(SWEEPING ORCHESTRAL MUSIC)
(DRAMATIC ORCHESTRAL MUSIC)
NARRATOR: Of all the creatures in the deep blue sea,
the one that never fails to strike fear in the heart
is the great white shark, or white pointer.
(DRAMATIC ORCHESTRAL MUSIC)
Hollywood has made these animals infamous
through fictional films such as 'Jaws' and 'Dark Tide'...
..but make no mistake,
the premise behind these movies is real.
Great white sharks are natural born killers,
lurking in the coastal surface waters
of all the major oceans on Earth.
They prefer temperate waters,
but are often sighted in the tropics.
(DRAMATIC ORCHESTRAL MUSIC)
Two locations that are well known for great whites
are South Africa
and the Great Australian Bight,
off the coast of South Australia.
(DRAMATIC MUSIC BUILDS)
In both places, ocean currents carry water from Antarctica
laden with tiny organisms that form the basis of a complex web of life.
Plankton attracts fish, fish attract seals,
seals attract the great white shark.
And the great white sharks, well, they attract people.
Cage diving with these charismatic creatures
has become big business.
During seal breeding season,
the supply of shark food is almost unlimited.
Despite their formidable appearance,
great white sharks are not a huge threat to humans.
It is true about 100 people a year are attacked by sharks,
and probably about half of those are made by great whites...
..but most are not fatal.
Zoologists now know that these animals are naturally curious,
and most injuries to humans are just sample bites.
Great white sharks prefer to prey on sealions,
small-toothed whales, and sometimes other sharks.
They really are the ultimate hunters.
Shaped like torpedoes,
they can tear through the water at 15 miles per hour.
Fully grown great white sharks have around 300 teeth
arranged in several rows.
The ones at the front are knifelike, with serrated edges.
Intimidating and effective.
Fortunately, the cages used on dives such as this
protect those who seek the thrill of a close encounter
without any associated risk.
The great white's sense of smell is no urban myth.
They can detect and home in on a small amount of blood
from as far as 5km away.
Unlike most fish, these incredible sharks are warm-blooded,
which is why they can maintain their body temperature
in seas all over the world.
(JAUNTY ORCHESTRAL MUSIC)
Cage diving with great whites is the ultimate adrenalin rush,
but the experience also allows scientists
to increase their understanding of this remarkable species
and its place on the blue planet.
Aquariums, which are slowly becoming as popular as zoos
throughout the world,
also afford opportunity for us to learn more about life underwater...
..and to encounter less aggressive sharks
in their admittedly somewhat controlled environment.
The size of the tanks clearly restricts the size
of the creatures that feature in such exhibits.
So, if you want to encounter the biggest fish in the sea,
you'll need to return to the wild.
(HAUNTING INSTRUMENTAL MUSIC)
NARRATOR: Despite their name, whale sharks are not whales,
but it's obvious how the confusion has come about.
They are enormous - 20 times larger than the great white.
Fossils indicate this gargantuan fish
may have been around for 250 million years.
It's a true dinosaur of the seas,
but humans need not be alarmed.
The only prey on this giant's menu is microscopic.
Encounters with whale sharks are awe-inspiring, to say the least,
and one of the most reliable places to see them
is here on Ningaloo Reef,
off the coast of Western Australia.
These gentle creatures swim to the surface to feed on tiny zoo plankton.
So, it's easy to get relatively close to them
just with a mask and snorkel.
Whale sharks gulp enormous quantities of water
into their wide mouths,
then filter out the plankton through a kind of sieve in their throats.
They do have teeth - 3,000 of them, in fact -
but they are barely 6mm long and never used for eating.
Humans discovered whale sharks relatively recently.
The first recorded sighting was less than 200 years ago.
To better understand their migratory behaviour,
and in so doing, afford this species
better protection from illegal fishing,
scientists will occasionally fit an individual
with a radio tracking device,
a relatively harmless procedure that is akin to having your ears pierced.
A less invasive tracking technique uses photo ID.
So, anyone with an underwater camera can contribute
simply by photographing the skin of any whale shark they encounter,
for their spots are as unique as a human fingerprint.
