1 00:00:01,880 --> 00:00:04,160 (THEME MUSIC PLAYING) 2 00:00:41,040 --> 00:00:43,790 DAVID ATTENBOROUGH: An olive ridley turtle. 3 00:00:46,040 --> 00:00:50,400 She's resting in the shallows off Costa Rica, 4 00:00:53,240 --> 00:00:56,150 having swum a thousand miles to be here. 5 00:01:06,520 --> 00:01:12,150 All because the eggs she carries must be laid on dry land. 6 00:01:19,360 --> 00:01:22,400 Now she's returned to the very same beach 7 00:01:22,560 --> 00:01:25,200 where she hatched 10 years ago. 8 00:01:34,160 --> 00:01:37,840 She must leave the safety of her marine world 9 00:01:40,480 --> 00:01:43,840 and brave the alien world beyond. 10 00:02:07,920 --> 00:02:09,750 She's heavily laden 11 00:02:10,080 --> 00:02:14,600 but the future of the next generation of her kind is at stake. 12 00:02:22,000 --> 00:02:26,760 All along the beach in a spectacle that has remained unchanged 13 00:02:26,880 --> 00:02:28,470 for millions or years, 14 00:02:29,280 --> 00:02:32,400 mother sea turtles emerge from the ocean 15 00:02:35,280 --> 00:02:37,950 in their hundreds of thousands. 16 00:02:50,080 --> 00:02:53,600 Only those animals that overcome the great challenges 17 00:02:53,680 --> 00:02:55,670 of both land and sea 18 00:02:56,000 --> 00:02:59,760 can make the most of life here on the coast. 19 00:03:25,400 --> 00:03:30,920 Our shores are places of sudden changes and rich rewards. 20 00:03:35,000 --> 00:03:39,040 The Galapagos Islands in the tropical Pacific Ocean. 21 00:03:43,080 --> 00:03:46,470 Their barren coastline looks inhospitable, 22 00:03:46,680 --> 00:03:51,310 but one group of animals has learnt to use it to their advantage. 23 00:03:57,440 --> 00:03:59,110 (EXHALES) 24 00:04:01,600 --> 00:04:03,190 (BOTH BARKING) 25 00:04:03,280 --> 00:04:04,560 Sea lions. 26 00:04:08,720 --> 00:04:10,040 Bachelors. 27 00:04:11,680 --> 00:04:14,120 They need to pile on the pounds 28 00:04:14,240 --> 00:04:18,390 as only the biggest males will attract a female and manage to breed. 29 00:04:23,640 --> 00:04:26,950 If these young bulls fail to grow big enough, 30 00:04:27,640 --> 00:04:31,760 they will remain exiled on this isolated shoreline. 31 00:04:39,240 --> 00:04:43,280 So one hungry young bull heads out alone. 32 00:05:13,600 --> 00:05:16,430 He's on the hunt for big game. 33 00:05:24,720 --> 00:05:26,120 Yellowfin tuna. 34 00:05:29,840 --> 00:05:32,040 Each weighing 60 kilos 35 00:05:34,400 --> 00:05:37,440 with a top speed of 40 miles an hour. 36 00:05:40,840 --> 00:05:44,200 He can't possibly catch one in the open sea, 37 00:05:45,920 --> 00:05:47,910 but he has a plan. 38 00:05:50,640 --> 00:05:53,600 Ahead lies the entrance to the cove. 39 00:05:57,040 --> 00:05:58,840 He herds them towards it 40 00:06:06,640 --> 00:06:08,120 into his trap. 41 00:06:23,520 --> 00:06:26,040 Driving them into a dead end. 42 00:06:31,640 --> 00:06:33,390 But they give him the slip. 43 00:06:40,440 --> 00:06:41,640 (BARKING) 44 00:06:41,720 --> 00:06:43,070 He's failed. 45 00:06:48,280 --> 00:06:50,800 (CONTINUES BARKING) 46 00:06:52,640 --> 00:06:55,920 But there might be another way. 47 00:07:14,320 --> 00:07:16,880 Now they head off as a team 48 00:07:19,760 --> 00:07:22,590 to round up more tuna, 49 00:07:26,440 --> 00:07:28,960 driving them back into the cove. 50 00:07:42,480 --> 00:07:47,510 The sea lions fan out channelling the tuna towards the bottleneck. 51 00:08:05,680 --> 00:08:08,400 Once again the tuna hit the dead end. 52 00:08:09,200 --> 00:08:12,080 But this time, the young bull doubles back 53 00:08:12,160 --> 00:08:15,630 to act as a blocker sealing off the exit. 54 00:08:40,840 --> 00:08:43,640 This time when the shoal tries to escape, 55 00:08:43,720 --> 00:08:47,710 he blocks them and drives them back into the next blind alley. 56 00:09:01,560 --> 00:09:05,110 The gang can now pick them off one by one. 57 00:09:51,040 --> 00:09:53,240 This clever fishing technique, 58 00:09:53,320 --> 00:09:56,870 demanding foresight, planning and cooperation, 59 00:09:57,480 --> 00:10:00,790 has only every been seen here in the Galapagos. 60 00:10:03,880 --> 00:10:08,110 Each massive fish provides them with five times more protein 61 00:10:08,200 --> 00:10:09,950 than a normal day's hunting. 