All language subtitles for remux-Mysterious.Islands.2024.S01E06.1080p.WEB.h264-EDITH.eng

[narrator] An uninhabited, muddy
little island in England

has a horrifying history.

Authorities believe that
there are hundreds of bodies

on the island.

The place is covered
in human bones,

skulls, and teeth.

[narrator] A shocking spider
discovery on an island off

Sri Lanka reignites an
age-old mystery.

- Previously, they've not
found the spider anywhere else

in the world.

Could it have traveled by air?

[narrator] Animal corpses
discovered on the shore

of a small Canadian island
baffle researchers.

At first glance, the wounds
appear intentional and precise.

What could be ravaging
these poor creatures?

[narrator] Isolated, scarce on
resources, islands are worlds

unto themselves.

Bizarre creatures, ancient
gods, and haunting ruins.

Baffling murders
and deadly spirits.

What will be discovered on
Earth's mysterious islands?

♪ ♪

[narrator] The British Isles,
over 6,000 islands

that have been
intermittently inhabited

since as far back
as 800,000 BCE,

the largest of which are
Great Britain and Ireland.

You probably don't know the
names of the smaller ones,

the ones that aren't much more
than uninhabited stretches

of marsh, mud, and rock.

But if you do find
yourself on one

that's barely above sea level,
you'll also probably find

lots of stuff in the mud,
like old bottles, plastic

containers, rubber boots.

And every once in a while,
people have even found

shrapnel from bombs
that struck the region

during the Blitz.

[narrator] But on one small
island, just about 40 miles

from London, you're
likely to see something

far more mysterious
than shrapnel.

In 2016, people sneaking
onto an off-limits avian

wildlife preserve found
themselves surrounded

not by birds, but by bones.

And these were not the
bones of wild animals.

The place is covered in human
bones, skulls, and teeth.

If you're actually
walking on the island,

there's an excellent
chance of you literally

tripping over them.

What happened here?

Authorities believe that
there are hundreds of bodies

on the island, which
isn't really a surprise

when you realize that
the name of the island

is a bit of a spoiler,
Deadman's Island.

Why are there so
many human bones here?

Could this be one of
those plague islands

you hear about, like Poveglia?

[narrator] When the
bubonic plague arrived in

Europe in 1347, the small
Italian island of Poveglia

became a quarantine
site for many

dying from the Black Death.

Even hundreds of years
after the plague,

the island remains
off-limits to visitors.

While both Poveglia
and Deadman's Island

are closed to the public,
that is sort of where

the similarities end.

Poveglia has a lot of
buildings, housing, a bell

tower, a hospital, and
it even had a fortress.

Deadman's Island is
less than a mile long

and just 650 feet wide.

It has almost no structures.

It's really just
mud and marshland.

Where would people
live or even die here?

If you walk across the
island when the tide is out,

you can see even more bones
jutting out of the mud,

some much smaller than others.

They're clearly from
children or young adults.

Why would anyone be buried
here, let alone children?

Despite the menace of the name,

this uninhabited mud
bank is currently a

protected wetland site
and a bird breeding

and nesting preserve.

But long before it was
an avian love island,

it had a much darker purpose.

[narrator] In the 1700s, the
British prison system was

nearing collapse and
part thanks to the

Waltham Black Act of 1723,

which we now know
as the Bloody Code.

It was an emergency
measure to punish crime.

It included serious crimes
like arson and murder,

but it also covered a
wide range of thefts

we might think of as
being pretty minor.

But in that era, there
wasn't much of a distinction

between the petty crimes
and the serious stuff.

♪ ♪

Basically, if a 10-year-old
stole a chicken

or a loaf of bread to
survive, they could find

themselves in jail.

[Anthony Cantor] As a result of
all these draconian laws,

prison populations swelled
until the prisons couldn't

accommodate any more people.

So the authorities came
up with the novel idea

of floating prisons
called prison hulks.

