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NARRATOR: The great white shark, iconic apex predator.

Official YIFY movies site: YTS.MX

Long seen as the lone wolf of the ocean, until now.

Sharks of all species are being spotted in gangs

across the globe.

Leaving experts determined to uncover what’s behind

this shark gang phenomenon.

CHRIS: We’re finding that they’re far more social than we’ve ever thought.

NARRATOR: Is it for protection?

MATT: We have twelve bull sharks, circling around the cage

NARRATOR: Migration?

MATT: You can start to really see the hierarchy of these sharks

NARRATOR: Or even to hunt in a pack?

YANNIS: If these animals hunt in a group,

everybody’s success goes up.

NARRATOR: Are these predators joining forces,

to dominate the deep?

NARRATOR: Off the coast of North Carolina,

lies a treacherous stretch of water with strong currents and shifting sands.

With the remains of up to 5,000 ships,

it’s known as the graveyard of the Atlantic.

Hidden within this eerie resting place for lost souls

are gangs of sand tiger sharks.

Photographer and conservationist,

Tanya Houppermans, has spent over a decade documenting

the shark gang phenomenon occurring here.

TANYA (off-screen): I started diving around 2009.

Came down here to North Carolina and that was

the first time that I saw the sand tiger sharks.

It literally changed my life.

I walked into work and quit,

left the cooperate world behind

and decided to devote my life to spending time with sharks.

NARRATOR: Working with Spot a Shark USA,

Tanya is studying the thousands of sharks that have

made these shipwrecks their home.

These rusting hulks provide the perfect conditions for

marine life to grow, and for predators to hunt.

But why sand tiger sharks congregate here in such

large gangs is still a mystery.

TANYA (off-screen): There are times that we could see 100 and maybe even

more sharks in an aggregation.

They really seem to prefer to be around other sand tiger sharks.

We're not quite sure why yet.

NARRATOR: Today, Tanya and her husband Scott,

are looking for answers by diving a wreck known for

large groups of sand tiger sharks.

TANYA: Today we're heading out to the wreck of the Carib Sea.

This is a freighter that was sunk by a

U-boat during World War II.

Right now, she lives about 90 feet underwater.

That's where we tend to see

a lot of sand tiger sharks hanging out.

NARRATOR: Tanya is on the front line,

trying to discover the secret that unites theses sharks.

She’s taking photographs,

so scientists can study them for vital clues.

TANYA: Inside this housing is the camera that I use to

photograph the sharks and we have two lasers here on each side.

When I take a picture of a shark,

these two green dots will show up on the side of the shark.

We can then actually calculate the length of that shark,

just from the photograph itself.

Then we can go in and identify each individual shark based on

its unique spot patterns.

It’s like fingerprint is to a person.

We can kind of give each other’s gear a look over too.

Alright, looks good.

Every dive there’s the possibility of learning

something new about these animals.

There’s really hasn’t been a lot of research done on them.

You know, compared to a lot of other species such as great whites.

So anytime we can get the water with them and bring back

any information for the researchers that I work with.

It's great day.

You good babe?

Alright. Let's go find some sharks.

(oxygen tank hissing)

TANYA (over radio): We have 100 feet of visibility;

clear blue water.

(oxygen tank hissing)

A lot of the wreck is still intact.

You can see the big bow structure.

It never gets old.

There are just sharks as far as I can see, all around me.

NARRATOR: These sharks are named after tigers,

because of their voracious appetite,

but to Tanya they’re gentle giants.

TANYA (over radio): They have these raggedy teeth

that makes them look really fierce,

but these sharks are full of personality.

Sand tiger sharks are probably about six or seven feet.

With the females being a little bit bigger than the males.

NARRATOR: Surrounded by a swarm of sharks,

Tanya begins her search for evidence,

as to why so many are here.

(oxygen tank hissing)

TANYA (over radio): There are a lot of females.

Every so often you see a few males, but it’s mostly females.

Why is that?

NARRATOR: With her laser guided camera Tanya captures

her first clue to solving this mystery.

TANYA (over radio): Some of the females do have scars from mating.

When the sharks mate, the male actually holds onto

the female with his teeth.

If we see fresh mating scars that female may be pregnant.

We’re finding several pregnant females.

Why are they grouping together?

NARRATOR: After photographing the girl gang.

