02x00 - Yucatan Peninsula + Pacific Reef, Canada

[bunniefuu]

[instrumental music]

- [Narrator] Coming up on
Jonathan Bird's "Blue World".

Jonathan searches the world

for the most venomous fish in the sea.

Then he goes in search
of cold water sharks.

But first he explores
the underground rivers

of the Yucatan Peninsula.

All of this today on
Jonathan Bird's "Blue World".

Meet Jonathan Bird,
[instrumental music]

one of the world's top underwater
nature cinematographers.

Traveling the world on assignment

for all the major networks,

he is an Emmy Award-winning authority

on the underwater world.

In freshwater or salt,
reefs, wrecks, or caves,

Jonathan documents the
world beneath the waves.

Welcome to the "Blue World".

- I'm here in the jungles of the Yucatan,

which is not the kind of
place you'd normally expect

to find an underwater kind of guy like me,

but flowing beneath these forests

are incredible underground
rivers and in places,

holes in the forest floor like this one,

provide access to an amazing unseen world.

The holes in the ground are called cenotes

from a Mayan word meaning sacred well.

But not all cenotes look
like a hole in the ground.

Some appear at first to be ponds.

Yet they all share one common trait,

their openings to underwater
caves and caverns.

Mexico's Riviera Maya
in the Yucatan Peninsula

is a vast rainforest filled
with hundreds of cenotes.

There are thousands of miles
of underground rivers here.

My adventure begins first
thing in the morning

at H2O Pro diving in Tulum,

where we load our gear into a van

to begin the journey out
into the middle of nowhere

towards the cenote.
[instrumental music]

My guide, Marco Wagner is an experienced

cave diving instructor who
will keep me out of trouble

with a safe introduction to
the sport of cenote diving.

So I can hardly wait to see this thing.

Unless you're specially
certified for cave diving,

you should only dive with a local guide

who knows the cenote well.

Today we're diving a famous
cenote called Calavera.

- Calavera means translated skull,

and you see the big mouse
and to see the small ice,

this older small ice where
we see that in the dive

where the light beams are coming in

and they look like laces.

- Wow, this is really
way out in the jungle.

How do you think anybody found this place?

- I mean, they get explored
by the owners of the land,

also itself.

Say this covers as a cenote

because they have huge
pieces, huge chunks of land,

and actually when they
chopped the trees down

and they make trails, they
found the cenote also from,

cenotes are here for
the ancient Mayans also,

which were like sacred wells for them.

That's where the cenote
is coming from the word.

It's coming from the Mayan word cenote,

that means sacred well.

- So the Mayans, this was
a really important source

of water or?

- They also used the groundwater as well,

but also for sacrificing for the goats,

some cenote were used.

But there's still the groundwater

also still comes from
this underground rivers,

what we have here in the peninsula.

- Wow, that's cool. It's deep too.

So we're gonna have to
jump down. How far is that?

- That is about 2 meter,

- Echo!

Oh yeah, that's gonna be fun.

[upbeat music]

Now it's time to begin our dive.

We grab our gear from the van
and suit up near the road.

Marco is wearing double tanks

and all kinds of cool
technical cave diving gear.

Me, I'm just wearing my normal scuba gear

and a few extra flashlights.
[upbeat music continues]

The walk-in was plenty long

and hot enough when I
wasn't wearing my dive gear.

That water is gonna feel so good.

Marco gives me some last words of advice

before I take the plunge.

I think I'm more worried
about the 10 foot drop

into the water than the dive itself.

Cliff diving. Woo hoo!
[water splashing]

[bubbles gurgling]

Yeah, that's great!
[diver chuckling]

The water's extremely clear.

I adjust my camera lights

and follow Marco down below the earth.

[suspenseful music]

As we enter the cenotes cavern,

I realize that I'm truly
heading into another world.

This is not my area of expertise.

I follow Marco carefully
and pay attention.

We've brought some humongous lights

to help illuminate the
cavern for photography,

and they really help
show what it looks like.

It's beautiful.

