Nico Antic, 12, was attacked on Sunday as he and friends were jumping off rocks in Vaucluse, around 9km from Sydney’s central business district.

He was pulled from the water by friends and taken to hospital with severe injuries to both legs.

“We are heartbroken to share that our son, Nico, has passed away,” the family said in a statement.

“Nico was a happy, friendly, and sporty young boy with the most kind and generous spirit. He was always full of life and that’s how we’ll remember him,” the family said.

Dozens of beaches, including in Sydney, were closed this week after four shark attacks in two days, as heavy rains left waters murky and more likely to attract the animals.

In September, a surfer was killed by a large shark at Sydney’s Long Reef beach.

Australia averages 20 shark attacks a year, fewer than three of them fatal, according to data from conservation groups.

Those numbers are dwarfed by drownings on the country’s beaches.