Shark notification flags are being flown at Cedar Beach in Harpswell after two documented great white shark sightings near Bailey Island.

The flags were being displayed “out of an abundance of caution” after two of the sharks, also called white sharks, were seen within 48 hours east of Bailey Island, Harpswell Marine Resources and Harbor Management said in a social media post Wednesday.

Beachgoers are still able to access the water, but anyone who sees a shark is asked to try to take a photo and call the Cumberland County Regional Communications Center at 207-893-2810. Reporting sightings helps beach managers in Casco Bay take appropriate action, according to Harpswell Marine Resources.

Researchers say the low number of white sharks in the region means that Maine swimmers aren’t at significant risk from the sharks, which appear to be using shallow coastal waters next to popular beaches while traveling between Cape Cod and Nova Scotia. They are likely snacking on the growing seal populations in the Gulf of Maine.

Matt Davis, a marine scientist with the Maine Department of Marine Resources, said attacks or unwanted encounters with white sharks are “exceptionally rare.”

“They can potentially be dangerous because they are a large predatory fish,” he said. “When people are scared about entering the water and encountering a white shark, I like to tell them that even if they were to encounter a shark, we are not on the menu.”

On the rare occasions when an encounter does occur, it’s usually an accident because the shark has mistaken a person for a seal, Davis said.

Davis said it’s important to remember that white sharks are in their natural habitat, but Maine does not see a large concentration of white shark activity, unlike areas around Cape Cod. White sharks are typically in the waters off the Maine coast in July, August and September.

A team of New England scientists documented 107 white sharks off the coast of Maine, ranging from 7 to 16 feet in length, between 2012 and 2023, according to a study published this year in Frontiers in Marine Science.

After a white shark killed a woman swimming off Bailey Island in Harpswell in 2020 — Maine’s only fatal shark attack on record — the Maine Department of Marine Resources launched a study team and deployed acoustic sensors along the coast to track the activity of already-tagged white sharks.

The sensors show white sharks like sandy beaches. In an average year, Ogunquit will attract seven sharks in a five-day span while Higgins Beach in Scarborough attracts five. Kennebunk averages six sharks in as many days and Wells sees an average of five sharks every four days.

Nearly half of the sharks detected near beaches visited during daytime and stayed for about 15 minutes.

White sharks are not new to the Gulf of Maine. Their numbers here are likely bouncing back because of conservation measures put in place to protect white sharks, which were overfished until the 1990s, as well as seals, a favorite prey species for adult whites.

Davis said people should always be aware of their surroundings when swimming or playing in the water, regardless of the presence of white sharks. He suggests people stay close to shore, swim, surf or paddle in groups, and avoid places with seals or schooling fish. He also said people should avoid swimming at dawn and dusk when white sharks are more likely to be hunting and it’s harder for people to see.

Davis recommends that those interested in white sharks download the Atlantic White Shark Conservancy’s Sharktivity phone app, which shows recent shark sightings and real-time detections. That’s also a good way to report a white shark if you see one, he said.

Davis said people interested in white sharks can get additional information and access scientific studies through the department’s website.