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Here in Britain and Ireland, we have
some of the richest seas in Europe.
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00:00:40,960 --> 00:00:45,520
Our varied coastline, if you include
all the many offshore islands,
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00:00:45,520 --> 00:00:48,160
is over 22,000 miles long,
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00:00:48,160 --> 00:00:52,160
and none of us live more than
70 miles away from the sea.
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00:00:53,120 --> 00:00:56,680
Yet few of us have seen the wonders
beyond the beach
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and beneath the waves.
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00:00:58,680 --> 00:01:01,040
In this episode, we will take you
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from the most southerly point of the
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United Kingdom to the furthest north,
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00:01:06,200 --> 00:01:09,720
to explain why our seas
can be so productive
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00:01:09,720 --> 00:01:13,080
and reveal the threats
that they face today.
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00:01:28,480 --> 00:01:33,280
Every winter, a warm ocean current,
the gulf stream,
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00:01:33,280 --> 00:01:36,960
drives huge storms
across the Atlantic...
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00:01:39,120 --> 00:01:44,280
...away from the Caribbean
and straight towards our shores.
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00:01:48,920 --> 00:01:54,040
There, every winter, they batter
the west coasts of our islands.
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00:02:03,320 --> 00:02:06,840
Waves with energy built up
across an entire ocean
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00:02:06,840 --> 00:02:09,280
are hurled at our coasts.
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00:02:13,640 --> 00:02:16,560
Walls of water more than
ten metres tall
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00:02:16,560 --> 00:02:19,200
crash repeatedly onto the rocks.
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00:02:32,280 --> 00:02:35,040
And as the water at depth
is churned,
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00:02:35,040 --> 00:02:38,480
it brings nutrients
up towards the surface.
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00:02:44,240 --> 00:02:48,600
These nutrients, combined
with the warmth of the gulf stream,
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00:02:48,600 --> 00:02:52,760
are the reason why marine life here proliferates
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00:02:52,760 --> 00:02:56,080
with such extraordinary richness
and variety.
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00:03:23,200 --> 00:03:25,240
Each year, in autumn,
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00:03:25,240 --> 00:03:29,480
evidence of this marine abundance
appears on land.
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13,000 grey seals haul out
on Blakeney Point in Norfolk.
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00:03:41,200 --> 00:03:44,360
It's the largest
seal colony in England.
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00:03:46,840 --> 00:03:50,680
Females, having spent most of the
year feeding in our rich waters,
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00:03:50,680 --> 00:03:53,200
are preparing to produce
their young.
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00:03:54,800 --> 00:03:57,600
Newly born,
the pups are helpless...
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00:04:00,240 --> 00:04:04,320
...and for their first few weeks,
entirely dependent on their mothers.
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00:04:06,000 --> 00:04:09,040
Seal milk is more than 50% fat...
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00:04:10,000 --> 00:04:12,960
...and the pups put on
two kilos a day.
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00:04:16,680 --> 00:04:20,440
At first, parent and pup
are inseparable.
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00:04:24,560 --> 00:04:29,480
But then, after a few days,
the youngsters start to explore.
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00:04:31,800 --> 00:04:34,760
Other females don't tolerate
the appearance
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00:04:34,760 --> 00:04:37,480
of unrelated pups on their patch.
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00:04:57,000 --> 00:05:00,040
Posing an even greater threat
than the females...
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00:05:01,000 --> 00:05:02,840
...are the males.
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00:05:10,320 --> 00:05:13,720
Three metres long
and weighing 350 kilos...
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00:05:15,520 --> 00:05:18,080
...they have come here to mate.
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00:05:21,920 --> 00:05:25,200
They know that soon after
the pups are born,
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00:05:25,200 --> 00:05:29,400
the females will become
sexually receptive once again.
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This big male tries to control
all the females
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00:05:36,600 --> 00:05:38,840
on this stretch of the beach.
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But he has a rival.
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ROARS
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00:05:54,320 --> 00:05:57,720
The big male warns off
the challenger,
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00:05:57,720 --> 00:06:00,200
but the intruder takes no notice.
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00:06:00,200 --> 00:06:02,040
ROARS
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00:06:06,840 --> 00:06:09,160
There's only one way
to settle this.
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00:06:11,160 --> 00:06:12,800
Violence.
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00:06:24,280 --> 00:06:26,200
When the males fight,
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00:06:26,200 --> 00:06:29,080
they take no notice of any pup
that gets in their way.
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00:06:31,920 --> 00:06:33,760
GRUNTS
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00:06:33,760 --> 00:06:35,760
The pup's mother intervenes...
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00:06:40,280 --> 00:06:43,000
...allowing her pup to wriggle away.
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00:06:49,680 --> 00:06:52,920
Finally, the battle turns.
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00:06:57,080 --> 00:07:00,680
The intruder starts to retreat
towards the sea.
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00:07:04,200 --> 00:07:07,280
Now, the smaller males
join the chase.
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00:07:20,360 --> 00:07:24,320
The big male has retained
his right to mate.
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00:07:29,360 --> 00:07:33,400
Despite these battles, Blakeney
Point still provides the pups
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00:07:33,400 --> 00:07:35,600
with an excellent start in life.
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00:07:37,240 --> 00:07:39,840
5,000 are born here each year.
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00:07:43,840 --> 00:07:47,880
A remarkable 40% of the world
population of grey seals
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00:07:47,880 --> 00:07:50,320
lives around the British Isles.
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00:07:52,040 --> 00:07:55,480
Impressive evidence of the richness
of our seas.
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00:08:00,680 --> 00:08:04,640
Beneath the surface,
that wealth is very evident.
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00:08:15,400 --> 00:08:18,800
Cold, nutrient-rich currents
from the north
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00:08:18,800 --> 00:08:22,280
mingle with the warm waters
of the gulf stream,
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00:08:22,280 --> 00:08:26,560
and support an astonishing variety
of plants and animals.
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00:08:31,360 --> 00:08:34,720
There are more than 10,000
different species here.
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00:09:09,520 --> 00:09:13,720
The effect of the gulf stream
is felt most keenly
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00:09:13,720 --> 00:09:17,920
at our southernmost point,
around the Isles of Scilly.
