Original subtitles

Sharks - nature's perfect solution to an underwater life.

They've been swimming in the oceans for over 400 million years...

..and, as top predators,

play a vital role in keeping our seas healthy

and productive.

But they're coming under increasing pressure,

millions are hunted and killed every year.

Never have sharks needed friends

more than they do today.

For three weeks, I've been in the Bahamas for Blue Planet Live.

Watching,

monitoring,

and diving with one of the richest shark populations on the planet.

I want to reveal why sharks are thriving here

and find out if there are lessons to be learned

from these crystal clear waters

that could help secure their future elsewhere around the world.

Our blue planet is home to more than a thousand species of shark...

..and their cousins, the rays.

They come in a myriad of shapes...

..and sizes...

..and are found across all of our oceans...

..from the tropics...

..to the Arctic...

..and into the deep abyss.

There are a few places where the number and diversity of sharks

is unparalleled.

The Bahamas is one of them,

earning it the title of shark diving capital of the world.

700 islands are scattered over 84,000 square miles of ocean.

This location is unique -

perched on the edge of deep water,

where the seabed plunges to a depth of 4,000 metres.

The meeting of shallow water and deep, open ocean

leads to a profusion of life.

In winter, the resident Caribbean reef sharks

and bull sharks

are joined by visitors,

bolstering the shark and ray population to 78 species.

In 2011, the Bahamas were declared a shark sanctuary,

making it illegal to fish for or kill any species of shark.

These protected waters offer me a unique chance

to get close to these amazing top predators...

..and to see first-hand what it takes

to have a healthy, thriving population of sharks.

Within seconds of coming down here,

I'm greeted with one of the most dazzling displays

you'll ever see underwater.

There's probably two or three different sort of shark

at this location, but the dominant kind

is going to be the Caribbean reef shark.

And I can already see at least 20 of them here in the water around us.

I guess the first question that people would ask would be,

isn't it dangerous, isn't it risky to be surrounded

by this many apex predators?

And I have to say,

I feel just as comfortable being in here,

surrounded by all these extraordinary animals,

as I would do going for a walk with a pack of poodles.

These animals are so good at sensing their environment,

they know what's prey in the water around them,

and it's not us.

They may well swim in close but at the last second,

they just bank away.

They could not be less interested,

and the statistics about sharks prove that's true.

Around the world, you're more likely to be killed taking a selfie

than you are to be killed by a shark.

In fact, statistically speaking,

the chance of being killed by a cow, a deer or even a vending machine

is higher than the risk posed by one of these.

Sadly, this abundance of sharks is not typical

across all of our oceans.

This is not a sight that you get to see just anywhere.

So, around the world, we human beings are taking

at least 100 million sharks from the world's oceans

every single year.

In some places, sharks have declined by over 90%.

And in the time it'll take for you to watch this programme,

over 11,500 will be killed.

It's a number that simply cannot be sustained.

If it carries on like this,

then our children will not have the opportunity

to dive in seas like this,

surrounded by these stunning predators.

The Bahamas isn't the only place to offer protection to sharks.

Today, a total of 17 sanctuaries have been created around the world,

covering over 7.5 million square miles.

But this still amounts to only 5% of our oceans.

Sharks need more help,

and if we don't give it to them,

much of the life in our oceans will suffer.

As apex predators,

they remove any sick or injured animals,

keeping fish stocks healthy.

Animals below them in the food chain

are kept in check.

And removing sharks would unbalance whole ecosystems.

Over 3 billion people depend on the ocean for their livelihoods.

It's essential we protect sharks for our sake

as well as theirs.

And a vital step towards this is combatting the reputation of fear

that many sharks still hold.

I always had a passion for the ocean.

I fell in love with scuba diving.

I fell in love with everything.

It was a calling, I think.

Cristina Zenato left her homeland of Italy over 20 years ago,

heading for the Bahamas.

Ever since, she's become an advocate for sharks.

And two decades of diving at one site,

off the island of Grand Bahama,

has convinced her that these animals are a long way from being

mindless killers.

