Secrets of the Bull Shark (2020) Movie Script
Of the most dangerous predators
in the ocean...
only one is bold enough
to invade.
Where you live.
SECRETS OF THE BULLSHARK
The bull shark.
The villain of the tropics...
has a reputation
for being aggressive.
My God.
Jesus.
- Oh, my God.
Like humans, bull sharks
love warm seas.
The coast of Brazil.
Florida, California.
It doesn't stop there.
Unlike other sharks,
they thrive in fresh water.
Rivers, lakes, harbors, canals.
Bull sharks swim
for miles up the Amazon.
They've invaded New Orleans
...
all the way to Lake Pontchartrain.
And even 1,700 miles
up the Mississippi to St. Louis.
And Florida,
with its network of canals...
is full of bull sharks.
Watch out.
That's 400 pounds,
look at that shark.
They swim around in your backyard.
They live and hunt
among people.
A bull shark will even eat
other sharks.
Shark.
- What a big shark.
Jesus.
- My God.
Sorry for swearing.
Did you film that?
They are mysterious and can be
deadly to humans.
This is what we know.
Like real bulls,
they are muscular and broad.
The largest is 11 feet long.
700 pounds of muscle.
And bold enough to steal.
These spearfishermen are used
to competition.
Amberjack. Prized game fish
and a substantial meal.
Bull sharks keep you at bay.
They attack as soon as they can...
...with unpredictable speed.
The great white,
tiger shark, and bull shark
are the three deadliest sharks
on Earth.
The great white
is a cold-water predator.
It can be 7 times heavier and 2 times
as long as a bull shark.
It prefers to eat seals.
The great white hunts
in an iconic way.
It seeks out the weak animals.
And saves its energy...
...for the perfect moment.
Its jaws can bite a seal
in half.
The bull shark's bite
is even stronger.
Bull sharks eat everything.
Dolpins, turtles...
...and even other sharks.
With a bite force of 1000 psi...
...it can break your leg.
The next rival,
the tiger shark.
The garbage cans of the sea.
They eat virtually anything.
Their rows of teeth are like
iron saws.
Larger than bull sharks,
tiger sharks are travelers.
A floating whale carcass
in a tropical sea...
...attracts them in droves.
Bull sharks also swim
in these warm oceans.
They have an extra advantage.
They hunt where tiger sharks
and great whites cannot.
Bull sharks don't need
to eat every day.
As opportunists, they seek
for easy meals.
That they can live on for days.
The east coast of South Africa...
...is one of the coasts
with the most sharks in the world.
A sardine buffet...
...attracts a mass of top predators.
Gannets attack
from the air.
Common dolphins
come to feed.
Just like humpback whales.
And sharks.
Copper sharks. Dusk sharks.
Blacktip sharks.
The bull sharks are conspicuous
by their absence.
There's a reason for that.
Bull sharks can
regulate their salinity.
They can thrive
in estuaries and fresh water.
They can move between
salt and fresh water.
They can hunt far
inland.
Where people live.
And recreate.
Nobody sees them coming.
There she is.
Massive sharks,
miles from the sea.
Bull sharks
invade rivers.
There she goes.
The only deadly shark
that can live in fresh water.
They are so close to us.
Yet we know so little about them.
Dr. Ryan Daly studies
bull sharks in South Africa.
He wants to know why bull sharks
are such good survivors.
Ryan specializes
in shark migration.
Where they feed and breed,
and how that affects their conservation.
For his work, Ryan catches
bull sharks...
...and tags them.
We tag bull sharks
to find out...
...where they go
and where they stay.
So we know their refuges
and the risks...
...during migration.
He gets close to predators...
...that other people
should avoid.
After eight years of tracking...
...he knows bull sharks
travel almost 1,600 km a year.
He suspects they go
much further.
Ryan is doing research
in southern Mozambique.
Nearly 5 km off the coast of Ponta Do
Ouro is a shark hotspot.
A healthy reef full of food...
...is a beacon for predators.
And perfect for researching sharks.
Ryan wants to identify some unique animals.
This way he knows
which sharks live here.
There are so many sharks there.
Five blacktip sharks, some
tiger sharks, and many hammerheads.
It's teeming here.
Ryan is looking for bull sharks.
Big ones.
