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The Great Barrier Reef.
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It's home to an extraordinarily diverse community
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of animals and plants.
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'Here, unknown species are still being found
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'and astonishing things discovered about creatures we thought we knew.
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'In this series, our research vessel, the Alucia,
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'will allow us to explore and understand the reef as never before.
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'This marine paradise may be best known
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'for its spectacular coral reefs...
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'..but it also has 300 sand islands.'
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600 continental islands.
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Miles of lush forest.
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And deep ocean channels.
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Each of these habitats attracts a very different set of visitors.
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When I first came here almost 60 years ago,
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we knew very little about these communities.
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But today, new tracking systems are allowing us
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to follow the lives of these creatures in new ways.
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From the ocean's great predators...
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..to a mysterious whale that seeks out human contact.
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I'll discover their surprising reasons for visiting
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and reveal why the reef is so important for their survival.
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Last time, we looked at the rich community of animals
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that lives among the coral,
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but the reef also receives visitors.
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Some travel for thousands of miles in order to get here
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and stay for only a few weeks.
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Others linger on the fringes and come in every day.
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Each has its own particular reason for doing so.
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The Great Barrier Reef consists of 3,000 individual coral reefs.
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It stretches for 1,400 miles along Australia's northeast coast.
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And every year, it attracts over a million migrating animals.
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We're beginning our exploration in the north,
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on the outskirts of this vast wilderness.
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Our research vessel, the Alucia,
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has brought us out here to Osprey Reef.
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90 miles, 150 kilometres out in the Coral Sea
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from the edge of the Great Barrier.
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Isolated though it is, it nonetheless plays a crucial part
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in the lives of many of the inhabitants of the Barrier Reef.
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What makes Osprey so interesting
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is that it lies in the path of the south equatorial current.
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This is a moving highway
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that sweeps a host of different visitors towards the great reef.
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We are here to discover
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why this remote outpost is so important to them.
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To do that, we're going to use a very special piece of technology,
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the Alucia's Triton submarine.
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It's the first submersible of its kind ever to dive in these waters.
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Huh! It does look as though water's gurgling up here,
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but in fact, my feet aren't wet.
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S-O, S-O, this is Nadir. Am I clear to vent? Over.
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'Copy Nadir. So you are clear to vent, clear to vent.
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'Have a good dive, guys.'
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Roger. Venting now.
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There we are!
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'The sub not only gives us stunning 360-degree views,
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'it allows us to dive to depths where no unprotected human has ever been.'
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For this dive, we are only going down to about 35 metres,
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just over 100 feet,
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where much of the wildlife we're hoping to film will be feeding.
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Marine geologists have recently gathered sufficient data
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for us to create an accurate three-dimensional picture
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of Osprey Reef for the very first time.
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It is, in fact, a huge mountain hidden beneath the waves
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and rising steeply from the seafloor 2,400 metres below.
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The top of this vast seamount creates a shallow lagoon
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that supports a flourishing community of corals.
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This wall of rock ahead of me is the flank of Osprey Reef.
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When cold, deep, nutrient-rich currents from the ocean
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come in and strike it, they defect it upwards.
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And that creates an oasis for living creatures of all kinds.
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Many creatures live here throughout the year.
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And the boss of them all is one kind, sharks.
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There's one! Close up.
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Whatever else you say about sharks, they are so beautiful in the water.
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Resident predators mean one thing -
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a plentiful supply of food.
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For creatures travelling vast distances to get to the reef,
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that makes Osprey a very desirable waypoint on their journey.
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Seamounts are stopping-off points for visitors.
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They come from far and wide.
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From tiger sharks to turtles.
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And they come to refuel and also, it seems, recalibrate.
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It appears that this is a signpost
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and a checkpoint on the way to the reef.
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Visitors arrive year round.
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Among them are hammerheads.
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Like all sharks, they have tiny sensors on their nose
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which can pick up signals from the earth's magnetic field.
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And that helps them navigate through the blue infinity of the open ocean.
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There are tiger sharks here, too.
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They come to the reef to feed.
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And they seem to know exactly where they're going.
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The proportion of their brain dedicated to smell
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is the largest of any shark.
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Their two nostrils work independently,
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allowing them to smell in stereo and track prey over huge distances.
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From Osprey, some tiger sharks
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travel to a very specific destination on the reef.
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230 miles north of Osprey lies Raine Island.
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Every summer, the tiger sharks arrive without fail.
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They're here to take advantage of a major event on the reef -
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the arrival of the female green turtles.
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The tiger sharks aren't here to kill, they've come to scavenge on the dead.
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The unlucky turtles who have not survived
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their exhausting immigration.
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This is why the tiger shark has earned the unflattering title...
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..Dustbin of the Sea.
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They prefer the easy life of the scavenger,
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so the majority of green turtles have little to fear from these predators.
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In the summer months, the turtles arrive in thousands.
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They have come from as far as New Guinea, Vanuatu
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and New Caledonia to the east,
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as well as from the Torres Straits and beyond to the west.
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Some have travelled an impressive 1,500 miles
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to reach this particular beach.
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It measures only a few hundred metres across,
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a tiny speck in a vast ocean.
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But Raine Island plays a major role in their lives.
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70% of the Barrier Reef's breeding green turtles come here to lay.
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It's one of the most important nesting sites in the world.
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I first visited Raine for a television series
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called Zoo Quest back in 1957.
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At the time, Raine was little known and rarely visited.
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It was then I met my first green turtle hatchling.
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Back then, we had no idea
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just how extraordinary a story these turtles had to tell.
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We now know that if they survive,
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they'll spend the next 40 years of their lives at sea.
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Only then do they return to Raine to breed.
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And astonishingly, they return to exactly the same beach
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where they themselves hatched.
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How they find their way back after decades at sea
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is one of the mysteries that surround this species.
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But new research is suggesting that, just like the sharks,
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they navigate using the earth's magnetic field.
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They weigh up to 130 kilos,
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so hauling themselves up the beach is a gruelling task.
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But it's expected that 30,000 of them
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will come ashore to lay their eggs this year.
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With space in short supply, it's every female for herself.
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Once they've dug a hole, laying can begin.
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Each egg is roughly the size of a Ping-Pong ball.
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A female may lay up to 120 of them at a time
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and she's able to do this six times in a single breeding season.
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Once the eggs are laid, she buries them.
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For the next 60 days, the sand will conceal them from predators
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and protect them from the blistering sun.
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Keeping a very close eye on the turtles' progress
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is Dr Andy Dunstan of the Great Barrier Reef Marine Park Authority.
