By Earl Filskov
There are currently 368 known species of sharks in the world. Only 20 out of the 368 are dangerous to humans. Of those 20, four are said to be responsible for 70-80 attacks on people every year. The great white shark (Carcharodon carcharias) and the orca or killer whales (Orcinus orca) are considered to be the apex predators of the sea. This is due to their machine-like hunting and killing abilities in their domain. The great white shark however, may be getting a bad rap as the number one man-eater in the sea.
According to the Global Shark Attack File, the top 10 man-eating sharks are:
• Great White Shark
• Bull Shark
• Tiger Shark
• Oceanic White Tip Shark
• Shortfin Mako Shark
• Copper Shark
• Blue Shark
• Sand Tiger Shark
• Blacktip Shark
• Hammerhead Shark
The great white shark (white shark, white pointer) does most of its hunting in the cool temperate waters of the world. The tiger shark (Galeocerdo cuvier) likes the warm tropical seas for its meal chasing. While similar in size (25 to 26 feet for large adults) these two killers look nothing alike.
The bull shark (Carcharinus leucas), while much smaller than its cousins, is quite possibly the baddest of the bad when you start looking at attacks and threat of attack on humans. Many experts now agree that the bull shark is the number one shark threat to people.
A little background
First discovered and named by French zoologist Achille Valenciennes in 1839, the bull shark is noted for its short, blunt snout, rotten disposition and a tendency to head-butt their prey before attacking. They are medium-size sharks, with thick, stout bodies and long pectoral fins. It resides in the warm coastal waters of oceans around the world. In the United States they are found on the Atlantic Coast from Massachusetts down to Florida and in the Gulf of Mexico. On the Pacific Coast they range from Southern California to the Gulf of California.
Bull sharks are rare in that not only can survive in the salt water of the oceans but can survive just as well in brackish and freshwater rivers and lakes. This is what makes them so dangerous to people.
Depending on the country they are found, the bull shark is known by several different names such as Zambezi shark, Van Rooyen’s shark (Africa); Ganges shark (India); Nicaragua shark (Central America); freshwater whaler, estuary whaler, and Swan River whaler (Australia). As you can see, these are freshwater names.
How do they do that?
Osmoregulation is the answer. Salt water and fresh water have different weights and chemical makeup, the bull shark’s body can process these different water types through their organs to keep their bodies balanced in their environment.
Their body is made up just like their ocean cousins which is why they are classified as a shark and not in the Glyphis genus of the river shark.
Bull shark facts
Bull sharks usually live to 14-16 years. They are a requiem shark; a class of warm water shark that bear live young. A full grown male can be up to 11 or 12 feet in length and weigh well over 750 pounds. Females are even larger, reaching a length of 14 or more feet. Bull sharks are loners and only get together for mating purposes. Females have up to 5 pups at a time during the spring months in shallow coastal waters. They generally hunt in the coastal waters out to depths of 100 feet or more.
They are not choosy eaters and will go after other sharks, fish, turtles, sting rays, mollusks, and even birds from time to time. They are unpredictable and unlike other sharks that will usually avoid human contact, the bull shark will bite because you are there.
The human confusion
In most shark attacks the result is usually an injury that the victim will recover from. On average, only 10 or 11 of the reported 70 to 80 shark attacks in a year result in the death of the victim. Death is usually from shock and/or bleeding to death. It is extremely rare for a person to actually be consumed by a shark. On most occasions the victim or witness (es), cannot identify the shark that was involved or if they do, they are mistaken. Excitement, fear, shock and any number of emotions and reactions contribute to mistaken identity of the culprit shark.
The bull shark is more likely than not the offending shark in most reported attacks but the blame goes elsewhere. The predominance of the bull shark in warm coastal waters where people tend to vacation and congregate makes this the more likely scenario.
One of the most famous ocean movies ever made was “Jaws,” the 1975 movie classic by Steven Spielberg that kept many people out of the water for the rest their lives. Many think the book, written by Peter Benchley, and then the movie was based on a great white shark. The reality is that the book and movie are based on a bull shark.
On July 1, 1916 in Beach Haven, New Jersey, college student Charles E. Vansant was bitten by what was believed a great white shark while swimming just off the beach in the Atlantic Ocean. He would bleed to death shortly after being pulled from the water. The attack was classified as a ‘freak occurrence’.
Five days later and 45 miles north by Essex, New Jersey, Charles Bruder was swimming with friends when he suddenly yelled “A shark bit me! Bit my legs off!” He was pulled from the water legless and dead.
Authorities put up net type barriers around all the swimming areas thinking this would protect people. They would soon Matawan is a small town approximately 11 miles inland from the ocean. Swimming was available in the Matawan Creek, a small winding fresh water body that emptied into the bay. Retired fishing captain Thomas Cattrell was walking home when he crossed the creek over a new trolley bridge. What he saw was so incredible that he ran the rest of the way into Matawan to tell everyone. Cattrell said he saw huge shark swimming up the Matawan Creek. Everyone knew about the shark attacks at the ocean but were reluctant to believe they had anything to fear. The story was written off as heat stroke.
On July 12, eleven-year old Lester Stilwell was swimming with friends in Matawan Creek. He was less than two feet from them and told them to watch him float on his back. After a couple seconds, Stanley was violently pulled under the water and blood started to fill the area. He screamed for help as he was pulled under the water several times by a very large shark. His friends jumped out of the water and ran screaming for help.
Twenty-four year old Stanley Fischer heard their calls and to help thinking Lester may be having a seizure or something. He jumped into the water and saw that Lester was still being held by the shark. While attempting to get Lester away from the shark he was attacked as well. Lester’s body would never be recovered and Stanley died a few hours later at Monmouth Hospital. As the monster shark was swimming back towards the ocean in Matawan creek it made one more strike. 12 year old Joseph Dunn was attacked as he was swimming. The shark grabbed his leg, severing it. Joseph would survive the attack.
Now, believing they had a problem, the people of Matawan took action. Fisherman Michael Slicher would catch the eight and half foot man-eater about two days after the attacks as it left the creek into Raritan Bay. The shark was mistakenly identified as a white shark, but upon cutting open the shark’s stomach approximately 15 pounds of various human were discovered. The shark was properly identified as a bull shark about 60 years later.
Bull Shark. National Wildlife Federation. http://www.nwf.org/wildlife/wildlife-library/amphibians-reptiles-and-fish/bull-shark.aspx