1 00:00:25,859 --> 00:00:28,528 Of all the wonderful places in the world, 2 00:00:28,654 --> 00:00:32,616 one continent holds more riches than any other 3 00:00:40,707 --> 00:00:44,795 It covers almost a third of the land on Earth. 4 00:00:46,546 --> 00:00:50,050 In the south stand vast forests. 5 00:00:57,266 --> 00:00:58,850 And to the north... 6 00:01:03,563 --> 00:01:06,775 ...lies an immense frozen wilderness. 7 00:01:10,279 --> 00:01:13,824 Much of the centre is dominated by deserts. 8 00:01:18,662 --> 00:01:20,789 And at its heart 9 00:01:20,914 --> 00:01:23,709 are the world's highest mountains. 10 00:01:32,217 --> 00:01:34,803 Off the coast of this continent 11 00:01:34,928 --> 00:01:38,432 stretch the richest seas on Earth. 12 00:01:41,893 --> 00:01:43,478 And that's not all. 13 00:01:43,603 --> 00:01:46,982 This is the most populous place on the planet. 14 00:01:51,069 --> 00:01:54,489 Here, animals live alongside humans 15 00:01:54,614 --> 00:01:57,242 in the most remarkable ways. 16 00:02:06,418 --> 00:02:08,587 If you think you've seen the best the natural world 17 00:02:08,712 --> 00:02:11,798 has to offer, think again. 18 00:02:11,923 --> 00:02:16,094 There's nowhere else on Earth with so many untold stories. 19 00:02:17,471 --> 00:02:20,432 Welcome, then, to Asia. 20 00:02:58,345 --> 00:03:02,307 Asia is the largest continent on Earth. 21 00:03:04,518 --> 00:03:08,939 With a coastline over 100,000 miles long, 22 00:03:09,064 --> 00:03:11,900 it's surrounded by three oceans 23 00:03:12,025 --> 00:03:14,694 and 21 seas. 24 00:03:19,825 --> 00:03:22,828 Its waters stretch from Arabia, 25 00:03:22,953 --> 00:03:26,498 through the Indian Ocean and Southeast Asia, 26 00:03:26,623 --> 00:03:29,000 to the edge of the Pacific. 27 00:03:36,466 --> 00:03:37,509 Connected by 28 00:03:37,634 --> 00:03:40,387 some of the world's most powerful currents... 29 00:03:41,930 --> 00:03:45,851 ...these seas are the richest on the planet. 30 00:04:02,367 --> 00:04:05,662 And the animals in Asia's oceans 31 00:04:05,787 --> 00:04:09,166 are as spectacular as they are diverse. 32 00:04:29,895 --> 00:04:32,522 In the warm waters of the Western Pacific 33 00:04:32,647 --> 00:04:34,941 lives a dramatic little fish 34 00:04:35,066 --> 00:04:38,487 with pouting lips and dazzling stripes... 35 00:04:43,033 --> 00:04:45,911 ...the flamboyant Moorish idol. 36 00:04:52,417 --> 00:04:54,961 This one is looking for a partner. 37 00:04:58,548 --> 00:05:02,010 Moorish idols normally breed in pairs. 38 00:05:07,015 --> 00:05:08,600 But here, they do something 39 00:05:08,725 --> 00:05:11,895 that no others of their species do. 40 00:05:17,859 --> 00:05:20,862 They congregate in huge numbers... 41 00:05:22,906 --> 00:05:26,409 ...before swimming away from the reef to spawn. 42 00:05:36,336 --> 00:05:39,673 But so many fish attract attention. 43 00:05:57,482 --> 00:05:59,401 A grey reef shark... 44 00:06:02,612 --> 00:06:04,906 ...and it's not alone. 45 00:06:10,954 --> 00:06:15,542 With so many hiding places, there is safety on the reef... 46 00:06:18,962 --> 00:06:22,132 ...but they must get out past the sharks. 47 00:06:47,490 --> 00:06:50,452 Finally, they make a break for it. 48 00:06:58,752 --> 00:07:00,670 Now in open water, 49 00:07:00,795 --> 00:07:03,256 they can swim into the blue. 50 00:07:11,473 --> 00:07:13,350 But they've been spotted. 51 00:07:25,612 --> 00:07:27,906 A few sharks can be avoided... 52 00:07:33,495 --> 00:07:35,914 ...but hundreds are a different matter. 53 00:07:51,096 --> 00:07:52,806 To have any chance of survival, 54 00:07:52,931 --> 00:07:56,184 they must stay in a tight group. 55 00:07:58,311 --> 00:08:00,980 The sharks try to split them up... 56 00:08:02,232 --> 00:08:04,651 ...and pick them off. 57 00:08:46,818 --> 00:08:50,405 After two hours of chasing... 58 00:08:50,530 --> 00:08:53,199 ...only the strongest are left. 59 00:09:05,253 --> 00:09:08,590 The few survivors swim in tight spirals, 60 00:09:08,715 --> 00:09:11,468 desperate to avoid capture. 61 00:09:27,317 --> 00:09:29,903 The sharks, tired and full, 62 00:09:30,028 --> 00:09:33,323 one by one abandon the chase... 63 00:09:49,339 --> 00:09:51,633 ...until only the luckiest 64 00:09:51,758 --> 00:09:55,094 and fittest Moorish idols survive. 65 00:10:03,061 --> 00:10:06,606 No-one knows exactly where they spawn. 