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Raine Island is the biggest green turtle rookery in the world.
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So it's incredibly important
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with the state of green turtles at the moment.
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Because of this, Raine is the most protected island on the reef.
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Only a handful of biologists are allowed to land here
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and Andy and his team have done so for very good reason.
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A huge number of turtles are certainly coming ashore
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to lay their eggs on the island,
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but the team's observations have revealed a worrying trend.
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The number of young hatchlings surviving incubation in the sand
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has dropped to just 20%.
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It's a serious cause for concern.
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The hatchlings we're seeing coming out
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are nowhere near the numbers that they should be.
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The nests, when we dig them up,
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have got really low levels of successful eggs hatching.
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And that is happening because of the very substance
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that makes this island so suitable for nest-building in the first place.
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Raine Island's a sand island. They move.
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But specifically for the green turtles here,
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the nesting area has become lower, so what we're seeing now
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that we never saw 30 years ago is inundation of tidal waters.
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This means that at high tide, the island is being flooded from below
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and the developing turtle eggs are being drowned.
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75% of the beach-nesting area is not suitable.
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Because turtles take a long time to mature,
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we expect to see a crash in those adult turtle numbers in the future.
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If we do something about hatchling success and nesting success now,
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we should see that recover again.
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Last year, Andy and his team made an ambitious plan.
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In a trial sector, they have raised the turtles nesting area
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by one and a half metres.
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They hope this will keep the developing eggs
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clear of the tidal waters and out of harm's way.
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Two long months after the egg laying began,
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the team returns to see if their plan is working.
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Under the cover of darkness,
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the first of the evening's hatchlings start to emerge.
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They started to push their way up
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through the sand about two days earlier.
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Now comes the moment that Andy and his team have been waiting for.
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A shallow trench helps to delay the new arrivals temporarily
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and allow the team to count them.
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So far, the signs are very encouraging.
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And as the night wears on, it gets better and better.
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This is looking great. We're getting much better nesting success,
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much better hatching success,
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the turtles are nesting right across the whole area
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and not disturbing each other so much.
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And those clutches which are underneath the sand
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are hatching much more successfully.
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It's confirmation that Andy and his team have found the right way
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to restore this vital breeding area.
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But for the young hatchlings, the trials of life have only just begun.
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Each new arrival will have to make a perilous dash to reach the ocean.
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Now they're on their own.
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Andy and his team must not interfere at this stage.
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Inevitably, the tiny, defenceless hatchlings
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attract scores of predators.
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SQUAWKING
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Terns and herons patrol the beach.
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And in the shallows, reef sharks lie in wait.
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Great numbers are lost,
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but enough will make it to the ocean to ensure the species' survival.
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As the young turtles leave the reef,
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they get a helping hand from the ocean currents.
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Swept out into the open ocean and there, they face new hazards.
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If they survive, they will eventually return
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to the very same beaches where they hatched.
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Remote islands like Raine are hugely important
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to both turtles and birds
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that come to the reef to lay their eggs.
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There are 900 isolated islands on the Great Barrier from which to choose
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and there's a habitat to suit every visitor.
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Turtles need sandy beaches
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and many birds need trees.
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'The Alucia is taking us to one of these wooded islands
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'near the southern end of the Great Barrier.'
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Almost 1,000 miles south of Raine is Heron Island.
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And every year, it attracts
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thousands of birds seeking somewhere safe to nest.
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The island is surrounded by fragile coral reef.
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So to reach the shore, I'm leaving the Alucia anchored in deeper water.
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FAINT BIRDSONG
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The warm waters of the Barrier Reef are full of fish.
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Full of food, as far as birds are concerned.
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There are immense numbers of seabirds throughout the year on the reef.
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But the moment comes in the year when, in fact, a bird has to lay.
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And to do that, it has to go onto land.
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And the number of sites where they can build a nest are very limited.
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So they will put up with a great deal of crowding
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and even with intruders, like myself, without deserting their nest.
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Hello.
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'Noddies are very protective parents.
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'Very little deters them from their chick-rearing duties.'
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Over one-and-a-half million birds
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come to the Great Barrier's islands every year to breed.
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To see one of the most intriguing, you'll have to wait until after dark.
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WAILING
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00:22:56,800 --> 00:23:00,640
'The first indication that this secretive character has arrived
252
00:23:00,640 --> 00:23:03,320
'is its rather unusual song.'
253
00:23:03,320 --> 00:23:05,480
WAILING
254
00:23:10,840 --> 00:23:13,600
The old sailors used to call it the ghost bird
255
00:23:13,600 --> 00:23:16,360
because of its extraordinary call.
256
00:23:16,360 --> 00:23:19,800
More properly known as the wedge-tailed shearwater.
257
00:23:19,800 --> 00:23:21,880
WAILING
258
00:23:29,160 --> 00:23:34,040
'The birds' haunting calls guide me to their breeding grounds.'
259
00:23:34,040 --> 00:23:36,600
WAILING
260
00:23:51,160 --> 00:23:55,640
These are true seafaring birds. Out at sea when they're feeding,
261
00:23:55,640 --> 00:23:58,640
they are very expert at flying just above the surface,
262
00:23:58,640 --> 00:24:01,840
or indeed swimming on the surface, catching their fish.
263
00:24:01,840 --> 00:24:04,000
But when they come into land, well,
264
00:24:04,000 --> 00:24:06,680
they have to come in in the dark, for a start.
265
00:24:06,680 --> 00:24:09,440
And their landing is sometimes not very expert.
266
00:24:12,680 --> 00:24:14,720
Night-vision cameras probably give us
267
00:24:14,720 --> 00:24:18,360
better pictures of their landing ground than they seem to have.
268
00:24:33,440 --> 00:24:36,520
Their legs with which they paddle over the surface of the sea
269
00:24:36,520 --> 00:24:41,040
are placed far back on their body, and that makes them clumsy walkers.
270
00:24:44,120 --> 00:24:46,040
These birds have travelled
271
00:24:46,040 --> 00:24:48,080
an extraordinary 4,000 miles to get here.
272
00:24:52,360 --> 00:24:54,560
After spending months feeding at sea,
273
00:24:54,560 --> 00:24:56,680
they've had to come to land in order to breed.
274
00:24:59,440 --> 00:25:01,600
Once paired, they're devoted couples
275
00:25:01,600 --> 00:25:04,880
and both male and female share the tasks of parenthood.
276
00:25:09,800 --> 00:25:11,760
Even though there are trees here,
277
00:25:11,760 --> 00:25:15,080
the shearwaters prefer to make their nests underground.
