1 00:00:17,620 --> 00:00:22,220 Of all the wonderful places in the world, one continent holds 2 00:00:22,220 --> 00:00:24,540 more riches than any other. 3 00:00:32,140 --> 00:00:35,500 It covers almost a third of the land on Earth. 4 00:00:37,580 --> 00:00:41,220 In the south, stand vast forests. 5 00:00:48,180 --> 00:00:49,980 And to the north... 6 00:00:54,060 --> 00:00:57,220 ..lies an immense frozen wilderness. 7 00:01:00,700 --> 00:01:03,740 Much of the centre is dominated by deserts. 8 00:01:08,500 --> 00:01:12,820 And at its heart are the world's highest mountains. 9 00:01:21,460 --> 00:01:23,900 Off the coast of this continent, 10 00:01:23,900 --> 00:01:27,380 stretch the richest seas on Earth. 11 00:01:30,620 --> 00:01:32,580 And that's not all. 12 00:01:32,580 --> 00:01:35,820 This is the most populous place on the planet. 13 00:01:39,540 --> 00:01:45,620 Here, animals live alongside humans in the most remarkable ways. 14 00:01:54,460 --> 00:01:57,700 If you think you've seen the best the natural world has to offer, 15 00:01:57,700 --> 00:01:59,300 think again. 16 00:01:59,300 --> 00:02:03,660 There's nowhere else on Earth with so many untold stories. 17 00:02:04,980 --> 00:02:07,780 Welcome then, to Asia. 18 00:02:44,300 --> 00:02:47,860 Asia is the largest continent on Earth. 19 00:02:50,100 --> 00:02:54,460 With a coastline over 100,000 miles long, 20 00:02:54,460 --> 00:02:59,540 it's surrounded by three oceans and 21 seas. 21 00:03:04,620 --> 00:03:09,500 Its waters stretch from Arabia, through the Indian Ocean 22 00:03:09,500 --> 00:03:13,260 and Southeast Asia, to the edge of the Pacific. 23 00:03:20,820 --> 00:03:24,060 Connected by some of the world's most powerful currents... 24 00:03:26,060 --> 00:03:28,900 ..these seas are the richest on the planet. 25 00:03:45,820 --> 00:03:52,420 And the animals in Asia's oceans are as spectacular as they are diverse. 26 00:04:11,780 --> 00:04:14,780 In the warm waters of the Western Pacific, 27 00:04:14,780 --> 00:04:20,260 lives a dramatic little fish, with pouting lips and dazzling stripes... 28 00:04:24,340 --> 00:04:27,420 ..the flamboyant Moorish idol. 29 00:04:33,500 --> 00:04:35,660 This one is looking for a partner. 30 00:04:39,500 --> 00:04:42,580 Moorish idols normally breed in pairs. 31 00:04:47,420 --> 00:04:51,940 But here, they do something that no others of their species do. 32 00:04:57,980 --> 00:05:00,820 They congregate in huge numbers... 33 00:05:02,620 --> 00:05:06,260 ..before swimming away from the reef, to spawn. 34 00:05:15,660 --> 00:05:19,220 But so many fish attract attention. 35 00:05:36,060 --> 00:05:38,100 A grey reef shark... 36 00:05:41,340 --> 00:05:43,060 ..and it's not alone. 37 00:05:48,820 --> 00:05:53,100 With so many hiding places, there is safety on the reef... 38 00:05:56,460 --> 00:05:59,460 ..but they must get out past the sharks. 39 00:06:23,980 --> 00:06:26,780 Finally, they make a break for it. 40 00:06:34,460 --> 00:06:38,900 Now in open water, they can swim into the blue. 41 00:06:47,140 --> 00:06:48,500 But they've been spotted. 42 00:07:00,100 --> 00:07:02,380 A few sharks can be avoided... 43 00:07:07,900 --> 00:07:10,620 ..but hundreds are a different matter. 44 00:07:25,020 --> 00:07:29,900 To have any chance of survival, they must stay in a tight group. 45 00:07:32,140 --> 00:07:33,980 The sharks try to split them up... 46 00:07:35,940 --> 00:07:37,380 ..and pick them off. 47 00:08:18,260 --> 00:08:21,860 After two hours of chasing, 48 00:08:21,860 --> 00:08:23,980 only the strongest are left. 49 00:08:35,860 --> 00:08:41,300 The few survivors swim in tight spirals, desperate to avoid capture. 50 00:08:57,100 --> 00:09:00,020 The sharks, tired and full, 51 00:09:00,020 --> 00:09:02,660 one-by-one, abandon the chase... 52 00:09:18,100 --> 00:09:23,620 ..until only the luckiest and fittest Moorish idols survive. 53 00:09:31,580 --> 00:09:34,860 No-one knows exactly where they spawn. 