Australian boy in critical condition after Sydney Harbour shark attack

SYDNEY: An Australian boy was in critical condition after being bitten by a shark in Sydney, authorities said on Monday (Jan 19), 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 a 6m rock with friends late on Sunday afternoon at a beach in Vaucluse, around 9km from the CBD and in the harbour, when he was attacked by the shark.

Recent heavy rain had drained into the harbour, turning the water murky, police said.

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.

He praised the boy's "gallant" young friends for going to his aid before police arrived.

Officers pulled the unconscious child onto a police boat and gave him first aid, applying two tourniquets to stem the bleeding from the boy's legs, he said.

They tried to resuscitate the boy as they sped across the harbour to a wharf where ambulance paramedics were waiting.

The child is in intensive care at Sydney Children's Hospital surrounded by family and friends, McNulty said.

There have been more than 1,280 shark incidents around Australia since 1791, of which more than 250 resulted in death, according to a database of the predators' encounters with humans.

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.

Increasingly crowded waters and rising ocean temperatures that appear to be swaying sharks' migratory patterns may be contributing to a rise in attacks despite overfishing depleting some species, scientists say.

A great white shark mauled surfer Mercury Psillakis to death at a popular northern Sydney ocean beach in September.

Two months later, a bull shark killed a woman swimming off a remote beach north of Sydney.