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00:09:21,240 --> 00:09:24,640
Here grows one of the biggest
stretches of seagrass
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to be found anywhere
in British and Irish waters.
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00:09:31,000 --> 00:09:35,400
Seagrass is important globally
because it collects carbon
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00:09:35,400 --> 00:09:39,560
up to 35 times faster
than a tropical rainforest.
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00:09:42,560 --> 00:09:46,240
But we have lost nearly 90%
of our seagrass,
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00:09:46,240 --> 00:09:50,400
mainly because of pollution
and disturbance of the seabed.
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00:09:53,800 --> 00:09:56,720
Nonetheless, these marine meadows
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00:09:56,720 --> 00:10:00,280
are home to a wide variety
of small animals.
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00:10:01,720 --> 00:10:06,240
Including this
perhaps somewhat surprising one.
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00:10:11,120 --> 00:10:13,760
A spiny seahorse.
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00:10:14,800 --> 00:10:18,320
One of just two species of seahorse
that live in our waters.
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00:10:24,120 --> 00:10:27,800
They thrive in the warmth
brought by the gulf stream.
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00:10:35,480 --> 00:10:37,520
The seagrass provides them
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00:10:37,520 --> 00:10:40,680
with the seclusion they prefer
for their courtship.
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00:10:53,920 --> 00:10:57,480
A crucial part of their
underwater dance
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00:10:57,480 --> 00:11:01,600
involves a gentle entwining
of their tails.
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00:11:05,320 --> 00:11:09,000
It's behaviour you might
think to be more typical
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00:11:09,000 --> 00:11:12,480
of the warm, balmy waters
of the Mediterranean.
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00:11:21,960 --> 00:11:24,200
And there is another creature
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00:11:24,200 --> 00:11:27,480
that is also more usually found
in warmer waters.
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00:11:32,200 --> 00:11:34,240
The common cuttlefish.
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00:11:37,640 --> 00:11:41,840
It's the most northerly
of all cuttlefish species.
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00:11:44,160 --> 00:11:48,080
This pregnant female,
about the size of a rugby football,
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00:11:48,080 --> 00:11:52,760
is being guarded by a male
as she prepares to lay her eggs.
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00:11:55,280 --> 00:11:58,240
First, she cleans her chosen site
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00:11:58,240 --> 00:12:01,880
by squirting jets of water
over the seaweed.
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00:12:05,200 --> 00:12:08,040
Several dozen black eggs
are already here,
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00:12:08,040 --> 00:12:10,520
having been laid the previous day.
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00:12:21,600 --> 00:12:23,680
And now she adds more...
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00:12:24,640 --> 00:12:29,440
...one by one, until there are
up to 3,000 or so.
106
00:12:38,920 --> 00:12:40,840
A month later...
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00:12:43,680 --> 00:12:48,120
...during the night,
the eggs start to hatch.
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00:12:54,440 --> 00:12:59,840
A perfectly formed baby cuttlefish,
no larger than a pea.
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00:13:06,680 --> 00:13:08,880
Within a few weeks,
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00:13:08,880 --> 00:13:12,400
a male has grown to a length
of around six centimetres
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00:13:12,400 --> 00:13:15,400
and is already a stealthy hunter.
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00:13:26,160 --> 00:13:31,000
His eyesight is so sensitive
that he's able to hunt by moonlight.
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00:13:53,720 --> 00:13:56,000
But when the moon disappears...
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00:13:58,120 --> 00:14:00,600
...even he cannot see
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00:14:00,600 --> 00:14:05,040
and the darkness usually
brings hunting to an end.
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00:14:09,800 --> 00:14:12,280
But on just a few nights
each year...
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00:14:13,240 --> 00:14:15,760
...something extraordinary happens.
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00:14:19,720 --> 00:14:26,160
Tiny light-producing algae create
vast clouds of bioluminescence.
119
00:14:30,800 --> 00:14:35,880
They're stimulated to switch on
by any sudden movement in the water.
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00:14:42,400 --> 00:14:46,200
Even the slight swirl produced
by a tiny crab as it breathes
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00:14:46,200 --> 00:14:48,120
has an effect.
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00:14:52,120 --> 00:14:54,840
The hunter must move very smoothly,
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00:14:54,840 --> 00:14:58,000
to avoid creating a light show
of his own.
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00:15:26,200 --> 00:15:30,240
The light of the algae
has enabled it to see its prey
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00:15:30,240 --> 00:15:32,760
and so hunt throughout the night.
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00:15:40,480 --> 00:15:44,360
A year later,
the cuttlefish are fully grown
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00:15:44,360 --> 00:15:47,880
and this male is now looking
for a female.
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00:15:51,280 --> 00:15:55,280
But the traditional
breeding site is empty.
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00:16:03,240 --> 00:16:05,840
The cuttlefish that
gathered here to mate...
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00:16:07,240 --> 00:16:09,920
...have been caught in a fishing pot.
131
00:16:14,440 --> 00:16:18,040
They may be among the most
intelligent animals in the sea...
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00:16:19,760 --> 00:16:23,160
...but they've been fooled
by a simple trap.
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00:16:26,560 --> 00:16:29,560
And once in it, there is no escape.
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00:16:46,800 --> 00:16:51,320
The male outside
spots a possible mate.
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00:16:59,760 --> 00:17:01,920
But he can't reach her.
136
00:17:15,280 --> 00:17:20,120
Our cuttlefish population can
tolerate some loss to fishing,
137
00:17:20,120 --> 00:17:25,280
but surely we shouldn't put pots
where they habitually breed,
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00:17:25,280 --> 00:17:28,960
and prevent them from
producing their next generation
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00:17:45,640 --> 00:17:51,760
Away from the coast, the seabed
may seem barren and lifeless.
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00:17:53,640 --> 00:17:56,440
But looks can be deceptive.
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00:17:59,000 --> 00:18:03,840
This muddy seafloor
is rich in bacteria and algae
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00:18:03,840 --> 00:18:08,440
and provides food
for one animal in particular.
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00:18:10,160 --> 00:18:14,880
A slow-moving creature that can grow
up to a length of six centimetres.
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00:18:17,760 --> 00:18:21,040
The royal flush sea slug.
