1 00:00:00,000 --> 00:00:03,080 DAVID ATTENBOROUGH: Beneath the Yucatan Peninsula 2 00:00:03,200 --> 00:00:04,640 of Mexico... 3 00:00:06,240 --> 00:00:09,080 ...lies another world. 4 00:00:12,240 --> 00:00:15,320 A labyrinth of caves... 5 00:00:17,880 --> 00:00:21,480 ...carved by freshwater. 6 00:00:27,880 --> 00:00:31,280 An essential for life on Earth. 7 00:00:57,960 --> 00:01:00,400 Freshwater shapes the land 8 00:01:00,520 --> 00:01:03,480 and the creatures that live in it... 9 00:01:05,600 --> 00:01:08,360 ...in the most surprising ways. 10 00:01:17,520 --> 00:01:19,680 (BIRDSONG) 11 00:01:24,520 --> 00:01:27,200 The rainforest of Costa Rica. 12 00:01:28,960 --> 00:01:33,360 As you might expect, it rains most days. 13 00:01:33,480 --> 00:01:35,960 (THUNDER RUMBLES) 14 00:01:36,080 --> 00:01:38,320 But it's only during the wet season 15 00:01:38,440 --> 00:01:41,760 that the rains become torrential. 16 00:01:50,240 --> 00:01:51,320 And with them... 17 00:01:52,920 --> 00:01:55,760 ...comes a most remarkable creature. 18 00:02:11,400 --> 00:02:14,120 Gliding tree frogs. 19 00:02:20,200 --> 00:02:22,960 Thousands drop in... 20 00:02:25,720 --> 00:02:29,960 ...together, at this newly formed pond. 21 00:02:37,120 --> 00:02:40,080 They all have an urgent need. 22 00:02:46,320 --> 00:02:47,360 To breed. 23 00:03:01,200 --> 00:03:04,560 This female needs to find a leaf 24 00:03:04,680 --> 00:03:06,400 and lay her eggs. 25 00:03:07,640 --> 00:03:10,120 (CHORUS OF CROAKING) 26 00:03:11,680 --> 00:03:15,680 The breeding frenzy will only last one day... 27 00:03:16,760 --> 00:03:19,800 ...so she needs to get a move on. 28 00:03:25,440 --> 00:03:28,280 There are lots of eager males. 29 00:03:34,080 --> 00:03:36,320 Nine for every female. 30 00:03:40,720 --> 00:03:44,840 And all are ready to spring into action. 31 00:03:50,640 --> 00:03:55,080 So for her, getting a partner is no problem. 32 00:04:04,320 --> 00:04:07,560 But the other males are desperate. 33 00:04:28,000 --> 00:04:32,200 For this female, mating is rather chaotic. 34 00:04:43,760 --> 00:04:46,400 Things are getting out of hand. 35 00:04:55,400 --> 00:04:58,080 There is one way to deal with this. 36 00:05:04,520 --> 00:05:06,720 A few well-placed kicks... 37 00:05:09,720 --> 00:05:11,520 ...usually does the job. 38 00:05:24,360 --> 00:05:25,840 Problem solved. 39 00:05:30,240 --> 00:05:34,840 She and her partner can now finally mate... 40 00:05:34,960 --> 00:05:37,880 ...in relative peace. 41 00:06:01,280 --> 00:06:03,200 (BOING) 42 00:06:08,280 --> 00:06:11,040 The eggs are positioned perfectly... 43 00:06:12,280 --> 00:06:14,880 ...directly overhanging the pond. 44 00:06:21,240 --> 00:06:23,320 (SQUELCH) 45 00:06:31,320 --> 00:06:33,040 (SPLASH) 46 00:06:33,160 --> 00:06:37,720 This is the ideal nursery for tadpoles. 47 00:06:41,560 --> 00:06:42,480 For now, 48 00:06:42,600 --> 00:06:44,360 her work here is done. 49 00:06:45,400 --> 00:06:49,440 She'll be back next year when the heavy rains return. 50 00:06:53,720 --> 00:06:56,320 As quickly as freshwater appears... 51 00:06:59,240 --> 00:07:01,200 ...it can vanish. 52 00:07:07,120 --> 00:07:10,720 (CRACKING) 53 00:07:13,360 --> 00:07:15,360 Southeast Sri Lanka. 