He records how they hunt
and compete with each other.
Ryan takes his research a step further.
It's almost impossible
to see the world through their eyes.
But with recent techniques...
...we can attach cameras
to sharks to film it.
First, he has to
catch his research assistant.
Bull sharks are difficult to catch,
they sense it.
Bite.
To attach the camera,
the shark must be exhausted.
In a trance-like state,
he collects data.
She has to be on her back.
Looks good.
Ryan takes a photo
before she disappears again.
The camera on the fin will work
once everything is back to normal...
...in 12 hours.
For the first time, the behavior
of a bull shark...
...is recorded in the Indian Ocean.
No human interference.
Just seeing what the bull shark sees.
Viewing prey.
Other sharks.
Blacktip sharks.
Huge tiger sharks.
And, also for the first time...
...a bull shark
filming other bull sharks.
All predatory fish...
instinctively go
for an abundance of food.
Five thousand giant trevallies.
Experienced predators
and a formidable enemy.
They are over 80 kilos each...
and not afraid of sharks.
Trevallies use sharks
to get rid of parasites.
They are also fast.
Not an easy catch.
Every year, around the same time...
just before a full moon...
trevallies come to
Mozambique for their reproduction.
For Ryan, this ritual
is a golden opportunity.
So many big fish.
All together, unbelievable.
It never gets boring.
Thousands of trevallies should be
an unlimited buffet.
Ryan doesn't see any predatory behavior
on the camera yet.
He needs more footage.
That can be done more easily.
We have a new camera...
with a unique perspective
of what the shark sees.
We don't need to catch the shark.
We feed the shark bait. It drags
the camera for about 6 hours.
A blacktip shark
grips the camera first.
Not what Ryan expected.
But an opportunity
to see something new.
The footage shows how the sharks
swim next to each other...
and sometimes even ram each other.
Sharks are very competitive.
But also strategic.
Here come the bull sharks.
Blacktip sharks and bull sharks
surround the trevallies.
The bull sharks are much bigger.
Higher in the food chain.
Like the police on patrol.
Blacktip sharks stay close.
They are waiting for something.
Bull sharks, tiger sharks,
hammerheads and blacktip sharks...
are near a difficult predator.
A school
of 5,000 giant trevallies.
The bull shark's favorite.
After almost 10 years of research...
Dr. Ryan Daly knows
that at least 20 bull sharks...
permanently live
in the waters around Mozambique.
In the summer,
when the trevallies spawn...
many sharks come here
to feast.
There are more scalloped
hammerheads than bull sharks.
They come for the smaller bonito,
not for the trevallies.
Blacktip sharks do.
Bull sharks can open their mouths wide enough for large prey.
Even smaller sharks.
All those sharks, amazing.
Everyone avoids
the bull sharks.
The bull sharks are at the edge
of the school.
And looking for an easy target.
They only need one trevally
a week.
Nowhere are there so many bull sharks
together as here.
Predator versus predator.
A fish that isolates itself
is immediately eaten.
It's a strategy of attack.
'Survival of the Fittest',
the ocean version.
Fit trevallies
reproduce.
The old and sick
are eaten.
Ruthless.
Wow, a bull shark tearing a fish
apart with so much force.
After spawning, the trevallies
spread out.
The sharks too.
The question is, where do they go?
Ryan once tagged a bull shark...
...that traveled 1,600 km to
northern Mozambique, and back.
Another entered
the waters of South Africa.
Even the strongest travelers
face risks.
During migration, bull sharks face many dangers.
Fishing lines, shark nets...
to thin out the sharks, and shark fishers.
More sharks are caught
because of their fins.
Humans are the bull shark's greatest enemy.
But not the only one.
When the hunters enter fresh water...
...there are problems too.
These tourists are getting
the experience of a lifetime.
Hippopotamus versus bull shark.
The most powerful bite
of any mammal.
Against the most powerful bite
of any shark.
About 240 km south
of Ryan's research...
...at the St. Lucia estuary.
One of Africa's largest
tidal wetlands.
A watery mix
of fresh and salt.
Shallow, warm.
Perfect for bull sharks.
And a unique encounter
during a safari.
This shark was trying to catch a fish
and encountered hippos.
Africa's deadliest large land animal...
...and a clue
to a mystery.