66 00:10:09,150 --> 00:10:12,695 But the developing young are carried away to safety 67 00:10:12,821 --> 00:10:14,322 by the currents. 68 00:10:25,250 --> 00:10:27,669 From the Western Pacific 69 00:10:27,794 --> 00:10:31,923 comes one of the most powerful currents in the world, 70 00:10:32,048 --> 00:10:35,218 the Indonesian Throughflow. 71 00:10:39,347 --> 00:10:42,725 It sweeps between Borneo and Sulawesi 72 00:10:42,851 --> 00:10:45,436 and into the Flores Sea, 73 00:10:45,562 --> 00:10:49,899 where it hits Indonesia's Lesser Sunda Islands. 74 00:10:58,157 --> 00:11:01,619 Here, water is forced between the islands 75 00:11:01,744 --> 00:11:06,416 at a rate of 15 billion litres a second. 76 00:11:16,801 --> 00:11:19,596 And this produces some of the world's 77 00:11:19,721 --> 00:11:21,347 most intense currents... 78 00:11:22,807 --> 00:11:24,475 ...and whirlpools. 79 00:11:47,457 --> 00:11:51,920 Off the island of Komodo, the water is funnel led 80 00:11:52,045 --> 00:11:53,963 into fast-flowing torrents 81 00:11:54,088 --> 00:11:56,341 which concentrate the plankton it carries... 82 00:12:03,431 --> 00:12:04,891 ...providing food... 83 00:12:07,018 --> 00:12:08,686 ...for giants. 84 00:12:12,065 --> 00:12:13,942 Manta rays. 85 00:12:20,865 --> 00:12:23,743 With a wingspan of up to five metres, 86 00:12:23,868 --> 00:12:27,872 these mantas exploit the powerful currents. 87 00:12:32,543 --> 00:12:36,381 They feed by filtering plankton from the water. 88 00:12:45,264 --> 00:12:49,227 Such a feast makes this an excellent place 89 00:12:49,352 --> 00:12:51,187 to produce young. 90 00:13:10,498 --> 00:13:13,668 When the adults need a break, they head off 91 00:13:13,793 --> 00:13:16,671 for a bit of pampering. 92 00:13:22,677 --> 00:13:26,806 Out of the main flow are cleaning stations... 93 00:13:27,890 --> 00:13:31,019 ...staffed by hundreds of butterfly fish. 94 00:13:34,856 --> 00:13:38,276 The cleaners remove parasites and dead skin 95 00:13:38,401 --> 00:13:41,070 and get a meal in exchange for their services. 96 00:13:48,077 --> 00:13:49,871 And the mantas get 97 00:13:49,996 --> 00:13:53,916 a welcome break from the ripping currents. 98 00:13:56,419 --> 00:13:57,795 Refreshed, 99 00:13:57,920 --> 00:14:00,798 they can go back to feeding. 100 00:14:04,677 --> 00:14:08,890 As the Indonesian Throughflow continues, 101 00:14:09,015 --> 00:14:12,643 one branch flows past Bali... 102 00:14:12,769 --> 00:14:14,979 ...to Java... 103 00:14:15,104 --> 00:14:19,525 ...and some of the richest coastal forests on Earth. 104 00:14:28,826 --> 00:14:30,745 Mangroves. 105 00:14:39,545 --> 00:14:44,592 These are places where nothing is as you might expect. 106 00:14:47,845 --> 00:14:50,223 Trees grow in the sea... 107 00:14:54,685 --> 00:14:57,605 ...and fish live on land. 108 00:15:02,527 --> 00:15:05,488 A dusky-gilled mudskipper... 109 00:15:07,907 --> 00:15:10,326 ...only five centimetres long, 110 00:15:10,451 --> 00:15:13,079 but a master of these swamps. 111 00:15:19,127 --> 00:15:21,170 As long as they can stay wet, 112 00:15:21,295 --> 00:15:23,965 they can absorb oxygen from the air, 113 00:15:24,090 --> 00:15:28,219 and they spend most of their life out of water. 114 00:15:31,430 --> 00:15:35,893 Joints in their pectoral fins enable them to walk... 115 00:15:37,937 --> 00:15:39,355 ...and they can leap 116 00:15:39,480 --> 00:15:41,941 with a flick of their tail. 117 00:15:44,861 --> 00:15:48,739 This one is seeking a mate with whom to start a family. 118 00:15:50,283 --> 00:15:53,327 But first, he needs to dig 119 00:15:53,452 --> 00:15:55,371 a breeding burrow. 120 00:16:12,013 --> 00:16:13,931 Mudskippers will shift 121 00:16:14,056 --> 00:16:16,684 up to 300 times their body weight in mud... 122 00:16:18,394 --> 00:16:20,813 ...one mouthful at a time. 123 00:16:24,942 --> 00:16:26,903 Tiring work! 124 00:16:40,249 --> 00:16:42,710 With the dirty job done, 125 00:16:42,835 --> 00:16:45,004 it's time to find a female. 126 00:16:50,551 --> 00:16:54,555 But the mangroves are full of obstacles. 127 00:16:58,226 --> 00:17:00,686 A special set of grasping belly fins, 128 00:17:00,811 --> 00:17:02,730 however, enables skippers 129 00:17:02,855 --> 00:17:05,358 to become climbers. 