54 00:07:15,480 --> 00:07:18,400 (FLIES BUZZ) 55 00:07:18,520 --> 00:07:21,080 It's the middle of the dry season. 56 00:07:26,800 --> 00:07:29,000 (WIND WHOOSHES) 57 00:07:37,840 --> 00:07:40,880 This is the only remaining water hole 58 00:07:41,000 --> 00:07:42,560 for miles around. 59 00:07:50,680 --> 00:07:52,240 (BIRD CALLS) 60 00:08:37,240 --> 00:08:38,520 (HIGH-PITCHED HONK) 61 00:08:41,440 --> 00:08:43,880 Mugger crocodiles. 62 00:08:44,000 --> 00:08:47,160 Giants. Five metres long. 63 00:08:50,720 --> 00:08:53,320 Dozens are hiding 64 00:08:53,440 --> 00:08:55,400 beneath the surface. 65 00:09:03,960 --> 00:09:05,320 And others... 66 00:09:06,880 --> 00:09:08,320 ...are on their way. 67 00:09:26,480 --> 00:09:29,840 This male has been travelling for hours. 68 00:09:36,640 --> 00:09:38,920 The water hole is the only place 69 00:09:39,040 --> 00:09:41,480 Where he has a chance to catch a deer. 70 00:09:53,600 --> 00:09:56,320 A single adult would be enough to feed him 71 00:09:56,440 --> 00:09:58,720 for the entire dry season. 72 00:10:09,800 --> 00:10:12,320 But hunting prey that knows you're here... 73 00:10:13,800 --> 00:10:16,920 ...requires something truly remarkable. 74 00:10:35,120 --> 00:10:36,440 He creates... 75 00:10:37,640 --> 00:10:38,920 ...a trap. 76 00:10:49,400 --> 00:10:53,040 He digs down into the mud. 77 00:11:05,760 --> 00:11:09,280 Deep enough to hide beneath the vegetation. 78 00:11:27,080 --> 00:11:29,320 Perfect camouflage. 79 00:11:40,760 --> 00:11:44,640 He has built his trap right on the water's edge. 80 00:11:46,600 --> 00:11:48,400 So it's the first place 81 00:11:48,520 --> 00:11:51,640 that thirsty deer will come to drink. 82 00:12:14,520 --> 00:12:16,080 (RAPID SQUAWKING) 83 00:12:22,000 --> 00:12:23,680 (FLIES BUZZ) 84 00:12:26,000 --> 00:12:28,840 (SNIFFS) 85 00:13:46,720 --> 00:13:49,840 These crocodiles have learned to exploit 86 00:13:49,960 --> 00:13:53,160 the deer's desperate need for freshwater. 87 00:14:02,400 --> 00:14:04,240 (TRICKLING) 88 00:14:06,040 --> 00:14:07,480 Freshwater transforms 89 00:14:07,600 --> 00:14:10,160 not only the lives of animals... 90 00:14:11,960 --> 00:14:14,360 ...but entire landscapes. 91 00:14:26,960 --> 00:14:30,640 Every year, over a trillion litres of water 92 00:14:30,760 --> 00:14:33,640 flow into the Kalahari Desert. 93 00:14:42,040 --> 00:14:44,320 It has travelled a thousand miles 94 00:14:44,440 --> 00:14:46,760 from Where it fell as rain. 95 00:14:52,200 --> 00:14:53,800 And on arrival... 96 00:14:55,800 --> 00:14:58,440 ...it turns the Kalahari 97 00:14:58,560 --> 00:15:01,920 into a vast oasis. 98 00:15:05,400 --> 00:15:08,320 (SQUAWKING) 99 00:15:10,880 --> 00:15:12,920 The Okavango Delta. 100 00:15:35,280 --> 00:15:38,960 These waters attract millions of animals. 101 00:15:47,800 --> 00:15:49,080 And for some, 102 00:15:49,200 --> 00:15:53,840 now is the perfect time to raise a family. 103 00:15:56,280 --> 00:15:57,520 (GENTLE SPLASH) 104 00:16:07,000 --> 00:16:08,680 A lily-trotter. 105 00:16:10,720 --> 00:16:12,000 (CRACKING) 106 00:16:15,200 --> 00:16:16,840 And he is a father... 107 00:16:16,960 --> 00:16:18,880 - (CHIRPS) - ...on duty. 108 00:16:31,360 --> 00:16:34,000 (ALARMED CHIRPING) 109 00:16:38,560 --> 00:16:40,520 He has not just one... 110 00:16:42,920 --> 00:16:46,080 ...but four newly hatched chicks. 