Through this citizen science project,
whale shark specialists have been able to determine
the migratory patterns of individuals
and better monitor the global population.
Whale sharks cruise through Ningaloo every year between April and August,
and they don't appear to be bothered by humans at all.
Ningaloo is one of the longest fringing coral reefs in the world.
It's a beautiful wild place bathed in warm, clear water.
The diversity of life here is bewildering.
Ningaloo lies at the point where the southern temperate waters
meet the northern tropical currents of the Indian Ocean.
It's home to over 200 different corals
and 500 species of fish.
(GENTLE INSTRUMENTAL MUSIC)
This pristine reef is a favourite hangout for another majestic giant,
the manta ray.
Like all rays, these graceful mantas are a type of shark.
Growing to 5.5 metres wide,
they are closely related to stingrays,
but thankfully there's no nasty barb in their tails.
They do have teeth, but they're shaped like pebbles,
and not designed for biting prey.
Manta rays spend most of their time swimming in large vertical loops,
sucking in plankton as they go.
(GENTLE INSTRUMENTAL MUSIC)
Until recently, marine biologists believed
mantas depended almost entirely on plankton.
But research now reveals
manta rays only get about a quarter of their nutrition
from this kind of surface feeding.
They catch the rest of it, mainly fish,
hunting in the darker reaches of the ocean.
Tagged rays have been recorded swimming to depths below 400 metres.
And evidence is emerging that these impressive swimmers
can dive down as far as a kilometre.
Cephalic lobes on either side of their mouths
are actually pectoral fins,
adapted to help mantas funnel their food.
(JAUNTY ORCHESTRAL MUSIC)
Not all of the sea's creatures
are famous for their propensity to kill or good looks.
Some are incredible to encounter
simply because they are so bizarre.
Just off the coast of Whyalla,
in South Australia,
there's a 10km stretch of rock
on the seabed
that, well, isn't particularly remarkable
unless you happen to be here in winter.
This is the only time, and place in the world, for that matter,
where you can reliably see huge numbers
of giant Australian cuttlefish.
(JAUNTY MUSIC CONTINUES)
With bodies, or mantles, around 1.5 foot long,
they are the largest of their kind in the world.
Giant cuttlefish come here every winter to breed
because the seabed is a perfect platform
for females to anchor their eggs.
In true rock star fashion, they live fast and die young,
curling up their ten tentacles shortly after spawning.
Young cuttlefish take 12 to 18 months to reach maturity.
So, they are only sexually active for a single season.
Their primary role is simply to live long enough
to pass their flashy, overconfident genes
to the next generation.
The jack of all performing trades,
cuttlefish have the underwater visual effects department
well covered.
They can change colour in an instant,
and work their way through a kaleidoscopic range of patterns.
They use these skills to help them with camouflage
or to signal alarm,
but during their mating ritual, it's all about showing off
and upping your reproductive stakes.
Cuttlefish have been around for hundreds of millions of years...
..which begs the question,
who is the real alien in this underwater encounter?
The strange new creatures who seek to enter this world
or the cuttlefish they've come to admire?
(TINKLING CHIME MUSIC)
there's a collection of volcanic islands...
..that, in their geographic isolation, have developed habitats
that have enabled many unique species to evolve.
On land, they appear to have little to fear from humans.
Indeed, the reverse appears to be true.
These islands and their incredible collection of animals.
inspired Charles Darwin to write a book
that changed the way we think about life on Earth forever.
They are, of course, the incomparable:
There are 19 islands in the group in total,
and they sit right on the equator.
Their location is key
to the strange and wonderful creatures that live here,
particularly under the sea.
The Galapagos lie in a kind of triangle
created by the meeting of three great ocean currents.
This has a dramatic effect on the weather,
allowing a vast range of marine animals to wind up here.
The famous marine iguana is unique to the Galapagos Islands.
It's the only lizard that lives purely on algae and seaweed
and swims underwater.
They're almost certainly descendants
of the forest-dwelling iguanas of South America.
The theory is storms on the mainland
may have set adrift rafts of sticks and debris,
and a few unlucky land-based iguanas became stuck on board.
