1 00:00:17,601 --> 00:00:19,601 Bear: Three days of digging 2 00:00:19,704 --> 00:00:23,472 And this olive ridley turtle is free, 3 00:00:26,143 --> 00:00:31,180 But not safe, until she gets to the sea, 4 00:00:34,135 --> 00:00:36,869 Where early life evolved and 5 00:00:36,937 --> 00:00:40,973 Where nearly 80% of animals still live. 6 00:00:48,015 --> 00:00:51,834 Of all the hatchlings born this year on the costa rican coast, 7 00:00:53,204 --> 00:00:56,538 Only 10% will make it. 8 00:01:18,012 --> 00:01:24,299 ♪ ♪ 9 00:01:57,501 --> 00:02:01,103 Now she's in her element. 10 00:02:03,607 --> 00:02:07,509 But her journey has just begun. 11 00:02:08,913 --> 00:02:12,181 In ten years' time, she will return to these shores 12 00:02:12,283 --> 00:02:14,700 To lay eggs of her own, 13 00:02:15,436 --> 00:02:18,270 If she survives. 14 00:02:24,778 --> 00:02:28,480 The ocean is a fluid and unpredictable world, 15 00:02:30,267 --> 00:02:34,403 And all those that live here are at its mercy. 16 00:02:35,773 --> 00:02:42,144 (theme music plays). 17 00:02:52,940 --> 00:02:56,241 Our planet's oceans cover 70% of its surface, 18 00:03:00,848 --> 00:03:05,801 And provide an incredible 99% of its habitable space. 19 00:03:07,338 --> 00:03:10,005 This may be an alien world to us, 20 00:03:11,575 --> 00:03:15,110 But it's home to an extraordinary range of animals, 21 00:03:21,168 --> 00:03:23,735 From the biggest, 22 00:03:23,837 --> 00:03:27,306 To the strangest creatures in our world. 23 00:03:29,176 --> 00:03:31,910 Even for the most marine adapted, 24 00:03:32,012 --> 00:03:35,047 Life isn't easy. 25 00:03:41,438 --> 00:03:45,073 Survival at sea is a completely different game 26 00:03:45,175 --> 00:03:48,310 To survival on land, 27 00:03:51,048 --> 00:03:54,733 Especially when the rules keep changing. 28 00:04:10,717 --> 00:04:14,536 Where the atlantic and indian oceans meet, 29 00:04:14,872 --> 00:04:19,041 New conflicts between old foes are brewing. 30 00:04:23,747 --> 00:04:26,815 Rising sea temperatures are pushing fish eastward 31 00:04:26,917 --> 00:04:29,334 To cooler waters. 32 00:04:40,547 --> 00:04:43,932 Those that feed on them have followed. 33 00:04:49,907 --> 00:04:52,908 Fur seals. 34 00:04:56,747 --> 00:05:00,148 Their new home is treacherous, 35 00:05:01,635 --> 00:05:04,736 And it's not just the waves, 36 00:05:06,974 --> 00:05:09,841 It's what lies beneath. 37 00:05:25,943 --> 00:05:29,611 Not the best place to learn to swim, 38 00:05:32,783 --> 00:05:37,069 But the perfect hunting ground for a great white shark. 39 00:05:55,973 --> 00:06:00,042 This pup has strayed too close to the edge. 40 00:06:09,703 --> 00:06:13,372 Now it's out of its depth. 41 00:06:28,539 --> 00:06:31,740 A pup can outmaneuver a shark, 42 00:06:37,214 --> 00:06:40,182 But only for so long. 43 00:06:56,483 --> 00:07:00,735 Half of all such encounters end badly for seals. 44 00:07:01,572 --> 00:07:06,875 (barking). 45 00:07:08,846 --> 00:07:12,948 The adults must deal with this persistent menace, 46 00:07:14,902 --> 00:07:17,602 But how? 47 00:07:25,412 --> 00:07:29,347 It takes one brave seal to lead the way. 48 00:07:49,069 --> 00:07:51,703 Others join. 49 00:07:54,074 --> 00:07:58,710 Soon they are a mob, harassing the intruder. 50 00:08:03,250 --> 00:08:07,469 It's a risky strategy; sharks can turn on a dime. 51 00:08:30,677 --> 00:08:34,713 Together they have overcome a giant. 