[narrator] A hulk, in the
language of the British Navy,

was a ship that was no longer
capable of full service.

Such ships were gutted of
all their military gear

and turned into prison
quarters for anywhere from

100 to 600 people.

On the prison hulks,
some of the prisoners were

to be there indefinitely.

Others were just held until
there was a merchant ship

big enough to bring them
to colonies like Australia

for forced labor.

Of course, we know
prisons don't offer

the most pleasant of
accommodations at

the best of times.

If you now imagine
all of that crammed

onto a dark, stuffy ship,
it's even worse again.

Apparently, the
hulks were far worse

than even the
Dickensian prisons.

The quarters were
crammed and filthy,

and the food and water
were often contaminated

with bacteria.

[narrator] Cholera hit
Britain in the 1830s,

devastating the country in
1832, and the prison hulks

were no exception.

Cholera is transmitted
by fecal matter.

Imagine how quickly that
disease would spread

in an enclosed space with no
proper sanitation system.

So when prisoners
were infected,

they were moved to the island
and left there to die,

which explains the bones,
but it doesn't explain

everything on the island.

[narrator] One of the many
mysterious things about

Deadman's Island is that
there are coffins on it.

In fact, the place where
most visitors land

is called Coffin Bay.

You can see the
rotting coffins

and pieces of wood
all over the place.

[narrator] Now with erosion and
rising water levels,

these bodies are also rising
up, but it's not the first time

their stories are being heard.

Locals have been telling
tales of Deadman's Island

for generations.

Legend has it that there
is a devil dog out here

with glowing eyes who
eats people's brains.

And some locals swear
they can hear wailing

coming from the island at
night, a wailing that they say

cannot be dismissed as wind.

Of course, if you find an
island covered in bones,

there are gonna be lots of
creepy stories about it.

But when you consider
that many of these people

had been thrown in jail for
things as inconsequential

as stealing a loaf of
bread, and that many of the

prisoners were children,

it really does make
Deadman's Island

seem much more tragic
than terrifying.

[narrator] No one knows what the
future holds for this island,

but as the climate changes
and water levels rise,

Deadman's Island may
soon be washed away,

taking the last of
its secrets with it.

♪ ♪

[narrator] Nestled in the Palk
Strait in the Bay of Bengal

between India and Sri
Lanka sits Mannar Island,

known for its pristine
sandy beaches.

- In addition to
being beautiful,

Mannar is a haven for
the natural world.

There are 3,600 species of
plants and animals here,

flamingos, mangroves, and five
species of endangered turtles.

It's actually one
of the planet's

most biologically
diverse coastal regions.

[narrator] With this in mind, a
team of Sri Lankan researchers

head to the island in 2012,
intending to survey one of

the facets of its diversity,
the spider population.

As they catalog the wide
range of arachnids,

they encounter
something surprising

in the hollow of a tree.

Inside, they find a Rameswaram
ornamental tarantula.

Now, finding a spider in a tree
when you're studying arachnids

might not seem like a big deal,
but think about that name.

Rameswaram is a town in
India on Pamban Island.

That is 30 miles away
as the crow flies.

And that spider?

Until 2012, it was
thought to be endemic,

meaning exclusive to Rameswaram.

Previously, they've
not found the spider

anywhere else in the world.

It couldn't crawl over
water to the island,

so how did it end up here?

Could it have traveled by air?

Look at a spider.

It has no wings
and it can't fly,

so that should be the end of
that story, but it's not.

[narrator] In 1832, Charles
Darwin, while at sea,

encountered a surprising sight.

The deck of his ship was
covered in tiny spiders.

"I caught some of the
aeronauts' spiders,

which must have come
at least 60 miles.

How inexplicable is this
cause which induces

these small insects
to undertake their

aerial excursions?"

We should forgive Darwin
for calling spiders insects.

In his day, the spiders
were considered

a subgroup of the insects.

We now know that's
totally wrong,

but the point is, Darwin
did witness spiders

traveling long
distances in the air,

and since then, they've
been documented

two and a half miles
above the earth

and going out as far as
1,000 miles out to sea.

