1 00:00:03,400 --> 00:00:06,120 Oh, my. It feels like we're on top of the world. 2 00:00:12,680 --> 00:00:16,380 I'm going in search of the vast, remote areas 3 00:00:16,380 --> 00:00:18,680 where nature still has the upper hand. 4 00:00:19,440 --> 00:00:23,040 This is the source of the mighty Yukon River. 5 00:00:24,800 --> 00:00:26,980 Whoa, I nearly went then! 6 00:00:26,980 --> 00:00:30,120 Rarely visited, distant, wild places. 7 00:00:30,120 --> 00:00:32,080 - One, two, three, go! 8 00:00:33,840 --> 00:00:37,680 - I'm exploring four of these rugged, glorious regions. 9 00:00:37,680 --> 00:00:40,120 This is straight out of Star Wars. 10 00:00:40,120 --> 00:00:42,080 Tough journeys... 11 00:00:42,080 --> 00:00:44,120 Come on! 12 00:00:44,120 --> 00:00:46,240 I don't know how much longer I can do this. 13 00:00:47,400 --> 00:00:48,920 ..over harsh terrain. 14 00:00:48,920 --> 00:00:51,200 BLEEP Argh! 15 00:00:51,200 --> 00:00:52,960 This is becoming one of the least pleasant 16 00:00:52,960 --> 00:00:55,480 camping experiences of my life. 17 00:00:55,480 --> 00:00:57,280 Thank you very much. Thank you. 18 00:00:57,280 --> 00:01:00,760 I'm going to find the people of the wilderness... 19 00:01:00,760 --> 00:01:02,520 I can sense the emotion in him. 20 00:01:04,040 --> 00:01:06,120 This is a tough guy. 21 00:01:06,120 --> 00:01:08,200 Whoa! Whoa! 22 00:01:09,760 --> 00:01:11,440 Thank you so much. 23 00:01:11,440 --> 00:01:14,160 ..and discover they're defending wild areas. 24 00:01:14,160 --> 00:01:15,800 This is brilliant. 25 00:01:18,960 --> 00:01:21,120 The apex predators are back. 26 00:01:22,320 --> 00:01:24,480 There it is! It's a snow leopard! 27 00:01:25,960 --> 00:01:29,360 It is a vast ocean of sand and snow. 28 00:01:29,360 --> 00:01:31,480 I'm crossing some of the most hostile 29 00:01:31,480 --> 00:01:33,560 and spectacular landscapes... 30 00:01:33,560 --> 00:01:34,800 Oh! What a sight. 31 00:01:34,800 --> 00:01:36,280 ..on planet Earth. 32 00:01:37,880 --> 00:01:40,680 These are the last great wildernesses. 33 00:01:54,400 --> 00:01:56,800 I'm in western Mexico, 34 00:01:56,800 --> 00:02:01,120 exploring a unique and often overlooked corner of our planet. 35 00:02:03,840 --> 00:02:07,760 It's hot as hell here much of the year, and parched, 36 00:02:07,760 --> 00:02:10,560 but there's still loads of life. 37 00:02:10,560 --> 00:02:12,560 Look at this giant. 38 00:02:14,160 --> 00:02:16,880 This is the great Sonora Desert, 39 00:02:16,880 --> 00:02:20,240 a landscape of sand and giant cactuses 40 00:02:20,240 --> 00:02:22,360 that can live for more than 200 years. 41 00:02:24,080 --> 00:02:27,760 And ahead of me is a huge, glorious wild sea... 42 00:02:32,160 --> 00:02:35,800 ..created by a great tear in the Earth's crust. 43 00:02:35,800 --> 00:02:38,720 More than 60,000 square miles. 44 00:02:38,720 --> 00:02:41,360 In places, a staggering two miles deep. 45 00:02:44,120 --> 00:02:46,400 This is the Sea of Cortez. 46 00:02:50,200 --> 00:02:52,640 Jose! HE LAUGHS 47 00:03:01,040 --> 00:03:04,280 Hola! Hello, mate. Lovely to meet you. Mucho gusto. 48 00:03:05,640 --> 00:03:09,440 So this is really where the journey begins. 49 00:03:09,440 --> 00:03:11,080 We're going to head out. 50 00:03:13,120 --> 00:03:14,640 Oh, gracias. 51 00:03:18,520 --> 00:03:19,720 OK, Jose? 52 00:03:23,000 --> 00:03:28,680 So this is the Sea of Cortez, also known as the Gulf of California. 53 00:03:28,680 --> 00:03:33,120 I'm told it's one of the best places in the world to see marine life. 54 00:03:34,480 --> 00:03:39,400 This is a body of water so rich in nutrients and life 55 00:03:39,400 --> 00:03:42,600 that the famous oceanographer Jacques Cousteau 56 00:03:42,600 --> 00:03:46,080 once described it as "the aquarium of the world". 57 00:03:52,720 --> 00:03:55,080 Sheltered from the Pacific Ocean, 58 00:03:55,080 --> 00:03:59,000 this almost inland sea is one of the great treasures of Mexico. 59 00:04:00,800 --> 00:04:03,720 Globally, our seas have been hammered by fishing, 60 00:04:03,720 --> 00:04:05,120 pollution and people. 61 00:04:05,120 --> 00:04:08,760 So can the Sea of Cortez still be the aquarium of the world? 62 00:04:08,760 --> 00:04:10,800 Can a sea still be a wilderness? 63 00:04:16,840 --> 00:04:19,400 There's a dolphin! Just here. 64 00:04:19,400 --> 00:04:21,000 And already, life! 65 00:04:22,360 --> 00:04:23,800 There's one just here! 66 00:04:25,320 --> 00:04:29,880 Almost a third of all the marine mammal species in the world 67 00:04:29,880 --> 00:04:32,200 can be found here in the Sea of Cortez. 68 00:04:33,520 --> 00:04:36,520 I'm travelling much of its length from north to south. 69 00:04:36,520 --> 00:04:40,200 This sea's also famous for its sharks, including bull sharks 70 00:04:40,200 --> 00:04:42,800 and critically endangered hammerheads. 71 00:04:42,800 --> 00:04:46,520 And scattered across the sea, there's life on its islands. 72 00:04:48,160 --> 00:04:50,960 So this is San Pedro Martir Island. 73 00:04:50,960 --> 00:04:52,400 It's uninhabited. 74 00:04:53,360 --> 00:04:56,360 It's a jagged chunk of volcanic rock 75 00:04:56,360 --> 00:04:58,520 thrusting up out of the deep blue sea. 76 00:05:02,280 --> 00:05:05,800 The island of San Pedro Martir is a wild place... 77 00:05:07,640 --> 00:05:10,640 ..at the heart of one of the richest areas of marine life 78 00:05:10,640 --> 00:05:12,120 in the whole Sea of Cortez. 79 00:05:15,000 --> 00:05:18,120 This is a globally important site for seabirds, 80 00:05:18,120 --> 00:05:20,560 and home to a huge colony of sea lions. 81 00:05:24,360 --> 00:05:27,680 So this is a slightly tricky island to land on. 82 00:05:29,320 --> 00:05:31,840 The locals don't get many human visitors. 83 00:05:34,200 --> 00:05:35,240 Right. 84 00:05:36,280 --> 00:05:37,800 So the plan... 85 00:05:38,760 --> 00:05:41,080 ..is, this is where I'm going to camp tonight. 86 00:05:42,840 --> 00:05:44,440 OK, Jose! 87 00:05:47,240 --> 00:05:48,440 Cheers, mate. 88 00:05:52,240 --> 00:05:55,400 What an astonishing place to be left. 89 00:05:57,160 --> 00:05:59,200 SEA LION BARKS 90 00:06:00,760 --> 00:06:02,840 Yeah, same to you. Jesus! 91 00:06:04,080 --> 00:06:08,640 It's thought more than 2,000 sea lions make this island home, 92 00:06:08,640 --> 00:06:11,000 and tomorrow I'm hoping to meet them properly. 93 00:06:12,080 --> 00:06:14,000 And then there's the birds. 94 00:06:14,000 --> 00:06:18,200 Historically, there's been so many of them here, and so much bird poo, 95 00:06:18,200 --> 00:06:22,720 that in the 1800s, tough Mexican miners had the grim job 96 00:06:22,720 --> 00:06:27,320 of scraping up tons of bird guano to sell as fertiliser for farmers. 97 00:06:28,400 --> 00:06:30,760 But none of the miners ever settled here. 98 00:06:35,000 --> 00:06:36,960 And I soon realise why. 99 00:06:39,760 --> 00:06:42,040 It's a little bit windy. 100 00:06:43,040 --> 00:06:46,720 The guidebook somehow forgot to mention the 50mph gales... 101 00:06:48,000 --> 00:06:51,080 ..leaving me desperately anchoring my tent with rocks. 102 00:06:52,520 --> 00:06:54,040 - BLEEP - hell! 103 00:07:06,480 --> 00:07:08,920 It's not just the wind blowing a gale. 104 00:07:08,920 --> 00:07:13,240 It's the fine dust blowing around everywhere in the air 105 00:07:13,240 --> 00:07:15,320 and settling on everything and in our... 106 00:07:16,480 --> 00:07:19,520 ..ears, and up my nose, in my mouth and eyes. 107 00:07:19,520 --> 00:07:25,560 And the dust is sort of ground-up bird poo that's blowing around. 