130 00:17:16,160 --> 00:17:18,204 And when there is a dead end... 131 00:17:23,918 --> 00:17:25,086 ...a mudskipper 132 00:17:25,211 --> 00:17:28,089 simply skips across the water's surface, 133 00:17:28,214 --> 00:17:30,091 a metre at a time. 134 00:17:43,729 --> 00:17:45,690 What's this? 135 00:17:48,067 --> 00:17:49,986 An open arena... 136 00:17:52,405 --> 00:17:55,491 ...full of females. 137 00:18:01,539 --> 00:18:03,332 Excellent! 138 00:18:07,128 --> 00:18:11,299 But there are also other males here looking for partners. 139 00:18:19,682 --> 00:18:22,852 To win a female, they must duel. 140 00:18:29,400 --> 00:18:31,694 But no-one is backing down. 141 00:18:57,053 --> 00:19:01,474 Victory, and the opponent beats a hasty retreat. 142 00:19:07,730 --> 00:19:09,815 And it looks like this male... 143 00:19:11,108 --> 00:19:13,110 ...has caught someone's eye. 144 00:19:28,000 --> 00:19:31,962 A quick wave should seal the deal. 145 00:19:38,511 --> 00:19:40,429 It's a date. 146 00:19:44,183 --> 00:19:46,811 They head back to his place... 147 00:19:48,604 --> 00:19:51,690 ...ready to start a family of their own. 148 00:20:08,040 --> 00:20:10,251 Mangrove forests are essential 149 00:20:10,376 --> 00:20:13,421 for the survival of Asia's mudskippers... 150 00:20:14,713 --> 00:20:17,591 ...and trap four times more carbon 151 00:20:17,716 --> 00:20:20,928 than forests growing on dry land. 152 00:20:24,807 --> 00:20:27,893 Today, Southeast Asia holds a third 153 00:20:28,018 --> 00:20:31,105 of what is left of these precious forests... 154 00:20:33,149 --> 00:20:37,736 ...adding clean, fresh water to the Indonesian Throughflow 155 00:20:37,862 --> 00:20:39,697 as it travels. 156 00:20:45,911 --> 00:20:48,497 Sweeping away from Indonesia, 157 00:20:48,622 --> 00:20:53,669 the current heads west across the vast Indian Ocean... 158 00:20:59,717 --> 00:21:03,012 ...carrying with it a whole host... 159 00:21:03,137 --> 00:21:05,347 ...of drifters. 160 00:21:18,903 --> 00:21:22,907 And some objects provide entertainment 161 00:21:23,032 --> 00:21:25,910 for one of Asia's giants. 162 00:21:35,753 --> 00:21:37,129 A baby sperm whale 163 00:21:37,254 --> 00:21:42,968 plays with a mangrove seed, so practising his coordination. 164 00:21:47,181 --> 00:21:48,224 He produces 165 00:21:48,349 --> 00:21:52,770 pulses of high-frequency sound from his large head - 166 00:21:52,895 --> 00:21:55,231 sonar that will eventually enable him 167 00:21:55,356 --> 00:21:58,567 to locate prey in the black depths. 168 00:22:00,694 --> 00:22:02,530 And zeroing in 169 00:22:02,655 --> 00:22:06,242 on a tiny seed is great practice for doing so. 170 00:22:16,877 --> 00:22:18,921 When you're as big as this, 171 00:22:19,046 --> 00:22:21,465 grabbing something the size of a pencil 172 00:22:21,590 --> 00:22:23,133 is not easy. 173 00:22:26,470 --> 00:22:30,474 With play over, it's time to get back to the family. 174 00:22:36,397 --> 00:22:39,316 The grown-ups are taking a nap. 175 00:22:42,152 --> 00:22:45,531 It's thought that the reason they sleep upright 176 00:22:45,656 --> 00:22:47,157 is to make it easy 177 00:22:47,283 --> 00:22:49,159 to bob up for air. 178 00:22:59,670 --> 00:23:02,548 The calf is keen to join in. 179 00:23:04,008 --> 00:23:06,719 But it's not as easy as it looks. 180 00:23:18,314 --> 00:23:21,150 Staying vertical takes practice. 181 00:23:29,575 --> 00:23:32,161 And when you get the hang of that... 182 00:23:34,038 --> 00:23:35,331 ...the next challenge... 183 00:23:35,456 --> 00:23:37,416 ...Is buoyancy. 184 00:23:45,883 --> 00:23:48,469 Holding just the right amount of breath 185 00:23:48,594 --> 00:23:50,763 is an art. 186 00:24:00,439 --> 00:24:02,483 Too little... 187 00:24:02,608 --> 00:24:04,401 ...and you sink. 188 00:24:12,743 --> 00:24:16,330 The adults tenderly correct his mistakes. 189 00:24:17,956 --> 00:24:20,042 He still has a lot to learn. 190 00:24:24,630 --> 00:24:27,299 In his 70-year lifespan, 191 00:24:27,424 --> 00:24:31,178 he will explore much of the Indian Ocean. 192 00:24:38,602 --> 00:24:43,273 From here, the Indonesian Throughflow continues west. 193 00:24:46,026 --> 00:24:51,240 But a very different kind of traffic is moving northwards. 194 00:24:57,496 --> 00:24:59,081 Shipping. 195 00:25:02,918 --> 00:25:07,089 Major international cargo lanes run from the Indian Ocean 196 00:25:07,214 --> 00:25:11,719 into the Red Sea, which divides Asia from Africa. 