It's a Shark Eat Shark World (Full Episode) | SPECIAL | Nat Geo Animals

Around the world, reports of shark-on-shark attacks are on the rise. Whoa, whoa, whoa. Hey, look at the shark trying to eat that shark. Oh, there's another one. Oh, my god. Now, off South Africa's Western Cape, a new hot spot may have emerged. The drone is in the sky. Shark looks like it's about 15 meters to your port. There's four great white sharks around this boat. This is a shark fest. A bay where white sharks are suspected of hunting other sharks. We are positive that white sharks are professional shark hunters. Can a team of scientists find hard proof that these sharks are turning on their own kind? Yes! This could hold very important information. As the hunter becomes the hunted, the very future of South Africa's white sharks is at stake. Mossel Bay, South Africa. Home to the legendary white shark, the largest predatory fish on Earth. They can grow to over 18 feet. Scientists Dr. Enrico Gennari and Lacey Williams have been studying South Africa's white sharks for over a decade. At any one time, we believe there are between 40 and 60 great white sharks In the last 10 years, white shark numbers have dropped across South Africa. Now, Mossel Bay is one of the last places you can still see them up close. And what draws them here is food. For years, it was thought that what brings the white sharks to Mossel Bay is this 650 foot long rock. It's home to over 4,000 Cape fur seals. Ambush hunters, white sharks like to surprise their prey. Hanging in the deep waters around the island, their gray backs blend into the background, making them difficult to spot from above. Seals, silhouetted at the surface, stand out in stark contrast. They hit at speeds of 20 miles per hour. These aerial assaults have made the white sharks of Mossel Bay famous across the world. But all is not as it seems. We thought that it was the seals that brought the sharks here to Mossel Bay. But the math doesn't quite add up. Adult white sharks need to eat the equivalent of one seal every three days. That would amount to 1,500 seal kills every season in Mossel Bay. But only around 150 end up as shark food. So what else is going on? We think that there's something far more interesting and exciting going on beneath the surface. Are those sharks focusing their diet on those seals, or are they eating something else? To find out, Lacey looks for clues from the air. In the right conditions, when the sun is lower in the sky and there isn't glare on the surface of the water, we can use drones to see what's going on beneath the surface. Recently, in nearby Plettenberg Bay, Lacey recorded an unexpected glimpse of what the white sharks are up against. Seals are pretty tricky to hunt. They're not as easy as you think. They're agile. They've got claws on their flippers. They've got a bite akin to a dog. So they can be dangerous. Her rare footage shows seals mob and then chase off a nine-foot white shark. It's the first time a research team has recorded seals fighting back in this way. If Mossel Bay's white sharks are facing a similar challenge, what are they eating? Our hunch is they actually might be spending more time hunting other sharks than seals. Captured on camera, reports of shark-on-shark attacks are on the rise. Get over here. Hurry up. Whoa, whoa, whoa. I can't believe he got shocked. New camera tech makes it possible. Sharks getting shocked. For amateurs across the world. Having a tough day, this guy. To record these rarely seen predation events. Yeah, another shark. Oh, look at the shark trying to eat that shark. Oh, my god. Did you get that on video? Oh, my god. Have Mossel Bay's white sharks also developed a taste for their own? High above the bay, the team set up a research base where they'll analyze their data to look for proof of shark-on-shark attacks. This is Seal Island. And you can see this is a hot spot for white shark, especially in winter, where the young of the year seals venture for the first time into the ocean. Over the last 10 years, Enrico has tagged more than 30 white sharks with tiny acoustic transmitters. Every time one passes within half a mile of a listening station, it records the date and time of each individual. It reveals a seasonal pattern to their behavior that could provide a starting point for the investigation. It's fascinating to see all of those shark tracks so densely concentrated around one hot spot. They're really focused. They're there for a reason. And it is to hunt seals. In winter, the young seals leave the island for the first time without any knowledge or experience of how to avoid predators. Many fall victim to the waiting white sharks. But in summer, everything changes. The seal are breeding and therefore not entering as much the water. And therefore, the white shark shift their attention to those three reefs here, here, and here. And those reefs are just outside the main three river mouth. With no seals around these river mouths, what's attracting the white sharks? It's really fascinating to see them go from one area in the bay to spread out to three different areas throughout the bay. Shallow estuaries are often nursery grounds for young sharks and places where smaller coastal sharks hunt. This looks like it could be our first big clue at these river mouths, right? And that is exactly where our stakeout should begin. I agree. But before their stakeout can even start, news comes in that could close down Enrico and Lacy's investigation. 