108 00:07:32,080 --> 00:07:34,960 This is rapidly becoming one of the... 109 00:07:34,960 --> 00:07:39,200 ..less pleasant camping experiences of my life. 110 00:07:43,680 --> 00:07:45,880 HE GROANS 111 00:07:55,560 --> 00:07:57,560 Morning is glorious. 112 00:08:07,640 --> 00:08:10,920 A quick rinse to clean off the worst of the bird poo 113 00:08:10,920 --> 00:08:13,640 and I'm off to see who's responsible for the dust. 114 00:08:18,600 --> 00:08:22,040 This island is one of the single most important breeding sites 115 00:08:22,040 --> 00:08:24,400 in the world for a crucial seabird - 116 00:08:24,400 --> 00:08:26,720 the blue-footed booby. 117 00:08:26,720 --> 00:08:30,360 The blue colour of their feet comes from a pigment in the fish they eat. 118 00:08:30,360 --> 00:08:34,680 The bluer their feet, the better the hunter, of both sexes... 119 00:08:34,680 --> 00:08:37,120 ..and better the chances of finding a mate. 120 00:08:40,440 --> 00:08:41,720 Jose! 121 00:08:50,600 --> 00:08:51,760 You jumping in? 122 00:08:53,960 --> 00:08:56,600 I'm heading to the boat that'll take me on my journey 123 00:08:56,600 --> 00:08:58,200 down the Sea of Cortez. 124 00:09:00,000 --> 00:09:03,400 The M/V Storm is used for scientific research, 125 00:09:03,400 --> 00:09:05,680 taking biologists to study marine life, 126 00:09:05,680 --> 00:09:07,840 including the sea lions of this island. 127 00:09:07,840 --> 00:09:09,240 Hola. 128 00:09:09,240 --> 00:09:10,680 - Que tal? 129 00:09:12,400 --> 00:09:15,720 - You might be Ernesto. - I am Ernesto. Nice to meet you, Simon. 130 00:09:15,720 --> 00:09:17,680 - Hello, mate. - I've heard a lot about you. 131 00:09:17,680 --> 00:09:19,720 - Dive guide legend Ernesto Ruiz 132 00:09:19,720 --> 00:09:22,440 and marine biologist Isabelle Nelson Morales 133 00:09:22,440 --> 00:09:25,560 are my expert guides and companions for the next couple of weeks. 134 00:09:25,560 --> 00:09:28,240 Hiya. Isabelle? - Hi. Nice to meet you. - Simon. 135 00:09:28,240 --> 00:09:30,640 Very nice to see you too. - Welcome on board. - Thank you. 136 00:09:30,640 --> 00:09:32,880 Isabelle, can you do a tour? - Of course. 137 00:09:33,960 --> 00:09:39,280 So, first, in here... - All right. - ..we have the kitchen. - Yeah. 138 00:09:39,280 --> 00:09:42,640 - This is where we're going to have all our meals together. - OK. 139 00:09:42,640 --> 00:09:45,040 - Nice and cosy. - It is nice and cosy. Perfect. 140 00:09:45,040 --> 00:09:47,120 - Down here we have some beds. 141 00:09:47,120 --> 00:09:49,960 - All right. It's going to be tight. - It's going to be tight. 142 00:09:49,960 --> 00:09:53,360 - But we'll be OK. - We'll go from point A to point B. - OK. 143 00:09:54,600 --> 00:09:56,720 First, we're moving around the island 144 00:09:56,720 --> 00:09:58,480 to try and get closer to the sea lions 145 00:09:58,480 --> 00:10:00,320 that live in the Sea of Cortez. 146 00:10:00,320 --> 00:10:03,680 I want to see if they're still thriving in their underwater world. 147 00:10:03,680 --> 00:10:05,880 - We have a couple of species of sea lion - 148 00:10:05,880 --> 00:10:08,560 the California sea lion, which is more iconic to the Gulf, 149 00:10:08,560 --> 00:10:11,840 but we also have the Guadalupe fur seal 150 00:10:11,840 --> 00:10:14,120 that also we can find inside the Gulf. 151 00:10:15,640 --> 00:10:17,640 - On hundreds of dives, 152 00:10:17,640 --> 00:10:21,160 Ernesto and Isabelle have studied sea lions up close. 153 00:10:35,240 --> 00:10:37,640 This is the California sea lion. 154 00:10:37,640 --> 00:10:40,360 It's an acrobatic underwater master. 155 00:10:46,280 --> 00:10:48,880 I'm stunned by how many of them there are. 156 00:10:50,320 --> 00:10:54,080 They live, hunt and play in huge communities called rookeries. 157 00:10:54,080 --> 00:10:56,640 They hunt fish and squid cooperatively, 158 00:10:56,640 --> 00:10:58,640 like a pack of wolves. 159 00:10:58,640 --> 00:11:02,640 They're agile and adaptable, with a hugely varied diet. 160 00:11:02,640 --> 00:11:06,080 And sea lions, here at least, are still thriving. 161 00:11:10,440 --> 00:11:13,520 I have to be honest - being down beneath me, 162 00:11:13,520 --> 00:11:17,960 it makes coming up here feel a little bit empty and barren. 163 00:11:18,960 --> 00:11:20,840 Down beneath the waves here... 164 00:11:21,800 --> 00:11:26,120 ..there is an entire ecosystem of life and glory. 165 00:11:28,280 --> 00:11:30,080 - That was very amazing. 166 00:11:30,080 --> 00:11:33,200 I'm not used to seeing so many sea lions together. 167 00:11:33,200 --> 00:11:36,320 - Even you? - Yes. All of them, like, playing among them 168 00:11:36,320 --> 00:11:39,120 and also coming quite close to us. - Right. 169 00:11:39,120 --> 00:11:40,520 - That was a nice surprise. 170 00:11:46,040 --> 00:11:50,720 - The Sea of Cortez supports more than 30 species of marine mammals, 171 00:11:50,720 --> 00:11:55,240 300 species of birds and almost 1,000 species of fish, 172 00:11:55,240 --> 00:11:58,560 all thanks to some spectacular underwater geography. 173 00:11:59,960 --> 00:12:04,080 What makes the Sea of Cortez special for you and for... 174 00:12:04,080 --> 00:12:06,160 I suppose for marine life as well? 175 00:12:06,160 --> 00:12:09,800 - So, the way that the Gulf is composed, 176 00:12:09,800 --> 00:12:13,200 it's a mix of conditions that go from, like, 177 00:12:13,200 --> 00:12:17,160 really deep underwater basins and cliffs that fall hundreds of metres, 178 00:12:17,160 --> 00:12:22,680 and this allows for very rich water that has a lot of nutrients in it, 179 00:12:22,680 --> 00:12:25,360 very productive, to come all the way up to the surface. 180 00:12:25,360 --> 00:12:29,600 And this makes an amazing feeding ground for all types of animals 181 00:12:29,600 --> 00:12:32,400 and this reflects all the way up the food chain. 182 00:12:32,400 --> 00:12:34,360 - What are you hoping we might see? 183 00:12:34,360 --> 00:12:36,440 - I think that when we get in the water, 184 00:12:36,440 --> 00:12:39,120 we have really good chances to see some sharks. - Right. 185 00:12:39,120 --> 00:12:41,760 So we're not going to see them popping up to say hello 186 00:12:41,760 --> 00:12:44,120 the way dolphins and whales might? - No. 187 00:12:44,120 --> 00:12:46,440 - But if we're in the water, we might see sharks? 188 00:12:46,440 --> 00:12:49,520 - There's actually a huge variety of them that we can find here. 189 00:12:49,520 --> 00:12:51,160 - Ohhh! 190 00:12:51,160 --> 00:12:54,560 The little heart goes... beats slightly more now. 191 00:12:55,920 --> 00:12:57,880 Sharks get a bad rap, 192 00:12:57,880 --> 00:13:01,680 but they are a crucial element here and in many marine ecosystems. 193 00:13:03,680 --> 00:13:07,880 As apex predators, prowling lions, they control the numbers 194 00:13:07,880 --> 00:13:10,120 of the creatures beneath them in the food chain, 195 00:13:10,120 --> 00:13:12,320 keeping our seas and oceans in balance. 196 00:13:18,520 --> 00:13:23,000 Heart flutters aside, I'm really hoping we will see sharks. 197 00:13:23,000 --> 00:13:25,000 If they're still here in large numbers, 198 00:13:25,000 --> 00:13:28,840 that will help bolster the idea this sea is still a healthy wilderness. 199 00:13:30,240 --> 00:13:34,840 From here, our next stop is a remote outpost called Espiritu Santo. 200 00:13:34,840 --> 00:13:38,200 There, I'm hoping to meet local fishermen - shark experts. 201 00:13:39,280 --> 00:13:42,000 From there, it's south to a conservation area, 202 00:13:42,000 --> 00:13:45,760 where it's claimed some of the most powerful sharks have returned. 