62 00:10:14,760 --> 00:10:18,070 Finally, the young bull leaves his post 63 00:10:21,160 --> 00:10:23,070 to claim his reward. 64 00:10:33,960 --> 00:10:36,680 (SQUAWKING) 65 00:10:38,040 --> 00:10:40,760 On a diet of protein-rich tuna, 66 00:10:40,960 --> 00:10:45,000 he's well on the way to becoming a full-sized breeding bull. 67 00:10:52,840 --> 00:10:54,270 By using this cove, 68 00:10:54,360 --> 00:10:58,750 these Galapagos sea lions have made the most of the opportunities 69 00:10:58,840 --> 00:11:02,520 that occur where the coast's two worlds meet. 70 00:11:11,840 --> 00:11:16,360 Coasts are the most swiftly changing of all ocean habitats 71 00:11:17,680 --> 00:11:20,040 because of the tides. 72 00:11:28,040 --> 00:11:33,160 Tides are created as the moon's gravity pulls at the sea. 73 00:11:43,160 --> 00:11:48,360 As the moon circles our planet, the seas rise and fall. 74 00:11:49,880 --> 00:11:51,790 Typically twice a day, 75 00:11:53,640 --> 00:11:57,950 creating the most constantly dynamic landscapes on Earth. 76 00:12:08,080 --> 00:12:13,550 Nowhere else do sea-living creatures face such changeable conditions. 77 00:12:16,600 --> 00:12:21,280 With the daily risk of drying out and being scorched by the sun. 78 00:12:28,000 --> 00:12:30,750 Where the tide retreats across a rocky shore, 79 00:12:30,880 --> 00:12:34,480 it can leave behind a temporary oasis. 80 00:12:41,920 --> 00:12:43,590 A rock pool. 81 00:12:54,840 --> 00:12:57,800 Seemingly, it's a haven of calm. 82 00:13:00,240 --> 00:13:01,720 But not for long. 83 00:13:03,600 --> 00:13:08,470 Turning minutes into seconds reveals unexpected dramas. 84 00:13:21,640 --> 00:13:26,160 In rock pools, grazers, scavengers and filter feeders 85 00:13:26,240 --> 00:13:28,960 must all make the most of the few short hours 86 00:13:29,040 --> 00:13:30,790 before the tide returns. 87 00:13:47,920 --> 00:13:50,830 Anemones gulp down anything they can reach. 88 00:13:53,240 --> 00:13:56,550 Though some meals are harder to digest than others. 89 00:14:05,760 --> 00:14:10,360 These magical worlds soon become battlegrounds. 90 00:14:13,920 --> 00:14:19,680 A deadly predator with five arms and on the underside a mouth. 91 00:14:23,200 --> 00:14:25,000 The ochre starfish. 92 00:14:29,640 --> 00:14:32,440 And it's in search of limpets. 93 00:14:51,400 --> 00:14:54,120 For some, there is no escape. 94 00:15:04,080 --> 00:15:07,440 But other limpets have a secret defence. 95 00:15:09,840 --> 00:15:12,800 They deploy a slippery shield 96 00:15:15,160 --> 00:15:18,230 which allows them to slide to safety. 97 00:15:23,080 --> 00:15:26,870 And this limpet has its own personal bodyguard. 98 00:15:35,960 --> 00:15:39,160 A scale worm with a nasty nip. 99 00:15:45,120 --> 00:15:49,160 The starfish prefers food that doesn't bite back. 100 00:15:50,640 --> 00:15:52,070 The limpet carries on, 101 00:15:52,160 --> 00:15:55,840 its bodyguard tucked safe under its shell. 102 00:15:59,040 --> 00:16:00,550 But there is one creature 103 00:16:01,280 --> 00:16:04,430 that limpets have no defence against. 104 00:16:06,680 --> 00:16:08,080 A clingfish. 105 00:16:10,480 --> 00:16:14,080 It has teeth that can lever under the shell 106 00:16:15,680 --> 00:16:18,400 and twist the limpet off like a bottle top. 107 00:16:23,160 --> 00:16:25,440 The clingfish then swallows it 108 00:16:26,040 --> 00:16:28,000 shell and all. 109 00:16:30,200 --> 00:16:31,270 (GULPS) 110 00:16:35,760 --> 00:16:40,230 Rock pool dramas like these last just a few short hours 111 00:16:40,320 --> 00:16:42,630 before the tide returns. 112 00:16:46,720 --> 00:16:51,750 Every day the sea becomes land and the land becomes sea. 113 00:16:59,000 --> 00:17:01,360 Bringing new opportunities. 114 00:17:05,800 --> 00:17:07,710 A Sally Lightfoot crab, 115 00:17:10,760 --> 00:17:15,070 one of thousands of shore crabs just waiting for their moment. 116 00:17:18,200 --> 00:17:22,240 Every day they gather on the tropical shores of Brazil, 117 00:17:25,040 --> 00:17:27,790 waiting for the tide to go out. 118 00:17:36,320 --> 00:17:39,120 Which exposes their feeding ground, 119 00:17:40,160 --> 00:17:43,870 seaweed covered rocks, a hundred metres from the shore. 