Sharks vs. Dolphins: Bahamas Battleground (2023) Movie Script
NARRATOR: The waters off The
Bahamas are a battleground.
In the war between sharks
and dolphins.
Using photographic evidence.
MIKE: One species that might
cause that kind of bite
would be a bull shark.
NARRATOR: Specialized
bite pads.
MIKE: It went through this
simulated dolphin blubber
like butter.
NARRATOR: And, for
the first time ever,
a decoy dolphin as
their secret weapon.
These biologists will
attempt to uncover
which sharks are
the culprits.
MIKE: That dolphin
is in big trouble.
They're coming right for it!
Yes!
NARRATOR: Shedding new light
on these two apex predators,
locked in deadly
underwater combat.
BOATER: Hey, they're
fighting they're fighting.
Oh!
He's got a dolphin in
its mouth!
It's right under us.
Look at the size of
the thing.
NARRATOR: A bloody
battle, as old as time,
is being waged
beneath the waves.
Shark versus dolphin.
One of the front lines
for this oceanic clash
is located 55 miles
off of Florida.
Bimini is part of 700 islands
that make up The Bahamas.
Nearly one third of
dolphins here show signs
of shark attack.
A team of shark and dolphin
researchers is here
to discover what sharks are
targeting these dolphins,
the Atlantic Spotted Dolphin
and the sleek grey Bottlenose.
KEL: We've got
dolphins on the bow.
VALERIA: Wow, look
at them ride.
NARRATOR: Dr. Mike Heithaus
is a shark specialist
and a Dean at Florida
International University.
He's joined by Dr. Valeria
Paz, a dolphin expert,
and local Bahama
dolphin researcher
Kel Melillo Sweeting.
First part of the mission:
photograph the scars to
match them to the predators.
VALERIA: Hey, Mike. Did
you see that notch
on that dorsal fin?
MIKE: Yeah. You know
that couple notches there,
yeah, that's the kind of
injury that could be caused
by a shark.
KEL: Two mother-calf pairs.
One of them had a
distinct shark bite scar.
She actually got that
injury as an older calf,
younger juvenile.
So what we're seeing
now is a few years old,
really well-healed scar.
VALERIA: She came really
close, so I was able
to get some really
good footage.
NARRATOR: While foraging,
some dolphins occasionally
break away
from the pod to crater feed.
Turning upright,
using their nose,
or rostrum to dig
and find prey.
This is when the dolphins
are most vulnerable.
KEL: They have to remain
vigilant because a shark
could be around at
any moment.
We're also seeing signs of
previous shark attacks.
One bottlenose dolphin had
both pectoral fins injured.
MIKE: Here in the Bahamas,
you can find more
than a dozen species
of sharks.
But it's most likely the
ones attacking dolphins
are the bigger bull
sharks, tiger sharks,
and maybe great hammerheads.
These are the top
predators here.
What a great snorkel.
A couple mom-calf pairs.
There was one that it
looked like had a bite
on the peduncle there.
KEL: Yes. Maybe a shark
sneaking up from behind?
MIKE: Hopefully the
pictures will help.
KEL: Yes.
NARRATOR: With so many
large sharks in this area,
the dolphins have a lot
of possible predators.
VALERIA: This bite is
definitely on the side
of the flank so maybe
it was trying to escape
or evade when it turned
and then it got bit.
MIKE: Yeah, you see it's
a pretty broad bite.
One other species that
might be able to do that
something like the
tiger shark,
they just have that big wide
head compared to other sharks.
And then their teeth
are really different.
You've got similar sized teeth
in the top and bottom jaws.
Instead of being
for puncturing
they're really meant
for cutting.
And you've got really fairly
long distances between the
teeth, so that should
give us some clues.
KEL: This is a
bottlenose dolphin,
took this photograph right
around Bimini and you can see
it has a pretty fresh
injury to its back here.
VALERIA: That's fairly
sizeable.
MIKE: Yeah and it's
super clean too,
so not a lot of diagnostics
there and one animal
that could do that around
here is the bull shark.
This is a replica jaw, you
can see that's a big mouth
but with a clean bite a
really big great hammerhead
might be able to leave
a mark like that.
Now we just need to get
impressions of shark bites
so we can get a sense
of how they're holding
and gripping and releasing
the prey and what that
would look like on a dolphin.
NARRATOR: There are 10
types of hammerheads,
but here in Bimini, the
team sets out in search
of the great
hammerhead to see
how it might be biting
these undersea mammals.
Up to 20 feet Long, as large
as a fully grown great white,
these giants congregate in
the shallows off Bimini.
MIKE: These great
hammerheads are huge sharks.
They have speed,
maneuverability
and the teeth in the upper
and lower jaw are different.
You get kind of cutting teeth
on the top and gripping
teeth on the bottom.
So it's possible that great
hammerheads are taking out
dolphin calves and if they get
one of those in their mouth,
it's going to be really hard
for that dolphin to get away.
NARRATOR: Mike and
Valeria want to see
what great hammerhead bites
look like on prey to compare
with the scars they've
photographed on the dolphins.
Local shark diver Neal
Watson has been working
with hammerheads here
for more than a decade.
He's going to help the
team get a bite impression.
NEAL: Today we're going to
try and feed a whole bonito
to one of the hammerheads
and the key difference
is we're going to try and
actually get it back.
It's something unique
that we don't do usually
but I think we'll be
able to give it a shot.
MIKE: When we're gearing
up to dive with sharks,
I'm really always running
through worst possible cases
in my head, because you
got to be prepared.
I'm always thinking
about, okay,
if a shark is aggressive,
what are we going to do?
Where am I going to be
relative to Valeria?
What am I going to do
if a shark comes around
from behind? You have to be
really, really vigilant
whenever you're dealing
with large, potentially
dangerous animals.
Great hammerheads
don't attack humans,
but we're going to see how
they feel about visitors.
NARRATOR: The smell of fish
may entice the hammerhead,
but also bring in other
species of sharks.
VALERIA: Tiger shark and I
think I see some bull sharks
coming in.
NARRATOR: Tiger sharks and
bull sharks are ambush
predators, known to
sneak up on their prey,
so the team stays on
high alert waiting
for the great hammerheads.
VALERIA: Those nurse sharks
are definitely coming
to check us out.
And although their
jaws might seem small,
once they bite onto something,
they really hold on.
MIKE: We have to keep
this fish away from them
or we might not get it back.
NARRATOR: Finally, the great
hammerhead approaches,
and her size lives
up to the name.
VALERIA: Wow, that
is a beautiful shark.
Probably about 12
feet or more.
MIKE: Yeah, that's
a large female.
Definitely big enough
to eat a dolphin.
This hammerhead
seems interested.
VALERIA: Hey Mike,
tiger shark behind you.
MIKE: Here she comes!
Oh man she's trying
to swallow it whole.
Well, there goes one bonito.
VALERIA: We've got
another hammerhead.
MIKE: We've got to get the
hammerhead to let go of
that fish.
Looks like the hammerhead
is coming back around
for another go.
Okay, let it go, let it go!
VALERIA: Yes, you got it!
MIKE: Let's get
this up to the boat.
What an incredible dive.
VALERIA: That was unbelievable,
those hammerheads.
The size of that one.
Must have been 12
to 14 feet maybe?
MIKE: Definitely capable of
taking out a spotted dolphin,
maybe a bottlenose
dolphin juvenile.
VALERIA: I'm excited
to see that fish.
MIKE: Well, after all that
we got one bonito head back.
VALERIA: Definitely
scraped all the skin out.
MIKE: Yeah. It's not
a clean cut
by any means and bonito
is not a dolphin
but I guess if that was a
hammerhead biting a dolphin
you wouldn't expect
something clean.
It would probably be more
scrapes through the tissue.
NARRATOR: The tearing bite
of the hammerhead matches
the ragged scars seen
on the dolphins.
VALERIA: That's
definitely what we saw
when the hammerhead was
approaching the fish
and it grabbed it
and kind of teared.
It was not a clean cut.