203 00:13:45,760 --> 00:13:50,520 And finally, where the sea meets the vast open blue of the Pacific Ocean, 204 00:13:50,520 --> 00:13:53,720 there's reports one of the rarest creatures in the marine world 205 00:13:53,720 --> 00:13:55,760 still gathers in huge shoals. 206 00:14:02,440 --> 00:14:06,040 The fishing outpost is 280 miles ahead of us, 207 00:14:06,040 --> 00:14:08,120 which means travelling day and night. 208 00:14:09,880 --> 00:14:13,120 It's a bit tight in here, but it is cosy. 209 00:14:13,120 --> 00:14:18,000 There's a gentle sway of the boat, which at the moment is fine. 210 00:14:18,000 --> 00:14:19,800 Actually, I'll tell you, anything is better than 211 00:14:19,800 --> 00:14:23,240 being blown to pieces on the side of a hill, 212 00:14:23,240 --> 00:14:28,120 with your tent falling apart and choking on bird poo dust. 213 00:14:28,120 --> 00:14:30,480 I'd take this 100 times over that. 214 00:14:37,600 --> 00:14:40,960 For two days and nights, we don't see a single other boat. 215 00:14:50,480 --> 00:14:53,200 Life on the Storm falls into a gentle rhythm. 216 00:14:57,560 --> 00:14:59,480 BELL RINGS 217 00:15:05,560 --> 00:15:08,720 I'm just in the middle of having some food. The call's come in - 218 00:15:08,720 --> 00:15:10,040 pilot whales! 219 00:15:12,640 --> 00:15:14,000 Look, just there! 220 00:15:32,160 --> 00:15:34,760 Our boat, the Storm, can't get too close 221 00:15:34,760 --> 00:15:37,600 to the beautiful fishing island of Espiritu Santo, 222 00:15:37,600 --> 00:15:39,720 so some of the locals come out to meet us. 223 00:15:41,760 --> 00:15:44,480 Here they are. - Hola. Buenos dias. 224 00:15:44,480 --> 00:15:47,720 - Mucho gusto! - Mucho gusto. 225 00:15:47,720 --> 00:15:49,600 - Simon. - Malael. 226 00:15:51,040 --> 00:15:53,120 - Hello, hello. - Hola. - Hola. Jorge. 227 00:15:53,120 --> 00:15:54,400 - Hola, Jorge. 228 00:15:54,400 --> 00:15:55,760 All right! 229 00:15:57,560 --> 00:15:59,280 - Be careful. OK. 230 00:16:02,040 --> 00:16:05,680 - Malael and Jorge are actually from the Mexican city of La Paz, 231 00:16:05,680 --> 00:16:07,160 a long journey from here. 232 00:16:09,480 --> 00:16:12,840 But they spend more than half their lives out here on this island, 233 00:16:12,840 --> 00:16:15,320 with a few others, in a small fishing camp. 234 00:16:22,920 --> 00:16:25,800 This is somebody's cabin. Is there somebody asleep here? 235 00:16:38,480 --> 00:16:41,600 I feel like we've invaded your private, sacred space. 236 00:16:43,280 --> 00:16:47,240 Can we just look at how carefully organised this is? 237 00:16:59,640 --> 00:17:02,840 Jorge's running a tight, clean kitchen, OK? 238 00:17:06,120 --> 00:17:08,800 Hang on, what's that on top of the building there? 239 00:17:09,960 --> 00:17:11,920 That's Starlink? - Si. 240 00:17:11,920 --> 00:17:15,080 - You've got your satellite internet here. - Yes. 241 00:17:15,080 --> 00:17:17,160 - Look at this face of happiness. Look! 242 00:17:17,160 --> 00:17:18,640 HE LAUGHS 243 00:17:18,640 --> 00:17:20,200 - Internet. - Yeah. 244 00:17:22,560 --> 00:17:23,760 Right. 245 00:17:26,960 --> 00:17:29,560 You're not sitting out there on the terrace any more 246 00:17:29,560 --> 00:17:31,080 chatting about the sea, are you? 247 00:17:31,080 --> 00:17:33,400 You're watching bloody Mexican Netflix. 248 00:17:33,400 --> 00:17:35,960 And you're watching the Premier League, I reckon! 249 00:17:39,280 --> 00:17:41,240 THEY LAUGH 250 00:17:41,240 --> 00:17:43,840 Out in the wild, but connected to the world, 251 00:17:43,840 --> 00:17:47,240 It's not a bad life. For better or worse, 252 00:17:47,240 --> 00:17:49,160 satellite internet's only increasing 253 00:17:49,160 --> 00:17:51,120 the appeal of living in a wilderness. 254 00:17:52,400 --> 00:17:55,560 So the town life is not for you? 255 00:17:55,560 --> 00:17:59,360 You prefer being out here in the wild, in the wilderness? 256 00:18:18,080 --> 00:18:21,360 Can you imagine your children doing your job? 257 00:18:30,160 --> 00:18:31,880 Harder in what way? 258 00:18:36,840 --> 00:18:41,760 Do you still love the job, or is it becoming something painful for you? 259 00:18:55,440 --> 00:18:57,600 This is absolutely stunning, 260 00:18:57,600 --> 00:18:59,680 but it is of course very disappointing 261 00:18:59,680 --> 00:19:01,760 to hear fishermen say... 262 00:19:03,320 --> 00:19:05,720 .."there's not as much life in the ocean 263 00:19:05,720 --> 00:19:09,240 "as there was when my dad and my grandfather fished this area." 264 00:19:10,680 --> 00:19:13,360 That's something I'm hearing all around the world, 265 00:19:13,360 --> 00:19:17,520 even in the wildest, remotest areas, like this. 266 00:19:17,520 --> 00:19:21,480 We as a species have had a colossal impact 267 00:19:21,480 --> 00:19:23,000 on our seas and oceans. 268 00:19:26,840 --> 00:19:29,920 Malael and Jorge are proud fishermen, 269 00:19:29,920 --> 00:19:33,560 but now they're also involved in a crucial scientific project 270 00:19:33,560 --> 00:19:36,960 to save what some call the most important fish in the sea - 271 00:19:36,960 --> 00:19:38,320 the shark. 272 00:19:40,880 --> 00:19:43,560 - Nice to meet you. Welcome. So happy to have you here. 273 00:19:43,560 --> 00:19:47,080 - Thank you very much indeed. Simon, and... - Darren. Dr Darren. 274 00:19:47,080 --> 00:19:49,560 - Darren. Dr Darren. - Nice to meet you. - Dr Darren? I like that. 275 00:19:49,560 --> 00:19:51,920 That's got a ring to it. - Yeah, it's got a nice ring to it. 276 00:19:51,920 --> 00:19:55,360 And I have a couple of students with me today from the local university. 277 00:19:55,360 --> 00:19:58,000 - Hello. Simon. Lovely to meet you. Thank you. 278 00:19:58,000 --> 00:20:00,240 What's your name? - Nice to meet you. Elis. - Elis. 279 00:20:00,240 --> 00:20:02,680 Hello. Hello. Simon. Nice to see you. 280 00:20:02,680 --> 00:20:05,760 Dr Darren Whitehead is a marine biologist. 281 00:20:05,760 --> 00:20:07,840 He's originally from Grimsby, 282 00:20:07,840 --> 00:20:12,080 but he now runs campaign group Shark Research Mexico. 283 00:20:12,080 --> 00:20:15,000 He's studying scalloped hammerhead sharks, 284 00:20:15,000 --> 00:20:18,160 some of the most critically endangered sharks on Earth. 285 00:20:18,160 --> 00:20:20,560 And he's working with the fishermen here. 286 00:20:30,480 --> 00:20:32,520 What are you here to do? 287 00:20:32,520 --> 00:20:37,000 - So we're here to satellite tag hammerhead sharks. - OK. 288 00:20:37,000 --> 00:20:38,360 - You know, the hammerhead sharks, 289 00:20:38,360 --> 00:20:42,240 at night-times they leave their protective areas and go to hunt. 290 00:20:42,240 --> 00:20:45,880 As the sun comes up, they come back to school for protection. 291 00:20:45,880 --> 00:20:47,920 So the best time to catch the hammerhead sharks, 292 00:20:47,920 --> 00:20:50,720 the scalloped hammerhead sharks, is sunrise. 293 00:20:52,240 --> 00:20:57,360 - Six o'clock? - I would say 4.00am would work best. 294 00:20:57,360 --> 00:20:58,640 - OK. 295 00:21:02,920 --> 00:21:05,560 I'm not what you'd call a morning person, 296 00:21:05,560 --> 00:21:08,400 but the chance of seeing amazing sharks close up 297 00:21:08,400 --> 00:21:10,560 should be enough to get anyone out of bed. 298 00:21:18,880 --> 00:21:20,720 ALARM RINGS 299 00:21:22,480 --> 00:21:24,320 Oh, goodness. 300 00:21:39,160 --> 00:21:41,960 So it's just after four o'clock in the morning, 301 00:21:41,960 --> 00:21:46,880 and we're heading out to try and catch and tag a shark, as you do. 302 00:21:50,360 --> 00:21:52,640 - Good morning. - Good morning to you. 303 00:21:52,640 --> 00:21:55,400 - Good morning to you. Welcome on board. - Cheers. 