1 00:00:02,000 --> 00:00:07,000 Downloaded from YTS.MX 2 00:00:02,700 --> 00:00:05,100 [Tristan Guttridge] It's a hammer. It's a hammer. Woo! 3 00:00:07,100 --> 00:00:10,700 [Tristan] In Andros, there are some huge great hammerheads. 4 00:00:08,000 --> 00:00:13,000 Official YIFY movies site: YTS.MX 5 00:00:12,800 --> 00:00:14,900 [Andy Casagrande] They can become over a thousand pounds. 6 00:00:16,700 --> 00:00:20,270 They can literally reach 20 feet long. 7 00:00:20,270 --> 00:00:23,330 What do these great hammerheads need to eat 8 00:00:23,370 --> 00:00:25,430 that will sustain that size? 9 00:00:25,470 --> 00:00:28,170 [Tristan] Most people really consider the hammerhead 10 00:00:28,230 --> 00:00:30,000 as kind of like a stingray specialist. 11 00:00:30,070 --> 00:00:33,370 But now new evidence suggests... 12 00:00:33,430 --> 00:00:35,170 great hammerheads in Andros 13 00:00:35,170 --> 00:00:37,800 actually specialize hunting other sharks. 14 00:00:38,970 --> 00:00:40,700 [man] Working on another shark. 15 00:00:40,730 --> 00:00:42,470 [man] Holy [bleep]. 16 00:00:42,500 --> 00:00:44,530 [Andy] Just recently right here in Andros, 17 00:00:44,530 --> 00:00:46,330 some of the most incredible footage 18 00:00:46,370 --> 00:00:48,800 was captured of a massive great hammerhead 19 00:00:48,870 --> 00:00:51,170 hunting a shark right underneath 20 00:00:51,230 --> 00:00:53,330 -a fisherman's boat. -[man] Oh, God. 21 00:00:54,800 --> 00:00:56,970 [Khrys Carroll] What's so unique about Andros Island 22 00:00:57,000 --> 00:01:00,270 is the hammerheads have little to no interaction with humans. 23 00:01:00,270 --> 00:01:02,370 [Tristan speaking] 24 00:01:02,430 --> 00:01:04,730 [Andy] Andros is the Wild, Wild West. 25 00:01:04,730 --> 00:01:07,700 -[Tristan speaking] -Whoa! Whoa! 26 00:01:07,730 --> 00:01:09,800 [Annie Guttridge] We wanna know, are these great hammerheads 27 00:01:09,870 --> 00:01:12,370 here in Andros hunting smaller sharks? 28 00:01:14,100 --> 00:01:15,730 [Tristan] It's a hammer. It's a hammer. 29 00:01:15,730 --> 00:01:18,170 -[man] You gotta be careful. -[Annie] Careful, careful, careful, careful. 30 00:01:26,700 --> 00:01:29,900 My name is Dr. Tristan Guttridge. I'm a behavioral ecologist. 31 00:01:29,900 --> 00:01:31,730 I've been working with great hammerhead sharks 32 00:01:31,800 --> 00:01:33,370 for over a decade. 33 00:01:35,800 --> 00:01:39,000 To me, the great hammerhead is one of the most iconic, 34 00:01:39,000 --> 00:01:42,229 charismatic shark species that lives on the planet. 35 00:01:42,270 --> 00:01:46,430 They reach huge sizes. I'm talking almost 20 feet. 36 00:01:46,470 --> 00:01:48,870 Plus, they have a head that is shaped like a hammer. 37 00:01:48,900 --> 00:01:51,900 And they use that hammer to pin prey down. 38 00:01:56,270 --> 00:01:58,170 Hammerheads are perfectly evolved 39 00:01:58,229 --> 00:01:59,900 for hunting stingrays. 40 00:01:59,970 --> 00:02:01,600 [Tristan] But now new evidence 41 00:02:01,630 --> 00:02:04,000 here in Andros suggests 42 00:02:04,000 --> 00:02:06,800 these hammerheads are reaching huge sizes 43 00:02:06,870 --> 00:02:10,900 by specializing on hunting other sharks. 44 00:02:10,970 --> 00:02:13,430 [man] That is crazy. Look at this hammerhead. 45 00:02:13,470 --> 00:02:17,870 Oh, it's trying to eat a shark. Oh, my God. 46 00:02:17,900 --> 00:02:20,430 Holy [bleep]. 47 00:02:21,870 --> 00:02:24,900 [Annie] We had a local fisher here showing 48 00:02:24,970 --> 00:02:27,270 a great hammerhead hunting on another shark. 49 00:02:28,630 --> 00:02:30,630 [man] He's working on another shark. 50 00:02:30,630 --> 00:02:32,329 [man] Holy [bleep]. 51 00:02:32,370 --> 00:02:34,600 The lemon shark was probably like six feet. 52 00:02:34,630 --> 00:02:36,730 The hammerhead was twice its size. 53 00:02:38,170 --> 00:02:39,730 [man] Oh, God. 54 00:02:41,530 --> 00:02:43,470 [Skye Minnis] And it was just chasing it, 55 00:02:43,500 --> 00:02:45,630 trying to get a snack. 56 00:02:45,700 --> 00:02:48,700 [narrator] Researchers need to determine if these videos 57 00:02:48,730 --> 00:02:50,630 are of isolated events 58 00:02:50,630 --> 00:02:53,170 or if they're a sign of a shocking change 59 00:02:53,170 --> 00:02:56,730 to the diet of great hammerheads of Andros Island. 60 00:02:56,730 --> 00:02:59,800 [Tristan] Andros is just a few hundred miles from the US. 61 00:02:59,870 --> 00:03:02,370 It's the biggest island in The Bahamas. 62 00:03:02,430 --> 00:03:04,530 It's critical for us to understand the role 63 00:03:04,600 --> 00:03:06,730 that these bigger predators play in this system 64 00:03:06,730 --> 00:03:08,000 to keep it healthy. 65 00:03:08,070 --> 00:03:09,630 [narrator] But the only way to figure out 66 00:03:09,630 --> 00:03:11,530 what these hammerheads are eating 67 00:03:11,530 --> 00:03:15,100 is to send live tissue samples to an outside lab. 68 00:03:17,870 --> 00:03:20,000 [Tristan] We're gonna take muscle samples 69 00:03:20,000 --> 00:03:21,870 from the great hammerheads themselves. 70 00:03:21,900 --> 00:03:24,370 We can take that sample and we can analyze 71 00:03:24,430 --> 00:03:26,070 its chemical composition. 72 00:03:26,100 --> 00:03:28,170 We can learn about what this hammerhead 73 00:03:28,170 --> 00:03:31,070 has been eating across the last year of its life. 74 00:03:32,600 --> 00:03:34,630 [narrator] To get the sample, they have to get 75 00:03:34,700 --> 00:03:36,530 within inches of the hammerhead. 76 00:03:42,170 --> 00:03:43,800 To get this job done safely 77 00:03:43,870 --> 00:03:46,370 for both the humans and the sharks, 78 00:03:46,430 --> 00:03:49,500 Tristan has assembled an all-star team. 79 00:03:49,530 --> 00:03:50,800 [Tristan] All right. Load up. 80 00:03:50,800 --> 00:03:52,800 [narrator] Including local shark experts, 81 00:03:52,870 --> 00:03:53,870 Khrys Carroll... 82 00:03:53,900 --> 00:03:56,270 I'm a marine scientist with Saving the Blue. 83 00:03:56,270 --> 00:03:58,000 [narrator] and Skye Minnis. 84 00:03:58,070 --> 00:04:00,170 [Skye] I grew up in the ocean 85 00:04:00,230 --> 00:04:03,100 fishing in the shallows with my grandmother. 86 00:04:03,100 --> 00:04:04,800 Now, I am a student at BAMSI. 87 00:04:04,800 --> 00:04:06,800 [narrator] Another Andros local joining 88 00:04:06,800 --> 00:04:09,270 the team is Rontaa Bain, 89 00:04:09,330 --> 00:04:12,070 an experienced freediver with the skills required 90 00:04:12,100 --> 00:04:16,899 to take biopsy samples from free swimming great hammerhead sharks. 