♪ ♪
MATT (off-screen): This is the graveyard of the Atlantic.
So there's a lot of wrecks nearby.
And one of the wrecks is the Papoose.
I would have never believed what happened if I didn't see
it with my own eyes.
We were expecting some grouper to be on the wreck that
we could shoot spearfishing.
Ready to go get some grouper?
MAN: I’m ready. MATT: Let’s do it.
♪ ♪
Nothing abnormal, just another wreck with hopefully
something to eat.
There was quite a few grouper hanging out.
(thuds).
MATT (off-screen): I was lucky enough to spear one.
But I didn't know the big sand tiger was there at that point.
Sand tigers look really menacing underwater but
they're generally, they're really docile sharks.
MATT: Shark!
MATT (off-screen): But the size of the shark was pretty impressive.
I wouldn't say I was scared,
but it definitely had my full attention.
I figured that it's kind of just like another big guy at a bar.
Like, how are we going to work this out?
We're both here to have a good time.
So you give them their space,
they kind of give you your space.
And that's normally what happens.
But instead, I shot another grouper.
(thuds).
MATT (off-screen): Which then caused this whole chain reaction of events.
(bleep).
The next thing you know, there was three or four sand tigers,
that came out of nowhere.
It's like a switch went off.
The danger level was increasing.
You could feel that we were really no longer wanted
on that wreck.
I wouldn't say I was scared,
but we wanted to get out of that situation.
♪ ♪
I feel very lucky that I had a buddy with me and
I'm very happy both of us got out of the water unharmed.
NARRATOR: The Matt Wirt attack isn’t the first time divers have
sparred with sharks on a shipwreck.
Terrifying encounters are happening near these
man-made structures across the globe.
Now, investigators wonder,
what draws these fearsome predators to shipwrecks,
and entices them to attack?
(theme music playing).
NARRATOR: Shark scientist Ryan Johnson notices
the alarming trend.
RYAN: Diving on wrecks has become more common recently,
particularly for scuba divers.
So, at those locations, encounters between sharks
and divers have become more abundant.
NARRATOR: After reviewing the footage of Matt Wirt’s near-miss,
Ryan explores a theory that may explain why
the sand tiger charges Matt and his friend.
It’s possible that the sand tiger is deliberately using
the shipwreck as part of its hunting strategy.
RYAN: A lot of sharks will use different structures as camouflage.
And then when an unsuspecting prey comes passed,
they do this really high-speed ambush attack.
So, the entire strategy plays a massive role in
this success as apex predators.
NARRATOR: The theory has profound implications.
If sharks use shipwrecks for ambush hunting,
these underwater structures could present a massive threat
to anyone swimming nearby.
RYAN (off-screen): There are thousands of these artificial wrecks
all over America, all over South Africa,
so it would be really important for us to observe and
understand how these sharks are using these wrecks
as hunting grounds.
NARRATOR: Off the North Carolina coast,
researchers are doing just that.
Doctor Avery Paxton and her team of NOAA researchers study
the wrecks off North Carolina.
AVERY: The coast of North Carolina is
the final resting place for hundreds of shipwrecks.
And so in order for us to understand how these
human made structures function ecologically,
one of the things that we look at is how fish use these sites.
Including the large predators like sharks.
NARRATOR: To get eyes on the wrecks,
Avery and her team utilize multiple methods.
They dive, often a dangerous journey more than 100 feet down.
And they deploy underwater drones,
a low impact tool that can peek into
the wreck’s many hard-to-reach places.
AVERY (off-screen): Our research is pretty mysterious,
we never know what we're going to find when we get eyes underwater.
Sometimes you descend down to the wreck and
there are no sharks anywhere in sight.
Other times, our team has spotted over 200 sharks on
some of these small islands of habitat.
NARRATOR: Avery and her team spend hundreds of hours
observing these swarms of sharks.
What they witness might help validate
the hide and seek theory.
AVERY (off-screen): Sometimes you'll see a huge ball of bait fish
moving in a unified, mass almost.
And sometimes we see sand tiger sharks cloaked in
these large schools of bait fish.
And so occasionally you'll see the sharks kind of unexpectedly part,
the bait ball, and emerge from this almost
invisibility cloak that the bait fish are forming.
NARRATOR: It’s a compelling observation.
If sharks are using bait fish as camouflage to attack,
they may be capable of using shipwrecks to camouflage
in the same way.
Ryan says it’s neither.