304 00:21:58,520 --> 00:22:00,560 We know that just a generation ago, 305 00:22:00,560 --> 00:22:04,360 scalloped hammerhead sharks were found here in huge numbers. 306 00:22:04,360 --> 00:22:07,640 Jorge and Malael used to catch them regularly. 307 00:22:07,640 --> 00:22:09,480 Now they're vanishingly rare. 308 00:22:09,480 --> 00:22:11,280 It's feared numbers have collapsed 309 00:22:11,280 --> 00:22:14,600 by more than 95% in some areas of the sea. 310 00:22:14,600 --> 00:22:17,080 But scientists need more data. 311 00:22:17,080 --> 00:22:18,800 - These are the satellite tags 312 00:22:18,800 --> 00:22:22,880 that are getting mounted on to the dorsal fin of the sharks. 313 00:22:22,880 --> 00:22:24,600 - Goodness me. 314 00:22:24,600 --> 00:22:27,520 - This is going to give us six to eight months of the shark's life. 315 00:22:27,520 --> 00:22:30,160 So this is a real-time GPS transmitter, 316 00:22:30,160 --> 00:22:32,480 so whenever the animal breaks the surface, 317 00:22:32,480 --> 00:22:35,000 it has a switch that turns the tag on, 318 00:22:35,000 --> 00:22:36,880 and actively looks for a GPS signal. 319 00:22:36,880 --> 00:22:40,640 - So that helps you to build up a proper picture of 320 00:22:40,640 --> 00:22:42,920 their behaviour and their range. - Yeah, a baseline. 321 00:22:42,920 --> 00:22:45,640 A baseline of information that gives us this knowledge 322 00:22:45,640 --> 00:22:47,080 we can give to governments, 323 00:22:47,080 --> 00:22:49,920 improve management of the species and conservation. 324 00:22:52,920 --> 00:22:55,320 - That's a beautiful sunrise. - This is always a good time. 325 00:22:55,320 --> 00:22:58,080 We call this the first bite, or the first strike. 326 00:22:58,080 --> 00:23:00,000 Sunrise is coming up, they're hungry, 327 00:23:00,000 --> 00:23:03,440 they're coming back to protection, maybe they didn't get to forage. 328 00:23:06,400 --> 00:23:09,040 - We have one! - THEY SPEAK SPANISH 329 00:23:09,040 --> 00:23:10,760 - He's got one. - Yeah. 330 00:23:12,320 --> 00:23:14,960 - Scalloped hammerhead sharks are so named 331 00:23:14,960 --> 00:23:16,960 for the notches on their heads. 332 00:23:16,960 --> 00:23:20,480 They can grow to more than eight feet long. 333 00:23:20,480 --> 00:23:24,520 For Darren's research, we're aiming for one younger and much smaller. 334 00:23:29,160 --> 00:23:31,200 Look at the size of you! 335 00:23:31,200 --> 00:23:34,560 Not what we were expecting. A huge red snapper. 336 00:23:34,560 --> 00:23:37,400 - You can see, he thought it was a shark by the size of the fish. 337 00:23:37,400 --> 00:23:39,680 A wonderful fish here. Look at those teeth. 338 00:23:41,200 --> 00:23:44,280 - That is stunning. - They're asking if they can keep it. 339 00:23:44,280 --> 00:23:47,960 - Right. And what's your response to that? - It's food. 340 00:23:47,960 --> 00:23:49,160 - Yeah. 341 00:23:49,160 --> 00:23:51,520 - Sustainable. It's caught by hand. 342 00:23:51,520 --> 00:23:54,600 - That is so incredibly beautiful. 343 00:23:58,600 --> 00:24:00,840 - It's a food source for them. - Yeah. 344 00:24:00,840 --> 00:24:03,720 - It would be kind of cruel to ask them to throw it back. 345 00:24:03,720 --> 00:24:05,600 OK, false alarm. 346 00:24:05,600 --> 00:24:08,760 - With the sun coming up, our chances are fading, 347 00:24:08,760 --> 00:24:10,680 but I'm crossing my fingers. 348 00:24:18,520 --> 00:24:20,440 There's a lot of action suddenly. 349 00:24:20,440 --> 00:24:22,840 - Strong, very strong. - Very Strong. 350 00:24:22,840 --> 00:24:24,440 Yeah. 351 00:24:30,560 --> 00:24:34,440 - So hopefully there is a hammerhead shark on the end of the line. 352 00:24:36,920 --> 00:24:38,520 They seem pretty confident. 353 00:24:38,520 --> 00:24:42,880 And if there is, it's going to come into the boat, hopefully, 354 00:24:42,880 --> 00:24:45,480 and lie here, hopefully. 355 00:24:48,680 --> 00:24:52,400 But, you know, this is an unpredictable situation. 356 00:24:53,680 --> 00:24:55,800 - Do you see it? - Yeah, shark. 357 00:24:55,800 --> 00:24:57,960 We've got a hammerhead on. - OK. 358 00:25:03,040 --> 00:25:04,560 Success! 359 00:25:06,000 --> 00:25:08,720 Hammerheads, like some other sharks, need to keep moving 360 00:25:08,720 --> 00:25:11,960 to keep water going through their gills, or they suffocate. 361 00:25:11,960 --> 00:25:13,440 They move or die. 362 00:25:14,480 --> 00:25:16,680 But a water hose can be life support. 363 00:25:18,400 --> 00:25:19,640 - So we have a beautiful, 364 00:25:19,640 --> 00:25:22,440 beautiful juvenile scallop hammerhead on board. 365 00:25:22,440 --> 00:25:24,840 You can actually see the water coming through the gills. 366 00:25:24,840 --> 00:25:27,520 So the shark is actually breathing, even though it's not swimming. 367 00:25:27,520 --> 00:25:30,080 - You're in a slight race now, aren't you? - Yeah, so we're just going to... 368 00:25:30,080 --> 00:25:32,160 To minimise the stress on the shark, what we want to do is work 369 00:25:32,160 --> 00:25:34,200 as fast and as smooth as possible. 370 00:25:34,200 --> 00:25:36,520 So we're going to make a couple of small... 371 00:25:41,720 --> 00:25:43,480 OK, so we're going to mount the tag. 372 00:25:45,760 --> 00:25:47,520 Can I have the clippers, please? 373 00:25:48,720 --> 00:25:51,360 We have a maximum of ten minutes with the shark 374 00:25:51,360 --> 00:25:55,360 and we are almost finished already, so we are Formula 1 speed right now. 375 00:25:55,360 --> 00:25:58,640 - Of course. - OK, so the tag is already on. Let's pass the tape measure. 376 00:25:58,640 --> 00:26:01,640 So, Simon, I would like you to help me measure the shark. - Yeah. 377 00:26:01,640 --> 00:26:06,040 - So we're going to place this over the side, like this, on to the head. 378 00:26:06,040 --> 00:26:07,640 Bati, can you measure? 379 00:26:07,640 --> 00:26:10,840 OK. So we're looking at the total length of the shark... 380 00:26:12,400 --> 00:26:15,920 ..is 154 centimetres. 381 00:26:15,920 --> 00:26:17,840 That's a beautiful shark. 382 00:26:17,840 --> 00:26:20,080 So these sharks are remarkable. 383 00:26:20,080 --> 00:26:22,560 The form of the hammerhead head is incredible. 384 00:26:22,560 --> 00:26:24,800 It's evolved for specific reasons - 385 00:26:24,800 --> 00:26:28,520 one, to locate food which is hidden in the seabed. 386 00:26:28,520 --> 00:26:30,680 It's got this electromagnetic sensor in the head, 387 00:26:30,680 --> 00:26:32,400 which is phenomenal and remarkable. 388 00:26:32,400 --> 00:26:34,320 It's called the ampulla of Lorenzini, 389 00:26:34,320 --> 00:26:36,200 and it runs all over the head of the animal 390 00:26:36,200 --> 00:26:38,240 and that actually helps it find prey 391 00:26:38,240 --> 00:26:41,040 and just understand the environment that it lives in. 392 00:26:41,040 --> 00:26:43,240 So, last thing we're going to do, 393 00:26:43,240 --> 00:26:45,680 I'm going to take a small genetic sample of the shark. 394 00:26:45,680 --> 00:26:49,200 And we can use this for genetic population and to understand that. 395 00:26:49,200 --> 00:26:51,400 Thank you so much. 396 00:26:51,400 --> 00:26:52,720 - Poor thing. - OK. 397 00:26:53,960 --> 00:26:55,320 We are set to release. 398 00:26:55,320 --> 00:26:57,600 Let's get it back in the water. - Absolutely. 399 00:26:59,200 --> 00:27:02,360 These rare creatures are at risk of extinction. 