111 00:17:00,120 --> 00:17:01,720 (SQUEAKING) 112 00:17:01,840 --> 00:17:06,040 They won't be able to fly for another six weeks. 113 00:17:09,160 --> 00:17:13,680 80, until then, he alone is their protector. 114 00:17:20,800 --> 00:17:24,520 Walking on water is not straightforward. 115 00:17:24,640 --> 00:17:25,680 (CHIRPS) 116 00:17:27,400 --> 00:17:31,880 So he must show them how to be a lily-trotter. 117 00:17:53,200 --> 00:17:57,080 The floodwaters make the perfect training ground. 118 00:18:13,600 --> 00:18:15,480 And in two weeks... 119 00:18:17,360 --> 00:18:20,400 ...his chicks not only double in size... 120 00:18:22,040 --> 00:18:24,200 ...they grow in confidence. 121 00:18:24,320 --> 00:18:26,520 (SQUEAKING) 122 00:18:35,560 --> 00:18:39,520 But this is a dangerous place to stray. 123 00:18:47,280 --> 00:18:48,920 (WARBLES) 124 00:18:49,040 --> 00:18:51,040 He sounds the alarm, 125 00:18:51,160 --> 00:18:54,400 and his chicks instantly freeze. 126 00:18:56,640 --> 00:18:59,000 They can't yet fly to safety. 127 00:19:02,240 --> 00:19:05,320 But there is one thing he can do to protect them. 128 00:19:05,440 --> 00:19:08,000 (BURST OF RAPID CHIRPING) 129 00:19:08,120 --> 00:19:09,840 And it's risky. 130 00:19:09,960 --> 00:19:12,680 (SHRILL CHIRPING) 131 00:19:12,800 --> 00:19:15,840 Get close enough to distract... 132 00:19:17,200 --> 00:19:20,040 ...and hopefully divert the crocodile. 133 00:19:23,320 --> 00:19:26,360 (CHIRPING) 134 00:19:31,520 --> 00:19:34,520 (BURST OF RAPID CHIRPING) 135 00:19:39,160 --> 00:19:41,280 (CHIRPS) 136 00:19:50,440 --> 00:19:52,920 Mission accomplished. 137 00:20:05,160 --> 00:20:06,880 (LONG CHIRP) 138 00:20:07,000 --> 00:20:10,200 He signals the all-clear. 139 00:20:10,320 --> 00:20:11,840 (SQUEAKS) 140 00:20:14,120 --> 00:20:17,040 (CHICKS SQUEAK) 141 00:20:22,840 --> 00:20:25,200 But one chick is missing. 142 00:20:27,960 --> 00:20:31,640 (SHRILL CHIRPING) 143 00:20:40,840 --> 00:20:42,320 (CHIRPING) 144 00:20:45,400 --> 00:20:47,520 (CHIRPING) 145 00:20:48,960 --> 00:20:53,360 His calls go unanswered. 146 00:20:56,160 --> 00:20:57,840 (CHIRPS) 147 00:21:09,320 --> 00:21:11,440 (CHIRPING) 148 00:21:35,840 --> 00:21:37,360 (SOFT CHIRPING) 149 00:21:46,960 --> 00:21:50,120 A little bedraggled, but alive and well. 150 00:21:50,240 --> 00:21:52,440 (LONG CHIRP) 151 00:21:56,560 --> 00:22:00,000 His chick just hadn't heard his call. 152 00:22:01,600 --> 00:22:03,480 And when danger threatens, 153 00:22:03,600 --> 00:22:06,640 it's always better to be safe than sorry. 154 00:22:35,360 --> 00:22:38,120 He's brought his chicks, all four of them, 155 00:22:38,240 --> 00:22:41,120 to the verge of independence. 156 00:22:55,000 --> 00:22:58,080 Whilst lily-trotters are well adapted to life 157 00:22:58,200 --> 00:22:59,760 in this flooded world... 158 00:22:59,880 --> 00:23:02,720 (PANTING) 159 00:23:02,840 --> 00:23:06,840 ...these residents of the delta are not. 160 00:23:18,480 --> 00:23:20,880 African painted dogs. 161 00:23:24,120 --> 00:23:28,560 Normally, they are remarkably successful hunters, 162 00:23:28,680 --> 00:23:32,920 but this pack of five hasn't eaten in days. 163 00:23:33,040 --> 00:23:35,960 (PANTING) 164 00:23:36,080 --> 00:23:38,840 (DISTANT BELLOWS) 165 00:23:38,960 --> 00:23:42,000 Finding prey isn't the problem. 