Great Shark Chow Down (2019) Movie Script
[narrator] From high-speed attacks
to pack hunts...
Sharks have evolved to feed
in extraordinary ways.
But how do they do it?
When you're that big,
that fast, that powerful,
you can eat anything you want.
[narrator] Now leading
scientists and filmmakers
brave all to unlockthe science behind
five of the world's ultimate
shark feeding events.
[man] Whoa. Amazing.
[narrator] From a 7-ton whale...
[man] We were witnessing
a major feeding event.
[narrator] To the feast
that feeds 700 sharks...
You're about to witness some of
the greatest shark chow downs.
[diver] Ah.
[narrator] It's winter off
South Africa's east coast,
and one of the biggest
chow down events on Earth
is about to take place.
Hundreds of millions of
baitfish are swept north
on cold water currents.
Trapped by land to one side
and warm water on the other,
they form dense, black schools,
some over 15 kilometers long.
Known as the sardine run,
this unique event islike a dinner bell.
Hundreds of sharkshead to the feast.
Blacktips...
spinners...
and copper sharks form
one of the greatest gatherings
of hunting sharks on Earth.
And they're not alone.
Vast super pods of over
one thousand common dolphins
track the growing shoals,
followed by hugeflocks of birds,
and leviathans,
like the 17-meter-longBryde's whale.
Every year, for the last 10 years,
cameraman Morne Hardenberghas set out
to find the sardine shoals.
[Morne Hardenberg]
The sardine run goes through cycles.
Some years are really good.
Some years no sardines
come though the area.
We never know before the time,
so you just have to be there
and hope for the best.
[narrator] In 2010, Morne got lucky.
[Morne] We looked up onto the horizon
and we just saw flocks of birds
raining down into the ocean.
And we knew that there was
potentially a bait ball there,
so we raced over there.
Then when we got there,
you could actually see the fish
boiling on the surface.
Dolphins were working the bait ball hard.
It's mind-blowing how fast things happen.
[narrator] The currentspush the sardines
closer and closer to shore.
The ocean's ultimate chow downhas begun.
[Morne] But when I got into the water,
there was a mass load of sharks
below the bait ball,
but they were just slowly
cruising and circling.
I was just amazed to see how many sharks
and how many dolphins there really were.
It was mind-blowing.
Dolphins were spinning.
I could hear them communicating
with each other,
and they were pushing this
bait ball up to the surface.
[dolphins squeaking]
[narrator] Trapped, the terrified fish
have nowhere else to go.
[Morne] And once they get it
up to the surface,
that's when the birds start
taking advantage of it.
[birds squawking]
Once the birds start hitting the water,
it's like cannon fire going off.
It's literally like being
in the middle of a war zone.
[narrator] Diving from heights
of 30 meters,
the Cape gannets hit the water
at 100 kilometers per hour.
[dolphins squeaking]
With the bait ballat the surface,
finally, the sharksjoin the feast.
[Morne] Took one shark
to go through this ball
and once the one shark went
through and started feeding,
it's almost like he pulled a trigger
and then more just came in.
It was just chaos with sharks everywhere.
The sharks, they swim straight into it,
with their mouths open,
and take as many bites
as they possibly can.
And you can actually see
all the scales of the sardines
coming out of their gills.
When you're in the water
with a bait ball this size,
it makes you feel really small.
[narrator] But some 20 minutes
into this extraordinary event,
Morne was about to feeleven smaller.
A 40-foot Bryde's whale
joins the chow down.
The few remaining fish scatter.
The feast is over.
[groaning]
[Morne] Your heart is pounding.
At the end of the day,
it takes a while before you calm down
from an event like that.
So what really struck me
from this bait ball
was how patient the sharks were
and how they waited for the
dolphins to do all the hard work
before they came in and made their move.
These sharks are smart.
Doesn't matter what
shark species they are,
they're working together to get
the most out of the bait ball
before the bait ball either escapes
or the bait ball is finished.
[narrator] Taking advantage
of the dolphins' hard work
is one thing,
but three years later,
Morne captured rare evidence
the sharks are capable of
far more than just freeloading.
[Morne] We were following birds around,
and we looked out on the horizon,
all the birds were piling into the water.
What was interesting to see
was there were no dolphins
working around the bait ball
on the surface,
just the birds going in.
And when we got into the water...
Literally I've never seen
so many sharks in my life.
There was not one dolphin, just sharks,
probably at least 300 sharks.
[narrator] With no oneto herd the fish,
Morne assumed the sharkswould go hungry.
He was wrong.
[Morne] What they were doing
was they were bringing this
bait ball up to the surface
and trapping it up to
the surface all by themselves,
and that was the very first time
that we actually saw a bait ball
being formed just by sharks
and no dolphins.
[narrator] The sharks start
to herd the ball
toward the surface,
creating a gianttornado of fish.
The terrified shoalmoves as one.
Called the "predatorconfusion effect,"
it makes it difficultfor sharks to hunt.
But the sharks havestrength in numbers.
At least three differentspecies of sharks
seemingly cooperate,
trying to keep the ball stable
on the surface to feed.
But it's the spinnersand blacktips
who appear to domost of the work,
trying to keep the ball trapped
so they can all chow down.
The sharks gorge themselves
until they can't eat any more.
[Morne] What was really
impressive on this bait ball
was the fact that the sharks
did all the work.
They found the shoal of fish,
they got the shoal of fish
into this frenzy,
where the shoal became a bait ball,
and then they pushed this bait ball
all the way up to the surface
of the water to get it trapped.
The sharks were doing
what the dolphins do,
and that makes them smart in many ways.
[Greg Skomal] You know,
we tend to think of sharks
as being solitary hunters,
but here's a really great
example of a group of sharks
working together for their
mutual benefit, you know,
and I think that would have
surprised a lot of people.
The sharks that we typically see
attack these sardine runs
are the requiem sharks.
These are, you know,
closely related species
that include the blacktips,
the duskies, the copper sharks
that are moving in,
likely from great distances,
to take advantage of these resources.
One thing we know about
these requiem sharks
is they have a fairly sizable brain,
bigger than many other shark species,
and we think the complexity of that brain
not only allows them to have
really amazing sensory systems,
but also, perhaps, some kind of
social network that they follow,
so it's entirely possible
that it allows them to work
so cooperatively in these bait balls.
[narrator] Next, discover what
white sharks have in common
with serial killers...
in The Great Shark Chow Down.
[narrator] Dawn, near
the southernmost tip of Africa.
