Harpswell officials want anyone who spots a shark in town waters to immediately report it through a new hotline: 800-501-1111.

The Cumberland County Regional Communications Center will answer the calls 24/7 and collect basic information, then contact a town official who will follow up with the caller. The Communications Center also handles 911 calls and dispatches emergency agencies in Harpswell.

Photographs of sightings “are particularly helpful,” Harpswell Emergency Management Agent Art Howe said in a statement. “Please do not delay in reaching out to us if you have a sighting.”

This month’s introduction of the hotline builds on the town’s adoption of the “purple shark flag system” in June 2021, after a fatal shark attack off Bailey Island the previous summer.

Under the system, the town flies a purple flag with a white shark at local beaches after a nearshore shark sighting. The flags go up in one or more of four locations: Cedar Beach, Mackerel Cove, Mitchell Field and Stover’s Point.

“The intention is to offer the public information that is timely and as credible as possible so that people can make informed decisions about swimming or small-craft boating,” Howe said in a statement last June.

Howe said June 22 that he recently heard secondhand about a shark sighting near Potts Point on June 14. Because sharks move so quickly, he needs to know about a sighting immediately to make the flags useful. In this case, he heard a week later via social media. He couldn’t confirm the sighting, but said it sounded credible.

Reports of shark sightings are important for safety, Howe said, but also for data collection. The town shares the information it receives about sightings with the Maine Department of Marine Resources, which tracks shark activity in the state.