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Much of our planet
still remains unexplored...
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00:00:50,900 --> 00:00:54,160
..for most of it is covered
by water.
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00:00:56,900 --> 00:01:01,600
Every journey below the surface
can reveal something extraordinary.
4
00:01:05,120 --> 00:01:10,720
More than a thousand new species
are discovered here every year.
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00:01:25,000 --> 00:01:32,960
The ocean is home to 80%
of all animal life on Planet Earth.
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00:01:40,760 --> 00:01:45,960
But today,
thriving in this varied world
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00:01:45,960 --> 00:01:50,720
sometimes demands
the most surprising behaviour.
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00:02:11,720 --> 00:02:15,160
The shallow seas of the tropics.
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00:02:17,960 --> 00:02:21,280
This may look like a paradise...
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00:02:24,400 --> 00:02:28,840
..but beneath the surface,
it is an arena
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00:02:28,840 --> 00:02:32,200
for constant
life-and-death struggles,
12
00:02:32,200 --> 00:02:35,720
where not everything
is quite as it seems.
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00:02:45,240 --> 00:02:48,840
A predatory lionfish...
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00:02:51,720 --> 00:02:54,920
..on the hunt for shrimp
and small fish.
15
00:03:03,840 --> 00:03:08,080
With so many places
for its prey to hide,
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00:03:08,080 --> 00:03:11,120
the lionfish has to be patient.
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00:03:17,920 --> 00:03:21,320
This shrimp appears tempting.
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00:03:22,880 --> 00:03:25,440
As the lion-fish closes in,
19
00:03:25,440 --> 00:03:30,200
it fans out its fins
to disorientate its prey.
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00:03:42,840 --> 00:03:45,760
The hunter becomes the hunted.
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00:03:52,240 --> 00:03:54,760
Tricked by one
of the shallow sea's
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00:03:54,760 --> 00:03:57,320
most extraordinary predators...
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00:04:01,280 --> 00:04:04,080
..a clown frogfish!
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00:04:06,640 --> 00:04:10,200
On its head, it carries
a fishing rod -
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00:04:10,200 --> 00:04:12,560
a modified dorsal fin,
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00:04:12,560 --> 00:04:17,400
baited with a lure -
easily mistaken for a shrimp.
27
00:04:27,880 --> 00:04:30,560
But, when the fish stop biting,
28
00:04:30,560 --> 00:04:33,200
it's time to pack the rod away
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00:04:33,200 --> 00:04:35,440
and move on.
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00:04:38,560 --> 00:04:44,080
And, for a frogfish,
that takes time.
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00:04:54,840 --> 00:04:59,280
Rather than swim, frogfish walk!
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00:05:01,240 --> 00:05:04,920
Its fins have, in effect,
become feet.
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00:05:14,480 --> 00:05:16,600
It may not look pretty,
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00:05:16,600 --> 00:05:23,200
but what appears to be coral living
on its skin is actually camouflage.
35
00:05:36,840 --> 00:05:39,480
As every good angler knows,
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00:05:39,480 --> 00:05:42,640
picking the right spot is important.
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00:05:48,040 --> 00:05:51,560
Jigging the rod sends out
pressure waves
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00:05:51,560 --> 00:05:54,680
to attract the attention
of possible prey.
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00:06:02,960 --> 00:06:06,000
These dragonets
are certainly interested.
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00:06:18,680 --> 00:06:21,080
Almost there.
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00:06:35,120 --> 00:06:37,840
Hook, line, and sinker.
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00:06:49,920 --> 00:06:53,040
Like all shallow seas,
the cold waters
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00:06:53,040 --> 00:06:56,040
off the coast of North America,
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00:06:56,040 --> 00:06:59,760
benefit from the intensity
of the sunshine.
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00:07:06,840 --> 00:07:08,880
Here, that fuels
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00:07:08,880 --> 00:07:12,360
one of the fastest-growing
organisms on the planet...
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00:07:14,360 --> 00:07:16,320
..giant kelp.
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00:07:19,080 --> 00:07:22,840
Towering forests
can eventually reach the height
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00:07:22,840 --> 00:07:25,240
of a 12-storey building.
50
00:07:38,240 --> 00:07:43,240
These forests are nurseries
for young horn sharks.