The tunnels were formed
by water rushing through

and dissolving the soft limestone,

but the intricate decorations
hanging from the ceiling

called stalactites can
only form in a dry cave.

Thousands of years ago
during the last ice age,

the water levels were lower

and these very caves were bone dry.

That's when these impressive
stalactites were formed.

On a visit to a dry cave,

I can observe the actual
growth of stalactites,

but it's pretty slow.

It works like this.

When it rains up in the rainforest,

the water percolates through the limestone

and along the way it
dissolves a little bit

of the limestone.

Then it drips from the roof of the cave,

and over thousands of years, each drip

leaves a little bit of limestone behind

forming an icicle like
structure called a stalactite.

They get longer and longer
and longer with time.

But the water continues to drip

and eventually it hits
the floor of the cave

forming a little bump,

and that bump gets bigger
and taller and taller

forming sort of like an upside down icicle

called a stalagmite.

If you wait long enough,

the two of them keep
getting longer and longer

until they connect into
what is called a column.

At the end of the ice age,

the sea levels rose

and so too did the groundwater
levels in the Yucatan.

Soon these huge subterranean
caverns filled with water

leaving the stalactites frozen in time.

In some places, the caverns
have huge air pockets

where the water doesn't
go all the way to the top.

Here, we can surface for a
breath and take a look around.

Some of the cess can even
be explored by snorkelers.

Good buoyancy control in
the cavern is essential.

The limestone formations
are incredibly beautiful,

yet fragile sculptures.

The formations took
thousands of years to form,

but a single careless fin
kick could destroy them

in seconds.

So we must kick gently
and stay off the bottom.

The floor of the cenote is
covered in super fine silt.

Swimming too close to the
bottom would stir it up

and reduce visibility to zero,

which could be very dangerous.

[enchanting music]
As I follow Marco deeper,

the water starts to get
weird and blurry looking.

Many of these underground rivers

make their way to the ocean.

At some point along their journey,

the water transitions
from fresh to salt water.

Salt water and fresh water
have different densities.

The interface between the
two different densities

can cause an optical
condition called a halocline,

where the water appears blurry.

It's a weird swirly foggy haze.

I follow Marco down below the halocline

and into the salt water.

I can taste the salt on my lips

and the temperature is
about five degrees warmer.

Soon we reach the Swiss cheese room.

Down here, a chemical
reaction with the salt water

eats away some of the limestone

creating thousands of holes in the rock

and the unique Swiss cheese appearance.

It's a completely
different kind of formation

than I saw in the freshwater
part of the cavern.

As we swim into the far
reaches of the cenote,

we eventually reach a point

where we can no longer see
sunlight from the opening.

This has now become true cave diving,

a much more dangerous activity.

Here we find a sign warning divers to stop

and go no further.

People have become lost

and drowned in these vast labyrinths.

This is as far as we go.

Turning around, we head back
out towards the entrance.

[serene music]

Just before we reach the light of day,

we find some Mayan pottery on the bottom,

probably thrown into the cenote
as an offering to the gods.

The Mayans believe that the were pathways

to the underworld.

Offerings of gold, food, pottery,

and even humans were made to
the gods through the cenotes.

[serene music continues]

With my scuba tank getting low,

the time has come to leave the cenote.

So I head back to the surface.

In the shallow water
just below the jungle,

tiny fish come over to check me out.

Some of them nibble on my hair and ears.

They must be really hungry if
they think I look like lunch.

Wow, I can't believe all
the cool things I saw

in this cenote.

Who would've thought that there's so much

amazing stuff hiding under
the floor of the forest?

And even though I'm done
with my diving for the day,

I think it's time for one more dip.

Woo!
[water splashing]

- [Narrator] Next on Jonathan
Bird's, "Blue World".

Jonathan heads to Canada to
search for Greenland sharks.

But first, he searches for the
world's most venomous fish.

- Most fish are completely harmless,

but there are a few species

of extremely venomous fish that can sting.

In many cases, this venom is so powerful

that it can actually k*ll humans.

The most dangerous fish in the world

live on Pacific coral reefs.

Let's go take a look.

