Way down in the Southern Ocean,
there's an island where time stands still,
where bizarre animals found nowhere else in the world
roam prehistoric rainforests.
What's that?
And beneath the surface of hidden rivers...
God, it's...
.. lurks a closely-guarded secret.
I'm afraid I'm gonna have to turn this off.
To unlock this island's mysteries,
I'll need to go where few have gone before,
to find an animal from the deepest depths of time.
And the incredible thing is they get even bigger.
I'm Jeremy Wade,
fisherman and adventurer.
For more than 35 years, I've travelled the globe hunting for monsters.
Look at this beast.
But mysteries are still out there.
There's something behind me.
I'm journeying into the unknown to reveal...
Yes!
.. the secrets hidden in these dark waters.
That, up ahead, is one of the most intriguing islands on Earth,
and this is my first time here.
I'm approaching Tasmania.
Ancient and densely forested,
it rises from the ocean, between frozen Antarctica
and the scorched Australian mainland.
Some of the seas around Tasmania
plunge to more than 18,000ft.
Inland, its temperate rainforests
lie frozen in time...
.. unchanged for millions of years.
There are hundreds of plant and animal species here
that are found nowhere else on the planet.
It used to be home to the mysterious Thylacine,
which is believed to have gone extinct
in just the last 100 years or so.
Also known as the Tasmanian tiger,
and some locals aren't convinced that they've gone.
But I'm gonna be looking for something that's possibly
even more bizarre and secretive.
Somewhere down there, in the multitude
of lakes, rivers and creeks lurks this.
The Tasmanian giant crayfish.
The world's largest freshwater invertebrate.
It can grow to the size of a dog,
with enough power in its massive claws to break bones.
Despite a ferocious reputation,
this armoured creature is teetering on the edge of extinction.
But I'm hearing there are still some alive.
I want to see one while they're still here to be seen.
I've been stepping into the unknown for more than 30 years,
and it still makes my heart race.
Right, how about this? This place is already fulfilling
its promise of a place with weird animals.
This is right next to within feet of the airstrip. Look at this.
It looks like a hedgehog, but it's something much more special.
This is an echidna. It's a monotreme, it's a mammal.
Think I might get a face full of dirt in a minute.
And these things lay eggs. I mean, how weird is that?
Right next to the airstrip.
But as weird and new as it is to me,
the echidna is nowhere near as rare as the giant crayfish.
In Tasmania's 26,000 square miles
of forests and plains, no-one knows for sure
how many are left.
And it's not the only thing that's hard to come by
in this island's waterways.
Loads of water,
but, apparently, very few species of fish in Tasmania.
Something like 25 native fish species.
To put that into some kind of perspective,
the island is about the same size as West Virginia,
where there are in excess, I believe, of 150.
Tasmania's bizarre ecosystem may only have 25 species of fish,
but it has 35 species of crayfish.
I've never been in a place where fish are outnumbered by these crustaceans.
Normally, when I'm after a monster fish,
they sort of depend on lots of other species, lots of biodiversity
to support them. But, here, in the absence of that,
I don't really know where to start.
This is a new challenge for me.
What do I know about crayfish?
In England, I've caught them from rivers,
but they're also found in lakes.
80 miles from where I landed,
there are two promising-looking lakes, fed by several streams.
This will give me a chance to investigate
a variety of Tasmania's freshwater environments.
A rocky stream with a good current and places to hide
feels like a great place to start.
There's what looks to be a sort of natural dam across there,
and above that is an area of much smoother water
which is probably... It's gonna be slower,
it's probably gonna be deeper. That looks like quite a good spot.
Because of overfishing,
it's illegal to catch any crayfish in Tasmania.
But I've obtained special permission to fish here
using baited open-topped nets.
I'm spreading my traps over a quarter of a mile of water,
and I'll allow time for the chunks of raw red meat
to do their work.
Right, I'm just gonna pull up the first trap.
I'll approach fairly stealthily because I don't wanna be looming
above it, breaking the horizon, that might spook it.
The other thing is, pull it in quite quickly and vertically,
otherwise there's a risk they might escape.
That's a big zero on that one.
Nothing here either.
Nothing.
Look at this. There's one.
I'm gonna take this over to the bank, get a better look at it.
My first Tasmanian crayfish.