It's mid-winter and Cape fur seals
are weaning their pups.
Over 60,000 adults and
their young crowd together
on this granite rockknown as Seal Island.
Soon, the pupsmust go it alone.
But the waters here
are some of the most dangerous
on the planet.
Over 300 white sharkspatrol the island.
And aerial chow downs
can happen at any time.
But adult sealsare dangerous prey.
Fierce and fast,
they can easily injure a shark.
[Greg] Big seals will fight back.
They're smarter, they're agile,
they can dance around
a white shark in the water
very, very easily.
So what they do is
they target the juveniles,
which tend to be more naive,
they're smaller,
they're easier for them to catch.
[narrator] Now, scientists
are beginning to uncover
the secrets of how
the white sharks hunt here.
The seals gather in
the safety of the shallows.
Just right off of where the seals
are leaving and returning from,
the bottom depth drops off
to over 100 feet.
[narrator] It's here
the white sharks wait.
With a counter-shaded body,
dark at the top,
they're barely visiblefrom the surface.
To reach their fishing grounds,
the young seals make a kamikaze dash
for the open ocean.
White sharks can see 10 times
better than us in low light,
allowing them to see
the silhouetted outline
of the seals.
Reaching speeds
of over30 kilometers an hour,
the white shark launches
three meters into the air.
It's the ultimatesurprise attack
from a perfectly designedambush hunter.
When we look at the white shark,
we can see it's really,
really well adapted.
It's made up mostly of muscle,
called fast-twitch muscle.
That allows the shark to accelerate
very, very, very quickly.
We look at the shape of the white shark.
It's like a missile.
It's capable of not only
protruding those jaws,
but exerting incredible force
on its prey item.
[narrator] But despite
being perfectly adapted
to ambush their prey,
scientists have long wondered
if these attacks need brains
as well as brawn.
[Neil] As a scientist, we only
see the final part of the attack
which is the moment that
the shark meets the seal,
but we don't know anything
actually about the precursor,
the hunting stage.
Whether the sharks were randomly hunting,
just, you know, going for a seal
when the opportunity was there,
or if there was a little more
hunting strategy involved,
something happening below the surface.
[narrator] To answerthat question,
Neil took an unusual step.
Teaming up witha criminologist,
they appliedFBI profiling techniques
normally used to huntserial killers.
Little did we know
that this tool would be applicable
to our research on
white shark attacks on seals.
[narrator] Treating Seal Island
like the site of a crime scene,
the science team plotted
the exact location
of 340 white shark attacks.
At first glance,
the attacks looked random,
but the FBI toolfound a pattern.
[Neil] The white sharks showed
a clear search base,
or anchor point,
and what this meant is that
the sharks were not hunting,
you know, randomly,
that they were stationing themselves
prior to launching an attack
in a spot that was optimal.
[narrator] Like humanserial killers,
the white sharks were hunting
their victims strategically,
and carefully choosingthe best locations
to launch their strikes.
Getting this type of information
in the shark world
where their movements
and their behaviors are otherwise hidden
and invisible to us
under the water's surface,
I mean, this is just amazing.
[narrator] And when
they ran the data again
looking at sharksof different sizes,
another amazing patternstarted to emerge.
[Neil] The largest sharks
had very well defined,
small, focused anchor points,
and they had much higher success rates.
Whereas the smaller sharks,
their hunting was much more
dispersed over a larger area,
and their success rate
was less than 45% overall.
This is clear evidence
of potential learning
in which that learning
actually affords them
higher hunting success rates.
[narrator] Far frommindless killers,
Neil's work revealedadult white sharks
learn from their mistakes,
honing their skillsas they age,
they becomeincreasingly deadly.
[Neil] An adult great white
off of Seal Island
has a success rate on average over 70%.
If you compare that to, like, a lion,
their success rate's only 12%.
[narrator] Next, how a vital ocean event
feeds more than 200 sharks...
[man] Whoa. Amazing.
[narrator] ...in an epic7-ton chow down.
[narrator] From aerial acrobats
to group attacks,
sharks have evolved to hunt
in extraordinary ways.
But these master opportunists
don't just kill,
they also scavenge.
When a whale dies at sea,
it's called a whale fall.
And it can trigger one of
the biggest feeding events
in the ocean.
Hundreds of different creatures
come to the feast.
And sharks arefront and center.
[Greg] Whale falls are incredibly
important feeding events.
Think of it as the sudden appearance
of an oasis in a desert.
[narrator] Impossible to predict,
studying these events is tough.
So scientistsin southern England
took matters intotheir own hands.
Being towed out to sea,
stabilized by buoyancy bags,
is the body
of a nine-meter humpback whale.
Found drowned in fishing lines,
a team of scientists led by
shark expert Richard Peirce
are taking it back out to sea
to study who comesto the 7-ton chow down.
This was the first whale fall event
to be studied and filmed
in British waters;
dramatic, very exciting,
and scientifically very valid
and interesting.
And this is one of nature's
great feeding events.
It's a natural event,
and it attracts predators and
scavengers from miles around.
[narrator] The locationfor the experiment
is 80 kilometers from the British coast,
in an area calledthe Celtic Deep.
Every spring, the warm
Gulf Stream collides
with the coastal waters here,
fueling a feast of plankton,
massive shoals of fish,
and hopefully sharks.
80 kilometers from land,
the team drifts with the whale
at the surface.
Replicating what happens
when a whale dies at sea.
Oil from the whales' blubber
leaves a slick,
the currents carry
for kilometers and kilometers.
Sharks with their
incredible sense of smell
should find it irresistible,
but so far, the onlyvisitors are gulls.
There was trepidation,
a little bit of worry,
would any sharks rock up?
[narrator] But 36 hours
into the experiment,
the birds startto look agitated.
Something is in the water.
[Richard] Shark! Shark!
There. Look to the left.
[woman] Oh, yes.
- [Richard] See it?
- [woman] Yeah, yeah.
[Richard] Suddenly, there was
the blue back of a blue shark.
It was absolutely breathtaking.
Don't break.
[woman] There we go.
[narrator] At one and a half meters,
it's a young adult.
[Richard] Minutes later, we had
one almost double the size,
probably about 8-foot.
[narrator] With the first
sharks in the area,
the dive team deploys.
Blue sharks have beenresponsible
for four recorded fatalities.
[man] Blue shark, blue shark.
[narrator] While attacks are
extremely rare,
the dive team needs to be careful.