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00:07:46,760 --> 00:07:48,920
As the sun begins to set,
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00:07:48,920 --> 00:07:52,080
they leave their daytime shelter
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00:07:52,080 --> 00:07:57,640
and set off into the heart
of the kelp forest to find food.
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00:08:07,880 --> 00:08:09,880
Barely half a metre long,
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00:08:09,880 --> 00:08:13,640
this little shark
is extremely vulnerable.
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00:08:20,400 --> 00:08:23,480
There are monsters here.
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00:08:23,480 --> 00:08:26,280
A giant sea bass -
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00:08:26,280 --> 00:08:29,240
weighing over 200kg...
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00:08:32,440 --> 00:08:36,120
..and wolf-eels, with big teeth
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00:08:36,120 --> 00:08:39,360
that can crush
little red sea urchins.
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00:08:41,800 --> 00:08:45,440
But the biggest danger
comes from other sharks -
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00:08:49,600 --> 00:08:52,760
houndsharks...
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00:08:56,320 --> 00:09:00,080
..and huge broadnose sevengills.
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00:09:11,800 --> 00:09:16,280
In this forest,
it pays to keep a low profile.
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00:09:49,800 --> 00:09:52,240
An angel shark...
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00:09:55,640 --> 00:09:59,680
..one of the most deadly sharks
in the kelp forest,
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00:09:59,680 --> 00:10:03,200
and certainly
the best camouflaged.
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00:10:13,880 --> 00:10:18,720
An angel shark
will lie in wait for days...
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00:10:28,200 --> 00:10:34,000
..but this one has already attracted
too much attention.
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00:10:40,600 --> 00:10:43,200
It's not welcome here.
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00:10:50,040 --> 00:10:52,600
Now, the coast is clear.
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00:11:00,600 --> 00:11:04,280
But angel sharks hunt
around the clock.
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00:11:14,520 --> 00:11:18,320
Openings for breathing,
called spiracles,
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00:11:18,320 --> 00:11:21,600
blow out sand
that helps cover its body.
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00:11:28,880 --> 00:11:31,680
The trap is set.
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00:11:43,160 --> 00:11:49,240
Staying close to the seabed is
a good way to avoid most predators.
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00:12:38,720 --> 00:12:42,200
Faster than the blink of an eye.
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00:12:45,520 --> 00:12:48,080
But it's not over yet.
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00:13:00,040 --> 00:13:04,040
Horn sharks have a secret weapon.
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00:13:08,880 --> 00:13:13,080
Sharp spikes keep them very much
off the menu for most.
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00:13:19,640 --> 00:13:25,400
So, this young horn shark
can hunt in safety...
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00:13:27,320 --> 00:13:29,360
..for now.
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00:13:56,000 --> 00:14:00,920
Violent winter storms
batter these kelp forests.
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00:14:08,240 --> 00:14:11,320
The plants can be ripped
from the seafloor...
85
00:14:14,320 --> 00:14:17,880
..and carried away far out to sea.
86
00:14:29,920 --> 00:14:35,160
The open ocean
is a vast, featureless desert.
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00:14:39,080 --> 00:14:43,720
Even a small piece of drifting kelp
can become valuable.
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00:14:53,760 --> 00:14:58,680
It's just what these fish
have been searching for.
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00:15:00,520 --> 00:15:05,600
Here, shelter where eggs can be laid
unobtrusively is rare...
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00:15:07,360 --> 00:15:10,160
..so they make the most of it.
91
00:15:12,160 --> 00:15:16,360
Each female produces
up to a thousand eggs,
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00:15:16,360 --> 00:15:19,600
and the males rush in
to fertilise them.
93
00:15:30,280 --> 00:15:35,520
All this activity attracts
the attention of blue sharks.
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00:15:38,440 --> 00:15:41,160
They can travel thousands of miles
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00:15:41,160 --> 00:15:43,720
through the ocean
in search of food...
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00:15:48,200 --> 00:15:53,120
..and they may not have eaten
for weeks.
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00:15:53,120 --> 00:15:55,880
It seems that they're in luck.
98
00:16:03,800 --> 00:16:07,800
But these fish are no easy meal.