This is about the size of crayfish I've caught at home.
This is about as big as they grow there,
whereas, here, they grow to super-monster size.
The giant crayfish I'm looking for may be 20 to 30 times heavier.
Now, imagine one of these the size of a dog.
But I'm not sure whether I'm holding a typical small crayfish
or a giant in the making.
I head downstream to the large lake at the end of the line.
Maybe there's more space for a giant here.
But it appears to be closed to the public.
There's a vehicle up here which looks like a sort of official vehicle.
Anybody around?
I think I can see some movement, actually, underneath there.
Hello? Hey!
Hello. Sorry, don't want to interrupt you
but have you got a couple of minutes? I do.
First thing I wanted to ask, what's the story over the sign back there?
It's all closed, no entry, that kind of thing.
Yeah, so we've closed off Lake Sorell
because, at the moment, we're undertaking
carp-eradication activities in here.
And carp are regarded as a noxious pest here,
an invasive species that needs to be eradicated.
I've caught carp in many countries.
They were first brought to Tasmania in the late 1800s
by early settlers.
The species has since thrived here
in the temperate climate, and has bred out of control.
During spawning, a single female
can lay 300,000 eggs in just two days.
As carp multiply, they displace native fish species
like Tasmania's galaxiids, and maybe giant crayfish, too.
But the fisheries officers here now think they're getting very close
to eradicating the invading carp.
So could this mean that native species of fish
and crayfish could be making a comeback?
Today, the officers are surveying the southern lake
to see what's in it and I'm eager to see what they pull up.
Jonah hopes he won't find any carp.
And I'm hoping to net a crayfish.
So where are we heading? Erm, so we're just going
on the inside of that point there. We've got a number of nets and traps
set around the lake, but we're going to check those ones first
and, yeah, just gives a bit of confirmation that the carp
haven't re-established in here, and see what else is around.
This island at the end of the Earth
has only just started to give up its secrets.
But just what else will its waters reveal?
Is that one there? God, he's just gone by.
I'm in Tasmania, in search of the giant freshwater crayfish,
a huge crustacean with bone-crushing claws.
On a lake in the middle of the island,
I'm looking for any indication that this rare freshwater beast
could be making a comeback.
Yes. I'll undo this.
Just herd them down towards me.
And throw it in.
There we are, there's a few there.
There's an eel. Yes. Beautiful.
Is it using its tail to climb out? Yeah.
Sort of have that backward slithering motion.
I've encountered eels before,
but I've never caught this species, the shortfin eel.
These are interesting, they spend part of their life in freshwater
and they breed in the ocean. Nobody here to this day
has seen eels breeding.
I'm gonna see if I can hold this one up now, it probably won't co-operate.
Like all eels, shortfins are carnivores,
and they do eat crustaceans.
So these could be feeding on juvenile giant crayfish.
But, unlike invasive carp, shortfin eels
are native to these waters. These are gonna go back.
These are actually an important part of the ecosystem here.
We've also caught something that I've never seen before.
That's a new species for me. This is a golden galaxid,
and the reason I've never seen them before
is because they're only found here in Tasmania.
In fact, they're only found in these two lakes.
A fascinating haul, but no sign of the species I'm looking for.
That's it. Exactly. There's a lot of fish in.
Man. There's a lot of fish in there.
There's a lot of fish. That's it. There's some big ones in there.
Just yell out what species they are and I'll write them down.
Rainbow trout,
brown trout,
some more rainbow.
Here we go. These are strong fish.
Trout are also an introduced species and another veracious predator.
Never tried this with a trout before, but with some sharks and catfish,
you do this, and it's fine,
it's breathing, but it just calms down.
Just gives me long enough to have a bit of a look before putting back.
So...
.. there we go.
What a lovely fish.
Lake Crescent, brown trout.
Beautiful fish. And it's off.
That fish, believe it or not, is the average size for this lake.
And there's not many waters where you could say that.
A fish like that on a line would be quite something.
But no crayfish of any kind
indicates that they have not been able to
re-establish themselves in this water.
So I'm going to have to look elsewhere.
Jonah tells me his old professor, an expert in crayfish,
may be able to give me some guidance.
He's based in Hobart, Tasmania's capital,
and its oldest and largest city.
The university here has a renowned zoology department...
