All language subtitles for Mysterious Islands 2024 S01E07 1080p WEB h264-EDITH_track3_[eng]

It looks like there's
been a massacre.

- Whatever is causing these
red waves and sands

is not something accidental.

[narrator] Deep in the
Pacific, on the island of

St. Helena, the
discovery of human

remains may be connected
to a dark period

of human history.

- More than a hundred
bodies in densely packed

unmarked graves.

- It's pretty evident
that these people

were subjected to severe
cruelty, but why?

[narrator] The discovery of a
strange mountaintop site in

Indonesia has caught the
attention of experts.

- Could this be some kind
of megalithic monument?

- It could have the potential
to rewrite human history

as we know it.

♪ ♪

[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?

♪ ♪

[thunder rumbling]

[narrator] Nestled in the Strait
of Hormuz, at the crux of the

Persian Gulf and Gulf of Oman,
and just five miles off

Iran's southern coast,
lies the island of Hormuz,

a curious, well-kept secret.

There's only one small town
here with a population of

approximately 6,500 people.

But when you consider
the topography,

you can begin to understand why.

There isn't a lot of arable
land here for growing crops,

just barren hills, and this
is largely due to the fact

that the island's
makeup is very unique.

It's actually a salt dome,
a geological feature

formed by the upward movement
of ancient underground

salt deposits within
the Earth's crust.

[narrator] Salt domes are
created in basins of the

Earth's crust, where thick salt
deposits from the evaporation

of ancient seas have
been buried beneath

layers of other sediments
over long periods of time.

Because salt has a lower density

compared to the surrounding
layers of sediment,

it has this natural tendency
to go up towards the surface,

which results in
everything from salt flats

to salt waterfalls, or even
dome-like islands like this one.

Salt domes have been
discovered all over the world

and on nearly every continent.

They can occur on land
or on the seafloor,

or, like in the case of Hormuz,
as domes that push their

way above sea level.

But that's not even the
most interesting thing

about this place.

[narrator] On the remote
southeastern part of the island

is Turtle Beach, a protected
area for hawksbill turtles,

where something totally
shocking is observed.

It looks like there's
been a massacre.

The edges of the
sea and the waves

washing up on the
shore are blood red.

Were the turtles attacked?

Okay, adult hawksbill
turtles and green turtles

obviously have these big
shells that can protect

them against attack.

They do get sometimes bitten
by sharks or crocodiles

or even octopus that
give them a good fight.

But let's think about this.

There are not really that
many of these turtles,

enough that even if all of
them were all massacred

at the same time somehow,
which would be very weird,

it wouldn't be enough to
change the color of the water.

[Amma Wakefield] In fact, there
are no remains of any kind,

not turtle, not shark or fish.

So what could be
causing this red sea?

Could it be a red tide?

[narrator] Red tides, better
known as harmful algae blooms

or HABs, occur when colonies of
plant-like organisms

that live in water
grow out of control,

resulting in toxic or harmful
environmental outcomes.

These harmful blooms can be seen
in many places across the globe.

One of the best known examples
of harmful algae blooms

occurs along Florida's
Gulf Coast most summers,

when the water turns
crimson with algae.

These blooms are on the
rise due to warming ocean

surface temperatures.

Low salinity, high nutrient
content in the water,

and calm seas that
don't break up blooms,

not to mention the number
of increased sunny days,

all add up to the increased
propagation of the algae.

Algal blooms are a
natural phenomenon.

They're part of a functional
marine ecosystem.

But when the nutrients
get too concentrated

or when temperatures
get too high,

those blooms can
get really intense,

and that can drain
oxygen levels.

Or sometimes the organisms
that make up those blooms

can secrete toxins
into the water,

which can then kill everything
from small fish to big sharks.

[Anthea Nardi] But there are no
dead fish or any other marine

life here on the
beaches in Hormuz.