240 miles from Mossel Bay, there are sightings of another deadly predator, orca. At over 22 feet, they dwarf most white sharks. Armed with three-inch long teeth, these highly intelligent mammals hunt in packs. They're one of the only predators that are a threat to white sharks. In the last eight years, orca have been responsible for a spate of gruesome attacks on South Africa's large sharks. I'm really worried because white sharks already face a lot of different threats caused by us. For Enrico and Lacy, the pressure is on. If the orca arrive in the bay, the sharks will flee. In Mossel Bay, the clock is ticking. With orca sighted down the coast, the stakeout begins. Shark scientist Lacy Williams takes up position next to the Klain Brack River. Out on the water, Enrico Gennari preps camera traps to find out what the white sharks eat when seal is off the menu. We call it BRAV, a Baited Remote Underwater Video Camera. And it's our eyes under the water without us disturbing the animals. The bait attracts all the preys that are in this area. Bye-bye. Justin, let's go to the next spot, please. Enrico deploys BRAVs at the three river mouths identified as white shark hotspots. By dropping all these BRAVs on those river mouths, we really hope to see and understand what makes them so important for great white shark. Lacy, the BRAV is deployed. With a BRAVs recording, the team turned their attention to the white sharks. Their plan? To attach a camera that will record their every move. How is it, Enrico? Drone is in the sky. And it looks like you've got one about 80 meters to your port, slowly heading your way. With eyes in the sky, Lacy guides Enrico to another white shark hotspot just off the Great Brack River. I think the shark's swimming over the reef. So it also looks like it's in a good spot. This little baby is something I'm really proud of. It's something I designed. It's a fin cam. It's a camera that is positioned and attached to the dorsal fin of the shark to give us a perfect POV of the shark. Hopefully, for the first time ever, we might be able to see a great white eating another shark, something that has never been seen before. Shark looks like it's about 15 meters to your port, slowly heading your way. Now it's up to Enrico to entice a shark to within striking range. Right there. It's about two meters. Look how beautiful it is. Coaxing a white shark into a trap is not easy. It's a camera shy shark. It's a different one. But as sharks start to surround the boat. There's a third one. Four. Enrico's chances increase. There's four great white sharks around this boat. This is a shark fest. Well done. Yes! Go, baby, go! Show us some secrets. Yes. Wow. Back at base, the footage has been retrieved from the baited camera traps. Joining Lacey to review it is research leader Dr. Neil Hammerschlag. How's it, Neil? Hey, Lace. Welcome. An international shark specialist, he's flown in from Florida. Let's start scrubbing the footage. To work on the data analysis. That'd be neat. The video reveals the river mouth, a summer white shark hotspot teems with life. Look at this, OK? We have a pajama cat shark at the bait of this bruv, OK? Swimming around, doing its thing. OK, now wait for it. Well, white shark comes in, OK? Takes a bite at the bruv. Cat shark immediately freezes, OK? Neil and Lacey spot their first clue. The cat shark appears to play dead. And what's, like, super cool is it's not even breathing. It's holding its breath. And by doing that, it's not pumping water over its gills, which would otherwise be generating a weak electrical field that the great white could pick up. It's an indication of what might be going on between the bay's white sharks and their smaller relatives. That's crazy cool. And that's a clear prey response to the presence of a predator. I've never seen footage of this kind ever before. And it's really a breakthrough point for our study. When you actually look at the behavior of the sharks that we're seeing on the videos, they act like they're scared of white sharks. And you know what runs from white sharks? White shark food. The next day brings alarming news. Definitely orcas. Oh, and there might be one further out. There might be one further out that way. With her phone, Lacey spots orca at the southern edge of Mossel Bay. Nope, nope. There's more. It's a potential disaster for the investigation. If the orca hit the bay, the white sharks will vanish, or worse, be attacked. Time is running out to get all this data, all this footage. And we really need to obtain the last pieces of this puzzle that we're trying to solve. With no time to