120 00:17:53,840 --> 00:17:57,440 Getting there is a race against the tide. 121 00:18:04,040 --> 00:18:06,080 They leap from rock to rock. 122 00:18:20,160 --> 00:18:23,360 These crabs seem to be afraid of the water. 123 00:18:36,360 --> 00:18:38,320 And for good reason. 124 00:18:50,120 --> 00:18:51,950 The Moray eel. 125 00:18:54,120 --> 00:18:58,080 The chain Moray is a specialist crab hunter. 126 00:19:03,560 --> 00:19:08,190 It's blunt teeth can easily grip and crush a crab's shell. 127 00:19:13,840 --> 00:19:16,070 It's the crab's deadliest enemy. 128 00:19:27,280 --> 00:19:30,830 But the crab's feeding grounds are still a long way off. 129 00:19:37,280 --> 00:19:38,870 They must press on. 130 00:20:01,720 --> 00:20:03,070 Halfway. 131 00:20:08,400 --> 00:20:11,070 But their enemy has other ideas. 132 00:20:16,520 --> 00:20:18,000 Crossing the land 133 00:20:24,600 --> 00:20:27,160 to reset the ambush. 134 00:20:30,560 --> 00:20:33,790 To feed, the crabs must keep going. 135 00:20:40,240 --> 00:20:42,070 But nowhere is safe. 136 00:20:46,320 --> 00:20:49,360 An octopus. Also a crab killer. 137 00:21:14,600 --> 00:21:16,590 The crabs make a dash for it. 138 00:21:43,800 --> 00:21:44,920 Made it. 139 00:21:53,920 --> 00:21:55,720 Risking life and limb 140 00:21:56,040 --> 00:21:59,190 to graze on these seaweed pastures. 141 00:22:02,400 --> 00:22:06,440 But in two hours' time when the tide starts to turn, 142 00:22:07,400 --> 00:22:10,920 they will have to run the gauntlet all over again. 143 00:22:20,440 --> 00:22:24,670 Tides are not the only force to have an impact on the coast. 144 00:22:41,480 --> 00:22:43,870 (WAVES THUNDERING) MkvCage.com 145 00:22:44,640 --> 00:22:48,160 The greatest waves originate far out to sea 146 00:22:48,320 --> 00:22:52,080 and roll in towards the coast, growing as they come. 147 00:23:04,560 --> 00:23:08,790 As the shallowing sea floor drags at their underside, 148 00:23:09,320 --> 00:23:12,550 their crests rise up to a hundred feet high, 149 00:23:12,960 --> 00:23:15,400 topple over and break. 150 00:23:22,840 --> 00:23:25,960 Many of the biggest surfed waves in the world 151 00:23:26,080 --> 00:23:28,830 are formed off Nazare in Portugal. 152 00:23:44,360 --> 00:23:48,880 Every day along this coast, the impact of the waves is equivalent 153 00:23:48,960 --> 00:23:52,920 to one and a half million tonnes of TNT. 154 00:24:14,680 --> 00:24:19,520 Wave power gradually moulds and reshapes our coasts. 155 00:24:23,320 --> 00:24:24,800 In some parts of Europe, 156 00:24:24,920 --> 00:24:29,790 waves wear away as much as three metres of coastline each year. 157 00:24:37,160 --> 00:24:40,280 The rate at which the waves reshape the rock 158 00:24:40,360 --> 00:24:42,270 depends on its hardness. 159 00:24:44,000 --> 00:24:46,600 Where soft rock lies below hard, 160 00:24:46,720 --> 00:24:48,840 dramatic arches are craved. 161 00:25:06,160 --> 00:25:08,150 It's an endless assault 162 00:25:08,240 --> 00:25:12,150 that gradually sculpts vaulted cathedrals of stone 163 00:25:12,240 --> 00:25:14,470 as here in northern Spain. 164 00:25:23,440 --> 00:25:25,960 (BIRDS CHIRPING) 165 00:25:26,040 --> 00:25:29,640 And wave power creates towering fortresses 166 00:25:29,760 --> 00:25:31,800 like these cliffs in these Arctic, 167 00:25:31,880 --> 00:25:35,560 home to tens of thousands of breeding seabirds. 168 00:25:40,120 --> 00:25:44,240 The faces of the cliffs are accessible only from the air 169 00:25:44,360 --> 00:25:48,150 and have plenty of nooks and crannies for those that can get there. 170 00:25:53,240 --> 00:25:58,000 But to feed, seabirds must still master the ocean world beyond. 171 00:26:00,120 --> 00:26:01,840 (GULLS SQUAWING) 172 00:26:03,160 --> 00:26:04,230 The puffin. 173 00:26:08,160 --> 00:26:09,590 He's a fisherman... 174 00:26:09,680 --> 00:26:10,960 (SQUAWKING) 175 00:26:11,040 --> 00:26:12,390 ...and a father. 176 00:26:16,680 --> 00:26:18,990 He has a mate for life. 177 00:26:25,960 --> 00:26:30,000 Both share the burden of raising their week-old chick, 178 00:26:30,080 --> 00:26:34,120 their puffling who needs five square meals a day. 179 00:26:36,760 --> 00:26:39,720 The parents alternate fishing trips. 