And an algae bloom that
would make the water red

would also be cloudy with
the presence of algae.

But this water is eerily clear.

Red, but clear.

And if it were the
result of algae,

there would most likely
be dead or scummy algae

pushed up on the shore.

But the beaches here don't
have any slimy residue.

However, they are stained red.

So if it's not an algae
bloom, what is it?

Something else biological
might be at play.

[narrator] In 1819,
Bartolomeo Bizio, an Italian
pharmacist in Venice,

examined reddish-yellow stains
that would appear on polenta,

a cornmeal staple in Italy when
the food was left in states

of high temperature
and moisture.

What he discovered
was a new bacteria

called Serratia marcescens.

Serratia bacteria
produce a red pigment

called prodigiosin.

But that pigment's also
produced by a lot of other

bacterial species,
not just the bacteria

found in polenta.

And while it's been
harnessed to color things

like milk or carbonated
drinks, to date, it hasn't

really been used to
turn huge swaths

of anything red,
let alone an entire

area of a seashore.

But you know what has?

Industrial waste.

[narrator] In 2011, the Jian
River that runs through the city

of Luoyang, Northern
China, turned bloody red.

Officials there tracked
the source of the color

to an illegal factory
that was dumping red dye

in the river via the
city's storm water pipes.

So could Hormuz Island's
so-called blood

just be red dye?

There are no factories
like that here.

And even if there were,
they would have to

be dumping the dye into
the water constantly

to maintain that blood-red color
everybody's seeing at the beach.

Also, in Luoyang, China, and
other locations affected

by industrial chemical
contamination,

that red effect only
lasts for a few days.

These are lasting a
lot longer than that.

Whatever is causing
these red waves in sands

is not something accidental.

These stains have
been here on Hormuz

for a long, long time.

[narrator] Hormuz is
connected to the geological

creation of the region.

When the Arabian and
Eurasian tectonic plates

began to collide,
forming what we now know

as the Persian Gulf region.

That collision created
folding layers

that became mountains
and sedimentary basins

that, over millions of years,
contributed to the complex

mineral accumulation
of the area.

The rising dome
that forms Hormuz

is not just made of salt,
but layers of clay,

carbonates, shale,
and volcanic rock.

Some of these rock layers
become vividly colored

as they move towards the
surface through their

interaction with water, minerals
from other rock layers,

and the air.

It's thanks to this
natural phenomenon

that Hormuz earned its
nickname Rainbow Island.

From the water to the
beaches, the rocky shores,

the salt caves, the
mountains, the whole island

looks like this
brightly-hued land

of spectacular color.

[Anthea Nardi] And
unsurprisingly, one of the most

vibrant, visible
colors here is red.

Could the blood-red
color be the result of

mineral oxidation?

[Anthony Cantor] Locals
call this red soil gelak,

and it can be found along many
of Hormuz's colorful shores.

[narrator] Gelak is largely
composed of hematite,

a heavy oxide mineral
that is 70% ferric

oxide, or iron, which
does oxidize over time

to form a red or
rust-like appearance.

[Amma Wakefield] The island is
positively covered in hematite.

The root of that word is hema,
which is Greek for blood.

The waves in the beach
that initially sparked

notions of a turtle massacre
have an extraordinarily high

concentration of hematite
in the sand and rock

that makes up the shore.

When stirred by the
sea, the water takes on

that tinge of red due
to minute particles

being disturbed.

And there's no reason to think
this is gonna fade anytime soon.

Erosion should keep that
blood-red hematite,

or gelak, as it's
called, in the water,

and the salt water
and the sunlight

are just gonna continue to
intensify those colors.

Gelak holds a special
place in the hearts of the

people of Hormuz.

Once believed to be
a gift from God,

it's prized as a spice that
gives the local cuisine

a distinctive red hue.

[Amma Wakefield] When
speaking about a place,

people will sometimes say
there's something about

it that lives in the
blood of its people.

