A trip to the Whitsunday Islands turned fatal for Daniel Christidis, who was tragically mauled to death by a shark at Cid Harbour on Monday evening.

The 33-year-old doctor who worked at Melbourne’s Austin Health as a urologist has been remembered for his “heart of gold”.

“We are deeply saddened by the tragic loss of Dr Daniel Christidis who was a research fellow with Austin Health,” said a spokeswoman from the hospital.

“Our thoughts are with his family during this difficult time.”

She added that staff were being offered counselling to deal with the sudden loss of their colleague.

Attacked by an unknown species of shark, the incident with Dr Christidis is the third serious attack in the area in two months. In September both Justine Barwick from Tasmania and Hannah Papps from Melbourne were bitten on separate occasions at Cid Harbour.

But according to Blake Chapman, a marine biologist, before the three shark attacks, such incidents were unheard of in the area. He says more research needs to be conducted to find out why this is now happening.

“We need to be looking at the baitfish movement, we need to be looking at the water conditions … any other factors that might be happening in that area that is obviously changing shark activity,” said Dr Chapman.

“Because two months ago this wasn’t an issue. It was pretty much unheard of in that area, so something has changed and that’s what we need to be figuring out.”

In the meantime, signs will be put up this weekend warning people to abstain from swim in the harbour under any circumstances.