91 00:04:16,970 --> 00:04:18,529 [Rontaa] The biggest hammerhead I ever seen 92 00:04:18,529 --> 00:04:20,700 was four meters. I thought it was a boat. 93 00:04:20,730 --> 00:04:22,370 [narrator] Watching their backs 94 00:04:22,370 --> 00:04:24,100 is experienced underwater cameraman, 95 00:04:24,170 --> 00:04:25,600 Andy Casagrande. 96 00:04:25,630 --> 00:04:27,470 For the past 20 years, I've traveled 97 00:04:27,500 --> 00:04:28,900 all over the planet 98 00:04:28,970 --> 00:04:31,600 filming nearly every species of shark. 99 00:04:31,630 --> 00:04:33,970 The great hammerhead is one of my favorites. 100 00:04:34,000 --> 00:04:35,800 [narrator] And Tristan's wife, Annie, 101 00:04:35,870 --> 00:04:37,730 a fearless freediver 102 00:04:37,800 --> 00:04:39,230 who has worked with hammerheads 103 00:04:39,270 --> 00:04:41,730 for over a decade. 104 00:04:42,730 --> 00:04:46,000 Together, they've devised a radical new plan 105 00:04:46,070 --> 00:04:49,600 to lure in giant hammerheads for biopsies. 106 00:04:49,630 --> 00:04:51,870 [Tristan] Taking muscle samples from the great 107 00:04:51,900 --> 00:04:54,630 hammerheads themselves is extremely challenging. 108 00:04:54,700 --> 00:04:56,230 So we've designed 109 00:04:56,270 --> 00:04:57,970 three state-of-the-art decoys. 110 00:04:58,000 --> 00:04:59,600 We've got Octobot 111 00:04:59,630 --> 00:05:01,100 that's gonna mimic 112 00:05:01,100 --> 00:05:03,600 a large octopus or a big squid. 113 00:05:03,630 --> 00:05:05,170 We've got Roboshark here 114 00:05:05,170 --> 00:05:07,270 that's gonna mimic a blacknose, 115 00:05:07,270 --> 00:05:09,000 a small coastal species, 116 00:05:09,000 --> 00:05:11,430 to hopefully see what hammerheads do with sharks. 117 00:05:11,470 --> 00:05:13,730 And, of course, the return of our good friend, 118 00:05:13,730 --> 00:05:17,230 Roboray, mimics a southern stingray. 119 00:05:17,270 --> 00:05:19,370 These look super realistic. 120 00:05:19,430 --> 00:05:22,470 [Andy] Roboray. Roboray. 121 00:05:22,500 --> 00:05:24,430 Last year we had a great hammerhead 122 00:05:24,470 --> 00:05:26,870 come hard in on Roboray. 123 00:05:29,000 --> 00:05:31,470 And I'm excited to try her again. 124 00:05:31,500 --> 00:05:35,100 [narrator] Roboray is best suited for attracting hammerheads 125 00:05:35,100 --> 00:05:37,800 in shallow sandy bottom environments. 126 00:05:37,800 --> 00:05:40,470 But the team has plans to explore 127 00:05:40,500 --> 00:05:43,970 all of Andros' unique underwater habitats, 128 00:05:44,000 --> 00:05:47,900 and that's where Roboshark and Octobot come into play. 129 00:05:47,900 --> 00:05:50,170 [Tristan] We've designed Octobot to draw in 130 00:05:50,230 --> 00:05:52,500 a hammerhead where cephalopods, 131 00:05:52,530 --> 00:05:55,270 squid are coming up during the night to feed. 132 00:05:55,270 --> 00:05:58,470 Roboshark, it's the perfect size 133 00:05:58,500 --> 00:06:00,800 for cruising reef habitat. 134 00:06:01,730 --> 00:06:04,170 The decoy delta force. 135 00:06:04,230 --> 00:06:06,900 I mean, I think any big shark, they're gonna come in and check it out. 136 00:06:06,900 --> 00:06:10,100 These decoys will create a distraction 137 00:06:10,100 --> 00:06:11,600 and then you can come in-- 138 00:06:11,630 --> 00:06:13,170 And get the biopsy. 139 00:06:13,170 --> 00:06:15,500 -[Tristan] Exactly. -[Andy] Yes. 140 00:06:15,530 --> 00:06:18,270 Some people might think it's very unorthodox, 141 00:06:18,270 --> 00:06:20,730 but in my opinion, unless you think outside the box, 142 00:06:20,800 --> 00:06:23,170 swim outside the cage, you're never gonna learn 143 00:06:23,170 --> 00:06:25,630 anything new about these animals. 144 00:06:25,630 --> 00:06:28,430 Plan is to set up on three different locations 145 00:06:28,470 --> 00:06:30,170 in real diverse habitats. 146 00:06:30,230 --> 00:06:32,630 Predator Channel in this area here. 147 00:06:32,630 --> 00:06:35,530 [Khrys] Predator Channel, we've known to see 148 00:06:35,530 --> 00:06:37,000 massive great hammerheads. 149 00:06:38,530 --> 00:06:41,100 [Tristan] The dropoff is a perfect launching site 150 00:06:41,170 --> 00:06:42,900 for Octobot. 151 00:06:44,500 --> 00:06:47,500 And then we have Stingray Shelf where we've seen 152 00:06:47,530 --> 00:06:50,870 lots of stingrays before, other small sharks as well. 153 00:06:53,630 --> 00:06:55,900 I just have one question. 154 00:06:55,900 --> 00:06:58,370 What's up with your Mohawk, ABC? 155 00:06:58,430 --> 00:06:59,900 It's not a Mohawk. 156 00:06:59,900 --> 00:07:02,000 It's a shark-hawk. 157 00:07:02,800 --> 00:07:05,500 -Sorry, buddy. -[laughter] 158 00:07:05,530 --> 00:07:07,500 -[Tristan] Everyone ready? -[Skye] Let's do it. 159 00:07:10,730 --> 00:07:13,000 [Tristan] Today, we're starting at Predator Channel. 160 00:07:13,070 --> 00:07:14,270 Old faithful. 161 00:07:14,270 --> 00:07:16,600 It's the site that I've seen the most great hammerheads 162 00:07:16,630 --> 00:07:19,000 here in Andros and a great location 163 00:07:19,070 --> 00:07:20,970 to deploy Roboshark 164 00:07:21,000 --> 00:07:22,970 because it's this transition zone 165 00:07:23,000 --> 00:07:25,270 from the dropoff to the flats. 166 00:07:25,330 --> 00:07:27,070 That's where these hammerheads are working 167 00:07:27,100 --> 00:07:30,100 'cause they can launch attacks. 168 00:07:30,100 --> 00:07:33,000 [narrator] Besides being a known hammerhead hotspot, 169 00:07:33,730 --> 00:07:36,270 Predator Channel is also the location 170 00:07:36,270 --> 00:07:38,470 in which local fishermen recently filmed 171 00:07:38,500 --> 00:07:41,730 the great hammerhead hunting a smaller shark. 172 00:07:42,800 --> 00:07:44,630 [Annie] So we're here in Predator Channel. 173 00:07:44,630 --> 00:07:47,730 We're setting up our BRUV to deploy Roboshark. 174 00:07:47,730 --> 00:07:49,800 So we have some freshly caught yellowtail. 175 00:07:49,870 --> 00:07:51,630 They're very abundant in The Bahamas. 176 00:07:51,630 --> 00:07:53,800 We don't typically filet them 177 00:07:53,870 --> 00:07:56,000 but when we're working with blunt knives, 178 00:07:56,000 --> 00:07:57,600 we make it work. 179 00:07:57,630 --> 00:08:00,370 Annie's gonna be preparing bait for the BRUV, 180 00:08:00,370 --> 00:08:02,800 a baited remote underwater video camera 181 00:08:02,870 --> 00:08:04,800 that has a live feed. 182 00:08:06,330 --> 00:08:08,170 And I'm gonna be scanning the water 183 00:08:08,170 --> 00:08:09,870 for a great hammerhead. 184 00:08:09,900 --> 00:08:11,630 [dramatic music playing] 185 00:08:15,900 --> 00:08:18,500 [Khrys] What are you doing? That is disgusting. 