Tagging Giant Tiger Sharks - Inside Bermuda’s Shark Conservation Mission

This is Dr. Neil Burney. He lives in Bermuda, a stunning Atlantic island 640 miles east of North Carolina, USA. He spent the last 30 years practicing veterinary medicine, but now he's transferring his veterinary skills to help save, protect, and learn more about the incredible marine life of Bermuda's ocean. Alongside his dedicated ocean vet team are a number of scientists, marine biologists, and specialist master divers, helping to perform a number of unique and dangerous procedures in a bid to safeguard critically important marine species. Together, the team will be fitting satellite tags to huge tiger sharks, saving precious green turtles, dissecting giant blue marlin, and obtaining unique toxin samples from 45-ton migrating humpback whales. My knees are like jello. Yes, man. This is Bermuda, home to Dr. Neil Burney, the ocean vet. The tiger shark is one of the world's most powerful predators. Millions of years of evolution have seen this beautiful animal rise close to the top of the oceanic food chain, but this stature has come at a price. Local and international fishermen target this species, among others, for their fins and liver oil. Consequently, the tiger shark is now classified as near threatened. You're just so poor if I start to go. The ocean vet team are coming to the end of an eight-year tiger shark research project. Little was known about this impressive predator. The project was established to tag and collect critical migratory data while learning more about this animal's behavior. These animals are absolutely spectacular. They're a hydrodynamic marvel and beautiful to watch. Neil and his team's research is helping local and international authorities establish shark protection policies. I got to be honest with you. I'm calling this possibly the biggest shark we've ever had. This thing is monstrous. In this episode, Neil and the crew struggle with an 800-pound tiger shark while attempting to fit its satellite tracking computer. Neil's unique set of veterinary skills are tested and the team's experience pushed to the limit. Go, go, go, go, go, go, go, go, go, go, go. Under the water, the team risk their lives to learn more about tiger shark behavior while attempting to dispel the notion that these animals are mindless man-eaters. Okay, I'll pull it out from under. The final $6,000 satellite tag will provide the data needed for the government of Bermuda to establish a comprehensive shark conservation policy, the first of its kind in Bermuda's long history. As Neil and the team prepares to embark on this epic adventure, Neil carefully checks the equipment needed to secure a huge tiger shark to the side of the boat. This is a sling in which we suspend our large tiger shark when we get into the side of the boat. It has to be adjustable both ways so that we can roll him rotationally to position his dorsal fin for drilling. We're going to take a measurement. Siri's marine biologist, Choy Aming, has been studying these sharks with Neil for over the last eight years and has made some interesting observations on their behavior in the wild. Now, obviously, we were cautious when we first jumped in, just didn't have any idea what to expect. But over time, we've definitely seen that they're not the mindless eating machines that you think they are. In fact, when we're in the water, if you hold your ground and assert some dominance in the water column, not aggressively towards the animal, but you just hold your ground like you're a large predator, they'll keep their ground. And we've stayed in the water well over an hour on a couple of occasions with multiple tiger sharks. So it just goes to show that once you understand the psychology of the animal, you can do a lot more than you think. Swimming with tiger sharks is dangerous. The team have had years of experience developing a unique understanding of shark behavior. Neil and Choi believe that by sharing their incredible interactions, they can change people's perception of tiger sharks and sharks in general. As always, Neil and Choi are supported by the rest of the Ocean Vet crew. Andrew Kirkpatrick is the underwater cameraman and doubles as underwater support during veterinary procedures. Dylan Ward and Neil's son, Oscar Deuss, are the shark safety divers. Together, they ensure the safety of the team. The tiger shark tagging location is a 12-mile burn southwest of Bermuda to Challenger Bank. This seamount is one of two underwater volcanoes. It rises up from well over 2,000 feet and comes close to the surface at just under 180 feet. Before the team reach Challenger Bank, their journey is interrupted by something rather special. So as we're traveling through the deep oceans, we've come across a pod, a bottlenose dolphin, and they're actually riding the bow with us. There's about 30 of them. We're going to try and see if we can get in the water and swim with them. These