278
00:25:21,000 --> 00:25:24,440
At the bottom of the nest hole, their three-week-old chick
279
00:25:24,440 --> 00:25:27,000
is waiting for its next meal.
280
00:25:30,160 --> 00:25:32,000
TWEETING
281
00:25:35,120 --> 00:25:37,840
Being a shearwater parent is a demanding job.
282
00:25:40,280 --> 00:25:42,880
Their young requires constant feeding.
283
00:25:44,280 --> 00:25:45,960
It consumes so much food
284
00:25:45,960 --> 00:25:49,600
that eventually, it'll outweigh its own parents.
285
00:25:52,560 --> 00:25:57,320
But its demands compel the adults to continually fly out to sea
286
00:25:57,320 --> 00:25:59,400
and come back again with more food.
287
00:26:01,360 --> 00:26:05,200
And their takeoffs are often just as clumsy as their landings.
288
00:26:37,000 --> 00:26:39,160
Fortunately for their nestlings,
289
00:26:39,160 --> 00:26:41,960
there's no shortage of fish in the summer months.
290
00:26:43,760 --> 00:26:47,360
And scientists have only just discovered why that is.
291
00:26:54,240 --> 00:26:57,560
In the waters just beyond Heron Island,
292
00:26:57,560 --> 00:27:01,920
there's a rich, swirling current known as the Capricorn Eddy.
293
00:27:06,360 --> 00:27:10,760
As it spins clockwise, it pulls up cool waters from below,
294
00:27:10,760 --> 00:27:15,600
which bring rich nutrients to the surface.
295
00:27:15,600 --> 00:27:21,040
That fuels the growth of huge blooms of tiny marine creatures, plankton,
296
00:27:21,040 --> 00:27:23,960
the foundation of the entire marine food web.
297
00:27:25,840 --> 00:27:29,840
So this part of the reef is particularly rich with fish.
298
00:27:29,840 --> 00:27:32,560
Vital food for the hungry young.
299
00:27:37,320 --> 00:27:40,280
By choosing Heron Island as a nesting ground,
300
00:27:40,280 --> 00:27:44,040
the birds can give their nestlings the best possible start in life.
301
00:27:49,760 --> 00:27:52,440
When I first came to the Barrier Reef,
302
00:27:52,440 --> 00:27:55,400
we knew very little about these seasonal visitors.
303
00:27:57,000 --> 00:27:59,920
We could only speculate as to why they came here
304
00:27:59,920 --> 00:28:02,080
and where they came from.
305
00:28:04,640 --> 00:28:08,320
Today, new research is enabling us to understand more clearly
306
00:28:08,320 --> 00:28:13,800
why, every year, particular species come to specific locations to breed.
307
00:28:15,920 --> 00:28:17,800
But there are still large animals
308
00:28:17,800 --> 00:28:21,880
whose movements remain something of a mystery.
309
00:28:21,880 --> 00:28:25,240
Manta rays are the nomads of the reef.
310
00:28:25,240 --> 00:28:27,520
They're huge creatures.
311
00:28:27,520 --> 00:28:31,120
They can measure 15 feet, five metres across
312
00:28:31,120 --> 00:28:34,680
and weigh almost one-and-a-half tonnes.
313
00:28:34,680 --> 00:28:37,720
They come to the reef to feed on plankton,
314
00:28:37,720 --> 00:28:40,320
but they also use it as a sanctuary,
315
00:28:40,320 --> 00:28:43,440
where they can breed, or get a good clean.
316
00:28:47,160 --> 00:28:51,440
Many make their way to the waters that surround Lady Elliot Island
317
00:28:51,440 --> 00:28:53,840
on the southern end of the Great Barrier.
318
00:28:58,160 --> 00:29:01,680
For the visiting manta rays, this is a paradise.
319
00:29:01,680 --> 00:29:05,120
A place where these ocean giants can get a little pampering.
320
00:29:13,120 --> 00:29:16,080
These are the beauty salons of the reef.
321
00:29:16,080 --> 00:29:19,040
And they're often run by a pair of wrasse,
322
00:29:19,040 --> 00:29:22,160
small fish with a stripe running from head to tail.
323
00:29:27,680 --> 00:29:29,160
These committed cleaners
324
00:29:29,160 --> 00:29:31,960
regularly tend to a host of different creatures.
325
00:29:36,440 --> 00:29:38,280
They provide a vital service,
326
00:29:38,280 --> 00:29:42,120
removing the dead skin and parasites from outside
327
00:29:42,120 --> 00:29:45,280
and even inside their clients' bodies.
328
00:29:48,760 --> 00:29:50,880
It may seem like a thankless task,
329
00:29:50,880 --> 00:29:53,920
but the cleaner fish are getting a good meal out of it.
330
00:29:58,320 --> 00:30:02,160
And of all their clients, the manta rays are their star customers.
331
00:30:09,000 --> 00:30:12,040
When business is brisk, they patiently wait in line.
332
00:30:18,920 --> 00:30:20,680
Like planes in a holding pattern,
333
00:30:20,680 --> 00:30:23,640
they circle until an opportunity arrives.
334
00:30:32,840 --> 00:30:36,960
When it's their turn, the manta rays surrender themselves completely.
335
00:30:40,000 --> 00:30:43,080
Within seconds, a host of fish rush to their side.
336
00:30:44,480 --> 00:30:47,800
Manta rays are rarely left waiting for long.
337
00:30:56,240 --> 00:31:00,480
Each fish tends to a very specific part of the manta's body.
338
00:31:01,840 --> 00:31:04,480
And the cleaning can last a full hour.
339
00:31:09,760 --> 00:31:12,880
For the most part, the service is second to none.
340
00:31:12,880 --> 00:31:16,440
But occasionally, the cleaners can get a little carried away.
341
00:31:22,720 --> 00:31:26,600
A female wrasse has taken a nibble out of the manta ray's flesh.
342
00:31:27,720 --> 00:31:31,680
She's broken the rules, and there's a price pay.
343
00:31:31,680 --> 00:31:34,440
Her partner chases after her.
344
00:31:34,440 --> 00:31:37,680
It's the cleaner fish equivalent of a stern telling off.
345
00:31:40,560 --> 00:31:44,440
Scientists believe males do this to protect future business.
346
00:31:46,640 --> 00:31:50,480
If the bite is a one-off, the manta ray will return.
347
00:31:50,480 --> 00:31:53,680
But research has shown that if it happens too often,
348
00:31:53,680 --> 00:31:57,160
the pair risks driving regular visitors away.
