Expedition: Saving Our Seas (2026) Movie Script
[Narrator] The ocean covers
more than 70% of our planet
and is packed full of life.
[Explorer 1]
The health of the planet
depends on a healthy ocean.
[Explorer 2]
It's absolutely essential.
[Narrator]
But as the climate heats up,
our seas are under pressure
like never before.
[Explorer 3]
We're seeing an ecosystem
that's changing in real time.
[Explorer 1] It could have
devastating consequences.
[Narrator] Now a team
of Explorers,
part of the National Geographic
and Rolex
Perpetual Planet
Ocean Expeditions,
is launching a series
of groundbreaking missions...
[Explorer 4] Just imagine
what we're gonna find!
[Narrator]
...to better understand
and protect our seas.
Traveling from pole to pole
across all five ocean basins...
[Diver] Go!
[Narrator] ...from seashore
to seafloor.
[Explorer 4] We've seen more
of the surface of Mars
than we have
of our own deep sea.
[Narrator] In a new era
of ocean exploration,
they'll team up
with coastal communities,
combining timeless wisdom
with cutting edge technology.
[Explorer 2] We're really
pushing the boundaries
of what we think we can do.
[Explorer 4] It works.
[Explorer 2]
It's not the time to give up!
[Narrator] Working together,
they'll help us to reimagine
our world, not divided by land,
but united as one ocean.
The Southern Ocean,
the most remote on the planet.
Spanning 8 million
square miles,
these icy blue waters are
a vital feeding ground
for ocean giants.
Because it's so isolated,
much of what happens here
remains a mystery
for oceanographers.
[Andrew Thurber]
One of the things I love
about the Southern Ocean
is it's full of surprises.
Everything is unique there.
[Narrator] This team of
National Geographic Explorers
is on a pioneering voyage
in collaboration
with the Schmidt
Ocean Institute,
aboard its research vessel,
the Falkor (too).
[Allison Fong] The Southern
Ocean Expedition is unique
because we don't typically
put as many diverse themes
of science on one ship.
[Narrator] The team believes
that the key to understanding
the abundance of life
on the surface
is to discover what's
going on deep below.
To do this, they're using
a state-of-the-art
remotely operated vehicle,
or ROV, named SuBastian.
The plan is to deploy the ROV
down to 13,000 feet,
nearly two and a half miles,
the deepest ever survey of this
part of the Southern Ocean.
[Andrew] We want to peer into
those icy, deep, dark depths
to uncover things that nobody
has ever seen before.
[Narrator] One of the things
oceanographer
Dr. Andrew Thurber wants to
find is a hydrothermal vent.
[Andrew] Hydrothermal vent,
where superheated fluid
is being pumped
out of the seafloor,
and it creates these habitats
that fuel many
different organisms.
[Kim Bernard] We're about
to deploy the ROV
for the very first time.
I can't wait. I can't wait.
I'm just really excited to see
what it looks like down there.
[Narrator] The Explorers crowd
the control room
to watch as the ROV SuBastian
descends into the alien-like
world beneath.
[Kim] As the ROV
is descending
through the water column, these
things are sort of shooting past
so fast that it's a little bit
like the start to Star Wars.
It looks like you're in the
middle of space, just flying.
[Narrator] At 650 feet...
[Andrew] Oh!
[Narrator] All natural light
disappears...
[Crewmember] Wow.
[Narrator] ...opening up
a rarely seen world.
[Kim] There is so much life
within the water column.
It's alive with beings.
[chatter]
[Narrator] Then the team spots
something truly extraordinary.
[Andrew]
Wow, it's a huge squid.
Wow!
It's about a meter and a half.
It's so rare it doesn't
have a common name.
It's just an amazing experience
to be able to interact
with this organism
that had never been seen
before while it was alive.
[Narrator] After four hours,
the ROV SuBastian touches down
on the seafloor.
The deepest ever glimpse
into this area
of the Southern Ocean.
Now the team begin their search
for the mineral rich,
super hot water
of a hydrothermal vent
by looking for signs of life.
[Andrew] The entire deep sea has
no energy from the sun.
It's a food desert.
Hydrothermal vents provide
energy and nutrients;
this wealth of food.
And so it creates these oases
of strange biological oddities.
Let me see.
[Narrator] One of those oddities
is a dumbo octopus.
[Crewmember] Wow.
[Narrator] The deepest living
octopus known to science,
named for its large
ear-like fins.
Look at me, I can't wipe
this smile off my face.
[Narrator] There are plenty
of unique creatures.
But no sign of a vent.
[Andrew]
It's 7:10 in the morning,
we've been up all night.
Had an amazing evening.
One of the most amazing seafloor
environments on the planet.
[Narrator] Then, looming
out of the abyss...
...a towering chimney,
30 feet tall appears.
[Andrew] Found some little
shimmering water.
[Leigh Torres] The heat is just
coming off everywhere.
[Andrew]
It's a hydrothermal vent.
Just so everybody's
equally excited,
this is the most southerly
deep sea vent
known on the planet.
First ROV dive.
The first real view
of this habitat ever.
[Explorer 1] 234, 243...
246 degrees Celsius.
[Explorer 2] Amazing.
[Explorer 1] That is hot.
[Narrator] Despite
temperatures of nearly
500 degrees Fahrenheit,
there's all sorts of life
around the vent,
including tiny animals
that Dr. Kim Bernard
loves more than anything.
[Kim] Oh, look, there! Guys!
The krill.
[Narrator] Krill.
[Kim] We got krill!
[Explorer] Yay! Krill!
[Kim] This is so exciting!
So they look a little bit
like shrimp, but they're not.
They're pretty cute.
They're just like looking at you
with their big eyes,
swimming around,
sometimes doing backflips.
The krill are coming in.
[chuckles]
To me, Antarctic krill
are the superheroes
of the Southern Ocean.
They are a vital part
of that ecosystem.
Penguins, seals,
whales, seabirds
all feed on Antarctic krill.
[Narrator] Krill have been
studied at the surface,
but this is the first time
they have ever been found
at a hydrothermal vent.
[Kim] I was not expecting
to see krill.
Oh, my god,
they keep showing up!
[Narrator] Incredibly, Kim
discovers most of the krill
at the vent are carrying eggs
and are ready to spawn.
This hidden deep sea nursery
could be a vital lifeline,
sustaining marine life across
the entire Southern Ocean.
While the ROV team continue
to explore in the depths,
Dr. Allison Fong is topside,
leading a dangerous mission...
[Allison] Safety first.
[Narrator] ...to study
the sea ice that in winter
can cover nearly half
of the Southern Ocean.
As the climate warms, our
oceans absorb the excess heat.
With Antarctic waters
soaking up 75% of it.
But in recent years,
the impact is starting to show
as the sea ice melts
at an alarming rate.
[Allison] In light of the fact
that we know we're losing
sea ice, what happens?
That was the main goal
in the Southern Ocean
expedition for me.
[Narrator] Allison wants to take
a sample of the sea ice.
Locked in the ice are
tiny creatures called microbes
that play a surprisingly
important role
in all of our lives.
[Allison] Microbes are
responsible for creating
50% of the oxygen that
we breathe on this planet.
[Narrator] That's more than
all the world's
rain forests combined.
[Allison] Every other breath
that you and I take
is an oxygen molecule that
was produced by a microbe
that lives in the ocean.
[Narrator] Allison wants to find
out how the sea ice microbes
are coping in
our changing climate.
To take a sample, she needs
to get onto an ice floe,
but not just any ice floe.
[Allison] No, that's too tall.
[Narrator] It has to be
just right.
[Allison] Ooh, it's thick?
It's thick, and it's missing
a lot of the little...
[Narrator] Thin enough
so they can take a sample
through to the sea below.
[Allison] Just ahead,
there's some flat ice.
It looks like a flat
piece of paper.
