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{\an7}700 Requins Dans La Nuit
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Jan NiCholay
Iklan & Bisnis: 0821 9946 8700
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[tense music playing]
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[male narrator] This is the biggest packof gray sharks on Earth.
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Seven hundred of them.
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These awesome predatorsgather under the full moon
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for a single purpose:
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to feed.
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Now, a team of scientists is diving in,
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using state-of-the-art tech
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to capture the epic huntlike never before,
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and find out what really goes oninside this massive shark swarm.
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Seven hundred gray sharks
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live in the middle of the vastPacific Ocean,
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around an island invisible from space,
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about 250 miles from the island of Tahiti,
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the atoll of Fakarava.
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The atoll is a ring of coral
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pierced by breachesthat link the lagoon to the ocean.
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The deepest of theseare called "channels."
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Hidden away in Fakarava'ssouthernmost channel
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is the world's densest populationof gray reef sharks.
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700 of them live right herein this valley of coral,
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classified as a UNESCO biosphere reserve.
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Much of their behavior is a mystery.
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What attracts them herein such huge numbers?
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Are there leaders whom the rest follow?
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[indistinct chatter]
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A team of more than20 divers and scientists
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are here to find out.
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Leading the team is biologistand photographer Laurent Ballesta.
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[indistinct chatter]
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Laurent and his teamhave been here before,
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four years ago, to check out rumorsof vast schools of thousands of groupers
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coming here to reproduceduring the June full moon,
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which acts as a signal to themto start laying their eggs.
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The rumor was true.
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The Fakarava channel is the site
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of one of the largest aggregationsin the world,
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17,000 groupers.
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Inevitably, they drew the sharks.
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There were so many of the predators
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that the team kept countingand recounting them.
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One camera traveled the wholelength of the southern channel,
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about half a mile.
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The footage revealedan astonishing count of 700;
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705 to be precise.
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That's the highest densityanyone's ever seen.
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Laurent and his team's curiosityis stronger than their fear.
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They decided to scoutthe location at night,
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amidst hundreds of sharks.
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[in French] What we observed,
when we discovered these grounds,
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was that during the day, the sharks
that were clustered at mid-depth
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would suddenly swim to the bottom,
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and start raiding hither and thither
at the bottom of the pass.
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We didn't dare get close to them.
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We stayed above, 10 meters above them.
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We filmed them from afar, with our kneescurled up near our shoulders.
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We were terrified to letanything dangle near those jaws.
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The water was seething with sharks,an impenetrable ball of them.
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[rustling]
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We started daring to dive a little deeper,
on the edges.
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Maintaining a distance,
but a little closer to the bottom.
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It was still impenetrable. What goes on,
in the very center of the pack
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when we're around it?
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Filming at that depth, once in a whilewe would get nudged by the sharks.
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[grunting]
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Damn!
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We realized that we weren't targets
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we were just obstacles.
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[grunting, yelling]
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Damn!
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That's when we figured there was
a semblance of a social system.
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We began to suspect we were
seeing various predatory strategies.
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We had a hunch...
It aroused our intuition.
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I thought, let's test this hunch.
Let's see if it's scientific fact.
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[narrator] Laurent hopes to prove
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that the sharks aremuch smarter than we think.
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The next few days are critical:
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the June full moon will triggerthe grouper gathering.
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That's when the sharkswill go on the rampage.
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The moon is a ticking clockfor both the scientists and the fish;
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a countdown to a massacre.
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[loud explosion]
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700 sharks aren't gatheringat Fakarava by chance.
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They're here because ofthe history of this island.
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Knowing the geological pastreveals the biological present.
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Fakarava was born around70 million years ago.
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[rumbling]
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No sooner had the volcano surged upfrom the depths of the Pacific Ocean
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than the reefs startedcolonizing its shoreline.
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Soon the island was surroundedby a ring of coral.
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In the north,the freshwater from the rivers
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stopped the coral from growing there,
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which left a gap in the reefalmost two miles wide.
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Its fires extinct,over the next two million years,
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the volcano disappeared,while the reef kept on growing.
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But it still bears the imprintof the ancient rivers:
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the channels.
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The pass in the northtakes the brunt of the tides,
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so the residual current that reachesthe south channel here is gentle.
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This easy current is a real boon.
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It's weak enough for the coral to develop,
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and provides shelter for fish,
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yet it's strong enough to allowa constant flow of food for everyone.
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[soft instrumental music playing]
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Sharks thrive in this current, too.
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By day they use it to rest;by night they use it to hunt.
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This perfectly adapted currentis the first clue
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to understanding why sharks gather here.
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[birds calling]
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But to see the whole picture,
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Laurent needs to dissectthe predators' movements.
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He's tasked three scientiststo create a 3D model
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to help him do just that.
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They'll begin by placing antennasdown at the bottom of the pass.
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[Yannis Papastamatiou]
The strength of the current isn't equal.
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If we know approximately where they are
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in the channel, and how active they are,
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and we have some understanding
of current strength,
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then we can really see
how their behavior varies.