186 00:08:18,530 --> 00:08:21,530 This is the glamorous part of shark week. 187 00:08:28,600 --> 00:08:31,230 No. Oh. 188 00:08:31,270 --> 00:08:32,870 -[Andy] Oh, God. -No. 189 00:08:35,700 --> 00:08:39,169 I've just been sick a little bit in my mouth. 190 00:08:39,169 --> 00:08:41,370 -You want another bit? -[Khrys] I would love another piece. 191 00:08:41,370 --> 00:08:43,270 -Please don't. -Fresh mackerel is probably pretty good. 192 00:08:43,270 --> 00:08:44,530 Mmm. 193 00:08:46,000 --> 00:08:47,370 -[laughs] -Primo. 194 00:08:47,430 --> 00:08:48,600 [Andy] Wow. 195 00:08:48,630 --> 00:08:49,700 No. 196 00:08:49,730 --> 00:08:53,100 [dramatic music playing] 197 00:09:20,100 --> 00:09:21,730 [Tristan] Hammer! Hammer! 198 00:09:21,730 --> 00:09:23,800 [Skye] Hammerhead! Hammer, hammer, hammer! 199 00:09:23,870 --> 00:09:25,530 People! 200 00:09:25,600 --> 00:09:27,600 [Annie] Where's Andy? Andy? 201 00:09:27,630 --> 00:09:31,000 [indistinct chatter] 202 00:09:31,000 --> 00:09:32,070 It's a big female. 203 00:09:32,100 --> 00:09:33,700 Get Roboshark ready. 204 00:09:33,730 --> 00:09:35,070 She's headed towards the wreck. 205 00:09:35,100 --> 00:09:36,730 [narrator] Tristan has spotted 206 00:09:36,800 --> 00:09:39,270 the ideal candidate for a tissue sample. 207 00:09:40,270 --> 00:09:43,270 A great hammerhead that's around 12 feet long. 208 00:09:43,330 --> 00:09:46,230 Large enough to be a shark killer. 209 00:09:48,170 --> 00:09:50,330 [Tristan speaking] 210 00:09:50,370 --> 00:09:52,600 [Khrys speaking] 211 00:09:53,600 --> 00:09:57,630 [Tristan speaking] 212 00:09:57,700 --> 00:09:59,970 [Andy speaking] 213 00:10:01,730 --> 00:10:05,430 [Tristan speaking] 214 00:10:06,970 --> 00:10:08,230 Just interesting. 215 00:10:08,270 --> 00:10:10,530 How is everything down there? Anything yet? 216 00:10:10,600 --> 00:10:12,370 [Andy speaking] 217 00:10:14,630 --> 00:10:17,530 [Tristan speaking] 218 00:10:20,170 --> 00:10:23,070 [Andy speaking] 219 00:10:24,870 --> 00:10:31,000 [Tristan speaking] 220 00:10:35,230 --> 00:10:38,430 Tristan, ABC, the live feed is in position. 221 00:10:38,470 --> 00:10:40,530 Say cheese, guys. 222 00:10:42,970 --> 00:10:46,170 [Tristan speaking] 223 00:10:48,800 --> 00:10:50,870 [Andy speaking] 224 00:10:53,700 --> 00:10:56,900 [Tristan speaking] 225 00:11:07,730 --> 00:11:10,870 [Tristan speaking] 226 00:11:20,870 --> 00:11:23,100 [narrator] Even though this female tiger shark 227 00:11:23,170 --> 00:11:24,970 is just a juvenile, 228 00:11:25,000 --> 00:11:26,630 it could one day grow 229 00:11:26,630 --> 00:11:28,870 to be up to 16 feet long 230 00:11:28,900 --> 00:11:31,730 and weigh more than 2,000 pounds. 231 00:11:39,500 --> 00:11:43,900 [Tristan speaking] 232 00:11:54,370 --> 00:11:56,100 [Tristan speaking] 233 00:12:06,700 --> 00:12:08,500 I think I see a fin off the back of the boat. 234 00:12:08,530 --> 00:12:10,870 No, no, no. There. There. It's a hammer. 235 00:12:10,900 --> 00:12:12,730 Oh. That's a hammerhead. That's a hammerhead. 236 00:12:12,730 --> 00:12:13,630 Big. Yes. 237 00:12:13,630 --> 00:12:15,330 [Rontaa] A hundred percent real. 238 00:12:15,370 --> 00:12:17,630 -Guys, that is [bleep] huge. -Where is it? 239 00:12:17,700 --> 00:12:20,270 -Holy [bleep]. -[Skye laughs] 240 00:12:20,330 --> 00:12:26,000 [Khrys speaking] 241 00:12:26,070 --> 00:12:27,000 [Tristan speaking] 242 00:12:27,970 --> 00:12:30,000 [Khrys speaking] 243 00:12:30,070 --> 00:12:34,100 [Tristan speaking] 244 00:12:34,100 --> 00:12:37,230 [dramatic music playing] 245 00:12:38,500 --> 00:12:41,600 [Tristan speaking] 246 00:12:52,770 --> 00:12:56,100 [Tristan speaking] 247 00:13:08,300 --> 00:13:10,570 [Khrys speaking] 248 00:13:12,370 --> 00:13:16,300 [Tristan speaking] 249 00:13:20,570 --> 00:13:23,100 -[Annie] Rontaa, biopsy. -[narrator] With this 12-foot 250 00:13:23,100 --> 00:13:25,400 hammerhead distracted by Roboshark, 251 00:13:25,470 --> 00:13:26,830 the team's freediver 252 00:13:26,900 --> 00:13:28,830 and biopsy specialist, Rontaa, 253 00:13:28,830 --> 00:13:30,100 jumps in the water 254 00:13:30,100 --> 00:13:31,400 so he can get in position 255 00:13:31,400 --> 00:13:32,830 for a tissue sample. 256 00:13:33,830 --> 00:13:35,370 [Tristan speaking] 257 00:13:48,100 --> 00:13:49,800 -Whoa. -Oh, my God. 258 00:13:50,930 --> 00:13:53,030 [Tristan speaking] 259 00:13:56,300 --> 00:14:00,100 [narrator] By triggering a predatory attack from the hammerhead, 260 00:14:00,100 --> 00:14:03,930 Roboshark has done its job a little too well. 261 00:14:03,930 --> 00:14:05,670 And with the shark leaving the area, 262 00:14:05,730 --> 00:14:07,530 the team calls the dive. 263 00:14:08,670 --> 00:14:12,800 [Tristan speaking] 264 00:14:14,370 --> 00:14:15,930 [Andy speaking] 265 00:14:15,930 --> 00:14:17,570 [Rontaa speaking] 266 00:14:17,570 --> 00:14:19,470 You guys head back in. 267 00:14:19,530 --> 00:14:22,000 [Tristan speaking] 268 00:14:23,900 --> 00:14:27,300 Wow. That was a beautiful hammerhead. 269 00:14:27,370 --> 00:14:29,730 -How big was it? -[Andy] Maybe 12 feet. 270 00:14:29,770 --> 00:14:32,270 Super confident shark. 271 00:14:32,300 --> 00:14:34,300 [narrator] Even though Roboshark malfunctioned 272 00:14:34,300 --> 00:14:37,770 before the team had a chance to biopsy the hammerhead, 273 00:14:37,800 --> 00:14:40,270 they still made important observations. 274 00:14:40,300 --> 00:14:42,470 [Andy] Tristan, that was pretty incredible, man. 275 00:14:42,470 --> 00:14:44,630 Roboshark didn't stand a chance. 276 00:14:44,670 --> 00:14:46,300 -[makes sound] -[laughs] 277 00:14:46,300 --> 00:14:48,100 [Andy] Yeah. That's pretty much what happened. 278 00:14:48,100 --> 00:14:50,200 With our decoy, we were able to elicit 279 00:14:50,200 --> 00:14:52,470 predatory behaviors of hammerheads that might 280 00:14:52,530 --> 00:14:55,570 be cruising that reef habitat. 281 00:14:55,570 --> 00:14:58,830 This is fantastic evidence that showcases 282 00:14:58,830 --> 00:15:01,030 the predatory prowess of these giant 283 00:15:01,100 --> 00:15:02,270 great hammerheads. 284 00:15:02,300 --> 00:15:03,670 But now we want to switch 285 00:15:03,730 --> 00:15:06,370 things up and bring out Octobot. 286 00:15:06,400 --> 00:15:09,770 We know that hammerheads feed out in the deep water, 287 00:15:09,800 --> 00:15:12,400 hitting squid and other cephalopods. 288 00:15:12,400 --> 00:15:14,570 So what I'm hoping to do is see 289 00:15:14,630 --> 00:15:16,630 what big hammerhead we can intercept 290 00:15:16,670 --> 00:15:19,100 that's cruising that zone. 291 00:15:19,100 --> 00:15:21,400 [narrator] Octobot was designed specifically 292 00:15:21,400 --> 00:15:25,200 for attracting hammerheads at night near dropoffs. 