400 00:27:02,360 --> 00:27:05,360 Dr Darren's research can help to protect them, 401 00:27:05,360 --> 00:27:08,040 for example identifying no-fishing zones. 402 00:27:09,280 --> 00:27:11,800 The waters around Espiritu Santo Island 403 00:27:11,800 --> 00:27:14,200 have now been declared a protected area, 404 00:27:14,200 --> 00:27:16,960 so there is hope their numbers can recover here. 405 00:27:18,680 --> 00:27:20,760 - Run free and wild, hammer! 406 00:27:22,000 --> 00:27:24,600 - Well done. - Good job, team. 407 00:27:24,600 --> 00:27:29,040 - That was a very impressive bit of science and conservation there. 408 00:27:29,040 --> 00:27:31,920 - Thank you. You're welcome. That's our job. - It really was. 409 00:27:31,920 --> 00:27:34,600 Do you have different emotions 410 00:27:34,600 --> 00:27:38,360 when you're bringing a shark in and then releasing it? 411 00:28:04,360 --> 00:28:06,880 I said goodbye to Malael and Jorge, 412 00:28:06,880 --> 00:28:10,280 and now, with Dr Darren, I'm sailing further along the coast. 413 00:28:18,320 --> 00:28:23,480 Since the 1950s, industrial fishing has transformed the Sea of Cortez. 414 00:28:24,760 --> 00:28:27,360 Each year, large fishing vessels scoop up 415 00:28:27,360 --> 00:28:31,200 hundreds of thousands of tonnes of small fish with huge nets - 416 00:28:31,200 --> 00:28:35,160 fish that once fed dolphins, sharks, seabirds and whales. 417 00:28:36,360 --> 00:28:39,800 Much of this catch is ground up to feed farmed fish, 418 00:28:39,800 --> 00:28:43,040 including some of the salmon sold in supermarkets. 419 00:28:50,720 --> 00:28:54,600 There's also more than 20,000 local or artisanal fishermen 420 00:28:54,600 --> 00:28:58,240 in the Sea of Cortez, and they also have a huge impact, 421 00:28:58,240 --> 00:29:01,240 especially on sharks, including hammerheads. 422 00:29:02,720 --> 00:29:04,760 Where are we now, Darren? What's this place called? 423 00:29:04,760 --> 00:29:06,240 - So this is called the Bay of Death. 424 00:29:06,240 --> 00:29:08,520 It's a very important bay in the area. 425 00:29:08,520 --> 00:29:11,560 Popular with... - Genuinely? - Genuinely the Bay of Death. 426 00:29:11,560 --> 00:29:13,840 The pirates would bring their sick crew 427 00:29:13,840 --> 00:29:17,320 and just dump them here and let them die, so Bay of Death. 428 00:29:17,320 --> 00:29:19,440 But it's used by a lot of artisanal fishermen, 429 00:29:19,440 --> 00:29:21,880 and this is the reason we're here today. - OK. 430 00:29:21,880 --> 00:29:23,720 - OK, let's go for it. 431 00:29:23,720 --> 00:29:26,360 - Darren's lived in Mexico for a decade. 432 00:29:26,360 --> 00:29:28,880 As a conservationist, he's hands-on. 433 00:29:28,880 --> 00:29:32,240 He's worked hard to build relationships all along the coast, 434 00:29:32,240 --> 00:29:35,240 even with the fishermen who hunt his beloved sharks. 435 00:29:35,240 --> 00:29:37,080 - This is... Mi companero. 436 00:29:37,080 --> 00:29:38,840 Su nombre es Simon. 437 00:29:38,840 --> 00:29:40,760 - Hola. - Inglaterra. - Simon. 438 00:29:40,760 --> 00:29:43,160 - Mi companero. - Mucho gusto. - Mucho gusto. 439 00:29:46,320 --> 00:29:47,520 - OK. 440 00:29:54,280 --> 00:29:55,720 - Oh, my. 441 00:29:59,080 --> 00:30:01,120 - So this is a scalloped hammerhead. 442 00:30:01,120 --> 00:30:03,840 As you can see, one of the ones that we tagged, very similar. 443 00:30:03,840 --> 00:30:06,680 And this is a silky shark. 444 00:30:06,680 --> 00:30:07,800 - Right. 445 00:30:10,240 --> 00:30:12,120 We're seeing here pulled out dead 446 00:30:12,120 --> 00:30:14,840 hammerhead sharks that you've been... 447 00:30:14,840 --> 00:30:18,080 You're trying to save as well. - Absolutely. 448 00:30:18,080 --> 00:30:20,840 And sometimes we get sharks that we've actually tagged 449 00:30:20,840 --> 00:30:23,000 and the fishermen find the tags. - Right. 450 00:30:24,280 --> 00:30:27,440 It's hard to overstate the importance of sharks. 451 00:30:27,440 --> 00:30:30,400 They hunt large fish just below them in the food chain, 452 00:30:30,400 --> 00:30:32,360 effectively managing their numbers. 453 00:30:32,360 --> 00:30:35,080 Without sharks, their populations can explode 454 00:30:35,080 --> 00:30:37,520 and put huge pressure on small fish. 455 00:30:37,520 --> 00:30:41,080 So sharks create balance. They're critical. 456 00:30:41,080 --> 00:30:43,160 How do you feel seeing this? 457 00:30:43,160 --> 00:30:46,120 - I mean, it's an emotional experience. 458 00:30:46,120 --> 00:30:48,360 We care so much for these animals. 459 00:30:48,360 --> 00:30:51,160 And the fishermen, they don't do it out of hate. 460 00:30:51,160 --> 00:30:53,040 - Yeah. - They don't have alternatives. 461 00:30:54,480 --> 00:30:56,240 Grande. - Si. 462 00:30:57,440 --> 00:30:59,480 - So we have another... - Is that another silky shark? 463 00:30:59,480 --> 00:31:01,040 - This is another silky female. 464 00:31:01,040 --> 00:31:02,840 We can take genetic samples, 465 00:31:02,840 --> 00:31:06,240 blood samples, we can look at the composition of this population. 466 00:31:06,240 --> 00:31:08,840 - What? You mean after the fishermen have caught them? 467 00:31:08,840 --> 00:31:09,960 They'll let you do that? 468 00:31:09,960 --> 00:31:11,680 - This is the relationship we have right now. I mean, 469 00:31:11,680 --> 00:31:13,360 we have to work hand in hand. 470 00:31:13,360 --> 00:31:14,760 Before, it was a fight. 471 00:31:14,760 --> 00:31:17,960 You know, "You're killing sharks, you're destroying our oceans.' 472 00:31:17,960 --> 00:31:21,520 But they are just ocean users, just like us, the shark fishermen, 473 00:31:21,520 --> 00:31:24,480 and we need to respect that - their traditions, their cultures. 474 00:31:25,520 --> 00:31:28,480 - There's also not much alternative work here. 475 00:31:28,480 --> 00:31:32,440 Many local fishermen do still make a living selling shark meat. 476 00:31:32,440 --> 00:31:35,520 It's seen as a cheap source of protein. 477 00:31:35,520 --> 00:31:37,240 But at what cost to the sea? 478 00:31:38,880 --> 00:31:40,560 How was today's catch? 479 00:31:40,560 --> 00:31:42,960 Is this what you would normally be expecting to bring in? 480 00:31:49,840 --> 00:31:51,240 Why do you think that is? 481 00:31:57,560 --> 00:31:59,160 How do you feel about that? 482 00:31:59,160 --> 00:32:02,160 I mean, is it making it harder to be a shark fisherman? 483 00:32:02,160 --> 00:32:04,600 Have you thought about stopping shark fishing? 484 00:32:31,160 --> 00:32:32,600 - Hold it right up to the nose there 485 00:32:32,600 --> 00:32:35,400 and just give us a shout what measurement that is. 486 00:32:35,400 --> 00:32:38,800 - 187. - 187, so close to two metres. 487 00:32:38,800 --> 00:32:41,000 It's like a human, like a person. 488 00:32:41,000 --> 00:32:42,400 - Yeah, that's true. 489 00:32:44,280 --> 00:32:49,440 Some of these fins and tails will end up in China, in shark fin soup, 490 00:32:49,440 --> 00:32:52,520 often consumed to display wealth and status. 491 00:32:53,640 --> 00:32:57,400 To create the soup, millions of sharks are killed every year. 492 00:32:57,400 --> 00:33:01,640 It seems no corner of the globe is safe from the ravages of this trade, 493 00:33:01,640 --> 00:33:03,560 even the Sea of Cortez. 494 00:33:03,560 --> 00:33:05,800 I'm finding this particularly difficult. 495 00:33:05,800 --> 00:33:09,760 I think I just know how critical these creatures are. 496 00:33:09,760 --> 00:33:12,280 That they're not just life. 497 00:33:12,280 --> 00:33:16,480 They are balancers of an entire ecosystem. 