Why California’s Red Triangle Sees So Many Great White Attacks — SLICE EARTH — FULL DOC

[00:00:00] Speaker 1: The Great White Shark, it can top out two tons in weight and 21 feet in length with up to 3,000 serrated teeth in its lifetime. It's one of the planet's ultimate alpha predators prowling the oceans around the world from South Africa to the Mediterranean to Australia. But there's one relatively small location in the United States that takes credit for over half of all the documented white shark attacks on humans. Why do they attack and why here? The answers lie in this place of beauty and fear, a place known as the Red Triangle. Stretching from California's Monterey Bay, 135 miles north to Bodega Bay, and then out west, 30 miles to the Farallon Islands, the Red Triangle is a wondrous habitat teeming with biodiversity on land, in the air, and in the sea. This spectacular coastline also attracts humans in pursuit of recreational sports. Over the last 10 years, three out of four great white attack victims in California have been surfers. If you're surfing in the Red Triangle, you'll beware. The search for the perfect wave can lead to a face-off with the perfect predator. October 19, 2005, 20-year-old Megan Halivay and her boyfriend Johnny hit the beach at Salmon Creek, near the small fishing village of Bodega Bay. On that day, the weather is calm, the water glassy, and the waves cresting at 10 feet. [00:02:09] Speaker 2: We just hiked down the beach because we saw three of our friends that were out in the water down there. It's really good, better than anywhere else. [00:02:18] Speaker 1: They paddle out 200 yards to join a pack of surfers, but Megan decides to paddle out another 20 feet. [00:02:35] Speaker 2: I was sitting a little bit north of the pack just because there was a wave there I liked better than the wave they were surfing. I was alone sitting there and I started to get just like an eerie feeling. Almost like warm tingles in my spine. Right as I took one stroke in the water, the shark just came out of the water, hit me. [00:03:13] Speaker 1: A massive great white shark sinks its teeth into Megan's thigh. One wrong move and she'll lose [00:03:20] Speaker 2: her leg or worse. I was just pushing myself away from it. Almost feeling like I was pushing down on it, but it was only, I couldn't move that I couldn't do anything. The shark lets go, [00:03:33] Speaker 1: but Megan's not out of danger. She screams for help, attracting the attention of Britt Horn, a lifeguard surfing on his day off. [00:03:43] Speaker 3: I turned, saw the shark's fin. I knew it was a really big shark just from the size of the fin. It looked to be over two foot, maybe three foot tall, huge triangle. [00:03:54] Speaker 2: The shark had rolled onto its side and its whole pectoral fin came out looking like elephant ears, huge. [00:04:07] Speaker 1: Despite their fears, Britt, Megan's boyfriend Johnny and other nearby surfers [00:04:13] Speaker 3: thrashed through the waves. As soon as I saw the shark hit Megan and started paddling that direction, I was afraid for myself and the other surfers. I had no idea whether it was going to hit me or any of [00:04:26] Speaker 1: the other guys in the water. With the shark submerged, Megan's in shock. Would it attack again? [00:04:33] Speaker 2: I reached my hand out and the next thing I remember, I was coming up from underneath the water and I just grabbed onto Johnny's back and they made a circle around me and we all paddled in together. [00:04:46] Speaker 3: My whole thing was trying to keep everybody calm, staying close to Megan. [00:04:52] Speaker 1: Back on shore, Megan discovers the severity of the injuries to her leg. [00:04:57] Speaker 2: I tried to put my feet down and my whole leg just gave out and before I could fall, they just like grabbed me and pulled me up the beach. [00:05:06] Speaker 3: At that point, my main concern was just keeping Megan's level of consciousness up and alert and not letting her start to spin down and go into shock. [00:05:22] Speaker 1: The Bodega Bay Fire Department paramedics race to the scene. A helicopter transports her to the hospital where doctors treat her injuries. The shark bit deep into her right leg from her calf to her upper thigh. Based on the bite diameter of 19 inches and the teeth's inner spacing of two and a half inches in Megan's surfboard, experts estimate this great white is between 18 and 19 feet in length and over four thousand pounds, two tons. [00:05:55] Speaker 2: And then you can see the whole thing goes from here all the way down, all the way down to my calf. And that is the span of actually just the first 12 teeth of the shark's mouth. [00:06:16] Speaker 1: The jaws of great whites are phenomenal. Their colossal mulls are lined with several rows of teeth. A great white can have up to 3,000 teeth in its lifetime. When