MIKE: No. So. We didn't
get tooth impressions
like you might hope for
but it's some
first clues.
For the sharks and
dolphins here off Bimini,
they're pretty
well-matched adversaries.
The sharks, body size,
strength, cutting teeth.
And the dolphins live in
groups, they're smart,
and they're super-fast
and maneuverable.
NARRATOR: To observe just
how intelligent dolphins
are Mike and Valeria
head to the Clearwater
Marine Aquarium in Florida.
All of the dolphins here
are injured or unable
to survive in the wild and
cannot be released.
Animal care specialist
Katie Wojdyla provides
daily enrichment.
KATIE: Right now I'm doing
what we call face time
and all it is is a
little playtime,
it's offering them
any interaction
if they would like it.
We have right here in
front of you is Hope.
She's currently 11 years old.
She really seems to
enjoy water play.
NARRATOR: Animal care
specialist Brooke Bowersox
has seen the damage
sharks can do first hand.
BROOKE: This is PJ, you can
see that she has a nice scar
back there on her peduncle.
MIKE: Yeah, and that just
looks like a fresh bite
that we see on dolphins
like the ones in Bimini.
You see that's
not the only scar,
there's also places where it
looks like the jaws come over.
VALERIA: Since the
scar healed so well,
it's really difficult
to tell what species
could've made that.
MIKE: Yes, a bull, tiger
even great hammerhead,
you just can't tell
from that healed wound.
NARRATOR: To avoid attacks,
dolphins have an arsenal
of defenses, including
intelligence.
With brain mass larger
than any shark's,
dolphins are second only
to humans in brain
to body weight ratio.
Making it easy for them
to outsmart sharks.
But they also have a secret
weapon to evade predators:
echolocation.
MIKE: Echolocation is
really kind of a dolphin's
superpower.
VALERIA: Dolphins emit sound
and they have a part of
their head that is
called the melon.
This area receives
the sound waves,
and it translates
to what's going on
in their surroundings.
It allows them to navigate
without using sight.
NARRATOR: Echolocation
helps dolphins find prey
or detect predators.
MIKE: We're going to do an
experiment to figure out
how we can use echolocation
or how effective it is,
but first we've got to let
him use all his senses.
What are we going to do?
BROOKE: Yeah.
So this is a cognitive concept
called the match to sample.
What we're going to do is
we're going to show Nicholas
this buoy and then we're
going to ask him to go across
to the other side of the
pool where there's three
different sample items
and ask him to select
which one matches what
he's seeing here.
And you can see that
he got it right.
MIKE: He did pretty
well at that last one,
but now it's time to
turn out the lights
and just do echolocation.
How does this trial work?
BROOKE: So what we're
going to do now
is we're going to place eye
cups over Nicholas' eyes
and Bree is going to send
him over to our right
with Katie is, where he's
going to echolocate
on that red boat.
Once he echolocates on it,
he's going to travel over
to where our samples are
and they have those samples
under water. So using
his echolocation,
he can make the
correct selection.
MIKE: You see just
no hesitation.
No worry about having his
eyes, just echolocation
straight there.
BROOKE: Correct.
VALERIA: And he did.
MIKE: It's incredible.
So, this really just
shows how impressive
that echolocation is.
Also shows how smart they
are and that smarts
and echolocation help them
survive out in the wild,
including avoiding sharks.
BROOKE: Absolutely.
NARRATOR: Back in The Bahamas,
Mike and Valeria believe
hammerheads could be
responsible for some
of the ragged bite scars
they've photographed
on dolphins.
But they want to
investigate another shark
that may be a predator.
And this one is second
only to the great white
in the number of
attacks on humans.
Tiger sharks.
Growing up to 18 feet,
weighing nearly a ton
they'll eat just
about anything
from tires to turtles.
BOATER: No way.
NARRATOR: To dolphins.
New South Wales, Australia.
Off the coast of Newcastle,
a tiger shark goes in
for the kill.
A lone dolphin is no match
for the 11-foot tiger shark.
It disables its tail and the
dolphin is dead in the water.
MIKE: Tiger sharks are
incredible predators.
They also have teeth that are
curved and have serrations,
so they cut in
both directions.
So once they grab
onto something,
they can shake their
heads back and forth
and cut straight through it.
NARRATOR: And there's no
place better to find tigers
than Tiger Beach,
in The Bahamas.
The team will try to get
bite impressions
from the tiger sharks and
study the tiger's feeding
style to compare that with
their photos of dolphins
with shark attack scars.
Underwater cinematographer
Duncan Brake has been diving
these waters for
more than a decade.
Neal Watson will be using
whole bonito again
to get a bite impression.
Immediately, the team is
met with an eager
group of tiger sharks.
MIKE: We want to get a tiger
shark to bite the bonito
to examine how it uses
those serrated teeth.
We've got one heading in.
VALERIA: There's a lot of
lemon sharks coming in, too.
MIKE: Lemon sharks don't have
much sense of personal space
and they can be aggressive
eaters, so let's keep
the bait away from them.
NARRATOR: The lingering smell
of the bonito fish starts
to catch the
sharks' attention.
Two tigers approach.
MIKE: We usually think of
tiger sharks as solitary
animals, but this fish
has caught the interest
of more than a couple.
VALERIA: This one's
definitely interested.
MIKE: Come on! Hold on! Yes!
NARRATOR: Neal manages to
hold on to part of the fish.
MIKE: Let's get
up to the surface.
VALERIA: That was incredible.
Such large animals.
MIKE: No shortage of sharks.
NEAL: None.
MIKE: And I think we're
going to need bigger bonito
next time.
NEAL: Yeah.
These are big three-foot
bonitas but they're kind
of a one-bite meal for
these tiger sharks.
I was able to wrestle
this piece away.
I think it was indicative
how they were feeding.
They would grab the bait and
if they only got a little bit
of it they would let go
momentarily to try
and get a little bit closer
and I was able to pull it out.
MIKE: And that's what you see
on the dolphins sometimes.
It's not just always a clean
bite in but it looks like
there's bite and slash
release bite again.
And that's kind of what you
see here on that bonito.
VALERIA: Yeah. That's
definitely similar
to the scars that
Kelly showed us.
NARRATOR: The tiger sharks'
slashing bite matches
what the scientists saw
on the dolphins.
KEL: For a shark, a
dolphin is no easy meal,
but is a really rich meal.
Lots of meat, lots of blubber.
But the dolphins have
evolved to fight back.
MIKE: Once dolphins
have seen a shark,
it's kind of the game's
up for the shark,
it's not going be successful
and the dolphins will
actually kind of chase
and herd sharks away.
There's one video where a
juvenile great white shark
approaches a group of
dolphins and one dolphin
peels off and just
chases that shark away
and the sharks just
kind of, "Forget it.
It's not worth it,"
and it heads out.
These dolphins are not just
swimming snacks for sharks,
they can detect sharks and
kind of hold their own.
NARRATOR: Dolphins have
one more advantage:
the ability to communicate
with one another.
VALERIA: Dolphins are
definitely chatty
and they use sound
to communicate,
and it's really important
to their everyday life.
KEL: We're observing some
Atlantic spotted dolphins
and we're going to use
this hydrophone,
an underwater microphone,
to hear the sounds
through the headphones and
hear their whistles, squeaks,
squawks, chirps.
Vocalizations are super
important to dolphins,
to help keep track of
the group, find food,
possibly even alert each other
to predators like sharks.
NARRATOR: Even with
echolocation and the ability
to communicate, dolphins in
The Bahamas are still
under siege.
The team concludes
that the ragged scars
they've seen on the dolphins
could be from tiger sharks
and hammerheads.
But many of the scars they
photographed were cleaner
and more defined.
Could there be a third species
of shark attacking dolphins?
Bull sharks have the greatest
bite force of any shark
relative to their body size.
Could they be responsible
for preying on dolphins?
They prowl the shallow seas,
using the sandy bottom
and murky water to
conceal their attack.
Both dolphins and humans
never see them coming,
until, it's too late.
