By Philip Marcelo ?and Bruce Smith

CHATHAM, MASS.: From drones and smartphone apps to old-school flags and signs, a growing great white shark population along the East Coast has officials and researchers turning to responses both high- and low-tech to ensure safety for millions of beachgoers this summer.

On Cape Cod, Mass., new warning flags and signs are cropping up at some of the coastline’s most popular beaches and a local shark research nonprofit is developing a shark tracking app for the entire Eastern Seaboard.

Researchers at Duke University and the University of North Carolina, meanwhile, are testing shark-seeking drones in a scientific study that may one day give beach lifeguards a new eye in the sky.

“The days of burying our heads in the sand and saying, ‘What sharks? We don’t have sharks here’ are over,” said Gregory Skomal, a Massachusetts state biologist who has been studying Cape Cod’s surging white shark population. “It’s time to move past that and be forthright and honest with the public about the presence of these animals.”

The new measures are the latest acknowledgements of the new reality taking hold on Massachusetts’ famous coastline, where Skomal’s team identified 141 different great whites last year, up from about 80 the previous year.

The region, like others along the East Coast, has dozens of other species of sharks including blue and mako sharks, but many tend to stay farther offshore and be less aggressive than great whites, Skomal said.

The great whites are being drawn to Cape Cod’s waters because seals, their favorite food, have dramatically rebounded there, thanks to a 1972 law that made it illegal to kill them.

Researchers, beach managers and public safety officials have been convening in recent years an unofficial “shark working group” to come up with ways to educate the public. Among the ideas they developed for this summer were the warning flags, which are purple and emblazoned with the unmistakable silhouette of a great white.

By July, when Cape Cod’s waters warm and great whites begin to appear in earnest, those measures will get high-tech reinforcement.

A smartphone app being launched by the Chatham-based Atlantic Great White Conservancy will let beachgoers from Canada to Florida monitor the movements of tagged great whites and report their own possible shark sightings.