When Sharks Attack (2013–2020): Season 1, Episode 2 - Florida Frenzy - full transcript

The summer season
approaches when a cluster of

deadly shark attacks tears
a vacation paradise apart.

My hand's inside the shark.

I could feel... in his mouth.

These popular Mexican
beaches have never seen an

attack in their entire history.

People trusted
this area of being safe.

They had no reason
to believe otherwise.

Leaving a community
searching for answers

There just never were any
sharks here ever so how in

the world could this
possibility have happened.



This is one of the best
beaches that I think around,

it's a little north
of Ixtapa-Zihuatanejo.

It is paradise here the
thing that I like about this

particular stretch of beach is
that if you have any stress when

you come from your normal job or
where you're living environment

you can here and nothin' works
on a clock most people don't

even know what time it is here.

You get up when you get up, you
go to bed when you go to bed,

you take a siesta when you
feel like taking siesta,

any of those things that drive
you nuts on a daily basis,

they don't exist here.

Ixtapa-Zihuatanejo
lies on the Pacific Coast of

Mexico Retired Navy pilot Rick
Kennedy knows this world class

destination well.



I've been comin' here for
the better part of 13 years,

I have never heard of
shark attacks myself.

I've always just thought that
you're not gonna get hurt here,

there's nothing here
that can hurt you.

But his view
of Zihuantanejo is about

to change forever.

I was out bodysurfing
just over my shoulder here,

came in about...

I don't know I'd say 5 o'clock
or so because the water was

cold, I mean it wasn't just run
and jump like I normally do it

was tipy-toe out there and
get accustomed to the water.

As Rick warms up in
the sun he notices two surfers

enter the ocean, one of them
is 24-year-old American tourist

Adrian Ruiz.

They were the hardcore...
surfers they basically just

gotten up to the room look at
it, grabbed the boards and

ran out the door.

At the same time I noticing
there was a lot of pelicans were

flying around that day and they
were doing some nosedives from

about 50, 60 feet up just come
straight down all wings wide

open trying to catch fish.

I have never seen a
situation like that,

I had asked a couple people,
they hadn't either so something

was unusual so the eyes were
focused in that area during

that whole timeframe.

And then all of a sudden...

I see the surfer
dislodge from the board.

Rick's Navy training
kicks in and as he races towards

the scene others soon join him.

About a hundred yards off
of this rock formation here,

that's where we noticed
the individual in trouble.

So, we were comin' through
here right in between 'em is

where we picked up at.

First thing I saw was the
tear in the buttocks that was

the first thing I noticed
maybe 10 feet away.

I knew right then it
was a, a shark attack.

As a former pilot, I've seen
injury in a lot of different

disciplines, it was probably
one of the grossest things that

I've ever seen, from the knee
to here to here is gone.

And all you're looking at is
just, the skin but anything

inside of the skin is gone
except for bone.

Desperately Rick
assesses what medical attention

Adrian needs.

The injuries looked so
severe that I was just looking

for any major bleeding
point which there was none,

there was nothing we could
do, there was nothing,

there was yet no blood left in
the femoral artery I knew at

that point because there was
no bleeding and nothing to

tie off he had bled out.

Mexican authorities
confirm Adrian Ruiz as the areas

first ever shark attack victim.

And the death of an American
tourist at a popular destination

attracts the attention
of the US media.

Pete Thomas from the LA
Times, lived and breathed

the story for months.

This was a major story,
it was in the associated press,

everybody was writing about it
you know this place had never

had an attack.

They're not used
to shark attacks.

They don't expect shark
attacks also you know

this is a tourist area.

It's popular among the United
States so people trusted

this area of being safe.

They uh had no reason
to believe otherwise.

Such attention
threatens the regions tourist

based economy, as local hotel
owner Michael Bensal knows

all too well.

Marine Ixtapa, this
is the blue agave, taking off.

Within 24 hours of the attack
being on the news our e-mail box

and our phone started ringing,
because that time of year is

when our surf crowd
starts coming in.

And, uh, course they
were all freaked out.

Uh, their girlfriends
were freaked out.