99
00:16:13,720 --> 00:16:16,240
They are flying fish!
100
00:17:15,320 --> 00:17:18,120
The blue shark, however,
101
00:17:18,120 --> 00:17:20,200
are not here for the fish...
102
00:17:23,200 --> 00:17:27,360
..they have come for the caviar.
103
00:17:42,040 --> 00:17:44,960
But flying fish lay so many eggs,
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00:17:44,960 --> 00:17:48,360
that the sharks' feasts
hardly make an impact.
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00:17:56,720 --> 00:18:02,160
And, in a few months' time, a new
generation will take to the skies.
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00:18:15,400 --> 00:18:20,280
Floating islands of weed
are always attractive to creatures
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00:18:20,280 --> 00:18:23,720
looking for shelter
out in the big blue.
108
00:18:25,400 --> 00:18:29,800
But, in today's ocean, they are
being replaced by something else...
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00:18:35,200 --> 00:18:37,000
..plastic.
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00:18:39,040 --> 00:18:43,640
12 million tons of it
end up in the ocean every year.
111
00:18:47,120 --> 00:18:52,560
The deadliest kind are discarded
fishing lines and nets.
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00:18:56,240 --> 00:19:01,000
Each year, it's likely over
half a million animals are ensnared
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00:19:01,000 --> 00:19:04,680
and killed by these "ghost nets."
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00:19:14,240 --> 00:19:16,680
But some animals are learning
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00:19:16,680 --> 00:19:19,720
how to take advantage
of the plastic rafts...
116
00:19:22,560 --> 00:19:27,080
..and use them for shelter,
or even as a home.
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00:19:30,120 --> 00:19:35,120
This male Columbus crab - barely
bigger than your thumb nail -
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is a castaway.
119
00:19:40,640 --> 00:19:42,280
Clinging to his net,
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00:19:42,280 --> 00:19:46,280
he may have been drifting
on ocean currents for months.
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00:19:49,320 --> 00:19:53,200
Now, fully grown,
he needs to find a partner.
122
00:19:55,600 --> 00:19:57,800
But where?
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00:20:05,360 --> 00:20:07,840
Certainly not here,
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00:20:07,840 --> 00:20:10,600
alone on the net.
125
00:20:19,400 --> 00:20:24,720
Columbus crabs are not good
swimmers, so this male is marooned.
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00:20:34,600 --> 00:20:38,120
Perhaps a passing loggerhead turtle
could be the chance
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00:20:38,120 --> 00:20:39,800
to hitch a lift.
128
00:21:30,920 --> 00:21:32,320
Made it!
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00:21:35,280 --> 00:21:39,560
But there's more than one
passenger here -
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a female Columbus crab!
131
00:21:50,400 --> 00:21:54,000
They waste no time
in getting acquainted...
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00:21:57,320 --> 00:21:59,760
..and start to mate.
133
00:22:07,560 --> 00:22:12,240
This pair may well stay together
for the rest of their lives.
134
00:22:22,120 --> 00:22:26,760
A turtle, after all,
makes an excellent home.
135
00:22:35,120 --> 00:22:40,200
In return, the crabs provide
an onboard grooming service.
136
00:23:11,080 --> 00:23:16,440
Finding a partner in the vast ocean
is not easy.
137
00:23:23,040 --> 00:23:26,920
Dawn in the Sea of Cortez...
138
00:23:50,360 --> 00:23:52,840
..Mobula rays.
139
00:24:13,080 --> 00:24:16,840
They're gathering here,
most likely to breed.
140
00:24:21,800 --> 00:24:24,800
No-one is sure why they leap,
141
00:24:24,800 --> 00:24:29,360
but the loud splashes
certainly seem to attract more rays.
142
00:24:33,560 --> 00:24:37,800
Other creatures, however,
are also listening.
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00:24:48,200 --> 00:24:51,520
Orca have heard the splashes.
144
00:25:13,080 --> 00:25:17,360
This female specialises
in hunting rays.
145
00:25:24,640 --> 00:25:28,480
But today, she is teaching
two youngsters
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00:25:28,480 --> 00:25:32,760
the finer points
of Mobula ray hunting.
147
00:25:44,480 --> 00:25:48,880
The rays are fast
and can outmanoeuvre an orca.
