Far out in the South Pacific, there s a
tropical island paradise. Lush rainforests

cover steep volcanic peaks, and vibrant coral
reefs hug the picture-perfect coastline.

It's a beautiful place.

Known as the Islands of Sacred Earth,
the territory of American Samoa is one of

the United States most remote outposts.
Samoa s 3,000-year-old culture is thought

to be Polynesia s oldest.

There's a song in American Samoa, they say
we are the people from the sun.

People here in American Samoa, they're very
good people. Friendly people.

We have such an intact traditional culture
here.

Here in the Pacific islands, coral reefs are
so integral to the culture. Every facet of

life in a Pacific island is touched by reefs
in some way.

The reefs in American Samoa are highly diverse.

We have over 250 known species of coral in
the territory.

Some of the largest coral is actually found
here, which is something very unique.

While coral reefs around the world are in
serious decline, American Samoa s reefs

have so far been relatively resilient in the
face of local and global stressors.

It's something that we continuously monitor
because that could change at any time. This

is almost like a living classroom that we
can come and study and then take that information

somewhere else that maybe is suffering more
quickly, so, we can learn a lot from here.

What makes the territory s coral reefs more
resilient than others? And how might this

help corals that are in decline elsewhere?

Major funding for this program was provided
by The Batchelor Foundation, encouraging people

to preserve and protect America's underwater
resources, and by The Arthur Vining Davis

Foundations, strengthening America's future
through education. Additional funding was

provided by The William J. & Tina Rosenberg
Foundation and by the Do Unto Others Trust.

Located halfway between Hawai i and New
Zealand, the U.S. territory of American Samoa

is home to America s only National Marine
Sanctuary and National Park south of the equator.

The National Marine Sanctuary of American
Samoa is located in the cradle of Polynesia s

oldest culture. It's about five hours south
of Hawai i by plane.

And it spans over 13,000 square miles, making
it one of the largest as well.

To better understand and protect the sanctuary s
spectacular coral reefs, Research Coordinator

Valerie Brown is implementing a monitoring
program to document the reefs condition

and any changes that might occur over time.

And to be able to provide a response if we
see some sort of acute impact. It's really

important, especially as reefs are changing
so quickly, to be able to adaptively manage

the reef ecosystem and protected areas.

Scientists conduct monthly surveys on the
reefs in the sanctuary areas around the territory s

main island, Tutuila.

And when we're doing that, we're being pulled
behind the boat on towboards.

So we're looking for coral bleaching, coral
disease, crown-of-thorns starfish or snail

predation, and marine debris.

Each year, the sanctuary science team also
conducts in-depth surveys of the reef along

predetermined transect lines.

Hanae, she's looking at coral species, their
size and also their health for each of the

corals within quadrats in each of our transects.
While she's doing that, I am taking benthic

quadrat photos. So we are getting photographic
documentation of the bottom and then we're

able to post-process that and look at coral
cover, algae cover, and that gives us a really

good understanding of what's happening with
the coral communities and the overall reef

health. So, are there changes in algae, changes
in coral, changes in the size structure of

the coral community?

In addition, Valerie is taking hundreds of
photos of the reef that can later be stitched

together into a large photo mosaic.

And that gives us a 3D model of the reef that
we're hopefully going to be able to use to

assess structural complexity and then look
for changes over time.

And the monitoring program doesn t just
rely on visual data. In the remote and pristine

Fagatele Bay the experts installed an ecological
acoustic recorder that captures the soundscape

of the reef.

What this does is it captures all the noises
on the reef 24 hours a day. Similar to walking

into a forest and you hear birds, if you dive
into a reef, you should hear shrimp and fish,

all making noise, there's snapping and there's
grunting. The noises on a reef can really

tell you a lot about whether it's healthy
or whether it's impacted. It can also tell

us if there's vessels coming into the reef.
And so having that information will improve

our ability to manage reefs and to understand
some of the things that are happening when

we're not there.

Just how valuable it is to monitor changes
on a reef over time is evident in the village

of A a, across from the Pago Pago Harbor.