One of the North Atlantic'stop predators
is about to chow downon 7 tons of whale.
With every head shake,
more than 50 razor-sharp teeth
saw off mouthfulafter mouthful.
The recycling of some
15 million calories of whale
is underway.
And soon, more and moreblues arrive.
Most are female or juveniles.
Seasonal visitors to the UK,
blue sharks undertake one
of the most epic journeys
in the North Atlantic.
Traveling from as far away
as the east coastof North America,
some ride the Gulf Stream east,
to feed in the UK'srich waters.
[Richard] Many of these sharks
are just from the Atlantic,
and finding this whale fall
will have really been a bonanza.
By the end of day two,
we estimated something like 50 sharks.
It quickly became clear
that this was something really special.
[narrator] Already, the whale chow down
is breathing lifeback into the ocean.
The oily slickcoming from the whale
now extends for tens of kilometers.
The blues are eating
every part of the whale.
Blubber is one of the most
energy-rich foods
on the planet.
Every pound contains
more than 7,000 calories.
With sharks up to 2.7 meters,
the team sees some of
the largest blue sharks
ever filmed in these waters.
But as numberscontinue to grow,
the mood changes underwater.
[Richard] We noticed a behavioral change,
almost as if a bit more
competition was creeping in.
The divers started getting bumped.
[man] Light, light, light,
pull up, pull up, pull up.
[narrator] Sharks bumpprior to an attack.
It's how they assess
what's food and what's not.
[Richard] The only sensible
decision to make
was to pull the divers out.
[man] They're all coming out.
[narrator] Next, as shark numbers soar...
[Richard] Whoa. Amazing.
[narrator] ...more than 200 blue sharks
come to the 7-ton chow down.
[narrator] For two days
scientists have been floating
with the body of a 7-ton whale,
which drowned in fishing lines.
Whale falls are hugely
important ocean feeding events.
The team is studying
who comes to the feast.
Over 50 blue sharks have now
joined the chow down.
[man] Light, light, pull up,
pull up, pull up.
[narrator] After they started
bumping divers,
conditions are now too dangerous
to be in the water,
so a remote operated vehicle,
or ROV, is deployed.
[Richard] First we saw smaller blues
sort of hanging around the outside,
and then as we got in closer
and closer to the whale,
they were bigger sharks
and many, many more of them.
Whoa! Amazing.
Absolutely breathtaking.
[narrator] The team estimates
there are now
well over a hundred sharks
gathered for the chow down.
And looking downinto the depths,
there's blues stacked
on top of each other,
ll the way down to at least 30 meters.
[Richard] We were witnessing
a major feeding event.
It was quite extraordinary.
[narrator] From the air,
there are sharks racing in
on the scent trail.
How far they've come,
nobody will ever know.
By late afternoonthe team estimates
there are at least 150 sharks.
Most are female.
Why there are so few malesis a mystery.
But hardly any seem to make
the big clockwise migration
around the Atlantic.
I went to my bunk that night
and struggled to sleep,
and actually gave up and came up on deck
to make sure I wasn't having a dream.
[narrator] Day four, and
it's bad news for the project.
We'd hoped to study the whale
for at least a week,
and I was devastated when
a storm cut short our research.
[narrator] The whale is sunk
to the seabed.
The floats replaced with ballast
to help it sink.
As the humpback startsits final dive,
the blue sharks stay with it.
They followits slow descent down.
As the whale passes through 30 meters,
the temperatures plummet.
And gradually the lightbegins to fade.
Whale fall occurs at 86 meters.
Only the larger blues seem
to follow the whale down.
But then, after just
a few minutes, they leave.
Temperatures down here
are just 10 degrees.
[Richard] These sharks are
not going to stay very long
at low temperatures,
because they've got to get
their temperature back up again.
[narrator] Now it's time for
the deep sea scavengers.
Sharks, like sixgills, are
known to feed on whale falls.
These living fossils can
grow up to five meters long.
Able to survive in depths
of over 2,500. meters,
and temperaturesas low as five degrees.
A single whale fall is like a bonanza
in these barren depths.
For the blue sharks, it's time to leave.
These ocean wanderers
will ridethe currents south,
in search of their next meal.
Over four days at the surface,
the blue shark chow down
is thought to have fed
at least 200 mouths.
15% of the whalehas been eaten,
and over 2 million calories has
given new life to the sharks.
For scientists, it's been
a rare glimpse into a feast
that happens aroundthe world's oceans.
[Greg] This event with 200 blue sharks
is an incredible chow down.
It tells us how important
these whale falls are
to the species living in
this open ocean environment.
They only encounter food
every now and then,
so they're moving around from
patch of food to patch of food,
and they have to also develop
multiple strategies.
In the case of the blue shark,
they not only take advantage
of whale falls,
there's even evidence
looking at their gills
that they're able to sift small,
tiny, shrimp-like creatures
out of the ocean's environment.
Sharks have adapted over time
through evolution
to all these different environments,
and they've done it so well.
Wherever there's food,
they're gonna find it.
[narrator] Next, what happens
when 700 sharks
join the ultimatenighttime chow down?
[diver] Ah.
[narrator] A remote atoll
in the Pacific is home
to one of the greatest
nighttime chow downson the planet.
A UNESCO biosphere reserve,
Fakarava Atollin French Polynesia
is 55 kilometers long.
At its southern end,
a narrow, 90-meter-wide channel
cuts through its barrier reef.
And it's here one of the
densest gatherings of sharks
on the planet occurs.
Over 700 gray reef sharks
mass in the channel,
riding the strong current.
For the past 8 years, a team of experts
led by cinematographerLaurent Ballesta
have traveledto this remote atoll
to investigate how such
anextraordinary number of sharks
can survive here.
When you count them,
and you reach 700 sharks
in this little channel,
it's quite hard to see how the channel
can feed so many sharks.
There is not enough fish.
[narrator] So what was feeding
this huge army of sharks?
By day, the science team
noticed the sharks rest,
swimming into the currents
to conserve their energy.
But at every full and new moon,
they noticed somethingextraordinary.
Huge shoals of reef fish gather
in the channel to spawn.
It was the sharks'chance to feed.
[Laurent] It's not like
a supermarket, the channel.
It's more like a conveyor belt
in the sushi restaurant,
so the food is passing and
the sharks are just waiting.
[narrator] Driven by
the cycles of the moon,
as one species finished spawning,
the next arrived.
It was an endless cycle
of free food for the sharks.
But the biggest chow downwas yet to come.