RYAN (off-screen): There is really no evidence that sharks actively
use these schools of fish or these shipwrecks to camouflage themselves.
It's simply a situation where both these species love and
want to hang out in the same environment.
NARRATOR: Ryan re-examines the Matt Wirt attack and
notices that the shark doesn’t go for Matt,
it goes for his fish.
RYAN (off-screen): In my opinion, what we see in this example is
not ambush hunting.
It was about detecting a struggling fish.
I don't think there was any deliberate attempt by the shark
to use the shipwreck as part of his hunting strategy.
It was more a fact that these sand tigers,
they love these shipwrecks to relax on and this was also
where the spear fishermen were hunting their fish.
NARRATOR: It appears that the camouflage hide and seek theory
is a bust.
Investigators still cannot explain
the frightening encounters on wrecks.
But researchers soon find that sharks may be using shipwrecks
in another way, that puts divers and swimmers nearby at risk.
A terrifying case in southern Florida
provides a new clue.
JESSICA: Ah!
♪ ♪
NARRATOR: South Florida is world-renowned for its beaches.
Most beachgoers have no idea of the area’s
underwater attractions just offshore.
And their dangers.
JESSICA (off-screen): Growing up in Florida
we would always be out on the water.
Going boating, fishing, going to the sandbar.
NARRATOR: It's the weekend and 22-year-old Jessica Hogge and
her friends, are making the most of it on the Intracoastal,
just nine miles from Pompano Beach.
MAN: Hit it! Woo!
NARRATOR: The wreck capital of Florida.
JESSICA: This was actually the first time I had been tubing in years.
The water looks kind of murky.
I was not very comfortable going into the water.
And I just had that feeling that something wasn't right.
I couldn't explain to anybody and they're like,
"Uh, there's nothing wrong. We were just in here.
You're gonna be fine."
MAN: Don’t worry about it honey.
It’ll be fine.
Go tubing, enjoy it.
JESSICA: Clearly I was not.
It felt like a punch.
Like something just ran into me.
Ah!
MAN 2: Hey guys, there’s something wrong.
WOMAN: Are you okay?
MAN: What’s wrong?
CAPTAIN: Get her in!
MAN 2: Grab the ring!
JESSICA (off-screen): I was in complete shock.
Couldn't fathom that a shark had just bit me.
I was just in a state of mind that I, I just not,
this was not real.
NARRATOR: Jessica suffers severe blood loss.
The muscle in her right leg is shredded,
exposing the bone.
It takes three months for a full recovery.
JESSICA (off-screen): I always knew they were sharks in the water,
but I never expected them to attack me.
NARRATOR: Jessica was bitten less than five miles away
from a shipwreck.
Leading investigators to wonder whether there
may be a connection.
Marine biologist Doctor James Sulikowski
takes a closer look.
JAMES: One of the things about Florida is that,
it's got great natural habitat,
it really does.
But when you start adding manmade habitats,
like the shipwrecks, it adds another layer for these sharks
to find refuge.
NARRATOR: There are over 5,000 shipwrecks in Florida alone.
And millions more worldwide.
Each one a mosaic of sea life.
Snapper and grouper.
Turtles and stingrays.
And a whole host of sharks!
JAMES: Wrecks have offered some incredible habitat for
certain species of sharks.
It aggregates their food.
It keeps them safe from predators.
And it's been widely documented that these
are important areas to sharks.
NARRATOR: James says shipwrecks are so valuable to sharks,
that hungry females may use them when they’re pregnant.
JAMES (off-screen): One of the things a wreck might give a pregnant shark is
ample food source.
They don't have to search for it.
So that way they can put more energy into growing their babies.
Also, it's quite possible it could protect them from predators.
So, they're not looking over their backs all the time,
spending energy doing that.
So those areas can help increase the chance of survival
of her babies.
NARRATOR: When near full term, pregnant sharks typically stay
close to their pupping grounds.
If the love nest theory is correct,
and pregnant sharks use shipwrecks as a maternity ward,
perhaps the bull shark that bit Jessica was drawn to the wreck
because she was pregnant.
JAMES: Now what would be really cool is if we can find
that pregnant females are sort of aggregating in these areas
to help protect their growing young.
NARRATOR: To test this theory, James and
fellow shark researcher Brooke Anderson link up
with veteran shark diver Jamin Martinelli.
Jamin takes them three miles offshore to
the Esso Bonaire III.
A former oil tanker and popular dive spot,
known for its sharks.
