LOS ANGELES: The semi-circular shark bite stretched from Maria Korcsmaros' shoulder to her pelvis, with teeth marks visible in the shredded flesh of her arm and torso.

Korcsmaros was training for a half-triathlon over the weekend off the coast of Newport Beach, California, when she "felt something hit her," said Dr Phillip Rotter of Orange County Global Medical Center, where she was treated after the attack.

Surgeons repaired the massive wound with a shape that Rotter described as "obviously a mouth."

"You could see individual marks from individual teeth," he added.

The 52-year-old Korcsmaros also suffered fractured ribs, lung lesions and damage to the muscles and skin of her upper arm and abdomen. She was expected to survive, but it was too early to know whether she will regain full use of her arm.

The bite likely came from a large great white shark, said marine biologist Chris Lowe, director of Shark Lab at California State University, Long Beach.

Though difficult to draw a definitive conclusion, he said a large single bite suggests the shark is over 10 feet long. A white shark — also known as a great white — would be the most likely candidate lurking in Southern California waters, he added.

Scientists believe the white shark population off California has been growing, Lowe said.

"This is the sort of thing we expect to see increase," Lowe said of the attack. Still, he pointed out that such attacks remain rare.

Korcsmaros was swimming in a wetsuit just outside buoys marking a protected swimming area near a boat route. Lifeguards in a boat who saw her struggling about 100 yards offshore found her gushing blood, doctors and fire officials said.

They saw the last part of the attack and knew she didn't get hit by a boat or watercraft, said Rob Williams, chief lifeguard of the Newport Beach Fire Department's Marine Operations Division.

Lifeguards pulled her from the water, and she was rushed to the emergency room, where she appeared alert and "remarkably calm," Rotter told reporters at the hospital.

The press conference got interrupted when someone in the audience apparently fainted as doctors described Korcsmaros' wounds.

Lifeguards and city officials have been unable to locate the shark that bit the mother of three but still moved to protect beachgoers. They kept thousands of people out of the water over the holiday weekend and searched miles of shoreline for the animal.

One stretch of shoreline that was closed immediately after the attack was reopened on Tuesday afternoon, but the beach where the attack took place remains closed.

Surfers, swimmers and others were allowed to return to a mile-long stretch of water from Balboa Pier to a surfing spot known as the Wedge, Newport Beach spokeswoman Tara Finnigan said.

The ocean remains off limits from Corona del Mar State Beach, where Korcsmaros was attacked, to Crystal Cove State Beach.