Shark Myth #2: Sharks are mindless eating machines.

Hollywood movies and newspaper reports have given sharks a reputation as stupid, mindless creatures that act like aquatic missiles -- they just swim and swim until they hit a target, and then they eat it. There are two reasons for this myth: 

  1. Tiger sharks do seem to eat just about anything, and tales abound about the strange objects found in their stomachs.
  2. We don't really know much about sharks. They are extremely difficult to study in the wild, and often the only behaviors that we witness are surface feedings.

Just because we don't see complex shark behaviors, that doesn't mean they don't exist. For example, we know that some species have complicated social hierarchies, differentiate between prey and non-prey items, and also use different attack strategies for different kinds of prey.

Shark Attack Damage

The shark had inflicted a half-pie-shaped wound that went from just below my armpit to the middle of my left side...Dr. Starr quit counting the stitches taken when he reached five hundred. - Ken Doudt

An attacking shark can deal massive damage to a human. In some cases, the initial bite is powerful enough to sever a limb completely. The surgeon who operated on a teenaged surfer in Australia described the loss of the surfer's leg as "guillotine-like." Sharks can generate more than 40,000 pounds of pressure per square inch, measured at the tip of a tooth -- large specimens might be capable of even more crushing jaw power.

If the shark doesn't bite off a limb, it generally takes a large chunk of flesh, tearing away muscle and bone. A bite on the torso can result in cracked ribs and other broken bones in addition to massive rips in the skin. In some cases, this can leave internal organs exposed and damaged. Spear fisher Rodney Fox was opened from shoulder to hip by a great white in 1963 near Adelaide, Australia. He survived, though it took 462 stitches and four hours of surgery to repair him.

However, shark attack victims don't usually die from sudden traumatic damage. They usually bleed to death. It can take several minutes to get a victim to shore, and even more time for emergency personnel to arrive. The difference between life and death is usually having someone at the scene who knows how to stem the blood loss, and every second counts. In the case of a boy who was attacked in 2005 off Cape San Blas, Florida, a doctor and a nurse vacationing on the beach put pressure on an artery in his leg, which helped him to survive.

Oddly enough, one of the potential dangers of swimming in the ocean can also help shark attack victims survive. When someone is attacked in cold water, their body temperature can drop dangerously low. This drop in temperature slows down the body's functions, including blood loss. This can keep victims alive for extended periods.

Once the victim has received emergency care, there is another danger -- infection. Shark mouths and ocean water aren't exactly clean. A shark bite inevitably leaves harmful bacteria in the wound, which can be as deadly as the bite itself. Fortunately, modern antibiotics help protect shark victims from these infections.

We'll find out what the most dangerous sharks in the world are in the next section.