Shark Feeding Frenzy Myth Busted - The Truth About Shark Behavior

Meet Jonathan Bird, one of the world's top underwater nature cinematographers. Traveling the world on assignment for all the major networks, he is an Emmy award-winning authority on the underwater world. In freshwater or salt, reefs, wrecks, or caves, Jonathan documents the world beneath the waves. Welcome to the Blue World. You might not think of sea stars as being very intelligent, and you'd be right. But you might be impressed by some of the amazing things they can do, especially considering they don't have a brain. Starfish, more correctly called sea stars, live just about everywhere in the ocean, from the tropics to Antarctica and everywhere in between. They come in all shapes and sizes, from fat and stubby, to long and skinny. This brittle star walks with a coordinated effort using its rays like legs. But most sea stars get around using hundreds or thousands of tiny tube feet on their underside. This is a northern sea star living in the coastal waters of New England, and it's a predator. It's hunting a scallop. It's a drama played out in slow motion as the sea star moves in for a grip on the scallop's shell. But the scallop is not defenseless. With a mighty blast of water, the scallop jets away to safety. So the sea star wraps itself around a muscle. Muscles are attached to the bottom and can't get away. The sea star uses its strong tube feet with suction cups to pull the muscle open a tiny bit and digests its victim by injecting its stomach inside the muscle. Picking up the sea star, I can see that it has the muscle firmly in its grip. But not all sea stars feed on muscles and scallops. A basket star feeds on plankton in the water. It has finely branched arms that act like a net to catch the tiny bits of food floating by. It positions itself to be able to grab as much plankton as possible in the current. Some sea stars eat something even more surprising. Come take a look. Exploring a reef in the tropical Pacific, I find a crown of thorn sea star dining on the coral. This thorny armored sea star is one of only a few animals that can digest living coral. It wraps itself around a coral colony and eats the polyps leaving a dead bleached coral skeleton behind. Here's a healthy colony of plate coral and here's one that's been eaten by a crown of thorns. Outbreaks of these sea stars have been known to kill entire reefs. Carefully picking one up to avoid the sharp and venomous spines, I can see the stomach which the sea star inverts out of its mouth to digest the coral outside of its body. These sea stars are the second largest in the world growing bigger than a dinner plate. But if you think these are big, wait until you see the largest sea star in the world. To find it I've come all the way to British Columbia. I'm looking for the giant Pacific sun star and you won't believe the size of this thing. In the cold murky waters of the Canadian North Pacific, I swim through beautiful gardens of sponges, anemones and soft coral searching for a giant sun star. And then down on the bottom, I find what I'm looking for. It has up to 24 arms, more properly called rays, and reaches three feet across. This is the world's largest sea star. Compared to most sea stars, the giant sun star is a speed demon, cruising along the bottom in search of its favorite food, other sea stars, and the occasional sea cucumber. Here a sea cucumber makes an emergency retreat to escape this hungry sun star on the move. A thousand miles south on a reef in the tropics, I find a blue Lynchia sea star on the bottom. Like the vast majority of sea stars, this one has only five rays. With tiny tube feet on its underside, this sea star barely seems to move, but when I speed things up with time-lapse photography, Lynchia sea stars appear very active, moving about and grazing the bottom for food. But even more curiously, they are polite, restraining from walking on top of each other. Like bumper cars, when one Lynchia touches another, they each go the other direction. It's all very civilized. In an hour, a Lynchia on the move can travel several car lengths. Sea stars are amazing animals. They might look like they are just sitting there doing nothing, but they survive by hunting for food, and they do that in many ways, from catching it as it floats by, to chasing it down. They are such good predators that sometimes they can destroy entire reefs. It goes to prove that just because something is slow doesn't mean it isn't up to something. You never know where a sea star is going to turn up. Underwater photography is a fantastic job. Although I enjoy diving all over the world, I have to admit that exploring coral reefs in clear water is the most relaxing and peaceful part of my job. There are all kinds of wonderful animals to meet on coral reefs, such as a pointy lionfish, or a curious octopus looking me in the eye. I never get tired of watching anemonefish