148
00:25:57,120 --> 00:26:01,880
She knows she needs to herd
the prey into a tight group...
149
00:26:06,880 --> 00:26:10,400
..but she can't do that on her own.
150
00:26:10,400 --> 00:26:14,360
It will take teamwork,
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00:26:14,360 --> 00:26:17,040
and that is today's lesson.
152
00:26:24,400 --> 00:26:28,440
The young orca
are quick to catch on.
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00:26:32,920 --> 00:26:36,200
The rays are surrounded.
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00:26:40,040 --> 00:26:42,320
They dive...
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00:26:45,240 --> 00:26:50,360
..only to be forced back up again
by the experienced female.
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00:26:54,120 --> 00:26:59,480
And now, with the exhausted rays
trapped against the surface,
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00:26:59,480 --> 00:27:01,760
she attacks...
158
00:27:14,880 --> 00:27:18,720
..and the young ones
follow her lead.
159
00:27:27,880 --> 00:27:32,560
This family are the only orca
known to hunt rays like this...
160
00:27:34,160 --> 00:27:37,080
..and they are lethally efficient.
161
00:27:42,040 --> 00:27:46,400
But it appears that school
is over for today.
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00:27:48,400 --> 00:27:51,080
For a few battle-scarred survivors,
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00:27:51,080 --> 00:27:53,560
it's a lucky reprieve.
164
00:28:04,120 --> 00:28:08,960
With the orca gone, the rays
can resume their courtship...
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00:28:17,320 --> 00:28:21,120
..and they do so
in astounding numbers.
166
00:28:30,320 --> 00:28:34,480
Tens of thousands of rays
in a single shoal.
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00:28:49,880 --> 00:28:53,840
Vast areas of our ocean
are yet to be explored.
168
00:28:55,880 --> 00:29:00,160
The least known parts of it
are its great depths.
169
00:29:06,680 --> 00:29:10,960
Only highly-specialised vessels
can take you there.
170
00:29:16,320 --> 00:29:20,720
As you descend,
the sunlight rapidly fades.
171
00:29:27,080 --> 00:29:31,800
200m down,
you enter the twilight zone...
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00:29:39,040 --> 00:29:45,240
..an alien world, inhabited
by creatures beyond imagination.
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00:30:06,960 --> 00:30:12,880
A siphonophore - with a cloak
of lethal stinging tentacles.
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00:30:26,000 --> 00:30:30,040
Siphonophores repeatedly
clone themselves
175
00:30:30,040 --> 00:30:33,120
and so grow to immense lengths.
176
00:30:37,680 --> 00:30:43,520
This one measures 45m and is
the longest animal ever recorded.
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00:30:48,280 --> 00:30:50,560
With such deadly predators around,
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00:30:50,560 --> 00:30:54,240
creatures here go
to great lengths to hide.
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00:31:04,840 --> 00:31:07,320
A glass squid...
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00:31:09,040 --> 00:31:11,840
..completely transparent,
181
00:31:11,840 --> 00:31:14,400
except for its eyes...
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00:31:17,920 --> 00:31:21,240
..and stomach,
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00:31:21,240 --> 00:31:25,080
so it is extremely difficult
to find in the gloom.
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00:31:46,200 --> 00:31:49,160
Below 1,000m,
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00:31:49,160 --> 00:31:52,880
all traces of sunlight
have disappeared.
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00:31:55,040 --> 00:31:58,680
This is the midnight zone.
187
00:32:03,960 --> 00:32:08,520
Catching food in the perpetual
darkness is not easy.
188
00:32:29,440 --> 00:32:31,840
A gulper eel.
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00:32:39,920 --> 00:32:42,160
Its giant, extendable mouth
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00:32:42,160 --> 00:32:45,640
can engulf prey
larger than its own body.
191
00:33:09,160 --> 00:33:14,160
Two miles down,
you finally reach the ocean floor.
192
00:33:19,840 --> 00:33:23,280
We know more
about the surface of Mars.
193
00:33:28,720 --> 00:33:34,800
The pressure of the water is 300
times greater than at the surface...
194
00:33:34,800 --> 00:33:37,240
..and it's freezing cold.