Every June, the arrivalof the full moon
triggers the biggest of
the Fakarava spawning events.
18,000 groupers here in this place,
and that was the highest density
known in the world so far.
[narrator] The teamnoticed the sharks
were not hunting the groupers
during the day.
The hunt had to behappening at night.
Using state-of-the-arthigh-speed cameras
and time-splice technology,
what the team discovered next
was extraordinary.
The sharks, which had spent the day
floating in the currentsat mid depth,
were all now at the bottomof the channel,
and the hunt was on.
The first time we went down
and we start to be bumped by the shark,
it was scary.
[bleep]
The feeling was unbelievable.
I never see something with so much action,
so much behavior,
so much energy in the water,
in all my diving life.
[narrator] Slowly, dive after dive,
the team startedto reveal the secrets
of how Fakarava'sgray reef sharks hunt.
Hiding in the coral,
the fish are hard to flush out.
So the gray reef sharkshave to be smart.
Following smallerwhitetip sharks around,
which can swim in and outof small gaps,
they appear to let them
flush out the groupers
before moving in for the kill.
An all-night chow down
on a scale rarely seen before
is soon underway.
The gray reefs mob the fish.
Escape routes blocked,
they make kill after kill.
For the fish, the channel
turned into a kind of trap
that's really not easy for them to escape.
The sharks are everywhere.
I never see something like that before.
I never seen something so intense.
[narrator] Hunting together
gives the sharks
an advantage over the groupers.
If one loses, the other gains.
It's a uniquesort of cooperation.
[Laurent] The shark behavior
is a bit like the wolf,
but the shark never share the prey,
they just fight for it.
[narrator] Across the reef,
theshark pack uses the moonlight
to make attack after attack.
The chow down is so savage
many get injured.
Finally, as the light
of the moon goes out,
the sharks can feast no more.
The ocean's greatest
nighttime chow down is over.
Just before dawn,
the surviving groupers take
their chance to spawn.
And for 30 minutes,
groupsof males chase the females,
releasing clouds of sperm
and eggs into the water.
A new generation of groupers
will face the sharks
of Fakarava next year.
Next, meet the cheetahof the sea...
[man] Shark!
[narrator] ...and the fastest
chow down on Earth.
[narrator] From plankton-eating giants,
to turtle-hunting tigers,
sharks have evolved to become
the ocean'smaster opportunists.
[Greg] I am forever amazed
with sharks, you know.
It's over 500 species that have permeated
all the different waters and
environments of the world.
When I look at all these different kinds
of feeding events,
I'm reminded about how adaptable
this group is.
The reason they've persisted
for over 400 million years,
and that's because they're successful.
From plankton to plants
to bait balls to whales,
sharks have exploited every
imaginable feeding opportunity.
[narrator] And there's one shark
that's capable of going after
the very fastest preyin the ocean.
Off South Africa'sCape Peninsula,
underwater cameramanMorne Hardenberg
is on a new mission to film
thefastest underwater chow down.
Meet the cheetah of the sea,
the shortfin mako.
We know their diet
consists of fast-moving fish
like bonito, mackerel and tuna,
but we don't really know how
they actually hunt these fish.
[narrator] One of the most
energetic sharks,
a mako spends mostof its life alone,
cruising the high seas
with occasional tripsinto coastal waters.
With a top speed of 70 kilometers an hour,
they're the fastestshark on Earth.
[Greg] What's really cool
about the mako is,
like the white shark, it's warm-blooded.
It can elevate its internal
body temperature,
so it's warmer than
the surrounding sea water.
Not many species of fish can do that.
But the fast ones can.
Its tail is built
like the tail of a tuna fish,
which allows it to propel
through the water
with great speed and efficiency.
[narrator] But all thisbio-engineering
comes at a high cost.
Makos burn energy so fast,
they need to eat more
thanalmost any other shark.
Consuming the equivalent of
some 4% of their body weight
every single day.
Because of its capacity
to accelerate to great speed,
the mako shark can almost eat anything.
[narrator] But to find outhow they do it,
Morne needs to deployhis torpedo cam.
He plans to towthese dummy fish
next to thisspecial designed rig,
with a high-speed camerainside.
[Morne] Spent about five months
modifying this camera,
trying to make it as natural as possible,
'cause what we're after is
the actual hunting behavior.
[narrator] 50 kilometers offshore,
the team is ready.
Accelerating to speeds
of 50 kilometers an hour,
they begin trailing the torpedo cam
through the water.
[man] Shark!
[narrator] And 4 hours into the
operation, a shark is spotted.
[Morne] I see it, I see it.
It's coming. It looks interested.
[narrator] Filmed at
600 frames per second,
the mako strikesat 32 kilometers an hour.
[Greg] What I love about this
footage is now we can observe
a mako shark doing what it does best,
that's chasing down a prey item,
latching on to it, and tearing it off.
[narrator] By targeting the tail,
the mako sharkdisables its prey.
In essence,
you're removing the propeller of a boat
and it can't do anything,
and once you've done that,
you've incapacitated it,
makes it a lot easier to eat.
And that's really a wonderful strategy.
Use your own body weight
and your own body drag
in order to separate a chunk
of flesh from your prey item,
so you can feed effectively
and get away from that prey item
should it decide to
turn around and hurt you.
[narrator] It's yet another
different chow down strategy.
A unique approach that
has allowed the mako
to corner the fast food market,
and survive in the vast desert
of the open ocean.
From these barren waters,
to the frozen poles,
wherever there's food,
sharks are never far away,
taking advantage of
any feeding opportunity.
But today sharks worldwideare in trouble.
From makos to blues,
all sharks are in decline.
And the ocean'sgreatest chow downs
may soon bea thing of the past.
[Richard] We're taking
millions of blue sharks
out of the North Atlantic every year.
They're being caught with no limits.
This is a terrible tragedy.
[narrator] And across the world,
from the Pacificto the Indian Ocean,
the story is the same.
Our oceans are in trouble.
Ecosystems are falling.
By netting and over-fishing,
that is the biggest problem
we're facing now.
And we see the impact on the sardine run.
We see the impact of over-fishing
which has caused the sardine stocks
to collapse on the west coast.
Each year we're on the sardine run,
you can't help but feel that
this might be the last one.
[Greg] As top predators,
sharks are critically important
to the marine ecosystem.
Everywhere you look,
sharks are front and center.
So the more we know about
their feeding strategies,
the better equipped we are
to protect the ocean.
