Expert: Hard to pinpoint cause in shark attack spike

The spree started June 11 on Ocean Isle Beach, followed two days later by a pair of attacks on Oak Island. Last week, swimmers were bitten off Surf City, Avon and Rodanthe.

"It's hard to draw a pattern out of six instances," said Joel Fodrie, an assistant professor at the University of North Carolina at Chapel Hill's Institute of Marine Sciences in Morehead City. "Those events have ranged from near our southern border to our northern border in the state, so you're talking about very different environments, different temperatures."

UNC researchers have been studying sharks in North Carolina since 1972. Fodrie said about 50 shark attacks along the coast have been reported in the last 80 years, and more that 50 species of shark have been documented in the area.

"The vast majority are going to be 3 to 5 feet long and extremely skittish of anything a human might do," he said.

In recent years, he said, the number of larger sharks has declined, mostly due to fishing, which he said has allowed the the population of smaller sharks to increase.

Sharks move to shallow waters for any of three reasons, he said.

"They're looking for food, they're looking to avoid their own predators or a risk they perceive, and they're looking to find a mate at some point," he said.

Fodrie said that, if you're in the ocean, there's a good chance sharks are lurking in the water nearby. But despite the alarming number of attacks this summer, he said the chance of getting bitten is relatively low.

"You have to respect the power of the animals, and you have to respect the fact it can happen," he said. "I don't think you can never dip toes in the water because of sharks. There's a whole lot more dangerous things than sharks for people."