Australian biologists said Sunday a great white shark measuring up to 3.6 metres (12 foot) likely killed a 57-year-old surfer off Sydney this weekend, as authorities stepped up surveillance for the predators.
The experienced surfer, identified by Australian media as Mercury Psillakis, was mauled to death by a shark on Saturday off a popular beach in northern Sydney, police and rescuers say, leading to a string of beach closures.
