Nauset Light Beach in Eastham, Massachusetts was closed to swimming until 2 p.m. Monday after a shark was spotted eating a seal about 200 yards from shore.
According to the Sharktivity app, the shark sighting was reported to life guards around 1 p.m.
It is one of three great white sharks that have been spotted off Cape Cod on Monday. The others were seen off Chatham and Monomoy Island.
Thirteen sharks have been spotted in the past week.
Several beaches on Cape Cod have been shut down temporarily due to shark sightings in recent weeks.
Last year was a particularly active one for great whites off Cape Cod, with dozens of sightings and several beach closures due to sharks being spotted swimming close to shore.