know, vibrations in the water,

sound in the water and odor in the water

and using their electrical sense to feed.

It's basically a shark that has to work

in a zero-visibility environment 24/7,

so they're a pretty amazing animal.

For Glen, amazing is an understatement.

This animal is extremely powerful, hostile

and armed for assault.

I knew just instinctively that I was in deep.

You know, I was probably not gonna get out of it.

You know, sort of, really...

yeah, I was in a spot, for sure.

Yeah.

A spot a surfer doesn't want to be in at all.

The worst position a surfer can be in, really.

In a state of shock, Glen was losing awareness of time.

His senses were on overtime.

Confused, not thinking, not knowing what was going on,

his body was in a massive state of alarm.

It knocked me out when it hit me.

I came up drowning

and the shark was laying end to end in front of me

with the dorsal fin 2ft high in front of my face.

Instinct took over, decisions were reactions,

no time to think about his next move,

miraculously, Glen's surfboard -

now with a chunk missing - was still attached to his leg.

He put it between himself and the shark

as a shield of defense.

Get on the surfboard.

This is your only shot. You've only got one chance.

Focusing on survival,

Glen paddled his board toward the beach,

gently at first,

as though trying to sneak away unnoticed.

But he was already leaving a trail of blood.

Reality was kicking in. He had to go for it.

It all happened so fast.

I got on the board and I was moving

because I knew there was no time

to, you know, have a discussion with the fish.

You know, it was hungry, I was its dinner

and it's not the way I wanted to die, you know,

getting eaten alive, you know.

The attack happened about 60m from the beach.

Glen paddled half the distance back to shore still in shock.

He thought he was going to pass out and drown.

I didn't know that my leg was damaged

until I looked over my shoulder, my left shoulder,

to see where the shark was.

And he was about 10ft behind me in my blood trail.

And that's when I knew that I'd been attacked by a shark.

That confirmed my worst fear.

That's what generally happens with bull shark attacks.

You find these really nasty injuries

on the lower parts of the torsos.

If someone's thrashing around next to it,

it'll strike out at it

and have an accidental bite on a person.

The shark didn't waste any time.

He was on Glen's tail, getting closer by the second,

hungry for more, wanting another bite.

Glen was racing to escape, full of fear,

knowing the gap was closing, paddling for life,

when, at that critical moment,

an unexpected act of bravery turned everything around.

There was one person that just stood out

and put his life on the line.

It was another surfer who had stepped into the ring.

While many were scrambling to safety,

Nathan Visscher had sprint-paddled

into the bloodied water

to help swim Glen back to the beach.

It was like my last moments. That's what it was like.

It was like my last moments.

But it all turned around when Nathan arrived.

I could not believe a person

had stepped into this crazy situation to help, you know.

I still can't believe it.

But I remember his right hand

slapping me on the left shoulder here

and I just went around like this,

thinking it was you know who,

and it wasn't you know who with the teeth.

It was Nathan who'd come to help me.

And he said my face was grey from blood loss and shock

and my eyeballs were like golf balls he said,

they were bulging out of my head,

and I guess that was from fear.

The shark was now outnumbered

and, for whatever reason, it seemed that retreat

was the best option - the best option for the shark

and for Glen, the best option of all.

[Glen] But if he didn't intervene,

the shark probably would've got me

because I think the shark felt outweighed

by the presence of these two big things -

myself and Nathan.

When I looked, it was at 10ft,

I was just beside myself with fear,

and Nathan intervened at that time,

which was at the critical moment, really, you know.

Oh...

Nathan Visscher was awarded the Australian Bravery Medal

for his selfless determination to rescue Glen.

But a bravery award wasn't even on his radar

back on that ill-fated day.

He had a job to do

and he needed to stay alert, his wits about him.

Be ready, if need be, to encounter the shark.

Nathan had Glen safely to shore,

lifeguards were waiting, the tourniquet was secured,

the paramedics arrived, oxygen was keeping Glen stable.

I saw this big hole in the leg

and went: "Oh, don't look at that,

that's not good, that'll just make it worse."

Glen knew there was something wrong with his leg.

There was only dull pain for such a traumatic injury

but the blood was pouring out.

There was blood in the water, it was on the beach,

there was a trail marking his tracks.

I think the fear,

you could probably call that a pain in a way,

the fear itself.

The fear of being chased.

