Parks officials closed the beach near the pier on Coney Island Tuesday out of an abundance of caution after aquarium authorities say sharks were spotted just off shore there for much of the morning.
Parks officials did not say anything about a shark, but Jon Dohlin, director of the New York Aquarium, said several had been spotted in the waters off the popular beach. NYPD aviation and harbor units were scouring the area.
Beachgoer Lucien Zayak recorded video of dorsal fins breaking the water.
"Suddenly we saw them -- I saw at least four, but it seemes there were much more than that," he told NBC 4 New York.
City parks workers approached people on the beach "and asked everyone to get out of the water because there were sharks," Zayak said.
The Coney Island beach was reopened to swimmers by mid-afternoon.
Dohlin said there are about 25 species of sharks in New York and it's "impossible" to identify the species of sharks based on images and video, but they appear to be harmless basking sharks, which pose no threat to humans. Basking sharks can grow up to more than 20 feet long. Dohlin said he believes the sharks are coming close to shore for feeding.
"Let's face it, 25 species -- every time you go swimming, you're swimming with sharks," he said. "But that goes to show how innocuous and harmless they are."
Dohlin believes the shark visit Tuesday morning is likely due to clearner waters.
"There's a lot of good momentum that's going on in conservation, and we should be thankful for that and see this as a success," he said.
Sharks were also spotted off Monmouth Beach in New Jersey Tuesday. Beach police caught a school of sharks a few yards offshore, just north of the town's beach club.
Police said there was no one swimming in the water at the time.
While sharks have been spotted singly or in pairs a few times this summer, there have been no sightings of schools of the fish like the one in Monmouth Beach.