A young Queensland ranger fatally mauled by a shark in front of his work mates was thrilled to have landed his dream job, his school community says.
Past pupils of Brisbane's Iona College have expressed deep sadness over the loss of Zach Robba, who suffered deadly wounds during a swim on the southern Great Barrier Reef on Monday.
The 23-year-old had spent the day with other rangers doing maintenance work at North West Island, 75km northeast of Gladstone.
Afterwards they decided to jump off their charter boat to cool off.
Zach's colleagues returned to the boat ahead of him when the shark struck.
"They would have witnessed the attack," Detective Senior Sergeant Tony Anderson told reporters on Tuesday.
"There were four people swimming off the back of a boat, cooling down after a day's work."
The ranger suffered extensive leg and arm injuries and survived an emergency flight to the Gladstone hospital but later died.
It's not clear what kind of shark was involved.
In a statement posted on social media on Tuesday, the Iona College Old Boys Association said the 2014 graduate died while undertaking research and maintenance work.
"This was Zach's dream job and he embraced all that it entailed," the association wrote.
"Every one of us has a Zach shaped hole in our heart. And each shape is unique."
Environment Minister Leeanne Enoch has offered her sympathy to the victim's family and says a report will be prepared for the coroner.
"The ranger network is like a family and we have lost a brother today," she said in a statement.
Monday's attack was the third at North West Island in just over three months.
In early January, a nine-year-old girl was attacked by a shark, suffering a bite wound to the back of her leg, and puncture wounds to her foot.
A lemon shark was suspected of that attack.
And in late December a shovelnose shark bit a man in shallow waters at North West Island.
He suffered minor injuries to his right hand and leg.
There have also been a series of other shark attacks on the Great Barrier Reef over the past 18 months.
Last October, two British backpackers were attacked while snorkelling at Hook Island in the Whitsundays. One of the men lost his foot.
In March last year, a 25-year-old man suffered serious thigh injuries when a shark attacked him at Hardy Reef, near Hamilton island, which is also in the Whitsunday Islands chain.
Those attacks followed another fatality in November 2018, when Victorian doctor Daniel Christidis, 33, was killed at Cid Harbour at Whitsunday Island.
Australian Associated Press
