State determines attack off Truro was by a great white shark

State officials say they have definitively determined that it was a great white shark that attacked a swimmer off a Truro beach last week.

The determination was made after interviewing the swimmer and after examining the wounds on the man’s legs, which were characteristic of a great white, said Reginald Zimmerman, a spokesman for the Executive Office of Energy and Environmental Affairs.

The ruling was made by the state’s shark expert, Greg Skomal, working in conjunction with George Burgess of the International Shark Attack File, which tracks shark bites.

“We just want to encourage swimmers and beachgoers to use common sense and be aware of their surroundings. We want people to avoid swimming at dawn or dusk, stay close to the shore, make sure they avoid areas where seals congregate, and adhere to local beach closings and swimming advisories,” Zimmerman said.

Chris Myers, a Boston native who now lives in Colorado, was attacked July 30 while swimming with his son off Ballston Beach. Officials said last week that it appeared to have been a great white shark attack. On Tuesday they made it official.

Myers, 50, said at a news conference Friday, “It felt like my leg was caught in a vise. I kicked very hard with my free leg ... and he let go.”

“I figure the shark just didn’t like the taste of me,” he said.

Experts say the last person to be attacked by a great white shark in Massachusetts waters was a teenager from Dorchester who was killed while swimming at Crescent Beach in Mattapoisett in 1936.

Concerns have been growing about the sharks for several years as more shark have been reported, especially in areas off the Cape frequented by a growing population of seals, which are a favorite food for the deadly animals.

The sharks made an enduring splash in popular culture in the movie “Jaws,” which featured a giant, voracious great white terrorizing a town in the Northeast.