it loses a tooth, another one moves forward. The upper teeth are serrated and sharp, perfect for slicing through flesh. The lower teeth are narrow and latch onto the prey, holding it in place. [00:06:42] Speaker 4: When we look closely at a white shark tooth, we can see that it's this beautiful dagger shaped, serrated on both edges and like an isosceles triangle. That is one of the unique things about a white shark tooth. That's how it's got its name, Carcharodon carcarius, ragged tooth. [00:07:12] Speaker 1: The brain of a great white is tiny compared to a human's. But they've had millions of years to perfect their deadly craft. Even in the womb, great whites are equipped with razor sharp teeth. [00:07:23] Speaker 4: It's really quite a remarkable fish. This is at birth. This is a 60, 70-pound specimen. And imagine, coming out of the female, what this must feel like. This is a very capable hunter at birth. In fact, some of them probably have eaten their siblings in utero. It's a strange behavior that this shark and other sharks have, whereby only the largest and most successful predatory juvenile will come out of the uterus. [00:08:02] Speaker 1: The way Megan was attacked resembles how white sharks attack elephant seals, typically with a lethal blow from behind and below. They attempt to immobilize their prey with a bite to their hindquarters and wait for it to bleed to death before returning to feed. Some scientists call this strategy bite and spit. [00:08:23] Speaker 4: It's looking up, looking for the silhouette of a seal or a sea lion. Sees it, mugs it, bites it, spits it out. Attempts to so severely immobilize it that it then can eat it at leisure. Now if its victim is a seal or sea lion, its normal victim, it bites and spits and waits for it to exsanguinate, bleed to death, so then it can eat it at leisure, without having its eyes gouged by the flipper nails of these pinniped seals and sea lions. [00:08:54] Speaker 5: The predator at the bottom sees very well the prey on top, particularly if there's backlighting. Not only that, he or she, the shark, has a long run to gain speed so that the impact of the attack is even greater. [00:09:12] Speaker 1: The attack technique catches the prey off guard. The seal, equipped with sharp teeth and flipper claws, will fight back, attempting to injure the shark in its most vulnerable spot. [00:09:24] Speaker 4: They don't risk injury to their eyes. A white shark that's had its eyes injured is out of business. It can no longer find its prey. [00:09:40] Speaker 1: Despite the experience, for Megan, the lure of the surf is stronger than the fear of another attack. [00:09:50] Speaker 2: At the beginning, lots of panic attacks, freaking out, thinking sharks were after me. A year later, I'm surfing Salmon Creek again. [00:10:10] Speaker 1: Megan has survived, but this attack raises many questions. Why are so many surfers attacked here, in the Red Triangle? The answer may have to do with the shark's preferred natural prey, its primary food source. The Red Triangle is an ideal habitat for pinnipeds: sea lions, harbor seals, and elephant seals. In fact, the three corners of the triangle, Monterey Bay to the south, Bodega Bay to the north, and the Farallon Islands to the west, are on or near important breeding grounds: rookeries. The southern coasts of Africa and Australia also harbor significant pinniped rookeries. All these regions are predatory crossroads for the great white shark and its preferred prey. For years, humans hunted seals along the California coast, and it nearly drove the seal population to extinction. But thanks to the Marine Mammal Protection Act of 1972, seals have made a comeback, turning this major seal breeding ground into a hunting ground for great whites. [00:11:24] Speaker 5: In this part of the world, this is central California, elephant seals and harbor seals tend to be preferred prey. That's based on what you find in the stomachs of sharks. [00:11:39] Speaker 1: In the red triangle, scientists are investigating in detail the migratory behavior of elephant seals. And they're exploring whether great whites are stalking them in the deep ocean, or primarily hovering around coastal rookeries. By tagging and tracking elephant seals, scientists have made some remarkable discoveries. In this case, elephant seal males migrate north toward the Aleutians, a chain of islands off the Alaskan coast, while females go to the open ocean in the northeast Pacific to feed primarily on squid. And the great whites. It appears that they do not follow. The precise path for all great whites is still a mystery. But in the fall, when elephant seals return from foraging and begin to breed, the great whites also return. In the red triangle, seal rookeries mark the most hazardous zones. But the entire region is unpredictable. Even areas that seem safe can suddenly