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Just 50 years ago,
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we finally ventured to the Moon.
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For the very first time,
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we looked back at our own planet.
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Since then, the human population
has more than doubled.
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This series will celebrate
the natural wonders that remain
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and reveal what we must preserve
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to ensure people and nature thrive.
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Dolphins...
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panicking.
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They're being hunted
by false killer whales.
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Dolphins are faster in short bursts.
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But their hunters have stamina.
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Just as the killer whales close in,
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the dolphins make a sudden turn
to evade their predators.
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These extraordinary events
are taking place far from land,
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where few of us ever venture.
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This is the ocean
beyond the boundary of any country...
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largely ungoverned, wild, and lawless.
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Nothing symbolizes
our relationship with the high seas
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better than the blue whale.
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Weighing 200 tons and 30 meters long,
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these are the largest animals
ever to have existed.
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Yet much of their lives
is still a mystery to us.
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Blue whales live far out to sea,
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roaming every ocean
from the tropics to the poles.
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We have only recently discovered
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a few special places
where they come close to shore.
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The Gulf of California,
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on Mexico's Pacific coast.
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This is a sanctuary for blue whales.
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Meet the world's biggest newborn...
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a baby blue.
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Just a month old,
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she's already eight meters long
and weighs six tons.
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Her mother shelters her
with a protective fin.
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They caress one another,
cherishing their close bond.
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These are the most intimate images
ever captured
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of a blue whale mother and her calf.
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This female will give birth
only once every two or three years,
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so each baby blue is extremely precious.
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The calf will grow three tons a month.
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Once, there were
more than 300,000 blue whales,
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but last century,
they were hunted relentlessly,
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and only a few thousand survived.
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Blue whales are now protected,
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and their numbers are slowly increasing.
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Soon, this calf will leave
these sheltered waters
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to roam the high seas.
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We once thought that the high seas
were simply too vast for us to damage,
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but we now know that her ocean home
is under threat as never before.
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Out here in the big blue,
there remain a few pristine places
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to remind us
how rich the oceans can still be.
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Spinner dolphins.
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In the Pacific, off the coast
of Costa Rica, Central America,
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they are starting to gather
in great numbers.
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Spinners live in pods,
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groups of individuals
linked by complex social relationships.
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The dolphins constantly touch
and talk with one another,
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using a language of clicks and whistles.
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They are shadowed by yellowfin tuna.
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The tuna rely on the dolphins
to find food.
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Everyone is searching for the same prey...
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lantern fish...
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the most numerous fish on the planet.
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No longer than your finger,
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lantern fish spend most of their time
hiding in the deep.
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So, despite their astounding abundance,
we don't fish for them.
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They are one of the few fish
that still thrives.
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As they close in on their prey,
the dolphin pod gets bigger and bigger.
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This pod could be 10,000 strong.
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For every one at the surface,
20 swim below.
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Using echolocation, a type of sonar,
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the dolphins detect lantern fish
in the depths
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and drive them to the surface.
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They patrol the underside of the shoal
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to stop their prey
escaping back to the deep.
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Once the dolphins have had their fill,
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there's still plenty more
for other predators.
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Mobula rays swoop in.
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To maximize their catch,
the rays attack in formation.
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A wall of mouths scooping up their prey.
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Because we don't fish for them,
lantern fish and their predators thrive.
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All these hunters have barely made a dent
in the great shoal.
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Most life in the open ocean
is concentrated in a thin surface layer,
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where the power of the sun
has its greatest effect.
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These sunlit shallows
are fertilized in a surprising way.
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As the dolphins produce waste,
they play a vital role,
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recycling nutrients from the deep
up to the surface.
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This marine manure
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helps to fuel the basis
of all life in the open ocean.
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Phytoplankton...
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microscopic drifting plants.
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They combine nutrients in seawater
with energy from the sun
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to create the very foundation
of every food chain out here.
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So all animals, from the smallest fish
to the largest whale,
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ultimately depend
on these tiny plants for food.
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And in turn, the phytoplankton
benefits from the nutrients
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produced by these animals.
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Crucially, phytoplankton also produce
half the oxygen in the air we breathe.
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So, no matter where you live,
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you can thank
these exquisite little plants
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for every other breath you take.
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In ideal conditions,
they can bloom to such an extent
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that great swathes of the ocean
turn green.
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Surprisingly, phytoplankton
also play a vital role in cloud formation.
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Moisture evaporating from the ocean
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condenses around
tiny particles created by the plankton.
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These droplets combine
to grow into colossal clouds.
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They can rise 20 kilometers
into the atmosphere.
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These oceanic clouds
reflect the sun's energy back into space,
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helping to protect the Earth
from rising temperatures.
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Not only do the oceans
produce half the oxygen we breathe,
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they also drive the weather and climate,
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transporting life-giving fresh water
around the world.
