Into the wild: Studying the behavior of great white sharks
Into the wild: Studying the behavior of great white sharks
White sharks have been neither bred nor raised in captivity, and, thus, what biologists know about their habits and natural history has come only from direct observation in the wild.
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Transcript
He is the largest and one of the most feared predators of the earth: the great white shark. His name spreads fear and terror. He is common in all oceans of the world and even immigrated to the Mediterranean. Even though his existence is already in great danger, many people still see him as a dangerous man-eating beast that lurks near the beaches around the world. Science knows little about the largest predatory fish on earth. The great white shark was never held or born in captivity.
In the Pacific off the Mexican Island Guadalupe, scientists observe, catalogue and mark the nearly one hundred white sharks who have their hunting grounds here. A dozen local fishermen and the marine biologists are the only humans in this remote and specially protected area. If the researchers want to learn more about the sharks, they have to observe them on the surface or equip them with modern tracking devices to follow them on their journey into the deep ocean. To investigate the behavior of the sharks a diver tries to attract himself to the predator. Sharks are not the greedy monsters who immediately attack anything that moves in the water. First they spy out their potential prey and try to estimate whether an attack pays off. If the animal is not attracted with baits and blood, the shark shows a calm behavior. Not many divers dare approaching close to the animals without a cage. The metal of it is suspected to irritate the animal as a result of electrical potential in the salt water. For the researchers, there are still many unresolved issues. When and where the animals mate? Where they give birth to their offspring? How can people help to prevent the extinction of this magnificent animal? These and many other questions remained unanswered.
To unconceal the secrets of the great white shark, the researchers are on board of a little boat to fix a transmitter on the back of an animal. Receivers are then placed in the water and record the approach of sharks. The divers have to use a harpoon to firmly anchor the transmitters into the extremely tough skin of the animals. If the shot does not have enough penetrating power the harpoon tip just bounces off the skin. The divers know what the hunter is searching for here, his favorite food seals - more precisely, elephant seals and fur seals. The blubber of the giant sea elephant is the ideal meal for a pregnant shark. Surprisingly there is a seal, who seems to have no fear of the shark. It swims close to him and seems to want to challenge him. In comparison to a shark, the fur seal is more maneuverable and faster. But the shark is not on the hunt. The hunting behavior of the great white shark is known for positioning himself under his prey and spying on their behavior. If he considers the situation worthwhile, he attacks quickly. The prey does not notice his attack until it's too late.
With the help of transmitters the study of sharks has brought amazing insights. Sometimes the great white sharks migrate very long distances. A shark that was located near by the Australian coast was found in South Africa five months later. These migration routes are longer than 10,000 kilometers. Researchers hope to effectively define protected areas with the obtained data. In the ecological balance harks are an important factor. The animals off the Mexican coast are under strict protection. The marine watches over the area. Hunters and hunted should find their way back to a natural balance.
In the Pacific off the Mexican Island Guadalupe, scientists observe, catalogue and mark the nearly one hundred white sharks who have their hunting grounds here. A dozen local fishermen and the marine biologists are the only humans in this remote and specially protected area. If the researchers want to learn more about the sharks, they have to observe them on the surface or equip them with modern tracking devices to follow them on their journey into the deep ocean. To investigate the behavior of the sharks a diver tries to attract himself to the predator. Sharks are not the greedy monsters who immediately attack anything that moves in the water. First they spy out their potential prey and try to estimate whether an attack pays off. If the animal is not attracted with baits and blood, the shark shows a calm behavior. Not many divers dare approaching close to the animals without a cage. The metal of it is suspected to irritate the animal as a result of electrical potential in the salt water. For the researchers, there are still many unresolved issues. When and where the animals mate? Where they give birth to their offspring? How can people help to prevent the extinction of this magnificent animal? These and many other questions remained unanswered.
To unconceal the secrets of the great white shark, the researchers are on board of a little boat to fix a transmitter on the back of an animal. Receivers are then placed in the water and record the approach of sharks. The divers have to use a harpoon to firmly anchor the transmitters into the extremely tough skin of the animals. If the shot does not have enough penetrating power the harpoon tip just bounces off the skin. The divers know what the hunter is searching for here, his favorite food seals - more precisely, elephant seals and fur seals. The blubber of the giant sea elephant is the ideal meal for a pregnant shark. Surprisingly there is a seal, who seems to have no fear of the shark. It swims close to him and seems to want to challenge him. In comparison to a shark, the fur seal is more maneuverable and faster. But the shark is not on the hunt. The hunting behavior of the great white shark is known for positioning himself under his prey and spying on their behavior. If he considers the situation worthwhile, he attacks quickly. The prey does not notice his attack until it's too late.
With the help of transmitters the study of sharks has brought amazing insights. Sometimes the great white sharks migrate very long distances. A shark that was located near by the Australian coast was found in South Africa five months later. These migration routes are longer than 10,000 kilometers. Researchers hope to effectively define protected areas with the obtained data. In the ecological balance harks are an important factor. The animals off the Mexican coast are under strict protection. The marine watches over the area. Hunters and hunted should find their way back to a natural balance.