Those heading to the beach for Father's Day weekend should know they might not be swimming alone. Great white sharks have returned to the coast of Massachusetts ahead of the summer.
According to the Atlantic White Shark Conservancy, three great whites have been detected by shark buoy receivers in the waters off the outer Cape. The toothy creatures were detected between Eastham and Wellfleet, and two were seen off Chatham.
One shark was also captured on camera by a whale watch group in Provincetown devouring a seal.
"We have always had white sharks off our coast," the conservancy's education director, Marianna Long, said. "The difference is now they're coming into more shallow water to feed on the seals."
Beachgoers at Nauset Beach in Orleans spotted plenty of seals from shore Friday.
"I just saw a 600-pound seal right here," Peter Adee, who was visiting the Cape from Los Angeles, said. "They are not kidding around. They are hungry and that's their job."
Shark researchers say the public should not get too close to the seals, either, because that is their primary food source.
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"We do need to be cautious because when we're going into the water, we're going into their natural habitat," Long said.
Scientists say swimmers should only go in the water waist deep, and should avoid swimming alone, at dawn or at dusk. The public can also download the free Sharktivity app, which lists the recent shark detections.
The conservancy just launched its research vessel for the season, but did not spot any sharks. Weather permitting, the boat should be out twice a week through the summer as they study the population of sharks swimming closer.
Typically, mid-June is when most great white sharks arrive in the New England area. Last year was a particularly active year for great whites off Cape Cod, with dozens of sightings and several beach closures due to sharks being spotted swimming close to shore. Researchers said it is not uncommon to spot sharks through November.