[Amma Wakefield] This
achievement is both beautiful

and frankly, a little
bit terrifying.

Imagine being caught
up in a breeze

filled with hundreds or
even thousands of spiders.

♪ ♪

But then we're back to
the whole no wings thing.

So how do they become airborne?

- Spiders shoot out silky
strands to make their webs,

but the same filaments
can catch the wind,

allowing the spiders
to take flight.

It's called kiting
or ballooning.

- Ballooning isn't just
the result of a spider's

ingenuity or tenacity.

It's a result of electricity.

[thunder rumbling]

[narrator] Every single
day, the earth is host to

electrical storms, which get the
air crackling with electricity.

It's thought that these
forces can create an electrical

charge imbalance between
the silk threads

and the surrounding air.

The idea is that the
electrostatic interaction

helps lift the silk strands,
taking the spider with it,

hence the term kiting.

♪ ♪

[Alison Leonard] It's
a decent theory until

you start thinking about scale.

Most of the spiders you'll see
ballooning are pretty slight,

but have you ever
seen a tarantula?

These are not small creatures,
so it might be pretty

hard to get them airborne.

Plus tarantulas don't even
spin those orb-like webs.

They mostly use their silk
to line their burrows.

[narrator] So it seems rather
unlikely that these large

spiders balloon
to Mannar Island.

However, there is another theory
about their presence here,

one that's both
historical and mythical.

For ships traveling
in the region,

the Palk Strait is a bit of a
thorn in their collective side.

If you wanna go from
the east coast of India

to Southeast Asia,
it would make sense

to round the bottom
of the continent

and scoot through
the Palk Strait

between Pamban and
Mannar Islands.

[Anna Klassen] Otherwise, you
have to take a circuitous route

and sail to the end of Sri
Lanka, only to come up again.

So going through the strait
seems like the obvious choice.

The problem is that
going through the strait

isn't possible for most ships.

The first challenge is that
it's just too shallow in spots,

but that's not the
biggest hurdle.

[narrator] There's a rugged
underwater barrier

that limits passage
through the strait

between Pamban and
Mannar Island.

It's a 30-mile-long chain
that emerges during low tide.

It looks like a spine.

Since the beginning
of this century,

this formation has been
the focus of heated debate

between historians, politicians,
and religious Hindus,

all arguing about its history,
meaning, and utility.

The formation is
known as Ram Setu.

According to documents
from the nearby

Ramanathaswamy Temple, there
was a causeway-like

bridge between these two islands
until 1480, when a hurricane

ravaged the region.

[Alison Leonard] A causeway
could explain how the tarantula

came to be hiding out in
the trees on Mannar Island,

but that theory prompts
another question.

Who or what made this causeway?

[narrator] One theory about how
this causeway was made

is found in the name
itself, Ram Setu.

Ram, or Rama, is a
major Hindu deity

and the hero in the
Hindu sacred text.

In the Ramayana, Rama's
wife has been kidnapped

by the evil 10-headed
monster, Ravana,

and taken to Lanka.

In order to save her,
Rama instructs Hanuman,

the monkey god, and
his monkey warriors

to build a bridge so Rama can
reach Lanka and save his wife.

The Ramayana was written
by the Indian poet Valmiki,

who lived somewhere in the
ballpark of 500 to 100 BCE,

and devout Hindus believe
it represents real events

that happened somewhere
between 1.7 million

and 3,500 years ago.

[Sarah Klassan] For the
faithful, the answer is
also found in the Ramayana.

In that text, the stones
used to build the bridge

are inscribed with
Lord Rama's name,

which essentially enchants them,
thus allowing them to float

and be moved into place.

[Amma Wakefield] The reality is
there actually is one rock that

floats, and it might be in your
bathroom right now, pumice.

[narrator] Pumice is created
when volcanic magma

with high gas content rapidly
cools and solidifies,

trapping gas bubbles inside.