The physical side of it is not, you know,

as relevant to me

as that fear when it chased me to the beach.

There was concern amongst the medics on the beach

that Glen had damaged his femoral artery.

But despite the shark ripping and tearing

a large chunk of muscle and flesh from his leg,

the artery was intact.

But three different muscles had been severed

and a major tendon was missing from the pelvis to the knee.

The bite itself was just a huge pressure kind of feeling,

and I realize that that pressure feeling

came from the massive clamping of the jaws

and him grinding away at me, was that pressure.

He spent a fair bit of time

grinding away at me by the looks of it -

there's marks left on the femur bone,

there's teeth marks on the femur.

Teeth marks on the femur

presented a new set of confronting issues.

Whilst the bite of the shark was devastating,

the bacteria in its mouth is an additional killer.

Any slight piercing of the bone

and the infection could be fatal.

Glen had two, possibly three, teeth marks

that needed to be examined.

I was lucky that those teeth marks

didn't penetrate the bone.

If they penetrated the bone, those teeth,

the leg would've been taken straight off.

Bull sharks have very sharp, serrated, triangular teeth

that are located in rows inside the jaw.

The first two rows are used to attack their prey.

The other rows are on stand-by to rotate in, as needed,

replacing worn-down, broken or lost teeth.

This endless supply of teeth produce a dirty bite.

They are full of germs and can cause massive infection.

It's just too risky to have shark teeth

penetrating a human bone.

It's just too many germs involved

for them to roll the dice.

Four weeks in hospital, six surgeries in two years

and a constant need to understand what happened,

why it happened,

leading him to a greater understanding of sharks

and what it really means to be a survivor.

It doesn't know what it's doing.

I was a mistake, I was just a shadow to it.

It's got eyes out here on the side of its head.

It can't see anything.

[Richard] All sharks have the six senses -

have our five senses plus its electrical sense.

But what sort of defines them

is, you know, the tiger shark does the tropics,

the bull shark does the inshore coastal waters

and the great white does the cooler waters.

So those three species

have all our marine environments covered.

Research is showing that bull sharks travel great distances

and have been found to return to the same spot each year.

During the warmer months,

they are able to go further down the Australian coast

looking for prey when you least expect it.

Just look for the signs in the water

and look for the lifeguards, swim in the patrolled areas.

If there's signs there of baitfish and birds,

ask the lifeguards.

If you're worried, ask the lifeguards.

Just surf at a patrolled beach.

You can't avoid it, really.

If it's gonna happen, it's gonna happen.

But I think you can lessen your chances.

I'm more acutely aware of life's short.

You know, it really is.

It can be just gone in a blink, you know.

And I don't miss out on stuff anymore.

Straight to the top.

The bull shark is one brute no-one wants to encounter.

There are survivors. There are victims.

This hungry beast is aggressive

and knows no boundaries.

Down goes the dugite to number two

and the Johnston's crocodile falls to third.

But will they keep their spots?

Up next, a seemingly innocent fellow

that packs a big punch.

But will it be strong enough to hop to the top?

Australians love to hate cane toads.

They've invaded a large region of the country

and are marching defiantly into new territory.

Harmless if left alone,

but the poison could trigger the end of your life.

They've got this incredible chemical arsenal

that's capable of killing a large human.

There's a lot of poison in an adult cane toad.

The shoulder glands on these little guys

actually contain easily enough poison

to kill an adult human being and to kill them very quickly.

Cane toads are among

the biggest frog species in the world

with the female toads

being significantly larger than the males.

The females have quite smooth skin,

whereas the males are warty and rough

and have a couple of pads on their toes

to attach to the females during mating.

Another distinction

is that if you happen to pick up a male toad,

he'll sound out a special call that the female cannot make.

In reproduction, the females usually lay one clutch a year

that typically contains more than 30,000 eggs.

At every stage of their development -

eggs through to adults - the toads are poisonous.

When a predator takes the bold move to attack a cane toad,

the toads will blow themselves up with air

to make themselves look larger

and more of a target to be left alone.

But if the predator then seizes the toad,

the poison in their shoulder glands will be pushed out.

But do not believe you'll be safe from the poison

if you do not squeeze the toad.

The toad can actually push it out itself, can squirt it out,

and that poison is desperately painful

if it hits you in the eyes or in a cut on the skin,

and it can cause a heart attack if it's eaten.