52 00:08:41,738 --> 00:08:46,174 The pups are safe, at least for now. 53 00:08:58,405 --> 00:09:02,274 Shallow continental seas are the most productive waters in 54 00:09:02,376 --> 00:09:04,709 Our oceans. 55 00:09:06,580 --> 00:09:09,581 They are also some of the most competitive. 56 00:09:19,643 --> 00:09:23,812 During winter, these freezing fjords are the stage for one 57 00:09:23,914 --> 00:09:28,133 Of the biggest wildlife spectacles on the planet. 58 00:09:34,274 --> 00:09:38,610 This orca pod comes here every year. 59 00:09:39,913 --> 00:09:42,747 They're led by a matriarch; 60 00:09:43,850 --> 00:09:47,402 She could be 70 years old. 61 00:09:51,408 --> 00:09:54,476 For a pod that specialize in hunting fish, 62 00:09:54,578 --> 00:09:57,946 This is an unmissable event. 63 00:10:02,869 --> 00:10:04,369 Herring. 64 00:10:04,471 --> 00:10:07,138 Billions of them. 65 00:10:07,240 --> 00:10:11,343 More fish here than people on the planet. 66 00:10:19,403 --> 00:10:21,236 But the bigger the shoal, 67 00:10:21,338 --> 00:10:24,939 The harder it is to single out a target. 68 00:10:28,845 --> 00:10:32,347 The orca need to come at the problem from another angle. 69 00:10:43,243 --> 00:10:47,746 Coordinating their attack, they divide and conquer. 70 00:10:51,401 --> 00:10:55,370 Herders work to split the shoal. 71 00:11:00,143 --> 00:11:03,445 Then in come the big hitters, 72 00:11:03,947 --> 00:11:07,248 Slamming their tails, creating a shockwave, 73 00:11:08,635 --> 00:11:12,270 Stunning up to 30 fish with each blow. 74 00:11:23,116 --> 00:11:25,100 They must work quickly. 75 00:11:25,202 --> 00:11:27,869 They're not the only hunters here. 76 00:11:33,310 --> 00:11:38,246 Humpbacks, six times the weight of an orca. 77 00:11:43,637 --> 00:11:48,440 They can devour more than 200 pounds of herring in one gulp. 78 00:11:59,603 --> 00:12:03,338 The orca simply can't compete. 79 00:12:06,877 --> 00:12:10,512 But they can switch tactic, 80 00:12:12,015 --> 00:12:14,599 As long as they're prepared to face down 81 00:12:14,701 --> 00:12:17,635 The most dangerous predator in the ocean. 82 00:12:25,512 --> 00:12:27,879 Bear: In the ocean, where there is food, 83 00:12:27,981 --> 00:12:31,232 There's usually a fight. 84 00:12:34,438 --> 00:12:38,273 Off the fjords of norway, these orca are about to take 85 00:12:38,375 --> 00:12:41,543 On the most aggressive ocean hunters of all, 86 00:12:47,284 --> 00:12:49,467 Us. 87 00:12:56,610 --> 00:12:58,877 Fishing boats like this can scoop up 88 00:12:58,979 --> 00:13:02,447 800 tons of herring a day, 89 00:13:03,850 --> 00:13:07,168 Out-fishing orca and humpbacks combined. 90 00:13:10,273 --> 00:13:13,074 Desperation has forced these orca 91 00:13:13,176 --> 00:13:16,644 To turn this new obstacle into opportunity, 92 00:13:26,706 --> 00:13:28,873 Picking off the fish that slip through 93 00:13:28,975 --> 00:13:32,210 Their competitors' nets. 94 00:13:42,205 --> 00:13:46,174 Recently imposed quotas ensure there are enough herring for 95 00:13:46,276 --> 00:13:49,711 Humans and whales. 96 00:13:55,535 --> 00:13:59,204 But the global picture isn't so bright. 97 00:14:08,448 --> 00:14:13,034 We are consuming more fish than ever before. 98 00:14:14,571 --> 00:14:18,940 Reducing many stocks to little more than scales. 99 00:14:25,949 --> 00:14:30,335 Unbalanced oceans are open to invasion, 100 00:14:32,005 --> 00:14:35,373 By strange life forms. 