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The high seas
are the life-support system of our planet.
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They have such power
simply because they're so vast.
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The oceans cover two-thirds of the globe,
and that's just the surface.
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They're also immensely deep.
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We can only journey
to this unexplored space
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in special submarines
that can withstand the crushing pressure.
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The average depth of the oceans
is nearly four kilometers,
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and the deepest point more than ten.
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The deep makes up 95 percent
of all the space available for life.
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This alien world
is home to weird and mysterious creatures.
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Few are stranger than this one.
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For years, we only knew they existed
from the occasional one washed ashore.
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They have hardly ever been seen alive.
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An oarfish.
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Ten meters long.
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Hanging vertically
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and using rhythmic waves
along their dorsal fin,
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oarfish commute easily
between the surface and the depths.
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Below 200 meters, there's not enough light
for plants to grow,
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so deep-sea animals depend on
food sinking down from the surface...
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marine snow.
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A crown jellyfish
drifts with tentacles outstretched
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to ensnare pray.
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They live in every ocean,
to depths of seven kilometers.
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The deep is so vast that these could be
the most abundant of all jellyfish.
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We used to think
the deep supported little life,
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but scientists now believe
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there are ten times more animals
living here than previously thought.
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So, there must be many
yet to be discovered.
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This deep-water crustacean, Cystisoma,
is as clear as glass.
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It hides in plain sight.
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In this twilight zone,
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invisibility can be the difference
between finding a meal and being one.
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Its huge eyes strain to see in the gloom.
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No light penetrates
below a thousand meters.
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In this darkness,
animals create their own light...
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bioluminescence.
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A glowing lure entices victims
into this dragonfish's terrifying teeth.
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On most expeditions down here,
we are surprised by something new.
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A deep-sea anglerfish.
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Her extraordinary array of sensors
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will detect even the faintest movement
by prey tempted to her lure.
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Here, in the deep midwater,
predators play a patient game.
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Eventually, we reach the bottom,
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nearly a thousand meters down.
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The deep-sea plains
cover more than half the Earth's surface,
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and yet we know more
about the surface of the Moon.
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Chimaera,
an ancient relative of the shark,
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up to two meters long.
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Few species of this size
can make a living on the barren seafloor.
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Moving slowly to conserve energy,
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they use special electrical sensors
around their mouths
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to search for scarce prey
buried in the sediment.
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Rocky outcrops rising from the seafloor
can be oases in this desert.
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This ragged-tooth shark
has come here for good reason.
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Five hundred meters down
off the coast of Florida,
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a rare hot spot of life.
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Lophelia, deep-sea coral reefs.
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We used to think that corals
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were only found
in the warm, sunny shallows.
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But, astonishingly, deep-sea reefs
cover a greater area of the seafloor
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than their shallow-water relatives.
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These underwater forests
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provide shelter and food
for a rich community of marine life.
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They're also vital nurseries
for many deep-sea creatures.
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The corals are made up
of many anemone-like individuals,
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polyps that live in colonies
connected by a hard skeleton.
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The polyps
have stinging cells in their tentacles
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to snare passing prey,
their only source of food.
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But they don't always
get to keep their catch.
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A bristle worm has set up home
within the coral.
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It checks the polyps
for a freshly caught morsel...
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and steals it from the coral.
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But this theft
is actually a protection racket.
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Urchins attack and eat the corals.
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Time for payback.
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The urchin may have protective spines,
but the worm has a shocking weapon,
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and goes on the attack.
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The urchin has been seen off,
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and the worm has saved its home.
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Like most deep-sea animals,
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these corals grow extremely slowly.
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Some reefs may be 40,000 years old.
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Despite being so far beneath the surface,
these corals are still within our reach.
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Deep-sea fishing nets
dragged across the seafloor
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reduce the fragile reefs to rubble.
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Half of all deep-sea corals
have already been destroyed.
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It will take centuries
for these communities to recover.
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Beyond the boundary of any one country,
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the high seas
are wild and barely protected.
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Wildest of all, the Southern Ocean,
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home of the albatross.
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Albatross live solitary lives
far out to sea.
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They can travel
hundreds of kilometers a day,
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often for weeks at a time,
searching for food.
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A dead sea lion is a rare opportunity.
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Giant petrels are the first to arrive.
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They use their powerful beaks
to rip the carcass open.
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Known as sea vultures,
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they are the top scavenger
in Antarctic waters.
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Black-browed albatross
have an extraordinary sense of smell
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and can follow a scent
from 20 kilometers away.
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The black-browed
must grab mouthfuls when they can.
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They are bullied
by the more aggressive giant petrels.
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Wilson's petrels are too small to compete
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and pick off scraps
from the edge of the frenzy.
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These delicate little petrels
are the most numerous of all seabirds
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because they're found in every ocean.
