Expedition X: Atomic Sharks

When it comes to shark hotspots, we think of places

like Australia, the Caribbean, or Amity Island.

But it turns out the world's largest shark sanctuary is in

one of the most remote corners of the world in

the Marshall Islands.

Located deep in the Central Pacific,

this shark haven spans 750,000 square miles,

an area four times the size of California.

It safeguards 27 species of shark, hosting some of

the largest populations found anywhere in our oceans.

Now, you're probably asking yourself, what on earth does

this have to do with "Expedition X"?

And where the heck are Phil and Heather?

Well, the answer is this region has recently suffered from

a series of brutal shark attacks.

And now, the royal family of the Marshall Islands has asked

my team to urgently investigate,

because they're wondering something truly explosive --

whether these violent sharks could have been created

by the island's horrifying atomic history.

Off the coast of a paradise island, something hellish is

about to unfold.

A woman swimming with friends and her young son is suddenly

attacked by an apex predator.

A reef shark clamps its jaws around her leg, savaging her as

she struggles to break free.

Bleeding and terrified, she makes a desperate escape

back to the boat.

She's lucky to survive, but the shark has

left its mark.

This seemingly unprovoked attack is just the latest in

a growing number of incidents throughout

the Marshall Islands, a region where sharks

outnumber humans 25 to 1.

And it's not just strangely hostile reef sharks

that have locals worried.

Nurse sharks, long considered among the ocean's most docile

predators, are also now reportedly attacking people.

Locals are frightened, wondering something stunning --

could this terrifying shark behavior be a result of

the region's apocalyptic atomic history?

Between 1946 and 1958,

the US Military uses the Marshall Islands

as a nuclear weapons test site.

67 detonations unleash more than 100 megatons

of atomic fury -- a force equivalent

to nearly 7,000 Hiroshima bombs.

Tremendous yield resulted in a serious fallout situation at

Bikini and certain other atolls downwind from Ground Zero.

The isotopes left behind by the blasts continue to prove

deadly 80 years later, leaving much of the Marshall

Islands still unsafe for human occupation, and its waters as

some of the most radioactive on the planet.

Experts are concerned that this atomic aftermath could be

what's behind these unprovoked attacks.

They theorize that dangerous nuclear particles may have

entered the underwater food chain,

only to ultimately be consumed by the predators

at the very top.

Has radioactive fallout mutated these sharks to make them

more hostile to humans?

And now, new evidence is only feeding this theory.

This recent photograph appears to show a nurse shark missing

one of its two dorsal fins,

a rare physical abnormality that some scientists believe

could be linked to genetic mutations.

The authorities have asked for our help.

What is happening in these waters

and are the atomic bombs to blame?

Phil and Heather are journeying into the unknown to discover

whether the Pacific Ocean hides a real-life Godzilla.

Radioactive monster mutant sharks.

My team is already one day and 5,000 miles into

their epic journey to the Marshall Islands

to search for mutant sharks.

But they have a long way to go yet.

From Oahu, Hawaii, the team takes a five-hour flight

on the famous Island Hopper route,

traveling more than 2,000 miles deeper into the Pacific.

The water looks so blue and clear.

We made it to the Marshall Islands!

But Phil and Heather aren't on land for long.

They next set sail on the final leg of their journey,

a two-day voyage into the Marshallese waters,

where the atomic bombs were once dropped.

My intrepid adventurers, how's the trip going so far?

-Well, we're in it, Josh. - Yeah, we are.

It's been 72 hours of intense air and sea travel,

but we're finally out to one of the most remote places

on Earth, ready to investigate

these incredible rumors of the mutant shark.

I really can't believe we're actually about to get in

the water to hunt what's essentially

an underwater Godzilla.

Phil, not to be nitpicky, but an underwater Godzilla is

just Godzilla. He lives underwater.

OK, I'll look for him too.

But seriously, finding any evidence of these mutations

would be truly historic.

Shark mutation aside, there's no question that

radiation is still a huge and very dangerous issue here.

Many of these islands that we're sailing past are still so

damaged by nuclear fallout that we can't safely set foot

on them -- so much so that the US Military

has essentially forbidden access

70 years later. - Right.

I mean, the irony is that it's actually safer under

the water than on land.

The water acts as a radiation shield.

Safer from radiation, but maybe not from

radioactive sharks.

This is legitimately a very dangerous expedition.

Be safe out there and keep me posted, OK?

Oh, we'll be in touch, Gates.

To answer the question of whether the sharks in these

waters are mutants, we're joined on

our investigation by an international team of

scientists led by Luke Tipple.

Hey, guys.

All right, Luke, what are

we getting ourselves into out here?

Luke has taken us to Troy's Coral Head,

a shark-infested reef where local divers have recently

encountered the abnormally aggressive

reef and nurse sharks we came here to investigate.

This is a location that has reports of sharks displaying

potential mutations. There is a tawny nurse shark.

It's supposed to have two dorsal fins.

But locals have reported some of the individuals here missing

that second fin. -Right.

And there's also been reports of aggressive behavior.

I've done thousands of shark dives all over the world,

and the behavior they're reporting at this location is

something I've never seen before.

So hopefully we see it, but also hopefully we can be

the first to document it. -Absolutely, yeah.

I mean, that's the exciting thing about science, right?

You hear reports, now we get to go not only document it,

but actually sample the animals

and try to figure out what's going on.

Speaking of samples, how are we doing that?

We are going to use a spear gun.

Takes a little biopsy, pulls out of the animal,

and we store that biopsy and send it off to the lab.

So you're going to shoot a shark and take a little

tissue sample, and I imagine

that shark ain't gonna be happy.

The shark is not going to be happy with it.

Recently, a researcher actually got bit immediately after

taking a biopsy because the shark turned around and bit

him on the head.

So you're saying there's a chance that we could

be attacked? -They're real predators.

They bite with real teeth.

There is a non-zero potential of somebody getting bit,

so it's important to be safe. - OK.

Seems like it is time for us to suit up.

- Yes, sir -- let's do it. -Let's do it.

During our dive, we'll be searching for

reef and nurse sharks, the two species

reportedly at the center of these strange,

unprovoked attacks.

Our goal is to collect as many tissue samples as possible to

find out whether radiation exposure from nuclear testing

has altered these sharks' DNA, and if it's really turning them

into dangerous mutants.

These are the spear guns we're using.

Yep, this is for you.

We use the spear guns for two things.

So on the tip of this is our biopsy tip.

This is just a sharp tube that when we shoot it at the side of

the shark, it'll take out just a plug.

And that plug is the tissue sample that we send off

for DNA.

Second, we'll be putting satellite tags on the sharks in

the hopes that it leads us to the larger sharks off site

who might be displaying more of that territorial,

potentially dangerous, erratic behavior that's been reported.

OK.

And on a bit more of a serious note,

we don't want anyone to get hurt.

You know, we're dealing with sharks and depth and guns,

and all kinds of things could go wrong.

The nearest full-fledged medical facility is over

2,000 miles away in Hawaii. We don't want any accidents.

- Copy that. -Let's do this.

All right, masks on. All side-by-side.

Three, two, one, let's go!

We begin our initial descent and level off at 20 feet,

just above the coral head, a natural habitat for fish,

making it the perfect hunting grounds for sharks.

While the guys search for more sharks, I'm setting up

our Seeweed cam.

It works like an underwater trail camera.

Using artificial intelligence, it will continue scanning

the reef after we leave,

automatically taking photos of sharks it detects.

Hopefully, it captures evidence of the aggressive behavior

or physical mutations the locals have been reporting.

I think this is about the spot where the boys are.