You're gonna have
to approach real slow.
[Crewmember] Yeah.
[Narrator] But thick enough to
stop them from falling through.
[Allison] Perfect.
[Narrator] This is the most
precarious part
of their mission.
Checking the ice
will hold their weight.
[Allison] When you see large
blocks of ice floating around
with 4,000 meters
of ocean below it,
and I'm supposed to stand
on that one meter of ice
and put holes in it
to collect samples?
It's crazy.
Alright. Be very careful
of the edge.
But it's also really special,
because it's like walking
on water, right?
So you should walk where I walk.
[Narrator] Most of the sea ice
microbes live on the underside
of the ice
in the bottom five inches.
To reach them, the team use
a corkscrew-like core,
designed to drill through
the ice and lift out a sample.
Some inquisitive neighbors,
Adelie penguins,
come to check out
the commotion.
[Allison] Oh, no.
What's happening?
The nature of
working on sea ice
is that it is predictably
unpredictable.
[Narrator] Today, that
unpredictability isn't working
in their favor,
making this usually
simple task harder.
[Allison] It's a lot of water.
We really didn't expect
the whole ice column
to be completely
inundated with sea water.
It's like wet concrete.
We're just not able to get
the corer through that,
because it's just too heavy.
So we might have to call it.
[Narrator] The team has one
last chance to get their core.
[Crewmember] It went through.
[Allison] It went through.
Oh, my god, I'm so relieved.
You can see
the sea ice algae in here.
Do you see the little specks?
[Crewmember]
I do see the specks.
[Allison]
That's the sea ice algae!
Good job.
[Narrator] When microbes gather
in huge numbers
at the bottom of the ice,
they can form colorful
algal blooms.
[Allison] You can really stick
your nose in there,
you can really smell it.
Yes. That's algae, yeah.
[Crewmember] I can smell it
from here. Yes. That's algae.
[Narrator] By collecting these
microbes for further analysis,
Allison hopes
to better understand
how these lungs of the sea are
coping in our warming world.
[Allison] Almost all of
the animals we see on our planet
exist because microbes
produce oxygen.
So if you love animals,
you need to love microbes,
and more than that,
you need to love sea ice.
Woo, what a day!
[Crewmember] Thank you.
[Allison] Thank you, ice floe!
[Narrator] The Southern Ocean
is connected
to all the other ocean basins
by deep water currents known as
the Great Ocean Conveyor Belt.
From Antarctica
it flows eastward
before peeling off
into the Pacific.
Covering 60 million
square miles,
the Pacific is the largest
of all our oceans.
Bigger than all the world's
land combined.
And it's home to the largest
animal that's ever lived.
The blue whale,
up to 100 feet long
and weighing up to 200 tons.
Most blue whales migrate
across oceans to find food.
But off the west coast
of New Zealand,
the South Taranaki Bight is
home to a special population
that call these waters
home year round.
Now, a team of Explorers,
including krill expert
Kim Bernard
from the Southern Ocean
Expedition
and blue whale expert
Dr. Leigh Torres...
[Leigh Torres] The survey team
is scanning the horizon,
looking for blows.
[Narrator] ...are heading out
to discover how rapid changes
in ocean temperature are
impacting these marine giants.
The expedition is a partnership
with the local Maori community.
For Abraham Fletcher, blue
whales hold deep significance.
[Abraham Fletcher]
In our culture they're seen
as these, these guidance
or symbols of wisdom.
It's all woven into
who we are as Maoris.
Our ancestors navigated
using the tides, the birds,
even using the whales
to find safe passage,
and that's my connection here.
[Narrator] The team have been
monitoring this population
for several years,
recording whale numbers
as well as the density
of their prey, krill.
[Kim] So the krill species here
is the only thing
that these blue whales eat.
Blue whales are
massive creatures,
and they're eating
these tiny krill,
which is insane
if you think about it.
[Narrator] The best way
to find the whales
is to find the krill, and that
means taking to the air.
[Kim] We recruited
an aerial survey team,
and that was
a real game changer.
[Narrator] The survey reveals
huge swarms of krill
at the surface.
[Leigh] Wow, look at the size
of that swarm.
[Kim] It's about 2,000
square meters.
[Leigh] That's amazing.
[Kim] It's huge.
[Leigh] Great to have
this eye in the sky.
[Kim] Yeah.
[Narrator] Now the crew knows
where to direct their search.
[Leigh] There, there,
there, there, there.
There it is. Woo! Finally.
[Narrator] From the boat it's
hard to see what's going on,
but from the air,
the team witness
something extraordinary.
Blue whale behavior
known as lunge feeding.
[Leigh] A third of their body is
their head and their mouth,
which is pretty huge.
They'll be going really fast,
and then they'll
open up their mouth
to engulf that
big patch of krill.
But that really
slows them way down.
It's like slamming
on the brakes.
[Narrator] With the krill
swarming at the surface,
the whales can scoop
up to half a million calories
in one mouthful.
With all that food, this year,
they appear to be doing well.
[Leigh] There's two whales
in front of us.
It's a mom and calf.
It's really exciting to see
moms and calves,
that, that means the ecosystem
is doing okay.
[Narrator] The South Taranaki
Bight is a hot spot
for blue whales, and thanks
to the aerial surveys,
the team can see why.
[Kim] In this area we get
what is called upwelling,
so the deeper waters
move up to the surface.
In that upwelling plume
of more nutrient-rich waters,
that's where we're seeing
the krill at the surface,
and the whales,
they're feeding on them.
[Narrator] These unique
conditions explain
why the whales stay here
year round.
[Leigh] This one is
just about to munch
on that big krill swarm there.
[Narrator] But it also makes
them vulnerable
to rapid changes
in ocean temperature.
[Kim] In warmer
ocean conditions,
the upwelling that brings
nutrients into the area
tends to shut off.
We tend to see fewer krill
and fewer whales.
[Narrator] The team's findings
will help inform
how best to protect
the planet's biggest creatures,
both in New Zealand
and across our one ocean.
[Kim] What we learn about
how marine heatwaves
affect the krill
and the blue whales
can then be transferred
to other marine systems
throughout the world's oceans.
That's the part
that gives me hope.
[Abraham] I think it's amazing,
this interface between
Western science,
but also weaving in, you know,
our Maori perspectives.
I think it can form
something very beautiful.
[squeaking]
[Narrator] The Pacific may be
home to ocean giants,
but it also has a wealth
of much smaller animals
that are just as important.
Over 2,000 miles away in the
middle of the Pacific Ocean,
is the island of Rarotonga
in the southern Cook Islands.
Here, National Geographic
Explorer Dr. Anya Brown
is partnering with local
marine biologists...
[Biologist]
We'll probably have you guys
jump in the water first.
[Narrator] ...who are
leading the charge
to save one of the ocean's
greatest treasures,
coral reefs.
[Anya Brown] If you were to look
at a coral, you might think
it was not alive and you would
think it's just a rock.
But they are animals,
but it also is part plant
and it's part mineral.
They're interconnected
and they're growing to create
a coral colony.
Corals can be purples, they can
be greens, they can be blues.
They're just awe inspiring.
[Narrator] The vibrant color
comes from tiny algae
that live inside
the coral tissue.
[Anya] So, corals are crazy.
There's nothing like it on land.
[Narrator] While reefs cover
just 1% of the ocean,
they support a quarter
of all marine species.
They're also very fragile,
especially when it comes to
changes in ocean temperature.
In the last 75 years,
we've lost half
of the world's coral reefs.
[Anya] What happens if we don't
have any corals anymore?
We don't have the fish
that rely on them.
If there's a big storm surge,
we don't have protection.
If we lose them,
we're going to care a lot,
so we need to care now.
[Narrator] To find ways
to save them,
Anya is teaming up with
colleague Dr. Rachel Bay.
[Anya] The corals got so big.