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It's only when
these normally solitary birds
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gather like this
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that we can appreciate the wealth of life
supported by the high seas.
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A wandering albatross is last to arrive.
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It dwarfs the other birds
and uses its great size
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and three-meter wingspan to dominate.
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Even the giant petrels back off.
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The wanderer finally gets its share.
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In recent years,
albatross and other seabirds
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have been in decline.
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Their need to travel great distances
exposes them
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to the dangers of a poorly regulated
and overexploited ocean.
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It's a problem
for all hunters of the high seas.
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These giants cross entire oceans
in their search for food.
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They can grow over three meters long
and weigh half a ton.
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Bluefin tuna.
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They're streamlined to perfection
and built for speed.
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They hunt in great packs, hundreds strong.
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The target: a school of anchovies.
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They gently corral the anchovies
into a tight ball at the surface,
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careful not to cause panic.
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And then they attack.
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This is a highly coordinated hunt.
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00:35:42,598 --> 00:35:44,267
The tuna take turns,
248
00:35:44,350 --> 00:35:47,979
striking from the same direction
to keep the anchovies on the run.
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00:35:56,612 --> 00:36:01,367
After a mouthful, each bluefin peels off
to take its place at the rear.
250
00:36:02,660 --> 00:36:05,705
Wave after wave continues the assault.
251
00:36:21,637 --> 00:36:23,931
With their power and devastating pace,
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00:36:24,015 --> 00:36:28,436
bluefin tuna are one of the ocean's
most impressive hunters.
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00:36:39,780 --> 00:36:43,409
They are also
the most prized fish in the sea.
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00:36:46,120 --> 00:36:50,541
So valuable
that a single bluefin can sell in Japan
255
00:36:50,625 --> 00:36:52,668
for over a million dollars.
256
00:36:55,379 --> 00:36:57,548
So, perhaps it's inevitable
257
00:36:57,632 --> 00:37:00,760
that they have been fished
almost to extinction.
258
00:37:05,848 --> 00:37:09,477
Bluefin tuna
are not the only ones in peril.
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00:37:13,689 --> 00:37:16,025
Decades of unsustainable fishing
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00:37:16,108 --> 00:37:19,237
have left many fish stocks
in serious decline.
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00:37:22,865 --> 00:37:25,076
A third have collapsed altogether.
262
00:37:29,121 --> 00:37:32,291
Plastic pollution
is a grave issue for our oceans,
263
00:37:33,125 --> 00:37:37,213
but industrial overfishing
is far more dangerous.
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00:37:39,757 --> 00:37:43,344
If we continue to harvest the seas
in this way,
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00:37:43,427 --> 00:37:46,013
it's not just fisheries
that will collapse.
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00:37:48,683 --> 00:37:51,978
The whole ocean system could follow.
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00:37:58,484 --> 00:38:02,280
One hundred million sharks
are killed every year,
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00:38:04,031 --> 00:38:06,409
just to make shark fin soup.
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00:38:16,419 --> 00:38:21,090
Ninety percent of all large ocean hunters
have disappeared.
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00:38:25,845 --> 00:38:31,058
Without them at the top of the food chain,
the whole community of marine life
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00:38:31,642 --> 00:38:35,271
is declining
and changing beyond recognition.
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00:38:56,667 --> 00:39:00,755
Squid are increasingly replacing fish.
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00:39:07,720 --> 00:39:12,475
We have severely depleted
both their predators and competitors,
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00:39:13,642 --> 00:39:15,978
so squid are taking over,
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00:39:19,231 --> 00:39:23,569
an indication
of a serious imbalance in the oceans.
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00:39:29,700 --> 00:39:33,371
Squid breed quickly
and have lots of fast-growing young,
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00:39:35,164 --> 00:39:40,086
so they can rapidly exploit the gaps
left by the fish that we have harvested.
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00:39:42,213 --> 00:39:44,673
They lay their eggs in cases
on the seafloor.
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00:39:44,757 --> 00:39:49,303
The young develop even faster
in these warm, shallow waters.
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00:39:52,556 --> 00:39:55,726
With such drastic changes
in the marine menu,
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00:39:55,810 --> 00:39:58,270
predators are having to adapt.
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00:40:02,733 --> 00:40:06,320
Sea lions prefer to eat
more energy-rich prey,
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00:40:06,404 --> 00:40:08,489
like anchovies and sardines,
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00:40:09,281 --> 00:40:11,367
but with these in short supply,
285
00:40:11,450 --> 00:40:14,662
they're forced to rely more
on a diet of squid.
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00:40:19,583 --> 00:40:23,170
We, too, will be forced to change
the seafood we eat
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00:40:23,254 --> 00:40:25,673
if we continue to fish as we do.