54 00:09:37,540 --> 00:09:42,100 But the developing young are carried away to safety by the currents. 55 00:09:52,980 --> 00:09:57,260 From the Western Pacific, comes one of the most powerful 56 00:09:57,260 --> 00:10:02,460 currents in the world - the Indonesian Throughflow. 57 00:10:06,300 --> 00:10:10,660 It sweeps between Borneo and Sulawesi, and into 58 00:10:10,660 --> 00:10:16,460 the Flores Sea, where it hits Indonesia's Lesser Sunda Islands. 59 00:10:24,420 --> 00:10:28,780 Here, water is forced between the islands at a rate 60 00:10:28,780 --> 00:10:32,140 of 15 billion litres a second. 61 00:10:42,260 --> 00:10:46,300 And this produces some of the world's most intense currents... 62 00:10:48,060 --> 00:10:49,660 ..and whirlpools. 63 00:11:11,700 --> 00:11:14,580 Off the island of Komodo, 64 00:11:14,580 --> 00:11:17,860 the water is funnelled into fast-flowing torrents, 65 00:11:17,860 --> 00:11:20,780 which concentrate the plankton it carries... 66 00:11:27,060 --> 00:11:28,420 ..providing food... 67 00:11:30,340 --> 00:11:31,700 ..for giants. 68 00:11:35,500 --> 00:11:37,060 Manta rays. 69 00:11:43,660 --> 00:11:46,700 With a wingspan of up to five metres, 70 00:11:46,700 --> 00:11:50,540 these mantas exploit the powerful currents. 71 00:11:54,580 --> 00:11:58,500 They feed by filtering plankton from the water. 72 00:12:07,260 --> 00:12:12,140 Such a feast makes this an excellent place to produce young. 73 00:12:31,340 --> 00:12:37,140 When the adults need a break, they head off for a bit of pampering. 74 00:12:42,820 --> 00:12:47,580 Out of the main flow are cleaning stations, 75 00:12:47,580 --> 00:12:51,020 staffed by hundreds of butterfly fish. 76 00:12:54,540 --> 00:12:58,100 The cleaners remove parasites and dead skin, 77 00:12:58,100 --> 00:13:01,540 and get a meal in exchange for their services. 78 00:13:07,580 --> 00:13:12,500 And the mantas get a welcome break from the ripping currents. 79 00:13:15,220 --> 00:13:19,380 Refreshed, they can go back to feeding. 80 00:13:23,340 --> 00:13:28,860 As the Indonesian Throughflow continues, one branch flows 81 00:13:28,860 --> 00:13:35,100 past Bali, to Java and some of the richest 82 00:13:35,100 --> 00:13:37,540 coastal forests on Earth... 83 00:13:46,420 --> 00:13:47,740 ..mangroves. 84 00:13:56,940 --> 00:14:01,580 These are places where nothing is as you might expect. 85 00:14:04,780 --> 00:14:06,940 Trees grow in the sea... 86 00:14:11,140 --> 00:14:13,780 ..and fish live on land. 87 00:14:18,860 --> 00:14:21,660 A dusky-gilled mudskipper... 88 00:14:23,860 --> 00:14:26,300 ..only five centimetres long, 89 00:14:26,300 --> 00:14:29,180 but a master of these swamps. 90 00:14:34,740 --> 00:14:39,300 As long as they can stay wet, they can absorb oxygen from the air, 91 00:14:39,300 --> 00:14:43,300 and they spend most of their life out of water. 92 00:14:46,260 --> 00:14:50,540 Joints in their pectoral fins enable them to walk... 93 00:14:52,860 --> 00:14:55,860 ..and they can leap with a flick of their tail. 94 00:14:59,100 --> 00:15:02,860 This one is seeking a mate with whom to start a family. 95 00:15:05,180 --> 00:15:08,580 But first, he needs to dig a breeding burrow. 96 00:15:25,460 --> 00:15:31,540 Mudskippers will shift up to 300 times their body weight in mud, 97 00:15:31,540 --> 00:15:33,580 one mouthful at a time. 98 00:15:37,740 --> 00:15:39,140 Tiring work! 99 00:15:52,380 --> 00:15:54,980 With the dirty job done, 100 00:15:54,980 --> 00:15:57,060 it's time to find a female. 101 00:16:02,300 --> 00:16:05,740 But the mangroves are full of obstacles. 102 00:16:09,740 --> 00:16:13,220 A special set of grasping belly fins, however, 103 00:16:13,220 --> 00:16:16,620 enable skippers to become climbers. 104 00:16:26,580 --> 00:16:28,860 And when there is a dead end... 105 00:16:34,580 --> 00:16:38,780 ..a mudskipper simply skips across the water's surface, 106 00:16:38,780 --> 00:16:40,420 a metre at a time. 107 00:16:53,260 --> 00:16:54,540 What's this? 108 00:16:57,540 --> 00:16:59,260 An open arena... 