197 00:25:16,598 --> 00:25:20,436 At its northern end is the Suez Canal. 198 00:25:28,777 --> 00:25:31,572 One third of the world's container freight 199 00:25:31,697 --> 00:25:35,784 travels along it and emerges into the Mediterranean... 200 00:25:39,163 --> 00:25:42,291 ...one of the planet's most polluted seas. 201 00:25:53,218 --> 00:25:56,388 Here, on Asia's westernmost coastline, 202 00:25:56,513 --> 00:25:59,600 this Israeli power station discharges 203 00:25:59,725 --> 00:26:04,021 water ten degrees hotter than the surrounding sea. 204 00:26:12,362 --> 00:26:16,617 Astonishingly, this has become a refuge for one of 205 00:26:16,742 --> 00:26:19,286 the most vulnerable of species... 206 00:26:22,039 --> 00:26:24,208 ...dusky sharks. 207 00:26:36,720 --> 00:26:41,767 Mediterranean sharks are the most endangered on Earth. 208 00:26:47,439 --> 00:26:51,109 But up to 100 females come here in winter... 209 00:26:59,034 --> 00:27:00,702 ...and each one of them... 210 00:27:01,870 --> 00:27:03,789 ...Is pregnant. 211 00:27:06,458 --> 00:27:09,711 It's thought the warmth speeds up the development 212 00:27:09,837 --> 00:27:12,631 of their unborn young. 213 00:27:35,279 --> 00:27:41,785 This power station has created a shark sanctuary by accident. 214 00:27:42,953 --> 00:27:44,788 But elsewhere in Asia, 215 00:27:44,913 --> 00:27:49,418 deliberate steps are being taken to protect marine life. 216 00:27:54,464 --> 00:27:57,426 Over 5,000 miles away, 217 00:27:57,551 --> 00:28:00,053 on the other side of the continent... 218 00:28:02,347 --> 00:28:08,145 ...life is booming in the unlikeliest of places. 219 00:28:17,404 --> 00:28:22,326 The tiny island of Tyuleniy in far-eastern Russia. 220 00:28:33,754 --> 00:28:36,548 A disused hunting settlement. 221 00:28:41,970 --> 00:28:46,016 Here, enormous numbers of fur seals 222 00:28:46,141 --> 00:28:48,936 were once killed annually for their skins. 223 00:28:54,191 --> 00:28:57,194 But hunting restrictions have produced 224 00:28:57,319 --> 00:28:59,529 a spectacular recovery. 225 00:29:03,200 --> 00:29:09,206 Over 100,000 northern fur seals now come here each summer. 226 00:29:09,331 --> 00:29:12,459 It's one of the largest colonies in the world. 227 00:29:24,304 --> 00:29:27,349 The beaches are jam-packed. 228 00:29:37,985 --> 00:29:42,406 Huge territorial males compete for space. 229 00:29:50,580 --> 00:29:53,917 It's dangerous for the tiny pups, which weigh 230 00:29:54,042 --> 00:29:58,130 just a fiftieth of the adult bulls. 231 00:30:02,676 --> 00:30:05,345 The aggressive males are only focused 232 00:30:05,470 --> 00:30:07,431 on the next challenge. 233 00:30:13,103 --> 00:30:17,065 When fights break out, the pups are ignored. 234 00:31:21,421 --> 00:31:25,258 In the aftermath, many pups lie injured. 235 00:31:45,278 --> 00:31:48,657 Life on the beach is full of danger... 236 00:31:50,700 --> 00:31:53,036 ...but it's no safer in the sea. 237 00:32:06,967 --> 00:32:08,343 Orca. 238 00:32:13,890 --> 00:32:19,437 Fur seals returning from fishing must run the gauntlet. 239 00:32:28,405 --> 00:32:30,991 But these orca are specialists... 240 00:32:35,370 --> 00:32:39,166 ...ramming and tail-slapping to stun their prey. 241 00:32:53,763 --> 00:32:56,349 And when their victim has been disabled... 242 00:32:58,643 --> 00:33:00,478 ...they drown it. 243 00:33:21,708 --> 00:33:25,170 Many pups are left as orphans. 244 00:33:31,009 --> 00:33:33,178 But enough will survive to support 245 00:33:33,303 --> 00:33:36,598 this now healthy population of northern fur seals. 246 00:33:44,648 --> 00:33:47,359 This richness in Asia's shallow seas 247 00:33:47,484 --> 00:33:52,155 can also be found in some of its deepest waters. 248 00:34:04,960 --> 00:34:06,169 Every night, 249 00:34:06,294 --> 00:34:09,839 billions of creatures travel up from the abyss. 250 00:34:10,924 --> 00:34:15,512 It's the largest regular movement of life on the planet. 251 00:34:25,981 --> 00:34:27,440 Strange life forms 252 00:34:27,565 --> 00:34:31,236 come up to feed in the surface waters... 253 00:34:36,324 --> 00:34:40,620 ...among them jelly-like salps, which have tiny crustaceans 254 00:34:40,745 --> 00:34:43,623 living inside their bodies. 