erupt into deadly encounters. August 15, 2004. Randall Frye and Clifford Zimmerman are diving for abalone at a cove north of the red triangle, near Fort Bragg. For Clifford, it's the perfect day for diving. [00:13:11] Speaker 6: The ocean was flat, calm. It was a beautiful day. When we got up to this cove that we like to keep a cell of cove, we decided, well, it's such a beautiful afternoon, we'll jump in the water. [00:13:30] Speaker 1: Abalone diving can be a dangerous sport. In this region, divers free dive for abalone, as far down as 50 feet deep. They don't use scuba tanks. The divers will stay down as long as they can hold their breath. For experienced divers, it's up to a minute. But it's a dangerous underwater realm. Some get knocked against the jagged rocks by waves. Others get swept out to sea by unexpected riptides. But Randall Frye and Clifford Zimmerman are experienced abalone divers. And on this calm, clear day, danger seems far away. [00:14:15] Speaker 6: Probably about 20 minutes into the dive, Randy swam up to me and laughed at me because my mask was foggy. And then he asked, where are these big abs you get up here? I do get some pretty good sized abalone in there. And I said, not too seriously, right below me. [00:14:36] Speaker 1: As Clifford treads water, Randall dives down below. Almost immediately, Clifford senses danger. [00:14:45] Speaker 6: So I turned around and looked down at the bottom, what I could see of it. Then I felt some enormous motion in the water. I turned and looked. I thought it was a whale. It was huge. When it passed in the water, it was just pure red. I want to get out of here. I want to get to the boat. I was swimming to the boat. I was sure there was a real good opportunity that I'm going to get it too. That's what I was thinking. So when you get to the boat, you have this instant feeling of, well, we got over this hump. Clifford's safe, but Randall has yet to surface. I just couldn't believe what had transpired. And I looked out over the water and it was just like nothing had happened. There was no more blood. Just as calm as could be. Like nothing, nothing had happened. I grabbed the radio, started doing a May day. We'd had a shark attack. [00:16:01] Speaker 7: Respond code three, possible shark attack. [00:16:04] Speaker 1: Mendocino Sheriff's deputies and the Coast Guard arrive on the scene. But they can't find Randall and dusk is setting in. The next morning, the search resumes near Kibisilla Rock on the Mendocino Coast, where rescuers spot something 15 feet below the surface. [00:16:28] Speaker 7: I was notified of the alleged shark bite. We got there about eight something in the morning, eight, nine o'clock, and the water was clear. It was calm, a perfect little cove to go diving in. And we could see the person on the bottom very clearly. [00:16:48] Speaker 8: We were able to see the body about 15 to 20 feet down. And we anchored our boat up so then we could get a steady shot. And we threw a grapinole hook over and we were able to hook him onto his weight belt. [00:17:00] Speaker 1: The U.S. Coast Guard lifts Randall's body to the surface. Immediately, it's clear how the shark took his life. He was decapitated. [00:17:12] Speaker 7: As they were pulling it up, they noticed that the head was still attached to the suit. The dive hood was still attached, but once gravity got involved out of the water, the head fell back into the water. It was discovered that the shark bite was up from about shoulder to shoulder, and later determined to be about a foot and a half a bite diameter. [00:17:38] Speaker 1: Most people survive shark attacks. Why was this attack lethal? And why did the shark attack here? Perhaps it was a case of mistaken identity. Some believe that sharks have poor eyesight, relying on other senses to detect their prey. It could be that this great white mistook Randall as a seal or sea lion. Scientists are discovering evidence that great whites have a highly developed sense of sight. These sharks have a rod and cone ratio of four to one. Humans have a rod and cone ratio of 20 to one. This means that while great whites have a less developed nocturnal vision, their ability to see color and detail is better than humans. With such highly developed eyesight, great whites are efficient in discerning visual predators. [00:18:32] Speaker 9: There has been some studies done on shape that have been done with decoys. And we have found that shapes that are closest to pinnipeds with that size, perhaps with something that might look like flippers coming off the back or off the sides, are more opt to actually get predated upon or investigated by the shark. So most likely sharks are visual predators and they're looking for those shapes which are silhouetted at the surface. [00:19:04] Speaker 1: Randall's diving location near Fort Bragg and the mouth of the