109 00:17:02,140 --> 00:17:04,140 ..full of females. 110 00:17:10,420 --> 00:17:11,700 Excellent! 111 00:17:15,900 --> 00:17:20,220 But there are also other males here looking for partners. 112 00:17:27,820 --> 00:17:30,940 To win a female, they must duel. 113 00:17:37,100 --> 00:17:39,300 But no-one is backing down. 114 00:18:03,620 --> 00:18:07,940 Victory and the opponent beats a hasty retreat. 115 00:18:13,940 --> 00:18:15,460 And it looks like this male... 116 00:18:17,140 --> 00:18:18,900 ..has caught someone's eye. 117 00:18:33,500 --> 00:18:36,540 A quick wave should seal the deal. 118 00:18:43,340 --> 00:18:44,580 It's a date. 119 00:18:48,820 --> 00:18:50,940 They head back to his place... 120 00:18:52,820 --> 00:18:55,100 ..ready to start a family of their own. 121 00:19:11,740 --> 00:19:17,020 Mangrove forests are essential for the survival of Asia's mudskippers. 122 00:19:18,380 --> 00:19:23,580 And trap four times more carbon than forests growing on dry land. 123 00:19:27,700 --> 00:19:32,180 Today, Southeast Asia holds a third of what is left of these 124 00:19:32,180 --> 00:19:33,740 precious forests... 125 00:19:36,020 --> 00:19:40,300 ..adding clean, fresh water to the Indonesian Throughflow, 126 00:19:40,300 --> 00:19:41,740 as it travels. 127 00:19:48,060 --> 00:19:50,940 Sweeping away from Indonesia, 128 00:19:50,940 --> 00:19:55,500 the current heads west across the vast Indian Ocean... 129 00:20:01,340 --> 00:20:06,100 ..carrying with it a whole host of drifters. 130 00:20:19,620 --> 00:20:23,620 And some objects provide entertainment 131 00:20:23,620 --> 00:20:26,420 for one of Asia's giants. 132 00:20:35,820 --> 00:20:39,900 A baby sperm whale plays with a mangrove seed, 133 00:20:39,900 --> 00:20:42,580 so practising his coordination. 134 00:20:47,220 --> 00:20:52,460 He produces pulses of high frequency sound from his large head, 135 00:20:52,460 --> 00:20:56,180 sonar that will eventually enable him to locate prey 136 00:20:56,180 --> 00:20:58,020 in the black depths... 137 00:20:59,740 --> 00:21:06,060 ..and zeroing in on a tiny seed is great practice for doing so. 138 00:21:15,580 --> 00:21:17,460 When you're as big as this, 139 00:21:17,460 --> 00:21:20,900 grabbing something the size of a pencil is not easy. 140 00:21:24,500 --> 00:21:28,620 With play over, it's time to get back to the family. 141 00:21:33,900 --> 00:21:36,780 The grown-ups are taking a nap. 142 00:21:39,500 --> 00:21:43,620 It's thought that the reason they sleep upright is to make it 143 00:21:43,620 --> 00:21:45,860 easy to bob up for air. 144 00:21:56,380 --> 00:21:58,860 The calf is keen to join in. 145 00:22:00,420 --> 00:22:02,740 But it's not as easy as it looks. 146 00:22:13,940 --> 00:22:16,900 Staying vertical takes practice. 147 00:22:25,060 --> 00:22:28,300 And when you get the hang of that, 148 00:22:28,300 --> 00:22:31,460 the next challenge is buoyancy. 149 00:22:41,100 --> 00:22:44,940 Holding just the right amount of breath is an art. 150 00:22:54,540 --> 00:22:57,940 Too little and you sink. 151 00:23:06,300 --> 00:23:09,940 The adults tenderly correct his mistakes. 152 00:23:11,500 --> 00:23:13,500 He still has a lot to learn. 153 00:23:17,740 --> 00:23:20,500 In his 70-year lifespan, 154 00:23:20,500 --> 00:23:23,580 he will explore much of the Indian Ocean. 155 00:23:30,980 --> 00:23:35,340 From here, the Indonesian Throughflow continues west... 156 00:23:38,140 --> 00:23:42,500 ..but a very different kind of traffic is moving northwards. 157 00:23:49,260 --> 00:23:50,500 Shipping. 158 00:23:54,620 --> 00:23:58,620 Major international cargo-lanes run from the Indian Ocean 159 00:23:58,620 --> 00:24:03,220 into the Red Sea, which divides Asia from Africa. 160 00:24:07,620 --> 00:24:10,940 At its Northern end is the Suez Canal. 