bottlenose dolphin are actually a specialized subspecies of deep diving dolphin. The dive patterns of these mammals correlate with vertical nightly migrations to over 6,500 feet. They hunt for prey on the steep-sided Bermuda pedestal. The opportunity to interact with such a subspecies is extremely rare. As always, Neil manages to do so in his own unique style. All right, so it's the first time I've used this fin in angler. This is Lunaset Pro by Tenchia Miller. This thing makes you swim like a dolphin, and I swear that dolphin, we think he was a big male, came in as if to say, what in heaven is that thing? Let me take a closer look. And he came right up, and then we swam across each other, and we swam together. It was just wicked. It was exactly what I wanted to do with this fin. Humpbacks next year, this is going to be the deal. With spirits high, the team switch gear back to tiger sharks. Choy is preparing the chump. So you can see Dylan and I here at the chump table, and basically we're making chump for the sharks. So what we have down here is a soup of blood, guts, fish, just general nastiness. Now, the way we get a shark coming up is to actually attract them by sense of smell. Sharks have a fantastic sense of smell overall. Most sharks can detect about one drop of blood in a million drops of seawater. These animals track scent lines for hundreds of miles. In the wild, these lines usually direct the sharks to a feeding opportunity, more often than not, a bait ball. Neil uses a slightly different payoff for when the sharks arrive. So this is a large blue marlin head. We get these from the sport fishing fleet, and the body of the fish hopefully gets used for some research. But the head becomes the centerpiece of our chump line. This is what the tiger sharks love to chew on, and when they're playing with this, they're less focused on us while we're swimming with them. So, Troy, let's get this in the water. Yeah. Three, two, one, go! Once the head is in position, Neil jumps in and heads out to the marlin head. Tiger sharks are already in the area attracted to the chump, but they're keeping their distance. To bring the sharks closer, Neil starts to scrape the marlin head with a knife. The sound travels through the water column and is picked up by the shark's lateral lines, a sensory system located along the side of the shark that converts movement and vibration into electrical impulse signals. Moments later, Neil spots a large tiger shark rising up from the deep. So while I was scraping the head, one of the sharks did come up and say hello, but he headed back down to the deep. So now I'm going to send this little cue toy down for him to play with and then hopefully bring him up to the surface where we can get in the water, swim and observe the behavior of these animals up close. Neil's tried and tested methods have now brought multiple sharks right up to the marlin head. Their interest in the bait is now at the critical level. It's only once the sharks are engaged with the bait like this that Neil and Troy feel happy to enter the water. Okay, so in the last few moments, we've had three tiger sharks turn up in our chum line. So we're getting ready to get in the water and swim with them. Why would we want to get in the water and swim with three large tiger sharks? We want to observe their behavior, how they interact with one another. Very little research has been done on this and we aim to increase that amount of knowledge. People think, is it dangerous? Well, if you appear to be dead, dying or dumb, then you deserve to be on the tiger shark's menu, but we're going to act like other sharks. We're going to swim with them if they swim with us. We're going to show you that they're not to be feared, that they're to be respected. We want you to like these fish, so you don't kill these fish. It's clear from the outset why Neil and Troy enter the water during this period of high activity. Over the years, they have learned that the bait draws the attention of the sharks away from themselves. Where most people would consider this to be the worst time to jump in, it is in fact by far the best. The animal's inquisitive nature allows Troy the opportunity to take some photographs. These will be cross-referenced against Neil and Troy's database of shark photos and enable the team to see which individuals are back in Bermuda from their oceanic migrations. Well, that was amazing. Four large tiger sharks. One of them's obviously been hooked by somebody else, had a long leader and some spectra line coming off him. But what an amazing experience to see these sharks swimming close to us and to interact with not only us, but with each other. Just amazing. Over years of observation, the Ocean Vet team have been able to unwrap some of the secrets of tiger sharks. These animals do show interest in Neil and Troy, but they also carefully watch one another. The animals make behavioral decisions based on the size and