But the eastern states' larger human populations make Queensland, NSW and Victoria more likely locations statistically for attacks this summer.

The curator of the Australian Shark Attack File, John West, believes there will be 12 attacks this summer - based on averages for the past 10 years, which include one death a year.

''With more people going into the water there is always an increased chance of encountering aquatic animals like sharks,'' Mr West said.

''This summer will be no exception and I would suggest that the average number of cases will probably occur this coming summer season - but hopefully not.''

It's still a little early for sharks to appear off the eastern states in great numbers, with far more expected as the fish migrate south through late spring. Many shoals of bait fish have already been seen off NSW - and one large shark has been sighted off the state's south coast.

The Westpac Life Saver Rescue Helicopter chief executive, Stephen Leahy, says there is no reason to fear a surge in attacks.

''There's nothing to indicate anything unusual,'' he said. ''Let's have a look, monitor what the water temperature's going to do - it's always towards the later part of summer we start seeing more sharks because that's when the water's nice and warm.

The Waverley mayor, Sally Betts, believes shark nets, combined with vigilant lifeguards and aerial surveillance, have helped dramatically reduce shark encounters at Bondi.

''There haven't been many confirmed shark sightings in recent years,'' she said.

Shark nets went up at 51 NSW beaches between Newcastle and Wollongong on September 1 and will remain in place until April 30.