- 1. The oceans, seemingly limitless,
- 2. invoke in us a sense of awe and wonder
and also sometimes fear.
- 3. They cover 70% of the surface
of our planet,
- 4. and yet they are still
the least explored.
- 5. Hidden beneath the waves
right beneath my feet,
- 6. there are creatures
beyond our imagination.
- 7. With revolutionary technology,
we can enter new worlds...
- 8. and shine a light on behaviours
- 9. in ways that were impossible
just a generation ago.
- 10. We've also recognised
an uncomfortable fact.
- 11. The health of our oceans
is under threat.
- 12. They're changing at a faster rate
than ever before in human history.
- 13. Never has there been a more crucial time
- 14. to reveal what is going on
beneath the surface of the seas.
- 15. In this first episode,
- 16. we will journey across the globe
from the warm waters of the tropics
- 17. to the coldest around the poles.
- 18. To bring us a new understanding
of live beneath the waves.
- 19. This is Blue Planet H.
- 20. The surface of the ocean conceals
the many creatures that live beneath
- 21. but not all.
- 22. Bottlenose dolphins.
- 23. They're extremely intelligent.
- 24. And with this intelligence
- 25. They surf.
- 26. And as far as we can tell,
they do so for the sheer joy of it.
- 27. But to properly appreciate
their true character,
- 28. you have to travel with them
into their world.
- 29. A pod of bottlenose dolphins is visiting
a coral reef in the Red Sea.
- 30. For the youngsters,
there are things to be learned here.
- 31. The adults lead a calf
to a particular bush-like coral
- 32. called a Gorgonian.
- 33. And here, the adults behave
- 34. They deliberately rub themselves
through the fronds.
- 35. Their calf seems reluctant to do so.
- 36. By watching his elders,
- 37. he may be realising
that this is something he ought to do.
- 38. Gorgonia fronds, in fact,
are covered with a mucous
- 39. that can have anti-inflammatory
and antimicrobial properties.
- 40. So maybe the adult dolphins
are doing this
- 41. to protect themselves from infection.
- 42. The dolphins' intimate knowledge
of the reef
- 43. is spurring us to search
for new medicines here, too.
- 44. Tropical coral reefs
- 45. occupy only a tenth of one percent
of the ocean floor.
- 46. But their shallow warm waters
and stable year round conditions,
- 47. support some of the most crowded
and varied communities
- 48. to be found anywhere in the oceans.
- 49. And there are new discoveries to be made
on every one of them.
- 50. One creature
on Australia's Great Barrier Reef
- 51. is challenging our understanding
of fish intelligence.
- 52. A tusk fish.
- 53. And you can see why it gets its name.
- 54. He does something
few would have believed a fish could do.
- 55. Every morning,
he travels to the edge of the reef.
- 56. He's searching
for something special to eat
- 57. amongst the coral and sand.
- 58. Here's one.
- 59. A small clam.
- 60. But how to crack it open
and get to the meat?
- 61. He takes it all the way back
- 62. to his special kitchen.
- 63. A bowl-shaped coral
- 64. that has a particular bump on the inside
that he always uses.
- 65. It's not easy if you have no hands.
- 66. Whoops.
- 67. There he goes again.
- 68. But he's got great determination
- 69. and surprising accuracy.
- 70. At last.
- 71. So here is a fish that uses tools.
- 72. Some fish are much cleverer
than you might suppose.
- 73. The density of the animals
on tropical reefs
- 74. makes competition
inevitable and extreme.
- 75. Not only for those that lived
within the reef,
- 76. but for the birds that fly above them.
- 77. During the dry season,
- 78. over half a million terns
- 79. crowd onto this remote atoll
in the Indian Ocean.
- 80. Their chicks are still
in their dark, juvenile plumage.
- 81. They vary in age.
- 82. Whilst the more advanced chicks
take to the air,
- 83. others aren't quite ready yet.
- 84. Those just starting to learn to fly
- 85. use the shallow lagoon
that occupies the centre of the atoll
- 86. as their training ground.
- 87. It's difficult for some of them
to stay aloft for long.
- 88. Giant trevallies.
- 89. Usually, they're solitary hunters,
- 90. but about 50 of them have come here
from neighbouring reefs
- 91. attracted by this abundance
of potential prey.
- 92. The fledglings stay out of the water
if they can,
- 93. they even drink on the wing.
- 94. If the trevally are to catch one now,
- 95. they have to up their game.
- 96. So there is a fish here that amazingly
- 97. has a brain capable of calculating
- 98. altitude and trajectory of a bird.
- 99. The time comes when every fledgling
has to take to the air
- 100. and collect food for itself.
- 101. Their parents lead them
to the training grounds.