161 00:24:19,180 --> 00:24:23,820 One third of the world's container freight travels along it 162 00:24:23,820 --> 00:24:25,740 and emerges into the Mediterranean... 163 00:24:29,420 --> 00:24:32,380 ..one of the planet's most polluted seas. 164 00:24:42,740 --> 00:24:46,220 Here, on Asia's westernmost coastline, 165 00:24:46,220 --> 00:24:51,220 this Israeli power station discharges water ten degrees hotter 166 00:24:51,220 --> 00:24:53,020 than the surrounding sea. 167 00:25:01,300 --> 00:25:05,460 Astonishingly, this has become a refuge for one of the most 168 00:25:05,460 --> 00:25:07,460 vulnerable of species... 169 00:25:10,340 --> 00:25:12,140 ..dusky sharks. 170 00:25:25,140 --> 00:25:29,060 Mediterranean sharks are the most endangered on Earth. 171 00:25:34,980 --> 00:25:38,260 But up to 100 females come here in winter... 172 00:25:45,900 --> 00:25:50,300 ..and each one of them is pregnant. 173 00:25:52,980 --> 00:25:55,700 It's thought the warmth speeds up 174 00:25:55,700 --> 00:25:58,020 the development of their unborn young. 175 00:26:21,340 --> 00:26:26,180 This power station has created a shark sanctuary by accident. 176 00:26:28,020 --> 00:26:30,060 But elsewhere in Asia, 177 00:26:30,060 --> 00:26:34,140 deliberate steps are being taken to protect marine life. 178 00:26:39,220 --> 00:26:44,060 Over 5,000 miles away on the other side of the continent... 179 00:26:46,820 --> 00:26:52,020 ..life is booming in the unlikeliest of places... 180 00:27:00,820 --> 00:27:05,820 ..the tiny island of Tyuleniy, in far-eastern Russia... 181 00:27:16,940 --> 00:27:19,180 ..a disused hunting settlement. 182 00:27:25,220 --> 00:27:29,300 Here, enormous numbers of fur seals were once killed 183 00:27:29,300 --> 00:27:31,420 annually for their skins. 184 00:27:36,500 --> 00:27:41,100 But hunting restrictions have produced a spectacular recovery. 185 00:27:44,900 --> 00:27:50,980 Over 100,000 Northern fur seals now come here each summer. 186 00:27:50,980 --> 00:27:53,820 It's one of the largest colonies in the world. 187 00:28:05,260 --> 00:28:07,700 The beaches are jam-packed. 188 00:28:11,220 --> 00:28:14,060 BLEATS LOUDLY 189 00:28:18,500 --> 00:28:22,220 Huge, territorial males compete for space. 190 00:28:30,380 --> 00:28:33,100 It's dangerous for the tiny pups, 191 00:28:33,100 --> 00:28:37,300 which weigh just a 50th of the adult bulls. 192 00:28:42,100 --> 00:28:46,220 The aggressive males are only focused on the next challenge. 193 00:28:52,300 --> 00:28:55,980 When fights break out, the pups are ignored. 194 00:29:57,700 --> 00:30:01,180 In the aftermath, many pups lie injured. 195 00:30:20,620 --> 00:30:23,300 Life on the beach is full of danger... 196 00:30:25,780 --> 00:30:27,780 ..but it's no safer in the sea. 197 00:30:41,300 --> 00:30:42,500 Orca. 198 00:30:48,660 --> 00:30:52,940 Fur seals returning from fishing must run the gauntlet. 199 00:31:01,900 --> 00:31:04,220 But these orca are specialists... 200 00:31:08,580 --> 00:31:12,140 ..ramming and tail-slapping to stun their prey. 201 00:31:26,220 --> 00:31:28,380 And when their victim has been disabled... 202 00:31:30,660 --> 00:31:32,180 ..they drown it. 203 00:31:52,860 --> 00:31:56,180 Many pups are left as orphans... 204 00:32:01,900 --> 00:32:05,020 ..but enough will survive to support this now healthy 205 00:32:05,020 --> 00:32:08,220 population of Northern fur seals. 206 00:32:14,780 --> 00:32:18,460 This richness in Asia's shallow seas can also be 207 00:32:18,460 --> 00:32:21,620 found in some of its deepest waters. 208 00:32:34,340 --> 00:32:39,140 Every night, billions of creatures travel up from the abyss. 209 00:32:40,500 --> 00:32:44,340 It's the largest regular movement of life on the planet. 210 00:32:54,740 --> 00:32:59,540 Strange life-forms come up to feed in the surface waters... 211 00:33:04,620 --> 00:33:08,700 ..among them jelly-like salps, which have tiny crustaceans 212 00:33:08,700 --> 00:33:11,460 living inside their bodies. 