[narrator] Without them,
all marine life is in trouble.
to pack hunts...
Sharks have evolved to feed
in extraordinary ways.
But how do they do it?
When you're that big,
that fast, that powerful,
you can eat anything you want.
[narrator] Now leading
scientists and filmmakers
brave all to unlockthe science behind
five of the world's ultimate
shark feeding events.
[man] Whoa. Amazing.
[narrator] From a 7-ton whale...
[man] We were witnessing
a major feeding event.
[narrator] To the feast
that feeds 700 sharks...
You're about to witness some of
the greatest shark chow downs.
[diver] Ah.
[narrator] It's winter off
South Africa's east coast,
and one of the biggest
chow down events on Earth
is about to take place.
Hundreds of millions of
baitfish are swept north
on cold water currents.
Trapped by land to one side
and warm water on the other,
they form dense, black schools,
some over 15 kilometers long.
Known as the sardine run,
this unique event islike a dinner bell.
Hundreds of sharkshead to the feast.
Blacktips...
spinners...
and copper sharks form
one of the greatest gatherings
of hunting sharks on Earth.
And they're not alone.
Vast super pods of over
one thousand common dolphins
track the growing shoals,
followed by hugeflocks of birds,
and leviathans,
like the 17-meter-longBryde's whale.
Every year, for the last 10 years,
cameraman Morne Hardenberghas set out
to find the sardine shoals.
[Morne Hardenberg]
The sardine run goes through cycles.
Some years are really good.
Some years no sardines
come though the area.
We never know before the time,
so you just have to be there
and hope for the best.
[narrator] In 2010, Morne got lucky.
[Morne] We looked up onto the horizon
and we just saw flocks of birds
raining down into the ocean.
And we knew that there was
potentially a bait ball there,
so we raced over there.
Then when we got there,
you could actually see the fish
boiling on the surface.
Dolphins were working the bait ball hard.
It's mind-blowing how fast things happen.
[narrator] The currentspush the sardines
closer and closer to shore.
The ocean's ultimate chow downhas begun.
[Morne] But when I got into the water,
there was a mass load of sharks
below the bait ball,
but they were just slowly
cruising and circling.
I was just amazed to see how many sharks
and how many dolphins there really were.
It was mind-blowing.
Dolphins were spinning.
I could hear them communicating
with each other,
and they were pushing this
bait ball up to the surface.
[dolphins squeaking]
[narrator] Trapped, the terrified fish
have nowhere else to go.
[Morne] And once they get it
up to the surface,
that's when the birds start
taking advantage of it.
[birds squawking]
Once the birds start hitting the water,
it's like cannon fire going off.
It's literally like being
in the middle of a war zone.
[narrator] Diving from heights
of 30 meters,
the Cape gannets hit the water
at 100 kilometers per hour.
[dolphins squeaking]
With the bait ballat the surface,
finally, the sharksjoin the feast.
[Morne] Took one shark
to go through this ball
and once the one shark went
through and started feeding,
it's almost like he pulled a trigger
and then more just came in.
It was just chaos with sharks everywhere.
The sharks, they swim straight into it,
with their mouths open,
and take as many bites
as they possibly can.
And you can actually see
all the scales of the sardines
coming out of their gills.
When you're in the water
with a bait ball this size,
it makes you feel really small.
[narrator] But some 20 minutes
into this extraordinary event,
Morne was about to feeleven smaller.
A 40-foot Bryde's whale
joins the chow down.
The few remaining fish scatter.
The feast is over.
[groaning]
[Morne] Your heart is pounding.
At the end of the day,
it takes a while before you calm down
from an event like that.
So what really struck me
from this bait ball
was how patient the sharks were
and how they waited for the
dolphins to do all the hard work
before they came in and made their move.
These sharks are smart.
Doesn't matter what
shark species they are,
they're working together to get
the most out of the bait ball
before the bait ball either escapes
or the bait ball is finished.
[narrator] Taking advantage
of the dolphins' hard work
is one thing,
but three years later,
Morne captured rare evidence
the sharks are capable of
far more than just freeloading.
[Morne] We were following birds around,
and we looked out on the horizon,
all the birds were piling into the water.
What was interesting to see
was there were no dolphins
working around the bait ball
on the surface,
just the birds going in.
And when we got into the water...
Literally I've never seen
so many sharks in my life.
There was not one dolphin, just sharks,
probably at least 300 sharks.
[narrator] With no oneto herd the fish,
Morne assumed the sharkswould go hungry.
He was wrong.
[Morne] What they were doing
was they were bringing this
bait ball up to the surface
and trapping it up to
the surface all by themselves,
and that was the very first time
that we actually saw a bait ball
being formed just by sharks
and no dolphins.
[narrator] The sharks start
to herd the ball
toward the surface,
creating a gianttornado of fish.
The terrified shoalmoves as one.
Called the "predatorconfusion effect,"
it makes it difficultfor sharks to hunt.
But the sharks havestrength in numbers.
At least three differentspecies of sharks
seemingly cooperate,
trying to keep the ball stable
on the surface to feed.
But it's the spinnersand blacktips
who appear to domost of the work,
trying to keep the ball trapped
so they can all chow down.
The sharks gorge themselves
until they can't eat any more.
[Morne] What was really
impressive on this bait ball
was the fact that the sharks
did all the work.
They found the shoal of fish,
they got the shoal of fish
into this frenzy,
where the shoal became a bait ball,
and then they pushed this bait ball
all the way up to the surface
of the water to get it trapped.
The sharks were doing
what the dolphins do,
and that makes them smart in many ways.
[Greg Skomal] You know,
we tend to think of sharks
as being solitary hunters,
but here's a really great
example of a group of sharks
working together for their
mutual benefit, you know,
and I think that would have
surprised a lot of people.
The sharks that we typically see
attack these sardine runs
are the requiem sharks.
These are, you know,
closely related species
that include the blacktips,
the duskies, the copper sharks
that are moving in,
likely from great distances,
to take advantage of these resources.
One thing we know about
these requiem sharks
is they have a fairly sizable brain,
bigger than many other shark species,
and we think the complexity of that brain
not only allows them to have
really amazing sensory systems,
but also, perhaps, some kind of
social network that they follow,
so it's entirely possible
that it allows them to work
so cooperatively in these bait balls.
[narrator] Next, discover what
white sharks have in common
with serial killers...
in The Great Shark Chow Down.
[narrator] Dawn, near
the southernmost tip of Africa.