Finding pregnant sharks here may help explain why sharks swim to
wrecks and perhaps, why they attack.
JAMIN (off-screen): We picked this spot because it’s a wreck,
and there’s many species here.
Bull sharks, lemon, reef sharks, silkies,
duskies maybe hammerhead.
JAMES: And there could be congregations of these
female sharks here, and they could be pregnant.
NARRATOR: To find out whether the sharks on the shipwreck are pregnant,
Brooke has brought a brand-new piece of tech.
A custom-built underwater ultrasound.
BROOKE: So you guys are going to be able to take this ultrasound
down to the wreck with you and find out if these sharks
that are using the wreck are pregnant in real time.
JAMIN: At 80 feet?
BROOKE: Yeah, let’s get you guys in the water.
JAMES: Let’s do it!
NARRATOR: Today, Brooke spots for sharks at the surface,
while James runs the ultrasound
and Jamin watches his back.
JAMES (off-screen): There's always unknowns,
but to do an underwater ultrasound,
to see if they're pregnant we're going to have to
get down there and get really close.
JAMES: Let’s do this!
JAMIN: Here we go!
JAMES: Do you see any sharks yet?
JAMIN: Nothing.
They’re usually here.
This is strange.
NARRATOR: Suddenly...
JAMIN: Woah! Look out!
JAMES: Oh man. That shark came out of nowhere.
Look at the size of it!
JAMIN: And it’s a female!
JAMES (off-screen): Almost immediately, a big female lemon shark.
JAMIN: Not everyday you see a lemon that big.
JAMES: I wonder if she’s pregnant.
JAMES (off-screen): And the amazing thing is she actually got pretty close.
JAMES: Oh man, she’s circling me.
JAMES (off-screen): These sharks are quick, you have to be fast reacting.
JAMIN: Okay, this is getting a bit sketchy.
NARRATOR: But James sees an opportunity.
JAMES: I just need a couple of seconds of good contact
to see if she’s pregnant.
JAMIN: Okay.
JAMES (off-screen): It’s scary to know that one turn and we could be gone.
JAMES: Woah!
JAMIN: Woah, that was a close one!
JAMES: Yeah, no kidding.
NARRATOR: At a wreck 80 feet underwater,
ultra-sounding an aggressive lemon shark is no small task.
JAMES: Dang it!
I missed it!
NARRATOR: But Doctor James Sulikowski,
pulls it off.
JAMES: Man, that was harder than expected.
NARRATOR: The only question...
JAMIN: What do you think?
Is she pregnant?
JAMES: It’s possible
but there’s no way to tell down here.
Let’s get back topside.
JAMIN: Copy.
NARRATOR: Later that evening,
James reviews the day’s ultrasound footage.
He isn’t 100% sure what he’s seeing indicates a pregnancy.
JAMES: Hey, so Brooke, running through the video right now,
and I think I got something.
I want you to take a look at it,
I want you to let me know if you think she’s pregnant or not.
BROOKE: All right, let’s take a look at this ultrasound.
NARRATOR: Lemon sharks are known to birth up to 17 pups.
If this shark is pregnant,
the team should be able to spot a few embryos.
JAMES: It's going to come into focus.
BROOKE: This is really cool.
JAMES: Amazing.
Right here.
BROOKE: Oh, yeah, yeah, yeah. JAMES: What do you think? Fast!
BROOKE: I think she’s pregnant, for sure.
JAMES: Yeah super-fast. It's super cool isn’t it?
BROOKE: That’s incredible. JAMES: Yeah.
NARRATOR: They think they spot at least three pups
in the ultrasound.
BROOKE: Oh, yeah. JAMES: See that?
BROOKE: Absolutely. JAMES: Yeah.
BROOK: That's amazing.
What does this mean?
JAMES: You know, now it kind of brings in the importance of maybe that,
that wreck and what could she be doing there?
NARRATOR: It appears Sulikowski’s theory that
shipwrecks may attract pregnant sharks could be true.
But the experiment creates more questions than answers.
JAMES: As fate would have it, the shark was pregnant.
So what that does for us right now is open up all these avenues
for new research, not only here in Florida,
on wrecks, but all over the place to see how these
pregnant sharks might be using this habitat.
But there could be other factors why they are here.
NARRATOR: Those other factors may have to do with another
kind of man-made marine habitat.
That investigators fear may bring sharks
dangerously close to people.
A case just down the coast from James’s test,
could offer proof.
