Sharks have a bad name. Some people think there are hundreds of sharks, (mainly great whites) waiting to tear into people on the shoreline. Sharks don't lurk in the water waiting for legs to appear so they can start eating. It's true that great whites are responsible for most attacks, but because of overhunting they're rare in some parts of the world. Sharks do bite the occasional person but that's no reason for them to have such a bad rep.
Size of a Bus
There are about 368 different species of sharks that live all over the world. They range in size from a person's hand, to bigger than a bus. Most shakrs are about the same size as people (five to seven feet or 1.5 to 2.1 meters.) The whale shark is the largest shark in the world. It's about the size of a bus and weighs more than two African elephants. The most common is the spiny dogfish shark.
This Side Up
Sharks can have up to 3,000 teeth and if they lose one, another one grows back. Even with all those teeth, sharks don't chew their food. They gulp it down in large chunks. One interesting thing about sharks is that they don't have any bones. Their skeleton is made of cartilage - a tough, stringy material not as hard as bones (your nose is made of cartilage.) They don't have a swim bladder either - the balloon like organ full of air that keeps most fish upright. Ever see the label "This Side Up" on boxes? Sharks should have the same label. If they get turned over (so they float belly up) they go limp and look like they're in a trance.
When Sharks Attack
If you hear the word shark and think of some vicious, attacking fish with big sharp teeth - think again. Sharks don't chase people like in the movie Jaws. Every year there are probably 70 to 100 shark attacks all over the world. Of those only five to 15 people end up dead. I use "probably" cuz not all shark attacks are reported. Third World countries don't like the bad publicity.
So now you know. Only about a dozen people die from shark attacks each year but the number goes up every year. This is cuz there are more people in the water. Most attacks happen in shallow water (just like in the movies), near a sandbar or between sandbars where sharks feed and can get trapped at low tide. Areas with steep dropoffs are also common attack places. Sharks can usually find dinner in these areas, so if divers or swimmers are there, they could end up on the menu.
Just because attacks are going up doesn't mean you should be avoiding the water. Sharks are intelligent animals that like to stay away from humans. The hammerhead is the most aggressive but even they only attack if they mistake a person for food or are being bothered. And even then, people are spit back out. Guess we don't make the best tasting meals.