That results in its porous
and lightweight structure

that has a lighter
density than water.

Translation - pumice
stones can float,

but after a while they take
on water and they sink.

So could the magic floating
stones of the Ramayana

just be large pumice stones?

[Alison Leonard] The problem
with this theory is that there

are no volcanoes in this
region, so there's no source

for pumice stone.

What else could have
created this causeway?

[narrator] The researchers
who found the spiders on

Mannar Island also suspect
that there was once a bridge

that connected Sri
Lanka and India,

only they believe it
was a natural one.

India and Sri Lanka
were once connected

and part of the
supercontinent of Gondwana.

[narrator] Around 180 million
years ago, Gondwana came apart

as a result of shifting tectonic
plates, creating continents and

leaving behind land
fragments like Ram Setu.

Much of the bridge is determined
to be built out of limestone,

which is also called
calcium carbonate.

That's the stuff that
the exoskeletons

of coral reefs are made out of.

So that's some solid
evidence that Ram Setu was

naturally formed.

The debate over how
the bridge was made

might seem like an
esoteric argument

that only academics and
the devout care about,

but it's actually a hot
button issue in the country.

[narrator] There have been many
proposals to create a shipping

lane canal through the
strait, so they would no

longer need to navigate around
the bottom of Sri Lanka,

dramatically reducing shipping
distances and transit times.

- For Hindus, this is
a catastrophic idea.

They believe that this
bridge is a tangible part

of their history and
their connection

to the gods.

- And it's not just the faithful
who are against this plan.

Ram Setu is part of the fragile
ecosystem in this region.

It's home to a diverse
array of marine life,

and it protects the coastline
from strong currents and storms.

- Some scientists fear that
the removal of the bridge

could have serious environmental
effects on the region,

something especially
dangerous in this era

of ever-increasing
climate change events,

like hurricanes or cyclones.

[narrator] It's clear that the
debate over Ram Setu

isn't likely to be
resolved anytime soon.

Thankfully, however the
Rameswaram tarantulas

arrived on Mannar Island,
they've already made

themselves at home.

The Outer Banks form
a thin land barrier

between the Atlantic Ocean and
America's eastern seaboard,

formed as the last ice
age came to an end.

They have since
protected the mainland

from the worst the
ocean has to offer.

- The Outer Banks are composed
of a number of islands.

One of them is actually
among the longest

in the continental US.

This is Hatteras Island,
located just off the

coast of North Carolina.

- This relatively flat,
sandy spit of land

used to go by another
name, Croatoan,

named after the indigenous
people that lived here

when the English first arrived
back in the 16th century.

[narrator] Archaeologists
are looking into the

country's origins, searching
for clues as to what became

of the first English
colony in America.

This is interesting
because as we know,

the first permanent English
settlement in North America

was Jamestown, settled in 1607.

But there was another
settlement that

predated Jamestown, and
that was the vanished

colony of Roanoke.

[narrator] In July, 1587, 118
settlers under the command of

John White landed on the shores
of Roanoke, roughly 50 miles

north of Hatteras.

They were making
a second attempt

to establish a
colony on the island

after a previous colony
of the same site

was unable to last a year.

Relations with the
local indigenous people

broke down as well.

They had actually killed
one of their leaders,

a man named Wingina.

So needless to say, it would
have imperiled their colony

as the English were
few, vulnerable,

and surrounded by
freshly made enemies.

This didn't deter the
second group though.

For some time, things must
have gone somewhat smoothly

because John White's
granddaughter was

born in Roanoke.

She was the first English
child born in North America,

and her name was Virginia Dare.

But not too long after they
had set up shop in Roanoke,

they realized it was too late
in the season to grow crops,

leaving them desperate
for supplies.

So John White decided to head
back to England to get them.

Problem was, when he got
there, the country was in a

full-fledged war with
Spain, causing a three-year

delay in his return.