.. containing a collection of preserved species
that is the life's work of Professor Alastair Richardson.
Come in.
Hello. Hi, Jeremy.
Hello. Thanks for making time.
I'm hoping Alastair can help me track down a living giant.
Where I come from, the UK, we're talking about a bigger land area,
we have one native species... One native species.
.. and I gather you've got quite a few species here.
We certainly have, yes. There are something like 35 species
described at the moment. There may be more still to come.
But in the land of crayfish, there is only one king.
So I'm guessing this is the boy. If I can lift it? So this is the...
That is the big boy. That is the giant freshwater crayfish, yes.
And this, I've seen lobsters before, but this came out of freshwater.
It certainly did. It came from quite a small stream.
Not the width of this table, that you could walk across,
and yet, this huge animal's living in it.
And there's bigger ones out there. There's bigger ones out there.
Since Alastair's giant came from a small stream,
I wonder again about the crayfish I found.
Is that the small giant crayfish?
It's certainly one of our, erm, spiny river-dwelling cray...
Have you got a picture from the dorsal side? Yeah.
A-ha. Yeah, no. I'm afraid it isn't. Right.
Because the giant freshwater crayfish has a ridge
down the centre of that rostrum there.
Makes it quite distinctive, easy to recognise.
This is one of the other two species in the genus Astacopsis that...
So it's a relative? Yes, yes, a close relative,
which is Astacopsis franklinii. OK.
Alastair tells me it's been over 30 years
since he found his giant crayfish,
and he doubts there would be any in the same place now.
But he does recommend another place to visit in Hobart.
Lots of information to think about, and that's really what I'm trying to do.
I'm trying to get as much information as I can,
to enable me to really narrow my search down.
The professor has told me about something
that I must see in the nearby state library.
Apparently, before European settlers arrived,
giant crayfish were plentiful across the island.
The archives might hold some clues
to the whereabouts of any remaining isolated populations.
Hello, hello. Caitlin? Yes, nice to meet you.
Curator Caitlin Sutton takes me to a floor
that is off limits to the public.
This is the grand safe.
Does this see the light of day very often?
No. Actually, it doesn't. We really try
to limit the light exposure on this book,
because the paintings inside are so delicate and fragile
that any light exposure can potentially damage them.
Even the natural oils on my fingers would be enough
to cause irreversible damage.
This is probably the single most valuable and iconic item
from our collection.
What's the story of the book?
Well, William Buelow Gould stole a coat
and was sent to Van Diemen's Land in 1827 as a convict.
He had painted several of the officers on-board,
and so, his painting ability soon became known in the colony.
So he stole a coat, and he was sent halfway around the world.
In the late 18th century, Britain sent more than 165,000
convicted criminals to Australia and Tasmania.
Many tried to escape, only to drown or starve.
Some, unable to survive on Tasmania's wildlife,
resorted to cannibalism.
Petty thief William Gould escaped that fate.
A talented artist, he was commissioned
to draw a record of the animals on the island.
These paintings by a convicted man
are the most comprehensive record of Tasmanian wildlife,
as the colonists found it 200 years ago.
The style is just so lovely and delicate.
And they really do give a sense of the real animal.
And, also, when you think about the circumstances
under which it was painted, it's just such a contrast
between the image itself and the brutality of the environment.
And then, it was one back from there.
I can already see some pincers.
This is the page I'm after.
This is the earliest known image of a Tasmanian crayfish.
More than 200 years old.
That is just so detailed..
Really frustratingly, there's no notes on this page.
But then, Caitlin shows me something else.
One of the first written records of the giant crayfish.
This is interesting. "As worthy of more than passing notice,
"occurring more or less abundantly in all the rivers
"upon the northern side of the island...
".. preferring deep still pools and reaches,
"in which it may shelter beneath submerged and partially decayed..."
So this is great, actually, this is just getting a picture
of the kinds of waters. Where are we?
"It follows closely in its distribution that of the blackfish."
This is brilliant.
North of the island and the blackfish.
That's really narrowed things down for me.
I'm guessing if I can find the blackfish, I can find the crayfish.
This feels like a breakthrough.
Tracking down fish is what I do.
And since the blackfish and the crayfish thrive
in the same undisturbed shallow waters,
landing a blackfish should mean the elusive crustacean
is hiding nearby.