though. Outside of the world of diving, very few people had heard of anemonefish until Disney and Pixar came along. In the film Finding Nemo, an anemonefish plays the starring role. In real life, these little fish are a lot different from their Hollywood portrayal. I mean, other than the fact that they don't actually talk. But you may find these colorful little fish quite surprising. Join me on a dive and meet some real anemonefish! Anemonefish are found all over the tropical parts of the Indian and Pacific Oceans. They are quite common on coral reefs, so it won't take me too long to find one. Searching a reef on the Pacific island of Yap, I soon come across a pair of orange fin anemonefish, frolicking in an anemone that looks like a shag carpet. They are not afraid of me at all. I can swim right up and look them in the eye. There are 28 different species of anemonefish, all of which are very colorful, but the clown anemonefish, sometimes called the clownfish, is probably the most beautiful. This is the species that was the basis for the character in Finding Nemo. Anemonefish get their name because they live in a toxic anemone. This lush carpet has venomous tentacles that sting most fish. But the anemonefish is covered in a special slimy mucus that keeps the anemone from stinging it. Because of this adaptation, the anemonefish can live protected by the anemone, happily playing in the very tentacles that would kill other fish. Anemonefish are not the only animals that can live in the anemone. Cleaner shrimps hide here as well. They eat by cleaning the parasites from the fish, and, in exchange for their services, the fish graciously don't eat the shrimp. But it's hard to relax when you're battered around by hyperactive anemonefish all day long. Protection afforded by the anemone is the reason why the anemonefish aren't afraid of me. They know that the anemone's stinging tentacles keep them safe. If another fish like this damselfish comes near the anemone, the anemonefish become territorial and chase it away. They protect their anemone just as much as the anemone protects them, so it's a good relationship. And if a fish gets too close, the anemone gets a meal, using its venomous tentacles to sting and disable the fish. This fish is lunch. The anemone might look like some kind of weird plant, but it's actually a simple animal with a mouth in the middle. It's basically a jellyfish that can't swim. The anemone is a formidable ally to the anemonefish in more ways than one. They use the protection of the anemone to keep their eggs safe too. The female anemonefish deposits her eggs on the reef under the edge of the anemone. Then her subservient males take over. The males provide all the egg care. The female just sits back and watches. In any group of anemonefish, there is always one anemonefish which is the largest. This is the dominant female. In anemonefish society, the females are the boss. One of the most interesting things about anemonefish is that they are all born male, but as they mature, some will completely transform into females. Only when the dominant female dies will the next male in line get the chance to transform into a female and become the head honcho. Until then, all the smaller anemonefish in the anemone are subservient males. Truth is stranger than fiction as it turns out, and as my dive comes to an end, I realize that anemonefish are even more fascinating than Hollywood would have us believe. The animals of the ocean truly are remarkable. Don't go away! Jonathan is about to go into the water with 30 hungry gray reef sharks. Many people seem to think of sharks as killing machines that go crazy if a single drop of blood touches the water. Gray reef sharks are one of the most aggressive sharks in the world, and they travel in schools of dozens of animals. When I dive into the water with these sharks, the splash gets their attention, and they come over for a look. They quickly size me up and realize that I don't look like food. Scuba divers not only don't look like fish, but don't act like them either. The sharks soon get bored and move on. But what would happen if there was blood in the water? Will sharks have a feeding frenzy? Will they attack everything in sight? To find out, I've traveled to Yap, an island in the middle of the Pacific Ocean, where large numbers of gray reef sharks patrol the reefs. The water is crystal clear, an ideal place to perform an experiment with sharks. I can keep my eye on them from a long way away. The experiment begins with some leftover fish that we will use as bait. I place this bait into a plastic crate so it will create a scent in the water, but the sharks won't be able to reach it. Go find some sharks! Soon, Captain John and I depart from the dock and make our way across the lagoon to the outer reef, home of the gray reef sharks. On site, I lower the ladder and we discuss our experiment. So John, you and I are going to be down on the bottom. We're