MIKE: Here in Bimini,
the bull sharks
and the dolphins are often
hunting in the same areas,
and that can include
murky waters.
The bull sharks are probably
mainly hunting for smaller
things, but if they get a
chance to grab a dolphin,
they're going to take it
because that dolphin
represents an incredible
meal with all the fat
and energy in the blubber.
NARRATOR: The team needs
a bite impression
from the bull shark to compare
to the dolphin scars.
But this time they'll
attempt something
that's never been
done before.
They're creating a
life-sized dolphin decoy,
but first they need to
test out the material
they'll be using to
make the dolphin,
while also collecting
more bite data.
MIKE: This is basically
a gelatin block
that is the density
of dolphin blubber
and we've turned it into a
giant underwater lollipop.
So what we'll do is put a
little bit of fish on this
to entice a shark to bite.
And when they bite it,
it's going to give us
a jaw impression.
NARRATOR: They head to the
waters between Florida
and Bimini.
MIKE: This is the
perfect place to come
to find bull sharks. There's
lots of food here,
the water temperatures
are right
and it's a known spot where
groups of bull sharks
get together.
NARRATOR: While
Mike gets the bite,
Valeria will be on
shark measuring duty.
A laser device can
pinpoint the exact length
of the shark.
MIKE: Bull sharks have a
reputation as a more
aggressive species, but they
usually don't bother divers.
But we do have bait
on the pad here,
so we've got to stay alert.
VALERIA: Copy that.
A couple of bull
sharks are coming in.
I'm going to get
some measurements.
They look definitely the size
that would attack a dolphin.
MIKE: They're
interested in the fish,
but they're being cautious.
VALERIA: They're definitely
curious, just not biting.
MIKE: Wait. This one's
coming back around.
VALERIA: Watch out,
your hands!
MIKE: Didn't even see it.
(bleep)
I count three bull sharks.
They're all more
than 6 feet long.
I'd say they're big enough
to attack a dolphin.
We just need to get
one to bite this pad.
Oh, that was close!
VALERIA: We need a good bite
and the size of the shark,
to compare it to the bite
marks on the dolphins
in Bimini.
MIKE: Wait a minute.
I think we have
another taker!
I can't hold it!
VALERIA: That bull's coming
right back around Mike.
MIKE: Get the lasers ready.
VALERIA: Yes, we got it!
MIKE: Look at that.
Oh, this is incredible.
You just see the
width of that bite,
it just bit on and went
through this simulated
dolphin blubber like butter.
You can see why dolphins
just lose big chunks
if a big shark gets a hold
of them, and that one,
we got a really
nice laser hit on.
So we'll know exactly
how big the bull shark
was that did that.
And we got a bonus. This
shark left a tooth behind.
They lose so many
teeth in their lives.
They're constantly
shedding. So
a loose tooth, even in dolphin
blubber can get stuck.
Usually, we're not so lucky
to have them left behind.
A nice bite width there
on a real-world situation.
So this is exactly what
we wanted, I am psyched.
NARRATOR: The bite pad
reveals that the ragged bite
marks from the photos
were probably not caused
by the bull shark.
The precise incision on the
pad could mean bull sharks
are the ones leaving
the cleaner scars.
But there's another way
to find out whether
these bull sharks
have attacked
the underwater mammals.
MIKE: Right now we're trying
to catch a bull shark.
We got a piece of bonito
on a small circle hook
so we can throw it to the
bull shark that we want,
catch it, get it up, and see
if it's eaten a dolphin.
NARRATOR: In sharks, the
reproductive and digestive
systems come together at
a common area called
the cloaca, so the team will
take a sample from this area.
VALERIA: So here's
the swab kit.
We're going to be using the
cotton swabs to get fecal
matter from the bull shark
and that will tell us
a little bit about what
they have been eating.
That is going to be really
useful to see if we see
any dolphin DNA in
this fecal matter.
MIKE: First, we
have to catch one.
Handling sharks can
be really dangerous
if you're not careful and
that's especially true
for bull sharks.
They got that big
mouth, sharp teeth,
but the tail is
incredibly powerful.
So you've got to always be
aware of your surroundings
and work together as a team.
There we go.
Okay there's a bull
shark right below us.
VALERIA: See it.
MIKE: They're right
next to it.
Yes, it's on, it's
on it, it's on it.
VALERIA: Oh. Nice.
MIKE: Okay now I need
everybody to be beyond
careful right now.
-Yeah.
Right down there. It's a
good sized one for sure.
Watch your feet,
watch your feet.
That is a big bull shark.
VALERIA: Oh. It's a big one.
MIKE: Fresh shark, the
trick now is to hold on
as much as you can.
Ah!
That is definitely big
enough to attack a dolphin.
No question.
Okay. Get ready.
I'll start back further,
try to bring it around.
Well, we're trying to get a
tail rope on it so we get.
VALERIA: I got you. I
got you. I got you.
MIKE: Slow, slow, slow,
you're good, you're good,
you're good. Nice and easy.
Oh close.
Okay. Excellent.
Okay. Good job. Okay.
Now, we've got control of the
animal, so now, cleat that off.
A little bit lower.
A little bit lower,
so its tail's kind
of in. Good.
NARRATOR: But just as they're
about to tie the shark off.
MIKE: Oh no, look out, look
out, clear clear, clear!
Look out. Careful. Careful.
No, do not grab this.
It popped the monofilament.
NARRRATOR: They've lost
control of the most
dangerous part of the
shark, its jaws!
MIKE: Back off! Back off!
MIKE: Agh!
No, do not grab this.
It popped.
We had the shark actually drop
when there was a swell and it
popped that monofilament, so
we're just going to do a quick
repair on the fly, so we have
control of the animal here.
I need another roundy.
I'm going to tie into this,
and get the crimping tool.
VALERIA: I got it.
MIKE: We've got to
write down the lengths.
Mark that, 216.5.
VALERIA: 216.5.
MIKE: 252. That's about 8
and a half foot Bull Shark.
That's definitely big enough
to go after a dolphin. Okay.
Get the cloacal swab kit.
VALERIA: Yup.
We are going to be opening up
the swab kit and making sure
that everything is set
up for the cloacal swab.
Make sure this is up so
that it's out of the water.
MIKE: Okay.
VALERIA: All right.
MIKE: Great job.
That's perfect.
VALERIA: Here we
have the vial.
We're going to go ahead
and place it in here
and make sure to label it
and we'll send it out to
the lab to find out what
sharks have been eating.
MIKE: Okay, we can
release any time.
NARRATOR: Releasing an angry
shark is even more dangerous
than catching it.
The crew has to be careful
not to get caught
in the lines as it thrashes.
MIKE: Look out.
Okay. Hang on. Hang
on, hang on.
Are we ready?
here we go. Three, two. One.
Great, great. Good job.
That was great.
We got that shark up, tag
in, cloacal swab done,
and a great release.
The cloacal swab showed us
these bull sharks hadn't
eaten a dolphin recently,
but that doesn't mean
they're not dolphin
predators.
It just means they're not
eating them all the time.
NARRATOR: The cloacal
swab was inconclusive
but the bite pad shows that
bull sharks could be the ones
making the clean bites
seen in the photos.
Mike and team are now ready
to deploy their nearly
200-pound secret weapon.
They want to get an even
more realistic view of what
a bull shark bite would look
like on a real dolphin.
MIKE: This is Gooey, our
dolphin model and Gooey
was made out of
non-toxic gelatin.
We want to make sure if a
shark gets a mouthful
of Gooey, it's completely
harmless to the shark.
Gooey was made so that the
consistency is exactly
like that of dolphin
blubber.
And it's pretty much the same
size as an Atlantic spotted
dolphin in Bimini or
a juvenile bottlenose.
NARRATOR: This is the
first time a dolphin decoy
made of non-toxic
materials will be used
in shark research.
MIKE: The bite-pads
were a great first step,
but they're just kind
of a fairly narrow pad
and so a shark might bite
that very differently
than something that's
shaped like a dolphin.
It's rounded and in some
places it's so big
that it's kind of like
trying to palm a ball
that's too big for a shark
trying to bite it.