actions of other sharks in the area. As one feeds, others patiently wait their turn. By understanding this social order, the sharks accept Neil and Troy as other predators, enabling them to swim with the tigers in relative safety. Back on board, the team are reminded of how quickly things can go seriously wrong. Break the lower unit off, Jason! It's a wrap, it's a wrap. Bring it up, bring it up. There's no way you can bring it up. Starboard engine, trim up, please. Starboard engine, trim it right up quick as you can. Go, go, go, go, go, go, go, go, go, go, go, go. Yeah, all right. The shark just took the buoy right under our starboard engine. He's in danger of breaking the lower unit off. The shark swims around and heads straight back towards Troy. Unbelievably, he jumps in. In this slow motion replay, you can just make out Troy's foot pushing the shark free of the engine. Troy is now some distance from the back of the boat. Disorientated and with no safety team, he's in danger. Sensing an opportunity, other sharks start to move towards Troy, following him right back to the boat, where he eventually manages to climb to safety. That was a big nine or ten foot shark just dominating the scene with three others following in suit, almost bumping off each other. That was a fantastic encounter. So after a couple of hours of multiple tigers chewing on it, that 100 pound marlin head has been reduced to this. Probably about eight pounds in weight. They've almost torn the chain right the way through the skull and they also chewed through our rope and have nearly chewed through our 2,000 pound stainless steel cable. With so much shark activity, the team decide to push forward. Next, they'll attempt to catch one of these huge sharks to fit the final $6,000 satellite tracking computer. Neil lowers a single steel fishing line with a baited circle hook. It's not long before a tiger shark takes the bait. I think somebody's playing with this one. Oh yeah, here we go. Tiger shark on! There is a serious risk of being pulled overboard when fighting such a huge fish. Neil uses a body harness to support his back and Troy stands by to assist with additional weight. Basically, I'm just bracing Neil. What happens is he's actually come from the back of the boat, so he's higher up on the step here and obviously the center of gravity is a little bit higher and also the shark's getting close to the boat so he's getting a little more squirrely. Under the water, Kirkpatrick is watching the shark as it gets closer to the boat. The line has caught the shark on its tail and rolled him onto his back. The shark is now in tonic immobility, a trance-like state that sharks experience when upside down. We believe this fish may be tail wrapped. As he was running straight away from the boat, the leader is caught around his tail, so we're bringing him in backwards. Troy spots the shark break the surface. As it does, it triggers the shark's senses and suddenly rolls over and powers towards Dylan. Okay, so this fish is taking a powerful runoff into the distance right now. That's a serious run, man. You know what, I didn't check this either. This is the rod that I lent to somebody else. With the added concern that the equipment isn't in the best condition, Neil starts to regain some ground on the tiger shark. Unbeknown to the team, this tiger shark is the biggest shark they've ever encountered in Bermuda waters. You're going to have to loose the anchor briefly and let it go over my head. Is it good? This is a big tiger shark. You can see what we mean with the tail wrap. He gets it on his tail and then comes in in this position. And you can see the huge claspers. It's a big boy. The first and most important task is to immobilize the shark's power using a strong but soft tail rope. Good job, buddy. Neil and his team work quickly to rotate the shark so they can slide the harness around the animal and secure it to the side of the boat. But with a shark of this size, that's easier said than done. I got to be honest with you, I'm calling this possibly the biggest shark we've ever had. This thing is monstrous. I can tell you the weight when we measure it, but this is huge. With the shark now safe and secure, Neil and Troy can begin the tagging procedure. So we've assessed our shark. We think he's about 900 pounds. One of our largest tiger sharks that we have here in Bermuda. So we're going to fit him with our three-battery extended life spot five tag. It's a quite big tag. It's often used on the great whites, but it's not too big for this fish. He's a monster. These tags collect migratory data. Over the last eight years, a number of tiger sharks have been tracked all over the Atlantic Ocean. These tracks have revealed Bermuda to be a key habitat showing individuals returning year on year. This is the crucial information the team need to help protect this species in Bermuda. Back on the boat, Neil and Troy have the last sat tag in