It's mid-winter and Cape fur seals
are weaning their pups.
Over 60,000 adults and
their young crowd together
on this granite rockknown as Seal Island.
Soon, the pupsmust go it alone.
But the waters here
are some of the most dangerous
on the planet.
Over 300 white sharkspatrol the island.
And aerial chow downs
can happen at any time.
But adult sealsare dangerous prey.
Fierce and fast,
they can easily injure a shark.
[Greg] Big seals will fight back.
They're smarter, they're agile,
they can dance around
a white shark in the water
very, very easily.
So what they do is
they target the juveniles,
which tend to be more naive,
they're smaller,
they're easier for them to catch.
[narrator] Now, scientists
are beginning to uncover
the secrets of how
the white sharks hunt here.
The seals gather in
the safety of the shallows.
Just right off of where the seals
are leaving and returning from,
the bottom depth drops off
to over 100 feet.
[narrator] It's here
the white sharks wait.
With a counter-shaded body,
dark at the top,
they're barely visiblefrom the surface.
To reach their fishing grounds,
the young seals make a kamikaze dash
for the open ocean.
White sharks can see 10 times
better than us in low light,
allowing them to see
the silhouetted outline
of the seals.
Reaching speeds
of over30 kilometers an hour,
the white shark launches
three meters into the air.
It's the ultimatesurprise attack
from a perfectly designedambush hunter.
When we look at the white shark,
we can see it's really,
really well adapted.
It's made up mostly of muscle,
called fast-twitch muscle.
That allows the shark to accelerate
very, very, very quickly.
We look at the shape of the white shark.
It's like a missile.
It's capable of not only
protruding those jaws,
but exerting incredible force
on its prey item.
[narrator] But despite
being perfectly adapted
to ambush their prey,
scientists have long wondered
if these attacks need brains
as well as brawn.
[Neil] As a scientist, we only
see the final part of the attack
which is the moment that
the shark meets the seal,
but we don't know anything
actually about the precursor,
the hunting stage.
Whether the sharks were randomly hunting,
just, you know, going for a seal
when the opportunity was there,
or if there was a little more
hunting strategy involved,
something happening below the surface.
[narrator] To answerthat question,
Neil took an unusual step.
Teaming up witha criminologist,
they appliedFBI profiling techniques
normally used to huntserial killers.
Little did we know
that this tool would be applicable
to our research on
white shark attacks on seals.
[narrator] Treating Seal Island
like the site of a crime scene,
the science team plotted
the exact location
of 340 white shark attacks.
At first glance,
the attacks looked random,
but the FBI toolfound a pattern.
[Neil] The white sharks showed
a clear search base,
or anchor point,
and what this meant is that
the sharks were not hunting,
you know, randomly,
that they were stationing themselves
prior to launching an attack
in a spot that was optimal.
[narrator] Like humanserial killers,
the white sharks were hunting
their victims strategically,
and carefully choosingthe best locations
to launch their strikes.
Getting this type of information
in the shark world
where their movements
and their behaviors are otherwise hidden
and invisible to us
under the water's surface,
I mean, this is just amazing.
[narrator] And when
they ran the data again
looking at sharksof different sizes,
another amazing patternstarted to emerge.
[Neil] The largest sharks
had very well defined,
small, focused anchor points,
and they had much higher success rates.
Whereas the smaller sharks,
their hunting was much more
dispersed over a larger area,
and their success rate
was less than 45% overall.
This is clear evidence
of potential learning
in which that learning
actually affords them
higher hunting success rates.
[narrator] Far frommindless killers,
Neil's work revealedadult white sharks
learn from their mistakes,
honing their skillsas they age,
they becomeincreasingly deadly.
[Neil] An adult great white
off of Seal Island
has a success rate on average over 70%.
If you compare that to, like, a lion,
their success rate's only 12%.
[narrator] Next, how a vital ocean event
feeds more than 200 sharks...
[man] Whoa. Amazing.
[narrator] ...in an epic7-ton chow down.
[narrator] From aerial acrobats
to group attacks,
sharks have evolved to hunt
in extraordinary ways.
But these master opportunists
don't just kill,
they also scavenge.
When a whale dies at sea,
it's called a whale fall.
And it can trigger one of
the biggest feeding events
in the ocean.
Hundreds of different creatures
come to the feast.
And sharks arefront and center.
[Greg] Whale falls are incredibly
important feeding events.
Think of it as the sudden appearance
of an oasis in a desert.
[narrator] Impossible to predict,
studying these events is tough.
So scientistsin southern England
took matters intotheir own hands.
Being towed out to sea,
stabilized by buoyancy bags,
is the body
of a nine-meter humpback whale.
Found drowned in fishing lines,
a team of scientists led by
shark expert Richard Peirce
are taking it back out to sea
to study who comesto the 7-ton chow down.
This was the first whale fall event
to be studied and filmed
in British waters;
dramatic, very exciting,
and scientifically very valid
and interesting.
And this is one of nature's
great feeding events.
It's a natural event,
and it attracts predators and
scavengers from miles around.
[narrator] The locationfor the experiment
is 80 kilometers from the British coast,
in an area calledthe Celtic Deep.
Every spring, the warm
Gulf Stream collides
with the coastal waters here,
fueling a feast of plankton,
massive shoals of fish,
and hopefully sharks.
80 kilometers from land,
the team drifts with the whale
at the surface.
Replicating what happens
when a whale dies at sea.
Oil from the whales' blubber
leaves a slick,
the currents carry
for kilometers and kilometers.
Sharks with their
incredible sense of smell
should find it irresistible,
but so far, the onlyvisitors are gulls.
There was trepidation,
a little bit of worry,
would any sharks rock up?
[narrator] But 36 hours
into the experiment,
the birds startto look agitated.
Something is in the water.
[Richard] Shark! Shark!
There. Look to the left.
[woman] Oh, yes.
- [Richard] See it?
- [woman] Yeah, yeah.
[Richard] Suddenly, there was
the blue back of a blue shark.
It was absolutely breathtaking.
Don't break.
[woman] There we go.
[narrator] At one and a half meters,
it's a young adult.
[Richard] Minutes later, we had
one almost double the size,
probably about 8-foot.
[narrator] With the first
sharks in the area,
the dive team deploys.
Blue sharks have beenresponsible
for four recorded fatalities.
[man] Blue shark, blue shark.
[narrator] While attacks are
extremely rare,
the dive team needs to be careful.
One of the North Atlantic'stop predators
is about to chow downon 7 tons of whale.