Cristina is known locally as the Shark Dancer...

..and this is her stage.

I love that there is a busy silence.

It is the most peaceful and calming moment of my day.

My babies are Caribbean reef sharks.

I love watching their behaviours

and their interactions.

They appear to me as different

as any other human being that I encounter.

Some of them are more dominant.

Some of them are shy.

And some seemingly seek out a closer encounter with Cristina.

The first time that shark settled in my lap...

..and every time, she settles in my lap,

and I feel her weight over my legs,

that is the most amazing feeling...

..and there's nothing, to this day, that beats that.

You can feel everything about the shark.

You can feel that it's a living, breathing creature

that is aware of her surroundings,

that is aware of what I am doing to her,

that is aware of my touch.

And the suit might actually have a nice feeling to their skin.

These sharks are 8ft long.

I could never force an animal of that size

to do anything or to sit anywhere.

It's their decision to come in,

it's their decision to stay,

it's their decision to go.

There is a total disconnect from humans to sharks.

We can swim in the ocean with sharks in a way that you could never

walk around on the snow with a polar bear following you.

We have to make that connection with the sharks,

understanding they are way, way less dangerous

than many creatures out there.

Cristina's unique relationship with sharks

allows her to do something quite extraordinary.

She can take out fishing hooks that are caught in their mouths.

Over the years, she's removed more than 300 hooks.

We must change our ways,

because we need to protect the oceans

and we need to protect the sharks.

And when you reach that message,

then you have a victory.

A greater understanding of these misunderstood creatures

can undoubtedly help sharks.

And with such a diverse and healthy population on its doorstep...

..the Bahamas has long been at the forefront of global shark research.

The Bimini Biological Field Station,

or Shark Lab,

has been increasing our knowledge of sharks and rays

for the last 29 years.

Heading this institute is Matt Smukall,

who's had a passion for the marine world

for as long as he can remember.

MATT: My first memories were snorkelling in the Florida Keys.

Growing up, I always had an affinity and a connection with, you know,

spending pretty much every weekend and all summer in the ocean.

My favourite group of animals are the sharks.

That's what originally brought me to the Shark Lab,

that's what makes me enjoy waking up every day

and doing this job.

The Bimini Shark Lab started in 1990.

Right now at the Shark Lab, we're studying everything from

southern stingrays to bull sharks, tiger sharks,

lemon sharks, hammerheads,

but we take it from a very ecosystem-driven model,

where we want to understand

everything that's going on around Bimini

and how that's impacting these big sharks.

One of the biggest and most impressive species,

and the focus for a number of Shark Lab studies,

can be found a stone's throw from the heart of a busy marina.

These are bull sharks...

..drawn in by the scraps discarded from fishing boats.

They spend much of their lives in murky estuaries...

..so this clear water gives me a unique opportunity

to see them up close, and Matt a chance to learn more

about this little understood species of shark.

I'm here on the bottom of the harbour

and, as you can probably see,

I'm absolutely surrounded by bull sharks.

This is an opportunist that has a very wide array

of different kinds of prey,

so they'll feed on fish, on rays, on birds at the surface,

on dolphins, they'll even bite through the shells of turtles.

Now, all the sharks that I'm seeing around me at the moment

are females, I haven't seen a single male.

And they're quite big in the belly.

Why the warm waters of the Bahamas attract

these large, slightly rotund females

has long been a mystery.

One Matt and his team from Shark Lab are hoping to solve.

But to do that, they first have to catch one.

To go ahead and catch, say, a big female bull shark,

what we'll do is drop a baited hook, throw it right in,

and they pretty quickly will normally take the hook.

All right. On, on, on.

Hooking the bull shark is the easy part.

As soon as they start running around with the balls and the rope,

this is a bit of a dance between the person bringing it in

and the shark.

We have to be very careful

cos they are not expecting to be caught and handled by humans.

In order to help, number one,

for human safety but also for shark safety,

we'll put a tail rope on.

That helps to secure the shark to the boat.

Quick! Quick!

INDISTINCT CHATTER

With the shark safely harnessed and calm,

the team can take the measurements

and assess the shark's condition.