Well, here on the wondrous
island of Hormuz,

because of the red,
iron-rich soil,

it's not just a cliche.

♪ ♪

[narrator] The island of St.
Helena is a British overseas

territory located in the middle
of the Atlantic Ocean,

about 1,200 miles west
of Angola, Africa.

♪ ♪

St. Helena isn't
particularly big,

only about 47 square miles,
which is a little over

twice the size of Manhattan.

It was formed
millions of years ago

by now-extinct volcanoes
that created this

mountainous landscape.

The history of the
island and its people

is a fascinating one.

This is where the
British exiled Napoleon

after he was finally
defeated in 1815.

He'd been exiled once before,
but that was to an island

in the Mediterranean,
from which he escaped

and returned to power in
France less than a year later.

After finally defeating him
at the Battle of Waterloo,

the British sent him way out
here to live out his days.

[narrator] In 2006, in
an area of St. Helena

called Rupert's Valley, a group
of workers are constructing

the island's first
airport when they unearth

something shocking.

They find two skeletons
that appear to have

been laid to rest here.

What's strange is that
there's no headstone

to identify them or indicate
when they were buried.

So who are they?

♪ ♪

[narrator] A team of
archaeologists is set out

to learn more about the burials,
and it isn't long before

they begin finding
more human remains

throughout the area.

More than 100 bodies are
found in densely packed,

unmarked graves, with
some containing as

many as six skeletons.

After ten weeks of
painstaking work

excavating an 18,000-square-foot
plot of land,

a total of 325 skeletons
are discovered

in 178 graves.

♪ ♪

- At first glance, it's
evident that most of the

remains are male.

The pelvises have thicker
bones and a narrower shape

than female pelvises.

Also, a lot of the
skeletons aren't that big,

indicating that
they were children

between 8 and 12 years old.

♪ ♪

[narrator] Further osteological
analysis indicates

that many of the individuals
were suffering from

a specific disease at
the time of death.

The bones show
signs of scurvy,

a disease caused by
a lack of nutrition,

specifically a
deficiency in vitamin C.

Some of the symptoms
include bleeding gums,

loose teeth, fatigue, and
pain in the arms and legs.

It can be fatal if not treated.

[Sarah Klassen] In the past,
scurvy was very common among

sailors because they didn't
always have access

to fresh fruit and vegetables.

Considering how
remote St. Helena is,

people might have
contracted scurvy

on the voyage to the island.

If so, it's likely that
many of these individuals

died as a result of the disease.

♪ ♪

[narrator] While scurvy and
diseases related to malnutrition

are present, a striking
number of the remains

also show signs of
having been subjected

to extreme acts of violence.

[Alison Leonard] It's pretty
evident that these people

were subjected to
severe cruelty, but why?

[narrator] The archaeologists
sent 63 sets of remains

off for DNA testing
to learn more about

these people's origins.

Scientists are able
to obtain results

for 20 of the 63 individuals.

Their genetic makeup indicates
that they were most closely

related to the people
in what is now Gabon

and northern Angola,
areas known historically

as the location where
individuals were

forced into slavery.

♪ ♪

[narrator] Over the course of
400 years, more than 15 million

people were taken from Africa
and sold into slavery

by slave traders.

For many years, the
most powerful actor

within this trade
was Great Britain.

[Anthony Cantor] Throughout
the duration of the

transatlantic slave trade, it's
estimated that the British alone

forced 3.2 million people into
the holds of slave ships.

We can also say that 10% to
20% of these enslaved people

died en route to the Americas
due to horrendous treatment

and horrible conditions.

[James Ellis] By the end of the
17th century, almost half of

St. Helena's population was
made up of enslaved people.

As Britain's empire and
territorial holdings grew,

they faced an increasing
demand for labor,

and they met that demand
by enslaving African men,

women, and children,
and trafficking

most of these enslaved
people to the Americas.