TANYA: That was amazing. There was a lot of sharks.

NARRATOR: Tanya tries to make sense of this incredible spectacle.

TANYA: So what we're seeing is a big gang of

sand tiger sharks, um, mostly females.

We have so many unanswered questions,

but what we’re thinking is that maybe these females are

aggregating together during pregnancy,

so that the males don’t try to mate with them again.

TANYA (off-screen): It could be possible that the females are kind of banding together,

as kind of a support network.

They are choosing to group together like this.

And so not all sharks are just solo predators,

sharks could have a social life just like humans.

NARRATOR: Tanya’s observation that female sand tiger sharks

could form gangs for protection from males,

is one explanation.

But is this the case, for all species of shark?

Just off the coast of California’s busiest beaches,

(yelling)

gangs of great whites lurk in the shallows.

Increasing numbers of wounded seals are washing ashore.

And the news unsettles the locals.

REPORT (over TV): A pilot reported seeing the adult sharks.

All three, 10-12 feet long about 150 feet away from the surf zone.

MAN: If I go out and see a swarm then I’m right back out.

NARRATOR: Shark expert Dr. Chris Lowe,

and his team from the world-famous Shark Lab,

are here to get to the bottom of this escalating situation.

CHRIS (off-screen): When we talk to a lot of the locals,

many of them are shocked to find out that there are

so many great whites off their beaches.

When these sharks first started showing up the

lifeguards would go out with jet skis and

try to drive them off the beach.

And it was actually comical to watch,

because the sharks were completely unfazed.

Now what that tells me, as a scientist is,

they really like this habitat.

NARRATOR: To ease local tensions,

Chris and his team are determined to find out why

these great whites are forming gangs here.

CHRIS (off-screen): Our main goal is to try to figure out

why they picked this beach?

And why are they together?

Most people consider sharks this individual, solitary predator, right?

Always by itself looking for its prey.

That isn’t what we’re finding to be the case.

NARRATOR: Today the Shark Lab team is on a mission to

tag great whites in the area.

CHRIS: We’ve got tagging stuff for tagging?

JAMES: Yep. I think we’re all good.

NARRATOR: They use tags to monitor the number of sharks

and their position off the beach.

The team hopes the data will provide clues as to why these

great whites are here in such large groups.

CHRIS: We can go out each year, during shark season,

which is that time between April and about October,

and then try to locate sharks and tag them.

By tagging them and tracking them we know what

they are doing all the time.

CHRIS (over radio): Beach team, Beach team.

This is the whaler, do you copy?

JACK (over radio): Yes go ahead.

CHRIS (over radio): Put the bird in the sky.

See what you can see.

CHRIS (off-screen): Five ago, we wouldn’t be able to do what we are doing now.

Technology has completely changed how we study group behavior in sharks.

We use the drones to spot for us.

They give us a bird’s eye view of what animals are doing,

when they don’t know we’re watching.

It’s the ultimate spy technology.

JACK: I’ve got eyes on it

CHRIS (over radio): Alright I’m headed to your location.

JACK: It’s 7 o’clock, about 50 meters. I’ll try to get eyes on the shark again

EMILY: Oh there they are!

JACK: You’re right on it.

It’s right on the drone.

CHRIS: The drones tell us where the shark is and then if

we are very stealthy we can dart the transmitter

into the shark’s’ back.

JAMES: I’m going to rig up a tag.

Uh, okay, the ID number is 4342.

CHRIS: The tags they’re communicating with acoustic receivers all along the shore.

So, every time one of those tagged sharks gets within

about 300 yards, the receiver logs the time,

the date and the ID number of that shark.

NARRATOR: These harmless tags drop off after two years,

but attaching them to a great white is the tricky part.

CHRIS: We’re going to attempt to tag now.

JACK (over radio): Copy.

CHRIS: Alright James, here’s your weapon.

NARRATOR: Not only are great whites the largest predatory shark on earth,

weighing up to 5,000 pounds.

JAMES: Alright Emily, let’s go for the approach.

NARRATOR: These torpedo shaped predators are also lightening quick.

EMILY: Oh God. Yeah, it’s, it's there.

JACK: Alright it’s going to be at your 1:00,

about 400 meters.

It’s heading North.

CHRIS: Coming, coming around the back.

JAMES: I see it, I see it. Coming across the bow.