So we have created something
completely unique,
a gelatin dolphin.
NARRATOR: It's sink or
swim time for Gooey.
The team takes her to an
area known for bull sharks.
They're joined by underwater
cameraman Sean Havas,
who will capture this
"first" in shark research.
MIKE: As soon as Sean and
I are in let's get Gooey
in right next to us.
VALERIA: You got it.
I'll be looking at you
guys for directions.
Once I put it in if you need
me to give it some life.
MIKE: We'll let you know
but hopefully Gooey
will do its job.
VALERIA: We're strapping a
camera onto Gooey to get
a better angle.
We're positioning it so that
it faces the peduncle area
where we think sharks may
be more enticed to bite.
Mike, should we deploy
Gooey?
MIKE: Ready for Gooey.
VALERIA: Copy. We'll deploy.
You got it Mike.
NARRATOR: Deploying this
enormous dolphin decoy
takes teamwork.
VALERIA: Kirk,
look at the camera.
Make sure it's at the right
angle when it gets deployed.
Lucas, make sure that the
pectoral fins are not getting
stuck by the ladder,
and let's do this.
All right. Please
clear the deck.
One, two. Slide.
MIKE: All right.
Gooey's swimming.
VALERIA: Mike, what are
you seeing down there?
MIKE: Well, right now,
it's pretty lonely.
Just hanging out with
Gooey. No sharks yet.
So hopefully, we get
some interest soon.
VALERIA: Gooey right now
doing a natural behavior.
This is called logging.
Logging is when
they're resting and there
may be more vulnerable
during this behavior.
MIKE: We got Gooey exactly
where we need it to be.
It looks so real!
VALERIA: Gooey is of similar
size of those dolphins
that we saw in Bimini.
Although her colorations
are a lot different,
the silhouette
from below mimics
that of a real dolphin.
NARRATOR: Sharks are
attracted to contrast.
They may not see color,
but this silhouette
should lure them in.
If one attacks, Mike will not
only get a bite impression,
but the exact size
of the shark.
They'll be able to record
if smaller juvenile sharks
might attack a dolphin,
or is it mostly
the larger mature sharks.
MIKE: The idea is, we want
to get length on the shark
that attacks Gooey so we
know not just what species
grabbed the model, but
how big it was.
NARRATOR: The bull
sharks arrive.
And it's time to put
Gooey to the test.
Will she be a trick or
treat for the bulls?
MIKE: These are big
bull sharks.
They are definitely a
threat to the dolphin.
We've got four sharks,
they're circling
but we're not seeing a whole
lot of interest right now.
Try giving Gooey some motion.
VALERIA: Copy Mike, will
give it some movement.
Kirk, can you please
give it some motion?
MIKE: No. Still
not interested.
That's not terribly
surprising since bull sharks
probably only very, very
occasionally attack
dolphins that they see.
She looks like a dolphin and
kind of moves like a dolphin.
Maybe we need to add
some smell.
Sharks have an incredible
sense of smell.
They can smell a couple of
drops of blood in a swimming
pool worth of water.
That means that if there's
a good scent trail,
they can follow it for miles.
Now one is starting
to move toward it.
Come on! No. Okay.
We may have to do a
bit more than this.
We're going to come up
and think about what
our next steps are to try to
get a bite here on this model.
VALERIA: Copy that.
Let's pull her in.
VALERIA: So we're
bringing Gooey in.
Her silhouette looked
really good underwater,
but sharks used multiple
senses to detect prey,
so we're going to add a little
something to see if we can
entice them to bite Gooey.
One two three, pull.
NARRATOR: The team has one
more trick up their sleeves
to try and get a
shark to bite Gooey.
MIKE: Gooey almost looks real
when you're far enough below.
We had the sharks around,
but they didn't really show
any interest in the dolphin.
VALERIA: We know sharks don't
bite every single dolphin,
so we need to add
something to entice them.
MIKE: What I think we should
do is strap a bit of bait
down here. Then when the
sharks come in at the bait,
they try to grab the bait,
and they're going to grab
Gooey as well right
in an area
where we see bites on a
lot of wild dolphins.
NARRATOR: The team
attaches bait to the area
where they've seen many
bite scars, the peduncle,
to see if a bite here will
match what they've seen
on the wild dolphins.
VALERIA: The peduncle is
a really strong muscle
at the tail end of the
dolphin, and it allows them
to move their tail really
fast, it allows them
to maneuver, and get
to great speeds.
KEL: The peduncle is
where the dolphin's
power is for swimming.
If it gets a serious
enough injury or if the
spinal cord is severed
or damaged, then
that dolphin might become
incapacitated, giving the
shark a second chance
to come in for the kill.
MIKE: Echolocation and
vision, most of that
for the dolphin is
directed forward.
So coming from below and
behind is the easiest way
to sneak up and make
that ambush attack.
As the sharks come in
to get a bit of food,
they're going to bite
the dolphin model,
and we'll get those really
nice tooth impressions
once they've bitten in.
VALERIA: Definitely,
adding the bait, that extra
scent will really entice
the sharks to bite Gooey.
Ready. Let's do this.
NARRATOR: Gooey not
only looks good,
she smells good too.
MIKE: We've got one
coming in!
A shark coming up from this
angle from below and behind.
That dolphin is in
big trouble.
There's definitely sharks
more interested now
that there's some
fish on Gooey.
VALERIA: It's coming
in close.
We definitely have
their attention.
MIKE: They're
going right for it!
Look at that.
(Excited screams)
Yes! That is exactly
what we wanted.
Let go now please.
Man that bull shark
just nailed Gooey.
VALERIA: Whoa, look at that.
MIKE: It's incredible,
isn't it?
You can see where each
tooth just traces through,
even the serrations
on the teeth.
VALERIA: This could have
definitely been fatal.
MIKE: Oh yeah, it
almost nicked the spine.
There's too much vital there.
This dolphin would have
bled out, and the shark
could have come back later
to finish it off.
VALERIA: Good job, Gooey.
Let's pull it up.
MIKE: It's pretty incredible
just how much that shark
got out of Gooey. I mean.
That was probably 20 pounds
of gelatin. That was
a stunning success.
It actually simulated real
life more than we would've
thought because Gooey was
kind of listing to the side.
And if a dolphin
sees a shark coming,
it's going to turn its
back to it to try
to maneuver away. And
so the shark came
straight from the bottom
up and bit here.
It would've gone right next
to the spine and you can see
a nice clean cut, and so
an 8.5-foot bull shark,
no problem killing
a dolphin.
Gooey really taught
us a lot.
From just one bite we were
able to see that even
with this big round object
a bull shark leaves
a clean bite not
a ragged one.
With the 3D-scan were we
able to see how each tooth
moved through and that these
bull sharks are leaving
clean bites even on big
round dolphins and it really
showed us that it's going to
take a big adult bull shark
to take down a dolphin.
Evolution tends to hone
behaviors that make
predators super-efficient, and
prey good at getting away.
For dolphins, if they
aren't paying attention
and good at avoiding
predators, they're not going
to leave many calves in
the next generation.
And so that arms race between
predator and prey is going
to continue for sharks
and dolphins.
NARRATOR: The evidence
collected with the bite pads
and dolphin decoy suggests
that hammerheads,
tiger sharks and bull sharks
could all be responsible
for the bites seen
on dolphins here.
And still, the battle of
The Bahamas between
some of the best designed
and most intelligent species
in the ocean rages on.
KEL: The fact that there
are so many sharks
and so many dolphins in the
Bahamas might be a really
good sign for the health
of the oceans here.
You have food all year
round, mates all year round
and even when a dolphin
gets bit by a shark,
if it's lucky
enough to get away,
it's healthy enough to
survive that attack.
VALERIA: This clash
between the predators,
there's no winners
or losers.
It's just the opportunity
to catch a prey.
MIKE: We have great
hammerheads, we have
tiger sharks, we have bull
sharks, all in this one spot
and there're dolphins
there too.
This battle between sharks
and dolphins in the Bahamas
isn't going to end.