I now have a clear direction, and that direction is north.
And the first thing I have to do when I get there
is start looking for a blackfish.
And, if I can find that, I should be very close to the giant crayfish.
I leave the capital behind me and head north.
Here, ancient forest stretches to the horizon and beyond.
This landscape is so incredible. One minute, you're in grassy upland,
and then, suddenly, you're in thick forest.
It really is like nowhere else I've been.
I'm entering the vast Tarkine wilderness.
But this area is hundreds of square miles of wild rainforest,
so I'll need to figure out how to narrow my search.
The thing about this country here is it's very sparsely populated.
Erm, I've not seen any houses, any people,
for quite some while, so my search right now is for a local.
My guess is that anyone who lives out here
has plenty of opportunity to become familiar with most of the wildlife.
Excuse me. Just a quick question.
Do you get blackfish in the waters around here? Yeah, we do, mate...
As I have found the world over,
local knowledge is key in any investigation.
He suggests a place just a few miles ahead.
Thanks very much. See you later, bye.
This is certainly very thick forest.
You can imagine all sorts of things hiding in here.
All right. This is as far as I can go.
Blackfish are nocturnal, so I could be in for a long night.
I wanna get a base camp set up while it's still light.
Some of the trees in Tasmania's forests
are over 5,000 years old.
They've been growing since the time of the ancient Egyptians.
And some of the plants here date back
to when this continent was part of Africa,
over 40 million years ago.
This ancient forest is so dense
that I'm worried it's going to be difficult to find anything here.
Listen to that.
Nothing.
Just a tiny...
.. tiny chirping over here somewhere. But, er...
.. the thing about wild animals...
..is they're just so good at hiding.
Is anything watching me at the moment, I wonder?
This looks promising.
Quite dark water. There's reeds around the edges.
There's a ripple. It's gone.
That was something just very briefly on the surface.
Is that...?
That's a platypus, that is a platypus.
It's the first time I've seen one in the wild.
They're smaller than I always imagine.
You think they're three or four feet long. They're not.
They're a foot-and-a half, or something like that.
The platypus is extremely rare.
And most people on this island will never have seen one in the wild.
That is an amazing bonus, seeing platypus.
I could easily get totally sidetracked
just trying to get even better views of these,
but I've gotta remember what I'm here to do is find the blackfish
and, hopefully, through them, get to find the giant crayfish.
I've never caught one before,
but, blackfish, like others in the perch family,
prefer to hunt in weedy, root-filled water.
This is nice. Secluded, definitely.
Absolutely flat calm because there is this wall of tall trees around.
Right, let's get some bait in the water.
Blackfish are carnivores and ambush predators.
So I've got a particular method in mind.
I've got a small popper on the end.
This is a little lure with a...
..a concave front end, so when you pull it,
er, it's on the surface, and it makes a bit of a gurgling sound.
But, also, if you're a fish down below, you're seeing
the silhouette moving across the sky.
Nocturnal predators like blackfish
become more active towards the end of the day.
If they're already on the move,
the noise and vibration of the lure should attract their attention
and draw them to the surface.
But nothing's coming up.
So I'll have to send my bait down.
What I'm gonna do is I'm gonna hang the bait under a float,
and the idea is to get that fairly close to the bottom.
And on the hook I've got a couple of earthworms.
The light has started to fade,
so I'm hoping the blackfish will be getting more active.
If blackfish are in the water, you know about it.
And this has been very quiet indeed.
But with the rain now starting to fall
and the sky darkening fast...
It's off.
That was a fish, for sure.
It's managed to take the bait.
But that's more activity than I've had the last couple of hours,
so let's get another bait out there.
My gut tells me I'm in the right place.
And I'm determined to fish on.
Without a blackfish,
my search for the giant crayfish hits a dead end.
Yes. Yes.
It's still there. Yes, there's a fish.
Let's see if I can swing it.
I think that is one. I think that is a blackfish.
Yes.
There we go, that's a blackfish.
A little bit reminiscent of a snakehead,
that sort of mottled pattern on the side.
It's very slimy. It's quite hard to hold.
Long dorsal fin with sort of spikes at the front.
Not very big eyes. Quite a big mouth.
It's a small fish, but the significance is big
because what this means, probably, from everything I've heard,
is that if it's blackfish country, it's also giant crayfish country.