It's a very fortunate thing that toads are reluctant

to use this arsenal that they carry around with them

because they really are a very potently poisonous animal.

There's a story that's been told over the years

of a first-year medical student

on the east coast of Australia

who was in a lab class with his fellow students

taking on a project to dissect a cane toad.

The toad he was working on was female,

and his classmates took advantage of this

and dared him to eat the toad caviar.

He challenged his friends to pay a dollar each

for him to accept the dare.

They were quickly on board.

20 minutes after consuming the eggs,

he had his first of three cardiac arrests.

He was rushed to the hospital

and treated to intensive care for just over a month.

[Rick] You could be killed very quickly.

Essentially it interferes with very basic chemical processes

in the cells,

and even quite large predators,

like the big freshwater crocodiles, die very fast.

The good news to this story

is that cane toads really don't want to harm you

unless they're forced into it.

This is the classic example of a dangerous animal

because when you try to kill it, it will defend itself.

Prior to 1935,

no-one in Australia needed to fear a cane toad.

But in that year, 102 toads were introduced to Cairns

from the Americas

with the hope they would control the beetles

destroying the local sugarcane crops.

The plan was a flop,

but the survival of the toads is a monumental success.

[Rick] We've now got a couple hundred million toads

right across tropical Australia.

So even though they came from the rainforest,

they've managed to invade the driest continent on Earth.

They've evolved to travel faster and faster.

In the early years, the toads were expanding

at about 10km a year.

Now it's about 60km a year.

They've evolved longer legs, they're more active.

They're a remarkable example of rapid evolutionary change.

If you do encounter one of these beasts

travelling across Australia, leave them alone.

The consequences could end your journey.

[Rick] If you were unlucky enough or foolish enough

to get cane toad poison into your eyes,

you'd really want to get it out as soon as you can

using fresh water and as much of it as you can get.

But you might want to start thinking about

heading off to the nearest hospital

because this really is deadly stuff.

It's no match for the strength of the bull shark

or the supremacy of the dugite,

and alongside the Johnston's crocodile,

despite being known to kill one or two,

the toad is way less of a threat to humans.

But get ready - about to take center stage

is the secret weapon of our tropical waters.

Small, almost impossible to see

and ready to infiltrate the enemy.

It began as a wonderful family holiday,

enjoying the pristine beauty of Fraser Island

off the Queensland coast of Australia,

and quickly turned into a nightmare

of unknown proportions.

Haley was straight into the water,

we had a little paddle up to the knees

and splashed around.

It was crystal clear, the water.

Beautiful hot day.

But 20 minutes later,

the dangers that lurked in the idyllic conditions

made their presence known.

Haley came running up the beach holding her arms,

screaming, saying:

"I've been stung, Mummy, I've been stung."

And then started going quite crimson-y red.

She says: "I can't breathe, Mummy."

And, well, then I just panicked.

Small in size but with a massive punch of pain,

Haley had encountered one of the most feared animals

of Australia's tropical waters.

I often refer to them as designed by the devil.

They're an animal that you never see, you get nailed

and you don't know about it till 20 minutes down the track

and then your whole world goes to hell in a bathtub.

It's just an awesomely badly designed animal

from a human perspective.

While Julie was trying to keep the situation calm,

Haley's father Matt was contacting emergency services,

desperately trying to get help for his daughter.

40 minutes later, what seemed like an eternity,

the rescue chopper carefully lowered onto the beach.

They had mentioned the word 'irukandji',

and, I mean, I'd never heard of what an irukandji was.

Extremely venomous,

the irukandji was identified by Jack Barnes in 1964.

In his experiment

to accurately classify this animal,

he allowed the tiny jellyfish to sting himself

as well as his son and a local lifesaver.

All three ended up in hospital.

To the uninitiated, the spell of the irukandji

is a sensation of unexpected magnitude.

When you're stung by an irukandji,

it's not that the animal is hunting you -

it is an accident.

If it comes into contact with you as a defense mechanism,

it will sting you.

To the initiated, knowing you've been stung

is the beginning of hell.

I know exactly what's gonna happen.

I've been there 11 times.

I know exactly what's gonna happen.

It's a really interesting syndrome

because what happens when you're first stung,

it's a mild sting.

And you'll see it, people get stung on the arm,

it'll be: "Oh, yeah, something stung me."