180 00:26:40,400 --> 00:26:42,040 (CHIRPING) 181 00:26:43,040 --> 00:26:44,680 It's dad's turn. 182 00:26:47,560 --> 00:26:49,230 (SQUAWKING) 183 00:27:07,200 --> 00:27:09,430 When fish stocks are low, 184 00:27:09,520 --> 00:27:13,560 puffins must fly as much as 30 miles 185 00:27:14,800 --> 00:27:17,400 to reach the good fishing grounds. 186 00:27:29,400 --> 00:27:33,360 Once there, they plunge into another world. 187 00:27:41,720 --> 00:27:45,680 Good fishing spots are hard to come by, and they have company. 188 00:27:47,640 --> 00:27:48,960 Guillemots. 189 00:27:56,280 --> 00:28:00,070 Like the puffin, their wings are short and good for diving. 190 00:28:02,960 --> 00:28:05,920 Puffins can hold their breath for over a minute 191 00:28:06,120 --> 00:28:09,080 and dive as deep as 40 metres. 192 00:28:14,320 --> 00:28:15,720 A catch. 193 00:28:34,720 --> 00:28:37,550 But it's a long way home. 194 00:28:40,560 --> 00:28:44,950 (BIRDS SQUAWKING AND CHIRPING) 195 00:28:45,720 --> 00:28:47,070 (SQUAWKING) 196 00:28:50,880 --> 00:28:55,350 After an exhausting round trip of almost 60 miles, 197 00:28:55,520 --> 00:28:57,670 this puffin's nearly made it. 198 00:28:59,960 --> 00:29:02,320 But there are pirates on this coast. 199 00:29:05,840 --> 00:29:07,510 Arctic Skuas. 200 00:29:32,520 --> 00:29:36,040 All around returning parents are being robbed. 201 00:30:02,160 --> 00:30:05,070 The skuas' long rake back wings 202 00:30:05,160 --> 00:30:07,390 make them faster and more manoeuvrable. 203 00:30:45,760 --> 00:30:48,640 Puffins must choose their moment wisely. 204 00:31:09,160 --> 00:31:10,480 A near miss. 205 00:31:28,120 --> 00:31:31,110 A last desperate burst of speed, 206 00:31:33,600 --> 00:31:35,030 and it's made it. 207 00:31:41,040 --> 00:31:46,160 (BIRDS CHIRPING AND SQUAWKING) 208 00:32:01,400 --> 00:32:05,360 Safely home after a three-hour round trip... 209 00:32:10,640 --> 00:32:12,440 (SQUAWKING) 210 00:32:12,720 --> 00:32:15,320 ... where his patient partner is waiting. 211 00:32:19,480 --> 00:32:22,710 (CHIRPING) 212 00:32:31,640 --> 00:32:34,600 Today their puffling will eat. 213 00:32:41,320 --> 00:32:44,070 But where fish numbers are in decline, 214 00:32:44,200 --> 00:32:48,480 many puffins now find it hard to get enough food for their chicks. 215 00:32:51,040 --> 00:32:53,080 In the changing seas of today, 216 00:32:53,200 --> 00:32:57,080 it can be even harder to be a successful puffin parent. 217 00:33:07,880 --> 00:33:12,000 Overcoming the challenges of two worlds is seldom easy. 218 00:33:14,040 --> 00:33:18,590 One marine creature has virtually abandoned the sea altogether. 219 00:33:21,560 --> 00:33:24,230 On a few remote pacific islands, 220 00:33:24,320 --> 00:33:27,790 lives the most terrestrial fish on the planet. 221 00:33:33,720 --> 00:33:37,160 At the top of this metre-high limestone cliff, 222 00:33:40,920 --> 00:33:45,360 an eight-centimetre long blenny has chosen a nest hole. 223 00:33:51,800 --> 00:33:55,160 Up here, he can graze on the abundant algae 224 00:33:55,280 --> 00:33:58,320 without any competition from sea-going fish. 225 00:34:00,120 --> 00:34:02,350 The females are feeding beneath him. 226 00:34:06,640 --> 00:34:09,030 He's keen to attract their attention, 227 00:34:11,880 --> 00:34:14,790 but they are busy moisturising. 228 00:34:15,240 --> 00:34:19,120 Staying damp is essential as they breathe through their skin. 229 00:34:24,120 --> 00:34:28,430 To make himself conspicuous, he turns black 230 00:34:32,680 --> 00:34:35,240 and flashes his orange fin. 231 00:34:37,080 --> 00:34:38,640 He catches her eye. 232 00:34:41,440 --> 00:34:44,240 But these Pacific leaping blennies, 233 00:34:44,360 --> 00:34:47,000 seem afraid of the waves. 234 00:34:50,360 --> 00:34:52,270 They're poor swimmers 235 00:34:53,120 --> 00:34:55,400 and will be easy prey in the sea. 236 00:34:58,120 --> 00:35:00,270 Time to try again. 237 00:35:03,880 --> 00:35:05,080 She's tempted. 238 00:35:10,040 --> 00:35:13,670 But once again distracted by a wave. 239 00:35:37,200 --> 00:35:39,670 The male just won't give up. 240 00:35:52,040 --> 00:35:53,790 Finally, she's hooked. 