EMILY: Oh, it’s spooked. It’s coming around this way.

Okay, 12:00. Like 15 feet in front.

CHRIS: Getting a good position on the shark is really critical.

EMILY: Just there. Coming around. Just there.

JAMES: Tag away!

Got it!

NARRATOR: With another great white tagged,

the team is one step closer to tracking the movements of

the whole shark gang.

But to monitor how many sharks congregate here,

Marine biology student, Emily Spurgeon,

performs a job that’s not for everyone.

CHRIS: Okay and you two are diving.

EMILY: Yep. CHRIS: Alright.

Watch your back.

NARRATOR: She must dive into these shark filled waters to

collect a receiver that’s tracking great whites in the area.

Low water visibility makes this dive riskier than usual,

as Emily will be unable to spot the predators

until they’re up close.

EMILY: There are sharks in this area and that is

something we have to be mindful of when we dive.

If I did run into a shark while we were diving,

James and I we would probably go back-to-back,

so we could keep eyes on all sides.

If the shark knows we’re watching it,

it might swim off.

JAMES: Alright. On three.

EMILY: Yeah. JAMES: One. Two. Three.

(oxygen tank hissing)

EMILY (off-screen): The visibility is not great,

it’s half a foot to a foot.

There could be sharks 10 feet away from us we just don’t see them.

What was that?

♪ ♪

(rapid heartbeats)

NARRATOR: Marine Biologist, Emily Spurgeon,

is diving in low visibility water to swap out a receiver,

which monitors great whites off the coast of California.

But she’s not alone.

EMILY (over radio): There could be sharks 10 feet away from us

we just don’t see them.

(oxygen tank hissing)

What was that?

I can’t get it.

I got it.

EMILY: Got it.

NARRATOR: Dr. Chris Lowe immediately hooks up

the receiver to his laptop.

CHRIS: Okay the light is flashing, it should be connecting.

NARRATOR: He’s hoping the data from the tags reveals exactly

how many sharks are infiltrating these

coastal waters and more importantly, why?

CHRIS: Alright, let’s see what we’ve got.

EMILY: Just in the last two weeks,

we’ve had over 14,000 detections.

CHRIS: Nice!

EMILY: And the most recent detection.

10:36, that’s when we were in the water.

CHRIS: And a shark just has to be within 400 yards.

EMILY: Yeah. CHRIS: To get a detection.

CHRIS: Very cool. EMILY: Yeah.

CHRIS: Alright, so let’s see how many sharks.

EMILY: Let’s see, one, two, three, four, five.

13 sharks just at this station.

CHRIS: Wow, Okay! EMILY: Yeah.

NARRATOR: Excited by the size of this shark gang,

Chris now tries to solve the mystery of why they’re here.

CHRIS: Some of these individuals have been residing here,

for long periods of time.

These animals are showing fidelity to this area.

CHRIS (off-screen): Maybe its food abundance.

The sand is covered with sting rays here.

These are the number one thing that these young sharks like to eat.

But what’s the advantage of being in a group?

We don’t know yet.

NARRATOR: As Chris’ team investigates whether food is

the reason that sharks form gangs,

other scientists explore the idea that sharks

enjoy hanging out, as friends.

A collection of 700 islands and keys,

the Bahamas is not only paradise but the shark capital of the world.

This marine habitat is a protected sanctuary,

for over 40 species of sharks.

In the secluded mangroves of North Bimini.

Marine biologist, Dr. Félice Dhellemmes

and researcher Chessie Mason,

of the Bimini Shark Lab,

are tracking down a missing school of sharks that are

vital to their research into the shark gang phenomenon.

FÉLICIE: So were you here during the hurricane?

CHESSIE: Yeah, I was and it was actually kind of crazy.

All of this sand bank was completely exposed and

since it’s completely changed.

NARRATOR: In 2019 Hurricane Dorian swept through

the Bahamas with intense ferocity.

(whirling wind)

Devastating it’s mangroves and displacing gangs of sharks.

CHESSIE: I’m kind of worried if we’re gonna even find juvenile lemon sharks.

FÉLICIE: If the water was gone,

they probably had to go somewhere else.

CHESSIE: Yeah, maybe deeper water.

FÉLICIE: I’m hoping that they manage to find their way back

to the safety of the mangrove.

Lemon sharks are being threatened worldwide,

because the mangrove habitats,

in which they are born and grow, are being destroyed.