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00:18:25,320 --> 00:18:28,520
Thousands graze the seafloor here.
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00:18:33,120 --> 00:18:36,280
But with so much competition
for the same food,
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00:18:36,280 --> 00:18:38,520
supplies eventually run out.
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00:18:40,280 --> 00:18:42,880
And the sea slugs have to move on...
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00:18:43,880 --> 00:18:46,200
...in their own strange way.
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00:18:50,120 --> 00:18:55,280
They flap their wing-like mantles
and rise up from the seabed.
151
00:19:01,640 --> 00:19:06,520
Drifting on the slow current,
they can travel for miles.
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00:19:26,400 --> 00:19:31,680
This extraordinary mass migration
has never been filmed before.
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00:19:47,160 --> 00:19:51,360
Eventually, they reach
new feeding grounds.
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00:20:04,480 --> 00:20:09,280
And now they can start
hoovering the seabed once more.
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00:20:19,120 --> 00:20:21,960
As spring turns to summer,
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00:20:21,960 --> 00:20:27,320
another very different migration
begins all along the south coast,
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00:20:27,320 --> 00:20:29,800
and for a very different reason.
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00:20:33,760 --> 00:20:36,440
A young female spider crab.
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00:20:39,480 --> 00:20:44,640
She is searching these sandy plains
for others of her own kind.
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00:20:54,680 --> 00:20:57,440
Spider crabs are normally solitary,
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00:20:57,440 --> 00:21:02,320
but now, in the summer,
they start to assemble into groups.
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00:21:05,800 --> 00:21:10,680
And then, when there are enough
of them, they start to travel.
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00:21:20,080 --> 00:21:23,720
Together, they journey for miles
across the seabed,
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00:21:23,720 --> 00:21:27,000
all heading in the same direction.
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00:21:40,040 --> 00:21:42,080
Groups join together
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00:21:42,080 --> 00:21:47,160
and the travellers become one great
horde, several-thousand strong.
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00:21:51,840 --> 00:21:55,880
They are about to face the most
dangerous time of their lives.
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00:22:01,200 --> 00:22:06,760
They have outgrown their hard shells
and must now escape from them.
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00:22:11,560 --> 00:22:13,880
A new shell is expandable,
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00:22:13,880 --> 00:22:17,320
but it remains soft
for several hours
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00:22:17,320 --> 00:22:21,160
and until it hardens,
its owner has no defence.
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00:22:27,280 --> 00:22:30,720
That is why they've made
this journey together.
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There is safety in numbers.
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00:22:46,600 --> 00:22:50,600
Ocean currents are one reason
why our waters are so rich.
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00:22:50,600 --> 00:22:54,840
Another is the exceptional size
of our tides.
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00:22:56,320 --> 00:22:58,400
Vast amounts of water
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00:22:58,400 --> 00:23:01,400
are continuously transported
around our islands
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00:23:01,400 --> 00:23:03,560
by these powerful currents.
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00:23:06,800 --> 00:23:10,320
The third biggest tidal rise
and fall on the planet
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00:23:10,320 --> 00:23:13,600
occurs in the estuary
of the River Severn.
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00:23:17,920 --> 00:23:19,800
From low tide,
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00:23:19,800 --> 00:23:23,920
the sea level rises by as much as
the height of a five-storey building
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00:23:23,920 --> 00:23:27,680
and then falls again,
twice every day.
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00:23:31,840 --> 00:23:36,000
These huge transformations
churn-up the nutrients
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00:23:36,000 --> 00:23:38,800
and replenish the mudflats.
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00:23:48,640 --> 00:23:51,840
Further north,
on the west coast of Scotland,
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00:23:51,840 --> 00:23:56,200
the power of our tides
creates another great spectacle.
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00:24:00,560 --> 00:24:03,000
The Corryvreckan whirlpool.
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00:24:03,000 --> 00:24:05,440
25 metres across.
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00:24:12,400 --> 00:24:15,480
It's the third largest whirlpool
in the world.
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00:24:21,920 --> 00:24:25,560
These powerful tidal currents
mix-up the water,
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00:24:25,560 --> 00:24:30,320
constantly bringing nutrients from
the depths up to the surface layers.
193
00:24:35,840 --> 00:24:40,840
And the influence of the tides can
extend right down to the seafloor.
194
00:24:45,240 --> 00:24:49,320
The animals down here thrive
in these ever-moving currents.
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00:24:49,320 --> 00:24:53,040
Every square inch
is bursting with life.
196
00:25:00,000 --> 00:25:04,120
The flowing water brings
a never-ending supply of food.
197
00:25:05,400 --> 00:25:10,040
Brittle stars and sea cucumbers
compete to collect all they can.
198
00:25:20,560 --> 00:25:24,240
So many creatures
inevitably attracts predators.
199
00:25:33,440 --> 00:25:37,360
{\an8}The seven-armed starfish -
half a metre across.
200
00:25:39,720 --> 00:25:43,120
{\an8}The brittle stars do their
best to get out of their way.
201
00:25:49,520 --> 00:25:52,840
The huge starfish
feel for their prey
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00:25:52,840 --> 00:25:55,800
using hundreds of sensitive
tubed feet
203
00:25:55,800 --> 00:25:58,720
that line the underside
of their arms.
204
00:26:01,200 --> 00:26:05,560
Yet, not every animal they encounter
tries to escape.
205
00:26:08,640 --> 00:26:11,600
This hermit crab,
with its powerful claws,
206
00:26:11,600 --> 00:26:14,160
is well able to defend itself.
207
00:26:24,480 --> 00:26:29,480
Finally, the persistent starfish
find what they're looking for.
208
00:26:35,400 --> 00:26:37,520
A queen scallop.
209
00:26:41,280 --> 00:26:46,520
Its lines of simple black eyes are
able to detect fast-moving threats.
210
00:26:49,040 --> 00:26:52,080
But the starfish moves
quite slowly...
211
00:26:54,600 --> 00:26:57,280
...and the scallop doesn't notice.
212
00:27:00,000 --> 00:27:03,320
Only when the scallop feels
the predator's probing feet,
213
00:27:03,320 --> 00:27:05,240
does it react.
214
00:27:11,120 --> 00:27:15,360
It swims away by clapping together
the two parts of its shell.