241 00:35:58,280 --> 00:35:59,790 He makes way... 242 00:36:02,400 --> 00:36:05,150 so she can enter his cave. 243 00:36:09,200 --> 00:36:12,030 And he encourages her to lay her eggs 244 00:36:12,120 --> 00:36:14,760 with his seductive dance. 245 00:36:29,040 --> 00:36:33,320 He then fertilizes them in the safety of his nest. 246 00:36:43,800 --> 00:36:47,840 The blenny has given up the sea for a life on land. 247 00:36:50,160 --> 00:36:54,040 Others have made an even more successful move 248 00:36:54,120 --> 00:36:56,480 but in a different direction. 249 00:37:03,720 --> 00:37:06,280 Penguins have abandoned flying 250 00:37:06,360 --> 00:37:09,800 and instead spend most of their lives swimming. 251 00:37:11,600 --> 00:37:14,880 Their sleek survival suits of tightly packed feathers 252 00:37:14,960 --> 00:37:17,560 are perfect for these freezing waters. 253 00:37:19,480 --> 00:37:22,440 Yet, they must still come ashore once a year. 254 00:37:36,480 --> 00:37:41,320 South Georgia, an island wilderness close to Antarctica. 255 00:37:43,880 --> 00:37:49,240 (PENGUINS SQUAWKING) 256 00:37:51,840 --> 00:37:55,680 Each spring, its beaches become the busiest on Earth 257 00:37:55,760 --> 00:37:59,600 as hundreds of thousands of king penguins return here. 258 00:38:03,760 --> 00:38:07,070 (SQUAWKING) 259 00:38:09,400 --> 00:38:11,200 They're heading for the colony. 260 00:38:14,800 --> 00:38:17,190 (GRUNTING) 261 00:38:18,240 --> 00:38:22,760 But in their way lies the biggest wall of blubber on the planet. 262 00:38:23,200 --> 00:38:26,240 (ROARING) 263 00:38:27,040 --> 00:38:28,920 Elephant seals. 264 00:38:36,640 --> 00:38:38,630 It's the breeding season 265 00:38:38,800 --> 00:38:43,560 and the four-tonne bulls are fighting for control of their harems. 266 00:38:45,280 --> 00:38:46,600 (TRUMPETS) 267 00:38:46,680 --> 00:38:49,240 Best to wait for them to calm down. 268 00:38:50,600 --> 00:38:54,510 (ROARING) 269 00:39:04,120 --> 00:39:06,430 He can't fly over this barrier, 270 00:39:06,520 --> 00:39:10,430 so he will have to walk as unobtrusively as possible. 271 00:39:14,000 --> 00:39:18,280 And hope that sleeping giants will continue to lie. 272 00:39:21,000 --> 00:39:22,590 (SNORES) 273 00:39:29,840 --> 00:39:30,880 Careful. 274 00:39:30,960 --> 00:39:32,080 (SQUAWKS IN FRIGHT) 275 00:39:41,640 --> 00:39:42,760 (SEALS SNORING) 276 00:39:49,520 --> 00:39:51,160 This could be tricky. 277 00:39:53,960 --> 00:39:55,110 (PENGUINS SQUAWKING) 278 00:39:55,200 --> 00:39:57,190 (ROARING) 279 00:40:08,960 --> 00:40:11,520 A rival bull mounts a challenge. 280 00:40:13,600 --> 00:40:16,590 The penguins could be caught in the crossfire. 281 00:40:16,680 --> 00:40:21,960 (ROARING CONTINUES) 282 00:40:47,720 --> 00:40:50,320 Eight tonnes of blubber collide. 283 00:40:54,320 --> 00:40:55,470 (SCREECHES) 284 00:41:11,440 --> 00:41:14,990 The towering beach master is victorious. 285 00:41:22,040 --> 00:41:25,400 In the confusion, this penguin slips through. 286 00:41:28,360 --> 00:41:31,750 Ahead are 40,000 chicks. 287 00:41:35,520 --> 00:41:37,720 Hungry and over-excited. 288 00:41:38,680 --> 00:41:41,670 (ALL CHIRPING) 289 00:41:53,320 --> 00:41:56,390 But not every penguin has a chick to feed. 290 00:41:56,800 --> 00:41:58,710 That's not why they're here. 291 00:42:02,760 --> 00:42:04,640 There is another reason. 292 00:42:06,520 --> 00:42:10,960 There is a trial of endurance that every penguin must face, 293 00:42:12,640 --> 00:42:16,080 and it starts with a persistent itch. 294 00:42:23,320 --> 00:42:25,840 His survival suit has been worn thin 295 00:42:25,920 --> 00:42:28,830 by months of swimming in the rough southern ocean. 296 00:42:31,360 --> 00:42:33,270 His solution is drastic. 297 00:42:37,200 --> 00:42:40,960 Shed all four layers of feathers as quickly as possible. 298 00:42:46,000 --> 00:42:49,630 The process is known as a catastrophic moult. 299 00:42:55,760 --> 00:42:57,990 Until their feathers regrow, 300 00:42:58,120 --> 00:43:01,560 penguins will remain rooted to the spot. 301 00:43:07,960 --> 00:43:10,760 (ALL SQUAWKING) 302 00:43:24,280 --> 00:43:26,430 Having starved for a month, 303 00:43:26,600 --> 00:43:30,910 they're now fully waterproofed and insulated once more. 304 00:43:46,160 --> 00:43:51,630 Lean, hungry and eager to return to a life at sea. 305 00:43:58,120 --> 00:44:00,000 (SQUAWKING) 306 00:44:08,360 --> 00:44:10,670 Thanks to their waterproof plumage, 307 00:44:10,800 --> 00:44:13,840 penguins are able to make the most of both worlds 308 00:44:13,960 --> 00:44:17,160 even in some of the harshest conditions on Earth. 