Captioned by
SubTitlePro LLC
Bahamas are a battleground.
In the war between sharks
and dolphins.
Using photographic evidence.
MIKE: One species that might
cause that kind of bite
would be a bull shark.
NARRATOR: Specialized
bite pads.
MIKE: It went through this
simulated dolphin blubber
like butter.
NARRATOR: And, for
the first time ever,
a decoy dolphin as
their secret weapon.
These biologists will
attempt to uncover
which sharks are
the culprits.
MIKE: That dolphin
is in big trouble.
They're coming right for it!
Yes!
NARRATOR: Shedding new light
on these two apex predators,
locked in deadly
underwater combat.
BOATER: Hey, they're
fighting they're fighting.
Oh!
He's got a dolphin in
its mouth!
It's right under us.
Look at the size of
the thing.
NARRATOR: A bloody
battle, as old as time,
is being waged
beneath the waves.
Shark versus dolphin.
One of the front lines
for this oceanic clash
is located 55 miles
off of Florida.
Bimini is part of 700 islands
that make up The Bahamas.
Nearly one third of
dolphins here show signs
of shark attack.
A team of shark and dolphin
researchers is here
to discover what sharks are
targeting these dolphins,
the Atlantic Spotted Dolphin
and the sleek grey Bottlenose.
KEL: We've got
dolphins on the bow.
VALERIA: Wow, look
at them ride.
NARRATOR: Dr. Mike Heithaus
is a shark specialist
and a Dean at Florida
International University.
He's joined by Dr. Valeria
Paz, a dolphin expert,
and local Bahama
dolphin researcher
Kel Melillo Sweeting.
First part of the mission:
photograph the scars to
match them to the predators.
VALERIA: Hey, Mike. Did
you see that notch
on that dorsal fin?
MIKE: Yeah. You know
that couple notches there,
yeah, that's the kind of
injury that could be caused
by a shark.
KEL: Two mother-calf pairs.
One of them had a
distinct shark bite scar.
She actually got that
injury as an older calf,
younger juvenile.
So what we're seeing
now is a few years old,
really well-healed scar.
VALERIA: She came really
close, so I was able
to get some really
good footage.
NARRATOR: While foraging,
some dolphins occasionally
break away
from the pod to crater feed.
Turning upright,
using their nose,
or rostrum to dig
and find prey.
This is when the dolphins
are most vulnerable.
KEL: They have to remain
vigilant because a shark
could be around at
any moment.
We're also seeing signs of
previous shark attacks.
One bottlenose dolphin had
both pectoral fins injured.
MIKE: Here in the Bahamas,
you can find more
than a dozen species
of sharks.
But it's most likely the
ones attacking dolphins
are the bigger bull
sharks, tiger sharks,
and maybe great hammerheads.
These are the top
predators here.
What a great snorkel.
A couple mom-calf pairs.
There was one that it
looked like had a bite
on the peduncle there.
KEL: Yes. Maybe a shark
sneaking up from behind?
MIKE: Hopefully the
pictures will help.
KEL: Yes.
NARRATOR: With so many
large sharks in this area,
the dolphins have a lot
of possible predators.
VALERIA: This bite is
definitely on the side
of the flank so maybe
it was trying to escape
or evade when it turned
and then it got bit.
MIKE: Yeah, you see it's
a pretty broad bite.
One other species that
might be able to do that
something like the
tiger shark,
they just have that big wide
head compared to other sharks.
And then their teeth
are really different.
You've got similar sized teeth
in the top and bottom jaws.
Instead of being
for puncturing
they're really meant
for cutting.
And you've got really fairly
long distances between the
teeth, so that should
give us some clues.
KEL: This is a
bottlenose dolphin,
took this photograph right
around Bimini and you can see
it has a pretty fresh
injury to its back here.
VALERIA: That's fairly
sizeable.
MIKE: Yeah and it's
super clean too,
so not a lot of diagnostics
there and one animal
that could do that around
here is the bull shark.
This is a replica jaw, you
can see that's a big mouth
but with a clean bite a
really big great hammerhead
might be able to leave
a mark like that.
Now we just need to get
impressions of shark bites
so we can get a sense
of how they're holding
and gripping and releasing
the prey and what that
would look like on a dolphin.
NARRATOR: There are 10
types of hammerheads,
but here in Bimini, the
team sets out in search
of the great
hammerhead to see
how it might be biting
these undersea mammals.
Up to 20 feet Long, as large
as a fully grown great white,
these giants congregate in
the shallows off Bimini.
MIKE: These great
hammerheads are huge sharks.
They have speed,
maneuverability
and the teeth in the upper
and lower jaw are different.
You get kind of cutting teeth
on the top and gripping
teeth on the bottom.
So it's possible that great
hammerheads are taking out
dolphin calves and if they get
one of those in their mouth,
it's going to be really hard
for that dolphin to get away.
NARRATOR: Mike and
Valeria want to see
what great hammerhead bites
look like on prey to compare
with the scars they've
photographed on the dolphins.
Local shark diver Neal
Watson has been working
with hammerheads here
for more than a decade.
He's going to help the
team get a bite impression.
NEAL: Today we're going to
try and feed a whole bonito
to one of the hammerheads
and the key difference
is we're going to try and
actually get it back.
It's something unique
that we don't do usually
but I think we'll be
able to give it a shot.
MIKE: When we're gearing
up to dive with sharks,
I'm really always running
through worst possible cases
in my head, because you
got to be prepared.
I'm always thinking
about, okay,
if a shark is aggressive,
what are we going to do?
Where am I going to be
relative to Valeria?
What am I going to do
if a shark comes around
from behind? You have to be
really, really vigilant
whenever you're dealing
with large, potentially
dangerous animals.
Great hammerheads
don't attack humans,
but we're going to see how
they feel about visitors.
NARRATOR: The smell of fish
may entice the hammerhead,
but also bring in other
species of sharks.
VALERIA: Tiger shark and I
think I see some bull sharks
coming in.
NARRATOR: Tiger sharks and
bull sharks are ambush
predators, known to
sneak up on their prey,
so the team stays on
high alert waiting
for the great hammerheads.
VALERIA: Those nurse sharks
are definitely coming
to check us out.
And although their
jaws might seem small,
once they bite onto something,
they really hold on.
MIKE: We have to keep
this fish away from them
or we might not get it back.
NARRATOR: Finally, the great
hammerhead approaches,
and her size lives
up to the name.
VALERIA: Wow, that
is a beautiful shark.
Probably about 12
feet or more.
MIKE: Yeah, that's
a large female.
Definitely big enough
to eat a dolphin.
This hammerhead
seems interested.
VALERIA: Hey Mike,
tiger shark behind you.
MIKE: Here she comes!
Oh man she's trying
to swallow it whole.
Well, there goes one bonito.
VALERIA: We've got
another hammerhead.
MIKE: We've got to get the
hammerhead to let go of
that fish.
Looks like the hammerhead
is coming back around
for another go.
Okay, let it go, let it go!
VALERIA: Yes, you got it!
MIKE: Let's get
this up to the boat.
What an incredible dive.
VALERIA: That was unbelievable,
those hammerheads.
The size of that one.
Must have been 12
to 14 feet maybe?
MIKE: Definitely capable of
taking out a spotted dolphin,
maybe a bottlenose
dolphin juvenile.
VALERIA: I'm excited
to see that fish.
MIKE: Well, after all that
we got one bonito head back.
VALERIA: Definitely
scraped all the skin out.
MIKE: Yeah. It's not
a clean cut
by any means and bonito
is not a dolphin
but I guess if that was a
hammerhead biting a dolphin
you wouldn't expect
something clean.
It would probably be more
scrapes through the tissue.
NARRATOR: The tearing bite
of the hammerhead matches
the ragged scars seen
on the dolphins.
VALERIA: That's
definitely what we saw
when the hammerhead was
approaching the fish
and it grabbed it
and kind of teared.
It was not a clean cut.
MIKE: No. So. We didn't
get tooth impressions
like you might hope for
but it's some
first clues.