So, I’m going to pull into those mangroves.

CHESSIE: I can go up to the front and

see if I can see anything.

Fel, I think I’ve got a lemon.

FÉLICIE: You sure it’s a lemon?

CHESSIE: Yeah, I think so. FÉLICIE: Oh my God, yes!

I can see it to.

NARRATOR: Female lemon sharks come to these mangroves each

year to give birth, often to as many as 17 pups in one litter.

Left to fend for themselves, the babies group together for

protection in the dense roots and shallow waters.

Giving them extra cover from predators and

even cannibal lemon sharks.

It’s a tough start in life,

when your own species is out to get you!

CHESSIE: Lemon Sharks are called lemon sharks,

because they have this yellowish coloration.

They’re quite small when they’re juveniles,

but they’re incredibly agile and they are actually able

to turn almost 360 degrees on the spot.

NARRATOR: Félicie and Chessie must enter the mangroves on foot.

CHESSIE: Let’s get in!

NARRATOR: To investigate whether or not this is a

lone lemon shark, or a member of gang.

CHESSIE: Can you see something?

FÉLICIE: Could they be in there?

CHESSIE: They just move so quickly.

NARRATOR: Lemon sharks’ yellow skin provides the perfect camouflage in sandy water,

so spotting them is never easy.

FÉLICIE: I’m really hoping we can find a group today.

Lemon sharks are absolutely perfect for research,

because they hang out in such big groups normally.

I’m interested in whether or not sharks are always social or not.

If some of them are more social than others.

See this might be a good place.

That looks very similar to every other hang out spot I’ve ever seen.

Oh, I think I see one!

CHESSIE: Oh wait straight ahead there?

I think you’re right!

FÉLICIE: It’s a lemon! It’s a lemon! Oh my God.

Here they are.

NARRATOR: In the Bahamas, marine biologist

Dr. Félicie Dhellemmes and

researcher Chessie Mason have found a missing gang of lemon sharks.

FÉLICIE: Oh my God. Here they are.

NARRATOR: Displaced by a recent hurricane.

FÉLICIE: Oh, what a relief,

because we didn’t think we’d find one.

It’s really, really great news that at least one group is

healthy and is using the mangroves again.

Oh, here is a baby!

CHESSIE: Oh!

FÉLICIE: Oh my God, it’s so cute!

Lemon sharks when they are this age are just the

most adorable thing in the world.

Their little fins are just perfect.

They are kind of funny the way they swim.

I love them.

CHESSIE: How many can you count.

FÉLICIE: I think there’s a least five here.

NARRATOR: Like their great white cousins,

lemon sharks form gangs from birth for protection,

but that’s not the only reason.

These sharks seem to enjoy each other’s company.

CHESSIE: You see those two?

FÉLICIE: Yeah, they keep on coming together.

CHESSIE: Yeah, really cool.

FÉLICIE: They’re almost holding fins.

Sharks are social and we’ve found them to stick together

and to really have favorite buddies, at least at this age.

Ah look at him! Hi!

Hi, what’s up my man.

During my research I’ve seen lemon sharks be social in captivity,

but it’s really cool to see that happening in the wild.

CHESSIE: It’s honestly amazing.

FÉLICIE: I think when most people think about sharks they

are thinking about a mindless killer,

but those sharks have personalities and

even have a social structure that’s quite complex.

NARRATOR: Though Félicie’s research suggests that lemon sharks form friendships,

the Bimini Shark Lab team is unsure whether

these social bonds exist amongst bigger predators.

Each winter, great hammerheads migrate to Bimini,

to prey on bountiful fish and rays.

These imposing giants can grow up to 20 feet long.

The head of Bimini Shark Lab, Matt Smukall and his team,

has been studying the social dynamics of these

great hammerheads for almost a decade.

MATT (off-screen): Great hammerheads can cover thousands of miles each year

and we're right along one of their known migration routes.

It's such a special opportunity to spend time in

the water with the same individuals year after year,

and you can almost get to know their different personalities.

NARRATOR: Today, Matt and his team prepare to dive with

these giants of the ocean, to learn if they form gangs,

and how they get along.

MATT: So, we're out at the, uh, hammerhead site.

Since these are fairly elusive and

critically endangered sharks,

we're gonna use the bait to keep them around and

actually observe some of the different behaviors.