Neuer River may provide an explanation for this attack and the high number of attacks in the Red Triangle. Throughout the region, there are numerous vital rivers flowing into the ocean. In the months leading up to the spawning season, these rivers attract salmon and steelhead trout. They in turn attract seals and sea lions and ultimately great whites. These months when the fish gather at the riverheads, July through October, overlap with the peak season for great white attacks. These areas are feeding hot spots for the alpha predator, the great white and its prey. A familiar shape, a sudden movement, the wrong place at the wrong time. The cause will never be known. Unfortunately for Randall Frye, there was no way to escape. [00:20:05] Speaker 6: This was just a snap, bang. It wasn't food, it was just a mistake. But an animal that size when he makes a mistake is pretty hard on. It's pretty hard on the person that he made a mistake on. [00:20:24] Speaker 1: With this region rich in food, scientists want to know if great whites ever migrate outside of the Red Triangle. At places like Año Nuevo Island in the southern region of the Red Triangle, scientists tag great white sharks to track their migratory patterns and diving depths to gain greater insight into their behavior. [00:20:45] Speaker 10: Archiving information internally, storing information in terms of global position, depth position in the water column, ambient water temperature, things like this. [00:20:55] Speaker 1: This high-tech tag releases itself from the shark after several months and floats to the surface, where it transmits stored data through satellite technology to laboratory computers, revealing the great whites every move, even outside of the Red Triangle. And what scientists discover shocks them. [00:21:15] Speaker 10: The conventional wisdom had it that white sharks were neuretic coastal animals traveling up and down the coast. Once having put on these archival satellite transmitters, it became apparent that these sharks were actually open ocean, deep sea pelagic sharks. [00:21:31] Speaker 1: This new research is revealing the most surprising migration of all. Something's attracting great whites to an open area in the Pacific, between Baja California and Hawaii, especially in the spring months. The shark researchers at top, an acronym for tagging of Pacific pelagics, call it the white shark cafe. But what's attracting them there is still a mystery. They're not following elephant seals out there. It appears something else is drawing them. [00:22:04] Speaker 5: When animals are migrating, they are usually going from feeding to breeding or vice versa. If we know the sharks are feeding while they're here, it suggests that they are migrating in order to breed. [00:22:18] Speaker 1: The breeding behavior of great whites is still under investigation. And not enough is known to make a correlation between shark breeding season and the number of attacks on humans. Still, the white shark cafe may someday provide more insight into great white behavior. For now, it does point out one important fact. Great whites may leave the red triangle, but they inevitably return. Great white sharks troll the waters of the red triangle, looking for their natural prey. How they stalk and ultimately attack reveals a rare look at a surprising great white behavior and why they might attack humans. Point Lobos, California, June 30, 1995. Marco Flagg, an electronics engineer who specializes in ocean exploration equipment, takes one of his company's designs for a test. It's called the dive tracker. [00:23:25] Speaker 11: The dive tracker is a brick-shaped instrument that combines both navigation functions for a diver, as well as communication and dive computing functions. [00:23:40] Speaker 1: His dive begins with good underwater visibility. [00:23:45] Speaker 11: I was on my way out, you know, sort of slowly descending and going down at a slight angle. And I was now at a depth of maybe 40 feet. and I noticed something. And I looked to my right. And there I saw this huge tail fin, almost as tall as I am. And maybe one third of the body of the animal. And that was such an unexpected sight. At first I thought, what is that? And I thought, is that a giant tuna? No, you know. And then I said, oh wow, that's a great white shark. And it was just kind of going past, very quiet, you know, not a sound and just disappearing. And I thought to myself, and then I said, you know, I really should turn around and warn my buddies that there's a big shark in the area. I again noticed something and I looked to my left. And there I just see this huge circle of teeth. And the next thing I knew, it just clamped around. [00:25:06] Speaker 1: The great white grips Marco by his torso. With a massive bite pressure, it could easily kill him. [00:25:13] Speaker 11: So I had a lot of pressure