We know bull sharks also
look for food in rivers.
There are plenty of rivers
on South Africa's east coast...
...where a bull shark
can swim.
Hidden on the Wild Coast...
...a pristine wilderness.
Untouched, from sea to source.
Such a forested sanctuary...
...is an unlikely place
for marine life.
And for a shark researcher.
Ryan knows there's a guest
from the ocean...
...that can bring him closer
to the bull shark.
You often see
barracuda in rivers.
They can use them
as a nursery.
Or kill sea parasites
in fresh water.
But 200 together, that's strange.
Horse mackerel are found here.
And they form a unique school here.
It's a mystery why
the horse mackerel are here.
Not only does an ocean animal
adapt to fresh water.
Horse mackerel must
overcome the tides...
and swim against rapids.
Large predators
cannot follow the prey.
Smaller ones can.
They are here.
Baby bull sharks.
This is fascinating. You're in the
forests, past rapids.
Actually upstream
of the river.
How do young bull sharks
get so far inland?
After a gestation period of 10 months...
females give birth to one to three young
near the river mouth.
Her work is done.
The baby bull sharks
swim upstream...
away from ocean predators.
Now they have to arrive.
They are mysterious.
Bull sharks are rarely seen.
This is another first.
I've been studying
bull sharks for over 10 years.
I've never seen young
in a forest river...
miles from the ocean
in such an environment.
The perfect habitat
to grow big and strong.
Ryan has found a new nursery.
When the baby bull sharks are big
enough, they go to sea.
Where will they enter next?
The bull shark. One of
the three deadliest sharks.
The great white and tiger shark
are more notorious.
Only the bull shark enters
human territory.
Watch out.
Stealing fish...
and growing up in fresh water,
miles upstream.
Opportunistic,
unpredictable, misunderstood.
Dr. Ryan Daly is with the bull sharks.
He wants to know where they go to eat
and breed.
This way he can protect them.
Bull sharks are seen as
murder machines.
They are apex predators
in our marine ecosystems.
They keep the ecosystems
in balance.
Bull sharks go to Mozambique in the summer
to feed.
Even for sharks,
travel is risky.
Dangers are everywhere.
How do these sharks move
so successfully?
What is their habitat?
To find out...
Ryan goes to the southwestern
point of their habitat in Africa.
The sleepy town of Infanta...
...on the busy Breede River.
At least 30 bull sharks live here
in the summer.
People go there on vacation.
Like Long Island in New York
or the Outer Banks in North Carolina.
All these people and all these sharks
in the same place, madness.
It's incredible that everything is so peaceful.
Hopefully, it stays that way.
Sharks and people
going their own way.
Ryan wants to catch a shark...
...and attach a long-term transmitter.
This will stay on for 6 months
to a year.
On a specific date, it will detach
and transmit data.
Hopefully, we'll know
where they're going then.
Time to catch another shark.
Ryan is working with Dr. John
Filmater, a marine scientist.
It's a tricky job.
This is shark bait.
Now we wait.
A big shark grabs the bait.
Good, some extra pressure.
Perfect, he's a bit angry.
He's furious.
He has a lot of energy left.
He needs to exhaust him first.
A formidable predator
with a short fuse.
He can explode at any moment.
My God.
Until the shark is stuck next to the boat,
anything can happen.
Whoa. There, yeah.
He's getting angry.
- That face.
Watch out.
Male.
He's shaking his head violently.
- Tail up.
It's a monster.
Well done, very good.
We always check if water is flowing
over the shark's gills.
Time to flip him over.
The nearly 3-meter shark
immediately calms down.
It's a big shark.
Has he been weighed?
297 cm.
- Okay.
Jesus.
A small incision
for an internal acoustic tag.
Is that okay?
- Tag this too.
On its back, the shark
is in a trance.
If he turns over too quickly,
there will be problems.
Watch out.
A 2.9-meter bull shark...
in a busy river.
Dr. Ryan Daly wants
to find out the migration patterns.
And see where he's going.
He's close, that's good.
A satellite tag on the dorsal fin
monitors his movements for a year.
It turns on automatically
at 5 meters depth.
He is
released from the water.
Here we go. Turn over.
Not yet, say when.
Ryan helps the shark back.
Watch out.