They were carried by the ocean current
and dumped here to begin a new life.
Over countless generations,
they evolved the ability to survive by the sea.
Sharp teeth for scraping algae,
a flattened tail for swimming,
and even a special gland
which removes excess salt from their bloodstream.
Birds also rule the Galapagos roost...
..but two of the more striking seabirds
are the frigate, with its extraordinary red throat pouch,
and the blue-footed booby,
easily identified by its outlandish blue feet.
The males are very proud of their blue suede shoes,
and show them off during mating dances.
The guy with the bluest feet usually gets the girl,
and the opportunity to pass on his genes.
The Galapagos Islands are also home
to the world's only equatorial penguin.
They are a small but determined bird,
ungainly on land, but absolutely amazing to witness underwater.
(GENTLE INSTRUMENTAL MUSIC)
One of the most joyous sights in the ocean
can be found in almost all the warm waters of the world.
Dolphins.
At last count,
scientists think we have 38 different species of marine dolphin,
plus another five living in rivers.
Australian has 14 different marine dolphin species,
and some of them are almost too easy to meet.
(UPLIFTING MUSIC SWELLS)
Just offshore from the busy port city
of Adelaide, in South Australia,
dolphins will go out of their way
to initiate close encounters with humans.
The most common species here is the bottle-nosed dolphin.
These sociable animals live in pods, groups of around 12 individuals
that have developed a range of social skills
to survive and support each other.
Communication is key.
Dolphins use a complex combination of squeaks and clicks
to talk to each other.
Their range of hearing is ten times greater than humans,
so they can pick up high-pitched sounds that we are unable to hear.
Dolphins usually hunt in a team,
rounding up schools of fish,
keeping them corralled until everyone has had an easy feed.
Most dolphins in large pods are female
and not related to one another,
although mothers will stay with their young for up to eight years.
(JAUNTY INSTRUMENTAL MUSIC)
Male dolphins form smaller pods of two or three,
and they are thought to become friends for life.
They only approach the females when it's time to mate,
which is often.
Dolphins can actually mate at any time of the year.
When a female gives birth,
the others in her pod will help her,
then go on to play a major role
in protecting and rearing the offspring.
Many marine parks and aquariums around the world
offer opportunities to interact with dolphins.
They vie for attention
with other equally endearing marine animals such as the beluga whale.
Calves are born grey, fading to white as they mature.
Adults are easily distinguishable by their rounded foreheads
and lack of dorsal fin.
And they clearly enjoy an appreciative audience.
NARRATOR: The Great Barrier Reef is a massive community of animals.
It comprises over 3,000 individual reef systems.
It runs along
Australia's eastern coast,
from the Tropic of Capricorn,
north towards the equator.
The incredible variety of life here is hard to take in.
The world's largest collection of corals
frequented by over 1,500 species of fish.
It's difficult to comprehend that a structure so large,
it's even visible from space,
begins with a tiny coral polyp,
a soft-bodied animal related to jellyfish and sea anemones.
A young polyp begins life drifting in the ocean.
When it lands in a suitable home,
it attaches itself to the sea bed,
somewhere warm and shallow with lots of sunshine.
Then the miraculous process of reef-building begins.
These families of coral polyps
have created a wonder of magical shapes and colours
over many thousands of years.
And of course, they provide a perfect home for the countless creatures
living in the tropical seas.
The toxic stinging cells of the sea anemone
are also an underwater oddity,
for they provide protection for another small creature,
the iconic clownfish.
This little fish would be easy prey
for the larger predators on the reef,
so it's worked out a way to stay safe
by living between the dangerous tentacles of a sea anemone.
So, how does it avoid being stung and eaten
like all the other fish unfortunate enough to swim this way?
The answer is by being very careful.
When a clownfish first arrives at a potential anemone home,
it performs a kind of dance,
gently touching the anemone's tentacles.
This allows the fish to become accustomed to its stings.
Clownfish also develop a thick mucous on their skin,
which aids their protection.
Their ability to live where other fish fear to venture is astounding,
but so too is their ability to change sex.
