Notice that the guy in front of the bull shark is not even waist deep. This guy learns the hard way that the big fish don't always go for the lure: this shark is fixin' to take a bite out of this guy's fishing pole. Ouch!
When Dawn Schauman was attacked by an 8-to-10-ft. bull shark in October 1993, she said, "it felt like a truck had slammed into me, then I felt a compacting squeeze and an acute burning in my left hand and my left leg." The shark spun her around, leaving her disoriented as she hemorrhaged blood into the water. The shark left, and willpower alone got Schauman (6&1/2 months pregnant) back to shore. Her baby was later born prematurely but safely. For months Schauman woke at 3 a.m. replaying the attack in her head.
Considered by shark researchers to be the deadliest shark in the oceans, the bull shark will attack and eat anything. It has no preference for food. It has attacked and killed humans and will continue to do so. The bull shark's jaw has an upper row of 13 teeth and a bottom row of 12 teeth.
The bull shark, Carcharhinus leucas, usually grows no longer than 10 ft. and weighs up to 500 lbs., but what it lacks in size it makes up for in aggressiveness. Experts regard it as the most pugnacious of sharks. It has, according to Robert Hueter, director of the Center of Shark Research at the Mote Marine Laboratory in Sarasota, Fla., the highest level of testosterone in any animal, including lions and elephants. Its lower spiked teeth are designed to hold prey while the upper triangular serrated teeth gouge out flesh. "The bull is an ambush type of predator, it makes this big mortal wound," says Hueter. It is fearless, taking on prey as large as it is.
A unique feature of bull sharks is their ability to live in both salt- and fresh water; they have attacked people in Lake Nicaragua in Central America and have been seen above St. Louis, Mo., in the Mississippi River. Those born in the Mississippi delta usually spend about six months in the brackish water before migrating along the coast.
The bull is the only shark that prowls regularly in water shallow enough for humans to walk in and it may be territorial. Australian shark biologist Ian Gordon has been getting into the water off Florida beaches and deliberately agitating bull sharks to observe their reaction. He says his research so far suggests that underwater geography and a sense of territory can provoke an attack. "Even if you don't know it's there, the shark will feel like it is being cornered."
Human shark victims almost always seem to be inadvertent intruders rather than targeted prey.
Some people would say bulls are the meanest sharks in the ocean. "I'd rather be in the water with a great white than a bull," says staffer Pointah Chapman. Great whites attack by sneaking up on prey and coming at it really fast, knocking it out of the water. But bulls will bite unprovoked, possibly because they are more territorial than most sharks. Licky says she encountered a bull in the water once that bit the boat -- twice. They're the bullies of the ocean and are probably responsible for many attacks on humans. Bulls can also live in fresh water, which puts them in closer proximity to humans on a regular basis.
Sharks come silently, without warning. There are three ways they strike: the hit-and-run, the bump-and-bite and the sneak attack. The hit-and-run is the most common. The shark may see the sole of a swimmer's foot, think it's a fish and take a bite before realizing this isn't its usual prey. It swims away, leaving the bleeding victim in need of stitches. The bump-and-bite is far more serious. Last year Chuck Anderson was training for a triathlon off Gulf Shores, Ala., when he was bumped by a bull shark, testing whether he was preyworthy. It decided that he was and then repeatedly attacked Anderson. He lost an arm.
Then there's the sneak attack. The shark is in the right place to find its prey, it is the right time to feed, and the target is the right size. At sunset on July 6 off Pensacola, Fla., Jessie Arbogast, 8, apparently fit the needs of a bull shark. Dusk is one of the shark's feeding periods; the boy was in the shallow water where the bull prowls; and splashing about, Jessie may have seemed to be a large fish. The shark pounced.
Suddenly reports of shark attacks began to come in from all around the U.S. On July 15 a surfer was apparently bitten on the leg a few miles from the site of Jessie's attack. The next day another surfer was attacked off San Diego. Then a lifeguard on Long Island, N.Y., was bitten by what some thought was a thresher shark. Last Wednesday a 12-ft. tiger shark chased spear fishers in Hawaii. News crews stood on the sand to interview experts, who declared over and over that sharks killed only 10 people worldwide in 2000. But don't swim at dusk or dawn; avoid murky water and steep drop-offs; shed all jewelry.
Shark attacks have been on the rise in recent years. Two-thirds were in U.S. waters.
Science is shedding light on why sharks behave the way they do. Researchers are tracking sharks via satellites and coming closer to understanding why they attack humans. The three large sharks that account for most attacks on people (the great whites, the tigers and the bull sharks) have been studied extensively. We now know that great white sharks keep their blood warmer than the surrounding water, that tiger sharks do not return to the site of an attack to prey again, and that bull sharks have the highest levels of testosterone measured in any creature, land or sea. Each has a different diet, a different behavior pattern and a different mode of attack.