FÉLICIE: I'm gonna get that tube of bait in the water.

That will start attracting some hammerheads.

There's already quite a few nurse sharks here.

MATT: Obviously, when we have bait in the water,

it's not just hammerheads that might show up.

At this dive site we have a lot of nurse sharks, bull sharks.

So, you always just have to be paying attention to

the number of sharks you have.

Checking around us, watch our back.

We’ll have comms down there,

if you want to relay anything to us.

And then, we’ll also let you know how things are going.

FÉLICIE: Alright, sounds good.

There’s a hammerhead right here, we've got our first one guys!

CHESSIE: Oh, nice.

NARRATOR: Great hammerheads are supersized hunting machines,

so getting in the water with them takes courage.

MATT: The great hammerheads are one of the biggest sharks

we have in Bimini, they’re really what you would

classify as an apex predator.

They're designed to hunt down prey.

They’re just extremely powerful and can potentially weigh close to a 1,000 pounds.

That's just pure muscle.

NARRATOR: Hammerheads are not only big and strong,

they can swim four times faster than an Olympic swimmer.

MATT (off-screen): When these hammerheads want to move,

even though they look big, they’re super agile.

They are just extremely quick,

they can potentially move up to 20 miles an hour.

The positioning of those eyes on the outside of that

big head gives them a better field of view.

So, they are the ones that are going to be able to chase down

sting rays, eagle rays, even smaller sharks.

NARRATOR: Surrounded by predators eager for a free meal.

FÉLICIE: You should get ready. CHESSIE: Yeah, on it.

NARRATOR: The team put on their scuba gear,

throw in the bait box and brave the water.

FÉLICIE: Alright guys, Good luck. All clear.

And they’re off!

MATT: This is amazing down here. We have great visibility

CHESSIE: We’re surrounded by three different species of shark

FÉLICIE: There’s those nurse sharks, there’s bull sharks.

Those great hammerheads.

It's kind of like you're in an underwater Safari.

CHESSIE: Matt, I think that I can ID the great hammerhead

I think it’s Scylla. You can tell from her dorsal fin

FÉLICIE (off-screen): We’ve been studying those great hammerheads for many years.

And we needed to be able to identify them and recognize them,

so we’ve started naming them after

Greek Goddess and Gods.

MATT: Now it looks like we have a second one coming in

This looks a little bit bigger

Yeah, I think that’s Amphitrite

FÉLICIE: There she is! That’s my girl Amphitrite.

Behaviorally you can tell that’s her,

because she’s just up in your face.

She’s the leader out there.

She’s going to get the food reward.

NARRATOR: Now that Matt is center of attention,

he can study how these sharks interact with each other.

MATT: When we're feeding the hammerheads,

we have to pay attention to those sharp teeth

That's ultimately what's probably going to injure you

They're just so big, so powerful

In most places around the world

you're lucky to maybe see one or two great hammerheads on a dive

We have Amphitrite here

Scylla

Tethys

and I think Gaia just passed by in the back

FÉLICIE: The whole gang has turned up now.

FÉLICIE: I'm going to gear up and get into the water now

MATT: Yeah, I think it’s kind of unfair, you know, we’re down here having all the fun

NARRATOR: During feeding time, Matt discovers a pecking order

between the species of shark.

MATT: Having all these different species in the water

you can start to really see the hierarchy of these sharks

The nurse sharks are just lying on the bottom looking for the scraps

Bull sharks are just hanging around on the perimeter

Big, powerful hammerheads are kind of the ones dominating the dive site

CHESSIE: Hammerhead just came in

MATT: I've never seen her in Bimini before

Look how enormous she is. Just the girth

She has to be around 13 to 14 feet

FÉLICIE: Oh my God. This must be the biggest hammerhead I've ever seen.

NARRATOR: In the Bahamas, the Shark Lab team is

diving deep on the ocean floor.

To observe the social interactions of migrating hammerheads.

MATT: Just have a new hammerhead

NARRATOR: Out of the blue, a new gang member appears.

