New York State Parks officials received “a couple” of reports Tuesday that several sharks were spotted about 300 yards off the shore of Jones Beach.

The sightings were off the Central Mall, the busiest part of the beach, and Field 2. Officials say swimming is prohibited but people can wade up to their waists in the water.

"It's a scary thought," says Dawn Ziminski, of Merrick. "There's more and more shark sightings hence the reason I don't go in the water past my ankles."

State park officials say the sharks are believed to be sand or thresher sharks.

"What we are seeing is a large amount of bluefish. There's literally over a thousand bluefish, schools of bluefish right along the shoreline of Jones Beach and there's bunker fish close to shore," says New York State Parks Regional Director George Gorman. "Also, we're seeing a fish that's usually down south called cobia as well as stingrays out there, in addition to the occasional shark."

There was already a stepped-up shark patrol following a possible attack on a lifeguard on Monday.

A lifeguard reported seeing a fin in the water, then noticed a 1-inch bite on his left calf.

State police responded with an all-out search, including the use of a drone, but no evidence of a shark was found.

"It's very unusual that they're this close to shore but it's the Atlantic Ocean," says Gorman.

MORE: NY State Parks on Long Island shark sightings