101 00:14:50,073 --> 00:14:54,175 They start life as pinhead sized polyps, 102 00:14:57,681 --> 00:15:03,134 But what they lack in size they make up for in numbers. 103 00:15:23,673 --> 00:15:27,842 Gorging on tiny plankton, 104 00:15:28,945 --> 00:15:34,832 They grow, mutate and multiply 105 00:15:37,504 --> 00:15:40,638 Into an army of clones. 106 00:15:44,511 --> 00:15:47,779 Now each polyp becomes a production line 107 00:15:48,648 --> 00:15:51,666 With one purpose. 108 00:16:13,239 --> 00:16:17,375 Creating new jellyfish. 109 00:16:23,149 --> 00:16:26,801 Bodies that are 95% water 110 00:16:26,903 --> 00:16:31,005 Can easily grow and grow, 111 00:16:33,410 --> 00:16:37,545 Until they are monsters. 112 00:16:42,569 --> 00:16:46,704 No bones, no blood or even brains, 113 00:16:47,407 --> 00:16:51,809 But perfectly suited to today's transforming seas. 114 00:16:55,982 --> 00:16:58,933 Resistant to increasing temperature, 115 00:16:59,035 --> 00:17:02,370 Decreasing oxygen, changing salinity, 116 00:17:02,472 --> 00:17:06,974 Rising acidity, even plastic pollution. 117 00:17:10,980 --> 00:17:14,565 When a jellyfish swarm takes over, 118 00:17:14,667 --> 00:17:18,836 Some ecosystems never fully recover. 119 00:17:25,478 --> 00:17:30,581 Our impact also extends to the biggest marine habitat of all. 120 00:17:36,372 --> 00:17:40,007 The open ocean. 121 00:17:50,303 --> 00:17:53,404 It covers more than half the globe, 122 00:17:54,140 --> 00:17:57,375 But food here is increasingly scarce. 123 00:18:00,847 --> 00:18:05,733 Yet one animal perseveres, despite needing 124 00:18:05,835 --> 00:18:10,371 One and a half million calories every day. 125 00:18:20,450 --> 00:18:25,703 The blue whale, the largest animal ever to have lived. 126 00:18:29,209 --> 00:18:31,943 She's as long as an 18 wheeler, 127 00:18:32,045 --> 00:18:35,113 With a heart as big as a car 128 00:18:35,215 --> 00:18:38,966 And a tongue that weighs as much as an elephant. 129 00:18:51,047 --> 00:18:54,599 Just this year, she's swum far enough to have 130 00:18:54,701 --> 00:18:58,736 Circumnavigated the globe. 131 00:18:59,439 --> 00:19:03,407 All in search of this. 132 00:19:06,179 --> 00:19:08,646 Krill. 133 00:19:08,748 --> 00:19:10,781 One of the most important species 134 00:19:10,884 --> 00:19:13,901 In the marine food chain. 135 00:19:24,414 --> 00:19:28,966 With each monumental gulp, she takes in enough water and 136 00:19:29,068 --> 00:19:33,104 Krill to fill a school bus. 137 00:19:35,608 --> 00:19:38,843 Her tongue forces the water back out through the bristly 138 00:19:38,945 --> 00:19:43,881 Plates on her jaw, trapping up to two million krill. 139 00:19:53,276 --> 00:19:57,778 Blue whales were hunted to the brink of extinction. 140 00:19:59,048 --> 00:20:01,465 Although they're still endangered, 141 00:20:01,568 --> 00:20:04,468 Since a ban on whaling in the 1960s, 142 00:20:04,571 --> 00:20:08,105 Their numbers have increased worldwide, 143 00:20:09,943 --> 00:20:12,977 And here, off the coast of california, 144 00:20:13,079 --> 00:20:16,614 They have almost completely recovered. 145 00:20:23,106 --> 00:20:27,942 The vast, open ocean can be a lonely place. 146 00:20:38,137 --> 00:20:43,608 This green turtle has spent 30 years out here on her own. 147 00:20:45,245 --> 00:20:50,281 Somehow, she's found enough food to survive and grow. 148 00:20:57,440 --> 00:21:01,175 Now she's ready to return home, 149 00:21:03,513 --> 00:21:07,448 But it will be a dangerous journey. 