195
00:33:39,600 --> 00:33:44,560
Yet, amazingly,
there are animals living here.
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00:33:49,920 --> 00:33:52,800
Muusoctopus robustus,
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00:33:52,800 --> 00:33:56,080
nicknamed the pearl octopus.
198
00:33:59,120 --> 00:34:02,800
Breeding, in these
extreme conditions poses
199
00:34:02,800 --> 00:34:05,800
a particular problem
for these animals.
200
00:34:08,920 --> 00:34:11,240
At these low temperatures,
201
00:34:11,240 --> 00:34:15,840
this female's eggs could take
over ten years to develop.
202
00:34:25,000 --> 00:34:29,200
So she travels
to a very special place.
203
00:34:43,440 --> 00:34:48,760
This is the largest known
gathering of octopus in the world.
204
00:34:58,640 --> 00:35:02,720
She joins 20,000 other females...
205
00:35:04,640 --> 00:35:07,520
..all here to lay their eggs.
206
00:35:14,040 --> 00:35:17,640
Water, heated deep
in the Earth's crust,
207
00:35:17,640 --> 00:35:20,880
rises through cracks
in the seabed...
208
00:35:22,800 --> 00:35:28,040
..raising the temperature
to as much as 10 degrees Celsius.
209
00:35:29,440 --> 00:35:32,240
A deep-sea thermal spa!
210
00:35:37,280 --> 00:35:40,280
This warmth significantly speeds up
211
00:35:40,280 --> 00:35:43,560
the development of their eggs.
212
00:35:43,560 --> 00:35:47,560
Even so, they will still take
nearly two years to hatch.
213
00:35:49,800 --> 00:35:52,240
Once a female is settled,
214
00:35:52,240 --> 00:35:54,760
she won't move from her spot...
215
00:35:56,280 --> 00:35:58,800
..not even to feed.
216
00:36:10,360 --> 00:36:14,400
She will constantly tend
to her brood -
217
00:36:14,400 --> 00:36:17,280
keeping them clean,
218
00:36:17,280 --> 00:36:19,400
and oxygenating them
219
00:36:19,400 --> 00:36:22,000
with jets of water.
220
00:36:25,720 --> 00:36:30,800
Pearl octopus mothers must surely be
amongst the most devoted.
221
00:36:48,120 --> 00:36:53,560
After almost two years,
the ordeal take its toll.
222
00:37:00,520 --> 00:37:03,320
But the vigil is almost over.
223
00:38:02,160 --> 00:38:06,480
The last of the brood
are gently encouraged to leave.
224
00:38:14,440 --> 00:38:17,440
But this will be a final act.
225
00:38:19,320 --> 00:38:25,560
Like all the mothers here, this
octopus is starved and exhausted.
226
00:38:28,680 --> 00:38:31,640
Her life will soon be over.
227
00:38:49,720 --> 00:38:53,400
But this devotion means
that her offspring are among
228
00:38:53,400 --> 00:38:58,240
the largest and most developed
of any octopus
229
00:38:58,240 --> 00:39:00,920
and have the best chance of survival
230
00:39:00,920 --> 00:39:03,720
in the demanding world of the deep.
231
00:39:20,160 --> 00:39:24,440
We're finding more of these
strange hot springs every year.
232
00:39:35,400 --> 00:39:39,280
In some places,
they can be astonishingly violent.
233
00:39:40,800 --> 00:39:45,560
Super-heated water -
hot enough to melt lead -
234
00:39:45,560 --> 00:39:48,120
spouts from the seafloor.
235
00:39:49,760 --> 00:39:52,240
Dissolved minerals
condense around them
236
00:39:52,240 --> 00:39:57,200
to form towering chimneys,
known as hydrothermal vents.
237
00:40:01,640 --> 00:40:05,520
They are home to unique
communities of animals
238
00:40:05,520 --> 00:40:09,280
that all rely on the nutrients
in the scalding water.
239
00:40:19,280 --> 00:40:23,120
Some suggest that vents
like these could be the places
240
00:40:23,120 --> 00:40:27,280
where life on Earth first began
four billion years ago.