For 7 days...
tags the team four
large male bull sharks.
By tagging bull sharks,
we discovered...
that they swim at least 32 km
up the river.
Up and down, almost every day.
Bull sharks,
swimming in a river...
surrounded by farms
and holiday homes.
When it gets colder in winter,
the sharks go to the ocean.
We thought they were going to places
with more bull sharks.
To the coast.
The opposite happened.
Once out of the river...
they went to northern
Mozambique, 3200 km away.
Ryan made
a great discovery.
The sharks don't go alone,
but leave the river together.
Like bulls stampeding.
They swim 3200 km
in three months...
all the way to Northern Mozambique.
That's much further than Ryan thought.
The four return in time for
the kingfish on the south coast.
The previous record for bull sharks
was 3200 km.
The four tagged sharks traveled
4800 km for the kingfish.
A new record.
Ryan doesn't know if
his research subjects are still alive.
And if they will return
to the Breede River.
They can only find out...
if Ryan and John go back to
the place where they tagged the sharks.
They hope for a signal
from the transmitters.
We are at the spot.
Let's see if there's a shark.
With a hydrophone,
the acoustic tags can be heard.
If a shark is within 400 meters,
we'll know.
Okay.
Come on, shark.
The tags emit a signal every 40 seconds.
Is that something?
No, false alarm.
I hear something.
One of the sharks.
- 5-0. Awesome.
One of the male bull sharks.
He was 286 cm,
just under 3 meters.
It's one of our big males.
That shark has
traveled at least 2900 km...
north.
Turned around, and came back
to this spot.
A journey of almost 6500 km.
Within a year, he returns
to the same spot.
This is bizarre.
The four tagged males
are in the river.
Two of them arrived
within 30 hours of each other.
They traveled a combined
6500 km.
The longest bull shark migration
ever recorded.
Double the previous record.
Bull sharks migrate
from sea to river...
and back to sea, every day.
In coordinated migration patterns.
Are bull sharks deadly
to humans?
An apex predator...
that is threatened wherever
it goes?
Running a gauntlet through
competition and predators...
to feed
and reproduce.
This year, and every year,
all over the world.
Translation: Elly van der Meijden
in the ocean...
only one is bold enough
to invade.
Where you live.
SECRETS OF THE BULLSHARK
The bull shark.
The villain of the tropics...
has a reputation
for being aggressive.
My God.
Jesus.
- Oh, my God.
Like humans, bull sharks
love warm seas.
The coast of Brazil.
Florida, California.
It doesn't stop there.
Unlike other sharks,
they thrive in fresh water.
Rivers, lakes, harbors, canals.
Bull sharks swim
for miles up the Amazon.
They've invaded New Orleans
...
all the way to Lake Pontchartrain.
And even 1,700 miles
up the Mississippi to St. Louis.
And Florida,
with its network of canals...
is full of bull sharks.
Watch out.
That's 400 pounds,
look at that shark.
They swim around in your backyard.
They live and hunt
among people.
A bull shark will even eat
other sharks.
Shark.
- What a big shark.
Jesus.
- My God.
Sorry for swearing.
Did you film that?
They are mysterious and can be
deadly to humans.
This is what we know.
Like real bulls,
they are muscular and broad.
The largest is 11 feet long.
700 pounds of muscle.
And bold enough to steal.
These spearfishermen are used
to competition.
Amberjack. Prized game fish
and a substantial meal.
Bull sharks keep you at bay.
They attack as soon as they can...
...with unpredictable speed.
The great white,
tiger shark, and bull shark
are the three deadliest sharks
on Earth.
The great white
is a cold-water predator.
It can be 7 times heavier and 2 times
as long as a bull shark.
It prefers to eat seals.
The great white hunts
in an iconic way.
It seeks out the weak animals.
And saves its energy...
...for the perfect moment.
Its jaws can bite a seal
in half.
The bull shark's bite
is even stronger.
Bull sharks eat everything.
Dolpins, turtles...
...and even other sharks.
With a bite force of 1000 psi...
...it can break your leg.
The next rival,
the tiger shark.
The garbage cans of the sea.
They eat virtually anything.
Their rows of teeth are like
iron saws.
Larger than bull sharks,
tiger sharks are travelers.