FÉLICIE: Oh my God. This must be the biggest hammerhead I've ever seen

There she comes again, guys

For a shark that size, we're going to have to give her a really good name

We should call this one Maia, for the Goddess of mountains

MATT: She’s huge, but she’s a bit shy

FÉLICIE: Yeah, she hasn't been very close to us

She seems like she's not really familiar with the setup, she's figuring it out

MATT: Yeah, the other sharks are a lot more bold and they know what's going on

FÉLICIE: She disappeared into the blue

MATT: It was an awesome dive. Let’s head to the surface

CHESSIE: That was awesome.

There’s nothing like being in the water

with great hammerhead sharks.

NARRATOR: Onboard, the team discuss their latest discovery,

that these hammerheads may be far more social than expected.

MATT: As the behavior expert,

what did you think of down there?

FÉLICIE: Oh, I thought that was really, really fascinating.

There is obviously a hierarchy between the different groups of sharks.

And the difference between those great hammerheads

is really stunning.

Really, there's some, they're super bold about it,

and others that are a bit more shy.

MATT: Being able to spend multiple years in a row with

the same individuals is where you really start to get to

understand their individual personality and

start to respect the fact that within that group

there might be a hierarchy.

NARRATOR: Scientists previously thought that social hierarchy

amongst sharks was strictly based on size,

but the behavior of this gigantic,

14-foot hammerhead, now challenges this theory.

MATT (off-screen): She's the biggest hammerhead that we've had in Bimini to date.

But even though she's massive, she's actually a bit timid.

She's not just throwing her weight around.

She's coming in trying to figure out

her positioning in this group.

It really makes you understand that it's not

always the size of the shark in the fight,

but really a lot of times the size of the fight in that shark.

How bold they are and how much they're driven to want to be

the leader of that group.

NARRATOR: The Shark Lab’s pioneering research suggests

that sharks are far more social than previously thought.

But here, in Florida, there are scientists who believe

that sharks form gangs for more than just friendship.

Shark behavioral expert, Dr. Yannis Papastamatiou,

is at one of the world’s most spectacular natural events,

the Mullet Run.

Searching for evidence that sharks form gangs to

strengthen their hunting skills.

YANNIS: Seasonally we have very large numbers of mullet

forming these huge groups.

This attracts a lot of predators,

including sharks, but the main species you’re probably going

to see are some of the black tips.

NARRATOR: Black tips are extremely agile sharks.

They strike schools of fish with such velocity and force,

they fly clean out of the water.

And where better to show off these deadly skills

than during the mullet run.

YANNIS (off-screen): They perform seasonal migrations and they come down

here in such vast numbers,

up to 10,000 along the beaches here.

They are mostly eating fish, but they are probably

responsible for a fair number of accidental bites on humans.

NARRATOR: Florida is infamous for shark attacks.

In 2020, there were 16 unprovoked shark bites in this state,

nearly half of all attacks in the country.

Local boat captain Greg Bogdan knows first-hand that these

attacks often involve black tips,

and oblivious tourists caught in the mullet run mayhem.

GREG: So as the fish are coming down the beach,

the big predators are pushing them closer and

closer to the beach.

And you get these people that have no idea and they swim out

and there’s sharks just crashing everywhere.

And there’s people out there,

literally in the middle of a monster feeding frenzy.

YANNIS: So, they’re hunting right next to shore?

GREG: Oh, yeah. There’s a whole series of reef that runs along the beach here

and kind of bottle necks all the bait.

YANNIS: So, the mullet can’t get any deeper.

They’re right on the beach.

The reef is really helping the predators out.

NARRATOR: Today, Yannis wants to witness the mullet run for himself,

and observe whether these black tips are

deliberately forming gangs to optimize these perfect hunting conditions.

YANNIS: I’m really interested in whether these animals are

actually hunting together.

True cooperation is where everybody has a specific job

and works together.

Orcas for example will create a barrel wave

to knock seals off the ice.

It’s much more cryptic with sharks.

It could just be that you have this big lump of food and

everybody just turns up.

It doesn’t mean they’re hunting together.

NARRATOR: Conditions are far too dangerous to enter

the water during the feeding frenzy.

So Yannis sends up a drone, to get a bird’s eye view of

whether these black tips are working together to hunt.

YANNIS: We have a pretty nice school of mullet here.

You can see how many sharks there are off shore, hundreds.

The fish don’t really have the option of going to deeper water,

they’ve been boxed in.

NARRATOR: Now that the mullet are cornered the hunt begins.

YANNIS: That sharks just accelerated into the group.

From here it looks like it could be a black tip.