[Explorer] Yeah!
[Narrator] And local marine
biologist Siana Whatarau,
whose family have lived here
for generations.
[Siana Whatarau] I've heard so
many stories about what the reef
used to look like
in the Cook Islands.
There was all this biodiversity.
My biggest fear is that I'll
never be able to see that.
We'll just be left with
a skeleton of the past.
[Narrator] Saving these reefs
requires urgent action.
Just off the beach,
Siana and the team
are running
a groundbreaking experiment.
Clippings from different coral
structures, known as colonies,
are taken from
around the island
and grown here
in an artificial nursery.
[Anya] Everyone here thinks
of them as their children,
as our little coral babies.
[Narrator] Once they're big
enough, the team will test
how these corals cope with a
range of different temperatures
to see if some are more
heat tolerant than others.
[Siana] Where the nursery is,
it is literally my backyard
that I grew up with.
So it was really a great way for
me to give back to my community.
[Narrator] Siana keeps
a watchful eye on them.
[Siana] Essentially
I nurse these corals,
make sure that they're clean.
[Narrator]
Despite all this care,
not all the young
corals survive.
[Siana] When these corals died,
watching that happen
had an emotional toll that
I didn't think it would have.
[Narrator] After a year,
the healthy corals are ready
to be collected
and tested in the lab.
[Anya] They're so big.
They've grown up so much.
We've got our first two
plates worth of coral.
They're all looking awesome.
[laughs]
[Rachel Bay]
No sudden stops on the way home.
Precious cargo.
[Narrator]
Over the next 18 hours,
they'll submerge
their coral samples
in a range of temperatures,
warmer than the usual
80 degrees Fahrenheit
of the ocean.
[Anya]
Mimicking a marine heat wave.
It's like what a coral might
experience in the future.
[Narrator] When corals overheat,
the algae, which give them
their color, are expelled,
turning the reef white,
an event known as bleaching.
[Anya] Seeing a bleached reef,
it's really heartbreaking,
because these are corals that
have survived hundreds of years.
[Narrator] In their experiment,
they're testing
if any of the corals
are heat tolerant enough
to keep their color.
[Rachel] This is our lowest
heat temperature,
and it's lost almost
all of its pigments,
just so fully bleached.
[Anya] Oh, buddy.
[Rachel] Yeah.
And in contrast, you can see
this other colony
looks so happy and so colorful.
That just tells us
that these individuals
are pretty resilient.
[Anya] This one is colony 20,
and in all of the different
temperatures, it looks good.
[Narrator] These resilient
corals could help
the community here
restore their reefs
and boost coral conservation
across the Pacific.
[Anya] We see corals
that can withstand
pretty high temperatures.
It gives me hope that
that can help support
the next generation of corals.
[Narrator] From the Pacific,
the Great Ocean Conveyor Belt
carries water west into
the warmest of all our oceans,
the Indian Ocean.
It's known for its idyllic
tropical islands
and shallow turquoise waters,
with majestic manta rays
and 20-ton whale sharks.
But 90% of it is deep ocean
and has never been
properly surveyed.
National Geographic Explorer
Sheena Talma,
the first deep sea scientist
from the Seychelles,
is determined to change that.
[Sheena Talma] Understanding
what lives in the deep sea,
what lives where and whether
they look healthy
is really important.
[Narrator] For the people
of the Seychelles,
understanding what lives
beneath the waves
is vital for managing
the fisheries
that help sustain
this island nation;
but it's not easy.
[Sheena] One of the hardest
parts of deep sea research
is it's really expensive.
[Narrator] Historically,
exploring the deep has required
huge research ships
to carry large ROVs,
which were beyond the reach
of smaller island nations.
But all that's about to change.
[Sheena]
Zero, zero, six, two, seven.
[Narrator] In the deep waters
of the western Indian Ocean,
Sheena's joining
a team of scientists
from around the world to test
a lightweight camera system
called a lander.
It's designed to be launched
from a small boat
down to a depth
of over 10,000 feet.
[Sheena] It's the first day
today where a team is going out
to test our equipment.
[Narrator] It's an opportunity
to share scientific expertise
across the globe,
from the Caribbean
to the Seychelles.
[Sheena] Some of the teams
that we have here
have never done
any expeditions before.
Some are deep sea scientists.
This cross-pollination
of ideas, of knowledge,
it's a very exciting
way of learning.
[Narrator] Sheena can take
this knowledge
back to her community at home.
[Sheena] And showcase how
we can build equipment
that we can share, not only
regionally, but globally.
It's gonna sink down,
and then after a few hours,
we'll see what we see.
[Narrator] To give them
the best chance,
the lander carries something
to tempt the creatures
of the deep.
[Anthony Bernard] They are
baited, so it should attract
the scavengers
and the predators.
Just keen to see
what's down there.
[Narrator] For Sheena,
one creature in particular
could be a sign that
the deep sea here is thriving.
[Sheena] If you have big
predatory sharks around,
it's a good thing to see,
because they're great indicators
of ecosystem health.
[Crewmember] Let's see.
[Narrator] The moment of truth.
Soon after landing, the bait
begins to attract the creatures
of this rarely seen world.
A deep sea violet cod
with big eyes
to help navigate
in the darkness.
[Crewmember] Oh, cutie! Ohhh.
[Sheena] You see crabs come in,
and then suddenly, an eel.
[Crewmember] So cool.
[Narrator] Then the animal
Sheena was hoping to see.
[Sheena] What! That's so cool.
[Narrator] Sharks.
Lots of them.
Over 50% of shark species
live in the deep sea.
With the test
successfully completed,
Sheena will take
the lander home
to help the Seychellois
community better understand
what lives in their
deepest waters.
[Sheena] In five to 10 years,
I would love to see
the Seychelles become
a center of excellence
for deep sea research
in the Indian Ocean.
[Narrator]
From the Indian Ocean,
the deep sea currents
carry water west
around the southern tip of
Africa and into the Atlantic,
our stormiest ocean.
The Atlantic covers more than
40 million square miles,
and it's still growing.
As our planet warms
and glaciers and polar
ice sheets melt,
more water floods
into the ocean,
raising sea levels and pushing
storm surges further inland.
Nowhere feels this more sharply
than The Gambia,
the smallest country
in West Africa
where nearly
half a million people
live close to its
low-lying coast.
[Maiyai Taal Hocheimy] The ocean
is a part of who we are
as Gambians, part of who I am.
So the Atlantic Ocean is really
a very significant part
of my life.
[Narrator] National Geographic
Explorer Mayai Taal Hocheimy
is leading an expedition
just off The Gambia's coast.
[Maiyai] The aims of
the expedition was to help
understand what is going on
with our capital, Banjul.
[Narrator] If nothing's done,
it's predicted the Banjul
will be underwater by 2100.
To come up with solutions
to save the capital,
Maiyai is training
local students
to measure ocean depth
and water currents.
[Maiyai] It's important for us
to collect the data
to verify the models and
create possible new models.
[Narrator] These first results
will create a baseline.
[Maiyai]
Alright, we're good to go.
[Narrator] So the team can
monitor future changes
in sea level rise.
[Maiyai] I teach you
so you can teach others. Right?
Alright, let me grab the GPS.
It's really important to train
the next generation
of environmental stewards.
I mean, if you want
to change a nation,
you start with the young people.
[Narrator] The expedition is
a great opportunity
for research assistant
Amuzo Nkamnebe
to hone her skills
as a marine scientist.
[Amuzo Nkamnebe] When I'm in
the field, I just feel alive.
This was what I was meant to be.
This is what I was made for.
[Narrator] Together, they'll
track how the Atlantic Ocean
is encroaching
on their capital, Banjul,
and come up with solutions
to save it.
One of these solutions could be
right on their doorstep.
The mangrove forests
along the Gambia River.
Mangroves grow
across the tropics.