Off he goes, leaving me with very slimy hands.
Finally, I'm in the right area.
But using crayfish traps is not permitted here.
Time to head back to camp and work out my next step.
Something is moving.
There, there, there, there, there, there.
There's something running.
I'm very curious to see what it is, but...
What's that?
I'm deep in the remote wilderness of the Tasmanian forest...
.. where I'm making my way back to camp.
There's something running.
I'm very curious to see what it is, but...
What's that?
I think I should try and find my way out again.
I'm thankful to be back in my tent...
.. up off the ground.
After a few restless hours,
I'm still curious about the night time noises.
But there's no monster here.
So this is what was hopping around...
.. outside the camp last night. That's a pademelon, which is a...
.. small version of a wallaby.
Very, very young baby in there.
I'm hoping this won't be today's only big discovery.
Having caught a blackfish, I must be in the right area
to track down a giant freshwater crayfish.
But I'm going to need help.
Giant crayfish are virtually extinct,
so there are strict laws preventing members of the public
from catching them.
But among the few people who live out here,
I'm hoping to find someone who's familiar with this prehistoric beast.
Hello. Hello there.
This might sound like a bit of a bizarre request, but I'm looking...
She tells me about a man who used to hunt crayfish,
but who now works to protect them.
She calls ahead to make the introduction
to researcher, Todd Walsh, who is based close by.
Morning. How are you, Jeremy? I'm fine, thanks. Yeah.
Pleased to meet you. Thanks for making time. Er, all set to go?
Pretty much, yeah. Todd is willing to help,
but he says I mustn't reveal the last-known locations
of the giant crayfish.
Right. OK, I'll follow you. Let's go. Yeah.
It's been illegal to hunt the crayfish
for more than 20 years.
But poachers still target them to this day.
It will take generations for the slow-growing crayfish to recover.
But Todd is determined to give them the best chance possible.
Part of the deal is, I don't let anybody know where we're going
and, to be honest, I'm lost anyway.
I genuinely have no idea where we are.
But to make sure that nobody possibly has a look at the background
and, from that, works out where we are,
I'm afraid I'm gonna have to turn this off.
Right, this is it. This is the moment, this is what it's all been leading up to.
Going and grabbing a crayfish, if we find one.
And, actually, just the act of saying that, grabbing it,
suddenly, it's becoming a little bit tactile.
I'm just thinking of crushed fingers and stuff like that.
Erm, so it's time to focus my mind.
Yes, I wanna see one of these things, but it's not gonna be...
It ain't gonna be easy. I'm somewhat apprehensive,
I have to say, which is the feeling I get with any fishing,
but I've definitely got it now. He's calling. It's time to go.
I'm being stealthy, but not too stealthy
because this is classic sort of snake territory,
and you don't wanna tread anywhere
where you can't see your feet.
Steadily downhill, downhill.
Generally, there's water eventually, if you keep going in that direction.
This is it. This is where we'll be looking. So, wader up?
Yeah, we'll need waders. Otherwise, it's gonna get pretty wet,
pretty quick. I'd suggest that water's pretty cold.
It's strange not to be gearing up with my rod and line,
and I feel somewhat lost without it.
These tangles of fallen trees
provide a vast labyrinth where crayfish can hide.
Forty centimetres of depth here and you can't see.
You got zero visibility before you start.
These log jams are always good.
Pretty shallow there.
Under that log there.
You see they've just got massive areas to hide.
They don't need to be in the water, they'll sit under the undercuts
and so...
This goes on forever, doesn't it?
It's ankle-deep water, you imagine it's shooting fish in a barrel.
But you look more closely, there's undercut banks,
there's a lot of places actually that you can't get to.
And the chances are we've walked past some, erm...
Yeah, we've just got to give it more time.
We decide to change tactics.
Todd has some equipment that might help us.
OK, so that's a monitor for this light
which has got a camera mounted on it as well,
and we can put this up into an undercut in the bank
and just have a look to see what's under there.
There we go. We got a picture. There we go.
Maybe under this tree root. Yes.
The picture's coming through OK, but the water visibility is poor.
So that goes in quite a way.
It's hard to tell what is down there.
This is going a long... İt's going a long way in.
A long way, a long way, a long way.
There's something there that looks a bit like a claw,
but it's just a branch coming out of the...
