Researchers believe that there are three major kinds of unprovoked shark attacks: hit and run, bump and bite, and sneak. Most shark attacks on people involve only a single bite that occurs during a hit and run. The bump and bite and the sneak attack are more dangerous because during them the shark may bite the victim several times.
Researchers have shown that the shark uses several senses to identify its potential prey. First the shark hears and feels the vibrations of sound waves created by motion, probably interpreting the splashes of swimmers and divers as the movement of an injured fish or seal. The chemical odors all living things emit even underwater also alert the shark that a potential meal is nearby. The shark is also drawn to prey by what it sees. Contrasts and bright colors seem to attract it.
The shark concludes its exploration of a human in the water through physical contact often in the most common kind of attack, the hit and run. Sometimes, a shark will exhibit"threat posture" before an attack, pushing its pectoral fins downward, arching its back, and raising its snout.
Hit and run: This is the most common kind of attack, typically in the surf zone, with swimmers and surfers the usual targets. The victim and shark meet unexpectedly. Cornered or perhaps defending territory, a shark makes an aggressive gesture, which the person fails to recognize. Then the shark strikes and speeds away. The attack is rarely fatal.
The victim seldom sees the attacker, but sometimes a shark will precede an attack by changing its normal smooth swimming to a jerky, rigid, unusual pattern. In a hit and run, the shark inflicts a single bite or slash wound and does not return. Most of the time, these probably are cases of mistaken identity that occur in murky water when the shark may confuse a person with a seal or sea lion. A feeding shark must make quick decisions and rapid movements to capture its traditional food items. Adding to the conditions for an attack are what researchers call "provocative human appearance" — splashing, shiny jewelry, brightly colored swimsuits, tanning that produces contrasting skin-swimsuit colors, and tanning that makes tempting little targets of the white soles of the feet.
"We suspect that, upon biting, the shark quickly realizes that the human is a foreign object, or that it is too large, and immediately releases the victim and does not return," says a report based on International Shark Attack File data. "Some of these attacks could also be related to social behaviors unrelated to feeding, such as dominance behaviors seen in many land animals." Hit and run victims usually suffer relatively small cuts and scratches, often on the leg below the knee.
Bump and bite: This is a more serious kind of attack. A brief bump against the object brings the shark's electroreceptors into action. After determining that the object is alive, the shark may then bite it. The shark initially circles the victim before bumping. The assumption is that the person does not provoke the shark but is merely regarded as prey, which the shark takes the opportunity to feed upon.
Sneak: A strike that occurs without warning. The shark simply lunges, usually from below the victim, and bites, usually repeatedly. Bump and bite and sneak attacks, while less common than hit and run attacks, produce more serious injuries and the most fatalities. These types of attacks usually involve divers or swimmers in relatively deep waters, but they also can occur in shallows near shore in some areas of the world. During both bump and bite and sneak attacks, sharks commonly make repeat assaults on the victim, who usually suffers many serious bites. Injuries are usually severe, and the attack is frequently fatal. Researchers believe that the shark is driven by hunger or by a perception of threat by the human being. This is not a matter of mistaken identity. Sneak attacks and bump and bite attacks are also made on the survivors of shipwrecks or downed aircraft.
Where are you going?
What do you want to do?