And one of the most crucial jobs

is to find out her reproductive state...

..using a very familiar method.

Ultrasound.

I think there's something right there.

You can see it moving slightly there.

That looks like the pup.

Over 50% of the females that we catch are actually pregnant.

They have paired uterus,

so we check both sides.

And we're going to try to count

the number of pups that we can see,

the size of pups in both sides,

to get a better understanding of her offspring litter.

After ten months, bull sharks give birth to up to 13 pups.

These fully-formed pint-size sharks

are then left to fend for themselves.

Now that we've confirmed she's pregnant,

we're going to go ahead and let her go on her way.

Give her a push.

All right, nice job.

At the end of the procedure,

it's great to be able to give that shark a push.

We're blessed here with beautiful, clear water

and we can always observe the shark,

basically follow her to make sure that she's swimming strong

and that she's doing well.

And it's not just the visiting bull sharks

who are carrying the next generation.

Many other species found in the Bahamas

are also pregnant.

It's thought that the warm waters and rich feeding grounds here

help raise the shark's metabolism and speed up gestation.

MATT: We know a lot about sharks but there's so much more

that we still need to understand.

We still don't even know some of the basic reproductive biology,

some of their life history things,

and these are all very important for conservation.

This is what's really going to help us manage

the next generation of sharks.

And it's managing this next generation

and the habitats that are essential to their survival

that's vital to maintaining a healthy population of sharks.

This tangled mass of roots is the mangroves.

It's an environment that changes constantly

with the tides throughout the day.

And provides the perfect spot for baby marine animals

to hide out in.

I'm joining Clemency White from Bimini Shark Lab

to see how these mangroves are key to the success of sharks

in the Bahamas.

Whoa! Look at that!

Yep, they're all waiting for us.

Baby sharks!

That's absolutely incredible.

These are lemon sharks.

And they've been studied by Clemency and her fellow researchers

for over 30 years.

It looks like they want to be fed.

Yeah, we actually have a little bit of squid

if you want to give it a go.

I...I would genuinely love to.

So, Clemency, how old are the sharks we're looking at here?

Most of these sharks are in their first few years of life.

So the majority of them will be maybe two or three years old.

And some of those larger sharks you can see

are maybe four or five.

So this is a refuge.

This is an area that's pretty much only accessible

to these guys at high tide.

So that small, narrow walkway that we walked in,

bigger sharks can't use that.

What sort of things are they taking shelter from?

The biggest predator of juvenile lemon sharks is actually

lemon sharks themselves, adult lemon sharks.

So they're cannibalistic? Yes, they are cannibalistic.

And also other large sharks, so maybe bull sharks,

other species like that.

So this genuinely is a nursery,

it's a place where the youngsters are safe from other...

Oh! That went right between my legs.

Yeah. I should be wearing a cricket box or something. Um...

Are you OK?

THEY LAUGH No!

Seriously, they're all making a beeline

straight between my legs.

This would be a disaster if

all the things I've done in my life

and I was to get savaged in the goolies by a baby shark.

Well, they must like you.

That one there's a decent size.

Yeah, so they'll be pretty loyal to the mangrove that they were born in

until they're about 13 years old, when they sexually mature.

Then they'll also come back to give birth here as adults.

So they really rely on those mangroves

for their entire life cycle.

What are the main threats to mangroves in the Bahamas?

So, a lot of places, even in Bimini,

we see the mangroves are being removed to facilitate bigger hotels,

bigger resorts, and that in itself means

that these pups will still be born in the same place,

they'll still be using the same areas,

but they won't have that same security from the larger fish.

So, lose the mangroves and you lose the lemon sharks? Yep.

It may not look like any other nursery you've seen before,

but you can see how vital this environment is

to these rather wonderful and surprisingly cute animals. Mm-hm.

All over the world, baby sharks and rays seek refuge

in mangroves, seagrass and estuaries.

Throughout their lives,

sharks need a whole variety of ocean habitats...

..and protecting these is essential

if shark numbers are to bounce back.

