According to The West Australian newspaper, the attack was the fifth fatal incident involving sharks in the last 10 months.
It was a four to five metre long Great White shark, a witness told Sky News.
Some witnesses said the man was less than 50 metres from the shore when taken. But others said he was about 200 metre away on an isolated beach.
The authorities said they have placed baited lines in the area to try and catch and kill the shark.