The A a transect is actually the longest
coral reef survey transect that's resurveyed

in the world. So it's a really exciting thing
for the territory. And in 1917, Alfred Mayor

set this transect up and we've monitored it
ever since.

It's something that we are proud of because
it's right in our village. We're trying to

preserve this coral here because it's very
important.

It's 247 meters long, this transect, and it
runs from the shore to the crest. So it's

a huge area of this reef flat.

Since Alfred Mayor first started his monitoring,
this reef flat has been impacted by a variety

of stressors.

After World War II, the harbor had a significant
increase in development. We had two canneries

come in, we had dredging happening. We had
different sedimentation and pollution. We

can track those changes in those coral reef
communities. And we didn't see any recovery

after that for about forty years.

With the environmental regulation they started
diverting the pipes away, the wastewater,

more out the harbor. So by 1990, we started
to see the recovery of the reef and that's

a good sign that our efforts to manage our
water quality is working.

Switching from septic tanks to municipal sewer
lines will further improve the water quality

in the bay.

When I became a representative almost fourteen
years ago, one of my goals is to have a sewer

line for this village, never was before. Now,
half of my village is already functioning

on the sewer line and we're going to finish.
The coral is very, very dear to my heart.

The Coral Reef Advisory Group, a collaboration
of seven local agencies, is working closely

with the A a village and village council
to protect and restore the reef.

This village is well known for the warriors
in the old days.

We're going to work together on coral restoration.

I like to see a healthy coral reef. I love
this village. That's why I try to do the best

for our village.

Samoans have their own creation story of a
God they believe in, Tagaloa-lagi was his

name. People were actually asked by Tagaloa
to really take care of these special places,

the ocean, because these places will sustain
them throughout their livelihood. And the

Samoan people are very much dependent on the
ocean for their food source.

There are a number of reasons why reefs may
be doing better in American Samoa than elsewhere.

The islands are far removed from any other
landmass, and there is minimal industry or

tourism.

We don't have much major development in the
territory. All land is protected through our

land tenure system, which are the matais,
chiefs of the family, who are caretaker.

Lands on island are not for sale. Lands are
assigned to family members to build their

homes or cultivate.

So that's sort of protected, you know, these
lands from outsiders and all the development.

So that help minimize direct impact from land
to sea.

While local managers can t control the global
stressors caused by climate change, they can

help reduce localized impacts that harm the
coral reefs.

Things like pollution coming from villages,
sewage that's not being managed properly,

illegal dumping that may be getting into the
ocean. And then also managing the watersheds

above the coral reefs, which we find is a
huge contributor to stressors.

So that when things on a global scale, like,
you know, rising sea temperatures or sea level

or the frequency of cyclones, increases, they're
in a better position to protect themselves

from that.

Thriving reefs aren t American Samoa s
only claim to fame. The territory is also

home to some of the world s largest documented
corals, found in the waters off Ta , about

70 miles east of Tutuila.

It's also known as the Valley of the Giants.

In 1995 scientists described the first famous
coral colony, which is located inside the

National Marine Sanctuary.

It is recorded to be around 500 years old.
It's also known as Big Momma.

This is a very large, massive porites colony
that is about 23 feet tall and 135 feet around.

When you're up next to it, it kind of dwarfs
you. It's as big as a house almost. And so

it s just spectacular.

It's made it through these bleaching events
recently and overall it's in really good shape.

And it turns out Big Momma isn t the only
large coral in the Valley of the Giants.

Recently the National Marine Sanctuary, along
with the National Park Service and the local

agencies through the Coral Reef Advisory Group,
conducted a survey around Ta to look

for other large corals. And so we towed all
around the western, north and eastern sides

of Ta and documented all of the large
corals there. Every time they saw a coral

that met the specifications of over two meters
across they would then notify people on the

boat to take a waypoint so we were able to
map all these very large porites colonies.

What's really exciting is our study revealed
that we have several hundred colonies that

are over six, seven feet in diameter.

While measuring some of these large corals
in the fall of 2019, the research team documented

a coral head inside the National Park of American
Samoa that is even larger than Big Momma.