Their tangled roots
shelter young sharks
and provide a nursery for fish.
They also act as
nature's storm barrier
by slowing down wave energy.
[Maiyai] It's sort of
like a buffer zone
from potential sea level rise.
[Narrator] Maiyai wants to know
if the mangroves around Banjul
are robust enough to protect
the capital long term.
So she's called in fellow
National Geographic Explorer
Dr. Angelo Bernardino,
a mangrove specialist
from Brazil.
[Angelo Bernardino] So we're
here to try to understand
the importance of this area
for Gambia as a whole.
You've been working here
for several years now, right?
[Maiyai] Well, this is
where I grew up.
This is where, you know, I swam.
This is where I get
my food source from.
So this is my life.
[Narrator] They plan to carry
out the first-ever health check
of these mangroves
by collecting soil samples
from deep in the swamps.
[Angelo] Maybe over
those roots there.
You see those roots?
Maybe somewhere you can...
[Narrator] Twice daily
salty sea water
floods in and out
of the entire forest.
[Angelo] In a few hours from
now, it's gonna be inundated.
So we need to be out of here
before that.
[Narrator] The web-like roots
that slow surging seawater
don't make working here easy,
but Angelo is right at home.
[Angelo] It's beautiful. Right?
It's gorgeous. Right, Jasseh?
[Jasseh]
Yes. And it's very dense.
[Angelo] Very dense.
And, yeah, very slow work,
but it's great.
[Narrator] With the tide
soon returning,
the team gets to work.
[Maiyai] Go a little bit down.
[Angelo] Okay, so let's take
the first sample.
We want to get this deep soil,
so we have a better
representation
of the full soil profile.
[Maiyai] Get ready to go up.
[Narrator] The secret to
a thriving mangrove forest
is having deep,
nutrient-rich soil.
Getting to it takes practice.
Jasseh is becoming
a professional.
[Jasseh] Yes.
Good job, man,
very nice core, huh?
[Angelo] So we are seeing
very rich organic soils here.
This tells us that this area
trees are building up soil
for a long time, likely
hundreds and hundreds of years.
The soil is coming up
all the time.
That's why they are really good
for coastal protection,
because as the sea level rises,
the mangrove forest
rises with it.
[Narrator] If these mangroves
stay healthy,
they'll continue to build up
soil and shield Banjul.
[Maiyai] Making sure that
we understand this ecosystem
to value it so that we can
continue to protect it.
[Narrator] The lessons learned
here could help
many coastal communities
across our one ocean.
[Angelo]
Everywhere in the world,
we're seeing rapid
changes in climate,
and mangroves are becoming
nature's solution.
Mangroves will help
coastal cities worldwide
in the next decades.
[Narrator] The final part of
the Great Ocean Conveyor Belt
carries water north
into the smallest
of all our ocean basins,
the Arctic.
In the winter, sea ice blankets
6 million square miles.
A vital refuge for marine
mammals unique to the Arctic.
This vast, icy wilderness
is inaccessible
for most of the year.
Then, for a few weeks
in summer,
melting ice opens up the most
remote reaches for exploration.
National Geographic Explorer
Dr. Kristina Brown...
[Kristina Brown]
Do you want to take up
a little bit of the slack?
[Narrator] ...has been invited
by the local Inuit community...
[Kristina] You can come back up.
[Narrator] ...to explore one
of the most isolated regions
of Arctic Canada.
A secluded marine bay
called Aimmatquttak,
or the Sherman Basin.
Using a repurposed
fishing boat,
she plans the first known
scientific study
of the waters here.
[Kristina] It's super exciting.
I mean, we couldn't even
navigate into the basin
without the help of elders
and the guidance
of the local community.
[Narrator] Inuk elder
Saul Aksalook Qirqniq
knows these waters
better than anyone.
[Kristina] I've come in to
collaborate with the community
and try to answer the questions
that they have.
[Crewmember] Come on over, Saul.
[Crewmember] Is this our
best way to come in?
Yeah, you can go straight there.
When I was a little boy,
we used to have
a winter camp over there.
[Crewmember] Oh, okay.
[Narrator] Generations of Inuit
have foraged and hunted
in the Sherman Basin.
It's an area that's sacred
to them, rich with life.
[Kristina] This project is
really unique in that it started
from questions that
the community had.
[Man] Look at all of them.
[Kristina] Why are there so many
fish in the region?
What makes the seals
so fat and so healthy?
What's living at the bottom
of the ocean?
[Narrator] To try and answer
these questions,
Kristina is joined
by Lorenza Kamimmalik
and Erwin Nuliayok Kihoak.
[Kristina] Having the youth
involved really provides
an important bridge from science
to the local community.
[Narrator] The team wants
to explore the seabed
to find out what
lives down there.
[Crewmember] Let it go on down.
[Narrator] This will be the
first time anyone has ever seen
the sea floor in this area.
[Crewmember]
Oh, there's the bottom.
[Kristina] Oh, wow.
[Narrator] It's full of life.
In total,
they document over 150
plant and animal species.
[Lorenza Kamimmalik] My
experience was pretty amazing.
There's a lot more that I would
want to learn about the ocean.
[Narrator] In Lorenza
and Erwin's lifetime,
it's predicted that
the Arctic could change
beyond all recognition.
[Erwin Nuliayok Kihoak]
Temperatures getting warmer,
summers getting longer.
Winter doesn't come that early.
[Narrator] As the climate
shifts around them,
being part
of grassroots science
will help the next generation
prepare for the future.
[Kristina] The Arctic is warming
at four times the rate
of the rest of the planet.
If we can understand how
the ecosystem might change,
we hopefully can bring
that information
back to the communities
so that they can continue
to thrive and be resilient.
[Narrator] With expeditions
spanning all five ocean basins,
following the Great Ocean
Conveyor Belt,
it's clear how each
is connected
by deep water currents.
But new science has revealed
just how little we know
about the deepest realms
of our ocean.
[Katy Croff Bell]
We've only seen about 0.001%
of the deep ocean, which covers
about two thirds of our planet.
Just imagine what we're gonna
find in the other 99.999%.
[Narrator] National Geographic
Explorer Dr. Katy Croff Bell
is setting out
to completely revolutionize
the future of deep sea
exploration.
[Katy] I am so excited about
what we're on the cusp
of right now.
[Narrator] She's created
a lightweight device,
a quarter the size of a lander,
that can reach depths
of nearly four miles.
And it's called DORIS,
the Deep Ocean Research
and Imaging System.
[Katy] I do think that DORIS is
gonna be a huge game changer.
A system like this--low cost,
but easy enough to use
just straight out of the box--
doesn't exist.
[Narrator] The simplicity
of the system will transform
who can explore the deep.
[Katy] We'll be able to deploy
in countries and communities
that have never, ever been
able to do so before.
Let's go.
[Narrator] Time to see what
this prototype is capable of.
[Katy] Oh, and there's
some kelp. Ooh, a fish!
This is huge--DORIS' first
deployment in open ocean.
It is working as it should.
[Narrator] Katy has huge plans
for this revolutionary
piece of technology.
[Katy] We're putting together
a set of 10,000 points,
and you can see how
distributed they are.
It will give us this much more
representative look
at the global deep sea floor.
We're hoping that hundreds,
thousands of these systems
will be out exploring the ocean
in the coming years.
[Narrator] Over the course
of three years,
the National Geographic
Explorer snapshot
of ocean health
reveals reasons
to be optimistic.
In the Southern Ocean,
the team's discoveries
will reinforce
the need to protect
Antarctica's pristine
deep waters.
In the Cook Islands,
Anya's super corals offer
a glimmer of hope
for reefs in a warming world.
And in the Pacific,
Kim is building AI models
based on the aerial surveys
to detect and understand
the krill swarms
feeding blue whales.