349
00:32:02,120 --> 00:32:04,400
Fortunately, it seems her indiscretion
350
00:32:04,400 --> 00:32:06,560
hasn't put their client off.
351
00:32:06,560 --> 00:32:10,440
The manta is back and business has resumed.
352
00:32:14,400 --> 00:32:17,040
Manta rays come here in such numbers
353
00:32:17,040 --> 00:32:21,280
that the island has become the focal point for a research project.
354
00:32:27,120 --> 00:32:30,600
Dr Kathy Townsend has been tracking the manta's movements
355
00:32:30,600 --> 00:32:32,960
and numbers for the last seven years.
356
00:32:43,560 --> 00:32:46,440
Lady Elliot Island is like the centre of the universe
357
00:32:46,440 --> 00:32:49,720
for manta rays on the east coast of Australia.
358
00:32:49,720 --> 00:32:51,480
We come back time and time again
359
00:32:51,480 --> 00:32:54,720
because we get large aggregations of these animals.
360
00:32:55,880 --> 00:32:58,200
We are doing several things with the manta rays.
361
00:32:58,200 --> 00:33:00,160
First of all, we're trying to understand
362
00:33:00,160 --> 00:33:02,000
how many there are potentially here.
363
00:33:02,000 --> 00:33:04,800
And to do that, you need to do some sort of tagging.
364
00:33:07,040 --> 00:33:11,520
This is a key part of Kathy's work in tracking these gentle ocean giants.
365
00:33:11,520 --> 00:33:14,880
And the team has already attached acoustic tags
366
00:33:14,880 --> 00:33:18,200
to a large number of study animals.
367
00:33:18,200 --> 00:33:22,560
We have six acoustic listening stations around Lady Elliot Island.
368
00:33:22,560 --> 00:33:24,320
And as an animal goes past,
369
00:33:24,320 --> 00:33:27,880
within a 500-metre radius of this listening station,
370
00:33:27,880 --> 00:33:31,240
it picks up the tag and we know that that animal's been past.
371
00:33:34,720 --> 00:33:37,920
That has revealed that many of the mantas have travelled
372
00:33:37,920 --> 00:33:41,560
hundreds of miles up the eastern coast of Australia to get here.
373
00:33:45,200 --> 00:33:47,760
One of the lovely things about working with manta rays
374
00:33:47,760 --> 00:33:49,440
is that they're extremely curious
375
00:33:49,440 --> 00:33:52,680
and they'll seek you out to come and see what you're up to.
376
00:34:07,200 --> 00:34:09,200
It's really unusual behaviour.
377
00:34:09,200 --> 00:34:11,120
Most sharks and rays have no interest
378
00:34:11,120 --> 00:34:13,960
in having any interaction with people whatsoever.
379
00:34:13,960 --> 00:34:17,840
But for whatever reason, manta rays are highly-curious creatures
380
00:34:17,840 --> 00:34:20,160
and will basically look at you eye to eye.
381
00:34:22,520 --> 00:34:26,920
The manta ray's inquisitive nature works to Kathy's advantage.
382
00:34:26,920 --> 00:34:31,280
It means she can get close enough to photograph them for identification.
383
00:34:32,920 --> 00:34:37,000
And one of the best places to do that is at the cleaning stations.
384
00:34:49,480 --> 00:34:51,560
We need to get in underneath the animal
385
00:34:51,560 --> 00:34:54,080
and take a photograph from below.
386
00:34:54,080 --> 00:34:58,000
Each individual has a very unique spot pattern
387
00:34:58,000 --> 00:35:01,920
that stays with them from birth until they pass away.
388
00:35:01,920 --> 00:35:03,520
That's very handy for us.
389
00:35:08,760 --> 00:35:11,440
When Project Manta began seven years ago,
390
00:35:11,440 --> 00:35:15,960
it was thought that fewer than 40 individuals came to Lady Elliot.
391
00:35:15,960 --> 00:35:20,160
Today, Kathy and her team have catalogued more than 800.
392
00:35:23,560 --> 00:35:26,120
I think manta ray research is quite important
393
00:35:26,120 --> 00:35:29,000
because first of all, this is a very large-bodied animal
394
00:35:29,000 --> 00:35:32,360
that very little information is known about.
395
00:35:32,360 --> 00:35:34,080
Various places around the world,
396
00:35:34,080 --> 00:35:37,040
the manta ray populations have declined dramatically,
397
00:35:37,040 --> 00:35:40,760
to the point where they've now been listed as threatened
398
00:35:40,760 --> 00:35:42,880
on that list for endangered species.
399
00:35:45,280 --> 00:35:49,440
For the visiting mantas, the Great Barrier Reef really is a sanctuary.
400
00:35:51,360 --> 00:35:54,200
Here, this ocean giant is properly protected.
401
00:35:56,080 --> 00:35:57,560
While they're in these waters,
402
00:35:57,560 --> 00:36:01,200
they're safe from the fisheries that threaten them elsewhere.
403
00:36:05,000 --> 00:36:08,280
Manta rays aren't the only animals that find refuge here.
404
00:36:09,800 --> 00:36:13,520
The Great Barrier protects its visitors in many different ways.
405
00:36:20,120 --> 00:36:24,520
'That becomes clear when you look at the reef from above.
406
00:36:27,840 --> 00:36:29,800
'This part of tropical Australia
407
00:36:29,800 --> 00:36:33,440
'lies right in the path of regular seasonal cyclones.
408
00:36:33,440 --> 00:36:36,840
'And from up here, you can see what valuable protection
409
00:36:36,840 --> 00:36:38,560
'the reef can provide.'
410
00:36:40,880 --> 00:36:42,920
This tangle of limestone walls
411
00:36:42,920 --> 00:36:47,000
acts as a barrier against the open ocean.
412
00:36:47,000 --> 00:36:51,480
Between it and the land, the waters are warm and shallow.
413
00:36:51,480 --> 00:36:54,400
An ideal haven for visitors.
414
00:36:56,360 --> 00:36:59,280
In the winter, many creatures come up here to escape
415
00:36:59,280 --> 00:37:01,880
the freezing temperatures of the Antarctic.
416
00:37:09,320 --> 00:37:12,600
Among them are humpback whales.
417
00:37:32,880 --> 00:37:34,320
WHALE SONG
418
00:37:34,320 --> 00:37:36,000
Weighing up to 40 tonnes,
419
00:37:36,000 --> 00:37:39,160
they're the largest of the Great Barrier Reef's visitors
420
00:37:39,160 --> 00:37:42,440
and they have also travelled great distances to get here.
