Humans have the upper hand over sharks now, with millions of sharks killed each year, often just to become a pricey soup ingredient. You can read about the latest findings concerning shark finning at Discovery News.
But it's also fair to say that if a flailing naked and weaponless person goes into the ocean and encounters a great white, I'd put my bets on the shark. While your chances of being a shark attack victim are incredibly slim, each year, surfers, boogie boarders and other water enthusiasts are bitten by sharks and the injuries and deaths make news. The events are sometimes referred to as "hit-and-run attacks," since the victim may not see the shark, only the gash it left behind.
(Image: National Gallery of Art)
Now George Burgess, one of the world's foremost shark authorities and a University of Florida researcher, has come up with a way of identifying the shark species based upon the bite mark it leaves behind. The technique is analogous to analyzing human fingerprints. You study the bite marks and then compare them to the jaws and teeth of the apex ocean predators.
"Every time we investigate a shark attack one of the pieces of information that we want to have is what species was involved and what size it was," Burgess said. "Because I've been looking at shark attack victims for 30 years I can estimate what did the damage, but I have never been able to actually prove it."
With his new method, developed with the help of University of South Florida researchers, he can tell if the beast biter was a 14-foot tiger shark or a 9-foot bull shark. The findings were published in the November Marine Biology.
"There's a psychological need for many shark attack victims to know what bit them," Burgess said. "One of the few things shark attack victims have going for them after a bite is bragging rights and the bragging rights include knowing what did the damage."
The new info will also help to prevent hype about the size of attacking sharks. Like fishing stories, the enormity of the animal tends to increase with each tale telling.
Burgess said the identification methods "will give an actual basis for determining what species was involved and the size, not that that's going to affect the size claimed by the victim in a bar."
He and his team experimented with some 24 sets of dried shark jaws located in museums and private collections before coming up with their usable shark ID technique. It works on shark bites found on anyone and anything: humans, fish, other mammals, surfboards, underground cable lines, you name it.
Aside from helping to put a stop to exaggerated shark bite stories, the new research could allow scientists to better understand the behavioral reasons behind specific shark attacks, along with figuring out the prey habits of these elasmobranchs.
Dayv Lowry, a biologist with the Washington Department of Fish and Wildlife, worked on the research with Burgess while he was a graduate student at the University of South Florida.
"Often someone will send us a picture of a dolphin carcass or a sea turtle and want to know what kind of shark bit it," Lowry said. "Knowing that it's a large tiger shark, for example, would help us figure out what large tiger sharks like to eat and how they attack their prey. If an animal or person has been bitten on the rear end, then we know these sharks are likely to sneak up to get their prey instead of facing the victims."
In future, the information could influence the mesh size of offshore nets used to protect swimmers in areas like South Africa, where sharks and humans have mixed with bloody consequences. It also has the potential of saving money paid out for damages to intercontinental telephone wires and other underwater electronic equipment, all of which sharks are known to chomp into, probably wondering what the heck these weird objects are doing in their domain.
To read more about sharks and Burgess' work, check out his first rate shark pages at the Florida Museum of Natural History website.