241
00:40:35,360 --> 00:40:38,400
And there is now evidence
of hydrothermal vents
242
00:40:38,400 --> 00:40:41,480
on the moons of Jupiter and Saturn.
243
00:40:43,400 --> 00:40:46,160
Could they too be supporting life?
244
00:40:50,880 --> 00:40:55,120
Here on Earth,
the influence of these vents
245
00:40:55,120 --> 00:40:58,080
extends far beyond their chimneys.
246
00:40:59,800 --> 00:41:03,120
The essential nutrients
carried in these plumes
247
00:41:03,120 --> 00:41:08,000
can rise all the way to the surface
two miles above.
248
00:41:13,600 --> 00:41:18,320
Here, they stimulate the rapid
growth of tiny marine plants...
249
00:41:18,320 --> 00:41:21,080
..on an astronomic scale.
250
00:41:27,760 --> 00:41:31,280
This phytoplankton is so abundant
251
00:41:31,280 --> 00:41:35,520
that it produces half
of all the oxygen on Earth.
252
00:41:53,640 --> 00:41:58,200
It's also food for a host
of minute animals -
253
00:41:59,680 --> 00:42:02,000
zooplankton.
254
00:42:03,840 --> 00:42:07,520
Together, they are the basis
of the food chains
255
00:42:07,520 --> 00:42:10,600
that sustain
nearly all life in the ocean.
256
00:42:16,320 --> 00:42:19,800
In the Pacific waters
off South America,
257
00:42:19,800 --> 00:42:24,680
they feed anchovy
that gather here in billions.
258
00:42:38,040 --> 00:42:42,320
This is one of the world's
most productive ecosystems.
259
00:42:54,080 --> 00:42:57,640
These South American
sea lions are on the hunt.
260
00:43:18,040 --> 00:43:22,880
But the anchovy shoal
has already been located...
261
00:43:27,520 --> 00:43:30,840
..by the planet's
most efficient hunters.
262
00:43:34,240 --> 00:43:37,000
A net, over half a mile long,
263
00:43:37,000 --> 00:43:38,960
encircles the shoal.
264
00:43:41,960 --> 00:43:45,000
It can trap over a million fish.
265
00:43:57,000 --> 00:43:59,800
But the sea lions
aren't about to go hungry.
266
00:44:02,160 --> 00:44:05,720
They have learnt
to look for holes in the net.
267
00:44:16,280 --> 00:44:22,800
Why waste energy when food
comes to you as easily as this?!
268
00:44:29,520 --> 00:44:32,760
As more and more sea lions arrive,
269
00:44:32,760 --> 00:44:35,320
some change their tactics.
270
00:44:42,920 --> 00:44:45,880
They line up
on both sides of the net...
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00:44:47,520 --> 00:44:49,400
..and wait.
272
00:45:04,160 --> 00:45:09,040
As the net tightens, the anchovy
panic and rush for the surface.
273
00:45:15,520 --> 00:45:19,560
This is the moment the sea lions
have been waiting for.
274
00:45:33,840 --> 00:45:37,640
It's such an effective way
of hunting that the sea lions here
275
00:45:37,640 --> 00:45:40,440
are changing
their natural behaviour...
276
00:45:43,560 --> 00:45:47,360
..and are raiding the fishing nets
277
00:45:47,360 --> 00:45:49,840
in their thousands.
278
00:45:57,480 --> 00:45:59,800
With the net almost drawn in,
279
00:45:59,800 --> 00:46:03,000
the fishermen beat out
a warning signal.
280
00:46:06,440 --> 00:46:08,480
Time is up.
281
00:46:37,920 --> 00:46:41,960
In the confusion,
not everyone manages to escape.
282
00:46:50,640 --> 00:46:55,080
The trapped sea lions are in danger
of being drowned.
283
00:47:16,840 --> 00:47:20,520
Pups are separated
from their mothers.
284
00:48:24,360 --> 00:48:29,040
Then, at the last minute, the
fishermen briefly drop their net...
285
00:48:36,480 --> 00:48:39,560
..and the trapped sea lions
can escape.
286
00:48:47,840 --> 00:48:51,040
But many are not so lucky.
287
00:48:52,960 --> 00:48:57,960
Around the world, millions
of animals are accidently caught
288
00:48:57,960 --> 00:49:02,080
and die in fishing nets every day.