309 00:44:32,640 --> 00:44:34,200 The coasts of South Georgia 310 00:44:34,280 --> 00:44:37,080 are currently protected by their remoteness. 311 00:44:39,640 --> 00:44:42,790 Other coastlines are much more vulnerable, 312 00:44:47,560 --> 00:44:51,190 and they are now changing faster than ever before. 313 00:44:55,760 --> 00:45:00,040 Two thirds of our major cities are on our coasts. 314 00:45:02,800 --> 00:45:05,360 It's estimated that in the next decade, 315 00:45:05,440 --> 00:45:09,960 we can expect 10% of the world's remaining wild shores 316 00:45:10,040 --> 00:45:13,000 to be taken over by human development. 317 00:45:22,240 --> 00:45:25,310 Yet every year, just off Florida 's Palm Beach 318 00:45:26,080 --> 00:45:30,040 and extraordinary spectacle appears almost unnoticed. 319 00:45:36,360 --> 00:45:40,640 The biggest gathering of coastal sharks on the planet. 320 00:45:45,720 --> 00:45:48,390 Spinners and blacktips. 321 00:45:53,480 --> 00:45:55,070 Ten thousand of them. 322 00:46:05,400 --> 00:46:09,110 EveryJanuary, they seek out these warm shallows 323 00:46:09,560 --> 00:46:12,840 as a stopover on their migration northwards. 324 00:46:19,280 --> 00:46:23,990 Sharks have been gathering here since long before people arrived. 325 00:46:34,840 --> 00:46:38,040 But today, they face levels of pollution 326 00:46:38,560 --> 00:46:42,520 and habitat degradation as well as fishing pressures. 327 00:46:42,640 --> 00:46:46,320 that their ancestors would never have experienced. 328 00:46:50,000 --> 00:46:53,200 It's not longer enough for coastal creatures 329 00:46:53,280 --> 00:46:55,590 to master their own worlds. 330 00:47:03,800 --> 00:47:09,510 Now they must face the many challenges that come from our world, too. 331 00:47:32,040 --> 00:47:34,840 To film the most surprising coastal wildlife, 332 00:47:34,960 --> 00:47:36,310 the Blue Planet II team 333 00:47:36,400 --> 00:47:39,310 travelled to some of the remotest shores on the planet. 334 00:47:42,480 --> 00:47:45,520 One destination was the Galapagos islands. 335 00:47:47,080 --> 00:47:50,470 Here they were in search of an almost unbelievable story 336 00:47:50,560 --> 00:47:53,550 brought to them by a local cameraman Richard Wollocombe. 337 00:47:55,080 --> 00:47:56,670 RICHARD: Well, I was talking to a friend of mine 338 00:47:56,760 --> 00:47:57,830 who's a fisherman over here, 339 00:47:57,920 --> 00:48:01,760 and he said that one day he turned up here in this bay, 340 00:48:01,840 --> 00:48:07,150 and suddenly he saw a group of sea lions chasing these massive tuna 341 00:48:07,280 --> 00:48:09,030 up onto the beach. 342 00:48:09,400 --> 00:48:12,280 And I was like, "Yeah, funny one. I don't believe a word of that." 343 00:48:12,400 --> 00:48:14,150 That just sounds too unreal. 344 00:48:14,560 --> 00:48:16,840 Still the lure of the fisherman's tale 345 00:48:16,920 --> 00:48:18,750 was too great to ignore. 346 00:48:19,200 --> 00:48:21,800 RICHARD: I'm a little nervous that if it doesn't happen, 347 00:48:22,120 --> 00:48:23,350 there goes my credibility. 348 00:48:25,960 --> 00:48:29,840 The Blue Planet II team launch a full-scale expedition, 349 00:48:32,240 --> 00:48:34,710 but one of them is still skeptical. 350 00:48:35,200 --> 00:48:37,870 It's gonna be pretty spectacular if... 351 00:48:38,120 --> 00:48:41,110 if a sea lion could actually chase down and kill a tuna. 352 00:48:41,240 --> 00:48:42,910 I'm still yet to be convinced. 353 00:48:44,840 --> 00:48:47,670 They set up camp in this barren cove, 354 00:48:48,280 --> 00:48:51,030 home for the next month. 355 00:48:52,600 --> 00:48:55,510 The local wildlife, famed for its tameness, 356 00:48:55,600 --> 00:48:57,910 is curious to meet its new neighbours. 357 00:48:59,320 --> 00:49:02,390 (SHOOING) 358 00:49:09,160 --> 00:49:11,520 With no sign of the sea lions, 359 00:49:11,600 --> 00:49:15,960 the crew stake out the cove with remote underwater cameras. 