166 00:23:49,120 --> 00:23:52,960 This herd of lechwe is only a few hundred metres away. 167 00:23:58,240 --> 00:24:01,840 But between them is deep water. 168 00:24:16,840 --> 00:24:19,680 (NERVOUS YIPPING) 169 00:24:22,520 --> 00:24:25,040 (DEEP BELLOWING) 170 00:24:25,160 --> 00:24:28,720 (HIPPO HONKS AND BELLOWS) 171 00:24:37,480 --> 00:24:40,120 It's not safe to cross here. 172 00:25:07,200 --> 00:25:09,280 (HIGH-PITCHED SQUEAL) 173 00:26:04,440 --> 00:26:05,400 (GRUNTS) 174 00:26:26,120 --> 00:26:30,840 On dry land, the dogs can run at over 40 miles an hour. 175 00:26:37,440 --> 00:26:38,840 But when threatened, 176 00:26:38,960 --> 00:26:42,120 lechwe always seek the safety of water. 177 00:26:48,360 --> 00:26:51,200 With their splayed hooves and long hind legs, 178 00:26:51,320 --> 00:26:53,680 they can power their way through the water. 179 00:26:56,040 --> 00:26:58,040 The dogs can't. 180 00:27:21,880 --> 00:27:25,960 The pack won't be able to outswim the lechwe. 181 00:27:29,040 --> 00:27:31,960 But they do have a strategy. 182 00:27:52,640 --> 00:27:54,720 The dogs drive the lechwe to Where 183 00:27:54,840 --> 00:27:56,840 they have the advantage. 184 00:28:02,440 --> 00:28:05,120 Back towards dry land. 185 00:28:09,120 --> 00:28:12,920 Now the pack can regain lost ground. 186 00:28:57,120 --> 00:29:00,200 (LECHWE WHIMPERS) 187 00:29:00,320 --> 00:29:02,360 Success today, 188 00:29:02,480 --> 00:29:05,840 but tomorrow the pack will need to hunt again. 189 00:29:09,480 --> 00:29:11,040 In the Okavango, 190 00:29:11,160 --> 00:29:15,280 animals must always adapt to the coming and going 191 00:29:15,400 --> 00:29:16,680 of freshwater. 192 00:29:21,440 --> 00:29:24,120 But there are a few rare places, 193 00:29:24,240 --> 00:29:26,120 as here in Lake Malawi, 194 00:29:26,240 --> 00:29:30,400 Where freshwater has Iain for millions of years. 195 00:29:33,240 --> 00:29:36,840 And that has enabled life to evolve 196 00:29:36,960 --> 00:29:40,480 into a dazzling diversity of species. 197 00:29:47,280 --> 00:29:50,560 There are over a thousand different kinds of fish here. 198 00:29:51,960 --> 00:29:54,640 More than any other lake on Earth. 199 00:30:05,760 --> 00:30:10,000 Competition in these waters is intense. 200 00:30:32,600 --> 00:30:37,560 Meet Nimbochromis Iivingstonii. 201 00:30:40,560 --> 00:30:42,360 A master of deception 202 00:30:42,480 --> 00:30:46,520 that tricks other fish into thinking it's dead. 203 00:30:50,280 --> 00:30:55,240 Its mottled colouration mimics decaying flesh. 204 00:31:01,240 --> 00:31:03,480 But to appear dead... 205 00:31:06,600 --> 00:31:11,600 ...one must at least act dead. 206 00:31:15,280 --> 00:31:18,520 This juvenile is fooling no-one. 207 00:31:23,760 --> 00:31:27,920 Perhaps faking his death will be more believable. 208 00:31:53,920 --> 00:31:54,920 Blown it. 209 00:32:05,920 --> 00:32:08,720 A more subtle performance will be needed. 210 00:32:22,120 --> 00:32:24,520 This is more convincing. 211 00:32:37,080 --> 00:32:40,440 But his aim must be better than that. 212 00:32:47,440 --> 00:32:48,840 Nearly. 213 00:32:56,440 --> 00:32:59,240 It seems he's overstayed his welcome. 