Then it attacks quickly, moving its head up to the surface to grab the unlucky victim. The shark swims under the surface until it's just a few feet away from its prey. An underwater approach is used most often.One scientist conducted a study in which he presented a great white shark with a plywood seal-shaped board and a square board, and found that the great white made more passes at the seal-shaped board. It scopes out the water's surface for seals and then approaches them from underwater. While sharks are equipped with impressive noses and ears that help them to hunt their prey, the great white seems to rely most heavily on its sense of vision. The great white shark consumes approximately 11 tons of food in one year (for comparison's sake, a 150-pound (68-kilogram) human being wolfs down about half a ton). They'll also dine on other fishes and occasionally sea turtles. As we mentioned, humans are generally too muscular and lean for a typical shark meal, but a seal might be 50 percent fat, representing a very efficient meal for great whites. That's why its main prey item is the pinniped, an aquatic carnivore like a seal or a sea lion. Like some of us, the great white prefers a fatty meal to one with lots of protein. Lionel Isy-Schwart/The Image Bank/Getty Images
