BIDDEFORD –– A local shark expert said swimmers don’t have to be scared out of the water despite three beaches closing over the weekend and a near-miss event with a lifeguard in Scarborough.

“I don’t necessarily want people to fear the water or necessarily fear these animals, just being aware that they are there, and you are sharing the environment with them,” said Bryan Franks, director of the School of Marine and Environmental Programs and the Girard Marine Science Center at the University of New England in Biddeford.

The Maine Department of Agriculture, Conservation and Forestry closed Mile Beach, Half Mile Beach and East Beach Sunday, in part due to “numerous shark sightings over the past three days.”

And in Scarborough, Lifeguard Greg Wilfert was dragged underwater off Scarborough Beach Saturday when what is believed to be a great white shark grabbed the rescue torpedo he was swimming with and dragged it underwater.

“I thought I got caught in a boat propeller and it pulled me under, and I realized when I was going under there was no boat,” Wilfert said in a statement. “And I knew what it was. I knew it was a great white.”

Wilfert was being pulled by the strap attached to the torpedo until he freed himself and swam safely to shore. Franks said it’s not uncommon for a shark to grab at something it doesn’t recognize.

“They see a novel stimulus in the water and they’re curious about it,” he said.

He stressed however, that shark attacks on humans are rare, saying, “It is a very miniscule percentage.”

In its statement, Black Point Resource Management, which runs the beach through a public-private partnership with the State of Maine, noted that Scarborough Beach has a team of lifeguards monitoring the ocean. They have a number of tools at their disposal, including Jet Skis, drones and even rescue dogs.

The management firm said the lifeguards have rescued 13 people this year alone.

Shark sightings, Franks said, are on the rise in the Atlantic, including Maine, but it’s not clear why. It may be as simple as newer technology allows humans to be more vigilant and spot them more easily. It could be warming water temperatures are attracting the sharks, or it could be that the populations are rising due to conservation efforts.

“That’s a really tricky one to answer,” he said.

Regardless of the reason, Franks said recent sightings are cause for caution and vigilance, but not fear.

“It’s certainly something that folks should be aware of the fact that when they do enter the ocean, especially this time of year, there are sharks present in the water, and there’s definitely precautions that should be taken,” he said.

Among those, Franks said, is observing the time of day. Sharks tend to be more active at dawn and dusk. He also said it’s a good idea to stay in clearer water whenever possible.

“Murkier water, it’s harder to see them and it’s harder for them to distinguish what you are,” he said.

Franks also said marine life in general is more active near where a river meets the ocean. That brings nutrients that attracts all manner of smaller fish, which are often prey for sharks. He said swimmers should avoid other smaller fish, particularly in large schools.

Ultimately, Franks said, people need to remember that going into the ocean is like going off into the woods – one should be prepared to encounter anything.

“A lot of it is just precaution, being aware and knowing that when you enter this environment, you’re entering that wild environment where there may be predators in the region,” he said.