Most sharks take many years to reach sexual maturity.

Female great white sharks need a whopping 33 years

before they can breed.

This, combined with their tendency to produce just a few offspring,

means that shark populations are extremely vulnerable to overfishing.

Right now, sharks are being killed at a staggering rate.

They're deliberately caught for food.

And accidentally caught in nets or long lines

set for other species.

They're also harvested in their millions for their fins,

to make shark fin soup -

a delicacy that's seen shark fins sell for $650 a kilo...

..fuelling a cruel, wasteful trade,

which sees the rest of the shark being thrown back into the sea...

..often still alive.

A third of all shark species are now threated with extinction.

And this is being driven by human activities.

But all is not yet lost.

There is hope.

And it comes from the fact that these sharks

can be worth more alive than dead.

I'm heading 12 miles north of Grand Bahama

to a site of global importance.

This could well be the best shark dive in the whole world.

And what happens here is key to securing the future of sharks

right across the world.

Whoa! Great hammerhead! Amazing.

Look at that. Powering straight in.

That is just extraordinary.

Drawn to the warm, productive waters,

this is also the best place in the world to see tiger sharks.

A tiger shark is unmistakable in form.

It has the dappling running down its sides,

which gives it its tiger name.

They'll feed on just about anything they can find in the water.

And with those teeth, they can even go through the shell of a turtle.

This is absolutely dazzling.

I don't know which way to look!

Tiger sharks, great hammerheads,

lemons, bull sharks, reef sharks.

It's the world's greatest safari,

it just all happens underwater.

Here and throughout the Bahamas,

sharks are drawn in with food

so tourists can reliably get close to them.

Feeding of sharks is a hotly debated topic.

there's people who think that it's a bad idea

and might, potentially, change the behaviour of sharks,

and I can totally see that,

but there's no doubt that shark tourism here in the Bahamas

is incredibly important.

Each year, 20,000 people come to the Bahamas to dive with sharks...

..making it the largest shark diving industry in the world.

Shark diving here in the Bahamas

is worth an estimated $114 million every year to the local economy.

Unquestionably, the sharks are worth more alive than they are dead.

And that's hugely important

for the survival of these extraordinary animals.

INDISTINCT CHATTER

All across the world,

shark tourism is fast becoming a thriving industry -

not just for dive operators,

but boat drivers, hotels, restaurants,

and bringing much-needed income to shark hot spots

from all over the world.

I came from Philadelphia today

to swim with the sharks.

It was just invigorating.

It's a whole 'nother world down there.

I'm from Argentina.

It was a long trip but it's amazing.

It's estimated that well over half a million people

come to watch sharks every year.

Not only are sharks gaining more advocates,

but they now hold an indisputable monetary value.

And this will certainly help to secure their future.

Shark conservation is something that will require human effort

for many years to come.

And right here in the Bahamas,

there's a very special project that's training up

the next generation of shark champions.

Marine biologist Jillian Morris has set up Sharks4Kids.

A charity to show children across the Bahamas

that sharks are something to celebrate,

not to fear.

I really believe that the best way to change the way people see sharks

is to let them get in the water.

We take kids out to see sharks

and a lot of them are very afraid.

They don't want to get off the boat,

they don't want to step off the beach,

and we get them to put a mask and a snorkel on,

and we kind of ease them in.

And then they're snorkelling around

and they're seeing the sharks and the rays up close

and realising they're not trying to attack them,

that they're actually really beautiful animals.

It's really incredible to see students go from being terrified

and not wanting to get in the water,

to we're having to drag them out -

"We've got to go. It's time to go home."

And to see that transition happen right in front of you,

very quickly, is really, really powerful.

The Bahamas is a shark sanctuary,

which is incredible and has set a standard around the world

for shark conservation, shark diving, shark science,

and so it's vital to have the locals involved at all levels,

from kids to adults,

to protect the future of this sanctuary

and the sharks here in the Bahamas.

While places like the Bahamas offer protection

when the sharks are here...

..once beyond the invisible boundary of the sanctuary,

sharks are immediately vulnerable.

