Why You Shouldn't Be Worried About Shark Attacks
Last week, a juvenile great white shark did bite a long-distance swimmer off the coast of southern California. But the victim was released from the hospital the next day, and its believed the attack only occurred because the shark was agitated from fighting to escape a nearby fisherman's hook.
The fact is simple: shark bites and especially shark bite fatalities in America and around the world are ridiculously rare, according to statistics from the Florida Museum of Natural History's International Shark Attack File.
Take the most feared shark of all, the great white: From 1916-2011, great whites attacked Americans 106 times when unprovoked, and only 13 of those attacks proved fatal.
When including data for all sharks, there were only 1,055 unprovoked attacks in America with the exception of Hawaii from 1837-2013, comprising just 36 fatal attacks. Even in Hawaii, where residents and tourists flock to the ocean, there have been only 129 unprovoked attacks from 1828-2013, nine of which were fatal. Global statistics are similarly low. Annually, just 70 to 100 shark attacks are reported around the globe, causing just 5 to 15 deaths.
Although the number of shark attacks has risen each recent decade, that's just because there are more people in the world, according to the Florida Museum of Natural History.
The rarity of shark bites is not because sharks are scarce - recent studies found that great white sharks are becoming more abundant off California and the east coast - but rather because they simply don't want to eat humans. "If you are at the beach there's probably a shark not far from you, and they know you're there," said David Shiffman, a marine biologist studying sharks at the University of Miami. "If sharks wanted to hurt us there would be a lot more people that are hurt by sharks than there are."
Why sharks attack
The Florida Museum of Natural History identifies three types of shark attacks. So-called hit and run attacks are the most common and involve a single bite against surfers and swimmers because the shark mistakes a human for its normal prey.
Those are primarily considered cases of mistaken identity. "We suspect that, upon biting, the shark quickly realizes that the human is a foreign object, or that it is too large, and immediately releases the victim and does not return," the Florida Museum of Natural History states on its International Shark Attack File website.
Surfers far from shore may suffer rare bites because they resemble seals from below, a normal prey for sharks, Shiffman said. But that's likely to result in a single bite rather than a prolonged attack. "There are no sharks that would prefer to eat a human, given other options," he said. "We're just not on their menu."
That's because land-based humans are not part of sharks' ecosystems. "It's like going to a foreign restaurant where you have never had the foreign cuisine and you're reticent to try something new because it's not what you're used to," said George Burgess, director of the Florida Program for Shark Research. "The same thing goes for sharks."
Nevertheless, the other two types of shark attacks are intentional. "Bump and bite" encounters involve a shark circling and often bumping a human before the attack, possibly to assess the size and strength of its prey. And in "sneak" attacks, the shark will strike without any warning. "We believe these types of attacks are the result of feeding or antagonistic behaviors rather than being cases of mistaken identity," states the Florida Museum of Natural History.
The largest species like great white, bull, and tiger sharks are the most common perpetrators of those rare attacks, whereas smaller species are more likely to ignore humans because they consider them too big for their appetites, Burgess said.
Those attacks usually target divers and swimmers in deeper waters or victims of ship and plane disasters at sea, such as the sinking of the USS Indianapolis in World War II. They are more likely to involve multiple bites and injuries that result in death.
The exact reasons for "bump and bite" and "sneak" attacks aren't entirely known. "It happens so rarely that we have very little information about it, but the fact that it happens so rarely does mean that it's not something you really need to worry about," Shiffman said.
However, the three types of attacks don't apply to what some call "rogue" sharks, who for unknown reasons behave differently than all other members of their species.
That phenomenon explains extremely rare cases where sharks repeatedly attack people on populous shores, similar to the fictional movie "Jaws." Real-life examples may include deadly attacks of several people along the New Jersey shoreline in July 1916 and near an Egyptian beach resort in December 2010. "It's not the norm. It's highly unusual," said Burgess, who compared rogue sharks to a "human that loses it and becomes a serial killer," possibly due to some type of ailment.
Persistent fears
If sharks almost never want to eat humans, and rarely bite them, then why do they have a reputation as vicious, man-eating predators? Burgess offered this opinion: people can control nearly all of their natural environment, with infrastructure like dams and roads and weapons to subdue land-based predators. "But one-on-one at sea, sharks still win, so it's one of the few natural phenomena that we don't personally control in a one-on-one situation," he said. "I think, personally, that puts a little fear of God into us."
But if a shark has the upper hand among swimmers and surfers, it's no match for fishermen. "Each year sharks kill about five humans worldwide. We're killing between 30 and 40 million sharks per year worldwide in fisheries, so it's pretty easy to see the guy doing the attacking in that relationship," Burgess said.
"The number one myth is that all sharks are out to get us, and that's simply not true," Burgess added. "There are more than 4,000 species of sharks worldwide and only a couple dozen probably are involved in shark bites historically. So most sharks have no interest whatsoever in biting a human, historically."