Together, these explorers
are revealing
how deeply connected
our seas truly are
in one vast ocean.
more than 70% of our planet
and is packed full of life.
[Explorer 1]
The health of the planet
depends on a healthy ocean.
[Explorer 2]
It's absolutely essential.
[Narrator]
But as the climate heats up,
our seas are under pressure
like never before.
[Explorer 3]
We're seeing an ecosystem
that's changing in real time.
[Explorer 1] It could have
devastating consequences.
[Narrator] Now a team
of Explorers,
part of the National Geographic
and Rolex
Perpetual Planet
Ocean Expeditions,
is launching a series
of groundbreaking missions...
[Explorer 4] Just imagine
what we're gonna find!
[Narrator]
...to better understand
and protect our seas.
Traveling from pole to pole
across all five ocean basins...
[Diver] Go!
[Narrator] ...from seashore
to seafloor.
[Explorer 4] We've seen more
of the surface of Mars
than we have
of our own deep sea.
[Narrator] In a new era
of ocean exploration,
they'll team up
with coastal communities,
combining timeless wisdom
with cutting edge technology.
[Explorer 2] We're really
pushing the boundaries
of what we think we can do.
[Explorer 4] It works.
[Explorer 2]
It's not the time to give up!
[Narrator] Working together,
they'll help us to reimagine
our world, not divided by land,
but united as one ocean.
The Southern Ocean,
the most remote on the planet.
Spanning 8 million
square miles,
these icy blue waters are
a vital feeding ground
for ocean giants.
Because it's so isolated,
much of what happens here
remains a mystery
for oceanographers.
[Andrew Thurber]
One of the things I love
about the Southern Ocean
is it's full of surprises.
Everything is unique there.
[Narrator] This team of
National Geographic Explorers
is on a pioneering voyage
in collaboration
with the Schmidt
Ocean Institute,
aboard its research vessel,
the Falkor (too).
[Allison Fong] The Southern
Ocean Expedition is unique
because we don't typically
put as many diverse themes
of science on one ship.
[Narrator] The team believes
that the key to understanding
the abundance of life
on the surface
is to discover what's
going on deep below.
To do this, they're using
a state-of-the-art
remotely operated vehicle,
or ROV, named SuBastian.
The plan is to deploy the ROV
down to 13,000 feet,
nearly two and a half miles,
the deepest ever survey of this
part of the Southern Ocean.
[Andrew] We want to peer into
those icy, deep, dark depths
to uncover things that nobody
has ever seen before.
[Narrator] One of the things
oceanographer
Dr. Andrew Thurber wants to
find is a hydrothermal vent.
[Andrew] Hydrothermal vent,
where superheated fluid
is being pumped
out of the seafloor,
and it creates these habitats
that fuel many
different organisms.
[Kim Bernard] We're about
to deploy the ROV
for the very first time.
I can't wait. I can't wait.
I'm just really excited to see
what it looks like down there.
[Narrator] The Explorers crowd
the control room
to watch as the ROV SuBastian
descends into the alien-like
world beneath.
[Kim] As the ROV
is descending
through the water column, these
things are sort of shooting past
so fast that it's a little bit
like the start to Star Wars.
It looks like you're in the
middle of space, just flying.
[Narrator] At 650 feet...
[Andrew] Oh!
[Narrator] All natural light
disappears...
[Crewmember] Wow.
[Narrator] ...opening up
a rarely seen world.
[Kim] There is so much life
within the water column.
It's alive with beings.
[chatter]
[Narrator] Then the team spots
something truly extraordinary.
[Andrew]
Wow, it's a huge squid.
Wow!
It's about a meter and a half.
It's so rare it doesn't
have a common name.
It's just an amazing experience
to be able to interact
with this organism
that had never been seen
before while it was alive.
[Narrator] After four hours,
the ROV SuBastian touches down
on the seafloor.
The deepest ever glimpse
into this area
of the Southern Ocean.
Now the team begin their search
for the mineral rich,
super hot water
of a hydrothermal vent
by looking for signs of life.
[Andrew] The entire deep sea has
no energy from the sun.
It's a food desert.
Hydrothermal vents provide
energy and nutrients;
this wealth of food.
And so it creates these oases
of strange biological oddities.
Let me see.
[Narrator] One of those oddities
is a dumbo octopus.
[Crewmember] Wow.
[Narrator] The deepest living
octopus known to science,
named for its large
ear-like fins.
Look at me, I can't wipe
this smile off my face.
[Narrator] There are plenty
of unique creatures.
But no sign of a vent.
[Andrew]
It's 7:10 in the morning,
we've been up all night.
Had an amazing evening.
One of the most amazing seafloor
environments on the planet.
[Narrator] Then, looming
out of the abyss...
...a towering chimney,
30 feet tall appears.
[Andrew] Found some little
shimmering water.
[Leigh Torres] The heat is just
coming off everywhere.
[Andrew]
It's a hydrothermal vent.
Just so everybody's
equally excited,
this is the most southerly
deep sea vent
known on the planet.
First ROV dive.
The first real view
of this habitat ever.
[Explorer 1] 234, 243...
246 degrees Celsius.
[Explorer 2] Amazing.
[Explorer 1] That is hot.
[Narrator] Despite
temperatures of nearly
500 degrees Fahrenheit,
there's all sorts of life
around the vent,
including tiny animals
that Dr. Kim Bernard
loves more than anything.
[Kim] Oh, look, there! Guys!
The krill.
[Narrator] Krill.
[Kim] We got krill!
[Explorer] Yay! Krill!
[Kim] This is so exciting!
So they look a little bit
like shrimp, but they're not.
They're pretty cute.
They're just like looking at you
with their big eyes,
swimming around,
sometimes doing backflips.
The krill are coming in.
[chuckles]
To me, Antarctic krill
are the superheroes
of the Southern Ocean.
They are a vital part
of that ecosystem.
Penguins, seals,
whales, seabirds
all feed on Antarctic krill.
[Narrator] Krill have been
studied at the surface,
but this is the first time
they have ever been found
at a hydrothermal vent.
[Kim] I was not expecting
to see krill.
Oh, my god,
they keep showing up!
[Narrator] Incredibly, Kim
discovers most of the krill
at the vent are carrying eggs
and are ready to spawn.
This hidden deep sea nursery
could be a vital lifeline,
sustaining marine life across
the entire Southern Ocean.
While the ROV team continue
to explore in the depths,
Dr. Allison Fong is topside,
leading a dangerous mission...
[Allison] Safety first.
[Narrator] ...to study
the sea ice that in winter
can cover nearly half
of the Southern Ocean.
As the climate warms, our
oceans absorb the excess heat.
With Antarctic waters
soaking up 75% of it.
But in recent years,
the impact is starting to show
as the sea ice melts
at an alarming rate.
[Allison] In light of the fact
that we know we're losing
sea ice, what happens?
That was the main goal
in the Southern Ocean
expedition for me.
[Narrator] Allison wants to take
a sample of the sea ice.
Locked in the ice are
tiny creatures called microbes
that play a surprisingly
important role
in all of our lives.
[Allison] Microbes are
responsible for creating
50% of the oxygen that
we breathe on this planet.
[Narrator] That's more than
all the world's
rain forests combined.
[Allison] Every other breath
that you and I take
is an oxygen molecule that
was produced by a microbe
that lives in the ocean.
[Narrator] Allison wants to find
out how the sea ice microbes
are coping in
our changing climate.
To take a sample, she needs
to get onto an ice floe,
but not just any ice floe.
[Allison] No, that's too tall.
[Narrator] It has to be
just right.
[Allison] Ooh, it's thick?
It's thick, and it's missing
a lot of the little...
[Narrator] Thin enough
so they can take a sample
through to the sea below.
[Allison] Just ahead,
there's some flat ice.
It looks like a flat
piece of paper.
You're gonna have
to approach real slow.