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[Charlie Huveneers]
Based on the range of testing we did,
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we probably need to space the
receivers about 100 meters apart.
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[Johann Mourier] Yeah. Exactly.
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[Huveneers] Right now
we're trying to find the best position
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for these acoustic receivers
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to make sure that we are going
to get the tagged shark
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where the sharks are spending
most of their time,
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so on the hot spots around the walls.
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Uh, but also, where they're going to be,
uh, hunting at night
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so we can compare the activity
during the day and the night.
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[Mourier] We have a big school
of sharks usually staying here,
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all along this place.
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So, all these receivers
can get, uh, the detection.
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[Huveneers, off screen] Cool.
We'll just have to deploy them now.
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[tense instrumental music playing]
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[narrator] They have to getgovernment permission
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to install 25 antennas,
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since the sharks hereare protected by law.
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[Papastamatiou] 22 is 101799.
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113122.
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[narrator] But installing25 antennas is the easy part.
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[Papastamatiou] 115334.
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[narrator] The next step is toequip 40 sharks
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with electronic chips, so theycan track their every move.
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[tense instrumental music playing]
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The gray sharks are keepingtheir distance;
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like the divers, they're cautious.
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These predators are also preyto 13-foot-long hammerheads.
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[dramatic music playing]
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[grunting]
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[dramatic instrumental music playing]
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[Papastamatiou] Good with that,
so we have the VHF works just fine.
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[narrator] With the antennas installed,
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it's time to figure outhow to plant the chips
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in the sharks' abdomens.
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The chips will let the scientists knowexactly when the predators go into action;
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whether they sometimes leave the channel;
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and if all 700 act as one,or independently.
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[Huveneers] It's pretty handy
to have a shark right here.
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[Mourier] Yeah.
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[narrator] If everything goes as planned,
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they'll be able to trackthe movements of each shark.
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And the team has another toolat its disposal:
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a spy camera covered in sensors,
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ready to be attached to a shark.
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[Papastamatiou]
Well, let's try it and see.
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[narrator] This is Yannis's firstdive at night
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into the middle of the pack.
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He and Laurent are going to test placingthe spy camera on a shark
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using a surprising technique.
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But the sharks may not cooperate.
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[narrator] Scientists inthe Pacific atoll of Fakarava
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have to work in the dark,
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because the sharks aretoo cautious during the day,
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and unapproachable.
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At night, they're emboldened by the hunt.
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[dramatic music playing]
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Research has shown that turninga shark over on its back
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puts it into a hypnotized,cataleptic state.
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But that was done with sharksfamiliar with divers
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and fed by them.
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Now Laurent and his teamare testing it here,
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amid a feeding frenzy.
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Amazingly, the immobilizationtechnique works.
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This is one circus move thatcould end up scientific protocol.
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[muffled speaking]
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They need a big shark to carry the camera.
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Coordination betweenthe two scientists is crucial.
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Each shark reacts differently.
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Some won't be hypnotized,and that's when they might bite.
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Yannis thinks this one's too small.
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Laurent lets it go.
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While they're searchingfor a larger shark,
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a never-before-documented huntis going on.
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It's a moray eel.
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-[dramatic music playing]
-[camera shutter clicking]
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A lone gray shark will neverattack a moray eel this big,
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but together, this pack doesn't hesitate.
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After two hours,Yannis and Laurent give up.
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It's too difficult to attach the camera.
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They need to find another way, and soon.
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[thunder rumbling]
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Back at HQ, Yannis screensthe first images.
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Something strikes him.
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It looks like the sharksmight form partnerships
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to hunt in pairs.
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One of the most, uh, fascinating things
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about the, uh,
the sharks in Fakarava channel
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is the social systems
of the sharks themselves.
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The question is, why do they
form these social associations?
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By remaining close to each other,
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one shark could see another
shark taking some prey,
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and benefit from that.
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So if you imagine,
there's a reef fish here,
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one shark sees it, charges,
goes after the reef fish, it escapes.
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Another shark sees that shark
chasing the reef fish,
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then it sees the reef fish,
and it actually successfully gets it.
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By hanging out close to each other,
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I can see if you get some food or chasesome prey, and that can benefit me.
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Very simple, but that could still drive
us forming social associations.
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[narrator] There mightbe something to this partnership theory,
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but it uncovers more mysteries to solve.
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Are the pairs partners or rivals?
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Does a pair always hunt together?
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Do they hunt every night?
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A shark only needs from sevento nine pounds of fish a week;
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so theoretically, it doesn'tneed to go hunting every 24 hours.
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The electronic chips may helpthe team find answers.
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But only if they canfind a way to attach them
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to these deadly predators.
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[splashing]
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[intense instrumental music playing]
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Everywhere else in the world,
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scientists fish for sharkswith hook and line
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in order to mark them.
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But here in Fakarava Atoll,
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the scientists have decidedto immobilize them by hand
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and then lasso them to get themup next to the boat.
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Nobody's ever triedthis old cowboy technique
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on a gray reef shark before...only on whitetip reef sharks.
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It's much less invasive for the shark,
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but there's a high riskof someone getting bitten.