255 00:34:53,383 --> 00:34:58,471 As dawn arrives, they return to the safety of the deep. 256 00:35:02,934 --> 00:35:06,771 But some creatures, gathering in the Sea of Japan, 257 00:35:06,896 --> 00:35:10,150 are about to embark on a one-way trip 258 00:35:10,275 --> 00:35:13,528 out of the depths, never to return. 259 00:35:21,036 --> 00:35:23,288 Firefly squid. 260 00:35:26,624 --> 00:35:29,794 They live for just 12 months. 261 00:35:34,257 --> 00:35:35,967 It's thought that they use 262 00:35:36,092 --> 00:35:38,636 their blue bioluminescent lights 263 00:35:38,762 --> 00:35:40,805 to confuse predators... 264 00:35:41,890 --> 00:35:45,352 ...and their green lights to communicate with one another. 265 00:35:47,103 --> 00:35:50,106 No other deep-sea animal can see green. 266 00:35:50,231 --> 00:35:53,860 It's the squids' own secret code. 267 00:35:57,697 --> 00:36:00,950 Some quarter of a billion females 268 00:36:01,076 --> 00:36:02,702 are heading to the surface. 269 00:36:18,385 --> 00:36:23,723 In the shallows, they lay thousands of eggs in strings... 270 00:36:25,100 --> 00:36:28,311 ...the final act of their short lives. 271 00:36:41,408 --> 00:36:45,787 With this done, their bodies are programmed to die. 272 00:36:57,090 --> 00:37:00,093 Here, on the north coast of Japan... 273 00:37:01,136 --> 00:37:04,347 ...they wash up on the beaches of Toyama Bay. 274 00:37:35,086 --> 00:37:39,841 Their lights fade as life drifts away. 275 00:37:46,139 --> 00:37:47,932 Their eggs, however... 276 00:37:50,852 --> 00:37:53,271 ...are beginning to hatch. 277 00:38:04,449 --> 00:38:08,328 Sinking into the vast darkness of the deep sea, 278 00:38:08,453 --> 00:38:11,706 they won't return to shallow water for a year, 279 00:38:11,831 --> 00:38:15,460 when it will be their turn to lay eggs... 280 00:38:15,585 --> 00:38:17,378 ...and then die. 281 00:38:25,136 --> 00:38:28,806 2,000 miles south, in the Western Pacific, 282 00:38:28,932 --> 00:38:33,019 lie wide expanses of shallow seas 283 00:38:33,144 --> 00:38:37,649 around the Philippines, Malaysia and Indonesia... 284 00:38:41,694 --> 00:38:44,906 ...the so-called Coral Triangle. 285 00:39:02,632 --> 00:39:07,637 Here, there are more abundant coral reefs than anywhere else. 286 00:39:07,762 --> 00:39:14,018 It's the richest concentration of marine life on the planet. 287 00:39:20,817 --> 00:39:25,113 Three quarters of the world's coral species are found here... 288 00:39:28,241 --> 00:39:29,784 ...and over 3,000 289 00:39:29,909 --> 00:39:32,078 species of fish. 290 00:39:33,413 --> 00:39:38,585 It's every bit as diverse as the Amazon rainforest. 291 00:39:43,548 --> 00:39:48,553 Coral reefs truly are the ocean's bustling cities. 292 00:39:51,848 --> 00:39:53,558 Many residents have evolved 293 00:39:53,683 --> 00:39:55,351 ingenious ways of solving 294 00:39:55,476 --> 00:39:58,605 the problems of living in such close quarters. 295 00:40:03,693 --> 00:40:07,739 But some appear to be completely defenceless. 296 00:40:18,124 --> 00:40:20,877 Meet the sea bunny. 297 00:40:24,380 --> 00:40:27,383 Just a few centimetres long, this tiny sea slug 298 00:40:27,508 --> 00:40:30,261 has no shell for protection... 299 00:40:35,058 --> 00:40:37,602 ...no eyes to spot danger... 300 00:40:41,981 --> 00:40:43,858 ...and travels... 301 00:40:43,983 --> 00:40:46,527 ...at a snail's pace. 302 00:40:50,865 --> 00:40:53,076 It's looking for food. 303 00:40:57,705 --> 00:41:00,833 What appear to be its ears 304 00:41:00,958 --> 00:41:04,337 are, in fact, finely tuned chemical sensors 305 00:41:04,462 --> 00:41:06,506 that enable it to "smell" 306 00:41:06,631 --> 00:41:08,883 its way to its next meal. 307 00:41:23,356 --> 00:41:27,777 But on the reef, predators are everywhere. 308 00:41:32,865 --> 00:41:34,909 When you can't see... 309 00:41:37,954 --> 00:41:40,581 ...it can be hard to avoid trouble. 310 00:41:45,878 --> 00:41:50,967 Alien-like beasts patrol the nooks and crannies of the reef. 311 00:42:17,160 --> 00:42:21,038 This one filters its food from the water... 312 00:42:21,164 --> 00:42:24,792 ...and is no threat to the sea bunny. 313 00:42:29,297 --> 00:42:33,593 But not everything here is quite so harmless. 314 00:42:35,678 --> 00:42:39,432 The moray eel, powerful and fast... 315 00:42:43,853 --> 00:42:48,107 ...but apparently not keen on slug for dinner. 316 00:42:56,574 --> 00:42:58,993 A scorpion fish, one of the reef's 317 00:42:59,118 --> 00:43:01,162 most deadly inhabitants. 