A floating whale carcass
in a tropical sea...
...attracts them in droves.
Bull sharks also swim
in these warm oceans.
They have an extra advantage.
They hunt where tiger sharks
and great whites cannot.
Bull sharks don't need
to eat every day.
As opportunists, they seek
for easy meals.
That they can live on for days.
The east coast of South Africa...
...is one of the coasts
with the most sharks in the world.
A sardine buffet...
...attracts a mass of top predators.
Gannets attack
from the air.
Common dolphins
come to feed.
Just like humpback whales.
And sharks.
Copper sharks. Dusk sharks.
Blacktip sharks.
The bull sharks are conspicuous
by their absence.
There's a reason for that.
Bull sharks can
regulate their salinity.
They can thrive
in estuaries and fresh water.
They can move between
salt and fresh water.
They can hunt far
inland.
Where people live.
And recreate.
Nobody sees them coming.
There she is.
Massive sharks,
miles from the sea.
Bull sharks
invade rivers.
There she goes.
The only deadly shark
that can live in fresh water.
They are so close to us.
Yet we know so little about them.
Dr. Ryan Daly studies
bull sharks in South Africa.
He wants to know why bull sharks
are such good survivors.
Ryan specializes
in shark migration.
Where they feed and breed,
and how that affects their conservation.
For his work, Ryan catches
bull sharks...
...and tags them.
We tag bull sharks
to find out...
...where they go
and where they stay.
So we know their refuges
and the risks...
...during migration.
He gets close to predators...
...that other people
should avoid.
After eight years of tracking...
...he knows bull sharks
travel almost 1,600 km a year.
He suspects they go
much further.
Ryan is doing research
in southern Mozambique.
Nearly 5 km off the coast of Ponta Do
Ouro is a shark hotspot.
A healthy reef full of food...
...is a beacon for predators.
And perfect for researching sharks.
Ryan wants to identify some unique animals.
This way he knows
which sharks live here.
There are so many sharks there.
Five blacktip sharks, some
tiger sharks, and many hammerheads.
It's teeming here.
Ryan is looking for bull sharks.
Big ones.
He records how they hunt
and compete with each other.
Ryan takes his research a step further.
It's almost impossible
to see the world through their eyes.
But with recent techniques...
...we can attach cameras
to sharks to film it.
First, he has to
catch his research assistant.
Bull sharks are difficult to catch,
they sense it.
Bite.
To attach the camera,
the shark must be exhausted.
In a trance-like state,
he collects data.
She has to be on her back.
Looks good.
Ryan takes a photo
before she disappears again.
The camera on the fin will work
once everything is back to normal...
...in 12 hours.
For the first time, the behavior
of a bull shark...
...is recorded in the Indian Ocean.
No human interference.
Just seeing what the bull shark sees.
Viewing prey.
Other sharks.
Blacktip sharks.
Huge tiger sharks.
And, also for the first time...
...a bull shark
filming other bull sharks.
All predatory fish...
instinctively go
for an abundance of food.
Five thousand giant trevallies.
Experienced predators
and a formidable enemy.
They are over 80 kilos each...
and not afraid of sharks.
Trevallies use sharks
to get rid of parasites.
They are also fast.
Not an easy catch.
Every year, around the same time...
just before a full moon...
trevallies come to
Mozambique for their reproduction.
For Ryan, this ritual
is a golden opportunity.
So many big fish.
All together, unbelievable.
It never gets boring.
Thousands of trevallies should be
an unlimited buffet.
Ryan doesn't see any predatory behavior
on the camera yet.
He needs more footage.
That can be done more easily.
We have a new camera...
with a unique perspective
of what the shark sees.
We don't need to catch the shark.
We feed the shark bait. It drags
the camera for about 6 hours.
A blacktip shark
grips the camera first.
Not what Ryan expected.
But an opportunity
to see something new.
The footage shows how the sharks
swim next to each other...
and sometimes even ram each other.
Sharks are very competitive.
But also strategic.
Here come the bull sharks.
Blacktip sharks and bull sharks
surround the trevallies.
The bull sharks are much bigger.
Higher in the food chain.
Like the police on patrol.
Blacktip sharks stay close.
They are waiting for something.
Bull sharks, tiger sharks,
hammerheads and blacktip sharks...
are near a difficult predator.