- 102. If they're to survive,
- 103. they must learn quickly.
- 104. After a month of practising
over the lagoon,
- 105. the youngsters start to leave
- 106. and take their chances
out over the open sea.
- 107. The oceans hold 97% of all the water
in the world.
- 108. As the sun warms their surface,
- 109. The vapour rises into the sky
- 110. until it cools and condenses
into towering clouds.
- 111. And they generate huge storms.
- 112. The spin of the earth
deflects these storms
- 113. north and south into cooler latitudes.
- 114. As they travel across the sea,
- 115. storm-driven winds create huge swells.
- 116. When the swells reach shallower waters,
- 117. they rise into gigantic waves.
- 118. In its lifetime,
a large storm can release energy
- 119. that is the equivalent
of 70, 000 nuclear bombs.
- 120. These are the seasonal seas.
- 121. And when they warm in spring,
- 122. they can suddenly explode with life.
- 123. Mobula rays have gathered
in Mexico's Sea of Cortez
- 124. in vast numbers.
- 125. Why do they leap?
- 126. Is it to tell others that they're here?
- 127. No one knows.
- 128. They feed mostly at night
- 129. for that is when vast swarms
of plankton rise from the depths.
- 130. The disturbance in the water stimulates
many of the planktonic creatures
- 131. to luminesce.
- 132. Only now do we have the technology
to record their faint glow.
- 133. The feasting rays swim through them
- 134. creating an extraordinary ballet
of life and death.
- 135. The richness of these waters
is based on microscopic plants,
- 136. Phytoplankton,
- 137. which bloom on such a massive scale
they benefit us all.
- 138. They, together with seaweeds
and sea grasses,
- 139. produce as much oxygen
- 140. as all the forests
and grassy plains on land.
- 141. Every spring off New Zealand,
- 142. the seasonal bounty
draws in rare visitors.
- 143. False killer whales.
- 144. They're relatives of the orca,
- 145. six metres long
and weighing over a tonne.
- 146. They appear to be searching
- 147. And there are many
in these coastal waters.
- 148. Here, bottlenose dolphins stick together
- 149. constantly chattering
with whistles and clicks.
- 150. Such a din carries for miles underwater.
- 151. The false killers have detected them.
- 152. Travelling at ten knots,
the killers quickly close in on them.
- 153. But then,
something truly extraordinary happens.
- 154. The dolphins turn
- 155. as if to greet their pursuers.
- 156. They seem to change their course.
- 157. Could it be that they're attempting
- 158. Scientists studying
this annual encounter,
- 159. now think that individuals
may recognise one another.
- 160. Almost unbelievably,
it seems that these different species
- 161. appear to be old friends.
- 162. Together they're gathering
as one unified army
- 163. up to a thousand strong.
- 164. This formidable hunting party
now harvests the riches
- 165. that come with New Zealand's summer.
- 166. All across the higher latitudes,
- 167. seasonal seas flourish
under the summer sun.
- 168. Here in Alaska,
sea otters lounge in the canopy
- 169. of great submarine forests.
- 170. Giant kelp, the biggest seaweed of all
is home to all kinds of life.
- 171. On the forest floor, spiny
sea urchins munch through the kelp.
- 172. Elsewhere there are continuously hungry
- 173. And in the tangled undergrowth,
- 174. wonderfully camouflaged sea dragons.
- 175. In the underwater forests
of northern Japan,
- 176. the residents of this sunken wreck
- 177. are waiting for the summer temperatures
to reach 16 degrees Celsius.
- 178. That for some is the time for mating.
- 179. A kind of giant wrasse called a Kobudai.
- 180. This is a male.
- 181. And in female terms,
he's particularly handsome.
- 182. He's a metre long and weighs 15 kilos.
- 183. Much larger than the diminutive female,
- 184. and he is ready to breed.
- 185. He attempts to mate with her
- 186. and with any of the dozen or so females
that live in his territory,
- 187. whenever he gets the chance.
- 188. But females from around ten years old
- 189. take little notice of his advances.
- 190. This is because when any large female
reaches a critical body size,
- 191. she can begin a dramatic transformation.
- 192. Over just a few months,
- 193. particular enzymes inside her body
cease to work,
- 194. and male hormones start to circulate.
- 195. As time passes,
- 196. her head expands
- 197. and her chin gets longer.
- 198. A she has changed into a he.
- 199. And with this comes a change
- 200. The old male who rules
all the females here
- 201. is challenged to a face off.
- 202. The more bulbous the head,
- 203. the more it intimidates an opponent.
- 204. The territory has a new ruler.
- 205. Only the largest females transform
themselves in this way.