♪ ♪

[Alison Leonard] Over the
years, the slave trade

had created a large
diaspora of Africans

from vastly different
parts of the continent,

and they were sent
to various colonies,

including St. Helena.

♪ ♪

[narrator] Back at the
site in Rupert's Valley,

the archaeologists find
coins that have been laid

over the eye sockets
of newborn children

in three separate graves.

[James Ellis] The coins are
mostly made from silver,

and because they're so
old, the faces are worn,

and they look like little
more than blank tokens,

but they're able to
use X-ray analysis

to reveal their
original designs.

[Sarah Klassen] It's remarkable.

One shows a portrait
of Queen Victoria

and bears the inscription

"Victoria D.G.
Britanniar Regina F.D."

with an inscribed date of 1843.

All the other coins are
found to be British

and minted between
1838 and 1870,

after they outlawed slavery
throughout the empire.

[narrator] Even after Britain
banned the slave trade,

slavers tried to continue
bringing enslaved people

from Africa to slaveholding
societies in the New World.

The transatlantic slave trade
didn't fully end until 1873.

In 1808, Britain set
up a special fleet

called the West Africa
Squadron to enforce the ban

on the slave trade,
even though banning

the slave trade
would have negative

consequences for interests
in the empire that

depended on slavery.

[narrator] Owing to its
strategic location,

St. Helena was chosen
as a base for the

West Africa Squadron in 1840.

From here, the British fleet
patrolled the Atlantic,

intercepting ships
carrying enslaved people

to the Americas.

The enslaved people were
liberated by the British

and taken back to St. Helena,
where they were fed and housed

in what were essentially
refugee camps,

one of which was in
Rupert's Valley.

Many of those rescued
were so mistreated

that they couldn't
regain their health,

and approximately one-third
of them died after arriving.

- The people who survived
were technically free,

but weren't repatriated
to their communities.

Instead, many were sent to
the British West Indies

or to Cape Town, where
they would live and work.

♪ ♪

It's difficult to come to terms
with the cruelty of it all.

They were first taken
from their communities

to be sold as enslaved
people, then saved and

granted their freedom, only
to eventually be taken

to a completely
foreign place to work,

often as indentured laborers.

♪ ♪

[narrator] Between 1840 and
1867, roughly 27,000 people

rescued from slave ships
were brought to St. Helena.

They became known as
the Liberated Africans,

and today, many St. Helenians
can trace their ancestry

directly to them.

♪ ♪

Apart from this group, it's
thought that over 8,000

Liberated Africans lie
buried in Rupert's Valley,

all victims of the
transatlantic slave trade.

They were part of the
largest forced migration

in human history, one
whose violence, trauma,

and horror is still
deeply felt today.

♪ ♪

[narrator] The 325 Liberated
Africans exhumed in

Rupert's Valley have since
been given a proper burial

and a memorial that
will be erected

to honor their legacy.

The small island of St. Helena
played an important role

in bringing to an end
this centuries-old

crime against humanity.

♪ ♪

Framed by the Java
Sea to the north and

the Indian Ocean to the south,

Java is Indonesia's
political, cultural,

and economic heart and the
world's most populous island.

♪ ♪

[Alison Leonard] Java is the
13th largest island on Earth

and one of its most
densely populated places.

It contains over
half of Indonesia's

almost 280 million residents,
despite making up only

about 7% of its land area.

But even though Java
is highly populated,

it still has areas
of breathtaking,

unspoiled wilderness.

Running lengthwise through
the middle of the island

is a mountain range dotted
with volcanic peaks.

In fact, there are an impressive
112 volcanoes on the island,

but only 35 of them are
active, so eruptions are rare.

[narrator] Near the village of
Karyamukti in the province of

West Java, while exploring
the area, one may come across

an unusual sight.

Cut into the forest
are what looks like

a series of old stone steps
going up a rather steep slope.

It's not an easy climb.