421
00:37:52,440 --> 00:37:57,040
Each year, they make an exhausting 6,000-mile-round trip
422
00:37:57,040 --> 00:37:59,400
from the Antarctic and back again.
423
00:38:04,280 --> 00:38:06,720
Incredibly, 20,000 of them do it.
424
00:38:13,440 --> 00:38:15,840
Here, in these warm and sheltered waters,
425
00:38:15,840 --> 00:38:18,640
they give birth and suckle their newborn calves.
426
00:38:23,720 --> 00:38:26,160
But in fact, we still know very little
427
00:38:26,160 --> 00:38:28,560
about what else they do once they get here.
428
00:38:33,320 --> 00:38:36,400
Where exactly do they go during their time on the reef?
429
00:38:40,560 --> 00:38:42,040
The fact that we don't know
430
00:38:42,040 --> 00:38:45,680
is a reminder of just how vast this great wilderness is.
431
00:38:49,040 --> 00:38:52,280
But not all whales make the task of tracking them so hard.
432
00:38:55,200 --> 00:38:58,480
In fact, there's one species which does quite the opposite.
433
00:38:58,480 --> 00:39:02,400
Incredibly, this whale actively seeks out the scientists
434
00:39:02,400 --> 00:39:04,560
who are trying to study them.
435
00:39:15,240 --> 00:39:19,920
This endearing little character is the dwarf minke whale.
436
00:39:22,640 --> 00:39:25,120
And surprisingly, it was only first observed
437
00:39:25,120 --> 00:39:27,400
here on the reef in the 1980s.
438
00:39:30,720 --> 00:39:35,000
But since then, we've realised that they're extremely faithful visitors,
439
00:39:35,000 --> 00:39:38,800
returning every year to the same location on the northern reef.
440
00:39:47,240 --> 00:39:50,080
Why they do so, we still don't understand.
441
00:39:52,640 --> 00:39:55,440
But research is beginning to reveal their story.
442
00:39:57,960 --> 00:40:00,760
Dr Alistair Birtles knows more about
443
00:40:00,760 --> 00:40:04,440
this still-mysterious species than anyone else.
444
00:40:04,440 --> 00:40:07,960
So he's affectionately known as Professor Minke.
445
00:40:10,600 --> 00:40:15,080
To observe the whales in detail, he has to step into their world.
446
00:40:17,280 --> 00:40:20,160
The very first time I got in the water, um...
447
00:40:20,160 --> 00:40:26,320
was with a degree of apprehension, great excitement.
448
00:40:26,320 --> 00:40:30,440
Um...I don't think I'd ever been in the water with a whale before.
449
00:40:30,440 --> 00:40:34,840
And the first thing you see is the white shoulder, um...
450
00:40:34,840 --> 00:40:38,840
and then the rest of the grey animal emerges around it.
451
00:40:38,840 --> 00:40:42,200
It's very special being in the water
452
00:40:42,200 --> 00:40:45,080
with these animals in their own environment.
453
00:40:45,080 --> 00:40:48,000
It's an extraordinary experience.
454
00:40:51,280 --> 00:40:54,080
Every year, Alistair and his research team
455
00:40:54,080 --> 00:40:56,840
return to spend time with the dwarf minkes.
456
00:40:59,360 --> 00:41:03,400
These annual reunions are beginning to reveal more and more
457
00:41:03,400 --> 00:41:05,520
about these fascinating creatures.
458
00:41:08,000 --> 00:41:12,160
It seems that they spend most of their lives out in the open ocean,
459
00:41:12,160 --> 00:41:15,120
leading what's thought to be a solitary existence.
460
00:41:18,000 --> 00:41:21,600
But surprisingly, when they get here, on the Great Reef,
461
00:41:21,600 --> 00:41:23,800
they actively seek human contact.
462
00:41:28,000 --> 00:41:30,480
Behaviour like this happens nowhere else.
463
00:41:32,360 --> 00:41:35,640
It is entirely the world's curiosity that brings them in.
464
00:41:35,640 --> 00:41:38,760
I think we're a rather strange object.
465
00:41:38,760 --> 00:41:41,520
We're a visitor into their world.
466
00:41:41,520 --> 00:41:45,200
I'm sure they're wondering exactly what we are
467
00:41:45,200 --> 00:41:48,960
and what we're doing, just as we're wondering what they're doing.
468
00:41:51,480 --> 00:41:54,760
For Birtles, there are many familiar faces here.
469
00:41:54,760 --> 00:41:57,840
And he has his own pet names for regular visitors.
470
00:42:00,040 --> 00:42:04,360
Bento, I have seen every year for the last eight years.
471
00:42:05,720 --> 00:42:07,520
She has a bent-over dorsal fin
472
00:42:07,520 --> 00:42:12,200
from I think where she was fairly savagely mauled by a shark.
473
00:42:12,200 --> 00:42:15,440
And last year's encounter was a particularly special one
474
00:42:15,440 --> 00:42:17,640
because she had a calf with her.
475
00:42:17,640 --> 00:42:21,640
That's the first time in eight years that we've known she had a calf.
476
00:42:21,640 --> 00:42:25,920
And it was a little male and it was a very special interaction.
477
00:42:34,640 --> 00:42:37,320
What Birtles and his team want to discover
478
00:42:37,320 --> 00:42:39,720
is why this usually-solitary whale
479
00:42:39,720 --> 00:42:43,320
suddenly becomes so extremely social when it gets here.
480
00:42:45,040 --> 00:42:47,240
There are a number of clues.
481
00:42:47,240 --> 00:42:51,080
We know they're not feeding. We've never seen them feed.
482
00:42:51,080 --> 00:42:53,680
But we see a lot of socialising going on.
483
00:42:55,040 --> 00:42:58,560
Minkes were known as the silent whale when we began working on them
484
00:42:58,560 --> 00:43:01,160
and there were no recordings of dwarf minkes.
485
00:43:02,800 --> 00:43:06,760
It went on for quite a while before we heard any sounds.
486
00:43:13,480 --> 00:43:15,800
And then there's an extraordinary sound they make
487
00:43:15,800 --> 00:43:19,040
which the researcher who labelled it
488
00:43:19,040 --> 00:43:22,120
called it the Star Wars sound.
489
00:43:22,120 --> 00:43:25,320
I thought it was a little more like Beethoven's Fifth
490
00:43:25,320 --> 00:43:29,640
because it's got a triple beat and then a long shwang
491
00:43:29,640 --> 00:43:31,600
that he thought was the lightsaber.