Their parents were
all freaked out.

"Don't go to Mexico.

You're gonna get eaten
by a shark down there."

The big question was,
why here and why now.

The one thing that everybody
realized pretty early on was

that we had some extremely cold
water currents down here for

that time of year and the
fishermen were seeing fish they

didn't normally see, a couple
of people reported seeing some

seals down here which...

nobody's ever seen a seal down
here that, that I know of.

I talked to a lot of the
local fishermen that have,

been fishing these waters
for 30 to 40 years;

they've never heard or seen
anything like that before.

As concern for their
livelihood grows locals take

matters into their own hands.

There was a feeling of
helplessness among everybody

that relies upon the ocean.

The fishermen here, are
dependent on tourism because all

these little restaurants buy
fish from their cooperative.

They were afraid of tourism
being affected and they wanted

to prove to everybody that
we're taking care of this.

We're gonna take
some sharks out of the water and

the water will be safe again
and so After the shark attack,

there was a, a shark kill.

Local fishing guide
Ed Kunze was there at the time.

I heard about the shark hunt
the next day and I was just,

it was beyond belief for me.

I never, never imagined anything
like that ever happening here.

The fishermen went out with
barrels and long lines and cable

and you know large hooks to
catch these sharks and eliminate

the problem, however I didn't
honestly think they were going

to catch anything because I'd
been living here by ten years

and I'd only seen three or
four sharks the whole time

I lived here.

There were no sharks period.

There just never were
any sharks here ever.

But Ed soon realizes
the waters he knows so well

have changed...

We're in the village of Mohawa.

Mohawa is the location that
where the commercial fishermen

originated the shark hunt.

They actually proceeded
to catch a lot of sharks,

they had about eight or ten
sharks of fourteen up here on

the beach right
here in front of us.

Many experts however
believe the systematic killing

of sharks to be ineffective.

From a sociological
standpoint a shark hunt can be

an understandable reaction
because people want revenge.

This generally isn't very
productive because the chances

of going out into the ocean and
catching the one shark that's

responsible for the attack are
incredibly, incredibly low.

Suffice it to say, even
after the shark hunts,

the odds are that shark
is still out there.

The fisherman are
quick to flag their catch to

the media.

They hope this will stem
the exodus of tourists.

With the
sharks here on the beach,

they got the newspapers
here and the photos,

the authorities then said
look at all these sharks and

they felt that they had the
proof that we've got our shark.

However, I believe that the most
of the sharks they got was grey

shark, silver tips, reef sharks,
maybe a blue shark or two,

nothing to really denote um
the big powerful sharks.

Despite Ed's
skepticism the photo's seem

to ease the minds of the
business owners and tourists.

In the coming weeks life slowly
returns to normal in the region.

Well following the
shark hunt and after a few weeks

had passed, everybody was pretty
comfortable

we were out of the woods.

And all in all it just
started to have a better feel,

a better vibe and slowly but
surely everybody started getting

back in the water, be
it surfing, fishing,

diving whatever, having a blast
and it was time to move on and

start rebuilding.

There was a, a sigh of
relief when the sharks were

caught but my, my question was,
why did they catch so many when

we didn't have
caught any for all,

that many for ten years prior.

We arrived early...

at about 9 in the morning.

9 in the morning.

Luque is an
18-year-old local student out

with his friends
at Pantla beach,

just a 30 minute drive south of
where Adrian Ruiz was killed.

This is the
place where we went in,

here is where we were surfing.

Luque surfs with his
friend 21-year-old Osvaldo Mata.

You see the fishermen,
where those waves are breaking

around 50 meters is
where Osvaldo was.

So I caught a wave, and it took
me a little farther out There

was a moment where Osvaldo, made
a joke, He said to me "A shark!

There, ahead, a shark, I just
saw it" I was in front of them

but I thought it was a joke.

Osvaldo was in front
sitting on his board.

Osvaldo came up to the surface
and screamed All around him was

filled with blood At that moment
out of common sense I wanted to

get away but then I said to
myself 'what am I doing,

I can't leave him there!'