on my body, maybe two, three seconds, and then it was gone, you know. And now I felt a lot of pain here on my stomach and on my leg. [00:25:29] Speaker 1: Stunned by the attack, Marco has no idea how badly he's hurt. Anxiously, he scrambles back to the surface. [00:25:39] Speaker 11: I took the scuba gear off, got into the boat, and my scuba gear now drifted away, you know. So I just instinctively grabbed it because you don't want it to disappear. And so I grabbed it and fell back into the water. And I said, oh man, if it now comes back and gets me, that would have been my last stupid mistake. [00:26:05] Speaker 1: Marco's safe, but his two dive companions, Steve and Marcy, are still underwater. Unaware that in the water with them, there's a massive great white. Marco revs the engine, the sign that something's wrong. Steve and Marcy hear the engine, swim to the surface, and climb aboard. As the boat races back to shore, Marco, still in his wetsuit, feels the flare-up of pain. But when the medics arrive, they're shocked to see Marco's condition. He has hardly any marks, just small punctures and bruising. [00:26:46] Speaker 11: It was a bit of a mystery as to what had happened, you know. But I still had a lot of pain in my abdomen, and then the next day it became clear what happened. One of my buddies brought in my dive computer, and there on the dive computer were bite marks of the shark, and the scuba tank had marks on it. So it turned out that I got sandwiched between the metal on my stomach and the metal on my back. [00:27:13] Speaker 1: Marco's bite wound shows punctures on the long side of the arm, across his abdomen, and on his leg. [00:27:20] Speaker 11: The doctor told me that if it hadn't been for these two devices, it would have killed me. [00:27:34] Speaker 1: Why did the great white attack Marco, only to release him? It turns out that great whites are remarkably picky eaters, interested in only the most nutrition rich foods. If there's not enough fat in the prey, then for the shark, it's not worth the energy it would take to kill and digest. [00:27:53] Speaker 12: The higher the fat content of the prey, when we speak of white sharks, the more energy the shark can obtain. That will provide the shark with a lot of future nutrition that it will need in order to carry out its metabolism and its daily functions. [00:28:12] Speaker 1: Many shark experts now believe that great whites are curious about humans. They may be testing us by tasting us to see how our fat content measures up to seals and other pinnipeds. They're mouths are lined with taste buds and their sense of smell is aided by tiny organs called lamellae behind their nostrils. Some sharks are so sensitive that they can determine if there's a single drop of blood in 25 gallons of water. Although it's still a theory, some scientists believe that the shark's sense of taste is so highly developed, it can determine right away if its prey will provide the caloric energy it needs to survive. [00:28:56] Speaker 12: Humans are not a preferred prey of the white shark. We're not on his menu. We don't have what the white shark is interested in, which is a very thick blubbery layer that's high in energy. [00:29:12] Speaker 1: Marco will never know if the great white was simply curious or tasting him as a possible food source. But when great whites do find their perfect prey, their predatory techniques are precise and lethal. One of the most spectacular examples of great whites' stalking and attack techniques is called a surface charge or breaching. Although this behavior is most commonly observed off the coast of South Africa, marine biologists have seen it occur in the red triangle. As great whites prowl from below looking up for potential food, they can be masters of shock and impact. Their deep gray coloring on the top side makes them difficult to spot from above. When a great white spies on a pinniped, a seal or sea lion, it often circles back and returns at an angle that will give the ultimate advantage. [00:30:11] Speaker 9: The way that white sharks predate is that they will wait for a pinniped, usually an individual, to swim at the surface. What they're doing is they're at the bottom. And they'll wait for that pinniped, or whatever the prey is, to swim over the top of them. And then they'll make a swift, instantaneous strike and actually kill the prey. [00:30:37] Speaker 1: Given that great whites sometimes reach 5,000 pounds, as they charge to the surface at speeds approaching 25 miles an hour, the impact on sea lions or elephant seals can be devastating. Thirty miles west of the Golden Gate Bridge in the red triangle are the Farallon Islands. They offer one of the best locations to witness great white predatory behavior. Each year, far from human disturbances, as many as 5,000 seals and sea lions gather. And in September, October and