Clownfish are all born male.
Once a group is established,
the largest will miraculously turn into a female
to ensure reproduction continues.
As the dominant individual in the group,
she becomes capable of laying eggs for the males to fertilise.
If the female dies,
then the largest remaining male will step up and change sex
to take her place.
The Great Barrier Reef really is like an enormous underwater city.
It provides shelter, food, and company
for whole communities of extraordinary animals,
and one essential service that keeps the entire system healthy
is provided at cleaning stations.
These stations are set up by a handful of unusual creatures,
such as the aptly named cleaner shrimp...
..who survive by cleaning and eating dead cells and parasites
from the skin of larger animals.
The local fish know where to go to get their teeth cleaned,
and so do the local divers.
(UPBEAT INSTRUMENTAL MUSIC)
Cleaner shrimp are so confident,
they will even crawl into the gill cavities and mouths of big fish
without any fear of being eaten.
Scientists have recently discovered
how crucial cleaning stations are to the reef.
In sample areas where cleaner fish were removed,
three quarters of the fish population disappeared.
It's assumed that many reef creatures
would quickly succumb to disease and ill health
if they were not regularly cleaned.
So, it's no wonder these are popular places.
The number of visitors at any one cleaning station
could be well over 2,000 per day.
And with up to 1,200 parasites being removed
in a single fish cleaning session,
it's a wonder these tiny shrimp can keep up with the demand.
(STIRRING INSTRUMENTAL MUSIC)
The Great Barrier Reef is perhaps best known
for its profusion of small colourful fish.
Great schools of anthias catch the sun
in shades of peach and gold.
Exotically named individuals
like angelfish, sweetlip, and damselfish
swim gracefully through the branching corals.
The reef also provides a home for strange creatures
like barrel sponges and giant clams.
Many of the islands that rise from the reef
are fringed by idyllic, icing sugarlike beaches...
..created by a creature in the sea, the bumphead parrotfish.
This is the world's largest parrotfish,
and its favourite food is coral.
It uses the massive bump on its head to knock off big chunks of coral,
and its beaklike mouth to crush and consume the spoils.
The fish is actually only interested
in the polyps and algae inside the coral,
but to get that takes a bit of work.
The crushed coral skeleton is then excreted as waste -
waste that washes up onto atolls such as this as sand.
Yes, that deliciously soft powder beneath your toes
is mostly made from parrotfish poo.
(STIRRING INSTRUMENTAL MUSIC)
Studies in the Maldives have shown that 85% of the sand there
has come from the rear end of parrotfish.
(JAUNTY INSTRUMENTAL MUSIC)
One type of fish that's well designed
for living in inaccessible places on the reef is the moray eel.
(JAUNTY MUSIC CONTINUES)
These impressive fish can grow to three metres long
and be as thick as a human waist.
Despite these intimidating dimensions,
moray eels are not aggressive to humans.
Divers can come across morays
in tropical and temperate waters around the globe,
but northern Australia has 15 different species
of this spectacular eel.
It takes about 20 years for these eels to reach their full size.
As this time approaches, many of them turn into females.
Within a month of mating, however, they will lay their eggs and die.
One remarkable species of eel
was only discovered when scuba diving became popular.
These eels live out on the open sand,
so they've developed a unique method of remaining inconspicuous
despite their obvious exposure.
They simply pretend they're a field of seagrass.
Spotted garden eels live in huge colonies
on sunlit patches of the sea floor.
Their range extends across the Indian Ocean to Africa,
and up the Western Pacific to Japan.
To feed, they rise out of their burrows
and sway in the ocean currents,
taking in zooplankton as they go.
If alarmed, the eels instantly retreat into the seabed,
and the sand appears as if no-one was ever there.
(JAUNTY INSTRUMENTAL MUSIC)
NARRATOR: The world's oceans are home to seven marine turtle species.
One of the largest, the loggerhead,
can tolerate the colder oceans of northern Europe
and the South Atlantic.
They can be found anywhere
except the extreme conditions of the North and South Pole.
They prefer coastal areas,
but are often spotted travelling way out to sea.
