Bull sharks are potential man eaters and are regarded as one of the most aggressive and unpredictable sharks. Rarely reaching a length of more than 3.4 meters (10 feet) or a weight of more than 230 kilograms (510 pounds), they eat a wide variety of things: bony fish, invertebrates, birds, mollusks, dolphins, mammals and other sharks, including young bull sharks.
Bull sharks are often found close to shore, sometimes in very shallow water. Also known as river whalers and freshwater whalers, they live mostly in salt water but periodically venture into lakes and rivers as far away as 2,000 miles from the nearest salt water. They have been observed near St. Louis on the Mississippi River and 3,000 kilometers upstream in the Amazon. In 1937 two fishermen caught an 84-pound bull shark near Altin, Illinois, 1740 miles from the Gulf Of Mexico. Bull sharks are the only big sharks that can go into fresh water and cope with great changes of salt to fresh water.
Bull sharks have the highest testosterone levels measured in any animal, including lions and elephants. They have two spineless dorsal fins, five pair of gill slits, a stubby rounded snout and large, angular pectoral fins.
Fresh water bull sharks are found in Lake Izabel in Guatemala and Lake Nicaragua. Scientists speculate the sharks entered the lakes through rivers or possible they date back to a time before the Ice Age when these lakes were part of the ocean. Sharks have also been reported in the Ganges in Pakistan and India and the Tigris and Euphrates in the Middle East.┲
Bull sharks have lower spiked teeth designed to hold prey in place and lower serrated teeth that tear flesh apart. George Burgess, director of the International Shark Attack File at the University of Florida, said their teeth are designed to incise chunks out of their prey and shear off flesh.” They usually ambush their prey and are not afraid to attack on prey as large as it is,” he said.
Bull Shark Attacks
Bull sharks are one three species of sharks along with great whites and tiger sharks involved in relatively large numbers of provoked and unprovoked attacks on humans. Between 1876 and 2001, bull sharks were involved in 69 recorded unprovoked attacks, 17 of them fatal.
Bull sharks are considered the deadliest of all sharks. The have probably killed more people than any other species because they often are found in places where people hang out. Many unreported shark attacks and attacks in which the shark species is not identified are believed to involve bull sharks. They will eat anything that gets in their way and often catch prey in murky water where they can’t see exactly what they are is killing.
Bull sharks have killed several people in rivers and brackish water estuaries in South Africa and have attacked people in Lake Nicaragua in Central America. Some of the attacks in South Africa occurred in shallow swamps were initially they were thought to have been caused by crocodiles because it was considerable impossible for sharks to live there. They may have been responsible for killing four people in a creek in New Jersey in 1916.
Bull Shark Attacks in Florida
An American woman was attacked by an 8-foot bull shark in October 1993, told Time, "It felt like a truck had slammed into me, then I felt a compacting squeeze and an actual burning in my left leg.” The shark spun her around and then left and the woman was able to make it to shore.
In August 2000, Thadeus Kubinski, who was attacked and killed by a 200-kilogram bull shark in St. Petersburg, Florida. Kuninski was taking his daily swim. He was killed after he jumped off his dock and landed near the feeding 2.5-meter shark.
In 1999, 43-year-old Michael Knowles, an avid diver says a seven-foot bull shark bit him near the Middle Keys as he tried to swim along with a pod of dolphins. Knowles, who was in the Keys for the lobster mini-season, told the U.S. Coast Guard he was cruising on a friend's 23-foot motor boat about two miles off Key Colony Beach when he spotted the dolphins. As soon as he jumped in to join the dolphins, Knowles saw a bull shark and tried to ward it off by kicking its head. At the same time he said another shark chomped his other leg, leaving five one-inch cuts just above his ankle. Doctors later sewed up the gashes. Sharks often hang around with pods of dolphins, with both species looking for fish to eat in the early evening hours. [Source: St. Peterburg Times]
Bull Shark Rips Off Boy’s Arms and Other Attacks
On July 6, 2001, a 7.4-foot, 200-pound bull shark tore off the arm of an 8-year-old boy in Pensacola Florida. The shark attacked in waist deep water and took a bite of the boy's arm and thigh during the first pass. The shark then clamped onto his arm. While people on the beach wrestled with the shark it ripped the boy’s arm off. One man then pulled the shark ashore and shot it four times in the head, pried open the mouth with baton and reached in pulled out the boy's arm.
The boy and his arm were rushed to the hospital. The arm, which was ripped off four inches from the shoulder, was reattached but the loss of blood left the boy near death and caused brain damage. The boy remained in a light coma when he was released from the hospital five weeks after the attack.