293 00:15:26,270 --> 00:15:28,770 This is where the shallows suddenly descent 294 00:15:28,800 --> 00:15:31,830 into thousands of feet of open water. 295 00:15:41,570 --> 00:15:43,770 As we know, octopus, squid, 296 00:15:43,800 --> 00:15:45,470 they come up at night to feed, 297 00:15:45,470 --> 00:15:48,030 and we have Octobot here. 298 00:15:48,100 --> 00:15:51,770 Tonight will be a dusk dive on the dropoff. 299 00:15:51,800 --> 00:15:54,400 We're gonna swim Octobot right over the dropoff 300 00:15:54,470 --> 00:15:57,100 that goes down to almost 10,000 feet. 301 00:16:01,470 --> 00:16:03,930 And this is where cephalopods, 302 00:16:03,930 --> 00:16:07,670 squid are coming up during the night to feed. 303 00:16:07,670 --> 00:16:10,270 So I'm taking the lights for bioluminescence, right? 304 00:16:10,300 --> 00:16:12,000 Right. So we've got the visual cue 305 00:16:12,030 --> 00:16:13,830 of the actual octopus and we've also got 306 00:16:13,830 --> 00:16:15,570 the lights too to mimic that. 307 00:16:15,570 --> 00:16:17,830 -That's pretty awesome. -[Tristan] We take this 308 00:16:17,900 --> 00:16:20,300 decoy down off the dropoff. 309 00:16:20,370 --> 00:16:22,170 Maybe we'll get a hit from one of these 310 00:16:22,200 --> 00:16:25,400 big hammerheads that feeds out in the pelagic zone, 311 00:16:25,470 --> 00:16:28,030 which is very different to some of the hammers that feed 312 00:16:28,030 --> 00:16:30,670 on stingrays and sharks on the flats. 313 00:16:30,670 --> 00:16:33,300 [narrator] The pelagic zone is the open ocean 314 00:16:33,300 --> 00:16:35,100 far from shore. 315 00:16:35,170 --> 00:16:37,670 And researchers believe great hammerheads hunt 316 00:16:37,670 --> 00:16:41,000 at night here, where they can encounter lethal deep sea 317 00:16:41,030 --> 00:16:43,400 predators like swordfish 318 00:16:43,470 --> 00:16:45,770 and even the giant squid. 319 00:16:47,000 --> 00:16:49,100 In this dangerous environment, 320 00:16:49,100 --> 00:16:52,830 darkness can provide cover from prey that can bite back. 321 00:16:52,900 --> 00:16:54,400 So what do you think? 322 00:16:54,470 --> 00:16:57,570 Yeah, let's get kraken. 323 00:16:57,630 --> 00:16:59,400 Oh, my God. 324 00:16:59,400 --> 00:17:01,030 [Andy] Every time I go down 325 00:17:01,100 --> 00:17:03,000 in the dark underwater, 326 00:17:03,030 --> 00:17:04,730 it's a little unnerving 327 00:17:04,770 --> 00:17:06,900 because you can't see much further than your face. 328 00:17:09,730 --> 00:17:12,099 These rebreathers, they're great but it's hard work. 329 00:17:12,099 --> 00:17:16,000 -Yeah. -[Tristan] So check everything before you go in. 330 00:17:16,030 --> 00:17:17,829 [narrator] Besides monitoring their complex 331 00:17:17,900 --> 00:17:20,670 rebreather equipment, Tristan will also go 332 00:17:20,730 --> 00:17:23,670 for the all-important hammerhead tissue sample, 333 00:17:23,730 --> 00:17:25,900 -if one appears. -[Andy] All right. 334 00:17:25,930 --> 00:17:28,030 -Feeling good, Tristan? -Oh, yeah. I'm ready. 335 00:17:28,030 --> 00:17:29,830 [Andy] All right. Let's do this. 336 00:17:29,830 --> 00:17:32,930 Looks good. We'll see you in an hour or two. 337 00:17:34,530 --> 00:17:38,800 [Annie] Five, four, three, two, one. 338 00:17:56,670 --> 00:18:02,300 [Tristan speaking] 339 00:18:15,030 --> 00:18:17,470 [Andy speaking] 340 00:18:18,830 --> 00:18:22,530 [Tristan speaking] 341 00:18:23,300 --> 00:18:24,670 [Andy speaking] 342 00:18:26,630 --> 00:18:28,400 [narrator] Blacknose sharks can be found 343 00:18:28,400 --> 00:18:30,930 all over the southeast Atlantic. 344 00:18:31,000 --> 00:18:34,930 The largest this species gets is around six feet long, 345 00:18:34,930 --> 00:18:38,830 making them ideal prey for a shark-killing hammerhead. 346 00:18:39,570 --> 00:18:43,530 [Tristan speaking] 347 00:18:57,930 --> 00:19:02,270 [Andy speaking] 348 00:19:09,270 --> 00:19:12,470 [Tristan speaking] 349 00:19:12,530 --> 00:19:14,300 [Andy speaking] 350 00:19:18,030 --> 00:19:20,830 [Tristan speaking] 351 00:19:30,570 --> 00:19:33,300 [Tristan speaking] 352 00:19:37,200 --> 00:19:39,670 [Tristan speaking] 353 00:19:47,830 --> 00:19:50,030 [Andy speaking] 354 00:19:56,030 --> 00:19:58,200 [Tristan speaking] 355 00:20:08,670 --> 00:20:12,030 [Tristan speaking] 356 00:20:12,100 --> 00:20:15,170 [Andy speaking] 357 00:20:23,000 --> 00:20:24,670 [Tristan speaking] 358 00:20:41,670 --> 00:20:42,800 [Andy speaking] 359 00:20:46,670 --> 00:20:49,670 [Tristan speaking] 360 00:20:53,200 --> 00:20:54,830 [narrator] Before attacking, 361 00:20:54,830 --> 00:20:57,000 great hammerheads scan their surroundings 362 00:20:57,030 --> 00:21:00,900 with their massive hammer-shaped cephalofoils. 363 00:21:00,930 --> 00:21:03,200 These are covered in electroreceptors 364 00:21:03,200 --> 00:21:05,570 called ampullae of Lorenzini, 365 00:21:05,570 --> 00:21:07,770 which allow them to detect electrical currents 366 00:21:07,800 --> 00:21:09,030 like heartbeats 367 00:21:09,030 --> 00:21:11,530 or the small electric motors 368 00:21:11,570 --> 00:21:12,930 in Octobot. 369 00:21:16,830 --> 00:21:18,170 [Tristan] Oh! 370 00:21:24,170 --> 00:21:26,570 [Andy speaking] 371 00:21:27,730 --> 00:21:30,830 [Tristan speaking] 372 00:21:39,630 --> 00:21:41,400 [Andy speaking] 373 00:21:45,030 --> 00:21:48,400 [Tristan speaking] 374 00:21:58,170 --> 00:22:01,000 [Tristan speaking] 375 00:22:08,170 --> 00:22:10,800 [Tristan speaking] 376 00:22:10,830 --> 00:22:12,300 [Andy speaking] 377 00:22:13,370 --> 00:22:14,830 [narrator] In the dark, 378 00:22:14,900 --> 00:22:17,530 off Andros Island in The Bahamas, 379 00:22:17,570 --> 00:22:20,470 Tristan Guttridge and Andy Casagrande 380 00:22:20,530 --> 00:22:23,670 are using a squid decoy called Octobot 381 00:22:23,670 --> 00:22:26,170 to lure in monster hammerheads. 382 00:22:34,470 --> 00:22:37,570 [Tristan speaking] 383 00:22:39,830 --> 00:22:41,170 [Andy speaking] 384 00:22:43,730 --> 00:22:46,530 [Tristan speaking] 385 00:23:03,370 --> 00:23:05,100 We lost Octobot. 386 00:23:05,100 --> 00:23:07,000 Something just pulled it over the edge. 387 00:23:07,030 --> 00:23:09,100 [Annie] Yeah. We saw something big. 388 00:23:09,170 --> 00:23:11,200 The current is quite strong. 389 00:23:16,200 --> 00:23:19,670 Wow. I mean, we were in great position. 