SUFFOLK COUNTY, Long Island (WABC) -- Beachgoers on Long Island are urged to be on alert after multiple shark bite incidents within the last two weeks, along with additional shark sightings on Thursday.
Two people were bitten in separate incidents Wednesday, the fifth and sixth shark encounters of the summer.
A "Good Morning America" drone spotted what appeared to be a shark swimming in the water near Long Beach Thursday morning, and two swimmers spotted a 4-foot shark about 30 yards off the coast of Tobay Beach around 1:20 p.m.
Lifeguards ordered swimmers from the ocean, and all eyes remain on the water as officials employ helicopters, boats and drones to keep beachgoers safe.
During Wednesday's encounters, a paddleboarder, 41-year-old Shawn Donnelly, was bitten by a shark on his left calf around 7:30 a.m. when lifeguards were not yet on duty.
"It was definitely scary, not going to pretend like it wasn't," he said. "It hit me and knocked me off my board...I saw the fin and I saw the shark."
Then Wednesday night, a 49-year-old man reported a shark bit him in the left butt cheek off Fire Island.
Suffolk County Executive Steve Bellone said that with cleaner waters, sharks are coming closer to shore -- but lifeguards are watching.
"We have the best-trained lifeguards anywhere in the state, and we are, they are constantly on alert for any dangers out in the waterways," Bellone said. "They are constantly watching those waters, and I can tell you, they are looking for sharks."
Smith Point Beach reopened to swimming Wednesday afternoon. However, no swimming signs were up at Robert Moses Field 3 and adjacent fields Thursday morning after a shark sighting.
An off-duty lifeguard was surfing around 8 a.m. when he thought he saw a shark.
"We then dispatched the drone, and we usually have the drone available just before swimming starts at 9 o'clock, but they got there as quickly as they could, but they didn't spot the shark," NYS Parks on Long Island Regional Director George Gorman said. "But what they saw is nine stingrays right outside of the swimming area, so out of an abundance of caution, at 9 o'clock when the lifeguard went on duty, we did prohibit swimming at field 3 and the neighboring fields at 2 and 4, until those sting rays went out to sea."
The beach has since reopened, but lifeguards remain on the lookout.
While the incidents are alarming, a shark biologist with the New York Aquarium says your chances of encountering one are still extremely small.
"We are more in tune to sharks than ever before, and I think that's a bigger issue than an actual increase in incidents or an actual increase in the number of sharks," Hans Walters said.
He says there is no evidence that swimmers are more at risk this year than in years past.
Fortunately, none of the shark bites in the United States this year have been fatal.
Meanwhile, lifeguard Zach Gallo, who was bitten in the hip and chest while training at Smith Point County Beach on July 3, returned to work after being cleared by a doctor.
"I think I can pass on some knowledge to fellow lifeguards and younger guards coming up," he said. "I'm just grateful that my injuries were minor."