National Geographic Australia s Great Barrier Reef

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00:00:01 Australia's Great Barrier Reef
00:00:41 In the liquid skin of planet Earth
00:00:48 These tiny animals have crossed
00:00:51 and time in an epic bid
00:00:56 Wanderers through inner space,
00:00:58 they carry the future of
00:01:03 On their odyssey
00:01:05 they have faced extinction and
00:01:10 Theirs is
00:01:13 made possible by a remarkable
00:02:02 Reefs are exotic interruptions in
00:02:09 They're oases of life, vibrant,
00:02:18 But this vast canvas of living art
00:02:21 has not just materialized
00:02:24 Coral and its cohorts have arrived
00:02:30 Though they seem solid and unmoving,
00:02:33 reefs have spread themselves
00:02:39 How have they overcome
00:02:43 The answer has its origin
00:02:44 in one of life's most fundamental
00:02:50 But the reproductive rites of
00:02:51 coral communities are shrouded
00:02:56 It's only in the last ten years
00:02:58 that the reef has begun to
00:03:49 For animals sex is a fact of life,
00:03:53 but for the 'rocks' of the reef
00:03:55 a sex life would seem out of
00:03:58 But corals are not rocks,
00:04:04 Only the outer surface of
00:04:07 a living skin populated by polyps.
00:04:12 Their structure is simple,
00:04:14 a tube with a mouth surrounded
00:04:19 These tiny animals
00:04:25 The beauty of the individual rivals
00:04:42 A single pioneering polyp clones
00:04:44 or buds itself endlessly to
00:04:48 even thousands,
00:04:52 In theory a polyp could live
00:04:55 unchanging and unmoving.
00:04:59 But change and mobility are
00:05:04 On the reef sex achieves both in
00:05:11 It's a brief extravaganza,
00:05:15 and for the rest of the year
00:05:17 the priority is coping with
00:05:25 Inside the reff's barrier,
00:05:35 They inspect drifting particles.
00:05:38 Some are food,
00:05:39 some just broken parts of
00:05:42 but in the quiet lagoon every
00:05:51 A goatfish snuffles industriously.
00:06:01 Within a self-made sandstorm it
00:06:06 and mollusks which it locates
00:06:18 But the real heavy mover in the
00:06:25 The basic design is
00:06:27 that creeps around the
00:06:32 They push sand in one end...
00:07:03 Some sea cucumbers mop the reef
00:07:07 passing edible particles
00:07:13 Nature constantly tests and
00:07:18 the basic theme remains,
00:07:24 With its body completely buried
00:07:28 its feathery arms to
00:07:44 Every particle of sand in the
00:07:49 and plants that make up the reef.
00:07:51 Sand production is aided by
00:07:54 like the bumphead parrotfish.
00:08:01 Moving in herds like buffalo
00:08:04 they bite off pieces of coral,
00:08:06 crush it to powder and
00:08:07 leave clouds of new sand
00:08:15 The reef supports an endless
00:08:18 scrapers, and biters.
00:08:23 Many seem to bite at dead reef
00:08:25 but are actually cropping back a
00:08:31 The wastes of these schools of
00:08:34 as fertilizer to
00:08:37 The waters surrounding the reef
00:08:41 so recycling of its
00:08:46 It begins with the invisible haze
00:08:50 It continually showers the reef.
00:08:54 Just as plankton gather nutrients
00:08:57 fish like the spiny chromis
00:09:02 from the ocean are imported into
00:09:11 Poised like ghostly daggers,
00:09:16 they are after more than
00:09:19 These larger predators are drawn
00:09:47 Compared to the impoverished oceans
00:09:52 Built up from nothing
00:09:55 and plants it attracts investment
00:10:00 It becomes a bank, or storehouse,
00:10:12 But some creatures are
00:10:19 A sleek manta ray wings its way
00:10:23 It owes its huge bulk,
00:10:25 and wingspan of five meters to
00:10:29 it sieves from tropical waters.