390 00:23:19,730 --> 00:23:22,300 We were right on the edge of the drop off, 391 00:23:22,370 --> 00:23:25,670 and then it yanked straight off my hand. 392 00:23:25,730 --> 00:23:27,100 Dude. 393 00:23:27,170 --> 00:23:30,530 Octobot live on in memory. 394 00:23:30,570 --> 00:23:31,930 Octobot. 395 00:23:32,000 --> 00:23:33,730 [chuckles] 396 00:23:37,570 --> 00:23:39,200 [Tristan] Last night was crazy. 397 00:23:39,270 --> 00:23:41,470 We had a huge great hammerhead. 398 00:23:44,830 --> 00:23:47,470 And as I was on the edge of the drop off, 399 00:23:48,470 --> 00:23:50,470 I was holding the controller 400 00:23:50,470 --> 00:23:52,470 and it got pulled out of my hands. 401 00:23:52,470 --> 00:23:54,200 [Andy] By the time we got to the drop off, 402 00:23:54,200 --> 00:23:55,900 Octobot was gone 403 00:23:55,930 --> 00:23:57,200 and it was impossible to retrieve. 404 00:23:57,270 --> 00:23:58,670 We're just not equipped to go 405 00:23:58,730 --> 00:23:59,930 that deep to recover. 406 00:24:00,000 --> 00:24:01,570 -That actually was a shark. -That was... That was a shark. 407 00:24:01,570 --> 00:24:03,530 -That is a shark. -That is... That was something. 408 00:24:03,570 --> 00:24:05,670 [narrator] Analysis from Octobot's camera 409 00:24:05,730 --> 00:24:07,570 at the moment the controller was ripped 410 00:24:07,630 --> 00:24:09,270 from Tristan's hands, 411 00:24:10,000 --> 00:24:12,670 shows something coming into frame. 412 00:24:12,730 --> 00:24:16,300 But whether or not it was a great hammerhead is unclear. 413 00:24:16,300 --> 00:24:19,530 If it is, the decoys might be working too well 414 00:24:19,570 --> 00:24:21,900 in eliciting predatory behavior. 415 00:24:26,530 --> 00:24:28,200 With Octobot gone 416 00:24:28,200 --> 00:24:30,730 and Roboshark in the shop for repairs, 417 00:24:30,730 --> 00:24:33,930 the team turns to their last decoy. 418 00:24:34,000 --> 00:24:35,530 [Andy] Now it's time to break out 419 00:24:35,570 --> 00:24:37,830 our old pal, Roboray. 420 00:24:37,900 --> 00:24:39,570 And we're gonna head to this awesome spot 421 00:24:39,630 --> 00:24:40,830 called Gibson Cay. 422 00:24:40,900 --> 00:24:42,730 It's a very productive area. 423 00:24:42,730 --> 00:24:44,200 There's sharks here. There's stingrays. 424 00:24:44,200 --> 00:24:45,930 There's lots of game fish. 425 00:24:45,930 --> 00:24:48,900 This place is a known area... 426 00:24:48,930 --> 00:24:51,900 where hammerheads come to hunt other sharks. 427 00:24:51,930 --> 00:24:54,730 This is where Annie and I saw the hammerhead predating 428 00:24:54,800 --> 00:24:56,270 on a shark in the shallows. 429 00:24:56,300 --> 00:24:57,730 [Annie] Oh, my God! 430 00:24:57,730 --> 00:24:59,300 She's hunting. She's on the reef shark. 431 00:24:59,300 --> 00:25:01,830 It's definitely hunting. Oh, my God! 432 00:25:01,830 --> 00:25:03,370 My God. Look at it there. 433 00:25:03,370 --> 00:25:05,570 [Rontaa] It's eating another shark. 434 00:25:05,570 --> 00:25:07,570 So we split up into two teams. 435 00:25:07,630 --> 00:25:10,630 I'm here with Khrys and Skye. 436 00:25:10,670 --> 00:25:12,300 Can you hand me that BRUV? 437 00:25:12,300 --> 00:25:14,100 [Andy] And we got Tristan and Annie. 438 00:25:14,170 --> 00:25:16,100 Right now, they're fishing over there. 439 00:25:16,100 --> 00:25:17,570 They're hoping to catch a big hammerhead 440 00:25:17,630 --> 00:25:18,730 and pull a biopsy, 441 00:25:18,800 --> 00:25:20,370 because we wanna know 442 00:25:20,370 --> 00:25:22,930 what these monster hammerheads are eating. 443 00:25:23,930 --> 00:25:25,430 This is number one, so 1A. 444 00:25:25,470 --> 00:25:27,070 It's why I like working with my wife 445 00:25:27,100 --> 00:25:29,930 'cause she's way more organized than me. 446 00:25:29,930 --> 00:25:31,300 [narrator] With two decoys down 447 00:25:31,300 --> 00:25:33,370 and no tissue samples yet, 448 00:25:33,370 --> 00:25:36,270 Tristan and Annie turn to drumline fishing, 449 00:25:36,300 --> 00:25:38,900 a tried and true method for hooking up hammerheads 450 00:25:38,930 --> 00:25:41,470 to get the biopsies they need. 451 00:25:41,470 --> 00:25:45,030 [Tristan] I haven't entirely abandoned the decoys 452 00:25:45,070 --> 00:25:47,730 but we have now moved to a more traditional method 453 00:25:47,730 --> 00:25:49,300 which is catch and release, 454 00:25:49,370 --> 00:25:51,730 where we can take a biological tissue sample, 455 00:25:51,800 --> 00:25:53,370 muscle from the side of a vessel 456 00:25:53,370 --> 00:25:55,170 in a more controlled manner. 457 00:25:56,170 --> 00:25:57,570 So we're deploying some drumlines. 458 00:25:57,630 --> 00:25:59,170 We have a weight 459 00:25:59,200 --> 00:26:01,930 which is connected to this long yellow line, 460 00:26:02,000 --> 00:26:03,930 which is then connected to some buoys 461 00:26:04,000 --> 00:26:05,200 and then some mono. 462 00:26:06,170 --> 00:26:07,830 [Tristan] The advantage of using the drumlines 463 00:26:07,830 --> 00:26:09,370 is that we can actually have the animal 464 00:26:09,370 --> 00:26:11,270 next to the side of the vessel 465 00:26:11,300 --> 00:26:13,370 and be able to get much more detailed information 466 00:26:13,370 --> 00:26:14,830 by being able to capture them. 467 00:26:14,900 --> 00:26:16,530 There is a downside. 468 00:26:16,570 --> 00:26:19,370 It's quite a high pressure situation. 469 00:26:19,370 --> 00:26:22,430 You're dealing with a huge animal that has big teeth, 470 00:26:22,470 --> 00:26:24,930 that can slap you in the face with its big tail. 471 00:26:25,000 --> 00:26:27,030 So you really need to be quick and efficient 472 00:26:27,070 --> 00:26:28,930 and make sure that you're being safe 473 00:26:28,930 --> 00:26:30,930 when you're working with these big sharks. 474 00:26:32,300 --> 00:26:33,800 -[Annie] Tristan, you ready? -Yeah. 475 00:26:33,830 --> 00:26:35,100 A little bit further. 476 00:26:35,170 --> 00:26:36,830 [Annie chuckles] Not ready. 477 00:26:36,830 --> 00:26:38,170 [Tristan] Okay. It's good here. 478 00:26:40,470 --> 00:26:42,800 We're actually gonna be set anchored 479 00:26:42,830 --> 00:26:45,670 just around 500 feet away from these rigs 480 00:26:45,670 --> 00:26:47,300 so we can see if anything gets caught 481 00:26:47,370 --> 00:26:49,170 and then we can go straight to it, 482 00:26:49,200 --> 00:26:52,070 work it up, measure it, take our muscle sample, 483 00:26:52,100 --> 00:26:53,830 and then the shark will hopefully be swimming 484 00:26:53,830 --> 00:26:56,830 from bite to release within 12 or 15 minutes. 