214 00:33:32,600 --> 00:33:34,440 In a final effort, 215 00:33:34,560 --> 00:33:37,960 he appears to even hold his breath. 216 00:33:58,720 --> 00:34:01,240 Success at last. 217 00:34:21,280 --> 00:34:25,240 All it took was a million years of evolution... 218 00:34:34,000 --> 00:34:38,480 ...and the unique stability of this ancient lake. 219 00:34:47,600 --> 00:34:51,440 Off the western coast of equatorial Africa 220 00:34:51,560 --> 00:34:55,280 lies the volcanic island of Bioko. 221 00:34:57,840 --> 00:35:00,640 (THUNDER RUMBLES) 222 00:35:06,000 --> 00:35:09,920 Freshwater here has a turbulent nature. 223 00:35:46,040 --> 00:35:49,320 Few venture into such waters, 224 00:35:49,440 --> 00:35:51,360 but for those that do, 225 00:35:51,480 --> 00:35:54,000 there can be great rewards. 226 00:35:56,720 --> 00:35:59,760 After months feeding and growing out at sea, 227 00:35:59,880 --> 00:36:02,760 these gobies are ready to breed. 228 00:36:06,320 --> 00:36:09,280 And the safest place to lay their eggs 229 00:36:09,400 --> 00:36:13,120 is somewhere that ocean predators can't reach. 230 00:36:16,000 --> 00:36:18,080 The top of this waterfall. 231 00:36:24,040 --> 00:36:27,480 Surely an impossible journey for a fish. 232 00:36:31,480 --> 00:36:33,480 But over the coming days, 233 00:36:33,600 --> 00:36:36,800 the gobies transform themselves. 234 00:36:40,200 --> 00:36:41,680 They change colour. 235 00:36:46,960 --> 00:36:52,680 Their mouth rotates and acts like a kind of suction cup. 236 00:36:54,280 --> 00:36:56,600 Which they will certainly need. 237 00:37:02,160 --> 00:37:04,160 Because the only way... 238 00:37:05,240 --> 00:37:07,280 ...is up. 239 00:37:27,800 --> 00:37:30,680 It is 30 metres to the top. 240 00:37:37,640 --> 00:37:40,720 They are only an inch long. 241 00:37:43,680 --> 00:37:45,400 This is the equivalent 242 00:37:45,520 --> 00:37:48,160 of a human being scaling a waterfall 243 00:37:48,280 --> 00:37:50,000 over a mile high. 244 00:37:59,880 --> 00:38:02,400 Millions attempt the climb... 245 00:38:03,960 --> 00:38:06,840 ...but less than 1 % will make it. 246 00:38:17,360 --> 00:38:20,480 This goby has been climbing for days. 247 00:38:29,160 --> 00:38:30,640 Made it! 248 00:38:34,880 --> 00:38:39,360 Those that reach the top can now prepare to breed. 249 00:38:42,680 --> 00:38:44,320 And when the time comes, 250 00:38:44,440 --> 00:38:48,080 their young will be washed back out to sea. 251 00:39:09,040 --> 00:39:11,760 The extraordinary power of flowing water 252 00:39:11,880 --> 00:39:15,120 makes it our planet's greatest architect. 253 00:39:35,680 --> 00:39:39,960 This may look like the surface of an alien planet. 254 00:39:53,280 --> 00:39:58,280 But these strange patterns are channels of freshwater... 255 00:40:01,240 --> 00:40:03,280 ...rowing towards the sea. 256 00:40:17,920 --> 00:40:20,600 For 3.8 billion years, 257 00:40:20,720 --> 00:40:23,240 ever since the first rains fell... 258 00:40:24,960 --> 00:40:28,200 ...freshwater has been making this journey. 259 00:40:44,240 --> 00:40:48,840 But today, two thirds of our world's great rivers 260 00:40:48,960 --> 00:40:51,120 no longer reach the sea. 261 00:41:04,080 --> 00:41:07,000 (DEEP CREAKING) 262 00:41:23,840 --> 00:41:27,840 There is a finite amount of freshwater on Earth. 