A 60-year-old man was charged Friday with disorderly conduct for allegedly lying about seeing two great white sharks off a Martha Vineyard's beach, authorities said.

Edgartown police Chief Paul Condlin said Michael Lopenzo warned people to get out of the water at the Joseph Silva State Beach on Thursday. Lopenzo claimed he had seen two sharks about 22 feet long and 3,000 pounds each while he was working on a fishing boat.

Officials closed the beach, but Condlin said investigators later determined Lopenzo was lying.

When asked by detectives whose boat he was working on, Lopenzo gave the name of a nonexistent boat and owner, Condlin said.

There was no listing for Lopenzo in the town's directory. Condlin said he didn't know whether Lopenzo had an attorney.

A second beach was closed Thursday on the island — where the movie "Jaws" was filmed — after lifeguards at South Beach said they might have seen a great white shark.

The beaches were reopened Friday.