Why All The Shark Attacks? Expert Says There's Many Possibilities

In the last three weeks, there have been 7 shark attacks along the North Carolina Coast. It's an unprecedented number – the International Shark Attack File reports only 52 attacks in the last 80 years in the state, which is an 800% increase over the average.

In an interview with WFDD's Michael Burke, Dr. Fred Scharf, Professor of Fisheries Biology at the University of North Carolina's Wilmington campus, says there could be many reasons for the increase.

It is unusual that we have had so many attacks this summer already in June. There's no evidence to suggest that the increase in air temperatures, which likely would increase the coastal temperatures, would impact shark feeding behavior. This is naturally a time of year when they're in close to shore. They're feeding on abundant food sources, particularly prey fish that are close to shore that spawn in the spring and early summer and so this is a time of year when there's an abundance of food in the coastal zone and so the sharks are actively feeding. One thing certainly is that the heat wave that we had drove more people into the water being as hot as it was. At all the beaches here, instead of people sunbathing at the beach there were, I think, a lot more people in the water.

There is a lot of dredging that's going on just off the coast. Could that also be a part of the issue?

  I think the dredging just offshore for those environments can increase the turbidity which makes it much more difficult for sharks to see in the shallows and more likely they'll bump into people by accident. Most of the attacks tend to be small coastal sharks like black tips or juvenile sandbar sharks that tend to bite-and-run. They realize that you're not a prey fish and they bite once and leave.

The attacks that occurred down here on Oak island and potentially the ones off the Outer Banks where there were more severe injuries I would suspect, as others have, that those are tiger sharks or bull sharks, because both of those species tend to be more aggressive in their attacks. They're not hit and run attacks generally. They are very persistent. They're very indiscriminate feeders. They do feed on large body prey, sea turtles and large fish. When they attack humans, their initial attack is not by intent, but once the attack begins they're very persistent and of course, being large sharks, they can inflict serious injury.

For folks who are traveling to the beach this weekend and over the next couple of weeks what are some precautions they should take?

Try to swim in groups so basically there's help close by if you did have an interaction. Try to avoid areas where there is active fishing, fishing piers or people fishing from the surf. Generally people that are surf-casting are using large baits and they're trying to catch larger fish. Those baits can attract sharks. In fact, people on the beaches catch lots of sharks. No shiny jewelry that could be mistaken for for fish scales. Avoid lots of splashing and commotion. Sharks use lots of senses to locate prey. And from great distances, they're mostly using chemo-reception so they smell their prey first. They could smell blood from a potential food source from large distances, a kilometer or more. Beyond that, they're using mechanical reception so they basically feel disturbances in the water that for them could indicate a struggling prey. You know, you're in their environment, so they have the advantage.