A shark sighting off Provincetown, Massachusetts, led officials to close Race Point Beach to swimming for about an hour on Thursday.
The shark was spotted around 3:45 p.m. about 200 yards from shore by a state police helicopter.
Video shot by a beachgoer showed a shark feeding on a seal.
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The beach was expected to reopen at 4:45 p.m.
Head of the Meadow Beach in Truro was also closed for an hour earlier Thursday after a research vessel spotted a shark near shore, the Cape Cod Times reported.
Thursday's beach closures occurred just a day after a 61-year-old man was bitten by a shark off Long Nook Beach in Truro, Massachusetts. The man suffered deep puncture wounds to his torso and leg but is expected to survive. The beach is expected to remain closed to swimming at least through Friday.
The area is a feeding ground for seals, which draw sharks, and authorities regularly caution people to avoid the water whenever seals are present.
"We hope people understand sharks are part of the ecosystem on Cape Cod," said Brian Carlstrom, superintendent of the Cape Cod National Seashore.
Despite the public's primal fear of sharks, the odds of being killed by one are roughly 1 in 3.7 million, according to the National Aquarium in Baltimore.