ALVARO: So how deep are we diving?
ERIK: We’re going about 60 feet today.
You good with that?
ALVARO: Hell yeah that’s great.
NARRATOR: 50-year-old dentist Alvaro Ordonez and his friends
love nothing more than spearfishing.
WOMAN: Ready? ALVARO: Yep.
♪ ♪
NARRATOR: Alvaro sets off on his own.
And quickly spears a fish.
But he has company.
♪ ♪
WOMAN: Shark! MAN: We’ve got a shark!
(overlapping chatter)
NARRATOR: In an instant,
the water explodes with a cloud of blood.
Alvaro’s blood.
REPORTER (over TV): A day of spearfishing nearly turned tragic.
REPORTER 2 (over TV): Alvaro Ordonez survived
a shark attack all thanks to his friend
Erik who pulled him out of the water after hearing the commotion.
NARRATOR: At the hospital,
doctors confirm Alvaro was bitten by a bull shark.
ALVARO: He came at me, grabbed it by the snout,
it was massive.
ERIK: Lou, this is one of my very good friends.
NARRATOR: It takes five hours of surgery to repair
shredded tendons and a severed artery.
ALVARO: I was bleeding massively.
It was like a hose, like an open hose.
Several sharks came up, like I counted six and they,
they were swimming all over the place.
NARRATOR: When investigators review the terrifying attack,
they quickly discover an unexpected clue.
Alvaro was attacked less than four miles from the Neptune Memorial Reef,
the largest artificial reef ever conceived.
Since 2007, dozens of sharks have been spotted haunting
the Neptune Memorial Reef.
Hammerheads.
Tiger sharks.
And bulls.
Along with thousands of divers who visit it every year.
Leading researchers to wonder,
if artificial reefs might attract big predatory sharks.
And put people like Alvaro, who use the water nearby,
in danger.
Avery says, when it comes to artificial reefs and sharks,
it’s all about the design.
AVERY: When artificial reefs are installed,
they do form habitat for a vast variety of fish.
And that includes not only the small bait fish,
but also the large predators like sharks.
NARRATOR: According to Avery, as soon as a manmade structure,
like metal or stone, is sunk,
it starts to form these marine habitats.
AVERY (off-screen): There are many unanswered questions about
how these structures function ecologically,
that our team is beginning to chip away at.
But our team does have evidence that sharks do tend to hang out
more frequently on the artificial reefs compared to
the natural reefs.
NARRATOR: And that has implications for all underwater structures.
AVERY: When we looked at why that might be,
that’s where we found something really intriguing.
MAN: Topside!
(laughs)
MAN: We have a visual.
(laughter)
MAN: You did it. MAN 2: Good grief.
MAN: Here we go.
AVERY (off-screen): When managers select what type of artificial reef to
put under water, they are weighing how to make these sites
the best for a variety of fish.
And oftentimes the more complex a structure,
the more sharks it can generally support.
NARRATOR: Avery says it’s not just complexity that might
attracts sharks, it’s height.
AVERY (off-screen): One of the things that we've learned about
artificial reefs is that the taller reefs almost act like
skyscrapers and they attract a wide assortment of marine life
and often big predators like sharks.
We don't entirely know why the height of the reef is so critical.
We have a few different theories.
One is that it might relate to food.
NARRATOR: Research suggests that the water around tall structures
is often rich in plankton.
These plankton booms create a predictable feeding ground
for small bait fish.
Fish that dangerous sharks often devour.
AVERY: When you have a tall structure,
you oftentimes have these huge glittering silvery balls of bait fish
that can be prey items for some of these large predators.
So if the shark’s food is there maybe those animals
will be drawn to these high relief structures.
NARRATOR: It seems the design of structures
like artificial reefs, especially vertical ones,
provides a valuable feeding ground for sharks.
So valuable, that Avery says sharks may gravitate towards
not one, but many shipwrecks during their lifespan.
AVERY (off-screen): We think that sharks might be using
these human-made structures as rest stops
on their journey from Point A to Point B.
It's really interesting because if you're a large predator and
you're moving along a particular swath of the ocean,
oftentimes there's going to be a desert of sand.
And these habitats provide little islands or oases that
the predators can stop at to get food or also rest.
NARRATOR: If sharks use shipwrecks and other structures
as pit stops in our oceans,
investigators question if they return to them?
Putting people who dive and fish nearby at risk.
A case in Cape Cod, Massachusetts
may reveal the answer investigators are looking for.