There are a total of 370
steps rising around 360 feet

at a 45-degree incline.

♪ ♪

[narrator] If you're
able to brave the climb,

when you finally reach the top,
the scenery is extraordinary.

It's a grassy terrace with
hundreds of long, narrow

stones of varying sizes,
some of which are strewn

about haphazardly,
while others are

standing upright and
appear to form patterns.

It's really strange.

What is this place?

The terrace is not
quite a perfect square.

It's more like a trapezoid.

The front is about
130 feet wide,

but it tapers to around
118 feet at the back,

while both sides are pretty
much the same length,

just over 92 feet.

[Anthony Cantor] The left-hand
side is littered with stones,

but on the right-hand side,
the stones are arranged

into a rectangle with
two taller stones at

either side of the entrance,
almost like gates.

Could this be some kind
of megalithic monument?

[narrator] Standing stone
monuments are most common

in northwestern Europe,
particularly in Great Britain.

On Scotland's Isle of Lewis,
the Calanais Standing Stones

have been watching
over the rugged

Highland landscape for
roughly 5,000 years,

predating England's
famous Stonehenge.

The complex is made
up of over 50 stones

in the shape of a cross,
with a circle of stones

between 8 and 13 feet
tall, forming the

heart of the monument.

In the middle of the
arrangement is the tallest

stone at the site,
which towers over the

others at 16 feet tall.

Incredibly, the layout of
the stones in two locations

is so precise that
they can be used

to measure the moon's
most northerly position

on the horizon, an
event that only happens

roughly every 18 1/2 years.

Maybe the Terra site on
Java has some kind of

celestial connection.

- I suppose it's possible,
but there are definitely

some key differences.

First of all, there's the shape.

Most known standing stone sites
are circular, not rectangular.

The circular shape of
sites such as Stonehenge

could be aligned with
astronomical phenomena

like solstices, and
may have served

ceremonial or
calendar functions.

The scale is also different.

Those stones are
generally much bigger

and spread out over a large area
like Stonehenge or Callanish.

The stones on Java are
densely packed together

and smaller than what
is found elsewhere,

so it's unlikely it had
an astronomical purpose.

[narrator] Continuing to
explore the area,

you'll come across a short
incline beyond the terrace

with another set of
ancient stone steps.

At the top of the steps,
there's another terrace.

This one is smaller
than the first.

The front measures
roughly 72 feet across

and narrows to about
60 feet at the back,

and it's around 80 feet
long, a similar trapezoidal

shape to the first terrace.

On the second terrace, there
isn't a geometrical layout

like the rectangle formation
on the first terrace.

There are similar stones, but
they're lying on the ground

seemingly in no
discernible pattern.

[narrator] The perimeter is
supported by what looks

like a retaining wall.

The wall appears to be made
up of long, narrow stones,

the same kind that are
found on the terraces,

but these are stacked
horizontally,

giving support to
the flat areas.

Given the different levels,
along with the retaining wall

and the rectangular structure
on the first terrace,

it looks like whatever
this place is,

it was in some way
constructed by human hands.

But why?

[narrator] The site, known
as Gunung Padang,

consists of five
terraces in total,

each one rising successively
taller than the last,

climbing to a peak of over 650
feet above the forest floor.

Overall, the complex
covers an area

of roughly 30,000 square feet.

That's about half the
size of a football field,

making it the largest megalithic
site in Southeast Asia.

[Anthea Nardi] Most of the
stones found at the site

are pretty uniform
in size and shape,

seeming like they might
actually be hand-cut,

which supports the theory
that Gunung Padang

was constructed by humans.

But they're actually naturally
occurring volcanic rocks.

[narrator] The stones are the
result of a geological process

called columnar
jointing that occurs

when a thick body of cooling
magma, usually basalt,

contracts and cracks
into rock columns,

most commonly
hexagonal in shape.