When he finally did come
back, all that was left of the

colony were two cryptic
clues inscribed into a tree

and a fence post.

The letter CRO and
the word Croatoan.

[narrator] Prior to
leaving for England, John
White had decided that

if Roanoke had to be abandoned
for reasons of hardship or war,

the Maltese cross would
be carved into a tree.

Thinking that the settlers
had simply relocated

to Croatoan, he remarked,
"I greatly joy that I

have found a certain token
of their being at Croatoan."

Croatoan is the Algonquin name
for the island of Hatteras.

So John White figured he
would find the remainder

of the colony there.

But terrible weather and a
near-mutinous crew intervened,

and he was forced
back to England,

never to return
to the New World.

The lost colony of Roanoke
has become part of the lore

of America's origins.

But what actually
happened to it?

[narrator] Under the surface,
archaeologists discover

a number of artifacts that speak
to Hatteras' rich history.

Artifacts likely
made by the Croatoans

are found alongside the
firing mechanism of a musket.

They all date to the time
of the Roanoke colony.

[Anthea Nardi] There's also a
signet ring, a very personal

possession that without a
doubt must have belonged

to an English gentleman.

Could these artifacts
have belonged

to settlers of Roanoke?

[Alison Leonard] While the ring
has been dated to the

17th century, it's very
difficult to specifically date

many of the other artifacts.

They may represent a
large span of time

or entire different periods.

So we can't say for sure
that these artifacts

belong to the Roanoke settlers.

Considering how close
Hatteras is to Roanoke,

perhaps the settlers
ended up here.

Though given its small size,
it's unlikely that the

island could have supported
another 100 plus people.

There simply isn't
enough evidence

to say for sure either way.

Although a while ago,
some rather strange

evidence showed up.

[narrator] In 1937, a man
brought a stone to

the history department at
George's Emory University.

He said that he found
it in the woods

and that inscribed
on its surface

was a message from the
lost colony of Roanoke.

This is known as the Dare Stone,

so called because the
message on the rock

is from Eleanor White Dare,
the daughter of John White.

The stone is engraved
on both sides

and basically states that
both her husband and daughter

were killed in 1591.

And that most of
the colony had died

as a result of sickness and war.

- There are several
reasons to question

whether or not it truly was
written by Eleanor Dare

in the late 16th century.

The message is signed
with her initials, EWD.

And for us, this is
completely normal.

But for the English in the
16th century, it wouldn't be.

As this wasn't a typical
way of signing your

name at the time.

Also, the year 1591 is
written using modern numbers.

The practice of
using these numerals

didn't really become common
until a little later.

[narrator] Geologists have
also taken a look

at the stone's properties
to see what they can learn.

By cutting off one end,
they saw that it was a

bright white on the inside,
while the actual words

were much darker.

It would take a long
time for that brilliant

white color to fade once
the letters had been

etched into the rock's surface.

So this means that when the
stone was found in 1937,

it had been lying in the woods
for a good while already.

Though a skilled forger could
have used chemical stain

to make it a convincing fake.

Regardless of whether
or not this message from

the past is a hoax, the
explanation offered

by the Dare Stone really
isn't that far-fetched.

War, death, and disease would
have been a daily reality

for these early colonizers.

There are many
different theories

as to what became of the colony.

Some think that it was
attacked by the Spaniards,

or that the settlers
were either killed

or absorbed into
indigenous communities.

If they did abandon
the English settlement

and integrate into
indigenous communities,

it wouldn't be the
first or last time

that European settlers did so.

[narrator] Following the
settlement's disappearance,

John White delivered a
letter to Richard Hakluyt,

saying that the settlers
intended to de-camp

to another location, roughly
50 miles inland from Roanoke.

Exactly where this
supposed destination was

has been lost to history.

For unknown reasons,
White didn't really

expand on the location.

Maybe he didn't
even know himself.

[Alison Leonard] He did draw
a map of Roanoke and the

surrounding areas of Chesapeake
Bay and Croatoan Island.