lose, Enrico sets out early to hunt for the fin cam. OK, not too far, eh? It's right here. It's been over 12 hours since it was attached to the back of one of the bay's white sharks. Right there. But keep it short of the anchor. Luckily, they've had a lead. The shark has been spotted in the bay. Now we have the shark only 20 meters away. Loud noises usually scares animal away. But with sharks, they're very inquisitive, and they come investigate what it is. Come on, come, come, come, come. The fin cam should have automatically released, but the mechanism failed. Enrico will need to remove it from this 9-foot predator himself. It's coming right here. Come on, come on, come on. It's all or nothing. After 20 minutes, it's close enough for Enrico to attempt the rescue operation. Yeah! Enrico is finally reunited with the camera and its priceless footage. This is one of these moments that you remember forever. It's like the Oscar, and you say, I want to thank my mama, my wife, my daughter. This could be a small step for humankind, but a giant breach for the great white shark. I can't wait now to go back and download it. Hey, it says, if you find it, you get a reward. Can I get a reward? Back on shore, the team review the hard-won fin cam footage. Will it prove the white sharks are hunting their own kind? Oh, Enrico, check this out. It looks like our white shark is swimming really close to the seabed. It could be anywhere in the water column, and it's swimming along the seafloor. That's wild. It's exactly where the small inshore sharks might be found. It's definitely between reefs and sand, but really circling in that area. Oh, that's interesting. The way it's moving back and forth, it kind of looks like it's searching for something. Remember, they don't do things by chance. If it's there, spending a lot of time there at the bottom, there is a reason. Although the camera was a success, it did not capture footage of an attack. It's now the peak of the summer breeding season on Seal Island. There are fewer young seals in the water to prey on, so the white sharks must find something else to eat. Over the past six weeks, the team have recorded over 60 hours of grub footage at the Three River Mouths. Oh, that looks like a smooth hound. It's definitely a smooth hound shark. Really, this shows us all those small shark species that are there potential quick snack for a white shark. I mean, they're all bite-sized, that's for sure. And all this, again, smooth hound coming back in, photobombing. Oh, and there's a little PJ. Those reefs close to the River Mouth are packed with more sharks. I think we're starting to see a pattern here. Definitely. By far, the most common shark showing up is the smooth hound. Growing to almost six feet, they are bottom dwellers that feed on prey like crab and squid. Our evidence is starting to mount up. The fin camera and tracking data shows that our great whites are hanging out in areas just outside River Mouths in Muscle Bay. Our grub data is showing that these same areas are teeming with life, including smaller shark species and our smooth hound sharks. So when we couple all this data together, this suggests that our smooth hounds and our great whites are somehow associated with each other. Have the team discovered what the white sharks feed on at the River Mouths? If it is smooth hounds, it's a concern. They're being heavily fished all along this coast. This is really important for us to determine because the smooth hound is an endangered species, and it is highly targeted by commercial fishing. With the orca threat still present, to protect the white sharks from these fishing pressures, the team must identify their prey. To do so, Enrico turns to someone from Muscle Bay's bloody past. Hey, Brian. Hello, Enrico. Nice to see you. Brian McFarland is a shark fisherman turned conservationist. When people used to catch the great whites, this coast was the place to catch them. Like many others in the 70s and 80s, he hunted great white sharks for sport. There are people in the world that want to prove their muchoness and catch the biggest, most fearsome animal in the sea, and that being the great white. So that was their incentive. I must emphasize, I'm not proud of what I'm telling you, but if I go back 40 years, when I went out to catch a shark, I would see 20 to 30 to 40 great whites a day. Even before we even put bait in the water, we wouldn't believe it. They were always there. But, the big but, when the Jaws movie came out, that was the turning point. Everyone hated or wanted to kill a great white. And I, unfortunately, was one of them. You brought it back, hundreds of people would come onto the jetty. You'd hang the shark up, and you'd be a hero. Big photographs and things like that. Today, white shark fishing is outlawed. But the population never recovered. When I think about all these poor sharks that are killed, I really, really, really have terrible regrets. We didn't think of the future of these animals. But Brian's knowledge can now help this vulnerable