492
00:43:31,600 --> 00:43:34,080
So it goes, da-da-da-dang.
493
00:43:35,200 --> 00:43:37,120
WHALE SONG
494
00:43:38,400 --> 00:43:39,640
WHALE SONG
495
00:43:39,640 --> 00:43:43,760
When you hear it underwater, it kind of reverberates through your chest.
496
00:43:43,760 --> 00:43:45,840
It's a very powerful sound.
497
00:43:45,840 --> 00:43:47,880
WHALE SONG
498
00:43:51,440 --> 00:43:53,960
The song is only produced by males
499
00:43:53,960 --> 00:43:56,880
and it's thought to be related to courtship.
500
00:43:56,880 --> 00:43:58,960
WHALE SONG
501
00:43:58,960 --> 00:44:01,920
Curiously, two thirds of the individuals
502
00:44:01,920 --> 00:44:04,480
Alistair encounters are adolescents.
503
00:44:06,280 --> 00:44:10,680
One theory is that the whales are coming here to find potential mates
504
00:44:10,680 --> 00:44:14,240
and learn the dos and don'ts of minke social behaviour.
505
00:44:16,360 --> 00:44:18,240
Though Birtles' team has amassed
506
00:44:18,240 --> 00:44:20,440
a huge amount of data over the decades,
507
00:44:20,440 --> 00:44:23,520
there is clearly still much to learn.
508
00:44:24,920 --> 00:44:29,680
Where, for example, do the whales go after this social gathering?
509
00:44:32,760 --> 00:44:35,280
But now, a brand-new tagging programme
510
00:44:35,280 --> 00:44:38,040
is shedding more light on their annual journey.
511
00:44:41,720 --> 00:44:44,440
Tagging is not easy.
512
00:44:47,720 --> 00:44:49,720
The diver has to get into position,
513
00:44:49,720 --> 00:44:52,800
choose his mark and then discharge the tag,
514
00:44:52,800 --> 00:44:54,960
all on a single breath.
515
00:44:57,880 --> 00:45:00,040
There's no room for error.
516
00:45:22,000 --> 00:45:23,600
After initially taking fright,
517
00:45:23,600 --> 00:45:26,800
the whale comes back to the dive boat.
518
00:45:26,800 --> 00:45:30,160
It seems that minkes aren't too distressed by the process.
519
00:45:34,360 --> 00:45:37,000
The tracking data the team is now collecting
520
00:45:37,000 --> 00:45:41,080
may reveal the piece of the puzzle that, until now, has been missing.
521
00:45:41,080 --> 00:45:44,720
So for 20 years, we've been studying what the whales do
522
00:45:44,720 --> 00:45:47,200
in this area of the Great Barrier Reef.
523
00:45:47,200 --> 00:45:50,000
We know they're only here for a few weeks
524
00:45:50,000 --> 00:45:52,000
and we had no idea where they went
525
00:45:52,000 --> 00:45:54,320
when they left the Great Barrier Reef
526
00:45:54,320 --> 00:45:56,360
at the end of their sojourn here.
527
00:45:58,440 --> 00:46:00,440
It really is an extraordinary journey
528
00:46:00,440 --> 00:46:02,640
that we now know that they make.
529
00:46:02,640 --> 00:46:06,200
Spot, the young male that was the first ever minke
530
00:46:06,200 --> 00:46:10,760
to have a satellite tag attached in 2013,
531
00:46:10,760 --> 00:46:16,560
he travelled over 7,000 kilometres deep into the Subantarctic.
532
00:46:16,560 --> 00:46:22,080
That's an extraordinary journey for what is a little whale, to make.
533
00:46:22,080 --> 00:46:26,040
The tagging tells us where the whales are travelling fast
534
00:46:26,040 --> 00:46:28,920
and where they're spending extra time.
535
00:46:28,920 --> 00:46:32,600
There's a few places along the east coast of Australia and Bass Strait
536
00:46:32,600 --> 00:46:36,600
where they may spend one, two or even three weeks of time
537
00:46:36,600 --> 00:46:39,680
milling around, probably feeding.
538
00:46:39,680 --> 00:46:43,520
So we may have discovered some of these feeding sites
539
00:46:43,520 --> 00:46:46,680
for the dwarf minke whale along their migration path.
540
00:46:48,480 --> 00:46:50,120
For Birtles, it's not just about
541
00:46:50,120 --> 00:46:53,080
solving the mystery of where the whales go.
542
00:46:53,080 --> 00:46:56,560
I am worried about them when they leave the reef.
543
00:46:56,560 --> 00:46:58,800
The dwarf minkes are well protected
544
00:46:58,800 --> 00:47:00,760
when they're in the Great Barrier Reef,
545
00:47:00,760 --> 00:47:06,120
but when they leave there, they face many threats and dangers
546
00:47:06,120 --> 00:47:09,840
and they have to cross major shipping channels.
547
00:47:09,840 --> 00:47:13,800
There are all sorts of threats from fishing.
548
00:47:13,800 --> 00:47:18,600
I mean, if commercial whaling is resumed in the Southern Ocean,
549
00:47:18,600 --> 00:47:22,360
which is the objective of the research that's going on
550
00:47:22,360 --> 00:47:26,320
at the moment from the Japanese, then these whales would be at risk.
551
00:47:31,480 --> 00:47:35,000
It's hoped the new tagging programme may help us understand
552
00:47:35,000 --> 00:47:39,240
how best to protect these whales throughout the entire year.
553
00:47:41,960 --> 00:47:46,040
By venturing into their underwater world, Birtles and his team
554
00:47:46,040 --> 00:47:49,280
are discovering valuable new facts about these whales.
555
00:47:50,880 --> 00:47:53,160
But their research has only just begun.
556
00:47:57,400 --> 00:48:01,280
The more we learn about the creatures that come here, the more we discover
557
00:48:01,280 --> 00:48:04,920
just how important the Great Barrier Reef is to their survival.
558
00:48:08,160 --> 00:48:09,840
The reef is immense.
559
00:48:11,320 --> 00:48:15,400
Millions of visitors travel great distances to get to it.
560
00:48:15,400 --> 00:48:19,800
And there, find food, shelter and an opportunity to meet a mate.
561
00:48:23,040 --> 00:48:26,960
A global community of animals rely on this great wilderness.
562
00:48:29,480 --> 00:48:31,840
And that makes it one of the most important
563
00:48:31,840 --> 00:48:34,320
and influential habitats on the planet.
564
00:48:39,000 --> 00:48:42,120
Next time, in our final programme...