You can see that halo around the sharks as they move along,

so the fish are getting out of their way.

NARRATOR: But this stealthy black tip is not alone,

his friends are along for the kill.

YANNIS (off-screen): Now we’ve got more sharks coming in,

got one, two, four, five, six.

There, now they’re getting it!

NARRATOR: Off the coast of Florida, near Miami,

Dr. Yannis Papastamatiou is watching a swarm of

black tip sharks feeding on thousands of migrating fish.

YANNIS (off-screen): Now we’ve got more sharks coming,

got one, two, four, five, six.

NARRATOR: He’s trying to work out if these predators are working alone,

or if they are deliberately forming gangs and

cooperating to hunt their prey.

YANNIS (off-screen): There, now they’re getting hit!

♪ ♪

GREG: Some of them are using the waves to kind of

group the mullet.

YANNIS: Yeah. Yeah.

♪ ♪

NARRATOR: Although dozens of black tips are attacking the

mullet in the waves, Yannis isn’t convinced that the

sharks are deliberately hunting together

in a coordinated way.

YANNIS (off-screen): A lot of it could be simple social foraging.

Social foraging is simply when individuals hunt

in a group together.

It does not mean that they’re cooperating with each other.

It could be much simpler than that.

It could just be, I chase some fish,

the fish escapes from me,

but swims straight into somebody else.

Who then gets it.

Now overtime that should benefit everybody.

If these animals hunt in a group everybody’s success goes up.

NARRATOR: Scientists are convinced sharks form gangs

for a variety of reasons.

Protection, friendship and to boost their hunting success.

But in the Indian Ocean, could there be evidence that sharks

are working together to co-ordinate their attacks, on humans.

With a staggering 23 attacks and ten fatalities since 2011.

Reunion Island, off the coast of Madagascar,

is known as the, "Shark Bite Capital,"

of the world.

The species responsible for many of these human attacks

is the bull shark.

Earning an infamous reputation as an aggressive, deadly shark.

Now a sinister incident is striking fear into beachgoers

across the Indian Ocean.

Eyewitnesses report, a man being attacked.

MAN (over radio): Oh my God!

NARRATOR: By more than one bull shark at a time.

Could one of the ocean’s deadliest predators be

working together to hunt in a pack?

In the Bahamas, Bull Shark expert

Matt Smukall, examines this hypothesis.

And believes there could be an alternative explanation.

MATT: Because there’s going to be

multiple bull sharks in the same area,

sometimes people assume that they are hunting in a pack.

I personally think each individual is listening for

these cues in the environment,

like a smacking of a fish carcass on the surface,

because it means it's a food source for them.

And what's good for one is probably good for

the three or four other sharks.

NARRATOR: Today, Matt and researcher Chessie Mason,

target a bull shark hotspot, to test Matt’s theory that

bull sharks are not hunting in packs but are feeding individually.

MATT (off-screen): All right, Chessie.

Let's just keep an eye out for any bull sharks and

start getting some of our gear ready.

CHESSIE: We're at a place where bull sharks tend to congregate.

They've got very used to associating fish carcasses

that have fallen into the marina from fishermen

with an easy meal.

MATT: You’re going to be,

kind of the eyes up here at the surface.

So just really pay attention to what’s going on and where

the sharks are coming from.

We're going to start throwing small pieces of fish into

the water and see if the bull sharks will be

drawn in and how they respond.

Do multiple bull sharks respond to that one piece of bait?

Is there a pack mentality?

NARRATOR: Acting alone or in a pack,

the bull shark is considered

the world’s most dangerous shark.

As they’ve adapted to swim in shallow waters near humans.

MATT (off-screen): It's never recommended to swim in a place that sharks

have started to associate with free food.

The safest way to be able to observe these sharks is to get in a cage,

so we don’t have to worry about watching our back.

All right, Chessie.

Let's start throwing some bait in the water.

MATT (off-screen): Bull sharks, when you see them in the water,

you know exactly why they got that name.

They're huge, their powerful, they’re just full of muscle.

NARRATOR: Bull sharks charge their prey with their giant-sized heads,

but they’ve got an even more lethal weapon.

MATT (off-screen): Bull sharks have one of the more powerful bites

in the shark world.

They have these big rows of teeth designed to grab and

eat fish whole.

CHESSIE: This is pretty incredible.

