Seven years ago, this was just another sleepy seaside town. After weathering long winters, vacationers from throughout New England packed its beaches every summer.

But over Labor Day weekend of 2009, some visitors arrived that would change this Cape Cod town forever: Great white sharks.

That weekend, marine biologist Greg Skomal tagged five great whites off the coast of Chatham, marking the return of the legendary predators after perhaps hundreds of years of exile from Cape Cod. They’ve been back every year since, congregating around the long, sandy shoals south of town and feasting on grey seals.

“We became shark city,” says Lisa Franz, executive director of the Chatham Chamber of Commerce. “The first year that [Skomal] was tagging the sharks, we had traffic jams. You go down to Lighthouse Beach, there’d be buses [of tourists]. Every time there was a sighting or a tagging there would be news trucks. It was just crazy.” (Read the special magazine feature on why great white sharks remain a mystery.)

Technically, great whites were nothing new in Cape Cod. Every salty old fisherman in the region has a story of seeing one or maybe even pulling one onboard. Most of Steven Spielberg’s film Jaws was filmed across the sound in Martha’s Vineyard. But these sightings were rare, and scientists assumed the population of great whites off New England was small and fragmented.

Scientists aren’t sure yet how many great whites are now making Cape Cod their vacation destination. Last summer, 141 were identified. Younger sharks tend to appear first, around July, followed by the older ones, some measuring 16 feet long. All seem to linger through the fall, but their migration patterns are unknown.

Great whites congregate in only a handful of places around the world, and until recently none of these hubs was on the Eastern Seaboard. All of a sudden Chatham was an epicenter for the world’s most iconic ocean predator. Tourists came to town expecting to see sharks, some even asking when the feeding times were. And the town had to adapt.

“A lot of the businesses don’t want us to be known as the shark town. And a lot of people in town don’t want us to be the shark town. But it’s the reality, so you have to deal with it,” Franz says.

View Images A great white shark off Cape Cod may have migrated to the area in search of plentiful play. Photograph by Brian Skerry, National Geographic

Today, every souvenir shop has shark plush toys and T-shirts. One local contractor hangs a giant foam shark from the back of his flatbed truck parked on the main drag. The new regional high school has made its mascot a great white shark, and the town organizes an annual event called “Sharks in the Park,” where businesses decorate the library’s lawn with wooden sharks.

“I think it’s more exciting for visitors,” says Richard Sullivan, who works at the local watering hole, Chatham Squire, which participates in all the fun. “Of course the local movie theater shows Jaws every summer now. It’s a big hit.”

On the beach is a laminated sign that reads “Treat every week like it’s Shark Week.”

No one has taken this idea to heart more than local veterinarian Tom Burns. Once he realized the sharks were here to stay, he began going out on his boat with fake seal lures, trying to learn more about the sharks’ habits by drawing them to the surface. He tracks them with the help of spotter planes and has refined his neoprene and wood lures to the point where he’s better than most marine biologists at attracting sharks.

“I’m really proud of the Cape,” he says. “I think the Cape has been about as receptive as they could be to these animals. This could be a beautiful coexistence.”

View Images An aerial view reveals a shark and seals along Cape Cod, a popular summer destination. Photograph by Brian Skerry, National Geographic

Inevitable Attacks

Perhaps. But the story isn’t over yet. At some point, experts predict that there will be an attack in these waters.

“It’s not if, it’s when, in terms of somebody being fatally attacked. We’ve got seals being eaten within 100 meter of surfers. Think about that,” Skomal says. “Cape Cod is coexisting right now but we haven’t had the attack; we haven’t had that fatal attack.”

When it happens, Skomal predicts that the victim most likely will be a surfer near a seal colony. Several popular surf spots are located near where seals like to haul out. Some stand-up paddlers in the area think it’s safer to paddle near seal colonies because they think the seals will warn them when danger is near. (They won’t. In fact, experts say paddling near a seal colony is the most dangerous place to go with great whites in the area.)

Most great whites prefer deep waters in order to stay out of sight of potential prey. But off Cape Cod, water is shallow, forcing them into the same waters where people like to swim. Skomal has tracked several great whites to within a mile or so of beaches packed with swimmers and sunbathers just north of Chatham.

This balance between curiosity and caution defines every community living near great white congregations. Southern California has seen an uptick in the number attacks over the past few years but scientists say that since 1950, an individual swimmer’s risk of an attack in California has dropped 91 percent.

Southern and Western Australia is by far the leader in attacks with 16 of the country’s 22 shark attacks in 2015 were from great whites. Australia has seen a steep increase in unprovoked attacks (from an average of 6.5 in the 90s to 13 per year over the last 10 years), likely due to the large number of people in the water.

View Images A great white attacks a seal decoy off Chatham. The shark is estimated to be 16 to 18 feet long. Photograph by Brian Skerry, National Geographic

Although the chances of being killed by a shark at the beach are lower than getting killed by a collapsing sand dune – and indeed sharks have far more to fear from us than we from them –Cape Cod community leaders now must worry about it every summer.

In 2012, two girls kayaking in nearby Plymouth were attacked by a great white, which ruined their boats but did not injure them. Harbormaster Chad Hunter was the first on the scene and rescued the girls. Afterwards, his mind spun with the gravity of the situation and with all the rescue scenarios he might soon have to face. The father of two says he is fascinated by sharks but he also loses sleep over them.

“It’s terrifyingly interesting. I guess that’s a good way to say it,” he says as he pilots a boat toward listening devices the town maintains to track tagged great whites. He stops off in the neighboring town of Duxbury, famed for its long beaches and sailing. Just days after a device went into the water, it pinged with a confirmed great white.

View Images A great white patrols cool New England waters. Photograph by Brian Skerry, National Geographic

Officials in Chatham, as in Plymouth and Duxbury, can plan how best to respond to an attack but they can do little to prevent one. Lifeguards will clear swimmers from the water as soon as a shark is spotted.

It’s a tenuous truce. In other places where great whites congregate, notably Western Australia, some frightened citizens are now calling for great white shark populations to be culled. Here, in this famous resort area–with its windsurfers, paddlers, and swimmers–only time will tell if the most feared species can cohabitate with other summer visitors.

Watch: A Nat Geo photographer shares how he got epic shots of sharks.