289
00:49:04,440 --> 00:49:08,360
And this by-catch, as it's known,
290
00:49:08,360 --> 00:49:11,680
is pushing many species
toward extinction.
291
00:49:16,560 --> 00:49:19,920
Animals have evolved
in remarkable ways
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00:49:19,920 --> 00:49:22,560
to the demands of life in the ocean.
293
00:49:27,240 --> 00:49:30,240
But can they now adapt
to the new challenge -
294
00:49:31,520 --> 00:49:34,040
living alongside us?
295
00:49:51,280 --> 00:49:54,440
The open ocean is home
to some of the largest
296
00:49:54,440 --> 00:49:57,080
and most extraordinary animals
on Earth.
297
00:49:59,480 --> 00:50:01,800
But here, off the Canary Islands,
298
00:50:01,800 --> 00:50:05,360
the Planet Earth team are searching
for one of its smaller,
299
00:50:05,360 --> 00:50:08,040
and less familiar residents.
300
00:50:08,040 --> 00:50:10,600
We're looking for a tiny creature
called a Columbus crab,
301
00:50:10,600 --> 00:50:12,760
which is only about the size
of your thumbnail,
302
00:50:12,760 --> 00:50:16,440
which live on floating objects
in the open ocean.
303
00:50:16,440 --> 00:50:19,680
Columbus crabs were once
only found on natural debris,
304
00:50:19,680 --> 00:50:21,800
like driftwood or seaweed,
305
00:50:21,800 --> 00:50:23,840
but the oceans are changing,
306
00:50:23,840 --> 00:50:26,040
and they've been forced to adapt.
307
00:50:40,520 --> 00:50:44,840
One of the most common items
they find is discarded fishing gear.
308
00:50:47,200 --> 00:50:52,440
Over a million tons is left adrift
in the ocean each year.
309
00:50:54,040 --> 00:50:56,800
And Columbus crabs are now
making their homes
310
00:50:56,800 --> 00:50:59,320
on these unnatural materials.
311
00:51:06,920 --> 00:51:10,120
Surprisingly, Columbus crabs
are thriving on this new habitat.
312
00:51:15,440 --> 00:51:20,240
But, for larger ocean creatures,
these nets can be lethal.
313
00:51:22,360 --> 00:51:25,960
Loggerhead sea turtles
are especially vulnerable.
314
00:51:29,600 --> 00:51:33,040
Many times, they are very injured
315
00:51:33,040 --> 00:51:36,880
and many times
they don't even survive.
316
00:51:36,880 --> 00:51:39,400
It's a sad situation.
317
00:51:40,880 --> 00:51:44,840
As a rule, wildlife film-makers
observe natural behaviour
318
00:51:44,840 --> 00:51:46,880
and do not interfere.
319
00:51:50,520 --> 00:51:53,880
But this is far from natural.
320
00:51:53,880 --> 00:51:57,320
The team feel they must take action.
321
00:52:06,880 --> 00:52:09,720
Sh...
322
00:52:09,720 --> 00:52:12,080
It seems that the turtle
is quite OK.
323
00:52:12,080 --> 00:52:16,680
We'll just finish to cut
the plastic and then we release it.
324
00:52:33,120 --> 00:52:35,360
It's a bittersweet moment,
325
00:52:35,360 --> 00:52:40,520
as this is one of eight turtles
they rescued whilst filming here.
326
00:52:40,520 --> 00:52:43,920
This situation is not natural,
327
00:52:43,920 --> 00:52:47,640
it's something that is
being caused by human beings.
328
00:52:49,280 --> 00:52:52,760
Sadly, the crew now face
dilemmas like this
329
00:52:52,760 --> 00:52:56,000
on many of their
filming expeditions...
330
00:52:58,080 --> 00:53:02,200
..including, when they travelled
to the Pacific coast of Chile,
331
00:53:02,200 --> 00:53:05,200
to show how sea lions
are competing for food
332
00:53:05,200 --> 00:53:07,680
with one of the biggest fisheries
on Earth.
333
00:53:12,800 --> 00:53:17,520
Expedition leader Fernando Olivares
takes the team to the fleet.