00:10:42 Mantas are free agents,
00:10:45 They exploit the reef as and
00:10:50 They feed and then move on,
00:10:52 leaving each reef a little poorer
00:11:01 The blubber jelly voyages
00:11:05 feeding on plankton as it drifts.
00:11:16 Billowing in the currents its
00:11:26 Like all jellyfish
00:11:29 of the unmoving corals
00:11:35 Building on the skeletons of others,
00:11:37 hard corals extract calcium
00:11:41 Tiny polyps toil in limestone
00:11:44 to craft their biological
00:12:09 From the hard coral foundation
00:12:15 This ever expanding labyrinth
00:12:20 it creates living space
00:12:45 Bold against blue,
00:12:47 lace-like Gorgonians strain
00:12:55 On the reef slope,
00:13:00 Their flexible arms house polyps
00:13:04 these are no reef builders.
00:13:09 Lacking a solid skeleton,
00:13:11 they draw support from
00:13:13 tiny limestone spines
00:13:20 When the soft coral dies it
00:13:24 leaving no lasting monument.
00:13:36 Reef plants appear to be just as
00:13:39 ephemeral but their role is
00:13:41 All capture energy from sunlight
00:13:44 some also contribute to
00:13:50 The brittle green Halimeda is
00:13:54 It constantly sheds gritty lakes
00:13:59 The stony skin of
00:14:02 the limestone blocks of
00:14:06 Filamentous algae seems little
00:14:11 But it's the pasture of the reef,
00:14:13 and essential to
00:14:17 But the ties that bind algae
00:14:22 Like algae, hard corals also
00:14:29 This is a clue to
00:14:32 that literally fuels the reef.
00:14:36 Corals are twin-engined.
00:14:38 They're animals that have
00:14:41 to build the vast and
00:14:43 elaborate limestone structures
00:14:47 How have they done it?
00:14:50 Somewhere in their
00:14:54 a deal with microscopic
00:14:56 single-celled algae
00:14:59 The algae is sheltered inside
00:15:02 producing sugars from sunlight
00:15:08 This partnership became a most
00:15:13 Between them they built reefs.
00:15:17 It's not until the sun sets
00:15:20 that coral's second, animal,
00:15:33 As darkness falls, plankton
00:15:37 into the waters
00:15:42 From their stony lairs emerge...
00:15:54 Wreathed with stinging tentacles,
00:15:57 each polyp is poised to
00:16:19 Other members of
00:16:23 Feather stars take up strategic
00:16:27 They sieve plankton and
00:16:41 Slender prey,
00:16:43 a formation of razorfish
00:16:47 that hides their knifelike bodies.
00:16:55 A chaotic ball of eel-tailed catfish
00:17:01 Lagoon sands below them are
00:17:07 These miniature catfish scout for
00:17:11 aided by sensitive chin whiskers.
00:17:23 Lagoon sediments provide
00:17:25 for the feather-mouthed sea cucumber
00:17:29 Little more than an elastic tube
00:17:33 it delicately wipes each feathered
00:17:36 collecting food along with sand.
00:17:55 More robust sea cucumbers have
00:17:57 that make them unpalatable
00:18:01 They continue their slow work
00:18:04 and have no need to hide...
00:18:07 unlike the sophisticates
00:18:14 A hunter by night,
00:18:15 an octopus is able to change
00:18:21 Hiding and bluffing...
00:18:23 this stealthy camouflage expert
00:18:50 Its relative the cuttlefish shares
00:18:53 the octopus's talent for
00:19:03 Shunning camouflage altogether,
00:19:05 the flamboyant spanish dancer
00:19:12 Its colorful costume is
00:19:15 Like other nudibranchs,
00:19:18 the Spanish dancer looks
00:19:31 Overcome by darkness,
00:19:33 parrotfish retire into
00:19:37 Some of these daytime dandies
00:19:39 sleep in a gossamer cocoon of
00:19:43 Perhaps this mucous bubble
00:19:47 to unwelcome visitors.