That coral is about 26 feet high, about 226
feet around, and is quite spectacular.

It was phenomenal. It's incredibly healthy.
It s like nothing I've ever seen before.

So this now makes this the largest coral that
we have in the territory and one of the largest

corals in the world. This is something that
is extraordinary in science, these corals

are really slow growing. So this genus grows
potentially one centimeter in a year.

It really makes me feel, you know, proud of
our islands. We're trying to find where is

that uniqueness from, why, why our islands?

The same species of porites coral is also
found in the nearby Ofu pools. This stunningly

beautiful shallow lagoon provides scientists
with a living laboratory to study the impacts

of rising water temperatures on corals.

It doesn't seem to bleach as often as other
reefs around the world are doing.

Those reefs can see changes of up to six degrees
Celsius in a day. So those corals have had

to adapt to such significant changes in temperature.
And it takes just one degree Celsius change

in that temperature for a week to induce the
stress response that we refer to as bleaching.

Coral bleaching happens when water temperatures
are too high and corals expel the symbiotic

algae living in their tissues. These algae
make up about 90 percent of a coral s food

source, and without them the corals eventually
starve.

They can survive like this for a short period
of time. If the temperatures don't come back

to the normal level, that's when you start
seeing mortality.

The reef in Ofu actually gets cut off from
the rest of the ocean at low tide. And so

there is a theory that we've contemplated
for years that the reef has evolved over time

to be better suited to warmer water. And maybe
that's why it's more resilient.

Record high temperatures between 2015 and
2017 led to severe bleaching on reefs across

the Pacific Ocean, including in American Samoa.
In many places large swaths of centuries old

reefs were lost.

We definitely did a lot better and didn't
have as much mortality following that.

What's so special about the reefs here in
American Samoa that they're able to recover

from repeated coral bleaching and other threats?

By looking at those resilient reefs, we can
determine better what species might be more

suited for things like transplantation or
other things that managers could do in the

future to help coral reefs survive.

Rising temperatures are just one of several
climate change-related impacts that are threatening

coral reefs worldwide. Climate change is caused
by increased levels of atmospheric carbon-dioxide,

or CO , brought on primarily by the burning
of fossil fuels.

Concentrations of CO in the atmosphere
are continuously measured at four remote U.S.

atmospheric baseline observatories, including
one in American Samoa.

The oldest one is on the slopes of Mauna Loa.
That was founded in 1958, with the South Pole

a couple months later. And then our other
sister station up in Barrow, Alaska, in 1973

and then finally American Samoa in 1974. We
measure over 60 different chemical compounds.

Everything from ones you hear every day, like
carbon dioxide in the atmosphere to the ozone

layer, to hydrocarbons, to CFCs, to oxygen
and nitrogen in the atmosphere.

When CO concentrations were first recorded
in 1958, the average level of atmospheric

CO was 315 parts per million. Since then,
levels are increasing more rapidly than ever

before in earth s history.

Last year the average was 412 parts per million.
So it has been going up rather quickly.

The data collected at the observatories is
sent to a home base in Boulder, Colorado,

where it s analyzed.

I take weekly glass flasks for the Carbon
Cycle Group here. They measure the CO in

the atmosphere. They have a machine here that
measures it 24/7, 365 days a week. But we

still want to take these glass samples, these
flasks, that I send back to Boulder weekly

so they can measure them there, make sure
the machine has given right numbers and then

they can use more sensitive instruments they
have out there as well to get a more precise

reading.

As levels of carbon-dioxide increase in the
atmosphere, the oceans also take up more CO .

It makes the oceans more acidic because the
ocean absorbs that carbon dioxide and makes

carbonic acid. And that's really bad news
for corals and other organisms that secrete

shells that are made out of calcium carbonate
because it makes it harder for them to create

their shells and their skeletons. The reefs
in American Samoa are helping to block storm

waves and tsunami waves that impact the shoreline.
And so with ocean acidification, if corals

slow down their growth, then they're not going
to be able to keep up with sea level rise

and that protective value is going to decline.
And that's going to have big impacts for the

human communities here on the island.

