SYDNEY, Jan 19 (Reuters) - An Australian boy was in critical condition after being bitten by a shark in Sydney, authorities said on Monday, after heavy rain created ideal conditions for sharks to enter the city's harbour.
The boy, believed to be 12 or 13, had been jumping off rocks with friends late on Sunday afternoon at a beach in Vaucluse, around 9 km (5.5 miles) from the CBD and in the harbour, when he was attacked by the shark.
He was pulled from the water by friends and emergency services with severe injuries to both legs, and remains in a critical condition.
"He's in for the fight of his life now, and the actions of emergency services yesterday gave him that chance," New South Wales Police Superintendent Joseph McNulty told reporters on Monday.
The attack follows days of heavy rain that filled the harbour with fresh water, creating ideal conditions for the bull shark suspected to be behind the attack - a species that thrives in brackish water.
"We believe the combination of the brackish water, the fresh water, the actions of the splashing may have made that perfect storm environment for that shark attack yesterday," McNulty said.
Australia sees around 20 shark attacks per year with just under three of those being fatalities, according to data from conservation groups - numbers that are dwarfed by drownings and other accidents on the country's beaches.
(Reporting by Alasdair Pal in Sydney; Editing by Raju Gopalakrishnan)
