OCEARCH biologist: Shark attacks likely different sharks

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Last Thursday’s reported shark bite off the coast of Ocean Isle Beach was likely a case of mistaken identity, according to Dr. Larry Cahoon, a biological oceanographer at UNCW.

Sunday’s two attacks at Oak Island, however, were likely the work of a much more aggressive shark. While there’s no way to confirm the species of sharks responsible for the attacks, Cahoon said the attacks, themselves, shed some light on the sharks involved.

In the Ocean Isle Beach attack, a 13-year-old girl suffered several lacerations that have been attributed to shark.

“I think the boogie board attack was a mistaken identity attack,” Cahoon said. “[A boogie board] looks a lot like a skate or a ray and they eat those. The shark bit the little girl once, but the board twice. It wasn’t interested in her; it was interest in the boogie board. That sort of of thing is probably not terribly uncommon.”

On Sunday, a 12-year-old girl and a 16-year-old boy were attacked in waist-deep water about 20 yards offshore of Oak Island. The shark-bite victims are both in stable conditions, but both lost an arm in the attack.

“The more recent attacks are a different matter,” Cahoon said in reference to Sunday’s attacks.

“The shark or sharks in that case definitely weren’t after a boogie board,” he said. “What that suggests to me is one of the more aggressive ones, probably a bull shark. Bull sharks are common in these waters. They have a reputation of being dangerous. That’s the most likely one you’re going to see. Other moderately dangerous sharks–tigers and hammerheads–generally don’t come too close to shore.”

Dr. Jim Gelsleichter is a marine biologist with the University of North Florida, who works with the nonprofit shark research organization, OCEARCH. He, too, thought a bull shark was a likely culprit in the attacks–though not necessarily the same bull shark in both attacks Sunday.

Gelsleichter said there are about 10 species of sharks that frequent the North Carolina coast “with some regularity.”

“Most of those are seasonal visitors moving from more southerly locales,” he said. “There’s a couple species that become seasonably abundant–bull sharks being one of them. There are a handful that could be large enough…with a big bite like that it could be a very sizable black tip or spinner, a bull or a tiger. I lean toward bull, as well, but it’s really anybody’s guess. Generally speaking, the tigers don’t really move that close to shore.”

The unseasonably warm temperatures North Carolina has recently experienced could affect the migratory patterns of some sharks.

“Some of the species that would normally show up in–let’s say July–have started to show up in June because of the heat wave. There are more sharks in the water,” Gelsleichter said.

Gelsleichter said it’s unlikely the same shark or sharks responsible for Sunday’s attacks would attack again. Rather, he said, it’s more of a numbers game–more sharks are in the water off the coast and more people are in the water because of the heat.

“The sharks feed on fish. Often we look at these sorts of wounds as mistaken identity,” he said. “A large shark, even in the case of mistaken identity, can do quite a bit of damage. It’s very rare to have successive attacks in a given day. It’s only reported about twice in the past 40 years. Chances that it was the same animal is very unlikely.”

Simply put, Gelsleichter and Cahoon said: sharks are all around us in the ocean.

“The common misconception is that they see you,” Cahoon said. “Their visibility is pretty bad. The hear us. They have a noise-sensing system called a lateral line. Swimming motions make sounds and they hear us moving in the water. They are aware of our presence long before we can see them. They know we’re in the water. The vast majority of them leave us alone. [Sunday’s] attacks, that is much more unusual for us. Most attacks in North Carolina waters are mistaken identity. This has the ring of a much more aggressive animal.”

Gelsleichter suggests avoid sharks’ common feeding times–dawn and dusk.

“A lot of sharks are a little more active when the sun’s coming down,” Cahoon said, but added the timing of Sunday’s attack was too small a data set from which to draw any inferences.

Cahoon suggests avoiding swimming in areas where people are fishing.

“The sounds made by a struggling fish are extremely attractive to sharks,” he said. “I’d be rather cautious about swimming in that area. They love going after injured fish and once they’re excited, they get the idea that food is in the area. Then, you have a higher risk. I would be very cautious about swimming in areas where people are hauling in fish. ”

Caroline Curran is the managing editor of Port City Daily. Reach her at (910) 772-6336 or caroline.c@portcitydaily.com. On Twitter: @cgcurran