Knowing where they go in this vast, featureless landscape

is essential if we're to offer them protection.

A few miles off the coast of Andros,

the endless blue is interrupted...

..by a naval buoy.

This lone beacon is a big draw for passing travellers...

..providing shelter for schools of fish...

..which attract the hunters.

Top of the food chain out here are these -

silky sharks.

They get their name from the silky sheen of their skin.

So little is known about the migrations

of these open ocean drifters.

When shark biologist Tristan Guttridge

heard rumours of this location,

it was an opportunity for him to try and uncover these secrets,

which might just help protect these threatened sharks.

There's nothing that gives me more energy

than being in the water with sharks.

These silky sharks, they're a completely different type of animal.

There's just something about them that, you know,

brings them closer and draws them in to you.

They have this curious, bold personality

and it is a bit intoxicating.

And I love it.

But this inquisitiveness is this shark's Achilles heel.

Silkies are in trouble globally.

And, in fact, silky sharks are the second-highest caught shark species

in the world.

Industrial fishing often uses floating objects,

working just like the naval buoy,

to attract an aggregate fish like tuna

in the open ocean.

But they don't just attract tuna.

Every year, hundreds of thousands of silky sharks

get accidentally caught.

I see the evidence of the pressures that these animals are under

from the hooks in the mouths

and the leader wire that's coming out of it,

you can see these sharks are...they're in trouble.

They've got a lot to deal with out in the open ocean.

Tristan wants to catch a shark

in order to attach a tracker,

which will reveal, for the first time,

where these curious sharks go.

One method that we can use to catch silkies is

that you can actually bend the top of the tail over

and it sends them into this kind of bizarre trance-like state.

And if you turn them upside down at the same time,

then they're almost playing dead, they're just out.

It's not fully understood why,

but many shark species enter this trance-like state

called tonic immobility when upside down,

enabling the team to tether the shark next to the boat.

INDISTINCT SPEECH

A satellite tag is fixed to its dorsal fin.

Every five minutes, this tag will record important information,

including depth, light level and water temperature.

After 30 days, it'll pop to the surface

and start sending a stream of data to Tristan.

TRISTAN: There's nothing more exciting than the few days

when we know a tag is going to pop

as to where it's going to pop.

It's very important that we learn more about their migration patterns,

their population structure,

in order to try and put management measures in place

to improve their conservation.

They deserve to be on this planet.

Like us and like anything, they deserve to be here

and we, as humans, should be responsible.

So it is critical that we learn more about these animals

and it's critical that we protect them.

Tristan's tags have shown that these sharks not only traverse oceans...

..but dive down to feed at depths of over 400 metres.

Showing that if we want to protect sharks,

we need to look after every part of our oceans.

Satellite tags are now being deployed

on many different species of sharks

and they're revealing some incredible journeys.

The greatest distance ever recorded

was by a great white shark named Nicole,

who swam from South Africa to Australia

and back again -

a staggering 12,000 miles in just nine months.

While understanding where these top predators go is important,

another vital piece of this conservation puzzle

is understanding why they go.

Just off the coast of Bimini in the Bahamas,

there's a dive site that, for a few months each year,

provides a close encounter

with one of our most iconic and well-known migratory sharks.

This is the only place in the whole world

where you can reliably see great hammerhead sharks.

So we have dozens of sharks around us.

Most are like this one here.

It's a nurse shark.

And the reason they have this name is that when they're feeding,

they make a sucking noise,

kind of like a baby when it's nursing,

when it's feeding.

You can see that they're quite content lying on the bottom.

They can pump water through their gills

and they don't have to swim constantly in order to breathe,

like many other sharks do.

But this creature that's heading towards us now,

that really is the main event.

It's a great hammerhead.

There are at least three of them around us right now.

And while the nurse sharks are quite dopey

and just hanging out on the bottom,

this is a far more targeted predator.

There is nothing else quite like a great hammerhead shark.

The shape of the head,

the giant dorsal fin.

It's so unusual-looking

and, yet, so perfectly adapted to its job.