MAN (over radio): It’s another sunny day here on the Cape.
Tourist season is underway.
NARRATOR: Just down the coast from a 140-year-old shipwreck,
50-year-old Chris Myers and his son JJ are on vacation.
JJ: Dad, where are we going?
CHRIS: To the sandbar.
Let’s go.
NARRATOR: They make their way 400 yards from shore,
in search of a shallow patch of sand.
JJ: How deep are we?
CHRIS: I don’t know. Hold on.
NARRATOR: Little do they know,
they’re out of their depth.
♪ ♪
NARRATOR: Chris’s son JJ is a sitting duck.
(panting)
CHRIS: It’s too deep.
I can’t reach the bottom.
Let’s go.
NARRATOR: Suddenly...
CHRIS: Agh! JJ: Dad! Dad!
NARRATOR: A Great White shark traps Chris’s left ankle in its jaws.
JJ: Dad!
NARRATOR: Chris kicks out.
(screams).
NARRATOR: And frees his foot.
(screaming).
CHRIS: Go! Go! Go!
NARRATOR: But the shark may not be done.
JJ: Come on!
Help, we need help.
Dad! Dad, come on!
Dad, come on.
Come on. Help! Help!
NARRATOR: Once back on land,
the extent of his wounds becomes clear.
Chris suffers lacerations,
nerve damage and a severed tendon.
GREG (off-screen): The attack on Chris was a shock to the world.
There hadn't been an attack in Massachusetts waters
in 76 years.
NARRATOR: Doctor Greg Skomal studies sharks in Cape Cod.
He says Chris’s attack was only the beginning.
GREG: Since Chris was bitten,
we have seen more of these kinds of incidents.
Kayaks and sharks.
(yells)
WOMAN: Oh, my God!
GREG: Paddle boards and sharks.
MAN: Coming in and he's right here.
GREG: And on two other occasions, attacks on human beings.
NARRATOR: Since 2012, hundreds of Great Whites are spotted in the Cape,
and at least five people are attacked.
GREG: This was a wake-up call to the local community where
people said, "Okay, there are white sharks here."
And not only that, but they can bite somebody.
And so we have a lot of questions,
the first one being, okay, why are the sharks here?
You know, and that's something I really wanted to
get to the bottom of.
NARRATOR: Investigators race to understand what’s driving
this white shark incursion.
They quickly uncover a theme.
There’s one thing the Cape has no shortage of;
shipwrecks.
GREG: Cape Cod historically has been
an ocean graveyard for shipwrecks.
GREG (off-screen): There's thousands of shipwrecks around Cape Cod and
some of these shipwrecks are actually quite close to shore
in an extremely shallow water and
they become attractants to all kinds of marine life from
the smallest fishes up to large predatory sharks,
including white sharks.
NARRATOR: Investigators already know sharks likely use
shipwrecks as pit stops for food and shelter.
The question now is;
are the same sharks returning to these wrecks, year after year?
Greg says it’s possible.
GREG (off-screen): We know that large pelagic sharks visit
these shipwrecks because of the abundance of prey,
despite the fact that the rest of the year,
they may be thousands of miles away.
NARRATOR: Greg digs into his tracking data.
MAN: Oh!
GREG (off-screen): We've tagged enough white sharks to demonstrate
that the same individuals come back to Cape Cod year
after year after year.
We've even got acoustic receivers on shipwrecks that
demonstrate that a number of white sharks visit
those shipwrecks.
So I think it's entirely possible that if a shipwreck is
a very productive area for a specific white shark or
a number of white sharks,
they're going to come back to that year after year.
NARRATOR: If this is true, the white shark that bit Chris Myers
might have been on a yearly trip to a nearby shipwreck.
CHRIS: Agh! JJ: Dad!
NARRATOR: Researchers need more evidence to know for sure,
if wrecks with abundant prey can be a constant draw for sharks.
A study over 1,000 miles away in the Bahamas
could have the answer.
ILIJAH: That one’s coming in quick!
SMUKALL: All right here we go.
NARRATOR: The Bimini Shark Lab’s Matt Smukall is on a mission to
determine if sharks can remember feeding grounds and
return to them.
SMUKALL (off-screen): There's shipwrecks all along the coast that are
prime habitat for sharks.
What we want to know is can sharks navigate back to
those areas and use them repeatedly over time.
NARRATOR: The implications could be huge.