But again, on this map,
there isn't any reference to

this mysterious destination.

But if you look
closely at the map,

you can see that there
are faint outlines

that are drawn on
top of the original.

These are what
we call patches.

They were a common way for
map makers at the time

to correct mistakes.

They would simply layer
a piece of new paper

on top of the old.

[narrator] Curious about what
mistakes White had corrected,

the First Colony Foundation
asked the British Museum

to further analyze the
map using spectroscopy

and other imaging techniques.

Multi-spectrum spectroscopy
essentially allows us

to understand the properties
of any given object.

By applying this new
technology to this old map,

you can see more than
what meets the eye.

[Anthea Nardi] You can actually
see beneath the patches.

The bigger of the two
revealed a correction

to the coast's topography,
but the smaller was

hiding an incredible clue.

[Anthony Cantor] Beneath the
little patch at the end of the

peninsula is a four-pointed
star, outlined in blue and

filled in with red.

It's located where the Chowan
River and Salmon Creek

flow into Albemarle Sound.

It's not much more than 50
nautical miles west of Roanoke.

[narrator] Thinking that there
may have been a settlement

on the shores of
Albemarle Sound,

between 2012 and 2019,
archeological digs were

conducted in the area,
indicated by the star

on John White's map.

The area received
the name Site X.

What's needed is evidence that
could be definitively dated

to the late 16th century.

But this is complicated
by the fact

that the first
English settlement

in this part of North
Carolina was in 1655,

almost 70 years after John
White sailed to Roanoke.

So there could be
deposits left by someone

other than the Roanoke settlers,
if they'd even been here at all.

[narrator] Excavations
revealed many artifacts

were made by indigenous
people, as well as those

of English origin.

Most importantly, however,
a relatively high

concentration of pottery
was also discovered,

items that were used by
families and regular people,

not the military.

European pottery in itself
is not that exciting a find,

but these ceramics do provide
something special in this case.

Their production dates can
help to establish a timeline.

[Anthea Nardi] The ceramics
found at Site X correspond to

the possessions of less than 10
people and were used for food

storage and preparation.

They have the very distinct
color that is associated

with what we know to be
Surrey Hampshire borderware.

We know that this
type of ceramic

was not imported into the
New World after 1624,

which means that they were
probably brought to America

by Roanoke settlers.

[narrator] The excavations at
Site X also revealed another

essential artifact.

Archeologists found
a small copper tube

that would have been used
to secure wool fibers.

These all amount to small,
but very significant finds.

This piece of metal is
what's called an aglet.

It's kind of like
what you would have

at the end of your shoelace.

This little thing is important
because it went out of fashion

in the first half of
the 17th century,

meaning that it could
definitely have belonged

to a Roanoke colonist.

- What appears to have
happened is that something

caused the settlers at Roanoke
to disperse across the region.

It's impossible to say
what the trigger was,

but life definitely wouldn't
have been easy on that island.

- Life would have been easier
if and when they integrated

with those indigenous
communities that accepted them.

But because no single
one would have been able

to absorb dozens
of people at once,

the English of Roanoke
would have had

to join various communities,
those at Site X and

on Hatteras Island,
likely being two of them.

And as for that patch
on John White's map

that revealed the
possible location

of the Roanoke settlers,
why was that made secret

in the first place?

While the map was
drawn by White,

it was done at the behest of his
employer, Sir Walter Raleigh.

And remember, White
also had his daughter

and grandchild there,
so he may have had some

personal stakes as well.

[narrator] Today, the
National Park Service Fort
Raleigh Historic Site

has an exhibition dedicated
to the vanished colony,

with the exception of
the known few at Site X

and perhaps Hatteras, what's
become of all the others?

A conclusive answer is unsure.

The settlers of Roanoke seem
to have vanished into history.

♪ ♪

In the heart of the wild and
unforgiving North Atlantic,

just a few miles off the
eastern coast of Canada,

lies Sable Island, a
26-mile-long strip

of sand and grass.

