A birds-eye view of The Great Barrier Reef. Picture: Australian Geographic

Canberra - An Australian man attacked by a shark at Cid Harbour off Australia's north-eastern coast, close to the southern end of the Great Barrier Reef, has died overnight. 

The shark attack occurred while the 33-year-old man was swimming off a private boat with friends on Monday evening in Whitsundays Island region, close to the area where two local tourists had been mauled in separate attacks within 24 hours in September.

The bite left the man with critical injuries to his left thigh, right calf and left wrist. Paramedics treated him on his boat before emergency crews airlifted him to a local hospital.

But he died in the hospital overnight, emergency staff said Tuesday. 

He is the second shark attack victim to die in Australia this year. 

Ben McCauley, the emergency helicopter crew member, described the incident as "absolutely horrific."

"He'd suffered very serious bites, significant blood loss as well as cardiac arrest," he said. 

In the September attacks, a 46-year-old woman and a 12-year-old girl were bitten by sharks one day apart in the Cid Harbour region. 

The pre-teen lost her leg in the attack, which led to a shark bait operation, in which six sharks were hooked and killed within a week.

The Whitsunday Islands region around Cid Harbour is one of the most popular holiday destinations in Australia, with more than 750,000 local and international visitors a year.

After Monday's attack, a local politician asked the Queensland state government to install permanent drum lines around Cid Harbour, like hundreds of other places along the eastern coast line.

"I think we're flirting with danger when you compare us to other communities... it's madness," Whitsunday parliamentarian Jason Costigan told ABC radio on Tuesday.