November, the great whites also come here, between 35 and 40 of them. Wildlife biologist Adam Brown patrols this red triangle outpost, watching for predation events. [00:31:31] Speaker 9: An attack is a very exciting thing. What we usually see first is we see a flock of birds circling over the event. They usually cue in on the movement in the water. And then usually you see the blood or you see the slick from the actual prey. And then if you're lucky, you'll actually see the shark come up at the surface. [00:31:55] Speaker 1: The red triangle is like a lethal intersection where predator, prey and humans collide. Those collisions also occur off South Australia and South Africa. But over the last 100 years, along South Australia's 3,150-mile coastline, including its islands, there have been only 41 attacks. Along South Africa's 1,739-mile coastline, there have been 49 attacks. But California, with only 840 miles of coastline, has had 70 attacks. That's one attack for every 12 miles of coastline. The explanation has to do with human population growth. Over the last 50 years, the number of Californians has exploded from 11 to 36 million. And with the proliferation of water sports like surfing, diving and kayaking, there's more opportunity for humans to face off with the great white shark. [00:32:50] Speaker 10: There's more people in the water during the periods where most shark attacks take place. And that's basically the dynamic that accounts for that. [00:33:02] Speaker 1: August 26, 1998, at Stinson Beach, just north of San Francisco and near the center of the red triangle. 16-year-old Jonathan Cathrine hits the waves with a boogie board in waters only seven feet deep. [00:33:19] Speaker 13: I was about 50 yards offshore and I had paddled out with a friend and I had a wetsuit on and he didn't. So after maybe 20 minutes of being in the water, he got cold, got out, headed straight into the main lifeguard tower. We were waiting for some other friends to arrive and meet us. And I was paddling parallel with the beach along the shore. And my right hand hit something underwater. And my mind really went through all the possibilities of what that could have been. I thought seal, jellyfish. Funny enough, I actually thought maybe that's a big pile of sand underneath me. It was a rough, but somewhat soft, wet feeling solid object, sort of like wet sand. And then I had this funny image of a pile of sand in my mind and realized that couldn't have been it. I was in about seven feet of water and realized that I needed to get out of there. I started to think maybe it could be a shark. And so I headed to shore as fast as I could, but just couldn't get to shore fast enough. [00:34:27] Speaker 1: Suddenly, something slams him from below. [00:34:30] Speaker 13: The shark came up from beneath me on my right side, lifted me up and brought me underwater. And as it was swimming underwater, I decided that I couldn't fight it off. But what I could do was hold on to it. Well, I quickly found out it was actually too big to reach my arms around and even hold on to. And so I opened my eyes and saw these giant gill slits and I grabbed on. And as soon as I grabbed on it, let go. [00:35:00] Speaker 1: As sudden as the attack, the shark releases Jonathan. Still attached to his board by a leash, he climbs on and begins to paddle to shore. But with the first kick, he realizes something is wrong. [00:35:15] Speaker 13: I couldn't kick my right leg. I knew it was still there, but I couldn't kick it because my quadricep right above my kneecap was completely severed. So I swam in basically using everything but my right leg. [00:35:31] Speaker 1: Jonathan's friend and nearby lifeguards help him to shore and wait until medical assistance arrives. At the hospital, Jonathan undergoes just under seven hours of surgery, requiring hundreds of stitches to reconnect severed muscles, repair his crushed knee, and close his wounds. [00:35:54] Speaker 13: So the shark bite basically covers the whole top half of my leg. And you can see this is the top jaw. I was laying on my stomach when I was attacked. And the bottom jaw, you can't see as well, but starts in here. And then actually there are teeth marks in all the way up through the inside there. [00:36:13] Speaker 1: It's a massive bite, and Jonathan is fortunate to have survived. But with the abundance of natural prey, what drove the great white to attack Jonathan? Do great whites simply have a voracious appetite? Surprisingly, despite their size, great whites are remarkably efficient at preserving energy. These amazing animals can survive months without eating or swim more than 2,900 miles on one meal alone, typically a seal or a sea lion heavy with fat. [00:36:45] Speaker 9: The sharks don't have to predate multiple times to expend energy. They can expend a little bit of energy to gain a lot. [00:36:56] Speaker 