263 00:41:31,800 --> 00:41:35,240 (ECHOING CREAKS) 264 00:41:40,320 --> 00:41:44,000 So humans have devised extraordinary means 265 00:41:44,120 --> 00:41:47,400 to ensure that it is always available 266 00:41:47,520 --> 00:41:49,640 to meet our every demand. 267 00:41:51,440 --> 00:41:53,800 (GEARS GRINDING) 268 00:42:00,000 --> 00:42:03,880 We now control freshwater 269 00:42:04,000 --> 00:42:07,400 on a colossal scale. 270 00:42:11,800 --> 00:42:14,600 The largest irrigation system on Earth 271 00:42:14,720 --> 00:42:17,960 has been built here, in Pakistan. 272 00:42:19,320 --> 00:42:21,240 (HONKING) 273 00:42:27,240 --> 00:42:30,760 A vast network of dams and canals... 274 00:42:33,720 --> 00:42:37,920 ...that diverts and drains the great Indus River. 275 00:42:44,440 --> 00:42:48,880 It's used to irrigate an area the size of England. 276 00:42:53,640 --> 00:42:57,080 This man-made freshwater world 277 00:42:57,200 --> 00:42:59,320 provides water and a livelihood 278 00:42:59,440 --> 00:43:01,600 for millions of people. 279 00:43:01,720 --> 00:43:03,360 (LAUGHING) 280 00:43:09,680 --> 00:43:13,280 But at a cost to the natural world. 281 00:43:26,280 --> 00:43:29,280 A rare creature has become stranded 282 00:43:29,400 --> 00:43:31,680 in this irrigation canal. 283 00:43:35,400 --> 00:43:38,280 And the water will soon be gone, 284 00:43:38,400 --> 00:43:42,320 used to supply the surrounding land. 285 00:43:48,040 --> 00:43:53,000 Endangered, they number fewer than 2,000 individuals. 286 00:43:58,680 --> 00:44:01,040 An Indus river dolphin. 287 00:44:14,800 --> 00:44:19,200 This female dolphin is 150 miles 288 00:44:19,320 --> 00:44:20,840 from the main river. 289 00:44:24,640 --> 00:44:26,960 She can't return on her own. 290 00:44:27,080 --> 00:44:29,120 So the only option 291 00:44:29,240 --> 00:44:32,080 is for this rescue team to take her. 292 00:44:36,760 --> 00:44:39,480 (EXCITED CHATTER) 293 00:44:56,520 --> 00:45:00,520 Out of water, she cannot survive for long. 294 00:45:06,840 --> 00:45:10,120 The journey back to the river will take hours. 295 00:45:19,960 --> 00:45:24,800 Her life now depends on these people. 296 00:46:42,600 --> 00:46:46,400 (EXCITED CHATTER) 297 00:47:15,080 --> 00:47:19,200 Nearly 30 dolphins had to be rescued 298 00:47:19,320 --> 00:47:22,080 in one month alone. 299 00:47:51,680 --> 00:47:56,080 Freshwater is not only a resource for humans... 300 00:48:02,280 --> 00:48:06,720 ...it is the home for countless species 301 00:48:06,840 --> 00:48:11,840 that simply cannot survive without it. 302 00:48:30,920 --> 00:48:34,360 Freshwater is the lifeblood... 303 00:48:34,480 --> 00:48:36,920 ...of Planet Earth. 304 00:48:58,080 --> 00:49:00,080 DAVID: To film the story 305 00:49:00,200 --> 00:49:03,080 of the most endangered freshwater dolphin, 306 00:49:03,200 --> 00:49:06,240 the Planet Earth team joined the world's leading expert, 307 00:49:06,360 --> 00:49:08,120 Uzma Khan. 308 00:49:08,240 --> 00:49:10,040 The first time I saw an Indus dolphin, 309 00:49:10,160 --> 00:49:11,880 I was just amazed. 310 00:49:12,000 --> 00:49:14,200 It's a beautiful creature, you know? 311 00:49:14,320 --> 00:49:16,880 It's like love at first sight. It's so unique. 