species. So, in order to attract and catch white shark, how did you used to do it? We cut open their stomach. They were full of smaller sharks, different species, rays, and smaller sharks. There was virtually no seals in their stomach. And that's when we realized that the great white's primary food is a smaller shark. They were the best bait. If you had to choose one species of shark to catch a white shark, what would it be? There's not even a question. The smooth-armed shark was the great white's favorite food. With a solid lead, Enrico turns his attention to the smooth-hound sharks and some new tech. Now it's time to really step things up. We are positive. We can prove that white shark are professional shark hunters. Working with research assistant Sofu Kuoma, the team planned to fit 20 smooth hounds with a special predator tag. So far, we have been following the predator, the great white sharks, but if we really want to crack the mystery, we need to better understand its prey. Give me the tag number. Tag number is 6207. The tags will track the smooth hounds. 6207. So we just need that shark now. Awesome. But they have another exceptional function. If a smooth hound gets eaten, the predator's stomach acids will trigger the tag to emit a new signal, alerting Enrico to the kill. Then by looking at the dead afterwards, we can also look at who could have eaten that shark. This little tag could be instrumental to tell us if and when the great white sharks launched their cannibal attacks. Everyone in position, Sofu? At this time of year, the smooth hounds come together at the river mouths in large numbers to mate, an easy target for predators, like the bay's white sharks. The size of the smooth hound that we're trying to catch is between one meter and one and a half meter. This is the perfect fast food for a great white shark. OK, shark is on. He's fighting just in. No doubt. OK, put the tag in the solution. OK. The first shark they've caught is a 5-foot smooth hound. OK, it's free. Placed upside down, the shark enters a trance-like state known as tonic immobility. OK, scalpel, please. Little incision on the abdominal cavity. The team works fast to place the tag into the shark's body cavity. OK, the suture allows us to keep the tag in, but most importantly, to get the shark wound healed, and the shark will be free to become a researcher in action. End of surgery. Thank you. Now it's just time to release it. Let her do her sharky stuff, and hopefully, she won't be being eaten by a great white shark. OK. Go. There we go. There may be. Yeah. She wanted to go. Woo-hoo! Over the next two weeks, Enrico and his team tag more of the bay's smooth hound sharks. Shark on. Each one increases their chances of recording evidence. 6-2-1-1. Of a shark on shark predation. OK, definitely good. Next one. Bye-bye. There she is. Yes, nice. That is for a monster great white shark dinner. But then, their worst fears are realized. The orca arrive in Muscle Bay, and the great white killings begin. The last thing Lacey and Enrico's investigation needs is a pod of five orca. For the first time in South Africa, the detail of their highly coordinated attack is captured on camera. First, the pod singles out a white shark and chases it for more than an hour. Then, one orca delivers a fatal bite. So yesterday, we saw, we found a white shark carcass that had washed up just right here in this section on the beach. The 10-foot teenager is one of two sharks thought to have been killed. When orcas hunt white sharks, they can grab them by the pectoral fins and actually rip them apart. With surgical precision, they target the shark's fat-rich liver, ripping it clean out. It's the first recorded death of a white shark by an orca in Muscle Bay. It's a day that will live with me for the rest of my life. To see a beautiful animal torn apart in a way that only nature can do kind of renders you speechless. Obviously, in my mind, there was that dark feeling that a white shark was killed by an orca. I still remember the goosebumps. Then, knowing that something even worse was going to follow, the disappearance of all the other white sharks. And that happened in the last week. We haven't seen any white shark here in Muscle Bay. With less than 1,000 white sharks remaining, every individual is precious. The death of two takes South Africa's population one step closer to collapse. Seven weeks after the deadly orca attack, some good news. Enrico, we got two sharks. We got two sharks. Yes. There's a white shark right there. Beautiful shark. White sharks are spotted in the bay. We got two beautiful sharks around us. This is the second great white shark. We just had in about 10 minutes. And with the orca gone, they're back in abundance. Shark after shark after shark. With a window of opportunity, the team prepares to gather one final piece of evidence, tissue samples from the bay's white sharks. Now is definitely game on. We need to figure out what these sharks are really eating. When sharks eat, the fatty acids in their food leave a unique chemical