1: What's the secret behind their ability to conserve energy? Great whites are equipped with a sophisticated circulatory system that works like a radiator. It's capable of maintaining a great white's body temperature up to 18 degrees higher than the surrounding water temperature. This allows them to move quickly and to capture pinnipeds in the cold waters of the North Pacific. In fact, humans use up to five times more energy sitting still than a great white does swimming through the cold ocean waters. [00:37:27] Speaker 4: So they don't have to eat the same amount of food that a hot-blooded animal would have to eat. But interestingly enough, white sharks and some of their close relatives are warm-bodied, not warm-blooded but warm-bodied, and are able to elevate their body temperature through a very complex evolutionary mechanism. [00:37:52] Speaker 1: Instead of being driven by blind hunger, there might be another reason behind the shark's attack on Jonathan. And this explanation has more to do with where Jonathan was in shallow water, close to where many ocean predators hunt. [00:38:08] Speaker 12: Killer whales in Patagonia, with the seals up on the beaches, swam up onto a sandbar, grab a resting seal, pull it back into the water, and carry it off. [00:38:20] Speaker 1: In the Red Triangle, a similar drama is acted out very close to shore, this time between great white sharks, seals, and other pinnipeds. During the breeding season, the shallow water surrounding the seal colonies can turn into high-stakes danger zones. Particularly at risk are pups. When a female elephant seal nurses, she gives up to 40% of her body weight to the pups. At the age of four weeks, the pups are nearly 50% fat, perfect for the great white's diet. These pups are naive when it comes to predators. When they enter the waves for the first time, they could become the perfect prey. [00:39:03] Speaker 5: They are vulnerable. And as a result, the most dangerous period in the life of the seal is the first year, the first time at sea. When 50% of them that are weaned successfully by the mother go to sea and don't come back. [00:39:18] Speaker 1: This aspect of the Red Triangle embodies Darwinistic principles at their cruelest. If the seal pups can break through the shark's line of defense, they have the opportunity to grow and procreate. If not, the seal becomes prey, weeded out from the gene pool for good. [00:39:37] Speaker 14: The place where we're most likely to see predation of sharks on elephant seals is going to be in the vicinity of these rookeries. That's where the animal is constrained by the bottom and that's where the shark can count on running into seals. [00:39:51] Speaker 1: When humans like Jonathan enter the shallow waters to surf or boogie board, they're entering this natural predatory environment. What's worse, the breaking waves create poor visibility underwater. Although great whites have good eyesight, the turmoil of the water and sand can cloud their vision. If a great white's not sure what you are, it might assume you're its natural prey and hit hard. [00:40:16] Speaker 12: The waves are breaking. This stirs up a lot of sand. The water is very turbid. It's cloudy. When a shark can see you clearly, he is less likely to bite you in a predatory attack than he is if he can't see you clearly. [00:40:38] Speaker 1: Jonathan will never know why the shark attacked him. Yet this near encounter with death has taught him a valuable lesson about life. [00:40:47] Speaker 13: I really tried to turn the shark attack into a positive experience. As difficult as it was at the time, it really taught me a lot about relationships, about my friendships. [00:41:03] Speaker 1: In the Red Triangle, where more great white attacks on humans are recorded than anywhere else in the world, some animals may be able to clue us in on dangerous waters. Can we pick up on this critical warning? October 10, 2004. Peter DeYoung takes his surfboard out to Limontor Beach at Point Reyes, National Seashore, near the upper corner of the Red Triangle. Peter's been surfing for 40 years, and he's yet to encounter any great whites. This morning, he arrives at the beach just before dawn. Already, he notices something unfamiliar in a sea lion's behavior. [00:41:47] Speaker 15: California sea lions don't typically come ashore there. I came upon a California sea lion as I walked down the beach. And I noted that it was quite unusual, but I was pretty excited about the surf. [00:42:05] Speaker 1: The sea lion on shore gives Peter pause. But when he spots two surfer friends already in the ocean, he decides to hit the waves. After a half hour in the water, he encounters another sea lion, and this one is extremely agitated. [00:42:24] Speaker 15: It was roaring, teeth bared within probably 10 feet of me. [00:42:31] Speaker 1: The sea lion, the natural prey