215
00:27:21,440 --> 00:27:24,480
It's a surprisingly
effective technique,
216
00:27:24,480 --> 00:27:27,840
and with luck will carry
the scallop to safety.
217
00:27:32,480 --> 00:27:36,160
But scallops don't have
a strong sense of direction...
218
00:27:39,400 --> 00:27:42,760
...and the starfish just keep coming.
219
00:27:46,360 --> 00:27:50,360
The starfish first pulls
the scallop shell apart
220
00:27:50,360 --> 00:27:53,600
and then inserts
its extendable stomach
221
00:27:53,600 --> 00:27:56,040
to digest the scallop's flesh.
222
00:27:58,720 --> 00:28:01,840
The smell of the feast
drifts through the water
223
00:28:01,840 --> 00:28:03,880
and attracts scavengers.
224
00:28:07,120 --> 00:28:08,640
Whelks.
225
00:28:10,560 --> 00:28:13,000
They are the clean-up crew.
226
00:28:18,360 --> 00:28:23,360
Tidal beds like these can easily
be destroyed by bottom-trawling.
227
00:28:25,240 --> 00:28:28,000
Protecting those that survive
is essential
228
00:28:28,000 --> 00:28:31,080
if we are to preserve
the richness of our seas.
229
00:28:37,880 --> 00:28:42,040
100 miles from mainland
Scotland lies Shetland,
230
00:28:42,040 --> 00:28:44,920
the most northerly part
of the British Isles.
231
00:28:47,240 --> 00:28:50,120
Because this archipelago
is in the open ocean,
232
00:28:50,120 --> 00:28:52,320
it has some of our cleanest waters.
233
00:29:04,320 --> 00:29:07,640
This is one of the reasons
why Shetland
234
00:29:07,640 --> 00:29:11,000
is our main stronghold for otters.
235
00:29:18,800 --> 00:29:24,160
More than 1,000 live along its 1,600
miles of undisturbed coastline.
236
00:29:34,200 --> 00:29:38,280
Shetland's isolation and its
relative lack of pollution
237
00:29:38,280 --> 00:29:40,520
suits these animals very well.
238
00:29:43,080 --> 00:29:46,640
Elsewhere, most live in
or beside rivers,
239
00:29:46,640 --> 00:29:50,640
but here they spend much
of their time in the sea.
240
00:29:59,520 --> 00:30:01,880
Each has its own territory
241
00:30:01,880 --> 00:30:05,560
and knows where its prey
is likely to be hiding.
242
00:30:08,480 --> 00:30:13,120
But the waters in which they spend
so much of their time are chilly,
243
00:30:13,120 --> 00:30:17,240
and otters need a lot of food
to keep themselves warm.
244
00:30:24,680 --> 00:30:27,840
They can hold their breath
for up to 90 seconds...
245
00:30:30,040 --> 00:30:33,920
...and reach hunting grounds
as deep as ten metres.
246
00:30:45,800 --> 00:30:51,240
In summer, the waters teem
with small fish, such as eelpout,
247
00:30:51,240 --> 00:30:55,880
which are easy to catch and are
excellent food for the cubs.
248
00:31:07,360 --> 00:31:11,200
Little wonder that Shetland
has the greatest density of otters
249
00:31:11,200 --> 00:31:13,240
anywhere in Europe.
250
00:31:21,320 --> 00:31:25,440
Otters are not the only stars
in Shetland's natural history.
251
00:31:28,160 --> 00:31:32,880
Around its coast
are habitats of global importance.
252
00:31:32,880 --> 00:31:35,400
Forests of kelp.
253
00:31:39,120 --> 00:31:42,360
They are among the thickest
and most vigorous of their kind
254
00:31:42,360 --> 00:31:44,440
in Britain and Ireland,
255
00:31:44,440 --> 00:31:48,080
with individuals growing
to over two metres tall.
256
00:31:52,200 --> 00:31:55,080
Like the seagrass,
this underwater forest
257
00:31:55,080 --> 00:31:57,600
captures great quantities
of carbon...
258
00:31:59,720 --> 00:32:03,200
...and provides a home
for a wide range of animals.
259
00:32:06,920 --> 00:32:10,000
One type of kelp here,
the furbellow,
260
00:32:10,000 --> 00:32:12,960
has an especially feisty resident.
261
00:32:15,040 --> 00:32:20,520
Its hollow base is the
favourite home of clingfish.
262
00:32:26,800 --> 00:32:29,760
This minute two-centimetre-long male
263
00:32:29,760 --> 00:32:33,800
has been left by his female
to look after the eggs.
264
00:32:35,480 --> 00:32:40,520
Hundreds of them are glued to the
interior of a furbellow's stem...
265
00:32:43,520 --> 00:32:45,880
...and they're almost ready to hatch.
266
00:32:49,640 --> 00:32:52,480
It's quite a responsibility for him.
267
00:32:54,360 --> 00:32:59,000
All day long, he fans fresh,
oxygen-rich sea water
268
00:32:59,000 --> 00:33:01,000
across the eggs.
269
00:33:04,720 --> 00:33:06,840
{\an8}He inspects them regularly
270
00:33:06,840 --> 00:33:10,600
{\an8}and quickly removes any
that are infertile or dead.
271
00:33:15,240 --> 00:33:18,560
But his nursery is under attack.
272
00:33:32,760 --> 00:33:36,200
Sea urchins are devouring
the furbellow.
273
00:33:41,480 --> 00:33:45,520
Their powerful jaws are destroying
the clingfish's home.
274
00:33:49,920 --> 00:33:55,040
His babies are under threat, still
stuck to the walls of their nursery.
275
00:33:58,880 --> 00:34:01,080
There is no escape.
276
00:34:04,560 --> 00:34:07,040
Their tiny father takes action.
277
00:34:11,160 --> 00:34:14,600
He tries to drive the urchins away
by beating his tail.
278
00:34:17,920 --> 00:34:19,960
But it makes little difference.
279
00:34:21,280 --> 00:34:23,720
Time for another strategy.
280
00:34:25,480 --> 00:34:28,360
The urchins are covered
in sharp spines...
281
00:34:29,720 --> 00:34:34,640
...so the brave little father nips
the urchins' sensitive tubed feet.