[water splashing]

Heading down, I begin my
search for venomous fish.

Most are well camouflaged
and hard to find.

With much assistance from
an experienced dive master,

I find a stone fish
well hidden in the reef.

It can change color to
match its surroundings.

Unless you know exactly where to look,

you will never see a
stone fish until it moves.

Incidentally, touching a stone
fish like this is dangerous.

The reef has a few dangerous characters,

and the stone fish is by far
one of the most dangerous.

The expertly camouflage stone fish

is the deadliest fish in the world.

Its dorsal spines contain
a highly toxic venom.

Its body is shaped like a blob

and it hobbles more than swims.

Sometimes stone fish bury
themselves in the sand,

their ambush predators, holding
perfectly still for hours,

waiting for something
bite-sized to swim by.

[slow instrumental music]

The stone fish has a sting

so powerful it can k*ll a grown man,

and the pain is incredibly severe.

The stone fish has a
slightly less toxic relative

called a scorpion fish.

It can still sting humans,
but it's rarely fatal.

It's just really painful.

A small group of damsel fish
are hovering near the reef.

But nearby, watching
and not moving a mussel

is a scorpion fish.

His perfect camouflage is a result of skin

that can change color to
match the surroundings.

The only thing that gives him away

is the slight movement of
his gills as he breathes.

On top of his body,

his dorsal fin contains
the venomous spines,

the armor, to back up the camouflage.

He's watching the damsel fish

who are blissfully
unaware of his presence.

Soon a damsel fish comes too close.

Not far away, I find a lion
fish hiding in the coral.

If those needles all
over the fish look sharp,

I can assure you it's because they are.

Not only that, each one is
like an independent syringe

ready to inject venom into any animal

foolish enough to try to eat a lion fish.

Almost nothing can prey on these fish

once they're fully developed.

During the day, they
generally don't do much.

But at night, things change.
[ominous music]

A small fish on the sand

is blissfully unaware of the predator

emerging from the darkness.

Like its namesake, the
lionfish pounces on prey

and easily consumes its
victim in a single gulp.

Small fish don't stand a chance.

[slow instrumental music]

Not far away from the reef,

an area of rubble and sand

provides a habitat for a
well camouflaged predator.

[ominous music]

The spiny devil fish is almost
invisible if it doesn't move.

But the hunting has not been so good here,

so it's off to a better spot.

The devil fish crawls along the bottom

using modified pectoral
fin spines as feet.

The spiny devilfish
sees a potential snack.

Unfortunately, a lined
cheek wrasse saw it too.

The devilfish is not pleased.

Not far away, a scorpion
fish is doing its best

to look like a rock.

A damsel fish barely escapes,
but not without injury.

The scorpion fish goes hungry,

but the spiny devil fish caught some luck.

The injured damsel fish has
taken a turn for the worse.

Although the stone fish, scorpion fish,

and lionfish are the most
venomous fish in the ocean,

they actually account for
very few injuries to people.

The fact is that if you leave them alone,

they'll leave you alone too.

Many more divers are
injured by sea urchins,

jellyfish, and crown of thorns sea stars

than by venomous fish.

But that's a story for another day.

- [Narrator] Don't go away.

Jonathan is going after one
of the coolest sharks around,

the Greenland shark.

- We often think of sharks

as creatures of the tropics,

living in clear, warm
waters near coral reefs,

or perhaps prowling the
shallows near a beach.

But sharks live all over the world

in all of the oceans from
the tropics to the Arctic,

from the shallows to the deep sea.

This is one such animal.

The Greenland shark named after the place

where it was first seen,

this massive carnivore lives
in the coldest water on earth,

the icy depths of the Arctic ocean.

But you don't need to go all the way

to the Arctic to see one of these sharks.

In recent years, divers have
been getting surprise visits

by Greenland sharks right
here in the St. Lawrence.

In the remote Canadian town
of Baie-Comeau in Quebec,

Greenland sharks come into
shallow water during the summer.

They enter a narrow deep bay
where the surface has darkened

by tannins from river runoff.

The visibility is not very good.

