United States

"The sharks are very territorial and can exhibit extremely aggressive behavior..."

Bull shark attacks mostly occur in shallow, murky warmer waters. Their preference for feeding under these conditions increase their interaction with swimmers.

The bull sharks came back into spotlight following the attack on 12-year-old, Nicholas Vossler. Vossler was swimming near Matagorda Island, Texas, when a bull shark attacked the boy and severely injured his foot, according to Firstcoastnews.com. The water was only about 3 feet deep. Following surgery, Vossler is expected to regain full use of his foot.

According to Nationalgeographic.com, bull sharks prefer coastal waters that are less than 100 feet deep. This is thought to make them the most dangerous sharks of all to humans.

The sharks can inhabit both salt and fresh waters. They have kidneys that can recycle the salt within their bodies and special glands that also aid in salt retention.

The bull sharks can grow to about 7.5 feet and weigh up to 285 pounds. The sharks are very territorial and can exhibit extremely aggressive behavior towards anything, including humans, that enters their territory.

The sharks are frequently spotted in Florida's coastal waters. There have been two known fatalities near Florida between 2000 and 2005 attributed to bull shark attacks. Jamie Marie Daigle, 14, was killed June 25, 2005 while swimming with a friend on a boogie board, according to Cbsnews.com. The attack happened only 100 yards from shore.

On Aug. 30, 2000, Thadeus Kubinski, 69, was killed while swimming with his wife. The shark attack occurred at about 4 p.m. and he was less than 10 feet from a dock.

Shark attacks are not frequent, but the results of an attack can be deadly. There are several ways you can reduce the chance of an attack.

Follow these helpful tips from George H. Burgess of the Florida Museum of Natural History.

Stay in groups. Avoid swimming during darkness or twilight hours. Stay out of the water if you are bleeding. Don't wear shiny jewelry or bright-colored clothing while swimming. Sharks have a keen sense of smell and are attracted to shiny objects in the water.

Most importantly, do not enter the water if sharks are present and evacuate immediately if a shark is seen.