Shaking the hammerhead from side to side

as it moves along the bottom,

sensing the potential moving muscles of its prey.

Perhaps the most incredible thing about this

is that great hammerheads are an endangered species.

There are very, very few of these almighty sharks left

in the whole world.

And right now, I think we have seven.

I don't quite know what to say.

I'm completely blown away.

These great hammerheads are seasonal visitors,

spending the winter months here,

between December and April.

Many return year after year.

The scientists have at least 30 individuals

that they know by name...

..and not just by name, but by personality

and character and behaviour.

And even in the short time since I've been here,

I've been starting to get to know the individual personalities here.

You might not think of a shark as having a personality,

but they very much do.

Some of them are quite bold and dramatic,

and others are real gentle giants.

This almighty great hammerhead here is called Gaia.

She's a female.

And the largest that they see here.

What an absolute beauty!

I will never, ever get tired of this.

Holy Moley!

HE LAUGHS EXCITEDLY

For five months of the year,

these hammerheads are seen virtually every day.

But in April, they suddenly disappear.

One female was tagged here at Bimini.

She then headed north to the coast of the Carolinas,

before turning south again,

ending up off the coast of Florida.

A journey of over 3,000 miles in less than two months.

But what's causing these ocean wanderers to travel so far

and so fast?

I'm taking to the air to find out.

This is Palm Beach, Florida.

It's a playground for the rich and the famous.

But little do they know that just off the coast

is one of the greatest gatherings of large predators on the planet.

These are blacktip sharks.

Massing in their thousands

before migrating north to their summer feeding grounds

off the coast of North Carolina.

It's these sharks that attract a host of larger predatory sharks,

including the great hammerheads,

which travel from the Bahamas to feast on this bounty of food.

I've joined Stephen Kajiura,

a professor at Florida Atlantic University.

Each year, he takes to the air to monitor the number of sharks.

Just a slick of sharks going on all the way parallel to the coast.

That is absolutely fantastic.

They stand out so well against the sandy bottom, don't they?

That's one of the reasons we're so successful

with the aerial surveys here.

We have clear water, a light, sandy bottom,

we're able to see everything.

And they're in nice and shallow. They're nice and shallow.

They really make it easy for you, don't they?

But all's not what it seems.

Stephen's long-term study has shown

that this spectacular migration is changing.

And this could have serious consequences.

I've been doing these aerial surveys for the last nine years.

We've seen this decline in the number of sharks

over the past nine years.

At the same time,

we've seen an increase in the water temperature down here.

They have a very narrow thermal tolerance.

They like water between about 21 and 25 Celsius.

And as water temperatures keep rising,

we're getting fewer and fewer sharks coming this far south.

Presumably the blacktips that you've got here,

there are constant interactions between them

and the larger predatory sharks

like the tigers, the great hammerheads and the bulls.

How is that likely to be affected?

That's a really good question.

If you don't have these blacktips sweeping down here

in the tens of thousands every spring,

there's no food for the big hammerheads

and these blacktips are not eating all the bait fish.

And so, we don't even know what might happen.

You know, these ecosystems

have remained pretty much unchanged for millennia,

but they are dramatically changing in my lifetime,

and where that will lead we simply don't know.

The rate at which our seas are heating up is accelerating.

And the effects of this warming are now being felt

in every one of our oceans.

Sharks are under pressure from all sides -

fishing, their habitats changing,

and now, in these protected waters,

their fellow sea creatures.

Recently, an unwanted visitor has appeared in Caribbean waters.

This is a lionfish.

A predator that could eat fish populations out of existence...

..threatening the future of the resident sharks.

Ten years ago, I saw for myself

just what devastating predators they are in their native waters

off Malaysia.

There's a small fish over here.

The lionfish has spotted it.

This could be trouble.

It's moving in.

Oh! Unbelievable!

Did you see the speed of that strike?

Lionfish eat about 70 different species of fish and invertebrate.

If it fits in their mouth,

they'll eat it.

It did it again.

This is just the most astounding display of feeding

I think I've ever seen.

Such an elegant fish is, unsurprisingly,

a favourite of the aquarium trade.