Hawksbill turtles avoid deep waters,
and are usually found in the warm seas near coral reefs,
where their favourite food, sponges, grows in large numbers.
Their dramatic serrated shell and birdlike beak
makes them easy to identify.
The gentle green turtle is the most prolific and widespread.
They live in and around the tropics, including Hawaii.
Green turtles are not alarmed by divers,
so it's often possible to swim right up to them
to get a really close encounter.
(GENTLE PIANO MUSIC)
All marine turtles begin life in an egg buried in the sand.
Their mothers make the laborious journey up the beach to dig a nest.
Once she begins laying, she enters a trancelike state,
where nothing, not even onlookers, will disrupt the job at hand.
100 to 200 eggs later, depending on the species,
mum covers the pit completely, then returns back to the sea.
In the course of a season,
a female green turtle may do this five or six times.
Set and forget, and if all goes according to plan...
..six to eight weeks later,
newly hatched turtles will begin to emerge.
(GENTLE PIANO MUSIC)
(HAUNTING INSTRUMENTAL MUSIC)
As they make their way to the ocean, they run a veritable gauntlet,
hoping to avoid predation by crabs hiding below the sand
and birds wheeling overhead.
Once they enter the water, it's game on,
for hordes of hungry fish and ravenous sharks
are patrolling the shallows.
The odds of surviving are stacked against the hatchlings.
Fewer than one in 1,000 survive,
but if this little turtle can make it through the breakers
and out to the open sea,
its chances of surviving to adulthood are good.
(GENTLE INSTRUMENTAL MUSIC)
The years between hatching and reaching maturity
are known as the lost years,
for scientists are still trying to work out where they go.
One thing's for certain, however.
They have an inbuilt natural GPS
that will guide them back to the same area where they were born
when they are ready to breed themselves.
Turtle populations around the world
have taken a hammering over the years.
They're regularly killed in discarded nets
that drift silently through the sea...
..or starve to death after mistaking plastic shopping bags for jellyfish.
Adding to their 21st-century woes, climate change.
For the time being, however, turtles are still with us,
and encountering these ancient mariners in the ocean
remains an inspirational, uplifting experience.
(MYSTICAL INSTRUMENTAL MUSIC)
The island of Eil Malk,
in the Pacific nation of Palau,
is both beautiful and remote...
..and it affords one of the most ethereal animal encounters on Earth.
The lifeforms that have developed here are truly mesmerising.
Golden jellyfish.
The reason people can safely swim here
is that the jellyfish are not able to sting.
Although the lake is saline,
these jellyfish have been cut off from the sea for over 10,000 years.
No open sea means no predators,
and no predators means no need for defences.
These jellyfish have well and truly let their guard down,
and have gradually lost their ability to sting.
The lake was formed when global sea levels rose
after the last ice age.
It's still connected to the neighbouring lagoon by three tunnels,
so water washes in here with every high tide.
Around eight million jellyfish live here when conditions are optimal.
At last count, there were only about 600,000,
but that's still a heck of a lot of jellyfish to contend with.
No-one knows exactly why,
but rainfall here is the lowest it's been in 65 years.
As a result, the lake's salinity levels are the highest on record.
It's too early for scientists to tell
whether the reduced jellyfish numbers
are a natural fluctuation or a result of climate change.
The last population crash was in the 1990s
after an El Nino event...
..and the good news is the jellyfish bounced back.
Everyone here in Palau is hopeful the same thing will happen again.
Of all the animal encounters possible in the marine environment,
this one never fails to delight,
causing many to spontaneously laugh out loud underwater.
(GENTLE TINKLING MUSIC)
Australian sealions may be one of the rarest species in the ocean,
but these adolescent pups don't seem too concerned at all.
They just want to play.
These sublime animals
live just off a remote beach
on the Great Australian Bight
called Baird Bay.
The water can be cold, but if you're prepared to brave it,
the welcome you'll receive is very warm indeed.
There are only three rules to enjoying an encounter
without upsetting the balance of nature.
No sunscreen, no touching, and no chasing.
Sealions differ from seals in two big ways.