485 00:26:58,030 --> 00:27:00,100 -Nice. -Very nice. 486 00:27:00,170 --> 00:27:02,030 We're now set up. You can see the rigs. 487 00:27:02,070 --> 00:27:04,370 We've got one, two, three, four, five 488 00:27:04,370 --> 00:27:06,630 -across the channel. -[Annie] When a hammer hits, 489 00:27:06,670 --> 00:27:08,370 we certainly will know about it. 490 00:27:09,630 --> 00:27:11,200 [narrator] With their drumlines set, 491 00:27:11,270 --> 00:27:13,670 Annie and Tristan wait for a hit, 492 00:27:13,670 --> 00:27:16,570 while Andy, Khrys, and Skye prepare to jump in 493 00:27:16,630 --> 00:27:18,670 with Roboray. 494 00:27:18,670 --> 00:27:20,100 I think this is the perfect place. 495 00:27:20,170 --> 00:27:23,270 [Andy] All right. Roboray, game time. 496 00:27:23,300 --> 00:27:25,430 [Skye] We're gonna use the return of Roboray 497 00:27:25,470 --> 00:27:28,100 to get the hammerheads in really close 498 00:27:28,100 --> 00:27:30,730 to collect a tissue sample. 499 00:27:30,730 --> 00:27:33,470 Me and Khrys, we're gonna have front row seat 500 00:27:33,530 --> 00:27:35,670 and we're gonna see what comes in. 501 00:27:35,670 --> 00:27:37,470 I'll keep my eyes open for any hammers 502 00:27:37,530 --> 00:27:39,370 or any other tigers that might be in the area. 503 00:27:39,430 --> 00:27:41,200 What could go wrong? 504 00:27:41,270 --> 00:27:43,570 -[Skye] Let's do this. -[Khrys] Okay. Cool. 505 00:27:50,470 --> 00:27:52,000 [narrator] The team has also deployed 506 00:27:52,030 --> 00:27:53,800 over a dozen BRUVs, 507 00:27:53,830 --> 00:27:55,300 which are baited cameras 508 00:27:55,370 --> 00:27:58,430 rigged with up to 25 pounds of tuna. 509 00:27:58,470 --> 00:28:00,570 Between the BRUVs and Roboray, 510 00:28:00,570 --> 00:28:02,830 any great hammerheads in the area 511 00:28:02,900 --> 00:28:04,570 are in for a feast. 512 00:28:10,200 --> 00:28:13,300 [Skye speaking] 513 00:28:15,570 --> 00:28:16,800 [Khrys speaking] 514 00:28:37,900 --> 00:28:40,470 [Skye speaking] 515 00:28:40,530 --> 00:28:43,470 [Khrys speaking] 516 00:28:44,800 --> 00:28:46,830 [narrator] Nurse sharks are bottom feeders. 517 00:28:46,830 --> 00:28:50,100 They eat almost anything they find on the ocean floor, 518 00:28:50,170 --> 00:28:53,530 crushing coral, crustaceans, and small bony fish 519 00:28:53,570 --> 00:28:56,730 with their many rows of small serrated teeth. 520 00:28:59,270 --> 00:29:02,930 [Skye speaking] 521 00:29:02,930 --> 00:29:05,930 [Khrys speaking] 522 00:29:05,930 --> 00:29:08,630 [Skye speaking] 523 00:29:11,030 --> 00:29:12,730 [narrator] Another species takes interest 524 00:29:12,730 --> 00:29:14,300 in the team's bait. 525 00:29:15,200 --> 00:29:17,470 Reef sharks like this are a cornerstone 526 00:29:17,530 --> 00:29:20,000 of the habitats around Andros. 527 00:29:22,530 --> 00:29:25,370 [Skye speaking] 528 00:29:27,670 --> 00:29:28,900 [narrator] Reef sharks might have learned 529 00:29:28,930 --> 00:29:30,570 to find safety in numbers, 530 00:29:30,570 --> 00:29:32,200 because when they're young, 531 00:29:32,200 --> 00:29:34,470 they're hunted by great hammerheads. 532 00:29:40,670 --> 00:29:43,470 [Skye speaking] 533 00:29:49,370 --> 00:29:51,030 [Khrys speaking] 534 00:30:02,800 --> 00:30:03,800 [Skye] Whoa! 535 00:30:08,130 --> 00:30:10,300 [Khrys speaking] 536 00:30:11,670 --> 00:30:13,870 [Skye speaking] 537 00:30:13,930 --> 00:30:16,870 [Khrys speaking] 538 00:30:17,840 --> 00:30:20,030 [Skye speaking] 539 00:30:20,100 --> 00:30:21,930 [Khrys speaking] 540 00:30:23,030 --> 00:30:25,740 [Skye speaking] 541 00:30:25,770 --> 00:30:26,970 [Andy] I copy you. 542 00:30:28,230 --> 00:30:29,670 Roboray is away. 543 00:30:29,670 --> 00:30:33,130 Repeat, Roboray is in the water. 544 00:30:33,200 --> 00:30:36,300 [suspenseful music playing] 545 00:30:44,840 --> 00:30:47,400 [Andy] We're sending in Rontaa. 546 00:30:47,400 --> 00:30:49,030 [narrator] With Roboray deployed, 547 00:30:49,100 --> 00:30:50,670 Rontaa hits the water, 548 00:30:50,740 --> 00:30:52,600 floating at the surface while he waits 549 00:30:52,600 --> 00:30:54,100 for the perfect opportunity 550 00:30:54,130 --> 00:30:56,230 to go in for a tissue sample. 551 00:30:58,400 --> 00:31:00,570 [Andy] Rontaa now is hovering above you guys. 552 00:31:00,600 --> 00:31:01,670 [Khrys speaking] 553 00:31:04,330 --> 00:31:07,400 [Skye speaking] 554 00:31:12,100 --> 00:31:13,770 [Khrys speaking] 555 00:31:26,130 --> 00:31:29,230 [Skye speaking] 556 00:31:31,500 --> 00:31:34,030 [Khrys speaking] 557 00:31:41,770 --> 00:31:43,030 [Skye] Whoa! 558 00:31:47,370 --> 00:31:50,470 [Khrys speaking] 559 00:31:52,370 --> 00:31:54,870 [Skye speaking] 560 00:31:56,570 --> 00:31:59,670 [Khrys speaking] 561 00:32:01,740 --> 00:32:05,500 [Andy speaking] 562 00:32:06,970 --> 00:32:08,670 [Khrys speaking] 563 00:32:08,670 --> 00:32:11,770 [Skye speaking] 564 00:32:15,970 --> 00:32:18,870 [Khrys speaking] 565 00:32:18,930 --> 00:32:20,130 [Andy] I copy you, Khrys. 566 00:32:24,670 --> 00:32:27,570 [narrator] Just like with Roboshark and Octobot, 567 00:32:28,870 --> 00:32:30,930 Roboray succeeds in eliciting 568 00:32:30,970 --> 00:32:32,770 a strong predatory response 569 00:32:32,840 --> 00:32:34,770 from a great hammerhead. 570 00:32:34,840 --> 00:32:37,600 But the shark takes off before the team has a chance 571 00:32:37,600 --> 00:32:39,600 to obtain a biopsy. 572 00:32:39,600 --> 00:32:41,030 -Yeah. -Whoo! 573 00:32:41,030 --> 00:32:42,670 What about that dive, guys. 574 00:32:42,670 --> 00:32:45,130 -That was awesome. -It was amazing. 575 00:32:45,130 --> 00:32:46,870 The surge was kind of gnarly 576 00:32:46,870 --> 00:32:49,670 but the sharks definitely came in full effect. 577 00:32:49,670 --> 00:32:52,030 That moment when we saw the hammerhead swim above us-- 578 00:32:52,100 --> 00:32:54,600 Yeah. That was... something else. 579 00:32:54,670 --> 00:32:56,400 It was like a buffet for the hammerhead. 580 00:32:56,470 --> 00:32:57,870 You had reefies, 581 00:32:57,930 --> 00:33:00,770 you had the little nurse, and Roboray. 582 00:33:00,770 --> 00:33:02,570 [Andy] Nice work. 583 00:33:02,600 --> 00:33:04,130 [makes explosive sound] 584 00:33:06,970 --> 00:33:08,570 One, two, three. 585 00:33:08,600 --> 00:33:09,670 So we just put another one there. 586 00:33:09,740 --> 00:33:11,570 Four and five. 587 00:33:11,600 --> 00:33:13,470 No bait. Rebait. 588 00:33:13,500 --> 00:33:15,970 -[Annie] What bait is it? -[Tristan] Cuda. 589 00:33:16,030 --> 00:33:18,400 So we've had some ups and downs with the decoys. 590 00:33:18,470 --> 00:33:20,100 These are smart sharks. 