498 00:33:20,760 --> 00:33:24,440 And what's the law on this in Mexico? 499 00:33:24,440 --> 00:33:26,440 - What they're doing is completely legal. 500 00:33:26,440 --> 00:33:28,840 There's nothing illegal that's happening right now. 501 00:33:28,840 --> 00:33:31,480 It's a huge problem we have in Mexican fisheries. 502 00:33:31,480 --> 00:33:34,880 They need to be more controlled, more understanding of this. 503 00:33:34,880 --> 00:33:37,600 These are larger animals that should not be taken from our oceans. 504 00:33:37,600 --> 00:33:40,480 This is devastating our ecosystems. 505 00:33:40,480 --> 00:33:42,640 Most of the sharks that are critically endangered 506 00:33:42,640 --> 00:33:46,080 in other countries are legally fishable in Mexican waters. 507 00:33:46,080 --> 00:33:47,640 - And how do you feel about that, 508 00:33:47,640 --> 00:33:51,680 as a marine biologist working here? - It's a tragedy. It's a tragedy. 509 00:33:51,680 --> 00:33:56,400 - The Mexican government has tightened laws on shark fishing, 510 00:33:56,400 --> 00:33:59,560 including restricting it at some times of the year. 511 00:33:59,560 --> 00:34:03,560 But to protect this wilderness, Darren wants tougher action... 512 00:34:03,560 --> 00:34:04,760 - Mucho gracias. 513 00:34:04,760 --> 00:34:07,920 - ..especially against the big industrial trawlers. 514 00:34:07,920 --> 00:34:10,440 He's hoping his research will bolster his case. 515 00:34:12,800 --> 00:34:14,680 I've said a fond farewell to Darren, 516 00:34:14,680 --> 00:34:17,960 and I'm heading back to the M/V Storm. 517 00:34:17,960 --> 00:34:22,560 - Hi. Hello. Welcome back. - Thank you. 518 00:34:28,680 --> 00:34:30,320 Isabelle! 519 00:34:40,040 --> 00:34:43,720 We're sailing south towards a conservation area 520 00:34:43,720 --> 00:34:46,080 that's been a remarkable success, 521 00:34:46,080 --> 00:34:48,720 including with another species of shark 522 00:34:48,720 --> 00:34:52,720 much bigger and significantly more dangerous. 523 00:34:52,720 --> 00:34:55,200 We're heading to a place called Cabo Pulmo. 524 00:35:01,960 --> 00:35:04,840 A couple of hours pottering along in the boat, 525 00:35:04,840 --> 00:35:08,520 and suddenly there's a reminder of glorious life beneath us. 526 00:35:09,760 --> 00:35:11,920 We saw something moving in the water. 527 00:35:11,920 --> 00:35:13,400 Rob's put the drone up. 528 00:35:15,360 --> 00:35:16,960 - Woo! 529 00:35:16,960 --> 00:35:20,720 Big jump. - And my, oh, my, it's quite a sight. 530 00:35:26,560 --> 00:35:31,480 It's a huge shoal of mobula rays, the flying superstars of the ocean. 531 00:35:32,720 --> 00:35:34,920 - There's hundreds of rays 532 00:35:34,920 --> 00:35:37,880 swimming together and jumping out of the water. 533 00:35:37,880 --> 00:35:39,760 Going again. Whee! 534 00:35:41,680 --> 00:35:43,800 Hey! 535 00:35:45,400 --> 00:35:47,680 Three metres. - That was beautiful. 536 00:35:47,680 --> 00:35:50,440 - I think if I go any lower, it might hit the drone. 537 00:35:54,640 --> 00:35:57,080 - And that, that is special. 538 00:36:00,000 --> 00:36:04,000 These incredible fish can gather in shoals of up to 10,000. 539 00:36:05,120 --> 00:36:07,480 It's thought the slapping noise of their leaps 540 00:36:07,480 --> 00:36:10,000 might co-ordinate the shoal... 541 00:36:11,840 --> 00:36:13,720 ..and keep the whole show on the road. 542 00:36:22,360 --> 00:36:27,200 Onwards, to a unique area of coral reef in the Sea of Cortez. 543 00:36:27,200 --> 00:36:29,880 The health of it, the success of it, 544 00:36:29,880 --> 00:36:33,200 is a crucial marker of the health of the entire wilderness. 545 00:36:34,400 --> 00:36:36,080 Time to get the scuba gear ready. 546 00:36:37,800 --> 00:36:41,880 - We burn it a little bit so that your mask never fogs up again. 547 00:36:41,880 --> 00:36:44,800 - You do that before every dive, or...? 548 00:36:44,800 --> 00:36:46,360 - Usually when the mask is new. 549 00:36:46,360 --> 00:36:49,000 It's just until that film disappears. 550 00:36:49,000 --> 00:36:51,720 - Don't you just spit in your mask like everybody else? 551 00:36:51,720 --> 00:36:53,000 SHE LAUGHS 552 00:36:53,000 --> 00:36:54,880 It is very clear, I grant you. 553 00:36:56,160 --> 00:36:58,480 All right, where are we going to use this next? 554 00:36:58,480 --> 00:37:02,720 - So next we're going to Cabo Pulmo. And it's one of the most 555 00:37:02,720 --> 00:37:06,560 successful stories of ocean conservation, 556 00:37:06,560 --> 00:37:09,680 because it comes from a community approach 557 00:37:09,680 --> 00:37:12,480 rather than something that was enforced on them. 558 00:37:12,480 --> 00:37:14,880 They realised they just weren't getting 559 00:37:14,880 --> 00:37:17,120 as much fish as before, 560 00:37:17,120 --> 00:37:22,200 so they decided to protect the whole thing, stop fishing completely. 561 00:37:22,200 --> 00:37:24,960 Now it's a very thriving reef ecosystem 562 00:37:24,960 --> 00:37:28,960 that is hardly found anywhere else in the Sea of Cortez. 563 00:37:28,960 --> 00:37:32,600 - It's quite a success story. - Yes, completely. 564 00:37:32,600 --> 00:37:35,480 So we're going to dock when we get to Cabo Pulmo, 565 00:37:35,480 --> 00:37:39,040 which I think is in about a couple of hours still. - Right. 566 00:37:39,040 --> 00:37:41,560 - We dock there, sleep there on the boat, 567 00:37:41,560 --> 00:37:45,800 and then tomorrow, early, we go for our first dives. - OK. 568 00:37:55,800 --> 00:38:00,880 Time to get into the Sea of Cortez, see what's down there. 569 00:38:02,920 --> 00:38:07,880 30 years ago, this entire area had been devastated by overfishing. 570 00:38:09,520 --> 00:38:12,080 It was described as an underwater wasteland. 571 00:38:15,120 --> 00:38:18,560 Now I want to see what it looks like after a fishing ban. 572 00:38:21,360 --> 00:38:23,360 It's been transformed. 573 00:38:26,440 --> 00:38:29,920 Mexican goatfish, guinea fowl puffers, 574 00:38:29,920 --> 00:38:34,200 grunt snappers, rainbow runners and fearsome-looking Moray eels. 575 00:38:38,920 --> 00:38:40,520 The speed of the reef's recovery 576 00:38:40,520 --> 00:38:43,400 has astounded scientists and conservationists. 577 00:38:47,560 --> 00:38:49,760 These fish, bigeye jacks, 578 00:38:49,760 --> 00:38:54,120 are found throughout the tropics, and they love healthy coral reef. 579 00:38:54,120 --> 00:38:58,720 Now they're back in shoals of thousands, as nature intended. 580 00:39:07,240 --> 00:39:10,400 This entire ecosystem has been restored. 581 00:39:17,920 --> 00:39:21,400 Oh, my good Lord! That was astonishing. 582 00:39:23,560 --> 00:39:27,280 I absolutely loved that. That was a very special dive. 583 00:39:27,280 --> 00:39:30,200 It's really quite hard to imagine 584 00:39:30,200 --> 00:39:36,080 just how recently this was a damaged, broken ecosystem. 585 00:39:36,080 --> 00:39:40,800 And then, by protecting it, by stopping fishing in this area, 586 00:39:40,800 --> 00:39:43,800 within such a short time, within ten years, 587 00:39:43,800 --> 00:39:46,600 the marine biomass in this area 588 00:39:46,600 --> 00:39:50,880 has increased by more than 460%. 589 00:39:50,880 --> 00:39:56,600 That's a bigger increase than in any other marine reserve on the planet. 590 00:40:05,600 --> 00:40:07,800 What's happened here at Cabo Pulmo 591 00:40:07,800 --> 00:40:10,960 has become something of a beacon for global conservation. 592 00:40:12,640 --> 00:40:17,880 In the 1980s and 1990s, fish life here was disappearing. 