For the sharks and
dolphins here off Bimini,
they're pretty
well-matched adversaries.
The sharks, body size,
strength, cutting teeth.
And the dolphins live in
groups, they're smart,
and they're super-fast
and maneuverable.
NARRATOR: To observe just
how intelligent dolphins
are Mike and Valeria
head to the Clearwater
Marine Aquarium in Florida.
All of the dolphins here
are injured or unable
to survive in the wild and
cannot be released.
Animal care specialist
Katie Wojdyla provides
daily enrichment.
KATIE: Right now I'm doing
what we call face time
and all it is is a
little playtime,
it's offering them
any interaction
if they would like it.
We have right here in
front of you is Hope.
She's currently 11 years old.
She really seems to
enjoy water play.
NARRATOR: Animal care
specialist Brooke Bowersox
has seen the damage
sharks can do first hand.
BROOKE: This is PJ, you can
see that she has a nice scar
back there on her peduncle.
MIKE: Yeah, and that just
looks like a fresh bite
that we see on dolphins
like the ones in Bimini.
You see that's
not the only scar,
there's also places where it
looks like the jaws come over.
VALERIA: Since the
scar healed so well,
it's really difficult
to tell what species
could've made that.
MIKE: Yes, a bull, tiger
even great hammerhead,
you just can't tell
from that healed wound.
NARRATOR: To avoid attacks,
dolphins have an arsenal
of defenses, including
intelligence.
With brain mass larger
than any shark's,
dolphins are second only
to humans in brain
to body weight ratio.
Making it easy for them
to outsmart sharks.
But they also have a secret
weapon to evade predators:
echolocation.
MIKE: Echolocation is
really kind of a dolphin's
superpower.
VALERIA: Dolphins emit sound
and they have a part of
their head that is
called the melon.
This area receives
the sound waves,
and it translates
to what's going on
in their surroundings.
It allows them to navigate
without using sight.
NARRATOR: Echolocation
helps dolphins find prey
or detect predators.
MIKE: We're going to do an
experiment to figure out
how we can use echolocation
or how effective it is,
but first we've got to let
him use all his senses.
What are we going to do?
BROOKE: Yeah.
So this is a cognitive concept
called the match to sample.
What we're going to do is
we're going to show Nicholas
this buoy and then we're
going to ask him to go across
to the other side of the
pool where there's three
different sample items
and ask him to select
which one matches what
he's seeing here.
And you can see that
he got it right.
MIKE: He did pretty
well at that last one,
but now it's time to
turn out the lights
and just do echolocation.
How does this trial work?
BROOKE: So what we're
going to do now
is we're going to place eye
cups over Nicholas' eyes
and Bree is going to send
him over to our right
with Katie is, where he's
going to echolocate
on that red boat.
Once he echolocates on it,
he's going to travel over
to where our samples are
and they have those samples
under water. So using
his echolocation,
he can make the
correct selection.
MIKE: You see just
no hesitation.
No worry about having his
eyes, just echolocation
straight there.
BROOKE: Correct.
VALERIA: And he did.
MIKE: It's incredible.
So, this really just
shows how impressive
that echolocation is.
Also shows how smart they
are and that smarts
and echolocation help them
survive out in the wild,
including avoiding sharks.
BROOKE: Absolutely.
NARRATOR: Back in The Bahamas,
Mike and Valeria believe
hammerheads could be
responsible for some
of the ragged bite scars
they've photographed
on dolphins.
But they want to
investigate another shark
that may be a predator.
And this one is second
only to the great white
in the number of
attacks on humans.
Tiger sharks.
Growing up to 18 feet,
weighing nearly a ton
they'll eat just
about anything
from tires to turtles.
BOATER: No way.
NARRATOR: To dolphins.
New South Wales, Australia.
Off the coast of Newcastle,
a tiger shark goes in
for the kill.
A lone dolphin is no match
for the 11-foot tiger shark.
It disables its tail and the
dolphin is dead in the water.
MIKE: Tiger sharks are
incredible predators.
They also have teeth that are
curved and have serrations,
so they cut in
both directions.
So once they grab
onto something,
they can shake their
heads back and forth
and cut straight through it.
NARRATOR: And there's no
place better to find tigers
than Tiger Beach,
in The Bahamas.
The team will try to get
bite impressions
from the tiger sharks and
study the tiger's feeding
style to compare that with
their photos of dolphins
with shark attack scars.
Underwater cinematographer
Duncan Brake has been diving
these waters for
more than a decade.
Neal Watson will be using
whole bonito again
to get a bite impression.
Immediately, the team is
met with an eager
group of tiger sharks.
MIKE: We want to get a tiger
shark to bite the bonito
to examine how it uses
those serrated teeth.
We've got one heading in.
VALERIA: There's a lot of
lemon sharks coming in, too.
MIKE: Lemon sharks don't have
much sense of personal space
and they can be aggressive
eaters, so let's keep
the bait away from them.
NARRATOR: The lingering smell
of the bonito fish starts
to catch the
sharks' attention.
Two tigers approach.
MIKE: We usually think of
tiger sharks as solitary
animals, but this fish
has caught the interest
of more than a couple.
VALERIA: This one's
definitely interested.
MIKE: Come on! Hold on! Yes!
NARRATOR: Neal manages to
hold on to part of the fish.
MIKE: Let's get
up to the surface.
VALERIA: That was incredible.
Such large animals.
MIKE: No shortage of sharks.
NEAL: None.
MIKE: And I think we're
going to need bigger bonito
next time.
NEAL: Yeah.
These are big three-foot
bonitas but they're kind
of a one-bite meal for
these tiger sharks.
I was able to wrestle
this piece away.
I think it was indicative
how they were feeding.
They would grab the bait and
if they only got a little bit
of it they would let go
momentarily to try
and get a little bit closer
and I was able to pull it out.
MIKE: And that's what you see
on the dolphins sometimes.
It's not just always a clean
bite in but it looks like
there's bite and slash
release bite again.
And that's kind of what you
see here on that bonito.
VALERIA: Yeah. That's
definitely similar
to the scars that
Kelly showed us.
NARRATOR: The tiger sharks'
slashing bite matches
what the scientists saw
on the dolphins.
KEL: For a shark, a
dolphin is no easy meal,
but is a really rich meal.
Lots of meat, lots of blubber.
But the dolphins have
evolved to fight back.
MIKE: Once dolphins
have seen a shark,
it's kind of the game's
up for the shark,
it's not going be successful
and the dolphins will
actually kind of chase
and herd sharks away.
There's one video where a
juvenile great white shark
approaches a group of
dolphins and one dolphin
peels off and just
chases that shark away
and the sharks just
kind of, "Forget it.
It's not worth it,"
and it heads out.
These dolphins are not just
swimming snacks for sharks,
they can detect sharks and
kind of hold their own.
NARRATOR: Dolphins have
one more advantage:
the ability to communicate
with one another.
VALERIA: Dolphins are
definitely chatty
and they use sound
to communicate,
and it's really important
to their everyday life.
KEL: We're observing some
Atlantic spotted dolphins
and we're going to use
this hydrophone,
an underwater microphone,
to hear the sounds
through the headphones and
hear their whistles, squeaks,
squawks, chirps.
Vocalizations are super
important to dolphins,
to help keep track of
the group, find food,
possibly even alert each other
to predators like sharks.
NARRATOR: Even with
echolocation and the ability
to communicate, dolphins in
The Bahamas are still
under siege.
The team concludes
that the ragged scars
they've seen on the dolphins
could be from tiger sharks
and hammerheads.
But many of the scars they
photographed were cleaner
and more defined.
Could there be a third species
of shark attacking dolphins?
Bull sharks have the greatest
bite force of any shark
relative to their body size.
Could they be responsible
for preying on dolphins?
They prowl the shallow seas,
using the sandy bottom
and murky water to
conceal their attack.
Both dolphins and humans
never see them coming,
until, it's too late.
MIKE: Here in Bimini,
the bull sharks
and the dolphins are often
hunting in the same areas,
and that can include
murky waters.