213 00:33:20,740 --> 00:33:25,780 As dawn arrives, they return to the safety of the deep. 214 00:33:29,940 --> 00:33:34,660 But some creatures, gathering in the Sea of Japan, are about 215 00:33:34,660 --> 00:33:40,220 to embark on a one-way trip out of the depths, never to return. 216 00:33:47,420 --> 00:33:49,140 Firefly squid. 217 00:33:52,780 --> 00:33:55,700 They live for just 12 months. 218 00:34:00,060 --> 00:34:04,420 It's thought that they use their blue bio-luminescent lights 219 00:34:04,420 --> 00:34:05,900 to confuse predators... 220 00:34:07,340 --> 00:34:10,860 ..and their green lights to communicate with one another. 221 00:34:12,660 --> 00:34:15,700 No other deep-sea animal can see green. 222 00:34:15,700 --> 00:34:18,860 It's the squids' own secret code. 223 00:34:22,660 --> 00:34:27,220 Some quarter of a billion females are heading to the surface. 224 00:34:42,340 --> 00:34:47,540 In the shallows, they lay thousands of eggs in strings... 225 00:34:48,780 --> 00:34:51,980 ..the final act of their short lives. 226 00:35:04,380 --> 00:35:08,780 With this done, their bodies are programmed to die. 227 00:35:19,420 --> 00:35:22,940 Here, on the north coast of Japan, 228 00:35:22,940 --> 00:35:26,620 they wash up on the beaches of Toyama Bay. 229 00:35:56,020 --> 00:36:00,180 Their lights fade, as life drifts away. 230 00:36:06,700 --> 00:36:08,900 Their eggs, however... 231 00:36:11,060 --> 00:36:12,980 ..are beginning to hatch. 232 00:36:23,940 --> 00:36:27,700 Sinking into the vast darkness of the deep sea, 233 00:36:27,700 --> 00:36:31,260 they won't return to shallow water for a year, 234 00:36:31,260 --> 00:36:36,100 when it will be their turn to lay eggs and then die. 235 00:36:43,940 --> 00:36:48,900 2,000 miles south, in the western Pacific, lie wide 236 00:36:48,900 --> 00:36:53,380 expanses of shallow seas around the Philippines, 237 00:36:53,380 --> 00:36:55,900 Malaysia and Indonesia... 238 00:36:59,860 --> 00:37:02,860 ..the so-called Coral Triangle. 239 00:37:19,940 --> 00:37:24,500 Here, there are more abundant coral reefs than anywhere else. 240 00:37:25,580 --> 00:37:30,860 It's the richest concentration of marine life on the planet. 241 00:37:37,300 --> 00:37:41,060 Three-quarters of the world's coral species are found here... 242 00:37:44,420 --> 00:37:47,660 ..and over 3,000 species of fish. 243 00:37:49,900 --> 00:37:54,380 It's every bit as diverse as the Amazon rainforest. 244 00:37:59,060 --> 00:38:03,900 Coral reefs truly are the ocean's bustling cities. 245 00:38:06,660 --> 00:38:10,580 Many residents have evolved ingenious ways of solving 246 00:38:10,580 --> 00:38:13,660 the problems of living in such close quarters. 247 00:38:18,500 --> 00:38:22,300 But some appear to be completely defenceless. 248 00:38:32,060 --> 00:38:34,540 Meet the sea bunny. 249 00:38:38,220 --> 00:38:40,220 Just a few centimetres long, 250 00:38:40,220 --> 00:38:43,980 this tiny sea slug has no shell for protection... 251 00:38:48,260 --> 00:38:50,780 ..no eyes to spot danger... 252 00:38:55,180 --> 00:38:59,340 ..and travels at a snail's pace. 253 00:39:03,700 --> 00:39:05,940 It's looking for food. 254 00:39:10,740 --> 00:39:16,900 What appear to be its ears are, in fact, finely-tuned chemical sensors, 255 00:39:16,900 --> 00:39:21,300 that enable it to "smell" its way to its next meal. 256 00:39:34,940 --> 00:39:39,180 But on the reef, predators are everywhere. 257 00:39:43,700 --> 00:39:45,820 When you can't see... 258 00:39:48,660 --> 00:39:50,820 ..it can be hard to avoid trouble. 259 00:39:56,540 --> 00:40:01,220 Alien-like beasts patrol the nooks and crannies of the reef. 260 00:40:26,580 --> 00:40:29,580 This one filters its food from the water... 261 00:40:30,980 --> 00:40:33,380 ..and is no threat to the sea bunny. 262 00:40:38,100 --> 00:40:41,780 But not everything here is quite so harmless. 263 00:40:44,020 --> 00:40:47,740 The Moray eel, powerful and fast... 264 00:40:52,100 --> 00:40:55,340 ..but apparently not keen on slug for dinner. 