282
00:34:43,320 --> 00:34:49,280
Finally, the urchins give up
and go in search of easier meals.
283
00:34:52,440 --> 00:34:56,360
The little male clingfish has
saved his young.
284
00:35:04,880 --> 00:35:07,800
He is part of a crucial community
285
00:35:07,800 --> 00:35:12,360
that maintains the balance
in this marine rainforest.
286
00:35:24,200 --> 00:35:27,680
At the height of summer,
the power of the sun combines
287
00:35:27,680 --> 00:35:30,840
with the stirring action
of the tides and the waves...
288
00:35:32,400 --> 00:35:34,440
...and the ocean blooms.
289
00:35:37,000 --> 00:35:39,040
The creators of these blooms
290
00:35:39,040 --> 00:35:42,720
are myriads of floating,
microscopic algae.
291
00:35:44,400 --> 00:35:48,680
They are the basis of the entire
food chain in the open ocean.
292
00:35:50,120 --> 00:35:55,320
And when conditions are right, they
multiply at an astonishing rate.
293
00:35:57,880 --> 00:36:01,040
Their repeated blooms
are one of the main reasons
294
00:36:01,040 --> 00:36:04,840
why the seas around Britain
and Ireland are so productive.
295
00:36:08,400 --> 00:36:14,480
The floating plants support a great
community of tiny floating animals,
296
00:36:14,480 --> 00:36:16,600
the zooplankton.
297
00:36:18,320 --> 00:36:23,760
Tiny creatures that drift in great
clouds driven by the ocean currents.
298
00:36:25,360 --> 00:36:29,680
Among them are copepods,
tiny crustaceans
299
00:36:29,680 --> 00:36:33,880
that feed on the microscopic algae
floating alongside them.
300
00:36:35,800 --> 00:36:38,080
The rest are mainly predators.
301
00:36:42,480 --> 00:36:44,800
Many of these are also tiny.
302
00:36:46,040 --> 00:36:49,960
The larvae of bottom-living animals
like lobsters and crabs,
303
00:36:49,960 --> 00:36:53,000
some only 5mm long.
304
00:36:57,200 --> 00:36:59,240
There are also sea gooseberries,
305
00:36:59,240 --> 00:37:02,160
which propel themselves
through the water
306
00:37:02,160 --> 00:37:04,920
with rows of pulsating bristles.
307
00:37:09,000 --> 00:37:13,160
They may look fragile, but they
are surprisingly effective hunters.
308
00:37:18,760 --> 00:37:21,960
They extend long,
thread-like tentacles.
309
00:37:26,000 --> 00:37:31,480
Other drifters that get entangled
are reeled-in and eaten.
310
00:37:36,760 --> 00:37:39,440
The sea gooseberries themselves,
of course,
311
00:37:39,440 --> 00:37:42,880
are also prey for
larger predators...
312
00:37:44,400 --> 00:37:46,960
...such as the melon comb jelly.
313
00:38:13,520 --> 00:38:16,840
It has a particularly large mouth.
314
00:38:24,160 --> 00:38:27,280
When it opens it,
the suction it creates
315
00:38:27,280 --> 00:38:30,160
pulls its prey straight
into its stomach.
316
00:38:37,840 --> 00:38:40,280
Despite the richness of our seas,
317
00:38:40,280 --> 00:38:45,080
climate change is seriously reducing
the amount of zooplankton.
318
00:38:47,680 --> 00:38:51,960
And this has an effect on
the entire marine food chain,
319
00:38:51,960 --> 00:38:55,160
right up to real giants.
320
00:39:00,280 --> 00:39:05,800
The largest fish in our waters
is as long as a double-decker bus.
321
00:39:09,400 --> 00:39:11,320
The basking shark.
322
00:39:15,040 --> 00:39:18,480
It uses special sieve-like
structures on its gills
323
00:39:18,480 --> 00:39:21,200
to filter out the zooplankton.
324
00:39:23,720 --> 00:39:26,680
And they feed on nothing else.
325
00:39:29,240 --> 00:39:35,560
In summer, these giants come close
to the coast all around our isles.
326
00:39:47,640 --> 00:39:49,800
They're normally solitary,
327
00:39:49,800 --> 00:39:53,480
but when the plankton reaches
the peak of its abundance,
328
00:39:53,480 --> 00:39:56,360
the sharks come together.
329
00:40:03,240 --> 00:40:05,360
They swim in formation.
330
00:40:05,360 --> 00:40:10,400
Plankton that escapes one mouth
will be scooped-up by the next.
331
00:40:17,520 --> 00:40:19,960
In just a few special places
332
00:40:19,960 --> 00:40:23,440
along the western coasts
of Britain and Ireland,
333
00:40:23,440 --> 00:40:28,800
basking sharks gather in large
numbers to feed and breed.
334
00:40:35,200 --> 00:40:37,920
Thousands find their way here
each year...
335
00:40:39,400 --> 00:40:41,960
...a major part of the
global population.
336
00:40:53,760 --> 00:40:57,360
Plankton feeders come in all sizes.
337
00:41:01,320 --> 00:41:04,880
Sand eels are only
30 centimetres long,
338
00:41:04,880 --> 00:41:08,000
but they occur in vast shoals.
339
00:41:12,960 --> 00:41:16,880
Like so many species,
overfishing and warming seas
340
00:41:16,880 --> 00:41:19,480
have drastically reduced
their numbers.
341
00:41:21,680 --> 00:41:26,600
They are essential prey
for a wide range of top predators.
342
00:41:32,360 --> 00:41:37,360
Dolphins scour vast areas of the
open ocean to track down the shoals.
343
00:41:41,480 --> 00:41:45,560
And following the dolphins
comes an ocean legend...
344
00:41:47,400 --> 00:41:49,160
...bluefin tuna.
345
00:41:52,080 --> 00:41:54,200
Weighing up to 700 kilos
346
00:41:54,200 --> 00:41:57,240
and with a top speed of more
than 40mph,
347
00:41:57,240 --> 00:42:02,640
these powerful predators
can make quick work of the shoal.
348
00:42:05,040 --> 00:42:09,560
Bluefins have been absent from
our waters for more than 50 years.