It's called the Graveyard
of the North Atlantic,

as 350 ships have been
dashed against the island's

ragged coasts.

With that kind of history,
it's no surprise that

there are boatloads
of ghost stories

about this place,

including one about
a shipwrecked woman

who wanders the beaches.

Legend has it that thieves
cut off her finger

to steal a valuable ring, and
that she's spending eternity

searching for both the
ring and the thieves.

- Despite how grim and
eerie that all sounds,

the island is also
quite beautiful.

Even the name is pretty, Sable.

Derived from the French
'sable', it means sand.

- There's certainly
a lot of sand here,

and not much else.

There's actually only a
single tree on the island.

You can't even visit
it without a permit.

Most of the people
on the mainland

have not set foot here,
and likely never will.

A 90-minute charter
flight to the island

costs $1,500 US, and
visitors aren't even

allowed to stay overnight.

[narrator] Sable Island's
remoteness makes a bizarre

discovery here in
1993 even stranger.

A local researcher who spends
a good part of the year

on the island is out on the
beach doing her usual patrol

when she crosses
paths with a seal.

Actually, a few of them.

[narrator] Between December and
February, up to 400,000 gray

seals come to the island
to mate and give birth.

It's the largest gray seal
breeding colony in the world.

Okay, finding a seal,
or even several seals,

on the coast of a
Nova Scotian island

is like finding hay in a barn.

This is the North Atlantic.
This is their playground.

But these seals aren't playing.

They're dead.

Now, around here, one dead
seal, even 10 dead seals,

is not exactly a
case for the CSI.

The ocean's a brutal place.

But what's startling here
is how these seals died.

They have been sliced open.

The bodies have
peculiar corkscrew cuts

that start at the head and
spiral around the body.

The wound goes right through
their skin and blubber.

In some cases, a chunk of the
skin and blubber is gone,

but the tissue and
muscle remain intact.

[narrator] By 1996, 400 such
carcasses had washed up

on the windswept beaches
of Sable Island.

And by 2001, the
number is over 4,000.

And it's not just
one kind of seal.

It's five.

They find gray, harp, harbor,
hooded, and ringed seals.

What could be ravaging
these poor creatures?

[Anthea Nardi] At first glance,
this looks like the handiwork

of humans, as the wounds appear
intentional and precise.

[Anthony Cantor] But if
you follow that logic,

there are a few problems.

First, how?

This is an extremely
remote place

with seriously
restricted access.

For someone to regularly
come to the island,

unnoticed, and kill
thousands of seals,

that seems very unlikely.

The second thing to ask is, why?

What would be the point
of killing these seals

and not taking their
meat or their skin?

No, they were probably
not killed by humans.

[narrator] Some believe these
seals were attacked

by natural predators.

That would be a reasonable
theory in some locations,

but what's on this
island to hurt them?

There's nothing except for
some birds and horses,

lots and lots of them.

If you fly over the island,
you'll see something truly wild.

More than 500 horses
running free.

It's just breathtaking.

[narrator] It was once thought
the horses were from

the many shipwrecks
around the island.

But they were likely
placed here for breeding

after being taken from
the French settlers

in the mid-1700s.

Regardless of how the
horses ended up here,

could a horse be a predator?

They're herbivores.

There's no way they did it.

So what did?

- So if it's not a
natural phenomenon

or the handiwork of humankind,
could it be something

in the middle,
like a boat or

specifically a propeller?

Generally, a ship's
propeller spins

and has a smooth edge that
would likely leave the seal

with a simple cut
before pushing it away.

It would need to be held
in place for a spiral cut.

Beyond those mechanics,
if you look at the

wounds from propellers on
animals like manatees,

they look nothing like that.

So this is likely not
due to propellers.

[narrator] Another
clue surfaces.

As the amount of bodies
rises, a small number of

seals are found with
crescent-shaped bite marks.

The North Atlantic is
home to great white sharks.

So maybe they are making
a meal of the seals.