We've actually got 12 different bull sharks here, maybe more.

MATT: I think this is our chance.

You keep an eye from up here.

♪ ♪

NARRATOR: In the Bahamas, marine biologist Matt Smukall

and researcher Chessie Mason,

entice bull sharks into a marina using bait.

To observe whether or not they work together

and hunt in a gang.

Now Matt enters the water during feeding time.

(oxygen tank hissing)

MATT: It’s just an amazing opportunity to be down here

We’ve have twelve bull sharks, circling around the cage

Nice, big mature sharks, probably 8 to 9 feet

They don’t even notice I’m in the water with them

I can actually understand what they’re doing naturally

and how they behave with each other

The two sharks come in for that same piece of bait

They sense each other. One will turn away

while the other takes that piece of bait

CHESSIE: One of the sharks got the piece of food,

and the others kind of recognized that and

they all kind of dispersed.

These sharks are incredibly intelligent,

when I throw a piece of bait in you can see

them react instantly.

MATT: As those sharks are splashing at the surface,

that’s more noise and more excitement

that’s slowly drawing a couple more bull sharks into this area

NARRATOR: As the sharks pick off the pieces of bait,

Matt observes that unlike the hammerheads,

the hierarchy of these bull sharks is based mainly on size.

MATT: Some of the bigger sharks are hanging up towards the surface

and a couple of the smaller bulls

are kind of hanging out on the perimeter, looking for their opportunity

It's more of maybe a size dominance thing

where a couple of these big females

are the ones that these smaller sharks are trying to avoid

NARRATOR: In the bull shark pecking order size counts,

but Matt isn’t convinced they’re cooperating with each other.

MATT: So it doesn’t seem like there’s one particular shark that’s controlling everything

They’re not hunting in a pack

They’re individuals looking for that piece of bait on its own

It’s actually what we thought

CHESSIE: How was it? MATT: It’s amazing.

Such a nice spot to be able to observe their natural behavior

and how they’re interacting with each other.

NARRATOR: Matt’s dive reveals that bull sharks feed independently.

He also believes they’re unlikely to form gangs to attack people.

MATT(off-screen): Bull sharks have this unfair reputation as a

mindless predator and that's completely not true.

CHESSIE: They were all pretty chilled with each other.

MATT: Because of the habitat that they're in,

they have a high chance of overlapping with humans.

They go into murky water, they go in near shore.

While there are unfortunately attacks in those areas,

most likely it's mistaken identity.

And when there's a report of multiple sharks involved.

It's probably, because they're actually competing for food

rather than working together.

NARRATOR: Experts believe sharks form gangs for

protection and friendship, but they’re yet to be convinced

that these predators work together to coordinate attacks.

But in California could the ocean’s most feared predator

be hunting in gangs?

EMILY: Oh, there they are!

CHRIS: Yamilla is deploying what we call a BRUV,

which is a baited, remote, underwater video survey.

Five years ago, we wouldn’t be able to do what we are doing

now and for the first time we’ve made great strides.

NARRATOR: Using cutting edge underwater surveillance,

the Shark Lab team is now building a clearer picture of

why gangs of great white sharks are

attracted to these Californian waters.

CHRIS: So originally, we were using it as a tool to identify individuals.

But we can also use them to measure how many prey we see in that area.

NARRATOR: Using the cameras, Chris discovers that this area

is a perfect hunting ground for juvenile white sharks

of different ages.

CHRIS: We have newborns, we have one-year old’s,

two-year-old’s, three-year-old’s, four-year-old’s,

probably up to six years old all hanging out here.

We have really young ones here with more mature ones,

who are learning the ropes.

And it’s very possible that they are watching other sharks

successfully dig out and locate sting rays and

then are mimicking that behavior.

NARRATOR: So, could this be the major breakthrough?

Are these gangs of great whites learning to hunt from each other?

CHRIS: What we know is certain individuals will hang out together

and tend mimic each other.

And that’s the first indication that we have that

there’s a communication.

It is very possible that these sharks are hanging out together

and creating some sort of bond.

We’re finding that they are far more social than we’ve ever thought.

NARRATOR: If sharks are communicating,

learning from one another, maybe even hunting together.

Then perhaps the ocean’s most feared predators,

could be combining forces, in a bid to rule the deep.

Captioned by Cotter Media Group.