349
00:42:13,000 --> 00:42:15,800
And they have only
recently returned.
350
00:42:18,360 --> 00:42:20,280
If they are to stay,
351
00:42:20,280 --> 00:42:23,800
the overfishing of our seas
will have to be stopped.
352
00:42:26,120 --> 00:42:28,040
In the sky above...
353
00:42:29,000 --> 00:42:33,360
...gannets, looking for fish
such as mackerel and herring.
354
00:42:43,080 --> 00:42:45,920
They hit the water at over 60mph.
355
00:42:51,880 --> 00:42:54,000
The impact is enormous.
356
00:42:56,520 --> 00:42:59,720
To avoid breaking their wings,
they fold them back
357
00:42:59,720 --> 00:43:02,800
and turn themselves
into streamlined arrows.
358
00:43:23,120 --> 00:43:27,160
65% of the world's population
of northern gannets
359
00:43:27,160 --> 00:43:30,240
find their food in our seas.
360
00:43:49,080 --> 00:43:52,760
But perhaps the bird that depends
most on the still-rich waters
361
00:43:52,760 --> 00:43:57,600
around Britain and Ireland
is the Manx shearwater.
362
00:44:04,760 --> 00:44:07,160
Every year, our coasts are visited
363
00:44:07,160 --> 00:44:11,440
by almost the entire global
population of this sea bird.
364
00:44:15,920 --> 00:44:19,480
Here in Cardigan Bay
off central Wales,
365
00:44:19,480 --> 00:44:22,520
they gather in their thousands,
366
00:44:22,520 --> 00:44:26,120
attracted by the richness
of our seas.
367
00:44:36,000 --> 00:44:40,720
Each summer, 350,000 pairs
all return
368
00:44:40,720 --> 00:44:44,400
to this tiny island of Skomer
off the Pembrokeshire coast.
369
00:44:44,400 --> 00:44:48,040
This is the largest
breeding colony in the world
370
00:44:48,040 --> 00:44:51,600
and most of the island is
honeycombed with their burrows.
371
00:44:51,600 --> 00:44:54,600
Tonight, under the cover
of darkness,
372
00:44:54,600 --> 00:44:57,680
their chicks are starting
to leave these burrows
373
00:44:57,680 --> 00:44:59,800
for the very first time.
374
00:45:02,720 --> 00:45:07,160
Watching them do so
is an unforgettable privilege.
375
00:45:11,880 --> 00:45:16,080
This young bird has just
emerged from its nest hole,
376
00:45:16,080 --> 00:45:18,360
maybe for the first time.
377
00:45:19,960 --> 00:45:24,080
It's about to make the most
important journey of its life.
378
00:45:25,600 --> 00:45:30,080
And it needs to get every inch
of altitude before it takes off.
379
00:45:31,680 --> 00:45:33,680
I can just see beyond me...
380
00:45:34,840 --> 00:45:36,800
...there are more of them.
381
00:45:38,200 --> 00:45:40,960
One, two, three, four.
382
00:45:44,520 --> 00:45:46,880
It's just exercising its wings...
383
00:45:48,680 --> 00:45:51,720
...in preparation for this
extraordinary flight...
384
00:45:52,920 --> 00:45:57,640
...which will take it 6,000 miles
across the oceans
385
00:45:57,640 --> 00:46:01,760
to South America,
to Brazil and Argentina.
386
00:46:02,880 --> 00:46:05,720
And then, after some four years,
387
00:46:05,720 --> 00:46:10,560
once again it will set out
on a long oceanic journey,
388
00:46:10,560 --> 00:46:16,520
a further 6,000 miles back to
this one small island of Skomer.
389
00:46:18,120 --> 00:46:20,000
Are you going to go?
390
00:46:20,000 --> 00:46:23,480
It's hesitating
and who can blame it?
391
00:46:24,680 --> 00:46:29,240
An enormous journey awaits it
once it takes off from here.
392
00:46:31,200 --> 00:46:35,480
This is the headquarters
of this astonishing species
393
00:46:36,600 --> 00:46:39,080
...and we are its custodians.
394
00:46:40,400 --> 00:46:44,240
Come along. Come along.
395
00:46:45,400 --> 00:46:47,240
Are you about to take off?
396
00:46:50,560 --> 00:46:52,200
Good luck!
397
00:46:53,640 --> 00:46:55,080
HE CHUCKLES
398
00:46:56,080 --> 00:46:58,480
What an astonishment.
399
00:47:11,360 --> 00:47:14,320
A lot has changed in my lifetime
400
00:47:14,320 --> 00:47:17,200
and today the wildlife
we still have
401
00:47:17,200 --> 00:47:20,120
faces greater threats
than ever before.
402
00:47:20,120 --> 00:47:23,920
Our sea birds remind us
that here in Britain and Ireland
403
00:47:23,920 --> 00:47:28,280
we are very fortunate to have some
of nature's greatest spectacles
404
00:47:28,280 --> 00:47:30,360
right on our doorstep.
405
00:47:31,400 --> 00:47:33,440
Because this is our home,
406
00:47:33,440 --> 00:47:37,960
it can only be our responsibility
to restore and protect our wildlife.
407
00:47:37,960 --> 00:47:42,960
Perhaps you can be the first
to pass these wild isles
408
00:47:42,960 --> 00:47:48,200
on to the next generation in better
shape than you inherited them.
409
00:48:19,720 --> 00:48:24,680
From the Isles of Scilly in the
south, to Shetland in the north,
410
00:48:24,680 --> 00:48:29,120
the ocean team spent 300 days
filming the marine wildlife
411
00:48:29,120 --> 00:48:31,840
of the British Isles
as never before.
412
00:48:33,240 --> 00:48:35,280
They captured new behaviours,
413
00:48:35,280 --> 00:48:38,880
experienced the worst
of the Atlantic weather,
414
00:48:38,880 --> 00:48:43,360
and witnessed intimate moments
in the lives of our ocean wildlife.
415
00:48:44,600 --> 00:48:49,280
Doug Anderson, is one of the world's
leading underwater camera operators.
416
00:48:49,280 --> 00:48:51,600
He's worked all over the planet,
417
00:48:51,600 --> 00:48:56,520
filming some of the ocean's greatest
spectacles and largest inhabitants.