593 00:40:17,880 --> 00:40:21,920 Local fishermen realised they and their families had no future, 594 00:40:21,920 --> 00:40:25,160 so they decided to start protecting the area. 595 00:40:25,160 --> 00:40:27,440 It was the locals who made it happen. 596 00:40:27,440 --> 00:40:31,840 They turned to tourism and to conservation to make a living. 597 00:40:31,840 --> 00:40:34,240 I'm meeting Mario Castro, 598 00:40:34,240 --> 00:40:38,240 whose family has been a driving force behind the whole project. 599 00:40:38,240 --> 00:40:42,400 I think what you've achieved is... is not just incredible, 600 00:40:42,400 --> 00:40:45,680 it's almost unique. 601 00:40:45,680 --> 00:40:50,000 There's very few examples elsewhere in the world, 602 00:40:50,000 --> 00:40:54,760 and none of them have been quite as successful as you have here. 603 00:41:40,560 --> 00:41:42,200 I've just been in the water here, 604 00:41:42,200 --> 00:41:48,360 and I saw an enormous shoal of bigeye jacks, 605 00:41:48,360 --> 00:41:51,400 the size of a five-storey building. 606 00:41:51,400 --> 00:41:54,520 Is there a creature that you're really pleased 607 00:41:54,520 --> 00:41:59,240 has come back in large numbers into the protected area? 608 00:42:09,160 --> 00:42:11,440 Aren't they quite dangerous? 609 00:42:11,440 --> 00:42:14,640 SIMON GASPS, MARIO LAUGHS 610 00:42:14,640 --> 00:42:17,160 No! Come on! 611 00:42:17,160 --> 00:42:19,360 I know you didn't lose your leg to a shark. 612 00:42:19,360 --> 00:42:20,800 You shocker! MARIO LAUGHS 613 00:42:20,800 --> 00:42:23,960 This is how much Mario loves sharks. 614 00:42:23,960 --> 00:42:27,280 Look. - Yeah. - He's got a shark on his leg. 615 00:42:27,280 --> 00:42:28,400 MARIO CHUCKLES 616 00:42:36,760 --> 00:42:39,320 Bull sharks have been ruthlessly targeted 617 00:42:39,320 --> 00:42:41,360 for the trade in shark fins. 618 00:42:41,360 --> 00:42:44,440 Mario says they've returned to this area, 619 00:42:44,440 --> 00:42:47,680 which would be a major win for conservation. 620 00:42:47,680 --> 00:42:49,480 There's only one way to be sure. 621 00:42:51,480 --> 00:42:53,360 Bull sharks can be aggressive. 622 00:42:53,360 --> 00:42:55,680 Along with the great white and the tiger shark, 623 00:42:55,680 --> 00:42:59,080 they're responsible for the most fatal attacks on humans, 624 00:42:59,080 --> 00:43:02,480 especially in shallow coastal waters like these. 625 00:43:02,480 --> 00:43:03,880 It's a bit nerve-racking for me. 626 00:43:03,880 --> 00:43:05,680 - Huh? - For me, this is a bit nerve-racking. 627 00:43:05,680 --> 00:43:09,600 - OK. No worries. That's why we're here for you. - Yeah. 628 00:43:09,600 --> 00:43:12,800 - Diving with sharks is all about attitude. If you are like a prey, 629 00:43:12,800 --> 00:43:15,240 they're going to treat you as a prey. 630 00:43:15,240 --> 00:43:17,640 But if you are with confidence 631 00:43:17,640 --> 00:43:20,840 in front of them, you have no problem. 632 00:43:20,840 --> 00:43:22,960 - Stop panicking, Simon! 633 00:43:22,960 --> 00:43:26,240 - Don't worry, I'm going to join you. - You're there. You guys are there. 634 00:43:26,240 --> 00:43:27,880 I trust you guys. 635 00:43:35,680 --> 00:43:37,800 This is probably the most nerve-racking 636 00:43:37,800 --> 00:43:39,080 I've felt before a dive. 637 00:43:41,600 --> 00:43:43,480 If they're down beneath us now... 638 00:43:44,800 --> 00:43:47,680 My God, we're going to drop into their world. 639 00:43:49,520 --> 00:43:52,440 Yeah? OK. 640 00:43:52,440 --> 00:43:55,000 - I can see the sharks from here. Yeah, yeah. 641 00:43:55,000 --> 00:43:57,920 - You can see sharks from there? - Captain happy? 642 00:43:57,920 --> 00:43:59,280 - Jesus. 643 00:43:59,280 --> 00:44:02,360 - OK. Ready? Three, two, one, go. 644 00:44:05,560 --> 00:44:08,240 - All too quickly, we're dropping down. 645 00:44:15,840 --> 00:44:17,200 And there they are! 646 00:44:30,640 --> 00:44:33,880 Up to three metres or 10 feet long, 647 00:44:33,880 --> 00:44:37,640 bull sharks can weigh in at more than 300 kilos. 648 00:44:55,960 --> 00:44:59,280 Violent ambush predators, they're opportunists 649 00:44:59,280 --> 00:45:01,400 who will take almost anything that's edible. 650 00:45:04,720 --> 00:45:09,360 But right now, tiny fish are taking the parasites off their skin. 651 00:45:09,360 --> 00:45:12,800 They're being cleaned, and they're fairly relaxed. 652 00:45:18,160 --> 00:45:22,480 This creature is right at the top of the food chain in the Sea of Cortez. 653 00:45:22,480 --> 00:45:24,760 Powerful and magnificent. 654 00:45:55,320 --> 00:45:56,600 Oh, my good Lord! 655 00:45:59,320 --> 00:46:02,640 HE LAUGHS The apex predators are back! 656 00:46:02,640 --> 00:46:08,040 That is a sure sign of a healthy, functioning ecosystem. 657 00:46:17,240 --> 00:46:20,400 We weigh anchor on the M/V Storm. 658 00:46:20,400 --> 00:46:24,600 Cabo Pulmo is proof conservation can work, 659 00:46:24,600 --> 00:46:26,640 especially when it's locals driving it. 660 00:46:28,600 --> 00:46:30,760 Perhaps the Sea of Cortez is, 661 00:46:30,760 --> 00:46:34,360 at least in some places, still the aquarium of the world. 662 00:46:40,640 --> 00:46:42,360 Yet I'm still worried about the fate 663 00:46:42,360 --> 00:46:45,800 and health of hammerhead sharks like the one we tagged. 664 00:46:53,920 --> 00:46:57,840 So my final destination is a place called Gordo Banks, 665 00:46:57,840 --> 00:47:01,640 where the Sea of Cortez meets the Pacific Ocean. 666 00:47:01,640 --> 00:47:05,240 There used to be reports, almost legends, of shoals 667 00:47:05,240 --> 00:47:10,080 of more than 1,000 hammerhead sharks around Gordo Banks. 668 00:47:10,080 --> 00:47:13,840 But now scalloped hammerhead sharks are critically endangered. 669 00:47:14,760 --> 00:47:17,720 Have they still survived at Gordo Banks? 670 00:47:17,720 --> 00:47:19,840 I want to see if they're still here. 671 00:47:19,840 --> 00:47:23,280 And that means diving deeper than I've ever been before. 672 00:47:23,280 --> 00:47:27,080 - So today, we're doing an ocean blue dive, 673 00:47:27,080 --> 00:47:28,640 like, right in the blue. 674 00:47:28,640 --> 00:47:31,240 - What we've done before, and what I've done before, 675 00:47:31,240 --> 00:47:34,040 I can usually see the bottom, 676 00:47:34,040 --> 00:47:37,880 but you're talking about...nothing. 677 00:47:37,880 --> 00:47:40,560 - Open ocean, open ocean. - I'm looking forward to it. 678 00:47:40,560 --> 00:47:44,160 I think it's important to push ourselves just a little bit. 679 00:47:44,160 --> 00:47:49,800 This is a part of planet Earth that I haven't visited before, 680 00:47:49,800 --> 00:47:52,080 the deeper blue sea. 681 00:47:52,080 --> 00:47:54,840 So I'm excited to be doing this with you, mate. 682 00:47:54,840 --> 00:47:58,120 - OK. My pleasure, my pleasure. - SIMON LAUGHS 683 00:47:58,120 --> 00:48:02,920 Diving does involve some risk, especially in the deep. 684 00:48:02,920 --> 00:48:05,360 It's thought 20 times more people die each year 685 00:48:05,360 --> 00:48:08,800 in diving accidents than are killed by sharks. 686 00:48:08,800 --> 00:48:11,840 Deeper diving increases the risk of running out of air, 687 00:48:11,840 --> 00:48:15,400 and of deadly decompression sickness - the bends. 688 00:48:17,440 --> 00:48:21,640 This is a more difficult dive than I'm used to. 689 00:48:21,640 --> 00:48:25,520 It's a slightly more difficult dive than I'm entirely comfortable with, 690 00:48:25,520 --> 00:48:30,760 to be honest. The main protection against anything bad happening 691 00:48:30,760 --> 00:48:32,960 is this. 692 00:48:32,960 --> 00:48:34,400 CHUCKLES: - Hello. 