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One problem with hypnosisis the creature's weight.
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If a shark's not swimming, it sinks.
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So if you immobilize one,it tends to drop down,
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bringing its jawsright up against your legs.
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[muffled speaking]
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[Ballesta] Damn!
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No!
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[narrator] Laurent's taken it onas a challenge.
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He's determined to get it done.
251
00:17:22,480 --> 00:17:25,680
[Huveneers] Okay, Yannis,
you need to do the slack,
252
00:17:25,760 --> 00:17:27,600
-you can do the slack.
-[Papastamatiou] Yup.
253
00:17:27,680 --> 00:17:28,960
[Huveneers] Johann.
254
00:17:29,040 --> 00:17:30,680
Watch out, Yannis, I'm going to
pull it from the other side.
255
00:17:30,760 --> 00:17:32,200
-Watch out, watch out.
-[Papastamatiou] Here?
256
00:17:32,280 --> 00:17:33,320
[Huveneers] Good, good.
257
00:17:38,400 --> 00:17:40,520
[Mourier, in French] Slack.
Give it slack, slack, slack, slack.
258
00:17:44,640 --> 00:17:47,320
[Huveneers] Good one,
good one, guys. We're on.
259
00:17:48,480 --> 00:17:49,480
[indistinct chatter]
260
00:17:50,240 --> 00:17:52,560
One, two, three.
261
00:17:54,480 --> 00:17:56,760
-[thrashing]
-[grunting]
262
00:17:59,440 --> 00:18:00,640
[man] There you go.
263
00:18:02,680 --> 00:18:03,720
[Mourier] Yep.
264
00:18:05,720 --> 00:18:07,040
[Papastamatiou] Oh, there goes the...
265
00:18:08,840 --> 00:18:09,920
[Mourier] Good boy.
266
00:18:10,880 --> 00:18:12,520
[Huveneers]
Gonna touch again. Here you go.
267
00:18:12,600 --> 00:18:14,720
-[Papastamatiou] There we go.
-[Huveneers] Close, close, close, close.
268
00:18:19,840 --> 00:18:21,400
[Mourier, in French]
When the shark is belly up,
269
00:18:21,480 --> 00:18:24,720
he's much calmer,
so it's easier for us to tag him.
270
00:18:24,800 --> 00:18:28,080
Also, the shark is much less stressed
out, when he's belly up.
271
00:18:30,600 --> 00:18:33,960
[narrator] Yannis tries toimplant the first electronic chip.
272
00:18:34,560 --> 00:18:40,520
[intense music playing]
273
00:18:43,640 --> 00:18:45,840
[Mourier] The surface of the skin
is very hard, eh?
274
00:18:45,920 --> 00:18:48,320
[Papastamatiou] There's a lot of
really thick muscle layer
275
00:18:48,400 --> 00:18:50,800
until you get into the body cavity.
276
00:18:50,880 --> 00:18:54,800
So, although these incisions
look quite dramatic,
277
00:18:54,880 --> 00:18:56,640
there's a few things to keep in mind.
278
00:18:56,720 --> 00:19:00,800
First of all is that sharks
naturally have pretty violent lives,
279
00:19:00,880 --> 00:19:02,560
especially when they mate.
280
00:19:02,640 --> 00:19:05,960
So the male will bite the female,
281
00:19:06,040 --> 00:19:08,480
and the females in particular
can get pretty torn up.
282
00:19:08,560 --> 00:19:13,360
So we get females with huge, huge scars,
much, much larger than anything
283
00:19:13,440 --> 00:19:14,920
we're inflicting with this,
with this blade.
284
00:19:15,480 --> 00:19:19,560
So they're naturally adapted
to having a lot of damage.
285
00:19:19,640 --> 00:19:23,240
And because of that, they have
very impressive immune systems
286
00:19:23,320 --> 00:19:25,480
and very, very fast healing rates.
287
00:19:25,560 --> 00:19:30,040
So we've caught sharks a couple
days after, after tagging,
288
00:19:30,120 --> 00:19:33,200
and the wound is already healed up.
289
00:19:39,360 --> 00:19:41,440
-[Huveneers] You can let go.
-[Mourier] Yeah.
290
00:19:41,520 --> 00:19:43,360
[Huveneers] Uh, one, two, three.
Flip it and untie him.
291
00:19:44,920 --> 00:19:48,120
Flip it. It's gonna go by itself. Perfect.
292
00:19:48,200 --> 00:19:50,120
At least we know she's healthy.
293
00:19:59,000 --> 00:20:01,280
[narrator] The team hopes to tagat least 40 sharks
294
00:20:01,360 --> 00:20:04,280
and then follow them for a whole year.
295
00:20:04,360 --> 00:20:07,360
They'll know everythingthe sharks get up to:
296
00:20:07,440 --> 00:20:10,440
if they leave the channel or stay there;
297
00:20:10,520 --> 00:20:13,400
if they hunt every night;
298
00:20:13,480 --> 00:20:15,840
if they all hunt together;
299
00:20:15,920 --> 00:20:19,760
and if they're influencedby the lunar cycles.