00:19:49 A fast-moving vegetarian,
00:19:51 the parrotfish grazes algae
00:19:56 Clownfish may be left out
00:20:00 when their protective anemone
00:20:03 This is the reef's
00:20:12 The reef is a multi-layered organization
00:20:15 and its inhabitants have perfected
00:20:17 the art of living on and
00:20:22 Liaisons are everywhere
00:20:28 An ornamented anemone harbors
00:20:35 Competition for the reef's
00:20:39 When citizens live together
00:20:46 The blood-sucking fish louse
00:20:47 has a one-way relationship
00:20:52 Even corals are not exempt
00:20:57 Down among the valleys
00:21:00 A world that's never been seen.
00:21:16 Among the heaving tissues
00:21:18 live flatworms
00:21:23 Living on the thin veneer
00:21:26 these tiny lodgers appear to do
00:21:30 gliding like magic carpets in
00:21:49 On the reef every opportunity
00:21:56 Space is at a premium,
00:22:03 Invariably property disputes
00:22:09 Where two different species meet,
00:22:14 Nightly 'space wars,' fought
00:22:18 leave a conspicuous white
00:22:23 Surrounded, this fatal siege
00:22:29 A plate coral spreads outward
00:22:33 Here the problem is resolved by
00:22:42 Over time this living evolves.
00:22:46 Territorial struggles shape the reef
00:22:48 as a multitude of species
00:22:55 Shading its competitors from light,
00:22:57 the fast-growing plate corals
00:22:58 borrow a strategy from
00:23:06 Other inhabitants can neither
00:23:09 nor out-sting their competitors.
00:23:12 For sponges chemical warfare
00:23:16 Their tissues are
00:23:19 a kind of natural anti-fouling
00:23:25 Just as space invaders are part
00:23:42 Sometimes an opening comes
00:23:54 Storms and ocean swells
00:23:57 tearing long-lived corals
00:24:05 But not all space is
00:24:08 The crown of thorns starfish,
00:24:12 opens up new territory
00:24:19 And new settlers are
00:24:24 Out of the blue curtain
00:24:26 the currents propel a sea
00:24:30 a multitude of microscopic larvae.
00:24:36 This humble bean,
00:24:39 is the beginning of a new coral.
00:24:44 Equally disguised,
00:24:45 a larval sea urchin is
00:24:51 Even the giant clam begins
00:24:58 All reef larvae are designed to
00:25:04 To become citizens of a reef
00:25:05 they will need to take on
00:25:08 but first they must find
00:25:14 Journeying day and night
00:25:18 a sentinel in the dark sea.
00:25:22 But their sanctuary is
00:25:27 Night has unmasked the reef.
00:25:31 Poised and armed, it has become
00:25:39 The graceful Gorgonian is
00:25:43 its animal nature revealed.
00:25:46 Thousands of tiny polyps wait
00:25:58 A feather star sways
00:26:02 A million mouths wait in silence
00:26:05 for the microscopic voyagers
00:26:07 to blunder their way
00:26:19 The weaponry of the reef
00:26:21 a sinister array of traps, sieves,
00:26:25 harpoons and clutching tentacles
00:26:33 The methods may vary
00:26:35 but the final sentence will
00:26:41 And night after night this
00:26:50 Millions of epic voyages end in
00:27:32 Despite huge losses some larvae
00:27:35 survive their perilous
00:27:39 They grow to become solid citizens
00:27:42 joining the wall of mouths and
00:27:49 This endless lottery of
00:27:52 weaves a visual tapestry of species,
00:28:08 But beauty and harmony is a mask
00:28:14 Reef society is shaped in a war
00:28:35 The reef thrives in adversity,
00:28:37 prospering despite
00:28:43 But reefs have also
00:28:45 of planetary dimension over
00:28:52 Through the millennia
00:28:54 climates change,
00:29:00 As the world moves around them
00:29:02 coral reefs remain,
00:29:08 They seem at the mercy
00:29:11 today's have somehow survived 214
00:29:21 Coral reefs rim continental shelves
00:29:24 and cap volcanic sea mounts
00:29:33 But once, reefs lived in
00:29:39 It lay between two supercontinents
00:29:43 causing Africa and India to
00:29:47 The broad Tethys Sea, evolutionary
00:29:52 was squeezed out of existence.