318 00:43:03,915 --> 00:43:07,543 Extravagantly camouflaged, it waits for prey 319 00:43:07,668 --> 00:43:09,504 to come close... 320 00:43:17,220 --> 00:43:20,306 ...then swallows them whole. 321 00:43:36,531 --> 00:43:40,076 But the sea bunny just walks all over him. 322 00:43:50,211 --> 00:43:53,130 And now it's headed straight for 323 00:43:53,256 --> 00:43:55,675 a deadly poisonous blue sponge. 324 00:43:58,135 --> 00:44:03,099 Blind and hungry, it's about to take a bite. 325 00:44:11,649 --> 00:44:15,444 It seems that its luck has finally run out. 326 00:44:19,824 --> 00:44:23,703 But no - this is actually its favourite food. 327 00:44:25,621 --> 00:44:27,415 It's immune to the poison... 328 00:44:28,833 --> 00:44:31,168 ...and by eating the sponge, 329 00:44:31,294 --> 00:44:34,922 the sea bunny has made itself toxic to predators. 330 00:44:38,092 --> 00:44:41,012 No wonder it's untouchable. 331 00:44:44,348 --> 00:44:47,643 As long as it can maintain its blue sponge diet, 332 00:44:47,768 --> 00:44:49,770 the sea bunny will be protected 333 00:44:49,896 --> 00:44:52,523 against the dangers of the reef. 334 00:44:59,906 --> 00:45:03,159 With so many complex survival strategies... 335 00:45:05,411 --> 00:45:08,539 ...life for predators on the Coral Triangle 336 00:45:08,664 --> 00:45:11,125 can require complex tactics. 337 00:45:19,967 --> 00:45:22,970 This snake, a black-banded sea krait... 338 00:45:24,180 --> 00:45:27,850 ...has venom ten times stronger than a cobra... 339 00:45:33,356 --> 00:45:35,066 ...a forked tongue that enables it 340 00:45:35,191 --> 00:45:39,028 to sniff out prey underwater... 341 00:45:40,446 --> 00:45:42,907 ...and a flexible body, 342 00:45:43,032 --> 00:45:45,076 so it can squeeze into crevices 343 00:45:45,201 --> 00:45:47,912 on the reef to look for prey. 344 00:45:49,330 --> 00:45:51,207 A formidable killer, it would seem. 345 00:45:58,130 --> 00:46:02,426 Yet hunting fast prey is not one of its abilities. 346 00:46:06,472 --> 00:46:09,141 It's slow, with poor eyesight - 347 00:46:09,266 --> 00:46:12,353 hardly the deadliest of assassins. 348 00:46:15,690 --> 00:46:18,734 If only it were fast and agile... 349 00:46:21,529 --> 00:46:23,823 ...like these bluefin trevally. 350 00:46:31,539 --> 00:46:34,000 They rely on sheer speed 351 00:46:34,125 --> 00:46:35,793 to catch their prey. 352 00:46:46,262 --> 00:46:48,055 Unlike the snake, 353 00:46:48,180 --> 00:46:52,184 they're too big to get between the arms of the coral. 354 00:46:56,480 --> 00:46:59,358 But these two struggling species have found 355 00:46:59,483 --> 00:47:01,068 a solution. 356 00:47:09,160 --> 00:47:11,287 They work as a team. 357 00:47:26,010 --> 00:47:28,137 The trevally leads... 358 00:47:32,308 --> 00:47:35,478 ...indicating places where prey could be hiding... 359 00:47:41,275 --> 00:47:44,737 ...which the snake then investigates. 360 00:47:55,998 --> 00:47:57,917 As they roam the reef, 361 00:47:58,042 --> 00:48:01,128 they're joined by more trevally... 362 00:48:04,965 --> 00:48:06,884 ...and more snakes. 363 00:48:16,352 --> 00:48:19,939 Soon, they are an army. 364 00:48:34,286 --> 00:48:37,414 The trevally find a target. 365 00:48:43,003 --> 00:48:45,464 The shakes head in... 366 00:48:47,550 --> 00:48:51,595 ...and the trevally cover the escape routes. 367 00:48:59,270 --> 00:49:01,730 There's nowhere left to hide. 368 00:49:10,447 --> 00:49:12,616 The trevally catch the fish 369 00:49:12,741 --> 00:49:14,326 that are flushed out... 370 00:49:20,791 --> 00:49:22,459 ...and the snake eats 371 00:49:22,585 --> 00:49:25,045 anything left inside. 372 00:49:39,018 --> 00:49:40,311 Each species 373 00:49:40,436 --> 00:49:42,605 benefits from the partnership. 374 00:49:47,359 --> 00:49:49,278 The hunts are so successful 375 00:49:49,403 --> 00:49:52,865 that they attract hundreds of trevally and snakes. 376 00:50:14,970 --> 00:50:18,349 This behaviour is extremely rare 377 00:50:18,474 --> 00:50:22,186 and has only been seen in Asia's Coral Triangle. 378 00:50:24,146 --> 00:50:25,856 Innovation and teamwork 379 00:50:25,981 --> 00:50:28,108 are critical to success 380 00:50:28,234 --> 00:50:30,736 in these competitive waters. 