300
00:20:19,840 --> 00:20:21,920
[dramatic music playing]
301
00:20:25,760 --> 00:20:30,360
But tagging 40 sharksis easier said than done.
302
00:20:33,040 --> 00:20:35,320
[Ballesta] Oh, my God!
303
00:20:42,480 --> 00:20:44,280
[narrator] Here in the Fakarava channel,
304
00:20:44,360 --> 00:20:48,160
scientists are tagging sharksusing a lasso technique,
305
00:20:48,240 --> 00:20:51,840
while trying to avoid beingattacked by other sharks.
306
00:20:57,720 --> 00:20:59,680
[Huveneers, off screen] One, two, three.
307
00:21:01,960 --> 00:21:03,600
[Papastamatiou] Oh, there it goes.
308
00:21:06,400 --> 00:21:08,360
[Mourier, in French] This shark may have
been bitten while mating...
309
00:21:08,920 --> 00:21:11,720
Or while they were attacking prey.
310
00:21:11,800 --> 00:21:15,360
Sometimes they snap at each other.
311
00:21:15,440 --> 00:21:18,840
[Huveneers] It's a male, guys. First male.
312
00:21:18,920 --> 00:21:20,480
[narrator] This shark's bigger,
313
00:21:20,560 --> 00:21:23,440
so Yannis will try to attachthe spy camera.
314
00:21:26,080 --> 00:21:28,240
[Papastamatiou] Come back to me. [kisses]
315
00:21:29,120 --> 00:21:30,560
[Huveneers] Find it out. Yeah.
316
00:21:30,640 --> 00:21:31,680
[Mourier] Okay, I know.
317
00:21:34,440 --> 00:21:38,760
[splashing]
318
00:21:38,840 --> 00:21:40,640
-[Papastamatiou] Good?
-[Huveneers] Yeah.
319
00:21:40,720 --> 00:21:42,120
[Papastamatiou] Okay.
320
00:21:44,320 --> 00:21:47,960
[Huveneers] It's the best way to do it.
321
00:21:48,040 --> 00:21:51,200
[Papastamatiou] Okay.
Push forward, Johann, let go.
322
00:22:02,160 --> 00:22:04,120
[narrator] They've taggednine sharks on the first night,
323
00:22:05,640 --> 00:22:08,680
but they're still a long wayfrom their goal of 40.
324
00:22:08,760 --> 00:22:12,600
[soft instrumental music playing]
325
00:22:16,120 --> 00:22:19,080
The team's been countingthe sharks every three days:
326
00:22:19,160 --> 00:22:23,560
416, then 480, 520;
327
00:22:23,640 --> 00:22:27,320
the number keeps risingas the full moon approaches.
328
00:22:27,400 --> 00:22:32,160
By day, the sharks form threegroups that the divers call "walls,"
329
00:22:32,240 --> 00:22:35,440
an expression coinedby explorers in the 1960s
330
00:22:35,520 --> 00:22:38,760
who were the first to seehundreds of sharks lined up like this.
331
00:22:43,160 --> 00:22:46,520
The walls form at very precise locations.
332
00:22:46,600 --> 00:22:49,520
For four years, Laurent's teamhas been observing
333
00:22:49,600 --> 00:22:53,440
that the sharks rest on veinsof current in the channel.
334
00:22:58,960 --> 00:23:02,840
Whenever they leave the vein of current,others come in to replace them:
335
00:23:02,920 --> 00:23:05,760
just like migrating birds in v-formations.
336
00:23:10,120 --> 00:23:13,880
They only stop to get their teeth cleanedby the cleaner fish.
337
00:23:37,320 --> 00:23:39,400
The scientists discover that the camera
338
00:23:39,480 --> 00:23:41,560
has fallen off the shark.
339
00:23:41,640 --> 00:23:45,800
Yannis Papastamatiou looks for cluesto the pack's behavior.
340
00:23:49,440 --> 00:23:51,000
[Papastamatiou]
So one of the things we can see
341
00:23:51,280 --> 00:23:52,880
when we take a look at this video
342
00:23:52,960 --> 00:23:55,040
is that our shark carrying the camera
343
00:23:55,120 --> 00:23:57,680
is often associatingwith this individual here
344
00:23:57,760 --> 00:23:59,400
with the damaged dorsal fin.
345
00:23:59,480 --> 00:24:02,360
So that may mean that there maybe some form of social bond
346
00:24:02,440 --> 00:24:05,240
between those two sharks.And next we want to know
347
00:24:05,320 --> 00:24:08,800
if that also applies at night.So do these animals, for example,
348
00:24:08,880 --> 00:24:11,720
form social bonds while they are hunting?
349
00:24:11,800 --> 00:24:16,240
[soft instrumental music playing]
350
00:24:17,960 --> 00:24:20,000
[narrator] It's almost the full moon.
351
00:24:21,920 --> 00:24:26,680
So it's time to deployLaurent's most complex brainchild.