418
00:48:57,840 --> 00:49:01,640
And for this series, he filmed
the majority of the ocean episode.
419
00:49:03,280 --> 00:49:07,280
His passion for the underwater
world began on the Isle of Arran,
420
00:49:07,280 --> 00:49:09,680
off the west coast of Scotland.
421
00:49:09,680 --> 00:49:12,760
{\an8}My first underwater experience
was in Lamlash Bay
422
00:49:12,760 --> 00:49:15,000
{\an8}in front of my grandparents' house
423
00:49:15,000 --> 00:49:18,040
and it is burnt into my memory.
424
00:49:18,040 --> 00:49:23,040
My dad had made me a wet suit and I
remember putting my face underwater
425
00:49:23,040 --> 00:49:28,880
and just being blown away
but the wildness of it.
426
00:49:28,880 --> 00:49:31,840
You know, there were crabs
and little fish
427
00:49:31,840 --> 00:49:33,880
and it felt like a wild place.
428
00:49:33,880 --> 00:49:35,760
I remember lifting my head up
429
00:49:35,760 --> 00:49:38,400
and looking over my shoulder
back at the village -
430
00:49:38,400 --> 00:49:40,680
there was, like, the policeman
doing his round,
431
00:49:40,680 --> 00:49:43,240
and people going to the shop
and I was like,
432
00:49:43,240 --> 00:49:47,680
"Oh, the ocean is a wild place
and behind me is what people do."
433
00:49:47,680 --> 00:49:50,000
And I never recovered.
434
00:49:53,800 --> 00:49:56,000
After learning to dive,
435
00:49:56,000 --> 00:49:58,960
Doug's passion for
the underwater world
436
00:49:58,960 --> 00:50:01,800
took him on a journey
far from home.
437
00:50:01,800 --> 00:50:04,880
I eventually got a job on a series
called The Blue Planet,
438
00:50:04,880 --> 00:50:06,840
back in the mid-'90s.
439
00:50:06,840 --> 00:50:09,560
And then just found myself
on plane out to the Azores.
440
00:50:09,560 --> 00:50:12,880
Yeah, I was, like, 27 years old,
and that was the start.
441
00:50:14,160 --> 00:50:16,880
Until now, he's never
had the chance to show
442
00:50:16,880 --> 00:50:19,600
what the British Isles
has to offer.
443
00:50:19,600 --> 00:50:23,360
On the Wild Isles project, it just
felt like an amazing opportunity
444
00:50:23,360 --> 00:50:26,640
and responsibility to take
everything I've learned
445
00:50:26,640 --> 00:50:29,800
in 25 years of working
all over the planet,
446
00:50:29,800 --> 00:50:33,320
and just applying
all of that to here.
447
00:50:33,320 --> 00:50:36,200
Although they might be
easier to reach,
448
00:50:36,200 --> 00:50:38,520
our waters have
their own challenges.
449
00:50:40,440 --> 00:50:42,400
This project, in many ways,
450
00:50:42,400 --> 00:50:45,320
has been the hardest
professional experience of my life.
451
00:50:45,320 --> 00:50:48,640
Everything that you do on the ocean
in the North Atlantic is tough.
452
00:50:48,640 --> 00:50:51,040
We can have four seasons in a day.
453
00:50:52,160 --> 00:50:54,920
This unpredictability
makes filming in our seas
454
00:50:54,920 --> 00:50:56,960
a matter of boom or bust.
455
00:50:58,560 --> 00:51:00,760
The team must be on constant standby
456
00:51:00,760 --> 00:51:03,840
to mobilise quickly
when conditions are right.
457
00:51:05,720 --> 00:51:08,800
In Shetland,
they're heading for the seabed.
458
00:51:11,440 --> 00:51:13,480
To record life down here,
459
00:51:13,480 --> 00:51:17,280
Doug has designed and built
his own bespoke underwater tripod.
460
00:51:19,000 --> 00:51:21,840
High-powered lights
illuminate the seafloor...
461
00:51:22,800 --> 00:51:25,640
...and weights stabilise the rig,
462
00:51:25,640 --> 00:51:29,920
{\an8}allowing Doug to film a time-lapse
of these slow-moving creatures,
463
00:51:29,920 --> 00:51:35,160
{\an8}revealing a world that few people
will ever see in actuality.
464
00:51:36,600 --> 00:51:40,360
Below the kelp, Doug takes
his design a step further -
465
00:51:40,360 --> 00:51:44,880
a motion-controlled slider
for tracking timelapses.
466
00:51:44,880 --> 00:51:48,920
Now, he can move the camera
with pinpoint accuracy,
467
00:51:48,920 --> 00:51:52,360
revealing how urchins travel
through this marine forest.
468
00:51:53,720 --> 00:51:56,480
A shot that's taken
months of preparation.
469
00:51:59,600 --> 00:52:02,840
But not everything in our oceans
is as slow-moving.
470
00:52:03,800 --> 00:52:05,800
Off the coast of Cornwall,
471
00:52:05,800 --> 00:52:09,360
the team are chasing one
of the ocean's fastest inhabitants,
472
00:52:09,360 --> 00:52:11,240
bluefin tuna.
473
00:52:12,200 --> 00:52:15,440
They have only retuned to our waters
in the last few years.
474
00:52:16,680 --> 00:52:19,120
We've got all the ingredients
that we need here.
475
00:52:19,120 --> 00:52:21,080
We've got dolphins, we've got tuna,
476
00:52:21,080 --> 00:52:23,440
there's gannets here,
and shearwaters.
477
00:52:23,440 --> 00:52:26,520
But we need it to come together
into something that we can film,
478
00:52:26,520 --> 00:52:28,240
and that's a bait ball.
479
00:52:28,240 --> 00:52:31,120
So it has to be a patch of fish
jammed up against the surface
480
00:52:31,120 --> 00:52:34,000
in reasonable visibility
to make it work, so...
481
00:52:35,440 --> 00:52:37,080
...fingers crossed.
482
00:52:38,400 --> 00:52:40,400
Bait balls don't last long.
483
00:52:40,400 --> 00:52:43,720
They can be over
in a matter of minutes.