They have external ear flaps,
and they can walk on their back flippers,
using their front ones to prop them upright.
There are only about 12,000 Australian sealions
left in the world,
but the local population here at Baird Bay is thriving.
Since legislation has ensured their protection,
numbers have increased threefold.
Another spot in the southern oceans famous for its marine mammals
lies on the other side of the Tasman Sea in New Zealand.
Its standout feature,
apart from the sheer beauty of the place above the waterline,
is a gaping canyon just offshore,
and it's a daunting 3km deep.
Kaikoura is a former whaling station
north of Christchurch
on the South Island of New Zealand.
The name means "crayfish food" in the local Maori language,
and that provides a clue to the unusual abundance
of sea life found here.
The immense underwater canyon below these waves
is rich with krill and other plankton.
This, in turn, draws other sea animals
all the way up the food chain.
Some of the noisiest come here to breed.
Fur seals.
One male commands a harem of about 40 females,
and he'll make a serious song and dance about keeping them for himself.
It's a hard life for a female fur seal.
They give birth, and almost immediately fall pregnant again,
and year after year, they return to Kaikoura to repeat the cycle.
Of equal interest to animal lovers is the sperm whale.
The animal with the largest brain of any creature known to have lived.
Its tail fluke is over four metres across,
driving these enormous animals along at nearly 40km per hour.
This is one of the few places in the world
where sperm whales can be seen so close to shore.
NARRATOR: If size really matters when it comes to animal encounters,
then you really can't overlook the blue whale,
the largest animal in the ocean.
In fact, it's the largest animal that has ever lived.
There are two world-renowned places for seeing them.
One is the Monterey Canyon,
off the coast of California, in the USA,
the other is the east coast of Australia.
Between May and November,
these iconic animals migrate along the coastline.
They're travelling from the rich food sources in the Antarctic
to warmer waters for breeding.
To see one in the wild is an unforgettable experience,
even from the air.
Fully grown blue whales are roughly 30 metres long.
Their heart alone is as big as a car,
and yet they feed exclusively on krill,
tiny shrimplike organisms that have a colossal significance in the sea,
forming the basis for many marine food webs.
Apart from being the biggest animals on the planet,
blue whales are also one of the loudest.
They communicate using low groans, grunts, and pulsing sounds...
..and they can hear each other from 1,600km away.
Humpback whales are a far easier species to encounter in the wild
in glorious places such as this.
The Inside Passage is a well known coastal route
that weaves its way through the islands
on the Pacific Coast of North America.
Humpbacks will outperform
just about any other whale species in the ocean...
..and are regularly seen waving their fins
as if to attract attention,
or breaching clean out of the sea.
They are a migratory species, and travel further than most,
feeding in Antarctica in the summer months
before heading to warmer climes to breed.
They are thought to live up to 50 years,
and the age of a whale can be measured in much the same way
foresters are able to age trees.
When scientists discover a dead whale,
they remove the waxy plugs from its ears
and simply count the number of rings.
(GENTLE INSTRUMENTAL MUSIC)
The Kingdom of Tonga, a collection of 170 islands
lying right in the middle
of the vast Pacific Ocean,
offers an even closer
encounter with whales.
Hundreds of humpbacks choose to come here every year
to raise their young.
From July through to November,
the humpback females stay here to give birth
and nurture their calves.
The females fast while they are nursing young,
who greedily consume up to 600 litres of thick rich milk a day...
..and they don't seem to be bothered by humans dropping in for a visit.
It's a truly magical marine experience.
Mothers and their young swim close together,
often touching each other with their flippers
as a sign of affection.
It will take ten years for these calves to be fully grown,
and they will stay close to their mothers for much of this time.
(SWEEPING ORCHESTRAL MUSIC)
It is clear we humans pose less of a threat to animals underwater
than we do above it.
We swim slowly,
and of course, we can't stay forever in their ocean realm.
We would appear to be a curiosity,
rather than a threat to marine animals,
so they often allow us to get much closer to them
than land animals do...
..and that, in essence, is what makes marine encounters
some of the most spectacular wildlife experiences of all.
Captioned by Ai-Media ai-media.tv