352
00:24:26,760 --> 00:24:29,600
This arch combines bothphotography and video
353
00:24:29,680 --> 00:24:32,960
in order to capture the huntat one-hundredth of a second,
354
00:24:33,040 --> 00:24:36,400
and then, with its32 synchronized cameras,
355
00:24:36,480 --> 00:24:39,200
move around inside the 3D image.
356
00:24:43,080 --> 00:24:44,840
The team has no idea what
357
00:24:44,920 --> 00:24:48,880
the sharks will makeof this high-tech stranger.
358
00:24:48,960 --> 00:24:53,200
The first shots are taken indaytime, amidst all the fish.
359
00:24:53,280 --> 00:24:55,920
But only the oncoming darkness will reveal
360
00:24:56,000 --> 00:25:00,920
what happens when 700 sharksbecome 700 hunters.
361
00:25:08,400 --> 00:25:11,040
[diver] Go, go, go, go!
362
00:25:19,440 --> 00:25:22,360
[narrator] In daylight, resultsfrom the shark scientists'
363
00:25:22,440 --> 00:25:24,880
3D arch look promising.
364
00:25:24,960 --> 00:25:28,480
Now they must wait for lightto turn to night.
365
00:25:33,040 --> 00:25:36,440
The channel is not so mucha well-stocked pantry.
366
00:25:36,520 --> 00:25:38,800
It's more like a conveyor belt of food,
367
00:25:38,880 --> 00:25:43,040
rolling ever faster asthe June full moon approaches.
368
00:25:43,120 --> 00:25:48,400
There's enough prey nowto feed a lot of hungry sharks.
369
00:25:48,480 --> 00:25:52,320
One after another, dozens ofspecies of fish from the lagoon
370
00:25:52,400 --> 00:25:56,880
are arriving to the channel, asif to a prearranged rendezvous.
371
00:25:56,960 --> 00:26:00,080
They're all getting into placeat the ocean gate
372
00:26:00,160 --> 00:26:02,760
to give their larvae a chance of survival
373
00:26:02,840 --> 00:26:06,240
far from all of the predators of the reef.
374
00:26:06,320 --> 00:26:09,240
They are ready to launchtheir spawn into the current,
375
00:26:09,320 --> 00:26:11,200
and out to sea.
376
00:26:11,280 --> 00:26:16,320
[dramatic music playing]
377
00:26:22,800 --> 00:26:27,880
[dramatic music continues]
378
00:26:32,840 --> 00:26:34,280
For the moment,
379
00:26:34,360 --> 00:26:36,960
there are only a fewgrouper fish in the channel;
380
00:26:37,040 --> 00:26:41,200
but soon there will be as many as 17,000.
381
00:26:41,280 --> 00:26:43,400
And the sharks know it.
382
00:26:43,480 --> 00:26:47,560
This honeymoon is aboutto turn into a bloodbath.
383
00:26:53,200 --> 00:26:56,480
[narrator] Just days untilthe 700-shark feeding frenzy,
384
00:26:57,520 --> 00:27:01,360
scientists prepare to documentthe spectacular event.
385
00:27:01,440 --> 00:27:02,440
[whooshing]
386
00:27:07,120 --> 00:27:10,000
While Antonin and Thibaultwork on the arch,
387
00:27:10,080 --> 00:27:12,840
it's Yannis's last night on the mission.
388
00:27:12,920 --> 00:27:17,120
He's at last placing the 40thand final electronic tag.
389
00:27:23,880 --> 00:27:26,040
As the darkness of night falls,
390
00:27:26,120 --> 00:27:30,320
the fish are half asleepand less aware of danger.
391
00:27:30,400 --> 00:27:33,120
That's when a shark makes its move.
392
00:27:38,800 --> 00:27:40,400
The high-speed video reveals
393
00:27:40,480 --> 00:27:42,920
the different phases of an attack.
394
00:27:43,000 --> 00:27:45,960
The sharks are obviouslyattracted by sound.
395
00:27:46,040 --> 00:27:49,200
Vision helps, too,but here in the shadows,
396
00:27:49,280 --> 00:27:52,640
the shark has a special advantage:
397
00:27:52,720 --> 00:27:55,760
It can detect theelectromagnetic field of the fish
398
00:27:55,840 --> 00:27:57,600
with the aid of sensitive cells
399
00:27:57,680 --> 00:28:01,600
all around its mouth,called ampullae of Lorenzini.
400
00:28:03,720 --> 00:28:05,680
The electrical stimulation
401
00:28:05,760 --> 00:28:08,600
only works up to a footfrom the shark's mouth.
402
00:28:08,680 --> 00:28:12,560
[dramatic music playing]
403
00:28:17,200 --> 00:28:18,840
The more agitated the fish,
404
00:28:18,920 --> 00:28:21,920
the more intenseits electromagnetic field.
405
00:28:22,000 --> 00:28:24,240
If it could play dead,the shark would think
406
00:28:24,320 --> 00:28:27,160
it was an inanimate object, and ignore it.
407
00:28:39,960 --> 00:28:40,960
[intense music playing]
408
00:28:46,120 --> 00:28:48,160
On its own, a shark is clumsy.