312 00:49:18,520 --> 00:49:22,320 Uzma has been studying the last remaining population 313 00:49:22,440 --> 00:49:24,640 for over 20 years. 314 00:49:26,160 --> 00:49:28,000 There's a dolphin that surfaced 315 00:49:28,120 --> 00:49:29,520 just right there. 316 00:49:29,640 --> 00:49:34,120 Indus river dolphin can only live in freshwater. 317 00:49:34,240 --> 00:49:37,160 It is only found in Pakistan and nowhere else, 318 00:49:37,280 --> 00:49:40,480 and we only have about 2,000 of them left 319 00:49:40,600 --> 00:49:42,160 in the Indus River. 320 00:49:42,280 --> 00:49:45,880 So, you know, each individual is special. 321 00:49:48,000 --> 00:49:50,320 Following the dolphins in the murky water 322 00:49:50,440 --> 00:49:52,960 is extremely challenging. 323 00:49:54,040 --> 00:49:56,880 They only surface for a split second, 324 00:49:57,000 --> 00:50:00,840 and that makes protecting them difficult, too. 325 00:50:00,960 --> 00:50:04,040 Their greatest threat is becoming trapped 326 00:50:04,160 --> 00:50:06,360 in the irrigation canals. 327 00:50:07,840 --> 00:50:10,200 But Uzma may have a solution, 328 00:50:10,320 --> 00:50:14,240 and teams up with a rescue unit 329 00:50:14,360 --> 00:50:18,360 to attempt something never done before. 330 00:50:20,160 --> 00:50:23,200 This is the first time we'll be putting satellite tags 331 00:50:23,320 --> 00:50:25,680 on river dolphins in Asia. 332 00:50:25,800 --> 00:50:28,800 Since this has not been tested on this species, 333 00:50:28,920 --> 00:50:30,600 there's a little bit of anxiety, 334 00:50:30,720 --> 00:50:32,200 but if they work, 335 00:50:32,320 --> 00:50:33,840 then it's going to be a breakthrough 336 00:50:33,960 --> 00:50:34,920 for conservation. 337 00:50:35,040 --> 00:50:36,440 (SIRENS WAIL) 338 00:50:38,120 --> 00:50:40,840 Uzma has been developing a suitable tag 339 00:50:40,960 --> 00:50:42,960 for over ten years, 340 00:50:43,080 --> 00:50:46,840 and hopes it will help her collect critical data 341 00:50:46,960 --> 00:50:50,920 on how the dolphins are moving through the dams and canals. 342 00:50:51,960 --> 00:50:53,560 But in order to tag, 343 00:50:53,680 --> 00:50:56,920 she will first need a successful rescue. 344 00:51:07,040 --> 00:51:09,240 UZMA KHAN: I'm usually very concerned 345 00:51:09,360 --> 00:51:11,240 when a rescue is happening. 346 00:51:21,320 --> 00:51:23,680 You know the divers, they are very experienced, 347 00:51:23,800 --> 00:51:26,480 but a part of me is always very worried. 348 00:51:28,160 --> 00:51:31,040 They are wild animals that have never been handled. 349 00:51:33,120 --> 00:51:34,520 NICK EASTON: It's really quite a risky thing 350 00:51:34,640 --> 00:51:35,960 that they're undertaking here. 351 00:51:36,080 --> 00:51:37,960 There's a good chance the dolphin might die. 352 00:51:38,080 --> 00:51:39,640 But, of course, they're balancing that 353 00:51:39,760 --> 00:51:41,640 against the fact that they definitely will die 354 00:51:41,760 --> 00:51:42,720 if they stay in here. 355 00:51:42,840 --> 00:51:45,720 So it's a risk they have to take. 356 00:52:01,720 --> 00:52:02,920 CREW: Have they got the dolphin? 