Shark attacks like the ones that took place along the North Carolina coast during the past week have increased during the past few decades, but experts believe that reflects human, not shark, behavior.
North Carolina has averaged about three shark attacks per year in the past decade, up from a little more than one a year on average during the 1990s, according to the International Shark Attack File at the Florida Museum of Natural History in Gainesville. There have been similar increases nationwide.
And it’s not because there are more sharks; many shark species actually are in decline because of overfishing and habitat loss. Instead, it likely is a result of more humans in oceans and better reporting.
“We’ve all been close to a shark in our lifetime if we’ve been in the water,” said George Burgess, director of the Florida Program for Shark Research and the International Shark Attack File. “Happily, sharks don’t eat human beings.”
Most shark bites result in minor cuts to feet and hands. Such bites likely are from smaller sharks mistaking the splashing of an arm or leg for the movements of a fish or other typical prey. Four such incidents were reported off the North Carolina coast last summer.
Only 11 of the 90 shark bites documented in North Carolina since 1900 were fatal, according to the Shark Research Institute. There were 156 deaths from 1,974 incidents reported nationally during that time.
The seriousness of the injuries from the recent attacks in North Carolina probably indicates a larger shark, Burgess said.
According to N.C. Sea Grant, there are more than 350 species of sharks, but only a handful of species could pose a threat to humans. The bull, tiger and white shark are considered “the Big Three” in terms of the frequency and severity of their brushes with humans. In the summer, bull and tiger sharks move into North Carolina coastal waters seeking warmer water and food.
As global temperature increases, these migrations might happen earlier in the year, said Chuck Bangley, a Ph.D. candidate at East Carolina University. Last week’s heat wave might have played a role in the attacks, Bangley said, not just because these sharks follow warm water but also because more people head to the beach in warm weather.
The last fatal shark attacks in or near North Carolina occurred over Labor Day weekend in 2001, when a 28 year-old-man was killed swimming off Avon on the Outer Banks. His 23-year-old fianceé lost her left foot in the attack. Just across the state line, a 10-year-old boy was killed off Sandbridge Beach, Va.
The bites Sunday happened just more than an hour apart on the same stretch of beach, but it’s extremely difficult to confirm if the same shark is responsible for both, Burgess said. Bite marks from both victims would have to be compared, he said.
Nationwide, Burgess said, relatively few incidents have been reported this year.
“We’re on the path to being lower than last year’s numbers,” he said. “Of course, that doesn’t mean squat to the two people that got bit.”
The most common sharks seen in North Carolina waters at this time of year are the Atlantic Sharpnose shark, smooth dogfish, blacktip shark and spinner shark, Bangley said. Injuries from blacktip and spinner sharks usually happen as they race after fish in the surf zone and “ocasionally hit a foot in the process,” said Bangley. “These bites are very rarely life-threatening.”
Humans are a greater threat to sharks than sharks are to humans. A 2013 paper in the journal Marine Policy estimated that 97 million sharks were killed in 2010, accounting for up to 7.9 percent of the total shark population – a rate greater than most species can replenish themselves. According to the International Union for the Conservation of Nature Shark Specialist Group, at least 28 percent of shark species are at risk of extinction.
How to reduce the risk of a shark bite
▪ Swim in groups and stay close to lifeguards and others who can assist in case of emergency
▪ Stay away from the water if you are wearing bright colors, wearing jewelry, or sporting an uneven tan. The color contrast may attract sharks' attention and flashing jewelry can resemble fish scales.
▪ Leave pets on the shore.
▪ Avoid areas where people are fishing.
▪ Be careful when waters are murky, or when swimming near a steep drop-off.
▪ Stay out of the water if you are bleeding.
For a complete list of recommendations and more information, check out N.C. Sea Grant's pamphlet “Shark Sense,” which is available at ncseagrant.ncsu.edu.