[Crewmember] Yeah.
[Narrator] But thick enough to
stop them from falling through.
[Allison] Perfect.
[Narrator] This is the most
precarious part
of their mission.
Checking the ice
will hold their weight.
[Allison] When you see large
blocks of ice floating around
with 4,000 meters
of ocean below it,
and I'm supposed to stand
on that one meter of ice
and put holes in it
to collect samples?
It's crazy.
Alright. Be very careful
of the edge.
But it's also really special,
because it's like walking
on water, right?
So you should walk where I walk.
[Narrator] Most of the sea ice
microbes live on the underside
of the ice
in the bottom five inches.
To reach them, the team use
a corkscrew-like core,
designed to drill through
the ice and lift out a sample.
Some inquisitive neighbors,
Adelie penguins,
come to check out
the commotion.
[Allison] Oh, no.
What's happening?
The nature of
working on sea ice
is that it is predictably
unpredictable.
[Narrator] Today, that
unpredictability isn't working
in their favor,
making this usually
simple task harder.
[Allison] It's a lot of water.
We really didn't expect
the whole ice column
to be completely
inundated with sea water.
It's like wet concrete.
We're just not able to get
the corer through that,
because it's just too heavy.
So we might have to call it.
[Narrator] The team has one
last chance to get their core.
[Crewmember] It went through.
[Allison] It went through.
Oh, my god, I'm so relieved.
You can see
the sea ice algae in here.
Do you see the little specks?
[Crewmember]
I do see the specks.
[Allison]
That's the sea ice algae!
Good job.
[Narrator] When microbes gather
in huge numbers
at the bottom of the ice,
they can form colorful
algal blooms.
[Allison] You can really stick
your nose in there,
you can really smell it.
Yes. That's algae, yeah.
[Crewmember] I can smell it
from here. Yes. That's algae.
[Narrator] By collecting these
microbes for further analysis,
Allison hopes
to better understand
how these lungs of the sea are
coping in our warming world.
[Allison] Almost all of
the animals we see on our planet
exist because microbes
produce oxygen.
So if you love animals,
you need to love microbes,
and more than that,
you need to love sea ice.
Woo, what a day!
[Crewmember] Thank you.
[Allison] Thank you, ice floe!
[Narrator] The Southern Ocean
is connected
to all the other ocean basins
by deep water currents known as
the Great Ocean Conveyor Belt.
From Antarctica
it flows eastward
before peeling off
into the Pacific.
Covering 60 million
square miles,
the Pacific is the largest
of all our oceans.
Bigger than all the world's
land combined.
And it's home to the largest
animal that's ever lived.
The blue whale,
up to 100 feet long
and weighing up to 200 tons.
Most blue whales migrate
across oceans to find food.
But off the west coast
of New Zealand,
the South Taranaki Bight is
home to a special population
that call these waters
home year round.
Now, a team of Explorers,
including krill expert
Kim Bernard
from the Southern Ocean
Expedition
and blue whale expert
Dr. Leigh Torres...
[Leigh Torres] The survey team
is scanning the horizon,
looking for blows.
[Narrator] ...are heading out
to discover how rapid changes
in ocean temperature are
impacting these marine giants.
The expedition is a partnership
with the local Maori community.
For Abraham Fletcher, blue
whales hold deep significance.
[Abraham Fletcher]
In our culture they're seen
as these, these guidance
or symbols of wisdom.
It's all woven into
who we are as Maoris.
Our ancestors navigated
using the tides, the birds,
even using the whales
to find safe passage,
and that's my connection here.
[Narrator] The team have been
monitoring this population
for several years,
recording whale numbers
as well as the density
of their prey, krill.
[Kim] So the krill species here
is the only thing
that these blue whales eat.
Blue whales are
massive creatures,
and they're eating
these tiny krill,
which is insane
if you think about it.
[Narrator] The best way
to find the whales
is to find the krill, and that
means taking to the air.
[Kim] We recruited
an aerial survey team,
and that was
a real game changer.
[Narrator] The survey reveals
huge swarms of krill
at the surface.
[Leigh] Wow, look at the size
of that swarm.
[Kim] It's about 2,000
square meters.
[Leigh] That's amazing.
[Kim] It's huge.
[Leigh] Great to have
this eye in the sky.
[Kim] Yeah.
[Narrator] Now the crew knows
where to direct their search.
[Leigh] There, there,
there, there, there.
There it is. Woo! Finally.
[Narrator] From the boat it's
hard to see what's going on,
but from the air,
the team witness
something extraordinary.
Blue whale behavior
known as lunge feeding.
[Leigh] A third of their body is
their head and their mouth,
which is pretty huge.
They'll be going really fast,
and then they'll
open up their mouth
to engulf that
big patch of krill.
But that really
slows them way down.
It's like slamming
on the brakes.
[Narrator] With the krill
swarming at the surface,
the whales can scoop
up to half a million calories
in one mouthful.
With all that food, this year,
they appear to be doing well.
[Leigh] There's two whales
in front of us.
It's a mom and calf.
It's really exciting to see
moms and calves,
that, that means the ecosystem
is doing okay.
[Narrator] The South Taranaki
Bight is a hot spot
for blue whales, and thanks
to the aerial surveys,
the team can see why.
[Kim] In this area we get
what is called upwelling,
so the deeper waters
move up to the surface.
In that upwelling plume
of more nutrient-rich waters,
that's where we're seeing
the krill at the surface,
and the whales,
they're feeding on them.
[Narrator] These unique
conditions explain
why the whales stay here
year round.
[Leigh] This one is
just about to munch
on that big krill swarm there.
[Narrator] But it also makes
them vulnerable
to rapid changes
in ocean temperature.
[Kim] In warmer
ocean conditions,
the upwelling that brings
nutrients into the area
tends to shut off.
We tend to see fewer krill
and fewer whales.
[Narrator] The team's findings
will help inform
how best to protect
the planet's biggest creatures,
both in New Zealand
and across our one ocean.
[Kim] What we learn about
how marine heatwaves
affect the krill
and the blue whales
can then be transferred
to other marine systems
throughout the world's oceans.
That's the part
that gives me hope.
[Abraham] I think it's amazing,
this interface between
Western science,
but also weaving in, you know,
our Maori perspectives.
I think it can form
something very beautiful.
[squeaking]
[Narrator] The Pacific may be
home to ocean giants,
but it also has a wealth
of much smaller animals
that are just as important.
Over 2,000 miles away in the
middle of the Pacific Ocean,
is the island of Rarotonga
in the southern Cook Islands.
Here, National Geographic
Explorer Dr. Anya Brown
is partnering with local
marine biologists...
[Biologist]
We'll probably have you guys
jump in the water first.
[Narrator] ...who are
leading the charge
to save one of the ocean's
greatest treasures,
coral reefs.
[Anya Brown] If you were to look
at a coral, you might think
it was not alive and you would
think it's just a rock.
But they are animals,
but it also is part plant
and it's part mineral.
They're interconnected
and they're growing to create
a coral colony.
Corals can be purples, they can
be greens, they can be blues.
They're just awe inspiring.
[Narrator] The vibrant color
comes from tiny algae
that live inside
the coral tissue.
[Anya] So, corals are crazy.
There's nothing like it on land.
[Narrator] While reefs cover
just 1% of the ocean,
they support a quarter
of all marine species.
They're also very fragile,
especially when it comes to
changes in ocean temperature.
In the last 75 years,
we've lost half
of the world's coral reefs.
[Anya] What happens if we don't
have any corals anymore?
We don't have the fish
that rely on them.
If there's a big storm surge,
we don't have protection.
If we lose them,
we're going to care a lot,
so we need to care now.
[Narrator] To find ways
to save them,
Anya is teaming up with
colleague Dr. Rachel Bay.
[Anya] The corals got so big.
[Explorer] Yeah!