265 00:41:04,260 --> 00:41:08,860 A scorpionfish, one of the reef's most deadly inhabitants. 266 00:41:11,260 --> 00:41:15,860 Extravagantly camouflaged, it waits for prey to come close... 267 00:41:24,060 --> 00:41:26,500 ..then swallows them whole. 268 00:41:42,620 --> 00:41:46,020 But the sea bunny just walks all over him. 269 00:41:55,780 --> 00:42:00,300 And now, it's headed straight for a deadly-poisonous blue sponge. 270 00:42:03,660 --> 00:42:07,460 Blind and hungry, it's about to take a bite. 271 00:42:16,300 --> 00:42:19,780 It seems that its luck has finally run out. 272 00:42:24,100 --> 00:42:28,780 But, no, this is actually its favourite food. 273 00:42:28,780 --> 00:42:30,740 It's immune to the poison... 274 00:42:32,780 --> 00:42:34,580 ..and by eating the sponge, 275 00:42:34,580 --> 00:42:38,180 the sea bunny has made itself toxic to predators. 276 00:42:41,540 --> 00:42:44,020 No wonder it's untouchable. 277 00:42:47,660 --> 00:42:51,100 As long as it can maintain its blue sponge diet, 278 00:42:51,100 --> 00:42:55,100 the sea bunny will be protected against the dangers of the reef. 279 00:43:02,620 --> 00:43:05,860 With so many complex survival strategies... 280 00:43:07,740 --> 00:43:10,740 ..life for predators on the coral triangle 281 00:43:10,740 --> 00:43:12,860 can require complex tactics. 282 00:43:21,780 --> 00:43:25,660 This snake, a black-banded sea krait, 283 00:43:25,660 --> 00:43:29,100 has venom ten times stronger than a cobra... 284 00:43:34,380 --> 00:43:39,660 ..a forked tongue that enables it to sniff out prey underwater... 285 00:43:42,020 --> 00:43:43,940 ..and a flexible body, 286 00:43:43,940 --> 00:43:47,780 so it can squeeze into crevices on the reef to look for prey. 287 00:43:49,820 --> 00:43:52,060 A formidable killer, it would seem. 288 00:43:58,620 --> 00:44:02,660 Yet, hunting fast prey is not one of its abilities. 289 00:44:06,500 --> 00:44:11,660 It's slow with poor eyesight, hardly the deadliest of assassins. 290 00:44:15,060 --> 00:44:17,740 If only it were fast and agile... 291 00:44:20,900 --> 00:44:22,980 ..like these bluefin trevally. 292 00:44:30,620 --> 00:44:33,860 They rely on sheer speed to catch their prey. 293 00:44:44,740 --> 00:44:46,340 Unlike the snake, 294 00:44:46,340 --> 00:44:49,420 they are too big to get between the arms of the coral. 295 00:44:54,300 --> 00:44:58,020 But these two struggling species have found a solution. 296 00:45:06,380 --> 00:45:08,540 They work as a team. 297 00:45:22,740 --> 00:45:24,540 The trevally leads... 298 00:45:28,700 --> 00:45:31,620 ..indicating places where prey could be hiding... 299 00:45:37,300 --> 00:45:40,620 ..which the snake then investigates. 300 00:45:51,420 --> 00:45:55,900 As they roam the reef, they're joined by more trevally... 301 00:46:00,060 --> 00:46:01,740 ..and more snakes. 302 00:46:11,260 --> 00:46:14,140 Soon, they are an army. 303 00:46:28,460 --> 00:46:31,100 The trevally find a target. 304 00:46:36,860 --> 00:46:38,380 The snakes head in... 305 00:46:41,340 --> 00:46:44,580 ..and the trevally cover the escape routes. 306 00:46:52,180 --> 00:46:54,220 There's nowhere left to hide. 307 00:47:02,820 --> 00:47:05,700 The trevally catch the fish that are flushed out... 308 00:47:12,900 --> 00:47:16,300 ..and the snake eats anything left inside. 309 00:47:30,260 --> 00:47:33,260 Each species benefits from the partnership. 310 00:47:38,180 --> 00:47:41,180 The hunts are so successful that they attract 311 00:47:41,180 --> 00:47:43,500 hundreds of trevally and snakes. 312 00:48:04,860 --> 00:48:07,900 This behaviour is extremely rare, 313 00:48:07,900 --> 00:48:11,580 and has only been seen in Asia's coral triangle. 314 00:48:13,500 --> 00:48:17,140 Innovation and teamwork are critical to success 315 00:48:17,140 --> 00:48:19,900 in these competitive waters. 