150 00:21:24,350 --> 00:21:28,202 It's the breeding season, and hundreds of turtles are 151 00:21:28,304 --> 00:21:32,073 Gathering to try and win a partner. 152 00:21:35,511 --> 00:21:40,448 Males mate about four times as often as females, 153 00:21:41,350 --> 00:21:45,169 So she attracts a lot of interest. 154 00:21:59,669 --> 00:22:03,204 This male is quick to latch on. 155 00:22:07,076 --> 00:22:10,578 But the others won't give up without a fight. 156 00:22:20,506 --> 00:22:22,740 Bear: Off the coast of malaysia, 157 00:22:22,842 --> 00:22:26,544 It's green turtle breeding season. 158 00:22:27,680 --> 00:22:30,848 This female has found a mate, 159 00:22:31,834 --> 00:22:35,970 But other males are intent on splitting the pair. 160 00:22:45,848 --> 00:22:48,933 Targeting the male's soft flesh, 161 00:22:49,035 --> 00:22:52,002 They try to force him to let go. 162 00:23:01,080 --> 00:23:04,982 But the female has the most to lose. 163 00:23:06,402 --> 00:23:10,704 The fiercer the pursuit, the more oxygen she burns. 164 00:23:12,942 --> 00:23:16,544 A stressed turtle can drown in minutes. 165 00:23:31,411 --> 00:23:35,246 She's desperate to reach the surface and breathe, 166 00:23:35,681 --> 00:23:39,900 But one challenger just won't give up. 167 00:24:09,482 --> 00:24:12,600 The female is running on empty. 168 00:24:23,146 --> 00:24:27,081 Finally, the intruder backs off just long enough. 169 00:24:55,811 --> 00:25:00,381 She's safe, but in just a few weeks she will face the final 170 00:25:00,550 --> 00:25:04,835 Hurdle in her epic struggle to continue her line. 171 00:25:14,547 --> 00:25:18,115 Where the tropical sun meets the shallow seas, 172 00:25:18,184 --> 00:25:21,969 You find the busiest ocean habitat of all: 173 00:25:24,273 --> 00:25:27,007 Coral reefs. 174 00:25:29,712 --> 00:25:33,380 They account for less than a thousandth of the sea floor, 175 00:25:35,201 --> 00:25:40,004 But are home to a quarter of all marine species. 176 00:25:52,868 --> 00:25:56,470 In this crowded and dangerous place, 177 00:25:56,939 --> 00:26:00,107 Finding shelter is essential. 178 00:26:09,235 --> 00:26:12,903 Some hide in the coral maze, 179 00:26:14,340 --> 00:26:18,275 Others seek sanctuary in the shoal. 180 00:26:25,401 --> 00:26:29,270 But neither tactic guarantees safety. 181 00:26:35,244 --> 00:26:39,580 Lionfish are one of the most efficient killers on the reef. 182 00:27:09,178 --> 00:27:12,079 Yet there is a far greater threat facing 183 00:27:12,181 --> 00:27:15,466 All those who live here. 184 00:27:19,739 --> 00:27:24,808 Our seas have been steadily warming for the past 75 years. 185 00:27:31,017 --> 00:27:35,502 Now it's happening faster than ever before. 186 00:27:41,477 --> 00:27:46,447 It's having a profound impact on life throughout our oceans. 187 00:27:49,969 --> 00:27:54,238 Coral reefs are particularly vulnerable. 188 00:27:55,141 --> 00:27:59,009 Just a 3 degree temperature rise is too much for coral. 189 00:28:03,082 --> 00:28:06,900 It forces them to expel the algae that feed them 190 00:28:07,269 --> 00:28:10,404 And give them their color. 191 00:28:13,409 --> 00:28:16,110 This bleaching is the first step towards an 192 00:28:16,212 --> 00:28:20,381 Almost irreversible demise. 193 00:28:26,138 --> 00:28:32,009 Unless temperatures drop, the reef becomes a wasteland. 