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 five to eight 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 that 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.

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“We can never guarantee anyone’s safety when they enter the water,” David Hallac, NPS’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 (R) said Thursday that state officials are looking for patterns.

“It’s an all-time record for North Carolina,” said George Burgess, director of the International Shark Attack File at the University of Florida’s Florida Museum of Natural History. He said that the bites clearly came from bigger sharks — possibly bull or tiger sharks — and that three encounters involved teenagers or a child.“This is the real deal,” he said.

Burgess 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 incidents, 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 itself 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.”

Indeed, 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.”

But the science collides with the social reality: People who like to swim in the ocean do not want to become food. A shark attack is a low probability but potentially high-consequence event. It’s a scary thought, and swimmers in America still hear the spooky music from Steven Spielberg’s movie “Jaws.”

The most recent attack was Wednesday at Ocracoke Island, where newsman Andrew Costello, 68, was pulled underwater by a seven-foot shark and bitten several times on his ribcage, hip, lower leg and hands, according to Hyde County officials. Costello managed to swim out of the water and was airlifted to a hospital in Greenville, N.C.

Last Friday, 47-year-old Patrick Thornton was able to fight off a shark that attacked him in Avon, N.C., and on Saturday, an 18-year-old boy was similarly attacked a few miles north, suffering injuries to his right calf, buttocks and hands. The events coincided with two attacks in South Carolina last week. None has been fatal.

Charles “Pete” Peterson, a joint distinguished professor at the Institute of Marine Sciences at the University of North Carolina at Chapel Hill, said he and other biologists who have long monitored the abundance of large sharks off the Carolina coast have not discerned a major shift recently.

Peterson and four colleagues published a study in 2007 showing that 11 large shark species off North Carolina’s coast “exhibited dramatic declines” between 1972 and 2003. Between 2003 and 2014, Peterson wrote in an e-mail, “there is no evidence of increasing numbers of any of the 11 species” that the team monitored.

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.”

Joel Achenbach contributed to this report.