SHARK experts have described the three attacks in the Whitsunday's as completely out of the ordinary for the underwater predator.

Three people have been bitten by a shark at Cid Harbour in the space of seven weeks and experts have been left trying to work out what has caused the spate of attacks.

Shark attack victim travelling with doctors

"Flirting with danger" on sharks

James Cook University shark researcher Professor Colin Simpfendorfer said it was difficult to understand why the attacks have happened because there has been little research on shark behaviour in the Whitsundays.

"Obviously, it's a really unfortunate situation and given the two previous bites a few weeks back, it's bringing a lot of focus on the area," he said.

"It's really hard from a science perspective because it's an area we don't know a lot about.

"The Whitsundays, there hasn't been a lot of shark research done in that area. It's also a case of we don't know what species has been involved, or whether people have been fishing in the area."

Yesterday's attack occurred at dusk, which experts say is the most common time for sharks to be active.

Sharks and Rays Australia principal scientist Barbara Wueringer said the attacks could be occurring from boaties dumping fish carcasses and other organic waste into the harbour.

"I would say it's strange," she said.

"I would say there has been some other circumstances that has led to (the attack).

"The question is, why did this shark attempt to bite a human? This is out of the ordinary behaviour. It means the shark has overcome the fear of interacting with an animal that it doesn't know.

"I would assume that because it's a popular anchorage spot for yachts that people are discarding organic waste into the water, like fish carcasses, so I think that could be the key to what's going on there."

Ms Wueringer said she suspected yesterday's attack was more than a just "curious, investigatory bite" because of the reported injuries.

"It sounds to me that the animal came back or stuck around, so to me, that's more than an investigatory bite," she said.