00:29:54 Over millions of years
00:29:56 it became a war zone of
00:29:59 earthquakes and sea level change
00:30:02 and the animals evolving here
00:30:20 Amidst these shunting continents
00:30:24 extinction or escape.
00:30:27 Today's reefs are built by
00:30:31 that somehow dispersed and
00:30:32 evolved from their ancestral
00:30:37 But to escape the ravages
00:30:39 they had to play
00:30:43 This ace not only allowed them
00:30:48 It was sex.
00:30:50 And every summer the age-old
00:30:56 Shoals of tiny fry appear,
00:30:58 with their parents,
00:31:02 Their behavior is unusual
00:31:04 they guard their growing offspring.
00:31:09 A female cuttlefish holds an
00:31:13 She chooses a nest with great care
00:31:15 and places the fertile egg
00:31:29 But despite her plump maternalism
00:31:31 this is the extent of
00:31:37 From the time the egg is
00:31:40 the young cuttlefish will be
00:31:44 This careful handling of individual
00:31:48 and effort than most other reef
00:32:00 The giant clam makes no attempt
00:32:08 However it does invest enormous
00:32:10 and broadcasting many millions
00:32:17 With each mighty contraction the
00:32:24 Fish dart closer, feasting
00:32:37 Other, perhaps more prudent
00:32:41 before they begin to spawn.
00:32:49 The male coral trout emerge
00:32:53 With his tail flagged black he
00:32:59 Females are lying low on the reef,
00:33:01 their swollen bellies heavy
00:33:05 Concealed in the watery twilight
00:33:22 His elaborate dance is designed to
00:33:30 Reluctantly she leaves
00:33:33 encouraged by the ardent male.
00:33:40 The climax of their courting
00:33:44 A split second when eggs and
00:33:46 sperm are released near
00:33:51 ...leaving the future to chance,
00:33:57 As summer waters warm other
00:34:04 The reef below begins to stir.
00:34:10 Cued by the full moon in November,
00:34:12 countless coral polyps bulge.
00:34:15 They are ripe with packets of egg
00:34:18 and sperm that have taken
00:34:21 Their time has come.
00:34:36 Others respond to an unseen urge.
00:34:39 Crown of Thorns starfish begin
00:34:43 to high points on the reef.
00:34:51 Even inert creatures are stirring.
00:34:56 Sea cucumbers scurry...
00:34:59 away from the lagoon floor
00:35:04 Here they begin a sinuous dance,
00:35:08 swaying to an
00:35:35 Even the fragile feather mouth
00:35:39 This is an event
00:35:49 From within the bulging polyp
00:35:55 ...building to a slow spiral as
00:35:59 to its precious bundle of
00:36:07 This living jewel is the coral's
00:36:32 While polyps turn in time,
00:36:35 the hypnotic dance of
00:36:36 the sea cucumbers has reached
00:36:40 Males begin exuding sperm
00:36:49 They rear and sway to scatter
00:36:53 perhaps to meet the eggs
00:38:16 The Crown of Thorns smolders
00:38:19 releasing a misty cloud of sperm.