565
00:48:43,400 --> 00:48:47,120
..we'll investigate the dangers that now threaten the reef
566
00:48:47,120 --> 00:48:48,640
and its inhabitants.
567
00:48:52,640 --> 00:48:54,480
THUNDERCLAP
568
00:48:54,480 --> 00:48:56,560
We'll meet the extraordinary people
569
00:48:56,560 --> 00:48:58,680
who are doing everything in their power
570
00:48:58,680 --> 00:49:00,960
to protect this marine paradise.
571
00:49:00,960 --> 00:49:05,000
It is one of the most magnificent ecosystems on the planet.
572
00:49:05,000 --> 00:49:07,320
What's really quite shocking is that we may lose it
573
00:49:07,320 --> 00:49:10,080
before we truly understand it.
574
00:49:10,080 --> 00:49:13,480
And we'll attempt our most ambitious dive yet.
575
00:49:13,480 --> 00:49:18,560
Nobody has ever dived as deep as this before on the Great Barrier Reef.
576
00:49:20,640 --> 00:49:25,320
As we search for new species and try to predict what the future holds
577
00:49:25,320 --> 00:49:27,800
for the Great Barrier.
578
00:49:45,840 --> 00:49:48,480
For this episode, one of our underwater teams
579
00:49:48,480 --> 00:49:51,240
travelled to Lady Elliot Island in the south.
580
00:49:55,840 --> 00:49:58,360
Here, the reef's majestic manta rays
581
00:49:58,360 --> 00:50:02,800
are stripped of dead skin and parasites by tiny cleaner fish.
582
00:50:05,280 --> 00:50:08,080
The crew's goal was to film a rare behaviour.
583
00:50:09,600 --> 00:50:12,760
The moment when the cleaner fish breaks the rules
584
00:50:12,760 --> 00:50:15,480
and bites a manta ray's flesh.
585
00:50:17,160 --> 00:50:19,440
To film the story, the team worked closely
586
00:50:19,440 --> 00:50:21,960
with marine biologist, Dr Kathy Townsend.
587
00:50:25,360 --> 00:50:29,640
Manta rays will often seek out and spend time with divers,
588
00:50:29,640 --> 00:50:33,560
which, of course, makes them amazing animals to be in the water with.
589
00:50:34,880 --> 00:50:38,560
Manta rays may be inquisitive, but they can easily be spooked.
590
00:50:38,560 --> 00:50:41,320
The challenge for cameraman, Mike Pitts,
591
00:50:41,320 --> 00:50:44,400
was to make himself as unobtrusive as possible.
592
00:50:46,520 --> 00:50:48,520
You are bulky and clumsy,
593
00:50:48,520 --> 00:50:50,680
you've got large cameras, lights.
594
00:50:50,680 --> 00:50:55,680
So what you don't want to do is to obstruct the manta ray.
595
00:50:55,680 --> 00:50:59,400
The manta ray might get disturbed and it'll just swim off.
596
00:50:59,400 --> 00:51:01,640
I generally keep as low as possible.
597
00:51:01,640 --> 00:51:04,440
So your profile sort of matches in with the reef.
598
00:51:04,440 --> 00:51:06,600
And so what you notice after a while is
599
00:51:06,600 --> 00:51:09,920
the manta rays will come closer and closer and closer to you.
600
00:51:09,920 --> 00:51:14,800
And I can literally... I feel them brushing over my head as they go.
601
00:51:14,800 --> 00:51:17,760
While the team's objective was to film the cleaning station,
602
00:51:17,760 --> 00:51:19,480
on the fourth day of the shoot,
603
00:51:19,480 --> 00:51:22,360
they were treated to something truly unexpected.
604
00:51:25,320 --> 00:51:27,200
We were close to the end of the dive
605
00:51:27,200 --> 00:51:30,040
and we hadn't really seen anything for about 58 minutes
606
00:51:30,040 --> 00:51:32,200
and then I spotted a pair.
607
00:51:35,240 --> 00:51:39,040
I saw Kathy and suddenly she zoomed off and we followed.
608
00:51:39,040 --> 00:51:42,720
And I could see out in the distance, there was a male above a female
609
00:51:42,720 --> 00:51:45,920
and he was following her every move
610
00:51:45,920 --> 00:51:48,120
as she moved through the water.
611
00:51:48,120 --> 00:51:49,880
Kathy got really excited.
612
00:51:52,240 --> 00:51:54,720
They were undergoing behaviour I'd never seen before.
613
00:51:54,720 --> 00:51:56,840
I'd seen various types of courtship behaviour
614
00:51:56,840 --> 00:51:59,000
that involves having trains,
615
00:51:59,000 --> 00:52:02,280
where there's a female at the front followed by several males.
616
00:52:02,280 --> 00:52:06,280
What was happening between these two was really quite unique.
617
00:52:06,280 --> 00:52:09,440
The male was obviously trying to court her,
618
00:52:09,440 --> 00:52:11,960
but in a very unusual way.
619
00:52:11,960 --> 00:52:14,000
He was taking his front cephalic lobes
620
00:52:14,000 --> 00:52:16,560
and he was actually stroking her on her back.
621
00:52:18,640 --> 00:52:20,840
Obviously trying to entice her to say,
622
00:52:20,840 --> 00:52:23,120
"Listen, you know, I'm the one for you".
623
00:52:24,240 --> 00:52:27,080
She, on the other hand, was not quite enthusiastic
624
00:52:27,080 --> 00:52:30,640
about the attention that he was bestowing upon her.
625
00:52:31,680 --> 00:52:34,640
And all of sudden, she'd just fling up into the air to shake him off
626
00:52:34,640 --> 00:52:36,760
and say, "No, it's not ready for that yet".
627
00:52:36,760 --> 00:52:38,840
And then she would settle back down.
628
00:52:47,360 --> 00:52:49,840
I knew it was something very special because,
629
00:52:49,840 --> 00:52:52,920
seeing Kathy's reactions to what was going on,
630
00:52:52,920 --> 00:52:56,280
she was so excited about it, she was bubbling.
631
00:52:58,680 --> 00:53:01,120
You could wait a lifetime to see something like that.
632
00:53:01,120 --> 00:53:02,800
Just a very rare event.
633
00:53:05,400 --> 00:53:08,800
In the far north, another wildlife crew had their sights set
634
00:53:08,800 --> 00:53:12,560
on filming a very special seasonal visitor.
635
00:53:12,560 --> 00:53:16,160
In winter, dwarf minke whales come to the reef
636
00:53:16,160 --> 00:53:18,560
for just a few short weeks.
