Cape Cod National Seashore Chief Ranger Leslie Reynolds warned at a news conference that the powerful predators are coming close enough to shore to be a concern for swimmers.
And Gregory Skomal, a prominent shark scientist with the state Division of Marine Fisheries, says he tagged three great whites circling a whale carcass earlier this month as his research team began its work for the season.
Great whites have been coming to the Cape in greater numbers each summer to prey on the region’s large seal colonies. Most tend to favor the Atlantic Ocean-facing beaches where seals tend to congregate, but researchers have found them off nearly every part of the Cape.
Local residents concerned about the booming shark population, meanwhile, say they'll boost their efforts to help protect swimmers this summer.
More pilots have volunteered to radio in shark sightings as they fly over the peninsula, said Heather Doyle, co-founder of Cape Cod Ocean Community, a local group that advocates for white shark surveillance and detection measures.
The Atlantic White Shark Conservancy, a Chatham-based research group, is also offering its Sharktivity smartphone app, which allows users to report and track shark sightings.