To test this, Matt targets a familiar mangrove known for
lemon sharks with fellow shark researcher Sophia Emmons and
assistants Ilijah Louis and Alina Hussey.
About 30 days ago, the shark lab baited this mangrove
near a set of radio receivers.
Receivers that ping every time a tagged lemon shark swims past.
The team then returned every day for a month and baited in
the exact same place at the exact same time
with the exact same bait.
SMUKALL: What we now want to know, is,
are the same individuals coming back at the same time each day
to that spot to be fed?
All right, Sophia we’re here,
you’re good to go ahead and drop the anchor.
NARRATOR: Today the team will set the bait one last time.
SMUKALL: Let’s just really quietly approach and
see if there’s any lemons already are waiting for us.
NARRATOR: And see whether the same lemons sharks observed at
the start of the test come back.
SMUKALL: Let’s go ahead and start the baiting.
NARRATOR: It doesn’t take long for sharks to arrive.
SOPHIA: Look at that, they're already here!
They must've already been here before we even got here.
NARRATOR: A group of juvenile lemon sharks rush the bait tube.
ILIJAH: That one's coming in quick; look at it.
SOPHIA (off-screen): When we started baiting here,
we were seeing these sharks come in, but it took them a bit of time,
maybe five or ten minutes.
So now they're really coming in fast.
NARRATOR: Based on the tracking data,
Sophia says these are some of the same individuals
first observed 30 days ago.
SOPHIA: I remember seeing a few of these from day one
when we started baiting here.
NARRATOR: Suggesting lemon sharks can remember a location and swim back to it.
So long as the area has something beneficial,
like a reliable food source.
SMUKALL: Seeing the same individual sharks here,
and obviously these lemon sharks,
have a really high site fidelity.
So they keep using those same areas within their home range,
time and time again.
NARRATOR: But what about larger sharks,
like the Great Whites in Cape Cod?
SMUKALL: It's very plausible that this goes on with other species of sharks
where they can remember a reliable food source,
whether that's at an estuary or a reef or a shipwreck.
NARRATOR: Doctor Greg Skomal is
not surprised by the Shark Lab’s findings.
GREG (off-screen): Any habitat that provides food,
protection sharks are going to go back to it.
And that includes shipwrecks.
A good example are sand tigers off North Carolina coming back
to sites consistently, up to six years later.
That's a remarkable memory, you know,
to be able to navigate in many cases,
thousands of miles away,
that's mind blowing.
NARRATOR: Given this revelation about shark memory,
perhaps shipwrecks are to blame for the yearly influx of
white sharks in Cape Cod.
And can finally explain why the shark that bit Chris Meyers was
drawn to the area.
Greg says, think again.
GREG: Even though white sharks do visit shipwrecks around Cape Cod,
I think there's a driving force there
that completely obliterates the idea that shipwrecks are
bringing white sharks close to shore.
It's the growing presence of seals in the area that is
drawing these sharks close to shore.
NARRATOR: The gray seal is a favorite meal for large Great Whites.
And for the past 50 years,
the Cape’s seal population has skyrocketed.
GREG (off-screen): Having seals come back to the area from virtually
being non-existent draws these sharks close to shore.
So that shark that bit Chris Myers was hunting in the area.
And it's my conviction that that shark was confused and
wanted to get a sense of what he was.
CHRIS: Agh! JJ: Dad!
GREG: And luckily for Chris, it was a minor bite versus
a fatal attack.
CHRIS: Go! Go!
NARRATOR: The idea that shipwrecks cause these predators
to attack seems unlikely.
But something is still driving sharks to ocean graveyards and
causing dangerous encounters.
GREG (off-screen): It’s not the people that draw sharks to shipwrecks.
It's not really the structure itself.
It's the species that live on those shipwrecks that
draw those sharks there.
NARRATOR: Whether it’s an underwater structure close to shore or a ship
lost at sea, sharks can find refuge there.
AVERY (off-screen): Both artificial reefs and shipwrecks
form incredible oases for big predators like sharks.
NARRATOR: Some sharks use wrecks for rest.
Others may stop by for a pre-natal meal.
JAMES: These gestational grounds,
whether they be shipwrecks or some other marine sanctuary,
need to be studied.
NARRATOR: Whatever the reason,
one thing is certain.
If sharks are there,
it’s a sign the environment is thriving.
GREG (off-screen): Its structure generates life,
as long as shipwrecks provide a healthy habitat for
the entire food web, sharks will be there.
Captioned by Cotter Media Group.