I'm sort of expecting, at any moment, just to see...
And this is what you do, you spot claws. Yeah.
So that's the first thing you like to see?
Yeah. Exactly. And you'll see the unmistakable shape of the claw.
When threatened, crayfish back up and face the danger head-on,
with claws raised, ready to attack.
It's hard to see under there, isn't it?
You got a counter current and all the debris
is moving sort of upstream.
The counter current is stirring up the water, reducing visibility,
something I need if I'm to stand any chance
of catching a giant crayfish.
Anything there?
The problem is there's all sorts of sediment on the branches
and this thing just knocks it all off and clouds it up.
Although the camera does provide us with a unique view,
it's slow-going in the murky water.
So we decide to pack away the kit and try a different area.
Volcanic soil turns the water an eerie red.
This low visibility and the sun's glare
make it even more difficult to spot anything
lurking beneath the surface.
Actually, Jeremy... Is that one there?
Yeah. Just facing you. I can see the claw.
The head's just going backwards. The head's this way.
Finally, after days of searching,
I get my first glimpse of the largest and most powerful
freshwater invertebrate on the planet.
All I have to do is grab it.
Get your hand behind the tail and slide up towards the head,
then they can't get their claws back and grab hold of you.
She's facing towards that bank.
Can you see her OK? Not very well.
God, I don't wanna grab it in the wrong place though, do I?
If I get this wrong, my hand could be crushed.
Is she facing downstream now? Downstream.
Yeah. That way? Yep. Yeah.
So, you should be able to slide along her tail.
There. Yes! Yes.
I've caught crayfish before but nothing like this.
This is a couple of pounds. Yeah, I'd say 2 lb.
And the biggest one you've seen? 10-11 lb.
So, she's about one fifth the size.
And is this one gonna hurt if I...? Probably take your finger off.
Seriously? Yeah. One this size? Yeah. Wow.
If this could remove a finger, I shudder to think
what an even bigger one could do.
I see she's a female.
So she's got a crop of eggs under the tail,
and you can see there. Yeah.
So she'll probably have 500 to 1,000. Wow!
Then, Todd checks to see if she's been caught and tagged before.
Right, let's take her to the bank and process her.
OK. And put her back in the water. Good start.
Amazing start. Really good.
So she's a new one. And how old would she be?
Er, I'll measure her.
And she is 6.5 inches.
So she'd be about 21, 22 years.
And has, until today, evaded capture by you.
Yeah. So that's encouraging, isn't it? Yeah.
So, is the next thing, you'll tag this one?
Yeah. I'll put a chip in her and put her back.
Each microchip tag contains a unique ID,
which enables Todd to estimate crayfish numbers and growth rates.
You are free to go.
I've seen my first giant crayfish and that is still sinking in.
And the incredible thing is, the more incredible thing is,
that wasn't even a big one. That was a medium-sized one,
which means they get even bigger.
And I can't resist the opportunity
to get my hands on a full-sized adult.
Todd says if we follow the main river,
I might get my chance.
Is that one there? It doesn't look like wood.
Yeah. Unbelievable. That's actually a nice one.
That's a good size.
Getting it out won't be so easy.
You can see, it's going back into that hollow log.
Most of it is hidden, but I can already see it's big.
Do you think go underneath this branch here, or go over the...?
I'd go over the top. Over the top?
Straight on to the top of its head.
God. He's just gone back.
Gone back in. Gone back in.
God, I don't wanna grab it in the wrong place.
I've got it. I've got to get it out now.
Hold on. There we go. Yes. Yes.
Who would've thought you'd need two hands to hold a crayfish?
This one is enormous.
And there's no way I'd want to tangle with these claws.
It's one of the largest Todd has ever seen.
He estimates it must be nearly 50 years old.
This one is a male. Two big differences,
the lack of eggs under the abdomen, but also, the size of those claws,
those pincers. Absolutely formidable on this.
It's one of the most incredible creatures I have ever held.
It's a bit alien-like, and I can hear its mouth parts moving.
Never seen anything like it in freshwater.
What a spectacular find.
I feel enormously privileged
to be holding one of Tasmania's last freshwater giants.
That was definitely worth coming halfway around the world to see.
My hope is that this incredible beast can live on
and remain hidden, deep in this lost world.
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