194 00:28:37,216 --> 00:28:39,433 In three decades, 195 00:28:39,535 --> 00:28:43,237 We've lost over a quarter of the world's corals, 196 00:28:44,340 --> 00:28:48,976 Home to around 4000 species of fish. 197 00:28:50,579 --> 00:28:54,515 If warming continues, we could lose the rest. 198 00:29:03,976 --> 00:29:06,877 Even those that live far below aren't safe from 199 00:29:06,979 --> 00:29:10,314 Rising ocean temperatures. 200 00:29:13,135 --> 00:29:16,170 Opalescent squid. 201 00:29:21,026 --> 00:29:25,179 In the past few years, warming seas disrupted their mating 202 00:29:25,281 --> 00:29:29,366 Habits, and their numbers have fallen dramatically. 203 00:29:33,289 --> 00:29:37,207 But this year, an influx of cold water has revived 204 00:29:37,309 --> 00:29:40,210 Their breeding ritual. 205 00:29:50,072 --> 00:29:54,107 A trip to the shallows to mate by moonlight. 206 00:29:57,980 --> 00:30:01,782 Males grab the females and fertilize their eggs, 207 00:30:05,271 --> 00:30:08,806 Which are then deposited on the sea floor. 208 00:30:11,644 --> 00:30:14,711 It's a brief and brutal affair. 209 00:30:21,704 --> 00:30:25,906 Within days of mating they will all die. 210 00:30:31,981 --> 00:30:35,566 But their legacy lives on. 211 00:30:38,854 --> 00:30:43,607 Each capsule contains up to 300 new lives. 212 00:30:48,214 --> 00:30:51,715 One successful breeding season can go a long way towards 213 00:30:51,817 --> 00:30:56,136 Reversing their recent bad fortunes. 214 00:31:00,342 --> 00:31:04,111 Those still alive retreat back to a place beyond 215 00:31:04,213 --> 00:31:07,314 The reach of the sun, 216 00:31:12,538 --> 00:31:16,206 Where crushing pressures have morphed bodies, 217 00:31:18,544 --> 00:31:21,478 Into the stuff of nightmares. 218 00:31:30,372 --> 00:31:34,074 Bear: To reach one of the most hostile environments on earth, 219 00:31:35,010 --> 00:31:38,812 You must descend thousands of feet, 220 00:31:40,883 --> 00:31:46,603 Beyond the sun's reach, down into the ocean's depths. 221 00:31:49,041 --> 00:31:53,110 The pressure here would crush you like a soda can. 222 00:31:58,550 --> 00:32:02,369 There is life, just not as we know it. 223 00:32:06,442 --> 00:32:10,677 75% of animals make their own light. 224 00:32:11,914 --> 00:32:14,848 Eyes are super-sized 225 00:32:14,950 --> 00:32:18,335 To catch what tiny luminescence there is, 226 00:32:20,906 --> 00:32:24,341 And soft bodies dominate. 227 00:32:29,014 --> 00:32:32,899 In this vast, abyssal wilderness, 228 00:32:34,103 --> 00:32:38,405 One of the toughest trials is finding a mate. 229 00:32:41,143 --> 00:32:45,412 Angler fish have a grizzly solution. 230 00:32:46,115 --> 00:32:49,299 This giant female's tiny hanger-on 231 00:32:49,401 --> 00:32:52,936 Is a male angler fish. 232 00:32:54,940 --> 00:32:58,775 Many males never find a mate. 233 00:32:59,445 --> 00:33:03,714 Those that do, never let go. 234 00:33:05,184 --> 00:33:08,735 His mouth fuses with her very tissue. 235 00:33:08,837 --> 00:33:12,172 His only nourishment, her blood. 236 00:33:13,942 --> 00:33:17,678 Bonded for life. 237 00:33:23,002 --> 00:33:26,837 This alien environment is full of surprises. 238 00:33:30,676 --> 00:33:34,111 It even snows down here. 239 00:33:35,748 --> 00:33:38,715 Flakes of organic matter fall for weeks 240 00:33:38,801 --> 00:33:42,736 Towards the sea floor. 241 00:33:44,840 --> 00:33:47,741 Along the way, they fuel an ecosystem of 242 00:33:47,843 --> 00:33:52,946 Microscopic animals and graceful giants. 