Osvaldo was sitting on
his board, he went around here,

and the shark entered from
here What really scared me,

and what really tore me apart.

Was hearing his scream for help
That yes... I will never forget

it I still remember it And it
sends shivers through my body

Luque desperately
calls his friends for help

as he swims to Osvaldo's aid.

By the time I got to him
he was floating I realized that

his hand, his whole wrist,
was gone So I took his arm and

put it over my shoulder.

And begin to swim with him.

Luque and his friends
drag Osvaldo to the shore.

But when they get there they
realize his injuries are even

worse then they feared.

That's when we noticed
that he was missing this part.

On his leg all of this
part was detached,

it looked like dangling pieces
of cloth.

The shark has snapped
Osvaldo femur completely

in half.

We started doing CPR,
but there were no signs of life.

There was no more blood
coming out He bled out.

Two fatal attacks
in less than a month at a top

Mexican tourist destination
sends the already frenzied media

into over drive.

Just as people were
starting to think this is over

after the first attack we had
a second attack here so the

hysteria gets heightened
at that point,

this is no fluke you know
there's something going on out

in the water that's not normal.

The second
attack was devastating.

For me personally, we probably
lost about 40% of our business

we just started getting
cancellation after cancellation.

And it didn't really
matter what we told people,

they weren't coming, they just
didn't wanna take the risk.

The press circles
and tourists cancel,

leaving the community
desperate for an explanation.

Some believe that the answer
might lie with the tourists

themselves...

After the 70s when the
tourism started in Ixtapa,

Ziohuatanejo actually became
a world class fishery,

a destination for people all
over the world to come and

sample in shore
fishing off shore,

it has so much game fish here,
I can't help believe that after

these attacks took place, and we
started looking and the people

that live here that know this
area, we got to thinking,

well they probably came here
because of the food supply.

When fish are caught
they give off distress signals

in the form of vibrations
and odors in the water.

Sharks are specially adapted
to detecting these signals.

The fishermen up in Manawa
they normally year round make

a living with their nets.

If you look at this net, you
can see there's a hole in it big

enough to put my hat through.

That hole was
created by a shark.

Fish get caught in the net,
sharks come, grab the fish,

we'll bite a hole
right on through it.

In addition to that, the poor
fisherman only had a few minutes

to get the nets out of the water
once they put them in because

the sharks hear the vibrations,
feel the vibrations and it was

like ringing a dinner bell.

But while an increase
in fishing activities might draw

sharks to the area it doesn't
explain why they would

suddenly attack people.

But one startling
new theory might.

Cartel violence was
getting a lot of publicity

at that point.

There were a lot of people
dying. It's in the newspapers.

There's graphic photos,
mutilated bodies and it was uh

it was big news going around so
people were talking about it.

It is reported that
from 2006 to 2008 drug cartel

related murders more than
quadrupled in Mexico.

The dead bodies are often
displayed in public as a message

to rival gangs.

But some believe that's not
where all the bodies end up...

So somebody put two
and two together to say hey,

they're probably dumping these
bodies in the ocean and a lot of

people thought those bodies
were attracting these sharks and

that's how they developed a
taste for human blood maybe and

that's why the sharks are
here attacking humans.

One of the theories
behind the shark attacks in

Zihuatanejo is that drug cartels
had dumped a bunch of bodies in

the water just off the coast
which attracted sharks to

the area.

While this is a horrifying idea,
scientifically it makes a lot

sense; sharks are opportunistic
predators with a great sense of

smell, they would have been
drawn into the area and would

have eaten anything there
whether it's dead or alive.

We have here a bucket of chum.

If the drug cartels had
dumped bodies into the water,

this bucket of chum would
represent what would happen as

the odors trailed
off those bodies.

Chum is a mixture of
fish and blood used

by fisherman to attract
big game fish.

This bucket contains
about 40 pounds of chum.

The average human weighs
almost 200 pounds.

If we pour some of this
into the water what we can see

is that it's gonna disperse
very, very quickly.

As you can see the water is
pulling this chum out and

it's gonna fan it out
into an odor trail.