And that's about the extent of it.

I think we need to go, Teresa.

It stung across the bottom of the lip.

[Teresa] Alright.

See animals about 2m or 3m down.

[Teresa] Yeah, yeah, I saw a few.

Get out of here, I think. Need some vinegar.

Want to throw me that...

But that's just the start.

About 15-20 minutes later, the trouble begins.

Everything goes wrong.

Symptoms include severe cramping, vomiting,

nausea, lower back pain - your entire body is affected.

There is no escape.

And this feeling of impending doom,

that something is seriously going to go wrong.

Oh, dear.

So that comes in and you get that under control

and all of a sudden it ramps up a level.

And so you think: "OK, it can't get any worse."

And then it ramps up yet another level.

I've described it like I've often had an elephant

sitting on my chest.

So you're sitting in a hospital bed

with some emergency physicians

giving you large doses of opiates,

things like morphine, pethidine,

things of that nature.

It's just starting to take the edge off it

and all of a sudden it goes up a level.

I get severe pins and needles through my joints,

of my knees, my ankles, my elbows, my wrists.

You can't get comfortable.

My last trip, I was still throwing up

18 hours down the track.

If someone had've given me a gun, I was outta there.

I just wanted off the planet.

Associate Professor Jamie Seymour

has spent many years at the forefront of research

in marine biology.

He knows what to expect.

For Haley and her family,

it was an incredibly mystifying experience.

By the time Haley reached Hervey Bay Hospital,

her heart was beating twice the normal pace,

her hands and toes were blue,

her lips were blue, her face still crimson,

her eyes bloodshot.

Delirious, she was sweating profusely

against the increasing pain.

I thought I was like gonna die

because I tried to keep my eyes open

but I was sleepy.

Every time she tried to move me, one of my body parts,

I felt pain.

If you swim anywhere in the tropical waters of Australia,

the east coast, the west coast,

across the top of the country,

you risk being stung by an irukandji.

They are so small, you won't even see it coming.

It was surreal in the fact

that you can't believe this has happened.

You don't know how it's happened.

It's not a dream. It's a nightmare.

When they took us to one side,

it brought everything to a standstill.

We thought we could possibly lose Haley.

I just thought: "Is she having a heart attack here?"

Because the reaction of that is as if, to me,

it felt like these are the last breaths she's gonna take.

If you look at irukandji, they fall into what's referred to

as the little box jellyfish.

So a big animal is probably about the size

of your thumbnail.

Distinctly different from big box jellyfish,

they've only got one tentacle

off the corner of the body, or the bell.

Now those tentacles certainly can be upwards

of three-quarters of a meter long,

but they're about the thickness of your hair.

So you think of this animal

that's about the size of your thumbnail,

completely transparent,

with four tentacles that are about that long

that are as thin as your hair, that you can't see.

They have stinging organelles on their tentacles

but they also have it on the bell

of the body of the animal.

So any contact at all with this animal

is going to result in your being stung,

and any sting from this animal at all

is going to result in you being at hospital.

After three days of treatment,

Julie and Matt waiting anxiously,

agonizing over the outcome, a breakthrough.

I thought: "Her hair's dry."

It's strange, it was the first sign

that I thought: "She's not sweating."

And I thought: "We're on the road to recovery here."

She survived it, yeah.

There's only been two deaths that we know of

from irukandji syndrome,

and they've both occurred in Australia.

The overwhelming characteristic for victims

is intense pain throughout the body,

and there's very little that can be done

to ease the suffering.

However, about 10%-15% of people

will develop cardiac problems,

so going to the hospital is vital.

Research shows that it doesn't seem to matter

if it's a child or an adult that's stung.

It's a venom load from the jellyfish

that causes the problems.

[Jamie] The syndrome, it's interesting,

can range from simply being feeling unwell

through to death and anything in between.

The biggest problem with trying to treat these people

is we're never too sure

where you're going to be on that spectrum.

We've had two people in the water at the same time

stung by the same jellyfish.

One person really had a little bit of pain,

there was no problems at all.

The other person spent four days in intensive care.

The irukandji is not an animal to be taken lightly.

Whilst it's not going to attack you,

if you get in its way,

your pain threshold will blow every limit.

It's transparent, the size of your thumbnail and dangerous.

Australian beaches are signposted with warnings

for good reason.