243 00:33:58,637 --> 00:34:02,572 The stygiomedusa jellyfish. 244 00:34:04,576 --> 00:34:09,479 Its ribbon-like arms extend up to 30 feet to absorb tiny 245 00:34:09,581 --> 00:34:14,868 Planktonic creatures, or so we believe. 246 00:34:16,805 --> 00:34:20,807 Even today, the lives of these deep-sea monsters 247 00:34:20,909 --> 00:34:25,145 Remain shrouded in mystery. 248 00:34:27,583 --> 00:34:31,334 But the biggest surprise of all, 249 00:34:32,304 --> 00:34:34,771 This marine underworld is one of the most 250 00:34:34,873 --> 00:34:37,908 Stable habitats on the planet, 251 00:34:40,913 --> 00:34:44,948 Out of touch with what's happening far above. 252 00:35:01,817 --> 00:35:05,268 The sun has fueled a monster. 253 00:35:08,941 --> 00:35:13,710 It heats surface waters until they evaporate and build into 254 00:35:13,812 --> 00:35:18,315 Oceanic storms that render humans powerless. 255 00:35:22,971 --> 00:35:26,039 And when conditions are just right, 256 00:35:26,141 --> 00:35:29,176 They grow into one of the most formidable forces 257 00:35:29,278 --> 00:35:31,711 On the planet: 258 00:35:37,603 --> 00:35:40,237 Hurricanes. 259 00:35:40,973 --> 00:35:43,206 They form over tropical seas, 260 00:35:43,308 --> 00:35:46,309 Then their devastation spreads. 261 00:35:47,980 --> 00:35:51,214 They release so much energy that just one could power 262 00:35:51,316 --> 00:35:54,901 Our entire planet for a week. 263 00:35:56,805 --> 00:35:58,872 And as global temperatures rise, 264 00:35:58,974 --> 00:36:01,942 Hurricanes are growing stronger. 265 00:36:16,375 --> 00:36:20,277 This is the calm before the storm. 266 00:36:21,213 --> 00:36:24,881 Most people are already taking shelter. 267 00:36:26,668 --> 00:36:31,137 But just off shore, others are on the move. 268 00:36:35,777 --> 00:36:39,312 Mullet in their millions. 269 00:36:42,768 --> 00:36:45,769 Few have heard of it, but this is one of the 270 00:36:45,871 --> 00:36:50,140 Largest gatherings of any animal in the united states. 271 00:36:52,878 --> 00:36:56,246 The mullet need to reach their spawning grounds 272 00:36:56,348 --> 00:37:00,166 Further south before temperatures drop too low. 273 00:37:05,240 --> 00:37:09,676 Such a mass of fish in the sea doesn't go unnoticed. 274 00:37:20,272 --> 00:37:24,941 Expert hunters attack the shoal from every angle. 275 00:37:28,614 --> 00:37:32,565 Below are the tarpon and blacktip sharks. 276 00:37:40,242 --> 00:37:45,845 Above, pelicans, and osprey. 277 00:38:09,171 --> 00:38:13,073 As the waves are whipped up by the approaching storm, 278 00:38:13,175 --> 00:38:16,409 The pendulum swings in the mullet's favor. 279 00:38:24,002 --> 00:38:27,304 In the turbulent, shallow water, 280 00:38:27,406 --> 00:38:31,107 They're harder to target. 281 00:38:38,016 --> 00:38:41,801 Finally, the swells grow too powerful, 282 00:38:45,173 --> 00:38:48,808 As the storm makes landfall. 283 00:38:58,103 --> 00:39:01,638 Along the coast, ocean storms create some of 284 00:39:01,740 --> 00:39:05,542 Nature's most awe inspiring wonders. 285 00:39:12,901 --> 00:39:14,934 Nazaré in portugal 286 00:39:15,053 --> 00:39:18,338 Sees some of the biggest waves in the world, 287 00:39:22,911 --> 00:39:26,046 Towering as high as ten stories. 288 00:40:04,369 --> 00:40:07,771 But the stormier our seas become, 289 00:40:07,873 --> 00:40:11,674 The more those living on the coast suffer. 