A man was bitten by a shark at Jones Beach State Park's Field six around 12 p.m. on July 3, officials said.
State Parks Regional Director George Gorman said, "Bandaged him up and he was transported to Nassau University Medical Center. We immediately brought everybody in from the water."
He was taken to the hospital and is expected to make a full recovery.
Eyewitnesses said the victim emerged from the water bleeding from his foot and fell to the ground once on land; lifeguards tended to him before emergency services transported him with non-life-threatening injuries.
The state parks office said, "After no sharks or other dangerous marine life were observed for an hour, swimming was reauthorized but restricted to wading up to swimmers' waists," and added that the incident remains under investigation.
Officials said about 100,000 people were at the Nassau County beach at the time of the incident.
A shark was spotted around 10:30 a.m. at Rockaway Beach in Queens earlier the same day, prompting officials to close that beach for about an hour.
On July 2, officials spotted a shark estimated to be between 8 and 9 feet long at Point Lookout in Hempstead in Nassau County, and surrounding beaches were closed for about an hour.
Town officials said lifeguards red-flagged Point Lookout and nearby beaches after spotting a nine-foot shark about 45 yards off Point Lookout, and the town deployed a Shark Patrol to inspect local waters using a drone and a jet ski; officials said the shark was seen from the main lifeguard chair, the most crowded area of the beach.
Notify NYC, an X account operated by the New York City Emergency Management, shared that there had been "multiple shark sightings" on July 2 at Rockaway Beach and told beachgoers to "expect intermittent beach closures."
Lana Zak said, "Many hit the beach in hopes of cooling off on this holiday Friday, but more bodies near the water mean a greater risk of shark attacks."
The Jones Beach Lifeguard Corps did not immediately respond to a request for comment.