A school
of 5,000 giant trevallies.
The bull shark's favorite.
After almost 10 years of research...
Dr. Ryan Daly knows
that at least 20 bull sharks...
permanently live
in the waters around Mozambique.
In the summer,
when the trevallies spawn...
many sharks come here
to feast.
There are more scalloped
hammerheads than bull sharks.
They come for the smaller bonito,
not for the trevallies.
Blacktip sharks do.
Bull sharks can open their mouths wide enough for large prey.
Even smaller sharks.
All those sharks, amazing.
Everyone avoids
the bull sharks.
The bull sharks are at the edge
of the school.
And looking for an easy target.
They only need one trevally
a week.
Nowhere are there so many bull sharks
together as here.
Predator versus predator.
A fish that isolates itself
is immediately eaten.
It's a strategy of attack.
'Survival of the Fittest',
the ocean version.
Fit trevallies
reproduce.
The old and sick
are eaten.
Ruthless.
Wow, a bull shark tearing a fish
apart with so much force.
After spawning, the trevallies
spread out.
The sharks too.
The question is, where do they go?
Ryan once tagged a bull shark...
...that traveled 1,600 km to
northern Mozambique, and back.
Another entered
the waters of South Africa.
Even the strongest travelers
face risks.
During migration, bull sharks face many dangers.
Fishing lines, shark nets...
to thin out the sharks, and shark fishers.
More sharks are caught
because of their fins.
Humans are the bull shark's greatest enemy.
But not the only one.
When the hunters enter fresh water...
...there are problems too.
These tourists are getting
the experience of a lifetime.
Hippopotamus versus bull shark.
The most powerful bite
of any mammal.
Against the most powerful bite
of any shark.
About 240 km south
of Ryan's research...
...at the St. Lucia estuary.
One of Africa's largest
tidal wetlands.
A watery mix
of fresh and salt.
Shallow, warm.
Perfect for bull sharks.
And a unique encounter
during a safari.
This shark was trying to catch a fish
and encountered hippos.
Africa's deadliest large land animal...
...and a clue
to a mystery.
We know bull sharks also
look for food in rivers.
There are plenty of rivers
on South Africa's east coast...
...where a bull shark
can swim.
Hidden on the Wild Coast...
...a pristine wilderness.
Untouched, from sea to source.
Such a forested sanctuary...
...is an unlikely place
for marine life.
And for a shark researcher.
Ryan knows there's a guest
from the ocean...
...that can bring him closer
to the bull shark.
You often see
barracuda in rivers.
They can use them
as a nursery.
Or kill sea parasites
in fresh water.
But 200 together, that's strange.
Horse mackerel are found here.
And they form a unique school here.
It's a mystery why
the horse mackerel are here.
Not only does an ocean animal
adapt to fresh water.
Horse mackerel must
overcome the tides...
and swim against rapids.
Large predators
cannot follow the prey.
Smaller ones can.
They are here.
Baby bull sharks.
This is fascinating. You're in the
forests, past rapids.
Actually upstream
of the river.
How do young bull sharks
get so far inland?
After a gestation period of 10 months...
females give birth to one to three young
near the river mouth.
Her work is done.
The baby bull sharks
swim upstream...
away from ocean predators.
Now they have to arrive.
They are mysterious.
Bull sharks are rarely seen.
This is another first.
I've been studying
bull sharks for over 10 years.
I've never seen young
in a forest river...
miles from the ocean
in such an environment.
The perfect habitat
to grow big and strong.
Ryan has found a new nursery.
When the baby bull sharks are big
enough, they go to sea.
Where will they enter next?
The bull shark. One of
the three deadliest sharks.
The great white and tiger shark
are more notorious.
Only the bull shark enters
human territory.
Watch out.
Stealing fish...
and growing up in fresh water,
miles upstream.
Opportunistic,
unpredictable, misunderstood.
Dr. Ryan Daly is with the bull sharks.
He wants to know where they go to eat
and breed.
This way he can protect them.
Bull sharks are seen as
murder machines.
They are apex predators
in our marine ecosystems.
They keep the ecosystems
in balance.
Bull sharks go to Mozambique in the summer
to feed.
Even for sharks,
travel is risky.
Dangers are everywhere.