Although there are lots
of great white sharks

in this region in
the warmer months,

the dead seals were
generally appearing

in January and February,
when the great whites

had already sailed
off to warmer waters.

So it's unlikely that
great white sharks

are the mass murderers here.

So what other shark species
might be responsible?

Black dogfish?

Too small, and the seals would
have made short work of them.

Orca? The tooth pattern
just doesn't fit.

The Bluntnose Sixgill shark,

the Blue Shark, and
the Tiger Shark

have only been found in
this area as juveniles,

and juveniles would be
too small to inflict

that kind of damage
on an adult seal.

[Anthony Cantor] Even though
some have dismissed the idea

that these wounds are the
work of marine predators,

there is one more candidate,
the Greenland shark.

[narrator] The Greenland
shark can reach up

to a staggering 23 feet long
and weigh over 2,000 pounds.

They're not just huge. They
have incredible longevity.

Some are 500 years old.

Think about it, that's twice
as old as the United States.

[James Ellis] While their
sluggish nature doesn't make

them the most likely candidates,
there's still some damning

evidence against them,
specifically their teeth.

The upper and lower teeth
of the Greenland shark

are very different.

The upper teeth are pointed
and sharp for clamping.

The lower are more blade-like.

[Anthony Cantor] And the
corkscrew tearing might be the

result of the seal's natural
impulse to escape by twisting,

a reflex which tragically
compounds the damage.

[narrator] But as experts
settle on their verdict,

similar corpses begin appearing
on the other side of the ocean,

on the coasts of England,
Scotland, and Ireland,

and what they find calls
the Greenland shark theory

into question.

And a bunch of the
seal carcasses in the UK

are found in July, when the
temperatures are way warmer

than the Greenland
sharks prefer.

The propeller theory had
been initially discarded

because it seemed propellers
would just totally gash

the seal rather than produce
the corkscrew pattern.

But what if the culprit was a
specific kind of propeller?

[narrator] Ducted
propellers are propellers

encased in short tubes
that could possibly

keep the seal in place,
allowing for the

corkscrew tearing pattern.

It's the kind of propeller
often seen in tugboats

that service oil rigs
or offshore wind farms.

When UK researchers
cross-referenced

the discovery dates of the
corkscrew-injured seals

with local shipping
records, they discover that

there were vessels with
ducted propellers nearby.

[narrator] To further test their
theory, researchers make small

wax models of seals
and put them into

model duct propellers.

The result, the same
corkscrew injuries

that were found on the seals
in the UK and on Sable Island.

Pretty convincing stuff,
but many of the seals

found dead on Sable
Island were still warm.

So it was most likely they
were killed close to shore,

not by an invisible
or distant boat.

So with the propeller dismissed,

the Greenland sharks kind
of are leading suspect.

But before we throw
the book at them,

let's just explore
one more possibility.

What if, plot twist, the killers
are the seals themselves?

Some people call
seals 'sea doggos'

due to their whiskers
and general cuteness,

but I wouldn't be quick to
cuddle one anytime soon.

Look at their mouths.

They have the fangs and teeth
of a dangerous predator.

[narrator] The seal's predatory
power is very clear

when a shocking photo bomb
blows the case wide open.

A marine biologist
is documenting a

seal breeding colony on
the Isle of May in the UK

when an adult male seal
appears in the background.

He attacks a seal pup,
his claws causing that

distinctive corkscrew cut.

He then basically pushes
his jaw into the wound

and manages to swallow some of
the pup's blubber and skin.

This is not a one-time thing.

Once the video is seen,
the seal is tracked

and he's seen doing
it again and again.

He's not the only one.

This is not normal
behavior for seals

and it's unclear
why it's happening,

but whatever the
reason, British experts

are now confident that
these bizarre seal deaths

are the result of cannibalism.

[narrator] While the case
of these killings is

closed for most,
others are unconvinced.

For them, the murder mystery of
Sable Island remains unsolved.