The bull sharks are probably
mainly hunting for smaller
things, but if they get a
chance to grab a dolphin,
they're going to take it
because that dolphin
represents an incredible
meal with all the fat
and energy in the blubber.
NARRATOR: The team needs
a bite impression
from the bull shark to compare
to the dolphin scars.
But this time they'll
attempt something
that's never been
done before.
They're creating a
life-sized dolphin decoy,
but first they need to
test out the material
they'll be using to
make the dolphin,
while also collecting
more bite data.
MIKE: This is basically
a gelatin block
that is the density
of dolphin blubber
and we've turned it into a
giant underwater lollipop.
So what we'll do is put a
little bit of fish on this
to entice a shark to bite.
And when they bite it,
it's going to give us
a jaw impression.
NARRATOR: They head to the
waters between Florida
and Bimini.
MIKE: This is the
perfect place to come
to find bull sharks. There's
lots of food here,
the water temperatures
are right
and it's a known spot where
groups of bull sharks
get together.
NARRATOR: While
Mike gets the bite,
Valeria will be on
shark measuring duty.
A laser device can
pinpoint the exact length
of the shark.
MIKE: Bull sharks have a
reputation as a more
aggressive species, but they
usually don't bother divers.
But we do have bait
on the pad here,
so we've got to stay alert.
VALERIA: Copy that.
A couple of bull
sharks are coming in.
I'm going to get
some measurements.
They look definitely the size
that would attack a dolphin.
MIKE: They're
interested in the fish,
but they're being cautious.
VALERIA: They're definitely
curious, just not biting.
MIKE: Wait. This one's
coming back around.
VALERIA: Watch out,
your hands!
MIKE: Didn't even see it.
(bleep)
I count three bull sharks.
They're all more
than 6 feet long.
I'd say they're big enough
to attack a dolphin.
We just need to get
one to bite this pad.
Oh, that was close!
VALERIA: We need a good bite
and the size of the shark,
to compare it to the bite
marks on the dolphins
in Bimini.
MIKE: Wait a minute.
I think we have
another taker!
I can't hold it!
VALERIA: That bull's coming
right back around Mike.
MIKE: Get the lasers ready.
VALERIA: Yes, we got it!
MIKE: Look at that.
Oh, this is incredible.
You just see the
width of that bite,
it just bit on and went
through this simulated
dolphin blubber like butter.
You can see why dolphins
just lose big chunks
if a big shark gets a hold
of them, and that one,
we got a really
nice laser hit on.
So we'll know exactly
how big the bull shark
was that did that.
And we got a bonus. This
shark left a tooth behind.
They lose so many
teeth in their lives.
They're constantly
shedding. So
a loose tooth, even in dolphin
blubber can get stuck.
Usually, we're not so lucky
to have them left behind.
A nice bite width there
on a real-world situation.
So this is exactly what
we wanted, I am psyched.
NARRATOR: The bite pad
reveals that the ragged bite
marks from the photos
were probably not caused
by the bull shark.
The precise incision on the
pad could mean bull sharks
are the ones leaving
the cleaner scars.
But there's another way
to find out whether
these bull sharks
have attacked
the underwater mammals.
MIKE: Right now we're trying
to catch a bull shark.
We got a piece of bonito
on a small circle hook
so we can throw it to the
bull shark that we want,
catch it, get it up, and see
if it's eaten a dolphin.
NARRATOR: In sharks, the
reproductive and digestive
systems come together at
a common area called
the cloaca, so the team will
take a sample from this area.
VALERIA: So here's
the swab kit.
We're going to be using the
cotton swabs to get fecal
matter from the bull shark
and that will tell us
a little bit about what
they have been eating.
That is going to be really
useful to see if we see
any dolphin DNA in
this fecal matter.
MIKE: First, we
have to catch one.
Handling sharks can
be really dangerous
if you're not careful and
that's especially true
for bull sharks.
They got that big
mouth, sharp teeth,
but the tail is
incredibly powerful.
So you've got to always be
aware of your surroundings
and work together as a team.
There we go.
Okay there's a bull
shark right below us.
VALERIA: See it.
MIKE: They're right
next to it.
Yes, it's on, it's
on it, it's on it.
VALERIA: Oh. Nice.
MIKE: Okay now I need
everybody to be beyond
careful right now.
-Yeah.
Right down there. It's a
good sized one for sure.
Watch your feet,
watch your feet.
That is a big bull shark.
VALERIA: Oh. It's a big one.
MIKE: Fresh shark, the
trick now is to hold on
as much as you can.
Ah!
That is definitely big
enough to attack a dolphin.
No question.
Okay. Get ready.
I'll start back further,
try to bring it around.
Well, we're trying to get a
tail rope on it so we get.
VALERIA: I got you. I
got you. I got you.
MIKE: Slow, slow, slow,
you're good, you're good,
you're good. Nice and easy.
Oh close.
Okay. Excellent.
Okay. Good job. Okay.
Now, we've got control of the
animal, so now, cleat that off.
A little bit lower.
A little bit lower,
so its tail's kind
of in. Good.
NARRATOR: But just as they're
about to tie the shark off.
MIKE: Oh no, look out, look
out, clear clear, clear!
Look out. Careful. Careful.
No, do not grab this.
It popped the monofilament.
NARRRATOR: They've lost
control of the most
dangerous part of the
shark, its jaws!
MIKE: Back off! Back off!
MIKE: Agh!
No, do not grab this.
It popped.
We had the shark actually drop
when there was a swell and it
popped that monofilament, so
we're just going to do a quick
repair on the fly, so we have
control of the animal here.
I need another roundy.
I'm going to tie into this,
and get the crimping tool.
VALERIA: I got it.
MIKE: We've got to
write down the lengths.
Mark that, 216.5.
VALERIA: 216.5.
MIKE: 252. That's about 8
and a half foot Bull Shark.
That's definitely big enough
to go after a dolphin. Okay.
Get the cloacal swab kit.
VALERIA: Yup.
We are going to be opening up
the swab kit and making sure
that everything is set
up for the cloacal swab.
Make sure this is up so
that it's out of the water.
MIKE: Okay.
VALERIA: All right.
MIKE: Great job.
That's perfect.
VALERIA: Here we
have the vial.
We're going to go ahead
and place it in here
and make sure to label it
and we'll send it out to
the lab to find out what
sharks have been eating.
MIKE: Okay, we can
release any time.
NARRATOR: Releasing an angry
shark is even more dangerous
than catching it.
The crew has to be careful
not to get caught
in the lines as it thrashes.
MIKE: Look out.
Okay. Hang on. Hang
on, hang on.
Are we ready?
here we go. Three, two. One.
Great, great. Good job.
That was great.
We got that shark up, tag
in, cloacal swab done,
and a great release.
The cloacal swab showed us
these bull sharks hadn't
eaten a dolphin recently,
but that doesn't mean
they're not dolphin
predators.
It just means they're not
eating them all the time.
NARRATOR: The cloacal
swab was inconclusive
but the bite pad shows that
bull sharks could be the ones
making the clean bites
seen in the photos.
Mike and team are now ready
to deploy their nearly
200-pound secret weapon.
They want to get an even
more realistic view of what
a bull shark bite would look
like on a real dolphin.
MIKE: This is Gooey, our
dolphin model and Gooey
was made out of
non-toxic gelatin.
We want to make sure if a
shark gets a mouthful
of Gooey, it's completely
harmless to the shark.
Gooey was made so that the
consistency is exactly
like that of dolphin
blubber.
And it's pretty much the same
size as an Atlantic spotted
dolphin in Bimini or
a juvenile bottlenose.
NARRATOR: This is the
first time a dolphin decoy
made of non-toxic
materials will be used
in shark research.
MIKE: The bite-pads
were a great first step,
but they're just kind
of a fairly narrow pad
and so a shark might bite
that very differently
than something that's
shaped like a dolphin.
It's rounded and in some
places it's so big
that it's kind of like
trying to palm a ball
that's too big for a shark
trying to bite it.