334
00:53:24,760 --> 00:53:28,400
Diving near fishing nets
is extremely dangerous,
335
00:53:28,400 --> 00:53:31,880
so the crew must ensure they have
the full cooperation
336
00:53:31,880 --> 00:53:33,840
of the fishermen.
337
00:53:58,240 --> 00:54:01,400
Pretty hazardous place to dive.
338
00:54:01,400 --> 00:54:03,680
It's just a case of trying
to keep an eye on the divers,
339
00:54:03,680 --> 00:54:06,240
but the sea lions also like
to go down and blow bubbles,
340
00:54:06,240 --> 00:54:08,000
so you'll think
you're following the divers,
341
00:54:08,000 --> 00:54:10,360
and then a sea lion will pop up.
342
00:54:15,960 --> 00:54:18,080
Taking the utmost care,
343
00:54:18,080 --> 00:54:20,200
the divers get a close-up view
344
00:54:20,200 --> 00:54:22,720
of the sheer scale of the operation.
345
00:54:28,680 --> 00:54:32,240
This one net must have
about 15 tons of fish in it
346
00:54:32,240 --> 00:54:35,320
and there's eight or nine boats
in this one little bay,
347
00:54:35,320 --> 00:54:37,040
and these are just the small boats.
348
00:54:37,040 --> 00:54:39,080
Out there, there are huge
factory ships that are taking
349
00:54:39,080 --> 00:54:41,240
even bigger catches.
350
00:54:42,440 --> 00:54:44,920
How much fish a year from just here?
351
00:54:44,920 --> 00:54:48,680
From a million tons a year
more or less.
352
00:54:56,720 --> 00:54:59,360
The catches are so vast,
353
00:54:59,360 --> 00:55:02,520
the sea lions have changed
their natural behaviour
354
00:55:02,520 --> 00:55:05,760
to collect anchovies
directly from the nets.
355
00:55:09,920 --> 00:55:11,960
But it's a risky strategy.
356
00:55:13,600 --> 00:55:17,480
The crew witnessed sea lions
caught in nets multiple times.
357
00:55:18,560 --> 00:55:21,720
Whoa, it's intense mate,
there are so many in there.
358
00:55:27,960 --> 00:55:30,520
There's a pup stuck in the net,
calling to its mother,
359
00:55:30,520 --> 00:55:33,520
and its mother's just on the outside
of the net calling back.
360
00:55:39,840 --> 00:55:42,440
That's really hard to watch.
361
00:55:47,960 --> 00:55:50,200
Oh, the pup's really panicking now.
362
00:55:52,760 --> 00:55:57,200
Sometimes, fishermen are able
to release trapped sea lions...
363
00:55:58,560 --> 00:56:00,720
..but not this time.
364
00:56:03,000 --> 00:56:05,360
The pup is in serious danger.
365
00:56:07,520 --> 00:56:11,160
Once again,
the crew decide to step in.
366
00:56:13,080 --> 00:56:16,280
Hey, he's going to go
inside of the net to save him.
367
00:56:40,000 --> 00:56:42,200
Wow.
368
00:56:46,040 --> 00:56:50,000
Nice, really nice.
369
00:56:50,000 --> 00:56:52,080
It's a relief this time...
370
00:56:54,680 --> 00:57:00,080
..but it highlights the new
realities of filming wildlife
371
00:57:00,080 --> 00:57:03,720
in today's changing ocean.
372
00:57:12,760 --> 00:57:17,080
Next time, a journey to Earth's
greatest wilderness -
373
00:57:20,760 --> 00:57:24,360
deserts and grasslands...
374
00:57:29,960 --> 00:57:33,320
..where nature puts on
its most dramatic show.
375
00:57:36,320 --> 00:57:40,440
Habitat Explorer brings animals
and their habitats to life.
376
00:57:40,440 --> 00:57:44,000
Explore this free interactive
and make origami animals.
377
00:57:44,000 --> 00:57:48,120
Go to...
378
00:57:48,120 --> 00:57:50,440
And follow the links
to the Open University.
379
00:57:50,440 --> 00:57:52,680
Or to order a free printed version,
380
00:57:52,680 --> 00:57:56,400
visit the website
or call the numbers on the screen.
30141
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