Famous examples
of the phenomenon

are found at the Giant's
Causeway in Northern Ireland

and the Devil's
Postpile in California.

It's thought that the
stones at Gunung Padang

may have been sourced from a
volcanic quarry to the north

and then transported to the
site where they were used

to build the stairs and
any structures that

may have once existed on the
surface of the terraces.

But some people believe there's
a lot more to Gunung Padang

than what's on the surface.

One theory is that the hill is
not naturally occurring at all,

but rather built by humans.

This has led some to
believe that it's a

huge step pyramid-like
underground complex, similar

to other ancient sites.

[narrator] On China's lowest
plateau, archaeologists

unearthed the ruins of a
230-foot-high step pyramid

and the remains of a
4,300-year-old fortress city

known as Shimao.

The first pyramid the
Egyptians ever built,

the Step Pyramid of Djoser, was
built about 4,700 years ago

with six layers above ground
and a series of tunnels below.

[Anthony Cantor] If there is, in
fact, a pyramid underground

at Gunung Padang,
it would be quite

different in appearance.

Egyptian pyramids are, for
the most part, symmetrical,

whereas the Gunung
Padang complex

is long and narrow and
irregularly shaped.

[narrator] In 2011, a geologist
named Danny Hillman Natawidjaja

performed another series of
tests, namely core drilling,

a process that involves
drilling under the ground

and removing soil
to be analyzed.

The results ignite a
firestorm of controversy

among the scientific community.

Based on carbon
dating of the samples,

Gunung Padang contains
several different layers

constructed during
different time periods.

The oldest potentially dating
back a shocking 28,000 years.

Unless there was some
kind of lost civilization

that existed over
20,000 years ago,

humans at that time were
simply not advanced enough

to build a huge pyramid complex.

So how could it be possible?

- Well, to be honest,
it probably isn't.

The dating is flawed.

Anything organic can
return a radiocarbon date,

but dateable raw material is
not evidence of human culture.

- Really, the most
plausible explanation

is that Gunung Padang is
part of an extinct volcano.

The voids that were theorized
to be rooms and tunnels

are probably magma chambers
or air pockets created by

subterranean collapses.

- The terraces and
retaining walls are most

likely the result of unique
volcanic and seismic activity

over the millennia.

So while there's no doubt
that ancient humans

did put their stamp on the
site, creating the rock

formations and staircases
probably around 2,500 years ago,

at this point, the
pyramid theory

is more science
fiction than science.

[narrator] Gunung
Padang translates to

"mountain of enlightenment,"

and today, the site
is a revered place

used for prayer and meditation.

For the time being,
whatever lies beneath

this hallowed ground
remains one of Java's

most enduring mysteries.

Just off the coast
of Antarctica,

in the Ross Sea,
sits Lamplugh Island,

a rugged ice-capped landmass
around 10 miles long

and 2 miles wide.

The island was observed
by famous explorer

Robert Falcon Scott
during the British

National Arctic Expedition
that took place

between 1901 and 1904.

Several years later, Ernest
Shackleton charted Lamplugh

as an island and named it after
a member of his expedition.

A little bit north of Lamplugh
is the Drygalski Ice Tunnel,

a 43-mile-long expanse
of ice that ranges from

9 to 15 miles wide and
extends out from the

coast into the Ross Sea.

[narrator] In 2016, a team of
American biologists

are conducting research
on Cape Irizar,

a rocky outcropping on
Lamplugh Island's north coast

when they come across
a strange sight.

Scattered across the shoreline
are several small mounds

made up of pebbles, all of
similar size and shape.

What are these things?

They could just be
natural rock formations.

I mean, this is Antarctica
after all, right?

So the ice is constantly
moving things around.

It's changing the landscape.

Maybe those mounds are just
the result of glacial movement

depositing the stones here.

[narrator] Rocks that have
been carried by glaciers

and then deposited elsewhere
are known as glacial erratics.