381 00:50:42,998 --> 00:50:46,710 These relationships and strategies, 382 00:50:46,835 --> 00:50:49,630 developed over millennia, are a consequence 383 00:50:49,755 --> 00:50:53,801 of the extraordinary richness of Asia's seas. 384 00:50:57,471 --> 00:51:01,392 And whilst our influence is now not far away, 385 00:51:01,517 --> 00:51:05,688 Asia's oceans still remain a world of wonder, 386 00:51:05,813 --> 00:51:10,442 offering spectacles not found anywhere else on Earth. 387 00:51:28,335 --> 00:51:30,671 The Asia team explored 388 00:51:30,796 --> 00:51:34,383 many of the continent's 21 seas. 389 00:51:36,051 --> 00:51:38,220 They spent thousands of hours 390 00:51:38,345 --> 00:51:42,308 underwater, filming the spectacular diversity of life. 391 00:51:54,403 --> 00:51:57,573 But their biggest challenge was getting up close 392 00:51:57,698 --> 00:52:00,701 with some of the most powerful currents on earth. 393 00:52:04,330 --> 00:52:07,333 The Indonesian Throughflow 394 00:52:07,458 --> 00:52:09,460 carries ten times more water 395 00:52:09,585 --> 00:52:12,504 than all the world's rivers combined. 396 00:52:21,472 --> 00:52:23,766 The tide has to make its way 397 00:52:23,891 --> 00:52:26,185 from the Pacific to the Indian, 398 00:52:26,310 --> 00:52:28,312 and that's a huge amount of water. 399 00:52:28,437 --> 00:52:31,148 And as it does that, it gets squeezed through 400 00:52:31,273 --> 00:52:33,734 these islands, which creates intense currents 401 00:52:33,859 --> 00:52:36,403 but also brings an incredible amount of life. 402 00:52:39,281 --> 00:52:40,866 The team want to capture 403 00:52:40,991 --> 00:52:44,370 this immense power up close, 404 00:52:44,495 --> 00:52:48,582 but the fast currents are making filming difficult. 405 00:52:52,336 --> 00:52:55,714 For their first attempt, they use a pole-mounted camera. 406 00:53:02,805 --> 00:53:06,642 But getting the boat into position is almost impossible. 407 00:53:08,811 --> 00:53:10,979 We're fighting a losing battle. 408 00:53:11,105 --> 00:53:12,064 We'll drop it. 409 00:53:12,189 --> 00:53:14,775 Let's go back to the main boat. 410 00:53:14,900 --> 00:53:17,861 David thinks he has a solution, 411 00:53:17,986 --> 00:53:19,738 but it's radical. 412 00:53:19,863 --> 00:53:23,617 He's going to get in the water himself, 413 00:53:23,742 --> 00:53:27,996 using a floating camera rig to film inside the vortex. 414 00:53:29,415 --> 00:53:31,208 We'll see the swirling water, 415 00:53:31,333 --> 00:53:34,503 literally the opening of the funnel of the whirlpool. 416 00:53:34,628 --> 00:53:37,631 That's what I want. It's like the epic shot. 417 00:53:38,882 --> 00:53:40,467 If the shot works, 418 00:53:40,592 --> 00:53:41,677 it's going to be amazing. 419 00:53:41,802 --> 00:53:44,596 It's going to really tell the story of the currents nicely. 420 00:53:47,182 --> 00:53:49,435 So I think what we have to do is put David 421 00:53:49,560 --> 00:53:52,688 up current, initially, but close-ish in to the island, 422 00:53:52,813 --> 00:53:54,940 to get those swirls as you come past. 423 00:53:55,065 --> 00:53:56,191 What's the normal advice 424 00:53:56,316 --> 00:53:58,235 - for divers here? - Normally, we'll actually jump 425 00:53:58,360 --> 00:54:00,237 right next to the island, where there's no current. 426 00:54:00,362 --> 00:54:02,948 There you stay out of the current entirely, 427 00:54:03,073 --> 00:54:04,783 which is the opposite to what you're gonna be doing! 428 00:54:04,908 --> 00:54:05,826 - Yes. - OK, yeah. 429 00:54:05,951 --> 00:54:08,203 This challenge is unlike 430 00:54:08,328 --> 00:54:10,914 anything David has faced in 30 years of film-making. 431 00:54:13,667 --> 00:54:15,461 I'm going to add two life jackets 432 00:54:15,586 --> 00:54:17,045 to the camera rig, 433 00:54:17,171 --> 00:54:19,965 and, you know, if I start to get sucked down, 434 00:54:20,090 --> 00:54:22,551 I'm going to just hang on to that. 435 00:54:27,222 --> 00:54:30,350 The key to staying safe will be buoyancy. 436 00:54:30,476 --> 00:54:32,686 Yeah, I don't know if I can get this third one on. 437 00:54:32,811 --> 00:54:35,105 Three life jackets should resist 438 00:54:35,230 --> 00:54:36,690 the pull of the whirlpools. 439 00:54:36,815 --> 00:54:38,233 It's not that bad. 440 00:54:40,027 --> 00:54:43,071 - What do you think? Money? - Yeah. 441 00:54:44,615 --> 00:54:46,074 DAVID ATTENBOROUGH; The team decide 442 00:54:46,200 --> 00:54:49,661 to dive on the rising tide, when the currents are weaker. 