409
00:28:48,240 --> 00:28:51,920
It's at its best in a pack,with everyone moving together.
410
00:28:54,600 --> 00:28:59,280
The images reveal that 25% ofthe pack's attempts are successful.
411
00:28:59,360 --> 00:29:03,360
Compare that to a pack of wolves,renowned for its efficiency,
412
00:29:03,440 --> 00:29:06,440
that only catches 14% of its prey.
413
00:29:08,200 --> 00:29:13,280
The photos show them encirclingtheir prey to cut off any escape.
414
00:29:13,360 --> 00:29:15,960
Teamwork is clearly an advantage.
415
00:29:16,040 --> 00:29:19,480
Once the prey's cornered,though, it's a different story.
416
00:29:19,560 --> 00:29:22,520
Every shark demands their share.
417
00:29:22,600 --> 00:29:26,640
At Fakarava, there's no lackof prey, so it's not a problem.
418
00:29:26,720 --> 00:29:31,040
Sooner or later, every oneof those snapping jaws will be fed.
419
00:29:33,360 --> 00:29:37,240
But jaws are uselessif the prey stays hidden.
420
00:29:39,520 --> 00:29:42,440
The team makes a remarkable observation:
421
00:29:42,520 --> 00:29:44,760
the gray sharks followthe whitetip sharks,
422
00:29:44,840 --> 00:29:46,960
also known as coral sharks,
423
00:29:47,040 --> 00:29:48,920
who, with their ability to slip into holes
424
00:29:49,000 --> 00:29:50,640
and come out again backwards,
425
00:29:50,720 --> 00:29:54,760
are the only ones who can flushout prey hiding in the reef.
426
00:29:54,840 --> 00:29:59,840
[intense music playing]
427
00:30:13,120 --> 00:30:16,160
It's a new and enlighteningfacet of their behavior:
428
00:30:16,240 --> 00:30:20,400
This shark pack can exploitthe skills of another species.
429
00:30:46,400 --> 00:30:49,240
The chips on the tagged sharkssend information
430
00:30:49,320 --> 00:30:53,520
each time they pass closeto one of the many antennas.
431
00:30:53,600 --> 00:30:56,280
After a week, Johann and Antonin
432
00:30:56,360 --> 00:30:58,680
collect the data to assess it.
433
00:31:00,680 --> 00:31:01,680
[speaking French]
434
00:31:02,840 --> 00:31:04,440
The antennas will be returned
435
00:31:04,520 --> 00:31:06,440
each night to continue the tracking.
436
00:31:09,120 --> 00:31:11,680
[Ballesta, in French]
So, there's a different color
437
00:31:11,760 --> 00:31:14,440
for each of the sharks we tagged.
438
00:31:14,520 --> 00:31:17,960
[in French] You can really see two groups.
One group stays around here...
439
00:31:18,040 --> 00:31:21,040
On the ocean side of the dropoff.
440
00:31:21,120 --> 00:31:23,520
And the other group is much more active...
441
00:31:23,600 --> 00:31:26,080
They mainly use that main pass by day.
442
00:31:26,160 --> 00:31:30,120
These waters, here...
And actually, after nightfall,
443
00:31:30,200 --> 00:31:32,040
they swim much more in this area.
444
00:31:32,120 --> 00:31:34,760
Another thing we'll be able
to see is if there are leaders.
445
00:31:34,840 --> 00:31:39,240
We see there are groups of sharks
that move together, more or less.
446
00:31:39,320 --> 00:31:42,200
We'll see if it's always the same shark
who starts the move.
447
00:31:43,400 --> 00:31:45,600
[narrator] With only three daysuntil the full moon,
448
00:31:45,680 --> 00:31:48,720
the team makes their final preparations.
449
00:31:48,800 --> 00:31:52,240
The arch will make its debutamong hundreds of sharks,
450
00:31:52,320 --> 00:31:55,640
right in the middleof a massive shark attack.
451
00:31:58,560 --> 00:32:01,480
[narrator] As night fallstwo days before the full moon,
452
00:32:01,560 --> 00:32:03,880
the sharks seem undisturbed by the arch
453
00:32:03,960 --> 00:32:07,600
and just keep on hunting,right under the divers' feet.
454
00:32:07,680 --> 00:32:09,840
It's becoming clear that whether
455
00:32:09,920 --> 00:32:12,760
they're resting during the dayor on the attack at night,
456
00:32:12,840 --> 00:32:18,440
the sharks form partnerships,subgroups that work together.
457
00:32:18,520 --> 00:32:21,560
High-speed footage fromthe arch reveals what happens
458
00:32:21,640 --> 00:32:23,800
at the heart of an attack.
459
00:32:27,560 --> 00:32:29,920
The shark on the right is driving the prey
460
00:32:30,000 --> 00:32:31,920
straight towards the other.
461
00:32:33,640 --> 00:32:36,640
Slow motion reveals hunting duos.
462
00:32:39,920 --> 00:32:43,440
In addition to the pack'soverall synchronization,
463
00:32:43,520 --> 00:32:46,080
they seem to have a deeperlevel of organization
464
00:32:46,160 --> 00:32:50,000
based on either momentary ormore durable mutual interests.