As a glacier or ice sheet
moves, it can erode bedrock,

and the resulting debris is
then picked up by the ice

and transported in the
direction of the flow.

When the ice retreats,
it leaves behind

a different type of
rock from the bedrock

where the erratic was deposited.

The largest known glacial
erratic in the world

is found in Alberta, Canada.

It's a massive quartzite
boulder about the size of a

three-story apartment
building and weighing roughly

16,500 metric pounds.

Glacial erratics can range
in size from large boulders

to smaller stones and
pebbles, like what was found

on Lamplugh Island.

[narrator] Upon closer
inspection, the team is able to

identify the mounds based on
previous excursions

around the Antarctic coasts.

These aren't from glaciers.

They're nests, and
specifically, they're the nests

of Adélie penguins.

These birds spend most of
their time out at sea,

but when it's spring,
they come to dry land

and painstakingly
collect pebbles,

hundreds of them, to
build these nests

where they can lay their eggs.

And they always pick
a spot on a slope

so that when the snow
melts, the water flows

away from the nest,
keeping the eggs safe.

Now, finding Adélie
penguin nests

in this part of Antarctica
is not that shocking.

The Ross Sea supports almost one
million breeding pairs a year,

but finding them on Lamplugh
Island is definitely strange.

[Alison Leonard] Both Scott and
Shackleton reported seeing

penguin populations along
the mainland coast,

but there were never any
sightings of them here.

And as of today, the
nearest penguin colony

to Lamplugh Island is
roughly 45 miles north

on Inexpressible Island,
on the other side of

the Drygalski Ice Tone.

So why are there nests here?

[narrator] Their scientific
curiosity peaked.

The team continues
to explore the area.

They noticed guano stains
on some of the rocks

around where the
nests were found,

suggesting recent
penguin activity.

But that can't be possible,
because Adélie penguins

can't access Cape Irizar
even if they wanted to.

Fast ice, which refers to
large, solid ice sheets

that are attached to
land, prevents their

entry onto beaches.

And there are daunting
cliffs along other

parts of the shoreline
as an added obstacle.

[narrator] Baffled by what they
found so far and looking for

answers, the team expands their
investigation of the area,

and it isn't long before
they're face-to-face

with a macabre sight.

- They find Adélie
penguin remains,

and not just one or two birds,
dozens of them in various

states of decomposition.

Now, some are mummified,
which presumably means

they've been here
for a long time,

but others look very fresh, as
though they died just recently.

[narrator] Mass penguin
die-offs are not unheard
of in Antarctica.

In 2016, a research
team discovered

the mummified remains of
hundreds of Adélie penguins

in thick layers of sediment
on East Antarctica's

Long Peninsula, most
of them just chicks.

Radiocarbon dating showed that
this wasn't a sudden die-off.

They died gradually over
the course of decades,

and this happened in
two different periods,

dating to about 750
and 200 years ago.

[Alison Leonard] It's believed
that their deaths were the

result of weather anomalies,
unusually wet periods of rain

and snow soaked the chicks,
and because they hadn't

yet developed the
waterproof feathers

that adult penguins have,
they died of hypothermia.

Could something similar have
happened on Lamplugh Island?

It's certainly possible,
given that in both scenarios

the majority of the
remains were chicks,

but many of the bodies on Long
Peninsula were found buried,

probably because flooding
washed the penguins
downhill with sediment.

But that's not what it
looks like on Lamplugh.

The remains here are all just
kind of scattered around

on the surface of the ground.

They're not buried at all.

[narrator] The team decides to
put their paleontology skills

to use and sets about excavating
penguin nests.

All of the sites are
very dry and dusty

and made up of ornithogenic
soil, or bird dirt.

Which is earth that is rich in
carbon, nitrogen, and phosphorus

because of the
presence of birds.

Polar ecosystems are
notoriously nutrient-poor,

but bird populations
help remedy this

by adding organic matter to
the soil in the form of guano,

feathers, eggshells,
and their remains.