290 00:40:19,568 --> 00:40:23,369 An island on the edge of existence. 291 00:40:29,578 --> 00:40:32,912 Home to rockhopper penguins. 292 00:40:37,002 --> 00:40:40,804 A dense layer of fat gives them some protection. 293 00:40:43,241 --> 00:40:46,543 Still they take a battering. 294 00:40:54,903 --> 00:40:58,505 This mother can't back out now. 295 00:41:04,479 --> 00:41:07,647 Her chick needs food. 296 00:41:20,445 --> 00:41:23,980 And its dad's turn to hold the fort. 297 00:41:29,437 --> 00:41:32,739 Life in the colony is tough. 298 00:41:33,308 --> 00:41:36,376 Declining fish stocks and rougher seas 299 00:41:36,478 --> 00:41:40,146 Have made food harder to come by. 300 00:41:49,107 --> 00:41:51,608 Mum has to hunt, 301 00:41:54,145 --> 00:41:57,413 And what was already a rough sea 302 00:41:58,316 --> 00:42:02,035 Is about to get a whole lot rougher. 303 00:42:19,037 --> 00:42:23,673 The most powerful storm in almost 30 years is closing in. 304 00:42:26,344 --> 00:42:30,446 Worse than anything these penguins have faced before. 305 00:42:41,109 --> 00:42:43,943 Bear: On the far south of the globe, 306 00:42:44,045 --> 00:42:47,480 A brutal storm is finally subsiding. 307 00:42:49,601 --> 00:42:51,935 But for these rockhopper penguins, 308 00:42:52,037 --> 00:42:54,938 The waves are still deadly. 309 00:43:03,248 --> 00:43:06,566 The latest shift of hunters returns. 310 00:43:20,615 --> 00:43:25,034 But this chick's mum is nowhere to be seen. 311 00:43:28,940 --> 00:43:32,842 Then, she appears. 312 00:43:36,081 --> 00:43:39,282 Amongst the last stragglers. 313 00:44:02,674 --> 00:44:09,345 ♪ ♪ 314 00:44:45,750 --> 00:44:49,068 Home and dry. 315 00:44:54,509 --> 00:45:00,480 (squawking, peeping). 316 00:45:14,379 --> 00:45:18,981 In just 12 hours, she'll return to battle the waves. 317 00:45:22,971 --> 00:45:26,906 And risk her life for her chick once more. 318 00:45:38,069 --> 00:45:40,069 Right from the very beginning, 319 00:45:40,171 --> 00:45:43,473 The ocean has been a cradle of life on our planet, 320 00:45:43,575 --> 00:45:46,209 And the many creatures that still live here are 321 00:45:46,311 --> 00:45:50,113 Really a legacy of that irrepressible will to 322 00:45:50,215 --> 00:45:53,132 Succeed in a turbulent world. 323 00:45:53,234 --> 00:45:56,302 No matter what the ocean has thrown at them, 324 00:45:56,404 --> 00:45:59,505 Somehow they've managed to endure. 325 00:46:06,714 --> 00:46:11,200 Against near impossible odds, this mum-to-be has found her 326 00:46:11,302 --> 00:46:15,772 Way back to the beach where she was born. 327 00:46:20,645 --> 00:46:23,513 It's the first time she's been on land 328 00:46:23,615 --> 00:46:26,532 Since hatching over a decade ago, 329 00:46:28,536 --> 00:46:31,437 And she's not alone. 330 00:46:36,444 --> 00:46:40,646 Hundreds of thousands of female olive ridley turtles 331 00:46:40,748 --> 00:46:43,666 Are returning to the costa rican coastline 332 00:46:43,768 --> 00:46:46,469 To lay their eggs. 333 00:46:51,609 --> 00:46:56,813 A cycle of life sustained by the sea for 30 million years. 334 00:47:01,369 --> 00:47:05,171 Never has their journey been harder, 335 00:47:06,040 --> 00:47:08,774 Yet so far, these turtles are still 336 00:47:08,877 --> 00:47:13,112 Holding on in these fast changing times. 337 00:47:18,670 --> 00:47:19,969 Captioned by cotter captioning services.