- 206. But the change enables them
to have more mates,
- 207. so they will have many more offspring
carrying their genes.
- 208. But a new male can't afford
to be complacent.
- 209. Inside the body of every Kobudai female,
- 210. there is a new male in waiting.
- 211. The closer we travel towards the poles,
the colder the seas become.
- 212. Icebergs appear.
- 213. Huge slabs that have broken away
- 214. from glaciers that are sliding
into the sea.
- 215. And then the surface starts to freeze.
- 216. While the lights of the aurora
- 217. even in the depths of midwinter,
- 218. there are a few places
well north of the Arctic circle
- 219. that are still open.
- 220. The fjords of northern Norway
remain ice free
- 221. because a giant current,
the Gulf Stream,
- 222. flows up here from the south
- 223. bringing warmth all the way
from the Caribbean.
- 224. And every winter,
- 225. billions of herring
come here for shelter.
- 226. And following them...
- 227. Orca.
- 228. There are up to a thousand of them.
- 229. It's possibly the greatest gathering
of orca on the planet.
- 230. The herring maybe plentiful
but in these winding fjords
- 231. they're not always easy to track down.
- 232. These particular orca, however,
- 233. are fish hunting specialists.
- 234. They work as a team,
- 235. coordinating their approach
by calling loudly to one another.
- 236. They herd the herring
into tighter and tighter shoals.
- 237. They swim below them,
- 238. trapping them against
the surface of the sea.
- 239. And now the orca deploy
their special weapon.
- 240. They beat their tails with such force,
- 241. that the shock waves stun the herring.
- 242. And then the senseless victims
are easily collected.
- 243. But all this underwater noise
- 244. Humpback whales.
- 245. They move in on the action.
- 246. They approach the shoal from beneath
and then lunge upwards,
- 247. gathering up to a hundred kilos
of herring in a single mouthful.
- 248. The humpbacks are comparative newcomers.
- 249. They only started coming here
within the last decade.
- 250. But these polars seas are so rich
- 251. that there appears to be enough food
- 252. Nonetheless, few if any of these riches
- 253. would be here were it not
for the Gulf Stream.
- 254. Ocean currents, in fact, are crucial
to the well being of our planet.
- 255. They distribute the sun's heat
towards the poles
- 256. all the way from the equator,
- 257. maintaining a climate favourable
for life almost everywhere.
- 258. From creating the weather
to producing oxygen,
- 259. the seas keep our world healthy.
- 260. But there are now worrying signs
- 261. that conditions in the oceans
- 262. that have remained relatively stable
- 263. are changing radically.
- 264. Nowhere is this more evident
than in the Arctic.
- 265. Here in the past 30 years,
- 266. the extent of the ice in summer
has been reduced by 40%.
- 267. This sudden warming,
- 268. most likely a consequence
of human activity,
- 269. is having a profound impact
on its wildlife.
- 270. Walruses are among those
that are seriously affected.
- 271. Every adult female
needs to find a safe place
- 272. where her 80-kilo pup can rest.
- 273. The sea ice is retreating
- 274. from much
of the walrus' traditional range,
- 275. so they now have
to haul out on dry land.
- 276. But a herd of hundreds
of quarrelsome mothers,
- 277. some weighing almost a tonne,
is not an ideal nursery.
- 278. Walruses on land stick together
for good reason.
- 279. Polar bears.
- 280. A full grown male walrus is gigantic,
- 281. too big for even a polar bear to tackle.
- 282. So the bear is looking
for a walrus baby.
- 283. The scent of the bear
spreads alarm through the colony.
- 284. The walruses retreat into the sea.
- 285. The bear knows it won't be able
to catch them there.
- 286. But she too has young ones to feed.
- 287. What is a mother to do?
- 288. A mother walrus still needs
to find a place
- 289. where her young can rest.
- 290. A melting iceberg might do,
- 291. but she is not the first
to find this one.
- 292. Suitable places are already taken.
- 293. Other mothers don't want to share.
- 294. They, too, need a patch of ice
where they can protect their young.
- 295. A desperate mother has no choice
but to barge her way in.
- 296. So this time everyone loses.
- 297. Finding the right place
on these melting shores
- 298. gets harder and harder.
- 299. Solving these problems together
helps create a bond so strong
- 300. that the mother will stay in contact
with her young for the rest of her life.
- 301. But who knows now
what their future will be.
- 302. As we understand more
about the complexity
- 303. of the lives of sea creatures,
- 304. so we begin to appreciate
the fragility of their home.
- 305. Our blue planet.
- 306. Next time.
- 307. The deep.
- 308. A world richer
than we ever though possible,
- 309. where creatures thrive,
- 310. in the most extreme conditions on Earth.