00:38:23 It drapes itself across coral
00:38:29 Now begins one of
00:38:32 and secret events in nature,
00:38:34 mass spawning
00:38:49 In unison, polyps pucker
00:38:51 and propel their fragile
00:38:56 Locked in limestone they cannot
00:39:00 Instead they reach out to each
00:39:10 Their cue is exact;
00:39:12 each year each species will spawn
00:39:39 We are privileged to be spectators
00:39:41 as the reef stages
00:39:46 Each night, for a week following
00:39:50 the intensity builds...
00:39:53 new species adding to the
00:40:01 Along 1200 kilometers of
00:40:05 countless millions of
00:40:15 Some corals are hermaphrodites
00:40:18 while others have separate colonies
00:40:31 Whatever their sex, each has
00:41:58 The synchronized spawning creates
00:42:02 for those with an appetite for it.
00:42:08 A hermit crab picks off eggs
00:42:15 But predators take only a fraction
00:42:19 Most pass unhindered into the sea.
00:42:23 And still the outpouring continues.
00:42:29 For these few nights of the year,
00:42:31 space wars seem insignificant.
00:42:34 Adversaries are united by powerful
00:42:40 The reef acts like
00:42:42 intent on securing its future.
00:43:05 Living rocks erupt in
00:43:08 and movement but the climax
00:43:29 Six nights after the full moon,
00:43:35 there is a kaleidoscopic finale.
00:43:40 The giant plate corals,
00:43:42 each with hundreds of
00:43:45 explode into ascending galaxies
00:44:23 The sea is now a soup of colored
00:44:28 but the performance is not yet over.
00:44:33 Incredibly, there is
00:44:41 The lagoon becomes laced
00:44:44 the reproductive segments of
00:44:48 seeming to bid bon voyage to
00:44:52 who set sail tonight,
00:45:19 As the frenzy of release subsidies,
00:45:22 the tide plays its part in the
00:45:27 The moon stills the restless sea
00:45:29 as egg and sperm bundles
00:45:36 Somehow, in this vast and
00:45:39 the right egg and right sperm will
00:45:57 Each morning the sea bears witness
00:46:01 as the future hopes of the reef
00:46:05 Here is the solution to
00:46:10 From this floating slick
00:46:12 the tiny developing larvae
00:46:18 Opportunists take advantage
00:46:21 but against the overwhelming
00:46:23 abundance they make
00:46:33 However, in the vast ocean
00:46:36 this ribbon of new life will
00:46:43 As plankton blooms mound
00:46:46 more opportunists gather.
00:46:49 Larvae may end their journey
00:46:50 on the stinging tentacles
00:46:54 ...or engulfed by the ballooning
00:48:01 Up here, invisible, could be the
00:48:07 Out of the countless millions
00:48:08 dispersed only a few will
00:48:14 Far fewer will evade
00:48:17 and find a safe place to settle.
00:48:26 But despite incredible odds
00:48:29 the survival of just one coral
00:48:41 They cross the trackless oceans,
00:48:43 minute in size,
00:48:50 Time will see
00:48:55 Even the perilous flanks of an
00:49:00 Having crossed ocean wastes as
00:49:05 coral larvae settle to found a reef.
00:49:11 Its volcanic support will
00:49:15 a reef outpost will build
00:49:19 gathering the rare larval voyagers
00:49:23 Each new atoll is
00:49:27 In this way corals have marched
00:49:29 through time and
00:49:33 They have established collections
00:49:35 of living art in the galleries
00:50:27 Reefs are portrayed as
00:50:28 'fragile ecosystems' with
00:50:32 and yet they're robust enough to
00:50:34 have survived millions of years
00:50:36 of fierce competition and
00:50:52 They're exquisite,
00:50:54 but they're also dynamic and
00:50:58 They've adopted mass spawning
00:51:00 and dispersal as their incredible
00:51:04 change and immobility.
00:51:09 The architects of the mighty atolls
00:51:11 and the Great Barrier Reef are
00:51:18 The limestone fortresses they build
00:51:21 are monuments to the evolutionary