637
00:53:20,120 --> 00:53:22,160
Wildlife cameraman, Dean Miller,
638
00:53:22,160 --> 00:53:25,240
has been documenting these whales for 15 years.
639
00:53:27,200 --> 00:53:29,600
It's a little bit unnerving sometimes jumping in
640
00:53:29,600 --> 00:53:33,080
and seeing a seven-tonne, seven-metre animal
641
00:53:33,080 --> 00:53:35,040
come out from the gloom.
642
00:53:35,040 --> 00:53:37,760
And you're hoping that it is going to be the whale
643
00:53:37,760 --> 00:53:40,040
and not something with a few more teeth.
644
00:53:41,360 --> 00:53:43,520
Every animal presents a very different challenge
645
00:53:43,520 --> 00:53:45,600
when it comes to filming behaviour,
646
00:53:45,600 --> 00:53:49,360
but over the years, Dean has learned the minke tricks of the trade.
647
00:53:52,040 --> 00:53:54,680
It's sometimes a game of cat and mouse, in a way.
648
00:53:54,680 --> 00:53:57,520
Because if you're not looking, they tend to come a lot closer.
649
00:53:57,520 --> 00:54:00,320
So if I can see a whale approaching in the distance
650
00:54:00,320 --> 00:54:02,960
and I know it's going to be a good approach this time,
651
00:54:02,960 --> 00:54:05,120
I'll purposely hold off and turn my dome around
652
00:54:05,120 --> 00:54:08,240
and actually see in the reflection of the dome the whale coming to me
653
00:54:08,240 --> 00:54:11,400
and then, when I think it's probably about five to six metres away,
654
00:54:11,400 --> 00:54:14,400
I'll turn around and get the best shot I've had all day.
655
00:54:14,400 --> 00:54:16,280
They sneak up on you.
656
00:54:17,760 --> 00:54:19,720
Over time, they build up that confidence
657
00:54:19,720 --> 00:54:23,640
and they just really, really try to edge much closer
658
00:54:23,640 --> 00:54:25,560
each and every time and get a good look.
659
00:54:27,840 --> 00:54:30,840
I do have other tricks, as well. I'll sing through my snorkel.
660
00:54:30,840 --> 00:54:32,680
HUMMING
661
00:54:34,480 --> 00:54:37,160
You can be in the water for seven, eight hours a day
662
00:54:37,160 --> 00:54:39,760
and you might only get two of these passes for that whole day.
663
00:54:39,760 --> 00:54:43,000
And when they happen, they're just mind-blowing.
664
00:54:43,000 --> 00:54:44,800
You've got this big, big animal.
665
00:54:44,800 --> 00:54:47,360
I mean, it's the size of a minibus, coming to look at you.
666
00:54:50,320 --> 00:54:53,440
You can get out at the end of a day and just have the biggest smile.
667
00:54:53,440 --> 00:54:55,720
I've just watched the sunset from in the water.
668
00:54:55,720 --> 00:54:59,600
A whale nearly touched me. It just doesn't get any better.
669
00:55:04,920 --> 00:55:06,640
'While our underwater crews
670
00:55:06,640 --> 00:55:09,320
'were rewarded with spectacular interactions,
671
00:55:09,320 --> 00:55:12,240
'on Heron Island, I had the opportunity
672
00:55:12,240 --> 00:55:14,360
'to meet one of my favourite visitors.'
673
00:55:17,040 --> 00:55:18,520
The noddy.
674
00:55:20,000 --> 00:55:23,880
The birds' relaxed nature and attachment to their nests
675
00:55:23,880 --> 00:55:27,160
meant we could tell their story without disturbing them.
676
00:55:28,200 --> 00:55:30,000
Without deserting their nest.
677
00:55:33,560 --> 00:55:34,920
Hello.
678
00:55:34,920 --> 00:55:37,240
But when cameraman, Mike Pitts returns
679
00:55:37,240 --> 00:55:39,680
to film the hatchlings three months later,
680
00:55:39,680 --> 00:55:42,680
disaster hits the island on his first night.
681
00:55:44,200 --> 00:55:45,920
THUNDERCLAP
682
00:55:50,440 --> 00:55:52,760
WIND GUSTS
683
00:56:00,000 --> 00:56:03,720
The following morning, Mike discovers that the storm has destroyed
684
00:56:03,720 --> 00:56:05,920
the very spot where I had filmed.
685
00:56:08,000 --> 00:56:10,200
It was shattered. It was like a warzone.
686
00:56:10,200 --> 00:56:13,360
You think of these idyllic, tropical islands
687
00:56:13,360 --> 00:56:15,560
and you couldn't be further from the truth.
688
00:56:22,320 --> 00:56:23,880
Are you still rolling?
689
00:56:23,880 --> 00:56:26,400
You can see that many of the trees are down.
690
00:56:26,400 --> 00:56:29,120
And it's brought down the chicks with them and the nests.
691
00:56:29,120 --> 00:56:31,880
Eggs are smashed, chicks are dying.
692
00:56:31,880 --> 00:56:33,960
And the chicks that have survived
693
00:56:33,960 --> 00:56:36,440
are now on these trunks and branches
694
00:56:36,440 --> 00:56:38,280
and on the ground of the forest itself,
695
00:56:38,280 --> 00:56:40,440
hoping for their parent birds
696
00:56:40,440 --> 00:56:42,640
to find them and bring the food they need.
697
00:56:42,640 --> 00:56:44,440
But the parent birds are so confused
698
00:56:44,440 --> 00:56:46,520
because so many of the trees are gone.
699
00:56:46,520 --> 00:56:50,360
It's very disheartening to see it, and, er...it's a real sad sight.
700
00:56:54,200 --> 00:56:57,480
I'd never seen the aftermath of such a strong storm.
701
00:56:58,480 --> 00:57:01,920
But, of course, your emotions always get the better of you.
702
00:57:05,880 --> 00:57:10,040
You still see survivors, just sitting on the nest,
703
00:57:10,040 --> 00:57:12,680
protecting the egg or the chick.
704
00:57:12,680 --> 00:57:15,520
It really is quite amazing, their resilience.
705
00:57:16,920 --> 00:57:20,360
It puts the whole reef into a context whereby
706
00:57:20,360 --> 00:57:23,240
you're following the rhythms of life.
707
00:57:23,240 --> 00:57:26,040
We were there to record it and film it
708
00:57:26,040 --> 00:57:28,320
and that's part of the Great Reef story.
60526
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