465
00:32:52,280 --> 00:32:56,800
The prey can escape once,maybe twice, but not forever.
466
00:32:58,320 --> 00:33:00,920
In fact, this coordination is a mixture
467
00:33:01,000 --> 00:33:04,240
of cooperation and competition.
468
00:33:04,320 --> 00:33:08,080
They watch more than they helpeach other; but it works.
469
00:33:08,640 --> 00:33:10,960
If one doesn't win out, the other does.
470
00:33:19,240 --> 00:33:22,360
Nearly 600 sharks hunt here now:
471
00:33:22,440 --> 00:33:25,760
The ranks of the predatorsare swelling every night.
472
00:33:33,760 --> 00:33:36,680
[beeping]
473
00:33:38,680 --> 00:33:40,800
[Ballesta, in French]
We're part of the pack, now!
474
00:33:40,880 --> 00:33:42,960
[Cedric Gentil, in French]
That's the feeling I had.
475
00:33:43,320 --> 00:33:48,000
And there you go... You're with them.
476
00:33:48,080 --> 00:33:53,160
Sometimes you feel like taking one under
each arm, and walking along with them.
477
00:33:53,240 --> 00:33:55,800
Sharks everywhere!
They didn't let us down!
478
00:33:55,880 --> 00:33:58,640
It seems like there are more every year.
479
00:33:58,720 --> 00:34:00,880
[Yanick Gentil, in French]
Youngsters. Lots of youngsters.
480
00:34:00,960 --> 00:34:04,520
Right... There are lots of
youngsters who are... about yay big.
481
00:34:04,600 --> 00:34:06,480
[Gentil] Didn't you call one "Papa?"
482
00:34:07,360 --> 00:34:09,000
[Ballesta] I didn't dare admit it.
483
00:34:11,680 --> 00:34:15,440
[soft instrumental music playing]
484
00:34:35,240 --> 00:34:37,320
[narrator] For 50 nightsthey've been diving,
485
00:34:37,400 --> 00:34:41,400
and now on the 51st,it's the day before the full moon,
486
00:34:41,480 --> 00:34:46,480
the most important night for the sharksand for Laurent and his team.
487
00:34:48,400 --> 00:34:51,080
The surveillance cameragives the go-ahead.
488
00:34:51,160 --> 00:34:54,200
And just like every yearat this same time,
489
00:34:54,280 --> 00:34:56,040
the groupers are back.
490
00:34:58,160 --> 00:35:00,360
They're solitary all year round,
491
00:35:00,440 --> 00:35:02,640
but get together for the annual spawn.
492
00:35:02,720 --> 00:35:05,720
No one misses the date:the full moon in June.
493
00:35:05,800 --> 00:35:07,720
And you don't need to study the stars
494
00:35:07,800 --> 00:35:10,080
to see that all the females are pregnant.
495
00:35:22,480 --> 00:35:25,640
This is the day the sharkshave been waiting for...
496
00:35:25,720 --> 00:35:27,920
all 700 of them.
497
00:35:30,960 --> 00:35:33,760
Tonight will put to the testall the latest theories
498
00:35:33,840 --> 00:35:35,960
about how the pack functions.
499
00:35:43,720 --> 00:35:46,360
The attack will comefrom within the channel
500
00:35:46,440 --> 00:35:48,520
where the sharks are resting.
501
00:35:50,680 --> 00:35:53,560
The countdown to a massacre has begun.
502
00:36:32,520 --> 00:36:38,120
[ominous music playing]
503
00:36:45,360 --> 00:36:48,160
The groupers come hereto reproduce once a year,
504
00:36:48,240 --> 00:36:50,000
entirely driven by instinct.
505
00:36:53,160 --> 00:36:57,120
While waiting for the femalesto spawn, the males hide.
506
00:36:57,200 --> 00:36:59,680
Don't hide, and you're dead.
507
00:37:00,840 --> 00:37:02,760
Night is falling now.
508
00:37:02,840 --> 00:37:05,440
The pack is waking up,
509
00:37:05,520 --> 00:37:07,400
and they're hungry.
510
00:37:15,400 --> 00:37:16,760
[narrator] 700 sharks swarm their prey.
511
00:37:24,680 --> 00:37:26,360
[intense music playing]
512
00:37:30,320 --> 00:37:35,000
A tornado of jaws,followed by a rain of scales.
513
00:37:37,400 --> 00:37:39,200
It's a deadly roundabout.
514
00:37:41,960 --> 00:37:43,840
[lively, intense music playing]
515
00:37:49,080 --> 00:37:52,920
Electroreceptors helpthe sharks zero in on prey.
516
00:37:59,480 --> 00:38:02,680
For the groupers,this is the price they pay
517
00:38:02,760 --> 00:38:04,440
to spawn the next generation.
518
00:38:10,880 --> 00:38:14,760
Though the sharks hunt in a pack,they don't like to share.