for great whites, is making a run back to the beach. It could mean a shark's in the water, and it could launch an attack on Peter at any moment. Although Peter's enjoying the waves, the sea lion's erratic behavior puts his nerves on edge. [00:42:53] Speaker 15: I saw something submerge quickly about 50 yards offshore. So I focused on that point, and within a few seconds, a loon popped up. So I thought, oh, okay, that's all right. It's just a loon. [00:43:14] Speaker 1: Peter calms down and waits for the next wave. [00:43:22] Speaker 15: I was all of a sudden propelled from behind. What popped into my mind was, I've just been run into. What out here? What just hit me? And then I looked down, and there was a shark with my leg in its mouth, just looking at me. [00:43:46] Speaker 1: The shark could bite down. Peter could lose his leg, and possibly his life. [00:43:52] Speaker 15: I went into instinctual survival, and I just yelled as loud as I could, and I swung my fist down, hitting the shark on top of the head. And the next thing I knew, something flashed by my face, and then I was in the water. [00:44:12] Speaker 1: Suddenly, the great white lets go of Peter. He swims as fast as he can towards safety. [00:44:24] Speaker 15: I felt like I had a ton of lead on my back. I could not paddle fast enough. Back on the beach, Peter is all alone. Then I thought, oh, maybe, maybe it didn't cut me. And I lifted up my leg, and looked over my shoulders, and saw that, oh, you're not that lucky. I looked down at my right leg, and saw that there was a pretty good gash. He calls for help on his cell phone. A helicopter quickly arrives. I had a hundred staples, both in my leg, my calf, and the bottom of my foot, and around both ankles. So it basically just grabbed a bony appendage that didn't have much meat. [00:45:22] Speaker 1: The great white chose not to make a meal out of Peter. Perhaps the attack was motivated by something else. Was the aggression a form of territoriality? [00:45:36] Speaker 12: He might perceive you as a potential threat to either a food source, or an area, or a female getting ready to give birth. So they will strike at you in order to get you out of the area, to chase you away. Some people refer to this as territoriality. [00:45:55] Speaker 1: Whether it's food or competition, great whites can sense the presence of another creature long before they can see it. Around their snout, chin, and forehead, great whites have highly tuned sensory organs called ampulli of Lorenzini. This network of jelly-filled canals detects the slightest electrical activity, as little as a few billionths of a single volt. All living creatures send off electrical signals through activity in their nerve cells, and the great white's electrical receptors hone in on the pulse. This helps the shark find its target. Peter will never know whether the shark saw him as an intruder, a potential food source, or an object of curiosity. But he knows firsthand what it feels like to be stalked by one of the world's most stunning alpha [00:46:48] Speaker 12: predators. The majority of the attacks on humans by white sharks are not motivated by predation. In other words, they're not mistaken identity. They're investigation. The shark is not sure what it's observing, so it comes in and does the last thing that it will do when it examines an object, and that is to take a bite of it. They generally will bite a human, hold them for a few seconds, and release them. [00:47:23] Speaker 1: By observing great white shark behavior in the red triangle, it's become clear that attacks on humans are not motivated by appetite. Instead, most white shark attacks may be prompted by curiosity and a large animal in the red triangle in the red circle. The shark's natural prey, combined with a high human population that increasingly enjoys water sports. Most survive the encounters. Still, there are precautions people can take. Stay away from seal and sea lion rookeries, the great white's favorite hunting grounds. Never enter the water alone. And above all, respect your humble place in the food chain when it comes to these underwater alpha predators. After all, this is their rightful territory. We are only visiting. [00:48:19] Speaker 9: The fact that sharks predate on people is, you know, it definitely is a scary thing. But what people have to understand is that sharks are not looking for people to predate on. Sharks are looking for pinniped. I think that instead of being scared, people should just have a healthy respect for the shark's natural history and what they're doing in the water. [00:48:46] Speaker 1: The red triangle is both a danger zone and a zone of discovery. A lethal intersection between predator, prey and sometimes humans. A place for terror and wonder, fear and fascination for one of the the world's greatest mysteries. The great white shark.