At the other end of the trail
sharks are gonna be able

to pick up on these...

faint odor molecules and then
follow them towards a higher

concentration drawing them into
the area and possibly keeping

them in the area where people
would have then come leading up

to the attacks.

There is also a
historic precedent that lends

support to the theory In
1945 the USS Indianapolis,

delivered the worlds first
atomic bomb to the south pacific

Then two Japanese
torpedoes struck,

stranding 900 men in the water.

Within hours sharks
began to attack.

As victims were attacked
the bodies started giving off

an odor trail that would
have drawn more sharks in,

so you would have got this
gradual effect of more and more

sharks coming over the course
of time that the men were in

the water.

The shark attacks
continued for five days.

Of the 900 men who entered into
the water, only 317 made it out.

The theory that the bodies
of drug cartel victims could

attract sharks to
the area is possible,

but not everyone is convinced.

First of all as
long as I've lived here,

I haven't seen a single
body floating around and

I fish in these waters weekly.

And uh the majority of the
cartel activity is up around

the US/Mexican border couple of
thousand miles

away from here and...

any idea that they
be bringing bodies...

to dump 'em in a river
is... just nuts...

and that combined with the
fact that I mean you have to

understand how fish guts are
dumped in the waters here...

daily by the local
fishing communities,

and we'd never had
an attack here before so,

a few bodies floating
out of a river mouth...

if it happened which...

I seriously doubt it is
not gonna change things.

Whether the cartel
theory is accurate or not,

one thing is certain, the
hysteria surrounding

the unprecedented attacks
threatens to bring the regions

fragile economy to its knees.

We still had a few
people that were coming down,

a few people that were taking
their chances the big worry was

if there was another one, how
much worse can things get?

This is the beach
known as Playa Linda,

it's really good surf beach.

I live about 15 minutes north
of here... I've been surfing

these waters...
for close to 25 years.

Bruce fell in love
with this area as a tourist

then moved here permanently and
now runs a local surf shop.

May 24th I was workin'
in the shop, makin' boards,

fixin' dings so I was kinda
out of touch with the news.

I show up to the beach,
water looks different...

super green, looked like soup.

And the waves were kinda
messy, kinda choppy.

So I'm enjoyin' some surf,
everything's going good and

I just finished this really
good wave, it was a long one,

I sat up on my board, and I'm
thinking the whole time about

man I like this board
it really works good...

...and all of a sudden...

...bam I get hit from
the rear I was like,

god that's kinda spooky but I
wasn't sure what it was maybe

it was log or somethin'
I don't know So,

I'm paddlin' back out
and all of a sudden,

bam again on the rear third
of the board like back on

the tail between the fins.

I knew then this is a
shark and it was an attack.

I actually saw him go by,
passed in front of me,

and I went oh my god
this thing's huge.

He must have been ten feet he
could easily eat me, whole.

Each stroke I'm thinkin' here he
comes, he's comin' to finish me,

here he comes, here he comes
and From out of nowhere,

the shark just nails me.

All of a sudden...

I feel cold, serrated
teeth and gums,

and I'm like my hand's
inside the shark.

I could feel... in his mouth.

My hand was so far in his mouth,
that I'm thinking he's got me

he's gonna clamp down At which
point he let go and then I

pulled my hand out and it's
just bleeding profusely,

this is squirting, this is
flapping, there's bone showing,

I gotta get out of the water.

Despite his injuries
Bruce is able to catch a wave

back to shore.

I get out of the water here...

holding up my arm so it doesn't
pump out a bunch of blood and I

jog down the beach and got to my
truck as fast as I could and try

to drive one arm all
the way to the hospital.

Bruce receives
over 100 stitches.

He is the third victim on the
very same stretch of coastline

within a month.

And he soon realizes his fate
could have been much worse.

When I heard that...

a boy died the day before just
one beach north of here I was...

shocked, I mean that's two
that have died and then me,

I must be really lucky.

I immediately knew it
was the same shark. I think...

he bit the kid and saw that
that was easy and he came over,

oh here's another one...

I'll bite this guy too.

