Food and Feeding Behavior

White sharks are predatory animals that begin life by feeding on fish, rays, and other sharks, and as they grow, switch to feeding on marine mammals and scavenging on large animal carcasses. Their first mammalian prey are usually the small harbor seal, but as the sharks increase in size, they become large enough to eat sea lions, elephant seals, and small toothed whales. Attack strategy consists of a swift, surprise attack from below, inflicting a large, potentially fatal bite. The pinniped often dies from massive trauma or blood loss, but the bites may be superficial or misplaced on the body, allowing the seal to escape and survive the attacks with their scars as witness. Large white sharks will also scavenge on the carcasses of whale sharks, and on the fat-rich blubber layer of dead whales. They will occasionally feed on sea turtles and sea otters, and are known to attack, but not eat, humans

Sharks and Media

Media sensationalism and widespread ignorance has given the white shark a bad rap. Although the species is responsible for an average of 2-3 non-fatal attacks on swimmers, surfers, and divers each year, its role as a menace is exaggerated; more people are killed in the U.S. each year by dogs than have been killed by white sharks in the last 100 years. Additionally, scientific studies show that population of white sharks is low, with perhaps fewer than 100 adult animals in the state's waters. White sharks are important predators in the marine ecosystems of the California coast, and the people of California recognize that. In 1992, the white shark was placed on the protected species list for the state of California, and is legally protected from unlawful killing or exploitation. The original bill was supported by both scientists and fishing organizations, surfing clubs and diving groups, private citizens and an array of government organizations. With your support and respect, we can continue to live with this complex and misunderstood animal.
Studying the white shark requires the use of media equipment. The 10 images above were acquired during a pilot project run at the University of California Museum of Paleontology, the Department of Integrative Biology, and the Point Reyes Bird Observatory. Dr. Douglas Long has been doing research on the ecological interactions, in particular the feeding habits and predatory behavior of great white sharks on marine mammals along the coast of central California for several years now. His research has included autopsying dead marine mammals, studying the feeding behavior of sharks, and trying to estimate shark population size. These images are directly related to the latter two aspects of his research. From a post on the Farallon Islands, researchers watch the waters for injured marine mammals and signs of sharks feeding. When they spot a feeding shark, they travel in a small boat to the site, and when the shark comes close they stick a small hand-held waterproof video recorder under the water and film the shark as it passes by. The sharks are identified by characteristic marks like scars and skin blemishes. Most of the pictures at the end of this exhibit were taken with the express intent of looking for these scars, so they may not be the most aesthetic images possible. However, they are the most useful. The ability to visually identify sharks allows researchers to tell more about migration, ranges, and the number of individual sharks in the area. Douglas believes that there are a

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Great White Shark Range

Fast Facts
Type: Fish
Diet: Carnivore
Size: 15 ft (4.6 m) to more than 20 ft (6 m)
Weight: 5,000 lbs (2,268 kg) or more
Group name: School or shoal
Protection status: Endangered
Did you know? Great whites can detect one drop of blood in 25 gal (100 L) of water and can sense even tiny amounts of blood in the water up to 3 mi (5 km) away.
Size relative to a bus: The legendary great white shark is far more fearsome in our imaginations than in reality. As scientific research on these elusive predators increases, their image as mindless killing machines is beginning to fade.

Of the 100-plus annual shark attacks worldwide, fully one-third to one-half are attributable to great whites. However, most of these are not fatal, and new research finds that great whites, who are naturally curious, are "sample biting" then releasing their victims rather than preying on humans. It's not a terribly comforting distinction, but it does indicate that humans are not actually on the great white's menu.

Great whites are the largest predatory fish on Earth. They grow to an average of 15 feet (4.6 meters) in length, though specimens exceeding 20 feet (6 meters) and weighing up to 5,000 pounds (2,268 kilograms) have been recorded.

They have slate-gray upper bodies to blend in with the rocky coastal sea floor, but get their name from their universally white underbellies. They are streamlined, torpedo-shaped swimmers with powerful tails that can propel them through the water at speeds of up to 15 miles (24 kilometers) per hour. They can even leave the water completely, breaching like whales when attacking prey from underneath.

Highly adapted predators, their mouths are lined with up to 300 serrated, triangular teeth arranged in several rows, and they have an exceptional sense of smell to detect prey. They even have organs that can sense the tiny electromagnetic fields generated by animals. Their main prey items include sea lions, seals, small toothed whales, and even sea turtles, and carrion.

Found in cool, coastal waters throughout the world, there is no reliable data on the great white's population. However, scientists agree that their number are decreasing precipitously due to overfishing and accidental catching in gill nets, among other factors, and they are listed as an endangered species.