With every head shake,
more than 50 razor-sharp teeth
saw off mouthfulafter mouthful.
The recycling of some
15 million calories of whale
is underway.
And soon, more and moreblues arrive.
Most are female or juveniles.
Seasonal visitors to the UK,
blue sharks undertake one
of the most epic journeys
in the North Atlantic.
Traveling from as far away
as the east coastof North America,
some ride the Gulf Stream east,
to feed in the UK'srich waters.
[Richard] Many of these sharks
are just from the Atlantic,
and finding this whale fall
will have really been a bonanza.
By the end of day two,
we estimated something like 50 sharks.
It quickly became clear
that this was something really special.
[narrator] Already, the whale chow down
is breathing lifeback into the ocean.
The oily slickcoming from the whale
now extends for tens of kilometers.
The blues are eating
every part of the whale.
Blubber is one of the most
energy-rich foods
on the planet.
Every pound contains
more than 7,000 calories.
With sharks up to 2.7 meters,
the team sees some of
the largest blue sharks
ever filmed in these waters.
But as numberscontinue to grow,
the mood changes underwater.
[Richard] We noticed a behavioral change,
almost as if a bit more
competition was creeping in.
The divers started getting bumped.
[man] Light, light, light,
pull up, pull up, pull up.
[narrator] Sharks bumpprior to an attack.
It's how they assess
what's food and what's not.
[Richard] The only sensible
decision to make
was to pull the divers out.
[man] They're all coming out.
[narrator] Next, as shark numbers soar...
[Richard] Whoa. Amazing.
[narrator] ...more than 200 blue sharks
come to the 7-ton chow down.
[narrator] For two days
scientists have been floating
with the body of a 7-ton whale,
which drowned in fishing lines.
Whale falls are hugely
important ocean feeding events.
The team is studying
who comes to the feast.
Over 50 blue sharks have now
joined the chow down.
[man] Light, light, pull up,
pull up, pull up.
[narrator] After they started
bumping divers,
conditions are now too dangerous
to be in the water,
so a remote operated vehicle,
or ROV, is deployed.
[Richard] First we saw smaller blues
sort of hanging around the outside,
and then as we got in closer
and closer to the whale,
they were bigger sharks
and many, many more of them.
Whoa! Amazing.
Absolutely breathtaking.
[narrator] The team estimates
there are now
well over a hundred sharks
gathered for the chow down.
And looking downinto the depths,
there's blues stacked
on top of each other,
ll the way down to at least 30 meters.
[Richard] We were witnessing
a major feeding event.
It was quite extraordinary.
[narrator] From the air,
there are sharks racing in
on the scent trail.
How far they've come,
nobody will ever know.
By late afternoonthe team estimates
there are at least 150 sharks.
Most are female.
Why there are so few malesis a mystery.
But hardly any seem to make
the big clockwise migration
around the Atlantic.
I went to my bunk that night
and struggled to sleep,
and actually gave up and came up on deck
to make sure I wasn't having a dream.
[narrator] Day four, and
it's bad news for the project.
We'd hoped to study the whale
for at least a week,
and I was devastated when
a storm cut short our research.
[narrator] The whale is sunk
to the seabed.
The floats replaced with ballast
to help it sink.
As the humpback startsits final dive,
the blue sharks stay with it.
They followits slow descent down.
As the whale passes through 30 meters,
the temperatures plummet.
And gradually the lightbegins to fade.
Whale fall occurs at 86 meters.
Only the larger blues seem
to follow the whale down.
But then, after just
a few minutes, they leave.
Temperatures down here
are just 10 degrees.
[Richard] These sharks are
not going to stay very long
at low temperatures,
because they've got to get
their temperature back up again.
[narrator] Now it's time for
the deep sea scavengers.
Sharks, like sixgills, are
known to feed on whale falls.
These living fossils can
grow up to five meters long.
Able to survive in depths
of over 2,500. meters,
and temperaturesas low as five degrees.
A single whale fall is like a bonanza
in these barren depths.
For the blue sharks, it's time to leave.
These ocean wanderers
will ridethe currents south,
in search of their next meal.
Over four days at the surface,
the blue shark chow down
is thought to have fed
at least 200 mouths.
15% of the whalehas been eaten,
and over 2 million calories has
given new life to the sharks.
For scientists, it's been
a rare glimpse into a feast
that happens aroundthe world's oceans.
[Greg] This event with 200 blue sharks
is an incredible chow down.
It tells us how important
these whale falls are
to the species living in
this open ocean environment.
They only encounter food
every now and then,
so they're moving around from
patch of food to patch of food,
and they have to also develop
multiple strategies.
In the case of the blue shark,
they not only take advantage
of whale falls,
there's even evidence
looking at their gills
that they're able to sift small,
tiny, shrimp-like creatures
out of the ocean's environment.
Sharks have adapted over time
through evolution
to all these different environments,
and they've done it so well.
Wherever there's food,
they're gonna find it.
[narrator] Next, what happens
when 700 sharks
join the ultimatenighttime chow down?
[diver] Ah.
[narrator] A remote atoll
in the Pacific is home
to one of the greatest
nighttime chow downson the planet.
A UNESCO biosphere reserve,
Fakarava Atollin French Polynesia
is 55 kilometers long.
At its southern end,
a narrow, 90-meter-wide channel
cuts through its barrier reef.
And it's here one of the
densest gatherings of sharks
on the planet occurs.
Over 700 gray reef sharks
mass in the channel,
riding the strong current.
For the past 8 years, a team of experts
led by cinematographerLaurent Ballesta
have traveledto this remote atoll
to investigate how such
anextraordinary number of sharks
can survive here.
When you count them,
and you reach 700 sharks
in this little channel,
it's quite hard to see how the channel
can feed so many sharks.
There is not enough fish.
[narrator] So what was feeding
this huge army of sharks?
By day, the science team
noticed the sharks rest,
swimming into the currents
to conserve their energy.
But at every full and new moon,
they noticed somethingextraordinary.
Huge shoals of reef fish gather
in the channel to spawn.
It was the sharks'chance to feed.
[Laurent] It's not like
a supermarket, the channel.
It's more like a conveyor belt
in the sushi restaurant,
so the food is passing and
the sharks are just waiting.
[narrator] Driven by
the cycles of the moon,
as one species finished spawning,
the next arrived.
It was an endless cycle
of free food for the sharks.
But the biggest chow downwas yet to come.