693 00:48:34,400 --> 00:48:37,640 - Go with somebody who knows what they're doing. 694 00:48:39,000 --> 00:48:40,400 - Go... 695 00:48:45,000 --> 00:48:48,520 - One, two, three, go! 696 00:48:51,800 --> 00:48:56,080 - On most scuba dives, I've been down to no more than 15 metres. 697 00:48:58,160 --> 00:49:02,080 If hammerhead sharks are here, they'll be down deeper. 698 00:49:02,080 --> 00:49:05,640 30m, 40m, 50m and lower. 699 00:49:07,320 --> 00:49:09,720 Here, I can't see the bottom. 700 00:49:09,720 --> 00:49:14,320 The bank drops away below to depths of hundreds of metres. 701 00:49:14,320 --> 00:49:17,200 It's dizzying, vertigo-inducing. 702 00:49:21,360 --> 00:49:24,840 As we begin our descent, we pass through shoals 703 00:49:24,840 --> 00:49:27,840 of trevallies, mid-level predator fish. 704 00:49:31,080 --> 00:49:34,520 Diving is all about buoyancy. Release air from your 705 00:49:34,520 --> 00:49:37,160 buoyancy jacket and you go down, 706 00:49:37,160 --> 00:49:39,880 pump it back in from the tank, and you go up. 707 00:49:41,120 --> 00:49:44,520 Go down too quickly and you risk narcosis, 708 00:49:44,520 --> 00:49:47,000 which causes confusion, disorientation. 709 00:49:48,920 --> 00:49:52,360 The deeper I go, the quicker I use up the air in my tank, 710 00:49:52,360 --> 00:49:54,360 and the greater the risk of running out. 711 00:50:01,480 --> 00:50:05,520 But with no visual reference points, I can't really tell how deep I am. 712 00:50:08,840 --> 00:50:12,080 BREATHING 713 00:50:12,080 --> 00:50:14,120 Ernesto calls me back up. 714 00:50:18,200 --> 00:50:20,480 I should be constantly checking my depth 715 00:50:20,480 --> 00:50:22,680 on the dive computer on my wrist. 716 00:50:29,440 --> 00:50:34,600 For me, for us, this is an eerie, alien place. 717 00:50:34,600 --> 00:50:38,760 But for locals, this is home - a playground, even. 718 00:50:57,000 --> 00:51:01,120 Finally, we're at 30m down - 100 feet - 719 00:51:01,120 --> 00:51:03,720 and we're into the realm of the hammerheads. 720 00:51:29,760 --> 00:51:34,520 Out of the blue drifts a beautiful, elegant silky shark, 721 00:51:34,520 --> 00:51:38,040 named for its smooth, streamlined skin. 722 00:51:38,040 --> 00:51:41,760 They prey on the mid-sized fish I saw higher up, 723 00:51:41,760 --> 00:51:44,760 like the trevallies, jacks, tuna. 724 00:51:44,760 --> 00:51:46,800 By keeping the number of those fish down, 725 00:51:46,800 --> 00:51:49,960 they help maintain the populations of smaller fish 726 00:51:49,960 --> 00:51:52,400 like sardines and anchovies. 727 00:51:52,400 --> 00:51:54,000 It's all connected. 728 00:51:57,000 --> 00:52:00,160 I'm waiting. I'm hoping for hammerheads, 729 00:52:00,160 --> 00:52:03,080 but at this depth, I'm consuming air 730 00:52:03,080 --> 00:52:06,080 four times as fast as at the surface. 731 00:52:06,080 --> 00:52:08,600 I've got a maximum of ten minutes down here, 732 00:52:08,600 --> 00:52:10,840 and then things start to get tricky. 733 00:52:18,200 --> 00:52:19,520 No hammerheads. 734 00:52:21,200 --> 00:52:26,600 I have to leave time to get back to the surface gradually. 735 00:52:26,600 --> 00:52:30,200 Go up too fast and I risk decompression sickness - 736 00:52:30,200 --> 00:52:32,920 the bends - which can be fatal. 737 00:52:40,040 --> 00:52:42,840 We've been underwater for less than an hour, 738 00:52:42,840 --> 00:52:46,120 but we've drifted two miles in the current. 739 00:52:48,720 --> 00:52:51,280 Luckily, the dive boat captain finds us. 740 00:53:00,360 --> 00:53:04,080 No hammerheads, which is a huge disappointment, 741 00:53:04,080 --> 00:53:06,600 but perhaps I can have another search. 742 00:53:09,080 --> 00:53:12,480 So, no luck. 743 00:53:12,480 --> 00:53:13,960 But we'll try again. 744 00:53:24,800 --> 00:53:27,880 Early next morning, we're hoping for more luck. 745 00:53:32,000 --> 00:53:33,520 So we've seen dolphins. 746 00:53:33,520 --> 00:53:35,840 Now if we can see sharks... 747 00:53:41,280 --> 00:53:44,080 - One, two, three, go! 748 00:53:56,560 --> 00:54:00,520 - I'm hoping, again, to see a shoal of hammerheads. 749 00:54:03,400 --> 00:54:07,160 We drop down again, falling through the blue. 750 00:54:19,880 --> 00:54:23,440 Then, finally, it's a lone hammerhead shark. 751 00:54:25,920 --> 00:54:28,320 A sentry? A sentinel? 752 00:54:33,960 --> 00:54:37,200 It slips back down into the deep blue, 753 00:54:37,200 --> 00:54:39,200 perhaps to a larger shoal. 754 00:54:43,400 --> 00:54:49,000 We take a calculated risk and follow, dropping down further, 755 00:54:49,000 --> 00:54:51,480 keeping a careful eye on our air supply. 756 00:55:07,600 --> 00:55:10,040 And then magic, 757 00:55:10,040 --> 00:55:11,600 wonder. 758 00:55:24,680 --> 00:55:26,560 Scalloped hammerhead sharks. 759 00:55:28,520 --> 00:55:29,680 Scores of them. 760 00:55:37,680 --> 00:55:42,360 Critically endangered, but still hanging on here. 761 00:55:57,280 --> 00:56:00,040 It is a truly extraordinary way 762 00:56:00,040 --> 00:56:03,000 to end my journey down the Sea of Cortez. 763 00:56:17,320 --> 00:56:18,840 That felt quite dreamlike. 764 00:56:21,520 --> 00:56:27,120 It was just a moment of almost ethereal beauty. 765 00:56:27,120 --> 00:56:30,160 When I was in the middle of this whirling mass 766 00:56:30,160 --> 00:56:33,920 of hammerhead sharks going round and round. 767 00:56:33,920 --> 00:56:37,120 They're beneath us still now in the ocean. 768 00:56:37,120 --> 00:56:40,520 It was incredibly memorable 769 00:56:40,520 --> 00:56:44,680 and special to be part of their world, even just for a moment. 770 00:56:46,000 --> 00:56:48,400 This is one of the few places left, 771 00:56:48,400 --> 00:56:54,160 in the Sea of Cortez, where hammerheads shoal like that. 772 00:56:54,160 --> 00:56:56,640 Now, of course, that is disappointing, 773 00:56:56,640 --> 00:57:01,440 but it makes this place very, very special in its own right. 774 00:57:01,440 --> 00:57:05,040 And I leave the Sea of Cortez, I finish this journey, 775 00:57:05,040 --> 00:57:07,160 actually feeling really quite hopeful, because I think 776 00:57:07,160 --> 00:57:10,920 I've really seen proof on this journey 777 00:57:10,920 --> 00:57:15,280 as much as any other I've been on that when we protect an area, 778 00:57:15,280 --> 00:57:18,920 when we stop killing the life within it, 779 00:57:18,920 --> 00:57:24,840 then nature can be restored and it can be renewed. 780 00:57:24,840 --> 00:57:26,520 There is hope! 781 00:57:42,440 --> 00:57:43,520 Next time... 782 00:57:43,520 --> 00:57:47,080 This is the source of the mighty Yukon River. 783 00:57:47,080 --> 00:57:49,960 ..I'm crossing the wilds of North America... 784 00:57:49,960 --> 00:57:51,440 I nearly went then. 785 00:57:51,440 --> 00:57:54,800 HE MAKES ANIMAL CALL ..out trekking... 786 00:57:54,800 --> 00:57:56,920 ..with the people of the Yukon. 787 00:57:56,920 --> 00:57:58,320 (It's coming this way.) 788 00:57:59,880 --> 00:58:01,960 And in their mountain sanctuary, 789 00:58:01,960 --> 00:58:04,720 I'll seek out Canada's apex predator. 790 00:58:04,720 --> 00:58:08,240 This is one of the great icons of the Canadian wilderness. 791 00:58:11,200 --> 00:58:13,960 Discover how rewilding could help recover areas 792 00:58:13,960 --> 00:58:17,280 where wilderness has been lost due to human activity. 793 00:58:17,280 --> 00:58:21,040 Take an interactive journey back in time with the Open University 794 00:58:21,040 --> 00:58:23,560 by scanning the QR code on your screen, 795 00:58:23,560 --> 00:58:25,360 or by going to...