This is becoming another summer of the shark. The last one was in 2001, when a series of shark attacks on the East Coast combined with a period of generally slow news to whip up a spasm of shark mania.
This time, the fears are most acute in North Carolina, where there have been seven recent shark attacks -- including one Wednesday on a former Boston Herald editor-in-chief -- that caught the attention of government officials and raised the question of what might be luring the usually shy sharks so close to shore and among the swimmers they usually avoid.
There's no obvious explanation for the uptick in attacks. The sharks have ranged from 5 to 8 feet, according to victims' estimates. That suggests that different sharks -- possibly from different species -- were responsible, scientists say.
There is also no evidence that people are staying out of the water during this long holiday weekend. Tim Holloman, town manager for Oak Island, N.C., where two teenagers lost limbs in separate attacks June 14, said hotels and restaurants are full and that there are no plans to close the beach.
But the town is handing out pamphlets to raise awareness of sharks in the water. And the sheriff's office is flying a helicopter along the shore throughout the weekend. The National Park Service, which oversees beaches in the Outer Banks, has asked swimmers to be aware that there have been attacks, and two ambulances with paramedics are standing ready.
"We can never guarantee anyone's safety when they enter the water," David Hallac, the park service's superintendent of parks on the Outer Banks, said in a statement. "The only way to be sure you do not encounter sharks or other marine wildlife that may be harmful to humans is to stay out of the water."
North Carolina's seven shark attacks is an unusual number for a state that recorded 25 attacks between 2005 and 2014, according to the International Shark Attack File. North Carolina Gov. Pat McCrory said Thursday that state officials are looking for patterns.
George Burgess, director of the International Shark Attack File at the University of Florida's Florida Museum of Natural History, said it would be a mistake to start rounding up sharks. A better solution, he said, would be for beachgoers to stay on dry land or for the government to close any beach where there has been multiple shark attacks -- at least for a few days.
"It would be my recommendation that closing a beach for a day or two is a good way to stop a snowball that's rolling downhill," Burgess said.
Even with the recent attacks, researchers emphasize that sharks are a very low-level threat to humans, compared with other forms of wildlife. Bees, for example, are much more dangerous. And swimming is hazardous even without sharks around.
"Any injury or death is a tragedy, but the chances of being bitten by a shark is still a rare occurrence," said David Shiffman, a doctoral candidate at the University of Miami's R.J. Dunlap Marine Conservation Program. "Thousands of Americans drown when they're vacationing by the beach. Only one dies a year due to a shark."
The scientific consensus is that there are too few sharks these days. Many large species off the East Coast have been devastated by decades of overfishing, with populations falling by as much as 90 percent. Sharks are targeted directly -- their fins are used in soup -- and are collateral casualties from efforts to harvest tuna and swordfish.
Although stricter federal and state management has led to population gains among some faster-reproducing species, such as blacktip and sharpnose sharks, Burgess and Shiffman said it will take many decades for sharks to fully recover. According to the International Union for Conservation of Nature, 24 percent of shark species worldwide are threatened or endangered.
"Any idea that sharks have come back in large numbers in a few years is patently false," Burgess said, adding: "We are better off with healthy shark populations off our coasts than without them."
Burgess speculated that several environmental factors could have pushed sharks to congregate in the Outer Banks. It is a warm year, and the water has a higher level of salinity because of a low-level drought in the area, he said. Also, a common species of forage fish -- menhaden -- has been abundant this year and might have attracted more sharks to the area. Burgess also said some fishermen put bait in the water near piers, which could lure the predators closer to shore; two of the encounters took place within 100 yards of a pier.
"That's a formula for shark attacks," Burgess said of these conditions, taken together. "Now, does that explain seven attacks in three weeks? No, it doesn't."
Information for this article was contributed by Joel Achenbach of The Washington Post.
A Section on 07/05/2015