Whatever beach that has jellyfish, I won't swim in.

Certainly able to take you by surprise,

the irukandji is nasty.

It's going to slide its way up to number four,

knocking the cane toad down to five.

It's very unlikely to kill you,

but the excessive pain factor

gives this creature its battle stripes.

Taking on the pack, enter the next contestant

with its weapon drawn.

Probably the ultimate weapon

in terms of the marine environment in Australia

is the sawfish.

It's a type of shark and it's got this long rostrum,

big, long nose, and it's got these wicked teeth,

big teeth, that go down the whole side of the saw.

Sawfish are found in the tropical waters

of northern Australia in the murky inshore areas.

And if you're a keen fisherman, watch out -

it's an encounter you don't want to experience.

[Richard] People, when they've caught them on fishing lines,

brought them in

and the sawfish, as soon as it feels threatened,

will just start flicking this blade around.

So a lot of people have been impaled by these blades.

These animals can get over 5m long.

That means the saw blade is longer than me.

What's happened a lot in the past is that the fishermen,

when they've caught them in nets or even trawlers,

have shot the animal to deal with it

and then have to hack it apart to get it out of the net.

The sawfish is in a group

which is halfway between sharks and rays.

Their gills are on the underside,

so, technically, they're a ray.

The tail is very shark-like,

but the front end of the body is very much flattened out.

Sawfish live in both salt and fresh water,

usually travelling upstream to breed.

Juveniles are often 1.5ft long at birth

and as they grow older, move downstream

and ultimately end up out into the ocean.

They sit there on the bottom

and they just use this as the ultimate blade,

so once a fish comes too close to them,

they'll strike at it in just a fraction of a second

and just hit it and keep hitting it

and just massacre the fish,

you know, cutting it into pieces and then feed upon it.

Their teeth are razor sharp and are basically there

to puncture and destroy their prey.

In defense, the saw is a destructive weapon

in a world amongst bull sharks and crocodiles.

[Richard] Because the sawfish

are living in the northern tropical waters,

which are really, really murky,

they're not relying on their eyesight,

so they're sitting there

and they hold the blade slightly up,

but the blade is covered in the electrical receptors.

And so as soon as the sawfish feels

the electric field of a fish close enough to it,

it can actually tell the size of the prey

by the size of the field given off,

and then they'll strike at it.

It's not just one strike, in the blink of an eye,

they'll hit it like half a dozen times,

so it's like bang, bang, bang, bang, bang.

The sawfish can swing the whole blade

and they can pivot about halfway down their body,

so they can strike at 90 degrees all around them

in the blink of an eye.

And when you think about how fast that blade

is travelling through water, which is very viscous,

that's a lot of pressure and a lot of power.

The power of the sawfish

has been seen since the days of the dinosaurs.

There's evidence of teeth being embedded

in the skulls of the dinosaurs

that were specialist feeders on the sawfish.

Today the sawfish is critically endangered,

mainly due to commercial fishing.

It's not because the fishers are hunting the animals

but more the case that the animals

get tangled in the nets as bycatch.

In years gone by, the rostrum was often cut off

and kept as a trophy -

a barbaric act of cruelty,

as the fish would no longer have the ability

to defend itself or catch its prey.

You often see the blades in people's homes

in northern Queensland, where it's being kept as a souvenir.

And I know of one case where two young boys

were having a swordfight with one,

and one brother hit the other brother with it

and basically impaled him on the blade.

So the sawfish had been dead for many, many years

and still had its revenge.

The sawfish bumps the cane toad down to number six,

but, despite its obvious physical advantage,

will only go as high as number five.

The irukandji holds its position at number four,

as does the Johnston's crocodile at number three.

Claiming second spot is the dugite,

with a poison that if left untreated will kill you.

But overwhelmingly taking the top spot

of most dangerous animal is the bull shark.

This is a monster that lurks in murky waters

and will most likely attack if you're nearby.

With all of our Australian animals,

there is a fear factor.

But keep in mind they're unlikely to harm you

unless you're unlucky enough or foolish enough

to get in their way.

Some are more aggressive than others,

some will take you by surprise.

Most of them will run from you,

but if cornered, they'll strike.

Be cautious, take note of the warnings

and show respect.

Admire these creatures for their majesty,

their power and their skills to survive

as we count down the list

of 72 Dangerous Animals Australia.

Captions by CSI Australia