316 00:48:31,740 --> 00:48:36,500 These relationships and strategies developed over millennia, 317 00:48:36,500 --> 00:48:40,340 are a consequence of the extraordinary richness of 318 00:48:40,340 --> 00:48:41,860 Asia's seas. 319 00:48:45,620 --> 00:48:49,460 And whilst our influence is now not far away, 320 00:48:49,460 --> 00:48:53,700 Asia's oceans still remain a world of wonder, 321 00:48:53,700 --> 00:48:57,900 offering spectacles not found anywhere else on Earth. 322 00:49:15,180 --> 00:49:20,340 The Asia team explored many of the continent's 21 seas. 323 00:49:22,540 --> 00:49:25,460 They spent thousands of hours underwater, 324 00:49:25,460 --> 00:49:28,500 filming the spectacular diversity of life. 325 00:49:40,380 --> 00:49:43,580 But their biggest challenge was getting up close with 326 00:49:43,580 --> 00:49:46,100 some of the most powerful currents on earth. 327 00:49:50,220 --> 00:49:55,180 The Indonesian Throughflow carries ten times more water than all 328 00:49:55,180 --> 00:49:57,220 the world's rivers combined. 329 00:50:06,140 --> 00:50:10,740 The tide has to make its way from the Pacific to the Indian, 330 00:50:10,740 --> 00:50:12,660 and that's a huge amount of water. 331 00:50:12,660 --> 00:50:13,780 And as it does that, 332 00:50:13,780 --> 00:50:16,140 it gets squeezed through these islands, which 333 00:50:16,140 --> 00:50:20,260 creates intense currents, but also brings an incredible amount of life. 334 00:50:23,220 --> 00:50:26,940 The team want to capture this immense power up close... 335 00:50:28,340 --> 00:50:31,060 ..but the fast currents are making filming difficult. 336 00:50:35,740 --> 00:50:39,060 For their first attempt, they use a pole-mounted camera. 337 00:50:45,460 --> 00:50:48,940 But getting the boat into position is almost impossible. 338 00:50:52,300 --> 00:50:54,460 We're fighting a losing battle. Yeah. We'll drop it. 339 00:50:54,460 --> 00:50:56,140 Let's go back to the main boat. 340 00:50:57,380 --> 00:51:00,620 David thinks he has a solution, but it's radical. 341 00:51:02,300 --> 00:51:05,300 He's going to get in the water himself, 342 00:51:05,300 --> 00:51:09,860 using a floating camera rig to film inside the vortex. 343 00:51:11,020 --> 00:51:14,780 We'll see the swirling water, literally the opening of the 344 00:51:14,780 --> 00:51:18,860 funnel of the whirlpool, that's what I want, it's like the epic shot. 345 00:51:20,300 --> 00:51:22,500 If the shot works, it's going to be amazing. 346 00:51:22,500 --> 00:51:25,300 It's going to really tell the story of the currents nicely. 347 00:51:28,420 --> 00:51:31,980 So, I think what we have to do is put David up current, initially, 348 00:51:31,980 --> 00:51:33,780 but close-ish in to the island, 349 00:51:33,780 --> 00:51:35,620 to get those swirls, as you come past. 350 00:51:35,620 --> 00:51:37,540 What's the normal advice for divers here? 351 00:51:37,540 --> 00:51:40,780 Normally, we'll actually jump right next to the island where there's no current. 352 00:51:40,780 --> 00:51:43,580 They stay out of the current entirely... Yes. 353 00:51:43,580 --> 00:51:46,540 ..which is the opposite to what you're going to be doing! Yes. OK, yeah. 354 00:51:46,540 --> 00:51:49,820 This challenge is unlike anything David has faced 355 00:51:49,820 --> 00:51:51,740 in 30 years of film-making. 356 00:51:53,340 --> 00:51:58,740 I'm going to add two life jackets to the camera rig, and you know 357 00:51:58,740 --> 00:52:01,740 if I start to get sucked down I'm going to just hang on to that. 358 00:52:07,060 --> 00:52:10,220 The key to staying safe will be buoyancy. 359 00:52:10,220 --> 00:52:12,060 Yeah, I don't know if I can get this third one on. 360 00:52:12,060 --> 00:52:15,900 Three life jackets should resist the pull of the whirlpools. 361 00:52:15,900 --> 00:52:17,020 It's not that bad. 362 00:52:18,900 --> 00:52:21,100 What do you think? Money? Yeah. 363 00:52:23,500 --> 00:52:26,540 The team decide to dive on the rising tide 364 00:52:26,540 --> 00:52:28,180 when the currents are weaker. 