519
00:38:16,760 --> 00:38:22,000
[intense music playing]
520
00:38:45,240 --> 00:38:47,080
Some bear deep scars,
521
00:38:47,160 --> 00:38:50,400
perhaps from battles withother sharks at the hunt.
522
00:38:50,480 --> 00:38:54,640
[intense music playing]
523
00:39:06,680 --> 00:39:10,600
This grouper has managed toslip through three sets of jaws.
524
00:39:14,040 --> 00:39:15,800
But not the fourth.
525
00:39:15,880 --> 00:39:20,160
[intense music playing]
526
00:39:49,600 --> 00:39:53,880
A parrotfish, half asleep,bumps into a coral shark.
527
00:39:53,960 --> 00:39:57,400
In its haste, the gray sharkbites the coral shark
528
00:39:57,480 --> 00:39:59,560
and the parrotfish escapes.
529
00:40:05,480 --> 00:40:10,160
Weighed down by her huge belly,a female can't get away.
530
00:40:10,240 --> 00:40:14,480
Her eggs are scattered... and lost.
531
00:40:57,480 --> 00:41:00,680
At midnight,the full moon is at its zenith
532
00:41:00,760 --> 00:41:03,280
and lights up the whole ocean bed.
533
00:41:03,360 --> 00:41:06,640
But by 5:00 in the morningit's low on the horizon
534
00:41:06,720 --> 00:41:11,040
and the sharks are all leftin the dark, exhausted.
535
00:41:11,120 --> 00:41:15,600
The hunt finally eases,the groupers know it,
536
00:41:15,680 --> 00:41:17,400
and the spawning begins.
537
00:41:31,400 --> 00:41:35,440
In the darkness,the sharks seem less alert.
538
00:41:35,520 --> 00:41:37,880
The lights from the camerasdon't affect them;
539
00:41:37,960 --> 00:41:39,360
they're too patchy.
540
00:41:44,440 --> 00:41:48,040
Sharks have evolvedinto the ultimate predators;
541
00:41:48,120 --> 00:41:51,200
but their prey has evolved, too.
542
00:41:51,280 --> 00:41:53,800
The groupers, with speedand perfect timing,
543
00:41:53,880 --> 00:41:57,200
have learned to spawnat this opportune moment.
544
00:41:57,280 --> 00:41:58,280
[lively music playing]
545
00:42:02,680 --> 00:42:06,600
Both prey and predator havestrengths and weaknesses.
546
00:42:06,680 --> 00:42:08,520
The groupers are less vulnerable
547
00:42:08,600 --> 00:42:10,560
than the biologists imagined,
548
00:42:10,640 --> 00:42:13,480
and sometimes the sharksfail to hit their target.
549
00:42:33,440 --> 00:42:36,160
Four months have gone bysince the start of the mission,
550
00:42:36,240 --> 00:42:40,040
and the electronic tags continue toreveal the secrets of the shark pack.
551
00:42:46,840 --> 00:42:49,200
They seem to obey some rules.
552
00:42:49,280 --> 00:42:52,120
By day, they stay in three groups,
553
00:42:52,200 --> 00:42:55,200
make their rounds, and sleep a bit.
554
00:42:55,280 --> 00:42:57,120
They begin to form pairs.
555
00:42:59,080 --> 00:43:02,200
As night falls, they bandtogether for the hunt,
556
00:43:02,280 --> 00:43:04,960
forging partnerships thatpersist for the night,
557
00:43:05,040 --> 00:43:07,040
like sub-units within the pack,
558
00:43:07,120 --> 00:43:09,960
although it does not meanthese pairings will be the same
559
00:43:10,040 --> 00:43:11,480
on the next night.
560
00:43:11,560 --> 00:43:15,800
This behavior has neverbeen documented before.
561
00:43:15,880 --> 00:43:18,240
Three thousand hours of underwater filming
562
00:43:18,320 --> 00:43:21,760
reveals for the first time thata big school of gray sharks
563
00:43:21,840 --> 00:43:24,320
is more deadly than a pack of wolves.
564
00:43:26,360 --> 00:43:29,520
Even more remarkableand never before revealed,
565
00:43:29,600 --> 00:43:32,240
the sharks' activityfollows the lunar cycle
566
00:43:32,320 --> 00:43:36,200
much more than it followsthe abundance of prey.
567
00:43:36,280 --> 00:43:40,680
The level of moonlightdetermines the intensity of the hunt.
568
00:43:40,760 --> 00:43:44,000
And come morning, the sharks all return
569
00:43:44,080 --> 00:43:46,560
to their respective walls,
570
00:43:46,640 --> 00:43:49,640
with the exception ofat least two of the tagged 40,
571
00:43:49,720 --> 00:43:53,080
who leave the channel,and to this day have never returned.
572
00:43:55,000 --> 00:43:59,080
There are still mysteries to be solvedin the Fakarava channel,
573
00:43:59,160 --> 00:44:02,040
but one thing is clear:
574
00:44:02,120 --> 00:44:04,640
In these pristine waters,
575
00:44:04,720 --> 00:44:07,000
gray sharks rule.
52613
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