To measure acidity levels in local waters,
the NOAA Ocean Acidification Program teamed

up with the National Marine Sanctuary and
other agencies in 2019 and installed a monitoring

buoy in Fagatele Bay.

And that's going to give us real time monitoring
of key parameters of ocean acidification over

time. American Samoa has the highest aragonite
saturation levels measured in any of the 48

islands that are monitored through the National
Coral Reef Monitoring Program in the Pacific.

That Aragonite is what is used by these organisms
to build their skeletons. Having that readily

available may mean that they're just able
to battle some of these impacts a little bit

better cause they don't have to spend as much
energy building their skeletons. I think having

the MAPCO2 buoy here is going to help understand
some of those processes better. Coupled with

the biological data that we're collecting
and the acoustic data that we're collecting,

it should allow us to have a really robust
picture, say in a decade, by putting all of

that together and looking at whether there
are changes in the coral communities, in the

sound profiles, as we see changes in pH and
carbon dioxide chemistry in the water in Fagatele.

I don't want to paint too rosy of a picture.
The reefs here are doing relatively well,

but all of that could change very quickly.

While the coral reefs in American Samoa have
so far proven more resilient than others to

coral bleaching and ocean acidification, parts
of the island territory are already feeling

the effects of another climate change impact
sea level rise. Over the last decade sea

levels have risen by more than seven inches,
affecting the residents of Aunu u, a

small island just a short ferry ride away
from Tutuila.

It's beautiful. It really is peaceful, and
you know, the people are nice. Everyone's,

you know, welcoming.

Aunu u is at the forefront of all the
climate change impacts in American Samoa.

The sea level rise is very obvious here.

(foreign language) Our water well is now both
saltwater and freshwater mixed together. It

has more of a salty taste than freshwater.

At certain times waves wash over the roads
and erode the shoreline as well as flood the

power plant on the southwestern side of the
island.

(foreign language) We have now started constructing
seawalls on the side where the power plant

is and hopefully can hold off the intrusion
of waves and saltwater from also entering

our taro plantation.

Aunu u is famous for its taro.

In my opinion, not just me though, Aunu u,
it has the best taro anywhere in the Pacific.

Taro is a type of starch. You would compare
it to yams, and it's a source of food as well

as income.

In recent years, saltwater has been seeping
into the fields from below. Local islander

Sinalei Ta ala is researching the problem.

Some of the local farmers that I've talked
to, they've known for quite a long while that

the saltwater's in the water. So I found like
a measurement of salinity about two to six

parts per thousand. And so I fear that sometime
in the future, you know, the sea level is

still rising, so it's going to be like a bigger
problem because the taro cannot grow in salt

water. I've planned to stay here for the rest
of my life, but, like, it looks like that's

not going to be possible in maybe 20 years,
and, yeah, it is nerve wracking to think of,

you know, my home being gone sometime in the
future, submerged in water because there is

no place like home, and I don't want to leave.

It is real and it is happening, and time is
running out. So for families in the South

Pacific, it's just very, very important that
the rest of the world knows what we're going

through and what our children will have to
go through. It's gonna impact so much more

than just our shorelines. A whole way of life
is at stake.

We have an obligation to protect these areas,
not only for the environment, but also for

the people that need these areas to survive.

Part of our job with the sanctuary is to try
to make sure that those reefs are as resilient

and healthy as possible, not just to protect
the biodiversity and the reefs themselves,

but also to protect those communities that
are so vulnerable to climate change impacts

and sea level rise.

Coral reefs are integral part of life on the
islands. It protects our shoreline, but also

provide food for our families. Coral reef
are part of our rich culture and tradition.

Fa asamoa, or the Samoan way of living,
values respect, because we believe that God

gave us the resource to protect and to use
properly.

And our hope is that we continue to protect
the marine ecosystem for both current and

future generation.

Major funding for this program was provided
by The Batchelor Foundation, encouraging people

to preserve and protect America's underwater
resources, and by The Arthur Vining Davis

Foundations, strengthening America's future
through education. Additional funding was

provided by The William J. & Tina Rosenberg
Foundation and by the Do Unto Others Trust.