365 00:52:32,940 --> 00:52:34,820 I think I'm plenty floaty! 366 00:52:37,300 --> 00:52:40,460 David's home-made protection is holding up well. 367 00:52:48,260 --> 00:52:52,180 The current is running fast, but the whirlpools aren't forming. 368 00:52:53,980 --> 00:52:55,820 David, nothing? Nothing. 369 00:52:55,820 --> 00:52:59,220 Nothing at all? Like, I... I feel the current, and I, like, I don't 370 00:52:59,220 --> 00:53:04,660 see any, like, whirlpools, bubbles, hardly anything in the water. 371 00:53:04,660 --> 00:53:06,700 Do you want picking up? 372 00:53:06,700 --> 00:53:08,100 Yeah. 373 00:53:10,540 --> 00:53:13,420 It seems that if David is to get his shots... 374 00:53:15,860 --> 00:53:19,580 ..he will have to brave the much faster falling tide. 375 00:53:29,460 --> 00:53:32,900 Preparation will be key to success. 376 00:53:42,540 --> 00:53:44,860 Whirlpools only last a few seconds, 377 00:53:44,860 --> 00:53:49,820 so to get in the right position, the team needs eyes in the sky. 378 00:53:53,340 --> 00:53:54,940 Drone's in the air. 379 00:53:54,940 --> 00:53:57,180 OK, copy, copy. What do you guys see? 380 00:53:57,180 --> 00:54:00,220 The current looks strong on that eastern edge of the island. 381 00:54:00,220 --> 00:54:04,020 If you can spot good places where the whirlpools are cropping up... 382 00:54:06,740 --> 00:54:09,940 Mark, Mark, the swirl's forming on the edge you're at. 383 00:54:09,940 --> 00:54:11,580 Right, thanks, mate. 384 00:54:11,580 --> 00:54:14,740 Look, we've got some, definitely some forming here. 385 00:54:17,020 --> 00:54:20,500 David must get to the whirlpools before they dissipate. 386 00:54:22,980 --> 00:54:26,500 Is this a good spot? Yeah, I call it right here. 387 00:54:26,500 --> 00:54:27,740 OK, clear to go. 388 00:54:36,180 --> 00:54:38,500 You're going to get sucked in pretty quickly. 389 00:54:39,980 --> 00:54:41,340 Behind you, David. 390 00:54:45,260 --> 00:54:48,660 Mark is ready with a throw rope, in case of trouble. 391 00:54:55,700 --> 00:54:56,980 You OK? 392 00:54:59,620 --> 00:55:01,060 Do you want the rope? 393 00:55:02,980 --> 00:55:04,180 He's OK. 394 00:55:04,180 --> 00:55:05,620 He wants to carry on. 395 00:55:07,260 --> 00:55:09,580 David's commitment is paying off. 396 00:55:12,340 --> 00:55:14,300 He's starting to get the shots. 397 00:55:28,060 --> 00:55:30,700 But the whirlpools are growing stronger. 398 00:55:41,220 --> 00:55:43,740 That is putting him right in the whirlpool zone. 399 00:55:49,460 --> 00:55:51,100 He's getting sucked in. 400 00:55:58,620 --> 00:56:00,860 All he can do now is hang on. 401 00:56:03,980 --> 00:56:05,820 OK, can we get closer to David? 402 00:56:09,580 --> 00:56:11,460 Whoa! 403 00:56:11,460 --> 00:56:14,580 At last, the whirlpool spits him out. 404 00:56:19,020 --> 00:56:20,500 David, you OK? 405 00:56:20,500 --> 00:56:21,940 Yeah. 406 00:56:23,660 --> 00:56:27,660 It's hairy. It's not doing anything for my nerves, let alone David's. 407 00:56:28,940 --> 00:56:32,540 It's time to get back into the safety of the boat. 408 00:56:32,540 --> 00:56:35,060 OK? Yeah. 409 00:56:35,060 --> 00:56:38,380 It had me. Like, I could feel myself going bloob, bloob, bloob, blub, blub. 410 00:56:38,380 --> 00:56:42,140 Really? Like that, but I had, I had enough, I kind of kept my hands on the camera. 411 00:56:42,140 --> 00:56:46,460 Yeah. I didn't even see it coming, suddenly I was like... Yeah, yeah, yeah. 412 00:56:46,460 --> 00:56:48,420 A good whirlpool, huh? 413 00:56:48,420 --> 00:56:52,380 David's plan has succeeded. 414 00:56:52,380 --> 00:56:56,420 Yeah! He's faced Asia's ripping whirlpools, 415 00:56:56,420 --> 00:57:00,060 and captured their fierce beauty, as never before. 416 00:57:07,020 --> 00:57:11,460 Next time, we journey to Asia's remarkable mountains... 417 00:57:14,860 --> 00:57:17,420 ..a world full of surprises... 418 00:57:20,820 --> 00:57:25,300 ..and home to some of the most captivating creatures on the planet.