place. Well, basically, we're putting the satellite tag as high on the fin as possible so that the antenna reaches up. We're bolting through. The tag's on one side. We have a washer and a lock nut. And we have plastic bolts so that it doesn't rust in the animal. Just all thinking about animal safety. And we'll snip them off and make it as streamlined as possible so it affects his swimming at a minimum. Yeah, this is a huge fish. To secure these tags, Neil has drilled small holes through the animal's dorsal fin. This looks distressing, but sharks have very few nerve endings in this part of their body. It is a relatively painless procedure and a very small price for this one shark to pay for the benefit of its entire species. I just think it's tragic how many sharks are being killed. Needlessly for their fins, for game fish, for sport, just for putting their teeth on a wall. And we don't understand enough about the migratory patterns of these fish. And this study is going to allow us to learn so much more about how far these fish travel and the fact that they are truly international migrants. So you can see the tag nicely right at the dorsal fin, right at the top. So when he comes to the surface, that antenna is going to come out. This point of the shark's tag will dry and that will tell it to transmit. I'm going to trim away the surplus plastic, being careful not to throw it in the ocean where it would add to the plastic pollution that we're already dealing with. The shark has been in Neil and Choi's care for just over 10 minutes, well under the 20 minute release target. Now the tag is in place, Choi is able to move in and collect the information required to complete the data package. Excellent. Cool, 10 foot 1. All right, so it was 10 foot 1 overall, which puts it in about the 750 pound range in terms of sharks. And to the end of the tail, it was about 12 foot 4. 10 foot sharks are usually in the area of about 15 years old. So this guy's been around for a while. Judging by the size of his claspers, I'm sure he's reproducing. The team are now preparing for the shark's release. Neil's veterinary skills are key to this final step. The shark is tired and will need Neil's assistance to swim free. Over the course of this project, Neil and the team have successfully released all their sharks. But as this is the last one, the pressure is on to get it right. So I'm just going to check his nictitating membrane to make sure he's vigorous and I'm going to look at how he's breathing. The nictitating membrane test is a simple reflex examination. The shark's protective eye cover closes upon Neil's gentle touch. This is a good indication of how alert the shark is and enables Neil to predict how the shark will behave once the straps are released. Nictitating membrane is good. Came straight over his eye. Neil then checks to see if the shark has flow over its gills. Again, this indicates how alert the shark will be when it's set free. And he's gulping water, so he looks good. I'm happy. These fish are so vital to the marine ecosystem. I'm delighted that we've been able to capture this guy, have him in good shape, and we're going to let him go. I'm going to wish him well on his journey and hopefully we're going to change the impression that the only good shark is a dead shark. Neil carefully uses large bolt cutters to remove the hook. There is inevitably a small amount of blood, but nothing that won't heal quickly. Hook is clear. All right. Finally, they release the sling. Neil takes hold of the shark and begins to swim this massive predator away from the boat and back down into the ocean. Since the filming of this project, the Bermuda Department of Fisheries has received a comprehensive map of over 100 tiger shark migrations. As a result, the Department of Fisheries is developing its first comprehensive tiger shark conservation strategy, a policy that will hopefully protect all of Bermuda's sharks throughout the island's 200 mile exclusive economic zone. This shark named Andy is again free to roam the open ocean. That fish was a bit slow to start. I gave him a push for about 20 meters and then I could feel him start to kick and then he started to kick away and I actually went down with him and he decided no. He wanted to come back up. He came back up and swam away just at the surface. Some tiger sharks like to cruise the surface. This one did. Next time on Ocean Vet, Neil and the team delve deep into the world of the mighty blue marlin. After hours at sea on a mission to protect this species, they successfully place the first of many satellite tags. That's it. The tag is in. These tags are deployed in this fish. Back on land, they receive a massive blue marlin from the Marlin World Cup and prepare to perform the first ever televised dissection of an Atlantic blue marlin. So here's the swim bladder. We can actually remove it from the fish. The team's goal is to reveal the anatomical secrets of this remarkable ocean giant.