[Narrator] And local marine
biologist Siana Whatarau,
whose family have lived here
for generations.
[Siana Whatarau] I've heard so
many stories about what the reef
used to look like
in the Cook Islands.
There was all this biodiversity.
My biggest fear is that I'll
never be able to see that.
We'll just be left with
a skeleton of the past.
[Narrator] Saving these reefs
requires urgent action.
Just off the beach,
Siana and the team
are running
a groundbreaking experiment.
Clippings from different coral
structures, known as colonies,
are taken from
around the island
and grown here
in an artificial nursery.
[Anya] Everyone here thinks
of them as their children,
as our little coral babies.
[Narrator] Once they're big
enough, the team will test
how these corals cope with a
range of different temperatures
to see if some are more
heat tolerant than others.
[Siana] Where the nursery is,
it is literally my backyard
that I grew up with.
So it was really a great way for
me to give back to my community.
[Narrator] Siana keeps
a watchful eye on them.
[Siana] Essentially
I nurse these corals,
make sure that they're clean.
[Narrator]
Despite all this care,
not all the young
corals survive.
[Siana] When these corals died,
watching that happen
had an emotional toll that
I didn't think it would have.
[Narrator] After a year,
the healthy corals are ready
to be collected
and tested in the lab.
[Anya] They're so big.
They've grown up so much.
We've got our first two
plates worth of coral.
They're all looking awesome.
[laughs]
[Rachel Bay]
No sudden stops on the way home.
Precious cargo.
[Narrator]
Over the next 18 hours,
they'll submerge
their coral samples
in a range of temperatures,
warmer than the usual
80 degrees Fahrenheit
of the ocean.
[Anya]
Mimicking a marine heat wave.
It's like what a coral might
experience in the future.
[Narrator] When corals overheat,
the algae, which give them
their color, are expelled,
turning the reef white,
an event known as bleaching.
[Anya] Seeing a bleached reef,
it's really heartbreaking,
because these are corals that
have survived hundreds of years.
[Narrator] In their experiment,
they're testing
if any of the corals
are heat tolerant enough
to keep their color.
[Rachel] This is our lowest
heat temperature,
and it's lost almost
all of its pigments,
just so fully bleached.
[Anya] Oh, buddy.
[Rachel] Yeah.
And in contrast, you can see
this other colony
looks so happy and so colorful.
That just tells us
that these individuals
are pretty resilient.
[Anya] This one is colony 20,
and in all of the different
temperatures, it looks good.
[Narrator] These resilient
corals could help
the community here
restore their reefs
and boost coral conservation
across the Pacific.
[Anya] We see corals
that can withstand
pretty high temperatures.
It gives me hope that
that can help support
the next generation of corals.
[Narrator] From the Pacific,
the Great Ocean Conveyor Belt
carries water west into
the warmest of all our oceans,
the Indian Ocean.
It's known for its idyllic
tropical islands
and shallow turquoise waters,
with majestic manta rays
and 20-ton whale sharks.
But 90% of it is deep ocean
and has never been
properly surveyed.
National Geographic Explorer
Sheena Talma,
the first deep sea scientist
from the Seychelles,
is determined to change that.
[Sheena Talma] Understanding
what lives in the deep sea,
what lives where and whether
they look healthy
is really important.
[Narrator] For the people
of the Seychelles,
understanding what lives
beneath the waves
is vital for managing
the fisheries
that help sustain
this island nation;
but it's not easy.
[Sheena] One of the hardest
parts of deep sea research
is it's really expensive.
[Narrator] Historically,
exploring the deep has required
huge research ships
to carry large ROVs,
which were beyond the reach
of smaller island nations.
But all that's about to change.
[Sheena]
Zero, zero, six, two, seven.
[Narrator] In the deep waters
of the western Indian Ocean,
Sheena's joining
a team of scientists
from around the world to test
a lightweight camera system
called a lander.
It's designed to be launched
from a small boat
down to a depth
of over 10,000 feet.
[Sheena] It's the first day
today where a team is going out
to test our equipment.
[Narrator] It's an opportunity
to share scientific expertise
across the globe,
from the Caribbean
to the Seychelles.
[Sheena] Some of the teams
that we have here
have never done
any expeditions before.
Some are deep sea scientists.
This cross-pollination
of ideas, of knowledge,
it's a very exciting
way of learning.
[Narrator] Sheena can take
this knowledge
back to her community at home.
[Sheena] And showcase how
we can build equipment
that we can share, not only
regionally, but globally.
It's gonna sink down,
and then after a few hours,
we'll see what we see.
[Narrator] To give them
the best chance,
the lander carries something
to tempt the creatures
of the deep.
[Anthony Bernard] They are
baited, so it should attract
the scavengers
and the predators.
Just keen to see
what's down there.
[Narrator] For Sheena,
one creature in particular
could be a sign that
the deep sea here is thriving.
[Sheena] If you have big
predatory sharks around,
it's a good thing to see,
because they're great indicators
of ecosystem health.
[Crewmember] Let's see.
[Narrator] The moment of truth.
Soon after landing, the bait
begins to attract the creatures
of this rarely seen world.
A deep sea violet cod
with big eyes
to help navigate
in the darkness.
[Crewmember] Oh, cutie! Ohhh.
[Sheena] You see crabs come in,
and then suddenly, an eel.
[Crewmember] So cool.
[Narrator] Then the animal
Sheena was hoping to see.
[Sheena] What! That's so cool.
[Narrator] Sharks.
Lots of them.
Over 50% of shark species
live in the deep sea.
With the test
successfully completed,
Sheena will take
the lander home
to help the Seychellois
community better understand
what lives in their
deepest waters.
[Sheena] In five to 10 years,
I would love to see
the Seychelles become
a center of excellence
for deep sea research
in the Indian Ocean.
[Narrator]
From the Indian Ocean,
the deep sea currents
carry water west
around the southern tip of
Africa and into the Atlantic,
our stormiest ocean.
The Atlantic covers more than
40 million square miles,
and it's still growing.
As our planet warms
and glaciers and polar
ice sheets melt,
more water floods
into the ocean,
raising sea levels and pushing
storm surges further inland.
Nowhere feels this more sharply
than The Gambia,
the smallest country
in West Africa
where nearly
half a million people
live close to its
low-lying coast.
[Maiyai Taal Hocheimy] The ocean
is a part of who we are
as Gambians, part of who I am.
So the Atlantic Ocean is really
a very significant part
of my life.
[Narrator] National Geographic
Explorer Mayai Taal Hocheimy
is leading an expedition
just off The Gambia's coast.
[Maiyai] The aims of
the expedition was to help
understand what is going on
with our capital, Banjul.
[Narrator] If nothing's done,
it's predicted the Banjul
will be underwater by 2100.
To come up with solutions
to save the capital,
Maiyai is training
local students
to measure ocean depth
and water currents.
[Maiyai] It's important for us
to collect the data
to verify the models and
create possible new models.
[Narrator] These first results
will create a baseline.
[Maiyai]
Alright, we're good to go.
[Narrator] So the team can
monitor future changes
in sea level rise.
[Maiyai] I teach you
so you can teach others. Right?
Alright, let me grab the GPS.
It's really important to train
the next generation
of environmental stewards.
I mean, if you want
to change a nation,
you start with the young people.
[Narrator] The expedition is
a great opportunity
for research assistant
Amuzo Nkamnebe
to hone her skills
as a marine scientist.
[Amuzo Nkamnebe] When I'm in
the field, I just feel alive.
This was what I was meant to be.
This is what I was made for.
[Narrator] Together, they'll
track how the Atlantic Ocean
is encroaching
on their capital, Banjul,
and come up with solutions
to save it.
One of these solutions could be
right on their doorstep.
The mangrove forests
along the Gambia River.
Mangroves grow
across the tropics.
Their tangled roots
shelter young sharks
and provide a nursery for fish.