360 00:49:18,760 --> 00:49:22,040 Field assistant Roby Pepolas takes first watch. 361 00:49:23,200 --> 00:49:24,600 ROBY: This is the point of view 362 00:49:24,840 --> 00:49:26,880 where we try to see the sea lions come in 363 00:49:27,000 --> 00:49:28,670 jumping over the water. 364 00:49:28,760 --> 00:49:31,070 If they're definitely coming very close, 365 00:49:31,160 --> 00:49:34,790 they say, "Action, action," or "Rock and roll." 366 00:49:34,880 --> 00:49:36,280 (LAUGHS) 367 00:49:38,480 --> 00:49:40,150 Three hours later... 368 00:49:41,560 --> 00:49:45,240 (SPEAKING SPANISH) 369 00:49:46,880 --> 00:49:48,840 The aerial team are first up. 370 00:49:52,160 --> 00:49:54,990 It's a sea lion chasing tuna into the bay. 371 00:50:10,160 --> 00:50:11,800 Oh, he's got it. He's got it. 372 00:50:12,840 --> 00:50:14,160 Unbelievable! 373 00:50:14,360 --> 00:50:16,240 Look at that, he's still struggling. 374 00:50:16,520 --> 00:50:17,950 Holy moly! 375 00:50:20,320 --> 00:50:21,360 He's lost him. 376 00:50:22,080 --> 00:50:24,520 The tuna gives the sea lion the slip. 377 00:50:30,160 --> 00:50:33,600 Over the coming days, more sea lions arrive in the cove 378 00:50:33,680 --> 00:50:35,670 chasing in yellowfin tuna. 379 00:50:38,400 --> 00:50:40,470 RACHEL: Yeah, yeah, yeah, ooh! 380 00:50:41,000 --> 00:50:43,360 I bet you there's more tuna and another sea lion. 381 00:50:43,880 --> 00:50:46,320 There's like six tuna in that bay. 382 00:50:56,040 --> 00:50:58,480 One sea lion has caught Richard's attention, 383 00:50:58,560 --> 00:51:01,790 and he's affectionately called him Tagboy. 384 00:51:02,800 --> 00:51:05,680 RICHARD: He's really different. He's, like, a prolific hunter, 385 00:51:05,800 --> 00:51:07,600 and he's really agile. 386 00:51:08,280 --> 00:51:13,120 It's just fascinating to watch and see the picture emerge about who he is. 387 00:51:14,640 --> 00:51:17,080 From above, the drone is revealing 388 00:51:17,160 --> 00:51:19,680 how the group of sea lions are hunting together. 389 00:51:20,080 --> 00:51:22,070 From the air, we really see the strategy of the sea lion 390 00:51:22,160 --> 00:51:24,880 and see them with their individual roles as well. 391 00:51:25,000 --> 00:51:26,720 Tagboy stays off in the middle of the channel 392 00:51:26,800 --> 00:51:28,360 to make sure none of them escape. 393 00:51:28,440 --> 00:51:29,430 Everyone's got a role 394 00:51:29,520 --> 00:51:31,640 and they're really a team in bringing them together. 395 00:51:32,640 --> 00:51:35,680 Although the sea lions have been hunting in the shallows, 396 00:51:35,760 --> 00:51:39,440 the crew are yet to see them drive a tuna onto the beach. 397 00:51:42,080 --> 00:51:46,390 And to make matters worse, the sea lions aren't alone in this cove. 398 00:51:53,360 --> 00:51:56,350 Galapagos sharks, each two metres long. 399 00:52:00,040 --> 00:52:02,320 The shark almost beached itself 400 00:52:02,400 --> 00:52:05,310 and stole the tuna from the big sea lion, 401 00:52:06,040 --> 00:52:09,030 who is now really angry. 402 00:52:10,800 --> 00:52:12,120 Despite the sharks, 403 00:52:12,240 --> 00:52:16,200 to reveal the full story, Richard needs to get in the water. 404 00:52:17,120 --> 00:52:20,320 RICHARD: Classic shark attack scenario. Blood in the water, shallow, 405 00:52:20,640 --> 00:52:22,520 and easy mistaken identity. 406 00:52:29,160 --> 00:52:30,720 RACHEL: Watch your hands, Roby. 407 00:52:31,360 --> 00:52:34,830 DAVID: The crew gain some protection from chain mail suits. 408 00:52:44,600 --> 00:52:45,830 This is not a shark pool. 409 00:52:45,920 --> 00:52:48,720 One, two, three, four, five, six sharks (CHUCKLES) now. 410 00:52:49,960 --> 00:52:54,640 With so much blood in the water, the sharks go into a feeding frenzy. 411 00:53:08,800 --> 00:53:10,920 RICHARD: Make mince meat of these tuna in seconds. 412 00:53:11,040 --> 00:53:15,480 To be so close to something so unbelievably ferocious 413 00:53:15,880 --> 00:53:18,080 and dangerous, quite frankly, 414 00:53:18,320 --> 00:53:20,200 is amazing. It's... It's... 415 00:53:20,560 --> 00:53:22,870 It's nice to be able to hide behind all this though. 416 00:53:24,960 --> 00:53:28,190 But then, after a week of increasing activity, 417 00:53:28,280 --> 00:53:31,240 the sea lions suddenly stop fishing. 