The nests are quite
shallow and at a depth

of around 4 to 6 inches.

They're able to collect various
materials, including bones,

eggshell fragments, skin
samples, feathers, and guano,

containing the remains of
their prey, mostly fish bones.

[narrator] The organic material
is sent to a lab for analysis.

Some of these penguins
are over 5,000 years old,

and the so-called fresh
remains that were thought

to have died recently are
actually 800 years old.

The tests show that there
were 3 different periods

of the Adelie penguin
occupation on Cape Irizar,

beginning around 5,000
years ago and ending

roughly 685 years ago.

Their ultimate
disappearance coincides

with the Little Ice Age, a
period of global cooling

from around 1300 to 1850 CE,
when average temperatures

dropped by as much as
3.6 degrees Fahrenheit.

The question is, why do
they keep coming and going?

[Dan Riskin] It likely
has something to do
with the climate.

Periods of warmer weather would
have resulted in the

fast ice on the shoreline
melting in the early summer,

and that would have provided
water access to the

penguins in breeding season.

They could have just
swam right up and built

their nests on the coast.

But when the climate got
colder, the beaches were

no longer accessible.

There was still ice in the way,
so they had to abandon the Cape,

or maybe the penguins
just all died off there.

It could have also had
something to do with

changes in the thickness
and size of the

Drygalski Ice Tongue over the
years, impacting the ocean

conditions off Cape Irizar.

And significant calving
events, which is when

ice chunks break off
from the edge of a

glacier, could have
caused large ice masses

to choke off the penguins'
access to the shores.

What I don't understand,
though, is that if

there's all this evidence
of penguin populations

living on Lamplugh Island
over thousands of years,

how come no one
noticed it before?

[narrator] Consulting with
historic satellite images,

the team quickly realizes that
the most obvious answer

is usually the correct one.

Up until a few years
ago, the Cape was

covered in snow and ice.

Because of climate
change, since the 1980s,

temperatures in the Ross
Sea have increased by

2.7 to 3.6 degrees Fahrenheit.

And as a result, Cape Irizar
and all of Lamplugh Island

have been slowly emerging
from a deep freeze.

[Dan Riskin] So the fresh guano
stains and penguin carcasses

that don't look very
old are very old.

They were perfectly preserved,
spending hundreds of years

buried under ice and snow,
only to be exposed by

the warming of the planet.

So how does this affect the
future of Adelie penguins

in this part of the world?

[narrator] In an ironic
twist, the receding ice
on Lamplugh Island

may actually be beneficial to
some of the penguin populations

of southern Antarctica.

Because Adelie penguins breed
on land, and more and more

shorelines are being exposed,
it gives them greater territory

on which to build their
nests and hatch their young.

So in some areas, penguin
populations are growing

rather than shrinking.

Right now, the fast ice
around Cape Irizar melts

too late in the season to
make it a feasible place

for the Adelies to breed.

But that could change
in the future as

climate change worsens,
and it could become home

to a robust penguin
population once again.

But these are only
regional short-term gains.

The longer-term outlook
is actually quite bleak.

So while it's wonderful for
some penguin populations,

in terms of our global future,
it's actually pretty depressing.

Some reports predict that 30%
of the Adelie population could

be gone by the year 2060,
and as much as 60% of the

population will disappear
by the end of the century.

The numbers are already
declining around the

West Antarctic Peninsula,
one of the fastest-warming

places on Earth.

And that makes it very hard
to predict exactly what

the long-term outlook is
for these adorable birds.

[narrator] As the ancient
Antarctic climate changed,

so too did the nesting habits
of the Adelie penguins.

And now, hundreds of years
later, history appears

to be repeating itself.

The discovery of the long-lost
colonies on Lamplugh Island

is a perfect illustration
of the tenuous balance

between animal habitats and
environmental conditions.