signature on their muscle tissue. With careful analysis, it can be read like a food diary. We are what we eat. And the tissue samples provides us with a map. It's like looking back in what that shark has been eating for the last six months. To get consistency. All right, it's coming towards you, Enrico. You're getting within five meters to see it. Coming from your right. The sample must be taken from muscle tissue just behind the dorsal fin. Yeah, but he's moving away again. Come back. Nicely done. Let's get some tissue out here. I'm really looking forward to see what story that this sample can tell us. The samples will be sent to Neil's lab for analysis. I need to put it in the freezer quickly. Here we go. Cool. Let's get another one. Is that ice? Yeah, I see it. Yeah, got it. It's been six months since shark scientists Enrico Giannari and Lacey Williams started gathering evidence in a bid to discover whether Mausoleum Bay's white sharks are killing their own kind. It's now time for Enrico to collect the predator tag data. Once uploaded, it will reveal if any of the bay's smooth hounds have been eaten. Being able to prove with our data that smooth hound sharks are eaten by great white sharks is a key piece of evidence in our investigation. Receivers dotted across the bay track the smooth hounds' movements. And we see that they stayed within the bay. But watch now. One by one, their color is changing. That means they have been eaten. Their signal is changing. And they are in the stomach of something much bigger. 70% of our tag sharks have been eaten close to the river mouth. Unbelievable. And there's one prime suspect. Prey on a 4 and 1 1 foot shark, you need to be quite big. And this is white shark country. So white sharks are the main culprit here. Enrico's hunch is still to be confirmed. But the data takes them a step closer to proving that Mossel Bay's white sharks hunt their own kind. This is very important information. But at the same time, it's also so concerning because those small sharks are so heavily overfished. And therefore, not managing the small sharks means we're not managing the great white sharks. OK, let's anchor up. The team had set out to prove that instead of seals, Mossel Bay's white sharks hunt and kill smaller sharks. Now, research leader Neil Hammerschlag is back with what they hope is the decisive evidence, the results of the white shark tissue samples. Lacey and Enrico. Hi, Neil. Welcome. Hi, Neil. How are you guys? Welcome. Buddy. All right, cool. I've got, hopefully, some good news to show you. Show me what you got. When sharks eat, fatty acid markers in their food leave a unique chemical imprint on their muscle tissue. By analyzing the relative levels of each marker, a meaningful pattern emerges. These are results from the first samples of muscle tissue analysis from any Mossel Bay sharks. What we're seeing is their muscle is dominated by fatty acids, which you would find associated with other sharks. This is great. Yeah, this is crazy. What you're looking at here is the first evidence that the sharks in Mossel Bay, the majority of their diet is other sharks. But that's not all the data reveals. Two markers associated with bottom dwelling and estuarine prey are showing up, exactly as you'd expect if the white sharks were feeding on sharks from Mossel Bay's river mounds. This is proof. Yeah, absolutely. Now, if you take this one step further and compare what we found here with other locations. When compared to other white shark hotspots, like Australia, it reveals that Mossel Bay's white sharks have less than half the level of fatty acid markers associated with seals. What I really didn't have an idea is what it would show is just like kind of the magnitude that, in fact, the sharks' whole chemical composition of their actual tissue suggests that what they're actually integrating in the tissues is based on a diet that's predominantly other sharks. I mean, that's amazing. This blows a hole in the longstanding theory that Mossel Bay's white sharks are aerial hunters who predominantly eat seals. The findings are vital for the long-term survival of these sharks. Due to heavy fishing, their reliance on smaller sharks could come at a deadly cost. We can't do anything about the orcas, but we can do something to protect the important species like this mudhound shark as prey for the predator, the great white shark. So if you are what you eat, this is the first evidence that the Mossel Bay white shark could really be shark hunters. Absolutely, without a doubt. I literally almost fell over when I saw that the results indicate that huge amount relying on other sharks and fish. At a scale I had no idea, especially from a shark in any area where there's a seal colony. We didn't get the kill on camera, but that was going to be our cherry on top. Because in looking for that shot, we learned a lot more. After all the evidence we collected, the fisherman tails, the braves, the fin cams, the tissue sampling, we can definitely say that out there is a shark eats shark world.