288
00:40:29,802 --> 00:40:33,264
But if we harvest the oceans
in a sustainable way,
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00:40:34,390 --> 00:40:36,684
they can be marvelously productive
290
00:40:37,685 --> 00:40:40,688
and will provide us
with an abundance of food.
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00:40:46,819 --> 00:40:49,572
There are already signs
that the ocean has the power
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00:40:49,655 --> 00:40:52,032
to recover astonishingly quickly.
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00:41:01,959 --> 00:41:03,377
Humpback whales.
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00:41:11,218 --> 00:41:13,262
They live in every ocean,
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00:41:13,345 --> 00:41:16,849
traveling the high seas,
from their polar feeding grounds
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00:41:16,932 --> 00:41:18,893
to the tropics, where they breed.
297
00:41:22,897 --> 00:41:26,567
Yet whales have not always enjoyed
such freedom.
298
00:41:29,695 --> 00:41:33,073
Once, there were
more than a hundred thousand humpbacks
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00:41:33,157 --> 00:41:34,157
in the oceans,
300
00:41:35,117 --> 00:41:39,079
but last century,
they were hunted to near extinction.
301
00:41:44,793 --> 00:41:48,172
Just a few thousand
survived the onslaught.
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00:41:56,847 --> 00:41:58,766
A huge public outcry
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00:41:59,183 --> 00:42:04,146
finally led to a ban
on commercial whaling in 1986.
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00:42:07,733 --> 00:42:12,613
Since then, the number of humpback whales
has been steadily increasing.
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00:42:18,619 --> 00:42:21,497
They're returning
to their ancestral feeding grounds,
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00:42:21,580 --> 00:42:24,083
like these off the coast of South Africa.
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00:42:33,467 --> 00:42:38,055
They are gathering to take advantage
of a seasonal abundance of krill,
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00:42:38,138 --> 00:42:40,182
tiny shrimp-like crustaceans.
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00:42:52,778 --> 00:42:55,489
The whales take in
great mouthfuls of water,
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00:42:56,240 --> 00:42:59,243
trapping the krill
on sieves of hairy bristles
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00:42:59,326 --> 00:43:00,703
that line their jaws.
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00:43:22,516 --> 00:43:25,811
Each whale can eat over a ton a day.
313
00:43:56,759 --> 00:44:01,722
With food so plentiful,
fur seals come to claim their share.
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00:44:24,828 --> 00:44:29,833
These extraordinary scenes
were unimaginable just a few years ago.
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00:44:45,891 --> 00:44:49,311
They form super-groups, hundreds strong.
316
00:45:11,709 --> 00:45:17,005
This is the greatest gathering of whales
seen for a century.
317
00:45:37,192 --> 00:45:41,572
Whales recycle nutrients
that enrich surface waters,
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00:45:42,114 --> 00:45:44,700
which fuel the growth of phytoplankton,
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00:45:45,617 --> 00:45:50,581
and they, in turn, feed krill
in a perfect self-sustaining cycle.
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00:45:53,542 --> 00:45:57,045
We now know that a healthy community
of great hunters,
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00:45:57,129 --> 00:46:00,174
whales, dolphins, tuna, and sharks,
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00:46:01,091 --> 00:46:04,094
is essential
for a fully-functioning ocean.
323
00:46:07,431 --> 00:46:11,894
And a functioning ocean
is vital to the health of our planet
324
00:46:12,519 --> 00:46:13,771
and humanity.
325
00:46:18,275 --> 00:46:20,527
In a remarkable recovery,
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00:46:20,611 --> 00:46:24,448
humpback whales have almost returned
to their original numbers.
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00:46:27,493 --> 00:46:29,495
But during that time,
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00:46:29,578 --> 00:46:34,917
we have done more harm to the oceans
than ever before in human history.
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00:46:44,301 --> 00:46:47,346
Only with global cooperation
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00:46:47,429 --> 00:46:51,183
will our oceans
recover and thrive once again.
331
00:46:55,145 --> 00:46:58,607
We saved the whales
by international agreement.
332
00:47:01,026 --> 00:47:05,072
Now, it is time to save our oceans.
333
00:47:17,960 --> 00:47:22,798
Please visit ourplanet.com
to discover what we need to do now
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00:47:22,881 --> 00:47:24,883
to protect the high seas.
335
00:47:27,344 --> 00:47:33,183
♪ I can hear the whole world
Singing together ♪
336
00:47:35,894 --> 00:47:41,775
♪ I can hear the whole world
Say it's now or never ♪
337
00:47:44,611 --> 00:47:48,907
♪ 'Cause it's not too late
If we change our ways ♪
338
00:47:48,991 --> 00:47:52,786
♪ And connect the dots to our problems ♪
339
00:47:52,870 --> 00:47:58,917
♪ I can hear the whole world
Say we're in this together ♪
340
00:47:59,001 --> 00:48:00,794
♪ We're in this together ♪