Could Bruce be right?

Could a single shark have
developed a taste for humans and

now be actively stalking the
waters enjoyed by tourists?

The answer is more frightening
then anyone could have imagined.

Nobody had really seen
sharks in the water and the MO

for every attack was identical
so we figured it must just be

one rogue shark that was behind
the whole, the whole thing.

Three shark bites, two
of them fatal within a month in

the previously safe resort area
of Ixtapa-Zihuatanejo leads some

to believe that this is the
work of a single rogue shark.

The specter of such a creature
brings the already fragile

tourist economy to a standstill.

There was an exodus.

The beach is deserted
there's nobody there.

It's like a ghost town.

So, it shook this
place, it shook it up.

There was a feeling of
desperation and people

wanted answers.

These beaches that were
normally full just completely

emptied out here, people just
were afraid to go in the water

or even get near it.

The big question was what
kind of shark was it and

where did it come from?

The evidence needed to
answer this question is scant.

Two of the victims are dead
and the third only glimpsed

the shark.

Describing it to me
approximately 10 feet long.

A clue, however, could lie in
the details of the attack on the

second victim, Osvaldo Mata,
whose femur was snapped in half

as the shark bit down.

Dan Huber is at the materials
testing lab of the University of

South Florida and thinks this
evidence might unveil the

species responsible.

The femur is the largest
and one of the strongest bones

in the human body.

And when I first heard that
Osvaldo's femur was broken I was

shocked, and what we're hoping
to do is to assess just how much

force it took to do that, which
will help us narrow down which

species it could have been.

Dan uses a cow femur
as substitute for a human bone.

If the force required to break
the bone exceeds 4000 pounds,

the species of shark could
be narrowed to a handful.

Anything less than that and the
possible suspects could be in

the dozens.

This test is gonna
replicate what would happen

during a shark attack.

We're gonna put the bone in this
space right here this hydraulic

ram is gonna simulate the lower
jaw of the shark coming up as

the mouth closes in
order to capture food.

That force is then gonna
be recorded through

a computer system.

With the bone in place
and the ram primed Dan applies

the pressure.

OK here we go, I don't know
what to expect.

As you can see the bones
snapped completely in half,

over here we can tell that is
took about 4200 pounds of force

to snap that femur in half,
that's over two tons of force

If we then relate that to human
femurs at that level of force it

rules out most every shark
species that we have in coastal

waters except for the big
three: the bull shark,

the tiger shark and
the white shark.

The nature of the
attacks and the water conditions

at the time means one shark
emerges as the prime suspect.

Given that this shark was
a powerful shark it bit through

Osvaldo's femur and given that
the water was unusually cold,

people started thinking great
white sharks in fact some people

thought this was the work of one
great white shark a rogue great

white that was all of a
sudden here, hunting people.

That's what you had in jaws and
there was a jaws situation

down here.

The atmosphere was pretty
similar and pretty sensational.

White sharks are the
largest predatory fish in

the world.

They get up to about 21 feet
long and are highly aggressive,

they tend to live in cold waters
that are also inhabited by seals

They generally don't inhabit
this part of the world;

the one part of Mexico where you
can reliably find white sharks

is up in the Baja area
in the Guadalupe Islands.

But the fact of the matter is
the more that we study these

animals the more we find they
pop up in unexpected areas.

In 2012 a 20-foot
long great white was caught near

Guaymas in the Sea of Cortez
meaning it likely would have had

to have travelled far
south of the Guadalupe Islands

to get there.

So could a great white have been
drawn even further south by the

unusually cold waters and
seals in Ixtapa-Zihuatanejo?

I think the authorities
at the time were dumbfounded,

there had never been an attack,
they didn't know how to respond,

amid the panic they brought
in George Burgess because

if any body could figure out
why the attacks occurred

it was gonna be him.

George Burgess is the
director of the international

shark attack file and is
one of the top shark attack

investigators in the world.

Any time you get
multiple attack over a short

time or place it's intriguing
because it is away from the norm

we come in as a detective
would and look for how, where,

and when, and why...