357 00:52:03,040 --> 00:52:04,840 Yeah, I think so. They've got it. 358 00:52:08,400 --> 00:52:11,000 DAVID: Now, speed is key. 359 00:52:20,040 --> 00:52:21,800 NICK: We're now bombing across the field 360 00:52:21,920 --> 00:52:23,440 on the way to the release site. 361 00:52:23,560 --> 00:52:25,600 And I think Uzma went ahead of us, so I'm really hopeful 362 00:52:25,720 --> 00:52:28,560 that she'll get her opportunity to tag the dolphin. 363 00:52:32,440 --> 00:52:36,560 But rescue missions don't always go to plan. 364 00:52:36,680 --> 00:52:37,960 (POP) 365 00:52:38,080 --> 00:52:39,440 (AIR HISSES) 366 00:52:44,400 --> 00:52:45,840 (HONKING) 367 00:52:47,080 --> 00:52:48,400 A puncture. 368 00:52:56,160 --> 00:53:00,160 The dolphin is quickly moved to the film crew's truck. 369 00:53:21,080 --> 00:53:23,320 But with no roof for shelter, 370 00:53:23,440 --> 00:53:27,520 the dolphin is at greater risk of dehydration. 371 00:53:27,640 --> 00:53:29,920 ABDULLAH: Stakes are high right now. 372 00:53:30,040 --> 00:53:34,080 It's a cute little animal, and we don't want it to die. 373 00:53:39,120 --> 00:53:43,720 The team re-route to the closest release site. 374 00:53:45,200 --> 00:53:47,480 There can be no more delay. 375 00:53:48,600 --> 00:53:50,640 Uzma calls off the tagging. 376 00:54:09,280 --> 00:54:11,760 It's unfortunate because we were all prepared. 377 00:54:11,880 --> 00:54:15,040 We were very excited since morning, all geared up, 378 00:54:15,160 --> 00:54:17,800 but hopefully we'll get an opportunity 379 00:54:17,920 --> 00:54:19,760 to tag the next rescue. 380 00:54:30,760 --> 00:54:34,720 A few days later, Uzma finally gets her chance. 381 00:54:41,000 --> 00:54:43,920 UZMA: It's a very exciting day for us. 382 00:54:44,040 --> 00:54:46,040 RESCUER: It's OK. 383 00:54:46,160 --> 00:54:49,680 The moment that we have been waiting for over ten years. 384 00:54:50,920 --> 00:54:52,480 UZMA: Just stay calm. 385 00:54:57,920 --> 00:54:59,920 OK. It's good to go. 386 00:55:04,440 --> 00:55:08,080 Congratulations, Mubarak. Well done. 387 00:55:12,600 --> 00:55:16,520 I am very happy, very happy. 388 00:55:16,640 --> 00:55:19,240 I think it's a great accomplishment. 389 00:55:20,760 --> 00:55:23,280 It's the happiest moment of my life. 390 00:55:25,120 --> 00:55:27,480 (RESCUERS CLAP) 391 00:55:30,360 --> 00:55:31,920 DAVID: Within a few weeks, 392 00:55:32,040 --> 00:55:35,960 the tags begin to reveal some new insights. 393 00:55:38,240 --> 00:55:40,120 UZMA: They are moving quite a lot, 394 00:55:40,240 --> 00:55:41,680 which we never expected. 395 00:55:41,800 --> 00:55:44,040 So one of the dolphins actually went 396 00:55:44,160 --> 00:55:46,840 about 46 kilometres upstream 397 00:55:46,960 --> 00:55:48,480 from the release site. 398 00:55:48,600 --> 00:55:51,400 And the other thing is that we thought that they will stay 399 00:55:51,520 --> 00:55:52,920 in the main river stream, 400 00:55:53,040 --> 00:55:55,000 but they are using side channels. 401 00:55:55,120 --> 00:55:56,920 It is extremely interesting. 402 00:55:58,400 --> 00:56:00,800 Tracking the movement of the tagged dolphins 403 00:56:00,920 --> 00:56:03,040 will help Uzma better understand 404 00:56:03,160 --> 00:56:06,760 when and Where they become trapped, 405 00:56:06,880 --> 00:56:12,480 helping safeguard the future of this most endangered animal.