[upbeat music]

I'm going out to see if I can dive

with one of these monster
sharks in the St. Lawrence.

My guide to diving with
the Greenland sharks

is Sylvain Serwa,

a local dive instructor
and dive boat operator.

He's been diving with the
Greenland sharks for many years.

So Sylvain, how do we get the sharks

to come over to us underwater?

Do we have some bait or
some charm or something?

- We're not gonna use some
bait. Those sharks are curious.

They are predator.

They want to know what
invade their territory.

So they're gonna come to see us.

- Wait a minute, you're telling me

that they're just gonna
come over outta curiosity?

- Yes.

We're stranger in their territory,

so they're gonna investigate us,

turn around, and go back
to their daily routine.

- Wow. Well, this, I gotta see.

Let's go diving.

- [Sylvain] Let's go diving.

- Dry suits take diving to
another level of complexity.

We begin suiting up to
dive in the chilly water

of the St. Lawrence.

I need a dry suit to stay warm

because the water rarely
goes above 40 degrees.

That's cold.

[water splashing]

I jump into the water, grab my camera,

and head towards the bottom.

But something is wrong.

The water's not cold.

It's nearly 60 degrees.

Sylvain starts banging a
pair of rocks together.

He believes this will attract the sharks

because they're curious about the sound.

I see a kind of fish called
sand lance, but no sharks.

- [Camera Person] So this
time, no luck, Jonathan?

- Nothing.

We went down, we sat at about

and we looked all directions
into the darkness,

and I do mean darkness,
and we saw nothing.

I'm not one to give up easily,

so we head out the next day to try again.

Well, it's the second day of the trip.

So far, four dives, zero sharks.

Needless to say, shark diving
is not always predictable.

[water splashing]

I enter the water again
with my fingers crossed.

We head to the bottom,
engulfed in near darkness.

The bottom's covered in beautiful anemones

and a crab scurries away from my lights.

Sylvain does his best

to attract the sharks
clicking his rocks together,

but nothing shows up.

The water's just too warm.


- 55, yeah.

- Another dive with no sharks.

Normally I'd be thrilled with water

that's 20 degrees too warm.

I mean, who doesn't love warm water?

But these are arctic sharks,
they like really cold water.

So if I wanna find any sharks,
I gotta find some cold water,

and that probably means we're
gonna have to dive deep.

The next day we move the boat
a little further from shore.

Down on the bottom, it's so dark

my camera can barely
produce an image of Sylvain

in the twilight at 110 feet.

But good news, the waters
cold at this depth.

We only wait a few minutes,

and then out of the
darkness comes a big shape.

It's a Greenland shark.
I can't believe it.

Just like Sylvan said, it's
coming over to give me a look.

No chum, no bait, just pure curiosity.

What an odd looking shark
with a big round body

and a small mouth filled with rows

of tiny razor sharp teeth.

Most of my encounters with
sharks are in warm, clear water.

It's so weird to be
swimming with a huge shark

like this in cold, murky water.

This shark is more than 10 feet long,

but it's only a small one.

Greenland sharks reach a massive 21 feet,

making them among the
largest carnivorous sharks

in the world.

Yet studies suggest they
grow extremely slowly,

less than an inch a year.

So this 10 footer may be 100 years old,

and that's nothing.

Researchers think the
Greenland shark may live

to be 200 years old.

Even though it's said that
these sharks don't see well,

this one appears to be watching me,

his eye following my every move.

[instrumental music]

The shark stays with me for 15 minutes,

swimming slowly and not presenting
any threat to me at all.

He just seems curious.

But soon he picks up the pace
and I can no longer keep up.

He swims into the gloom
and my dive is over

because I'm low on air.

Sylvain and I head back to the surface.

Woo! I finally seen a Greenland shark!

We decided to go a little deeper,

get into that colder water.

And when we got down there,
it was freezing cold.

And then out of the darkness

came the big huge Greenland shark.

It was incredible!

On the way back to the dock,

I still can't believe what an
amazing encounter I just had.

Sometimes all the effort
is worth it in the end.

[upbeat instrumental music]