We started looking back at our
previous records of attacks from

the West Coast of Mexico to
compare those dates and

times with previous... events.

Such records show that
there was a similar cluster of 4

fatal shark attacks in Acapulco,
more than 4 hours south,

over a 12-month period
in 1972 and 1973.

Interestingly enough a
number of those attacks occurred

in cooler water temperature
which was the same...

as what we saw in the
Zihuatanejo attacks situation

that was the smoking
gun so to speak.

These previous attacks
and the presence of cold water

leads Burgess to a startling new
theory and one that will turn

the entire investigation
on its head.

The town and the tourism
was on the verge of collapse.

This was catastrophic.

The fact that there had
been a prolonged period of cold

water as well as that the waters
were greenish in hue made us

start to think there was a
major environmental difference,

at this place and time.

George Burgess is
attempting to solve the mystery

of how three people came to be
attacked, two of them fatally,

in the normally safe waters
of Ixtapa-Zihuatenejo.

It's a riddle that has him
scouring the history

books for clues.

We went back and sort
of looked at some of the attacks

that occurred in Acapulco
farther south in previous years

and saw that maybe there was
a correlation between them.

A 12-month period in
1972 and 1973 saw four tourists

killed off the same
stretch of coastline.

Many of these attacks also
occurred in atypically cold

water for the region.

I immediately asked one
of my assistants to check on

La Ni?a events simply because
those are such a huge...

motivators of, of local
conditions on,

on the West Coast.

La Ni?a is a climate
pattern in the Pacific Ocean

where changes in ocean currents
lead to cold water coming up

from the depths and being pushed
from the West Pacific Ocean out

towards the East Pacific Ocean.

Sure enough, the
data confirms Burgesses hunch.

La Nina occurred in
both 1973 and 2008.

The mass of cold water...

would have just taken up
all of the space in here...

and it retains its
integrity for a long period.

This little pocket of water,
pushed against the coastline

in Zihuatanejo...

and it stayed there
for months on end.

This mass of cold
water seems to support

the theory that a rogue great
white shark is responsible

for the attacks.

Burgess however thinks not
all of the evidence adds up.

Bruce Grimes the
third victim and the one of

the three that survived...

indicated that there were series
of bumps on his boards before he

ended up gettin' bit However
white sharks generally are,

are surprise predators
and, and what we call sneak

attackers... they attack
from below and behind.

Whereas bulls and tigers often
times will do what we call bump

and bite attacks. Where...

the human is actually contacted
one or more times before

the actual attack occurs so...

it clearly wasn't a white shark.

These attacks were
probably one of two species

either bulls sharks
or tiger sharks.

But there's a
problem with this theory.

These species aren't normally
found in cold water...

Bull sharks and tiger
sharks are both tropical species

that generally prefer warmer
waters and so this upwelling of

cold water would push the sharks
away and therefore there are

lots of different factors
that have to be considered.

There were a lot of
unanswered questions especially

among the locals,
they don't know,

they don't know if there's
gonna be another attack

so they're deeply concerned
and so after the third attack,

the navy wants to get involved.

They took to the air, they
wanted to patrol the coast to

see what they could find.

The navy's aim is to
scan the coastline in the hope

of reporting back that
the waters are safe.

But they see something
they never expected.

The third
attack with Bruce Grimes,

it happened right here in front
of this river bar right here.

The navy helicopter was right
up here in this spot we're in

basically right now and right
down in that water they saw

12 big huge sharks lined up in
front of the river mouth plus,

up and down this coastline,
stretch of about thirty miles,

they saw hundreds.

It was like schools of sharks.

The sight of hundreds
of sharks like these swimming

just yards from the shore
sends shockwaves through

the community.

The panic and confusion
it the community was just

incredible.

We are not talking about
one or two incidences now,

we're got lots and lot of shark
and a great possibility of

another instance where
somebody was going to get bit.

It was infestation

After the third attack, the
navy actually went up

in the helicopter to
examine the coastline

to see what's going on.

They saw showed lined up
in front of the river bar,

12 huge sharks.