591 00:33:20,130 --> 00:33:21,470 But we do have a backup 592 00:33:21,500 --> 00:33:23,670 and that is we try and catch one of these animals 593 00:33:23,740 --> 00:33:25,970 and take a biopsy on the side of the boat. 594 00:33:26,030 --> 00:33:28,570 There's a higher chance of getting hooked by a hook 595 00:33:28,600 --> 00:33:31,130 than getting bit by a shark, definitely. 596 00:33:31,200 --> 00:33:33,030 -Ready to go in? -[Rontaa] Yup. 597 00:33:34,470 --> 00:33:35,670 Bait in. 598 00:33:35,670 --> 00:33:38,370 Like a well-oiled machine, 599 00:33:38,400 --> 00:33:40,500 research machine. 600 00:33:42,600 --> 00:33:43,870 Shark one! Shark one! 601 00:33:43,930 --> 00:33:46,870 -Shark one! -Oh, okay. Yes! 602 00:33:46,930 --> 00:33:48,300 Oh, wow. That's moving. 603 00:33:50,600 --> 00:33:53,300 Stephano, move round and go up the channel 604 00:33:53,330 --> 00:33:54,930 and then we'll pull it in from there. 605 00:33:57,600 --> 00:34:00,400 [narrator] The team's patience finally pays off... 606 00:34:01,400 --> 00:34:03,400 as Tristan and Annie get a hit 607 00:34:03,400 --> 00:34:05,030 on one of their drum lines. 608 00:34:10,500 --> 00:34:12,230 [Tristan] Slow down. Slow down. 609 00:34:13,130 --> 00:34:14,600 It's here on the left. 610 00:34:15,400 --> 00:34:17,130 It is a big shark 611 00:34:17,130 --> 00:34:19,500 'cause it's towing that line. 612 00:34:19,570 --> 00:34:21,840 [Annie] Definitely a big shark, a hundred percent. 613 00:34:21,870 --> 00:34:23,500 [Tristan] Can't see what it is. 614 00:34:23,500 --> 00:34:25,100 -Go over. -[Skye] We're right... 615 00:34:25,130 --> 00:34:27,100 We're right on top of it. 616 00:34:27,130 --> 00:34:29,500 Just be careful it doesn't get in your legs, Julian. 617 00:34:30,500 --> 00:34:31,969 -[Julian] It's a hammer! -[Tristan] It's a hammer! 618 00:34:31,969 --> 00:34:33,469 -It's a hammer! -[Julian] Oh, my God! 619 00:34:33,500 --> 00:34:35,230 -[Tristan] Woo! -[Julian] Woo! 620 00:34:35,300 --> 00:34:36,770 It's a hammerhead. 621 00:34:36,840 --> 00:34:37,840 We've caught a hammerhead 622 00:34:37,870 --> 00:34:39,030 in the channel. 623 00:34:42,030 --> 00:34:43,739 That is not small either. 624 00:34:43,770 --> 00:34:44,870 It's not small. 625 00:34:48,500 --> 00:34:50,770 [narrator] This hammerhead is 12 feet long, 626 00:34:50,840 --> 00:34:53,030 big enough to hunt other sharks. 627 00:34:53,030 --> 00:34:56,130 But the only way to see if this one is a shark killer 628 00:34:56,130 --> 00:34:58,030 is to get the tissue sample. 629 00:35:05,130 --> 00:35:06,770 [Annie] Definitely female I say, yeah? 630 00:35:06,770 --> 00:35:08,130 -Yeah. Yeah. -[Julian] Go, go, go, go, go, 631 00:35:08,200 --> 00:35:09,500 go, go, go, go, go. 632 00:35:09,570 --> 00:35:11,200 [Tristan] Can't get the tail. 633 00:35:11,230 --> 00:35:14,030 [grunts] We radioed them to let them know. 634 00:35:15,030 --> 00:35:16,840 [Stephano speaking] 635 00:35:16,870 --> 00:35:18,840 [Andy] Is it a hambone or they don't know? 636 00:35:18,870 --> 00:35:20,670 -[man] Is it hammer? -[Stephano speaking] 637 00:35:20,670 --> 00:35:21,970 -It's a hammer. It's a hammer. -What? 638 00:35:22,030 --> 00:35:23,970 -All right. Let's go. Let's go. -[Andy] Put the drone up. 639 00:35:30,870 --> 00:35:32,670 [Skye] Oh, look at that. 640 00:35:32,670 --> 00:35:34,670 They got it. 641 00:35:34,670 --> 00:35:35,740 [Khrys] That is awesome. 642 00:35:35,770 --> 00:35:37,330 What a beauty. 643 00:35:37,370 --> 00:35:39,130 Tristan and Annie just caught a hammerhead. 644 00:35:39,130 --> 00:35:40,670 They're gonna get a biopsy. 645 00:35:40,670 --> 00:35:41,770 I'm gonna jump in the water 646 00:35:41,840 --> 00:35:43,100 to film the release. 647 00:35:49,230 --> 00:35:50,870 [Annie] All right. Here we go. This is it, people. 648 00:35:50,870 --> 00:35:53,130 This is it. Nice and easy. 649 00:35:53,130 --> 00:35:54,770 This is it. 650 00:35:54,770 --> 00:35:56,770 Here she comes. 651 00:35:56,770 --> 00:35:58,130 [Tristan] Yeah, I've got it. 652 00:35:59,130 --> 00:36:00,570 Grab its head. 653 00:36:02,130 --> 00:36:03,500 Okay. Pass the biopsy. 654 00:36:03,570 --> 00:36:05,230 [Annie] Look out. Look out. 655 00:36:07,300 --> 00:36:08,400 -Tristan, stand by. -Yeah. I know. 656 00:36:08,400 --> 00:36:10,230 I'm ready. 657 00:36:10,300 --> 00:36:11,600 [Annie] All right. She's set. 658 00:36:11,600 --> 00:36:13,870 [Tristan] Let it go. Let it go. 659 00:36:13,930 --> 00:36:15,030 [Annie] Careful, careful, careful. Careful! 660 00:36:18,170 --> 00:36:19,140 [Tristan] Grab its head. 661 00:36:21,400 --> 00:36:22,700 [Annie] Careful, careful, careful. 662 00:36:22,700 --> 00:36:23,900 -Careful! -[Tristan] Let it go. 663 00:36:23,970 --> 00:36:25,270 [Annie] Tristan, what now? 664 00:36:25,270 --> 00:36:26,970 [Tristan] Okay. Pass the biopsy. 665 00:36:29,700 --> 00:36:31,500 All right. That's good enough. 666 00:36:33,530 --> 00:36:35,330 All right. We're gonna have to release it. 667 00:36:35,330 --> 00:36:36,800 [Annie] She's set. 668 00:36:38,500 --> 00:36:39,700 -She's about ready to go. -[Tristan] That's it. 669 00:36:39,700 --> 00:36:41,430 -Keep trying to get the hook out. -[Annie] Look out. 670 00:36:41,430 --> 00:36:42,400 -Tristan, stand by. -Yeah. I know. 671 00:36:42,430 --> 00:36:43,430 I'm ready. 672 00:36:44,430 --> 00:36:46,070 -She's good? She free? -She's free. 673 00:36:46,070 --> 00:36:48,330 [Tristan] Let her go. Let her go. 674 00:36:48,330 --> 00:36:49,630 She swims. 675 00:36:49,670 --> 00:36:52,700 [dramatic music playing] 676 00:36:59,530 --> 00:37:01,400 [cheering] 677 00:37:04,770 --> 00:37:05,970 Ow! 678 00:37:06,040 --> 00:37:07,400 Sorry. 679 00:37:11,970 --> 00:37:13,400 [Tristan] We got the muscle sample. 680 00:37:13,430 --> 00:37:14,900 We can essentially track 681 00:37:14,970 --> 00:37:16,770 what that hammerhead has been eating 682 00:37:16,800 --> 00:37:18,330 the last year. 683 00:37:18,400 --> 00:37:21,230 You are essentially what you eat. 684 00:37:21,270 --> 00:37:23,330 [narrator] At just under 12 feet long, 685 00:37:23,400 --> 00:37:26,070 the great hammerhead they sampled is well on its way 686 00:37:26,070 --> 00:37:29,530 to becoming one of the behemoths Andros is known for. 687 00:37:31,070 --> 00:37:33,970 And at that size, it's more than big enough 688 00:37:33,970 --> 00:37:35,800 to be a shark killer. 689 00:37:35,800 --> 00:37:37,270 [Tristan] And that's the muscle sample. 690 00:37:37,270 --> 00:37:39,040 Just putting it in here for now. 691 00:37:39,870 --> 00:37:42,970 And this is gold dust. 692 00:37:43,040 --> 00:37:46,400 We now need more samples from great hammerheads here 693 00:37:46,430 --> 00:37:48,170 to really try and understand 694 00:37:48,230 --> 00:37:51,970 if they're specializing on hunting other sharks. 