going to go in first, right? And we're going to wait for Mike to put the bait in. Is that the plan? I'm working with two experienced Yappies divers who are going to help with my experiment to find out if sharks will form a feeding frenzy if we put a lot of bait into the water. First we prepare our dive gear. And I get suited up. Next, John rolls into the water. He heads to the bottom and attaches a rope to a dead section of reef where we won't hurt the coral with the crate full of bait. Now it's my turn to go into the water. Mike throws the bait into the water with the rope attached, and I follow it down. The fish are the first to figure out what's going on. They feed on the little scraps coming out of the crate as it makes its way to the bottom. John is pulling it down by the rope, so he doesn't need to swim with the crate among the sharks that are lurking. Once it hits the bottom, I move the crate to a hole in the reef with John's help. The first part of my experiment is to see if the sharks will find the bait if they don't actually see it. It only takes about 5 seconds for the sharks to find the bait hidden in the reef. More than 30 sharks surround me as they take turns swimming under to investigate the source of the smell. If there's one thing that sharks can do very well, it's smell things. And they smell dinner for sure. The sharks can't get to the fish where it's hidden, so I move it out into the open. I leave the wire cover on. Surely this will drive the sharks crazy and they'll start attacking the crate. Not really. The sharks seem to know that they can't get at the fish, so they just keep circling. One bumps my camera. Probably an accident because I'm too close to the bait. Well, if that doesn't drive the sharks into a bloodthirsty feeding frenzy, maybe removing the top of the crate will produce the expected result. I open the top and stand back. Now the sharks are free to feed all they like. It doesn't take long for the sharks to figure out that something has changed. I can see their excitement level increase. They're swimming a little faster and investigating the crate more, but they still aren't going into a feeding frenzy. They look pretty civilized to me. Only one shark makes a bold move and sticks her head right into the crate for a tasty piece of fish. Once all the other sharks see that, they start rushing in for their own bite. Now the sharks are getting really excited. They all want to get a piece of fish before it's all gone. But this certainly doesn't look like a feeding frenzy to me. The sharks are pushing and shoving each other a bit, but they aren't biting each other and they haven't paid me any attention at all, even though my camera is stuck practically right next to the crate full of fish. In all of the excitement, one of the sharks grabs one of the tripod legs on my camera. Watch it again from another angle. I'm definitely glad that is just a piece of plastic and not my arm. But to be fair, I have the camera practically inside the crate, so the sharks are grabbing anything that looks biteable in their competition to feed. After all the bait is gone, the sharks return to normal almost instantly. They go back to slowly patrolling the reef and pretty much ignore me. As my tank gets low on air, I swim out into the blue to get a few last shots before I head up to shallower water to decompress below the boat. That was incredible! So many sharks! Gray reef sharks, silver tips, black tips, and yet I still have all my limbs. Who can explain it? Well, you know it just goes to show you, sharks are not bloodthirsty killers. Later, on my second dive at the same site, we search the reef for souvenirs. As the sharks feed, they often lose teeth in the process. Sharks have a never-ending supply of new teeth, so when they lose a few, it's not a big deal. I find a few in the cracks below the spot where the crate was sitting. Here they are. They're pretty small. They don't look like much. They sure are sharks. So, I tried to make a feeding frenzy, and it didn't work. I didn't get eaten alive, and the sharks actually seemed very much in control. I proved something important. Sharks are not stupid. They eat fish, and they have a pretty good idea what a fish looks like. Divers are just not on the menu. Because of this, shark diving has become a safe and popular activity where people can get up close and personal to these amazing predators. All over the world, tens of thousands of divers go diving with sharks every year. It's exceptionally rare for anyone to be bitten. Most people find the experience not just exciting, but interesting. Sharks are beautiful animals, and perhaps nature's most evolved predators. Yet, we can watch them from very close range without being attacked. You would not be able to get this close to lions or bears without being in great danger. It's just another incredible thing that can only happen in the ocean, and another reason I love the Blue World.