Every June, the arrivalof the full moon
triggers the biggest of
the Fakarava spawning events.
18,000 groupers here in this place,
and that was the highest density
known in the world so far.
[narrator] The teamnoticed the sharks
were not hunting the groupers
during the day.
The hunt had to behappening at night.
Using state-of-the-arthigh-speed cameras
and time-splice technology,
what the team discovered next
was extraordinary.
The sharks, which had spent the day
floating in the currentsat mid depth,
were all now at the bottomof the channel,
and the hunt was on.
The first time we went down
and we start to be bumped by the shark,
it was scary.
[bleep]
The feeling was unbelievable.
I never see something with so much action,
so much behavior,
so much energy in the water,
in all my diving life.
[narrator] Slowly, dive after dive,
the team startedto reveal the secrets
of how Fakarava'sgray reef sharks hunt.
Hiding in the coral,
the fish are hard to flush out.
So the gray reef sharkshave to be smart.
Following smallerwhitetip sharks around,
which can swim in and outof small gaps,
they appear to let them
flush out the groupers
before moving in for the kill.
An all-night chow down
on a scale rarely seen before
is soon underway.
The gray reefs mob the fish.
Escape routes blocked,
they make kill after kill.
For the fish, the channel
turned into a kind of trap
that's really not easy for them to escape.
The sharks are everywhere.
I never see something like that before.
I never seen something so intense.
[narrator] Hunting together
gives the sharks
an advantage over the groupers.
If one loses, the other gains.
It's a uniquesort of cooperation.
[Laurent] The shark behavior
is a bit like the wolf,
but the shark never share the prey,
they just fight for it.
[narrator] Across the reef,
theshark pack uses the moonlight
to make attack after attack.
The chow down is so savage
many get injured.
Finally, as the light
of the moon goes out,
the sharks can feast no more.
The ocean's greatest
nighttime chow down is over.
Just before dawn,
the surviving groupers take
their chance to spawn.
And for 30 minutes,
groupsof males chase the females,
releasing clouds of sperm
and eggs into the water.
A new generation of groupers
will face the sharks
of Fakarava next year.
Next, meet the cheetahof the sea...
[man] Shark!
[narrator] ...and the fastest
chow down on Earth.
[narrator] From plankton-eating giants,
to turtle-hunting tigers,
sharks have evolved to become
the ocean'smaster opportunists.
[Greg] I am forever amazed
with sharks, you know.
It's over 500 species that have permeated
all the different waters and
environments of the world.
When I look at all these different kinds
of feeding events,
I'm reminded about how adaptable
this group is.
The reason they've persisted
for over 400 million years,
and that's because they're successful.
From plankton to plants
to bait balls to whales,
sharks have exploited every
imaginable feeding opportunity.
[narrator] And there's one shark
that's capable of going after
the very fastest preyin the ocean.
Off South Africa'sCape Peninsula,
underwater cameramanMorne Hardenberg
is on a new mission to film
thefastest underwater chow down.
Meet the cheetah of the sea,
the shortfin mako.
We know their diet
consists of fast-moving fish
like bonito, mackerel and tuna,
but we don't really know how
they actually hunt these fish.
[narrator] One of the most
energetic sharks,
a mako spends mostof its life alone,
cruising the high seas
with occasional tripsinto coastal waters.
With a top speed of 70 kilometers an hour,
they're the fastestshark on Earth.
[Greg] What's really cool
about the mako is,
like the white shark, it's warm-blooded.
It can elevate its internal
body temperature,
so it's warmer than
the surrounding sea water.
Not many species of fish can do that.
But the fast ones can.
Its tail is built
like the tail of a tuna fish,
which allows it to propel
through the water
with great speed and efficiency.
[narrator] But all thisbio-engineering
comes at a high cost.
Makos burn energy so fast,
they need to eat more
thanalmost any other shark.
Consuming the equivalent of
some 4% of their body weight
every single day.
Because of its capacity
to accelerate to great speed,
the mako shark can almost eat anything.
[narrator] But to find outhow they do it,
Morne needs to deployhis torpedo cam.
He plans to towthese dummy fish
next to thisspecial designed rig,
with a high-speed camerainside.
[Morne] Spent about five months
modifying this camera,
trying to make it as natural as possible,
'cause what we're after is
the actual hunting behavior.
[narrator] 50 kilometers offshore,
the team is ready.
Accelerating to speeds
of 50 kilometers an hour,
they begin trailing the torpedo cam
through the water.
[man] Shark!
[narrator] And 4 hours into the
operation, a shark is spotted.
[Morne] I see it, I see it.
It's coming. It looks interested.
[narrator] Filmed at
600 frames per second,
the mako strikesat 32 kilometers an hour.
[Greg] What I love about this
footage is now we can observe
a mako shark doing what it does best,
that's chasing down a prey item,
latching on to it, and tearing it off.
[narrator] By targeting the tail,
the mako sharkdisables its prey.
In essence,
you're removing the propeller of a boat
and it can't do anything,
and once you've done that,
you've incapacitated it,
makes it a lot easier to eat.
And that's really a wonderful strategy.
Use your own body weight
and your own body drag
in order to separate a chunk
of flesh from your prey item,
so you can feed effectively
and get away from that prey item
should it decide to
turn around and hurt you.
[narrator] It's yet another
different chow down strategy.
A unique approach that
has allowed the mako
to corner the fast food market,
and survive in the vast desert
of the open ocean.
From these barren waters,
to the frozen poles,
wherever there's food,
sharks are never far away,
taking advantage of
any feeding opportunity.
But today sharks worldwideare in trouble.
From makos to blues,
all sharks are in decline.
And the ocean'sgreatest chow downs
may soon bea thing of the past.
[Richard] We're taking
millions of blue sharks
out of the North Atlantic every year.
They're being caught with no limits.
This is a terrible tragedy.
[narrator] And across the world,
from the Pacificto the Indian Ocean,
the story is the same.
Our oceans are in trouble.
Ecosystems are falling.
By netting and over-fishing,
that is the biggest problem
we're facing now.
And we see the impact on the sardine run.
We see the impact of over-fishing
which has caused the sardine stocks
to collapse on the west coast.
Each year we're on the sardine run,
you can't help but feel that
this might be the last one.
[Greg] As top predators,
sharks are critically important
to the marine ecosystem.
Everywhere you look,
sharks are front and center.
So the more we know about
their feeding strategies,
the better equipped we are
to protect the ocean.
[narrator] Without them,
all marine life is in trouble.