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Summer of the Shark

Sharks don't really like to bite people. A great white shark prefers a nice, chubby seal. A bull shark likes to fill up on fish or even another shark. Then why has this summer been so full of frightening news about shark attacks? That, scientists say, is a very good question.

Overall, your chances of being bitten by a shark are pretty small: You're 30 times more likely to be struck by lightning! Still, the number of shark attacks has been creeping upward for more than ten years. Last year was one of the worst on record, with 84 attacks worldwide. So far this year there have been 52. Most occurred in the waters off Florida and Australia.

Only three of this year's attacks were fatal. On September 1, a shark killed a young swimmer in Virginia. Two days later a shark killed a man off a North Carolina beach. Both attacks happened at dusk. Shark attacks usually take place in the morning and early evening. That's when most sharks hunt their prey.

A Case of Mistaken Identity?

Scientists believe that the main reason for the recent rise in attacks is simply that there are more people swimming, boogie-boarding and surfing than ever before. Volusia County, Florida, holds the national record for shark attacks because its long coastline and beaches are packed with bathers.

It's not a case of sharks preying on humans, says Dr. Robert Lea, a marine biologist. It's just humans sharing a spot in the ocean with sharks —at the wrong time.

Researchers who study shark behavior believe that most shark attacks are a case of mistaken identity. A shark might think a human foot is a flounder. Sharks usually spit out human flesh after the first bite!

Who's Threatening Whom?

Sharks are one of nature's ultimate designs: confident, sleek and deadly. Three types account for most attacks on people—great whites, tigers and bull sharks. Scientists have been using satellites to study these sharks as they move through the seas.

Great white sharks keep their blood warmer than the surrounding water. They hunt during the day. Their method of attack is to shoot up vertically from 30 feet under, knocking their prey right out of the water.

Tiger sharks hunt at night and are "willing to try anything for food," says Rocky Strong, a shark biologist.

Bull sharks are the only sharks that can live in both salt and fresh water. They have been seen swimming in the Mississippi River.

Scientists who work with sharks know how dangerous they can be. Still, they say sharks have more to fear than humans do. Fishing nets entangle and drown about 100 million sharks each year.

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A Shark's Super Senses

Sharks have been swimming in the earth's oceans since dinosaurs roamed the earth millions of years ago. A close look at their bodies shows why they are such survivors. From nose to tail, they're packed with sensing equipment that helps them track down their prey.

SEEING
Like a cat, a shark can see in dim light. It must move its head from side to side to see objects directly in front of it.

HEARING
Tiny holes on top of the head lead to very sensitive ears. A shark can pick up the sound of a struggling fish 600 yards away.

SKIN
A shark's skin is covered with a protective layer of tiny, toothlike scales called denticles.

SENSING
The lateral line is a row of pores with vibration-sensitive hair cells that runs along the shark's sides. These allow a shark to sense the faintest flutter of a nearby fin. Other pores located on the head detect tiny electrical fields created by other fish.

SMELLING
A shark can smell even a tiny drop of blood in the water.

A BIG BITE
A shark's jaws contain many rows of razor-sharp teeth. When a shark takes a bite, it lifts its snout and its entire jaw slides forward. A great white's bite is so powerful it can exert pressure of 2,000 pounds per square inch.

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