The man may have been bitten by a shark while swimming at Jones Beach.
The man was swimming in the ocean when he cut his foot.
Medics who treated the man said it could have been a shark bite. Nassau County will be increasing patrols at the beaches through the Fourth of July weekend.
After several shark encounters along Lido Beach, officials temporarily closed several beaches and started boat patrols along the shoreline.
There are very few shark attacks in the area and many experts say patrols do little more than fuel fear. More people are looking for sharks, which may be why they are being spotted more.
There is no evidence that local shark populations have increased in recent years according to a field scientist. The threat of sharks on New York beaches is overblown, he said.
At a news conference on Friday morning at Nickerson Beach, west of Jones Beach, the Nassau County executive, BruceBlakeman, was vague on details of the report.
He told reporters that he believed it was on his leg.
The man was thought to have a shark bite by the surgeons.
He said that it was a level of concern if it was caused by a shark.
The county police will be increasing patrols this summer, both by boat and by helicopter, with hourly runs along the shoreline, according to Mr.Blakeman.
He said the drones would be used to make sure there was a good picture of what was happening.
He said that bathers should always swim with friends and with a lifeguard present.
A hospital spokeswoman had no information on the patient, and a New York State Parks spokesman did not return calls.
A college student from Whitestone, Queens recoiled when she heard about the possibility of a bite.
She thought that would happen here. It isn't something that scares me, so it doesn't bother me. If there were many people in the water, I would go in.