They also act as
nature's storm barrier
by slowing down wave energy.
[Maiyai] It's sort of
like a buffer zone
from potential sea level rise.
[Narrator] Maiyai wants to know
if the mangroves around Banjul
are robust enough to protect
the capital long term.
So she's called in fellow
National Geographic Explorer
Dr. Angelo Bernardino,
a mangrove specialist
from Brazil.
[Angelo Bernardino] So we're
here to try to understand
the importance of this area
for Gambia as a whole.
You've been working here
for several years now, right?
[Maiyai] Well, this is
where I grew up.
This is where, you know, I swam.
This is where I get
my food source from.
So this is my life.
[Narrator] They plan to carry
out the first-ever health check
of these mangroves
by collecting soil samples
from deep in the swamps.
[Angelo] Maybe over
those roots there.
You see those roots?
Maybe somewhere you can...
[Narrator] Twice daily
salty sea water
floods in and out
of the entire forest.
[Angelo] In a few hours from
now, it's gonna be inundated.
So we need to be out of here
before that.
[Narrator] The web-like roots
that slow surging seawater
don't make working here easy,
but Angelo is right at home.
[Angelo] It's beautiful. Right?
It's gorgeous. Right, Jasseh?
[Jasseh]
Yes. And it's very dense.
[Angelo] Very dense.
And, yeah, very slow work,
but it's great.
[Narrator] With the tide
soon returning,
the team gets to work.
[Maiyai] Go a little bit down.
[Angelo] Okay, so let's take
the first sample.
We want to get this deep soil,
so we have a better
representation
of the full soil profile.
[Maiyai] Get ready to go up.
[Narrator] The secret to
a thriving mangrove forest
is having deep,
nutrient-rich soil.
Getting to it takes practice.
Jasseh is becoming
a professional.
[Jasseh] Yes.
Good job, man,
very nice core, huh?
[Angelo] So we are seeing
very rich organic soils here.
This tells us that this area
trees are building up soil
for a long time, likely
hundreds and hundreds of years.
The soil is coming up
all the time.
That's why they are really good
for coastal protection,
because as the sea level rises,
the mangrove forest
rises with it.
[Narrator] If these mangroves
stay healthy,
they'll continue to build up
soil and shield Banjul.
[Maiyai] Making sure that
we understand this ecosystem
to value it so that we can
continue to protect it.
[Narrator] The lessons learned
here could help
many coastal communities
across our one ocean.
[Angelo]
Everywhere in the world,
we're seeing rapid
changes in climate,
and mangroves are becoming
nature's solution.
Mangroves will help
coastal cities worldwide
in the next decades.
[Narrator] The final part of
the Great Ocean Conveyor Belt
carries water north
into the smallest
of all our ocean basins,
the Arctic.
In the winter, sea ice blankets
6 million square miles.
A vital refuge for marine
mammals unique to the Arctic.
This vast, icy wilderness
is inaccessible
for most of the year.
Then, for a few weeks
in summer,
melting ice opens up the most
remote reaches for exploration.
National Geographic Explorer
Dr. Kristina Brown...
[Kristina Brown]
Do you want to take up
a little bit of the slack?
[Narrator] ...has been invited
by the local Inuit community...
[Kristina] You can come back up.
[Narrator] ...to explore one
of the most isolated regions
of Arctic Canada.
A secluded marine bay
called Aimmatquttak,
or the Sherman Basin.
Using a repurposed
fishing boat,
she plans the first known
scientific study
of the waters here.
[Kristina] It's super exciting.
I mean, we couldn't even
navigate into the basin
without the help of elders
and the guidance
of the local community.
[Narrator] Inuk elder
Saul Aksalook Qirqniq
knows these waters
better than anyone.
[Kristina] I've come in to
collaborate with the community
and try to answer the questions
that they have.
[Crewmember] Come on over, Saul.
[Crewmember] Is this our
best way to come in?
Yeah, you can go straight there.
When I was a little boy,
we used to have
a winter camp over there.
[Crewmember] Oh, okay.
[Narrator] Generations of Inuit
have foraged and hunted
in the Sherman Basin.
It's an area that's sacred
to them, rich with life.
[Kristina] This project is
really unique in that it started
from questions that
the community had.
[Man] Look at all of them.
[Kristina] Why are there so many
fish in the region?
What makes the seals
so fat and so healthy?
What's living at the bottom
of the ocean?
[Narrator] To try and answer
these questions,
Kristina is joined
by Lorenza Kamimmalik
and Erwin Nuliayok Kihoak.
[Kristina] Having the youth
involved really provides
an important bridge from science
to the local community.
[Narrator] The team wants
to explore the seabed
to find out what
lives down there.
[Crewmember] Let it go on down.
[Narrator] This will be the
first time anyone has ever seen
the sea floor in this area.
[Crewmember]
Oh, there's the bottom.
[Kristina] Oh, wow.
[Narrator] It's full of life.
In total,
they document over 150
plant and animal species.
[Lorenza Kamimmalik] My
experience was pretty amazing.
There's a lot more that I would
want to learn about the ocean.
[Narrator] In Lorenza
and Erwin's lifetime,
it's predicted that
the Arctic could change
beyond all recognition.
[Erwin Nuliayok Kihoak]
Temperatures getting warmer,
summers getting longer.
Winter doesn't come that early.
[Narrator] As the climate
shifts around them,
being part
of grassroots science
will help the next generation
prepare for the future.
[Kristina] The Arctic is warming
at four times the rate
of the rest of the planet.
If we can understand how
the ecosystem might change,
we hopefully can bring
that information
back to the communities
so that they can continue
to thrive and be resilient.
[Narrator] With expeditions
spanning all five ocean basins,
following the Great Ocean
Conveyor Belt,
it's clear how each
is connected
by deep water currents.
But new science has revealed
just how little we know
about the deepest realms
of our ocean.
[Katy Croff Bell]
We've only seen about 0.001%
of the deep ocean, which covers
about two thirds of our planet.
Just imagine what we're gonna
find in the other 99.999%.
[Narrator] National Geographic
Explorer Dr. Katy Croff Bell
is setting out
to completely revolutionize
the future of deep sea
exploration.
[Katy] I am so excited about
what we're on the cusp
of right now.
[Narrator] She's created
a lightweight device,
a quarter the size of a lander,
that can reach depths
of nearly four miles.
And it's called DORIS,
the Deep Ocean Research
and Imaging System.
[Katy] I do think that DORIS is
gonna be a huge game changer.
A system like this--low cost,
but easy enough to use
just straight out of the box--
doesn't exist.
[Narrator] The simplicity
of the system will transform
who can explore the deep.
[Katy] We'll be able to deploy
in countries and communities
that have never, ever been
able to do so before.
Let's go.
[Narrator] Time to see what
this prototype is capable of.
[Katy] Oh, and there's
some kelp. Ooh, a fish!
This is huge--DORIS' first
deployment in open ocean.
It is working as it should.
[Narrator] Katy has huge plans
for this revolutionary
piece of technology.
[Katy] We're putting together
a set of 10,000 points,
and you can see how
distributed they are.
It will give us this much more
representative look
at the global deep sea floor.
We're hoping that hundreds,
thousands of these systems
will be out exploring the ocean
in the coming years.
[Narrator] Over the course
of three years,
the National Geographic
Explorer snapshot
of ocean health
reveals reasons
to be optimistic.
In the Southern Ocean,
the team's discoveries
will reinforce
the need to protect
Antarctica's pristine
deep waters.
In the Cook Islands,
Anya's super corals offer
a glimmer of hope
for reefs in a warming world.
And in the Pacific,
Kim is building AI models
based on the aerial surveys
to detect and understand
the krill swarms
feeding blue whales.
Together, these explorers
are revealing
how deeply connected
our seas truly are
in one vast ocean.