How do these sharks move
so successfully?
What is their habitat?
To find out...
Ryan goes to the southwestern
point of their habitat in Africa.
The sleepy town of Infanta...
...on the busy Breede River.
At least 30 bull sharks live here
in the summer.
People go there on vacation.
Like Long Island in New York
or the Outer Banks in North Carolina.
All these people and all these sharks
in the same place, madness.
It's incredible that everything is so peaceful.
Hopefully, it stays that way.
Sharks and people
going their own way.
Ryan wants to catch a shark...
...and attach a long-term transmitter.
This will stay on for 6 months
to a year.
On a specific date, it will detach
and transmit data.
Hopefully, we'll know
where they're going then.
Time to catch another shark.
Ryan is working with Dr. John
Filmater, a marine scientist.
It's a tricky job.
This is shark bait.
Now we wait.
A big shark grabs the bait.
Good, some extra pressure.
Perfect, he's a bit angry.
He's furious.
He has a lot of energy left.
He needs to exhaust him first.
A formidable predator
with a short fuse.
He can explode at any moment.
My God.
Until the shark is stuck next to the boat,
anything can happen.
Whoa. There, yeah.
He's getting angry.
- That face.
Watch out.
Male.
He's shaking his head violently.
- Tail up.
It's a monster.
Well done, very good.
We always check if water is flowing
over the shark's gills.
Time to flip him over.
The nearly 3-meter shark
immediately calms down.
It's a big shark.
Has he been weighed?
297 cm.
- Okay.
Jesus.
A small incision
for an internal acoustic tag.
Is that okay?
- Tag this too.
On its back, the shark
is in a trance.
If he turns over too quickly,
there will be problems.
Watch out.
A 2.9-meter bull shark...
in a busy river.
Dr. Ryan Daly wants
to find out the migration patterns.
And see where he's going.
He's close, that's good.
A satellite tag on the dorsal fin
monitors his movements for a year.
It turns on automatically
at 5 meters depth.
He is
released from the water.
Here we go. Turn over.
Not yet, say when.
Ryan helps the shark back.
Watch out.
For 7 days...
tags the team four
large male bull sharks.
By tagging bull sharks,
we discovered...
that they swim at least 32 km
up the river.
Up and down, almost every day.
Bull sharks,
swimming in a river...
surrounded by farms
and holiday homes.
When it gets colder in winter,
the sharks go to the ocean.
We thought they were going to places
with more bull sharks.
To the coast.
The opposite happened.
Once out of the river...
they went to northern
Mozambique, 3200 km away.
Ryan made
a great discovery.
The sharks don't go alone,
but leave the river together.
Like bulls stampeding.
They swim 3200 km
in three months...
all the way to Northern Mozambique.
That's much further than Ryan thought.
The four return in time for
the kingfish on the south coast.
The previous record for bull sharks
was 3200 km.
The four tagged sharks traveled
4800 km for the kingfish.
A new record.
Ryan doesn't know if
his research subjects are still alive.
And if they will return
to the Breede River.
They can only find out...
if Ryan and John go back to
the place where they tagged the sharks.
They hope for a signal
from the transmitters.
We are at the spot.
Let's see if there's a shark.
With a hydrophone,
the acoustic tags can be heard.
If a shark is within 400 meters,
we'll know.
Okay.
Come on, shark.
The tags emit a signal every 40 seconds.
Is that something?
No, false alarm.
I hear something.
One of the sharks.
- 5-0. Awesome.
One of the male bull sharks.
He was 286 cm,
just under 3 meters.
It's one of our big males.
That shark has
traveled at least 2900 km...
north.
Turned around, and came back
to this spot.
A journey of almost 6500 km.
Within a year, he returns
to the same spot.
This is bizarre.
The four tagged males
are in the river.
Two of them arrived
within 30 hours of each other.
They traveled a combined
6500 km.
The longest bull shark migration
ever recorded.
Double the previous record.
Bull sharks migrate
from sea to river...
and back to sea, every day.
In coordinated migration patterns.
Are bull sharks deadly
to humans?
An apex predator...
that is threatened wherever
it goes?
Running a gauntlet through
competition and predators...
to feed
and reproduce.
This year, and every year,
all over the world.
Translation: Elly van der Meijden