443 00:54:54,291 --> 00:54:56,710 I think I'm plenty floaty! 444 00:54:58,670 --> 00:55:01,048 David's home-made protection 445 00:55:01,173 --> 00:55:03,133 is holding up well. 446 00:55:10,724 --> 00:55:13,143 The current is running fast, 447 00:55:13,268 --> 00:55:15,187 but the whirlpools aren't forming. 448 00:55:16,605 --> 00:55:18,440 - David, nothing? - Nothing. 449 00:55:18,565 --> 00:55:19,858 - Nothing at all? - Like, I... 450 00:55:19,983 --> 00:55:21,735 I feel the current, and I, like, 451 00:55:21,860 --> 00:55:24,738 I don't see any, like, whirlpools, 452 00:55:24,863 --> 00:55:27,658 bubbles, hardly anything in the water. 453 00:55:27,783 --> 00:55:31,119 - Do you want picking up? - Yeah. 454 00:55:33,539 --> 00:55:35,374 It seems that if David 455 00:55:35,499 --> 00:55:37,459 is to get his shots... 456 00:55:38,961 --> 00:55:42,965 ...he'll have to brave the much faster falling tide. 457 00:55:53,517 --> 00:55:55,060 Preparation... 458 00:55:55,185 --> 00:55:57,646 ...will be key to success. 459 00:56:07,072 --> 00:56:09,866 Whirlpools only last a few seconds, 460 00:56:09,992 --> 00:56:11,868 So to get in the right position, 461 00:56:11,994 --> 00:56:15,080 the team needs eyes in the sky. 462 00:56:18,458 --> 00:56:19,710 Drone's in the air. 463 00:56:19,835 --> 00:56:21,962 OK, copy, copy. What do you guys see? 464 00:56:22,087 --> 00:56:23,672 The current looks strong 465 00:56:23,797 --> 00:56:25,549 on that eastern edge of the island. 466 00:56:25,674 --> 00:56:26,842 If you can spot 467 00:56:26,967 --> 00:56:29,928 good places where the whirlpools are cropping up... 468 00:56:32,472 --> 00:56:34,850 Mark, Mark, the swirl's forming 469 00:56:34,975 --> 00:56:37,352 - on the edge you're at. - Right, thanks, mate. 470 00:56:37,477 --> 00:56:39,563 Look, we've got some... 471 00:56:39,688 --> 00:56:41,523 ...definitely some forming here. 472 00:56:43,358 --> 00:56:44,818 David must get to 473 00:56:44,943 --> 00:56:47,237 the whirlpools before they dissipate. 474 00:56:49,323 --> 00:56:51,241 - Is this a good spot? - Yeah. 475 00:56:51,366 --> 00:56:52,743 - Yeah, I call it right here. - OK. 476 00:56:52,868 --> 00:56:55,287 Clear to go. 477 00:57:02,878 --> 00:57:05,464 You're going to get sucked in pretty quickly. 478 00:57:07,466 --> 00:57:09,468 Behind you, David. 479 00:57:12,679 --> 00:57:14,848 Mark is ready with a throw rope 480 00:57:14,973 --> 00:57:16,099 in case of trouble. 481 00:57:23,357 --> 00:57:25,359 You OK? 482 00:57:27,736 --> 00:57:29,112 Do you want the rope? 483 00:57:30,864 --> 00:57:33,158 He's OK. He wants to carry on. 484 00:57:35,535 --> 00:57:38,580 David's commitment is paying off. 485 00:57:41,083 --> 00:57:43,335 He's starting to get the shots. 486 00:57:57,265 --> 00:58:00,435 But the whirlpools are growing stronger. 487 00:58:10,570 --> 00:58:13,615 That is putting him right in the whirlpool zone. 488 00:58:19,454 --> 00:58:21,581 He's getting sucked in. 489 00:58:28,964 --> 00:58:31,883 All he can do now is hang on. 490 00:58:34,845 --> 00:58:37,597 OK, can we get closer to David? 491 00:58:41,017 --> 00:58:42,018 Whoa! 492 00:58:42,144 --> 00:58:46,189 At last, the whirlpool spits him out. 493 00:58:50,485 --> 00:58:51,903 David, you OK? 494 00:58:52,028 --> 00:58:53,655 Yeah. 495 00:58:55,240 --> 00:58:56,491 It's hairy. 496 00:58:56,616 --> 00:58:59,494 It's not doing anything for my nerves, let alone David's. 497 00:58:59,619 --> 00:59:01,788 It's time to get back 498 00:59:01,913 --> 00:59:03,874 into the safety of the boat. 499 00:59:05,459 --> 00:59:07,753 - OK? - Yeah. 500 00:59:07,878 --> 00:59:10,422 It had me. I could feel myself going blubble-ubble-ubble. 501 00:59:10,547 --> 00:59:12,090 - Really? - Like that, but I had enough... 502 00:59:12,215 --> 00:59:13,633 | Kinda kept my hands on the camera. 503 00:59:13,759 --> 00:59:15,719 - Yeah. - I didn't even see it coming. 504 00:59:15,844 --> 00:59:18,972 - Suddenly I was just like... - Yeah. Yeah, yeah, yeah. 505 00:59:19,097 --> 00:59:20,682 A good whirlpool, huh? 506 00:59:20,807 --> 00:59:24,853 David's plan has succeeded. 507 00:59:24,978 --> 00:59:26,104 Yeah! 508 00:59:26,229 --> 00:59:27,689 He's faced Asia's 509 00:59:27,814 --> 00:59:30,734 ripping whirlpools and captured their fierce beauty 510 00:59:30,859 --> 00:59:33,361 as never before.