484
00:52:43,720 --> 00:52:46,920
So to film tuna hunting,
speed is everything.
485
00:52:48,640 --> 00:52:52,720
Radio call from one of our contacts,
so we screamed down there,
486
00:52:52,720 --> 00:52:57,160
only to discover we were
just a few moments too late.
487
00:52:57,160 --> 00:53:01,520
Which is really frustrating.
We've got a really fast boat.
488
00:53:06,480 --> 00:53:10,880
This is so new, this set-up here,
these bait fish coming here.
489
00:53:10,880 --> 00:53:13,080
It's five years, so we're just...
490
00:53:13,080 --> 00:53:16,360
Everyone's just working it out
and it seems like we're not alone
491
00:53:16,360 --> 00:53:19,720
cos it's like the dolphin and the
tuna are just beginning to find it
492
00:53:19,720 --> 00:53:21,760
and exploit the resource as well.
493
00:53:22,880 --> 00:53:26,000
The team use a drone
to help locate the tuna
494
00:53:26,000 --> 00:53:28,680
before the bait balls disappear.
495
00:53:30,680 --> 00:53:32,960
The exciting thing is,
this is England.
496
00:53:32,960 --> 00:53:35,560
We've got literally Falmouth
right there
497
00:53:35,560 --> 00:53:39,360
and we've got these crazy pods
of common dolphins rolling through
498
00:53:39,360 --> 00:53:42,200
and there's bluefin
showing every now and then.
499
00:53:42,200 --> 00:53:44,320
It's an amazing kind of ocean scene.
500
00:53:44,320 --> 00:53:46,920
Although it looks good from the air,
501
00:53:46,920 --> 00:53:51,440
poor visibility underwater prevents
Doug from getting a clear shot.
502
00:53:51,440 --> 00:53:56,120
Yeah, a total glimpse,
just like the briefest of moment.
503
00:53:56,120 --> 00:53:58,200
Pretty green water, I just get in,
504
00:53:58,200 --> 00:54:01,120
and they just come through
and just roll through.
505
00:54:02,720 --> 00:54:06,440
In the hope of finding clearer
water, the team change location.
506
00:54:07,680 --> 00:54:09,520
We're further down the coast.
507
00:54:09,520 --> 00:54:12,080
We're going to be working
further offshore,
508
00:54:12,080 --> 00:54:15,600
and we're going to be trying to join
the blue water with the bluefin.
509
00:54:15,600 --> 00:54:19,240
If a big patch of pilchards on the
surface or mackerel comes together,
510
00:54:19,240 --> 00:54:21,760
then come away with
what we want from this.
511
00:54:23,000 --> 00:54:25,520
We have tuna,
they're all over the place just now.
512
00:54:25,520 --> 00:54:28,640
We just need to wait for this
sort of pot to boil, you know.
513
00:54:28,640 --> 00:54:31,040
For the bait to come together
into a lump
514
00:54:31,040 --> 00:54:34,640
for long enough, for it to go static
so that we can get in and film it.
515
00:54:36,360 --> 00:54:38,040
The plan works!
516
00:54:38,040 --> 00:54:41,680
The team finally get the conditions
they have been seeking for so long.
517
00:54:41,680 --> 00:54:45,440
To actually see a bluefin tuna
underwater in England
518
00:54:45,440 --> 00:54:48,520
is just unbelievable.
519
00:54:50,240 --> 00:54:52,720
The return of bluefin tuna
to our waters
520
00:54:52,720 --> 00:54:55,680
is a sign that their population
is recovering.
521
00:54:55,680 --> 00:54:59,560
But it's still a fraction
of what their numbers could be.
522
00:55:02,960 --> 00:55:06,400
Since Doug left Arran
over two decades ago,
523
00:55:06,400 --> 00:55:10,120
the coastal community,
including his family,
524
00:55:10,120 --> 00:55:13,960
created Scotland's first
marine No Take Zone.
525
00:55:16,520 --> 00:55:22,600
Since its creation in Lamlash Bay,
biodiversity has increased fourfold.
526
00:55:24,240 --> 00:55:28,720
But it's one of just a handful of No
Take Zones around our wild isles,
527
00:55:28,720 --> 00:55:33,040
that combined, cover less
than 1% of our sea.
528
00:55:33,040 --> 00:55:35,440
The abundance of life within them
529
00:55:35,440 --> 00:55:38,560
spills out into the
surrounding waters,
530
00:55:38,560 --> 00:55:42,120
enriching and strengthening
the wider marine environment
531
00:55:42,120 --> 00:55:46,040
The way to get British seas back
is to allow large areas
532
00:55:46,040 --> 00:55:48,640
to return to a natural state,
533
00:55:48,640 --> 00:55:53,960
and maintain those very highly
protected areas for a long time.
534
00:55:54,960 --> 00:55:58,160
For Doug, celebrating
the beauty of British waters
535
00:55:58,160 --> 00:56:01,400
has been a chance for him
to give something back.
536
00:56:03,320 --> 00:56:06,600
If I can play a tiny part
about providing the visuals
537
00:56:06,600 --> 00:56:10,080
to allow that conversation to happen
in a meaningful way,
538
00:56:10,080 --> 00:56:13,120
for people on all sides
of the argument
539
00:56:13,120 --> 00:56:17,360
to imagine what lies
beneath those grey waves,
540
00:56:17,360 --> 00:56:20,960
then I think it would be
an extraordinary thing.
541
00:56:29,920 --> 00:56:33,000
The Open University has
produced a free poster
542
00:56:33,000 --> 00:56:37,960
exploring our Wild Isles and
their diverse habitat and species.
543
00:56:37,960 --> 00:56:41,000
Order your copy by calling...
544
00:56:43,760 --> 00:56:45,840
...or go to...
545
00:56:49,080 --> 00:56:50,760
...and follow the links
546
00:56:50,760 --> 00:56:52,600
to the Open University.
547
00:56:52,600 --> 00:56:56,440
If you'd like to play your part
in restoring our Wild Isles
548
00:56:56,440 --> 00:56:59,280
and learn more about
what you can do to help,
549
00:56:59,280 --> 00:57:02,840
just search Wild Isles
on the BBC website.
44084
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