Plus in that stretch of coast,
hundreds, two hundred fifty,

three hundred sharks
from the air. Incredible.

The thing about
this pack of sharks is uh

it kind of dispels the notion
that there's one rogue shark.

So instead of a rogue shark
they have a rogue pack,

and that pack is pointed
toward the shoreline.

The sharks being lined up
like that they could have been

thinking they're just waiting
for people to walk in the water

off of the river bar, I wondered
how in the world when we've

never had sharks here before
could this possibly

have happened?

What has caused so
many sharks to mass along

the coast?

Are they here to stay?

Will there be more attacks?
And what species are they?

George Burgess believes the area
the sharks are schooling is a

vital clue.

The fact that the
sharks were observed right on

river mouths... alarm bells
started goin' off right away.

The third attack occurred right
here at the mouth of this,

this river... and...

to the north was another river
and that's where the second

attack occurred.

The previous attack which was
farther up the coastline was

more on an open sandy beach...

but again it was bracketed by a,
a series of rivers on each side.

This is more than coincidence.

River mouths are areas where
where salt and freshwater mix

anytime you have a situation
where there's a river mouth that

immediately gets the, the
light bulb on for bull sharks.

Bull sharks are
incredibly aggressive shark

species they get up to about
12-feet long and pound for pound

they have the most powerful
bite of any shark species

studied to date.

What makes them so amazing is
they are the only species that

can completely move between
salt water and fresh water on a

regular basis which is why bull
sharks spend a lot of time near

the mouths of rivers.

When you look at all different
factors this absolutely points

to bull sharks.

Bull sharks, however,
normally only inhabit warm water

so why are they schooling in
massive numbers in Zihuatanejo?

Will they attack again?
And are they here to stay?

I, swam and surfed
and fished in these waters

for years and...

we just don't see bull sharks
down here so nobody really knew

for sure what was going on.

Immediately it's
intriguing and so you

immediately start thinking well,
might draw the sharks in you

know, what, what kind of
factors might be involved.

People in the region
were reporting lots and lots of

marine life during this time
This makes a lot of sense during

a La Ni?a event; the upwelling
of cold water brings a lot of

nutrients to the surface which
supports a very different type

of ecosystem, to the point at
which the apex predators start

coming in to consume all of this
vibrant life that's been growing

during the upwelling.

Now while this cold water might,
in one sense would push bull

sharks away the fact of the
matter is that having a readily

available source of food is
always gonna trump changes in

water temperature when it
comes to big coastal predators

like bull sharks.

But if it's an
abundance of food that has drawn

bull sharks to the area, why
would they attack humans?

The reason the waters
were greenish in hue is that

that nutrients allows for growth
in a lot of vital plankton,

the little plant organisms that
are the basis of life if you

will in the sea, and with
that means visibility is poor.

Poor visibility in the
water is often a key factor in

shark attacks.

When a shark is in murky
water and it can't use vision

to hunt it has rely on
its other senses.

This makes it harder to
distinguish between a human and

a fish and makes the shark more
likely to attack regardless of

what that prey item is.

The activities of a
surfer in the surf zone where

visibility is poor...

were attractive to a large
shark such as a bull shark which

normally consumes
large prey items...

and they probably
would be quick to,

to jump on the opportunity
for, for a meal.

So a combination of animal
and human behavior and

environment all contributed
to these attacks.

When the water warmed up, we
knew they were gone because they

were only here because
of the cold water,

and they haven't
been back either.

So, in all likelihood,
the La Nina event brought

nutrient filled cold water to
the shallows of Zihuatanejo

drawing an entirely new
ecosystem including

bull sharks to the area.

And as the waters turned green
with plankton it seems the bull

sharks struck out at surfers
believing them to be their

normal prey.

When the waters finally warmed
and the ecosystem seemed to

return to normal,
the attacks stopped.

At least for now.

The reality is that
the big draw to this area is

the natural beauty and
sometimes nature bites back.

And of course somewhere in the
back of all of our minds here,

we know this could
happen again here.

Uh you know we hope, we
hope it doesn't but uh

at the end of the day we
can't stop it.