So we have created something
completely unique,
a gelatin dolphin.
NARRATOR: It's sink or
swim time for Gooey.
The team takes her to an
area known for bull sharks.
They're joined by underwater
cameraman Sean Havas,
who will capture this
"first" in shark research.
MIKE: As soon as Sean and
I are in let's get Gooey
in right next to us.
VALERIA: You got it.
I'll be looking at you
guys for directions.
Once I put it in if you need
me to give it some life.
MIKE: We'll let you know
but hopefully Gooey
will do its job.
VALERIA: We're strapping a
camera onto Gooey to get
a better angle.
We're positioning it so that
it faces the peduncle area
where we think sharks may
be more enticed to bite.
Mike, should we deploy
Gooey?
MIKE: Ready for Gooey.
VALERIA: Copy. We'll deploy.
You got it Mike.
NARRATOR: Deploying this
enormous dolphin decoy
takes teamwork.
VALERIA: Kirk,
look at the camera.
Make sure it's at the right
angle when it gets deployed.
Lucas, make sure that the
pectoral fins are not getting
stuck by the ladder,
and let's do this.
All right. Please
clear the deck.
One, two. Slide.
MIKE: All right.
Gooey's swimming.
VALERIA: Mike, what are
you seeing down there?
MIKE: Well, right now,
it's pretty lonely.
Just hanging out with
Gooey. No sharks yet.
So hopefully, we get
some interest soon.
VALERIA: Gooey right now
doing a natural behavior.
This is called logging.
Logging is when
they're resting and there
may be more vulnerable
during this behavior.
MIKE: We got Gooey exactly
where we need it to be.
It looks so real!
VALERIA: Gooey is of similar
size of those dolphins
that we saw in Bimini.
Although her colorations
are a lot different,
the silhouette
from below mimics
that of a real dolphin.
NARRATOR: Sharks are
attracted to contrast.
They may not see color,
but this silhouette
should lure them in.
If one attacks, Mike will not
only get a bite impression,
but the exact size
of the shark.
They'll be able to record
if smaller juvenile sharks
might attack a dolphin,
or is it mostly
the larger mature sharks.
MIKE: The idea is, we want
to get length on the shark
that attacks Gooey so we
know not just what species
grabbed the model, but
how big it was.
NARRATOR: The bull
sharks arrive.
And it's time to put
Gooey to the test.
Will she be a trick or
treat for the bulls?
MIKE: These are big
bull sharks.
They are definitely a
threat to the dolphin.
We've got four sharks,
they're circling
but we're not seeing a whole
lot of interest right now.
Try giving Gooey some motion.
VALERIA: Copy Mike, will
give it some movement.
Kirk, can you please
give it some motion?
MIKE: No. Still
not interested.
That's not terribly
surprising since bull sharks
probably only very, very
occasionally attack
dolphins that they see.
She looks like a dolphin and
kind of moves like a dolphin.
Maybe we need to add
some smell.
Sharks have an incredible
sense of smell.
They can smell a couple of
drops of blood in a swimming
pool worth of water.
That means that if there's
a good scent trail,
they can follow it for miles.
Now one is starting
to move toward it.
Come on! No. Okay.
We may have to do a
bit more than this.
We're going to come up
and think about what
our next steps are to try to
get a bite here on this model.
VALERIA: Copy that.
Let's pull her in.
VALERIA: So we're
bringing Gooey in.
Her silhouette looked
really good underwater,
but sharks used multiple
senses to detect prey,
so we're going to add a little
something to see if we can
entice them to bite Gooey.
One two three, pull.
NARRATOR: The team has one
more trick up their sleeves
to try and get a
shark to bite Gooey.
MIKE: Gooey almost looks real
when you're far enough below.
We had the sharks around,
but they didn't really show
any interest in the dolphin.
VALERIA: We know sharks don't
bite every single dolphin,
so we need to add
something to entice them.
MIKE: What I think we should
do is strap a bit of bait
down here. Then when the
sharks come in at the bait,
they try to grab the bait,
and they're going to grab
Gooey as well right
in an area
where we see bites on a
lot of wild dolphins.
NARRATOR: The team
attaches bait to the area
where they've seen many
bite scars, the peduncle,
to see if a bite here will
match what they've seen
on the wild dolphins.
VALERIA: The peduncle is
a really strong muscle
at the tail end of the
dolphin, and it allows them
to move their tail really
fast, it allows them
to maneuver, and get
to great speeds.
KEL: The peduncle is
where the dolphin's
power is for swimming.
If it gets a serious
enough injury or if the
spinal cord is severed
or damaged, then
that dolphin might become
incapacitated, giving the
shark a second chance
to come in for the kill.
MIKE: Echolocation and
vision, most of that
for the dolphin is
directed forward.
So coming from below and
behind is the easiest way
to sneak up and make
that ambush attack.
As the sharks come in
to get a bit of food,
they're going to bite
the dolphin model,
and we'll get those really
nice tooth impressions
once they've bitten in.
VALERIA: Definitely,
adding the bait, that extra
scent will really entice
the sharks to bite Gooey.
Ready. Let's do this.
NARRATOR: Gooey not
only looks good,
she smells good too.
MIKE: We've got one
coming in!
A shark coming up from this
angle from below and behind.
That dolphin is in
big trouble.
There's definitely sharks
more interested now
that there's some
fish on Gooey.
VALERIA: It's coming
in close.
We definitely have
their attention.
MIKE: They're
going right for it!
Look at that.
(Excited screams)
Yes! That is exactly
what we wanted.
Let go now please.
Man that bull shark
just nailed Gooey.
VALERIA: Whoa, look at that.
MIKE: It's incredible,
isn't it?
You can see where each
tooth just traces through,
even the serrations
on the teeth.
VALERIA: This could have
definitely been fatal.
MIKE: Oh yeah, it
almost nicked the spine.
There's too much vital there.
This dolphin would have
bled out, and the shark
could have come back later
to finish it off.
VALERIA: Good job, Gooey.
Let's pull it up.
MIKE: It's pretty incredible
just how much that shark
got out of Gooey. I mean.
That was probably 20 pounds
of gelatin. That was
a stunning success.
It actually simulated real
life more than we would've
thought because Gooey was
kind of listing to the side.
And if a dolphin
sees a shark coming,
it's going to turn its
back to it to try
to maneuver away. And
so the shark came
straight from the bottom
up and bit here.
It would've gone right next
to the spine and you can see
a nice clean cut, and so
an 8.5-foot bull shark,
no problem killing
a dolphin.
Gooey really taught
us a lot.
From just one bite we were
able to see that even
with this big round object
a bull shark leaves
a clean bite not
a ragged one.
With the 3D-scan were we
able to see how each tooth
moved through and that these
bull sharks are leaving
clean bites even on big
round dolphins and it really
showed us that it's going to
take a big adult bull shark
to take down a dolphin.
Evolution tends to hone
behaviors that make
predators super-efficient, and
prey good at getting away.
For dolphins, if they
aren't paying attention
and good at avoiding
predators, they're not going
to leave many calves in
the next generation.
And so that arms race between
predator and prey is going
to continue for sharks
and dolphins.
NARRATOR: The evidence
collected with the bite pads
and dolphin decoy suggests
that hammerheads,
tiger sharks and bull sharks
could all be responsible
for the bites seen
on dolphins here.
And still, the battle of
The Bahamas between
some of the best designed
and most intelligent species
in the ocean rages on.
KEL: The fact that there
are so many sharks
and so many dolphins in the
Bahamas might be a really
good sign for the health
of the oceans here.
You have food all year
round, mates all year round
and even when a dolphin
gets bit by a shark,
if it's lucky
enough to get away,
it's healthy enough to
survive that attack.
VALERIA: This clash
between the predators,
there's no winners
or losers.
It's just the opportunity
to catch a prey.
MIKE: We have great
hammerheads, we have
tiger sharks, we have bull
sharks, all in this one spot
and there're dolphins
there too.
This battle between sharks
and dolphins in the Bahamas
isn't going to end.
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