Three Shark Attacks in One Week in Florida
In June and July 2005 there were three shark attacks in a week in Florida. In June 2005, a 14-year-old girl,Jamie Daigle, died after she and friend were attacked by a bull shark while swimming in the Gulf of Mexico near Destin on the Florida Panhandle. The teenagers were swimming on boogie boards about 100 meters of shore when the shark attacked. She bled to death presumably before she reached the beach.
A man who was surfing at the time said he saw a dark shadow in the water and then found Daigle in the center of a bloody circle of water, with much of her thigh missing and the bone exposed. The girl had started swimming towards the shore. The man put her girl on his board and swam to the shore. He said the shark was about 2.5 meters long and probably a bull shark and it tried to grab Daigle’s hand. “He just followed us right on the beach,” the man aid. He said he punched the shark in the nose when it attacked him. “He was determined to finish lunch, I hate to put it that way, but that was what he was trying to do,” he said.
Two days later a 16-year-old boy fishing in waist deep water in the Gulf of Mexico, off Cape San Blas near Panama City, 80 miles southeast of Destin, was bitten so badly his leg had to be amputated. The boy was fishing with two friends. He was bitten in the right thigh, nearly severing his leg.
In the third attack, an Austrian tourist was bitten in the leg as he stood in ankle-deep water in the Gulf of Mexico near the lighthouse at Gasparilla Island beach. The tourist was airlifted to a hospital and had surgery to repair some ligaments, tendons and blood vessels.
Alabama Bull Shark Attack
In June 2000, in the Gulf of Mexico off the coast of Sluf Shores Alabama, two men training for a triathlon were attacked by a 7-foot bull shark. In the first bite of the first attack the shark bit off the first fingertips of 44-year-old Chuck Anderson. "The forth time, my right arm went into his mouth, and we went down to the bottom," Anderson said. “ The shark kept biting until the man heard the bone snap and break off,” Anderson then swam to shore with one arm. [Source: New York Times]
Confronted by a shark that had already sheared too his friend’s arm, 55-year-old Richard Watley knew he had the fight of his life. It came up under me, and I looked down and saw him staring me right in the face. I thought, 'I'm going to die,' and I decided I wasn't going to die without a fight,'' Watley said.
Anderson lost his right arm a few inches below the elbow and Watley was bitten all the way up the right side of his body. “It hit Chuck first. I didn't even know what was going on,'' Watley said. The shark chased Anderson all the way to shore, then came after Watley, who was about 80 to 100 feet out. He had seen Anderson stagger out of the water but thought he had just run into some jellyfish.
“It bit my thigh and would have taken a chunk out of me, but I hit it again,'' Watley said. I thought it might leave me alone, but it came at me again and again. I would punch him, he would retreat, and then I would swim as fast as I could for about 5 to 10 seconds, but then I would have to turn around and face him again. He chased me all the way to shore.'' It was the first unprovoked shark attack in Alabama waters in 25 years.
Shark Expert Seriously Bitten by Bull Shark in Bahamas
April 2002, a shark expert known for unusual research methods and "pushing the envelope" in his studies was badly bitten by a shark in the Bahamas. Dr Erich Ritter, chief scientist for the Global Shark Attack File, based in Princeton, New Jersey, was bitten in the calf by a 350lb bull shark during filming of a Discovery Channel program off Walker’s Cay. "It was a serious injury," said Marie Levine, executive director of the Shark Research Institute in Princeton.
Mr Ritter, 43, was bitten in murky, waist-deep water as he worked with lemon, black-tip and bull sharks, Ms Levine said. The bull shark was chasing a remora fish and bit Mr Ritter by accident. "There was food in the water about 15 yards from Erich. A bull shark closed on the remora but in the low visibility bit Erich instead."
The shark’s teeth went to the bone and Mr Ritter was rushed to a hospital in Florida, where he underwent an arterial graft. "They were really pushing the envelope," Ms Levine said. "This is one of those things that can happen when you’re working with big animals."
But Sam Gruber, a University of Miami shark expert who worked with Mr Ritter in the 1990s, said his methods were scorned and called him "an accident waiting to happen". "He has been getting more and more fearless, or some would say bold. This method is basically to titillate TV cameras. He wants to impress people that he can control these sharks and they will never bite him."
Range of bull shark (Carcharhinus leucas)
In February 2008, an Austrian tourist diving without a cage in chummed waters in the Bahamas was bitten in the leg by a bull shark. He died of blood loss the next day. It was the first death attributed to shark feeding.
Image Source: National Oceanic and Atmospheric Administration (NOAA) noaa.gov/ocean ; Wikimedia Commons
Text Sources: Mostly National Geographic articles. Also the New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Natural History magazine, Discover magazine, Times of London, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Lonely Planet Guides, Compton’s Encyclopedia and various books and other publications.
© 2009 Jeffrey Hays
Last updated March 2011