695 00:37:54,670 --> 00:37:56,040 [narrator] But Tristan needs more 696 00:37:56,070 --> 00:37:58,170 than just hammerhead samples. 697 00:37:58,170 --> 00:38:00,500 For this comparative analysis to work, 698 00:38:00,530 --> 00:38:02,070 the team will also need tissue 699 00:38:02,140 --> 00:38:04,170 of potential hammerhead prey species 700 00:38:04,170 --> 00:38:05,430 in the area, 701 00:38:05,500 --> 00:38:07,270 including other sharks. 702 00:38:09,800 --> 00:38:11,270 Shark on! Shark on! 703 00:38:11,270 --> 00:38:13,530 [Tristan] The next big challenge is to go out 704 00:38:13,530 --> 00:38:15,530 and sample the prey species 705 00:38:15,530 --> 00:38:17,700 that these hammerheads are focusing on. 706 00:38:17,700 --> 00:38:18,970 Look at this five-foot reef shark. 707 00:38:19,040 --> 00:38:21,630 Perfect prey, I think, for a 12-foot hammerhead. 708 00:38:21,670 --> 00:38:23,330 We need blacktip sharks, 709 00:38:23,400 --> 00:38:25,170 blacknose, Caribbean reef sharks, 710 00:38:25,230 --> 00:38:26,900 we need southern stingrays. 711 00:38:26,900 --> 00:38:28,530 We caught a lemon shark now. 712 00:38:28,600 --> 00:38:31,670 That would be a perfect snack for a hammerhead. 713 00:38:31,700 --> 00:38:34,070 [narrator] Over the course of the next week, 714 00:38:34,140 --> 00:38:35,630 the team will take muscle samples 715 00:38:35,670 --> 00:38:37,770 from over 30 individual species 716 00:38:37,800 --> 00:38:40,800 of sharks and rays that are abundant in the area. 717 00:38:42,270 --> 00:38:44,700 This is absolutely gold. 718 00:38:44,770 --> 00:38:45,900 Data gold. 719 00:38:47,700 --> 00:38:49,600 [narrator] The mission comes to a close 720 00:38:49,630 --> 00:38:51,430 and all the tissue samples are sent 721 00:38:51,430 --> 00:38:53,900 to a lab in Florida for analysis. 722 00:38:57,330 --> 00:38:59,870 -[Tristan] Hey, Phil, how are you doing? -[Annie] Hey. 723 00:38:59,900 --> 00:39:01,530 We're on the edge of our seats trying 724 00:39:01,530 --> 00:39:03,400 to work out what you're gonna tell us. 725 00:39:03,430 --> 00:39:04,870 [Phil] We just got the data back 726 00:39:04,900 --> 00:39:06,330 and you are gonna be shocked 727 00:39:06,330 --> 00:39:08,330 -by what we have. -Ooh. 728 00:39:08,400 --> 00:39:10,230 [Phil] So we were expecting this hammerhead 729 00:39:10,270 --> 00:39:12,070 to have eaten a lot of stingrays. 730 00:39:12,140 --> 00:39:14,530 But in fact, less than a third of its diet 731 00:39:14,530 --> 00:39:16,430 is comprised of those southern stingrays 732 00:39:16,500 --> 00:39:17,870 -that we sampled. -[Tristan] Okay. 733 00:39:17,900 --> 00:39:19,230 What is it eating then? 734 00:39:19,270 --> 00:39:21,530 The results are surprising. 735 00:39:21,530 --> 00:39:24,430 This is definitely a shark-eating hammerhead. 736 00:39:24,500 --> 00:39:26,500 The tissue tells us that 70% 737 00:39:26,530 --> 00:39:28,330 of what this hammerhead has eaten 738 00:39:28,330 --> 00:39:29,900 -are sharks. -[Tristan] Wow. 739 00:39:29,900 --> 00:39:32,430 -So a shark-eater? -[Annie] What? 740 00:39:32,430 --> 00:39:35,530 [dramatic music playing] 741 00:39:37,430 --> 00:39:39,870 [Tristan] What Dr. Phil has initially found 742 00:39:39,900 --> 00:39:41,330 with these findings, 743 00:39:41,400 --> 00:39:42,630 it's really exciting 744 00:39:42,670 --> 00:39:44,530 and it clearly shows 745 00:39:44,600 --> 00:39:46,600 that that big female shark 746 00:39:46,630 --> 00:39:49,500 that we took the muscle sample of 747 00:39:49,530 --> 00:39:50,900 is a shark-eater. 748 00:39:53,140 --> 00:39:55,400 -That is actually really surprising. -Yeah. I always expected 749 00:39:55,430 --> 00:39:58,040 that the rays would be like right up there. 750 00:39:59,970 --> 00:40:01,970 [narrator] The diet analysis has revealed 751 00:40:02,040 --> 00:40:04,170 Andros' great hammerheads are eating 752 00:40:04,170 --> 00:40:06,070 just about every shark species 753 00:40:06,140 --> 00:40:09,070 that inhabits the island's waters. 754 00:40:09,070 --> 00:40:11,270 [man] He's working on another shark. 755 00:40:11,270 --> 00:40:12,770 [man] Holy [bleep]. 756 00:40:12,800 --> 00:40:15,170 [narrator] And not only that, they're hunting them 757 00:40:15,230 --> 00:40:17,070 in every unique habitat 758 00:40:17,070 --> 00:40:18,600 it has to offer. 759 00:40:20,900 --> 00:40:22,600 [Tristan] There are juvenile sharks 760 00:40:22,630 --> 00:40:24,400 of many different species 761 00:40:24,430 --> 00:40:26,040 year round in Andros. 762 00:40:26,070 --> 00:40:28,500 And maybe this allows great hammerheads 763 00:40:28,530 --> 00:40:30,630 to actually be resident year around 764 00:40:30,670 --> 00:40:31,870 to this system, 765 00:40:31,900 --> 00:40:33,270 which is quite novel 766 00:40:33,270 --> 00:40:34,870 for these migratory species 767 00:40:34,900 --> 00:40:37,270 that typically travel thousands of miles. 768 00:40:37,330 --> 00:40:39,170 We have a lot more work to do 769 00:40:39,170 --> 00:40:42,230 because would've suspected a very different result. 770 00:40:42,270 --> 00:40:44,070 We need to look at some of these other hammerheads 771 00:40:44,140 --> 00:40:46,140 and see if they're following a similar trend. 772 00:40:49,430 --> 00:40:51,270 [Tristan] We know that hammerheads across the world 773 00:40:51,330 --> 00:40:54,970 are probably more likely feeding on stingrays. 774 00:40:54,970 --> 00:40:57,170 They've got that big hammer-shaped head 775 00:40:57,170 --> 00:41:00,270 that's really adapted for pinning down rays. 776 00:41:00,330 --> 00:41:01,330 [Skye speaking] 777 00:41:01,400 --> 00:41:02,430 [Tristan] But we might have found 778 00:41:02,430 --> 00:41:04,140 that these hammerheads in Andros 779 00:41:04,170 --> 00:41:07,170 are actually keeping sharks in check. 780 00:41:07,230 --> 00:41:08,270 There has to be something 781 00:41:08,330 --> 00:41:09,900 that keeps those animals in check, 782 00:41:09,970 --> 00:41:11,170 because if there isn't, 783 00:41:11,170 --> 00:41:12,800 then they may overfeed 784 00:41:12,800 --> 00:41:14,530 on other small fishes 785 00:41:14,530 --> 00:41:16,430 that may impact the health 786 00:41:16,430 --> 00:41:18,270 of the rest of the system. 787 00:41:18,330 --> 00:41:20,630 Hopefully, people will see these hammerheads 788 00:41:20,670 --> 00:41:23,900 and understand that they're truly the guardian 789 00:41:23,970 --> 00:41:25,798 of these habitats and ecosystems.