And in the 1980s, a few unwanted pets ended up being released

in the seas off Florida...

..with devastating results.

In just over 30 years, they've spread from coastal Florida

with alarming speed.

They're now found as far north as New York

and south to Brazil.

This is the wrong fish in the wrong place

and at the wrong time.

And it's threatening to unbalance the already fragile system

upon which the sharks depend.

This is a growing problem

that people like marine biologist Alex Fogg

are trying to find a solution to.

ALEX: The reefs have changed actually quite a bit

since I first started diving.

I started diving about ten years ago and in this area in particular,

lionfish weren't here yet.

When we first started seeing lionfish on the reef

it was one here or one there, but now you go to a reef site

and you can see upwards of 100 lionfish.

I mean, they're here eating everything.

It's like an all-you-can-eat buffet, if you will.

They're not just voracious hunters,

they're prolific breeders too.

A female lionfish can lay more than 20,000 eggs every four days.

They can reach densities of over 200 adults per acre of reef

and that quantity can hoover up nearly half a million fish a year.

This is having a devastating effect on an already fragile ecosystem.

But Alex has a plan.

You can't really catch them on hook and lines.

There's really only one way to harvest lion fish

and that's through diving and harvesting with spears.

And all these fish don't go to waste.

Lionfish are definitely one of the most environmentally-friendly fish

that you can actually eat.

This is one fish that we want to eat into extinction.

Hey, Chef. Got you a bunch of fish. Right, man. Appreciate it.

Thank you very much. Thank you.

Alex hopes that by making a commercial market

for these lionfish, more will be caught...

..allowing reefs and sharks to recover.

Ten years down the road from now,

lionfish are still going to be here.

Are they going to be at the numbers that we have today?

I'm not sure. I think that if we can just get lionfish to a point

to where the ecosystem can actually deal with it,

or they find their space in the ecosystem,

that's our best bet.

The market for lionfish in restaurants is growing.

But to fully combat this invasion,

things are being taken a step further.

Along the coast of America, locals have created lionfish derbies.

The aim - to collect and remove as many lionfish as possible.

Each fish is measured and prizes are awarded for catching the most,

the biggest,

and the smallest lionfish.

Hundreds gather to share in the prize...

..and eat the catch.

These derbies serve to reduce numbers,

as well as raising awareness of a fish

that threatens the ocean ecosystems upon which the sharks rely.

INDISTINCT CHATTER

Our blue planet is defined by its oceans...

..and if they are to stay healthy and productive,

we need a healthy population of sharks.

At present, sharks are being killed faster than they can reproduce

and we're set to lose some of our most iconic species

in the next 50 years.

But across the globe,

many people are working tirelessly to uncover the secrets of sharks

in order to save them.

People are seeing sharks in their true light

and starting to appreciate them

for the essential role they play in our oceans.

There is still much work that needs to be done...

..but, for now, there is hope...

..for our oceans are packed with the ingredients for recovery.

The seas are full of tiny, microscopic life

just looking for somewhere to fix and make home.

This is the Sapona.

It was grounded here in a hurricane many decades ago,

and ever since, it's become a living reef...

..absolutely bursting with life.

So many fish.

So beautiful.

The superstructure makes a perfect habitat,

places for them to hide from predators.

And it's covered with encrusting soft corals and fans.

All sorts of animals take up shelter inside.

Oh, stingray!

It's like swimming through the ribcage of an almighty whale

lying on the bottom.

Incredible.

This is the basis of the food chain upon which sharks depend.

If we protect our seas then life will bounce back in our oceans,

if we give it the chance.

The interconnectedness of our oceans and their inhabitants

is intricate and far-reaching.

Sharks depend on the creatures around them

as these creatures in turn

depend on the sharks.

They've been stalking our seas for at least 400 million years.

I hope they've got a few million more left in them yet.

The Bahamas are at the forefront of shark research and conservation.

And lessons learnt here now need to be applied

all across our blue planet.

The future of sharks is in our hands.

And it's for us to decide where this sharks' tale goes next.