418 00:53:36,640 --> 00:53:37,920 ROBY: It's the first day though 419 00:53:38,000 --> 00:53:40,120 that we haven't seen any action during the whole day. 420 00:53:40,560 --> 00:53:42,360 Since we start. 421 00:53:43,160 --> 00:53:44,800 We are kind of worried. 422 00:53:46,440 --> 00:53:48,400 The tuna have disappeared. 423 00:54:00,240 --> 00:54:01,670 Richard is worried. 424 00:54:02,160 --> 00:54:06,000 The signs are starting to show across the globe 425 00:54:06,240 --> 00:54:08,910 that the seas are warming, they're becoming less productive. 426 00:54:09,440 --> 00:54:13,560 Galapagos marine life relies on cold, deep currents 427 00:54:13,680 --> 00:54:17,200 welling up intermittently to fertilize the surface waters. 428 00:54:17,280 --> 00:54:19,000 (BARKING) 429 00:54:19,080 --> 00:54:21,550 If those upwellings become less consistent, 430 00:54:21,720 --> 00:54:24,080 er, their lives could well be in jeopardy. 431 00:54:25,680 --> 00:54:26,720 In the past, 432 00:54:26,800 --> 00:54:30,030 when these cold water upwellings have temporarily stopped, 433 00:54:30,520 --> 00:54:32,800 many sea lions have starved to death. 434 00:54:33,960 --> 00:54:37,510 And a warming ocean could further weaken these upwellings. 435 00:54:43,080 --> 00:54:46,070 Then after two weeks of nervous waiting, 436 00:54:46,200 --> 00:54:47,480 a hopeful sign. 437 00:54:47,560 --> 00:54:50,550 A thick fog descends over the cove. 438 00:54:51,320 --> 00:54:54,070 We've got very cold water that's come up, upwelled, 439 00:54:54,360 --> 00:54:55,840 and spread across the ocean, 440 00:54:56,320 --> 00:54:58,440 and mixed with the warm air, creating the fog 441 00:54:59,120 --> 00:55:00,950 and hoping that this cold water 442 00:55:01,480 --> 00:55:05,030 willjust kick things off a bit, you know, and get the action going. 443 00:55:05,920 --> 00:55:08,670 As the fog clears, a welcome sight... 444 00:55:09,720 --> 00:55:13,430 The tuna are back with sea lions hot on their heels. 445 00:55:16,720 --> 00:55:18,470 The crew leap into action. 446 00:55:21,760 --> 00:55:24,280 (SPEAKING SPANISH) 447 00:55:27,440 --> 00:55:28,560 Being in the water, 448 00:55:28,640 --> 00:55:32,000 Richard can at last follow the sea lions' teamwork 449 00:55:36,640 --> 00:55:40,350 and finally film Tagboy beaching a tuna. 450 00:55:42,080 --> 00:55:44,830 RICHARD: The know the bottlenecks in this labyrinth. 451 00:55:45,200 --> 00:55:47,350 They know how to push them into those bottlenecks 452 00:55:47,480 --> 00:55:48,800 and threre was just Tagboy, 453 00:55:48,880 --> 00:55:51,520 almost his entire body was blocking the entrance, 454 00:55:51,720 --> 00:55:54,950 and he was just gently back and forth tiring the fish out. 455 00:55:55,560 --> 00:55:58,360 Absolutely extraordinary. Really, really impressive. 456 00:55:59,160 --> 00:56:00,230 Director Rachel 457 00:56:00,320 --> 00:56:03,150 has a newfound respect for the sea lions. 458 00:56:03,560 --> 00:56:05,790 RACHEL: I had no idea they were capable 459 00:56:05,880 --> 00:56:11,110 of this level of planning and strategy and teamwork. 460 00:56:11,240 --> 00:56:13,710 I had no idea they were this intelligent. 461 00:56:15,120 --> 00:56:19,510 Richard has succeeded in filming this unique hunting strategy 462 00:56:19,600 --> 00:56:23,640 and in doing so has proved the fisherman's tale to be true. 463 00:56:24,200 --> 00:56:28,080 RICHARD: The sea lions' intelligence is unbelievably sophisticated. 464 00:56:28,640 --> 00:56:31,110 So to say that my expectations have been exceeded 465 00:56:31,200 --> 00:56:32,600 is a sight understatement. 466 00:56:33,040 --> 00:56:34,760 This is been one of the most remarkable times 467 00:56:34,840 --> 00:56:36,430 I've ever had here in the Galapagos. 468 00:56:47,200 --> 00:56:48,550 Next time... 469 00:56:49,000 --> 00:56:53,600 We travel the world to uncover the biggest issues facing the ocean... 470 00:56:56,720 --> 00:56:58,470 meet the passionate people 471 00:56:58,560 --> 00:57:01,230 who've devoted their lives to protecting it 472 00:57:02,640 --> 00:57:07,400 and discover what the future holds for our blue planet. 473 00:57:10,760 --> 00:57:46,940 (THEME MUSIC PLAYING)